• 한국철도학회논문집
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• 제9권4호
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• pp.455-460
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• 2006

본 논문에서는 자속 궤환을 포함하는 자기부상 시스템의 open-loop 특성에 대해서 다룬다. 훌륭한 외란 억제 특성을 포함하고 파라메타 변동에 대해서 둔감한 제어기를 설계하기 위해서 자속 궤환을 이용하는 것이 효과적일 수 있다. 적절한 센서에 의해서 측정 가능한 자속은 전류와 공극의 시간 변화에 대해서 선형적인 관계를 가지고 있으며, 자속의 궤한은 자기 부상시스템이 본질적으로 갖고 있는 전기적 엑츄에이터와 기계적 플랜트 사이의 간섭에 의해서 발생하는 비선형성을 감소시키는 역할을 한다. 모의시험 결과를 통해서 자속의 궤환이 자기부상 시스템의 부하변동에 대해서 Open-loop 성능 향상에 효과적임을 보인다.

• 한국전자파학회논문지
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• 제13권10호
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• pp.1078-1082
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• 2002

두 스텁이 커플된 마이크로스트립 계단 임피던스 저역통과 필터의 전송선로의 폭과 edge 캐패시턴스의 변화에 따른 삽입손실 특성을 연구하였다. 이 구조에서 커플링효과는 전송선로의 폭과 스텁의 갭 간격에 의존하며 적절한 조건에서 3개의 감쇄폴이 생겨 넓은 저지대역을 가진다. 또한, 두 스텁 사이에 존재하는 edge 캐패시턴스는 3개의 감쇄폴을 가지기 위해서 중요한 역할을 한다. 이것을 [S] 파라피터를 구하여 확인했다.

• World Technopolis Review
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• 제7권2호
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• pp.82-96
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• 2018

This paper discussed the application process of the Dot Idea program. The Dot Idea program is an incubation and open innovation program co-created by Unitec, an incubator at Tecnosinos Tech Park, and an SAP innovation team. The main objective of this study was to cover an existing gap in the literature regarding the practical application of an open innovation methodology. Many companies seek interaction with external parties to enable advancement toward identified innovation opportunities. Technology clusters, parks, and incubators have played an important role in promoting connections and interaction. Consequently, the Dot Idea program emerged as a result of a joint effort to create a program using a design science research methodology aiming to foster new businesses and strengthen Brazil and Latin America as a hub to develop new solutions for traditional organizations. In regards to lessons learned, the Dot.health trial had some success but also experienced difficulties; these related to the relationships between startups and a hospital's internal teams, and startups' needs to be funded from the beginning in order to be fully dedicated to a project.

• The Journal of Asian Finance, Economics and Business
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• 제6권3호
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• pp.163-172
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• 2019

The paper aims to investigate the impact of the gap between domestic and international gold price on money demand in Vietnam, an emerging economy in the Asian region. We use a quarterly database collected from the first quarter of 2004 to the fourth quarter of 2016. The time-series database includes 52 observations. The money demand is represented by M2; Domestic income is the Gross domestic product at the constant prices of 1994; Inflation rate is calculated by the Customer Price Index from the General Statistics Office of Vietnam. The result confirms the existence of a long-term cointegration relationship between the money demand and the gap between domestic and international gold price as well as some variables including domestic income, inflation, and real exchange rate. The regression results also show that the gap between domestic and international gold price has a positive impact on money demand in the Vietnamese economy. Besides, the domestic income and international gold price have positive impacts on money demand while the inflation and real exchange rate are negatively related in the long run. This proves that the gap between the domestic and international gold price really has a positive impact on money demand in Vietnam during the study period.

• Asian Journal of Business Environment
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• 제3권2호
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• pp.5-15
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• 2013

Purpose - This pilot study explores the gap between venture capitalists and young business graduates in Pakistan. Though the young graduates remain enthusiastic about choosing entrepreneurship as a profession, their success is subject to financial constraints. Research design, data, methodology - We administered a Likert-scale based questionnaire to 200 business graduates from June to July 2012, and interviewed ten venture capitalists from Islamabad and Lahore-two highly business oriented cities of Pakistan-to collect the data. The survey participation was on a voluntary basis without any financial sponsorship. Findings- There is a communication gap between the two parties (venture capitalists and business graduates), and a lack of trust in the entrepreneurial education and training offered in the educational institutions in Pakistan. The study, however, reveals the leading role of the Government in reducing this gap through certain measures. Conclusions - Some measures that can reduce the gap between venture capitalists and young graduates are: association of business schools with industry; financial institutions'initiatives to financially support the small and medium level projects of the economics and business students during their studies; establishment of placement bureaus in the business schools; and organization of regular open houses in the universities.

