• Communications for Statistical Applications and Methods
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• v.24 no.4
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• pp.383-396
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• 2017

The model in our approach assumes that computer responses are a realization of a Gaussian processes superimposed on a regression model called a Gaussian process regression model (GPRM). Selecting a subset of variables or building a good reduced model in classical regression is an important process to identify variables influential to responses and for further analysis such as prediction or classification. One reason to select some variables in the prediction aspect is to prevent the over-fitting or under-fitting to data. The same reasoning and approach can be applicable to GPRM. However, only a few works on the variable selection in GPRM were done. In this paper, we propose a new algorithm to build a good prediction model among some GPRMs. It is a post-work of the algorithm that includes the Welch method suggested by previous researchers. The proposed algorithms select some non-zero regression coefficients (${\beta}^{\prime}s$) using forward and backward methods along with the Lasso guided approach. During this process, the fixed were covariance parameters (${\theta}^{\prime}s$) that were pre-selected by the Welch algorithm. We illustrated the superiority of our proposed models over the Welch method and non-selection models using four test functions and one real data example. Future extensions are also discussed.

• Journal of Power Electronics
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• v.13 no.3
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• pp.419-428
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• 2013

The modular multilevel cascade converter (MMCC) is a new family of multilevel power converters with modular realization and a cascaded pattern for submodules. The MMCC family can be classified by basic configurations and submodule types. One member of this family, the Hexverter, is configured as Double-Delta Full-Bridge (DDFB). It is a novel multilevel AC/AC converter with direct power conversion and comparatively fewer required components. It is appropriate for connecting two three-phase systems with different frequencies and driving an AC motor directly from a utility grid. This paper presents the dq model of a Hexverter with both of its AC systems by state-space representation, which then simplifies the continuous time-varying model into a periodic discrete time-invariant one. Then a generalized multivariable optimal control strategy for regulating the Hexverter's independent currents is developed. The resulting control structure can be adapted to other MMCCs and is flexible enough to include other control criterion while guaranteeing the original controller performance. The modeling method and control design are verified by simulation results.

• Journal of Korean Society for Quality Management
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• v.13 no.2
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• pp.2-7
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• 1985

This paper introduces two approaches of the cost-oriented QC and the process-oriented QC, and compares them on several aspects. The cost-oriented QC tries to assure the specified quality level by sampling inspection within minimum quality cost, while the process-oriented QC aims at realization of target value of quality specification through process adjustment when a product deviates from the target. But the final purpose of both approaches is on quality assurance for markets and consumers. After all, desirability is a question of quality cost. This paper suggests two of cost functions for decision making criterion.

• Journal of Fashion Business
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• v.25 no.3
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• pp.51-70
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• 2021

The study aims to evaluate changes in textiles for automotive interior and suggest directions that the textile-development should take in order to achieve sustainability, and enter a circular economy system in the future. The main content and results of the study are as follows: First, we cover the overall sustainability study in the fashion and textile fields; in particular, the certification system is well established through the provision of information on the whereabouts of products to consumers and verification by external environmental auditors. Second, we considered the criteria of C2C in order to derive the necessary criteria for sustainability certification in the field of textiles. Third, we looked at the latest development trends of textile materials for automobile interiors which were divided into three categories: natural originated materials, circular economic consideration materials, and functional supplementary lightweight materials. In addition, we identified to what extent the trend of changes aggregated in the examples was satisfied and what was lacking when applied to the Basic criterion of C2C. As such, this study links and applies the sustainability criteria pursued in the fashion and textile fields to the textile for automotive interior materials, suggesting a direction for the textile field for automotive internal materials in the future. Based on the results of this study, it is hoped that studies on textiles for automotive interior considering the net economy will continue, and practical development in the industry will be realized.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.5
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• pp.109-120
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• 2017

It is important to estimate objectively in the driving test. Especially, the driving test is examined by totally driving ability, rule observation and situational judgement. For this, a grading automation system for driving test was presented by using GPS, sensor data and equipment operation informations. This system is composed of vehicle mounted module, automatic grading terminal, data controller, data storage and processing server. The vehicle mounted module gathters sensor data in the car. The terminal performs automatic grading using the received sensor data according the driving test criterion. To overcome the misposition of vehicle in the map due to GPS error, we proposed the automatic grading system by map matching method, path deviation and return algorithm. In the experimental results, it was possible to grade automatically, display the right position of the car, and return to the right path under 10 seconds when the vehicle was out of the shadow region of the GPS. This system can be also applied to the driving education.

• Archives of design research
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• v.19 no.4 s.66
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• pp.145-154
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• 2006

In today's brand apartment ads, the image of high-tech apartment seeking consumers' convenience thanks to the introduction of ubiquitous and the image of nature-friendly apartment stressing consumers' well-being life have become a main stream. However, it seems that there lacks differentiation in expressing ad images, except some brands. This may also be related to the matter of providing effective communication, which is the ultimate goal of advertisement. Therefore, to suggest the effective communication methods of brand apartment ads, this study semiologically translated first the images thai recent brand apartment ads present, and then in order to review whether these images are properly delivered to consumers, this study conducted the image survey for brand apartment ads with 123 subjects, who are the group of design professionals. As a result, the survey showed that, in the semiological translation of ad expression, meaning sharing is made when ad concept and ad image are semiologically consistent, and it showed that the realization of successful ad communication between advertisers and consumers is possible, which starts from this kind of meaning sharing. Based on the results of this study, we could know that the introduction of semiology into ad planning can be a logical judgment criterion to provide effective ad communication.

