• 대한기계학회논문집
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• 제18권2호
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• pp.278-291
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• 1994

A computer-aided robust design (CARD) technique is developed to search for the design variables, optimal as well as robust in the sense of Taguchi method. The CARD technique can effectively handle inequality problems by employing the variable penalty method, and dynamic problems with many design variables and/or with mixed discrete and continuous variables. It is also capable of providing contributions of each design variables to the object funtion and information for future designs. As the illustrative examples, two dynamic systems, engine mounting system and in-line feeder, are treated.

• 전기학회논문지P
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• 제59권4호
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• pp.364-371
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• 2010

In this paper, we propose the landscape lighting power control system with solar sell generator equipment for energy saving, and also which is included the landscape lighting power transformation device. The power transformation device can check inverse current in the power of the solar cell module and control the power of the battery. And we present the design of landscape lighting power control system. The power control system uses microprocessor with charging system and power transformation device. And also it can control the power of loads under consideration intensity of illumination. The landscape lighting loads are composed of LED(Lighting Emitting Diode) and HID(High Intensity Discharge)lamps. To evaluate property, we installed the solar cell array which generate three kilo watt power. Experimental results show that the proposed system can have stability and energy saving on the mixed configuration of electric loads with DC and AC lamps.

• Communications for Statistical Applications and Methods
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• 제12권2호
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• pp.335-348
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• 2005

The rapid development of microarray technologies enabled the monitoring of expression levels of thousands of genes simultaneously. Recently, the time course gene expression data are often measured to study dynamic biological systems and gene regulatory networks. For the data, biologists are attempting to group genes based on the temporal pattern of their expression levels. We apply the consensus clustering algorithm to a time course gene expression data in order to infer statistically meaningful information from the measurements. We evaluate each of consensus clustering and existing clustering methods with various validation measures. In this paper, we consider hierarchical clustering and Diana of existing methods, and consensus clustering with hierarchical clustering, Diana and mixed hierachical and Diana methods and evaluate their performances on a real micro array data set and two simulated data sets.

• 한국터널지하공간학회 논문집
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• 제25권6호
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• pp.403-421
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• 2023

도심지 내 지하구조물 개발의 필요성이 증가함에 따라, TBM 터널 시공 중 터널 굴진면 전방예측에 대한 연구가 꾸준하게 진행되고 있다. 본 연구에서는 TBM 터널 굴착 중 복합지반을 조우하는 상황을 모사한 유한요소(finite element) 수치해석 모델을 개발하였다. 개발된 수치해석 모델은 이론해와 실내실험으로부터 측정된 전기 비저항 결과값과의 비교를 통해 그 성능을 검증하였다. 이후 실제 터널의 형상과 지반조건, 측정전극의 배열 조건 등 전기 비저항 탐사에 대한 영향 변수를 설정하고 이에 따른 매개변수 해석을 수행하였다. 그 결과, 복합지반 내 경계면의 경사가 가파를수록, 복합지반을 구성하는 두 지반 사이의 전기 비저항 차이가 클수록, TBM 굴착 중 전기 비저항 측정값이 더 급격하게 변화함을 확인하였다. 또한, 보다 효율적이고 정확한 복합지반 예측을 위해 적절한 전극 간격 및 전극 배열 위치 선정의 중요성을 제고하였다. 결론적으로, 본 연구에서 개발된 수치해석 모델을 통한 터널 막장면 전방 복합지반 예측은 TBM 터널 시공 과제의 구조적 안정성과 경제적 효율성 증대에 이바지할 것으로 사료된다.

