Degree Of Offset Research Articles

Beverage Deterioration Monitoring Based on Surface Tension Dynamics and Absorption Spectrum Analysis

Biochemical information sensing has always been one of the challenges in ubiquitous sensing research for mobile computing. Microorganisms will cause undetectable deterioration in drink production, such as wine and beverage, and microbial contamination is highly susceptible during storage like some liquors can be bottled for sometimes over ten years. Microbial culture methods are common for quality monitoring but unsuitable for real-time beverage quality monitoring. As far as we know, we are the first to use ubiquitous sensing for real-time microbial contamination detection. We designed a lightweight monitoring system called Microbe-Radar, which uses light signals to monitor real-time beverage quality. Microbe-Radar uses eight LEDs and a photodiode to detect fine-grained surface tension and absorption spectrum changes caused by microbial metabolites and growth during deterioration. Characteristic offset degree measurement and absorption spectrum dimension expansion are two critical technologies. Moreover, we implemented countermeasures against ambient light noise and sloshing interference. Microbe-Radar's surface tension and absorption spectrum measurement errors are only 0.89 mN/m and 2.4%, respectively, making identifying the contamination duration, microorganism content, and microorganism composition worthwhile. Experiments showed Microbe-Radar could determine potential issues with liquor quality when the liquid becomes health-threatening or even just contaminated, with an accuracy of 97.5%. Microbe-Radar can also be extended to beverage deterioration warning, with deterioration prediction accuracy of more than 90.6% for five beverages (milk, apple juice, etc.).

Modeling and analysis of vehicle path dispersion at signalized intersections using explainable backpropagation neural networks

The dispersion of vehicular paths is a common phenomenon in the inner area of signalized intersections due to heterogeneous driver behavior and interactions. This study aims to develop an explainable neural network-based model to describe the vehicle path dispersion by exploring the relationship between the path dispersion and external factors. A backpropagation neural network model was established to analyze the effects of external factors on the dispersion of through and left-turn paths based on real trajectory data collected from 20 intersections in Shanghai, China. Twelve influencing factors in varying geometric, traffic, signalization, and traffic management conditions were considered. The predictive power and transferability of the model were verified by applying the trained model on the four new intersections. The contributions of the influencing factors on the path dispersion were explored based on the neural interpretation diagram, relative importance of influencing factors, and sensitivity analysis to offer explanatory insights for the proposed model. The results show that the mean absolute percentage errors of the path dispersion models for the through and left-turn movements are only 14.67% and 17.65%, respectively. The through path dispersion is primarily influenced by the number of exit lanes, the offset degree between the approach and exit lanes, and the traffic saturation degree on the through lane. In contrast, the path dispersion of the left turn is mainly affected by the number of exit lanes, the left-turn angle, and the setting of guide lines.

Regurgitation during the fully supported condition of the percutaneous left ventricular assist device

Objective. A percutaneous left ventricular assist device (PLVAD) can be used as a bridge to heart transplantation or as a temporary support for end-stage heart failure. Transvalvularly placed PLVADs may result in aortic regurgitation due to unstable pump position during fully supported operation, which may diminish the pumping effect of forward flow and predispose to complications. Therefore, accurate characterization of aortic regurgitation is essential for proper modeling of heart-pump interactions and validation of control strategies. Approach. In the present study, an improved aortic valve model was used to analyze the severity of regurgitation produced by different pump position offsets. The link between pump position offset degree and regurgitation is validated in the fixed speed mode, and the influence of pump speed on regurgitation is verified in the variable speed mode, using the mock circulatory loop (MCL) experimental platform. Main results. The greater the pump offset and the more severe the regurgitation, the more carefully the pump speed needs to be managed. To avoid over-pumping, the recommended pump speed in this study should not exceed 30 000 rpm. Significance. The modeling approach provide in this study not only makes it easier to comprehend the impact of regurgitation events on the entire interactive system during mechanical assistance, but it also aids in providing timely alerts and suitable management measures.

