A SINS/SAR/GPS Fusion Positioning System Based on Sensor Credibility Evaluations

A reliable framework for SINS/SAR/GPS integrated positioning systems is proposed for the case that sensors are in critical environments. Credibility is used to describe the difference between the true error and the initial setting standard deviation. Credibility evaluation methods for inertial measurement unit (IMU), synthetic aperture radar (SAR), and global positioning system (GPS) are presented. In particular, IMU credibility is modeled by noises and constant drifts that are accumulated with time in a strapdown inertial navigation system (SINS). The quality of the SAR image decides the credibility of positioning based on SAR image matching. In addition, a cumulative residual chi-square test is used to evaluate GPS credibility. An extended Kalman filter based on a sensor credibility evaluation is introduced to integrate the measurements. The measurement of a sensor is either discarded when its credibility value is below a threshold or the variance matrix for the estimated state is otherwise adjusted. Simulations show that the final fusion positioning accuracy with credibility evaluation can be improved by 1–2 times compared to that without evaluation. In addition, the derived standard deviation correctly indicates the value of the position error with credibility evaluation. Moreover, the experiments on an unmanned ground vehicle partially verify the proposed evaluation method of GPS and the fusion framework in the actual environment.

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Indoor Localization of Quadcopters in Industrial Environment

Advances in Transdisciplinary Engineering - SPS2020 ◽

10.3233/atde200183 ◽

2020 ◽

Author(s):

Péter Troll ◽

Károly Szipka ◽

Andreas Archenti

Keyword(s):

Computer Vision ◽

Material Handling ◽

Evaluation Method ◽

Indoor Localization ◽

Research Work ◽

Fine Tuning ◽

Measurement Unit ◽

Positioning System ◽

Estimation System ◽

Slam Algorithm

The research work in this paper was carried out to reach advanced positioning capabilities of unmanned aerial vehicles (UAVs) for indoor applications. The paper includes the design of a quadcopter and the implementation of a control system with the capability to position the quadcopter indoor using onboard visual pose estimation system, without the help of GPS. The project also covered the design and implementation of quadcopter hardware and the control software. The developed hardware enables the quadcopter to raise at least 0.5kg additional payload. The system was developed on a Raspberry single-board computer in combination with a PixHawk flight controller. OpenCV library was used to implement the necessary computer vision. The Open-source software-based solution was developed in the Robotic Operating System (ROS) environment, which performs sensor reading and communication with the flight controller while recording data about its operation and transmits those to the user interface. For the vision-based position estimation, pre-positioned printed markers were used. The markers were generated by ArUco coding, which exactly defines the current position and orientation of the quadcopter, with the help of computer vision. The resulting data was processed in the ROS environment. LiDAR with Hector SLAM algorithm was used to map the objects around the quadcopter. The project also deals with the necessary camera calibration. The fusion of signals from the camera and from the IMU (Inertial Measurement Unit) was achieved by using Extended Kalman Filter (EKF). The evaluation of the completed positioning system was performed with an OptiTrack optical-based external multi-camera measurement system. The introduced evaluation method has enough precision to be used to investigate the enhancement of positioning performance of quadcopters, as well as fine-tuning the parameters of the used controller and filtering approach. The payload capacity allows autonomous material handling indoors. Based on the experiments, the system has an accurate positioning system to be suitable for industrial application.

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Hubungan Variabilitas Glukosa 72 Jam Pertama Perawatan ICU dengan Mortalitas ICU pada Pasien Kritis

Jurnal Penyakit Dalam Indonesia ◽

10.7454/jpdi.v3i1.4 ◽

2017 ◽

Vol 3 (1) ◽

pp. 14 ◽

Cited By ~ 1

Author(s):

Elizabeth Yasmine ◽

Arif Mansjoer ◽

Dyah Purnamasari ◽

Hamzah Shatri

Keyword(s):

