|An Image Processing Approach to Pre-compensation for Higher-Order Aberrations in the Eye|
Miguel Alonso Jr, Armando Barreto
Human beings rely heavily on vision for almost all of the tasks that are required in daily life. Because of this dependence on vision, humans with visual limitations, caused by genetic inheritance, disease, or age, will have difficulty in completing many of the tasks required of them. Some individuals with severe visual impairments, known as high-order aberrations, may have difficulty in interacting with computers, even when using a traditional means of visual correction (e.g., spectacles, contact lenses). This is, in part, because these correction mechanisms can only compensate for the most regular (low-order) distortions or aberrations of the image in the eye. This paper presents an image processing approach that will pre-compensate the images displayed on the computer screen, so as to counter the effect of the eye’s aberrations on the image. The characterization of the eye required to perform this customized pre-compensation is the eye’s Point Spread Function (PSF). Ophthalmic instruments generically called “Wavefront Analyzers” can now measure this description of the eye’s optical properties. The characterization provided by these instruments also includes the “higher-order aberration components” and could, therefore, lead to a more comprehensive vision correction than traditional mechanisms. This paper explains the theoretical foundation of the methods proposed and illustrates them with experiments involving the emulation of a known and constant PSF by interposing a lens in the field of view of normally sighted test subjects.
Analysis of Tube Bank Heat Transfer In Downward Directed Foam Flow
Jonas Gylys, Gintautas Miliauskas, Stasys Sinkunas, Tadas Zdankus
Apparatus with the foam flow are suitable to use in different technologies like heat exchangers, food industry, chemical and oil processing industry. Statically stable liquid foam until now is used in technologic systems rather seldom. Although a usage of this type of foam as heat transfer agent in foam equipment has a number of advantages in comparison with one phase liquid equipment: small quantity of liquid is required, heat transfer rate is rather high, mass of equipment is much smaller, energy consumption for foam delivery into heat transfer zone is lower.
The paper analyzes the peculiarities of heat transfer from distributed in staggered order and perpendicular to foam flow in channel of rectangular cross section tube bundle to the foam flow. It was estimated the dependence of mean gas velocity and volumetric void fraction of foam flow to heat transfer in downward foam flow. Significant difference of heat transfer intensity from front and back tubes of tube row in laminar foam flow was noticed. Dependence of heat transfer on flow velocity and volumetric void fraction of foam was confirmed and estimated by criterion equations.
BIG: a Grid Portal for Biomedical Data and Images
Giovanni Aloisio, Maria Cristina Barba, Euro Blasi, Massimo Cafaro, Sandro Fiore, Maria Mirto
Modern management of biomedical systems involves the use of many distributed resources, such as high performance computational resources to analyze biomedical data, mass storage systems to store them, medical instruments (microscopes, tomographs, etc.), advanced visualization and rendering tools. Grids offer the computational power, security and availability needed by such novel applications. This paper presents BIG (Biomedical Imaging Grid), a Web-based Grid portal for management of biomedical information (data and images) in a distributed environment. BIG is an interactive environment that deals with complex user’s requests, regarding the acquisition of biomedical data, the “processing” and “delivering” of biomedical images, using the power and security of Computational Grids.
Multi-Agent based Partnering Mechanism for Virtual Enterprise
Toshiya Kaihara, Susumu Fujii
Nowadays, Virtual Enterprise (VE) is a crucial paradigm of business management in agile environment. In this paper, we focus on negotiation process in VE formulation as a basic research to clarify its effective management. Each enterprise in VE is defined as agent with multi-utilities and a framework of multi-agent programming with game theoretic approach is newly proposed as negotiation algorithm amongst the agents. We develop a computer simulation model to form VE through multiple negotiations amongst several potential members in the negotiation domain, and finally clarify the formulation dynamism with the negotiation process.
Optimization of some parameters in the speech-processing module developed for the speaker independent ASR system
Josef V. Psutka, Ludek Muller
This paper deals with looking for an optimum parameterization in automatic speech recognition systems working with the speech transferred over a telephone channel. The performed experiments were supported by a large collection of training data provided from telephone calls of at least one thousand speakers. MFCC and PLP cepstral parameterizations were tested with the aim to find the optimal number of filters and coefficients. Temporal patterns describing several adjacent frames of a given frame were verified in connection with techniques ensuring feature extraction and decorelation of pattern space.
