• Fire Science and Engineering
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• v.31 no.6
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• pp.33-39
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• 2017

Composite panel refers to the particular plywood produced in a way of stacking the different kinds of material in sandwich form and adhering them using adhesives and is widely used as building material for its constructability and cost efficiency. But as the surface is finished with steel plate, fire extinguishing agent cannot reach to the core material because of such steel plate on surface which causes the difficulties in suppressing the fire as well as in fire-fighting activities due to collapse. This study, to deal with such problem, is intended to set the fire pipe in core material to prevent the fire from spreading and in a bid to achieve this using minimized fire water, water supply test device was fabricated to estimate the required water flow of fire extinguisher and consequently, optimal water flow (0.5 L/min) was determined through a full-scale fire test.

• Magazine of the Korean Society of Agricultural Engineers
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• v.40 no.5
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• pp.91-99
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• 1998

The widespread use of thin shell structures has created a need for a systematic method of analysis which can adequately account for arbitrary geometric form and boundary conditions as well as arbitrary general type of loading. Therefore, the stress and analysis of thin shell has been one of the more challenging areas of structural mechanics. A wide variety of numerical methods have been applied to the governing differential equations for spherical and cylindrical structures with a few results applicable to practice. The analysis of axisymmetric spherical shell is almost an every day occurrence in many industrial applications. A reliable and accurate finite element analysis procedure for such structures was needed. Dynamic loading of structures often causes excursions of stresses well into the inelastic range and the influence of geometry changes on the response is also significant in many cases. Therefore both material and geometric nonlinear effects should be considered. In general, the shell structures designed according to quasi-static analysis may fail under conditions of dynamic loading. For a more realistic prediction on the load carrying capacity of these shell, in addition to the dynamic effect, consideration should also include other factors such as nonlinearities in both material and geometry since these factors, in different manner, may also affect the magnitude of this capacity. The objective of this paper is to demonstrate the dynamic characteristics of spherical shell. For these purposes, the spherical shell subjected to uniformly distributed step load was analyzed for its large displacements elasto-viscoplastic static and dynamic response. Geometrically nonlinear behaviour is taken into account using a Total Lagrangian formulation and the material behaviour is assumed to elasto-viscoplastic model highly corresponding to the real behaviour of the material. The results for the dynamic characteristics of spherical shell in the cases under various conditions of base-radius/central height(a/H) and thickness/shell radius(t/R) were summarized as follows : The dynamic characteristics with a/H. 1) AS the a/H increases, the amplitude of displacement in creased. 2) The values of displacement dynamic magnification factor (DMF) were ranges from 2.9 to 6.3 in the crown of shell and the values of factor in the mid-point of shell were ranged from 1.8 to 2.6. 3) As the a/H increases, the values of DMF in the crown of shell is decreased rapidly but the values of DMF in mid-point shell is increased gradually. 4) The values of DMF of hoop-stresses were range from 3.6 to 6.8 in the crown of shell and the values of factor in the mid-point of shell were ranged from 2.3 to 2.6, and the values of DMF of stress were larger than that of displacement. The dynamic characteristics with t/R. 5) With the thickness of shell decreases, the amplitude of the displacement and the period increased. 6) The values of DMF of the displacement were ranged from 2.8 to 3.6 in the crown of shell and the values of factor in the mid-point of shell were ranged from 2.1 to 2.2.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.3
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• pp.398-405
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• 1995

In termperate zone planting rice at different date subjects the crop to different climatic condition. This study aimed at comparison of the change in source-sink relationship of the Japonica(J) and that of Indica Japonica(I$\times$J) type rice cultivars caused by shift of heading date. Two J-and two I$\times$J-type cultivars were made to head on Aug. 16, Aug. 26 and Sep. 5. Percent grain fertility was not changed in response to shift of heading date. Ripening patterns of 4 rice cultivars were similar to sigmoid curve type but when the heading date was delayed to Sep. 5, the form is changed to log type of curve. In J-type, physiological maturity was delayed about 5 day when headed at Sep. 5, in compare to headed at Aug. 16 and Aug. 26. However ripening was continued about 10 days when the diurnal, nocturnal and minimum temperature was above 17, 12$^{\circ}C$ and about 3~8$^{\circ}C$. In I$\times$J hybrid, real ripening was continued when the diurnal, nocturnal and minimum temperature was over 20, 17$^{\circ}C$, but if the minimum temperature was downed bellow 1$0^{\circ}C$, it was impossible. Simulated photosynthetic amount based on photosynthetic ability, temperature, leaf area and day length was varied according to changes in heading date and it was decreased seriously if the minimum temperature was fall down bellow 4$^{\circ}C$ in field, that's why decrease in photosynthetic ability and aging. The temperature range of optimum ripening was 21~26$^{\circ}C$, if there is nothing hindering factor.

