• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.4A
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• pp.296-303
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• 2005

In this paper, we evaluate system performance and propose signal separation and detection when a user with one antenna shares the co-channel together with a user with two space-time coded antennas. The proposed technique can identify co-channel users by an interference cancellation method and detect the signals by maximum likelihood method. Simulation results show that the shortcoming of the Minimum Mean-Squared Error technique which can be applied two users with the same number of antenna but can not applied for heterogeneous MIMO users with the different number of antennas. Also, we apply the proposed scheme to OFDM system and evaluate the system performance. By simulations, we identify that the performance of the proposed system is the same as that of the existing single antenna users and improves the performance of the two-antenna MIMO users.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.4
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• pp.107-114
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• 2014

Things in the IoT(Internet of Things) make various services by exchanging information over networks. The IoT includes many types of WSNs(Wireless Sensor Networks) that consists of spatially distributed wireless sensor nodes and operates with the various purposes with useful technologies such as identification, sensing and communication. Typically, Zigbee network composed of low-cost and lowpower devices is mainly used for wide-area monitoring and remote device control systems. The IoT composed of various WSNs cannot interoperate among networks because of heterogeneous communication protocol and different data representation of each network, but can facilitate interconnection and information exchange among networks via the DDS, which is communication middleware standard that aims to enable real-time, high performance and interoperable data exchanges. In this paper, we proposed design of Zigbee Adaptor for two-way interoperation and data exchange between Zigbee network and other networks in the IoT. Zigbee Adaptor communicates with Zigbee network according to the Zigbee protocol and communicates with external networks via DDS. DDS-based Zigbee Adaptor can facilitate interoperation between a Zigbee network and external networks by systematic cooperation among its components.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.11
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• pp.2047-2058
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• 2007

The business environment of enterprises could be difficult to obviate redundancy to filtrate data source occurred on data integrated to standard rules and meta-data and to produce integration of data and single viewer in geographical and spatial distributed environment. Specially, To can interchange various data from a heterogeneous system or various applications without types and forms and synchronize continually exactly integrated information#s is of paramount concern. Therefore data hub system based on SQL/XMDR message to overcome a problem of meaning interoperability occurred on exchanging or jointing between each legacy systems are proposed in this paper. This system use message mapping technique of query transform system to maintain data modified in real-time on cooperating data. It can consistently maintain data modified in realtime on exchanging or jointing data for cooperating legacy systems, it improve clarity and availability of data by providing a single interface on data retrieval.

• Korean Journal of Plant Resources
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• v.32 no.4
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• pp.325-337
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• 2019

This study was conducted to analyze character of distribution of plants by landforms and altitude in Mt. myeonbong. The chemical properties of soil in this study sites were as follows; pH 4.86, organic 52.53 g/kg, $P_2O_5$ 7.57 mg/kg, potassium $0.18cmol^+/kg$, calcium $2.45cmol^+/kg$ and magnesium $0.49cmol^+/kg$. Generalists in the upper layer were analyzed as follows; Quercus mongolica, Pinus densiflora, Quercus variabilis, and specialists; Carpinus cordata, Tilia amurensis, Morus bombycis etc. In the middle layer, generalists were Betula schmidtii, Quercus mongolica, Sorbus alnifolia and specialists; Lindera erythrocarpa, Quercus serrata, Staphylea bumalda etc. Generalist of shrubs; Lindera obtusiloba, Rhododendron mucronulatum, Sorbus alnifolia, and specialists; Morus bombycis, Pinus densiflora, Deutzia glabrata etc. Generalists of herbaceous layer; Rhus tricocarpa, Lespedeza maximowiczii, Polygonatum odoratum var. pluriflorum and specialists; Liparis kumokiri, Davallia mariesii and Chrysosplenium flagelliferum etc.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.530-542
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• 2021

To establish the basic unit for the ecological management of the Larix kaempferiplantations in the Baekdudaegan protected area, we classified the vegetation types using TWINSPAN and DCA ordination analysis based on the vegetation information collected from 119 plots and analyzed their spatial arrangement status. Vegetation types were classified into seven types, including Quercus mongolica-Rhododendron schlippenbachii type, Q. mongolica-Lespedeza maximowiczii type, Cornus controversa-Morus australis type, Q. mongolica-Carpinus cordata type, Lindera erythrocarpa-Rosa multiflora type, Q. serrata-Zanthoxylum schinifolium type, and Q. serrata-Sasa borealis type and they have usually reflected differences in the floristic composition according to latitude, elevation, establishment period, operation history, characteristics of the surrounding stands, and degree of disturbance. Furthermore, using the Jaccard coefficient to comparethe floristic composition similarity between Larix kaempferiplantations and surrounding potential natural vegetation (Q. mongolica and Q. serrata forests), although some differences depended on vegetation types, it was 0.21 on average with Q. mongolica forest and 0.32 with Q. serrata forest, indicating that the floristic composition was still heterogeneous.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4D
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• pp.443-450
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• 2009

Uninterrupted facility - since there is a close relationship between traffic volume, speed and density -, when a ramp traffic flow merges into the main line, will change the traffic speed or density, and the corresponding correlational model equation will be changed. Thus, this study, using time and space-series traffic data on areas under the influence of such a merging, identified sections which changed the correlation between speed and density variables, and examined such changes. As a result, the upstream and merging sections showed the "Underwood"-shaped exponent, and the downstream after passing the merging section showed a straight line "Greenshields" model. The downstream section which changed the correlation between speed and density showed a gradual downstream movement phenomenon within 100 m-500 m from the end of the third lane linking with the ramp, as the traffic approached the inner lanes. Also, the upstream section, merging section, and downstream section involving a change showed heterogeneous traffic flows which, in the speed-density model, have a statistically different free flow speed (constant) and a different ratio of free flow speed to jam density (gradient).

