• Bulletin of the Korean Chemical Society
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• v.20 no.5
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• pp.573-576
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• 1999

The rate constants and kinetic solvent isotope effects (KSIE, KMeOH/kMeOD) for solvolyses of para-substituted phenylchloroformates in CH3OH, CH3OD, H2O, D2O, 50% D2O-CH3OD were determined at 15.0 and 25.0℃ using conductometric method. Kinetic solvent isotope effects for the solvolyses of para-substituted phenyl chloroformates were 2.39-2.51, 2.21-2.28, and 1.67-1.69 for methanol, 50% aqueous methanol, and water, respectively. The slopes of Hammett plot for solvolysis of para-substituted phenyl chloroformates in methanol, 50% aqueous methanol, and water were 1.49, 1.17 and 0.89, respectively. The Hammett type plot of KSIE, log (KSIE) versus p, can be a useful mechanistic tool for solvolytic reactions. The slopes of such straight lines for para-substituted phenyl chloroformates are almost zero in methanol, 50% aqueous methanol, and water. It was shown that the reaction proceeds via an associative SN2 and/or general base catalysis addition-elimination (SAN) mechanism based on activation parameters, Hammett p values, and slopes of Hammett type plot of KS-IE.

• Proceedings of the Technology Innovation Conference
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• 1996.12a
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• pp.27-62
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• 1996

As an exploratory attempt, this study examines the patterns of global R&D activities of industrial firms, focusing on the management of overseas R&D centers in terms of their location, primary missions, management style, organizational structure and communication and global human resource management system Based on a review of existing studies mainly undertaken in advanced countries and cases of foreign MNCs, several hypothetical relationships are postulated : 1) There appears a strong relationship between the purpose and location of R&D activities : 2) Different levels of global management and technological capability lead to different types of overseas R&D organizations : 3) The relationship between autonomy of overseas R&D organizations and their R&D performance will be moderated by organization size, development time pressure, and a need for internal efficiency : 4) Frequent communication between the headquarter and overseas R&D organizations will increase R&D performance 5) Mutual exchange of R&D professionals between the headquarter and overseas R&D organizations will be positively related with R&B performance. In addiction, this study explores the current state of global R&D activities of selective firms in Korea, based on ie-depth interviews, and analyzes the sources of problems in their global R&D management. Finally, theoretical and managerial implications of this study are discussed and future research directions are proposed.

• IE interfaces
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• v.12 no.2
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• pp.319-328
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• 1999

Today, offshore design field is concerned with system integration such as CIM(Computer Integrated Manufacturing), PDMS(Product Data Management System) and EDMS(Engineering Data Management System) in order to cope with the change of engineering specification as owner's requirements during construction stage of the project. This paper deals with the case study that describes about the efficient interface between material control system and 3D CAD system to support the design process in offshore industry using design rules involved the designer's knowledge. In this paper, we constructed an information system, called knowledge-based CAD interface systems, which is composed material code management system and 3D specification generator which automatically creates 3D catalogue anti specification by linking the material code, called short code, and the specification components of the 3D CAD system. As a result of the construction, it is possible to maintain consistency of the design process, and through reduction of the design processing time and improvement of the design process, competitiveness is improved.

• IE interfaces
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• v.8 no.3
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• pp.133-139
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• 1995

Free from curves and surfaces are frequently used in designing engineering products such as car, ship, airplane, and hosing of electronic households. In many aspect, it is very nice to use the cutter radius compensation function of CNC controller when contour machining a 2-dimensional curve. However, if the 2D curve is a parametric spline, it is not easy to apply the cutter radius compensation function of CNC controller to the NC data obtained from many commercial CAM system. This is mainly due to the error magnification effect when offsetting line segments with inevitable round-off error at their vertices. Proposed in this paper is an approach to contour machining a 2D parametric spline while using cutter radius compensation. Some implementation results are included.

• IE interfaces
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• v.18 no.1
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• pp.94-103
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• 2005

Digital Manufacturing is a technology to facilitate effective product developments and agile productions by digital environments representing the physical and logical schema and the behavior of real manufacturing system including manufacturing resources, processes and products. A digital factory as a well-designed and integrated environment is essential for successful applications of this technology. In this research, we constructed a sophisticated digital factory of an automotive company’ general assembly shop by measuring and 3-D CAD modeling using parametric methods. Specific parameters of each objects were decided by object-oriented schema of the general assembly shop. It is expected that this method is very useful for constructions of a digital factory, and helps to manage diverse information and re-use 3D models.

