History.

The term was first used in 1894 by David L. Green in an article in the Quarterly Journal of Economics entitled "Pain Cost and Opportunity-Cost. The idea had been anticipated by previous writers including Benjamin Franklin and Frédéric Bastiat. Franklin coined the phrase "Time is Money", and spelled out the associated opportunity cost reasoning in his “Advice to a Young Tradesman” (1748): “Remember that Time is Money. He that can earn Ten Shillings a Day by his Labour, and goes abroad, or sits idle one half of that Day, tho’ he spends but Sixpence during his Diversion or Idleness, ought not to reckon That the only Expence; he has really spent or rather thrown away Five Shillings besides.”  Bastiat's 1848 essay "What Is Seen and What Is Not Seen" used opportunity cost reasoning in his critique of the broken window fallacy, and of what he saw as spurious arguments for public expenditure.

Opportunity costs in production.

Explicit costs.

Explicit costs are opportunity costs that involve direct monetary payment by producers. The explicit opportunity cost of the factors of production not already owned by a producer is the price that the producer has to pay for them. For instance, if a firm spends $100 on electrical power consumed, its explicit opportunity cost is $100. This cash expenditure represents a lost opportunity to purchase something else with the $100.

Implicit costs.

Implicit costs (also called implied, imputed or notional costs) are the opportunity costs that are not reflected in cash outflow but are implied by the choice of the firm not to allocate its existing (owned) resources, or factors of production, to the best alternative use. For example: a manufacturer has previously purchased 1000 tons of steel and the machinery to produce a widget. The implicit part of the opportunity cost of producing the widget is the revenue lost by not selling the steel and not renting out the machinery instead of using it for production.  One example of opportunity cost is in the evaluation of "foreign" (to the US) buyers and their allocation of cash assets in real estate or other types of investment vehicles. During the downturn in circa June or July 2015 of the Chinese stock market, more and more Chinese investors from Hong Kong and Taiwan turned to the United States as an alternative vessel for their investment dollars; the opportunity cost of leaving their money in the Chinese stock market or Chinese real estate market is the yield available in the US real estate market.

Evaluation.

Opportunity cost is not the "sum" of the available alternatives when those alternatives are, in turn, mutually exclusive to each other. It is the highest value option forgone. The opportunity cost of a city's decision to build the hospital on its vacant land is the loss of net income from using the land for a sporting center, or the loss of net income from using the land for a parking lot, or the money the city could have made by selling the land, whichever is greatest. Use for any one of those purposes precludes all the others.  If someone loses the opportunity to earn money, that is part of the opportunity cost. If someone chooses to spend money, that money could be used to purchase other goods and services so the spent money is part of the opportunity cost as well. Add the value of the next best alternative and you have the total opportunity cost. If you miss work to go to a concert, your opportunity cost is the money you would have earned if you had gone to work plus the cost of the concert.

When an option is chosen from alternatives, the opportunity cost is the "cost" incurred by "not" enjoying the benefit associated with the best alternative choice. The "New Oxford American Dictionary" defines it as "the loss of potential gain from other alternatives when one alternative is chosen." In simple terms, opportunity cost is the benefit not received as a result of not selecting the next best option. Opportunity cost is a key concept in economics, and has been described as expressing "the basic relationship between scarcity and choice". The opportunity cost of a product or service is the revenue that could be earned by its alternative use. In other words, opportunity cost is the cost of the next best alternative of a product or service. The meaning of the concept of opportunity cost can be explained with the help of following examples:

机会成本(Opportunity Cost, OC)是指决策过程中面临多项选择,当中被放弃而价值最高的选择(Highest-valued Option Forgone),又称为「替代性成本(Alternative Cost)」,就是俗语的「世界上没有白吃的午餐」、鱼与熊掌不可兼得。


Human history.

Paleo-Indians and Native Americans.

Paleo-Indian presence in what is now Grand Teton National Park dates back more than 11,000 years. Jackson Hole valley climate at that time was colder and more alpine than the semi-arid climate found today, and the first humans were migratory hunter-gatherers spending summer months in Jackson Hole and wintering in the valleys west of the Teton Range. Along the shores of Jackson Lake, fire pits, tools and what are thought to have been fishing weights have been discovered. One of the tools found is of a type associated with the Clovis culture, and tools from this cultural period date back at least 11,500 years. Some of the tools are made of obsidian which chemical analysis indicates came from sources near present-day Teton Pass, south of Grand Teton National Park. Though obsidian was also available north of Jackson Hole, virtually all the obsidian spear points found are from a source to the south, indicating that the main seasonal migratory route for the Paleo-Indian was from

Fur trade exploration.

The Lewis and Clark Expedition (1804–1806) passed well north of the Grand Teton region. During their return trip from the Pacific Ocean, expedition member John Colter was given an early discharge so he could join two fur trappers who were heading west in search of beaver pelts. Colter was later hired by Manuel Lisa to lead fur trappers and to explore the region around the Yellowstone River. During the winter of 1807/08 Colter passed through Jackson Hole and was the first Caucasian to see the Teton Range. Lewis and Clark expedition co-leader William Clark produced a

Organized exploration and settlement.

The first U.S. Government sponsored expedition to enter Jackson Hole was the 1859–60 Raynolds Expedition. Led by U.S. Army Captain William F. Raynolds and guided by mountain man Jim Bridger, it included naturalist F. V. Hayden, who later led other expeditions to the region. The expedition had been charged with exploring the Yellowstone region, but encountered difficulties crossing mountain passes due to snow. Bridger ended up guiding the expedition south over Union Pass then following the Gros Ventre River drainage to the Snake River and leaving the region over Teton Pass. Organized exploration of the region was halted during the American Civil War but resumed when F. V. Hayden led the well-funded Hayden Geological Survey of 1871. In 1872, Hayden oversaw explorations in Yellowstone, while a branch of his expedition known as the Snake River Division was led by James Stevenson and explored the Teton region. Along with Stevenson was photographer William Henry Jackson who took the first photographs of the Teton

Establishment of the park.

To the north of Jackson Hole, Yellowstone National Park had been established in 1872, and by the close of the 19th century, conservationists wanted to expand the boundaries of that park to include at least the Teton Range. By 1907, in an effort to regulate water flow for irrigation purposes, the U.S. Bureau of Reclamation had constructed a log crib dam at the Snake River outlet of Jackson Lake. This dam failed in 1910 and a new concrete Jackson Lake Dam replaced it by 1911. The dam was further enlarged in 1916, raising lake waters as

History of mountaineering.

During the last 25 years of the 19th century, the mountains of the Teton Range became a focal point for explorers wanting to claim first ascents of the peaks. However, white explorers may not have been the first to climb many of the peaks and the earliest first ascent of even the formidable Grand Teton itself might have been achieved long before written history documented it. Native American relics remain including "The Enclosure", an obviously man-made structure that is located about below the summit

Park management.

Grand Teton National Park is one of the ten most visited national parks in the U.S., with an annual average of 2.75 million visitors in the period from 2007 to 2016, with 3.27 million visiting in 2016. The National Park Service is a federal agency of the United States Department of the Interior and manages both Grand Teton National Park and the John D. Rockefeller, Jr. Memorial Parkway. Grand Teton National Park has an average of 100 permanent and 180 seasonal employees. The park also manages 27 concession contracts that provide services such as lodging, restaurants, mountaineering guides, dude ranching, fishing and a boat shuttle on Jenny Lake. The National Park Service works closely with other federal agencies such as the U.S. Forest Service, the U.S. Fish and Wildlife Service, the Bureau of Reclamation, and also, in consequence of Jackson Hole Airport's presence in the park, the Federal Aviation Administration. Initial construction of the airstrip north of the town of Jackson was completed in the 1930s. When Jackson Hole National Monument was designated, the airport was inside it. After the monument

Geography.

Grand Teton National Park is located in the northwestern region of the U.S. state of Wyoming. To the north the park is bordered by the John D. Rockefeller, Jr. Memorial Parkway, which is administered by Grand Teton National Park. The scenic highway with the same name passes from the southern boundary of Grand Teton National Park to West Thumb in Yellowstone National Park. Grand Teton National Park covers approximately, while the John D. Rockefeller, Jr. Memorial Parkway includes. Most of the Jackson Hole valley and virtually all the major mountain peaks of the Teton Range are within the park. The Jedediah Smith Wilderness of Caribou-Targhee National Forest lies along the western boundary and includes the western slopes of the Teton Range. To the northeast and east lie the Teton Wilderness and Gros Ventre Wilderness of Bridger-Teton National Forest. The National Elk Refuge is to the southeast, and migrating herds of elk winter there. Privately owned land borders the park to the south and southwest. Grand Teton National Park, along with Yellowstone National Park, surrounding National Forests and related protected areas constitute the () Greater Yellowstone Ecosystem. The Greater Yellowstone Ecosystem spans across portions of three states and is one of the largest intact mid-latitude ecosystems remaining on Earth. By road, Grand Teton National Park is from Salt Lake City, Utah and from Denver, Colorado.

Teton Range.

