• International Journal of Automotive Technology
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• v.8 no.6
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• pp.731-744
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• 2007

A method for dynamic analysis and design calculation of a Powertrain Mounting System(PMS) including Hydraulic Engine Mounts(HEM) is developed with the aim of controlling powertrain motion and reducing low-frequency vibration in pitch and bounce modes. Here the pitch mode of the powertrain is defined as the mode rotating around the crankshaft of an engine for a transversely mounted powertrain. The powertrain is modeled as a rigid body connected to rigid ground by rubber mounts and/or HEMs. A mount is simplified as a three-dimensional spring with damping elements in its Local Coordinate System(LCS). The relation between force and displacement of each mount in its LCS is usually nonlinear and is simplified as piecewise linear in five ranges in this paper. An equation for estimating displacements of the powertrain center of gravity(C.G.) under static or quasi-static load is developed using Newton's second law, and an iterative algorithm is presented to calculate the displacements. Also an equation for analyzing the dynamic response of the powertrain under ground and engine shake excitations is derived using Newton's second law. Formulae for calculating reaction forces and displacements at each mount are presented. A generic PMS with four rubber mounts or two rubber mounts and two HEMs are used to validate the dynamic analysis and design calculation methods. Calculated displacements of the powertrain C.G. under static or quasi-static loads show that a powertrain motion can meet the displacement limits by properly selecting the stiffness and coordinates of the tuning points of each mount in its LCS using the calculation methods developed in this paper. Simulation results of the dynamic responses of a powertrain C.G. and the reaction forces at mounts demonstrate that resonance peaks can be reduced effectively with HEMs designed on the basis of the proposed methods.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1991.10a
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• pp.261-267
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• 1991

다품종소량생산의 특징을 갖고 있는 금형공업에서 컴퓨터통합생산시스템(Computer Integrated Manufacturing System;CIMS)의 실현을 위한 중요한 분야의 하나는 부품설계도면으로부터 최종제품을 생산하는데 필요한 공정계획의 자동화, 즉 컴퓨터를 이용하여 공정계획을 자동적으로 생성하는 자동공정계획시스템(Computer Aided Process Planning;CAPP) 기술의 개발이다. 국내외적으로 CAPP분야의 연구는 컴퓨터 지원에 의한 자동화 기술의 급속한 발전과 더불어 지난 20여년 동안에 기계가공품에 관한 CAPP은 약 150여가지가 개발되었으나, 이는 컴퓨터 지원에 의한 설계의 자동화(Computer Aided Design;CAD)나 컴퓨터 지원에 의한 제조의 자동화(Computer Aided Manufacturing;CAM)분야에 비해 상대적으로 저조한 형편이다. 특히 금형을 대상으로 한 CAPP시스템의 개발은 아직 초기단계에 있기 때문에, 본 연구에서는 사출금형을 대상으로 하여 실용성이 있는 공정설계시스템을 개발함을 목적으로 한다. 일반적으로 공정계획은 "소재로부터 제품을 경제적, 효율적으로 생산하는데 필요한 제조공정의 체계적인 결정"이라고 정의할 수 있다. 공정계획은 제품의 종류와 수량, 재료와 부품의 종류, 보유 생산설비와 제조기술의 수준에 따라 다르나, 공정설계(Process Design)와 작업설계(Operation Design)로 구분할 수 있다. 본 연구에서는 공정계획을 광의의 공정설계로 정의하고, 공정설계와 공정계획을 동의어로 통용토록 한다. 기존의 CAPP시스템의 개발에 관한 기본적인 접근방법은 변성형방법(Variant method), 창성형방법(Generative method) 및 자동화방법(Automatic method)이 있다. 이들 CAPP시스템을 개발할 때 사용하는 기법은 크게 5가지- (1) GT(group Technology) 접근기법, (2) Bottom-up 접근기법, (3) Top-down 접근기법, (4) AI와 전문가시스템(Expert System) 접근기법, (5) 컴퓨터 프로그래밍 언어 - 로 분류할 수 있다. 본 연구에서는 전문가시스템 기법을 도입해서 사출금형 공정계획전문가의 지식과 경험을 획득하여 지식베이스를 구축하고, 전문가시스템 셀(shell)중 CLIPS를 이용하여 자동공정계획시스템인 Mold CAPP을 개발하였다.PP을 개발하였다.

• Korean Journal of Construction Engineering and Management
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• v.6 no.2 s.24
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• pp.80-91
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• 2005

Although construction site photos contain important as_built information, technique and knowledge, there has been lack of frameworks to store and manage construction site photos efficiently and effectively. The problems in site photo management are getting increasingly serious, as digital cameras are adapted as collection tools of site Photos. This research suggests an information framework(named CIIM: Construction Image Information Model) to manage and share construction information based on 5W1H in order to derive construction context, which includes technologies, lessons-teamed and knowledge, from construction site photos, and a site photo management system named CIMS II (Construction Image information Management system II was developed to verify the model. It is expected that the results of this research that are an information framework and an system could help more effective classification, management, search and derivation of context in a construction project.

