• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.4 no.2
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• pp.208-223
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• 1994

The purpose of this study was to evaluate the efficiency of diffusive(or passive) sampler in measuring airbone organic solvents. Diffusive samplers are generally simple in construction and do not require power for operation. The efficiency of the diffusive samplers has not sufficiently been investigated in Korea. Three types of samplers were studied in this study. The sampling and analytical results by passive samplers were compared with results by charcoal tube method recommended by NIOSH(National Institute for Occupational Safty and Health). The following characteristics are identified and studied as critical to the performance passive monitors; recovery, reverse diffusion, storage stability, accuracy and precision, face velocity and humidity, n-Hexane, TCE(trichloroethylene) and toluene were used as test vapors. A dynamic vapor exposure system consisting of organic vapor generator and sampling chamber for evaluating diffusive samplers are made. The results of the study are summarized as follows. 1. NIOSH recommands that the overall accuracy of a sampling method in the range of 0.5 to 2.0 times the occupational health standard should be ${\pm}25$ percent for 95 percent confidence level. Among three types of diffusive samplers, sampler A has permeation membrane and samplers Band C have diffusive areas, samplers A and B met the criterion that overall accuracy for 95% confidence level of the samplers were within ${\pm}25$ percent of the reference value. Sampler C had overall accuracy ${\pm}9.6%$ and ${\pm}11.8%$ in hexane and TCE, respectively. The concentration of toluene was overestimated in sampler C with overall accuracy of ${\pm}43.9%$. 2. The desorption efficiencies of diffusive samplers were 96-107%. 3. There was no significant sampe loss during four weeks of storage both with and without refrigeration. 4. There was no significant reverse diffusion, when the samplers were exposure to clean air for 2 hours after sampling for 2 hours at the level of 2 TLY. 5. In case of 8 hours sampling, relative differences(RD) of concentrations between charcoal tube method and diffusive method were 15-39%, 13-46%, and 4-35% for sampler A, B and C, respectively. The performance was poor in 8 hours sampling for multiple substance monitors. 6. At high velocity(100 cm/sec), samplers B and C overestimated the concentrations of organic vapors, and sampler A with permeation membrance gave better results. 7. At 80% relative humidity, samplers showed no siginificant effect. Low humidity also did not affect the diffusive samplers.

• Journal of Korean Academy of Nursing
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• v.17 no.3
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• pp.218-226
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• 1987

This descriptive-correlational study was undertaken in order to examine if there were relationships between family support, compliance and life satisfaction in chronic arthritis patients. The sampling method was a non-probability, purposive sampling technique. The participants of this study were 92 volunteer adults. 1) who have been diagnosed as having chronic arthritis and 2) who were at the medical out patient clinic of one university hospital in Seoul between April 27th to May 12th 1987. The instruments used for this study were the Family Support Scale developed by Kang Hyun Sook, a Compilance Scale developed by the researcher and the Life-Satisfaction Index-Z developed by Wood et.al. Analysis of data was done using t-test, ANOVA, Pearson Correlation Coefficient and Stepwise Multiple Regression Analysis. The results of study were as follows; Hypothesis I; “The higher the family support, the higher the compliance” was accepted. (r＝.2604, p＜.01) Hypothesis II; “The higher the compliance, the higher the life satisfaction,” was rejected. (r＝.1663, p＞0.5) Hypothesis III; “The higher the family support, the higher the life satisfaction” was accepted. (r＝.3914, p＜.01) In addition, by using Stepwise Multiple Regression Analysis it was determined that the main influencing factors on the life satisfaction were family support, the number of inflammatory joints, compliance and pain level. These 4 main variables made it possible to explain 30.8% of the variance in life satisfaction. In conclusion, this study revealed that family support is an important factor that can improve compliance and life satisfaction in chronic arthritis patients.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.2
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• pp.1017-1023
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• 2021

This research aims to determine the effect of customers' threat emotion and price on the decision to purchase a certain smartphone product. This study uses a quantitative method with a type of descriptive and causal research. It employs non-probability sampling with purposive sampling, with 385 respondents to answer the questionnaires. Data analysis techniques used descriptive analysis and multiple linear regression analysis. Based on the results of descriptive analysis of emotion, price and purchasing decisions are in sync with each other. The results of multiple linear regression analysis techniques indicate the threat emotion and brand trust are influential against the positive decision to purchase smartphone products. The magnitude of the influence of emotions and price have simultaneous effect on purchasing decisions and other decision variables, which are not included in this study, also play minor role in determining purchase intention, such as product quality, brand image and others. Partially, threat emotion and brand trust have a positive effect toward purchasing decisions. The magnitude of the highest influence was the one of price, then followed by emotional threats. The findings of this study suggest that psychological and behavioral effects also play important roles in determining customers' purchase decision.

• Communications for Statistical Applications and Methods
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• v.29 no.2
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• pp.239-250
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• 2022

In many applications, we frequently encounter correlated multiple outcomes measured on the same subject. Joint modeling of such multiple outcomes can improve efficiency of inference compared to independent modeling. For instance, in developmental toxicity studies, fetal weight and number of malformed pups are measured on the pregnant dams exposed to different levels of a toxic substance, in which the association between such outcomes should be taken into account in the model. The number of malformations may possibly have many zeros, which should be analyzed via zero-inflated count models. Motivated by applications in developmental toxicity studies, we propose a Bayesian joint modeling framework for continuous and count outcomes with excess zeros. In our model, zero-inflated Poisson (ZIP) regression model would be used to describe count data, and a subject-specific random effects would account for the correlation across the two outcomes. We implement a Bayesian approach using MCMC procedure with data augmentation method and adaptive rejection sampling. We apply our proposed model to dose-response analysis in a developmental toxicity study to estimate the benchmark dose in a risk assessment.

