• KSII Transactions on Internet and Information Systems (TIIS)
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• 제3권6호
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• pp.597-611
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• 2009

With the advent of ubiquitous computing society, many advanced technologies have enabled wireless sensor networks which consist of small sensor nodes. However, the sensor nodes have limited computing resources such as small size memory, low battery life, short transmission range, and low computational capabilities. Thus, decreasing energy consumption is one of the most significant issues in wireless sensor networks. In addition, numerous applications for wireless sensor networks are recently spreading to various fields (health-care, surveillance, location tracking, unmanned monitoring, nuclear reactor control, crop harvesting control, u-city, building automation etc.). For many of them, supporting security functionalities is an indispensable feature. Especially in case wireless sensor networks should provide a sufficient variety of security functions, sensor nodes are required to have more powerful performance and more energy demanding features. In other words, simultaneously providing security features and saving energy faces a trade-off problem. This paper presents a novel energy-efficient security architecture in an IEEE 802.15.4-based wireless sensor network called the Hybrid Adaptive Security (HAS) framework in order to resolve the trade off issue between security and energy. Moreover, we present a performance analysis based on the experimental results and a real implementation model in order to verify the proposed approach.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권8호
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• pp.3606-3629
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• 2018

The discovered high potential utility itemsets (HPUIs) have significant influence on a variety of areas, such as retail marketing, web click analysis, and biological gene analysis. Thus, in this paper, we propose an algorithm called HPUIM-QGA (Mining high potential utility itemsets based on a quantum genetic algorithm) to mine HPUIs over uncertain datasets based on a quantum genetic algorithm (QGA). The proposed algorithm not only can handle the problem of the non-downward closure property by developing an upper bound of the potential utility (UBPU) (which prunes the unpromising itemsets in the early stage) but can also handle the problem of combinatorial explosion by introducing a QGA, which finds optimal solutions quickly and needs to set only very few parameters. Furthermore, a pruning strategy has been designed to avoid the meaningless and redundant itemsets that are generated in the evolution process of the QGA. As proof of the HPUIM-QGA, a substantial number of experiments are performed on the runtime, memory usage, analysis of the discovered itemsets and the convergence on real-life and synthetic datasets. The results show that our proposed algorithm is reasonable and acceptable for mining meaningful HPUIs from uncertain datasets.

• 한국정보시스템학회지:정보시스템연구
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• 제20권3호
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• pp.257-277
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• 2011

The current study categorizes factors of smartphone into three, using KANO model: attractive factors which cause only product satisfaction, must-be factors for dissatisfaction, and one-dimensional factors for both. Based on it, it presents a new model for the effects that smartphone factors have on satisfaction or dissatisfaction. The purpose is to theoretically explain that smartphone factors on which companies and users place a high value can actually affect satisfaction or dissatisfaction. After choosing 15 factors out of 25 which had been selected through literature study, these were divided into attractive, must-be, and one-dimensional ones. 93 out of 109 questionnaires returned were used for analysis. After frequency analysis using SPSS were conducted on the surveys, the factors were grouped, based on KANO table. The grouping results are as follows. Attractive factors include 'expansion slots for external memory, battery desorption, brand awareness, mobile banking and internet telephony'. Must-be ones include 'multi-touch, information security, entertainment, information retrieval, location based service and SNS. Finally, 'screen visibility, size of internal memory, the amount of internal memory, battery life, and response to after-sales service' are classified as one-dimensional factors. A critical finding of this paper is that since the results are different depending on the operating system of smartphones, it must be taken into consideration in studies on smartphones. The wide and rapid spread of smartphones has changed people's lifestyle as well as business environment, which forces companies to compete with each other to adapt to the changed circumstances. In this competitive system, studies on smartphone factors of satisfaction and dissatisfaction are essential for firms to establish a new strategy. From this point of view, the present paper is expected to be a basic material for enterprises not only to develop goods and services that maximize customer satisfaction and minimize dissatisfaction, but also to establish the future business strategy.

• 한국컴퓨터정보학회논문지
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• 제22권12호
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• pp.131-136
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• 2017

PLM(Product Lifecycle Management) is an information management system that can integrate data, processes, business systems and human resources throughout the enterprise. BOM(Bills Of Material) is key data for designing, purchasing materials, manufacturing planning and management, which is basic for product development throughout the product life cycle. In this paper, we propose the efficient system to increase the data loading speed and the processing speed when using such large BOM data. We present the performance and usability of IMDG (In Memory Data Grid) for data processing when loading large amounts of data. In the UI, using the pure web grid of JavaScript instead of the existing data loading method can be improve performance of data managing.

