A Self-calibration Bundle Adjustment Algorithm Based on Block Matrix Cholesky Decomposition Technology

In this study,the problem of bundle adjustment was revisited,and a novel algorithm based on block matrix Cholesky decomposition was proposed to solve the thorny problem of self-calibration bundle adjustment.The innovation points are reflected in the following aspects:①The proposed algorithm is not dependent on the Schur complement,and the calculation process is simple and clear;②The complexities of time and space tend to O(n)in the context of world point number is far greater than that of images and cameras,so the calculation magnitude and memory consumption can be reduced significantly;③The proposed algorithm can carry out self-calibration bundle adjustment in single-camera,multi-camera,and variable-camera modes;④Some measures are employed to improve the optimization effects.Experimental tests showed that the proposed algorithm has the ability to achieve state-of-the-art performance in accuracy and robustness,and it has a strong adaptability as well,because the optimized results are accurate and robust even if the initial values have large deviations from the truth.This study could provide theoretical guidance and technical support for the image-based positioning and 3D reconstruction in the fields of photogrammetry,computer vision and robotics.

A Fractional-N CMOS DPLL with Self-Calibration

A digital phase-locked loop （DPLL） based on a new digital phase-frequency detector is presented. The self-calibration technique is employed to acquire wide lock range,low jitter, and fast acquisition. The DPLL works from 60 to 600MHz at a supply voltage of 1.8V. It also features a fraetional-N synthesizer with digital 2nd-order sigma-delta noise shaping, which can achieve a short lock time,a high frequency resolution,and an improved phase-noise spectrum. The DPLL has been implemented in SMIC 0. 18μm 1.8V 1P6M CMOS technology. The peak-to-peak jitter is less than 0. 8% of the output clock period and the lock time is less than 150 times of the reference clock period after the pre-divider.

Capacitor self-calibration technique used in time-interleaved successive approximation ADC

A capacitor self-calibration circuit used in a successive approximation analog-to-digital converter （SA-ADC） is presented. This capacitor self-calibration circuit can calibrate erroneous data and work with the ADC by adding an additional clock period. This circuit is used in a 10 bit 32 Msample/s time-interleaved SA- ADC. The chip is implemented with Chart 0. 25 μm 2. 5 V process and totally occupies an area of 1.4 mm× 1.3 mm. After calibration, the simulated signal-to-noise ratio （SNR） is 59. 586 1 dB and the spurious-free dynamic range （SFDR） is 70. 246 dB at 32 MHz. The measured signal-to-noise and distortion ratio （SINAD） is 44. 82 dB and the SFDR is 63. 760 4 dB when the ADC samples a 5.8 MHz sinusoid wave.

Validation And Reliability of Distress Thermometer in Chinese Cancer Patients

Objective：To examine the validation and reliability of the distress thermometer（DT） recommended by National Comprehensive Cancer Network（NCCN） in Chinese cancer patients.Methods：A total of 574 Chinese cancer patients from Beijing Cancer Hospital completed the detection of DT,the Hospital Anxiety and Depression Scale（HADS） and Symptom Checklist 90（SCL-90）,Receiver Operating Characteristic（ROC） curve and Area Under the Curve（AUC） were used to analyze the validation relative to HADS and SCL-90.The patients with DT≥4 and whose distress caused by emotional problems were interviewed with the MiNi International Neuro-psychiatric Interview（MINI）（Chinese Version 5.0）.This version was used to analyze cancer patients＇ psychological and Psychiatric symptoms during the cancer process;3.Another 106 cancer patients in rehabilitation stage and stable condition were asked to fill in DT two times,at the base time and after 7-10 days.Results：Data of ROC indicates that a DT cutoff score of 4 yielded AUC of 0.80 with a optimal sensitivity（0.80） and specificity（0.70） relative to HADS,and AUC of 0.83 with the greatest sensitivity（0.87） and specificity（0.72） against SCL-90.The DT also has acceptable test-retest reliability（r=0.800,P=0.000）;According to the interview results,the most common psychiatric problems cancer patients have adjustment disorder,depression,and anxiety.Conclusion：The data suggest that DT has acceptable overall accuracy and reliability as a screening tool for testing distress severity and specific problems causing distress in Chinese cancer patients.It is worth being used in oncology clinic,the rapid screening and interview could help caregivers to identify psychological and psychiatric problems of cancer patients and provide useful information for further treatment.

