scholarly journals ANALYSIS OF THE SIDE-LAP EFFECT ON FULL-WAVEFORM LIDAR DATA ACQUISITION FOR THE ESTIMATION OF FOREST STRUCTURE VARIABLES

2016 ◽  
Vol XLI-B8 ◽  
pp. 603-610 ◽  
Author(s):  
P. Crespo-Peremarch ◽  
L. A. Ruiz ◽  
A. Balaguer-Beser ◽  
J. Estornell
Keyword(s):  
Forest Structure ◽  
Canopy Structure ◽  
Wilcoxon Test ◽  
Voxel Size ◽  
Paired Samples ◽  
Full Waveform ◽  
Pulse Density ◽  
Point Density ◽  
Voxel Value ◽  
Two Parameters

LiDAR full-waveform provides a better description of the physical and forest vertical structure properties than discrete LiDAR since it registers the full wave that interacts with the canopy. In this paper, the effect of flight line side-lap is analysed on forest structure and canopy fuel variables estimations. Differences are related to pulse density changes between flight stripe side-lap areas, varying the point density between 2.65 m<sup>−2</sup> and 33.77 m<sup>−2</sup> in our study area. These differences modify metrics extracted from data and therefore variable values estimated from these metrics such as forest stand variables. In order to assess this effect, 64 pairwise samples were selected in adjacent areas with similar canopy structure, but having different point densities. Two parameters were tested and evaluated to minimise this effect: voxel size and voxel value assignation testing maximum, mean, median, mode, percentiles 90 and 95. <br><br> Student’s t-test or Wilcoxon test were used for the comparison of paired samples. Moreover, the absolute value of standardised paired samples was calculated to quantify dissimilarities. It was concluded that optimizing voxel size and voxel value assignation minimised the effect of point density variations and homogenised full-waveform metrics. Height/median ratio (HTMR) and Vertical distribution ratio (VDR) had the lowest variability between different densities, and Return waveform energy (RWE) reached the best improvement with respect to initial data, being the difference between standardised paired samples 1.28 before and 0.69 after modification.

scholarly journals ANALYSIS OF THE SIDE-LAP EFFECT ON FULL-WAVEFORM LIDAR DATA ACQUISITION FOR THE ESTIMATION OF FOREST STRUCTURE VARIABLES

2016 ◽  
Vol XLI-B8 ◽  
pp. 603-610
Author(s):  
P. Crespo-Peremarch ◽  
L. A. Ruiz ◽  
A. Balaguer-Beser ◽  
J. Estornell
Keyword(s):  
Forest Structure ◽  
Canopy Structure ◽  
Wilcoxon Test ◽  
Voxel Size ◽  
Paired Samples ◽  
Full Waveform ◽  
Pulse Density ◽  
Point Density ◽  
Voxel Value ◽  
Two Parameters

LiDAR full-waveform provides a better description of the physical and forest vertical structure properties than discrete LiDAR since it registers the full wave that interacts with the canopy. In this paper, the effect of flight line side-lap is analysed on forest structure and canopy fuel variables estimations. Differences are related to pulse density changes between flight stripe side-lap areas, varying the point density between 2.65&thinsp;m<sup>&minus;2</sup> and 33.77&thinsp;m<sup>&minus;2</sup> in our study area. These differences modify metrics extracted from data and therefore variable values estimated from these metrics such as forest stand variables. In order to assess this effect, 64 pairwise samples were selected in adjacent areas with similar canopy structure, but having different point densities. Two parameters were tested and evaluated to minimise this effect: voxel size and voxel value assignation testing maximum, mean, median, mode, percentiles 90 and 95. <br><br> Student’s t-test or Wilcoxon test were used for the comparison of paired samples. Moreover, the absolute value of standardised paired samples was calculated to quantify dissimilarities. It was concluded that optimizing voxel size and voxel value assignation minimised the effect of point density variations and homogenised full-waveform metrics. Height/median ratio (HTMR) and Vertical distribution ratio (VDR) had the lowest variability between different densities, and Return waveform energy (RWE) reached the best improvement with respect to initial data, being the difference between standardised paired samples 1.28 before and 0.69 after modification.

