bluuebunny/crossref_metadata_2025 huggingface dataset:
Epoch-incremental reinforcement learning algorithms
Authors: Zajdel Roman
Published: October 2013

In this article, a new class of the epoch-incremental reinforcement learning algorithm is proposed. In the incremental mode, the fundamental TD(0) or TD(λ) algorithm is performed and an environment model is created. In the epoch mode, on the basis of the environment model, the distances of past-active states to the terminal state are computed. These distances and the reinforcement terminal state signal are used to improve the agent policy.
Parametric logarithmic type image processing for contrast based auto-focus in extreme lighting conditions
Authors: Florea Corneliu , Florea Laura
Published: October 2013

While most of state-of-the-art image processing techniques were built under the so-called classical linear image processing, an alternative that presents superior behavior for specific applications comes in the form of Logarithmic Type Image Processing (LTIP). This refers to mathematical models constructed for the representation and processing of gray tones images. In this paper we describe a general mathematical framework that allows extensions of these models by various means while preserving their mathematical properties. We propose a parametric extension of LTIP models and discuss its similarities with the human visual system. The usability of the proposed extension model is verified for an application of contrast based auto-focus in extreme lighting conditions. The closing property of the named models facilitates superior behavior when compared with state-of-the-art methods.
Pipelined language model construction for Polish speech recognition
Authors: Sas Jerzy , Żołnierek Andrzej
Published: October 2013

The aim of works described in this article is to elaborate and experimentally evaluate a consistent method of Language Model (LM) construction for the sake of Polish speech recognition. In the proposed method we tried to take into account the features and specific problems experienced in practical applications of speech recognition in the Polish language, reach inflection, a loose word order and the tendency for short word deletion. The LM is created in five stages. Each successive stage takes the model prepared at the previous stage and modifies or extends it so as to improve its properties. At the first stage, typical methods of LM smoothing are used to create the initial model. Four most frequently used methods of LM construction are here. At the second stage the model is extended in order to take into account words indirectly co-occurring in the corpus. At the next stage, LM modifications are aimed at reduction of short word deletion errors, which occur frequently in Polish speech recognition. The fourth stage extends the model by insertion of words that were not observed in the corpus. Finally the model is modified so as to assure highly accurate recognition of very important utterances. The performance of the methods applied is tested in four language domains.
A modified convolution and product theorem for the linear canonical transform derived by representation transformation in quantum mechanics
Authors: Goel Navdeep , Singh Kulbir
Published: October 2013

The Linear Canonical Transform (LCT) is a four parameter class of integral transform which plays an important role in many fields of signal processing. Well-known transforms such as the Fourier Transform (FT), the FRactional Fourier Transform (FRFT), and the FreSnel Transform (FST) can be seen as special cases of the linear canonical transform. Many properties of the LCT are currently known but the extension of FRFTs and FTs still needs more attention. This paper presents a modified convolution and product theorem in the LCT domain derived by a representation transformation in quantum mechanics, which seems a convenient and concise method. It is compared with the existing convolution theorem for the LCT and is found to be a better and befitting proposition. Further, an application of filtering is presented by using the derived results.
Efficient Phantom Source Widening
Authors: Zotter Franz , Frank Matthias
Published: October 2013

We present a highly efficient filter structure to create power-complementary filter pairs for phantom source widening. It either introduces frequency-dependent phase or amplitude differences in a pair of loudspeaker signals. We evaluate how the perceptual effect is influenced by off-center listening positions in a standard ±30° loudspeaker setup. The evaluation of the phantom source widening effect is based on measurements of the inter-aural cross-correlation coefficient (IACC), which is justified by its pronounced correlation to the perceived phantom source width in prior listening test results.
Evaluation of Decay Times from Noisy Room Responses with Pure-Tone Excitation
Authors: Meissner Mirosław
Published: October 2013

Reverberant responses are widely used to characterize acoustic properties of rooms, such as the early decay time (EDT) and the reverberation times T20 and T30. However, in real conditions a sound decay is often deformed by background noise, thus a precise evaluation of decay times from noisy room responses is the main problem. In this paper this issue is examined by means of numerical method where the decay times are estimated from the decay function that has been determined by nonlinear polynomial regression from a pressure envelope obtained via the discrete Hilbert transform. In numerical experiment the room responses were obtained from simulations of a sound decay for two-room coupled system. Calculation results have shown that background noise slightly affects the evaluation of reverberation times T20 and T30 as long as the signal-to-noise ratio (SNR) is not smaller than about 25 and 35 dB, respectively. However, when the SNR is close to about 20 and 30 dB, high overestimation of these times may occur as a result of bending up of the decay curve during the late decay.
HRTF Adjustments with Audio Quality Assessments
Authors: Yao Shu-Nung , Chen Li Jen
Published: October 2013