• 센서학회지
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• 제27권4호
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• pp.232-236
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• 2018

A radiation detection sensor was developed and characterized by combining three types of CsI(Tl) scintillators and an array-type SiPM to detect the radioactive contamination of discharged water in real time. The characterization results showed that type 3 exhibited the most desirable characteristics in response linearity (R-square: 0.97889) according to detection sensitivity and incident radiation dose. Furthermore, in terms of spectral characteristics, type 3 exhibited 16.54% at 0.356 MeV (the emission gamma ray energy of $^{133}Ba$), 10.28% at 0.511 MeV (the emission gamma ray energy of $^{22}Na$), 9.68% at 0.356 MeV (the emission gamma ray energy of $^{137}Cs$), and 2.55% and 4.80% at 1.173 MeV and 1.332 MeV (the emission gamma ray energies of $^{60}Co$), respectively. These measurements confirmed the good energy characteristics. The results were used to evaluate the spectral characteristics and energy linearity in a mixed source using type 3 with the best detection characteristics. It was confirmed that the gamma ray peaks of $^{133}Ba$, $^{22}Na$, $^{137}Cs$, and $^{60}Co$ were well resolved. Moreover, it was confirmed that R-square, which is an indicator of energy linearity, was 0.99986. This indicates a good linearity characteristic. Based on this study, further commercialization studies will contribute to measurements in real time and to the management of the contamination caused by radioactive wastewater or radioactive material leakage, which originate from facilities that use radioactive isotopes or care facilities.

• 한국전자파학회논문지
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• 제9권6호
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• pp.813-823
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• 1998

본 논문은 비분리형 비등방성 완전정합충(UAPML)을 이용하여 이동통신용 원형편파 등각 마이크로스트립 패치 안테나를 해석하였다 또한 3차원 U따까1L에 대한 모서리 및 모퉁이 부분에 대하여 특별히 다루었다. 특히 동축 여기선을 갖는 마이크로스트립 패치 안테나를 해석하기 위해서 Mur의 1차 흡수경계조건을 혼합 적용하였다 결과적으로 본 논문은 UAPML법이 모서리 및 모퉁이 부분에서 수렴함은 물론 Mur의 1차 흡수 경계조건과 혼합하여 홈수경계조건으로서 충분히 사용 가능함을 제시한다. 수치해석 결과는 이동통신 대역인 L밴드 및 C 밴드에서 중심주파수 1.575 GHz, 1.778 GHz 그리고 4.8 GHz를 갖는 단일 및 병렬 패치에 대한 전자장의 $E_z$및 $H\chi$에 대한 시간응답, 동축선의 입력임피던스 및 마이크로 스트립 패치의 복사특성을 해석 하였다 본 논문의 해석 결과는 2차 분산 경계조건(SDBC) Mur의 1차 흡수경계조건을 혼합한 수치해석 방법 그리고 순수 Mur의 1차 흡수경계조건과 비교하였다. 따라서 본 논문에서 제시된 해석방법이 합당함을 입 증할 수 있다.

• 대한약침학회지
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• 제18권1호
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• pp.44-55
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• 2015

Objectives: Scolopendra subspinipes mutilans (S. subspinipes mutilans) is known as a traditional medicine and includes various amino acids, peptides and proteins. The amino acids in the pharmacopuncture extracted from S. subspinipes mutilans by using derivatization methods were analyzed quantitatively and qualitatively by using high performance liquid chromatography (HPLC) over a 12 month period to confirm its stability. Methods: Amino acids of pharmacopuncture extracted from S. subspinipes mutilans were derived by using O-phthaldialdehyde (OPA) & 9-fluorenyl methoxy carbonyl chloride (FMOC) reagent and were analyzed using HPLC. The amino acids were detected by using a diode array detector (DAD) and a fluorescence detector (FLD) to compare a mixed amino acid standard (STD) to the pharmacopuncture from centipedes. The stability tests on the pharmacopuncture from centipedes were done using HPLC for three conditions: a room temperature test chamber, an acceleration test chamber, and a cold test chamber. Results: The pharmacopuncture from centipedes was prepared by using the method of the Korean Pharmacopuncture Institute (KPI) and through quantitative analyses was shown to contain 9 amino acids of the 16 amino acids in the mixed amino acid STD. The amounts of the amino acids in the pharmacopuncture from centipedes were 34.37 ppm of aspartate, 123.72 ppm of arginine, 170.63 ppm of alanine, 59.55 ppm of leucine and 57 ppm of lysine. The relative standard deviation (RSD %) results for the pharmacopuncture from centipedes had a maximum value of 14.95% and minimum value of 1.795% on the room temperature test chamber, the acceleration test chamber and the cold test chamber stability tests. Conclusion: Stability tests on and quantitative and qualitative analyses of the amino acids in the pharmacopuncture extracted from centipedes by using derivatization methods were performed by using HPLC. Through research, we hope to determine the relationship between time and the concentrations of the amino acids in the pharmacopuncture extracted from centipedes.

