간행물
Journal of Korean Navigation and Port Reserch KCI 등재 한국항해항만학회지
- 발행기관 한국항해항만학회
- 자료유형 학술지
- 간기 격월간
- ISSN 1598-5725 (Print)2093-8470 (Online)
- 수록기간 1977 ~ 2020
- 주제분류 농수해양 > 해상운송학 농수해양 분류의 다른 간행물
- 십진분류KDC 559DDC 629
권호리스트/논문검색
Vol.31 No.9 (2007년 12월) 8건
1.
2007.12
서비스 종료(열람 제한)
The authors aim to establish the theory necessary for developing free gyro positioning system and focus on measuring the nadir angle by using the motion rate of a free gyro. The azimuth of a gyro vector from the North can be given by using the property of the free gyro. The motion rate of the spin axis in the gyro frame is transformed into the platform frame and again into the NED (north-east-down) navigation frame. The nadir angle of a gyro vector is obtained by using the North components of the motion rate of the spin axis in the NED frame. The component has to be transformed into the horizontal component of the gyro by using the azimuth of the gyro vector and then has to be integrated over the sampling interval.
2.
2007.12
서비스 종료(열람 제한)
A novel miniaturized CMOS C-Band bandpass filter based on diagonally end-shorted coupled lines and interdigital capacitors is proposed. The utilized coupled lines structure reduced the configuration in size, as small as a few degrees. Moreover, the characteristic of interdigital capacitor, relatively high Q and good capacitance tolerance, accounts for the satisfied performance of this new filter. A two-stage bandpass filter was designed and fabricated with chip surface area only 1.02×1.4 mm2.
3.
2007.12
서비스 종료(열람 제한)
A narrow loop noise bandwidth method is desirable to reduce the error of raw measurements due to the thermal noise. However, it degrades the performance of GPS initial synchronization such as mean acquisition time. And it restricts the loop noise bandwidth to a fixed value determined by the lower bound of the allowable range of carrier-to-noise power ratio, so that it is difficult to optimally track GPS signal. In order to make up for the weak points of the fixed-type narrow loop noise bandwidth method and simultaneously minimize the error of code and carrier measurements, this paper proposes a stepwise-type adaptive bandwidth algorithm for DGPS reference receivers. In this paper, it is shown that the proposed adaptive bandwidth algorithm can provide more accurate measurements than those of the fixed-type narrow loop noise bandwidth method, in view of analyzing the simulation results between two signal tracking algorithms. This paper also carries out sensitivity analysis of the proposed adaptive bandwidth algorithm due to the estimation uncertainty of carrier-to-noise power ratio. Finally the analysis results are verified by the experiment using GPS simulator.
4.
2007.12
서비스 종료(열람 제한)
A container terminal gate is not only an entrance of containers, but also the first input point of containers' information. Therefore, to achieve the accuracy of container information, there are various containers' numbers recognition methods used. Gate productivity can significantly vary depending upon those recognition methods. Recently, RFID which is one of the u-IT businesses run by the Korean government is under consideration for application to the gate as an automatic system. If RFID is used, it is expected to have both the qualitative benefits through avoiding defects of other systems and the quantitative benefits by improving productivity. Hence, this study aims to provide some insight on the benefits of RFID, and to compare productivity of the existing gate system with the RFID gate system based on computer simulation.
5.
2007.12
서비스 종료(열람 제한)
Design and Implementation of PDA-based Image Surveillance System for Harbor Security using IP Camera
This paper describes a new progressive embedded Internet Protocol(IP) camera available for real-time image transmission. It was applied for ship safety and security on seashore area. The functions of developed embedded system was more effective and excellent than conventional systems. Nowadays, each nation has established harbor security systems to jump up their ports to international port. Recently Incheon port has tried to change man security into center security system used by image security system. The security system of Incheon port has some advantages like effectivity of security system and reduction of manpower and cost, installed by image security system with CCTV cameras at the entrance gate and around the fence. Thus in this paper, we have designed and implemented a Personal Digital Assistants(PDA) based Image Surveillance System for Harbor Security using IP Camera under ubiquitous environment. This system has big advantages which are more effective in an emergency and low cost and small manpower than conventional systems.
6.
2007.12
서비스 종료(열람 제한)
In this paper we proposed a model that the deformation of the submerged rubble mound breakwaters composed with materials of various size, induced by wave action, can be computed. The water particle kinematics by waves in porous mound structure are computed by CADMAS-SURF, then the deformation of structure is computed using DEM module. To investigate the interaction of wave and sectional deformation of structures, analysis is accomplished by two steps. Analysis at the first step is executed with incipient mound. And analysis at the second step is executed with deformed mound by wave action. Furthermore, behaviors of materials are influenced by various properties such as the contact stiffness and the friction angle. Therefore, in order to present the behavior of the element caused by various properties, computations are accomplished with random coefficients by using the Monte Carlo simulation.
7.
2007.12
서비스 종료(열람 제한)
The effect of seasonal wind on the tidal circulation in Jeju harbor was examined by using a numerical shallow water model. A finite element for analyzing shallow water flow is presented. The Galerkin method is employed for spatial discretization. Two step explicit finite element scheme is used to discretize the time function, which has advantage in problems treating large numbers of elements and unsteady state. The numerical simulation is compared with three cases; Case 1 does not consider the effect of wind, Case 2 and Case 3 consider the effect of summer and winter seasonal wind, respectively. According to result considering effect of seasonal wind, velocity of current vector shows slightly stronger than that of case 1 in the flow field. It can be concluded that the present method is a useful and effective tool in tidal current analysis.
8.
2007.12
서비스 종료(열람 제한)
The analytical hierarchy process (AHP) enables decision makers to represent the interaction of multiple factors in complex and unstructured situations. The process requires the decision maker to develop a hierarchical structure of the factors in the given problem and to provide judgments about the relative importance of each of these factors and ultimately to specify a preference for each decision alternative with respect to each factor. The research presented in this paper applies the AHP to identify key players in promoting port competitiveness. The literature survey revealed four major criteria and 15 sub-criteria. The four factors are cost, service quality, facility/capacity and economic-social variable. 150 questionnaires suitable for AHP analysis were made and 77 were returned. It is found that in terms of cost, the first key player is terminal operator and the second key player is shipping companies calling Busan port; in terms of service quality, the first key player is terminal operator, and the second key player is shipping companies calling Busan port; in terms of facility/capacity, the first key player is port authority and the second key player is terminal operator; in terms of economic-social variable, the first key player is terminal operator, and the second key player is shipping companies calling Busan port.
