• Journal of Navigation and Port Research
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• v.41 no.3
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• pp.127-136
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• 2017

The aim of this study is using DEA-CCR, BCC, and Malmquist analysis to determine the efficiency and productivity of Korean automobile ports. We analyzed eight Korean automobile port terminals, using the number of workers and size of ports as input variables and the number of processed car as output variables. An efficiency analysis of the eight automobile port terminals for the four-year span from 2013 to 2016 revealed efficiency levels of 1 for the CCR, BCC, and the scales for Ulsan port and the Gwangyang port terminal, indicating efficient operation of the terminals. As a result of benchmarking analysis, Gunsan port 1, 2 terminal, Incheon port, Pyeongtaek Dangjin 2 terminal should benchmark Busan Port and Ulsan Port. Conversely, Malmquist analysis showed a slight increase in the production volume from 2013 to 2015, but a decline to 1 or less from 2015 to 2016. In the case of TECI the technology was confirmed as effective at 1 or more from 2014 to 2015. The TCI value was 0.87 for the period from 2015 to 2016. During this period, the TCI index of all terminals was less than 1.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.373-376
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• 2003

This paper presents a new, three-dimensional round-robin scheduler that provides high throughput and fair across in an advanced input-queued packet switch using shared input buffers. We consider an architecture in which each input port group shares a common buffer and maintains a separate queue for each output, which is ratted the distributed common input buffer switch. In an NxN switch, our scheduler determines which queue in the total MxN input queues is served during each time slot where M is the number of common buffers. We suppose that each common buffer has K input ports and K output ports, and manages N output queues. The 3DRR scheduler determines MxK queues in every K(M) cycle when $K\geq$M (K$\leq$M), and provides massively parallel processing for the applications of high-speed switches with a large number of ports. The 3-DRR scheduler can be implemented using duplicated simple logic components allowing very high-speed implementation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.12A
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• pp.1136-1146
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• 2005

In this paper, the radiative electric field intensity due to the communication signal and conductive noise is calculated in overhead medium voltage power lines for power line communication. The input impedance is calculated by means of 2 port equivalent model of medium voltage power line network and basic transmission line theory. And then, currents is calculated by calculated input impedance and finally, the emissive electric field is calculated. The input impedance appears like a standing wave form with a fixed cycle because high reflection at the input terminal due to the characteristic impedance of medium voltage power line is very large. A calculated current and radiative electric field also appears like this form. From the measurement results, the measured results are very similar to the calculated results.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.5
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• pp.445-453
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• 2020

The use of tugboats for the safe berthing/unberthing of ships is the most crucial factor in the safe and efficient operation of the harbor. However, the adequate number and size of tugboats that should be held based on the characteristics of the port have not been investigated in detail, which causes disputes between involved parties. Therefore, the suitable number of tugboats and the ratio of the tugboat horsepower were determined in this study using simulation techniques, with focus on Ulsan Port. First, the ship and tugboat-operating models were designed for simulation application. Next, the input variables defined in the model design were standardized in an inputtable form using ARENA software. In addition, the arrival and division process of the ship was designed and simulated as an ARENA model. Finally, the simulation results for six scenarios showed that an effective tugboat operation could be achieved when 42 tugboats were held at Ulsan Port.

• Journal of Satellite, Information and Communications
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• v.5 no.2
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• pp.25-28
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• 2010

The need for multiband RF front-end in modern communication system is growing rapidly. For example, satellite system always uses a complex arrangement of frequency plans and consequently needs filters for each communication channel and it will be ideal to have a single filter module that does jobs of all those channel filters to reduce the size and payload of the system. In this paper, a new method to transform four-port self-feedback balanced dual-band bandpass filter into two-port is proposed. The two-port balanced dual-band bandpass filter which has baluns at the input and output ports and the fundamental frequency at 2.5 GHz and the first harmonic frequency at 5.7 GHz is fabricated and measured. Good agreement between measured and simulated results was achieved.

