• Journal of Life Science
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• v.28 no.1
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• pp.105-109
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• 2018

Biodiversity (or biological diversity) is defined as the variability of living organisms, the "diversity of life on Earth," and the complex relationships that make up ecosystems. This study aimed to investigate the spatial and temporal patterns in animal species composition and diversity at the Deukjin River, located in Hapcheon Province, Korea. The fauna community at the Deukjin River during 2016 season was identified with a total of 55 taxa, representing the following six classes: Mammalia (mammals), Actinopterygii (bony fish), Chondrichthyes (cartilaginous fish), Aves (birds), Amphibia (amphibians), Reptilia (reptiles), and invertebrates. The Berger - Parker index (BPI) for mammals varied from 0.233 (Station A) to 0.333 (Station D). The Shannon - Weaver index (H') and two diversity indexes (N1 and N2) for mammals and birds in the upper region were higher than those in the lower region. The values of ${\beta}$-diversity for animals varied from 0.229 for fish to 0.339 for invertebrates. The richness indices for animal taxa also varied among the stations and seasons. Station A showed considerably high richness in mammals, birds, and reptiles/amphibians. Although the richness indices (R1 and R2) for six animal kingdoms during the seasons were different from each other, the difference was not significant (p<0.05). The evenness indices for five animal kingdoms were different from each other, but again, the difference was not significant (p<0.05).

• Land and Housing Review
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• v.15 no.1
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• pp.77-97
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• 2024

This study aims to examine the distinctions in evaluation index items between overseas and domestic ecological area-related systems, derive analytical indicators, and assess recently completed apartment complexes before and after the implementation of overall ecological area ratios. The objective is to analyse variances in the application of ecological area characteristics, categorizing them into ecological area analysis indicators and presenting their implications. The spatial scope covers completed apartment complexes in both metropolitan and non-metropolitan areas. Thirty-six completed apartment complexes were selected for analysis, and basic ecological area data were compiled. Subsequently, the data was utilized to categorize three analysis indicators-ecological area ratio, ecological area diversity, and ecological area connectivity-by metropolitan and non-metropolitan areas, as well as by type of apartment complex (sale housing versus rental housing) and size (large-scale, medium-scale, and small-scale). Results of the analysis indicate higher ecological area ratios and greater diversity in ecological area spatial types in metropolitan areas compared to non-metropolitan areas, and in pre-sale housing complexes compared to rental housing complexes. Mediumand large-scale apartment complexes exhibit higher ecological area ratios, with ecological area diversity being more pronounced. Ecological area connectivity reveals more numerous and varied connection points and types in metropolitan areas than in non-metropolitan areas. Implications of this study suggest that large-scale development should prioritize securing ecological area ratios and diversity in apartment complexes. Enhancing biodiversity necessitates establishing connections within and beyond the ecological area network of the complex. Future research should focus on linking the ecological area network within the complex.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.11
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• pp.1254-1261
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• 2007

Mc-OFDM(Multi code-Orthogonal Frequency Division Multiplexing) modulation has been developed for high-speed data transmission over wireless channels. However, this system suffers critical problem from relatively high PAPR(Peak to Average Power Ratio). To reduce PAPR, we suggest a new technique, called Mapping using (N+1)PSK and demonstrate the performance of mapped Mc-OFDM system. On the other side, in OFDM system, each sub-carrier experiences different fading, thus some sub-carriers may be completely lost because of deep fade. To solve a above mention problem, we propose cooperative communications that improve the reliability of sub-carriers through spatial diversity.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.5 no.2
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• pp.68-73
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• 2012

This paper is an analysis the performance of CDMA system using array antenna beamforming technique in wireless channels. Adaptive array beamforming antenna technique combine receive signal amplitude with phase in array antenna element, and can be incremental spatial filter function a direction of arrival signal using weight value. Through simulation, in this paper, we were an analysis to compare bit error rate of forward and backward channels using array antenna beamforming technique in order to interference signal decrease of CDMA fading enviroment. The result simulation, we get spatial diversity effect by using array antenna system, and improved the performance to MAI interference decrease.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.7
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• pp.43-51
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• 2013

This paper describes the development of the telemetry link system for the high data rate transmission in high speed rocket application. In consideration of bandwidth efficiency, frequency selective fading and doppler frequency offset, we used DQPSK instead of PCM/FM which has been the primary modulation format in aeronautical telemetry. Also we used the spatial diversity with multiple receiving antennas to mitigate multipath interference which is the dominant channel impairment and the Turbo Product Code for Forward Error Correction to improve bit error rate performance.