Validity of distress thermometer for screening of anxiety and depression in family caregivers of Chinese breast cancer patients receiving postoperative chemotherapy

Objective:Family caregivers(FCs)of breast cancer patients play a vital role throughout the treatment process.Psychological distress of FCs is common and often ignored.A simple and effective instrument for screening psychological distress would help in selecting those FCs requiring special attention and intervention.Here,the validity of distress thermometer(DT)in FCs of Chinese breast cancer patients receiving postoperative chemotherapy was assessed,and the prevalence of anxiety and depression was evaluated.Methods:We recruited 200 FCs of hospitalized breast cancer patients in this cross-sectional descriptive study.Before the first cycle of adjuvant chemotherapy,the levels of anxiety and depression among FCs were assessed using DT and Hospital Anxiety and Depression Scale(HADS).In total,191 valid cases were analyzed.HADS was used as the diagnostic standard to assess the effectiveness of DT as a screening tool for anxiety and depression as well as to analyze the diagnostic efficiency of DT at various cutoff points.Results:The definitive prevalence of both anxiety and depression was 8.90%.The mean level of anxiety and depression among FCs was 5.64±3.69 and 5.09±3.85,respectively,both of which were significantly higher than corresponding Chinese norms(P<0.01).The areas under receiver operating characteristic curves of DT for the diagnoses of FCs'anxiety and depression were 0.904 and 0.885,respectively.A cutoff value of 5 produced the best diagnostic effects of DT for anxiety and depression.Conclusions:The levels of both anxiety and depression were higher in the FCs of Chinese breast cancer patients receiving postoperative chemotherapy than the national norm.DT might be an effective tool to initially screen psychological distress among FCs.This process could be integrated into the palliative care of breast cancer patients and warrant further research.

Self-calibration and Compensation of Setting Errors for Surface Profile Measurement of a Microstructured Roll Workpiece

Microstructured roll workpieces have been widely used as functional components in the precision industries. Current researches on quality control have focused on surface profile measurement of microstructured roll workpieces, and types of measurement systems and measurement methods have been developed. However, low measurement efficiency and low measurement accuracy caused by setting errors are the common disadvantages for surface profile measurement of microstructured roll workpieces. In order to shorten the measurement time and enhance the measurement accuracy, a method for self-calibration and compensation of setting errors is proposed for surface profile measurement of microstructured roll workpieces. A measurement system is constructed for the measurement, in which a precision spindle is employed to rotate the roll workpiece and an air-bearing displacement sensor with a micro-stylus probe is employed to scan the microstructured surface of the roll workpiece. The resolution of the displacement sensor is 0.14 nm and that of the rotary encoder of the spindle was 0.15r~. Geometrical and mathematical models are established for analyzing the influences of the setting errors of the roll workpiece and the displacement sensor with respect to the axis of the spindle, including the eccentric error of the roll workpiece, the offset error of the sensor axis and the zero point error of the sensor output. Measurement experiments are carded out on a roll workpiece on which periodic microstructures are a period of 133 i^m along the circumferential direction. Experimental results demonstrate the feasibility of the self-compensation method. The proposed method can be used to detect and compensate the setting errors without using any additional accurate artifact.

Integration of Tracer Test Data to Refine Geostatistical Hydraulic Conductivity Fields Using Sequential Self-Calibration Method

On the basis of local measurements of hydraulic conductivity, geostatistical methods have been found to be useful in heterogeneity characterization of a hydraulic conductivity field on a regional scale. However, the methods are not suited to directly integrate dynamic production data, such as, hydraulic head and solute concentration, into the study of conductivity distribution. These data, which record the flow and transport processes in the medium, are closely related to the spatial distribution of hydraulic conductivity. In this study, a three-dimensional gradient-based inverse method--the sequential self-calibration （SSC） method--is developed to calibrate a hydraulic conductivity field, initially generated by a geostatistical simulation method, conditioned on tracer test results. The SSC method can honor both local hydraulic conductivity measurements and tracer test data. The mismatch between the simulated hydraulic conductivity field and the reference true one, measured by its mean square error （MSE）, is reduced through the SSC conditional study. In comparison with the unconditional results, the SSC conditional study creates the mean breakthrough curve much closer to the reference true curve, and significantly reduces the prediction uncertainty of the solute transport in the observed locations. Further, the reduction of uncertainty is spatially dependent, which indicates that good locations, geological structure, and boundary conditions will affect the efficiency of the SSC study results.

