全文获取类型
| 收费全文 | 481篇 |
| 免费 | 1篇 |
专业分类
| 482篇 |
出版年
| 2021年 | 5篇 |
| 2019年 | 13篇 |
| 2018年 | 9篇 |
| 2017年 | 11篇 |
| 2016年 | 9篇 |
| 2015年 | 10篇 |
| 2013年 | 78篇 |
| 2011年 | 5篇 |
| 2010年 | 6篇 |
| 2009年 | 4篇 |
| 2007年 | 6篇 |
| 2006年 | 7篇 |
| 2005年 | 11篇 |
| 2004年 | 9篇 |
| 2003年 | 5篇 |
| 2001年 | 4篇 |
| 2000年 | 9篇 |
| 1999年 | 6篇 |
| 1998年 | 5篇 |
| 1997年 | 9篇 |
| 1996年 | 12篇 |
| 1995年 | 4篇 |
| 1994年 | 10篇 |
| 1993年 | 6篇 |
| 1992年 | 7篇 |
| 1991年 | 14篇 |
| 1990年 | 8篇 |
| 1989年 | 12篇 |
| 1988年 | 6篇 |
| 1987年 | 11篇 |
| 1986年 | 9篇 |
| 1985年 | 11篇 |
| 1984年 | 9篇 |
| 1983年 | 7篇 |
| 1982年 | 6篇 |
| 1981年 | 8篇 |
| 1980年 | 10篇 |
| 1979年 | 7篇 |
| 1978年 | 8篇 |
| 1977年 | 8篇 |
| 1976年 | 9篇 |
| 1975年 | 6篇 |
| 1974年 | 11篇 |
| 1973年 | 8篇 |
| 1972年 | 9篇 |
| 1971年 | 13篇 |
| 1970年 | 3篇 |
| 1969年 | 6篇 |
| 1968年 | 5篇 |
| 1967年 | 3篇 |
排序方式： 共有482条查询结果，搜索用时 0 毫秒
101.
Richard A. Aborisade 《African Security Review》2018,27(2):177-190
This article focuses on the systemic failures of the Nigerian police force to unravel the mysteries surrounding homicides in the country, along with the security, social and political implications of the ongoing trend. The article draws on documented pieces of evidence of high-profile murders, along with the causes of the upsurge in murder incidences and the inhibitive factors relating to the investigative procedures of the police. The suitability of the theory of subaltern realism and the concept of third-world security predicaments in explaining the peculiarities of Nigeria’s internal security challenges is examined, along with the problems of the legitimacy of political regimes and weak borders. There is a need for the National Assembly of Nigeria to exercise its constituted powers in reawakening and supervising investigations into dormant cases of murder through its committees on police affairs, public safety and national security. The police should check its organisational failures, which may be related to using the wrong investigative approaches, low levels of information, limited resources, corrupt practices, and pressure to obtain quick results. 相似文献
102.
Marjolein B.A. van Asselt 《Contemporary Security Policy》2018,39(4):590-600
While security points to a deliberate harming of humans and/or the environment, safety refers to unintended damage. In this view point, I will analyse how the distinction between safety and security matters in the practice of accident investigation and I will argue that the division between the fields is problematic for the assessment of security-related safety risks. Drawing on the case of the our accident investigation into the downing of flight MH17 above Ukraine in 2014, I highlight key dilemmas the Dutch Safety Board dealt with. 相似文献
103.
Richard A. Bitzinger 《战略研究杂志》2016,39(5-6):762-789
ABSTRACTEven with sizable economic inputs, access to foreign technologies, and considerable political will, China, up until the late 1990s, experienced only limited success when it came to the local design, development, and manufacture of advanced conventional weapons. Not surprisingly, therefore, reforming the local defense industry in order to upgrade its technology base and manufacturing capabilities and to make armaments production more efficient and cost-effective has long preoccupied the Chinese leadership. The fact that most of these efforts had little positive impact on the country’s military technological and industrial capabilities only encouraged Beijing to experiment with additional reforms in the hopes of finally getting it right. 相似文献
104.
It has been argued that the discovery of a new natural resource greatly increases the risk of conflict. This research aims to study the effect of natural resources on military spending, using the data from rentier states in the Middle East and North Africa (MENA) countries from 1987 to 2012. In considering the ‘resource curse,’ the types of natural resources matter. Our empirical results demonstrate that the ‘resource curse’ arising from the abundance of certain natural resources, particularly oil and forest resources, leads to increases in military spending. In contrast, the rent from coal and natural gas has a negative impact on military spending, while the rent from minerals has no impact on military spending, controlling for GDP growth and per capita income. 相似文献
105.
