• Journal of the Korean Society for information Management
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• v.11 no.2
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• pp.3-29
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• 1994

Problems encountered under the (TDF) transdorder data flow and the current insights of overseas information services which have considerable influences to the domenstic information market are discussed. The various organizations which provide the oversears database services and do bridge role to the domestic users are investigated. The current Internet connectivities by non-profit members as well as commercial sectors for the overseras information services are also discussed. Attention is given to that the overseas information services must be understood and proceeded in the perspective of TDF and of the considerable problems implicated, and that the researchers having interests about information services must have an idea to the information sovereignty.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.52 no.2
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• pp.74-80
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• 2003

In this paper, a robust two-degree-of-freedom(TDF) the speed control system using $H_{\infty}$ optimization method and real genetic algorithm is proposed for the robust stability and the robust performance in dc servo motor system. This control system composed of feedback and feedforward controller. The feedback(FB) controller with $H_{\infty}$ optimization method is designed for real genetic algorithm that is model matching problem using mixed sensitivity function. The feedforward(FF) controller with $H_{\infty}$optimization method is minimized the error between transfer function of the optimal model and the overall transfer function. The proposed robust two-degree-of-freedom speed control system is simulated to the dc servo motor. By the simulation, feedback controller can obtain the robust stability property and feedforward controller can obtain the robust performance property under modelling error. The performance of the dc servo motor is analyzed by the experiment setting. The validity of the proposed method is verified through being compared with pid(proportional integrated differential)control system design method for the dc servo motor.

• Korean Journal of Community Nutrition
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• v.10 no.1
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• pp.12-21
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• 2005

The aim of this study was to assess dietary fiber intake and the relationship between dietary fiber intake and nutrient intakes of elementary school students. Food consumption of 200 elementary school students (100 boys, 100 girls) in the 6th grade in Gimhae was assessed by 2-day estimated food records. Nutrient intakes were calculated using CAN-pro and total dietary fiber (TDF) intake using the TDF tables of the common Korean foods. The mean height and weight of the boys were 147.7 cm and 42.1 kg. The mean height and weight of the girls were 149.1 cm and 41.1 kg. The mean body mass index (BMI) of the boys (19.3 $kg/m^2$) was significantly higher than that of the girls (18.4 $kg/m^2$, p < 0.05). Average daily intake of energy of the boys and girls was 1733 and 1778 kcal, respectively. Intakes of protein, P, and niacin of the boys and girls exceeded $110\%$ of current RDA. Intakes of Fe, vitamin $B_1$ and vitamin $B_2$ of the boys were similar to RDA. Intake of vitamin $B_1$ exceeded $110\%$ of current RDA and intakes of Fe and vitamin A were similar to RDA among the girls. Ca intake of the boys and girls was $74.2\%$ and $60.1\%$ of RDA, respectively. Vitamin C intake of the boys and girls were $63.6\%$ and $71.7\%$ of RDA, respectively. Intakes of fat, Ca, P, and vitamin $B_2$ of the boys were significantly higher than the girls. Intakes of Fe and vitamin A of the boys were significantly lower than the girls. Average daily intakes of TDF of the boys and girls were 11.2 g and 11.1 g, respectively. TDF intake of the children at the 6th grade of elementary school was about $70\%$ of 'age (yr) + 5 g', a recommended level for American children. Major food groups to supply dietary fiber were vegetables, grains, and seasonings among the boys and girls. Major sources of dietary fiber were Kimchi, rice, and red pepper powder which supplied $17.85\%$. $15.71\%$, and $5.18\%$ of TDF among the boys and $18.02\%$, $16.22\%$, and $6.58\%$ among the girls. Daily fiber intake showed significant positive correlations with intakes of grains, vegetables, fruits, legumes, and seasonings among the boys and girls. Daily fiber intake showed significant positive correlations with intakes of energy, carbohydrates, protein, lipids, Ca, P, vitamin A, vitamin $B_1$ vitamin $B_2$, niacin, and vitamin C among both the boys and girls. From the results of this study we could conclude that it is recommended to increase dietary fiber intake in elementary school students at upper level.

• Toxicological Research
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• v.34 no.3
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• pp.221-229
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• 2018

