Abstract: One-way functions are functions that are easy to
compute but hard to invert. Their existence is an open conjecture; it
would imply the existence of intractable problems (i.e. NP-problems
which are not in the P complexity class).
If true, the existence of one-way functions would have an impact
on the theoretical framework of physics, in particularly, quantum
mechanics. Such aspect of one-way functions has never been shown
before.
In the present work, we put forward the following.
We can calculate the microscopic state (say, the particle spin in the
z direction) of a macroscopic system (a measuring apparatus
registering the particle z-spin) by the system macroscopic state (the
apparatus output); let us call this association the function F. The
question is: can we compute the function F in the inverse direction?
In other words, can we compute the macroscopic state of the system
through its microscopic state (the preimage F -1)?
In the paper, we assume that the function F is a one-way function.
The assumption implies that at the macroscopic level the Schrödinger
equation becomes unfeasible to compute. This unfeasibility plays a
role of limit of the validity of the linear Schrödinger equation.
Abstract: With the proliferation of mobile computing technology, mobile learning (m-learning) will play a vital role in the rapidly growing electronic learning market. However, the acceptance of m-learning by individuals is critical to the successful implementation of m-learning systems. Thus, there is a need to research the factors that affect users- intention to use m-learning. Based on an updated information system (IS) success model, data collected from 350 respondents in Taiwan were tested against the research model using the structural equation modeling approach. The data collected by questionnaire were analyzed to check the validity of constructs. Then hypotheses describing the relationships between the identified constructs and users- satisfaction were formulated and tested.
Abstract: Perishable goods constitute a large portion of retailer inventory and lose value with time due to deterioration and/or obsolescence. Retailers dealing with such goods required considering the factors of short shelf life and the dependency of sales on inventory displayed in determining optimal procurement policy. Many retailers follow the practice of using two bins - primary bin sales fresh items at a list price and secondary bin sales unsold items at a discount price transferred from primary bin on attaining certain age. In this paper, mathematical models are developed for primary bin and for secondary bin that maximizes profit with decision variables of order quantities, optimal review period and optimal selling price at secondary bin. The demand rates in two bins are assumed to be deterministic and dependent on displayed inventory level, price and age but independent of each other. The validity of the model is shown by solving an example and the sensitivity analysis of the model is also reported.
Abstract: A mathematical model of the surface roughness
has been developed by using response surface methodology
(RSM) in grinding of AISI D2 cold work tool steels. Analysis
of variance (ANOVA) was used to check the validity of the
model. Low and high value for work speed and feed rate are
decided from design of experiment. The influences of all
machining parameters on surface roughness have been
analyzed based on the developed mathematical model. The
developed prediction equation shows that both the feed rate
and work speed are the most important factor that influences
the surface roughness. The surface roughness was found to be
the lowers with the used of low feed rate and low work speed.
Accuracy of the best model was proved with the testing data.
Abstract: Power loss reduction is one of the main targets in power industry and so in this paper, the problem of finding the optimal configuration of a radial distribution system for loss reduction is considered. Optimal reconfiguration involves the selection of the best set of branches to be opened ,one each from each loop, for reducing resistive line losses , and reliving overloads on feeders by shifting the load to adjacent feeders. However ,since there are many candidate switching combinations in the system ,the feeder reconfiguration is a complicated problem. In this paper a new approach is proposed based on a simple optimum loss calculation by determining optimal trees of the given network. From graph theory a distribution network can be represented with a graph that consists a set of nodes and branches. In fact this problem can be viewed as a problem of determining an optimal tree of the graph which simultaneously ensure radial structure of each candidate topology .In this method the refined genetic algorithm is also set up and some improvements of algorithm are made on chromosome coding. In this paper an implementation of the algorithm presented by [7] is applied by modifying in load flow program and a comparison of this method with the proposed method is employed. In [7] an algorithm is proposed that the choice of the switches to be opened is based on simple heuristic rules. This algorithm reduce the number of load flow runs and also reduce the switching combinations to a fewer number and gives the optimum solution. To demonstrate the validity of these methods computer simulations with PSAT and MATLAB programs are carried out on 33-bus test system. The results show that the performance of the proposed method is better than [7] method and also other methods.
