161 research outputs found
Method of Moment Analysis of Partially Shielded Chiral Bodies of Revolution
A chiral body of revolution (BOR) which is partially covered by a thin conducting shield is analyzed using the method of moments (MOM). The axisymmetric system is excited by a plane wave. The total internal fields and the far scattered fields are computed. The problem is solved using the surface equivalence principle. The scattered fields outside the structure are assumed to be produced by an equivalent magnetic surface current that exists on the unshielded part of the BOR surface and an external equivalent electric surface current that exists over all of the BOR surface . These two currents are assumed to radiate in the unbounded external medium. Similarly, the total internal fields are assumed to be produced by the negative of the above magnetic current and an internal equivalent electric surface current that exists over all of the BOR surface, but is the negative of an independent unknown only on the shielded part of . These two currents radiate in the unbounded internal medium. Enforcing continuity of the tangential components of total electric field (E) and total magnetic field (H) on S gives a two coupled integral equations for the two unknown surface currents. The two unknown surface currents are the external equivalent electric surface current and the union of magnetic current ( ) on the unshielded part of and the negative of the internal equivalent electric surface current on the shielded part of . The method of moments as applied to bodies of revolution is used to solve these integral equations numerically. Piecewise linear variation of the currents is assumed along the generating curve of the BOR. The variation of the currents along the circumferential direction is represented by Fourier series. An approximate Galerkin\u27s method is used for testing. Conical and spherical BORs are studied. Computed results for the partially shielded spherical chiral body are in excellent agreement with other data.
Theoretical framework developed in chapters two through six factually validated the underlying firm foundation of mathematical physics and sound computational electromagnetic methods of our theory by producing correct scattered fields and radar cross sections of the chiral and perfectly conducting sphere, chiral and perfectly conducting cylinder, chiral and perfectly conducting cone. Chapter seven demonstrates the soundness of the theoretical foundation of this thesis by producing computed results and graphs of not only the case of a perfectly conducting sphere, cylinder and cone but those of the chiral sphere, chiral cylinder, and chiral cone and those of the chiral sphere, chiral cylinder and chiral cone partially covered by rotationally symmetric perfectly conducting surface. The computed results and graphs obtained in chapter seven by the application of our theoretical framework were almost one hundred percent accurate with respect to the conformability of our graph mappings, form of our graphs and accuracy of our graph readings with respect to analytically calculated results and graphs. Our computed results and graphs with respect to the computed results and graphs of early research works that used numerical approach distinctly different than ours were in good agreement
Students’ Precedence of Attributes Related Online Management Education – A RIDIT Approach
This paper sheds light in understanding the effectiveness of online management education by ranking the priority, perception and preference shown by students while they are considering online management education. The students’ precedence of attributes which are in favor and also against the online management education was considered.The ranking of student’s preference and priority of attributes related to online management education was measured and analyzed by RIDIT approach and was inferred that major advantages of online management education includes convenience in performing group assignments, assessments and group projects. Respondents also felt that the quality of courses and pedagogy in online management courses is superior and the Collaborative and interactive learning and teaching were also considered a benefit of performing online management education. However the major limitations related to online management education were found to be No proper accreditation and certification, No recognition by university or education board and also the credibility of exams, assessments and evaluation system was also skeptical. This paper helps in understanding the areas in which the online management education can enhance its favorable features and thereby overcoming its restrictions and increasing the quality of course delivery by using an innovative digital platform. Keywords: Accreditation, Certification, Collaborative learning, Digital platform, Group Assignments, Online Management education, Pedagogy, RIDIT Analysis
Parkinson’s Disease and Forced Exercise: A Preliminary Study
