• Journal of Power Electronics
• /
• v.15 no.4
• /
• pp.1047-1053
• /
• 2015

A time-domain simulation tool to predict the dynamic power output of wind turbines in an offshore wind farm was developed in this study. A wind turbine model consisting of first or second order transfer functions of various wind turbine elements was combined with the Ainslie's eddy viscosity wake model to construct the simulation tool. The wind turbine model also includes an aerodynamic model that is a look up table of power and thrust coefficients with respect to the tip speed ratio and pitch angle of the wind turbine obtained by a commercial multi-body dynamics simulation tool. The wake model includes algorithms of superposition of multiple wakes and propagation based on Taylor's frozen turbulence assumption. Torque and pitch control algorithms were implemented in the simulation tool to perform max-Cp and power regulation control of the wind turbines. The simulation tool calculates wind speeds in the two-dimensional domain of the wind farm at the hub height of the wind turbines and yields power outputs from individual wind turbines. The NREL 5MW reference wind turbine was targeted as a wind turbine to obtain parameters for the simulation. To validate the simulation tool, a Danish offshore wind farm with 80 wind turbines was modelled and used to predict the power from the wind farm. A comparison of the prediction with the measured values available in literature showed that the results from the simulation program were fairly close to the measured results in literature except when the wind turbines are congruent with the wind direction.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.4
• /
• pp.641-647
• /
• 2007

It has been said that Warehouse Management System(WMS) in e-Trade has considerably contributed to improvement of distribution industry. However, in the aspect of management we have many technical problems such as transportation due to tremendous demands of online data. Therefore, for Korea to be a hub of distribution and information, this is the best time to prepare the foundation of Supply Chain Management(SCM) under Enterprise Resource Planning (ERP) the and make a good use of WMS. The purposes of this study are presented as follows: First, it is to examine the general flow process of WMS in each field of our e-Trade Second, it is to present problems and plans of improvements involved in WMS in e-Trade. In short, this study aims at presenting interpretative foundation of WMS in a practical viewpoint, not presenting technical directions of WMS.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.23 no.11
• /
• pp.1397-1406
• /
• 2019

In everyday mobile phone calls between the disabled and non-disabled people due to neurological impairment, the communication accuracy is often hindered by combining the accuracy of pronunciation due to the neurological impairment and the pronunciation features of the disabled. In order to improve this problem, the limiting method is MEMS (micro electro mechanical systems), which includes an induction line that artificially corrects difficult vocalization according to the oral characteristics of the language impaired by improving the word of out of vocabulary. mechanical System) Microphone device improvement. S/W improvement is decision tree with invert function, and improved matrix-vector rnn method is proposed considering continuous word characteristics. Considering the characteristics of H/W and S/W, a similar dictionary was created, contributing to the improvement of speech intelligibility for smooth communication.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.24 no.4
• /
• pp.357-367
• /
• 2021

This paper studies the simulations of active airframe vibration controls for the Sikorsky X2 helicopter with a lift-offset coaxial rotor. The 4P hub vibratory loads of the X2TD rotor are obtained from the previous work using a rotorcraft comprehensive analysis code, CAMRAD II. The finite element analysis software, MSC.NASTRAN, is used to model the structural dynamics of the X2TD airframe and to analyze the 4P vibration responses of the airframe. A simulation study using Active Vibration Control System(AVCS) with Fx-LMS algorithm to reduce the airframe vibrations is conducted. The present AVCS is modeled using MATLAB Simulink. When AVCS is applied to the X2TD airframe at 250 knots, the 4P longitudinal and vertical vibration responses at the specified airframe positions, such as the pilot seat, co-pilot seat, engine deck, and prop gearbox, are reduced by 30.65 ~ 94.12 %.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.25 no.8
• /
• pp.1088-1094
• /
• 2021

This paper proposes a partial BMA (Broadcasting Multiple Access) network structure and D-ARP (Distributed Address Resolution Protocol) method in order to support full mesh routing function in the DAMA (Demand Assigned Multiple Access)-based MF-TDMA (Multi Frequency-Time Division Multiple Access) satellite system. The partial BMA network enables legacy router devices and routing protocols to be adopted in the satellite communication system, and decreases the amount of routing protocol overhead. In addition, we introduce the D-ARP method that help a spoke satellite node acquiring the MAC (Media Access Control) address from remote satellite nodes in none BMA satellite network. The D-ARP method provides the MAC address of remote nodes to each other nodes through the broadcasting-enabled satellite channel. And we lastly evaluate and analysis the network performance of the proposed approach.

