• Title/Summary/Keyword: Assembly Tool

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Assessment of Vibration Produced by Pneumatic Hand Tools Used in Automobile Assembly (자동차 조립공정에서 공기압력식 진동공구의 국소진동평가)

  • Kim, Sun Sul;Paik, Nam Won
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.6 no.1
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    • pp.1-16
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    • 1996
  • This study was conducted at an automobile assembly line located in Kyonggi-do, Korea from January 16 to February 28, 1995. The purposes of this study were to assess worker exposures to hand-arm vibration and the performance of gloves for reduction of vibration. The exposure to vibration was measured using to the ISO 5349(1986) method. Vibration acceleration and frequency spectra for each tool were determined on-line replicating actual working conditions and analyzed together with exposure time for evaluating individual worker exposure. Eight pneumatic hand tools, 60 workers exposured to hand-arm vibration, and three pairs of gloves were involved in this study. Results are summarized as follows. 1. Dominant frequencies of vibration for all tools(n=8) measured in this study ranged from 250 Hz to 800 Hz. 2. There was no significant correleration between dominant frequencies and free running speed (p>0.05). 3. Total predicted exposure times of using impact, hammer type did not exceed 40 minutes, but metal finish task, using grinder and sander exceeded 40 minutes. Total exposure time affected significantly the frequency-weighted, 4 hr equivalent acceleration. 4. Predicted prevalence and observed exposure period data were compared in workers(n=60), according to ISO 5349. In this results, 23(50.0 %) and 24(48.07 %) persons exceeded the mean latency periods for vibration-induced white finger(VWF) at 10 % (n=46) and 50 % (n=52) standards, respectively. On the basis of ISO equation, mean latent periods for VWF were 3.23, 4.72 years at 10 %, 50 % standards, respectively. 5. Reduction of vibration by gloves was evaluated. Since impact pneumatic tools produced low frequency vibrations, conventional gloves did not provide any protection. Gloves A and C amplify somewhat the signal at frequency below 400 Hz; the attenuation increases progressively by frequency to reach 18 dB ($7.94{\times}10^{-6}m/s^2$) at 1,000 Hz, slightly worsening Glove B did not provide any protection and made the situation slightly worse. However, since they make the hands warm, the occurrence of vibration-induced white fingers may be reduced.

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Design of Vision Based Punching Machine having Serial Communication

  • Lee, Young-Choon;Lee, Seong-Cheol;Kim, Seong-Min
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2430-2434
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    • 2005
  • Automatic FPC punching instrument for the improvement of working condition and cost saving is introduced in this paper. FPC(flexible printed circuit) is used to detect the contact position of K/B and button like a cellular phone. Depending on the quality of the printed ink and position of reference punching point to the FPC, the resistance and current are varied to the malfunctioning values. The size of reference punching point is 2mm and the above. Because the punching operation is done manually, the accuracy of the punching degree is varied with operator's condition. Recently, The punching accuracy has deteriorated severely to the 2mm punching reference hall so that assembly of the K/B has hardly done. To improve this manual punching operation to the FPC, automatic FPC punching system is introduced. Precise mechanical parts like a 5-step stepping motor and ball screw mechanism are designed and tested and low cost PC camera is used for the sake of cost down instead of using high quality vision systems for the FA. 3D Mechanical design tool(Pro/E) is used to manage the exact tolerance circumstances and avoid design failures. Simulation is performed to make the complete vision based punching machine before assembly, and this procedure led to the manufacturing cost saving. As the image processing algorithms, dilation, erosion, and threshold calculation is applied to obtain an exact center position from the FPC print marks. These image processing algorithms made the original images having various noises have clean binary pixels which is easy to calculate the center position of print marks. Moment and Least square method are used to calculate the center position of objects. In this development circumstance, Moment method was superior to the Least square one at the calculation of speed and against noise. Main control panel is programmed by Visual C++ and graphical Active X for the whole management of vision based automatic punching machine. Operating modes like manual, calibration, and automatic mode are added to the main control panel for the compensation of bad FPC print conditions and mechanical tolerance occurring in the case of punch and die reassembly. Test algorithms and programs showed good results to the designed automatic punching system and led to the increase of productivity and huge cost down to law material like FPC by avoiding bad quality.

