• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.5
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• pp.78-89
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• 2022

Super - Bus Rapid Transit (S-BRT), adding the advantages of urban railroads to BRT, has emerged to solve the problem of low speed and reliability of the existing BRT. Notably, the S-BRT driveway is classified into exclusive lanes and roads, as BRT, in the domestic guidelines. However, S-BRT and BRT have different operating goals and characteristics, so it is necessary to systematize the S-BRT driveway. Therefore, this study classified an S-BRT driveway into exclusive lane, shared lane with overtaking lane, and shared lane without overtaking lane based on domestic conditions. Subsequently, a control strategy for transit signal priority in each driveway was presented by the study based on the characteristics of the driveway to achieve the S-BRT target service level. Finally, the S-BRT target service level was almost achieved, and the travel speed was high and increased in the order respectively in the exclusive lane, shared lane with overtaking lane, and shared lane without overtaking lane in the study. Hence, it is important to operate a transit signal priority considering the characteristics of each driveway when operating the S-BRT. In essence, this study is expected to be used as a reference for driveway design and transit signal priority operation when introducing S-BRT in each local government in the future.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.778-780
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• 2002

The TLS protocol suite, which provides transport-layer security far the Internet, has been standardized in the IETF. A TLS session is an association between a client and a server, created by the TLS handshake Protocol. Sessions define a set of cryptographic securi쇼 parameters, which can be shared among multiple connections. The TLS protocol, however, does not address the specific method fur how to manage the existing TLS sessions on the host. This paper proposes an efficient management scheme TLS, based on the principles of trust management.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1282-1288
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• 2008

In the early 1990s, the market-orientation attracting a lot of attention as the implementation strategy of marketing is an effort to give customers a value and get sustained earnings in the market. In the previous studies, most of the studies on the market-orientation have focused on hotels, large companies and IT, so it was hard to find the study on railroad in the view of transport service. Thus, this study aimed to find out how marketing activities using transport service and a variety of products linked railroad are shared by group members and what effect the organized union of corporate culture has on business performance as market-orientation activity. Previously, the purpose of this study was to research whether the management system of a private enterprise based on market could be applied to the public enterprise like Korea railroad.

• Journal of the Korea Society for Simulation
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• v.7 no.1
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• pp.1-14
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• 1998

In this paper, we propose an efficient network communication scheme tailored to the network virtual reality(NVR) system. We first present the architecture and implementation of CVRAT (collaborative virtual reality authoring tool). The design goal of CVRAT is to provide consistent and scalable shared virtual environments. To achieve this goal, we classify the network messages according to their reliability and latency requirements. These conflicting requirements lead us to conceive a heterogeneous communication scheme which provides the unicast and three different multicast transport services; unreliable multicast, receiver-driven reliable multicast, fast reliable multicast. Each protocol has trade-offs in reliability, latency and bandwidth usage. The characteristics are analyzed by several experiments. Finally, applying this communication method to multi-participant battle-field tank simulation, we show the efficacy of proposed heterogeneous transport mechanism.

• Journal of Communications and Networks
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• v.12 no.3
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• pp.275-284
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• 2010

The current multihome-aware protocols (like stream control transmission protocol (SCTP) or parallel TCP for concurrent multipath data transfer (CMT) are not designed for high-capacity and large-latency networks; they often have performance problems transferring large data files over shared long-distance wide area networks. It has been shown that SCTP-CMT is more sensitive to receive buffer (rbuf) constraints, and this rbuf-blocking problem causes considerable throughput loss when multiple paths are used simultaneously. In this research paper, we demonstrate the weakness of SCTP-CMT rbuf constraints, and we then identify that rbuf-blocking problem in SCTP multihoming is mostly due to its loss-based nature for detecting network congestion. We present a simulation-based performance comparison of FAST TCP versus SCTP in high-speed networks for solving a number of throughput issues. This work proposes an end-to-end transport layer protocol (i.e., FAST TCP multihoming as a reliable, delaybased, multihome-aware, and selective ACK-based transport protocol), which can transfer data between a multihomed source and destination hosts through multiple paths simultaneously. Through extensive ns-2 simulations, we show that FAST TCP multihoming achieves the desired goals under a variety of network conditions. The experimental results and survey presented in this research also provide an insight on design decisions for the future high-speed multihomed transport layer protocols.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.5
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• pp.119-137
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• 2020

Over the last two decades, the attitudes to cars have changed from buying a car to sharing a car, especially among young people. Shared transport services and autonomous vehicles together can resolve the accessibility issue of shared transport services. Furthermore, they will make it possible to develop a new model of apartments without car parking. Therefore, the study estimated the demand for car sharing by young people and the running efficiency of car-sharing dealing with their car-based trip demand. The study chose nine apartment complexes for study sites where a majority of the residents were young people. The questionnaire survey was conducted to collect data on the trip demands of young people. The results showed that there are significant differences in the car-sharing use patterns and demand between the apartment houses located in the Capital region and non-capital region. Young people living in apartments in the Capital region used car sharing once per day per person for approximately 80 minutes per trip and tended to hire that between 8 AM and 10 AM. On the other hand, the young people living in apartments in the non-capital region used car sharing twice per day per person for approximately 200 minutes per trip. They tended to hire that frequently in the afternoon and evening as well as in the morning. The results also showed that a single car-sharing vehicle could deal with 3~4 trips per day in the Capital region and around 2 trips per day in the non-capital region.

