• 복식문화연구
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• 제30권3호
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• pp.403-413
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• 2022

The purpose of this study was to develop a 3D mesh-type impact protection pad with excellent motion adaptability and functionality by applying 3D printing technology. The hexagonal 3D mesh, which constitutes the basic structure of the pad, comprises two types: small and large. The bridge connecting the basic units was designed as the I-type, V-type, IV-type, and VV-type. After evaluating the characteristics of the bridge, it was found that the V-type bridge had the highest flexibility and tensile elongation. The hip joint pad and knee pad were completed by combining the hexagonal 3D mesh structure with the optimal bridge design. The impact protection pad was printed using a fused deposition modeling-type 3D printer with a filament made of thermoplastic polyurethane material, and the protection pad's performance was evaluated. When an impact force of approximately 6,500N was applied to the pad, the force attenuation percentage was 78%, and when an impact force of approximately 8,000N was applied, the force attenuation percentage was 75%. Through these results, it was confirmed that the 3D-printed impact protection pad with a hexagonal 3D mesh structure connected by a V-shaped bridge developed in this study can adapt to changes in the body surface according to movement and provides excellent impact protection performance.

• 한국입자에어로졸학회지
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• 제19권2호
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• pp.31-42
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• 2023

The charge and magnetic characteristics of LM (Low-metallic) and NAO (Non-asbestos-organic) brake wear particles were analyzed. The ratio of charged particles from total particles is about 86% of the LM pad and about 92% of the NAO pad. Number of charge per particle from the NAO pad is also higher than that of the LM pad. The ratio of magnetic particles from total particles increases with the particle size. The ratio of magnetic particles from the LM pad is about 15% for the particles with the size of 1 ㎛, and about 74% for ones with 5 ㎛. The ratio from the NAO pad is about 5% for the particles with the size from 0.5 ㎛ to 2 ㎛, and about 80% for the particles with 5 ㎛. Through the analysis of the components of the two pads with SEM-EDS (Scanning Electron Microscopy - Energy Dispersive X-ray Spectroscopy), it was found that the LM pad was occupied with more iron fraction than the NAO pad and that PM_2.5-10 was occupied with more iron fraction than PM_2.5. The particles smaller than 10 ㎛ (i.e. PM₁₀) from the LM pad contained about 83% of charged particles, about 43% of magnetic particles, and about 93% of charged or magnetic particles. PM₁₀ from the NAO pad contained about 88% of charged particles, about 15% of magnetic particles, and about 89% of charged or magnetic particles.

• 한국방사선학회논문지
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• 제15권6호
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• pp.899-909
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• 2021

손가락과 발가락 같은 작은 관절은 초음파 이미징 방식을 사용하여 평가하기에 작고 복잡한 구조물이지만, 최근 초음파 진단장치의 발전과 고주파 탐촉자의 개발로 정상적인 해부학과 다양한 병리 상태를 평가하는 데 근골격계 초음파검사가 유용한 도구로 사용되고 있다. 그러나 의료기관에 보편적으로 보급되어있는 접촉면 6 cm 길이의 선형 탐촉자(Linear Probe : 12-5 MHz)는 기존의 수용성 액체 초음파 젤 사용만으로는 인체의 굴곡진 부위에서 밀착이 되지 않아 영상 소실이 발생하는 검사의 한계가 지적되었고, 이러한 단점을 해결하기 위해 젤 패드의 사용이 증가 되고 있다. 현재 상용화된 워터젤 패드(Watergel Pad)는 사용 편리성이 뛰어나지만, 1회용 소모성 의료용품으로 재 반복 사용이 금지되고 비싼 단점이 있다. 본 연구에서 상용화된 워터젤 패드 사용으로 인한 경제적 부담을 해결하기 위해 저 비용의 수용성 식품 증점제 분말을 탐색하여 원형의 상태를 잘 갖춘 수분을 많이 함유한 탄력성 있는 젤 패드를 제작하였다. 초음파 정도관리용 팬텀 (N-365 Multipurpose Phantom) 영상 평가 결과 카파-카라기난 젤 패드, 아이오타-카라기난 젤 패드, 한천 젤 패드에서 허상 없이 모두 적합 기준안을 만족하였고 식품 증점제 분말을 구입하는 가격은 기존의 상용화된 워터젤 패드에 비해 약 38배 저렴하였다. 이러한 결과로 상용화된 고가의 1회용 워터젤 패드 대신 카파-카라기난, 아이오타-카라기난, 한천 분말을 이용하여 커버 없이 고형화된 탄력성 있는 젤 패드를 만들어 사용한다면 활용성, 편리성, 응용성 등이 우수한 초음파 전달매질의 대체물질로 가능성을 제안한다.