Abstract: Network reconfiguration in distribution system is realized by changing the status of sectionalizing switches to reduce the power loss in the system. This paper presents a new method which applies an artificial bee colony algorithm (ABC) for determining the sectionalizing switch to be operated in order to solve the distribution system loss minimization problem. The ABC algorithm is a new population based metaheuristic approach inspired by intelligent foraging behavior of honeybee swarm. The advantage of ABC algorithm is that it does not require external parameters such as cross over rate and mutation rate as in case of genetic algorithm and differential evolution and it is hard to determine these parameters in prior. The other advantage is that the global search ability in the algorithm is implemented by introducing neighborhood source production mechanism which is a similar to mutation process. To demonstrate the validity of the proposed algorithm, computer simulations are carried out on 14, 33, and 119-bus systems and compared with different approaches available in the literature. The proposed method has outperformed the other methods in terms of the quality of solution and computational efficiency.
Abstract: The thermal, epithermal and fast fluxes were
calculated for three irradiation channels at Egypt Second Research
Reactor (ETRR-2) using CITVAP code. The validity of the
calculations was verified by experimental measurements. There are
some deviations between measurements and calculations. This is due
to approximations in the calculation models used, homogenization of
regions, condensation of energy groups and uncertainty in nuclear
data used. Neutron flux data for the three irradiation channels are
now available. This would enable predicting the irradiation
conditions needed for future radioisotope production.
Abstract: The aim of this study was to investigate the correlation
between Facebook involvement and internet addiction. We sampled
577 university students in Taiwan and administered a survey of
Facebook usage, Facebook involvement scale (FIS), and internet
addiction scale. The FIS comprises three factors (salience, emotional
support, and amusement). Results showed that the Facebook
involvement scale had good reliability and validity. The correlation
between Facebook involvement and internet addiction was measured
at .395. This means that a higher degree of Facebook involvement
indicates a greater degree of psychological dependency on the internet,
and a greater propensity towards social withdrawal and other negative
psychological consequences associated with internet addiction.
Besides, the correlations between three factors of FIS (salience,
emotional support, and amusement) and internet addiction ranged
from .313-372, indicating that these neither of these factors (salience,
emotional support, and amusement) is more effective than the others in
predicting internet dependency.
Abstract: In this paper, we propose a hardware and software
design method for automotive Electronic Control Units (ECU)
considering the functional safety. The proposed ECU is considered for
the application to Electro-Mechanical Actuator systems and the
validity of the design method is shown by the application to the
Electro-Mechanical Brake (EMB) control system which is used as a
brake actuator in Brake-By-Wire (BBW) systems. The importance of a
functional safety-based design approach to EMB ECU design has been
emphasized because of its safety-critical functions, which are executed
with the aid of many electric actuators, sensors, and application
software. Based on hazard analysis and risk assessment according to
ISO26262, the EMB system should be ASIL-D-compliant, the highest
ASIL level. To this end, an external signature watchdog and an
Infineon 32-bit microcontroller TriCore are used to reduce risks
considering common-cause hardware failure. Moreover, a software
design method is introduced for implementing functional
safety-oriented monitoring functions based on an asymmetric dual
core architecture considering redundancy and diversity. The validity
of the proposed ECU design approach is verified by using the EMB
Hardware-In-the-Loop (HILS) system, which consists of the EMB
assembly, actuator ECU, a host PC, and a few debugging devices.
Furthermore, it is shown that the existing sensor fault tolerant control
system can be used more effectively for mitigating the effects of
hardware and software faults by applying the proposed ECU design
method.
Abstract: In this paper, we have developed an explicit analytical
drain current model comprising surface channel potential and
threshold voltage in order to explain the advantages of the proposed
Gate Stack Double Diffusion (GSDD) MOSFET design over the
conventional MOSFET with the same geometric specifications that
allow us to use the benefits of the incorporation of the high-k layer
between the oxide layer and gate metal aspect on the immunity of the
proposed design against the self-heating effects. In order to show the
efficiency of our proposed structure, we propose the simulation of the
power chopper circuit. The use of the proposed structure to design a
power chopper circuit has showed that the (GSDD) MOSFET can
improve the working of the circuit in terms of power dissipation and
self-heating effect immunity. The results so obtained are in close
proximity with the 2D simulated results thus confirming the validity
of the proposed model.
