首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Many of the arguments that are found in the literature on the theme "O.R./M.S. in crisis" stem not just from alternative definitions of O.R./M.S., but from differences in strongly held views about its scope and role in organisations, and these are then reflected in the vehemence with which certain definitions are defended or criticised. It is when the hopes and aspirations of O.R./M.S. are compared with what is being achieved in practice, that we realise the degree to which O.R./M.S. has failed to live up to its original promise. In most organisations, O.R. analysts are expected and are happy to act as technicians and not as advisers, so that technique orientation and concern with tactical problems are constantly reinforced. In addition, managers in various functions have become aware of the potential contribution of analytical modelling in their own spheres and have begun to recruit analysts direct, resulting in the possible fragmentation of O.R. and the loss of its unique identity. The responsibilities of O.R./M.S. obviously relate not only to its organisational status, but also to an examination of and an identification with organisational goals. Many O.R. analysts are plainly more comfortable when these goals are clearly defined for them, an attitude which people from other professions will readily endorse, but if O.R./M.S. has any aspirations to get involved in strategic problems, it will have to pose questions about the validity and appropriateness of organisational goals and try to influence the formulation of problems accordingly.  相似文献   

2.
A decision situation and model-specific O.R. method developed for reliability analysis of an Arctic liquid natural gas facility is outlined. It was developed by modifying a decision situation and model-specific O.R. method developed earlier for time (schedule or programme) risk analysis of offshore North Sea projects. The role and value of such methods is discussed in relation to general O.R. methods and specific techniques like C.P.M./PERT.  相似文献   

3.
An on-going cooperative linkage scheme between the University of Nigeria, Nsukka and Trinity College Dublin is described. The broad objective of the scheme is to develop M.S./O.R. at Nsukka. The scheme focuses on a research study of methods of processing, storing and marketing yams and cassava at farm and village level in Nigeria.  相似文献   

4.
To enhance the research and application of mathematical programming and any other O.R. methodologies, it is desirable to investigate some ‘general’ models. This is particulary important in the development of decision support systems, where models play a significant role in management support. This study examines several applications of the maximal covering location planning (M.C.L.P.) model. They include data abstraction, statistical classification, cognitive process modelling, etc. In addition to demonstrating the wide applicability of the model, we also address some implementation issues associated with the applications of the M.C.L.P. model.  相似文献   

5.
The aim of this paper is to argue that O.R. should get more involved in a systems approach to support the processes of decision making within organizations. To do this effectively, more research is needed, and some suggestions are made to shift the emphasis of research within the O.R. community. The shift should occur both at the fundamental level of major research efforts and in the styles of project sought within M.Sc. courses. If the practice of systems O.R. is to develop, then it is time that a theoretical basis is developed.  相似文献   

6.
Supervised classification is an important part of corporate data mining to support decision making in customer-centric planning tasks. The paper proposes a hierarchical reference model for support vector machine based classification within this discipline. The approach balances the conflicting goals of transparent yet accurate models and compares favourably to alternative classifiers in a large-scale empirical evaluation in real-world customer relationship management applications. Recent advances in support vector machine oriented research are incorporated to approach feature, instance and model selection in a unified framework.  相似文献   

7.
卢博 《数学季刊》2012,(1):128-132
Let R be a noetherian ring and S an excellent extension of R.cid(M) denotes the copure injective dimension of M and cfd(M) denotes the copure flat dimension of M.We prove that if M S is a right S-module then cid(M S)=cid(M R) and if S M is a left S-module then cfd(S M)=cfd(R M).Moreover,cid-D(S)=cid-D(R) and cfd-D(S)=cfdD(R).  相似文献   

8.
This paper presents a comprehensive review of 196 studies which employ operational research (O.R.) and artificial intelligence (A.I.) techniques in the assessment of bank performance. Several key issues in the literature are highlighted. The paper also points to a number of directions for future research. We first discuss numerous applications of data envelopment analysis which is the most widely applied O.R. technique in the field. Then we discuss applications of other techniques such as neural networks, support vector machines, and multicriteria decision aid that have also been used in recent years, in bank failure prediction studies and the assessment of bank creditworthiness and underperformance.  相似文献   

9.
方洪锦 《数学杂志》1994,14(3):335-338
在这篇文章里,我们证明了,当环S是R的excellent扩张,M是S-模时,M做为S-模的弱维数与M做为R-模的弱维数相等。  相似文献   

10.
This article discusses mathematics education research in relation to equity and current U.S. reforms. Although mathematics education researchers and reformers give attention to equity, work in this area tends to ignore relevant social and cultural issues. I begin by surveying articles on equity published in recent, mainstream education journals, highlighting the lack of attention given to social class and ethnicity. I discuss the implications of this limited research base. Specifically, I argue that current mathematics education reforms have been shaped by good intentions and existing research, neither of which offers adequate guidance to address the complexities of equity in mathematics classrooms today. Drawing from a study of social class differences in students' experiences in one reform-oriented classroom, I discuss the challenges and dilemmas inherent in sociocultural approaches to research in mathematics education and their potential contributions. I call for research from a sociocultural perspective, focusing on ways in which students from underrepresented groups can struggle when encountering particular instructional approaches, and ways in which teachers and students are able to address such struggles.  相似文献   

