• Journal of Ship and Ocean Technology
• /
• 제10권4호
• /
• pp.1-11
• /
• 2006

The finite volume based multi-block RANS code, WAVIS developed at MOERI is applied to the numerical self-propulsion test. WAVIS uses the cell-centered finite volume method for discretization of the governing equations. The realizable $k-{\epsilon}$ turbulence model with a wall function is employed for the turbulence closure. The free surface is captured with the two-phase level set method and body forces are used to model the effects of a propeller without resolving the detail blade flow. The propeller forces are obtained using an unsteady lifting surface method based on potential flow theory. The numerical procedure followed the self-propulsion model experiment based on the 1978 ITTC performance prediction method. The self-propulsion point is obtained iteratively through balancing the propeller thrust, the ship hull resistance and towing force that is correction for Reynolds number difference between the model and full scale. The unsteady lifting surface code is also iterated until the propeller induced velocity is converged in order to obtain the propeller force. The self-propulsion characteristics such as thrust deduction, wake fraction, propeller efficiency, and hull efficiency are compared with the experimental data of the practical container ship. The present paper shows that hybrid RANS and potential flow based numerical method is promising to predict the self-propulsion parameters of practical ships as a useful tool for the hull form and propeller design.

• Wind and Structures
• /
• 제2권1호
• /
• pp.41-49
• /
• 1999

The flutter of a bridge is induced by self-excited force factors such as lift, drag and aerodynamic moment. These factors are associated with flutter derivatives in the analysis of wind engineering. The flutter derivatives are the function of structure configuration, wind velocity and response circular frequency. Therefore, the governing equations for the interaction between the wind and dynamic response of the structure are complicated and highly nonlinear. Herein, a numerical algorithm through graphical technique for the solution of wind at flutter is presented. It provides a concise approach to the solution of wind velocity at flutter.

• Wind and Structures
• /
• 제7권6호
• /
• pp.421-447
• /
• 2004

This paper presents a time domain approach for predicting buffeting response of long suspension bridges under skew winds. The buffeting forces on an oblique strip of the bridge deck in the mean wind direction are derived in terms of aerodynamic coefficients measured under skew winds and equivalent fluctuating wind velocities with aerodynamic impulse functions included. The time histories of equivalent fluctuating wind velocities and then buffeting forces along the bridge deck are simulated using the spectral representation method based on the Gaussian distribution assumption. The self-excited forces on an oblique strip of the bridge deck are represented by the convolution integrals involving aerodynamic impulse functions and structural motions. The aerodynamic impulse functions of self-excited forces are derived from experimentally measured flutter derivatives under skew winds using rational function approximations. The governing equation of motion of a long suspension bridge under skew winds is established using the finite element method and solved using the Newmark numerical method. The proposed time domain approach is finally applied to the Tsing Ma suspension bridge in Hong Kong. The computed buffeting responses of the bridge under skew winds during Typhoon Sam are compared with those obtained from the frequency domain approach and the field measurement. The comparisons are found satisfactory for the bridge response in the main span.

• 한국지반환경공학회 논문집
• /
• 제15권3호
• /
• pp.41-48
• /
• 2014

준설토에 대한 연구는 주로 준설토의 1차원 침강 및 자중압밀 특성을 파악하는 실험적 연구가 진행되었다. 하지만 양질의 준설지반 확보를 위한 효과적인 투기장의 설계와 배출수에 의한 환경오염을 최소화하기 위해서는 준설토의 투기에 의한 유동특성의 체계적인 연구가 필요하다. 본 연구에서는 준설토 투기장의 펌핑에 의한 토사의 유동 형상을 모사하기 위하여 준설토사를 단일상으로 가정하고 연속 방정식을 유도하여 좌표축에 따른 힘 평형 방정식을 유도하였다. 준설토장의 3차원 거동 해석을 위한 컴퓨터 연산 부하와 모델링 소요시간을 최적화하기 위하여, 토체의 깊이 방향으로 적분을 수행하는 깊이 적분 방법을 지배 방정식에 적용하여, 3차원적 지형조건을 고려할 수 있도록 하였다. 지배 방정식의 보간함수를 이용한 공간분할에서 Petrov-Galerkin 수식화 기법을 적용하였다. 일반화된 사다리꼴 법칙으로 시간적분을 수행하고 Newton의 반복과정을 이용할 수 있도록 근사화시켰다. 가중행렬은 DG과 CDG 기법을 적용하였으며, 준설토 유동해석에서 가중행렬에 따른 수치적인 안정성을 평가하기 위하여 사각형 기둥 슬럼프 시뮬레이션을 수행하였다. 수치기법에 대한 비교 분석 결과는 DG 기법을 적용한 SU/PG 수식화가 유사진동을 최소화시키는 가장 안정적인 수치해석결과를 보여주는 것으로 나타났다.

