• Journal of the Korean Society of Systems Engineering
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• v.13 no.1
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• pp.25-31
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• 2017

This paper aims to evaluate the conservatism in the design of APR1400 (Advanced Pressurized water Reactor 1400 designed by KHNP) reactor internals component, the LSS (Lower Support Structure). Re-engineering of the LSS is done based on the system design condition data and applicable ASME code that was used for the original APR1400 design. Systems engineering approach is applied to design the LSS of APR1400 without refering APR1400 LSS dimensional parameters and tries to verify important design parameters of APR1400 LSS as well as the validity of the re-engineering design process as independent verification method of reactor component design. Systems engineering approach applied in this study following V-model approach. The re-engineered LSS design showed more than enough conservatism for static loading case. The maximum deflection of LSS is under 1mm (calculated value is 0.25mm) from 4000 mm diameter of LSS. Hence the deflection can be ignored in other reactor internals for structural integrity assessment. Especially the effect of LSS deflection on fuel assembly can be minimized and which is one of the main requirements of LSS design. It also showed that the maximum stress intensity is 2.36MPa for the allowable stress intensity of 60.1 MPa. The stress resulted from the static load is also very small compared to the maximum allowable stress intensity, hence there is more than enough conservatism in the LSS design.

• The Journal of Korean Institute for Practical Engineering Education
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• v.3 no.2
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• pp.142-146
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• 2011

In this paper, to invigorate elderly-friendly industry, a case study on curriculum for re-educational work of the field engineers is introduced. The curriculum has been developed to retrain technicians and engineers in IT-based elderly-friendly business industry, to help them develop elderly-friendly products, and it have been evolved by operating it and analyzing outcome and satisfaction levels since August in 2009. The re-education work of the field engineers are designed for invigorating the IT-based elderly-friendly business industry, based on the instruction system design(ISD) model. To develop IT-based elderly-friendly products, the elderly-friendly accessible design and the elderly-friendly living and health care equipment design are required. For the elderly-friendly accessible design, it consists of "Elderly-Friendly Engineering Based on Human Characteristics", "Color Sensibility and Universal Design for The Elderly", and "Design Understanding and Process". For the elderly-friendly living and health care equipment design, it consists of "Embedded System Design and Debugging Experiments for Elderly-Friendly IT Equipment", "Elderly-Friendly Android Implementation Design", and "Design and Experiments of Silver-care Android-based Smart Equipment".

• Journal of Fashion Business
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• v.27 no.6
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• pp.147-159
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• 2023

Fashion is the second most polluting industry. We must strive to transition to a form of industry that does not cause environmental pollution. These efforts drive may fashion brands to produce and sell products with redesigned methods that delight the inventory flow. Accordingly, it is necessary to develop creative apparel up-cycling design using the creative thinking method. This study aims to produce clothing redesign works by introducing design idea types for systematic redesign creation. In this research, we conducted a literature review on the concept of up-cycling design and employed heterotopa spacial concept reflected fashion design creation methodology types. The RE;CODE, a leading domestic up-cycling design brand, was used in case analysis. According to the command of shape transformation, it is spreading, stacking, dropping, inverting and crossing, from the creative thinking method reflecting heterotopia spacial concepts, showing designers a concrete way to transform form into new apparel. Seven works of apparel up-cycling design were developed by conducting process of RE;CODE. Also, to establish an apparel up-cycling design creation process for creating works. In this study, we proposed a systematic method for apparel up-cycling design, including a method for reorganizing two or more different materials to create something new and ultimately reversing the structure. The value and significance of this study is that it proposes a systematic method for apparel up-cycling design to make it new.

• Journal of the Korean Society of Clothing and Textiles
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• v.45 no.1
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• pp.106-122
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• 2021

This study confirmed the mechanical properties of an auxetic re-entrant pattern prepared using 3D printing technology and its composite fabric with neoprene for the production of functional auxetic patterns/textiles for safety shoes. Samples were prepared by the tilt angle of a re-entrant pattern of 0°, 30°, 45°, 60° and 90°, and then analyzed using Poisson's ratio, bending, compression, and tensile properties. A 3D printed auxetic re-entrant pattern (3DP-RE) and its composite fabric (3DP-RE/NP) showed a negative Poisson's ratio in all tilting angles that indicated auxetic properties. The results of the bending property shown that strength of 3DP-RE/NP was 1.5 times lower than NP, but the strain improved 2.0 times. It was confirmed that the deformation of 3DP-RE/NP is possible with a low load. Each sample type of compression behavior indicated similar regardless of the tilting angles; in addition, the compression toughness of 3DP-RE/NP increased 1.2 times compared with NP. In the case of tensile properties, 3DP-RE and 3DP-RE/NP were affected by the tilting angle, samples with 90° (the opposite of load direction) showed best tensile property and toughness. 3DP-RE/NP indicated improved bending, compression, and tensile properties.

