bluuebunny/crossref_metadata_2025 huggingface dataset:
An adaptive output feedback motion tracking controller for robot manipulators: Uniform global asymptotic stability and experimentation
Authors: Yarza Antonio , Santibanez Victor , Moreno-Valenzuela Javier
Published: October 2013

This paper deals with two important practical problems in motion control of robot manipulators: the measurement of joint velocities, which often results in noisy signals, and the uncertainty of parameters of the dynamic model. Adaptive output feedback controllers have been proposed in the literature in order to deal with these problems. In this paper, we prove for the first time that Uniform Global Asymptotic Stability (UGAS) can be obtained from an adaptive output feedback tracking controller, if the reference trajectory is selected in such a way that the regression matrix is persistently exciting. The new scheme has been experimentally implemented with the aim of confirming the theoretical results.
A fuzzy approach to option pricing in a Levy process setting
Authors: Nowak Piotr , Romaniuk Maciej
Published: October 2013

In this paper the problem of European option valuation in a Levy process setting is analysed. In our model the underlying asset follows a geometric Levy process. The jump part of the log-price process, which is a linear combination of Poisson processes, describes upward and downward jumps in price. The proposed pricing method is based on stochastic analysis and the theory of fuzzy sets.We assume that some parameters of the financial instrument cannot be precisely described and therefore they are introduced to the model as fuzzy numbers. Application of fuzzy arithmetic enables us to consider various sources of uncertainty, not only the stochastic one. To obtain the European call option pricing formula we use the minimal entropy martingale measure and Levy characteristics.
Spectral Mapping Using Kernel Principal Components Regression for Voice Conversion
Authors: Song Peng , Zhao Li , Bao Yongqiang
Published: October 2013

The Gaussian mixture model (GMM) method is popular and efficient for voice conversion (VC), but it is often subject to overfitting. In this paper, the principal component regression (PCR) method is adopted for the spectral mapping between source speech and target speech, and the numbers of principal components are adjusted properly to prevent the overfitting. Then, in order to better model the nonlinear relationships between the source speech and target speech, the kernel principal component regression (KPCR) method is also proposed. Moreover, a KPCR combined with GMM method is further proposed to improve the accuracy of conversion. In addition, the discontinuity and oversmoothing problems of the traditional GMM method are also addressed. On the one hand, in order to solve the discontinuity problem, the adaptive median filter is adopted to smooth the posterior probabilities. On the other hand, the two mixture components with higher posterior probabilities for each frame are chosen for VC to reduce the oversmoothing problem. Finally, the objective and subjective experiments are carried out, and the results demonstrate that the proposed approach shows greatly better performance than the GMM method. In the objective tests, the proposed method shows lower cepstral distances and higher identification rates than the GMM method. While in the subjective tests, the proposed method obtains higher scores of preference and perceptual quality.
Matched-field Source Localization with a Mobile Short Horizontal Linear Array in Offshore Shallow Water
Authors: Zhao Dexin , Huang Zhiping , Su Shaojing , Li Ting
Published: October 2013

Passive source localization in shallow water has always been an important and challenging problem. Implementing scientific research, surveying, and monitoring using a short, less than ten meter long, horizontal linear array has received considerable attention in the recent years. The short array can be conveniently placed on autonomous underwater vehicles and deployed for adaptive spatial sampling. However, it is usually difficult to obtain a sufficient spatial gain for localizing long-range sources due to its limited physical size. To address this problem, a localization approach is proposed which is based on matched-field processing of the likelihood of the passive source localization in shallow water, as well as inter-position processing for the improved localization performance and the enhanced stability of the estimation process. The ability of the proposed approach is examined through the two-dimensional synthetic test cases which involves ocean environmental mismatch and position errors of the short array. The presented results illustrate the localization performance for various source locations at different signal- to-noise ratios and demonstrate the build up over time of the positional parameters of the estimated source as the short array moves at a low speed along a straight line at a certain depth.
Ultrasonic Noise Sources in a Work Environment
Authors: Smagowska Bożena
Published: October 2013

The use of ultrasonic energy has created versatile possibilities of their applications in many areas of life, especially in hydro location and underwater telecommunications, industry and medicine. The consequence of a widespread use of high intensity ultrasonics in technology is the increased number of people who are exposed to such ultrasonic noise. Therefore it is important to determine the types of machines and other devices that are responsible for the emission of ultrasonic noise (10-40 kHz of central frequencies of one-third octave bands) as harmful and annoying hazard in the work environment. This paper presents ultrasonic noise sources frequently used in industry and preventive measures reducing the exposure to ultrasonic noise. Two types of ultrasonic noise sources have been distinguished: machines and other devices used to carry out or improve production processes, the so-called technological sources and sources in which ultrasonic noise exists as a non-intentional result of operation of many machines and systems, the so-called non-technological sources of ultrasonic noise. The emission of SPL has been determined for each groups of devices based on own measurement results.
Method of Testing of Sound Absorption Properties of Materials Intended for Ultrasonic Noise Protection
Authors: Pleban Dariusz
Published: October 2013

