• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.1
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• pp.29-38
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• 2012

The noise generated in the process of obtaining the medical image acts as the element obstructing the image interpretation and diagnosis. To restore the true image from the image polluted from the noise, the total variation optimization algorithm was proposed by the R.O. F (L.Rudin, S Osher, E. Fatemi). This method removes the noise by fitting the balance of the regularity and fidelity. However, the blurring phenomenon of the border area generated in the process of performing the iterative operation cannot be avoided. In this paper, we propose the adaptive total variation method by mapping the control parameter to the proposed transfer function for minimizing boundary error. The proposed transfer function is determined by the noise variance and the local property of the image. The proposed method was applied to 464 tooth images. To evaluate proposed method performance, PSNR which is a indicator of signal and noise's signal power ratio was used. The experimental results show that the proposed method has better performance than other methods.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.7
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• pp.380-394
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• 2015

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

• Journal of Digital Convergence
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• v.15 no.3
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• pp.9-16
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• 2017

Organizational culture provides organizational members with identity, homogeneity and behavioral guidance, and promotes organizational commitment and enhances the stability of social systems. What organizational culture positively influences organizational performance? In this study, we tried to categorize organizational culture as creativity, change, cooperation, trust and knowledge sharing for specific public institutions and to diagnose the organizational culture by examining the level of recognition of the organizational members. The purpose of this study is to investigate the effect of organizational culture on organizational culture. The result of this study shows that the degree of future - oriented and cooperative culture of the public institutions that are the subject of research is not so high. In order to improve the performance of the organization, it is necessary to create a futuristic and cooperative culture. In order to create such a culture, various efforts must be made to continuously communicate and build trust among the members of the organization. In particular, leadership efforts to distribute, transfer, and trust authority to subordinates are a priority. In other words, it is very difficult to build a future-oriented, collaborative culture successfully without the efforts of managers.

• Journal of Digital Convergence
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• v.14 no.6
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• pp.219-235
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• 2016

This study was performed to study the factors appear to SMEs and how differently depending on the worker ranks at the convergence age. Additionally, numerous studies and results on the factors which affect the organization's performance was to individually different approach to integrated. Especially venture was divided by a factor of enterprises and transformational dynamics factors and commutative Dynamics factors and approaches in terms of the impact transformative dynamics of which factors are organizational commitment and job satisfaction. A transformational dynamism to the four factors were such as mission and strategy, CEO Leadership, Manager, leadership, organizational culture variables. The study was based on theoretical models of organizational development, Burke and Litwin (1992). They were classified as managers and production workers. By obtaining data from employees 630 people engaged in a total of nine manufacturers were analyzed. The average variable based on the organization's Burke and Litwin (1992) theory of transformational variables is one that Nana was aware of the organizational commitment, and job satisfaction. Correlation analysis transformational dynamics variables're having an impact on job satisfaction and organizational commitment, job position is found to have moderating effects.

• Journal of the Microelectronics and Packaging Society
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• v.31 no.2
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• pp.28-35
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• 2024

Corrosion inside electronic packages significantly impacts the system performance and reliability, necessitating non-destructive diagnostic techniques for system health management. This study aims to present a non-destructive method for assessing corrosion in copper interconnects using the Smith chart, a tool that integrates the magnitude and phase of complex impedance for visualization. For the experiment, specimens simulating copper transmission lines were subjected to temperature and humidity cycles according to the MIL-STD-810G standard to induce corrosion. The corrosion level of the specimen was quantitatively assessed and labeled based on color changes in the R channel. S-parameters and Smith charts with progressing corrosion stages showed unique patterns corresponding to five levels of corrosion, confirming the effectiveness of the Smith chart as a tool for corrosion assessment. Furthermore, by employing data augmentation, 4,444 Smith charts representing various corrosion levels were obtained, and artificial intelligence models were trained to output the corrosion stages of copper interconnects based on the input Smith charts. Among image classification-specialized CNN and Transformer models, the ConvNeXt model achieved the highest diagnostic performance with an accuracy of 89.4%. When diagnosing the corrosion using the Smith chart, it is possible to perform a non-destructive evaluation using electronic signals. Additionally, by integrating and visualizing signal magnitude and phase information, it is expected to perform an intuitive and noise-robust diagnosis.

