• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.94-102
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• 2020

This study conducted a meta-analysis of the effects of self-management intervention for reducing the depression and anxiety of osteoarthritis patients. The research sources were PubMed, EMBASE, CINAHL, Ovid-MEDLINE and Korean databases from the Korean and foreign literature published until September 30, 2019. The R version 3.5.1 program was used to identify the effectiveness of self-management intervention. As a result, 11 studies from a total of 1,877 articles in the relevant literature were analyzed, and the total number of participants was 2,751. The results showed that the overall effect size for reducing depression and anxiety was -0.44 (95% CI: -0.66, -0.22) in osteoarthritis patients (p <.001). On the sub-analysis, depression was -0.37 (95% CI: -0.66, -0.08), and anxiety was -0.56 (95% CI: -0.92, -0.20). To explain the heterogeneity, the meta-ANOVA was the setting, duration, and provider of intervention. Analysis of the publication bias was performed by a Funnel plot, which was visually relatively symmetrical and was not asymmetric according to Egger's Regression test (bias=0.19, p=.928). The results of this study established clinical evidence by identifying the effects of self-management intervention for reducing the depression and anxiety of osteoarthritis patients.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.188-188
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• 2000

DLC (Diamond-Like Carbon) 박막은 높은 경도와 가시광선 및 적외선 영역에서의 광 투과도, 전기적 절연성, 화학적 안정성 및 저마찰.내마모 특성 등의 우수한 물리.화학적인 물성을 갖고 있기 때문에 여러 분야의 응용연구가 이루어지고 있다. 이러한 DLC 박막을 제작하는 과정에는 여러 가지가 있으나, 본 연구에서는 ECR-PECVD electron cyclotron resonance plasma enhanced chemical vapor deposition) 방법을 사용하였다. 이것은 최근에 많이 이용되고 있는 방법으로, 이온화률이 높을뿐만 아니라 상온에서도 성막이 가능하고 넓은 진공도 영역에서 플라즈마 공정이 가능한 장점이 있다. 기판으로는 4" 크기의 S(100)를 사용하였고, 박막을 제작하기 전에 진공 중에서 플라즈마 전처리를 하였다. 플라즈마 전처리는 Ar 가스를 150SCCM 주입시켜 5$\times$10-1 torr 의 진공도를 유지시키면서, ECR power를 700W로 고정하고, 기판 bias 전압을 -300 V로 하여 5분 동안 기판을 청정하였다. DLC 박막은 ECR power를 700W. 가스혼합비와 유량을 CH4/H2 : 10/100 SCCM, 증착시간을 2시간으로 고정하고, 기판 bias 전압을 0, -50, -75, -100, -150, -200V로 변화시켜가면서 제작하였다. 이때 ECR 소스로부터 기판까지의 거리는 150mm로 하였고, 진공도는 2$\times$10-2torr 였으며, 기판 bias 전압은 기판에 13.56 MHz의 RF power를 연결하여 RF power에 의해서 유도되는 negative DC self bias 전압을 이용하였다. 제작된 박막을 Auger electron spectroscopy, elastic recoil detection, Rutherford backscattering spectroscopy, X-ray diffraction, secondary electron microscopy, atomic force microscoy, $\alpha$-step, Raman scattering spectroscopu, Fourier transform infrared spectroscopy 및 micro hardness tester를 이용하여 기판 bias 전압이 DLC 박막의 특성에 미치는 영향을 조사하였다. 분석결과 본 연구에서 제작된 DLC 박막은 탄소와 수소만으로 구성되어 있으며, 비정질 상태임을 알 수 있었다. 기판 bias 전압의 증가에 따라 박막의 두께가 감소됨을 알 수 있었고, -150V에서는 박막이 거의 만들어지지 않았으며, -200V에서는 기판 표면이 식각되었다. 이것은 기판 bias 전압과 ECR 플라즈마에 의한 이온충돌 효과 때문으로 판단되며, 150V 이하에서는 증착되는 양보다 re-sputtering 되는 양이 더 많을 것으로 생각된다. 기판 bias 전압을 증가시킬수록 플라즈마에 의한 이온충돌 현상이 두드러져 탄소와 결합하고 있던 수소원자들이 떨어져 나가는 탈수소화 (dehydrogenation) 현상을 확인할 수 있었으며, 이것은 C-H 결합에너지가 C-C 결합이나 C=C 결합보다 약하여 수소 원자가 비교적 해리가 잘되므로 이러한 현상이 일어난다고 판단된다. 결합이 끊어진 탄소 원자들은 다른 탄소원자들과 결합하여 3차원적 cross-link를 형성시켜 나가면서 내부 압축응력을 증가시키는 것으로 알려져 있으며, hardness 시험 결과로 이것을 확인할 수 있었다. 그리고 표면거칠기는 기판 bias 전압을 증가시킬수록 더 smooth 해짐을 확인하였다.인하였다.

