• Journal of applied mathematics & informatics
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• v.8 no.2
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• pp.305-326
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• 2001

We introduce a class of multilevel recursive incomplete LU preconditioning techniques (RILUM) for solving general sparse matrices. This techniques is based on a recursive two by two block incomplete LU factorization on the coefficient martix. The coarse level system is constructed as an (approximate) Schur complement. A dynamic preconditioner is obtained by solving the Schur complement matrix approximately. The novelty of the proposed techniques is to solve the Schur complement matrix by a preconditioned Krylov subspace method. Such a reduction process is repeated to yield a multilevel recursive preconditioner.

• Journal of the speleological society of Korea
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• no.5
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• pp.79-95
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• 1997

The main purpose of this article is to compare different mapping techniques, so that an appropriate one may be chosen for a particular cave. Ultra-accurate techniques such as using tripods are not discussed here, as their application is limited to a small minority of caves. Most modem mapping is carried out under time restraints, due to the shortness of an expedition or the difficulty of a cave; thus, rapid mapping techniques are emphasized here.(omitted)

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.1
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• pp.91-103
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• 2010

This paper introduces efficient rule-based semantic search techniques to ontology-based knowledge commerce services. Primarily, the search techniques presented in this paper define rules of reasoning that are required for users to search using the concept of ontology, multiple characteristics, relations among concepts and data type. In addition, based on the defined rules, the rule-based reasoning techniques search ontology for knowledge commerce services. This paper explains the conversion rules of query which convert user's query language into semantic search words, and transitivity rules which enable users to search related tags, knowledge products and users. Rule-based sematic search techniques are also presented; these techniques comprise knowledge search modules that search ontology using validity examination of queries, query conversion modules for standardization and expansion of search words and rule-based reasoning. The techniques described in this paper can be applied to sematic knowledge search systems using tags, since transitivity reasoning, which uses tags, knowledge products, and relations among people, is possible. In addition, as related users can be searched using related tags, the techniques can also be employed to establish collaboration models or semantic communities.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.3
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• pp.1348-1375
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• 2018

Support Vector Machine (SVM) is a well-known machine learning classification algorithm, which has been widely applied to many data mining problems, with good accuracy. However, SVM classification speed decreases with increase in dataset size. Some applications, like video surveillance and intrusion detection, requires a classifier to be trained very quickly, and on large datasets. Hence, this paper introduces two filter-based instance selection techniques for optimizing SVM training speed. Fast classification is often achieved at the expense of classification accuracy, and some applications, such as phishing and spam email classifiers, are very sensitive to slight drop in classification accuracy. Hence, this paper also introduces two wrapper-based instance selection techniques for improving SVM predictive accuracy and training speed. The wrapper and filter based techniques are inspired by Cuckoo Search Algorithm and Bat Algorithm. The proposed techniques are validated on three popular e-fraud types: credit card fraud, spam email and phishing email. In addition, the proposed techniques are validated on 20 other datasets provided by UCI data repository. Moreover, statistical analysis is performed and experimental results reveals that the filter-based and wrapper-based techniques significantly improved SVM classification speed. Also, results reveal that the wrapper-based techniques improved SVM predictive accuracy in most cases.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.3
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• pp.256-265
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• 2016

Software based fault tolerance techniques are designed to allow a system to tolerate software faults in the system. Fault tolerance techniques are divided into two groups : software based fault tolerance techniques and hardware based fault tolerance techniques. We need a proper design method according to characteristics of the system. In this paper, the concepts of software based fault tolerance techniques for Dual Flight Control Computer are described. For software based fault tolerance design, we classified software failure, designed a way for failure detection and the way of recovery. Eventually the effectiveness of software based fault tolerance techniques was verified through the Software Test Environment(STE).

• PNF and Movement
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• v.10 no.2
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• pp.1-8
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• 2012

Purpose : The purpose of study was aimed to identify whether the painless dynamic PNF techniques makes any differences in reducing lymphedema by applying this technique to lymphedema patients, and to provide the basic reference data for the purpose of applying to lymphedema patients. Methods : A total of 40 women participated in this study, and they did PNF techniques before applying lymph compression bandages. Group 1 of 20 subjects performed PNF techniques three times a week with 30 minutes each time. Group 2 of 20 subjects only practiced edema reducing massaging for 30 minutes. Results : In addition, the interaction between treatment method and treatment time was significant (p<.0001), which indicates that the changes in edema rates by measurement times appear differently according to treatment methods. In this study, it means that the 'PNF techniques' group has a steeper slope of decline than the 'message' group. Conclusion : In conclusion, both massaging and PNF techniques helped to lower edema rates. Four weeks after the beginning of treatment, PNF techniques was exhibited as generating a large degree of decline in edema rates than massaging.