Objective. The concept of forced exercise has drawn attention for the treatment of Parkinson’s disease symptoms with anecdotal reports of success. This study sought to ascertain any significant effect of forced exercise using a motorized stationary bicycle when compared to controls on Parkinson’s disease symptoms in a blinded, randomized, and controlled setting. Setting. Parkinson’s disease outpatient clinic, Veterans Administration Medical Center. Method. We assessed 23 patients (13 experimental and 10 controls) on a number of standard Parkinson’s measures at baseline, after participation in eight weeks of twice weekly forced exercise or eight weeks of conventional clinic care, and then after a three-month period had elapsed. Dependent measures were UPDRS-III, Berg Balance Scale, finger taping test, and the PDQ-39. Results. Results did not demonstrate any main effect differences between the exercise and control groups on any measure at any point in time. A within subjects effect was demonstrated for the forced exercise group on overall UPDRS-III scores at the three-month end point. No other within group effects were noted. Results suggest that early enthusiasm for forced exercise may need tempering. Limitations of the study are discussed as well as numerous logistical challenges to this type of study
Caregiver distress in parkinsonism
This study examined the frequency and degree of caregiver burden in persons with parkinsonism, a group of disorders with four primary symptoms that include tremor, rigidity, postural instability, and bradykinesia. We assessed associations between perceived caregiver burden and physical, cognitive, and functional impairments using well-established tools for persons with parkinsonism. The 49 individuals with parkinsonism ranged in age from 61 to 87 (mean = 75), while their caregivers (N = 49) ranged in age from 48 to 83 (mean = 70). The caregivers were predominantly either wives (82%) or daughters (6%), with other family members, friends, and/or neighbors (12%) making up the rest. The caregivers reported a relatively high ability for coping (mean scores = 4.6/6). Caregiver burden was significantly negatively associated with activities of daily living and motoric difficulties as measured on the Unified Parkinson\u27s Disease Rating Scale (UPDRS). Likewise, caregiver burden was negatively associated with caregiver self-reported sleep and coping ability. Results did not demonstrate an association on the UPDRS among mentation, behavior, and mood. We found a significant negative correlation for mentation between the Folstein Mini-Mental Status Examination and caregiver burden measures; however, we did not find this association with the Dementia Rating Scale-2. Patient\u27s self-reported pain and caregiver burden were not associated
Physiotherapy for Parkinson's disease: a comparison of techniques (Review)
Background: Despite medical therapies and surgical interventions for Parkinson's disease (PD), patients develop progressive disability. The role of physiotherapy is to maximise functional ability and minimise secondary complications through movement rehabilitation within a context of education and support for the whole person. The overall aim is to optimise independence, safety and wellbeing, thereby enhancing quality of life. Trials have shown that physiotherapy has short-term benefits in PD. However, which physiotherapy intervention is most effective remains unclear. Objectives: To assess the effectiveness of one physiotherapy intervention compared with a second approach in patients with PD. Search methods: Relevant trials were identified by electronic searches of numerous literature databases (for example MEDLINE, EMBASE) and trial registers, plus handsearching of major journals, abstract books, conference proceedings and reference lists of retrieved publications. The literature search included trials published up to the end of January 2012. Selection criteria: Randomised controlled trials of one physiotherapy intervention versus another physiotherapy intervention in patients with PD. Data collection and analysis: Data were abstracted independently from each paper by two authors. Trials were classified into the following intervention comparisons: general physiotherapy, exercise, treadmill training, cueing, dance and martial arts. Main results: A total of 43 trials were identified with 1673 participants. All trials used small patient numbers (average trial size of 39 participants); the methods of randomisation and concealment of allocation were poor or not stated in most trials. Blinded assessors were used in just over half of the trials and only 10 stated that they used intention-to-treat analysis.A wide variety of validated and customised outcome measures were used to assess the effectiveness of physiotherapy interventions. The most frequently reported physiotherapy outcomes were gait speed and timed up and go, in 19 and 15 trials respectively. Only five of the 43 trials reported data on falls (12%). The motor subscales of the Unified Parkinson?s Disease Rating Scale and Parkinson?s Disease Questionnaire-39 were the most commonly reported clinician-rated disability and patient-rated quality of life outcome measures, used in 22 and 13 trials respectively. The content and delivery of the physiotherapy interventions varied widely in the trials included within this review, so no quantitative meta-analysis could be performed. Authors' conclusions: Considering the small number of participants examined, the methodological flaws in many of the studies, the possibility of publication bias, and the variety of interventions, formal comparison of the different physiotherapy techniques could not be performed. There is insufficient evidence to support or refute the effectiveness of one physiotherapy intervention over another in PD.This review shows that a wide range of physiotherapy interventions to treat PD have been tested . There is a need for more specific trials with improved treatment strategies to underpin the most appropriate choice of physiotherapy intervention and the outcomes measured