• 반도체디스플레이기술학회지
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• 제20권3호
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• pp.184-188
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• 2021

In general, digital signage is a next-generation smart media that provides various information and advertisement services to many people indoors or outdoors using the Internet. Recently, digital signage is rapidly spreading in such a small indoor environment, that is, in an area closely related to daily life, for example, inside an elevator. However, in this kind of indoor environment where the stay time of persons is extremely limited, it would be not easy for them to keep advertisements in the user memory for a long time. In the digital signage display installed in an indoor environment, it is possible to think about the possibility for a function such as expanding the screen to a user's smartphone, which is now widely spread, to contain, store, and use the transmitted content. In this paper, we propose a method to extend the display of digital signage contents to personal smart phones with interaction function in such a limited environment. In order to make the system operation, the proposed system was verified by confirming the result of dual screen implementation in a smart phone through the prototype implementation of a digital signage system in an embedded Linux environment.

• 한국인터넷방송통신학회논문지
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• 제9권4호
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• pp.39-45
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• 2009

최근 무선 모바일 컴퓨팅 응용 기술과 휴대용 모바일 단말장치 개발 기술의 급속한 발전과 더불어, 요즈음 가장 각광을 받는 이 분야의 이슈는 무선 모바일 애드 혹 네트워크 환경에서의 온라인 게임의 설계에 관한 것이다. 모바일 컴퓨팅 환경에서의 온라인 게임은 이동 단말들이 갖는 제약들: 즉, 낮은 성능의 프로세서, 극히 제한적인 메모리 공간, 무선 기반의 적은 통신 대역폭과 한정된 배터리 파워 등의 제한으로 인해 본격 온라인 게임 개발에 많은 제약이 따른다. 따라서 지금까지의 대부분의 모바일 게임들은 온라인이나 멀티플레이 기능에 매우 제한적이다. 본 논문에서는 많은 제약을 갖는 이동 단말을 기반으로 모바일 컴퓨팅 환경에서 다수의 사용자들이 멀티플레이가 가능한 온라인 MMORPG를 설계하고 구현하였다. 제안한 온라인 게임은 Blutooth를 이용하여 국부적으로 무선 모바일 애드혹 네트워크를 클라이언트들 간에 일시적으로 구축하고 MMORPG 게임을 온라인으로 수행할 수 있도록 설계하였으며, 또한 이들 간의 멀티플레이를 지원한다.

• 사물인터넷융복합논문지
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• 제9권2호
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• pp.1-9
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• 2023

이 연구는 시각장애인들의 생활 편의성 증진을 위해 음성태그리더기의 사용성 평가를 통한 제품의 사용성 개선을 위한 목적으로 수행되었다. 사용성의 원칙과 시각장애인의 특수성을 고려한 평가 모형에 근거하여 19개의 평가 항목에 대한 지각된 사용성 평가가 실시되었다. 제안된 시스템의 베타 버전과 정식 버전에 대한 조사에 1번 이상 참여한 총 50명의 시각장애인이 분석 대상에 포함되었다. 비모수 통계방법을 사용하여 분석한 결과, 음성태그리더기의 안전성과 음성 및 음질, 음성정보의 정확성에 대해서는 비교적 만족한 편이었으나. 리더기의 크기 및 무게, 휴대와 보관의 편의성을 포함한 사용상의 효율성 측면에서는 낮은 평가를 받은 것으로 나타났다. 사용성 향상을 위해 제품 사용을 위한 절차가 보다 간소화될 필요가 있으며, 일반적으로 자주 사용하는 사물에 대한 태그는 사전에 입력을 시켜서 보급하는 것이 도움이 될 것으로 판단된다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제34권5호
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• pp.465-475
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• 2007

인터넷 이용의 확산과 함께 많은 사용자들이 자신의 일상을 글이나 사진, 만화와 같은 형태로 표현하여 과거의 기억을 반추하거나, 다른 사람과 공유하는 데 사용한다. 본 논문에서는 사용자의 일상 행동과 감정이 표현된 특이성 목록을 활용하여 다양한 만화를 생성함으로써 사용자의 기억이 쉽게 회상되고 공유될 수 있도록 하였다. 우선 각 특이성 별로 정의된 우선순위와 연관성을 바탕으로 중요 특이성을 선택하여 만화 시나리오를 구성하고, 생성된 시나리오를 스토리 온톨로지를 통해 보정한다. 다음 보정된 시나리오의 각 특이성과 만화 이미지 사이의 유사도를 계산하여, 각 특이성에 어울리는 만화 컷이 조합된다. 마지막으로 다양한 만화 생성을 위해 날씨, 야경, 과장, 애니메이션과 같은 효과들을 적용하였다. 생성된 만화의 다양성을 측정하기 위해 사용 시나리오와 사용성 평가를 통해 제안하는 방법을 평가하였다.