Wrong Position Research Articles

Dynamic Joint Reconstruction of Walls and Targets in Through-the-Wall Radar Imaging

Multipath exploitation with compressive sensing (CS) has been successfully applied in through-the-wall radar imaging (TWRI) given prior knowledge of the room geometry. However, in most practical applications and critical missions, the geometry of the room is not known. In this paper dynamic wall pursuit algorithm is proposed to simultaneously recover the room geometry and image the scene behind the wall. We demonstrate that moving targets increase the wall reconstruction accuracy. The algorithm exploits the fact that wrong wall positions populate the reconstructed image with false targets. It makes use of the moving targets in the scene to increase the certainty of the detected wall positions. Simulated results show the effectiveness of this method even at low SNR values.

Eliminating Daily Shifts, Tattoos, and Skin Marks: Streamlining Isocenter Localization With Treatment Plan Embedded Couch Values for External Beam Radiation Therapy

PurposeThe Radiation Oncology Incident Learning System demonstrated that incorrect or omitted patient shifts during treatment are common near-misses or incidents. This single pediatric hospital quality improvement experience evaluated a markless isocenter localization workflow to improve safety and streamline treatment, obviating the need for daily shifts. Methods and MaterialsPatients undergoing radiation therapy were simulated and treated with indexed immobilization devices. User origins were established at simulation based on a limited set of fixed couch-top references. In treatment planning, shifts from the user origin to the planned isocenter were converted to absolute couch parameters and embedded in the setup field parameters. Thus, the first fraction did not require any shifts. Before kilovoltage imaging, setup verification was often supplemented with surface-guided imaging. After image guidance and final couch adjustments, couch parameters could be reacquired and used for subsequent treatments. No skin marks were used. ResultsOver 3 years, approximately 300 patients were treated with over 5000 treatment fractions using this workflow. There were no wrong-site treatment errors. Approximately a dozen near-miss events related to the daily setup process occurred, largely on the first treatment. Root-cause analysis attributed errors to user origin misidentification, couch parameter miscalculation, incorrect immobilization device use, and immobilization device indexed at the wrong indexing position. Skin marks and tattoos were unnecessary. Continuous quality improvement added additional quality assurance checks, resulting in no near-miss incidents or adverse events in the preceding 12 months. ConclusionWe minimized near-miss incidents by using limited simulation user origins, converting user origin-to-isocenter shifts to absolute couch parameters, and enforcing restrictive tolerance tables to limit delivery parameter changes, coupled with surface guidance and quality assurance tools. This technique can be applied across institutions, age ranges, and tumor types and with or without surface guidance. This workflow has removed a common treatment setup error and the need for skin marks.

Enhanced particle swarm optimization with multi-swarm and multi-velocity for optimizing high-dimensional problems

Traditional particle swarm optimization (PSO) algorithm mainly relies on the history optimal information to guide its optimization. However, when the traditional PSO algorithm searches high-dimensional complex problems, wrong position information of the best particles can easily cause the most of the particles move toward wrong space, so the traditional PSO algorithm is easily trapped into local optimum. To improve the optimization performance of the traditional PSO algorithm, an enhanced particle swarm optimization with multi-swarm and multi-velocity (MMPSO) is proposed. It comprises three particle swarms and three velocity update methods. The information sharing of the multi-swarm with various velocity update methods in the MMPSO can quickly discover more useful global information and local information, helping prevent particles from falling into local optimum and improving optimization precision of the algorithm. The MMPSO is tested on fourteen benchmark functions, and is compared with the other improved PSO algorithms. Comparison results validate the validity and feasibility of the MMPSO to optimize high-dimensional problems.

Channel estimation with Bayesian framework based on compressed sensing algorithm in multimedia transmission system

With the emergence of Wireless multimedia transmission system, the distribution of multimedia contents has now become a reality. To solve the problem of stability in the process of transmission, this paper proposes an improved channel estimation with Bayesian framework based on compressed sensing algorithm in multimedia transmission system. The algorithm uses the sparse characteristics of the channel and can reduce the pilot sequence length under the same conditions. Due to the high complexity of the support agnostic Bayesian matching pursuit algorithm, our algorithm improves the support set, which proposed Expectation Prune Matching Pursuit algorithm in the paper. At each sparsity level of the channel, an expanded support set is given by adding some positions corresponding to the atoms that have a larger inner product value with the current residual signal. Then the best support set is obtained by removing the wrong positions and adopting the idea of Bayesian estimation algorithm in the expanded support set. The estimated channel and the relative probability of the best support set at each sparse level are calculated. Finally, the expectation of the channel is calculated and regarded as the estimation of the channel. Compared with comparison algorithm in the error and bit error rate under different SNR conditions, our proposed algorithm can reduce the computational complexity while maintaining the estimation accuracy.

