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41.
Local land use regulations have been adopted to restrict population growth and urban sprawl in an attempt to prevent future problems like congestion, pollution, and loss of open space. However, when regulations become widespread in a region, it can be difficult for young workers and newcomers to find appropriate housing in the region. Because local governments may neglect the effects of their policies on the rest of the region, the resulting population size can be inefficient. We show that local adoption of housing regulations tends to over-restrict population growth when there are strong agglomeration economies in the regional production. On the other hand, when there is congestion in production, coordination among jurisdictions is undesirable if business interests are neglected. 相似文献
42.
Chrisphine Sangara Nyamweya Chrisestom Mwatete Mlewa Charles Chege Ngugi Boaz Kaunda‐Arara 《Lakes & Reservoirs: Research and Management》2010,15(4):341-345
The African catfish (Clarias gariepinus) is widely distributed in Africa, where it is a major food fish. The species comprises a significant component of commercial fishery landings in Kenya, and elsewhere in Africa. Nevertheless, little information or data exist on its age and growth characteristics, which is necessary for its sustainable management. This study determined this information from the microstructure of lapillar otoliths of the young‐of‐the‐year (YOY) of the species. Analysis of the otolith microstructure from fish of known age confirmed that one growth increment (circulus) was formed per day, forming the basis for their use to accurately age C. gariepinus YOY collected from Lake Baringo during the months of August and September 2007. The derived length–age relationship correlated significantly (Pearson Correlation, df = 53, P < 0.05), indicating that the YOY exhibited an average growth rate of 0.2285 cm day?1. The largest specimen attained a total length of 40.5 cm in only 169 days. These results indicate that native C. gariepinus exhibits rapid growth, achieving a large size during the first year. Thus, they can be recommended for purposes of aquaculture. 相似文献
43.
Boaz Tsaban 《Information Processing Letters》2006,99(4):145-148
The Diffie-Hellman key agreement protocol is based on taking large powers of a generator of a prime-order cyclic group. Some generators allow faster exponentiation. We show that to a large extent, using the fast generators is as secure as using a randomly chosen generator. On the other hand, we show that if there is some case in which fast generators are less secure, then this could be used by a malicious authority to generate a standard for the Diffie-Hellman key agreement protocol which has a hidden trapdoor. 相似文献
44.
Several state-of-the-art techniques – a neural network, Bayesian neural network, support vector machine and naive Bayesian
classifier – are experimentally evaluated in discriminating fluorescence in situ hybridisation (FISH) signals. Highly-accurate classification of valid signals and artifacts of several cytogenetic probes
(colours) is required for detecting abnormalities in FISH images. More than 3100 FISH signals are classified by each of the
techniques into colour and as real or artifact with accuracies of around 98% and 88%, respectively. The results of the comparison
also show a trade-off between simplicity represented by the naive Bayesian classifier, and high classification performance
represented by the other techniques. 相似文献
45.
Boaz Lerner Lev Koushnir Josepha Yeshaya 《IEEE transactions on information technology in biomedicine》2007,11(4):443-449
Signal segmentation and classification of fluorescence in situ hybridization (FISH) images are essential for the detection of cytogenetic abnormalities. Since current methods are limited to dot-like signal analysis, we propose a methodology for segmentation and classification of dot and non-dot-like signals. First, nuclei are segmented from their background and from each other in order to associate signals with specific isolated nuclei. Second, subsignals composing non-dot-like signals are detected and clustered to signals. Features are measured to the signals and a subset of these features is selected representing the signals to a multiclass classifier. Classification using a naive Bayesian classifier (NBC) or a multilayer perceptron is accomplished. When applied to a FISH image database, dot and non-dot-like signals were segmented almost perfectly and then classified with accuracy of approximately 80% by either of the classifiers. 相似文献
46.
