• Journal of the Korean Geosynthetics Society
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• v.21 no.2
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• pp.57-65
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• 2022

This study simulated the shock wave propagation through the tamping material between explosives and hole wall at blasting works and verified the effect of tamping materials. The Arbitrary Lagrangian-Eulerian(ALE) method was selected to model the mixture of solid (Lagrangian) and fluid (Eulerian). The time series analysis was carried out during blasting process time. Explosives and tamping materials (air or water) were modeled with finite element mesh and the hole wall was assumed as a rigid body that can determine the propagation velocity and shock force hitting the hole wall from starting point (explosives). The numerical simulation results show that the propagation velocity and shock force in case of water were larger than those in case of air. In addition, the real site at blasting work was modeled and simulated. The rock was treated as elasto-plastic material. The results demonstrate that the instantaneous shock force was larger and the demolished block size was smaller in water than in air. On the contrary, the impact in the back side of explosives hole was smaller in water, because considerable amount of shock energy was used to demolish the rock, but the propagation of compression through solid becomes smaller due to the damping effect by rock demolition. Therefore, It can be proven that the water as the tamping media was more profitable than air.

• Journal of Elementary Mathematics Education in Korea
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• v.10 no.1
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• pp.67-87
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• 2006

This study is to recognize a problem in the practice of performance assessment in elementary school, and to find out some suggestive points for improvement of teaching·learning method in elementary mathematics through assessment by reducing time restriction according to assessment through the practice of self-assessment, peer-assessment and observation, and then by reflecting the results of assessment on teaching learning plan. For that, the questions of study set up are as follows ; 1. How should self-assessment and peer-assessment be applied to in elementary mathematics assessment? 2. How should the time for 'let's play an interesting game' be managed for assessment of elementary mathematics? 3. How should the results of assessment be reflected on the Process of teaching and learning of mathematics? To solve these problems, a researcher of this thesis performed self-assessment, peer-assessment on 40 students of second grade under her charge as a class teacher, and applied observation in the time management process for 'let's play an interesting game' for a semester. self-assessment was made by mathematics journal, self-assessment chart, peer-assessment was by the analysis of conversation record among students in the situations of assessment, and observation was by observation of activity when playing with the results data of play analyzed. the concrete methods of application as follows ; First, mathematics journal was applied $1{\sim}2$ times by each unit with reconstruction into the level of second grade on the basis of the preceding-study models. Second, peer-assessment was applied to the unit-assessment time and the play-activities time by the method of recording·analyzing the contents of conversation among students in the process of assessment. Third, mathematical attitude & dispositions of students making use of the self- assessment table were examined referring to the teaching learning plan. Fourth, the time management for 'let's play an interesting game' was made through the prior recognition of play method and the joyful play-activities by use of the play-plate. Assessment depended on analysis of play-activities results of students making use of an observation form. Fifth, the results of self-assessment, peer-assessment, and observation were analyzed, and then they were made use of as self-observation data, of teacher her/his self, or teaching·learning improvement data. Students' self-assessment datum (mathematics diary, self-assessment sheets, conversation contents in the process of assessment) and observation materials (check lists, Play-activity result materials, conversation contents in the process of play) obtained in the process of application was analyzed as follows ; 1. From the practice of self-assessment in form of mathematics journal, I could obtain not only datum showing how much students was understanding the learning aims by unit time and to any degree they reached but also information about their response to learning datum and favorable type of learning. 2. Assessment by self-assessment chart was useful in planning the mathematics teaching learning process because it helps ascertain mathematical attitude & dispositions of students. 3. Through the application of peer-assessment, students had the opportunity of communicating with other students looking back on his/her explaining process, and teachers could obtain basic materials for assessment of students. 4, In case of time management for 'let's play an interesting game', there was natural extension of play made through time-security by prior looking into the method of play-activity, and then, for a remained time, by making children play a new game. 5, I could easily record the activities of students by use of the observation. form, and make use of it as basic data for descriptive assessment. 6, Each kinds of data obtained from the results of assessment was helpful for securing self-observation materials in the process of teaching learning and for their betterment in mathematics subject. However, because they were in the second grade of elementary school and there was an individual difference, some students could not make use of mathematics diary or self-assessment form properly. In case of these students, assessment data would be obtained through interview or observation. And for effective operation of play, its purpose & method and matters that demand special attention when play-acting should be clearly guided. Also, when applying an effective play in addition to play activities in textbook, to lessons, interesting mathematics lessons could be guided.