There are an increasing number of binaural systems embedded with head-related transfer functions (HRTFs), so listeners can experience virtual environments via conventional stereo loudspeakers or head- phones. As HRTFs vary from person to person, it is difficult to select appropriated HRTFs from already existing databases for users. Once the HRTFs in a binaural audio device hardly match the real ones of the users, poor localization happens especially on the cone of confusion. The most accurate way to obtain personalized HRTFs might be doing practical measurements. It is, however, expensive and time consuming. Modifying non-individualized HRTFs may be an effort-saving way, though the modifications are always accompanied by undesired audio distortion. This paper proposes a flexible HRTF adjustment system for users to define their own HRTFs. Also, the system can keep sounds from suffering intolerable distortion based on an objective measurement tool for evaluating the quality of processed audio.
Acoustic Features of Filled Pauses in Polish Task-Oriented Dialogues
Authors: Karpiński Maciej
Published: October 2013

Filled pauses (FPs) have proved to be more than valuable cues to speech production processes and important units in discourse analysis. Some aspects of their form and occurrence patterns have been shown to be speaker- and language-specific. In the present study, basic acoustic properties of FPs in Polish task-oriented dialogues are explored. A set of FPs was extracted from a corpus of twenty task- oriented dialogues on the basis of available annotations. After initial scrutiny and selection, a subset of the signals underwent a series of pitch, formant frequency and voice quality analyses. A significant amount of variation found in the realisations of FPs justifies their potential application in speaker recognition systems. Regular monosegmental FPs were confirmed to show relatively stable basic acoustic parameters, which allows for their easy identification and measurements but it may result in less significant differences among the speakers.
Modal Parameters of Two Violins with Different Varnish Layers and Subjective Evaluation of Their Sound Quality
Authors: Skrodzka Ewa B. , Linde Bogumił B.J. , Krupa Antoni
Published: October 2013

Two violins were investigated. The only intentionally introduced difference between them was the type of varnish. One of the instruments was covered with a spirit varnish, the other was oil varnished. Experimental modal analysis was done for unvarnished/varnished violins and a questionnaire inquiry on the instrument’s sound quality was performed. The aim of both examinations was to find differences and similarities between the two instruments in the objective (modal parameters) and subjective domain (subjective evaluation of sound quality). In the modal analysis, three strongly radiating signature modes were taken into account. Varnishing did not change the sequence of mode shapes. Modal frequencies A0 and B(1+) were not changed by oil varnishing compared to the unvarnished condition. For the oil varnished instrument, the frequency of mode B(1+) was lower than that of the same mode of the spirit varnished instrument. Our two violins were not excellent instruments, but before varnishing they were practically identical. However, after varnishing it appeared that the oil-varnished violin was better than the spirit-varnished instrument. Therefore, it can be assumed with a fairly high probability that also in general, the oil-varnished violins sound somewhat better than initially identical spirit-varnished ones.
Ultrasonic Properties of Magnetic Nanoparticles with an Additional Biocompatible Dextrane Layer
Authors: Dąbek Leszek , Hornowski Tomasz , Józefczak Arkadiusz , Skumiel Andrzej
Published: October 2013

The temperature dependence of the particle size distribution (PSD) of the magnetic fluid with an additional biocompatible dextran layer was studied using a ultrasonic method. The measurements of the ultrasound velocity and attenuation were carried out as a function of the volume concentration of magnetite particles at temperatures ranging from 15°C to 40°C. In order to extract the PSD from ultrasonic measurements, the theoretical model of Vinogradov-Isakovich was used. The extraction of PSD from the ultrasonic data requires also the measurements the density and viscosity of the ferrofluid samples. The calculated PSD of the magnetic fluid with an additional biocompatible layer shows a greater thermal stability than that of a magnetic fluid with a single surfactant layer.
Technical Notes: Practical Concerns Associated with Single-Number Ratings in Measuring Sound Transmission Loss Properties of Partition Panels
Authors: Garg Naveen , Kumar Anil , Maji Sagar
Published: October 2013

The paper presents an extensive review investigating the practical aspects related to the use of single- number ratings used in describing the sound insulation performance of partition wall panels and practical complications encountered in precise measurements in extensive frequency range from 50 Hz to 5 kHz. SWOT analysis of various single number ratings is described. A laboratory investigation on a double wall partition panel combination revealed the significant dependence of STC rating on transmission loss at 125 Hz attributed to 8 dB rule. An investigation conducted on devising alternative spectrums of aircraft noise, traffic noise, vehicular horn noise and elevated metro train noise as an extension to ISO 717-1 Ctr for ascertaining the sound insulation properties of materials exclusively towards these noise sources revealed that the single-number rating Rw + Ctr calculated using ISO 717-1 Ctr gives the minimum sound insulation, when compared with Rw + Cx calculated using the alternative spectrums of aircraft noise, traffic noise, etc., which means that material provides a higher sound insulation to the other noise sources. It is also observed that spectrum adaptation term Cx calculated using the spectrum of noise sources having high sound pressure levels in lower frequencies decreases as compared to ISO 717-1 Ctr owing to significant dependence of Ctr at lower frequencies.
Ultrasonic Method for Monitoring Environmental Risks Associated with Precipitation
Authors: Gudra Tadeusz , Banasiak Dariusz , Herman Krzysztof , Opieliński Krzysztof
Published: October 2013

