10154529
Comparing uniform and flexible policies for software maintenance and replacement
The importance of software maintenance in managing the life-cycle costs of a system cannot be overemphasized. Beyond a point, however, it is better to replace a system rather than maintain it. We derive model and operating policy that reduces the sum of maintenance and replacement costs in the useful life of a software system. The main goal is to compare uniform (occurring at fixed time intervals) versus flexible (occurring at varying, planned time intervals) polices for maintenance and replacement. The model draws from the empirical works of earlier researchers to consider 1) inclusion of user requests for maintenance, 2) scale economies in software maintenance, 3) efficiencies derived from replacing old software technology with new software technology, and 4) the impact of software reuse on replacement and maintenance. Results from our model show that the traditional practice of maintaining or replacing a software system at uniform time intervals may not be optimal. We also find that an increase in software reuse leads to more frequent replacement, but the number of maintenance activities is not significantly impacted.
14496219
Optimal Processing Policies for an e-Commerce Web Server
The explosive growth in online shopping has provided online retailers impressive opportunities to extend revenue and profit. However, retailers may lose considerable online business from slow response times at electronic shopping sites. Although increasing server capacity may improve response time, the resources needed to do so are clearly not free. In this study, we propose a scheme that can improve a server's performance with no more than its current capacity. This scheme is based on priority processing, where the priority assigned to a customer depends on the potential revenue that is likely to be generated from the customer. The results for single-period analysis show that the benefit from priority processing increases as the server becomes more heavily utilized. 
 
We have also modeled a multiperiod version of the problem, where the demand in a period depends on the quality of service (QoS) that buyers receive in the previous period. In the multiperiod problem, both the server capacity and the processing policy in each period are determined optimally. Here, it may be optimal for the retailer to sacrifice profit and increase QoS in initial periods in order to increase demand (and revenue) in later periods. Thus, the processing policy of the server evolves from an emphasis on QoS in initial periods, to one on profit in subsequent periods.
5556167
A color histogram based people tracking system
A system using color histogram based recognition technique is presented for tracking of moving people. The proposed system aims to resolve the identity of each tracked person after an occlusion, which is a common problem encountered in tracking of multiple objects. The system recognizes and keeps track of moving people with the aid of their color histograms. To make the recognition more robust against change of background illumination, a shadow-removal scheme is designed to select only those pixels belonging to the tracked people for constructing their color histograms. Experimental results of real video data are reported to show the efficacy of the proposed system.
35355701
Methods and needs for transcoding MPEG-4 fine granularity scalability video
We discuss the methods and needs for transcoding MPEG-4 fine granularity scalability (FGS) video. FGS is a scalable video-coding technique recently adopted by the MPEG-4 compression standard. The main feature of FGS coding is that a part of the video bit stream, namely the enhancement layer, can be truncated at any desirable number of bits to support continuous quality/bit-rate scalability. However, not every decoder would support FGS functions and the coding efficiency of FGS video is known to be inferior to that of non-scalable video. This paper proposes methods for transcoding FGS video and restoring, as much as possible, the coding efficiency that is lost in FGS coding. In particular, it is shown that there are cases where extra gain of video quality is possible by exploiting the FGS enhancement layer in the transcoding process. To some extend, the proposed transcoding methods can support spatial scalability that is lacking in FGS coding. Experiments have been conducted and the results are reported to demonstrate the advantages of the proposed transcoding schemes for FGS video.
31919378
A risk management of ASPs
Application service providers (ASPs) provide access to application software over wide area networks and have been viewed as a means of making the benefits of outsourcing available to small businesses. However, many enterprise ASPs get the majority of their revenue from very large businesses while many vertical niche ASPs get their revenue from small businesses. We analyze this seeming anomaly from a risk management perspective. ASPs present a greater risk management problem to would-be customers than traditional outsourcing. We analyze the nature of the risk differences and then propose a model of how would-be customers process those risks. In our model, prospects first assess whether they can tolerate the worst case scenario and if they are able to do due diligence on the likely outcome. They consider benefits only if one of the previous assertions is true. The worst case scenario for enterprise applications is truly dire and only technologically sophisticated businesses are better able to identify the true risk profile. For vertical niche ASPs the worst case scenario is relatively mild, but economies of scale make the benefits relatively more appealing to small businesses.
27936359
A new content-based hybrid video transcoding method
Many video transcoding architectures have been proposed to reduce the bitrates of compressed video bitstreams. Requantization of transformed coefficients (such as DCT coefficients), spatial resolution down-sampling, and temporal resolution down-sampling are the three transcoding tools which are commonly used to reduce compressed video bitrates. We propose a new video transcoding method that combines the use of different transcoding tools to transcode compressed video bit streams to various target bitrates while maintaining good subjective/objective video quality. The transcoding tools are selected based on the video content, which is characterized by two video content descriptors inferring the video spatial and motion activities, respectively. These two content descriptors can be readily computed from the compressed video bit streams without full decompression. Experimental results show that the proposed method can provide better video quality than other existing transcoders that make use of a single transcoding tool.
33005423
Unsupervised clustering of dominant scenes in sports video
We propose a new and efficient approach for clustering dominant scenes in sports video. To perform clustering in an unsupervised manner, we devise a recursive peer-group filtering (PGF) scheme to identify prototypical shots for each dominant scene, and examine time coverage of these prototypical shots to decide the number of dominant scenes for each sports video under analysis. To improve clustering efficiency, we employ principal component analysis and linear discriminant analysis to project high dimensional shot features to lower dimensional spaces suitable for classification. The main contribution of the paper lies in the formulation of clustering dominant scenes in sports video and the development of an efficient, unsupervised solution making use of PGF, time-coverage criterion, and subspace analysis. Experimental results obtained from various types of sports videos are presented to show the efficacy of the proposed approach.