scholarly journals Analysis and Prediction of Gap Dynamics in a Secondary Deciduous Broadleaf Forest of Central Japan Using Airborne Multi-LiDAR Observations

2020 ◽  
Vol 13 (1) ◽  
pp. 100
Author(s):  
Kazuho Araki ◽  
Yoshio Awaya
Keyword(s):  
Linear Regression Analysis ◽  
Light Detection And Ranging ◽  
Lidar Data ◽  
Gap Dynamics ◽  
Central Japan ◽  
Broadleaf Forest ◽  
Strong Linear Correlation ◽  
Using Data ◽  
Deciduous Broadleaf Forest ◽  
Lidar Observations

Gaps are important for growth of vegetation on the forest floor. However, monitoring of gaps in large areas is difficult. Airborne light detection and ranging (LiDAR) data make precise gap mapping possible. We formulated a method to describe changes in gaps by time-series tracking of gap area changes using three digital canopy height models (DCHMs) based on LiDAR data collected in 2005, 2011, and 2016 over secondary deciduous broadleaf forest. We generated a mask that covered merging or splitting of gaps in the three DCHMs and allowed us to identify their spatiotemporal relationships. One-fifth of gaps merged with adjacent gaps or split into several gaps between 2005 and 2016. Gap shrinkage showed a strong linear correlation with gap area in 2005, via lateral growth of gap-edge trees between 2005 and 2016, as modeled by a linear regression analysis. New gaps that emerged between 2005 and 2011 shrank faster than gaps present in 2005. A statistical model to predict gap lifespan was developed and gap lifespan was mapped using data from 2005 and 2016. Predicted gap lifespan decreased greatly due to shrinkage and splitting of gaps between 2005 and 2016.

Phenology of leaf morphological, photosynthetic, and nitrogen use characteristics of canopy trees in a cool-temperate deciduous broadleaf forest at Takayama, central Japan

2014 ◽  
Vol 30 (2) ◽  
pp. 247-266 ◽  
Author(s):  
Hibiki M. Noda ◽  
Hiroyuki Muraoka ◽  
Kenlo Nishida Nasahara ◽  
Nobuko Saigusa ◽  
Shohei Murayama ◽  
...  
Keyword(s):  
Central Japan ◽  
Nitrogen Use ◽  
Broadleaf Forest ◽  
Canopy Trees ◽  
Cool Temperate ◽  
Temperate Deciduous ◽  
Deciduous Broadleaf Forest

scholarly journals Using Machine Learning Methods to Identify Particle Types from Doppler Lidar Measurements in Iceland

2021 ◽  
Vol 13 (13) ◽  
pp. 2433
Author(s):  
Shu Yang ◽  
Fengchao Peng ◽  
Sibylle von Löwis ◽  
Guðrún Nína Petersen ◽  
David Christian Finger
Keyword(s):  
Machine Learning ◽  
Weather Conditions ◽  
Dust Storms ◽  
Machine Learning Algorithms ◽  
Lidar Data ◽  
Data Sets ◽  
Doppler Lidar ◽  
Lidar Measurements ◽  
Using Data ◽  
Filter Noise

Doppler lidars are used worldwide for wind monitoring and recently also for the detection of aerosols. Automatic algorithms that classify the lidar signals retrieved from lidar measurements are very useful for the users. In this study, we explore the value of machine learning to classify backscattered signals from Doppler lidars using data from Iceland. We combined supervised and unsupervised machine learning algorithms with conventional lidar data processing methods and trained two models to filter noise signals and classify Doppler lidar observations into different classes, including clouds, aerosols and rain. The results reveal a high accuracy for noise identification and aerosols and clouds classification. However, precipitation detection is underestimated. The method was tested on data sets from two instruments during different weather conditions, including three dust storms during the summer of 2019. Our results reveal that this method can provide an efficient, accurate and real-time classification of lidar measurements. Accordingly, we conclude that machine learning can open new opportunities for lidar data end-users, such as aviation safety operators, to monitor dust in the vicinity of airports.