• The Korean Journal of Physiology
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• v.22 no.2
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• pp.307-318
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• 1988

Properties of succinate transport were examined in basolaterat membrane vesicles (BLMV) isolated from rabbit renal cortex. An inwardly directed $Na^+$ gradient stimulated succinate uptake and led to a transient overshoot. $K^+,{\;}Li^+,{\;}Rb^+$ and choline could not substitute for $Na^+$ in the uptake process. The dependence of the initial uptake rate of succinate on $Na^+$ concentration exhibited sigmoidal kinetics, indicating interaction of more than one $Na^+$ with transporter Hill coefficient for $Na^+$ was calculated to be 2.0. The $Na^+-dependent$ succinate uptake was electrogenic, resulting in the transfer of positive charge across the membrane. The succinate uptake into BLMV showed a pH optimum at external pH $7.5{\sim}8.0$, whereas succinate uptake into brush border membrane vesicles (BBMV) did not depend on external pH. Kinetic analysis showed that a Na-dependent succinate uptake in BLMV occurred via a single transport system, with an apparent Km of $15.5{\pm}0.94{\;}{\mu}M$ and Vmax of $16.22{\pm}0.25{\;}nmole/mg{\;}protein/min$. Succinate uptake was strongly inhibited by $4{\sim}5$ carbon dicarboxylates, whereas monocarboxylates and other organic anions showed a little or no effect. The succinate transport system preferred dicarboxylates in trans-configuration (furmarate) over cis-dicarboxylates (maleate). Succinate uptake was inhibited by the anion transport inhibitors DIDS, SITS and furosemide, and $Na^+-coupled$ transport inhibitor harmaline. These results indicate the existence of a $Na^+-dependent$ succinate transport system in BLMV that may be shared by the other Krebs cycle intemediates. This transport system seems to be very similar to the luminal transport system for dicarboxylates.

• Journal of KIISE:Information Networking
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• v.27 no.1
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• pp.1-11
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• 2000

Recently, the explosive popularity of Internet gave birth to researches on Distributed Virtual Environments(DVE). They aim at providing a shared application data environment at realtime for users participating in the same application session across Internet. As more users join the session, and as more multimedia data are shared, because of network resource limitation, it is more difficult to maintain the quality of DVE, such as users' satisfaction level. Previous works mainly tried to solve the scalability, synchronization and data transport issues at the application level, with limited success. We suggest a new network centric solution, that consists of a novel network architecture and protocols upon which any large-scale DVE application can be easily developed. The performance of the proposed scheme, called GAIA, is verified by simulation.

• Health Policy and Management
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• v.28 no.3
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• pp.301-307
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• 2018

The development of transport is being easily shared with people all over the world. It is necessary to appropriately and effectively revise the domestic quarantine law because the fatal infectious diseases are at risk of being easily shared. Today, Korea has an advanced quarantine system approved by World Health Organization, but it maintains partnerships with related ministries (Ministry of Foreign Affairs, Ministry of Justice, local medical institutions) and to introduce new medical technology (electronic quarantine) is important. And since the prevention of quarantine infectious diseases and prevention of the spread, in order to maintain international cooperation with the International Health Regulations, the quarantine law and the system should be amended and improved effectively and it is also a way to prepare for the outbreak of new quarantine infectious diseases. In the past, Korea has experienced great confusion during the past outbreak of swine flu and Middle East respiratory syndrome coronavirus. To prevent similar cases from recurring in the past, the revision of the quarantine law and the improvement of the system should be done to cope with the changing environment (new infections, increased number of overseas travelers, etc.).

• Journal of the Society of Disaster Information
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• v.14 no.1
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• pp.59-64
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• 2018

In the trend of increasing awareness of chemical accidents, hazardous chemical transport vehicle accidents are occurring every year. In this study, we analyzed improvement of accident prevention and countermeasures through statistical analysis of hazardous chemical transport vehicle accidents. A total of 383 chemical accidents between January 2014 and December 2017 were analyzed. During this period, number of transportation accidents was 83 cases, accounting for 21.67% of total chemical accidents. In the current system, despite the direct handling of hazardous chemical, it is out of regulation of damage prediction unlike the workplace. In order to effectively respond to actual accident, information on damage prediction is required and should be shared with related ministry. And it should be developed to real-time monitoring of hazardous chemical transport vehicle through integrated control tower.