• Title/Summary/Keyword: Half Space

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A Study on the Change of Concept in Architectural Space following the Aesthetic Cognition of Space (미학적 공간인식에 따른 건축공간개념의 변화에 관한 연구)

  • 이용재;윤도근
    • Korean Institute of Interior Design Journal
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    • no.16
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    • pp.22-28
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    • 1998
  • The purpose of this study is to analyze the architectural space of modern and contemporary architecture which has been changed by the aesthetic cognition on space. The intention of considering architectural space aesthetically is to convert the viewpoint of seeing space as simple physical structure into different viewpoint of regarding 'space' as 'cultural place' However this does not means to apply aesthetic theory to architectural space. The aesthetic cognition on space is one of the main subjects of the expression of art from ancient to today however the appearance of space concept as architectural aesthetics accelerated by G. Semper theory after the latter half of 19th century. On the standpoint of perpetuity in architecture the aesthetics of scientific rationalism in modernism based on the reasonable thinking regards the variety of inherent characteristic in architectural space as 'Transferential Space'. On the other hand, in regarding to architectural trend, the nature in architectural space has been considered as 'Existential Space' starting from the conscious construction of environments to help human existence in the existentialism. The Conclusion logic of follows as belows; first, the concept of space structure in architecture has been exchanged from Enclosed Space to Topological Space. Second, the concept of architectural space has been changed and developed to the Deterministic, Profound, Dissipative, and Recognizable Space according to the change of expression in architecture.

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Appropriate Block Level in Neurolytic Lumbar Sympathetic Ganglion Block (신경파괴적 요부교감신경절 차단의 적정 부위)

  • Kim, Hee-Jung;Lee, Cheol-Oh;Shin, Yang-Sik;Lee, Youn-Woo
    • The Korean Journal of Pain
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    • v.14 no.2
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    • pp.199-206
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    • 2001
  • Background: The lumbar sympathetic ganglia are variable in both position and numbers. The aim of this study was to detect the appropriate lumbar vertebral level where the lumbar sympathetic ganglia primarily aggregate. Methods: Forty patients comprising of hyperhidrosis (26 cases), complex regional pain syndrome (10 cases), peripheral artery occlusion disease (3 cases) and postherpetic neuralgia (1 case) underwent lumbar sympathetic block. We randomly selected one of two (L2 or L3) levels and the L4 level. The position of the needle tip and distribution of dye was verified by injection of a mixture of radio-opaque dye (1.5 ml) and 4% lidocaine (1.5 ml) and subsequently confirmed by L-spine anteroposterior and a lateral view X-ray. We considered the response positive when the skin temperature increased more than $1^{\circ}C$ in 5 min. Results: In general, the positive response ratio was greater when the needle tip located at the L2 or L4 level vice L3 and when the drug was distributed on the lower half of the L4 body and in the L4/5 intervertebral disc space. In a right side block, the positive response ratio was greater when the drug was distributed on the lower half of the L4 body and in the L4/5 intervertebral disc space, although in a left side block there was no significant difference seen between the levels. The complications of the neurolytic block were alcohol neuritis (7.5%) and hypoesthesia (5%) on the L1 or L2 dermatome. Conclusions: The best effect with least chance of complication may be induced by spreading the drug on the lower half of the L4 body and/or into the L4/5 intervertebral disc space by placing the needle tip on the L4 body.

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Time-Domain Solutions of the VV, HV, VH Problems at the Surface of a Normally Uniaxial Half-Space Dielectric (수직 단축성을 갖는 반공간 유전체 표면에서 VV, HV, VH 문제의 시간영역 해)

  • Lihh Won-Seok;Nam Sang-Wook
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.12 s.103
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    • pp.1246-1254
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    • 2005
  • Theoretical investigation is made on the electromagnetic fields generated by an impulsive point current source, fur the VV, HV, and VH problems at the interface between an isotropic upper half-space medium and a normally uniaxial lower half-space medium. The electric fields of these problems are associated only with the extraordinary-wave components in the Fourier-Laplace domain. Applying the Cagniard-de Hoop method to each problem, the time-domain solutions of the wave fields are obtained. The fields of the VV case can be expressed in explicit(integral-free) forms. The fields of the HV and VH cases are not integral-free, but the major singularities implicit in the integral solutions can be analytically extracted. The interfacial far fields in the frequency domain are determined by the singularities in the time domain.

