• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.1
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• pp.7-12
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• 2012

Chemical mechanical polishing(CMP) technology is faced with the challenge of processing new electronic materials. This paper focuses on the balance between chemical and mechanical reactions in the CMP process that is required to cope with a variety of electronic materials. The material properties were classified into the following categories: easy to abrade(ETA), difficult to abrade(DTA), easy to react(ETR) and difficult to react(DTR). The chemical and mechanical balance for the representative ETA-ETR, DTA-ETR, ETA-DTR and DTA-DTR materials was considered for defect-free surfaces. This paper suggests the suitable polishing methods and examples for each electronic material.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.12a
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• pp.311-316
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• 2003

정보통신기술의 발달로 대부분 사회의 기반구조가 사이버 사회로 전환되었고 다양한 형태의 경제사회 활동을 수행키 위해 정보보호제품의 활용이 극대화되었으며 더욱 중요시되었다. 이러한 사회흐름에 기반하여 정보보호제품의 안전한 선택 및 사용을 위한 기본적 선택기준은 검증받은 암호화 모듈을 바탕으로 하는 정보보호제품에 대한 신뢰 기관의 안전성 평가 결과일 것이다. 암호화 모듈에 대한 안전성 평가로 가장 널리 참조되는 것은 미국의 NIST(National Institute of Standards and Technology)가 수행하는 CMVP(Cryptographic Module Validation Program)이며, 세계적으로 인정받고 있다. 본 논문에서는 암호 모듈의 평가체계에 대해 설명하였으며 그 기준인 FIPS 140-2 DTR을 분석하여 향후 개발 가능한 CMVP의 안전성 평가 툴 기준에 대해 제시하였다.

• Journal of Information Processing Systems
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• v.13 no.5
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• pp.1358-1371
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• 2017

Dynamic thermal rating (DTR) system is an effective method to improve the capacity of existing overhead line. According to the methodology based on CIGRE (International Council on Large Electric systems) standard, ampacity values under steady-state heating balance can be calculated from ambient environmental conditions. In this study, simulation analysis of relations between parameters and ampacity is described as functional dependence, which can provide an effective basis for the design and research of overhead transmission lines. The simulation of ampacity variation in different rating scales is described in this paper, which are determined from real-time meteorological data and conductor state parameters. To test the performance of DTR in different rating scales, capacity improvement and risk level are presented. And the experimental results show that the capacity of transmission line by using DTR has significant improvement, with low probability of risk. The information of this study has an important reference value to the operation management of power grid.

• Elastomers and Composites
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• v.51 no.4
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• pp.317-341
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• 2016

Polyamide (PA) is one of five engineering plastic materials which has good mechanical properties and competitive price compared to other engineering plastics and it has various applications including in the areas of automotives, electronics and aerospace industry. Even though PA market grows fast compared to other engineering plastics, it has few organized literatures regarding researches and applications. In this paper, we review overall background, characteristics, formulation, current market trends and technology development of PA resins and their composites.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.2
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• pp.139-150
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• 2014

This paper suggests an algorithm to improve QoS by using DTR bit employed in the MIL-STD-188-220 protocol, when there is a multi-path between source and destination in the environment of KVMF tactical network supporting NCW. The MIL-STD-188-220 protocol can evaluate the link quality relatively but it cannot support optimal path selection for QoS. In order to solve this problem, we design an algorithm for selecting path using topology table which reflects measured DTR of path after the completion of transmission. The performance of the proposed algorithm has been evaluated by OPNET simulator. As a result of the simulation, it is found that QoS of proposed algorithm is enhanced higher than that of the MIL-STD-188-220 in the aggravated communication environment.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.12
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• pp.1401-1411
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• 2010

In this paper, we suggested the tolerance limits of FAR(Fully Anechoic Room) using correlation factor between OATS(Open area Test Site) to measure EMI(Electromagnetic Interference) and FAR to measure EMS(Electromagnetic Susceptibility). FAR Project(SMT4-CT96-2133), CISPR/A/665/DTR, and CISPR A/665/DTR documents are analyzed and theoretical correlation factor based on the documents and theoretical equations is drawn. To obtain the experimental correlation factor, EUT(Equipment Under Test) is fabricated as well as measured at the 10 m distance OATS and in the 3 m distance FAR. Also, to suggest the tolerance limits of EUT with multi sources, radiation theory for electric and magnetic dipoles is programmed. We drew the correlation factor for EUT with multi sources through the programs. As the tolerance limits of FAR is newly defined, It can be used alternative test site for OATS to measure EMI, efficiently.

