• Journal of Applied Reliability
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• v.5 no.2
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• pp.241-259
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• 2005

The environmental problem is a main subject of the 21C and an environment destruction phenomenon by various kinds of environmental materials is reaching serious level. Nations to be classified as the environmental developed country, are born again environmental rich country. And they earn a large income by trade Every kind environmental resource in an international commercial transaction. Especially, the study that a reliability assessment method to prevent to reliability problem to be happened when the solder lead(lead-free solder), non-cd component, non-bromide component(without the polybrominated biphenyls(PBB) and polybrominated diphenyl ethers(PBDE))and hexavalent chromium(Cr VI) clearance component and mercury-free applied to electronic equipment is progressed. As the result of the study for applying of a reliability assessment technique of lead-free solder that recognized the most of urgent problem at the company, combination accelerated life test could taken by adding and appling the part of a humidity acceleration part to Eyring Model which is proposed by R.E.Thomas. The reliability assessment methods study of PWB clean environmental materials is expected to respond to a reliability elevation and environmental material regulation policy spreading all over the world by beginning form Europe.

• ETRI Journal
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• v.26 no.2
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• pp.167-180
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• 2004

As component-based development (CBD) rapidly spread throughout the software industry, a comprehensive methodology is needed to apply it more systematically. For this purpose, a new CBD methodology named Magic & Robust Methodology Integrated III (MaRMI-III) has been developed. The purpose of this paper is to present MaRMI-III by its constituent processes and claim that it can be used to support system developers conduct CBD in a consistent manner. First, we review the CBD approach to system development and the role of CBD methodology, and then we explain the several characteristics of MaRMI-III which are considered necessary to the CBD environment. Next, we explain a process model of MaRMI-III which separates the development process from the project management process and prescribes well-ordered activities and tasks that the developer should conduct. Each phase forming the Process Model is explained in terms of its objectives and main constituent activities. Some techniques and workproducts related to each phase are also explained. Finally, to examine the usefulness of MaRMI-III, an analytical comparison with other CBD methodologies and the results of a questionnaire survey are described.

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.126-128
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• 2004

As e-mail is becoming increasingly important in every day life activity, mail users spend more and more time organizing and classifying the e-mails they receive into folder. Many existing recommendation systems or text classification are mostly focused on recommending the products for the commercial purposes or web documents. So this study aims to apply these application to e-mail more necessary to users. This paper suggests a dynamic recommendation agent system based on Rule Filtering Component recommending the relevant category to enable users directly to manage the optimum classification when a new e-mail is received as the effective method for E-Mail Management. Moreover we try to improve the accuracy as eliminating the limits of misclassification that can be key in classifying e-mails by category. While the existing Bayesian Learning Algorithm mostly uses the fixed threshold, we prove to improve the satisfaction of users as increasing the accuracy by changing the fixed threshold to the dynamic threshold. We designed main modules by rule filtering component for enhanced scalability and reusability of our system.

• Proceedings of the Korean Reliability Society Conference
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• 2005.06a
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• pp.393-404
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• 2005

The environmental problem is a main subject of the 21C and an environment destruction phenomenon by various kinds of environmental materials is reaching serious level. Nations to be classified as the environmental developed country, are born again environmental rich country. And they earn a large income by trade Every kind environmental resource in an international commercial transaction. Especially, the study that a reliability assessment method to prevent to reliability problem to be happened when the solder lead(lead-free solder), non-cd component, non-bromide component(without the polybrominated biphenyls(PBB) and polybrominated diphenyl ethers(PBDE))and hexavalent chromium(Cr VI) clearance component and mercury-free applied to electronic equipment is progressed. As the result of the study for applying of a reliability assessment technique of lead-free solder that recognized the most of urgent problem at the company, combination accelerated life test could taken by adding and appling the part of a humidity acceleration part to Eyring Model which is proposed by R.E.Thomas. The reliability assessment methods study of PWB clean environmental materials is expected to respond to a reliability elevation and environmental material regulation policy spreading all over the world by beginning form Europe.

• Proceedings of the Korean Society of Crop Science Conference
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• 2019.09a
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• pp.150-150
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• 2019

• Steel and Composite Structures
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• v.49 no.1
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• pp.81-89
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• 2023

