Abstract: In this paper we present a new method for coin
identification. The proposed method adopts a hybrid scheme using
Eigenvalues of covariance matrix, Circular Hough Transform (CHT)
and Bresenham-s circle algorithm. The statistical and geometrical
properties of the small and large Eigenvalues of the covariance
matrix of a set of edge pixels over a connected region of support are
explored for the purpose of circular object detection. Sparse matrix
technique is used to perform CHT. Since sparse matrices squeeze
zero elements and contain only a small number of non-zero elements,
they provide an advantage of matrix storage space and computational
time. Neighborhood suppression scheme is used to find the valid
Hough peaks. The accurate position of the circumference pixels is
identified using Raster scan algorithm which uses geometrical
symmetry property. After finding circular objects, the proposed
method uses the texture on the surface of the coins called texton,
which are unique properties of coins, refers to the fundamental micro
structure in generic natural images. This method has been tested on
several real world images including coin and non-coin images. The
performance is also evaluated based on the noise withstanding
capability.
Abstract: Rockfall is a kind of irregular geological disaster. Its
destruction time, space and movements are highly random. The impact
force is determined by the way and velocity rocks move. The
movement velocity of a rockfall depends on slope gradient of its
moving paths, height, slope surface roughness and rock shapes. For
effectively mitigate and prevent disasters brought by rockfalls, it is
required to precisely calculate the moving paths of a rockfall so as to
provide the best protective design. This paper applies Colorado
Rockfall Simulation Program (CRSP) as our study tool to discuss the
impact of slope shape and surface roughness on the moving paths of a
single rockfall. The analytical results showed that the slope, m=1:1,
acted as the threshold for rockfall bounce height on a monoclinal slight
slope. When JRC ´╝£ 1.2, movement velocity reduced and bounce
height increased as JCR increased. If slope fixed and JRC increased,
the bounce height of rocks increased gradually with reducing
movement velocity. Therefore, the analysis on the moving paths of
rockfalls with CRSP could simulate bouncing of falling rocks. By
analyzing moving paths, velocity, and bounce height of falling rocks,
we could effectively locate impact points of falling rocks on a slope.
Such analysis can be served as a reference for future disaster
prevention and control.
Abstract: Many medical devices are driven by motor pumps. Some researchers reported that the vibration mainly affected medical devices using a motor pump. The purpose of this study was to examine the effect of stiffness and damping coefficient in a 3-dimensional (3D) model of a motor pump and spring. In the present paper, experimental and mathematical tests for the moments of inertia of the 3D model and the material properties were investigated by an INSTRON machine. The response surfaces could be generated by using 3D multi-body analysis and the design of experiment method. It showed that differences in contours of the response surface were clearly found for the particular area. Displacement of the center of the motor pump was decreased at K≈2000 N/M, C≈12.5 N-sec/M. However, the frequency was increased at K≈2000 N/M, C≈15 N-sec/M. In this study, this study suggested experimental technique for vibration reduction for a motor pump in medical device. The combined method suggested in this study will greatly contribute to design of medical devices concerning vibration and noise intervention.
Abstract: The present paper considers the steady free
convection boundary layer flow of a viscoelastics fluid with constant
temperature in the presence of heat generation. The boundary layer
equations are an order higher than those for the Newtonian (viscous)
fluid and the adherence boundary conditions are insufficient to
determine the solution of these equations completely. The governing
boundary layer equations are first transformed into non-dimensional
form by using special dimensionless group. Computations are
performed numerically by using Keller-box method by augmenting
an extra boundary condition at infinity and the results are displayed
graphically to illustrate the influence of viscoelastic K, heat
generation γ , and Prandtl Number, Pr parameters on the velocity
and temperature profiles. The results of the surface shear stress in
terms of the local skin friction and the surface rate of heat transfer in
terms of the local Nusselt number for a selection of the heat
generation parameterγ (=0.0, 0.2, 0.5, 0.8, 1.0) are obtained and
presented in both tabular and graphical formats. Without effect of the
internal heat generation inside the fluid domain for which we take
γ = 0.0, the present numerical results show an excellent agreement
with previous publication.
Abstract: We present a white LED-based optical wireless
communication systems for indoor ubiquitous sensor networks. Each
sensor node could access to the server through the PLC (Power Line
Communication)-Ethernet interface. The proposed system offers a
full-duplex wireless link by using different wavelengths to reduce the
inter-symbol interference between uplink and downlink. Through the
1-to-n optical wireless sensor network and PLC modem, the mobile
terminals send a temperature data to server. The data transmission
speed and distance are 115.2kbps and about 60cm, respectively.
