Study of Hall Effect Sensor and Variety of Temperature Related Sensitivity

Hall effect sensors are used in many applications because they are based on an ideal magnetic field sensing technology. The most important factor that determines their sensitivity is the material of which the sensor is made. Properties of the material such as carrier concentration, carrier mobility and energy band gap all vary with temperature. Thus, sensitivity is also influenced by temperature. In this study, current-related sensitivity and voltage-related sensitivity were calculated in the intrinsic region of temperature for two commonly used materials, i.e. Si and GaAs. The results showed that at the same temperature, GaAs can achieve higher sensitivity than Si and it has a larger band gap as well. Therefore, GaAs is more suitable to be used in applications that are exposed to different temperatures

Diabetes among Aboriginal Peoples in Canada: Prevalence and Predictors, 1991-2011

Introduction: Diabetes mellitus is one of several prevalent chronic diseases that has severely impacted Aboriginal Canadians. In addition to high prevalence rates, the characteristics of diabetes among Aboriginal peoples also include early disease onset and severe complications. In general, type 2 diabetes (T2DM) accounts for 90% of all types of diabetes and is recognized to be preventable by improving modifiable factors such as obesity, physical inactivity, unhealthy diet, cigarette smoking and alcohol consumption. Social determinants of health such as low social economic status, household food insecurity, and other cultural factors also play an important role in predicting the development of T2DM by affecting modifiable factors. It is necessary to apply a comprehensive framework that includes both modifiable factors and social determinants in understanding the risk factors of T2DM. Objective: There are two main objectives in this study. The first is to measure trends in diabetes prevalence and related factors from 1991 to 2012 among Aboriginal adults who were classified as Treaty Indians or Registered Indians. The second objective is to examine the associations between modifiable factors and social determinants and T2DM among off-reserve First Nations and Métis adults. Method: In the first part of this study, four cycles (1991, 2001, 2006 and 2012) of the Aboriginal Peoples Survey (APS) were used to examine the changes in prevalence rates of diabetes and related factors during the past twenty years. All rates were age-standardized using the age distribution of 2011 census. The second part of this study focused on the most recent 2012 APS. A set of binary multivariable logistic regression models were applied to examine the associations between independent variables and T2DM. Results: The prevalence rates of all types of diabetes among off-reserve living Registered Indian adults increased from 12.43% in 1991 to 14.54% in 2001, then declined slightly in 2012. The mean age of diabetes diagnosis also increased from 2001 to 2006, then declined in 2012. The prevalence of obesity and regular alcohol consumption has shown an increasing trend, while the prevalence of cigarette smoking has shown a decreasing trend. The percentage of people who have obtained a high school diploma and above increased largely from 1991 to 2012. The median personal income rose from $11,582 to$ 18,098. The employment rate increased from 1991 to 2001, and then declined sharply in 2012. Focused on the 2012 APS, the second part of this study found that being overweight or obese, consuming no alcohol or excessive amounts of alcohol, experiencing very low household food security, and having attended residential schools were significant factors that associated with T2DM. Conclusion: This study confirmed the high prevalence rates of diabetes among Aboriginal peoples in Canada. The prevalence rate of all types of diabetes among off-reserve living Registered Indian adults was still at least two times higher than the national average in 2012. In addition, the pattern observed in diabetes and age onset of diabetes is not evident for the major modifiable factors. This study also found that obesity was an important modifiable factor for T2DM. In addition to modifiable factors, social determinants such as education, income, and household food insecurity, and residential school exposure are also important in predicting T2DM among Aboriginal adults. Therefore, a comprehensive framework including modifiable lifestyle factors, social determinants and cultural factors is needed to be applied in understanding factors of T2DM among Aboriginal peoples. It is also urgent to call upon policy changes on improving household food security, healing residential school trauma, and reducing poverty to provide extra social supports for vulnerable populations

Study on the Extent of the Impact of Data Set Type on the Performance of ANFIS for Controlling the Speed of DC Motor

This paper introduces an adaptive neuro-fuzzy inference system (ANFIS) for tracking SEDC motor speed in order to optimize the parameters of the transient speed response by finding out the perfect training data provider for the ANFIS. The controller was adjusted using PI, PD and PIPD to generate data sets to configure the ANFIS rules. The performance of the ANFIS controllers using these the different data sets was investigated. The efficiencies of the three controllers were compared to each other, where the PI, PD, and PIPD configurations were replaced by ANFIS to enhance the dynamic action of the controller. The performance of the proposed configurations was tested under different operating situations. Matlab's Simulink toolbox was used to implement the designed controllers. The resultant responses proved that the ANFIS based on the PIPD dataset performed better than the ANFIS based on the PI and PD data sets. Moreover, the suggested controller showed a rapid dynamic response and delivered better performance under various operating conditions

