• 제목/요약/키워드: R-Factor

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Hall소자 재료의 특성지수 (The figure of merit for hall element materials)

  • 이정한
    • 전기의세계
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    • 제25권4호
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    • pp.53-58
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    • 1976
  • Criteria and significance of the factor .root..mu..$R_{u}$ or ($R_{u}$/.root.p) in Hall element material selection are discussed. And the chart which is useful to compare the figure of merit F=.root..mu..$R_{u}$ in Hall element materials is presented with the F's for some practical Hall device materials.als.

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압전 액츄에이터에 활용할 저온소결 압전 세라믹스에 관한 연구 (A Study on the Properties of the Low Temperature Sintered Piezoelectrics for Actuator Application)

  • 류성림;이상호;류주현
    • 한국전기전자재료학회논문지
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    • 제21권3호
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    • pp.232-235
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    • 2008
  • In this study, in order to develop the composition ceramics for multilayer piezoelectric actuator, PMN-PNN-PZT ceramics were fabricated using $Li_2CO_3$, $Na_2CO_3$, ZnO as sintering aids and their piezoelectric and dielectric properties were investigated according to the Bi substitution, Bi substitution induced grain growth and increase of sinterablity, And also, Bi substitution suppress secondary phase due to the liquid phase sintering effect. Bi substitution enhanced electromechanical coupling factor ($k_p$) and dielectric constant ($\varepsilon_r$), However, mechanical quality factor($Q_m$) was deteriorated, At the sintering temperature of 870 $^{\circ}C$ and Bi substitution of 1 mol%, density, electromechanical coupling factor ($k_p$), mechanical quality factor ($Q_m$), Dielectric constant ($\varepsilon_r$) and piezoelectric constant ($d_{33}$) of specimen showed the optimum values of 7,878 $g/cm^3$, 0,608, 835, 1603 and 397 pC/N, respectively for multilayer piezoelectric actuator application.

패션점포 판매원의 의복과 점포유형이 노년여성소비자들의 호감과 구매의도에 미치는 영향 (The effects of a fashion store saleswomans clothing and store type on elderly female consumers likability and intention to purchase)

  • 전호경;황선진
    • 한국의류학회지
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    • 제25권2호
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    • pp.293-302
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    • 2001
  • The purpose of this study was to investigate the effects of a saleswomans clothing and store type on elderly female consumers likability to a saleswoman. Also it was to study the effects of the factors consisting likability to a saleswoman on intent to purchase among elderly female consumers. 3(clothing formality: low, medium, and high)$\times$2(clothing style: clothing looking old vs. young)$\times$2(store type: high priced specialty store vs. low priced open market) complete randomized between subjects design using field experiments were conducted. Subjects were 240 elderly females aged 54-69. The results showed that likability to a saleswoman consisted of impression factor, service ability factor and caring factor. There was the significant three way interaction among three independent variables in the service ability factor(F(sub)2,228=15.62, P<.001). Regression Analysis showed that the impression factor($R^2$=0.29, F<.001) and the service ability factor($R^2$=0.06, F<.001) influenced the elderly consumers intention to purchase significantly. In conclusion, favorable appearances of a saleswoman is considered a crucial service quality influencing potential elderly consumers to purchase.

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수치계산에 의한 균열개구비의 영향도 평가에 관한 연구 (A Study on Parameter Sensitivity Study of Crack Opening Ratio by Using Numerical Calculation)

  • 최병기;권택용;이상열
    • 한국안전학회지
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    • 제12권2호
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    • pp.17-21
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    • 1997
  • The fatigue crack propagation rate has so far been measured by the effective stress intensity factor range Δ K/sub eff/. But no research has been done to study how much the crack opening ratio influences the expectation of the fatigue crack propagation. Therefore, this paper evaluates of the crack opening ratio on the fatigue crack propagation life by using the method of parameter sensitivity study. Summarizing the result ; ( 1 ) When the crack opening ratio U' is high, the effect of U' gets larger than any other except for the material factor m. But when U' is low, the effect is also diminished. Therefore, the selection of the lowest value possible is desirable in the evaluation of life. (2) When the value of the material factor m is high, the effect of crack opening ratio U' is increased, at the same time the effect of the other parameters also increased wholly. The effect of material factor m itself on life is high, but in case the material factor m is high, that the effect of each parameter on life get higher is unique. In designing, better attention to the material selection should be drawn. (3) In case the stress ratio R gets smaller, the effect of crack opening ratio U' is unchangeable. But the effect of R itself remarkably decreases, and the effect of material factor m somewhat decreases.

