• Journal of Korean Elementary Science Education
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• v.30 no.3
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• pp.305-314
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• 2011

In this study, the analogies on saturated solution generated by elementary school teachers were analyzed in their numbers, materials, and types aspects. The results were also compared with those of general and science-gifted elementary students. A test on the self-generating analogies on the target concept was administered to 111 elementary school teachers, 60 fifth graders at four science-gifted education institutes and 91 fifth graders at three elementary schools. The results revealed that the teachers made more analogies than the general and science-gifted students. In general, both the teachers and the students tended to make the analogies using the materials in family, riding, digestive, and school situations. However, there were a little difference between the teachers and the students in the cases of the analogies using other situations including body/physical activity. Similarly to the cases of the students, the teachers made more functional analogies than structural or structural/functional ones and did more concrete ones than abstract ones. However, they made more verbal, artificial, and enriched analogies than the students. They also made more highly systematic analogies than the general students, and did less ones than the science-gifted students. Educational implications of these findings are discussed.

• Journal of Electrical Engineering and Technology
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• v.4 no.3
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• pp.301-309
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• 2009

A simple and efficient Lambda logic (${\lambda}-logic$) based algorithm is proposed for the solution of the generator constrained economic dispatch problem when the generating units having prohibited zones. The proposed method solves the economic dispatch (ED) problem that takes into account ramprate limits, transmission losses and prohibited operating zones in the power system operation. The proposed method uses a simple heuristic rule based on average power of prohibited operating zones which produces the feasibility of solution for the restricted operating units. The effectiveness of the algorithm is tested on five different test systems and the performance compared with other relevant methods reported in the literature. In all the cases, the proposed algorithm performs better than the previous existing algorithms with a less computational burden.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.11
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• pp.765-778
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• 2013

This paper proposes a test case generation method for Stateflow model using the extended RRT method. The RRT method which has been popularly used for planning paths for complex systems also shows a good performance for test case generation. However, it does not consider the test coverage which is important for test case generation. The proposed extension method hires the concept of test goal achievement to increase test coverage and drives RRT extension in the direction that increases the goal achievement. Considering the concept, a RRT distance metric, random node generation method and modified RRT extension algorithm are proposed. The effectiveness of proposed algorithm is compared with that of the typical RRT algorithm through the experiment using the practical automotive ECUs.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.3
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• pp.391-400
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• 2016

In satellite operations, stable maneuvering of a satellite's onboard antenna to prevent undesirable vibrations to the satellite body is required for high-quality high-resolution images. For this reason, the onboard antenna's angular rate is typically minimized while still satisfying the system requirement that limits the speed of the onboard antenna. In this study, a simple yet effective method, called the ground station searching method, is proposed to reduce the angular rate of a satellite's onboard antenna. The performance of the proposed method is tested using real flight data from the KOMPSAT-3 satellite. Approximately 83% of arbitrarily selected real flight scenarios from 66 test cases show reductions in the onboard antenna's azimuth angular rates. Additionally, reliable solutions were consistently obtained within a reasonably acceptable computation time while generating an onboard antenna tracking profile. The obtained results indicate that the proposed method can be used in real satellite operations and can reduce the operational loads on a ground operator. Although the current work only considers the KOMPSAT-3 satellite as a test case, the proposed method can be easily modified and applied to other satellites that have similar operational characteristics.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.4
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• pp.573-582
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• 2020

Fuzzing is a method of testing software by randomly generating test cases. Since its introduction, a variety of fuzzing techniques have been studied. Among them, mutation-based fuzzing is an efficient method that finds real-world bugs even though it uses a simple approach such as probabilistic bit-flipping and character substitution. However, the interpreter fuzzing has difficulty in applying general mutation techniques because the interpreter requires grammar and semantic correctness input values. In this paper, we present a novel mutation-based fuzzing on JavaScript interpreters with a dynamic data flow analysis. To this end, we implement JMFuzzer that can generate various types of mutated test cases that operate normally without runtime errors in JavaScript interpreter considering syntax and semantics. As a result, we found numerous unknown vulnerabilities in the latest JavaScript interpreters. We reported all of them to the vendors.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.4
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• pp.811-820
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• 2017

Software automatic technology research recently focuses not only on generating a single path test-case, but also on finding an optimized path to reach the vulnerability through various test-cases. Although Dynamic Symbolic Execution (DSE) technology is popular among these automatic technologies, most DSE technology researches apply only to Linux binaries or specific modules themselves. However, most software are vulnerable based on input files. Therefore, this paper proposes an input file based dynamic symbolic execution method for software vulnerability verification. As a result of applying it to three kinds of actual binary software, it was possible to create a test-case effectively reaching the corresponding point through the proposed method. This demonstrates that DSE technology can be used to automate the analysis of actual software.

