• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권4호
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• pp.358-365
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• 2005

In induction machine drive without a speed sensor, the estimation of the motor flux and speed often becomes deteriorated at low speeds with low back EMF. Our analysis shows that, in addition to the state resistance variation, the estimated value of field orientation angle is often corrupted by accumulative errors from the integration of voltage variables at motor terminals that have low signal/noise ratio at low frequencies. A repetitive loop path of integration in the feedback can amplify this type of error, thus speeding up the degradation process. The control system runs into information starvation due to the loss of correct field orientation. The machine's spiral vectors are controlled only in a reduced dimension in this situation. A novel control scheme is developed to improve the control performance of motor's current, torque and speed at low frequencies. The scheme gains a full-dimensional vector control and is less sensitive to the combined effect of the error sources at the low frequencies. Experimental tests demonstrate promising performances are achievable even below 0.5 Hz.

• 디지털산업정보학회논문지
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• 제6권4호
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• pp.183-192
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• 2010

Digital communities' spaces have been very popular through communication contents provide entertainment and usability. Emoticons provide simply emotional expressions and intension, so they weakly convey a realistic sense as they are designed by 2D graphics. However, 3D Avatars presented by 3D Computer Graphics make users interesting because of delivering senses of reality and three-dimension and amuse users because of representing their characters. It is the purpose of this study to analyze design examples of emoticons and avatars applying to personal messengers and propose the development of them. In addition, this paper researches various characteristics of emoticons and avatars for web and mobile phones, and suggests a strategy to usefully and properly apply emoticons and avatars to design.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.164-164
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• 2000

This paper proposes a moving window technique that extracts lanes and vehicles using the images captured by a CCD camera equipped inside an automobile in real time. For the purpose, first of all the optimal size of moving window is determined based upon speed of the vehicle, road curvature, and camera parameters. Within the moving windows that are dynamically changing, lanes and vehicles are extracted, and the vehicles within the driving lanes are classified as obstacles. Assuming highway driving, there are two sorts of image-objects within the driving lanes: one is ground mark to show the limit speed or some information for driving, and the other is the vehicle as an obstacle. Using characteristics of three-dimension objects, a neural network can be trained to distinguish the vehicle from ground mark. When it is recognized as an obstacle, the distance from the camera to the front vehicle can be calculated with the aids of database that keeps the models of automobiles on the highway. The correctness of this measurement is verified through the experiments comparing with the radar and laser sensor data.

• 농촌계획
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• 제14권1호
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• pp.51-58
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• 2008

In 2007, Google has introduced a novel approach to model some cities from around the world by utilizing vast amount of information provided by internet users. They essentially built an efficient engine to collect and compile enormous stream of data that are necessary to reproduce fine details of a city. In this Letter, we propose an implementation of this novel approach to establish a Web-based visualization of rural landscape and scenery. We later demonstrate its feasibility by constructing a 3D model of Namsa-ri, Danseong-myeon, Sancheong-gun, Gyeongsangnam-do.

• 한국정밀공학회지
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• 제24권5호
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• pp.62-67
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• 2007

A simple dimension measuring method for the measurement of human bust has been developed using projection moire. The 3-D data of a human bust was calculated from the 2dimensional image information obtained by the stripe using projection moire. The creation of 3-D geometric shape by digitizing real objects has been widely investigated in reverse engineering(RE). This procedure generally consists of three basic steps: data capture, data alignment and model reconstruction. In order to achieve a complete model, multiple scans must be taken and aligned.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1995년도 춘계학술대회 논문집
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• pp.152-157
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• 1995

In Turning It is good selection of cutting condition and cutting tools that influence upon the accuracy of dimension manufacturing efficiency and extension of tool life. Among them especially the identification of cutting force due to the change of cutting conditions which exerts a great influence on the turning is very important. In this study the cutting resistance due to the change of cutting conditions was caculated by using the energy method and good agreement in shown between theoritical and experimental results which were tested for the cutting resistance at the cemented carbide cutting tools with workpieces of SM20C and SM 45C.

• 소음진동
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• 제10권6호
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• pp.941-948
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• 2000

Active noise control is an approach to reduce the noise by utilizing a secondary noise source that destructively interferes with the unwanted noise. In general, active noise control systems rely on multiple sensors to measure the unwanted noise field and the effect of the cancellation. This paper develops an approach that utilizes a single sensor. The noise field is modeled as a stochastic process, and an adaptive algorithm is used to adaptively estimate the parameters of the process. Based on these parameter estimates, a canceling signal is generated. Oppenheim assumed that transfer function characteristics from the canceling source to the error sensor is only a propagation delay. This paper proposes a modified Oppenheim algorithm by considering transfer characteristics of speaker-path-sensor This transfer characteristics is adaptively cancelled by the proposed adaptive modeling technique. Feasibility of the proposed method is proved by computer simulations with artificially generated random noises and sine wave noise. The details of the proposed architecture. and theoretical simulation of the noise cancellation system for three dimension enclosure are presented in the Paper.

• 한국언어정보학회:학술대회논문집
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• 한국언어정보학회 2007년도 정기학술대회
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• pp.136-145
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• 2007

This paper explains how we define and represent modality in E-HowNet. Following Lyons (1977, reviewed in Hsieh 2003, among others), we hold that modals express a speaker's opinion or attitude toward a proposition and hence have a pragmatic dimension and recognize five kinds of modal categories, i.e. epistemic, deontic, ability, volition and expectation modality. We then present a representational formalism that contains the three most basic components of modal meaning: modal category, positive or negative and strength. Such a formula can define not only modal words but also words that contain modal meanings and cope with co-compositions of modals and the negation construction.

• 한국국방경영분석학회지
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• 제29권1호
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• pp.76-87
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• 2003

This paper proposes that we need a simpler method for developing the Website strategy for public institutions. The research objectives are threefold: (1) A model that relates to the monitoring of Website strategy in the public sector is proposed. The model includes basic dimensions and a $2{\times}3$ matrix that is a simplified version of the Mohammed et dl.s Marketspace Matrix. (2) The model is tested empirically with a sample of 56 Websites selected from govemment agencies, military organizations and police stations in Korea. (3) The effect of dimension/factors on the innovation level is tested. A special attention is paid to online attracting that is important for public institutions which usually do not use offline advertising aggressively. Results from regression analyses show that main dimensions (Marketing Drivers and relationship Stages) and three factors (Basic Information, Support Information, and Participation) in the matrix are all significantly influential on the innovation level, but the Attracting is not. Colorful designs and attracting features of a homepage have not necessarily anything to do with innovation. This message can offer a good piece of advice for managers of Websites.

• 한국의류학회지
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• 제28권6호
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• pp.830-841
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• 2004

The necessity to understand shopping orientation is increasing. Yet, there has been few research that investigated the conceptual structure of clothing shopping orientation[CSO]. Therefore, the purpose of this study is to develop the conceptual structure of CSO. For that purpose, both documentary and empirical researches were conducted. The documentary research was conducted to develop a theoretical structure model as a basis for exploring the conceptual structure of CSO. The empirical research was conducted to identify and modify the theoretical model so as to develop a conceptual structure model. The data was analyzed using confirmatory factor analysis, exploratory factor analysis, and Pearson's correlation analysis. As a result, a conceptual structure model of CSO was developed. The model consisted of three hierarchical levels of dimensions; upper-dimensions, middle-dimensions and lower-dimensions. The upper-dimensions were composed of 'economic', 'hedonic', and 'convenient' dimensions. Each upper-dimension consisted of middle-dimensions and lower-dimensions. Confirmatory factor analysis was executed to assess the fitness and cross validity of the structure model.