• Journal of Preventive Medicine and Public Health
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• v.50 no.5
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• pp.294-302
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• 2017

Objectives: The objectives of this study were to investigate the agreement between medical history questionnaire data and claims data and to identify the factors that were associated with discrepancies between these data types. Methods: Data from self-reported questionnaires that assessed an individual's history of hypertension, diabetes mellitus, dyslipidemia, stroke, heart disease, and pulmonary tuberculosis were collected from a general health screening database for 2014. Data for these diseases were collected from a healthcare utilization claims database between 2009 and 2014. Overall agreement, sensitivity, specificity, and kappa values were calculated. Multiple logistic regression analysis was performed to identify factors associated with discrepancies and was adjusted for age, gender, insurance type, insurance contribution, residential area, and comorbidities. Results: Agreement was highest between questionnaire data and claims data based on primary codes up to 1 year before the completion of self-reported questionnaires and was lowest for claims data based on primary and secondary codes up to 5 years before the completion of self-reported questionnaires. When comparing data based on primary codes up to 1 year before the completion of selfreported questionnaires, the overall agreement, sensitivity, specificity, and kappa values ranged from 93.2 to 98.8%, 26.2 to 84.3%, 95.7 to 99.6%, and 0.09 to 0.78, respectively. Agreement was excellent for hypertension and diabetes, fair to good for stroke and heart disease, and poor for pulmonary tuberculosis and dyslipidemia. Women, younger individuals, and employed individuals were most likely to under-report disease. Conclusions: Detailed patient characteristics that had an impact on information bias were identified through the differing levels of agreement.

• Journal of Labour Economics
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• v.26 no.3
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• pp.149-179
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• 2003

This study is analysing the factors determining individuals' behavior of selecting self-employment not only at the micro-level but also at the macro-level to put a particular emphasis on the financial constraint and unemployment rate representing business cycle. The data used in this study are "Korean Labor and Income Panal Study" of the Korea Labor Institute and "Economically Active Population Survey" of National Statistical Office. The main findings are as follows. First, human capital such as educational attainment and job experience has positive effects on male's selection of self-employment. The effects of job experience, however, changed negative for female's selection of self-employment. Second, real estate is significantly enhancing the selection probabilities of employer selection while the income from financial assets has negative effects. Third, entrepreneurial culture and environment are also raising the self-employment selection probability. Lastly, the regional unemployment rate representing the business cycle has positive effects on the self-employment selection after the financial crisis in 1997 both at the micro and macro level. Moreover, the coefficient of regional unemployment rate has changed positive in the structural model of self-employment selection controlling for selection bias and income opportunities, which means that individual's behavior of self-employment selection is rather complex when accounting for the uncertainties of income opportunities and diverse characteristics of self-employment workforce.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.3
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• pp.353-358
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• 1998

This paper presents development of a LNA operating at 1.71 ∼ 1.18 GHz used for a receiver of KOREA PCS base station and transponder. Using resistive decoupling circuits, a signal at low frequency is dissipated by a resistor. This design method increases the stability of the LNA and suitable for input stage matching. The LNA consists of low noise GaAs FET ATF-10136 and internally matched VNA-25. The LNA is fabricated with both the RF circuit and the self-bias circuits in aluminum housing. As a result, the characteristics of the LNA implemented here shows 30 dB in gain and 0.85 dB in noise figure.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.7
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• pp.683-693
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• 2011

In this paper, a design of high current and broad-band microwave bias-tee was presented for a stable bias of a high power amplifier. An input impedance of bias-tee should be shown to 50 ohm with the wideband in order to be stably-biased the amplifier. For this design of the bias-tee, a capacitor of bias-tee for a DC block was designed with a high wide-band admittance by a parallel sum of capacitors, and a inductor for a RF choke and a DC feeding was designed with a high wide-band impedance by a series sum of inductors. As this inductor and capacitor for the sum has each SRF, band-limitation of lumped element was driven from SRF. This limitation was overcome by control of a resonance's quality factor with adding a resistor. 1608 SMD chips for design's element was mounted on the this pattern for the designed bias-tee. The fabricated bias-tee presented 10 dB of return loss and wide-band about 50 ohm input impedance at 10 MHz~10 GHz.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.141-155
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• 2016

This research is a descriptive study that aimed to identify the health knowledge and optimistic bias related to stroke of middle-aged adults and the effect these had on their health-promoting lifestyle. The research was conducted from July 15 to August 15, 2015. The research subjects were 191 adults aged between 40 to 60 years. A structured questionnaire was used and self-administered for data collection. The PASW Statistics 21.0 and AMOS 21.0 programs were used for data analysis, and analysis of variance, correlation analysis, and structural equation modeling analysis were conducted. It was found that the middle-aged adults recognized smoking and hypertension as higher risk factors for stroke than diabetes, and there was a slight optimistic bias for stroke. Health knowledge about stroke had correlations with optimistic bias (r = -.143, p = .048) and health-promoting lifestyle (r = .268, p = < .001), while optimistic bias had correlations with interpersonal relationships and stress (r = .177, p = .014) in health-promoting lifestyle. In addition, health-promoting lifestyle affected health knowledge more than optimistic bias. In conclusion, it was found that the active information acquisition, health knowledge, and optimistic bias of middle-aged adults toward stroke were important factors pertaining to a stroke-related health-promoting lifestyle. Therefore, an education program to improve the health-promoting lifestyle related to stroke in middle-aged adults should be considered as a way to enhance stroke-related health knowledge and reduce optimistic bias.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.160-160
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• 2015

