• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.10a
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• pp.40-41
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• 2010

This study is on the spatial composition of accommodation area in accommodation barge. Accommodation barge used as accommodation facility for offshore plants can be classified into Accommodation Work Barge, Accommodation Pipe Lay Barge and Multi-purpose Accommodation Barge. We study on the spatial composition of accommodation area in Accommodation Work Barge, most frequently used, through analyzing G.A drawings of the barges. The spatial composition.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.9
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• pp.145-154
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• 2012

This paper proves that multi-port junction-based direct receivers (MPDRs) can regenerate I- and Q-channel signals accurately by using conventional I/Q mismatch compensation. This proof enables MPDRs to be integrated into existing RFIC based systems without additional digital signal processing. This paper analyzes the relationship between accuracy of I/Q regeneration parameters and degree of I/Q mismatch, and shows that the estimation results and the simulation results are almost the same.

• Journal of Navigation and Port Research
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• v.40 no.5
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• pp.271-278
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• 2016

Localized atmospheric conditions between multi-reference stations can bring the tropospheric delay irregularity that becomes an error terms affecting positioning accuracy in network RTK environment. Imbalanced network error can affect the network solutions and it can corrupt the entire network solution and degrade the correction accuracy. If an anomaly could be detected before the correction message was generated, it is possible to eliminate the anomalous satellite that can cause degradation of the network solution during the tropospheric delay anomaly. An atmospheric grid that consists of four meteorological stations was used to detect an inhomogeneous weather conditions and tropospheric anomaly applied AWSs (automatic weather stations) meteorological data. The threshold of anomaly detection algorithm was determined based on the statistical weather data of AWSs for 5 years in an atmospheric grid. From the analytic results of anomaly detection algorithm it showed that the proposed algorithm can detect an anomalous satellite with an anomaly flag generation caused tropospheric delay anomaly during localized atmospheric conditions between stations. It was shown that the different precipitation condition between stations is the main factor affecting tropospheric anomalies.

• Journal of the Korean Geotechnical Society
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• v.18 no.4
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• pp.55-64
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• 2002

In the present study, in order to apply a cyclic viscoelastic-viscoplastic constitutive model to multi-layered ground conditions during large earthquake, the numerical simulations of the 1995 Hyogoken Nanbu Earthquake at Port Island, Kobe, Japan, were performed by the seismic response analysis. From the seismic response analysis, it was found that the acceleration calculated from the cyclic elasto-viscoplastic model and cyclic viscoelastic-viscoplastic models for clay was in close agreement with the recorded accelerations at the Port Island down-hole array, and the cyclic elastic-viscoplastic and viscoelastic-viscoplastic constitutive models showed little different behavior characteristics near clay layer. Thus, the propriety of viscoplastic model for clay was convinced. Therefore, it can be concluded that a cyclic viscoelastic-viscoplastic constitutive model can give a good description of the amplification and also it showed accurate damping characteristics of clay during large event which induces plastic deformation in large strain range.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.280-283
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• 2000

Users of computer interfaced with the LAN use the same printer with time sharing. Alternatively, Hey use the multi-user printer interface to print in the office which can't have LAN system due to the great expenses. Otherwise they have to connect directly moving the printer to computer. In this papaer, we present a new printer interface equipment which can interface a printer and multi computers through wireless using the radio frequency of about 430MHz. The tranceivers of the equipment consist of two part: one part is installed in parallel port of computer and other part is installed in Centronix port of printer. Their maximum data rate is 9600bps and the communication area is about 50 meters in best case.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.1
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• pp.94-101
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• 2014

