• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.2
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• pp.142-149
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• 2013

The thrust vector control technique is essential for high maneuverability of unmanned aerial vehicles. In the present study, a multi-component balance was developed to quantitatively evaluate the thrust-vectoring performance of a supersonic rectangular nozzle based on the Coanda coflowing effect. Precise calibration and detailed data analysis were performed during the development. It was found that the cross-talk errors between load cells in the balance were less than 5%, and that the unwanted errors due to high-pressure supply tubes were almost negligible, which contributed to the high accuracy of the present balance design. Some preliminary test results of the thrust-vectoring performance of the present nozzle design were also obtained and analyzed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.1
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• pp.37-46
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• 2017

Thermal Marangoni flow has been observed inside droplets on heated surfaces, finally resulting in a coffee stain effect. This study aims to visualize and control the thermal Marangoni flow by employing periodic vertical vibration. The variations in the contact angle and internal volume of the droplet as it evaporates is observed by using a combination of continuous light and a still camera. With regard to the internal velocity, the particle image velocimetry system is applied to visualize the internal thermal Marangoni flow. In order to estimate the internal temperature gradient and surface tension on the surface of a droplet, the theoretical model based on the conduction and convection theory of heat transfer is applied. Thus, the internal velocity increases with an increase in plate temperature. The flow directions of the Marangoni and gravitational flows are opposite, and hence, it may be possible to control the coffee stain effect.

• Journal of the Korean Society of Propulsion Engineers
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• v.1 no.2
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• pp.32-40
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• 1997

The velocity and turbulent intensity of the jet core are affected by the vortices around jet. By the control of vortex acoustically, we can expect the changes of the flow and heat transfer characteristics of free and impinging jets. On this paper, we studied the effects of vortex forcing. If vortex pairings are promoted by acoustic excitation, the turbulent intensity is increased and the high heat transfer coefficients are obtained at the small nozzle to plate distance. On the other hand, it has low turbulent intensity at the center of jet. However due to increase of potential core length, it is more effective at the large nozzle to plate distance. Therefore the excited frequency, especially its subharmonic frequency, has an important role to control the jet flows.

• Journal of Intelligence and Information Systems
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• v.14 no.4
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• pp.89-101
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• 2008

The most used tool for quality control is control chart in manufacturing industry. But it has limitations at current situation where most of manufacturing facilities are automated and several manufacturing processes have interdependent relationship such as CCM assembly line. To Solve problems, we propose quality management system based on data mining that are consisted of monitoring system where it monitors flows of processes at single window and feature extraction system where it predicts the yield of final product and identifies which processes have impact on the quality of final product. The quality management system uses decision tree, neural network, self-organizing map for data mining. We hope that the proposed system can help manufacturing process to produce stable quality of products and provides engineers useful information such as the predicted yield for current status, identification of causal processes for lots of abnormality.

• Journal of Korean Society of Forest Science
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• v.94 no.4 s.161
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• pp.252-257
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• 2005

The study on long-term change of natural and sediment disasters such as landslides and debris flows is not thoroughgoing enough in spite of increasing of concern for disaster. Therefore, the change of natural and sediment disasters was investigated with the number of victims caused by both disasters and the ratio of sediment disasters for natural disasters was compared. The number of victims by sediment and natural disasters has apparently been decreasing despite of the change of rainfall pattern. The number of victims was changed to 140 persons/year in the late 1990s from 250 persons/year in the 1970s of natural disaster and that of sediment disaster to 20 persons/year in the late 1990s from 60 persons/year in the late 1970s. Furthermore, the ratio of sediment disaster victims to natural disaster victims has decreased from 2/7 in the 1970s to 2/15 after 1980s. But, the system of sediment disaster management and new soil erosion control works tough introduction of watershed management concept are requested because of increased landslide area in recent years (206ha in 1981 $\rightarrow$ 688ha in 1999).

