• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.176-179
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• 2005

A case-study in classroom acoustics was conducted and the effects of two types(system air conditioner and packaged air conditioner) of air conditioner were investigated. Acoustical measurements were made in two different classrooms. Each classroom has different acoustics showing sound quality of air conditioner. Mental concentration test was conducted to evaluate the effects of air conditioner noise with different sound presure level(dBA). Speech intelligibility test was also planed with adopting Korean phonetic balanced words.

• Journal of Nutrition and Health
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• v.36 no.9
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• pp.918-923
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• 2003

L-theanine Is an amino acid in green tea and has been known to decrease serotonin and increase norepinephrine in rat brains, and also reported to produce mental relaxation, lower blood pressure and improve learning ability in human beings. But, few studies on these effects for human beings have been conducted so far. This study was conducted to evaluate the effect of L-theanine on the release of brain alpha waves known to be related with mental relaxation and concentration. Twenty healthy male volunteers aged 18 to 30 years without any Physical and Psychological diseases were recruited through written advertisement. Alpha power values of EEG as a surrogate marker of mental relaxation and concentration were measured in frontal and occipital regions for 40 minutes after administration of four placebo or test tablets and 20 minute resting period. The same procedure crossed over at 7-day intervals. We analyzed average alpha power values in frontal and occipital regions at 10 minute intervals. Repeated ANOVA revealed that there were significant differences of occipital alpha power values between placebo and test groups with high anxiety (p < 0.05). The mean values at 20,30,40,50 and 60 minute intervals were 0.23, 024, 0.28, 0.25 and 0.34 in placebo, respectively and 0.23, 0.29, 0.40, 0.34, and 0.45 in test, respectively. But there were no significant differences of frontal and occipital alpha power values between placebo and test groups with low anxiety (p > 0.05) . The results of this study suggest that L-theanine containing tablets promote the release of alpha waves related to mental relaxation and concentration in young adult males.

• Journal of The Korean Society of Clinical Toxicology
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• v.2 no.1
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• pp.45-48
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• 2004

Paraquat, a widely used herbicide, is extremely toxic, causing multiple organ failure in human. Many treatment modality has been used, but now paraquat is very fatal drug. Elimination rate of plasma paraquat seems to be a factor for the survival rate. So early diagnosis and early treatment are very important. Plasma paraquat concentration could be measured by radioimmunoassay. But it is impossible that the test was done at Emergency room and the result was checked immediately. There was relation between plasma paraquat concentrations and urine paraquat concentration. Because of its simplicity and low cost, urine paraquat concentration test is complementary to the plasma concentration measurement. If the patient has psychotic problem or unconscious mental state, and is observed unexplained dyspnea and oral ulcer, urine paraquat test is very important to rule out acute paraquat intoxication. We experienced a patient who was presented as unexplained acute renal failure initially and was diagnosed as paraquat intoxication later.

• Journal of Korean Biological Nursing Science
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• v.1 no.1
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• pp.100-114
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• 1999

This study was done to investigate the effects of rapidly-rotating shift work of two-day interval on fatigue level and the concentration of urinary 17-KS, $Na^+,\;Cl^-$. The subjects were 20 nursing college students(control group) and 15 nurses in a university hospital and the study was done from Apr. 21 to May 4th, 1999. In the test group, each 5 nurses were allocated to day shift(8 AM-4 PM), evening shift(4 PM-12 MN) and night shift(12 MN-8 AM) respectively. The fatigue level were measured 30 minutes after work start on the 2nd day of work shift. Urine specimens were collected at 8 AM, 4 PM and 12 MN on the 2nd day of work shift in the control group and 30 minutes before and after work on the 2nd day of work shift in the test group. The data were analyzed with SPSS(for Window, ver 7.5). Statistical analysis was performed by using t-test, paired t-test and ANOVA. The results were as follows. 1. The perceived fatigue level in shift work 1) The physical and mental fatigue level were significantly higher in night shift than that in day or evening shift(p<0.05). In the neuro-sensory fatigue level, night shift showed higher tendency than that in day or evening shift, but there were no significant differences between each shifts. 2) Comparison between the control group and the test group: Physical fatigue level was significantly higher in night shift than that in day or evening shift of the control group(P<.001). Mental fatigue level was significantly higher in day or night shift than that in evening shift of the control group(P<.05). In the neuro-sensory fatigue level, test group showed higher tendency than that in the control group, but there were no significant differences between two groups. 3) The total fatigue level was higher in night shift than that in day shift or evening shift(P<.05). In comparing with the control group, night shift and day shift showed higher total fatigue level than that in the control group(p<0.05). 2. The concentration of urinary 17-KS, $Na^+$ and $Cl^-$ In the control group, urinary 17-KS, $Na^+$ and $Cl^-$ showed higher level in afternoon that in morning and night. In the test group, cr in day and evening shift and $Na^+$ in evening shift showed higher level at the end of work. The 17-KS concentration at the begining and the end of work in three shift groups were lower than those in control group(p<0.05), however, $Cl^-$ concentration at the begining of work in day shift, and the end of work in day and evening shift were higher than those in control group(p<0.05). $Cl^-$ concentration at the begining and end of work in night shift were considerably higher than those in control group repectively(p<0.1, p<001). $Na^+$ concentration showed a higher tendency in three shift groups except at the begining of work in night shift, but there were no statistical difference. In comparing concentration of the 17-KS, $Na^+$ and $Cl^-$ among the shift groups, 17-KS concentration showed a lower tendency and $Na^+,\;Cl^-$ showed a higher tendency in night shift: The result of this study showes that biorhythm of shift work nurse was irregular. Fatigue level as the subjective index for evaluating the health problem concerning shift work was higher in night shift and proved to be in accordance with the concentration of urinary 17-KS, $Na^+$ and $Cl^-$ used as objective indices. Disturbation of biorhythm and work stress due to night shift seems to cause the health problem of nurses and decrease of work efficiency. It is considered that work regualtion is necessary for the rational management of the nursing administration.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.347-349
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• 2009