Intestinal obstruction due to migration of a thermometer from bladder to abdominal cavity:A case report

Intraperitoneal foreign bodies such as retained surgical instruments can cause intestinal obstruction.However,intestinal obstruction due to transmural migration of foreign bodies has rarely been reported.Here,we report a case of intestinal obstruction due to a clinical thermometer which migrated from the bladder into the abdominal cavity.A 45-year-old man was admitted to our hospital with a one-year history of recurrent lower abdominal cramps.Two days before admission,the abdominal cramps aggravated.Intestinal obstruction was confirmed with upright abdominal radiography and computerized tomography scan which showed dilation of the small intestines and a thermometer in the abdominal cavity.Then laparotomy was performed.A scar was observed at the fundus of the bladder and a ther-mometer was adhering to the small bowels and mesentery which resulted in intestinal obstruction.Abdominal cramps were eliminated and defecation and flatus recovered soon after removal of the thermometer.

Does central tympanic membrane perforation affect infrared tympanic thermometer measurements in adults?

Objective: Infrared Tympanic Thermometer(ITT) is one of the most useful instruments for accurately measuring temperature. The effects of ear pathologies on ITT measurement remain unclear. The purpose of this study is to determine if tympanic membrane perforation(TMP) affects ITT measurements in adult patients.Material and methods: A total of 90 adult patients with monaural central TMP were enrolled in this study.Patients were categorized into three subgroups according to perforation size(1-3 mm, 4-7 mm, and 8-10 mm).The tympanic temperatures of the affected and unaffected sites, and subgroups were compared with each other.Results: This study contained 54(60%) males and 36(40%) females ranging from 20 to 58 years of age(mean age: 30.74 ± 9.61 years). The mean tympanic temperature of the side affected with TMP was 36.34 oC ± 0.61 oC.The mean tympanic temperature of the unaffected side with healthy and intact tympanic membrane was 36.33 oC ± 0.6 oC. The Pearson correlation score for the tympanic temperatures and the size of TMP was 0.22 which was not significant(r=-0.12).Conclusion: TMP and perforation size do not affect ITT measurements in adult patients.

New self-calibration approach to space robots based on hand-eye vision

To overcome the influence of on-orbit extreme temperature environment on the tool pose(position and orientation) accuracy of a space robot,a new self-calibration method based on a measurement camera(hand-eye vision) attached to its end-effector was presented.Using the relative pose errors between the two adjacent calibration positions of the space robot,the cost function of the calibration was built,which was different from the conventional calibration method.The particle swarm optimization algorithm(PSO) was used to optimize the function to realize the geometrical parameter identification of the space robot.The above calibration method was carried out through self-calibration simulation of a six-DOF space robot whose end-effector was equipped with hand-eye vision.The results showed that after calibration there was a significant improvement of tool pose accuracy in a set of independent reference positions,which verified the feasibility of the method.At the same time,because it was unnecessary for this method to know the transformation matrix from the robot base to the calibration plate,it reduced the complexity of calibration model and shortened the error propagation chain,which benefited to improve the calibration accuracy.

Application of Distress Thermometer in Patients with Prostatic Cancer and Prostatitis

Objective: To discuss the application of distress thermometer (DT) on psychological pain in primary hospital patients with prostatic cancer (Pca) and prostatitis;and to analyze the present status and related factors of psychological pain in these patients. Methods: Questionnaire survey of DT and related problem lists were carried out in 168 patients with Pca and 226 patients with prostatitis. The data were input to EXCEL and analyzed with SPSS 18.0. The statistical description was used to analyze the graded of psychological pain. Square test and Logistic regression were used to analyze influence factors of significant psychological distress. Pearson correlation analysis was used to assess the correlation between psychological distress and related problems. Results: Psychological pain score of Pca patients and prostatitis patients were 3.42 ± 1.86 and 3.02 ± 1.75, respectively. Moderate to severe degree of pain accounted for 69.6% in Pca patients, compared to 49.1% in prostatitis patients. In Pca and prostatitis patients, marital status, age, educational backgrounds and income were associated. Physical and emotional problems were the top two items having the highest score. Psychological distress score was positively correlated with physical problems, emotional problems, practical problems and communication problems in both Pcar and prostatitis patients. Conclusion: The Distress Thermometer can be used to assess the severity and explore the causes of psychological distress in Pca patients and prostatitis patients. Our study could help detecting the degree and reason of psychological distress, and provide evidence for the possibility of future personalized intervention to treat medical mental problems in primary hospital.

