• Tribology and Lubricants
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• v.35 no.1
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• pp.59-64
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• 2019

When slipping occurs between two materials, the coefficients of friction must be considered because these values determine the overall efficiency of the machine or slip characteristics. Therefore, it is important to find the coefficient of friction between two materials. This paper focuses on obtaining the coefficient of friction between an aiming bolt and a retainer located in the headlamps of a vehicle. This bolt supports the headlamp, and if the bolt is loosened by external vibration, the angle of the light will change and block the vision of pedestrians or other drivers. In order to study these situations, the coefficient of friction between aiming bolts and retainers needs to be measured. In addition, the coefficient of friction of materials used in the headlamp should be obtained. To determine these two factors, a new device is designed for two cases: surface-surface contact and surface-line contact. To increase reliability of the results, the device is designed using an air-bearing stage which uses compressed air as lubricant to eliminate the friction of the stage itself. Experiments were carried out by applying various vertical forces, and the results show that the coefficient of friction can be measured consistently. The procedure for designing the device and the results are discussed.

• Journal of Convergence for Information Technology
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• v.9 no.7
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• pp.114-121
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• 2019

This study examined the Knowledge of Elementary School Teachers Regarding in ADHD Children Education of ADHD children education for 297 elementary school teachers. The knowledge of ADHD children in inclusive education was made through a questionnaire composed of four areas: attitude, burden, efficacy, and promotional conditions on ADHD children. The collected questionnaire was calculated using technical statistics from the SPSS (WIN 22.0) for frequency and percentage. The results of this study are as follows: First, the teachers of general elementary schools are trying to include education of ADHD children. Second, in the burden of general elementary school teachers on ADHD children education, ADHD children showed interruption of learning, interruption of positive learning atmosphere, interruption of order maintenance of general classroom and teacher's class progress. Third, in the efficacy of general elementary school teachers on ADHD children, they did not have the Knowledge of ADHD symptoms, diagnosis and evaluation of ADHD children, teaching ability for ADHD children education, and ability to deal with ADHD children's behavior. Fourth, in the promotion condition of school for ADHD child education, it was found that there was no connection with external institutions for the support of professional manpower for ADHD children and ADHD child supports.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.823-824
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• 2016

In general, distribution board, panel board and motor control center can be installed over a wide area such as residence of group, building, schools, factories, ports, airports, water service and sewerage, substation and heavy industries that are used to supply converts the voltages extra high voltage into optimal voltage. There are electrical accidents due to rise of contact temperature, loose contact of bus bar, deterioration of the contact resistance, overtemperatue of the bus bars. In this paper, we propose bus bar joints monitoring system with loose connection of bus bar, measuring the joint resistance of busbars and monitoring internal and external heat. The proposed system can be reduced the electrical accidents by maintenance of busbar joints and the temperature of the conductive contact surface of busbars.

• The Korean Journal of Archival Studies
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• no.34
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• pp.107-163
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• 2012

The share of the internet has grown significantly in terms of usage and level of influence. Among the internet media, OhmyNews is considered a alternative media representing Korea's independent internet news, and a typical example displaying characteristics of the internet news. The processing step can be divided as five stage, with recorded information and applicable technical element extractable from each stage. In this thesis paper, we have analyzed domestic and overseas metadata standard examples to devise metadata design plans. Items to be focused when redesigning metadata based on domestic and foreign case studies are as follows: First, user access should be convenient; second, connection with related information should be considered; third, accumulation of production, management, usage, storage, and action history should be considered; and fourth, the design should allow higher utilization of contents. In depth researches over internet media are already being carried out in external academic disciplines including the media information studies, information and communication studies, and communications studies. We expect that it will also be necessary to consider such researches over the internet media for mass media record management research going forward.

• Journal of the Korean Society for Library and Information Science
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• v.55 no.2
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• pp.5-24
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• 2021

This study suggested a plan to convert the modern literary data service of the National Library of Korea into linked data-based services. This is not to simply convert the modern literary data service into linked data, which is the current technological trend. This is to create high-quality source data capable of automated machine processing with continuous connection with various external data and information sources in the long term. To this end, in order to revitalize the service of modern literature and to solve the efficient data linkage with related institutions, various overseas library and bibliographic service cases that adopted linked data were first reviewed to draw implications. In addition, based on the reviewed implications, the plan to reorganize the modern literary service in terms of data management, system management, and user service was described in detail.