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Systematic Review on Complementary and Alternative Medicine for Female Sexual Dysfunction (여성 성기능장애의 보완대체의학적 치료에 관한 논문 연구)

  • Jeong, Young-Min;Kim, Song-Baek;Choi, Chang-Min;Seo, Yun-Jung;Cho, Han-Baek
    • The Journal of Korean Obstetrics and Gynecology
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    • v.26 no.2
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    • pp.66-87
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    • 2013
  • Objectives: The aim of this study was to review systemically clinical trials on the trends of studies for Complementary and Alternative Medicine in the treatment of female sexual dysfunction and provide basic resource for future treatment and suggestions for improving research methods. Methods: Through medical website 'Pubmed', foreign clinical literatures about female sexual dysfunction were searched and domestic clinical literatures about female sexual dysfunction were searched using internet websites 'National assembly library', 'KISS', 'RISS', 'Korean traditional knowledge portal'. Results: Total 19 literatures were selected from January 2000 to June 2012. 15 foreign literatures were selected through medical website and 4 domestic literatures were chosen using internet websites or hand-searching. 5 literatures were published in 2008 and 13 literatures mentioned about age group of patients. FSFI is most common tool for female sexual dysfunction. 9 of 19 literatures were using Herbal medicine for treatment. 5 literatures were about CBT, 6 literatures were about Biofeedback and other one literatures are about Perineal massage. There were 14 Randomized controlled trials and 5 Non-randomized controlled trials. And randomized controlled trials were relatively low in risk of bias than non-randomized controlled trials. Conclusions: Upon these results, in similar future more clinical trials should be done and accumulate Evidence-based literatures.

Cognitive Development Evaluation of Haptic Puzzle Game Using a Haptic Pen (촉각펜을 이용한 햅틱 퍼즐게임의 인지 발달 평가)

  • Chung, Dong-Hun
    • Journal of Korea Game Society
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    • v.9 no.4
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    • pp.45-56
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    • 2009
  • It is necessary for young children to integrate the sense of sight, hearing, touch, etc. for developing their emotion and cognition. Thanks to Information and Communication Technology (ICT) development, young children have more opportunities to use various senses in learning process. However, ICT learning method is more focusing on the sense of sight and hearing, and lacks of integrated recognition and this fact leads to the reason why ICT can not be used as a main education tool. Therefore, this study evaluated the influence of wUbi-Pen(haptic device) on cognition using a computer puzzle program. The results show that young children using a haptic pen have greater intention and performance in object assembly, mazes, picture completion in K-WPPSI test than those of non-using haptic pen. This implies that haptic function should be considered in ICT material and indeed useful in various cognition-related symptoms and diseases.

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Cubical User Interface for Toy Block Composition in Augmented Reality (증강 현실에서의 장난감 블록 결합을 위한 큐브형 사용자 인터페이스)

  • Lee, Hyeong-Mook;Lee, Young-Ho;Woo, Woon-Tack
    • 한국HCI학회:학술대회논문집
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    • 2009.02a
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    • pp.363-367
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    • 2009
  • We propose Cubical User Interface(CUI) for toy block composition in Augmented Reality. The creation of new object by composing virtual object is able to construct various AR contents effectively. However, existing GUI method requires learning time or is lacking of intuitiveness between act of user and offered interface. In case of AR interfaces, they mainly have been supported one handed operation and it did not consider composition property well. Therefore, the CUI provide tangible cube as the manipulation tool for virtual toy block composition in AR. The tangible cube which is attached multi-markers, magnets, and buttons supports free rotation, combination, and button input. Also, we propose two kinds of two-handed composing interactions based on CUI. First is Screw Driving(SD) method which is possible to free 3-D positioning and second is Block Assembly(BA) method which support visual guidance and is fast and intuitive. We expected that proposed interface can apply as the authoring system for content such as education, entertainment, Digilogbook.

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Theoretical Study on the Effects of the Withdrawal Weighting on the Performance of Resonator Type SAW Filters (공진기형 SAW 필터에 위드로월 가중법이 미치는 효과에 대한 이론적 연구)

  • 이영진;이승희;노용래
    • The Journal of the Acoustical Society of Korea
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    • v.21 no.1
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    • pp.47-55
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    • 2002
  • This paper proposes a new improved lumped element equivalent circuit analysis method to analyze withdrawal weighted SAW resonators of irregular electrode configurations, which enables to calculate the frequency response of withdrawal weighted SAW resonators. This method has led to the derivation of Smith equivalent circuit's y-parameters for a single ground electrode and formulated the resonator's admittance by calculating the total current into an IDT assembly. To illustrate the effectiveness of the technique, this method was applied to the design of a simple ladder filter and the change of the filter performance was investigated in relation to the weighting of the series and parallel resonators, respectively. The results shows that the withdrawal weighted resonator ladder filters provide better performance in their bandwidth and transition characteristics than normal ones. This new equivalent circuit analysis method can also serve as a better tool to design and analyze general SAW resonator filters.

