• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.6 no.1 s.12
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• pp.1-12
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• 2007

The objective of Bus Information System developed as a part of the ITS, provides the operation information of buses to passengers and managers. The system uses roadside antennas (reading electronic tags on board buses) to enable wireless communication each other and radio data communication to deliver information about buses and their locations. This information is used to estimate the arrival time of the bus which will be shown on the bus stop message board or via internet. Bus Information System or Bus Management System (BMS) is going ahead and set up in many local governments, and recently quality improvement of the BIS is considered as a very important element in expanding of business or management. Therefore this research wished to contribute rationalization of the system by maintaining optimum quality. An gang was chosen to apply overall quality control process and will be evaluated in terns of its propriety and performance. This study has led the improvement of service and promote the use of public transits, which is the best way to solve the city traffic problem by effective management of public transits.

• The KIPS Transactions:PartC
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• v.15C no.5
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• pp.429-438
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• 2008

NGN is a packet-based converged network to support session and non-session services in QoS-enabled broadband transport network. QoS based resource control must be defined to support differentiated services for various network users in NGN. We designed and implemented DIAMETER protocol as the Rs interface, and also defined mapping rules between DIAMETER information elements and SDP(Session Description Protocol) attributes for QoS based resource control in NGN. We selected and implemented DIAMETER protocol among alternate resource control protocols in ITU-T as the Rw interface because of simple interworking method with Rs interface and adequate AAA functionality. We defined mapping rules of messages and information elements between Rs and Rw interfaces for resource control from a service layer to a transport layer. Based on the mapping rule of QoS information elements and the interworking method between Rs and Rw interfaces, we built up a test-bed that support differentiated delivery services.

• Journal of Environmental Science International
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• v.25 no.7
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• pp.1029-1042
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• 2016

The initial and boundary conditions are important factors in regional chemical transport modeling systems. The method of generating the chemical boundary conditions for regional air quality models tends to be different from the dynamically varying boundary conditions in global chemical transport models. In this study, the impact of real time Copernicus atmosphere monitoring service (CAMS) re-analysis data from the modeling atmospheric composition and climate project interim implementation (MACC) on the regional air quality in the Korean Peninsula was carried out using the community multi-scale air quality modeling system (CMAQ). A comparison between conventional global data and CAMS for numerical assessments was also conducted. Although the horizontal resolution of the CAMS re-analysis data is not higher than the conventionally provided data, the simulated particulate matter (PM) concentrations with boundary conditions for CAMS re-analysis is more reasonable than any other data, and the estimation accuracy over the entire Korean peninsula, including the Seoul and Daegu metropolitan areas, was improved. Although an inland area such as the Daegu metropolitan area often has large uncertainty in PM prediction, the level of improvement in the prediction for the Daegu metropolitan area is higher than in the coastal area of the western part of the Korean peninsula.

• Journal of Korea Multimedia Society
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• v.12 no.5
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• pp.653-663
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• 2009

Synchronization between media is an important aspect in the design of multimedia communication-system. This paper proposes a precise media synchronization mechanism for video and audio transport over IP networks. To support synchronization between video and audio bitstreams transported over IP networks, RTP/RTCP protocol suite is usually employed. To provide a precise mechanism for media synchronization between video and audio, we suggest an efficient media synchronization algorithm based on NPT (Normal Play Time) which can be derivable from the timestamp information in the header part of RTP packet generated for the transport of video and audio. In the proposed method, we do not need to send and process any RTCP SR (sender report) packet which is required for conventional media synchronization scheme, and accordingly could reduce the number of required UDP ports and the amount of control traffic injected into the network.

• The KIPS Transactions:PartC
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• v.11C no.2
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• pp.245-252
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• 2004

Stream Control Transmission Protocol(SCTP) is a new connection-oriented, reliable delivery transport protocol operating on top of an unreliable connectionless packet service such as IP. It inherits many of the functions developed for TCP, including flow control and packet loss recovery functions. In addition, it also supports transport layer multihoming and multistreaming In this paper, we study the impact of multi-homing on the performance of SCTP. We first compare performance of single-homed SCTP. multi-homed SCTP, TCP Reno and TCP SACK. We, then describe potential flaw in the current SCTP retransmission policy, when SCTP host is multihomed. Our Results show that SCTP performs better than TCP Reno and TCP SACK due to several changes from TCP in its congestion control mechanism. In particular. multi-homed SCTP shows the best result among the compared schemes. Through experimentation for multi-homed SCTP, we found that the current SCTP retransmission policy nay deteriorate the perfomance when the retransmission path it worse than the original path. Therefore, the condition of retransmission path is a very important factor In SCTP performance and a proper mechanism would be required to measure the condition of the retransmission path.

• The KIPS Transactions:PartC
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• v.14C no.2
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• pp.163-170
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• 2007

The next generation communication environment consists of various wireless access networks with distinct features that are configured as an overlay topology. In the network environments, the frequency of hand overs should be minimized and the error propagation should be solved in order to provide high-quality multimedia services to mobile users. Therefore, we propose an performance enhancement approach, based on mSCTP, that provides high quality multimedia services to mobile users by ameliorating the error propagation problem. We utilizes the following four functions: 1) the separation of transmission paths according to the types of frames. 2) retransmission strategy to minimize the loss rate of frames, 3) Foced vertical handover execution by utilizing bicasting, 4) using the stability period in order to reduce the effect of the ping pong phenomenon. The simulation results show that the proposed approach provides seamless multimedia service to mobile users by achieving error resilience.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.49
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• pp.3-41
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• 2011