• Korean Journal of Clinical Pharmacy
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• v.3 no.1
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• pp.31-43
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• 1993

The influence of phenobarbital(PB) pretreatment(75mg/kg/day, Lp. for 4 days) on the hepatic clearance of indocyanine green(ICG) as a model compound of organic anionic drugs was investigated in rats in order to elucidate the relative contributions of change in the hepatic blood flow versus increase in the hepatic intrinsic activity to remove ICG due to PB pretreatment. ICG(1mg/kg) was injected single bolus via femoral or portal vein to the control and the PB-pretreated rats. The initial hepatic uptake clearance$(V_{d.c.}K_{12})$ obtained from plasma concentration-time data was increased by $38.4\% in the PB-pretreated rats, which may be due to the increased hepatic blood flow by PB pretreatment. Using a pharmacokinetic approach, hepatic blood flows were estimated of 67.5ml/min/kg in control rats and 91.9ml/min/kg in PB-pretreated rats. They were in good agreement with other's blood flow estimates observed experimentally. It may be concluded that the $38\%$ increased initial hepatic uptake clearance of ICG was due to the $36\%$ increased hepatic blood flow with phenobarbital, and that the increased hepatic blood flow and the activated hepatic intrinsic clearance with phenobarbital contributed to $49\%\;and\;51\%$ of the increased systemic clearance of ICG, respectively.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.5
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• pp.590-597
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• 2016

We designed the multiple scattering points generation system to simulate an actual situation of target signal for high range resolution radar system. This provides replicating the target signals and controlling the status of target signals for radar system. This is composed transmit antenna and multi target generator. Transmit antenna is waveguide array antenna and multi target generator has signal distribution module and control & power module. Multi target generator is able to provide the high isolation and variable output power. Moreover, in order to monitor all output signals of the multi target generator, the flows of signals are programed in control & power module. The performance is demonstrated using experimented results of high range resolution radar.

• The KIPS Transactions:PartD
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• v.18D no.5
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• pp.343-356
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• 2011

When preparing test cases and running the test the existing GUI test tools require many tester's interventions. To cope with such problem this paper suggests a new method to build test cases for GUI test. This method identifies the potential control flows within the GUI and constructs the GUI map. The UIA library in .NET Framework is used to extract information about the GUI controls and the GUI map is constructed by the extracted information. Test scenarios are generated from the extracted information about the GUI controls using the grouping mechanism. Based on the grouping mechanism, various test scenarios which are test cases in GUI tests can be made by replacing a GUI control by another one in the same group. The existing GUI test tools do not support the concept of test coverage. Since, however, our method survey which part of the GUI map is executed or not during running the test, the test coverage can be measured by using the GUI map.

• The Korea Journal of Herbology
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• v.21 no.1
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• pp.1-7
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• 2006

Objectives: To find out the effects GGT1, an antiobestic drug widely used clinics, has on the amount of feed intake, the amount of change in the body weight and the food efficiency ratio using the data from the hGHTg obese male rats. Also, to evaluate in terms of antiobestic effects, the difference between GGT1 and reductil (sibutramine), which has been approved by the FDA of the United States. Methods: We measured the change in body weight and the amount of feed intake for 8 weeks by categorizing the hGHTg obese male rats into three groups: the control group, the GGT1 group, and the reductil (RD) group. We also evaluated the antiobestic effect by calculating the food efficiency ratio, which is the increase of bodyweight divided by the amount of feed intake. Results: In case of body weight, moderate slope of the curve in the graph of GGT1 group could mean that the weight is decreasing as time flows. In case of food efficiency ratio, the p-value was 0.745 in a test for determining if an interaction exists between the group and the point of measurement, meaning that it does not exist; also, the p-value in a test for the effect of level of repetition in food efficiency ratio according to the point of measurement equaled 0.002. Conclusion: The drug-treated groups had a greater inhibitory effect in feed intake than the control group. The results showed the food efficiency ratio had a tendency to decrease. The GGT1 group in particular was under a greater effect than the RD group.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.903-906
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• 2011

The electroplating and electro-less plating methods have been applied for the high density chip interconnect of the Copper Pillar Tin Bump (CPTB) preparation. The CPTB was prepared, which had been electroplated about $100{\mu}m$ pitch of copper layer firstly, and then the Tin layer was deposited on the copper pillar surface to protect the oxidation of it. It was also very important to get uniform thickness of electroplated copper layer, though it was difficult and sensitive. In order to control the thickness distribution, it was examined that the current separating disk of Insulating Gate with a hole in the center was installed between electrodes. The current flows through the center hole of the Insulating Gate in the cylindrical electroplating bath and the other parts were blocked to protect current flowing. The main current flowed through the center hole of the Insulating Gate directly to the opposite electrode of wafer disk. As the results, it was verified that the copper layer was thick in the center part of wafer disk with distribution of thinner to the outer part toward edge.