• Journal of Navigation and Port Research
• /
• v.28 no.6
• /
• pp.497-501
• /
• 2004

In this paper, it is presented a level sensor for measuring a level of the contents of cargo tank using frequency modulated continuous wave(FMCW). The frequency range is 10∼11 GHz, the radar cross section(RCS) of test target is $0.8\textrm{m}^2$ of metal plate. The experiment is performed in laboratory and open ground, the sweep time of the signal is 100 ms, the pyramidal horn antenna of about 22 dBi gain is used, and input power of antenna is about 8 dBm The beat frequency according to the target moving to 40 m is measured. There is a good agreement between measured and calculated results. But the resolution of the FMCW radar is measured about 10 cm due to nonlinear of voltage controlled oscillator(VCO).

• The Transactions of the Korean Institute of Power Electronics
• /
• v.18 no.6
• /
• pp.530-539
• /
• 2013

In large vessels, proper water level must be maintained with a balance for right and left equilibrium by absorbing or draining sea water in ballast water tank. However, this ship's ballast-water can be drained marine organisms to local sea area by world trade and this can be a source of ecological disturb. In order to solve these problems, marine organisms must be removed in accordance with the international covenant for the emission of microorganisms. By this reason, the seawater electrolysis rectifier of low-voltage high-current rectifiers with excellent ability for microbial treatment is required. In this paper, PSFB converter will be discussed for the seawater electrolysis rectifier. Furthermore, a new output control method with the power limit operation under the limited maximum voltage condition is proposed for this rectifier. The simulation for the proposed current control method for PSFB Converter is shown using MATLAB/SIMULINK. Finally the usefulness of the proposed control method is presented by the experimental results.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.10 no.2
• /
• pp.63-70
• /
• 1996

In this paper, we propose the low sldelobe digital doppler filter bank design algorithm which is practically applicable to coherent radar equipment in complex air-defense system. Using the proposed algorithm, we can obtain a digital doppler filter bank of lower peak sidelobe level and higher clutter suppression capability. In this method, it is possible to achieve higher target-detectability without loss of Target SNR. The proposed algorithms are verified by simulations and experiments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 1999.05a
• /
• pp.163-167
• /
• 1999

The relational data model can't be applied to CAD/CAM, CE, and CIM since it can't support the semantic model concept such as complex object, random data definition, manipulation, version control, generalization, aggregation and so on. In this paper, the IPCS(Integrated Production Control System) for hand-rail of ship is parted into several module according to process function. further more, the object oriented data model is designed with UML(Unified Modeling Language). UML is the object oriented design methodology of industrial standard that combines the Booch's methodology, the Rumbaugh's On(Object Modeling Technique), and the Jacobson's OOSE(Object-Oriented Software Engineering) methodology. The efficient management is expected with object-oriented data model construction, since this developed system can achieve efficient process control, system maintenance, repair and extension.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2004.04a
• /
• pp.83-88
• /
• 2004

Recently, High Tensile Steel is adapt to thin plate on the steel structure and marine structure is used widely. It is possible for buckling happens great. Specially, Initial deflection of ship structure happens in place absence necessarily by heat processing of welding or cutting etc. This Initial Deflection is exerted negative impact when thin plate absence complicated nonlinear behaviour accompanied secondary buckling. As a result, must idealize initial deflection that occurrence is possible to endow stability and accuracy in the hull structure or marine structure and reflect in early structure design considering secondary buckling. Longi direction of compressive load interacts and analyzed finite element series analysis that apply various kinds initial deflection shape measured actually on occasion that is arranged simply supported condition in this research. Applied ANSYS (elasto-plasticity large deformation finite element method) to be mediocrity finite element program for analysis method and analysis control used in Newton-Raphson method ＆ Arc-length method.

