scholarly journals JacLy: a Jacobian-based method for the inference of metabolic interactions from the covariance of steady-state metabolome data

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6034
Author(s):  
Mohammad Jafar Khatibipour ◽  
Furkan Kurtoğlu ◽  
Tunahan Çakır
Keyword(s):  
Steady State ◽  
Network Inference ◽  
Jacobian Matrix ◽  
Research Topic ◽  
Small Scale ◽  
Challenging Research ◽  
Metabolic Interactions ◽  
Source Of Information ◽  
Metabolome Data ◽  
Suitable Approximation

Reverse engineering metabolome data to infer metabolic interactions is a challenging research topic. Here we introduce JacLy, a Jacobian-based method to infer metabolic interactions of small networks (<20 metabolites) from the covariance of steady-state metabolome data. The approach was applied to two different in silico small-scale metabolome datasets. The power of JacLy lies on the use of steady-state metabolome data to predict the Jacobian matrix of the system, which is a source of information on structure and dynamic characteristics of the system. Besides its advantage of inferring directed interactions, its superiority over correlation-based network inference was especially clear in terms of the required number of replicates and the effect of the use of priori knowledge in the inference. Additionally, we showed the use of standard deviation of the replicate data as a suitable approximation for the magnitudes of metabolite fluctuations inherent in the system.

Character Reorganization and Categorization using Hybrid Algorithms by Scanned Documents

2019 ◽  
Vol 8 (6S2) ◽  
pp. 943-948
Keyword(s):  
Research Work ◽  
Hybrid Algorithms ◽  
Research Topic ◽  
Image Processing Techniques ◽  
Digital Books ◽  
Otsu Method ◽  
Challenging Research ◽  
Processing Techniques ◽  
Scanned Documents ◽  
Day By Day

Detection and reorganization of text may save a lot of time while reproducing old books text and its chapters. This is really challenging research topic as different books may have different font types and styles. The digital books and eBooks reading habit is increasing day by day and new documents are producing every day. So in order to boost the process the text reorganization using digital image processing techniques can be used. This research work is using hybrid algorithms and morphological algorithms. For sample we have taken an letter pad where the text and images are separated using algorithms. The another objective of this research is to increase the accuracy of recognized text and produce accurate results. This research worked on two different concepts, first is concept of Pixel-level thresholding processing and another one is Otsu Method thresholding.

scholarly journals Obsidian and Obsidian-like Glass Tesserae: A Multidisciplinary Approach to Study the Dedication Wall Mosaic in the Church of St. Mary of the Admiral in Palermo (12th Century)

2020 ◽  
Vol 6 (1) ◽  
pp. 403-416
Author(s):  
Valentina Cantone ◽  
Rita Deiana ◽  
Alberta Silvestri ◽  
Ivana Angelini
Keyword(s):  
Multidisciplinary Approach ◽  
Multispectral Imaging ◽  
Volcanic Glass ◽  
Research Topic ◽  
Multidisciplinary Study ◽  
12Th Century ◽  
Challenging Research ◽  
Byzantine Period ◽  
Dark Glass ◽  
The Church

AbstractPliny the Elder testifies that roman workshops used volcanic glass (obsidian), but also produced and used a dark glass (obsidian-like glass) quite similar to the natural one. In the context of the study on medieval mosaics, the use of the obsidian and obsidian-like tesserae is a challenging research topic. In this paper, we present the results of a multidisciplinary study carried out on the Dedication wall mosaic, realized by a byzantine workshop in the 12th century in the Church of St. Mary of the Admiral in Palermo, and where numerous black-appearing tesserae, supposed to be composed of obsidian by naked-eyes observation, are present. Historical documents, multispectral imaging of the wall mosaic, and some analytical methods (SEM-EDS and XRPD) applied to a sample of black tesserae, concur in identifying here the presence of obsidian and different obsidian-like glass tesserae. This evidence, although related to the apparent tampering and restoration, could open a new scenario in the use of obsidian and obsidian-like glass tesserae during the Byzantine period in Sicily and in the reconstruction of multiple restoration phases carried out between 12th and 20th century AD on the mosaics of St. Mary of the Admiral.

Metal–organic frameworks as catalytic selectivity regulators for organic transformations

2021 ◽  
Author(s):  
Jun Guo ◽  
Yutian Qin ◽  
Yanfei Zhu ◽  
Xiaofei Zhang ◽  
Chang Long ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Metal Organic Frameworks ◽  
Research Topic ◽  
Organic Transformations ◽  
Catalytic Selectivity ◽  
Challenging Research ◽  
Metal Organic

Selective organic transformations using metal–organic frameworks (MOFs) and MOF-based heterogeneous catalysts have been an intriguing but challenging research topic in both the chemistry and materials communities.

The study of mixed assets allocation based on Black–Litterman model

2021 ◽  
pp. 2150022
Author(s):  
Jianwu Lin ◽  
Mengwei Tang ◽  
Jiachang Wang ◽  
Ping He
Keyword(s):  
Stock Market ◽  
Asset Allocation ◽  
Private Equity ◽  
Equity Market ◽  
Research Topic ◽  
Allocation Model ◽  
Quantitative Models ◽  
Challenging Research ◽  
Qualitative Models ◽  
New Type

With Private Funds having a new type of license for asset allocation practice in China, comprehensive asset allocation cross private equity and stock market has received more attention. However, most of the studies focus more on the stock market, and asset allocation models for private equity market that are mainly made based on experience. Thus, the joint allocation of assets crosses both markets making it a challenging research topic. This paper introduces the Black–Litterman model into the private equity market, realizing the transition from qualitative models to quantitative models. It lays a solid quantitative ground for the mixed asset allocation model in both the markets.

