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11.
The aim of the study was to explore the relationship between subjective economic status and indicators of successful aging to life satisfaction trajectories among the elderly in Taiwan. Data were from the four waves of “Survey of Health and Living Status of the Elderly in Taiwan”. Hierarchical linear modeling was conducted. Subjective economic status was measured by childhood economic status and time-varying economic satisfaction. Time-varying physical, mental, and social successful aging variables and demographics were also used to describe the trajectory of life satisfaction. Life satisfaction showed a slightly decreasing but generally stationary trend across time. The concurrent economic satisfaction was associated with life satisfaction trajectory, but childhood economic status was not significant. The time-varying depressive symptoms, cognitive function and social support were related to the life satisfaction trajectory. Policy on the elderly should take particular account of the economic security, mental health, and social support of the elderly.  相似文献   
12.
Given a set S of starting vertices and a set T of terminating vertices in a graph G = (V,E) with non-negative weights on edges, the minimum Steiner network problem is to find a subgraph of G with the minimum total edge weight. In such a subgraph, we require that for each vertex s S and t T, there is a path from s to a terminating vertex as well as a path from a starting vertex to t. This problem can easily be proven NP-hard. For solving the minimum Steiner network problem, we first present an algorithm that runs in time and space that both are polynomial in n with constant degrees, but exponential in |S|+|T|, where n is the number of vertices in G. Then we present an algorithm that uses space that is quadratic in n and runs in time that is polynomial in n with a degree O(max {max {|S|,|T|}–2,min {|S|,|T|}–1}). In spite of this degree, we prove that the number of Steiner vertices in our solution can be as large as |S|+|T|–2. Our algorithm can enumerate all possible optimal solutions. The input graph G can either be undirected or directed acyclic. We also give a linear time algorithm for the special case when min {|S|,|T|} = 1 and max {|S|,|T|} = 2.The minimum union paths problem is similar to the minimum Steiner network problem except that we are given a set H of hitting vertices in G in addition to the sets of starting and terminating vertices. We want to find a subgraph of G with the minimum total edge weight such that the conditions required by the minimum Steiner network problem are satisfied as well as the condition that every hitting vertex is on a path from a starting vertex to a terminating vertex. Furthermore, G must be directed acyclic. For solving the minimum union paths problem, we also present algorithms that have a time and space tradeoff similar to algorithms for the minimum Steiner network problem. We also give a linear time algorithm for the special case when |S| = 1, |T| = 1 and |H| = 2.An extended abstract of part of this paper appears in Hsu et al. (1996).Supported in part by the National Science Foundation under Grants CCR-9309743 and INT-9207212, and by the Office of Naval Research under Grant No. N00014-93-1-0272.Supported in part by the National Science Council, Taiwan, ROC, under Grant No. NSC-83-0408-E-001-021.  相似文献   
13.
A central premise of the industry change literature is that firms change their strategic actions when an industry changes. Industry convergence (IC), the blending of boundaries between industries creating competition among firms that previously did not compete, is increasingly impacting many industries and is a salient case of industry change. Acquisitions are an important action shaping the course of IC because they trigger imitation and bandwagon effects further accelerating IC. This paper focuses on why and when learning from alliances reduces uncertainty resulting in acquisitions during IC: an ‘alliance experience transfer effect’. We demonstrate the utility of this mechanism for the substitution‐based form of IC that occurred between the telecommunications equipment and computer networking industries. Our key insight is that when the extent of IC is low there are significant transfer effects but, as the extent of IC increases, firms have access to an expanding volume and diversity of information sources that reduce uncertainty, thus weakening the transfer effect mechanism. We contribute to the alliance–acquisition relationship and learning literatures by demonstrating that the alliance experience transfer effect mechanism explains changes in firm strategic action (alliancing and acquiring) as the extent of IC changes. We also introduce a semi‐convergence perspective by directly measuring the extent of IC.  相似文献   
14.