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OPINION Reactions ShareShare onFacebookTwitterWechatLinked InRedditEmail C&EN, 2018, 96 (31), p 4July 30, 2018Cite this:C&EN 96, 31, 4This illustration appeared with the C&EN article "How to Be Diverse." (Credit: Shutterstock)Figure1of1Letters to the editor Diversity includes weight The article “How to Be Diverse” (C&EN, July 2, page 37) makes the point by illustrating “a diverse and inclusive workplace.” The illustration shows nine people of different genders, races, and ages, including one in a wheelchair and one with a head covering. The drawing is so detailed that it depicts diversity even in terms of height, attire, hairstyle, and facial hair. Yet remarkably, not one of these nine figures is of average or large size—in fact, all are ultraslim even to the point of emaciation.According to the National Institutes of Health, more than two-thirds of all Americans are overweight or obese. Workplace discrimination against overweight and obese people is pervasive in both hiring and promotions, as has been demonstrated in many scientific studies (see, for example, Front. Psychol. 2016, DOI: 10.3389/fpsyg.2016.00647 and references therein). Given these facts, the depiction of “a diverse and inclusive workplace” as one consisting exclusively of ultraskinny fashion-model-like people is especially unfortunate and ironic.Andrew J. Lovinger Arlington, Va. Corrections July 2, page 26: The cover story about synthesizing oligosaccharides found in human milk for use in infant formula incorrectly indicated that a planned clinical trial of a formula by German firm Jennewein Biotechnologie will include two oligosaccharides approved in the U.S. and Europe and three others produced via a proprietary fermentation process. The trial will include one approved and four proprietary oligosaccharides.July 9, page 17: The infographic about volcano chemistry incorrectly stated that pahoehoe lava flows have higher viscosity than aa lava flows. They have lower viscosity.July 23, cover: The 3-D rendering of the structure of cannabidiol depicts an isomer of CBD with the double bond in the cyclohexene ring in the wrong position. The correct 2-D structure appears in the story.

Publisher Correction: Symmetry and magnetism allied

In the version of this News & Views originally published, the placement of the white circle in Fig. 1 was in the wrong position; it should have been over the six-domain vortex. This has now been corrected; see the correction notice for details.

Correction to: Efficient multiobjective optimization employing Gaussian processes, spectral sampling and a genetic algorithm

This note lists changes to the article by Bradford et al.. A number of figures have moved to the wrong positions, while the references in the text still refer to the correct figure, i.e. a number of figures are now in the wrong section, have the wrong position and have the wrong caption.

A robust deterministic approach to node localisation using NLOS signal

Localisation in an urban area is a challenging problem due to the blocking of line-of-sight (LOS) paths and the multipath effect arising out of reflection, scattering and diffraction of signals. We propose a technique to localise sensor nodes based on receiving reflected signals transmitted by anchor nodes. This method can calculate the position of a node by receiving non-line-of-sight (NLOS) signals in presence of range measurement error with better accuracy compared to existing works. We, however, assume that a signal is reflected at most once before reaching a node. While a network is growing, wrong position information may get assigned to some nodes by accident. According to our robust localisation in NLOS, an anchor can detect inconsistency of the wrong position information with the help of three reply signals from a particular node via different paths.

A robust deterministic approach to node localisation using NLOS signal

Localisation in an urban area is a challenging problem due to the blocking of line-of-sight (LOS) paths and the multipath effect arising out of reflection, scattering and diffraction of signals. We propose a technique to localise sensor nodes based on receiving reflected signals transmitted by anchor nodes. This method can calculate the position of a node by receiving non-line-of-sight (NLOS) signals in presence of range measurement error with better accuracy compared to existing works. We, however, assume that a signal is reflected at most once before reaching a node. While a network is growing, wrong position information may get assigned to some nodes by accident. According to our robust localisation in NLOS, an anchor can detect inconsistency of the wrong position information with the help of three reply signals from a particular node via different paths.

