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1.
The object of the experiment described in this paper was to assess the value of information for individual searchers in a realistic search environment. An additive linear function, which combined the ratings of information features provided by searchers, was used to model how humans value information. Twenty Industrial Engineering graduate students and faculty, who were attempting to satisfy a genuine information need by searching a data base of technical literature on Operations Research, served as experimental subjects. Included in the data analysis are a comparison of two alternative retrieval methods, an evaluation of how well humans are able to estimate the relevance of a document from the document's features, and an investigation of the value function components (features and coefficients) and functional form. 相似文献
2.
Reza Gharibi Amir Hossein Rasekh Mohammad Hadi Sadreddini Seyed Mostafa Fakhrahmad 《Information processing & management》2018,54(6):1058-1076
Bug reports are an essential part of a software project's life cycle since resolving them improves the project's quality. When a new bug report is received, developers usually need to reproduce the bug and perform code review to locate the bug and assign it to be fixed. However, the huge number of bug reports and the increasing size of software projects make this process tedious and time-consuming. To solve this issue, bug localization techniques try to rank all the source files of a project with respect to how likely they are to contain a bug. This process reduces the search space of source files and helps developers to find relevant source files quicker. In this paper, we propose a multi-component bug localization approach that leverages different textual properties of bug reports and source files as well as the relations between previously fixed bug reports and a newly received one. Our approach uses information retrieval, textual matching, stack trace analysis, and multi-label classification to improve the performance of bug localization. We evaluate the performance of the proposed approach on three open source software projects (i.e., AspectJ, SWT, and ZXing) and the results show that it can rank appropriate source files for more than 52% of bugs by recommending only one source file and 78% by recommending ten files. It also improves the MRR and MAP values compared to several existing state-of-the-art bug localization approaches. 相似文献
3.
An analysis of the asynchronous behavior of the hysteresis machine is undertaken based on a “rectified” model of its structure. The hysteresis shell and the yoke of the rotor are assumed as being manufactured out of materials with finite conductivities. The field analysis undertaken via Maxwell's equations and Poynting's theorem shows the influence of the induced eddy currents on the machine performance at nonvanishing slips. The characteristics of the machine are computed as functions of slip, revealing three particularly interesting cases. 相似文献
4.
Roberto De A. Martins 《Journal of The Franklin Institute》1981,311(5):331-337
A paper by Macagno (3) in this Journal is discussed. The origin of the concept of physical dimensions is traced back to ideas previously used in analytic geometry. Descartes' use of the word “dimension” in the study of physical magnitudes is shown to have properties completely different from Fourier's dimensions, being therefore unimportant to the evolution of dimensional analysis. It is also shown that the principle of homogeneity was used in the derivation of physical equations sixty years prior to the publication of Fourier's work, and that the latter was aware of this paper, that may be considered the earliest publication on dimensional analysis. 相似文献
5.
A major concern of the governments of industrialised nations is the basis for the allocation of public resources to the private sector of industry. One particular area of debate is the role governments should play in the support and direction of high technology. This paper examines the contribution of the British government to the establishment of a computer industry and, in particular, the attempts to stimulate the industry during the period 1959 to 1962 by supporting the development and production of a ‘supercomputer’.The history of the negotiations between the three major participants, the National Research and Development Corporation, Ferranti Ltd., and Manchester University, has been reconstructed in considerable detail in order to provide the basis for an analysis of the interaction of technical, financial, organisational and political constraints in the attempts to establish the project'.The failure of NRDC to achieve its broad aims of promoting the future health of the computer industry is traced to three major problems — their failure to formulate clear objectives, their concern to maintain technical control, and inadequate policies for risk-sharing. These were exacerbated by the technical uncertainty associated with novel technology, an inadequate market analysis by Ferranti, and de facto technical direction by the university department.On this basis broad conclusions are drawn on the conditions necessary for a satisfactory return on public investment in high technology. 相似文献
6.
A set of the block pulse functions is applied to solve the Fredholm's and the Volterra's integral equations of the second kind. An algebraic equation in matrix form which is equivalent to the solution of the integral equation is developed. The approximate results are easily obtained by a few computations. An accurate solution canbe evaluated in a digital computer by solving the algebraic equation. Two examples are given. 相似文献
7.