• Journal of Korea Association of Health Promotion
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• v.4 no.1
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• pp.125-131
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• 2006

Background: Inadequate samples make laboratory tests delay cause errors, which will deteriorate the quality of the tests. Therefore, adequate samples are essential for reliable test result. To reduce the inadequate samples, they should to analyze problems and seek a way of improvement through CQI (Continuous Quality Improvement) activity. This will minimize errors during the test and produce a fast and accurate result. Eventrally, the qualily of entire test may be improved, and as a result, a good quality of medical care service may be provided. Methods: At first, inappropriate testing items were collected. Then, generating fctors and problems were investigated and analyzed in each case, In addition, the category with higher frequency wes primarily supervised. In consegalnce, a reduction of are dustion of improper testing sample was oxpected through continuous education and CQI activity. Conclusion : At the beginning of CQI activitv, the number of inadequate testing sample was of 8,591 total samples, which gives the frequency of 0.72%. As CQI activity was carried out the number of improper testing sample reduced to 58 out of 11,415 cases, which yields the frequency of 0,51%. One may notice the difference 0.2%. Among the inadequate sample(blood), there was a high frequency of hemolysis; thus, more of CQI activity is required for this specific matter. Because the occurrence of inadequate testing affects the clinical outcomes, it is extremely important that one manages each step of the procedure in collecting samples and mamtaines the quality of entire tests.

• Journal of Electrical Engineering and Technology
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• v.3 no.3
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• pp.293-299
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• 2008

One of the problems with the fault diagnosis of transformers based on dissolved gas is the inability to match the result of the different standards of fault diagnosis with real world standards. In this paper, the results of the different standards are analyzed using fuzzy logic and then compared with the empirical test. The proposed method is based on the standards and guidelines of the International Electrotechnical Commission (IEC), the Central Electric Generating Board (CEGB), and the American Society for Testing and Material (ASTM) and its main task is to assist the conventional gas ratio method. The comparison between the suggested method and existing methods indicates the capability of the suggested method in the on-line fault diagnosis of transformers. In addition, in some cases the existing standards are not able to diagnose the fault. For theses instances, the presented method has the potential of diagnosing the fault. In this paper, the information of three real transformers is used to show the capability of the suggested method in diagnosing the fault. The results validate the capability of the presented method in fault diagnosis of the transformer.

• Journal of Mechanical Science and Technology
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• v.15 no.2
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• pp.160-171
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• 2001

Depending upon the method of the surface generation and the quality of the designed boundary curves, the resulting surfaces may have global or local irregularities in many cases. Thus, it would be necessary for the designer to evaluate the surface quality and to modify the surface. This is very important because the defect of the surface causes the rework of the dies, increasing cost and delivery time significantly. To simulate the reflection line test in the actual production line, a faster algorithm for generating reflection lines is presented. In this paper, among various surface interrogation methods using reflection lines, Blinn-Newell type of reflection mapping is applied to generate the reflection lines on the trimmed NURBS surfaces. The derivation of reflection lines is formulated as a surface-plane intersection problem (Jung 1994) and is solved by surface-contouring techniques. Also, for eliminating the discontinuity of reflection lines due to the configuration of reflection map, a modified reflection map is proposed. An efficient traced contouring technique is utilized for the computational efficiency and proves to be well suited for the real-time quality-assessment task.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.5
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• pp.898-904
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• 2009

The objective of the present study lies in constructing web-based GIS system providing broad range of information applicable for power/telecommunications distribution facilities through cable. Nowadays, Korea is renowned forits faste sttele communications network across the nation enjoyable for being a test-runbed by worldwide contents providers. It is not too much to say that the trend is caused by the fact that Korea utilizes the cobweb-like power transmission cables applicable for the nationwide telecommunications networking. In particular, the trend has been all the more encouraged by the governmental drive to expedite the telecommunication network by way of the established power transmission facilities deemed as publicutility. Nevertheless, few can deny that the overexcessive competition among telecommunication service providers increasingly gives rise to unauthorized, arbitrary facilitation of distribution devices, which becomes much burden in operating the normal power/telecommunications distribution facilities by a power-generating company. In this regard, the study, to cope with such problems, attempts to develop a web GIS-based information management system compatible with NDIS(New Distribution Information System), a distribution facility management system now under operation by KEPCO, making advantage of GE Energy's SIAS(Smallworld Internet Application) technology. The model provided by this study is expected to get closer into effective operation of distribution facilities along with better sharing of information among conventional telecommunications operators, while getting rid of infringed facilitation cases