Evaluation of a novel, hybrid model (Mumbai EUS II) for stepwise teaching and training in EUS-guided biliary drainage and rendezvous procedures.

Background and aims EUS-guided biliary drainage (EUS-BD) and rendezvous (EUS-RV) are acceptable rescue options for patients with failed endoscopic retrograde cholangiopancreatography (ERCP). However, there are limited training opportunities at most centers owing to low case volumes. The existing models do not replicate the difficulties encountered during EUS-BD. We aimed to develop and validate a model for stepwise learning of EUS-BD and EUS-RV, which replicates the actual EUS-BD procedures. Methods A hybrid model was created utilizing pig esophagus and stomach, with a synthetic duodenum and biliary system. The model was objectively assessed on a grade of 1 – 4 by two experts. Twenty-eight trainees were given initial training with didactic lectures and live procedures. This was followed by hands-on training in EUS-BD and EUS-RV on the hybrid model. Trainees were assessed for objective criteria of technical difficulties. Results Both the experts graded the model as very good or above for all parameters. All trainees could complete the requisite steps of EUS-BD and EUS-RV in a mean time of 11 minutes (8 – 18 minutes). Thirty-six technical difficulties were noted during the training (wrong scope position, 13; incorrect duct puncture, 12; guidewire related problems, 11). Technical difficulties peaked for EUS-RV, followed by hepaticogastrostomy (HGS) and choledochoduodenostomy (CDS) (20, 9, and 7, P = 0.001). At 10 days follow-up, nine of 28 trainees had successfully performed three EUS-RV and seven EUS-BD procedures independently. Conclusions The Mumbai EUS II hybrid model replicates situations encountered during EUS-RV and EUS-BD. Stepwise mentoring improves the chances of success in EUS-RV and EUS-BD procedures.

Erratum: controlled‐source electromagnetic monitoring of reservoir oil‐saturation using a novel borehole‐to‐surface configuration

Erratum: controlled‐source electromagnetic monitoring of reservoir oil‐saturation using a novel borehole‐to‐surface configuration

Accurate guide wire of lag screw placement in the intertrochanteric fractures: a technical note.

Cephalomedullary fixations are commonly used in the treatment of intertrochanteric fractures. In clinical practice, one of the difficulties is when we exit the guide wire in a wrong position of femoral neck and insert near the hole again, the guide wire often flow into the previous track. This study develops a surgical technique to direct the guide wire to slip away the previous track and slip into a right position. When guide wire is exited to the cortex of femoral, we let the wire in and out at the cortical layer for several times to enlarge the entry hole. After that, electric drill is inverted, rubbed and entered slowly at a right angle. When guide wire encountered new resistance, the electric drill is turned back instantly. This technique can help trauma and orthopedic surgeons to obtain precision placement of the lag screw after the first try is failed.

Graph analytical study of the possibility of prevention and treatment of dislocation of the hip joint head because of the incorrect position of its components

Objective: to determine the mechanisms of the disloca­tion of the head of the hip joint endoprosthesis on the basis of the graphoanalytic modeling method and to correct the wrong position of its components. Methods: graphical-analytical model­ing. Results: it has been established that there are two mecha­nisms of dislocation of the head of the hip joint endoprosthesis, related to its size and compliance with the angles of inclination and anteversion of the cup and antithesis of the endoprosthesis stem. The loss of contact area can also occur due to the wear of the friction pair. The most stable are endoprostheses with large-diameter heads, which allow increasing the shoul­der strength, which counteracts the disabling effect. As a mea­sure to prevent dislocations, you can use liners with a visor that prevent the dislocation of the head or neck of the endo­prosthesis of a reduced diameter. If the endoprosthesis cup has too much angle of inclination or insufficient cup anteversion and/or antithesis of the stem, but there is a stable anchorage, a liner with a visor can also be used. The angle of the movement of the endoprosthesis head due to the use of a liner with a vi­sor decreases with increasing diameter of the heads, which also indicates the advantage of using them to prevent dislocation of the endoprosthesis. Conclusions: in the hip joint endopros­thetics for the prevention of head dislocation, it is important to observe the correct position of its components. If it is not pos­sible to install the components of the endoprosthesis within the limits that prevent the appearance of dislocation of the head, and also for the purpose of its elimination, it is advisable to use liners with a visor in combination with large diameter heads. The choice of the neck of the endoprosthesis with a reduced di­ameter reduces the risk of its dislocations.