Sexual harassment and psychological complaints: student- and class-level associations

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
S Brolin Låftman ◽  
Y Bjereld ◽  
B Modin ◽  
P Löfstedt
Keyword(s):  
School Climate ◽  
Sexual Harassment ◽  
Linear Regression Analysis ◽  
Well Being ◽  
Negative Effects ◽  
School Class ◽  
School Aged Children ◽  
The Past ◽  
Class Level ◽  
Using Data

Abstract Background Students who are subjected to sexual harassment at school report lower psychological well-being than those who are not exposed. Yet, it is possible that the occurrence of sexual harassment in the school class is stressful also for those who are not directly targeted, with potential negative effects on well-being for all students. The aim was to examine whether sexual harassment at the student- and at the class-level was associated with students' psychological complaints. Methods Data from the Swedish Health Behaviour in School-aged Children (HBSC) of 2017/18 was used, with information from students aged 11, 13 and 15 years (n = 3,720 distributed across 209 classes). Psychological complaints were constructed as a summative index of four items capturing how often the student had felt low, felt irritable or bad tempered, felt nervous, or had difficulties to fall asleep, during the past six months (Cronbach's alpha=0.78). Sexual harassment at the student-level was measured by one item concerning bullying at school: “Other students have exposed me to sexual jokes”. Students who reported that this had happened at least “2 or 3 times a month” were classified as exposed to sexual harassment at school. Sexual harassment at the class-level was defined as the school class proportion of students exposed to sexual harassment, reported in per cent. Two-level linear regression analysis was applied. Results Students who had been exposed to sexual harassment had higher levels of psychological complaints (b = 2.74, p < 0.001). The proportion of students in the school class who had been exposed to sexual harassment was also associated with higher levels of psychological complaints, even when adjusting for sexual harassment at the student-level, gender and grade (b = 0.03, p = 0.015). Conclusions Sexual harassment is harmful for those who are exposed, but may also affect other students negatively. Thus, a school climate free from sexual harassment will profit all students. Key messages Using data collected among students aged 11, 13 and 15 years, this study showed that sexual harassment at the student- and class-level was associated with higher levels of psychological complaints. Sexual harassment is harmful for those who are exposed, but may also affect other students negatively. Thus, a school climate free from sexual harassment will profit all students.

scholarly journals Plant ecophysiological processes in spectral profiles: perspective from a deciduous broadleaf forest

2021 ◽  
Author(s):  
Hibiki M. Noda ◽  
Hiroyuki Muraoka ◽  
Kenlo Nishida Nasahara
Keyword(s):  
Remote Sensing ◽  
Optical Properties ◽  
Spectral Reflectance ◽  
Canopy Structure ◽  
Terrestrial Ecosystems ◽  
Optical Remote Sensing ◽  
Canopy Reflectance ◽  
Broadleaf Forest ◽  
Leaf Optical Properties ◽  
Deciduous Broadleaf Forest

AbstractThe need for progress in satellite remote sensing of terrestrial ecosystems is intensifying under climate change. Further progress in Earth observations of photosynthetic activity and primary production from local to global scales is fundamental to the analysis of the current status and changes in the photosynthetic productivity of terrestrial ecosystems. In this paper, we review plant ecophysiological processes affecting optical properties of the forest canopy which can be measured with optical remote sensing by Earth-observation satellites. Spectral reflectance measured by optical remote sensing is utilized to estimate the temporal and spatial variations in the canopy structure and primary productivity. Optical information reflects the physical characteristics of the targeted vegetation; to use this information efficiently, mechanistic understanding of the basic consequences of plant ecophysiological and optical properties is essential over broad scales, from single leaf to canopy and landscape. In theory, canopy spectral reflectance is regulated by leaf optical properties (reflectance and transmittance spectra) and canopy structure (geometrical distributions of leaf area and angle). In a deciduous broadleaf forest, our measurements and modeling analysis of leaf-level characteristics showed that seasonal changes in chlorophyll content and mesophyll structure of deciduous tree species lead to a seasonal change in leaf optical properties. The canopy reflectance spectrum of the deciduous forest also changes with season. In particular, canopy reflectance in the green region showed a unique pattern in the early growing season: green reflectance increased rapidly after leaf emergence and decreased rapidly after canopy closure. Our model simulation showed that the seasonal change in the leaf optical properties and leaf area index caused this pattern. Based on this understanding we discuss how we can gain ecophysiological information from satellite images at the landscape level. Finally, we discuss the challenges and opportunities of ecophysiological remote sensing by satellites.

