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An internal and marginal fit between prosthesis and abutment is an important factor of the durability of dental prosthesis. In this paper, we have proposed the use of swept-source optical coherence tomography (OCT) as a novel application for non-ionized and high-resolution measurements of internal and marginal discrepancies at anatomically critical four points, such as occlusal, angle, axial, and margin during prosthesis attachment. A tooth model was fabricated by a 3D printing technique, and the dental prosthesis was designed using dental CAD software. The cross-sectional images along with intensity peak profile analysis of the sample were acquired using the OCT system for measurements of fit. The demonstrated qualitative and quantitative evaluations can be well-utilized for assessment of the internal and marginal fit of dental prosthesis.

This communication presents the design, fabrication, and measurement of transparent antennas with metal mesh (MM) for wireless transparent applications such as smart windows, transparent mobile devices, and transparent Internet of Things. The MM was proposed as a transparent electrode with high conductivity in electrical performance, with proper transparency in optical performance, and low fabrication cost compared to a traditional transparent thin film electrode. To analyze the performance of a transparent antenna fabricated by MM, the antennas were designed to operate in the 2.4–2.5 GHz WLAN band (802.11b). The conductive metal of transparent MM patch antennas was designed using a square lattice structure and was fabricated using wired MM with copper wire (0.2–0.5 mm). In addition, micro-MM film consisting of thin copper wire ( $20~\mu \text{m}$ ) was used to fabricate transparent patch antennas. The realized gain, efficiency, front-to-back ratio, and radiation patterns of the transparent MM patch antennas are discussed for various combinations of radiator and ground planes. Overall, the transparent MM patch antennas offer optical transparency, maintain sufficient performance, and could possibly be used in wireless transparent applications.

본 논문은 향후 투명 디스플레이, 스마트글래스(smart glass) 등의 그 활용도가 증가 추세에 있는 투명전극과 관련된 논문이며, 본 논문에서는 투명 안테나 등의 투명 고주파 수동소자 설계 시, 투명 디스플레이 등에 가장 많이 사용되고 있는 ITO(Indium-Tin-Oxide)을 이용한 박막형(thin film type) 투명전극의 낮은 전기...

In this study, magnetic resonant wireless power transfer (MR-WPT) system with a reconfigurable resonator using RF switches (PIN diodes) was studied to improve and optimise the transfer efficiency (TE) in a limited three-dimensional (3D) zone for laptop applications. Generally, the TE of the MR-WPT system is decreased by a 3D spatial variation (distance and location) in between the transmitter (Tx) source and the receiver (Rx) load . To improve and optimise the TE for this spatial variation, the authors utilised RF switches in a planar arrayed coils in the Rx. The TE was optimised by the status of the coil resonator (modes 1-6, open, and short) in the Rx. The average TE of the optimal mode increased >5% comparing with that of a certain mode in the whole range of the spatial variation ( x , y , z directions; 80 × 80 × 40 cm 3 ). In addition, they analytically and experimentally demonstrated the TE optimisation by the practical laptop model with the proposed MR-WPT system installed into a desk ( yz -plane) and the wall ( z -direction). Through this research, the proposed reconfigurable resonator with RF switches was shown to be possible for use as a reconfigurable efficiency optimiser in the MR-WPT system.

A magnetic resonance wireless power transfer (MR-WPT) system with a reconfigurable planar receiver (Rx) to optimize transfer efficiency (TE) for laptop application has been investigated. The proposed MR-WPT system consists of a general four-coil system: a source coil and a transmitter Tx) coil in a Tx part and an Rx coil and a load coil in an Rx part. To enable performance comparison, the Rx coil uses either a rectangular loop resonator or a slit ground resonator (SGR) and both resonators are connected with a p-i-n diode to reconfigure and optimize the MR-WPT system’s TE along the transfer distance between the Tx and Rx parts. Mobile devices, including laptops, need a ground plane for practical use; therefore, the Rx coil is replaced by only an SGR, which operates as both a resonator and a ground. This letter, experimentally and theoretically proves that a reconfigurable MR-WPT system with an SGR has sufficient efficiency without the ferrite sheet typically used in practical MR-WPT applications.