Efficient ultrasonic noise reduction by using enclosures requires the knowledge of absorbing properties of materials in the frequency range above 4 kHz. However, standardized methods enable determination of absorption coefficients of materials in the frequency range up to 4 kHz. For this reason, it is proposed to carry out measurements of the sound absorption properties of materials in the free field by means of a tone-burst technique in the frequency range from 4 kHz to 40 kHz at angles of incidence varying from 0° to 60°. The absorption coefficient of a material is calculated from the reflection coefficient obtained by reflecting a tone-burst from both a perfectly reflecting panel and a combination of this panel and the sample of the tested material. The tests results show that mineral wool and polyurethane open-cell foam possess very good absorbing properties in this frequency range.
Creating Dynamic Maps of Noise Threat Using PL-Grid Infrastructure
Authors: Szczodrak Maciej , Kotus Józef , Kostek Bożena , Czyżewski Andrzej
Published: October 2013

The paper presents functionality and operation results of a system for creating dynamic maps of acoustic noise employing the PL-Grid infrastructure extended with a distributed sensor network. The work presented provides a demonstration of the services being prepared within the PLGrid Plus project for measuring, modeling and rendering data related to noise level distribution in city agglomerations. Specific computational environments, the so-called domain grids, are developed in the mentioned project. For particular domain grids, specialized IT solutions are prepared, i.e. software implementation and hardware (infrastructure adaptation), dedicated for particular researcher groups demands, including acoustics (the domain grid “Acoustics”). The infrastructure and the software developed can be utilized mainly for research and education purposes, however it can also help in urban planning. The engineered software is intended for creating maps of noise threat for road, railways and industrial sources. Integration of the software services with the distributed sensor network enables automatic updating noise maps for a specific time period. The unique feature of the developed software is a possibility of evaluating auditory effects which are caused by the exposure to excessive noise. The estimation of auditory effects is based on calculated noise levels in a given exposure period. The outcomes of this research study are presented in a form of the cumulative noise dose and the characteristics of the temporary threshold shift.
Assessment of Ultrasonic Noise Hazard in Workplaces Environment
Authors: Śliwiński Antoni
Published: October 2013

The hazard assessment of ultrasonic noise impact on human body at workplaces presents an open problem; it is not satisfactorily solved comparing the fund of knowledge and standard regulations established for the case of audible noise. Some research carried on in the Central Institute of Labour Protection - National Research Institute, Poland, are essential for elaboration reliable procedures for the assessment of ultrasonic noise hazard and they have to bring to modernization and creation the corresponding standards in this field. In the presentation, some problems related to measurement procedures applied as well as to the interpretation of results essential for hazard assessment of ultrasonic noise impact on human body will be considered; in particular such cases where some procedures elaborated for audible noise assessment are being transferred to apply in the ultrasonic range without taking fully into account some specific aspects of the high frequency components of the noise.
A Perception-Based Method for the Noise Control of Construction Machines
Authors: Carletti Eleonora
Published: October 2013

During operation, construction machines generate high noise levels which can adversely affect the health and the job performance of operators. The noise control techniques currently applied to reduce the noise transmitted into the operator cab are all based on the decrease of the sound pressure level. Merely reducing this noise parameter may be suitable for the compliance with the legislative requirements but, unfortunately, it is not sufficient to improve the subjective human response to noise. The absolute necessity to guarantee comfortable and safe conditions for workers, requires a change of perspective and the identification of different noise control criteria able to combine the reduction of noise levels with that of psychophysical descriptors representing those noise attributes related to the subjective acoustical discomfort.

This paper presents the results of a study concerning the “customization” of a methodology based on Sound Quality for the noise control of construction machines. The purpose is to define new hearing-related criteria for the noise control able to guarantee not only reduced noise levels at the operator position but also a reduced annoyance perception.
Investigation of Ultrasonic Emulsifying Processes of a Linseed Oil and Water Mixture
Authors: Skumiel Andrzej , Józefczak Arkadiusz , Heller Krzysztof , Hornowski Tomasz , Wielgusz Katarzyna
Published: October 2013

Ultrasonic emulsifying processes of immiscible liquids can be used to obtain stable emulsions. The authors used an ultrasonic sandwich head with an energy concentrator to obtain a suitable value of the energy density necessary for the emerge of ultrasonic cavitation. Two piezoelectric ring (Dext = 50 mm) transducers of Pz-26 type produced by FERROPERM were used to design the ultrasonic sandwich head. The frequency of the ultrasonic wave was 18.4 kHz and the excitation time of the ultrasonic transducer exiting 5 minutes. Visible bubbles during the generation of ultrasonic waves appeared in the mixture after exceeding the cavitation threshold. The authors determined also the cavitation threshold by measuring the electrical voltage conducted to the transducers. To receive long-lasting emulsion, the electrical voltage attained 300 Vpeak. The dispersion dependence on the emulsifying time was determined. The emulsion of linseed oil and water was stable through some months without surfactants.
Source Width of Frontal Phantom Sources: Perception, Measurement, and Modeling
Authors: Frank Matthias
Published: October 2013

