• Asia pacific journal of information systems
• /
• 제24권4호
• /
• pp.611-635
• /
• 2014

Information systems (IS) have become ubiquitous and changed every aspect of how people live their lives. While some IS have been successfully adopted and widely used, others have failed to be adopted and crowded out in spite of remarkable progress in technologies. Both the technology acceptance model (TAM) and the IS Success Model (ISSM), among many others, have contributed to explain the reasons of success as well as failure in IS adoption and usage. While the TAM suggests that intention to use and perceived usefulness lead to actual IS usage, the ISSM indicates that information quality, system quality, and service quality affect IS usage and user satisfaction. Upon literature review, however, we found a significant void in theoretical development and its applications that employ either of the two models, and we raise research questions. First of all, in spite of the causal relationship between intention to use and actual usage, in most previous studies, only intention to use was employed as a dependent variable without overt explaining its relationship with actual usage. Moreover, even in a few studies that employed actual IS usage as a dependent variable, the degree of actual usage was measured based on users' perceptual responses to survey questionnaires. However, the measurement of actual usage based on survey responses might not be 'actual' usage in a strict sense that responders' perception may be distorted due to their selective perceptions or stereotypes. By the same token, the degree of system quality that IS users perceive might not be 'real' quality as well. This study seeks to fill this void by measuring the variables of actual usage and system quality using 'fact' data such as system logs and specifications of users' information and communications technology (ICT) devices. More specifically, we propose an integrated research model that bring together the TAM and the ISSM. The integrated model is composed of both the variables that are to be measured using fact as well as survey data. By employing the integrated model, we expect to reveal the difference between real and perceived degree of system quality, and to investigate the relationship between the perception-based measure of intention to use and the fact-based measure of actual usage. Furthermore, we also aim to add empirical findings on the general research question: what factors influence actual IS usage and how? In order to address the research question and to examine the research model, we selected a mobile campus application (MCA). We collected both fact data and survey data. For fact data, we retrieved them from the system logs such information as menu usage counts, user's device performance, display size, and operating system revision version number. At the same time, we conducted a survey among university students who use an MCA, and collected 180 valid responses. A partial least square (PLS) method was employed to validate our research model. Among nine hypotheses developed, we found five were supported while four were not. In detail, the relationships between (1) perceived system quality and perceived usefulness, (2) perceived system quality and perceived intention to use, (3) perceived usefulness and perceived intention to use, (4) quality of device platform and actual IS usage, and (5) perceived intention to use and actual IS usage were found to be significant. In comparison, the relationships between (1) quality of device platform and perceived system quality, (2) quality of device platform and perceived usefulness, (3) quality of device platform and perceived intention to use, and (4) perceived system quality and actual IS usage were not significant. The results of the study reveal notable differences from those of previous studies. First, although perceived intention to use shows a positive effect on actual IS usage, its explanatory power is very weak ($R^2$=0.064). Second, fact-based system quality (quality of user's device platform) shows a direct impact on actual IS usage without the mediating role of intention to use. Lastly, the relationships between perceived system quality (perception-based system quality) and other constructs show completely different results from those between quality of device platform (fact-based system quality) and other constructs. In the post-hoc analysis, IS users' past behavior was additionally included in the research model to further investigate the cause of such a low explanatory power of actual IS usage. The results show that past IS usage has a strong positive effect on current IS usage while intention to use does not have, implying that IS usage has already become a habitual behavior. This study provides the following several implications. First, we verify that fact-based data (i.e., system logs of real usage records) are more likely to reflect IS users' actual usage than perception-based data. In addition, by identifying the direct impact of quality of device platform on actual IS usage (without any mediating roles of attitude or intention), this study triggers further research on other potential factors that may directly influence actual IS usage. Furthermore, the results of the study provide practical strategic implications that organizations equipped with high-quality systems may directly expect high level of system usage.

