• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2003.05a
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• pp.121-125
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• 2003

A theme park plays an important role as a preferred facility for attracting international and domestic tourists. Many local autonomies try to establish theme parks within their own territory. Busan Metropolitan City also places emphasis on hosting an outstanding theme park, and to be identified as the tourism destination toward the world city in 21st century. The purpose of this paper is to suggest tourism policy and management strategy based on the literature review and survey analysis to international tourists. First, it is needed to supply low land price to reduce construction cost and to invite investors. Second, the theme park has to have an attractive theme and new events for repeaters Third, infra structures related to the theme parks are necessarily provided for high accessability. Finally, more priority is placed on public relation for citizen and service education of the industry.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2003.05a
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• pp.257-264
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• 2003

The international oil majors have been reducing the size of their own oil tanker fleet since from the beginning of 1980s. Like international oil majors, the Korean refineries are getting more dependent on tanker chartering than tanker ownership for their oil transportation since 1990s. They also prefer spot charter to time charter and this kind of trend continue up to today. Consequently, this paper attempted to find out factors influencing changes in tanker fleet composition. To attain the object, a empirical study is adopted using the ten decision making factors derived from the preceeding study. The findings are that MARPOL and OPA 90, and transportation cost are the most important factors influencing on oil tanker fleet composition.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.225-233
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• 2006

Creating more efficient and effective intermodal transportation service in Northeast range is a critical issue because of more increased trade volume & demand for intermodal service in the world market and geographical barriers associated with goods transportation, especially in Korea, China and Japan. This study examines the possibility of Rail-ferry in Northest area which can provide each countries mutual economical and logistical satisfaction.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.181-184
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• 2006

Knowledge of the ionospheric peak parameter foF2 (the critical frequency of F2 layer) is one of key essential factors for predicting ionospheric characteristics and delay correction of satellite positioning. However, the foF2 was almost estimated using an empirical model of International Reference Ionosphere (IRI) or other expensive observing techniques, such as ionosondes and scatter radar. In this paper, the ionospheric peak parameter foF2 is the first observed by ground-based GPS with all weather, low-cost and near real time properties. Compared with the IRI-2001 and independent ionosondes at or near the GPS receiver stations, the foF2 obtained from ground-based GPS is in better agreement, but closer to the ionosonde. However, during nighttime, the IRI model overestimated the GPS observed values during winter and equinox months.Furthermore, seasonal variation trend of the foF2 in 2003 is studied using foF2 monthly median hourly data measured over South Korea. It has shown that the systematic diurnal changes of foF2 are apparent in each season and the higher values of foF2 are observed during the equinoxes (semiannual anomaly) as well as in mid-daytime of each season.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.103-107
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• 2006

At present, most efforts tend to develop a INS which is only based linear accelerometers, because of the low cost micro-machining gyroscopes lack of the accuracy needed for precise navigation application and possible achieving the required levels of precise for micro-machining accelerometer. Although it was known in theory that a minimum of six accelerometers are required for a complete description of a rigid body motion, and any configuration of six accelerometers (except for a "measure zero " set of six-accelerometer schemes) will work. Studies on the feasible configuration of GF-INS indicate that the errors of angular velocity resolved from the six accelerometers scheme are diverged with time or have multi solutions. The angular velocity errors are induced by the biases together with the position vectors of the accelerometers, therefore, in order to treat with the problem just mentioned, researchers have been doing many efforts, such as the extra three accelerometers or the magnetometers may be taken as the reference information, the extended Kalman filter (EKF) involved to make the angular velocity errors bound and be estimated, and so on. In this paper, the typical configurations of GF-INS are introduced; for each type GF-INS described, the solutions to the angular velocity and the specific force are derived and the characteristic is indicated; one of the corresponding extend Kalman filters are introduced to estimate the angular errors; parts of the simulation results are presented to verify the validity of the equations of angular velocity and specific force and the performance of extend Kalman filter.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.217-222
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• 2006

To find a location, GPS has been wildly used. But, it is hard to use in indoor because of very weak signal level. To meet indoor requirements, there have been many studies applying wireless communication networks such as WLAN, UWB and ZigBee. Among these, ZigBee is widely adopted in many WSN applications because it has an advantage of low-power and low-cost. In ZigBee, the RSSI is used as range measurement for ad-hoc network. The RSSI are converted to ranges using the signal attenuation model and these ranges become inputs of positioning methods. The obtained position with RSSI has large error because of its poor accuracy. To overcome this problem, ultrasonic sensors are added in many researches. By measuring the arrival time difference of ZigBee and ultrasound as a range measurement, the precise position can be found. However, there are still many problems: scheduling of beacons to transmit signals in a correct order, addition and synchronization of beacons and low-rate positioning rate. At this paper, an efficient method to solve these problems is proposed. In the proposed method, a node transmits ZigBee and ultrasound signal simultaneously. And beacons find the range with the received signals and send it back to a node with ZigBee. The position is computed in a node with the received ranges. In addition, a new positioning algorithm to solve the risk of the divergence in the linearization method and the singularity problem in the Savarese method is presented. Both static and dynamic experimental results show 0.02m RMS errors with high output rate.

