Abstract: Competing risks survival data that comprises of more
than one type of event has been used in many applications, and one
of these is in clinical study (e.g. in breast cancer study). The
decision tree method can be extended to competing risks survival
data by modifying the split function so as to accommodate two or
more risks which might be dependent on each other. Recently,
researchers have constructed some decision trees for recurrent
survival time data using frailty and marginal modelling. We further
extended the method for the case of competing risks. In this paper,
we developed the decision tree method for competing risks survival
time data based on proportional hazards for subdistribution of
competing risks. In particular, we grow a tree by using deviance
statistic. The application of breast cancer data is presented. Finally,
to investigate the performance of the proposed method, simulation
studies on identification of true group of observations were executed.
Abstract: This paper describes a paradigmatic approach to develop architecture of secure systems by describing the requirements from four different points of view: that of the owner, the administrator, the user, and the network. Deriving requirements and developing architecture implies the joint elicitation and describing the problem and the structure of the solution. The view points proposed in this paper are those we consider as requirements towards their contributions as major parties in the design, implementation, usage and maintenance of secure systems. The dramatic growth of the technology of Internet and the applications deployed in World Wide Web have lead to the situation where the security has become a very important concern in the development of secure systems. Many security approaches are currently being used in organizations. In spite of the widespread use of many different security solutions, the security remains a problem. It is argued that the approach that is described in this paper for the development of secure architecture is practical by all means. The models representing these multiple points of view are termed the requirements model (views of owner and administrator) and the operations model (views of user and network). In this paper, this multiple view paradigm is explained by first describing the specific requirements and or characteristics of secure systems (particularly in the domain of networks) and the secure architecture / system development methodology.
Abstract: The river flow forecasting represents a crucial point to employ for improving a management policy addressed to the right use of water resources as well as for conjugating prevention and defense actions against environmental degradation. The difficulties occurring during the field activities encourage the development and implementation of operative computation and measuring methods addressed to time reduction for data acquisition and processing maintaining a good level of accuracy. Therefore, the aim of the present work is to test a new entropy based expeditive methodology for the evaluation of the rating curves on three gauged sections with different geometric and morphological characteristics. The methodology requires the choice of only three verticals along the measure section and the sampling of only the maximum velocity. The results underline how in most conditions the rating curves drawn can replace those built with classic methodologies, simplifying thus the procedures of data monitoring and calculation.
Abstract: In this study, a fuzzy similarity approach for Arabic web pages classification is presented. The approach uses a fuzzy term-category relation by manipulating membership degree for the training data and the degree value for a test web page. Six measures are used and compared in this study. These measures include: Einstein, Algebraic, Hamacher, MinMax, Special case fuzzy and Bounded Difference approaches. These measures are applied and compared using 50 different Arabic web-pages. Einstein measure was gave best performance among the other measures. An analysis of these measures and concluding remarks are drawn in this study.
Abstract: In recent years, “Bottom-up Planning Approach" has been widely accepted and expanded from planning theorists. Citizen participation becomes more important in decision-making in informal settlements. Many of previous projects and strategies due to ignorance of citizen participation, have been failed facing with informal settlements and in some cases lead physical expansion of these neighbourhoods. According to recent experiences, the new participatory approach was in somehow successful. This paper focuses on local experiences in Iran. A considerable amount of people live in informal settlements in Iran. With the previous methods, the government could not solve the problems of these settlements. It is time to examine new methods such as empowerment of the local citizens and involve them to solve the current physical, social, and economic problems. The paper aims to address the previous and new strategies facing with informal settlements, the conditions under which citizens could be involved in planning process, limits and potentials of this process, the main actors and issues and finally motivations that are able to promote citizen participation. Documentary studies, observation, interview and questionnaire have been used to achieve the above mentioned objectives. Nearly 80 percent of responder in Saadi Community are ready to participate in regularising their neighbourhoods, if pre-conditions of citizen involvement are being provided. These pre-conditions include kind of problem and its severity, the importance of issue, existence of a short-term solution, etc. Moreover, confirmation of dweller-s ownership can promote the citizen engagement in participatory projects.
Abstract: We consider here the subsonic impinging jet
representing the flow field of a vertical take-off aircraft or the initial
stage of rocket launching. Implicit Large-Eddy Simulation (ILES) is
used to calculate the time-dependent flow field and the radiate sound
pressure associated with jet impinging. With proper boundary
treatments and high-order numerical scheme, the near field sound
pressure is successfully obtained. Results are presented for both a
rectangular as well a circular jet.
Abstract: Threedimensional numerical simulations are conducted on a full scale CANDU Moderator and Transient variations of the temperature and velocity distributions inside the tank are determined. The results show that the flow and temperature distributions inside the moderator tank are three dimensional and no symmetry plane can be identified.Competition between the upward moving buoyancy driven flows and the downward moving momentum driven flows, results in the formation of circulation zones. The moderator tank operates in the buoyancy driven mode and any small disturbances in the flow or temperature makes the system unstable and asymmetric. Different types of temperature fluctuations are noted inside the tank: (i) large amplitude are at the boundaries between the hot and cold (ii) low amplitude are in the core of the tank (iii) high frequency fluctuations are in the regions with high velocities and (iv) low frequency fluctuations are in the regions with lower velocities.
