• Title/Summary/Keyword: Special tools

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EFFICIENT SCREWING : last developments and Korean experience

  • Ines MEYUS;Maurice Bottiau;Myung-Whan Lee;Jong-Bae Park;Yong-Boo Park
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.405-414
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    • 1999
  • The auger and screw piles have known an important evolution during the last decade. Besides the large success of augercast (CFA) piling systems, new systems have been developed combining, to a variable extent, the classical extraction auger with especially designed displacement tools in order to develop screw piles with partial or total lateral soil displacement. These last developments cover the whole range of lateral soil displacement and are more difficult than ever to compare. The authors present the latest evolutions in auger piling systems and compare them with respect to penetration performances, bearing capacities and amount of spoil generated. A special focus is given to a new efficient system: the OMEGA(H) pile in use in Korea since 1997. The results of the Hongcheon site are presented where this R system was applied for a new investment of the Korean National Housing Corporation (KNHC). This first important experience, with the execution of some 1,500 Omega piles with diameter 410 mm, is presented. The piles were installed through loose silty sands down to very dense sands and layers of gravel. The results of full-scale load tests are analysed and show the conformity with requirements of the clients.

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The Launch Operation Sequence through Remote Control of Bogie (보기 원격제어를 통한 발사 운용과정)

  • Lee, Chang-Bae;Seo, Jin-Ho;Lee, Soo-Jin;Chung, Eui-Seung
    • Aerospace Engineering and Technology
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    • v.7 no.2
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    • pp.144-150
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    • 2008
  • Bogie(The Launch vehicle transporter) is the special land transportation vehicle for the LV (Launch vehicle) which is used for not only the transportation-means of LV from LVAB(Launch Vehicle Assembly Building) to LP(Launch Pad) but also one of principal tools for launch operation sequence. Due to the multi-role of Bogie, The technical requirements of bogie are very complicated. Especially launch operation has performed with not only bogie but also many ground support equipments. So, it is impossible to establish technical requirements of bogie without whole understanding of launch operation. This paper was made for arranging whole launch operation sequence and technical requirements of bogie based on the this sequence.

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A study on the demands of dental hygiene students on extracurricular programs, according to learning style (치위생과 재학생의 학습유형에 따른 비교과 교육에 대한 수요 비교)

  • Kim, Myung-Eun;Kim, Hee-Kyoung
    • Journal of Korean society of Dental Hygiene
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    • v.19 no.6
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    • pp.1047-1058
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    • 2019
  • Objectives: The aim of this study is to investigate extracurricular program needs according to the learning styles of dental hygiene students, and to develop and organize non-subject programs that strengthen student competencies. Methods: The subjects in this study were dental hygiene students from three colleges located in Chungbuk, Chungnam, and Ulsan, respectively. The survey tools were composed of learning style, a non-subject field, and non-subject teaching and learning methods. Lastly, 313 data points were analyzed. Results: Learning styles of subjects were as follows: assimilators, divergers, convergers, and accommodators, at 44.6%, 33.0%, 16.0%, and 6.4%, respectively. Preference of the non-subject field, according to learning style, showed that accommodators were higher than divergers on startup, and the difference was found to be statistically significant (p<0.05). Preference of non-subject teaching and learning methods, according to learning style, shows that both divergers and convergers prefer special lectures, while assimilators prefer tours, and convergers prefer experience/exercise. The results had achieved statistical significance (p<0.05). Conclusions: This study shows that dental hygiene students had different learning styles, and their learning methods varied depending on learning style. Therefore, a method should be identified to develop and run non-subject programs suitable for each learning style.

Submasseteric Abscess (깨물근하 농양)

  • Ha, Young In;Park, Eun Soo
    • Archives of Plastic Surgery
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    • v.34 no.6
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    • pp.799-802
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    • 2007
  • Purpose: The masserteric space is an important tissue compartment of the face, but a disease in it is difficult to diagnose and treat. The submasseteric abscess is located between the masseter muscle and mandibular ramus with different appearances such as sepsis, infection, or tumor. Especially the common misdiagnosis of submasseteric abscess is acute or chronic parotitis. The purpose of this report is to pay special attention to the possible diagnosis of submasseteric abscess for the symptoms of unilateral cheek swelling and tenderness that accompany marked trismus. Methods: A 11-year-old boy came to our hospital because of facial swelling, tenderness, and trismus in a history of left cheek swelling and toothache. We diagnosed his case as submasseteric abscess by CT scan and surgical intervention was performed. Under general anesthesia, the abscess was opened by the intraoral incision and considerably massive pus was drained. Results: Swelling, tenderness, and trismus became to subside during postoperative 10 days and general condition and vital signs became stable. After 6 months, CT scan showed that both masseteric muscles were symmetric and there was no periosteal reaction of the mandible. Conclusion: In conclusion, submasseteric abscess is a rare infection with the symptoms of cheek tenderness and marked trismus. A detailed medical history and clinical examination of a patient as well as computed tomography(CT) are important tools in the accurate diagnosis and efficient treatment of the submasseteric abscess. Adequate drainage, removal of cause, and antibiotic infusion are the management of choice.