We consider the scheduling of truck arrivals at an air cargo terminal. By coordinating arrivals of cargo delivery trucks with outbound flight departure schedules, some of the shipments can be transferred directly to the departing flights, while others will be stored at the terminal's storage facility and incur extra handling and storage costs. The objective is to obtain a feasible schedule so as to minimize the total cost of operations. We formulate the problem as a time‐indexed integer program and show that, even with limited number of unloading docks at the terminal, the problem is non‐trivial (NP‐hard in the strong sense). Our solution method includes an exact solution procedure to determine an optimal unloading sequence for the shipments carried by each truck, together with a Lagrangian relaxation‐based heuristic for assigning trucks to truck docks and determining truck arrival times. We conducted computational experiments to test the performance of our solution method. Computational results show that our method can generate near‐optimal solutions efficiently. Our simulation results indicate that the scheduling approach proposed in this paper has the potential to generate significant cost savings over a first‐come, first‐served approach currently used at the air cargo terminal that we observed.  相似文献   
15.
Multimedia message service (MMS) provides more multimedia communication with entertainment effects than current text-based short message service (SMS). While many reports indicate that the mobile Internet market will be huge, little is known about whether people will accept MMS. This study applies innovation diffusion theory to examine the factors that influence the adoption of MMS. The proposed model was empirically evaluated by using survey data collected from 207 users concerning their perceptions of MMS. The findings indicate that perceptions of use were different over innovation diffusion stages. Specifically, there was a significant difference between potential adopters and users. The results may provide further insights into MMS marketing strategies.  相似文献   
16.
Chinese version of the OSI: A validation study   总被引:5,自引:0,他引:5  
This article examines the construct validity of the Occupational Stress Indicator (OSI) in its Chinese version as well as its criterion-oriented validity against self-reported data on absenteeism and accidents, using a final sample of 1054 workers in the Chinese manufacturing and power industries. The divergent and convergent validities of five of the OSI scales—Job satisfaction, Physical ill-health, Mental ill-health, Type A behaviour and Control—were examined by a multimethod-multitrait matrix technique. Results indicated that the Chinese OSI had fairly good validity in relation to other well-established measures as well as relevant organizational behaviours.  相似文献   
17.
社会组织领域的政治关联现象日益显著,但政治关联究竟如何影响社会组织有效性,其隐藏的作用机制又是什么?这是学术界尚未明晰的重要课题。针对254家社会组织的问卷调查发现,社会组织政治关联会正向影响组织有效性,这一关系受到组织自主性的中介作用影响。更进一步的研究显示,制度支持能调节上述中介关系。具体而言,当制度支持水平较高时,这一效应将会增强;当制度支持水平较低时,政治关联通过组织自主性间接影响组织有效性的效应就会减弱。这一发现,一方面增进了我们对社会组织政治关联的理解,另一方面也为提升社会组织有效性的理论和实践提供了重要启示。  相似文献   
18.
被称为日本民族"诗神"的谷川俊太郎诗歌中融入了浓厚的禅宗因素。其诗歌超越生死对立的纠缠,从"死"的角度回望"生",讴歌生命之于死亡的淡泊和从容,在"闲寂"中寻找"生"的种种可能性,追求瞬间永恒的华丽的生命感,并以"禅问答"、禅家语等默然的方式与世界交流,贯穿其中的内核便是禅宗对生命本真的解读。  相似文献   
19.
作者对参编中国少数民族简史丛书40多年来的治史道路进行了回顾,指出近年发生的贬煞简史丛书现象,进而用三点论据阐发出了简史丛书非凡说,又概括出反映中国民族史学时代特性的太极柔中.  相似文献   
20.
This paper addresses a batch delivery single-machine scheduling problem in which jobs have an assignable common due window. Each job will incur an early (tardy) penalty if it is early (tardy) with respect to the common due window under a given schedule. There is no capacity limit on each delivery batch, and the cost per batch delivery is fixed and independent of the number of jobs in the batch. The objective is to find the optimal size and location of the window, the optimal dispatch date for each job, as well as an optimal job sequence to minimize a cost function based on earliness, tardiness, holding time, window location, window size, and batch delivery. We show that the problem can be optimally solved in O(n8)O(n8) time by a dynamic programming algorithm under a reasonable assumption on the relationships among the cost parameters. A computational experiment is also conducted to evaluate the performance of the proposed algorithm. We also show that some special cases of the problem can be optimally solved by lower order algorithms.  相似文献   
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