Phantom sources are known to be perceived similar to real sound sources but with some differences. One of the differences is an increase of the perceived source width. This article discusses the perception, measurement, and modeling of source width for frontal phantom sources with different symmetrical arrangements of up to three active loudspeakers. The perceived source width is evaluated on the basis of a listening test. The test results are compared to technical measures that are applied in room acoustics: the inter-aural cross correlation coefficient (IACC) and the lateral energy fraction (LF). Adaptation of the latter measure makes it possible to predict the results by considering simultaneous sound incidence. Finally, a simple model is presented for the prediction of the perceived source width that does not require acoustic measurements as it is solely based on the loudspeaker directions and gains.
Ultrasound Transmission Tomography Imaging of Structure of Breast Elastography Phantom Compared to US, CT and MRI
Authors: Opieliński Krzysztof J. , Pruchnicki Piotr , Gudra Tadeusz , Podgórski Przemysław , Kraśnicki Tomasz , Kurcz Jacek , Sąsiadek Marek
Published: October 2013

The paper presents an analysis of the results of ultrasound transmission tomography (UTT) imaging of the internal structure of a breast elastography phantom used for biopsy training, and compares them with the results of CT, MRI and, conventional US imaging; the results of the phantom examination were the basis for the analysis of UTT method resolution. The obtained UTT, CT and MRI images of the CIRS Model 059 breast phantom structure show comparable (in the context of size and location) heterogeneities inside it. The UTT image of distribution of the ultrasound velocity clearly demonstrates continuous changes of density. The UTT image of derivative of attenuation coefficient in relation to frequency is better for visualising sharp edges, and the UTT image of the distribution of attenuation coefficient visualises continuous and stepped changes in an indirect way. The inclusions visualized by CT have sharply delineated edges but are hardly distinguishable from the phantom gel background even with increased image contrast. MRI images of the studied phantom relatively clearly show inclusions in the structure. Ultrasonography images do not show any diversification of the structure of the phantom. The obtained examination results indicate that, if the scanning process is accelerated, ultrasound transmission tomography method can be successfully used to detect and diagnose early breast malignant lesions. Ultrasonic transmission tomography imaging can be applied in medicine for diagnostic examination of women’s breasts and similarly for X-ray computed tomography, while eliminating the need to expose patients to the harmful ionising radiation.
Pitch Processing of Speech: Comparison of Psychoacoustic and Electrophysiological Data
Authors: Wrzosek Małgorzata , Maculewicz Justyna , Hafke-Dys Honorata , Nowik Agnieszka , Preis Anna , Kroliczak Grzegorz
Published: October 2013

The present study consisted of two experiments. The goal of the first experiment was to establish the just noticeable differences for the fundamental frequency of the vowel /u/ by using the 2AFC method. We obtained the threshold value for 27 cents. This value is larger than the motor reaction values which had been observed in previous experiments (e.g. 9 or 19 cents). The second experiment was intended to provide neurophysiological confirmation of the detection of shifts in a frequency, using event-related potentials (ERPs). We concentrated on the mismatch negativity (MMN) - the component elicited by the change in the pattern of stimuli. Its occurrence is correlated with the discrimination threshold. In our study, MMN was observed for changes greater than 27 cents - shifts of ±50 and 100 cents (effect size - Cohen’s d = 2.259). MMN did not appear for changes of ±10 and 20 cents. The results showed that the values for which motor responses can be observed are indeed lower than those for perceptual thresholds.
Acoustic Absorption of Mortar Composites with Waste Material
Authors: Stumpf González Marco Aurélio , Flach Fernanda , Reschke Pires Josiane , Piva Kulakowski Marlova
Published: October 2013

This paper presents an investigation about acoustic absorption of mortars with partial replacement of sand by waste (plywood formwork, rice husk, and thermoplastic shoe counters), examining different levels of replacement (0%, 5%, 10%, 25%, and 50%). The measurement of acoustic absorption was performed using a plane wave impedance tube with 100 mm diameter, using mortar samples of 20 mm, in frequency range 200-2000 Hz. Results demonstrated that some composite with waste presented noise reduction coefficient (NRC) above the reference mortar (NRC = 0.0343), such as a composite with 50% rice husk (NRC = 0.2757) and other with 50% of plywood waste (NRC = 0.2052). Since there is virtually no cost or difficulty to use these residuals, it may be concluded that it is a sustainable alternative to improve the acoustic comfort and reduce the impact of the waste on the environment.
A Clamped Bar Model for the Sompoton Vibrator
Authors: Wong Tee Hao , Dayou Jedol , Ngu M.C.D. , Chang Jackson H.W. , Liew Willey Y.H.
Published: October 2013