• Journal of Navigation and Port Research
• /
• v.34 no.8
• /
• pp.629-634
• /
• 2010

Mathematical model of maneuvering motion for a Mobile Harbor is established and versatile applications to the special situations of maneuvering are attempted. The Mobile Harbor in this research has twin Azipod thruster and twin bow thruster. In order to predict the maneuverability of Mobile Harbor, a mathematical model was developed on the basis of MMG model, and some model test results were adopted for the simulation of Mobile Harbor. As a result, the turning motions of the Mobile Harbor were successfully calculated. and the optimal berthing system was completed.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.12
• /
• pp.2355-2362
• /
• 2016

Seg fog removal is an important issue concerned by both computer vision and image processing. Sea fog or haze removal is widely used in lots of fields, such as automatic control system, CCTV, and image recognition. Color image dehazing techniques have been extensively studied, and expecially the dark channel prior(DCP) technique has been widely used. This paper propose a fast and efficient image prior - dark channel prior to remove seg-fog from a single digital image based on the GPU. We implement the basic parallel program and then optimize it to obtain performance acceleration with more than 250 times. While paralleling and the optimizing the algorithm, we improve some parts of the original serial program or basic parallel program according to the characteristics of several steps. The proposed GPU programming algorithm and implementation results may be used with advantages as pre-processing in many systems, such as safe navigation for ship, topographical survey, intelligent vehicles, etc.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.11 no.1
• /
• pp.23-28
• /
• 2016

In this paper, a Multi-Band Ku-band down converter was designed for reception of multi-band digital satellite broadcasting. The Multi-band low-nose down converter was designed to form four local oscillator frequencies (9.75, 10, 10.75 and 11.3GHz) representing a low phase noise due to VCO-PLL with respect to input signals of 10.7 to 12.75GHz and 3-stage low noise amplifier circuit by broadband noise matching, and to select an one band of intermediate frequency (IF) channels by digital control. The developed low-noise downconverter exhibited the full conversion gain of 64dB, and the noise figure of low-noise amplifier was 0.7dB, the P1dB of output signal 15dBm, and the phase noise -73dBc@100Hz at the band 1 carrier frequency of 9.75GHz. The low noise block downconverter (LNB) for receiving four-band digital satellite broadcasting designed in this paper can be used for satellite broadcasting of vessels navigating international waters.

• Composites Research
• /
• v.31 no.5
• /
• pp.227-237
• /
• 2018

In this paper, the design application for the lightweight and insulation of the manipulator of the mobile welding robot for the closed/narrow space is presented. A variety of robotic platforms have been developed for weld-worker using a welding robot outside a workpiece for welding work in a complex and narrow space such as a ship or an offshore plant. Normally, The development process of robots consists of machine development, electronic device development, control algorithm development and integration verification considering application environment and requirements. In order to develop the robustness of the welding robot, the lightweight design of the robot manipulator considering the environmental conditions was performed in the basic design of the robot platform. Also, The results of the robot selection and validation, analysis and testing for the insulation performance and cooling performance and the results of the research are shown.

• Journal of Power System Engineering
• /
• v.10 no.2
• /
• pp.104-110
• /
• 2006

Corrosion has been around for all of recorded history. Cathodic protection is the electrical solution to the corrosion problem. Corrosion is not exactly a new topic. It has been around since the beginning of time. Corrosion is simply the loss of material resulting from current leaving a metal, following through a medium, and returning to the metal at a different point. Corrosion takes many forms and has various names, such as oxidation, rust, chemical, and bacteria action. Regardless of the agent, all corrosion is the result of electrical current flow. Various methods are used to treat corrosion or to try to prevent ti. Some of these include chemical treatment. coatings, and electrical current. Especially, proper impressed current can stop corrosive action on the protected surface. In this article, we introduce the Impressed Current Cathodic Protection (ICCP) Control and monitoring system developed by ourselves. The ICCP system is composed of a power supply, anode, reference electrode and controller. The main issue is to control the current flow on the desired value such that it is possible to force a metal to be more negative(cathodic) than the natural state. From the this process, we can achieve the cathodic protection. Of course, in the developed system, the necessary functions are possessed, such as remote control, monitoring of system fault detection etc. Some experimental results show the system performance and usefulness.