Abstract: Coordinated supply chain represents major challenges
for the different actors involved in it, because each agent responds to
individual interests. The paper presents a framework with the
reviewed literature regarding the system's decision structure and
nature of demand. Later, it characterizes an agri food supply chain in
the Central Region of Colombia, it responds to a decentralized
distribution system and a stochastic demand. Finally, the paper
recommends coordinating the chain based on shared information, and
mechanisms for each agent, as VMI (vendor-managed inventory)
strategy for farmer-buyer relationship, information system for
farmers and contracts for transportation service providers.
Abstract: Considering payload, reliability, security and operational lifetime as major constraints in transmission of images we put forward in this paper a steganographic technique implemented at the physical layer. We suggest transmission of Halftoned images (payload constraint) in wireless sensor networks to reduce the amount of transmitted data. For low power and interference limited applications Turbo codes provide suitable reliability. Ensuring security is one of the highest priorities in many sensor networks. The Turbo Code structure apart from providing forward error correction can be utilized to provide for encryption. We first consider the Halftoned image and then the method of embedding a block of data (called secret) in this Halftoned image during the turbo encoding process is presented. The small modifications required at the turbo decoder end to extract the embedded data are presented next. The implementation complexity and the degradation of the BER (bit error rate) in the Turbo based stego system are analyzed. Using some of the entropy based crypt analytic techniques we show that the strength of our Turbo based stego system approaches that found in the OTPs (one time pad).
Abstract: The storage of chemical fertilizers in concrete building often leads to durability problems due to chemical attack. The damage of concrete is mostly caused by certain ammonium salts. The main purpose of the research is to investigate the durability properties of concrete being exposed to ammonium nitrate solution. In this investigation, experiments are conducted on concrete type G50 and G60. The leaching process is achieved by the use of 20% concentration solution of ammonium nitrate. The durability properties investigated are water absorption, volume of permeable voids, and sorptivity. Compressive strength, pH value, and degradation depth are measured after a certain period of leaching. A decrease in compressive strength and an increase in porosity are found through the conducted experiments. Apart from that, the experimental data shows that pH value decreases with increased leaching time while the degradation depth of concrete increases with leaching time. By comparing concrete type G50 and G60, concrete type G60 is more resistant to ammonium nitrate attack.
Abstract: The article deals with numerical investigation of axisymmetric
subsonic air to air ejector. An analysis of flow and mixing
processes in cylindrical mixing chamber are made. Several modes
with different velocity and ejection ratio are presented. The mixing
processes are described and differences between flow in the initial
region of mixing and the main region of mixing are described. The
lengths of both regions are evaluated. Transition point and point
where the mixing processes are finished are identified. It was found
that the length of the initial region of mixing is strongly dependent on
the velocity ratio, while the length of the main region of mixing is
dependent on velocity ratio only slightly.
Abstract: Many single or multispan arch bridges are
strengthened with the addition of some kind of structural support
between adjacent arches of multispan or beside the arch barrel of a
single span to increase the strength of the overall structure. It was
traditionally formed by either placing loose rubble masonry blocks
between the arches and beside the arches or using mortar or concrete
to construct a more substantial structural bond between the spans. On
the other hand backing materials are present in some existing bridges.
Existing arch assessment procedures generally ignore the effects of
backing materials. In this paper an investigation of the effects of
backing on ratings for masonry arch bridges is carried out. It is
observed that increasing the overall lateral stability of the arch
system through the inclusion of structural backing results in an
enhanced failure load by reducing the likelihood of any tension
occurring at the top of the arch.
Abstract: In a complex project environment, project teams face
multi-dimensional communication problems that can ultimately lead
to project breakdown. Team Performance varies in Face-to-Face
(FTF) environment versus groups working remotely in a computermediated
communication (CMC) environment. A brief review of the
Input_Process_Output model suggested by James E. Driskell, Paul H.
Radtke and Eduardo Salas in “Virtual Teams: Effects of
Technological Mediation on Team Performance (2003)", has been
done to develop the basis of this research. This model theoretically
analyzes the effects of technological mediation on team processes,
such as, cohesiveness, status and authority relations, counternormative
behavior and communication. An empirical study
described in this paper has been undertaken to test the
“cohesiveness" of diverse project teams in a multi-national
organization. This study uses both quantitative and qualitative
techniques for data gathering and analysis. These techniques include
interviews, questionnaires for data collection and graphical data
representation for analyzing the collected data. Computer-mediated
technology may impact team performance because of difference in
cohesiveness among teams and this difference may be moderated by
factors, such as, the type of communication environment, the type of
task and the temporal context of the team. Based on the reviewed
model, sets of hypotheses are devised and tested. This research,
reports on a study that compared team cohesiveness among virtual
teams using CMC and non-CMC communication mediums. The
findings suggest that CMC can help virtual teams increase team
cohesiveness among their members, making CMC an effective
medium for increasing productivity and team performance.
