scholarly journals Hyperspectral based discrimination of thyroid and parathyroid during surgery

2018 ◽  
Vol 4 (1) ◽  
pp. 399-402 ◽  
Author(s):  
Manuel Barberio ◽  
Marianne Maktabi ◽  
Ines Gockel ◽  
Nada Rayes ◽  
Boris Jansen-Winkeln ◽  
...  
Keyword(s):  
Parathyroid Gland ◽  
Hyperspectral Imaging ◽  
Classification Algorithms ◽  
Anatomical Structures ◽  
New Approach ◽  
Spectral Signatures ◽  
Medical Area ◽  
The Mean ◽  
Absorbance Spectra ◽  
Deoxygenated Hemoglobin

AbstractUnintended injuring of anatomical structures during endocrine neck operations can have severe consequences for patient. Especially the nerves and the parathyroid gland can be hard to identify visually. Therefore, intraoperative methods are needed to support the surgeon in this task. Hyperspectral imaging (HSI) is a new approach in the medical area which combines a camera with a spectrometer. It showed promising results for the discrimination of tissue. In this work, HSI-data of seven patients were acquired during thyroid and parathyroid operations. The mean absorbance spectra of both glands showed differences in the range between 600 and 700 nm and at 760 and 960 nm. This means that thyroid and parathyroid have different oxygenation states and different contents of deoxygenated hemoglobin and water. From these observations, it is possible to define spectral signatures to characterize both glands. We showed on one patient how spectral signatures can be used in classification algorithms to automatically identify the thyroid and parathyroid from other structures.

Observation of the Pulp Chamber of Maxillary First Premolars: A Micro-computed Tomographic Study

2020 ◽  
Vol 16 (3) ◽  
pp. 224-230
Author(s):  
Gozde Serindere ◽  
Ceren Aktuna Belgin ◽  
Kaan Orhan
Keyword(s):  
Root Canal ◽  
Age Groups ◽  
Slice Thickness ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Pulp Chamber ◽  
Anatomical Structures ◽  
Computed Tomographic ◽  
The Mean ◽  
Chamber Floor

Background: There are a few studies about the evaluation of maxillary first premolars internal structure with micro-computed tomography (micro-CT). The aim of this study was to assess morphological features of the pulp chamber in maxillary first premolar teeth using micro- CT. Methods: Extracted 15 maxillary first premolar teeth were selected from the patients who were in different age groups. The distance between the pulp orifices, the diameter of the pulp and the width of the pulp chamber floor were measured on the micro-CT images with the slice thickness of 13.6 µm. The number of root canal orifices and the presence of isthmus were evaluated. Results: The mean diameter of orifices was 0.73 mm on the buccal side while it was 0.61 mm on palatinal side. The mean distance between pulp orifices was 2.84 mm. The mean angle between pulp orifices was -21.53°. The mean height of pulp orifices on the buccal side was 4.32 mm while the mean height of pulp orifices on the palatinal side was 3.56 mm. The most observed shape of root canal orifices was flattened ribbon. No isthmus was found in specimens. Conclusion: Minor anatomical structures can be evaluated in more detail with micro-CT. The observation of the pulp cavity was analyzed using micro-CT.

A new simpler approach to measure the strength of toe plantar flexion requiring no mechanical restraint with a light-weight device

2021 ◽  
pp. 095441192110029
Author(s):  
Yuko Komuro ◽  
Yuji Ohta
Keyword(s):  
Plantar Flexion ◽  
Mean Value ◽  
Simple Approach ◽  
Light Weight ◽  
New Approach ◽  
Mean Values ◽  
Mechanical Restraint ◽  
Significant Difference ◽  
Ankle Joints ◽  
The Mean

