• 대한기계학회논문집B
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• 제29권3호
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• pp.295-305
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• 2005

To improve the aerodynamic effciency of TR-E2, a new configuration so called TR-E2Sl was introduced. TR-2251 is composed of different wing airfoil section and T-tail shape compared with TR-E2. Wind tunnel test for TR-EBS1 had been performed by changing the incidence angles of wing and deflection angles of control surfaces such as elevator and rudder. Also the on/off effect of ventral fin attached underneath of AFT fuselage was tested. Test result showed that variations of wing incidence angle did not cause any severe differences in aerodynamic characteristics. Longitudinal and directional characteristics of TR-E2S1 show stable for the pitch and yaw motions. However, the lateral stability of TR-E2S1 is not stable for a certain control surface deflection.

• Structural Engineering and Mechanics
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• 제29권1호
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• pp.77-89
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• 2008

Presence of high degree of orthotropy enhances shear lag phenomenon in laminated composite box-beams and it persists till failure. In this paper three key parameters governing shear lag behavior of laminated composite box beams are identified and defined by simple expressions. Uniqueness of the identified key parameters is proved with the help of finite element method (FEM) based studies. In addition to this, for the sake of generalization of prediction of shear lag effect in symmetrical laminated composite box beams a feed forward back propagation neural network (BPNN) model is developed. The network is trained and tested using the data base generated by extensive FEM studies carried out for various b/D, b/tF, tF/tW and laminate configurations. An optimum network architecture has been established which can effectively learn the pattern. Computational efficiency of the developed ANN makes it suitable for use in optimum design of laminated composite box-beams.

• Journal of Magnetics
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• 제12권4호
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• pp.161-164
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• 2007

Constant temperature regulation of a hybrid heater which is composed of a temperature sensitive ferrite with low permeability and a Cu tube is investigated for hyperthermia. The temperature sensitive ferrite is inserted into a Cu tube and its length and diameter are 10 mm and 3 mm. Below B=0.05 T, the measured temperature and the calculated one increased with the ratio of $B^{1/2}$ and agreed well with each other. Above B=0.05 T, the measured temperatures maintained constantly almost $50^{\circ}C{\pm}1.5^{\circ}C$ because of the influence of Curie temperature of the temperature sensitive ferrite. This result shows that the hybrid heater is able to regulate the temperature constantly at the rate of $50^{\circ}C{\pm}1.5^{\circ}C$.

• 한국가금학회지
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• 제28권3호
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• pp.231-237
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• 2001

육계를 13주간 사육하면서 5주령부터 시험사료를 급여한 후 세포표면항원의 발현에 미치는 영향을 측정하기 위하여, 아마종실과 항산화제를 첨가하지 않은 대조구($T_{1}$ ), 아마종실만을 첨가한 사료($T_{2}$ ), 아마종실과 u-toco-pherol을 첨가한 사료($T_{3}$ ), 아마종실에 u-tocopherol과 셀레늄을 첨가한 사료($T_{4}$ )를 육계에 급여한 바 면역반응에 미치는 영향은 다음과 같았다. 1차 면역에 관여하는 monocyte 군은 시험사료의 급여기간이 증가할수록 $T_{1}$ 에 비하여 $T_{2}$ , $T_{3}$ , $T_{4}$ 구에서 유의적으로 증가하는 경향을 보였는데 그중 $T_{2}$ 구와 $T_{3}$ 구에서 많이 증가되었다. B세포는 시험사료의 급여기간보다는 급여사료에 따라 증가하였는데,$T_{2} , $T_{3}, $T_{4}$ 구는 $T_{1}$ 구에 비하여 2배 이상 증가하였다. CD4 양성반응(T helper cell)과 CD8 양성 세포(T $cytotoxic^pressor cell)는 $T_{2}$ , $T_{3}$ ,$T_{4}$ 구는 $T_{1}$ 구보다 증가하였으나 사료에 따라 일정한 차이는 없었다. MHC classII는 시험사료의 종류나 급여 기간에 따라 차이는 없었다.었다.

