• Journal of Biosystems Engineering
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• v.15 no.3
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• pp.199-206
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• 1990

연구 I에서 수행한 소뇌모델 선형조합 신경망(CMLAN)의 분석 결과와 제안된 능률적 학습 알고리즘들에 의거하여 이차원 비선형 함수치의 출력 모의시험과 팔의 형태에 따라 두개의 목적치를 갖는 2 자유도 머니퓨레이터의 동작지령 산출 모의시험을 행하였다. 특히 2 자유도 머니퓨레이터의 경우, 작업공간에 적절한 입력네트의 변수를 선정하고 하나의 입력공간을 공유하는 두개의 세부 소뇌모델 선형조합 신경망을 서로 연결하는 구조로써 팔의 형태와 목적 지점에 따라 네트를 선정하는 구조를 갖도록 하였다. 제안한 학습 알고리즘의 성능 및 CMLAN의 학습에 따른 효과를 학습이득에 따라 컴퓨터로 모의시험하였으며 그 결과를 분석하였다. 잘 알려진 신경망인 BACK-PROPAGATION 다층(Multi-Layer) 신경망과 함수연결 신경망(Functional Link Net)을 이용한 모의시험 결과를 비교 분석하였다. CMLAN의 학습 능률성은 학습에 소요되는 컴퓨터의 cpu시간과 학습 중의시스템의 최대 편차와 RMS 편차의 변이도 및 최종 시스템 수렴치로서 나타내었다.

• Journal of the Korean Geotechnical Society
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• v.17 no.5
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• pp.137-145
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• 2001

지오텍스타일 튜브공법은 준설토, 준설모래, 오염토사 등을 수리학적 채움을 통하여 해양구조물이나 수리학적 구조물을 축조하는 공법이다. 본 연구에서는 지오튜브공법의 국내적용을 위하여, 미국공병단의 최소 요구사항을 바탕으로 지오텍스타일을 선정하여 다양한 실내시험과 현장 적용성 시험을 실시하였다. 실내시험은 지오텍스타일과 토사간의 접촉마찰특성 분석을 위하여 대형직접전단시험을 실시하였으며, 해양구조물 설치시 파도와 조수의 영향으로 인한 토사유출량 분석을 위한 유실율시험을 실시하였다. 또한, 오염토사를 채움토사로 적용할 경우에 장.단기 환경적 영향에 대한 환경시험을 실시하였다. 현장시험은 실내모형시험을 바탕으로 토사와 물의 슬러리 혼합비율에 따른 지오텍스타일 튜브 채움방법 및 유효높이 및 단위중량 등의 계측을 실시하였다. 각종 실내 및 현장시험결과, 채움토사입자의 유실율은 약 5.0~6.0%를 유지하였으며, 지오텍스타일의 투수계수는 $\alpha$$\times$$10^{-4}$cm/sec 이상이 되어야 하며, 물과 토사의 혼합비율은 6:4이상이 되어야 한다. 환경적 영향 분석결과, 오염토사의 적용시 국내환경기준을 만족하는 것으로 나타났다. 또한, 수리학적 펌핑 압력에 대한 지오텍스타일 튜브의 최대 유효높이는 튜브 전체높이의 약 80%의 채움이 완료되었을 시점인 것으로 판단된다.다.

• Land and Housing Review
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• v.2 no.4
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• pp.387-395
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• 2011

According to the seismic design criteria for structural buildings in Korea, the ground is classified into 5 types based on the average shear wave velocity measured from elastic wave tests on site and seismic load applied to the structure is estimated. However, elastic wave tests in site, however, on the engineering fill, cannot be performed during the construction period. Therefore, to evaluate shear wave velocity considering field conditions, resonant column (RC) and torsional shear (TS) tests are performed and compared with various elastic wave test results. As a result, if confining pressure for the tests using engineering fill are considered properly, we can obtain similar results comparing with those of elastic wave tests. In addition, by considering the effect of maximum shear modulus and confining pressure by RC/TS tests, n values shows typical values ranging from 0.434 to 0.561 so that utilization of RC/TS tests can be useful to infer shear modulus in field.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05d
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• pp.300-305
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• 1996

격납건물용 콘크리트는 그 배합이 변경될 때마다 장기거동 특성시험 (크립, 건조수축, 탄성계수, 포아슨비, 열팽창계수 등)을 수행하여 그 시험결과를 설계회사가 텐돈의 인장 작업전까지 검토하게 되어 있으나, 이 중 크립(Creep)시험은 특성상 장기간이 소요되는 관계로 적시에 시험결과를 제공할 수 없는 경우가 종종 발생한다. 본 연구에서는 이 경우 유사한 배합비를 가진 콘크리트와의 물성치 대비 및 크립 변형율의 예측을 통하여 실험치가 허용치 이내에 드는 가를 분석하므로써, 사용된 콘크리트의 크립거동에 대한 안정성을 검토하였다.

