• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.4
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• pp.745-756
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• 2020

An ICS(industrial control system) is a complex system that safely and efficiently monitors and controls industrial processes such as electric power, water treatment, transportation, automation plants and chemical plants. Because successful cyber attacks targeting ICS can lead to casualties or serious economic losses, it becomes a prime target of hacker groups sponsored by national state. Cyber campaigns such as Stuxnet, Industroyer and TRITON are real examples of successful ICS attacks, and were developed based on the deep knowledge of the target ICS. Therefore, for incident investigation of ICSs, inspectors also need knowledge of control processes and accident investigation techniques specialized for ICSs. Because there is no applicable technology, it is especially necessary to develop techniques and tools for embedded controllers located at cyber and physical boundaries. As the first step in this research, we reviewed logging capability of 4 PLC(Programmable Logic Controller)s widely used in an ICS area, and checked whether selected PLCs generate logs that can be used for digital investigation in the proposed cyber attack scenario.

• Journal of The Korean Association For Science Education
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• v.25 no.4
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• pp.526-532
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• 2005

The purpose of this study was to analyze physics problem solving processes to qualitative and quantitative problems in the area of 'Force and Motion' in high school science. The students who have already learned the area of 'Force and Motion' during the first semester of 10th grade have taken physics test to choose students who have basic knowledge of physics. Eight students were selected. After explaining the purpose and the procedure of this study, think-aloud method was instructed to the students, and the students practiced it. After that, the students solved three problems in each quantitative and qualitative type. Then, the questionnaire of belief system on physics and physics problem solving and the prerequisite knowledge test were administered. By recording the students' solving processes, protocol was made and analyzed. After solving problems, the students expressed their confidence, intimacy, and preference. Quantitative problems needed much time at planning step than qualitative problems did. Moreover, solving time was longer and repeating frequency was more than those of qualitative problems. It seemed because even though the students qualitatively knew the answer, they should determine the given quantitative conditions, consider formulae, and recall the specific numbers. Since the students usually got access to many quantitative items in their physics study, they were accustomed to solve problems by using formulae. In addition, they put confidence in formulae, so they tended to solve problems quantitatively. As the result, they preferred quantitative problems to qualitative problems.

• 대한공업교육학회지
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• v.33 no.2
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• pp.120-136
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• 2008

Using the tangible programming tools, which combines physical objects (e.g. robot) and educational programming language, may help to encourage learners' creative thinking as well as to enhance problem solving ability. That is, learners can have opportunities to simulate problem solving processes through the physical objects, such as robots. Therefore, they can minimize an fixation about problem solving process. These experience is effective to induce creative thinking that is useful to find new solutions and change environment actively. Therefore, we developed a robot based programming teaching and learning curriculum and implemented it in college level introductory programming courses. The result shows that the robot based programming learning has a positive effect in all three factors of learners' creative problem solving potential, especially in a cognitive factor. The cognitive factor includes general problem solving abilities as well as factors that explain creativity, such as divergent thinking, problem recognition, problem representation. These result means that the developed robot based programming teaching and learning curriculum give positive effect to creative problem solving abilities.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.57-65
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• 2006