Flow Conditioner Design and Analysis Based on Computational Fluid Dynamics

To address the issue of uneven gas flow velocity distribution upstream of natural gas pipeline flow meters, a wave-type fin flow conditioner was designed. The Computational Fluid Dynamics (CFD) numerical simulation method was used to analyze the velocity distribution inside the pipe, and the rectification effect of the flow conditioner was measured by using the offset degree and the minimum length of the straight pipe section. The offset degree at a specific downstream section was calculated when the fluid passed through a 90 degrees elbow spoiler component without a flow conditioner with an Etoile conditioner and wave-type flow conditioner. The results show that the wave-type flow conditioner has a better rectification effect, and the minimum straight pipe section length is shortened by 72% compared to without a flow conditioner, greatly reducing the pipeline design cost and improving the accuracy of measurement of the Ultrasonic flowmeter.

Study on the relationship between vertebrobasilar dolichoectasia and posterior cranial fossa space

ObjectiveTo investigate the correlation between vertebrobasilar dolichoectasia (VBD) and posterior cranial fossa (PCF) space. MethodsThe medical records and imaging data of patients with VBD and control group were collected from June 2021 to June 2022 in the Third People's Hospital of Hubei Province. All patients with VBD were graded by head and neck CTA. The grading index was divided into two parts, including vertebral artery bifurcation height and offset degree. Taking the healthy adult subjects of matched age as the control group. The linear volume of posterior cranial fossa was measured by median sagittal CTA images. Middle clivus length, transverse diameter of occipital foramen, supraoccipital length, sagittal diameter of posterior cranial fossa and height diameter of posterior cranial fossa was measured. The volume of the PCF was calculated by 3Dslice software. The relationship between VBD and the volume of PCF was analyzed by SPSS23.0. ResultsThe height diameter of posterior cranial fossa, sagittal diameter of posterior cranial fossa, transverse diameter of occipital foramen, clival length, supraoccipital length and space volume of PCF were 34.78 ± 3.67 mm, 85.49 ± 4.15 mm, 30.89 ± 3.94 mm, 44.53 ± 5.36 mm, 45.21 ± 6.45 mm, 171.08 ± 15.81 cm3 in the case group. The linear volume of PCF and space volume of PCF were significantly lower than those in the control group (P < 0.05). Binary logistic regression analysis showed that the independent risk factors of VBD were height diameter of PCF, sagittal diameter of PCF, transverse diameter of occipital foramen, clival length, supraoccipital length and space volume of posterior cranial fossa. According to the classification, the height and diameter of PCF in grade 1 was significantly smaller than that in grade 2 VBD (P < 0.05). Under the standard of BA bifurcation degree, there were significant differences between different grades of VBD patients and age (P < 0.05). ConclusionThe smaller volume of PCF may leading the greater possibility of VBD. Under the classification of VBD, the older, the longer the course of disease is, the higher degree of VBD classification is.

3D printing of cementitious mortar with milled recycled carbon fibres: Influences of filament offset on mechanical properties

This study investigates the effects of layer offset on the mechanical strengths of 3D-printed mortar containing milled recycled carbon fibres (rCF). Compared to previous works, the printing scale of carbon-fibre reinforced mortar is increased to move closer to the stage of practical engineering application. For different fibre content, 1.5 vol% is recommended as the optimum fibre dosage for the mortar printing. Three degrees of layer offset are designed for the unidirectional printing pattern, including 0%, 25% and 50% of the filament width as the nozzle drifting distance. X-ray micro-computed tomography analysis demonstrates the internal pore structures in printed specimens consist of channel pores between filaments and micro pores within filaments. The channel pores are generally less geometrically regular than micro pores. Increasing the offset degree leads to improved compressive and flexural strengths along different loading directions. The increase in the compressive strength is more substantial along the direction of layer deposition and lateral expansion compared to the printing direction. Printed specimens with 25% and 50% layer offset also exhibit a much lower level of anisotropy in compression than those without offset. As the degree of layer offset rises, the total porosity decreases and the volume percentage of micro pores in total pores increases, thereby rendering less severe stress concentration around defects and strengthening the mechanical performance of printed specimens. The experiment results show the 3D-printed mortar containing milled rCF with layer offset, normally serving for self-sensing purpose, has the potential to achieve decent mechanical properties for large-scale industrial printing.

