Analysis, Visualization, and Transformation of Audio Signals Using Dictionary-based Methods

date-added: 2014-01-07 09:15:58 +0000 date-modified: 2014-01-07 09:15:58 +0000date-added: 2014-01-07 09:15:58 +0000 date-modified: 2014-01-07 09:15:58 +000

The major geoeffective solar eruptions of 2012 March 7: comprehensive Sun-to-Earth analysis

During the interval 2012 March 7-11 the geospace experienced a barrage of intense space weather phenomena including the second largest geomagnetic storm of solar cycle 24 so far. Significant ultra-low-frequency wave enhancements and relativistic-electron dropouts in the radiation belts, as well as strong energetic-electron injection events in the magnetosphere were observed. These phenomena were ultimately associated with two ultra-fast (>2000 kms-1) coronal mass ejections (CMEs), linked to two X-class flares launched on early 2012 March 7. Given that both powerful events originated from solar active region NOAA 11429 and their onsets were separated by less than an hour, the analysis of the two events and the determination of solar causes and geospace effects are rather challenging. Using satellite data from a flotilla of solar, heliospheric and magnetospheric missions a synergistic Sun-to-Earth study of diverse observational solar, interplanetary and magnetospheric data sets was performed. It was found that only the second CME was Earth-directed. Using a novel method, we estimated its near-Sun magnetic field at 13R⊙ to be in the range [0.01, 0.16] G. Steep radial fall-offs of the near-Sun CME magnetic field are required to match the magnetic fields of the corresponding interplanetary CME (ICME) at 1 AU. Perturbed upstream solar-wind conditions, as resulting from the shock associated with the Earth-directed CME, offer a decent description of its kinematics. The magnetospheric compression caused by the arrival at 1 AU of the shock associated with the ICME was a key factor for radiation-belt dynamics.Publisher PDFPeer reviewe

Composing first species counterpoint with a variable neighbourhood search algorithm

In this article, a variable neighbourhood search (VNS) algorithm is developed that can generate musical fragments consisting of a melody for the cantus firmus and the first species counterpoint. The objective function of the algorithm is based on a quantification of existing rules for counterpoint. The VNS algorithm developed in this article is a local search algorithm that starts from a randomly generated melody and improves it by changing one or two notes at a time. A thorough parametric analysis of the VNS reveals the significance of the algorithm's parameters on the quality of the composed fragment, as well as their optimal settings. A comparison of the VNS algorithm with a developed genetic algorithm shows that the VNS is more efficient. The VNS algorithm has been implemented in a user-friendly software environment for composition, called Optimuse. Optimuse allows a user to specify a number of characteristics such as length, key and mode. Based on this information, Optimuse 'composes' both cantus firmus and first species counterpoint. Alternatively, the user may specify a cantus firmus, and let Optimuse compose the accompanying first species counterpoint. © 2012 Taylor & Francis

Three dimensional analysis of cervical spine motion using a computer assisted magnetic tracking device

Background and Purpose. The purpose of this study is to investigate the reliability and reproducibility of a magnetic tracking technique for the assessment of overall cervical spine motion (principal and coupled movements). Subjects and Methods. Ten asymptomatic male volunteers with a mean age of 29.3 (range, 20-37 years) years were included in this study. Flexion, extension, left and right lateral bending and left and right axial rotation were measured using a magnetic tracking device mounted onto a custom head piece. A detailed statistical analysis was made to determine the inter-, and intra-observer reliability. Results. High intra- and inter-observer reliability was found in flexion, extension, axial rotation, and lateral bending indicating that the testing routine is applicable for different examiners. Conclusions and Discussion. The magnetic tracking device method described in our study is a reliable, reproducible method for three dimensional motion analysis of the cervical spine. The method is well suited for the clinical assessment of various degenerative and traumatic disorders. It may also supplement different therapeutic procedures and rehabilitation

Visualizing Sound, Hearing Diagrams: On the Creative Process of Syrmos by Iannis Xenakis

A salient feature of Iannis Xenakis’ compositional practices was the use of several concepts and techniques borrowed from architectural design and from scientific fields. He sometimes drew complete graphic scores preluding the transcription of his fair copy of conventional musical notation. I discuss the diagrammatical features of Xenakis’ graphic score for Syrmos: although disparate representations depend on shared image schemata and cross-modal correspondences, their respective compositional logics are dissimilar

