• Journal of Environmental Science International
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• v.16 no.10
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• pp.1157-1167
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• 2007

In an effort to interpret the characteristics of fine particle concentrations in Busan, time variations of hourly monitored concentrations $PM_{10}$ (Particulate Matter with aerodynamic Diameter ${\le}10\;{\mu}m$) in Busan are analyzed for the period from 2000 to 2005. The characteristics of aerosol second generation formation process is also interpreted qualitatively, by using the statistical analysis of the meteorological variables including temperature, wind speed, and relative humidity. The result shows some significant annual, seasonal, weekly and diurnal variations of $PM_{10}$ concentrations. In particular, seasonal(i.e., spring) variations are governed by frequency of yellow sand events even for the non-yellow sand cases where yellow-sand days are eliminated in our analysis. However, in seasonal variation, summer season predominate lower $PM_{10}$ concentrations due to the frequent precipitation, and weekly and diurnal variations are both found to be reflecting the emission rate from traffic amount. Correlation coefficients between $PM_{10}$ concentration and meterological variables for non-yellow sand days show overall negative correlation with visibility, wind speed, cloud amounts, and relative humidity. However for non-precipitation days, during non-yellow sand period positive correlation are found clearly with relative humidity, suggesting the importance of secondary aerosol formation in Busan that can be achieved by both homogeneous aerosol formation and heterogeneous transformations resulting from hygroscopic aerosol characteristics.

• Journal of Technologic Dentistry
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• v.37 no.3
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• pp.169-178
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• 2015

Purpose: This study was to investigate usage satisfaction of multi type handpiece with equipped air-jet function Methods: The subjects of this study through the survey was conducted for fifty-nine dental technicians in Daegu and Gyeongsangbukdo from the May 7 to 19, after the June 23 to July 4 2014. The survey was about the function and quality through user testing environment by cutting zirconia specimens using appliance for zirconia. The collected date was analyzed by the statistical program SPSS Win Ver 19.0 for the satisfaction of handpiece and control system. To test for significance on each item, p<0.05 had been decided a standard. General characteristics and relationship between the handpiece and control system was performed correlation analysis. Results: The results of this study is as follows. 35 dental technicians had 1~2 years career in zirconia part as the highest 59.3%, 95% of subjects expected that the prospects for the zirconia material have bright prospects. The satisfaction of multi type handpiece and control system design and function showed a significant difference. Subjects satisfied with the design and function of the multi type showed negative correlation with those of Standard. The satisfaction of multi type handpiece showed 3.37 points of air jet, 3.05 points of noise level, 2.69 points of water flow rate, and 1.98 points of cruise function. Sample differences in all parameters showed a statistically higher difference. Conclusion: High-speed cutting mechanism of multi-type is recommended working with zirconia materials and the multi-type unit combined handpiece motor, air-turbine and air-gun will be expected the increase of user due to the high satisfaction of air jet.

• Korean Journal of Biological Psychiatry
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• v.21 no.4
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• pp.151-160
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• 2014

Objectives Prenatal testosterone is known to influence both cerebral laterality and 2nd to 4th digit ratio (2D : 4D). Epigenetic changes are thought to play some role in it. We studied sex-related differences between 2D : 4D and cerebral laterality in patients with schizophrenia and controls to examine the effects of prenatal testosterone in the development of schizophrenia. Methods Forty one men (18 schizophrenic patients and 23 controls) and 40 women (17 schizophrenic patients and 23 controls) were recruited from one psychiatric hospital in Korea. The 2D : 4D and electroencephalographic (EEG) coherence in 19 channels (66 pairs of interhemispheric coherence and 54 pairs of intrahemispheric coherence) were measured. The sex-related statistical analyses between 2D : 4D and EEG coherence in controls and patients with schizophrenia were performed using multiple regression. Results In male patients, the relationship between 2D : 4D and right intrahemispheric EEG coherence showed mainly positive correlation in delta and theta frequency bands, while it showed negative correlation in male controls. In female patients, the relationship between 2D : 4D and interhemispheric EEG coherence showed stronger positive correlation in alpha and beta frequency bands, while it showed weaker positive correlation in female controls. Conclusions Low prenatal testosterone may play certain roles in altered correlation between 2D : 4D and cerebral laterality in schizophrenia and the development of schizophrenia by epigenetic mechanism.

