A Statistical Framework for Evaluating the Effectiveness of Vegetation Management in Reducing Power Outages Caused during Storms in Distribution Networks

This paper develops a statistical framework to analyze the effectiveness of vegetation management at reducing power outages during storms of varying severity levels. The framework was applied on the Eversource Energy distribution grid in Connecticut, USA based on 173 rain and wind events from 2005–2020, including Hurricane Irene, Hurricane Sandy, and Tropical Storm Isaias. The data were binned by storm severity (high/low) and vegetation management levels, where a maximum applicable length of vegetation management for each circuit was determined, and the data were divided into four bins based on the actual length of vegetation management performed divided by the maximum applicable value (0–25%, 25–50%, 50–75%, and 75–100%). Then, weather and overhead line length normalized outage statistics were taken for each group. The statistics were used to determine the effectiveness of vegetation management and its dependence on storm severity. The results demonstrate a higher reduction in damages for lower-severity storms, with a reduction in normalized outages between 45.8% and 63.8%. For high-severity events, there is a large increase in effectiveness between the highest level of vegetation management and the two lower levels, with 75–100% vegetation management leading to a 37.3% reduction in trouble spots. Yet, when evaluating system reliability, it is important to look at all storms combined, and the results of this study provide useful information on total annual trouble spots and allow for analysis of how various vegetation management scenarios would impact trouble spots in the electric grid. This framework can also be used to better understand how more rigorous vegetation management standards (applying ETT) help reduce outages at an individual event level. In future work, a similar framework may be used to evaluate other resilience improvements.

Application of magneto-optical method for detection of material structure changes

The possibilities of magneto-optical sensors to control the damage of ferromagnetic and para-magnetic materials and products are considered. In the introduction it is shown that modern magneto-optical materials used in creating sensors have a high sensitivity and spatial resolution. So, on their basis it is possible to develop sensitive and informative means of non-destructive testing for a wide range of applications. For example, it is used to detect microcracks, corrosion damage, degradation changes in the material structure, surface deformations, and subsurface defects. The method ability to detect appearance of magnetic phases in paramagnetic materials, that are precursors of fracture, is of a special importance. The advantage of magneto-optic sensors is a large observation area and high spatial resolution. Resolution of the sensor is determined by the period and size of the domain structure, which averages 13...50 micrometres. High sensitivity of the sensor is due to a small saturation field of the magneto-optic material from 0.1 mT to 0.7 mT. In addition, these parameters are controlled by changing the temperature of the sensor, direction and intensity of the magnetic field. In this paper an optical scheme based on magneto-optical garnet film for visualization of fatigue cracks, which are formed in compact samples during their experimental investigation on fatigue failure is described. The developed scheme allowed us to visualize and fix position of the crack and determine its actual length, considering the closed part of the crack. A further direction of research will be to increase the sensitivity of the developed scheme and reduce the noise of magneto-optical images to identify the initial stages of the degradation process of ferromagnetic and paramagnetic materials and products.

Application of ImageJ Software in the assessment of flowering Intensity and growth Vigor of pear Trees

The study evaluated the possibility of using the image acquisition and processing method with ImageJ software for estimating growth vigor and flowering intensity of ‘Conference’ pear trees. For assessing flowering intensity, manual counting of flower clusters and taking of photographs of the trees were conducted at full bloom. Tree vigor was estimated by manually measuring the total length of the central leader and shoots of individual trees. The trees were photographed from the same distance using a hand-held camera. The calibration model for assessing the vigor or flowering of trees by image analysis was based on measurements and photographs taken for nine selected trees differing in the total length of shoots or in the number of flower clusters. Then, a quality assessment of the model was carried out on 26 nonselected trees. Image processing was performed using ImageJ software. High regression coefficients were obtained between the surface area of petals measured on the photographs and the number of inflorescences counted (r2 = 0.98); however, observations carried out in the following year indicate the need for individual calibration of estimation models in each evaluation season. Subsequently, the quality of estimating the flowering intensity of pear trees was assessed using a previously determined calibration model. Mean absolute percentage error (MAPE) values ranged from 14.0% to 21.8%, depending on the measurement time. In the assessment of tree growth vigor, a high correlation (r2 = 0.98) was also obtained between the actual length of shoots measured individually for each tree and the values obtained by analyzing the photographic image, where the MAPE error was 12.9%.

