Manipulation Errors Research Articles

The Design and Realization of Cherry Tomato Harvesting Robot Based on IOT

To improve the efficiency of harvesting cherry tomato and reduce its breakage rate, we design a harvesting robot base on image recognition and modular control. After image acquisition with IOT technology, the binary processing and expansion and corrosion processing of original image can effectively increase the fruit recognition rate. In addition, the use of fuzzy control technology processes the response error of manipulator. We test the performance of cherry tomato harvesting robot through harvesting experiment. The experimental results show that the harvesting efficiency significantly improves and the degree of crushing cherry tomato greatly reduces after using the cherry tomato harvesting robot.

The Case of Kabylia: Explaining Elective Affinities in Bourdieu’s Mediterranean

A recurrent paradox accompanies Pierre Bourdieu's description of his relation to his earliest field site: the people of Kabylia are frequently evoked as ‘at once exotic and familiar’. In the present article I ask what conditions must prevail for such a depiction to be possible. Taking up work conducted in recent years concerning the details of Bourdieu's fieldwork, its theoretical presuppositions, and its place within the declining French empire, I propose that Bourdieu's depiction is predicated on what Herzfeld calls ‘practical Mediterraneanism’: an ideology of the Mediterranean as a cultural region that permits Bourdieu to negotiate his colonial position, by transmuting a power relation into a relation of cultural similarity. Yet I aim to avoid imputing to Bourdieu a subjective failing in this regard, whether through cynical manipulation or simple error. Instead, pausing on the performative dimension of Bourdieu's texts, I examine what his representations of the Kabyle do throughout his oeuvre and how these are bound by particular intellectual, existential, and political problems that arise at different times.

Is the image “right” for everyone? Introduction to the parallax effect in laparoscopic surgery

During minimally invasive abdominal surgery, a laparoscope is used to film the procedure, which is transmitted to a flat screen monitor. The horizontality of the image depends on the orientation in space and the visual comfort of the surgeon. Observing the screen via a lateral angle of incidence frequently results in the camera assistant making errors in determining the horizontality of the image. Thus, what is "right" for the camera assistant is not necessarily 'right' for the surgeon. We aimed to explain the impact of these errors in laparoscope manipulation, by the description of the parallax effect. To describe this phenomenon of perceptions changing depending on the angle of view, from the basis of the parallax effect, we observed the change of position and for two observers, (the surgeon and the camera assistant) seated at two different locations, using an experimental set up (i.e., photography equipment, a screen and a pelvitrainer). The position of the camera assistant positioned at an angle of incidence of 45° from the surgeon, the observation of the screen with a lateral incidence changes the perception of the image viewed on the screen. For correcting the conflict between the subjective visual perception of the camera assistant and the actual image horizon, the camera assistant instinctively rotates the image, which can lead to an "incorrect" image, deleterious for the surgeon. This article introduces a previously unexplained concept in medical literature, called the parallax effect. The parallax effect results in the camera assistant making systematic errors in determining image horizontality on the screen.

An online method for serial robot self-calibration with CMAC and UKF

The aim of this paper is to propose an online self-calibration method which is used to estimate the kinematic parameters errors of the serial robot manipulators. In this method, a position marker and an inertial measurement unit (IMU) are solidly fixed at the robot end-effector (EE). The position is determined with a position sensor by tracking the marker and the orientation is measured by the IMU in real time. The Factored Quaternion Algorithm (FQA) is used to represent the orientation in a quaternion. In order to eliminate the influence of the noises and the measurement errors from the sensors, the Cerebellar Model Articulation Controller (CMAC) algorithm is adopted to estimate poses of the robot EE. With the estimated poses, the errors between the actual and the nominal kinematic parameters of the robot manipulator could be identified by the Unscented Kalman Filter (UKF). This method only takes several uncomplicated steps but performs with high autonomy and accuracy. Several experiments are carried out with a GOOGOL GRB3016 robot to verify this method and the results indicate that it is indeed of high convenience, precision and efficiency.