A simplified calculation method of natural vibration characteristics of high-speed railway multi-span bridge-longitudinal ballastless track system is proposed. The rail, track slab, base slab, main beam, bearing, pier, cap and pile foundation are taken into account, and the multi-span longitudinal ballastless track-beam-bearing-pier-cap-pile foundation integrated model (MBTIM) is established. The energy equation of each component of the MBTIM based on Timoshenko beam theory is constructed. Using the improved Fourier series, and the Rayleigh-Ritz method and Hamilton principle are combined to obtain the extremum of the total energy function. The simplified calculation formula of the natural vibration frequency of the MBTIM under the influence of vertical and longitudinal vibration is derived and verified by numerical methods. The influence law of the natural vibration frequency of the MBTIM is analyzed considering and not considering the participation of each component of the MBTIM, the damage of the track interlayer component and the stiffness change of each layer component. The results show that the error between the calculation results of the formula and the numerical method in this paper is less than 3%, which verifies the correctness of the method in this paper. The high-order frequency of the MBTIM is significantly affected considering the track, bridge pier, pile soil and pile cap, while considering the influence of pile cap on the low-order and high-order frequency of the MBTIM is large. The influence of component damage such as void beneath slab, mortar debonding and fastener failure on each order frequency of the MBTIM is basically the same, and the influence of component damage less than 10m on the first fourteen order frequency of the MBTIM is small. The bending stiffness of track slab and rail has no obvious influence on the natural frequency of the MBTIM, and the bending stiffness of main beam has influence on the natural frequency of the MBTIM. The bending stiffness of pier and base slab only has obvious influence on the high-order frequency of the MBTIM. The natural vibration characteristics of the MBTIM play an important guiding role in the safety analysis of high-speed train running, the damage detection of track-bridge structure and the seismic design of railway bridge.

• Analytical Science and Technology
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• v.12 no.5
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• pp.436-440
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• 1999

Antistatic property and crystallization behavior of antistatic poly(ethylene terephthalate) (PET) were studied by feeding antistatic agents into polycondensation reactor. Glass transition and melting temperature of antistatic PET were decreased by poly(ethylene glycol) (PEG) component of antistatic agent. The crystallization rate of antistatic PET was inhibited by decreasing crystallization temperature. Thermal properties and crystallization behavior was affected POAG content of antistatic agent rather than sodium alkylsulfonate of it. The main antistatic component of antistatic agent was POAG. The main role of sodium alkylsulfonate was increasing melt viscosity of antistatic poly(ethylene terephalate) polymer.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.101-106
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• 2006

Balance shaft has a key role in reducing a engine vibration in a vehicle and widely applied for current models. Since balance shaft module consists many sub-component and each part has its own operational characteristics, some different analysis backgrounds should be integrated into one sub-part in balance shaft module and this is the main obstacles in making a design process. Moreover, the balancing shaft is rotating in high speed and such condition requires large safety factors in a design process owing to a lot of unexpected problems with the overwhelming rotation. Balance shaft is the core-component generating the intended unbalance as well as cancelling the unbalance force or moment by the engine module. So, the balance shaft should meet the high fatigue resistance not to mention of NVH performance. In this paper, a design strategy focused on balance shaft is developed to build a optimal model considering a engine vibration. Putting the unbalance mass distribution as main design parameter, some candidate model is verifed with structural and fatigue analysis and most appropriate model is proposed here.

• Natural Product Sciences
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• v.15 no.4
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• pp.229-233
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• 2009

The essential oil fraction was obtained from the leaves and flowers of Artemisia iwayomogi (Compositae) by steam distillation, and its main component, vulgarone B, was isolated by column chromatography. RAW 264.7 cells were used to investigate the anti-inflammatory properties of A. iwayomogi and vulgarone B. Cell viability was determined by MTT assay after treatment with various dilutions of the compounds. In addition, several assays were used to determine the effects of A. iwayomogi essential oil components on immune stimulation. Nitric oxide production in cells activated with lipopolysaccharide (LPS) was evaluated by reaction with Griess reagent. Both vulgarone B and the essential oil fraction of A. iwayomogi inhibited the production of nitric oxide. The effects on various cytokines released from the cells were also measured using ELISA. The production of prostaglandin $E_2$ was significantly decreased by treatment with A. iwayomogi oils. LPS-induced IL-$1{\beta}$ and IL-6 production were also decreased in a dose-dependent manner, but no significant effect on TNF-${\alpha}$ was observed at the concentrations tested. Finally, Western blot analysis revealed that A. iwayomogi oils reduced the levels of COX-2 and iNOS.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.393-398
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• 2007

Balance shaft has a key role in reducing a engine vibration in a vehicle and widely applied for current models. Since balance shaft module consists many sub-component and each part had its own operational characteristics, some different analysis background should be integrated into one sub-part in balance shaft module and this is the main obstacles in making a design process. Moreover, the balancing shaft rotating in high speed and such condition requires large safety factors in a design process owing to a lot of unexpected problems with the overwhelming rotation. Balance shaft is the core-component generating the intended unbalance as well as canceling the unbalance force or moment by the engine module. So, the balance shaft should meet the high fatigue resistance not to mention of NVH performance. In this paper, a design strategy focused on balance shaft is developed to build a optimal model considering a engine vibration. Putting the unbalance mass distribution as main design parameter, some candidate model is verified with structural and fatigue analysis most appropriate model is proposed here.