Abstract: This paper is introduced a modification to Diffie-
Hellman protocol to be applicable on the decimal numbers, which
they are the numbers between zero and one. For this purpose we
extend the theory of the congruence. The new congruence is over
the set of the real numbers and it is called the “real congruence"
or the “real modulus". We will refer to the existing congruence by
the “integer congruence" or the “integer modulus". This extension
will define new terms and redefine the existing terms. As the
properties and the theorems of the integer modulus are extended as
well. Modified Diffie-Hellman key exchange protocol is produced a
sharing, secure and decimal secret key for the the cryptosystems that
depend on decimal numbers.
Abstract: This study deals with Computational Fluid Dynamics
(CFD) studies of the interactions between the air flow and louvered
fins which equipped the automotive heat exchangers. 3D numerical
simulation results are obtained by using the ANSYS Fluent 13.0 code
and compared to experimental data. The paper studies the effect of
louver angle and louver pitch geometrical parameters, on overall
thermal hydraulic performances of louvered fins.
The comparison between CFD simulations and experimental data
show that established 3-D CFD model gives a good agreement. The
validation agrees, with about 7% of deviation respectively of friction
and Colburn factors to experimental results. As first, it is found that
the louver angle has a strong influence on the heat transfer rate. Then,
louver angle and louver pitch variation of the louvers and their effects
on thermal hydraulic performances are studied. In addition to this
study, it is shown that the second half of the fin takes has a
significant contribution on pressure drop increase without any
increase in heat transfer.
Abstract: The objective of the presented work is to implement the Kalman Filter into an application that reduces the influence of the environmental changes over the robot expected to navigate over a terrain of varying friction properties. The Discrete Kalman Filter is used to estimate the robot position, project the estimated current state ahead at time through time update and adjust the projected estimated state by an actual measurement at that time via the measurement update using the data coming from the infrared sensors, ultrasonic sensors and the visual sensor respectively. The navigation test has been performed in a real world environment and has been found to be robust.
Abstract: Thanks to the interdisciplinary nature of crises, the
position of researchers in that field is rather difficult. Very often the
traditional methods of research cannot be applied there. The article is
aimed at the changes in crises research. It describes the substance of
individual changes and emphasizes the shift in research approaches
to the crisis.
Abstract: This paper simulates the ad-hoc mesh network in rural areas, where such networks receive great attention due to their cost, since installing the infrastructure for regular networks in these areas is not possible due to the high cost. The distance between the communicating nodes is the most obstacles that the ad-hoc mesh network will face. For example, in Terranet technology, two nodes can communicate if they are only one kilometer far from each other. However, if the distance between them is more than one kilometer, then each node in the ad-hoc mesh networks has to act as a router that forwards the data it receives to other nodes. In this paper, we try to find the critical number of nodes which makes the network fully connected in a particular area, and then propose a method to enhance the intermediate node to accept to be a router to forward the data from the sender to the receiver. Much work was done on technological changes on peer to peer networks, but the focus of this paper will be on another feature which is to find the minimum number of nodes needed for a particular area to be fully connected and then to enhance the users to switch on their phones and accept to work as a router for other nodes. Our method raises the successful calls to 81.5% out of 100% attempt calls.
Abstract: In very narrow pathways, the speed of sound propagation and the phase of sound waves change due to the air viscosity. We have developed a new finite element method (FEM) that includes the effects of air viscosity for modeling a narrow sound pathway. This method is developed as an extension of the existing FEM for porous sound-absorbing materials. The numerical calculation results for several three-dimensional slit models using the proposed FEM are validated against existing calculation methods.
Abstract: Soil stabilization has been widely used to improve
soil strength and durability or to prevent erosion and dust generation.
Generally to reduce problems of clayey soils in engineering work and
to stabilize these soils additional materials are used. The most
common materials are lime, fly ash and cement. Using this materials,
although improve soil property , but in some cases due to financial
problems and the need to use special equipment are limited .One of
the best methods for stabilization clayey soils is neutralization the
clay particles. For this purpose we can use ion exchange materials.
Ion exchange solution like CBR plus can be used for soil
stabilization. One of the most important things in using CBR plus is
determination the amount of this solution for various soils with
different properties. In this study a laboratory experiment is conduct
to evaluate the ion exchange capacity of three soils with various
plasticity index (PI) to determine amount or required CBR plus
solution for soil stabilization.
Abstract: The paper attempts a synthesis of problems relating to
municipal waste management in Nigeria and proposes a conceptual
knowledge management approach for tackling municipal waste
problems in cities across Nigeria. The application of knowledge
management approach and strategy is crucial for inculcating a change
of attitude towards improving the management of waste. The paper is
a review of existing literatures, information, policies and data on
municipal waste management in Nigeria. The inefficient management
of waste by individuals, households, consumers and waste
management companies can be attributed to inadequate information
on waste management benefits, lack of producers- involvement in
waste management as well as poor implementation of government
policies. The paper presents an alternative approach providing
solutions promoting efficient municipal waste management.
