• 통상정보연구
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• 제12권1호
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• pp.153-175
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• 2010

This study conducts an analysis to verify an existence of co-movement among the exchange rates of Yuan-Dollar, Yen-Dollar and Won-Dollar by using time series data. An analysis period is divided into two periods. Therefore the first analysis period is from Dec. 17, 1997 to Jul. 21th. 20, 2005 and the second analysis period is from Jul. 25th, 2005 to Nov. 20th. 2009. This paper uses VAR model and daily data of exchange rates during the period. According to the result of an empirical analysis, yuan-dollar exchange rate has affected by th other variables ; yen-dollar exchange rate. It can be proved by result of an impulse response test and variance decomposition test in the second period. Therefore the won-dollar, yen-dollar, and Yen-dollar exchange rate has been influenced each other and the relationship will be maintained.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2006년도 제27회 추계학술대회논문집
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• pp.127-131
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• 2006

본 논문에서는 역해석의 한 형태인 시험데이터 보정기법을 제시하였다. 이 방법을 적용하여 계측이 용이한 온도/압력 데이터로부터 상대적으로 계측이 어려운 유량, 열 전달율 등의 데이터를 도출할 수 있었다. 본 논문에서는 시험데이터 보정기법을 활용하여 발사체 가압시스템으로 널리 활용되는 극저온/고압 헬륨 토출시스템의 예비시험을 통하여 획득된 온도/압력 데이터로부터 유량, 열 전달율을 도출하는 방법 및 결과를 제시한다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1999년도 제30회 추계학술대회
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• pp.19-24
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• 1999

Understanding of wear mode and prediction of wear rate of parts in sliding contact are very important in field of meterial design relating with wear resistant. This paper has been undertaken to analyze the possibility of elucidation of wear mode and prediction of wear rate for annealed steel in sliding contact using the X-ray diffraction. The sliding wear test with various velocities using pin-on-disc machine and the X-ray diffraction test on the worn surface have been carried out. The results have been shown that the magnitude of residual stress and half-value breadth on the worn surface have a good correlation with wear mode. The difference between before and after test of half-value breadth on worn surface has been shown to be exponential relation with wear rate in the same wear mode.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.935-940
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• 2005

We generally get the Heat Release Rate by two other method. One is the calculation method from the Oxygen consumption rate and another is the calibration curve method of Temperature rising rate. In this study we compare the results of both test methods with five same specimens. From the test result we get the difference of reproducibility and checked some reasons of the difference. This paper includes some points to be careful for more creditable results for each test method.

• Pediatric Infection and Vaccine
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• 제4권2호
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• pp.240-256
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• 1997

목 적 : 초등학생의 성별, 연령별, 예방 접종률, 접종 완성률, 접종 시기를 비교하고, 간염 표지자 양성률을 검토하여 경기도 지역에서 과거 15년 동안 영아, 유아 및 초등학생을 대상으로 병의원, 보건소 및 학교 등에서 실시한 B형 간염 예방 접종 실태를 파악하고자 하였다. 방 법 : 1993년에 경기도 지역 초등학교 학생들을 집락 추출(cluster sampling)하여 실시하였다. 학교마다 각 학년별로 한 학급을 선정하여 총 2,072 명을 대상으로 혈청학적 검사와 설문 조사를 실시하였다. 결 과 : 1) 성별 HBsAg 양성률은 남자 3.7%, 여자 2.7%였고, 평균 3.4%였다. 연령별 HBsAg 양성률은 7세 3.5%, 12세 5.2%로 연령이 증가함에 따라 높아지는 경향을 보였다. 2) 어머니들의 B형 간염 출산 전 수검율은 10.2%, 출산 후 수검율은 42.5% 였다. 부모의 학력이 높을수록, 아버지의 직업이 사무직인 경우에 출산 전, 출산 후 수검율이 높았다. 3) 전체 예방 접종률은 82.6%, 접종 완성률은 69.8%, 추가 접종률은 42.8%였다. 연령이 증가함에 따라 예방 접종률, 접종 완성률, 추가 접종률이 모두 감소하였다. 부모의 학력이 높을 수록 예방 접종률, 접종 완성률, 추가 접종률이 증가하였다. 연령이 어릴수록 1 세 미만에 접종한 비율이 증가하였고, 7세 이상에 접종한 비율은 감소하였다. 부모의 학력이 높을수록, 아버지의 직업이 사무직인 경우에 1세 미만에 접종한 비율이 높았다. 4) 예방 접종 시기에 따른 간염 표지자 양성률에서 HBsAg과 Anti-HBc 양성률은 1~6세, 7세 이후, 1 세 미만의 순서로 높았다. 접종회수가 증가함에 따라 Anti-HBs 양성률은 유의하게 증가하였다. 기본 3회 접종 후 5년째 된 군에서 Anti-HBs 양성률은 85.7%, 유효 역가율은 69.6% 로 가장 낮았다. 결 론 : 이상의 결과를 통하여 전체 접종률은 82.6%, 접종 완성률은 69.8% 로 아직 낮은 수준으로 나타났다. 특히 부모의 학력이 낮고 아버지 직업의 사회적 지위가 낮은 계층은 출산 전 출산 후 산모의 HBV 수검율, 자녀의 백신 접종률, 접종 완성률이 모두 낮은 것으로 보아 의료 기관의 접근도가 떨어지고 예방 접종의 중요성에 대한 인식도 낮은 것으로 생각된다. 앞으로 B 형 간염 예방 접종 사업은 지속적인 보건 교육과 함께 이러한 사회적 지위가 낮은 계층 자녀의 접종률을 높이는 특별 관리 대책이 필요하리라 생각된다.