• 대순사상논총
• /
• 제24_2집
• /
• pp.231-270
• /
• 2015

This thesis examined Chu Hsi's self-cultivation theory as the representative theory of cultivation in Confucianism, while juxtaposing it to self-cultivation theory in Daesoon thought, concentrating on its similarity and difference. Neo-Confucianism is a scholarship which has wielded a tremendous influence upon East Asia, while functioning as an official scholarship for long period up to Yuan, Ming, and Ching period, after achieving its synthesis by Chu Hsi. After 13th century, Neo-Confucianism has been a representative academic system in Confucianism, and self-cultivation theory was in its center. It suggested various virtues that classical scholars have to equip to fulfill the sainthood and the politics of royal road. The self-cultivation theory of Chu Hsi was developed upon the basis of the theory 'Li-Qi' and the theory of mind. Here, the practice of Geokyung(morally awakened state with a reverent spirit in every moment) and Gyeokmul-tsiji(reaching into the utmost knowledge through investigation of things) formed a nucleus of Chu Hsi's self-cultivation theory. While Geokyung was to reveal one's true nature through cultivation of mind, Gyeokmul-tsiji was to demonstrate the complete use of mind's essence and function. Chu Hsi's self-cultivation theory attempted to realize the unity of heaven and man, and through cultivating self and governing people, it also tried to achieve its ideal of the society of Great Union(Daedong). Daesoon Thought is originated from Sangjenim who has descended to this world as a human being called Jeungsan. He went on his circuit to rectify the disorder of heaven and earth for 9 years to rectify the Three worlds of heaven, earth and human being which were faced with total annihilation due to its rule of mutual conflict, while creating an earthly paradise. Respecting the will of Sangjenim, Dojunim established the foundation of Do through launching 'Meukeukdo' and setting tenet, creed and object so that the cultivators (Doins) could believe and respect the truth of Sangje's great itineration (Daesoon). Among those, the two components of creed, which are four fundamental principles and the three fundamental attitudes are of great account as precept and cardinal point. Through this means, the cultivators of Daesoonjinrihoe aspire to guard against self-deception through transforming the human spirit, to realize earthly immortality through renewing human beings, and to create an earthly paradise through transforming the world. This thesis attempted to compare and analyze the theory of self-cultivation in Neo-Confucianism and Daesoon Thought in the aspect of ground, method, and object of cultivation. First, as for the ground of cultivation, the doctrines of Chu-tzu and Daesoon thought place the essence of cultivation on 'heaven'. Yet, whereas the former postulates Taekeuk (the Great Ultimate) as a principle as well as the heaven of a natural order, Daesoon thought postulates Sangenim as the heaven of superintendence as well as the heaven of a natural order, signified as its equation of Daesoon with circle, along with the unity of Meukeuk (Endlessness) and Taegeuk (the Great Ultimate). Further, the doctrine of Chu-zhu and Daesoon thought is identical in the point that both thoughts see mind as the subject of cultivation, while trying to restore a pure essence. Nevertheless, whereas Neo-Confucianism intends to give scope to ability of the complete use of mind's essence and function, Daesoon Thought sees mind as the essence which is used by spiritual beings and as an organ that heaven, earth and human being rely upon as the center of the universe. In the aspect of method of cultivation, the doctrine of Chuzhu lays emphasis on the rational factor in that it brightens its 'myung-deoki'(bright inner virtue),' while trying to correspond to the law of heaven on the basis of 'Geokyung' and 'Gyeokmul-tsiji.' On the contrary, Daesoon thought lays much emphasis on faith factor in that it aspires for human perfection based on the restoration of conscience by cultivating Daesoonjinri with sincerity, reverence and faith along with 'quieting the heart-mind', 'quieting the body', 'respecting the God of the Ninth Heaven', and 'observing ritual practice on the basis of the faith in Sangjenim. Yet, both thoughts have similarities in that cultivation of body forms the basis and that they attempt to realize their ideals through cultivation in daily life while taking 'Guarding against self-deception' as the key method of self-cultivation.' However, the principle of Chu-zhu can be said to be a voluntary and autonomous practice based on scripture of the saint as well as self-reflection. On the other hand, Daesoon thought reveals certain difference in that it combines faith factor with one's self-effort by concentrating on cultivation under the presence of Sangjenim as the object of belief and the spirits of heaven and earth. In the aspect of object of cultivation, both thoughts share similarities in that the saint and the perfected gentleman with a moral virtue as an ideal image of men in both thoughts attempt to realize each of their 'myung-deok' in human nature as a heavenly mandate while respecting morality. Further, they also share similarity in the point that the desirable characters in both thoughts want to participate in harmonious creation and nurturance. Yet, the perfected gentleman with a moral virtue is also characterized by its aim for a new heaven and earth where there is no mutual conflict but mutual beneficence, by promoting the moral influence and virtue of Sangjenim over one's own virtue, while practising the mutual beneficence of all life through harmonious union of divine beings and human beings.