A new measure to quantify sedentary behavior using accelerometer data: Application to the Hispanic Community Health Study/Study of Latinos

Availability of accelerometer data has made it possible to objectively and continuously monitor sedentary behavior. Various summaries of the extensive accelerometer data have been used to understand the relationship between sedentary behavior and health. However, the widely used summary measures on sedentary bouts, average bout length or its derivatives, fail to reveal patterns of accumulated sedentary behavior over time. Studies have suggested that prolonged uninterrupted sedentary behavior can be an important metric that is related to health states. Yet existing measures to capture the prolonged sedentary patterns either rely on parametric assumptions on the underlying distribution of sedentary bout length or have to categorize sedentary bout length into somewhat arbitrary categories. Gini index was also used; however, it only measures the variability in bout lengths but not the actual length. To overcome these limitations, we proposed a non-parametric weighted survival function to characterize uninterrupted sedentary behavior over time in a continuous fashion and used the area under the survival curve as a new summary measure to quantify sedentary behavior. We showed that this measure is a weighted average of bout length and contains the information on both the mean and variability of bout lengths. We demonstrated in the simulation studies that the proposed measure could better identify prolonged uninterrupted sedentary behavior and predict health outcomes. We applied this new measure and existing sedentary measures to data from the Hispanic Community Health Study/Study of Latinos to examine the association between sedentary behavior and overweight/obesity.

Analysis of Influencing Factors on Hospitalization Expenses of Patients with Breast Malignant Tumor Undergoing Surgery: Based on the Neural Network and Support Vector Machine

Objective. Analyze the influencing factors of hospitalization expenses of breast cancer patients in a tertiary hospital in Chengdu and provide a basis and suggestion for controlling the unreasonable increase of medical expenses. Methods. The first pages of all inpatient medical records of patients with breast malignant tumor from 2017 to 2020 were extracted, and the descriptive analysis, single-factor analysis, and multifactor analysis were conducted by using the statistical method and data mining method to explore the influencing factors of hospitalization expenses. Results. In 2017–2020, the average hospitalization cost and the average surgical treatment cost increased year by year, and the number of operations, actual hospitalization days, and CCI were the important influencing factors. Conclusion. It is suggested to strengthen the supervision of medical rationality and eliminate the waste of medical resources; and we should improve the efficiency of diagnosis and treatment services, so as to shorten the actual length of hospitalization; at the same time, the combination of DRG grouping and fine management can be used to control the hospitalization expenses.

The Acquisition of Position and Orientation of the Conveyor Belt Workpiece Based on the Inter Frame Difference in ROI in Camera Video

Conveyor belt transfer is a widely used transportation means in industry and agriculture, with the help of the robot arms the workpiece on the belt can be picked and placed, replacing human sorters for production lines work. The position and orientation of the workpiece are important for grabbing by the robot arms. The goal of the paper was to investigate the acquisition of the position and orientation of the conveyor belt workpiece by means of the camera video overhead looking down the belt. The proposed method is the inter frame difference in nature, using the conveyor belt background as the first frame, but the other frames were not used wholly as usually, only an ROI all around the conveyor belt in the camera video was chosen, and the inter frame difference was carried out in the ROI. The ROI was of the same width as that of the belt in the video which was known in advance, while the length of the ROI was arbitrary, so one pixel in the frame was scaled to the actual length conveniently. Every read frame behind the background was computed the difference with the background in such ROI, and the four vertexes coordinates of the rectangle workpiece image on the belt were obtained when it passed the ROI, and then the distance apart from the right belt boundary was calculated due to the proportional relation between the width of workpiece and that of the ROI. Two kind workpiece orientation on the belt toward the left and right were judged using the same obtained four vertexes coordinates by means of Euclidian length, and the tilt angle was calculated by arc tangent function in favour of two narrow sides of rectangle workpiece grab. The actual test showed that the method of obtaining the position and orientation of workpiece on the belt proposed in the paper could be realized correctly.

