• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.4795-4802
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• 2010

In order to solve the traffic problem in jeju, we must reduce demand for car travel. In addition, demand for passenger travel by public transport policy is needed for conversion. And to improve the quality of public transport services are desperately needed. The purpose of this study, personal characteristics of the trip traveler and the relationship between transportation choice, and personal effectiveness as a factor in travel costs and travel time on the impact of transportation choices will investigate. Restructure its public transportation routes, when to switch to buses to car traffic on the data as a basis for the factors that may be. In addition to improving the quality of public transport services is expected to be able to contribute. To study the performance of the May 2010 survey was conducted. And multinominal logit model were conducted. According to the analysis, People who own homes and families with more than 5 people are likely to use cars. If a prolonged travel time is likely to use buses. However, increasing the cost of travel increases the likelihood that the car is available.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2001-2003
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• 2005

Various organic acid were used in order to prepare new metalorganic deposition solution for high quality $REBa_2Cu_3O_{7-{\delta}}$ (RE=Y, Eu, Gd) films. Prepared fluorine free MO precursor solution was coated on single crystal (001) $LaAlO_3$ (LAO) by dip coating method. Processing parameters such as oxygen partial pressure, water vapor, ramping rate and pyrolysis temperature etc havebeen controlled in order to make high $J_c$ films with a good epitaxial relationship with substrate. 0.5 micron-thick film was obtained by single coating and no crack appeared after calcination. Oxygen partial pressure was varied in the range of $100{\sim}1,000 ppm$ and conversion heat treatment was carried out at the temperature of $725{\sim}765^{\circ}C$. A critical transition temperature $(T_{c0})$ of 90K and a critical transport current density $(J_c)$ of $>0.5MA/cm^2$ (77K and self-field) were demonstrated for the YBCO film on (001) oriented LAO substrates with a thickness of 0.5 micron. $I_c$ was determined by utilizing a transport measurement. SEM and XRD investigations confirmed that films were grown epitaxially onto the LAO single crystal substrate. It is thought that fluorine free new MOD solutionis promising for high quality REBCO films.

• Journal of the Korean Institute of Navigation
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• v.18 no.2
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• pp.91-109
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• 1994

Technological and organisational changes in transport system have introduced new dimension into port system development and inter-port competition. The quality of service now required by the customer is costly and not easily provided by small shipping companies and small ports. It has been suggested that in the future container shipping may be concentrated by space-sharing arrangements or actual mergers into the hands of a few mega-operators with the investment potential to provide total logistics networks. In order to compete effectively, high load factors will be essential and port concentration inevitable. A fa-voured few ports will become the load centres and other ports will assume a secondary feeder role. In this study, three questions are raised and attempts are made to answer them : (a) what is the new role of ports today ; (b) why should ports be engaged in this new role ; and (c) how can ports play this new role. In short, a modern port should be a service centre and a logistic platform for international trade and transport-a third generation port. Ports, in particular, have to make every effort to be competitive in the cost and quality of services and to make the port a transport and distribution service centre. For most ports, this is not an option but a must ; an essential requirement for survival in this win or lose situation. The best way to win is to maintain a close contact with port users, listen to them, discuss with them, help them and satisfy them. That is port marketing. Starting from the findings of port marketing, it is es-sential to work out appropriate development plans and marketing targets and to improve port competitive-ness. As an alternative method, a port competitiveness model is suggested, which may help port managers to make appropriate improvements.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.1
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• pp.68-74
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• 2008

The substrate integrated waveguide (SIW) structure can be approximated as the rectangular waveguide using common dielectric substrate with via-holes. To realize reflection-type resonator, $50-{\omega}$ microstrip line can be used for coupling with the center plane of the cavity. The oscillator is designed to operate at 9.45 GHz using the reflection-type SIW cavity resonator. The phase noise of oscillator shows -98.1dBc/Hz at 100 KHz offset. In experiment, the reflection type SIW cavity resonator improves the loaded quality factor making the low phase noise oscillator possible. Due to the entirely planar structure of this resonator, this technique can also be adequate in oscillator applications for a low cost and low phase noise performance.

