scholarly journals Manufacturing a Plotter Printer with Computer Numerical Control Based Pen Ink Using CoreXY Mechanisms

2021 ◽  
Vol 5 (2) ◽  
pp. 370
Author(s):  
Veshea Falerie Goszal ◽  
Hilal Hudan Nuha ◽  
Maman Abdurohman
Keyword(s):  
Motion Control ◽  
High Precision ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Precision Measurements ◽  
Control Technique ◽  
High Quality ◽  
The Mean

In the process of printing images, a high-quality plotter printer is required to obtain better printed images. This causes the costs incurred to purchase a plotter printer become even higher along with the quality of the printout. In addition, the use of original plotter printer ink is significantly more expensive than that of the non-original ink. Therefore, this paper proposes a pen based computer plotter printer design using the CoreXY framework. This framework is based on a 2D in-axis motion control technique using a single continuous belt for both axes. To evaluate the performance of the proposed design, the level precision for vector and raster modes are measured using the Mean Absolute Percentage (MAPE). Based on the results of precision measurements, it was found that the printer prototype designed to produce high-precision images with affordable pen ink costs and can process digital instructions from a computer using Computer Numerical Control (CNC).

Synergistic real-time compensation of tracking and contouring errors for precise parametric curved contour following systems

2017 ◽  
Vol 232 (19) ◽  
pp. 3367-3383 ◽  
Author(s):  
De-Ning Song ◽  
Jian-Wei Ma ◽  
Zhen-Yuan Jia ◽  
Feng-Ze Qin ◽  
Xiao-Xuan Zhao
Keyword(s):  
Real Time ◽  
High Precision ◽  
Tracking Error ◽  
Estimation Algorithm ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
System Structure ◽  
Parametric Curve ◽  
Contouring Error ◽  
Contour Following

The tracking and contouring errors are inevitable in real computer numerical control contour following because of the reasons such as servo delay and dynamics mismatch. In order to improve the motion accuracy, this paper proposes a synergistic real-time compensation method of tracking and contouring errors for precise parametric curve following of the computer numerical control systems. The tracking error for each individual axis is first compensated, by using the feed-drive models with the consideration of model uncertainties, to enhance the tracking performances of all axes. Further, the contouring error is estimated and compensated to improve the contour accuracy directly, where a high-precision contouring-error estimation algorithm, based on spatial circular approximation of the desired contour neighboring the actual motion position, is presented. Considering that the system structure is coupled after compensation, the stability of the coupled system is analyzed for design of the synergistic compensator. Innovative contributions of this study are that not only the contouring-error can be estimated with a high precision in real time, but also the tracking and contouring performances can be simultaneously improved although there exist modeling errors and disturbances. Simulation and experimental tests demonstrate the effectiveness and advantages of the proposed method.

Developing a Research Database of Primary Aldosteronism: Rationale and Baseline Characteristics

2021 ◽  
Author(s):  
Wen Wang ◽  
Yuanmei Li ◽  
Qianrui Li ◽  
Tingting Zhang ◽  
Wei Wang ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Primary Aldosteronism ◽  
Prospective Cohort ◽  
Research Database ◽  
High Quality ◽  
Plasma Aldosterone Concentration ◽  
Confirmatory Testing ◽  
The Mean ◽  
High Level

