• Korean Journal of Veterinary Service
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• v.22 no.1
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• pp.61-70
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• 1999

This study is concerned with assessment of diethylnitrosamine(DEN) induced liver cell carcinogenesis by measurement of changes preceding the development of neoplasms. Therefore, it was undertaken to investigate the changes of liver-specific enzyme activities in rats (Sprague-Dawley) by ad libitum feeding of DEN. And also, as another objective index in urine, the level of urinary biopterin was measured by high performance liquid chromatography(HPLC) method. The results were as follows ; 1. Minor behavioral change, brittleness of hair and decreased amount of water and diet intake were observed in rats 7 weeks after DEN administration. 2. The body and liver weights were significantly(p<0.05) decreased in rats 11 weeks after DEN administration. 3. The ratio of liver weight to body weight was rather stable and not significantly decreased in the all treatment groups. 4. The liver specific enzyme activities(AST, ALT,$\gamma$-GTP) were significantly(p<0.05) increased in all treatment groups compared to control group. 5. Compared to normal level, urine biopterin level was significantly (p<0.05) increased in all treatment groups(p<0.05). In conclusion, this result confirmed that the DEN was one of the potent hepatocarcinogens. In experimental model of rats exposed to DEN, the results indicated that values of liver specific enzyme activities(AST, ALT, $\gamma$-GTP) and urine biopterin level could be useful complementary tumor indices.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.6
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• pp.531-542
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• 2016

This experiment was conducted to verify whether or not chronic consumption of liquor prepared with Gastrodiae rhizoma exhibits antioxidant activity in brain tissue of rats. In the experiment, male Sprague-Dawley rats were given a liquid diet containing 6% (GA6), 18% (GA18), and 36% (GA36) of total calories as liquor for 6 weeks. The control rats (GAC6, GAC18, GAC36) received an isocaloric diet containing Soju instead of liquor. Caloric intakes and body weight gains of the 36% groups were significantly lower than those of the 6% and 18% groups (p<0.05), whereas alcohol intakes were significantly high in the 36% group (p<0.05). MDA contents of plasma and brain showed a positive correlation with alcohol intakes of the liquor and Soju consuming groups. Especially, contents of MDA were significantly higher in the 18% and 36% groups than the 6% group (p<0.05). SOD activities of serum and brain were significantly highest in the 18% group, and they tended to be higher in the liquor consuming groups compared with the control group. Catalase activity of serum showed no significant changes in the three groups consuming liquor, and catalase activity of brain tissue significantly increased in the GA18 group compared with the control group (p<0.05). In the liquor consuming groups, TAC level of serum tended to be higher in the GA36 group compared with the control group (p<0.05). However, TAC level of brain tissue showed no significant changes between the liquor consuming and control groups. These results show that as alcohol intake increased by chronic administration of liquor and Soju, brain tissue of rats was damaged more due to oxidative stress. However, a liquid diet containing 18% of total calories as liquor instead of Soju is expected to have a protective effect on brain damage induced by oxidative stress.

• Journal of Bio-Environment Control
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• v.10 no.4
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• pp.251-257
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• 2001

This experiment was conducted to investigate the effect of chitosan on the growth and yield of fall-planted potatoes. The research was carried out in fall-planted potatoes from August 2000 to Aprial 2001 at the height of 250m above sea level in Jeju Island. Soaking for 30 min. of seed potatoes in 200 times diluted solution of 3% liquid chitosan shortened days to emergence by 4 to 6 days. Stem length, number of stems and number of stolons per plant were 56.5 cm, 4.3, and 19.0, respectively, when seed potatoes were soaked for 30 min. in 200 times diluted solution of 3% liquid chitossan. Total potato yield in this treatment reached 2,963 kg per 10a and was significantly greater than in other treatments. Yield of marketable tubers (greater than 30g) per 10a for treatment of seed potatoes soaking in 200 times diluted solution of 3% liquid chitosan and for treatment of foliage spray with 200 times diluted solution of 3% liquid chitosan plus chitosna power (10 kg per 10a) miximg with soil was 2,761 kg and 2,628 kg, respectively. Contents of Mg, Fe and B were the greatest in the treatment of 30 min. soaking of seed potatoes in 200 times diluted solution of 3% liquid chitosanm. The increased contents of these elements are considered to have caused yield increase as a result of increased chlorophyll content for photosynthesis.

