• Proceedings of the KIEE Conference
• /
• 1993.11a
• /
• pp.178-180
• /
• 1993

The back bias effect on the breakdown voltage of SOI $p^+$-n diode is investigated. The breakdown voltage of the SOI $p^+$-n diode increases with the applied back bias. When the cathode electrode is used as a back bias, it is necessary to put the dielectric material between the Si-substrate and the bottom cathode electrode.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.35D no.4
• /
• pp.101-108
• /
• 1998

We examine experimentally the dependence of output width on DC bias, RF power, and RF frequency in a gain-switched semiconductor laser. The optimum short pulses are obtained around threshold DC bias. The DC bias to generatoe shorter pulses decreases the RF power increases, whereas it increases to above threshold as the RF freqnecy increases. The pulse width becomes less sensitive to the variations of the DC bias, as the RF bias, or frquency increases.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2009.05a
• /
• pp.130-131
• /
• 2009

AIP(arc ion plating)방법과 마그네슘 스퍼터링(DC reactive magnetron sputtering) 방법을 결합시킨 하이브리드 코팅 시스템으로 Cr-Si-N 코팅막을 합성하였다. 고분해능 TEM 및 SEM 분석들로부터 negative bias voltage에 따른 미세구조의 영향을 나타내었다. negative bias voltage의 증가에 따라 columnar microstructure가 amorphous microstructure로 변화하였다. bias voltage effect에 의해 Cr-Si-N 코팅막내 입자의 크기가 미세해지고 나노 복합체를 잘 형성하였다.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.15 no.5
• /
• pp.198-201
• /
• 2005

Carbon nanofibers were formed on silicon substrate which was applied by negative direct current (DC) bias voltage using microwave plasma-enhanced chemical vapor deposition method. Formation of carbon nanofibers were varied according to the variation of the applied bias voltage. At -250 V, we found that the growth direction of carbon nanofibers followed the applied direction of the bias voltage. Based on these results, we suggest one of the possible techniques to control the growth direction of the carbon nanofibers.

• Communications for Statistical Applications and Methods
• /
• v.11 no.3
• /
• pp.553-562
• /
• 2004

In this short communication we discuss the bias problems of CART in split variable selection and suggest a method to reduce the variable selection bias. Penalties proportional to the number of categories or distinct values are applied to the splitting criteria of CART. The results of empirical comparisons show that the proposed modification of CART reduces the bias in variable selection.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2009.10a
• /
• pp.159-160
• /
• 2009

AIP(arc ion plating)방법으로 CrN 코팅막을 합성하였다. 고분해능 SEM과 AFM 분석들로부터 negative bias voltage에 따른 미세구조의 영향을 나타내었다. negative bias voltage의 증가에 따라 columnar microstructure가 amorphous microstructure로 변화하였다. bias voltage effect에 의해 CrN 코팅막내 입자의 크기가 미세해지고 나노 복합체를 잘 형성하였다.

• Journal of Korean Physical Therapy Science
• /
• v.30 no.4
• /
• pp.82-91
• /
• 2023

Background: Randomized controlled trials (RCTs) provide evidence on the effectiveness and safety of interventions and inform systematic reviews and guideline preparation for clinical application. However, methodological flaws can occur in many RCTs, and Cochrane's risk of bias version 2 (RoB2) can be used to evaluate RCTs' risk of bias (RoB). However, physical therapy RCTs in Korea did not confirm RoB. Therefore, the purpose of this study was to evaluate RoB using RoB2 in RCTs published in the Korean Physical Therapy Journal. Design: Review. Methods: The RCTs subject to evaluation were RCTs published in 11 physical therapy journals in Korea from 2018 to 2022. RoB2 evaluated a total of five domains: bias arising from the randomization process, bias due to deviations from intended interventions, bias due to missing outcome data, bias in measurement of the outcome, and bias in selection of the reported result. Results: A total of 616 RCTs were evaluated. As for bias arising from the randomization process, high risk was the highest at 555 (90.1%), followed by low risk at 41 (6.7%) and some concerns at 20 (3.2%). For bias due to deviations from intended interventions, the proportion of some concerns was the highest at 390 (63.3%), followed by high risk at 218 (35.4%) and low risk at 8 (1.3%). As for the bias due to missing outcome data, the rate of low risk was the highest at 399 (64.8%), followed by high risk at 159 (25.8%) and some concerns at 58 (9.4%). As for bias in measurement of the outcome, high risk was the highest at 294 (47.7%), followed by low risk at 224 (36.4%) and some concerns at 98 (15.9%). In the bias due to missing outcome data, the ratio of high risk was the highest at 610 (99%), followed by low risk at 4 (0.7%) and some concerns at 2 (0.3%). Conclusion: Most of the RoB evaluation results of RCTs published in the Korean Physical Therapy Journal were rated as high risk. Methodological quality of RCTs needs to be improved.