Abstract BackgroundManagement of primary aldosteronism (PA) has become a research hotspot in the field of endocrinology. To obtain reliable research evidence, it is necessary to establish a high-quality PA research database. MethodsThe establishment of PA research database involved two steps. Firstly, patients with confirmation of PA diagnosis between 1 Jan 2009 to 31 Aug 2019 at West China Hospital were identified and data were extracted. Secondly, patients with confirmatory testing for PA will be enrolled into a prospective cohort. Data will be prospectively collected based on the case report forms since 1 Sep 2019. We evaluated the quality of research database through assessment of quality of key variables.ResultsTotally, 862 patients diagnosed as PA were identified, of which 507 patients who had positive confirmatory testing for PA were included into the retrospective database. Among 862 patients diagnosed as PA, the mean systolic blood pressure (SBP) was 156.1 mmHg, mean diastolic blood pressure (DBP) was 97.2 mmHg. Among included patients, the mean serum potassium level was 2.85 mmol/L, and the mean plasma aldosterone concentration (PAC) was 28.1 ng/dL. The characteristics patients with positive confirmatory testing for PA were similar. Validation of data extracting and linking showed the accuracy were 100%. Evaluation of missing data showed that the completeness of BMI (95.9%), SBP (99.4%) and DBP (99.4%) were high. ConclusionThrough integrating retrospective and prospective cohort of PA, a research database of PA with high quality and comprehensive data can be established. We anticipate that the research database will provide a high level of feasibility for management of PA in China.

Qualitative evaluation of paediatric surgical otolaryngology content on YouTube

2020 ◽  
Vol 134 (2) ◽  
pp. 135-137 ◽  
Author(s):  
B Ward ◽  
R Bavier ◽  
C Warren ◽  
J Yan ◽  
B Paskhover
Keyword(s):  
Health Information ◽  
Qualitative Evaluation ◽  
Video Content ◽  
Medical Decisions ◽  
High Quality ◽  
Youtube Videos ◽  
The Mean

AbstractObjectiveThis study evaluated the quality of YouTube content focusing on common paediatric otolaryngology procedures, as this content can influence the opinions and medical decisions of patients.MethodsA total of 120 YouTube videos were compiled to review using the terms ‘adenoid removal’, ‘adenoidectomy’, ‘ear tubes’, ‘tympanostomy’, ‘tonsil removal’ and ‘tonsillectomy’. The Discern criteria was used to rate the quality of health information presented in each video.ResultsThe mean bias Discern score was 3.18 and the mean overall Discern score was 2.39. Videos including US board certified physicians were rated significantly higher (p < 0.001) than videos without (bias Discern score = 3.00 vs 2.38; overall Discern score = 3.79 vs 1.55). The videos had been viewed a total of 176 769 549 times.ConclusionUnbiased, high quality videos on YouTube are lacking. As patients may rely on this information when making medical decisions, it is important that practitioners continually evaluate and improve this video content. Otolaryngologists should be prepared to discuss YouTube content with patients.

scholarly journals A genetic algorithm-based parameter-tuning algorithm for multi-dimensional motion control of a computer numerical control machine tool

2002 ◽  
Vol 216 (3) ◽  
pp. 429-438 ◽  
Author(s):  
L-Y Kuo ◽  
J-Y Yen
Keyword(s):  
Genetic Algorithm ◽  
Motion Control ◽  
Traditional Approach ◽  
Parameter Tuning ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Cnc Machine ◽  
Control Machine Tool ◽  
Machine Centre ◽  
Cross Axis

This paper addresses an automatic parameter-tuning algorithm for the multi-axis motion control of a computer numerical control (CNC) machine centre. The traditional approach to tune the control parameters in the multi-axis machines is to tune each axis independently. Some high-end-precision machines offer cross-axis motion parameters for impedance compensation but this is usually not satisfactory for practical purpose. Because each axis on the machine centre contributes to more than one working plane, obtaining the optimal performance for motions involving more than one plane often results in axis coupling. This paper introduces a systematic method to tune the servo parameters for multi-axis motion control. The tuning algorithm is based upon an intelligent genetic algorithm (GA) and the parameters are tuned for each work plane. The method optimized the multi-axis motion performance. A modified GA is also proposed to solve the convergence problem induced by a large number of parameters in multi-axis motion tuning.

scholarly journals Dietary and herbal supplements for weight loss: assessing the quality of patient information online

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Jeremy Y. Ng ◽  
Saad Ahmed ◽  
Catherine Jiayi Zhang
Keyword(s):  
Weight Loss ◽  
Health Information ◽  
Healthcare Providers ◽  
The United States ◽  
Consumer Health Information ◽  
Consumer Health ◽  
High Quality ◽  
The Mean ◽  
The Impact

