• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11A
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• pp.912-923
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• 2011

In this paper, we propose a routing protocol for WMNs to provide passengers in public transportation vehicles (e.g., bus and tram) with Internet access service. In order to support end users with a reliable Internet connection despite the mobility of vehicles, we assume that mesh router, called mobile mesh router (MMR), is installed in a vehicle and manages a route to Internet Gateway (IGW). We therefore propose an efficient routing protocol and its routing metric, called ETT-TR, considering trajectory information of vehicle as well as link quality in order to find a route between them. Using NS-2 simulations, we observe that our proposed routing protocol reduces the end-to-end delay and improves throughput performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11A
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• pp.924-932
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• 2011

In this paper, we propose a possibility of usage of carrier superpositioning scheme for a specific slow frequency hopping(SFH) transmission method for the satellite data link in which all of hopping carriers have to be synchronized to DSM transponder of our previous work and usage of frequency diversity in the saved frequency to overcome the SFH disadvantage against jammer. We have analyzed anti-jamming performance and LPI performance and confirmed that the proposed scheme can support data service with 18.5dB processing gain against the worst case partial band jamming and give 2.5dB gain in the LPI performance against D&M detector which can estimate the data rate of unknown signals.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.2
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• pp.443-461
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• 2014

Overlay routing has emerged as a promising approach to improve reliability and efficiency of the Internet. For one-hop overlay source routing, when a given primary path suffers from the link failure or performance degradation, the source can reroute the traffic to the destination via a strategically placed relay node. However, the over-heavy traffic passing through the same relay node may cause frequent package loss and delay jitter, which can degrade the throughput and utilization of the network. To overcome this problem, we propose a Load-Balanced One-hop Overlay Multipath Routing algorithm (LB-OOMR), in which the traffic is first split at the source edge nodes and then transmitted along multiple one-hop overlay paths. In order to determine an optimal split ratio for the traffic, we formulate the problem as a linear programming (LP) formulation, whose goal is to minimize the worse-case network congestion ratio. Since it is difficult to solve this LP problem in practical time, a heuristic algorithm is introduced to select the relay nodes for constructing the disjoint one-hop overlay paths, which greatly reduces the computational complexity of the LP algorithm. Simulations based on a real ISP network and a synthetic Internet topology show that our proposed algorithm can reduce the network congestion ratio dramatically, and achieve high-quality overlay routing service.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1121-1125
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• 2004

The RT(Robot Technology) has been developed as the next generation of a future technology. According to the 2002 technical report from Mitsubishi R&D center, IT(Information Technology) and RT(Robotic Technology) fusion system will grow five times larger than the current IT market at the year 2015. Moreover, a recent IEEE report predicts that most people will have a robot in the next ten years. RCP(Robotic Cellular Phone), CP(Cellular Phone) having personal robot services, will be an intermediate hi-tech personal machine between one CP a person and one robot a person generations. RCP infra consists of $RCP^{Mobility}$, $RCP^{Interaction}$, $RCP^{Integration}$ technologies. For $RCP^{Mobility}$, human-friendly motion automation and personal service with walking and arming ability are developed. $RCP^{Interaction}$ ability is achieved by modeling an emotion-generating engine and $RCP^{Integration}$ that recognizes environmental and self conditions is developed. By joining intelligent algorithms and CP communication network with the three base modules, a RCP system is constructed. Especially, the RCP interaction system is really focused in this paper. The $RCP^{interaction}$(Robotic Cellular Phone for Interaction) is to be developed as an emotional model CP as shown in figure 1. $RCP^{interaction}$ refers to the sensitivity expression and the link technology of communication of the CP. It is interface technology between human and CP through various emotional models. The interactive emotion functions are designed through differing patterns of vibrator beat frequencies and a feeling system created by a smell injection switching control. As the music influences a person, one can feel a variety of emotion from the vibrator's beats, by converting musical chord frequencies into vibrator beat frequencies. So, this paper presents the definition, the basic theory and experiment results of the RCP interaction system. We confirm a good performance of the RCP interaction system through the experiment results.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.6
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• pp.365-378
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• 2020

The study aims to develop concepts originating through empirical research models to build superior competitiveness and optimal performance achievement. Therefore, to bridge these goals, the study addresses several indicators/items as a novelty, namely, entrepreneurship insight factors, market orientation, knowledge-sharing, innovation, managerial capability, product strategy, process and service improvement, resources capability to improve performance and increase competitiveness by empirical model direct, mediating and indirect effect. The total sample in this study is 497 eligible SMEs that partner with go-food in Makassar City. All research samples are the owner or the person in charge of the business; the data collection period is from May to December 2019. Data are collecting using a survey with 64 construct questions, summarized in seven manifest variables. The research method uses quantitative tools, with SMART-PLS as a statistical tool. This study develops sixteen hypotheses; all of the hypotheses are supported both directly, indirectly, and mediated. The study also found that the link based on CCT, RBV, and TAM Theory is the right choice of theories, as the foundation of this study was very reliable and valid. Indeed, all of the grounded methods have implications both in theory and its main application for the business in the online marketplace.

