• Steel and Composite Structures
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• v.24 no.2
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• pp.227-237
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• 2017

This paper presents optimization of a long-span portal steel frame under dynamic wind loads using a surrogate-assisted evolutionary algorithm. Long-span portal steel frames are often used in low-rise industrial and commercial buildings. The structure needs be able to resist the wind loads, and at the same time it should be as light as possible in order to be cost-effective. In this work, numerical model of a portal steel frame is constructed using structural analysis program (SAP2000), with the web-heights at five locations of I-sections of the columns and rafters as the decision variables. In order to evaluate the performance of a given design under dynamic wind loading, the equivalent static wind load (ESWL) is obtained from a database of wind pressures measured in wind tunnel tests. A modified formulation of the problem compared to the one available in the literature is also presented, considering additional design constraints for practicality. Evolutionary algorithms (EA) are often used to solve such non-linear, black-box problems, but when each design evaluation is computationally expensive (e.g., in this case a SAP2000 simulation), the time taken for optimization using EAs becomes untenable. To overcome this challenge, we employ a surrogate-assisted evolutionary algorithm (SAEA) to expedite the convergence towards the optimum design. The presented SAEA uses multiple spatially distributed surrogate models to approximate the simulations more accurately in lieu of commonly used single global surrogate models. Through rigorous numerical experiments, improvements in results and time savings obtained using SAEA over EA are demonstrated.

• The KIPS Transactions:PartD
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• v.10D no.3
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• pp.387-398
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• 2003

Materialized views have received much attention for query performance improvement. They need to be refreshed whenever their underlying data sources are updated. They could be recomputed from scratch or they could be incrementally refreshed by reflecting only those portions of updates that affect them. With emergence of XML as the standard for data exchange on the Web, active research is under way on effectively storing and retrieving XML documents. In this paper, we describe a performance study on the incremental refresh of XML materialized views for the case where XML documents are stored in a relational DBMS, and XML materialized views are maintained with incremental refresh. We describe implementation of a prototype XML storage system that supports XML materialized views and their incremental refresh, and report the performance results obtained with the implemented system through a detailed set of experiments on the incremental refresh of XML materialized views. The results show that the XML view maintenance with incremental refresh outperforms the ordinary view recomputation.

• The KIPS Transactions:PartD
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• v.12D no.2 s.98
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• pp.199-210
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• 2005

We need XML generate various kinds of XML data to evaluate XML database systems. Existing XML data generators are developed to generate XML data that are suitable for particular evaluation methods, and their functionalities are limited in terms of generating XML data This paper introduces a new XML data generator, WeXGene, that not only improves the drawbacks of existing data generators but also adds new data generation functionalities. For generating XML data WeXGene uses the user data files and the structure definition files, which specify SDTD(Symbolic DTD) or input parameters. The user data file is a text data file that has column data or row data. It is also possible that WeXGene generates XML data without accessing the user data file. This paper presents the design details, overall system architecture, and data generation process of WeXGene. An analytic comparison with other XML data generators is also presented.

• The KIPS Transactions:PartA
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• v.18A no.4
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• pp.129-134
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• 2011

E-learning in Korea supports different educational needs of diverse learners. E-learning became one of the major source of educational services for schools, higher education, lifelong learning, and for special education. Many e-learning contents offered by cyber universities use HTML, CSS, and Flash, and these are known to have limitations on accessibilities. People with disabilities or aged have problems accessing such contents. The purpose of this study is to evaluate accessibility of Flash e-learning contents offered by 9 cyber universities. AccChecker is used to assess accessibility of the contents. The result shows many errors and warning with Text Equivalents, Keyboard Navigation, Properties, Depth of Tree, and Structures that restrict access. In order to improve the quality and expansion of quality e-learning contents, we need aggressive measures to obtain accessibility of contents, and these should be designed at the planning phase rather than adjusted during the development stage. Furthermore, it is vital to train instructional designers, developers and the CEOs to realize the importance of accessibility and learn appropriate skills to increase accessibilities of e-learning contents.

• Journal of Korean Society on Water Environment
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• v.32 no.1
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• pp.89-97
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• 2016

Digital Elevation Models (DEMs) have been used to represent the effects of topography on soil erosion. A DEM of 30 m resolution is frequently used in hydrology and soil erosion studies because the National Water Management Information System (WAMIS) provides a 30 m resolution DEM at national scale on its web site. However, the Ministry of Environment recommends the use of a DEM with 10 m resolution for evaluation of soil erosion due to the fact that soil erosion estimation is to some degree affected by the spatial resolution of DEM. In this regard, a DEM with 5 m resolution was resampled for 10 × 10 m, 20 × 20 m, 30 × 30 m, 50 × 50 m, 70 × 70 m, and 100 × 100 m resolutions, respectively. USLE LS factors and soil erosion values were evaluated using these datasets. Use of a DEM with at least 30 m resolution provided reasonable LS factors and soil erosion values at a watershed.