Determination of boron concentration in oilfield water with a microfluidic ion exchange resin instrument

We developed and validated a microfluidic instrument for interference-free determination of boron in produced water. The instrument uses a boron-specific chelating resin to separate the analyte from its complex matrix. Ten produced water samples were analyzed with the instrument and the results were successfully validated against ICP-MS measurements. Removing interference effects enables precise boron measurement for wastewater even with high total dissolved solid (TDS) levels. 1,4-Piperazinediethanesulfonic acid conditions the resin and maintains the optimum pH for boron adsorption from the sample. Boron is then eluted from the resin using a 10% sulfuric acid solution and its concentration measured with the colorimetric carminic acid assay in 95% sulfuric acid. The use of a microfluidic mixer greatly enhances the sensitivity and kinetics of the carminic acid assay, by factors of 2 and 7.5, respectively, when compared against the same assay performed manually. A maximum sensitivity of 2.5mg−1L, a precision of 4.2% over the 0–40.0mgL−1 measuring range, a 0.3mgL−1 limit of detection, and a sampling rate of up to four samples per hour were achieved. Automation and microfluidics reduce the operator workload and fluid manipulation errors, translating into safer and higher-quality measurements in the field.

The use of vascular access audit and infections in home hemodialysis.

Vascular access-related infection is an important adverse event in home hemodialysis (HHD). We hypothesize that errors in self-cannulation or manipulation of dialysis vascular access are associated with increased incidence of access-related infection. We conducted a retrospective cohort study of all prevalent HHD patients at the University Health Network. All vascular access-related infections were recorded from 2006 to 2013. Errors in dialysis access were ascertained by nurse-administered vascular access checklist. Ninety-two patients had completed at least one vascular access audit. Median HHD vintage was 2.3 (0.9-5.0) years in patients with appropriate vascular access technique and 5.8 (1.5-9.4) years in patients with erroneous vascular access technique. The overall rate of infection between patients with and without appropriate vascular access technique was similar (0.27 and 0.28 infections per year, P = 0.166). Among patients who were identified with errors in dialysis access manipulation, patients with five or more errors were associated with higher rate of access-related infection (mean of 0.47 vs. 0.16 infection per patient-year, P < 0.001). The use of vascular access audit is a feasible strategy, which can identify errors in vascular access technique. Patients with a longer median HHD vintage are associated with higher risk of inappropriate vascular access technique. Patients with multiple errors in vascular access technique are associated with a higher risk of dialysis access-related infection. Prospective evaluation of the impact of vascular access audit on adverse vascular access events is warranted.

Non-invasive quality evaluation of confluent cells by image-based orientation heterogeneity analysis

In recent years, cell and tissue therapy in regenerative medicine have advanced rapidly towards commercialization. However, conventional invasive cell quality assessment is incompatible with direct evaluation of the cells produced for such therapies, especially in the case of regenerative medicine products. Our group has demonstrated the potential of quantitative assessment of cell quality, using information obtained from cell images, for non-invasive real-time evaluation of regenerative medicine products. However, image of cells in the confluent state are often difficult to evaluate, because accurate recognition of cells is technically difficult and the morphological features of confluent cells are non-characteristic. To overcome these challenges, we developed a new image-processing algorithm, heterogeneity of orientation (H-Orient) processing, to describe the heterogeneous density of cells in the confluent state. In this algorithm, we introduced a Hessian calculation that converts pixel intensity data to orientation data and a statistical profiling calculation that evaluates the heterogeneity of orientations within an image, generating novel parameters that yield a quantitative profile of an image. Using such parameters, we tested the algorithm's performance in discriminating different qualities of cellular images with three types of clinically important cell quality check (QC) models: remaining lifespan check (QC1), manipulation error check (QC2), and differentiation potential check (QC3). Our results show that our orientation analysis algorithm could predict with high accuracy the outcomes of all types of cellular quality checks (>84% average accuracy with cross-validation).

