25000873
Design, analysis, and implementation of an agent driven pull-based distributed video-on-demand system
The problem of employing multiple servers to serve a pool of clients on a network based multimedia service is addressed. We have designed and practically implemented a prototype system employing multiple servers to render a long duration movie to the customers. We have employed a multiple server retrieval strategy proposed in the literature [39] to realize this system. In the system, server coordination, client behavior and service facilities are completely controlled by an Agent based approach in which we have used the recent Jini technology. Several issues, ranging from data retrieval from individual server, behavior of the underlying network infrastructure, to client management and resource (client buffers) management, are considered in this implementation. We describe in detail our experiences in this complete design process of every module in the software architecture, its purpose, and working style. Further, the system is shown to be robust amidst unpredictable failures, i.e., in the event of server crashes. The load balancing capability is built-in as a safe guard measure to assure a continuous presentation. We present a comprehensive discussion on the software architecture to realize this working system and present our experiences. A system comprising a series of Pentium III PCs on a fast Ethernet network is built as a test-bed. Through this prototype, a wider scope of research challenges ahead are highlighted as possible extensions.
8575175
A User-Friendly Methodology for Automatic Exploration of Compiler Options
This paper introduces a practical methodology for automatic exploring compiler optimization options. The strategy behind this methodology is to provide an intelligent mechanism, in which the compiler will automatically identify optimized combination of compiler options for a given application. The decision made by the compiler is based on user requirements on what aspects of the generated code are the most critical for the compiled application through a specialized user interface. A set of pre-built databases of candidate optimized combinations of compiler options will help the compiler to make the right decision. This methodology will dramatically help users to get rid of the burden of fully understanding the compiler’s inner structure and organization to make the most profitable combination of options. All this work is taken by the compiler and the infrastructure proposed in this paper. This paper presents this methodology and describes its principles and technical mechanisms of the components.
7148263
User-Friendly Methodology for Automatic Exploration of Compiler Options: A Case Study on the Intel XScale Microarchitecture
A duct adapter for use in conjunction with an air conditioning unit is disclosed. This adapter attaches to a discharge opening of an air conditioning unit and acts to divide the stream of conditioned air into multiple streams, one being discharged into the enclosure containing the air conditioning unit and a separate stream being discharged into a duct for delivery at a distant location. Means for attaching the adapter to the air conditioning unit and a damper assembly therein are additionally disclosed.
206929170
Optimizing the Fast Fourier Transform on a Multi-core Architecture
The rapid revolution in microprocessor chip architecture due to multicore technology is presenting unprecedented challenges to the application developers as well as system software designers: how to best exploit the parallelism potential due to such multi-core architectures? In this paper, we report an in-depth study on such challenges based on our experience of optimizing the fast Fourier transform (FFT) on the IBM Cyclops-64 chip architecture - a large-scale multi-core chip architecture consisting 160 thread units, associated memory banks and an interconnection network that connect them together in a shared memory organization. We demonstrate how multi-core architectures like the C64 could be used to achieve a high performance implementation of FFT both in 1D and 2D cases. We analyze the optimization challenges and opportunities including problem decomposition, load balancing, work distribution, and data-reuse, together with the exploiting of the C64 architecture features such as the multi-level of memory hierarchy and large register files. Furthermore, the experience learned during the hand-tuned optimization process have provided valuable guidance in our compiler optimization design and implementation. The main contributions of this paper include: 1) our study demonstrates that successful optimization for C64-like large-scale multi-core architectures requires a careful analysis that can identify certain domain-specific features of a target application (e.g. FFT) and match them well with some key multi-core architecture features; 2) our optimization, assisted with hand-tuned process, provided quantitative evidence on the importance of each optimization identified in 1); 3) automatic optimization by our compiler, the design and implementation of which is guided by the feedbacks from 1) and 2), shows excellent results that are often comparable to the results derived from our time-consuming hand-tuned code.