• 대한수학교육학회지:학교수학
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• 제13권2호
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• pp.245-266
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• 2011

본 연구에서는 초등학교 교사들을 대상으로 2007 개정 교육과정 3, 4학년 수학 교과서의 '열린 질문'에 대한 인식과 지도 실태를 설문조사 하였다. 그 결과, 교사들은 열린 질문의 취지에 대해서는 전반적으로 공감하고 있지만 교과서에 제시된 열린 질문과 그 지도상의 실제에 대해서는 교과서 열린 질문 자체, 교실 수업에서의 실행, 교사용 지도서와 교사연수 등에 걸쳐 여러 문제점을 인식하고 있다는 사실이 확인되었다. 본 연구에서는 이러한 조사 결과를 바탕으로 교과서 '열린 질문'의 개선 방향을 제안하였다.

• 유기물자원화
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• 제20권1호
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• pp.41-49
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• 2012

이형반응기 미생물연료전지(MFC) 시스템의 전기생산에 미치는 운전온도 및 전극간 거리의 영향에 관한 실험실 규모 실험을 수행하였다. 외부저항이 $(100\;{\Omega})$인 조건에서 시스템의 평균온도가 $30^{\circ}C$에서 $34^{\circ}C$로 증가할 때 외부저항 양단의 전압은 약 1.4배 증가하였다. 운전온도의 증가는 MFC의 OCV(open circuit voltage)를 증가시키며, 전극간 거리가 감소하고 운전온도가 증가함에 의해 최대전력이 얻어지는 전류가 상승하는 것으로 나타났다. MFC 시스템의 운전온도 증가에 의해 모든 전극간 거리조건에서 최대전력밀도가 크게 증가하였다. 시스템의 평균온도가 $4^{\circ}C$로 증가할 때 5~10 cm의 전극간 거리에서 얻어지는 최대전력밀도는 1.9~2.4배 증가하였고 동일한 온도조건에서는 전극간 거리가 감소할수록 전력수율이 증가하였다. MFC의 전기생산에 미치는 운전온도와 전극간 거리의 영향은 시스템의 내부저항과 밀접하게 관련되어 있는 것으로 나타났다. 즉, MFC의 운전온도가 증가하고 전극간 거리가 감소함에 의해 시스템의 내부저항이 감소함으로써 전기생산이 증가하였다.

• The Journal of Advanced Prosthodontics
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• 제2권1호
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• pp.25-31
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• 2010

PURPOSE. This study compared the accuracy of an abutment-framework (A-F) taken with open tray impression technique combining cement-on crown abutments, a metal framework and resin cement to closed tray and resin-splinted open tray impression techniques for the 3-implant definitive casts. The effect of angulation on the accuracy of these 3 techniques was also evaluated. MATERIAL AND METHODS. Three definitive casts, each with 3 linearly positioned implant analogs at relative angulations 0, 30, and 40 degrees, were fabricated with passively fitted corresponding reference frameworks. Ten impressions were made and poured, using each of the 3 techniques on each of the 3 definitive casts. To record the vertical gap between reference frameworks and analogs in duplicate casts, a light microscope with image processing was used. Data were analyzed by two-way analysis of variance and the Tukey test. RESULTS. The open tray techniques showed significantly smaller vertical gaps compare to closed tray technique (P < .05). The closed tray and the resin-splinted open tray technique showed significantly different vertical gaps according to the angulation of implant (P < .05), but the A-F impression technique did not (P > .05). CONCLUSION. The accuracy of the A-F impression technique was superior to that of conventional techniques, and was not affected by the angulation of the implants.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권6호
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• pp.342-350
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• 2003

In this paper, a levitation controller for a magnetic levitation(MagLev) system is designed and implemented. The target to be controlled is PEM(permanent and electromagnet) type with 4-corners levitation which is open-loop unstable, highly non-linear and time-varying system. The digital control system consists of a VME-based CPU board, AD board, PU board, 4-Quadrant chopper, and gap sensor, accelerometer as feedback sensors. In order to estimate the velocity of the magnet, we used 2nd-order state observer with acceleration and gap signal as input and output, respectively. Using the estimated states, a state feedback control law for the plant is designed and the feedback gains are selected by using the pole-placement method. The designed controller is experimentally validated by step-type gap reference change and force disturbance test.

• Journal of Ship and Ocean Technology
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• 제4권1호
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• pp.1-10
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• 2000

A low-order potential based boundary element method is applied for the prediction of the performance of flapped rudders as well as all-movable rudders in steady inflow. In order to obtain a reasonable solution at large angles of attack, the location of the trailing wake sheet is determined by aligning freely with the local flow. The effect of the wake sheet roll-up is also included with use of a high order panel method. The flow in the gap of a flapped rudder is modeled as Couette flow and its effect is introduced into the kinematic boundary conditions for flux at both the inlet and the outlet of the gap. In order to validate the present method, the method is applied for a series of rudders and the computational results on forces and moments are compared with experimental data. The effect of the gap size on the forces and moments is also presented.