• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• 제2B권3호
• /
• pp.125-132
• /
• 2002

PMSMS (permanent magnet synchronous motors) are widely used in industrial applications and home appliances because of their high torque to inertia ratio, superior power density, and high efficiency. For high performance control, accurate informations about the rotor position is essential. Sensorless algorithms have lately been studied extensively due to the high cost of position sensors and their low reliability in harsh environments. A novel position sensorless speed control for PMSMs uses indirect flux estimation and is presented in this paper. Rotor position and angular velocity are estimated by the proposed indirect flux estimation. Linkage flux and magnetic field flux are calculated by the voltage equations and the measured phase current without any integration. Instead of linkage flux calculation with integral operation, indirect flux and differential magnetic field are used for the estimation of rotor position. A proper rejection technique fur current noise effect in the calculation of differential linkage flux is introduced. The proposed indirect flux detecting method is free from the integral rounding error and linkage flux drift problem, because differential linkage flux can be calculated without any integral operation. Furthermore, electrical parameters of the PMSM can be measured by the proposed TCM (time compression method) for soft starting and precise estimation of rotor position. The position estimator uses accurate electrical parameters that are obtained from the proposed TCM at starting strategy. In the operating region, a proper compensation method fur temperature effect can compensate fir the estimation error from the variation of electrical parameters. The proposed novel position sensorless speed control scheme is verified by the experimental results.

• 농촌지도와개발
• /
• 제23권2호
• /
• pp.181-193
• /
• 2016

농업연구와 지도의 연계는 농업인의 역량을 증진시키는데 있어서 매우 중요하다. 이 연구의 목적은 농업연구지도 분야의 핵심 담당자를 대상으로 면접을 통하여 가족농 육성을 위한 농업연구와 지도의 연계에 관한 방안을 도출하고자 하였다. 농촌지도의 방법, 내용 그리고 농촌연구의 내용 등과 관련한 현안들이 인터뷰를 통해 양적, 질적 자료를 수집하였다. 파라과이 농업기술전파의 구조적 문제점은 기술지원서비스, 신용 서비스, 농가 계획과 기본 인프라의 부족 등이었다. 더욱이 요구되는 농촌지도내용은 유기농업, 토양관리와 보전, 농업신용, 조직역량강화, 마케팅, 참여연구, 기술이전 장비와 인프라, 농업기계화였다.

• International Journal of Knowledge Content Development & Technology
• /
• 제13권1호
• /
• pp.111-130
• /
• 2023

There are the national science and technology standard classification system used in Korea, the classification according to the standard classification system for educational organization units, and the Korean standard education classification by the National Statistical Office. It is not suitable for calculation or evaluation, and classification is still mixed depending on the purpose of use. Therefore, in this study, the current status of academic standard classification, issues related to the standard classification system such as research foundation associations and research institutes, and issues related to the academic standard classification through the analysis of existing prior research issues, etc. As a result of the research, first, it is necessary to maintain and strengthen the linkage of the academic classification system, such as maintaining the linkage between the relevant departmental classification systems and strengthening the linkage with the relevant classification system, as a result of analysis of major issues in the academic standard classification system, and the systematic improvement cycle of the revision process and management system and settings are required.

• 지식경영연구
• /
• 제7권2호
• /
• pp.13-34
• /
• 2006

This paper is an exploratory study to analyze the flow of knowledge in science and technology in order to predict technology innovation. Here, we need to look into the characteristics of how knowledge is created in science, technology and industry to start with. Based on the characteristics we find, we have to understand the relationships between science, technology and industry, and construct a model to link them to each other for future empirical studies. In this study, we take a general view of the existing study results and theoretical models on the characteristics and linkage of scientific and technological knowledge. Moreover, we examine the preliminary framework to link science to technology to industry for further study on the knowledge flow of science and technology. Finally, we present the direction for future study by using the examined models and framework.

• 정보보호학회논문지
• /
• 제25권3호
• /
• pp.703-713
• /
• 2015

기존의 EMS/SCADA에서 제어시스템과 필드디바이스 간의 연계시스템은 데이터의 신뢰성을 높이기 위해서 외부 네트워크와의 망 분리를 통한 접근 통제를 하였지만 현재는 운영의 효율성 증대와 체계적 관리, 경제적 측면을 고려한 외부 망과의 연결 필요성이 증가하고 있는 추세이다. 이런 발전한 연계구간은 과거에 비해 더 많은 보안 취약점을 갖게 되었으며, EMS/SCADA 연계구간에서의 통신은 특별한 관리 방법이 필요하다. 본 논문에서는 국내 환경을 고려하여 EMS/SCADA 연계구간에서 주로 사용되는 시리얼 DNP3와 TCP/IP기반 DNP3를 적용한 보안성 평가 인증기술을 제시하였다. 제시하는 보안성 평가 인증기술은 자원 안전성 테스트와 악성 패킷 테스트 2가지 세부 평가로 나누어 안전성을 평가하며 각각의 보안 요구사항 및 평가방법을 도출하여 기존의 평가 인증 기술들과의 차별성을 제시하고자 하였다.

