• The Journal of the Korea Contents Association
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• v.8 no.9
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• pp.19-26
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• 2008

With the development of ubiquitous computing and the construction of infrastructure for one-to-one personalized services, the importance of context-aware services based on user's situation and environment is being spotlighted. The smart home technology connects real space and virtual space, and converts situations in reality into information in a virtual space, and provides user-oriented intelligent services using this information. In this paper, we proposed the discovery of the behavior sequence pattern using the mining in the smart home. We discovered the behavior sequence pattern by using mining to add time variation to the association rule between locations that occur in location transactions. We can predict the path or behavior of user according to the recognized time sequence and provide services accordingly. To evaluate the performance of behavior consequence pattern using mining, we conducted sample t-tests so as to verify usefulness. This evaluation found that the difference of satisfaction by service was statistically meaningful, and showed high satisfaction.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.6
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• pp.114-122
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• 2014

Currently, global warming has become a serious problem arising from the usage of fossil fuels such as coal and petroleum. Moreover, due to the global warming, heat wave, heavy snow, heavy rain, super typhoon are frequently occurring all over the world. Due to these serious natural disasters, concrete structures and infrastructures are seriously damaged or collapsed. In order to handle these problems, climate change oriented construction technology and codes are necessary at this time. Therefore, in this study, the validity of the present concrete mixture proportions are evaluated considering temperature and humidity change. The specimens cured at various temperature and humidity conditions were tested to obtain their compressive and split tensile strengths at various curing ages. Moreover, performance based evaluation (PBE) method was used to analyze the satisfaction percentage of the concrete cured at various condition. From the probabilistic method of performance evaluation of concrete performance, feasibility and usability can be determined for future concrete mix design.

• Journal of Convergence for Information Technology
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• v.10 no.7
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• pp.240-248
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• 2020

This study compares and analyzes the tasks and evaluation methods of national technically qualified Skin Esthetic through systematic literature review of prior studies on qualification tests for Skin Esthetic qualification and process evaluation types that have been reorganized based on NCS. The national technical qualification is based on the ability to work through memorization-oriented theoretical tests and simple repetition of functions, and the Qualified qualification is relatively short in the period of test execution, and the reliability of its internal evaluation at the enforcement agency continues to be reduced. In the future, national technical qualification require innovation in the qualification system to reflect skilled demand at industrial sites, and course-based qualification for require supplementation and improvement of education and training courses so that they can learn skilled skills at the site.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.6
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• pp.79-88
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• 2015

In this paper, we examine Ethernet based vehicle network which is recently emerging technology. Current MOST for entertainment will be soon replaced with the emerging Ethernet based vehicle network. Although legacy standard Ethernet has several advantages it is not suitable for vehicle backbone network without any modification. As a result, many researches are happening on extending and modification of the Ethernet function for realtime and reliability. Time-triggered Ethernet, one of many trials known as AS6802, is investigated on the architecture and functionalities. We design the traffic model on Time-triggered Ethernet and analyse the latency of the network. We also consider the QoS requirement and environment of operating configuration for vehicle network.

• Journal of Digital Convergence
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• v.8 no.1
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• pp.11-26
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• 2010

The purpose of this paper is to study building and maintaining consumer trust in mobile contents for tourism and travel in perspective of public sector. Mobile contents services are increasing rapidly. Tourism contents in mobile services are non profit business model in an early and immature stage toward the ubiquitous era. Non-profit organization plays a role as service provider through Internet and wireless telecommunication in an information-intensive and network-oriented environment. This article is proposed nonprofit organizations as tourism contents service provider to identify a conceptual framework that can build continuous trusted mobile contents under ubiquitous environment according to developing and maintaining stage. The results based on the focus group interview methodology highlights a conceptual foundation for service providers in nonprofit domain.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.3
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• pp.53-60
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• 2020