Preliminary Exploration of the Mental Health Education Competency Survey of Primary and Middle School Head Teachers

Despite a recent focus on the mental health of students, primary and middle school mental health education in China has been hampered by a lack of resources fand inadequate professional training. This study assessed the mental health education competency of primary and middle school head teachers using the Mental Health Education Competency Questionnaire, a measure based on data from documentary analysis, behavioral event interviews (BEIs), and expert judgment. Factor, reliability, and validity analysis of this questionnaire were conducted. Through these analyses, seven structural dimensions of mental health education competency were found: mental health education skill, career growth, personality charm, occupational tendency, achievement feature, student perspective, and professional knowledge. This questionnaire will improve hiring and evaluation processes and, therefore, improve mental health education

The association of household food security, household characteristics and school environment with obesity status among off-reserve first nations and métis children and youth in Canada: Results from the 2012 aboriginal peoples survey

Introduction: Indigenous children are twice as likely to be classified as obese and three times as likely to experience household food insecurity when compared with non-Indigenous Canadian children. The purpose of this study was to explore the relationship between food insecurity and weight status among Métis and off-reserve First Nations children and youth across Canada. Methods: We obtained data on children and youth aged 6 to 17 years (n = 6900) from the 2012 Aboriginal Peoples Survey. We tested bivariate relationships using Pearson chi-square tests and used nested binary logistic regressions to examine the food insecurity−weight status relationship, after controlling for geography, household and school characteristics and cultural factors. Results: Approximately 22% of Métis and First Nations children and youth were overweight, and 15% were classified as obese. Over 80% of the sample was reported as food secure, 9% experienced low food security and 7% were severely food insecure. Off-reserve Indigenous children and youth from households with very low food security were at higher risk of overweight or obese status; however, this excess risk was not independent of household socioeconomic status, and was reduced by controlling for household income, adjusted for household size. Negative school environment was also a significant predictor of obesity risk, independent of demographic, household and geographic factors. Conclusion: Both food insecurity and obesity were prevalent among the Indigenous groups studied, and our results suggest that a large proportion of children and youth who are food insecure are also overweight or obese. This study reinforces the importance of including social determinants of health, such as income, school environment and geography, in programs or policies targeting child obesity

CMAS-resistance of a yttria graded thermal barrier coating fabricated by plasma activated EB-PVD

EB-PVD yttria stabilized zirconia (YSZ) thermal barrier coatings (TBCs) are susceptible to calcia-magnesia-aluminum-silicate (CMAS) corrosion. The service lifetime of typical 8YSZ TBCs can be significantly reduced by CMAS attack. Currently, composition and microstructure modifications are the most commonly used methods for CMAS infiltration resistance. It has been reported by previous researchers that reactive elements, including Y, Gd, La, and etc., doped in TBCs can promote the formation of a dense protective layer by a sacrificing reaction with CMAS. It is therefore that the CMAS infiltration can be retarded. Besides, tailored columnar grains of TBCs are are also proved to be effective for CMAS mitigation. In this work, TBCs specimens with graded microstructure were fabricated by EB-PVD. The upper region of the TBC was doped with a higher Y2O3 content up to 25 wt.%, compared with the conventional 8YSZ composition. Besides, plasma activation was also introduced in the EB-PVD process to yield a tailored coating morphology and prosity. The coating specimens were tested at 1250 oC for evaluating CMAS resistance. Conventional YSZ coatings and graded coatings without plasma activation were also investigated for comparison