Six Sigma in Non-Manufacturing Environments

  • Akpolat, Hasan
    • International Journal of Quality Innovation
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    • v.5 no.2
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    • pp.17-25
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    • 2004
  • Despite the fact that much has been published about Six Sigma in the business and academic press and on the Internet in recent years, there is still confusion among many people, particularly those who work in the transactional and service environments, about the nature of Six Sigma. It is true that Six Sigma like other process improvement programs before was first applied to manufacturing processes; however, many corporations including General Electric and Sony have successfully applied Six Sigma to their transactional and service processes as well. Six Sigma is used by many companies not only to improve the quality of their products and services but also to achieve quantifiable financial results, improve management style and communication, and achieve customer and employee satisfaction. Whether in manufacturing or non-manufacturing environments, the application of Six Sigma differs from organization to organization. Although there are many common elements between these applications, however, special care must be taken when customizing Six Sigma to suit the organizations' needs. In this paper, the author provides some practical and useful guidelines for Six Sigma deployment. This paper is not about the use of numerous statistical tools and techniques that can be found in a typical Six Sigma toolbox. The main emphasis has been placed both on the concept and the implementation of Six Sigma, particularly within the non-manufacturing areas of business.

Neutron Streaming and PWR Cavity Shielding Design

  • Kim, Kyo-Sool;Lee, Chang-Kun
    • Nuclear Engineering and Technology
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    • v.12 no.2
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    • pp.127-134
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    • 1980
  • Shielding problems associated with neutron streaming through the reactor vessel cavity of pressurized water reactors are discussed to a certain extent with the actual examples in the currently operating reactors. Various remedial techniques are proposed herein to mitigate the tedious neutron streaming phenomena including piling up in heaps of temporary boron-containing bags and the installation of permanent shield structure making use of a certain refractory materials. In conclusion, optimum cavity shielding design concepts are presented with special emphasis on such major factors as the identification of major neutron streaming path, selection of necessary shielding materials with acceptable constraints, detailed design characteristics and physical configuration as well as the formulation of dependable mathematical tools to predict the final outcome of each design concept proposed in the context.

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A Dynamic Behavior of Rubber Component with Large Deformation (대변형을 하는 고무 부품의 동적 거동)

  • Cho Jae-Ung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.6 no.6
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    • pp.536-541
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    • 2005
  • Large displacement and rigidity about rubber component are expected by nonlinear and large deformation analysis in this study. Rubber is also used by the model of Mooney-Rivlin and the self contact between rubbers is established. There is the friction between rigid body and rubber, wall and floor. The nonlinear simulation analysis used in this study is expected to be widely applied in design, analysis and development of several rubber components which are used in automotive, railroad, and mechanical elements etc. By utilizing this method, time and cost can also be saved in developing new rubber product. The analysis of rubber components requires special material modeling and non-linear finite element analysis tools that are quite different from those used for metallic parts. The objective of this study is to analyze the rubber component with large deformation and non-linear properties.

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Development of Optimum Shape Forming Technology of Angle Ring and Cap for 154 kV Transformer Insulation (154 kV급 변압기 절연물 앵글링과 캡의 최적성형 기술 개발)

  • Suh, Wang-Byuck;Kim, Jong-Won;Ryu, Jung-Soo;Bae, Dong-Ho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.23 no.11
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    • pp.880-885
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    • 2010
  • The Angle Ring and Cap which is called pressboard are settled at the primary and secondary coil winding of 154 kV transformer that can reduce effectively distance of insulation. As it has not manufactured pressboard of Angle Ring and Cap for high voltage grade, insulation components industry especially high voltage transformer has not participate in a competition with worldwide yet. That's why is difficult to make an specialized shape of insulation components of high voltage grade. Therefore it has finally completed to make an deformation manufacturing utility using an bellowed special analysis tools. This study that uses various analysis program determining optimum shape about insulation of Angle Ring and Cap which is related life of high voltage transformer. In addition to develop forming equipment with an specialized five steps pressing. That is also based on the mechanical strength evaluation and test, it is investigated optimized processing components.

Strength Characteristics and Non-Destructive Evaluation of Composites with Heat Damage (국부열손상을 받은 복합재료의 강도특성 및 비파괴평가)

  • Nam, Ki-Woo;Kim, Young-Un
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2002.05a
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    • pp.173-178
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    • 2002
  • Fourier transform has been one of the most common tools to study the frequency characteristics of signals. With the Fourier transform alone, it is difficult to tell whether signal's frequency contents evolve in time or not. Except for a few special cases, the frequency contents of most signals encountered in the real world change with time. Time-frequency methods are developed recently to overcome the drawbacks of Fourier transform, which can represent the information of signals in time and frequency at the same time. In this study, heat damage process of a carbon fiber reinforced plastic(CFRP) and glass fiber reinforced plastic(GFRP) under monotonic tensile loading was characterized by acoustic emission. Different kinds of specimens were used to determine the characteristics of Strength and AE signals. Time-frequency analysis methods were employed for the analysis of fracture mechanism in CFRP such as matrix cracking, debonding and fiber fracture.

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5-Axis CNC Machining for Drum Cam with Rotational Follower - II (Post Processing Method for Fine Machining) (회전형 종동절을 갖는 드럼 캠의 5-축 CNC 가공 - II (정삭가공을 위한 포스트프로세싱))

  • Cho, Hyun-Deog;Yoon, Moon-Chul;Kim, Kyung-Jin
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.5
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    • pp.684-690
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    • 2010
  • A drum cam with rotational follower has a cam mechanism and it is mainly used in its application such as index table and ATC of machine tool. Also its use can reduce the backlash in its kinematic movement. To machine the drum cam with rotational follower, 5-axis CNC machine tool is generally used and its kinematic principle is included in it's design. Until now, the commercialized CAM software can't cover the application of the drum cam machining. Even if, some special software was developed for machining a drum cam, the post processing method for finish machining was not developed yet. And to overcome the problem, the form tool is still used on the tool path of rough machining. This study includes the induction of the post processing technique for the finish machining of drum cam on three 5-axis CNC machine tools, type AC, AB and BC. To prove the finishing geometric profile, the result was clearly verified through inspection and geometric measurement after direct machining of the drum cam in AC type 5-axis machine tool in this study.