A Systematic Study to Compare the Precise Implantation of Hololens 2 Assisted with Acetabular Prosthesis for Total Hip Replacement

This study aims to evaluate the accuracy of the precise implantation of Hololens 2 assisted with acetabular prosthesis for total hip replacement. A total of 80 orthopaedic doctors from our hospital are enrolled in this systematic study and these doctors are divided into following four groups based on the experience of doctors treatment for orthopaedic patients and the Hololens 2 assisted:Rich experienced group with Hololens 2, rich experienced group without Hololens 2, inexperienced group with Hololens 2, inexperienced group without Hololens 2. The abduction angle, the anteversion angle, the offset degree in the abduction angle, the offset degree in the anteversion angle in four groups are presented and these result are used to evaluate the accuracy of precise implantation of Hololens 2 assisted with acetabular prosthesis for total hip replacement. Finally, all date in this study is collected and analyzed. The total of 80 physicians are included in this study. The results show that the outcomes between rich experienced group with Hololens 2 and rich experienced group without Hololens 2 are significant difference, and the outcomes between inexperienced group with Hololens 2 and inexperienced group without Hololens 2 are significant difference. The result between any other two groups is no significant difference. Hololens 2 assisted with acetabular prosthesis for total hip replacement can improve the accuracy.

Magnetic flux leakage detection method by the arrays consisted of three-dimensional hall sensor for rail top surface cracks

It is difficult for a single sensor to fully grasp the leakage magnetic flux properties of the cracks on the top surface of the rail. Therefore, A square array, a circular array, and a cross array which be consisted of three-dimensional hall sensors is designed. The rail inspection vehicle carries the different kinds of arrays to detect magnetic flux leakage for the cracks on the top of rails of different lengths through different paths. Analyse the change law of magnetic flux leakage signal, extract the ring-differential characteristics of each dimension and the geometric characteristics of the peak height, waveform width, envelope area, peak and valley width of the magnetic flux leakage signal curve, then analyse the influence on the magnetic flux leakage signal when the rail inspection vehicle passing through the cracks from different paths. Experimental results show that the detection by different kinds of arrays can dig out more featured information, and the offset degree of the detected magnetic flux signals from the sensor arrays has relationship with the path which the rail inspection vehicle passed through and the centre line of the sensor array carried on the rail inspection vehicle.

Effect of Lance Design on Jet Characteristics in 250 t Converter

The supersonic jet characteristics of the oxygen lance nozzle play an important role in converter melting. However, limited studies have investigated the different nozzle arrangements to improve the jet characteristics. This study uses FLUENT to establish a compressible nonisothermal computational fluid model with a 250 t converter as the object, and the model first validates and then discusses the effects of the center hole and postcombustion (PC) oxygen lance secondary hole on the aggregation behavior and impact area of the oxygen jet based on the conventional five‐hole oxygen lance. The study shows that, at the same distance, the influence of the peripheral jet offset degree from small to large is secondary hole–center hole–secondary hole with center hole. At the lance height of 1900 mm, compared to the traditional five‐hole oxygen lance offset theoretical axial centerline distance is 1.98, 2.31, and 3.20 times. The larger the jet migration degree of the peripheral hole, the smaller is the velocity of the peripheral jet. The presence of center hole, secondary hole, and center hole with secondary hole encloses 1.04, 1.09, and 1.47 times the area enclosed by the conventional five‐hole oxygen lance at 150 m s−1 isovelocity line, respectively.

Spatiotemporal evolution of sustainable development of China’s provinces: a modelling approach

ABSTRACT Three sustainable development sub-indicators were established along with 49 indicators of sustainable development at the provincial level. We collected data for the key years of 2010, 2015, and 2018 and evaluated the sustainable development level of 31 provinces in China by using the best and worst value improved equal-weight TOPSIS method. With spatial autocorrelation and hotspot analysis, the spatial characteristics of the sustainable development level were studied. Grey correlation analysis and the offset degree index were also used to find out which indicators should be of most concern to improve the level of sustainable development. The results showed the following. (1) The level of sustainable development of China’s provinces is increasing, but there is a decrease from east to west. (2) In terms of sustainable development, the gap between the four major economic regions is narrowing. (3) The overall sustainable development level is highly consistent with the mainstream green development and the human development index, indicating that exploiting the driving force behind developing and improving the quality of development is the key to China’s sustainable development strategy. (4) Different measures should be taken to promote the realization of Sustainable Development Goals in different areas.

