• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.114.6-114
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• 2001

According to expansion of wireless communication system and mobile device, interest has been growing in personal navigation system integrated with wireless system. In portable consumer electronics, such as cellular phones, GPS and PDA, one of major design factors is the power consumption. Solutions of reducing the power dissipation are low voltage, low system clock power management and so on. This paper develops a GPS receiver based on the advanced power management algorithm that achieves very low average power consumption. Both RF and DSP chips are powered down and reactivated only when the position fixing is required. In order to run, the developed includes the RTC calibration function and the fast reacquisition function using XMC (eXtended Multiple Correlator) ...

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.6 no.3
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• pp.24-30
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• 2007

The FPCs(Flexible Printed Circuit) are currently used in several electronic products like digital cameras, cellular phones because of flexible material characteristics. Because the FPC is usually small size and flexible, only one FPC should not enter chip mounting process, instead, several FPCs are placed on the large rigid pallette and enter into the chip mounting process. Currently the job of mounting FPC on the pallette is carried by totally manual way. Thus, the goals of the research is develop the automatic machine of FPC mounting on pallette using vision alignment. Instead of using two cameras or using moving one camera, the proposed vision system with only one fixed camera is adopted. Moreover, the two picker heads which can handle two FPCs simultaneously are used to make process time shortened. The procedure of operation is firstly to measure alignment error of FPC, correct alignment errors, and finally mount well-aligned FPC on the pallette. The vision technology is used to measure alignment error accurately, and precision motion control is used in correcting errors and mounting FPC.

• Proceedings of the Korean Society for Quality Management Conference
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• 2010.04a
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• pp.291-309
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• 2010

Customer satisfaction is an ever-growing concern of management throughout the world. To find the way to increase customer satisfaction, we must understand customer requirements. Kano distinguishes between three types of product requirements(must-be, one-dimensional, attractive requirement) which influence customer satisfaction in different ways when met. Timko has developed customer satisfaction(CS) coefficient based on Kano model. The CS coefficient is indicative of how strongly a product feature may influence satisfaction. In this paper, potential customer satisfaction improvement(PCSI) index was developed using Kano model and CS coefficient. The PCSI index represents how much a product feature can increase the degree of customer satisfaction when the product feature is fully fulfilled. In order to explain the meaning of PCSI index, a case study for cellular phones is done. It is also discussed how to use the index strategically.

• Journal of Korean Society for Quality Management
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• v.38 no.2
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• pp.248-260
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• 2010

Customer satisfaction is an ever-growing concern of management throughout the world. To find the way to increase customer satisfaction, we must understand customer requirements. Kano distinguishes between three types of product requirements (;must-be, one-dimensional, attractive requirement) which influence customer satisfaction in different ways when met. Timko has developed customer satisfaction(CS) coefficient based on Kano model. The CS coefficient is indicative of how strongly a product feature may influence satisfaction. In this paper, potential customer satisfaction improvement(PCSI) index was proposed using Kano model and CS coefficient. The PCSI index represents how much a product feature can increase the degree of customer satisfaction when the product feature is fully fulfilled. In order to explain the meaning of PCSI index, a case study for cellular phones is done. It is also discussed how to use the index strategically.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.10
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• pp.446-451
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• 2006

In this paper, we propose an implementation of JPEG2000 codec on the ARM9 Processor which includes independent memory management facility. The codec and memory management facility together can control the encoding and the decoding process effectively within available memory area. Embedded appliances like cellular phones have very limited internal memory which can't be expanded easily. However, they should provide various applications and services using restricted memory resources. The proposed codec with memory management can provide image quality that is identical to the original image on embedded platform. The implemented codec has no memory conflict with other applications. It shows that the proposed codec can manage memory resources efficiently.

• The Journal of the Acoustical Society of Korea
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• v.18 no.6
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• pp.71-76
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• 1999

In digital cellular communication systems, tandem coding occurs in communications between mobile phones with different speech codecs, resulting in poor voice quality, high computational load, and long transmission delay. In this paper, voice packet conversion technique is proposed to solve the tandem coding problems, and packet conversion algorithm from 13kbps QCELP to 8kbps QCELP is developed. Simulations using various speech data show that the proposed packet conversion method produces voice quality which is equivalent to that by the conventional tandem coding method with shorter transmission delay using about 33% computational load.

• Journal of the Ergonomics Society of Korea
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• v.24 no.1
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• pp.19-26
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• 2005

Mobile internet access using such devices as PDAs and cellular phones becomes popular as mobile technologies grow. However, the characteristics of small screen devices such as small screen size and pen-based input cause many usability problems. In this study, a human factors experiment was conducted to identify the factors affecting the usability of information search on a PDA. Factors manipulated in the experiment included use of wheel equipment, scroll dimension, and screen orientation. Task completion time, error frequency, and subjective satisfaction level were measured. In addition, various users' behavioral patterns such as scanning routes and mainly used scrolling methods were analyzed. Scroll dimension has a significant effect on task completion time. Scroll equipment and screen orientation affect subjective satisfaction level. The results could be applied to designing information structure of web sites for mobile use by providing vertical scroll and using external scroll equipments.

• Journal of Industrial Technology
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• v.27 no.A
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• pp.131-139
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• 2007

The recent advance in wireless network technologies has enabled the streaming media service on the mobile devices such as PDAs and cellular phones. Since the wireless network has low bandwidth channels and mobile devices are actually composed of limited hardware specifications, the transcoding technology is needed to adapt streaming media to given mobile devices. Futhermore owing to the diversity of bandwidth in the wireless network by reason of mobile users' movements and environments, it is difficult to provide stable QoS. In this paper, the autonomic multimedia transcoding system is proposed in order for users to provide network adaptive QoS. Our proposed system is based on the estimation of available bandwidth in wireless network for seamless multimedia streaming service. The proposed system is designed and implemented for various mobile clients. In experiments, we evaluate its seamless multimedia streaming and the adaptation transcoding bit rate according to the changes of bandwidth in wireless network.

• Journal of Families and Better Life
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• v.24 no.6 s.84
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• pp.147-160
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• 2006

The perceived needs and purchase experiences of college students in regard to goods and services and the relationship between the two variables were investigated. Data on 387 college studentswere analyzed to test the level of their perceived needs and purchase experiences of 43 goods and services. Results showed that respondents perceived cellular phones, going to movies and plays, books, entertainment and alcohol, which had been regarded as optional goods in the past, as highly necessary for their daily lives. On the other hand, 5 items that had been purchased by the highest number of respondents were food at restaurants, beverages at cafes, alcohol, movies and plays, and on-line avatars. The level of perceived necessity and purchase experience were positively correlated in general, although there were a few exception.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.634-637
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• 2001

The proposed contactless charger employs a pair of neighboring printed circuit board windings as a contactless energy transfer device, thereby making it amenable to low-profile designs and suitable for applications to the portable telecommunication/computing electronics in which stringent requirements for height, space, and reliability have to be met. The performance of the proposed charger is confirmed with experiments on a prototype charger developed for cellular phones.