Search results for "surrogate"
showing 10 items of 145 documents
Treed Gaussian Process Regression for Solving Offline Data-Driven Continuous Multiobjective Optimization Problems
2023
Abstract For offline data-driven multiobjective optimization problems (MOPs), no new data is available during the optimization process. Approximation models (or surrogates) are first built using the provided offline data and an optimizer, e.g. a multiobjective evolutionary algorithm, can then be utilized to find Pareto optimal solutions to the problem with surrogates as objective functions. In contrast to online data-driven MOPs, these surrogates cannot be updated with new data and, hence, the approximation accuracy cannot be improved by considering new data during the optimization process. Gaussian process regression (GPR) models are widely used as surrogates because of their ability to pr…
An Interactive Framework for Offline Data-Driven Multiobjective Optimization
2020
We propose a framework for solving offline data-driven multiobjective optimization problems in an interactive manner. No new data becomes available when solving offline problems. We fit surrogate models to the data to enable optimization, which introduces uncertainty. The framework incorporates preference information from a decision maker in two aspects to direct the solution process. Firstly, the decision maker can guide the optimization by providing preferences for objectives. Secondly, the framework features a novel technique for the decision maker to also express preferences related to maximum acceptable uncertainty in the solutions as preferred ranges of uncertainty. In this way, the d…
Engineering in-plane mechanics of electrospun polyurethane scaffolds for cardiovascular tissue applications
2021
Effective cardiovascular tissue surrogates require high control of scaffold structural and mechanical features to match native tissue properties, which are dependent on tissue-specific mechanics, function heterogenicity, and morphology. Bridging scaffold processing variables with native tissue properties is recognized as a priority for advancing biomechanical performance of biomedical materials and, when translated to the clinical practice, their efficacy. Accordingly, this study selected electrospinning on a rotating cylindrical target as an apparatus of broad application and mapped the relationship between key processing variables and scaffold mechanics and structure. This information was…
Genistein in the Metabolic Syndrome: Results of a Randomized Clinical Trial
2013
Context: This study was performed to evaluate the effects of genistein on metabolic and cardiovascular risk factors in Caucasian postmenopausal subjects with metabolic syndrome (MetS). Objective: Our objective was to assess the effects of genistein on surrogate endpoints associated with diabetes and cardiovascular disease. Design and Setting: This was a randomized, double-blind, placebo-controlled trial at 3 university medical centers in Italy. Patients: Patients included 120 postmenopausal women with MetS according to modified Third Report of the National Cholesterol Education Program (NCEP), Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (Adult Tre…
Comparative evaluation of molecular methods for the quantitative measure of torquetenovirus (TTV) viremia, the new surrogate marker of immune compete…
2019
Background Torquetenovirus (TTV) viremia is emerging as a promising tool to assess functional immune competence, to predict posttransplant immune-related complications, and eventually to customize immunosuppression. Methods In this study, 327 blood samples were tested using two real-time PCR (rtPCR) assays both targeted to the untranslated region of the TTV genome. The first assay was an in-house rtPCR developed by our group, the second one was the recently marketed TTV R-GENE assay. Results In the validation study, the TTV R-GENE showed good performances in precision and reproducibility, and sensitivity as low as 12 TTV DNA copies/mL, like previously reported for the in-house rtPCR. The Bl…
How does the journal impact factor affect the CV of PhD students?
2014
In his editorial “Dear DORA”, Howy Jacobs commented on the recent San Francisco Declaration of Research Assessment (DORA) to address the misuse of the journal impact factor (IF) and discussed alternatives. DORA stipulates that the IF must not be used as a surrogate measure of the quality of individual research articles, or to assess an individual scientist's contributions in hiring, promotion and funding decisions. DORA and many other commentators, such as Howy Jacobs, therefore advocate the use of additional, alternative metrics and other measures to make a more fair and realistic judgment about the quality of a scientist's or …
Duration of previous treatment as a prognostic factor in metastatic colorectal cancer treated with trifluridine/tipiracil
2018
We herein describe the findings from the trifluridine/tipiracil (TAS-102) Compassionate Use program in Latvia, set up prior to marketing authorization for the management of pretreated patients with metastatic colorectal cancer (mCRC). The efficacy and safety of TAS-102 in patients with refractory mCRC were evaluated in the phase III trial RECOURSE. A previous report confirmed neutropenia and duration of previous treatment for mCRC as prognostic factors in TAS-102 users. The aim of the present study was to analyze possible prognostic factors, such as neutropenia, in TAS-102 responders. A retrospective analysis of 14 patients who received TAS-102 chemotherapy in two institutions in Latvia (Cl…
Continuous ambulatory peritoneal dialysis as a therapeutic alternative in patients with advanced congestive heart failure.
2012
Aims Continuous ambulatory peritoneal dialysis (CAPD) has been proposed as an additional therapeutic resource for patients with advanced congestive heart failure (CHF). The objective of this study was to determine the therapeutic role of CAPD, in terms of surrogate endpoints, in the management of patients with advanced CHF and renal dysfunction. A total of 57 candidates with New York Heart Association (NYHA) class III/IV CHF, renal dysfunction (glomerular filtration rate , 60 mL/min/1.73 m 2 ), persistent fluid congestion despite loop diuretic treatment, and at least two previous hospitalizations for acute heart failure (AHF) were invited to be included in the CAPD programme; however, 25 pa…
Agent assisted interactive algorithm for computationally demanding multiobjective optimization problems
2015
Abstract We generalize the applicability of interactive methods for solving computationally demanding, that is, time-consuming, multiobjective optimization problems. For this purpose we propose a new agent assisted interactive algorithm. It employs a computationally inexpensive surrogate problem and four different agents that intelligently update the surrogate based on the preferences specified by a decision maker. In this way, we decrease the waiting times imposed on the decision maker during the interactive solution process and at the same time decrease the amount of preference information expected from the decision maker. The agent assisted algorithm is not specific to any interactive me…
Assessment of treatment response in hepatocellular carcinoma: a review of the literature
2013
Hepatocellular carcinoma (HCC) has a high incidence all over the world. Even if the primary end point of treatment of HCC is survival, radiological response could be a surrogate end point of survival, and could have a key role in clinical management. Since 1950 several radiological response criteria have been applied; however, it was not until 2000 that specific criteria for HCC were introduced by the European Association for the Study of the Liver (EASL), and these were then standardized in 2010 with the development of the modified Response Evaluation Criteria for Solid Tumors (mRECIST) for HCC. The purpose of this brief review is to compare data in literature regarding the application an…