ppxscal/embedding_network huggingface dataset:
Crop/weed discrimination in perspective agronomic images
Authors: Ch. Gée, J. Bossu, G. Jones, F. Truchetet
Venue: Computers and Electronics in Agriculture (2008)

This paper presents a general method for weed infestation rate estimation for perspective wide-view images dedicated to real-time precision spraying. A colour camera was positioned above crop fields in order to get a wide angle view of crop rows in perspective. Before to test it on in-field images, the algorithm has been optimized on simulated images and its robustness face to different weed infestation rates is analysed. The proposed method can be divided into the two following steps. Firstly a crop row detection is performed from the identification of the vanishing point taking the opportunity of the perspective geometry of the scene. Hence, an algorithm based on a double Hough transform (DHT) is applied. Afterwards, the discrimination between crop and weeds is done by a region-based segmentation method using a blob colouring analysis. The DHT was proved to be applicable to different perspective angles and different spatial frequencies of crop seedlings. Based on the geometrical properties of the scene, the results showed that the DHT has been proved to be a reliable crop row detection method but the crop/weed discrimination algorithm needs to be optimized. The discussion focuses on the efficiency and the limits of this spatial method.
Mining geographic knowledge using location aware topic model
Authors: Chong Wang, Jinggang Wang, Xing Xie, Wei-Ying Ma
Venue: Proceedings of the 4th ACM workshop on Geographical information retrieval (2007)

Most online activities are associated with geographical locations. For example, people write personal blogs about interesting places they have ever been to; read news about important local events; and search the web to find delicious restaurants. Mining geographical knowledge from these online activities can greatly benefit lots of web applications. In this paper, we propose a Location Aware Topic Model (LATM), a probabilistic graphical model, to explicitly model the relationships between locations and words. Experiments on several data sets, including news and blogs, showed satisfactory results.
Multi-band SAR Images Fusion Using the EM Algorithm in Contourlet Domain
Authors: Xiao-lei Wei, Yong-an Zheng, Zhan-zhong Cui, Quan-li Wang
Venue: Proceedings of the Fourth International Conference on Fuzzy Systems and Knowledge Discovery - Volume 01 (2007)

Aimed at the fusion of multi-band Synthetic Aperture Radar(SAR) images, a new fused method using estimation theory in the contourlet transform domain is presented. Contourlet transform is a new "true" two-dimension presentation for images which provided a flexible multiresolution, anisotropy and directional expansion. The coefficients of contourlets can be accurately modeled by Gaussian mixture model. This approach is based on an image formation model which the contourlet coefficients of multi-band SAR images are described as the true scene corrupted by Gaussian mixture distortion. A set of iterative equations are developed using the Expectation Maximization(EM) algorithm to estimate the model parameters and produce the fused images. The efficiency of this approach is verified by fusing the Ku, X bands and L, Ku bands SAR images. Also, some statistical factors are employed for evaluating the objective quality of the fused result.
Distributed Multimedia Digital Libraries on Peer-to-Peer Networks
Authors: Edoardo Ardizzone, Luca Gatani, Marco La Cascia, Giuseppe Lo Re, Marco Ortolani
Venue: Proceedings of the 14th International Conference of Image Analysis and Processing - Workshops (2007)

This paper presents an original approach to image shar- ing in large, distributed digital libraries, in which a user is able to interactively search interesting resources by means of content-based image retrieval techniques. The approach described here addresses the issues arising when the con- tent is managed through a Peer-to-Peer architecture. In this case, the retrieval facilities are likely to be limited to queries based on unique identifiers or small sets of keywords, which may be quite inadequate, so we propose a novel algorithm for routing user queries that exploits compact representa- tions of multimedia resources shared by each peer in order to dynamically adapt the network topology to peer interests on the basis of query interactions among users.
A graph-theoretical approach for pattern discovery in epidemiological research
Authors: Richard A. Mushlin, Aaron Kershenbaum, Stephen T. Gallagher, Timothy R. Rebbeck
Venue: IBM Systems Journal (2007)

In this paper we describe a graph-theoretical approach for pattern discovery that is especially useful in epidemiological research when applied to case-control studies involving categorical features such as genotypes and exposures. Whereas existing approaches are limited to exploring relationships among two or three factors, or deal with thousands of genes but are unable to isolate interactions among individual genes, we focus on interactions among tens of genes. We present a pattern discovery algorithm that finds associations among multiple factors, such as genetic and environmental factors, and groups of individuals (cases and controls) in a clinical survey. To validate our approach and to demonstrate its effectiveness, we applied it to a selection of synthetic data sets that were devised to emulate the situations encountered in epidemiological studies involving common diseases with suspected associations involving multiple factors that could include inherited genotypes, somatic genotypes, demographic characteristics, or exposures. The results of this experiment show that it is possible to identify the effects of multiple factors in moderate-size surveys (involving hundreds of individuals) even when the number of factors is greater than three.
Black-Scholes versus Artificial Neural Networks in Pricing Call Warrants: the Case of China Market
Authors: Wei Zhou, Meiying Yang, Liyan Han
Venue: Proceedings of the Third International Conference on Natural Computation - Volume 01 (2007)

