• International Journal of Air-Conditioning and Refrigeration
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• 제9권1호
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• pp.65-70
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• 2001

During the summer season, it is very hot and humid in Korea. So the humidity is an important factor regarding the environmental control function of building envelops. The purpose of this research is to measure and analyze the characteristics of such environmental factors as relative humidity, dry bulb temperature and air velocity varies both in the clay and cement envelop structures using granite dome models during the summer time. The interior relative humidity of the clay model is constant regardless of exterior humidity although a little range of variation is shown in comparison to the cement model.

• 생물환경조절학회지
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• 제3권1호
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• pp.10-19
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• 1994

Wind load is known to be one of major forces to influence the stability of agricultural structures. General flow fields were calculated to determine flow characteristics over the envelop of the following three types of greenhouses with arched roof : single span, twin span greenhouses, and two single span greenhouses apart 3m inbetween. Pressure coefficients along the envelop of greenhouse were numerically calculated by the k-$\varepsilon$ turbulence model, which lead to determine wind forces on it. Curvilinear coordinate for an arched roof and the upwind scheme were adopted for the study. The calculated pressure coefficients were validated with the avaliable data of Japanese Standard and NGAM Standard. The Magnitude of calculated forces over the envelop was not in good accordance with data except the windward wall. Even tile data of Japanese and NGAM Standard for validation deviated a lot from each other in quantity and quality. Such discrepancy may be attributed to different geometric and/or flow configuration conditions for experiments, or the insenstivity of the k-$\varepsilon$ turbulence model to recirculation flow.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1997년도 토목섬유 학술발표회 논문집
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• pp.21-30
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• 1997

• 건축역사연구
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• 제14권3호
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• pp.89-102
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• 2005

Frank Lloyd Wright and Mies van der Rohe are two of the most influential architects in modern architecture. In spite of the different values in their architectural lives, the design of high-rise building had been a continuous matter of primary concern for them. The purpose of this study is to compare the architectural characteristics of the two master architects in terms of building form, structure, function, and envelop skin. glass. Both of them shared with the principle of organic architecture even in the design of high-rise buildings. However, the specific approaches to realize it in high-rise buildings are significantly different. Although they emphasized the integration of building form and structure, Wright regarded the reinforced concrete structure as an organic form-giver, while Mies introduced the steel skeleton structure only as an efficient and flexible building frame. As primary finishing materials for high-rise buildings, glass was used for functional purpose by Wright, but for visual purpose by Mies.

• 한국전자파학회논문지
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• 제19권5호
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• pp.547-555
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• 2008

본 논문에서는 linear amplification with nonlinear components(LINC) 시스템의 두 신호 경로에 발생하는 크기와 위상 오차를 자동으로 검출하여 보상하는 알고리즘을 제안하였다. LINC 시스템은 첨두 대 평균 전력비가 큰 non-constant envelop 신호를 constant envelop 신호로 바꿔주어 고효율 전력 증폭기를 사용할 수 있는 장점이 있다. 그러나 LINC 시스템은 두 전력 증폭기의 경호에서 발생하는 매우 작은 경로 오차에 민감하게 성능이 열화된다는 단점이 있다. 본 논문에서는 4개의 테스트 신호를 이용하여 두 경로의 크기와 위상 오차를 검출하는 알고리즘을 제안하였다. 제안된 오차 검출 기법은 닫힌 해(closed form solution)를 가지며, 반복 계산이 필요하지 않아, 빠르고 효율적으로 오차를 검출할 수 있다. 본 논문에서는 제안된 기법을 적용하여 오차 검출과 검출된 결과를 반영하여 신호의 왜곡을 보상하는 digital-IF 형태를 갖는 LINC 시스템을 구현하였다. 구현된 LINC 시스템은 7 MHz 채널 대역을 갖고 16-QAM으로 변조된 IEEE 802.16 WiMAx 기저 대역 신호를 이용하여 성능을 분석하였으며, 제안된 기법을 이용하여 EVM이 -37.37 dB까지 개선되었으며, 이로서 LINC 시스템 구현시 제안된 오차 검출 및 보상 기법의 적용 타당성을 확인하였다.

