• 제목/요약/키워드: Shift Characteristics

검색결과 1,279건 처리시간 0.028초

산화막의 질화, 재산화에 의한 계면트랩밀도 특성 변화 (Characteristics Variation of Oxide Interface Trap Density by Themal Nitridation and Reoxidation)

  • 백도현;이용재
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 1999년도 춘계종합학술대회
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    • pp.411-414
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    • 1999
  • 70 ${\AA}$-thick oxides nitridied at various conditions were reoxidized at pemperatures of 900$^{\circ}C$ in dry-O$_2$ ambients for 5~40 mininutes. The gate oxide interface porperties as well as the oxide substrate interface properties of MOS(Metal Oxide Semiconductor) capacitors with various nitridation conditions, reoxidation conditions and pure oxidation condition were investigated. We stuided I$\sub$g/-V$\sub$g/ characteristics, $\Delta$V$\sub$g/ shift under constant current stress from electrical characteristics point of view and breakdown voltage from leakage current point of view of MOS capacitors with SiO$_2$, NO, RNO dielectrics. Overall, our experimental results show that reoxidized nitrided oxides show inproved charge trapping porperites, I$\sub$g/-V$\sub$g/ characteristics and gate $\Delta$V$\sub$g/ shift. It has also been shown that reoxidized nitridied oxide's leakage currented voltage is better than pure oxide's or nitrided oxide's from leakage current(1${\mu}$A) point of view.

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쉬프트를 갖는 부분공간 반복법의 개선 (Improvement of Subspace Iteration Method with Shift)

  • 정형조;김만철;박선규;이인원
    • 한국강구조학회 논문집
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    • 제10권3호통권36호
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    • pp.473-486
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    • 1998
  • 본 논문에서는 쉬프트를 갖는 부분공간 반복법의 제한조건을 제거하여 수치적으로 안정한 고유치해석 방법을 제안 하였다. 쉬프트를 갖는 부분공간 반복범의 주된 단점은 특이성 문제 때문에 어떤 고유치에 근접한 쉬프트를 사용할 수 없어서 수렴성이 저하될 가능성이 있다는 점이다. 본 논문에서는 부가조건식을 이용하여 위와 같은 특이성 문제를 수렴성의 저하없이 해결하였다. 이 방법은 쉬프트가 어떤 고유치와 같은 경우일지라도 항상 비특이성인 성질을 갖고 있다. 이것은 제안방법의 중요한 특성중의 하나이다. 제안방법의 비특이성은 해석적으로 증명되었다. 제안방법의 수렴성은 쉬프트를 갖는 부분공간 반복법의 수렴성과 거의 같고, 두 방법의 연산횟수는 구하고자 하는 고유치의 개수가 많은 경우에 거의 같다. 제안방법의 효율성을 증명하기 위하여, 두개의 수치예제를 고려하였다.

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한국 복지의 새판 짜기를 위한 문제 인식과 방안 모색 (Exploring Policy Reform Options for the Welfare Regime Shift in Korea)

  • 홍경준
    • 한국사회복지학
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    • 제69권2호
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    • pp.9-30
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    • 2017
  • 체제의 전환은 정책의 변화나 정부의 교체보다는 덜 자주 발생한다. 사회경제 연합, 정치경제 제도, 공공정책의 양상이라는 체제를 구성하는 세 가지 요소 모두의 변화가 이루어질 때 체제의 전환은 가능하다. 이 연구는 한국 생활보장체제의 전환 가능성이 상당히 높은 지금의 시점에서 필요한 과제를 모색하는 것을 목적으로 한다. 이를 위해 2절에서는 한국 생활보장체제의 전개과정과 특성을 필자의 선행연구들에서 주장한 '개발국가형 생활보장체제'의 관점에서 살펴보았다. 3절에서는 한국 생활보장체제의 전환을 위해 필요하다고 생각하는 3가지의 과제를 제시하였는데, 그것은 정치제도의 개혁, 재정지출 구조의 개혁, 그리고 비공식 취업의 축소 등이다. 이러한 과제들은 사회경제 연합의 변화와 새로운 정치경제 제도의 등장을 요구한다는 점에서 체제전환과 관련한 정책적 과제이다. 한편, 4절에서는 한국 사회복지의 새판 짜기와 관련하여 우리 학문 공동체에 붙여보고 싶은 두 가지의 토론거리를 결론을 대신하여 제기하였다.