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압전 액츄에이터에 활용할 저온소결 압전 세라믹스에 관한 연구 (A Study on the Low Temperature Sintering Piezoelectric Ceramics for Piezoelectric Actuator Application)

  • 류성림;이유형;이상호;류주현
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.277-278
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    • 2007
  • In this study, in order to develop multilayer piezo-actuator, PMN-PNN-PZT ceramics were fabricated using $Li_2CO_3,\;Na_2CO_3$, ZnO as sintering aids and their piezoelectric and dielectric properties were investigated according to the Bi substitution. Bi substitution enhanced electromechanical coupling factor$(k_p)$ and dielectric constant$({\varepsilon}_r)$. However, mechanical quality factor was deteriorated. At the sintering temperature of $870^{\circ}C$ and Bi substitution of 1mol%, density, electromechanical coupling factor$(k_p)$, mechanical quality factor$(Q_m)$, Dielectric constant$({\varepsilon}_r)$ and piezoelectric constant$(d_{33})$ of specimen showed the optimum value of $7.878g/cm^3$, 0.608, 835, 1603 and 397pC/N, respectively.

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대학생의 질문저해요인과 비판적 사고성향 및 문제해결능력 (The Relationship among Hesitation Factor of Questions, Critical Thinking Disposition, and Problem Solving: The University Student's Perspective)

  • 우정희;유재용;박주영
    • 한국간호교육학회지
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    • 제21권3호
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    • pp.320-329
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    • 2015
  • Purpose: The purpose of this study was to identify the relationship among hesitation factor of questions, critical thinking disposition, and problem solving. Methods: Data were collected from 370 students at a university in D city using a structured questionnaire from April 1 to April 15, 2015. It was analyzed with frequency analysis, descriptive statistics, t-tests, ANOVA, and correlation analysis. Results: Subjects scored an average of $2.62{\pm}.52$ for hesitation factor of questions, $3.53{\pm}0.42$ for critical thinking disposition, and $3.44{\pm}0.44$ for problem solving. There were significant differences in the three variables according to satisfaction with major, self-expression, and interpersonal relationships. In addition, hesitation factor of questions exhibited a significant difference between genders. Hesitation factor of questions had a negative relationship with critical thinking disposition (r=-.23, p<.001) and with problem solving (r=-.34, p<.001). In addition, there was a statistically significant positive correlation between critical thinking disposition and problem solving (r=.69, p<.001). Conclusion: In order to improve critical thinking disposition and problem solving, we need to generate a lot of questions to the student's inside. We also need to develop appropriate teaching methods so that this can be expressed by the actual question coming from the control hesitation factor of questions.

비공비 혼합냉매 R-410A를 적용한 납작한 알루미늄 마이크로 멀티 튜브에서의 마찰손실에 관한 연구 (A study on the friction head loss in flat aluminum micro multi tubes with nonazeotropic refrigerant mixtures R-410A)

  • 이정근;민경호
    • Design & Manufacturing
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    • 제13권2호
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    • pp.37-43
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    • 2019
  • This study conducted a research as to condensation heat transfer friction loss headby using three types of flat micro multi-channel tubes with different processing of micro-fin and number of channels inside the pipes and different sizes of appearances. In addition, identical studies were conducted by using smoothing circular tubes with 5mm external diameter to study heat enhancement factor and pressure drop penalty factor. 1) The friction head loss showed an increase as the vapor quality and mass flux increased. In case of saturation temperature, it shows an increase as it gets lower. These factors are the reason occurring as the lower the saturation temperature is, the higher the density of refrigerant vapor gets. The influence of heat flux is similar as the dryness is low, but as it gets higher, it lowers in heat flux, and as the high temperature of high heat flux, it is a factor that occurs as the density gets lower. 2) RMS error of the in case of friction head loss, it showed to be predicted as 0.45~0.67 by Chisholm, Friedel, Lockhart and Martinelli. 3) As forfriction head loss penalty factor, the smaller the aspect ratio is, the larger the penalty factor gets, and as for the effect of micro-fin, the penalty factor increased because it decreases to the gas fluid the way groove for the refrigerant's flow.

