Search results for "Benchmark"
showing 10 items of 310 documents
Benchmarking Wilms’ tumor in multisequence MRI data: why does current clinical practice fail? Which popular segmentation algorithms perform well?
2019
Wilms' tumor is one of the most frequent malignant solid tumors in childhood. Accurate segmentation of tumor tissue is a key step during therapy and treatment planning. Since it is difficult to obtain a comprehensive set of tumor data of children, there is no benchmark so far allowing evaluation of the quality of human or computer-based segmentations. The contributions in our paper are threefold: (i) we present the first heterogeneous Wilms' tumor benchmark data set. It contains multisequence MRI data sets before and after chemotherapy, along with ground truth annotation, approximated based on the consensus of five human experts. (ii) We analyze human expert annotations and interrater varia…
The Hierarchical Mixed Rural Postman Problem: Polyhedral analysis and a branch-and-cut algorithm
2017
[EN] The Hierarchical Mixed Rural Postman Problem is defined on a mixed graph where arcs and edges that require a service are divided into clusters' that have to be serviced in a hierarchical order. The problem generalizes the Mixed Rural Postman Problem and thus is NP-hard. In this paper, we provide a polyhedral analysis of the problem and propose a branch-and-cut algorithm for its solution based on the introduced classes of valid inequalities. Extensive computational experiments are reported on benchmark instances. The exact approach allows to find the optimal solutions in less than 1 hour for instances with up to 999 vertices, 2678 links, and five clusters.
Separating compound figures in journal articles to allow for subfigure classification
2013
Journal images represent an important part of the knowledge stored in the medical literature. Figure classification has received much attention as the information of the image types can be used in a variety of contexts to focus image search and filter out unwanted information or ”noise”, for example non–clinical images. A major problem in figure classification is the fact that many figures in the biomedical literature are compound figures and do often contain more than a single figure type. Some journals do separate compound figures into several parts but many do not, thus requiring currently manual separation. In this work, a technique of compound figure separation is proposed and implemen…
SHREC 2020: Retrieval of digital surfaces with similar geometric reliefs
2020
Abstract This paper presents the methods that have participated in the SHREC’20 contest on retrieval of surface patches with similar geometric reliefs and the analysis of their performance over the benchmark created for this challenge. The goal of the context is to verify the possibility of retrieving 3D models only based on the reliefs that are present on their surface and to compare methods that are suitable for this task. This problem is related to many real world applications, such as the classification of cultural heritage goods or the analysis of different materials. To address this challenge, it is necessary to characterize the local ”geometric pattern” information, possibly forgetti…
The impact of privatization approaches on the productivity growth of the water industry: A case study of Chile
2015
Abstract The water industry faces the challenge of implementing privatization reforms. This process mainly adopts the following two approaches: the privatization of public water and sewerage services (WSS) and the privatization of water companies’ ownership. This paper investigates the impact of both privatization approaches on changes in productivity in the water industry. In doing so, the Luenberger productivity indicator (LPI) was computed for a sample of Chilean water and sewerage companies (WaSCs) for the period 1997–2013. Unlike the most commonly applied index (Malmquist productivity index), the LPI simultaneously takes into account output expansion and input contraction. The results …
Formulations for an inventory routing problem
2014
In this paper, we present and compare formulations for the inventory routing problem (IRP) where the demand of customers has to be served, over a discrete time horizon, by capacitated vehicles starting and ending their routes at a depot. The objective of the IRP is the minimization of the sum of inventory and transportation costs. The formulations include known and new mathematical programming formulations. Valid inequalities are also presented. The formulations are tested on a large set of benchmark instances. One of the most significant conclusions is that the formulations that use vehicle-indexed variables are superior to the more compact, aggregate formulations.
Barriers in organizing the Romanian firms in responsibility centers
2017
In the current turbulent business environment, the big and medium enterprises must organize their activity in order to face new challenges. One of the organizational forms that can stimulate the performances of the firms is the one in responsibility centers. This paper addresses the issue of the responsibility centers starting from the possibility of using benchmarking before and after the implementation of this organizational form. After highlighting the advantages of the responsibility centers, we presented a study made in Romanian big and medium organizations, regarding the barriers in the design and implementation of this organizational form. The main causes that determine Romanian mana…
Physical environment as a source for innovation: investigating the attributes of innovative space
2013
Purpose – The purpose of this paper is to investigate how physical spaces intersect with innovation and innovativeness, and what the most relevant attributes of physical space are for innovation. Design/methodology/approach – The paper reflects the changing nature of innovation, from technological advancements to services and meaning changes, and argues that the development of innovative spaces similarly embodies a diverse set of values such as collaboration, openness, and sustainability. Using a literature review, interviews, and benchmarking data, the paper examines the relationship between physical environment and innovation. Findings – The findings from both the literature review and t…
FCA-based knowledge representation and local generalized linear models to address relevance and diversity in diverse social images
2019
Abstract In social image retrieval, the main goal is to offer a relevant but also diverse result set of images to the user. To address relevance and diversity at the same time, we propose a multi-modal procedure. This approach deals with the diversification problem using a two-step procedure based on the application of Formal Concept Analysis (FCA) to organize the text content of the images, followed by a Hierarchical Agglomerative Clustering (HAC) step to find the topics addressed by the images. FCA detects the latent concepts covered by the images in the result set, organizing them according to these concepts. In the second step, clustering is carried out to group together the ones with a…
Youth Unemployment in Romania: Post-crisis Challenges
2014
Abstract This article reviews the dynamics of the Romanian youth labour market between 2007 and 2013. Using total unemployment rate as benchmarking we describe the dynamics of youth unemployment during these years. We argue that the short time effects of the crisis on youth unemployment are just one side of the problem. The long term effects related to education and migration trends are the main challenges that labour market policies should address in the near future.