• Journal of the Korean Society of Marine Environment & Safety
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• v.4 no.2
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• pp.13-24
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• 1998

This study aims at examining the safety of the would-be approach channel of LNG Terminal at Kwangyang Harbour, by utilizing Captains 2000 port-design simulator. Six competent shipmasters or navigators participated in this study. The developed model ship was a 70,200DWT (138,000m3) LNG carrier. The environmental conditions were maximum flood-and-ebb current condition and wind condition. To evaluate the navigational safety, two categories were analyzed, which were measures of vessel's proximity and shiphandler's subjective evaluations. With respect to the effects of the worst environmental conditions on transit safety, it was concluded that the would-be approach channel was safe on basis of the support of four tugs of 3,200hp or more and current speed of 0.5knots or less.

• Journal of Navigation and Port Research
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• v.40 no.1
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• pp.43-50
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• 2016

Amid of the logistics hub center competition is going to intensifying between the world major port, it is essential to pre-occupied the base in the logistics hub world take advantage of advanced technology of logistics equipment than other ports. In existing container terminal, when container moves the terminal use the omnidirectional and directional antenna in order to exchange data information on the basis of 802.11 wireless network system. Case of loading height of exceeding, the blind sport will occur and a limited frequency channel can't help using in the area. A limited frequency channel usage and nested areas happen to use the closed terminal, it has a great influence to operate the terminal working. In this paper, LTE network is configured provided by the specified company ('L' Corp,.Ltd) and terminal data extracted through LBO (Local Breakout) in the cell site which is configured directly with container terminal operation server. Using this method, container terminal yard equipment operate without overlapping arises with uninterrupted data presented for ways to efficiently. I would suggest both the existing wireless AP LAN configuration of container terminal and new LTE system and applied to the real yard operating devices situations. Through these methods presented comparative the existing network traffic with new constructed LTE configuration. I admired to suggest that wireless network LTE introduction is fundamental factors to get rid of the blind spot, the problem of limited frequency channel and overlapping arises. These essential points can be a continual improving terminal services and more efficient terminal operational management.

• Journal of Navigation and Port Research
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• v.28 no.5
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• pp.359-364
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• 2004

When sea going vessel approaches her destination port, marine traffic density is increased, especially, the marine traffic is concentrated in the entrance channel and the fairway in the inner harbour is more narrow. Therefore, special navigational rules for preventing collision at sea is needed in the inner harbour. Hence there are the rules in The Public Order in Open Port Act in Korea But, in the case of conflict of navigational rule concerned, it is possible to be raised a question that which rule shall be applied preferentially. Also, it is necessary to understand the exact meaning of the navigational rules in The Public Order in Open Port Act. Because the misunderstanding of the rule is caused the collision Therefore, this paper aims to discuss the exact meaning of the navigational rule concerned in the view of legal basis and suggest the principles for a proper application of it.

• Journal of Navigation and Port Research
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• v.31 no.1 s.117
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• pp.1-6
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• 2007

The evaluation of safety of simulated maneuvers is frequently analysed by so called goal-line or point of interest in Korea. For the purpose of warning the risk in the proximity measure composed of only the goal-line analysis, this paper utilized Korea Institute of Maritime and Fisheries Technology(KIMFT) which houses a real-time, full-mission shiphandling simulator to examine the goal-line and in-length analyses in the outbound channel of Kwangyang port as an example. It used a 15,000 TEU container ship as a model under environmental conditions of the northwestly 26-knot wind and 2.2-knot ebb current. The result of two analyses showed the probability invading the channel boundary obtained by the goal-line analysis is a little greater than that of the in-length analysis. Therefore it was acknowledged that the proximity measure by the goal-line analysis alone may be followed by some risk. In addition, this paper was to suggest the closest distance to channel boundary from the ship's edge as one of proximity measures, instead of using the ship's deviation from the centerline of channel.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.10a
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• pp.230-239
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• 2006

The depth, width and alignment of fairway that are main port water facilities should be designed considering the various elements including particulars of design ships, weather and sea conditions around fairway and method of ship-handling. However not only the existing Japanese design standard for fairway and also those of other countries do not take into consideration of such kind of elements and no design standard is made by quantitative analysis. In this circumstance the new design standard (Approach Channels, A Guide for Design) depending on classified various elements and quantitative analysis was proposed in 1997 by PIANC and IAPH. But it was proved that calculated values according to this standard were unfounded and had some problems to output the discontinuous value by small difference of calculation condition because the each value fur each element was simply added. And also it is hard to apply this standard to the design of port water facilities in Japan because this [A Guide for Design] is the design standard for long channels in European port. The proposal of more reasonable Japanese standard will be expected by applying the study result of naval architecture and navigation and by the cooperation of ship operators to use fairway, naval architects to built ships and civil engineers to dredge fairway. The concept of a fairway in 'Design standard fur fairway in next generation' is defined as passage for approach channel) and traffic lane designated by light buoys as navigable water for safe navigation. In 'Design standard for fairway in next generation' depth, width and alignment are picked up among many design elements of a fairway. Design method for those elements is shown based on design ships and navigational environments. This standard shows the method of design for each dimension depending on characteristic on design ship and weather and sea condition. On the other hand, in case of existing fairway, it is possible to decide the size of ship and navigation criteria by opposite analysis.

