SIMPLE algorithm
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Many important engineering optimization problems require a strong and simple optimization algorithm to achieve the best solutions. In 2020, Rao introduced three non-parametric algorithms, known as Rao algorithms, which have garnered significant attention from researchers worldwide due to their simplicity and effectiveness in solving optimization problems. In our simulation studies, we have developed a new version of the Rao algorithm called the Fully Informed Search Algorithm (FISA), which demonstrates acceptable performance in optimizing real-world problems while maintaining the simplicity and non-parametric nature of the original algorithms. We evaluate the effectiveness of the suggested FISA approach by applying it to optimize the shifted benchmark functions, such as those provided in CEC 2005 and CEC 2014, and by using it to design mechanical system components. We compare the results of FISA to those obtained using the original RAO method. The outcomes obtained indicate the efficacy of the proposed new algorithm, FISA, in achieving optimized solutions for the aforementioned problems. The MATLAB Codes of FISA are publicly available at https://github.com/ebrahimakbary/FISA.
- Klíčová slova
- Constrained engineering optimization, Fully Informed Search Algorithm (FISA), Optimization, Rao algorithms,
- Publikační typ
- časopisecké články MeSH
Image registration tasks are often formulated in terms of minimization of a functional consisting of a data fidelity term penalizing the mismatch between the reference and the target image, and a term enforcing smoothness of shift between neighboring pairs of pixels (a min-sum problem). Most methods for deformable image registration use some form of interpolation between matching control points. The interpolation makes it impossible to account for isolated discontinuities in the deformation field that may appear, e.g., when a physical slice of a microscopy specimen is ruptured by the cutting tool. For registration of neighboring physical slices of microscopy specimens with discontinuities, Janácek proposed an L¹-distance data fidelity term and a total variation (TV) smoothness term, and used a graph-cut (GC) based iterative steepest descent algorithm for minimization. The L¹-TV functional is nonconvex; hence a steepest descent algorithm is not guaranteed to converge to the global minimum. Schlesinger presented transformation of max-sum problems to minimization of a dual quantity called problem power, which is--contrary to the original max-sum functional--convex. Based on Schlesinger's solution to max-sum problems we developed an algorithm for L¹-TV minimization by iterative multi-label steepest descent minimization of the convex dual problem. For Schlesinger's subgradient algorithm we proposed a novel step control heuristics that considerably enhances both speed and accuracy compared with standard step size strategies for subgradient methods. It is shown experimentally that our subgradient scheme achieves consistently better image registration than GC in terms of lower values both of the composite L¹-TV functional, and of its components, i.e., the L¹ distance of the images and the transformation smoothness TV, and yields visually acceptable results even in cases where the GC based algorithm fails. The new algorithm allows easy parallelization and can thus be sped up by running on multi-core graphic processing units.
- MeSH
- algoritmy * MeSH
- hlava anatomie a histologie MeSH
- mikroskopie metody MeSH
- počítačové zpracování obrazu metody MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
BACKGROUND: Accurate methods to preoperatively characterize adnexal tumors are pivotal for optimal patient management. A recent metaanalysis concluded that the International Ovarian Tumor Analysis algorithms such as the Simple Rules are the best approaches to preoperatively classify adnexal masses as benign or malignant. OBJECTIVE: We sought to develop and validate a model to predict the risk of malignancy in adnexal masses using the ultrasound features in the Simple Rules. STUDY DESIGN: This was an international cross-sectional cohort study involving 22 oncology centers, referral centers for ultrasonography, and general hospitals. We included consecutive patients with an adnexal tumor who underwent a standardized transvaginal ultrasound examination and were selected for surgery. Data on 5020 patients were recorded in 3 phases from 2002 through 2012. The 5 Simple Rules features indicative of a benign tumor (B-features) and the 5 features indicative of malignancy (M-features) are based on the presence of ascites, tumor morphology, and degree of vascularity at ultrasonography. Gold standard was the histopathologic diagnosis of the adnexal mass (pathologist blinded to ultrasound findings). Logistic regression analysis was used to estimate the risk of malignancy based on the 10 ultrasound features and type of center. The diagnostic performance was evaluated by area under the receiver operating characteristic curve, sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), positive predictive value (PPV), negative predictive value (NPV), and calibration curves. RESULTS: Data on 4848 patients were analyzed. The malignancy rate was 43% (1402/3263) in oncology centers and 17% (263/1585) in other centers. The area under the receiver operating characteristic curve on validation data was very similar in oncology centers (0.917; 95% confidence interval, 0.901-0.931) and other centers (0.916; 95% confidence interval, 0.873-0.945). Risk estimates showed good calibration. In all, 23% of patients in the validation data set had a very low estimated risk (<1%) and 48% had a high estimated risk (≥30%). For the 1% risk cutoff, sensitivity was 99.7%, specificity 33.7%, LR+ 1.5, LR- 0.010, PPV 44.8%, and NPV 98.9%. For the 30% risk cutoff, sensitivity was 89.0%, specificity 84.7%, LR+ 5.8, LR- 0.13, PPV 75.4%, and NPV 93.9%. CONCLUSION: Quantification of the risk of malignancy based on the Simple Rules has good diagnostic performance both in oncology centers and other centers. A simple classification based on these risk estimates may form the basis of a clinical management system. Patients with a high risk may benefit from surgery by a gynecological oncologist, while patients with a lower risk may be managed locally.
