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1.
Article in English | MEDLINE | ID: mdl-37606186

ABSTRACT

The human stomach is a complex organ. Its role is to degrade food particles by using mechanical forces and chemical reactions in order to release nutrients. All ingested items, including our nutrition, should first pass through the stomach, making it arguably the most crucial segment in the gastrointestinal tract. Computational and mathematical modeling of the stomach is an emerging field of biomechanics where several complex phenomena, such as solid mechanics of the gastric wall, gastric electrophysiology, and fluid mechanics of the digesta need to be addressed. Developing a meshfree comprehensive algorithm for solving the nervous stomach model that enables analysing the relationships between these phenomena remains one of the most significant challenges in biomechanics. This research dedicates to study the dynamics of nervous stomach model governed by a mathematical representation depending on three categories viz. Tension (T), Food (F) and Medicine (M), i.e. TFM model. In this regard, a machine learning paradigm, namely POLYnomial WinOwed with Gaussian (PolyWOG) Wavelet Neural Network (PWNN) model has been implemented for handling the non-linear TFM models. We compared the obtained outcomes of present work with results of a well-known numerical computing paradigm and an existing wavelet neural algorithm. Also, we have done statistical assessment studies at different testing points, which reveal that the proposed architecture is effective and accurate.

2.
ISA Trans ; 119: 17-24, 2022 Jan.
Article in English | MEDLINE | ID: mdl-33752885

ABSTRACT

This paper deals with estimation of interval controls for interval Linear Time Invariant (LTI) plants using pole placement technique. Generally, the parameters associated with LTI plant system are assumed to be crisp values, but due to the occurrence of error in experimentation, measurement or due to maintenance induced errors, the parameters are imprecise. As such, the LTI problem reduces to interval LTI. The pole placement problem is then reduced to interval algebraic equation viz. interval Diophantine equation using proper transfer function. Further, the interval Diophantine equation is transformed to Interval System of Linear Equations (ISLE) viz. interval Sylvester matrix equation. Initially, using interval arithmetic an interval algebraic approach has been applied to solve the ISLE for computing non-negative or non-positive controls. Then, another approach using Artificial Neural Network (ANN) is proposed for computing the interval controls. Further, algorithms based on sign function and ANN procedures have been discussed. Finally, the efficiency of the proposed algorithms has been verified using different order interval plants.


Subject(s)
Algorithms , Neural Networks, Computer
3.
Network ; 31(1-4): 142-165, 2020.
Article in English | MEDLINE | ID: mdl-33148086

ABSTRACT

The motivation of this investigation is to develop a single-layer Chebyshev Neural Network (ChNN) model to handle singular fractional (arbitrary)-order Lane-Emden type equations. These equations are well-known application problems of astrophysics and quantum mechanics. Fractional Lane-Emden equations are singular so it is very difficult to solve analytically. Thus, an efficient method is required to handle the above equations. Here, our main aim is to use a single-layer ChNN model for solving fractional Lane-Emden equations. ChNN model is one kind of Functional Link Neural Network (FLNN) in which the hidden layer is replaced by a functional expansion block of the input pattern using orthogonalshifted Chebyshev polynomials (SChP). Thus, the network parameters of ChNN are less than the Multi-Layer Artificial Neural Network (MLANN). We have considered factional-order singular nonlinear problems of astrophysics to show the computational effort of the proposed method. Back Propagation algorithm of the unsupervised version has been considered for minimizing the error function and updating the weights of the ChNN model. Computed results are displayed in terms of tables and graphs.


Subject(s)
Algorithms , Astronomical Phenomena , Mathematical Computing , Neural Networks, Computer , Humans
4.
Nat Commun ; 11(1): 874, 2020 Feb 13.
Article in English | MEDLINE | ID: mdl-32054860

ABSTRACT

Among the perovskite oxide family, KTaO3 (KTO) has recently attracted considerable interest as a possible system for the realization of the Rashba effect. In this work, we report a novel conducting interface by placing KTO with another insulator, LaVO3 (LVO) and report planar Hall effect (PHE) and anisotropic magnetoresistance (AMR) measurements. This interface exhibits a signature of strong spin-orbit coupling. Our experimental observations of two fold AMR and PHE at low magnetic fields (B) is similar to those obtained for topological systems and can be intuitively understood using a phenomenological theory for a Rashba spin-split system. Our experimental data show a B2 dependence of AMR and PHE at low magnetic fields that could also be explained based on our model. At high fields (~8 T), we see a two fold to four fold transition in the AMR that could not be explained using only Rashba spin-split energy spectra.