scholarly journals Analysis of Side-Lap Effect and Characterization of Understory Vegetation Using Full-Waveform ALS

Proceedings ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 6
Author(s):  
Pablo Crespo-Peremarch
Keyword(s):  
Forest Structure ◽  
Understory Vegetation ◽  
Voxel Size ◽  
Full Waveform ◽  
Pulse Density ◽  
The Mean ◽  
Waveform Lidar ◽  
Full Waveform Lidar ◽  
Structure Properties

Airborne full-waveform LiDAR (ALSFW) is able to register forest structure properties, essential for fire prevention, in more detail than airborne discrete LiDAR (ALSD). However, few studies have analyzed ALSFW methodological parameters (i.e., voxel size and assignation value) due to the complexity and lack of processing tools. In this paper we analyze the influence of the pulse density and ALSFW methodological parameters on the ALSFW metrics, as well as the characterization of understory vegetation through ALSFW. Results show that the influence of pulse density on ALSFW metrics may be modelled and the differences reduced by modifying ALSFW methodological parameters. Additionally, the potential of ALSFW for characterizing the mean height (R2 = 0.949) and volume (R2 = 0.951) of the understory vegetation was also proved.

scholarly journals Processing and analysis of airborne full-waveform laser scanning data for the characterization of forest structure and fuel properties

2020 ◽  
pp. 95
Author(s):  
P. Crespo-Peremarch ◽  
L. A. Ruiz
Keyword(s):  
Forest Structure ◽  
Laser Scanning ◽  
Software Tool ◽  
Understory Vegetation ◽  
Airborne Laser Scanning ◽  
Vegetation Density ◽  
Regression Methods ◽  
Full Waveform ◽  
Airborne Laser ◽  
Pulse Density

<p class="Bodytext">This PhD thesis addresses the development of full-waveform airborne laser scanning (ALS<sub>FW</sub>) processing and analysis methods to characterize the vertical forest structure, in particular the understory vegetation. In this sense, the influence of several factors such as pulse density, voxel parameters (voxel size and assignation value), scan angle at acquisition, radiometric correction and regression methods is analyzed on the extraction of ALS<sub>FW</sub> metric values and on the estimate of forest attributes. Additionally, a new software tool to process ALS<sub>FW</sub> data is presented, which includes new metrics related to understory vegetation. On the other hand, occlusion caused by vegetation in the ALS<sub>FW</sub>, discrete airborne laser scanning (ALS<sub>D</sub>) and terrestrial laser scanning (TLS) signal is characterized along the vertical structure. Finally, understory vegetation density is detected and determined by ALS<sub>FW</sub> data, as well as characterized by using the new proposed metrics.</p>

scholarly journals The Acute Effects of Dynamic and Static Stretching on Tennis Serve Targeting Performance

2019 ◽  
Vol 7 (4) ◽  
pp. 123
Author(s):  
Bulent Turna ◽  
Asuman Sahan ◽  
Bahar Yilmaz
Keyword(s):  
Wilcoxon Test ◽  
Static Stretching ◽  
Acute Effects ◽  
Warm Up ◽  
Dynamic Stretching ◽  
Paired Samples ◽  
Tennis Serve ◽  
Playing Time ◽  
Homogeneous Data ◽  
Stretching Exercises

