• 한국안전학회지
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• 제16권4호
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• pp.39-46
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• 2001

It is noted that KS D 3507 pipe steel has several problems when it is used as a city gas pipe at medium pressure. So new pipe steel, KS D 3631, was developed in order to be used as a pipe for medium and low pressure and now it is being substituted for D 3507. In this study, several mechanical tests, such as tensile test, microhardness test, and Charpy impact test were conducted to get material properties of D 3507 and D 3631 pipe steels. And also microstructures at the weld and heat affected zones were observed for the two materials. From the Charpy test results $K_{IC}/$ was estimated for the upper and lower shelf and the critical crack length is calculated for supposed axial semi-elliptical surface cracks. And the burst pressure is estimated as a function of wear depth for a defective D 3631 pipe by using the finite element method. The burst pressure is also calculated for pipes with an axial crack by using the published equations.

• ETRI Journal
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• 제35권1호
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• pp.109-119
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• 2013

Static testing of analog-to-digital (A/D) and digital-to-analog (D/A) converters becomes more difficult when they are embedded in a system on chip. Built-in self-test (BIST) reduces the need for external support for testing. This paper proposes a new static BIST structure for testing both A/D and D/A converters. By sharing test circuitry, the proposed BIST reduces the hardware overhead. Furthermore, test time can also be reduced using the simultaneous test strategy of the proposed BIST. The proposed method can be applied in various A/D and D/A converter resolutions and analog signal swing ranges. Simulation results are presented to validate the proposed method by showing how linearity errors are detected in different situations.

• 반도체디스플레이기술학회지
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• 제3권4호
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• pp.19-27
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• 2004

The characteristic evaluation of A/D converter is to measure the linearity of the converter. The evaluation of the linearity is to measure the DNL, INL, gain error and offset error in the various test parameters of A/D converter. Generally, DNL and INL are to be measured by the Histogram Test Algorithm in the DSP-based ATE environment. And gain error and offset error are to be measured by the calculation equation of the measuring algorithm. It is to propose the new Concurrent Histogram Test Algorithm for the test of the housekeeping A/D converter used in the CDMA cellular phone. Using the proposed method, it is to measure the DNL, INL, gain error and offset error concurrently and to show the measured results.

• Elastomers and Composites
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• 제53권4호
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• pp.220-225
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• 2018

Resilient pads play a major role in reducing the impact of loads on a rail in a rail-fastening system, which is essentially used for a concrete track. Although a compression set test is commonly used to measure the durability of a resilient pad, the static spring constant is often observed to be different from the fatigue test. In this study, a modified compression set test method was proposed to monitor the variations in the compression set and static spring constant of a resilient pad with respect to temperature and time. In addition, the life of the resilient pad was predicted by performing an acceleration test based on the Arrhenius equation.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2008년도 추계학술대회 논문집
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• pp.62-65
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• 2008

In this paper, we estimated the D147 mode test, which is introduced as a new emission test mode for the driving car using diesel fuel. And we compared the D147 test mode, Lug-Down3 test mode and no load acceleration test mode. And the exhaust gas concentration between the three modes was compared. The exhaust concentration at the D147 mode is lower than the exhause concentration at the Lug-Down 3 mode and higher than that at the no load acceleration test mode. Also the correlation factor was estimated between the D147 mode and Lug-Down 3 mode.

• 한국국방경영분석학회지
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• 제34권1호
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• pp.79-98
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• 2008

R&D 투자와 경제성장간의 관계에 대한 많은 기존 논의들은 R&D 투자가 경제성장에 대해 강한 양(+)의 관계가 존재함을 제시하고 있다. 그러나 투자와 성장사이의 강한 결합관계가 반드시 일방적 인과관계를 의미하는 것은 아니기 때문에 인과관계의 방향에 대한 보다 심층적인 연구가 필요하다. 특히 급변하는 안보환경 속에서 국방 R&D 투자가 증대되고 있음을 고려해 볼 때 국방 R&D 투자와 타 부문 R&D 투자 및 경제성장과의 결합관계에 대한 논의에 앞서 각 변수들 간의 인과관계에 대한 연구가 선행되어야 하나, 현재까지 국방 R&D 투자와 타 부문 간의 인과관계를 연구한 실적이 전무한 실정이다. 따라서 국방 R&D 투자와 다른 변수들과의 인과관계 분석을 통하여 국방 R&D 투자정책에 관한 정책적 시사점을 제시하였다는데 본 논문의 의미를 두고자 한다.

