• Title/Summary/Keyword: space technology

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Trends of the CR Technology in TV White Spaces (TV White Spaces에서의 CR 기술 동향)

  • Ko, G.Z.;Park, C.H;Song, M.S.;Um, J.S.;You, S.J.;Lim, S.M.;Jung, H.Y.;Hwang, S.H.
    • Electronics and Telecommunications Trends
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    • v.24 no.3
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    • pp.91-102
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    • 2009
  • FCC(Federal Communications Commission 미국 연방통신위원회)는 2008년 11월 스펙트럼 사용 효율을 높이고 새로운 서비스 도입을 용이하게 하기 위해 TV White Spaces를 대상으로 주파수 공유 기술인 Cognitive Radio 기술을 적용하기로 하고 관련 규정을 개정하였다. FCC는 TV White Spaces에서 고정 서비스와 개인/휴대서비스기기 사용을 허용하기로 방침을 정하고 2009년 5월 12일 DTV 전환 완료 이후 관련 기기 사용을 허용하기로 하였다. 본 논문에서는 FCC의 법규 개정 현황과 함께 이를 기술적으로 뒷받침하기 위한 IEEE 802.22, TV White Spaces ECSG, ECMA에서의 표준화 동향을 설명하고, 핵심 기술로서 스펙트럼 센싱 기술, 무선자원관리 기술, PHY/MAC 관련 기술 개발 동향에 대해 요약 기술하였다.

The New Developments of China's Space Policy

  • Li, Shouping
    • The Korean Journal of Air & Space Law and Policy
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    • v.27 no.1
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    • pp.157-169
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    • 2012
  • China's Space Activities in 2011 (thereafter 2011 White Paper) was published by Information Office of State Council of the Peoples Republic of China on December 29, 2011, and it was the third space white paper after 2000's space white paper and 2006's space white paper. The 2011 White Paper summarizes splendid achievements China had received in space area since 2006, and systematically introduces the principles of China's space activities; at the same time, it also presents the world the policies, measures and key areas of China's space activities in the following five years. This 2011 White Paper is the most detailed, concrete, and integrated elaboration of China's space policy, and it will be the guideline for China to explore outer space with peaceful purpose in the next five years. Compared with 2000's and 2006's White Papers, the 2011 White Paper indicated that Chinese government adjusted space policies under the new circumstance. The 2011 white paper stressed China's position on use of outer space for peaceful purpose and highlighted the new idea of scientific and innovative development in space industry in the next five years.

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Modeling of Space Radiation Exposure Estimation Program for Pilots, Crew and Passengers on Commercial Flights

  • Hwang, Junga;Dokgo, Kyunghwan;Choi, Enjin;Park, Jong-Sun;Kim, Kyung-Chan;Kim, Hang-Pyo
    • Journal of Astronomy and Space Sciences
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    • v.31 no.1
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    • pp.25-31
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    • 2014
  • There has been a rapid increase of the concern on the space radiation effect on pilots, crew and passengers at the commercial aircraft altitude (~ 10 km) recently. It is because domestic airline companies, Korean Air and Asiana Airlines have just begun operating the polar routes over the North Pole since 2006 and 2009 respectively. CARI-6 and CARI-6M are commonly used space radiation estimation programs which are provided officially by the U.S. federal aviation administration (FAA). In this paper, the route doses and the annual radiation doses for Korean pilots and cabin crew were estimated by using CARI-6M based on 2012 flight records. Also the modeling concept was developed for our own space radiation estimation program which is composed of GEANT4 and NRLMSIS00 models. The GEANT4 model is used to trace the incident particle transports in the atmosphere and the NRLMSIS00 model is used to get the background atmospheric densities of various neutral atoms at the aircraft altitude. Also presented are the results of simple integration tests of those models and the plan to include the space weather variations through the solar proton event (SPE) prediction model such as UMASEP and the galactic cosmic ray (GCR) prediction model such as Badhwar-O'Neill 2010.

Variation of Floating Potential in the Topside Ionosphere Observed by STSAT-1

  • Lee, Junhyun;Lee, Ensang;Lee, Jaejin;Kim, Khan-Hyuk;Seon, Jongho;Lee, Dong-Hun;Jin, Ho;Kim, Eung-Hyun;Jeon, Hyun-Jin;Lim, Seong-Bin;Kim, Taeyoun;Jang, Jaewoong;Jang, Kyung-Duk;Ryu, Kwangsun
    • Journal of Astronomy and Space Sciences
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    • v.31 no.4
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    • pp.311-315
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    • 2014
  • In this study, we investigated the effect of space plasmas on the floating potential variation of a low-altitude, polar-orbiting satellite using the Langmuir Probe (LP) measurement onboard the STSAT-1 spacecraft. We focused on small potential drops, for which the estimation of plasma density and temperature from LP is available. The floating potential varied according to the variations of plasma density and temperature, similar to the previously reported observations. Most of the potential drops occurred around the nightside auroral region. However, unlike the previous studies where large potential drops were observed with the precipitation of auroral electrons, the potential drops occurred before or after the precipitation of auroral electrons. Statistical analysis shows that the potential drops have good correlation with the temperature increase of cold electrons, which suggests the small potential drops be mainly controlled by the cold ionospheric plasmas.