The study investigates the acute effects of dynamic and static stretching on the tennis serve targeting performance of amateur tennis players. Twenty male athletes who were between the ages of 16-24 years and played tennis for at least 1 year (21.40±2.16 years, 181±0.06 cm, 71.85±7.42 kg, tennis playing time 1.55±0.88 years) voluntarily participated in the study.Prior to the pre-tests and after applying the traditional warm-up protocol, serve targeting test (STT) was applied to all participants. In the post-tests, STT was used after applying three different warm-up methods on three different days (48-hour rest interval). The warm-up stages included No Treatment (NT) (jogging, rally), Static Stretching (SS) and Dynamic Stretching (DS).In the statistical analysis, the homogeneity of the data was investigated using the Shapiro Wilk test. The Wilcoxon test was used to compare the pre-test and post-test results of the non-homogeneous data; Friedman test was used to compare the three different stretching methods with each other; in the paired comparisons of the groups, the paired samples t-test was used for the homogenous data and Wilcoxon test was used for the non-homogeneous data. In conclusion, stretching exercises before serving increased the serve targeting performance and the increase in the dynamic stretching exercises was higher than that in static stretching exercises.

scholarly journals Non-pharmacological motor-cognitive treatment to improve the mental health of elderly adults

2019 ◽  
Vol 65 (3) ◽  
pp. 394-403 ◽  
Author(s):  
Javiera Ponce ◽  
Claudia Latín ◽  
Víctor Leiva ◽  
Guillermo Cortés ◽  
Fernando Rodríguez ◽  
...  
Keyword(s):  
Dual Task ◽  
Low Cost ◽  
Wilcoxon Test ◽  
P Value ◽  
Elderly Adults ◽  
Cognitive Level ◽  
Post Intervention ◽  
Institutionalized Elderly ◽  
Paired Samples ◽  
Parametric Version

SUMMARY OBJECTIVE: To propose a program of physical-cognitive dual task and to measure its impact in Chilean institutionalized elderly adults. METHOD: Experimental design study with pre and post-intervention evaluations, measuring the cognitive and depressive levels by means of the Pfeiffer test and the Yesavage scale, respectively. The program was applied for 12 weeks to adults between 68 and 90 years old. The statistical analysis was based on the nonparametric Wilcoxon test for paired samples and was contrasted with its parametric version. The statistical software R was used. RESULTS: Statistically significant differences were obtained in the cognitive level (p-value < 0.05) and highly significant (p-value < 0.001) in the level of depression with both tests (parametric and nonparametric). CONCLUSION: Due to the almost null evidence of scientific interventions of programs that integrate physical activity and cognitive tasks together in Chilean elderly adults, a program of physical-cognitive dual task was proposed as a non-pharmacological treatment, easy to apply and of low cost to benefit their integral health, which improves significantly the cognitive and depressive levels of institutionalized elderly adults.

scholarly journals MANIPULASI TOPURAK (TOTOK, PUKUL, GERAK) UNTUK PENYEMBUHAN NYERI DAN KETEGANGAN OTOT LEHER

MEDIKORA ◽  
2019 ◽  
Vol 17 (2) ◽  
pp. 113-119
Author(s):  
Ela Yuliana ◽  
B.M. Wara Kushartanti
Keyword(s):  
Muscle Tension ◽  
Pain Scale ◽  
T Test ◽  
Wilcoxon Test ◽  
Neck Muscle ◽  
Lateral Flexion ◽  
Paired Samples ◽  
Neck Function ◽  
Quota Sampling ◽  
And Function