• Journal of Veterinary Science
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• v.21 no.5
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• pp.75.1-75.8
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• 2020

Background: Dental diseases are common in dogs and cats, and accurate measurements of dentoalveolar structure are important for planning of treatment. The information that the comparison computed tomography (CT) with dental radiography (DTR) is not yet reported in veterinary medicine. Objectives: The purpose of this study was to compare the DTR with CT of dentoalveolar structures in healthy dogs and cats, and to evaluate the CT images of 2 different slice thicknesses (0.5 and 1.0 mm). Methods: We included 6 dogs (2 Maltese and 1 Spitz, Beagle, Pomeranian, mixed, 1 to 8 years, 4 castrated males, and 2 spayed female) and 6 cats (6 domestic short hair, 8 months to 3 years, 4 castrated male, and 2 spayed female) in this study. We measured the pulp cavity to tooth width ratio (P/T ratio) and periodontal space of maxillary and mandibular canine teeth, maxillary fourth premolar, mandibular first molar, maxillary third premolar and mandibular fourth premolar. Results: P/T ratio and periodontal space in the overall dentition of both dogs and cats were smaller in DTR compared to CT. In addition, CT images at 1.0 mm slice thickness was generally measured to be greater than the images at 0.5 mm slice thickness. Conclusions: The results indicate that CT with thin slice thickness provides more accurate information on the dentoalveolar structures. Additional DTR, therefore, may not be required for evaluating dental structure in small-sized dogs and cats.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1439_1440
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• 2009

본 논문에서는 최근 국내에서 개발된 자기재 및 플라스틱 핀 애자의 단점을 보완한 실리콘 고무 재질의 하우징으로 구성된 폴리머 핀 애자(Polymer Pin Insulator) ANSI Class 55-3에 대하여 ANSI Std. C29.5(1984)에서 요구되는 전기적 및 기계적 특성을 고찰하였다. 정격전압이 11.5kV인 폴리머 핀 애자의 건조 및 주수 상용주파섬락전압시험, 뇌충격섬락전압시험, 전파장해전압시험 등의 전기적 특성과 굽힘시험 등의 기계적 특성을 고찰하였으며, 그 결과 ANSI Std. C29.5(1984)의 요구사양에 만족한 실선로에 적용할 수 있는 특성을 나타내었다.

• Elastomers and Composites
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• v.52 no.1
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• pp.1-8
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• 2017

Hydrolysis resistance and mechanical property changes of polyketone (POK)/glass fiber (GF) composites were investigated for GF concentrations varying between 30 and 50%. The hydrolysis resistance of GF filled POK and polyamide66 (PA66, hydrolysis resistant grade) composites were compared. As shown by the experimental results, increasing the immersion time of the composites in a monoethylene glycol (MEG)/water solution at $120^{\circ}C$ had no impact or resulted in slightly decreased mechanical properties such as the tensile strength, tensile modulus, and strain at break in case of POK composites, whereas the mechanical properties of PA66 composites showed a significant drop. Increasing GF concentrations increased the tensile strength, tensile modulus, flexural strength, and flexural modulus of POK composites; however, impact strength did not show significant changes. Hydrolysis mechanisms of POK and PA66 are discussed.

• Elastomers and Composites
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• v.52 no.1
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• pp.59-68
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• 2017

The effect on the hydrolysis resistance properties by the addition of maleic anhydride grafted EMDM (MA-g-EPDM) and PP (MA-g-PP) to a PA66/GF composite was investigated with respect to the mechanical properties, thermal properties, and morphology. The degree of hydrolysis of the PA66/GF composite was measured using py-GC/MS analysis. When compared to the PA66/GFcomposite in MEG/water solution, the composites where MA-g-EPDM and MA-g-PP were added to PA66/GF showed a higher degree of hydrolysis resistance, impact strength, and thermal properties, whereas their tensile strength, tensile modulus, flexural strength and flexural modulus decreased. As immersion time in the solution increases, the rate of tensile strength drop of the MA-g-PP added composite appeared lower than that of the PA66/MA-g-EPDM/GF and PA66/GF composites. The py-GC/MS analysis confirmed the formation of PA66 hydrolysis reaction by products such as carboxylic acid and alkylamine with increasing immersion time.