• Computers and Concrete
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• 제19권5호
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• pp.555-566
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• 2017

Recently some efforts have been performed to combine the advantages of light-weight and self-compacting concrete in one package called Light-Weight Self-Compacting Concrete (LWSCC). Accurate prediction of hardened properties from fresh state characteristics is vital in design of concrete structures. Considering the lack of references in mixture design of LWSCC, investigating the proper mixture components and their effects on mechanical properties of LWSCC can lead to a reliable basis for its application in construction industry. This study utilizes wide range of existing data of LWSCC mixtures to study the individual and combined effects of the components on the compressive strength. From sensitivity of compressive strength to the proportions and interaction of the components, two equations are proposed to estimate the LWSCC compressive strength. Predicted values of the equations are in good agreement with the experimental data. Application of lightweight aggregate to reduce the density of LWSCC may bring some mixing problems like segregation. Reaching a higher strength by lowered density is a challenging problem that is investigated as well. The results show that, the compressive strength can be improved by increasing the of mixture density of LWSCC, especially in the range of density under $2000Kg/m^3$.

• 전자공학회논문지S
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• 제36S권11호
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• pp.22-33
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• 1999

본 논문에서는 시스템의 차수가 고차이고 잡음과 시간지연이 있으며 파라미터가 변하는 비최소위상 시스템에 적응할 수 있는 다변수 일반화 자기동조 제어기의 설계 하중다항식 계수들을 온-라인으로 조정하는 방법을 제안한다. 다변수 일반화 최소분산 자기동조 제어기의 파라미터는 순환최소자승법으로 추정하고 설계 하중다항식 계수들의 값은 확률근사법인 Robbins-Monro알고리듬을 이용하여 자동 조절하였다. 제안한 다변수 자기동조 방법은 극제한방법보다 간단하고 효과적이다. 컴퓨터 시뮬레이션을 통해 제안한 방법이 시스템의 파라미터가 변하고 시스템의 영점이 단위원 밖에 있는 고차 다변수 시스템에 잘 적응함을 보였다.

• Journal of Mechanical Science and Technology
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• 제18권3호
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• pp.379-387
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• 2004

A novel flatness sensing system which is called the Flatness Sensing Inter-stand Looper(FlatSIL) system is suggested and a self-tuning PI control system using the FlatSIL is designed for improving the flatness of hot strip in finishing mill processes. The FlatSIL system measures the tension along the direction of the strip width by using segmented rolls, and the tension profile is approximated through the tension of each segmented roll. The flatness control system is operated by using the tension profile. The proposed flatness control system as far as the tension profile-measuring device works for the full strip length during the strip rolling in finishing mills. The generalized minimum variance self-tuning (GMV S-T) PI control method is applied to control the flatness of hot strip which has a design parameter as weighting factor for updating the PI gains. Optimizing the design parameter in the GMV S-T PI controller, the Robbins-Monro algorithm is used. It is shown by the computer simulation and experiment that the proposed GMV S-T PI flatness control system has better performance than the fixed PI flatness control system.

• International Journal of Naval Architecture and Ocean Engineering
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• 제4권3호
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• pp.302-312
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• 2012

Underwater vehicles play a very important role in underwater engineering. Water-tight junction box (WJB) is one of the key components in underwater vehicle. This paper puts forward a pressure self-adaptive water-tight junction box (PSAWJB) which improves the reliability of the WJB significantly by solving the sealing and pressure problems in conventional WJB design. By redundancy design method, the pressure self-adaptive equalizer (PSAE) is designed in such a way that it consists of a piston pressure-adaptive compensator (PPAC) and a titanium film pressure-adaptive compensator (TFPAC). According to hydro-mechanical simulations, the operating volume of the PSAE is more than or equal to 11.6 % of the volume of WJB liquid system. Furthermore, the required operating volume of the PSAE also increases as the gas content of oil, hydrostatic pressure or temperature difference increases. The reliability of the PSAWJB is proved by hyperbaric chamber tests.