The youngest mountain range in the Rocky Mountains, the Teton Range began forming between 6 and 9 million years ago. It runs roughly north to south and rises from the floor of Jackson Hole without any foothills along a by 7- to 9-mile-wide (11 to 14 km) active fault-block mountain front. The range tilts westward, rising abruptly above Jackson Hole valley which lies to the east but more gradually into Teton Valley to the west. A series of earthquakes along the Teton Fault slowly displaced the western side of the fault upward and the eastern side of the fault downward at an average of of displacement every 300–400 years. Most of the displacement of the fault occurred in the last 2 million years. While the fault has experienced up to 7.5-earthquake magnitude events since it formed, it has been relatively quiescent during historical periods, with only a

Jackson Hole.

Jackson Hole is a by 6- to 13-mile-wide (10 to 21 km) graben valley with an average elevation of, its lowest point is near the southern park boundary at. The valley sits east of the Teton Range and is vertically displaced downward, making the Teton Fault and its parallel twin on the east side of the valley normal faults with the Jackson Hole block being the hanging wall and the

Lakes and rivers.

Most of the lakes in the park were formed by glaciers and the largest of these lakes are located at the base of the Teton Range. In the northern section of the park lies Jackson Lake, the largest lake in the park at in length, wide and deep. Though Jackson Lake is natural, the Jackson Lake Dam was constructed at its outlet before the creation of the park and the lake level was raised almost consequently. East of the Jackson Lake Lodge lies Emma Matilda and Two Ocean Lakes. South of Jackson Lake, Leigh, Jenny, Bradley, Taggart and Phelps Lakes rest at the outlets of the canyons which lead into the Teton Range. Within the Teton Range, small alpine lakes in cirques are common, and there are more than 100 scattered throughout the high country. Lake Solitude, located at an elevation of, is in a cirque at the head of the North Fork

Glaciation.

The major peaks of the Teton Range were carved into their current shapes by long vanished glaciers. Commencing 250,000–150,000 years ago, the Tetons went through several periods of glaciation with some areas of Jackson Hole covered by glaciers thick. This heavy glaciation is unrelated to the uplift of the range itself and is instead part of a period of global cooling known as the Quaternary glaciation. Beginning with the Buffalo Glaciation and followed by the Bull Lake and then the Pinedale glaciation, which ended roughly 15,000 years ago, the landscape was greatly impacted by glacial activity. During the Pinedale glaciation, the landscape visible today was created as glaciers from the Yellowstone Plateau flowed south and formed

Geology.

Grand Teton National Park has some of the most ancient rocks found in any American national park. The oldest rocks dated so far are 2,680 ± 12 million years old, though even older rocks are believed to exist in the park. Formed during the Archean Eon (4 to 2.5 billion years ago), these metamorphic rocks include gneiss, schist and amphibolites. Metamorphic rocks are the most common types found in the northern and southern sections of the Teton Range. 2,545 million years ago, the metamorphic rocks were intruded by igneous granitic rocks, which are now visible in the central Tetons including Grand Teton and the nearby peaks. The light colored granites of the central Teton Range contrast with the darker metamorphic gneiss found on the flanks of Mount Moran to the north. Magma intrusions of diabase rocks 765 million years ago left dikes that can be seen on the east face of Mount Moran and Middle Teton. Granite and pegmatite intrusions also worked their way into fissures in the older gneiss. Precambrian rocks in Jackson Hole are buried deep under comparatively recent Tertiary volcanic and sedimentary deposits, as well as Pleistocene glacial deposits.  By the close of the Precambrian, the region was intermittently submerged under shallow seas, and for 500 million years various types of sedimentary rocks were formed. During the Paleozoic (542 to 251 million years ago) sandstone, shale, limestone and dolomite were deposited. Though most of these sedimentary rocks have since eroded

Ecology.

Flora.

Grand Teton National Park and the surrounding region host over 1,000 species of vascular plants. With an altitude variance of over, the park has a number of different ecological zones including alpine tundra, the Rocky Mountains subalpine zone where spruce-fir forests are dominant, and the valley floor, where a mixed conifer and deciduous forest zone occupies regions with better soils intermixed with sagebrush plains atop alluvial deposits. Additionally, wetlands near some lakes and in the valley floor adjacent to rivers and streams cover large expanses, especially along the Snake River near Oxbow Bend near

Fauna.

Sixty-one species of mammals have been recorded in Grand Teton National Park. This includes the gray wolf, which had been extirpated from the region by the early 1900s but migrated into the Grand Teton National Park from adjacent Yellowstone National Park after the species had been reintroduced there. The re-establishment of the wolves has ensured that every indigenous mammal species now exists in the park. In addition to gray wolves, another 17 species of carnivores reside within Grand Teton National Park including grizzlies and the more commonly seen American black bear. Relatively common sightings of coyote, river otter, marten and badger and occasional sightings of cougar, lynx and wolverine are reported annually. A number of rodent species exist including yellow-bellied marmot, least chipmunk, muskrat, beaver, Uinta ground squirrel, pika, snowshoe hare, porcupine, and six species of bats.  Of the larger mammals the most common are elk, which exist in the thousands. Their migration route between the National Elk Refuge and Yellowstone National

Fire ecology.

The role of wildfire is an important one for plant and animal species diversity. Many tree species have evolved to mainly germinate after a wildfire. Regions of the park that have experienced wildfire in historical times have greater species diversity after reestablishment than those regions that have not been influenced by fire. Though the Yellowstone fires of 1988 had minimal impact on Grand Teton National Park, studies conducted before and reaffirmed after that event concluded that the suppression of natural wildfires during the middle part of the 20th century

Air and water quality.

Grand Teton National Park is more than air distance from any major urban or industrial area, and localized human activities have generally had a very low environmental impact on the surrounding region. However, levels of ammonium and nitrogen have been trending slightly upwards due to deposition from rain and snow that is believed to originate from regional agricultural activities. Additionally, there has also been a slight increase in mercury and pesticides that have been detected in snow and some alpine lakes. Ozone and

Climate.

According to the Köppen climate classification system, Grand Teton National Park has a subarctic climate with Cool Summers and

Recreation.

Mountaineering.

Grand Teton National Park is a popular destination for mountain and rock climbers partly because the mountains are easily accessible by road. Trails are well marked and routes to the summits of most peaks are long established, and for the experienced and fit, most peaks can be climbed in one day. The highest maintained trails climb from the floor of Jackson Hole over to mountain passes that are sometimes called saddles or divides. From these passes, the climbs follow routes that require varying skill levels. Climbers do not need a permit but are encouraged to voluntarily register their climbing plans with the National Park Service and inform associates of their itinerary. Any climb requiring an overnight stay in the backcountry does require a permit. Climbers are essentially on their own to determine their own skill levels and are encouraged to not take unnecessary risks. The Exum Mountain Guides, which is considered one of the finest mountaineering guide services in the U.S., as well

Camping and hiking.

Grand Teton National Park has five front-country vehicular access campgrounds. The largest are the Colter Bay and Gros Ventre campgrounds, and each has 350 campsites which can accommodate large recreational vehicles. Lizard Creek and Signal Mountain campgrounds have 60 and 86 campsites respectively, while the smaller Jenny Lake campground has only 49 sites for tent use only. Additionally, full hookups for recreational vehicles are at the concessionaire managed 112 campsites at Colter Bay Village and another 100 at Flagg Ranch in the John D. Rockefeller Memorial Parkway. Though all front-country campgrounds are only open from late spring to late fall, primitive winter camping is permitted at Colter Bay near the visitor center.  All campsites accessible only on foot or by horseback are considered backcountry campsites and they are available by permit only, but camping is allowed in most of these backcountry zones year-round. The National Park Service has a combination of specific sites and zones for backcountry camping with a set carrying capacity of overnight stays per zone to protect the resources from overcrowding. Open fires are not permitted in the backcountry and all

Boating and fishing.

Grand Teton National Park allows boating on all the lakes in Jackson Hole, but motorized boats can only be used on Jackson and Jenny Lakes. While there is no maximum horsepower limit on Jackson Lake (though there is a noise restriction), Jenny Lake is restricted to 10 horsepower. Only non-motorized boats are permitted on Bearpaw, Bradley, Emma Matilda, Leigh, Phelps, String, Taggart and Two Ocean Lakes. There are four designated boat launches located on Jackson Lake and one on Jenny Lake. Additionally, sailboats, windsurfers and water skiing are only allowed on Jackson Lake and no jet skis are permitted on any of the park waterways. All boats are required to comply with various safety regulations including personal flotation devices for each passenger. Only non-motorized watercraft are permitted on the Snake River. All other waterways in

Winter activities.

Visitors are allowed to snowshoe and do cross-country skiing and are not restricted to trails. The Teton Park Road between the Taggart Lake trailhead to Signal Mountain Campground is closed to vehicular traffic during the winter and this section of the road is groomed for skiing and snowshoeing traffic. The park service offers guided snowshoe tours daily from the main headquarters located in Moose, Wyoming. Overnight camping is allowed in the winter in the backcountry with a permit and visitors should inquire about avalanche dangers.  The only location in Grand

Tourism.

Visitor centers.

The Craig Thomas Discovery and Visitor Center adjacent to the park headquarters at Moose, Wyoming, is open year-round. Opened in 2007 to replace an old, inadequate visitor center, the facility is named for the late U.S. Senator Craig Thomas and designed by acclaimed architect, Bohlin Cywinski Jackson. It was financed with a combination of federal grants and private donations. An adjoining 154-seat auditorium was opened to the public in April 2011. To the north at Colter Bay Village on Jackson Lake, the Colter Bay Visitor Center & Indian Arts Museum is open from the beginning of May to the early October. The Colter Bay Visitor Center & Indian Arts Museum has housed the David T.

