• 대한전기학회논문지:시스템및제어부문D
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• 제53권9호
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• pp.630-637
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• 2004

In this paper, we present a local reduced-order observer for a class of nonlinear systems that have full robust relative degree. The proposed observer utilizes the coordinate change which transforms a nonlinear system into an approximate normal form. The proposed reduce order observer is applied to a ball and beam system, and simulation results show that substantial improvement in the performance was achieved compared with the jacobian linearization observers.

• 융합신호처리학회 학술대회논문집
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• 한국신호처리시스템학회 2000년도 추계종합학술대회논문집
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• pp.193-196
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• 2000

ln this paper, we consider to apply of 2-DOF (Degree of Freedom) PID controller at D.C servo motor system. Many control system use I-PD, PIB control system. but the position control system have difficulty in controling variable load and changing parameter We propose neural network 2-DOF PID control system having feature for removal disturbrances and tracking function in the target value point.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2008년도 지능정보 및 응용 학술대회
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• pp.160-164
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• 2008

이러닝 문제은행 기반의 출제 시스템에서 평가를 위해 출제되는 문제들은 주로 난이도에 따른 자동 출제 방식을 이용하고 있다. 이러한 방식은 출제 시점의 문제 난이도가 문제 출제에 핵심이기 때문에 무엇보다 객관적이고 효율적인 방법으로 문제의 난이도에 대한 지속적인 관리가 필요하다. 본 논문에서는 웹 기반의 학습 시스템에서 보다 효율적인 문제 출제를 위해, 평가 결과를 바탕으로 해당 문제들의 난이도를 동적으로 재조정하는 보다 향상된 알고리즘을 제시한다. 제시된 알고리즘을 구축된 웹기반 학습 시스템에서 기존 알고리즘과 비교 분석해 본 결과 보다 효율적임을 확인할 수 있었다.

• Journal of Information Processing Systems
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• 제18권2호
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• pp.208-222
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• 2022

Through the analysis of the coordination mechanism of the supply chain system of China's automobile manufacturing industry, the factors affecting the supply subsystem, the manufacturing subsystem, the sales subsystem, and the consumption subsystem are sorted out, the supply chain coordination index system based on the influence factor of four subsystems is established. The evaluation models of the coordination degree in the subsystem of the supply chain, the coordination degree among the subsystems, and the comprehensive coordination degree are established by using the efficiency coefficient method and the collaborative entropy method. Experimental results verify the accuracy of the evaluation model using the empirical analysis of the collaborative evaluation index data of China's automobile manufacturing industry from 2000 to 2019. The supply chain synergy of automobile manufacturing industry was low from 2001 to 2005, and it increased to a certain extent from 2006 to 2008 with a small growth rate from 0.10 to 0.15. From 2009 to 2013, the supply chain synergy of automobile manufacturing industry increased rapidly from 0.24 to 0.49, and it also increased rapidly but fluctuated from 2014 to 2019, first rising from 0.68 to 0.84 then dropping to 0.71. These results provide reference for the development of China's automobile manufacturing supply chain system and scientific decision-making basis for the formulation of relevant policies of the automobile manufacturing industry.

• International journal of advanced smart convergence
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• 제11권2호
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• pp.153-162
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• 2022

The impact of the information technology industry on economic development is becoming increasingly important. In this study, we take China's provincial-level regions from 2015 to 2020 as the research object, comprehensively evaluates the level of their information technology systems by the entropy weight method, and then measures the coupling coordination relationship between the information technology system and the economic development system by the coupling coordination degree model. As a result, we found that the income of the information technology industry, the investment of talents and science research have the most important influence on the level of the information technology system. During the research period, with increasing values, the coupling degree of the two systems was at a high level. Affected by development strategies, diffusion effects and industrial relocation, the coupling degree in the central and western regions has shown a rapid growth trend. The coordination degree of the two systems is relatively low, and 83.9% of the provinces are in the medium-low coordination stage. The information technology industry has obviously promoted economic development. Besides, relevant policies should be introduced to effectively support and guide the high-quality development of the information technology industry and promote the high-level coordinated development of the two systems.

• 지식경영연구
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• 제7권2호
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• pp.69-96
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• 2006

The purpose of this study is to find success factors of knowledge management in Korean firms, confirm them empirically, and verify their relative importance in terms of company size and industry type. The major studies on the knowledge management were deliberately selected and interpretively analyzed to find the success factors of Korean firms. As a result of the analysis, five success factors(top management's will, evaluation reward, organizational culture, knowledge management system, organizational structure) have been found. The empirical researches to make certain whether the above five factors derived are actually true or not have been separately performed by using questionnaire method. Based on the data collected, it is found that all five factors are significant. The degree of relative importance among the success factors of knowledge management in Korean firms has been found as: (i)top management's will, (ii)organizational culture, (iii)evaluation-reward, (iv)knowledge management system, (v)organizational structure. In company size, large firm's degree of relative importance among the success factors are: (i)top management's will, (ii)organizational culture, (iii)evaluation-reward, (iv)knowledge management system, (v) organizational structure. And medium-small firm's degree of relative importance among the success factors of knowledge management in Korean firms has been found as: (i)top management's will, (ii)organizational culture, (iii) evaluation-reward, (iv)knowledge management system, (v)organizational structure. Finally, in type of industry, manufactural firm's degree of relative importance among the success factors of knowledge management in Korean firms has been found as: (i)top management's will, (ii)organizational culture, (iii)evaluation-reward, (iv)knowledge management system, (v)organizational structure. And non-manufactural firm's degree of relative importance among the success factors of knowledge management in Korean firms are: (i)top management's will, (ii)organizational culture, (iii)evaluation-reward, (iv)knowledge management system, (v)organizational structure.

