A Multivariate Approach to Construction Contract Bidding Mark-up Strategies

A multivariate approach to contract bidding strategies in the construction industry is presented. This represents a radical departure from previous work in the field by using all available data on competing bidders. ‘Optimal’, ‘no loss’ and ‘break even’ mark-up strategies are derived and methods of parameter estimation proposed. A case study shows how the three strategic mark-up values are calculated against known competitors.     

A Non-linear Multi-criteria Programming Approach for Determining County Emergency Medical Service Ambulance Allocations

In this paper an integer, non-linear mathematical programming model is developed to allocate emergency medical service (EMS) ambulances to sectors within a county in order to meet a government-mandated response-time criterion. However, in addition to the response-time criterion, the model also reflects criteria for budget and work-load, and, since ambulance response is best described within the context of a queueing system, several of the model system constraints are based on queueing formulations adapted to a mathematical programming format. The model is developed and demonstrated within the context of an example of a county encompassing rural, urban and mixed sectors which exhibit different demand and geographic characteristics. The example model is solved using an integer, non-linear goal-programming technique. The solution results provide ambulance allocations to sectors within the county, the probability of an ambulance exceeding a prespecified response time, and the utilization factor for ambulances per sector.     

基于记分函数的语言型多准则决策方法

分析了语言指标的特点,提出语言指标与Vague值转换的基本思路,给出语言指标与典型Vague值的转换方法.该方法能够保持决策者风险偏好的一致性.证明了在各方案属性的语言指标转化为Vague值后,即使采用不同风险偏好的记分函数,也能得到相同的记分值范围,据此提出基于记分函数的语言型多准则决策方法.通过实例说明该方法能减少决策者的风险偏好对决策结果的影响,提高决策的客观性和准确性.     

Strategies for Backward-area Development: A Systems Approach

India has a number of backward regions, and economic development of these regions requires special strategies. Development problems are multi-disciplinary and complex, and are ideally suited to a systems approach. The present paper outlines a methodology of such an approach, and discusses its application in relation to two backward districts in India.     

Adapting Multi-criteria Planning to the Nigerian Economy

Techniques of development planning involve physical and financial aspects. Financial planning refers to the allocation of monetary resources; in Nigeria the previous development plans and budgets, which had been based on the incremental approach, contained various shortcomings, resulting in the deliberate inflation of estimated expenditure, and consequently it has been associated with retarded growth and conflicts between ministries. In addition, the approach does not adequately relate national objectives to their priorities. Conventional mathematical programming models are unable to allocate resources effectively in a conflicting environment. This paper proposes a goal programming model for allocating a country's scarce resources among competing sectors during a planned period. The goal programming model is shown to be adequate for allocating resources under the conflicting conditions of national planning. The model can help to determine all the priorities for the goals.     

基于模糊证据推理及改进TOPSIS的多属性群决策方法

针对不同识别框架多属性群决策问题属性准则度量的不确定性、随机性,定义基于梯形模糊数表征的属性准则评价等级相似度量,求解专家决策权重的最优解。对公共识别框架备选方案属性准则采用模糊证据推理过程综合专家评价等级置信度信息;利用可严格区分属性准则评价等级的相似度量,改进TOPSIS方法中备选方案属性准则评价等级置信度距离因子,获取备选方案逼近正负理想解的贴近度。实例分析以某通信企业电信产品市场竞争力评估为例,说明基于模糊证据推理、改进TOPSIS的多属性群决策问题求解过程,从属性准则专家模糊评价等级置信度集中获取直观的待评估产品市场竞争力排序结果,验证该方法解决此类决策问题的可行性与有效性。     

