Moussab/ORKG-training-evaluation-set huggingface dataset:
Research field: Science
Title: A probabilistic clustering algorithm in wireless sensor networks
Abstract: A wireless sensor network consists of nodes that can communicate with each other via wireless links. One way to support efficient communication between sensors is to organize the network into several groups, called clusters, with each cluster electing one node as the head of cluster. The paper describes a constant time clustering algorithm that can be applied on wireless sensor networks. This approach is an extension to the Younis and Fahmy method (1). The simulation results show that the extension can generate a small number of cluster heads in relatively few rounds, especially in sparse networks.
Extracted statement — Alg. Complexity: Constant
Research field: Science
Title: A branch-and-cut algorithm for a vendor-managed inventory-routing problem
Abstract: We consider a distribution problem in which a product has to be shipped from a supplier to several retailers over a given time horizon. Each retailer defines a maximum inventory level. The supplier monitors the inventory of each retailer and determines its replenishment policy, guaranteeing that no stockout occurs at the retailer (vendor-managed inventory policy). Every time a retailer is visited, the quantity delivered by the supplier is such that the maximum inventory level is reached (deterministic order-up-to level policy). Shipments from the supplier to the retailers are performed by a vehicle of given capacity. The problem is to determine for each discrete time instant the quantity to ship to each retailer and the vehicle route. We present a mixed-integer linear programming model and derive new additional valid inequalities used to strengthen the linear relaxation of the model. We implement a branch-and-cut algorithm to solve the model optimally. We then compare the optimal solution of the problem with the optimal solution of two problems obtained by relaxing in different ways the deterministic order-up-to level policy. Computational results are presented on a set of randomly generated problem instances.
Extracted statement — Demand: Deterministic
Research field: Science
Title: One Warehouse Multiple Retailer Systems with Vehicle Routing Costs
Abstract: We consider distribution systems with a depot and many geographically dispersed retailers each of which faces external demands occurring at constant, deterministic but retailer specific rates. All stock enters the system through the depot from where it is distributed to the retailers by a fleet of capacitated vehicles combining deliveries into efficient routes. Inventories are kept at the retailers but not at the depot. We wish to determine feasible replenishment strategies i.e., inventory rules and routing patterns minimising infinite horizon long-run average transportation and inventory costs. We restrict ourselves to a class of strategies in which a collection of regions sets of retailers is specified which cover all outlets: if an outlet belongs to several regions, a specific fraction of its sales/operations is assigned to each of these regions. Each time one of the retailers in a given region receives a delivery, this delivery is made by a vehicle who visits all other outlets in the region as well in an efficient route. We describe a class of low complexity heuristics and show under mild probabilistic assumptions that the generated solutions are asymptotically optimal within the above class of strategies. We also show that lower and upper bounds on the system-wide costs may be computed and that these bounds are asymptotically tight under the same assumptions. A numerical study exhibits the performance of these heuristics and bounds for problems of moderate size.
Extracted statement — Demand: Deterministic
Research field: Science
Title: Two-echelon distribution systems with vehicle routing costs and central inventory
Abstract: We consider distribution systems with a single depot and many retailers each of which faces external demands for a single item that occurs at a specific deterministic demand rate. All stock enters the systems through the depot where it can be stored and then picked up and distributed to the retailers by a fleet of vehicles, combining deliveries into efficient routes. We extend earlier methods for obtaining low complexity lower bounds and heuristics for systems without central stock. We show under mild probabilistic assumptions that the generated solutions and bounds come asymptotically within a few percentage points of optimality (within the considered class of strategies). A numerical study exhibits the performance of these heuristics and bounds for problems of moderate size.
Extracted statement — Demand: Deterministic
Research field: Science
Title: Integrating Routing and Inventory Decisions in One-Warehouse Multiretailer Multiproduct Distribution Systems
Abstract: We consider distribution systems with a central warehouse and many retailers that stock a number of different products. Deterministic demand occurs at the retailers for each product. The warehouse acts as a break-bulk center and does not keep any inventory. The products are delivered from the warehouse to the retailers by vehicles that combine the deliveries to several retailers into efficient vehicle routes. The objective is to determine replenishment policies that specify the delivery quantities and the vehicle routes used for the delivery, so as to minimize the long-run average inventory and transportation costs. A new heuristic that develops a stationary nested joint replenishment policy for the problem is presented in this paper. Unlike existing methods, the proposed heuristic is capable of solving problems involving distribution systems with multiple products. Results of a computational study on randomly generated single-product problems are also presented.
