• 제목/요약/키워드: Under-used Space

검색결과 1,148건 처리시간 0.024초

Optimization of LQR method for the active control of seismically excited structures

  • Moghaddasie, Behrang;Jalaeefar, Ali
    • Smart Structures and Systems
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    • 제23권3호
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    • pp.243-261
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    • 2019
  • This paper introduces an appropriate technique to estimate the weighting matrices used in the linear quadratic regulator (LQR) method for active structural control. For this purpose, a parameter is defined to regulate the relationship between the structural energy and control force. The optimum value of the regulating parameter, is determined for single degree of freedom (SDOF) systems under seismic excitations. In addition, the suggested technique is generalized for multiple degrees of freedom (MDOF) active control systems. Numerical examples demonstrate the robustness of the proposed method for controlled buildings under a wide range of seismic excitations.

설계공간 최적화를 이용한 뼈 성장 모사 (A Simulation Method for Bone Growth Using Design Space Optimization)

  • 장인권;곽병만
    • 대한기계학회논문집A
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    • 제30권6호
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    • pp.722-727
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    • 2006
  • Bone fracture healing is one of the important topics in biomechanics, demanding computation simulations due to the difficulty of obtaining experimental or clinical results. In this study, we adopt the design space optimization method which was established by the authors as a tool for the simulation of bone growth using its evolutionary characteristics. As the mechanical stimulus, strain energy density is used. We assume that bone tissues over a threshold strain energy density will be differentiated and bone tissues below another threshold will be resorbed. Under compression and torsion as loadings, the filling process of the defect is well illustrated following the given mechanical criterion. It is shown that the design space optimization is an excellent tool for simulating the evolutionary process of bone growth, which has not been possible otherwise.

컬러 시각을 이용한 사람 손의 검출 (Human Hand Detection Using Color Vision)

  • 김준엽;도용태
    • 센서학회지
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    • 제21권1호
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    • pp.28-33
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    • 2012
  • The visual sensing of human hands plays an important part in many man-machine interaction/interface systems. Most existing visionbased hand detection techniques depend on the color cues of human skin. The RGB color image from a vision sensor is often transformed to another color space as a preprocessing of hand detection because the color space transformation is assumed to increase the detection accuracy. However, the actual effect of color space transformation has not been well investigated in literature. This paper discusses a comparative evaluation of the pixel classification performance of hand skin detection in four widely used color spaces; RGB, YIQ, HSV, and normalized rgb. The experimental results indicate that using the normalized red-green color values is the most reliable under different backgrounds, lighting conditions, individuals, and hand postures. The nonlinear classification of pixel colors by the use of a multilayer neural network is also proposed to improve the detection accuracy.

반복하중하에서 다보결합부의 역학적 특성 (Mechanical Characteristics of Dowel Joints under Cyclic Loads)

  • 장상식
    • Journal of the Korean Wood Science and Technology
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    • 제23권4호
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    • pp.91-97
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    • 1995
  • Cyclic tests were performed with dowel joints which are being widely used for furniture manufacturing in Korea. In this study, effects of various factors-such as species of joint members, diameter and length of dowels, and space between dowels-on stiffness, strength and damping ratio of joints were evaluated and concluded as follows: 1. Under cyclic loads, failure of dowel joints were caused by bending failure of dowels. 2. Dowel joints were evaluated to be stiff but general load carrying capacities were relatively low. 3. Joint moduli and damping ratios of dowel joints decreased as diameter and length of dowels, and space between dowels increased. 4. In dowel joints, properties of dowel itself have greater effects on stiffness and strength of joints than properties of joint members.

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A Daylight Calculation Method for a Louver System Under the Uniform Sky Condition

  • Kim, Kang-Soo;Hwang, Young-Seok
    • Architectural research
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    • 제1권1호
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    • pp.41-46
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    • 1999
  • The configuration factors in the flux transfer method are applied to calculate daylight factors reaching a station point. To analyze the window equipped with a louver system, geometrical correlation is used for the length shielded by the louver. The space in front of a window is assumed to be an imaginary outdoor space for calculating the luminance of the louver system. The data calculated from this study are compared with SUPERLlTE simulation data and the scale model data. Scale model data are collected on the roof of the Engineering building at Korea University in Seoul under the uniform sky condition.

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Generalized photo-thermal interactions under variable thermal conductivity in a semi-conducting material

  • Aatef D. Hobiny;Ibrahim A. Abbas;C Alaa A. El-Bary
    • Steel and Composite Structures
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    • 제48권6호
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    • pp.641-648
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    • 2023
  • In this article, we explore the issue concerning semiconductors half-space comprised of materials with varying thermal conductivity. The problem is within the framework of the generalized thermoelastic model under one thermal relaxation time. The half-boundary space's plane is considered to be traction free and is subjected to a thermal shock. The material is supposed to have a temperature-dependent thermal conductivity. The numerical solutions to the problem are achieved using the finite element approach. To find the analytical solution to the linear problem, the eigenvalue approach is used with the Laplace transform. Neglecting the new parameter allows for comparisons between numerical findings and analytical solutions. This facilitates an examination of the physical quantities in the numerical solutions, ensuring the accuracy of the proposed approach.

