• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.725-730
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• 1994

This study was conducted to investigate the effect of dietary zinc (Zn) and/or cadmium (Cd) on hepatic microsomal and cytosol enzyme activities. Male Spraque-Dawley rats (110$\pm$10g ) received zinc (0, 30 and 300 ppm/) and Cd-treated groups were administered oral intubation with Cd chloride (5.0mg/kg of body weight 0 at the same time once a week. The effect of Cd on the activity of hepatic cytochromep-450 , xanthine oxidase(X. O) and superoxide dismutase (SOd) was studied in rats. Cd oral intubation resulted in a decrease in cytochrome P-450 content and SOD activity whereas a significant increase in the X.O. activity was observed was observed . Intake of excessive Zn led to an increased activity of microsomal alcohol dehydrogenase (ADH) , whereas Zn deficiency group led to a decreased group. The mechanism by which Zn induces the decreasing of Cd toxicity in rats, seems to rely on the protection of the enzyme systems P-450, ADH, aldehyde dehydrogenase (ALDH) and X.O. in the liver, possibly by forming non-toxic Cd metallothionein. These results indicate that Zn and Cd regulation might occur via inhibitory protein component of the $H_2O$$_2$ -generator system.

• BMB Reports
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• v.48 no.12
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• pp.647-654
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• 2015

Energy homeostasis in our body system is maintained by balancing the intake and expenditure of energy. Excessive accumulation of fat by disrupting the balance system causes overweight and obesity, which are increasingly becoming global health concerns. Understanding the pathogenesis of obesity focused on studying the genes related to familial types of obesity. Recently, a rare human genetic disorder, ciliopathy, links the role for genes regulating structure and function of a cellular organelle, the primary cilium, to metabolic disorder, obesity and type II diabetes. Primary cilia are microtubule based hair-like membranous structures, lacking motility and functions such as sensing the environmental cues, and transducing extracellular signals within the cells. Interestingly, the subclass of ciliopathies, such as Bardet-Biedle and Alström syndrome, manifest obesity and type II diabetes in human and mouse model systems. Moreover, studies on genetic mouse model system indicate that more ciliary genes affect energy homeostasis through multiple regulatory steps such as central and peripheral actions of leptin and insulin. In this review, we discuss the latest findings in primary cilia and metabolic disorders, and propose the possible interaction between primary cilia and the leptin and insulin signal pathways which might enhance our understanding of the unambiguous link of a cell's antenna to obesity and type II diabetes.

• BMB Reports
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• v.42 no.4
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• pp.217-222
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• 2009

Controlled gene expression in specific cells is a valuable tool for gene therapy. We attempted to determine whether the lentivirus-mediated Tet-On inducible system could be applied to cancer gene therapy. In order to select the genes that induce cancer cell death, we compared the ability of the known pro-apoptotreic genes, Bax and tBid, and a cell cycle inhibitor, p21cip1/waf1, and determined that Bax was the most effective. For the cancer cell-specific expression of $rtTA2^S$-M2, we tested the matrix metalloproteinase-2 (MMP-2) promoter and determined that it is highly expressed in cancer cell lines, including SNU475 cells. The co-transduction of two lentiviruses that contain sequences for TRE-Bax and $rtTA2^S$-M2, the expression of which is controlled by the MMP-2 promoter, resulted in the specific cell death of SNU475, whereas other cells with low MMP-2 expression did not evidence significant cell death. Our data indicate that the lentivirus-mediated Tet-On system using the cancer-specific promoter is applicable for cancer gene therapy.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.1 s.94
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• pp.72-80
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• 2005

Recent studies have dealt with brake squeal in terms of the coupled vibration of brake component parts. In this paper, we assemble the mode models derived from FE analysis of the individual components of the drum brake system into the system model by considering the friction interaction of the lining and drum at the interface. The validity of the component models are backed up by the experimental confirmation work. By scrutinizing the real parts of the complex eigen-values of the system, the unstable modes, which may be strong candidate sources of squeal noise, are identified. Mode participation factors are calculated to examine the modal coupling mechanism. The model predictions for the unstable frequencies pointed well the actual squeal noise frequencies measured through field test. Sensitivity analysis is also performed to identify parametric dependency trend of the unstable modes, which would indicate the direction for the squeal noise reduction design. Finally, reduction of the squeal noise tendency through shape modification is tried.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.661-668
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• 2007

