• Journal of Digital Convergence
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• v.13 no.10
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• pp.121-133
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• 2015

This tutorial presents an approach to perform the covariance based structural equation modeling using the R. For this purpose, the tutorial defines the criteria for the covariance based structural equation modeling by reviewing previous studies, and shows how to analyze the research model with an example using the "lavaan" which is the R package supporting the covariance based structural equation modeling. In this tutorial, a covariance-based structural equation modeling technique using the R and the R scripts targeting the example model were proposed as the results. This tutorial will be useful to start the study of the covariance based structural equation modeling for the researchers who first encounter the covariance based structural equation modeling and will provide the knowledge base for in-depth analysis through the covariance based structural equation modeling technique using R which is the integrated statistical software operating environment for the researchers familiar with the covariance based structural equation modeling.

• Journal of Korea Multimedia Society
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• v.15 no.6
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• pp.701-710
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• 2012

Retinitis Pigmentosa(RP) is a common hereditary disease. While they have been normally living, those who have this symptom feel frustration and pain by the damage of visual acuity. At the national level, the loss of the economic activity due to the reduction of economically active population will be also greater. There is an urgent need for the base study that can provide the clinical prognosis information of RP disease. In this study, we suggest that it is possible to predict prognosis through the pattern classification of RP data. Statistical processing results through statistical software like SPSS(Statistical Package for the Social Service) were mainly applied for the conventional study in data analysis. However, machine learning and automatic pattern classification was applied to this study. SVM(Support Vector Machine) and other various pattern classifiers were used for it. The proposed method confirmed the possibility of prognostic prediction based on the result of automatically classified RP data by SVM classifier.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.5
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• pp.1138-1146
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• 1990

A knowledge-based expert system has been developed implementing the ambiguous process of conceptual design of flywheels in earlier design stage to assist the selection of proper flywheel types and dimensions. Knowledge for the flywheel design consists of the rules for conventional as well as super flywheels and other informations required for the design process. Those knowledges were extracted from literatures and some experts in the field. With these knowledges, an integrated knowledge based expert system was developed to help users with informations and facilities to design flywheels interactively using a commercial package of knowledge-based system called INSIGHT2 of backward chaining and proprietary package of forward chaining written in LISP language. The developed system consists of the knowledge base part and calculation park : the first one consists of main module and user level modules and the other one is to assist in analyzing the stress distribution in the flywheels and deciding the flywheel dimensions and specifications for various types of flywheels using proper data bases and graphic facilities. With this flywheel design software, several examples were tried generating acceptable design results.

• The Journal of Fisheries Business Administration
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• v.40 no.2
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• pp.1-25
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• 2009

The major part of non-commercial food service is food service for school which has no any objective quality standards. Each school has different standard when they buy seafood for SFS(School Food Service). The research purpose is whether or not the extrinsic cues of the seafood such as price, the source origin, company image, safety standards, etc or the intrinsic cues such as fishy smell, the hardiness of fish meat, others have any effect on the seafood evaluation when school nutritionist purchase it, for more objective basis. The research method is distributing questionnaire survey through e-mail or directly visiting the schools from October 30 to November 9, 2007. The questionnaire was distributed to 70 nutritionists of food service for elementary school in Busan. Total 50 questionnaires are used as data in the statistical analysis using SPSS package software. The research results are; First, there is interaction effect between the extrinsic and intrinsic cues of seafood for SFS. That is when the school nutritionist valued on intrinsic cues of seafood such as a fishy smell, the hardiness of fish meat and etc influence on the extrinsic cues such as price, source origin, reliable circulation process, HACCP application, etc. Second, the extrinsic cues of the seafood give no effect on perceived quality. Since seafood for SFS are heavy buying, prearrangement contract and most of them using pre-treated frozen aquatics. Third, the intrinsic cues of the seafood give no effect on perceived quality. The extrinsic cues consist of 5 parts namely "opening about quality", "source origin", "company image", "safety/standards" and "price/package". However, "safety/standard" was the only affecting factor to perceive quality. The reason is that in fact they have no standards or any document proving the quality of the seafood unless safety standards factor. Last, the perceived quality is an important factor for perceived value and purchase intention. It is showed that there is a path to form a willing to buy through the perceived value after school nutritionist recognizes the perceived quality.