• 터널과지하공간
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• 제29권4호
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• pp.243-261
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• 2019

미소진동기술을 활용한 계측 및 안전관리는 전통적인 방법에 비해 우수성이 인정되어 국내외 광산 등에서 활용되고 있다. 그러나 국내 지하광산의 비정형화와 채굴적과 암반 등이 혼재한 복잡한 구조는 미소 진동 전파속도 산정과 미소진동 신호의 초동발췌를 어렵게 한다. 본 연구에서는 여러 초동발췌방법과 차원에 따른 음원위치의 결정에 대해 실험적 연구를 수행하였다. 초동발췌방법은 FTC(First Threshold Cross), Picking window, AIC(Akaike Information Criterion)을 사용하였으며, 2차원 센서 배열일 때 2차원과 3차원 음원발생 실험을 수행하였다. 각 실험에서 음원위치결정 알고리즘은 반복법과 유전자 알고리즘을 사용하였다. 반복법은 센서 배열과 음원발생이 동차원인 경우 효과적이나 음원발생이 상위차원인 경우에는 적합하지 않았다. 반면, RCGA를 이용한 음원위치결정의 경우 상위차원 음원위치를 결정할 수 있었으나 계산속도가 다소 느렸다. 초동발췌방법의 정확도는 음원위치결정 방법에 따라 다르게 나타났으나, Picking window가 전반적으로 높은 정확도를 나타냈다.

• Journal of Ecology and Environment
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• 제38권3호
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• pp.343-352
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• 2015

The landscape setting of a habitat strongly influences the distribution, abundance, and species composition of waterfowl. Thus, habitat assessment is very important to understand the habitat characteristics that sustain waterfowl assemblages. In this study, we hypothesized that the excessive use of artificial materials when new wetlands are constructed negatively influences wintering waterfowl. To test this hypothesis, we measured environmental factors, assessed habitat, and investigated waterfowl at 13 artificial wetlands in the Nakdong River Basin. There were greater numbers of waterfowl species and individuals in artificial wetlands with high habitat assessment scores. In contrast, environmental factors did not affect waterfowl distribution. In particular, features of natural habitats, such as macrophytes and sandbars, and the surrounding land-use patterns were important factors for sustaining waterfowl assemblages in each created wetland. Our results show that promoting naturalness in wetlands and surrounding areas would increase the species diversity and abundance of waterfowl. Further, complex habitats, such as wetlands and some terrestrial habitats, support both aquatic and terrestrial species because mixed habitats feature a larger array of food sources than more limited habitats do.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권11호
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• pp.550-554
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• 2001

$(Ba_{0.6}Sr_{0.4}Ca_x)TiO_3 + yAl_2O_3$ wt% (x=0.10, 0.15, 0.20, y=0~3.0) ceramics were fabricated by the mixed-oxide method, and their structural and dielectric properties were investigated with variation of composition ratio and $Al_2O_3$ doping content. As results of the X-ray diffraction and microstructure analysis, all BSCT specimens showed dense and homogeneous structure without presence of the second phase. The sintered density was decreased with an increase of $Al_2O_3$ doping content. The Curie temperature and relative dielectric constant at room temperature were decreased with increasing $Al_2O_3$doping content. The dielectric loss is minimum at BSCT doped with 1.5wt% $Al_2O_3$content. The tunability was decreased with increasing an Ca content and the BSCT(50/40/10) specimen doped with 2.0wt% $Al_2O_3$content showed the maximum value of 4.2%.