Conventionally, the strength of toe plantar flexion (STPF) is measured in a seated position, in which not only the target toe joints but also the knee and particularly ankle joints, are usually restrained. We have developed an approach for the measurement of STPF which does not involve restraint and considers the interactions of adjacent joints of the lower extremities. This study aimed to evaluate this new approach and comparing with the seated approach. A thin, light-weight, rigid plate was attached to the sole of the foot in order to immobilize the toe area. Participants were 13 healthy young women (mean age: 24 ± 4 years). For measurement of STPF with the new approach, participants were instructed to stand, raise the device-wearing leg slightly, plantar flex the ankle, and push the sensor sheet with the toes to exert STPF. The sensor sheet of the F-scan II system was inserted between the foot sole and the plate. For measurement with the seated approach, participants were instructed to sit and push the sensor with the toes. They were required to maintain the hip, knee, and ankle joints at 90°. The mean values of maximum STPF of the 13 participants obtained with each approach were compared. There was no significant difference in mean value of maximum STPF when the two approaches were compared (new: 59 ± 23 N, seated: 47 ± 33 N). The coefficient of variation of maximum STPF was smaller for data obtained with the new approach (new: 39%, seated: 70%). Our simple approach enables measurement of STPF without the need for the restraints that are required for the conventional seated approach. These results suggest that the new approach is a valid method for measurement of STPF.

scholarly journals A New Approach for Analyzing the Reliability of the Repair Facility in a Series System with Vacations

2012 ◽  
Vol 2012 ◽  
pp. 1-16
Author(s):  
Renbin Liu ◽  
Yong Wu
Keyword(s):  
Renewal Process ◽  
Decomposition Method ◽  
Process Theory ◽  
Series System ◽  
New Approach ◽  
Numerical Examples ◽  
Special Cases ◽  
The Mean ◽  
Repair Facility

Based on the renewal process theory we develop a decomposition method to analyze the reliability of the repair facility in ann-unit series system with vacations. Using this approach, we study the unavailability and the mean replacement number during(0,t]of the repair facility. The method proposed in this work is novel and concise, which can make us see clearly the structures of the facility indices of a series system with an unreliable repair facility, two convolution relations. Special cases and numerical examples are given to show the validity of our method.

scholarly journals Validity of Two Awake Wear-Time Classification Algorithms for activPAL in Youth, Adults, and Older Adults

2021 ◽  
pp. 1-12
Author(s):  
Jordan A. Carlson ◽  
Fatima Tuz-Zahra ◽  
John Bellettiere ◽  
Nicola D. Ridgers ◽  
Chelsea Steel ◽  
...  
Keyword(s):  
Older Adults ◽  
United Kingdom ◽  
Best Practices ◽  
Age Groups ◽  
Classification Algorithms ◽  
Wear Time ◽  
Self Rated Health ◽  
The Mean ◽  
Automated Algorithms ◽  
Multiple Assessment

Background: The authors assessed agreement between participant diaries and two automated algorithms applied to activPAL (PAL Technologies Ltd, Glasgow, United Kingdom) data for classifying awake wear time in three age groups. Methods: Study 1 involved 20 youth and 23 adults who, by protocol, removed the activPAL occasionally to create nonwear periods. Study 2 involved 744 older adults who wore the activPAL continuously. Both studies involved multiple assessment days. In-bed, out-of-bed, and nonwear times were recorded in the participant diaries. The CREA (in PAL processing suite) and ProcessingPAL (secondary application) algorithms estimated out-of-bed wear time. Second- and day-level agreement between the algorithms and diary was investigated, as were associations of sedentary variables with self-rated health. Results: The overall accuracy for classifying out-of-bed wear time as compared with the diary was 89.7% (Study 1) to 95% (Study 2) for CREA and 89.4% (Study 1) to 93% (Study 2) for ProcessingPAL. Over 90% of the nonwear time occurring in nonwear periods >165 min was detected by both algorithms, while <11% occurring in periods ≤165 min was detected. For the daily variables, the mean absolute errors for each algorithm were generally within 0–15% of the diary mean. Most Spearman correlations were very large (≥.81). The mean absolute errors and correlations were less favorable for days on which any nonwear time had occurred. The associations between sedentary variables and self-rated health were similar across processing methods. Conclusion: The automated awake wear-time classification algorithms performed similarly to the diary information on days without short (≤2.5–2.75 hr) nonwear periods. Because both diary and algorithm data can have inaccuracies, best practices likely involve integrating diary and algorithm output.

