• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.142-146
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• 2017

지진해일의 수리특성을 분석하기 위하여 유사한 파형특성을 가진 고립파를 많이 이용하고 있다. 그러나 고립파의 근사파형은 실제 지진해일에 비해 상당히 좁은 파형분포를 가지고 있다. 이에 수치모의에서는 기존의 고립파 근사식을 개량하여 고립파형의 지진해일을 수치적으로 생성하고 있다. 본 연구에서는 지진해일의 파형분포에 따른 월파특성을 수치적으로 조사하기 위하여 개량된 고립파 근사식을 2차원 N-S solver에서 적용하였다. 이것에 기초하여 수치파동수조에 직립호안과 그 배후에는 월파수조를 설치하고, 지진해일 월파량을 측정하였다. 수치해석결과로부터 직립호안 주변의 공간파형과 마루 위의 유속분포로부터 파형분포에 따른 월파현상을 분석할 수 있었다. 또한 기존 고립파 근사이론 대비 개량된 고립파의 체적비에 따른 월파량 변화를 정량적으로 조사하였다. 그 결과 지진해일의 체적비가 증가할수록 월파량이 거의 선형적으로 증가하는 경향을 나타내었다.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.2
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• pp.154-161
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• 1998

Prototypes of a design are always needed for the purpose of visualization and evaluation in the aspect of manufacturability functionality, and aesthetic appearance. Since the prototyping process requires a significant amount of cost and time, various rapid prototyping processes are recently being introduced in the process. However, it is usually necessary for a part built up by a rapid prototyping system to be refined by a post-processing process, in which the stair steps on the surfaces, the support structures (if they exist), and the unprocessed material are eliminated. This post-processing is usually done manually and is a time-consuming task. Especially, eliminating the trapped volumes, the volume of the unprocessed material entrapped by the solidified portion, is sometimes impossible in some processes. This study provides a designer with a tool to detect the existence and to calculate the quantity of the trapped volumes at the given build-up direction, so that the proper build-up direction is chosen or the part is built by pieces to avoid the problems caused by the trapped volumes in advance. Since the proposed algorithm can efficiently calculate the amount of the trapped volumes at any build-up direction, it has the potential of such application as optimizing the build-up direction to minimize the trapped volumes.

• Tunnel and Underground Space
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• v.33 no.2
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• pp.71-82
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• 2023

This study presents a direct measurement method for grain bulk modulus, which is important hydraulic-mechanical properties of rock, and conducts the experiment to investigate the grain bulk modulus of sandstone. In addition, the factors affecting the grain bulk modulus were investigated, comparing volumetric characteristics of rocks with different properties. As a result of the experiment, it was confirmed that the theoretically estimated bulk modulus is overestimated than the direct measured one. The possibility of the difference was analyzed, discussing the existence of non-connected pore space due to particle structure of the rock. Finally, the experimental results showed that the direct measurement suggested in this study can reliably predict the grain bulk modulus of sandstone.

• Transactions of the Korean Society of Mechanical Engineers
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• v.9 no.3
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• pp.287-294
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• 1985

본 연구에서는 충격하중하에서 충격파괴거동에 미치는 모상입경과 제2상 형태 의 영향을 분석, 검토하기위해서, 화학성분, 마르텐사이트체적율, 연결도, 강도비등을 되도록 일정하게 하고, 우선 모상입경과 제2상의 형태(연결재와 고립재)를 변화시켜, 충격속도를 달리하였을때 얻어지는 충격하중-시간유선을 토대로하여 충격강도, 하중작 용시간, 흡수에너지 및 연성파괴거동을 고찰하였다.

• Journal of Korea Water Resources Association
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• v.37 no.10
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• pp.845-855
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• 2004

The propagation and associated run-up process of nearshore tsunamis in the vicinity of shorelines have been analyzed by using a two-dimensional numerical model. The governing equations of the model are the nonlinear shallow-water equations. They are discretized explicitly by using a finite volume method and the numerical fluxes are reconstructed with a HLLC approximate Riemann solver and weighted averaged flux method. The model is applied to two problems; The first problem deals with water surface oscillations, while the second one simulates the propagation and subsequent run-up process of nearshore tsunamis. Predicted results have been compared to available analytical solutions and laboratory measurements. A very good agreement has been observed.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1376-1380
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• 2004

본 연구에서는 홍수범람지도 제작을 위해 사용되는 수치모형의 검증을 수행하고자 한다. 검증할 수치모형은 스위스의 Beffa에 의해 개발된 FLUMEN(FLUvial Modeling ENgine)으로서 수심 적분된 2차원 비선형 천수방정식에 불규칙 심각망을 이용한 유한체적법(finite volume method)이 적용된 수치모형이며 스위스, 독일, 오스트리아 등에서 홍수범람해석에 사용된 바 있는 모델이다. FLUMEN 모형의 검증을 위하여 범람해석시 가장 중요한 문제인 이동경계조건(moving boundary condition)을 포함하고 있는 원형섬에서의 고립파에 처오름높이를 계산하여 수리모형실험 결과와 비교한다. 수리모형실험은 미국 육군 공병단 산하의 해안공학연구소(CERC, Coastal Engineering Research Center)에서 수행되었으며(Liu 등, 1995) 수조의 중앙에 높이 0.625m, 해저지름 7.2m, 경사각 $14.04^{\circ}$의 원형섬이 위치한다. 본 연구 결과, 수치해석으로 계산된 섬에서의 실제 처오름높이와 입사파의 파고의 비(R/A)는 수리모형실험의 결과와 어느 정도 일치하였다.

