• The Journal of the Korean dental association
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• v.52 no.12
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• pp.734-743
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• 2014

Objectives: By introduced reciprocation motion file in dentistry, dentists benefit simple canal shaping procedure and time-saving. But, reciprocation motion generates uncomfortable vibration to doctors and patients. Because there was no study about this consideration, this study compared vibration pattern and power generated from reciprocation motion motor and conventional rotary motor. Materials & Methods: One conventional rotary motor; X-Smart (Dentsply Maillefer, Ballaigues, Switzerland); and two reciprocating motors; WaveOne Motor (Dentsply Maillefer, Ballaigues, Switzerland) and X-SMART PLUS (Dentsply Maillefer, Ballaigues, Switzerland); were used in this study. Triaxial $ICP^{(R)}$ Accelerometer (Model 356A12, PCB piezotronics, New York, USA) was attached on motor's handpiece head, and was measured tri-axial vibratory acceleration with NI Sound and Vibration Assistant 2009 software (National Instruments, Texas, USA). Mean vibratory acceleration and maximum vibratory acceleration was measured on fixed position and handed position. The results of vibratory acceleration were statistically analyzed using ANOVA and multiple comparisons are made using Turkey's test at p<0.05 level. Results: Reciprocating motors showed higher mean vibratory acceleration and maximum vibratory acceleration than conventional rotary motor (p<0.05). Between reciprocating motors, X-SMART PLUS had lower mean vibratory acceleration and maximum vibratory acceleration than WaveOne Motor (p<0.05). Conclusion: Reciprocating motors generate more vibration than conventional rotary motor. Further study about effect of vibration to dentist and patient is needed. And it seems to be necessary to make a standard about vibration level in endodontic motors.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.8
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• pp.67-73
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• 2021

In this study, we installed forward and reverse rotation rotavators on a tractor to measure the load in the field and analyze the power consumed. The rotavator is attached to the rear of the tractor and transmits the power applied from the power take off (PTO) of the tractor to the rotating shaft of the rotavator, and it plows or reverses the soil according to the rotational direction of the rotating shaft. Depending on the rotational direction of the rotavator, the power consumed in the tractor engine and the power transmitted to the tractor axle and rotavator also vary, thus, research of load and power is an essential factor in designing the system. As a field test results, 84.1-93.5% power was consumed by the forward rotation rotavator, and 37.8-57.5% power was consumed by the reverse rotation rotavator. In addition, depending on the rotation direction of the rotavator, the power consumed by the tractor was in the order of PTO and axle. Based on the research results, development of reliable rotavator systems would be possible in the future research.

• Smart Structures and Systems
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• v.29 no.2
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• pp.375-387
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• 2022

One of the latest teaching strategies is smart classroom teaching. Teaching is carried out with the assistance of smart teaching technologies to improve teacher-student contact, increase students' learning autonomy, and give fresh ideas for the fulfillment of students' deep learning. Computer-based technology has improved students' language learning and significantly motivating them to continue learning while also stimulating their creativity and enthusiasm. However, the difficulties and barriers that many EFL instructors are faced on seeking to integrate information and communication technology (ICT) into their instruction have raised discussions and concerns regarding ICT's real worth in the language classroom. This is a case study that includes observations in the classroom, field notes, interviews, and written materials. In EFL classrooms, both computer-based and non-computer-based activities were recorded and analyzed. The main instrument in this study was a survey questionnaire comprising 43 items, which was used to examine the efficiency of ICT integration in teaching and learning in public schools in Kuala Lumpur. A total of 101 questionnaires were delivered, while each responder being requested to read the statements provided. The total number of respondents for this study was 101 teachers from Kuala Lumpur's public secondary schools. The questionnaire was randomly distributed to respondents with a teaching background. This study indicated the accuracy of utilizing Teaching-Learning-Based Optimization (TLBO) in analyzing the survey results and potential for students to learn English as a foreign language using computers. Also, the usage of foreign language may be improved if real computer-based activities are introduced into the lesson.

