• Journal of IKEEE
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• v.15 no.2
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• pp.164-170
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• 2011

In this paper, we present a novel Lateral Insulated-Gate Bipolar Transistor(LIGBT) structure. The proposed structure has extra emitter between emitter and collector of the conventional structure. The added emitter can significantly improve latch-up current densities, forward voltage drop (Vce,sat) and turn-off characteristics. From the simulation results, the proposed LIGBT has the lower forward voltage drop(1.05V), the higher latch-up current densities($2.5{\times}10^3\;A/{\mu}m^2$), and the shorter turn-off time(7.4us) than those of the conventional LIGBT.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.35-36
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• 2006

In Nd:YAG laser welding, evaluation methods of welding flaw are various. But, the method due to fume shape is difficult to classification of welding flaw. The Nd:YAG laser process is known to have high speed and deep penetration capability to become one of the most advanced welding technologies. At the present time, some methods are studied for measurement of fume shape by using high-speed camera and photo diode. This paper describes the machining characteristics of SM45C carbon steel welding by use of an Nd:YAG laser. In spite of its good mechanical characteristics, SM45C carbon steel has a high carbon contents and suffers a limitation in the industrial application due to the poor welding properties. In this study, fume shape was measured by infrared thermal camera that is non-contact/non-destructive thermal measurement equipment through change of laser generating power, speed, focus. Weld was performed on bead-on method. Measurement results are compared as two equipments. Here, two results are composed of measurement results of fume quantities due to fume shape by infrared thermal camera and inspection results of weld bead include weld flaws by ultrasonic inspector.

• Magazine of the Korean Society of Agricultural Engineers
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• v.23 no.1
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• pp.86-102
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• 1981

The soil test data of 28 earth dams, scheduled to be constructed in Kore3, were selected for this study. The safety factors of their side slops were computed using Fellenius' "slice Method" by computer. The results summarized in this study are as follows; 1. Dam sections can be easily determined by fig.10 without a time consuming trial and error calculations of assumed sections. 2. For the economical design of earth dam sections, it was found that more cohesive soil was suitable for lower dams(dam height less than 25m) and soils with a higher friction angle was better for higher dams 3. In the case that used soil materials have the same Internal friction angle, side slope increase was almost same. 4. The relationship between side slope and friction angle was found as log.S=a tan ø+b (Fig. 7) 5. The relationship between side slope and cohesion (c) was also found as log. S=a c+b (Fig. 8) 6. The change of safety factors due to the change of central core materials was very little (Table-2) 7. The decrease of safety factors according to the unit weight increase of embankment materials was negligible. 8. In general the relationship between the wet unit weight and the saturated unit weight was r sat = (rt)$^2$+0. 140. This study will contribute to the determination of economic and safe planning and designing of earth dams, embankments and cutting side slopes.

• International Journal of Safety
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• v.10 no.2
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• pp.21-26
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• 2011

In 2001, an independent official board was constituted in Japan to investigate aircraft and railway accidents. In the past 10 years, many accidents and serious incidents have been investigated and these official reports were published by the board, on which the author had sat for 9 years as boarding member. In the interim, there were several train disasters which mocked our trust in railways and also many apparent trivial incidents. In recent years, serious incidents, which a door of running rail cars opens suddenly with some trouble, happen 2 or 3 times in a year. For the past 10 years, such incidents have happened 14 times and 13 cases of them were closed by the board mentioned above. In these 13 cases, no one fell off the rail car, so that the death toll was none luckily. In this paper, these 13 serious incidents are picked up among all the reports published by the board and outlined using some tables. Especially, fall accidents of passengers are discussed mainly from the view point of impact force and duration time. Then, the equation of HIC (Head Injury Criteria) and the risk curves in terms of the HIC are dealt with properly.

