• Journal of the Korean Society for Precision Engineering
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• v.31 no.7
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• pp.605-613
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• 2014

Scanning white-light interferometry is an important measurement option for many surfaces. However, serious profile measurement errors can be present when measuring free-form surfaces being highly curved or tilted. When the object surface slope is not zero, the object and reference rays are no longer common path and optical aberrations impact the measurement. Aberrations mainly occur at the beam splitter in the interference objective and from misalignment in the optical system. Both effects distort the white-light interference signal when the surface slope is not zero. In this paper, we describe a modified version of white-light interferometry for eliminating these measurement errors and improving the accuracy of white-light interferometry. Moreover, we report systematic errors that are caused by optical aberrations when the object is not flat, and compare our proposed method with the conventional processing algorithm using the random ball test.

• Korean Journal of Computational Design and Engineering
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• v.12 no.1
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• pp.8-14
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• 2007

In the product design process computer-aided engineering and optimization tolls are widely utilized in order to reduce the total development time and cost. Since several simulation tools are involved in the process, information losses, omissions, or errors are common and the importance of seamless information exchange among the tools has been increased. In this work, ISO STEP standards are adopted to represent the neutral format for structural analysis and optimization. The schema of AP209 defined the information of finite element analysis is used and the new schema is proposed to describe the information of structural optimization based on the STEP methodology. The schema is implemented by EXPRESS, information modeling language, and ST-Developer is employed to generate C++ classes and STEP Rose Library by using the schema denoted. To substantiate the proposed approach, the information access interfaces of the finite element modeling software (FEMAP), structural optimization software(GENESIS) and in-house topology optimization program are developed. Examples are shown to validate the information exchange of finite element analysis and structural optimization using STEP standards.

• Journal of the Korean Professional Engineers Association
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• v.32 no.3
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• pp.92-105
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• 1999

With the advent of the information age and the knowledge-based society, human resource development has become a key factor in determining a nation's competitiveness. And technological qualification systems have a direct and significant influence on human resource development. In order to guarantee Korea's continued development as a competitive member of the international community, it is demanded that a Korean Technology Qualification System (KTQS) is to accept international qualification criteria. This study was conducted in order to analysis current movements about the international mutual recognition of Professional Engineer and present problems for introducing APEC Engineer System to KTQS, and also recommend reasonable plans which overcome those. Under the WTO/GATS, the liberalization of trade in professional services will steadily increase. APEC activities to facilitate the portability of qualifications is considered complementary to the WTO movement. If the government attempts to introduce the APEC criteria for university degree requirements, university curriculum standards, programs for continuing professional developments(CPD), and practical, on-site experience. In the standpoints with the recent developments of APEC Engineer agreement on profession qualification, it is important to guarantee that Korean qualifications have a common, international currency. Measures have to be taken to harmonize the qualifications standards for Professional Engineer with those set out by the WTO/GATS movement. Also this will require an increase in the quality of university curriculum and an establishment of CPD. This process will be further enhanced by the organization of APEC Engineer Monitoring committee, Consisting of government officials, professional engineers and university professors. At this committee we can discuss the best strategies to keep our nation's interests.

• International Journal of Precision Engineering and Manufacturing
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• v.1 no.1
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• pp.62-70
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• 2000

The design of gear train is a kind of mixed problems which have to determine various types of design variables; i,e., continuous, discrete, and integer variables. Therefore, the most common practice of optimum design using the derivative of objective function has difficulty in solving those kinds of problems and the optimum solution also depends on initial guess because there are many sophisticated constrains. In this study, the Genetic Algorithm is introduced for the optimum design of gear trains to solve such problems and we propose a genetic algorithm based gear design system. This system is applied for the geometrical volume(size) minimization problem of the two-stage gear train and the simple planetary gear train to show that genetic algorithm is better than the conventional algorithm solving the problems that have continuous, discrete, and integer variables. In this system, each design factor such as strength, durability, interference, contact ratio, etc. is considered on the basis of AGMA standards to satisfy the required design specification and the performance with minimizing the geometrical volume(size) of gear trains

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.2
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• pp.121-138
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• 1999

This study was carried out to evaluate the performance of a sampling and analytical methodology for the measurement of selected volatile organic compounds (VOCs) in the ambient air. VOCs were determined by the adsorbent tube sampling and automatic thermal desorption coupled with GC/FID and GC/MSD analysis. Target analytes were aromatic VOCs, including BTEX, 1,3,5-and 1,2,4,-trimethylbenzenes(TMBs), and naphthalene. The methodology was investigatedwith a wide range of performance criteria such as repeatability, linearity, lower detection limits, collection efficiency, thermal conditioning, breakthrough volume and calibration methods using internal and external standards. standards. Stability of samples collected on adsorbent tubes during storage was also investigated. In addition, the sampling and analytical method developed during this study was applied to real samples duplicately collected in various indoor and outdoor environments. Precisions for the duplicate samples and distributed volume samples appeared to be well comparable with the performance criteria recommended by USEPA TO-17. The audit accuracy was estimated by inter-lab comparison of both duplicate samples and standard materials between the two independent labs. The overall precision and accuracy of the method were estimated to be within 30% for major aromatic VOCs such as BTEX. This study demonstrated that the adsorbent sampling and thermal desorption method can be reliably applied for the measurement of BTEX in ppb levels frequently occurred in common indoor and ambient environments.