Tenofovir nanoparticles are novel therapeutic intervention in human immunodeficiency virus (HIV) infection reaching the virus in their sanctuary sites. However, there has been no systemic toxicity testing of this formulation despite global concerns on the safety of nano drugs. Therefore, this study was designed to investigate the toxicity of Tenofovir nanoparticle (NTDF) on the liver and kidney using an animal model. Fifteen adult male Sprague-Dawley (SD) rats maintained at the animal house of the biomedical resources unit of the University of KwaZulu-Natal were weighed and divided into three groups. Control animals (A) were administered with normal saline (NS). The therapeutic doses of Tenofovir (TDF) and nanoparticles of Tenofovir (NTDF) were administered to group B and C and observed for signs of stress for four weeks after which animals were weighed and sacrificed. Liver and kidney were removed and fixed in formal saline, processed and stained using H/E, PAS and MT stains for light microscopy. Serum was obtained for renal function test (RFT) and liver function test (LFT). Cellular measurements and capturing were done using ImageJ and Leica software 2.0. Data were analysed using graph pad 6, p values < 0.05 were significant. We observed no signs of behavioural toxicity and no mortality during this study, however, in the kidneys, we reported mild morphological perturbations widening of Bowman's space, and vacuolations in glomerulus and tubules of TDF and NTDF animals. Also, there was a significant elevation of glycogen deposition in NTDF and TDF animals when compared with control. In the liver, there were mild histological changes with widening of sinusoidal spaces, vacuolations in hepatocytes and elevation of glycogen deposition in TDF and NTDF administered animals. In addition to this, there were no significant differences in stereological measurements and cell count, LFT, RFT, weight changes and organo-somatic index between treatment groups and control. In conclusion, NTDF and TDF in therapeutic doses can lead to mild hepatic and renal histological damage. Further studies are needed to understand the precise genetic mechanism.

• ETRI Journal
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• v.26 no.6
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• pp.545-554
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• 2004

In this paper, we propose an efficient design method for area optimization in a digital filter. The conventional methods to reduce the number of adders in a filter have the problem of a long critical path delay caused by the deep logic depth of the filter due to adder sharing. Furthermore, there is such a disadvantage that they use the transposed direct form (TDF) filter which needs more registers than those of the direct form (DF) filter. In this paper, we present a hybrid structure of a TDF and DF based on the flattened coefficients method so that it can reduce the number of flip-flops and full-adders without additional critical path delay. We also propose a resource sharing method and sharing-pattern searching algorithm to reduce the number of adders without deepening the logic depth. Simulation results show that the proposed structure can save the number of adders and registers by 22 and 26%, respectively, compared to the best one used in the past.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.355-359
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• 1993

This paper deals with the problem of robust TDF(Two Degree of Freedom) H$_{\infty}$ control design for a linear system with parameter uncertainty in the state space model. The uncertain system considered here is with the time-invariant norm-bounded parameter uncertainty in the state matrix. A TDF H$_{\infty}$ control design is presented which robustly stabilizes the plant, guarantees the robust H$_{\infty}$ performance and improves the tracking performance for the closed-loop system in the face of parameter uncertainty. It is shwon that a suitable stabilizing control law can be constructed in terms of a positive definite solution to a certain parameter-dependent algebraic Riccati equation and a good tracking performance can be constructed in terms of suitable feedforward control law.aw.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1040-1043
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• 1996

The accuracy of the servo control in CNC system has a great influence on the duality of machine product. Tracking performance of the servo control is deteriorated mainly by the time delay of the servo system and the inertia of the work table or bed. Contouring errors occur in every interpolation steps by the effect of the tracking performance. In this paper, $H_{\infty}$ two-degree-of-freedom(TDF) controller is designed for improvement to improve the tracking performance. The designed controller is applied 3-axis machining center model and the cutting accuracy is simulated in case of corner cutting, circular and involute interpolation. Simulation results show that $H_{\infty}$ TDF controller designed in this paper has a good effect to improve tracking performance in CNC system.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.107-108
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• 2006

This paper presents the design of a night vision system for vessels. Both a hardware system and software modules for stabilization control are developed. In order to stabilize each control axis, the two-degree of freedom(TDF) PID controller is designed and its parameters are tuned using a real-coded genetic algorithm(RCGA). Simulation demonstrates the effectiveness of the proposed system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.391-395
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• 1996

This paper presents a robust force tracking control of a small-sized SMA gripper with two fingers using shape memory alloy(SMA) actuators. The mathematical governing equation of the proposed system is derived by Hamilton's principle and Lagrangian equation and then, the control system model is integrated with the first-order actuator dynamics. Uncertain system parameters such as time constant of the actuators are also included in the control model. A robust two degree of freedom(TDF) controller using H$_{\infty}$ control theory, which has inherent robustness to model uncertainties and external disturbances, is adopted to achieve end-point force tracking control of the two-finger gripper. Force tracking control performances for desired trajectories represented by sinusoidal and step functions are evaluated by undertaking both simulation and experimental works.

• Steel and Composite Structures
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• v.32 no.3
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• pp.313-323
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• 2019

Ratcheting boundary is firstly determined by experiment, elastic-plastic finite element analysis combined with C-TDF and linear matching method, which is compared with ASME/KTA and RCC-MR. Moreover, based on elastic modulus adjustment procedure, a novel method is proposed to predict the ratcheting boundary for a pressurized pipe subjected to constant internal pressure and cyclic bending loading. Comparison of ratcheting boundary of elbow pipe determined by the proposed method, elastic-plastic finite element analysis combined with C-TDF and linear matching method, which indicates that the predicted results of the proposed method are in well agreement with those of linear matching method.