• Journal of Intelligence and Information Systems
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• v.4 no.1
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• pp.1-10
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• 1998

Process planning is a very complex task and requires the dynamic informatioon of shop foor and market situations. Process plan selection is one of the main problems in the process planning. In this paper, we propose a new process plan selection model considering operation flexibility for the computer aided process planing. The model is formulated as a 0-1 integer programming considering realistic shop factors such as production volume, machining time, machine capacity, transportation time and capacity of tractors such as production volume, machining time, machine capacity, transportation time capacity of transfer device. The objective of the model is to minimize the sum of the processing and transportation time for all parts. A genetic algorithm a, pp.oach is developed to solve the model. The efficiency of the proposed a, pp.oach is verified with numerical examples.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.881-883
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• 2022

고객사에 납품하는 웨이퍼의 안정적인 공급을 위한 웨이퍼 엣지의 결함 검출 장비다. 본 연구에서는 OpenCV와 임베디드 시스템, 머신러닝, 전자 회로 그리고 센서/카메라 기술을 핵심 기술로 R&D 한다. 고객사에서 불량 웨이퍼 발생에 대응하기 위한 장비의 데이터를 생산하여 고객과의 신뢰도 향상 및 유지를 할 수 있다. 그리고 결함이 특정 공정 지점에서 발생하는지 탐색할 수 있다.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.112-120
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• 2021

Recently, the number of consumers using digital online distribution platforms is increasing. This caused the rapid growth of the e-commerce market and increased delivery volume in urban areas. The logistics system, designed ar006Fund the city center to handle the delivery volume, operates a delivery system from the outskirts of the city to the urban area using cargo trucks. This maintains an ecosystem of high-cost and inefficient structures that increase social costs such as road traffic congestion and environmental problems. To solve this problem, research is being conducted worldwide to establish a high-efficiency urban joint logistics system using urban railway facilities and underground space infrastructure existing in existing cities. The joint logistics system begins with linking unmanned delivery automation services that link terminal delivery such as cargo classification and stacking, infrastructure construction that performs cargo transfer function by separating from passengers such as using cargo platform. To this end, it is necessary to apply the device to the vertical and horizontal transportation machine supporting the vertical transfer in the flat space of the joint logistics terminal, which is the base technology for transporting cargo using the transfer robot to the destination designated as a freight-only urban railway vehicle. Therefore, this paper aims to derive holistic viewpoints needs for design requirements for vertical and vertical transportation machines and freight transportation standard containers, which are underground railway logistics transport devices to be constructed by urban logistics ecosystem changes.

• Progress in Superconductivity and Cryogenics
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• v.25 no.2
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• pp.14-18
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• 2023

Superconducting layers deposited on the metal substrate using the pulsed laser deposition process (PLD) play a crucial role in exploring new applications of superconducting wires and enhancing the performance of superconducting devices. In order to improve the superconducting property and increase the throughput of superconducting wire fabricated by pulsed laser deposition, high temperature heating device is needed that provides high temperature stability and strong durability in high oxygen partial pressure environments while minimizing performance degradation caused by surface contamination. In this study, new heating device have been developed for PLD process that deposit and growth the superconducting material continuously on substrate using reel-to-reel transportation apparatus. New heating device is designed and fabricated using iron-chromium-aluminum wire and alumina tube as a heating element and sheath materials, respectively. Heating temperature of the heater was reached over 850 ℃ under 700 mTorr of oxygen partial pressure and is kept for 5 hours. The experimental results confirm the effectiveness of the developed heating device system in maintaining a stable and consistent temperature in PLD. These research findings make significant contributions to the exploration of new applications for superconducting materials and the enhancement of superconducting device performance.

• Journal of Biosystems Engineering
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• v.30 no.3 s.110
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• pp.147-154
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• 2005

The improved hitch device, which connecting the trailer to power tiller, was developed. This device, composed with spring and rubber, could reduce the vibration and shock levels during driven on off-road. The vertical vibration accelerations for the improved hitch device were measured at 6 positions, i.e. engine, hitch, seat, and three points in trailer (front, middle, and rear) for not driving but at low engine speed of 500 rpm, and compared with the existing hitch device. The results of this study could be summarized as follows; The average vibration acceleration up to 120 Hz was $0.4m/s^2$ at engine part, but it was 0.08 and $0.05m/s^2$ at trailer for existing and improved hitch device, respectively. About $38\%$ of average acceleration level could be absorbed for the improved hitch device compared with existing hitch device. The average vibration acceleration up to 40 Hz was reduced to 0.12 and $0.06m/s^2$ at trailer for existing and improved hitch device respectively, showing the reduction effect of $50\%$. The maximum acceleration occurred at up to 20 Hz of low frequency was much higher than total acceleration occurred at up to 120 Hz, which means that much loss or damage could be occurred during transporting of agricultural products on off-road. The portions of average acceleration occurred at up to 20 Hz of low frequency were $27\%\;and\;21\%$ for the existing and improved hitch device, respectively.

