• Title/Summary/Keyword: negative coefficients

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A Study on the Correlation Coefficients between Delayed Muscle Soreness after Eccentric Exercise, Muscle Strength, CPK and ALD (원심성 수축 운동 후 지연 된 근육통과 근력, CPK ALD의 상관관계에 대한 연구)

  • Choi Jae-Cheong
    • The Journal of Korean Physical Therapy
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    • v.11 no.1
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    • pp.103-110
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    • 1999
  • The purpose of this study was to analyze the correlation coefficients between delayed muscle soreness after eccentric exercise, muscle strength, CPK, and ALD. Subjects of this study were 9 male students. CPK, ALD that known as the indicators of muscle damage and eccentric strength of the Lt elbow flexors were measured prior to exercise. After measurements Hey Perform an isokinetic eccentric exercise of flexor group of 1 elbow(10 repetitions 3 bouts) by make use of KIN-COM isokinetic device. After exercise, CPK, ALD, and peak torque of elbow flexor group was measured at the just after exercise, 24hr after, 72hr after. Also muscle soreness level was evaluated at same intervals by make use of VAS(visual analog scale). The results were as follows : 1 . There was significant differencess or muscle soreness, CPK, ALD, peak torque with the passage or recovery time (p<0.001). 2. There was negative correlation coefficients between CPK and peak torque at 24hr after(p<0.05). 3. There was positive correlation coefficients between ALD and CPK at 24hr after(p<0.05). 4. There was no correlation coefficients between other variables but ALD was the most important factors that can be explains the muscle sur eness very well.

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Characterization and Standardization of Piezoelectric Thin Films (압전박막의 특성평가 및 표준화)

  • 김동국;지정범
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.12
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    • pp.1054-1059
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    • 2002
  • A great deal of research has been done in the field of characterization for piezoelectric thin films after the first report on the measurement for the piezoelectric coefficient of thin films in 1990. The main idea of this research is to provide a distinctive solution for the measurement and standardization of both the longitudinal and the transverse piezoelectric d-coefficients, d33 and d31, of ferroelectric thin films. In general, to get these two coefficients of thin films, two different measuring systems are required. Here, we propose the improved method for the evaluation of these two coefficients with single equipment and with the relatively convenient procedure. The two-step loading process of applying the both positive and the negative pressure has been introduced to acquire the piezoelectric coefficients. These results have been calibrated for both the longitudinal and 4he transverse piezoelectric d-coefficients, d33 and 431, of thin films by comparison with the virtual standard created from FEM. In this experiments, we have obtained d33 of 331pC/N and 031 of -92.2pC/N for the PZT thin films.

Characterization of Piezoelectric Thin Films (압전박막의 특성평가)

  • 김동국;변금효;김일두;이치헌;박정호;최광표;김호기
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.916-919
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    • 2000
  • A great deal of research has been done in the field of characterization for piezoelectric thin films after the first report on the measurement for the piezoelectric coefficient of thin films in 1990. The main idea of this research is to provide a distinctive solution for the measurement of both the longitudinal and the transverse piezoelectric d-coefficients, d$\sub$33/ and d$\sub$3l/, of ferroelectric thin films and also thick films. In general, to get these two coefficients of thin films, two different measuring systems are required. Here, we propose the improved method for the evaluation of these two coefficients with single equipment and with the relatively convenient procedure. The two-step loading process of applying the both positive and the negative pressure has been designed to acquire the piezoelectric coefficients. These results have beer calibrated for both the longitudinal and the transverse piezoelectric d-coefficients, d$\sub$33/ and d$\sub$31/, of thin films. In the first stage of the experiments, we have obtained d$\sub$33/ of 108pC/N and d$\sub$31/ of 57pC/N for the PZT thin films.

