• 한국안전학회지
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• 제30권1호
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• pp.47-51
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• 2015

In the study, a new non-open cut tunnel steel pipe method using slot hole has been developed. As is overcomes shortcomings of conventional methods, it is applied to the field. The main concept of the new method is the steel pipe pumping system with slot holes which, by means of formation slot holes between each steel pipe, applied to the magnitude of the relaxed earth pressure caused by excavation to the ground to prevent ground displacement. The stability of the support members and effect of displacement control of the new method were verified through several ways as numerical analysis and site test. The new method was applied to the construction of a 11.5m wide, 7.4m high and 50m long section that passes side subway and large buildings in inner city. By applying the new method, tunnel construction was successfully completed in 6 months. It decreases the construction period to 30% compared to that of conventional methods, and ground was almost negligible.

• 한국지반공학회논문집
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• 제20권6호
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• pp.51-59
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• 2004

공학적 물성치로서의 저변형율에서의 전단탄성계수의 결정은 다양한 토목분야에서 매우 중요하다. 본 논문에서는 저변형율에서의 전단탄성계수를 결정하기 위하여 개발된 HWAW(Harmonic Wavelet Analysis of Wave)방법을 이용한 지반조사기법의 실제 현장에서의 타당성을 검증하기 위하여 두 곳의 현장에 HWAW방법을 적용하였다. HWAW방법을 검증하기 위하여 동일한 현장에서 수행된 SASW시험과 PS-Suspension Logging 실험의 결과와 비교하였다. 이를 통하여 HWAW방법이 배경잡음과 지반의 횡방향 불균일성에 의한 오류를 기존 방법에 비하여 최소화 할 수 있으며, 국부적이며 정밀한 대상지반의 실제 전단파 속도 주상도를 매우 효과적으로 결정할 수 있음을 확인할 수 있었다.

• 자동차안전학회지
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• 제8권4호
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• pp.12-17
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• 2016

NHTSA (National Highway Traffic Safety Administration) has offered consumers the vehicle safety information on their car since 1978. NHTSA believes that they contribute auto makers to develop safer vehicle for customers, which will result in even lower numbers of deaths and injuries resulting from motor vehicle crashes. NHTSA has been studied why people are still dying in frontal test despite of the use of many restraints system and they understand that current test does not reflect real world crash data such as oblique and corner impact test. As a result, NHTSA announced that a new test method will be introduced to use of enhanced biofidelic dummy and new crash avoidance technology evaluation from 2019. New and refined injury criteria will be applied to Head / Neck / Chest / Lower Leg. BrIC(Brain Injury Criterion)value in NHTSA test results using THOR dummy from 2014 to 2015 was average 0.91 and 1.24 in driver and passenger dummies. IIHS 64kph SOF test is the most likely to new frontal oblique test in an aspect of offset impact which is being studied by NHTSA. In this paper, we focused on head injury, especially brain injury - BrIC and conducted IIHS 64kph SOF (Small Offset Front) test with Hybrid III dummy to evaluate the injury for BrIC. Based on the test results, these data can be predicted BrIC level and US NCAP rating with current vehicle.

• 한국음향학회지
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• 제6권3호
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• pp.17-22
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• 1987

새로운 차음성능 측정방법인 표면인텐시티법을 이용하여 실제 건축물의 현장에서 각부위별 차음성능 평가하고. 이를 종래의 음압측정방법과 은향인텐시티법 및 이론계산에 의한 결과 치 와 비교 . 검토하였다. 표면인텐시티법에 의한 건물부위의 차음성능 측정결과치는 음향인 텐시티법 및 이론계산에 의한 결과치와 잘 일치하였으며, 표면 인텐시티법은 음향인텐시티 법과 더불어 종래의 음압측정방법에 비해 측정시 주위 암소음 및 flanking transmission의 영향을 적게 받는 것으로 나타났다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 가을 학술발표회 논문집
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• pp.381-388
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• 1999

The existing methods for installation of long steel pipe pile have some uneconomical problems such as increase of installation cost and period due to the welding of two piles and removal of soil plug, and decrease of driving efficiency due to the increase of driving resistance by time effect during the welding of piles and removal of soil plug, etc. Thus, in this study, new installation method for long steel pipe pile is suggested to work out the existing problems, and calibration chamber tests are peformed to investigate both driving and economical efficiency for the suggested method. The test results showed that the new installation method has increase bearing capacity as well as reduce installation cost and period for long steel pipe piles as compared with existing methods.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 A
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• pp.466-468
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• 2002