• Earthquakes and Structures
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• v.9 no.5
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• pp.1029-1044
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• 2015

To investigate the seismic pounding response of long-span bridges with high-piers under strong ground motions, shaking table tests were performed on a 1/10-scaled bridge model consisting of three continuous spans with rigid frames and one simply-supported span. The seismic pounding responses of this bridge model under different earthquake excitations including the uniform excitation and the traveling wave excitations were experimentally studied. The influence of dampers to the seismic pounding effects at the expansion joints was analyzed through nonlinear dynamic analyses in this research. The seismic pounding effects obtained from numerical analyses of the bridge model are in favorable agreement with the experimental results. Seismic pounding effect of bridge superstructures is dependent on the structural dynamic properties of the adjacent spans and characteristics of ground motions. Moreover, supplemental damping can effectively mitigate pounding effects of the bridge superstructures, and reduce the base shear forces of the bridge piers.

• Transactions of the KSME C: Technology and Education
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• v.3 no.3
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• pp.165-173
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• 2015

This paper presents numerical results of static structural stability analysis in development of a vertical transfer device of a PRT(Personal Rapid Transit) vehicle. The vertical transfer of a fully occupied vehicle operating on a road network is the first attempt, which is expected to contribute to overcome the limitations of conventional 2-dimensional operation mode. In particular, the vertical transfer apparatus designed based on vertical circulating conveyors is capable of continuous transfer without time delay so that it enables to accommodate a high traffic density. This system has been frequently used in a logistics field; however, it is essential to assess a structural integrity because an external force by a vehicle weight is exerted on the conveyors in the form of a concentrated load unlike a conventional logistic transport. In this study, prior to the production process, the structural performance of the pilot design in an early stage is numerically evaluated using the commercial finite element method (FEM) solver (i.e., $Ansys^{(R)}$).

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.4
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• pp.100-115
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• 2020

Recently, with the development of various sensors and communication technologies, the market for wearable devices capable of recording physical activity in connection with a smartphone is expanding. The purpose of this study is to analyze physical activity for each transportation modes in order to utilize wearable devices in the field of transportation. This study consists of three steps: data collection, basic statistical analysis, and physical activity analysis. Four adult males and females were recruited as investigators, and physical activity and route information were collected through Fitbit, a commercial wearable device. From the collected physical activity information, a percentage of heart rate reserve (%HRR) using a heart rate was derived and used for analysis. As a results, it was found that there is a statistically significant difference in heart rate for each transportation mode, and physical activity intensity is the highest when walking. In addition, the results of physical activity analysis for the case of using different routes for the same OD were presented. The results presented in this study are expected to be used as basic data for preparing public transportation activation policies and providing customized services for the future.

• Journal of Climate Change Research
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• v.7 no.2
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• pp.177-184
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• 2016

Recently, the need for technology development of commercial vehicle fuel consumption has emerged. Fuel economy improvement of transport equipment and transportation efficiency, and increasing attention to the logistics cost reduction measures. Increasing attention to the logistics cost reduction measures by fuel economy improvement of transport equipment and transportation efficiency. In this study, we have installed aerodynamic reduction device (side skirt, boat tail) to 14.5 ton cargo trucks and 45 ft tractor-trailers. And the fuel consumption was compared installed before and after. Fuel economy assessment for the aerodynamic reduction value device was tested by modifying the SAE J1321 Joint TMC/SAE Fuel Consumption Test Procedure - Type II test in according domestic situation. Greenhouse gas reductions were calculated in accordance with the scenario, including fuel consumption test results. When the 14.5 ton cargo trucks has been equipped with side skirts and boat tail, it confirmed the improvement in fuel efficiency of 4.72%. One Heavy-duty truck's the annual greenhouse gas reductions value are $6.86ton\;CO_2\;eq$. And if applying the technology to more than 50% of registered 15 ton trucks, greenhouse gas reductions are calculated as $686,826ton\;CO_2\;eq./yr$.

• Design & Manufacturing
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• v.17 no.2
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• pp.1-8
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• 2023

This study aims to enhance the price and quality competitiveness of imported tiles by developing a robotic tile production automation line. The development process involved several steps, such as requirement analysis, derivation of technical specifications, conceptual design, engineering feasibility review, detailed design, and production. Emphasis was placed on the transfer process of the tiles' molds, and technological advancements were achieved through engineering interpretation, feasibility review, and performance evaluation. The developed automation system incorporates key specifications to ensure a transfer success rate of over 90%, thereby ensuring stable transportation of the tiles and minimizing defect rates during production. The maximum weight capacity for tile pick-up was set above 6 kg, allowing effective handling of tiles weighing 6 kg or less in automated tasks. Furthermore, the system enables safe and precise movement of the tiles to the desired location, with a transfer distance of at least 1.3 m and a transfer speed exceeding 0.2 m/sec, thereby increasing production efficiency.