Personal Identification using the Distance and Triangle between the Metacarpophalangeal Joints

Personal identification using the distance among the metacarpophalangeal joints (MCPs) was presented in this study. The system was developed to specify the dorsal hand patterns. Firstly, the dorsal hand images were taken for the subjects via an infrared camera. Secondly, the dorsal hand images were converted to grayscale and binary images using image processing techniques. After that, the distance of the MCPs was measured by various the dorsal hand images including index to middle, middle to ring, ring to little, and index to little of the dorsal hand. In addition, the triangle areas between index to middle, middle to ring, ring to little, and index to little of the dorsal hand were used to specify the dorsal hand patterns. The result of the distance and the triangle area of the MCPS can be used to identify a person because of the difference of distance and the triangle area of the MCPs of each person.

New insights into human occupation through rock art at Khatm al Melaha archaeological site (Sharjah, United Arab Emirates)

This paper is an approach to the study and documentation of a quite large group of rock art boulders at Khatm al Melaha (Sharjah, United Arab Emirates). More than 150 decorated stone blocks, with almost 400 motifs, have been identified on a hill close to the Arabian Sea coast, highlighting its importance as a control point for communicating the coast and the hinterland. Although a domestic human occupation of the area has not yet been documented, the symbolic significance of this place is reinforced not only by rock art but also by the presence of several dry-stone tombs. Despite the limited studied area, our contribution outlines a preliminary approach to a previously very little studied territory, providing a local chrono-stylistic proposal for those figurative (humans, animals) and non-figurative (signs) engravings attending to different stylistic conventions, techniques, subject matters and varnish colour. Different digital documentation techniques (digital tracings, terrestrial and aerial photogrammetry, web mapping) have been applied in order to create an updated and accurate data corpus allowing future analysis. The ongoing research will try to find new evidence of symbolic occupation of the territory in relation to human settlements and their relationship within a wider landscape

A framework for intracranial saccular aneurysm detection and quantification using morphological analysis of cerebral angiograms

Reliable early prediction of aneurysm rupture can greatly help neurosurgeons to treat aneurysms at the right time, thus saving lives as well as providing significant cost reduction. Most of the research efforts in this respect involve statistical analysis of collected data or simulation of hemodynamic factors to predict the risk of aneurysmal rupture. Whereas, morphological analysis of cerebral angiogram images for locating and estimating unruptured aneurysms is rarely considered. Since digital subtraction angiography (DSA) is regarded as a standard test by the American Stroke Association and American College of Radiology for identification of aneurysm, this paper aims to perform morphological analysis of DSA to accurately detect saccular aneurysms, precisely determine their sizes, and estimate the probability of their ruptures. The proposed diagnostic framework, intracranial saccular aneurysm detection and quantification, first extracts cerebrovascular structures by denoising angiogram images and delineates regions of interest (ROIs) by using watershed segmentation and distance transformation. Then, it identifies saccular aneurysms among segmented ROIs using multilayer perceptron neural network trained upon robust Haralick texture features, and finally quantifies aneurysm rupture by geometrical analysis of identified aneurysmic ROI. De-identified data set of 59 angiograms is used to evaluate the performance of algorithms for aneurysm detection and risk of rupture quantification. The proposed framework achieves high accuracy of 98% and 86% for aneurysm classification and quantification, respectively

Cavitation inception of a van der Waals fluid at a sack-wall obstacle

Cavitation in a liquid moving past a constraint is numerically investigated by means of a free-energy lattice Boltzmann simulation based on the van der Waals equation of state. The fluid is streamed past an obstacle and, depending on the pressure drop between inlet and outlet, vapor formation underneath the corner of the sack-wall is observed. The circumstances of cavitation formation are investigated and it is found that the local bulk pressure and mean stress are insufficient to explain the phenomenon. Results obtained in this study strongly suggest that the viscous stress, interfacial contributions to the local pressure, and the Laplace pressure are relevant to the opening of a vapor cavity. This can be described by a generalization of Joseph's criterion that includes these contributions. A macroscopic investigation measuring mass flow rate behavior and discharge coefficient was also performed. As theoretically predicted, mass flow rate increases linearly with the square root of the pressure drop. However, when cavitation occurs, the mass flow growth rate is reduced and eventually it collapses into a choked flow state. In the cavitating regime, as theoretically predicted and experimentally verified, the discharge coefficient grows with the Nurick cavitation number