Modeling for Transparent Toaster with a Cap of Folding Type (폴더형 캡의 투명 토스터 모델링)

  • Kim, In-Ho;Kim, Ye-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.6
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    • pp.2013-2020
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    • 2010
  • This paper presents a study on the modeling for transparent toaster with a cap of folding type. The toaster was modelled to solve problems of customer's unsatisfaction such as heat loss, input of a piece of dirt, unidentified heating state of sliced toaster. Rapid prototyping was followed by the first modeling, and the second modeling was implemented in order to solve the problems of the first modeling such as interference of holder and door, and the third modeling was developed with a cap of folding type through analysis of assembly and simulation. The 3D modeling tool used in this paper was Pro/Engineer 4.0. The modeling was designed to minimize heat loss and structured with transparent outer case. So the toasting procedure will be identified with the naked eye, and the transparent toaster will improve the customer's aesthetic satisfaction.

A Study of the MC design application of modular construction Mainly on the MC design applying of discontinuous module grids (모듈러 건축의 MC 설계 적용에 관한 연구 불연속 모듈격자를 활용한 MC 설계를 중심으로)

  • Lee, Chang-Jae;Lim, Seok-Ho
    • KIEAE Journal
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    • v.13 no.6
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    • pp.121-128
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    • 2013
  • This study attempted to explore the MC design methods of modular construction using discontinuous double module grids and further, the design methods of walls. Modular construction is generally characterized with multiple units called modules with a module dimension of 3M(300mm) appearing in the form of double grids. The discontinuous double grids including correction values and gap values occurs inevitably in the modular construction where units are joined horizontally. Therefore, it is desirable to carry out the MC design taking into account these discontinuous double grids. In this study, the MC design was applied to the plane of wooden houses in modular construction, going through a process of setting the size of pillars and inside dimensions, of determining the dimension of discontinuous double grids that occur during the assembly of units, and of setting the dimension of outer walls in conjunction with the derived dimensions. The dimension of outer walls was applied differently depending on the range of regional use by analyzing the energy performance with the materials used. Consequently, the materials and components of factory-produced buildings can be used directly without processing, and the suitability of the outer wall design can be pre-determined by previewing the calculation of the cross-sectional configuration and heat transmission coefficients of outer walls in modular construction, allowing to be used as a decision-making tool of design.

Management system of thesis in university library (대학도서관의 석. 박사학위논문 관리체제)

  • 손문철
    • Journal of Korean Library and Information Science Society
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    • v.14
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    • pp.71-98
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    • 1987
  • After 1970s, because of an increasing peoples for higher education and graduate school-oriented education system, quantities of thesis were produced for short term and they began to be an important part of gift materials in university libraries. As an unpublished documents, thesis is narrow in subject, deep in content, irregular is page, incomplete in binding and produce limited-edition during short time simultaneously at most institutions. So most libraries are in difficulties for acquisition processing and circulation. Because of an increasing number of thesis will be produce and cutback of budget, shortage of staff, library service for user will be difficult and rational and efficient management is absolutely essential to library. In form and content, thesis is in distinction with other library materials, they must be handler as an independent item and library will seek an a n.0, ppropriate processing and using method of them. Analysis and synthesis of this study are summarized as follows. 1. In acquisition of thesis, it is desirable that they has an independent accession book with a simplified processing procedure and the binding of them is desirable together with subject field(major or department) by institutions. 2. In classification and cataloging of thesis, it is rational that library use the same classification scheme as other materials and expand in details. Simplified catalog will be reduce the time and/or personnel problem than using the traditional KCR or AACR. 3. As an retrieval tool, author, title, shelf and subject catalog must be prepared in thesis room. Index of thesis will be available for retrieval with the trend of union list and Korean periodicals index (National Assembly Library, Republic of Korea) must include the thesis. 4. Because of the nature and characteristics of thesis, library has to equip an independent room and open stack for the a n.0, ppropriate retrieval and frequent use. Qualified librarian must serve for the efficient circulation service.

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Construction of New P4-Derived Vector Plasmid Containing Tetracyclin Resistance Marker for the Bacteriophage P2-P4 System (박테리오파아지 P2-P4 시스템을 위한 tetracyclin resistance marker 함유 P4 유도체 벡터 플라스미드 조성)

  • Kim, Kyoung-Jin
    • Korean Journal of Microbiology
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    • v.39 no.2
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    • pp.118-122
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    • 2003
  • To develop vector plasmid for the bacteriophage P2-P4 system which is a useful experimental tool for the study of viral capsid assembly, we constructed a new P4-derived vector plasmid starting from P4 ash8 sid71 With recombinant DNA technology, a portion of P4 genome was deleted and tetracyclin resistance gene (terR) was introduced into P4 genome to give P4 selectivity. Resulting P4 ash8(sid71) terR was 12.09 kb long and could be converted to a viable bacteriophage with P2 infection. The burst size of induced bacteriophage form of P4 ash8(sid71) terR was determined. The CsCl buoyant equilibrium density gradient experiment of new P4 derivative suggested the upper limit of packaging capacity in P2-size head.