213 research outputs found
Determination of Genetic Relatedness among Selected Rice Cultivars Using Microsatellite Markers for Cultivars Improvement through Marker Assisted Breeding
Rice is grown in diverse environmental conditions. In this study, genetic variation
among thirteen Iranian and thirteen Malaysian rice cultivars was determined using
Microsatellite markers. Microsatellites are polymerase chain reaction (PCR) based and
dbla ceelcuoobeoy xoed (DNA) markers which are abundant, co-dominant and widely
used in various organisms. This study consisted of two parts, the first part was DNA
extraction, which consisted of comparing between four different DNA extraction
methods, namely the Dellaporta and CTAB as conventional methods also, Promega and
Axyprep as commercial protocols kits. Comparison was also made on the effect of
different leaf age as well as leaf position on different quality and yield of DNA obtained.
The results of the study showed significant difference (P<0.05) between different
extraction methods in relation to optical density OD 260/280 nm and DNA yield from each
method. The Dellaporta method (OD260/280=2±0.07nm and DNA yield 2073±196 ng) gave
the best results. The positions of different leafs (from top to bottom leaf number 4 to 1) and the ages of leafs (2, 4, 6 and 8 weeks) were also monitored for optimum DNA
extraction. The results of the Duncan test showed that there was no significant difference
(P>0.05) between leaf positions for 2 to 4 weeks old leaf. However, the age of leaves in
young and fresh stages of tissue showed significant difference (P<0.05) in ratio of
OD260/280 2±0.03 and DNA yield (1373±70 ng). The results (based on method of
extraction, leaf age and position) were used for subsequent DNA extraction of the 26
rice cultivars. The second part consisted of molecular work using twenty one
microsatellite primer pairs which were selected from the Gene Bank. The estimation of
genetic diversity among two rice groups (Iranian and Malaysian cultivars) were done
with the assistance of two softwares UVIdoc (ver.98) and POPGENE (ver.1.31). A total
of 21 loci (75 alleles) were observed, of which 20 loci (95.24 %) were polymorphic,
except RM338. Microsatellite loci RM1 and RM271 showed the highest polymorphism
(between 94 to 136 bp in size). The Polymorphism Information Content (PIC) value was
(0.578±0.170). The dendogram constructed based on genetic distance values (UPGMA)
grouped the cultivars into five clusters. All of the Iranian rice cultivars were placed in
cluster I and III while Malaysian rice cultivars were in clusters IV and V. However
cluster II consisted of both Iranian and Malaysian rice cultivars. The results of genetic
diversity among selected cultivars in this study can be used for screening of the high
grain quality rice accession for backcrossing and breeding programs
Contrastive Learning of View-Invariant Representations for Facial Expressions Recognition
Although there has been much progress in the area of facial expression
recognition (FER), most existing methods suffer when presented with images that
have been captured from viewing angles that are non-frontal and substantially
different from those used in the training process. In this paper, we propose
ViewFX, a novel view-invariant FER framework based on contrastive learning,
capable of accurately classifying facial expressions regardless of the input
viewing angles during inference. ViewFX learns view-invariant features of
expression using a proposed self-supervised contrastive loss which brings
together different views of the same subject with a particular expression in
the embedding space. We also introduce a supervised contrastive loss to push
the learnt view-invariant features of each expression away from other
expressions. Since facial expressions are often distinguished with very subtle
differences in the learned feature space, we incorporate the Barlow twins loss
to reduce the redundancy and correlations of the representations in the learned
representations. The proposed method is a substantial extension of our
previously proposed CL-MEx, which only had a self-supervised loss. We test the
proposed framework on two public multi-view facial expression recognition
datasets, KDEF and DDCF. The experiments demonstrate that our approach
outperforms previous works in the area and sets a new state-of-the-art for both
datasets while showing considerably less sensitivity to challenging angles and
the number of output labels used for training. We also perform detailed
sensitivity and ablation experiments to evaluate the impact of different
components of our model as well as its sensitivity to different parameters.Comment: Accepted in ACM Transactions on Multimedia Computing, Communications,
and Application
Exploring the Boundaries of Semi-Supervised Facial Expression Recognition: Learning from In-Distribution, Out-of-Distribution, and Unconstrained Data
Deep learning-based methods have been the key driving force behind much of
the recent success of facial expression recognition (FER) systems. However, the
need for large amounts of labelled data remains a challenge. Semi-supervised
learning offers a way to overcome this limitation, allowing models to learn
from a small amount of labelled data along with a large unlabelled dataset.
While semi-supervised learning has shown promise in FER, most current methods
from general computer vision literature have not been explored in the context
of FER. In this work, we present a comprehensive study on 11 of the most recent
semi-supervised methods, in the context of FER, namely Pi-model, Pseudo-label,
Mean Teacher, VAT, UDA, MixMatch, ReMixMatch, FlexMatch, CoMatch, and CCSSL.