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강유전막의 잔류 분극 상태와 내부 전계가 Pt/Pb(Zr,Ti)O3/Pt 커패시터의 수소 열화 특성에 미치는 영향 (Effects of Remanent Polarization State and Internal Field in Ferroelctric Film on the Hydrogen-induced Degradation Characteristics in Pt/Pb(Zr, Ti)O3/Pt Capacitor)

  • 김동천;이강운;이원종
    • 한국재료학회지
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    • 제12권1호
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    • pp.75-81
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    • 2002
  • The ferroelectric properties of Pb(Zr,Ti)O$_3$[PZT] films degrade when the films with Pt top electrodes are annealed in hydrogen containing environment. This is due to the reduction activity of atomic hydrogen that is generated by the catalytic activity of the Pt top electrode. At the initial stage of hydrogen annealing, oxygen vacancies are formed by the reduction activity of hydrogen mainly at the vicinity of top Pt/PZT interface, resulting in a shift of P-E (polarization-electric field) hysteresis curve toward the negative electric field direction. As the hydrogen annealing time increases, oxygen vacancies are formed inside the PZT film by the inward diffusion of hydrogen ions, as a result, the polarization degrades significantly and the degree of P-E curve shift decreases gradually. The direction and the magnitude of the remnant polarization in the PZT film affect the motion of hydrogen ions which determines the degradation of polarization characteristics and the shift in the P-E hysteresis curve of the PZT capacitor during hydrogen annealing. When the remnant polarization is formed in the PZT film by applying a pre-poling voltage prior to hydrogen annealing, the direction of the P-E curve shift induced by hydrogen annealing is opposite to the polarity of the pre-poling voltage. The hydrogen-induced degradation behavior of the PZT capacitor is also affected by the internal field that has been generated in the PZT film by the charges located at the top interface prior to hydrogen annealing.

산업장 교대근무 근로자의 건강증진행위 예측요인 (Predictive Factors of Health promotion behaviors of Industrial Shift Workers)