SpaceEye-1 위성의 구조체 설계 및 해석 (Design and Analysis of Structure for SpaceEye-1)

  • 전재성;정수민;최웅;강명석;정연황
    • 한국항공우주학회지
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    • 제43권3호
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    • pp.257-264
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    • 2015
  • 쎄트렉아이에서 개발 한 SpaceEye-1 위성의 구조체는 가혹한 발사 및 궤도 환경에서 다양한 지구 관측 임무를 수행하도록 설계하였다. 본 논문은 SpaceEye-1 위성 개발과정 동안 수행한 구조설계와 해석의 방법론에 대해서 기술하였다. 위성 구조체는 발사환경 하에서 정/동적 하중을 견딜 수 있게 설계하였을 뿐 만 아니라 주 탑재체와 부분체를 보호하도록 설계하였다. 구조 설계 요구사항은 개발 초기부터 발사체, 탑재체와 부분체의 요구사항으로 부터 도출되었다. 3차원 설계는 구조체의 기하학적 적합성을 확인하기 위해 이용되었고, 유한요소해석은 구조체가 발사체와 탑재체로부터 도출 된 기계적인 요구사항을 만족하는지 확인 하는데 적용하였다.

감염병전문병원의 병동부 및 중환자부 영역 구성에 관한 연구 (A Study on the Zoning of Wards and Intensive Care Units (ICUs) in the Infectious Disease Hospital)

  • 이주랑;채철균
    • 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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    • 제29권3호
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    • pp.17-28
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    • 2023
  • Purpose: This study aims to provide basic data for the future construction plans of the Infectious Disease Hospitals by analyzing the area composition and required room ratios in the wards and ICU of currently under-construction infectious disease hospitals. Methods: 3 Methods have been used in this paper. 1) This study conducted a literature review on major considerations and related guidelines for hospitals specializing in infectious diseases using existing data. 2) Based on the objects and activities of the hospital space, zones and areas were set for each department according to infection control. 3) Based on the established zones and areas, basic plan drawings of three hospitals specializing in infectious diseases currently under construction were collected and architectural drawing analysis was performed. Results: 1) Infectious Diseases Hospital must have a spatial organization that can accommodate patient isolation, infection control, efficiency of medical service, and changes. 2) Zones for infection control are divided into negative pressure and non-negative pressure zones based on airborne precaution isolation. It is divided into clean and contaminated zone according to class of cleanliness by Aseptic technique. Areas are classified by objects (patients, healthcare workers, supplies) and activities (access, medical treatment, support), and a system for organizing space is established based on this. 3) By analyzing the area composition of each departmental area, each required room, and each required space in the wards and intensive care units, it provides basic data for the spatial organization for architectural planning of the infectious disease hospital. Implication: It can be used as basic data when planning related facilities by analyzing the characteristics of the space plan of the required room according to the relationship between activities, movement lines, and operation plans based on user behavior.

UV경화성 수지를 이용한 미세패턴 형성에 관한 연구 (A Study on Micro-patterning used the UV-Curable Resin)

  • 남수용
    • 한국인쇄학회지
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    • 제19권2호
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    • pp.68-78
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    • 2001
  • UV-curable resin has the properties of quick-drying, thigh productivity at low temperature, energy savint, space saving, solventless, non-polluting and low-stinking, and thus, UV-curing system has been widely used in the fields of printing inks, adhesives, paints and coating agents. This study has been executed to micro-patterning used UV-curable resin, The micro-patterning properties of this photoresist were investigated under irradiation of UV light low pressure mercury lamp. When the exposed photoresist film was developed by pure water developer, the resolution of this photoresist was about 50$\mu\textrm{m}$.

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Assessment of a Low Power Offset BPSK Component for Spreading Code Authentication

  • Maier, Daniel S.;Pany, Thomas
    • Journal of Positioning, Navigation, and Timing
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    • 제9권2호
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    • pp.43-50
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    • 2020
  • In this paper a low power Spreading Code Authentication (SCA) sequence with a BPSK(1) modulation at a frequency offset of +7.161 MHz is tested for authentication purposes, the Galileo E1OS is used as base signal. The tested signals comprise a Galileo constellation with 5 satellites including the Galileo OS Navigation Message Authentication (OSNMA) and a low power offset BPSK (OBPSK(7,1)) as SCA component. The signals are generated with the software based MuSNAT-Signal-Generator. The generated signals were transmitted Over-The-Air (OTA) using a Software-Defined-Radio (SDR) as pseudolite. With a real-environment-testbed the performance of the SCA in real channel conditions (fading and multipath) was tested. A new SCA evaluation scheme is proposed and was implemented. Under real channel conditions we derive experimental threshold values for the new SCA evaluation scheme which allow a robust authentication. A Security Code Estimation and Replay (SCER) spoofing attack was mimicked on the real-environment-testbed and analyzed with the SCA evaluation scheme. It was shown that the usage of an OBPSK is feasible as an authentication method and can be used in combination with the OSNMA to improve the authentication robustness against Security SCER attacks.