The back-propagation neural network is used to pricing call warrants, and the input variables of network model are investigated. The market call warrants prices quoted on Shanghai Stock Exchange and Shenzhen Stock Exchange are used to train and simulate the network model. The results show that the performances of the proposed network model produce better call warrant prices than Black-Scholes, and better depict the price characteristics of China's call warrants. The pricing error of Black-Scholes is detailed analyzed, and the market particularities of China's call warrants with different contract terms and price characteristics are also discussed.
IP-Based Fast Handoff Scheme for Heterogeneous Wireless Networks
Authors: Christian Makaya, Samuel Pierre
Venue: Proceedings of the Third IEEE International Conference on Wireless and Mobile Computing, Networking and Communications (2007)

networks (NGWN), mobility management is one of the most crucial. In fact, provision of seamless roaming and services con- tinuity is required for multimedia applications and particularly in presence of heterogeneous wireless environments. Although several IP-based mobility protocols have been proposed in the literature, they are not able to guarantee seamless roaming, especially for real-time applications. This paper proposes an efficient handoff protocol, called enhanced Handoff Protocol for Integrated Networks (eHPIN). This protocol carries out localized mobility management, fast or anticipated handoff, and access network discovery in order to alleviates services disruption during roaming in heterogeneous IPv6-based wireless environ- ments. Simulation results show benefits of eHPIN in term of signaling traffic overhead cost, end-to-end throughput, handoff latency and packet loss compared to existing IPv6-based mobility management protocols. Index Terms-- IP mobility, heterogeneous wireless networks, vertical handoff, seamless roaming, services continuity.
Probabilistic Model Checking Modulo Theories
Authors: Bjorn Wachter, Lijun Zhang, Holger Hermanns
Venue: Proceedings of the Fourth International Conference on Quantitative Evaluation of Systems (2007)

Probabilistic models are widely used to analyze embedded, networked, and more recently biological systems. Existing numerical analysis techniques are limited to finitestate models and suffer from the state explosion problem. As a consequence, the user often has to manually abstract the intended model to get a tractable one. To this end, we propose the predicate abstraction model checker PASS which automates this process. We leverage recent advances in automatic theorem proving to compute tractable finite-state models. Experiments show the feasibility of our approach. To the best of our knowledge, this is the first time that properties of probabilistic infinite-state models have been verified at this level of automation.
A Novel Wireless Channel Model with Multiply Feed-forward Neural Network
Authors: Lin Lv
Venue: Proceedings of the Third International Conference on Natural Computation - Volume 01 (2007)

According to the mechanism of Feed-forward Neural Networks (FNN), this paper describes a wireless communication channels model based on multilayer FNN. Utilizing the excellent learning characteristics of Neural Networks (NN), give a modeling method with improved back propagation (BP) algorithm and the simulation results, analyze the existed problems and the settling means as well. Simultaneously, simulation results show that the FNN model can track the time-varying characteristic of nonstationary wireless channels very well. When applied to practical wireless communication channels, several unique merits of this method are also demonstrated.
Light emission from semiconductor triode
Authors: S. Mil'shtein, J. Palma, C. Liessner, C. Gil
Venue: Microelectronics Journal (2007)

Light emission in a novel HEMT-like structure was observed under conditions of strong reverse bias on the Schottky gate with a positive bias on the drain. Two distinct regions of light emission are present in the device with emission of red shaded light at the drain side of the gate and off-white color emission at the drain. These two distinct colors are clearly visible with the use of a microscope. The bias levels under which light emission occurs approach those necessary for catastrophic device breakdown. In the continuation of the study, spectroscopy of the emitted light is planned.
A k-Round Elimination Contention Scheme for WLANs
Authors: Bosheng Zhou, Alan Marshall, Tsung-Han Lee
Venue: IEEE Transactions on Mobile Computing (2007)