Our investigation covers semi-supervised learning from in-distribution,
out-of-distribution, unconstrained, and very small unlabelled data. Our
evaluation includes five FER datasets plus one large face dataset for
unconstrained learning. Our results demonstrate that FixMatch consistently
achieves better performance on in-distribution unlabelled data, while
ReMixMatch stands out among all methods for out-of-distribution, unconstrained,
and scarce unlabelled data scenarios. Another significant observation is that
semi-supervised learning produces a reasonable improvement over supervised
learning, regardless of whether in-distribution, out-of-distribution, or
unconstrained data is utilized as the unlabelled set. We also conduct
sensitivity analyses on critical hyper-parameters for the two best methods of
each setting
Exploring the Landscape of Ubiquitous In-home Health Monitoring: A Comprehensive Survey
Ubiquitous in-home health monitoring systems have become popular in recent
years due to the rise of digital health technologies and the growing demand for
remote health monitoring. These systems enable individuals to increase their
independence by allowing them to monitor their health from the home and by
allowing more control over their well-being. In this study, we perform a
comprehensive survey on this topic by reviewing a large number of literature in
the area. We investigate these systems from various aspects, namely sensing
technologies, communication technologies, intelligent and computing systems,
and application areas. Specifically, we provide an overview of in-home health
monitoring systems and identify their main components. We then present each
component and discuss its role within in-home health monitoring systems. In
addition, we provide an overview of the practical use of ubiquitous
technologies in the home for health monitoring. Finally, we identify the main
challenges and limitations based on the existing literature and provide eight
recommendations for potential future research directions toward the development
of in-home health monitoring systems. We conclude that despite extensive
research on various components needed for the development of effective in-home
health monitoring systems, the development of effective in-home health
monitoring systems still requires further investigation.Comment: 35 pages, 5 figure
Human Pose Estimation from Ambiguous Pressure Recordings with Spatio-temporal Masked Transformers
Despite the impressive performance of vision-based pose estimators, they
generally fail to perform well under adverse vision conditions and often don't
satisfy the privacy demands of customers. As a result, researchers have begun
to study tactile sensing systems as an alternative. However, these systems
suffer from noisy and ambiguous recordings. To tackle this problem, we propose
a novel solution for pose estimation from ambiguous pressure data. Our method
comprises a spatio-temporal vision transformer with an encoder-decoder
architecture. Detailed experiments on two popular public datasets reveal that
our model outperforms existing solutions in the area. Moreover, we observe that
increasing the number of temporal crops in the early stages of the network
positively impacts the performance while pre-training the network in a
self-supervised setting using a masked auto-encoder approach also further
improves the results
Speech Emotion Recognition with Distilled Prosodic and Linguistic Affect Representations
We propose EmoDistill, a novel speech emotion recognition (SER) framework
that leverages cross-modal knowledge distillation during training to learn
strong linguistic and prosodic representations of emotion from speech. During
inference, our method only uses a stream of speech signals to perform unimodal
SER thus reducing computation overhead and avoiding run-time transcription and
prosodic feature extraction errors. During training, our method distills
information at both embedding and logit levels from a pair of pre-trained
Prosodic and Linguistic teachers that are fine-tuned for SER. Experiments on
the IEMOCAP benchmark demonstrate that our method outperforms other unimodal
and multimodal techniques by a considerable margin, and achieves
state-of-the-art performance of 77.49% unweighted accuracy and 78.91% weighted
accuracy. Detailed ablation studies demonstrate the impact of each component of
our method.Comment: Under revie
Consistency-guided Prompt Learning for Vision-Language Models
We propose Consistency-guided Prompt learning (CoPrompt), a new fine-tuning
method for vision-language models that addresses the challenge of improving the
generalization capability of large foundation models while fine-tuning them on
downstream tasks in a few-shot setting. The basic idea of CoPrompt is to
enforce a consistency constraint in the prediction of the trainable and
pre-trained models to prevent overfitting on the downstream task. Additionally,
we introduce the following two components into our consistency constraint to
further boost the performance: enforcing consistency on two perturbed inputs
and combining two dominant paradigms of tuning, prompting and adapter.
Enforcing consistency on perturbed input further regularizes the consistency
constraint, effectively improving generalization, while tuning additional
parameters with prompting and adapters improves the performance on downstream
tasks. Extensive experiments show that CoPrompt outperforms existing methods on
a range of evaluation suites, including base-to-novel generalization, domain
generalization, and cross-dataset evaluation tasks. On the generalization task,
CoPrompt improves the state-of-the-art by 2.09% on the zero-shot task and 1.93%
on the harmonic mean over 11 recognition datasets. Detailed ablation studies
show the effectiveness of each of the components in CoPrompt
Scaling Up Semi-supervised Learning with Unconstrained Unlabelled Data
We propose UnMixMatch, a semi-supervised learning framework which can learn
effective representations from unconstrained unlabelled data in order to scale
up performance. Most existing semi-supervised methods rely on the assumption
that labelled and unlabelled samples are drawn from the same distribution,
which limits the potential for improvement through the use of free-living
unlabeled data. Consequently, the generalizability and scalability of
semi-supervised learning are often hindered by this assumption. Our method aims
to overcome these constraints and effectively utilize unconstrained unlabelled
data in semi-supervised learning. UnMixMatch consists of three main components:
a supervised learner with hard augmentations that provides strong
regularization, a contrastive consistency regularizer to learn underlying
representations from the unlabelled data, and a self-supervised loss to enhance
the representations that are learnt from the unlabelled data. We perform
extensive experiments on 4 commonly used datasets and demonstrate superior
performance over existing semi-supervised methods with a performance boost of
4.79%. Extensive ablation and sensitivity studies show the effectiveness and
impact of each of the proposed components of our method
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