5.
J Environ Radioact ; 182: 165-171, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29258052

ABSTRACT

Modelling radon transport in the earth crust is a useful tool to investigate the changes in the geo-physical processes prior to earthquake event. Radon transport is modeled generally through the deterministic advection-diffusion equation. However, in order to determine the magnitudes of parameters governing these processes from experimental measurements, it is necessary to investigate the role of uncertainties in these parameters. Present paper investigates this aspect by combining the concept of interval uncertainties in transport parameters such as soil diffusivity, advection velocity etc, occurring in the radon transport equation as applied to soil matrix. The predictions made with interval arithmetic have been compared and discussed with the results of classical deterministic model. The practical applicability of the model is demonstrated through a case study involving radon flux measurements at the soil surface with an accumulator deployed in steady-state mode. It is possible to detect the presence of very low levels of advection processes by applying uncertainty bounds on the variations in the observed concentration data in the accumulator. The results are further discussed.


Subject(s)
Models, Chemical , Radiation Monitoring/methods , Radon/analysis , Soil Pollutants, Radioactive/analysis , Soil/chemistry , Diffusion
6.
Phys Rev Lett ; 116(25): 256402, 2016 Jun 24.
Article in English | MEDLINE | ID: mdl-27391735

ABSTRACT

We studied the electronic and magnetic dynamics of ferromagnetic insulating BaFeO_{3} thin films by using pump-probe time-resolved resonant x-ray reflectivity at the Fe 2p edge. By changing the excitation density, we found two distinctly different types of demagnetization with a clear threshold behavior. We assigned the demagnetization change from slow (∼150 ps) to fast (<70 ps) to a transition into a metallic state induced by laser excitation. These results provide a novel approach for locally tuning magnetic dynamics. In analogy to heat-assisted magnetic recording, metallization can locally tune the susceptibility for magnetic manipulation, allowing one to spatially encode magnetic information.

7.
Neural Comput ; 28(8): 1574-98, 2016 08.
Article in English | MEDLINE | ID: mdl-27348738

ABSTRACT

Hermite polynomial-based functional link artificial neural network (FLANN) is proposed here to solve the Van der Pol-Duffing oscillator equation. A single-layer hermite neural network (HeNN) model is used, where a hidden layer is replaced by expansion block of input pattern using Hermite orthogonal polynomials. A feedforward neural network model with the unsupervised error backpropagation principle is used for modifying the network parameters and minimizing the computed error function. The Van der Pol-Duffing and Duffing oscillator equations may not be solved exactly. Here, approximate solutions of these types of equations have been obtained by applying the HeNN model for the first time. Three mathematical example problems and two real-life application problems of Van der Pol-Duffing oscillator equation, extracting the features of early mechanical failure signal and weak signal detection problems, are solved using the proposed HeNN method. HeNN approximate solutions have been compared with results obtained by the well known Runge-Kutta method. Computed results are depicted in term of graphs. After training the HeNN model, we may use it as a black box to get numerical results at any arbitrary point in the domain. Thus, the proposed HeNN method is efficient. The results reveal that this method is reliable and can be applied to other nonlinear problems too.

8.
Br J Anaesth ; 113(2): 250-7, 2014 Aug.
Article in English | MEDLINE | ID: mdl-25038157

ABSTRACT

In the treatment of severely injured patients, the term 'damage control radiology' has been used to parallel the modern concept of damage control surgery and the allied development of continuous damage control resuscitation from patient retrieval, through all transfers, to appropriate primary treatment. The aims of damage control radiology are (i) rapid identification of life-threatening injuries including bleeding sites, (ii) identification or exclusion of head or spinal injury, and (iii) prompt and accurate triage of patients to the operating theatre for thoracic, abdominal, or both surgeries or the angiography suite for endovascular haemorrhage control. If we are to achieve these aims, patients must have immediate access to modern multidetector computed tomography (MDCT) which is without doubt the most potent weapon in the diagnostic armamentarium. The most severely injured patients are those who have the most to benefit from early diagnosis and life-saving therapies. The traditional teaching that these patients should go immediately to surgery is challenged by technological developments in MDCT and recent clinical evidence.


