• Journal of Advanced Information Technology and Convergence
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• v.10 no.2
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• pp.15-31
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• 2020

Various websites have been created due to the increased use of the Internet, and the number of documents distributed through these websites has increased proportionally. However, it is not easy to collect newly updated documents rapidly. Web crawling methods have been used to continuously collect and manage new documents, whereas existing crawling systems applying a single node demonstrate limited performances. Furthermore, crawlers applying distribution methods exhibit a problem related to effective node management for crawling. This study proposes an efficient distributed crawler through stepwise crawling node allocation, which identifies websites' properties and establishes crawling policies based on the properties identified to collect a large number of documents from multiple websites. The proposed crawler can calculate the number of documents included in a website, compare data collection time and the amount of data collected based on the number of nodes allocated to a specific website by repeatedly visiting the website, and automatically allocate the optimal number of nodes to each website for crawling. An experiment is conducted where the proposed and single-node methods are applied to 12 different websites; the experimental result indicates that the proposed crawler's data collection time decreased significantly compared with that of a single node crawler. This result is obtained because the proposed crawler applied data collection policies according to websites. Besides, it is confirmed that the work rate of the proposed model increased.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.442-443
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• 2012

This study propose a sea water heat exchanger for floating architectures, which can be used as heat source or heat sink of heat pump. Based on CFD(Computational Fluid Dynamics), experimental mock-up system is made and tested. Some evaluation performances are shown on this paper.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.1
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• pp.93-97
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• 2023

A triboelectric nanogenerator (TENG) is a device that converts mechanical energy into electrical energy, and has been considered as a substitute for continuous power supply due to its high performance, simple structure and eco-friendliness. Recently, it is important to develop a TENG using a non-toxic material in order to use it as a power source for wearable, attachable, and body-embeddable electronics. Here, we developed a human friendly TENG using polyvinyl chloride (PVC) gel containing acetyl tributyl citrate (ATBC), a non-toxic plasticizer. PVC gels were fabricated using various ratios of PVC and ATBC, and optimized by investigating dielectric properties, surface potential, output performance, and durability. The PVC gel based TENG generates output signals of 73 V and 4.3 μA, i.e., a 5-fold enhancement in the output power compared to pristine PVC-based TENG. In addition, the PVC gel can be stretched over 500% of strain. This study is expected to be helpful in the future development of non-toxic wearable TENG.

• Journal of the Korean Electrochemical Society
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• v.24 no.3
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• pp.65-75
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• 2021

Coin cell is a basic testing platform for battery research, discovering new materials and concepts, and contributing to fundamental research on next-generation batteries. Li metal batteries (LMBs) are promising since a high energy density (~500 Wh kg^-1) is deliverable far beyond Li-ion. However, Li dendrite-triggered volume fluctuation and high surface cause severe deterioration of performance. Given that such drawbacks are strongly dependent on the cell parameters and structure, such as the amount of electrolyte, Li thickness, and internal pressure, reliable Li metal coin cell testing is challenging. For the LMB-specialized coin cell testing platform, this study suggests the optimal coin cell structure that secures performance and reproducibility of LMBs under stringent conditions, such as lean electrolyte, high mass loading of NMC cathode, and thinner Li use. By controlling the cathode/anode (C/A) area ratio closer to 1.0, the inactive space was minimized, mitigating the cell degradation. The quantification and imaging of inner cell pressure elucidated that the uniformity of the pressure is a crucial matter to improving performance reliability. The LMB coin cells exhibit better cycling retention and reproducibility under higher (0.6 MPa → 2.13 MPa) and uniform (standard deviation: 0.43 → 0.16) stack pressure through the changes in internal parts and introducing a flexible polymer (PDMS) film.

• Journal of Biomedical Engineering Research
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• v.32 no.4
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• pp.289-294
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• 2011

Laboratory class is an integral part of biomedical engineering education. Current biomedical engineering curriculum in Korea mostly includes mandatory laboratory classes. Most of the Korean biomedical laboratory classes focus on electrical engineering aspects, while molecular/biological engineering aspects are neglected. Many leading universities in U.S.A. offer a more balanced laboratory class where both electrical engineering aspects and molecular/biological engineering aspects are considered. As a part of an effort to enhance undergraduate biomedical engineering education, a new biomedical engineering laboratory class is proposed to offer a more balanced laboratory learning experience.