A Study on the Hierarchical Organization of the Exterior Space in the Multi-Family Housing Complexes in the Urban Area - By Analysing the Exterior Space in Korean Traditional Architecture - (도시 집합주거의 외부공간의 위계적인 구성방식에 관한 연구 - 한국 전통건축의 공간구성기법을 응용하여 -)

  • Park, Chang-Geun
    • Journal of Industrial Technology
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    • v.26 no.A
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    • pp.29-38
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    • 2006
  • Efficiency and universality which was the spirit of the modern age, had also an enfluence on our living environment. Various types of individual housing unit were developed and mass-produced. However, the exterior space in our city is a place for our social life and intermediate place to connect the private life of each individual to our society. For the people to adapt themselves well to their environment, it should be well organized which means it is clearly divided and integrated in a hierarchical order. To realize these conditions, adequate boundaries to divide each territory and entrances to connect each territory are two essential elements. One of the possible methods to realize these conditions can be found in korean traditional architecture where the exterior space has the same figural quality like buildings and is the center of the whole composition. Buildings, walls and colonnades are the elements to define space. Gates, pavilions, gabs between buildings and posts are the elements to symbolize the entrance connecting each space. Each exterior space is integrated to a whole composition. One is the gradual differentiation along the axis which is unique in korean traditional architecture. The other is the rectangular connection which is also found in the other area in the world. The results of this thesis are as follows. The exterior space in the housing area should have the figural quality. The elements to make boundaries defining exterior space are classified into horizontal elements such as low buildings and walls, and vertical elements such as tower-shape buildings which define space in a different way. The position of openings in a housing block affects the characteristic and openness of a exterior space. Various types of gates are used to decide the relationship between spaces.

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A Review of PCA Rules for Arbitration of Disputes Relating to Outer Space Activities (우주활동분쟁에 관한 PCA 중재규칙에 관한 소고)

  • Young-Ju Kim
    • Journal of Arbitration Studies
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    • v.33 no.2
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    • pp.109-137
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    • 2023
  • This paper reviews legal framework, characteristics and main contents of the 'Optional Rules for the Arbitration of Disputes Relating to Outer Space Activity' enacted by the Permanent Court of Arbitration (PCA) in 2011. Space activities, which began in the 1950s, are undergoing significant changes according to the international characteristics and development of science and technology. New Space and the space business will be the key factors driving these changes. However, the diversity of disputes caused by New Space space activities and the characteristics of each type of dispute must be considered together. This is because the space business can be maintained and developed by securing the effectiveness of dispute resolution. This paper identifies that the PCA Space Dispute Arbitration Rules have important legislative and policy significance in this respect. Specifically, in this paper, the international space law system, the draft convention of the International Law Association, and the PCA arbitration rules were introduced in an overview of the international dispute settlement system related to space activities. Afterwards, it examines that the systematic structure and some major contents of the PCA Space Dispute Arbitration Rules in detail. Based on this, the paper suggests some points of application of the PCA Arbitration Rules and the legislative policy implications.

A STATISTICAL STUDY OF MAGNETIC STORM RECOVERY PHASE: PRELIMINARY RESULTS

  • Lee, D.Y.;Hwang, J.A.;Min, K.W.;Lee, E.S.;Cho, K.S.;Kim, S.G.;Bae, S.H.
    • Journal of Astronomy and Space Sciences
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    • v.18 no.1
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    • pp.27-32
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    • 2001
  • A statistical study has been performed of the magnetic storm recovery phase using the Dst index for 102 storm events in the interval January 1996 to December 1998. In 43 cases (or 42%) out of our 102 events, the recovery phase exhibits fast recovery (kaking about 8 hours or less) at its initial stage or for the entire recovery period. Since this fast recovery can be explained by the fast charge exchange less of $O^{+}$ ions which mostly com from the ionosphere, and since a fraction of $H^{+}$ ions is of ionospheric origin as well, our statistical result supports the view that the source of ring current ions in many magnetic storms can be terrestrial.

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The correct depth representation in displayed space at stereoscopy

  • Lee, Kwnag-Hoon;Kim, Dong-Wook;Kim, Soo-Ho;Hur, Nam-Ho;Kim, Sung-Kyu
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.707-709
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    • 2008
  • We proposed the method to present corrected depth cue to an observer by stereoscopic display. It was performed in sequence that designing the displayed space having a constant interval of depth and then defining the object space which had considered to an environment of display and based on computer graphics. Consequently, we had performed a different process of reported existing methods distinctively and taken the result which correctly designed depth cue having linearity whatever various sizes of display would be used.

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