Miniature All-Optical Angle-Focused Photoacoustic Transducer

This letter presents the design, fabrication and testing of an all-optical transducer based on a photoacoustic principle. The transducer consists of a fiber optic acoustic generator and a Fabry–Perot (FP) sensor. A lens fabricated with UV glue and Gold Nanocomposites coating were mounted on the distal end of a multimode optical fiber with 400/ $425~\mu \text{m}$ core/cladding to fabricate the generator. The lens was designed with a certain offset degree and a concaved surface to module the propagation direction and focal length of acoustic waves emitted by the generator. The FP sensor was made of PDMS between two gold layers using a single mode fiber. The validation test demonstrated promising applications in miniature space, harsh environments and even vivo tissue.

Comparison of microstructures and mechanical properties of composite extruded AZ31 sheets

Abstract The microstructures and mechanical properties of the composite extruded AZ31/AZ31 and AZ31/4047 Al sheets were investigated and made a comparison to the conventional extruded AZ31 sheet. Owing to the introduced intense shear deformation at the interface during the composite extrusion, grain refinement and tilted texture were detected in AZ31 layers of the AZ31/AZ31 and AZ31/4047 Al sheets, while the conventional extruded AZ31 sheet exhibited a relative coarse, inhomogeneous microstructure and strong basal texture. The compression-tension yield ratio was increased gradually from the AZ31 to the AZ31/AZ31 and AZ31/4047 Al sheets. Besides, the AZ31/4047 Al sheet could successfully accomplish the whole bending forming process at room temperature, while the AZ31 and AZ31/AZ31 sheets were both bend-formed to failure with significant cracks in the outer tensile region under the identical bending parameters. Moreover, under the same bending strain, both the outward offset degree of strain neutral layer and the sheet thickening were more serious in the AZ31/4047 Al composite sheet than those of the AZ31 and AZ31/AZ31 sheets. The foremost reason was the quite wide gap of material properties between Mg alloy AZ31 layer (tensile loading in the outer region) and Al 4047 layer (compressive loading in the inner region).

Mechanism of affecting the axial rotor stability and performance with center offset degrees of axial skewed slots

A subsonic axial rotor with axial skewed slot casing treatment (ASSCT) was investigated with experimental and numerical methods to explore the effects of the center offset degree (Cod) on the rotor stability and performance. Cod is defined as the ratio of the central difference between the rotor tip section and ASSCT to the rotor tip axial chord length. The Cod values are selected as 1.16, 0.608, 0, and −0.36, respectively. When the ASSCT is located upstream, the value of the Cod is positive. The experimental and unsteady calculated results show that the stall margin improvement (SMI) and peak efficiency loss (PEL) are reduced when the slots move to the rotor upstream or downstream. The slots with 0 Cod (ASSCT1) achieve 50% SMI with 8.67% PEL. The slots with 0.608 Cod (ASSCT2) gain 48.5% SMI with 2.12% PEL. The slots with 1.16 Cod (ASSCT3) and −0.36 Cod (ASSCT4) gain −3.41%, 20.1% SMI, respectively. Considering the compromise between the SMI and PEL for the rotor, ASSCT5 was designed by changing the slot number of ASSCT2 from 180 to 90. The unsteady calculated result shows that ASSCT5 can gain 22.28% SMI and 0.485% PEL. The detailed analysis of the flow field in the compressor tip passage indicates that there are adverse effects made by the slots on the flow field near the rotor blade tip leading edge for ASSCT3. Moreover, the ability of reducing the range of low-velocity zones for ASSCT4 is much lower than that for ASSCT1 or ASSCT2, and ASSCT1 generates bigger flow losses in the rotor tip passage than ASSCT2. The positive effects and flow losses made by the slots with 0.608 Cod both become smaller with the slot number decreasing from 180 to 90.

A maintenance support framework based on dynamic reliability and remaining useful life

Traditional maintenance support methods provide the maintenance strategy of equipment based on failure data from a number of similar equipment, without taking into account the specificity of degradation process. In this paper, a maintenance support framework based on dynamic reliability (DR) assessment and remaining useful life (RUL) prediction is developed for enhancing the practical maintenance activities from both statistical and individual perspective. First, a multi-factor fused DR assessment method is defined based on state offset degree, which can provide a more accurate DR result from the individual perspective. Second, a modified similarity-based RUL prediction method is proposed to improve prediction accuracy and reduce late prediction from the statistical perspective. In the end, a maintenance support model is defined based on RUL prediction and DR assessment, which can help managers to generate an effective maintenance strategy. A case study is provided to verify the effectiveness of the proposed method.