Air quality of indoor space environment is affected by various pollutants like as particles and chemical stuffs. The indoor air pollution affects directly the human respiration organs to cause consequently unpleasant mental status. The $CO_2$ concentration level is one of the harmful components of air pollutants. Major factor to increase the $CO_2$ concentration level is the people's breath amount in indoor. The car exhaust gas diffused from the around road also has strong affect on $CO_2$ concentration. There are some other reasons to affect the $CO_2$ concentration change, such as, real-time change of the population movement, closeness to the indoor air flow inlet window and changes in road car traffic amount. A remote monitoring system to measure environmental indoor air pollution concerning on the $CO_2$ concentration was studied and installed realized set-up model. Zigbee network configuration was applied for this system and the $CO_2$ concentration data were collected through USN network. A software program was developed to assure systematic analysis and to display real-time data on web pages. For the experimental test various condition was set up, like as, window opening, stopping air condition operation and adjusting fan heater work, etc. The analysis result showed the relation of various environmental conditions to $CO_2$ concentration changes. The causes to increase $CO_2$ concentration were experimentally defined as windows closing, the stopping air condition system, fan heater operation. To keep the $CO_2$ concentration under the legally required ppm level in public access indoor space, the developed remote measurement system will be usefully applied.

• Proceedings of the Ginseng society Conference
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• 1984.09a
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• pp.215-223
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• 1984

Panax ginseng has often been suggested as a geriatric restorative. This study is a double blind crossover trial to test whether ginseng can improve function in subjects with the depression and reduced abilities associated with senescence. 49 screened subjects were given 1500 mg Korean Red ginseng and identical placebo each for ten days, with a washout period in between the dosages. Standard tests of mental function, neuromuscular reflexes, responsiveness, mood and well being were used. The subjects were somewhat better at the co-ordination and speed test ('number copying') but tests of concentration and memory ('Concentration', 'Paired Association', 'Digit Span' and 'Object Learning') gave equivocal results. There were small improvements in mood and well being ('Life Satisfaction' and 'General Health Questionnaire') while the subjects indicated increased energy, alertness and less sleep, but also less happiness on the daily analogue scales. The major result was a highly significant improvement in reactivity, speed and co-oridnation at the tapping test, and the visual, auditory and disjunctive reaction timer. These are the most objective and accurate tests used in this trial. It is therefore concluded that ginseng can increase function in senile individuals. This effect is most easily visualisable in objective psychophysical tests, rather than the more subjective memory and concentration tests.

