• Restorative Dentistry and Endodontics
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• 제48권2호
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• pp.15.1-15.7
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• 2023

Objectives: This study evaluated the efficiency of WaveOne Primary files (Dentsply Sirona) for removing root canal fillings with 2 types of movement: reciprocating (RCP) and continuous counterclockwise rotation (CCR). Materials and Methods: Twenty mandibular incisors were prepared with a RCP instrument (25.08) and filled using the Tagger hybrid obturation technique. The teeth were retreated with a WaveOne Primary file and randomly allocated to 2 experimental retreatment groups (n = 10) according to movement type: RCP and CCR. The root canals were emptied of filling material in the first 3 steps of insertion, until reaching the working length. The timing of retreatment and procedure errors were recorded for all samples. The specimens were scanned before and after the retreatment procedure with micro-computed tomography to calculate the percentage and volume (mm³) of the residual filling material. The results were statistically evaluated using paired and independent t-tests, with a significance level set at 5%. Results: No significant difference was found in the timing of filling removal between the groups, with a mean of 322 seconds (RCP) and 327 seconds (CCR) (p < 0.05). There were 6 instrument fractures: 1 in a RCP motion file and 5 in continuous rotation files. The volumes of residual filling material were similar (9.94% for RCP and 15.94% for CCR; p > 0.05). Conclusions: The WaveOne Primary files used in retreatment performed similarly in both RCP and CCR movements. Neither movement type completely removed the obturation material, but the RCP movement provided greater safety.

• The Journal of Korean Physical Therapy
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• 제24권2호
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• pp.118-126
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• 2012

Purpose: The purpose of this study was to investigate pain relief and functional recovery after total knee replacement. Methods: The treatment was performed by dividing individuals into a control group ($n_1=5$), ultrasound treatment group ($n_2=5$), and micro-current treatment group ($n_3=5$). The control group applied the hot pack for 15 minutes, Transcutaneous Electrical Nerve Stimulation (TENS) for 15 minutes, and Continuous Passive Movement (CPM) for 40 minutes. The ultrasound therapy group applied the frequency of 1 MHz, intensity of 1.0 $W/cm^2$ for five minutes following the same treatment as the control group. The micro-current therapy group applied the intensity of 25 ${\mu}A$, and pulsation frequency 5 pps for 15 minutes following the same treatment as the control group. After treatment, Visual Analogue Scale (VAS), Korean Western Ontario and McMaster Universities Arthritis Index (K-WOMAC), Berg Balance Scale (BBS), Range of Movement (ROM) and wound length was measured. Results: VAS showed significant effect in the control group and micro-current therapy group during the treatment period. According to the treatment of K-WOMACK, BBS, ROM, and Healing wounds showed main effects between groups. Conclusion: According to the results of this study, data showed improvement of pain relief, wound healing effects, and range of motion recovery. Thus, these selected treatments were effective after total knee replacement. In other words, electrical treatment continues to influence pain relief and functional recovery after total knee replacement.

• 한국IT서비스학회지
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• 제20권6호
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• pp.83-95
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• 2021

In this study, various usage patterns were analyzed after establishing a data mart for micro mobility analysis based on the rental history of public bicycles in Seoul. Rental history data is origin-destination data that includes the rental location and time, and the return location and time. About 1500 rental locations were classified according to the characteristics of the location to create a 'station type' dimension. We also created a 'path type' dimension that displays whether the rental location and return location are the same. In addition, a derived variable called speed, which is obtained by dividing the distance used by the time used, is added, and through this, the characteristics of the riding area and the reason for the rental can be estimated. Meanwhile, administrative district link, administrative neighborhood link, and station type link were created to apply network analysis. Through this analysis, the roles and proportions of administrative districts, public facilities, and private facilities engaged in micro-mobility services were visualized. 49.9% of rentals occur at rental offices near transportation facilities, and half of them occur at rental offices near subway stations. The number of rentals during the evening rush hour is more than double that of the morning rush hour. When the path type is unidirectional, there is a fixed destination, so the distance and time used are short, and the movement speed tends to be high. In the case of round-trip, the purpose of use is exercise or leisure, so the distance and time used are long, and the movement speed is slow. It is expected that the results of the analysis can be used as reference materials for selecting new rental locations, providing convenient services for users, and developing user-specialized products.

• 대한치과교정학회지
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• 제47권4호
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• pp.229-237
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• 2017

Objective: The aim of this study was to compare the initial stability as insertion and removal torque and the clinical applicability of novel orthodontic zirconia micro-implants made using a powder injection molding (PIM) technique with those parameters in conventional titanium micro-implants. Methods: Sixty zirconia and 60 titanium micro-implants of similar design (diameter, 1.6 mm; length, 8.0 mm) were inserted perpendicularly in solid polyurethane foam with varying densities of 20 pounds per cubic foot (pcf), 30 pcf, and 40 pcf. Primary stability was measured as maximum insertion torque (MIT) and maximum removal torque (MRT). To investigate clinical applicability, compressive and tensile forces were recorded at 0.01, 0.02, and 0.03 mm displacement of the implants at angles of $0^{\circ}$, $10^{\circ}$, $20^{\circ}$, $30^{\circ}$, and $40^{\circ}$. The biocompatibility of zirconia micro-implants was assessed via an experimental animal study. Results: There were no statistically significant differences between zirconia micro-implants and titanium alloy implants with regard to MIT, MRT, or the amount of movement in the angulated lateral displacement test. As angulation increased, the mean compressive and tensile forces required to displace both types of micro-implants increased substantially at all distances. The average bone-to-implant contact ratio of prototype zirconia micro-implants was $56.88{\pm}6.72%$. Conclusions: Zirconia micro-implants showed initial stability and clinical applicability for diverse orthodontic treatments comparable to that of titanium micro-implants under compressive and tensile forces.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2015년도 임시총회 및 하계학술연구발표회
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• pp.161-163
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• 2015

