scholarly journals Usage of Spectral Distortion for Objective Evaluation of Personalized HRTF in the Median Plane

Author(s):  
Fabián C. Tommasini ◽  
Oscar A. Ramos ◽  
Mercedes X. Hug ◽  
Fernando Bermejo
2019 ◽  
Vol 9 (11) ◽  
pp. 2323
Author(s):  
Xuejie Liu ◽  
Hao Song ◽  
Xiaoli Zhong

Since head-related transfer functions (HRTFs) represent the interactions between sounds and physiological structures of listeners, anthropometric parameters represent a straightforward way to customize (or predict) individualized HRTFs. This paper proposes a hybrid algorithm for predicting median-plane individualized HRTFs using anthropometric parameters. The proposed hybrid algorithm consists of three parts: decomposition of HRTFs; selection of key anthropometric parameters; and establishing a prediction formula. Firstly, an independent component analysis (ICA) is applied to median-plane HRTFs from multiple subjects to obtain independent components and subject-dependent weight coefficients. Then, a factor analysis is used to select key anthropometric parameters relevant to HRTFs. Finally, a regression formula that connects ICA weight coefficients to key anthropometric parameters is established by a multiple linear regression. Further, the effectiveness of the proposed hybrid algorithm is verified by an objective evaluation via spectral distortion and a subjective localization experiment. The results show that, when compared with generic Knowles Electronics Manikin for Acoustic Research (KEMAR) HRTFs, the spectral characteristics of the predicted HRTFs are closer to those of the individualized HRTFs. Moreover, the predicted HRTFs can alleviate front–back and up–down confusion and improve the accuracy of localization for most subjects.


Electronics ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 685
Author(s):  
Jiao Jiao ◽  
Lingda Wu ◽  
Kechang Qian

In order to improve the spatial resolution of multispectral (MS) images and reduce spectral distortion, a segmentation-cooperated pansharpening method using local adaptive spectral modulation (LASM) is proposed in this paper. By using the k-means algorithm for the segmentation of MS images, different connected component groups can be obtained according to their spectral characteristics. For spectral information modulation of fusion images, the LASM coefficients are constructed based on details extracted from images and local spectral relationships among MS bands. Moreover, we introduce a cooperative theory for the pansharpening process. The local injection coefficient matrix and LASM coefficient matrix are estimated based on the connected component groups to optimize the fusion result, and the parameters of the segmentation algorithm are adjusted according to the feedback from the pansharpening result. In the experimental part, degraded and real data sets from GeoEye-1 and QuickBird satellites are used to assess the performance of our proposed method. Experimental results demonstrate the validity and effectiveness of our method. Generally, the method is superior to several classic and state-of-the-art pansharpening methods in both subjective visual effect and objective evaluation indices, achieving a balance between the injection of spatial details and maintenance of spectral information, while effectively reducing the spectral distortion of the fusion image.


Author(s):  
A. V. Crewe ◽  
M. Isaacson ◽  
D. Johnson

A double focusing magnetic spectrometer has been constructed for use with a field emission electron gun scanning microscope in order to study the electron energy loss mechanism in thin specimens. It is of the uniform field sector type with curved pole pieces. The shape of the pole pieces is determined by requiring that all particles be focused to a point at the image slit (point 1). The resultant shape gives perfect focusing in the median plane (Fig. 1) and first order focusing in the vertical plane (Fig. 2).