Physiotherapy versus placebo or no intervention in Parkinson's disease
Background: Despite medical therapies and surgical interventions for Parkinson's disease (PD), patients develop progressive disability. Physiotherapy aims to maximise functional ability and minimise secondary complications through movement rehabilitation within a context of education and support for the whole person. The overall aim is to optimise independence, safety, and well-being, thereby enhancing quality of life. Objectives: To assess the effectiveness of physiotherapy intervention compared with no intervention in patients with PD. Search methods: We identified relevant trials by conducting electronic searches of numerous literature databases (e.g. MEDLINE, EMBASE) and trial registers, and by handsearching major journals, abstract books, conference proceedings, and reference lists of retrieved publications. The literature search included trials published up to the end of January 2012. Selection criteria: Randomised controlled trials of physiotherapy intervention versus no physiotherapy intervention in patients with PD. Data collection and analysis: Two review authors independently extracted data from each article. We used standard meta-analysis methods to assess the effectiveness of physiotherapy intervention compared with no physiotherapy intervention. Trials were classified into the following intervention comparisons: general physiotherapy, exercise, treadmill training, cueing, dance, and martial arts. We used tests for heterogeneity to assess for differences in treatment effect across these different physiotherapy interventions. Main results: We identified 39 trials with 1827 participants. We considered the trials to be at a mixed risk of bias as the result of unreported allocation concealment and probable detection bias. Compared with no intervention, physiotherapy significantly improved the gait outcomes of speed (mean difference 0.04 m/s, 95% confidence interval (CI) 0.02 to 0.06, P = 0.0002); two- or six-minute walk test (13.37 m, 95% CI 0.55 to 26.20, P = 0.04) and Freezing of Gait questionnaire (-1.41, 95% CI -2.63 to -0.19, P = 0.02); functional mobility and balance outcomes of Timed Up & Go test (-0.63 s, 95% CI -1.05 to -0.21, P = 0.003), Functional Reach Test (2.16 cm, 95% CI 0.89 to 3.43, P = 0.0008), and Berg Balance Scale (3.71 points, 95% CI 2.30 to 5.11, P < 0.00001); and clinician-rated disability using the Unified Parkinson’s Disease Rating Scale (UPDRS) (total -6.15 points, 95% CI-8.57 to -3.73, P < 0.00001; activities of daily living: -1.36, 95% CI -2.41 to -0.30, P = 0.01; and motor: -5.01, 95% CI -6.30 to -3.72, P < 0.00001). No difference between arms was noted in falls (Falls Efficacy Scale: -1.91 points, 95% CI -4.76 to 0.94, P = 0.19) or patient-rated quality of life (PDQ-39 Summary Index: -0.38 points, 95% CI -2.58 to 1.81, P = 0.73). One study reported that adverse events were rare; no other studies reported data on this outcome. Indirect comparisons of the different physiotherapy interventions revealed no evidence that the treatment effect differed across physiotherapy interventions for any of the outcomes assessed. Authors' conclusions: Benefit for physiotherapy was found in most outcomes over the short term (i.e. < 3 months) but was significant only for speed, two- or six-minute walk test, Freezing of Gait questionnaire, Timed Up & Go, Functional Reach Test, Berg Balance Scale, and clinician-rated UPDRS. Most of the observed differences between treatments were small. However, for some outcomes (e.g. speed, Berg Balance Scale, UPDRS), the differences observed were at, or approaching, what are considered minimal clinically important changes. These benefits should be interpreted with caution because the quality of most of the included trials was not high. Variation in measurements of outcome between studies meant that our analyses include a small proportion of the participants recruited. This review illustrates that a wide range of approaches are employed by physiotherapists to treat patients with PD. However, no evidence of differences in treatment effect was noted between the different types of physiotherapy interventions being used, although this was based on indirect comparisons. A consensus menu of 'best practice' physiotherapy is needed, as are large, well-designed randomised controlled trials undertaken to demonstrate the longer-term efficacy and cost-effectiveness of 'best practice' physiotherapy in PD
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