• Journal of Elementary Mathematics Education in Korea
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• v.20 no.2
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• pp.193-213
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• 2016

This study has two goals. The First is to develop and apply a step-by-step program and the degree to which students' mathematical skills. The second is to analyze mathematical attitude change around the first grade students was done. The program for learning complement number is composed of series of 5 steps and 11 classes. Play for learning complement number, taking into account the difficulty of the learning steps 1-5 are organized. First step is composed of the classes which fragmented pieces of shapes to complete the entire geometry with fun activities for the entire part of the concept of learning and it maintenance concepts and can naturally learn by associating step. In second step, tools to take advantage of the real world and collecting the conservative concept. 3rd steps is to repair the mathematical concept of the parish in the learning stage of expansion. 4th step is halrigalri, number cards, making ten games etc. 5th step is to verify the concept of complement number and number operation ability. The concept of complement number through fun activities can improve students' mathematical skills, and mathematical attitude change. Early in the program, students use the finger to throw acid in the process. Simple addition and subtraction calculations may take a long time and error, but more and more we progress through the program using the fingers is eliminated and a more complex form calculations was not difficult to act out.

• Science of Emotion and Sensibility
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• v.8 no.4
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• pp.423-433
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• 2005

The computer hardware development has provided many chances of emergence between art and technology. In many cases today's interactive artworks cannot be completed without audience's participation. The interactive production process with technical supplementation can be celled feedback. Mr. Nam Jun Paik showed 'Participant TV' that interacts with audience's response in real time. It means artwork changes with the constantly changing value from the data set from human visual perception. Dan Graham showed another feedback related work, which delays 5second playback in mirror that implies consequence of time. Today's media art has to sublimate coincidence, time ant audience into philosophical artwork through consonance that comes with video and sound as we can see from Bill Viola. Stelarc produced artworks. That use input data that is weak signals from brain, muscles. Through a terminal display with player, body expanded meaning of media. Jeffrey Shaw's 'Legible City' provided a fabrication of the reality with the interaction of bicycle's pedal speed and steering direction that is controlled by 4river. RE:MARK used microphone as input device as Edmond Couchot's 'Je same a la vent' and Nam Jun Paik's 'Participant TV' did. There is no communication without feedback between human being. The reality makes audience involved into artworks. That is the reason why feedback has to be natural. Through the feedback process, the originality of the idea is altered by audience. The feedback is not just part of flesh of artwork rather skeleton of it. Technological showoff cannot be art itself The perfection of technological application plan helps feedback that interacts with audience naturally in order that audience hoes not feel the feedback as artificial plan. Interactive media art has to be evolved into new media form with new integration feedback technology.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.4
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• pp.55-61
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• 2010

This paper is concerned with an experimental research to random vibration control caused by external loads specially in bridges which tend to be structurally flexible. Experimenting on a reduced structure modelled on Seohae Grand Bridge, we inflicted a reduced form of El-centro wave on the model structure to a proper proportion. On the center of its middle span, we placed a shear type MR damper which was to control its vibration and also acquire its structural responses such as displacement and acceleration at the same site. The experiments concerning controlling vibration were performed according to a variety of theories including un-control, passive on/off control, and Lyapunov stability theory. Its control performance was evaluated in terms of the peak absolute displacements, the peak absolute accelerations and the total power required to control the bridge which differ from each different experiment method. Among all the methods applied in this paper, case of Lyapunov control method turned out to be the most effective to reduces of displacement and acceleration. Also, this method could to decrease consuming of external power for vibration control. Finally, it was noteworthy that Lyapunov control method was specially effective in the vibration control employing a semi-active damper such MR damper.

• Journal of the Institute of Convergence Signal Processing
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• v.17 no.1
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• pp.10-17
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• 2016

GPS location information storage included in the HD black box is using a unique manner for each manufacturer does not have a specific standard. In this paper, in order to overcome the limitations of the storage space and thereby the image quality according to store GPS position information deteriorate to solve the problems that cause, we propose the location information concealment method included in the HDTV video content using a essential hidden region. HDTV video content is a Border Extender of 8 lines in the frame to the bottom of the compression will be required. This was inserted into the image of a gray scale used in block form in order to space the current position information is concealed to prevent image degradation. The proposed method was confirmed using real HD black box, there are more difficult to interpret the format of the ASCII code re-edit the location information when the compression effect disappears with the existing security zones added. Therefore, the proposed method is suitable for location-based services, such as Facebook or Youtube videos.

