• Title/Summary/Keyword: 합리

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Development of a Model for Predicting Modulus on Asphalt Pavements Using FWD Deflection Basins (FWD 처짐곡선을 이용한 아스팔트 포장구조체의 탄성계수 추정 모형 개발)

  • Park, Seong Wan;Hwang, Jung Joon;Hwang, Kyu Young;Park, Hee Mun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.5D
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    • pp.797-804
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    • 2006
  • A development of regression model for asphalt concrete pavements using Falling Weight Deflectometer deflections is presented in this paper. A backcalculation program based on layered elastic theory was used to generate the synthetic modulus database, which was used to generate 95% confidence intervals of modulus in each layer. Using deflection basins of FWD data used in developing this procedure were collected from Pavement Management System in flexible pavements. Assumptions of back-calculation are that one is 3 layered flexible pavement structure and another is depth to bedrock is finite. It is found that difference of between 95% confidence intervals and modulus ranges of other papers does not exist. So, the data of 95% confidence intervals in each layer was used to develop multiple regression models. Multiple regression equations of each layer were established by SPSS, package of Statics analysis. These models were proved by regression diagnostics, which include case analysis, multi-collinearity analysis, influence diagnostics and analysis of variance. And these models have higher degree of coefficient of determination than 0.75. So this models were applied to predict modulus of domestic asphalt concrete pavement at FWD field test.

Numerical Analysis of Runup and Wave Force Acting on Coastal Revetment and Onshore Structure due to Tsunami (해안안벽과 육상구조물에서 지진해일파의 처오름 및 작용파력에 관한 수치해석)

  • Lee, Kwang Ho;Kim, Chang Hoon;Kim, Do Sam;Yeh, Harry;Hwang, Young Tae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.3B
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    • pp.289-301
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    • 2009
  • In this work, wave run-up heights and resultant wave forces on a vertical revetment due to tsunami (solitary wave) are investigated numerically using a numerical wave tank model called CADMAS-SURF (CDIT, 2001. Research and Development of Numerical Wave Channel (CADMAS-SURF). CDIT library, No. 12, Japan.), which is based on a 2-D Navier-Stokes solver, coupled to a volume of fluid (VOF) method. The third order approximate solution (Fenton, 1972. A ninth-order solution for the solitary wave. J. of Fluid Mech., Vol. 53, No.2, pp.257-271) is used to generate solitary waves and implemented in original CADMAS-SURF code. Numerical results of the wave profiles and forces are in good agreements with available experimental data. Using the numerical results, the regression curves determined from the least-square analysis are proposed, which can be used to determine the maximum wave run-up height and force on a vertical revetment due to tsunami. In addition, the capability of CADMAS-SURF is demonstrated for tsunami wave forces acting on an onshore structure using various configuration computations including the variations of the crown heights of the vertical wall and the position of the onshore structure. Based on the numerical results such as water level, velocity field and wave force, the direct effects of tsunami on an onshore structure are discussed.

Application of a Fictitious Axial Force Factor to Determine Elastic and Inelastic Effective Lengths for Column Members of Steel Frames (강프레임 기둥 부재의 탄성 및 비탄성 유효좌굴길이 산정을 위한 가상축력계수의 적용)

  • Choi, Dong Ho;Yoo, Hoon;Lee, Yoon Seok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.2A
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    • pp.81-92
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    • 2010
  • In design of steel frames, it is generally believed that elastic system buckling analysis cannot predict real behaviors of structures, while inelastic system buckling analysis can give informative buckling behaviors of individual members considering inelastic material behavior. However, the use of Euler buckling equation with these system buckling analyses have the inherent problem that the methods evaluate unexpectedly large effective lengths of members having relatively small axial forces. This paper proposes a new method of obtaining elastic and inelastic effective lengths of all members in steel frames. Considering a fictitious axial force factor for each story of frames, the proposed method determines the effective lengths using the inelastic stiffness reduction factor and the iterative eigenvalue analysis. In order to verify the validity of the proposed method, the effective lengths of example frames by the proposed method were compared to those of previously established methods. As a result, the proposed method gives reasonable effective lengths of all members in steel frames. The effect of inelastic material behavior on the effective lengths of members was also discussed.