• 펄프종이기술
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• 제44권2호
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• pp.18-28
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• 2012

This study was to develop a novel automatic system for measuring St$\ddot{o}$ckigt sizing degree and contact angle at a time. The conventional methods to measure sizing degree had serious problems in obtaining significant differences according to different dosages of a sizing agent, and moreover they disclosed unique limitation due to liquid types used and tester's subjectivity. However, the newly developed system could get reproducible results through total automation of all procedures including liquid dropping, image acquisition and measurement of both St$\ddot{o}$ckigt sizing degree and contact angle. For the St$\ddot{o}$ckigt sizing test, the automatic system could measure sizing degree with more definite differences according to different dosage of AKD, compared to the conventional method. For the contact angle test, the automatic system showed a similar trend to the conventional method but had smaller contact angles due to distortion of an image focus by a sheet curl than the conventional testing machine. The problem from the image out of focus due to specimen curl will be overcome with adopting a new specimen holder for the future system.

• 펄프종이기술
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• 제37권1호
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• pp.73-81
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• 2005

Stockigt sizing test, which is readily affected by individual tester's bias as well as testing conditions in recognizing red coloration, had to be modified to improve its reliability and reproducibility. The novel testing system with the automatic recognizing program of red coloration was developed with the auxiliary equipments including an automatic liquid dispenser and a specimen shifter. The analysis program used a hue value of a droplet image in recognizing a point of time on red coloration instead of RGB values that are not similar to human perception of color. Hue was more sensitive in recognizing the red coloration of a droplet than the other two factors, Saturation and Value. During the test, the program records the time consumed up to a specific hue value of a droplet on a specimen. Differently from the conventional test, the automatic test could obtain a reliable and reproducible sizing degree with a minor error. Furthermore, the Stockigt sizing degree measured by the automatic system showed great correlations with contact angle and Hercules sizing degree. It means that such great correlations will contribute to the development of an integrated measuring system capable of predicting contact angle, surface tension, surface energy and Hercules sizing degree of paper and paperboards through the Stbckigt sizing test. It was meaningful to note that the automatic system for Stbckigt sizing test might be able to used to predict contact angle, Hercules and Cobb sizing degree, based upon the high correlation coefficients.

• 한국가스학회지
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• 제16권3호
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• pp.42-47
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• 2012

본 논문에서는 규제 프레온냉매 R22의 대체 자연냉매의 후보인 R290(프로판), R600(부탄), R717(암모니아), R1270(프로필렌)을 작동유체로 사용하는 2단압축 1단팽창 냉동시스템의 성능 특성을 비교하였다. $-20^{\circ}C{\sim}-50^{\circ}C$ 정도의 저온을 얻기 위해 사용되는 2단압축 1단팽창 냉동장치에서의 증발온도, 응축온도, 과열도 및 과냉각도의 변화에 따른 성능계수(COP) 변화를 규명하고자 하였다. 성능특성 규명 결과, 과냉각도 및 중간냉각기에서의 냉매유량 증가에 따라 시스템의 COP는 증가하였으나, 증발온도, 응축온도 및 과열도가 증가할수록 COP는 저하되는 결과를 나타내었다. 또한, 자연냉매를 사용하는 2단압축 1단팽창 냉동시스템의 COP는 규제 프레온냉매 R22를 사용하는 경우보다 높기 때문에 자연냉매를 사용하고자 하는 냉동시스템의 안전성이 확보되면 충분히 대체 냉매로서의 경쟁력이 있을 것으로 판단되었다.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권4호
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• pp.189-197
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• 2003

The problem of designing a parallel feedforward compensator (PFC) is considered for a class of non-square linear systems such that the closed-loop system is strictly passive. If a given square system has (vector) relative degree one and is weakly minimum phase, the system can be rendered passive by a state feedback. However, when the system states are not always measurable and the given output is considered, passivation (i.e. rendering passive) of a non-minimum phase system or a system with high relative degree cannot be achieved by any other methodologies except by using a PFC. To passivate a non-square system we first determine a squaring gain matrix and design a PFC such that the composite system has relative degree one and is minimum phase. Then the system is rendered strictly passvie by a static output feedback law. Necessary and sufficient conditions for the existence of the PFC and the squaring gain matrix are given by the static output feedback formulation, which enables to utilize linear matrix inequality (LMI). As an application of the scheme, an alternative way of replacing the role of velocity measurements is provided for the PD-control law of a convey-crane system.