• Asia pacific journal of information systems
• /
• v.24 no.4
• /
• 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.

• Journal of Nutrition and Health
• /
• v.40 no.8
• /
• pp.736-744
• /
• 2007

Leptin, as an adipocyte-derived hormone, is an important regulator of food intake and energy expenditure. In the cross-sectional study, leptin was shown to be positively related to body adiposity and metabolic disorders in adults. However, there were very few studies which reported the leptin as a predictor of weight gain over time. We examined whether serum leptin can be used as an indicator of the present and 1-year past weight status in very young children. First grade students from elementary schools in Gwacheon City were enrolled in the study since 2005. The study subjects(total 375 students; 195 boys and 180 girls) participated in the investigation of both 2005 and 2006. Physical examinations including height, weight, waist circumference were done. To examine the prevalence of obesity, obesity index was used. Serum leptin was measured, and their nutritional status was also evaluated based on 3-Day dietary records. Serum leptin levels were strongly positively related with the value of the present BMI and with the value of the BMI one year before. We found no association with leptin levels and amount of energy intake and macronutrient intake in this children population. Children were divided into three groups according to leptin tertiles. The highest leptin tertile group showed highest prevalence of obesity in year 2006 as well as in year 2005. Serum leptin levels can reflect the weight status now and as well as 1-year before. Possibly serum leptin levels can predict the weight gain of year later. Without an action against the obesity on children with high leptin level, those children would maintain the excess adiposity growth and progress into the obesity-related metabolic disorders. Further studies are needed to predict the obesity as early as possible and preventive system then after.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.30 no.1
• /
• pp.113-124
• /
• 2012

The Confucian culture of the Chosun Dynasty has a great effect on the construction of ByeolSeo gardens. Among them, especially the gardens built in Gyeongsang Province areas, where a great number of Confucian scholars were produced in the beautiful natural environment, have maintained various heritage of Confucian culture established by the scholars. Along with the Nakdong River, we can find so many cultural assets of buildings such as head houses, ByeolSeo gardens, including the literary remains such as administrative certificates, poetry and prose, and records of pavilions, which show the trace of the scholars who followed the instructions of the doctrines of Chu-tzu. The Geumseonjeog located in Punggi County, Gyeongsangbuk Province, which was the ByeolSeo gardens possessed by Geumgye Whang Jun-ryang(1517-1563), who was the governor of the area and one of the representative students of Toigye Lee Whang. The building is located nearby the Geumseon Valley with beautiful natural scenery under Sobaek Mountain. Especially the pine forest around the valley boasts a unique natural setting. This study is aimed to analyze the value of natural scenic spot of the Geumseonjeong through the surveys on surroundings, topography, vegetation and water system. including the value of humanistic elements focused on the writings such as 'Geumgyejip' written by Whang Jun-ryang and Lee Whang, another 'Geumgyejip' written by Ryu un-ryong, and 'Geumgyejeongsajungsugi' written by Hong Gyeong-ryeom. And also, the scenic spot value of the signboards such as the 'Geumgyejeongsajungsugi' written by Ryu un-ryong, 'Geumgyejeong' by Lee Han-il, 'Geumgyejeong' written by Jo Un-hyeong and 'Geumgyejeongsa, written by Lee Jung-gi, was analyzed. And the historical and cultural value was analyzed through the semantic interpretation of the series of poetry and pose and the old map established in 1872. In respect of the scenery, the surroundings of the Geumseon Valley boast the outstanding settings as the clean mountain stream in front of the Geumseonjeong makes a beautiful harmony with the pine forest. The pine forest surrounding the Geumseon Valley has played a secret role in the history of the village. Considering the fact that the pine forest was expressed in the map of Punggi County produced in 1872, it may be assumed that the forest was regarded to have historical and scenic value in those times. Considering the fact that the words like 'Beautiful' and 'Scenic spot' were used in the writings like 'Geumgyejip' and there were meeting places around the valley, we can recognize the value of the place as a scenic spot. The beautiful natural scenery surrounding the ByeolSeo gardens, and the increase in humanistic value of the poetry and prose, including the administrative certificates, has recently brought about the cases in which some scenic spots of the ByeolSeo gardens were designated as cultural assets. According to the value as a scenic spot and semantic interpretation of the Geumseonjeong, the pavilion appeared to have a great scenic spot value as a ByeolSeo gardens, so that this study was designed to prepare criteria with which the pavilion may be designated as a scenic spot of ByeolSeo gardens.