• Journal of Navigation and Port Research
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• v.41 no.4
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• pp.173-180
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• 2017

Underwater communications are degraded as a result of inter symbol interference in multipath channels. Therefore, a channel coding scheme is essential for underwater communications. Packets consist of a PN sequence and a data field, and the uncoded PN sequence is used to estimate the frequency and phase offset using a Doppler and phase estimation algorithm. The estimated frequency and phase offset are fed to a coded data field to compensate for the Doppler and phase offset. The PN sequence is generally utilized to acquire the synchronization information, and the bit error rate of an uncoded PN sequence predicts the performance of the coded data field. To ensure few errors, we resort to powerful BCJR decoding algorithms of convolutional codes with rates of 1/2, 2/3, and 3/4. We use this powerful channel coding algorithm to present an efficient receiver structure based on the relation between the bit error of the uncoded PN sequence and coded data field in computer simulations and lake experiments.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.06a
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• pp.115-155
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• 2000

Nawadays LNG has been beginning to take the place of petroleum as fuel all over the world and VLCC tankers of LNG will take the same sea routes that had been used by VLCC tankers of petroleum in the last pat of he 20th century. The transportation of LNG by a VLCC include more dangerous nature of sea peril than that of petroleum. We already know the dimensions of a disaster a LNG tanker could bring about in the case of the LNG tanker, Yuyo-Maru No. 10 in the Tokyo Bay of Japan in 1974. From the point of safety when we construct a LNG base or LNG pier in the base, the appropriate government authority and constructing company had better take sea pilots or some ships handling experts to participate in a prior consultation of the design of the project. A G/T 100,000 ton LNG base and pier were completed in November of 1996 in Inchon harbour in Korea and LNG VLCC tankers of G/T 100,000 ton class have been entering into the base ever since. This study was started and completed to comply with the requisition of the Sea Pilot Association of Inchon harbour in advance of the opening of the LNG base. As the entrance and exit channels leading to Inchon harbour were constructed in the years of 1930s, it was one of the most pressing works for Inchon sear pilots in 1996 to certify the method of safe passing maneuvering of a G/T 100,000 ton LNG tanker through the Pudo narrow channel prior to commercing actual piloting of the LNG VLCC tanker. The author made some mathematical models computing maneuvering of a vessel changing her course with her control surface through a narrow channel and computed maneuvering of a G/T 100,000 ton LNG tanker and also made maneuvering simulations of the vessel by a desk-top simulator. The results of computations and simulations are well coincided with each other in qualitative aspects to assure safe passing of the LNG VLCC.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.4
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• pp.33-41
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• 2014

This paper presents an effective memory access method for a high-speed data transfer on mobile systems using a direct memory access controller that considers the characteristics of a multi-port memory controller. The direct memory access controller has an integrated channel management function to control multiple direct memory access channels. The channels are physically separated and operate independently from each other. Experimental results show that the proposed direct memory access method improves the transfer performance by up to 72% and 69% on read and write transfer cycles, respectively. The total number of transfer cycles of the proposed method is 63% less than in a commercial method under 4-channel access.

• International Journal of Air-Conditioning and Refrigeration
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• v.7
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• pp.1-10
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• 1999

In this study, a numerical analysis is made on the ice-formation for laminar water flow inside a stenotic tube. The study takes into account the interaction between the laminar flow and the stenotic port in the circular tube. The purpose of the present numerical investigation is to assess the effect of a stenotic shape on the instantaneous shape of the flow passage during freezing upstream/downstream of the stenotic channel. In the solution strategy, the present study is substantially distinguished from the existing works in that the complete set of governing equations in both the solid and liquid regions are resolved. In a channel flow between parallel plates, the agreement between the of predictions and the available experimental data is very good. Numerical analyses are performed for parametric variations of the position and heights of stenotic shape and flow rate. The results show that the stenotic shape has the great effect on the thickness of the solidification layer inside the tube. As the height of a stenosis grows and the length of a stenosis decreases, the ice layer thickness near the stenotic port is thinner, due to backward flow caused by the sudden expansion of a water tunnel. It is found that the flow passage has a slight uniform taper up to the stenotic channel, at which a sudden expansion is observed. It is also shown that the ice layer becomes more fat in accordance with its Reynolds number.

• Journal of Navigation and Port Research
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• v.26 no.5
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• pp.543-548
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• 2002

It has been known that the DCMP(Directionally Constrained Minimization of Power) and the ZF(Zero Forcing) can improve the SINR performance of an array antenna system by using spatial signature of wireless channel. This paper analyzes the performance of DCMP and ZF in multiple scattering environments. To obtain the spatial signature of wireless channel. both DOA(Directional of Arrival) and AS(Angular spread) of the received signals were estimated by using ESPRIT. The performance of the DCMP and the ZF was analyzed theoretically. By computer simulation of SINR performance was evaluated.