• The Pure and Applied Mathematics
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• v.28 no.2
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• pp.155-185
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• 2021

Orders and types of entire functions have been actively investigated by many authors. In this paper, we investigate some basic properties in connection with sum and product of generalized relative order (𝛼, 𝛽), generalized relative type (𝛼, 𝛽) and generalized relative weak type (𝛼, 𝛽) of entire functions with respect to another entire function where 𝛼, 𝛽 are continuous non-negative functions on (-∞, +∞).

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.990-992
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• 2002

30kW electrical power conversion system is delveloped for the variable speed wind turbine system. In the wind energy conversion system(WECS) a synchronous generator with field current excitation converts the mechanical energy into electrical energy. As the voltage and frequency of generator output vary according to the wind speed, a dc/dc boosting chopper is utilized to maintain constant dc link voltage. Grid connection type PWM inverter supply currents into the utility line by regulating the dc link voltage. The active power is controlled by q-axis current which the reactive power can be controlled by d-axis current reference change. The phase angle of utility voltage is detected using s/w PLL(Phased Locked Loop) in d-q synchronous reference frame. This scheme gives a low cost power solution for variable speed WECS.

• Journal of the Earthquake Engineering Society of Korea
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• v.17 no.6
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• pp.293-303
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• 2013

This paper deals with steel braced frame as increasing the lateral strength and ductility in order to seismic retrofit of existing buildings and discusses the designing criteria and calculation method of retrofitted buildings. The addition of steel braced frame can be effective for increasing the lateral strength and ductility of existing buildings. However, There is a problem in utilizing this method. It is the approach to provide an adequate connection between the existing RC frame and the installed steel braced frame, because global strength by failure mode(three type) depends on detail of connection and strength of existing RC frame. So, the designer must be confirmed if it satisfies the required performance or not. Failure mode of type I is the most appropriate for increasing the lateral strength and ductility. Seismic performance evaluation and strength calculation of seismic retrofit are performed by guideline by KISTEC(Korea Infrastructure Safety & Technology)'s "seismic performance evaluation and rehabilitation of existing buildings" and Japan Building Disaster Prevention Association. Buildings are modeled and non-linear pushover analysis are performed using MIDAS program.

• Korean Institute of Interior Design Journal
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• v.25 no.1
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• pp.181-191
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• 2016

The purpose of this study is to analyze affordance of façade design by extracting analysis elements of affordance in façade design domestic five-star hotels. The subjects of this study were 88 domestic five-star hotels; we selected literature review and case study as methodology. The analysis elements included mass forms, exterior colors, window frame patterns, exterior characteristics, and door types based on the visual perception factors of façade design from the concept of affordance. The results of the study were as follows. First, the mass forms were divided into stackable, integral, and connection types, and stackable type was most frequent. Second, exterior colors were divided into achromatic, red, yellow, and opaque color parts, and the achromatic parts were most frequent. Third, the window frame patterns were divided into grid, irregular, full, horizontal, and vertical windows, and grid windows were most frequent. Fourth, the exterior characteristics were divided into formative mass, horizontal partition, design contrast, tiled roof, and facility connection, and the formative mass was most frequent. Fifth, the door types were divided into porch, piloti, and wall type, and porch was most frequent. The results of this study showed that the façade design elements such as mass forms, exterior colors, window frame patterns, exterior characteristics, and door types intentionally contained affordance.

• Journal of the Korean Institute of Gas
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• v.9 no.3 s.28
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• pp.32-37
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• 2005

Hose bands, which are used in LPG (Liquefied Petroleum Gas) or LNG (Liquefied Natural Gas) facilities for home use to join low pressure hoses with fuse-cocks (or regulators), should give a tight connection to prevent a gas leakage from hose connection parts. In this paper, hydraulic pressure tests and pull force tests were carried out to evaluate the performance and swaging length of hose bands. Experimental results showed that the swaging force of ear type bands were higher than those of spring bands and also showed that the optimal swaging length was about 1${\~}$2 mm from the hose end.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.1
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• pp.57-65
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• 1999

This paper deals with stand-alone photovoltaic system(SPVS) with charge and discharge controller. Main power source of SPVS are generally solar cell and battery. Therefore SPVS can be classified into variable types in accordance with connection type between battery and solar cell. Mainly used one of them is direct connection type which has advantages such as simple structure and simple controller. However most big drawback of this system is energy loss by voltage disharmony between solar cell and battery. Therefore SPVS with charge and discharge controller which can operate solar cell at maximum power point is suggested and designed with instantaneous controller. And system operating characteristics are verifieded by experiment with a laboratory prototype in this paper.

