• Journal of Navigation and Port Research
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• v.29 no.3 s.99
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• pp.245-250
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• 2005

In this paper, considering PAR of transmitter which is pointed out OFDM system's problem, we designed Coded OFDM (COFDM) system and estimated BER and SNR using PAR reduction method In order to evaluate performance, we compared M-ary PSK (M-ary Phase Shift Keying) with M-ary QAM (M-ary Quadrature Amplitude Modulation). In result, performance of 16-PSK and 16-QAM came to good Moreover, 16-QAM showed better performance of about 2 dB in 10-3 error probability and performance of about 5 dB in Peak power clipping than that of 16-PSK.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.111-116
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• 2004

A fishing gear is an used tool to achieve fishery effectively. Especially, long line is fishery method to confect branch line to fixed space to main line and bind fishhook 1 in branch line end. This paper presents the design and implementation of fishing gear type setting system for fishing gear layout management in the long line work. In this paper, we design overall fishing gear type setting system. For this purpose, the modules such as system user and communication environment setting module, fishing gear type setting module, module of fishing gear shooting model are designed and implemented. For the validity evaluation of this paper, fishing gear type design and shooting process are implemented and tested.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.123-127
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• 2004

The present system of medium and large size ship when that's ship came alongside the pier, are not systemic. The steersman only depend on radio-communication, not visuality. This treatise bridge a gap of current system from development of simulation program The main-server get a distance from ship to peer and ship's direction using longitude and latitude, heading, rate. The steersman of main ship and tug will see all situation with PDA client program. The PDA client program directly display a location information from main-server. And ship's most suitable path be calculated simulation program using database system. This method will induce more detail situation information and the most suitable path when the ship coming alongside the pier.

• Journal of Navigation and Port Research
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• v.29 no.6 s.102
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• pp.555-560
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• 2005

Recently, many control systems are replaced with digital control systems in an effort to optimize the overall performance. In order to operate these systems efficiently, the conventional point-to-point connection method must be changed to the signal exchange via a communication network. This paper investigates the technical feasibility of the crane system using CAN protocol which is a part NMEA 2000 by implementing a network-based control system emulating the crane control system.

• Journal of Navigation and Port Research
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• v.31 no.6
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• pp.463-470
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• 2007

Each on-board equipment providing navigational and engine information has different signals. These signals should be analyze, be transformed to the standard digital form and be transmitted to each client on board through the earlier developed ILU (integrated LAN unit). Therefore this paper was to analyze the signals of each equipment for navigation and engine and was to use the serial technology necessary for the equipment and IDU (information display unit). And this paper was then to develop an SIU (ship's interface unit) and to test it onboard.

• Journal of Navigation and Port Research
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• v.32 no.9
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• pp.705-709
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• 2008

In the sea various methods have been conducted to capture wave energy which include the use of pendulums, pneumatic devices, etc. Floating devices, such as a cavity resonance device take advantages of both the water motion and the wave induced motions of the floating body itself. The wave energy converter is known commercially as the WAGB(Wave Activated Generator Buoy) and is used in some commercially available buoys to power navigation aids such as lights and horns. This wave energy converter consists of a circular flotation body which contains a vertical water column that has free communication with the sea. A theoretical analysis of this power generated by a pneumatic type wave energy converter is performed and the results obtained from the analysis are used for a real wave energy converter buoy. This paper is shown to have an optimum value for which maximum power is obtained at a given resonant wave period Also, the length of the internal water column corresponds to that of the water mass in the water column. If designed properly, wave energy converter can take advantage not only of the cavity resonance, but also qf the heaving motion of the buoy. Finally, simulation is performed with a LabVIEW program and the simulation results are applied to a wave energy simulator for modifying design data for a wave energy converter.

• Journal of the Korean Geophysical Society
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• v.4 no.4
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• pp.239-249
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• 2001

NAT (Network Address Translation) is an IP address modification protocol that translates private IP addresses into authentic Internet addresses. The main features of NAT are to improve network security and to save IP addresses. Generally speaking, in order to perform its functionality. NAT uses the address informaiton in the packet header. Certain application protocols, however, use the information in the packet data as well as the imformation in the packet header to perform end-to-end communication. Therefor, to support these types of application protocols, NAT should be able to perform appropriate translation of protocol information in the packet data. In this thesis, we design and implement a method which translates virtual IP information in the packet data into real IP information by using port proxy server.

• Journal of Convergence Society for SMB
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• v.6 no.2
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• pp.31-36
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• 2016

Sniffing attack is a passive attack which is reassembling packets to collect personal information, bank accounting number, and other important information. Sniffing attack happens in LAN and uses promiscuous mode which is opening filtering by pass all packets in LAN, attackers could catch any packets in LAN, so they can manipulate packets. They are Switch Jamming, Port mirroring, ARP Redirect, and ICMP Redirect attack. To defend these attacks, I proposed to use SSL packet encryption, reconfiguration of switching environment, DNS, and decoy method for defending all kinds of Sniffing attacks.

• International Commerce and Information Review
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• v.9 no.4
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• pp.241-261
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• 2007

9.11 terrors which happen in 2001 in the U.S. recognize importance about national security and Department of Commerce, country safety department, Federal Communication Commission(FCC) etc. are establishing RFID sticking plan in harbor exit and entrance container for this, and it is real condition that is preparing preparation of law and system that establishes harbor peace law(Safe Port Act) on October, 2006 and acts on for U.S. about container load cargo Europe and Asia each countries. These law and system is logistics security that strengthen search for import and export freight and security to main contents. To meet in these circumstance subsequent, this paper is to examine the following three themes. First, examined necessity of logistics security and logistics security strengthening tendency, and second, examined in achievement of logistics business and RFID, and third, presented logistics security process that utilize change of realization about logistics security and RFID's role for logistics security. Through upper investigation, this paper suggested the realization about logistics security raising, logistics security connection system construction by export step, real-time freight chase that use RFID, construction necessity of executive system and development of logistics security equipment required.

• 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.