• ETRI Journal
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• v.27 no.6
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• pp.747-758
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• 2005

The problem of selection among competing models has been a fundamental issue in statistical data analysis. Good fits to data can be misleading since they can result from properties of the model that have nothing to do with it being a close approximation to the source distribution of interest (for example, overfitting). In this study we focus on the preference among models from a family of polynomial regressors. Three decades of research has spawned a number of plausible techniques for the selection of models, namely, Akaike's Finite Prediction Error (FPE) and Information Criterion (AIC), Schwartz's criterion (SCH), Generalized Cross Validation (GCV), Wallace's Minimum Message Length (MML), Minimum Description Length (MDL), and Vapnik's Structural Risk Minimization (SRM). The fundamental similarity between all these principles is their attempt to define an appropriate balance between the complexity of models and their ability to explain the data. This paper presents an empirical study of the above principles in the context of model selection, where the models under consideration are univariate polynomials. The paper includes a detailed empirical evaluation of the model selection methods on six target functions, with varying sample sizes and added Gaussian noise. The results from the study appear to provide strong evidence in support of the MML- and SRM- based methods over the other standard approaches (FPE, AIC, SCH and GCV).

• Korean Journal of Occupational Health Nursing
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• v.17 no.1
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• pp.96-105
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• 2008

Purpose: The purpose of this study was to analyze alcohol drinking cessation programs to promote health status for workers on worksites. Method: Data were collected from the excellent 10 cases which were selected from "competition of health promotion programs on worksites" from 1999 to 2007 held by Korean Occupational Safety and Health Agency. Result: There were three main alcohol drinking cessation programs on worksites: health education, individual health services to change life style, and formation of supportive environments. Health education and individual health services were intervened in nine worksites. Building supportive environments for alcohol drinking cessation were implemented in 10 worksites. The most popular indicators for program evaluation were health diagnosis and percentage of alcohol drinkers. Problems to implement alcohol drinking cessation programs were low voluntary participation of labors, difficulty of applying programs to labors that had a shift duty, and complexity to evaluate the effectiveness of alcohol cessation programs due to deficits of standard instruments. Conclusion: These findings suggest that many worksites did not have alcohol drinking cessation programs and also these programs were not implemented effectively. Thus, employers, professionals and policy makers of occupational health should develop and support effective alcohol drinking cessation programs for l workers on worksites.

• Computers and Concrete
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• v.2 no.6
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• pp.439-454
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• 2005

When deterioration of concrete is observed in a structure, it is highly desirable to determine the cause of such deterioration. Only by understanding the cause can an appropriate repair strategy be implemented to address both the cause and the symptom. In colder climates, bridge deck deterioration is often caused by chlorides from de-icing salts, which penetrate the concrete and depassivate the embedded reinforcement, causing corrosion. Bridge decks can also suffer from other deterioration mechanisms, such as alkali-silica reaction, freeze-thaw, and shrinkage. There is a need for a comprehensive and integrative system to help with the inspection and evaluation of concrete bridge deck deterioration before decisions are made on the best way to repair it. The purpose of this research was to develop a model to help with the diagnosis of concrete bridge deck deterioration that integrates the symptoms observed during an inspection, various deterioration mechanisms, and the probability of their occurrence given the available data. The model displays the diagnosis result as the probability that one of four deterioration mechanisms, namely shrinkage, corrosion of reinforcement, freeze-thaw and alkali-silica reaction, is at fault. Sensitivity analysis was performed to determine which probabilities in the model require refinement. Two case studies are included in this investigation.

• Journal of the Korean Society for Library and Information Science
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• v.50 no.1
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• pp.209-233
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• 2016

The purpose of this study is to examine users' perceived importance for service attributes and performance in research libraries, and further to suggest the improvement strategies for research libraries. The survey was conducted for the library users of 14 government-funded research institutes. The questionnaire for this research was developed from the standard LibQUAL+. Statistical analyses were conducted to identify the relationship between service quality and users' satisfaction, and the gap between perceived importance and performance by user groups. According to the result of statistical analyses, the priority of service improvement strategies of research libraries were suggested.

• Korean Journal of Remote Sensing
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• v.31 no.1
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• pp.1-9
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• 2015

Mobility and cloud platform have become the dominant paradigm to develop web services dealing with huge and diverse digital contents for scientific solution or engineering application. These two trends are technically combined into mobile cloud computing environment taking beneficial points from each. The intention of this study is to design and implement a mobile cloud application for remotely sensed image fusion for the further practical geo-based mobile services. In this implementation, the system architecture consists of two parts: mobile web client and cloud application server. Mobile web client is for user interface regarding image fusion application processing and image visualization and for mobile web service of data listing and browsing. Cloud application server works on OpenStack, open source cloud platform. In this part, three server instances are generated as web server instance, tiling server instance, and fusion server instance. With metadata browsing of the processing data, image fusion by Bayesian approach is performed using functions within Orfeo Toolbox (OTB), open source remote sensing library. In addition, similarity of fused images with respect to input image set is estimated by histogram distance metrics. This result can be used as the reference criterion for user parameter choice on Bayesian image fusion. It is thought that the implementation strategy for mobile cloud application based on full open sources provides good points for a mobile service supporting specific remote sensing functions, besides image fusion schemes, by user demands to expand remote sensing application fields.

