6 research outputs found
Land cover and forest segmentation using deep neural networks
Tiivistelmä. Land Use and Land Cover (LULC) information is important for a variety of applications notably ones related to forestry. The segmentation of remotely sensed images has attracted various research subjects. However this is no easy task, with various challenges to face including the complexity of satellite images, the difficulty to get hold of them, and lack of ready datasets. It has become clear that trying to classify on multiple classes requires more elaborate methods such as Deep Learning (DL). Deep Neural Networks (DNNs) have a promising potential to be a good candidate for the task. However DNNs require a huge amount of data to train including the Ground Truth (GT) data. In this thesis a DL pixel-based approach backed by the state of the art semantic segmentation methods is followed to tackle the problem of LULC mapping. The DNN used is based on DeepLabv3 network with an encoder-decoder architecture. To tackle the issue of lack of data the Sentinel-2 satellite whose data is provided for free by Copernicus was used with the GT mapping from Corine Land Cover (CLC) provided by Copernicus and modified by Tyke to a higher resolution. From the multispectral images in Sentinel-2 Red Green Blue (RGB), and Near Infra Red (NIR) channels were extracted, the 4th channel being extremely useful in the detection of vegetation. This ended up achieving quite good accuracy on a DNN based on ResNet-50 which was calculated using the Mean Intersection over Union (MIoU) metric reaching 0.53MIoU. It was possible to use this data to transfer the learning to a data from Pleiades-1 satellite with much better resolution, Very High Resolution (VHR) in fact. The results were excellent especially when compared on training right away on that data reaching an accuracy of 0.98 and 0.85MIoU
Shariah Screening Methodologies: SAC-SC Vs DJIM Comparative Study and Impact Assessment on Their Performance
Purpose â The purpose of this paper is to compare between two screening methodologies in terms of applied methods and the impact assessment. Other than this the paper measures the performance of screened stocks in terms of risk & return and compare it to the conventional onesDesign/methodology/approach â The methods used are a combination of archival and bibliographic research based on some previously published articles. Also the papers use secondary data from published reports.Findings â The paper identifies the impact assessment of the screening methodologies and how investors will not sacrifice part of their returns in order to achieve their moral and ethical values.Originality/value â Many studies compared the two screening indices in term of methodologies; however this paper investigates and uses a quantitative analysis on the impact and performance of the screening methodologies. Furthermore it compares the stages of screening between Shariah Advisory Council of Securities commission (SAC-SC) and Dow Jones Islamic Market Index (DJIM)Keywords â screening, methodologies, impact assessmentPaper type â comparative case stud
Irrigation with treated wastewater affected the minor components of virgin olive oil from cv. Chemlali in Tunisia
Water limitation for agriculture is a problem
in many countries and irrigation with treated wastewater
(TWW) can be a tool to face the decreasing availability
of water for important domestic crops such as olive. Taking
into account this aspect, a research was carried out for
13 years in an olive grove (Chemlali cultivar) located in
the area of Sfax (Tunisia). Two different irrigation treatments
were applied: (a) irrigation with good quality water
(GQW) and (b) irrigation with TWW. The main objective
of this 13-year study was to verify the effects of the irrigation
with TWW vs. GQW on some minor parameters of the
virgin olive oil. Many oil parameters significantly increased
in the TWW irrigated plot, in particular lutein, total tocopherols,
squalene, campesterol and stigmasterol whereas
β-carotene, ι-tocopherol, δ-tocopherol, β-sitosterol and
total sterols decreased with respect to the GQW treatment.
Irrigation with TWW can be a possible tool to irrigate olive
groves with two positive effects: saving of freshwater and
production of olive oil of good quality