Accommodations.

Contracted through the National Park Service, various concessionaire entities manage lodging facilities inside the park. The largest such facility is the Jackson Lake Lodge, which is managed by the Grand Teton Lodge Company. Located near Jackson Lake Dam, the Jackson Lake Lodge has a total of 385 rooms, meeting facilities, a retail shop and a restaurant. The Grand Teton Lodge Company also manages the Jenny Lake Lodge, which consists of cabins and a

Grand Teton National Park is an American national park in northwestern Wyoming. At approximately, the park includes the major peaks of the Teton Range as well as most of the northern sections of the valley known as Jackson Hole. Grand Teton National Park is only south of Yellowstone National Park, to which it is connected by the National Park Service-managed John D. Rockefeller, Jr. Memorial Parkway. Along with surrounding national forests, these three protected areas constitute the almost Greater Yellowstone Ecosystem, one of the world's largest intact mid-latitude temperate ecosystems.

大提顿国家公园(英语:Grand Teton National Park,或译大蒂顿国家公园)是位于美国怀俄明州西北部的一个国家公园。公园的名称来自于大提顿峰。大提顿峰标高4,199米,是提顿山脉的最高峰。大提顿国家公园于1929年2月26日成立。大提顿国家公园内拥有长度达300公里的步道。园内并有以杰克森湖(Jackson Lake)与珍妮湖(Jenny Lake)为首的众多湖泊。大提顿国家公园的大部分区域均位于洛矶山脉内,自然景观十分壮美。此外,大提顿国家公园还拥有极为丰富的生物相,包括了美洲野牛、灰熊、黑熊、驼鹿等等。大提顿国家公园距离世界第一个国家公园黄石国家公园非常近。两者同属于大黄石生物圈 (Greater Yellowstone Ecosystem)。


Internationalizing Domain Names in Applications.

Internationalizing Domain Names in Applications (IDNA) is a mechanism defined in 2003 for handling internationalized domain names containing non-ASCII characters.  Although the Domain Name System supports non-ASCII characters, applications such as e-mail and web browsers restrict the characters which can be used as domain names for purposes such as a hostname. Strictly speaking, it is the network protocols these applications use that have restrictions on the characters which can be used in domain names, not the applications that have these limitations or the DNS itself. To retain backwards compatibility with the installed base, the IETF IDNA Working Group decided that internationalized domain names should be converted to a suitable ASCII-based form that could be handled by web browsers and other user applications. IDNA specifies how this conversion between names written in non-ASCII characters and their ASCII-based representation is performed.  An IDNA-enabled application is able to convert between the internationalized and ASCII representations of a domain name. It uses the ASCII form for DNS lookups but can present the internationalized form to users who presumably prefer to read and write domain names in non-ASCII scripts such as Arabic or Hiragana. Applications that do not support IDNA will not be able to handle domain names with non-ASCII characters, but will still be able to access such domains if given the (usually rather cryptic) ASCII equivalent.  ICANN issued guidelines for the use of IDNA in June 2003, and it was already possible to register.jp domains using this system in July 2003 and.info domains in March 2004. Several other top-level domain registries started accepting registrations in 2004 and 2005. IDN Guidelines were first created in June 2003, and have been updated to respond to phishing concerns in November 2005. An ICANN working group focused on country code domain names at the top level was formed in November 2007 and promoted jointly by the country code supporting organization and the Governmental Advisory Committee. Additionally, ICANN supports the community led Universal Acceptance Steering Group, which seeks to promote the usability of IDNs and other new gTLDS in all applications, devices and systems.  Mozilla 1.4, Netscape 7.1, Opera 7.11 were among the first applications to support IDNA. A browser plugin is available for Internet Explorer 6 to provide IDN support. Internet Explorer 7.0 and Windows Vista's URL APIs provide native support for IDN.

ToASCII and ToUnicode.

The conversions between ASCII and non-ASCII forms of a domain name are accomplished by algorithms called ToASCII and ToUnicode. These algorithms are not applied to the domain name as a whole, but rather to individual labels. For example, if the domain name is www.example.com, then the labels are "www", "example", and "com". ToASCII or ToUnicode is applied to each of these three separately.  The details of these two algorithms are complex, and are specified in RFC 3490. The following gives an overview of their function.  ToASCII leaves unchanged any ASCII label, but will fail if the label is unsuitable for the Domain Name System. If given a label containing at least one non-ASCII character, ToASCII will apply the Nameprep algorithm, which converts the label to lowercase and performs other normalization, and will then translate the result to ASCII using Punycode before prepending the four-character string "xn--". This four-character string is called the ASCII Compatible Encoding ("ACE") prefix, and is used to distinguish Punycode encoded labels from ordinary ASCII labels. The ToASCII algorithm can fail in several ways; for example, the final string could exceed the 63-character limit of a DNS label. A label for which ToASCII fails cannot be used in an internationalized domain name.  The function ToUnicode reverses the action of ToASCII, stripping off the ACE prefix and applying the Punycode decode algorithm. It does not reverse the Nameprep processing, since that is merely a normalization and is by nature irreversible. Unlike ToASCII, ToUnicode always succeeds, because it simply returns the original string if decoding fails. In particular, this means that ToUnicode has no effect on a string that does not begin with the ACE prefix.

Example of IDNA encoding.

IDNA encoding may be illustrated using the example domain codice_1. (.) This domain name has two labels, "Bücher" and "example". The second label is pure ASCII, and is left unchanged. The first label is processed by Nameprep to give codice_2, and then converted to Punycode to result in codice_3. It is then prefixed with codice_4 to produce codice_5. The resulting name suitable for use in DNS records and queries is therefore "codice_6".

Arabic Script IDN Working Group (ASIWG).

While the Arab region represents 5 per cent of the world's population, it accounts for a mere 2.6 per cent of global Internet usage. Moreover, the percentage of Internet users among the population in the Arab world is a low of 11 per cent, compared to the global rate of 21.9 per cent. However, Internet usage in the region has grown by 1,426 per cent between the years 2000 and 2008, which represents a large increase, particularly compared to the average world growth rate of 305.5 per cent over the same period. It is reasonable to infer, therefore, that the usage growth could have been even more significant if DNS was available in Arabic characters. The introduction of IDNs offers many potential new opportunities and benefits for Arab Internet users by allowing them to establish domains in their native languages and alphabets, and to create a whole range of services and localized applications on top of those domains.  ASIWG Chair Ram Mohan presented the case for the development of a multilingual internet at the Internet Governance Forum in Hyderabad, India (December 3–6, 2008).

Top-level domain implementation.

In 2009, ICANN decided to implement a new class of top-level domains, assignable to countries and independent regions, similar to the rules for country code top-level domains. However, the domain names may be any desirable string of characters, symbols, or glyphs in the language-specific, non-Latin alphabet or script of the applicant's language, within certain guidelines to assure sufficient visual uniqueness.  The process of installing IDN country code domains began with a long period of testing in a set of subdomains in the test top-level domain. Eleven domains used language-native scripts or alphabets, such as δοκιμή, meaning "test" in Greek.  These efforts culminated in the creation of the first internationalized country code top-level domains (IDN ccTLDs) for production use in 2010.  In the Domain Name System, these domains use an ASCII representation consisting of the prefix "xn--" followed by the Punycode translation of the Unicode representation of the language-specific alphabet or script glyphs. For example, the Cyrillic name of Russia's IDN ccTLD is "рф". In Punycode representation, this is "p1ai", and its DNS name is "xn--p1ai".

Non-IDNA or non-ICANN registries that support non-ASCII domain names.

There are other registries that support non-ASCII domain names. The company ThaiURL.com in Thailand supports.com registrations via its own IDN encoding, ThaiURL. However, since most modern browsers only recognize IDNA/punycode IDNs, ThaiURL-encoded domains must be typed in or linked to in their encoded form, and they will be displayed thus in the address bar. This limits their usefulness; however, they are still valid and universally accessible domains.  Several registries support punycoded emoji characters as emoji domains.

ASCII spoofing concerns.

The use of Unicode in domain names makes it potentially easier to spoof web sites as the visual representation of an IDN string in a web browser may make a spoof site appear indistinguishable to the legitimate site being spoofed, depending on the font used. For example, Unicode character U+0430, Cyrillic small letter a, can look identical to Unicode character U+0061, Latin small letter a, used in English. As a concrete example, using Cyrillic letters а, е ("Ie"/“Ye", U+0435, looking essentially identical to Latin letter e), Belarusian-Ukrainian і (U+0456, essentially identical to Latin letter i), р ("Er", U+0440, essentially identical to Latin letter p), the URL wіkіреdіа.org is formed ("xn--wkd-8cdx9d7hbd.org" in encoded form), which is virtually indistinguishable from the visual representation of the legitimate wikipedia.org (possibly depending on fonts).

Top-level domains accepting IDN registration.

Many top-level domains have started to accept internationalized domain name registrations at the second or lower levels. Afilias (.INFO) offered the first gTLD IDN second level registrations in 2004 in the German language.  DotAsia, the registrar for the TLD Asia, conducted a 70-day sunrise period starting May 11, 2011 for second-level domain registrations in the Chinese, Japanese and Korean scripts.