• 산업경영시스템학회지
• /
• 제46권spc호
• /
• pp.9-18
• /
• 2023

In the global manufacturing industry, digital transformation is emerging as an important issue for companies to improve productivity and strengthen industrial competitiveness. The government and shipbuilding companies drive research and development to attain advanced technologies through digital transformation for shipbuilding & offshore plants, one of Korea's representative manufacturing industries. Therefore, the digital transformation of the shipbuilding & offshore plant industry was defined using an input-output analysis model, and the economic interrelationships of industries linked to the digital transformation of the shipbuilding & offshore plant industry were analyzed. According to the analysis, the shipbuilding & offshore plant industry ranks second among all 34 industries regarding the forward linkage effect. The backward linkage effect was ranked 27th, making it a mid-demand industry with a robust forward linkage effect. In addition, the production-induced effect was 0.455, the value-added-induced effect was 0.174, and the employment-induced effect was 1.779 people per billion won. The contribution of this study is that it will provide the basis for establishing policies necessary to strengthen the competitiveness of the shipbuilding & offshore plant industry. Also, it will help analyze the economic effects of digital transformation in other manufacturing industries.

• 한국정보통신학회논문지
• /
• 제18권4호
• /
• pp.771-778
• /
• 2014

본 연구에서는 우리나라의 지식서비스 산업에 대한 생산유발, 부가가치유발, 고용유발 효과 및 전 후방연쇄효과를 추정하였다. 지식서비스 산업은 부가가치 및 고용 증대에는 크게 기여하고 있지만, 생산유발이나 전 후방연쇄효과는 매우 취약한 것으로 나타났다. 최근 정부는 지식서비스 산업으로부터 새로운 성장 동력을 찾고 있는데, 그 방향성은 지식서비스 산업의 생산성 향상이 되어야 한다는 사실이 본 연구를 통하여 입증되었다.

• STI Policy Review
• /
• 제9권1호
• /
• pp.77-98
• /
• 2018

In the past few decades, the importance of dynamics of University-Industry Linkage(UIL) in strengthening national and regional innovation competency and global competitiveness has been progressively more acknowledged. However, establishing an effective UIL for a better economic development is still a challenging endeavor in Ethiopia, particularly in Tigray region. This study is aimed at assessing the status of UIL and in order to achieve such aim it analyzed the determinants of firms' intensity of interaction with the Mekelle University (MU) and the effect of the intensity of interaction on the relevant firms' innovation performance. The findings of the study showed that the status of UIL between the firms and the university in Tigray region was at an infant stage. The study also found that firm size, firm age (startups) and government supports have had a significant effect on firms' intensity of interaction with the MU. However, the firms' intensity of interaction with the MU did not have any significant effect on the firms' innovation performance. In contrast, cooperation with customers, other groups and suppliers, firm size, firm age, and in-house R&D activities were found to have a significant effect on the firms' innovation performance. In conclusion, the acquisition of knowledge and technology from university does not have an important role in firms' innovation performance in the studied region. Consequently, the government should design effective strategies and assign responsible bodies to implement the strategies, create awareness, and organize both firms and university to meet and work together in order to enhance firms' innovation performance.

• 한국기술혁신학회:학술대회논문집
• /
• 한국기술혁신학회 2006년도 춘계학술대회
• /
• pp.291-305
• /
• 2006

• 한국농공학회논문집
• /
• 제57권5호
• /
• pp.101-111
• /
• 2015

Establishment of appropriate data in certain formats is essential for agricultural water cycle analysis, which involves complex interactions and uncertainties such as climate change, social & economic change, and watershed environmental change. The main objective of this study was to develop web-based Data processing and Model linkage Techniques for Agricultural Water-Resource analysis (AWR-DMT). The developed techniques consisted of database development, data processing technique, and model linkage technique. The watershed of this study was the upper Cheongmi stream and Geunsam-Ri. The database was constructed using MS SQL with data code, watershed characteristics, reservoir information, weather station information, meteorological data, processed data, hydrological data, and paddy field information. The AWR-DMT was developed using Python. Processing technique generated probable rainfall data using non-stationary frequency analysis and evapotranspiration data. Model linkage technique built input data for agricultural watershed models, such as the TANK and Agricultural Watershed Supply (AWS). This study might be considered to contribute to the development of intelligent watercycle analysis by developing data processing and model linkage techniques for agricultural water-resource analysis.