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.30 No.2 (2006년 3월) 8건
1.
2006.03
서비스 종료(열람 제한)
In Part I(theoretical study) of the paper, a new adaptive autopilot for ships based on Adaptive Neural Networks was proposed. The ANNAI autopilot was designed for course-keeping, turning and track-keeping control for ships. In this part of the paper, to show the effectiveness and feasibility of the ANNAI autopilot and automatic selection algorithm for learning rate and number of iterations, computer simulations of course-keeping and track-keeping tasks with and without the effects of measurement noise and external disturbances are presented. Additionally, the results of the previous studies using Adaptive Neural Network by backpropagation algorithm are also showed for comparison.
2.
2006.03
서비스 종료(열람 제한)
Waves, which are the main source of ship motions in a seaway, considerably affect the performance of a ship. The study of waves and their impact on ship motions within harbors is an important aspect of the design and operation of harbors. The prediction of incoming groups of waves is particularly important for evaluating ship motion within a harbor. Such a prediction makes it possible to evaluate ship safety more accurately. The wave transformation model reported here is applied to actual ports based on Boussinesq wave equations both non-linear and dispersive wave processes be considered in order to capture physical effects such as wave shoaling, refractions, reflection and diffraction in variable depth environments. The prediction of incoming groups of waves is particularly important for evaluating ship motion within a harbor, Such a prediction makes it possible to evaluate ship safety more accurately and provide safe wave informations for navigation. Furthermore, a wave information support system is proposed for entering ships as one technique for improving the safety of ship operations. This system predicts the run of waves and reduces the danger by identifying the most dangerous point near the harbor entrance at the small wave groups.
3.
2006.03
서비스 종료(열람 제한)
Researches on a superstructure built on a floating structure in the shape of pontoon type have begun in recent years. A superstructure responds by wave load and it is important to evaluate its habitability. The purpose of this study is evaluation and investigation of habitability of a superstructure due to wave for 10 year return period. In this study, response analyses of the superstructure built on middle-sized floating structure due to the waves of three cases were carried out by 3-D integration analysis, which means analyzing the calculation model integrated a superstructure with a floating structure, and its habitability was evaluated by the evaluation diagrams. As the result, the habitability differed by each wave condition The use of a superstructure is restricted according to the disposition of a floating structure for incident wave angle.
4.
2006.03
서비스 종료(열람 제한)
The optimum grillage design belongs to nonlinear constrained optimization problem. The determination of beam scantlings for the grillage structure is a very crucial matter out of whole structural design process. The performance of optimization methods, based on penalty functions, is highly problem-dependent and many methods require additional tuning of some variables. This additional tuning is the influences of penalty coefficient, which depend strongly on the degree of constraint violation. Moreover, Binary-coded Genetic Algorithm (BGA) meets certain difficulties when dealing with continuous and/or discrete search spaces with large dimensions. With the above reasons, Real-coded Micro-Genetic Algorithm (RμGA) is proposed to find the optimum beam scantlings of the grillage structure without handling any of penalty functions. RμGA can help in avoiding the premature convergence and search for global solution-spaces, because of its wide spread applicability, global perspective and inherent parallelism. Direct stiffness method is used as a numerical tool for the grillage analysis. In optimization study to find minimum weight, sensitivity study is carried out with varying beam configurations. From the simulation results, it has been concluded that the proposed RμGA is an effective optimization tool for solving continuous and/or discrete nonlinear real-world optimization problems.
5.
2006.03
서비스 종료(열람 제한)
Recently we have seen a noticeable trend in ports to establish port clusters. Despite this trend, little research has actually been undertaken to fully define and analyse port clusters. A couple of exceptions have descriptively defined port clusters but the boundaries of port clusters are not apparent. Therefore, the aim of this paper is to define port clusters in terms of set theory and in particular look at them in terms of their distinct characteristics and system boundaries. The main concern of this paper is that there is a need to distinguish, from a system and a competition perspective, between port clusters, ports, maritime clusters and port ranges. This paper proposes a conceptual model relevant to the relationship among port clusters related assemblages and that has been applied to the north western europe region This model suggests six levels of competition that will help port authorities and government to develop appropriate policies and strategies for port operation and port industry.
6.
2006.03
서비스 종료(열람 제한)
This study intends to surveyrequirements for port and logistics supply chain management with RFID {Radio Frequency IDentification)technology. Port and logistics supply chain management has become a critical issue due to the necessity of efficiency, visibility, trace-ability, etc. Since the introduction of RFID technology, its performance, reliability, validity, and safety have been a concern in most industries. Particularly, in port and logistics supply chain management, RFID has the potential to track the movement of containers and to provide in-transit visibility toward customers. In thispaper we consider some critical issues related to port and logistics supply chain management, which previously adopted RFID technology. In order to successfully design and adopt RFID technology and utilize it as optimally as is possible in the port and logistics industry, it is necessary to understand the potential of shipping companies and their requirements in adopting RFID technology in port and logistics.
7.
2006.03
서비스 종료(열람 제한)
In order to construct an Anechoic Chamber satisfying international standards for EMI testing, it has been recognized that the absorption characteristics of the EM wave absorber must be higher than 20 dB over the frequency band from 30 MHz to 18 GHz. In this paper, an EM wave absorber with super wide-band frequency characteristics was proposed and designed in order to satisfy the above requirements by using the Equivalent Material Constant Method(EMCM) and Finite Difference Time Domain(FDTD). The proposed absorber is to attach a pyramidal absorber onto a hemisphere-type absorber on a cutting cone-shaped ferrite. As a result, the proposed absorber has absorption characteristics higher than 20 dB over the frequency band from 30 MHz to more than 20 GHz.
8.
2006.03
서비스 종료(열람 제한)
A scalar MSDD with multiple antenna reception of Differential Space-Time π/2-Shifted BPSK Modulation
In this paper, the issue of blind detection of Alamouti-type differential space-time (ST) π/2-shifted BPSK modulation in static Rayleigh fading channels is considered. We introduce a novel transformation to the received signal from each receiver antenna such that this binary ST modulation, which has a second-order transmit-diversity, is equivalent to QPSK modulation with second-order receive-diversity. The pre-detection combining of the result of transformation allows us to apply a low complexity detection technique specifically designed for receive-diversity, namely, scalar multiple-symbol differential detection (MSDD). With receiver complexity proportional to the observation window length, our receiver can achieve the performance 1.5dB better than that of conventional differential detection ST and 0.5dB worse than that qf a coherent maximum ratio combining receiver (with differential decoding) approximately.