基于前景云的不确定语言多准则国际股指投资群决策

针对投资决策过程中语言评价值具有随机性及模糊性,以及投资者的决策容易受到其情绪的影响且不同投资者受到的影响程度不同,本文提出基于前景云的不确定语言多准则投资群决策方法,并将其运用在国际股指投资中。其中,前景理论模型用来刻画投资者情绪对决策的影响,而云模型用来刻画语言评价值模糊性和随机性之间的关联。更具体来说,论文首先解决传统文献云生成方法中云期望值超过论域或者无法区分语言评价标度等级等问题,然后构建了前景云模型并将该模型应用于多个专家共同进行的国际股指投资群决策。实证结果显示,该模型得出的决策结果比传统决策方法下的结果更直观、可靠,表现为决策依据不仅考虑方案的期望值大小及变动风险,而且还考虑了投资者情绪对决策的影响。由此可得出,本文所提出的模型更符合现实情景,也更能有效实现对投资群决策。     

A Categorical Approach to Linkage

Linkage of ideals is a very well-studied topic in algebra. It has lead to the development of module linkage which looks to extend the ideas and results of the former. Although linkage has been used extensively to find many interesting and impactful results, it has only been extended to schemes and modules. This paper builds a framework in which to perform linkage from a categorical perspective. This allows a generalization of many theories of linkage including complete intersection ideal linkage, Gorenstein ideal linkage, linkage of schemes and module linkage. Moreover, this construction brings together many different robust fields of homological algebra including linkage, homological dimensions, and duality. After defining linkage and showing results concerning linkage directly, we explore the connection between linkage, homological dimensions, and duality. Applications of this new framework are sprinkled throughout the paper investigating topics including module linkage, horizontal linkage, module theoretic invariants, and Auslander and Bass classes.

     

L-拓扑空间中的半拟紧性

在L-拓扑空间中借助于半拟开L-集合和它们的不等式给出了半拟紧性的一个新定义,这里L是完备的DeMorgan代数。它也能够借助于半拟闭L-集和它们的不等式刻画。当L是完全分配的DeMorgan代数时,它的许多刻画被给出了。     

A Systems Approach to Management

A procedure is outlined for deciding the mix of price and variable non-price features, such as quality, delivery, service or financing, to be included in a bid. The level of each non-price feature is set independently by comparing incremental spending against the alternative price reduction and basing the choice on value to the faction in the customer organization expected to dominate in the choice of the successful bid. Divergence from competition on all non-price features, both fixed and variable, is then taken into account in setting price by calculating a net price equivalent of feature differences as against each competitor. For any given markup the probability of success against a competitor over whom there is a net advantage is the same as that for an equivalently lower markup were price to be the sole basis for allocating the order.     

A Semigroup Approach to Automaticity

We present an abstract, yet rather natural concept of automaticity which is based on semigroup actions. The standard notion of k-automaticity as well as many, if not all of its generalizations are recovered by specifying appropriate semigroup actions on $ \mathbb{N}_0 $ or $ \mathbb{N}^N_0 $ or other similar objects—e.g., the standard notion of k-automaticity is recovered by considering a certain "natural" action of the free semigroup with k generators on $ \mathbb{N}_0 $. We show that the main results characterizing automatic sequences (Cobham, 1972, Math. Systems Theory 6) hold almost verbatim in the general context, too.AMS Subject Classification: 11B85, 68Q45, 16W22, 18DXX.     

A New Approach to Arcs

Some properties of arcs in PG(2,q) are discussed via its cyclic model. A covering number of a set of points in PG(2,q) is the smallest number of lines needed to cover the set -, where the set of points of PG(2,q) is identified with Z . It is proved that the covering number of a conic is either 1 or greater than q/4. Hyperovals with covering number 2 are characterized for q even. Also, a possible method for constructing nonclassical hyperovals having small covering numbers is given.     

A Bayesian Approach to Short-term Forecasting

A new approach to short-term forecasting is described, based on Bayesian principles. The performance of conventional systems is often upset by the occurrence of changes in trend and slope, or transients. In this approach events of this nature are modelled explicitly, and successive data points are used to calculate the posterior probabilities of such events at each instant of time.The system produces not only single-figure forecasts but distributions of trend and slope values which are relevant to subsequent decisions based on forecasts.     