Deviation Analyses of Computer-Assisted, Template-Guided Mandibular Reconstruction With Combined Osteotomy and Reconstruction Pre-Shaped Plate Position Technology: A Comparative Study

BackgroundComputer-assisted and template-guided mandibular reconstruction provides higher accuracy and less variation than conventional freehand surgeries. The combined osteotomy and reconstruction pre-shaped plate position (CORPPP) technique is a reliable choice for mandibular reconstruction. This study aimed to evaluate the accuracy of CORPPP-guided fibular flap mandibular reconstruction and analyze the possible causes of the deviations.Patients and MethodsFrom June 2015 to December 2016, 28 patients underwent fibular flap mandibular reconstruction. Virtual planning and personalized CORPPP-guided templates were applied in 15 patients while 13 patients received conventional freehand surgeries. Deviations during mandibulectomy and fibular osteotomy, and overall and triaxial deviation of the corresponding mandibular anatomical landmarks were measured by superimposing the pre- and postoperative virtual models.ResultsThe deviation of the resection line and resection angle was 1.23 ± 0.98 mm and 4.11° ± 2.60°. The actual length of fibula segments was longer than the designed length in 7 cases (mean: 0.35 ± 0.32 mm) and shorter in 22 cases (mean: 1.53 ± 1.19 mm). In patients without ramus reconstruction, deviations of the ipsilateral condylar head point (Co.), gonion point (Go.), and coracoid process point (Cor.) were 6.71 ± 3.42 mm, 5.38 ± 1.71 mm, and 11.05 ± 3.24 mm in the freehand group and 1.73 ± 1.13 mm, 1.86 ± 0.96 mm, and 2.54 ± 0.50 mm in the CORPPP group, respectively, with significant statistical differences (p < 0.05). In patients with ramus reconstruction, deviations of ipsilateral Co. and Go. were 9.79 ± 4.74 mm vs. 3.57 ± 1.62 mm (p < 0.05), and 15.17 ± 6.53 mm vs. 4.36 ± 1.68 mm (p < 0.05) in the freehand group and CORPPP group, respectively.ConclusionMandibular reconstructions employing virtual planning and personalized CORPPP-guided templates show significantly higher predictability, convenience, and accuracy of mandibular reconstruction compared with conventional freehand surgeries. However, more clinical cases were required for further dimensional deviation analysis. The application and exploration of clinical practice would also continuously improve the design of templates.

Accuracy of Working Length Determination of Curved Canal Using Digital and Film-Based Radiography

Introduction: Digital and film-based radiography are the most common methods of working length determination. The objective of this study was to compare the accuracy of working length determination of curved canals using digital and film-based radiography. Materials & Methods: This experimental and interventional study, included forty teeth with curved canals conducted at the Dentistry Faculty of Isfahan University of Medical Sciences, in 2018. After access cavity preparation, the direct observation method of the apical tip of the file in the root apex determined the actual working length. Teeth were mounted in acrylic blocks. Canal curvature was calculated based on Schneider’s method using software of indirect digital radiography. Images gathered by E-speed film and digital sensors. A pre-curved file was used to measure the working length of film-based images. In digital radiography, a digital caliper was used to measure the working length with three and six clicks. Data were analyzed by repeated measure analysis, paired t-test, and Intraclass Correlation Coefficient. The Level of significance was set at 0.001. Results: All groups overestimated the actual length although there weren’t any significant differences (p value > 0.05). Paired t-test didn’t show any significant differences between digital and film-based groups (p value > 0.05). Conclusion: Considering several advantages of digital radiography over the film-based method, it is the preferred method for working length determination of curved canals.