• 통합자연과학논문집
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• 제6권4호
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• pp.197-204
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• 2013

The crystal structure of the potential active 4,6-dimethyl-9-phenyl-8,12-dioxa-4,6-diazatetracyclo [8.8.0.02,7.013,18] octadeca-2(7),13,15,17-tetraene-3,5,11-trione 2-ethoxyphenyl (2E)-but-2-enoate ($C_{22}H_{18}N_2O_5$) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the monoclinic space group $P_12_1/c_1$ with unit cell dimension a=15.2039(8), b=12.3888(6) and c= 9.8162(5) [alpha & $gamma=90^{\circ}$ beta=98.113(2)]. In the structure fused pyrone and pyran rings each adopt a sofa/envelop conformation. The crystal structure is stabilized by intramolecular C-H... O hydrogen bond interaction.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.661-668
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• 2007

In this paper, excitation systems using linear mass shaker (LMS) are presented in order to simulate the wind induced responses of a building structure. The actuator force for the excitation systems is calculated by using the inverse transfer function of a target structural response to the actuator. Filter and envelop function are used such that the error between the wind and actuator induced responses is minimized by preventing the actuator from exciting unexpected modal response and initial transient response. The analyses results from a 76-story benchmark building problem in which wind load obtained by wind tunnel test is given, indicate that the excitation system installed at a specific floor can approximately embody the structural responses induced by the wind load applied to each floor of the structure. The excitation system designed by the proposed method can be effectively used for evaluating the wind response characteristics of a practical building structure and for obtaining an accurate analytical model of the building under wind load.

• Smart Structures and Systems
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• 제4권1호
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• pp.85-98
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• 2008

In this paper, excitation systems using a linear mass shaker (LMS) and an active tuned mass damper (ATMD) are presented to simulate the wind induced responses of a building structure. The actuator force for the excitation systems is calculated by using the inverse transfer function of a target structural response to the actuator. Filter and envelop functions are used to prevent the actuator from exciting unexpected modal responses and an initial transient response and thus, to minimize the error between the wind and actuator induced responses. The analyses results from a 76-story benchmark building problem for which the wind load obtained by a wind tunnel test is given, indicate that the excitation system installed at a specific floor can approximately reproduce the structural responses induced by the wind load applied to each floor of the structure. The excitation system designed by the proposed method can be effectively used for evaluating the wind response characteristics of a practical building structure and for obtaining an accurate analytical model of the building under wind load.

• 한국음향학회지
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• 제20권1호
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• pp.68-76
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• 2001

유한요소법을 이용하여 압전 수중음향센서의 모델링 및 음향특성을 해석하였다. 압전 수중음향센서의 해석에서 기본적인 압전-탄성 구조물과 유체-구조물의 연성해석을 위한 유한요소 정식화를 하였으며 무한영역의 음향유체를 처리하기 위하여 IWEE (Infinite Wave Envelop Element)를 도입하였다. Tonpilz형 수중음향센서를 수중 산란체로 볼 경우 입사파가 산란체의 표면을 가진할 때 산란체로부터 발생되는 산란파는 IWEE로 인하여 무한 유체영역에서의 산란파의 감소특성을 갖게 되어 무한영역을 유한영역으로 나눈 인위적인 경계에서 반사가 일어나지 않게 되므로 산란파의 음압을 정확히 구할 수 있었다. 또한, 이러한 산란해석을 바탕으로 입사파에 대한 음향센서 내부의 전기적 응답특성인 RVS (Receiving Voltage Signal)를 구하였다. 이러한 일련의 연구 과정들은 소나 시스템을 정확히 해석하고 음향특성을 예측하는데 큰 도움이 될 것이다.

• ETRI Journal
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• 제34권1호
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• pp.114-117
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• 2012

A small-sized ($15mm{\times}30mm$) planar monopole MIMO antenna that offers high-isolation performance is presented in this letter. The antenna is miniaturized using inductive coupling within a meander-line radiator and capacitive coupling between a radiator and an isolator. High isolation is achieved by a T-shaped stub attached to the ground plane between two radiators, which also contributes to the small size using a folded structure and the capacitive coupling with radiators. The proposed antenna operates for the WLAN band within 2.4 GHz to 2.483 GHz. The measured isolation (S21) is about -30 dB, and the envelope correlation coefficient is less than 0.1.