The contention resolution scheme is a key component in carrier sense based wireless MAC protocols. It has a major impact on MAC’s performance metrics such as throughput, delay, and jitter. The IEEE 802.11 DCF adopts a simple contention resolution scheme, namely Binary Exponential Backoff (BEB) scheme. The BEB achieves a reasonable performance for transmitting best-effort packets in small-size wireless networks. However, as the network size increases, it suffers from inefficiency because of the medium contention, which leads to reduced performance. The main reason is that the BEB mechanism incurs an everincreasing collision rate as the number of contending nodes increases. We devise a novel contention resolution scheme, a k-round elimination contention (k-EC) scheme. The k-EC scheme exhibits high efficiency and robustness during the collision resolution. More importantly, it is insensitive to the number of contending nodes. This feature makes it feasible for use in networks of different sizes. Simulation results show that the k-EC scheme offers a powerful remedy to medium contention resolution. It significantly outperforms the IEEE 802.11 DCF scheme in all the MAC’s performance metrics, and also exhibits better fairness.
The Research of Network Planning Risk Element Transmission Theory Based on Genetic Algorithm
Authors: Cunbin Li, Kecheng Wang
Venue: Proceedings of the Third International Conference on Natural Computation - Volume 04 (2007)

Risk management project is an important aspect of general project risk element transmission theory. Traditional network planning technology encountered great obstacles in project risk management issues, and often unable to accurately forecast the risk, resulting great loss of costs. To address the cost-time optimization problem considering the risk elements, this paper established a network planning risk element model, which divides risk elements into discrete model and continuous model to be discussed separately. In the discrete model costs and risk element matrix is introduced to get the corresponding programming model; In Continuous model the idea of machine learning model is used to minimum the desired risk. Based on this model, by using genetic algorithm's efficient and rapid global search capability, this paper improves the genetic algorithm developed by Feng and others, increases the risk elements and eventually gets the cost-time curve considering risk elements. This effectively solves the network planning cost optimization problem..
Design and Implementation of a Manageable IPv6 Wireless Multicast Platform
Authors: HUANG Zhi-teng, LI Zhi-huai, ZHOU Xiao-wei
Venue: Proceedings of the 2007 IFIP International Conference on Network and Parallel Computing Workshops (2007)

Almost all current multicast platforms and test beds are developed to serve the research goals, which mainly focus on multicast routing protocols and/or specific multicast applications. Therefore, there's a gap between these platforms and test beds and the requirement of reality. These platforms and test beds lack of management support of multicast IP assignment, multicast session and other demands such as authorization and authentication of connected users. In this paper, we propose the prototype of a Manageable IPv6 Wireless Multicast Platform (MWMP6). Combined with multicast session directory and other modules, MWMP6 provides management functionalities for multicast address, multicast session and multicast content. Besides, security issues like user authentication are also taken in count. MWMP6 can support various typical wireless multicast applications under wireless network environment. The experiment result shows that MWMP6 is capable to serve wireless multicast in Wireless LAN.
B-picture coding in AVS video compression standard
Authors: Xiangyang Ji, Debin Zhao, Feng Wu, Yan Lu, Wen Gao
Venue: Image Communication (2008)

This paper first gives a brief overview of the Chinese audio-video coding standard (AVS) especially on prediction modes of motion compensation for B-picture. Furthermore, two techniques adopted by AVS about how to improve motion compensation for B-picture coding are discussed in detail. The first one is the proposed symmetrical mode that replaces the conventional bi-directional mode, in which only one motion vector is coded and another is derived from the coded one with the assumption of approximate constant-speed motion. It can achieve a better trade-off between prediction accuracy and the bits for coding motion information. The second one is the improved temporal direct mode. It not only solves the problem in AVS on how to correctly derive reference index under the constraint of two reference buffers for both P- and B-pictures but also improves the accuracy of derived motion vectors in temporal direct mode with division-free operations. In experimental results, the proposed symmetrical mode and the improved temporal direct mode were integrated into the H.264/MPEG-4 AVC reference software to exhibit their performances. Furthermore, the B-picture coding performance in AVS is also evaluated using different GOP coding structures.
Adaptive processing of historical spatial range queries in peer-to-peer sensor networks
Authors: Alexandru Coman, Joerg Sander, Mario A. Nascimento
Venue: Distributed and Parallel Databases (2007)

We investigate the problem of processing historical queries on a sensor network. Since data is considered to have been already collected at the sensor nodes, the main issue is exploring the spatial component of the query in order to minimize its cost represented by the energy consumption. We assume queries can be issued at any network node, i.e., there is no central base station and all nodes have only local knowledge of the network. On the one hand, a globally optimum query processing plan is desirable but its construction is not possible due to the lack of global knowledge of the network. On the other hand, while a simple network flooding is feasible, it is not a practical choice from a cost perspective. To address this problem we propose a two-phase query processing strategy, where in the first phase a path from the query originator to the query region is found and in the second phase the query is processed within the query region itself. This strategy is supported by analytical models that are used to dynamically select the best processing strategy depending on the query specifics. Our extensive analytical and experimental results show that our analytical models are accurate and that the two-phase strategy is better suited for small to medium sized queries, being up to 10 times more cost effective than a typical network flooding. In addition, the dynamic selection of a query processing technique proved itself capable of always delivering at least as good performance as the most energy efficient strategy for all query sizes.
Multihoming route control among a group of multihomed stub networks
Authors: Yong Liu, A.L. Narasimha Reddy
Venue: Computer Communications (2007)