The sompoton is one of famous traditional musical instruments in Sabah. This instrument consists of several parts with the vibrator being the most important one. In this paper, the vibrator is modeled as a clamped bar with a uniformly distributed mass. By means of this model, the fundamental frequency is analyzed with the use of an equivalent single degree of freedom system (SDOF) and exact analysis. The vibrator is made of aluminum in different sizes and is excited using a constant air jet to obtain its fundamental resonance frequency. The fundamental frequency obtained from the experimental measurement is compared with the theoretical values calculated based on the equivalent SDOF and exact analysis theories. It is found that the exact analysis gives a closer value to the experimental results as compared to the SDOF system. Although both the experimental and theoretical results exhibit the same trend, they are different in magnitude. To overcome the differences in both theories, a correction factor is added to account for the production errors.
Practical Aspects Concerning Nonlinear Dynamic Analysis of Cable Structures
Authors: Lazar-Mand Ferencz
Published: October 2013

The paper is about some aspects concerning the nonlinear dynamic analysis of prestressed cable structures. A method for the assessment of the tangent stiffness matrix and of the nonlinear parameters is proposed. The methodology is similar to the one described by P. Krishna. The Newmark method is used to integrate the motion equation. In the final section of the paper a comparison between the output supplied by the software of the presented method is made, with constant stiffness matrix(linear) and with the non-linear matrix updated step by step (geometric non-linear). The elements used for comparison are the displacement and velocity response of a given pretensioned cable structure.
Estimation of the Statistical Distribution Used in Hydrology Using Kernel Functions
Authors: Trandafir Romică , Ciuiu Daniel , Drobot Radu
Published: October 2013

In this paper we will study the statistical distributions for the extreme discharges of the Danube River using kernel functions. We will also compare the results with those obtained using classical cumulative distribution functions (Pareto, Weibull, etc).
Influence of Granulometric Cement Characteristics on the Uniformity Degree
Authors: Mitu Corina , Radu Lidia
Published: October 2013

In industrial practice, the dimensional characterization of the polygranular materials can be done, experimentally and/or by calculation, on the basis of various types of granulometric distribution laws, of the different types of diameters, of the specific surface and of some indicators related to the granulometric uniformity. This paper aims at introducing a new indicator, called granulometric uniformity degree, defined on the basis of some informational statistics elements, and calculated in a unique way, different from any particular type of granulometric distribution. At the same time, a series of correlations between the granulometric uniformity degree and different characteristic diameters is pointed out, i.e. the specific surface of cements, characterized by the Rosin-Rammler-Sperling ganulometric distribution.
In Plane Cyclic Behavior of Masonry Walls Jacketed with Fiber Reinforced Mortar and Fiber Grids
Authors: Popa Viorel , Pascu Radu , Papurcu Andrei
Published: October 2013

Masonry buildings represent the most vulnerable part of the building stock to seismic action in Romania. The main goal of this experimental research program is to investigate the efficiency of several retrofitting solutions using fiber reinforced polymers. Research focused on the lateral strength and displacement capacity of the retrofitted specimens. The masonry walls were built using solid bricks. Glass or carbon fiber reinforced polymers (GFRP or CFRP) embedded in a fiber reinforced mortar layer were used for jacketing. Seven specimens having essentially 25cm width, 1,75m height and 2,10m length were tested in the experimental research program. These specimens were subjected to a constant vertical compressive stress of 1,2MPa. A quasi-static load protocol was considered for the horizontal loading. This paper presents the layout of the experimental research program and some preliminary results.
Seasonal Water Temperature Variability of Springs From Porous Sediments in Gryżynka Valley, Western Poland
Authors: Szczucińska Anna Maria , Wasielewski Hieronim
Published: October 2013

This paper discusses fluctuations in spring water temperature and its correlation to climate and aquifer characteristics. Data from nine springs in the Gryżynka River catchment (Polish Plain) were taken monthly (November 2005 to October 2010). The springs examined in this study are characterised by significant thermal inertia in contrast to air temperature, that is expressed in small temperature amplitudes that range from 1.3°C to 2.3°C. The average temperature of the springs is about 9°C. The research proved that observed groundwater temperature variations on the surface resulted mainly from atmospheric conditions, especially air temperature. The highest water temperatures (up to 10°C) were observed during late summer and early autumn, and the lowest temperature (7.7°C) was observed at the end of the winter period. The range of spring water temperature variability may reflect amount of water contribution from local water recharge in the spring vicinity.
Effect of the North Atlantic Oscillation on Ice Phenomena on Selected Lakes in Poland Over the Years 1961–2010
Authors: Wrzesiński Dariusz , Ptak Mariusz , Baczyńska Alicja
Published: October 2013

An analysis is presented of changes in the parameters of ice phenomena on selected Polish lakes over the years 1961-2010 against the background of variations in the intensity of the North Atlantic Oscillation. The following features were analysed: the start and end of ice phenomena and ice cover, their duration, and the stability of ice cover at observation sites of the Institute of Meteorology and Water Management on lakes located in various physical-geographic regions. Multi-year tendencies of change in the ice parameters under study were identified. The most statistically significant negative trends were observed for the ending dates of ice phenomena and their duration. Changes in the ice characteristics in the different NAODJFM stages were determined on the basis of their deviations: between years with high (> 1.7) and low (< -1.09) values of the winter NAO index, and from average values from the years 1961-2010. Changes in the intensity of the North Atlantic Oscillation affect all the parameters of ice phenomena except their starting dates. In a negative NAODJFM stage, ice phenomena and ice cover end later and last longer; also, the maximum thickness of ice cover is greater, its forms later and is more stable than in a positive stage and in average conditions
Initial Assessment of the Weather Research and Forecasting Model for Forecasting Bioclimatic Conditions During Breeze Circulation – Case Study of the Słowiński National Park
Authors: Czernecki Bartosz , Półrolniczak Marek
Published: October 2013

