• The KIPS Transactions:PartC
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• v.10C no.3
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• pp.367-376
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• 2003

This study deals with the DCMST (Delay constrained Capacitated Minimum Spanning Tree) problem applied in the topological design of local networks or finding several communication paths from root node. While the traditional CMST problem has only the traffic capacity constraint served by a port of root node, the DCMST problem has the additional mean delay constraint of network. The DCMST problem consists of finding a set of spanning trees to link end-nodes to the root node satisfying the traffic requirements at end-nodes and the required mean delay of network. The objective function of problem is to minimize the total link cost. This paper presents two-phased heuristic algorithm, which consists of node exchange, and node shift algorithm based on the trade-off criterions, and mean delay algorithm. Actual computational experience and performance analysis show that the proposed algorithm can produce better solution than the existing algorithm for the CMST problem to consider the mean delay constraint in terms of cost.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.12
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• pp.1044-1049
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• 2015

In this paper, isolation enhanced antenna using isolating resonator was proposed. Two loop type antennas were designed to operate at Wi-Fi band(2.4~2.5 GHz), in symmetry to the center, and are closely located to each other. In order to enhance isolation characteristics at Wi-Fi bands, isolating resonator was designed between the two loop type antennas. The proposed isolating resonator is a slot type antenna that enhances isolation with the control of the size, and by adjusting the value of capacitor($C_D$) the resonant frequency of the isolating resonator can easily be adjusted to enhance isolation characteristic at the target frequency.

• The KIPS Transactions:PartD
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• v.13D no.3 s.106
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• pp.445-454
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• 2006

Almost of industrial measuring instruments usually are equipped only with serial communication devices. In order to connect these instruments to internet, we implement an embedded translator. This device has the hardware components composed of one WAN port, two LAN ports, and two UARTs, and functions as a communication translator between serial and internet communication. it also provides web-based monitoring function that is absent from existing serial-to-ethernet converter. The hardware is implemented using the KS8695 network processor which s an ARM922T as processor core. We have installed the boa web server and utilized the CGI function for internet-based remote control, added the IP sharing function which allows the network with private IP addresses to access the internet, and developed a serial-to-ethernet translation program. Finally, we show an application example of the developed translator that remotely monitors the solar energy production system.

• KIISE Transactions on Computing Practices
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• v.20 no.12
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• pp.632-639
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• 2014

In this paper, we propose a PC's self-monitoring system for protecting illegal outflow of important personal files, which are managed in the Windows environment PC. This paper is based on the idea that it should be a read (access) file operation in order to outflow files through the network. To compare the information (name, some content) obtained from all operations of the reading of the 'Windows File System Driver' and captured transmission packets of mini port of 'Windows NDIS (Network Driver Interface Specification) Driver', and, if two pieces of information match, this system will determine the transmission to user. In this paper, tentatively, we developed a function to gather file information about file read operation and developed a function for transmission packet capture. This demonstration implementation showed that the proposed process has validity and the proposed process verified that it does not significantly affect the PC's performance.

• Journal of Korean Port Research
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• v.7 no.2
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• pp.37-60
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• 1993

Because of the rapid growing traffic volumes of cargo, especially between Seoul and Inchon, and lack of investment into transport infrastructure in the past, in Kyong-in area have suffered from the serious traffic congestion in the public-road and the express-way network, But the further expansion of the traffic volume in near future is difficult due to burden of the higher expansion of the traffic volume in near future is difficult due to burden of the higher construction cost. Although the traffic congestion on the Kyung-in railway, is not very serious comparing with the road sector, the shortage of capacity on some main lines becomes emerged as a problem as railway traffic has increased. Unlike these two modes, the water transport, which has been paid relatively less attention for commodity transport in Kyong-in area, has not any constaint in this respect. Han river has been used as a water transport route in Chosun Dynasty which is called Cho-wun. This paper therefore aims to propose the availability of Han river as the alternative water transportation mode, in order to decrease the congestion between Seoul-Inchon by considering the construction of Kyong-in artificial water channel in near future. In this paper, we investigate the availability of Nanji-do as the physical distribution depot connecting with the circulation express way in the national capital distribution depot connecting with the circulation express way in the national capital. We also estimate the traffic volume by using the push-barge carrier (300DWT) in the same channel through the simulation under some assumptions such as ship's turnaround time, speed, etc.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.3
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• pp.264-272
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• 1997