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Assessment of the material attractiveness and reactivity feedback coefficients of various fuel cycles for the Canadian concept of Super-Critical Water Reactors

  • Ibrahim, Remon;Buijs, Adriaan;Luxat, John
    • Nuclear Engineering and Technology
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    • v.54 no.7
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    • pp.2660-2669
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    • 2022
  • The attractiveness for weapons usage of the proposed fuel cycle for the PT-SCWR was evaluated in this study using the Figure-of-Merit methodology. It was compared to the attractiveness of other fuel cycles namely, Low Enriched Uranium (LEU), U/Th, Re-enriched Reprocessed Uranium (RepU), and Pu/Th/U. The optimal content of natural uranium, which can be added to Pu/Th to render the produced U-233 unattractive, was found to be 9%. A ranking system to compare the attractiveness of the various fuel cycles is proposed. RepU was found to be the most proliferation resistant fuel cycle for the first 100 years,while, the least proliferation resistant fuel cycle was the originally proposed Pu/Th one. The reactivity feedback coefficients were calculated for all proposed fuel cycles. All studied reactivity coefficients have the same sign implying that all the fuel cycles will behave neutronically in a similar way. The Pu/Th/U fuel was found to have the most negative value of the Coolant Void Reactivity which will help to restore the core to a safe status faster in case of a loss-of-coolant accident. The fuel and moderator temperature coefficients did not show significant differences between the fuels studied.

Negative Induced Polarization Responses over a Layered Earth (층상대지의 음수 유도분극 응답)

  • Kim, Hee Joon
    • Economic and Environmental Geology
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    • v.20 no.3
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    • pp.197-201
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    • 1987
  • Negative induced polarization (IP) responses are examined for a three-layered earth using a digital linear filter method. The negative IP response can occur when the geoelectric section is of type K or Q. The section of type K creates a more pronounced negative effect than that of type Q. For such sections, IP coefficients are determined as a function of the resistivity distribution and the electrode configuration, and only the IP coefficient of the first layer can be negative. As a result, the negative IP response can occur when the first layer is polarizable in the section of type K or Q. and the polarizabilities of the other layers can act to depress the negative response.

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CONVERGENCE AND DECAY ESTIMATES FOR A NON-AUTONOMOUS DISPERSIVE-DISSIPATIVE EQUATION WITH TIME-DEPENDENT COEFFICIENTS

  • Kim, Eun-Seok
    • Honam Mathematical Journal
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    • v.44 no.2
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    • pp.281-295
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    • 2022
  • This paper deals with the long - time behavior of global bounded solutions for a non-autonomous dispersive-dissipative equation with time-dependent nonlinear damping terms under the null Dirichlet boundary condition. By a new Lyapunov functional and Łojasiewicz-Simon inequality, we show that any global bounded solution converges to a steady state and get the rate of convergence as well, which depends on the decay of the non-autonomous term g(x, t), when damping coefficients are integral positive and positive-negative, respectively.

Mediating Effects of Emotional Venting via Instant Messaging (IM) and Positive Emotion in the Relationship between Negative Emotion and Depression (부정적 정서와 우울의 관계에서 인스턴트 메시징(Instant Messaging)을 통한 감정 표출과 긍정적 정서의 매개효과)

  • Lee, Hannah;An, Soontae
    • Research in Community and Public Health Nursing
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    • v.30 no.4
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    • pp.571-580
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    • 2019
  • Purpose: The purpose of this study is to examine the mediating effects of emotional venting via instant messaging (IM) and positive emotion in the relationship between negative emotion and depression. Methods: Online survey was conducted in Korea between 2 April and 7 April 2019. To obtain samples with representativeness, data were gathered by the professional research firm. A total of 250 Koreans were participated in this study. The collected data were analyzed using descriptive statistics, Pearson's correlation coefficients, and SPSS PROCESS macro to test the mediating effects. Results: This study analyzed the direct/indirect effects of negative emotion on emotional venting via IM, in the relationship between positive emotion and depression. Negative emotion had indirect effects on depression through emotional venting via IM and positive emotion. Both emotional venting via IM and positive emotion had dual mediating effects in the influence of negative emotion on depression. Conclusion: These results suggest that it is important to manage negative emotion to prevent depression. Also, this study confirmed that emotional venting via IM is a powerful factor influencing emotional recovery.

