• 대한인간공학회지
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• 제24권2호
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• pp.79-83
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• 2005

In order to verify the effects of sleep efficiency and sleep latency depending on the sound, Polysomnography was carried for the different sound stimulations, such as Sound A(providing R bed Co.), Sound B(1/f fluctuation sound develope by KRISS), and no sound stimulation. In case of sleep efficiency and WASO(wake after sleep onset) ratio Sound B shows more affirmative effect than no sound stimulation or Sound B. It is the result that the effect is caused because 1/f fluctuation sound has the rule and unexpectation. This research results show the possibility of application and development of the sound for sleep.

• 대한수의학회지
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• 제33권4호
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• pp.591-596
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• 1993

The smear preparations of the semen from Korean native bull and the tissue preparations of the organs from male and female mice were performed by fluorescent staining method. More than 600 spermatozoa per straw from two semen straw groups and more than 300 cells per mouse organ from two mice per sex were observed and then the ratio of spermatozoa bearing B-body and the cells bearing F-body were assessed, respectively. 1. The ratios of spermatozoa bearing B-body in semen of Korean native bull were $37.3{\pm}3.1%$. 2. The ratios of cells bearing F-body in the organs of mice were $63.5{\pm}4.5%$ in male tissues and $7.5{\pm}3.2%$ in female tissues. 3. The organs with higher appearance frequency of F-body were ordered as brain, kidney, stomach, lung, testis, liver, small intestine, spleen and pancreas in male mice and pancreas, small intestine, liver, brain, kidney, lung, spleen and stomach in female mice.

• BMB Reports
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• 제34권6호
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• pp.496-501
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• 2001

Lincomycin, an inhibitor of plastid protein synthesis, was found to block the synthesis of apoprotein P700 with a molecular mass of 72 kDa and the assembly of the Chl a-protein of PS I. Synthesis of the polypeptides of 48, 43.5, and 32 kDa of the PS II complex is also suppressed. This process is accompanied by the disappearance of the PS Two reaction center Chl a at 683 nm, and of the PS One reaction center Chl a at 690, 696, and 705 nm on the fourth derivative of the absorption spectra at 77K. Lincomycin does not affect the synthesis of LHC subunits. It increases the content of the two main Chl forms of LHC at 648 nm (Chl b) and 676 nm (Chl a). The low-temperature fluorescence ratio F736/F685 is also increased. However, the effect of cycloheximide (an inhibitor of cytoplasmic protein synthesis) leads to the reduction of polypeptides of the light-harvesting Chl a/b-protein complex in the range of 29.5-22 kDa. Under these conditions, the relative amount of Chl b and the F736/ F685 fluorescence ratio decrease significantly. This is obviously the result of blocking the LHC I and LHC II synthesis. At the same time rifampicin and actinomycin D (inhibitors which block transcription in chloroplast and nuclear genome, respectively) inessentially affect the characteristics of these complexes.

• 한국분말재료학회지
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• 제23권6호
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• pp.437-441
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• 2016

Recently, the grain boundary diffusion process (GBDP), involving heavy rare-earth elements such as Dy and Tb, has been widely used to enhance the coercivity of Nd-Fe-B permanent magnets. For example, a Dy compound is coated onto the surface of Nd-Fe-B sintered magnets, and then the magnets are heat treated. Subsequently, Dy diffuses into the grain boundaries of Nd-Fe-B magnets, forming Dy-Fe-B or Nd-Dy-Fe-B. The dip-coating process is also used widely instead of the GBDP. However, it is quite hard to control the thickness uniformity using dip coating. In this study, first, a $DyF_3$ paste is fabricated using $DyF_3$ powder. Subsequently, the fabricated $DyF_3$ paste is homogeneously coated onto the surface of a Nd-Fe-B sintered magnet. The magnet is then subjected to GBDP to enhance its coercivity. The weight ratio of binder and $DyF_3$ powder is controlled, and we find that the coercivity enhances with decreasing binder content. In addition, the maximum coercivity is obtained with the paste containing 70 wt% of $DyF_3$ powder.