• Journal of Korea Society of Industrial Information Systems
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• v.28 no.2
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• pp.1-9
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• 2023

Research using AI and big data is also being actively conducted in the health and medical fields such as disease diagnosis and treatment. Most of the existing research data used cohort data from research institutes or some patient data. In this paper, the difference in the prediction rate of survival and the factors affecting survival between breast cancer patients in their 40~50s and other age groups was revealed using health insurance review claim data held by the HIRA. As a result, the accuracy of predicting patients' survival was 0.93 on average in their 40~50s, higher than 0.86 in their 60~80s. In terms of that factor, the number of treatments was high for those in their 40~50s, and age was high for those in their 60~80s. Performance comparison with previous studies, the average precision was 0.90, which was higher than 0.81 of the existing paper. As a result of performance comparison by applied algorithm, the overall average precision of Decision Tree, Random Forest, and Gradient Boosting was 0.90, and the recall was 1.0, and the precision of multi-layer perceptrons was 0.89, and the recall was 1.0. I hope that more research will be conducted using machine learning automation(Auto ML) tools for non-professionals to enhance the use of the value for health insurance review claim data held by the HIRA.

• Journal of the Korea Society of Computer and Information
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• v.27 no.12
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• pp.29-40
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• 2022

In this paper, we studied a system that detects and analyzes the pathological features of diabetic retinopathy using Mask R-CNN and a Random Forest classifier. Those are one of the deep learning techniques and automatically diagnoses diabetic retinopathy. Diabetic retinopathy can be diagnosed through fundus images taken with special equipment. Brightness, color tone, and contrast may vary depending on the device. Research and development of an automatic diagnosis system using artificial intelligence to help ophthalmologists make medical judgments possible. This system detects pathological features such as microvascular perfusion and retinal hemorrhage using the Mask R-CNN technique. It also diagnoses normal and abnormal conditions of the eye by using a Random Forest classifier after pre-processing. In order to improve the detection performance of the Mask R-CNN algorithm, image augmentation was performed and learning procedure was conducted. Dice similarity coefficients and mean accuracy were used as evaluation indicators to measure detection accuracy. The Faster R-CNN method was used as a control group, and the detection performance of the Mask R-CNN method through this study showed an average of 90% accuracy through Dice coefficients. In the case of mean accuracy it showed 91% accuracy. When diabetic retinopathy was diagnosed by learning a Random Forest classifier based on the detected pathological symptoms, the accuracy was 99%.

• Research in Community and Public Health Nursing
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• v.5 no.1
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• pp.64-80
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• 1994

The purpose of this study was to identify factors affecting family caregiver burden, and to identify the relationship between family caregiver burden and family function /self-care of psychiatric out-patient. These data were collected by questionnaire from September 20 to October 8, 1993. The subjects were 285 family caregiver of psychiatric out-patients. The instruments used in this study were Caregiver Burden Inventory(CBI) by Novak(1989), self-care performing by Yu(1992), and Family APGAR by Smilkstein(1979). The data were analyzed by cronbach's $\alpha$, mean, standard deviation, percentage, t-test, ANOVA, Pearson's correlation coefficient, and Stepwise Multiple Regression with SPSS /pc+ program. The result of this study were as follows ; 1. The means of family caregiver Burden revealed total 2.00, Time-Dependence Burden 78, developmental Burden 2.22, physical Burden 1.90, social Burden 1.43, emotional Burden 2.18, financial Burden 1.51. family caregiver burden score showed moderate level. time-dependence burden showed the highest score and social burden showed the lowest score. 2. The means of family function revealed total 5.67. 7 through high-21.4% (61), low through 3-38.6%(110). family function score showed moderate level. 3. The means of patient's self-care performance revealed total 137.71. self-care performance showed moderate level. 4. A ststistically significant correlation between family caregiver burden and patient's demographic variables, age (F=3.83, p<.01), marrital status(F=3.50, p<.01), job(F=3.17, p<.01), diagnosis(F=4.46, p<.01), income (F=4.46, p<.01). No significant differences between family caregiver burden and prevalent period, religion, sex (p>.05). S. A ststistically significant correlation between family caregiver burden and family's demographic variables, age (F=7.34, p<.01), sex(t=-2.63, p<.01), education level(F=7.61, p<.01), income (F=8.13, p<.01), relation with patient (F=6.92, p<.01), job(F=2.03, p<.05), medical service (F=3.89, p<.05), presence of chronically ill without patient(t=-2.01, p<.05) 6. Family function was the highest factor predicting family caregiver burden(R=.4168, $R^2=.1737$), low education level of family, patient's self-care, family income accounted for 36% in family caregiver burden.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.121-125
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• 2011

