• Proceedings of the KIEE Conference
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• 2004.05b
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• pp.166-168
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• 2004

근래에 무인 자동화기술의 발달과 마이크로프로세서 기술의 혁신적인 성장에 힘입어 일반산업현장에서 사용되고 있는 로봇은 복잡하고 다양한 작업이 요구되는 비제조업분야로 그 적용분야가 확장되고 있다. 그 대표적인 분야를 들자면 방사능 지역과 같은 위험한 환경에서의 작업, 우주공간이나 심해에서의 작업, 활선 작업과 같이 사람이 접근하기 어려운 곳에서 인간을 대신하는 작업 등이 있다. 이와 같이 사람이 접근하기 어려운 지역에서 인간을 대신하여 작업을 수행할 수 있는 원격작업 로봇시스템을 개발하였다. 개발된 로봇은 6 자유도를 갖는 수평다관절 유압구동형 조작기로써 로봇의 운반 및 설치가 용이하도록 제 1 링크의 분리가 가능하도록 설계하였다. 로봇의 제어기는 전체 제어기를 통괄하는 1 개의 마스터 CPU 및 3 개의 제어보드로 구성되며 이들은 VME 버스를 이용하여 데이터를 전송한다. 로봇의 관리제어시스템은 그래픽워크스테이션을 이용하여 구성하였으며 로봇의 작업상황을 실시간으로 애니메이션하여 작업자에게 원격현장감을 제공하고 작업효율의 향상시켰다.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.169-171
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• 2020

지구온난화와 같은 환경적 문제점들로 인해 에너지 저감 및 고효율의 기술개발을 통한 탄소 저감이 주목을 받고 있다. 시대적 관심과 요구에 발맞춰 에너지 저감 효과가 있는 영구자석동기 전동기 등의 신기술을 철도차량에 적용하려는 연구가 활발히 진행되고 있다. PMSM을 철도차량에 적용하기 위해 추진제어장치는 인버터 한 대가 한 대의 전동기를 제어하는 1C1M 방식이어야 하며, 유지보수성과 안정성을 확보하기 위해 전동기와 인버터 사이를 전기적으로 분리해줄 수 있는 차단기가 필요하다. 또한 에너지 저감과 고효율을 달성하기 위해서 추진제어장치는 소형, 경량화 구조로 개발 되어야 한다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.5
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• pp.1223-1234
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• 2016

The Industrial control system is adopted by various industry field and national infrastructure, therefore if it received cyber attack, the serious security problems can be occured in the public sector. For this reason, security requirements of the industrial control system have been proposed, in accordance with the security guidelines of the electronic control system, and it is operated by separate from the external and the internal network. Nevertheless, cyber attack by malware (such as Stuxnet) targeting to control system have been occurred continuously, and also the real-time detection of untrusted traffic is very difficult because there are some difficulty of keeping up with quickly evolving the advent of new-variant malicious codes. In this paper, we propose the traffic analysis architecture for providing secure industrial control system based on the analyzed the security threats, the security requirements, and our proposed architecture.

• The Journal of the Acoustical Society of Korea
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• v.36 no.5
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• pp.353-360
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• 2017

The single sensor based acoustic reflection control system separates the incident and reflected signals from the single sensor output, and reduces the reflected signal by generating an out-of-phase signal from the incident signal component. In this paper, we propose an optimal filter design method for a single sensor based reflection control system. In the proposed method, it is shown that the optimum control filter design is possible by using the measured impulse responses of the reflection and control paths. The reflection control algorithm based on the proposed optimal filter achieves better performance than the conventional adaptive filter-based algorithm and effectively controls the reflection without the initial convergence time. We performed computer simulations using the signals obtained in a 1-dimensional acoustic duct environment, and from the simulation results, it was confirmed that the proposed optimal filter has robust performance even in noisy environment.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.6
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• pp.323-328
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• 2016

Pressurized membrane used for side-stream MBR process requires fouling control strategy both for normal and abnormal operation conditions for stable operation of the facilities. In this study, $85m^3/day$ of pilot-scale side-stream MBR process was constructed for the evaluation of fouling mitigation by air bubble injection into the membrane module. In addition, fouling phenomena at abnormal operation conditions of low influent and/or loading rate were also investigated. Injection of air bubble was found to be effective in delaying transmembrane pressure (TMP) increase mainly due to scouring effect on the membrane surface, resulting in expanded filtration cycle at a high flux of $40L/m^2{\cdot}h$ (LMH). At abnormal operation condition, injection of PACl (53 mg/L as Al) into the bioreactor showed 19% reduction of TMP increase. However, inhibition of nitrifying bacteria by continuous PACl injection was observed from batch experiments. In contrast, injection of powdered activated carbon (PAC, 0.6 g/L) was able to maintain the initial TMP of $0.2kg/cm^2$ for 5 days at the abnormal conditions. It may have been caused from the adsorption of extracellular polymeric substances (EPS), which was known to be excessively released during growth inhibition condition and act as the major foulants in MBR operations.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.403-404
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• 2008