We consider the problem of smoothing real-time streams (such as video streams), where the goal is to reproduce a variable-bandwidth stream remotely, while minimizing bandwidth cost, space requirement, and playback delay. We focus on lossy schedules, where data may be dropped due to limited bandwidth or space. We present the following results. First, we determine the optimal tradeoff between buffer space, smoothing delay, and link bandwidth for lossy smoothing schedules. Specifically, this means that if two of these parameters are given, we can precisely calculate the value for the third which minimizes data loss while avoiding resource wastage. The tradeoff is accomplished by a simple generic algorithm, that allows one some freedom in choosing which data to discard. This algorithm is very easy to implement both at the server and at the client, and it enjoys the nice property that only the server decides which data to discard, and the client needs only to reconstruct the stream.In a second set of results we study the case where different parts of the data have different importance, modeled by assigning a real weight to each packet in the stream. For this setting we use competitive analysis, i.e., we compare the weight delivered by on-line algorithms to the weight of an optimal off-line schedule using the same resources. We prove that a natural greedy algorithm is 4-competitive. We also prove a lower bound of 1.23 on the competitive ratio of any deterministic on-line algorithm. Finally, we give a few experimental results which seem to indicate that smoothing is very effective in practice, and that the greedy algorithm performs very well in the weighted case.Received: 21 November 2001, Accepted: 6 November 2003, Published online: 6 February 2004Research supported in part by Israel Ministry of Science. An extended abstract of this paper appeared in Proc. 19th ACM Symp. on Principles of Distributed Computing, July 2000. 相似文献
47.
This study focuses on the tendency to develop software excessively, above and beyond need or available development resources. The literature pays little attention to this issue, overlooking its crucial impact and penalties. Terms used in reference to excessive software development practices include over-requirement, over-specification, over-design, gold-plating, bells-and-whistles, feature creep, scope creep, requirements creep, featuritis, scope overload and over-scoping. Some of these terms share the same meaning, some overlap, some refer to the development phase, and some to the final system. Via a systematic literature search, we first demonstrate the poor state of research about excessive software development practices in the information systems and project management areas. Then, we suggest a framework consolidating the problems associated with excessive software development in three ‘beyond’ categories (beyond needs, beyond resources, beyond plans), describe and analyze their causes, consequences, boundaries and overlapping zones. Finally, we discuss the findings and present directions for future research. 相似文献
48.
The authors developed a CD-ROM for use in the classroom, the computer lab, the library, or the personal computers of students and faculty. The subject of the CD is an interart study of music, art, and literature, specifically T. S. Eliot's The Waste Land. the authors trace their process of formulating the idea and conceptualizing the project. They also detail the initial stages of the project, including the time-intensive efforts of getting permissions for the materials. For the technology portion, they describe how the components were digitized, integrated, and tested. Finally, they discuss how they manufactured and marketed the product, closing with some evaluative comments.John K. Boaz is Emeritus Associate Vice President for Administrative Services and a former Director of Forensics in the Department of Communication at Illinois State University. He edited a serial for several years for the American Forensic Association and the Speech Communication Association, Championship Debates and Speeches, and he has most recently edited The Adlai E. Stevenson Memorial Lecture Series: The First Twenty five Years, 1966–1991 published by the University Press of America.Mildred M. Boaz, a modern British literature specialist, is Professor of English and Chair of the Department of English at Millikin University. She has published on T. S. Eliot in The Centennial Review and The Journal of Aesthetic Education. She was also a contributor to the Modern Language Association's volume on Approaches to Teaching Eliot's Poetry and Plays.Both are members of the T. S. Eliot Society. 相似文献
49.
Studied the effects of age-segregated hospital environments on cognitive functioning of 55 aged, male psychiatric patients. Changes in performance on mental status and responsiveness measures during the 1st 3 wk. after admission were compared for patients randomly assigned to an age-segregated custodial, age-integrated custodial, and a therapy ward. Ss placed in the age-integrated custodial ward and in the therapy ward showed significantly greater improvement in responsiveness and mental status than Ss placed in the age-segragated custodial ward. Effects of ward placement cut across all diagnostic groups. The therapeutic potential of age-integrated patient environments is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
50.
Converse Benjamin A.; Lin Shuhong; Keysar Boaz; Epley Nicholas 《Canadian Metallurgical Quarterly》2008,8(5):725
Understanding others' behavior often involves attributing mental states to them by using one's "theory of mind." We argue that using theory of mind to recognize differences between one's own perspective and another's perspective is a deliberate process of inference that may be influenced by incidental mood. Because sadness is associated with more systematic and deliberate processing whereas happiness is associated with more heuristic processing, we predicted that theory-of-mind use would be facilitated by sadness compared with happiness. Two experiments supported this prediction, demonstrating that participants were more likely to utilize knowledge about others to make inferences about their mental states when they were induced to feel sad than when they were induced to feel happy. These results provide both theoretical insight into the psychological mechanisms that govern theory of mind as well as practical insight into a common source of variability in its use. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献