Extracted statement — Demand: Deterministic
Research field: Science
Title: Low energy adaptive clustering hierarchy with deterministic cluster-head selection
Abstract: This paper focuses on reducing the power consumption of wireless microsensor networks. Therefore, a communication protocol named LEACH (low-energy adaptive clustering hierarchy) is modified. We extend LEACH's stochastic cluster-head selection algorithm by a deterministic component. Depending on the network configuration an increase of network lifetime by about 30% can be accomplished. Furthermore, we present a new approach to define lifetime of microsensor networks using three new metrics FND (First Node Dies), HNA (Half of the Nodes Alive), and LND (Last Node Dies).
Extracted statement — Protocol: Deterministic
Research field: Science
Title: A dynamic clustering and energy efficient routing technique for sensor networks
Abstract: In the development of various large-scale sensor systems, a particularly challenging problem is how to dynamically organize the sensors into a wireless communication network and route sensed information from the field sensors to a remote base station. This paper presents a new energy-efficient dynamic clustering technique for large-scale sensor networks. By monitoring the received signal power from its neighboring nodes, each node estimates the number of active nodes in realtime and computes its optimal probability of becoming a cluster head, so that the amount of energy spent in both intra- and inter-cluster communications can be minimized. Based on the clustered architecture, this paper also proposes a simple multihop routing algorithm that is designed to be both energy-efficient and power-aware, so as to prolong the network lifetime. The new clustering and routing algorithms scale well and converge fast for large-scale dynamic sensor networks, as shown by our extensive simulation results.
Extracted statement — Dynamism: Dynamic
Research field: Science
Title: An Empirical Study on the Environmental Kuznets Curve for China’s Carbon Emissions: Based on Provincial Panel Data
Abstract: Abstract Based on the Environmental Kuznets Curve theory, the authors choose provincial panel data of China in 1990–2007 and adopt panel unit root and co-integration testing method to study whether there is Environmental Kuznets Curve for China’s carbon emissions. The research results show that: carbon emissions per capita of the eastern region and the central region of China fit into Environmental Kuznets Curve, but that of the western region does not. On this basis, the authors carry out scenario analysis on the occurrence time of the inflection point of carbon emissions per capita of different regions, and describe a specific time path.
Extracted statement — EKC Turnaround point(s): Eastern
Research field: Science
Title: Empty container repositioning in liner shipping1
Abstract: The efficient and effective management of empty containers is an important problem in the shipping industry. Not only does it have an economic effect, but it also has an environmental and sustainability impact, since the reduction of empty container movements will reduce fuel consumption and reduce congestion and emissions. The purposes of this paper are: to identify critical factors that affect empty container movements; to quantify the scale of empty container repositioning in major shipping routes; and to evaluate and contrast different strategies that shipping lines, and container operators, could adopt to reduce their empty container repositioning costs. The critical factors that affect empty container repositioning are identified through a review of the literature and observations of industrial practice. Taking three major routes (Trans-Pacific, Trans-Atlantic, Europe–Asia) as examples, with the assumption that trade demands could be balanced among the whole network regardless the identities of individual shipping lines, the most optimistic estimation of empty container movements can be calculated. This quantifies the scale of the empty repositioning problem. Depending on whether shipping lines are coordinating the container flows over different routes and whether they are willing to share container fleets, four strategies for empty container repositioning are presented. Mathematical programming is then applied to evaluate and contrast the performance of these strategies in three major routes. 1A preliminary version was presented in IAME Annual Conference at Dalian, China, 2–4 April 2008.
Extracted statement — Container flow: Empty
Research field: Science
Title: A Two-Stage Stochastic Network Model and Solution Methods for the Dynamic Empty Container Allocation Problem
Abstract: Containerized liner trades have been growing steadily since the globalization of world economies intensified in the early 1990s. However, these trades are typically imbalanced in terms of the numbers of inbound and outbound containers. As a result, the relocation of empty containers has become one of the major problems faced by liner operators. In this paper, we consider the dynamic empty container allocation problem where we need to reposition empty containers and to determine the number of leased con tainers needed to meet customers? demand over time. We formulate this problem as a two-stage stochastic network: in stage one, the parameters such as supplies, demands, and ship capacities for empty containers are deterministic; whereas in stage two, these parameters are random variables. We need to make decisions in stage one such that the total of the stage one cost and the expected stage two cost is minimized. By taking advantage of the network structure, we show how a stochastic quasi-gradient method and a stochastic hybrid approximation procedure can be applied to solve the problem. In addition, we propose some new variations of these methods that seem to work faster in practice. We conduct numerical tests to evaluate the value of the two-stage stochastic model over a rolling horizon environment and to investigate the behavior of the solution methods with different implementations.
