• 한국위성정보통신학회논문지
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• 제8권2호
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• pp.22-28
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• 2013

In this paper, new LBS (location based service) are proposed using conventional DMB (digital multimedia/mobile broadcasting) system. LBS applications are proposed that can be suitable for the subway and ground transportation based on S-DMB (satellite-DMB) and T-DMB (terrestrial-DMB) respectively. In the shaded area such as subway, the broadcasting signal transmitted from the satellite of S-DMB system should be retransmitted by the earth repeater called the gap filler and each gap filler has its own identification value called the gap filler ID which introduces the area in which the gap filler was installed. Therefore, the LBS can be implemented by using the gap filler ID of S-DMB on the subway in which the GPS (global positioning system) can't be received. Unlike the LBS on the subway, the combination of T-DMB and DGPS (differential GPS) will be introduced as a way for ground transportation. Generally, DGPS has been designed to compensate the position value calculated from the GPS signal so that positioning error of about 1 meter can be obtained by using DGPS information. T-DMB system transmitting DGPS signal will be expected to be commercial in Korea and, if using DGPS information transmitted through T-DMB network, LBS with more precise positioning than GPS alone can be implemented in the ground vehicles.

• 대한기계학회논문집A
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• 제33권10호
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• pp.1045-1053
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• 2009

Precision stages for 6-DOF positioning, actuated by PZT stacks, which are fed back by gap sensors and guided by flexure hinges, have enlarged their application territory in micro/nano manufacturing and measurement area. The precision stages inherently have such limitations as the nonlinearity between input and output in piezoelectric stacks, feedback signal noise in precision capacitive gap sensors and low material damping in precision kinematic linkages of mechanical flexures. To surmount these limitations, the precision stage is modeled with physics-based variables, which are identified by transient response correspondence, and a gain margin calculation algorithm using the Prandtl-Ishlinskii model and describing function is newly developed to assess system performance more precisely than linear controller design schemes. Based on such analyses, a precision positioning controller is designed. Excellent positioning accuracy with rapid settlement accomplished by the controller is shown in step responses of the closed-loop system.

• Journal of Positioning, Navigation, and Timing
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• 제10권1호
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• pp.55-66
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• 2021

In this paper, we propose a signal propagation modeling technique for generating a positioning fingerprint DB based on Long Term Evolution (LTE) signals. When a DB is created based on the location-based signal information collected in an urban area, gaps in the DB due to uncollected areas occur. The spatial interpolation method for filling the gaps has limitations. In addition, the existing gap filling technique through signal propagation modeling does not reflect the signal attenuation characteristics according to directions occurring in urban areas by considering only the signal attenuation characteristics according to distance. To solve this problem, this paper proposes a Deep Neural Network (DNN)-based signal propagation functionalization technique that considers distance and direction together. To verify the performance of this technique, an experiment was conducted in Seocho-gu, Seoul. Based on the acquired signals, signal propagation characteristics were modeled for each method, and Root Mean Squared Errors (RMSE) was calculated using the verification data to perform comparative analysis. As a result, it was shown that the proposed technique is improved by about 4.284 dBm compared to the existing signal propagation model. Through this, it can be confirmed that the DNN-based signal propagation model proposed in this paper is excellent in performance, and it is expected that the positioning performance will be improved based on the fingerprint DB generated through it.

• 한국조리학회지
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• 제9권1호
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• pp.1-21
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• 2003

Up to these days, hotels are assumed to compete each other. Due to the spread of high quality the hotel buffet restaurants have begun to face an intensive competition. Hotel Buffet Restaurant have become the more competitive along with fund, good price, service, quality food, and management know-how. It causes the hotel restaurants confront with management difficulties. In order to overcome the management difficulties, hotel buffet restaurants have to improve their marketing abilities and especially to improve their service quality. For this, it is necessary for hotel buffet restaurants to investigate how their service providers and receivers recognize their service quality. In this research, we examined the cognitive three types of cognitive gaps among customers, service providers, and managers both on the service quality and on the positioning of hotel buffet restaurants. Their cognitive gaps proved negatively correlated with hotel's performance. This research suggests the fellowing findings. Firstly, the competitiveness of hotel buffet restaurant depends on the accurate communication and consensus among managers, service providers, and customers. Secondly, using the information about cognitive gaps recognized, each hotel buffet restaurant should develop concrete marketing plans and strategies with a careful consideration about its current competitive position and management condition.

• 한국통신학회논문지
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• 제36권1B호
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• pp.60-70
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• 2011

IPTV는 2010년 초반 가입자가 200만 명을 넘어서는 등 빠른 성장세를 보이고 있다. 그러나 이러한 성장세의 지속 여부에 의문이 제기되고 있다. 이러한 의문은 IPTV 성장의 주요 기반에 서비스 자체의 경쟁력에 있느냐 하는 점과 2010년 들어 가입자 증가 속도가 둔화되고 있으며, 가입자 수의 증가에도 불구하고 IPTV 사업자들이 수익을 내지 못하고 있는 점 등 때문에 제기되었다. 이러한 현상은 현재의 IPTV 서비스가 시장에서 요구하는 적절한 서비스 위치를 확보하지 못하였기 때문에 발생한다. 본 연구는 이러한 문제점을 해결하기 위해, 케이블 TV 가입자들의 IPTV로의 전환 요인이 무엇인지를 밝혀내어 소비자들이 인식하고 있는 IPTV 만의 서비스 가치가 무엇인지를 분석한다. 그리고 이러한 전환 요인 중 모바일 IPTV 비즈니스 모델 구성시 반드시 고려해야 할 요인이 무엇인지를 분석한다. 또한 모바일 IPTV서비스로부터 소비자들이 획득하고자 하는 가치와 IPTV서비스 제공과 관련된 사업자 등이 제공하고자 하는 서비스 가치 간에 어떠한 차이가 있는지를 밝혀, 모바일 IPTV 서비스 제공시 소비자 가치에 부합되는 서비스를 제공하기 위한 전략적 요인들을 제시하고자 한다.