• Journal of Korean Academy of Nursing
• /
• v.40 no.1
• /
• pp.52-59
• /
• 2010

Purpose: This study was conducted to provide basic data for developing education and health promotion programs for the prevention of cancer by identifying the relation between optimistic bias about cancer and cancer preventive behavior in Korean, Chinese, American, and Japanese residents in Korea. Methods: Using a questionnaire administered by the researcher, data were collected from a convenience sample of 600, 19 to 64-yr-old male and female Korean, Chinese, American, and Japanese residents in Korea. Data was collected between February 6 and 28, 2009. Results: Scores for optimistic bias about cancer by nationality were: Koreans, -1.03; Chinese, -0.43; Americans, -0.23; and Japanese, 0.05. The cancer preventive behavior scores were: Koreans, 43.17; Chinese, 71.84; Americans, 71.71; and Japanese, 73.97. Optimistic bias about cancer and cancer preventive behavior showed a significantly positive correlation in all participants: Koreans (r=.223, p=.006); Chinese (r=.178, p=.029); Americans (r=.225, p=.006); and Japanese (r=.402, p<.001). Conclusion: The greater the optimistic bias about cancer is, the lower the cancer preventive behavior. The findings suggest that nursing interventions are needed to reduce optimistic bias about cancer and to form a positive attitude towards cancer prevention because an optimistic bias about cancer adversely affects cancer preventive behavior.

• Journal of Advanced Marine Engineering and Technology
• /
• v.32 no.8
• /
• pp.1263-1268
• /
• 2008

In this paper, the low noise power amplifier for GaAs FET ATF-10136 is designed and fabricated with active bias circuit and self bias circuit. To supply most suitable voltage and current, active bias circuit is designed. Active biasing offers the advantage that variations in the pinch-off voltage($V_p$) and saturated drain current($I_{DSS}$) will not necessitate a change in either the source or drain resistor value for a given bias condition. The active bias network automatically sets a gate-source voltage($V_{gs}$) for the desired drain voltage and drain current. Using resistive decoupling circuits, a signal at low frequency is dissipated by a resistor. This design method increases the stability of the LNA, suitable for input stage matching and gate source bias. The LNA is fabricated on FR-4 substrate with active and self bias circuit, and integrated in aluminum housing. As a results, the characteristics of the active and self bias circuit LNA implemented more than 13 dB and 14 dB in gain, lower than 1 dB and 1.1 dB in noise figure, 1.7 and 1.8 input VSWR at normalized frequency $1.4{\sim}1.6$, respectively.

• The Korean Journal of Applied Statistics
• /
• v.33 no.4
• /
• pp.439-449
• /
• 2020

Meta-analysis provides a way of integrating several independent studies of interest. Since small studies with statistically significant results are more likely to be published, publication bias, which is a special case of selection bias, often occurs in meta analysis. Conditional likelihood and weighted estimating equation have been proposed to deal with publication bias, but they require to specify a correct selection probability model. In contrast, the pairwise pseudolikelihood approach can correct publication bias without fully specifying the correct selection probability model, but its performance in meta-analysis was not investigated. In this paper, we perform a numerical study about whether the pairwise pseudolikelihood approach is effective for solving publication bias arising from typical meta-analysis settings.