• 유통과학연구
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• 제7권4호
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• pp.15-26
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• 2009

인터넷은 기업의 운영과 경쟁방식을 송두리째 바꾸어 놓고 있다. 특히, 화훼유통 서비스를 급격히 진화시켰을 뿐만 아니라, 화훼소매점간 경쟁방식 자체를 변화시켰고 IT 서비스 제공자간 경쟁도 치열해지고 있다. 본 연구는 화훼소매점이 IT 서비스를 통해 화훼유통 서비스의 비즈니스 측면과 정보기술 측면에서 어떻게 진화하고 대응했는지 살펴보고자 한다. 또한, IT 서비스 제공자 측면에서 IT 서비스 위치 선정을 TPS(Typhoon Positioning Strategy) 관점에서 살펴보고자 한다. IT 서비스 제공업자는 높은 IT 역량을 기반으로 서비스 위치가 고객의 핵심 비즈니스(core business)에 위치하고 솔루션 수준에서 제공해야 높은 비즈니스 가치를 창출할 수 있고 지속적인 서비스의 제공이 가능하게 된다. IT 서비스 위치화 전략인 Typhoon Positioning Strategy(TPS)는 화훼유통 서비스의 비즈니스 진화방향, IT 서비스 트렌드, 그리고 사용자의 IT역량 수준을 고려해서 Business Process-Service Model을 가지고 IT 서비스 위치를 선정해야 한다는 것을 말하고 있다. 즉, IT 서비스 제공자는 자사에 적합한 IT 서비스 위치를 선정함에 있어서 먼저 고객의 핵심 비즈니스를 파악하여 솔루션 수준에서 IT 서비스를 제공해야 한다. 물론 솔루션 사용자의 IT 역량을 고려한 서비스 수준도 고려해야 할 중요한 요소이다. TPS 관점에서 고려해야 할 원칙으로 4가지를 제시했다. 원칙1: 제공하는 IT 서비스의 Solution Map 보유, 원칙2: 제공하는 IT 서비스가 고객의 핵심비즈니스를 지원, 원칙3: 제공하는 IT 서비스는 단위기능 수준이 아닌 솔루션 수준, 그리고 원칙4: 사용자(즉, 화훼소매점)의 IT 역량을 고려한 차등화 서비스 제공 등이다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2524-2528
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• 2003

High-precision position system is widely used in lots of fields such as semiconductor industry, biotechnology, display and other up-to-date industry field. One of the main issues is to have a long traveling range with precision. There are a few solutions. For instance, there are inchworm methods, lever principle. In this study, we use lever principle to amplify output displacement with a new mechanical amplification structure. We designed new type 3DOF stage with PZT actuator and capacitive sensor. Non-monolithic structure is suggested to obtain the convenience of assembly and modification. Driving parts are designed as modules that generate displacement amplification of each axis. Designed motion module consists of 3 flexure hinges and a PZT actuator with double L lever structure.

• 대한기계학회논문집A
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• 제27권11호
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• pp.1941-1948
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• 2003

This paper is about feasibility study of positioning device using magnetic suspension system which uses only vertical magnetic forces. The proposed system has inherited advantages from contact-free system, simple structure, and high expansibility in operating range different from conventional positioning devices. In this paper, the structure and operating principle are described and the linearized magnetic force and dynamic model are obtained. With the linear control theory, the experiments are executed. finally, the experimental results are shown.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.2
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• pp.247-250
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• 2006

Based on the possibility theory and the fuzzy set, the Maximum Possibility Estimation method and its applications in kinematic GPS positioning are presented in this paper. Firstly, the principle and the optimal criterion of the Maximum Possibility Estimation method are explained. Secondly, the kinematic GPS positioning model of single epoch single frequency with baseline length constraint is developed. Then, the authors introduce the artificial immune algorithm and use this algorithm to search the global optimum of the Maximum Possibility Estimation model. The results of some examples show that the method is efficient for kinematic GPS positioning.

• 대한기계학회논문집A
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• 제30권6호
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• pp.622-630
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• 2006

This paper is about the magnetic suspension stage based on the Switched Reluctance propulsion principle. Because the previous studies on contact-free stage adopted the Lorentz force for main force generation mechanism they have suffered from thermal problem deteriorating the precision. Thus, the magnetic suspension stage adopting SR principle which can achieve high force density is proposed. The main operating principle and structure for achieving high resolution and long travel range are represented. The magnetic force analysis of each actuator, providing back data for dynamic modeling and controller design are carried out. By conducting basic experiments, the feasibility of the proposed system is shown. In addition the problems which should be improved and their solutions are represented.

