Abstract: Dr Eliyahu Goldratt has done the pioneering work in
the development of Theory of Constraints. Since then, many more
researchers around the globe are working to enhance this body of
knowledge. In this paper, an attempt has been made to compile the
salient features of this theory from the work done by Goldratt and
other researchers. This paper will provide a good starting point to the
potential researchers interested to work in Theory of Constraints. The
paper will also help the practicing managers by clarifying their
concepts on the theory and will facilitate its successful
implementation in their working areas.
Abstract: This paper presents a unified approach based graph
theory and system theory postulates for the modeling and analysis
of Simple open cycle Gas turbine system. In the present paper, the
simple open cycle gas turbine system has been modeled up to its subsystem
level and system variables have been identified to develop the
process subgraphs. The theorems and algorithms of the graph theory
have been used to represent behavioural properties of the system like
rate of heat and work transfers rates, pressure drops and temperature
drops in the involved processes of the system. The processes have
been represented as edges of the process subgraphs and their limits
as the vertices of the process subgraphs. The system across variables
and through variables has been used to develop terminal equations of
the process subgraphs of the system. The set of equations developed
for vertices and edges of network graph are used to solve the system
for its process variables.
Abstract: Actual load, material characteristics and other
quantities often differ from the design values. This can cause worse
function, shorter life or failure of a civil engineering structure, a
machine, vehicle or another appliance. The paper shows main causes
of the uncertainties and deviations and presents a systematic
approach and efficient tools for their elimination or mitigation of
consequences. Emphasis is put on the design stage, which is most
important for reliability ensuring. Principles of robust design and
important tools are explained, including FMEA, sensitivity analysis
and probabilistic simulation methods. The lifetime prediction of
long-life objects can be improved by long-term monitoring of the
load response and damage accumulation in operation. The condition
evaluation of engineering structures, such as bridges, is often based
on visual inspection and verbal description. Here, methods based on
fuzzy logic can reduce the subjective influences.
Abstract: Modern organizations operate under the pressure of
dynamic and often unpredictable changes, both in external and
internal environment. Market success, in this context, requires a
particular competence in the form of flexibility, interpreted here both
on the level of individuals and on the level of organization. This
paper addresses the changes taking place in the sphere of
employment, as observed in economic entities operating on Polish
market. Based on own empirical studies, the authors focus on the
progressing trend of ‘flexibilization’ of employment, particularly in
the context of transformations in organizational structure, designed to
facilitate the transition into management by projects and
differentiation of labor forms.
Abstract: Artificial Neural Network (ANN) has been
extensively used for classification of heart sounds for its
discriminative training ability and easy implementation. However, it
suffers from overparameterization if the number of nodes is not
chosen properly. In such cases, when the dataset has redundancy
within it, ANN is trained along with this redundant information that
results in poor validation. Also a larger network means more
computational expense resulting more hardware and time related
cost. Therefore, an optimum design of neural network is needed
towards real-time detection of pathological patterns, if any from heart
sound signal. The aims of this work are to (i) select a set of input
features that are effective for identification of heart sound signals and
(ii) make certain optimum selection of nodes in the hidden layer for a
more effective ANN structure. Here, we present an optimization
technique that involves Singular Value Decomposition (SVD) and
QR factorization with column pivoting (QRcp) methodology to
optimize empirically chosen over-parameterized ANN structure.
Input nodes present in ANN structure is optimized by SVD followed
by QRcp while only SVD is required to prune undesirable hidden
nodes. The result is presented for classifying 12 common
pathological cases and normal heart sound.
Abstract: In this study, a software has been developed to predict
the optimum conditions for drying of cotton based yarn bobbins in a
hot air dryer. For this purpose, firstly, a suitable drying model has
been specified using experimental drying behavior for different
values of drying parameters. Drying parameters in the experiments
were drying temperature, drying pressure, and volumetric flow rate of
drying air. After obtaining a suitable drying model, additional curve
fittings have been performed to obtain equations for drying time and
energy consumption taking into account the effects of drying
parameters. Then, a software has been developed using Visual Basic
programming language to predict the optimum drying conditions for
drying time and energy consumption.