scholarly journals Effects of urban pollution on UV spectral irradiances

2008 ◽  
Vol 8 (2) ◽  
pp. 7149-7188 ◽  
Author(s):  
R. L. McKenzie ◽  
C. Weinreis ◽  
P. V. Johnston ◽  
B. Liley ◽  
H. Shiona ◽  
...  
Keyword(s):  
Boundary Layer ◽  
New Zealand ◽  
Tropospheric Ozone ◽  
Urban Pollution ◽  
Supplementary Data ◽  
Spectral Measurements ◽  
Spectral Signatures ◽  
Polluted Sites ◽  
The Mean ◽  
Pristine Site

Abstract. Spectral measurements of UV irradiances at Tokyo are compared with corresponding measurements at a pristine site (Lauder New Zealand) to identify the causes of the reductions in urban UV irradiances, and to quantify their effects. Tropospheric extinctions in Tokyo were found to be up to ~40% greater than at Lauder. Most of these differences can be explained by differences in cloud and aerosols, but ozone differences are also important in the summer. Examining spectral signatures of tropospheric transmission of both sites shows that reductions due to mean NO2 and SO2 amounts are generally small. However, at times the amount of NO2 can be 20 times higher than the mean amount, and on these days it can decrease the UV-A irradiance up to 50%. If SO2 shows comparable day to day variability, it would contribute to significant reductions in UV-B irradiances. The results indicate that at Tokyo, interactions between the larger burden of tropospheric ozone and aerosols also have a significant effect. These results have important implications for our ability to accurately retrieve surface UV irradiances at polluted sites from satellites that use backscattered UV. Supplementary data characterising these boundary layer effects are probably needed.

scholarly journals HYPERSPECTRAL REMOTE SENSING ROLE IN ENHANCING CROP MAPPING: A COMPARISON BETWEEN DIFFERENT SUPERVISED SEGMENTATION ALGORITHMS

2019 ◽  
Vol 1 (1) ◽  
pp. 25-37
Author(s):  
Mohamad M. Awad
Keyword(s):  
Remote Sensing ◽  
Eastern Mediterranean ◽  
Hyperspectral Data ◽  
Spectral Angle Mapper ◽  
New Approach ◽  
Spectral Signatures ◽  
Agriculture Sector ◽  
Supervised Segmentation ◽  
Eastern Mediterranean Basin ◽  
Crop Mapping

In agriculture sector there is need for cheap, fast, and accurate data and technologies to help decision makers to find solutions for many agricultural problems. Many solutions depend significantly on the accuracy and efficiency of the crop mapping and crop yield estimation processes. High resolution spectral remote sensing can improve substantially crop mapping by reducing similarities between different crop types which has similar ecological conditions. This paper presents a new approach of combining a new tool, hyperspectral images and technologies to enhance crop mapping.  The tool includes spectral signatures database for the major crops in the Eastern Mediterranean Basin and other important metadata and processing functions. To prove the efficiency of the new approach, major crops such as “winter wheat” and “spring potato” are mapped using the spectral signatures database in the new tool, three different supervised algorithms, and CHRIS-Proba hyperspectral satellite images. The evaluation of the results showed that deploying different hyperspectral data and technologies can improve crop mapping. The improvements can be noticed with the increase of the accuracy to more than 86% with the use of the supervised algorithm Spectral Angle Mapper (SAM).

scholarly journals The Mean Square Error of Prediction in the Chain Ladder Reserving Method – A Comment

2006 ◽  
Vol 36 (02) ◽  
pp. 543-552 ◽  
Author(s):  
Thomas Mack ◽  
Gerhard Quarg ◽  
Christian Braun
Keyword(s):  
Mean Square Error ◽  
Negative Correlation ◽  
Mean Square ◽  
New Approach ◽  
The Mean ◽  
Chain Ladder ◽  
Original Formula

We discuss some questionable points of the approach taken in the paper by Buchwalder, Bühlmann, Merz and Wüthrich and come to the conclusion that this approach does not yield an improvement of Mack’s original formula. The main reason is that the new approach disregards the negative correlation of the squares of the development factors. The same applies to the formula by Murphy (PCAS 1994).