In this paper, excitation systems using linear mass shaker (LMS) are presented in order to simulate the wind induced responses of a building structure. The actuator force for the excitation systems is calculated by using the inverse transfer function of a target structural response to the actuator. Filter and envelop function are used such that the error between the wind and actuator induced responses is minimized by preventing the actuator from exciting unexpected modal response and initial transient response. The analyses results from a 76-story benchmark building problem in which wind load obtained by wind tunnel test is given, indicate that the excitation system installed at a specific floor can approximately embody the structural responses induced by the wind load applied to each floor of the structure. The excitation system designed by the proposed method can be effectively used for evaluating the wind response characteristics of a practical building structure and for obtaining an accurate analytical model of the building under wind load.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.210-215
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• 2007

In this paper, excitation systems using an active tuned mass damper (ATMD) are presented in order to simulate the wind induced responses of a building structure. The actuator force for the excitation systems is calculated by using the inverse transfer function of a target structural response to the actuator. The analyses results from a 76-story benchmark building problem in which wind load obtained by wind tunnel test is given, indicate that the excitation system installed at a specific floor can approximately embody the structural responses induced by the wind load applied to each floor of the structure. The excitation system designed by the proposed method can be effectively used for evaluating the wind response characteristics of a practical building structure and for obtaining an accurate analytical model of the building under wind load.

• Journal of Korean Society on Water Environment
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• v.24 no.2
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• pp.180-184
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• 2008

A distributed hydrologic model of an urban drainage area on Bugok drainage area in Oncheon stream was developed and combined with a optimization method to determine the optimal location and number of best management practices (BMPs) for storm water runoff reduction. This model is based on the SCS-CN method and integrated with a distributed hydrologic network model of the drainage area using system of 4,211 hydrologic response units (HRUs). Optimal location is found by locating HRU combination that leads to a maximum reduction in peak flow at the drainage outlet in this model. The results of this study indicate the optimal locations and numbers of BMPs, however, for more exact application of this model, project cost and SCS-CN reduction rate of structural facilities such infiltration trench and pervious pavement will have to be considered.

• Korean Journal of Medicinal Crop Science
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• v.14 no.6
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• pp.329-335
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• 2006

The present study was designed to investigate aging-related effects on the activities of xenobiotic metabolizing enzymes of rat liver by dietary supplementation of Korean red ginseng water-extract. Rat did not show any discernible signs of the rejection symptoms, and blood GOT and GPT levels were not influenced by ginseng water extracts, Cytochrome 450 levels and NADPH cytochrome P45O reductase, p-450 dependent ethoxycoumarin O-deethylase, and benzphetamine N-demethylase activities were decreased with aging, however, these phase I system enzymes activities in the ginseng group of24 months were well maintained compared with normal group. But, Levels of cytochrome bs and NADH-cytochrome b$_5$ reductase activities were also decreased with aging and were not found a clear difference between two groups. Glutathione-s-transferase activity, phase II enzyme system, in liver cytosols was also decreased in old ages, but the degree of decrease was higher in normal group than in giuseng supplemented group. These results indicate that long-term supplementation of red ginseng water extracts from weaning to 24 months do not show any side effects to rats, and retard age-related deteriorations of xenobiotic metabolizing enzymes activities in old ages.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.361-364
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• 2005

The use of remotely sensed data and geographic information system (GIS) to develop conservation-oriented watershed management strategies on Imha Dam, Korea, is presented. The change of land use for study area was analyzed using multi-temporal Landsat imagery. A soil loss model was executed within a GIS environment to evaluate watershed management strategies in terms of soil loss. In general, remotely sensed data provide efficient means of generating the input data required for the soil loss model. Also, GIS allowed for easy assessment of the relative erosion hazard over the watershed under the different land use change options. The soil loss model predicted substantial declines in soil loss under conservation-oriented land management compared to current land management for Imha Dam. The results of this study indicate that soil loss potential (5,782,829 ton/yr) on Imha Dam in 2003 is approximately 1.27 times higher than that (4,557,151 ton/yr) in 1989. This study represents the first attempt in the application of GIS technology to watershed conservation planning for Imha Dam. The procedures developed will contribute to the evolution of a decision support system to guide the land planning and dam management in Imha Dam.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.93-94
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• 2011

This paper analyzes the shaft torsion of a doubly-fed induction generator (DFIG) for a wind farm collector system fault. When a fault occurs, the active power of the DFIG cannot be transmitted to the grid and thus accelerates the rotation of both the blade and the rotor. Due to the different inertia of these, the angle of deviation fluctuates and the shaft torsion is occurred. This becomes much severe when the rotational speed of the blade exceeds a threshold, which activating the pitch control to reduce the mechanical power. The torque, which can be sixty times larger than that in the steady state, may destroy the shaft. The shaft torsion phenomena are simulated using the EMTP-RV simulator. The results indicate that when a wind farm collector system fault occurs, a severe shaft torsion is occurred due to the activation of the pitch control.