- Klíčová slova
- International Ovarian Tumor Analysis, Simple Rules, adnexa, color Doppler, diagnosis, diagnostic algorithm, logistic regression analysis, ovarian cancer, ovarian neoplasms, preoperative evaluation, risk assessment, ultrasonography,
- MeSH
- hodnocení rizik MeSH
- kohortové studie MeSH
- lidé MeSH
- logistické modely MeSH
- nemoci děložních adnex diagnostické zobrazování MeSH
- nemocnice MeSH
- onkologická péče - zařízení MeSH
- prediktivní hodnota testů MeSH
- průřezové studie MeSH
- ROC křivka MeSH
- senzitivita a specificita MeSH
- ultrasonografie dopplerovská barevná MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- multicentrická studie MeSH
- práce podpořená grantem MeSH
- validační studie MeSH
We present a new algorithm to analyse information content in images acquired using automated fluorescence microscopy. The algorithm belongs to the group of autofocusing methods, but differs from its predecessors in that it can handle thick specimens and operate also in confocal mode. It measures the information content in images using a 'content function', which is essentially the same concept as a focus function. Unlike previously presented algorithms, this algorithm tries to find all significant axial positions in cases where the content function applied to real data is not unimodal, which is often the case. This requirement precludes using algorithms that rely on unimodality. Moreover, choosing a content function requires careful consideration, because some functions suppress local maxima. First, we test 19 content functions and evaluate their ability to show local maxima clearly. The results show that only six content functions succeed. To save time, the acquisition procedure needs to vary the step size adaptively, because a wide range of possible axial positions has to be passed so as not to miss a local maximum. The algorithm therefore has to assess the steepness of the content function online so that it can decide to use a bigger or smaller step size to acquire the next image. Therefore, the algorithm needs to know about typical behaviour of content functions. We show that for normalized variance, one of the most promising content functions, this knowledge can be obtained after normalizing with respect to the theoretical maximum of this function, and using hierarchical clustering. The resulting algorithm is more reliable and efficient than a simple procedure with constant steps.
- MeSH
- algoritmy * MeSH
- buněčné jádro ultrastruktura MeSH
- fibroblasty ultrastruktura MeSH
- fluorescenční mikroskopie metody MeSH
- lidé MeSH
- on-line systémy MeSH
- počítačové zpracování obrazu metody MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Delay represents a significant phenomenon in the dynamics of many human-related systems-including biological ones. It has i.a. a decisive impact on system stability, and the study of this influence is often mathematically demanding. This paper presents a computationally simple numerical gridding algorithm for the determination of stability margin delay values in multiple-delay linear systems. The characteristic quasi-polynomial-the roots of which decide about stability-is subjected to iterative discretization by means of pre-warped bilinear transformation. Then, a linear and a quadratic interpolation are applied to obtain the associated characteristic polynomial with integer powers. The roots of the associated characteristic polynomial are closely related to the estimation of roots of the original characteristic quasi-polynomial which agrees with the system's eigenvalues. Since the stability border is crossed by the leading one, the switching root locus is enhanced using the Regula Falsi interpolation method. Our methodology is implemented on-and verified by-a numerical bio-cybernetic example of the stabilization of a human-being's movement on a controlled swaying bow. The advantage of the proposed novel algorithm lies in the possibility of the rapid computation of polynomial zeros by means of standard programs for technical computing; in the low level of mathematical knowledge required; and, in the sufficiently high precision of the roots loci estimation. The relationship to the direct search QuasiPolynomial (mapping) Rootfinder algorithm and computational complexity are discussed as well. This algorithm is also applicable for systems with non-commensurate delays.
