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Part Similarity Assessment Method Based on Hierarchical Feature Decomposition: Part 1 - Using Convex Decomposition and Form Feature Decomposition (계층적 특징형상 정보에 기반한 부품 유사성 평가 방법: Part 1 - 볼록입체 분할방식 및 특징형상 분할방식 이용)

  • 김용세;강병구;정용희
    • Korean Journal of Computational Design and Engineering
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    • v.9 no.1
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    • pp.44-50
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    • 2004
  • Mechanical parts are often grouped into part families based on the similarity of their shapes, to support efficient manufacturing process planning and design modification. The 2-part sequence papers present similarity assessment techniques to support part family classification for machined parts. These exploit the multiple feature decompositions obtained by the feature recognition method using convex decomposition. Convex decomposition provides a hierarchical volumetric representation of a part, organized in an outside-in hierarchy. It provides local accessibility directions, which supports abstract and qualitative similarity assessment. It is converted to a Form Feature Decomposition (FFD), which represents a part using form features intrinsic to the shape of the part. This supports abstract and qualitative similarity assessment using positive feature volumes. FFD is converted to Negative Feature Decomposition (NFD), which represents a part as a base component and negative machining features. This supports a detailed, quantitative similarity assessment technique that measures the similarity between machined parts and associated machining processes implied by two parts' NFDs. Features of the NFD are organized into branch groups to capture the NFD hierarchy and feature interrelations. Branch groups of two parts' NFDs are matched to obtain pairs, and then features within each pair of branch groups are compared, exploiting feature type, size, machining direction, and other information relevant to machining processes. This paper, the first one of the two companion papers, describes the similarity assessment methods using convex decomposition and FFD.

Dimensional Changes and Residual Stress of Spur Gear According to the Manufacturing Processes -Comparison of Cold Forging Part with Machining Part- (스퍼기어의 제조공정에 따른 치수변화와 잔류응력에 관한 연구 -냉간 단조기어와 기계가공기어 비교-)

  • Kwon, Y.C.;Lee, J.H.;Lee, C.M.;Lee, Y.S.
    • Transactions of Materials Processing
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    • v.16 no.8
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    • pp.575-581
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    • 2007
  • The high dimensional accuracy of the cold forged part could be acquired by the accurate dimensional modification for the die, which is, the dimensional changes from the die through forged part to final part after heat treatment were considered. The experimental and FEM analysis are performed to investigate the dimensional changes from the die to final part on cold forged part, comparing with the machined gear. The dimension of forged part is compared with the die dimension at each stage, such as, machined die, cold forged part, and heat-treated-part. The elastic characteristics and thermal influences on forging stage are analyzed numerically by the $DEFORM-3D^{TM}$. The analyzed residual stress of forged part is considered into the FE-analysis for heat treatment using the $DEFORM-HT^{TM}$. The effects of residual stress affected into the dimensional changes could be investigated by the FEA. Each residual stress of gears was measured practically by laser beam type measurement.

Design of a Method for Disassembly Works on Recycle Products

  • Matsumoto, Toshiyuki;Yahata, Yuko;Shida, Keisuke
    • Industrial Engineering and Management Systems
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    • v.8 no.1
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    • pp.66-71
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    • 2009
  • This study proposes a new framework for designing disassembly methods. In recent years, environmental problems have become global issues. Recycling of used products or resources is recognized as a matter of significance since it may help reduce the risk of exhausting natural resources. Considering possible exhaustion of limited natural resources in the near future, reuse of products would gain more environmental significance. As yet, it relies hugely on manual disassembly, which labor cost places burden on the total recycling cost. The purpose of this study is to propose a methodology designing for manual disassembly works, and a creation method of a jig. By focusing on parts' connection and attachment relationship, parts are categorized in 5 categories (parent part, joint key part, attaching key part, child part, and independent part) according to the features that parts possess, and 3 kinds of connection relationships (parent part-joint key part connection, parent part-independent part connection and child part-child part connection) are clarified. Connection relationship and attachment relationship charts have also been created, and utilizing them, disassembly orders are settled, and a disassembly jig is devised. The proposed methodology is also applied to a real product and its work time is improved 42% form 31 to 13 seconds.

Study on stress transition mechanism by tensile and fracture characteristics of membrane material at bolting part in clamping part of membrane Structures (막구조 정착부의 볼트접합부 막재료의 신장 및 파단상태를 통한 응력전달체계에 관한 연구)

  • Kim, Hee-Kyun;Shim, Chun-Bo;Kim, Jae-Yeol
    • Journal of Korean Association for Spatial Structures
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    • v.23 no.4
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    • pp.97-105
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    • 2023
  • The membrane structure should maintain the membrane materials in tension for structural stability guaranty. The anchoring part in the membrane structure is an important part. It has the function to introduce tension into membrane materials and function to transmit stress which membrane materials receives to boundary structure such as steel frames. In this paper, it grasps anchoring system of the anchoring part in the membrane structure concerning the fracturing characteristic condition of membrane structure, and the influence which is caused to yield it designates the stress state when breaking the membrane structure which includes the anchoring part and that stress transition mechanism is elucidated as purpose. This paper follows to previous paper, does 1 axial tensile test concerning the bolting part specimen, grasp of fracturing progress of the bolting part and the edge rope and hardness of the rubber, does the appraisal in addition with the difference of bolt tightening torque. As a result, the influence which the bolt anchoring exerts on the fracturing characteristics of the membrane material in the membrane structure anchoring part is examined.

