• 국제초고층학회논문집
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• 제8권1호
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• pp.49-56
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• 2019

Against the background of the rapid development of the Shanghai Metro network, this paper attempts to establish an analytical approach to evaluate the impact of multiple transport network accessibilities on commercial space use in metro station areas. Ten well-developed metro station areas in central Shanghai are selected as samples. Commercial space floor area and visitors in these areas are collected. Using ArcGIS and Spatial Design Network Analysis, the Shanghai Metro network and road network are modeled to compute diversified transport accessibilities. Evidence from land use and commercial space floor area within a 0-to-500-meter buffer zone of stations is consistent with location and land-use theory: commercial land use is concentrated closer to stations. Correlation analysis suggests that hourly visitors to the shopping mall are mainly influenced by metro network accessibility, while retail stores and restaurants are affected by both metro and pedestrian accessibility.

• Nuclear Engineering and Technology
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• 제50권3호
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• pp.453-461
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• 2018

Shaft stations of underground uranium mines in China are not only utilized as waiting space for loaded mine-cars queuing to be hoisted but also as the principal channel for fresh air taken to working places. Therefore, assessment of how mine-car queuing processes affect shaft station radon concentration was carried out. Queuing network of mine-cars has been analyzed in an underground uranium mine, located in Quzhou, Zhejiang province of Eastern China. On the basis of mathematical analysis of the queue network, a MATLAB-based quasi-random number generating program utilizing Monte-Carlo methods was worked out. Extensive simulations were then implemented via MATALB operating on a DELL PC. Thereafter, theoretical calculations and field measurements of shaft station radon concentrations for several working conditions were performed. The queuing performance measures of interest, like average queuing length and waiting time, were found to be significantly affected by the utilization rate (positively correlated). However, even with respect to the "worst case", the shaft station radon concentration was always lower than $200Bq/m^3$. The model predictions were compared with the measuring results, and a satisfactory agreement was noted. Under current working conditions, queuing-induced variations of shaft station radon concentration of the study mine are not remarkable.

• Journal of Positioning, Navigation, and Timing
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• 제4권4호
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• pp.205-211
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• 2015

The Global Navigation Satellite System (GNSS) is undergoing dramatic changes. Nowadays, much more satellites are transmitting navigation data at more frequencies. A multi-GNSS analysis is performed to improve the positioning accuracy by processing combined observations from different GNSS. The multi-GNSS technique can improve significantly the positioning accuracy. In this paper, we present a combined Global Positioning System (GPS), the GLObal NAvigation Satellite System (GLONASS), the China Satellite Navigation System (BeiDou), and the Quasi-Zenith Satellite System (QZSS) standard point positioning (SPP) method to exploit all currently available GNSS observations at Mokpo (MKPO) station in South Korea. We also investigate the multi-GNSS data recorded at MKPO reference station. The positioning accuracy is compared with several combinations of the satellite systems. Because of the different frequencies and signal structure of the different GNSS, intersystem biases (ISB) parameters for code observations have to be estimated together with receiver clocks in multi-GNSS SPP. We also present GPS/GLONASS and GPS/BeiDou ISB values estimated by the daily average.

• Journal of Astronomy and Space Sciences
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• 제24권4호
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• pp.389-396
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• 2007

The Global Navigation Satellite System (GNSS) becomes more important and is applied to various systems. Recently, the Galileo navigation system is being developed in Europe. Also, other countries like China, Japan and India are developing the global/regional navigation satellite system. As various global/regional navigation satellite systems are used, the navigation ground system gets more important for using the navigation system reasonably and efficiently. According to this trend, the technology of GNSS Ground Station (GGS) is developing in many fields. The one of purposes for this study is to develop the high precision receiver for GNSS sensor station and to provide ground infrastructure for better performance services on navigation system. In this study, we consider the configuration of GNSS Ground Station and analyze function of Monitoring and Control subsystem which is a part of GNSS Ground Station. We propose Monitoring and Control subsystem which contains the navigation software for GNSS Ground System to monitor and control equipments in GNSS Ground Station, to spread the applied field of navigation system, and to provide improved navigation information to user.

• Advances in aircraft and spacecraft science
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• 제9권4호
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• pp.279-300
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• 2022

This paper analyzes the possibilities of a new method to using TLE data for detecting satellite maneuvers. The method has a number of advantages over other methods that are designed to detect maneuvers. It allows not only to detect maneuvers, but also to get a more complete picture of the maneuver. In particular, the method makes it possible to estimate the moments of the beginning and end of the maneuver, calculate the changes in the orbital elements, evaluate the tangential and binormal components of the impulse, and finally, calculate the impulse of the satellite obtained as a result of the maneuver. To demonstrate in detail the capabilities of the algorithm, the proposed method was applied to one of LEO satellites - TIANHUI-1 satellite. After the efficiency of the method was proved, this method was applied to the China Space Station - TIANHE-1 (CSS), Starlink-1095 and Starlink-2305 satellites. The maneuvers of the CSS and Starlink-1095 satellite during their close encounter on 1 July, 2021, and the CSS and Starlink-2305 satellite during their close encounter on 21 October, 2021 are analyzed in detail. The minimum distances between the CSS and Starlink satellites at the moments of their maximum approaches are estimated. An estimate of the computation time of this algorithm is given, and the possibility of its use for monitoring maneuvers or other anomalous orbital changes of a large number of satellites in near real-time is shown. It is assumed that on the basis of this method, a service for monitoring satellite maneuvers can be created.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제24권2호
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• pp.55-64
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• 2018