• The KSFM Journal of Fluid Machinery
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• v.11 no.1
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• pp.52-60
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• 2008

Staggered dimples printed on opposite walls of an internal cooling channel are formulated numerically and optimized to enhance heat transfer performance. Nusselt number and friction factor based objectives are considered and a weighted average surrogate model is used to approximate the data generated by numerical simulation. The dimpled channel shape is defined by three geometric design variables, and the design point within design space are selected using Latin hypercube sampling. A weighted-sum method for multi-objective optimization is applied to integrate multiple objectives into a single objective. By the optimization, the objective function value is improved largely and heat transfer rate is increase much higher than pressure loss increase due to shape deformation. Channel with vertically non-symmetric optimum dimples is tested and found that the best appears if dimples on opposite wall are displaced by one quarter of dimple spacing.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.679-680
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• 2006

이 논문에서는 가장 많이 알려진 tracking 알고리즘인 Particle-Filter 의 단점을 motion vector 를 기반으로 예측한 sampling 방법과 K-means clustering 을 이용하여 해결하려고 한다. Tracking 에서의 문제는 다중의 유사한 객체들이 merge 후 split 될 때 제대로 추적을 하지 못하고 한 객체만을 추적 한다는 데에 있었다. 그리고 split 되어 객체별로 추적이 가능하더라도 이전에 추적한 객체를 올바로 labeling 하지 못하는 문제가 있다는 것이다. 이 merge-split 문제는 개량된 K-means clustering 을 이용하고, labeling 문제는 motion vector 를 이용한 개량된 sampling 방법으로 개선하였다.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.12
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• pp.433-444
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• 2020

The purpose of this study is to analyze integrated reporting disclosure and its implications on investor reactions. The population in this study is all manufacturing companies listed on the Indonesia stock exchange from 2017 to 2019, totaling 171 companies, and the sampling technique used is purposive sampling method. The method used in this research is a quantitative description using the financial statements of manufacturing companies listed on the Indonesia stock exchange. The data analysis method used is multiple regression analysis with intervening variables using AMOS 24 software. The results of this study show a positive and significant effect of profitability (X1) and company size (X2) on integrated reporting (IR); a positive and insignificant effect of stakeholder pressure (X3) on integrated reporting (IR); a positive and significant effect of profitability (X1) and stakeholder pressure (X3) on investor reactions (Y); a positive and insignificant effect of firm size (X2) and integrated reporting (IR) on investor reactions (Y). Suggestions are that in further studies, we can increase the sample size by including other industries, and in addition to using annual reporting, we can also use other sources such as websites, press releases, and prospectuses to improve the robustness of this study by relying on other data sources.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.6
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• pp.2289-2301
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• 2015

Mobile devices are becoming powerful enough to realize augmented reality (AR) application. This paper introduces two AR methods to estimate an environmental illumination distribution of a scene. In the first method, we extract the lighting direction and intensity from input images captured with a front-side camera of a mobile device, using its orientation sensor. The second method extracts shadow regions cast by three dimensional (3D) AR marker of known shape and size. Because previous methods examine per pixel shadow intensity, their performances are much affected by the number of sampling points, positions, and threshold values. By using a simple binary operation between the previously clustered shadow regions and the threshold real shadow regions, we can compute efficiently their relative area proportions according to threshold values. This area-based method can overcome point sampling problem and threshold value selection. Experiment results demonstrate that the proposed methods generate natural image with multiple smooth shadows in real-time.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.11
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• pp.335-346
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• 2020

This study aims to describe the role of corporate governance as a moderator in electronic financial disclosure that adopts Extensible Business Reporting Language (XBRL) and Company Characteristics on value relevance. The population in this study was all manufacturing companies listed on the Indonesia Stock Exchange from 2017 to 2018, totaling 166 companies. The sampling technique used purposive sampling method, namely, manufacturing companies that publish fully audited financial statements by December 31 of the year 2017-2018. The method used in this research is a quantitative description using the financial statements of manufacturing companies listed on the Indonesia Stock Exchange that have adopted XBRL during the 2017-2018 period. The data analysis method used is multiple regression analysis with moderating variables. The results of this study show a negative and insignificant effect of XBRL on value relevance, a significant negative effect of size on value relevance, a positive and insignificant effect of growth on value relevance, and a significant positive effect of profit on value relevance; meanwhile, corporate governance moderation variable has an insignificant effect in all hypotheses. Suggestions are to increase the number of variables that have an important role in value relevance and expand the number of research objects to be compared.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.6
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• pp.899-905
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• 2013

In this paper, we focus on how to calibrate multi-cameras easily and how to efficiently detect quad-copters with small-numbered particles. Each particle is a six dimensional vector that is composed of 3D position and 3D orientation of a quad-copter in the space. Due to curse of dimensionality, that leads to explosive computational costs with a large amount of high-dimensioned particles. To detect efficiently, we need to put more particles in very promising spaces and few particles in other spaces. Though computational cost is lowered by minimizing particles, in order to track a quad-copter with multiple cameras in real-time, multiple images from the cameras should be synchronized and analyzed. Therefore, lots of the computations still need to be done. Because of this, GPGPU(General-Purpose computing on Graphics Processing Units) is implemented for parallel computing. This method has been successfully tested and gives accurate results in practical situations.