44 research outputs found
Isogeometric analysis based on Geometry Independent Field approximaTion (GIFT) and Polynomial Splines over Hierarchical T-meshes
This thesis addresses an adaptive higher-order method based on a Geometry Independent Field approximatTion(GIFT) of polynomial/rationals plines over hierarchical T-meshes(PHT/RHT-splines).
In isogeometric analysis, basis functions used for constructing geometric models in computer-aided design(CAD) are also employed to discretize the partial differential equations(PDEs) for numerical analysis. Non-uniform rational B-Splines(NURBS) are the most commonly used basis functions in CAD. However, they may not be ideal for numerical analysis where local refinement is required.
The alternative method GIFT deploys different splines for geometry and numerical analysis. NURBS are utilized for the geometry representation, while for the field solution, PHT/RHT-splines are used. PHT-splines not only inherit the useful properties of B-splines and NURBS, but also possess the capabilities of local refinement and hierarchical structure. The smooth basis function properties of PHT-splines make them suitable for analysis purposes. While most problems considered in isogeometric analysis can be solved efficiently when the solution is smooth, many non-trivial problems have rough solutions. For example, this can be caused by the presence of re-entrant corners in the domain. For such problems, a tensor-product basis (as in the case of NURBS) is less suitable for resolving the singularities that appear since refinement propagates throughout the computational domain. Hierarchical bases and local refinement (as in the case of PHT-splines) allow for a more efficient way to resolve these singularities by adding more degrees of freedom where they are necessary. In order to drive the adaptive refinement, an efficient recovery-based error estimator is proposed in this thesis. The estimator produces a recovery solution which is a more accurate approximation than the computed numerical solution. Several two- and three-dimensional numerical investigations with PHT-splines of higher order and continuity prove that the proposed method is capable of obtaining results with higher accuracy, better convergence, fewer degrees of freedom and less computational cost than NURBS for smooth solution problems. The adaptive GIFT method utilizing PHT-splines with the recovery-based error estimator is used for solutions with discontinuities or singularities where adaptive local refinement in particular domains of interest achieves higher accuracy with fewer degrees of freedom. This method also proves that it can handle complicated multi-patch domains for two- and three-dimensional problems outperforming uniform refinement in terms of degrees of freedom and computational cost
Collapsible Tabular Visualization of Aspects in Object Oriented Programming
Due to its implicit invocation nature ofAspect Oriented Programming (AOP), locating a jointpoint for executing aspect is extremely difficult. Hence,it becomes difficult to understand the application’sflow and behavior. Current AOP visualization tools havelimitations such as high dependency on other tools,confusing and excessive use of color to represent aspectsand using an outdated version of AspectJ. In thispaper, we propose a new approach collapsibletabular visualization tool to visualize and represent AOPfeatures to aid the programmers in betterunderstanding AOP applications. We have come outof traditional color-based aspect visualization and developeda web based tool: AspectViz that visualizes the aspects ina simple collapsible table. A questionnaire containingfour different questions related to aspects visualizationwas developed to compare AspectViz with currentvisualization tools. 20 graduate students andprofessional software developers were invited to participatein the test experiment as well as the survey. We havecompared its performance with existing AOPvisualization tools i.e. the AJDT and the AspectMaps andshowed how it outperformed in many cases, which is nocolor confusion, simple tabular visualization of aspects, nodependency on third-party software, easy to understand andthe time it took to find a particular aspect was less etc.Collapsible tabular visualization enhanced the usability andperformance of aspect locating in aspect-orientedprogramming
Unbreakable Babu Culture and Commercial Sex Workers (CSWs) at Kandapara sex establishment, Bangladesh
The commercial sex trade with babu culture is a ubiquitous business that itself stands in an embarrassing platform, especially in a predominantly Islamic country like Bangladesh. This study aims to excavate the concept of commercial sex workers and unbreakable babus, the reasons for entering sex establishment, and also the perceptions about themselves for understanding and developing a meaningful relationship. The qualitative method was predominance for its nature and subject matter where in-depth interviews were carried out at Kandapara sex establishment in Tangail, Bangladesh. This study found that socio-demographic and economic factors badly influence them to attach to sex establishment. For commercial sex workers, both voluntary and involuntary factors are responsible to enter the sex establishment, alternatively, only voluntary factors are responsible for babus. This study also found that there are multi-dimensional and diverse perceptions among commercial sex workers and unbreakable babus about their fixed sex partners. The study also addressed taking initiatives for improving their social status in society and emphasizing the further implications of the research
Abundant Exact Traveling Wave Solutions of the (2+1)-Dimensional Couple Broer-Kaup Equations
To describe the propagation of small amplitude waves in nonlinear dispersive media, it is frequently necessary to take account of dissipative mechanisms to perfectly reflect real situations in many branches of physics like plasma physics, fluid dynamics and nonlinear optics. In this paper, the exp(-Fi(Eta))-expansion method is employed to solve the (2+1)-Dimensional couple Broer-Kaup equations as a model for wave propagation in nonlinear media with dispersive and dissipative effects. As a result, a number of exact traveling wave solutions including solitary wave and periodic wave have been found for the equation. Some representative 3D profiles and 2D profiles for different values of variables of the wave solutions are graphically displayed and discussed
Social Responsibility in Global Supply Chain: Research Trend from 1999 to 2014
The well know term of corporate social responsibility (CSR) or simply social responsibility for business organization refers to the concept where the companies integrate social and environmental concerns into their day to day business operations. The aim of this article is to observe the social responsibility research trend within global supply chain. Based on the review of prior literature, it is easy to say that the concept of CSR has received overwhelming attention by the professional and academia of all over the global. Even though, there is debate whether the companies have any responsibility for their supplier premises, more literatures are confirming that the business organizations are considering carefully the issues of CSR within supply chain. Since the concept of CSR covering enter arena of business, it is interesting to work on literature and discover the recent research trend on CSR study within supply chain. Current study has taken an initiative to determine the drivers that influence CSR practice within the supply chain based on literature review for sixteen years Finding suggests, there are drivers influences CSR practice within supply chain
COVID-19 Pandemic and Its Effects on Youth Mental Health in Bangladesh
COVID-19 is a worldwide pandemic that is caused by severe acute respiratory syndrome coronavirus (SAR-CoV-2). For the effect of this pandemic, the people of Bangladesh are suffering from unprecedented challenges of all ages. Coronavirus pandemic has hit the young mental health badly. The main purpose of this research was to investigate the mental health condition among young people during the COVID-19 pandemic in Bangladesh. In this study, a qualitative research method was used where twenty case studies were carried out to evaluate critical situations as well as the determinants of psychological health problems that young adults are facing. Result demonstrates that like other ages, young people are bound to stay at home during lockdown that causes a profound effect on their mental health. Due to COVID-19 young people are going through a variety of critical situations including financial hardship, conflict with family members, quarantine-related crisis, increasing pressure for marriage, extreme addiction to the virtual world, and addiction to different video games that threaten their psychological health, for example increasing suicidal tendency, loneliness, anxiety, depression, psychological trauma, low self-confidence anger, etc. Researchers have suggested some potential recommendations to reduce the psychological pressure of young people during pandemics
Less is More: Facial Landmarks can Recognize a Spontaneous Smile
Smile veracity classification is a task of interpreting social interactions.