Numerous studies have previously evaluated the marginal and internal fit of fixed prostheses, however, few reports have performed an objective comparison of the various methods used for their assessment. The purpose of this study was to compare five marginal and internal fit assessment methods for fixed prostheses. A specially designed sample was used to measure the marginal and internal fit of the prosthesis according to the cross-sectional method (CSM), silicone replica technique (SRT), triple scan method (TSM), micro-computed tomography (MCT), and optical coherence tomography (OCT). The five methods showed significant differences in the four regions that were assessed (p &lt, 0.001). The marginal, axial, angle, and occlusal regions showed low mean values: CSM (23.2 &micro, m), TSM (56.3 &micro, m), MCT (84.3 &micro, m), and MCT (102.6 &micro, m), respectively. The marginal fit for each method was in the range of 23.2&ndash, 83.4 &micro, m and internal fit (axial, angle, and occlusal) ranged from 44.8&ndash, 95.9 &micro, m, 84.3&ndash, 128.6 &micro, m, and 102.6&ndash, 140.5 &micro, m, respectively. The marginal and internal fit showed significant differences depending on the method. Even if the assessment values of the marginal and internal fit are found to be in the allowable clinical range, the differences in the values according to the method should be considered.

This study presents the design and analysis of a magnetic resonant coupling wireless power transfer (MR-WPT) system that employs planar textile resonators. To reduce the size of the system for wearable applications, the transmitter and receiver are designed and fabricated on a flat plane of fabric. A proposed symmetric four-resonator MR-WPT system is used for verifying the electromagnetic property of the textile substrates. Two textile substrates: polyester and cotton fibre are investigated to determine their impact on the transfer efficiency. Experiments show that the transfer efficiency is considerably higher with the polyester substrate than with the cotton substrate. In addition, copper tape and silver paste are employed for the resonator fabrication because of their flexibility. The measured results show that the copper tape has a significantly higher transfer efficiency than the silver paste because of its high conductivity. At a transfer distance of 5 cm, the maximum transfer efficiency is 50% with the polyester substrate and the copper tape resonator. Furthermore, the width of the coil-pattern is varied to determine its impact on the resonant frequency and the transfer efficiency of the MR-WPT system. This research confirms the feasibility of using flexible MR-WPT for wearable applications.

This paper aims to design, fabricate, and analyze transparent and flexible monopole antennas for an application in wearable glasses. A multilayer electrode film composed of 100-nm-thick indium–zinc–tin oxide (IZTO)/Ag/IZTO (IAI), a type of transparent conducting oxide electrodes, is selected as the conductors of antennas and ground planes of the wearable glasses. The average transparency of the proposed antennas is measured to be 81.1% in the visible wavelength, and the electrical conductivity of the proposed antennas is measured to be 2 000 000 S/m. The proposed antennas are fabricated with physical vapor deposition process in high vacuum. Moreover, nontransparent antennas made of a 40-nm-thick silver (Ag) thin film are designed and fabricated to compare their performances with the transparent IAI antennas. To reduce the electromagnetic field absorption of the human head, we introduced and analyzed three configurations (types A–C) of monopole antennas having different directions of radiation patterns. The fabricated IAI antennas show the average efficiency of 40% and 4-dBi peak gain at 2.4–2.5 GHz. Furthermore, they have a specific absorption rate lower than 1.6 W/kg, which complies with the Federal Communications Commission standard, when the input power is 15 dBm, which is Google Glass’s.

In this paper, we miniaturized the loop and coil in magnetic resonance wireless power transfer(MR-WPT) system for application to the small mobile device. The proposed disk type double coil resonator was designed to cause resonance at 6.87 MHz. It is composed of thin copper on both-side of acrylic substrate structured 2 mm width, 1 mm pitch and 8 turns. The outer radius of spiral coil pattern is 9 cm. And the proposed loop was made of the copper wire 5 mm diameter of cross-section. The size of loop is 10 cm diameter. For resonance at 6.87 MHz, the capacitor with 3,300 pF was connected in series on the loop. We rearranged the resonators and organized several WPT systems which is rearranged by resonators. The highest transfer efficiency of miniaturized WPT system was 35.67 %. This proposed design of spiral double coil will contribute to make resonator smaller for appling small and thin mobile device.

