• 한국전기전자재료학회논문지
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• 제33권4호
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• pp.326-330
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• 2020

Small-scale production control systems for smart manufacturing are becoming increasingly necessary as the manufacturing industry seeks to maximize manufacturing efficiency as the demand for customized product production increases. Correspondingly, the development of an embedded system to realize this capability is becoming important. In this study, we developed an embedded system based on an open source system that is cheaper than a widely applied programmable logic controller (PLC)-based production control system that is easier to install, configure, and process than a conventional relay control panel. This embedded system is system is based on a low-power, high-performance Cortex M4 processor and can be applied to smart manufacturing. It is designed to improve the development environment and compatibility of existing PLCs, control small-scale production systems, and enable data collection through heterogeneous communication. The real-time response characteristics were confirmed through an operation test for input/output control and data collection, and it was confirmed that they can be used in industrial sites.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1534-1536
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• 2005

A DC-DC converter is being widely used for various household appliances and for industry applications. The DC-DC converter is powered from single battery, and the voltage is varied according to the purpose. In the vehicle, various accessories whose electric power is different are being used. Thus, plural number of DC-DC converter should be provided, so these situations bring complicated circuits, and accordingly, higher cost. Under such backgrounds, in this paper, we propose a novel buck-boost chopper circuit with simply configuration which can supply to two or more different output loads. The propose chewer circuit can control output voltages by controlling duty ratio by using typically two switching devices, which is composed by single boost-switch and single buck-switch. The output voltage can be controlled widely. A few modified circuits developed from the fundamental circuit are represented including the general multi-load circuit. And all this merits and appropriateness was proved by computer simulation and experience.

• Journal of Welding and Joining
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• 제25권4호
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• pp.72-78
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• 2007

Aluminized steel sheet is a material with excellent heat resistance, thermal reflection and corrosion resistance. It has wide applications, owing to its low cost and excellent performance, in the petrochemical industry, electric power and other energy conversion systems, etc and has attracted the attention of many investigators. But the welding of aluminized steel sheet has a problem of decreasing tensile-shear strength, caused by mixed Al in the weld. This study investigated behavior of Al and its structural properties to resolve this problem. Several analysis equipment(SEM, EDX, EPMA) were used to investigate Al element in the weld. Also microhardness tester and TEM equipment were used to find the intermetallic compound. As a result of this study, Al-rich zones existed in the weld and Fe-Al intermetallic compounds were found in these zones. At the same time, the weldability of aluminized stainless steel sheet was investigated and compared with that of aluminized steel sheet. Although there is a difference between the base metal of the low carbon steel and stainless steel, it is interpreted that a behavior of Al element in the weld is similar.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2012년도 춘계학술발표대회
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• pp.570-573
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• 2012

본 연구의 목적은 전력의 효율적인 사용과 전력-IT융합 산업의 활성화를 위하여 국내 전력-IT융합 산업을 분석하고 발전방안을 제시하는 것이다. 이를 위해 본 연구에서는 Van de Ven의 Social System Framework를 기반으로 하여 전력-IT융합 산업을 제도적 장치, 시장소비, 자원 확충 및 기업 활동 부문으로 구분하여 분석하였다. 또한 분석 결과의 검증 및 시사점 도출을 위하여 전력에너지 분야의 전문가들을 대상으로 설문을 실시하였다. 그 결과 IT기업의 에너지 산업 진출과 전력-IT융합 시장에 대한 정책적 지원이 활발하게 이루어지고 있는 것으로 평가되었다. 반면 대기업 위주의 시장 경쟁과 인력양성에 대한 지원 부족이 문제점으로 지적되었다. 본 연구는 Social System Framework의 분석 결과 평가에 있어 IT산업에 종사하고 있는 전문가의 의견을 반영하지 못한 한계점이 있으나, 전력-IT융합 산업을 학술적 프레임워크에 근거하여 분석하고 산업 전문가의 의견을 반영하였다는 데 그 의의가 있다.

• International journal of advanced smart convergence
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• 제10권4호
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• pp.59-65
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• 2021

Electricity contributes to the development of the economy. Therefore, forecasting electricity demand plays an important role in the development of the electricity industry in particular and the economy in general. This study aims to provide a precise model for long-term electricity demand forecast in the residential sector by using three independent variables include: Population, Electricity price, Average annual income per capita; and the dependent variable is yearly electricity consumption. Based on the support of Multiple variable regression, the proposed method established a model with variables that relate to the forecast by ignoring variables that do not affect lead to forecasting errors. The proposed forecasting model was validated using historical data from Vietnam in the period 2013 and 2020. To illustrate the application of the proposed methodology, we presents a five-year demand forecast for the residential sector in Vietnam. When demand forecasts are performed using the predicted variables, the R square value measures model fit is up to 99.6% and overall accuracy (MAPE) of around 0.92% is obtained over the period 2018-2020. The proposed model indicates the population's impact on total national electricity demand.

• Elastomers and Composites
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• 제54권2호
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• pp.135-141
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• 2019

Polyphenylene sulfide (PPS) was filled with glass fiber (GF), aramid fiber (AF), and solid lubricants to improve the mechanical properties and wear resistance. The addition of GF effectively enhanced the tensile strength, flexural modulus, and impact strength of PPS, while solid lubricants such as polytetrafluoroethylene (PTFE), molybdenum disulfide ($MoS_2$), and tungsten disulfide ($WS_2$) lowered the friction coefficients of the composites to below 0.3. The ball nut and motor pulley of the electric power steering (EPS) were manufactured using the PPS composites, and feasibility was ascertained thereafter by conducting the durability test. The composites filled with GF and AF showed high mechanical strength, but slip occurred at the interface between the pulley and belt while testing above $50^{\circ}C$. When small amounts of lubricants were added, the slip was no longer detected because of the suppression of friction heat. It is realized that the low friction as well as high mechanical properties is important to ensure the reliability of plastic pulleys.