The Virtual GloveboX (VGX): a Semi-immersive Virtual Environment for Training Astronauts in Life Sciences Experiments
I. Alexander Twombly, Jeffrey D. Smith, Kevin Montgomery, Richard Boyle
The International Space Station will soon provide an unparalleled research facility for studying the near- and longer-term effects of microgravity on living systems. Using the Space Station Glovebox Facility - a compact, fully contained reach-in environment - astronauts will conduct technically challenging life sciences experiments. Virtual environment technologies are being developed at NASA Ames Research Center to help realize the scientific potential of this unique resource by facilitating the experimental hardware and protocol designs and by assisting the astronauts in training. The “Virtual GloveboX” (VGX) integrates high-fidelity graphics, force-feedback devices and real-time computer simulation engines to achieve an immersive training environment. Here, we describe the prototype VGX system, the distributed processing architecture used in the simulation environment, and modifications to the visualization pipeline required to accommodate the display configuration.
Channel Bonding in Linux Ethernet Environment using Regular Switching Hub
Chih-wen Hsueh, Hsin-hung Lin, Guo-Chiuan Huang
Bandwidth plays an important role for quality of service in most network systems. There are many technologies developed to increase host bandwidth in a LAN environment. Most of them need special hardware support, such as switching hub that supports IEEE Link Aggregation standard. In this paper, we propose a Linux solution to increase the bandwidth between hosts with multiple network adapters connected to a regular switching hub. The approach is implemented as two Linux kernel modules in a LAN environment without modification to the hardware and operating systems on host machines. Packets are dispatched to bonding network adapters for transmission. The proposed approach is backward compatible, flexible and transparent to users and only one IP address is needed for multiple bonding network adapters. Evaluation experiments in TCP and UDP transmission are shown with bandwidth gain proportionally to the number of network adapters. It is suitable for large-scale LAN systems with high bandwidth requirement, such as clustering systems.
Ideas for the Web-Based Affective Processing
Rafal Rzepka, Kenji Araki
As most of us subconsciously feel, it is a great difficulty to create a program which could imitate human
Optimal Path Planner for Mobile Robot in 2D Environment
Valeri Kroumov, Jianli Yu, Hiroshi Negishi
The problem of path planning for the case of a mobile robot moving in an environment filled with obstacles with known shapes and positions is studied. A path planner based on the genetic algorithm approach, which generates optimal in length path is proposed. The population member paths are generated by another algorithm, which uses for description of the obstacles an artificial annealing neural network and is based on potential field approach. The resulting path is piecewise linear with changing directions at the corners of the obstacles. Because of this feature, the inverse kinematics problems in controlling differential drive robots are simply solved: to drive the robot to some goal pose (x, y, theta), the robot can be spun in place until it is aimed at (x, y), then driven forward until it is at (x, y), and then spun in place until the required goal orientation
A Frequency-Based Approach to Intrusion Detection
Mian Zhou, Sheau-Dong Lang
Research on network security and intrusion detection strategies presents many challenging issues to both theoreticians and practitioners. Hackers apply an array of intrusion and exploit techniques to cause disruption of normal system operations, but on the defense, firewalls and intrusion detection systems (IDS) are typically only effective in defending known intrusion types using their signatures, and are far less than mature when faced with novel attacks. In this paper, we adapt the frequency analysis techniques such as the Discrete Fourier Transform (DFT) used in signal processing to the design of intrusion detection algorithms. We demonstrate the effectiveness of the frequency-based detection strategy by running synthetic network intrusion data in simulated networks using the OPNET software. The simulation results indicate that the proposed intrusion detection strategy is effective in detecting anomalous traffic data that exhibit patterns over time, which include several types of DOS and probe attacks. The significance of this new strategy is that it does not depend on the prior knowledge of attack signatures, thus it has the potential to be a useful supplement to existing signature-based IDS and firewalls.
A Proposal of Protocol and Policy-Based Intrusion Detection System
Tatsuya Baba, Shigeyuki Matsuda
Currently, intrusion detection systems (IDSs) are widely deployed in enterprise networks for detecting network attacks. Most existing commercial IDSs are based on misuse detection model. In misuse detection, although known attacks can be detected, unknown ones cannot be detected because attack signatures for unknown attacks cannot be generated.
