• Journal of Astronomy and Space Sciences
• /
• 제27권2호
• /
• pp.123-128
• /
• 2010

This paper analyzes that the global positioning system (GPS) receiver differential code bias (DCB) has effect on the estimation the ionosphere total electron content (TEC). The data from nine permanent GPS sites of the Korea Astronomy and Space Science Institute (KASI) were used for the estimation of the receiver DCB before (Trimble 4000 SSi) and after (Trimble NetRS) the receiver replacement, using the singular value decomposition method. The results showed that the estimated mean value of the receiver DCB varied from 0.11 ns (nanosecond) to 7.54 ns before the receiver replacement, but the receiver DCBs shoed large values than 20 ns except some stations after the replacement. The receiver DCB showed a relatively large difference by types of the receivers, and, as a result, it had a great effect on the estimation the ionosphere TEC using GPS.

• 대한수학회논문집
• /
• 제17권1호
• /
• pp.71-80
• /
• 2002

We give a formulation of the large deviation property for rescalings of random measures on the d-dimensional Euclidean space R$^{d}$ . The approach is global in the sense that the objects are Radon measures on R$^{d}$ and the dual objects are the continuous functions with compact support. This is applied to the cluster random measures with Poisson centers, a large class of random measures that includes the Poisson processes.

• 한국실내디자인학회논문집
• /
• 제22권5호
• /
• pp.284-292
• /
• 2013

The study performed analysis focusing on specialized convention and exhibition facilities among convention and exhibition facilities in Korea. The procedures and results were as follows: First, by theoretical consideration, meaning and contents of convention and exhibition programs done in convention and exhibition facilities were considered and after that, general characteristics of the programs which were the main of space utilization was derived. Second, considering scale and location, 6 facilities were re-selected for in-depth research from 12 facilities investigated preliminarily. Selected facilities were categorized by scale and through the analysis of programs done in this facilities for the last 1 year, overview and characteristics of utilization for exhibition space, conference space, and multi-purpose space, etc were analyzed. Third, through the case study on the programs, individual characteristics of space utilization by convention and exhibition program were analyzed. From the result of the study, considering the whole, the space utilization of programs was done as conference space rather than exhibition space and the ratio of use as conference space to use as exhibition space was 1.8 in the large facilities, 6.7 and 7.6 in the middle facilities and the small facilities, respectively. In the middle and small facilities, the ratio of use of one room as conference space was very high. In the large facilities, there was no big difference with the ratio 50:50 of the programs involving exhibition to other programs, but in the middle and small facilities, the ratio of the former to the latter was observed over 2.4 and 3.6. This fact indicated that the function of use as promotion and communication space for companies and industrial entities which were the essential purposes became low.

• 한국공간구조학회논문집
• /
• 제21권1호
• /
• pp.95-104
• /
• 2021

As people's living standards and cultural standards have developed, interest in culture and art has increased, and the demand for large space structures where people can enjoy art, music, and sports has increased. As it accommodates a large number of personnel, it is most important to ensure safety of large spatial structures, and can be used as a space where people can evacuate in case of a disaster. Large spatial structures should be prepared for earthquake loads rather than wind loads. In addition to damage to the structure due to earthquakes, there are cases in which it was not utilized as a space for evacuation due to the fall of objects installed on top of the structure. Therefore, in this study, the dome-shaped large spatial structure is generalized and the displacement response according to the number of installations, position and mass is analyzed using a tuned mass damper(TMD) that is representative vibration control device.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제49권8호
• /
• pp.509-513
• /
• 2000

This paper deals with the parallel operation of space vector PWM for large capacity inverter system. To enlarge the capacity of inverter system and to reduce the current ripples on inverter output side, two or more inverters are operated in parallel. In this paper, a new parallel operation strategy which minimizes the harmonic distortion of the output stage is described. The proposed method is developed on the basis of the space-vector PWM in order to increase the linearly controllable voltage range. With the help of the proposed voltage synthesis method, the total harmonic distortion of the output stage can be greatly reduced in compared with that of conventional method with sinusoidal PWM or that of the single inverter operation case. The experimental results with reduced scale test show the feasibility of the proposed voltage synthesis method.

• 한국멀티미디어학회논문지
• /
• 제24권3호
• /
• pp.468-480
• /
• 2021

Realistic real-time rain streaks rendering has been treated as a very difficult problem because of various natural phenomena. Also, in creating and managing a large number of particles, a large amount of computer resources had to be used. Therefore, in this paper, we propose a more efficient real-time rain streaks rendering algorithm by generating view-dependent rain particles and expressing a large amount of rain even with a small number. By creating a 'rain space' dependent on the field of view of the camera moving in real time, particles are rendered only in that space. Accordingly, even if a small number of particles are rendered, since the rendering is performed in a limited space, an effect of rendering a very large amount of particles can be obtained. This enables very efficient real-time rendering of rain streaks.

• 시스템엔지니어링학술지
• /
• 제12권2호
• /
• pp.19-27
• /
• 2016

Many countries concentrated on the space developments to enhance the national security and the people's quality of life. A space launch vehicle for accessing the space is a typical large complex system that is composed of the high-technology like high-performance, high-reliability, superhigh-pressure, etc. The project developing large complex system like space launcher is mostly conducted in the uncertain environment. To achieve a goal of the project, its success probability should be enhanced consistently by reducing its uncertainty during the life cycle: it's possible to reduce the project's uncertainty by performing the risk management (RM) that is a method for identifying and tracing potential risk factors in order to eliminate the risks of the project. In this paper, we introduce the risk management (RM) process applied for a Space Launch Vehicle R&D Project.

• 천문학논총
• /
• 제27권4호
• /
• pp.375-380
• /
• 2012

The Herschel Space Observatory is the European Space Agency's state of the art infrared space telescope launched into space on 14 May 2009, covering the wavelength range from 70-700 microns with 3 instruments SPIRE, PACS and HIFI. Large area surveys are being carried out by Herschel in the AKARI legacy fields at the North and South Ecliptic Poles and the AKARI All-Sky Survey provides additional synergy with the largest survey with Herschel, H-ATLAS, covering more than 500 square degrees. This paper reports on some of the early results of these synergies between Herschel and AKARI including the first comparison of the AKARI All-Sky Survey number counts with the deeper Herschel surveys.

• 천문학회보
• /
• 제32권1호
• /
• pp.70.1-70.1
• /
• 2007

• 한국항해항만학회지
• /
• 제26권4호
• /
• pp.441-447
• /
• 2002

전세계적인 인구증가와 산업화로 인하여 육지면적의 부족, 육상자원의 고갈 등의 문제로 해양의 이용 및 개발의 관심이 늘어나고 있으며, 환경친화적인 해양공간을 확보하기 위하여 초대형 부유식 해상구조물에 대한 기술개발이 요구되고 있다. 본 논문에서는 초대형 부유식 구조물의 상부구조물에 대한 시간이력해석법에 대하여 소개하고 파랑하중에 의한 부체변형을 이용한 시간변위이력 산정 방법을 제안한다. 또한 주기 및 진폭의 변화에 따른 상부구조물의 동적 시간이력응답 결과를 분석하고 초대형 부유식 상부구조물 시설계안의 동적구조안전성을 평가한다.