• The Transactions of the Korea Information Processing Society
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• v.6 no.7
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• pp.1884-1896
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• 1999

In this paper, we propose an ATM API for Java pplication programming. The proposed Java ATM API is an extended form of java.net package of the Java Core API. Our Java ATM API is defined based on the ATM Forum's semantic standard for native ATM services, "Native ATM Service : Semantic Description, Version 1.0". IN order to provide native ATM services, we defined several new classes within the java.net package, including AtmAddress for AtmAddress, AtmSocket, ATM BLLI and AtmBHLI for Atm BLLI and BHLI information, AtmServerSocket, AtmMulticastSocket, AtmSocketImpl for socket programming over native ATM communication, and AtmConnAttr for native ATM connection characteristics. Software structure for construcing the Java ATM API over Winsock 2 environment and its implementation method are also presented.

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.279-288
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• 2016

Stable Isotope Analysis(SIA) of carbon and nitrogen is useful tool for the understanding functional roles of target organisms in biological interactions in the food web. Recently, mixing model based on SIA is frequently used to determine which of the potential food sources predominantly assimilated by consumers, however, application of model is often limited and difficult for non-expert users of software. In the present study, we suggest easy manual of R software and package SIAR with example data regarding selective feeding of crustaceans dominated freshwater zooplankton community. We collected SIA data from the experimental mesocosms set up at the littoral area of eutrophic Chodae Reservoir, and analyzed the dominant crustacean species main food sources among small sized particulate organic matters (POM, <$50{\mu}m$), large sized POM (>$50{\mu}m$), and attached POM using mixing model. From the results obtained by SIAR model, Daphnia galeata and Ostracoda mainly consumed small sized POM while Simocephalus vetulus consumed both small and large sized POM simultaneously. Copepods collected from the reservoir showed no preferences on various food items, but in the mesocosm tanks, main food sources for the copepods was attached POM rather than planktonic preys including rotifers. The results have suggested that their roles as grazers in food web of eutrophicated reservoirs are different, and S. vetulus is more efficient grazer on wide range of food items such as large colony of phytoplankton and cyanobacteria during water bloom period.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.874-881
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• 2022

Until 2016, before discussions on the restoration of brackish water of the Nakdong River Estuary started in earnest, the downstream water level was predicted using the data of existing tide level observatories (Busan and Gadeokdo) several kilometers away from the estuary. However, it was not easy to carry out the prediction due to the dif erence in tide level and phase. Therefore, this study was conducted to estimate tide prediction more accurately through tidal harmonic analysis using the measured water level affected by the tides in the offshore waters adjacent to the Nakdong River Estuary. As a research method, the storage status of observation data according to the period and abnormal data were checked at 10-minute intervals in the offshore sea area near the Nakdong River Estuary bank, and the observed and predicted tides were measured using TASK2000 (Tidal Analysis Software Kit) Package, a tidal harmonic analysis program. Regression analysis based on one-to-one comparison showed that the correlation between the two components was high correlation coef icient 0.9334. In predicting the tides for the current year, if possible, more accurate data can be obtained by harmonically analyzing one-year tide observation data from the previous year and performing tide prediction using the obtained harmonic constant. Based on this method, the predicted tide for 2022 was generated and it is being used in the calculation of seawater inflow for the restoration of brackish water of the Nakdong River Estuary.