Camera Self-Calibration in Computer Vision with Precise Estimation of Initial Parameters

A key problem that plagues camera self-calibration, namely that the classical self-calibration algorithms are very sensitive to the initial values of the camera intrinsic parameters, is analyzed and a practical solution is provided. The effect of the camera intrinsic parameters, mainly the principal point and the skew factor is first discussed. Then a practical method via a controlled motion of the camera is introduced so as to obtain an accurate estimation of these parameters. Feasibility of this approach is illustrated by carrying out comprehensive experiments using synthetic data as well as real image sequences. Unreasonable initial values can often make self-calibration impossible, yet a precise initialization guarantees a better and successful reconstruction. Trying to obtain a more reasonable initialization is worthwhile the effort in camera self-calibration.

An improved self-calibration approach based on adaptive genetic algorithm for position-based visual servo

An improved self-calibrating algorithm for visual servo based on adaptive genetic algorithm is proposed in this paper. Our approach introduces an extension of Mendonca-Cipolla and G. Chesi＇s self-calibration for the positionbased visual servo technique which exploits the singular value property of the essential matrix. Specifically, a suitable dynamic online cost function is generated according to the property of the three singular values. The visual servo process is carried out simultaneous to the dynamic self-calibration, and then the cost function is minimized using the adaptive genetic algorithm instead of the gradient descent method in G. Chesi＇s approach. Moreover, this method overcomes the limitation that the initial parameters must be selected close to the true value, which is not constant in many cases. It is not necessary to know exactly the camera intrinsic parameters when using our approach, instead, coarse coding bounds of the five parameters are enough for the algorithm, which can be done once and for all off-line. Besides, this algorithm does not require knowledge of the 3D model of the object. Simulation experiments are carried out and the results demonstrate that the proposed approach provides a fast convergence speed and robustness against unpredictable perturbations of camera parameters, and it is an effective and efficient visual servo algorithm.

NOVEL METHOD FOR ERROR ANALYSIS AND SELF-CALIBRATION OF LASER TRACKING MIRROR MECHANISM

Laser tracking system （LTS） is an advanced device for large size 3D coordinates measuring with the advantages of broad range, high speed and high accuracy. However, its measuring accuracy is highly dominated by the geometric errors of the tracking mirror mechanism. Proper calibration of LTS is essential prior to the use of it for metrology. A kinematics model that describes not only the motion but also the geometric variations of LTS is developed. Through error analysis of the proposed model, it is claimed that gimbals axis misalignments and tracking mirror center off-set are the key contributors to measuring errors of LTS. A self-calibration method is presented of calibrating LTS with planar constraints. Various calibration strategies utilizing single-plane and multiple-plane constraints are proposed for different situations. For each calibration strategy, issues about the error parameter estimation of LTS are exploded to find out in which conditions these parameters can be uniquely estimated. Moreover, these conditions reveal the applicability of the planar constraints to LTS self-calibration. Intensive studies have been made to check validity of the theoretical results. The results show that the measuring accuracy of LTS has increased by 5 times since this technique for calibration is used.

Comparative Thermometery in Paediatric Age Group: Is the Non-Touch Infrared Thermometer (NTIT) Reading Comparable to Regular Mercury-in-Glass Thermometer (MIGT) Reading?

Background: Accurate temperature measurement is a critical step in evaluating health or disease especially in children and immmunocompromised subjects;inaccurate measurement may lead to improper diagnosis, wrong treatment or inappropriate intervention. Several methods of temperature measurements exist and comparing these gives room for choosing a near ideal method in terms of speed, safety and accuracy. The study aimed to compare the forehead non touch infra-red thermometer with the axilllary mercury-in-glass method of temperature measurement in the Paediatric age-group. Methods: Study was given ethical approval as part of a larger study. Four hundred and thirty seven children aged 1 to 24 months were studied at the well-baby/immunizationclinic of the University of Ilorin Teaching Hospital over a 6-months period. Both non-touch infrared and theregular mercury-in-glass thermometers were used to take the body temperatures. Data were analysed with SPSS version 21. Pearson correlation was used to determine the relationship between the two methods of temperature measurements, while Bland-Altman method was used to test for level of agreement between them. Results: The mean age and SD was 5.81 ± 4.04 months. Pearson correlation showed a positive correlation between the axillary mercury-in-glass and forehead non-touch infra-red thermometry readings (r = 0.281, p < 0.001). Also, Bland-Altman method revealed a good agreement between both methods of thermometry as 96% of the readings were within the limits of agreement. Mean difference was 0.09°C (95% confidence interval 0.05 - 0.13). Conclusion: Axillary mercury-in-glass thermometer and forehead non touch infra-red thermometers have a good agreement and can be used interchangeably.

