- 标题
- 摘要
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- 实验方案
- 产品
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Comparison of accuracies of an intraoral spectrophotometer and conventional visual method for shade matching using two shade guide systems
摘要： Background and Objectives: This in vitro study compared the shade matching abilities of an intraoral spectrophotometer and the conventional visual method using two shade guides. The results of previous investigations between color perceived by human observers and color assessed by instruments have been inconclusive. The objectives were to determine accuracies and interrater agreement of both methods and effectiveness of two shade guides with either method. Methods: In the visual method, 10 examiners with normal color vision matched target control shade tabs taken from the two shade guides (VITAPAN Classical? and VITAPAN 3D Master?) with other full sets of the respective shade guides. Each tab was matched 3 times to determine repeatability of visual examiners. The spectrophotometric shade matching was performed by two independent examiners using an intraoral spectrophotometer (VITA Easyshade?) with five repetitions for each tab. Results: Results revealed that visual method had greater accuracy than the spectrophotometer. The spectrophotometer; however, exhibited significantly better interrater agreement as compared to the visual method. While VITAPAN Classical shade guide was more accurate with the spectrophotometer, VITAPAN 3D Master shade guide proved better with visual method. Conclusion: This in vitro study clearly delineates the advantages and limitations of both methods. There were significant differences between the methods with the visual method producing more accurate results than the spectrophotometric method. The spectrophotometer showed far better interrater agreement scores irrespective of the shade guide used. Even though visual shade matching is subjective, it is not inferior and should not be underrated. Judicious combination of both techniques is imperative to attain a successful and esthetic outcome.
关键词： spectrophotometer,shade guide,Accuracy,dental shade matching,repeatability
更新于2025-09-19 17:15:36
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[IEEE 2018 19th International Conference on Electronic Packaging Technology (ICEPT) - Shanghai (2018.8.8-2018.8.11)] 2018 19th International Conference on Electronic Packaging Technology (ICEPT) - Research and Introduction of the Process Flow of Full-automatic Wafer Level Flip Chip Machine
摘要： At present, there are many kinds of process technologies that can be used in the field of microelectronic packaging. Current mainstream technologies mainly include gate array package (BGA), flip chip technology (FC), chip scale package (CSP), system-in-package (SIP), and three-dimensional (3D) package. After years of development, flip chip technology has gradually developed into a mainstream technology in the field of electronic packaging. The biggest feature of the flip chip technology is that the interconnect line is short. Compared with other packaging methods, it has the characteristics of small area and high density, and the overall performance is better than other methods. In the context of flip chip technology, the development of its corresponding process equipment is particularly important for the improvement of the industry's capacity. However, at present in the Chinese domestic market, there are very few institutions and companies that conduct research on domestic wafer-level flip-chip equipment, and they have not achieved mass production. The device we developed is a non-lead bonded wafer level flip-chip soldering machine for IC semiconductor material packages. It uses heating, pressing, and ultrasonic energy modules to form electrical connections between the chip electrodes and the substrate. Solid-state soldering and packaging processes for IC integrated circuits and other products. It is also compatible with flip-chip soldering of 4-inch wafer substrates or ceramic substrates, 6-inch, 8-inch, and 12-inch wafer substrates. It contains four major systems: mechanical systems, electronic control systems, image recognition systems, and software systems. The mechanical system consists of a wafer ring loading and unloading module, a wafer table module, a flip chip module, a die bonding head module, a dispensing module, an ultrasonic and heating and pressing module, a wafer substrate table module and a wafer substrate automatic loading and unloading module. Each module works in coordination with each other. After the chip goes through the flip chip and the die bonder module from the wafer table, it is connected with the substrate after the ball bonding by the glue and other fillers. And is supplemented by hot pressing or ultrasonic waves is supplemented to strengthen connection performance. After the equipment is debugged, the time of the cycle can be used to measure the time period of the whole flip-chip solid crystal up to 1.8s. The results were observed under microscope, the positioning accuracy of flip-chip welding can reach 10μm. The appearance of this device will not only realize the industrialization of the flip-chip interconnection technology of the IC semiconductor industry, but its successful development is of great significance to the domestic development and manufacturing of semiconductor packaging equipment.