Multipseudopotential interaction : a lattice Boltzmann scheme for simulation of multiphase flows

In this study, a new pseudopotential Lattice Boltzmann (LB) scheme, multipseudopotential interaction (MPI), including boundary conditions is proposed for simulation of two-phase flows. It solves several drawbacks of available schemes such as being thermodynamically inconsistent with practical equations of state (EOSs), being limited to low-density ratios, not having an independently tunable interface width. The lattice interaction potential is described by a series of consistent sub-potentials. In theory, in addition to being intrinsically consistent with thermodynamics, the MPI-LB scheme is stable for a large range of density ratios (up to 106), and tunable for interface width. In engineering applications, the scheme is superior over the previous schemes of reproducing practical EOSs by removing the deficiency of creating unphysical potentials. The scheme is unlimited to implement the practical EOSs which can be expressed in a polynomial format. The scheme is studied and verified regarding liquid vapour circular and flat interfaces, Laplace law, Galilean invariance, and change of viscosity. Furthermore, the scheme is investigated for the effects of different wall boundary conditions on the hydrodynamics of non-ideal single-phase fluids. The suitable boundary condition is chosen based on density variation across the channel, and errors because of domain resolution, relaxation time, and compressibility

Mechanism of ischemic stroke in patients with middle cerebral artery stenosis.

