• Title/Summary/Keyword: VBA

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Automation of One-Dimensional Finite Element Analysis of a Direct-Connection Spindle System of Machine Tools Using ANSYS (ANSYS를 활용한 공작기계 직결주축 시스템의 1차원 유한요소해석 자동화)

  • Choi, Jin-Woo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.14 no.2
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    • pp.127-133
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    • 2015
  • In this study, an analytical model was developed for one-dimensional finite element analysis (1D FEA) of a spindle system of machine tools and then implemented to automate the FEA as a tool. FEA, with its vibration characteristics such as natural frequencies and modes, was performed using the universal FEA software ANSYS. VBA of EXCEL was used to provide the programming environment for its implementation. This enabled graphic user interfaces (GUIs) to be developed to allow interactions of users with the tool and, in addition, an EXCEL spreadsheet to be linked with the tool for data arrangement. The language of ANSYS was used to develop a code to perform the FEA. It generates an analytical model of the spindle system based on the information at the GUIs and subsequently performs the FEA based on the model. Automation helps identify the near-optimal design of the spindle system with minimum time and efforts.

Development of Sediment Discharge Computation System for Characteristic Analysis of River Sediment Discharge (하천유사량 특성분석을 위한 유사량산정시스템 개발)

  • Lee, Yeon-Kil;Go, Ju-Yeon;Lee, Jin-Won;Jung, Sung-Won
    • Proceedings of the Korea Water Resources Association Conference
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    • 2009.05a
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    • pp.723-727
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    • 2009
  • 본 연구에서는 유사량 측정의 적절성과 산정결과에 대한 정확성을 도모하고자 총유사량과 하상토유사량을 일관적으로 계산하고, 분석 및 관리할 수 있는 유사량산정시스템(Sediment Discharge Computation System; SDCS)을 개발하였다. 유사량산정시스템(SDCS)은 Microsoft사의 Excel VBA(Visual Basic for Applications)로 개발되어져 실행 및 분석이 간단 용이하고, 또한 유사량 산정결과를 저장하고 관리할 수 있는 DBFPAD가 내재되어 있다. 본 시스템은 크게 총유사량과 하상토유사량 산정 모듈로 구성되어 있어 각각의 모듈에서 유량규모에 대응하는 유사량과 농도를 산정할 수 있다. 총유사량 산정 모듈은 대표적인 확산-이송형 모형이라 할 수 있는 Modified Einstein 공식을 토대로 하였으며, 하상토유사량 산정 모듈은 Einstein, Ackers & White, Engelund & Hansen, Yang의 유사량 공식을 근간으로 되었다. 본 시스템은 크게 총 5개의 모듈을 가지며, 총 20개의 부프로그램(Subroutine Program)과 23개의 사용자정의함수 구문으로 개발되었다. 또한 단면의 특성변화 분석모듈과 DBFPAD 저장 및 관리모듈이 포함되어 있어 산정된 결과를 용이하게 비교 분석할 수 있고, 기존 자료와의 비교도 쉽게 수행할 수 있도록 구성하였다.

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THE STUDY OF OPTIMAL BUFFER ALLOCATION IN FMS USING GENETIC ALGORITHM AND SIMULATION

  • Lee, Youngkyun;Kim, Kyungsup;Park, Joonho
    • Proceedings of the Korea Society for Simulation Conference
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    • 2001.10a
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    • pp.263-268
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    • 2001
  • In this paper, we present a new heuristic algorithm fur buffer allocation in FMS (Flexible Manufacturing System). It is conducted by using a genetic algorithm and simulation. First, we model the system by using a simulation software, \"Arena\". Then, we apply a genetic algorithm to achieve an optimal solution. VBA blocks, which are kinds of add-in functions in Arena, are used to connect Arena with the genetic algorithm. The system being modeled has seven workstations, one loading/unloading station, and three AGVs (Automated Guided Vehicle). Also it contains three products, which each have their own machining order and processing times. We experimented with two kinds of buffer allocation problems with a proposed heuristic algorithm, and we will suggest a simple heuristic approach based on processing times and workloads to validate our proposed algorithm. The first experiment is to find a buffer profile to achieve the maximum throughput using a finite number of buffers. The second experiment is to find the minimum number of buffers to achieve the desired throughput. End of this paper, we compare the result of a proposed algorithm with the result of a simple buffer allocation heuristic based on processing times and workloads. We show that the proposed algorithm increase the throughput by 7.2%.t by 7.2%.