Nyeri dan ketegangan otot leher merupakan keluhan muskuloskeletal umum yang sering dirasakan setiap orang (prevalensi 30%-50%). Topurak (Totok, Pukul, Gerak) merupakan salah satu terapi manipulasi. Tujuan penelitian ini adalah untuk menguji efektivitas manipulasi Topurak untuk penyembuhan nyeri dan ketegangan otot leher pasien Klinik Olahraga Terapi dan Rehabilitasi FIK UNY. Rancangan Pre-experimental dengan One Group Pretest-Posttest Design. Teknik pengambilan sampel menggunakan quota sampling yang dihitung dengan rumus Slovin didapatkan quota sebesar 15 orang. Data yang dikumpulkan adalah ROM, skala nyeri, dan skala fungsi baik sebelum maupun sesudah perlakukan. Paired Samples t Test digunakan untuk menganalisis data ROM dan uji Wilcoxon untuk data skala nyeri maupun skala fungsi. Hasil penelitian menunjukkan adanya peningkatan ROM pada gerakan fleksi, ekstensi, left lateral flexion, right lateral flexion, left rotation, dan right rotation. Didapatkan juga adanya penurunan skala nyeri serta peningkatan skala fungsi leher setelah manipulasi Topurak (p<0,05). Berdasarkan hasil tersebut, maka dapat disimpulkan bahwa manipulasi Topurak efektif untuk penyembuhan nyeri dan ketegangan otot leher. TOPURAK MANIPULATION (TOUCH, PUNCH, MOTION) FOR HEALING OF PAIN AND NECK MUSCLE TENSIONAbstractNeck pain and muscle tension is a common musculoskeletal complaint that is often felt by everyone (prevalence of 30% -50%). Topurak (Touch, Pukul, Motion) is a manipulation therapy. and neck muscle tension of FIK UNY Sports and Therapy Sports and Rehabilitation Clinic patients. Pre-experimental design with One Group Pretest-Posttest Design. The sampling technique uses quota sampling which is calculated by Slovin formula obtained quota of 15 people. Data collected were ROM, pain scale, and function scale both before and after treatment. Paired Samples t Test is used to analyze ROM data and Wilcoxon test for pain scale and function scale data. The results showed an increase in ROM in flexion, extension, left lateral flexion, right lateral flexion, left rotation, and right rotation. There was also a decrease in pain scale and an increase in the scale of neck function after Topurak manipulation (p <0.05). Based on these results, it can be concluded that Topurak manipulation is effective for healing neck pain and muscle tension.

scholarly journals POTENTIAL OF FULL WAVEFORM AIRBORNE LASER SCANNING DATA FOR URBAN AREA CLASSIFICATION – TRANSFER OF CLASSIFICATION APPROACHES BETWEEN MISSIONS

2015 ◽  
Vol XL-7/W3 ◽  
pp. 1317-1323 ◽  
Author(s):  
G. Tran ◽  
D. Nguyen ◽  
M. Milenkovic ◽  
N. Pfeifer
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Point Clouds ◽  
Surface Model ◽  
Knowledge Based ◽  
Full Waveform ◽  
Airborne Laser ◽  
Point Density ◽  
Area Classification

Full-waveform (FWF) LiDAR (Light Detection and Ranging) systems have their advantage in recording the entire backscattered signal of each emitted laser pulse compared to conventional airborne discrete-return laser scanner systems. The FWF systems can provide point clouds which contain extra attributes like amplitude and echo width, etc. In this study, a FWF data collected in 2010 for Eisenstadt, a city in the eastern part of Austria was used to classify four main classes: buildings, trees, waterbody and ground by employing a decision tree. Point density, echo ratio, echo width, normalised digital surface model and point cloud roughness are the main inputs for classification. The accuracy of the final results, correctness and completeness measures, were assessed by comparison of the classified output to a knowledge-based labelling of the points. Completeness and correctness between 90% and 97% was reached, depending on the class. While such results and methods were presented before, we are investigating additionally the transferability of the classification method (features, thresholds …) to another urban FWF lidar point cloud. Our conclusions are that from the features used, only echo width requires new thresholds. A data-driven adaptation of thresholds is suggested.

scholarly journals Economic impact of biomaterials for bone regeneration in Brazil during the pandemic

2021 ◽  
Vol 10 (16) ◽  
pp. e74101623282
Author(s):  
Lana Karine Araújo ◽  
Jacques Antonio Cavalcante Maciel ◽  
Marcelo Miranda de Melo ◽  
Igor Iuco Castro-Silva
Keyword(s):  
Bone Regeneration ◽  
Economic Impact ◽  
Secondary Data ◽  
Bone Grafts ◽  
Wilcoxon Test ◽  
Oral Rehabilitation ◽  
Average Growth ◽  
Paired Samples ◽  
Health Products ◽  
Income Coefficient