Purpose: The ward division is a representative part of the hospital, where a variety of user activities are performed. Users can be broadly categorized as patients and carers, visitors, and medical staff (doctors and nurses). The relationship between these two is a major issue with ward planning as the patient's place of life centers around the hospital room and the task of the clinical workforce centers around the nursing station (NS). Against this backdrop, the study divides the ward units of the General Hospital of China into patient areas, medical team areas, supply areas, and public domain, with the focus on the ward areas affecting most significantly in the hospital patients. Methods: The theoretical advance studies of the standard ward unit are identified by the associated guidelines, articles, and documentation. Results: This study is a summary analysis of relevant regulations, reference literature, and drawing data from the target hospital. Further work is expected to be undertaken, including further surveys and observational surveys, to produce more detailed results. Implications: It is expected that the research in this paper will provide an effective reference for the future research of China General Hospital Ward department, so as to promote and improve the work system of China General Hospital Ward department.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.2
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• pp.203-208
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• 2006

The main research conducted previously on GPS ionosphere in China is first introduced. Besides, the current investigations include as follows: (1) GPS-based spatial environmental, especially the ionosphere, monitoring, modeling and analysis, including ground/space-based GPS ionosphere electron density (IED) through occultation/tomography technologies with GPS data from global/regional network, development of a GNSS-based platform for imaging ionosphere and atmosphere (GPFIIA), and preliminary test results through performing the first 3D imaging for the IED over China, (2) The atmospheric and ionospheric modeling for GPS-based surveying, navigation and orbit determination, involving high precisely ionospheric TEC modeling for phase-based long/median range network RTK system for achieving CM-level real time positioning, next generation GNSS broadcast ionospheric time-delay algorithm required for higher correction accuracy, and orbit determination for Low-Earth-orbiter satellites using single frequency GPS receivers, and (3) Research products in applications for national significant projects: GPS-based ionospheric effects modeling for precise positioning and orbit determination applied to China's manned space-engineering, including spatial robot navigation and control and international space station intersection and docking required for related national significant projects.

• 한국위성정보통신학회논문지
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• 제12권3호
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• pp.54-62
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• 2017

중국은 서태평양, 남중국해, 인도양에서 미국 및 역내 국가들의 해양세력 움직임에 신속히 대처하기 위하여 1960년대부터 기존의 지상 및 항공 감시체계를 벗어나 우주기반 감시능력을 확보하기 위해 군사위성분야에 많은 투자를 해왔다. 수차례의 실험위성 발사 및 운용시험을 통하여 핵심기술을 확보한 후에 2006년 이후 EO, SAR, ELINT분야의 군사 첩보위성인 Yaogan위성을 현재까지 약 40여 차례 이상 발사하여 운용하고 있다. 특히 전구적으로 운용 가능한 수십여 기의 ELINT 신호수집 위성을 중심으로 우주기반 위성네트워크를 구축하여 수집된 자료를 지상으로 실시간 전송함과 동시에 지상기반 C4ISR 네트워크와 연동된 대함탄도미사일인 ASBM에 해양 공격목표 자료를 제공함으로써 중국의 주변 해양세력에 대한 감시 및 미사일 공격능력을 한층 더 강화시켰다. 향후 전자신호 위성수집분야에 더욱더 기술적인 연구를 통해서 정확한 위치 탐색과 분석능력을 확대시킬 것으로 판단된다.

• 천문학회보
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• 제42권2호
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• pp.59.3-59.3
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• 2017

We will present the activities of East Asian VLBI Network, EAVN, which consists of around 20 radio telescopes in Japan, Korea, and China with 6,500 km extend. It is a most sensitive and highest VLBI array in the world. We have conducted science verification observations at mainly 8 and 22 GHz. And Japanese VLBI array, VERA, and Korean VLBI array, KVN have combined as KaVA, Korean and VERA Array, and started science observations with open use at 22 and 43 GHz. We will presents some commissioning and science results based on it. Moreover Taiwan is constructing the Greenland telescope to be a millimeter and submillimeter VLBI station, which will be a very powerful station in Global millimeter and submillimeter VLBI array. These activities will be introduced as well.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.612-615
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• 2005

Korea Aerospace Research Institute(KARl) has been receiving Terra and Aqua MODIS data at ground station of Daejeon since July 2002. MODIS data can cover whole East Asia including the Korean Peninsula, Japan and The East China each almost scene and is monitoring ocean, atmosphere and land. By this time, over two thousand scenes have been archived including Terra and Aqua in the storage system and they occupied about over 10TB of disk space. In this study, Web-Downloading system of MODIS data developed on WWW is including following main functions: spectral subset (250m, 500m, 1000m chnnels) Level 1B data of HDF format, result display, ftp download and statistic viewer etc. Users using this system can directly download MODIS data on WWW with a few input parameters. This system is available via the Internet URL after October 2005 on the following, 'http://webmodis.kari.re.kr/'