Abstract: In this study, we used a two-stage process and
potassium hydroxide (KOH) to transform waste biomass (rice straw)
into activated carbon and then evaluated the adsorption capacity of the
waste for removing carbofuran from an aqueous solution. Activated
carbon was fast and effective for the removal of carbofuran because of
its high surface area. The native and carbofuran-loaded adsorbents
were characterized by elemental analysis. Different adsorption
parameters, such as the initial carbofuran concentration, contact time,
temperature and pH for carbofuran adsorption, were studied using a
batch system. This study demonstrates that rice straw can be very
effective in the adsorption of carbofuran from bodies of water.
Abstract: Arthrobacter viscosus biomass was used for Cr(VI)
biosorption. The effect of pH on Cr(VI) reduction and removal from
aqueous solution was studied in the range of 1-4. The Cr(VI) removal
involves both redox reaction and adsorption of metal ions on biomass
surface. The removal rate of Cr(VI) was enhanced by very acid
conditions, while higher solution pH values favored the removal of
total chromium. The best removal efficiency and uptake were
reached at pH 4, 72.5 % and 12.6 mgCr/gbiomass, respectively.
Abstract: This current research focused on development of degradable starch based packaging film with enhanced mechanical properties. A series of low density polyethylene (LDPE)/tapioca starch compounds with various tapioca starch contents were prepared by twin screw extrusion with the addition of maleic anhydride grafted polyethylene as compatibilizer. Palm cooking oil was used as processing aid to ease the blown film process, thus, degradable film can be processed via conventional blown film machine. Studies on their characteristics, mechanical properties and biodegradation were carried out by Fourier Transform Infrared (FTIR) spectroscopy and optical properties, tensile test and exposure to fungi environment respectively. The presence of high starch contents had an adverse effect on the tensile properties of LDPE/tapioca starch blends. However, the addition of compatibilizer to the blends improved the interfacial adhesion between the two materials, hence, improved the tensile properties of the films. High content of starch amount also was found to increase the rate of biodegradability of LDPE/tapioca starch films. It can be proved by exposure of the film to fungi environment. A growth of microbes colony can be seen on the surface of LDPE/tapioca starch film indicates that the granular starch present on the surface of the polymer film is attacked by microorganisms, until most of it is assimilated as a carbon source.
Abstract: Carbon nanotubes (CNTs) are attractive because of
their excellent chemical durability mechanical strength and electrical
properties. Therefore there is interest in CNTs for not only electrical
and mechanical application, but also biological and medical
application.
In this study, the dispersion power of surfactant-treated multiwalled
carbon nanotubes (MWCNTs) and their effect on the antibacterial
activity were examined. Surfactant was used sodium
dodecyl-benzenesulfonate (SDBS). UV-vis absorbance and
transmission electron microscopy(TEM) were used to characterize the
dispersion of MWCNTs in the aqueous phase, showing that the
surfactant molecules had been adsorbed onto the MWCNTs surface.
The surfactant-treated MWCNTs exhibited antimicrobial activities
to streptococcus mutans. The optical density growth curves and viable
cell number determined by the plating method suggested that the
antimicrobial activity of surfactant-treated MWCNTs was both
concentration and treatment time-dependent.
Abstract: Group work, projects and discussions are important
components of teacher education courses whether they are face-toface,
blended or exclusively online formats. This paper examines the varieties of tasks and challenges with this learning format in a face to
face class teacher education class providing specific examples of both
failure and success from both the student and instructor perspective.
The discussion begins with a brief history of collaborative and cooperative learning, moves to an exploration of the promised
benefits and then takes a look at some of the challenges which can
arise specifically from the use of new technologies. The discussion concludes with guidelines and specific suggestions.
Abstract: CFD simulations are carried out in arterial stenoses
with 48 % areal occlusion. Non-newtonian fluid model is selected for
the blood flow as the same problem has been solved before with
Newtonian fluid model. Studies on flow resistance with the presence
of surface irregularities are carried out. Investigations are also
performed on the pressure drop at various Reynolds numbers. The
present study revealed that the pressure drop across a stenosed artery
is practically unaffected by surface irregularities at low Reynolds
numbers, while flow features are observed and discussed at higher
Reynolds numbers.
