• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1207-1215
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• 2015

The smartphone addiction research to identify the pattern according to your smartphone addiction. Recovery of 689 to 1429 parts by distributing the total recovery is 48.22%, respectively. Were utilized to study 650 data. Smartphone addiction group was divided into low, group care, group into three groups according to the degree of severity smartphone addiction. The response that smartphone addiction severity group 135 people 86.5%, lower addiction group 59 people% smartphone smartphones note 165 people group 50.2%, 35.5 'no' do you think about the own smartphone addiction (p <0.001). Showed that exceeds 50% of the smartphone severe poisoning group and attention should use having a chat group with respect to the smart phone. Also showed that beyond a midnight bed time group the more severe the smartphone addiction. Usual findings for bedtime showed a tendency to sleep late pass midnight smartphone addiction show higher water shortage phenomenon. Could be used as the basis for the study which may be a healthy life to predict the degree of occurrence of a pattern according to the type of smart phone poisoning by identifying the factors of the individual according to the degree of poisoning smartphone pattern.

• Journal of Korean Society of Transportation
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• v.23 no.4 s.82
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• pp.71-79
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• 2005

Existing arterial link travel time estimation methods relying on either aggregate point-based or individual section-based traffic data have their inherent limitations. This paper demonstrates the utility of data fusion for improving arterial link travel time estimation. If the data describe traffic conditions, an operator wants to know whether the situations are going better or worse. In addition, some traffic information providing strategies require predictions of what would be the values of traffic variables during the next time period. In such situations, it is necessary to use a prediction algorithm in order to extract the average trends in traffic data or make short-term predictions of the control variables. In this research. a multi-step ahead prediction algorithm using Data fusion was developed to predict a link travel time. The algorithm performance were tested in terms of performance measures such as MAE (Mean Absolute Error), MARE(mean absolute relative error), RMSE (Root Mean Square Error), EC(equality coefficient). The performance of the proposed algorithm was superior to the current one-step ahead prediction algorithm.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.5
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• pp.372-379
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• 2017

Software reliability factor during the software development process is elementary. Case of the infinite failure NHPP for identifying software failure, the occurrence rates per fault (hazard function) have the characteristic point that is constant, increases and decreases. In this paper, we propose a reliability model using the chi - square distribution which depends on the degree of freedom that represents the application efficiency of software reliability. Algorithm to estimate the parameters used to the maximum likelihood estimator and bisection method, a model selection based on the mean square error (MSE) and coefficient of determination($R^2$), for the sake of the efficient model, were employed. For the reliability model using the proposed degree of freedom of the chi - square distribution, the failure analysis using the actual failure interval data was applied. Fault data analysis is compared with the intensity function using the degree of freedom of the chi - square distribution. For the insurance about the reliability of a data, the Laplace trend test was employed. In this study, the chi-square distribution model depends on the degree of freedom, is also efficient about reliability because have the coefficient of determination is 90% or more, in the ground of the basic model, can used as a applied model. From this paper, the software development designer must be applied life distribution by the applied basic knowledge of the software to confirm failure modes which may be applied.

• Korean Chemical Engineering Research
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• v.58 no.3
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• pp.416-423
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• 2020

Majority of over 100 kW capacity photo voltaic (PV) power generation system was constructed on the plate ground of soil. Rarely PV system installed on concrete or building but it usually be under 25 kW capacity. On the soil ground the weeds growen up and it's shadow influenced to decrease of amount of PV power generation. This work analysis the weeds shadow's effect to decrease of PV power generation with 100 kW capacity of real PV power generation system in Yeungnam University, Finally the weed shadow"s influence value through the real field monitoring Data is suggested for give a standard management time of weeds to avoid the negative influence on whole power plant. Moreover the hot spot which is generated by long term partial shallow on PV module also can detected with the result of this work. It also suggested as a standard value of monitoring Data.

• Information Systems Review
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• v.18 no.2
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• pp.199-223
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• 2016

As social networking services (SNS) become widely used tools for maintaining social relationships, people use SNS to express themselves online. Users are free to form multiple characters in SNS because of online anonymity. This phenomenon causes SNS users to easily demonstrate multiple personas that are different from their identities in the real world. Therefore, this study focuses on online multi-personas that establish multiple fake identities in the SNS environment. The main objective of this study is to investigate factors that affect online multi-personas. Fake online identities can have various negative consequences such as cyber bullying, cyber vandalism, or antisocial behavior. Since the boundary between the online and offline worlds is fading fast, these negative aspects of online behavior may influence offline behaviors as well. This study focuses on teenagers who often create multi-personas online. According to previous studies, personal identities are usually established during a person's youth. Based on data on 664 teenage users, this study identifies four emotional factors, namely, closeness with others, relative deprivation, peer pressure and social norms. According to data analysis results, three factors (except closeness with others) have positive correlations with users' multi-personas. This study contributes to the literature by identifying the factors that cause young people to form online multi-personas, an issue that has not been fully discussed in previous studies. From a practical perspective, this study provides a basis for a safe online environment by explaining the reasons for creating fake SNS identities.