• Journal of Korea Water Resources Association
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• v.51 no.8
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• pp.643-654
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• 2018

In order to generate the stable tsunami in a numerical wave tank, a two-dimensional numerical model, LES-WASS-2D has been introduced the non-reflected wave generation system for various tsunami waveforms. And then, comparing to existing experimental results it is revealed that computed results of the LES-WASS-2D are in good agreement with the experimental results on spatial and temporal tsunami waveforms in the vicinity of a seawall. It is shown that the applied model in this study is applicable to the numerical simulations on tsunami overtopping and inundation. Using the numerical results, the characteristics of overtopping and inundation on a seawall are also discussed with volume ratio of tsunami and relative tsunami height. The wider the tsunami waveform, tsunami overtopping quantity and inundation distances are linearly increased. Therefore, the hydraulic characteristics is highly likely to be underestimated against the real tsunami if the solitary wave of approximation theory is applied for the overtopping/inundation simulations due to a tsunami.

• Journal of the Korean Magnetics Society
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• v.2 no.2
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• pp.114-118
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• 1992

아크로를 이용하여 제작한 NdF $e_{12-x}$ $Ti_{x}$ (1 .leq. x .leq. 2) 합금의 상분석 결과 이들 합금은 ThM $n_{12}$ 구조의 경자성상(1-12상) 과 반강자성의 F $e_{2}$Ti 및 연자성의 .alpha. -Fe 등으로 구성되며, x=1.3 인 NdF $e_{10.7}$ $Ti_{1.3}$ 조성에서 단상에 가까운 ThM $n_{2}$ 구조가 얻어짐이 밝혀졌다. 한편, 합금중의 1-12 상은 50 .mu. m - 100 .mu. m 의 사각주 형태로 생성되며, FeTi은 1-12상의 결정립계에 고립된 입자의 형태로 존재한다. NdF $e_{10.7}$ $Ti_{1.3}$ 합금을 질화처리할 경우 단위포의 체적, 자화, 이방성자장 및 큐리온도가 증가하며, 이합금을 500 .deg. C 에서 15분간 질화처리한 NdF $e_{10.7}$ $Ti_{1.3}$ $N_{x}$ 의 비포화자화, 이방성자장 및 큐리온 도는 각각, .sigma. $_{s}$ =128 A $m^{2}$/kg $H_{A}$=6400 kA/m (80 kOe) 및 Tc=470 .deg. C로 질화처리 전에 비하여 크게 증가한다.크게 증가한다. 증가한다.

• Journal of Korean Philosophical Society
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• v.123
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• pp.57-86
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• 2012

Many contemporary philosophers argue that modern philosophy is only the philosophy being imprisoned in subject and consciousness without communicating other subjects with language. They criticize that it is solipsistic. Today, those who are taking part in the communication theory, hermeneutics, and de-constructivism are trying to overcome this problem. The practical philosophers, especially those who advocate communintarianism criticize that modern libertarianism is not free from the isolated autonomy and breaks the solidarity of the traditional community with treating formally others. They criticize Kant's philosophy in the same way. But it is unreasonable. Because Kant was not the philosopher who pursued the same philosophy of subjectivity and liberalism as the earlier modern philosophers pursued. He tried to criticize its limits and overcome them. Especially he did not remain within the modern subjectivity, but rather tried to come up with the inter-subjectivity communicating between subjects. He showed this side through the 'sensus communis'. He thought of a judgement of taste as an effect resulting from the free play between imagination and understanding, and postulated the 'sensus communis' as a ground of the universal validity of this judgement. Therefore this 'sensus communis' is the subjective principle of a judgement of taste. Furthermore, he did not treat this 'sensus communis' merely as a self-relation of a subject, but rather developed it into an communicative relation among subjects. This position of Kant enables us to seek the harmony between the aesthetic sphere and social-moral sphere, and to overcome the conflicts between the autonomy of the liberalism and the solidarity of the communitarianism. Especially, his 'sensus communis' can be developed into the 'critical hermeneutics' and the 'relational autonomy'. Therefore his 'sensus communis' has the possibility to overcome the negative points of the traditional community and the modern community, and to overcome the conflicts among the isolated selves occurring in today's society. Hence Kant's 'sensus communis' has still the important values in the contemporary philosophy, especially in the practical philosophy being now discussed over the relation between autonomy and solidarity.

• Journal of the Korean Geographical Society
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• v.49 no.6
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• pp.949-969
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• 2014

The purpose of this study is to analyze the share of global citizenship education in the 2009 Revised Social Studies (geography area) School Curriculum of the Republic of Korea. I selected the achievement standards of the geography domain in the fifth and sixth grades as the subjects of analysis. The chosen subjects were examined using content analysis: I used KrKwic, a Korean language content analysis tool, to analyze the content and drew a semantic network of the analysis results using UciNet/NetDraw. I found that the geography domain of the 2009 Revised Primary School Curriculum included the concepts of and factors of global citizenship education. However, global citizenship education did not account for a major portion of the curriculum, and the curriculum achievement standards were noticeably nation-state centered. Global citizenship education factors were not closely associated with to other related factors in fact, they even revealed a isolated pattern. These findings suggest that the inclusion of global citizenship education in primary geography education is limited, because the connections between global citizenship education and related contents, such as the environment, sustainable development, conflict, and cooperation, are probably impeded. Globalization accompanies the transformation of territories, identities, and the relations between nation-states and the world, although nation-states continue to play a significant role in the globalized worlds. Therefore global citizenship education, a educational trend focusing on the global community, is particularly important and is required in the geography curriculum of the global era. I expect that the examination undertaken in this study to contribute to future curriculum revisions regarding globalizatin and global citizenship.