This paper presents a magnetic resonance wireless power transfer (WPT) system that uses three coils, a planar receiver and operates at 6.78 MHz,. Effective power transfer is ensured by establishing an impedance matching condition for this WPT system. A metamaterial (MTM) array having dimensions of 20 cm Ⅹ 30 cm is also positioned near the load coil to concentrate the magnetic field and enhance the transfer efficiency. The result is a maximal improvement of 27% in the transfer efficiency at a transfer distance of 50 cm. The impact of a ground plane on the transfer efficiency is also examined. By utilizing the MTM array, making slits on the ground plane and increasing the gap between the ground plane and the load coil, it is possible to mitigate this impact. The highest transfer efficiency improvement is about 55% at a distance of 20 cm with the ground plane. A practical laptop model is fabricated to verify the impact of the load coil angle and position on the transfer efficiency. The result shows that the maximum transfer efficiency with the laptop model is 47.58% with the load coil angle of 90 degree.

This letter presents the comparison of performance of planar textile resonators (PTRs) with various forms of conductive patterns. The conductive materials of the conductive pattern included copper sheet and copper wires of three different thicknesses. The PTRs with thin copper wires were found to be flexible and stable for wearable applications. To verify the performance of PTRs in MR-WPT, a symmetrical four-coil system was measured. This study considered the normal and standard condition of PTRs without any forms of modification in physical. The results showed that thin copper wires, especially of 1.0 mm thickness, had the highest transfer efficiency of 75.66% because the thickness of copper sheet is not sufficient for skin depth and the current was over ampacity of copper sheet.

In this letter, the effect of the human body in a magnetic resonance wireless power transfer (MR-WPT) system for wearable and implantable devices is studied. To implement the experiment, muscle-mimicking liquid is configured with parameters similar to those of the human body. The transmitter part is located outside the human body (in the air), and the receiver part is implanted in the liquid. The proposed 3-coil MR-WPT system, which operates at 6.78 MHz shows effectively higher transfer efficiencies compared with a 4-coil MR-WPT system at near transfer distance which is the predicted position for a pacemaker. The results indicate that the proposed system with optimized receiver using air-pocket has potential applications in off/in-body devices that benefit from remote energy harvesting, especially at near distances such as pacemakers.

In observing the stereoscopic display at the viewing distance of 1 m, the amount of the perceived depth was determined by the positions of the crossing point that the viewing direction of two eyes intersect. The positions of the crossing points of stereoscopic stimuli were controlled, and the accommodation was measured by the autorefractometer for the seven participants. Accommodation was also measured when viewing the real film chart which was placed at the same position as these crossing points. The accommodation change when viewing the stereoscopic display was measured to be noticeable only when the crossing point was quite near the participant, but this change was still much smaller compared with the accommodation change when viewing the real film chart. This change in accommodation implies the possible occurrence of fatigue related to the accommodation–convergence conflict, while the constant accommodation within the range of DOF implies no conflict between the accommodation and convergence. This measurement scheme may be used to define the range of DOF where the accommodation remains little changed, and thus define the depth of the 3D object at which no accommodation–convergence conflict occurs, for a given stereoscopic display.

Purpose: This study compared the quantity of phoria for distance by new method with that by existing methods. Methods: For this study, it was selected to two existing phoria measurements, von Graefe and Maddox rod. And new method named "3D polarizing phoria measurement" was designed to measure the quantity of phoria using polarizing glasses and 3D display. Unlike existing measurement using polarized lens, newly considered method measured the quantity of phoria in condition removed perfect binocular fusion using field stop on apparatus and polarized lens. For using new method for distance, it was developed a phoria test chart. It supports three kinds of phoria measurements. Subjects were 12 (male 6, female 6). They had three phoria tests (1 sets) including new method. It was considered the effect of experimental order, so we tested all cases about experimental order. The number of cases was 6 sets, and the sample size in this experiment was 72 sets. For removing binocular fusion, lighting of the laboratory that was below 10 lx and the background color of phoria test chart was dark, RGB=(20, 20, 20). Results: Subjects were sorted into three groups. Samples with exophoria and orthophoria were 30 sets each, and those with esophoria were 12 sets. The quantity of phoria measured three tests differ from each other like "newmethod