Logistic Regression ◽

Standard Deviation ◽

Glucose Variability ◽

Lower Quartile ◽

Icu Mortality ◽

Chi Square ◽

High Care ◽

Mortality Proportion ◽

Chi Square Test ◽

The Difference

Pendahuluan. Hiperglikemia saat perawatan merupakan faktor risiko yang dapat ditatalaksana dengan optimal untuk menurunkan mortalitas. Penelitian hubungan variabilitas glukosa terhadap mortalitas telah diteliti, namun menggunakan indikator yang bervariasi. Penelitian ini dilakukan untuk mengkaji hubungan variabilitas glukosa yaitu rerata perubahan glukosa absolut (mean absolute glucose change, MAG) dan simpang baku glukosa terhadap mortalitas pasien kritis.Metode. Studi kohort retrospektif dilakukan pada 280 pasien yang dirawat di intensive care unit (ICU) dan high care unit (HCU) Rumah Sakit dr. Cipto Mangunkusumo (RSCM) Jakarta periode Januari 2012-Agustus 2013. Variabel MAG dan simpang baku glukosa dibagi menjadi 4 kuartil. Analisis hubungan antara MAG dan simpang baku glukosa dengan mortalitas dilakukan dengan uji chi Square. Untuk mengeluarkan faktor perancu (skor MSOFA, indeks komorbiditas Charlson,hipoglikemia, dan hiperglikemia) dilakukan uji regresi logistik.Hasil. Nilai median MAG dan simpang baku gukosa masing-masing adalah 3,3 mg/dL/jam dan 38,3 mg/dL. Proporsi mortalitas yang lebih tinggi didapatkan pada kuartil atas MAG dan simpang baku glukosa dibandingkan kuartil bawah. Berdasarkan uji chi square, didapatkan hasil OR MAG kuartil atas terhadap mortalitas OR 4,26 (IK 95% 1,98-9,15) dan OR simpang baku glukosa kuartil atas terhadap mortalitas OR 2,78 (IK 95% 1,35-5,71). Setelah dilakukan uji regresi logistik didapatkan fully adjusted OR 3,34 (IK 95% 1,08-10,31) untuk MAG dan 0,90 (IK 95% 0,28-2,88) untuk simpang baku glukosa.Simpulan. Proporsi mortalitas MAG kuartil atas (>8,1 mg/dL/jam) lebih tinggi daripada kuartil bawah (<1,3 mg/dL/jam). Proporsi mortalitas simpang baku glukosa kuartil atas (>59 mg/dL) lebih tinggi daripada kuartil bawah (<22,7 mg/dL). Namun demikian, hasil tersebut tidak bermakna secara statistik.Kata kunci: mortalitas, rerata perubahan glukosa absolut, simpang baku glukosa, variabilitas glukosa Association of Glucose Variability in the First 72 Hours of ICU Care with ICU Mortality in Critically-III PatientsIntroduction. Hyperglycemia during hospitalization is a risk factor that can be managed in order to reduce mortality. Inspite of hyperglycemia, glucose variability also brings negative outcome to cells. Studies about glucose variability effect to mortality had been studied using many variables of glucose variability. Methods. Retrospective cohort study is done to 280 critical ill patient in ICU and HCU in Cipto Mangunkusumo Hospital who admitted to critical care between January 2012-August 2013. MAG change and glucose standard deviation are divided into 4 quartiles. Relationship between MAG change and glucose standard deviation are analyzed using Chi Square test. To control the confounders (MSOFA score, Charlson comorbidities index, hypoglycemia, and hyperglycemia), logistic regression is done.Results. Median of MAG change is 3.3 mg/dL/hour and median of glucose standard deviation is 37.63 mg/dL. Mortality proportion is higher in upper quartile of MAG change and glucose standard deviation compared to lower quartile. OR of upper quartile MAG change to ICU mortality is OR 4.26 (95% CI 1.98-9.15) and OR of upper quartile glucose standard deviation to ICU mortality is OR 2.78 (95% CI 1.35-5.71). These results are adjusted to MSOFA score, hypoglycemia, and hyperglycemia. In logistic regression test, fully adjusted OR are 3.34 (95% CI 1.08-10.31) and 0.90 (95% CI 0.28-2.88) for MAG change and glucose standard deviation, respectively. Conclusions. Mortality proportion of upper quartile of MAG change (>8.1 mg/dL/hour) is higher than lower quartile (<1.3 mg/dL). Mortality proportion of upper quartile glucose standard deviation (>59 mg/dL) is higher than lower quartile(<22.7 mg/dL), but the difference is not statistically significant. Keywords: glucose standard deviation, glucose variability, mean absolute glucose change, mortality

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(P2-45) Impact of Educational Intervention on Knowledge Regarding Disaster Management Among Nurses Working in Nepal

Prehospital and Disaster Medicine ◽

10.1017/s1049023x11004894 ◽

2011 ◽

Vol 26 (S1) ◽

pp. s150-s150

Author(s):