Assessment Method of Slope Excavation Quality based on Point Cloud Data

Slope excavation quality assessment is essential in water conservancy engineering. This study presents a quality assessment method to estimate the excavation quality of a slope based on point cloud data obtained from a 3D Terrestrial Laser Scanner (TLS). A data processing method, which includes coordinate registration, data partitioning, and noise removal, is proposed to organize raw data from the TLS and ensure accurate and available point cloud data of a slope surface. An excavation quality assessment method with seven indicators, namely, slope ratio, slope toe elevation, back break, volume of back break, remained semi-void rate, unevenness, and offset degree, is proposed to analyze the difference between a slope’s as-design excavation appearance and actual construction appearance. The as-design excavation appearance is expressed by the Building Information Modeling (BIM) model of a slope-excavation face, and it is a reference to assess the actual construction appearance. The slope excavation quality of a water conservancy project in southwest China is evaluated with the proposed method and the traditional method. The results demonstrate that the proposed method can estimate the slope excavation quality effectively, rapidly, and accurately, and can provide theoretical data support for subsequent work.

Recognition of Blast Furnace Gas Flow Center Distribution Based on Infrared Image Processing

AbstractTo address the problems about the difficulty in accurate recognition of distribution features of gas flow center at blast furnace throat and determine the relationship between gas flow center distribution and gas utilization rate, a method for recognizing distribution features of blast furnace gas flow center was proposed based on infrared image processing, and distribution features of blast furnace gas flow center and corresponding gas utilization rates were categorized by using fuzzy C-means clustering and statistical methods. A concept of gas flow center offset was introduced. The results showed that, when the percentage of gas flow center without offset exceeded 85%, the average blast furnace gas utilization rate was as high as 41%; when the percentage of gas flow center without offset exceeded 50%, the gas utilization rate was primarily the center gas utilization rate, and exhibited a positive correlation with no center offset degree; when the percentage of gas flow center without offset was below 50% but the sum of the percentage of gas flow center without offset and that of gas flow center with small offset exceeded 86%, the gas utilization rate depended on both the center and the edges, and was primarily the edge gas utilization rate. The method proposed was able to accurately and effectively recognize gas flow center distribution state and the relationship between it and gas utilization rate, providing evidence in favor of on-line blast furnace control.

Nonparametric modeling and vibration analysis of uncertain Jeffcott rotor with disc offset

Uncertainty is extensively involved in the rotor systems of rotating machinery. The nonparametric modeling technique is first extended to the uncertain Jeffcott rotor with disc offset, and the random matrix model is established. Based on the Monte Carlo method, the effects of the dispersion parameters and the external bounded noise excitation on the vibrational characteristics of the system, such as the critical speed and the vibration amplitude, are investigated. Importance of different parameters is distinguished by sensitivity analysis of the first-order critical speed. It is shown that the critical speed increases with the increase of the offset degree of the disc and will also fluctuate due to the uncertainties, while the vibration amplitude fluctuates within the region enclosed by the upper and the lower envelopes of all the sample amplitudes, with the mean in ensemble close to the values calculated by the deterministic mean model. When the unbalanced force and the bounded noise excitation are imposed on the uncertain Jeffcott rotor, the fluctuation ranges of the critical speed and the vibration amplitude are further widened, and the maximum vibration amplitude can be more than double of the mean values. It is suggest that uncertainties of some sensitive parameters have to be treated carefully while others can be neglected.

Degree formulae for offset curves

In this paper, we present three different formulae for computing the degree of the offset of a real irreducible affine plane curve C given implicitly, and we see how these formulae particularize to the case of rational curves. The first formula is based on an auxiliary curve, called S , that is defined depending on a non-empty Zariski open subset of R 2 . The second formula is based on the resultant of the defining polynomial of C , and the polynomial defining generically S . The third formula expresses the offset degree by means of the degree of C and the multiplicity of intersection of C and the hodograph H to C , at their intersection points.

Performance evaluation and application of channel offset schemes in indoor channel assignments

We deal with channel offset schemes and their application in three-dimensional (3-D) frequency reuse environments with ideal cubic microcells. Formulas are derived to calculate channel reuse distances (CRDs) and interchannel usage distances (IUDs) for a given offset degree. For an indoor personal communication network (PCN), an algorithm is proposed for fixed channel assignment with channel offset. The spectral efficiency of channel offset schemes is discussed and the results show that compared to the channel offsetless scheme, channel offset schemes make more efficient use of limited spectrum resources.