• Smart Structures and Systems
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• v.8 no.3
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• pp.303-320
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• 2011

Comparing to active damage monitoring, impact localization on composite by using time reversal focusing method has several difficulties. First, the transfer function of the actuator-sensor path is difficult to be obtained because of the limitation that no impact experiment is permitted to perform on the real structure and the difficulty to model it because the performance of real aircraft composite is much more complicated comparing to metal structure. Second, the position of impact is unknown and can not be controlled as the excitation signal used in the active monitoring. This makes it not applicable to compare the difference between the excitation and the focused signal. Another difficulty is that impact signal is frequency broadband, giving rise to the difficulty to process virtual synthesis because of the highly dispersion nature of frequency broadband Lamb wave in plate-like structure. Aiming at developing a practical method for on-line localization of impact on aircraft composite structure which can take advantage of time reversal focusing and does not rely on the transfer function, a PZT sensor array based phase synthesis time reversal impact imaging method is proposed. The complex Shannon wavelet transform is presented to extract the frequency narrow-band signals from the impact responded signals of PZT sensors. A phase synthesis process of the frequency narrow-band signals is implemented to search the time reversal focusing position on the structure which represents the impact position. Evaluation experiments on a carbon fiber composite structure show that the proposed method realizes the impact imaging and localization with an error less than 1.5 cm. Discussion of the influence of velocity errors and measurement noise is also given in detail.

• Journal of The Korean Association of Information Education
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• v.19 no.2
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• pp.175-186
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• 2015

In this study, we developed the PATROL teaching and learning model by using digital textbooks in Smart Classrooms to correct the disadvantages of Flipped Classrooms. PATROL is an acronym for Planning, Action, Tracking, Recommending, Ordering, and Leading. In the Planning phase, teachers should make a lesson plan. Next, students take Action by watching online contents and completing assignments in their digital textbook. After that, Tracking is needed to analyze the students' activities and the results. Then, Recommending is used to provide suggested instructional activities to teachers based on that analysis. Next, Ordering requires that students request new materials for class activities. Finally, Leading allows teachers to provide materials at the appropriate level to their students based on the students' learning activities. Applying the PATROL model at two elementary schools resulted in an increase in student-directed speech as well as an increase in the number of group and individual activities. Teachers also had more time to walk around the classroom.

• Journal of Fashion Business
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• v.20 no.1
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• pp.142-156
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• 2016

Convergence of IT devices and fashion is enabling the industry to take fully different approaches in various areas including product planning, fabric selecting, distributing, and marketing. At the same time, it also transforms the definition of clothing itself. Convergence of IT technologies in the realm of fashion and textiles industries can create a powerful synergy through connection digital devices, such as mobile phone. In this context, this study attempts to suggest how IT technology can be efficiently harnessed through the usage of mobile devices in the planning stage of fashion materials, where the initial production plan of a clothing item is mapped out. This study ultimately aims to enhance the effectiveness of databases on fashion material information by using mobile devices to utilize NFC, an RFID technology having as much revolutionary power as Internet - which can be the convergence between IT and fashion across the software dimensions. To pursue this research, data on fashion material information regarding 200 woven fabric specimens were provided by textile companies. The information includes elements such as its composition, weight, width, yarn, density and sales report. These pieces of information were organized into a database. Drawing on this data, Android-based applications that allow smart phones to read off fabric information from NFC tags were developed for this study using two methods. The system works as follows: 1. NFC tag stickers are attached onto the hangers where 200 fabric samples are hanging. 2. The NFC tag stickers are tagged, or read off from a smart phone that support NFC functions. 3. Upon tagging, the Smart phone swiftly displays all information available on its screen - not only the aforementioned six elements, but also the image of the clothing item from the fabric in its finalized product form, and the video of the model wearing the item - for convenient view. The method harbors immense potential for the fashion industry in general, and will also be useful in those fields inside the industry that harness NFC technology.