• The Journal of Engineering Geology
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• v.30 no.4
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• pp.457-468
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• 2020

Problems arising during pile design works for plant construction, civil and architecture work are mostly come from uncertainty of geotechnical characteristics. In particular, obtaining the N-value measured through the Standard Penetration Test (SPT) is the most important data. However, it is difficult to obtain N-value by drilling investigation throughout the all target area. There are many constraints such as licensing, time, cost, equipment access and residential complaints etc. it is impossible to obtain geotechnical characteristics through drilling investigation within a short bidding period in overseas. The geotechnical characteristics at non-drilling investigation points are usually determined by the engineer's empirical judgment, which can leads to errors in pile design and quantity calculation causing construction delay and cost increase. It would be possible to overcome this problem if N-value could be predicted at the non-drilling investigation points using limited minimum drilling investigation data. This study was conducted to predicted the N-value using an Artificial Neural Network (ANN) which one of the Artificial intelligence (AI) method. An Artificial Neural Network treats a limited amount of geotechnical characteristics as a biological logic process, providing more reliable results for input variables. The purpose of this study is to predict N-value at the non-drilling investigation points through patterns which is studied by multi-layer perceptron and error back-propagation algorithms using the minimum geotechnical data. It has been reviewed the reliability of the values that predicted by AI method compared to the measured values, and we were able to confirm the high reliability as a result. To solving geotechnical uncertainty, we will perform sensitivity analysis of input variables to increase learning effect in next steps and it may need some technical update of program. We hope that our study will be helpful to design works in the future.

• Journal of Society of Preventive Korean Medicine
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• v.19 no.2
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• pp.23-35
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• 2015

Objective : As part of the Korean Medicine Official Development Assistance(ODA) and Public Health Project, we implemented a obesity management program(OMP) using Korean medicine in Uzbekistan and its follow-up study was conducted to evaluate the effectiveness of the program. Method : We recruited the participants of whose Body Mass Index(BMI) were over $25kg/m^2$ and who agreed to participate in the program at the South Korea-Uzbekistan Friendship Korean Medical Hospital in Uzbekistan. The program consisted of auricular acupuncture, functional food, and education program on diet and exercise. It was provided once a week during 7-week period. Anthropometric measurements and blood test measuring total cholesterol, triglyceride, and glucose were performed at the baseline, the end of the program, and 10-month follow-up. At the end of the program and the follow-up, survey on satisfaction and self-evaluation of the effectiveness of the program was additionally conducted. Results : 43 out of 78 participants completed the program and were included in the analysis. The analysis of the main outcomes showed that there were significant decreases in anthropometric measurements such as body weight, waist circumference, body mass index (BMI) and body fat content as well as blood test including triglycerides, total cholesterol and blood glucose levels. In the follow-up study, 24 subjects participated and 19 subjects (79.1%) reported that they succeeded in weight control. Furthermore, many participants reported that they maintained healthy lifestyles like healthy diet and regular exercise. The satisfaction with the program was also relatively high, and the education program was selected as the most motivating intervention for weight control. The outcomes such as body weight, BMI, body fat content, and blood glucose level were maintained to be at the decreased level; however, waist circumference, total cholesterol and triglycerides levels either returned back to the baseline level or were elevated to the level higher than the baseline. Conclusion : This study suggests that the OMP using Korean medicine may contribute to weight control of obese population in Uzbekistan. It is meaningful in that the study shows the possibility of implementing health promotion programs using Korean medicine in other countries with different cultures. In the future, more efforts to evaluate the effectiveness of the programs using rigorous methodologies and utilize the effective programs in ODA project will be needed.