• 유통과학연구
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• 제19권5호
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• pp.5-12
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• 2021

Purpose: Research on supply chain sustainability is important for exporters When the factor of sustainable development is considered by the businesses as well as governments of all countries. Research on supply chain sustainability is important for exporters. Sustainable supply chain management and supply chain dynamics will help enterprises adapt to changes in the business environment. This study analyzes the impact of sustainable supply chain management, and supply chain dynamic capabilities on the sustainable development of exporting enterprises in Vietnam. Research design, data, and methodology: The research model and survey are designed based on previous studies after surveying export enterprises. With 185 samples collected from export enterprises. The Structural Equation Modeling (SEM) analysis technique is used. Data analysis is performed on SPSS and AMOS software (Reliability test, Confirmatory Factor Analysis, SEM). Results: Sustainable supply chain management and supply chain dynamic capabilities all have positive effects on the sustainable development of businesses (sustainable development is measured by distribution: measuring economic efficiency, social efficiency, and environmental performance). Conclusions: From the results of this study, the authors also made several recommendations to help export enterprises develop sustainability based on sustainable supply chain management and supply chain dynamic capabilities.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.33-33
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• 2023

In this article, the challenges of Iran and the world are compared to the management of available water resources. Especially in recent years, according to the climatic changes that have occurred all over the world and the changes in the rainfall patterns, and the corresponding changes in the management of water resources, the situation in Iran is being investigated. According to the available information, the amount of water on the planet is estimated to be about 1.36 billion cubic kilometers, which covers about 71% of the earth's surface. However, about 97.5% of the water in the world is salty ocean water and only 2.5% is fresh. Therefore, only 0.025% of the total water on the planet will be usable. According to United Nations statistics, 61% of the world's water consumption is in agriculture, 23% in industry, and 8% for drinking, household, and health purposes. Considering the large number of dams in Iran, only 6% of all dams are used to produce electric energy, which is a significant difference compared to the world (approximately 19%).

• 한국건축시공학회지
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• 제10권4호
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• pp.75-82
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• 2010

건설산업이 대형화, 초고층화, 다양화되면서 우수한 기술과 Know-how가 요구되고 있고, 또한 건설기술자의 부족, 특수환경 하에서의 건설공사의 증가 및 구조물의 고성능화 등의 요구에 따라 콘크리트 분야 기술력을 개발하고 실용화하는 것이 필요하다. 이를 위하여 고성능 콘크리트에 대한 성능규정 및 기술개발에 많은 노력을 기울여 왔으며 한 가지 방안으로 신뢰성이 높은 고유동 콘크리트를 적용하면 시공의 제약조건을 극복할 수 있으며, 작업인원의 절감 및 공기단축의 효과를 얻을 수 있을 것으로 기대된다. 고유동 콘크리트를 현장에 적용하기 위해서 실제 건설현장에서 대용량의 배치플랜트에서 생산할 경우에도 시공성을 만족시킬 수 있는지를 평가하기 위하여 현장 모의시험을 실시하였다. 시험결과로부터 다성분계 고유동 콘크리트는 실제 구조물에서도 양호한 충전성능을 가진 것을 확인할 수 있었고, 수화열로 인한 콘크리트 내부온도 상승도 양호한 범위 값을 나타내었다. 향후 시공조건에 따라 전련산업관련 구조물 등에 유용하게 활용될 수 있을 것이다.

• 방사선산업학회지
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• 제17권1호
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• pp.19-32
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• 2023

The amount of radioactive waste is expected to dramatically increase with decommissioning of nuclear power plants such as Kori-1, the first nuclear power plant in South Korea. Accurate nuclide analysis is necessary to manage the radioactive wastes safely, but research on verification of radionuclide analysis has yet to be well established. This study aimed to develop the technology that can verify the results of radionuclide analysis based on artificial intelligence. In this study, we propose an anomaly detection algorithm for inspecting the analysis error of radionuclide. We used the data from 'Updated Scaling Factors in Low-Level Radwaste' (NP-5077) published by EPRI (Electric Power Research Institute), and resampling was performed using SMOTE (Synthetic Minority Oversampling Technique) algorithm to augment data. 149,676 augmented data with SMOTE algorithm was used to train the artificial neural networks (classification and anomaly detection networks). 324 NP-5077 report data verified the performance of networks. The anomaly detection algorithm of radionuclide analysis was divided into two modules that detect a case where radioactive waste was incorrectly classified or discriminate an abnormal data such as loss of data or incorrectly written data. The classification network was constructed using the fully connected layer, and the anomaly detection network was composed of the encoder and decoder. The latter was operated by loading the latent vector from the end layer of the classification network. This study conducted exploratory data analysis (i.e., statistics, histogram, correlation, covariance, PCA, k-mean clustering, DBSCAN). As a result of analyzing the data, it is complicated to distinguish the type of radioactive waste because data distribution overlapped each other. In spite of these complexities, our algorithm based on deep learning can distinguish abnormal data from normal data. Radionuclide analysis was verified using our anomaly detection algorithm, and meaningful results were obtained.