• Journal of Navigation and Port Research
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• v.42 no.3
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• pp.177-186
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• 2018

Designers need a lot of information to determine the principal dimensions in the initial stage of boat design, and most of the information they need can be obtained by investigating and analyzing similar existing boat data. In addition, the principal dimensions that are determined have an impact throughout the design process (basic/detailed design), which in turn leads directly to the stability and performance of the boat. Therefore, in this study, the initial design system for the boat (design support platform) was developed using a correlation analysis with existing data for more than 700 boats. It was confirmed that the designer could conveniently and reasonably derive and determine the principal dimensions for a boat in the initial design stage, for the 50ft-class of small and high-speed boats.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.419-424
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• 2012

This paper discusses the state-of-the-art techniques in real-time state estimation for the Smart Microgrids. The most popular method used in traditional power system state estimation is a Weighted Least Square(WLS) algorithm which is based on Maximum Likelihood(ML) estimation under the assumption of static system state being a set of deterministic variables. In this paper, we present a survey of dynamic state estimation techniques for Smart Microgrids based on Belief Propagation (BP) when the system state is a set of stochastic variables. The measurements are often too sparse to fulfill the system observability in the distribution network of microgrids. The BP algorithm calculates posterior distributions of the state variables for real-time sparse measurements. Smart Microgrids are modeled as a factor graph suitable for characterizing the linear correlations among the state variables. The state estimator performs the BP algorithm on the factor graph based the stochastic model. The factor graph model can integrate new models for solar and wind correlation. It provides the Smart Microgrids with a way of integrating the distributed renewable energy generation. Our study on Smart Microgrid state estimation can be extended to the estimation of unbalanced three phase distribution systems as well as the optimal placement of smart meters.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.3
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• pp.976-995
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• 2016

Workflow scheduling is one of the challenging problems in cloud computing, especially when service reliability is considered. To improve cloud service reliability, fault tolerance techniques such as fault recovery can be employed. Practically, fault recovery has impact on the performance of workflow scheduling. Such impact deserves detailed research. Only few research works on workflow scheduling consider fault recovery and its impact. In this paper, we investigate the problem of workflow scheduling in clouds, considering the probability that cloud resources may fail during execution. We formulate this problem as a multi-objective optimization model. The first optimization objective is to minimize the overall completion time and the second one is to minimize the overall execution cost. Based on the proposed optimization model, we develop a heuristic-based algorithm called Min-min based time and cost tradeoff (MTCT). We perform extensive simulations with four different real world scientific workflows to verify the validity of the proposed model and evaluate the performance of our algorithm. The results show that, as expected, fault recovery has significant impact on the two performance criteria, and the proposed MTCT algorithm is useful for real life workflow scheduling when both of the two optimization objectives are considered.

• The Korean Journal of Applied Statistics
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• v.26 no.4
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• pp.623-634
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• 2013

In this study, we provide empirical evidence of whether a spatial correlation among mode choices at the TAZ(Traffic Analysis Zone) level exists based on transit smart card data observed in Seoul, Korea. The results show that the areas with a higher probability that passengers choose to take a bus are clustered and that those regions have fewer metro stations than bus stations. We also found that the spatial correlation turned out to be statistically meaningful and provided an opportunity for the potential use of the spatial correlation in modeling mode choices. A reliable spatial interaction would constitute valuable information for transportation agencies in terms of their route planning and scheduling based on the transit smart card data.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.9
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• pp.77-84
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• 2013

There are lots of tries to make a combination between the technology development which is fast arisen and cultural phenomenon which imply in it. We called this research area as the cultural computing or cultural modeling. In this paper, we examine the cultural user interface design, especially cultural design structure based on the contents considering the research trend of the cultural modeling. To design of the contents based on the culture, there is a need to draw a structure of the cultural feature for the contents. To do this, we combine Hofstede's cultural dimensions model with the data of contents and then we suggest cultural index of content(CiCo). Furthermore, we draw national index of cultural content(NiCC), through conjoining CiCo with preference pattern of content consumption for the nations. Suggested CiCo and NiCC are based on Hofstede's model, however they are improved approximately 10% of the explanatory of model than the Hofstede's.