Abstract: This paper presents a set of guidelines for the design
of multi-user awareness systems. In a first step, general requirements
for team awareness systems are analyzed. In the second part of the
paper, the identified requirements are aggregated and transformed
into concrete design guidelines for the development of team
awareness systems.
Abstract: In this work, we examine fluid mixing in a full three-stream mixing channel with longitudinal vortex generators (LVGs) built on the channel bottom by numerical simulation and experiment. The effects of the asymmetrical arrangement and the attack angle of the LVGs on fluid mixing are investigated. The results show that the micromixer with LVGs at a small asymmetry index (defined by the ratio of the distance from the center plane of the gap between the winglets to the center plane of the main channel to the width of the main channel) is superior to the micromixer with symmetric LVGs and that with LVGs at a large asymmetry index. The micromixer using five mixing modules of the LVGs with an attack angle between 16.5 degrees and 22.5 degrees can achieve excellent mixing over a wide range of Reynolds numbers. Here, we call a section of channel with two pairs of staggered asymmetrical LVGs a mixing module. Besides, the micromixer with LVGs at a small attack angle is more efficient than that with a larger attack angle when pressure losses are taken into account.
Abstract: Context awareness is a capability whereby mobile
computing devices can sense their physical environment and adapt
their behavior accordingly. The term context-awareness, in
ubiquitous computing, was introduced by Schilit in 1994 and has
become one of the most exciting concepts in early 21st-century
computing, fueled by recent developments in pervasive computing
(i.e. mobile and ubiquitous computing). These include computing
devices worn by users, embedded devices, smart appliances, sensors
surrounding users and a variety of wireless networking technologies.
Context-aware applications use context information to adapt
interfaces, tailor the set of application-relevant data, increase the
precision of information retrieval, discover services, make the user
interaction implicit, or build smart environments. For example: A
context aware mobile phone will know that the user is currently in a
meeting room, and reject any unimportant calls. One of the major
challenges in providing users with context-aware services lies in
continuously monitoring their contexts based on numerous sensors
connected to the context aware system through wireless
communication. A number of context aware frameworks based on
sensors have been proposed, but many of them have neglected the
fact that monitoring with sensors imposes heavy workloads on
ubiquitous devices with limited computing power and battery. In this
paper, we present CALEEF, a lightweight and energy efficient
context aware framework for resource limited ubiquitous devices.
Abstract: A thin coating of hexamethyldisiloxane and subsequent O2-plasma treatment was performed on mirror-polished titanium in order to regulate the wide range of wettability including 106 and almost 0 degrees of contact angles. The adsorption behavior of
fibronectin and albumin in both individual and competitive mode,
and initial attachment of fibroblasts and osteoblasts were investigated.
Individually, fibronectin adsorption showed a biphasic inclination, whereas albumin showed greater adsorption to hydrophobic surfaces.
In competitive mode, in solution containing both fibronectin and albumin, fibronectin showed greater adsorption on hydrophilic
surfaces, whereas Alb predominantly adsorbed on hydrophobic
surfaces. Initial attachment of both cells increased with increase in
surface wettability, in particular, on super-hydrophilic surface, which
correlated well with fibronectin adsorption in competitive mode.
These results suggest that a cold plasma-surface modification enabled
to regulate the surface wettability, and fibronectin adsorption may be
responsible for increasing cell adhesion on hydrophilic surfaces in a
body fluid
Abstract: Finger spelling is an art of communicating by signs
made with fingers, and has been introduced into sign language to serve
as a bridge between the sign language and the verbal language.
Previous approaches to finger spelling recognition are classified into
two categories: glove-based and vision-based approaches. The
glove-based approach is simpler and more accurate recognizing work
of hand posture than vision-based, yet the interfaces require the user to
wear a cumbersome and carry a load of cables that connected the
device to a computer. In contrast, the vision-based approaches provide
an attractive alternative to the cumbersome interface, and promise
more natural and unobtrusive human-computer interaction. The
vision-based approaches generally consist of two steps: hand
extraction and recognition, and two steps are processed independently.
This paper proposes real-time vision-based Korean finger spelling
recognition system by integrating hand extraction into recognition.
First, we tentatively detect a hand region using CAMShift algorithm.
