• Journal of IKEEE
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• v.23 no.4
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• pp.1328-1336
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• 2019

To maintain the safe and optimal performance of batteries, accurate estimation of state of charge (SOC) is critical. In this paper, Long short-term memory network (LSTM) based on the artificial intelligence algorithm is applied to address the problem of the conventional coulomb-counting method. Different discharge cycles are concatenated to form the dataset for training and verification. In oder to improve the quality of input data for learning, preprocessing was performed. In addition, we compared learning ability and SOC estimation performance according to the structure of LSTM model and hyperparameter setup. The trained model was verified with a UDDS profile and achieved estimated accuracy of RMSE 0.82% and MAX 2.54%.

• The KIPS Transactions:PartD
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• v.13D no.6 s.109
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• pp.789-796
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• 2006

Context-aware is the core in ubiquitous environment of sensor network to support intelligent and contextual adaptation service. The new context information model is demanded to support context-aware applications. The model should not depend on a specified application and be shareable between applications in the same environment. Also, it should support various context representation and complex context-aware. In this paper, we define the context information according to context-aware process. Also we design the knowledge of domain as well as applications using ontologies and rules. The domain spatial ontology and application knowledge are represented using the spatial object model and the rules of expanded ontologies, respectively. The expression of abundant spatial ontology represents the context information about distance between objects and adjacent object as well as the location of the object. The proposed context information model which is able to exhibit various spatial context and recognizes complex spatial context through the existing GIS. This model shows that it can adapt to a large scale outdoor context-aware applications such as air pollution and prevention of disasters as well as various context-aware applications.

• The Transactions of the Korea Information Processing Society
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• v.6 no.2
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• pp.415-424
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• 1999

Systematic telecommunication network management is essential for operating large-scale integrated networks which consist of various network components manufactured by different vendors. ISO and ITU-T recommend the CMIP-based TMN architecture for this purpose. TMN uses GDMO for the definition of managed objects, and various GDMO compilers have been developed. However, the development of management objects by using these compilers is still a difficult task. In this paper, we present a GUI-based managed objects development environment, MODE. MODE divides managed object codes by system independent code(SIC) and system dependent cede(SDC). By providing development environments for SIC and SDC, MODE can ease the development of managed objects. To show the efficiency of MODE, we develop the managed objects of an ATM switch in MODE.

• Journal of the Korea Convergence Society
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• v.12 no.2
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• pp.221-231
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• 2021

This paper identify factors of migration of employees' household who work for relocated public institutions. As a factors of migration, we consider individual and household characteristics, the gravity model of distance and population and so on. Considering discrete dependant variable and structure of data, we employ the logistic multilevel model and random intercept model. The result indicates employees' who are female, 30s and 40s, higher education level(PhD) and whose spouse are unemployed tend to transfer their residential registration to new city near relocated public institution. Regarding regional variable, the distance from employee's previous residential location and number of migration of prior year are statistically significant. Also the model indicate regional economy, educational and residential environment of new city influence employee's decision for transferring residential registration.

• Journal of Korean Society of Transportation
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• v.35 no.3
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• pp.183-196
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• 2017

In this study, policy evaluation scheme was established to encourage the efficient implementation of EcoMobility which has been expanding gradually all around the world. A total of eight evaluation goals and 22 evaluation items are reviewed and suggested based on the three major evaluation categories of "Basic elements for EcoMobility", "Land use and transport system for EcoMobility", and "Implications and impact of EcoMobility". The results of this study are as follows: the result of AHP analysis which reflects only the hierarchical structure shows a high priority in "Elements for EcoMobility promotion", "Eco-fiendly transport infrastructure", and "Safety in transport". While in result of ANP which considered the elements' dependencies, "Eco-fiendly transport Services", "Welfare in transport", and "Environment by transport" have high weights and importances. In conclusion, this study would be useful to make reasonable judgment based on the analysis results of the two techniques in order to ensure reliability in evaluation of EcoMobility policy. Furthermore we have confirmed appropriate evaluation technique between AHP and ANP which is better to reflect the features of EcoMobility.

