• 한국공간구조학회논문집
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• 제19권4호
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• pp.85-94
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• 2019

Then 3D printing is used practically at construction sites, there is a serious lack of studies on the conflict with construction-related laws and expected operational problems. Accordingly, the purpose of this study is to present obstacles and directions for improvement in construction-related laws (Building Act, Construction Technology Promotion Act, Housing Act, Construction Machinery Management Act, etc.) for practical operation of 3D printing. The important results are as follows. Amending existing construction-related laws for 3D printing is irrational and inefficient in terms of structure and material. This study proposed a method of satisfying performance required by laws or standards based on the performance design method presented in existing laws and systems through structure and material performance certification procedure. In addition, inclusion of 3D printing equipment in the Construction Machinery Management Act results in various restrictions such as equipment inspection and certification of machine parts. As such restrictions can block vitalization of 3D printing, a long-term and step-wise approach was suggested.

• Advances in concrete construction
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• 제2권2호
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• pp.91-108
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• 2014

This paper presents a nonlinear finite element analysis (FEA) in order to investigate the flexural performance of one-way slabs strengthened by epoxy-bonded steel plates. Four point loading scheme is selectively chosen. A model is developed to implement the material constitutive relationships and non-linearity. Five Slabs were modeled in FEM software using ABAQUS. One slab was unstrengthened control slab and the others were strengthened with steel plates with varying the plate thickness and configuration. In order to verify the accuracy of the numerical model, a comparison was done between the experimental results available in the literature and the proposed equations by ACI 318-11 for the calculation of ultimate load capacities of strengthened slabs, the agreement has proven to be good and FEA attained accurate results compared with ACI code. A parametric study was also carried out to investigate the influence of thickness of steel plate, strength of epoxy layer and type of strengthening plate on the performance of plated slabs. Also, the practical and technical feasibility of splitting the steel plate in strengthening process has been taken into account. For practical use, the author recommended to use bonded steel plate as one unit rather than splitting it to parts, because this saves more effort and reduces the risk of execution errors as in the case of multiple bonded parts. Both techniques have nearly the same effect upon the performance of strengthened slabs.

• 디지털산업정보학회논문지
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• 제12권4호
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• pp.59-69
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• 2016

We proposed a specialized model of performance measurement to measure the training performance of the trainees in cyber practical training. Cyber security professionals are cultivating their expertise, skills, and competencies through cyber practical training in specialized education and training institutions. The our proposed process of trainee evaluation is consisted of an evaluation component discovery, evaluation item selection, evaluation index catalog, ratings and criteria decision, and calculation formula. The trainee evaluation is consisted of a formative evaluation during the training and an overall evaluation after finished training. Formative evaluation includes progress evaluation and participation evaluation, and overall evaluation includes practice evaluation and learning evaluation. The evaluation is weighted according to the importance of evaluation type. Because it is evaluated actual skills and abilities, competencies are assigned a high weight, while knowledge and attitudes are assigned a low weight. If cyber security trainees are evaluated by the proposed evaluation model, cyber security professionals can be cultivated by each skill and knowledge level and can be deployed by importance of security task.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권3호
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• pp.523-541
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• 2011

In current IEEE 802.11 wireless LAN, every unicast transmission requires an ACK from the receiver for reliability, though it consumes energy and bandwidth. There have been studies to remove or reduce ACK overhead, especially for energy efficiency. However none of them are practically used now. This paper introduces a noble method of selective unacknowledged transmission, where skipping an ACK is dynamically decided frame by frame. Utilizing the fact that a multicast frame is transmitted without accompanying an ACK in 802.11, the basic unacknowledged transmission is achieved simply by transforming the destination address of a frame to a multicast address. Since removing ACK is inherently more efficient but less strict, its practical profit is dependent on traffic characteristics of a frame as well as network error conditions. To figure out the selective conditions, energy and performance implications of unacknowledged transmission have been explored. Extensive experiments show that energy consumption is almost always reduced, but performance may be dropped especially when TCP exchanges long data with a long distance node through a poor wireless link. An experiment with a well-known traffic model shows that selective unacknowledged transmission gives energy saving with comparable performance.

• 공학교육연구
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• 제23권2호
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• pp.49-60
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• 2020

The purpose of this study is to empirically verify whether there are differences according to group characteristics in the effect of job characteristic requirements on practice performance in university long-term on-site training. Specifically, the relationship between job characteristics (job scope, job content, coaching, benefits), practical satisfaction, and occupational competencies was examined according to the group characteristics (gender types, major types, corporation types). For this purpose, the survey data were collected and analyzed for 752 students who participated in K university long-term on-site training. As a result of the analysis, first, it was found that the job characteristics (job scope job content, coaching, benefits) had structural relationship affecting occupational competence through mediation of practice satisfaction. Second, As for the differences according to the group characteristics, there were differences in the relations. Based on the result, theoretical and practical implications and follow-up studies were proposed.

