• Journal of the Institute of Convergence Signal Processing
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• v.5 no.3
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• pp.216-222
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• 2004

Frequency selective fading is a limiting factor for transmission rate and performance in high-speed multimedia communications. In this paper, we propose a turbo coded adaptive quadrature amplitude modulation (QAM) system for efficient high-speed transmission. By making use of a user-friendly simulation platform of SPW, the proposed turbo coded adaptive QAM system(TuAQAM) is developed and its performance is evaluated in terms of throughput and BER performance. Two channel models having delay spreads of 700ns and 1400ns are created for the simulations. It is shown that the proposed TuAQAM system provides a performance improvement of approximately 3dB and improved throughput for the channel model whose delay spread is 700ns. Similarly, a performance improvement is also achieved for the channel model whose delay spread is 1400ns.

• Journal of Biosystems Engineering
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• v.38 no.1
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• pp.1-8
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• 2013

Purpose: Path planning and tracking algorithms applicable to various agricultural operations, such as tillage, planting, and spraying, are needed to generate steering angles for auto-guidance tractors to track a point ahead on the path. An optimal coverage path algorithm can enable a vehicle to effectively travel across a field by following a sequence of parallel paths with fixed spacing. This study proposes a path generation and tracking algorithm for an auto-guided Korean tractor with a tillage implement that generates a path with C-type turns and follows the generated path in a paddy field. A mathematical model was developed to generate a waypoint path for a tractor in a field. This waypoint path generation model was based on minimum tractor turning radius, waypoint intervals and LBOs (Limit of Boundary Offsets). At each location, the steering angle was calculated by comparing the waypoint angle and heading angle of the tractor. A path following program was developed with Labview-CVI to automatically read the waypoints and generate steering angles for the tractor to proceed to the next waypoint. A feasibility test of the developed program for real-time path tracking was performed with a mobile platform traveling on flat ground. The test results showed that the developed algorithm generated the desired path and steering angles with acceptable accuracy.

• Journal of Broadcast Engineering
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• v.23 no.2
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• pp.253-260
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• 2018

Personalized media broadcasting services can produce their own broadcasting contents with a variety of creative themes if they have just a transmission platform and devices that can obtain videos and voices of producers without the existing expensive equipment. In this paper, we develop and implement a new broadcasting system by applying this service framework to events such as seminars or academic conferences. The devices can be installed at each conference rooms and the integrated system transmitted to users. They can watch via their multi-resolution screen, such as smart-phones, laptops, and tablet PCs. It has the advantage of being able to receive real-time streaming and VOD services as well as additional information related to the conference. It is expected to provide convenience by allowing attendees to access the information via their devices, thereby creating an impact on participation and the underlying technology for the future research.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.943-946
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• 2006

XML is the most widely used document format by advantage that self-contained for platform. So, currently the most used among other document format. but XML appeared new problem that memory and transmission. And that be used in environment a request restriction memory and fast transmission as like mobile field. Although discussion of XML binarization is going on progress. And fast Infoset configuration using XML Information Set is receiving attention that a way to lower file size of hold down a existing usage. In this paper, we designed of module using fast Infoset and PER among ASN.1 Encoding Rule for XML binarization. And we implementation of encoder constructed interlace by stage of translation from XML into binary XML.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.12
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• pp.2984-2994
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• 2013

The emergence of smart phones has brought about a revolution in introducing a computer into the palm of a hand, and this revolution has lead to a smart society that offers comfort and joy in life; however, some side effects including a smart phone syndrome have been identified on a wider and more varied scale compared with any other IT devices of the past. This paper deduced side effect types and key issues according to type focusing on risk factors in accordance with the purpose of the use of smart phones, and diagnosed social effects based on them. In addition, based on the diagnosed results, the study proposed solutions to minimize side effects in order to produce social understanding and sympathy concerning the desirable utilization of smart phones. The proposed solutions should be able to cope with visible and potential side effects systematically by helping people to utilize smart phones, which are a platform of creativity, cooperation, communications, and entertainments, in a desirable way.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.1
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• pp.32-38
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• 2013

Small mobile robots which use round wheels are suitable for driving on a flat surface, but it cannot climb the obstacle whose height is greater than the radius of wheels. As an alternative, legged-wheels have been proposed by many researchers due to its better climbing performance. However, driving and climbing performances have a trade-off relationship so that their driving performance should be sacrificed. In this study, in order to achieve both driving and climbing performances, a new transformable wheel was developed. The developed transformable wheel can have a round shape on a flat surface and change its shape into legged-wheel when it makes a contact with an obstacle. For design of the transformable wheel, the performance of legged-wheel was analyzed with respect to the number and curvature of the leg, and then the new transformable wheel was designed based on the analysis. Contrary to the existing transformable wheels that contain additional actuators for the transformation, the developed transformable wheel can be unfolded without any additional actuator. In this study, in order to validate the transformable wheel, a simple robot platform was fabricated. Consequently, it climbed the obstacle whose height is 2.6 times greater than the wheel radius.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.4788-4795
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• 2011