• Animal cells and systems
• /
• 제16권1호
• /
• pp.27-33
• /
• 2012

The suprachiasmatic nucleus (SCN) of the teleost hypothalamus contains a central circadian pacemaker, which adjusts circadian rhythms within the body to environmental light-dark cycles. It has been shown that exposure to darkness during the day causes phase shifts in circadian rhythms. In this study, we examined the effect of exposure to darkness on the mRNA expression levels of two circadian clock genes, namely, $Period2$ ($Per2$) and $Cryptochrome1$ ($Cry1$), and the rate-limiting enzyme in melatonin synthesis, arylalkylamine $N$-acetyltransferase-2 (Aanat2), in the pineal gland of olive flounder, $Paralichthys$ $olivaceus$. The expression of these genes showed circadian variations and was significantly higher during the dark phase. These changes may be involved in the mechanism of dark-induced phase shifts. Furthermore, this study suggests that olive flounder may be a teleost model to investigate the localization and function of circadian oscillators.

• 농촌지도와개발
• /
• 제28권3호
• /
• pp.153-165
• /
• 2021

This study aims to analyze the difference in production elasticity based on the types of agricultural labor input regarding its qualitative difference in Jeju mandarin production. To estimate the production function of qualityadjusted labor, we have set up a Quality-Adjusted Index based on the market wage of the agricultural field. We have conducted a multiple regression analysis of the newly estimated labor inputs using the Ordinary Least Squares regression. Results show that the production efficiency of aggregate total labor hours (quality-unadjusted labor input) is overestimated compared to quality-adjusted labor with qualitative labor homogeneity. Moreover, by analyzing household labor and employment labor, we have observed that the marginal productivity of household labor exceeds that of employment labor. In conclusion, this study verifies that securing labor input homogeneity is crucial for analyzing agricultural labor hours' economic efficiency accurately.