Experimental investigation of the tip based micro/nano machining

Based on the self-developed three dimensional micro/nano machining system, the effects of machining parameters and sample material on micro/nano machining are investigated. The micro/nano machining system is mainly composed of the probe system and micro/nano positioning stage. The former is applied to control the normal load and the latter is utilized to realize high precision motion in the xy plane. A sample examination method is firstly introduced to estimate whether the sample is placed horizontally. The machining parameters include scratching direction, speed, cycles, normal load and feed. According to the experimental results, the scratching depth is significantly affected by the normal load in all four defined scratching directions but is rarely influenced by the scratching speed. The increase of scratching cycle number can increase the scratching depth as well as smooth the groove wall. In addition, the scratching tests of silicon and copper attest that the harder material is easier to be removed. In the scratching with different feed amount, the machining results indicate that the machined depth increases as the feed reduces. Further, a cubic polynomial is used to fit the experimental results to predict the scratching depth. With the selected machining parameters of scratching direction d3/d4, scratching speed 5 μm/s and feed 0.06 μm, some more micro structures including stair, sinusoidal groove, Chinese character ‘田’, ‘TJU’ and Chinese panda have been fabricated on the silicon substrate

An inverse Prandtl–Ishlinskii model based decoupling control methodology for a 3-DOF flexure-based mechanism

A modified Prandtl–Ishlinskii (P–I) hysteresis model is developed to form the feedforward controller for a 3-DOF flexure-based mechanism. To improve the control accuracy of the P–I hysteresis model, a hybrid structure that includes backlash operators, dead-zone operators and a cubic polynomial function is proposed. Both the rate-dependent hysteresis modeling and adaptive dead-zone thresholds selection method are investigated. System identification was used to obtain the parameters of the newly-developed hysteresis model. Closed-loop control was added to reduce the influence from external disturbances such as vibration and noise, leading to a combined feedforward/feedback control strategy. The cross-axis coupling motion of the 3-DOF flexure-based mechanism has been explored using the established controller. Accordingly, a decoupling feedforward/feedback controller is proposed and implemented to compensate the coupled motion of the moving platform. Experimental tests are reported to examine the tracking capability of the whole system and features of the controller. It is demonstrated that the proposed decoupling control methodology can distinctly reduce the coupling motion of the moving platform and thus improve the positioning accuracy and trajectory tracking capability

Uncertainty representation and quantification for a nonlinear rotor/stator system with mixed uncertainties

A rotor-to-stator coupled system usually exhibits complicated dynamic behaviors due to its nonlinear nature. Moreover, the inherent uncertainty (aleatory uncertainty) and many undetermined factors either brought by manufacturing process or due to the lack of knowledge (epistemic uncertainty) make the analysis of system response a challenging task. Existing studies on rotor uncertainties are mostly focused on the stochastic variables, yet pay less attention to other forms of uncertain variables such as intervals. However, some physical parameters (e.g. friction coefficient) can be hardly assigned one specific probability distribution and often available in interval forms. To deal with this, the concept of likelihood is extended from classical discrete point value to interval variable in the presence of mixed uncertainties. A likelihood-based approach is carried out for the mixed uncertainties representation and quantification. In addition, a new single loop sampling algorithm is developed to reduce the computation cost. This framework could be applied in the field of industry manufacturing and mounting, especially take effect in risk assessment and product maintaining. A series of numerical cases are demonstrated for validation and comparison

Interval Type 2 Fuzzy Adaptive Motion Drive Algorithm Design

Motion drive algorithms are a set of filters designed to simulate realistic motion and are an integral part of contemporary vehicle simulators. This paper presents the design of a novel intelligent interval type 2 fuzzy adaptive motion drive algorithm for an off-road uphill vehicle simulator. The off-road, uphill vehicle simulator is used to train and assess the driver’s behavior under varying operational and environmental conditions in mountainous terrain. The proposed algorithm is the first of its kind to be proposed for off-road uphill vehicle simulators, and it offers numerous benefits over other motion drive algorithms. The proposed algorithm enables the simulator to adapt to changes in the uphill road surface, vehicle weight distribution, and other factors that influence off-road driving in mountainous terrain. The proposed algorithm simulates driving on hilly terrain more realistically than existing algorithms, allowing drivers to learn and practice in a safe and controlled environment. Additionally, the proposed algorithm overcomes limitations present in existing algorithms. The performance of the proposed algorithm is evaluated via test drives and compared to the performance of the conventional motion drive algorithm. The results demonstrate that the proposed algorithm is more effective than the conventional motion drive algorithm for the ground vehicle simulator. The pitch and roll responses demonstrate that the proposed algorithm has enabled the driver to experience abrupt changes in terrain while maintaining the driver’s safety. The surge response demonstrated that the proposed MDA handled the acceleration and deceleration of the vehicle very effectively. In addition, the results demonstrated that the proposed algorithm resulted in a smoother drive, prevented false motion cues, and offered a more immersive and realistic driving experience.publishedVersio