Abstract: Powder of La0.6Sr0.4CoO3-α (LSCO) was synthesized
by a combined citrate-EDTA method. The as-synthesized LSCO
powder was calcined, respectively at temperatures of 800, 900 and
1000 °C with different heating/cooling rates which are 2, 5, 10 and
15 °C min-1. The effects of heat treatments on the phase formation of
perovskite phase of LSCO were investigated by powder X-ray
diffraction (XRD). The XRD patterns revealed that the rate of
5 °C min-1 is the optimum heating/cooling rate to obtain a single
perovskite phase of LSCO with calcination temperature of 800 °C.
This result was confirmed by a thermogravimetric analysis (TGA) as
it showed a complete decomposition of intermediate compounds to
form oxide material was also observed at 800 °C.
Abstract: New design of a grid for preparation of high density
granules with enhanced mechanical strength by granulation of
dispersed materials is suggested.
A method for hydrodynamic dimensioning of the grid depending
on granulation conditions, hydrodynamic regime of the operation,
dispersity and physicochemical characteristics of the materials to be
granulated was suggested.
The aim of the grid design is to solve the problems arising by the
granulation of disperse materials.
Abstract: The stone is a constituent part of the geological
structure of the Territory, introducing himself as a subject that has always interconnected human and environment in the development of a discourse of meanings and symbols that reflect elements realized in
different cultures and experiences.
This action meant that the first settlements and their areas of influence gained importance in the field of humanization and spatial
organization of the territory, not only for the appropriation that its
inhabitants did, but mainly because the community regardless of their
economic or social condition, used it as living space and cultural integration.
These factors become decisive in the characterization of the
landscape area in the northwest of Portugal, because the stone is a
material that appears not only in the natural landscape, but is also a strong element in humanized landscape, becoming this relation the
main characterization of the study area.
Abstract: Many studies have focused on the nonlinear analysis
of electroencephalography (EEG) mainly for the characterization of
epileptic brain states. It is assumed that at least two states of the
epileptic brain are possible: the interictal state characterized by a
normal apparently random, steady-state EEG ongoing activity; and
the ictal state that is characterized by paroxysmal occurrence of
synchronous oscillations and is generally called in neurology, a
seizure.
The spatial and temporal dynamics of the epileptogenic process is
still not clear completely especially the most challenging aspects of
epileptology which is the anticipation of the seizure. Despite all the
efforts we still don-t know how and when and why the seizure
occurs. However actual studies bring strong evidence that the
interictal-ictal state transition is not an abrupt phenomena. Findings
also indicate that it is possible to detect a preseizure phase.
Our approach is to use the neural network tool to detect interictal
states and to predict from those states the upcoming seizure ( ictal
state). Analysis of the EEG signal based on neural networks is used
for the classification of EEG as either seizure or non-seizure. By
applying prediction methods it will be possible to predict the
upcoming seizure from non-seizure EEG.
We will study the patients admitted to the epilepsy monitoring
unit for the purpose of recording their seizures. Preictal, ictal, and
post ictal EEG recordings are available on such patients for analysis
The system will be induced by taking a body of samples then
validate it using another. Distinct from the two first ones a third body
of samples is taken to test the network for the achievement of
optimum prediction. Several methods will be tried 'Backpropagation
ANN' and 'RBF'.
Abstract: In a travelling wave thermoacoustic device, the
regenerator sandwiched between a pair of (hot and cold) heat
exchangers constitutes the so-called thermoacoustic core, where the
thermoacoustic energy conversion from heat to acoustic power takes
place. The temperature gradient along the regenerator caused by the
two heat exchangers excites and maintains the acoustic wave in the
resonator. The devices are called travelling wave thermoacoustic
systems because the phase angle difference between the pressure and
velocity oscillation is close to zero in the regenerator. This paper
presents the construction and testing of a thermoacoustic engine
equipped with a ceramic regenerator, made from a ceramic material
that is usually used as catalyst substrate in vehicles- exhaust systems,
with fine square channels (900 cells per square inch). The testing
includes the onset temperature difference (minimum temperature
difference required to start the acoustic oscillation in an engine), the
acoustic power output, thermal efficiency and the temperature profile
along the regenerator.
Abstract: The adaptive power control of Code Division Multiple
Access (CDMA) communications using Remote Radio Head
(RRH) between multiple Unmanned Aerial Vehicles (UAVs) with
a link-budget based Signal-to-Interference Ratio (SIR) estimate is
applied to four inner loop power control algorithms. It is concluded
that Base Station (BS) can calculate not only UAV distance using
linearity between speed and Consecutive Transmit-Power-Control
Ratio (CTR) of Adaptive Step-size Closed Loop Power Control (ASCLPC),
Consecutive TPC Ratio Step-size Closed Loop Power Control
(CS-CLPC), Fixed Step-size Power Control (FSPC), but also UAV
position with Received Signal Strength Indicator (RSSI) ratio of
RRHs.