자원의 고갈과 각종 환경규제 및 정부의 전력거래 방침 등으로 인해 점점 발전소에서는 전력 계통에 대한 신뢰도 및 전기품질을 유지하기가 어려워지고있다. 발전소의 부하대별 주요 운전 설계값은 효율과 바로 직결되는 사항으로 각 부하별로 온도와 압력 등 운전설계값을 최적의 상태로 유지하는 것은 발전소 수명과 발전효율, 전력거래 등에 있어 중요한 요소들이다. 전력시장에 진입하는 발전소는 전력계통의 갑작스런 불안성 상황이나 전력거래소 요청시 경사변동폭, 출력변통율, 무효전력 출력, 자동발전제어, 주파수조절량 확보 등을 수행할 수 있어야 한다. 본 논문에서는 고급공정제어기를 이용하여 운전설계계값을 효과적으로 제어 하면서 기존의 제어로직보다 전력계통상에서 요구되는 발전기 출력을 최대한 신속히 제어하는 과정을 기술하였다. 우선 보일러 마스터와 터빈 마스터, 급수 마스터로 구성된 제어로직을 설계한 뒤 이들 마스터에 대한 발전기 출력, 주증기 압력, 기수분리기 출구온도 각각의 영향을 모델링 기법을 이용하여 적합한 모델을 구했다. 각각의 모델을 고급공정제어기에 적용하고 발전기 출력제어에 대한 기존의 발전소 응답보다 좀 더 효율적이고 실제적용이 가능한 결과를 얻을 수 있도록 튜닝을 시행했으며 그 과정과 결과를 기술했다.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.5
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• pp.221-228
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• 2022

With the application of artificial intelligence technology, robots can provide efficient services in real life. Unlike industrial manipulators that do simple repetitive work, this study presented design methods of 6 degree of freedom robot arm and intelligent object search and movement methods for use alone or in collaboration with no place restrictions in the service robot field and verified performance. Using a depth camera and deep learning in the ROS environment of the embedded board included in the robot arm, the robot arm detects objects and moves to the object area through inverse kinematics analysis. In addition, when contacting an object, it was possible to accurately hold and move the object through the analysis of the force sensor value. To verify the performance of the manufactured robot arm, experiments were conducted on accurate positioning of objects through deep learning and image processing, motor control, and object separation, and finally robot arm was tested to separate various cups commonly used in cafes to check whether they actually operate.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.5
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• pp.19-26
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• 2014

Concrete guide rail and median barrier are an attached RC member, however they are vulnerable to cracking due to slip form construction and large surface of member. In this study, causes and pattern of cracking are analyzed through assessment and NDT (Non-Destructive Technique) evaluation for concrete guide rail and median barrier on highway structure. For this work, analysis on drying shrinkage and hydration heat are performed considering installation period, and plastic shrinkage is also analyzed considering their environmental conditions. From the evaluation, plastic settlement around steel location, drying/ plastic shrinkage, and aggregate segregation are inferred to be the main causes of cracking in the structures. The crack causes and patterns are schematized and techniques of crack-control are suggested. Furthermore concrete guide rail/ median barrier in the bridge on the sea are vulnerable to cracking at early age so that special attentions should be paid at the stages of material selection and construction.

• Journal of Korea Multimedia Society
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• v.9 no.4
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• pp.490-504
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• 2006

It needs to control each objects on various platform and transmit multimedia data to multiple receivers which are for developing a multimedia service with multimedia live streaming in a distributed environment. In this paper, we present a DLS (Distributed Live Streaming) package which support l:N multimedia live streaming in a distributed environment. Also, it has extended RMI which is a distributed object technology and JMF using multimedia transmission/processing. A java-based DLS package has been designed to separate a transmission and a control for more efficient distributed processing. It is possible to apply in development of multimedia service supported 1:N transmission and runned independently to any platform.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.5
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• pp.1447-1454
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• 1991

본 로봇은 wheeled type과 legged type의 장점을 함께 가지고 있으므로 주행 속도가 빠르며 환경적응력이 좋다. 기존 로봇과 비교할때 Y.Icihkawa등이 개발한 HLV와 가장 유사하지만 모터 3개로 6개의 바퀴-다리 유닛을 구동하므로 모터15개로 5개의 바퀴-다리유닛을 구동하는 Ichikawa HLV와 동력전달구조에서 많이 상이하다. 뿐만아니라 본 로봇은 3개의 모터만 사용했기 때문에 주행제어가 훨씬 간단하고 제작 비가 저렴하며 장애물 및 계단승강시 걸음새가 훨씬 간단하다.(Ichikawa HLV 경우 뒷 쪽 2개의 다리를 동시에 들 수 없기 때문에 계단 승강시 몸체 회전을 적절하게 섞어야 한다.)