• Title/Summary/Keyword: Tight Tolerance

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Suggestion of the Bicycle Wear Design based on Active Senior Women's Preference (액티브 시니어 여성의 자전거의류 선호에 따른 디자인 제안)

  • Jung, Hee-Kyeong;Lee, Jeong-Ran
    • Fashion & Textile Research Journal
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    • v.17 no.4
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    • pp.604-612
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    • 2015
  • This study investigates preferred bicycle wear designs that can satisfy active senior consumers. A survey was conducted on 50-60's women who periodically rode bicycles. The results indicated a preference for slim designs and red colors. Jacket designs preferences were for a tight fit for size tolerance, stand collar style, and elastic band details for cuff styles. Pants design preferences were for a whole band waist belt type with a tight fit style such as leggings in pants silhouette, zipper details on the side line and ankle length. They also preferred styles with pads attached to underpants in the pad style and the part of the back waist in the pocket position. The survey showed four kinds of jacket design drawings on an ordinal scale rating. Results indicated a preference for set-in variation jackets with the red and gray color combination. Finally, we demonstrated bicycle wear design suggestions. The jacket applied different armhole line colors connected to the sleeve to make the waist slimmer; in addition, stretchable material helped improve armpit part functionality.

Efficient Multi-Step k-NN Search Methods Using Multidimensional Indexes in Large Databases (대용량 데이터베이스에서 다차원 인덱스를 사용한 효율적인 다단계 k-NN 검색)

  • Lee, Sanghun;Kim, Bum-Soo;Choi, Mi-Jung;Moon, Yang-Sae
    • Journal of KIISE
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    • v.42 no.2
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    • pp.242-254
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    • 2015
  • In this paper, we address the problem of improving the performance of multi-step k-NN search using multi-dimensional indexes. Due to information loss by lower-dimensional transformations, existing multi-step k-NN search solutions produce a large tolerance (i.e., a large search range), and thus, incur a large number of candidates, which are retrieved by a range query. Those many candidates lead to overwhelming I/O and CPU overheads in the postprocessing step. To overcome this problem, we propose two efficient solutions that improve the search performance by reducing the tolerance of a range query, and accordingly, reducing the number of candidates. First, we propose a tolerance reduction-based (approximate) solution that forcibly decreases the tolerance, which is determined by a k-NN query on the index, by the average ratio of high- and low-dimensional distances. Second, we propose a coefficient control-based (exact) solution that uses c k instead of k in a k-NN query to obtain a tigher tolerance and performs a range query using this tigher tolerance. Experimental results show that the proposed solutions significantly reduce the number of candidates, and accordingly, improve the search performance in comparison with the existing multi-step k-NN solution.

Position welding using disk laser-GMA hybrid welding (디스크 레이저-아크 하이브리드 용접을 이용한 포지션 용접)

  • Lim, Hyun-Sik;Kim, Jung-Hak;Kim, Cheol-Hee;Kim, Jeong-Han
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1299-1306
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    • 2007
  • The combination of laser beam and electric arc sharing common weld pool has widely been investigated since the late seventies, but it is beginning of the industrial uses. Recently, laser-GMA hybrid welding process showed possibility to overcome the tight gap tolerance with improved productivity. The laser-arc hybrid welding process is inherently complex because it has three kinds of process parameters: arc welding, laser welding and hybrid welding parameters. In this study, the optimum range of the process parameters were determined by high speed image analysis which could unveil the welding phenomena in laser-arc hybrid welding. The laser-arc hybrid welding was applied for position welding from the flat position to the overhead position and the welding characteristics were investigated.

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Simulation of Sintering for the Complex Ceramic Bodies by NASTRAN

  • Lee, Sang-Ki;Kim, Hyung-Jong;Lee, June-Gunn
    • The Korean Journal of Ceramics
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    • v.5 no.3
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    • pp.235-238
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    • 1999
  • In a ceramic green body, some degree of nonuniformity in density always presents. These differences in green density will appear as nonuniform shrinkage after sintering takes place. For the complex ceramic bodies with various curves and angles, therefore, it is quite difficult to foresee the final dimensions precisely after sintering. This simulation study shows that, considering the sintering process as a thermal shrinkage phenomenon, the use of NASTRAN enables to predict the precise shape of a sintered body. Based on this result, 'the reverse engineering technique' has been developed that can unfold the exact dimensions of a green body to have the desired shape after sintering. This approach will provide a simple and useful tool for ceramic engineers to fabricate complicate bodies with tight dimensional tolerances.

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Development of Injection Mold Design System for Pseudo-Solid Part Models (의사 솔리드 부품 모델에 대한 금형 설계 시스템의 개발)

  • Lee S.H.;Lim S.L.;Lee K.S.
    • Korean Journal of Computational Design and Engineering
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    • v.10 no.3
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    • pp.151-161
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    • 2005
  • This paper describes the parting and Boolean operations for a pseudo-solid model of a plastic part, and their application to injection mold design. Here, a pseudo-solid model means a sheet model that looks like a solid model, but its boundary is not closed. When a solid model created in a different CAD system is imported through a standard data exchange file format, in most cases, a pseudo-solid model may be created due to tolerance or some other problems. However, most existing mold design systems based on solid modeling kernels require a complete part solid model. Therefore, mold designers have to do time-consuming healing operations to convert a pseudo-solid to solid. To eliminate or reduce the healing pre-process for mold design, in this paper, we proposed the parting and Boolean Operations on pseudo-solid part models. This paper also describes their detailed implementation and a case study.