PENGARUH KUALITAS PELAYANAN, KUALITAS PRODUK DAN KEPERCAYAAN TERHADAP LOYALITAS PELANGGAN AROMANIA PARFUMERY DI KOTA BENGKULU

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Sri Ekowati ◽  
Selamat Riyadi
Keyword(s):  
Service Quality ◽  
Product Quality ◽  
Customer Loyalty ◽  
Hypothesis Test ◽  
Linear Regression Analysis ◽  
Sampling Technique ◽  
Multiple Linear Regression Analysis ◽  
Quality Product ◽  
Using Data ◽  
Positive Effect

ABSTRACTThis study aims to determine the effect of service quality, product quality and  trust on customer loyalty aromania parfumery Bengkulu. This type of research is a survey research with a quantitative approach, the object of this research is the consumers in Aromania parfumery, which is precisely located on Jl. Kapuas Raya, Lingkar Barat, Kec. Gading Cempaka, Bengkulu City. with the sampling method, namely non-propability technique, namely insidential sampling technique. The number of respondents in this study were 105 people. The data collection method used a questionnaire. By using data analysis techniques using Multiple Linear Regression Analysis Test, and Hypothesis Test, namely test t and test f. The results of this study can be concluded that the variable service quality Aromania parfumery has a positive effect on customer loyalty, product quality has a positive effect on customer loyalty, and trust has a positive effect on customer loyalty.Keywords: Service Quality, Product Quality, Customer Trust and Loyalty.

scholarly journals Application of UAV-SfM photogrammetry and aerial lidar to a disastrous flood: repeated topographic measurement of a newly formed crevasse splay of the Kinu River, central Japan

2017 ◽  
Vol 17 (9) ◽  
pp. 1505-1519 ◽  
Author(s):  
Atsuto Izumida ◽  
Shoichiro Uchiyama ◽  
Toshihiko Sugai
Keyword(s):  
Lidar Data ◽  
High Definition ◽  
Central Japan ◽  
Aerial Photos ◽  
Data Resolution ◽  
Disastrous Flood ◽  
Surface Models ◽  
Elevation Changes ◽  
Aerial Vehicle ◽  
Crevasse Splay

Abstract. Geomorphic impacts of a disastrous crevasse splay that formed in September 2015 and its post-formation modifications were quantitatively documented by using repeated, high-definition digital surface models (DSMs) of an inhabited and cultivated floodplain of the Kinu River, central Japan. The DSMs were based on pre-flood (resolution: 2 m) and post-flood (resolution: 1 m) aerial light detection and ranging (lidar) data from January 2007 and September 2015, respectively, and on structure-from-motion (SfM) photogrammetry data (resolution: 3.84 cm) derived from aerial photos taken by an unmanned aerial vehicle (UAV) in December 2015. After elimination of systematic errors among the DSMs and down-sampling of the SfM-derived DSM, elevation changes on the order of 10−1 m – including not only topography but also growth of vegetation, vanishing of flood waters, and restoration and repair works – were detected. Comparison of the DSMs showed that the volume eroded by the flood was more than twice the deposited volume in the area within 300–500 m of the breached artificial levee, where the topography was significantly affected. The results suggest that DSMs based on a combination of UAV-SfM and lidar data can be used to quantify, rapidly and in rich detail, topographic changes on floodplains caused by floods.

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