• Journal of IKEEE
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• v.21 no.2
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• pp.158-161
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• 2017

In this paper, we propose Total RMS(Radiation Monitoring System) for nuclear and nuclear medicine. The proposed system can expand and control Stack Monitor, Area Monitor, and Water(Liquid) Monitor into one system, and can monitor the signals measured by each radiation detector in an integrated manner. The proposed system consists of a sensor module that detects the radiation, a display unit that displays the radiation dose near the radiation detection location, an alarm unit that reports the alarm when the detected radiation dose reaches the danger level, A Main Hub for collecting and storing the contents to the remote monitoring system, and an RMS Monitoring Unit for clearly displaying the measured radiation dose at the remote site. In order to evaluate the performance of Total RMS for the proposed nuclear and nuclear medicine field, it is confirmed that the measurement uncertainty is less than 8.5% and it operates normally within ${\pm}15%$ of the international standard.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.1
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• pp.1-8
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• 2013

A liquid-monopropellant hydrazine thruster has several outstanding advantages such as relatively-simple structure, long/stable propellant storability, clean exhaust products, and so on. Therefore hydrazine thruster has such a wide application as orbit and attitude control system (ACS) for space vehicles. A hydrazine thruster with the medium-level thrust to be used in the ACS of space launch vehicles (SLV) has been developed, and its ground firing test result is presented in terms of thrust, impulse bit, temperature, and chamber pressure. It is verified through the performance test that the response and repeatability of thrust are very excellent, and the thrust efficiencies compared to its ideal requirement are larger than 93%.

• Toxicological Research
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• v.27 no.1
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• pp.49-52
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• 2011

The aim of this study is to investigate how many leiomyoma patients are exposed to bisphenol-A (BPA), an endocrine disruptor, and whether the serum concentration of BPA is related to leiomyoma growth. Initially, 128 patients were divided into one control and three leiomyoma groups (mild, moderate and severe) according to the size of the leiomyomas. Serum BPA concentrations were measured by liquid chromatography and mass spectrometry (LC/MS). Nearly two-thirds of leiomyoma patients were exposed to BPA and the range of BPA was from non-detection to 2.603 ng/ml. The mean BPA concentrations in the groups were $1.015{\pm}0.775\;ng/ml$ (control), $0.774{\pm}0.834\;ng/ml$ (mild), $1.261{\pm}0.797\;ng/ml$ (moderate) and $1.244{\pm}0.860\;ng/ml$ (severe) (p = 0.158). After recombination into two group, Group 1 (control plus mild) vs. Group 2 (moderate plus severe), higher level was found in Group 2 even with no statistical significance (p = 0.06). In conclusion, about two-thirds of leiomyoma patients were exposed to BPA, but it may not have growth promoting effect on leiomyoma.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.3
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• pp.398-402
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• 2008

Recently, the development of superconducting fault current limiters (SFCLs) has been required as power demands increase in the power system. A distribution-level prototype resistive SFCL using coated conductor (CC) has been developed by Hyundai Heavy Industries Co., Ltd. and Yonsei University for the first time in the world. The ratings of the SFCL are 13.2kV/630A at normal operating condition. A novel non-inductive winding method is used in fabricating coils so there is almost zero impedance during normal operation. The distribution SFCL is cooled by sub-cooled liquid nitrogen $(LN_2)$ of 65K and 3 bar to enhance cryo-dielectric performance, critical current density, and thermal conductivity. In order to make reliable operation of an SFCL in real power systems, we monitored and controled its operation conditions by using supervisory control and data acquisition (SCADA) method. Thus, a monitoring system for the SFCL employing information technology (IT) is proposed and developed to be on the lookout for the operation conditions such as inside temperature, inside pressure, $LN_2$ level, voltage and current. Since operation temperature should be kept constant, bang-bang control for temperature feedback with a heater attached to the cold head of cryo-cooler is applied to the system. Short-circuit tests with prospective fault current of 10kA and AC dielectric withstand voltage tests up to 143kV for 1 minute were successfully performed at Korea Electrotechnology Research Institute. This paper deals with the development of a distribution level SFCL and its monitoring system for reliable operation.