• Biomaterials and Biomechanics in Bioengineering
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• v.2 no.1
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• pp.47-59
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• 2015

A bioactive and multifunctional elastin-like polymer (ELP) was produced by genetic engineering techniques to develop new artificial matrices with the ability to mimic the extracellular matrix (ECM). The basic composition of this ELP is a thermo- and pH-sensitive elastin pentapeptide which has been enriched with RGD-containing domains, the RGD loop of fibronectin, for recognition by integrin receptors on their sequence to promote efficient cell attachment. Hydrogels of this RGD-containing polymer were obtained by crosslinking with hexamethylene diisocyanate, a lysine-targeted crosslinker. These materials retain the "smart" nature and temperature-responsive character, and the desired mechanical behavior of the elastin-like polymer family. The influence of the degree of crosslinking on the morphology and properties of the matrices were tested by calorimetric techniques and scanning electron microscopy (SEM). Their mechanical behavior was studied by dynamical mechanical analysis (DMA). These results show the potential of these materials in biomedical applications, especially in the development of smart systems for tissue engineering.

• Fashion & Textile Research Journal
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• v.23 no.5
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• pp.655-666
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• 2021

This study aims to classify wearable devices for infants and children according to their function, and to analyze the types and attachment methods of the devices by function, operating system, characteristics of materials, and types of batteries, and to identify the points for improvement. Forty-eight types of devices investigated through previous studies and keyword research online were analyzed. Wearable devices for infants and children were classified according to their functions into wearable monitors, wearable thermometers, GPS trackers, and smart watches. Devices had different shapes and attachment methods according to their functions, and were mainly clothes or accessory types. The accessory type devices were attached to the body using velcro, clips, bands, or adhesives. Wearable monitors and thermometers mainly used Bluetooth to transmit data wirelessly, and location trackers used various combinations of 4G(LTE), 5G networks, GPS, Wi-Fi, and Bluetooth. Smartwatches had different functions depending on whether smart phones were linked to them or not. Wearable monitors and thermometers mainly used by infants provided material information, but other devices did not. These devices used rechargeable, replaceable, non-rechargeable or non-replaceable batteries. Wearable devices need to be improved to reduce the discomfort experienced by infants and children due to the attachment position, malfunction, skin trouble caused by materials, short time of use of batteries, version conflict and complexity with the device when linking with a smart phone, and non-operation when using Bluetooth.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.5
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• pp.203-208
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• 2021

At the manufacturing site, workers have been operating by inputting materials into the manufacturing process and leaving input records according to the work instructions, but product LOT tracking has been not possible due to many omissions. Recently, it is being carried out as a system to automatically input materials using RFID-Tag. In particular, the initial automatic recognition rate was good at 97 percent by automatically generating input information through RACK (TAG) ID and RACK input time analysis, but the automatic recognition rate continues to decrease due to multi-material RACK, TAG loss, and new product input issues. It is expected that it will contribute to increasing speed and yield (normal product ratio) in the overall production process by improving automatic recognition rate and real-time monitoring through the establishment of artificial intelligent smart factory datasets.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.12
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• pp.136-144
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• 2021

The purpose of this study was to develop and verify a precision transmission error measurement system for a gear pair. The transmission error measurement system of the gear pair was developed as a measurement unit, signal processing unit, and signal analysis unit. The angular displacement for calculating the transmission error of the gear pair was measured using an encoder. The signal amplification, interpolation, and transmission error calculation of the measured angular displacement were conducted using a field-programmable gate array (FPGA) and a real-time processor. A high-pass filter (HPF) was applied to the calculated transmission error from the real-time processor. The transmission error measurement test was conducted using a gearbox, including the master gear pair. The same test was repeated three times in the clockwise and counterclockwise directions, respectively, according to the load conditions (0 - 200 N·m). The results of the gear transmission error tests showed similar tendencies, thereby confirming the stability of the system. The measured transmission error was verified by comparing it with the transmission error analyzed using commercial software. The verification showed a slight difference in the transmission error between the methods. In a future study, the measurement and analysis method of the developed precision transmission error measurement system in this study may possibly be used for gear design.