Journal Issue: Journal of Advances in Engineering and Technology (JAET), Volume 1 Issue 1
Volume
Number
1
Issue Date
2022-09
Journal Title
Journal ISSN
Journal Volume
Articles
Design and Dynamic Modelling of Knee Exoskeleton for Disabled People through ADAMS-Simulink Co-simulation
(SLIIT, Faculty of Engineering, 2022-09-22) Ranaweera, J. P; Perera, M
This paper is written to outline the progress and findings of an undergraduate research project aimed at
the designing and modelling of an exoskeleton design of the knee joint for rehabilitation and gait support. It
focuses on the rehabilitation potential of the proposed exoskeleton design on patients with Hemiplegia and
Monoplegia conditions with the objective of seeking a feasible, simple means of joint actuation to reduce the
complexity of the design. Exoskeleton designs are able to provide rehabilitation and improve the overall quality
of life of disabled people globally. However, a common issue found almost everywhere is the costly nature of
the exoskeletons that are available in the market now as they are exclusive devices, which makes them
inaccessible and impractical to the general public, especially in developing countries. Initially, the paper focuses
on the review of relevant literature and previous research and evaluating the designs that have been developed
as of now. A thorough analysis of the work done by previous researchers and companies was conducted to
gather data on the underlying engineering principles and techniques used for the exoskeleton development as
well as any limitations or restrictions to the process.
Conceptual designing of the possible solutions was developed using the understanding and knowledge
gathered during the literature review. The selection of the best solution was based on the analysis of the pros
and cons of all the solutions. The chosen design, utilising a 4-bar mechanism, was then modelled using
SolidWorks software to provide a clear visualisation of the system. The kinematic and dynamic analysis of the
mechanism was evaluated to analyse the possibility of using the proposed exoskeleton design by replicating the
model in ADAMS multibody software. The dynamic analysis was conducted by using the co-simulation
platform between ADAMS and Simulink to enable the addition and control of feedback loops within the system.
The results of the analysis show that the design can achieve the required motions of the human gait cycle,
especially during the swing phase of the gait cycle. The analysis of the actuation torques and reaction forces on
the human body showed that an acceptable torque range was possible during the swing phase of the gait cycle.
Understanding the Characteristics of the Heatwaves using Temperature as the Only Variable – A Case Study on the Heatwaves in 1994 in South Korea
(SLIIT, Faculty of Engineering, 2022-09-22) Chandrasekara, S. S. K; Kwon, H. H
Acutely warm weather coupled with extreme weather variables or latent cooling due to a deficit of soil
moisture could generate heatwaves. South Korea is highly susceptible to heatwaves that occur annually in
different intensities and cause devastating impacts. This study aimed to identify the characteristics of the
heatwaves, especially focusing on one of the most severe heatwaves observed in 1994 in South Korea using
only temperature as a variable. The summer season, June to September (JJAS), was selected for the study
because heatwaves were prominent during the summer in South Korea. The maximum and minimum daily
temperatures were collected from the 67 meteorological stations located in South Korea. The mean daily 95th
percentiles of the temperatures were assessed to identify the heatwave durations and the intensities. In 1994, the
15 stations recorded their highest heatwave durations, and durations varied between 48 to 66 days in the JJAS
season. Busan station recorded the highest heatwave duration in 1994, which persisted for 66 days or throughout
half of the season. Further, it was interesting to identify that coastal meteorological stations were most
vulnerable to heatwaves in South Korea. However, the relationship between temperature intensities and
heatwave duration for coastal cities showed statistically low significance. Furthermore, it is identified that the
daily maximum temperature was most influential in the occurrence of heatwaves in both the coastal and
mainland meteorological stations, except for Pohang and Ulleungdo. Therefore, the characteristics of heatwaves
observed in 1994 in South Korea were identified using temperature as the only variable. Furthermore, a study
on the dynamic atmospheric oscillations due to heated waves in coastal regions of South Korea over
characteristics of heatwaves observed in South Korea is suggested
Application of Sentinel-2 Satellite Data to Map Forest Cover in Southeast Sri Lanka through the Random Forest Classifier
(SLIIT, Faculty of Engineering, 2022-09) Gunawansa, T; Perera, K; Apan, A; Hettiarachchi, N
Sentinel-2 satellite data has been used for forest cover monitoring for almost five years. Mapping
with Sentinel data will be a cost-effective solution for Sri Lanka, where the lack of updated land cover
maps with high spatial resolution is a significant challenge in the land resource management of the
country. A study area of about 5,000 km2
located in southeast Sri Lanka was selected for this study.
Agricultural lands, forests including Yala national park, and villages with perennial crops make up the
region. A Level-2A Sentinel-2 image with less than 10 percent cloud cover was used in the European
Space Agency's (ESA) SNAP software version 8.0.0 for image processing and the forest cover of the
study area was mapped through the Random Forest classifier (RFC). Normalized Difference Vegetation
Index (NDVI) is also calculated as a Sentinel product to support RFC output. For RFC, ground truth
data were collected through the reference of Google Earth high-resolution data. The classification
accuracy was assessed using the Google Earth image as the reference dataset. Furthermore, RFC results
were compared with NVDI greenness values. The classification accuracy was calculated using a
confusion matrix (error matrix) through randomly selected 100 sample points. The overall accuracy of
the land cover map was 85 percent, with a 96 percent accuracy for forest cover identification. The study
found RFC as an effective method to isolate forest cover in Sri Lanka.
Description
Keywords
Sentinel-2
Random Forest Classifier
Land cover classification
Land cover mapping
Normalized Difference Vegetation Index
Random Forest Classifier
Land cover classification
Land cover mapping
Normalized Difference Vegetation Index