Signaling game based strategy for secure positioning in wireless sensor networks

Sensor localization is demanded by wireless sensor networks, since the collected sensor data are meaningless if the position of the generating sensor is not available. The traditional approach of using GPS for location determination is not suitable for sensor networks, due to the increased costs and resource usage. For this reason, sensors exchange Radio Frequency messages, so as to measure their respective distances and determine their locations by means of multilateral triangulation with sensors of known positions, called anchors. Such an approach, however, is particularly vulnerable to several kinds of attacks aiming at causing wrong position estimations with a malicious intention. Such attacks can be tolerated with proper countermeasures, belonging to the so called secure localization, but this is achieved at the expenses of high costs in terms of exchanged messages and exhausted sensor resources, such as the battery. For these reasons, it is crucial to use the secure localization only when needed in order to extend considerably the life span of the sensors. Therefore, we propose to model the interaction of an anchor with a sensor as a signaling game, and to use such a formalization to discipline the use of secure positioning methods based on the received messages from the anchors. We have proved with simulations that such a solution is more efficient than a naive one of always applying secure localization.

Desain Sistem Pendeteksi untuk Citra Base Sub-assembly dengan Algoritma Backpropagation

Object identification technique using machine vision has been implemented in industrial of electronic manufacturers for years. This technique is commonly used for reject detection (for disqualified product based on existing standard) or defect detection. This research aims to build a reject detector of sub-assembly condition which is differed by two conditions that are missing screw and wrong position screw using neural network backpropagation. The image taken using camera will be converted into grayscale before it is processed in backpropagation methods to generate a weight value. The experiment result shows that the network architecture with two layers has the most excellent accuracy level. Using learning rate of 0.5, target error 0.015%, and the number of node 1 of 100 and node 2 of 50, the successive rate for sub-assembly detection in right condition reached 99.02% while no error occurs in detecting the wrong condition of Sub-assembly (missing screw and wrong position screw).

Corrigendum: Re-evaluating the Malawian Farm Input Subsidy Programme.

Nature Plants 3, 17013 (2017); published online 6 March 2017; corrected 13 March 2017. In the version of this Article originally published, the map in Fig. 1 showed Lake Chiuta in the wrong position. Lake Chiuta is actually situated along the southeast border of Malawi. This has now been corrected in all versions of the Article.

The Impact of Common Inhaler Errors on Drug Delivery: Investigating Critical Errors with a Dry Powder Inhaler.

Researchers, using checklists, have identified that 30%-90% of patients make errors in inhaler use. It is not certain whether these errors affect the delivery of medication. We have developed an electronic monitor (INCA™) that records audio each time an inhaler is used, providing objective information on inhaler technique. The aim of this study was to assess the effect that correctly identified inhaler errors, with the INCA device, have on drug delivery. This was a prospective study of healthy volunteers using a salbutamol Diskus™. The inclusion criteria allowed for the recruitment of healthy participants who were nonfrequent users of Salbutamol. Each participant was assigned to one control "phase" first and two/three subsequent error "phases." Each phase consisted of six doses of the drug taken 6 hours apart, and the participants' blood was drawn before and 25 minutes after doses one and six. This allowed us to sample their trough and peak serum salbutamol levels. Fourteen healthy volunteers were studied. The inhaler technique errors simulated in this study included exhaling into the device after drug priming but before inhalation, low inspiratory flow, multiple inhalations, low breath hold, missed doses, and wrong inhaler position. Only the exhalation error, low inspiratory flow, and missed doses led to a significant reduction in serum salbutamol levels. After six doses of the exhalation error, there was a 62% reduction in peak salbutamol levels. Low inspiratory flow led to a 52% reduction in peak salbutamol levels and a 78% reduction in trough levels. Missed doses led to a 37% reduction in trough salbutamol levels. These findings confirm that technique errors affect drug delivery. Furthermore, we were able to identify that the most critical technique errors with the Diskus inhaler are exhalation into the device before inhalation, poor inspiratory flow, and missing doses.