• Journal of Navigation and Port Research
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• v.35 no.5
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• pp.381-385
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• 2011

In this paper, an economic feasibility study of wind-diesel hybrid power systems for an island in the Yellow Sea, where the maximum power generation is about 500kW, was performed. For the study, annual electric load variation and wind resource data of the island were collected and analyzed. HOMER program - a typical hybrid optimization model for electric renewables including wind resource, developed by the National Renewable Energy Laboratory - was used. Wind speed and diesel price were picked out as variables for the sensitivity analysis in order to find the economic accountability for the wind-diesel hybrid power system. As the result, even though it is not feasible economically under the present condition, if mean wind speed is over 3 m/sec. or diesel price goes up to 2.4 $ per liter, the wind-diesel hybrid power system for the island becomes a prospective candidate.

• Journal of Navigation and Port Research
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• v.35 no.5
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• pp.455-462
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• 2011

The accident in the Fukushima nuclear plant caused by the Great East Japan Earthquake on March 11, 2011 is raising voices concerning over radioactive contamination losses. In particular, radioactive contamination losses threaten the safe navigation of vessels, and may impair seafarers' safety and impede the healthy growth of world economy through marine transportation. In case vessels or cargos suffer radioactive contamination losses, it will take a high cost to remove the radioactive contaminants, and in worse cases the contaminated vessels or cargos may have to be abandoned. Furthermore, if seamen are exposed to radioactivity, their treatment can be raised as a crucial issue. Nevertheless, it has not been reviewed clearly by what method and on what ground such losses should be covered in case radioactive contamination losses take place. Thus, this study purposed to review coverage for radioactive contamination losses in marine insurance as an ex post preparation for damages caused by radioactive contamination.

• Journal of Navigation and Port Research
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• v.31 no.10
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• pp.853-858
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• 2007

In this paper, a seesaw system composed with a moving cart on the rail and seesaw frame is made to demonstrate the effectiveness of the control theory. The control aim is to maintain an equilibrium of seesaw frame in spite of various initial conditions and an allowable disturbance. To solve this control problem, a PI-type state feedback controller using reduced-order observer is implemented and applied to the seesaw system. The reduced-order observer can be used to estimate the state variables in the case of the limit of sensor number or the constraint on setting sensors and the cost. A series of simulation are carried out to verify the effectiveness of the control system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.10a
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• pp.73-74
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• 2009

This study attempts to establish a system extracting and monitoring cultural grounds of seaweeds (lavers, brown seaweeds and seaweed fulvescens) and abalone on the basis of both KOMPSAT-2 and Terrasar-X data. The study areas are located in the northwest and southwest coast of South Korea, famous for coastal cultural grounds. The northwest site is in a high tidal range area (on the average, 6.1 m in Asan Bay) and has laver cultural grounds for the most. An semi-automatic detection system of laver facilities is described and assessed for spaceborne optic images. On the other hand, the southwest cost is most famous for seaweeds. Aquaculture facilities, which cover extensive portions of this area, can be subdivided into three major groups: brown seaweeds, capsosiphon fulvescens and abalone farms. The study is based on interpretation of optic and SAR satellite data and a detailed image analysis procedure is described here. On May 25 and June 2, 2008 the TerraSAR-X radar satellite took some images of the area. SAR data are unique for mapping those farms. In case of abalone farms, the backscatters from surrounding dykes allows for recognition and separation of abalone ponds from all other water-covered surfaces. But identification of seaweeds such as laver, brown seaweeds and seaweed fulvescens depends on the dampening effect due to the presence of the facilities and is a complex task because objects that resemble seaweeds frequently occur, particularly in low wind or tidal conditions. Lastly, fusion of SAR and optic spatial images is tested to enhance the detection of aquaculture facilities by using the panchromatic image with spatial resolution 1 meter and the corresponding multi-spectral, with spatial resolution 4 meters and 4 spectrum bands, from KOMPSAT-2. The mapping accuracy achieved for farms will be estimated and discussed after field verification of preliminary results.