• 한국콘텐츠학회논문지
• /
• 제22권6호
• /
• pp.638-651
• /
• 2022

지난해는 한반도 평화권에 대한 새로운 인식으로 '2021 DMZ양구평화선언문'이 채택되었다. DMZ관련 법과 제도, 지속가능한 생태·환경, 안보·공동체 관점에서 새로운 인식과 접근 등에 관한 필요성이 대두되고 있다. 강원도는 DMZ 접경지역을 평화지역으로 만들기에 상당한 노력을 기울이고 있다. '평화특별자치도' 설치를 위하여 지속적으로 공론화시키고 있다. 이 연구를 통하여 한반도 접경지역이 담의 기능에서 통로의 기능으로의 대전환이 필요함을 제시하였다. 경계의 벽을 허물어 소통의 흐름을 위한 새로운 지평으로 지속발전 가능한 지역으로 나갈 수 있는 토대가 되어야 한다. 한반도 접경지역 중에서 강원도 지역이 왜 평화지역으로 나가야 하는 지에 대하여 주장하였다. 결론은 한반도 통일 정책의 새로운 시각으로 '평화권'에 대한 이해와 아젠다의 정립에 있어서 중요하다. 또한 유네스코 생물권보전지역의 지정을 활용한 DMZ일원의 생태환경 보전의 가치가 미래 지구환경보전이라는 가치와 맞물려야 한다. 평화지역은 한반도를 넘어 범세계화를 위한 미래지향적 글로컬 지역주의 시대를 열어야 한다. 그 방법은 4차 산업혁명의 기술요소 반영이 필요함을 주장하였다. 그동안 접경지역은 아픔과 상처의 피해 지역이었다. 이제 강원도 평화지역은 치유를 통한 평화공존의 지역가치 실현의 공간으로 거듭나야 할 것이다. 이 연구는 강원도 접경지역이 새롭게 평화지역으로서의 가치를 조명하여 지속가능 발전을 위해 나아갈 방향의 제시이다.

• 한국조경학회지
• /
• 제31권2호
• /
• pp.36-47
• /
• 2003

The purpose of this study is to examine the present problems relating to the legislation and execution of adornment of buildings in the provinces, and to explore ways to improve the role and function of adornment of buildings in terms of public art. In order to do that, the related national law and enforcement decree and the local regulations and rules were analysed. In addition the catalogues on the adornments of buildings that are managed by 31 cities and counties of Gyeonggi-Province were also compared and analysed. As a result of our survey, it has been determined that the reform of the adornments of buildings must be executed on the national and local levels. On the local level, the revision of regulations must occur simultaneously with the changes of national law and enforcement decrees. In many local self-governing bodies, there are quite a lot of discrepancies between their regulations and the upper law. Therefore, people can be confused regarding the sensitive problems such as the types of buildings that are required to display adornments and the proportion of the cost to the construction cost. In addition the effects of the improvements to national laws are often delayed. For example, the updated national law requires committee members to be appointed on the basis of merit, the announcement of the deliberation results, and the establishment of provisions regarding the management of existing structures. Unfortunately, improvements to the national law are not followed through on a local level. Concerning national legislation, the following improvements are necessary to minimize these problems. First, the western concept of‘public art’must be imported to Korea and applied to future legislation regarding adornment of buildings. Second, the perception of the purpose of adornment of buildings must be changed from‘art promotion’to‘improvement of the urban environment’Third, it is impractical to require private citizens to fund public worts of In. Korea requires an organized federal funding system for the commission of public art, which is to be controlled by committee. Finally, the definition of public artwork must be enlarged to include a more broad range of art, such as landscape architecture. In addition, continuing care of existing public worts of art must be managed systematically and strengthened.

• 한국환경교육학회지:환경교육
• /
• 제17권2호
• /
• pp.94-105
• /
• 2004

The purpose of this study is to understand what kind of effects a local residents’ participation on a local environmental problem has on the Environmental consciousness of the resident, and on the local community. I (researcher) employed qualitative research methods on the residents' environmental movement, which claimed to preserve the Sung Mi Mountain from the Seoul City Hall's plan of the water reservoir construction. I tried to understand the participation motivation and participating actions, and also the changes and effects the participation brought at both a personal, and community level. The data were gathered by means of in-depth interview with the local residents and unstructured questionnaire. At first, through the residents' environmental movement, the participants acquired a growth in environmental consciousness. For example, they obtained better understanding of the environment, change of attitude to environment, and participation function. Secondly, it is meaningful that a local tie intervened by the environment, enforced self-governing, and shows how community sentiment plays an important role for local community organization. Moreover, the environmental movement contributed to developing a ‘culture for participation’. In conclusion, participating in a local environmental problem can be an integration of learning and practice and also leads to reflective thinking about the relationship not only between human beings and nature, but also among human beings. In addition, it can buildup a systemic cooperation for local problem-solving and the ability to make an alternative culture in the community. These are the significances of the local environmental problem-participation on the environmental education.