Subject(s)
Anesthesia , Multidetector Computed Tomography/methods , Wounds and Injuries/diagnostic imaging , Hemorrhage/diagnostic imaging , Hemorrhage/etiology , Humans , Multidetector Computed Tomography/statistics & numerical data , Tomography, X-Ray Computed , Trauma Centers , Ultrasonography
9.
ScientificWorldJournal ; 2014: 485737, 2014.
Article in English | MEDLINE | ID: mdl-24977198

ABSTRACT

This paper presents the machine learning based machine translation system for Hindi to English, which learns the semantically correct corpus. The quantum neural based pattern recognizer is used to recognize and learn the pattern of corpus, using the information of part of speech of individual word in the corpus, like a human. The system performs the machine translation using its knowledge gained during the learning by inputting the pair of sentences of Devnagri-Hindi and English. To analyze the effectiveness of the proposed approach, 2600 sentences have been evaluated during simulation and evaluation. The accuracy achieved on BLEU score is 0.7502, on NIST score is 6.5773, on ROUGE-L score is 0.9233, and on METEOR score is 0.5456, which is significantly higher in comparison with Google Translation and Bing Translation for Hindi to English Machine Translation.


Subject(s)
Algorithms , Natural Language Processing , Neural Networks, Computer , Pattern Recognition, Automated/methods , Semantics , Translating , Vocabulary, Controlled , England , India , Quantum Theory , United States
10.
ScientificWorldJournal ; 2014: 308205, 2014.
Article in English | MEDLINE | ID: mdl-24790562

ABSTRACT

This paper proposes a new technique based on double parametric form of fuzzy numbers to handle the uncertain vibration equation for very large membrane for different particular cases. Uncertainties present in the initial condition and the wave velocity of free vibration are modelled through Gaussian convex normalised fuzzy set. Using the single parametric form of fuzzy number, the original fuzzy vibration equation is converted first to an interval fuzzy vibration equation. Next this equation is transformed to crisp form by applying double parametric form of fuzzy numbers. Finally the same governing equation is solved by Adomian decomposition method (ADM) symbolically to obtain the uncertain bounds. The present methods are very simple and effective. Obtained results are depicted in terms of plots to show the efficiency and powerfulness of the present analysis. Results obtained by the methods with new techniques are compared with existing results in special cases.


Subject(s)
Models, Theoretical , Uncertainty , Vibration , Algorithms
12.
Clin Radiol ; 68(10): 1065-9, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23810694

ABSTRACT

AIM: To describe the initial pilot phase of the 2009 Scottish Audit of Surgical Mortality (SASM), which includes outcomes and difficulties that arose during any interventional radiology (IR) procedure performed on patients in this audit over an 18 month period. MATERIALS AND METHODS: Approximately 40 consultant interventional radiologists from all units in Scotland elected to participate in the audit. Each response was then peer reviewed after anonymisation of the patient and institution. If a relevant ACON (area for consideration or area of concern) was generated, this was checked by one of the other reviewers before communication with the original reporting radiologist and colleagues. There was then a right of reply by the reporting unit before formal documentation was sent out. RESULTS: Initial results were analysed after 18 months period, during which time 95 forms relating to deaths of surgical inpatients were sent to interventional radiologists identified as having been involved in an IR procedure at some time during the patient's admission. Seventy-one forms had been returned by July 2010, of which 46 had gone through the entire SASM process. From these, 10 ACONs were attributed. Anonymised case vignettes and reports from these were used as educational tools. CONCLUSION: Involvement with SASM is a useful process. Significant safety issues and learning points were identified in the pilot. The majority of ACONs identified by the audit were in patients who had undergone percutaneous biliary interventions.


Subject(s)
Radiography, Interventional/mortality , Surgical Procedures, Operative/mortality , Female , Humans , Male , Pilot Projects , Scotland/epidemiology
13.
Scott Med J ; 56(2): 61-3, 2011 May.
Article in English | MEDLINE | ID: mdl-21670128

ABSTRACT

The Royal College of Radiologists (RCR) published guidelines in 2003 which aimed to standardise and improve the safety of sedation in the modern Radiology department. As sedation requirements increase, we decided to audit our own departments understandings and practice with respect to sedation. A repeat audit cycle was performed following a re-educational lecture, one year later. Three common sedation case scenarios were incorporated into a questionnaire which detailed questioning on requirements for fasting, monitoring and the order and use of sedation drugs alongside analgesics. These were compared to the 2003 RCR guidelines. The audit was recycled at one year. Despite the RCR guidelines, freely available on the RCR website, there was a persisting variation in practice which revealed a lack of awareness of the requirements for adequate fasting and the importance of giving the opiate before the benzodiazepine (sedative) agent in cases where a combination are chosen. The audit did show a trend towards using shorter acting benzodiazepines, which is in keeping with the guidelines. Monitoring of vital signs was generally, well carried out. General awareness of the RCR guidelines for safe sedation in the Radiology department was initially low and practice found to be variable. Re-education saw some improvements but also, some persisting habitual deviations from the guidelines, particularly with respect to the order in which the opiate and sedative benzodiazepine were given.


