1,657 research outputs found
Advances of Robust Subspace Face Recognition
Face recognition has been widely applied in fast video surveillance and security systems and smart home services in our daily lives. Over past years, subspace projection methods, such as principal component analysis (PCA), linear discriminant analysis (LDA), are the well-known algorithms for face recognition. Recently, linear regression classification (LRC) is one of the most popular approaches through subspace projection optimizations. However, there are still many problems unsolved in severe conditions with different environments and various applications. In this chapter, the practical problems including partial occlusion, illumination variation, different expression, pose variation, and low resolution are addressed and solved by several improved subspace projection methods including robust linear regression classification (RLRC), ridge regression (RR), improved principal component regression (IPCR), unitary regression classification (URC), linear discriminant regression classification (LDRC), generalized linear regression classification (GLRC) and trimmed linear regression (TLR). Experimental results show that these methods can perform well and possess high robustness against problems of partial occlusion, illumination variation, different expression, pose variation and low resolution
A retrospective study of magnetic resonance-guided focused ultrasound ablation for uterine myoma in Taiwan
AbstractObjectiveTo report our experiences with 40 patients who were treated with magnetic resonance-guided focused ultrasound surgery (MRgFUS) for uterine fibroids and their 6-month follow-up status.Materials and MethodsA total of 40 patients with uterine fibroids underwent MRgFUS from January 2009 to November 2011. The Uterine Fibroid Symptoms and Quality of Life Questionnaire was used to determine the patients' Symptom Severity Scores (SSS) prior to and 6 months after treatment. The nonperfused volume (NPV) values and NPV ratio were obtained immediately at the end of the treatment and at 6 months follow-up.ResultsNo procedure-related complications were noted throughout the 6-month follow-up period among the 40 patients who underwent MRgFUS for uterine fibroids. The mean reduction in SSS in our patients after 6 months was 43.7%, and the mean reduction of fibroid volume was 31.7%. In addition, the mean reduction of NPV and mean NPV ratio was 52.7% and 33.3%, respectively.ConclusionThe results obtained from this study demonstrated that MRgFUS can be safely and effectively used to ablate uterine fibroids to produce a significant decrease in mean fibroid volume and improve SSS for up to 6 months after treatment
Intraclass reliability for assessing how well Taiwan constrained hospital-provided medical services using statistical process control chart techniques
BACKGROUND: Few studies discuss the indicators used to assess the effect on cost containment in healthcare across hospitals in a single-payer national healthcare system with constrained medical resources. We present the intraclass correlation coefficient (ICC) to assess how well Taiwan constrained hospital-provided medical services in such a system. METHODS: A custom Excel-VBA routine to record the distances of standard deviations (SDs) from the central line (the mean over the previous 12 months) of a control chart was used to construct and scale annual medical expenditures sequentially from 2000 to 2009 for 421 hospitals in Taiwan to generate the ICC. The ICC was then used to evaluate Taiwan’s year-based convergent power to remain unchanged in hospital-provided constrained medical services. A bubble chart of SDs for a specific month was generated to present the effects of using control charts in a national healthcare system. RESULTS: ICCs were generated for Taiwan’s year-based convergent power to constrain its medical services from 2000 to 2009. All hospital groups showed a gradually well-controlled supply of services that decreased from 0.772 to 0.415. The bubble chart identified outlier hospitals that required investigation of possible excessive reimbursements in a specific time period. CONCLUSION: We recommend using the ICC to annually assess a nation’s year-based convergent power to constrain medical services across hospitals. Using sequential control charts to regularly monitor hospital reimbursements is required to achieve financial control in a single-payer nationwide healthcare system
Electronic band structures of Ge1−xSnx semiconductors: A first-principles density functional theory study