scholarly journals Evaluation of Cleaning Processes Using Colorimetric and Spectral Data for the Removal of Layers of Limewash from Medieval Plasterwork

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7147
Author(s):  
Miguel Ángel Martínez-Domingo ◽  
Ana Isabel Calero Castillo ◽  
Eva Vivar García ◽  
Eva M. Valero
Keyword(s):  
Cultural Heritage ◽  
Hyperspectral Imaging ◽  
Color Difference ◽  
Cleaning Process ◽  
Heritage Preservation ◽  
The Mean ◽  
Cultural Heritage Preservation ◽  
Conservation Interventions

In the cultural heritage preservation of medieval buildings, it is common to find plaster walls covered in lime, which previously were painted in polychromy. The conservation interventions usually try to remove the whitewash, whilst maintaining the original color of the painted wall as much as possible. However, there is no agreement on which cleaning technique best preserves the original appearance of the colored plaster. Different pigments found below the lime layer may behave differently depending on the cleaning technique used. Usually, colorimetric or photometric area-based measurements are carried out to study the color of the cleaned areas to compare with their original color, obtained from pre-made plaster probes. However, this methodology fails when the mean color difference is not enough to fully characterize the changes in texture and color appearance. This study presents a set of experiments carried out using two different pigments (cinnabar and malachite) covered with lime, and treated with nine different cleaning techniques on plaster probes prepared according to medieval techniques. We have studied the effect of the cleaning process on the color and the homogeneity of the samples using a hyperspectral imaging workflow. Four different analysis methods are presented and discussed. Our results show that the proposed analysis is able to provide a much more comprehensive and diversified characterization of the quality of the cleaning method compared to the commonly used colorimetric or photometric area-based measurements.

Autonomous Human Flow Counting Service With Deep Neural Network

2018 ◽  
Vol 8 (3) ◽  
pp. 18-36
Author(s):  
Shing Hwang Doong
Keyword(s):  
Neural Network ◽  
Time Window ◽  
Classification Algorithms ◽  
Channel State ◽  
Counting Problem ◽  
State Information ◽  
Space Management ◽  
Final Layer ◽  
The Mean ◽  
Human Flow

Human flow counting has many applications in space management. This study applied channel state information (CSI) available in IEEE 802.11n networks to characterize the flow count. Raw features including the mean, standard deviation and five-number summary were extracted from CSI magnitudes in a time window. Due to the large number of raw features, stacked denoising autoencoders were used to extract higher level features and a final layer of softmax regression was used to classify the flow count. The resulting neural network beat many popular classification algorithms in predicting the correct flow size. In addition to CSI magnitudes, this study also explored the feasibility of using CSI phase-based features. It is found that the magnitude neural network provided a better prediction result than the phase neural network, and combining both networks yielded an even better solution to the flow counting problem.

Turbulent Wall-Pressure Fluctuations: A New Model for Off-Axis Cross-Spectral Density

1997 ◽  
Vol 119 (2) ◽  
pp. 277-280 ◽  
Author(s):  
B. A. Singer
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Spectral Density ◽  
Flow Direction ◽  
Wall Pressure ◽  
Mean Flow ◽  
New Approach ◽  
Cross Spectral Density ◽  
The Mean ◽  
The Cross

Models for the distribution of the wall-pressure under a turbulent boundary layer often estimate the coherence of the cross-spectral density in terms of a product of two coherence functions. One such function describes the coherence as a function of separation distance in the mean-flow direction, the other function describes the coherence in the cross-stream direction. Analysis of data from a large-eddy simulation of a turbulent boundary layer reveals that this approximation dramatically underpredicts the coherence for separation directions that are neither aligned with nor perpendicular to the mean-flow direction. These models fail even when the coherence functions in the directions parallel and perpendicular to the mean flow are known exactly. A new approach for combining the parallel and perpendicular coherence functions is presented. The new approach results in vastly improved approximations for the coherence.

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