Subject(s)
Guideline Adherence , Hypnotics and Sedatives/therapeutic use , Practice Guidelines as Topic , Radiology/methods , Radiology/standards , Aged, 80 and over , Benzodiazepines/therapeutic use , Clinical Audit , Fasting , Female , Humans , Male , Middle Aged , Societies, Medical , Surveys and Questionnaires , United Kingdom
15.
Eur J Vasc Endovasc Surg ; 37(2): 198-205, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19046905

ABSTRACT

BACKGROUND: We sought to evaluate the role of balloon angioplasty as the primary modality in the management of vein graft stenoses. METHODS: Patients who underwent infrainguinal vein graft bypass from January 2002 to December 2007 were enrolled into a surveillance program. Grafts which developed critical stenoses were identified and underwent urgent angiography with a view to angioplasty of the stenotic lesion. Lesions which were deemed unsuitable for angioplasty underwent urgent surgical repair. RESULTS: Four hundred and eleven grafts were followed up for a median of 19 months (range: 2-61). Ninety-six grafts (22.6%) developed critical stenosis. Twelve grafts occluded prior to repair and one was not intervened upon electively. Eight grafts underwent primary surgical repair. Seventy-six grafts underwent 99 endovascular procedures. Technical success was achieved in 60 grafts (78.9%). Of the grafts in which technical success had not been achieved, eight underwent repeat angioplasty and three were surgically repaired. Twenty-four grafts underwent repeat angioplasty for re-stenosis with a technical success rate of 71%. No difference was observed in graft patency (P=0.08) or amputation rates (P=0.32) between the grafts requiring intervention to maintain patency, and grafts which did not. Smoking [OR: 2.61 (95% CI: 1.51-4.53), (P=0.006)], diabetes [OR: 2.55 (95% CI: 1.49-4.35), (P=0.006)], renal failure [OR: 1.89 (95% CI: 1.19-3.38), (P=0.040)] and recurrent stenosis [OR: 3.22 (95% CI: 1.63-4.69), (P<0.001)] were risk factors for graft occlusion. CONCLUSIONS: Balloon angioplasty of failing infrainguinal vein bypass grafts is safe and can be performed with an acceptable medium term patency rate, albeit with a significant risk of re-stenosis which can be successfully treated in most patients using repeat endovascular intervention.


Subject(s)
Angioplasty, Balloon , Graft Occlusion, Vascular/therapy , Saphenous Vein/transplantation , Adult , Aged , Aged, 80 and over , Amputation, Surgical , Angiography, Digital Subtraction , Constriction, Pathologic , Diabetes Complications/etiology , Diabetes Complications/therapy , Female , Graft Occlusion, Vascular/etiology , Graft Occlusion, Vascular/pathology , Graft Occlusion, Vascular/surgery , Humans , Male , Middle Aged , Odds Ratio , Recurrence , Renal Insufficiency/complications , Reoperation , Risk Assessment , Risk Factors , Smoking/adverse effects , Time Factors , Treatment Outcome , Ultrasonography, Doppler, Duplex , Vascular Patency
16.
J Vasc Access ; 9(4): 293-5, 2008.
Article in English | MEDLINE | ID: mdl-19085901

ABSTRACT

There are various non-invasive or minimally invasive techniques for management of pseudoaneurysms including ultrasound guided compression, ultrasound guided thrombin injection and covered stent placement. We report a case where a covered stent graft was successfully used for the treatment of a pseudoaneurysm directly arising from a PTFE graft which recurred 3 months following treatment with ultrasound guided thrombin injection.