Implantable devices are therapeutic options for oral rehabilitation, with several presentations available in the dental consumption market. The consumption power of health products is a little explored in the literature, particularly in the face of financial crises. The aim of this study was to evaluate the economic impact of biomaterials for bone regeneration in Brazil during the pandemic. A quantitative study was carried out through online document analysis, with publicly accessible secondary data extracted from IBGE and websites for the sale of dental products. Data collection in the second quarter of 2020 and 2021 of absolute values ​​of products, official GDP data and population estimates allowed the generation of a biomaterial/income coefficient. The categories obtained from grafts and membranes were stratified by composition, origin and industry. Statistical analysis used the Shapiro-Wilk test to assess normality, the non-parametric Kruskall-Wallis test to compare the means of variables and the Wilcoxon test for paired samples of medians according to the two periods, considering significant differences if p <0.05. Of 97 products analyzed, a higher frequency of bone grafts than barrier membranes was observed, with an average growth of 18.5% in the price of biomaterials, below 28.7% of GDP in the same period. The highest prevalence of biomaterials was the ceramic composition for bone grafts and resorbable polymeric for membranes, from the xenogenous source and Brazilian industry. There was a chronological decrease in the biomaterial/income coefficient in most categories, with a drop in the general average from 4.67±4.40% to 4.30±3.96%, accompanied by an increase in the median, demonstrating a trend towards homogeneity of this coefficient in the comparison between years. The drop in the coefficient indicates a greater purchasing power of biomaterials by the potential consumer. Market knowledge can contribute for the decision making in clinical planning involving bone regeneration.

scholarly journals Prospective study on a fast-track training in psychiatry for medical students: The Psychiatric Hat Game

2020 ◽  
Author(s):  
Anthony Clément ◽  
Raphaël Delage ◽  
Marie Chollier ◽  
Laure Josse ◽  
Stéphane Gaudry ◽  
...  
Keyword(s):  
Medical Students ◽  
Student Performance ◽  
Fast Track ◽  
Psychiatric Symptoms ◽  
Wilcoxon Test ◽  
Satisfaction Survey ◽  
Multiple Choice Questions ◽  
Friedman Analysis ◽  
Paired Samples ◽  
Game Session

Abstract Background: While medical students are losing interest in lectures in favor of other educational materials, many studies suggest the benefit of active learning, combined with gamified educational tools. The authors developed a psychiatric adaptation of the « Hat Game ». It was hypothesised that this game would increase both knowledge and motivation in medical students toward psychiatric semiology. The aim of the study was to assess the benefit of a Psychiatric Hat Game session for learning psychiatric symptoms in third-year medical students. Student performance was also evaluated at 3 months.Methods: This gamified fast-track training consisted of two teams and each team must guess as many psychiatric semiology terms as possible using different techniques (i.e. speech, mime). The study involved a pre- and post-evaluation of knowledge (Multiple Choice Questions) and a satisfaction survey. Baseline, post-immediate, and three-months scores were compared by using Friedman analysis for paired samples. Comparisons of mean scores at two different times were performed by using Wilcoxon test for paired samples.Results: Knowledge mean scores were significantly higher after the game than before (+ 28.6%, p < 0.001). Improvement was maintained three months after the game (+ 18.9%, p < 0.001). Satisfaction survey items highlighted that students enjoyed and would recommend this type of gamified training.Conclusions: The Psychiatric Hat Game improved knowledge of psychiatric semiology in medical students. Results suggest that it is a promising and efficient tool to playfully teach medical semiology, with transferable features, utility and acceptability from one medical field to another. This study contributes to the growing body of knowledge advocating for serious games and gamified training in medical education.

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