• Title/Summary/Keyword: 주기 경계조건

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Effects of Ocean Outfall for Elimination of the Anoxic Layer in Youngsan River Estuary (영산강 하구언에서 저 산소 층의 제거를 위한 해양방류구의 효과)

  • Kwon, Seok-Jae;Cho, Yang-Ki;Seo, Uk-Won
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.17 no.4
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    • pp.259-268
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    • 2005
  • There has been a growing interest in the elimination of anoxic layer in the Youngsan River Estuarybecause the anoxic water mass caused mainly by the inflow of fresh water from the sea wall might cause the mass reduction of benthos during summer. An ocean outfall system to discharge treated wastewater into sea water may be used as one of the effective and economical ways to eliminate the anoxic layer. The suitable ocean outfall design is generally proposed for the prediction of the buoyant jet behavior in the near field. The parameters including CTD and current data are taken into account f3r more reliable buoyant jet behavior calculation. One of the numerical models, CORMIX 1, approved by EPA is used herein for the prediction of the trajectorial variation of the cross-sectional salinity and DO concentration distribution on the calculated buoyant jet boundary according to the tidal periods. On the basis of the results, it is suggested that the single port outfall is a useful system to eliminate the anoxic layer. Proper strategies are also proposed for achieving desirable ambient conditions.

Zwei Perspektiven für die Kunst - Kants Ästhethik des Empfangenden und Nietzsches Physiologie der Kunst - (예술에 대한 두 가지 태도 - 칸트의 수용미학과 니체의 예술생리학 -)

  • Chung, Nak-rim
    • Journal of Korean Philosophical Society
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    • v.130
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    • pp.277-304
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    • 2014
  • Der vorliegende Beitrag zielt darauft ab, zwei Perspektiven $f{\ddot{u}}r$ die Kunst bei Kant und Nietzsche und ihre Schlussfolgerungen zu $er{\ddot{o}}rtern$. Kants Kritik der Urteilskraft hat eine enorme Rolle in der Geschichte der ${\ddot{A}}sthetik$ gespielt. $F{\ddot{u}}r$ Kant sollen ${\ddot{a}}sthetische$ Urteile ebenso wie Erkenntnis- und Moralurteile $allgemeing{\ddot{u}}ltig$ sein, obwohl sie auf einem $pers{\ddot{o}}nlichen$ Geschmack beruhen. Die $Allgemeing{\ddot{u}}ltigkeit$ des $Sch{\ddot{o}}nen$ sei $m{\ddot{o}}glich$, weil sie nicht auf dem Gegenstand, sondern auf dem transzendentalen Subjekt basiere. Die $sch{\ddot{o}}ne$ Kunst als Kunst des Genies soll uns wie die $Natursch{\ddot{o}}nheit$ ohne Interesse wohlgefallen. Nietzsches Stellungnahme zu Kants ${\ddot{A}}sthetik$ ist sehr kritisch. Nietzsches erster Kritikpunkt richtet sich gegen das 'interesselose Wohlgefallen'. Gegen Kant behauptet Nietzsche, dass die $Sch{\ddot{o}}nheit$ sehr wohl mit Interesse verbunden ist. Grund $daf{\ddot{u}}r$ ist, dass das $Sch{\ddot{o}}ne$ wesentlich aus dem Willen zur Macht entspringt. Der zweite Kritikpunk Nietzsches liegt darin, dass in Kants ${\ddot{A}}sthetik$ die Moral im Vordergrund steht. Das $Sch{\ddot{o}}ne$ ist $f{\ddot{u}}r$ Kant durch die Moral gerechtfertigt. Nietzsche dreht diese Stellung der Moral zur Kunst um. Der dritte Kritikpunkt Nietzsches ist, dass Kant statt von der Erfahrung des $K{\ddot{u}}nstlers$ (Schaffenden) aus das ${\ddot{a}}sthetische$ Problem zu betrachten, allein vom Zuschauer (Empfangenden) aus ${\ddot{u}}ber$ die Kunst und das $Sch{\ddot{o}}ne$ nachgedacht habe. $F{\ddot{u}}r$ Nietzsche ist die Kunst $prim{\ddot{a}}r$ vom $K{\ddot{u}}nstler$ aus zu verstehen. Nietzsches Physiologie der Kunst ist mit dem Begriff 'Leib' $verkn{\ddot{u}}pft$, d.h. Nietzsche behauptet, dass physiologische und ${\ddot{a}}sthetische$ Prozesse wesentlich $zusammenh{\ddot{a}}ngen$. Die Schlussfolgerung der Physiologie der Kunst lautet: erstens, jeder Mensch ist $K{\ddot{u}}nstler$, sofern er schaffend ist, und zweitens, die Welt selbst ist nichts als Kunst. Nietzsches Physiologie der Kunst hat einen $gro{\ss}en$ Einfluss auf die $gegenw{\ddot{a}}rtige$ Kunst $ausge{\ddot{u}}bt$ und kein anderer Philosoph hat auf die $gegenw{\ddot{a}}rtige$ Kunst nachaltiger gewirkt.