• Korean Journal of Veterinary Research
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• v.60 no.1
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• pp.15-18
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• 2020

Canine heartworm disease is a vector-borne disease that is transmitted from dog to dog by mosquitoes. It causes epidemics that disrupt the health environments of dogs and are burdensome for many dog owners. Recent trends of changing temperatures and weather conditions in South Korea may have an impact on the population of mosquitoes, and it affects the population of dogs at risk of heartworm infection. Mathematical modeling has become an important measure for analyzing the epidemiological characteristics of infectious diseases. However, canine heartworm infection transmission has not been reported yet through mathematical modeling. We develop a mathematical model of canine heartworm infection to predict the population of infected dogs depending on the vector (mosquito) population using a susceptible, exposed, infected, and recovered model. Simulation results show that after 1 year, 3,289 dogs out of 73,602 (about 4.5%) are exposed and 134 (about 0.2%) are infected. Only 0.2% of susceptible dogs become infected after 1 year. However, if all exposed dogs are maintained in the same circumstances without any treatment, then the number of infected subjects will increase over time. This may increase the possibility of other dogs, especially dogs that live outside, being infected.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10335-10337
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• 2015

Background: Gastric cancer is considered as the second most prevalent cancer in Iran. The present research sought to identify high risk clusters of gastric cancer with mapping using space-time scan statistics. Materials and Methods: The present research is of descriptive type. The required data were gathered from the registered cancer reports of Cancer Control Office in the Center for Non Communicable Disease of the Ministry of Health (MOH). The data were extracted at province level in the time span of 2004-9. Sat-Scan software was used to analyse the data and to identify high risk clusters. ArcGIS10 was utilized to map the distribution of gastric cancer and to demonstrate high risk clusters. Results: The most likely clusters were found in Ardabil, Gilan, Zanjan, East-Azerbaijan, Qazvin, West-Azerbaijan, Kurdistan, Hamadan, Tehran and Mazandaran between 2007 and 2009. It was statistically significant at the p-value below 0.05. Conclusions: High risk regions included Northern, West-North and central provinces, particularly Ardabil, Kurdistan, Mazandaran and Gilan. More screening tests are suggested to be conducted in high risk regions along with more frequent epidemiological studies to enact gastric cancer prevention programs.

• Journal of the Korean Electrochemical Society
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• v.19 no.3
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• pp.95-100
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• 2016

A method for electrochemical degradation of the perchlorate anion ($ClO_4{^-}$) using mercury film electrode has been studied. Electrochemical method has relatively simple pre-treatment. However, electrochemical method should avoid interference from hydrogen evolution at the applied potential to degradation of perchlorate ion, and thus applied electrode should have large hydrogen overvoltage which suppressed the hydrogen evolution at the working reduction potential to prevent hydrogen evolution. In this study, we used mercury film electrode as a working electrode which has a large overvoltage. Ag / AgCl (sat. NaCl) was used as a reference electrode, and platinum was used as a counter electrode. Mercury film electrode was made by cyclic voltammetry (CV) method. The deposition time was decided as 10 minute, and the stability of the mercury electrode in perchlorate solution was confirmed by CV. The reduction potential of perchlorate was checked by using CV method, and decomposition of perchlorate was performed by using chronoamperometric (CA) method. Also, ion chromatography (IC) was used to confirm the degradation rates of perchlorate.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.6
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• pp.674-682
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• 2014

The purpose of this study was to identify the effect of applying oriental music therapy and reliability of electroencephalogram(EEG) equipment. The study was approved by the critical trial judge committee from ${\bigcirc}{\bigcirc}$(IRB No. 2013-07) university. In order to measure test-retest reliability for 15 subjects, EEG for same participants were measured using same method mentioned above after 2 hours from the first measurement. Same provider implemented to each person at same time. Firstly, EEG was measured for 5 minutes after the subject with attached electrodes sat on chair comfortably for 10 minutes. Then, the subject was given mental stress using the four fundamental arithmetic operations for 5 minutes, and measured EEG for another 5 minutes. After that the subject sat on the chair comfortably listening oriental medicine music therapy for 5 minutes, and EEG was measured for 5 minutes again. There was no side effect regarding music therapy reported. Raw data, which was measured in each step, were converted through FFT(fast fourier transform) and analyzed after divided into certain frequency including ${\alpha}$ wave, ${\beta}$ wave, ${\theta}$ wave, immersion wave, stabilization wave, sef100 wave, and sef95 wave. Data were analyzed using wilcoxon signed rank test, Intraclass correlation coefficient(ICC), repeated measures ANOVA with the SPSS program. In test-retes method, there were significantly differences in ${\alpha}$ wave, ${\beta}$ wave, immersion wave, stability wave, ${\theta}$ wave, sef100 wave, sef95 wave. ICC has shown a high degree of reliability that it was ${\alpha}$ wave .877, ${\beta}$ wave .855, ${\gamma}$ wave .895, immersion wave .897, stability wave .816, ${\theta}$ wave .904, sef100 wave .910, sef95 wave .776. Also, there was a statistically significant difference in ${\alpha}$ wave after applying oriental music therapy. Based on these results, it is considered that average of the channel EEG and application of oriental music therapy would be practiced by increase of sample size using this machine.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.6
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• pp.747-752
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• 2006