Gao Shan.Thesis (M.Phil.)--Chinese University of Hong Kong, 2002.Includes bibliographical references (leaves 191-194).Abstracts in English and Chinese.Abstract in English --- p.iAbstract in Chinese --- p.iiiAcknowledgement --- p.vIntroduction --- p.viContents --- p.viiiList of tables --- p.xivList of figures --- p.xvChapter Chapter One --- Literature ReviewChapter 1.1 --- Middle Cerebral Artery (MCA) Stenos --- p.isChapter 1.1.1 --- Prevalence of atherosclerotic MCA stenosis --- p.2Chapter 1.1.2 --- Methods for diagnosis of MCA stenosis --- p.3Chapter 1.1.3 --- Possible mechanism and course of stroke with MCA stenosis --- p.4Chapter 1.1.4 --- Treatment and prevention of stroke in patients with MCA stenosis --- p.5Chapter 1.2 --- Microembolic Signal (MES) DetectionChapter 1.2.1 --- Introduction --- p.9Chapter 1.2.2 --- Technology --- p.9Characteristics of MESFactors that affect MES detectionProblems of technologyChapter 1.2.3 --- Clinical application --- p.15MES originating from atherosclerotic carotid artery stenosisMES detection in internal carotid endarterectomy (CEA)MES detection in patients with MCA stenosisPredicting value and application in therapeutic trialReferences --- p.19Chapter Chapter Two --- General MethodologyChapter 2.1 --- Transcranial Doppler (TCD) Diagnosis for Intracranial Artery StenosisChapter 2.1.1 --- TCD spectrum and common parameters --- p.29Chapter 2.1.2 --- Emitting and receiving transducers --- p.29Chapter 2.1.3 --- Pulsitility index (PI) --- p.31Chapter 2.1.4 --- Insonation depth and flow direction --- p.31Chapter 2.1.5 --- Continuous wave (CW) and pulsed wave (PW) --- p.33Chapter 2.1.6 --- Normal intracranial arteries through temporal and suboccipital window --- p.33Chapter 2.1.7 --- Normal intracranial arteries through orbital window --- p.36Chapter 2.1.8 --- Normal extracranial arteries --- p.36Chapter 2.1.9 --- TCD diagnosis for intracranial artery stenosis --- p.39Chapter 2.1.10 --- Example of multiple intracranial arteries stenosis --- p.39Chapter 2.2 --- Microembolic Signal (MES) DetectionChapter 2.2.1 --- Device of MES monitoring --- p.41Chapter 2.2.2 --- Insonated artery and depth --- p.41Chapter 2.2.3 --- Axis length of the sample volume --- p.43Chapter 2.2.4 --- Fast Fourier Transform (FFT) time window overlap --- p.43Chapter 2.2.5 --- Distinguishing embolic signal and artifact with two-gate transducer --- p.45Chapter 2.2.6 --- Measurements of embolic signal and threshold --- p.47References --- p.45Chapter Chapter Three --- Prevalence and Clinical Significance of Microembolic Signal (MES) in Patients with Middle Cerebral Artery (MCA) StenosisChapter 3.1 --- Abstract --- p.50Chapter 3.2 --- Introduction --- p.51Chapter 3.3 --- Methodology --- p.51PatientsSeverity of stroke and clinical courseDiagnosis for middle cerebral artery (MCA) stenosisMicroembolic signal (MES) detectionStatistical analysisChapter 3.4 --- Results --- p.55Baseline information of patientsPrevalence of MESRelationship between presence of MES and severity of MCA stenosisCorrelation between presence of MES and clinical course in 85 symptomatic patientsCorrelation between the count of MES and clinical course in 85 symptomatic patientsCorrelation between the presence of MES and further ischemic strokeChapter 3.5 --- Discussion --- p.63Prevalence of MESAssociation between severity of stroke and presence or the number of MESPredictive value of MES for further strokeReferences --- p.66Chapter Chapter Four --- Mechanisms of Acute Cerebral Infarction in Patients with Cerebral Artery Stenosis: a Diffusion-weighted Imaging and Microemboli Monitoring studyChapter 4.1 --- AbstractChapter 4.2 --- Introduction --- p.72Chapter 4.3 --- Methodology --- p.73PatientsMicroembolic signal (MES) detection by transcranial Doppler (TCD)"Magnetic resonance imaging (DWI, MRI and MRA)"Statistical analysisChapter 4.4 --- Results --- p.77Severity of MCA stenosis on MRA and pattern of infarct on DWIFrequency and count of MES and its relationship with multiple and borderzone infarction on DWIChapter 4.5 --- Discussion --- p.79Frequency of MESPattern of cerebral infarcts on DWIRelationship between MES and multiple infarcts on DWIReferences --- p.83Chapter Chapter FiveChapter Chapter Five-I --- Novel Observations of the Characteristics of Real Time Genesis of Thromboembolism in Middle Cerebral Artery Stenosis Detected by Transcranial DopplerChapter 5.1.1 --- Abstract --- p.90Chapter 5.1.2 --- Introduction --- p.91Chapter 5.1.3 --- Methodology --- p.91Characteristics of patients"MRA, DWI and conventional TCD data"MES monitoring method and overall dataNeuroimaging and MES monitoring data in all five patientsSignal analysis in off-lineConfirmation test for the origin of MESChapter 5.1.4 --- Results --- p.104Frequency of three special phenomenaCharacteristics of three special phenomenaResults of confirmation test for embolic sourceChapter 5.1.5 --- Discussion --- p.133Occurrence of MES with flow velocity change simultaneouslyMES splatterBi-directional low frequency (S-velocity) vibrationTesting for source of MES detected from MCA stenosisReferences --- p.139Chapter Chapter Five-II --- Characteristics of Microembolic Signals Detected near Its Origin from the Middle Cerebral Artery StenosisChapter 5.2.1 --- Abstract --- p.143Chapter 5.2.2 --- Introduction --- p.144Chapter 5.2.3 --- Methodology --- p.144PatientsMicroembolic signal (MES) detectionClassification of MESChapter 5.2.4 --- Results --- p.145Types of MES detected from MCA stenosisCharacteristics of three types of MESChapter 5.2.5 --- Discussion --- p.157Emboli moving from vessel wall to the centerEmboli vibrationAbout calculating the time delay between two channelsReferences --- p.160Chapter Chapter Five-III --- "Hemodynamic change,microembolic signal counts and use of antithrombotic treatments"Chapter 5.3.1 --- Abstract --- p.163Chapter 5.3.2 --- Introduction --- p.164Chapter 5.3.3 --- Methodology --- p.164Chapter 5.3.4 --- Results"The relationship among flow velocity, the number of MES and time since symptom onset" --- p.165Patient onePatient twoPatient threeChapter 5.3.5 --- DiscussionAssociation between flow velocity or MES change and different anticoagulants in acute stageProgression of MCA stenosis after acute stageStability of MCA atherosclerotic stenosisReferences --- p.173Chapter Chapter Six --- The Optimal Values of Flow Velocity on Transcranial Dopplerin Grading Severity of Middle Cerebral Artery Stenosis in Comparison With Magnetic Resonance AngiographyChapter 6.1 --- Abstract --- p.179Chapter 6.2 --- Introduction --- p.180Chapter 6.3 --- Methodology --- p.180PatientsTCD examinationGrading of MCA stenosis on MRAStatistical analysisChapter 6.4 --- Results --- p.182Detection of >50% MCA stenosis according to flow velocityGrading severity of MCA stenosis by flow velocityChapter 6.5 --- Discussion --- p.186Reliability of TCD diagnosis for MCA stenosisGrading MCA stenosis according to flow velocity on TCDReferencesAbbreviations --- p.189Publications --- p.19