Grand Circulation Process of Beach Cusp and its Seasonal Variation at the Mang-Bang Beach from the Perspective of Trapped Mode Edge Waves as the Driving Mechanism of Beach Cusp Formation (맹방해안에서 관측되는 Beach Cusp의 일 년에 걸친 대순환 과정과 계절별 특성 - 여러 생성기작 중 포획모드 Edge Waves를 중심으로)

  • Cho, Yong Jun
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.31 no.5
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    • pp.265-277
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    • 2019
  • Using the measured data of waves and shore-line, we reviewed the grand circulation process and seasonal variation of beach cusp at the Mang-Bang beach from the perspective of trapped mode Edge waves known as the driving mechanism of beach cusp. In order to track the temporal and spatial variation trends of beach cusp, we quantify the beach cusp in terms of its wave length and amplitude detected by threshold crossing method. In doing so, we also utilize the spectral analysis method and its associated spectral mean sand wave number. From repeated period of convergence and ensuing splitting of sand waves detected from the yearly time series of spectral mean sand wave number of beach cusp, it is shown that the grand circulation process of beach cusp at Mang-Bang beach are occurring twice from 2017. 4. 26 to 2018. 4. 20. For the case of beach area, it increased by $14,142m^2$ during this period, and the shore-line advanced by 18 m at the northen and southern parts of the Mang-Bang beach whereas the shore-line advanced by 2.4 m at the central parts of Mang-Bang beach. It is also worthy of note that the beach area rapidly increased by $30,345m^2$ from 2017.11.26. to 2017.12.22. which can be attributed to the nature of coming waves. During this period, mild swells of long period were prevailing, and their angle of attack were next to zero. These characteristics of waves imply that the main transport mode of sediment would be the cross-shore. Considering the facts that self-healing capacity of natural beaches is realized via the cross-shore sediment once temporarily eroded. it can be easily deduced that the sediment carried by the boundary layer streaming toward the shore under mild swells which normally incident toward the Mang-Bang beach makes the beach area rapidly increase from 2017.11.26. to 2017.12.22.

A Review on Monitoring Mt. Baekdu Volcano Using Space-based Remote Sensing Observations (인공위성 원격탐사를 이용한 백두산 화산 감시 연구 리뷰)

  • Hong, Sang-Hoon;Jang, Min-Jung;Jung, Seong-Woo;Park, Seo-Woo
    • Korean Journal of Remote Sensing
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    • v.34 no.6_4
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    • pp.1503-1517
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    • 2018
  • Mt. Baekdu is a stratovolcano located at the border between China and North Korea and is known to have formed through its differentiation stage after the Oligocene epoch in the Cenozoic era. There has been a growing interest in the magma re-activity of Mt. Baekdu volcano since 2010. Several research projects have been conducted by government such as Korea Meteorological Administration and Korea Institute of Geoscience and Mineral Resources. Because, however, the Mt. Baekdu volcano is located far from South Korea, it is quite difficult to collect in-situ observations by terrestrial equipment. Remote sensing is a science to analyze and interpret information without direct physical contact with a target object. Various types of platform such as automobile, unmanned aerial vehicle, aircraft and satellite can be used for carrying a payload. In the past several decades, numerous volcanic studies have been conducted by remotely sensed observations using wide spectrum of wavelength channels in electromagnetic waves. In particular, radar remote sensing has been widely used for volcano monitoring in that microwave channel can gather surface's information without less limitation like day and night or weather condition. Radar interferometric technique which utilized phase information of radar signal enables to estimate surface displacement such as volcano, earthquake, ground subsidence or glacial movement, etc. In 2018, long-term research project for collaborative observation for Mt. Baekdu volcano between Korea and China were selected by Korea government. A volcanic specialized research center has been established by the selected project. The purpose of this paper is to introduce about remote sensing techniques for volcano monitoring and to review selected studies with remote sensing techniques to monitor Mt. Baekdu volcano. The acquisition status of the archived observations of six synthetic aperture radar satellites which are in orbit now was investigated for application of radar interferometry to monitor Mt. Baekdu volcano. We will conduct a time-series analysis using collected synthetic aperture radar images.

Dynamic response of segment lining due to train-induced vibration (세그먼트 라이닝의 열차 진동하중에 대한 동적 응답특성)

  • Gyeong-Ju Yi;Ki-Il Song
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.25 no.4
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    • pp.305-330
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    • 2023
  • Unlike NATM tunnels, Shield TBM tunnels have split linings. Therefore, the stress distribution of the lining is different even if the lining is under the same load. Representative methods for analyzing the stress generated in lining in Shield TBM tunnels include Non-joint Mode that does not consider connections and a 2-ring beam-spring model that considers ring-to-ring joints and segment connections. This study is an analysis method by Break-joint Mode. However, we do not consider the structural role of segment lining connections. The effectiveness of the modeling is verified by analyzing behavioral characteristics against vibration loads by modeling with segment connection interfaces to which vertical stiffness and shear stiffness, which are friction components, are applied. Unlike the Non-joint mode, where the greatest stress occurs on the crown for static loads such as earth pressure, the stress distribution caused by contact between segment lining and friction stiffness produced the smallest stress in the crown key segment where segment connections were concentrated. The stress distribution was clearly distinguished based on segment connections. The results of static analysis by earth pressure, etc., produced up to seven times the stress generated in Non-joint mode compared to the stress generated by Break-joint Mode. This result is consistent with the stress distribution pattern of the 2-ring beam-spring model. However, as for the stress value for the train vibration load, the stress of Break-joint Mode was greater than that of Non-joint mode. This is a different result from the static mechanics concept that a segment ring consisting of a combination of short members is integrated in the circumferential direction, resulting in a smaller stress than Non-joint mode with a relatively longer member length.