• 대한한방체열의학회지
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• 제3권1호
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• pp.6-14
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• 2004

Purpose: We intended to research the relations between abdominal temperature and primary dysmenorrhea severity. Methods: We selected the 95 primary dysmenorrhea patients by means of screening test (first screening test-inquiry, second screening test-clinical test, additionally Waist-to-Hip ratio (WHR) by Inbody 2.0). We measured 4 points abdominal temperature (Chon-jung(CV17), Chung-wan(CV12), Kwan-won(CV4), Chung-guk(CV3)) by DITI (DOREX Inc., USA). And then we checked the difference of temperature $({\Delta}T)$ between CV17 and CV4 / CV17 and CV3 / CV12 and CV4 / CV12 and CV3. After that, we compared ${\Delta}T$ with primary dysmenorrhea severity evaluated by multidimensional scales (verbal rating scale modified from the one devised by Bibe roglu & Berhrman(VRS; B&B), multidimensional verbal rating scale by Andersch & Milsom(MVRS)). In dysmenorrhea severity, we standardized scale score and 3-group-severity by score (mild, moderate, severe). For statistics, we used Pearson correlations and Spearman's rho correlations, SPSS 11.0 for windows. Results: In case of MVRS, MVRS score and 3-group-severity were not correlated to ${\Delta}T$. In case of VRS; B&B, VRS; B&B score was correlated to ${\Delta}T$ (CV12 and CV4 / CV12 and CV3) and 3-group-severity was correlated to ${\Delta}T$ (CV12 and CV3). Statistically they showed significant result (p<0.05). So we can consider that ${\Delta}T$ (CV12 and CV3) and the primary dysmenorrhea severity by VRS; B&B are most correlated. Conclusion: The primary dysmenorrhea patients showed that severity by VRS; B&B was connected with ${\Delta}T$ (CV12 and CV3). So we can consider DITI as primary dysmenorrhea evaluation instrument and must further research measurement points for the exact primary dysmenorrhea evaluation by DITI.

• 농업과학연구
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• 제47권1호
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• pp.131-138
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• 2020

The aim of this study was to evaluate the effect of aflatoxin B₁ (AFB₁) on in vitro rumen fermentation at various dose levels of 0 (T₁), 100 (T₂), 200 (T₃), and 300 (T₄) ppb in a wheat straw-based buffalo diet. The results show that the truly degradable dry matter, truly degradable organic matter, gas production, microbial biomass production and partitioning factor values in the control group (T₁) were higher (p < 0.05) than those of the T₂, T₃, and T₄ groups. The total volatile fatty acids, acetate, propionate, and butyrate values in the control group (T₁) were higher (p < 0.05) than those of the T₂, T₃, and T₄ groups. The partitioning factor value in the control group (T₁) was higher (p < 0.05) than those of the T₂, T₃, and T₄ groups. The partitioning factor values of the T₂ and T₃ groups were higher (p < 0.05) than that of the T₄ group. There was no significant variation in the partitioning factor value between the T₂ and T₃ group. The acetate : propionate (A : P) ratio in the control group (T₁) was lower (p < 0.05) than those of the T₂, T₃, and T₄ groups. The A : P ratio in the T₂ group was lower (p < 0.05) than those of the T₃ and T₄ groups. It was concluded that different levels of AFB₁ contamination in feed significantly affect the in vitro rumen fermentation characteristics. Thus, these findings could help to determine the influences of AFB₁ in a wheat straw-based buffalo diet. Additionally, it is necessary to manage AFB₁ contamination in ruminants.

• 한국자기학회지
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• 제17권4호
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• pp.162-165
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• 2007

본 연구에서는 CoFeB/MgO/CoFeB 구조를 가지는 자기터널접합에서 capping층 재료의 종류와 열처리 시간에 따른 비정질 top CoFeB 자성층의 결정화 상태 및 자기터널접합의 자기적 특성 변화에 대한 연구결과를 비교 분석 하였다. Hcp(Hexagonal close-packed)의 결정구조를 가지는 Ru(002)를 capping층 재료로 사용한 자기터널접합 박막의 경우에는 열처리 이후 Ru과 인접한 부분의 top CoFeB이 bcc-CoFe(110)로 성장하는 반면, TiAl과 ZrAl을 capping층 재료로 사용한 자기터널접합의 경우는 열처리 이후 top CoFeB이 MgO와 epitaxial하게 bcc-CoFe(002)로 결정성장 하였다. 이로 인해 Ru을 사용한 자기터널접합의 터널자기 저항비(46.7%)보다 약 1.5배 높은 터널자기저항비(TiAl: 71.8%, ZrAl: 72.7%)를 나타내었다.

