Supporting acquisition decisions through effective experimental design

Weapon acquisition is a very expensive process, especially in today's cost reduction environment. Techniques must be used to conduct operational testing using a minimum of resources while not sacrificing the adequacy and credibility of the test. A coordinated use of a combat simulation and a design of experiment procedure, the Taguchi method, shows promise as an acquisition strategyThis research focused on the Javelin medium antitank system which just completed operational testing in the Fall of 1993 and was intended to give the Javelin Project Manager's office information regarding the probable outcome of critical design characteristics prior to the test. Using the Taguchi method, many different design parameters were analyzed at several different levels of performance The method reduced the number of trials required to obtain a desired level of statistical significance while still obtaining the necessary data for each parameter. Once the required number of trials were identified, the Janus combat model simulated the operational test trials.Results suggest what weapon parameters are critical to the specific measures of effectiveness of survivability, lethality, and engagement range. In a broader view, this tandem use of an experimental design technique and a combat simulation can provide acquisition managers with insights on critical system parameters prior to actual testing.     

Mechanism design for a multicommodity flow game in service network alliances

We study a collaborative multicommodity flow game where individual players own capacity on the edges of the network and share this capacity to deliver commodities. We present membership mechanisms, by adopting a rationality based approach using notions from game theory and inverse optimization, to allocate benefits among the players in such a game.     

四重整合 实现并购价值——以管理的充分整合推进钢铁企业重组的合力建设

中国钢铁行业进入兼并重组时代 随着经济全球化,钢铁行业作为我国国民经济的重要行业,还处于从钢铁大国向钢铁强国转变的成长阶段,这也是行业进行产业结构调整、产品优化升级的机遇期。这一阶段,钢铁企业联合、兼并和资产重组将成为钢铁工业结构调整的中心环节和突破口。     

Mechanism design to the budget constrained buyer: a canonical mechanism approach

The present paper studies the problem on multi-dimensional mechanisms in which the buyer’s taste and budget are his private information. The paper investigates the problem by way of a canonical mechanism in the traditional one-dimensional setting: function of one variable, the buyer’s taste. In our multi-dimensional context, this is an indirect mechanism. The paper characterizes the optimal canonical mechanism and shows that this approach loses no generality with respect to the direct (multi-dimensional) mechanism.     

The acquisition queue

We propose a new queueing model named the acquisition queue. It differs from conventional queueing models in that the server not only serves customers, but also performs acquisition of new customers. The server has to divide its energy between both activities. The number of newly acquired customers is uncertain, and the effect of the server’s acquisition efforts can only be seen after some fixed time period δ (delay). The acquisition queue constitutes a (δ+1)-dimensional Markov chain. The limiting queue length distribution is derived in terms of its probability generating function, and an exact expression for the mean queue length is given. For large values of δ the numerical procedures needed for calculating the mean queue length become computationally cumbersome. We therefore complement the exact expression with a fluid approximation. One of the key features of the acquisition queue is that the server performs more acquisition when the queue is small. Together with the delay, this causes the queue length process to show a strongly cyclic behavior. We propose and investigate several ways of planning the acquisition efforts. In particular, we propose an acquisition scheme that is designed specifically to reduce the cyclic behavior of the queue length process. This research was financially supported by the European Network of Excellence Euro-NGI. The work of the second author was supported in part by a TALENT grant from the Netherlands Organisation for Scientific Research (NWO).     

Optimal information acquisition for a linear quadratic control problem

This paper develops a generalization of the linear quadratic control problem with partial information. As in the standard partial information setting, it is assumed that the state variable is only observed with noise. The idea in this paper is that the information level may be chosen optimally. In real life information is costly to acquire. It is therefore a trade off between the costs of getting detailed information and the increased value this information gives. We believe that the technique we present should have potential for application within both economics and engineering.     

Optimal resource acquisition policy for a newsvendor under supply risk

We consider a single-period manufacturing problem involving uncertainty in the availability of a production resource. The resource is stochastically available at the regular cost, but by paying a premium it is possible to reserve and hence guarantee any desired level of the resource in advance. Given the resource consumption rates for a number of products, the manufacturer needs to determine the optimal forward purchase quantity of the resource such that expected profit from selling the products is maximized. The problem is formulated as an extension of the traditional multi-item newsvendor problem. A computational optimization procedure is developed for solving the problem. We find that depending on the profit margins associated with the products, the optimal reservation amount of the resource may increase or decrease as the supply variability increases. The demand volatilities of products are observed to influence the forward purchase quantity of the resource in a similar manner.     

Knowledge representation and acquisition in expert systems for pattern recognition

A new approach to the design of fuzzy expert systems is proposed. The representation of knowledge and the formation of statements by fuzzy logic tools are discussed in detail. A model of fuzzy inference is described. Primary attention is given to automatic extraction of knowledge (fuzzy inference rules) from a set of precedents. Various performance criteria for rules are introduced, and an algorithm for their generation (the method of effective restrictions) is proposed. An extension of the type of admissible rules by introducing a fuzzy disjunction operation is described. The possibility of optimizing the rules found is explored. The benefits of the approaches proposed are illustrated by experiments.     

Another design for sundials

Based on Kepler's laws we calculate the position of the sun as a function of the date, the local time, the latitude and longitude and use the resulting formula to construct a portable sundial which works without being adjusted to the cardinal directions (i.e. there is no need for an additional compass).     

