• Journal of Biomedical Engineering Research
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• v.18 no.4
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• pp.447-456
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• 1997

When the disabled is operating a rehabilitation assisting system with a joystick by himself, unlike in the case of a normal person, tremor with joystick control or instant miscontrol can often occur. If these misoperations should be directly relayed to the system, shaking or malfunction of the mobile rehabilitation assisting system might be the result. The safety of the disabled is of prime concern. To solve this problem, that is, to prevent the miscontrol of the disabled operator and avoid crashes into his or her surroundings, we propose the force-reflection locomotion algorithm with the joystick. This method uses ultrasonic sensors to measure the distance between the object and mobile robot. Based on the reception of sensory data, the necessary torque is applied via the joystick to the attatched motor. To confirm the effectiveness of the proposed method, the subjects on the reflected force by the dynamic characteristics of the joystick and the reflected force by the distance information are tested Even though there are some differences in human dexterity, we confirmed the fact that the information from the obstacles was relayed to the operator via the joystick and resulted in an improved operational performance and safety level with regard to those obstacles.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.4
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• pp.348-353
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• 2004

This study is aimed for the implementation of ultrasonic method to assess the reliability of turbine bearings. A modified ultrasonic immersion technique was carried out in both laboratory experiment and field application. From the laboratory results, we confirmed that the condition of interface layer between the babbitt and base metal be monitored by the C-Scan. The C-scan image by the ultrasonic immersion test can be used successfully to observe the condition of interface layer. The testing with a focused transducer provides a promising approach for estimating the extent of the damaged region and observing the interface layer effectively. The difference of the ultrasonic reflection ratio between the bonding and debonding area at the interface layer is one of the key parameters for assessing the extent of the damaged area; additionally, the reflection amplitude exhibits a favorable correlation with the overall damage level. The technique developed in this study was applied to the inspection of the turbine bearings at several power plants in Korea whereby the applicability in the field can be ascertained.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1D
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• pp.81-87
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• 2006

The rubblization technique is breaking the aged concrete pavement slab into rubblized concrete aggregate, and use it as an base material at its original position, then builds overlay above the rubblized base. This method has been successively used in USA due to the advantage of good constructibility, cost-effectiveness as well as the capability of preventing of reflection cracks. However, constructibility and economic performance of rubblization on typical Korean concrete pavements needed to be investigate since to typical Korean concrete pavements have thick slab, as well include lean concrete subbase course. Multi-head type breaker suitable for Korean condition was designed and developed. This multi-head type breaker was designed to rubblize old concrete to the suggested optimum rubblized-depth and rubblized-concrete-aggregate size to prevent reflection crack and maintain high bearing capacity. This machine was used for the test of rubblization of old concrete pavement on a non-use old concrete and a in-serviced road. In these two tests, engineering properties of rubblized base and constructability and cost were investigated. In both tests, the old concrete rubblized to targeted size and depth, and high-level bearing capacity was achieved. Also, superior constructability and lower cost compared with traditional reconstruction was examined.

• Journal of the Korean Chemical Society
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• v.58 no.3
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• pp.324-337
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• 2014

This study investigated the characteristics of science-gifted elementary students' reflection of their science classes. To do this, 91 reflective journals of 20 science-gifted elementary students were analyzed in terms of 'productive reflection'. The results revealed that the mean score of the inclusion scores, which mean the number of aspects of teaching included, was 2.99 on a scale of 5 points and was not significantly correlated with grade level. Most of the reflective journals included the aspects of 'science-gifted students (93.4%)'. 'Instructional strategies and instruction for science-gifted education (70.3%)', 'subject matter knowledge (68.1%)', and 'curriculum for science-gifted education (57.1%)' were also frequently included. However, 'assessment in science-gifted education (9.9%)' was hardly included. The mean score of the integration scores, which mean the number of aspects of teaching integrated as an index of productive reflection, was 2.84 on a scale of 5 points and was not significantly correlated with grade level. 6.6% of the journals showed no integrations. 34.1% of the journals integrated only two aspects, 39.6% of the journals integrated three aspects, 25.3% of the journals integrated four aspects, and no journals integrated all five aspects. Especially, the integrations between 'science-gifted students (100.0%)' and the other aspects were included in all journals. The integrations between 'instructional strategies and instruction for science-gifted education (70.3%)' and/or 'subject matter knowledge (65.9%)' and/or 'curriculum for science-gifted education (53.8%)' and the other aspects were also frequently included. However, the integrations between 'assessment in science-gifted education (9.9%)' and the other aspects were hardly included. There were no statistically significant differences between experiment-centered instruction and theory-centered instruction in the inclusion and integration scores. However, there were more diverse inclusion and integration types, and more aspects tended to be included or integrated in experiment-centered instruction than in theory-centered instruction.

• Korean Institute of Interior Design Journal
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• v.21 no.5
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• pp.289-297
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• 2012

Recently the coffee industries rapidly grow as people's dietary life changes and quality of life improves. Proliferation of coffeehouses let people cognize them as cultural spaces not only mere spaces for drinking coffee beverages. Therefore, distinguished strategy for space design became the one of the most important factor for customers' decision-making. This study analysed the strategies for space design by the brands of coffeehouses, and focused on understanding how those strategies cognized by customers and how they affect customers' level of satisfaction and intention of revisitation. The result of analysis showed that the level of satisfaction was raised when customers cognized unique strategies by brands and the intention of revisitation was raised when the level of satisfaction and reflection of strategy were high. In other words, setting and applying unique strategies by brands are to raise up level of satisfaction and intention of revisitation. The result of study could be used for the basic data on designing coffeehouses attracting customers' revisitation. Also, it could be the basis for effective strategy for customers.