In this article, the author have studied on main revisions and some recommendations of the Incoterms(R) 2010. Main revisions are as belows. 1. Two new Incoterms rules -DAT and DAP- have replaced the Incoterms 2000 rules DAF, DES, DEQ and DDU. 2. New classification of the Incoterms(R) 2010 are adopted. First class is Rules for any mode or modes of transport(EXW, FCA, CPT, CIP, DAT, DAP and DDP belong to this class.) and second class is rules for sea and inland waterway transport(FAS, FOB, CFR and CIF belong to this class.). 3. Incoterms(R) 2010 rules formally recognizes that they are available for application to both international and domestic sale contracts. 4. The Guidance Notes and Introduction are not part of the actual Incoterms(R) 2010 rules. 5. Under the FOB, CFR and CIF, all mention of the ship's rail as the point of delivery has been omitted in preference for the goods being delivered when they are "on board" the vessel. 6. Incoterms(R) 2010 rules include the obligation to 'procure goods shipped' as an alternative to the obligation to ship goods in the relevant Incoterms rules. 7. Incoterms(R) 2010 rules give electronic means of communication the same effect as paper communication. 8. Incoterms(R) 2010 rules have allocated obligations between the buyer and seller to obtain or to render assistance in obtaining security-related clearances. such as chain-of custody information. Some recommendations are as belows. 1. The parties must incorporate the Incoterms(R) 2010 rules into their contract of sale. 2. The parties must choose the appropriate Incoterms(R) 2010 rules. 3. Specify the place or port as precisely as possible in their contract of sale. 4. Remember that Incoterms(R) 2010 rules do not give the parties a complete contract of sale. 5. Incoterms(R) 2010 rules do not prohibit alteration of Incoterms rule, but there are dangers in so doings. In order to avoid any unwelcome surprises, the parties would need to make the intended effect of such alterations extremely clear in their contract.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.5
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• pp.341-346
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• 2017

Knowing the mean free paths (MFPs) of thermal phonons is an essential step in performing heat transfer analysis for nanomaterials, and in determining the optimum design for tailoring the heat transfer characteristics of nanomaterials. In this study, we present a method that can be used to calculate accurately the phonon MFP spectra of nanostructures based on simple phonon kinetic theory. Here, the kinetic theory may be employed by extracting only the diffusive-transport part of the phonon spectrum (i.e., the MFPs are less than a thermal length). By considering phonon dispersion and polarization effects, the phonon MFP distributions of silicon at room temperature are calculated from phonon transport properties and the spectral MFP. Our results are validated by comparison with those of the first principle and MFP spectroscopy data.

• Environmental Analysis Health and Toxicology
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• v.19 no.2
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• pp.191-200
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• 2004

Zinc (Zn) is an essential element in biological process, however inadequate Zn status in general population have been recognized. To update the knowledge for Zn-cadmium (Cd) interaction, we studied the intestinal uptake and transport, and the expression of metal transporter proteins (divalent metal transporter 1, DMT1 ; metal transporter protein 1, MTP1 ; zinc transporter 1, ZnTl ; metallothionein 1 , MT1) in duodenum after Cd exposure using Zn deficient animal model. Rats were led Zn deficient (ZnD, 0.5-1.0 mgZn/kg) or Zn supplemented (ZnS, 50mg Zn/kg) diet for 4 weeks, and followed single administration of $^{109}$ CdCl$_2$orally. The body Zn flatus and tissue Cd concentration were determined at 24 hrs after Cd administration. Total body burden of Cd and Cd absorption index (AI, %) were estimated based on the tissue Cd analyzed. DMT1, MTP1, ZnTl and MT1 mRNA were analyzed by using RT-PCR method. Feeding of Zn deficient diet for 4 weeks produced a reduced body weight gain and a depletion of body Zn. Tissue Cd concentration, body burden of Cd and Cd absorption index were higher in the ZnD diet fed rats than the ZnS diet red rats. Especially, Cd concentration in the small intestine (duodenum, jejunum and ileum) and the colon of FeD diet fed rats were higher markedly than in the FeS diet group. The expression levels of DMT1, MTP1 and ZnT1 mRNA in FeD diet fed rats were similar to the FeS diet. The level of MT1 mRNA expression was significantly lower in the FeD than the FeS diet fed rats. Taken together, theses results indicate that Zn deficiency in diet induce an increased intestinal absorption and tissue retention of Cd, and down -regulate the MT1 expression in the intestine which might be play a part of role in Cd absorption and transport in mammalian. These findings suggest that deficiency of essential metal could be enhanced the toxicity of toxic, non-esstial metals through the metal-metal interaction.

• Korean Journal of Microbiology
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• v.23 no.1
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• pp.9-12
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• 1985

As a part of the host cell development for a amplified recombinant trp operon, $aroP^-$ mutation was introduced in a E. coli host strain. $aroP^-$ mutation was induced by transposon Tn10 and transduced into the E. coli host cell by bacteriophage P1Kc. The effect of $aroP^-$ mutation on the excretion of tryptophan in E. coli $trpR^{-ts}/ColE_1 -trp^+$ cells was investigated. Mutant lacking the general aromatic transport system was resistant to ${\beta}-2-thienylalanine\;(2{\times}10^{-4}\;M)$, p-fluorophenylalanine $(2{\times}10^{-4}M)$, or 5-methyltryptophan $(2{\times}10^{-4}\;M.)[^3H]-tryptophan$ uptake of the $aroP^-$ mutant strain was reduced considerably as compared with $aroP^+$ counterpart. The rate of $[^3H]-tryptophan$ uptake of the $aroP^-$ mutant strain treated with $NaN_3(3{\times}10^{-2}\;M)$ was much less affected than that of $aroP^+$ counterpart. The $aroP^-$ transductants increased the tryptophan excretion from E. coli $trpR^{-ts}/ColE_1 -trp^+$ four times more than $aroP^+$ counterpart.