Then fill factor and aspect ratio estimated by width and height
estimated by CAMShift are used to choose candidate from database,
which can reduce the number of matching in recognition step. To
recognize the finger spelling, we use DTW(dynamic time warping)
based on modified chain codes, to be robust to scale and orientation
variations. In this procedure, since accurate hand regions, without
holes and noises, should be extracted to improve the precision, we use
graph cuts algorithm that globally minimize the energy function
elegantly expressed by Markov random fields (MRFs). In the
experiments, the computational times are less than 130ms, and the
times are not related to the number of templates of finger spellings in
database, as candidate templates are selected in extraction step.
Abstract: This paper focuses on a technique for identifying the geological boundary of the ground strata in front of a tunnel excavation site using the first order adjoint method based on the optimal control theory. The geological boundary is defined as the boundary which is different layers of elastic modulus. At tunnel excavations, it is important to presume the ground situation ahead of the cutting face beforehand. Excavating into weak strata or fault fracture zones may cause extension of the construction work and human suffering. A theory for determining the geological boundary of the ground in a numerical manner is investigated, employing excavating blasts and its vibration waves as the observation references. According to the optimal control theory, the performance function described by the square sum of the residuals between computed and observed velocities is minimized. The boundary layer is determined by minimizing the performance function. The elastic analysis governed by the Navier equation is carried out, assuming the ground as an elastic body with linear viscous damping. To identify the boundary, the gradient of the performance function with respect to the geological boundary can be calculated using the adjoint equation. The weighed gradient method is effectively applied to the minimization algorithm. To solve the governing and adjoint equations, the Galerkin finite element method and the average acceleration method are employed for the spatial and temporal discretizations, respectively. Based on the method presented in this paper, the different boundary of three strata can be identified. For the numerical studies, the Suemune tunnel excavation site is employed. At first, the blasting force is identified in order to perform the accuracy improvement of analysis. We identify the geological boundary after the estimation of blasting force. With this identification procedure, the numerical analysis results which almost correspond with the observation data were provided.
Abstract: The continued growth of the cities is causing an
increase of the amount of surface to illuminate. However, this rise
into lighting brings some unintended consequences such as increased
of energy consumption or the light pollution. To make these effects
less intrusive as possible some councils have chosen to perform a
part-night lighting in some areas. Nonetheless, this kind of shutdown
may cause serious problems which we intend to highlight in this
paper.
Abstract: Typically thermal power plants are located near to
surface coal mines that produce huge amount of fly ash as a waste
byproduct. Disposal of fly ash causes significant economic and
environmental problems. Now-a-days, research is going on for bulk
utilization of fly ash. In order to increase its percentage utilization, an
investigation was carried out to evaluate its potential for haul road
construction. This paper presents the laboratory California bearing
ratio (CBR) tests and evaluates the effect of lime on CBR behavior of
fly ash - mine overburden mixes. Tests were performed with different
percentages of lime (2%, 3%, 6%, and 9%). The results show that the
increase in bearing ratio of fly ash-overburden mixes was achieved
by lime treatment. Scanning electron microscopy (SEM) analyses
were conducted on 28 days cured specimens. The SEM study showed
that the bearing ratio development is related to the microstructural
development.
Abstract: In this paper, we propose an improved 3D star skeleton
technique, which is a suitable skeletonization for human posture representation
and reflects the 3D information of human posture.
Moreover, the proposed technique is simple and then can be performed
in real-time. The existing skeleton construction techniques, such as
distance transformation, Voronoi diagram, and thinning, focus on the
precision of skeleton information. Therefore, those techniques are not
applicable to real-time posture recognition since they are computationally
expensive and highly susceptible to noise of boundary. Although
a 2D star skeleton was proposed to complement these problems,
it also has some limitations to describe the 3D information of the
posture. To represent human posture effectively, the constructed skeleton
should consider the 3D information of posture. The proposed 3D
star skeleton contains 3D data of human, and focuses on human action
and posture recognition. Our 3D star skeleton uses the 8 projection
maps which have 2D silhouette information and depth data of human
surface. And the extremal points can be extracted as the features of 3D
star skeleton, without searching whole boundary of object. Therefore,
on execution time, our 3D star skeleton is faster than the “greedy" 3D
star skeleton using the whole boundary points on the surface. Moreover,
our method can offer more accurate skeleton of posture than the
existing star skeleton since the 3D data for the object is concerned.
Additionally, we make a codebook, a collection of representative 3D
star skeletons about 7 postures, to recognize what posture of constructed
skeleton is.