Land-sea interaction at the Polish Baltic Coast impacts the specific local climate conditions. Thermally driven circulation, observed mainly in the summer season, causes the advection of the cool sea air over land and influences the local atmospheric environment, including bioclimatic conditions. The aim of this paper is to present the evaluation of the WRF model for forecasting sensitive bioclimatic conditions on a selected day with sea breeze in the vicinity of the Łeba Sandbar (the Słowiński National Park). The results obtained from a numerical weather prediction model were post-processed to calculate the daily variability of two biothermal indices: the Effective Temperature (ET) and the Dry Cooling Power (H). To evaluate the thermal comfort of a person wearing typical clothes, the Michajlow’s, Petrovič and Kacvińsky’s scales were adopted. A detailed analysis performed for 31st July 2010 shows in most cases a satisfactory level of agreement between the simulated data and the in-situ measurements for nested domains with horizontal grid resolution less than 2 km. However, the simulation results tend to underestimate the thermal comfort, especially in the middle part of the Łeba Sandbar due to terrain data misrepresentations, which results in the overestimation of wind speed.
Influence of Relief and Land Cover on the Distribution of Values of the Land Surface Temperature in Upper Parsęta River Area
Authors: Kubiak Marta , Stach Alfred
Published: October 2013

The primary research problem presented in the article is verification of the thesis on the influence of relief and land cover type on the spatial variability of the land surface temperature (LST) distribution in the area including the river catchment area of upper Parsęta. The paper presents the use of thermal channels from two Landsat ETM+ scenes pictures, Corine Land Cover database from 2000 as well as the DTED-2 digital elevation model. Two ETM+ thermal bands processing algorithms were used for calculation of the land surface temperature: Qin et al. (2001) and Jiménez-Muňoz et al. (2003). Conducted statistical tests show significant differences of the land surface temperature values between particular land cover forms as well as types of relief. LST maps can be applied in topoclimatology eg. to detail and verify the in situ measurements.
Thermal and Humidity Conditions Over a Salient Land Form as Exemplified by a Coastal Sand Dune at the Łeba Sandbar in the Słowiński National Park
Authors: Kolendowicz Leszek , Forycka-Ławniczak Hanna
Published: October 2013

In July 2011, measurements were taken of selected meteorological elements in the central part of the Łeba Sandbar in the Słowiński National Park. On the basis of the results of measurements performed at five points located on a salient land form in close proximity to the seashore, a thermal and humidity characteristics of this form were determined for a twenty-four hour period. The results of measurements obtained from an automatic weather station located in an open area, near the measurement points on the coastal sand dune, were used as information on the atmospheric conditions predominant in the standard area (flat area covered by grass). The research analysis was performed for the entire measurement period and for days with radiational weather. The authors also determined the dependence between air temperature and humidity values observed over the analysed land form and the values of weather elements measured over the standard area.
Reducing Indoor Noise Levels Using People’s Perception on Greenery
Authors: Mediastika Christina E. , Binarti Floriberta
Published: October 2013

Employees working in cubicles of open-plan offices in Indonesia were studied in regard to their perception on the ability of indoor greenery to reduce noise levels. Sansevieria trifasciata and Scindapsus sp were used. Each was placed in the cubicle and noise levels were measured without plants, with Sansevieria, and with Scindapsus in place. The meters showed very insignificant difference. However, responses to surveys indicated a perception of lower noise in the presence of greenery. This seemed to be supported by prior knowledge and preconception and may be useful in creating a “quieter” indoor environment.
Sustainable Development in Estonian Mining
Authors: Šommet Julija
Published: October 2013

Importance and demand of high qualified mining material (carbonate rocks, oil shale) are growing nowadays. Deposits are widespread around the world. Is it possible to create the sustainability paradigm, that helps to manage quarries adequately to improve overall effectiveness of the company in total? This study focuses especially on the mining industry. This paper will introduce modern systems and a new one, that allows to make an indexation of the company by mining sustainability index and gradation of the company by its wellness; also brings several benefits for future sustainable development.
Solar Assisted Ground Source Heat Pump Performance in Nearly Zero Energy Building in Baltic Countries
Authors: Januševičius Karolis , Streckienė Giedrė
Published: October 2013

