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1.
Tol RS 《Scientometrics》2012,90(3):763-780
Performance measures of individual scholars tend to ignore the context. I introduce contextualised metrics: cardinal and ordinal pseudo-Shapley values that measure a scholar’s contribution to (perhaps power over) her own school and her market value to other schools should she change job. I illustrate the proposed measures with business scholars and business schools in Ireland. Although conceptually superior, the power indicators imply a ranking of scholars within a school that is identical to the corresponding conventional performance measures. The market value indicators imply an identical ranking within schools and a very similar ranking between schools. The ordinal indices further contextualise performance measures and thus deviate further from the corresponding conventional indicators. As the ordinal measures are discontinuous by construction, a natural classification of scholars emerges. Averaged over schools, the market values offer little extra information over the corresponding production and impact measures. The ordinal power measure indicates the robustness or fragility of an institution’s place in the rank order. It is only weakly correlated with the concentration of publications and citations.  相似文献   

2.
H. Stehfest 《OR Spectrum》1981,2(4):193-206
The mathematical tools applicable in the field of river quality management are reviewed in the order in which they are used in the actual process of building and applying river quality models. The types of models and their properties are discussed, and the important problem of parameter estimation is examined. The use of the models in steady-state and real-time optimal control studies is investigated. Finally, the embedding of river quality control problems into problems of wider scope is discussed. The methodologies are illustrated by applications to the Rhine river.
Zusammenfassung Die mathematischen Methoden, die man in der Wassergüterwirtschaft anwenden kann, werden diskutiert, und zwar in der Reihenfolge, in der sie bei der aktuellen Problemlösung benutzt werden: Zunächst werden die Typen mathematischer Gewässergütemodelle und ihre Eigenschaften erörtert, danach wird auf das Problem der Parameterschätzung eingegangen. Dann wird die Benutzung der Gütemodelle zur Lösung von Problemen der optimalen Steuerung erläutert, wobei unterschieden wird zwischen stationären und instationären Problemen. Abschließend wird diskutiert, wie die klar definierten Probleme der optimalen Steuerung in den weiteren Kontext der Wassergütewirtschaft einzubetten sind. Die verschiedenen Methoden werden illustriert durch Anwendungsbeispiele, die sich alle auf den Rhein beziehen.


Revised version of a paper read at the Annual Meeting of the Deutsche Gesellschaft für Operations Research, Regensburg, Germany, September 19–21, 1979  相似文献   

3.
Over the last decade, there has been a rapid growth of the use of genetic algorithms in the various areas of production and operations management. This paper provides a review of genetic algorithms research published in twenty-one major production and operations management journals from 1990–2001. More specifically, it identifies research trends and publication outlets of genetic algorithms applications. Our findings show that there are only a handful of production and operations management areas to which genetic algorithms have been applied as the solution approach. Furthermore, we recognize and discuss potential research areas and outlets in which researchers may target their work as well as the need for top ranked POM journals to consider publishing genetic algorithms related papers.  相似文献   

4.
Using altmetrics for assessing research impact in the humanities   总被引:2,自引:0,他引:2  
The prospects of altmetrics are especially encouraging for research fields in the humanities that currently are difficult to study using established bibliometric methods. Yet, little is known about the altmetric impact of research fields in the humanities. Consequently, this paper analyses the altmetric coverage and impact of humanities-oriented articles and books published by Swedish universities during 2012. Some of the most common altmetric sources are examined using a sample of 310 journal articles and 54 books. Mendeley has the highest coverage of journal articles (61 %) followed by Twitter (21 %) while very few of the publications are mentioned in blogs or on Facebook. Books, on the other hand, are quite often tweeted while both Mendeley’s and the novel data source Library Thing’s coverage is low. Many of the problems of applying bibliometrics to the humanities are also relevant for altmetric approaches; the importance of non-journal publications, the reliance on print as well the limited coverage of non-English language publications. However, the continuing development and diversification of methods suggests that altmetrics could evolve into a valuable tool for assessing research in the humanities.  相似文献   

