• 한국공간구조학회논문집
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• 제20권4호
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• pp.185-192
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• 2020

A new lighting support structure composing of two-way wires and pulley, a pulley-type wireway system, was developed to improve the seismic performance of a ceiling type lighting equipment. This study verifies the seismic performance of the pulley-type wireway system using a numerical approach. A theoretical model fitted to the physical features of the newly-developed system was proposed, and it was utilized to compute a frictional coefficient between the wire and pulley sections under tension forces. The frictional coefficient was implemented to a finite element model representing the pulley-type wireway system. Using the numerical model, the seismic responses of the pulley-type wireway system were compared to those of the existing lighting support structure, a one-way wire system. The addition of the pulley component resulted in the increasement of energy absorption capacity as well as friction effect and showed in significant reduction in maximum displacement and oscillation after the peak responses. Thus, the newly-developed wireway system can minimize earthquake-induced vibration and damage on electric equipment.

• 한국자동차공학회논문집
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• 제16권6호
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• pp.39-47
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• 2008

In this research, a web-based design support system is constructed for the design process of automotive steel pulley to gather engineering knowledge from pulley design data. In the design search module, a clustering tool for design data is proposed using K-means clustering algorithm. To obtain correlational patterns between design and FEA (Finite Element Analysis) data, a Multi-layer Back Propagation Network (MBPN) is applied. With the analyzed patterns from a number of simulation data, an estimation of minimum von mises can be provided for given design parameters of pulleys. The case study revealed fast estimation of minimum stress in the pulley within 12% error.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.639-640
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• 2006

Many companies in mechanical engineering fields have accumulated information of design and manufacturing. The Enterprise Resource Planning (ERP) and Product Data Management (PDM) systems help information gathering and data managing. However, these systems are not flexible to support suitable functionality for specific product because these systems deal with entire enterprise resources. To cope with this issue, a web-based design support system was constructed for the design process of automotive steel pulley. This system provided 1) search service for part design with key word and clustering map, and 2) estimation service of maximum stress. These services reduced design time by reducing iterative jobs with Computer Aided Design (CAD) and Computer Aided Engineering (CAE) for stress analysis, and by enhancing search for existing data of steel pulley.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 추계학술대회 논문집
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• pp.201-202
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• 2006

• 로봇학회논문지
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• 제18권2호
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• pp.189-196
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• 2023

An abdominal brace is a recommended treatment for patients with lumbar spinal disorders. However, due to the nature of the static brace, it uniformly compresses the lumbar region, which can weaken the lumbar muscles or create a psychological dependence that worsens the condition of the spine when worn for an extended period of time. Due to these issues, doctors limit the wearing time when prescribing it to patients. In this paper, we propose a device that can dynamically provide abdominal pressure and support according to the lumbar motion. The proposed device is a wearable robot in the form of a brace, with actuators and a driving unit mounted on the brace. To enhance wearability and reduce the weight of the device, worm gears actuator and a multi-pulley mechanism were adopted. Based on the spinal motion of the wearer measured by the Inertia measurement unit sensors, the drives wire by driving pulley, which provide tension to the multi-pulley mechanism on both sides, dynamically tightening or loosening the device. Finally, the device can dynamically provide abdominal pressure and support. We describe the hardware and system configuration of the device and demonstrate its potential through basic control experiments.

• 산업기술연구
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• 제21권B호
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• pp.281-286
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• 2001

In this study, product design and prototype manufacturing of a plastic water-pump pulley has been tried. The designed model is supposed to be made of 33 % glass reinforced resin of which the tensile strength is 180 MPa, and has 24 ribs on each side to increase its structural strength. Structural analysis under a static load of 300 kgf acting on both edges of the belt has been carried out using a commercial finite element code, MARC. The analysis result showed the maximum effective stress near a rib of designed model would be at most 35 MPa (less than 20% of the tensile strength), therefore, the plastic product would be sufficiently safe under that loading condition. On the basis of the structural analysis, a prototype of the designed model has been manufactured by using the fused deposition modelling (FDM) method which is one of the rapid prototyping (RP) methods, using ABS resin and support materials. The CAD data exported to the RP system in STL format was prepared by a commercial solid modeling software, SolidWorks. It has been proved that the plastic pulley can successfully replace the existing flow-formed steel product.