In near zero energy buildings (NZEB) built in Baltic countries, heat production systems meet the challenge of large share domestic hot water demand and high required heating capacity. Due to passive solar design, cooling demand in residential buildings also needs an assessment and solution. Heat pump systems are a widespread solution to reduce energy use. A combination of heat pump and solar thermal collectors helps to meet standard requirements and increases the share of renewable energy use in total energy balance of country. The presented paper describes a simulation study of solar assisted heat pump systems carried out in TRNSYS. The purpose of this simulation was to investigate how the performance of a solar assisted heat pump combination varies in near zero energy building. Results of three systems were compared to autonomous (independent) systems simulated performance. Different solar assisted heat pump design solutions with serial and parallel solar thermal collector connections to the heat pump loop were modelled and a passive cooling possibility was assessed. Simulations were performed for three Baltic countries: Lithuania, Latvia and Estonia.
Structural changes in data communication in wireless sensor networks
Authors: Silva Cabral Raquel , Aquino Andre , Frery Alejandro , Rosso Osvaldo , Ramírez Jaime
Published: October 2013

Wireless sensor networks are an important technology for making distributed autonomous measures in hostile or inaccessible environments. Among the challenges they pose, the way data travel among them is a relevant issue since their structure is quite dynamic. The operational topology of such devices can often be described by complex networks. In this work, we assess the variation of measures commonly employed in the complex networks literature applied to wireless sensor networks. Four data communication strategies were considered: geometric, random, small-world, and scale-free models, along with the shortest path length measure. The sensitivity of this measure was analyzed with respect to the following perturbations: insertion and removal of nodes in the geometric strategy; and insertion, removal and rewiring of links in the other models. The assessment was performed using the normalized Kullback-Leibler divergence and Hellinger distance quantifiers, both deriving from the Information Theory framework. The results reveal that the shortest path length is sensitive to perturbations.
Cardiovascular and Metabolic Comorbidities in Patients with Plaque-Type Psoriasis Never Treated with Systemic Antipsoriatic Drugs: a Case-Control Study
Authors: Damevska Katerina , Neloska Lence , Gocev Gjeorgji , Mihova Marija
Published: October 2013

Previous studies have shown a higher prevalence of cardiometabolic diseases among patients with psoriasis compared to non-psoriatics. However, little attention has been paid to the effects of systemic antipsoriatic drugs. The aim of this study was to investigate the association between psoriasis and these comorbidities, comparing untreated patients with psoriasis and population-based control non-psoriatic patients. A hospital-based case-control study included 122 patients with plaque-type psoriasis and 122 age- and gender-matched controls. Patients who ever received systemic antipsoriatic drugs were excluded. There were no significant differences between psoriatic patients and controls regarding the prevalence of hypertension (p=0.311), coronary heart disease (p=0.480), diabetes (p=0.641), myocardial infarction (p=0.71), stroke (2.4% vs. 2.4%, p=1.00) and metabolic syndrome (p=0.764). The prevalence of hypertriglyceridemia in patients with psoriasis and controls was 41.8% and 28.7%, respectively (OR 1.78, 95% CI 1.04-3.04, p=0.032). Furthermore, significant differences were observed in mean triglyceride levels (p=0.013). Smoking was significantly more often reported in psoriatic patients compared to controls. Patients with psoriasis also had a higher mean BMI (26.24, SD 4.42) compared with controls (24.73, SD 3.86), p=0.005. Psoriasis showed a statistically significant association with BMI obesity classification [χ2(4)=11.560, p=0.02]. The prevalence of cardiovascular and metabolic comorbidities was not significantly higher in patients with plaquetype psoriasis who were never treated with systemic antipsoriatic drugs, compared to population-based non-psoriatic controls. Our data suggest that systemic antipsoriatic drugs may play an important role in the development of these comorbidities. However, this study confirms that untreated psoriasis patients have three major modifiable increased cardiovascular risk factors, such as smoking, obesity and hypertriglyceridemia.
Langerhans Cell Histiocytosis: a Case Report
Authors: Paravina Mirjana , Jovanović Dragan , Stanojević Milenko , Nikolić Ljiljana
Published: October 2013

Langerhans cell histiocytosis is a disease which results from accumulation or proliferation of a clonal population of cells with the phenotype of Langerhans cells arrested at an early stage of activation that are functionally deficient. The etiology and pathogenesis of the disorder are still unknown. There are ongoing investigations to determine whether it is a reactive or a neoplastic disease. The fact is that neoplastic and reactive processes may have many clinical and pathological similarities. Some emphasize the role of “cytokine storm” in Langerhans cells. Further studies are necessary in all areas, from the etiology and pathogenesis to diagnosis and therapy. Langerhans cell histiocytosis primarily affects bones, but less commonly it may involve other organ systems, or present as a multisystem disease. The clinical course is variable, from benign forms with spontaneous resolution, to chronic disseminated forms with fatal outcome. This is a report of a 29-year-old man with Langerhans cell histiocytosis with an onset at the age of 8, which later progressed to a multisystem disease. Apart from lesions on the skin and exposed mucous membranes, the patient also presented with: diabetes insipidus, granuloma of the right femur and slight bulbar protrusion of the right eye. The patient experienced spontaneous pneumothorax on two occasions. The diagnosis of Langerhans cell histiocytosis was histologically confirmed using electron microscopy by presence of Birbeck granules in the histiocytes. A favorable therapeutic response was obtained after systemic corticosteroid therapy.
Multiple Reticulohistiocytomas in an 88-year-old Man: a Case Report
Authors: Gajić Branislava , Roš Tatjana , Arapović Andrijana , Vučković Nada , Fejsa Levakov Aleksandra
Published: October 2013