A unified approach to stability analysis of feedback control systems with pulse-width modulators is discussed. The proposed procedure is developed on the basis of the discrete analog of Lyapunov's method, with no limiting hypothesis on the structure of the controlled plant and of the modulation law.The analysis is exemplified particularly for lead-type PWM control systems. Significant plant classes are investigated, and the critical values of parameters in a closed form are determined which assure asymptotic stability of the steady-state solution, whatever the reference input may be. 相似文献
8.
Several techniques are available for implementing a scalar digital filter using lattice and ladder structures which are known to yield low noise realizations. Of these, the lattice and ladder structures proposed by Gray and Markel have the advantage of being internally scaled. Block implementation of a scalar digital filter offers a number of advantages. In this paper, new algorithms to realize block digital filters in the form of cascaded lattice or ladder two-pairs are proposed. Block lattice and ladder structures similar to Gray and Markel's scalar structure are obtained by using Levinson recursion. Also, normalized block lattice and ladder structures are developed. 相似文献
9.
10.
The literature concerning information flow and organizational design for technological innovation is summarized and a conceptual framework of the process of organized technological innovation within the firm is developed. The framework incorporates Rosenbloom's premise that corporate strategy can serve to cut across both internal and external boundaries of the firm and is shown to be consistent with the relevant organizational and planning literatures. The potential for using mathematical models to represent a firm's corporate strategy, budgeting and resource allocation activities is discussed. We argue that such models are needed to provide for policy analysis and could lead to a simulation capability that serves as a surrogate for real-life experimentation. 相似文献
11.
Ravi Kathuria Narinder Nath Kathuria Abhishek Kathuria 《The Journal of High Technology Management Research》2018,29(2):227-236
To refine the theories of operations strategy, we need research from all different situational contexts, including different countries—both developing and developed. There have been many studies, including some replications, done in various parts of the world to further the debate on whether competitive priorities are mutually supportive or if they present potential trade-offs, but hardly any from a rapidly growing economy, such as India. This study is a significant attempt in that direction. After a thorough review of the literature, a set of hypotheses is introduced to test whether Indian manufacturers view competitive priorities as mutually supportive or trade-offs. The data from over 150 high-ranking individuals from over 75 manufacturers in India is used to test the hypotheses by way of cluster analysis and ANOVA. The resultant taxonomy reveals patterns that uniquely represent Indian manufacturers' view of the competitive priorities, namely quality, flexibility, delivery and price. The study findings have significant managerial implications, both for India and other developing as well as developed economies. The taxonomy will serve to gauge India's manufacturers' role in the world. From a researcher's perspective, this study makes a significant contribution to theory development, furthers our understanding of the strategic role of operations, moves forward the ongoing debate on the topic of trade-offs or complementarity, and paves the way for future studies in this topical area. 相似文献
12.
A unified variational approach to network analysis is presented. From an initial classification of variables, expressed in topological terms, Lagrangian energy functions are generated which may be used in Hamilton's principles. This topological formalism allows extension into nonconservative networks and enables the complete retention of classical formalism in all networks.By using a topological version of the Brayton-Moser mixed potential function, several power variational principles are developed. These principles lead to comparison of the roles played by classical energy and power state functions in analytical mechanics. 相似文献
13.
The advent of weather radar making it possible to make almost instantaneous measurements of precipitation over a considerable area opens up very important new prospects for meteorological forecasting. Under the aegis of the European Community, the world's first international weather radar system is being planned, primarily to serve the needs of western Europe. It is expected, however, that techniques and equipment developed by European industry will be widely adopted elsewhere. 相似文献
14.
In this paper, we derive discrete versions of Green's identities (which appear in the study of potential field theory) as direct consequences of applying Tellegen's Theorem to the Graph—Theoretic Field Model (GTFM) of a field. The procedure herein is in marked contrast to the existing procedures where Green's Identities are derived from the Divergence Theorem by using some strictly mathematical operations. In particular, Green's third identity, which is the starting point formulation for the Boundary Integral Method, is singled out for special attention in terms of its discrete counterpart in the Graph—Theoretic Field Model. The first discrete identity is used to establish certain properties of solutions for the GTFM and a limiting process is applied to the three discrete identities to derive the traditional vector-calculus forms of Green's identities. 相似文献
15.
