• Journal of KIISE
• /
• v.43 no.7
• /
• pp.786-794
• /
• 2016

Recommender systems can be used to assist users in selecting required services for their tasks in Internet of Things (IoT) environments in which diverse services can be provided by utilizing IoT devices. Traditional research on recommendation mainly focuses on predicting preferences of individual users. However, in IoT environments, not only individual users but also groups of users can access services in the environments. In this study, we analyzed user groups' preferences on services and developed service recommendation approach for new groups that do not have a history of accessing IoT-services in a certain place. Our approach extends the traditional user-based collaborative filtering by considering the similarity between user groups based on their member organization. We conducted experiments with a real-world dataset collected from IoT testbed environments. The results demonstrate that the proposed approach is effective to recommend services to new user groups in IoT environments.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.42 no.1
• /
• pp.115-128
• /
• 2019

Small and Medium-sized Enterprises (SMEs) are being faced with rapid changes in their business environments due to evolution of technologies and innovation in societal eco-systems. Particularly, dynamic interactions between such environments and enterprise activities have become significant, so technology planning, which is a process of identifying appropriate directions regarding product and technology development, has received much attention to cope with such dynamics proactively. However, SMEs typically have limits in performing independent, strategical and systematical technology planning activities due to the lack of human, material and financial resources. This paper proposes the development of a product roadmapping method so that SMEs carry out efficient technology planning activities with interconnections of external business environments. The present work provides product roadmap templates that directly accommodate the influence of business environments on the product's system and its associated super/sub-systems with the use of external environment analysis techniques including TRIZ methodology, PEST and 5Forces analysis. These templates are useful to efficiently forecast the directions of product's development and evolution, which arise from changes in external environments. Consequently, the present work enables SMEs to flexibly cope with the era of the next R&D generation, which pursues value creation through mutual interconnection between business environments and technology development.

• Design Convergence Study
• /
• v.15 no.5
• /
• pp.199-211
• /
• 2016

The study examined how age-friendly their living environments the aged perceived and it's significant difference depending on their characteristics. The subject were 96 old persons who aged more than 60 years and lived in Nagasaki city, Japan. They asked how far each neighborhood facility related to the aged was located from their houses, and the age-friendliness of walk way, traffic, multi-family houses for the aged, and interior space of their living houses. Data were collected by using one to one interview. Results were as follows: 1) Most neighborhood facilities related to the aged were located within a walking distance or 10 min. distance by bus from their houses. 2) Among 5 areas of living environments, while traffic, house interior, and pedestrians road were relatively age-friendly, the amount of multi-unit dwellings for the elderly and the usability of wheelchair users in house interior were not age-friendly. 3) Age and education level of the aged influenced on the age-friendliness of their living environments.

• Journal of The Korean Association For Science Education
• /
• v.29 no.5
• /
• pp.492-500
• /
• 2009

The purpose of the study was to investigate middle school students' and teachers' perception of psychological learning environments as well as the differences between them. This study sampled 503 middle school students and the 16 teachers who taught them. 'Psychological Learning Environment Instrument by Science Teacher' was implemented to collect data. Frequency analysis and descriptive statistics, as well as t-test, ANOVA were used for basic analysis of data. There were statistically meaningful differences in students' perception of psychological learning environments by gender, science achievement, science preference and self-efficacy in science. However, there are no differences in teachers' perceptions of psychological learning environments by gender, age, career year and major. The difference between teachers' and students' perception of psychological learning environments was not large, showing no statistical significance. However, teachers' perceptions of psychological learning environments was a little higher than that of students.

• Journal of Environmental Health Sciences
• /
• v.43 no.4
• /
• pp.324-333
• /
• 2017

Objectives: The purpose of this study was to assess the correlation relationship between personal exposure and urinary hippuric acid in biological monitoring for airborne toluene in an industrial complex and in general environments. Methods: Personal exposure to toluene and its metabolite, hippuric acid, in urine were simultaneously measured in occupational environments area near an industrial complex and in general environments. The study subjects were divided into three types: 137 workers who use organic solvents in the workplace, 210 residents living near a dyeing industrial complex, and 379 residents living in general environments. The toluene exposures of workers and residents were measured by a passive sampler for four days. The urine of participants was sampled when the passive samplers of personal exposure were collected. Results: The toluene and hippuric acid concentrations of workers were the highest, followed by the concentrations of residents living near a dyeing industrial complex and residents living in general environments. The coefficient of correlation between the concentrations of toluene and hippuric acid among workers was 0.749 (p<0.01) in the workplace. On the contrary, correlations between the concentrations of toluene and hippuric acid among residents living near a dyeing industrial complex and residents living in general environments were all not significant. The relationship between the concentrations of hippuric acid and toluene in three types could be described by the exponential growth model. Conclusions: This study analyzed the relationships between toluene exposure and the concentrations of hippuric acid in urine in high, middle, and low exposure environments, and could be described by the exponential growth model.

• Proceedings of the Mineralogical Society of Korea Conference
• /
• 2001.06a
• /
• pp.16-22
• /
• 2001

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.10a
• /
• pp.841-842
• /
• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.609-610
• /
• 2013

• Proceedings of the Petrological Society of Korea Conference
• /
• 2001.06a
• /
• pp.16-22
• /
• 2001

• Proceedings of the Korean Society for Emotion and Sensibility Conference
• /
• 2012.05a
• /
• pp.45-46
• /
• 2012