VASA ◽  
1999 ◽  
Vol 28 (1) ◽  
pp. 30-33 ◽  
Author(s):  
Bürger ◽  
Meyer ◽  
Tautenhahn ◽  
Halloul

Background: Objective evaluation of the management of patients with ruptured infrarenal aortic aneurysm in emergency situations has been described rarely. Patients and methods: Fifty-two consecutive patients with ruptured infrarenal aortic aneurysm (mean age, 70.3 years; range, 56–89 years; SD 7.8) were admitted between January 1993 and March 1998. Emergency protocols, final reports, and follow-up data were analyzed retrospectively. APACHE II scores at admission and fifth postoperative day were assessed. Results: The time between the appearance of first symptoms and the referral of patients to the hospital was more than 5 hours in 37 patients (71%). Thirty-eight patients (71%) had signs of shock at time of admission. Ultrasound was performed in 81% of patients as the first diagnostic procedure. The most frequent site of aortic rupture was the left retroperitoneum (87%). Intraoperatively, acute left ventricular failure occurred in four patients, and cardiac arrest in two others. The postoperative course was complicated significantly in 34 patients. The overall mortality rate was 36.5% (n = 19). In 35 patients, APACHE II score was assessed, showing a probability of death of more than 40% in five patients and lower than 30% in 17 others. No patient showing probability of death of above 75% at the fifth postoperative day survived (n = 7). Conclusions: Ruptured aortic aneurysm demands surgical intervention. Clinical outcome is also influenced by preclinical and anesthetic management. The severity of disease as well as the patient’s prognosis can be approximated using APACHE II score. Treatment results of heterogenous patient groups can be compared.


1973 ◽  
Author(s):  
Wayne Shebilske ◽  
Sheldon M. Ebenholtz
Keyword(s):  

1997 ◽  
Vol 78 (05) ◽  
pp. 1360-1365 ◽  
Author(s):  
G Freyburger ◽  
S Javorschi ◽  
S Labrouche ◽  
P Bernard

SummaryThe aim of the present study was to evaluate the relative performance of five screening methods for APC resistance caused by the factor V:Q506 mutation: the original method Coatest® APC™ Resistance Chromogenix, a modified method using the same reagents but a predilution 1+4 of the plasma in a factor V deficient plasma from Stago (Stago deficient V) or from Chromogenix (V-DEF Plasma), the Coatest® APC™ Resistance V (Chromogenix), and Accelerimat™ from bioMérieux. Normalization was done against a pool of normal plasmas for the methods from Chromogenix. The study included 350 subjects, 219 were genotyped (174 FV:R506R, 42 FV:Q506R, 3 FV:Q506Q) and most of them were assessed by more than one method. Uncertainty in predicting the FV genotype was evaluated by statistical analysis, which provided a way to quantitate the performance of the different diagnostic approaches. Performance of each test was evaluated by its sensitivity, specificity, R.O.C. curves, positive and negative likelihood ratios (LR), and the overall performance was determined by two parameters derived from the LR curves : the maximum LR value obtained at the crossover of the two curves, and the distance between the two curves for LR = 10. Coatest® APC™ Resistance V and Accelerimat™ were proven to be the methods most able to discriminate for factor V:Q506, while normalization was not shown to improve the screening performance. The original method from Chromogenix was confirmed to undergo many influences (factor XII, PAI-1, thrombin- antithrombin complexes, antithrombin III, hematocrit). Although a very good improvement was provided by the newest methods, they were shown to be influenced by protein S and/or factor V levels in the sample plasma.


2008 ◽  
Vol 225 (S 1) ◽  
Author(s):  
S Hara ◽  
MJ Sanchez ◽  
D Vucic ◽  
GU Auffarth

The article focuses on the problem of the lack of objective evaluation of space-planning arrangement of buildings as a creative approach of the architect to the performing of functional tasks by the object. It is proposed to create a methodology for assessing the functional of space-planning solutions of buildings on the basis of numerical simulation of functional processes using the theory of human flows. There is a description of the prospects of using this method, which makes it possible to increase the coefficient of compactness, materials and works saving, more efficient use of space, reduce the cost of the life cycle of the building, save human forces and time to implement the functional of the building. The necessary initial data for modeling on the example of shopping and shopping-entertainment centers are considered. There are three main tasks for algorithmization of the functional of shopping centers. The conclusion is made about necessity of development of a method for objective assessment of buildings from the point of view of ergonomics of space-planning decisions based on the study of human behavior in buildings of different purposes.


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