Abstract Background Given the high prevalence of dietary and herbal supplement (DHS) use in tandem with the growing ease of internet access, patients commonly search online for consumer health information about these products. One common reason for DHSs use includes weight loss. Healthcare providers need to be aware of the quality of online information about DHSs for weight loss so they can adequately counsel their patients and provide them with guidance surrounding the identification of high-quality information resources. This study aimed to assess the quality of online DHSs consumer health information for weight loss that a “typical” patient might access online. Methods Six search terms were used to generate the first 20 websites on the Google search engine in four countries: Australia, Canada, the United Kingdom, and the United States (n = 480 websites). After applying exclusion criteria, eligible websites were quality assessed using the DISCERN instrument. This tool is comprised of 16 questions, each evaluated on a 5-point scale. The averages and standard deviations for each DISCERN instrument item, in addition to overall summed scores between 15 and 75 were calculated. Results Across 87 eligible websites, the mean summed score was 44.80 (SD = 11.53), while the mean overall DISCERN score of each website was 2.72 (SD = 0.99). In general, websites detailed and achieved their specified aims and described treatment benefits. However, most websites failed to describe the impact of treatment on overall quality of life and the impact of a no treatment option. The highest-scoring websites were largely government or health portal websites, while the lowest-scoring websites were largely commercial in nature. Conclusion High variability in DISCERN instrument scores was found across all websites assessed. Healthcare providers should be aware of the fact that their patients may be accessing misinformation online surrounding the use of DHSs for weight loss. Therefore, it is important for healthcare providers to ensure that they are providing their patients with guidance on how to identify high-quality resources online, in order that safe, effective, and evidence-based decisions are made surrounding the use of DHSs for weight loss.

Technique to Produce Segment-Color Yarn with Ring Frame

2011 ◽  
Vol 332-334 ◽  
pp. 72-76
Author(s):  
Jun Lian ◽  
Bo Jun Xu ◽  
Chun Ping Xie
Keyword(s):  
Basic Principle ◽  
Main Parameter ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
High Quality ◽  
Ring Frame ◽  
New Type

segment-color yarn is a new type yarn. It can be spin by ring frame with computer numerical control. The basic principle of spinning segment-color yarn was developed in this paper. The main parameter of segment-color yarn were discussed. This can help produce high quality segment-color yarn.

scholarly journals Accuracy of Implant Surgical Guides Fabricated Using Computer Numerical Control Milling for Edentulous Jaws: A Pilot Clinical Trial

2020 ◽  
Author(s):  
Jinyou Chai ◽  
Xiaoqian Liu ◽  
Ramona Schweyen ◽  
Jürgen Setz ◽  
Shaoxia Pan ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Cnc Milling ◽  
Implant Position ◽  
Surgical Guides ◽  
Computer Aided ◽  
Cad Cam ◽  
The Mean ◽  
Edentulous Jaws

Abstract Background To evaluate the accuracy of a computer-aided design and computer-aided manufacturing (CAD-CAM) surgical guide for implant placement in edentulous jaws. Methods Nine patients with twelve edentulous jaws seeking implants were recruited. Radiographic guides with diagnostic templates were fabricated from try-in waxup dentures. Planning software (Organical® Dental Implant, Berlin, Germany) was used to virtually design the implant positions, and the radiographic templates were converted into surgical guides using computer numerical control (CNC) milling. Following the guided implant surgery protocol, forty-four implants were placed into twelve edentulous jaws. Cone-beam computed tomography (CBCT) scans were performed post-operatively for each jaw, and the deviations between the planned and actual implant positions were measured. Results All 44 implants survived, and no severe haematomas, nerve injuries or unexpected sinus perforations occurred. The mean three dimensional linear deviation of implant position between virtual planning and actual placement was 1.53 ± 0.48 mm at the implant neck and 1.58 ± 0.4 mm at the apex. The angular deviation was 3.96 ± 3.05 degrees. The mean deviation between virtual and actual implant position was significantly smaller in the maxilla than in the mandible. No significant differences were found in the deviation of implant position between cases with and without anchor pins. Conclusions The guides fabricated using the CAD-CAM CNC milling technique provided comparable accuracy as those fabricated by Stereolithography. The displacement of the guides on edentulous arch might be the main contributing factor of deviation. Trial registration: Chinese Clinical Trial Registry, ChiCTR-ONC-17014159

