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A modular hybrid simulation framework for complex manufacturing system design
For complex manufacturing systems, the current hybrid Agent-Based Modelling and Discrete Event Simulation (ABM–DES) frameworks are limited to component and system levels of representation and present a degree of static complexity to study optimal resource planning. To address these limitations, a modular hybrid simulation framework for complex manufacturing system design is presented. A manufacturing system with highly regulated and manual handling processes, composed of multiple repeating modules, is considered. In this framework, the concept of modular hybrid ABM–DES technique is introduced to demonstrate a novel simulation method using a dynamic system of parallel multi-agent discrete events. In this context, to create a modular model, the stochastic finite dynamical system is extended to allow the description of discrete event states inside the agent for manufacturing repeating modules (meso level). Moreover, dynamic complexity regarding uncertain processing time and resources is considered. This framework guides the user step-by-step through the system design and modular hybrid model. A real case study in the cell and gene therapy industry is conducted to test the validity of the framework. The simulation results are compared against the data from the studied case; excellent agreement with 1.038% error margin is found in terms of the company performance. The optimal resource planning and the uncertainty of the processing time for manufacturing phases (exo level), in the presence of dynamic complexity is calculated
Access to Mathematics by Blind Students: A Global Problem,
Abstract The issue of blindness and legally blind is becoming a global issue. Based on the last statistics from American Foundation for the blind, there are approximately 10 million blind and visually impaired people in the United States alone. Over 45 million people around the world are completely blind. 180 million more people are legally blind, and approximately 7 million people are diagnosed as blind or legally blind every year. One of the greatest stumbling blocks in the ability of the blind to enter careers in science, technology, engineering or mathematics is the paucity of tools to help them read and write equations. Over the years there have been numerous projects around the world with the goal of building special tools to help the visually impaired student read and write equations. In the current work, we describe some of the most interesting work in this domain and then attempt to make recommendations and/or predictions about the future
Reply to 'Comment on 'Prognostic biomarkers for oral tongue squamous cell carcinoma : a systematic review and meta-analysis''
Non peer reviewe
An application of the finite-discrete element method in the simulation of ceramic breakage: methodology for a validation study for alumina specimens
Alumina (aluminum oxide, Al2O3) particles are pelletised and fired to produce high porosity catalyst pellets of complex shapes. These pellets fill cylindrical reactor columns with particulate packing structures that are key to the in-service performance, but will suffer breakages which impact on catalyst performance. The combined FiniteDiscrete Element Method (FEMDEM) is ideally suited to the simulation of both the multi-body pellet dynamic packing and quasi-static interactions as well as the stress field of each individual pellet, its deformations and fragmentation. The application of FEMDEM fracture modelling to a fine-grained brittle and porous material is novel. This paper presents a methodology for a validation study through comparison with three pointbending and Brazilian tests and discusses FEMDEM's potential in modelling multi-body fragile systems
General Relativistic Contributions in Transformation Optics
One potentially realistic specification for devices designed with
transformation optics is that they operate with high precision in curved
space-time, such as Earth orbit. This raises the question of what, if any, role
does space-time curvature play in determining transformation media?
Transformation optics has been based on a three-vector representation of
Maxwell's equations in flat Minkowski space-time. I discuss a completely
covariant, manifestly four-dimensional approach that enables transformations in
arbitrary space-times, and demonstrate this approach for stable circular orbits
in the spherically symmetric Schwarzschild geometry. Finally, I estimate the
magnitude of curvature induced contributions to satellite-borne transformation
media in Earth orbit and comment on the level of precision required for
metamaterial fabrication before such contributions become important.Comment: 14 pages, 3 figures. Latest version has expanded analysis,
corresponds to published versio
Assessing the effects of drought and temperature on the establishment of Juniperus seravschanica saplings in Northern Oman
Climate change predictions pose a serious threat to the survival and distribution of
Juniperus seravschanica in the northern mountains of Oman. A better understanding of this
species responses to ecological changes is essential, if the potentially harmful effects of
climate change are to be mitigated. One such step is to understand how changes in climate
may influence the growth of juniper saplings. Two and five year old saplings were grown
under different temperatures and watering regimes to determine effects on establishment
and growth. Under an optimum growing temperature, reducing water to 50% and 25% of
the optimal irrigation regime, significantly decreased the growth of juniper saplings. In field
studies, saplings re-introduced to three different altitudinal locations showed varying rates
in establishment success and growth. Both two year old and five year old saplings
established better at higher altitude. Overall, survival rates were considerably better with
transplanting five year old, rather than two year old saplings. Applying irrigation improved
the survival of two-year old stock when grown at the lowest altitude, but rates were not
always significantly different from other treatments. Apical extension growth was found to
be reduced at higher altitude, indicating that temperature is influencing the growth of juniper
saplings. However, it was the combination of drought and high temperatures that reduced
the growth of non-irrigated saplings at lower altitudes. These preliminary results suggest
there is a potential to re-introduce juniper saplings to their natural habitat as part of a
conservation programme, but more time is required to judge the success of the
transplanting initiative when dealing with slow growing trees like juniper
Wavelets and graph -algebras
Here we give an overview on the connection between wavelet theory and
representation theory for graph -algebras, including the higher-rank
graph -algebras of A. Kumjian and D. Pask. Many authors have studied
different aspects of this connection over the last 20 years, and we begin this
paper with a survey of the known results. We then discuss several new ways to
generalize these results and obtain wavelets associated to representations of
higher-rank graphs. In \cite{FGKP}, we introduced the "cubical wavelets"
associated to a higher-rank graph. Here, we generalize this construction to
build wavelets of arbitrary shapes. We also present a different but related
construction of wavelets associated to a higher-rank graph, which we anticipate
will have applications to traffic analysis on networks. Finally, we generalize
the spectral graph wavelets of \cite{hammond} to higher-rank graphs, giving a
third family of wavelets associated to higher-rank graphs
Characterization of tumor antigen peptide-specific T cells isolated from the neoplastic tissue of patients with gastric adenocarcinoma.
Gastric cancer is a significant cause of morbidity and mortality worldwide. Surgical resection remains the primary curative treatment for gastric adenocarcinoma, but the poor (15-35%) survival rate at 5 years has prompted many studies for new therapeutic strategies, such as specific immunotherapy. The aim of this study was to analyze the functional properties of the T cell response to different antigen peptides related to gastric cancer in patients with gastric adenocarcinoma. To this purpose, we have cloned and characterized tumor-infiltrating T cells (TILs) isolated from the neoplastic gastric tissue samples. A T cell response specific to different peptides of gastric cancer antigens tested was documented in 17 out of 20 patients, selected for their HLA-A02 and/or -A24 alleles. Most of the cancer peptide-specific TILs expressed a Th1/Tc1 profile and cytotoxic activity against target cells. The effector functions of cancer peptide-specific T cells obtained from the peripheral blood of the same patients were also studied. The majority of peripheral blood peptide-specific T cells also expressed the Th1/Tc1 functional profile. In conclusion, in most of the patients with gastric adenocarcinoma, a specific type-1 T cell response to gastric cancer antigens was detectable and would have the potential of hamper tumor cell growth. However, in order to get tumor cell killing in vivo, the activity and the number of cancer peptide-specific Th1/Tc1 cells probably need to be enhanced by vaccination with the appropriate cancer antigenic peptides or by injection of the autologus tumor peptide-specific T cells expanded in vitro
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