• Journal of the Korean Society of Earth Science Education
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• v.7 no.1
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• pp.34-42
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• 2014

The purpose of this study was to examine the effects on the effects of science lessons using six thinking hats techniques on creativity and science academic achievement. To verify the research problem, the subject of this study was fourth-grade students selected from four classes of an elementary school located in Busan. For ten weeks, the experimental group of 40 students was taught using the six thinking hats techniques. The comparative group also of 40 students, was taught in normal classes which used a Text-book. Children were given a creativity test and academic achievement test in science to measure the effects on six thinking hats techniques. Likert scales were used to gather students feedbacks on creativity and science academic achievement. Through these procedures, the following results were obtained: First, the six thinking hats techniques had a more effect on creativity than the normal classes, where a text-book was used. Second, the six thinking hats techniques could be seen to be effective in improving the student's academic achievements in science than the normal classes which used a Text-book. Third, the result of the student recognition investigation, we could know that the students showed lots of interest in the science lessons using six thinking hats techniques, and they were able to understand the scientific theories. As a result, the elementary science class with six thinking hats techniques had the effects of developing creativity and science academic achievement. It means the science class with six thinking hats techniques has potential possibilities and value to develop creativity and science academic achievement.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.2
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• pp.88-95
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• 2009

There are many assessment techniques used for occupational risk factors of MSDs in the workplaces. However, because all ergonomic assesment techniques or tools are based on theoretical background derived from workphysiology, biomechanics, psychophysics, industrial hygiene, work system, and etc, it is impossible to compare the assessment techniques. This study was conducted to compare the excess rates of risk factors among ergonomic assessment techniques and to make alternative methods. Site-visits to 6 automobile products and parts company provided data for process repeated work where the produced data was examined for evaluating the relationship between workplace lay-out and work posture by using ergonomic assessment techniques. We evaluated 157 jobs for simple repeated work and 37 jobs for manual materials handling (MMH). In simple repeated work, the exceeded rates of AC were 36.3% in OWAS method and 93.0% in RULA method. The exceeded rate for RULA method was significantly higher than those for OWAS method (p<0.05). In MMH, the exceeded rates of AC were 80.0% in NLE method and 76.5% in WAC method. Statistically significant differences were not identified in the exceeded rates for NLE and MAC methods (p<0.05). The analyzed results among ergonomic assessment techniques (OWAS, RULA, NLE/WAC) were applied to the same work places performing simple repeated work and manual materials handling simultaneously. The applied results showed statistically significant differences (p<0.05) among ergonomic assessment techniques (OWAS, RULA, NLE/WAC). Exceeded rates of four ergonomic assessment techniques in decreasing order was "RULA>NLE>WAC>OWAS". The RULA method was the strongest assessment technique for automobile products and parts company. We discovered that the results could easily be overestimated or underestimated when the ergonomic assessment techniques were not applied correctly during the evaluation process. Therefore, we recommend using at least 2 methods when evaluating and analysing the results.

• Korean Journal of Heritage: History & Science
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• v.48 no.2
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• pp.142-157
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• 2015

This study examines how traditional knowledge functions in the specific techniques to make pottery in terms of the traditional knowledge on the pottery techniques of Onggi potters. It focuses on how traditional pottery manufacturing skills are categorized and what aspects are observed with regard to the techniques. The pottery manufacturing process is divided into the preparation step of raw material, the molding step of pottery, and the final plasticity step. Each step involves unique traditional knowledge. The preparation step mainly comprises the knowledge on different kinds of mud. The knowledge is about the colors and properties of mud, the information on the regional distribution of quality mud, and the techniques to optimize mud for pottery manufacturing. The molding step mainly involves the structure and shape of spinning wheels, the techniques to accumulate mud, ways to use different kinds of tools, the techniques to dry processed pottery. The plasticity step involves the knowledge on kilns and the scheme to build kilns, the skills to stack pottery inside of the kilns, the knowledge on firewood and efficient ways of wood burning, the discrimination of different kinds of fire and the techniques to stoke the kilns. These different kinds of knowledge may be roughly divided into three categories : the preparation of raw material, molding, and plasticity. They are closely connected with one another, which is because it becomes difficult to manufacture quality pottery even with only one incorrect factor. The contents of knowledge involved in the manufacturing process of pottery focused are mainly about raw material, color, shape, distribution aspect, fusion point, durability, physical property, etc, which are all about science. They are rather obtained through the experimental learning process of apprenticeship, not through the official education. It is not easy to categorize the knowledge involved. Most of the knowledge can be understood in the category of ethnoscience. In terms of the UNESCO world heritage of intangible cultural assets, the knowledge is mainly about 'the knowledge on nature and universe'. Unique knowledge and skills are, however, identified in the molding step. They can be referred to 'body techniques', which unify the physical stance of potters, tools they employ, and the conceived pottery. Potters themselves find it difficult to articulate the knowledge. In case stated, it cannot be easily understood without the experience and knowledge on the field. From the preparation of raw material to the complete products, the techniques and traditional knowledge involved in the process of manufacturing pottery are closely connected, employing numerous categories and levels. Such an aspect can be referred to as a 'techniques chain'. Here the techniques mean not only the scientific techniques but also, in addition to the skills, the knowledge of various techniques and levels including habitual, unconscious behaviors of potters.

• Journal of architectural history
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• v.23 no.4
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• pp.47-56
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• 2014

Traditional wall is ground coat, twice plater, last plaster by such a process has made a wide variety of used materials and techniques are accordingly diverse. These traditional techniques handed down the traditional walls of the techniques, rather than coming to the lowered cut off at any moment from now when the technique is used, not knowing whether to be used. Repair and restore cultural property maintenance work, it is not only the outward form hiding inside it is a technique to keep the preservation of cultural assets can be called true. When viewed from the side walls of these conventional techniques to reveal changes in the traditional process by looking at the changes in technology with traditional techniques for cause shall be made in stock. This paper is from the late Joseon Japanese occupation of techniques ranging from traditional wall to reveal the change process to its current significance of cultural property repair method to be helped.