Solitary and multiple reticulohistiocytomas, often referred to as diffuse cutaneous reticulohistiocytosis, that are generally restricted to skin, must be differentiated from multicentric reticulohistiocytosis. Multicentric reticulohistiocytosis is a rare histiocytic proliferative disease affecting joints, skin and mucous membranes, while arthropathy usually precedes skin and mucosal involvement. Other organs may also be involved, and 20% of patients have an associated internal malignancy. Multicentric reticulohistiocytosis has been reported to be associated with autoimmune diseases and malignancies. We present an 88-year-old man, with a sudden eruption of asymptomatic, firm, skin to brown colored papules and nodules, 6 to 17 mm in diameter, localized on forehead, arms, legs, and buttocks. There were no symptoms of joint or other organ involvement. Clinical and dermoscopic characteristics pointed to reticulohystiocytomas. Multiple excision biopsies of different tumors were performed and histopathology reports confirmed the diagnosis. In the case presented, reticulohistiocytosis was limited to the skin, exhibiting multiple reticlohistiocytomas with typical clinical, dermoscopic and rather peculiar histopathology presentation. Apart from this, some histologic features were seen in early lesions of multicentric reticulohistiocytosis, such as multinuclear cells dissociating collagen fibers with pale eosinophilic and foamy cytoplasm. Besides surgical excisions, no other treatment options were done. Laboratory and other tests showed no presence of extracutaneous illness, and no autoimmune or paraneoplastic processes. At one year follow up, the remaining tumors were of the same size, but there were no recurrences at excision sites, no signs of disease progression or systemic involvement. Since diffuse cutaneous reticulohistiocytosis without arthropathy as well as isolated reticulohistiocytomas have been described, in some cases of multiple reticulohistiocytomas even without systemic symptoms and signs, multicentric reticulohistiocytosis should be considered with an appropriate follow up. In such cases, skin lesions have the same histological features as lesions in multicentric reticulohistiocytosis, but they are not associated with joint problems or neoplasms.
Life history of Kermes quercus (LINNAEUS) (Hemiptera: Kermesidae) in Poland
Authors: Podsiadło Elżbieta
Published: October 2013

This research complements the results of a study of the life cycle of Kermes quercus (L.) performed in Poland in 2008-2009. The latest observations were carried out in 2010 from the beginning of March until the end of November. They showed that K. quercus overwintered as 2nd-instar nymphs. These developed into adults at the beginning of May. Reproduction began at the beginning of June. The 1st-instar nymphs of the new generation appeared in mid-June. They then developed for about 5 months, after which they entered the winter diapause. All the observations, carried out in 2008-2010, showed that, under the climatic conditions of Poland, K. quercus is not a univoltine species. One generation develops over two years. In the first year it overwinters as 1st-instar nymphs and in the second year as 2nd-instar nymphs.
Accessions to the Afrotropical fauna of Tortricidae (Lepidoptera), 2
Authors: Razowski Józef
Published: October 2013

Eighteen species of Afrotropical Tortricidae are discussed, eleven of which are described as new: Plinthograptis iitae sp. n., Lobesia hecista sp. n., Teiteccopsis davisorum sp. n., Anthozela daressalami sp. n., Herpystis isolata sp. n., Fulcrifera horisma sp. n., Cydia zariae sp. n., Cydia ergoda sp. n., Microsarotis samaruana sp. n., Ioditis mokwae sp. n., Grapholita hymenosa sp. n.
Systematics and faunistics of Neotropical Grapholitini, 5: Phloerampha, Goditha and Ranapoaca (Lepidoptera: Tortricidae)
Authors: Razowski Józef , Becker Vitor O.
Published: October 2013

Three genera - Phloerampha, Goditha and Ranapoaca - are treated, and the following species are described as new: Phloerampha involuta sp. n., Goditha latebrata sp. n., G. plesia sp. n., G. prepocydia sp. n., Ranapoaca rostellaria sp. n., R. memata sp. n. and R. liota sp. n. Laspeyresia sporosema MEYRICK is transferred to Goditha.
Response of Health Personnel on Medical Waste At Upazilla Health Complexes under Dhaka Division in Bangladesh
Authors: Polan MAA , Nomann NA , Jan CM , Saito T , Zaki MM , Taleb A
Published: October 2013