A HISTOMORPHOMETRIC STUDY OF BONE FORMATION AROUND IMPLANTS PLACED AFTER VERTICAL ALVEOLAR DISTRACTION IN THE DOG MEDEL (치조골신장 부위에 식립된 임프란트 주위의 골형성에 관한 연구)

  • Park, Jong-Oh;Rhu, Dong-Mok
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.33 no.4
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    • pp.312-321
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    • 2007
  • Purpose: Distraction osteogenesis has been applied to the maxillofacial implantology and good experimental and clinical results have been reported. However, histologic studies of implants placement on distraction osteogenesis of atrophic alveolar ridges are scarce. In this study, we compare the bone formation between in the transport part and in the distraction part by histomorphometric analysis. Materials & methods: Three adult beagle dogs were served as experimental subjects. The 2 premolars and 1st molar were extracted on the Lt. side of mandible in each beagle dog. After one month later, osteotomy was performed and distraction device was adapted. Distraction was performed with gradual incremental separation of two bone pieces at a rate of 1.0mm per day for 5 days. During consolidation phase, new bone was formed in the distraction zone between the separated bone pieces. 5 weeks after distraction phase, 3 implants were placed in each beagle dog. The implants were inserted through transport part and distraction part and inferior basal bone. The animals were sacrificed at 2 weeks, 4 weeks, and 12 weeks after implant placement. BIC and BA of implants on distraction part and transport part were measured histomorphometrically. Results: BIC, BA increased after implant placement as time goes by passes and new bone formation was slightly higher in transport part than in distraction part at 2 weeks, 4 weeks after implant placement. At 12 weeks after implant placement, BIC, BA of were 74%, 61% in transport part and 77%, 59% in distraction part, therefore there were no difference in BIC and BA between transport part and distraction part at 12 weeks after implant placement.

Validity and reliability of Korean version of quality of life questionnaire related with music perception and engagement of the elderly (난청노인의 한국어판 음악지각과 참여와 관련된 삶의 질 설문지의 타당도와 신뢰도)

  • Lee, Do-Hye;Choi, Chul-Hee
    • The Journal of the Acoustical Society of Korea
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    • v.41 no.1
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    • pp.87-98
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    • 2022
  • The purpose of this study is to develop the Korean version of Music-Related Quality of Life (K-MRQoL) for the elderly. The K-MRQoL consisted of Musical Ability, Attitude, Activity Frequency (PART 1) and Musical Ability, Attitude, Activity Important (PART 2). Each subcategory consists of Music Perception with 11 items and Music Engagement with 7 items. The validity and reliability of K-MRQoL were measured with Pearson's and Cronbach's alpha correlation coefficients and Independent t-test in total 30 elderly with normal hearing and 30 elderly with hearing loss from local welfare Centers and nursing homes. The correlation coefficients between total scores and PART 1 and PART 2 ranged from .701 to .948 and from .598 to .926, respectively. The internal consistency between total and Part 1 and Part 2 ranged from .846 to .931 and from .838 to .918, respectively. The test-retest correlations were .979, .970, and 979 for total, PART 1, and PART 2, respectively. The correlation between K-MRQoL and Quality of Communication Life Scale was .449. There were significant differences in total, PART 1, and PART 2 between the elderly with normal hearing and hearing loss. This indicates that the K-MRQoL can be used as a useful clinical tool to evaluate Music-related Quality of Life in the elderly with normal hearing or hearing loss.

Development of Vibration Absorption Device for the Transportation-Trailer System(I) - Characteristics for the existing vehicle - (수송 트레일러의 충격 흡수 장치 개발(I) - 보급기종에 대한 특성 및 진단 -)

  • 이홍주;홍종호;이성범;김성엽
    • Journal of Biosystems Engineering
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    • v.28 no.2
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    • pp.89-96
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    • 2003
  • This study was aimed to identify how the main body vibration of power tiller will be transmitted to the trailer, and to find out the basic information for demage reducing method of agricultural products during transportation. The vertical vibration acceleration level was measured at 6 positions, i.e. engine, hitch, seal and three parts of trailer (front middle, and rear) for the not driving but at the engine speeds of 1,000rpm and driving at 0.35m/s. The results of this research could be summarized as follows; 1. For not driving, the accumulated acceleration level up to 120Hz was 50% of total accelerations at engine part and those were 28~41% at other parts. Those up to 40Hz were 20~30% at engine and hitch part and 2~8% at trailer part. And those up to 20Hz were 13~20% at engine and hitch part and 1~4% at trailer part 2. For the driving with 0.35m/s at paved road, the average vertical accelerations were in the range of 0.005~0.058m/s$^2$. The lowest value of 0.005m/s$^2$ was showed at engine part and the value of 0.031-0.058m/s$^2$ was showed at trailer part. 3. For the driving with 0.35m/s, the accumulated value of average vertical accelerations showed the lowest value at engine parts md showed 5 times value of engine part at trailer part especially highest value at middle part of trailer. 4. For the driving with 0.35m/s, the accumulated acceleration level up to 120Hz was 75% of total accelerations at engine part and those were 20~42% at other parts. Ant those up to 20Hz and 40Hz were 24~26% at engine part and 0.1~0.6% at trailer part.