• Journal of Korea Water Resources Association
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• v.35 no.3
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• pp.261-274
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• 2002

The purpose of this study was to develop two dimensional contaminant transport numerical model by finite element method. The developed model system was tested for water quality analysis when contaminants from tributaries and sewage treatment Plants flow into the main river. In this study, the model was to perform calibration for reasonable parameter production and verification for reliability and accuracy. And, the proposed model was applied on the downstream of Han river using calibrated parameters. These results represented real con taminant distribution profile along the channel, and produced the good agreement in comparing calculated vague with measured value.

• The Transactions of the Korea Information Processing Society
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• v.4 no.4
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• pp.1059-1075
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• 1997

The transprot layer protocol for distrubuted multimedia applications in high speed network should gurantee the Quality of Serivce(QoS)requested by uwer.,The QoS Parmenters can be divied into two calssifications:those depend on the speed of a network such as bandiwidth,end-to-end transmission delay and throughput;and net- woek independent parameters such as various typed of group communications, retransmission method based on multimeda characteristic,acceptable packet wrror rate and transmission priority.In this proposed protocol,we divided user's QoS into performance redated parmeters and non-performance related parameters.The perform- ance-related paramenters are mapped into ATM traddic paramenters by the Distributed QoS Manger(DQM),the QoS manager,and the non-performance redlted paramenters are supported by the Distributed Multimedia Trans-port protocol(DMTP),a high-performance group transport protocol.Especially,becaues the DMTP is designed with considering the IP protocol,it can be efficiently used as an underlying protocol not onlu in ATM,but also in Ethernet,Token ring and FDDI LAN.

• Journal of the Korean Society for Marine Environment & Energy
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• v.6 no.4
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• pp.67-82
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• 2003

A 2-dimensional hydrodynamic model has been applied to understand water circulation pattern in Lake Deacheong. The simulation results have been used in sediment transport modeling. A sediment transport model using a particle tracking method has been developed to simulate sediment transport in the ocean, river and reservoir. The model was applied to estimate transport track of particulate pollutants in the lake. The hydrodynamic model was verified for water level variations and showed good agreements. Through the results we found out that water velocity is less than 5 cnysec for mean yearly flow and more than 120 cnysec at some points for the simulated flood flow. The incoming sediment particles in flood season reached into the Daecheong Dam. But the incoming sediment particles in the mean flow were settled down at riverbed and didn't move into the dam. These results can be used in setting up water quality management plan in the lake.

• Journal of Internet Computing and Services
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• v.10 no.6
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• pp.27-36
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• 2009

PSTN (public switched telephone network) provides voice communication service, whereas IP network provides data oriented service, and we can use IP network for multimedia transport service (e.g. voice over IP service) with economic price. In this paper, we propose RoIP (robot on IP) service scenario, signaling call flow, and implementation to provide home automation and monitoring service for remote site users. In our scheme, we used a extended SIP (session initiation protocol) for signaling protocol between remote site users and home robots. For our bearer transport control, we implemented H.263 video codec over RTP (real-time transport protocol) and additionally DTMF (dual tone multi-frequency) transport for robot actuator control. We implemented our scheme on home robots and experimented with KTF operator network, and it shows good communication quality (average MOS = 9.15) and flexible robot controls.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.515-518
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• 2003

Mathematical models can be used to evaluate the effects of operational alternatives of dam on the downstream aquatic environment. An unsteady, one-dimensional water quality model, CE-QUAL-RIVI was calibrated and validated in Geum river as a sub model for the realtime water management system in the basin. The main usage of the model within the system is to predict the effects of flow regulation by Daecheong Dam on the downstream water quality. The validated model was then used to simulate dynamic water quality changes at several key stations responding to different scenarios of reservoir releases under a hypothetical spill condition. The model showed fairly good performance in the simulation of hydrodynamic and mass transport processes under highly unsteady conditions.

• Water for future
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• v.28 no.1
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• pp.57-70
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• 1995

A water quality model RIV-LAGI for the toxic pollutant transport analysis is developed based on varied flow analysis and one-dimensional Lagrangian method. Applying to the prismatic channel, it shows accurate results compared with the analytical solutions. The model is applied to the Nakdong River to analyze the phenol spill accident, which occurred on March, 1991. The computed results have good agreements with the observed data. The travel times in the reach of Gumi to Mulkeum based on the monthly average and minimum flow are computed. The suggested model can be used to study the impact of the chemical spills and clean-up plans in the Nakdong River.