• Journal of Communications and Networks
• /
• v.8 no.1
• /
• pp.116-122
• /
• 2006

Most of the multimedia applications require strict quality of service (QoS) guarantee during the communication between a single source and multiple destinations. This gives rise to the need for an efficient QoS multicast routing strategy. Determination of such QoS-based optimal multicast routes basically leads to a multi-objective optimization problem, which is computationally intractable in polynomial time due to the uncertainty of resources in Internet. This paper describes a network model for researching the routing problem and proposes a new multicast tree selection algorithm based on genetic algorithms to simultaneously optimize multiple QoS parameters. The paper mainly presents a QoS multicast routing algorithm based on genetic algorithm (QMRGA). The QMRGA can also optimize the network resources such as bandwidth and delay, and can converge to the optimal or near-optimal solution within few iterations, even for the networks environment with uncertain parameters. The incremental rate of computational cost can close to polynomial and is less than exponential rate. The performance measures of the QMRGA are evaluated using simulations. The simulation results show that this approach has fast convergence speed and high reliability. It can meet the real-time requirement in multimedia communication networks.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.23 no.8
• /
• pp.1941-1951
• /
• 1998

In this paper, hardware circuit that performs functions of IEEE 802.11 wireless LAN frequency hopping PLCP protocol is designed using 0.8 um CMOS cmn8a technology of the COMPASS. Transmission rate of the designed hardware is 1Mbps. The designed circuit have about 6300 gates and $2.5{\times}2.5mm^2$ area. In order to verify the circuit, two PLCP circuits are interconnected and frames are transmitted from one PLCP circuit to the other PLCP circuit. As a results of the simulation, we conclude that the designed PLCP circuit works well as the IEEE 802.11 standard specification.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.05a
• /
• pp.487-490
• /
• 2011

As international standards of ICT were recently recognized as a essential strategy to penetrate into global markets in advance, the competition for international standardization among advanced countries and companies has been intensified. Also, the convergence of ICT and other industry as well as that of ICT and broadcasting has caused the expansion of range and importance in standardization. It is necessary to set up the strategy of standardization on essential technology and implement it systematically in order to take leading position in global market of IC in smart information society of the 21th century. Therefore, in this paper, I'll suggest constructive strategies of standardization through analyzing the trend and environment of IC standardization.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37C no.10
• /
• pp.986-992
• /
• 2012

As the utilization of smart mobile devices such as smartphones increases, the desire to utilize such devices to control and monitor combat situations also arises. As smart mobile devices with various ICT get integrated with various weaponry system, a new phase of future warfare can be introduced. Moreover, smartphone-based real-time information technology for joint battle command system will be converged with surveillance control to become a leading example of convergence of cyber defense and information technology. Furthermore, mobile device security technology ideal for mobile wireless network environments can be applied to military robots. The following paper will give an overview of smart mobile device usage used for military purposes in battle command system, various security threats and the mobile device security technology to correspond to such security threats.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.9
• /
• pp.1057-1059
• /
• 2016

A construction method of energy-efficient data aggregation tree is proposed by considering a tradeoff between acquisition time and energy consumption in wireless sensor networks. This proposed method constructs the data aggregation tree to minimize the link cost between the connected nodes for reducing energy consumption, while minimizing the maximum distance between sensor nodes and a sink node for rapid information gathering. Simulation results show that the proposed aggregation tree can be generated with low complexity and achieves high energy efficiency compared to conventional methods.

• Journal of Digital Convergence
• /
• v.14 no.9
• /
• pp.265-279
• /
• 2016

The purpose of study was to test the effects of job characteristics and job stress on job satisfaction in the ICT Convergence Venture Companies and the moderating role of social support between job characteristics and job satisfaction. For this study, the data were collected from 15 ICT Convergence Ventures in metropolitan area by using structured questionnaires. The sample of 301 employees was selected and analyzed by hierarchical regression technique. The results showed that job characteristics had a positive effect on job satisfaction and job stress had a negative effect. And also found out social support had the moderate roles between job stress and job satisfaction except coworker support with regard to role ambiguity, whereas it did not serve as a moderate role between job characteristics and job satisfaction. The research results are summarized, the implications for ICT convergence Ventures were discussed, and the directions for future research were suggested.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.12
• /
• pp.1868-1875
• /
• 2016

This paper presents the mega trends of technology and competitiveness analysis results based on patent analysis for establishing effective research and development (R&D) strategy on UAV (Unmanned Aerial Vehicle) in the aerial ICT industry. In order to analyze mega trends of UAV technologies, patent analysis is conducted focusing on published/registered patents of Korea, the U.S., Japan, and Europe. We divided the target technologies into 3 main category levels based on the converging technology of UAV and ICT. The 3,433 patents are collected. Patent indicators such as patent activity (PA), cites per patent (CPP), and major market expansion (MME) are extracted for grasping the technology competitiveness and Korea's competitiveness per sub category levels of UAV. We suggest the R&D strategy of each technology areas based on patent analysis results. We analyzed Korea's technology levels, advanced companies' R&D trends, and patent trends through patent information and expected that this paper would be utilized for establishment of R&D strategy of UAV in the future.

• Journal of Convergence for Information Technology
• /
• v.8 no.6
• /
• pp.193-199
• /
• 2018

The commonly used delivery system for online merchandise has potential problems, not only missing but also criminal case. Also, the contemporary Kiosk type approach for delivery system has some problems in an initial installation cost, expense of management system and especially security weaknesses in the wireless communication. To resolve these issues, this paper is proposing a securely unmaned smart locker system that can handle up to 64 parcels. This is easily controlled and monitored by a smartphone. In addition to the system, an algorithm is proposed to make the security of wireless communications better. Finally, a method is proposed to minimize the cost of delivery by using centralized server.

• Journal of Internet of Things and Convergence
• /
• v.2 no.1
• /
• pp.35-40
• /
• 2016

One of the next generation of automotive V2V communication technology is a core technology for next-generation ITS as a technique used for communications between the vehicle. Looking at the existing V2V communication using the pseudonym certificate authentication service structure to meet the security requirements for privacy protection. Since the issuance of multiple certificates when needed authority in issuing and managing to use the pseudonym certificate issued once and it takes a lot of time. In this paper, we present the method utilizing a vehicle ID to meet the security requirements for the privacy protection without the use of a pseudonym certificate.

• Current Photovoltaic Research
• /
• v.3 no.4
• /
• pp.135-139
• /
• 2015

$Cu_2SnS_3$ (CTS) based thin film solar cells (TFSCs) are of great interest because of its earth abundant, low-toxic and eco-friendly material with high optical absorption coefficient of $10^4cm^{-1}$. In this study, the DC sputtered precursor thin films have been sulfurized using rapid thermal annealing (RTA) system in the graphite box under Ar gas atmosphere for 10 minute. The systematic variation of sulfur powder during annealing process has been carried out and their effects on the structural, morphological and optical properties of CTS thin films have been investigated. The preliminary power conversion efficiency of 1.47% with a short circuit current density of $33.9mA/cm^2$, an open circuit voltage of 159.7 mV, and a fill factor of 27% were obtained for CTS thin film annealed with 0.05g of S powder, although the processing parameter s have not yet been optimized.