In this study, we suggested optimal design of in-body resonator by capacitance and air gap. We proposed magnetic resonance wireless power transfer (MR-WPT) system consisted of three resonators and was therefore called a three-resonator MR-WPT system. The proposed power transfer occurs between a wearable transmitter in the air and an implantable receiver in the fabricated muscle-mimicking liquid. According to the analysis of measurement results, the muscle-mimicking leads blocking on the H-field of MR-WPT system. This phenomenon has an affect the decreasing transfer efficiency that could be explained by the change in resonant frequency of the receiver resonator due to the impact of the dielectric constant and the conductivity of the MML liquid. To solve this problem, we suggested utilizing either an optimal capacitor or an air pocket to prevent the MML liquid from having this effect. These solutions improved the transfer efficiency of the MR-WPT system.

Wireless power transfer (WPT) system has been studied and four-coil WPT is the standard form in indirect-fed magnetic resonance WPT (MR-WPT). In this research, we fabricated small copper coil and transparent electrode coil. The electrode was deposed IZTO/Ag/IZTO as a multilayer film structure. Load loop and source loop were optimized using capacitors. The efficiency was measured in distance from 1 cm to 5 cm. The optimized efficiency of the MR-WPT with capacitance was 81% using a copper coil and 57% using a transparent coil (IZTO/Ag/IZTO) at 1 cm.

PURPOSE This study aims to evaluate the loosening torque on the implant fixture, and to assess the accuracy of difference electronic torque drivers. MATERIALS AND METHODS Three electronic torque drivers were used to measure the loosening torque on the implant system (AnyOne; MegaGen). The implant fixtures were divided among the 3 electronic torque driver types (W&H, SAESHIN, and NSK group) and 9 for each group. The screws were fastened at the implant fixture by three electronic torque drivers using the tightening torques recommended by the manufacturers of the drivers. After 10 minutes, the screws were again fastened at the implant fixture with equal torque. Then, the loosening torques were measured with an MGT12 torque gauge (MARK-10, Inc.). This measurement procedure was repeated 10 times under loosening torques of 15 Ncm, 25 Ncm, and 35 Ncm. In the statistical analysis, all values of loosening torque were analyzed with the one-way ANOVA and Kruskal-Wallis test (α=.05) for comparative evaluation. RESULTS There were significant inter-group differences at loosening torques of 15 Ncm and 25 Ncm (P.05). The SAESHIN driver showed the closest loosening torque at 35 Ncm. CONCLUSION The most accurate loosening torques were SAESHIN at 35 Ncm, and NSK at 15 Ncm and 25 Ncm. Since the loosening torque may vary depending on the tightening torques and electronic torque drivers, periodic calibration of the electronic torque driver is recommended.

In this study, a wireless power transfer (WPT) system including three coils and working at 6.78 MHz is investigated. By employing a 2 × 3 metamaterial (MTM) array, the efficiency of the proposed WPT system is significantly enhanced. Experiments show that with the MTM array, a maximum efficiency improvement of 27 % is achieved at transfer distance of 35 cm. The impact of ground plane on the transfer efficiency is also studied. Several methods to reduce this impact are discussed and measured.

We investigate the indirect-fed magnetic resonant wireless power transfer system by rearranging the loops and coils used in the conventional wireless charging system for mobile devices. Three rearranged configurations (Out-Out, Out-In, In-In) have been considered and experimentally investigated by using hollow pipe copper loops (coils) and wire copper loops (coils). The power transfer efficiencies for the three configurations were similar. The highest measured efficiency of 82.5% was achieved at 35 cm distance between the Tx and Rx coils. We also investigated the practical application of the mobile device (note-pc), by rotating load loops and the Rx coil vertically, L-shape. The highest efficiency of the L-shape system, was 64.5 % at 45 cm distance between the Tx and Rx coils.