• Title/Summary/Keyword: Fastening

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Histological Characteristics of Tumorous Wood Formed in a Stem of Robinia pseudoacacia L. by Artificial Fastening (인위적(人爲的)인 결체(結締)에 의해 형성(形成)된 아까시나무 수간(樹幹)의 종양재(腫瘍材)에 관한 조직특성(組織特性))

  • Eom, Young Geun
    • Journal of Korean Society of Forest Science
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    • v.80 no.4
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    • pp.408-415
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    • 1991
  • A tumorous wood formed in a stem of Robinia pseudoacacia L. by steel wire fastening was investigated and compared with normal wood in the anatomy of histological aspect. The tumorous wood appeared to differ from normal wood in irregular orientations of some pores, most wood fibers, and rays deviated from normal direction, somewhat radially elongated pores on cross surface, occasionally distorted wood fiber tips between rays on radial surface, large ray width and height, commonly entangled arrangement of wood fibers on radial surface, frequent occurrence of pore multiples in the latewood, frequent occurrence of gelatinous fibers, and dark gummy substances partially enclosed in the lumina of wood fibers, rays, and axial strand parenchymas.

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Research for the Transformable Knit Design Applied by North European Traditional Knit Patterns (북유럽 전통 니트 문양을 활용한 트랜스포머블(Transformable) 니트 디자인 연구)

  • Lee, Yejin;Lee, Younhee
    • Journal of the Korean Society of Costume
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    • v.66 no.1
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    • pp.108-121
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    • 2016
  • The objective of the study is to propose diverse knitwear designs by expanding the scope of the use and application of knit fabric. The study looked into diversifying the knitwear designs by using different types of zippers and with the combination of the diversity given by the zipper used in attachable and detachable method and the traditional North European knit patterns. One way of contributing to the diversity of fashion design is to use the zipper, as it can be implemented as an attachable and detachable fastening system. Also, the combination of North European traditional knit patterns with knit fabric can create a new and unique knit styling. The content of the research focuses on the history and definition of North European traditional knitwear based on the analysis of theoretical background, types, and characteristics of the knit patterns. Case studies were observed to show the application of knit patterns. The methods of the study used are preceding research along with research, collection, analysis of data, information from Korean and foreign literature, and Internet websites. During knitwear production, the two types of zippers were used in combination with four traditional Northern European knitwear Aran, Fair Isle, Nordic, and Ropy. The knitting techniques applied in the process were cable fisherman (5GG, SES 124CS) and Tubular Jacquard (3GG, 7GG, SES 122CS) for knitting machinery, and the technique of whole garment for hand knitting.

A Study on the Behavior of Class 900 Flange Joints with Metal Ring Gaskets (금속 링 개스킷이 삽입된 Class 900 플랜지 조인트의 거동에 관한 연구)

  • Lee, Min-Young;Jeong, Doo-Hyung;Kim, Byung-Tak
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.1
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    • pp.34-41
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    • 2018
  • A flange joint is a pipe connection used to prevent the leakage of high-pressure fluids by inserting a gasket and tightening the bolts. Among several kinds of gaskets available, metal ring type joint gaskets are most widely used in conditions that require high-temperature and high-pressure fluid flow, such as oil pipelines, gas pipes, pumps, valve joints, etc. The purpose of this study is to investigate the contact pressure and stress characteristics closely related to the sealing performance of Class 900 flange joints used in high temperature and high pressure environments. The dimensions of flange joints with five different nominal pipe sizes were determined with reference to those specified in ASME 16.5. The metal ring gaskets inserted in the joints were octagonal and oval gaskets. The bolt tensile forces calculated from the tightening torques were input as the bolt pretension loads in order to determine the contact pressure and stress levels after fastening. Loading was composed of three steps, including the fastening step, and different amounts of applied pressures were used in each analysis to investigate the effect of fluid pressure on the contact force of the joints. A general-purpose software, ANSYS 17.2, was used for the analysis.

Fire Resistance Performance of High Strength Concrete Columns with Fireproof Gypsum Board (방화석고보드를 부착한 고강도 콘크리트 기둥의 내화성능)

  • Youm, Kwang-Soo;Jeon, Hyun-Gyu
    • Journal of the Korea Concrete Institute
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    • v.22 no.2
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    • pp.229-235
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    • 2010
  • In this study, fire resistance performance of high strength concrete specimen with fireproof gypsum board was investigated for possible use in upgrading fire-resistant performance of the existing building and repair of fire damaged structures. Fire test of eight identical high strength concrete columns were carried out for 180 minutes in accordance with ISO-834. The temperature distributions in longitudinal reinforcement and concrete temperature at various depths were recorded. The fireproof performance of gypsum board and explosive spalling of concrete were observed. The specimens with 15 mm thick twoply fireproof gypsum board spalled after gypsum board crumbled regardless of fastening methods. However, when the thickness of fireproof gypsum board was more than 30 mm, it was possible to prevent the explosive spalling and control the rebar temperature. Although the effect of cover thickness could not be compared because the explosive spalling occurred, there seemed to be no difference in insulation efficiency.