• Information Systems Review
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• v.10 no.3
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• pp.133-153
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• 2008

Understanding of the length of time required to realize the return on the investment of informatization is important for policy makers and decision makers of information system adoption. Previous researchers, however, assessed this issue with the performance measurement approach that was primarily based on static point of view. However, the static analysis on the outcome of the informatization investment is limited in measuring the priori and ex ante effects of the informatization implementation on temporal basis. This study present a methodology to capture the outcome of the informatization investment on dynamic basis. This assessment was performed based on an e-government project in Korea, called "Industry Human Resource Project." Particularly, the study addressed how long it takes to obtain the benefit of WorkNet System, which was part of this Korean e-government project. We proposed various approaches to illustrate the importance and temporal effect of the WorkNet System by analyzing DB data, time reduction of WorkNet business processes and return of investment of IT.

• Journal of the Korean Data and Information Science Society
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• v.23 no.5
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• pp.1005-1015
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• 2012

Since the smartphone was first released in 2009, its common use has made everyday life convenient but caused many social problems. In this article, we surveyed the status of smartphone usage and identified the influence of smartphone addiction on mental health, campus life and personal relations of university students. We gave the methods to prevent smartphone addiction, which could be used as basic materials for solving the problems. We found the smartphone addiction syndrome cause problems of mental health, campus life and personal relations in many ways. In addition to significant direct effects, smartphone addiction has significant indirect effects on personal relations via mental health and campus life as a medium.

• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.73-79
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• 2012

Currently, all domestic CNG vehicles have manual cylinder valves installed. These are inconvenient for drivers in case of a gas leak accident, because drivers have to stop the vehicle operation and manually close the valve. It makes difficult condition for drivers to quickly and properly respond to such accidents. In advanced European countries, they require Automatic cylinder valve installation, which has a structure where the valve is automatically shut off when the driver turns off the ignition in case of a gas leak. If this electric valve system is introduced in Korea, the safety of CNG buses will be improved with better functionalities. In this paper, in order to solve the structural problem of difficulty for a driver to identify the operational status of individual Automatic cylinder valves, an approach was made regarding temperature increase with pressure increase during CNG filling. it was estimated that the temperature increased approximately more than $30^{\circ}C$ due to pressure difference during the filling. Therefore, it was concluded from the experimental data that the valve of the container whose temperature did not increase did not operate, resulting in filling failure.

• Geophysics and Geophysical Exploration
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• v.23 no.4
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• pp.253-260
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• 2020

The five-story stone pagoda in Tamni-ri located in Uiseong County in Gyeongsangbuk-do had an unstable upper structure, and the structural deformation of the foundation stone and the stylobate was severe. In order to repair the base of the pagoda, it must be confirmed if there are support stones inside the base. Resistivity survey was performed to study the inner base stone structure during the repair work. The stylobate was exposed soil and broken stones after removing the walls and the cover of the stylobate. Modified pole-dipole array II was used for the resistivity survey, and compared with the typical pole-dipole array method. And in this study, a physical scale-down model experiment was performed to compare and analyze distortions caused by severe topographical undulations such as right-angled lines. The results show that the stylobate of Five-story Stone Pagoda in Tamni-ri Uiseong has base stones inside the reinforced filling soil and are located beneath the pillar of the body and supporting the pagoda.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.2
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• pp.149-156
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• 1999

An experimental simulation on the flow in Czochralski melt using a cold model was carried out to obtain the velocities of fluid flow which affects the oxygen concentration of Czochralski crystal growing system. Low melting point Woods metal with similar Pr number to the silicon melt was adopted as a working fluid. Local flow velocities at numerous positions in the melt were simulataneously measured in three dimension using incorporated magnet probe. The measured velocity field showed a non-axisymmetric pattern dominated by natural convection. The analysis on the correlation between data set of temperatures simultaneously measured at two melt positions showed that the values of correlation coefficients were smaller than those of previous study on the small size of silicon melt and these phenomena are believed to occur because turbulent behavior becomes stronger in large size of the melt.