• Journal of Navigation and Port Research
• /
• v.36 no.10
• /
• pp.895-904
• /
• 2012

Today, the competition for hub-port is getting fierce and the shipping liners have enjoyed the increased bargaining power over the terminal operators through the mergers & acquisitions (M&A) and strategic alliances. This result leads the competition among terminal operators to attract liner companies and cargoes in their terminals. In demand side, however, there is a limited container cargo volume to handle because of a steady growth of cargo traffic. While, in supply side, continuous development of port terminals increased more competition among ports or terminals for cargoes. In particular the terminal operating market of Busan port is distorted because of the cargo competition between Busan North-port and Newport. The main purpose of this study is to suggest the stabilization measures of container terminal operating market in Busan port through analysis of the terminal operation market structures and market survey analysis method. For stabilizing the container terminal market, this study suggests the improvement of the legal and institutional system such as improvement in determining and reporting system of stevedoring tariff, establishment of fair competition rules etc., the introduction of port pooling system and adoption of volume-linked terminal lease system with cargo volume ceiling system for each terminal operator.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.18 no.4
• /
• pp.701-708
• /
• 2023

Local governments are required to take measures to prevent occupational accidents under Articles 4(2) and 4(3) of the Occupational Safety and Health Act, and this study suggested the necessity of establishing an IT-based integrated safety and health information sharing system for serious accident reduction and safety and health management through the case of Incheon Metropolitan City. Recently, as local governments have established labor and health ordinances and basic plans, the need for an independent integrated safety and health management system based on local industrial characteristics has increased. It is necessary to establish a cooperation and support system with basic local governments and hub institutions, share integrated safety and health information with related institutions and organizations, and play a pivotal role in regional safety and health management by managing occupational accident statistics and implementing basic policies. The system through local governments' safety and health management will reduce serious accidents in the region, and the comprehensive safety and health management system for small businesses and projects ordered by local governments will strengthen the operability of the site, which will be effective in preventing critical accidents and industrial accidents.

• The Journal of the Convergence on Culture Technology
• /
• v.10 no.2
• /
• pp.273-278
• /
• 2024

The purpose of this study is to examine the limitations of university operating system changes as a result of the policy changes and outcomes of the university lifelong education system support project by project period, and based on this, to propose a development plan to support the university's adult learning system. In this study, we sought to investigate changes in the higher education environment and changes in lifelong education in universities through analysis of literature and various data. The changing times of technological innovation and changes in knowledge require continuous learning even after school education, and the need for re-education and improved education is increasing. Therefore, the Ministry of Education and the National Institute for Lifelong Education have been actively carrying out support projects for lifelong learning-centered universities since 2008 to provide adult learners with opportunities to study. This project is centered around universities and the local community, and is promoting various types of changes in educational operation, such as reforming the university's academic system to be adult-friendly and operating night or weekend classes in order to provide educational opportunities for adult learners. Now, universities must play a role as a hub of regional lifelong education for the coexistence of the region and university, and as a key institution responsible for the contemporary tasks of sustainable development and coexistence between the university and the community.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.37 no.1
• /
• pp.125-132
• /
• 2017

The development project of Busan New Port aims to be Logistics Hub Port but there are too many things to deal with ; enlargement of harbour, interport competition, modernization of harbour loading equipment and so on. At present, 23 berths of North and South container quay are in operation and 22 berths will be constructed on west and south-side by 2020. Namely, Busan New Port will operate 45 berths in 2020. When it comes to port distripark, a large-scale of Port distripark project is underway, such as Ung-Dong district 1,2 phase, West container 1,2phase, North distripark and so on. This study is to deduce traffic system problem of Busan New Port which is caused by the development project through predicting traffic need considering the development project. According to study, there are three main problems of traffic system : 1. traffic congestion caused on main crossroad, connecting second harbour back road. 2. It has been predicted that South-North road and traffic capacity of New Port road would lack compared to traffic volume-to-be-increased. Moreover, the detour volume of traffic is caused because New Port's 1st avenue and route 2 were not connected directly. Thus, this study suggests three kinds of improvement plan for smoother traffic flow. 1st. Operate roundabout on major intersection, for example, second harbour back road, west container wharf's subway corridors(South to North), and permit only right turn on sub-intersection. 2nd. Extend New Port road(North container's port road) by utilizing side walk and median. 3rd. Install exit ramp which utilizes Route 2 connecting New Port's 1st avenue and local road 1042. The method we used to analyze the effect of improvement is Vissim of Mircro Simulation Package.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.10 no.1
• /
• pp.92-101
• /
• 2007

Urban freight system includes not just intra-urban freight movement but also inter-urban movement as well. Hence, to make Busan a hub of North-east asia freight movement it is necessary to develop a comprehensive plan for infrastructure expansion as well as improvement of freight system based on the present facility situation. This study identifies the status of freight facilities in Busan by establishing the freight related infrastructure Database(DB) utilizing Geographic Information System(GIS), and to enable planners and decision-makers to utilize the DB to develop a future plan. The DB includes port facilities, major and minor arterial roads, railroad lines and facilities, depots, center city business areas, and urban infrastructures which are related to the freight movements. The analyses show that major transportation facilities in Busan consist of roads, railroads, coastal transportation, and international transportation, and it was found that intermodal facilities are inadequate for freight system in Busan. The results of this study will be useful for freight experts and planners to develop a comprehensive freight system plan.