• Title/Summary/Keyword: Assembly Structure

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The Current Status of Arrangement and the Direction of Rearrangement of the Archives Relating to the Korean Provisional Assembly (임시의정원 관련 기록물의 정리 현황과 재정리 방향)

  • Park, Dowon
    • The Korean Journal of Archival Studies
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    • no.73
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    • pp.161-188
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    • 2022
  • This article explores the current status of arrangement of the archives relating to the Korean Provisional Assembly held by the National Assembly Library and suggests the direction of rearrangement focusing on the principles of arrangement. The Korean Provisional Assembly had records management regulations, and records were produced and stored according to them. However, the archives lost their original order at some point. The National Assembly Library collected and managed them in the 1960s. The National Assembly Library did not fully consider the records management system at the time of record production and various situations that may occur during the storage process while organizing the collected archives. At that time, the National Assembly Library did not follow the records management regulations of the Korean Provisional Assembly. In addition, the hierarchical structure of archives was not applied during the arrangement, and the National Assembly Library arranged without considering the Principal of Provenance and the Principle of original order. As a result, it became difficult to understand the structure and context of the archives. In order to solve these problems and come up with a plan for rearranging the archives, first of all, it is necessary to examine the characteristics of the records related to the Korean Provisional Assembly in accordance with the principles of record arrangement. First, according to the Principal of Provenance, it is necessary to identify the organization, function, and records and classify the records item, records file, creators, dates of creation, types of records etc. Second, by applying the Principle of original order, it is necessary to understand what the order of records was at the time when records were created and preserved. Third, it is necessary to examine whether the records are completely created and valid. It is impossible to completely arrange the archives related to the Korean Provisional Assembly as it was in the past. However, by examining the current state of arrangement and the direction of rearrangement, it will be possible to newly understand the contents, structure, and context of the archives and create a basis for effective reference service.

Devising a Training Method for Assembly Work by Employing Disassembly

  • Ichikizaki, Osamu;Kubota, Ryou;Komori, Toshikazu;Matsumoto, Toshiyuki;Erikawa, Akihiro
    • Industrial Engineering and Management Systems
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    • v.12 no.4
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    • pp.368-379
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    • 2013
  • Efficiency in work training is a perennial issue due to high-diversity low-volume production, particularly for manufacturers producing office machines which are manually assembled by workers. To reduce the training cost, parts used in training are usually reused; a trainer disassembles a product assembled by a worker in training. This paper proposes a training method that employs disassembly usually performed by a trainer. This method assigns both assembly and disassembly to a worker in training, in contrast to the conventional method. The effectiveness of the proposed method is experimentally discussed in terms of learning assembly motions and work procedure at each learning stage, namely, "undergoing learning," "immediately after learning," and "seven days after learning." The effectiveness of the training method is confirmed. The method improves the stability of work procedure recollection immediately after training. Furthermore, at seven days after training, it improves retention of the assembly motions and work procedure, and also promotes and maintains memory related to product structure.

An Amplitude Comparison Direction-Finding Antenna Assembly for Mounting on a Small Flight Vehicle (소형 비행체 탑재를 위한 크기 비교용 방향 탐지 안테나 조립체)

  • Kim, Jaesik
    • Journal of the Korea Institute of Military Science and Technology
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    • v.23 no.5
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    • pp.459-465
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    • 2020
  • In this paper, a compact antenna assembly for an amplitude comparison direction-finding(DF) method for a small flight vehicle is presented. Designed antenna assembly consists of four antennas and it is mounted on a radius of 1.45 λc where λc corresponds to the wavelength of the center frequency. To achieve compactness and robustness of the assembly, the elements are fed by end-launch feeding method and have modified aperture shapes of E- or H-sectoral horns. The feeding part consists of SMA connector, stepped impedance matching structure, and square waveguide of 0.6 λc × 0.6 λc. To achieve different main beam directions for every antenna which is required condition for amplitude comparison DF method, all apertures of the antennas are inclined and it makes the main beam direction of each antenna to top, bottom, left, and right with respect to the axis of the platform. To verify the validation of DF performance of the presented antenna assembly, amplitude comparison curves using measurement results are presented. The bandwidth of the antennas are above 3.2 % in Ku-band(VSWR ≤ 2:1).

Preparation of Gold Nanoisland Arrays from Layer-by-Layer Assembled Nanoparticle Multilayer Films

  • Choi, Hyung-Y.;Guerrero, Michael S.;Aquino, Michael;Kwon, Chu-Hee;Shon, Young-Seok
    • Bulletin of the Korean Chemical Society
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    • v.31 no.2
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    • pp.291-297
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    • 2010
  • This article introduces a facile nanoparticle self-assembly/annealing method for the preparation of nanoisland films. First, nanoparticle-polymer multilayer films are prepared with layer-by-layer assembly. Nanoparticle multilayer films are then annealed at $~500^{\circ}C$ in air to evaporate organic matters from the films. During the annealing process, the nanoparticles on the solid surface undergo nucleation and coalescence, resulting in the formation of nanostructured gold island arrays. By controlling the overall thickness (number of layers) of nanoparticle multilayer films, nanoisland films with various island density and different average sizes are obtained. The surface property of gold nanoisland films is further controlled by the self-assembly of alkanethiols, which results in an increased surface hydrophobicity of the films. The structure and characteristics of these nanoisland film arrays are found to be quite comparable to those of nanoisland films prepared by vacuum evaporation method. However, this self-assembly/annealing protocol is simple and requires only common laboratory supplies and equipment for the entire preparation process.