- MeSH
- algoritmy * MeSH
- lidé MeSH
- pohyb fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: The oncologic safety of minimally invasive simple hysterectomy in low-risk cervical cancer has not been explored by an adequately powered clinical trial. PRIMARY OBJECTIVE: This study aims to evaluate whether minimally invasive simple hysterectomy affects disease-free survival in low-risk early-stage cervical cancer. STUDY HYPOTHESIS: Minimally invasive simple hysterectomy represents an oncologically safe approach in selected patients with low-risk cervical cancer. TRIAL DESIGN: This is a single-arm trial with stopping rules. All patients must undergo cervical conization. Patients with clear conization margins or absence of residual macroscopic disease at imaging after conization (re-conization is mandatory if these criteria are not met) are submitted to minimally invasive (laparoscopy or robot-assisted laparoscopy) simple hysterectomy with sentinel lymph node biopsy algorithm. Adjuvant therapy is given in case of tumor-involved surgical margins, and/or metastatic lymph nodes, and/or substantial lymphovascular space invasion with depth of stromal infiltration >2/3 (or tumor-free distance ≤3 mm). MAJOR INCLUSION/EXCLUSION CRITERIA: The major inclusion criteria are: squamous cell carcinoma, human papillomavirus-related adenocarcinoma, adenosquamous carcinoma of the uterine cervix; International Federation of Gynecology and Obstetrics 2018 stage IA2-IB1 (≤2 cm) with depth of infiltration ≤10 mm on conization specimen; International Federation of Gynecology and Obstetrics 2018 stage IA2-IB1 (≤2 cm) with depth of infiltration ≤50% at pre-conization magnetic resonance imaging scan or "expert" ultrasound scan. Women are not eligible if they have evidence of metastatic disease, contra-indications to surgery and/or lymph node assessment, or fertility sparing desire. PRIMARY ENDPOINT: The primary end point is 3-year disease-free survival of patients who undergo minimally invasive simple hysterectomy. SAMPLE SIZE: A sample size of 974 patients will give a power of 80% at a significance level of 2.5% (1-sided) to reject the null hypothesis of a 3-year recurrence rate of 2.4%, assuming a 3-year recurrence rate of 1.2%. A maximum of 14 recurrences at 3 years should be observed to reject the null hypothesis. A stopping rule based on the number of recurrences observed at different timepoints will be implemented to avoid a higher recurrence rate with the study procedure. The trial will also be stopped if no recurrences are observed in the first 400 patients followed up for 2 years. ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS: The enrolment will last 60 months. After the surgery, the follow-up time will be ≥3 years. TRIAL REGISTRATION: The trial is registered at ClinicalTrials.gov (NCT06416748) and as ENGOT/MITO trial (ENGOT-cx23).
- Klíčová slova
- Cervical Cancer, LASH trial, Laparoscopy, Low Risk, Minimally Invasive, Robotic Surgery, Simple Hysterectomy,
- MeSH
- dospělí MeSH
- hysterektomie * metody MeSH
- konizace děložního čípku MeSH
- laparoskopie metody MeSH
- lidé středního věku MeSH
- lidé MeSH
- miniinvazivní chirurgické výkony metody MeSH
- nádory děložního čípku * chirurgie patologie MeSH
- roboticky asistované výkony metody MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- klinické zkoušky MeSH
A minute, yet practical, modification of a well-known spectrograph based on a set of wedged narrow band filters is presented. It makes possible two-dimensional-imaging spectral measurements with a potential subpixel precision of a few micrometers. The simple spectroscopic device can evaluate dispersion of quantities which can be transformed into an image, e.g., into a spatial beam distribution. The spectrograph was used to measure angular dispersion of both a laser oscillator producing femtosecond pulses and a simple dispersive optical system, an optical wedge.