An internationalized domain name (IDN) is an Internet domain name that contains at least one label that is displayed in software applications, in whole or in part, in a language-specific script or alphabet, such as Arabic, Chinese, Cyrillic, Devanagari, Hebrew or the Latin alphabet-based characters with diacritics or ligatures, such as French. These writing systems are encoded by computers in multibyte Unicode. Internationalized domain names are stored in the Domain Name System (DNS) as ASCII strings using Punycode transcription.

国际化域名(英语:Internationalized Domain Name,缩写:IDN)又称特殊字符域名,是指部分或完全使用特殊的文字或字母组成的互联网域名,包括法语、阿拉伯语、中文、斯拉夫语、泰米尔语、希伯来语或拉丁字母等非英文字母,这些文字经多字节万国码编译而成。在域名系统中,国际化域名使用Punycode转写并以美国信息交换标准代码字符串储存。


Biography.

Youth.

Born in 1908 and raised in Brooklyn, New York, Maslow was the oldest of seven children. His parents were first generation Jewish immigrants from Kiev, then part of the Russian Empire (now Ukraine), who fled from Czarist persecution in the early 20th century. They had decided to live in New York City and in a multiethnic, working-class neighborhood. His parents were poor and not intellectually focused, but they valued education. He had various encounters with anti-Semitic gangs who would chase and throw rocks at him. Maslow and other young people with his background were struggling to overcome such acts of racism and ethnic prejudice in the attempt to establish an idealistic world based on widespread education and economic justice. The tension outside his home was also felt within it, as he rarely got along with his mother, and eventually developed a strong revulsion towards her. He is quoted as saying, "What I had reacted to was not only her physical appearance, but also her values and world view, her stinginess, her total selfishness, her lack of love for anyone else in the world – even her own husband and children – her narcissism, her Negro prejudice, her exploitation of everyone, her assumption that anyone was wrong who disagreed with her, her lack of friends, her sloppiness and dirtiness...". He also grew up with few friends other than his cousin Will, and as a result "...[He] grew up in libraries and among books." It was here that he developed his love for reading and learning. He went to Boys High School, one of the top high schools in Brooklyn. Here, he served as the officer to many academic clubs, and became editor of the Latin Magazine. He also edited "Principia," the school's Physics paper, for a year. He developed other strengths as well:

College and university.

Maslow attended the City College of New York after high school. In 1926 he began taking legal studies classes at night in addition to his undergraduate course load. He hated it and almost immediately dropped out. In 1927 he transferred to Cornell, but he left after just one semester due to poor grades and high costs. He later graduated from City College and went to graduate school at the University of Wisconsin to study psychology. In 1928, he married his first cousin Bertha, who was still in high school at the time. The pair had met in Brooklyn years earlier. Maslow's psychology training at UW was decidedly experimental-behaviorist. At Wisconsin he pursued a line of research which included investigating primate dominance behavior and sexuality. Maslow's early experience with behaviorism would leave him with a strong positivist mindset. Upon the recommendation of Professor Hulsey Cason, Maslow wrote his master's thesis on "learning, retention, and reproduction of verbal material". Maslow regarded the research as embarrassingly trivial, but he completed his thesis the summer of 1931 and was awarded his master's degree in psychology. He was so ashamed of the thesis that he removed it from the psychology library and tore out its catalog listing. However, Professor Cason admired the research enough to urge Maslow to submit it for publication. Maslow's thesis was published as two articles in 1934.

Academic career.

He continued his research at Columbia University on similar themes. There he found another mentor in Alfred Adler, one of Sigmund Freud's early colleagues. From 1937 to 1951, Maslow was on the faculty of Brooklyn College. His family life and his experiences influenced his psychological ideas. After World War II, Maslow began to question the way psychologists had come to their conclusions, and although he did not completely disagree, he had his own ideas on how to understand the human mind. He called his new discipline humanistic psychology. Maslow was already a 33-year-old father and had two children when the United States entered World War II in 1941. He was thus ineligible for the military. However, the horrors of war inspired a vision of peace in him leading to his groundbreaking psychological studies of self-actualizing. The studies began under the supervision of two mentors, anthropologist Ruth Benedict and Gestalt psychologist Max Wertheimer, whom he admired both professionally and personally. They accomplished a lot in both realms. Being such "wonderful human beings" as well, they inspired Maslow to take notes about them and their behavior. This would be the basis of his lifelong research and thinking about mental health and human potential. He extended the subject, borrowing ideas from other psychologists and adding new ones, such as the concepts of a hierarchy of needs, metaneeds, metamotivation, self-actualizing persons, and peak experiences. Maslow was a professor at Brandeis University from 1951 to 1969. He became a resident fellow of the Laughlin Institute in California. In 1967, Maslow had a serious heart attack and knew his time was limited. He considered himself to be a psychological pioneer. He gave future psychologists a push by bringing to light different paths to ponder. He built the framework that later allowed other psychologists to conduct more comprehensive studies. Maslow believed that leadership should be non-intervening. Consistent with this approach, he rejected a nomination in 1963 to be the president of the Association for Humanistic Psychology because he felt that the organization should develop an intellectual movement without a leader.

Death.

While jogging, Maslow suffered a severe heart attack and died on June 8, 1970, at the age of 62 in Menlo Park, California.

Maslow's contributions.

Humanistic psychology.

Maslow's thinking was original. Most psychologists before him had been concerned with the abnormal and the ill. He urged people to acknowledge their basic needs before addressing higher needs and ultimately self-actualization. He wanted to know what constituted positive mental health. Humanistic psychology gave rise to several different therapies, all guided by the idea that people possess the inner resources for growth and healing and that the point of therapy is to help remove obstacles to individuals' achieving them. The most famous of these was client-centered therapy developed by Carl Rogers.  The basic principles behind humanistic psychology are simple:  Humanistic psychology theory suits people who see the positive side of humanity and believe in free will. This theory clearly contrasts with Freud's theory of biological determinism. Another significant strength is that humanistic psychology theory is compatible with other schools of thought. Maslow's Hierarchy is also applicable to other topics, such as finance, economics, or even in history or criminology. Humanist psychology, also coined "positive psychology", is criticized for its lack of empirical validation and therefore its lack of usefulness in treating specific problems. It may also fail to help or diagnose people who have severe mental disorders. Humanistic psychologists believe that every person has a strong desire to realize their full potential, to reach a level of "self-actualization". The main point of that new movement, that reached its peak in 1960s, was to emphasize the positive potential of human beings. Maslow positioned his work as a vital complement to that of Freud:  However, Maslow was highly critical of Freud, since humanistic psychologists did not recognize spirituality as a navigation for our behaviours.  To prove that humans are not blindly reacting to situations, but trying to accomplish something greater, Maslow studied mentally healthy individuals instead of people with serious psychological issues. He focused on self-actualizing people. Self-actualizing people indicate a "coherent personality syndrome" and represent optimal psychological health and functioning.  This informed his theory that a person enjoys "peak experiences", high points in life when the individual is in harmony with himself and his surroundings. In Maslow's view, self-actualized people can have many peak experiences throughout a day while others have those experiences less frequently. He believed that psychedelic drugs like LSD and Psilocybin can produce peak experiences in the right people under the right circumstances.

Peak and plateau experiences.

Beyond the routine of needs fulfillment, Maslow envisioned moments of extraordinary experience, known as Peak experiences, which are profound moments of love, understanding, happiness, or rapture, during which a person feels more whole, alive, self-sufficient and yet a part of the world, more aware of truth, justice, harmony, goodness, and so on. Self-actualizing people are more likely to have peak experiences. In other words, these "peak experiences" or states of flow are the reflections of the realization of one's human potential and represent the height of personality development.  In later writings Maslow moved to a more inclusive model that allowed for, in addition to intense peak experiences, longer-lasting periods of serene Being-cognition that he termed "plateau experiences". He borrowed this term from the Indian scientist and yoga practitioner, U. A. Asrani, with whom he corresponded.

B-values.

In studying accounts of peak experiences, Maslow identified a manner of thought he called "Being-cognition" (or "B-cognition"), which is holistic and accepting, as opposed to the evaluative "Deficiency-cognition" (or "D-cognition"), and values he called "Being-values". He listed the B-values as:

Hierarchy of needs.

Maslow described human needs as ordered in a prepotent hierarchy—a pressing need would need to be mostly satisfied before someone would give their attention to the next highest need. None of his published works included a visual representation of the hierarchy. The pyramidal diagram illustrating the Maslow needs hierarchy may have been created by a psychology textbook publisher as an illustrative device. This now iconic pyramid frequently depicts the spectrum of human needs, both physical and psychological, as accompaniment to articles describing Maslow's needs theory and may give the impression that the Hierarchy of Needs is a fixed and rigid sequence of progression. Yet, starting with the first publication of his theory in 1943, Maslow described human needs as being relatively fluid—with many needs being present in a person simultaneously.  The hierarchy of human needs model suggests that human needs will only be fulfilled one level at a time.  According to Maslow's theory, when a human being ascends the levels of the hierarchy having fulfilled the needs in the hierarchy, one may eventually achieve self-actualization. Late in life, Maslow came to conclude that self-actualization was not an automatic outcome of satisfying the other human needs  Human needs as identified by Maslow:  The first four levels are known as "Deficit needs" or "D-needs". This means that if you do not have enough of one of those four needs, you will have the feeling that you need to get it. But when you do get them, then you feel content. These needs alone are not motivating.  Maslow wrote that there are certain conditions that must be fulfilled in order for the basic needs to be satisfied. For example, freedom of speech, freedom to express oneself, and freedom to seek new information are a few of the prerequisites. Any blockages of these freedoms could prevent the satisfaction of the basic needs.  Maslow's Hierarchy is used in higher education for advising students and student retention as well as a key concept in student development. Maslow's Hierarchy has been subject to internet memes over the past few years, specifically looking at the modern integration of technology in our lives and humorously suggesting that Wi-Fi was among the most basic of human needs.