• 대한공간정보학회지
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• 제24권2호
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• pp.25-35
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• 2016

Since a sophisticated location determination technology (LDT) is necessary for accurate positioning in urban area environments, numerous studies related to the LDT using the RFID (Radio Frequency IDentification) technology have been implemented for real-time positioning and data transferring. However, there are still lots of unsolved questions especially regarding what to use as base stations and what are corresponding results under the intrinsic complexity of alignment and configuration of components used for the RFID positioning. This study proposes the street light fixtures as base stations where the RFID receivers will be embedded for the mobile tracking scheme. As street light fixtures are usually installed at a certain distance interval, they can be used as base stations for the RFID receiver installation. Using the principle of the single row triangle network, the RFID receiver organization is determined based on the experiments such as recognition distance measurement and tag position accuracy estimation at inside and outside of the single row triangle network. The results verify that the mobile tracking scheme which uses RFID-embedded street light fixtures, suggested and configured in this study, is effective for the real-time outdoor positioning.

• 한국정밀공학회지
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• 제20권7호
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• pp.91-98
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• 2003

In the field of precision manufacturing demanding high positioning performance, the mechanical friction in positioning device deteriorates the quality of the product and increases the cost of production for positioning devices. Therefore, we propose a contract-free linear actuator using active magnetic bearing. The structure and operating principle of the proposed system are explained, and the magnetic forces are analyzed by magnetic circuit theory to design magnetic bearings and linear actuator. With the derived equation of motion, the stability is identified. Experimental results are presented to show the feasibility.

• Journal of Positioning, Navigation, and Timing
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• 제2권1호
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• pp.81-89
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• 2013

Many of the current visual odometry algorithms suffer from some extreme limitations such as requiring a high amount of computation time, complex algorithms, and not working in urban environments. In this paper, we present an approach that can solve all the above problems using a single camera. Using a planar motion assumption and Ackermann's principle of motion, we construct the vehicle's motion model as a circular planar motion (2DOF). Then, we adopt a 1-point method to improve the Ransac algorithm and the relative motion estimation. In the Ransac algorithm, we use a 1-point method to generate the hypothesis and then adopt the Levenberg-Marquardt method to minimize the geometric error function and verify inliers. In motion estimation, we combine the 1-point method with a simple least-square minimization solution to handle cases in which only a few feature points are present. The 1-point method is the key to speed up our visual odometry application to real-time systems. Finally, a Bundle Adjustment algorithm is adopted to refine the pose estimation. The results on real datasets in urban dynamic environments demonstrate the effectiveness of our proposed algorithm.

• Steel and Composite Structures
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• 제18권5호
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• pp.1197-1214
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• 2015

There is a great difference in mechanical behavior between design model one-time loading and step-by-step construction process. This paper presents practical computational methods for simulating the structural behavior of long-span rigid steel structures during construction processes. It introduces the positioning principle of node rectification for installation which is especially suitable for rigid long-span steel structures. Novel improved nonlinear analytical methods, known as element birth and death of node rectification, are introduced based on several calculating methods, as well as a forward iteration of node rectification method. These methods proposed in this paper can solve the problem of element's 'floating' and can be easily incorporated in commercial finite element software. These proposed methods were eventually implemented in the computer simulation and analysis of the main stadium for the Universiade Sports Center during the construction process. The optimum construction scheme of the structure is determined by the improved algorithm and the computational results matched well with the measured values in the project, thus indicating that the novel nonlinear time-varying analysis approach is effective construction simulation of complex rigid long-span steel structures and provides useful reference for future design and construction.

• 한국전자통신학회논문지
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• 제6권1호
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• pp.27-33
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• 2011

본 논문에서는 SGR(software-based Global Positioning System receiver)에서 GPS(Global Positioning System)의 자료처리과정을 분석하기 위해서, GPS 신호의 수신방법을 심도있게 분석했다. 그리고 이 처리과정을 Matlab를 사용해서 모의실험을 했다. 실험결과, 이 분석방법의 타당성을 찾을 수 있었고, 이 실험은 실제 환경조건에서와 일치함을 확인할 수 있었다. 또 SGR의 성능을 향상시키기 위해서는 수신기의 성능을 향상시켜야 한다는 사실을 확인 할 수 있었는데, 동조되는 최적의 주파수는 수십 Hertz내에서 위상을 비교해서 찾을 수 있었다.