5.
An integrated approach to the problem of allocation of inspection effort in multistage production systems is presented. The problem addresses multiple inspection operations, different disposition policies and inspection, production and repair errors. Quality and cost transfer functions are developed to model production operations and different types of inspection operations in a unified manner and to facilitate the recursive computations required to evaluate alternative system configurations. We formulate the combined inspection location and sequencing problem as a nonlinear mathematical programming problem and solve it with a branch and bound technique, using a heuristic to generate a feasible solution and upper bound. These developments are illustrated with a numerical example.  相似文献   

6.
This paper proposes a conceptual design tool, based upon inferential design theory. It has been specifically developed for the design of production and operations systems, but its use can be extended to other engineering areas, such as mechanical and structural systems. Inferential design theory and its foundation in the inferential theory of learning are briefly outlined. Both theories are based on the idea of using specialised knowledge operators in learning and design, termed knowledge transmutations and design knowledge transmutations respectively. The 24 transmutations existing in the two theories are outlined, and a further 12 design-specific transmutations are proposed. These have been developed as a result of our research. A conceptual design process is proposed, in which design knowledge transmutations are used. A software tool for design, CREDO, is also described and an example of its use in the generation of design concepts for an after-sales service facility is presented. The conclusions discuss the initial methodological experience of using CREDO to generate design concepts. They are based on the introductory use of CREDO at Technion in Israel for teaching purposes. Directions for further research are also provided.  相似文献   

7.
We study a joint admission/inventory control problem for a manufacturing system producing one product to meet random demand. The system employs a constant work- in-process policy (CONWIP) whereby the total inventory of raw material and finished items is kept constant, and accepts orders only as long as the backlog is below a certain level. The objective is to determine the CONWIP and backlog levels that maximize the mean profit rate of the system. The system is modelled as a single server with a finite queue. It turns out that the mean profit rate is either concave or decreasing in one control parameter and also decreasing for large values of the other control parameter. A simple algorithm is developed which tracks down the globally optimum design in finite time. Numerical results show that the joint admission/inventory control policy achieves higher profit than other production control policies that have been examined in the literature.  相似文献   

8.
Operations managers and scholars in their search for fast and good solutions to real-world problems have applied genetic algorithms to many problems. While genetic algorithms are promising tools for problem solving, future research will benefit from a review of the problems that have been solved and the designs of the genetic algorithms used to solve them. This paper provides a review of the use of genetic algorithms to solve operations problems. Reviewed papers are classified according to the problems they solve. The basic design of each genetic algorithm is described, the shortcomings of the current research are discussed and directions for future research are suggested.  相似文献   

9.
Expert systems are rapidly growing in diversity of application and usage worldwide. Even though expert system development has been slow in applying expert systems to the specific field of structures, expert system technology has been pervasive in other areas of engineering and manufacturing. This paper provides a short introduction on expert systems, looking at their development, application and future trends.  相似文献   

10.
陈念慈 《中国标准化》2000,(5):46-46,48
一、问题的提出我公司是一个有 6 0年历史的老厂 ,解放后质量管理工作经历了三个阶段 :一是层层把关和单纯的产品符合性检验阶段 ,主要是按照原苏联提供的一套企业管理模式进行组织和控制产品质量 ;二是以预防为主的统计质量控制阶段 ;三是以不断改进为目的的全面质量管理 (简称TQM )阶段。通过上述三个阶段 ,从管理机构和管理方式上逐步形成一个包括质量立法、质量控制、质量检验、质量监督的质量保证体系。但与ISO 90 0 2∶1994国际标准相对照 ,感到原先的质量管理模式仍存在许多需要解决的矛盾和问题。质量管理职责细则涉及面较窄 …  相似文献   