关键词： Flip chip,Microelectronics package,Positioning accuracy,Wafer level equipment
更新于2025-09-19 17:15:36
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[IEEE 2018 IEEE International Electron Devices Meeting (IEDM) - San Francisco, CA, USA (2018.12.1-2018.12.5)] 2018 IEEE International Electron Devices Meeting (IEDM) - A CMOS Proximity Capacitance Image Sensor with <tex>$16\mu \mathrm{m}$</tex> Pixel Pitch, 0.1aF Detection Accuracy and 60 Frames Per Second
摘要： A 16μm pitch 256×256 frames per second CMOS proximity capacitance image sensor fabricated by a 0.18μm CMOS process technology is presented. By the introduction of noise canceling operation, both fixed pattern noise (FPN) and kTC noise are significantly reduced, resulting in the 0.1aF (10-19F) detection accuracy. Proximity capacitance imaging results using the developed sensor are also demonstrated.
关键词： detection accuracy,CMOS,noise canceling,kTC noise,60 fps,proximity capacitance image sensor,0.1aF,FPN
更新于2025-09-19 17:15:36
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[IEEE 2018 IEEE International Symposium on Medical Measurements and Applications (MeMeA) - Rome, Italy (2018.6.11-2018.6.13)] 2018 IEEE International Symposium on Medical Measurements and Applications (MeMeA) - Optoelectronic-system based characterization of a robotic device for evaluation and rehabilitation of balance disorders
摘要： The paper describes an experimental method for the estimation of the orientation and moment-measurement accuracy of the robot Roto.Bit3D, designed for the evaluation and rehabilitation of balance disorders in adults. The method is based on the use of an optoelectronic system and a calibrated reference mass. The results allowed to estimate a maximum difference between measurements, performed by motion capture and robot, of about ±0.1° and ±1 Nm, for orientation and moment, respectively. Results are in agreement with the previous version of the robot, designed for pediatrics, already characterized with a different experimental method.
关键词： balance control,motion capture,robot therapy,accuracy
更新于2025-09-19 17:15:36
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Dimensional accuracy of cone beam CT with varying angulation of the jaw to the X-ray beam
摘要： Objectives: CBCT machines do not always allow for patients to be scanned in the ideal position for image acquisition. This study aimed to investigate the influence of the position/angulation of the mandible relative to the x-ray beam of a CBCT machine. Methods: Five sequential CBCT scans were captured of a human mandible at each angulation. The 0° occlusal plane was captured as the reference followed by 10°, 20°, 30° and 40° using a coronal and sagittal positioning. Inspection software utilized a best fit alignment to automatically calculate the three-dimensional variation at 15 standardized points of interest. Results: Statistically significant differences were found between the dimensional accuracy of CBCT scans taken at 10° (0.0263mm) of coronal angulation, as well as those taken at 20° (-0.0173mm) and 30° (0.0352mm) of sagittal angulations (P <0.001, 0.016, and <0.001, respectively). The largest deviations in accuracy included an overall maximum deviation of 0.490mm. Conclusion: The position of the mandible with respect to the x-ray beam has a clinically insignificant effect on dimensional accuracy, up to the maximum angle of 40° assessed.
关键词： Imaging,Three-Dimensional,Dimensional Measurement Accuracy,Cone-Beam Computed Tomography
更新于2025-09-19 17:15:36
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Assessment of Segmentation Parameters for Object-Based Land Cover Classification Using Color-Infrared Imagery
摘要： Using object-based image analysis (OBIA) techniques for land use-land cover classification (LULC) has become an area of interest due to the availability of high-resolution data and segmentation methods. Multi-resolution segmentation in particular, statistically seen as the most used algorithm, is able to produce non-identical segmentations depending on the required parameters. The total effect of segmentation parameters on the classification accuracy of high-resolution imagery is still an open question, though some studies were implemented to define the optimum segmentation parameters. However, recent studies have not properly considered the parameters and their consequences on LULC accuracy. The main objective of this study is to assess OBIA segmentation and classification accuracy according to the segmentation parameters using different overlap ratios during image object sampling for a predetermined scale. With this aim, we analyzed and compared (a) high-resolution color-infrared aerial images of a newly-developed urban area including different land use types; (b) combinations of multi-resolution segmentation with different shape, color, compactness, bands, and band-weights; and (c) accuracies of classifications based on varied segmentations. The results of various parameters in the study showed an explicit correlation between segmentation accuracies and classification accuracies. The effect of changes in segmentation parameters using different sample selection methods for five main LULC types was studied. Specifically, moderate shape and compactness values provided more consistency than lower and higher values; also, band weighting demonstrated substantial results due to the chosen bands. Differences in the variable importance of the classifications and changes in LULC maps were also explained.
