• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.5
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• pp.368-376
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• 2013

The importance of application traffic identification is emphasized for the efficient network management with recent rapid development of internet. In this paper, we present the application traffic identification method using the behavior based signature to improve the previous limitations. The behavior based signature is made by combining the existing various traffic features, and uses the Inter-Flow unit that is combination of the first request packet of each flow. All signatures have 100% precision when measured the accuracy of 5 applications using at home and abroad to prove the feasibility of the proposed signature.

• Journal of Information Management
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• v.24 no.3
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• pp.31-56
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• 1993

In order to respond to the public needs to utilize the newspapers as high-valued information resources, the number of the commercially available news items which are transformed into a form of database has been remarkably increased by the introduction of CTS into the newspaper companies. As for the domestically available Japanese and foreign newspaper article database, explanations are given to the following items. 1) Characteristics of database, such as date of coverage, frequency updating, time-lag, news sources, search terms, available information, etc. 2) Matters to be noticed at the utilization. 3) Pattern of utilization depending on the object of the investigation, such as the investigation of company, market trend, etc. Since the newspaper article database will be available in a form of digitized information, making the combination with the inter-company LAN system possible, increased opportunities to use it in near future are expected.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1218-1227
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• 2004

Multi-domain engineering systems include electrical, mechanical, hydraulic, pneumatic, and thermal components, making it difficult to design a system because of their complexity and inter domain nature. In order to obtain an optimal design, a unified design approach for each domain and an automated search method are required. This paper suggests a method for automatically synthesizing designs for multi-domain systems using the combination of bond graph that is domain independent and genetic programming that is well recognized as a powerful tool for open-ended search. To investigate the effect of proposed approach, an eigenvalue design problem is tested for some sample target sets of eigenvalues with different embryos.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.7B
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• pp.606-612
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• 2012

Visible light communications (VLC) uses modern solid-state LEDs to broadcast information. Emerging white-light LEDs allows the combination of lighting and optical wireless communication in one optical source. In this paper, a new LED lighting using one-chip-type white LED is proposed for efficient illumination and optical wireless communications. Performance analysis such as horizontal illuminance, 3-dB cut-off frequency, inter-symbol interference, signal-to-noise ratio and bit-error rate shows the effects of the shapes of LED lighting. Performance of the proposed LED lighting under the existence of obstacles is superior to that of the existing LED lighting in illumination and optical wireless communication.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.6A
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• pp.624-631
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• 2007

This paper presents inter-cell cooperation methods with two transmit antennas for broadcast services in a coded OFDM cellular system. In the method, cells are divided into multiple cell groups and a coded packet is partitioned into the subparts. Then, a different cell group and antenna combination is assigned to each subpart for transmission of two orthogonal branches of the diversity code. For the method, we derive the bound on the pairwise error probability to predict the coded performance and verify the performance gain of the proposed method through the simulation using turbo code and analytically derived bound.

• Journal of Communications and Networks
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• v.15 no.1
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• pp.8-14
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• 2013

For alleviating the low spectrum efficiency problem of orthogonal frequency division multiplexing (OFDM), due to the strong inter-cell-interference (ICI) at cell's edge, we introduce comb-spectrum code division multiple access (CS-CDMA) into broadband OFDM system at downlink channel for enabling the use of entire spectrum for seamless coverage. In addition, we develop a new method, called orthogonal cell code (OCC) scheme, to assist CS-CDMA for nullifying the ICI from contiguous cells. In system operation, each of the conventional cells is divided into an outer cell and an inner cell, and a mobile station (MS) should access to the CS-CDMA when it is in the outer cell and access to OFDM when it is in the inner cell. This study investigates the spectrum efficiency of using CS-CDMA and makes a comparison with that of long term evolution (LTE) in the following cases; (1) under an assumption of perfect channel state information and (2) based on channel estimates at a MS station. The results show the great advantage of utilizing the proposed system.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.90.2-90.2
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• 2013

Vertically-aligned silicon nanostructure arrays (SNAs) have been drawing much attention due to their useful electrical properties, large surface area, and quantum confinement effect. SNAs are typically fabricated by chemical vapor deposition, reactive ion etching, or wet chemical etching. Recently, metal-assisted chemical etching process, which is relatively simple and cost-effective, in combination with nanosphere lithography was recently demonstrated for vertical SNA fabrication with controlled SNA diameters, lengths, and densities. However, this method exhibits limitations in terms of large-area preparation of unperiodic nanostructures and SNA geometry tuning independent of inter-structure separation. In this work, we introduced the layerby- layer deposition of polyelectrolytes for holding uniformly dispersed polystyrene beads as mask and demonstrated the fabrication of well-dispersed vertical SNAs with controlled geometric parameters on large substrates. Additionally, we present a new means of building in vitro neuronal networks using vertical nanowire arrays. Primary culture of rat hippocampal neurons were deposited on the bare and conducting polymer-coated SNAs and maintained for several weeks while their viability remains for several weeks. Combined with the recently-developed transfection method via nanowire internalization, the patterned vertical nanostructures will contribute to understanding how synaptic connectivity and site-specific perturbation will affect global neuronal network function in an extant in vitro neuronal circuit.

• The Journal of the Acoustical Society of Korea
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• v.38 no.5
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• pp.587-592
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• 2019

ISI (Inter Symbol Interference) reduces the performance of UAComm (Underwater Acoustic Communication). This paper shows that the performance of UAComm can be improved through the spatiotemporal diversity method that is the combination of spatial diversity and temporal diversity methods. By using spatiotemporal diversity, the array aperture was reduced to increase the efficiency of the UAComm system. It is also verified using the experimental data of BLAC18 (Biomimetic Long range Acoustic Communication 18) conducted in October 2018.

• Journal of Information Processing Systems
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• v.17 no.5
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• pp.947-959
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• 2021

Aiming at the problem of low accuracy in the water boundary automatic extraction of islands from GF-2 remote sensing image with high resolution in three bands, new water edges automatic extraction method in island based on GF-2 remote sensing images, genetic algorithm (GA) method, is proposed in this paper. Firstly, the GA-OTSU threshold segmentation algorithm based on the combination of GA and the maximal inter-class variance method (OTSU) was used to segment the island in GF-2 remote sensing image after pre-processing. Then, the morphological closed operation was used to fill in the holes in the segmented binary image, and the boundary was extracted by the Sobel edge detection operator to obtain the water edge. The experimental results showed that the proposed method was better than the contrast methods in both the segmentation performance and the accuracy of water boundary extraction in island from GF-2 remote sensing images.

• Environmental Engineering Research
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• v.24 no.2
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• pp.220-237
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• 2019

Solid waste management (SWM) is one of the poorly rendered services in developing countries - limited resources, increasing population, rapid urbanization and application of outdated systems leads to inefficiency. Lack of proper planning and inadequate data regarding solid waste generation and collection compound the SWM problem. Decision makers need to formulate solutions that consider multiple goals and strategies. Given the large number of available options for SWM and the inter-relationships among these options, identifying SWM strategies that satisfy economic or environmental objectives is a complex task. The paper develops a mathematical model for a municipal Integrated SWM system, taking into account waste generation rates, composition, transportation modes, processing techniques, revenues from waste processing, simulating waste management as closely as possible. The constraints include those linking waste flows and mass balance, processing plants capacity, landfill capacity, transport vehicle capacity and number of trips. The linear programming model integrating different functional elements was solved by LINGO optimization software and various possible waste management options were considered during analysis. The model thus serves as decision support tool to evaluate various waste management alternatives and obtain the least-cost combination of technologies for handling, treatment and disposal of solid waste.