- MeSH
- algoritmy MeSH
- časové faktory MeSH
- design vybavení MeSH
- fantomy radiodiagnostické MeSH
- fluorescenční mikroskopie přístrojové vybavení metody MeSH
- interferometrie metody MeSH
- lasery MeSH
- optika a fotonika MeSH
- oscilometrie MeSH
- počítačové zpracování obrazu metody MeSH
- počítačové zpracování signálu přístrojové vybavení MeSH
- spektrofotometrie metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
OBJECTIVE: The early, simple and reliable detection of pulmonary arterial hypertension (PAH) in SSc (DETECT) study described a new algorithm for early detection of PAH in patients with SSc. The aim of this retrospective, single-centre, cross-sectional study was to apply a modified DETECT calculator in patients with SSc in the East Bohemian region, Czech Republic, to assess the risk of PAH and to compare these results with PAH screening based on the European Society of Cardiology/European Respiratory Society (ESC/ERS) 2009 guidelines. METHODS: Sixty patients were recruited with a diagnosis of SSc (according to ACR criteria), aged 27-78 years. A modified DETECT algorithm using the modified parameter of (1.4 × right ventricle diameter)(2) in place of right atrium area was applied to all patients. Right heart catheterization (RHC) was performed in all patients with an estimated (by echocardiography) increased systolic pulmonary artery pressure ≥50 mm Hg in accordance with the ESC/ERS guidelines; however, RHC was not performed in patients solely recommended for RHC using the modified DETECT algorithm. RESULTS: Using the modified DETECT calculator, 24/58 (41.4%) patients were recommended for RHC, compared with 14/58 (24.1%) when applying the ESC/ERS 2009 guidelines. PAH was diagnosed in 7/58 (12.1%) patients. During follow-up, PAH was diagnosed in six patients. Of these, four were modified DETECT score-positive for 2 years and all for 1 year before PAH diagnosis. CONCLUSION: The modified DETECT algorithm detects all patients with PAH diagnosed according to ECS/ERS 2009 guidelines and RHC. Data of the 2-year follow-up indicate a possible positive predictive role for the modified DETECT calculator.
- Klíčová slova
- cardiovascular, clinical trials and methods, epidemiology, respiratory, scleroderma and related disorders,
- MeSH
- algoritmy * MeSH
- časná diagnóza * MeSH
- centra terciární péče * MeSH
- dospělí MeSH
- echokardiografie MeSH
- incidence MeSH
- lidé středního věku MeSH
- lidé MeSH
- následné studie MeSH
- plicní hypertenze diagnóza epidemiologie etiologie MeSH
- průřezové studie MeSH
- retrospektivní studie MeSH
- senioři MeSH
- srdeční katetrizace MeSH
- systémová sklerodermie komplikace diagnóza MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika epidemiologie MeSH
The new extended Monte Carlo (MC) simulation method for photon transport in S(T)EM back scattered electron (BSE) scintillation detection systems of various shapes is presented in this paper. The method makes use of the random generation of photon emission from a scintillator luminescent centre and describes the trajectory of photons and the efficiency of their transport toward the photocathode of the photomultiplier tube. The paper explains a new algorithm for determining the position of interaction of the photon with the surface of the single crystal scintillator or of the light guide with nearly arbitrary shapes. Some examples of the utilization of the simulation method are also included, and conclusions for very simple edge-guided signal (EGS) scintillation detection systems made. The computer optimized design of the BSE scintillation detector for the S 4000 Hitachi SEM was chosen to demonstrate the capability of this MC simulation method.
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
UNLABELLED: We report on the further development of FAst MEtabolizer (FAME; J. Chem. Inf. MODEL: 2013, 53, 2896-2907), a collection of random forest models for the prediction of sites of metabolism (SoMs) of xenobiotics. A broad set of descriptors was explored, from simple 2D descriptors such as those used in FAME, to quantum chemical descriptors employed in some of the most accurate models for SoM prediction currently available. In line with the original FAME approach, our objective was to keep things simple and to come up with accurate and robust models that are based on a small number of 2D descriptors. We found that circular descriptions of atoms and their environments with such descriptors in combination with an extremely randomized trees algorithm can yield models that perform equally well compared to more complex approaches. Thorough evaluation experiments on an independent test set showed that the best of these models obtained a Matthews correlation coefficient, area under the receiver operating characteristic curve, and Top-2 accuracy of 0.57, 0.91 and 94.1%, respectively. Models for the prediction of isoform-specific regioselectivity of CYP 3A4, 2D6, and 2C9 were also developed and showed competitive performance. The best models have been integrated into a newly developed software package (FAME 2), which is available free of charge from the authors.
- MeSH
- software MeSH
- stereoizomerie MeSH
- strojové učení * MeSH
- substrátová specifita MeSH
- systém (enzymů) cytochromů P-450 metabolismus MeSH
- výpočetní biologie metody MeSH
- xenobiotika chemie metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- systém (enzymů) cytochromů P-450 MeSH
- xenobiotika MeSH