Self-actualization.

Maslow defined Self-actualization as achieving the fullest use of one's talents and interests—the need "to become everything that one is capable of becoming." As implied by its name, self-actualization is highly individualistic and reflects Maslow's premise that the self is "sovereign and inviolable" and entitled to "his or her own tastes, opinions, values, etc." Indeed, some have characterized self-actualization as "healthy narcissism."

Qualities of self-actualizing people.

He realized that all the individuals he studied had similar personality traits. All were "reality centered," able to differentiate what was fraudulent from what was genuine. They were also "problem centered," meaning that they treated life's difficulties as problems that demanded solutions. These individuals also were comfortable being alone and had healthy personal relationships. They had only a few close friends and family rather than a large number of shallow relationships.  Self-actualizing people tend to focus on problems outside themselves; have a clear sense of what is true and what is false; are spontaneous and creative; and are not bound too strictly by social conventions.  Maslow noticed that self-actualized individuals had a better insight of reality, deeply accepted themselves, others and the world, and also had faced many problems and were known to be impulsive people. These self-actualized individuals were very independent and private when it came to their environment and culture, especially their very own individual development on "potentialities and inner resources".  According to Maslow, self-actualizing people share the following qualities:  Maslow based his theory partially on his own assumptions about human potential and partially on his case studies of historical figures whom he believed to be self-actualized, including Albert Einstein and Henry David Thoreau. Consequently, Maslow argued, the way in which essential needs are fulfilled is just as important as the needs themselves. Together, these define the human experience. To the extent a person finds cooperative social fulfillment, he establishes meaningful relationships with other people and the larger world. In other words, he establishes meaningful connections to an external reality—an essential component of self-actualization. In contrast, to the extent that vital needs find selfish and competitive fulfillment, a person acquires hostile emotions and limited external relationships—his awareness remains internal and limited.

Metamotivation.

Maslow used the term metamotivation to describe self-actualized people who are driven by innate forces beyond their basic needs, so that they may explore and reach their full human potential.

Methodology.

Maslow based his study on the writings of other psychologists, Albert Einstein and people he knew who [he felt] clearly met the standard of self-actualization.  Maslow used Einstein's writings and accomplishments to exemplify the characteristics of the self-actualized person. But Ruth Benedict and Max Wertheimer were also Maslow's models of self-actualization. In this case, from a scientific perspective there are numerous problems with this particular approach. First, it could be argued that biographical analysis as a method is extremely subjective as it is based entirely on the opinion of the researcher. Personal opinion is always prone to bias, which reduces the validity of any data obtained. Therefore, Maslow's operational definition of Self-actualization must not be blindly accepted as scientific fact.

Transpersonal psychology.

During the 1960s Maslow founded with Stanislav Grof, Viktor Frankl, James Fadiman, Anthony Sutich, Miles Vich and Michael Murphy, the school of transpersonal psychology. Maslow had concluded that humanistic psychology was incapable of explaining all aspects of human experience. He identified various mystical, ecstatic, or spiritual states known as "peak experiences" as experiences beyond self-actualization. Maslow called these experiences "a fourth force in psychology", which he named transpersonal psychology. Transpersonal psychology was concerned with the "empirical, scientific study of, and responsible implementation of the finding relevant to, becoming, mystical, ecstatic, and spiritual states" (Olson & Hergenhahn, 2011).  Maslow published in 1962 a collection of papers on this theme, which developed into his 1968 book "Toward a Psychology of Being". In this book Maslow stresses the importance of transpersonal psychology to human beings, writing: "without the transpersonal, we get sick, violent, and nihilistic, or else hopeless and apathetic" (Olson & Hergenhahn, 2011). Human beings, he came to believe, need something bigger than themselves that they are connected to in a naturalistic sense, but not in a religious sense: Maslow himself was an atheist and found it difficult to accept religious experience as valid unless placed in a positivistic framework. In fact, Maslow's position on God and religion was quite complex. While he rejected organized religion and its beliefs, he wrote extensively on the human being's need for the sacred and spoke of God in more philosophical terms, as beauty, truth and goodness, or as a force or a principle.  Awareness of transpersonal psychology became widespread within psychology, and the "Journal of Transpersonal Psychology" was founded in 1969, a year after Abraham Maslow became the president of the American Psychological Association. In the United States, transpersonal psychology encouraged recognition for non-western psychologies, philosophies, and religions, and promoted understanding of "higher states of consciousness", for instance through intense meditation. Transpersonal psychology has been applied in many areas, including transpersonal business studies.

Positive psychology.

Maslow called his work positive psychology. His work has influenced since 1968 the development of Positive Psychotherapy, a transcultural, humanistic based psychodynamic psychotherapy method used in mental health and psychosomatic treatment founded by Nossrat Peseschkian. Since 1999 Maslows work enjoyed a revival of interest and influence among leaders of the positive psychology movement such as Martin Seligman. This movement focuses only on a higher human nature. Positive psychology spends its research looking at the positive side of things and how they go right rather than the pessimistic side.

Psychology of science.

In 1966, Maslow published a pioneering work in the psychology of science "The Psychology of Science: A Reconnaissance", the first book ever actually titled ‘psychology of science’. In this book Maslow proposed a model of ‘characterologically relative’ science, which he characterized as an ardent opposition to the ‘‘historically, philosophically, sociologically and psychologically naıve’’ positivistic reluctance to see science ‘‘relative to time, place, and local culture’’. As Maslow acknowledged, the book was greatly inspired by Thomas Kuhn's "The Structure of Scientific Revolutions" (1962), and it offers a psychological reading of Kuhn's famous distinction between "normal" and "revolutionary" science in the context of his own distinction between "safety" and "growth" science, put forward as part of a larger program for the psychology of science, outlined already in his 1954 "magnum opus" "Motivation and Personality". Not only that Maslow offered a psychological reading of Kuhn's categories of "normal" and "revolutionary" science as an aftermath of Kuhn's "Structure", but he also offered a strikingly similar dichotomous structure of science 16 years before the first edition of "Structure", in his nowadays little known 1946 paper "Means-Centering Versus Problem-Centering in Science" published in the journal "Philosophy of Science".

Maslow's hammer.

Abraham Maslow is also known for Maslow's hammer, popularly phrased as "if all you have is a hammer, everything looks like a nail" from his book "The Psychology of Science", published in 1966.

Criticism.

Maslow's ideas have been criticized for their lack of scientific rigor. He was criticized as too soft scientifically by American empiricists. In 2006, author and former philosophy professor Christina Hoff Sommers and practicing psychiatrist Sally Satel asserted that, due to lack of empirical support, Maslow's ideas have fallen out of fashion and are "no longer taken seriously in the world of academic psychology." Positive psychology spends much of its research looking for how things go right rather than the more pessimistic view point, how things go wrong. Furthermore, the Hierarchy of Needs has been accused of having a cultural bias—mainly reflecting Western values and ideologies. From the perspective of many cultural psychologists, this concept is considered relative to each culture and society and cannot be universally applied. However, according to the University of Illinois researchers Ed Diener and Louis Tay, who put Maslow's ideas to the test with data collected from 60,865 participants in 123 countries around the world over the period of five years (2005-2010), Maslow was essentially right in that there are universal human needs regardless of cultural differences, although the authors claim to have found certain departures from the order of their fulfillment Maslow described. In particular, while they found—clearly in accordance with Maslow—that people tend to achieve basic and safety needs before other needs, as well as that other "higher needs" tend to be fulfilled in a certain order, the order in which they are fulfilled apparently does not strongly influence their subjective well-being (SWB). As put by the authors of the study, humans thus  Maslow, however, would not be surprised by these findings, since he clearly and repeatedly emphasized that the need hierarchy is not a rigid fixed order as it is often presented:  Maslow also regarded that the relationship between different human needs and behaviour, being in fact often motivated simultaneously by multiple needs, is not a one-to-one correspondence, i.e., that "these needs must be understood not to be exclusive or single determiners of certain kinds of behavior".  Maslow's concept of self-actualizing people was united with Piaget's developmental theory to the process of initiation in 1993.

Legacy.

Later in life, Maslow was concerned with questions such as, "Why don't more people self-actualize if their basic needs are met? How can we humanistically understand the problem of evil?"  In the spring of 1961, Maslow and Tony Sutich founded the "Journal of Humanistic Psychology", with Miles Vich as editor until 1971. The journal printed its first issue in early 1961 and continues to publish academic papers.  Maslow attended the Association for Humanistic Psychology's founding meeting in 1963 where he declined nomination as its president, arguing that the new organization should develop an intellectual movement without a leader which resulted in useful strategy during the field's early years.  In 1967, Maslow was named Humanist of the Year by the American Humanist Association.

