• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제5권9호
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• pp.247-260
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• 2016

센서네트워크는 스마트홈, 스마트 팩토리 등 다양한 분야에서 센서 데이터 기반으로 활용되고 있다. 이러한 센서네트워크는 그 활용 분야에 따라 시스템 아키텍처, 요구사항, 설계 등이 달라지게 된다. 현재 해양 환경은 지상 환경에 비해 접근하기가 굉장히 어렵고 높은 파고, 안개, 염분 등의 열악한 조건을 가지고 있어 센서네트워크의 응용분야가 굉장히 적은 단점이 있다. 따라서 본 논문에서는 연근해 가두리 양식장 모니터링을 위한 센서네트워크 시스템의 요구사항 분석과 아키텍처를 제안하고 이를 기반으로 연근해 가두리 양식장 모니터링을 위한 시스템을 설계한다. 또한 본 논문에서 설계한 시스템에 대해 실제 개발을 통해 운용하면서 얻은 결과를 제시한다. 본 연구를 기반으로 개발한 시스템은 연근해 가두리 양식을 위해 수집한 수중 데이터를 중심으로 양식에 필요한 각종 연관성 분석을 통해 가두리 양식에 적합한 수중 환경조건을 도출하고, 모니터링 및 관리할 수 있는 기능을 제공한다.

• 한국수산과학회지
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• 제43권2호
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• pp.159-168
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• 2010

This paper presents a mathematical model and simulation method for investigating the performance of set net systems and fish cage systems influenced by currents and waves. Both systems consist of netting, mooring ropes, a floating collar and sinkers. The netting and ropes were considered flexible structures and the floating collar was considered an elastic structure. Both were modeled on a mass-spring model. The structures were divided into finite elements and mass points were placed at the mid-point of each element, and the mass points were connected by mass-less springs. Each mass point was subjected to external and internal forces and the total force was calculated at every integration step. An implicit integration scheme was used to solve the nonlinear dynamic system. The computation method was applied to dynamic simulation of actual systems simultaneously influenced by currents and waves in order to evaluate their practicality. The simulation results improved our understanding of the behavior of the structure and provided valuable information concerning the optimized design of set net and fish cage systems exposed to an open ocean environment.

• 수산해양기술연구
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• 제40권3호
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• pp.214-224
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• 2004

어류 축양을 목적으로 외해에 설치되는 대형 가두리 시설은 해양환경 조건으로부터 다양한 외력을 받으며, 이러한 외력에 의한 가두리의 동태는 가두리 시설 자체의 안전과 축양물의 생존과 성장에도 큰 영향을 준다. 그러므로 가두리를 설계하는 단계에서 외력에 의한 가두리의 역학적 움직임을 정확히 파악할 수 있다면 보다 안전하고 효율성 있는 구조물을 설치 할 수 있을 것이다. 본 연구에서는 원형 가두리에 대하여 조류에 따른 가두리의 동역학적 운동을 해석하기 위하여 이론 모델을 구성하여 수치해석을 하였다. 이 때 수조실험을 통해 흐름에 놓여지는 망지의 여러 조건에 따른 망지 후방의 유속감소율을 적용함으로써 수치계산의 정확도를 높였다. 또한 수치 계산에 의한 시뮬레이션의 결과와 모형 실험에 의한 결과를 비교 분석하였다. 본 연구에서 얻어진 결과를 요약하면 다음과 같다. 1. 유속이 일정할 때 망지의 d/1가 커질수록 망지를 통과한 후의 유속은 감소하였다. 2. 망지의 d/1가 일정할 때, 유속이 커질수록 망지를 통과한 후의 유속은 증가하였다. 3. 망지의 d/1와 유속이 일정할 때, 망지로부터의 영각이 커질수록 망지를 통과한 후의 유속은 감소하였다. 4. 평면 망지 실험에서 얻어진 유속감소율을 적용한 시뮬레이션에 의한 수종 형상과 모형 실험에 의한 가두리의 수중 형상을 비교한 결과, 오차는 ${\pm}$ 5 % 이내로 나타나 실험결과에 대한 시뮬레이션의 결과가 잘 일치함을 나타내었다.

