• 대한임상독성학회지
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• 제19권1호
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• pp.24-30
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• 2021

Purpose: In Korea, it is predicted that the proportion of drug abusers among patients visiting the emergency room will soon increase. Several emergency medical institutions in Korea are conducting field urine screening tests for poisoning. In this study, we investigated the characteristics and usefulness of urine toxicology screening tests. Methods: The medical records of patients with positive results for tetrahydrocannabinol and methamphetamine from urine toxicology screening tests at a tertiary university hospital from August 2016 to August 2019 were reviewed retrospectively. The subjects were classified into positive and false-positive groups, and their clinical characteristics were compared and analyzed. Results: Of the 2,026 patients surveyed, 823 patients (40.6%) tested positive for one or more drugs. Among them, 12 cases (0.6%) were positive for methamphetamine and 40 cases (2.0%) were positive for tetrahydrocannabinol. The positive and the false-positive rates for methamphetamine were 66.7% and 33.3%, respectively. The positive and the false-positive rates for tetrahydrocannabinol were 2.5% and 97.5%, respectively. Conclusion: Methamphetamine showed a relatively low false-positive rate in our study. Therefore, this test seemed to assist in diagnosing methamphetamine poisoning when considered together with the present illness and physical examination results. On the other hand, the high false-positive rate for tetrahydrocannabinol tests indicates that this test was unlikely to assist in diagnosing tetrahydrocannabinol poisoning. However, considering the growing trend of illegal drug abusers in Korea, it may still be useful as a diagnostic tool for identifying drug users.

• Parasites, Hosts and Diseases
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• 제50권3호
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• pp.225-227
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• 2012

The seroepidemiological status of toxoplasmosis was surveyed among the residents of Cheorwon-gun, Gangwon-do by means of ELISA using a crude extract antigen of Toxoplasma gondii. The sera of 1,661 adult residents (866 males and 795 females) were collected and checked for IgG antibody titers, which showed 17.0% positive rate (282 sera). The positive rate was significantly different between the sex; 20.6% for males and 13.1% for females (P<0.05). The positive rates were higher in fifties of males (28.7%) and forties of females (20.0%). This positive rate of toxoplasmosis in Cheorwon-gun residents is regarded as the highest among the surveys of different geographical regions of Korea. This high positive rate may due in part to peculiar geographical locality of the surveyed area near the naturally well preserved demilitarized zone (DMZ) or presumably consumption of the pork imported from high endemic nations. Therefore, it is necessary to study further the epidemiology of toxoplasmosis in Cheorwon-gun.

• 동아시아식생활학회지
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• 제14권6호
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• pp.634-639
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• 2004

An eight-week-old male ICR mouse, which was induced with acute alcohol and sub-acute alcohol poisoning condition, was administered with bohee tea(Camelia sinensis L) extract. After oral administration of bohee tea and inducement of acute alcohol poisoning condition, the mouses blood alcohol concentration became as low as that of the normal control group. Its decrease rate was 87.26%, in comparison with that of the positive control group. Moreover, its blood GOT activity decreased with a rate of 93.1 % until it reached the normal level, as opposed to that of the positive control group. In addition, the GOT activity, despite rising after the alcohol intake, decreased(p<0.05) significantly after administration of each sample and reached the normal level. The bohee tea group experienced a significant decrease in the GOT activity, compared with the A1codex group and the Drink group. The GPT activity of the Alcodex group decreased by 11 % compared with that of the positive control group. The CTP activity of the bohee tea group decreased by 8.2%, while that of the Drink group decreased by 6.5%(P<0.05). However, there were no significant differences between the results in the control group and those of the test group. The bohee tea group's hepatic ADH activity increased by 22.7% compared with that of the positive control group. On the other hand, the hepatic ADH activity of the Drink group increased by 33.6% while that of the A1codex group increased by 20.4%. On the contrary, the bohee tea extract, the hepatic ALDH did not manifest any significant difference as compared with the normal control group. However, its decrease rate was about 16.67% as compared with that of the positive control group. The Drink group, meanwhile, obtained a decrease rate of about 21.59%.

• 보건교육건강증진학회지
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• 제31권1호
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• pp.45-56
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• 2014

Objectives: This study aimed to examine how the relationship between socioeconomic factors at the macro level and suicide mortality rate of Korea was different from that of other OECD countries. Methods: We created OECD panel data of 29 OECD countries from 1985 to 2006 and analyzed the relationship between socioeconomic factors and suicide mortality rate for separate age and sex groups using a fixed-effect model. Economic factors included per capita GDP, per capita GDP growth rate, unemployment rate, and women's economic participation rate. Social factors included birth rate, alcohol consumption, and the percentage of population 65 and older. Results: Unemployment rate had a positive relationship with suicide in other countries but it had a negative relationship in some groups of Korea. Women's economic participation rate was both positively and negatively related with suicide in Korea but it did not relate to suicide in others. The negative relationship of birth rate and the positive relationship of alcohol consumption with suicide were evident in Korea, which were not found in other countries. The percentage of population 65 and older was negatively correlated in some female groups in Korea, while no significant relationship was found in other countries. Conclusions: Korea was substantially different from other OECD countries in the relationship between socioeconomic factors and suicide mortality rate.