251 A personalized education program allows self-management in adult CF patients for intravenous antibiotic therapy at home

Objective Recurrent intravenous antibiotic (IVA) courses are required for many CF patients with chronic lung infection. These treatments are usually performed by home care nurses. However, to be more independent, some patients perform themselves their IVA infusions without any education and without informing the CF centre. This increases the risk of infection or error in material manipulation. Other patients ask to be educated to this practice. The objective of the project was to propose to CF patients an education program coordinated by the CF centre allowing to self-manage IVA therapy in safety conditions at home. Methods Nurses and physicians of CF centres of Lille (France), in collaboration with a nurse of a service provider and two home care nurses, developed a self-management education program for patients in IVA therapy, including an assessment of patient knowledge, an academic training, a practical training, and then a practical evaluation. Results 2 CF adult patients were included in the program in 2014. They received continuous or every two months IVA therapy on a totally implanted venous catheter. Both of them previously used to self-manage a part of their IVA therapy without any specific education. The patients successfully completed the program. This education program enhances the relationship between patients and caregivers. Conclusion A personalized education program is critical to allow CF patients to self-manage their IVA treatment in safety conditions at home, in partnership with home and hospital caregivers. The program has to be evaluated in a larger population with particular attention to the quality of life.

Model Free Adaptive Control for Robotic Manipulator Trajectory Tracking

This paper considers the problem of trajectory tracking of robotic manipulator system by using model free adaptive control (MFAC). The dynamic linearization technique is first introduced, and then the controller can be designed only by I/O data of the robotic manipulator system via MFAC approach, not includes any explicit model information. With some given conditions for controller parameters, the stability of MFAC for robotic manipulator system can be given. It is shown that the tracking error of robotic manipulator can converge to zero and the better tracking performance can be obtained. Simulation result for two-link robot manipulator further given to valid the effective of the proposed method.

Position and orientation error analysis and its compensation for a wheeled train uncoupling robot with four degrees‐of‐freedom

A wheeled train uncoupling robot with four degrees-of-freedom has been developed to replace humans in the uncoupling task in a marshalling field for designating freight cars to different destinations. To successfully achieve the task in practical applications, the positioning accuracy of the robot is an important issue to be considered. Based on the kinematic model using Denavit–Hartenberg method, the matrix differential method is applied here to establish the static position and orientation error model. The impact of parameter errors upon the static pose error of the uncoupling manipulator is analysed. The flexibility of the robot's key components is taken into consideration to analyse its impact on the position and orientation error of the manipulator. The position and orientation error compensation is developed by using input motion planning method to improve the pose accuracy of the robot. Additional motions are added to each joint of the robot such that the uncoupling manipulator can generate a corresponding tiny perturbation, which is used to eliminate the positioning error, ensuring the uncoupling action is completed successfully.

Performance and Difficulties of Students in Formulating and Solving Quadratic Equations with One Unknown

This study attempts to investigate the performance of tenth-grade students in solving quadratic equations with one unknown, using symbolic equation and word-problem representations. The participants were 217 tenth-grade students, from three different public high schools. Data was collected through an open-ended questionnaire comprising eight symbolic equations and four word problems; furthermore, semi-structured interviews were conducted with sixteen of the students. In the data analysis, the percentage of the students’ correct, incorrect, blank, and incomplete responses was determined to obtain an overview of student performance in solving symbolic equations and word problems. In addition, the students’ written responses and interview data were qualitatively analyzed to determine the nature of the students’ difficulties in formulating and solving quadratic equations. The findings revealed that although students have difficulties in solving both symbolic quadratic equations and quadratic word problems, they performed better in the context of symbolic equations compared with word problems. Student difficulties in solving symbolic problems were mainly associated with arithmetic and algebraic manipulation errors. In the word problems, however, students had difficulties comprehending the context and were therefore unable to formulate the equation to be solved. Thus, it is concluded that the differences in the structural properties of the symbolic equations and word problem representations affected student performance in formulating and solving quadratic equations with one unknown.

Analytical modeling and analysis of the clearance induced orientation error of the RAF translational parallel manipulator

SUMMARYThis paper deals with the analytical modeling and the analysis of the orientation error of the RAF translator due to the clearances in the joints. This model presents the orientation error as a function of the nominal pose, the external load applied to the platform, the manipulator structural parameters, and the joints clearances. Based on this model, an algorithm is developed in order to map the pose error within a desired workspace of the manipulator. It is shown that the orientation error variation depends essentially on the parallelogram configuration of the passive legs out of its plane. The orientation error magnitude is mainly caused by the parallelogram revolute joints radial clearances. Moreover, the orientation error around the z-axis presents some discontinuities due to the contact mode change of the parallelogram revolute joints.