본 연구는 유량에 의한 수면폭의 변화로 인한 하천경관의 시각적 선호도에 미치는 선호요인 파악하였다. 등간척도의 점수부가체계를 적용하여 이용자에 의한 금강경관의 시각적 선호를 평가한 후 시각적 선호와 이에 영향을 미치는 선호요인들과의 관계를 다중회귀분석방법으로 검정하였다. 수면폭 변화에 따른 금강경관의 시각적 선호요인 변수는 심미성 인자, 물리적 특성 인자, 복잡성 인자로서 3개 변수 모두 유의성이 있는 것으로 판명되었다. 모든 선호요인의 값이 증가함에 따라 시각적 선호의 값도 증가를 가져오고 그 반대의 경우도 마찬가지였다.다중회귀모형에서 다른 조건이 불변일 경우, 심미성 인자의 값이 증가할 때 전체적인 시각적 선호에 가장 크게 영향을 미치고, 다음으로 물리적 특성 인자가 두 번째로 영향을 미치는 것으로 판명되었다. 선호요인이 시각적 선호에 기여하는 상대적 중요도는 심미성 인자, 물리적 특성 인자, 복잡성 인자 순으로 나타났다. 심미성 인자는 복잡성 인자에 비해 3.2배 만큼 중요도가 크며 물리적 특성 인자는 복잡성 인자에 비해 3배의 중요도를 가지고 있는 것으로 나타났다. 따라서 심미성인자는 가장 중요한 선호요인으로 판명되었다. 수면폭 변화에 따른 금강경관의 시각적 평가에 의한 선호 요인 분석 결과는 하천의 수면폭 및 수량에 큰 영향을 미칠 것이다. 수위 변화로 인한 하천 경관의 선호 요인을 파악함으로서 금강 유지유량의 결정에 지침을 마련하고, 시각적 선호도에 따른 최적의 수면폭/하폭비 산정하였으며 본 연구 결과는 수량에 의한 수면폭/하폭 비의 변화로 인한 하천경관의 수량결정에 중요한 정보를 제공하고 이용자의 만족을 극대화할 수 있는 경관조성에 기여할 것으로 판단된다. 통하여 유기농업의 실현을 도모하여 소비자의 욕구에 맞는 작물 생산 및 농촌관광단지 조성을 통해 부가가치증대 및 소득증대를 꾀함으로 농촌문제 해결에 도움이 될 것으로 기대된다. 본 연구를 통해 GIS 와 RS의 기술이 농촌분야에 더 효율적으로 적용될 것으로 기대되며, 농업기술센터를 통한 정보제공을 함으로써 대농민 서비스 및 농업기관의 위상이 제고 될 것으로 기대된다.여 전자파의 공간적인 가시화를 수행할 수 있었다. 본 전자파 시뮬레이션 기법이 실무에 이용될 경우, 일반인이 전자파의 분포에 대한 전문지식을 습득할 필요 없이, 검색하고자 하는 지역과 송전선, 전철 등 각종 전자파의 발생 공간 객체를 선택하여 실생활과 관련된 전자파 정보에 예측할 수 있어, 대민 환경정보 서비스 질의 개선측면에서 획기적인 계기를 마련할 것으로 사료된다.acid$(C_{18:3})$가 대부분을 차지하였다. 야생 돌복숭아 과육 중의 지방산 조성은 포화지방산이 16.74%, 단불포화지방산 17.51% 및 다불포화지방산이 65.73%의 함유 비율을 보였는데, 이 중 다불포화지방산인 n-6계 linoleic acid$(C_{18:2})$와 n-3계 linolenic acid$(C_{18:3})$가 지질 구성 총 지방산의 대부분을 차지하는 함유 비율을 나타내었다.했다. 하강하는 약 4일간의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전

• Journal of The Korean Association For Science Education
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• v.24 no.5
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• pp.1008-1017
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• 2004

In physics education, language is an fundamental learning tool as in other subjects. In writing activity, students can get fair opportunities to express their own ideas during the class. Even though there are various styles of writing, students are usually supposed to make a report in their science classes. But there have been few studies in science education on the tasks and features of student's science writing. In this research, different styles of writing tasks were designed for science classes, and students' writing was analysed in terms of conceptual and emotional aspects. Also the usefulness of each task type was discussed relating to school physics education. Four types of writing, i.e. , , , and writing were developed, and 'The reflection of light' was selected as the theme and given to students. Four types of writing were analysed in this paper. In each type of writing, students showed different features in their conception. They also showed emotional expressions in imaginative writing types, that is, and types. Based on these results, it is recommended that in physics teaching various types of writing need to be designed, developed and applied according to the aim of a particular lesson.

• Geophysics and Geophysical Exploration
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• v.13 no.4
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• pp.378-387
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• 2010

We present the results of laboratory measurement of porosity and electrical resistivity for the samples collected near marine hydrothermal deposit to provide fundamental perspective of physical properties for future electromagnetic survey. The rock cores are sampled from the host rock, pumice, hydrothermal altered zone, and chimney. These samples are featured as easily brittle, rough surface with large pores, having components easily solvable in the water. We suggest systematic approach for measuring weights, volumes of core samples to calculate density and porosity. Measurements reveal that the resistivities of black host rock, gray host rock, pumice and chimney are 102, 39, 11, 0.1 ohm-m, respectively, when the core samples are saturated with saline water of $32,000\;{\mu}S$/cm (0.5 ohm-m) at temperature of $2.5^{\circ}C$ and these correspond to the factors of 5 for sea water, 110 for pumice and 390~1020 for host rocks with respect to the resistivity of chimney. We also confirm that resistivity of rock samples saturated with water decrease with temperature linearly over the temperature range of $20{\sim}80^{\circ}C$.

