• Annual Conference of KIPS
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• 2022.05a
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• pp.147-150
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• 2022

최근 들어 다양한 제약 조건이 있는 스마트 시티나 스마트 팩토리와 같은 도메인들 내에서 태스크들을 효과적으로 처리하기 위해서 MEC 기술이 많이 사용되고 있다. 그러나 이러한 도메인에서 발생하는 복잡하고 동적인 시나리오는 기존의 휴리스틱이나 메타 휴리스틱 기법을 이용하여 해결하기엔 계산 복잡도가 증가하는 문제점을 가지고 있다. 따라서 최근 들어 이러한 문제점을 해결하기 위한 방법 중 하나로 강화학습과 딥러닝이 결합된 DRL 기법이 주목을 받고 있다. 본 연구는 스마트 팩토리 환경에서 종속성을 가진 태스크들이 실행시간과 태스크가 처리되는 MEC 서버들의 로드 표준편차를 최소화하는 태스크 스케줄링 기법을 제안한다. 모의실험을 통하여 제안 기법은 태스크가 증가하는 동적인 환경에서도 좋은 성능을 보임을 증명하였다.

• Annual Conference of KIPS
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• 2023.05a
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• pp.644-646
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• 2023

스마트팩토리는 협동 로봇과 같은 프로그래머블한 설비의 유기적인 협업을 통해 최적화된 공정을 수행한다. 따라서 수집되는 센서 데이터의 특징과 환경 조건의 복잡도가 높아, 예지보전을 위한 AI 소프트웨어의 개발 시 요구사항 기반의 체계적인 개발 및 검증이 필수적이다. 본 논문에서는 AI 소프트웨어의 요구사항을 사용자와 시스템 관점에서 정의하고, AI 모델 개발 프로세스와 스마트팩토리 예지보전 측면에서 분석한다. 도출된 요구사항을 CNN 기반의 협동 로봇 기어 마모 예측 모델의 개발에 적용하여 데이터 관리와 모델 신뢰성 관점의 요구사항을 분석 및 검증하였다.

• Annual Conference of KIPS
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• 2023.05a
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• pp.187-189
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• 2023

IoT(Internet of Things), 빅데이터, AI(Artificial Intelligence), 클라우드와 같은 ICT(Information and Communications Technology) 기술이 발전함에 따라 ICT와 제조기술이 융합된 스마트팩토리가 발전하고 있다. 이는 2개의 영역과 5개의 계층으로 구성되어 기타 환경들과 상이한 구조를 가지고 있으며, 각 영역·계층별 발생 가능한 보안위협도 상이하다. 또한, 각 영역과 계층이 연결됨에 따라 발생 가능한 보안위협이 증가하고 있으며, 이에 대한 효율적인 대응을 위하여 스마트팩토리 영역·계층별 환경을 고려한 대응체계 마련이 필요한 실정이다. 따라서, 본 논문에서는 스마트팩토리 영역·계층별 발생 가능한 보안위협을 분석하고, 이에 대응하기 위한 대응체계 도출 기법을 제안한다.

• Annual Conference of KIPS
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• 2024.05a
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• pp.333-336
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• 2024

스마트팩토리는 기존 제조산업에 ICT 기술이 융합된 지능형 공장이다. 이는 IT(Information Technology)영역과 OT(Operation Technology)으로 구분되고, 영역 간 연결을 통해 제조공정 자동화 및 지능화를 수행한다. IT영역은 외부 네트워크와 연결되어 스마트팩토리의 전사업무 관리를 수행하며, OT영역은 폐쇄망 네트워크로 구성되어 직접적인 제조과정을 수행한다. 이는 2개의 영역으로 구분되어 자동화 및 지능화된 제조공정 과정을 수행함에 따라 구조가 복잡해지고 있으며, 이로 인해 스마트팩토리 보안위협이 발생 가능한 공격 표면이 증가하고 있다. 이에 대응하기 위해서는 스마트팩토리 IT영역과 OT영역의 특징을 분석하고, 영역별 적합한 보안위협 대응체계를 수립해야 한다. 이에 따라, 본 논문에서는 다수의 장치에 대한 학습이 용이하고, 세부적으로 학습기법을 구분할 수 있는 연합학습을 활용하여 스마트팩토리 영역별 적합한 보안위협 대응방안을 제안한다.

• Annual Conference of KIPS
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• 2007.05a
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• pp.267-270
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• 2007

효과적인 소프트웨어 프로세스 개선을 위해 SPICE와 CMMI 프로세스 심사 표준을 도입하려는 노력을 하고 있다. 이러한 표준을 통해 효과적인 개선하기 위해서는 개선점과 위험을 식별하고 이들 이슈들을 개발환경에 적용시켜서 조직의 비전에 대응한 작업성능을 높여야한다. 지속적인 개선을 필요로 하는 조직은 현재의 작업성능을 측정하고 이를 개선하기 위한 개선점을 찾아내는 능력과 경험을 축적하여 체계적으로 관리하는 것이 중요하다. 하지만 기존의 SPI 모델들은 무엇을 수행해야 하는지에 대한 지침은 제공하고 있지만, 정량적인 작업성능 측정 및 특정 환경의 소프트웨어 개발 조직의 SPI를 위해 필요한 구체적인 지침을 제시하고 있지는 않다. 따라서, 본 논문에서는 정량적인 SPI룰 위해 프로세스 측정 메트릭 정의와 심사 경험이 분석되어 활용될 수 있는 PCM(Process Capability Metric) Experience Factory 모델을 제안한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.34-47
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• 2018