Abraham Harold Maslow (; April 1, 1908 – June 8, 1970) was an American psychologist who was best known for creating Maslow's hierarchy of needs, a theory of psychological health predicated on fulfilling innate human needs in priority, culminating in self-actualization. Maslow was a psychology professor at Alliant International University, Brandeis University, Brooklyn College, New School for Social Research, and Columbia University. He stressed the importance of focusing on the positive qualities in people, as opposed to treating them as a "bag of symptoms". A "Review of General Psychology" survey, published in 2002, ranked Maslow as the tenth most cited psychologist of the 20th century.

亚伯拉罕·哈罗德·马斯洛(英语:Abraham Harold Maslow,1908年-4月1日-1970年-6月8日),美国心理学家,以需求层次理论最为著名,为一种心理健康的理论,认为首先要满足人类天生的需求,最终达成自我实现。马斯洛曾于布兰戴斯大学、布鲁克林学院、新学院与哥伦比亚大学担任心理学教授。他强调心理学的关注重点在人的正面特质,而不是把人当作是「一袋症状」。


Games.

The games in the series focus on historical events throughout time. "Age of Empires" covers the events between the Stone Age and the Classical period, in Europe and Asia. Its expansion, "", follows the formation and rise of the Roman Empire. "" and its follow Europe and Asia through the Middle Ages. "The Age of Kings" expansion pack, "", is set during the same period, but also includes scenarios about the Spanish conquest of Mexico, El Cid, and Attila the Hun. "Age of Empires III" and its first expansion, "", take place during the European colonization of the Americas. Its second expansion, "", follows the rise of Asia in the same period. Age of Empires Online focuses on the Greek and Egyptian civilizations. The series' spin-off, "Age of Mythology", and its expansion pack, "", are set during the Bronze Age, but focus on mythology as their themes, rather than history.

Main series.

"Age of Empires".

"Age of Empires", released on October 26, 1997, was the first game in the series, as well as the first major release from Ensemble Studios. It was one of the first history-based real-time strategy games made, utilizing the Genie game engine. GameSpot described it as a mix of "Civilization" and "". The game gives players a choice of 12 civilizations to develop from the Stone Age to the Iron Age. The expansion pack, "The Rise of Rome", published by Microsoft on October 31, 1998, introduced new features and four new civilizations, including the Romans. Although the two games had contained many software bugs, patches resolved many of the problems.  "Age of Empires" was generally well received, despite some highly negative reviews. GameSpot criticized a confused design, while "Computer and Video Games" praised the game as strong in single and multiplayer. The Academy of Interactive Arts & Sciences named "Age of Empires" the 1998 "Computer Strategy Game of the Year." For several years, the game remained high on the sales charts, with over three million units sold by 2000. "The Rise of Rome" sold one million units in 2000 and attained 80% as an score from GameRankings.  In June 2017, Adam Isgreen, creative director of Xbox Game Studios announced "Age of Empires: Definitive Edition" at the Electronic Entertainment Expo 2017. It will feature overhauled graphics with support for 4K resolution, a remastered soundtrack, and other gameplay improvements, and was planned to be released on October 19, 2017, but was delayed until February 20, 2018, when it was released on the Microsoft Store. On May 30, 2019, Microsoft announced that the Definitive Edition would be coming to Steam in the future, along with the Definitive Editions of both Age of Empires II and Age of Empires III.

"Age of Empires II".

"Age of Empires II: The Age of Kings", released on September 30, 1999, used the Genie game engine, and had gameplay similar to its predecessor. "Age of Kings" is set in the Middle Ages, from the Dark Ages to the Imperial Age. It allows players to choose one of 13 civilizations, from Europe, Asia, and the Middle East.  On August 24, 2000, Microsoft published the expansion, "The Conquerors". It added new units and five new civilizations, including two Mesoamerican civilizations: the Maya and the Aztec. "The Age of Kings" was a bigger critical success than the first two games, with Game Rankings and Metacritic scores of 92%. Microsoft shipped out more than two million copies to retailers, and the game received numerous awards and accolades. Critics agreed that "The Conquerors" expanded well on "The Age of Kings", though issues of unbalanced gameplay were raised. "The Age of Kings" and "The Conquerors" won the 2000 and 2001 "Computer Strategy Game of the Year" awards from the Academy of Interactive Arts & Sciences, respectively.  In April 2013, "" was released on the Steam digital distribution platform for Windows operating systems. The "HD Edition" includes both the original game and the expansion "The Conquerors", as well as updated graphics for high-resolution displays. In November 2013, a second expansion entitled "The Forgotten" was released by Microsoft exclusively for the "HD Edition". A third expansion named "The African Kingdoms" was released by Microsoft in November 2015, also exclusively for the "HD Edition". A fourth expansion entitled "Rise of the Rajas" was released on 19 December 2016. On August 21, 2017, Microsoft announced "".  In June 2019, Adam Isgreen, now the Franchise Creative Director for Age of Empires, shared more information regarding the at the Electronic Entertainment Expo 2019. He confirmed that the Definitive Edition was being developed by Forgotten Empires, Tantalus Media, and Wicked Witch Software. He announced that the game would feature new 4K graphics, Xbox Live support for multiplayer, exclusive achievements, four new civilizations (Bulgarians, Cumans, Lithuanians, Tatars), three new campaigns, a new spectator mode and tournament features, and additional quality of life improvements. It was released on November 14, 2019. Bert Beeckman, co-founder of Forgotten Empires, confirmed on June 12 that Age of Empires II: HD Edition would not be removed from sale after the release of Age of Empires II: Definitive Edition.

"Age of Empires III".

"Age of Empires III", released on October 18, 2005, was built on an improved version of the "Age of Mythology" game engine with the most significant changes being the updated graphics engine and the inclusion of the Havok physics middleware engine. The game is set in the period between 1421 and 1850, and players can choose one of eight European nations. The game introduced a large number of features, such as home cities. Described by Ensemble Studios as "an important support system to your efforts in the New World," home cities help provide the player with resources, equipment, troops, and upgrades. They can be used across multiple games, and upgraded after each battle; the feature was compared to a role-playing game character by Ensemble Studios. The first expansion to "Age of Empires III", "The WarChiefs", was released October 17, 2006. Most gameplay changes in the expansion pack were small, but it introduced three new civilizations, with a focus on Native Americans. Most notable was the introduction of the unit. The second expansion, "", went on sale October 23, 2007. It was a jointly developed product; Big Huge Games helped Ensemble Studios develop the game, with Brian Reynolds joining Bruce Shelley as lead designer. The game expanded the "Age of Empires III" universe into Asia, and introduced three new civilizations. Reception towards "Age of Empires III" was mixed; Game Revolution described it as "about as much fun" as a history textbook, while GameZone argued it was "one of the best looking games, much less an RTS game, that is out on the market currently". It sold more than two million copies, and won the GameSpy "real-time strategy game of the year" award. "The WarChiefs" failed to equal the success of its predecessor, with a lower score on both Game Rankings and Metacritic, and "The Asian Dynasties"' score was lower still with 80%.  Several collectors' editions of "Age of Empires III" included a hardcover artbook. The last page of the artbook has a pictorial depiction of the series; the Roman numerals below each panel range from I to V, indicating the series would include an "Age of Empires IV" and "Age of Empires V". Ensemble Studios employee Sandy Petersen said that the image "was total speculation on [their] part."  In 2008, Microsoft announced they were closing down Ensemble Studios following the completion of "Halo Wars". Some of its employees would form a new team as part of Microsoft Studios. Kevin Unangst, director of Games for Windows, denied it was the end of the "Age of Empires" series, telling "The San Francisco Chronicle" "we're very excited about the future potential for "Age of Empires"". "Edge" confirmed, in an interview with Microsoft's corporate vice president of interactive entertainment, Shane Kim, that Microsoft continued to own "Age of Empires" and that they had plans to continue the series. However, Bruce Shelley wrote in his blog that he would not be part of any new studios formed.  On August 21, 2017, Microsoft announced "Age of Empires III: Definitive Edition". On May 30, 2019, Microsoft announced that the "Definitive Edition" would be coming to Steam in the future, along with the Definitive Editions of both Age of Empires and Age of Empires II.  On January 23, 2020, Microsoft announced that the closed beta is set to begin in early February of that year. The beta will have a limited rollout, but players can sign up to be an Insider at the official website, and adjust profile settings to get into the pool of invitees. Invites will be distributed by email. Betas will run on both Steam and the Microsoft Store, and each beta session will include a small piece of the game. Larger numbers of invites will be distributed for beta sessions in March. There will be campaign betas, as well, but these will be limited to an even smaller group of players.  The first closed beta session began on February 11, 2020 and ended on February 19, 2020. The second closed multiplayer session began on March 31 and will run through April 7.

"Age of Empires IV".

On August 21, 2017, Microsoft announced "Age of Empires IV", developed by Relic Entertainment. Microsoft's Executive Vice-President of Gaming, Phil Spencer, confirmed on June 11, 2019, that "Age of Empires IV" is still in development, with more information coming later in 2019. On November 14, 2019, gameplay footage of "Age of Empires IV" was shown at the XO19 event. It showed medieval warfare between English and Mongol forces. The release of "Age of Empires IV" is rumored to be in 2021.