• Journal of the Korean Institute of Landscape Architecture
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• v.23 no.1
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• pp.175-188
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• 1995

Most of studies about Taegni-Ji were searched in the field of geography and history. These are relrealed the conflictin respects of the structure and contents of Taegni-Ji. This study reviewed these studies and searched for limits and inquiries. Thus the parts of overlooking in them were dealt with and interpretated in terms of the characters of the contents and structure of Taegni-Ji. This book is regarded as the subjects of traditional evaluation of landscape. Tractional landscapes were related to Pung-su in many sides. So the contents specialty related to Pung-su which refered used in Taegni-Ji were discussed through the system of Taegni-Ji. As a result the terms of Pung-su used in Taegni-Ji must be researched which were specific term or not. Those studies are bibliographical review. Taegni-Ji contains of many apparent view of rural landscape thug they will be carried to field survey. Research in this area is at an early stage. The Present stuffy was confined to an examination of the characteristics and transformation process of the location of seowons However, it is hoped that this study will offer meaningful guide for further research.

• International Journal of Aeronautical and Space Sciences
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• v.13 no.1
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• pp.64-73
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• 2012

Pointing stability of high precision observation satellites must satisfy the stringent requirements to perform at a designed level. As even a small vibrational disturbance can result in severe degradation of the optical performance, the effects of inorbit vibrational environment on the performance of optical payload must be predicted and analyzed in the design phase in order to ensure that the requirements imposed on the payload are fully met. In this paper, an integrated framework for the evaluation of the performance of optical payloads is developed. The developed simulation tool comprises of the reaction wheel induced disturbance model, state space model of a structure in modal form and Cassegrain reflector model. The performance degradation of the optical system due to jitter is expressed by using modulation transfer function (MTF) and image simulation. Moreover, vibration isolator model is also added to show the effectiveness of using a vibration isolator for the elimination of the effects of jitter in the acquisition of an image.

• Journal of the Korean Society of Food Culture
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• v.34 no.5
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• pp.629-636
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• 2019

This study examined the quality characteristics of jelly prepared with green grape juice (GJ). The pH, $^{\circ}Brix$ value, color, texture, and sensory evaluation of the jelly were measured. The pH of the jelly significantly decreased with increasing amount of GJ over the range of 3.25-5.27. The $^{\circ}Brix$ value of the jelly showed a significantly higher result as the amount of GJ increased (p<0.001). Lightness (L) and redness (a) decreased with increasing amount of GJ, and yellowness (b) increased. In the texture measurement, the GJ-100 sample group with a high substitute rate of GJ showed high hardness, gumminess, and chewiness (p<0.001). The results of principal component analysis (PCA) showed that the sample groups with high GJ content were classified as having relatively strong yellowness, sweet aroma, metallic aroma, grassy aroma, sweetness, sourness, green grape skin taste, and astringency. In the acceptance test, the GJ-50 sample group was evaluated to be high in flavor (p<0.001) and overall acceptance (p<0.01). However, sample groups consisting of 50% or more GJ were evaluated to be significantly strong in terms of astringency. Therefore, further study needs to be conducted about improving astringency in the future.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.111-114
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• 2013

Underground construction requires long construction duration and a variety of equipment, and environmental management and improvement of its activities are considered necessary. For the purpose of the environmental improvement of underground construction activities, the appropriate development of technologies to reduce generated pollutants is mandatory. However, the analysis of the needs of technology development and the evaluation of development priorities should take precedence. In this research, the needs for the improvement of each construction activity are analyzed as a preliminary study for a proposed technology development plan to improve the environmental performance of underground construction. Firstly, environmental problem factors caused by underground construction activities are determined while underground construction types, methods, and activities are classified. A questionnaire survey to determine the needs for the improvement of each activity is then carried out. The survey indicated that the most urgent activity to be improved is that of cutting excavation, which causes environmental problems associated with flying dust. This study could be used as a basis for a technology development plan for the environmental improvement of underground construction activities. The result of this study, the priority of improvement needs, contributes to the effective allocation of a limited Research and Development (R&D) budget.

• Journal of the Korean GEO-environmental Society
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• v.5 no.3
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• pp.61-70
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• 2004

N-value by the SPT is one of the key parameter for settlement evaluation. However, if the ground is firm, the usual N-value is not blow count of 30cm depth penetration. In such case, if N-value is more than 50 with 30cm penetration, the N-value 50 is applied for settlement analysis. Therefore, in this study, the modified method of N-value estimation is suggested and compared the settlement by Elastic Theory, and the measured field data by Plate Load Test. As the result of this study, it is shown that the settlement by Elastic Theory with the modified N-value is more accurate than settlement by usual N-value. The application of Elastic Theory for pure sand is also evaluated in this paper.