• 수면정신생리
• /
• 제27권1호
• /
• pp.1-7
• /
• 2020

Mobile digital devices are very familiar and useful devices in the daily life of modern people, and are used for various tasks such as communication, reading, writing, and playing media. As the use of mobile digital devices has become more prevalent, user time has also been increasing. In particular, the number of people who use digital devices before sleep is growing. The light pollution associated with these devices is classified into four categories: urban sky glow, glare, light trespass, and clutter. The pattern in which modern people use digital devices corresponds to light pollution caused by light trespass and clutter from light exposure to artificial light at night. The light pollution caused by digital devices can cause melatonin secretion suppression, delayed sleep onset, reduction of sleepiness before bedtime, and periodic rhythm and cognitive function disturbances. In addition, a study of children and adolescents showed there may be disturbances in the sleep-wake cycle and circadian rhythm, deterioration of sleep quality, and daytime fatigue due to light pollution caused by artificial light at night from mobile digital devices. A multi-faceted research effort is also necessary to investigate the healthy use of mobile digital devices based on research evidence and insights with an accurate evaluation of the influence of mobile digital devices as a form of light pollution.

• 한국정보통신학회논문지
• /
• 제19권11호
• /
• pp.2671-2676
• /
• 2015

오늘날, 모바일 장치는 현재 응용 프로그램의 넓은 범위를 지원 할 수 있습니다. 불행히도, 일부 응용 프로그램은 늘어나는 계산 능력을 필요로 하고 모바일 장치는 이러한 낮은 처리 능력, 제한된 메모리, 예측할 수없는 연결 및 제한된 배터리 수명으로 제약에 자원이 한정되어 있습니다. 모바일 장치의 한계를 극복하기 위해 연구자들은 강력한 컴퓨팅 인프라 모바일 장치에서의 작업 부하를 이동하기 위해 가상화 기술을 사용하여 모바일 장치에 클라우드 컴퓨팅 서비스를 확장하는 상상합니다. 이러한 기술은 인프라 자원이 풍부한 클라우드 또는 서버에 모바일 장치에서 자원을 많이 소비하는 계산의 이행으로 구성되어 있습니다. 본 논문에서 클라우드 아키텍처 기능에 클라우드과 모바일 장치 사이의 거리의 영향을 분석합니다.

• ETRI Journal
• /
• 제30권6호
• /
• pp.757-764
• /
• 2008

In this paper, we present a design evaluation system with visualization and interaction of mobile devices using virtual-reality-based prototypes which can be used to easily change design parameters and simulate embedded software. To evaluate and predict affective-engineering-based design preferences for mobile devices under a virtual environment, we have developed a high quality visualization platform which creates images that look similar to real mobile devices in addition to real-time simulation of realistic motions and functions of mobile devices. To support a quantitative usability test scenario for external design shape, we also have built a system which consists of a mixed-reality-based testing platform for measuring hand load.

• Journal of Advanced Marine Engineering and Technology
• /
• 제33권4호
• /
• pp.569-577
• /
• 2009

Mobile information retrieval is an evolving branch of information retrieval that is centered on mobile and ubiquitous environments. In general, mobile devices are characterized by lightweight, low power, small memory, small display, limited input/output, low bandwidth, and so on. Some of these characteristics make it impossible to apply general information retrieval to mobile environments without any modification. In order to relieve this problem, we design and implement an information retrieval system for mobile devices like wireless phones, PDA and handheld devices. We use document summarization techniques to alleviate the limitation of small display and user profiles to retrieve the most proper documents for each individual user for personalized search. Futhermore we use meta-search to lighten some burdens visiting several portal sites. In this paper, we have implemented and demonstrated the proposed mobile information retrieval system on the domain of travel and received good evaluation from users subjectively.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제11권7호
• /
• pp.3413-3430
• /
• 2017

With the fast increasing popularity of mobile services, ubiquitous mobile devices with enhanced sensing capabilities collect and share local information towards a common goal. The recent Mobile Crowd Sensing (MCS) paradigm enables a broad range of mobile applications and undoubtedly revolutionizes many sectors of our life. A critical challenge for the MCS paradigm is to induce mobile devices to be workers providing sensing services. In this study, we examine the problem of sensing task assignment to maximize the overall performance in MCS system while ensuring reciprocal advantages among mobile devices. Based on the overlapping coalition game model, we propose a novel workload determination scheme for each individual device. The proposed scheme can effectively decompose the complex optimization problem and obtains an effective solution using the interactive learning process. Finally, we have conducted extensive simulations, and the results demonstrate that the proposed scheme achieves a fair tradeoff solution between the MCS performance and the profit of individual devices.