Seismic Response Analysis Method for 2-D Linear Soil-Structure Systemsusing Finite and Infinite Elements (유한요소와 무한요소를 사용한 2차원 선형 지반-구조물계의 지진응답해석법)

  • 김재민;윤정방;김두기
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.13 no.2
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    • pp.231-244
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    • 2000
  • This paper presents a dynamic analysis technique for a 2-D soil-structure interaction problem in the frequency domain, which can directly be applied as an analysis tool for seismic response analyses of underground structures, tunnels, embankments, and so on. In this method, the structure and near-field soil is modeled by the standard finite elements, while the unbounded far-field soil is represented using the dynamic infinite elements in the frequency domain. The earthquake-input motion is regarded as traveling P and SV waves which are incident vertically from the far-field of underlying half-space to the near-field of layered medium. The equivalent earthquake forces are then calculated utilizing so-called fixed-exterior-boundary-method and the free-field responses including displacements and tractions. For the verification of the present study, seismic response analyses are carried out for a multi-layered half-space free-field soil medium and a cylindrical cavity embedded in a homogeneous half-space. Comparisons of the present results with solutions by other approaches indicate that the proposed methodology gives accurate estimates. Finally, an application example of seismic response analysis for a subway station is presented, which demonstrates the applicability of the present study.

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Continuous Half Passive Motion under Distracted External Fixation for the Treatment of Distal Tibial Pilon Fractures (신연 외고정 및 지속적 반수동 운동을 이용한 경골 원위부 필론 골절의 치료)

  • Bae, Su-Young;Chung, Hyung-Jin;Shin, Yong-Woon;Park, Jae-Gu
    • Journal of Korean Foot and Ankle Society
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    • v.14 no.2
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    • pp.146-150
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    • 2010
  • Purpose: Pilon fracture has several serious complications such as joint stiffness, arthrosis and delayed angular deformity. We report short-term results of new treatment modality using distracted dynamic external fixators and early controlled ankle motion. Materials and Methods: Eight cases of severe pilon fractures for which we tried small plate fixation and additional distracted dynamic external fixators from July 2007 to June 2009 were included. Half passive continuous ankle joint motion was allowed under free hinged ring fixators after the operation. The external fixators were removed after two or three months from the surgery. We investigated joint space by radiograph, joint pain, range of motion, patient's satisfaction of treatment protocol. Results: Joints were distracted when external fixators were applied and mean 28% of space loss developed after removal of external fixators. In most of cases, satisfactory alignments were maintained. Regarding range of joint motion, mean dorsiflexion angle was 15 degrees and mean plantarflexion angle was 32 degree in the condition of wearing external fixators. There was mean 8% reduction of range of motion but no further progression of ankle stiffness after removal of external fixators. Dorsiflexion was not improved after that, but plantarflexion angle was improved 10% even after removal of external fixators. Patients were generally in compliance with the treatment protocols with high level of satisfaction. Conclusion: We got good results with distracted dynamic external fixators and early continuous half-passive joint motion for pilon fractures in terms of joint pain and range of motion. Therefore we suggest this new protocol as an alternative modality for severe pilon fractures.

Development of Adaptive Optics System for the Geochang 100 cm Telescope

  • Hyung-Chul Lim;Francis Bennet;Sung-Yeol Yu;Ian Price;Ki-Pyoung Sung;Mansoo Choi
    • Journal of Space Technology and Applications
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    • v.4 no.3
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    • pp.185-198
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    • 2024
  • Korea Astronomy and Space science Institute (KASI) partnered with the Australian National University (ANU) to develop the adaptive optics (AO) system at the Geochang observatory with a 100 cm optical telescope for multiple applications, including space geodesy, space situational awareness and Korean space missions. The AO system is designed to get high resolution images of space objects with lower magnitude than 10 by using themselves as a natural guide star, and achieve a Strehl ratio larger than 20% in the environment of good seeing with a fried parameter of 12-15 cm. It will provide the imaging of space objects up to 1,000 km as well as its information including size, shape and orientation to improve its orbit prediction precision for collision avoidance between active satellites and space debris. In this paper, we address not only the design of AO system, but also analyze the images of stellar objects. It is also demonstrated that the AO System is achievable to a near diffraction limited full width at half maximum (FWHM) by analyzing stellar images.