11.
This article discusses mathematics education research in relation to equity and current U.S. reforms. Although mathematics education researchers and reformers give attention to equity, work in this area tends to ignore relevant social and cultural issues. I begin by surveying articles on equity published in recent, mainstream education journals, highlighting the lack of attention given to social class and ethnicity. I discuss the implications of this limited research base. Specifically, I argue that current mathematics education reforms have been shaped by good intentions and existing research, neither of which offers adequate guidance to address the complexities of equity in mathematics classrooms today. Drawing from a study of social class differences in students' experiences in one reform-oriented classroom, I discuss the challenges and dilemmas inherent in sociocultural approaches to research in mathematics education and their potential contributions. I call for research from a sociocultural perspective, focusing on ways in which students from underrepresented groups can struggle when encountering particular instructional approaches, and ways in which teachers and students are able to address such struggles.  相似文献   

12.
13.
吳文俊 《数学学报》1955,5(3):401-410
<正> 本文是這系列著作中Ⅱ的一個補充.在Ⅱ中(參閱Ⅱ的更正)我們證明了可微分閉流形的某些示性類特別是法3示性類的拓撲不變性.它的證明是隱合的(implicit).本文目的在進一步求得這些示性類用流形同調構造來表示的顧谿(explicit)公式,使我們能就任意可定向的可微分閉流形的這些示性類進行具體的計算.特別可以獲得下述結果:  相似文献   

14.
This paper investigates and discusses the use of systemic methodologies (SMs) developed in management science/operational research (MS/OR), in particular, those SM that have been informing the complexity inherent in environmental management and sustainable (EM/S) practices. By surveying a sample of the top MS/OR and systems journals, we assess the extent to which systemic management science methodologies developed recently have been used in tackling EM/S problems. Titles and abstracts of EM/S applications published in MS/OR and systems journals between 1989 and 2009 were queried for the occurrence of typical keywords associated with a set of SMs (eg, complexity theory, systems dynamics, soft systems, critical systems, viable systems model). The survey identifies a set of articles representing the practice of either a particular methodology or of a mixture of various SMs in EM/S setting. By assembling and critically reviewing a sample of applications in EM/S the paper hopes to raise awareness among environmentalists, operational researchers and management scientists of the benefits of using systemic approaches developed in MS/OR and, in this way, to encourage further exchange and conversation between these fields of management.  相似文献   

15.
The exploitation in personal computers of the well-publicized micro-technology is seen by the author as a major development with significant implications for O.R. This paper considers the nature of the implications from the point of view of the central O.R. unit of the British Steel Corporation and discusses that unit's response. The personal computer options are discussed and the applications policy which has been evolved for the author's department explained.  相似文献   

16.
Summary Let M be a compact orientable Riemannian manifold of dimension even. We assume that the manifold can carry a metric, which is positively k-pinked. In the present paper some properties of the second cohomology group of such a manifold are obtained, when the number k is greater than a number which depends on the dimension of the manifold. These properties have some applications on the topological product of some special manifolds. This research was supported by S. F. B. grant. Entrata in Redazione il 6 dicembre 1969.  相似文献   

17.
The operational research/management science journals contain an extensive literature that addresses the corporate cash management problem; yet few, if any, companies make use of any of this published work in their daily cash-management decision making. A review of the literature suggests that the reason for this lack of applications may well be poor problem formulation—the problems that are solved in the literature as ‘cash management’ problems evolve from a ‘hard systems’ view of real-world cash management. However, the problem as perceived by cash managers involves both dynamic and loosely structured components which are difficult to model using classical (i.e. ‘hard systems’) approaches.We therefore decided to approach the cash management problem as an experiment in the use of a novel visual interactive problem solving (VIPS) methodology. The aim of the experiment was to develop an implementable, visual interactive model to support daily cash management decision making. Working closely with a corporate cash manager, we first developed a visual model of his daily decision problem and then agreed on the feasible options and the interactive requirements. At this stage, the problem was sufficiently well defined for a mathematical model to be built and the visual model made ‘smart’.This paper discusses the results of this experiment and suggests that VIPS may have distinct advantages as a problem-solving technique in loosely structured, ‘messy’ problem situations.  相似文献   

18.
给出了n-FP-内射模的定义,M为左R-模,如果对任意的左R-模N有Ext1(N,M)=0,则称M为n-FP-内射模,作为应用,给出了n-FP-内射模的一些等价条件.  相似文献   

19.
谭玉明 《大学数学》2007,23(2):65-68
定出了局部环上正交群中一类子群的扩群,得到了如下结果:设R是局部环,M是R的唯一极大理想,O(2m,R)为R上正交群.对R的任意理想S,G(2m,S)表示子群{A BC D∈O(2m,R)|B∈Sm×m}.如果char(R)≠2,m≥3,G(2m,0)≤X≤G(2m,M),那么存在R的理想S,使得X=G(2m,S).  相似文献   

20.
This paper presents an exploratory account of how Operational Research/Management Science (OR/MS) practitioners understand their role in supporting an organisational strategy process. The role of strategy support is characterised by five dimensions: the activities supported within the strategy process; the nature of support provided; the orientation of the support provided; the tools used in providing support; and the nature of the relationship between consultant and client. The research draws on case studies of four OR/MS practitioners working as internal and as external consultants. The work of the practitioners is mapped onto the framework and gaps are identified. The research proposes a further dimension, namely, ‘the purpose of the support provided’, and suggests four purposeful support roles adopted by practitioners in supporting strategy within organisations: sensemaking/sensegiving; decision support tool development; problem solving/solution exploration; and process facilitation. The paper concludes with suggestions for further research.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号