• 한국분무공학회지
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• 제23권4호
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• pp.185-191
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• 2018

Benzene, toluene, ethylbenzene and xylene (BTEX) were well known as ozone precursors from photochemical reactions and contribute to the formation of photochemical smog which pose health hazards. Also, some of these compounds directly affect the human health due to their toxicity such as benzene. In this study, BTEX ratios and correlation of $C_2$-benzenes (xylenes, ethylbenzene) in vehicle exhaust from recreational vehicle (RV) and multi-purpose vehicle (MPV) were characterized using a chassis dynamometer. VOCs were collected by tedlar bag and a GC/MS system was used for their quantification. Among all of the BTEX, toluene has the highest concentration(more than 30% in composition of BTEX). The average ratio of toluene to benzene emissions (T/B ratio=2.2) was found in vehicle exhaust. The average m,p-xylene/ethylbenzene and m,p-xylene/o-xylene ratios were 1.0 and 3.0 respectively. As a result, it showed a good correlation between the $C_2$-benzenes ($R^2=0.98{\sim}0.99$). In the future, it can be used as a marker for effect evaluation to atmospheric environment by vehicle exhaust.

• 한국통신학회논문지
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• 제30권12A호
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• pp.1183-1187
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• 2005

본 논문에서는 5.15-5.35GHz Wireless LAN 대역의 사용을 위한 Weathercock-Shaped의 마이크로스트립 패치 안테나에 대하여 설계 및 제작하였다. 이동성을 위해 소형화하였고 Weathercock패치 모양에 T-Slot을 삽입하여. 적절한 대역폭을 얻고자 하였다. 시뮬레이션 설계는 Weathercock 모양과 T-Slot의 길이, 폭 그리고 급전위치를 최적화하여 제작 및 측정하였고 단일 양면 기판만을 사용해서 제작하였다. 실제 제작된 안테나의 측정결과는 Voltage Standing Wave Ratio (VSWR) < 2에서 $7.62\%$의 대역폭과 5.25${\~}$6.70dBi의 Gain을 얻었으며 3-dB 빔폭은 Azimuth와 Elevation이 각각 $80.32^{\circ}$와 $83.88^{\circ}$이 측정되었다.

• 한국방사선학회논문지
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• 제15권4호
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• pp.565-573
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• 2021

인체 내 전자기장의 공간 분포는 고 유전율 재료를 사용하여 비교적 간단하게 조정할 수 있다. 이 방법은 다른 방법에 비해 보완적인 성격이 강하지만 특정 응용 분야에서 강력한 유전체 시밍용 도구로 활용될 수 있다. 기하학적으로 자유로운 형상으로 제조 가능하며 시스템의 어떠한 변경 없이 목적에 따라 제작된 패드를 적용할 수 있다. 특히 초 고자장(ultrahigh magnetic field UHF) MRI에서 높은 작동 주파수로 인해 낮은 감도 (low sensitivity)를 갖는 송신 (B1+) 및 수신 (B1-) 필드의 강도를 높이는 데 사용되는 임상목적의 고 유전율 패드는 잠재적 가치가 상당히 클 뿐만 아니라 그 효과가 클 것으로 예상되는 UHF MRI에 적용된 연구가 적기 때문에 이 연구에서는 티탄산 칼슘의 현탁액으로 제조된 고 유전율 패드를 실험실에서 직접 개발하였으며 UHF 7T 자기공명영상 MRI의 다양한 프로토콜에서 임상적으로 유용한 영상의 신호증가를 확인하였다.