A Study on Risks in China's Foreign Invested Water BOT Projects (중국 외국인투자 수처리 BOT 사업 리스크 연구)

  • Lee, Seungho;Choi, Jae-Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.3D
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    • pp.295-302
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    • 2010
  • Since the late 1990s, the BOT mode in China has been extensively used in the water sector in order to attract private investment, improve technical and operational efficiency, and expand the coverage of water services. The BOT mode has been hailed as this provides a win-win structure between the government and private players through formalized procedures and an optimal risk allocation. However, recent market analyses show that some foreign investors are reluctant to participate in the market or even retreat due to uncertainties and risks in the market. This study aims to explore various risks in the Chinese water BOT market based on the thorough literature review, fieldwork, and the case studies on the two wholly foreign-owned BOT water projects: the Chengdu No. 6 and the Shanghai Dachang Water Supply BOT projects. The research results indicate that the Chinese BOT market embraces high risks in political, institutional and legal, and financial systems. The key to a successful takeoff of the BOT mode in the Chinese water market depends on the extent to which the government will be able to remove risky factors in political, institutional and legal, and financing systems. This research outcome will provide a useful reference to the Korean construction companies which consider expanding business to overseas water markets in the form of public private partnership.

Quantitative assessment of spalling depth and width using statistical inference theory in underground openings (통계추론을 이용한 지하암반공동에서의 스폴링 깊이와 폭에 대한 정량적 평가)

  • Bang, Joon-Ho;Lee, In-Mo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.12 no.1
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    • pp.1-14
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    • 2010
  • Until now, the evaluation method of spalling depth using Martin et al. (1999)'s linear regression relations has long been known applicable. However, it is not likely that the proposed equation is applicable to the openings other than circular type and mostly overpredict the spalling depth in comparison with actual spalling cases. Moreover, the evaluation method to estimate the spalling width has not been presented yet; it is essential to evaluate the spalling width in addition to the spalling depth, because the shape of the spalled region influences the choice of suitable rock reinforcement. In this study, linear regression equations, in which normalized spalling depth ($d_f/W_D$) and normalized spalling width ($w_f/W_D$) are functions of three spalling evaluation indices, ${\sigma}_1/{\sigma}_c,\;D_{is}(={\sigma}_{max}/{\sigma}_c)$ and ${\sigma}_{dev}/{\sigma}_{cm}$, are established based on in-situ spalling observations and CWFS simulation results. Confidence intervals of 95% using the statistical inference theory are used in verifying the reliability of linear regression equations. Spalling depth ($d_f$) and spalling width ($w_f$) predicted from the proposed linear regression relations, which take three spalling evaluation indices into account, showed reasonable match with in-situ observations by adopting weighting factors considering the degree of variance of linear regression relations.

The contents of the Education for Conversation and Negotiation, and its Sociopolitical Implication (대화와 협상교육의 내용과 사회정치적 함의)

  • Shin, Hee-sun
    • Journal of Ethics
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    • no.75
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    • pp.63-98
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    • 2009
  • The Social Conflict Index in Korea is considerably high. In the situation where both parties' interests conflict each other, Korean society has shown immature democracy, which couldn't peacefully resolve the conflict because of the lack of tolerance against the counterparty's position. In terms of upbringing educated citizens, who could democratically communicate with others and approach problems, communication skill training is very important, reducing social costs by extreme conflict. Thus, this paper studied the necessity of communication skills training and its sociopolitical implication through case studies about "Communication and Negotiation" class, which is proceeded under university liberal education. Under current university curriculums, increased liberal education programs, related with speaking, focus on cultivating logical and critical thinking in the main. Based on these thinking skills, "Communication and Negotiation" has important implication in terms of cultivating mindset which resolves conflicts and considers other's position by collaborative and emotional perspectives. In terms of cultivating practical communication skills, this "Communication and Negotiation" class requires the change of teaching skills with various training programs, under students' active participation and feedback in the class exercise for resolving problems. Ultimately, through "Communication and Negotiation" class, and as members of society, students could learn matured citizenship and sense of responsibility by respecting others' position and reasonably resolving conflicts.

Sociality of Emotions through Communition of Drama (드라마의 소통을 통해 본 감정의 사회성)

  • Paik, Hoon-Kie
    • Journal of Korea Entertainment Industry Association
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    • v.13 no.7
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    • pp.25-38
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    • 2019
  • For many years, emotions have been regarded as dangerous as well as obstructive to reason and rationality. Even in the history of dramatic genres based on human behavior, emotions are often portrayed as errors or flaws that lead to the collapse of characters, even though they are presented as powerful motives to evoke the characters' actions. Based on the development of the cognitive science field today, it is revealed how emotion is important for human thinking, judgment and action, and how closely reason and emotion are combined. This study examines emotions dealt with in drama genres on the basis of the sociality of emotions. Emotions also play a crucial role in the change and judgment of the audience of drama. This study examines the sociality of emotions and looks at the social aspect of individual emotions through the movie as a text. Just as horror movies attempt to communicate using and expanding feelings of fear, the movie uses the emotions of 'Sad' and 'Losing' to try to expand and share it. And I look into the mechanism in which the emotions of the characters in drama are transmitted to the audience in the form of empathy.

