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11.
Scheduling university examinations is often done with the objective of spreading a student's required examinations over an examination week. That is the equivalent of the problem of minimizing the number of examinations a student must take on any one day. An approach to scheduling exams which relates the problem to the classical assignment problem is discussed. The model developed is a symmetry-constrained assignment model, and the solution method requires use of a branch-and-bound algorithm. Results from application of the algorithm to six semesters of actual data are presented.  相似文献   
12.
Upper extremity musculoskeletal symptoms and disorders are common in the working population. The economic and social impact of such disorders is considerable. Long-time, dynamic repetitive exposure of the hand-arm system during manual handling operations (MHO) alone or in combination with static and postural effort are recognised as causes of musculoskeletal symptoms and disorders. The assessment of these manual work tasks is crucial to estimate health risks of exposed employees. For these work tasks, a new method for the assessment of the working conditions was developed and a validation study was performed. The results suggest satisfying criterion validity and moderate objectivity of the KIM-MHO draft 2007. The method was modified and evaluated again. It is planned to release a new version of KIM-MHO in spring 2012.  相似文献   
13.
ABSTRACT

This paper outlines the notion of ‘algorithmic technique’ as a middle ground between concrete, implemented algorithms and the broader study and theorization of software. Algorithmic techniques specify principles and methods for doing things in the medium of software and they thus constitute units of knowledge and expertise in the domain of software making. I suggest that algorithmic techniques are a suitable object of study for the humanities and social science since they capture the central technical principles behind actual software, but can generally be described in accessible language. To make my case, I focus on the field of information ordering and, first, discuss the wider historical trajectory of formal or ‘mechanical’ reasoning applied to matters of commerce and government before, second, moving to the investigation of a particular algorithmic technique, the Bayes classifier. This technique is explicated through a reading of the original work of M. E. Maron in the early 1960 and presented as a means to subject empirical, ‘datafied’ reality to an interested reading that confers meaning to each variable in relation to an operational goal. After a discussion of the Bayes classifier in relation to the question of power, the paper concludes by coming back to its initial motive and argues for increased attention to algorithmic techniques in the study of software.  相似文献   
14.
In many clinical research applications the time to occurrence of one event of interest, that may be obscured by another??so called competing??event, is investigated. Specific interventions can only have an effect on the endpoint they address or research questions might focus on risk factors for a certain outcome. Different approaches for the analysis of time-to-event data in the presence of competing risks were introduced in the last decades including some new methodologies, which are not yet frequently used in the analysis of competing risks data. Cause-specific hazard regression, subdistribution hazard regression, mixture models, vertical modelling and the analysis of time-to-event data based on pseudo-observations are described in this article and are applied to a dataset of a cohort study intended to establish risk stratification for cardiac death after myocardial infarction. Data analysts are encouraged to use the appropriate methods for their specific research questions by comparing different regression approaches in the competing risks setting regarding assumptions, methodology and interpretation of the results. Notes on application of the mentioned methods using the statistical software R are presented and extensions to the presented standard methods proposed in statistical literature are mentioned.  相似文献   
15.
Our study explores the adoption of Facebook and Twitter by candidates in the 2013 German Federal elections. Utilizing data from the German Longitudinal Election Study candidate survey fused with data gathered on the Twitter and Facebook use of candidates, we draw a clear distinction between Facebook and Twitter. We show that adoption of both channels is primarily driven by two factors: party and money. But the impact of each plays out differently for Facebook and Twitter. While the influence of money is homogenous for Facebook and Twitter with the more resources candidates have, the more likely they are to adopt, the effect is stronger for Facebook. Conversely, a party’s impact on adoption is heterogeneous across channels, a pattern we suggest is driven by the different audiences Facebook and Twitter attract. We also find candidates’ personality traits only correlate with Twitter adoption, but their impact is minimal. Our findings demonstrate that social media adoption by politicians is far from homogenous, and that there is a need to differentiate social media channels from one another when exploring motivations for their use.  相似文献   
16.
从"灰色文献"的定义、发展概况,以及"灰色文献"的种类及其作用等方面分别阐述了"灰色文献"作为一种信息资源的重要性.  相似文献   
17.
This paper reviews global and multiple tests for the combination ofn hypotheses using the orderedp-values of then individual tests. In 1987, Röhmel and Streitberg presented a general method to construct global level α tests based on orderedp-values when there exists no prior knowledge regarding the joint distribution of the corresponding test statistics. In the case of independent test statistics, construction of global tests is available by means of recursive formulae presented by Bicher (1989), Kornatz (1994) and Finner and Roters (1994). Multiple test procedures can be developed by applying the closed test principle using these global tests as building blocks. Liu (1996) proposed representing closed tests by means of “critical matrices” which contain the critical values of the global tests. Within the framework of these theoretical concepts, well-known global tests and multiple test procedures are classified and the relationships between the different tests are characterised.  相似文献   
18.
Combining management consultation with psychotherapy in the early nineties, coaching is a real innovation. Its success story grounds on a huge market demand. Nevertheless, actual market observations revealed a declining success progress over the past years caused by two factors. The first one refers to economic reasons since coaching is a high-budget-product and focuses mainly on managers and important specialists. The second factor is a psychological one: many potential clients associate coaching with psychotherapy and therefore react with resistance. To continue the progress, it is necessary to overcome both restrictions. The solution is virtual self-coaching as an innovative combination of coaching and e-learning. It is an online-tool that guides the user through a well-defined path of problem solving questions. This is for many users attractive because of the low costs in combination with the fact that working with an online-tool is associated with further education and not therapy. Our tests have demonstrated that the program is useful for a big variety of different problems and that best results can be expected if virtual self-coaching is combined with telephone coaching.  相似文献   
19.
Knowledge Management Systems (KMSs) are becoming part of the agenda in many of today's leading firms. Through in-depth case studies of seven multinational companies (MNCs), examined over a period of four years, we identify four distinctive types of KMS - Fragmented, Content-based, Process-based and Capability-based - and their characteristics. These characteristics include both the structure, dimension and flow of the knowledge itself, and the staffing, training and reward systems in place to support the KMS. Relevant organisational factors influencing KMS design and implementation include the level of resource commitment by the headquarters, the structure of the firm, and the distribution of roles between headquarters and subsidiaries. Key external influences include the degree of environmental change and pressures to follow industry norms in technology investment. Our empirical evidence suggests that while some MNCs adopt the same type of KMS for relatively long periods of time, others transit between different KMS types. Moreover, transitions between types may follow either an increased resource commitment and augmented KMS sophistication, or a decreased resource commitment and reduced KMS complexity. Insights from the strategy-structure-process and change management literatures are utilised to examine these transitions between KMS types. Key lessons for MNC managers are provided in relation to both the initial adoption of a KMS and the handling of transitions between different systems.  相似文献   
20.
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