• 패션비즈니스
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• 제6권4호
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• pp.1-16
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• 2002

The purpose of this study is to investigate any differences in perception of fashion brand positioning between a manufacturer and a consumer. So this can provide theoretical suggestions for the development of brand positioning strategy for fashion brand. For this study, three brands, (MINE, TELEGRAPH, and MICHAA,) were selected by the criteria. The data were collected via a selfadministered questionnaire and analysed by the statistical method. The results of investigation were as follows: 1. The consumers had good attitudes in the order following: MINE, MICHAA, and TELEGRAPH in the factors1). In the case of purchasing the goods, the result of the research showed presented that the consumer had better attitudes than in the case of unpurchasing the goods. Contrary to our expectation, TELEGRAPH has the best attitude in personality, one of the factors. 2. In the image positioning map between the manufacturer and the consumer, the consumer had the same perception about the manufacturer. However, there is a gap on the degree of agreement for positioning map. In the case of purchasing the goods, the result of the research represents that the consumers are similar to the manufacturer in perception of the image positioning. 3. In the results of forming attitudes and recognizing brand by the consumer, there is a difference in brand positioning. The display and the shop appearance are very important means of attractions very to the consumers but salesmen‘s service or direct mail (DM) do not appeal to the consumer.

• 소음진동
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• 제5권1호
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• pp.49-57
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• 1995

An electronic circuit device is developed such that the displacement between an electromagnet and a moving target can be estimated from the coil current measurement, and then applied to an active magnetic bearing system. In order to levitate the shaft without using displacement sensor the stable control gains are obtained from the linearized model which includes the gap estimation circuit. Experimental results show that the shaft, by the estimated gap feedback, can be levitated within $\pm$6 ${\mu}m$ positioning error.

• 한국정밀공학회지
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• 제15권11호
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• pp.199-207
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• 1998

This paper presents the design and the control of three degree-of-freedom(DOF) fine positioning device based on an electro-magnetic force. The device is designed by use of a magnetic circuit theory and it is capable of fine motion due to the electro-magnetic force. The device consists of permanent magnets, yokes and coils. The magnetic fluxes generated from the permanent magnets constitute magnetic paths through steel, whereas the coils are arranged into the gap between two surfaces of the yokes. Therefore, by supplying current to the coils, the coils are capable of some motions due to Lorentz forces. For the optimal design of the actuating system, the system parameters are defined and investigated under the given constraints. From the system modeling in small displacement, three decoupled equations of motion are obtained. To get better performance of the system, a PID controller is implemented. Experimental results are presented in terms of time response and accuracy.

• Journal of Positioning, Navigation, and Timing
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• 제5권2호
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• pp.47-57
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• 2016

Since the Global Navigation Satellite System (GNSS) may not provide navigation information due to external interferences, many countries have plans to prepare a backup system for this situation. One of the possible GNSS backup systems is a multiple radio positioning integration system in combination with the terrestrial radio navigation system. Before constructing such a GNSS backup system, M&S software is needed to analyze if the system satisfies the performance the required navigation performance. This study presents requirements of M&S software for coverage analysis of the navigation system, and proposes an M&S software design scheme on the basis of the requirements. The M&S software is implemented, and coverage analysis is performed to verify the validity of the proposed design scheme.

• Asia Marketing Journal
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• 제14권4호
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• pp.1-22
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• 2013

A growing gap between market needs and the capabilities of the enterprise prompts repositioning (Corstjens and Dolye 1989). This article examines the strategic repositioning of 'Korando Sports' undertaken by SYMC throughout the period from Jan. 2012 to Jun. 2012, to boost sales volume and market share by entering market of active-lifestyle consumers currently occupied by SUVs. SYMC's experience indicates that it is essential to close the gap between the market needs and the ability of the enterprise to make a shift to new consumer segment with a new positioning. The successful repositioning framework(Ryan et al. 2007) were employed in this paper. This framework is comprised of six elements: core strategic values, strategic flexibility/learning capabilities, customer awareness and sensitivity, external orientation, management commitment, and belief in the product and brand. The evaluation based on the successful framework also confirms that 'Korando Sports' case meets all the requirements of the successful strategic repositioning. This paper provides some of the managerial implications with aim of assisting executives in identifying strategic repositioning opportunities. Primarily, the 'Korando Sports' case affirms the repositioning as a viable strategy and indicates that repositioning is a feasible means for strategic change. Second, this case shows the influence of a target consumer and SYMC's repositioning to follow consumer preference for a particular attribute. Moreover, we can understand how a product formerly considered weak in attributes can enjoy benefits in other segments with the same attributes.