The Thought of the theory about the laws of motion in 『Mojing』 (『묵경』 중의 물체 운동에 관한 이론 고찰)

  • Hwang, SeongKyu
    • The Journal of Korean Philosophical History
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    • no.29
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    • pp.203-230
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    • 2010
  • This article is aimed for to state the rationality of Mojia and reveal the scientific meaning in the theories related to the motion of objects in Mojing: the basic approach to the principle of gravitation in building castle, and comprehension and application of the principle in the lever devised for improving productivity as well as in an inclined plane. It is denied in this article that the technical advance and the positive influence on the people is achieved by Mojias only because they were occupied in the filed of craft. Mojia was one of the schools of Qin in the early stage who realized how important science wass for the better society focused on humanity. Furthermore, they were the frontiers who pursued the proper society through science. Therefore, the scientific theories claimed by Mojia is not emphasized only on the deducting regularity of nature. Instead, it could be theorized only by guaranteeing the welfare for common people and having close relation to it. The Chinese philosophy in the early Twentieth century had vigorous interest in the Mojia's opinions in science and set about conducting study in this part. Based on the study, it was revealed that the Mojia's opinion toward motion is superior to that of the West. Furthermore, it was proved to reflect the main idea in Mojia: the love for common people. Particularly, the theories from Mojia can be so applicable to today's life that some scholars regret the lack of interest in Mojia for the time and even scold themselves for the retarded progress in science of China.

Optimization of Flushing through Correlation Analysis between the Number of Flushing and Residual Activity in PET/CT (PET/CT에서 최적의 플러싱횟수를 위한 잔류방사능과의 상관분석)

  • Woo-Yeong Choi;Yeong-Sik Jee;Chang-Yong Yoon
    • Journal of the Korean Society of Radiology
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    • v.17 no.5
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    • pp.701-707
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    • 2023
  • In PET/CT, the injection volume of 18F-FDG directly affects the SUV(standard uptake value), which can affect the reading results. Therefore, it is important to inject the correct dose value of 18F-FDG. In this study, we performed the correlation between the residual radioactivity remaining in the syringe and catheter insertion device according to the number of flushing during 18F-FDG injection. CRC-25R dose calibrator, catheter insertion devices, 3 cc syringes and 50 cc physiological saline were used in this study, and the results were statistically analyzed. As a result, the total residual radioactivity of the syringe and catheter insertion device remained the highest at 5.84% after two flushing, and the least remained at 1.49% after five flushing. The correlation analysis results showed that the number of flushing had a negative correlation with the residual radioactivity of the syringe at -0.436 and the catheter insertion device at -0.300. As a result of one-way distributed analysis of the average according to the number of flushing, the syringe showed a significant decrease at 4 times, and the catheter insertion device showed a significant decrease at 5 times. However, considering that an average of 0.8% remains in the case of catheter insertion devices, four time flushing seems to be the most appropriate.

Indigenous psychological analysis of trust in Korean culture (한국인의 신뢰의식에 나타난 토착심리 탐구)

  • Young-Shin Park;Uichol Kim
    • Korean Journal of Culture and Social Issue
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    • v.11 no.spc
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    • pp.21-55
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    • 2005
  • The purpose of this paper is to examine the concept of trust in Korean culture using the indigenous psychological analysis. First, this paper raises central questions that arise in Korean families, schools, companies and society: 1) Why are some Korean families disintegrating? 2) What core values do Korean schools teach? 3) What are the goals that Korean companies pursue? 4) Does trust exist in Korean society? Second, this paper reviews a series of empirical studies conducted using the indigenous psychology approach. The results indicate the following three major themes: 1) trust is based on relational culture and ingroup identity; 2) emotional attachment and bond provide the basis of trust; 3) the emphasis on cultivation of virtue through constant self-cultivation rather than ability and the control of the environment. Third, this paper raises central issues that need to be addressed: 1) the extension and expansion of trust beyond the narrow confines of the family and ingroup to include outgroup members; 2) recognition and balance of public rationality and private emotions and relations in society; 3) the achievement of balance between self-regulation and the control of the environment.