• Korean Journal of Biological Psychiatry
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• v.7 no.1
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• pp.46-54
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• 2000

Traumatic brain injury(TBI) is generally considered to be a risk factor for psychiatric disorders, especially depression and anxiety disorder. Despite the anxiety disorders are frequent sequelae after traumatic brain injury, the patients have not been payed medical attention and treated by doctors properly. The factors of precipitating and sustaining the anxiety disorders after TBI are brain injury itself, and the patient's or caregiver's response to the disability after TBI. To diagnose and treat them effectively, the knowledge about the mechanisms of and symptoms after TBI have to be needed. Psychiatrist should be a supportive and good listener to the patients who are complaining anxiety symptoms and differentiate whether the psychiatric symptoms are due to TBI or not. Because the TBI patients are very sensitive to drug side effects, doctors have to be familiar with the side effects as well as the mechanisms of action of the common psychotropics.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.2
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• pp.140-148
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• 2000

A robust current control technique with a simple time delayed estimator for a permanent magnet synchronous m motor (PMSM) drive is presented. Among the various CWTent control schemes for a voltage source inverter-fed P PMSM drive, the predictive control is known to give a superior performance. This control technique, however, r requires the full knowledge of machine parameters and operating conditions, and gives an unsatisfactory r response under the parameter mismatch between the motor and controller. To overcome such a limitation, the d disturbances caused by the parameter valiations will be estimated by using a" time delay contTol approach and u used for the computation of the reference voltages by a simple feedforwal"d control. The proposed control $ scheme is implemented on a PMSM using the software of DSP TlVIS:32OC:30 and the effectiveness is verified d through the comparative simulations and experiments.periments.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.4
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• pp.335-342
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• 2000

A new control method for a single-phase active power filter, based on a load current estimation using a DC capacitor voltage of active power filter without sensing nonlinear load current, is proposed in this paper. Because the method proposed can remove the load current sensor in comparison with a conventional method sensing the load current and DC capacitor voltage together, it can make the active power filter easy installation, low cost, small size with no performance detriment. In addition, sample-hold technique and proportional control method is adopted to control the DC capacitor voltage and as no delay element such as LPF or PI control in the conventional method is used, the transient response is fast and good. Operation of a single-phase active power filter which consist of eight mode is explained according to utility voltage, compensation current and switch state, and compensation characteristics of active power filter using proposed method is verified by experiment.

• Restorative Dentistry and Endodontics
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• v.25 no.4
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• pp.606-618
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• 2000

Dental pulp infection is most commonly caused by extensive dental caries, and some bacterial species invade root canals; bacterial components and products are thought to be associated with the pathogenesis of periapical periodontitis. A principle driving force behind pulpal disease response appears to lie in the host immune system's to bacteria and their products. We examined the production of interleukin $1{\beta}$ (IL-$1{\beta}$) and tumor necrosis factor ${\alpha}$(TNF-${\alpha}$) from human peripheral mononuclear cells, lymphocytes and monocytes stimulated by heat-killed Acitnobacillus actinomycetemcomitans (ATCC 29523), Porphyromonas gingivalis (ATCC 33277) and Prevotella intermedia (ATCC 25611), and also by their sonicated bacterial extracts (SBE), respectively. The effects of three strains of heat-killed bacteria and their SBEs on the morphology of cultured blood cell lines HL-60 (KCLB 10240) and J774A.1 (KCLB 40067) were observed under the inverted microscope. Ultrastructural changes of J774A.1 exposed to heat-killed P. intermedia and its SBE were investigated using transmission electron microscopy. Production of IL-$1{\beta}$ was reduced in human peripheral mononuclear cells after stimulation by sonic bacterial extracts of A. actinomycetemcomitans, P. gingivalis, and P. intermedia. Heat-killed and sonic extract of P. gingivalis inhibited the production of TNF-${\alpha}$ in peripheral mononuclear cells. Production of TNF-${\alpha}$ was inhibited in peripheral monocytes after stimulation by sonic extracts of A. actinomycetemcomitans, P. gingivalis, and P. intermedia. HL-60 and J 774A.1 cells showed granular degeneration after treatment with heat-killed and sonic extracts of A. actinomycetemcomitans, P. gingivalis, and P. intermedia Chromatin margination and shrinkage were observed in 774A.1 treated with heat-killed P. intermedia. Cell wall structure and organelles were destroyed and vacuoles were formed in cytoplasm in J774A.1 treated with P. intermedia sonic extract. These results suggest that A actinomycetemcomitans, P gingivalis and P intermedia may have an important role in the formation and progression of pulpal diseases via both modulation of production of IL-$1{\beta}$ and TNF-${\alpha}$ from blood mononuclear cells and cytopathic effects.