• Journal of Communications and Networks
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• v.16 no.3
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• pp.280-292
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• 2014

This article presents a novel cooperative spectrum sharing (CSS) scheme. The primary transmitter transmits a complex Quadrature amplitude modulation (QAM) signal in the first phase, and CSS occurs in the second phase. The secondary transmitter with the largest forwarding channel gain among the nodes that successfully decode the primary signal in the first phase is selected for CSS. This selected node employs a pulse-amplitude modulation (PAM) signal for primary information message (IM) instead of the QAM signal, and it employs a modified PAM signal for the secondary IM. The proposed modified PAM signal depends on the amplitude of the primary PAM signal. This method results in no mutual interference and negligible primary interference constraint and allows a higher degree of exploitation of spatial diversity, thus enabling increase in secondary power to improve primary transmission. The outage performance is enhanced in both the primary and secondary systems. The critical region, in which the primary outage performance is enhanced with the proposed CSS scheme, can be adjusted and widened by varying either the modulation cooperation sharing factor or the number of secondary transmitters.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.15-20
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• 2016

Compared to the MIMO system using the spatial multiplexing methods and the MIMO system using the diversity scheme achieved a high rate, but the lower the diversity gain to improve the data transmission reliability should separate the spatial stream at the MIMO receiver. In this paper, we compared Channel capacity detection methods with the Lattice code, the 3-user interference channel and linear channel interference detection methods ZF (Zero Forcing) and MMSE (Minimum Mean Square Error) detection methods. The channel is a Diagonal channel. In other words, Diagonal channel is confirmed by the inverse matrix satisfies the properties of Jacket are element-wise inverse to $[H]_N[H]_N^{-1}=[I]_N$.

• Journal of the Korean housing association
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• v.21 no.6
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• pp.131-141
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• 2010

This study is aimed to grasp the spatial characteristics exhibited in the modern housing architecture from the aspect of a geometrical manipulation, which transforms basic geometrical shapes and persue the formative diversity, to identify and verify the various characteristics of spatial structure in modern housing architecture. In this regard, this paper analyze and identify the influences of the void spaces that are created by geometrical manipulations on housing architecture, in terms of morphological and environmental aspects. Theoretical approaches define the concept of geometrical manipulation according to the characteristics of residence and examine the spatial features of void spaces. Additionally, case studies result in the classification of void spaces that are created by geometrical manipulation. Furthermore, to understand environment-friendly characteristics of the void space, the researcher elicited the factors that can affect environment friendly housing from previous studies, and analyzed their correlation between those factors and the void spaces that are classified.

• Korean Journal of Environmental Biology
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• v.23 no.2 s.58
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• pp.93-97
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• 2005

Zooplankton dynamics were investigated based on samples collected monthly during the period between November 1998 and October 1999 at 15 stations in Gwangyang and Sachon Bay. Zooplankters were quantitatively collected with horizontal towing through the surface and oblique hauling from the bottom to surface at each station, simultaneously. A total of 88 taxa of zooplankton were distributed and 60 taxa were identified to species. Copepods showed the prosperity in species number of 52 species. Number of taxa occurred in samples hauled obliquely always showed $2\~5$ more species than those captured in the surface except for stations near the Namhae bridge. In waters near Namhae bridge, fast current seemed to mix waters vertically. Seasonally these differences were more distinct in the spring and summer than those in other seasons possibly due to the stratification in warmer seasons. In quantitative aspects, differences between two layers seemed to be obscure. Spatial and temporal variations in species diversity of copepods showed more prosperity in pelagic realm than those in the surface. Our collection carrying out in day time might be one of the important reason to cause these differences in zooplankton dynamics between two layers.

• ETRI Journal
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• v.41 no.2
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• pp.145-159
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• 2019

To reduce the number of radio frequency (RF) chains in multiple input multiple output (MIMO) systems, generalized spatial modulation (GSM) techniques have been proposed in the literature. In this paper, we propose a zero-forcing (ZF)-based detector, which performs an initial pruning of the search tree that will be considered as the initial condition in a sphere decoding (SD) algorithm. The proposed method significantly reduces the computational complexity of GSM systems while achieving a near maximum likelihood (ML) performance. We analyze the performance of the proposed method and provide an analytic performance difference between the proposed method and the ML detector. Simulation results show that the performance of the proposed method is very close to that of the ML detector, while achieving a significant computational complexity reduction in comparison with the conventional SD method, in terms of the number of visited nodes. We also present some simulations to assess the accuracy of our theoretical results.