• Journal of Korean Academy of Nursing
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• v.35 no.7
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• pp.1295-1303
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• 2005

Purpose: This study was to determine the effects of abdominal breathing training using biofeedback on stress, immune response, and quality of life. Method: The study design was a nonequivalent control group pretest-posttest, quasi-experimental design. Twenty-five breast cancer patients who had completed adjuvant chemotherapy were enrolled. The experimental group(n=12) was provided with abdominal breathing training using biofeedback once a week for 4 weeks. State anxiety, cancer physical symptoms, serum cortisol, T cell subsets(T3, T4, T8), NK cell and quality of life were measured both before and after the intervention. Result: Though state anxiety, cancer physical symptoms, and serum cortisol were reduced after 4 weeks of abdominal breathing training using biofeedback, there was no statistical significance. It showed, however, improvement in quality of life (p=.02), and T3(p=.04). Conclusion: Abdominal breathing training using biofeedback improves quality of life in breast cancer patients after a mastectomy. However, the mechanism of this beneficial effect and stress response requires further investigation with special consideration in subject selection and frequency of measurement. Nurses should consider this strategy as a standard nursing intervention for people living with cancer.

• The Journal of Advanced Prosthodontics
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• v.7 no.2
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• pp.98-107
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• 2015

PURPOSE. The aim of this study was to appraise the some mechanical properties of polymethyl methacrylate based denture base resin polymerized by copolymerization mechanism, and to investigate the cytotoxic effect of these copolymer resins. MATERIALS AND METHODS. 2-hydroxyethyl methacrylate (HEMA) and isobutyl methacrylate (IBMA) were added to monomers of conventional heat polymerized and injection-molded poly methyl methacrylate (PMMA) resin contents of 2%, 3%, and 5% by volume and polymerization was carried out. Three-point bending test was performed to detect flexural strength and the elasticity modulus of the resins. To determine the statistical differences between the study groups, the Kruskall-Wallis test was performed. Then pairwise comparisons were performed between significant groups by Mann-Whitney U test. Agar-overlay test was performed to determine cytotoxic effect of copolymer resins. Chemical analysis was determined by FTIR spectrum. RESULTS. Synthesis of the copolymer was approved by FTIR spectroscopy. Within the conventional heat-polymerized group maximum transverse strength had been seen in the HEMA 2% concentration; however, when the concentration ratio increased, the strength decreased. In the injection-molded group, maximum transverse strength had been seen in the IBMA 2% concentration; also as the concentration ratio increased, the strength decreased. Only IBMA showed no cytotoxic effect at low concentrations when both two polymerization methods applied while HEMA showed cytotoxic effect in the injection-molded resins. CONCLUSION. Within the limitations of this study, it may be concluded that IBMA and HEMA may be used in low concentration and at high temperature to obtain non-cytotoxic and durable copolymer structure.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1710-1715
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• 2010

Service life of water pipes buried in the underground is considerably affected from various factors such as environmental characteristics, pipe characteristics, operation and maintenance, etc. Therefore it is difficult to determine their service life as uniformly the same value assigned by related laws and ordinances. As a result, the service life should be determined by the technical judgement based on the assessment for the condition of water pipes. In this study, It was established that the methodology could predict present and future failure risk, and plan short and long-term strategies for replacement/rehabilitation through the assessment for the physical deterioration and economical values of buried water pipe. The methodology was applied for the verification and reliability to several sites selected in multi-regional transmission pipelines. The proposed method could helps to support reasonable and economical decision of rehabilitation/replacement in the present and future. To improve conventional assessment method of aged water pipes, affecting factors are simplified based on the statistical analysis results from the measured data in the field and the physical deterioration mechanism for better reliability. Also, the guide-line is developed to carry out the reasonal rehabilitation planning through water pipe condition assessment.