• Archives of design research
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• v.18 no.2 s.60
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• pp.143-154
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• 2005

Typography in visual communication design is 'potential form' hidden within a space. Showing rhythm in typography is making 'aesthetic sense' in a graphic which has formative characteristics, the way of expression is very important. When the rhythm is recognized through visual stream, Rhythmic Sense is formed. The research will present a new form of the Visual Rhythmic Sense by analyzing typography works out positively. First of all, I researched works done by Fillippo Marinetti, Robert Massin, Wolfgang Weingart, and David Carson for their vigorous experimentalism in typography in forming visual rhythm. I used S.D. Scale method to analyze characteristics of visual image and VARIMAX for factor analysis reaching types of visual rhythm, which could be classified as following. (1) Synesthesia Rhythmic Sense (R-synesthesia) means that the senses are conveyed through 'visualization of auditory sense' and 'visualization of touch' (2) Simultaneous Rhythmic Sense (R-simultaneity) means that the time and space co-exist in one plane. (3) Connective Rhythmic Sense(R-connection) means that different factors (Within one plane) co-exist interacting with one another and creating a unified impression through such a process. (4) Artist Oriented Rhythmic Sense ($-artist) means that the artist interprets the content subjectively and expresses his/her impression, thereby, attracting a gaze of audience systematically and arbitrarily. (5) Reader Oriented Rhythmic Sense(R-reader) avoids the existing legibility formed through aggressive engagement of the reader.

• Korean Journal of Plant Resources
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• v.33 no.1
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• pp.1-14
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• 2020

This study was conducted to analyze community structure and species composition of Pinus densiflora for. erecta Stand in Mt. Cheonchuk (653 m). Field survey was carried out from June to September in 2013. 74 plots (20×20 m) were set up, 5 herb layer plots (3×3 m) were constructed for each plot, and there, Diameter at Breast Heigh t(DBH), height, environmental factor, annual growth were measured. Vascular plants were surveyed as following; 66 family, 165 genus, 211 species, 2 sub species, 29 variety, 6 form 248 taxa. Results of cluster analysis for P. densiflora for. erecta forest, 3 communities were divided into; Quercus mongolica (P-1), Quercus variabilis (P-2) and Quercus aliena-Stephanandra incisa (P-3). There were significant environmental factors that organic layer, annual growth, CEC, total total nitrogen, organic matter and pH for each community. As a result of DCA, P-1 and P-2 were distributed large range of environmental factors but relatively limited in P-3. Distributions of herb layer were affected by sand, cation exchange capacity, silt and total nitrogen. Results of MRPP test for herb layer communities, it was significantly analyzed (A=0.003, P<0.008). Species diversity index was highly recorded in P-3 and influenced by cation exchange capacity, total nitrogen, annual growth in consequence of NMS analysis.

• Journal of the Korean Geographical Society
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• v.49 no.3
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• pp.405-422
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• 2014

Two important issues in hedonic model are to specify accurate model and delineate submarkets. While the former has experienced much improvement over recent decades, the latter has received relatively little attention. However, the accuracy of estimates from hedonic model will be necessarily reduced when the analysis does not adequately address market segmentation which can capture the spatial scale of price formation process in real estate. Placing emphasis on improvement of performance in hedonic model, this paper tried to segment real estate markets in Gangnam-gu and Jungrang-gu, which correspond to most heterogeneous and homogeneous ones respectively in 25 autonomous districts of Seoul. First, we calculated variable coefficients from mixed geographically weighted regression model (mixed GWR model) as input for clustering, since the coefficient from hedonic model can be interpreted as shadow price of attributes constituting real estate. After that, we developed a spatially constrained data-driven methodology to preserve spatial contiguity by utilizing the SKATER algorithm based on a minimum spanning tree. Finally, the performance of this method was verified by applying a multi-level model. We concluded that submarket does not exist in Jungrang-gu and five submarkets centered on arterial roads would be reasonable in Gangnam-gu. Urban infrastructure such as arterial roads has not been considered an important factor for delineating submarkets until now, but it was found empirically that they play a key role in market segmentation.

• Spatial Information Research
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• v.5 no.2
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• pp.147-160
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• 1997

"The "Map Algebra", beeing recognized as a viable theoretical framework for GIS (Geographica Infonnation System), models map layers as "operands" which are the basic unit of geo-processing, and a variety of GIS commands as "operators." In this paper, we attempt at lifting some limitations of map algebras proposed in GIS literature. First, we model map layer as "function" such that we may employ the notion of meta operator (or, higher-order funtion) available in the functional programming paradigm. This approach provides map algebraic language with "programmability" needed in GIS user language. Second, we extend the semantics of, and improve on the sytactic structure of map algebraic language. Mer the data model and language associated with map algebra are formalized, we proceed to design and implement a prototype of map algebraic processor. The parser of the language in our prototype plays the role of transforming the native and heterogeneous user language of current GISs into a canonical map algebraic language. The prototype, named "MapSee" is a proof-of-concept system for the ideas we propsed in this paper. We believe that the uniform interface based on the map algebraic language will make promising infrastructure to support "Internet GIS." This is because the uniform but powerful interface through the Web clients allow access to both geo-data and geo-processing resources distributed over the network.to both geo-data and geo-processing resources distributed over the network.