In this paper, we propose a method for detecting network attacks including unknown ones against servers such as web servers, mail servers, FTP servers, and DNS servers, using protocol specifications and site access policy. Furthermore, we propose a method to predict damage from detected attacks using neural networks.
Fast algorithm for efficient simulation of quantum algorithm gates on classical computer
Sergey Panfilov, Sergey Ulyanov, Ludmila Litvintseva, Alexander Yazenin
The general approach for quantum algorithm simulation on classical computer is introduced. Efficient fast algorithm for simulation of Grover
Error Control Techniques for Efficient Multicast Streaming in UMTS Networks: Proposals andPerformance Evaluation
Michele Rossi, Frank Fitzek, Michele Zorzi
In this paper we introduce techniques for efficient multicast video streaming in UMTS networks where a video content has to be conveyed to multiple users in the same cell. Efficient multicast data delivery in UMTS is still an open issue. In particular, suitable solutions have to be found to cope with wireless channel errors, while maintaining both an acceptable channel utilization and a controlled delivery delay over the wireless link between the serving base station and the mobile terminals. Here, we first highlight that standard solutions such as unequal error protection (UEP) of the video flow are ineffective in the UMTS systems due to its inherent large feedback delay at the link layer (Radio Link Control, RLC). Subsequently, we propose a local approach to solve errors directly at the UMTS link layer while keeping a reasonably high channel efficiency and saving, as much as possible, system resources. The solution that we propose in this paper is based on the usage of the common channel to serve all the interested users in a cell. In this way, we can save resources with respect to the case where multiple dedicated channels are allocated for every user. In addition to that, we present a hybrid ARQ (HARQ) proactive protocol that, at the cost of some redundancy (added to the link layer flow), is able to consistently improve the channel efficiency with respect to the plain ARQ case, by therefore making the use of a single common channel for multicast data delivery feasible. In the last part of the paper we give some hints for future research, by envisioning the usage of the aforementioned error control protocols with suitably encoded video streams.
Micro-mechanical Simulations of Soils using Massively Parallel Supercomputers
David W. Washington, Jay N. Meegoda
In this research a computer program, Trubal version 1.51, based on the Discrete Element Method was converted to run on a Connection Machine (CM-5),a massively parallel supercomputer with 512 nodes, to expedite the computational times of simulating Geotechnical boundary value problems. The dynamic memory algorithm in Trubal program did not perform efficiently in CM-2 machine with the Single Instruction Multiple Data (SIMD) architecture. This was due to the communication overhead involving global array reductions, global array broadcast and random data movement. Therefore, a dynamic memory algorithm in Trubal program was converted to a static memory arrangement and Trubal program was successfully converted to run on CM-5 machines. The converted program was called “TRUBAL for Parallel Machines (TPM).” Simulating two physical triaxial experiments and comparing simulation results with Trubal simulations validated the TPM program. With a 512 nodes CM-5 machine TPM produced a nine-fold speedup demonstrating the inherent parallelism within algorithms based on the Discrete Element Method.
Stream Control Transmission Protocol as a Transport for SIP: a case study
Giuseppe De Marco, Maurizio Longo, Dario De Vito, Salvatore Loreto
The dominant signalling protocol both in future wireless and wired networks will be the Session Initiation Protocol (SIP), as pointed out in the 3G IP-based mobile networks specifications, entailing a fully Internet integrated network. The use of SIP in the IP Multimedia Subsytem (IMS) of Release 5 involves the development of servers capable to handle a large number of call requests. The signaling traffic associated to such requests could explode, if an intelligent congestion control were not introduced. Stream Control Transmission Protocol (SCTP) was born to support transport of SS7 signaling messages. However, many of the SCTP features are also useful for transport of SIP messages, as: congestion control mechanism, good separation among independent messages, multihoming. Indeed, adoption of SCTP as transport of SIP signaling might prove useful in some situations where usual transport protocols, like TCP and UDP, suffer performance degradation.
In this paper, we analyse the general framework wherein SIP operates and we discuss the benefits of using SCTP as a transport for SIP, toward fair sharing of network resources. This study is carried on in the context of the implementation of an high-performance SIP Proxy Server. We also present some preliminar results of an implementation of SIP over SCTP/UDP in a real LAN environment.