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Joint Connection of Stage-Discharge Rating Curves by Cubic Spline (3차 스플라인을 이용한 수위-유량관계곡선의 접점 연결)

  • Lee, Chang-Hae;Jang, Suk-Hwan
    • Proceedings of the Korea Water Resources Association Conference
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    • 2008.05a
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    • pp.199-203
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    • 2008
  • 수위관측지점의 수위-유량관계는 하천단면 형태와 경사에 따라 1개의 유량곡선이 형성될 수도 있으나, 저수위, 평수위, 고수위 등 여러 개 구간의 곡선이 각각 다른 형태로 구성될 수 있다. 또한 이러한 곡선의 연결접점에서 연결이 연속적이어야 하고 부드러워야 한다고 알려져 있다. 각 수위구간에서 유도된 수위-유량관계곡선이 수위구간을 나눈 경계수위에서 곡선식이 일치하지는 경우가 종종 나타난다. 본 연구에서는 경계수위와 곡선접점이 일치하는지 여부를 판단하고 오차의 크기를 확인하기 위하여 할선법을 적용하여 Excel의 VBA로 프로그램을 작성하여 사용하였다. 한편, 수위유량곡선의 연결부에서 부드럽게 연결되는 것이 바람직 하지만, 지금까지 실무에서는 경계수위에서 기울기가 급변하는 형태의 수위-유량관계곡선을 사용하고 있다. 왜냐하면 최소자승회귀분석을 통하여 유도되는 과정에서 경계수위지점의 1차 도함수를 일치시키는 것은 현실적으로 불가능하기 때문이다. 본 연구에서는 이러한 문제를 해결하기 위하여, 회귀분석으로 지수함수의 형태로 유도된 수위-유량관계곡선으로부터 수위와 유량의 대표 값을 계산하고 이들 대표 값들을 3차 스플라인 보간법을 이용하여 1차 도함수를 접점에서 일치시키는 부드러운 연결과 함께 수위-유량관계곡선과도 잘 일치하는 새로운 대안을 제시하였다. 2006년도 한국수문조사연보(유량편)의 자료를 검토하여 문제점들을 도출하고, 본 연구에서 제안한 방법들을 적용하여 보았다.

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Implementation of Creating Smart Pattern System for Hand Made Suit (맞춤 정장을 위한 스마트 패턴 생성 시스템 구현)

  • Choi, Gi-Rak;Kang, Nam-kyu;Lee, Jong-Hyeok
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.05a
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    • pp.859-862
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    • 2015
  • Recent fashion business, is to promote and make a business strategy to realize a high added value to the first goal. Completion of the best men's clothing is only by making the pattern through a person's body size, making it as the best dressed. In this paper, we propose a system to automate production processes a significant impact on menswear production process, time and cost reduction in order to satisfy the needs of manufacturers and customers. Consequently, it is possible to provide optimal men's clothing by saving a time and expense of customers by, increases the customer's needs and men's clothing demand, it is possible to more easily perform to franchising custom men's clothing manufacturer.

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An Economic Analysis of Ice Thermal Storage and Absorption Chiller-Heater Systems (빙축열 시스템과 흡수식 냉온수기 공조 방식의 경제성 분석)

  • Lim, Hyun-Woo;Kim, Young-Il;Kim, Kang-San;Kang, Yong-Tae
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.218-223
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    • 2009
  • Cost related to building equipment accounts for about 85% of the life cycle cost of buildings. Therefore proper selection of air-conditioning system is important for reducing the overall cost of buildings. In this study, large capacity ice thermal storage and absorption chiller-heater for air-conditioning a building with a floor area of $9,900\;m^2$ are compared economically. For easy input and analysis, an Ms Excel VBA program has been developed. To consider all the factors of initial and operation costs effectively, an annual equal payment method is proposed. Under the assumptions made in this study, overall cost of an absorption chiller-heater is less than that of an ice thermal storage, but this is not absolute and different outcome may result if different assumptions are made. This study is useful for those who are interested in choosing an economical air-conditioning system for large-size buildings with simple calculations.

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Computational Study of the Shr oud Shape & the ProBeller Fan (Shroud 형상에 대한 해석적 연구 및 '프로벨러 홴' 소개)

  • Han, Jae-Oh;Yu, Seung-Hun;Mo, Jin-Yong
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.638-641
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    • 2008
  • Computational investigation was conducted to study the effects of the shape parameter of shroud on the performance of the outdoor unit of an air-conditioners. For this study the Design of Experiment(4-factor 3-level) was created and the an automatic program was composed using VBA to reduce the load of pre-process for CFD. The estimated mathematical equation was produced from this analysis and it was found that the gap between fan and shroud affects more heavily than the other parameters. As a result, the composition of the best parameters was verified that its flow rate was increased by 10 percents and sound pressure level was reduced by 1.2 dBA compare with the worst. And finally, a kind of Propeller fan with blades which were attached to the shroud, so-called 'ProBeller Fan' was introduced in this study.

