• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.515-519
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• 2004

A Propeller-Anemometer is an instrument used specifically, to measure the wind speed. The accurate measurement of the wind speed is vitally important such required by any weather stations. In this research, the measurand of the instrumentation was the rotational speed of the propeller and the instrumentation result or output data was wind velocity. The speed measured was recorded digitally in the computer by using specific software. A specific sensor used to measure a variable by converting information of the variable (rotational speed of the propeller) into a dependent signal such as electrical signal in form of voltage. The development of Propeller-Anemometer involved few sets of instrumentation process and equipment. It included three major parts, mechanical, electronics and computer. The main instrumentation processes were physical and signal interfacing, signal conditioning, logic interfacing, data transmission to computer and processing the data. Generally, this paper presents the overall concept and design of Propeller-Anemometer Instrumentation. However, an emphasis was mainly in designing and building the interfacing system, hardware and software. Basically, for the first phase of the development, this project designed and built the RS232 terminal using Peripheral Interface Controller (PIC), PIC16F873. The hardware can be interfaced to computer or other compatible devices. This routine converted input voltage from the circuit to speed (velocity) and transmitted them afterwards to the target device by using the RS232 transmission protocol. This implementation implied a computer display as visual interface. For the purpose of this paper, RS232 data transmission was carried out using a Microsoft Visual Basic software routine.

• The KSFM Journal of Fluid Machinery
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• v.4 no.2 s.11
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• pp.7-14
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• 2001

Design and development of a propeller fan for a cooling tower have been accomplished by both numerical prediction of performance and experimental validation with a wind tunnel. Main interest lies on blade geometry of a fan for optimal design of aerodynamic performance. A commercial program, Fine/Turbo used for the present numerical estimation, gives us engineering information such as flow details near the blades and flow rate of the system. The numerical results are compared with precise experimental output and show good agreement in comparison between the two data. Also new proposed model of a blade shows improved performance relative to present running model in market.

• Journal of the Society of Naval Architects of Korea
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• v.40 no.6
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• pp.69-79
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• 2003

Existing large-scale complex programs usually reside In a single computer, and the user has to be physically in contact with the computer. With the wide spread use of the internet, the need to carry out the design and analysis tasks geographically away from the main computer is increasing. In this paper existing Windows-based propeller design and analysis package is separated into the server-client modules and the protocol program is developed to implement the communication between multi-client computers and a single server computer. A new protocol packet is designed to use the Windows socket and the server/client programs control the receive/send operations using the information transmitted in the packet. Test runs show that the remote user, connected to the server computer through the internet only, can perform the required tasks.

• The Journal of the Acoustical Society of Korea
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• v.31 no.6
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• pp.384-390
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• 2012

Passive sonars employ DEMON(Detection of Envelope Modulation on Noise) processing to extract propeller information from the radiated noise of underwater targets. However, the conventional DEMON processing suffers from the interference of tonal signals because it extracts propeller signals and some types of tonal signals as well. If there are some tonals in the frequency band for DEMON processing, the conventional DEMON processing may additionally extract frequency informations originated from the interaction between different tonals. In this paper, we propose a modified DEMON processing, which can eliminate the interference of the tonals. The proposed algorithm removes tonals in DEMON processing band before demodulation processing, hence results the robustness to the interference of the tonals. Some numerical simulations demonstrate the improved performance of the proposed algorithm against the conventional algorithm.

• Journal of Information Technology Applications and Management
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• v.25 no.1
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• pp.1-17
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• 2018

This study presents a research model that demonstrates the dominant design technology strategy for developing and securing dominant design technology based on open innovation. For this purpose, this study developed a strategic model for the development and acquisition of design technology, production technology, and production system of propeller which satisfies the requirements of ship propulsion system required by ship owners and shipbuilders. By studying large propellers for ships, it is possible to embody a strategic model that can be used as a technology development strategy of dominant design that is effective in technology field of other industries. In this study, HSP (High Skewed Propeller) strategy of Hyundai Heavy Industries, which occupies the largest global market share (47.5%, 2007) for more than 30 years until now, is analyzed as a successful case to verify this strategic model. The development and acquisition strategy model of dominant design technology presented in this study consists of four stages : dominant design project strategy, dominant design engineering technology strategy, dominant design production technology strategy, and dominant design production system strategy. The strategic model summarizes the key activities at each stage. In addition, the steps and core activities of this strategic model were confirmed through the case study. As a technology development strategy of HSP products, Hyundai Heavy Industries utilized open innovation technology to cooperate with outside, that is, collaborative research and development with KAIST (Korea Advanced Institute of Science and Technology) research team, and succeeded in achieving technology development of dominant design of HSP products by linking it with HSP technology development and acquisition strategy.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.08a
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• pp.149-150
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• 2008