• Geophysics and Geophysical Exploration
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• v.1 no.1
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• pp.8-18
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• 1998

In exploration seismology, the Kirchhoff hyperbola has been successfully used to migrate reflection seismo-grams. The mathematical basis of Kirchhoff hyperbola has not been clearly defined and understood for the application of prestack or poststack migration. The travel time from the scatterer in the subsurface to the receivers (exploding reflector model) on the surface can be a kinematic approximation of Green's function when the source is excited at position of the scatterer. If we add the travel time from the source to the scatterer in the subsurface to the travel time of exploding reflector model, we can view this travel time as a kinematic approximation of the partial derivative wavefield with respect to the velocity or the density in the subsurface. The summation of reflection seismogram along the Kirchhoff hyperbola can be evaluated as an inner product between the partial derivative wavefield and the field reflection seismogram. In addition to this kinematic interpretation of Kirchhoff hyperbola, when we extend this concept to shallow refraction seismic data, the stacking of refraction data along the straight line can be interpreted as a measurement of an inner product between the first arrival waveform of the partial derivative wavefield and the field refraction data. We evaluated the Kirchhoff hyperbola and the straight line for stacking the refraction data in terms of the first arrival waveform of the partial derivative wavefield with respect to the velocity or the density in the subsurface. This evaluation provides a firm and solid basis for the conventional Kirchhoff migration and the straight line stacking of the refraction data.

• Archives of design research
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• v.13 no.4
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• pp.195-201
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• 2000

To find out media's function on the various effects in communication, this paper reviews studies that utilize multimedia as a device for conveying information. We discuss multimedia as an integrated symbol system with advantages and also problems in representing information. The cognitive dissimilarity of media could be explained by various attributes of medium that are about physical characteristics and even cognitive actions. With advantages from integrated media and interactivity, multimedia has negative results such as cognitive overload and in that reason systematic approach is needed. This paper shows the factors on media selection and relationship to interface components. To select appropriate media to the needs and situation, it should be considered the user's ${\circled1}$background ${\circled2}$knowledge / frequency of use / expertise, contents ${\circled1}$task nature ${\circled2}$type of knowledge and media ${\circled1}$representation format ${\circled2}$interaction techniques. Varying the media factors and varying the expression factors offers concrete design features.

• Journal of Conservation Science
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• v.22
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• pp.109-120
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• 2008

Understanding the whole knowledge of ceramics is essential for a person in charge of conservation of ceramics since their methods of manufacturing or materialistic features have very close relationship with their damaging process. Also, various executions of repair and restoration dealing with any damage in use have to be looked into. The information attained through those studies finds damaging causes of ceramics, which becomes a critical element when choosing a proper conservation treatment method and utilizes as indispensable data for permanent preservation. As part of scrutinizing materials of repair and restoration, this study examines the purpose, date, and the constituents of the materials used in metal bound rims adhered to the brim of ceramics. Among the subjected ceramics, the metal bound rims possible to scientific analysis were gone through element analyses with Portable ${\bullet}\"{I}$-XRF Spectrometer and SEM-EDS while the ingredients of the ceramics difficult to analyze were inferred by eye inspection of exhibition catalogues. The results of this study confirm that metal bound rims consisted of diverse materials were adhered to the brim of ceramics.

• The Journal of the Korea Contents Association
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• v.17 no.11
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• pp.331-341
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• 2017

As increasing the importance of the R&D strategy planning based on S&T evidence, the S&T DB was conducted to develop appropriate basic research support strategies by collecting 49 multiple-nations' statistics and information, extracting 6446 raw data, categorizing 877 indicators including 208 core indicators. An statistical and knowledge map analysis using the highly cited publication-related indicators was conducted to examine the expansion of DB utilization by demonstrating effectiveness of Korea's basic research. As a result, basic research investment have a strong influence on creating outstanding R&D outcomes and on producing a foundation of various S&T based-growth engines.