• Imaging Science in Dentistry
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• v.50 no.2
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• pp.161-168
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• 2020

Purpose: The aim of this study was to evaluate the influence of voxel size and different post-processing algorithms on the analysis of dental materials using micro-computed tomography (micro-CT). Materials and Methods: Root-end cavities were prepared in extracted maxillary premolars, filled with mineral trioxide aggregate (MTA), Biodentine, and Intermediate Restorative Material (IRM), and scanned using micro-CT. The volume and porosity of materials were evaluated and compared using voxel sizes of 5, 10, and 20 ㎛, as well as different software tools(post-processing algorithms). The CTAn or MeVisLab/Materialise 3-matic software package was used to perform volume and morphological analyses, and the CTAn or MeVisLab/Amira software was used to evaluate porosity. Data were analyzed using 1-way ANOVA and the Tukey test(P<0.05). Results: Using MeVisLab/Materialise 3-matic, a consistent tendency was observed for volume to increase at larger voxel sizes. CTAn showed higher volumes for MTA and IRM at 20 ㎛. Using CTAn, porosity values decreased as voxel size increased, with statistically significant differences for all materials. MeVisLab/Amira showed a difference for MTA and IRM at 5 ㎛, and for Biodentine at 20 ㎛. Significant differences in volume and porosity were observed in all software packages for Biodentine across all voxel sizes. Conclusion: Some differences in volume and porosity were found according to voxel size, image-processing software, and the radiopacity of the material. Consistent protocols are needed for research evaluating dental materials.

• Korean Journal of Poultry Science
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• v.23 no.4
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• pp.209-219
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• 1996

This research was carried out to get the basic information on the current situation of personal computer utilization for poultry farm management, and the results obtained could be used in developing of the software system for the poultry farm management. Survey method by interview and mail was adopted to carry out the research, and the total number of data used to statistical analyses was k6 poultry farmers. 1. The ratio of the poultry farmers who had the personal computer(P/C) was about 25%, and the most of the layer farmers from age 30 to 40 who manage the flock size 20,000 or above had the P/C. 2. About 70% of the farmers who had P/C have bought the system after 1993, and 83% of those farmers had the P/C-486 or above level system. They bought the P/C with intent to apply it to farm management(39%) and education for children(31%). 3. About 50% of the farmers who had P/C obtained the relevant knowledge for operating computer system by themselves, and the 33% of the P/C-possessed farmers used P/C for word-processor. 4. About 35% of the farmers who had P/C applied their system to analyse the management analyses, and the sarne ratio of the farmers answered that they didn't apply the system to their farm management. 5. About 25% of the farmers who had P/C used package software, and the company which installed the automated cage system offered the software. 6. Most of the farmers considered the computerization of the farm management positively, and they answered that they will apply P/C to their management actively from now on. 7. About 56% of the farmers didn't think that they had sufficient knowledge for operating computer system, and a quarter of them pointed that the difficulty of the buying software for poultry farm management was the most biggest problem to spread out the computerization in the poultry farm. 8. Most of the poultry farmers didn't buy P/C because they didn't have the relevant knowledge for computer system, but they wanted to learn basic knowledge for computer, and they had the intention to apply computer to their management positively. In order to expand the computerization for poultry farm management, appropriate education system for the farmers from age 30 to 40 who manage the flock size 20,000 or above and the development of the software that could be applied to poultry farm management on the spot efficiently should be made.

• The KIPS Transactions:PartA
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• v.13A no.1 s.98
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• pp.45-52
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• 2006

To perform on-line maintenance for Distributed Information System, it is indispensable to disseminate files to participant nodes in the network. When users' requests for file deployment occur simultaneously in a short period a deployment server falls into overload phase, which is often called Flash Crowds. h common solution to avoid Flash Crowds is to increase hardware capacity. In this paper, we propose a software solution based on P2P, which does not cost any additional expense. In the proposed solution, nodes in the network are grouped into subnetworks one of which is composed of only neighboring nodes. In each subnetwork, copies of deployment files can be transferred to each other. Consequently, it brings about the effect of load balancing in deployment server. To raise the effectiveness, target files for deployment are packed into one package. Before being transferred, each package is divided into multiple equal-sized segments. A deployment server in a normal phase transmits a package requested from nodes in segment units. However a deployment server is overloaded, if segments already exist in the subnetwork participant nodes in the subnetwork receive necessary segments from neighboring nodes. In this paper, we propose data structures and algorithm for this approach and show performance improvement through simulation.