Subject(s)
Aneurysm, False/therapy , Arteriovenous Shunt, Surgical/adverse effects , Blood Vessel Prosthesis Implantation/adverse effects , Blood Vessel Prosthesis , Coagulants/administration & dosage , Stents , Thrombin/administration & dosage , Ultrasonography, Interventional , Aneurysm, False/etiology , Aneurysm, False/pathology , Balloon Occlusion , Blood Vessel Prosthesis Implantation/instrumentation , Female , Femoral Artery/surgery , Femoral Vein/surgery , Humans , Injections, Intralesional , Middle Aged , Polytetrafluoroethylene , Prosthesis Design , Recurrence , Renal Dialysis , Reoperation , Treatment Failure
17.
Cardiovasc Intervent Radiol ; 31 Suppl 2: S45-7, 2008 Jul.
Article in English | MEDLINE | ID: mdl-17763900

ABSTRACT

Persistent sciatic artery is a rare congenital anomaly. It is associated with increased incidence of aneurysmal dilatation, thrombosis, distal embolization, and atherosclerotic change. We describe the case of a patient with persistent sciatic artery who presented with a critically ischemic left leg as a result of an occluded left common iliac artery, which was treated by angioplasty and stenting, and discuss the endovascular iliac recanalization in the presence of a persistent sciatic artery.


Subject(s)
Angioplasty, Balloon , Arterial Occlusive Diseases/therapy , Arteriovenous Malformations/therapy , Iliac Artery , Leg/blood supply , Stents , Angiography , Arterial Occlusive Diseases/diagnostic imaging , Arteriovenous Malformations/diagnostic imaging , Female , Humans , Middle Aged
19.
Cardiovasc Intervent Radiol ; 30(5): 1013-5, 2007.
Article in English | MEDLINE | ID: mdl-17533537

ABSTRACT

This report describes the case of an early postoperative anastomotic leak following elective open repair of an infrarenal abdominal aortic aneurysm which was successfully treated by endovascular stent-grafting. A 71-year-old man underwent open tube graft repair of abdominal aortic aneurysm. Twelve days later he presented with a contained leak from the distal anastomosis, which was confirmed on CT scan. This was successfully treated with a bifurcated aortic stent-graft. This case illustrates the usefulness of the endovascular approach for resolving this rare surgical complication of open repair of abdominal aortic aneurysm and the challenges associated with the deployment of such a device within an aortic tube graft.


Subject(s)
Aortic Aneurysm, Abdominal/surgery , Blood Vessel Prosthesis Implantation/instrumentation , Blood Vessel Prosthesis , Postoperative Complications/surgery , Stents , Aged , Anastomosis, Surgical , Aortic Aneurysm, Abdominal/diagnostic imaging , Aortic Aneurysm, Abdominal/physiopathology , Aortography , Humans , Male , Reoperation , Tomography, X-Ray Computed , Treatment Outcome
20.
Cardiovasc Intervent Radiol ; 30(5): 1029-32, 2007.
Article in English | MEDLINE | ID: mdl-17497070

ABSTRACT

This report describes the case of a ruptured mycotic aneurysm of the left common iliac artery, successfully treated with endovascular stent-grafting. A 64-year-old woman underwent diagnostic coronary angiography complicated by an infected hematoma of the left groin. Seven days later, she developed methicillin-resistant Staphylococcus aureus septicemia and CT scan evidence of perivascular inflammation around the left common iliac artery. This was followed by rupture of a mycotic aneurysm of the left common iliac artery. The lesion was successfully treated with a stent-graft and prolonged antibiotic therapy, and the patient remains free of infection 10 months later. Accumulating evidence suggests that endovascular repair can be used safely for the repair of ruptured infected aneurysms.


Subject(s)
Aneurysm, Infected/therapy , Blood Vessel Prosthesis Implantation/instrumentation , Blood Vessel Prosthesis , Coronary Angiography/adverse effects , Embolization, Therapeutic , Iliac Aneurysm/therapy , Staphylococcal Infections/therapy , Stents , Aneurysm, Infected/diagnostic imaging , Aneurysm, Infected/drug therapy , Aneurysm, Infected/etiology , Aneurysm, Infected/surgery , Angiography, Digital Subtraction , Anti-Bacterial Agents/therapeutic use , Combined Modality Therapy , Female , Humans , Iliac Aneurysm/diagnostic imaging , Iliac Aneurysm/drug therapy , Iliac Aneurysm/etiology , Iliac Aneurysm/surgery , Methicillin Resistance , Middle Aged , Minimally Invasive Surgical Procedures , Rupture , Staphylococcal Infections/diagnostic imaging , Staphylococcal Infections/drug therapy , Staphylococcal Infections/etiology , Staphylococcal Infections/surgery , Tomography, X-Ray Computed , Treatment Outcome
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