• Anxiety and mood
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• v.5 no.1
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• pp.14-20
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• 2009

Objective : The objective of this study was to examine the relationship between plasma serotonin concentration and posttraumatic stress disorder (PTSD) symptoms in chronic PTSD patients who have been taking medication. Methods : Plasma serotonin level of 14 PTSD patients and a control group of 28 Vietnam War veterans was measured by HPLC (high performance liquid chromatography). The Combat Exposure Scale (CES), Mississippi Scale for Combat-Related Posttraumatic Stress Disorder (M-PTSD), Clinician Administered PTSD Scale (CAPS), Hamilton Rating Scale for Depression (HRSD), and Hamiltion Anxiety Scale (HAS) were used to evaluate PTSD symptom severity. Results : Serotonin level was significantly higher in the PTSD group than in the control group (p=0.036, p=0.006, respectively). M-PTSD (p<0.001), CAPS (p<0.001), HRSD (p<0.001), and HAS (p<0.001) scale scores were significantly higher in the PTSD group than in the control group; however, the CES score failed to show a significant improvement (p=0.964). There were no significant differences between plasma serotonin and PTSD symptoms. Conclusion : In chronic PTSD patients who have been taking medications, we can not predict treatment effect and symptom severity by measuring only plasma serotonin levels. PTSD is a complicated disorder which may likely be related to a variety of neurotransmitter systems. Therefore, further research which investigate relationships with norepinephrine, dopamine, and other neurotransmitters as well as serotonin is needed to improve the treatment of PTSD.

• Journal of Korean Academy of Nursing
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• v.29 no.2
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• pp.445-455
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• 1999

This study has been conducted on the nonequivalent control group pretest-posttest design in quasi experimental basis and newly born premature infants from intensive care unit of G Medical University Hospital in Inchon Metropolitan were selected in two groups of 21 infants each. The first group for experimental and the other for control. Data has been collected form October 30, 1997 to August 29, 1998. For the experimental group tactile and kinesthetic stimulation was applied 2 times a day for 10 days(10 : 00~11 : 00 hours in the morning and 17 : 00~18 : 00 in the afternoon). As a weight weighing instrument. electronic indicator scale(Cas Co. korea) was used. To determine urine cortisol concentration level in stress hormone, radio immune assay method was used. And high performance liquid chlomatography was used to determine urine norepinephrine, concentration level To determine behavior status, tools developed by Anderson et at(1990) and remodeled by Kim Hee-Sook(1996) were used. Collected data were analyzed with the SAS program using x$^2$-test, student t-test, repeated measures ANOVA and paired t -test. The result were as follow. 1. As for the daily weight gain. the experimental group showed first change in weight and this group also showed higher weight in the average weight than the control group. Statistically, however, there was no significant factor between the two group. 2. The cortisol concentration in urine showed decrease in the experimental group norepinephrine concentration in urine showed increase in both experimental and control groups. No statistical significance was shown between the two groups. 3. In the aspect of behavior status. the experimental group showed statistical significance by showing inactive in the state of alert and conversion to a positive state than the control group. In conclusion, the sensory stimulation in this study showed a positive aspect through there was no statistical significance in the weight gain and urine stress hormone concentration. In the behavior status, there was statistical significance in the frequency of staying inactive in the state of alert and conversion to a positive state.

• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.288-291
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• 1999

The PID (Proportional-Integral-Derivative) controller is widely used in the industries for more than fifty years with the well known Ziegler-Nichols tuning method and others varieties. However, most of the PID controller being used in the real practice still require trial and error adjustment for each process after the tuning method is done, which is consuming of time and needs the operator experiences to obtain the best results for the controller parameter. In order to reduce the inconvenience in the controller tuning, this paper presents a design of an automatic PID controller parameter analyzer being used as a support instrument in the industrial process control. This analyzer is designed based on the tuning formula of Dahlin to synthesize the PID controller parameter. Using this analyzer, the time to be spent in the trial and error procedures and its complexity can be neglected. Experimental results using PID controller parameter synthesized from this analyzer to the liquid level control plant model and the fluid flow control plant model show that the responses of the controlled systems can be efficiently controlled without any difficulty in mathemathical computation.