  • 김영미
    • 한국직업건강간호학회지
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    • 제11권1호
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    • pp.13-30
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    • 2002
  • Industrial shift workers feels suffer mental stresses which are caused by unfamiliar day sleep, noisy environment, sleeping disorder by bright light, unusual contacts with family, difficulty in meeting with friends or having formal social meetings and other social limitations such as the use of transportation. Such stresses influence health of the workers negatively. Thus the health promotion policy for shift workers should be made considering the workers' ways of living and shift work specially. This study attempted to provide basic information for development of the health promotion program for industrial shift workers by examining predictive factors influencing health promotion behaviors of those workers. In designing the study, three power generation plants located in Pusan and south Kyungsang province were randomly selected and therefrom 280 workers at central control, boiler and turbine rooms and environmental chemistry parts whose processes require shift works were sampled as subjects of the study. Data were collected two times from September 17 to October 8, 1999 using questionnaires with helps of safety and health managers of the plants. The questionnaires were distributed through mails or direct visits. Means for the study included the measurement tool of health promotion behavior provided by Park(1995), the tool of self-efficacy measurement by Suh(1995), the tool of internal locus of control measurement by Oh(1987), the measurement tool of perceived health state by Park(1995) and the tool of social support measurement by Paek(1995). The collected data were analyzed using SPSS program. Controlling factors of the subjects were evaluated in terms of frequency and percentage ratio Perceived factors and health promotion behaviors of the subjects were done so in terms of mean and standard deviation, and average mark and standard deviation, respectively. Relations between controlling and perceived factors were analyzed using t-test and ANOVA and those between perceived factors and the performance of health promotion behaviors, using Pearson's Correlation Coefficient. The performance of health promotion behaviors was tested using t-test, ANOVA and post multi-comparison (Scheffe test). Predictive factors of health promotion behavior were examined through the Stepwise Multiple Regression Analysis. Results of the study are summarized as follows. 1. The performance of health promotion behaviors by the subjects was evaluated as having the value of mean, $161.27{\pm}26.73$ points(min.:60, max.:240) and average mark, $2.68{\pm}0.44$ points(min.:1, max.:4). When the performance was analyzed according to related aspects, it showed the highest level in harmonious relation with average mark, $3.15{\pm}.56$ points, followed by hygienic life($3.03{\pm}.55$), self-realization ($2.84{\pm}.55$), emotional support($2.73{\pm}.61$), regular meals($2.71{\pm}.76$), self-control($2.62{\pm}.63$), health diet($2.62{\pm}.56$), rest and sleep($2.60{\pm}.59$), exercise and activity($2.53{\pm}.57$), diet control($2.52{\pm}.56$) and special health management($2.06{\pm}.65$). 2. In relations between perceived factors of the subjects(self-efficacy, internal locus of control, perceived health state) and the performance of health promotion behaviors, the performance was found having significantly pure relations with self-efficacy (r=.524, P=.000), internal locus of control (r=.225, P=.000) and perceived health state(r=.244, P=.000). The higher each evaluated point of the three factors was, the higher the performance was in level. 3. When relations between the controlling factors(demography-based social, health-related, job-related and human relations characteristics) and the performance of health promotion behaviors were analyzed, the performance showed significant differences according to marital status (t=2.09, P= .03), religion(F=3.93, P= .00) and participation in religious activities (F=8.10, P= .00) out of demography-based characteristics, medical examination results (F=7.20, P= .00) and methods of the collection of health knowledge and information(F=3.41, P= .01) and methods of desired health education(F=3.41, P= .01) out of health-related characteristics, detrimental factors perception(F=4.49, P= .01) and job satisfaction(F=8.41, P= .00) out of job-related characteristics and social support(F=14.69, P= .00) out of human relations characteristics. 4. The factor which is a variable predicting best the performance of health promotion behaviors by the subjects was the self-efficacy accounting for 27.4% of the prediction, followed by participation in religious activities, social support, job satisfaction, received health state and internal locus of control in order all of which totally account for 41.0%. In conclusion, the predictive factor which most influence the performance of health promotion behaviors by shift workers was self-efficacy. To promote the sense, therefore, it is necessary to develop the nursing intervention program considering predictive factors as variables identified in this study. Further industrial nurses should play their roles actively to help shift workers increase their capability of self-management of health.

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부분 푸리에 영역과 선형 시간-주파수 분포의 옮김 불변 특성 (Fractional Fourier Domains and the Shift-Invariance Characteristics of Linear Time-Frequency Distributions)

  • 두락루트피에;강현구;윤석호;이주미;권형문;최상원;송익호
    • 한국통신학회논문지
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    • 제30권11C호
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    • pp.1060-1067
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    • 2005
  • 시간 영역과 주파수 영역을 사이의 공간을 뜻하는 부분 푸리에 영역으로 (fractional Fourier domains) 선형 시간-주파수 분포의 옮김 불변 특성을 일반화한다. 다른 선형 사주파수 분포와 달리 짧은 시간 푸리에 변환은(short time Fourier transform: STFT) 부분 푸리에 영역에서 크기 (magnitude-wise) 옮김 불변을 지니는데, 이 짧은 시간 푸리에 변환을 쓰면 분포를 좀더 쉽게 해석할 수 있다. 특히, 부분 푸리에 영역에서 크기 옮김 불변인 선형 분포는 짧은 시간 푸리에 변환뿐이라는 것을 밝힌다.