Extracted statement — Container flow: Empty
Research field: Science
Title: Empty container reposition planning for intra-Asia liner shipping
Abstract: This paper addresses empty container reposition planning by plainly considering safety stock management and geographical regions. This plan could avoid drawback in practice which collects mass empty containers at a port then repositions most empty containers at a time. Empty containers occupy slots on vessel and the liner shipping company loses chance to yield freight revenue. The problem is drawn up as a two-stage problem. The upper problem is identified to estimate the empty container stock at each port and the lower problem models the empty container reposition planning with shipping service network as the Transportation Problem by Liner Problem. We looked at case studies of the Taiwan Liner Shipping Company to show the application of the proposed model. The results show the model provides optimization techniques to minimize cost of empty container reposition and to provide an evidence to adjust strategy of restructuring the shipping service network.
Extracted statement — Container flow: Empty
Research field: Science
Title: Design and analysis of a fast local clustering service for wireless sensor networks
Abstract: We present a fast local clustering service, FLOC, that partitions a multi-hop wireless network into nonoverlapping and approximately equal-sited clusters. Each cluster has a clusterhead such that all nodes within unit distance of the clusterhead belong to the cluster but no node beyond distance m from the clusterhead belongs to the cluster. By asserting m /spl ges/ 2, FLOC achieves locality: effects of cluster formation and faults/changes at any part of the network are contained within most m units. By taking unit distance to be the reliable communication radius and m to be the maximum communication radius, FLOC exploits the double-band nature of wireless radio-model and achieves clustering in constant time regardless of the network size. Through simulations and experiments with actual deployments, we analyze the tradeoffs between clustering time and the quality of clustering, and suggest suitable parameters for FLOC to achieve a fast completion time without compromising the quality of the resulting clustering.
Extracted statement — Cluster Properties Cluster size: Equal
Research field: Science
Title: Fungicidal Activity of Artemisia herba alba Asso (Asteraceae)
Abstract: The antifungal activity of Artemisia herba alba was found to be associated with two major volatile compounds isolated from the fresh leaves of the plant. Carvone and piperitone were isolated and identified by GC/MS, GC/IR, and NMR spectroscopy. Antifungal activity was measured against Penicillium citrinum (ATCC 10499) and Mucora rouxii (ATCC 24905). The antifungal activity (IC50) of the purified compounds was estimated to be 5 μ g/ml, 2 μ g/ml against Penicillium citrinum and 7 μ g/ml, 1.5 μ g/ml against Mucora rouxii carvone and piperitone, respectively.
Extracted statement — Plant material status: Fresh
Research field: Science
Title: Energy efficiency estimation based on data fusion strategy: Case study of ethylene product industry
Abstract: Data fusion is an emerging technology to fuse data from multiple data or information of the environment through measurement and detection to make a more accurate and reliable estimation or decision. In this Article, energy consumption data are collected from ethylene plants with the high temperature steam cracking process technology. An integrated framework of the energy efficiency estimation is proposed on the basis of data fusion strategy. A Hierarchical Variable Variance Fusion (HVVF) algorithm and a Fuzzy Analytic Hierarchy Process (FAHP) method are proposed to estimate energy efficiencies of ethylene equipments. For different equipment scales with the same process technology, the HVVF algorithm is used to estimate energy efficiency ranks among different equipments. For different technologies based on HVVF results, the FAHP method based on the approximate fuzzy eigenvector is used to get energy efficiency indices (EEI) of total ethylene industries. The comparisons are used to assess energy utilization...
Extracted statement — Types: Fuzzy
Research field: Science
Title: Application of fuzzy logic for state estimation of a microbial fermentation with dual inhibition and variable product kinetics. Food and Bioproducts Processing
Abstract: Fuzzy logic has been applied to a batch microbial fermentation described by a model with two adjustable parameters which associate product formation with the increasing and/or stationary phases of cell growth. The fermentation is inhibited by its product and, beyond a critical concentration, also by the substrate. To mimic an industrial condition, Gaussian noise was added and the resulting performance was simulated by fuzzy estimation systems. Simple rules with a few membership functions were able to portray bioreactor performance and the feedback interactions between cell growth and the concentrations of substrate and product. Through careful choices of the membership functions and the fuzzy logic, accuracies better than previously reported for ideal fermentations could be obtained, suggesting the suitability of fuzzy estimations for on-line applications.