Purpose: The DNA-type virus HBV, discovered by D. Dane and others in 1976, is approximately 42nm big and known as the main cause of liver-related diseases around the world. HBsAg has 4 kinds of subtypes including adw, adr, ayw and ayr and besides common antigen factor a, there are d, y, r, w. From the methods of serologically testing HBV, IRMA, EIA and CLIa were developed for testing HBsAg and are being used in examining the surface antigen of HBV. In this study, among the methods for testing HBV, the recently developed RIAKEY Ultrasensitive HBsAg IRMA kit's sensitivity level and performance in detection of mutant forms were measured and compared with CLIA. Materials and methods: Two certified reference materials, which are WHO 1st International Standard 1985(80/549) and WHO 2nd International Standard 2003(00/588. subtype adw2, genotypeA), were used in the examination and the sensitivity level was measured by diluting these materials from 0.08 IU/ml to 0.005 IU/ml. The materials for examining the detection of mutant forms included 9 kinds of subtype 'ad' and one kind of subtype 'ay' purchased from DSI company. Also, with the use of positive and negative samples, they was compared with CLIA. Result: Ultrasensitive HBsAg kit based on IRMA method showed the detection of up to 0.01 IU/ml not only for WHO 1st International Standard 1985(80/549) but also for WHO 2nd International Standard 2003(00/588. subtype adw2, genotypeA) and the sensitivity level was measured as 0.01 IU/ml by WHO standard. In testing the performance for detection of mutant forms, the 9 kinds of subtype 'ad' and one kind of subtype 'ay' mutant materials were detected, demonstrating the capacity of detecting various types of mutant forms. Conclusions: With the clinical importance of sensitivity level and performance in detection of mutant forms increasing in the field of HBsAg diagnosis, the examination of IRMA's effectiveness using RIA method in the aspects of the sensitivity level and performance in detection of mutant forms was carried out and its result is as follows. The sensitivity level was measured as 0.01 IU/ml by WHO standard and it was possible to measure various types of mutant forms with high sensitivity. Thus it is suggested that more speedy and accurate reports could be produced from a nuclear medicine laboratory for clinical practitioners requiring results of various situations.

• Journal of Practical Engineering Education
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• v.15 no.3
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• pp.605-614
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• 2023

In In the era of digital transition, AI-based personalized services are emerging in the field of education. This research aims to examine the development strategies for implementing AI-based learning services in school. Focusing on AI-based math learning service "Math Cell" developed by i-Scream Edu, this study surveyed the functional requirements from the perspective of an educator. The results were analyzed for importance and suitability using IPA, and expert opinions were surveyed to explore specific development directions for the service. Consequently, importance in all areas such as diagnosis, learning, evaluation, and management averaged 4.82 and performance averaged 4.56, showing excellent results in most questions, and in particular, importance was higher than performance. Among certain detailed functions, concept learning, customized task presentation, evaluation result analysis function, dashboard-related functions, and learning materials in the dashboard were not intuitive for students to understand and had to be supplemented. This study provides meaningful insights by summarizing expert opinions on AI-based personalized mathematics learning services, thereby contributing to the exploration of the development strategies for "Math Cell".