11.
12.
An expert system can be denned as ‘a tool which has the capability to understand problem specific knowledge and use the domain knowledge intelligently to suggest alternate paths of action’. This paper presents a structured framework for the development of an expert system. The five major aspects of expert system development are: Problem definition; knowledge acquisition, representation and coordination; inference mechanism; implementation; and learning. These aspects are illustrated through the help pf a modular robot configuration prototype expert system. Several industrial engineering applications in the areas of process planning, facilities planning, and maintenance and fault diagnosis are discussed and a comparative analysis of the different systems is presented.  相似文献   

13.
It is not unusual to observe that actual schedule and quality performances are different from planned performances (e.g., schedule delay and rework) during a construction project. Such differences often result in production pressure (e.g., being pressed to work faster). Previous studies demonstrated that such production pressure negatively affects safety performance. However, the process by which production pressure influences safety performance, and to what extent, has not been fully investigated. As a result, the impact of production pressure has not been incorporated much into safety management in practice. In an effort to address this issue, this paper examines how production pressure relates to safety performance over time by identifying their feedback processes. A conceptual causal loop diagram is created to identify the relationship between schedule and quality performances (e.g., schedule delays and rework) and the components related to a safety program (e.g., workers’ perceptions of safety, safety training, safety supervision, and crew size). A case study is then experimentally undertaken to investigate this relationship with accident occurrence with the use of data collected from a construction site; the case study is used to build a System Dynamics (SD) model. The SD model, then, is validated through inequality statistics analysis. Sensitivity analysis and statistical screening techniques further permit an evaluation of the impact of the managerial components on accident occurrence. The results of the case study indicate that schedule delays and rework are the critical factors affecting accident occurrence for the monitored project.  相似文献   

14.
Issues and future directions in subsecond thermophysics research   总被引:1,自引:0,他引:1  
The key issues and anticipated future directions in subsecond thermophysics research are presented and discussed. The main emphasis is placed on experimental techniques for measurements of selected thermophysical properties utilizing rapid volume heating (resistive self-heating) and rapid surface heating (laser pulse-heating) methods. The time regime covered is from 1 to 10–12s. Specific research topics and key research areas are identified and discussed.Paper based on the Panel Discussion at the First Workshop on Subsecond Thermophysics, June 20–21, 1988, Gaithersburg, Maryland, U.S.A.Formerly National Bureau of Standards  相似文献   

15.
Mastering system availability all along the system life cycle is now a critical issue with regards to systems engineering. It is more true for military systems which operate in a battle context. Indeed as they must act in a hostile environment, they can become unavailable due to failures of or damage to the system. In both cases, system regeneration is required to restore its availability. Many approaches based on system modelling have been developed to assess availability. However, very few of them take battlefield damage into account and relevant methods for the model development are missing. In this paper, a modelling method for architecture of weapon system of systems that supports regeneration engineering is proposed. On the one hand, this method relies on a unified failure/damage approach to extend acknowledged availability models. It allows to integrate failures, damages, as well as the possibility of regeneration, into operational availability assessment. Architectures are modelled as a set of operational functions, supported by components that belong to platform (system). Modelling atoms (i.e. elementary units of modelling) for both the architecture components and functions are defined, based on state-space formalism. Monte Carlo method is used to estimate availability through simulation. Availability of the architecture is defined on the basis of the possible states of the required functions for a mission. The states of a function directly depend on the state of the corresponding components (i.e. the components that support the function). Aggregation rules define the state of the function knowing the states of each component. Aggregation is defined by means of combinatorial equations of the component states. The modelling approach is supported by means of stochastic activity network for the models simulation. Results are analysed in terms of graphs of availability for mission's days. Thus, given the simulation results, it is possible to plan combat missions based on criteria such as the number of platforms to be involved given functions required for the mission or the mean of regeneration to be deployed given the possible threats. Further, the simulation will help towards the design of improved architecture of system of systems which could focus on the factors affecting the availability.  相似文献   

