• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.11
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• pp.928-936
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• 2003

In the present study, feasibility investigation on the solar assisted hot water supply system for apartment houses was carried out by the review of service facility and heat load pattern. Also analysis and experiment of the small sized system model were performed. This hybrid system are consists of solar collector, heat storage tank, controller, and gas boiler using LPG as a secondary heat source. The analytical results showed a good agreement with experimental data. We found that this hybrid system could reduce the energy cost by 30% for hot water compared to typical boiler system in the apartment houses. Also we showed that this model could be used for the energy and economic analysis of the hybrid system.

• Journal of Magnetics
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• v.18 no.1
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• pp.65-73
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• 2013

In this paper, design and performance analysis of robust and inexpensive permanent magnet-assisted synchronous reluctance generators (PMa-SynRG) for tactical and commercial generator sets is studied. More specifically, the optimal design approach is investigated for minimizing volume and maximizing performance for the portable generator. In order to find optimized PMa-SynRG, stator winding configurations and rotor structures are analyzed using the lumped parameter model (LPM). After comparisons of stator windings and rotor structure by LPM, the selected stator winding and rotor structure are optimized using a differential evolution strategy (DES). Finally, output performances are verified by finite element analysis (FEA) and experimental tests. This design process is developed for the optimized design of PMa-SynRG to achieve minimum magnet and machine volume as well as maximum efficiency simultaneously.

• Transactions of Materials Processing
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• v.31 no.6
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• pp.337-343
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• 2022

Electrically assisted pressure joining (EAPJ) utilizes electric current-induced kinetic enhancement to achieve solid state diffusion bonding within a short time. In this study, aluminum alloy specimens, which are known as a hard-to-weld metal, were successfully solid-state joined through EAPJ. The bonding process was performed in two ways: continuous direct current (CDC), which applies relatively low current density, and pulsed direct current (PDC), which applies high current density. It was observed that the bonding strength was higher in PDC than in CDC. The microstructure of the joint was characterized using 3D X-ray microscopy (XRM) and electron backscatter diffraction (EBSD).

• Journal of Animal Science and Technology
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• v.63 no.6
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• pp.1443-1452
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• 2021

This study aimed to investigate the effects of the multimodal group intervention that combined animal-assisted therapy (AAT) and integrated play therapy (IPT) on depression and self-esteem in undergraduate university students. The subjects were 40 students attending animal-related and social welfare departments of universities located in a metropolitan city. The multimodal intervention program was conducted for eight sessions (twice a week, 60 min each) in the experimental group. Data analysis was conducted using the independent sample t-test, ANCOVA, and paired sample t-test for pre- and post-test. Therefore, the multimodal intervention program applying AAT and IPT showed positive effects on depression and self-esteem in university students. Based on these results, this study proposed the operation of multidisciplinary education and practical and policy utilization methods to reduce depression among university students and help improve their self-esteem.

• BMB Reports
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• v.54 no.7
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• pp.356-367
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• 2021

Cell-based therapy is a promising approach in the field of regenerative medicine. As cells are formed into spheroids, their survival, functions, and engraftment in the transplanted site are significantly improved compared to single cell transplantation. To improve the therapeutic effect of cell spheroids even further, various biomaterials (e.g., nano- or microparticles, fibers, and hydrogels) have been developed for spheroid engineering. These biomaterials not only can control the overall spheroid formation (e.g., size, shape, aggregation speed, and degree of compaction), but also can regulate cell-to-cell and cell-to-matrix interactions in spheroids. Therefore, cell spheroids in synergy with biomaterials have recently emerged for cell-based regenerative therapy. Biomaterials-assisted spheroid engineering has been extensively studied for regeneration of bone or/and cartilage defects, critical limb ischemia, and myocardial infarction. Furthermore, it has been expanded to pancreas islets and hair follicle transplantation. This paper comprehensively reviews biomaterials-assisted spheroid engineering for regenerative therapy.

• Food Engineering Progress
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• v.13 no.1
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• pp.32-37
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• 2009

Central composite design was applied for the ultrasound-assisted extraction from peel and seed of Campbell Early grapes and the extraction processes were optimized for the antiradical activities of the extracts by using response surface methodology. Optimal conditions were 53.45% of ethanol concentration, 45.99${^{\circ}C}$ of extraction temperature and 23.93 min of extraction time for the maximum antiradical activity of grape peel extract (54.98%) and 53.14% of ethanol 56.03${^{\circ}C}$ of temperature and 29.03 min of time for maximum antiradical activity of grape seed extract (90.60%).

• Transactions of Materials Processing
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• v.28 no.3
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• pp.130-134
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• 2019

Electrically assisted (EA) springback reduction of grade 2 titanium alloys is demonstrated through u-bending experiments. A single pulse of electric current having a short duration of less than 0.5 sec is applied to a specimen during u-bending. The effect of the electric current condition on the resultant springback is then evaluated. The experimental result shows that the springback of the selected grade 2 titanium alloy could almost be eliminated through application of electric current with a duration less than 0.5 sec prior to unloading. Lastly, an exemplary industrial application of EA springback control is presented.

• Electronics and Telecommunications Trends
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• v.33 no.6
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• pp.50-57
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• 2018

As devices have evolved, traditional flip chip bonding and recently commercialized thermocompression bonding techniques have been limited. Laser-assisted bonding is attracting attention as a technology that satisfies both the requirements of mass production and the yield enhancement of advanced packaging interconnections, which are weak points of these bonding technologies. The laser-assisted bonding technique can be applied not only to a two-dimensional bonding but also to a three-dimensional stacked structure, and can be applied to various types of device bonding such as electronic devices; display devices, e.g., LEDs; and sensors.

• Journal of Chest Surgery
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• v.52 no.1
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• pp.55-57
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• 2019

Robotically assisted mitral valve repair has proven its efficacy during the last decade. The most suitable approach for patients with difficult anatomies, such as morbid obesity, sternal deformities, cardiac rotation, or vascular anomalies, represents a current challenge in cardiac surgery. Herein, we present the case of a 71-year-old patient affected by severe degenerative mitral valve regurgitation with pectus excavatum and a right aortic arch with an anomalous course of the left subclavian artery who was successfully treated using a Da Vinci-assisted approach.

• International Journal of Contents
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• v.15 no.3
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• pp.39-46
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• 2019

This study aimed to develop a peer-assisted learning (PAL) program for use in a core nursing skills education course and to investigate the effects of the education program on three key outcomes. A comparative study was conducted through the division of students of a core nursing skills education program into a treatment group and control group. After the programs, self-efficacy, confidence and satisfaction were compared between the groups. The comparison of these three factors indicated that the related scores were significantly higher in the treatment group receiving the education program with the PAL method than those of the control group receiving traditional education. We concluded that self-efficacy gave the nursing students the confidence that they could successfully perform their tasks and motivation to learn. Education programs using the PAL method are suggested as an effective method for the acquisition of skills among nursing students.