1,720,960 research outputs found
Improving service qualities of cyclic line plans considering heterogeneous passenger origin-destination (OD) flow groups
No full textCyclic train services provide huge conveniences to passengers. This work aims to fix one vital promise in major line planning studies that passengers were homogeneous. In fact, passengers’ rail travel expectations are heterogeneous. But those heterogeneities show common needs correlating with travel distances and defined station levels. Therefore, we cluster passenger heterogeneities into divided OD groups, extend service qualities,and add more train line factors to our line planning model. Cyclic line plan from this joint optimisation not only receives service quality improvements but also provides multiple train service types to match clustered OD groups. Moreover, we allow passengers to be served by different train service types, deliver a high level of direct services, and maintain the minimum operation cost. We compare concluded line plans with the results of the generic line planning model and the real-world line plan to show our solution advantages
How to optimize train lines for diverse passenger demands: a line planning approach providing matched train services for each O-D market
No full textLine planning decides critical service contents of a passenger railway schedule. In real-world scenarios, passengers’ travel expectations or preferences on service qualities tend to be heterogeneous among different origin–destination (O-D) pairs or even in the same O-D pair, which requires railway operators to schedule train services catering to those diverse passenger demands. However, previous line planning approaches either treated passengers homogeneously or roughly divided simple passenger groups by travel purposes or service types. In this paper, we view each passenger O-D pair as an individual O-D market and propose a line planning approach where concluded train lines can deliver matched service levels of trains for each O-D market. Based on the Set Covering Problem (SCP), we establish a novel bi-objective mixed integer linear programming (MILP) model that considers the benefits of both railway operators and passengers. Multiple service qualities for each passenger O-D pair, such as travel speed, direct or transfer connection, frequency, price, etc. are seen as the objects to be “covered” by train lines, to achieve a more accurate supply–demand match. Facing the potential conflicts between diverse passenger demands and limited railway supply, we formulate a series of non-rigid constraints (NRC) to achieve a non-rigid supply–demand match i.e., each O-D pair’s demands can be either guaranteed to be satisfied or satisfied as much as possible. In this manner, railway operators can testify different marketing policies and make marketing decisions regarding which O-D markets should improve, maintain, or degrade services. A heuristic rule-based adaptive iterative searching approach (ISA) is designed to solve large-scale model structures. We take the Beijing-Shanghai high-speed railway (HSR) line as the case study background. We comparatively evaluate the operation and service performances of multiple cyclic line plan scenarios, discuss the performance difference, and state our policy implication. We also recalibrate the service levels of the real-world non-cyclic line plan. The experiment results show that our proposed approach can efficiently help design the line plans based on customized marketing policies and improve the service levels of the real-world line plan
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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