• Journal of Digital Contents Society
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• v.15 no.4
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• pp.559-568
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• 2014

Previous polarity classification using sentiment analysis utilizes a sentence rule by product reviews based rating points. It is difficult to be applied to blogs which have not rating of product reviews and is possible to fabricate product reviews by comment part-timers and managers who use web site so it is not easy to understand a product and store reviews which are reliability. Considering to these problems, if we analyze blogs which have personal and frank opinions and classify polarity, it is possible to understand rightly opinions for the product, store. This paper suggests that we extract high frequency vocabularies in blogs by several domains and choose topic words. Then we apply a technique of sentiment analysis and classify polarity about contents of blogs. To evaluate performances of sentiment analysis, we utilize the measurement index that use Precision, Recall, F-Score in an information retrieval field. In a result of evaluation, using suggested sentiment analysis is the better performances to classify polarity than previous techniques of using the sentence rule based product reviews.

• The KIPS Transactions:PartD
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• v.9D no.6
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• pp.999-1008
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• 2002

XML is emerging as a standard data format to exchange and to present data on the Web. There are increasing needs to efficiently store and to query XML data. In this paper. we propose a new schema transformation algorithm based on a common structure extracting technique from XML documents. The common structure is shared by all XML documents referenced by DTD and the uncommon structure is ununiformly appeared on all XML documents referenced by DTD. Based on the extracted common and uncommon structures, we transform XML DTD into relational database schema. We conduct a performance evaluation based on the number of the generated tables, the size of the record, query processing time and the number of joins on the query. The performance of our algorithm is compared with the existing algorithms, then in most cates, our algorithm is better than the existing ones with respect to the number of the generated tables and appearance of NULL values in the tables.

• Clinical and Experimental Pediatrics
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• v.63 no.2
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• pp.34-43
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• 2020

Phenylketonuria is a disease caused by congenital defects in phenylalanine metabolism that leads to irreversible nerve cell damage. However, its detection in the early days of life can reduce its severity. Thus, many countries have started disease screening programs for neonates. The present study aimed to determine the worldwide prevalence of classic phenylketonuria using the data of neonatal screening studies.The PubMed, Web of Sciences, Sciences Direct, ProQuest, and Scopus databases were searched for related articles. Article quality was evaluated using the Joanna Briggs Institute Critical Appraisal Evaluation Checklist. A random effect was used to calculate the pooled prevalence, and a phenylketonuria prevalence per 100,000 neonates was reported. A total of 53 studies with 119,152,905 participants conducted in 1964-2017 were included in this systematic review. The highest prevalence (38.13) was reported in Turkey, while the lowest (0.3) in Thailand. A total of 46 studies were entered into the meta-analysis for pooled prevalence estimation. The overall worldwide prevalence of the disease is 6.002 per 100,000 neonates (95% confidence interval, 5.07-6.93). The meta-regression test showed high heterogeneity in the worldwide disease prevalence (I²=99%). Heterogeneity in the worldwide prevalence of phenylketonuria is high, possibly due to differences in factors affecting the disease, such as consanguineous marriages and genetic reserves in different countries, study performance, diagnostic tests, cutoff points, and sample size.

• Journal of Korean Society of Archives and Records Management
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• v.20 no.1
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• pp.69-87
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• 2020

For the long-term preservation of document-type electronic records, the National Archives of Korea has chosen PDF/A-1 as the preservation format named as the document file format, and established it as a public standard. The only option of selecting PDF/A-1 restricts the use of various electronic file formats that can or must be applied to actual works as IT advances and tasks change. Moreover, it is difficult to apply PDF/A-1 to other types of electronic records (administrative information datasets, audiovisual records, web records, etc.). Therefore, it is necessary to diversify the preservation formats of electronic records. We suggest a framework for selecting various preservation formats. Furthermore, we propose common criteria and evaluation methods frequently applied to all electronic records when selecting a preservation format, and introduce a methodology for deriving intrinsic criteria applied to each type of electronic records.

• Korean Journal of Community Nutrition
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• v.17 no.2
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• pp.194-204
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• 2012

The purpose of this study was to investigate school dietitians' satisfaction with and needs for School Meal Service Support Centers. A web-based on-line survey was conducted with 1,102 nutrition teachers or school dietitians using four School Meal Service Support Centers during the summer of 2011. The data from 578 respondents (52.5%), consisting of 165 (44.4%), 334 (53.4%), 41 (67.2%), and 38 (86.4%) dietitians using Seoul, Gyeonggi, Suncheon and Gyeongju centers, respectively, were analyzed. The main reason for using the centers was subsidies from local governments. The dietitians using the metropolitan centers, which were Seoul and Gyeonggi centers, tended to buy agricultural products through the centers only, and those using local centers, which were Suncehon and Gyeongju centers, bought those products from the private suppliers as well as from the centers. The dietitians' overall level of satisfaction with the centers was not high showing 3.3 out of 5 points; it was significantly associated with the operating system and services of the centers such as system efficiency, delivery accuracy, communication, and information provision rather than the agricultural products provided by the centers. The dietitians preferred joint operation of the centers by local governments and producers' groups. They wanted School Meal Service Support Centers to be evaluated every year. It was suggested that efforts should be made to improve the operation system and service of School Meal Service Support Centers for improving dietitians' satisfaction with the centers. In addition, an evaluation system for School Meal Service Support Centers should be implemented soon based on school dietitians' needs.