• Archives of design research
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• v.19 no.5 s.67
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• pp.335-350
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• 2006

Due to the development in industrial technology, changes in consumer behavior and aggravating competition within the industry, it is growing only harder every day to build up a strong brand power. Besides, a brand is supposed to age as time goes by, following a brand life cycle, as it is not a solid, immutable asset but something of a living creature. Therefore, self-renovation and revitalization efforts are needed, in order to incessantly confirm the self existence through the relationship with the consumer. In sum, revitalization operation is needed to renew a brand that has grown trite in the passage of time or due to the change in market condition, so as to bring it back anew to the consumers. This study did not stop at measuring the effect of a design renewal as a short-term assignment, but focused on the long-term brand management following the brand life cycle and aimed to define the effective timing and method of revitalization by comprehending the analysis results of consumer consciousness by analyzing the successful cases of brand revitalization and selecting the research analysis targets. As a result, this study proved that a properly-timed brand revitalization efforts in order to cope in advance with predictable changes in environment, can significantly prevent any drop of brand equity from occurring and then extend the brand life cycle. Also, this study could find that a brand revitalization is not a mere concept of a strategy for a short-term sales increase, but should be a long-term strategy to manage a brand, which must be practiced continuously in the time when the brand life cycle curve starts to fall. This research could also confirm that a superficial design renewal, which changes only the packaging of a brand, peformed in short-term haste, is not of help at all.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.3
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• pp.319-332
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• 2015

The pressure wave formed by the piston effects of the train proceeds within the tunnel when a train enters the tunnel with a high speed. Depending on the condition of tunnel exit, the compression waves reflect at a open end, change to the expansion waves, transfer to tunnel entrance back. Due to interference in the pressure waves and running train, passengers experience severe pressure fluctuations. And these pressure waves result in energy loss, noise, vibration, as well as in the passengers' ears. In this study, we performed comparison between numerical analysis and field experiments about the characteristics of the pressure waves transport in tunnel that appears when the train enter a tunnel and the variation of pressure penetrating into the train staterooms according to blockage ratio of train. In addition, a comparative study was carried out with the ThermoTun program to examine the applicability of the compressible 1-D model(based on the Method of Characteristics). Furthermore examination for the adequacy of the governing equations analysis based on compressible 1-D numerical model by Baron was examined.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.2
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• pp.433-452
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• 2018

The shield tunneling method can minimize surface settlements by preventing the deformation of tunnel face and tunnel intrados due to tunnel excavation. For this purpose, it is very important to control the operating conditions of shield TBM. The face pressure and backfill pressure for tail void grouting should be the most important and immediate measure not only to restrain surface settlement, but also to influence the effective stress and pore water pressure around the circumstance of tunnel during excavation. The reaction of the ground to the application of face pressure and backfill pressure relies on the stiffness and permeability of ground. Especially, the reaction of saturated clayey ground formations, which shows the time-dependent deformation, is different from the permeable ground. Hence, in this paper it was investigated how the TBM operating conditions, ground stiffness, and permeability impact on the surface settlement of saturated clayey ground. For this purpose, a series of parametric studies were carried out by means of the stress-pore water pressure coupled FE analysis. The results show that the settlement of soft clayey ground is divided into the immediate settlement and consolidation settlement. Especially, the consolidation settlement depends on the ground stiffness and permeability. In addition, the existence of critical face pressure and backfill pressure was identified. The face pressure and backfill pressure above the critical value may cause an unexpected increase in the ground settlement.