Preliminary Study for the Reliability Assurance on Results and Procedure of the Out-pile Mechanical Characterization Test for a Fuel Assembly; Lateral Vibration Test(I) (핵연료 집합체 노외성능시험의 절차와 결과에 대한 신뢰성확보를 위한 예비고찰; 횡방향 진동특성시험(I))

  • Lee, Kang-Hee;Yoon, Kyung-Ho;Kim, Hyung-Kyu
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1854-1858
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    • 2007
  • The reliability assurance with respect to the test procedure and results of the out-pile mechanical performance test for the nuclear fuel assembly is an essential task to assure the test quality and to get a permission for fuel loading into the commercial reactor core. For the case of vibration test, which is carried out to obtain basic dynamic characteristics of the fuel assembly, proper management and appropriate calibration of instruments and devices used in the test, various efforts to minimize the possible error during the test and signal acquisition process are needed. Additionally, the deep understanding both of the theoretical assumption and simplification cation for the signal processing/modal analysis and of the functions of the devices used in the test were highly required. Finally, to verify the test result to represent the accurate natural characteristics of the structure, the proper correlation analysis between the theoretical and experimental method has to be carried out. In this study, the overall procedure and result of lateral vibration test for the fuel assembly's mechanical characterization were briefly introduced. A series of measures to assure and improve the reliability of the vibration test were discussed.

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A Multiobjective Process Planning of Flexible Assembly Systems with Evolutionary Algorithms (진화알고리듬을 이용한 유연조립시스템의 다목적 공정계획)

  • Shin, Kyoung Seok;Kim, Yeo Keun
    • Journal of Korean Institute of Industrial Engineers
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    • v.31 no.3
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    • pp.180-193
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    • 2005
  • This paper deals with a multiobjective process planning problem of flexible assembly systems(FASs). The FAS planning problem addressed in this paper is an integrated one of the assignment of assembly tasks to stations and the determination of assembly routing, while satisfying precedence relations among the tasks and flexibility capacity for each station. In this research, we consider two objectives: minimizing transfer time of the products among stations and absolute deviation of workstation workload(ADWW). We place emphasis on finding a set of diverse near Pareto or true Pareto optimal solutions. To achieve this, we present a new multiobjective coevolutionary algorithm for the integrated problem here, named a multiobjective symbiotic evolutionary algorithm(MOSEA). The structure of the algorithm and the strategies of evolution are devised in this paper to enhance the search ability. Extensive computational experiments are carried out to demonstrate the performance of the proposed algorithm. The experimental results show that the proposed algorithm is a promising method for the integrated and multiobjective problem.

Crash FE Analysis of Front Side Assembly for Reverse Engineering (승용차 프론트 사이드 조립체의 역설계적 유한요소 충돌해석)

  • Kim, Yong-Woo;Kim, Jeong-Ho;Jeong, Kyung-Shin
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.1
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    • pp.89-98
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    • 2007
  • Crashworthiness design is of special interest in automotive industry and in the transportation safety field to ensure the vehicle structural integrity and more importantly the occupant safety in the event of the crash. Front side assembly is one of the most important energy absorbing components in relating to the crashworthiness design of vehicle. The structure and shape of the front side assemblies are different depending on automakers. Thus, it is not easy to grab an insight on designer's intention when you glance at a new front side member without experiences. In this paper, we have performed the explicit nonlinear dynamic finite element analysis on the front side assembly of a passenger car to identify the mechanical roles of each part of the assembly and to enhance the absorbing energy from the viewpoint of reverse engineering.

Comparative study of the resistance of bonded, riveted and hybrid assemblies; Experimental and numerical analyses

  • Ezzine, M.C.;Madani, K.;Tarfaoui, M.;Touzain, S.;Mallarino, S.
    • Structural Engineering and Mechanics
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    • v.70 no.4
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    • pp.467-477
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    • 2019
  • The objective of this work is to analyze by traction tests, the mechanical behavior of an assembly of type metal / metal by various assembly processes; bonding, riveting and hybrid, on the one hand to show the advantage of a hybrid assembly with respect to the other processes, and on the other hand, to analyze by the finite element method the distribution of the stresses in the various components of the structure and to demonstrate the effectiveness of the use of a hybrid assembly with respect to other processes. The number of rivets has been considered. The results show clearly that the value of the different stresses is reduced in the case of a hybrid junction and that the number of rivets in an assembly can be reduced by using a hybrid joint.

Dynamic characteristics assessment of reactor vessel internals with fluid-structure interaction

  • Je, Sang Yun;Chang, Yoon-Suk;Kang, Sung-Sik
    • Nuclear Engineering and Technology
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    • v.49 no.7
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    • pp.1513-1523
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    • 2017
  • Improvement of numerical analysis methods has been required to solve complicated phenomena that occur in nuclear facilities. Particularly, fluid-structure interaction (FSI) behavior should be resolved for accurate design and evaluation of complex reactor vessel internals (RVIs) submerged in coolant. In this study, the FSI effect on dynamic characteristics of RVIs in a typical 1,000 MWe nuclear power plant was investigated. Modal analyses of an integrated assembly were conducted by employing the fluid-structure (F-S) model as well as the traditional added-mass model. Subsequently, structural analyses were carried out using design response spectra combined with modal analysis data. Analysis results from the F-S model led to reductions of both frequency and Tresca stress compared to those values obtained using the added-mass model. Validation of the analysis method with the FSI model was also performed, from which the interface between the upper guide structure plate and the core shroud assembly lug was defined as the critical location of the typical RVIs, while all the relevant stress intensities satisfied the acceptance criteria.