• Journal of Information Science Theory and Practice
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• 제8권2호
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• pp.55-67
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• 2020

Webometric research in the Russian library sector is just beginning to gain momentum. This article examines the experience of webometric research in libraries from the perspective of the global practice. In particular, it highlights a number of foreign works, which may have a special practical value for Russian libraries, and emphasizes important webometrics areas for libraries. The purpose of this study is to research the practical application of key performance indicators (KPIs) abroad and conduct a webometric analysis of the websites of some leading Siberian and Far Eastern scientific libraries based on selected KPIs. The study data were collected with SimilarWeb and other analytical tools. The study revealed that key traffic metrics are the basis of webometric research, and identified available promising groundwork for the purpose of their further testing. The shortcomings in the current state of the websites of the Siberian and Far Eastern scientific libraries were noted. Based on the obtained webometric traffic indicators, the ranking of the Siberian and Far Eastern scientific libraries was made.

• 아태비즈니스연구
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• 제6권1호
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• pp.59-82
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• 2015

According to the survey on the state of practical usage and present situation of FTAs, conducted among trade companies operating in Shandong province in 2014, more than 90% of companies are believed to be small and medium sized enterprises. Therefore this study tries to test what impact the awareness and utilization of an FTA have on its outcome among trade companies operating in Shandong province as well as partner countries and other trade companies. The research results are as follows. First, we found a positive correlation between 1) a company's global orientation (as measured in export density as a percentage of profit) and 2) its competitiveness (as measured in annual sales), and a company's degree of utilization of FTA provisions. Second, One of the findings is that the more aware of the (exporting) HS code, conventional tariffs and the process of issuing C/O the companies from Shandong province are the more they actually use (utilize) an FTA inpractice. Another interesting finding is that the more aware of the (exporting) HS code and conventional tariffs the enterprises are the higher is their practical usage level of an FTA. Third, however, at the time of this study's completion, FTA utilization was not yet positively correlated with statistically significant performance results. Therefore, to increase the utilization and performance of FTA, the China government have to make a efficient business models for each industry and support the small and mid-size businesses including Shandong province's SMEs.

• 전력전자학회논문지
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• 제26권2호
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• pp.127-134
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• 2021

This study presents an overhang-type rail traction system using dual brushless AC (BLAC) motors with hall sensors. For an accurate position and moving length control of the designed rail traction system, instantaneous position controller using speed reference model and modified disturbance observer for BLAC motor with hall sensor are proposed. The presented speed reference model is designed to satisfy the required performance of 200 mm/s with proper acceleration and deceleration slopes to reduce mechanical vibration. Through the instantaneous speed reference model, instantaneous position and speed errors can be compensated together. Furthermore, the modified disturbance observer for BLAC motors with low-resolution hall sensors can improve the torque and speed control performance. The proposed disturbance observer is based on an actual motor speed. However, the feedback speed information of the hall sensor is not enough for use in the low-speed region. The practical adopted disturbance observer uses an activation speed band to the actual torque controller of the designed rail traction system. The proposed position control scheme is verified by the MATLAB-Simulink model and a practical manufactured traction system. In the computer simulation and experiments, the proposed position control scheme shows advanced control performance.

• 융합경영연구
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• 제9권5호
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• pp.15-25
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• 2021

Purpose: In the Korean railway infrastructure process, contractors and operators are involved at a later stage, which results in significant inefficiency. This study examines the benefits of early stakeholder involvement in Korean railway infrastructure projects and provides practical guidelines. Design, data and methodology: Literatures and foreign cases are analyzed. Building on the new product development model, we derive propositions explaining the relationship between early stakeholder involvement and the performance of Korean railway infrastructure project. Results: Major propositions include that early involvement of contractor has a positive effect on the project performance by shortening the infrastructure construction period and that early involvement of railway operator has a positive effect on the project performance by improving the effectiveness of railway infrastructure. Four requirements for the success of early stakeholder involvement are addressed. Conclusions: This study suggests that early stakeholder involvement shortens the construction period and improves railway infrastructure effectiveness. Academic contribution is to present the framework on railway infrastructure projects as holistic interactions among stakeholders. Practical contribution is to provide railway policy makers and other business practitioners with policy guidelines to improve railway infrastructure project process and to recommend an open access to relevant data.

• Educational Technology International
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• 제11권1호
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• pp.47-68
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• 2010

The purpose of this study was to analyze majors trends and issues of e-Learning curriculum for human resource development in the corporate context. The e-Learning curriculum was chosen as the subject of research consists of 2,710 lectures that were given from 2007 to July 2009 for the recent three years by providing at Ministry of Labor and Korea Research Institute for Vocational Education & Training. In order to investigate trends and issues, it was employed theme analysis which is one of the types of document analysis that approach a qualitative research methodology. As a result of this research, 7 major trends and issues in e-Learning curriculum for HRD in the field of corporate education were drawn; ① Strengthening expertise through learning of job related professional knowledge, ② Cultivation of common & essential knowledge for a job to increase work performance efficiency ③ Organizational management strategy for improving performance, ④ Organizational management and operational strategy for actively responding to environmental changes, ⑤ Leadership as a strategy for cultivating core personnel and field-centered practical leadership. ⑥ Creating a happy workplace through the work-life balance, ⑦ Strengthening global communication skill. Based on these analysis, practicals and theoretical implications of e-Learning professionals and HR researchers for HRD were suggested.