• 한국HCI학회논문지
• /
• 제11권1호
• /
• pp.29-38
• /
• 2016

모바일 투어 가이드 어플리케이션은 여행 정보를 제공하여 여행자가 여행 중에 주변의 관심 지점(POI; Point of Interest) 을 검색하고 찾아갈 수 있도록 돕는다. 최근 모바일 컴퓨팅 기술이 발전하면서 핸드헬드 디바이스와 웨어러블 디바이스를 여행 정보 검색에 활용하는 사용자가 늘어나고 있지만, 모바일 투어 가이드 어플리케이션들은 디바이스의 특성을 고려하지 않고 여행 정보를 제공한다. 특히 이들 투어 가이드 어플리케이션들은 여행 상황을 공유하지 않기 때문에 여러 모바일 디바이스를 이용하는 여행자는 각각의 디바이스에 여행자의 검색 의도를 별도로 입력해야 하고, 동기화된 여행 정보를 제공받지 못한다. 이러한 문제들을 개선하기 위해 본 논문에서는 디바이스의 특성에 따라 여행 정보를 제공하고 여행 상황을 공유하는 모바일 투어 가이드 시스템을 제안한다. 제안된 시스템은 핸드헬드 디바이스와 안경형 웨어러블 디바이스를 이용하여 여행자에게 여행 정보를 제공하고, 각각의 디바이스가 가진 단점을 상호 보완하면서 여행자를 안내한다. 또한 제안된 시스템은 각각의 디바이스들에 설치된 어플리케이션 사이에 여행 상황을 공유하여 여행자의 입력을 최소화하고, 여행 상황에 맞는 여행 정보를 제공한다.

• Agribusiness and Information Management
• /
• 제3권2호
• /
• pp.33-42
• /
• 2011

Although the diffusion of mobile services appears to be occurring much more rapidly than the spread of wired services, there are risks of a new type of digital divide: the mobile divide. The mobile divide, which refers to a specific digital divide that involves the unbalanced diffusion of mobile technologies, must be concretely studied. Thus, this study focuses on the mobile divide with respect to disadvantaged populations. Although various studies suggest that the diffusion of mobile devices may reduce the digital divide, somestudies argue against the positive effect of mobile devices in addressing traditional digital devices. Low and O'Connell (2006) insisted that equity of access to mobile technologies should be considered in the contextof the traditional digital divide; they argued that there may be socio-economic barriers to accessing mobile devices and the mobile Internet that are similar to the socio-economic barriers to accessing stationary computers and the stationary use of the Internet. Focusing on the smartphone divide, this study suggests that emphasizing utilization is an appropriate manner in which to bridge the mobile divide rather than focusing on other factors, such as accessibility and capability, thatprevious studies have used to measure the traditional digital divide.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제3권6호
• /
• pp.628-646
• /
• 2009

Users want to browse and search various web contents with mobile devices which can be used anywhere and anytime without limitations, in the same manner as desktop. But mobile devices have limited resources compared to desktop in terms of computing performance, network bandwidth, screen size for full browsing, and etc, so there are many difficulties in providing support for mobile devices to fully use desktop-based web contents. Recently, mobile network bandwidth has been greatly improved, however, since mobile devices cannot provide the same environment as desktop, users still feel inconvenienced. To provide web contents optimized for each user device, there have been studies about analyzing code to extract blocks for adaptation to a mobile environment. But since web contents are divided into several items such as menu, login, news, shopping, etc, if the block dividing basis is limited only to code or segment size, it will be difficult for users to recognize and find the items they need. Also it is necessary to resolve interface issues, which are the biggest inconvenience for users browsing in a mobile environment. In this paper, we suggest a personalized adaptation system that extracts item blocks from desktop-based web contents based on user interests, layers them, and adapts them for users so they can see preferred contents first.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제10권9호
• /
• pp.4044-4062
• /
• 2016

We investigate the optimization of energy consumption in Mobile Cloud environment in this paper. In order to optimize the energy consumed by the CPUs in mobile devices, we put forward using the asymptotic time complexity (ATC) method to distinguish the computational complexities of the applications when they are executed in mobile devices. We propose a multi-scale scheme to quantize the channel gain and provide an improved dynamic transmission scheduling algorithm when offloading the applications to the cloud center, which has been proved to be helpful for reducing the mobile devices energy consumption. We give the energy estimation methods in both mobile execution model and cloud execution model. The numerical results suggest that energy consumed by the mobile devices can be remarkably saved with our proposed multi-scale scheme. Moreover, the results can be used as a guideline for the mobile devices to choose whether executing the application locally or offloading it to the cloud center.

• 한국정보통신학회논문지
• /
• 제14권12호
• /
• pp.2657-2662
• /
• 2010

모바일 기기 기반의 제어시스템에서 정보 해킹과 유출에 대비한 보안기능의 적용이 요구되고 있다. 이를 위한 보안 기술로서 가장 일반적인 방법은 암호와 인증이다. 본 연구에서는 보안 기능이 취약한 모바일 기기 기반의 제어 시스템에 있어서 효율적인 인증 방식 중 하나인 CBC-MAC (Cipher Block Chaining-Message Authentication Code)을 사용하여 외부의 공격으로부터 정보를 보호하는 CBC-MAC 기반의 보안 모바일기기 제어시스템 (SMIV: Secure Mobile in Vehicle)을 제안한다. CBC-MAC 은 송신측과 수신측에 비밀 키를 공유함으로써 전송된 정보가 변경되지 않고 본래의 정보임을 보증하는 방식이다. 제안 시스템의 검증을 위하여 모바일 기기 제어 시스템의 H/W 및 S/W를 구현하고 CBC-MAC 인증 방식을 적용하였다. 기존 연구에서는 모바일 기기를 이용한 제어시스템에서 보안성보다는 개선된 제어 방식이 주로 보고되고 있다. 본 연구에서는 모바일 기기를 이용한 제어시스템에서 보안성을 제고한 모바일 기기 제어시스템을 제안하며 이러한 보안 제어 시스템은 향후 모바일 기기를 이용한 각종 제어 시스템 설계 및 구축에 유용하게 사용될 것이다.