• 한국군사과학기술학회지
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• 제21권3호
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• pp.379-385
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• 2018

Boresight process is to match the misalignment between PNU(Position Navigation Unit) and the reference axis of K-MLRS cage. It is important process to ensure accuracy of K-MLRS. When PNU is removed from cage in the previous alignment procedure, there is a misalignment angle with cage of K-MLRS during reassembly process. Therefore, boresight process is always need to align reference axes between PNU and K-MLRS cage. However, this study has proposed the case alignment process that it enable to correspond to reference axes between ISA (Inertial Sensor Assembly) block and PNU case. So, improved alignment procedure enables to install PNU in the reassembly process without additional boresight process.

• 수산해양기술연구
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• 제50권2호
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• pp.202-213
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• 2014

The sea cucumber, Apostichopus japonicus, is becoming an important aquaculture species in China, Japan and Korea. The purpose of this study is to evaluate the biological performance of a tubular type of subsurface cage for sea cucumber grow-out by in-situ tests. The cage structure was constructed of PP (polypropylene) frames and PP tubes (${\phi}130mm{\times}24pieces$). A set of tests were conducted at a depth of 15 m near Seosaeng, Ulsan, Korea for 295 days (23 July, 2012 to 13 May, 2013). A total of 155 sea cucumbers were used and fed a mixed diet containing mud, mineral, wheat, fish meal, etc (3% of their body weight). At the end of the experiments, sea cucumber showed a higher survival rate in feed shelter (77.14%) rather than no feed shelter (64.71%). The specific growth rate (SGR) of sea cucumbers in feed condition (0.04% $day^{-1}$) was higher than that of no feed culture animals (-0.49% $day^{-1}$) during total experimental periods. The result was able to find a no significance difference in survival rate but a significance difference in SGR under feed and no feed treatments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1098-1100
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• 2005

This paper presents a position control system for a linear induction motor(LIM) with cage-type secondary using direct thrust control(DTC). Also it presents a virtual instrumentation(VI) system for LIMs performance monitoring. The VI is designed using the graphical programming language LabVIEW and is capable of performing measurement functions, including data acquisition, display, and analyses at the same time. This paper reports the LIM's responses of the thrust, current, speed, and flux measured by the proposed monitoring system.

• 조명전기설비학회논문지
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• 제29권7호
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• pp.38-46
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• 2015

This paper propose a variable parameter estimations for variable over current load of five-phase squirrel-cage induction motor(IM) to servo control system. In order to high performance control of AC motor using a field oriented control(FOC) and direct torque control(DTC) algorithm, there are required precise motor parameters for slip calculation, flux observer, controller gain, torque command of current components, rotor position, speed estimation, and so on. We are suggest a analyzed estimation results of the motor parameters that developing five-phase squirrel-cage IM have a stator of concentrated winding for experimental within variable over current load at rated input frequency. There are results of stator winding measurement, no-load test, locked-rotor test, variable over current load test, and estimated parameters of equivalent circuits using manufactured experimental apparatus by IEEE Standard Test Procedure for Polyphase Induction Motors and Generators 112-2004.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.44-48
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• 1994

The cutting process of cage motor rotor require high precision and good roughness. The surface roughness of cutting face is very important factor with effect on the magnetic flux density of cage motor rotor. The paper describes a cause of decrease in the cutting force and roughness on low temperature cooling tool by means of analysis on the mechanism of force system at cutting confition and experimental findings. The main results as compared with the room temperature cutting are as follow : 1) The cutting resistance decreased due to low temperature cooling tool. 2) The surface roughness decreased due to low temperature cooling tool.

• 전기학회논문지P
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• 제63권4호
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• pp.241-247
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• 2014

This paper propose a variable parameter estimations of five-phase squirrel-cage induction motor(IM) for speed control system. In order to high performance control of AC motor using a field oriented control(FOC) and direct torque control(DTC) algorithm, there are required precise motor parameters for slip calculation, flux observer, controller gain, rotor position, speed estimation, and so on. We are suggest a analyzed estimation results of the motor parameters that developing five-phase squirrel-cage IM have a stator of concentrated winding for experimental of variable input power frequency. There are results of stator winding test, no-load test, locked-rotor test, variable actual load test, and estimated parameters of equivalent circuits using manufactured experimental apparatus by IEEE Standard Test Procedure for Polyphase Induction Motors and Generators 112-2004.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.288-292
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• 2001

In this paper, a maximum power control of a low-cost and rugged cage-type induction generator system is proposed, where the machine-side PWM converter is used for maximum power generation and field excitation control, and the line-side PWM inverter is used for the dc link voltage control and source-side power factor control. Simulation results through Matlab Simulink have been demonstrated.