• Journal of the Society of Naval Architects of Korea
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• v.31 no.1
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• pp.42-49
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• 1994

The purpose of CIM for shipbuilding should be focused on the efficient processing of information among design, process planning and scheduling activities. The most essential technology for shipbuilding CIM is the product model. This model should not only define a physical product "ship" but also a process "ship production". Major activity for ship production is assembly, which requires intensive use of the relationships among parts of ship structure. Other production information are painting area. shape. weight, etc. The fact that major ship structure is "stiffened-plate" type, which allows us to handle the plate thickness as non-geometric information for practical purpose. Therefore. the geometric model for ship product model should handle the relationship among parts(so called topology) efficiently. We find that a face oriented non manifold data structure can meet this requirement. We apply this non-manifold data structure to the ship compartmentation, structural design, and assembly.

• Journal of Environmental Science International
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• v.18 no.6
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• pp.645-654
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• 2009

Lab-scale Electrodialysis(ED) system with different membranes combined with before or after pyroma process were carried out to remove nitrate from two pickling acid wastewater containing high concentrations of $NO_3\;^-$(${\approx}$150,000 mg/L) and F($({\approx}$ 160,000 mg/L) and some heavy metals(Fe, Ti, and Cr). The ED system before Pyroma process(Sample A) was not successful in $NO_3\;^-$ removal due to cation membrane fouling by the heavy metals, whereas, in the ED system after Pyroma process(Sample B), about 98% of nitrate was removed because of relatively low $NO_3\;^-$ concentration (about 30,000 mg/L) and no heavy metals. Mono-selective membranes(CIMS/ACS) in ED system have no selectivity for nitrate compared to divalent-selective membranes(CMX/AMX). The operation time for nitrate removal time decreased with increasing the applied voltage from 10V to 15V with no difference in the nitrate removal rate between both voltages. Nitrate adsorption of a strong-base anion exchange resin of $Cl\;^-$ type was also conducted. The Freundlich model($R^2$ > 0.996) was fitted better than Langmuir mode($R^2$ > 0.984) to the adsorption data. The maximum adsorption capacity ($Q^0$) was 492 mg/g for Sample A and 111 mg/g for Sample B due to the difference in initial nitrate concentrations between the two wastewater samples. In the regeneration of ion exchange resins, the nitrate removal rate in the pickling acid wastewater decreased as the adsorption step was repeated because certain amount of adsorbed $NO_3\;^-$ remained in the resins in spite of several desorption steps for regeneration. In conclusion, the optimum system configuration to treat pickling acid wastewater from stainless-steel industry is the multi-processes of the Pyroma-Electrodialysis-Ion exchange.

• Korean Security Journal
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• no.29
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• pp.139-162
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• 2011

The purpose of this study is to compare with the general and behavioral characteristics between simple and serial arsonists using the data derived from Scientific Crime Analysis System, Criminal Filing Search System, and Crime Information Management System. The analysis and findings reported here are derived from data extracted from 160 arsonists arrested by police officer. The independent variables included such socio-economic characteristic as arsonists' gender, age, occupation, education level, and previous criminal records of arsonists, and finally the general characteristics of the scene of fire settings. The dependent variable is whether or not serial fire setter. To achieve the purpose, the analysis of frequencies and cross-tab were conducted. According to frequence and cross-tab analysis, there are great differences of the general and behavior characteristics between two groups. In the comparison of simple and serial arsonists, serial arsonists are more likely to have previous criminal records, low socio-economic status, unmarried and no cohabitants than simple arsonists. furthermore, serial arsonists are more likely to use garbage papers for fire setting in the scene of the crime, to have mental or psychological problems, and to get involved in fire setting for the psychological pleasure than simple arsonists do. The present research has some obvious limitations. First, the analysis is based only on arsonists arrested by police officers. These may be considerable differences in arsonists arrested by police officers and fire setters not arrested by them. Additional research is needed to assess the extent to which these findings would apply to fire setters not arrested by police officer in Korea. Secondly, the data in this study are cross-sectional and simple cross-tab analysis are used. Potential limitation of cross-sectional data concerns the inability to specify the changes in measures as arsonists behavioral characteristics. Therefore, further studies need to use longitudinal data and more complicate statistical techniques such as correlation analysis, multiple regression analysis, or LISREL models to specify the casual relationships between dependent and independent variables for fire settings. Even if this study has some limitations, it is meaningful in which it first investigated the comparison of simple and serial arsonists focusing on the general and behavioral characteristics between two groups in Korea.