• Journal of Digital Convergence
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• v.20 no.3
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• pp.63-68
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• 2022

This After the debut of 5G, our lives have changed a lot. In particular, the proliferation of wireless network services through smartphones and LTE has completely changed the existing mobile communication services that are limited to voice/text communication between individuals and individuals, and new innovative services have emerged in all aspects of personal and corporate activities. This study verified the relationship between the social characteristics of 5G services and users' willingness to use 5G services. It analyzed the influence relationship between independent variables (social reality, subjective norms), media variables (perceived usefulness) and dependent variables (use intention), set hypotheses, and identified the media effects of perceived usefulness. The measurement items of variables are defined, and the research model of 5G service usage intention is designed. A questionnaire survey was conducted on the measurement items for users who have experience in using 5G services. Based on this result, among the social factors of users of 5G services, social reality and subjective norms are suitable factors to improve users' intentions. And through this research we put forward the enlightenment, discussed the limitations of the research and future research directions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.335-344
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• 2020

This study compared the structures and changes of help network between pre-service secondary teachers and pre-journalists who participated in the class related to network analysis to seek ways to activate a professional learning community. For this study, we used Exponential Random Graph Models (ERGM) based on ties as being interdependent and not conventional regression models requiring assumptions of independence between observations. The analysis subjects were 43 pre-service secondary teachers and 29 pre-journalists who responded both early and late in the help network survey. The main results were as follows. First, full models with network structural terms were better than simple models with no structural terms. Second, the effect of transitivity was not statistically significant in the pre-service secondary teachers' network. However, it was statistically significant in the pre-journalists' network. Third, there were effects of reciprocity, indegree popularity, and outdegree activity in the early help network of pre-service secondary teachers. On the contrary, there were only the positive effects of reciprocity and the negative effect of outdegree activity in the late network. Finally, this study demonstrated the possibility in educational fields' application of network structural effects and provided limitations and directions for future research.

• Journal of Korean Society of Transportation
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• v.24 no.4 s.90
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• pp.7-17
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• 2006

The purpose or this paper is to investigate the relationship between highway improvement and Induced Travel Demand(ITD) focusing on the Seoul metropolitan area data. In addition, authors tried to estimate basic unit of demand elasticity focusing on zone and trip purpose which can be applied for the ITD forecasting. The results are based on the 2002 Metropolitan Household Transportation Survey Data, where the demand elasticity (DE) is -0.582 in Seoul, -0.597 in Incheon and -0.559 in Gyounggi province, respectively. This study revealed part of the relationship between highway improvement and ITD for metropolitan region and provided the framework for yielding real estimated values by applying the concept of demand elasticity in terms of the relationship by using regional and long-term data. We expect that the basic unit of demand elasticity focusing on zone and trip purpose can be applied for the ITD forecasting to analyze the whole demand exactly The estimated DE's for age group and day of week can also be used for Proper transportation management and transport Policy making. Some limitations have also been discussed.

• Journal of IKEEE
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• v.26 no.4
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• pp.633-638
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• 2022

Rencently, neuromorphic systems of spiking neural networks (SNNs) that imitate the human brain have attracted attention. Neuromorphic technology has the advantage of high speed and low power consumption in cognitive applications and processing. Resistive random-access memory (RRAM) for SNNs are the most efficient structure for parallel calculation and perform the gradual switching operation of spike-timing-dependent plasticity (STDP). RRAM as synaptic device operation has low-power processing and expresses various memory states. However, the integration of RRAM device causes high switching voltage and current, resulting in high power consumption. To reduce the operation voltage of the RRAM, it is important to develop new materials of the switching layer and metal electrode. This study suggested a optimized new structure that is the Metal/Al₂O₃/HfO_x/SWCNTs/N+silicon (MOCS) with single-walled carbon nanotubes (SWCNTs), which have excellent electrical and mechanical properties in order to lower the switching voltage. Therefore, we show an improvement in the gradual switching behavior and low-power I/V curve of SWCNTs-based memristors.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.6
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• pp.95-114
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• 2020

This paper, a meta-analysis of the effect of the start-up support policy on the start-up performance was conducted to examine the effect of the start-up support policy on the start-up performance of beneficiary companies and to provide theoretical and practical implications to support organizations and practitioners. To this end, 35 papers containing the correlation coefficient, which is a positive statistical value, were selected from the previous studies in academic journals and dissertations published in Korea from 2007 to 2020. In the preceding study of the start-up support policy, the independent variables include funding, education support, facility/equipment support, network support, mentoring support, consulting support, marketing support, management support, technical support, manpower support, and finance as a dependent variable. The effect size of the impact on aptitude and non-financial performance was reviewed. The pattern of the effect size was presented as a forest plot for easy visual understanding, and outliers were verified through sensitivity analysis for small-study-effect data with publication convenience. As a result of analyzing the effect size of the government-supported policy, it was verified that the effect size was generally medium or higher, affecting the entrepreneurial performance. Among the independent variables, the factor that has the greatest effect on startup performance is manpower support, followed by technical support, marketing support, management support, facility/equipment support, education support, mentoring support, funding, network support, and consulting support. It was analyzed that the effect size was large in order. As the 「Small and Medium Business Startup Support Act」 was recently reorganized from the manufacturing industry to digital transformation and smartization on October 8, 2020, the start-up support policy should consider the start-up stage and verify the priorities to organize the budget.