Computational Characterization of Nonwoven Fibrous Materials: Transport and Wetting Properties

Nonwoven fibrous materials represent a platform of flexible material substrates. Nonwovens are widely used in the production of napkins, paper, filters, wound covers and face masks. In addition, for many applications, nonwoven materials interact with fluids. For example, in filtration applications, nonwoven materials are used to clean fluids containing solid particles or emulsified droplets. The filtration performance is affected not only by the geometrical arrangement of fibers in non-woven materials but also wettability of fibers. Understanding the transport properties of nonwoven materials and interactions between the dispersed droplets and solid substrate is crucial for the design and optimization of filter media. The present work is focused on: (1) obtaining pore space information from 3D structure in nonwoven media and 2) predicting the liquid transport properties in fibrous materials, including permeability and tortuosity (3) investigating droplet morphology on fibers. Chapters 1-3 provide the basis of fiber-liquid interactions and introduce the lattice Boltzmann method (LBM). Chapter 4 deals with characterization of microstructures generated from 3D reconstructed plywood and random oriented fibrous media. An algorithm based on watershed segmentation is utilized to extract pore network information including: pore diameter, throat diameter and connectivity. The effect of fiber overlapping arrangements, fiber radius and porosity on the pore space morphology was explored by statistical pore-network analysis. A thorough analysis of the correlation between effective geometrical properties and mean pore size, demonstrated that randomness on microscopic level can have a significant effect on the macroscopic properties of the fibrous media. In Chapter 5, simulations on pore-scale single phase fluid flow through fibrous media using the lattice Boltzmann method were performed. From the simulated flow field, permeability and tortuosity of nonwoven fibrous materials can be evaluated over a wide range of porosity 0.1 \u3c φ \u3c 0.9. The validity of Darcy’s law which describes the flow behavior through a porous medium was confirmed in the studied porosity regime. The simulation results were used to test the accuracy of semi-empirical scaling relations, that enabled predictions in trans-plane permeability and tortuosity based on porosity and specific surface area. Chapter 6 deals with the wetting and capillarity effects of droplets deposited on a single fiber. A multicomponent pseudopotential lattice Boltzmann model was applied to study the interface dynamics of droplets and wetting/dewetting behavior. By adopting different initial droplet configurations, we studied the stability of barrel-shaped and clam-shell droplets on a single fiber for contact angles ranging from 10° to 68°. The simulated barrel drop profile was validated with experimental results. The morphology diagram established from simulations showed that both barrel and clam-shell configurations are stable in coexistence. Dr. Ulf Schiller introduced me to the LBM, and guided my research described in Chapter 3-5. These chapters are based on publications [1, 2, 3], but significantly modified to include additional materials that has never been published. Chapter 6 has been developed to explain recent experimental results obtained in Dr. Kornev’s group. The developed simulation protocol revealed new physics related to the classical problem of fiber-drop interactions and a new diagram of morphological transitions of droplets on fibers was determined. The numerical simulations and data analysis were carried out on Palmetto high-performance computing (HPC) cluster

A mud design to improve water-based drilling in clay rich formation

This research was initiated to design a water based mud that can keep its functionality in deep intervals or shaly formations where conventional additives lose their functionality. In this study a WBM designed using two green surfactants that not only provide good rheology and filtration control under normal drilling conditions, but also prevents shale swelling in complex geological formations