In order to newly define and specify the performance and the testing method of the high-voltage circuit breaker, IEC 62271-100 was published in May, 2001 and took place of IEC 60056 which had been used since 1987. This new standard intensifies the requirement and the test method of the circuit breaker and also domestic manufacturer makes progress the new product development. And, KERI also goes on the build-up project of short-circuit testing facilities for fulfilling the testing method requirements in new IEC 62271-100. This paper introduce the limiting method of short-circuit making current by controlling the time constant of dc component.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2002년도 종합학술발표회 논문집 Vol.12 No.1
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• pp.423-433
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• 2002

A very fast method of moments(MoM) for the analysis of microstrip structure is considered based upon the use of rooftop basis and razor test functions in conjunction with a new closed-form Green's functions. The present method presents a robust approach to obtain the Green's functions which can be derived by use of only one set of approximation parameters independently of operating frequency range. Moreover, using the present MoM scheme, the MoM matrix elements can be analytically evaluated with few number of terms in comparison with the previous method. So, the computational efficiency can be improved significantly without loss of the precision. In order to check the validity of the present method, performance is demonstrated for the example of a coaxially-fed microstrip transmission line and the present results are compared with the previous results.

• Communications for Statistical Applications and Methods
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• 제29권1호
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• pp.1-25
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• 2022

A modified Bagdonavičius-Nikulin chi-square goodness-of-fit is defined and studied. The lymphoma data is analyzed using the modified goodness-of-fit test statistic. Different non-Bayesian estimation methods under complete samples schemes are considered, discussed and compared such as the maximum likelihood least square estimation method, the Cramer-von Mises estimation method, the weighted least square estimation method, the left tail-Anderson Darling estimation method and the right tail Anderson Darling estimation method. Numerical simulation studies are performed for comparing these estimation methods. The potentiality of the new model is illustrated using three real data sets and compared with many other well-known generalizations.

• 한국지반공학회논문집
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• 제25권8호
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• pp.57-64
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• 2009

본 연구에서는 등가변형을 이용하며 테이퍼 말뚝의 지지력을 산정하는 방법을 제안하였다. 지반조건과 테이퍼각도를 고려하여 지지력을 산정하던 기존의 방법과 달리, 테이퍼말뚝의 지지력산정시 콘관입시험 결과를 활용하도록 하였다. 이때 테이퍼말뚝은 등가변형을 이용하여 형태를 단순화 시켰으며 이를 통해 실무에서 비교적 쉽게 지지력을 산정 할 수 있는 방법을 제안하였다. 제안된 방법의 검증을 위해 실내시험과 현장시험을 실시하였다. 실내모형시험 결과로부터 측정된 극한지지력과 본 연구에서 제안된 방법에 의한 예측값을 비교한 결과 표준편차는 $0.05{\sim}0.121$, COV는 $0.04{\sim}0.05$의 값을 보여 대체적으로 유사한 결과를 보였으며, 현장시험은 약 2.5%의 오차를 보여 측정값에 근접함을 알 수 있었다. 그 결과 제안된 지지력 산정법은 테이퍼말뚝의 지지력을 비교적 정확하게 예측하는 것으로 나타났다.

• Journal of Electrical Engineering and Technology
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• 제12권5호
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• pp.1883-1890
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• 2017

Transformers are one of the most precious elements of the electric power system. Stability and reliability of the electric power network mainly depend on the working of the transformer. Leakage reactance of the transformer is one of the important factors and accurate calculation of the leakage reactance is necessary for the transformer designers and electric distributors. Leakage reactance of the transformer depends on the geometry of the transformer. There are many different methods for the calculations of the leakage reactance however mostly are usable when the axial heights of the high voltage and low voltage windings are equal. When the axial heights of high voltage and low voltage windings are asymmetric most of the analytical methods are not reliable. In this study, a new analytical method is introduced for the calculation of the leakage reactance. Fourteen different transformers are investigated in this study and four of them are presented in this paper. The results of the new analytical method are compared with the experimental results. Other analytical and numerical methods are also compared with this new method. Results show that this method is more reliable and accurate as compared to the other analytical methods. The maximum relative error between short-circuit test and proposed method for these fourteen transformers was less than 2.8%.