정상파 문제의 방사조건에 관한 연구 (A Study on the Numerical Radiation Condition in the Steady Wave Problem)

  • 이광호;전호환;성창경
    • 한국해양공학회지
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    • 제12권2호통권28호
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    • pp.97-110
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    • 1998
  • The numerical damping and dispersion error characteristics associated with difference schemes and a panel shift method used for the calculation of steady free surface flows by a panel method are an analysed in this paper. First, 12 finite difference operators used for the double model flow by Letcher are applied to a two dimensional cylinder with the Kelvin free surface condition and the numerical errors with these schemes are compared with those by the panel shift method. Then, 3-D waves due to a submerged source are calculated by the difference schemes, the panel shift method and also by a higher order boundary element method(HOBEM). Finally, the waves and wave resistance for Wigley's hull are calculated with these three schemes. It is shown that the panel shift method is free of numerical damping and dispersion error and performs better than the difference schemes. However, it can be concluded that the HOBEM also free of the numerical damping and dispersion error is the most stable, accurate and efficient.

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Impact of Long Working Hours and Shift Work on Unmet Health Care Need Among Korean Workers

  • Lee, Hye-Eun;Rhie, Jeongbae
    • Safety and Health at Work
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    • 제13권1호
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    • pp.17-22
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    • 2022
  • Background: This study aimed to identify work-related risk factors, including long working hours and night/shift work, for unmet health care need using data of a representative panel of Korean adults. Methods: Associations between work-related factors and unmet health care need were analyzed using data of 3,440 participants (10,320 observations) from the 2011-2013 Korean Health Panel Study. A generalized estimating equation was used for the analysis of repeated measures. Results: The prevalence of unmet health care was 16.6%. After adjusting sex, age, socioeconomic status, work characteristics, and working more than 60 hours per week (odds ratio [OR]: 1.43, 95% confidence interval [CI]: 1.23-1.65) or 50-59 hours per week (OR: 1.26, 95% CI: 1.08-1.46) instead of 40-49 hours per week and night/shift work (OR: 1.27, 95% CI: 1.06-1.51) were associated with unmet health care need. Conclusion: Long working hours and night/shift work are risk factors for unmet health care need among the Korean working population.

Effect of zero imputation methods for log-transformation of independent variables in logistic regression

  • Seo Young Park
    • Communications for Statistical Applications and Methods
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    • 제31권4호
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    • pp.409-425
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    • 2024
  • Logistic regression models are commonly used to explain binary health outcome variable using independent variables such as patient characteristics in medical science and public health research. Although there is no distributional assumption required for independent variables in logistic regression, variables with severely right-skewed distribution such as lab values are often log-transformed to achieve symmetry or approximate normality. However, lab values often have zeros due to limit of detection which makes it impossible to apply log-transformation. Therefore, preprocessing to handle zeros in the observation before log-transformation is necessary. In this study, five methods that remove zeros (shift by 1, shift by half of the smallest nonzero, shift by square root of the smallest nonzero, replace zeros with half of the smallest nonzero, replace zeros with the square root of the smallest nonzero) are investigated in logistic regression setting. To evaluate performances of these methods, we performed a simulation study based on randomly generated data from log-normal distribution and logistic regression model. Shift by 1 method has the worst performance, and overall shift by half of the smallest nonzero method, replace zeros with half of the smallest nonzero method, and replace zeros with the square root of the smallest nonzero method showed comparable and stable performances.

고분자 감응성막의 유기가스 반응 특성 (Response Characteristics of Organic Gas for Polymer Coating Materials)

  • 김정명;유승엽;장정수;권영수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1995년도 추계학술대회 논문집
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    • pp.273-276
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    • 1995
  • In this paper, the response characteristics of organic gases were investigated by using quartz crystal microbalance(Q.C.M) with different coating materials. The method for pattern was discussed in order to develope gas sensing system using neural network and pattern recognition. we analyzed the response characteristics by the area of frequency shift, which mean affinities of gases for coating material. The results shows that the Parameter made by the area of frequency shift has possibility to be used for pattern recognition and neural network. we found that each gas had different decrease pattern for coating material.

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