16.
The formation of machine-part families is an important task in the design of cellular manufacturing systems. Manufacturing cell grouping has the effect of reducing material handing cost and work in process. Among the many methods utilized in machine cells formation, the similarity coefficient method is most widely used. Production sequence and product volumes, if incorporated properly in determining the machine cells, can enhance the quality of solutions and reduce the number of intercellular movements. Measures for cell formation based on operations sequence utilizing ordinal production data are few and have many limitations, such as counting the number of the trips for each individual part instead of counting the weights of the batches. A new ordinal production data similarity coefficient based on the sequence of operations and the batch size of the parts is introduced. Furthermore, a new clustering algorithm for machine cell formation is proposed. The new similarity measure showed more sensitivity to the intercellular movements and the clustering algorithm showed better machine grouping.  相似文献   

17.
The workforce ageing phenomenon is recently affecting most of the Organisation for Economic Co-operation and Development (OECD) member countries, due to a general ageing of their populations and a higher average retirement age of the workforce. In this paper, the topic of ageing workforce management is addressed from a production research standpoint, with the aim of understanding how older workers can be supported and involved in a manufacturing system. First, the current state of the art related to the ageing workforce in production systems is presented. This is structured according to four main topics: (1) analysis and evaluation of ageing workers’ functional capacities, (2) consideration of ageing workers’ capacities in industrial system modelling and management, (3) analysis and exploitation of ageing workers’ expertise, (4) acknowledgement, analysis, design and integration of supporting technologies. Next, the discussion on the impact of the ageing workforce on manufacturing systems’ performances leads to the comparison of some technological advances that are related to the Industry 4.0 paradigms. Finally, a future research agenda on this topic is proposed, based on the same topics classification proposed for the literature analysis. Five different research areas are derived, suggesting future directions for appropriate research concerning the employ of older workers in production environments.  相似文献   

18.
The theory of constraints (TOC) has recently gained much success in its application to industrial and service organizations. This paper applies the TOC principles to the management of information technology (IT) in the organization. The paper creates a four tiered model for the application of the TOC to IT, starting with TOC's throughput-driven business policy; on with the seven step resource management methodology; through the cost/utilization capital investment technique; and concluding with the drum-buffer-rope production activity procedure. We draw a framework and a methodology showing how IT can be more effective using the TOC way of management. In order to systematically explore the location of the organization's constraints we adapt to the TOC a synthesis of three established management frameworks: stakeholder analysis, the value chain and Boston Consulting Group's portfolio analysis model  相似文献   

19.
This research uses simulation technique to compare the output performance of pull production systems with different inter-station storage capacities (ISSC) under various levels of total inventory (INV) in the system, station coefficient of variation (CV), and station down-time (DT). There are two primary findings from this study. First, it shows pull systems with larger ISSC yield a significantly higher output at all levels of INV in the system, station CV, and station DT. Second, it shows that lines using a strict kanban-based pull system can increase output while decreasing WIP inventory simply by allowing the inventory to flow freely between stations. These are major findings considering that the modifications necessary in the system to achieve these results are fairly uncomplicated and should require minimal investment.  相似文献   

20.
Using mechanical sub-cooling systems to increase COP of vapor compression cycles is a known method in literature to save energy and increase efficiency. Recently, much progress has been made with respect to investigation into its different aspects that can help to put it into practice. Numerical and experimental works are considered for the purpose of highlighting this progress. These can be categorized as: a) simulation of performance characteristics resulting from different refrigerant combinations in dedicated mechanical sub-cooling systems, b) variation in performance characteristics for a vapor compression cycle using integrated mechanical sub-cooling because of fouling, c) experimental study about consequences of employing a dedicated mechanical subcooling cycle with a simple vapor compression system, and d) experimental investigation about consequences of employing a subcooler in a two-stage refrigeration cycle. Some important results are discussed. Finally, some suggestions are made to provide direction into future research in this area to help put it into practice.  相似文献   

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