Probabilistic multi-person localisation and tracking in image sequences

The localisation and tracking of persons in image sequences in commonly guided by recursive filters. Especially in a multi-object tracking environment, where mutual occlusions are inherent, the predictive model is prone to drift away from the actual target position when not taking context into account. Further, if the image-based observations are imprecise, the trajectory is prone to be updated towards a wrong position. In this work we address both these problems by using a new predictive model on the basis of Gaussian Process Regression, and by using generic object detection, as well as instance-specific classification, for refined localisation. The predictive model takes into account the motion of every tracked pedestrian in the scene and the prediction is executed with respect to the velocities of neighbouring persons. In contrast to existing methods our approach uses a Dynamic Bayesian Network in which the state vector of a recursive Bayes filter, as well as the location of the tracked object in the image, are modelled as unknowns. This allows the detection to be corrected before it is incorporated into the recursive filter. Our method is evaluated on a publicly available benchmark dataset and outperforms related methods in terms of geometric precision and tracking accuracy.

Evaluation of a novel, easily reproducible, hybrid model (mumbai endoscopic ultrasound ii) for teaching and training endoscopic ultrasound-guided biliary drainage and rendezvous procedure

Background:Endoscopic ultrasound-guided biliary drainage (EUS-BD) is an acceptable rescue option in patients with failed endoscopic retrograde cholangiopancreatography (ERCP). EUS-guided biliary rendezvous (EUS-RV) allows transpapillary drainage in patients with failed ERCP and approachable papilla. There are limited learning and training opportunities for EUS-guided biliary drainage (EUS-BD) and EUS-RV at most centers due to low case volumes. An effective and easily reproducible model is desirableObjectives:To develop and validate a model for stepwise learning of EUS-BD and EUS-RV.Methods:A hybrid model was created utilizing pig esophagus and stomach, synthetic duodenum, and synthetic biliary system with distal stricture. Twenty-eight trainees were given hands-on training in EUS-BD and EUS-RV procedures. They were assessed for objective criteria (needle puncture, contrast injection, and guidewire manipulation across hilar bifurcation, stricture, and papilla, followed by guidewire retrieval with snare into the duodenoscope channel and stent placement).Results:All trainees could complete the requisite steps of EUS-BD and EUS-RV in a mean time of 11 min (8–18 min). Twenty trainees had technical issues during the procedures, which were corrected by the expert (wrong scope position 4, incorrect duct puncture 8, guidewire manipulation 8). At 10 days follow-up, 9 of 28 trainees had successfully performed three EUS-RV and seven EUS-BD procedures independently at their respective institutes.Conclusions:The Mumbai EUS II hybrid model gives real-life feel of situations encountered during EUS-RV and EUS-BD.

Correlation between working positions and lactic acid levels with musculoskeletal complaints among dentists

Background: Musculoskeletal complaints have been common for dentists since their body is unknowingly often in inappropriate positions when caring for patients. For example, they bend towards patients, suddenly move, and then rotate from one side to another. The repetitive movements are done in long term. High activities and sufficient recovery time can cause a buildup of lactic acid in their blood leading to obstruction of the energy intake from the aerobic system in their muscle cells, resulting in fatigue. As a result, such conditions trigger decreased muscle performances. Purpose: This study aimed to determine the correlation between working positions and lactic acid levels with the risk of musculoskeletal disorders among dentists at Public Health Centers in Surabaya. Method: This research was an analytical observational research using cross sectional approach. Sampling technique used in this research was cluster random sampling with nineteen samples. To evaluate the working positions of those samples, a rapid entire body assessment (REBA) method was used. Meanwhile, to observe the musculoskeletal disorders of those samples, a Nordic body map was used. Data obtained then were analyzed using Pearson correlation test with a significance level (p<0.05). Result: Results of data analysis using the Pearson correlation test showed that the significance value obtained was 0.036. It indicates that there was a correlation between the working positions and the lactic acid levels with the musculoskeletal disorders in those dentists. The results of the Pearson correlation test also revealed that there was a correlation between the working positions and the lactic acid levels among those dentists with a significance value of 0.025. Conclusion: It may be concluded that the wrong body positions during working can increase lactic acid level in the body of dentists. The increased level of lactic acid then can affect their muscles, leading to the high risk of musculoskeletal disorders.