• Journal of Korean Port Research
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• v.9 no.1
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• pp.45-56
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• 1995

Investigation of the physical behavior of dredged material disposal in coastal water includes estimations of water column concentration in the receiving water, exposure time, the initial deposition pattern as well as thickness of material at the dumping fields near the estuary area. Calculation based on vertical setting and horizontal advection of single particles ignore the effects of bulk properties of the disposed material, vertical and horizontal diffusion, and material dilution due to the entrainment of ambient water during descent. This paper focuses on the spatial and temporal changes in the dumping fields for the water column and bottom at a hypothetically confined coastal water, where the ambient time-invariant velocity and density profiles are applied, within the initial time period following the instantaneous release of the dredged material. This model accounts the behavior of material after release divided into three phases: convective descent, dynamic collapse and long-term passive dispersion

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.1165-1168
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• 1998

This paper describes a 72-word by 32-bit 2-read/1-write multi-port register file, which is suitable for 32-bit RISC/DSP microprocessors. To minimize area and achieve high speed, advanced single-ended sense amplifiers are used. Each part of circuit is optimized at transistor level. The verification of functionality and timing is performed using HSPICE simulations. After modeling and validating the circuit at transistor level, it was laid out in a 0.6um 1-poly 3-metal layer CMOS technology. The simulation results show maximum operating frequency is 179MHz in worst case conditions. It contains 27,326 transistors and the size is 3.02mm by 2.20mm.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.5
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• pp.97-103
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• 1997

Effects of fuel injection timing on the lean misfire limit of a sequential MPI SI engine has been investigated. To investigate the interaction of injection timing and intake flow characteristics, so called axial stratification phenomena, 4 kinds of different intake swirl port of the same combustion chamber geometry have been teated in a single cylinder engine test bench. And 2 kinds of fuel, gasoline and compressed natural gas(CNG), were used to see the effect of liquid fuel vaporization. Result shows that combination of port swirl and injection timing governs the lean misfire limit and lean misfire limit envelopes remain almost the same for a given ratio regardless of engine speed. It is also found that two phase flow has some effects on lean misfire limit.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.3
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• pp.3-7
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• 2010

As the distance between signal lines in memories of high density ICs like SoCs decreases rapidly, failure occurs more frequently and effective memory test techniques are needed. In this paper, a new SRAM structure is proposed to decrease test complexity and test time for embedded DRAMs. In the presented technique, because memory test can be handled as a single port testing and read-write operation is possible at dual port without high complexity, test time can be much reduced.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.10 no.3
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• pp.64-70
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• 1996

In this paper, we designed a low cost data logger system using single chip microcontroller. It detects the normal and abnormal current in distribution system. A sampled analog signals are stored on RAM card(4Mbit) after digitalized by internal A/D converter. Stored data can be transmitted to the personal computer either by internal serial communication port or by external parallel communication port. The transmitted data are analyzed and displayed on personal computer.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.11a
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• pp.101-103
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• 2000

Research for the synthesis of high-temperature polymers by the photochemical method has been carrying out. The use of cheap and available compounds (viz. benzene, its alkyl, aryl and halogen substitutes, furan and maleic anhydride) subject to ultra violet irradiation resulted in a single stage quantitative yield of about 40 new polymers: polyimide films, enamel insulation, molding materials. At present experimental & industrial lots of wire have been produced. Polymer insulation possesses temperature exploitation range (from -l00$^{\circ}C$ to +300$^{\circ}C$ ) without significant changing of properties. As a result, new polyimide lacquers for production of a wide number of technical articles, such as polyimide films, fibres, enamel-wires, press-materials have been synthesized. An application field of the polyimides in membrane technology, printing plate and optic electronics manufactures has been outlined.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.11a
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• pp.33.1-35
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• 2000

Na-K-Nb system showed a number of ferroelectric phases in bulk ceramic. [001]-axis oriented single-phase $Na_{0.5}/K_{0.5}NbO_3$(NKN) thin film have been grown on $LaA1O_3$substrates using KrF excimer laser. X-ray diffraction $\theta$-2$\theta$ scan, rocking curves, and $\varphi$ scan data evidence highly c-axis oriented along the [001] direction.

• Management Science and Financial Engineering
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• v.6 no.2
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• pp.47-67
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• 2000

It is discussed how to assign delivery tasks to automated guided vehicles (AGVs) for multiple container cranes in automated container terminals. The primary goal of dispatching AGVs is to complete all the lading and discharging operations as early as possible, and the secondary goal is to minimize the total travel distance of AGVs. It is assumed that AGVs are not dedicated to a specific container crane but shared among multiple cranes. A mathematical formulation is developed and a heuristic algorithm is suggested to obtain a near optimal solution with a reasonable amount of computational time. The single-cycle and the dual-cycle operations in both the seaside and the landside operations are analyzed. The effects of pooling AGVs for multiple container cranes on the performance of an entire AGV system are also analyze through a numerical experiment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.291-298
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• 2004

The observations of rapid motion of bubbles under water for approximately 50 ms or less in high-magnetic fields of 10 T have been carried out successfully for the first time. The observation system constructed is composed of a high-speed video camera, a telescope, a cryostat with a split-type superconducting magnet, a light source, a mirror and a transparent sample cell. Using this system, the influence of magnetic field on the path and shape of single bubbles of O$_2$ (paramagnetism) and N$_2$ (diamagnetism) has been examined carefully. Experimental values describing the path are in good agreement with theoretical values calculated on the basis of the magneto-Archimedes effect, despite the effect of magnetism on the bubble. However, no effect of magnetism on the shape of the bubble is observed. In addition, the influence of magnetic field on drag coefficient of the bubble is discussed.

• Journal of electromagnetic engineering and science
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• v.13 no.3
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• pp.173-177
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• 2013

This paper presents a new method for analyzing the maximum efficiency of a wireless power transfer (WPT) system with multiple n resonators. The method is based on ABCD matrices and allows transformation of the WPT system with multiple n resonators into a single two-port network system. The general maximum efficiency equation of a WPT system with multiple n resonators is derived using the ABCD matrix. Use of this equation allows placement of the relay resonators for maximum efficiency even though they are asymmetrical. The general maximum efficiency equation and the method of the optimum placement are verified by a full wave simulation. The results show that the method is useful for the analysis of a WPT system with relay resonators.