As interest in advanced countries regarding the convergence technology development increases, a methodology for identifying the core convergence technology that has a large spill-over effect on the technology and industry is required for the nation's competitiveness enhancement in the convergence technology field. Based on patent citation network analysis using 1,124 USPTO patents in the ICT convergence technology field of the smart factory, this study examined the proposed heterogeneous technology convergence index as a tool for measuring the convergence characteristics of the spillovers compared to other indexes (i.e. other sector ratio index and homogeneous technology convergence index). The proposed heterogeneous technology convergence index was used to investigate core technology sectors among ICT technology sectors of smart factory identified by government ministries. Results found 6 core ICT convergence technology sectors including the manufacturing execution analysis application sector. Also, this study conducted blockmodeling analysis using the IPC codes of patents in the manufacturing execution analysis application sector, and identified that the blocks representing the electronic communication and electric digital data processing technology sectors (Block 3 & 4) are related technology sectors which can be converged with core technology. Based on the findings, the implications for the convergence technology development planning of the smart factory field are discussed.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.6
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• pp.185-199
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• 1994

This study has been performed to present a new automatic tool wear measurement by digital image processing. The purpose of this paper is to develop an automatic tool wear measuring system based on the image processing which can be applied to the quasi-real time measurement of the characteristics of insert tip in turning. Tool wear monitoring is one of the key-problems, for the development of control systems of modern unmanned factory which are not completely solved now. In oredr words at present complete qualitative and quantitative information on tool wear morphology is required, at least on the following aspects : flank wear, its dimensions and distribution on the maximum and mean values on VB pqrqmeter in the various zones of the wearland. crater wear, its main dimensions and values of KT parameters. This research has been performed to this technique made possible by designing a proper lighting system to the worn tool with following features : The flank wear is measured by observing the active cutting part from a proper direction and by lighting the wearland by a diffuser optic system. The crater wear is visualized by lighting the tool by a He-Ne gas laser system developed in this study. By means of this system it is research to evaluate classical parameters of tool wear and to have complete information about tool wear morphology.

• The Transactions of the Korea Information Processing Society
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• v.1 no.3
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• pp.357-366
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• 1994

The IEEE 802.4 token bus has been widely accepted as the standard for factory local area networks. The priority option of the 802.4 standard supports multiple classes of traffic by using a set of timers to control information exchange. The performance of the 802.4 priority mechanism in industrial real time control is examined. A timer assignment technique is presented for such applications. The timers are set to satisfy the worst case access delay requirements of real time control applications. Other applications that are not time constrainted can be supported simultaneously. In fact under certain conditions, such applications can also be guaranteed a minimum bandwidth allocation. Simulation results are used to evaluate the timer assignment and utililization.

• Publications of The Korean Astronomical Society
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• v.22 no.3
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• pp.63-73
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• 2007

In this paper, we introduce the performance test results of digital data processing system for KVN (Korean VLBI Network). The digital data processing system for KVN consists of DAS (Data Acquisition System) and high-speed recorder which called Mark5B system. DAS system performs the digitalization of analog radio signal through ADS-1000 gigabit sampler with 1 Gsps/2-bit and process the digital filtering of digital signal. Mark5B system records the output data of DFB (Digital Filter Bank) with about 1 Gbps. In this paper, we carried out the preliminary evaluation experiments of the KVN digital data processing system connected between DAS system and Mark5B with VSI (VLBI Standard Interface) interface which is designed for compatible in each VLBI system. We first performed all of the KVN digital data processing system connected by VSI interface in the world. In factory inspection phase, we found that the DAS system has a memory read/write error in DSM (Digital Spectrometer) by analyzing the recorded data in Mark5B system. We confirmed that the DSM memory error has been correctly solved by comparing DSM results with Mark5B results. The effectiveness of KVN digital data processing system has been verified through the preliminary experiments such as data transmission, recording with VSI interface connection and data analysis between DSM and Mark5B system. In future work, we will perform the real astronomical observation by using the KVN 21m radio telescopes so as to verify its stability and performance.

• Journal of Bio-Environment Control
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• v.22 no.2
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• pp.100-107
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• 2013

Unlike general microwave, QRD (Quadratic Residue Diffusor) Microwave used in this study is known as a new technology that enhances the sterilization effect with low power because it is possible to induce the average sterilization by changing wavelength phase difference. Therefore, basic research was conducted on the function that could sterilize culture media for plant factory by using environmentally friendly and low energy consuming QRD Microwave. The results are as follows: It was confirmed that there was no external deformation in the polyurethane foam and rock wool medium when changing the microwave level between 2 and 8 kW in different water content of culture media. However, PDA solid media at 2 kW were not dissolved in 60 and 180 seconds. All of the media were dissolved in other processing. There was little difference in the microwave irradiation level and surface temperature of the strain according to the processing time between Bacillus sp. and Burkholderia sp. In the sterility test according to the microwave irradiation level and processing time, it was confirmed that both Bacillus sp. and Burkholderia sp. grew in the microwave level 2 kW regardless of time. In the microwave level 6 kW, all experimental groups except the processing of Burkholderia sp. for 60 seconds were sterilized, and all of Bacillus sp. was killed in the all experimental groups. In the microwave level 8 kW, it was confirmed that both Bacillus sp. and Burkholderia sp. were sterilized regardless of time. The temperature in microwave-processed media after contaminating strains to each medium was maintained at more than 100 in polyurethane foam and rock wool medium after 60 seconds. In general, it was shown that it was possible to sterilize after 60 seconds. Therefore, it is considered that Bacillus sp. and Burkholderia sp. which are the biggest problems in the plant factory can be adequately sterilized by QRD Microwave used in this study.