Evaluating the operational efficiency of electric vehicle charging stations (EVCSs) is important to understand charging network evolution and the charging behavior of electric vehicle users. However, aggregation of efficiency performance metrics poses a significant challenge to practitioners and researchers. In general, the operational efficiency of EVCSs can be measured as a complicated function of various factors with multiple criteria. Such a complex aspect of managing EVCSs becomes one of the challenging issues to measure their operational efficiency. Considering the difficulty in the efficiency measurement, this paper suggests a way to measure the operational efficiency of EVCSs based on data envelopment analysis (DEA). The DEA model is formulated as constant returns of output-oriented model with five types of inputs, four of them are the numbers of floating population and nearby charging stations, distance of nearby charging stations and traffic volume as desirable inputs and the other is the traffic speed in congestion as undesirable one. Meanwhile, the output is given by the charging frequency of EVCSs in a day. Using real-world data obtained from reliable sources, we suggest operational efficiencies of EVCSs in Seoul and discuss implications on the development of electric vehicle charging network. The result of efficiency measurement shows that most of EVCSs in Seoul are inefficient, while some districts (Nowon-gu, Dongdaemun-gu, Dongjak-gu, Songpa-gu, Guro-gu) have relatively more efficient EVCSs than the others.

• Journal of Korean Society of Archives and Records Management
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• v.20 no.4
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• pp.1-17
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• 2020

Along with the development of information technology, the digitalization of archives has also been accelerating. However, digital archives have limitations in effectively searching, interlinking, and understanding records. In response to these issues, this study proposes a knowledge graph that represents comprehensive relationships among heterogeneous entities in digital archives. In this case, the knowledge graph organizes resources in the archives on the Korean financial crisis of 1997 by transforming them into named entities that can be discovered by machines. In particular, the study investigates and creates an overview of the characteristics of the archives on the Korean financial crisis as a digital archive. All resources on the archives are described as entities that have relationships with other entities using semantic vocabularies, such as Records in Contexts-Ontology (RiC-O). Moreover, the knowledge graph of the Korean Financial Crisis of 1997 is represented by resource description framework (RDF) vocabularies, a machine-readable format. Compared to conventional digital archives, the knowledge graph enables users to retrieve a specific entity with its semantic information and discover its relationships with other entities. As a result, the knowledge graph can be used for semantic search and various intelligent services.

• Journal of the Korea Concrete Institute
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• v.22 no.1
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• pp.69-76
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• 2010

The majority of research that has been performed on cracking potential of concrete by shrinkage has assumed that concrete acts as a homogeneous material. However, with this approach, it is not able to evaluate the micro-cracking behavior in concrete due to autogenous shrinkage under unrestrained boundary condition (free boundary condition) nor to understand the cracking behavior properly because of the heterogeneous nature of concrete. To better understand the micro-cracking behavior of concrete induced by autogenous shrinkage, series of experiments were performed measuring the length change and acoustic emission energy. As an analytical approach, this research uses an object oriented finite element analysis code (OOF code) to simulate the behavior of the concrete on a meso-scale. The concrete images used in the simulations were directly obtained from mortar samples. From the experiments and simulation results, it was able to better understand the micro-cracking behaviour of concrete due to shrinking of paste phase and internal restraint by aggregates.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.2
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• pp.349-356
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• 2020

This paper introduces the implementation of a driver's condition warning system using eye aspect ratio to prevent a car accident. The proposed driver's condition warning system using eye aspect ratio consists of a camera, that is required to detect eyes, the Raspberrypie that processes information on eyes from the camera, buzzer and vibrator, that are required to warn the driver. In order to detect and recognize driver's eyes, the histogram of oriented gradients and face landmark estimation based on deep-learning are used. Initially the system calculates the eye aspect ratio of the driver from 6 coordinates around the eye and then gets each eye aspect ratio values when the eyes are opened and closed. These two different eye aspect ratio values are used to calculate the threshold value that is necessary to determine the eye state. Because the threshold value is adaptively determined according to the driver's eye aspect ratio, the system can use the optimal threshold value to determine the driver's condition. In addition, the system synthesizes an input image from the gray-scaled and LAB model images to operate in low lighting conditions.

• Journal of the Korean earth science society
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• v.24 no.3
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• pp.135-140
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• 2003

The purpose of this study is to assess pre-service elementary teacher's conceptions of environmental issues. 141 pre-service elementary teachers from local college participated in this study. We discovered that most of participants understood the possibility of technological abuse that could lead to environmental destruction. They also well understood the crisis of the Earth's ecosystem. Nevertheless, it seemed most of participants were not ready to take action to save ti. In addition, they also showed stereo-typically biased opinions about science, technology and their relationship with environmental issues. It appeared to come from media-oriented environmental education. Since pre-service teacher's conceptions could directly effect future education, it is necessary to establish a more systematic educational system for environmental education, for both pre-service teachers and students.