• 대한수학회보
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• 제48권3호
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• pp.523-537
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• 2011

A receiver operating characteristic (ROC) curve plots the true positive rate of a classier against its false positive rate, both of which are accuracy measures of the classier. The ROC curve has several interesting geometrical properties, including concavity which is a necessary condition for a classier to be optimal. In this paper, we study the nonparametric maximum likelihood estimator (NPMLE) of a concave ROC curve and its modification to reduce bias. We characterize the NPMLE as a solution to a geometric programming, a special type of a mathematical optimization problem. We find that the NPMLE is close to the convex hull of the empirical ROC curve and, thus, has smaller variance but positive bias at a given false positive rate. To reduce the bias, we propose a modification of the NPMLE which minimizes the $L_1$ distance from the empirical ROC curve. We numerically compare the finite sample performance of three estimators, the empirical ROC curve, the NMPLE, and the modified NPMLE. Finally, we apply the estimators to estimating the optimal ROC curve of the variance-threshold classier to segment a low depth of field image and to finding a diagnostic tool with multiple tests for detection of hemophilia A carrier.

• 한국동물위생학회지
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• 제31권1호
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• pp.79-86
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• 2008

In this study two stage investigation was used for seroprevalence of Neospora caninum in cattle between January, 2005 and November, 2007; first stage was to examine positiveness of the farms selected randomly, second was to test all individual cow in positive farms. A total of 850 sera were collected from 170 farms for the first stage, and positive rate of farm and head were 23.5% (40/170farms) and 7.5% (64/850heads), respectively. Seroprevalence of Holstein cattle was much higher than that of Hanwoo. In second stage positive rate of cow was 18.9% (246/1,303head), but seroprevalence of farm was very variable (1 - 90.5%). It was supposed that 3 farms with high positive rate had some risk factors to be infected; raising dogs in the same farm, location of hill-side where is easy to contact with wild animals.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제25권4호
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• pp.162-172
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• 2021

This paper proposes stochastic methods to find an approximate solution for the L²-Wasserstein least squares problem of Gaussian measures. The variable for the problem is in a set of positive definite matrices. The first proposed stochastic method is a type of classical stochastic gradient methods combined with projection and the second one is a type of variance reduced methods with projection. Their global convergence are analyzed by using the framework of proximal stochastic gradient methods. The convergence of the classical stochastic gradient method combined with projection is established by using diminishing learning rate rule in which the learning rate decreases as the epoch increases but that of the variance reduced method with projection can be established by using constant learning rate. The numerical results show that the present algorithms with a proper learning rate outperforms a gradient projection method.

• Journal of Advanced Marine Engineering and Technology
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• 제30권2호
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• pp.291-295
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• 2006

Recently, greenhouse effect by $CO_2$ gas emitted by use of fossil fuel causes earth environmental problem. As a countermeasure of the global warming. micro hydropower under 100kW becomes the focus of attention for its clean and renewable energy sources. Newly developed micro positive displacement hydraulic turbine shows high efficiency and good applicability for the micro hydropoewer. The purpose of this study is to clarify the influence of leakage loss and effective head on the performance of the positive displacement hydraulic turbine for the further improvement of the turbine performance. The results show that the turbine. with a smaller side clearance. has much higher efficiency than that with bigger side clearance and it can sustain the high efficiency under the wider range of operation conditions. The turbine torque is proportional to the effective head and independent of the flow rate. The leakage is also dependent on the effective head but nearly independent of the flow rate.

• 한국응용과학기술학회지
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• 제25권4호
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• pp.518-524
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• 2008

In this study, positive plates of lead acid battery of Pb-Ca alloy and Pb-Ca-Sn alloy were fabricated and the mechanical characteristics of positive plates were measured. This study observed how the changes of content of Ca & Sn affect interface corrosion which is located in between grid & active materials and lead acid batteries as well. The mechanical characteristics of grid alloy is better when Ca is 0.05 wt.% then 0.1 wt.%. This study said that the corrosion rate between the active material based on the charge/discharge cycle of lead acid battery and grid interface is much faster than a grid which contains Sn. And furthermore, according to the study the rate 30 of Sn/Ca which is added to grid shows the best performance.

• International Journal of Contents
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• 제14권4호
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• pp.1-9
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• 2018

This study evaluates the effectiveness of smartphone detox program for smartphone addiction among university students. To reduce the rate of smartphone addiction and its negative effects on physical, mental and social wellness, a six-session program was applied to sixteen participants who voluntarily completed the entire program and responded to pre-post survey. Smartphone Addiction Proneness Scale (SAPS) was used for smartphone addiction assessment with Mental Health Scale, Positive Psychological Capital Scale for mental wellness and Self-Management Scale for physical and social wellness. Results received after the program indicated that, smartphone addiction and mental health scores decreased significantly while the average scores of self-management and positive psychological capital increased respectively. Furthermore, the rate of high-risk group decreased, and the participants, affirmed in their self-evaluation report that excessive use of smartphone negatively affects their body, mind and interpersonal relationship. Thus, smartphone detox program is effective in reducing smartphone addiction and improving the students' wellness.