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881.
In an advertising strategy, it is preferable to optimize a sequence of periodic decisions, rather than optimizing each period's decision separately. Thus, a dynamic technique such as optimal control, which is used in this study, should be employed. Necessary conditions, as inferred from a parsimonious advertising model, are tested using data from the tobacco industry. Parameter estimation involves the use of non-linear regression. The estimates permit trajectories of optimal advertising expenditures and optimal market shares to be constructed for filter cigarettes. When compared with the actual trajectories, the optimizing trajectories exhibit a striking correspondence to reality. Therefore, interesting results can be obtained using a simple model, provided the optimizing method takes into account the dynamic nature of managerial decision-making and provided powerful methods for estimating model parameters are used.  相似文献   
882.
The distinction between ill-structured and well-structured decision problems is extended in this paper to include the degree of familiarity that a decision maker has with the initial state of the problem, its desired state, and appropriate transformations for resolving the problem. It is shown that problem ill-structuredness may result from inadequate information regarding any of these components and that the nature of problem ill-structuredness has important implications for problem formulation and solution. A decision tree is presented which represents strategies for either reformulating primary problems of each class of ill-structuredness to a more readily solved form, or solving the problem as initially formulated.  相似文献   
883.
Ronald Schettkat 《LABOUR》1992,6(1):121-140
Abstract. The paper briefly investigates theoretical arguments for mismatch unemployment; it presents a vacancy-unemployment curve for Germany and investigates various reasons for outward shifts of the curve. Both variables, unemployment and vacancies, are decomposed into flows and duration to identify the underlying processes of these shifts. The analysis of the components with the help of change-duration curves shows adverse trends for unemployment and vacancies over the business cycles. Unemployment duration has increased while vacancy duration has decreased. Mismatch in the labour market can therefore hardly be blamed to have been an obstacle for economic expansion in the German economy during the 1980s. Persistently high unemployment in Germany has to be interpreted as a hysteresis process which was driven by macroeconomic policies, increasing labour supply and restructuring imbedded in the German institutional framework.  相似文献   
884.
Past research suggests that problem solving and/or decision behavior can be altered and improved by the changes in the way information is accessed and displayed. Also, researchers have found that the usefulness of different information display formats are contingent on the characteristics of the problem task. This research investigated the impact on problem solving when accessing and using information from linear and nonlinear systems. Also, the research investigated problem-solving performance of linear and nonlinear systems when applied to different combinations of problem tasks. In a laboratory setting, linear and nonlinear systems were developed to conduct this experiment. This experiment used 64 graduate business students in a two-factor repeated-measures design employing a multivariate analysis of variance to analyze the data. Repeated measures were conducted to analyze the experimental group under both linear and nonlinear treatments. The findings from the study support the notion that the nonlinear system resulted in superior problem solving and higher levels of user satisfaction than the linear system. Specifically, the nonlinear system enabled users to make faster and more accurate decisions on perceptual problem tasks than did the linear system. For analytical problem tasks, users performed faster with the nonlinear system; however, there was no significant difference in accuracy. User satisfaction was higher with the nonlinear system under both perceptual and analytical tasks.  相似文献   
885.
886.
This article applies the concepts of alpha, beta, and gamma changes to test whether the implementation of a new office information system with networking capabilities changes the way organizational members conceptualize office work. The traditional approach (t-test) was used to measure alpha change and indicated little change in how effectively the respondents felt they performed eight generic office activities before implementation (T1) and nine months after implementation (T2). However, considerable change was detected between effectiveness reported at T1 and a retrospective assessment of T1 effectiveness reported at T2 (called “then” assessments). Strong change was also detected between “then” assessments and T2 effectiveness reported at T2, indicating beta change. Multiple hierarchical tests showed that most of the change was actually gamma change; the T2 and the “then” factor structures and covariances differed significantly. This study supports propositions that using computers to accomplish organizational work may be associated with different conceptualizations of work, which may create ambiguity and uncertainty if training and management policies do not respond appropriately. Finally, this study provides an expanded version of a prior solution to detecting alpha, beta, and gamma changes.  相似文献   
887.
888.
The audit staff planning problem, a specific type of manpower planning problem, has been modeled using goal programming and, more recently, multiple objective linear programming. Prior studies developed single-period models and did not go beyond the model building stage. This study develops a multiperiod audit staff planning model and evaluates the model using a test application involving actual decision makers (partners in public accounting firms). The multiperiod model includes seven objectives to be optimized: profit (to be maximized), late completion of work, work declined, staff augmentation, staff reduction, underutilization of the work force, and shortfall in meeting professional development targets (all to be minimized). Over a four-quarter planning horizon with one “busy season,” the model is subject to constraints with respect to the projected audit work load, ability to substitute personnel and to perform interim audit work, available staff hours (including overtime limitations), supervisory requirements, and professional development targets. Results of the test application showed that the model was capable of producing a range of values for each objective. The participants were exposed to much of that range when making their decisions. The results also showed that all objectives were important and that participants were consistent in choosing their preferred level of each objective over several runs of the model. These results and the reactions of the participants demonstrate that the model is usable by actual decision makers and has potential for a number of specific applications.  相似文献   
889.
This paper describes the use of multiattribute decision making by the U.S. Coast Guard when choosing the most appropriate auxiliary device to use on an icebreaker. Five different missions of icebreakers are defined, and the objectives and attributes that describe the effectiveness of each auxiliary device in accomplishing these missions are established. For each geographical area of interest, the missions are weighted using the analytical hierarchy process. Also, group utilities are developed for attribute vectors in order to incorporate the judgments of different icebreaker operators.  相似文献   
890.
Mixed model repeated measures (MMRM) is the most common analysis approach used in clinical trials for Alzheimer's disease and other progressive diseases measured with continuous outcomes over time. The model treats time as a categorical variable, which allows an unconstrained estimate of the mean for each study visit in each randomized group. Categorizing time in this way can be problematic when assessments occur off-schedule, as including off-schedule visits can induce bias, and excluding them ignores valuable information and violates the intention to treat principle. This problem has been exacerbated by clinical trial visits which have been delayed due to the COVID19 pandemic. As an alternative to MMRM, we propose a constrained longitudinal data analysis with natural cubic splines that treats time as continuous and uses test version effects to model the mean over time. Compared to categorical-time models like MMRM and models that assume a proportional treatment effect, the spline model is shown to be more parsimonious and precise in real clinical trial datasets, and has better power and Type I error in a variety of simulation scenarios.  相似文献   
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