• Journal of Environmental Health Sciences
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• v.22 no.4
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• pp.122-128
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• 1996

Many computer programs have been developed for meteorological and air quality simulation. Many of the model the U.S. EPA recommends are available as. part of UNAMAP. HIWAY-II can be used to estimate the concentrations of nonreactive pollutants from highway traffic. As a result, It was found that distribution of concentration wind speed was 1 m/s to 5 m/s were diminished to about 1/2. In our study, we measured air pollutants(CO), temperature and humidity to evaluate. Meteorological parameter were influenced by not only wind direction but also vertical.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.4
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• pp.241-248
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• 2021

A battery state-of-health (SOH) estimation algorithm using a machine learning-based linear regression method is proposed for estimating battery aging. The proposed algorithm analyzes the change trend of the open-circuit voltage (OCV) curve, which is a parameter related to SOH. At this time, a section with high linearity of the SOH and OCV curves is selected and used for SOH estimation. The SOH of the aged battery is estimated according to the selected interval using a machine learning-based linear regression method. The performance of the proposed battery SOH estimation algorithm is verified through experiments and simulations using battery packs for electric vehicles.

• PNF and Movement
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• v.11 no.1
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• pp.63-68
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• 2013

Purpose : The purpose of this study was to examine changes in spatiotemporal gait parameters(STGPs) in healthy adults before and after a immediate intervention of a Mulligan taping program(MTP). Methods : A total of 12 healthy adults(mean age, 20.82 years; age range, 19-24 years) participated in the study. performance was assessed by recording changes in the STGPs using GaitRite. comparisons of changes in the STGPs at pre-intervention and at dischange were analyzed using the Wilcox signed rank test and Mann-Whithney U test. Results : There was a significant improvement in the outcome measures of STGPs(stride length, velocity) after immediate of MTP(p<0.05). However, no significant different pre-test and post-test step width, toe angle(p>0.05). Conclusion : Participants in a MTP improves STGPs, thereby increasing the ability of healthy adults to maintain gait. MTP appears to be a safe and efficacious, noninvasive treatment modality for patients with knee joint disease.

• The Journal of Korean Association of Computer Education
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• v.17 no.6
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• pp.147-159
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• 2014

This study aims to offer a wide range of practical implications for Smartphone addiction prevention by verifying the effect of mind health as a factor that is influenced by Smartphone addiction, and testing the relationships between Smartphone addiction and mind health with school life adaptation as a mediation effect. For this research, a survey was conducted of 250 elementary school students who use Smartphones. The relationships between Smartphone addiction, mind health and school life adaptation were set as the structural equation model, and they were verified by the mediation effect of school life adaptation. The results showed that school life adaptation turned out to be an entirely mediating variable on the relationship between mind health and Smartphone addiction. The statistical significance of the effect on school life adaptation was verified by the Sobel test. The mediation effect resulted in mind health reducing the occurrence of negative emotion of school life adaptation, and also reinforced decreased Smartphone use.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.5 no.2
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• pp.193-199
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• 1995

This study was designed to investigate the difference of time weighted average(TWA) of noise levels and noise doses by the different operating parameter settings such as exchange rate, threshold level and criterion level for noise dosimeter in the field measurements of noise at industrial working environments. The time weighted averages of noise level and noise doses for noise working environments were determined by noise dosimeter on 80 workers employed at 20 industrial establishments of 8 industries. The results obtained were as follows: 1. The mean time weighted average(TWA) of the noise working environments by the operating parameter settings showed 93.4 dB(A) in 3 dB of exchange rate, 80 dB of threshold level and 90dB of criterion level 92.0 dB(A) in 3 dB-exchange rate, 90 dB-threshold level and 90 dB-criterion level, in 90.8 dB(A) in 5 dB of exchange rate, 80 dB of threshold level and 90 dB of criterion level, and 86.7 dB(A) in 5 dB of exchange rate, 90 dB of threshold level and 90dB of criterion level. 2. ln group of noise level less than 90 dB(A), mean TWAs of 80 dB of threshold level were significantly higher than that of 90 dB of threshold level in 3 dB and 5 dB of exchange rate. 3. The case exceeded threshold limit value of noise was 49(61.3 %) in 3dB, 80dB and 90 dB setting, 44(55.0 %) in 3 dB, 90 dB, 90 dB setting, 33(41.3 %) in 5 dB, 80dB, 90 dB setting and 26(32.5%) in 5 dB, 90 dB, 90 dB setting. Above considerations in mind, it is suggested that exchange rate and threshold level be specified in related laws and regulations in the evaluation of working environments noise.