G.N. Mandal

Keyword(s):

Standard Deviation ◽

Disaster Management ◽

Educational Intervention ◽

Sampling Technique ◽

Chi Square ◽

Before And After ◽

Post Test ◽

Awareness Programs ◽

The Difference ◽

Level Of Significance

ObjectivesThe purpose of this study was to find the change in knowledge regarding disaster management among nurses after educational intervention.MethodsOne group pretest and post test design was adopted for the study. The study was carried out in B.P. Koirala Institute of Health Sciences, Nepal. Forty Nurses were selected from emergency, orthopedics, medicine, and surgical ward by using non-probability convenience sampling technique. A self-administered semi-structured questionnaire was used to collect the data. Data was collected before and after the educational intervention. The collected data were analyzed using descriptive statistics (frequency, percentage, mean, standard deviation) and inferential statistics (Chi-square and Z test) were used to identify the difference in knowledge between pre-test and post-test, at 0.05 level of significance.ResultsStudy findings revealed that in the pre-test, grand mean of the means of the nurses' knowledge on different aspects of disaster management as a whole was 2.39 with the standard deviation of 0.87. Similarly the grand mean of means of knowledge on different aspects of disaster management was 3.2 with the standard deviation of 0.47 in the post-test. The difference between pre-test and post-test in respondents' knowledge in different aspects of disaster management as a whole was calculated by using “Z” test (p < 0.05) The result showed that the educational intervention was effective in bringing changes in knowledge in all aspects of disaster management.ConclusionsStudy findings revealed that there was significant increase in knowledge in the post-test after the educational intervention. Therefore, it can be concluded that education plays an important role in increasing awareness. It is recommended that awareness programs on disaster management should be carried out periodically as in-service education.

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Improved Position Accuracy of Foot-Mounted Inertial Sensor by Discrete Corrections from Vision-Based Fiducial Marker Tracking

Sensors ◽

10.3390/s20185031 ◽

2020 ◽

Vol 20 (18) ◽

pp. 5031

Author(s):

Humayun Khan ◽

Adrian Clark ◽

Graeme Woodward ◽

Robert W. Lindeman

Keyword(s):

Inertial Sensor ◽

Vision System ◽

Tracking System ◽

Indoor Positioning ◽

Fiducial Marker ◽

Measurement Unit ◽

Positioning System ◽

Positioning Systems ◽

Marker Tracking ◽

Training Exercises

In this paper, we present a novel pedestrian indoor positioning system that uses sensor fusion between a foot-mounted inertial measurement unit (IMU) and a vision-based fiducial marker tracking system. The goal is to provide an after-action review for first responders during training exercises. The main contribution of this work comes from the observation that different walking types (e.g., forward walking, sideways walking, backward walking) lead to different levels of position and heading error. Our approach takes this into account when accumulating the error, thereby leading to more-accurate estimations. Through experimentation, we show the variation in error accumulation and the improvement in accuracy alter when and how often to activate the camera tracking system, leading to better balance between accuracy and power consumption overall. The IMU and vision-based systems are loosely coupled using an extended Kalman filter (EKF) to ensure accurate and unobstructed positioning computation. The motion model of the EKF is derived from the foot-mounted IMU data and the measurement model from the vision system. Existing indoor positioning systems for training exercises require extensive active infrastructure installation, which is not viable for exercises taking place in a remote area. With the use of passive infrastructure (i.e., fiducial markers), the positioning system can accurately track user position over a longer duration of time and can be easily integrated into the environment. We evaluated our system on an indoor trajectory of 250 m. Results show that even with discrete corrections, near a meter level of accuracy can be achieved. Our proposed system attains the positioning accuracy of 0.55 m for a forward walk, 1.05 m for a backward walk, and 1.68 m for a sideways walk with a 90% confidence level.

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Home ownership in Saudi Arabia: Spatial Dimensions

10.31124/advance.7106306.v1 ◽

2018 ◽

Author(s):

Asharaf Abdul Salam

Keyword(s):

Saudi Arabia ◽

Standard Deviation ◽

Detailed Analysis ◽

Statistical Methods ◽

Home Ownership ◽

Ownership Type ◽

Chi Square ◽

Spatial Dimensions ◽

One Way Anova

This paper undertakes a detailed analysis of 2010 Census Population and Household Tables (Final), to assess governorate wise variations in home ownership, type of living accommodations and housing infrastructure - material used for construction, electricity, water and sewage facilities. The data published by the Ministry of Economics and Planning in its “Population and Housing, 2010 Census” analyzed in detail using SPSS20, applying statistical methods such as, cross tabulations and chi-square; mean and standard deviation; and One-Way ANOVA. Governorates classified into small, medium and large, according to the number of Saudi persons, have been analyzed across 13 regions quantifying homeownership status. Further governorates are classified according to the percentage of owning homes in order to analyze the type of living accommodations, built up material of housing, source of electricity, water and sewage facilities.

