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371.
The loading problem involves the optimal allocation of n objects, each having a specified weight and value, to m boxes, each of specified capacity. While special cases of these problems can be solved with relative ease, the general problem having variable item weights and box sizes can become very difficult to solve. This paper presents a heuristic procedure for solving large loading problems of the more general type. The procedure uses a surrogate procedure for reducing the original problem to a simpler knapsack problem, the solution of which is then employed in searching for feasible solutions to the original problem. The procedure is easy to apply, and is capable of identifying optimal solutions if they are found.  相似文献   
372.
This paper examines a convex programming problem that arises in several contexts. In particular, the formulation was motivated by a generalization of the stochastic multilocation problem of inventory theory. The formulation also subsumes some “active” models of stochastic programming. A qualititative analysis of the problem is presented and it is shown that optimal policies have a certain geometric form. Properties of the optimal policy and of the optimal value function are described.  相似文献   
373.
This article considers the problem of allocating a fixed budget among alternative air-to-ground weapons. The weapon-budgeting problem is high-dimensional, involving all feasible combinations of aircraft, weapons, and targets. The decision maker's utility function is defined over kills of the various target types, but it is unrealistic to expect him to write down the mathematical formula for this function. The article suggests two procedures for reducing the dimension of the maximization problem and operating without exact knowledge of the utility function. The first procedure uses successive linear approximations to generate the set of “efficient” or undominated weapon allocations. The second procedure applies separability restrictions to the utility function, thereby reducing the overall maximization problem to a sequence of low-dimensional subproblems.  相似文献   
374.
Book reviews     
America's Secret Power: the CIA in a Democratic Society. By Loch K. Johnson. Oxford University Press, New York (1989), ISBN 0–19–505490–3, $24.95

The Bundeswehr and Western Security. Edited by Stephen F. Szabo. Houndmills, Basingstoke, and Macmillan, London (1990), ISBN 0–333–49880–1, £45.00

Symbolic Defense: the Cultural Significance of the Strategic Defense Initiative. By Edward Tabor Linenthal. University of Illinois Press, Chicago, IL (1989), ISBN 0–252–01619‐X, $19.95

Rethinking European Security. Edited by Furio Cerutti and Rodolfo Ragionieri. Crane Russak, New York (1990), £29.00

Alternative Conventional Defense Postures in the European Theater, Vol. 1: The Military Balance and Domestic Constraints. Edited by Hans Günter Brauch and Robert Kennedy, Crane Russak, New York (1990), £32.00

The Gulf War. Edited by Hanns Maull and Otto Pick. Pinter, London (1989), ISBN 0–86187–763–2, £36.00  相似文献   

375.
We develop an approximate planning model for a distributed computing network in which a control system oversees the assignment of information flows and tasks to a pool of shared computers, and describe several optimization applications using the model. We assume that the computers are multithreaded, and have differing architectures leading to varying and inconsistent processing rates. The model is based on a discrete‐time, continuous flow model developed by Graves [Oper Res 34 (1986), 522–533] which provides the steady‐state moments of production and work‐in‐queue quantities. We make several extensions to Graves' model to represent distributed computing networks. First, we approximately model control rules that are nonlinear functions of the work‐in‐queue at multiple stations through a linearization approach. Second, we introduce an additional noise term on production and show its use in modeling the discretization of jobs. Third, we model groups of heterogeneous computers as aggregate, “virtual computing cells” that process multiple tasks simultaneously, using a judiciously selected control rule. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005.  相似文献   
376.
Throughout the world, there is a large number of young, and even not-so-young, scholars who are reading for higher degrees in strategic, security and defense studies, or engaged in analytical research in research institutes, think-tanks or consultancies; they bring to the subject innovative and fresh perspectives often ignored or missed by more established scholars. Most of these people have yet to make their mark in the defense and security field. The Editors of Defense & Security Analysis are resolved to tap this value source of information, observation, analysis and critical study by offering a new section of the journal for their views to be given an opportunity to be aired. Submissions of up to 3,000 words are encouraged from University Master's and Doctoral candidates and post-doctoral researchers.  相似文献   
377.
This article examines optimal path finding problems where cost function and constraints are direction, location, and time dependent. Recent advancements in sensor and data‐processing technology facilitate the collection of detailed real‐time information about the environment surrounding a ground vehicle, an airplane, or a naval vessel. We present a navigation model that makes use of such information. We relax a number of assumptions from existing literature on path‐finding problems and create an accurate, yet tractable, model suitable for implementation for a large class of problems. We present a dynamic programming model which integrates our earlier results for direction‐dependent, time and space homogeneous environment, and consequently, improves its accuracy, efficiency, and run‐time. The proposed path finding model also addresses limited information about the surrounding environment, control‐feasibility of the considered paths, such as sharpest feasible turns a vehicle can make, and computational demands of a time‐dependent environment. To demonstrate the applicability and performance of our path‐finding algorithm, computational experiments for a short‐range ship routing in dynamic wave‐field problem are presented. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012  相似文献   
378.
For 74 days in mid-1999, India waged an intense war against intruding Pakistani forces on the Indian side of the Line of Control dividing Kashmir in the Himalayas. The Indian Air Force (IAF) was a key contributor to India's eventual victory in that war. Among other things, the IAF's combat performance showed how the skillful application of air-delivered firepower, especially if unmatched by the other side, can shorten and facilitate the outcome of an engagement that might otherwise have persisted indefinitely. It also showed that a favorable position in the conventional balance remains strategically useful even in conditions of mutual nuclear deterrence.  相似文献   
379.
This article focuses on the relationship between the threat perception analyses of the British Admiralty and the strategic orientation of the Royal Navy at the outset of the twentieth century. The current view is that this was an era when fear of France and Russia drove British naval policy. However, as this article will show, Britain's Naval Intelligence Department formed a low opinion of French and Russian naval capabilities at this time and this negative evaluation exerted considerable influence over decision making. The belief that, owing to multiple qualitative deficiencies, these powers could definitely be beaten in battle lessened the standing of the Franco-Russian naval challenge and freed the Admiralty to consider the danger posed by other possible enemies, most notably Germany.  相似文献   
380.
This article examines the nuclear command and control (C2) system implemented in Pakistan since 1998, and discusses its potential consequences for the risk of inadvertent or unauthorised use of nuclear weapons. I argue that troubled civil-military relations and Pakistan's doctrine of ‘asymmetric escalation’ account for the creation of a command and control system with different characteristics during peacetime and military crises. Although the key characteristics of Pakistan's nuclear C2 system allow relatively safe nuclear operations during peacetime, operational deployment of nuclear weapons during military standoffs is likely to include only rudimentary protections against inadvertent or unauthorised nuclear release. The implication of this study is that any shift from peacetime to wartime command and control procedures is likely to further destabilise Indo-Pakistani relations during the early stages of a diplomatic or military standoff, and introduce a non-trivial risk of accidental escalation to the nuclear level.  相似文献   
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