Hedge Fund Performance Using Scaled Sharpe And Treynor Measures

The Sharpe ratio is widely used as a performance measure for traditional (i.e., long only) investment funds, but because it is based on mean-variance theory, it only considers the first two moments of a return distribution. It is, therefore, not suited for evaluating funds characterised by complex, asymmetric, highly-skewed return distributions such as hedge funds. It is also susceptible to manipulation and estimation error. These drawbacks have demonstrated the need for new and additional fund performance metrics. The monthly returns of 184 international long/short (equity) hedge funds from four geographical investment mandates were examined over an 11-year period.This study contributes to recent research on alternative performance measures to the Sharpe ratio and specifically assesses whether a scaled-version of the classic Sharpe ratio should augment the use of the Sharpe ratio when evaluating hedge fund risk and in the investment decision-making process. A scaled Treynor ratio is also compared to the traditional Treynor ratio. The classic and scaled versions of the Sharpe and Treynor ratios were estimated on a 36-month rolling basis to ascertain whether the scaled ratios do indeed provide useful additional information to investors to that provided solely by the classic, non-scaled ratios.

Structure determination from in situ diffraction with the Rigaku PlateMate

As crystallographers face increasing problems with crystallizing new proteins, in-situ screening in crystallization trays at room temperature is experiencing a renaissance. It saves a lot of time when screening large numbers of crystallization hits and it helps avoid crystal damage caused by human manipulation error (harsh manual handling, bad freezing) or changes in crystal properties (dehydration, wrong cryo-conditions). In certain cases, it is also possible to go beyond screening and collect enough data for structure solution, especially on an X-ray home source where a less intense beam helps minimize the devastations of radiation damage occurring at room temperature. The Rigaku PlateMate has proved itself as an efficient and easy-to-use in-situ screening tool on the field for the past two years. It is as easily mounted on a goniometer as a regular goniometer head and thanks to a plate adapter with SBS footprints, it accommodates most 96-wells plate types, from sitting and hanging drop to LCP plates. In addition, thanks to its narrow dimensions and aided by software to prevent collisions with the detector and the crystal viewing camera, the PlateMate can be used to easily collect data from crystals in situ. In this work, we present structure solution results obtained from data collected with the PlateMate on crystals from various proteins (native crystals or containing gold or iodine) and using one or multiple crystals to make up a complete data set.

Poster - Thur Eve - 55: An automated XML technique for isocentre verification on the Varian TrueBeam

Isocentre verification tests, such as the Winston-Lutz (WL) test, have gained popularity in the recent years as techniques such as stereotactic radiosurgery/radiotherapy (SRS/SRT) treatments are more commonly performed on radiotherapy linacs. These highly conformal treatments require frequent monitoring of the geometrical accuracy of the isocentre to ensure proper radiation delivery. At our clinic, the WL test is performed by acquiring with the EPID a collection of 8 images of a WL phantom fixed on the couch for various couch/gantry angles. This set of images is later analyzed to determine the isocentre size. The current work addresses the acquisition process. A manual WL test acquisition performed by and experienced physicist takes in average 25 minutes and is prone to user manipulation errors. We have automated this acquisition on a Varian TrueBeam STx linac (Varian, Palo Alto, USA). The Varian developer mode allows the execution of custom-made XML script files to control all aspects of the linac operation. We have created an XML-WL script that cycles through each couch/gantry combinations taking an EPID image at each position. This automated acquisition is done in less than 4 minutes. The reproducibility of the method was verified by repeating the execution of the XML file 5 times. The analysis of the images showed variation of the isocenter size less than 0.1 mm along the X, Y and Z axes and compares favorably to a manual acquisition for which we typically observe variations up to 0.5 mm.