• Architectural research
• /
• 제19권2호
• /
• pp.27-33
• /
• 2017

Advances in information and mobile technologies have changed the traditional firm ways of working very flexible, collaborative and innovative, resulting in the changes in work place structures and layouts. Despite the growing body of literature examining the novel ways of working, which is called smart work, there is little academic attentions paid to the spatial aspects of new work places, namely smart offices and smart work centers. This research explores the spatial changes of work places that improve business efficiency and collaboration among workers suitable for the novel ways of working. Conducting in-depth field surveys on selected cases, we analyzed the changes in spatial structure and operation policies of smart offices and smart work centers. From this survey, we observed that the new work places under study take various novel spatial forms and they have flexible operating policies such as flexible seating and flexible work hours. We also found that it would be difficult to change existing business practices and typical ways of performing tasks, without changing the bureaucratic spatial designs and layouts. Future studies are suggested to examine how spatial structures and layouts of offices have impacts on space utilization, collaboration, creativity, and job satisfaction.

• International Journal of Internet, Broadcasting and Communication
• /
• 제9권2호
• /
• pp.1-10
• /
• 2017

The high costs of electric vehicle supply equipment (EVSE) and installation are currently a stumbling block to the proliferation of electric vehicles (EVs). The cost-effective solutions are needed to support the expansion of charging infrastructure. In this paper, we develope EV charging system based on the big data analysis of the power consumption patterns. The developed EV charging system is consisted of the smart EV outlet, gateways, powergates, the big data management system, and mobile applications. The smart EV outlet is designed to low costs of equipment and installation by replacing the existing 220V outlet. We can connect the smart EV outlet to household appliances. Z-wave technology is used in the smart EV outlet to provide the EV power usage to users using Apps. The smart EV outlet provides 220V EV charging and therefore, we can restore vehicle driving range during overnight and work hours.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제10권9호
• /
• pp.4108-4122
• /
• 2016

To address challenges of an unprecedented growth in mobile data traffic, the ultra-dense network deployment is a cost efficient solution to off-load the traffic over other small cells. However, the real traffic is often much lower than the peak-hour traffic and certain small cells are superfluous, which will not only introduce extra energy consumption, but also impose extra interference onto the radio environment. In this paper, an elastic energy efficient cell management scheme is proposed based on flow scheduling among multi-layer ultra-dense cells by a SDN controller. A significant power saving was achieved by a cell-level energy manager. The scheme is elastic for energy saving, adaptive to the dynamic traffic distribution in the office or campus environment. In the end, the performance is evaluated and demonstrated. The results show substantial improvements over the conventional method in terms of the number of active BSs, the handover times, and the switches of BSs.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제10권1호
• /
• pp.136-151
• /
• 2016

Flexible large-scale WLANs are now widely deployed in crowded and highly mobile places such as campus, airport, shopping mall and company etc. But network management is hard for large-scale WLANs due to highly uneven interference and throughput among links. So the traffic is difficult to predict accurately. In the paper, through analysis of traffic in two real large-scale WLANs, Granger Causality is found in both scenarios. In combination with information entropy, it shows that the traffic prediction of target AP considering Granger Causality can be more predictable than that utilizing target AP alone, or that of considering irrelevant APs. So We develops new method -Granger Causality and Vector Auto-Regression (GCVAR), which takes APs series sharing Granger Causality based on Vector Auto-regression (VAR) into account, to predict the traffic flow in two real scenarios, thus redundant and noise introduced by multivariate time series could be removed. Experiments show that GCVAR is much more effective compared to that of traditional univariate time series (e.g. ARIMA, WARIMA). In particular, GCVAR consumes two orders of magnitude less than that caused by ARIMA/WARIMA.

• 전자공학회논문지CI
• /
• 제49권1호
• /
• pp.8-15
• /
• 2012

본 논문에서는 Hadoop 클러스터의 노드 정보와 작업 정보를 실시간으로 수집할 수 있는 새로운 모니터를 제안한다. 이 모니터는 Hadoop클러스터의 노드 정보와 작업 정보를 수집하는 Agent, 수집된 정보를 분석하고 데이터베이스에 저장하는 Collector로 구성된다. 또한 Collector를 Hadoop 클러스터에 참여하지 않은 새로운 노드에 위치시킴으로써 분석과정에서 발생하는 오버헤드로 인한 Hadoop의 작업지연을 제거한다. 제안한 모니터를 구현하고 실험적 클러스터에 적용함으로써, dead 노드의 발생을 실시간으로 파악할 수 있었다. 또한, Hadoop의 작업수행 과정에서 비효율적인 과정을 발견하고 개선함으로써 작업수행시간을 단축시킬 수 있었다.