Abstract: The problem of ranking (rank regression) has become popular in the machine learning community. This theory relates to problems, in which one has to predict (guess) the order between objects on the basis of vectors describing their observed features. In many ranking algorithms a convex loss function is used instead of the 0-1 loss. It makes these procedures computationally efficient. Hence, convex risk minimizers and their statistical properties are investigated in this paper. Fast rates of convergence are obtained under conditions, that look similarly to the ones from the classification theory. Methods used in this paper come from the theory of U-processes as well as empirical processes.
Abstract: Removal of Methylene Blue (MB) from aqueous
solution by adsorbing it on Gypsum was investigated by batch
method. The studies were conducted at 25°C and included the effects
of pH and initial concentration of Methylene Blue. The adsorption
data was analyzed by using the Langmuir, Freundlich and Tempkin
isotherm models. The maximum monolayer adsorption capacity was
found to be 36 mg of the dye per gram of gypsum. The data were
also analyzed in terms of their kinetic behavior and was found to
obey the pseudo second order equation.
Abstract: In article the data of pre-clinical researches of Ramon
preparation is described. Antitumor activity of Ramon has been
studied on 19 strains of transplantated tumors of different
hystogenesis.
Abstract: In this work, we perform numerical simulation of fluid
mixing in a floor-grooved micro-channel with wavy sidewalls which
may impose perturbation on the helical flow induced by the slanted
grooves on the channel floor. The perturbation is caused by separation
vortices in the recesses of the wavy-walled channel as the Reynolds
number is large enough. The results show that the effects of the wavy
sidewalls of the present micromixer on the enhancement of fluid
mixing increase with the increase of Reynolds number. The degree of
mixing increases with the increase of the corrugation angle, until the
angle is greater than 45 degrees. Besides, the pumping pressure of the
micromixer increases with the increase of the corrugation angle
monotonically. Therefore, we would suggest setting the corrugation
angle of the wavy sidewalls to be 45 degrees.
Abstract: This paper investigates experimental studies on
vibration suppression for a cantilever beam using an
Electro-Rheological (ER) sandwich shock absorber. ER fluid (ERF) is a
class of smart materials that can undergo significant reversible changes
immediately in its rheological and mechanical properties under the
influence of an applied electric field. Firstly, an ER sandwich beam is
fabricated by inserting a starch-based ERF into a hollow composite
beam. At the same time, experimental investigations are focused on the
frequency response of the ERF sandwich beam. Second, the ERF
sandwich beam is attached to a cantilever beam to become as a shock
absorber. Finally, a fuzzy semi-active vibration control is designed to
suppress the vibration of the cantilever beam via the ERF sandwich
shock absorber. To check the consistency of the proposed fuzzy
controller, the real-time implementation validated the performance of
the controller.
Abstract: This paper studies mixed-mode fracture mechanics in
rock based on experimental and numerical analyses. Experiments
were performed on sharp-cracked specimens using the modified
Arcan specimen test loading device. The modified Arcan specimen
test was, in association with a special loading device, an appropriate
apparatus for experimental mixed-mode fracture analysis. By
varying the loading angle from 0° to 90°, pure mode-I, pure mode-II
and a wide range of mixed-mode data were obtained experimentally.
Using the finite element results, correction factors applied to the
rectangular fracture specimen. By employing experimentally
measured critical loads and the aid of the finite element method,
mixed-mode fracture toughness for the limestone under consideration
determined.
Abstract: The Long-range Energy and Alternatives Planning (LEAP) energy planning system has been developed for South Africa, for the 2005 base year and a limited number of plausible future scenarios that may have significant implications (negative or positive) in terms of environmental impacts. The system quantifies the national energy demand for the domestic, commercial, transport, industry and agriculture sectors, the supply of electricity and liquid fuels, and the resulting emissions. The South African National Energy Research Institute (SANERI) identified the need to develop an environmental assessment tool, based on the LEAP energy planning system, to provide decision-makers and stakeholders with the necessary understanding of the environmental impacts associated with different energy scenarios. A comprehensive analysis of indicators that are used internationally and in South Africa was done and the available data was accessed to select a reasonable number of indicators that could be utilized in energy planning. A consultative process was followed to determine the needs of different stakeholders on the required indicators and also the most suitable form of reporting. This paper demonstrates the application of Energy Environmental Sustainability Indicators (EESIs) as part of the developed tool, which assists with the identification of the environmental consequences of energy generation and use scenarios and thereby promotes sustainability, since environmental considerations can then be integrated into the preparation and adoption of policies, plans, programs and projects. Recommendations are made to refine the tool further for South Africa.
Abstract: This paper presents a integer frequency offset (IFO)
estimation scheme for the 3GPP long term evolution (LTE) downlink
system. Firstly, the conventional joint detection method for IFO and
sector cell index (CID) information is introduced. Secondly, an IFO
estimation without explicit sector CID information is proposed, which
can operate jointly with the proposed IFO estimation and reduce
the time delay in comparison with the conventional joint method.
Also, the proposed method is computationally efficient and has almost
similar performance in comparison with the conventional method over
the Pedestrian and Vehicular channel models.