The purpose of this study is to present and review the possible effect of the learning paradigm shift from traditional method to ubiquitous learning, the societal issues that need to be address in order to design a new pedagogical platform trending from e-learning to m-learning and now the u-learning. That without the proper study of how learning environment may affect the learning process of an individual will lead to poor quality of education. This new era of learning environment offer a big opportunity for "anytime, anywhere" learning. Thus, Lifelong learning is at hand of everyone. Maximizing the benefit of new trend will be a great help and addressing the limitations will lead to quality education. The components that comprise the ubiquitous learning are also discussed together with the technologies that will make it possible. The research learning domains that are in progress which shows that the interest in pervasive or lifelong learning attracted the interest of many research institutions. The types of learning mode and learning modalities are also briefly discussed in this paper.

• Journal of Korea Multimedia Society
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• v.16 no.3
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• pp.302-308
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• 2013

In this research, we have explored personal authentication system through multimodal biometrics for mobile computing environment. We have selected face and speaker recognition for the implementation of multimodal biometrics system. For face recognition part, we detect the face with Modified Census Transform (MCT). Detected face is pre-processed through eye detection module based on k-means algorithm. Then we recognize the face with Principal Component Analysis (PCA) algorithm. For speaker recognition part, we extract features using the end-point of voice and the Mel Frequency Cepstral Coefficient (MFCC). Then we verify the speaker through Dynamic Time Warping (DTW) algorithm. Our proposed multimodal biometrics system shows improved verification rate through combining two different biometrics described above. We implement our proposed system based on Android environment using Galaxy S hoppin. Proposed system presents reduced false acceptance ratio (FAR) of 1.8% which shows improvement from single biometrics system using the face and the voice (presents 4.6% and 6.7% respectively).

• The Journal of Industrial Distribution & Business
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• v.10 no.10
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• pp.45-51
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• 2019

Purpose - The purpose of this study was to propose a win-win development plan for not only suppliers of delivery applications but also traditional market vendor companies and delivery riders by analyzing existing delivery models and presenting a new delivery model to enhance competitiveness of the traditional market using delivery apps. Research desgin, data, and methodology - Specifically, small retailers, such as traditional markets and supermarkets, presented a compromised delivery model that utilizes the platform of specialized delivery app service providers for order reception, and that the delivery is delivered by delivery systems jointly hired by Vendor companies, such as franchising companies. To validate the significance of the trade-off delivery model, a cost-benefit analysis was conducted by those involved in the delivery application. Results - From the perspective of suppliers of specialized delivery applications, it is analyzed that the use of specialized delivery applications in traditional markets will be a new market opportunity for service providers to achieve increased sales. It is expected that consumer choice and satisfaction will be increased as convenience and accessibility of traditional market businesses that were available only through direct visit from the user side of the delivery application will be expanded. From the standpoint of delivery application franchises, it is analyzed that they can seek to increase sales and increase customer service as well as ease labor cost burden due to joint employment of delivery riders. The delivery rider will be able to seek to improve customer service due to job security, wage stability, risk reduction and overheated competition due to direct employment. Conclusion - In conclusion, the compromised delivery model solved the problems raised in the preceding study conducted on delivery application suppliers, users, franchises, and riders to establish that it could be a strategic alternative to increasing sales and expanding detailed rights for the self-employed in the traditional market, which are experiencing difficulties in management. However, the adoption of a compromise delivery model requires social consensus from those involved in the delivery application and requires legal, institutional and policy support, which will require continued follow-up research on the delivery model in the future.

• The KIPS Transactions:PartC
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• v.18C no.4
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• pp.227-236
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• 2011

IPTV(Internet Protocol Television) is one of the typical businesses which are the convergence of Broadcast and Communication. It provides broadcasting service using IP networks. Recently, IPTV service is developed to Mobile IPTV or Open IPTV. Especially, Open IPTV uses open platform so not only service providers but also general users can provide contents to other users. Open IPTV system has many content providers, so existing security solution of IPTV cannot be adopted. In this paper, we suggest user authentication and key distribution mechanism on Open IPTV. Our proposed mechanism is based on Kerberos, so it can support distribution environment such as Open IPTV. We demonstrate that proposed mechanism can guarantee secure transmission of contents and reduce the delay of user authentication on Open IPTV system compared to other authentication mechanisms. We also compare our proposal and other mechanisms in various aspects, and analyze efficiency and safety of proposed mechanism. As a result, we insist that this mechanism satisfies the security requirements for IPTV.