This cross sectional study was conducted among health personnel working in 7 Upazilla Health Complexes and support staff without medical background but concerned with waste management. A total of six respondents (doctors, nurses and & support staff, 2 each) from each Upazilla with average bed occupancy >10/day and where there are > 10 health personnel in position were selected. The objective of this study was to assess the health personnel whether they can identify the waste in the Health Complexes. The present study interviewed 42 respondents of which one third each were doctors, nurses, and support staff. In response to a question on type of waste generated at the Health Complex, 19.0% said infectious waste, 16.7% said pharmaceutical waste, 21.4% said pathological & anatomical waste, 23.8% said sharp waste and 19.0% said pressurised container. From response about different medical wastes, it shows that respondents know better about hazards of sharp waste and liquid waste. However, about other types of wastes like infectious waste, pathological waste, pharmacological waste, chemical waste, heavy metal waste, pressurized container and highly infectious waste the level of knowledge is rather poor or had no knowledge. Further study should be conducted on the issue with larger sample size and greater logistic support to reveal more generalized picture of country situation.DOI: http://dx.doi.org/10.3329/bjdre.v3i1.16587 Bangladesh Journal of Dental Research & Education Vol.3(1) 2013: 1-5
Level of Knowledge and Causes of Dental Disease among the Students of Selected Secondary Schools in Dhaka City
Authors: Akhtar R , Khan MHA , Sharmin S , Sarwar G
Published: October 2013

To assess the level of knowledge and causes of dental disease among the urban school children a cross-sectional study was conducted in two secondary schools of Dhaka city. 20 students each of class 6, 7 & 8 from each school were randomly selected. List of the students was obtained from the teacher & from the list 20 were selected. Regarding the level of knowledge 54% were found to have average knowledge and 25.8% had good knowledge about causes of dental disease. People should be made more aware about the maintenance of oral hygiene for ensuring better oral health.DOI: http://dx.doi.org/10.3329/bjdre.v3i1.16589 Bangladesh Journal of Dental Research & Education Vol.3(1) 2013: 12-15
Views of teachers regarding effective clinical teaching and learning in dental education
Authors: Ansary JA , Ara I , Zayeed NA , Debnath S , Amin MS
Published: October 2013

This was a qualitative study conducted in one government and one private dental college selected purposively. Study population was final year clinical teachers of selected Dental Colleges. A total of 35 teachers (twenty from private dental college and fifteen from govt. dental college) participated in this study. An open ended questionnaire was developed for  in-depth interview of the teachers. Analysis of the teachers' responses revealed that their views were related to only three issues: (1) Organization of teaching experiences: Make objectives realistic and practical, feedback, (2) Clinical experiences related factors: Students active involvement, working with patient and their family/ attendant and (3) Supervisory factors: Knowledgeable faculty, positive attitude of teachers. Dental faculty involved in teaching activities should be encouraged to take formal training. Study recommended increasing time and patient availability in clinical setting for effective clinical learning and skill competency.DOI: http://dx.doi.org/10.3329/bjdre.v3i1.16592 Bangladesh Journal of Dental Research & Education Vol.3(1) 2013: 25-29
Amalgam and Composite Restoration in Posterior Teeth
Authors: Nomann NA , Polan MAA , Jan CM , Rashid F , Taleb A
Published: October 2013

Basically most of the dentists choose amalgam for posterior restorations and they think amalgam is safe and poses no health risk to the patient. They also think that amalgam is the best material for posterior restoration as it can bear more masticatory stress, low price, easy to manipulate and also easy to handle/ place into the cavity. Moreover, their perception regarding amalgam is also very positive such as it is durable, the percentage of cusp fracture is less, no shrinkage and it has no toxic/harmful effect for oral health and general health also. But now a days controversy arises about this type of thinking in many clinical researches. Furthermore, composite became very popular to the dentist because of esthetic, two types of bonding (mechanical & chemical), less sound tooth structure have to remove, no harmful effect like mercury of amalgam, marginal leakage is less, cusp fracture is less, secondary caries detection easier than amalgam by radiograph, composite takes good polish, etc. But composite resins also have some disadvantages. This article has been prepared to give a picture on merits, demerits and different aspects of comparison on amalgam and composite restorative materials after reviewing different articles and publications.DOI: http://dx.doi.org/10.3329/bjdre.v3i1.16593 Bangladesh Journal of Dental Research & Education Vol.3(1) 2013: 30-35
Negotiating a healthy body in old age: preventive home visits and biopolitics
Authors: Otto Lene
Published: October 2013

The study discussed in this article sheds light on how a specific publichealth policy, the preventive home visit (PHV) aimed at senior citizens, is implemented at the local level in Denmark. Empirically the article calls attention to what is actually going on in a preventive practice, based on participant observations, interviews and ten years#&8217; worth of visitation records. Theoretically, the article applies a Foucauldian biopolitical approach that understands the visits as an implementation of the active ageing scheme, as the notion of prevention is practised as a continuous process, which is utilised to train people#&8217;s gazes and sensitivity, and teach them to recognise ‘activity’ as closely linked to future well-being and longevity. An important finding is that the intervention is not normalising in a deterministic way but rather negotiable. Even though the home visitors represent a health regimen where activity is interpreted as bodily exercise, they try to avoid the tendency to prescribe for older people. Rather than prevention in the strict sense, it seems to be a health promotion strategy that encourages older people to articulate their needs. The meeting between the health visitor and the older person is characterised by conversations and negotiations about health, autonomy and bodily experiences.