• The Transactions of the Korea Information Processing Society
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• v.7 no.5
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• pp.1370-1376
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• 2000

Consider the problem to updata breadth-First Spanning Tree in response to topology change of the network. The paper proposes an efficient distributed algorithm that solves such a problem after several processors and links are added and deleted. Its message complexity and its ideal-time complexity are O(p√q+q+a+n') respectively, where n' is the number fo processors in the network after the topology change, a is the number of added links, p is the total number of links in the biconnected component (of the network before the topology change) including the detected links or added links, and q is the total number of processors in the biconnected component (of the network before the topology change) including the deleted links or added links, and q is the total number of processors in the biconnected component including the deleted links or added links.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.647-654
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• 2000

Response surface methodology (RSM) was used for monitoring the changes in browning reaction and organoleptic quality of roasted Polygonatum roots under various of roasting conditions. Total free sugar decreased up to 13$0^{\circ}C$, but increased above 13 $0^{\circ}C$. The amounts of total free amino acids decreased in proportional to the roasting temperature and time. Theronine, glycine and serine decreased by about 91~94% under the roasting conditions. Browning color intensity of water extracts increased with the roasting time up to around 18 min, but decreased over 18 min. The optimum conditions based on overall palatability of the roasted Polygonatum roots were 13$0^{\circ}C$ and 15 to 25 min. Organoleptic qualities of the roasted samples showed higher correlations with the changes in free amino acids.

• Journal of Periodontal and Implant Science
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• v.30 no.2
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• pp.229-242
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• 2000

The purpose of this study was to evaluate the effect of fibrin tissue adhesive and porous resorbable calcium carbonate on the periodontal regeneration of the class II furcation defect in dogs. Class II furcation defect was surgically created on the second, third, and fourth premolars bilaterally in the mandibles of six mongrel dogs. The experimental sites were divided into four groups according to the treatment modalities: Control-surgical debridement only; Group I-calcium carbonate grafting; Group II-application of fibrin adhesive only; Group III-application of fibrin adhesive after calcium carbonate grafting. The animals were sacrificed at the 2, 4, and 12 weeks after periodontal surgery and the decalcified specimens were prepared for histological and histometrical examination. The results are as follows : Clinically, there were no inflammatory response in all groups after 2, 4, 12 weeks. In the Control group, junctional epithelium was grown downward to the reference notch. In Group I, graft materials were exfoliated from the defect throughout the experimenta periods andnew bone was seen in the notch area at 4 and 12 week specimens. In Group II, fibrin adhesive was absorbed at 2 week specimens, and connective tissue attachment increased than that of control group. New cementum and new bone were seen above the notch area. In Group III, the graft material was maintained in the defect throughout the experimental period and inducing the amount of periodontal tissue regeneration was higher than other groups. These results suggest that the use of fibrin tissue adhesive in conjunction with porous resorbable calcium carbonate would improves the stability of graft material and inhibit the epithelial down growth and make it be a feasible method for periodontal regeneration.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.480-480
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• 2000