InGaZnO (IGZO) thin-film transistors (TFTs) are very promising due to their potential use in high performance display backplane [1]. However, the stability of IGZO TFTs under the various stresses has been issued for the practical IGZO applications [2]. Up to now, many researchers have studied to understand the sub-gap density of states (DOS) as the root cause of instability [3]. Nomura et al. reported that these deep defects are located in the surface layer of the IGZO channel [4]. Also, Kim et al. reported that the interfacial traps can be affected by different RF-power during RF magnetron sputtering process [5]. It is well known that these trap states can influence on the performances and stabilities of IGZO TFTs. Nevertheless, it has not been reported how these defect states are created during conventional RF magnetron sputtering. In general, during conventional RF magnetron sputtering process, negative oxygen ions (NOI) can be generated by electron attachment in oxygen atom near target surface and accelerated up to few hundreds eV by self-bias of RF magnetron sputter; the high energy bombardment of NOIs generates bulk defects in oxide thin films [6-10] and can change the defect states of IGZO thin film. In this study, we have confirmed that the NOIs accelerated by the self-bias were one of the dominant causes of instability in IGZO TFTs when the channel layer was deposited by conventional RF magnetron sputtering system. Finally, we will introduce our novel technology named as Magnetic Field Shielded Sputtering (MFSS) process [9-10] to eliminate the NOI bombardment effects and present how much to be improved the instability of IGZO TFTs by this new deposition method.

• Journal of Korean Academy of Nursing
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• v.47 no.2
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• pp.143-163
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• 2017

Purpose: This study was a systematic review and meta-analysis designed to investigate effects of psychoeducational intervention for cancer survivors. Methods: Ten databases were searched. Two reviewers independently performed the selection of the studies, data extraction and assessment. The risk of bias was assessed using Cochrane Collaboration's tool. To estimate the effect size, meta-analysis of the studies was performed using Comprehensive Meta-Analysis and RevMan programs. Results: Of 18,781 publications identified, 35 met inclusion criteria, and 25 studies were used to estimate effect size of psychoeducational intervention. Effect sizes (standardized mean difference [SMD]) were heterogeneous and random effects models were used in the analyses. Psychoeducational intervention was effective for quality of life (n=2,410, ES=0.23; 95% CI: 0.09~0.37), coping and self-efficacy (n=179, ES=0.68; 95% CI: 0.26~1.11), anxiety (n=1,786, ES=-0.26; 95% CI: -0.37~-0.15), depression (n=1,910, ES=-0.28; 95% CI: -0.37~-0.18), and psychological distress (n=2,242, ES=-0.31; 95% CI: -0.46~-0.17). Subgroup analysis showed that counseling was the most effective intervention for quality of life, and behavioral therapy was an effective intervention for all positive and negative outcomes. Publication bias was not detected except for psychological distress. Conclusion: Psychoeducational intervention appears to be effective in improving quality of life and coping and self-efficacy, and it is effective in reducing psychological symptoms in cancer survivors. Behavioral therapy, especially, is commonly effective in improving psychosocial outcomes. However, low-quality evidence, variability in the designs of existing studies, and publication bias suggest that additional high-quality trials should be conducted in the future.

• Nutrition Research and Practice
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• v.16 no.5
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• pp.565-576
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• 2022

BACKGROUND/OBJECTIVES: Various accelerometer equations are used to predict energy expenditure (EE). On the other hand, the development of these equations and their validation studies have been conducted primarily without including older adults. This study assessed the accuracy of 8 ActiGraph accelerometer equations to predict the energy cost of walking in older adults. SUBJECTS/METHODS: Thirty-one participants with a mean age of 74.3 ± 3.3 yrs were enrolled in this study (20 men and 11 women). The participants completed 8 walking activities, including 5 treadmill and 3 self-paced walking activities. The EE was measured using a portable indirect calorimeter, with each participant simultaneously wearing the ActiGraph accelerometer. Eight ActiGraph equations were assessed for accuracy by comparing the predicted EE with indirect calorimetry results. RESULTS: All equations resulted in an overall underestimation of the EE across the activities (bias -1 to -1.8 kcal·min^-1 and -0.7 to -1.8 metabolic equivalents [METs]), as well as during treadmill-based (bias -1.5 to -2.9 kcal·min^-1 and -0.9 to -2.1 METs) and self-paced (bias -1.2 to -1.7 kcal·min-1 and -0.2 to -1.3 METs) walking. In addition, there were higher rates of activity intensity misclassifications, particularly among vigorous physical activities. CONCLUSIONS: The ActiGraph equations underestimated the EE for walking activities in older adults. In addition, these equations inaccurately classified the activities based on their intensities. The present study suggests a need to develop ActiGraph equations specific to older adults.