We consider parallel‐machine scheduling with a common server and job preemption to minimize the makespan. While the non‐preemptive version of the problem is strongly NP‐hard, the complexity status of the preemptive version has remained open. We show that the preemptive version is NP‐hard even if there is a fixed number of machines. We give a pseudo‐polynomial time algorithm to solve the case with two machines. We show that the case with an arbitrary number of machines is unary NP‐hard, analyze the performance ratios of some natural heuristic algorithms, and present several solvable special cases. © 2017 Wiley Periodicals, Inc. Naval Research Logistics 64: 388–398, 2017 相似文献
106.
The Replenishment at Sea Planner (RASP) is saving the U.S. Navy millions of dollars a year by reducing fuel consumption of its Combat Logistics Force (CLF). CLF shuttle supply ships deploy from ports to rendezvous with underway U.S. combatants and those of coalition partners. The overwhelming commodity transferred is fuel, ship‐to‐ship by hoses, while other important packaged goods and spare parts are high‐lined, or helicoptered between ships. The U.S. Navy is organized in large areas of responsibility called numbered fleets, and within each of these a scheduler must promulgate a daily forecast of CLF shuttle operations. The operational planning horizon extends out several weeks, or as far into the future as we can forecast demand. We solve RASP with integer linear optimization and a purpose‐built heuristic. RASP plans Replenishment‐at‐Sea (RAS) events with 4‐hour (Navy watch) time fidelity. For five years, RASP has served two purposes: (1) it helps schedulers generate a daily schedule and animates it using Google Earth, and (2) it automates reports command‐to‐ship messages that are essential to keep this complex logistics system operating. 相似文献
107.
Richard A.I. Johnson 《Defence and Peace Economics》2017,28(3):272-297
Arms transfers provide exporters an avenue to provide security to other states while gaining economic benefits. Arms transfers provide importers an avenue to gain security without having to rely on alliances. Past research uses aggregate measures of the monetary or security value of major weapon system transfers without accounting for strategic differences in possible use in interstate and civil conflict. This article presents a data set on interstate transfers of major weapon systems between 1950 and 2010 building upon Stockholm Peach Research Institute’s Arms Trade Register with several improvements. First, it disaggregates land weapons and air weapons into categories reflecting their strategic capabilities. Second, model level characteristics (e.g. age, speed, and range) are drawn from Jane’s Defence sources. Additionally, the data set covers a larger range of time and states than previous data sets categorizing arms. To demonstrate the usefulness, this article first presents summary statistics of the data set and then replicates an earlier test to show that the effect of human rights and regime types on United States transfers differs across the categories of arms compared to alternative measures of arms transfers. 相似文献
108.
The scheduling problem addressed in this paper concerns a manufacturer who produces a variety of product types and operates in a make‐to‐order environment. Each customer order consists of known quantities of the different product types, and must be delivered as a single shipment. Periodically the manufacturer schedules the accumulated and unscheduled customer orders. Instances of this problem occur across industries in manufacturing as well as in service environments. In this paper we show that the problem of minimizing the weighted sum of customer order delivery times is unary NP‐hard. We characterize the optimal schedule, solve several special cases of the problem, derive tight lower bounds, and propose several heuristic solutions. We report the results of a set of computational experiments to evaluate the lower bounding procedures and the heuristics, and to determine optimal solutions. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005. 相似文献
109.
In this paper, we extend the results of Ferguson M. Naval Research Logistics 8 . on an end‐product manufacturer's choice of when to commit to an order quantity from its parts supplier. During the supplier's lead‐time, information arrives about end‐product demand. This information reduces some of the forecast uncertainty. While the supplier must choose its production quantity of parts based on the original forecast, the manufacturer can wait to place its order from the supplier after observing the information update. We find that a manufacturer is sometimes better off with a contract requiring an early commitment to its order quantity, before the supplier commits resources. On the other hand, the supplier sometimes prefers a delayed commitment. The preferences depend upon the amount of demand uncertainty resolved by the information as well as which member of the supply chain sets the exchange price. We also show conditions where demand information updating is detrimental to both the manufacturer and the supplier. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005 相似文献
110.
This paper addresses optimal power allocation in a wireless communication network under uncertainty. The paper introduces a framework for optimal transmit power allocation in a wireless network where both the useful and interference coefficients are random. The new approach to power control is based on a stochastic programming formulation with probabilistic SIR constraints. This allows to state the power allocation problem as a convex optimization problem assuming normally or log‐normally distributed communication link coefficients. Numerical examples illustrate the performance of the optimal stochastic power allocation. A distributed algorithm for the decentralized solution of the stochastic power allocation problem is discussed. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2005 相似文献