• 한국콘텐츠학회논문지
• /
• 제6권3호
• /
• pp.116-124
• /
• 2006

멘토링은 멘토와 멘티의 지속된 관계로 정의된다. 지속적인 관여를 통해서 멘토는 멘티가 새로운 도전에 직면 또는 초기 문제들을 바로잡는데 있어서 안내와 보조, 지원을 제공한다. 협동학습을 위한 멘토링은 고급 사고력, 협력적 능력, 사회성 발달을 포함하여 많은 장점을 가진다. 본 논문에서는 유비쿼터스 환경에서의 멘토와 멘티의 사이버 커뮤니티를 이용한 교수학습 전략을 설계하기 위해서 U-CoMM시스템을 제안하였다. 제안 시스템은 참여자에게 경험과 전문지식을 공유할 수 있는 캠퍼스 멘토링 프로그램을 제공한다. 실험결과 제안 시스템은 기존 시스템보다 협동학습에 있어 교육적 효과가 있음을 보여주었다.

• 정보관리연구
• /
• 제39권2호
• /
• pp.75-94
• /
• 2008

국내 대학도서관들은 첨단 기술의 발전을 수용하고 이를 기반으로 하는 정보서비스의 기획 및 제공을 통해 도서관 서비스의 발전을 주도하고 있으며, 해당 기관 내에서 정보유통의 중심으로서 도서관의 위상을 공고히 하는 데 기여하고 있다. 본 고에서는 국내 대학도서관들에서 무선인터넷을 통해 제공하고 있는 도서관 정보서비스의 현황을 살펴보고자 한다. 이를 위해 다수 도서관이 참여하고 있는 협의체인 'WDL 모바일 캠퍼스 컨소시엄'을 통해 주도되고 있는 무선인터넷 서비스의 일반현황, 플랫폼의 구성, 서비스의 구성과 주요기능, 이용환경과 현황을 살펴보고 지속적인 발전을 위한 발전방안을 제시하였다.

• 한국콘텐츠학회논문지
• /
• 제15권1호
• /
• pp.24-30
• /
• 2015

도시의 복잡성이 증가할수록 장애인의 외출은 많은 제약을 받는다. 특히 시각장애인들은 사물뿐만 아니라 사물 주위의 환경을 인지할 수 없어 야외 활동을 하는데 있어 수많은 환경적 어려움을 겪는다. 하지만 현재 국내의 야외 환경은 시각장애인을 포함한 장애인들의 활동을 보조하는 정책적, 수단적 시설이 많이 부족한 것이 현실이다. 이에 본 논문에서는 시각장애인의 야외 활동에 도움을 줄 수 있는 길안내 시스템을 제안한다. 제안한 시스템은 시험을 위해 K대학교 J캠퍼스에 적용하였다. 제안한 시스템은 시각장애인들의 야외활동의 범위를 넓히고, 다양한 사회 활동이 가능하도록 도움을 줄 수 있다.

• Nuclear Engineering and Technology
• /
• 제53권4호
• /
• pp.1167-1175
• /
• 2021

The process of automation and monitoring in industrial control system involves the use of many types of sensors. A programmable logic controller plays an important role in the automation of the different processes in the power plant system. The major control units are boiler for temperature and pressure, turbine for speed of motor, generator for voltage, conveyer belt for fuel. The power plant units are controlled using microcontrollers and PLCs, but FPGA can be the feasible solution. The paper focused on the design and simulation of hardware chip to monitor boiler, turbine, generator and conveyer belt. The hardware chip of the plant is designed in Xilinx Vivado Simulator 17.4 software using VHDL programming. The methodology includes VHDL code design, simulation, verification and testing on Virtex-5 FPGA hardware. The system has four independent buzzers used to indicate the status of the boiler, generator, turbine motor and conveyer belt in on/off conditions respectively. The GSM is used to display corresponding message on the mobile to know the status of the device in on/off condition. The system is very much helpful for the industries working on plant automation with FPGA hardware integration.