• The Korean Journal of Mycology
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• v.29 no.1
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• pp.47-51
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• 2001

Obesity and lipid metabolism of SD rats were studied with an edible Nigerian mushroom, namely, Lentinus tuber-regium (Fries) Singer. Experimental diets prepared with Lentinus tuber-regium (LTR) instead of carbohydrates were fed to SD rats for 6 weeks. Body weights gain were decreased (3.2% and 29.3%, respectively) In LTR-50 and LTR-100 groups, whereas food intakes were significantly increased (24.5% and 40.7%, respectively) compared with control group. Feed efficiencies were significantly decreased (22.2% and 49.8%, respectively) in these two LTR groups, whereas gross efficiencies (GE) were increased (9.9% and 10.4%, respectively) compared with control group. The ratios of diet intake (DI)/metabolic body size (MBS) were remarkably increased (50.3% and 136.1%, respectively) in these groups. Triglyceride and LDL-cholesterol levels were significantly decreased (22.4% and 32.6%, 8.3% and 12.7%, respectively) in these two groups, but HDL-cholesterol levels were desirably increased by $3{\sim}10%$ in LTR-added groups. Atherogenic indices (Als) were significantly decreased about $8{\sim}13%$ in LTR-added groups compared with control group. These results suggest that an edible mushroom, Lentinus tuber-regium may inhibit obesity in above 50%-LTR by increasing a diet intake, GE and DI/MBS ratio, but may also effectively modulate a chronic degenerative diseases by improving a lipid metabolism.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.2
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• pp.67-73
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• 2004

Some of Spacecraft's structures are flexible so that a certain expected disturbance can easily excite a low frequency vibration on these structures, having very low natural damping. Such vibration will degrade the performance of the system, which should to be kept in a specific shape or attitude against the undesired vibration. In this paper, LQG/LTR controller is developed using an additional dynamic model to increase the performance of the frequency responses at low frequency area. This study presents that the LQG/LTR design was an effective controller for the flexible structure.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.5
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• pp.1620-1634
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• 1991

본 연구에서는 전기/자기 및 기계적 요소들이 복합되어 이루어진 자기부상 시 스템의 설현을 위한 기초단계로서 제어동역학(controlled dynamics) 측면에 입각한 모 델식을 본드선도 기법을 이용하여 보다 조직적으로 유도한다. 우선, 자속흐름 확장 및 자속 유출량을 고려하여 부상 시스템을 모델링하고 차량/레일 및 2차 현가(second ary suspension)장치를 포함한 자기부상 시스템을 모델링한다. 다음, 지지 및 안내 방향의 동역학을 동시에 고려한 2차원 자기부상 시스템을 본드선도의 다접점 필드(mu- ltiport field) 개념을 이용하여 모델링한다. 끝으로, 본드선도 기법으로 모델링된 2차원 자기부상 시스템의 안정도와 성능을 향상시키기 위하여 LOG/LTR(linear quadra- tic Gaussian control with loop transfer recovery) 제어시스템을 설계한다. LQG/ LTR 제어방법은 Doyle과 Stein에 의해 인성(stability-robustness) 문제와 주파수역 성능을 설계시에 직접 고려할 수 있는 강력한 선형 다변수 제어시스템 설곕방법으로 현재 널리 사용되고 있다.

• Journal of the Korean Society for Precision Engineering
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• v.7 no.1
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• pp.74-85
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• 1990

The LQG and LQG/LTR compensators have the same structrues in dynamics. The only difference is the values of the design parameters in the two compensators. The design parameters of the LQG and LQG/LTR compensators are selected in the sense of the least-squares error minimi- zation and loop shaping, respectively. In this paper, the LQG and LQG/ LTR design methods are applied to the helicopter in hover which is modeled as a SISO fourth order system. The dynamic characteristics and the perfor- mance of the two control systems are analyzed by the computer simulation. It is found that the LQG/LTR design method is systematic and has good performance in comparision with the LQG design method.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.5
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• pp.356-366
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• 2000

In this paper, a nonlinear $H_2/H_\infty/LTR$ control for the flexible inverted pendulum of a parallel type with Coulomb friction is presented. The dynamic equation for this system is derived by the Hamilton's principle and assumed-mode method. This hard nonlinear system can be modeled by a the quasi-linear state space model using the REF method. It is shown that the $H_2/H_\infty$ control can be applied to the nonlinear controller design of the system having Coulomb frictions if the proper LTR conditions are satisfied. In order to present the usefulness of the suggested control method, the nonlinear $H_2/H_\infty/LTR$ controller is designed to control the Position of the end point of the flexible inverted pendulum that has Coulomb frictions present in actuator parts. The results are given via computer simulations.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.11
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• pp.2730-2741
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• 1993