Spin-off games.

"Age of Mythology" shared many elements of gameplay with the main series, and was considered a part of the series, despite its different focus. The campaign in "Age of Mythology" tells the story of an Atlantean, Arkantos, and his quest to find why his people are out of favor with Poseidon. Microsoft published the game on October 30, 2002, and its expansion, "The Titans", on October 21, 2003. "The Titans" featured the Atlanteans as a new civilization. Its campaign is shorter than previous expansions, and centers on Kastor, son of Arkantos, who falls for the lies of the titans and frees them from Tartarus. "Age of Mythology" sold more than one million units in four months. It scored 89% on Game Rankings and Metacritic. "The Titans" failed to equal the sales success of "Age of Mythology", although critics rated it highly.  Backbone Entertainment developed "" as a turn-based game for the Nintendo DS. Majesco Entertainment published the game on February 14, 2006. It is similar to other turn-based games, such as "Advance Wars", but with a gameplay based on its PC. "Age of Empires: The Age of Kings" scored 80% on Game Rankings and Metacritic. Konami brought a game of the same title to the PlayStation 2 around five years earlier than the DS version, but the game had little promotion, and sold poorly.  On August 16, 2010, Microsoft announced "Age of Empires Online", which was a free-to-play Games for Windows Live online game, it developed in collaboration with Robot Entertainment. It featured Free-to-play experiences via Games for Windows LIVE as well as: A persistent online capital city that lives and grows even when you're offline, Cooperative multiplayer quests, trading and a level-based system that lets you progress at your own pace. Premium content could be earned or purchased, such as access to blueprints and special items, as well as more quests and features. In September 2013, it was announced that the game would remain functional until July 1, 2014, after which it would be shut down due to the content being too expensive to maintain.  On April 13, 2014, "" was announced. It was developed by KLab Games for the iOS, Android and Windows Phone. It was released on December 7, 2015, with the service terminated on 30 November 2016.  On August 25, 2014, "" was announced. It is a touch-based game developed by Smoking Gun Interactive. It was released on September 17, 2014 for the Windows PC and Windows Phone 8.

Development.

Historical elements.

The development phases of the "Age of Empires" games were similar in several ways. Due to the games being based on historical events, the team often had to do large amounts of research. However, the research was not in depth, which, according to "Age of Empires" designer Bruce Shelley, is "a good idea for most entertainment products." Shelley also said that Ensemble Studios took most of the reference material from children's sections at libraries. He pointed out the goal was for the players of the game to have fun, "not [its] designers or researchers." At the Games Convention Developers Conference in 2007, Shelley continued with this thought and explained that the success of the series laid in "making a game which appealed to both the casual and hardcore gamer." Shelley also remarked the "Age of Empires" games were not about history in itself, but rather "about the human experience;" they focused not simply on what humans had done but on what they could do in the future such as "going into space." Ensemble Studios developed "Age of Mythology" in a different way than the previous two games. The team had worried they "couldn't get away" with a third historical-based game, and chose mythology as the setting after they had discussed several options.

Artificial intelligence.

The artificial intelligence (AI) used in the "Age of Empires" series has been developed and improved regularly by designers. AI specialist Dave Pottinger noted the development team gave the AI in the original game a very high priority, and spent over a year working on it. He said that the AI in the game relies on tactics and strategies to win, instead of "cheating" by giving bonus resources to itself, or tweaking its units to be stronger than normal. Pottinger later noted that the "Age of Empires" series team took great pride in their AI playing a "fair game" and didn't know what the player was doing and had to play by the same rules as its human opponents.  "Age of Empires" allows players to choose to play either along specialized, story-backed conditions or as individual battles against the AI (and other players). Choosing to battle against the AI – rather than following the storyline – allows the AI to adapt to players' strategies and even remember which games it won and lost. The AI eventually overcomes players' strategies and easily destroys their villages after several games. For instance, in "Age of Empires III," this is referred to as playing a "Skirmish." However "Age of Empires III" allows players to refine their strategies further against the AI by "Building a Deck," which allows players to replace "Home City" shipments with improved alternatives.  In "Age of Empires II: The Conquerors" the AI was given a high priority, the result being the "smart villager" feature, which was included in subsequent games of the series. After building a structure that stores or produces resources, smart villagers would proceed to collect resources related to the structure, such as crops from farms or ore from exposed deposits.  "Age of Mythology: The Titans" lets players use an AI debugger when creating custom scenarios; players can change the settings of computer players and make them act according to certain patterns. More basic changes to the AI had previously been available in the series' first two games.

Graphics and visuals.

The graphics and visuals of "Age of Empires" improved with each successive release. From the original release to the second, "Age of Empires II: The Age of Kings," noteworthy improvements gained praise from several critics. With the release of "Age of Mythology" the praise continued, and the fourth release, "Age of Empires III," garnered even more.  GameSpot praised the improved graphics in the second release, "Age of Empires II: The Age of Kings." Eurogamer welcomed its introduction of female villagers as compared with the original male only version. Allgame praised the advanced grouping and path-finding systems in the second release. Despite the improved graphics, Allgame complained that units in "Age of Empires II: The Age of Kings" were at times difficult to distinguish from one another, a point numerous reviewers agreed on. Nevertheless, Game Revolution wrote that the second release was "the best looking of the 2D RTS games out there right now."  The graphics continued to improve in "Age of Mythology" and was praised by a majority of reviewers. IGN ranked the graphics in this third release, "a joy to watch... awesome." GameSpot assented, also rating the graphics a 9 out of 10. Game Revolution agreed, and PC Gamer stated that the graphics in the third release "are packed with detail."  The trend in improved graphics continued well into the next release, "Age of Empires III," much to the delight of reviewers. IGN stated, "After seeing the screenshots, our jaws hit the floor at the amount of detail." "1UP.com" described "Age of Empires III" as "one of the most beautiful games you will put on your computer for the foreseeable future." GameSpy agreed, stating, ""Age III"s graphics are unmatched in the strategy genre." "Age of Empires III" builds on and introduces new features to the prior release, "Age of Mythology," such as the inclusion of the award-winning Havok physics simulation middleware game engine for the Windows version and PhysX for the Mac OS X. The innovative result is that pre-created animations are avoided; instead events are calculated according to the physics engine. Consequently, views of events like building destruction and tree felling are not pre-recorded. GameSpot also admired the graphics in the fourth release but complained about "the awkward unit behavior." Other graphical features of the game include bloom lighting and support for pixel shader 3.0.  GameSpy awarded "Age of Empires III" the "Best Graphics" award at GameSpy's "Game of the Year 2005."

Music.

Stephen Rippy has been the series' music director since the first game. He has had occasional help from his brother, David Rippy, as well as Kevin McMullan. He created the original music in "Age of Empires" with sounds of instruments from the periods in the game. These sounds came from actual instruments, and their digital samples. The tunes were the result of extensive research on the cultures, styles, and instruments used. Rippy said that sound development on "The Age of Kings" was easy, since there was knowledge of the instruments used in the Middle Ages. Therefore, they were able to reproduce the tunes for the soundtrack of the game. In "Age of Mythology", an orchestral instrumentation was used, instead. According to McMullan, the team also collected large numbers of audio recordings from zoos, and created "a massive sound library of [their] own material." The music of "Age of Empires III" was similar to "The Age of Kings", in which the team used more historical instruments; Rippy noted the team used instruments such as "bagpipes and field drums" to give it a realistic feel.

Collaboration.

Ensemble Studios worked together with Big Huge Games to develop "The Asian Dynasties", "Age of Empires III"s second expansion. This was the first joint venture for both teams. The reason for them doing so was compatible schedules: Ensemble Studios was busy with other projects—particularly "Halo Wars"—while Big Huge Games' real-time strategy team had few projects at that time. Big Huge Games did most of the work, but Ensemble Studios designers Greg Street and Sandy Petersen joined in the brainstorming, and had control over the final product. Both studios had roles in testing the game before its release.

Reception and legacy.