The role of MRI in the evaluation of hip joint disease in clinical subtypes of juvenile idiopathic arthritis

The purpose of this study was to evaluate the role of MRI in the assessment of hip joint involvement in clinical subtypes of juvenile idiopathic arthritis (JIA). 28 patients (mean age 12.5 years) with JIA (oligoarthritis 8, polyarthritis 13, systemic arthritis 7) were examined with T(2) weighted turbo spin echo and T(1) weighted spin echo (plain and contrast enhanced) sequences. The severity of joint involvement was evaluated using an MR grading score: grade 1=no contrast enhancement; grade 2=focal synovial contrast enhancement; grade 3=diffuse synovial contrast enhancement; grade 4=grade 3+diffuse synovial thickening; grade 5=grade 4+villonodular synovial thickening; and grade 6=grade 5+cartilage and subchondral bone erosions. MRI was abnormal in 57.1% of cases (25% of oligoarthritis, 53.8% of polyarthritis and 100% of systemic arthritis). Clinical examination was positive in 32.1% of cases and was associated with higher MR grades (mean 4.6, SD 1.34) compared with a negative clinical examination, which was associated with lower MR grades (mean 1.78, SD 1.13) (p<0.001). Patients with active disease (mean grade 3.9, SD 2) had higher MR grades than those with inactive disease (mean grade 2.1, SD 1.4) (p<0.01). The MR grades were different in the three clinical subtypes: oligoarticular (mean 1.5, SD 1.06); polyarticular (mean 2.38, SD 1.55); and systemic (mean 4.85, SD 1.21) (F:12.3, p<0.001), with a significant difference between systemic arthritis and oligoarthritis, and between systemic arthritis and polyarthritis (p<0.001). MRI of the hip might be considered for inclusion in the study protocol of patients with JIA since it reveals joint involvement at early stages and provides a detailed evaluation of the extent of joint disease.Br J Radio

Misdiagnosed bilateral C5-C6 dislocation causing cervical spine instability: a case report

INTRODUCTION: The diagnosis of cervical spine injuries remains a significant problem in many blunt trauma patients. Correct and early diagnosis of these injuries is imperative as delayed or missed diagnoses result in increased morbidity and mortality. CASE PRESENTATION: A 57-year-old Caucasian woman presented with a misdiagnosed bilateral C5-C6 dislocation one month after a fall and head injury, without clearance of the cervical spine in her previous visits to two physicians and having already started physiotherapy sessions, despite the presence of pain in the clinical examination. Dislocation was treated with open reduction and spinal fusion with posterior instrumentation 4 weeks post-trauma. CONCLUSIONS: Every physician should be highly suspicious of cervical spine injury in blunt trauma patients with positive clinical examination and include radiologic studies in his screening modality. Physiotherapy sessions should under no circumstances be started in the presence of underlying spine injury.Cases

Testing a Spectral Model of Tonal Affinity with Microtonal Melodies and Inharmonic Spectra

Tonal affinity is the perceived goodness of fit of successive tones. It is important because a preference for certain intervals over others would likely influence preferences for, and prevalences of, “higher-order” musical structures such as scales and chord progressions. We hypothesize that two psychoacoustic (spectral) factors—harmonicity and spectral pitch similarity—have an impact on affinity. The harmonicity of a single tone is the extent to which its partials (frequency components) correspond to those of a harmonic complex tone (whose partials are a multiple of a single fundamental frequency). The spectral pitch similarity of two tones is the extent to which they have partials with corresponding, or close, frequencies. To ascertain the unique effect sizes of harmonicity and spectral pitch similarity, we constructed a computational model to numerically quantify them. The model was tested against data obtained from 44 participants who ranked the overall affinity of tones in melodies played in a variety of tunings (some microtonal) with a variety of spectra (some inharmonic). The data indicate the two factors have similar, but independent, effect sizes: in combination, they explain a sizeable portion of the variance in the data (the model-data squared correlation is r2 = .64). Neither harmonicity nor spectral pitch similarity require prior knowledge of musical structure, so they provide a potentially universal bottom-up explanation for tonal affinity. We show how the model—as optimized to these data—can explain scale structures commonly found in music, both historical and contemporary, and we discuss its implications for experimental microtonal and spectral music