Comparison of the accuracy of different electronic apex locators used in working length determination via changing of initial cleaning solutions

Aim: The aim of this study is to compare the accuracy of the Root ZX Mini, Raypex 6, E-Pex Pro, and Propex Pixi electronic apex locators by changing the initial cleaning solutions (NaOCl vs. EDTA). Methodology: Eighty mandibular premolar teeth were used. Radiographs were obtained from the mesio-distal and bucco-lingual angles for all teeth, and teeth with suspected external or internal root resorption and/or calcified canals were not included in the study. The true canal lengths of the teeth were determined with a precision of 0.01 mm with a stereomicroscope at x5 magnification by placing a #20 K-type canal file into the root canal. The samples were then embedded in freshly mixed alginate blocks up to the cemento-enamel junction. The coronal 1/3 was pre-enlarged with a Protaper SX instrument. Electronic apex finders (Root ZX Mini, Raypex 6, E-Pex Pro, Propex Pixi) specified on each tooth were used, and measurements were made by changing the initial solutions (NaOCl vs. EDTA). Distilled water was used between application of 5.25% NaOCl and 17% EDTA to prevent chemical interactions. Three measurements were taken for each tooth, and the average of these 3 measurements was taken as reference. The data obtained in this study were analyzed. Results: There were no statistically significant differences between the solutions in terms of the measurement values and actual length values found by each device (p>0.05). Although there were no statistically significant differences, the deviation from the actual measurement was greater when EDTA solution was used than when NaOCl solution was used. In addition, although the difference was not found to be statistically significant, the deviation from the actual measurement was found to be highest when the Root ZX mini device was used with NaOCl and EDTA solution. Conclusion: The results of this study showed that the difference in the initial washing solutions did not affect the EAL devices in making measurements close to the true length. How to cite this article: Tellioğlu Avcı GR, Kaya S Comparison of the accuracy of different electronic apex locators used in working length determination via changing of initial cleaning solutions. Int Dent Res 2021;11(Suppl.1):56-62. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.9 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Comparison of the accuracy of three different electronic apex locators used in root canals enlarged in different apical diameters

Aim: This study aimed to evaluate the accuracy of three apex locators in enlarged teeth with different apical diameters using files that are compatible and incompatible with the apical diameters. Methodology: Sixty lower premolars were used in this study. The actual canal length was determined with a stereo microscope, and the teeth were divided into three different groups (G25, G40 and G50). The teeth in G25, G40 and G50 were enlarged in actual canal length with apical diameters of 0.25, 0.40 and 0.50 mm using hand files and Reciproc R25, R40, and R50, respectively. In the electronic measurements, a #15 hand file was used in each group, and #25, #40 and #50 hand files that were compatible with the apical diameters of the teeth in the groups were used. An alginate model was created with enlarged teeth. The electronic working length was determined for each tooth using Root ZX Mini, Raypex 6, and Propex Pixi electronic apex locators (EALs). Results: Electronic measurement results that were shorter by 0.50 mm or longer by 0.05 mm than the actual length were considered unsuccessful; otherwise, they were deemed successful. Analysis of variance was used to evaluate the accuracy of the EALs with different files in the same apical diameter. For the different apical diameters, the chi-square exact test was used to evaluate the accuracy effect of using files that were incompatible with each apical diameter. The level of significance was p > 0.05. In all the groups, the measured lengths were closer to the actual canal length with the use of #25, #40 and #50 hand files that were compatible with the apical diameters. However, there was no significant difference between the measurements with the #15 hand file (p > 0.05). According to the electronic measurement results made with the #15 hand file in teeth with 0.25, 0.40 and 0.50 apical diameters, the use of a file that was incompatible with the apical diameter did not have a significant effect on accuracy (p > 0.05). Conclusion: The use of a file that is compatible with the apical diameter of the tooth in the determination of the working length with measurement of EALs close to the actual canal length. The accuracy of EALs is not affected by the file size in electronic measurements with file sizes smaller than the apical diameter in teeth with apical diameters up to 0.50 mm. How to cite this article: Öz H, Adıgüzel Ö, Kaya S. Comparison of the accuracy of three different electronic apex locators used in root canals enlarged in different apical diameters. Int Dent Res 2021;11(Suppl.1):12-8. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.3 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.