• New & Renewable Energy
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• v.19 no.3
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• pp.1-12
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• 2023

This study aims to evaluate the optimal size of the hydrogen facility to be installed in a zero-energy district in terms of load matching and facility efficiency. A mismatch between energy generation and consumption is a common occurrence in zero-energy districts. This mismatch adversely effects the energy grid. However, using an energy carrier such as hydrogen can solve this problem. To determine the optimal size of hydrogen fuel cells to be used on-site, simulation of hydrogen installation is required at both district-and building- levels. Each case had four operating schedules. Therefore, we evaluated eight scenarios in terms of load matching, heat loss, and facility operational efficiency. The results indicate that district-level installation of hydrogen facilities enables more efficient energy use. Additionally, based on the proposed model, we can calculate the optimal size of the hydrogen facility.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.5
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• pp.326-332
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• 2010

Critical response of seawater pump impeller shaft structure to various exciting loads is a fundamental factor in re-designing of the structure after its functional failure. In this paper, a typical case of the shaft structure's failure is investigated for re-designing purposes. Failure causes of interest are excessive bending moment, fatigue loads and dynamic resonance due to relevant motor rotation and unbalancing of the rotation loads. Static analyses of shaft structure under the conditions of concerned loads are carried out, followed by a dynamic investigation of the effects of resonance between the shaft and the motor on the structure. The relevant structural analyses are carried out using the Finite Element Methods combined with ANSYS code. Based on these, the primary cause for the shaft's structural failure is obtained. It is found that the change of the bending stiffness of the shaft is the primary concern in the re-designing process. A guideline for the re-design process of the seawater pump shaft structure is established, and a re-design scheme of the structure is proposed.

• Progress in Superconductivity and Cryogenics
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• v.25 no.3
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• pp.49-55
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• 2023

This paper presents the design of a re-liquefaction system as a BOG (boil-off gas) handling process in liquid hydrogen transport vessels. The total capacity of the re-liquefaction system was assumed to be 3 ton/day, with a BOR (boil-off rate) of 0.2 %/day inside the cargo. The re-liquefaction cycle was devised using the He-Brayton Cycle, incorporating considerations of BOG capacity and operational stability. The primary components of the system, such as compressors, expanders, and heat exchangers, were selected to meet domestically available specifications. Case studies were conducted based on the specifications of the components to determine the optimal design parameters for the re-liquefaction system. This encompassed variables such as helium mass flow rate, the number of compressors, compressor inlet pressure and compression ratio, as well as the quantity and composition of expanders. Additionally, an analysis of exergy destruction and exergy efficiency was carried out for the components within the system. Remarkably, while previous design studies of BOG re-liquefaction systems for liquid hydrogen vessels were confined to theoretical and analytical realms, this research distinguishes itself by accounting for practical implementation through equipment and system design.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.6
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• pp.153-158
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• 2017

Reducer is a device to transmit and change torque and speed from drive shaft to driven shaft with excellent transmission efficiency, and it is widely used in many areas today. Reduction gear consists of two axes, gear, bearing supporting axes, and housing. The simplest method to transmit rotation or power to multiple axes is to attach circular plates to two axes and contact each other. However, in this case, if increasing number of rotations or if contact pressure is small, because of slipping, it cannot transmit power. For problems for the current reducer case, it is heavy and its assembling and repair is difficult. In addition, there are few studies about manufacturing and performance testing of worm gear reducer, causing lack of the foundation to improve the product competition and the performance.

• Journal of Fashion Business
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• v.26 no.4
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• pp.136-153
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• 2022

The fashion industry is considered hazardous and a threatened to the environment. Due the negative perception, the industry should focus on sustainability as a social role. Therefore, several redesign fashion collaborations mainly focusing on renewing abandoned resources are already in place. The research method was based on previous studies, and 3 characteristics were derived: Redesign collaboration between fashion companies, Redesign collaboration between fashion & heterogeneous industries, and Redesign collaboration between the fashion industry & non-profit organizations. Those 3 characteristics were reviewed using 4 criteria. First, to establish and maximize the sustainable brand image and to be the best examples in environmental management, the organization endeavors to collaborate with various industries, institutions, and designers. Second is the expansion of the customer network through the spread of value consumption. Third is the creation of new values through a resource circulation structure. This means that the resource circulation structure system helps the partners to minimize on wastage. Fourth is the spread of de-boundary lines and the possibility of brand growth. Through collaboration with other industries, the boundaries of materials used in the fashion industry started to blur, thus expanding the continuous brand growth potential. The study derived the characteristics of redesign collaboration by systematically analyzing the cases. Further, the study looks forward to analyzing the characteristics of the products processed by redesign fashion collaborations in future research.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.6
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• pp.665-671
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• 2007

The purpose of this study is to find out a flow characteristics required by the design of a computer case and to provide information about the preliminary data of cooling efficiency of CPU and a flow inside of a case. We examined a flow characteristic-suction a tracing particle occurred from a surge tand installed at an inlet into a computer case and moving it to a exit duct-experimentally by using PIV. The experimental device was consists of a fan inflowing and discharging the air into the computer case and a slot installed with a CPU cooling ran add-on, and analyzed the data of Re-stress distribution, velocity distribution, and kinetic energy distribution. This research will make a great contribution to improvement of the efficiency and performance of notebook, workstation, server, and all the design of electronic devices using large scale integrated(LSI) as well as usual computers.