• Advances in concrete construction
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• v.11 no.1
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• pp.33-43
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• 2021

A new type of composite insulated concrete sandwich wall (ICS-wall), which is composed of a triangle truss steel wire network, an insulating layer, and internal and external concrete layers, is proposed. To study the mechanical properties of this new ICS-wall, tensile, compression, and shearing tests were performed on 22 specimens and tensile strength and corrosion resistance tests on 6 triangle truss joints. The variables in these tests mainly include the insulating plate material, the thickness of the insulating plate, the vertical distance of the triangle truss framework, the triangle truss layout, and the connecting mode between the triangle truss and wall and the material of the triangle truss. Moreover, the failure mode, mechanical properties, and bearing capacity of the wall under tensile, shearing, and compression conditions were analyzed. Research results demonstrate that the concrete and insulating layer of the ICS-wall are pulling out, which is the main failure mode under tensile conditions. The ICS-wall, which uses a graphite polystyrene plate as the insulating layer, shows better tensile properties than the wall with an ordinary polystyrene plate. The tensile strength and bearing capacity of the wall can be improved effectively by strengthening the triangle truss connection and shortening the vertical distances of the triangle truss. The compression capacity of the wall is mainly determined by the compression capacity of concrete, and the bonding strength between the wall and the insulating plate is the main influencing factor of the shearing capacity of the wall. According to the tensile strength and corrosion resistance tests of Austenitic stainless steel, the bearing capacity of the triangle truss does not decrease after corrosion, indicating good corrosion resistance.

• Korean Journal of Head & Neck Oncology
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• v.38 no.1
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• pp.53-57
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• 2022

Reconstruction of subtotal maxillectomy defects with columella deficit is challenging. We report a unique case of facial reconstruction using a free radial forearm flap and a free preauricular flap for the maxillectomy and columella deficit. A 73-year-old woman was diagnosed with recurrent sebaceous carcinoma of the nose. We performed wide excision, including areas of the right cheek, nose, upper lip, maxilla, and columella. The resultant subtotal maxillectomy defect was reconstructed using a three-dimensional flap. First, a free radial forearm flap was transfered to resurface the nasal, oral, and external facial side. Second, a preauricular flap was positioned into the columella defect and anastomosed with the distal portion of the radial forearm flap pedicle. The two flaps survived, and the patient recovered uneventfully. We believe the radial forearm and preauricular double free flaps with the pedicle connection method were effective in reconstructing the present case of subtotal maxillectomy defect.

• Journal of the Korean School Mathematics Society
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• v.25 no.2
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• pp.175-194
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• 2022

This study intends to suggest implications by comparing the high school mathematics curricula between Korea and the UK ahead of the 2022 revision of the mathematics curriculum. The UK has revised assessments to emphasize mathematics after age 16 since 2017. Thus, in this study, the contents of Key Stage 4, Core Maths and A-level, which correspond to the UK high school mathematics curriculum, were examined and compared with Korean high school math subjects. In the UK, mathematics education is more emphasized at the high school level. The national curriculum emphasized 'numeracy and mathematics', and students' selection for mathematics courses were expanded. In order to prepare for the future society, new mathematics subjects and evaluations were developed and implemented, and the A-level mathematics was improved. In addition, the subject-centered content was developed and continuously handled from Key Stage 3 to the high school stage. It was structured to facilitate mathematics' internal and external connection by linking it with the subjects of other areas.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.1
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• pp.1-14
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• 2010

It is recently issued scalability, mobility and external internet connection on Wire-less sensor network. The low power wireless sensor networks based on IPv6 technology 6LoWPAN technology is being standardized in the IETF. This paper for the 6LoWPAN environment based on the routing protocol LOAD, route cost applied the packet re-transmission rate which follows in Link Qualities price which uses at course expense and packet transmission Minimum route Cost routing protocol where does on the course wherethe smallest packet re-transmission becomes accomplished proposed. The technique which proposes compared and LOAD and AODV that about 13%, about 16% energy consumption is few respectively averagely, Energy of the entire network equally, used and energy effectiveness and improvement of network life time experiment led and confirmed.

• Journal of the Earthquake Engineering Society of Korea
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• v.27 no.1
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• pp.37-47
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• 2023

A new clamped mechanical splice system was proposed to develop structural performance and constructability for precast concrete connections. The proposed mechanical splice resists external loading immediately after the engagement. The mechanical splices applicable for both large-scale rebars for plants and small-scale rebars for buildings were developed with the same design concept. Quasi-static lateral cyclic loading tests were conducted with reinforced and precast concrete members to verify the seismic performance. Also, shaking table tests with three types of seismic wave excitation, 1) random wave with white noise, 2) the 2016 Gyeongju earthquake, and 3) the 1999 Chi-Chi earthquake, were conducted to confirm the dynamic performance. All tests were performed with real-scale concrete specimens. Sensors measured the lateral load, acceleration, displacement, crack pattern, and secant system stiffness, and energy dissipation was determined by lateral load-displacement relation. As a result, the precast specimen provided the emulative performance with RC. In the shaking table tests, PC frames' maximum acceleration and displacement response were amplified 1.57 - 2.85 and 2.20 - 2.92 times compared to the ground motions. The precast specimens utilizing clamped mechanical splice showed ductile behavior with energy dissipation capacity against strong motion earthquakes.