Abstract: Hexapod Machine Tool (HMT) is a parallel robot
mostly based on Stewart platform. Identification of kinematic
parameters of HMT is an important step of calibration procedure. In
this paper an algorithm is presented for identifying the kinematic
parameters of HMT using inverse kinematics error model. Based on
this algorithm, the calibration procedure is simulated. Measurement
configurations with maximum observability are decided as the first
step of this algorithm for a robust calibration. The errors occurring in
various configurations are illustrated graphically. It has been shown
that the boundaries of the workspace should be searched for the
maximum observability of errors. The importance of using
configurations with sufficient observability in calibrating hexapod
machine tools is verified by trial calibration with two different
groups of randomly selected configurations. One group is selected to
have sufficient observability and the other is in disregard of the
observability criterion. Simulation results confirm the validity of the
proposed identification algorithm.
Abstract: Object Relational Databases (ORDB) are complex in
nature than traditional relational databases because they combine the
characteristics of both object oriented concepts and relational
features of conventional databases. Design of an ORDB demands
efficient and quality schema considering the structural, functional
and componential traits. This internal quality of the schema is
assured by metrics that measure the relevant attributes. This is
extended to substantiate the understandability, usability and
reliability of the schema, thus assuring external quality of the
schema. This work institutes a formalization of ORDB metrics;
metric definition, evaluation methodology and the calibration of the
metric. Three ORDB schemas were used to conduct the evaluation
and the formalization of the metrics. The metrics are calibrated using
content and criteria related validity based on the measurability,
consistency and reliability of the metrics. Nominal and summative
scales are derived based on the evaluated metric values and are
standardized. Future works pertaining to ORDB metrics forms the
concluding note.
Abstract: The design of distributed systems involves dividing the system into partitions (or components) and then allocating these partitions to physical nodes. There have been several techniques proposed for both the partitioning and allocation processes. These existing techniques suffer from a number of limitations including lack of support for replication. Replication is difficult to use effectively but has the potential to greatly improve the performance of a distributed system. This paper presents a new technique technique for allocating objects in order to improve performance in a distributed system that supports replication. The performance of the proposed technique is demonstrated and tested on an example system. The performance of the new technique is compared with the performance of an existing technique in order to demonstrate both the validity and superiority of the new technique when developing a distributed system that can utilise object replication.
Abstract: To solve the quick and accurate level-adjusting
problem in the process of spacecraft precise mating, automatic leveling
and equalizing hoist device for spacecraft is developed. Based on
lifting point adjustment by utilizing XY-workbench, the leveling and
equalizing controller by a self-adaptive control algorithm is proposed.
By simulation analysis and lifting test using engineering prototype,
validity and reliability of the hoist device is verified, which can meet
the precision mating requirements of practical applications for
spacecraft.
Abstract: In this paper, we propose synchronization of an array of nonlinear systems with time delays. The array of systems is decomposed into isolated systems to establish appropriate Lyapunov¬Krasovskii functional. Using the Lyapunov-Krasovskii functional, a sufficient condition for the synchronization is derived in terms of LMIs(Linear Matrix Inequalities). Delayed feedback control gains are obtained by solving the sufficient condition. Numerical examples are given to show the validity the proposed method.
Abstract: Subjective loneliness describes people who feel a
disagreeable or unacceptable lack of meaningful social relationships,
both at the quantitative and qualitative level. The studies to be
presented tested an Italian 18-items self-report loneliness measure,
that included items adapted from scales previously developed,
namely a short version of the UCLA (Russell, Peplau and Cutrona,
1980), and the 11-items Loneliness scale by De Jong-Gierveld &
Kamphuis (JGLS; 1985). The studies aimed at testing the developed
scale and at verifying whether loneliness is better conceptualized as a
unidimensional (so-called 'general loneliness') or a bidimensional
construct, namely comprising the distinct facets of social and
emotional loneliness. The loneliness questionnaire included 2 singleitem
criterion measures of sad mood, and social contact, and asked
participants to supply information on a number of socio-demographic
variables. Factorial analyses of responses obtained in two
preliminary studies, with 59 and 143 Italian participants respectively,
showed good factor loadings and subscale reliability and confirmed
that perceived loneliness has clearly two components, a social and an
emotional one, the latter measured by two subscales, a 7-item
'general' loneliness subscale derived from UCLA, and a 6–item
'emotional' scale included in the JGLS. Results further showed that
type and amount of loneliness are related, negatively, to frequency of
social contacts, and, positively, to sad mood. In a third study data
were obtained from a nation-wide sample of 9.097 Italian subjects,
12 to about 70 year-olds, who filled the test on-line, on the Italian
web site of a large-audience magazine, Focus. The results again
confirmed the reliability of the component subscales, namely social,
emotional, and 'general' loneliness, and showed that they were
highly correlated with each other, especially the latter two.