• 소성∙가공
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• 제16권2호
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• pp.101-106
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• 2007

Uniaxial displacement controlled tests were performed on annealed Type 304 stainless steel at room temperature. A servo-controlled testing machine and strain measurement on the gage length were employed to measure the response to a given input. The test results exhibit that the flow stress increases nonlinearly with the strain rate and the relaxed stress at the end of the relaxation periods depends strongly on the strain rate preceding the relaxation test. The rate-dependent inelastic deformation behavior is simulated using a new unified viscoplasticity model that has the rate-dependent format of nonlinear kinematic hardening rule, which plays a key role in modeling the rate dependence of relaxation behavior. The model does not employ yield or loading/unloading criteria and consists of a flow law and the evolution laws of two tensor and one scalar-valued state variables.

• 대한기계학회논문집
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• 제17권10호
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• pp.2391-2397
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• 1993

The distribution of fatigue crack growth rate is influenced by the measuring interval and methods of calculation of crack growth rate. The purpose of this paper is to suggest a method for the evaluation of crack growth rate distribution without the influence. The constant ${\Delta}P$ test and the constant .DELTA.K test are executed by using the CT specimen. The measuring interval of (${\Delta}a$/W=0.0067~0.014) crack length is not affected by methods of the calculation of the fatigue crack growth rate is suggested.

• Journal of Advanced Marine Engineering and Technology
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• 제20권5호
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• pp.68-75
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• 1996

The vacuum drying characteristics of water-saturated porous media were studied experimentally. The water-saturated porous media, water-saturated sand layer, was heated by the isothermal bottom wall of the rectangular vessel. The vacuum drying rate and temperature distribution of the sand layer were measured and calculated under a variety of conditions of heated wall temperature, vacuum rate, and thickness of the test material. It was found that the drying rate due to the heat and mass teansfer is greatly influenced by the heated wall temperature, vacuum rate, and thickness of the test material.

• 동력기계공학회지
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• 제11권4호
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• pp.98-102
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• 2007

In this study, a measurement method of leakage flow-rate for pneumatic driving apparatus is proposed. The existing measurement methods of leakage flow-rate of air need disassemble the test component. Therefore, there is no effective method to measure the leakage flow-rate while operating pneumatic driving apparatus. In this study, the leakage flow-rate is measured from the pressure change in an isothermal chamber that can realize isothermal conditions by stuffing the steel wool into it. Therefore, a wide range of flow-rate could be measured only from the pressure response and the leakage flow-rate can be measured during operating pneumatic driving apparatus. The effectiveness of the proposed method is proved by experimental results.

• Advanced Composite Materials
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• 제16권2호
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• pp.167-180
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• 2007

The tensile strength of unidirectional carbon fiber reinforced plastics under a high strain rate was experimentally investigated. A high-strain-rate test was performed using the tension-type split Hopkinson bar technique. In order to obtain the tensile stress-strain relations, a special fixture was used for the impact tensile specimen. The experimental results demonstrated that the tensile modulus and strength in the longitudinal direction are independent of the strain rate. In contrast, the tensile properties in the transverse direction and the shear properties increase with the strain rate. Moreover, it was observed that the strain-rate dependence of the shear strength is much stronger than that of the transverse strength. The tensile strength of off-axis specimens was measured using an oblique tab, and the experimental results were compared with the tensile strength predicted based on the Tsai-Hill failure criterion. It was concluded that the tensile strength can be characterized quite well using the above failure criterion under dynamic loading conditions.