A knowledge acquisition method for determining utilities of linguistic values for product factors

This paper proposes a fuzzy knowledge acquisition method to discover simplified fuzzy if-then rules, where the antecedent and consequent parts of a fuzzy if-then rule are referred to as a combination of linguistic values and the corresponding utility, respectively, from questionnaire data regarding the consumers’ subjective evaluation for a product or service. The main aim of the proposed method is to support decision makers in making appropriate marketing strategies, by identifying factors of concern to consumers through the analysis of the combinations of linguistic values with higher or lower utilities. To demonstrate the usefulness of the proposed method, computer simulations and possible marketing strategy analysis are performed on the rice taste data and the questionnaire data that evaluates the service quality of fast food stores.     

Decision support for spare parts acquisition in post product life cycle

A major task in service management is the timely and cost efficient provision of spare parts for durable products. This especially holds good, when the regular production of the product, its components and parts has been discontinued, but customer service still has to be guaranteed for quite a long time. In such post product life cycle period, three options are available to organize the spare parts acquisition, namely (i) setting up a single large order within the final lot of regular production, (ii) performing extra production runs until the end of service and (iii) using remanufacturing to gain spare parts from used products. These three options are characterized by different cost and flexibility properties. Due to the time-variability and uncertainty of demands for spare parts and also that of the returns of used products, it is a challenging task to find out the optimal combination of these three options. In this paper we show how this problem can be modeled and solved by Decision Tree and stochastic Dynamic Programming procedure. Based on the Dynamic Programming approach a heuristic method is proposed, which can be employed to come up with a simple solution procedure for real-world spare parts acquisition problems during the post product life cycle. A numerical example is presented to demonstrate the application of the solution methods described in the paper.     

Informational acquisition and cognitive models

Life forms must organize information into cognitive models reflecting the outside environment, and in a complex and changing environment a life form must constantly select and organize this mass of information to avoid slipping into a chaotic cognitive state. The task of developing and maintaining adaptive cognitive models can be understood through two processes, crucial to regulating the interconnections between environmental elements. The inclusion and exclusion of information follows a process designated by P and the process by which cognitive models change is designated by K. Higher order concepts are created by reducing the interconnections between elements to a minimal number to avoid cognitive chaos. © 2004 Wiley Periodicals, Inc. Complexity 9:31–37, 2004     

A decision approach to competitive electronic sealed-bid auctions for land

Electronic markets for land are innovative techniques potentially advantageous to buyers and private sellers, the latter being interested in sealed-bid auctions assuring high levels of competition among many bidders so that coalitions and cooperative games are ruled out. Land electronic tendering requires sufficient online information for bidders such as valuation reports by prestigious surveyors. To help the bidder make his best choice, we propose a decision model for moderately pessimistic players facing tenders where competition among a great number of independent antagonists excludes the use of cooperative games and involves strict uncertainty. A worked example concerning farmland in Spain is presented.     

Cost of ownership model for spare engines purchase for the Korean navy acquisition program

Major weapon system acquisition programmes often require high initial purchase cost which can be a burden for the procurement of a highly reliable system. In order to avoid the tendency of acquiring a less expensive weapon system with lower performance, a cost of ownership (COO) model can be applied to assess the lifetime cost of the weapon system. In many existing cost estimation models for weapon systems, the failure rate of the system is assumed to be constant and the functional relationship between the initial purchase cost and maintenance cost is not well defined. In this paper, we propose a revised COO model where random effects models are employed to accommodate the variations of the system failure frequency and repair time. It is expected that our model can contribute to the cost-effective procurement of spare engines for the Korean Navy acquisition programme within the limited national defence budget.     

Polynomial design for continuous-time control

The theory of polynomial design for multivariable continuous-timecontrol systems is developed. It is assumed that inputs arestationary stochastic, and a variation is applied to the controllerin order to find the transfer matrix of the latter which willminimize an appropriate H₂ norm.     

Reserve design for species preservation

The problem of designing a natural area reserve for the preservation of species is approached as a zero-one integer program. The least-cost assemblage of parcels is sought for different numbers of species whose locales must be included within the reserve. The reserve itself is designed to include core parcels and buffer parcels which surround and protect the core. Compactness and contiguity of the reserve are promoted by the problem formulation. Solution is by a combination of a greedy heuristic followed by heuristic concentration which achieves a reduced set of variables for the zero-one program.     

Hexagonal design for stiffening trusses

Annali di Matematica Pura ed Applicata (1923 -) - We consider the problem of choosing the best design for stiffening trusses of plates, such as bridges. We suggest to cover the plate with regular...     

District design for arc-routing applications

In this paper we address the problem of district design for the organisation of arc-routing activities. In particular, the focus is on operations like winter gritting and road maintenance. The problem involves how to allocate the road network edges to a set of depots with given locations. The collection of edges assigned to a facility forms a district in which routes have to be designed that start and end at the facility. Apart from the ability to support good arc routing, well-designed districts for road-maintenance operations should have the road network to be serviced connected and should define clear geographical boundaries. We present three districting heuristics and evaluate the quality of the partitions by solving capacitated arc routing problems in the districts, and by comparing the solution values with a multi-depot CARP cutting plane lower bound. Our experiments reveal that based on global information about the distribution system (ie the number of facilities or districts, the average edge demand and the vehicle capacity) and by using simple guidelines, an adequate districting policy may be selected.     

Optimal design for smoothing splines

In the common nonparametric regression model we consider the problem of constructing optimal designs, if the unknown curve is estimated by a smoothing spline. A special basis for the space of natural splines is introduced and the local minimax property for these splines is used to derive two optimality criteria for the construction of optimal designs. The first criterion determines the design for a most precise estimation of the coefficients in the spline representation and corresponds to D-optimality, while the second criterion is the G-optimality criterion and corresponds to an accurate prediction of the curve. Several properties of the optimal designs are derived. In general, D- and G-optimal designs are not equivalent. Optimal designs are determined numerically and compared with the uniform design.