Abstract: A semi-analytic boundary discretization method, the Method of Auxiliary Sources (MAS) is used to analyze Optical Antennas consisting of metallic parts. In addition to standard dipoletype antennas, consisting of two pieces of metal, a new structure consisting of a single metal piece with a tiny groove in the center is analyzed. It is demonstrated that difficult numerical problems are caused because optical antennas exhibit strong material dispersion, loss, and plasmon-polariton effects that require a very accurate numerical simulation. This structure takes advantage of the Channel Plasmon-Polariton (CPP) effect and exhibits a strong enhancement of the electric field in the groove. Also primitive 3D antenna model with spherical nano particles is analyzed.
Abstract: This paper investigates the problem of absolute stability and robust stability of a class of Lur-e systems with neutral type and time-varying delays. By using Lyapunov direct method and linear matrix inequality technique, new delay-dependent stability criteria are obtained and formulated in terms of linear matrix inequalities (LMIs) which are easy to check the stability of the considered systems. To obtain less conservative stability conditions, an operator is defined to construct the Lyapunov functional. Also, the free weighting matrices approach combining a matrix inequality technique is used to reduce the entailed conservativeness. Numerical examples are given to indicate significant improvements over some existing results.
Abstract: We obtain appropriate sharp estimates for rough oscillatory integrals. Our results represent significant improvements as well as natural extensions of what was known previously.
Abstract: In the forming of ceramic materials the plasticity
concept is commonly used. This term is related to a particular
mechanical behavior when clay is mixed with water. A plastic
ceramic material shows a permanent strain without rupture
when a compressive load produces a shear stress that exceeds
the material-s yield strength. For a plastic ceramic body it
observes a measurable elastic behavior before the yield
strength and when the applied load is removed. In this work, a
mathematical model was developed from applied concepts of
the plasticity theory by using the stress/strain diagram under
compression.
Abstract: The microbial production of ethanol from biodiesel¬derived crude glycerol by Enterobacter aerogenes TISTR1468, under micro-aerobic and anaerobic conditions, was investigated. The experimental results showed that micro-aerobic conditions were more favorable for cellular growth (4.0 g/L DCW), ethanol production (20.7 g/L) as well as the ethanol yield (0.47 g/g glycerol) than anaerobic conditions (1.2 g/L DCW, 6.3 g/L ethanol and 0.72 g/g glycerol, respectively). Crude glycerol (100 g/L) was consumed completely with the rate of 1.80 g/L/h. Two-stage fermentation (combination of micro-aerobic and anaerobic condition) exhibited higher ethanol production (24.5 g/L) than using one-stage fermentation (either micro-aerobic or anaerobic condition. The two- stage configuration, exhibited slightly higher crude glycerol consumption rate (1.81 g/L/h), as well as ethanol yield (0.56 g/g) than the one-stage configuration. Therefore, two-stage process was selected for ethanol production from E. aerogenes TISTR1468 in scale-up studies.
Abstract: In this study, a network quality of service (QoS)
evaluation system was proposed. The system used a combination of
fuzzy C-means (FCM) and regression model to analyse and assess the
QoS in a simulated network. Network QoS parameters of multimedia
applications were intelligently analysed by FCM clustering
algorithm. The QoS parameters for each FCM cluster centre were
then inputted to a regression model in order to quantify the overall
QoS. The proposed QoS evaluation system provided valuable
information about the network-s QoS patterns and based on this
information, the overall network-s QoS was effectively quantified.
Abstract: Recent developments in automotive technology are focused on economy, comfort and safety. Vehicle tracking and collision detection systems are attracting attention of many investigators focused on safety of driving in the field of automotive mechatronics. In this paper, a vision-based vehicle detection system is presented. Developed system is intended to be used in collision detection and driver alert. The system uses RGB images captured by a camera in a car driven in the highway. Images captured by the moving camera are used to detect the moving vehicles in the image. A vehicle ahead of the camera is detected in daylight conditions. The proposed method detects moving vehicles by subtracting successive images. Plate height of the vehicle is determined by using a plate recognition algorithm. Distance of the moving object is calculated by using the plate height. After determination of the distance of the moving vehicle relative speed of the vehicle and Time-to-Collision are calculated by using distances measured in successive images. Results obtained in road tests are discussed in order to validate the use of the proposed method.