• Journal of radiological science and technology
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• v.40 no.2
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• pp.237-243
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• 2017

This study evaluated the applicability of computer-aided diagnosis by retrospective analysis of GLCM algorithm based on cytopathological diagnosis of normal and malignant nodules in thyroid ultrasound images. In the experiment, the recognition rate and ROC curve of thyroid malignant nodule were analyzed using 6 parameters of GLCM algorithm. Experimental results showed 97% energy, 93% contrast, 92% correlation, 92% homogeneity, 100% entropy and 100% variance. Statistical analysis showed that the area under the curve of each parameter was more than 0.947 (p = 0.001) in the ROC curve, which was significant in the recognition of thyroid malignant nodules. In the GLCM, the cut-off value of each parameter can be used to predict the disease through analysis of quantitative computer-aided diagnosis.

• Journal of Environmental Health Sciences
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• v.22 no.2
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• pp.90-95
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• 1996

This study was performed to calculate the degration rate coefficient, operating parameters to meet the effluent standards, and the temperature adjustment coefficients to each parameter of pollution by seasonal variation of concentration and temperature of influent in livestock wastewater treatment by sequencing batch reactor process in field scale. The followings are the conclusions that were derived from this study. 1. In the field, temperature of livestock wastewater in reactor was 20.3$\circ$C in summer and 6.0$\circ$C in winter. The ratio of BOD:TKN: T-P in influent was 100:80:7. BOD loadings in winter and spring were 0.26 and 0.43 kg $BOD/m^3$ day, respectively. Those in summer and fall were 0.25 and 0.13 kg $BOD/m^3$ day, respectively. 2. The degradation rate coefficient for TKN was larger in summer and fall in which temperature was high than that in which temperature was high than that in winter and spring in which concentration was high. On the contrary, the phosphorus uptake rate was larger in winter and spring than that in summer and fall. 3. The hydraulic retention time in winter and spring was longer than that in summer and fall. Especially, in order to meet the standard for TKN of 120 mg/l in winter in which temperature of wastewater was 6.0$\circ$C, as the MLSS concentration was increased from 4, 000 to 7, 000 mg/l, the hydraulic retention time was increased from 212 to 121 hours. But, in order to shorten that less than 121 hours for the economical wastewater treatment, countermeasure to increase temperature of wastewater in the reactor should be considered. 4. the temperature adjustment coefficients for BOD, $COD_{Mn}$, TKN and T-P were 1.0241, 1.0225, 1.0541 and 1.0495, respectively. Namely, the treatment of TKN was most sensitively affected by temperature. For the purpose of the effective removal of nitrogen and phosphorus which are sensitive to temperature, it is necessary to keep the temperature of livestock wastewater more than 20$\circ$C which is the temperature of it in summer.

• Journal of Korean society of Dental Hygiene
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• v.8 no.1
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• pp.133-146
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• 2008

