• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.1
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• pp.64-69
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• 2013

In ubiquitous computing, shared environments adjust themselves so that all users in the environments are satisfied as possible. Inevitably, some of users sacrifice their satisfactions while the shared environments maximize the sum of all users' satisfactions. In our previous work, we have proposed social welfare functions to avoid a situation which some users in the system face the worst setting of environments. In this work, we consider a more direct approach which is a preference based clustering to handle this issue. In this approach, first, we categorize all users into several subgroups in which users have similar tastes to environmental parameters based on their preference information. Second, we assign the subgroups into different time or space of the shared environments. Finally, each shared environments can be adjusted to maximize satisfactions of each subgroup and consequently the optimal of overall system can be achieved. We demonstrate the effectiveness of our approach with a numerical analysis.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.1
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• pp.13-17
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• 2004

The aim of this study was to investigate genetic development and genotype${\times}$environment interactions (GEI) in postweaning body weight of fattening bulls at the end of test period (WT-T) under various beef fattening environments. Data on a total of 24,247 fattening bulls obtained from the industrial farm, breeding farms and testing stations were used. Heritability estimates for WT-T in all environments were nearly similar. Significant genetic developments of sire, dam and progenies for WT-T were observed in all environments. However, many differences in annual genetic developments between the environments were significant. The genetic correlations for WT-T between industrial farm and breeding farms, industrial farm and testing stations and breeding farms and testing stations were respectively 0.004, 0.004 and 0.013. These low estimates of genetic correlations and significant differences in genetic developments among environments clearly show the existence of GEI for WT-T among various fattening environments. Results of this study indicate the need for environment-specific genetic evaluation and selection of beef bulls for commercial beef production.

• Journal of Environmental Health Sciences
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• v.43 no.4
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• pp.324-333
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• 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
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• 2001.06a
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• pp.16-22
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• 2001

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

• Journal of Environmental Science International
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• v.11 no.8
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• pp.801-810
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• 2002

The current paper describes the indoor/outdoor air quality in school environments through analyses of the heavy metal concentrations using Inductive Coupled Plasma(ICP). School environments in a heavy traffic area, two industrial areas, quasi-industrial area, and residential area were evaluated. The results were as follows: (1) The locations with the highest indoor and outdoor concentrations of heavy metals were the industrial areas followed by the heavy traffic area, residential area, and quasi-industrial area in a descending order of magnitude. Plus, the indoor heavy metal concentrations were higher then the outdoor ones. (2) The main heavy metal components were Zn, Al and Ca. Higher concentration levels were found indoors than outdoors. The heavy metal concentrations were also higher in the classrooms than in the corridor or outdoors. (3) The total heavy metal concentrations in the studied areas were highly dependent on the weather elements. including the relative humidity, mixing ratio, and wet-bulb depression. Accordingly, special ventilation systems are recommended to reduce air pollution in school environments.

• IE interfaces
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• v.14 no.3
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• pp.326-333
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• 2001

The purpose of this paper is to empirically investigate the relationships between market environments and technology strategy using the data gathered from Korean manufacturing firms. As the significant environmental factors influencing company's technology strategy, two sorts of market aspects are considered; market competition factor and technological dynamics factor. And companies are categorized with respect to the characteristics of market environments they are facing with. Then we seek to find the differences in the contents of technology strategy among the companies in different types of environments through statistical analysis. As a result, it is found that there exist significant relationships between the companies' technology strategy and the environments facing firms.

• IE interfaces
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• v.21 no.1
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• pp.65-74
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• 2008

In the future, the ubiquitous computing environment will provide users with context-aware services, intelligently interacting with omnipresent resources and surrounding environments at any location and time. Therefore, the ubiquitous computing environment requires context-aware applications in order to gather and analyze context information in various situations. However, existing context-aware applications have mainly focused on providing services and adapting themselves to users based on user related contexts. But this environment requires not only user related contexts but also Quality-of-Service (QoS) related contexts. In this paper we propose a frame-work for supporting user-oriented QoS in ubiquitous environments. The proposed approach adopts a semantic ontology and a neural network algorithm in order to reason about explicit and uncertain contexts. We also show the possibility of applying the framework to real environments such as collaborative engineering service, automobile maintenance service and ubiquitous home service.

• IE interfaces
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• v.16 no.2
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• pp.149-155
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• 2003

The focus of this study is to investigate how personal display systems - a VDU (Visual Display Unit) and an HMD (Head Mounted Display) physiologically affect the body in virtual environments, and to evaluate differential effects of using the VDU and the HMD on physiological responses to mental stressful tasks (virtual reality flight simulation). As physiological variables, autonomic measures (heart rate, blood pressure), immune cells (leukocyte, neutrophil, lymphocyte), and hormones (catecholamine) were measured before and after experiments. Physiological data were measured in order to compare a level of mental stress on the VDU and the HMD. Increments in blood pressure (systolic (p<0.05), diastolic (p<0.1)), norepinephrin (catecholamine) (p<0.005), and neutrophils (p<0.2) of the group using the HMD showed a significant difference with the group using the VDU. Although, the heart rate was not statistically significant between two environments, differences of them quietly increased on the HMD more than on the VDU.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2003.05a
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• pp.3-7
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• 2003

For high performance Grid environments, an efficient GIS(Grid Information Service is required In the Metacomputing Directory Service(MDS) of the Glogus middleware, the Lightweight Directory Access Protocol(LDAP), which is a distributed directory service protocol, is used. The LDAP GIS differs from general purpose LDAP directories in that most of the LDAP operations are write in Grid environments. To get an efficient design of the GIS, it is thus required to analyze the performance of the LDAP system in the context of Grid environments. This paper presents the result of a performance analysis of LDAP systems. The main objective of the evaluation is to see the performance scalability of the LDAP system in the Grid environment where the write operations prevails. Based on these results, we suggest directions of an efficient LDAP-based GIS for a high performance Grid.