• Journal of Practical Engineering Education
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• v.11 no.1
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• pp.75-86
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• 2019

Globally, the change in higher education is gradually moving toward a trend that seeks a change in innovative higher education through the revitalization of digital-based education. Accordingly, this study designed a customized education model based on e-learning that can be used in undergraduate education and development of lifelong vocational skills. The use of online learning platforms and the expansion of education are major factors that change the overall higher education system as the form and content of curriculum changes around the world. In order to establish a customized education model using online learning platform, this study analyzed major overseas advanced education cases and selected the basic direction of customized learning as personalized learning, competency based learning, and training for talents leading the 4th Industrial Revolution. Then, FGI was conducted for undergraduate and lifelong vocational ability development experts. As a result, a customized education model using an online learning platform was derived from a degree-type model available in undergraduate education and a non-degree-type model available in the field of lifelong vocational ability development, and each operation strategy was suggested.

• Journal of Engineering Education Research
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• v.14 no.6
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• pp.60-66
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• 2011

The curriculum system and documentation for advanced general education, MSC (Mathematics, Basic Science, Computer Science), and engineering-design courses have been developed to improve the education of advanced undergraduate students in engineering and technology at Chosun University. In this paper, to obtain improved quality of engineering courses, we systemized the education of engineering and technology, which could be designed as the education satisfying students and provide awards for high-quality performance, through efficient management of education courses and establishment of basic and professional courses. In addition, by applying evaluation to the engineering courses and using the model of continuous quality improvement, we could achieve a high-quality education system for the engineering and technology courses.

• Industrial Engineering and Management Systems
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• v.9 no.1
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• pp.60-68
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• 2010

In this paper, a systematic methodology is proposed for developing an outcome-based undergraduate Industrial and Systems Engineering Program at the Systems Engineering Department of King Fahd University of Petroleum & Minerals (KFUPM) in Saudi Arabia. This program is an upgrade of the Industrial Engineering and Operations Research (IE/OR) option, which has been in existence since 1984 and has been revised several times since then. The methodology and process used is motivated by the Accreditation Board for Engineering and Technology (ABET) 2000 criteria and has been employed to develop the program's objectives and outcomes. Subsequently, a curriculum is designed that is expected to deliver the objectives and outcomes. The paper presents the methodology, objectives, outcomes and the developed curriculum of the outcome-based program.

• The Journal of Korean Institute for Practical Engineering Education
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• v.3 no.2
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• pp.136-141
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• 2011

The current tendency on development and change of equipment system in the factory are overlapped with the specific field of the existing systems such as PLC, DCS and SCADA, and the limited portion of the systems in the specific field stands in their own field. Specially, systematic integration, inspection control system and manufacturing management system, management information system are getting closely linked and therefore we increasingly need the open system. Meeting the needs, manufacturing automated equipments in the factory overcoming the shortcomings of unlinked unit equipment recently are getting changed to the phase closely linking with other systems. The training systems for the university, however, have not kept up with the needs from the industry, in spite that fused complex function and performance are asked in the field. To solve the problems, we suggest that the training courses and the equipment designed for the undergraduate education.

• Journal of Engineering Education Research
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• v.23 no.5
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• pp.76-85
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• 2020

The purpose of this study was to develop and validate a measurement scale of core competencies for one Institute of Science & Technology's students in South Korea. Based on the school's core value and mission, items were developed through document analysis, faculty survey, and experts' review. Initial sets of items were administered to students and results were analyzed to finalize the items for the scale, which consists of 4 core competencies (Creativity, Challenge, Collaboration, and Care) and 12 sub-competencies. Through reliability analysis and exploratory factor analysis, 56 items were selected. For a validity test, confirmatory factor analysis was conducted. Results suggest that the measurement scale is reliable and valid in measuring core competencies of students in an Institute of Science & Technology.