• Journal of Korean Neurosurgical Society
• /
• v.50 no.4
• /
• pp.327-331
• /
• 2011

Objective : The aim of this study is to investigate the clinical outcomes of surgery and coiling and analyze the predicting factors affecting the clinical outcomes of ruptured posterior inferior cerebellar artery (PICA) aneurysms. Methods : During the last 15 years, 20 consecutive patients with ruptured PICA aneurysms were treated and these patients were included in this study. The Fisher's exact test was used for the statistical significance of Glasgow Outcome Scale (GOS) according to initial Hunt-Hess (H-H) grade, treatment modalities, and the presence of acute hydrocephalus. Results : Eleven (55%) and nine (45%) patients were treated with surgical clipping and endovascular treatment, respectively. Among 20 patients, thirteen (65.0%) patients had good outcomes (GOS 4 or 5). There was the statistical significance between initial poor H-H grade, the presence of acute hydrocephalus and poor GOS. Conclusion : In our study, we suggest that initial H-H grade and the presence of acute hydrocephalus may affect the clinical outcome rather than treatment modalities in the ruptured PICA aneurysms.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.61-64
• /
• 1996

This paper presents a new approach to the design of self-tuning adaptive control system that is robust to the changing dynamic configuration as well as to the load variation factors using Digital signal processors for robot manipulators. TMS32OC50 is used in implementing real-time adaptive control algorithms to provide advanced performance for robot manipulator. In this paper, an adaptive control scheme is proposed in order to design the pole-placement self-tuning controller which can reject the offset due to any load disturbance without a detailed description of robot dynamics. Parameters of discrete-time difference model are estimated by the recursive least-square identification algorithm, and controller parameters are determined by the pole-placement method. Performance of self-tuning adaptive controller is illustrated by the simulation and experiment for a SCARA robot.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.2407-2409
• /
• 2005

As the cumulative amount of spent fuel increases, the reliable and effective management of the spent fuel has become a world-wide mission. For this mission, KAERI is developing the Advanced Spent Fuel Conditioning Process (ACP) as a pre-disposal treatment process for spent fuel. Conventional approach to the development of the process and the remote operation technology is to fabricate the process equipment on the same scale as the real environment and demonstrate the remote handling operation using simulated fuel called a mock-up test. But this mock-up test is expensive and time consuming, since the design may need to be modified and the equipment fabricated again to account for the problems found during a testing. To deal with this problem, we developed a digital mockup for the ACP. Also, for an effective utilization of the digital mockup, we developed user interface modules such as the data acquisition and display module and the external input device interface module. The result of this implementation shows that a continuous motion of the manipulator using the external device interface can be represented easily and the information display screens responded well to the simulation situation.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.2368-2372
• /
• 2005

We proposed a novel method for object recognition using the Smart tag system in the previous research. We identified the object easily, but could not assure the object pose, because the threshold problem was not solved. So we propose a new method to solve this threshold problem. This method uses a smart tag to decide the threshold by recording color information of the image when the object feature is extracted. This method records the original of the object color information at the smart tag first. And then it records the object image information, the circumstance image information and the sensors information continuously when the object feature is extracted through the experiments. Finally, it estimates the current threshold by recorded information. This method can be applied the threshold to each objects. And it can solve the difficult threshold decision problem easily. To approve the possibility of our method, we implemented our approach by using easy and simple techniques as possible.

• Journal of Soil and Groundwater Environment
• /
• v.16 no.2
• /
• pp.1-5
• /
• 2011

We surveyed the citizens opinion about springs in Seoul for two years from 2008 to 2009. It was found that spring water was mostly used by citizens older than 50, and that 29.5% of citizens used purified tap water as drinking water, 27.2% of them used boiled tap water, 21.1% of them used spring water, and 12.1% of them used bottled water. Citizens who store spring water more than a day are 76.7%. Although many citizens (70.3%) knew that water quality had been tested, 40% of them didn't care about checking the certificate of water quality analysis. Once recognized that the spring water was unfit for drinking exceeded standard of drinking water, 85% of citizens would rather not use the spring water.