关键词： accuracy,infrared,segmentation,object-based classification,orthophoto,high resolution imagery,land cover
更新于2025-09-19 17:15:36
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Investigation of Production Limits in Manufacturing Microstructured Surfaces Using Micro Coining
摘要： The application of microstructured surfaces is one possible method to reduce friction in lubricated contacts between components with relative movement. Due to this, the energy efficiency and the occurring wear during the operating time of the final products could be decreased. To manufacture structured surfaces economically, a micro coining process was analyzed within this study. This process offers the potential for integration into the established manufacturing processes of different final products, such as tappets used in a valve train. Thus, large-scale production is enabled. To detect the manufacturing limits of the micro coining process, the manufacturing of the coining tools as well as the coining process needs to be investigated. Within this study, the achievable accuracy and the failure of cuboid and cylindrical microstructure elements with selected dimensions were analyzed. For both types of microstructures, the minimal lateral dimensions were detected. Besides the achievable accuracy, correlations between different geometrical dimensions of the micro elements are presented. Additionally, the aspect ratio is detected as the main cause of failure for the micro coining process. In general, the suitability of a coining process for manufacturing microstructured surfaces is proven.
关键词： geometrical accuracy,microstructures,tribology
更新于2025-09-19 17:15:36
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Deep Convolutional Neural Network for HEp-2 Fluorescence Intensity Classification
摘要： Indirect ImmunoFluorescence (IIF) assays are recommended as the gold standard method for detection of antinuclear antibodies (ANAs), which are of considerable importance in the diagnosis of autoimmune diseases. Fluorescence intensity analysis is very often complex, and depending on the capabilities of the operator, the association with incorrect classes is statistically easy. In this paper, we present a Convolutional Neural Network (CNN) system to classify positive/negative fluorescence intensity of HEp-2 IIF images, which is important for autoimmune diseases diagnosis. The method uses the best known pre-trained CNNs to extract features and a support vector machine (SVM) classifier for the final association to the positive or negative classes. This system has been developed and the classifier was trained on a database implemented by the AIDA (AutoImmunité, Diagnostic Assisté par ordinateur) project. The method proposed here has been tested on a public part of the same database, consisting of 2080 IIF images. The performance analysis showed an accuracy of fluorescent intensity around 93%. The results have been evaluated by comparing them with some of the most representative state-of-the-art works, demonstrating the quality of the system in the intensity classification of HEp-2 images.
关键词： autoimmune diseases,accuracy,SVM,receiver operating characteristic (ROC) curve,Convolutional Neural Network (CNN),IIF images
更新于2025-09-19 17:15:36
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The Analysis of Fiber and CO <sub/>2</sub> Laser Cutting Accuracy
摘要： The aim of the conducted research was to compare the functional properties and the cutting accuracy of items produced using Fiber lasers in comparison with CO2 lasers. The object of 6 mm thick sheet plates made of S235JR steel cut with the two different laser types were analyzed. The tests covered dimensional accuracy (in accordance with the PN EN 22768-fH standard) and the surface after cutting (in accordance with the PN-EN ISO 9013: 2017-04). The results of the analysis have demonstrated that for the same welding linear energy, more accurate cutting surface is obtained using Fiber laser cutting.
关键词： CO2 lasers,Fiber lasers,S235JR steel,surface quality,cutting accuracy,dimensional accuracy
更新于2025-09-19 17:13:59
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[IEEE 2019 9th International Electric Drives Production Conference (EDPC) - Esslingen, Germany (2019.12.3-2019.12.4)] 2019 9th International Electric Drives Production Conference (EDPC) - Fault Classification and Correction based on Convolutional Neural Networks exemplified by laser welding of hairpin windings
摘要： Using parallel associative reduction, iterative re?nement, and conservative early termination detection, we show how to use tree-reduce parallelism to compute correctly rounded ?oating-point sums in Oelog NT depth. Our parallel solution shows how we can continue to exploit the scaling in transistor count to accelerate ?oating-point performance even when clock rates remain ?at. Empirical evidence suggests our iterative algorithm only requires two tree-reduce passes to converge to the accurate sum in virtually all cases. Furthermore, we develop the hardware implementation of two residue-preserving IEEE-754 double-precision ?oating-point adders on a Virtex 6 FPGA that run at the same 250 MHz pipeline speed as a standard adder. One adder creates the residue by truncation, requires only 22 percent more area than the standard adder, and allows us to support directed-rounding modes and to lower the cost of round-to-nearest modes. The second adder creates the residue while directly producing a round-to-nearest sum at 48 percent more area than a standard adder.
关键词： accuracy,accumulation,IEEE-754,Floating-point arithmetic,parallel,FPGA,correct rounding
更新于2025-09-19 17:13:59