• 패션비즈니스
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• 제18권5호
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• pp.134-143
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• 2014

The purpose of the study was to explore effects of fashion related work experience program and its satisfaction in middle schools. The study analyzed differences in self-efficacy of career decision making and fashion related career maturity before and after the program. The questionnaire developed by the researchers was collected from 114 participants enrolled in middle schools in Seoul or Kyunggido. The data were analyzed by common factor analysis, and independent sample t-test, using SPSS 18.0/Windows. The results demonstrated significant higher scores in self efficacy of career decision making, and fashion related career maturity after the program than before. Also, they showed high program satisfaction scores. The results of the study could be basic information for work experience program developers for high and middle school students.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.247-248
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• 2022

3D printer-based self-healing capsules have been proposed to heal cracks by enabling various structural designs, repeatable fabrication, and strength analysis of the capsules. The Fusion Deposition Modeling (FDM) method was used to design, analyze, and produce new self-healing capsules that are widely used at low cost. However, PLA extruded from FDM has low interlayer adhesion energy, and thus strength varies depending on the angle of load applied to the laminated layer and the concrete structure, thereby degrading the performance of the self-healing capsule. Therefore, in this paper, the structure of the capsule manufactured by the FDM PLA method has isotropic strength was designed. In addition, the fracture strength in the x, y, and z directions of the load applied through the compression test was analyzed. As a result, it was confirmed that the newly proposed capsule design has an isotropic fracture strength of 1400% in all directions compared to the existing spherical thin-film capsule.

• 유통과학연구
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• 제18권1호
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• pp.35-45
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• 2020

Purpose- This study examines the multi-mediation effect of personal self-congruity and social self-congruity to perceived value and brand attitude on aircraft customers in China. Research design, data and methodology- Survey was conducted on Chinese citizens who had flown via Chinese airlines and lived mainly in the Yangtze River delta. 727 cases were analyzed. SPSS 22.0 and AMOS 24.0 were used to analyze the data. Results - First, perceived economic value has a positive impact on personal self-congruity and social self-congruity but has no effect on brand attitude. Second, perceived functional value has a positive impact on personal self-congruity, social self-congruity, and brand attitude. Third, based on this, perceived economic value is not directly related to brand attitude. However, there is a relationship between perceived functional value and brand attitude, with personal self-congruity and social self-congruity having mediation effects. Conclusions - The Results show that perceived economic and functional value such as competitive airfare, mileage membership, check-in processes, diversified vouchers and coupons, and also basic services such as flight security and flight attendant service having an effect on personal self-congruity. To improve consumer brand attitude, airlines should take into consideration personal self-congruity factors such as their values and lifestyles, and their social self-congruity factors such as their social status and social security.

• 동서간호학연구지
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• 제14권2호
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• pp.24-31
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• 2008

Purpose: To survey and examine the relationships of self-esteem, family function, and self-efficacy in Chinese-Korean university students, and to provide supplemental data useful in counseling of university students during their adjustment to university life. Methods: A self-administered questionnaire with cross-sectional design was used. Participants were 103 Chinese undergraduate students in one university in Jilin, China. Descriptive statistics, t-test, ANOVA with Duncan's test and Pearson's correlation coefficients were used to analyze the data. Results: Mean scores were 3.40 for self-esteem, 2.32 for family function, and 2.93 for self-efficacy. The score for self-esteem differed significantly according to gender, body mass index (BMI), family number, education level of mother, and course of study. The mean score for family function differed significantly according to nursing satisfaction. The mean score for self-efficacy differed significantly according to BMI and nursing satisfaction. Positive correlations were evident between self-esteem and self-efficacy. Conclusions: To promote self-esteem and self-efficacy, development of nursing interventions to support family function is prudent.

• 재활간호학회지
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• 제13권2호
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• pp.151-160
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• 2010

Purpose: The purpose of this study was to determine the effects of empowerment education program on self-efficacy, self-care agency, self-care activities and physiologic parameters among hemodialysis patients. Method: Nonequivalent control group pretest-posttest design was used. There were 36 subjects in the experimental group and 35 subjects in the control group. The empowerment education program was administered for 4 weeks (1 time per week). Data were collected pre-treatment and post treatment. The $X^2$-test or Fisher's exact test, ANCOVA, t-test and paired t-test were performed to determine the group differences, using SPSS 14.0 version. Results: Self-efficacy, self-care agency, self-care activities and weight variation significantly improved after the empowerment education program in hemodialysis patients. Conclusion: The empowerment education program for hemodialysis patients was effective to improve the degree of self-efficacy, self-care activities and self-care agency and to decrease interdialytic weight variation.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1997년도 제25회 춘계학술대회
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• pp.253-259
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• 1997

A software for design of turbine bearings has been developed based on both the theoretical analysis and experimental investigation. Static and dynamic performance, i.e. load capacity, frictional loss, temperature distribution, stiffness and damping coefficients, stability etc., can be obtained by using this software taking into account the effects of three dimensional variation of lubricant viscosity, turbulence and inlet pressure. A performance test rig was developed by self-design and technology, which was used to verify static and dynamic characteristics and to investigate the proper boundary conditions for theoretical analysis. Consequently HANJUNG has developed the self-design technology for design of turbine bearings for power plants.