• Preventive Nutrition and Food Science
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• 제5권4호
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• pp.230-233
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• 2000

The present work was designed to determine whether change in fluidity of the mitochondrial membrane affects mitochondrial {TEX}$F_{1}${/TEX}{TEX}$F_{0}${/TEX}ATPase characteristics in NIDDM-prone BHE/Cdb rat. Isolated mitochondria fom BHE/Cdb rat fed a 6% coconut oil or corn oil were functionally tested by an analysis of its respiration and the coupling of this process to ATP synthesis in presence of oligomycin, a specific inhibitor of oxidative phosphorylation (OXPHOS), that binds to the {TEX}$F_{1}${/TEX}{TEX}$F_{0}${/TEX}ATPase. Mitochondria from rats fed coconut oil were more responsive to the inhibitory action of oligomycin with respect to state 3 respiration, respiratory control (RC) ratio and ADP:P (P/O) ratio than were mitochondria from rats fed corn oil. In state 3 respiration, mitochondria from rats fed coconut oil consumed less oxygen than did mitochondria from rats fed corn oil. RC ratio was lower in the mitochondria from rats fed coconut oil than was mitochondria from rats fed corn oil. In P/O ratio, the mitochondria from rats fed coconut oil had a lower P/O ratio than did mitochondria from rats fed corn oil. The data showed that the chang influidity of the mitochondrial membrane by dietary fat affected mitochondrial {TEX}$F_{1}${/TEX}{TEX}$F_{0}${/TEX}ATPase characteristics. The present study on diet differences in {TEX}$F_{1}${/TEX}{TEX}$F_{0}${/TEX}ATPase characteristics provides considerable insight into the role diets play in the control of mitochondrial function, expecially OXPHOS in NIDDM with mitochondrial defects.

• 분석과학
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• 제23권5호
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• pp.465-476
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• 2010

본 연구에서는 대기환경시료 및 현장조건에서 채취한 현장시료들 중, 악취성분 및 주요 VOC 성분들 중에서 여러 유형의 관리대상으로 지정 중인 benzene, toluene, p-xylene, styrene, methyl ethyl ketone의 농도분석 방식들을 비교하였다. 이때, GC/FID와 튜브를 연계한 F-T 분석방식과 GC/MS와 백(bag)을 연계한 M-B방식으로 같은 시료를 각각 분석하고 이들 결과 값을 비교하였다. 상관분석결과, toluene과 pxylene에서 F-T와 M-B방법간의 결과에서 큰 상관성을 보이는 것으로 나타났다(P < 1.4E-08). 양 기기간의 오차를 percent difference (PD)와 같이 산술적으로 구하여 평가한 결과, benzene과 toluene의 농도는 상대적으로 비슷한 경향을 보였다. 그러나 분석대상 성분들 간에 양 방식의 차이는 평균적으로 35%가 넘으면서 F-T와 M-B간의 오차가 일정 수준이상으로 존재하였다. 그리고 F-T/M-B ratio가 대부분 1 이하로 나타나면서, M-B의 결과 값이 F-T에 비해 상대적으로 크게 나타나는 경향을 보였다. 양 분석기기로부터 산출한 결과 값을 통계적으로 판단하기 위해, t-test를 실시하였다. 그 결과, 95% 신뢰수준에서 toluene, pxylene, styrene, methyl ethyl ketone 성분에서는 두 시스템간의 결과 값에 차이가 유의한 것으로 나타났다(P < 0.043). 그러나 전반적으로 양 분석기법의 차이에 따른 오차는 상당 부분 선택한 표준시료의 성상 및 백내부의 시료손실 등과 같은 요인에 크게 영향을 받는 것으로 나타났다.