• Journal of the Korean Geotechnical Society
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• v.23 no.8
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• pp.59-68
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• 2007

The comparative study using the lab-scale experiment and the discrete element analysis is attempted to analyze the cross-anisotropic elasticity of granular soils. The lab-scale experiment consists of the small stress-controlled triaxial cyclic tests and the bender element tests. In the discrete element analysis the simulations of lab-scale cyclic tests are conducted in the various directions. Good agreement between the experimental data and the simulation on the elastic properties in the axial and shear directions confirms the usefulness of the discrete element method. The comparative analysis of the difference in the experimental data and the simulation of radial cyclic tests shows that the discrete element method can successfully be used to check the reasonable magnitude of each measurement in the experiments.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.2
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• pp.46-53
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• 2005

We have analyzed the temperature and humidity aging test results of a composite solid propellant. The temperature aging test was performed to evaluate the storage life of a propellant, while the humidity aging test could provide the hygroscopicity of Ammonium Perchlorate(AP) exposed to .elative humidity (RH) 10, 30, $50\%$ environment. A specimen was used in the temperature test, and a block of propellant from the actual motor was used in the humidity test. We report that the 4-month storing at 60 degree is equivalent to the 10-year 60 degree condition. The composite solid propellant with HTPB binder showed signs of hardening with time lapse but the effect of humidity up to RH $50\%$ was not noticeable.

• Journal of The Korean Association For Science Education
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• v.29 no.8
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• pp.812-823
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• 2009

The purpose of this study is to search effective assessments methods by using the Fusion model of Cognitive diagnosis theory. Attributes are skills or cognitive processes that are required to perform correctly on a particular item. After test items were developed, item's attributes were decided and Q-matrix about item's attributes was made. After testing, the result was analyzed according to gender and achievement level. The results of the analysis showed that students mastered 'Interpreting data' best, and 'synthesizing' worst among the five attributes. Female students showed higher ability than male students in 'recalling.' Students of high achievement level mastered more scientific attributes than students of low achievement level. Conventional assessments only provided a single summary score but Cognitive diagnosis modeling provided useful information by estimating individual knowledge states by assessing whether an examinee has mastered specific attributes measured by the science test. The skill profiles can offer a skill level of strong, weak, or mixed for each student for each skill. Therefore, the skill profiles will provide useful diagnostic information in addition to single overall scores.

• Journal of the Korean Geotechnical Society
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• v.24 no.4
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• pp.89-100
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• 2008

Applying graph and correlation developed in other countries to the domestic field has limits. Therefore, it is necessary that Piezocone factor should be determined by including ground characteristics obtained from various test results in the domestic site for better application. In this study, laboratory tests and field tests were performed to find the characteristics of soft ground which was widely distributed around Siwha lake. A comparative analysis of these tests with Piezocone penetration test was performed and the Piezocone factor was estimated by correlationship analysis of undrained shear strength and cone resistance. Also, an appropriate Piezocone factor in the study site was reestimated by utilizing statistical analysis method for deriving reliable result.

• Economic and Environmental Geology
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• v.36 no.1
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• pp.49-58
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• 2003

To analyze the anisotropic characteristics of fractured aquifer, variations of streaming potential were measured during and after pumping over several wells at the two test sites. Surface electrical resistivity survey, normal resistivity logging, and slug test were performed at the wells to identify the hydrogeological structure. Applying the results to the recently suggested model, the aquifer of the two test sites showed confined characteristics. Anisotropic direction appeared in using equi-potential maps from self-potential monitoring results matched well with the results of the hydrogeological test. The self-potential monitoring method adopted in this study would be useful for providing a more reliable information on the anisotropy of aquifer in the pumping test at single well.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.9
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• pp.760-770
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• 2012

In order to provide precision approach service based on GBAS, air navigation service providers should validate the GBAS system performance against international standard requirements and receive approval. The GBAS manufacturer should define integrity threat, analyze the integrity monitors and evaluate performance of the implemented monitors to verify integrity performance which is critical to the aircraft safety. This paper describes a statistical test result to evaluate performance of the code carrier divergence monitors implemented in KARI Integrity Monitor System software. The paper introduces analysis and test procedure which is developed for the performance evaluation and describes the analysis, the test scenario generation and the test results. The results show that the implemented monitors can detect the expected minimum detectable errors with satisfying the probability of missed detection requirements.