Generally, the propeller shaft rate (PSR) estimation algorithm for the classification of the sonar target has the following problems: it requires both accurate and efficient the fundamental finding method because it is essential and difficult to distinguish harmonic family from the frequency spectrum, and further, it requires an easy design procedure in terms of its structures and parameters. To solve these problems, an evolutionary PSR estimation algorithm using an expert knowledge and the evolution strategy, is proposed. Simulation results show that the proposed algorithm effectively solves the problems in the realtime system application.

• International Journal of Naval Architecture and Ocean Engineering
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• v.4 no.1
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• pp.44-56
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• 2012

Autonomous Underwater Vehicles (AUVs) provide a useful means of collecting detailed oceano-graphic information. The hull resistance of an AUV is an important factor in determining the power requirements and range of the vehicle. This paper describes a procedure using Computational Fluid Dynamics (CFD) for determining the hull resistance of an AUV under development, for a given propeller rotation speed and within a given range of AUV velocities. The CFD analysis results reveal the distribution of the hydrodynamic values (velocity, pressure, etc.) around the AUV hull and its ducted propeller. The paper then proceeds to present a methodology for optimizing the AUV profile in order to reduce the total resistance. This paper demonstrates that shape optimization of conceptual designs is possible using the commercial CFD package contained in Ansys$^{TM}$. The optimum design to minimize the drag force of the AUV was identified for a given object function and a set of constrained design parameters.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.4
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• pp.412-418
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• 2020

Generally, the propeller shaft that constitutes the ship shaft system has different patterns of behavior due to the ef ects of engine power, propeller load and eccentric thrust, which increases the risk of bearing failure by causing local load variations. To prevent this, different studies of the propulsion shaft system have been conducted focused the relative inclination angle and oil film retention between the shaft and the support bearing, mainly with respect to the Rules for the Classification of Steel Ships. However, in order to secure the stability of the propulsion shaft via a more detailed evaluation, it is necessary to consider dynamic conditions, including the transient state due to sudden change in the stern wakefield. In this context, a 50,000 DWT vessel was analyzed using the strain gauge method, and the effects of propeller shaft movement were analyzed on the starboard rudder turn which is a typical transient state during normal continuous rate(NCR) operation in ballast draught condition. Analysis results confirm that the changed propeller eccentric thrust acts as a force that temporarily pushes down the shaft to increase the local load of the stern tube bearing and negatively affects the stability of the shaft system.

• 한국전산유체공학회:학술대회논문집
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• 2000.10a
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• pp.163-169
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• 2000

Design and developments of a propeller fan for a cooling tower have been accomplished by both numerical prediction of performance and experimental validation with a wind tunnel, Main interest lies on blade geometry of a fan for optimal design of aerodynamic performance. The present methodology for numerical estimation is commercial program, Fine/Turbo, which gives us engineering information such as flow details near the blades and flow rate of it. The numerical results are compared with precise experimental output and show good agreement. Also new proposed model of a blade with the program show improved performance relative to present running model in market.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.1
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• pp.32-37
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• 1998

This paper deals with the implementation of a robust multivariable controller using DSP board and the application to real systems. The LQG/LTR (Linear Quadratic Gaussian with Loop Transfer Recovery) controller proposed by Doyle et al.[1,2] is adopted to design the control system. A helicopter propeller setup is taken as the controlled system in the current paper, and the mathematical model is derived to design the multivariable controller. The performance of the controller is evaluated via simulations, and implementation and application to the MIMO system shows that the control performances are satisfactory and superior to those of the PID controller.