Application of a Fuzzy Logic Controller for Speed Control on a Small-Scale Turbojet Engine

2014 ◽  
Author(s):  
Serdar Üşenmez ◽  
Sinan Ekinci ◽  
Oğuz Uzol ◽  
İlkay Yavrucuk
Keyword(s):  
Fuzzy Logic ◽  
Steady State ◽  
Transient Response ◽  
Fuzzy Logic Controller ◽  
Electronic Control Unit ◽  
Small Scale ◽  
Gas Temperature ◽  
Fuel Pump ◽  
Fuel Flow ◽  
Turbojet Engine

Having a small-scale turbojet engine operate at a desired speed with minimum steady state error, while maintaining good transient response is crucial in many applications, such as UAVs, and requires precise control of the fuel flow. In this paper, first the mathematical model of a Small-Scale Turbojet Engine (SSTE) is obtained using system identification tests, and then based on this model, a classical PI controller is designed. Afterwards, to improve on the transient response and steady state performance of this classical controller, a Fuzzy Logic Controller (FLC) is designed. The design process for the FLC employs logical deduction based on knowledge of the engine behavior and iterative tuning in the light of software- and hardware-in-the-loop simulations. The classical and fuzzy logic controllers are both implemented on an in-house, embedded Electronic Control Unit (ECU) running in real time. This ECU is an integrated device carrying a microcontroller based board, a fuel pump, fuel line valves, speed sensor and exhaust gas temperature sensor inputs, and starter motor and glow plug driver outputs. It mainly functions by receiving a speed reference value via its serial communication interface. Based on this reference, a voltage is calculated and applied to the fuel pump in order to regulate the fuel flow into the engine, thereby bringing the engine speed to the desired value. Pre-defined procedures for starting and stopping the engine are also automatically performed by the ECU. Further, it connects to a computer running an in-house comprehensive Graphical User Interface (GUI) software for operating, monitoring, configuration and diagnostics purposes. The designed controllers are used to drive a generic SSTE. Reference inputs consisting of step, ramp and chirp profiles are applied to the controllers. The engine response using both controllers are recorded and inspected. The results show that the FLC exhibits a comparable performance to the classical controller, with possible opportunities to improve this performance.

scholarly journals The influence of small-scale magnetic field on the heating of J0250+5854 polar cap

2021 ◽  
Vol 2103 (1) ◽  
pp. 012034
Author(s):  
D P Barsukov ◽  
A A Matevosyan ◽  
I K Morozov ◽  
A N Popov ◽  
M V Vorontsov
Keyword(s):  
Magnetic Field ◽  
Steady State ◽  
Bound State ◽  
Small Scale ◽  
Polar Cap ◽  
Electron Positron ◽  
Curvature Radiation ◽  
Cap Model ◽  
Star Surface ◽  
Primary Electrons

Abstract The influence of surface small-scale magnetic field on the heating of PSR J0250+5854 polar cap is considered. It is assumed that the polar cap is heated only by reverse positrons accelerated in pulsar diode. It is supposed that pulsar diode is located near the star surface (polar cap model) and operates in the steady state space charge-limited flow regime. The reverse positron current is calculated in the framework of two models: rapid and gradually screening. To calculate the production rate of electron-positron pairs we take into account only the curvature radiation of primary electrons and its absorption in magnetic field. It is assumed that some fraction of electron-positron pairs may be created in bound state that can later be photoionized by thermal photons from star surface.

scholarly journals A theoretical verification of the integral fluctuation theorem for accelerated colloidal systems in the long-time limit

2021 ◽  
Author(s):  
Yash Lokare
Keyword(s):  
Steady State ◽  
Time Scales ◽  
Numerical Study ◽  
Quantitative Description ◽  
Experimental Studies ◽  
Fluctuation Theorem ◽  
Nonequilibrium Steady States ◽  
Small Scale ◽  
Colloidal Systems ◽  
Long Time

A quantitative description of the violation of the second law of thermodynamics in relatively small classical systems and over short time scales comes from the fluctuation-dissipation theorem. It has been well established both theoretically and experimentally, the validity of the fluctuation theorem to small scale systems that are disturbed from their initial equilibrium states. Some experimental studies in the past have also explored the validity of the fluctuation theorem to nonequilibrium steady states at long time scales in the asymptotic limit. To this end, a theoretical and/or purely numerical model of the integral fluctuation theorem has been presented. An approximate general expression for the dissipation function has been derived for accelerated colloidal systems trapped/confined in power-law traps. Thereafter, a colloidal particle trapped in a harmonic potential (generated by an accelerating one-dimensional optical trap) and undergoing Brownian motion has been considered for the numerical study. A toy model of a quartic potential trap in addition to the harmonic trap has also been considered for the numerical study. The results presented herein show that the integral fluctuation theorem applies not only to equilibrium steady state distributions but also to nonequilibrium steady state distributions of colloidal systems in accelerated frames of reference over long time scales.

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