• The Journal of Art Theory & Practice
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• no.2
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• pp.49-74
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• 2004

It has been frequently pointed out that the established art history with the stylistic and iconographic interpretations and monographic analysis is fallen behind the currency of modern art. Among those who claimed the crisis in the discipline of art history, there is a suggestion that the art historical study should be fostered by other factors in the fields of the humanities. The so called New Art History or 'visual Culture Studies' insists that art history has to be restructured to integrate the broader study of culture and society, and by now, such an opinion is not a novelty at all. One of the most significant yet overlooked elements that induced the new currency of art history is properties of contemporary art that conflict the traditional claim of art historians. Although the idea that art is not purely aesthetic but that it has many other functions has been brought up by the art historians, it was the artists that provoked such a perception. When Arthur C. Danto and Hans Belting proclaimed the End of Art and Art History in the 1980s, the concept of art has been changed radically through the avant-garde tendency of Modernism and a new pluralism of Postmodernism. One dominant concern that strikes art historians is to find a new approach to art, since the traditional method and goal of analysis for past art and past art history seem unavailable. The perplexity arising from the situation is intensified in the field of teaching art, especially for those who teach art history in art school. Basically art history is a pursuit of learning of art in history, and its purpose is to reconcile the present with the past and the future as well. Since Modernism, as it is confusing sometimes because it implies the present state, somehow art became considered 'tradition-less'. It does not mean that a work of art stands aloof from the past attainments, hut modern art imposed itself on a task seeking after the new for its own sake, turning its back on the tradition. And now in the era of Postmodernism, an historians face the requirement to revaluate the whole history of art including modernism. The necessity of art history in art education is indisputable, but methods and contents in the academic courses should he reexamined now. Because artists' concept of history and past art has been altered, and art history as a humanistic discipline can only maintain its identity through incorporation with art itself. Academics teaching art history, or, strictly speaking, past works of art and history, to the student in art school, confront with the need to rethink the object of art history and its meaning to the artists.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.6
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• pp.547-554
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• 2010

In this study, new manganese oxide (i.e., black-birnessite) particles with nanostructures were prepared and its physico-chemical properties and oxidative-transformation efficiency on 1,4-naphthoquinine(1,4-NPQ) in the presence of reactive mediator was investigated. The results were also compared with that of the manganese oxide (i.e., brown-birnessite) particles synthesized by classical McKenzie method. Analysis of XRD and SEM data show that the particles are a single phase corresponding to a birnessite-based manganese oxide with cotton ball-like shapes containing nanofibers. In batch experiments, removals of 1,4-NPQ by the black-birnessite follows pseudo-first-order kinetics and the rate constant values obtained are greater about 2.3 times than that of the brown-birnessite in spite of its lower surface area (41.0 vs 19.80 $m^2/g$). The results can be explained by the higher crystallinity and nano structured features of the back-birnessite particles, which give higher reactivity for the removals of the quinone compound. HPLC analysis of the reaction products confirmed that the balck-birnessites removed 1,4-NPQ through cross-coupling reaction in the presence of catechol as a reactive mediator.

• Korean Journal of Applied Biomechanics
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• v.18 no.4
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• pp.67-76
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• 2008

The purpose of this study was to analyze differences in kinematic variables for mogul short turn motion between superior and inferior group, so that it can explore more effective mogul short turn motions. To meet the goals, this study selected total 10 ski players who would participate in mogul short turn event of the National Technical Ski Championship 2007, so that it could analyze kinematic variables by way of 3D motion analysis using DLT method. As a result, this study came to the following conclusions; For total and phase-specific duration, it was found that superior group took shorter time than inferior group. Superior group's Center of Mass was stands for more high value in up-down movement skill than inferior group. However right-left movement scale was less than them. In this reason, superior group was made a straight descent at the same time made a fast front-rear velocity. In the part of up-down movement velocity show that move slowly in the drop-in phase while increased in the bump-up phase. It is show that superior group was less tinny than inferior group include joint angle and knee joint angle. However leaning angle of trunk and the body inclination angle were more high figured than inferior group. Leaning angle of lower limbs also showed high figure at the center mogul. Lastly, In the part of body torsion angle show that superior group was high figure direction of right turn in the drop-in phase while in bump-up phase, made a high figure direction of left turn.