• 한국정밀공학회지
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• 제25권8호
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• pp.37-44
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• 2008

Nowadays, the increasing global competition forces manufacturer to reduce the cost and time for implementation of manufacturing system. The AR(augmented reality) technology as a new human-machine interface introduces a noteworthy perspective for a new manufacturing system design. Using AR technology, a physically existing production environment can be superimposed with virtual planning objects. Therefore, the planning tasks can be validated without modeling the surrounding environment of the production domain during short process planning time. In this paper, we introduce the construction of AR browser and determine the optimal environment parameters for field application of AR system through lots of tests. And, many methods such as multi-marker coordinate system, division of virtual objects and so on, are proposed in order to solve the problems suggested from initial field test. Based on these tests and results, the test-bed of C/Pad assembly system is configured and robot program for C/Pad assembly is generated based on AR system.

• 한국기계가공학회지
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• 제1권1호
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• pp.89-100
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• 2002

The purpose if this research was to improve the pressure distribution on the disk brake pad Not uniform pressure distribution on the disk brake pad generate the unbalance wear of it and the unbalance wear of disk brake pad generate vibration, noise, heat and reduce the braking capacity. For improve the pressure distribution on the pad in this research, upper face of caliper housing finger was cut. Two kinds of caliper which uncut and cut of finger face were compared the stress distribution by FEM analysis and real experiment. Also natural frequency and deforming displacement ware calculated. It was understood that pressure distribution could Improve by cut inside upper face of caliper housing finger.

• 한국유체기계학회 논문집
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• 제6권4호
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• pp.21-28
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• 2003

CMP (Chemical Mechanical Polishing) is to achieve adequate local and global planarization for future sub-micrometer VLSI requirements. In designing CMP, numerical computation is quite helpful in terms of reducing the amount of experimental works. Stresses on pad, concentration of particles and particle tracking are studied for design. In this research, the optimization of grooved pad shape of CMP is performed through numerical investigation of slurry flow in CMP process. The result indicates that the combination of sinusoidal groove and skewed pad is the most optimal shape among the twenty candidates. Useful information can be obtained in velocity, pressure, stress, concentration of particles and particles trajectories, etc.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1998년도 학술발표회 발표논문집
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• pp.262-268
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• 1998

This study were performed to find the cooling effect and to provide design data during summer season. for the Pad ＆ Fan system of Venlo type greenhouse. The temperature and humidity variation along the greenhouse width and wind velocity in the greenhouse were surveyed. Also, the influence of shading on the cooling effect were analyzed. While Pad ＆ Fan system were operated, the temperature, humidity and wind velocity in greenhouse were different by the distance from the Pad and the height from the ground. The temperature difference between Pad and Fan was about 8.1$^{\circ}C$~10.4$^{\circ}C$ without shading and about 4.4$^{\circ}C$~5.5$^{\circ}C$ with shading.

• Tribology and Lubricants
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• 제2권1호
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• pp.61-68
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• 1986

Effects of the ram-pressure on the THD-performance of pivoted pad thrust bearings are investigated experimentally. A sector-shaped tilting pad thrust bearing and a rotating disk are used. Temperature distribution on the disk surface as well as on the pad surface, distribution of the pressure generated within the fluid film, and the film thickness are measured continuously in the circumferential direction after thermal equilibrium is established. The ram-pressure is proportional to the mean pressure of oil film and to the rotational speed of the disk and affects the maximum pressure and the pressure distribution. The temperature rise on the mating surface of the disc and the pad, contacting with the oil film, is proportional to to the bearing load and the disk speed. The ram-pressure and the temperature rise on the disk surface are dominant factors that affect the THD-performance of pivoted pad thrust bearings.

• Tribology and Lubricants
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• 제12권1호
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• pp.29-35
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• 1996

The static and dynamic stability analysis of air-lubriceted tilting pad journal bearing which considers tilting effect of each pad and preload but neglects pad inertia were performed. And these characteristic analysis were performed with elasticity effect too. A direct numerical method is used in calculating the static characteristics such as load carrying capacity, firction force and perturbation method is used for calculation of dynamic characteristics. The stability analysis was performed with the variation of bearing number, eccentricity ratio and attitude angle considering pad elasticity effect.

• 반도체디스플레이기술학회지
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• 제12권1호
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• pp.61-65
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• 2013

We investigated the wearable dynamics of diamond spherical abrasive during the substrate surface polishing under the pad compression via classical molecular dynamics modeling. We performed three-dimensional molecular dynamics simulations using the Morse potential functions for the copper substrate and the Tersoff potential function for the diamond abrasive. The pad hardness had a big impact on the wearable dynamics of the abrasive. The moving speed of the abrasive decreased with increasing hardness of the pad. As the hardness decreased, the abrasive was indented into the pad and then the sliding motion of the abrasive was increased. So the pad hardness was greatly influenced on the slide-to-roll ratio as well as the wearable rate.