This paper presents the analysis of forced resonance characteristics of electrically small dipole antenna loaded with external element and its application to measuring unknown frequencies. The method of moments with Galerkin's procedure is used to determine the current distribution of the antenna. To derive the determinantal equation of resonance lengths at a given frequency, small antennas with the reactance loaded can be treated as a two-port network. Numerical results show that the forced resonance of the electrically small dipole antenna loaded with reactance can be easily obtained by controlling the reactance for the series resonance as well as for the parallel resonance. It is demonstrated that the forced resonance characteristics can also be applied to the measurement of unknown frequencies.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.10
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• pp.1706-1711
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• 2016

Electromagnetic wave simulation was performed to predict characteristics of manufactured cutoff probe at low temperature magnetized plasma medium. Microwave cutoff probe is designed for research the properties of magnetized inductively coupled plasma. It was shown that the cutoff probe method can safely be used for weakly magnetized high density plasma sources. Cutoff probe system with two port network analyzer has been prepared and applied to measure electron density distributions in large area, 13.56MHz driven weakly magnetized inductively coupled plasma source. The results shown that, the plasma frequency confirmed cut-off characteristics in low temperature plasma. Especially, cut-off characteristics was found at upper hybrid resonance frequency in the environment of the magnetic field. In case of a induced weak magnetic field in inductively coupled plasma, plasma density estimated from the cutoff frequency in the same way at unmagnetized plasma due to nearly same plasma frequency and upper hybrid resonance frequency. The plasma density is increased and uniformity is improved by applying a induced weak magnetic field in inductively coupled plasma.

• Journal of Electrical Engineering and information Science
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• v.2 no.5
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• pp.17-26
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• 1997

Interconnect characterization on a wafer level was performed. Test patterns for single, two-coupled, and triple-coupled lines ere designed by using 0.5$\mu\textrm{m}$ CMOS process. Then interconnect capacitances and resistances were experimentally extracted by using tow port network measurements, Particularly to eliminate parasitic effects, the Y-parameter de-embedding was performed with specially designed de-embedding patterns. Also, for the purpose of comparisons, capacitance matrices were calculated by using the existing CAD model and field-solver-based commercial simulator, METAL and MEDICI. This work experimentally verifies that existing CAD models or parameter extraction may have large deviation from real values. The signal transient simulation with the experimental data and other methodologies such as field-solver-based simulation and existing model was performed. as expected, the significantly affect on the signal delay and crosstalk. The signal delay due to interconnects dominates the sub-micron-based a gate delay (e.g., inverter). Particularly, coupling capacitance deviation is so large (about more than 45% in the worst case) that signal integrity cannot e guaranteed with the existing methodologies. The characterization methodologies of this paper can be very usefully employed for the signal integrity verification or he electrical design rule establishments of IC interconnects in the industry.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2206-2208
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• 2003

LMTT(Linear Motor-based Transfer Technology) is horizontal transfer system in the maritime container terminal for the port automation. The system is modeled PMLSM(Permanent Magnetic Linear Synchronous Motor) that is consists of stator modules on the rail and shuttle car(mover). Because of large variant of movers weight by loading and unloading containers, the difference of each characteristic of stator modules, and a stator module's default etc., LMCS(Linear Motor Conveyance System) is considered as that the system is changed its model suddenly and variously. In this paper, we will introduce the soft-computing method of a multi-step prediction control for LMCS using DR-FNN(Dynamically Constructed Recurrent Fuzzy Neural Network). The proposed control system is used two networks for multi-step prediction. Consequently, the system has an ability to adapt for external disturbance, cogging force, force ripple, and sudden changes of itself.

• Journal of Information Technology Services
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• v.8 no.1
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• pp.193-202
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• 2009

Cloud computing emerges as a new computing paradigm which targets reliable and customizable services. The term builds on decades of research in virtual machine, distributed and parallel computing, utility computing, and more recently networking, web service, and software as a service. In this paper, we provide a seamless connection migration of web services. This is useful for cloud computing environment in which many client terminals have mobility. With the wireless internet facility, those mobile users can move place to place during internet communication. Therefore, we provide solutions to the two major problems in current virtualization based migration: communication failure problems and connection re-establishment. Communication channel flushing by zero window notification helps to resolve the communication failure problems and TCP port inheritance prevents connection re-establishment errors during socket reconstruction. Thus, our web service migration facility is now able to preserve open network connections, and even for server sockets. This is a highly transparent approach, in that we did not Introduce additional messages for channel flushing and did not make any modification to the TCP protocol stack. Experimental results show that the overhead due to connection migration of web services is almost negligible when compared with time to take the conventional web service migration.