The effect of the submerged high speed vessel on the ocean wave is made clear in the point of hydrodynamics view. In connection to the design of high speed ship, the flow analysis is carried out to predict the pressure distribution for drag and lift. The purpose of the research is to help the preliminary design of the economic hull form advancing under the ocean wave by estimating the resistance performance and the wave behaviour. In the present study, more efficient numerical approaches are investigated for the viscous flow analysis around a submerged NACA0012 hydrofoil with the laminar and incompressible fluid. Through the numerical simulation, it is found that the new numerical method becomes more efficient primarily due to the fact that the wave elevation is reasonably developed.
When an automatic course keeping is introduced, as is quite popular in modern navigation, the closed-loop control system consists of autopilot device, power unit, steering gear, ship dynamics, and magnetic or gyrocompass. We derive mathematical models of each element of the automatic steering system. We provide a method of theoretical analysis on the propulsive energy loss related to automatic steering of ships in the open seas, taking account of the on-off(non-linear) characteristics of power unit. Also we paid attention to non-linear element installed in autopilot device, which is normally called weather adjuster. Next we make numerical calculation of the effects of autopilot control constants on the propulsive energy loss for two kinds of ship, a fishing boat and an ore carrier. Realistic sea and wind disturbances are employed in the calculation.
Mathematical morphology skeleton image processing makes many partial skeleton image planes from an original binary image. And the original binary image can be reconstructed without any distortion by summing the first partial skeleton image plane and each dilated partial skeleton image planes using the same structuring element. Especially compression effects of Elias coding to the morphological globally minimal skeleton(GMS) image, is better than that of PCX and Huffman coding. And then this paper proposes mathematical morphological GMS image processing which can be applied to a binary image transmitting for facimile and big size(bigger than 64×64 size) bitmap fonts storing in a memory.
IEC and CISPR have continuously endeavored the measurement method of Immunity Test as international unification, but not established yet. The main reason is that the measurement method and the normalization of threshold to obtain the complicated parameters for Immunity Test are difficult. Thus, the Immunity Test Setups are used differently according to the measured electromagnetic environments. This study developed an Immunity Test System and Algorithm for measurement software suitable for IEC801-3 Regulatons using ready-made amplifier, signal generator, and developes interconnecting interface board interacting with other appratus i.e., RF Switch, Power Meter, Field Sensor and Pre-amp. We are to develope an automated software using Top/Down and OOP(Object Oriented Programming) method.
The development of Korean shipping industry is maybe defined into three development stages-industry fixing stage, industry coordinating stage, industry development stage-. The development of shipping industry has been depended on the geovernment/authority role such as shipping policy, system, law, rules and regulations. In 1983, Korean shipping industry reorganization and coordination by shipping authority have made our shipping industry on the stable condition together with each company's efforts. Today's world economic environment such WTO/UR negotiation results get this government role limited. According to the being reduced government role, each company's competitive advantage power becomes more important. Besides, korean shipping industry is exposed into the entire and bitter world competition. In order to win and prevent the world shipping competition, it is necessary to look out the competitive advantage power of Korean shipping industry. The first purpose of this study is the situation analysis for competitive advantage power of Korean shipping industry. The second is to compare with our shipping policies with foreign ones concerned with ship, cargo, crew, tax and others. But in order to compare with foreign shipping, this study need their shipping statistics data, this study has some limit of the foreign data. This study has been carried on the basis of the following items. 1. Shipping environment, 2. Ships and ship acquirement(shipbuilding/purchasing), 3. Oceangoing cargo and ship's stowage rate, 4. Human factor in shipping-crew, 5. The incomes and costs in finacial statements. We have some conclusions as following through the this study. First, Korean shipping industry environment-competitive disadvantage situation- has changed rapidly due to the shipping market opening, free market entering of foreign shipping. Second, Korean shipping is disadvantageous due to the high tax rate and financing conditions in connection with ship acquirement. In order to improve the competitive advantage power, the shipping tax system and ship financing conditions should be reviewed to profitable for owners. Third, but both world and Korean oceangoing cargoes quantity have been increased annualy, Korean ship's cargo stowage rate is being decreased. This is serious situation but Korean shipping take well use of foreign vessel with hire. It is recommended to take use of owner's vessel and hired ones in the long range view, considering the world shipping management. But the number of crew has been decreased by 2, 000~3, 000 annualy, it is desirable that the long sea-experienced crew have been increased. Almost of owners usauly complain the crew cost is the main obstacles to competitive advantage power. Human factor is the most important firm's asset. All owners should pay attention to this though, and invest the proper budget to training, education, welfare as much as possible. In the long run this effects could be feedback to owners. Fifth, We must improve the financial statements structure, that is, the first step is to increase income, the second is to decrease cost, the third is to increase income on the same cost, the fourth is to decrease cost on the same income. It is essential to find out what the urgent investment is and what unnecessary cost is. At last, in order to competite world shipping race, each shipping firm must try for himself to retain the power. The government/authority is no longer dependable. I believe that each firm's power will be the industry's power, the industry's power will be the nations's power.
There is a vessel which shall not impede the passage of any other vessel in the COLREGS 1972. But the issue was raised that the words of "not to impede" were vague. Therefore, IMO adopted new paragraph (f) to be added to Rule 8 that a vessel which is required not to impede the passage of another vessel is not relieved of this obligation if approaching the vessel so as to involve risk of collision. It means that the ship which is obliged not to impede should contributes to avoid collision and to the safe passage of the other vessel. Also it results that the application of Collision Rules should be changed. But until now, it seems that the mariners are not familiar with this subject. This paper, therefore, aims to define the meaning of "not to impede" and clarify it's legal concept so as to adequate application of the Collision Rules for the collision avoidance at sea.on avoidance at sea.