Abstract: In this paper an attempt has been made to correlate the usefulness of electrodes made through powder metallurgy (PM) in comparison with conventional copper electrode during electric discharge machining. Experimental results are presented on electric discharge machining of AISI D2 steel in kerosene with copper tungsten (30% Cu and 70% W) tool electrode made through powder metallurgy (PM) technique and Cu electrode. An L18 (21 37) orthogonal array of Taguchi methodology was used to identify the effect of process input factors (viz. current, duty cycle and flushing pressure) on the output factors {viz. material removal rate (MRR) and surface roughness (SR)}. It was found that CuW electrode (made through PM) gives high surface finish where as the Cu electrode is better for higher material removal rate.
Abstract: Development of cities and villages, agricultural farms
and industrial regions in abutment and/or in the course of streams and
rivers or in prone flood lands has been caused more notations in
hydrology problems and city planning topics. In order to protection
of cities against of flood damages, embankment construction is a
desired and scientific method. The cities that located in arid zones
may damage by floods periodically. Zavvareh city in Ardestan
township(Isfahan province) with 7704 people located in Ardestan
plain that has been damaged by floods that have flowed from
dominant mountainous watersheds in past years with regard to return
period. In this study, according to flowed floods toward Zavvareh
city, was attempt to plan suitable hydraulic structures such as canals,
bridges and collectors in order to collection, conduction and
depletion of city surface runoff.
Abstract: In this paper, the experimental design of using the
Taguchi method is employed to optimize the processing parameters in
the plasma arc surface hardening process. The processing parameters
evaluated are arc current, scanning velocity and carbon content of
steel. In addition, other significant effects such as the relation between
processing parameters are also investigated. An orthogonal array,
signal-to-noise (S/N) ratio and analysis of variance (ANOVA) are
employed to investigate the effects of these processing parameters.
Through this study, not only the hardened depth increased and surface
roughness improved, but also the parameters that significantly affect
the hardening performance are identified. Experimental results are
provided to verify the effectiveness of this approach.
Abstract: Capacity and efficiency of any refrigerating system
diminish rapidly as the difference between the evaporating and
condensing temperature is increased by a reduction in the evaporator
temperature. The single stage vapour compression refrigeration
system using various refrigerants are limited to an evaporator
temperature of -40 0C. Below temperature of -40 0C the either
cascade refrigeration system or multi stage vapour compression
system is employed. Present work describes thermal design of
condenser (HTS), cascade condenser and evaporator (LTS) of
R404A-R508B and R410A-R23 cascade refrigeration system. Heat
transfer area of condenser, cascade condenser and evaporator for
both systems are compared and the effect of condenser and
evaporator temperature on heat-transfer area for both systems is
studied under same operating condition. The results shows that the
required heat-transfer area of condenser and cascade condenser for
R410A-R23 cascade system is lower than the R404A-R508B cascade
system but heat transfer area of evaporator is similar for both the
system. The heat transfer area of condenser and cascade condenser
decreases with increase in condenser temperature (Tc), whereas the
heat transfer area of cascade condenser and evaporator increases with
increase in evaporator temperature (Te).
Abstract: The increasing influence of traffic on building
objects and people residing in them should be taken into account in
diagnosis and design. Users of buildings expect that vibrations
occurring in their environment, will not only lead to damage to the
building or its accelerated wear, but neither would affect the required
comfort in rooms designed to accommodate people. This article
describes the methods and principles useful in designing and building
diagnostics located near transportation routes, with particular
emphasis on the impact of traffic vibration on people in buildings. It
also describes the procedures used in obtaining information about the
parameters of vibrations in different cases of diagnostics and design.
A universal algorithm of procedure in diagnostics and design of
buildings taking into account assurance of human vibration comfort
of people residing in the these buildings was presented.
Abstract: Musculoskeletal problems are common in high
performance dance population. This study attempts to identify lower
extremity muscle flexibility parameters prevailing among
bharatanatyam dancers and analyze if there is any significant
difference exist between normal and injured dancers in flexibility
parameters. Four hundred and one female dancers and 17 male
dancers were participated in this study. Flexibility parameters
(hamstring tightness, hip internal and external rotation and
tendoachilles in supine and sitting posture) were measured using
goniometer. Results of our study it is evident that injured female
bharathnatyam dancers had significantly (p < 0.05) high hamstring
tightness on left side lower extremity compared to normal female
dancers. The range of motion for left tendoachilles was significantly
(p < 0.05) high for the normal female group when compared to
injured dancers during supine lying posture. Majority of the injured
dancers had high hamstring tightness that could be a possible reason
for pain and MSDs.