[[abstract]]We conduct first-principles total-energy density functional calculations to study the band structures in Ge 1− x Sn x infrared semiconductor alloys. The norm-conserving optimized pseudopotentials of Ge and Sn have been constructed for electronic structure calculations. The composition-bandgap relationships in Ge 1−x Sn x lattices are evaluated by a detailed comparison of structural models and their electronic band structures. The critical Sn composition related to the transition from indirect- to direct-gap in Ge 1−x Sn x alloys is estimated to be as low as x∼ 0.016 determined from the parametric fit. Our results show that the crossover Sn concentration occurs at a lower critical Sn concentration than the values predicted from the absorption measurements. However, early results indicate that the reliability of the critical Sn concentration from such measurements is hard to establish, since the indirect gap absorption is much weaker than the direct gap absorption. We find that the direct band gap decreases exponentially with the Sn composition over the range 0 0.375, in very good agreement with the theoretical observed behavior [D. W. Jenkins and J. D. Dow, Phys. Rev. B 36, 7994, 1987]. For homonuclear and heteronuclear complexes of Ge 1−x Sn x alloys, the indirect band gap at L-pointis is found to decrease homonuclear Ge-Ge bonds or increase homonuclear Sn-Sn bonds as a result of the reduced L valley. All findings agree with previously reported experimental and theoretical results. The analysis suggests that the top of valence band exhibits the localization of bond charge and the bottom of the conduction band is composed of the Ge 4s4p and/or Sn 5s5p atomic orbits.[[booktype]]紙本[[booktype]]電子
Activation of β-Adrenoceptors by Dobutamine May Induce a Higher Expression of Peroxisome Proliferator-Activated Receptors δ (PPARδ) in Neonatal Rat Cardiomyocytes
Recent evidence showed the role of peroxisome proliferator-activated receptors (PPARs) in cardiac function. Cardiac contraction induced by various agents is critical in restoring the activity of peroxisome proliferator-activated receptors δ (PPARδ) in cardiac myopathy. Because dobutamine is an agent widely used to treat heart failure in emergency setting, this study is aimed to investigate the change of PPARδ in response to dobutamine. Neonatal rat cardiomyocytes were used to examine the effects of dobutamine on PPARδ expression levels and cardiac troponin I (cTnI) phosphorylation via Western blotting analysis. We show that treatment with dobutamine increased PPARδ expression and cTnI phosphorylation in a time- and dose-dependent manner in neonatal rat cardiomyocytes. These increases were blocked by the antagonist of β1-adrenoceptors. Also, the action of dobutamine was related to the increase of calcium ions and diminished by chelating intracellular calcium. Additionally, dobutamine-induced action was reduced by the inhibition of downstream messengers involved in this calcium-related pathway. Moreover, deletion of PPARδ using siRNA generated the reduction of cTnI phosphorylation in cardiomyocytes treated with dobutamine. Thus, we concluded that PPARδ is increased by dobutamine in cardiac cells
Temperature Swing Adsorption Process for CO2 Capture Using Polyaniline Solid Sorbent
AbstractTo capture carbon dioxide from power plant flue gas which consists of 15% CO2 and 85% N2, with a temperature swing adsorption (TSA) by using polyaniline solid sorbent as the adsorbent, is explored experimentally and theoretically. First, single component adsorption equilibrium data of carbon dioxide on polyaniline solid sorbent is obtained by using Micro-Balance Thermo D-200. Then isotherm curves and the parameters are obtained by numerical method. The adsorption is expressed by the Langmuir-Freundlich isotherm. After accomplishment of isotherm curves, the breakthrough curve experiment is investigated with single adsorption column. The experiments test the change in adsorbed gas concentration at the outlet by adsorbed gas, CO2, and non-adsorbed gas, helium. Finally, this study accentuates the TSA experiments on CO2 purity and recovery by operation variable discussion which includes feed pressure, adsorption temperature and desorption temperature to find optimal operation condition. The results of optimal operation condition are CO2 purity of 47.65% with a 92.46% recovery
Time-Frequency Analysis of Superorbital Modulation of X-ray Binary SMC X-1 by Hilbert-Huang Transform
The high-mass X-ray binary (HMXB) SMC X-1 exhibits a superorbital modulation
with a dramatically varying period ranging between ~40 d and ~60 d. This
research studies the time-frequency properties of the superorbital modulation
of SMC X-1 based on the observations made by the All-Sky Monitor (ASM) onboard
the Rossi X-ray Timing Explorer (RXTE).We analyzed the entire ASM database
collected since 1996. The Hilbert-Huang Transform (HHT), developed for
non-stationary and nonlinear time series analysis, was adopted to derive the
instantaneous superorbital frequency. The resultant Hilbert spectrum is
consistent with the dynamic power spectrum while it shows more detailed
information in both the time and frequency domains. The RXTE observations
manifest that the superorbital modulation period was mostly betweenn ~50 d and
~65 d, whenas it changed to ~45 d around MJD 50,800 and MJD 54,000. Our
analysis further indicates that the instantaneous frequency changed in a time
scale of hundreds of days between ~MJD 51,500 and ~MJD 53,500. Based on the
instantaneous phase defined by HHT, we folded the ASM light curve to derive a
superorbital profile, from which an asymmetric feature and a low state with
barely any X-ray emissions (lasting for ~0.3 cycles) were observed. We also
calculated the correlation between the mean period and the amplitude of the
superorbital modulation. The result is similar to the recently discovered
relationship between the superorbital cycle length and the mean X-ray flux for
Her X-1.Comment: 26 pages, 9 figures, accepted for publication in The Astrophysical
Journa
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