• Journal of the Korean Data and Information Science Society
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• v.22 no.6
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• pp.1017-1028
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• 2011

When it is not easy to decide the credit scoring for some loan applicants, credit evaluation is postponded and reserve to ask a specialist for further evaluation of undecided applicants. This undecided inference is one of problems that happen to most statistical models including the biostatistics and sportal statistics as well as credit evaluation area. In this work, the undecided inference is regarded as a missing data mechanism under the assumption of MNAR, and use the bivariate probit model which is one of sample selection models. Two undecided inference methods are proposed: one is to make use of characteristic variables to represent the state for decided applicants, and the other is that more accurate and additional informations are collected and apply these new variables. With an illustrated example, misclassification error rates for undecided and overall applicants are obtainded and compared according to various characteristic variables, undecided intervals, and thresholds. It is found that misclassification error rates could be reduced when the undecided interval is increased and more accurate information is put to model, since more accurate situation of decided applications are reflected in the bivariate probit model.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.6
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• pp.1241-1246
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• 2009

It has been suggested that Tae-Eum peoples are prone to obesity. Although extensive clinical observations have shown this tendency in Sasang Constitutional Medicine (SCM), no scientific hypothesis has been proposed to delineate its mechanism. According to SCM theory, Tae-Eum peoples have a hypoactive lung system and a hyperactive liver system. In this paper we propose a new hypothesis explaining the tendency of obesity in Tae-Eum people in the viewpoint of cell physiology. The hypoactive lung system might imply an attenuated 'respiration' at the cell/subcell level, namely mitochondrial oxygen consumption. Because a functional weakness in mitochondria energy metabolism indicates intrinsic hypo-activity in the consumption (or production) of metabolic energy, we deduced that the tendency can easily induce body weight gain via an increase in anabolism. This relation is also introduced in the graph of cellular metabolic power against body weight. To test this hypothesis, we analyzed the clinical data with 863 subjects. Statistical analysis of the data showed that Tae-Eum peoples had relatively a lower cellular metabolic power, and that the percentage of peoples with BMI>25 was significantly higher than that of the other constitutional types.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.4
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• pp.24-33
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• 2001

The purpose of this paper is to examine the differences of user´s satisfaction of development elements of natural recreation forest(NFR) developed by public and private bodies in order to answer the research question: What is the differences of user´s satisfaction of development elements of NFR\ulcorner After reviewing the literature, mechanism of outdoor recreation, and development elements in NRF, we constructed the conceptual framework and have formulated the hypothesis of this research. We had obtained data through a questionnaire, which surveyed 584 visitors at 10 of the 72 natural recreation forests in Korea in 1999. We have analyzed the data using he descriptive statistical method, the mean difference test, and logistic regression method. We have found that 1) all the development elements have turned out to be significantly different from the mean difference test, 2) the two elements of atmosphere and activity have turned out to be statistically significant in determining the difference of NFR developed by public and private body in logistic regression analysis while user´s satisfaction in recreational resources, facilities and service make no differences between public and private NRF, 3) the higher the degree of user´s satisfaction in atmosphere and activity at NFR, the more the NFR developed by private body, and 4) their relative contribution of atmosphere and activities on whether the NFR is developed by public or private body have been turned out to have 0.258 and 0.242 respectively, which have a similar importance. The research results suggest that a guideline for the creation of marketable NFR by public and private developer, and development of use-programs and recreational atmosphere be recommended in the planning and development process of NRF. The approach and anlaysis method adopted by this research is highly useful for an evaluation of NRF developed by the tow bodies and development of devices for increasing user´s satisfaction and marketing positioning of NRF by the tow developers. It is recommended that more empirical study on individual development elements affecting user´s satisfaction be performed in the future.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.391-396
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• 2005

Red tide(harmful algae) in the Korean Coastal Waters has a given a great damage to the fishery every year. However, the aim of our study understands the influence of meteorological factors (air and water tempaerature, precipitation, sunshine, solar radiation, winds) relating to the mechanism of red tide occurrence and monitors red tide by satellite remote sensing, and analyzes the potential area for red tide occurrence by GIS. The meteorological factors have directly influenced on red tide formation. Thus, We want to predict and apply to red tide formation from statistical analyses on the relationships between red tide formation and meteorological factors. In future, it should be realized the near real time monitoring for red tide by the development of remote sensing technique and the construction of integrated model by the red tide information management system (the data base of red tide - meteorological informations).