A Metric Approach to Elastic Reformations

We study a variational framework to compare shapes, modeled as Radon measures on \({\mathbb{R}}^{N}\) , in order to quantify how they differ from isometric copies. To this purpose we discuss some notions of weak deformations termed reformations as well as integral functionals having some kind of isometries as minimizers. The approach pursued is based on the notion of pointwise Lipschitz constant leading to a matric space framework. In particular, to compare general shapes, we study this reformation problem by using the notion of transport plan and Wasserstein distances as in optimal mass transportation theory.     

A Half-Space Approach to Order Dimension

The aim of the present paper is to investigate the half-spaces in the convexity structure of all quasiorders on a given set and to use them in an alternative approach to classical order dimension. The main result states that linear orders can almost always be replaced by half-space quasiorders in the definition of the dimension of a partially ordered set. The work of the first named author was partially supported by the European Community’s Marie Curie Program (contract MTKD-CT-2004-003006). The second named author’s work was supported by OTKA of Hungary No. T043034.     

A Semigroup Approach to Harmonic Maps

We present a semigroup approach to harmonic maps between metric spaces. Our basic assumption on the target space (N,d) is that it admits a barycenter contraction, i.e. a contracting map which assigns to each probability measure q on N a point b(q) in N. This includes all metric spaces with globally nonpositive curvature in the sense of Alexandrov as well as all metric spaces with globally nonpositive curvature in the sense of Busemann. It also includes all Banach spaces.The analytic input comes from the domain space (M,) where we assume that we are given a Markov semigroup (p_t)_t>0. Typical examples come from elliptic or parabolic second-order operators on Rⁿ, from Lévy type operators, from Laplacians on manifolds or on metric measure spaces and from convolution operators on groups. In contrast to the work of Korevaar and Schoen (1993, 1997), Jost (1994, 1997), Eells and Fuglede (2001) our semigroups are not required to be symmetric.The linear semigroup acting, e.g., on the space of bounded measurable functions u:MR gives rise to a nonlinear semigroup (P_t^*)_t acting on certain classes of measurable maps f:MN. We will show that contraction and smoothing properties of the linear semigroup (p_t)_t can be extended to the nonlinear semigroup (P_t^*)_t, for instance, L_p–L_q smoothing, hypercontractivity, and exponentially fast convergence to equilibrium. Among others, we state existence and uniqueness of the solution to the Dirichlet problem for harmonic maps between metric spaces. Moreover, for this solution we prove Lipschitz continuity in the interior and Hölder continuity at the boundary.Our approach also yields a new interpretation of curvature assumptions which are usually required to deduce regularity results for the harmonic map flow: lower Ricci curvature bounds on the domain space are equivalent to estimates of the L₁-Wasserstein distance between the distribution of two Brownian motions in terms of the distance of their starting points; nonpositive sectional curvature on the target space is equivalent to the fact that the L₁-Wasserstein distance of two distributions always dominates the distance of their barycenters.Dedicated to the memory of Professor Dr. Heinz Bauer     

A Language-Action Approach to Operational Research

This paper results from a collaboration between two academics, one a social psychologist who has explored creative work in engineering product design, the other engaged in the application of ‘soft’ methods in OR, but with a background in engineering. Much of the new thinking in OR is described in terms of a language-action perspective which is prominent in studies of computer supported work, negotiation, and other forms of discursive action. The perspective is used to examine some of the tasks needing to be undertaken if OR is to shift from a concern with social engineering to a concern with reflective social action. Particular attention is paid to the analysis of dilemmas, the growth of commitment, and the assessment of methods. It is concluded that, if OR makes the analysis of cognitive and political processes part of the core of the subject, it may become an epistemic subject with wide application to organisational decision-making.     

A New Approach to Stochastic Optimization

We derive general explicit solutions to the investment model without reliance on the existing duality or variational methods.