The "Age of Empires" series has been a commercial success. As of 2008, five of its games have each sold more than one million copies. According to Gamasutra, "Age of Empires" had sold more than three million copies, and "The Rise of Rome" sold one million copies as of 2000. Around the same time, Microsoft announced that they shipped over two million copies of "The Age of Kings". In 2003, Microsoft announced the sales of one million copies for "Age of Mythology". By 2004—prior to the release of "Age of Empires III"—the "Age of Empires" franchise had sold over 15 million copies. On May 18, 2007, Ensemble Studios announced that two million copies of "Age of Empires III" had been sold. Games in the series have consistently scored highly on video game review aggregator websites GameRankings and Metacritic, which collect data from numerous review websites. As noted in the adjacent table, the highest rating game is "Age of Empires II: The Age of Kings", receiving a 92% score from both sites.  Critics have credited "Age of Empires" for influencing real-time strategy (RTS) games such as "Rise of Nations", "Empire Earth", and "". "" was also influenced by the series: it utilized the Genie game engine, as "Age of Empires" and "Age of Empires II: The Age of Kings" had, and was considered by critics to be a very close replica to the games; IGN began their review with the statement "I love "Age of Star Wars", I mean "Star Empires". Whatever it's called, I dig it." and GameSpot wrote that "fundamentals of the "Age of Empires II" engine are so intact in "Star Wars: Galactic Battlegrounds" that veterans of that game can jump right in." In October 2005, Shelley commented on the impact of the series. In a GameSpy interview, he explained that parents would "tell Ensemble Studios that their kid is reading books about ancient Greece because they enjoy playing with the triremes so much, or that they want to check out books about medieval history because [the] game taught them what a trebuchet was."  Shelley has said that the key to the success of the games was its innovation, rather than imitation of its peers. He also claimed the unique elements in the games "helped establish the reputation of Ensemble Studios as masters of the real-time strategy genre." Mark Bozon of IGN wrote in his review of "The Age of Kings", "The "Age of Empires" series has been one of the most innovative real-time strategy games for PC in the last decade or so." Gamenikki called Ensemble Studios "the developer that started it all" when they talked about how much "Age of Empires III" had done to advance the real-time strategy genre. Shelley has acknowledged the success and innovation of "Age of Empires" helped to ensure Ensemble survive its early periods since startup. In 2005, Shelley complained of critics holding an "innovation bias" against the series; citing the 60% score from "Computer Gaming World", he said that despite "Age of Empires III" being "perhaps the best selling PC game in the world", reviewers expected "something really new", and rated it harshly.  Bungie chose Ensemble Studios to develop "Halo Wars", an RTS game based on their "Halo" series. They said that one of the reasons they chose to work with Ensemble was because of the "Age of Empires" series. They also noted that Ensemble was the perfect choice "to realize the original vision of "Halo"", which started life as an RTS.

Age of Empires is a series of historical real-time strategy video games, originally developed by Ensemble Studios and published by Xbox Game Studios. The first game of the series was "Age of Empires", released in 1997. Seven other games and three spin-offs have been released.

系列是历史题材即时战略电子游戏系列,最初由全效工作室开发、微软工作室发行。系列首款游戏是于1997年推出的《世纪帝国》。帝国时代主系列由3款游戏及其资料片组成。此外,帝国时代系列还包含了5款分支游戏。


Early history.

One of the first cases of carpet bombing was by the Nazi German Condor Legion during the Spanish Civil War against Republican infantry during the Battle of El Mazuco, fought between 6 and 22 September 1937, where the targeted troops were dispersed on rocky slopes and the Condor Legion learned that carpet bombing was not very effective in such terrain.  However, from 16 through 18 March 1938, the Bombing of Barcelona took place successfully, when a series of Fascist Italian and Nazi German airstrikes killed up to 1,300 people and left at least 2,000 wounded. They were carefully designed and recorded, gathering crucial information in preparation for the European War that was around the corner. It is considered the first carpet bombing from air in history, and a sad precedent of several such bombings in World War II carried out by both parties.

During World War II.

In the European Theatre, the first city to suffer heavily from aerial bombardment was Warsaw, on 25 September 1939. Continuing this trend in warfare, the Rotterdam Blitz was an aerial bombardment of Rotterdam by 90 bombers of the German Air Force on 14 May 1940, during the German invasion of the Netherlands. The objective was to support the German assault on the city, break Dutch resistance, and force the Dutch to surrender. Despite a ceasefire, the bombing destroyed almost the entire historic city centre, killing nearly nine hundred civilians and leaving 30,000 people homeless. The destructive success of the bombing led the "Oberkommando der Luftwaffe" (OKL) to threaten to destroy the city of Utrecht if the Dutch Government did not surrender. The Dutch capitulated early the next morning.  As the war progressed, the Battle of Britain developed from a fight for air supremacy into the strategic and aerial bombing of London, Coventry and other British cities. In retaliation for this, the British built up the RAF Bomber Command, which was capable of delivering many thousands of tons of bombs onto a single target, in spite of heavy initial bomber casualties in 1940. The bomber force was then wielded by Arthur Travers Harris in an effort to break German morale and obtain the surrender which Douhet had predicted 15 years earlier. The United States joined the war and the USAAF greatly reinforced the campaign, bringing in the Eighth Air Force into the European Theatre. Many cities, both large and small, were virtually destroyed by Allied bombing. Cologne, Berlin, Hamburg and Dresden are among the most infamous, the latter two developing firestorms. W. G. Sebald's book, "On the Natural History of Destruction", comments on the carpet bombing of German cities and asks why it does not play a larger part in the German national consciousness, and why virtually no German authors have written about the events. Despite the lack of literary coverage, a style of film, the rubble film, shot among the urban debris and depicting the gritty lives of those who had to rebuild the destroyed cities, developed in the years after the end of World War II.  Carpet bombing was also used as close air support (as "flying artillery") for ground operations. Massive bombing was concentrated in a narrow and shallow area of the front (a few kilometers by a few hundred meters deep), closely coordinated with the advance of friendly troops. The first successful use of the technique was on 6 May 1943, at the end of the Tunisia Campaign. Carried out under Sir Arthur Tedder, it was hailed by the press as Tedder's bomb-carpet (or Tedder's carpet). The bombing was concentrated in a four by three-mile area, preparing the way for the First Army. This tactic was later used in many cases in the Normandy Campaign; for example, in the Battle for Caen.  In the Pacific War, carpet bombing was used extensively against Japanese civilian population centers, such as Tokyo. On the night of 9–10 March 1945, 334 B-29 Superfortress heavy bombers were directed to attack the most heavily populated civilian sectors of Tokyo. In just one night, over 100,000 people burned to death from a heavy bombardment of incendiary bombs, comparable to the wartime number of U.S. casualties in the entire Pacific theater. Another 100,000 to one million Japanese were left homeless. These attacks were followed by similar ones against Kobe, Osaka, and Nagoya, as well as other sectors of Tokyo, where over 9,373 tons of incendiary bombs were dropped on civilian and military targets. By the time of the dropping of the atomic bombs on Hiroshima and Nagasaki, light and medium bombers were being directed to bomb targets of convenience, as most urban areas had already been destroyed. In the 9-month long civilian bombing campaign, over 400,000 Japanese civilians died.

Vietnam War.

During the Vietnam War, with the escalating situation in Southeast Asia, twenty-eight B-52Fs were fitted with external racks for twenty-four 750-pound (340 kg) bombs under project "South Bay" in June 1964; an additional forty-six aircraft received similar modifications under project "Sun Bath". In March 1965, the United States commenced Operation Rolling Thunder. The first combat mission, Operation Arc Light, was flown by B-52Fs on 18 June 1965, when 30 bombers of the 9th and 441st Bombardment Squadrons struck a communist stronghold near the Bến Cát District in South Vietnam. The first wave of bombers arrived too early at a designated rendezvous point, and while maneuvering to maintain station, two B-52s collided, which resulted in the loss of both bombers and eight crewmen. The remaining bombers, minus one more that turned back for mechanical problems, continued toward the target. Twenty-seven Stratofortresses dropped on a one-mile by two-mile target box from between 19,000 and 22,000 feet, a little more than 50% of the bombs falling within the target zone. The force returned to Andersen AFB except for one bomber with electrical problems that recovered to Clark AFB, the mission having lasted 13 hours. Post-strike assessment by teams of South Vietnamese troops with American advisors found evidence that the VC had departed the area before the raid, and it was suspected that infiltration of the south's forces may have tipped off the north because of the ARVN troops involved in the post-strike inspection.  Beginning in late 1965, a number of B-52Ds underwent "Big Belly" modifications to increase bomb capacity for carpet bombings. While the external payload remained at twenty-four 500-pound (227 kg) or 750-pound (340 kg) bombs, the internal capacity increased from twenty-seven to eighty-four 500-pound bombs or from twenty-seven to forty-two 750-pound bombs. The modification created enough capacity for a total of 60,000 pounds (27,215 kg) in one hundred eight bombs. Thus modified, B-52Ds could carry 22,000 pounds (9,980 kg) more than B-52Fs. Designed to replace B-52Fs, modified B-52Ds entered combat in April 1966 flying from Andersen Air Force Base, Guam. Each bombing mission lasted 10 to 12 hours with an aerial refueling by KC-135 Stratotankers. In spring 1967, the aircraft began flying from U Tapao Airfield in Thailand giving the aircraft the advantage of not requiring in-flight refueling.  The zenith of B-52 attacks in Vietnam was "Operation Linebacker II" (sometimes referred to as the Christmas Bombing) which consisted of waves of B-52s (mostly D models, but some Gs without jamming equipment and with a smaller bomb load). Over 12 days, B-52s flew 729 sorties and dropped 15,237 tons of bombs on Hanoi, Haiphong, and other targets. Originally 42 B-52s were committed to the war; however, numbers were frequently twice this figure.

Carpet bombing, also known as saturation bombing, is a large area bombardment done in a progressive manner to inflict damage in every part of a selected area of land. The phrase evokes the image of explosions completely covering an area, in the same way that a carpet covers a floor. Carpet bombing is usually achieved by dropping many unguided bombs.

地毯式轰炸指像在地板上铺地毯一样地使用大量的无制导炸弹覆盖轰炸某一地域,杀伤和摧毁该地域的人员、装备。当地毯式轰炸的目标为人口或工业聚集区时,意在达成打击对方出租车气和战争潜力这一战略目的。