The micro device, coil, and channel for the biosensor integrated with the GMR-SV device based on the antiferromagnetic IrMn layer was fabricated by the light lithography process. When RBCs coupled with several magnetic beads with a diameter of $1{\mu}m$ passed on the micro channel, the movement of RBC + ${\mu}Beads$ is controlled by the electrical AC input signal. The RBC + ${\mu}Beads$ having a micro-magnetic field captured above the GMR-SV device is changed as the output signals for detection status. From these results, the GMR-SV device having the width magnitude of a few micron size can be applied as the biosensor for the analysis of a new magnetic property as the membrane's deformation of RBC coupled to magnetic beads.

• 한국사회복지학
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• 제65권2호
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• pp.255-285
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• 2013

본 논문은 자활사업을 주요사례로 정부의 사회복지사업에 민간파트너로 참여하고 있는 사회운동조직이 어떻게 전문 사회복지기관과의 역학관계 속에서 자신의 자발적 정체성을 방어해나가는지 살펴보고자 한다. 군부독재가 막을 내리고 민주화와 진전되면서 과거 정부와 대립하던 사회운동단체들이 복지정책의 주요파트너로 부상했다. 저소득층의 일자리 지원사업인 자활사업도 빈민 실업운동진영과의 협력으로 도입된 복지제도이다. 그러나 사회운동에 대한 기존연구들은 사회운동조직이 제도화되면서 자발성이 훼손되고 사회복지 전문가와 기관들에게 헤게모니를 내놓게 된다고 지적해왔다. 이에 본 연구는 자활사업 관련 역사문헌, 심층면접, 참여관찰 자료에 대한 역사적 담론 분석을 통해, 자활사업의 도입시기부터 현재까지 사회운동조직의 자활사업 내 입지변화와 운동조직이 일선현장에서 사회복지진영으로부터 자신을 구별하기 위해 각 국면마다 구사해온 담론과 전략들이 있는지 추적했다. 본 논문은 사회운동과 사회복지의 갈등의 역사 속에서 사회운동진영의 생존전략들을 살펴봄으로써, 사회운동의 사회복지제도화와 전문화를 단지 사회운동의 지배체계로의 편입, 흡수, 종속으로 설명할 수 없고, 그 이면에 사회운동조직의 미시저항이 존재함을 드러내고자 했다.

• 대한치과교정학회지
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• 제51권6호
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• pp.366-374
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• 2021

Objective: This study investigated the impact of a single piezocision in the maxillary alveolar process on the speed of tooth movement. The null hypothesis was that the speed of tooth movement will be equal with and without piezocision. Methods: All maxillary molars on one side were moved against the combined incisors in 10 ten-week-old male Wistar rats. Under general anesthesia, a force of 25 cN was applied on either side using a Sentalloy closed coil spring. After placing the orthodontic appliance, vertical corticision was performed using a piezotome under local anesthesia, 2 mm mesial from the mesial root of the first molar on a randomly selected side; the other side served as the control. At the beginning of the treatment, and 2 and 4 weeks later, skull micro-computed tomography was performed. After image reconstruction, the distance between the mesial root of the first molar and the incisive canal, and the length of the mesial root of the first maxillary molar were measured. Moreover, the root resorption score was determined as described by Lu et al. Results: Significantly higher speed of tooth movement was observed on the corticision side; thus, the null hypothesis was rejected. The loss of root length and root resorption score were significantly more pronounced after piezocision than before. A strong correlation was observed between the speed of tooth movement and root resorption on the surgical side, but the control side only showed a weak correlation. Conclusions: Piezocision accelerates orthodontic tooth movement and causes increased root resorption.

• 한국공작기계학회논문집
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• 제10권4호
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• pp.97-103
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• 2001

The study on the high-speed machine tool is very important for the improvement of productivity since it can shortens cutting and non-cutting time. Especially, high speed of feed drive system is the major research field. In the industries of the advanced countries, the feed drive systems at the speed of 60 m/min have been already developed based on the high lead ball screws. In this study, a high speed feed drive system at the speed of 60 m/ min has been developed, and its movements characteris-tics are investigated. As the movement characteristics, positioning accuracy, angular accuracy, straightness and micro step-response are measured. Thermal characteristics of the system is also discussed. For measuring the movement characteris-tics, a laser interferometer, a memory-based Hi-coder and a cooling device are used. The experimental results confirm that the movement characteristics and the thermal behavior of the system are satisfactory in the aspect of accuracy and stability.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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• pp.304-309
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• 1986

This paper is about the Inverse Jacobian for the TOP-1 robot. The robot Jacobian is used for the movement in accordance with differental changes. A Matrix and Homogeneous Transformation Matrix, Differential Motion Vector D are applied to Jacobian equation for the movement of the robot in accordance with the minut changes. The solution of Jacobian equation is acquired and applied for the subtle movement of each arms of the robot. The interface with APPLE-II Micro-computer is searched out too. The Software and the interface resulted from this paper are considered to be higly useful in the accurate control on the robot when they are linked with dynamics of robot.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2003년도 추계학술발표대회 개요집
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• pp.159-161
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• 2003

Electrode movement signal has been widely used in resistance spot welding system This study is to compare accelerometer signal with gap sensor signal in servo gun system. This study propose that accelerometer output signal is a useful technique of quality monitoring in resistance welding processes.