In recent years, commercial ''multihoming route control'' devices are used by multihomed stub networks to optimize the routing of their Internet traffic. Previous studies have shown that ''multihoming route control'' can improve the Internet communication performance of the multihomed stub networks significantly. In this work, we study ''multihoming route control'' among a group of multihomed stub networks that may belong to an organization and exchange large amount of data regularly. We show that greedy ''multihoming routing control'' schemes could lead to oscillations. We propose a user-optimal routing based ''multihoming routing control'' scheme that improves routing performance without causing oscillations. The proposed scheme is simpler to implement than optimal routing based approaches. We show through simulations that the proposed scheme achieves performance close to optimal routing and works well in various network conditions.
Initialization strategies and diversity in evolutionary timetabling
Authors: Edmund K. Burke, James P. Newall, Rupert F. Weare
Venue: Evolutionary Computation (1998)

This document seeks to provide a scientific basis by which different initialization algorithms for evolutionary timetabling may be compared. Seeding the initial population may be used to improve initial quality and provide a better starting point for the evolutionary algorithm. This must be tempered against the consideration that if the seeding algorithm produces very similar solutions, then the loss of genetic diversity may well lead to a worse final solution. Diversity, we hope, provides a good indication of how good the final solution will be, although only by running the evolutionary algorithm will the exact result be found. We will investigate the effects of heuristic seeding by taking quality and diversity measures of populations generated by heuristic initialization methods on both random and real-life data, as well as assessing the long-term performance of an evolutionary algorithm (found to work well on the timetabling problem) when using heuristic initialization. This will show how the use of heuristic initialization strategies can substantially improve the performance of evolutionary algorithms for the timetabling problem.
Mixture of Spherical Distributions for Single-View Relighting
Authors: Kenji Hara, Ko Nishino, Katsushi Ikeuchi
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2008)

We present a method for simultaneously estimating the illumination of a scene and the reflectance property of an object from single view images – a single image or a small number of images taken from the same viewpoint. We assume that the illumination consists of multiple point light sources and the shape of the object is known. First, we represent the illumination on the surface of a unit sphere as a finite mixture of von Mises-Fisher distributions based on a novel spherical specular reflection model that well approximates the Torrance-Sparrow reflection model. Next, we estimate the parameters of this mixture model including the number of its component distributions and the standard deviation of them, which correspond to the number of light sources and the surface roughness, respectively. Finally, using these results as the initial estimates, we iteratively refine the estimates based on the original Torrance-Sparrow reflection model. The final estimates can be used to relight single-view images such as altering the intensities and directions of the individual light sources. The proposed method provides a unified framework based on directional statistics for simultaneously estimating the intensities and directions of an unknown number of light sources as well as the specular reflection parameter of the object in the scene.
Theories of Software Reliability: How Good Are They and How Can They Be Improved?
Authors: B. Littlewood
Venue: IEEE Transactions on Software Engineering (1980)

An examination of the assumptions used in early bug-counting models of software reliability shows them to be deficient. Suggestions are made to improve modeling assumptions and examples are given of mathematical implementations. Model verification via real-life data is discussed and minimum requirements are presented. An example shows how these requirements may be satisfied in practice. It is suggested that current theories are only the first step along what threatens to be a long road.
Post silicon power/performance optimization in the presence of process variations using individual well-adaptive body biasing
Authors: Justin Gregg, Tom W. Chen
Venue: IEEE Transactions on Very Large Scale Integration (VLSI) Systems (2007)

The economics of continued scaling of silicon process technologies beyond the 90-nm node will face significant challenges due to variability. The increasing relative magnitude of within die process variations will cause power-frequency distributions to widen, thus, reducing manufacturing yields. Mitigating the effects of these process variations can be done by using the proposed individual well-adaptive body biasing (IWABB) scheme of locally generated body biases. IWABB allows for highly localized circuit optimizations with very little overhead in silicon area and routing resources. We present two algorithms to find near-optimal configurations of these biases which can be applied as postsilicon tuning. The proposed IWABB scheme can improve an initial yield from 12% to 73%.