• The Journal of Korean Medicine
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• v.18 no.1
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• pp.126-142
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• 1997

For last four or five years, the number of Korean students have gone on increasing awfully. After the year 1997 when they will flow in, our field and government will be undergone a big shock and social problems. Therefore, thorough grasping and the method of provision is expeced to need. 1. The situation, According to the data published from the year 1993 to 1997, their results are great different. But recent Korean embassy in China examined the situation of the Korean students, whose result was investigated as follows: about 1500 persons, their average age is 24 to 44, the ratio of male and female students is 3 to 1, that of their academic background which is a graduate of university : that of college : that of highschool is 1.6 : 1 : 4.7, and that of their class attitude which is direct : common : indirect appears the percents 30.4 : 52.8 : 16.8. 2. The controversial points (1) A lowering of standards on Chinese medical treatment is expected by the imprudent studying abroad without qualification. And because of excessive production of herb doctors, the amount of treatment may be above people's demand. Besides owing to the impossibility of prediction on the number the counterplans of our government may fall into utler confusion. (2) The curriculum, the teaching schedule and contents are so different that the graduates seem not to be given real education of chinese medicine from the point of Korean view. (3) In the wrong national examination, the important thought of china, and the system of WTO in Korea, when China will become mighty rival above problems contain the negative sides. 3. The counterplans - what should be performed soon. (1) Illegal contents about studying abroadl in China ought to inform sidely that students might not go on increasing. Before they form nam-power, the government and the field of chinese medicine should cope with such a situation together. (2) The law of regulation about agents should be legislated and they should be surpervised. (3) The exact numbers of students, their situation, and the present condition of each university should be examined. (4) After investigating the problems of the present system of national test, its enforcement and many counterplans is requisite. (5) The cooperating confrontation with the conference of dentistry is in need. (6) Since the problems are possibility to be developed to diplomatic questions, the effort of both nations is needful. - what need middle of long time. (1) The effort that suppress the more establishment of the college of oriental medicine is necessary. (2) After comparing with the system of foreign test, the government should make the system of test in accord with the mutualism and the principle of indiscrimination among nations and cope with such a many issues thoroughly.

• Journal of The Korean Association For Science Education
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• v.22 no.3
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• pp.632-648
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• 2002

The purpose of this study was to investigate a process of change which was made by a science teacher for one-year long in-service education program in terms of constructivist teaching behaviors and beliefs. The in-service program was featured by the use of learning cycle model and Science-Technology-Society approach. One of science teachers, who attended an one-year long in-service program was selected for this study. She developed three teaching materials for the duration. The three teaching materials were analyzed to find components of Science-Technology-Society and the integration of science content and real life context. Also, an interview was performed to assess changes in her perspectives on science, science teaching and science learning through the program. The first material was constructed in the form of learning cycle with little emphasis on STS. The second material was embedded with personal matters such as a refrigerator. The final one was shown to be organized with science content in a personal context and with focus on the role play. The interview also showed that her perspectives on science and science teaching have changed toward the constructivist's during the participation in the in-service program. It is suggested that a long-term in-service program should be developed and implemented so that the science teachers may become constructivist teachers.

• Phonetics and Speech Sciences
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• v.12 no.1
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• pp.33-42
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• 2020

This study identified the substitution of /u/ for /o/ (e.g., pyəllo [pyəllu]) in Korean based on the speech corpus as a function of grammar items. Korean /o/ and /u/ share the vowel feature [+rounded], but are distinguished in terms of tongue height. However, researchers have reported that the merger of Korean /o/ and /u/ is in progress, making them indistinguishable. Thus, in this study, the frequency of the phonetic manifestation /u/ of the underlying form of /o/ for each grammar item was calculated in The Korean Corpus of Spontaneous Speech (Seoul Corpus 2015) which is a large corpus from a total of 40 speakers from Seoul or Gyeonggi-do. It was then confirmed that linking endings, particles, and adverbs ending with /o/ in the word-final position were substituted for /u/ approximately 50% of the stimuli, whereas, in nominal items, they were replaced at a frequency of less than 5%. The high rates of substitution were the special particle "-do[du]" (59.6%) and the linking ending "-go[gu]" (43.5%) among high-frequency items. Observing Korean pronunciation in real life provides deep insight into its theoretical implications in terms of speech recognition.