The Bias Ratio As A Hedge Fund Fraud Indicator: An Empirical Performance Study Under Different Economic Conditions

The Sharpe ratio is widely used as a performance evaluation measure for traditional (i.e., long only) investment funds as well as less-conventional funds such as hedge funds. Based on mean-variance theory, the Sharpe ratio only considers the first two moments of return distributions, so hedge funds characterised by complex, asymmetric, highly-skewed returns with non-negligible higher moments may be misdiagnosed in terms of performance. The Sharpe ratio is also susceptible to manipulation and estimation error. These drawbacks have demonstrated the need for augmented measures, or, in some cases, replacement fund performance metrics. Over the period January 2000 to December 2011 the monthly returns of 184 international long/short (equity) hedge funds with investment mandates that span the geographical areas of North America, Europe, and Asia were examined. This study compares results obtained using the Sharpe ratio (in which returns are assumed to be serially uncorrelated) with those obtained using a technique which does account for serial return correlation. Standard techniques for annualising Sharpe ratios, based on monthly estimators, do not account for serial return correlation this study compares Sharpe ratio results obtained using a technique which accounts for serial return correlation. In addition, this study assess whether the Bias ratio supplements the Sharpe ratio in the evaluation of hedge fund risk and thus in the investment decision-making process. The Bias and Sharpe ratios were estimated on a rolling basis to ascertain whether the Bias ratio does indeed provide useful additional information to investors to that provided solely by the Sharpe ratio.

Hedge Fund Performance Evaluation Using The Sharpe And Omega Ratios

The Sharpe ratio is widely used as a performance evaluation measure for traditional (i.e., long only) investment funds as well as less-conventional funds such as hedge funds. Based on mean-variance theory, the Sharpe ratio only considers the first two moments of return distributions, so hedge funds characterised by asymmetric, highly-skewed returns with non-negligible higher moments may be misdiagnosed in terms of performance. The Sharpe ratio is also susceptible to manipulation and estimation error. These drawbacks have demonstrated the need for augmented measures, or, in some cases, replacement fund performance metrics. Over the period January 2000 to December 2011 the monthly returns of 184 international long/short (equity) hedge funds with geographical investment mandates spanning North America, Europe, and Asia were examined. This study compares results obtained using the Sharpe ratio (in which returns are assumed to be serially uncorrelated) with those obtained using a technique which does account for serial return correlation. Standard techniques for annualising Sharpe ratios, based on monthly estimators, do not account for this effect. In addition, this study assesses whether the Omega ratio supplements the Sharpe Ratio in the evaluation of hedge fund risk and thus in the investment decision-making process. The Omega and Sharpe ratios were estimated on a rolling basis to ascertain whether the Omega ratio does indeed provide useful additional information to investors to that provided by the Sharpe ratio alone.

Finite-time coordination control for networked bilateral teleoperation

SUMMARYA continuous finite-time control scheme for networked bilateral teleoperation is proposed in this brief. The terminal sliding mode technology is used and new master–slave torques are designed. With the new controller, the coordination error of the master manipulator and the slave manipulator converges to zero in finite time. Moreover, the reaching time and the sliding time can be derived. Finally, the comparisons are performed and simulations show the effectiveness of the proposed approach.

Kinematic calibration of a 2-DOF translational parallel manipulator

Two types of kinematic calibration method for a 2-DOF (degrees of freedom) translational parallel manipulator are proposed using different error models. A calibration experiment is performed on both methods using an Absolute Laser Tracker and the results are compared. Two error models of the 2-DOF translational parallel manipulator are established using differential method and linear perturbation method, respectively. The two error models are solved using both the least squares method and linear equations. The results for the two different calibration methods show that the error model based on differential method is more effective in improving the accuracy of the 2-DOF translational parallel manipulator. Overall, the absolute position error of the 2-DOF translational parallel manipulator is significantly reduced to 0.13 mm from 0.93 mm after kinematic calibration.

Testosterone and cardiovascular risk—deciphering the statistics

A recent retrospective study reporting increased risk of cardiovascular events and death with testosterone therapy has received extensive media attention. However, the authors' conclusions are highly questionable given the extensive data manipulation and serious methodological errors. Indeed, a rich body of literature strongly suggests that testosterone therapy offers cardiovascular benefits.