We studied to investigate the erythema reduction effects generated by Gagam-Jawoonaek(GJ) application(appl.) after UV exposure. Twenty women in their twenties to fifties with no skin diseases were recruited. We exposed UV as a 6 subsites on the left upper arm of subjects using multi-port solar simulator. After setting Gagam-Jawoonaek(GJ) application(appl.) subsites and non-appl. subsites, we measured erythema degrees($a^*$ values) of the subsites using spectrophotometer. We measured $a^*$ values four times(before UV exposure, before application of GJ, twenty-four and forty-eight hours after first application of GJ). We analyzed data using student's t-test. After UV exposure, $a^*$ values on the left upper arm increased. Twenty-four hours after first GJ treat., the changes of $a^*$ value on GJ treat. subsites($1.22{\pm}0.13AU$) were bigger than GJ non-treat. subsites($1.04{\pm}0.12AU$), but there was no statistically significance. Forty-eight hours after first GJ treat., the changes of $a^*$ value on GJ treat. subsites($1.95{\pm}0.11AU$) were bigger than GJ non-treat. subsites($1.58{\pm}0.13AU$), a statistically significance. Gagam-Jawoonaek could decrease erythema by UV exposure.

• Journal of Navigation and Port Research
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• v.42 no.2
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• pp.87-96
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• 2018

A trajectory control system plays an important role in controlling motions of marine vehicle when a series of way points or a path is given. In this paper, a sliding mode control (SMC)-based trajectory tracking controller for marine vehicles is presented. A small-sized unmanned ship is considered as a control object. Both speed and heading angle of a ship should be controlled for tracking control. The common point of related researches was to separate ship's speed and heading angle in control methods. In this research, a new control law from a general sliding mode theory that can be applied to MIMO (multi input multi output) system is derived and both speed and heading angle of a ship can be controlled simultaneously. The propulsion force and rudder force are also applied in modeling stage to achieve accurate simulation. Disturbance induced by wind is also tackled in the dynamics considering robustness of the proposed control scheme. In the simulation, we employed a way-point method to generate ship's trajectory and applied the proposed control scheme to ship's trajectory tracking control. Our results confirmed that the tracking error was converged to zero, thus demonstrating the effectiveness of the proposed method.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.1
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• pp.53-59
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• 2002

In this paper, we present design results for an orthomode transducer(OMT) to be used in multi-band antenna feeds. The OMT is realized in the form of a tapered square waveguide, where 18-20 GHz ports are placed in the taper region normal to the waveguide axis, while 30-45 GHz ports are placed in line with the waveguide axis. The reflection coefficient of each port is designed to be less than 20 dB, while the isolation between ports are greater than 15 dB. Thin septa are placed in side ports to reduce the effect of side ports on the return loss of the in-line port. The commercial software HFSS？ is used to design the whole structure.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.211-215
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• 2006

In this paper, design and applications of a generalized, versatile and customizable IF signal generator that can model the modernized GPS and Galileo signal is given. It generates IF sampled data that can be directly used by a software receiver. Entire constellation of satellites which is independent of satellite-user geometry is easily determined using a real or simulated ephemeris data. Since the IF center frequency, sampling frequency and quantization bit number are user location dependent parameters, their effects are also considered in IF signal generator. The generalized IF signal generator will be very well suited for the development phase of a software receiver due to its versatility. The full access to the sampling frequency, front-end filter definition and ADC parameters also offers a great opportunity for cost-effective analysis of tracking loops and error mitigation techniques at the receiver level. Interference sources can be easily added to the generator to simulate specific environments. This software IF signal generator can also be used to feed a multi-frequency multi-system software receiver for the prototyping of a combined GPS/Galileo receiver. The test result using the generated signals and a real software receiver shows the effectiveness of the implemented IF signal generator.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.371-376
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• 2006

Recently the container volume in the global trade is steadily increasing. In an effort to cope with this trend, major ports of the world are stepping up the introduction of high-tech equipments, trying to establish a highly efficient information system, and improving the internal work processes of their container terminals. For speedy and effective cargo handling, they are making every effort in the diverse fields. The purpose of this study aims at developing an intelligent multi-agent system for the gate work of a container terminal, which is the place of authority transfer in a container terminal. The agent system suggested in this study has made a comparison between COPINO information by TOS (Terminal Operating System) and information on containers and trucks recognized at the gate passage, checking up their efficiency, and performing the function of controlling outside truck's input-output. Also, based on the records of outside truck's gate passage, some gates can be operated flexibly, consequently enhancing the efficiency of the gate function. The results of job performance will immediately be notified to the customers and terminal managers, thus helping them make decisions speedily.