全文获取类型
收费全文 | 384篇 |
免费 | 6篇 |
国内免费 | 3篇 |
专业分类
管理学 | 75篇 |
民族学 | 1篇 |
人口学 | 1篇 |
丛书文集 | 19篇 |
理论方法论 | 7篇 |
综合类 | 164篇 |
社会学 | 51篇 |
统计学 | 75篇 |
出版年
2024年 | 2篇 |
2023年 | 7篇 |
2022年 | 6篇 |
2021年 | 9篇 |
2020年 | 7篇 |
2019年 | 7篇 |
2018年 | 10篇 |
2017年 | 12篇 |
2016年 | 7篇 |
2015年 | 7篇 |
2014年 | 7篇 |
2013年 | 21篇 |
2012年 | 21篇 |
2011年 | 14篇 |
2010年 | 9篇 |
2009年 | 11篇 |
2008年 | 12篇 |
2007年 | 25篇 |
2006年 | 17篇 |
2005年 | 16篇 |
2004年 | 17篇 |
2003年 | 19篇 |
2002年 | 9篇 |
2001年 | 13篇 |
2000年 | 15篇 |
1999年 | 14篇 |
1998年 | 10篇 |
1997年 | 10篇 |
1996年 | 8篇 |
1995年 | 13篇 |
1994年 | 3篇 |
1993年 | 9篇 |
1992年 | 8篇 |
1991年 | 2篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有393条查询结果,搜索用时 46 毫秒
31.
The problem of computing the strength and performing optimal reinforcement for an edge-weighted graph G(V, E, w) is well-studied. In this paper, we present fast (sequential linear time and parallel logarithmic time) on-line algorithms for optimally reinforcing the graph when the reinforcement material is available continuously on-line. These are the first on-line algorithms for this problem. We invest O(|V|3|E|log|V|) time (equivalent to (|V|) invocations of the fastest known algorithms for optimal reinforcement) in preprocessing the graph before the start of our algorithms. It is shown that the output of our on-line algorithms is as good as that of the off-line algorithms. Thus our algorithms are better than the fastest off-line algorithms in situations when a sequence of more than (|V|) reinforcement problems need to be solved. The key idea is to make use of ideas underlying the theory of Principal Partition of a Graph. Our ideas are easily generalized to the general setting of polymatroid functions. We also present a new efficient algorithm for computation of the Principal Sequence of a graph. 相似文献
32.
Let k 5 be a fixed integer and let m = (k – 1)/2. It is shown that the independence number of a C
k-free graph is at least c
1[ d(v)1/(m – 1)](m – 1)/m
and that, for odd k, the Ramsey number r(C
k, K
n) is at most c
2(n
m + 1/log n)1/m
, where c
1 = c
1(m) > 0 and c
2 = c
2(m) > 0. 相似文献
33.
Maria Liazi Ioannis Milis Fanny Pascual Vassilis Zissimopoulos 《Journal of Combinatorial Optimization》2007,14(4):465-474
The Densest k-Subgraph (DkS) problem asks for a k-vertex subgraph of a given graph with the maximum number of edges. The problem is strongly NP-hard, as a generalization of
the well known Clique problem and we also know that it does not admit a Polynomial Time Approximation Scheme (PTAS). In this paper we focus on
special cases of the problem, with respect to the class of the input graph. Especially, towards the elucidation of the open
questions concerning the complexity of the problem for interval graphs as well as its approximability for chordal graphs,
we consider graphs having special clique graphs. We present a PTAS for stars of cliques and a dynamic programming algorithm
for trees of cliques.
M.L. is co-financed within Op. Education by the ESF (European Social Fund) and National Resources.
V.Z. is partially supported by the Special Research Grants Account of the University of Athens under Grant 70/4/5821. 相似文献
34.
In this paper we show the sufficient conditions for the decomposition of the complete bipartite graphs K
2m,2n
and K
2n+1,2n+1−F into cycles of two different lengths 4 and 2t, t>2, where F is a 1-factor of K
2n+1,2n+1. After that we prove that the results are true for t=5 and 6.
Dedicated to Frank K. Hwang on the occasion of his 65th birthday.
An erratum to this article can be found at 相似文献
35.
Suppose G is a graph of p vertices. A proper labeling
f of G is a one-to-one mapping f:V(G)→{1,2,…,p}. The cyclic bandwidth sum of
G
with respect to
f is defined by CBS
f
(G)=∑
uv∈E(G)|f(v)−f(u)|
p
, where |x|
p
=min {|x|,p−|x|}. The cyclic bandwidth sum of G is defined by CBS(G)=min {CBS
f
(G): f is a proper labeling of G}. The bandwidth sum of
G
with respect to
f is defined by BS
f
(G)=∑
uv∈E(G)|f(v)−f(u)|. The bandwidth sum of G is defined by BS(G)=min {BS
f
(G): f is a proper labeling of G}. In this paper, we give a necessary and sufficient condition for BS(G)=CBS(G), and use this to show that BS(T)=CBS(T) when T is a tree. We also find cyclic bandwidth sums of complete bipartite graphs.
Dedicated to Professor Frank K. Hwang on the occasion of his 65th birthday.
Supported in part by the National Science Council under grants NSC91-2115-M-156-001. 相似文献
36.
Suppose S is a subset of a metric space X with metric d. For each subset D⊆{d(x,y):x,y∈S,x≠y}, the distance graph G(S,D) is the graph with vertex set S and edge set E(S,D)={xy:x,y∈S,d(x,y)∈D}. The current paper studies distance graphs on the n-space R
1
n
with 1-norm. In particular, most attention is paid to the subset Z
1
n
of all lattice points of R
1
n
. The results obtained include the degrees of vertices, components, and chromatic numbers of these graphs.
Dedicated to Professor Frank K. Hwang on the occasion of his 65th birthday.
Supported in part by the National Science Council under grant NSC-94-2115-M-002-015. Taida Institue for Mathematical Sciences,
National Taiwan University, Taipei 10617, Taiwan. National Center for Theoretical Sciences, Taipei Office. 相似文献
37.
马石安 《江汉大学学报(人文科学版)》2000,19(3):78-82
介绍一个能对空气处理过程进行自动分析的计算机软件,该软件能生成湿空气的焓-湿图,显示空气处理过程,并对娄在动处理,为空调系统设备选择提供其础数据。 相似文献
38.
陆书环 《济南大学学报(社会科学版)》1997,(1)
本文给出了一类图P_1(?)T_n和P_1(?)T_3,并给出了其优美性的证明. 相似文献
39.
研究了以银电极为指示电极、多次加入格氏电位滴定测定铜材中痕量氯的方法和实验条件,回收率93.4%,相对标准偏差6.5%. 相似文献
40.
Wenan Zang 《Journal of Combinatorial Optimization》1998,2(2):117-188
A fully odd K4 is a subdivision of K4 such that each of the six edges of the K4 is subdivided into a path of odd length. In 1974, Toft conjectured that every graph containing no fully odd K4 can be vertex-colored with three colors. The purpose of this paper is to prove Toft's conjecture. 相似文献