An Evaluation of Tensile Design Criteria of Cast-In-Place Anchor by Numerical Analysis (수치해석에 의한 직매형 앵커기초의 인장설계기준 평가)

  • Suh Yong-Pyo;Jang Jung-Bum
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.18 no.3
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    • pp.303-309
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    • 2005
  • Numerical analysis is carried out to identify the appropriateness of the design codes that is available for the tensile design of fastening system at Nuclear Power Plant (NPP) in this study. This study is intended for the cast-in-place anchor that is widely used for the fastening of equipment in Korean NPPs. The microplane model and the elastic-perfectly plastic model are employed for the quasi-brittle material like concrete and for the ductile material like anchor bolt as constitutive model for numerical analysis and smeared crack model is employed to simulate the clack and damage phenomena. The developed numerical model is verified on a basis of the various test data of cast-in-place anchor. The appropriateness of both ACI 349 Code and CEB-FIP Code is evaluated for the tensile design of cast-in-place anchor and it is proved that both design codes give a conservative results for real tensile capacity of cast-in-place anchor.

Design Characteristics of New Senior Women's Coat (뉴 시니어 여성코트의 디자인 특성)

  • Bae, Siyeon;Lee, Kyoung-Hee
    • Fashion & Textile Research Journal
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    • v.17 no.2
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    • pp.157-167
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    • 2015
  • This study was initiated to understand design and detail characteristics of coats that targeted new senior women by analyzing shape, color, fabric and detail. For the new senior, youthful appearance has more appeal than products that represent elder's style. Among, the coat can be effectively utilized as a trendy fashion item that targets seniors since it is more useful to hide figures than pants, blouses or jackets. The objectives of this research were to: First, examine design characteristics of new senior women's coat. Second, understand design characteristics of new senior women's coat. Third, analyze the relationship between the design of collars and details according to type of new senior women's coat. Photographs collected were categorized according to type of coat. Three types of coat (balmacaan, redingote and trench) were chosen to analyze with the highest frequency. The results of analyzing shape, length, color and fabric of the products made in domestic and foreign brands were similar; however, the collar and way of fastening showed significant results that required specific analysis since the design elements were related to maincoat characteristics in protecting against the cold. The depth of the V-zone can change without change of collar width and design changes in V-zone that influence the coat image that lead to changes in sleeve type and length (or fastening and closing position) method.

A FINITE ELEMENT STRESS ANALYSIS OF THE STRESS DISTRIBUTION AND THE SHOCK ABSORPTION IN AN OSSEOINTEGRATED IMPLANT-NATURAL TOOTH SUPPORTED FIXED PARTIAL DENTURE (골유착성 임프란트와 자연치를 이용한 고정성 국소의치에서 응력분산 및 충격흡수에 관한 유한요소법적 응력분석)

  • Jeong Chang-Mo;Lee Ho-Yong
    • The Journal of Korean Academy of Prosthodontics
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    • v.30 no.4
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    • pp.582-610
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    • 1992
  • The long-term success of any dental implant is dependent upon the optimization of stresses which occur during oral function and parafunction. Especially, it has been suggested that there is an unique set of problems associated with joining an osseointegrated implant and a natural tooth with a fixed partial denture. For this particular case, although many literatures suggest different ways to avoid high stress concentrations on the bone surrounding the implant under static and dynamic loading conditions, but few studies on the biomechanical efficacy of each assertion have been reported. The purpose of this investigation was to evaluate the efficacies of clinically suggested methods on stress distribution under static load and shock absorption under dynamic load, using two dimensional finite element method. In FEM models of osseointegrated implant-natural tooth supported fixed partial dentures, calculations were made on the stresses in surrounding bone and on the deflections of abutments and superstructure, first, to compare the difference in stress distribution effects under static load by the flexure of fastening screw or prosthesis, or intramobile connector, and second, to compare the difference in the shock absorption effects under dynamic load by intramobile connector or occlusal veneering with composite resin. The results of this analysis suggest that : 1. Under static load condition, using an implant design with fastenign screw connecting implant abutment and prosthesis or increasing the flexibility of fastening screw, or increasing the flexibility of prosthesis led to the .increase in height of peak stresses in cortical bone surrounding the implant, and has little effect on stress change in bone around the natural tooth. 2. Under static load condition, intramobile connector caused the substantial decrease in stress concentration in cortical bone surrounding the implant and the slight increase in stress in bone around the natural tooth. 3. Under dynamic load condition, both intramobile connector and composite resin veneering showed shock absorption effect on bone surrounding the implant and composite resin veneering had a greater shock absorption effect than intramobile connector.