A mathematical model of the seeker scan-loop which is composed of a spin-stabilized gyroscope and its driving signal processors is derived. The derived model has a transmission zero pair on the imaginary axis near to the required bandwidth. The LQG/LTR design methodology is evolved for the derived scan-loop model. To implement the designed LQG/LTR compensator to the actual plant, the compensator order is reduced using the internally balanced realization method. The performances of the LQG/LTR compensator are tested and compared with those of the P-control. Especially, stability-robustnessexperiments for model uncertainties represented in the form of time-delays are performed. It is demonstrated that the LQG/STR compensator is actually very robust to model uncertainties.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.8
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• pp.965-971
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• 1999

This paper presented to design the power system stabilizer(PSS) for a turbo-generator system using LQG/LTR control synthesis for improving small-signal stability. Application study of LGG/LTR control synthesis is more appropriate in this system since a turbo-generator system is usually operated under circumstance of unmeasurable uncertainties and external disturbance. The LQG/LTR control theory was briefly reviewed for good understanding and the reasonable design approach. The design results are simulated for a case study and to check the system performance in comparison with currently operating lead-lag filtered PSS performance.

• Journal of Ginseng Research
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• v.35 no.4
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• pp.413-420
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• 2011

We investigated whether Korean red ginseng (KRG) and highly active antiretroviral therapy (HAART) affect the frequency of gross deletion in 5'LTR/gag in 20 hemophiliacs. This study is a prospective study in 20 hemophiliacs who were infected with Korean subclade B of HIV-1 from two cash-paid plasma donors in 1990. Over a 13-year period, we obtained 436 amplicons of 5'LTR/gag genes by nested polymerase chain reaction using 147 peripheral blood mononuclear cells. Of the 436 amplicons, 92 (21.1%) showed gross deletion in 5'LTR/gag. Despite of a 2.3-fold higher monthly dose of KRG intake, the frequency of gross deletion in 5'LTR/gag (16.4%) was significantly decreased during HAART compared with 28.1% prior to HAART (p<0.01). Gross deletion in 5'LTR/gag was 10% more detected on KRG-therapy than prior to KRG-therapy (p<0.05). In addition, we also obtained 28 amplicons containing premature stop codon or isoleucine at initiation codon of 254 amplicons sequenced on KRG intake (7.5%) or HAART (13.6%) compared with 0% before KRG intake. These findings indicate that high frequency of gross deletion in 5'LTR/gag and genetic defects prior to HAART are significantly associated with KRG intake and the detection of gross deletion in 5'LTR/gag is decreased by HAART.

• Animal cells and systems
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• v.5 no.3
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• pp.243-246
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• 2001

Human endoqenous retroviral long terminal repeats (LTRs) have been found to be coexpressed with sequences of genes closely located nearby. It has been suggested that the LTR elements have contributed to structural changes or genetic variations of human genome connected to various diseases and evolution. Using cDNA library derived from placenta tissue, we performed PCR amplification and identified five new HERV-W LTR elements. Those LTR elements showed a high degree of sequence similarity (98-99%) with HERV-W LTR (AF072500). A phylogenetic tree obtained by the neighbor-joining method revealed that HERV-W LTR elements could be mainly divided into two groups through evolutionary divergence. Five new HERV-W LTR elements (pla-1, 4, 5, 6, 7) belonged to the group I with AX000960, AF072504, and AF072506 from GenBank database. The data suggest that several copy numbers of the HERV-W LTR elements are transcribed in placenta and may contribute to the understanding of biological function such as human placental morphogenesis.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.88-94
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• 1993

In this paper we analyze the RHLQG/FIRF optimal.contol law presented in [4,5] in order to stabilizes a stochastic linear time varying systems with modeling uncertainty. It is shown by the frequency domain analysis that the RHC is robuster than the LQ control law. Explicit LTR procedures are given to improve the robust performance of RHLQC/FIRF cotrol law. Using the mismatching function technique [8], we propose an LTR method which makes the RHLQG/FIRF controller recover the feedback properties of the R.HC law. Also we compare the LTR performance of the RHLQC/FIRF via simulation with conventional LTR methods.