Purpose: This research aims to investigate into company workers' awareness of scaling and related factors and provide basic materials for setting up appropriate policies to improve the hygiene of the mouth of industrial workers and developing training programs for the worker's hygiene of their mouth, as part of researches to establish schemes for improving the workers's hygiene of their mouth. Method: Questionnaire was conducted by convenience sampling for 220 office workers belonging to H Group located in Seoul Metropolitan city over about 5 weeks between December 17, 2007 and January 20, 2008. The questionnaire for this study was constructed in consideration of general characteristics of the subjects, behaviors of the dental management. and scaling. The collected questionnaires were electronically processed using SPSS 12.0. Result: The followings are the findings of this research. First, in general, scaling is experienced by male unmarried worker in their 40s. whose monthly average income is 1.00-1.99 million won and have little interest in the hygiene of their mouth and, consequently. whose hygiene of the mouth is not good. Second, scaling is experienced once every six months by the worker in their 50s or older, who are college graduates and have much interest in the hygiene of their mouth and, consequently. whose hygiene of the mouth is good. Third. scaling is not periodically conducted because of high costs of it in terms of almost every parameter of general characteristics. Fourth, they have correct knowledge of scaling since they regard it as 'removing of plaque and tartar' in terms of every parameter of general characteristics. Fifth, the workers' sex (pE0.05), hygienic condition of the mouth (pE0.05) and knowledge of scaling (pE0.001) have a significant effect on their scaling experience. Conclusion: It is considered that dental health management should be continued by training of the importance of prevention through scaling as measure for dental health promotion of workers.

• Smart Structures and Systems
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• v.21 no.5
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• pp.591-600
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• 2018

The probabilistic characterization of wind field characteristics is a significant task for fatigue reliability assessment of long-span railway bridges in wind-prone regions. In consideration of the effect of wind direction, the stochastic properties of wind field should be represented by a bivariate statistical model of wind speed and direction. This paper presents the construction of the bivariate model of wind speed and direction at the site of a railway arch bridge by use of the long-term structural health monitoring (SHM) data. The wind characteristics are derived by analyzing the real-time wind monitoring data, such as the mean wind speed and direction, turbulence intensity, turbulence integral scale, and power spectral density. A sequential quadratic programming (SQP) algorithm-based finite mixture modeling method is proposed to formulate the joint distribution model of wind speed and direction. For the probability density function (PDF) of wind speed, a double-parameter Weibull distribution function is utilized, and a von Mises distribution function is applied to represent the PDF of wind direction. The SQP algorithm with multi-start points is used to estimate the parameters in the bivariate model, namely Weibull-von Mises mixture model. One-year wind monitoring data are selected to validate the effectiveness of the proposed modeling method. The optimal model is jointly evaluated by the Bayesian information criterion (BIC) and coefficient of determination, $R^2$. The obtained results indicate that the proposed SQP algorithm-based finite mixture modeling method can effectively establish the bivariate model of wind speed and direction. The established bivariate model of wind speed and direction will facilitate the wind-induced fatigue reliability assessment of long-span bridges.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.1829-1831
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• 2012

Background: The generalized gamma distribution statistics constitute an extensive family that contains nearly all of the most commonly used distributions including the exponential, Weibull and log normal. A saturated version of the model allows covariates having effects through all the parameters of survival time distribution. Accelerated failure-time models assume that only one parameter of the distribution depends on the covariates. Methods: We fitted both the conventional GG model and the saturated form for each of its members including the Weibull and lognormal distribution; and compared them using likelihood ratios. To compare the selected parameter distribution with log logistic distribution which is a famous distribution in survival analysis that is not included in generalized gamma family, we used the Akaike information criterion (AIC; r=l(b)-2p). All models were fitted using data for 369 women age 50 years or more, diagnosed with stage IV breast cancer in BC during 1990-1999 and followed to 2010. Results: In both conventional and saturated parametric models, the lognormal was the best candidate among the GG family members; also, the lognormal fitted better than log-logistic distribution. By the conventional GG model, the variables "surgery", "radiotherapy", "hormone therapy", "erposneg" and interaction between "hormone therapy" and "erposneg" are significant. In the AFT model, we estimated the relative time for these variables. By the saturated GG model, similar significant variables are selected. Estimating the relative times in different percentiles of extended model illustrate the pattern in which the relative survival time change during the time. Conclusions: The advantage of using the generalized gamma distribution is that it facilitates estimating a model with improved fit over the standard Weibull or lognormal distributions. Alternatively, the generalized F family of distributions might be considered, of which the generalized gamma distribution is a member and also includes the commonly used log-logistic distribution.