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A Suggestion of Sizing System for Developing Taekwondo Protectors (태권도 보호구 치수체계 제안)

  • Yi, Kyong-Hwa;Kim, Hye-Soo
    • Journal of the Korean Society of Clothing and Textiles
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    • v.32 no.9
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    • pp.1397-1406
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    • 2008
  • This research was to develop Taekwondo trunk protector(Hogu) and head protector's sizing systems corresponding the regulations by World Taekwondo Association. These sizing systems were established using 2003-2004 Size Korea anthropometric data. The result can be summarized as follows: According to the analysis of correlation, most measurements had high relationship with weight for Hogu and head girth for head protector. Six sizes(47, 54, 59, 64, 70, 76) for Hogu and 4 sizes(52, 54, 56, 60) for head protector were suggested in this study. Hogu sizes indicate body weights and head protector sizes express head girth measurements. By the comparison between current Hogu sizes and new sizes, the smaller sizes of new Hogu were bigger than current sizes in bust girth, back fastening length, shoulder length. On the other hand, the bigger sizes of new Hogu were larger than current sizes in bust girth, back fastening length, shoulder length. In addition, new Hogu's lengths were shorter than current Hogu in all sizes. The lengths of Neck to collar bone in new Hogu sizes were longer than current Hogu. In case of the head protector, there were no measurements besides outer circumference of helmet in recognized specifications of WTF. Therefore some referable measurements such as head girth, head length, bitragion arc, sagital arc were suggested in new size specification. When helmet sizes were suggested, the thickness of the NBR foam also were considered.

Bolt Loosening Analysis under Transverse Vibration for Design of Reliable Pyrotechnic Separation Nut (신뢰성 있는 파이로테크닉 분리 너트 설계를 위한 진동 시 볼트 풀림 해석)

  • Choi, Jae Young;Woo, Jeongmin;Kang, Dahoon;Kim, Jeong Ho;Cho, Jin Yeon;Jang, Seung-gyo;Yang, Hee Won
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.12
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    • pp.1004-1011
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    • 2018
  • Recently, pyrotechnic separation nut has attracted a considerable attention because of its shock reduction effect among various pyrotechnic mechanical devices. However, its bolt loosening behavior under transverse vibration has not been studied sufficiently, since segmented nuts are utilized instead of conventional nut in pyrotechnic separation nut. With the background, bolt loosening analyses are carried out referring to Junker vibration test. The analysis procedure consists of two steps. The first step is the bolt fastening step, screwing the bolt by fastening torque. The second step is the bolt loosening step under transverse vibration. Through the procedure, bolt loosening behaviors are obtained, and the effect of clearance on loosening behavior is closely investigated for reliable design of pyrotechnic separation nut.

A Comparative Study on Preference of the Korean Army's Flight Jacket According to Working Environment (근무 환경에 따른 육군 비행재킷의 선호도 비교 연구)

  • Choi, Hee Eun;Choi, Kueng-mi
    • Fashion & Textile Research Journal
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    • v.22 no.6
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    • pp.844-852
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    • 2020
  • This study is to understand the preferences of pilots, flight engineers and crew who work in the same aircraft but are exposed to different working environments and perform different mission operations in order to develop an ergonomic flight jacket. Based on a preliminary investigation, a survey of 107 pilots and 36 flight engineers and crew was conducted. The results are as follows; Pilots can control the temperature inside the cockpit, so they are less exposed to the cold when working, while flight engineers and crew are exposed to the cold more because they have many external tasks. The reason for the problem of the current flight jacket was a difference in ranking between two groups, but the highest ranking was poor dimensional suitability due to the habit of wearing layers of clothing. As a result of preferred design, there were significant differences between groups in the item of overall style. Pilots preferred a bomber jacket style(P:68.2%, E&C:44.4%), on the other hand, flight engineers and crew preferred a field jacket style(P:26.2%, E&C:55.6%)(p<.01). They preferred a stand collar(P:71.0%, E&C:86.1%), a fastener slider for a front fastening(P:62.6%, E&C:61.1%), fastener tape cuffs(P:54.2%, E&C:47.2%), a jacket with a softshell(P:86.9%, E&C:83.3%), fleece as softshell material(P:88.8%, E&C:69.4%), and fastener sliders as a attaching method(P:69.2%, E&C:61.1%). A hem fastening will be selected differently according to the overall style of outshell. Additionally, they preferred more than 5ea pockets(P:51.4%, E&C:44.4%), fastener sliders as pocket's fastenings(P:48.6%, E&C:61.1%), armpit ventilations(P:62.9%, E&C:58.5%). The results of above will be considered to design an ergonomic flight jacket.