The Study on the Use of Angelicae Gigantis Radix in Uterus and Gynecology Part of Dongeuibogam (동의보감 胞門과 婦人門 처방 중 당귀 용례에 대한 연구)

  • Lee, Hye-In;Yoo, Dong-Youl
    • The Journal of Korean Obstetrics and Gynecology
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    • v.28 no.3
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    • pp.40-53
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    • 2015
  • Objectives The purpose of this study is to report the gynecologic use of Angelicae Gigantis Radix in uterus and gynecology part of Dongeuibogam. Methods I searched prescriptions containing Angelicae Gigantis Radix in uterus and gynecology part of Dongeuibogam and analyzed the selected prescriptions to research the use of Angelicae Gigantis Radix in uterus and gynecology part of Dongeuibogam. Results Prescriptions containing Angelicae Gigantis Radix are utilized for 10 disease patterns in uterus part. The number of prescriptions containing Angelicae Gigantis Radix is 50 in uterus part. Prescriptions containing Angelicae Gigantis Radix are utilized for 29 disease patterns in gynecology part. The number of Prescriptions containing Angelicae Gigantis Radix is 90 in gynecology part. Angelicae Gigantis Radix was taken as a sovereign, minister drug of prescriptions containing Angelicae Gigantis Radix of uterus and gynecology part. In many prescriptions, Angelicae Gigantis Radix is used in the treatment of amenorrhea and dysmenorrhea in uterus part. Prescriptions containing Angelicae Gigantis Radix are used to treat not only female infertility but also male infertility in gynecology part. The Samul-tang is the most useful prescription which contains Angelicae Gigantis Radix. Conclusions Angelicae Gigantis Radix is an effectual medicinal herb for menstrual disease, vaginal discharge, pregnancy disease, postpartum disease. So I consider that it is necessary to study methods which improve convenience and effect of prescriptions containing Angelicae Gigantis Radix.

Part-time Work in the UK: From Married Women's Work to Universal Flexible Work? (영국의 시간제 근로: 기혼 여성의 일에서 보편적 유연근로로의 변화?)

  • Woo, Myungsook
    • Korean Journal of Labor Studies
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    • v.17 no.1
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    • pp.325-350
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    • 2011
  • This article examines part-time work in the UK in terms of its characteristics and institutional contexts. Part-time jobs developed early due to the UK's liberal market institution and low level of public support for female employment. A large proportion of the employed women (about 40 percent) work part-time. Part-time work has been largely for married women. The expansion of part-time work in the UK was primarily market-driven and led by employers. Married women have worked part-time work primarily to accommodate their family responsibilities. There have been significant changes in labor market regulation in the UK since 1997. The Labor government legislated the Part-time Workers Regluations in 2000 to protect part-time workers. The government has also changed and newly implemented various laws and policies for work-life balance. There has been a real progress in improving the quality of part-time work overall. Nevertheless, we have not seen qualitatively different results in terms of female employment patterns and the qualify of part-time work so far. It has been largely constrained by the government's liberal orienation and voluntarism of labor relations in the UK.

AP224 based Feature Translation from 3D CAD through STEP Part111 (3차원 CAD에서 STEP Part111을 통한 AP224 특징형상 데이터 번역)

  • Kim, J.H.
    • Korean Journal of Computational Design and Engineering
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    • v.11 no.4
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    • pp.303-314
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    • 2006
  • The exchange of CAD (Computer Aided Design) models between different CAD systems and to downstream applications such as manufacturing has become very important to modem industry. One serious current issue is that the process cannot automatically import existing 3-D solid models in a variety of commercial CAD formats into the process without manually re-mastering the model in current standard including "SIEP AP(Application Protocol) 203 Edition 1" To fully integrate technical data from the design agency to the shop floor, design intent and validated 3D geometry of feature based parametric CAD model should be brought into the standardized processes. To overcome this limitation, AP203 Edition 2 (Ed.2) and its related STEP parts such as Part55, Part108, Part109, Part111 and Part112 are starting to be available to handle this problem. The features in Part111 are harmonized with the machining features available in AP224. This paper is focused on two mapping technologies: CAD to Part111 mapping and Pat111 to AP224 mapping including case studios and it will provide the guideline about what should be done next in the AP203 Ed.2 to AP224 mapping. The final goal of this project is to integrate technical data from CAD to AP224 based manufacturing information through AP203 Ed.2.