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Home ownership in Saudi Arabia: Spatial Dimensions

10.31124/advance.7106306 ◽

2018 ◽

Author(s):

Asharaf Abdul Salam

Keyword(s):

Saudi Arabia ◽

Standard Deviation ◽

Detailed Analysis ◽

Statistical Methods ◽

Home Ownership ◽

Ownership Type ◽

Chi Square ◽

Spatial Dimensions ◽

One Way Anova

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Difference in taste of Japanese sugars

Sugar Industry ◽

10.36961/si16850 ◽

2015 ◽

pp. 624-627

Author(s):

Kiyoaki Miyasaka ◽

Mizuki Mutsuura ◽

Kohei Miyazaki ◽

Masahiro Okuno ◽

Masami Mizu ◽

...

Keyword(s):

Sensory Evaluation ◽

Evaluation Method ◽

New Products ◽

Processed Foods ◽

White Crystal ◽

Sensing System ◽

Light Brown Crystal ◽

Brown Crystal ◽

Home Cooking ◽

The Difference

Japanese traditional cuisine “Washoku” was registered as one of the intangible cultural heritages in December 2013. “Washoku” contains and requires large amount of sugar, therefore, sugar is an important seasoning in taste. Japanese have been using many kinds of sugar such as Granulated sugar, White soft sugar, Brown soft sugar, White crystal sugar and Light brown crystal sugar according to application, for both home cooking and processed foods. Mitsui Sugar is focusing on the difference in taste of sugars to develop new attractive sugar products. With a sensory evaluation method, trained panelists could recognize the difference between these sugars though it is quite difficult to explain. Therefore one attempte624-627d to detect the taste difference in these sugars by using a taste sensing system. The system comes with a human taste model membrane and can analyze the density and balance of several tastes such as sweetness, bitterness, umami** and saltiness. The accuracy of the sensing system was evaluated by comparing the results against the sensory evaluation method by trained panelists. The sensing system was able to detect the difference in taste of Japanese sugars, and the results from the sensing system seemed to match with the ones from the sensory evaluation method. The results were plotted on a taste map. This map will be helpful not only in showing the difference between the sugars, but also in explaining the characteristics of the new products.

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High-Precision RTT-Based Indoor Positioning System Using RCDN and RPN

Sensors ◽

10.3390/s21113701 ◽

2021 ◽

Vol 21 (11) ◽

pp. 3701

Author(s):

Ju-Hyeon Seong ◽

Soo-Hwan Lee ◽

Won-Yeol Kim ◽

Dong-Hoan Seo

Keyword(s):

High Precision ◽

Distance Estimation ◽

Sampling Period ◽

Multipath Fading ◽

Indoor Positioning ◽

Positioning System ◽

Positioning Systems ◽

Positioning Errors ◽

Location Determination ◽

Indoor Positioning System

Wi-Fi round-trip timing (RTT) was applied to indoor positioning systems based on distance estimation. RTT has a higher reception instability than the received signal strength indicator (RSSI)-based fingerprint in non-line-of-sight (NLOS) environments with many obstacles, resulting in large positioning errors due to multipath fading. To solve these problems, in this paper, we propose high-precision RTT-based indoor positioning system using an RTT compensation distance network (RCDN) and a region proposal network (RPN). The proposed method consists of a CNN-based RCDN for improving the prediction accuracy and learning rate of the received distances and a recurrent neural network-based RPN for real-time positioning, implemented in an end-to-end manner. The proposed RCDN collects and corrects a stable and reliable distance prediction value from each RTT transmitter by applying a scanning step to increase the reception rate of the TOF-based RTT with unstable reception. In addition, the user location is derived using the fingerprint-based location determination method through the RPN in which division processing is applied to the distances of the RTT corrected in the RCDN using the characteristics of the fast-sampling period.