• Journal of Chest Surgery
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• v.20 no.4
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• pp.695-705
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• 1987

This report provides follow - up data on 37 patients, aged 7 days to 25 years [median: 6.5 months], who underwent repair of total anomalous pulmonary venous connection at Seoul national University Hospital between May, 1978 and June, 1987. The patients were 22 males and 17 females and the sex ratio was 1.6 to 1, showing a male predominance. Sixteen patients had supracardiac, 13 cardiac, 3 infracardiac and 5 had a mixed type. The duration of follow up was from 1 month to 60 months [median: 14 months] There were eight early and one late deaths, and the overall mortality was 24%. The deaths during 1 year of life were eight [89%] and only one death [11%] occurred above 1 year of age. The mortality of cardiac type was unusually high, accounting for 56 percent of the total death, which was probably due to the preoperative poor clinical condition such as pulmonary edema and congestive heart failure. The major cause of death was the perioperative myocardial failure, and the survival was closely related to the preoperative clinical status, age and moderately elevated pulmonary arterial pressure, the sign of the elevated pulmonary vascular resistance and pulmonary venous obstruction. Early diagnosis and early application of surgical intervention is essential to the improved postoperative survival

• Smart Structures and Systems
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• v.4 no.5
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• pp.685-696
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• 2008

This paper deals with the numerical model of a bracing-friction damper system and its deployment using the optimal slip load distribution for the seismic retrofitting of a damaged building. The Slotted Bolted Connection (SBC) type friction damper system was tested to investigate its energy dissipation characteristic. Test results coincided with the numerical ones using the conventional model of a bracing-friction damper system. The placement of this device was numerically explored to apply it to the assumed damaged-building and to evaluate its efficiency. It was found by distributing the slip load that minimizes the given performance indicies based on structural response. Numerical results for the damaged building retrofitted with this slip load distribution showed that the seismic design of the bracing-friction damper system under consideration is effective for the structural response reduction.

• Steel and Composite Structures
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• v.25 no.4
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• pp.443-456
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• 2017

Many authors have established the usefulness of concrete filled steel tubular (CFST) sections as compression members while few have proved their utility as flexural members. To explore their prospective as part of CFST frame structures, two types of connections using extended end plate and seat angle are proposed for exterior joints of CFST beams and CFST columns. To investigate the performance and failure modes of the proposed bolted connections subjected to static loads, an experimental program has been executed involving ten specimens of exterior beam-to-column joints subjected to monotonically increasing load applied at the tip of beam, the performance is appraised in terms of load deformation behaviour of joints. The test parameters varied are the beam section type, type and diameter of bolts. To validate the experimental behaviour of the proposed connections in CFST beam-column joints, finite element analysis for the applied load has been performed using software ATENA-3D and the results of the proposed models are compared with experimental results. The experimental results obtained agree that the proposed CFST beam-column connections perform in a semi-rigid and partial strength mode as per specification of EC3.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.74.1-74.1
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• 2011

To probe the connection between starburst and AGN activity, we investigate the relation between the 3.3 micron~PAH emission and AGN properties based on the new AKARI observations and the data collected from the literature. Using a sample of low-z Type I AGN, we measure the global 3.3 micron PAH luminosity from the AKARI slit-less spectroscopy. The 3.3 ${\backslash}$micron~PAH emissions are detected for 7 out of 26 target galaxies, but we find no strong correlation between the 3.3 ${\backslash}$micron~PAH emission and AGN luminosity, suggesting that global star formation may not be tightlyrelated with AGN activity. In contrast the to global star formation, the nuclear 3.3 micron~PAH emission luminosity, which are measured from ground-based long slit spectroscopy with a narrow slit, correlates with AGN luminosity. These results imply that starburst and AGN activity are directly connected at the nuclear region.