Broadly, it distinguishes between spontaneous and posed smiles. Previous
approaches used hand-engineered features from facial landmarks or considered
raw smile videos in an end-to-end manner to perform smile classification tasks.
Feature-based methods require intervention from human experts on feature
engineering and heavy pre-processing steps. On the contrary, raw smile video
inputs fed into end-to-end models bring more automation to the process with the
cost of considering many redundant facial features (beyond landmark locations)
that are mainly irrelevant to smile veracity classification. It remains unclear
to establish discriminative features from landmarks in an end-to-end manner. We
present a MeshSmileNet framework, a transformer architecture, to address the
above limitations. To eliminate redundant facial features, our landmarks input
is extracted from Attention Mesh, a pre-trained landmark detector. Again, to
discover discriminative features, we consider the relativity and trajectory of
the landmarks. For the relativity, we aggregate facial landmark that
conceptually formats a curve at each frame to establish local spatial features.
For the trajectory, we estimate the movements of landmark composed features
across time by self-attention mechanism, which captures pairwise dependency on
the trajectory of the same landmark. This idea allows us to achieve
state-of-the-art performances on UVA-NEMO, BBC, MMI Facial Expression, and SPOS
datasets
Susceptibility of microorganism to selected medicinal plants in Bangladesh
ABSTRACTObjectiveTo analyze in-vitro antimicrobial activities of some ethno-pharmacologically significant medicinal plants (methanol extract) against the pathogenic microorganisms (Escherichia coli, Salmonella spp., Bacillus cereus, Staphylococcus aureus, Aspergillus niger and Candida albicans).MethodsThe disc diffusion method was applied for antibacterial test and the poisoned food technique was applied for antifungal test.ResultsThe methanol extract of Terminalia chebula (bark), Phyllanthus acidus (fruits), Sarcochlamys pulcherrima (leaves) and Abelmoschus esculentus (fruits) had significant in vitro antibacterial activity angainst the entire test samples in comparison to standard drug ciprofloxacin. Most of the plant extracts showed low activity against Gram negative bacteria while potential activity against Gram positive bacteria. The antifungal activities of methanol extracts of these plants and standard drug griseofulvin were determined against two pathogenic fungi, and Polygonum lapathifolium (leaves) and Cinnamomum tamala (leaves) showed maximum activity, while Erioglossum rubiginosum (leaves) showed no antifungal activity.ConclusionsFurther chemical and pharmacological investigations are required to identify and isolate chemical constituents responsible for these potential bioactivities and thus to determine their full spectrum of efficacy
Stealth cranioplasty in symptomatic adult chiari 1 malformations: Experience at Bangabandhu Sheikh Mujib Medical University
Background: The surgical management of symptomatic adult Chiari malformation type 1 (CM1) with or without syringomyelia (SM) continues to be a dilemma considering the outcomes.
Objectives: The study aimed to compare the clinical outcomes between stealth cranioplasty (SC) and one of the most commonly practiced standard procedures, posterior fossa decompression with duraplasty (PFDD). Clinical outcomes between SC and another procedure posterior fossa decompression (PFD) were also compared.
Methods: This comparative cross-sectional study was carried out on 37 males and 16 females symptomatic adult CM1 patients, ranging from 18 to 47 years of age from June 2019 to May 2021. Clinical outcomes were assessed, compared, and analyzed in terms of changes in clinical symptoms and signs, chicago chiari outcome scale (CCOS) score, and occurrence of complications.Â
Results: Of the 53 patients, 23, 19 and 11 underwent SC, PFDD, and PFD, respectively. There were no significant post-operative changes in symptoms and signs among groups except changes in limb weakness between SC and PFDD (P=0.004). Considering average CCOS score, SC performed better only than PFDD (P=0.003), while category-wise SC was better than both PFDD (P=0.004) and PFD (P=0.010). Considering complications, the PFDD group had a significantly higher rate of complications than the SC group (P=0.001), while there was no significant difference in the rate of complications between the PFD and SC groups.
Conclusion: SC was found to have better clinical outcomes than the PFDD and PFD groups as a technique.
Bangabandhu Sheikh Mujib Medical University Journal 2023;16(1): 08-1