• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.3
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• pp.9-14
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• 2009

Recently, a rate-2, $2{\times}2$ space-time code with simple ML decoding has been designed. Though the simple ML decoding algorithm does reduce the ML decoding complexity, there is still need for improvement. In this paper, we propose an efficient decoding algorithm for the rate-2, $2{\times}2$ space-time code using interference cancellation techniques with performance virtually identical to that of ML decoding. Also, the decoding complexity of the proposed algorithm is significantly reduced compared to the conventional simple ML decoding, especially for large modulation orders.

• Journal of Astronomy and Space Sciences
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• v.32 no.3
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• pp.209-219
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• 2015

The Accurate Ranging System for Geodetic Observation - Mobile (ARGO-M) was successfully developed as the first Korean mobile Satellite Laser Ranging (SLR) system in 2012, and has joined in the International Laser Ranging Service (ILRS) tracking network, DAEdeoK (DAEK) station. The DAEK SLR station was approved as a validated station in April 2014, through the ILRS station "data validation" process. The ARGO-M system is designed to enable 2 kHz laser ranging with millimeter-level precision for geodetic, remote sensing, navigation, and experimental satellites equipped with Laser Retro-reflector Arrays (LRAs). In this paper, we present the design and development of a next generation high-repetition-rate SLR system for ARGO-M. The laser ranging rate up to 10 kHz is becoming an important issue in the SLR community to improve ranging precision. To implement high-repetition-rate SLR system, the High-repetition-rate SLR operation system (HSLR-10) was designed and developed using ARGO-M Range Gate Generator (A-RGG), so as to enable laser ranging from 50 Hz to 10 kHz. HSLR-10 includes both hardware controlling software and data post-processing software. This paper shows the design and development of key technologies of high-repetition-rate SLR system. The developed system was tested successfully at DAEK station and then moved to Sejong station, a new Korean SLR station, on July 1, 2015. HSLR-10 will begin normal operations at Sejong station in the near future.

• Journal of Photoscience
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• v.9 no.3
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• pp.37-40
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• 2002

Astronauts are constantly exposed to space radiation at a low-dose rate during long-tenn stays in space. Therefore, it is important to determine correctly the biological effects of space radiation on human health. Space radiations contain various kinds of different energy particles, especially high linear energy transfer (LET) particles. Therefore, we have to study the relative biological effectiveness (RBE) of space radiation under microgravity environment which may change RBE from a stress for cells. Furthermore, the research about space radiation might give us useful information about birth and evolution of life on the earth. We also can realize the importance of preventing the ozone layer from depletion by use of exposure equipment to sunlight at International Space Station (ISS).

• Journal of the Korean Solar Energy Society
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• v.23 no.3
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• pp.73-80
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• 2003

The purpose of this study was to analyze daylighting performance in a semi-infinite size office space for lighting energy conservation. DOE2.1E was used for simulations for the model space of $12\times12\times2.6m$. Nomographs were developed which could simulate work plane illuminance, glare index, energy consumption rate and energy reduction rate for daylighting design. Major results of simulations are as follows ; 1) When blinds facing south were installed, 43% of workplane illuminance diminished, but the flare index didn't exceed the recommended max-glare value. 2) In a semi-infinite office space facing south. energy consumption rate in the case space of 500 lux workplane illuminance is larger then case space of 300 lux workplane illuminance. Therefore, energy reduction rate is increased when the semi-infinite office faces south and naintains 300 lux workplane illuminance level.

• Current Industrial and Technological Trends in Aerospace
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• v.9 no.1
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• pp.3-14
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• 2011

The current space activities are soaring ever since the first human flight to outer space 50 years ago and the first satellite launch 54 years ago. 74 space launch vehicles were launched in 2010, up from average 66 yearly in 2000s, and 900 operational satellites are currently in orbit around Earth. Space has become a worthwhile investment for governments as space assets become vital to national social, economic, and technological development as well as contributing their national defense and security program. The world governments' investments on space programs have reached a historical peak of $71.5 billion in 2010. However, the growth of government funding for space has slowed down posting only a 2% growth rate since 2009 while 9 % compound annual growth rate experienced by world's space expenditures between 2004 and 2009. Korea invested $158 million in 2011, experienced strong decrease with a 16% compound annual growth rate since 2008. In this paper the current statuses of world governments' funding for space program and space market were presented and the current issues on the Korean space budget policy were reviewed.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.10
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• pp.297-303
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• 2021

