13648929
Database design in the modern organization - identifying robust structures under changing query patterns and arrival rate conditions
We summarize the problem tackled here in the following way: Given a modern database application environment, how can we identify and select the database structure that provides robust performance across changing query patterns and arrival rate conditions? We demonstrate the importance of investigating the underlying relationships and then utilize this information in formulating robust structures. Our work is pre-theory in the philosophy of science sense. That is, the careful identification and observation of relationships will subsequently be utilized in formulating a testable theory of the development of robust database structures under dynamic query patterns and arrival rates. Our first step in providing a database design or "structure selection" method is to determine potential good performers among different database structures. These potential good performers are selected and analyzed across arrays of query patterns. The next step is to identify database structures that are robust structures, that is good performers across the different types of query patterns and arrival rate levels. The presentation includes illustrations of the determination of actual query pattern processing times and the use of these times within a queuing analysis. In fact, for the database layout analyzed, application of our methods demonstrates the existence of such robust database structures.
7914809
Predicting Bidders' Willingness to Pay in Online Multiunit Ascending Auctions: Analytical and Empirical Insights
We develop a real-time estimation approach to predict bidders' maximum willingness to pay in a multiunit ascending uniform-price and discriminatory-price (Yankee) online auction. Our two-stage approach begins with a bidder classification step, which is followed by an analytical prediction model. The classification model identifies bidders as either adopting a myopic best-response (MBR) bidding strategy or a non-MBR strategy. We then use a generalized bid-inversion function to estimate the willingness to pay for MBR bidders. We empirically validate our two-stage approach using data from two popular online auction sites. Our joint classification-and-prediction approach outperforms two other naive prediction strategies that draw random valuations between a bidder's current bid and the known market upper bound. Our prediction results indicate that, on average, our estimates are within 2% of bidders' revealed willingness to pay for Yankee and uniform-price multiunit auctions. We discuss how our results can facilitate mechanism-design changes such as dynamic-bid increments and dynamic buy-it-now prices.
17233820
IT-enabled transparent electronic markets: the case of the air travel industry
The electronic market hypothesis predicts that by reducing coordination costs, information technology (IT) will shift industrial organization from hierarchical to market-based forms of economic activity. While academic researchers and practitioners have witnessed these shifts with the advent of the Internet, there is little understanding about the process and the underlying forces that drive them. In this paper, we provide an in-depth analysis of the air travel industry, which has recently experienced significant IT-driven transformations. We conclude that, together with IT, pro-competitive laws and the information-intensive nature of air travel products have triggered competition for consumers with transparent market mechanisms, which is leading to the emergence of more transparent electronic markets in the air travel industry.
30721210
Economic analysis of consumer purchase intentions in electronic and traditional retail channels: competitive and strategic implications
We develop a multiattribute economic model to analyze consumer behavior for traditional and electronic channels based on consumers' risk profiles and risk-neutral or risk-averse. We then conduct comparative analyses of consumer purchase decisions to derive strategies for different channels. We study the attitudinal and economic factors that lead to specific purchase decisions under different combinations of price, delivery time, and product customization. We develop theoretical propositions concerning consumer channel switching behavior, incentives to consumers, and pricing strategies for different channels. We also use simulations to gain insights for cases where analytical model becomes intractable.
166893960
Priority pricing of integrated services networks
57631
Insights and analyses of online auctions
5988621
Motion estimation using ordinal measures
We present a method for motion estimation using ordinal measures. Ordinal measures are based on relative ordering of intensity values in an image region called rank permutation. While popular measures like the sum-of-squared-difference (SSD) and normalized correlation (NCC) rely on linearity between corresponding intensity values, ordinal measures only require them to be monotonically related so that rank permutations between corresponding regions are presented. This property turns out to be useful for motion estimation in tagged magnetic resonance images. We study the imaging equation involved in two methods of tagging and observe temporal monotonicity in intensity under certain conditions though the tags themselves fade. We compare our method to SSD and NCC in a rotating ring phantom image sequence. We present an experiment on a real heart image sequence which suggests the suitability of our method.
321445
Detection of Masquerade Attacks on Wireless Sensor Networks
We propose two lightweight techniques to detect masquerade attacks on wireless sensor networks (WSN). Our solutions take into consideration, important WSN properties like coverage, connectivity, data aggregation and specific communication patterns. The two proposed techniques complement each other when used concurrently. The mutual guarding (MG) technique does not work when nodes are not completely covered by their neighbors or when adversary has shorter transmission range than the sensor nodes. It also does not protect nodes near the boundary. The SRP technique does not have these drawbacks. In this paper, we present our proposed techniques and analyze their performance in terms of successful masquerade detection rate and traffic and computational overhead.
107769190
Hack I.T. - Security Through Penetration Testing
Hack I.T. introduces penetration testing and its vital role in an overall network security plan. You will learn about the roles and responsibilities of a penetration testing professional, the motivation and strategies of the underground hack community, and potential system vulnerabilities, along with corresponding avenues of attack. Most importantly, the book provides a framework for performing penetration testing and offers step-by-step descriptions of each stage in the process. The latest information on the necessary hardware for performing penetrating testing, as well as an extensive reference on the available security tools, is included.
19327594
Mobility-Pattern-Based Anomaly Detection Algorithm in Mobile Networks
Numerous approaches have been proposed for intrusion detection in immobile networks. However, little research work has been done in actually implementing them, especially for anomaly detection, in mobile networks. In this paper, we present an efficient mobility-pattern-based (MPB) anomaly detection algorithm. It can effectively identify abnormal mobility patterns of the nodes in mobile networks. In the proposed algorithm, the normal mobility profile of a specific node is characterized by a multi-leaf tree structure in which each node corresponds to a possible destination cluster. A normal mobility profile is generated during the training process through data mining and fuzzy logic techniques. More specifically, data mining techniques are used for cluster classifications, and fuzzy logic techniques are used to integrate the 'similar'' pattern strings after the corresponding cluster generation. These two techniques are also used during the testing process for distinguishing abnormal mobility patterns of the node from those of the normal in mobile networks. Simulation results demonstrate that our proposed MPB anomaly detection algorithm can achieve good performance in terms of detection rate and false alarm rate for nodes with regular movement behaviors by fine tuning the design parameter - threshold, that can be chosen efficiently.
29871849
Optimal Deployment of Triggers for Detecting Events
In active d atabases, rules are represented in the form of ECA (event-condition-action). Database events can be detected by defining triggers on the underlying application databases. Many-a-times, temporal conditions that limit the validity period of the event are as sociated with the ECA rule. The performance of the database can get adversely affected if such temporal constraints are checked (either at the application level or at database level) for every transaction (event) irrespective of whether that transaction (event) has occurred within the said time interval. This drawback can be avoided by optimizing the temporal constraints associated with the sub-events of a composite event based on the semantics of the composite event operators. This paper describes such an algorithm that optimizes the temporal constraints associated with (composite) events and improves the efficiency of the databases by creating and destroying triggers dynamically such that the semantics of the event is unchanged. The efficiency of the technique is validated by our experimental results.