• Wind and Structures
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• 제38권1호
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• pp.59-74
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• 2024

Large Eddy Simulation (LES) is used to explore the influence of vibration frequency and amplitude on the aerodynamic performance of a rectangular cylinder with an aspect ratio of B/D=5 (B: breadth; D: depth of cylinder) at a Reynolds number of 22,000 near resonance frequency. In smooth flow conditions, the research employs a sequence of three-dimensional simulations under forced vibration with diverse frequency ratios f_e / f_o = 0.8-1.2 (f_e : oscillation frequency; f_o : Strouhal frequency when the rectangular cylinder is stationary ) and oscillation amplitudes A_h/D = 0.05 - 0.3. The individual influences of f_e / f_o and A_h/D on the characteristics of integrated and distributed aerodynamic forces are the focal points of discussion. For the integrated aerodynamic force, particular emphasis is placed on the analysis of the dependence of velocity-proportional component C₁ and displacement-proportional component C₂ of unsteady aerodynamic force on amplitude and frequency ratio. Near the resonance frequency, the dependencies of C₁ and C₂ on amplitude are stronger than that of frequency ratio. For the distributed aerodynamic force, the increase in frequency and amplitude promotes the position of the main vortex core and reattachment to the leading edge in the streamwise direction. In the spanwise direction, vibration enhances the spanwise correlation of aerodynamic force to weaken the three-dimensional effect of the flow field, and a lower frequency ratio and larger amplitude amplify this effect.

• Journal of electromagnetic engineering and science
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• 제6권3호
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• pp.189-195
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• 2006

In this paper, the derivation of the protection ratio for the digital microwave system with diversity is newly suggested for a basic guidance of initial planning for frequency coordination, and computational results are presented for an actual radio frequency band. The net filter discrimination has been also examined to see the effect of the adjacent channel protection ratio caused by adjacent channel interference. In addition, the protection ratios for the space or frequency diversity system are analyzed in terms of diversity improvement factors to find out an equivalent allowable noise-to-interference ratio (N/I) from degraded fade margin. According to results for 6.2 GHz system, with the space diversity of 25 m distance between antennas or the frequency diversity of ${\Delta}f/f=0.05$, under 64-QAM and 60 km at BER $10^{-6}$, the protection ratio can be greatly reduced in comparison to the non-diversity system. So, assuming that only the same protection ratio as the non-diversity system is kept, it is shown that the system with diversity may get more interference level of N/I allowing from 9.0 to - 5.9 dB or from 6.0 to - 4.3 dB for the space or frequency diversity. In consequence, it is concluded that the diversity system is more robust or tolerable for interferences or fades, which may play an important role in overcoming N/I to some extent.

• 농업과학연구
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• 제8권2호
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• pp.179-184
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• 1981

흙댐 및 자연사면(自然斜面)의 안정해석(安定解析)에 가장 많이 사용(使用)되는 Fellenius방법(方法)과 Bishop방법(方法)을 비교검토(比較檢討)하여 다음과 같은 결과(結果)를 얻었다. 1. 정상침투상태(定常浸透狀態)에서 Bishop방법(方法)이 Fellenius 방법(方法)보다 안전율(安全率)이 11~29%정도(程度) 큰 값을 나타냈다. 2. Bishop방법(方法)이 Fellenius방법(方法)보다 안전율(安全率)이 증대(增大)되는 비율(比率)($F_B-F_F/F_F$)은 경사면(傾斜面)의 기울기가 느릴수록 감소(減少)하는 경향(傾向)을 나타냈다. 3. 침투(浸透)가 없을때와 있을때의 안전율(安全率)이 증대(增大)되는 비율(比率)($F_1-F_2/F_2$)은 경사면(傾斜面)의 기울기가 느릴수록 증가하는 경향(傾向)을 나타냈다.

• 한국공작기계학회논문집
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• 제10권4호
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• pp.14-21
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• 2001

To estimate crack growth rate and cycle ratio uniquely, many investigators have developed various kinds of mechanical parameters and theories. But, thes have produced local solution space through single parameter. Neural Networks can perform patten classification using several input and output parameters. Fatigue damage model by neural networks was used to recognize the relation between da/dN/N/N(sub)f, and half-value breadth ratio B/Bo, fractal dimension D(sub)f, and fracture mechanical parameters in 2024-T3 aluminium alloy. Learned neural networks has ability to predict both crack growth rate da/dN and cycly ratio /N/N(sub)f within engineering estimated mean error(5%).