The performance of the retail industry in a country, which simultaneously reflects the demand for retail space, is significantly influenced by the macroeconomic environment of said country. However, in the case of Malaysia, studies regarding this issue are limited. Therefore, this paper aims to identify the macroeconomic determinants of the demand for retail space in shopping centers in Malaysia through the study of six variables: per capita income, private expenditure, inflation rate, interest rate, total population, and the number of tourists arrival. The nexus between these variables and the demand for retail space in shopping centers were examined by cointegration and causality tests, and regression analysis using quarterly data for the period 1993Q1 to 2016Q4. The results from bivariate cointegration tests indicate that inflation rate, interest rates, population size, and the number of tourists arrival have significant long-run relationships with the demand for retail space of Malaysian shopping centers. Meanwhile, the Granger causality tests show that only population size can cause the demand for shopping centers' retail space. Finally, the results from the regression analysis revealed that income per capita, private expenditure, interest rates, and population are the variables that significantly influence the demand for the retail space of the Malaysian shopping centers.

• Honam Mathematical Journal
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• v.37 no.4
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• pp.487-504
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• 2015

For a smooth plane curve, the curvature can be characterized by the rate of change of the angle between the tangent vector and a fixed vector. In this article we prove that the curvature of a space curve can also be given by the rate of change of the locally defined angle between the tangent vector at a point and the nearby point. By using height functions, we introduce turning angle of a space curve and characterize the curvature by the rate of change of the turning angle. The main advantage of the turning angle is that it can be used to characterize the curvature of discrete curves. For this purpose, we introduce a discrete turning angle and a discrete curvature called visual curvature for space curves. We can show that the visual curvature is an approximation of curvature for smooth curves.

• Journal of architectural history
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• v.8 no.2 s.19
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• pp.59-72
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• 1999

The purpose of this study is to find the spatial factors, strucure of living and activity in traditional Korean house through the Phiysiological view, Spatial factors of the house are concerned to the interior environment and sanitary condition, The elements of respiratory, nerve, temperature sence. vision, hearing, smelling have good condition and touch, pressure sence, pain, metabolism are poor in the house, Ventilation, Lighting, pleasant condition of interior environment are concerned to the elements that mentioned above and have most important meaning in the relation rate of space as 1st factor. And 2nd factor is for metabolism, housework and rest, 3rd factor ie for temperature sence, privacy and reproduction. The relation rate of factors concering interior environment are high in the upper class house. Anbang has important meaning in the relation of living structure and relation sequence of space is anbang, Konnonbang, kitchen, toilet, water place, auxiliary buildings. The relation rate of activity is high in interior space in winter and exterior space in summer.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.335-338
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• 2002

For high data rate transmission over wireless fading channels, space-time trellis ceding techniques can be employed to increase the Information capacity of the communication system dramatically. In this paper, we consider the concatenated space time LDPC (Low Density Parity Check) codes. Extra ceding gains In addition to the diversity advantage is shown to be achieved for certain space-time trellis codes transmitted over quasi-static lading channels.

• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.3
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• pp.66-77
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• 1998

The purpose of this study is on identifying real condition of naturalized plants in urban green space. For this, Chollabak-do region was selected for case study. The occurring frequency and distribution status was investigated by field survey. The area of green open space, level of management and passed years after construction etc, were analized to identify the influence on occurrence of naturalized plants. The result is as follows: 1. In 18 sites, 145 taxa as weed species including naturalized plants were occurred. Average No. of occurring taxa is 22.7. Two families of plants, Graminae and compositae charged the most part. Also the rate of naturalized plant among them is 29.7%. 2. Naturalized species showing high occurring rate are 14 taxa of compositae, 5 taxa of Gramineae, Leguminosae and 4 taxa of cruciferae. These plants of previous four somatic polymorphism among all the naturalized plants. 3. The taxa number of naturalized plants were reducedby intensive management. But the rate of naturalized plants in extensively managed area was relatively lower than intensively managed one. Naturalizd plants were widely distributed in most of urban green space with being cognitioned as whole weed. 4. In origin of naturalized plants, the taxa from north America were 16 and the taxa from Europe were 16. Therefore the rate originated from north America and Europe charged high part as 68.2%. The rate of Annual, Biennial and Perennial were each 78.7%, 21.3%. The alternative of management for control aganist disturbance by Annual & Biennial required. 5. Multi-relations analysis shows 0.81 which is the relatively high interralation between the number of emerged axa and that of naturalized ones. 6. The number of naturalized species has no relation to the lapse of years after construction of open-space. Especially it was identified that weed control in the beginning of construction is very important. On the other hand the relation between Ys and Xp was Ys=1.784Xp+4.646.