Application of a Modified Distress Thermometer to Screen for Psychological Distress in 140 Patients with Malignancies,and an Analysis of Related Factors

Objective A modified Distress Thermometer(DT)was applied to explore the status of psychological distress in patients with malignant tumors and to analyze the related factors influencing psychological distress.Methods The modified DT was used to screen for psychological distress in 140 patients with malignant tumors in the Cancer Center of the First Hospital of Jilin University.Aχ2 test was used to analyze the effects of age and gender on psychological distress;risk factors associated with significant psychological distress(DT≥4)were further analyzed by Stepwise Logistics Regression.Spearman’s Correlation Analysis was used to determine the correlations among the items in the problems list(economic problems,fatigue,eating,pain,nausea,constipation,decreased memory/inattention,anxiety,tension,sleep).Results The results of the modified DT screening showed that the rate of significant psychological distress was 33.57%in patients with malignant tumors,and females and elderly patients were more likely to suffer significant psychological distress(P=0.048;P=0.002).A dry/congestive nose,depression,having to work/go to school,bathing/dressing,and nausea were significant factors or situations associated with psychological distress in patients with malignant tumors,and physical and emotional problems often appeared together in the problems list.Conclusion The modified DT reflected the degree of each symptom(to a certain extent),and could accurately and concretely identify the major cause(s)of the patients’psychological distress,so that the clinical medical care workers could target the problems and improve the patients’quality of life.

Smart Resistance Thermometer Sensor Based on C8051F350

A Smart resistance thermometer sensor is designed to overcome the shortages of the traditional ones, and Con-form to the world development trend of the sensor market.According to the constitutions of this Smart sensor and its application coverage,those parts with good -application and low-cost were chosen to constitute this sensor on the basis of full consideration of the linkage among every part.The whole testing system were controlled and processed by C8051F350 single-chip,it could measure precise temperature by PT100 resistance thermometer and circumstance temperature for temperature compensating automatically and simultane-ously,it also could amplify signals to convert analog signals to digital ones,and display results automatically by analysing and processing information.Furthermore,it could auto-compensate self-check,and spot communicate.

Self-calibration Applied in Converting Simulation Surveying

In the field of converting simulation surveying and traditional close range photogrammetry, it has been developed so far to survey objects by commercial digital camera and this technique is applied widely in every part of production. In order to get three-dimensional information of objects, commercial digital camera must be examined. For a long time, digital camera has been examined by DLT. Then there must be a high-precision control field. For realizing surveying without control points, a method for self-calibration is proposed.

Self-calibration and algorithm of sample set of piezoresistive pressure sensors

Aiming at piezoresistive pressure sensors, this paper studies simulation of standard pressure by using benchmark current source and self-calibration of the sampling data characteristics. A data fusion algorithm for sample set is presented which transforms a surface problem into a curve fitting and interpolation problem. The simulation result shows that benchmark current source simulating pressure is successful and data fusion algorithm is effective. The maximum measurement error is only 0.098 kPa and maximum relative error is 0.92% at 0-45 kPa and -10-45~C.

Trichromatic Optical Fiber Radiation Thermometer

The study on trichromatic optical fiber radiation thermometers is especially useful for the non-contact accurate temperature measurement of those materials with the emissivities changing dramatically with wavelength.On the basis of the trichromatic thermometry principle,the operation wavelengths of the thermometer are selected properly so as to compensate the emissivity influence on measurement result effectively. Using 1×3 branching fiber coupler and narrow band filter significantly improves the instrument reliability.The instrument is self-calibrated,multi -functional and easy touse due to the embodied microcontroller and some other techniques.