Loneliness scores were significantly predicted by sex, age, education
level, sad mood and social contact, and, less so, by other variables –
e.g., geographical area and profession. The scale validity was
confirmed by the results of a fourth study, with elderly men and
women (N 105) living at home or in residential care units. The three
subscales were significantly related, among others, to depression, and
to various measures of the extension of, and satisfaction with, social
contacts with relatives and friends. Finally, a fifth study with 315
career-starters showed that social and emotional loneliness correlate
with life satisfaction, and with measures of emotional intelligence.
Altogether the results showed a good validity and reliability in the
tested samples of the entire scale, and of its components.
Abstract: The purpose of this research is to disentangle and
validate the underlying factorial-structure of Ecotourism Experiential
Value (EEV) measurement scale and subsequently investigate its
psychometric properties. The analysis was based on a sample of 225
eco-tourists, collected at the vicinity of Taman Negara National Park
(TNNP) via interviewer-administered questionnaire. Exploratory
factor analysis (EFA) was performed to determine the factorial
structure of EEV. Subsequently, to confirm and validate the factorial
structure and assess the psychometric properties of EEV,
confirmatory factor analysis (CFA) was executed. In addition, to
establish the nomological validity of EEV a structural model was
developed to examine the effect of EEV on Total Eco-tourist
Experience Quality (TEEQ). It is unveiled that EEV is a secondorder
six-factorial structure construct and it scale has adequately met
the psychometric criteria, thus could permit interpretation of results
confidently. The findings have important implications for future
research directions and management of ecotourism destination.
Abstract: In this paper, verified extension of the Ostrowski method which calculates the enclosure solutions of a given nonlinear equation is introduced. Also, error analysis and convergence will be discussed. Some implemented examples with INTLAB are also included to illustrate the validity and applicability of the scheme.
Abstract: Most of fuzzy clustering algorithms have some
discrepancies, e.g. they are not able to detect clusters with convex
shapes, the number of the clusters should be a priori known, they
suffer from numerical problems, like sensitiveness to the
initialization, etc. This paper studies the synergistic combination of
the hierarchical and graph theoretic minimal spanning tree based
clustering algorithm with the partitional Gath-Geva fuzzy clustering
algorithm. The aim of this hybridization is to increase the robustness
and consistency of the clustering results and to decrease the number
of the heuristically defined parameters of these algorithms to
decrease the influence of the user on the clustering results. For the
analysis of the resulted fuzzy clusters a new fuzzy similarity measure
based tool has been presented. The calculated similarities of the
clusters can be used for the hierarchical clustering of the resulted
fuzzy clusters, which information is useful for cluster merging and
for the visualization of the clustering results. As the examples used
for the illustration of the operation of the new algorithm will show,
the proposed algorithm can detect clusters from data with arbitrary
shape and does not suffer from the numerical problems of the
classical Gath-Geva fuzzy clustering algorithm.
Abstract: The purpose of this paper is to provide an overview on methodological aspects of the information technology outsourcing (ITO) surveys, in an attempt to improve the data quality and reporting in survey research. It is based on a review of thirty articles on ITO surveys and focuses on two commonly explored dimensions of ITO, namely what are outsourced and why should there be ITO. This study highlights weaknesses in ITO surveys including lack of a clear definition of population, lack of information regarding the sampling method used, not citing the response rate, no information pertaining to pilot testing of survey instrument and absence of information on internal validity in the use or reporting of surveys. This study represents an attempt with a limited scope to point to shortfalls in the use survey methodology in ITO, and thus raise awareness among researchers in enhancing the reliability of survey findings.