• International Journal of Air-Conditioning and Refrigeration
• /
• v.9 no.1
• /
• pp.65-70
• /
• 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.

• Journal of Bio-Environment Control
• /
• v.3 no.1
• /
• pp.10-19
• /
• 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.

• Proceedings of the Korean Geotechical Society Conference
• /
• 1997.11a
• /
• pp.21-30
• /
• 1997

• Journal of architectural history
• /
• v.14 no.3 s.43
• /
• pp.89-102
• /
• 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.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.19 no.5
• /
• pp.547-555
• /
• 2008

This parer proposed the path mismatch detection and compensation algorithm with closed form for linear amplification with non-linear components(LINC) system implementation. The LINC system has a merit of using the high efficient amplifier by transferring the non-constant envelop signal which is high peak to average signal ratio into constant envelop signal. However, the performance degradation is very sensitive to the path mismatch such as an amplitude mismatch and a phase mismatch. In order to improve the path mismatch, the error detection and compensation method is introduced by the use of four test signals. Since the presented method has the closed form solution, the efficient and fast detection is available. The digital-IF structure of LINC system applied by the proposed error detection and compensation algorithm was implemented. The performance was evaluated with the IEEE 802.16 WiMAX baseband sinal which has 7 MHz channel bandwidth and 16-QAM. The Error Vector Magnitude(EVM) of -37.37 dB was obtained through performance test, which meets performance requirement of -24 dB EVM. As a result, the introduced error detection and compensation method was verified to improve the LINC system performance.

• Journal of Integrative Natural Science
• /
• v.6 no.4
• /
• pp.197-204
• /
• 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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.11a
• /
• pp.661-668
• /
• 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
• /
• v.4 no.1
• /
• pp.85-98
• /
• 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.

• The Journal of the Acoustical Society of Korea
• /
• v.20 no.1
• /
• pp.68-76
• /
• 2001

Sonar is the system that detects objects and finds their location in water by using the echo ranging technique. In order to have excellent performance in variable environment, acoustic characteristics of this system must be analyzed accurately. In this paper, based on the finite element analysis, modeling and analysis of acoustic characteristics of underwater acoustic sensors are preformed. Couplings between piezoelectric and elastic materials, and fluid and structure systems associated with the modeling of piezoelectric underwater acoustic sensors are formulated. In the finite element modeling of unbounded acoustic fluid, IWEE (Infinite Eave Envelop Element) is adopted to take into account the infinite domain. When an incidence wave excites the surface of Tonpilz underwater acoustic sensor, the scattered wave on the sensor is founded by satisfying the radiation condition at the artificial boundary approximately. Based on this scattering analysis, the electrical response of the underwater acoustic sensor under incidence, so called RVS (Receiving Voltage Signal) is founded accurately. This will devote to design Sonar systems accurately.

• ETRI Journal
• /
• v.34 no.1
• /
• pp.114-117
• /
• 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.