In this paper, we proposed a fuzzy-neuro controller to control the speed of wound rotor induction motor with slip energy recovery. The speed is limited at some range of sub-synchronous speed of the rotating magnetic field. Control speed by adjusting resistance value in the rotor circuit that occurs the efficiency of power are reduced, because of the slip energy is lost when it passes through the rotor resistance. The control system is designed to maintain efficiency of motor. Recently, the emergence of artificial neural networks has made it conductive to integrate fuzzy controllers and neural models for the development of fuzzy control systems, Fuzzy-neuro controller has been designed by integrating two neural network models with a basic fuzzy logic controller. Using the back propagation algorithm, the first neural network is trained as a plant emulator and the second neural network is used as a compensator for the basic fuzzy controller to improve its performance on-line. The function of the neural network plant emulator is to provide the correct error signal at the output of the neural fuzzy compensator without the need for any mathematical modeling of the plant. The difficulty of fine-tuning the scale factors and formulating the correct control rules in a basic fuzzy controller may be reduced using the proposed scheme. The scheme is applied to the control speed of a wound rotor induction motor process. The control system is designed to maintain efficiency of motor and compensate power factor of system. That is: the proposed controller gives the controlled system by keeping the speed constant and the good transient response without overshoot can be obtained.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.395-395
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• 2000

Optimization of existing processes becomes more important than the past as environmental problems and concerns about energy savings stand out. When we can model a process mathematically, we can easily optimize it by using the model as constraints. However, modeling is very difficult for most chemical processes as they include numerous units together with their correlation and we can hardly obtain parameters. Therefore, optimization that is based on the process models is, in turn, hard to perform. Especially, f3r unknown processes, such as bioprocess or microelectronics materials process, optimization using mathematical model (first principle model) is nearly impossible, as we cannot understand the inside mechanism. Consequently, we propose a few optimization method using empirical model evolutionarily instead of mathematical model. In this method, firstly, designing experiments is executed fur removing unecessary experiments. D-optimal DOE is the most developed one among DOEs. It calculates design points so as to minimize the parameters variances of empirical model. Experiments must be performed in order to see the causation between input variables and output variables as only correlation structure can be detected in historical data. And then, using data generated by experiments, empirical model, i.e. response surface is built by PLS or MLR. Now, as process model is constructed, it is used as objective function for optimization. As the optimum point is a local one. above procedures are repeated while moving to a new experiment region fur finding the global optimum point. As a result of application to the pulp digester benchmark model, kappa number that is an indication fur impurity contents decreased to very low value, 3.0394 from 29.7091. From the result, we can see that the proposed methodology has sufficient good performance fur optimization, and is also applicable to real processes.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.6
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• pp.507-513
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• 2000

ErbB3/HER3 is a cell surface receptor which belongs to the ErbB/HER subfamily of receptor protein tyrosine kinases. When expressed in NIH/3T3 cells, ErbB3 can form heterodimeric coreceptor with endogenous ErbB2. Among known intracellular effectors of the ErbB2/ErbB3 are mitogen-activated protein kinase (MAPK) and phosphoinositide (PI) 3-kinase. In the present study, we studied relative contributions of above two distinct signaling pathways to the heregulin-induced mitogenic response via activated ErbB3. For this, clonal NIH-3T3 cell lines expressing wild-type ErbB3 and ErbB3 mutants were stimulated with $heregulin{\beta}_1$. While cyclin D1 level was markedly high and further increased by treatment of heregulin in cells expressing wild-type ErbB3, the elimination of either Shc binding or PI 3-kinase binding lowered both levels. This result was supported by the reduction of cyclin $D_1$ expression by preteatment with MAPK kinase inhibitor or PI 3-kinase inhibitor before stimulation with heregulin. In accordance with the cyclin $D_1$ expression, elimination of either Shc binding or PI 3-kinase binding reduced the heregulin-induced DNA synthesis and cell growth rate. Our results obtained by the comparison of wild-type and ErbB3 mutants indicate that the full induction of the cell cycle progression through $G_1/S$ phase by ErbB3 activation is dependent on both Shc/MAPK and PI 3-kinase signal transduction pathways.