• Journal of Internet of Things and Convergence
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• v.9 no.2
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• pp.1-9
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• 2023

This study was conducted for the purpose of improving the usability of the product through the usability evaluation of the voice tag reader to improve the life convenience of the visually impaired. Perceived usability evaluation was conducted for 19 evaluation items based on the evaluation model considering the usability principle and the characteristics of the visually impaired. A total of 50 participants were included for the analysis. As a result of the perceived usability evaluation of the visually impaired, the safety of the voice tag reader, voice and sound quality, and accuracy of voice information were relatively satisfactory. It was found that the reader received a low evaluation in terms of efficiency in use, including the size and weight of the reader, and the convenience of carrying and storing. For the usability improvement, the procedure for using a product needs to be more simplified, and it would be helpful to input and supply tags for commonly used objects in advance.

• Journal of Korea Multimedia Society
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• v.14 no.7
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• pp.872-883
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• 2011

SVC is an emerging video coding standard as an extension of H.264/AVC. This standard uses inter prediction, intra prediction and a new inter-layer prediction to improve coding performance of enhancement layers. However, it has high computational complexity. In this paper, we propose an efficient intra prediction mode decision method in the spatial enhancement layer to reduce the computational complexity. The proposed method consists of two phases. In the first phase, Intra_BL mode is selected using the RD cost of Intra_BL in advance. We exploit the fact that the RD cost and prediction mode are similar to those of neighbor macroblocks. In the second phase, we predict the enhancement layer mode using correlation between intra mode of enhancement layer and that of the base layer. Experimental results show that the proposed method could save from 48.15% to 56.32% in encoding time while degradation in video quality is negligible.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.5
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• pp.155-162
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• 2014

We proposed a 2 level tree based cluster based routing protocol for mobile ad hoc networks. it is our crucial goal to establish improved clustering's structure in order to extend average node life-time and elevate the average packet delivery ratio. Because of insufficient wireless resources and energy, the method to form and manage clusters is useful for increasing network stability. but cluster-head fulfills roles as a host and a router in clustering protocol of Ad hoc networks environment. Therefore energy exhaustion of cluster-head causes communication interruption phenomenon. Effective management of cluster-head is key-point which determines the entire network performance. The scheme focuses on improving the performance the life time of the network and throughput through the management of cluster-heads and its neighbor nodes. In simulation, we demonstrated that it would obtain averagely better 17% performance than LS2RP.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.1
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• pp.102-109
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• 2009

This paper proposes the efficient method of CSMA during an idle duration in the time slot. The hybrid TDMA/CSMA protocol is the method that shares the medium efficiently. This improves the channel efficiency and throughput by using CSMA method during the idle TDMA time slot. In CSMA duration, many devices start to compete with each other. This causes a low throughput because of a long delay and a frequent collision. In order to improve this problem, the proposed method reduces the number of devices that compete in the CSMA duration. Because the number of competed device is reduced, this proposed algorithm reduces the delay and collision probability. This decrements of delay and collision probability improve the networks. The simulation results show that the proposed limitive CSMA methods outperform any methods of hybrid TDMA/CSMA protocol.

• Journal of Internet Computing and Services
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• v.11 no.1
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• pp.77-84
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• 2010

Children, who have a language disorder, have difficulty in expressing their reaction about stimulus of sound and vision. So it is very hard to grasp that they recognize external stimulus or not. For solving these problem, we can check response time and make them to choose stimulus by giving stimulus of sound and vision to them through Audio and Visual Stimulus and Reaction Meter System. Additionally, We can help them by improving response time by repeated study based on the results and making them to recognize and choose stimulus faster without aversion about external stimulus. It would make them not to feel uncomfortable and isolated because they are unfamiliar with external stimulus.