Abstract: In this paper a special kind of buffer management policy is studied where the packet are preempted even when sufficient space is available in the buffer for incoming packets. This is done to congestion for future incoming packets to improve QoS for certain type of packets. This type of study has been done in past for ATM type of scenario. We extend the same for heterogeneous traffic where data rate and size of the packets are very versatile in nature. Typical example of this scenario is the buffer management in Differentiated Service Router. There are two aspects that are of interest. First is the packet size: whether all packets have same or different sizes. Second aspect is the value or space priority of the packets, do all packets have the same space priority or different packets have different space priorities. We present two types of policies to achieve QoS goals for packets with different priorities: the push out scheme and the expelling scheme. For this work the scenario of packets of variable length is considered with two space priorities and main goal is to minimize the total weighted packet loss. Simulation and analytical studies show that, expelling policies can outperform the push out policies when it comes to offering variable QoS for packets of two different priorities and expelling policies also help improve the amount of admissible load. Some other comparisons of push out and expelling policies are also presented using simulations.
Abstract: The aim of a biological model is to understand the
integrated structure and behavior of complex biological systems as a
function of the underlying molecular networks to achieve simulation
and forecast of their operation. Although several approaches have
been introduced to take into account structural and environment
related features, relatively little attention has been given to represent
the behavior of biological systems. The Abstract Biological Process
(ABP) model illustrated in this paper is an object-oriented model
based on UML (the standard object-oriented language). Its main
objective is to bring into focus the functional aspects of the
biological system under analysis.
Abstract: This paper focuses on a critical component of the situational awareness (SA), the neural control of autonomous constant depth flight of an autonomous underwater vehicle (AUV). Autonomous constant depth flight is a challenging but important task for AUVs to achieve high level of autonomy under adverse conditions. The fundamental requirement for constant depth flight is the knowledge of the depth, and a properly designed controller to govern the process. The AUV, named VORAM, is used as a model for the verification of the proposed hybrid control algorithm. Three neural network controllers, named NARMA-L2 controllers, are designed for fast and stable diving maneuvers of chosen AUV model. This hybrid control strategy for chosen AUV model has been verified by simulation of diving maneuvers using software package Simulink and demonstrated good performance for fast SA in real-time searchand- rescue operations.
Abstract: The usefulness of weaning foods to meet the nutrient
needs of children is well recognized, and most of them are precooked
roller dried mixtures of cereal and/or legume flours which posses a
high viscosity and bulk when reconstituted. The objective of this study
was to formulate composite weaning foods using cereals, malted
legumes and vegetable powders and analyze them for nutrients,
functional properties and sensory attributes. Selected legumes (green
gram and lentil) were germinated, dried and dehulled. Roasted wheat,
rice, carrot powder and skim milk powder also were used. All the
ingredients were mixed in different proportions to get four
formulations, made into 30% slurry and dried in roller drier. The
products were analyzed for proximate principles, mineral content,
functional and sensory qualities. The results of analysis showed
following range of constituents per 100g of formulations on dry
weight basis, protein, 18.1-18.9 g ; fat, 0.78-1.36 g ; iron, 5.09-6.53
mg; calcium, 265-310 mg. The lowest water absorption capacity was
in case of wheat green gram based and the highest was in rice lentil
based sample. Overall sensory qualities of all foods were graded as
“good" and “very good" with no significant differences. The results
confirm that formulated weaning foods were nutritionally superior,
functionally appropriate and organoleptically acceptable.
Abstract: The present paper is oriented to problems of simulation of anticipatory systems, namely those that use simulation models for the aid of anticipation. A certain analogy between use of simulation and imagining will be applied to make the explication more comprehensible. The paper will be completed by notes of problems and by some existing applications. The problems consist in the fact that simulation of the mentioned anticipatory systems end is simulation of simulating systems, i.e. in computer models handling two or more modeled time axes that should be mapped to real time flow in a nondescent manner. Languages oriented to objects, processes and blocks can be used to surmount the problems.
Abstract: It-s known that incorporating prior knowledge into support
vector regression (SVR) can help to improve the approximation
performance. Most of researches are concerned with the incorporation
of knowledge in form of numerical relationships. Little work,
however, has been done to incorporate the prior knowledge on the
structural relationships among the variables (referred as to Structural
Prior Knowledge, SPK). This paper explores the incorporation of SPK
in SVR by constructing appropriate admissible support vector kernel
(SV kernel) based on the properties of reproducing kernel (R.K).
Three-levels specifications of SPK are studies with the corresponding
sub-levels of prior knowledge that can be considered for the method.
These include Hierarchical SPK (HSPK), Interactional SPK (ISPK)
consisting of independence, global and local interaction, Functional
SPK (FSPK) composed of exterior-FSPK and interior-FSPK. A
convenient tool for describing the SPK, namely Description Matrix
of SPK is introduced. Subsequently, a new SVR, namely Motivated
Support Vector Regression (MSVR) whose structure is motivated
in part by SPK, is proposed. Synthetic examples show that it is
possible to incorporate a wide variety of SPK and helpful to improve
the approximation performance in complex cases. The benefits of
MSVR are finally shown on a real-life military application, Air-toground
battle simulation, which shows great potential for MSVR to
the complex military applications.