• International Journal of Vascular Biomedical Engineering
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• v.3 no.1
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• pp.6-13
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• 2005

Individual clinical significance of each layer of CCA (common carotid artery) has not been well studied. We intended to measure the intima thickness (IT), media thickness (MT), and intima-media thickness (IMT) of CCA separately and tried to analyze the clinical significance. One hundred fifty one consecutive patients (mean age: $57{\pm}15$ years; 77 males, 74 females) underwent CCA scanning using high-resolution ultrasound. The images were off-line analyzed using B-mode ultrasound image processing, devised for individual measurement of IT and MT as well as IMT. The mean coefficients of variation of new method measuring IT, MT, and IMT separately were 0.16% for IMT and 0.21% for both IT and MT. The IT (p < 0.01), MT (p < 0.01) as well as IMT (p < 0.001) of patients with atherosclerotic disease were significantly thicker than that of the patients without atherosclerotic disease. Patients with hypertension showed significantly thicker IT (p < 0.01), MT (p < 0.001), and IMT (p < 0.001) than that of the patients without hypertension. However, only IT was thicker in patients with smoking (p<0.01) than that of the patients without smoking.

• The Journal of Information Systems
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• v.29 no.3
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• pp.1-34
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• 2020

Purpose Due to the complexity of policy environment in modern society, it is accepted as common basics of policy design to mix up a variety of policy instruments aiming the multiple functions. However, under the current situation of written-down policy specification, not only the public officers but also the policy researchers cannot easily grasp such frameworks as policy portfolio. The purpose of this study is to develop "Policy Attributes Taxonomy" identifying and classifying the public programs to help making decisions for allocative efficiency with effectiveness-based information. Design/methodology/approach To figure out the main scheme and classification criteria of Policy Attributes Taxonomy which represents characteristics of public policies, previous theories and researches on policy components were explored. In addition, to test taxonomic feasibility of certain information system, a set of "Feasibility Standards" was drawn from "requirements for well-organized criteria" of eminent taxonomy literatures. Finally, current government classification system in the area of social service was tested to visualize the application of Taxonomy and Standards. Findings Program Taxonomy Schemes were set including "policy goals", "policy targets", "policy tools", "logical relation" and "delivery system". Each program and project could be condensed into these attributes, making their design more easily distinguishable. Policy portfolio could be readily made out by extracting certain characteristics according to this scheme. Moreover, this taxonomy could be used for rearrangement of present "Program Budget System" or estimation of "Basic Income".

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1234-1239
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• 2003

In the product design process computer-aided engineering and optimization tools are widely utilized in order to reduce the total development time and cost. Since several simulation tools are involved in the process, information losses, omissions, or errors are common and the importance of seamless information exchange among the tools has been increased. In this study ISO STEP standards are adopted to represent the neutral format for CAE/CAO information exchange. The schema of AP209 is used to define the information of finite element analysis and the new schema is proposed to describe the information of structural optimization based on the STEP methodology. The schema is implemented by EXPRESS, information modeling language, and ST-Developer is employed to generate C++ classes and STEP Rose Library by using the schema denoted. To substantiate the proposed approach, the information access interfaces of the finite element modeling software (FEMAP), structural optimization software (GENESIS) and in-house topology optimization program are developed. Examples of the size optimization of a three-bar truss and topology optimization of a MBB beam are shown to validate the information exchange of finite element analysis and structural optimization using STEP standards.

• Journal of the Korean housing association
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• v.26 no.5
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• pp.61-70
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• 2015

According to "The regulations regarding the residential construction standards", residents' common spaces are restricted by the standards on building facilities. In a typical apartment complex, residents' communal facilities are represented by a children's playground, a elderly social station, and a management office. However, these residents' communal facilities do not reflect residents' composition characteristics. Multidisciplinary research and experimentation to enable the community of housing complex are being actively conducted. In these situation, we observed institutional improvement about installing standard of community space, and analysed the tendency. The purpose of this study is to propose practical institutions to review the institutional improvement. We conducted a case study where was renovated the community space according to the new standard. As a results, the installing standard of the community space has changed in the direction to increase the autonomy of resident. These results raise the practical performance of the community space, and it has the effect of increasing the satisfaction of the residential environment. The results of this study suggest an alternative to the institutional aspects and planning aspects for community activation in housing complex.

• Transactions on Electrical and Electronic Materials
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• v.15 no.3
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• pp.113-116
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• 2014

Power transformer insulation oil is critical to the useful life of the transformer. Although mineral base insulation oil is the most common type of transformer insulation oil in use, environmental and safety concerns has encouraged the development of biodegradable alternatives. Today, $Envirotemp^{(R)}\;FR3^{TM}$ is in commercial use and this study is aimed at ascertaining the possibility of applying the oil in Malaysia power transformers. A sample of $Envirotemp^{(R)}\;FR3^{TM}$ was tested to measure and compare the technical (including electrical, chemical and physical) properties of the oil according to Malaysian standards. The study found that the oil sample had better qualities, such as higher dielectric strength, lower dissipation factor, higher flash and fire points, higher moisture absorption capability, and less dissolved gases composition amongst others. However, it was also ascertained that further development in this area could be hindered due to Malaysia's lack of standards for biodegradable oil.