Lens Assembling Methods for Near Field Optical Storage Devices (근접장 광 저장 장치를 위한 렌즈 조립)

  • Shin Yun Sup;Park Jin Moo;Lee Jeong Uk;Jeong Mi Hyun;Seo Jeong Kyo;Choi In Ho
    • 정보저장시스템학회:학술대회논문집
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    • 2005.10a
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    • pp.2-3
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    • 2005
  • Air gap control method using a conventional actuator for near field recording technology has been reported. To achieve good performance in the air gap servo and further experiments, the assembling between OL and SIL is the critical procedure. A lens set with NA 1.45 at 405 m has been assembled and tested by using a Twyman-Green interferometer. The tolerance of assembling is very tight and the designing and adjusting procedure must be carefully controlled.

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Position/force Control using 6-axis Compliance Device for Chemical Coupler Assembly (케미컬 커플러 체결을 위한 순응장치를 이용한 위치/힘 동시제어)

  • Park, Shi-Baek;Kim, Han-Sung
    • Journal of the Korean Society of Industry Convergence
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    • v.25 no.5
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    • pp.909-915
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    • 2022
  • In this paper, a robot automation technology for chemical tank lorry unloading is presented. Handling chemical coupler between tank lorry and ACQC system may be hazardous or toxic to human operators, therefore robot automation is essential. Due to tight tolerance between couplers, even small pose error may result in very large internal force. In order to resolve the problem, compliance between male and female couplers should be introduced with 6-axis compliance device with F/T sensing. The proposed robot automation system consists of a collaborative robot, 6-ax is compliance device with F/T sensing, linear gripper, and robot vision. The position/force control algorithm and experimental results for assembling chemical couplers are presented.

Development of Robotic Tools for Chemical Coupler Assembly

  • Jeong, Sung-Hun;Kim, Gi-Seong;Park, Shi-Baek;Kim, Han-Sung
    • Journal of the Korean Society of Industry Convergence
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    • v.25 no.6_1
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    • pp.953-959
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    • 2022
  • In this paper, the design result of robotic tools and the development of robot control system for chemical coupler assembly are presented. This research aims to eliminate the risk of chemicals exposed to human operators by developing the robotic tools and robot automation system for chemical tank lorry unloading that were done manually. Due to tight tolerance between couplers, even small pose error may result in very large internal force. In order to resolve the problem, the 6-axis compliance device is employed, which can provide not only enough compliance between couplers but also F/T sensing. The 6-axis compliance device having large force and moment capacity is designed. A simple linear gripper with rack-and-pinion is designed to grasp two sizes of couplers. The proposed robot automation system consists of 6-DOF collaborative robot with offset wrist, 6-axis compliance device with F/T sensing, linear gripper, and two robot visions.

Germinal Center Formation Controlled by Balancing Between Follicular Helper T Cells and Follicular Regulatory T Cells (여포 보조 T세포와 여포 조절 T세포의 균형 및 종자중심 형성)

  • Park, Hong-Jai;Kim, Do-Hyun;Choi, Je-Min
    • Hanyang Medical Reviews
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    • v.33 no.1
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    • pp.10-16
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    • 2013
  • Follicular helper T cells (Tfh) play a significant role in providing T cell help to B cells during the germinal center reaction, where somatic hypermutation, affinity maturation, isotype class switching, and the differentiation of memory B cells and long-lived plasma cells occur. Antigen-specific T cells with IL-6 and IL-21 upregulate CXCR5, which is required for the migration of T cells into B cell follicles, where these T cells mature into Tfh. The surface markers including PD-1, ICOS, and CD40L play a significant role in providing T cell help to B cells. The upregulation of transcription factor Bcl-6 induces the expression of CXCR5, which is an important factor for Tfh differentiation, by inhibiting the expression of other lineage-specific transcription factors such as T-bet, GATA3, and RORγt. Surprisingly, recent evidence suggests that CD4 T cells already committed to Th1, Th2, and Th17 cells obtain flexibility in their differentiation programs by downregulating T-bet, GATA3, and RORγt, upregulating Bcl-6 and thus convert into Tfh. Limiting the numbers of Tfh within germinal centers is important in the regulation of the autoantibody production that is central to autoimmune diseases. Recently, it was revealed that the germinal center reaction and the size of the Tfh population are also regulated by thymus-derived follicular regulatory T cells (Tfr) expressing CXCR5 and Foxp3. Dysregulation of Tfh appears to be a pathogenic cause of autoimmune disease suggesting that tight regulation of Tfh and germinal center reaction by Tfr is essential for maintaining immune tolerance. Therefore, the balance between Tfh and Tfr appears to be a critical peripheral tolerance mechanism that can inhibit autoimmune disorders.

Improvement of Gap Bridging Ability in $CO_2$ Laser-GMA Hybrid Welding (조선용 강재의 $CO_2$레이저 GMA 하이브리드 용접에서 갭 브리징 능력 향상기술 개발)

  • Chae, Hyun-Byung;Kim, Cheol-Hee;Kim, Jeong-Han;Rhee, Se-Hun
    • Journal of Welding and Joining
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    • v.24 no.5
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    • pp.49-56
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    • 2006
  • For laser welding in shipbuilding industry, gap bridging capability is one of the most important characteristics to achieve the high productivity and good weld quality. Recently, laser-GMA hybrid welding process is regarded as a distinctive method to overcome the tight gap tolerance with improving the productivity. In this study, the influence of process parameters on the bead formation was experimentally analyzed and the relationship between the process parameters and geometric imperfections was investigated. It was revealed that undercut, excessive weld metal, excessive penetration and incompletely filled groove were the major geometric imperfections. The optimized wire feeding and arc pressure were necessary to ensure the gap bridging ability. The approach to select the process parameters was conducted for butt welding with up to 2mm joint gap, in which the sound weld beads were generated without changing the welding speed.