Machining, Grinding, and Finishing

2005 ◽  
pp. 89-127
Keyword(s):  
High Precision ◽  
Metal Removal ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Cutting Fluids ◽  
Rough Machining ◽  
Gear Cutting ◽  
Gear Hobbing ◽  
Major Variable ◽  
Gear Manufacture

Abstract Metal removal processes for gear manufacture can be grouped into two general categories: rough machining (or gear cutting) and finishing (or high-precision machining). This chapter discusses the processes involved in machining for bevel and other gears. The chapter describes the type of gear as the major variable and discusses the machining methods best suited to specific conditions. Next, the chapter provides information on gear cutter material and nominal speeds and feeds for gear hobbing. Further, it describes the cutting fluids recommended for gear cutting and presents a comparison of steels for gear cutting. The operating principles of computer numerical control and hobbing machines are also covered. This is followed by sections that discuss the processes involved in grinding, honing, and lapping of gears. Finally, the chapter provides information on the superfinishing of gears.

scholarly journals Yield and Quality of Mung Bean (Vigna radiata (l.) R. Wilczek) Seeds Produced in Poland

2017 ◽  
Vol 74 (2) ◽  
pp. 149 ◽  
Author(s):  
Kamil MISIAK ◽  
Barbara GÓRNA ◽  
Ewelina KRÓL ◽  
Roman HOŁUBOWICZ
Keyword(s):  
Common Bean ◽  
Vigna Radiata ◽  
Mung Bean ◽  
Phaseolus Vulgaris L ◽  
Total Proteins ◽  
High Quality ◽  
Yield And Quality ◽  
The Mean ◽  
Mature Seeds

The aim of the experiment was to do field and laboratory assessments of yield and quality of mung bean (Vigna radiata (L.) R. Wilczek) seeds cultivated in Western Poland. Mean yield of seeds per plant was higher for common bean (Phaseolus vulgaris L.) than for mung one: 13.1 g and 2.58 g, respectively. The mean 1000 mung seeds weight was 50.9 g and their germination – 78 %. Germination capacities of seeds of both beans in the field were similar. Mung beans, compared to common bean, had much smaller seeds, started to bloom later and produced mature seeds later than the latter. Mung bean seeds had more total proteins and Magnesium and Copper than common bean seeds. In Western Poland, production of high quality mung bean seeds was possible.

scholarly journals The Vocabulary Knowledge of Saudi EFL Tertiary Students

2019 ◽  
Vol 12 (5) ◽  
pp. 55
Author(s):  
Sultan Altalhab
Keyword(s):  
Low Frequency ◽  
Vocabulary Knowledge ◽  
Vocabulary Test ◽  
Vocabulary Size ◽  
High Quality ◽  
Authentic Texts ◽  
The Mean ◽  
Basic Level

This study examines the vocabulary knowledge of 120 Saudi tertiary students in order to scrutinise their ability to communicate in English. A vocabulary test constructed by Nation and Beglar (2007) was utilised in the study. The findings revealed that the mean vocabulary size of Saudi EFL tertiary students was roughly 3000 words. Nevertheless, most of the participants achieved low scores in the vocabulary low frequency levels. Some participants were unable to answer any item correctly in these low and mid frequency levels. This suggests that while those students might be able to communicate at a basic level, dealing with reading simplified texts and comprehending listening materials, they may struggle with reading authentic texts, producing a high quality of writing and watching English TV programmes and films.

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