• Journal of Digital Convergence
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• v.8 no.3
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• pp.19-37
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• 2010

One of the core issues in the realization of e-government is the effective implementation of a website. The current trend of e-government is developing individual web sites and portals, covering such fields as education, tax, economics, real estate, travel, and health. Evaluating e-government web sites is essential for improving web sites. These principles can be included in usability in a broader concept. Website usability has attracted considerable research on website evaluation and has been regarded as one of the most important criteria for measuring and evaluating websites. Usable e-government web sites make citizens willing to search for helpful information or solve their civil applications. The objective of this paper is to suggest an Analytic Hierarchy Process (AHP) method for evaluating e-government web sites. The proposed AHP method has two special characteristics compared to general AHP approaches. First, all citizens who are e-government users can evaluate both the usability criteria and the web sites, but the weighting mechanism differs between criteria and web sites. Secondly, a pairwise comparison is time-consuming and not cost effective with many criteria. Therefore for evaluating a website with respect to a sub-criterion, we develop checklist items as measure scales with a seven-point rating. This method is efficient as it enable us to avoid the pairwise comparison mechanism between sub-criteria. A new computation procedure for the AHP is developed that combines and synthesizes priorities of portals in the case that two decision maker groups are involved.

• The Journal of the Korea Contents Association
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• v.6 no.8
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• pp.175-183
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• 2006

In computer graphics, according as the rapid development of hardware can realize high-resolution image on the monitor, the more natural and accurate rendering skill is needed gradually, and the studies about high-level rendering algorithm are processing. There are two types in rendering skill. The one is photo-realistic rendering to realize accurate image like photos and the other is real-time rendering to realize rapid real-time render. This paper includes caustics expression about lights and materials of several photo-realistic rendering skills. First this paper analyzes how caustics is used and expressed in movies, and further realizes caustics effect using real renderer. This paper examines objective criterion and capability of plug-in through the objective experiment of renderer. Also this paper analyzes using environment on variables for caustics effect realization. The experimental results can be applied to many rendering works as useful data, and can be used as data to understand characteristic and capability.

• Journal of Family Relations
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• v.22 no.1
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• pp.23-40
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• 2017

Objectives: The major purpose of the study is to examine structural relation among teenager's perception of parenting attitudes, peer attachment, resilience and meaning in life. In order to achieve purpose of the study, we will develop reliable criterion which can measure variable. Method: We will set up structural relational model from relationship between internal and external variables that can influence teenager's meaning in life and we will examine the relationship between variables through structural equation analysis. we will find structural relationship among parenting attitudes, peer attachment, resilience and meaning in life. Results: We analyzed structural relationship among variables targeting 744 middle school and high school students. Teenager's perception of parenting attitudes have positive influence on peer attachment. This shows that teenager perception of fostering attitude have a positive influence even though teenager percepts parent's foster attitude as overprotective or compassionate. However, if teenager percept fostering attitude as overprotective, teenager perception of parenting attitudes doesn't have influence on resilience. Parent's compassionate attitude not only directly influence resilience but also influence resilience through peer attachment. This validates that individual psychological factor, such as how teenager accept and interpret surrounding environment can influence resilience. Peer attachment relationship not only directly influence resilience but also influence meaning of life through resilience. The resilience has direct effect on meaning in life. Conclusions: When one of education goal is to help teenager to find meaning in life and to reach self-realization, We need to have interest in resilience which is known factor for contributing meaning in life. As previous teenager studies has approached this problem, such as maladjustment, delinquency, and depression, it is significant that this study is examined in positive a psychological perspective which focus on healthy adjustment, such as meaning in life based on teenager's resilience and happiness.

• Economic and Environmental Geology
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• v.50 no.3
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• pp.225-238
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• 2017

In this study, two viable measures of mean length and cumulative thickness of sand layers as important spatial statistics responsible for optimal SAGD (Steam Assisted Gravity Drainage) location for oil sand development were compared. For the comparisons, various deposits composed of sand and clay media were realized using a geostatistical simulator and the extent of steam chamber is simulated using multiphysics numerical simulator (dualphase flow and heat transfer). Based on the spatial statistics of each realization and the corresponding size of simulated steam chamber, the representativeness of two candidate measures (cumulative thickness and mean length of permeable media) were compared. The results of the geostatistical and SAGD simulations suggest that the mean length of permeable media is better correlated to the size of steam chamber than the cumulative thickness. Given those two-dimensional results, it is concluded that the cumulative thickness of the permeable media alone may not be a sufficient criterion for determining an optimal SAGD location and the mean length needs to be complementarily considered for the sound selections.