Extracted statement — Types: Fuzzy
Research field: Science
Title: Stereo Processing by Semiglobal Matching and Mutual Information
Abstract: This paper describes the Semi-Global Matching (SGM) stereo method. It uses a pixelwise, Mutual Information based matching cost for compensating radiometric differences of input images. Pixelwise matching is supported by a smoothness constraint that is usually expressed as a global cost function. SGM performs a fast approximation by pathwise optimizations from all directions. The discussion also addresses occlusion detection, subpixel refinement and multi-baseline matching. Additionally, postprocessing steps for removing outliers, recovering from specific problems of structured environments and the interpolation of gaps are presented. Finally, strategies for processing almost arbitrarily large images and fusion of disparity images using orthographic projection are proposed.A comparison on standard stereo images shows that SGM is among the currently top-ranked algorithms and is best, if subpixel accuracy is considered. The complexity is linear to the number of pixels and disparity range, which results in a runtime of just 1-2s on typical test images. An in depth evaluation of the Mutual Information based matching cost demonstrates a tolerance against a wide range of radiometric transformations. Finally, examples of reconstructions from huge aerial frame and pushbroom images demonstrate that the presented ideas are working well on practical problems.
Extracted statement — Method: Global
Research field: Science
Title: Stereo matching with color-weighted correlation, hierarchical belief propagation, and occlusion handling
Abstract: In this paper, we formulate a stereo matching algorithm with careful handling of disparity, discontinuity, and occlusion. The algorithm works with a global matching stereo model based on an energy-minimization framework. The global energy contains two terms, the data term and the smoothness term. The data term is first approximated by a color-weighted correlation, then refined in occluded and low-texture areas in a repeated application of a hierarchical loopy belief propagation algorithm. The experimental results are evaluated on the Middlebury data sets, showing that our algorithm is the top performer among all the algorithms listed there.
Extracted statement — Method: Global
Research field: Science
Title: Multiresolution energy minimisation framework for stereo matching
Abstract: Global optimisation algorithms for stereo dense depth map estimation have demonstrated how to outperform other stereo algorithms such as local methods or dynamic programming. The energy minimisation framework, using Markov random fields model and solved using graph cuts or belief propagation, has especially obtained good results. The main drawback of these methods is that, although they achieve accurate reconstruction, they are not suited for real-time applications. Subsampling the input images does not reduce the complexity of the problem because it also reduces the resolution of the output in the disparity space. Nonetheless, some real-time applications such as navigation would tolerate the reduction of the depth map resolutions (width and height) while maintaining the resolution in the disparity space (number of labels). In this study a new multiresolution energy minimisation framework for real-time robotics applications is proposed where a global optimisation algorithm is applied. A reduction by a factor R of the final depth map's resolution is considered and a speed of up to 50 times has been achieved. Using high-resolution stereo pair input images guarantees that a high resolution on the disparity dimension is preserved. The proposed framework has shown how to obtain real-time performance while keeping accurate results in the Middlebury test data set.
Extracted statement — Method: Global
Research field: Science
Title: Efficient Disparity Estimation Using Hierarchical Bilateral Disparity Structure Based Graph Cut Algorithm With a Foreground Boundary Refinement Mechanism
Abstract: The disparity estimation problem is commonly solved using graph cut (GC) methods, in which the disparity assignment problem is transformed to one of minimizing global energy function. Although such an approach yields an accurate disparity map, the computational cost is relatively high. Accordingly, this paper proposes a hierarchical bilateral disparity structure (HBDS) algorithm in which the efficiency of the GC method is improved without any loss in the disparity estimation performance by dividing all the disparity levels within the stereo image hierarchically into a series of bilateral disparity structures of increasing fineness. To address the well-known foreground fattening effect, a disparity refinement process is proposed comprising a fattening foreground region detection procedure followed by a disparity recovery process. The efficiency and accuracy of the HBDS-based GC algorithm are compared with those of the conventional GC method using benchmark stereo images selected from the Middlebury dataset. In addition, the general applicability of the proposed approach is demonstrated using several real-world stereo images.
Extracted statement — Method: Global
Research field: Science
Title: Efficient GPU-Based Graph Cuts for Stereo Matching
Abstract: Although graph cuts (GC) is popularly used in many computer vision problems, slow execution time due to its high complexity hinders wide usage. Manycore solution using Graphics Processing Unit (GPU) may solve this problem. However, conventional GC implementation does not fully exploit GPU's computing power. To address this issue, a new GC algorithm which is suitable for GPU environment is presented in this paper. First, we present a novel graph construction method that accelerates the convergence speed of GC. Next, a repetitive block-based push and relabel method is used to increase the data transfer efficiency. Finally, we propose a low-overhead global relabeling algorithm to increase the GPU occupancy ratio. The experiments on Middlebury stereo dataset shows that 5.2X speedup can be achieved over the baseline implementation, with identical GPU platform and parameters.
Extracted statement — Method: Global