Investigation of PID Fuzzy Controller for Output Voltage Regulation of Current-Doubler-Rectified Asymmetric Half-Bridge DC/DC Converter

  • Chung, Gyo-Bum
    • Journal of Power Electronics
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    • v.7 no.1
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    • pp.21-27
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    • 2007
  • This paper investigates a PID fuzzy controller for output voltage regulation of a current-doubler-rectified asymmetric half-bridge (CDRAHB) DC/DC converter. The controller is a PD-type fuzzy controller in parallel with a linear integral controller. The PD type fuzzy controller is for providing the varying gain at the different operating conditions to regulate the output voltage. The linear integral controller is for removing the steady-state error of the output voltage. In order to show the outstanding dynamic characteristics of the proposed controller, PSIM simulation studies are carried out and compared to the results for which the conventional loop gain design method is used.

Analytical solution for steady seepage and groundwater inflow into an underwater tunnel

  • Zou, Jin-feng;Wei, An;Liang, Li
    • Geomechanics and Engineering
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    • v.20 no.3
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    • pp.267-273
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    • 2020
  • Solutions of the water pressure and groundwater inflow distribution along the tunnel perimeter in a half-infinite aquifer were investigated considering the conditions of the constant head and constant water pressure. It is assumed that the circular tunnel is buried in a fully saturated, homogeneous, isotropic and half-infinite space. Coordinate transformation technique was adopted, the problem of solving the control equations of water pressure in the Cartesian coordinate was transformed to that in the bipolar coordinate system, which can significantly simplify the derivation procedure of the water pressure and inflow distribution. The validation results show the accuracy and advantage of the proposed approach.

A Study on the correlation between underground structure and tumulus of the Royal Tomb in the Joseon Dynasty (조선후기 회격릉의 지하구조를 반영한 봉릉의 시공과 형식)

  • Shin, Ji-Hye
    • Journal of architectural history
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    • v.29 no.2
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    • pp.19-30
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    • 2020
  • In the early of Joseon Dynasty, Royal Tomb developed from stone chamber tomb to lime chamber tomb through precedents. The lime chamber tomb consists of main-chamber(JeongGwang) and sub-chamber(ToeGwang). This separation makes character to construct tumulus of the Royal Tomb half and half. By this character, the Royal Tomb are not constructed by separate structure but constructed by coadjustment. The underground structure and tumulus of the Royal Tomb affect each other in the size and method of construction. The selecting type of Royal Tomb is generally made decision through terrain and politics. This study prove the architectural structure is also one of the major cause the that select type of Royal Tomb.

Application of Fuzzy Integral Control for Output Regulation of Asymmetric Half-Bridge DC/DC Converter with Current Doubler Rectifier

  • Chung, Gyo-Bum;Kwack, Sun-Geun
    • Journal of Power Electronics
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    • v.7 no.3
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    • pp.238-245
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    • 2007
  • This paper considers the problem of regulating the output voltage of a current doubler rectified asymmetric half-bridge (CDRAHB) DC/DC converter via fuzzy integral control. First, we model the dynamic characteristics of the CDRAHB converter with the state-space averaging method, and after introducing an additional integral state of the output regulation error, we obtain the Takagi-Sugeno (TS) fuzzy model for the augmented system. Second, the concept of parallel distributed compensation is applied to the design of the TS fuzzy integral controller, in which the state feedback gains are obtained by solving the linear matrix inequalities (LMIs). Finally, numerical simulations of the considered design method are compared to those of the conventional method, in which a compensated error amplifier is designed for the stability of the feedback control loop.