• 재활복지공학회논문지
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• 제11권1호
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• pp.29-35
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• 2017

기존의 가정용 요양침대는 매트리스 지지판(mattress support platform) 하부에 설치된 복잡한 기구부로 인해 저상화 실현이 어려웠다. 본 논문에서는 등판과 다리판의 각도를 조절하면서도 저상화가 가능한 요양침대의 구동 메커니즘을 제안한다. 등판과 다리판의 메커니즘은 듀얼 모터(dual motor)를 적용하고, 최적화 기법으로 설계변수를 결정하였다. 승강 메커니즘은 풀리(pulley)구조를 적용하여 제한된 구동기의 가동범위를 최대 두 배까지 높일 수 있도록 설계하였다. 건강한 5명의 피험자($24.4{\pm}0.5$세)가 방바닥에서 240mm의 저상 프로토타입 요양침대와, 600mm의 일반적인 높이의 침대에 올라갈 때의 그 이동 거리를 측정하여 저상화 침대에 대한 유효성을 평가하였다. 그 결과 저상 요양침대를 사용할 때의 이동 거리는 기존 높이의 침대에 비해 평균 38% 작았다. 이것은 저상요양침대가 고령자의 신체적 부담을 줄여주며, 일반침대보다 일상생활 지원에 효과적이라는 것을 보여주었다.

• 한국신뢰성학회지:신뢰성응용연구
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• 제11권2호
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• pp.111-126
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• 2011

The clutch coil mounted on the automotive air conditioner is an important part which actuates the clutch to connect or disconnect the pulley and the compressor according to the climate control condition in an automobile. Here, it is generally required that the clutch coil should ensure the long term durability requirement, such as a warranty for the 10 years of field operation or 160,000 km driving, especially in a brand new item, and so forth. However, some difficulties have arisen in restoring its credibility, since domestic specifications for the part have not been yet unified. In order to ensure the reliability, test methods and assessment criteria should be standardized. Moreover, assessed lifetime under specific conditions and potential failure analysis would be important. In this study, lifetime test specifications for the clutch coil have been reviewed and methodological suggestions are provided to ensure reliability, utilizing a quality function deployment through the potential failure mode effect analysis.

• 대한물리치료과학회지
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• 제31권1호
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• pp.16-32
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• 2024

Background: Exercise equipments and assistive devices for the disabled are being developed, but improvements for usability are still needed. The purpose of this study was to improve and utilize the developed exercise equipment and assistance devices by conducting usability test for people with spinal cord injury. Design: Cross-sectional Study. Methods: Scenarios and usability indicators were derived by conducting a preliminary usability test, 5 non-disabled men and women aged 19 or older. In the scenario, a total of 9 tasks were sequentially performed, including 2 tasks of entry and exit, 5 tasks of assistance devices and weight stack adjustment, and 2 tasks of pre exercise and exercise. The usability indicators were task success (success or fail), execution time (sec), safety, and convenience. For safety, 7 questions (Likert scale, 1~5 point) related to safety, stability and hazard were derived, and for convenience, the system usability scale (SUS score) was used (range: 0~100, 50 percentile rank is 68 point). Results: As a result of the usability test of people with spinal cord injury, there was a large variation among subjects in the task of adjusting the position of the pulley and support in the execution time (11.64~25.44 seconds), and one person failed to adjust the pulley. The safety level showed a lower score (score = 3 points) than other items in the item of entrapment or skin pressure, and in the case of SUS, the average score was 64.5 points, which was close to the acceptable level. Conclusion: Through the usability test, it was confirmed that exercise equipment for the disabled needs improvement in operability, pinching, and pressure, and that it is necessary to develop an assistive device that provides unrestrained posture information (biofeedback) to maintain correct posture during exercise.