• Journal of Environmental Science International
• /
• v.18 no.2
• /
• pp.215-219
• /
• 2009

Micropollutants, which can be caused by imperfect combustion, are toxic chemical compound that flows into the river system after being contained in road runoff, a non-point source pollutant and accumulates in the body. The micropollutants that have characteristics such as toxicity, persistence, bio-accumulation, long-range transportation behave so similarly to micro particles that they can be removed by means of filtration or absorption. This study has examined the kinds and concentrations of micropollutants contained in deposited road particles. It has revealed that the kinds of micropollutants contained in the clarified supernatant liquid of deposited road particles are heavy metals and polycyclic aromatic hydrocarbons(PAHs) composed of two or three benzene rings, including naphthalene and acenaphthalene. Their concentrations have been shown to be low, with 0.418 mg/L, 0.058 mg/L, 0.104 mg/L, 0.014 mg/L, 0.00075 mg/L for Zn, Pb, Cu, Cr, Cd, respectively and 0.00156 mg/L and 0.00184 mg/L for naphthalene and acenaphthalene.

• Journal of Electrochemical Science and Technology
• /
• v.2 no.2
• /
• pp.85-90
• /
• 2011

Active oxygen species or free radicals are considered to cause extensive oxidative damage to biological macromolecules, which brings about a variety of diseases as well as aging. Electrolyzed reduced water(ERW) has been regarded as a ideal antioxidative agent in recent years. ERW is produced by passing a diluted salt solution through an electrolytic cell, within which the anode and cathode are separated by membrane. It can be produced reactive materials in ERW near the cathode during the electrolysis of water. ERW have the following advantages over other traditional cleaning agents: effective antioxidative agent, easy preparation, inexpensive, and environmentally friendly. The main advantage of ERW is its safety and antioxidative effect. ERW with strong reducing potential can be used to remove dirt and grease from items such as cutting boards and other kitchen utensils. The primary aim of this study is the activation mechanism of oxidation reduction potentials, ion conductivity, pH, and electrochemical properties with reactive materials in ERW.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.11a
• /
• pp.41-44
• /
• 2004

양성자 주입 기술을 pn 다이오드의 동작 속도를 향상시키기 위한 방법 이용하였다. 양성자 주입은 에너지를 2.32 MeV, 2.55 MeV, 2.97 MeV로 변화시키며 수행하여, projection 범위를 각각 접합, 공핍, 중성영역에 위치하도록 하였다. 또한 각각의 에너지 조건에서 도즈를 $1{\times}10^{11}\;cm^{-2}\;1{\times}10^{12}\;cm^{-2},\;1{\times}10^{13}\;cm^{-2}$의 세가지 조건으로 변화시켰다. 양성자 주입 조건 변화에 따른 소자 동작특성의 변화를 관찰하기 위하여 소자의 전류-전압 특성, 용량-전압 특성, 역방향 회복시간 측정을 수행하였다. 분석결과 양성자를 주입하지 않은 소자에 비해 특성의 큰 열화없이 역방향 회복시간을 약 1/5 수준으로 단축시킬 수 있는 것으로 나타났다.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.48 no.12
• /
• pp.791-797
• /
• 1999

Recently the ozone generation system is well used for cleaning the contaminated water by using the strong oxidization effects of ozone. In this paper the concentration, yield and generation quantity of the ozone by the Surface-Silent Discharge According to the Length of Coaxial Electrode is described. The electrodes composed of 3 electrodes-2 gaps are coaxial type and the ozone generation tube were designed and fabricated from the point of view of the energy efficiency, stability and easy control. To investigate the ozone generation dependency on electrode length, a few discharge tubes with different lengths were fabricated. The experimental equipments were provided with cooling system and dehumidifier for the many testing conditions. The main results show that the concentration, yield and generation quantity of ozone are improved by decreasing gas temperatures and increasing electrode lengths.

• KIEE International Transactions on Power Engineering
• /
• v.3A no.4
• /
• pp.181-190
• /
• 2003

This paper presents the design of a fuzzy power system stabilizer (FPSS) using an adaptive evolutionary algorithm (AEA). AEA consists of genetic algorithm (GA) for a global search capability and evolution strategy (ES) for a local search in an adaptive manner when the present generation evolves into the next generation. AEA is used to optimize the membership functions and scaling factors of the FPSS. To evaluate the usefulness of the FPSS, we applied it to a single-machine infinite bus system (SIBS) and a power system simulator at the Korea Electrotechnology Research Institute. The FPSS displays better control performance than the conventional power system stabilizer (CPSS) for a three-phase fault in heavy load, which is used when tuning FPSS. To show the robustness of the FPSS, it is applied with disturbances such as change of mechanical torque and three-phase fault in nominal and heavy load, etc. The FPSS also demonstrates better robustness than the CPSS. Experimental results indicate that the FPSS has good system damping under various disturbances such as one-line to ground faults, line parameter changes, transformer tap changes, etc.