Abstract: Over the past decade, mobile has experienced a
revolution that will ultimately change the way we communicate.All
these technologies have a common denominator exploitation of
computer information systems, but their operation can be tedious
because of problems with heterogeneous data sources.To overcome
the problems of heterogeneous data sources, we propose to use a
technique of adding an extra layer interfacing applications of
management or supervision at the different data sources.This layer
will be materialized by the implementation of a mediator between
different host applications and information systems frequently used
hierarchical and relational manner such that the heterogeneity is
completely transparent to the VoIP platform.
Abstract: This paper presents the results of a comprehensive
investigation of five blackouts that occurred on 28 August to 8
September 2011 due to bushing failures of the 132/33 kV, 125 MVA
transformers at JBB Ali Grid station. The investigation aims to
explore the root causes of the bushing failures and come up with
recommendations that help in rectifying the problem and avoiding the
reoccurrence of similar type of incidents. The incident reports about
the failed bushings and the SCADA reports at this grid station were
examined and analyzed. Moreover, comprehensive power quality
field measurements at ten 33/11 kV substations (S/Ss) in JBB Ali
area were conducted, and frequency scans were performed to verify
any harmonic resonance frequencies due to power factor correction
capacitors. Furthermore, the daily operations of the on-load tap
changers (OLTCs) of both the 125 MVA and 20 MVA transformers
at JBB Ali Grid station have been analyzed. The investigation
showed that the five bushing failures were due to a local problem, i.e.
internal degradation of the bushing insulation. This has been
confirmed by analyzing the time interval between successive OLTC
operations of the faulty grid transformers. It was also found that
monitoring the number of OLTC operations can help in predicting
bushing failure.
Abstract: The study and development of an innovative material
for building insulation is really important for a sustainable society in order to improve comfort and reducing energy consumption. The aim of this work is the development of insulating panels for
sustainable buildings based on an innovative material made by
cardboard and Phase Change Materials (PCMs).
The research has consisted in laboratory tests whose purpose has been the obtaining of the required properties for insulation panels: lightweight, porous structures and mechanical resistance. PCMs have been used for many years in the building industry as
smart insulation technology because of their properties of storage and release high quantity of latent heat at useful specific temperatures [1]- [2].
The integration of PCMs into cellulose matrix during the waste paper recycling process has been developed in order to obtain a
composite material.
Experiments on the productive process for the realization of insulating panels were done in order to make the new material
suitable for building application. The addition of rising agents
demonstrated the possibility to obtain a lighter structure with better
insulation properties.
Several tests were conducted to verify the new panel properties. The results obtained have shown the possibility to realize an
innovative and sustainable material suitable to replace insulating panels currently used.
Abstract: Experiments with pumpkin-rowanberry marmalade
candies were carried out at the Faculty of Food Technology of the
Latvia University of Agriculture. The objective of this investigation
was to evaluate the quality changes of pumpkin-rowanberry
marmalade candies packed in different packaging materials during
the storage of 15 weeks, and to find the most suitable packaging
material for prolongation of low sugar marmalade candies shelf-life.
An active packaging in combination with modified atmosphere
(MAP, CO2 100%) was examined and compared with traditional
packaging in air ambiance. Polymer Multibarrier 60 and paper bags
were used. Influence of iron based oxygen absorber in sachets of 500
cc obtained from Mitsubishi Gas Chemical Europe Ageless® on the
marmalade candies’ quality was tested during shelf life. Samples of
80±5 g were packaged in polymer pouches (110 mm x 110 mm),
hermetically sealed by MULTIVAC C300 vacuum chamber machine,
and stored in a room temperature +21±0.5 °C. The physiochemical
properties –moisture content, hardness, aw, pH, changes of
atmosphere content (CO2 and O2), ascorbic acid, total carotenoids,
total phenols in headspace of packs, and microbial conditions were
analysed before packaging and in the 1st, 3rd , 5th, 8th, 11th and 15th
weeks of storage.
Abstract: This paper proposes a simple model of economic geography within the Dixit-Stiglitz-Iceberg framework that may be used to analyze migration patterns among three cities. The cost–benefit tradeoffs affecting incentives for three types of migration, including echelon migration, are discussed. This paper develops a tractable, heterogeneous-agent, general equilibrium model, where agents share constant human capital, and explores the relationship between the benefits of echelon migration and gross human capital. Using Chinese numerical solutions, we study the manifestation of echelon migration and how it responds to changes in transportation cost and elasticity of substitution. Numerical results demonstrate that (i) there are positive relationships between a migration-s benefit-and-wage ratio, (ii) there are positive relationships between gross human capital ratios and wage ratios as to origin and destination, and (iii) we identify 13 varieties of human capital convergence among cities. In particular, this model predicts population shock resulting from the processes of migration choice and echelon migration.
Abstract: Random Oracle Model (ROM) is an effective method
for measuring the practical security of cryptograph. In this paper, we
try to use it into information hiding system (IHS). Because IHS has its
own properties, the ROM must be modified if it is used into IHS.