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Development of BIM Based Information Model Interface Module for a Modular Pier (모듈러 교각의 BIM 기반 정보 모델 인터페이스 모듈 개발)

  • Kim, Dong-Wook;Lee, Kwang-Myong;Nam, Sang-Hyeok
    • Journal of KIBIM
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    • v.5 no.1
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    • pp.1-7
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    • 2015
  • Modular technology has become a major issue of the construction industries to enhance their productivity. Modular bridge construction generally requires the data exchange between the contractors, designers, fabricators and constructors. Therefore, a readily accessible information model interface module based on BIM technology is essential for their communication during a project life-cycle. In this study, BIM based information model interface module for a modular pier was developed. For the information models, the PBS(Product Breakdown Structure) and LOD(Level of Development) were defined. Next, all components of a modular pier were conducted by the parametric modeling technique, and then 3D cell library interface was developed. An nterface module was also developed using VBA(Visua basic Application) for exchanging a data from 3D model library to other softwares such as Microstation, AutoCad and Excel and was connected with MS Access database. The developed information model interface module would improve the design quality of the modular pier and reduce the time and cost for design. Updated 3D information models could be utilized for the fabrication, assembly, and construction process for modular piers.

Effect of Pottery Containing Antimicrobial Materials on Shelf life of Beef Meat (항균성 물질이 첨가된 도자기가 우육의 저장성에 미치는 영향)

  • 최태현;정인천
    • Journal of the East Asian Society of Dietary Life
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    • v.10 no.6
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    • pp.507-513
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    • 2000
  • This study was conducted to investigate the shelf life of beef stored in antimicrobial pottery during 12days storage at 4'C and Five kinds of antimicrobial potteries were prepared with antimicrobial materials such as TiO$_2$, Ag (NO$_3$)$_2$, Cu(NO$_3$)$_2$ and Zn(NO$_3$)$_2$. In changes of color during storage, Hunter's L- and b-value of beef were not changed, but Hunter's a-value was low significantly. The pH of beef meats were low at 6 days, but were added from 6 days. TBA value of beef in "A" pottery containing TiO$_2$ 1% and "C" Pottery containing TiO$_2$ 0.5%, Cu(NO$_3$)$_2$ were lower than "B", "D" and "I" pottery. VBN contents of beef in "A", "B", "C", "D" and "I" Pottery stored during 12 days were 9.8, 12.5, 9.3, 11.9 and 13.7mg%, respectively. In changes of total plate count of beef during storage at 4$^{\circ}C$, the antimicrobial activity of "A" and "C" pottery were superior.g storage at 4$^{\circ}C$, the antimicrobial activity of "A" and "C" pottery were superior.ttery were superior.

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Facilitating the Usage of Value Management Processes by Charactering Capital Facility Projects

  • Cha Hee Sung
    • Korean Journal of Construction Engineering and Management
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    • v.5 no.2 s.18
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    • pp.144-152
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    • 2004
  • Defining value as a measure of how well the project value objectives are met, Value Management Process (VMP) is considered to be any management effort or process that can proactively pursue one or more project objectives (i.e., security/safety, cost effectiveness, schedule optimization, and risk containment). The collection of 44 VMPs has been established based on a rigorous effort conducted by Construction Industry Institute (CII). Because varying circumstances on each project determine the level of suitability, it is crucial to identify which VMP should be implemented on a particular project. The current VMP selection process is primarily based on human intuition. The main objective of this paper is to provide a systematic method to facilitate the usage of VMPs on a particular project. This paper identified and quantified the selection principles (i.e., targeted value objectives, timing of initiation, project characteristics, and relative impact). The data collected from industry practitioners and VMP experts characterized each VMP in terms of the magnitude of benefit. An automated selection tool by Visual Basic Application (VBA) on MS Excel TM, was developed and proved its validity. As a pioneering study, this paper provides a comprehensive and structured knowledge on the subject of VMPs. From the industry's perspective, the automated selection tool, the premier of this study, contributes the facilitation of the VMP implementations in the construction industry thereby maximizing the potential benefits to a particular project.