• Journal of Korea Port Economic Association
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• v.32 no.2
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• pp.25-37
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• 2016

The economy of South Korea has experienced two financial crises: the 1997 Asian financial crisis and the 2008 global financial crisis. These crises had a significant impact on the nation's macro-economic indicators. Furthermore, they had a profound influence on container traffic in container ports in Busan, which is the largest port in South Korea in terms of TEUs handled. However, the impact of the Asian financial crisis on container throughput is not clear. In this study, we assume that the two financial crises are independent and different, and then analyze how each of them impacted container throughput in Busan ports. To perform this analysis, we use an intervention model that is a special type of ARIMA model with input series. Intervention models can be used to model and forecast a response series and to analyze the impact of an intervention or event on the series. This study focuses on the latter case, and our results show that the impacts of the financial crises vary considerably.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.95-98
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• 2002

This paper presents a study on DSP(TMS320F240) controller design for multi-axes transportation system using BLDC servo motor. This BLDC servo motor controller was realized with DSP(Digital Signal Processor) and IPM (Intelligent Power Module). The multi-axes transportation system needs torque, speed, position control of servo motor for variable action. This paper implements those servo control with vector control and space vector modulation technique. As CPU of controller DSP(TMS320F240) is adopted because, it has PWM(Pulse Width Modulation) waveform generator, A/D(Analog to Digital) converter, SPI(Serial Peripheral Interface) port and input/output port etc. The controller of multi-axes transportation system consists of 3-level hierarchy structure that main host PC manages three sub DSP system which transfer downword command and are monitoring the states of end servo controllers. Each sub DSP system operates eight BLDC servo controllers which control BLDC servo motor using DSP and IPM Between host system and middle digital signal processor communicate with RS-422, between main processor and controller communicate with SPI port.

• Journal of Navigation and Port Research
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• v.34 no.9
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• pp.719-726
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• 2010

As the competition among the container terminals in Korea has become increasingly fierce, every terminal is striving to increase its investments constantly and lower its operational costs in order to maintain the competitive edge and provide satisfactory services to terminal users. The unreasoning behavior, however, has induced that substantial waste and inefficiency exists in container terminal production. Therefore, it is of great importance for the terminal to know whether it has fully used its existing infrastructures and that output has been maximized given the input. From this perspective, data envelopment analysis (DEA) provides a more appropriate benchmark. This study applies three models of DEA to acquire a variety of analytical results about the operational efficiency to the Korean container terminals. According to efficiency value analysis, this study first finds the reason of inefficiency. It is followed by identification of the potential areas of improvement for inefficient terminals by applying slack variable method and giving the projection results. Finally, return to scale approach is used to assess whether each terminal is in a state of increasing, decreasing, or constant return to scale. The results of this study can provide terminal managers with insight into resource allocation and optimization of the operating performance.

• Journal of the Institute of Convergence Signal Processing
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• v.15 no.4
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• pp.169-175
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• 2014

NG-SDH system is connected with networks throughout optical fibers. Network synchronization controller is a necessary for the data synchronization in each optical transmission system. In this paper, we have design and implementation the network synchronization controller using SOPC(system on a programmable chip) design technic. For this network synchronization controller we use FPGA in Altera. FPGA includes 32bit CPU, DPRAM(dual port ram), digital input/output port, transmitter and receiver framer, phase difference detector. We also confirm that designed network synchronization controller satisfies the ITU-T G.813 timing requirements.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.205-209
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• 2001

In this paper, we designed power divider that using cellular and PCS band as 2-way device, because each port of designed power divider have reversion that is used to divide the power or compose the power in case of the 2 way, if input port of characteristic impedance with 50$\Omega$ is loading the power then size and phase of power appear on two output port being shared to two parts equally. Usually, divider have division effect of 3dB, but divider have insertion loss when designed in this paper, we have the purpose to design that have good isolation and design that equal insertion loss with minimum insertion loss in the broadband.