513 research outputs found
Matrix product states and exactly solvable spin 1/2 Heisenberg chains with nearest neighbor interactions
Using the matrix product formalism, we introduce a two parameter family of
exactly solvable spin 1/2 Heisenberg chains in magnetic field (with
nearest neighbor interactions) and calculate the ground state and correlation
functions in compact form. The ground state has a very interesting property:
all the pairs of spins are equally entangled with each other. Therefore it is
possible to engineer long-range entanglement in experimentally realizable spin
systems on the one hand and study more closely quantum phase transition in such
systems on the other.Comment: 4 pages, RevTex, references added, improved presentation, typos fixe
Exact dimer ground states for a continuous family of quantum spin chains
Using the matrix product formalism, we define a multi-parameter family of
spin models on one dimensional chains, with nearest and next-nearest neighbor
anti-ferromagnetic interaction for which exact analytical expressions can be
found for its doubly degenerate ground states. The family of Hamiltonians which
we define, depend on 5 continuous parameters and the Majumdar-Ghosh model is a
particular point in this parameter space. Like the Majumdar-Ghosh model, the
doubly degenerate ground states of our models have a very simple structure,
they are the product of entangled states on adjacent sites. In each of these
states there is a non-zero staggered magnetization, which vanishes when we take
their translation-invariant combination as the new ground states. At the
Majumdar-Ghosh point, these entangled states become the spin-singlets
pertaining to this model. We will also calculate in closed form the two point
correlation functions, both for finite size of the chain and in the
thermodynamic limit.Comment: 11 page
Analysis of bi-directional piezoelectric-based converters for zero-voltage switching operation
An overview of transparent and translucent 3D-printed façade prototypes and technologies
3D-printing has transformed traditional manufacturing by enabling the fabrication of individually designed complex systems. The building’s façade is one of the most challenging systems because it affects the control of the built indoor environment and allows to provide energy-saving.
The objective of this research is to distinguish 3Dprinting technologies and applied materials in them
that improve transparency in the façade to decrease artificial lighting consumption, to control solar energy, and to improve energy-savings.
A literature study was performed, firstly, different 3Dprinting techniques and their materials for producing transparent outcomes were reviewed from academic databases. Then, transparent 3D-printed façade prototypes were identified.
The outcomes indicated that most of the prototypes used the FDM 3D-printing technique and Polyethylene Terephthalate Glycol as a material. These prototypes didn’t consider the disadvantages of the FDM technique for the lighting transmission. Additionally, some prototypes have control over daylighting discomforts but some of them not. Prototypes tried to improve energy-saving which ranged from applying recyclable materials to controlling solar gain.publishedVersio
Modeling of Whole Genomic Sequencing Implementation using System Dynamics and Game Theory
Biomarker testing is a laboratory test in oncology that is used in the
selection of targeted cancer treatments and helping to avoid ineffective
treatments. There exist several types of biomarker tests that can be used to
detect the presence of particular mutations or variation in gene expression.
Whole Genome Sequencing (WGS) is a biomarker test for analyzing the entire
genome. WGS can provide more comprehensive diagnostic information, but it is
also more expensive than other tests. In this study, System Dynamics and Game
Theoretic models are employed to evaluate scenarios, and facilitate
organizational decision making regarding WGS implementation. These models
evaluate the clinical and economic value of WGS as well as its affordability
and accessibility. The evaluated scenarios have covered the timing of
implementing WGS using time to diagnosis and total cost.Comment: The IISE Annual Conference & Expo 202
An Agent-based model of stem and cancer cell interaction
Advancements in tissue engineering combined with the disease seeking nature of stem cells have provided new grounds for targeted therapy of cancer. However the discrepancies found in existing literature on the role of un-modified stem cells at tumour sites (Klopp et al. 2011), indicates the need for further research.
In vitro approaches provide an insight into actual cell behaviour under given conditions. However these methods are limited by factors such as cost, time and technological advancements in available protocols. In silico tools provide means for quantitative analysis of accumulated data in addition to exploring scenarios and queries otherwise impossible to create in the lab. However these tools can lack in accuracy and realistic correlation with actual biological behaviour. The combination of both in vitro and in silico methods results in a powerful tool that compensates for the limitations of both approaches.
An agent-based model (ABM) is a bottom-up approach that uses information regarding cell behaviour at the single cell level to generate emergent cell population results. Through the development of an agent-based model, the resulting effects of known and hypothesised rules regarding individual cell characteristics and cell-to-cell interactions will be simulated. Where possible, the model rules will be informed and the final model predictions validated using results and observations obtained from cell culture experiments run simultaneously, allowing for a one-to-one mapping of in vitro and in silico results.
Computational modelling coupled with cell culture experiments will provide an insight into the mechanisms behind stem cell and cancer cell interactions, taking us one step closer to using stem cells as a method of cancer treatment
- …