In this paper, the adaptive fuzzy sliding mode controller with two systems is designed. The existing sliding mode controller used to $approximation{\^{u}}(t)$ with discrete sgn function and sat function for keeping the state trajectories on the sliding surface[1]. The proposed controller decrease the disturbance for uncertain control gain and This paper is concerned with an Adaptive Fuzzy Sliding Mode Control(AFSMC) that the fuzzy systems ate used to approximate the unknown functions of nonlinear system. In the adaptive fuzzy system, we adopt the adaptive law to approximate the dynamics of the nonlinear plant and to adjust the parameters of AFSMC. The stability of the suggested control system is proved via Lyapunov stability theorem, and convergence and robustness properties ate demonstrated. Futhermore, fuzzy tuning improve tracking abilities by changing some sliding conditions. In the traditional sliding mode control, ${\eta}$ is a positive constant. The increase of ${\eta}$ has led to a significant decrease in the rise time. However, this has resulted in higher overshoot. Therefore the proposed ${\eta}$ tuning AFSMC improve the performances, so that the controller can track the trajectories faster and more exactly than ordinary controller. The simulation results demonstrate that the performance is improved and the system also exhibits stability.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.1
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• pp.26-32
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• 2001

Influence of various rates of fractionated raw cow manure on hydraulic conductivity of the soil was observed. The fractionated raw cow manure(hereafter as FRCM) incorporated into soil. The hydraulic conductivity was measured for the double-layered soil while maintaining the water head by 5 cm over the soil surface. The influence on the mobility of $NO_3{^-}$-N transformed from the FRCM was analyzed. The upper layers (Wolgok series) were made with FRCM ranging from 0% to 10.4 % on weight basis for air-dried soil while the organic matter in the bottom layers (Chungwon series) was removed by combustion. The initial bulk densities for both layers were adjusted to $1.25g\;cm^{-3}$. In this experiment the $K_{sat}$ for the upper layer gradually decreased from $4.71{\times}10^{-3}cm\;min^{-1}$ to $1.2{\times}10^{-3}cm\;min^{-1}$ with increasing the rate of the FRCM from 0 % to 10.4%, while the Ksat of the bottom layer was maintained as $3.7cm\;min^{-1}$. For the double-layered soil columns, the $K_{sat}$ decreased with increasing rate of FRCM at the upper layer from $1.7{\times}10^{-3}cm\;min^{-1}$ to $8{\times}10^{-4}cm\;min^{-1}$ as the rate of organic matter increased from 0 % to 10.4 %, while it took almost 7 days to 64 days to obtain the steady state $K_{sat}$ The elution patterns of $NO_3{^-}$-N and $NH_4{^+}$-N showed that the amounts of both $NO_3{^-}$-N and $NH_4{^+}$-N rapidly approached to the maximum ranging from $14.8mmol_c\;kg^{-1}$ to $0.58mmol_c\;kg^{-1}$ as the rate of FRCM decreased from 10.7 % to 0 % which is equivalent to indigenous amount of $NO_3{^-}$-N and $NH_4{^+}$-N. And the amounts of $NO_3{^-}$-N were approximately three or four time than those of $NH_4{^+}$-N, indicating that the transformation rate of $NO_3{^-}$-N was improved by the higher FRCM rate. Thus, the ability of a soil to supply N can be predicted from its mineralization parameters and leaching potentials influenced by water flow regime in soil.