• Journal of Broadcast Engineering
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• v.22 no.5
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• pp.652-664
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• 2017

The practice of producing and transmitting TV programs with uneven loudness can harm audiences' welfare in the digital environment where audiences are entitled to be offered quality broadcasting service. The purpose of this paper is to investigate issues concerning the digital loudness policy institutionalized in Korea since May 2016, and to offer policy suggestions. This paper reviews previous studies on audience welfare in digital broadcasting, focusing on the close link between loudness policy and audience welfare. In order to explore the state of international policy, this paper examines loudness standards developed by international standardization organizations including ITU, ATSC, and EBU, along with loudness regulations in the US, the UK, Canada, Australia, Japan, and Korea, respectively. Based on the analysis, this paper suggests recommendations for policy makers and broadcasters. First, policies on mandating regular monitoring and establishing penality system should be established for broadcasters not to violate loudness standards. Second, broadcasters are recommended to collect audience feedback, to be equipped with loudness measuring devices, to offer personnel training programs, and to check the compliance of loudness standards when they outsource TV programs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.2
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• pp.620-636
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• 2015

Survivability is a necessary property of network system in disturbed environment. Recovery ability is a key actor of survivability. This paper concludes network survivability into a novel composite metric, i.e. Network Recovery Degree (NRD). In order to measure this metric in quantity, a concept of Source-Destination Pair (SD Pair), is created to abstract end-to-end activity based on end nodes in network, and the quality of SD Pair is also used to describe network performance, such as connectivity, quality of service, link degree, and so on. After that, a Survivability Test method in large scale Network based on SD pairs, called STNSD, is provided. How to select SD Pairs effectively in large scale network is also provided. We set up simulation environment to validate the test method in a severe destroy scenario and evaluate the method scalability in different large scale network scenarios. Experiment and analysis shows that the metric NRD correctly reflects the effort of different survivability strategy, and the proposed test method STNSD has good scalability and can be used to test and evaluate quantitative survivability in large scale network.

• Journal of The Korean Association of Information Education
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• v.9 no.1
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• pp.27-37
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• 2005

Advances in the wireless Internet have led to the rise of diverse techniques which can access information regardless of time and place. There are many research efforts to identify the various ways to use a cellular phone in our everyday life. However, it has been rarely used in the elementary school. As an attempt to apply the wireless Internet technology to the elementary school, this study is to design and implement a wireless Internet homepage where the parents would be able to have an easy access to the information any place and any time. The characteristics of the wireless Internet homepage are as follows; first, the images were reduced to the minimum and the text-oriented information is mostly used to deliver the key information, considering the small screen and relatively slow transmission rates. Second, by providing a link set up between the wireless homepage and the wired Internet homepage, users can choose the more convenient access tool. Finally, the SMS (Short Message Service) messages could be used for an immediate delivery of information.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.3
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• pp.256-261
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• 2013

The AIS(Automatic Identification System) has been widely used for ship safety at sea over the last 10 years. The AIS traffic load at VDL(VHF Data Link) has been continuously increased. As the traffic load at VDL increases, the quality of AIS service may be deteriorated. In the previous research, the AIS traffic has been analyzed in the major ports of Korea, and its problem due to traffic overload has been suggested. However, no solutions has been given so far. In this paper, the method of autimatically controlling the VDL traffic at AIS base station is represented.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.1
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• pp.34-39
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• 2005

In this paper, we propose a new prioritized Optical Burst Switching (OBS) protocol based on a hop count, which can provide an efficient utilization in optical Wireless networks. Under several legacy schemes, a switch drops the burst with a shorter time among ones regardless of its traversed hop count. As a result, the dropped burst that have been traversed more hops might cause to waste bandwidth than the one traversed a few hops. Noting that this problem, we propose the Just Enough Time(JET) with a hop count scheme which can reduce the wasted bandwidth by prioritizing the burst traversed more hops over others. From the simulation result, we show that the proposed scheme is advantageous over the legacy schemes in terms of the burst blocking probability and the link utilization.