• Journal of Intelligence and Information Systems
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• v.14 no.4
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• pp.179-200
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• 2008

We develop a feature selection method that can improve both the efficiency and the effectiveness of classification technique. In this research, we employ case-based reasoning as a classification technique. Basically, this research integrates the two existing feature selection methods, i.e., the univariate analysis and the LVF algorithm. First, we sift some predictive features from the whole set of features using the univariate analysis. Then, we generate all possible subsets of features from these predictive features and measure the inconsistency rate of each subset using the LVF algorithm. Finally, the subset having the lowest inconsistency rate is selected as the best subset of features. We measure the performances of our feature selection method using the data obtained from UCI Machine Learning Repository, and compare them with those of existing methods. The number of selected features and the accuracy of our feature selection method are so satisfactory that the improvements both in efficiency and effectiveness are achieved.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.1
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• pp.65-72
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• 2012

With the development of MEMS, small and low-priced sensors integrating IMU and GPS have produced and exploited for diverse field. In this research, we have judged that MEMS-based IMU/GPS sensor is suitable for light-weighted mobile mapping system and carried out experiments to analyze the characteristics of MTi-G, which was developed from XSens company. From a sensor which fixed to dashboard, coordinates results with no post-processing were achieved for test area. On the whole, the results show satisfactory performances but some errors also were discovered from parts of the road due to sensor properties, XKF characteristics and GPS reception environment. We could confirm the potential of light-weighted mobile mapping system. Experiments considering various GPS reception environments and road condition and more detailed level of accuracy analysis will be performed for further research.

• Journal of Multimedia Information System
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• v.7 no.1
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• pp.87-96
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• 2020

Parents' desire for daily English practice for students and the urge for a etter English education has led to a demand for a highly qualified educational curriculum. In addition to getting deep-dive insights into parents' decision-making process, the increasingly important role of STEM education method has been proved in accordance with plenty of evidenced-based many of previous research. This study was conducted to examine the five independent factors affecting parents' intentions when designating English centers for their children, respectively named: Facility, Teachers, Brands, Social factors and Tuition. Through a preliminary approach, 235 samples were analyzed. Analysis of the sample responses reveals the importance level of five independent factors affecting Parents' intention to choose English centers in descending order: Facilities, Teachers, Brands, Tuition and Social factors. Furthermore, a positive correlation was found between STEM and Intention to choose English centers, indicating that whether the center applies STEM-related curriculum in English courses or not, in fact, has a significant impact on parents' decision. In terms of attitude towards STEM, further statistical tests revealed an interesting finding, which is the fact that how STEM affects Intention of parents is directly proportional to the Attitude towards STEM. With the help of SPSS 20 and AMOS 20, the SEM analysis was processed in order to draw conclusions about factors impacting Intentions to choose English centers. Combining with Multi-group analysis, the major role of STEM education has been assessed in relation to plenty of correlations. In light of recent major and massive growth of English teaching market in Vietnam, several suggestions and recommendations in terms of sustainable developments have been displayed in this research.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.5
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• pp.936-944
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• 2017

These days, research has been made for a variety of internet of things (IoT) technologies over industrial fields. The current research trend includes the effective adoption of the IoT technologies. But, most IoT researches assume a relatively complicated structure, which consists of sensor devices, gateway, network server, and application server. Of course, the structure has distinct merits in the aspects of flexibility and expandability. However, the complicated structure causes the system implementation overhead including high-cost implementation, and hinders the practical usage of IoT in the industry areas, which require a small-size network. In this paper, we propose a novel IoT system architecture, which guarantees the small-size network and the low-cost implementation. Also, we implement the infrastructure, which includes the RF433-based sensor network, the ARDUINO-YUN based gateway, and the application server using Apache/PHP/MySQL (APM) package. Finally, we present the effective power management scheme among these components.

• The Journal of the Korea Contents Association
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• v.11 no.11
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• pp.91-101
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• 2011

This research aims to suggest web-based 3D face modeling system for hairline modification surgery. As public interests in beauty regarding face escalate with era of wide persoanl mobile smart iCT devices, need for medical information system is urgent and increasing demand. This research attempted to build 3D facing modeling library deploying conventional technology and proprietary software available. Implications from the our experiment found that problems and requirement for developing new web based standard. We suggest new system from our experiment and literature review regarding relevant technologies. Main features of our suggested systems is based on studies regarding hair loss treatment such as medical science, beauty studies and information technology. This system processes input images of 2D frontal and profile pictures of face into 3D face modeling with mesh-data. The mesh data is compatible with web standard technology including SVG and Canvas Tag supported natively by HTML5.