• 전자공학회논문지
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• 제50권1호
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• pp.131-136
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• 2013

칩 적층기술의 발달로 TSV(Through Silicon Via) 기반 3D IC가 개발되었다. 3D IC의 높은 신뢰성과 수율을 얻기 위해서는 pre-bond 와 post-bond 수준에서 다양한 TSV 테스트가 필수적이다. 본 논문에서는 pre-bond 다이의 TSV 연결부에서 발생하는 미세한 고장과 post-bond 적층된 3D IC의 TSV 연결선에서 발생하는 다양한 고장을 테스트할 수 있는 설계기술을 소개한다. IEEE 1500 표준 기반의 래퍼셀을 보완하여 TSV 기반 3D IC pre-bond 및 post-bond의 at speed test를 통하여 known-good-die와 무결점의 3D IC를 제작하고자 한다.

• 디지털융복합연구
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• 제17권10호
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• pp.273-282
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• 2019

본 연구는 D유형 성격에 따른 간호대학생의 자아존중감, 대인관계, 행복 및 대학생활적응을 분석하고 비교하기 위해 시도되었다. 대상은 간호대학생 181명(D유형 성격 대상자 53명, D유형 성격이 아닌 대상자 128명)이었다. 자료수집은 구조화된 질문지를 이용하여 자가보고하도록 하였다. 자료분석은 ${\chi}^2$-test, Fisher exact test 및 independent t-test를 사용하였다. 분석결과, D유형 성격에 따라 자아존중감, 대인관계, 행복, 대학생활적응에서 통계적으로 유의한 차이가 나타났다. D유형 성격 대상자에서 자아존중감은 간호학과 적응 정도, 대인관계는 종교, 행복은 경제상태, 대학생활적응은 종교와 간호학과 적응 정도에서 유의한 차이를 나타냈다. D유형 성격이 간호대학생의 자아존중감, 대인관계, 행복 및 대학생활적응을 낮추는 요인임을 보여주었다. D유형 성격 간호대학생에서 자아존중감, 대인관계, 행복 및 대학생활적응을 높이기 위한 전략이 필요하다.

• 한국의류산업학회지
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• 제20권3호
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• pp.353-359
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• 2018

In this study, fused deposition modellig(FDM) 3D printing technology has been applied directly to polyester voil fabric to produce 3D printed lace/voil composite fabrics. A stereolithograpy(STL) file with a lace type 3D modelling under the various thickness were prepared and transformed into a g-code file using a g-code generator. The extrusion conditions for FDM 3D printing were controlled by 50mm/s of nozzle speed, $235^{\circ}C$ of nozzle temperature, $40^{\circ}C$ of heating bed temperature. 3D printed lace/voil composite fabriscs manufactured by 3D printing based on FDM using a thermoplactic polyurethane(TPU) filaments were obtained. To evaluate the mechanical properties and washability of the fabricated 3D printed lace/voil composite fabric, KES-FB system test, washing fastness test and dry cleaning resistance test were conducted. As 3D printing thickness increased, KOSHI, NUMERI, and FUKURAMI of 3D printed lace/voil composite fabric increased. From the results of the primary hand value test, 3D printed lace/voil composite fabrics were confirmed to be applicable to women's summer garments. As a result of the washability and dry cleaning resistance test of the 3D printed lace/voil composite fabrics, all samples were graded 4-5.

• 한국신뢰성학회지:신뢰성응용연구
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• 제9권3호
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• pp.233-248
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• 2009

PAM(Power Amplifier Module) is the important part of a mobile phone transmitter. It amplifies the strength of signal transmitting from a mobile phone to base stations enough to resist noise or interference. In this paper reliability assessment criteria for the PAM are established in terms of quality certification test and lifetime test. The former quality certification test comprises general performance test and environmental test. Items which pass the test undergo lifetime test which guarantees the extent of mean lifetime with certain confidence.