• Journal of the Korean Applied Science and Technology
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• v.25 no.3
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• pp.269-274
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• 2008

Anti-microbiological effects of xanthorrhizol, ie., extract from curcuma xanthorrhiza and extract from houttuynia cordata Thunb. against influenza virus and E. coli O157 were tested. From the influenza experiments, the effects were shown above 93 % in case of houttuynia cordata Thunb. extract, however, the effects was not shown in case of xanthorrhizol. The effects were sustained in mixtures of houttuynia cordata Thunb. and curcuma xanthorrhiza extracts. We also tested the anti-microbiological effects of hand sanitizer containing houttuynia cordata Thunb. and xanthorrhizol. The effect of hand sanitizer containing 2,000 ppm of xanthorrhizol and 500 ppm of houttuynia cordata Thunb. extract was better than that of commercialized foreign product.

• IE interfaces
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• v.14 no.2
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• pp.127-133
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• 2001

Virtual Manufacturing is a technology facilitating effective development and agile production of products via computer models representing physical and logical schema and the behavior of the real manufacturing systems. For the successful application of this technology, a virtual plant as a well-designed and integrated environment is essential. We propose a series of systematic approaches and effective methods for construction and operation of a virtual plant in this paper, such as a 3-D CAD modeling, cell and line simulations and databases. We developed key technologies for measuring and 3-D CAD modeling of many equipments, facilities and structures of the buildings. In order to study the benefit of virtual manufacturing, we constructed a sophisticated virtual plant model of a Korean automotive company's body shop, and conducted precise simulations of unit cell, lines and the whole plant. We could obtain the benefit of savings in time and cost in many manufacturing preparation activities in the new car development processes.

• IE interfaces
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• v.12 no.2
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• pp.205-209
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• 1999

In reverse engineering area, the reconstruction of surfaces from scanned or digitized data is being developed, but geometric model of existing objects is not available in industries. This paper presents the new approach to the reconstruction of surface technique. A proposed methodology finds base geometry and blends surface between them. Each based geometry is divided by tri-angular patches which are compared with their normal vector for face grouping. Each group is categorized analytical surface such as a part of cylinder, sphere and cone, and plane shapes to represent the based geometry surface. And then, each based geometry surface is implemented to the infinitive surface. Infinitive surface's intersections are trimmed by boundary representation model reconstruction. This method has several benefits such as time efficiency and automatic functional modeling system in reverse engineering. Especially, it can be directly applied 3D fax and 3D copier.

• IE interfaces
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• v.13 no.2
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• pp.157-165
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• 2000

In this paper, an efficient method is proposed to place the cooling lines(CLS) and ejector pins(EPS) of mold design. The other components of mold, except CLS and EPS, can be generated automatically by batch processing. But the placements and sizes of CLS and EPS depend on the shapes of a part, so that the design works of CLS and EPS should be processed interactively. Using the pre-defined reference points, the positions of CLS and EPS can be determined interactively. By the proposed method, the interference occurred during placing CLS and EPS can be avoided, and the proper lengths of them can be calculated automatically. The information of the positions and lengths are stored in BOM database for generating a machining data. The proposed method is implemented with Unigraphics API functions and C language, tested on Unigraphics V15.

• IE interfaces
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• v.7 no.3
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• pp.181-191
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• 1994

This paper presents an automatic conversion of machining data from the orthographic views of press mold by feature recognition rule. The system includes following 6 modules : separation of views, function support, dimension text check and feature processing modules. The characteristic of this system is that with minimum user intervention, it recognizes basic features such as holes, slots, pockets and clamping parts and thus automatically converts CAD drawing details of press mold into machining data using 2D CAD system instead of using an expensive 3D Modeler. The system is developed by using IBM-PC in the environment of AutoCAD R12, AutoLISP and MetaWare High C. Performance of the system is verified as a good interfacing of CAD and CAM when applied to a lot of sample drawing.