• Applied Chemistry for Engineering
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• v.32 no.1
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• pp.91-96
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• 2021

This study was conducted to improve the operating conditions of an adsorption tower filled with potassium impregnated activated carbon for high hydrogen sulfide capture capacity. Heat treatment modified the surface properties of activated carbon, and ultimately determined its adsorption capacity. The activated carbon doped with potassium showed 57 times more adsorption at room temperature than that of using the raw adsorbent. It is believed that uniform pore formation and strong bonding of the potassium on the surface of carbon contributed to the chemical and physical absorption of hydrogen sulfide. The SEM analysis on the surface structure of various commercial carbons showed that the modification of surface properties through the heat treatment generated the destruction of pore structures resulted in the decrease of the absorption performance. The pressure drop across the activated carbon bed was closely related with the grain size and shape. The optimum size of irregularly shaped activated carbon granules was 2~4 mesh indicating economical feasibility.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.3D
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• pp.247-258
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• 2012

This research evaluates the serviceability of ZigBee device that provides a potential technology to realizing the ubiquitous computing by improving the productivity and effectiveness in construction and data acquisition. Literature review was conducted in various application areas such as bridge monitoring, slope management, road management, highway traffic control. In addition characteristics and challenges in various wireless technologies are described to identify their adoptability to construction environment. Among them, ZigBee technology was selected to introduce the functionality on hardware, network, and security. Then, questionnaire survey was implemented by four different group, construction engineers, students, hardware developers, and researchers to explore the success and failure factors of ZigBee technology in construction area. The results proposes a guideline of the applicability of ZigBee technology in the area of serviceability, application area, considerations, and future direction. This paper would provide valuable information for future researches and technology development in designing the wireless sensor network applications.

• The Journal of Society for e-Business Studies
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• v.19 no.1
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• pp.43-61
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• 2014

This research is an application of game theory to developing the supplier selection and demand allocation mechanism, which are the essential and major research areas of supply chain planning and operation. In this research, the most popular and widely accepted mechanism, the progressive reverse auction is analyzed and compared with the other game theoretic approach, Kalai-Smorodinsky Bargaining Solution in the viewpoint of holistic efficiency of supply chain operation. To logically and exquisitely compare the efficiencies, a heuristic algorithm based on Genetic Algorithm is devised to find the other optimal demand allocation plan. A well known metric, profit-cost ratio, as well as profit functions for both suppliers and buyer has been designed for evaluating the overall profitability of supply chain. The experimental results with synthesis data and supply chain model which were made to mimic practical supply chain are illustrated and analyzed to show how the proposed approach can enhance the profitability of supply chain planning. Based on the result, it can be said that the proposed mechanism using bargainging solution mayguarantee the better profitability for the whole supply chin including both suppliers and buyer, even though quite small portion of buyer's profitability should be sacrified.

• Proceedings of the CALSEC Conference
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• 1998.10b
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• pp.447-456
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• 1998

ㆍ 전자상거래 소프트웨어 개발에 객체지향 방법론을 적용하여 소프트웨어의 유지보수성, 재사용성, 개발생산성 및 품질 향상 ㆍ 웹 기반 소프트웨어 기술을 적용하여 표준화된 사용자 인터페이스 설계기법을 활용 ㆍ 전자상거래와 관련된 각종 표준을 선택하고 응용하여 관련 데이터의 보관 및 유지, 문서 교환을 효율적으로 수행; 차후 별도의 소프트웨어에 대한 요구가 발생하더라도 필요한 데이터의 참조가 용이 ㆍ 전자상거래 소프트웨어를 위한 개발 프로세스를 제시함으로써, 프로세스 관리 및 개선이 용이(중략)

• Journal of Applied Reliability
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• v.14 no.4
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• pp.256-261
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• 2014

Solar cells are considered ideal as a clean energy to generate electricity. However, silicon-based photoelectric cells show some shortcomings in efficiency, cost and reliability. This has been a barrier to further commercialization. This paper shows how 40 Inventive Principles can be used in the research and development on the solar cells to improve efficiency, cost and reliability.