28885654
Multimodal human emotion/expression recognition
Recognizing human facial expression and emotion by computer is an interesting and challenging problem. Many have investigated emotional contents in speech alone, or recognition of human facial expressions solely from images. However, relatively little has been done in combining these two modalities for recognizing human emotions. L.C. De Silva et al. (1997) studied human subjects' ability to recognize emotions from viewing video clips of facial expressions and listening to the corresponding emotional speech stimuli. They found that humans recognize some emotions better by audio information, and other emotions better by video. They also proposed an algorithm to integrate both kinds of inputs to mimic human's recognition process. While attempting to implement the algorithm, we encountered difficulties which led us to a different approach. We found these two modalities to be complimentary. By using both, we show it is possible to achieve higher recognition rates than either modality alone.
63481154
MobiMessenger: An Instant Messenger System Based on Mobile Ad-Hoc Network
Mobile ad-hoc network offers many new ways for CSCW resolution. So we develop an ad-hoc instant messenger, MobiMessenger, which will be used as a platform for our future research work on ad-hoc collaboration. In this paper, we present the design and implement of MobiMessenger, which is based on AODV algorithm, including the system architecture and implementation. Also present our future work on ad-hoc collaboration.
12012725
An intelligent control system with a multi-objective self-exploration process
Abstract This paper proposes a novel approach based on artificial intelligence technologies (multi-objective Self-Exploration process based Intelligent Control System—mSEICS) for intelligent control systems. Not only can this system adapt to various environments, but it can also continually improve its performance. The mSEICS consists of four basic functions, controller, receptor, m-adaptor and advancer. A five-layer fuzzy neural network is applied to implement the controller. The receptor is used to evaluate the performance of system. The m-adaptor (multi-objective based adaptor) that comprises two elements, action explorer and rule generator, can generate a variety of new action sets in order to adapt to various environments. The Pareto optimality based multi-objective genetic algorithm is proposed to implement the action explorer to discover multiple action sets, and the rule generator is employed to transform the action set to fuzzy rules. In addition, the advancer consisting of action discoverer and rule generator is constructed to produce the novel action set to enhance the system efficiency. The parallel-simulated annealing approach is presented to realize the action discoverer. An application of the robotic path planning is applied to demonstrate the proposed model. The simulation results show that the mobile robot can reach the target successfully in various environments, and the proposed model is more efficient than the similar model.
7800069
Detection of summative global predicates
In distributed programs, we usually keep some global predicates from being satisfied to make it easy to run the programs correctly. A common type of global predicates are: the total number of certain tokens in the whole distributed system is always the same or in specific ranges. In this paper, we call this summative predicates, classified into the following four: (1) at some global state of the system, N/spl ne/K, (2) NK (or N/spl ges/K), and (4) N=K, where N is the total number of tokens and K is a constant. This paper investigates the methods of detecting various summative global predicates. The first class of summative predicates are trivial to detect by simply checking each message. For the second class of summative predicates, B. Groselj (1993) and V.K. Garg (1995) solved the problem by reducing the problem to a maximum network flow problem. In this paper, we propose an elegant technique, called normalization, to allow the second and third classes of summative predicates to be solved by also reducing the problem to a maximum network flow problem. For the fourth class of summative predicates, we prove that it is an NP-complete problem.
4792658
Active Page Generation via Customizing XML for Data Beans in E-Commerce Applications
In this paper, we analyze enabling technologies for typical e-business applications in terms of their multi-tier system architecture and their Model-Control-View (MCV) programming model. Based on observed limitations of the JSP (Java Server Page) technique commonly adopted for dynamic page generation (the view logic), we instead propose an alternative solution approach, namely, a generic schema mapping strategy to generate XML documents and DTDs from enterprise data beans. First, we describe in detail the XML generation process for the content composition logic. We also outline the XSL processing for the transformation logic. The separation of these two logics results in a generic solution to the bean viewing problem. In particular, it improves the bean reusability via its XML representative compared to the rigid strategy of hard-coding logics into JSP. Our proposed XML mapping solution represents a potentially valuable addition to future versions of the enterprise data beans specification. The trade-off between performance and flexibility of these alternative solutions is discussed. Lastly, we survey the state-of-art research results and emerging stardards related to this XML model mapping approach.