The Mediating Effect of Humor on the Relationship between Perceived Stress and Depression in College Students (대학생의 지각된 스트레스와 우울의 관계에서 유머의 매개효과)

  • Hong, Eunyoung
    • The Journal of Korean Academic Society of Nursing Education
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    • v.20 no.4
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    • pp.558-568
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    • 2014
  • Purpose: This study examines the relationships among perceived stress, humor style, responding humor and depression among college students and the mediating effect of humor between perceived stress and depression. Method: During the period May 6-16, 2013, a convenience sample of 200 subjects was obtained from college K in city G. Data analysis was performed by Pearson's correlation coefficients and regression analysis. Results: The average BDI score was 7.7. There were 40 (20.0%), 16 (8.0%), 8 (4.0%), and 11 (9.0%) students with mild, moderate, and severe depression, respectively. The group with depressive symptoms constituted 3.5% of students. There was a significant positive correlation between negative stress perception and depression. Conversely, there was a significant negative correlation between adaptive humor style and negative stress perception. Ultimately, there were significant negative correlations between positive stress perception, adaptive humor style, maladaptive humor style, responding humor and depression. To test the mediating effect of adaptive humor style in the relationship between negative stress perception and depression, a Sobel test was performed and Z-score of 1.7736 (p=.076) obtained. Conclusion: Though the mediating effect of an adaptive humor style on the relationship between perceived stress and depression was not significant, considering the negative correlation with depression, strategies to increase an adaptive humor style and responding humor is recommended to prevent depression in college students.

The Influence of Bullying Victimization on Reactive Aggression among Upper Elementary School Students: The Mediating Effect of Victim Justice Sensitivity and the Moderating Effect of Negative Urgency (또래괴롭힘 피해경험이 초등학교 고학년 아동의 반응적 공격성에 미치는 영향: 피해자 정의민감성의 매개효과와 부정긴급성의 조절효과)

  • Sim, Yei Rin;Park, Ju Hee
    • Human Ecology Research
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    • v.60 no.3
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    • pp.429-441
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    • 2022
  • This study examined the influence of bullying victimization on reactive aggression among upper elementary school students, and the mediating effect of victim justice sensitivity on the relationship between such victimization and aggression. It also investigated whether negative urgency moderates the influence of bullying victimization on reactive aggression. The participants were a group of 262 children (114 boys and 148 girls) who were fourth to sixth-grade students from 10 elementary schools located in Seoul, Gyeong-gi, and Daegu. The data were analyzed with descriptive statistics, Pearson's correlation coefficients, and SPSS Process Macro Model 5. The results were as follows: First, victim justice sensitivity mediated the influence of bullying victimization on reactive aggression among upper elementary school students. Second, negative urgency moderated the effect of bullying victimization on reactive aggression, whereas the impact of this was greater when the level of negative urgency was high. The results suggest that reactive aggression among upper elementary school students could be effectively decreased by preventing bullying victimization, and reducing the level of victim justice sensitivity and negative urgency.

OSCILLATION OF NEUTRAL DIFFERENCE EQUATIONS

  • Koo, Nam Jip
    • Journal of the Chungcheong Mathematical Society
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    • v.12 no.1
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    • pp.125-131
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    • 1999
  • We obtain some sufficient conditions for oscillation of the neutral difference equation with positive and negative coefficients $${\Delta}(x_n-cx_{n-m})+px_{n-k}-qx_{n-l}=0$$, where ${\Delta}$ denotes the forward difference operator, m, k, l, are nonnegative integers, and $c{\in}[0,1),p,q{\in}\mathbb{R}^+$.

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