• Journal of The Korean Society of Clinical Toxicology
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• v.15 no.1
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• pp.40-46
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• 2017

Purpose: Glufosinate ammonium (GA; phosphinothricin) can induce neurological complications such as altered mental status, amnesia, and convulsions. This study was conducted to evaluate whether blood lipid profiles can help predict convulsions in patients with GA poisoning. Methods: This study was a retrospective review of data acquired at a tertiary academic university hospital from March 2014 to July 2016. Independent t-test, Mann-Whitney test and Analysis of covariance (ANCOVA) of demographic and laboratory findings of 50 patients with GA poisoning were performed to identify correlations of general characteristics and laboratory findings, including blood lipid profiles of GA-poisoned patients between with and without convulsions. Results: Convulsion as a GA complication showed a significant association with poison volume, age, white blood cell count, and creatine phosphokinase (CK), albumin, lactate dehydrogenase (LDH), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) content in blood according to an independent t-test and Mann-Whitney test. However, ANCOVA demonstrated significant association with LDL and triglyceride. Conclusion: Blood lipid profiles, especially serum LDL and triglyceride, were useful in predicting convulsions in patients with GA poisoning.

• Proceedings of the Ginseng society Conference
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• 1978.09a
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• pp.85-92
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• 1978

The aim of the double blind test was to assess the prophylactic and therapeutic efficacy of the preparation GINSANA, containing the standardized ginseng extract PHARMATON G115,. The determination was carried out with special emphasis on the following features : general physical condition, physical performance, mental performance, enjoyment of life/mood, concentration and memory, as well as sleeping habits. Sixty test persons took part in the study, men and women between the ages of 22 and 80. The 90-day test was carried out in the form of a double blind experiment. Experimental measurements were made and the persons were also questioned. The reaction time, the optical merging threshold, the coordination of both hands and the recovery quotients, as well as the recovery rates were analyzed. The results for the serum group were clearly better than those for the placebo group, particularly for the characteristics: general physical condition, physical performance and sleeping habits. The results of the test methods used, especially with regard to the reaction time, the coordination of both hands, the recovery quotient and the recovery period, permit the following conclusion to be drawn: when administered for several weeks, GINSANA has a positive action, in the sense of an activation of the entire personality by the ginseng glycosides contained in the standardized Extracts G115.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.12
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• pp.2357-2364
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• 2017

Recently, smart wearable devices for monitoring health status have been utilized as interest in health care has increased. In this paper, we developed a fatigue measurement system that works with smart wearable devices. Unlike physical fatigue that is restored when you take enough rest, mental fatigue can decrease the efficiency or concentration of work, so you can monitor your mental health status through measurements. This system provides the function to transmit the measured data from the smart wearable device to the smartphone and to calculate the mental fatigue. A fatigue index was developed to measure fatigue and expressed as a number from 1 to 5. In addition, the results of the fatigue calculation and the survey were compared with the results of the independent sample t-test. Therefore, this system will be used to help users manage their health efficiently.

• Korean Journal of Biological Psychiatry
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• v.18 no.2
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• pp.95-100
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• 2011

Objectives To evaluate the drug interactions between aripiprazole and haloperidol, authors investigated plasma concentrations of those drugs by genotypes. Method Fifty six patients with a confirmed Diagnostic and Statistical Manual of Mental Disorders 4th edition diagnosis of schizophrenia were enrolled in this eight-week, double blind, placebo-controlled study. Twenty-eight patients received adjunctive aripiprazole treatment and twenty-eight patients received placebo while being maintained on haloperidol treatment. Aripiprazole was dosed at 15 mg/day for the first 4 weeks, and then 30 mg for the next 4 weeks. The haloperidol dose remained fixed throughout the study. Plasma concentrations of haloperidol and aripiprazole were measured by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) at baseline, week 1, 2, 4 and 8. $^*1$, $^*5$, and $^*10$ B alleles of CYP2D6 and $^*1$ and $^*3$ alleles of CYP3A5 were determined. The Student's T-test, Pearson's Chi-square test, Wilcoxon Rank Sum test and Logistic Regression analysis were used for data analysis. All tests were two-tailed and significance was defined as an alpha < 0.05. Results In the frequency of CYP2D6 genotype, $^*1/^*10$ B type was most frequent (36.5%) and $^*1/^*1$ (30.8%), $^*10B/^*10B$ (17.3%) types followed. In the frequency of CYP3A5 genotype, $^*3/^*3$ type was found in 63.5% of subjects, and $^*1/^*3$ type and $^*1/^*1$ were 30.8% and 5.8% respectively. The plasma levels of haloperidol and its metabolites did not demonstrate significant time effects and time-group interactions after adjunctive treatment of aripiprazole. The genotypes of CYP2D6 and 3A5 did not affect the plasma concentration of haloperidol in this trial. No serious adverse event was found after adding aripiprazole to haloperidol. Conclusion No significant drug interaction was found between haloperidol and aripiprazole. Genotypes of CYP2D6 and 3A5 did not affect the concentration of haloperidol after adding aripiprazole.