Firstly, we fully discuss why and how to modify each part of ROM
respectively. The main changes include: 1) Divide the attacks that IHS
may be suffered into two phases and divide the attacks of each phase
into several kinds. 2) Distinguish Oracles and Black-boxes clearly. 3)
Define Oracle and four Black-boxes that IHS used. 4) Propose the
formalized adversary model. And 5) Give the definition of judge.
Secondly, based on ROM of IHS, the security against known original
cover attack (KOCA-KOCA-security) is defined. Then, we give an
actual information hiding scheme and prove that it is
KOCA-KOCA-secure. Finally, we conclude the paper and propose the
open problems of further research.
Abstract: Real-time 3D applications have to guarantee
interactive rendering speed. There is a restriction for the number of
polygons which is rendered due to performance of a graphics hardware
or graphics algorithms. Generally, the rendering performance will be
drastically increased when handling only the dynamic 3d models,
which is much fewer than the static ones. Since shapes and colors of
the static objects don-t change when the viewing direction is fixed, the
information can be reused. We render huge amounts of polygon those
cannot handled by conventional rendering techniques in real-time by
using a static object image and merging it with rendering result of the
dynamic objects. The performance must be decreased as a
consequence of updating the static object image including removing
an static object that starts to move, re-rending the other static objects
being overlapped by the moving ones. Based on visibility of the object
beginning to move, we can skip the updating process. As a result, we
enhance rendering performance and reduce differences of rendering
speed between each frame. Proposed method renders total
200,000,000 polygons that consist of 500,000 dynamic polygons and
the rest are static polygons in about 100 frames per second.
Abstract: In this paper, we propose a novel adaptive voltage control strategy for boost converter via Inverse LQ Servo-Control. Our presented strategy is based on an analytical formula of Inverse Linear Quadratic (ILQ) design method, which is not necessary to solve Riccati’s equation directly. The optimal and adaptive controller of the voltage control system is designed. The stability and the robust control are analyzed. Whereas, we can get the analytical solution for the optimal and robust voltage control is achieved through the natural angular velocity within a single parameter and we can change the responses easily via the ILQ control theory. Our method provides effective results as the stable responses and the response times are not drifted even if the condition is changed widely.
Abstract: The inability to implement the principles of good
corporate governance (GCG) as demonstrated in the surveys is due to
a number of constraints which can be classified into three; namely internal constraints, external constraints, and constraints coming
from the structure of ownership. The issues in the internal constraints
mentioned are related to the function of several elements of the company. As a business organization, corporation is unable to
achieve its goal to successfully implement GCG principles since it is
not support by its internal elements- functions. Two of several numbers of internal elements of a company are ethical work climate
and leadership style of the top management.
To prove the correlation between internal function of organization
(in this case ethical work climate and transformational leadership)
and the successful implementation of GCG principles, this study
proposes two hypotheses to be empirically tested on thirty surveyed organizations; eleven of which are state-owned companies and
nineteen are private companies. These thirty corporations are listed in
the Jakarta Stock Exchange. All state-owned companies in the
samples are those which have been privatized.
The research showed that internal function of organization give
support to the successful implementation of GCG principle. In this
research we can prove that : (i) ethical work climate has positive
significance of correlation with the successful implementation of
social awareness principle (one of principles on GCG) and, (ii) only
at the state-owned companies, transformational leadership have
positive significance effect to forming the ethical work climate.
Abstract: Within the framework of a method of the information
theory it is offered statistics and probabilistic model for definition of
cause-and-effect relations in the coupled multicomponent
subsystems. The quantitative parameter which is defined through
conditional and unconditional entropy functions is introduced. The
method is applied to the analysis of the experimental data on
dynamics of change of the chemical elements composition of plants
organs (roots, reproductive organs, leafs and stems). Experiment is
directed on studying of temporal processes of primary soil formation
and their connection with redistribution dynamics of chemical
elements in plant organs. This statistics and probabilistic model
allows also quantitatively and unambiguously to specify the
directions of the information streams on plant organs.
Abstract: Major social changes in the last century had significant impact on the Kazakh literature. Participants of the World War II, writers and poets imprisoned during the war, formed the Kazakh literature in emigration within the framework of 'Turkistan Legion'. This was a topic which remained closed until Kazakhstan gained its independence, though even after the independence, there were few research works done about the literature in emigration. The article studies the formation of the Kazakh literature in emigration, its prominent figures, its artistic heritage, and notes of emigration in works of poets and writers.
Abstract: Significant changes in oil and gas drilling have
emphasized the need to verify the integrity and reliability of drill
stem components. Defects are inevitable in cast components,
regardless of application; but if these defects go undetected, any
severe defect could cause down-hole failure.
One such defect is shrinkage porosity. Castings with lower level
shrinkage porosity (CB levels 1 and 2) have scattered pores and do
not occupy large volumes; so pressure testing and helium leak testing
(HLT) are sufficient for qualifying the castings. However, castings
with shrinkage porosity of CB level 3 and higher, behave erratically
under pressure testing and HLT making these techniques insufficient
for evaluating the castings- integrity.
This paper presents a case study to highlight how the radiography
technique is much more effective than pressure testing and HLT.