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Consistency of the Empirical Distributions of Navigation Positioning System Errors with Theoretical Distributions—Comparative Analysis of the DGPS and EGNOS Systems in the Years 2006 and 2014

Sensors ◽

10.3390/s21010031 ◽

2020 ◽

Vol 21 (1) ◽

pp. 31

Author(s):

Mariusz Specht

Keyword(s):

Normal Distribution ◽

Root Mean Square ◽

Statistical Tests ◽

Position Error ◽

Positioning System ◽

Navigation Systems ◽

Mean Square ◽

Positioning Systems ◽

Position Errors ◽

System Errors

Positioning systems are used to determine position coordinates in navigation (air, land and marine). The accuracy of an object’s position is described by the position error and a statistical analysis can determine its measures, which usually include: Root Mean Square (RMS), twice the Distance Root Mean Square (2DRMS), Circular Error Probable (CEP) and Spherical Probable Error (SEP). It is commonly assumed in navigation that position errors are random and that their distribution are consistent with the normal distribution. This assumption is based on the popularity of the Gauss distribution in science, the simplicity of calculating RMS values for 68% and 95% probabilities, as well as the intuitive perception of randomness in the statistics which this distribution reflects. It should be noted, however, that the necessary conditions for a random variable to be normally distributed include the independence of measurements and identical conditions of their realisation, which is not the case in the iterative method of determining successive positions, the filtration of coordinates or the dependence of the position error on meteorological conditions. In the preface to this publication, examples are provided which indicate that position errors in some navigation systems may not be consistent with the normal distribution. The subsequent section describes basic statistical tests for assessing the fit between the empirical and theoretical distributions (Anderson-Darling, chi-square and Kolmogorov-Smirnov). Next, statistical tests of the position error distributions of very long Differential Global Positioning System (DGPS) and European Geostationary Navigation Overlay Service (EGNOS) campaigns from different years (2006 and 2014) were performed with the number of measurements per session being 900’000 fixes. In addition, the paper discusses selected statistical distributions that fit the empirical measurement results better than the normal distribution. Research has shown that normal distribution is not the optimal statistical distribution to describe position errors of navigation systems. The distributions that describe navigation positioning system errors more accurately include: beta, gamma, logistic and lognormal distributions.

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Sensing Framework for the Internet of Actors in the Value Co-Creation Process with a Beacon-Attachable Indoor Positioning System

Sensors ◽

10.3390/s21010083 ◽

2020 ◽

Vol 21 (1) ◽

pp. 83

Author(s):

Keiichi Zempo ◽

Taiga Arai ◽

Takuya Aoki ◽

Yukihiko Okada

Keyword(s):

Radio Wave ◽

Indoor Positioning ◽

Measurement Range ◽

Pulse Interval ◽

Retail Stores ◽

Positioning System ◽

Radio Waves ◽

Positioning Systems ◽

Environment Recognition ◽

Indoor Positioning System

To evaluate and improve the value of a service, it is important to measure not only the outcomes, but also the process of the service. Value co-creation (VCC) is not limited to outcomes, especially in interpersonal services based on interactions between actors. In this paper, a sensing framework for a VCC process in retail stores is proposed by improving an environment recognition based indoor positioning system with high positioning performance in a metal shelf environment. The conventional indoor positioning systems use radio waves; therefore, errors are caused by reflection, absorption, and interference from metal shelves. An improvement in positioning performance was achieved in the proposed method by using an IR (infrared) slit and IR light, which avoids such errors. The system was designed to recognize many and unspecified people based on the environment recognition method that the receivers had installed, in the service environment. In addition, sensor networking was also conducted by adding a function to transmit payload and identification simultaneously to the beacons that were attached to positioning objects. The effectiveness of the proposed method was verified by installing it not only in an experimental environment with ideal conditions, but posteriorly, the system was tested in real conditions, in a retail store. In our experimental setup, in a comparison with equal element numbers, positioning identification was possible within an error of 96.2 mm in a static environment in contrast to the radio wave based method where an average positioning error of approximately 648 mm was measured using the radio wave based method (Bluetooth low-energy fingerprinting technique). Moreover, when multiple beacons were used simultaneously in our system within the measurement range of one receiver, the appropriate setting of the pulse interval and jitter rate was implemented by simulation. Additionally, it was confirmed that, in a real scenario, it is possible to measure the changes in movement and positional relationships between people. This result shows the feasibility of measuring and evaluating the VCC process in retail stores, although it was difficult to measure the interaction between actors.

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