치료 감호중인 조현병 환자에서 정신병질 성격과 대인관계문제 (Assessment of Psychopathic Personality and Interpersonal Problems in Korean Criminal Offenders with Schizophrenia)

  • 왕성근;권지현;이재우;지익성
    • 대한불안의학회지
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    • 제10권2호
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    • pp.157-162
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    • 2014
  • Objective : This study was conducted to evaluate the validity of the Korean Inventory of Interpersonal Problems (K-IIP) with Psychopathic Personality Inventory-Revised (PPI-R) to assess interpersonal problems in Korean criminal offenders with schizophrenia. Methods : The sample consisted of 187 inpatients with schizophrenia who had committed crimes. All participants filled out self-report questionnaires ofPPI-R and K-IIP. Results : The result showed that all scales of K-IIP were correlated highly with the PPI-R total score (r range=0.25-0.65). Correlations with K-IIP scales were highest for Blame Externalization, Rebellious Nonconformity, and Machiavellian Egocentricity scales (r range=0.50-0.66, 0.43-0.64, 0.39-0.58, respectively). All scales of K-IIP exhibited a negative correlation with Social Influences, Stress Immunity, Coldheartedness (C) scale ofPPI-R. Cold/Distant scale ofK-IIP was not correlated with C scale of PPI-R. All scales of K-IIP was highly correlated with PPI-R-factor-2 (r range=0.44-0.71) and negatively correlated with PPI-R-factor-l (r range=-0.03-0.38). Conclusions : Despite of strong correlation between PPI-R total score and K-IIP total score, K-IIP was not correlated with PPI-R-I that represents affective and interpersonal deficits. It suggests K-IIP may not proper for measuring the interpersonal problems of criminal offenders with schizophrenia. It will be needed other assessment scale for measuring the interpersonal problems of psychopathy in criminal schizophrenia.

청소년정서행동발달검사 표준화연구 자료를 활용한 학교폭력 피해 전국유병률 및 관련요인 조사 (Victims of Bullying among Korean Adolescents: Prevalence and Association with Psychopathology Evaluated Using the Adolescent Mental Health and Problem Behavior Screening Questionnaire-II Standardization Study Data)

  • 방수영;유한익;김지훈;김봉석;이영식;안동현;서동수;조수철;황준원;반건호
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • 제23권1호
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    • pp.23-30
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    • 2012
  • Objectives : This study was conducted to investigate the prevalence of victims of bullying and the demographic characteristics of victims, and their related psychopathology, in a Korean nationwide sample of youths in middle and high school over a one month period. Methods : During the autumn of 2009, students in the 7th to 12th grades at 23 secondary schools participated in a nationwide, cross-sectional study. The study subjects completed the Adolescent Mental Health and Problem Behavior Screening Questionnaire-II (AMPQ-II) and Symptom Checklist-90-Revision (SCL-90-R). Based on the data acquired, descriptive statistics, correlation coefficients and multiple logistic regression analysis were performed. Results : Among the 3364 participants, 2272 (67.54%) completed the questionnaire. The prevalence of victimization was 28.9%. Male gender was positively associated with victimization, and grade level was negatively related to victimization. The AMPQ-II bullying score (Factor 4) was significantly (p<.001) and positively correlated to the AMPQ-II student total score (r= 0.50), Worry and thought (Factor 1 ; r=0.38), Mood and suicide (Factor 2 ; r=0.31), Academic and Internet-related problems (Factor 3 ; r=0.24), Rule violations (Factor 5 ; r=0.23), and AMPQ-II teacher total score (r=0.11). Somatization (r=0.23), Obsessive-compulsive behavior (r=0.24), Interpersonal sensitivity (r=0.30), Depression (r=0.33), Anxiety (r=0.26), Hostility (r=0.30), Phobic anxiety (r=0.22), Paranoid ideation (r=0.36), and Psychoticism (r=0.31) results from the SCL-90-R were also found to be positively related to the AMPQ-II bullying score, and remained significant after adjusting for age and gender. A total of 26% of the victims reported suicidal ideations as compared to 9% of non-victims over the month prior to the evaluation ($x^2$=119.595, df=1, p<.001). The multiple logistic regression analysis indicated that the AMPQ-II bullying score significantly increased the risk of suicidal ideation [Exp(b)=1.55, df=1, p<.001] after adjusting for age and gender. Conclusion : School bullying was highly prevalent among Korean middle and high school students. This study provided strong evidence that suicidal ideation and psychopathology were serious problems among the victims of bullying.