• Journal of the Korea Concrete Institute
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• v.15 no.6
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• pp.924-929
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• 2003

A majority of infrastructures has been deteriorated over time. Therefore, it is very important to verify the quality of construction, and the level of structural deterioration in existing structures, to ensure their safety and functionality. Many researchers have studied non-destructive testing (NDT) methods to identify structural problems in existing structures. The impact echo technique is one of the widely used NDT techniques. The impact echo technique has several inherent problems, including the difficulties in P-wave velocity evaluation due to inhomogeneous concrete properties, deterioration of evaluation accuracy where multiple reflection boundaries exist, and the influence of the receiver location in evaluating the thickness of the tested structures. Therefore, the objective of this paper is to propose an enhanced impact echo technique that can reduce the aforementioned problems and develop a Virtual Instrument for the application via a thickness evaluation technique which has same technical background to find deterioration in concrete structures. In the proposed impact echo technique, transfer function from dual channel system analysis is used, and coherence is improved to achieve reliable data. Also an averaged signal -ensemble- is used to achieve more reliable results. From the analysis of transfer function, the thickness is effectively identified.

• Korean Institute of Interior Design Journal
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• v.18 no.4
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• pp.43-50
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• 2009

Design trend, transparency, which has been developed under a reflection of current periodic environment, has been exposed to people all over the world through varieties of architecture facade and interior space. As interior space follows this trend, which has difference in showing space from the past, transparency becomes an important measure of showing openness of certain space. Main objective of this research is to understand a characteristics of materials that leads transparency a important measure to the modern interior design, and this will set the range to this applicable materials for appropriate areas of defining transparency in an interior. Characteristic uses of transparent materials found in this research which leads transparency into interior space are described below: First, there are two perspectives in transparency. One is visibility and material wised transparency and the other is conditional and spacial wised transparency. With this knowledge, we can expand a level of transparency with ideas such as clarity, opacity, visible transmission, and reflection, and this broadened range will vary the acceptable materials used to show transparency. Second, transparent materials are used with many different purposes in modern interior space as furnitures, sanitary fixtures, partitions, and other structures. With using modern technology in reforming this materials brought new methods in structure composing. last, transparent materials' expnt pable characteristics made modern interior space to have a control over spacial homogeneity, a simplified octlines, weakened boundaries, and compositional effects by interference and vision.

• Journal of Magnetics
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• v.10 no.4
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• pp.163-170
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• 2005

The RF integrated noise filters are fabricated by photolithography. The stack for the electromagnetic noise filters consists of the nano-granular ($Co_{41}Fe_{38}AI_{13}O_8$) soft magnetic film / $SiO_2$ / Cu transmission line / seed layer (Cu/Ti) / $SiO_2$-substrate. A good signal-attenuation feature along with a low signal-reflection feature is observed in the present filters. Especially in the noise filter incorporated with a $Co_{41}Fe_{38}AI_{13}O_8$ magnetic film with lateral dimensions of $2000{\mu}m$ wide, 15 mm long and $1{\mu}m$ thick, the maximum magnitude of signal attenuation reaches -55 dB, and the magnitude of signal reflection is below -10 dB in the overall frequency range. And this level of signal attenuation is much larger than that of a noise filter incorporated with a Fe magnetic film.

• Journal of Korea Society of Digital Industry and Information Management
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• v.20 no.1
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• pp.75-85
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• 2024

This study explored the overall perception of teaching media from the perspective of pre-service teachers. For this purpose, reflection journals written by 138 pre-service teachers were analyzed, and positive and negative perceptions of teaching media were explored. In the reflection diary, pre-service teachers were asked to write down examples of appropriate use of instructional media and the effects of their experiences, cases of inappropriate use of instructional media, and areas requiring improvement. The main research results are as follows. First, the positive aspects of teaching media perceived by prospective teachers were that it presented examples that could help understanding, aroused curiosity to focus attention, and encouraged participation to motivate learning. Second, the negative aspects of teaching media perceived by prospective teachers include cases where the playback time of the video containing learning content is excessively long and the content of the video is unclear or is higher than the learner's level and difficult to understand. This study is significant in that it presents pre-service teachers experiences and perceptions of teaching media and their desirable use methods.

• Journal of The Korean Association For Science Education
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• v.31 no.8
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• pp.1092-1109
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• 2011

The purpose of this study was to analyze of the effects of instructional supervision emphasizing reflective thinking on science teaching of elementary teachers. The participants in this study were two teachers. This study was divided in former, middle, and later periods, and consisted of monitoring their own teaching, interviewing, journal writing, discussion with peer teachers and teacher training. Data included descriptions of nine science classes, nine interviews, seven journals and the journals of the researcher. Data analysis tools were the frameworks of the questions, feedback, teaching methods, elements of teaching behavior, and reflection levels. This study employed qualitative research, analysis of the frequency of data, and quoting of descriptions related to the result. The results of this study were as follows: First, teachers showed mainly technical reflection, but changed to show more practical reflection, and critical reflection in the later period of instructional supervision. Second, instructional supervision emphasizing reflective thinking on science teaching for elementary teachers meaningfully changed the question, feedback, teaching methods and teaching elements of teachers. From the results of this study, instructional supervision emphasizing reflective thinking on science teaching for elementary teachers can be considered an effective method in improving teaching elementary science, and instructional supervision used in this study made possible the higher level of reflection and appropriate teaching behavior.