The analysis of the asynchronous behavior of the hysteresis machine is undertaken based on a model describing its cylindrical structure. Assuming that the hysteresis shell of the rotor is manufactured out of materials with finite conductivities, the influence of the induced eddy- currents on the machine performance is pointed out via Maxwell's equations and Poynting's theorem. The characteristics of the machine are computed as functions of slip and three interesting limiting cases are revealed. 相似文献
16.
Tuvia Blumenthal 《Research Policy》1978,7(1):63-87
This paper deals with several aspects of R & D activity in Israel's manufacturing industries on three levels — the economy, industrial branch and the firm. Relative to other industrial countries, Israel is characterized by a high share of R & D expenditure in GNP but a low level of industrial R & D. If we take registered patents as an indicator of R & D output no significant correlation is found between this measure and expenditure on R & D; this may point to a low level of success or to the nature of R & D being directed more to small improvements of existing products and processes than to new inventions. An inter-industry analysis shows that R & D expenditure is positively correlated with average firm size and capital per employee and negatively correlated with concentration ratio. A positive correlation was also found with respect to increase in sales and export per employee but not with the rate of growth of export. Although most R & D is performed by large companies there is no significant correlation between R & D expenditure and firm's size among firms engaged in R & D, nor between R & D expenditure and firm's profitability. Concerning the relationship between domestic R & D and imports of technology a tentative conclusion is that Israel does not derive sufficient benefit from the international stock of knowledge. 相似文献
17.
The article presents an analysis of the effect of granularity and order in an XML encoded collection of full text journal articles. Two-hundred and eighteen sessions of searchers performing simulated work tasks in the collection have been analysed. The results show that searchers prefer to use smaller sections of the article as their source of information. In interaction sessions during which articles are assessed, however, they are to a large degree evaluated as more important than the articles’ sections and subsections. 相似文献
18.
This paper reviews two recent research studies on Portuguese New Technology Based Firms (NTBFs). Attention is given to the role and contribution of NTBFs to innovation. The main argument is that, by and large, NTBFs are less concerned with the introduction of major innovations and more with creative adaptive improvements to products and services based upon new technologies first introduced elsewhere. The empirical research found that Portuguese NTBFs are a recent phenomenon associated with diffusion of Electronics and Information Technologies (EIT) during the late 1980s. They perform a wide variety of knowledge-intensive activities, which enhance local users' adoption processes and they are associated with different forms of technology transfer through external linkages. Overall, NTBFs undertake a frequently unobserved role as technology searchers and acquirers that, pushed by idiosyncratic local niche market opportunities, selectively choose among and enhance technologies developed elsewhere, introducing them into the local market. 相似文献
19.
A simple theory is presented for decoupling a pair of lossless coupled nonuniform transmission lines (CNUTL), with a common return and supporting TEM waves, into two lossless nonuniform transmission lines (NUTL). This theory is independent of the port terminations, symmetry conditions, etc. The method directly relates the line parameters of the lossless CNUTL's to those of the decoupled lines and vice versa; further, the matrix parameters of the CNUTL's as a four-port are explicitly expressed in terms of those of the decoupled lines as two-ports. This theory is then utilized to study the applications of CNUTL's as directional couplers.It is shown that for CNUTL's to behave as a codirectional coupler, each of the decoupled lines should be a proportional line, while for contradirectional coupler action, the two decoupled lines have to be duals of each other. The coupling response of the codirectional coupler is found to be periodic, while the phase shift between coupled and transmitted signals varies linearly with frequency. The coupling response of various contradirectional couplers with smooth transition at one of the ends, for which the decoupled lines are “basic NUTL's with hyperbolic solutions”, are studied in detail. It is shown that all these couplers have a high-pass response and that the CNUTL's with “hyperbolic cosine squared lines” as decoupled lines have the best response of all the CNUTL's considered. 相似文献
20.
M.L. Gimpl 《Research Policy》1974,3(1):124-131
New Zealand's science policy consists of spending about 0.5% of its G.N.P. on R & D. Of this expenditure 41% is spent on activities relating to agriculture and 9% on activities related to manufacturing. This imbalance in spending between agriculture and manufacturing is not consistent with the goals being placed on manufacturing and the importance of manufacturing in New Zealand's domestic economy. A change in emphasis of an expanded R & D programme coupled with new methods of technology transfer will be necessary for New Zealand to obtain her goals of economic expansion. 相似文献