This paper presents a solution that utilises ultrasonic technology to allow monitoring snow layer thickness or water level based on measurement from air. It describes the principle of operation of a measurement device using three methods of compensating for changing external factors affecting appliance’s precision. Block diagram of the device is also provided. In order to verify the proposed solutions, the research team tested the device in laboratory and operating conditions. The results obtained this way make it possible to select a configuration of device operation depending on the required measurement precision and limitations associated with installing the system for actual operation.
Research Papers: Global Index of the Acoustic Quality of Classrooms
Authors: Radosz Jan
Published: October 2013

Acoustic quality of a classroom is a term proposed to describe acoustic properties that contribute to a subjective impression received by a human, such as speech intelligibility, external noise, or vocal effort. It is especially important in classrooms, where suitable conditions should be provided to convey verbal content to students, taking into account their age. The article presents a method for assessing the acoustic quality of classrooms based on a single number global index and taking into account a number of factors affecting the outcome of the assessment. Partial indices are presented and their weights are proposed based on an analysis of factors determining whether a room meets applicable acoustic requirements. Results of the assessment of the acoustic quality carried out with the use of the developed method in selected classrooms are also presented.
Method of Determining the Sound Absorbing Coefficient of Materials within the Frequency Range of 5 000–50 000 Hz in a Test Chamber of a Volume of about 2 m3
Authors: Mikulski Witold
Published: October 2013

Sound absorption coefficient is a commonly used parameter to characterize the acoustic properties of sound absorbing materials. It is defined within the frequency range of 100-5 000 Hz. In the industrial conditions, many appliances radiating acoustic energy of the frequency range of above 5000 Hz are used and at the same time it is known that a noise within the frequency range of 5 000-50 000 Hz can have a harmful effect on people,hence there is a need to define the coefficient in this frequency range. The article presents a proposal for a method of measurement of the sound absorption coefficient of materials in the frequency range from 5 000 Hz to 50 000 Hz. This method is a modification of the reverberation method with the use of interrupted noise.
Hammerstein Nonlinear Active Noise Control with the Filtered-Error LMS Algorithm
Authors: Mazur Krzysztof , Pawełczyk Marek
Published: October 2013

Active Noise Control (ANC) of noise transmitted through a vibrating plate causes many problems not observed in classical ANC using loudspeakers. They are mainly due to vibrations of a not ideally clamped plate and use of nonlinear actuators, like MFC patches. In case of noise transmission though a plate, nonlinerities exist in both primary and secondary paths.

Existence of nonlinerities in the system may degrade performance of a linear feedforward control system usually used for ANC. The performance degradation is especially visible for simple deterministic noise, such as tonal noise, where very high reduction is expected. Linear feedforward systems in such cases are unable to cope with higher harmonics generated by the nonlinearities. Moreover, nonlinearities, if not properly tackled with, may cause divergence of an adaptive control system.

In this paper a feedforward ANC system reducing sound transmitted through a vibrating plate is presented. The ANC system uses nonlinear control filters to suppress negative effects of nonlinearies in the system. Filtered-error LMS algorithm, found more suitable than usually used Filtered-reference LMS algorithm, is employed for updating parameters of the nonlinear filters. The control system is experimentally verified and obtained results are discussed.
Urban Noise Annoyance Between 2001 and 2013 – Study in a Romanian City
Authors: Popescu Diana Ioana , Moholea Iuliana Fabiola , Morariu-Gligor Radu Mircea
Published: October 2013

The paper presents results of three socio-acoustic surveys conducted in an interval of twelve years, between 2001 and 2013, in a large Romanian city, Cluj-Napoca. The purpose of the surveys was to assess the awareness of residents on urban noise and the extent to which the noise environment affects their everyday life, behavior and health. The surveys were conducted in 2001, 2009 and 2013. The questionnaire used in the first survey had 16 questions and it was verified prior to study through a pilot survey, being corrected and improved. For the second and the third study, the questionnaire was enriched with eight more questions, regarding essentially the description of the residential area, criteria for its selection and also awareness about the noise map of the city. The analysis of responses defines the main characteristics of the local pattern of annoyance and reaction of the urban population to the environmental noise.
Experimental Acoustic Flow Analysis Inside a Section of an Acoustic Waveguide
Authors: Weyna Stefan , Mickiewicz Witold , Pyła Michał , Jabłoński Michał
Published: October 2013

Noise propagation within ducts is of practical concern in many areas of industrial processes where a fluid has to be transported in piping systems. The paper presents experimental data and visualization of flow in the vicinity of an abrupt change in cross-section of a circular duct and on obstacles inside where the acoustic wave generates nonlinear separated flow and vortex fields.

For noise produced by flow wave of low Mach number, laminar and turbulent flows are studied us- ing experimental sound intensity (SI) and laser particle image velocimetry (PIV) technique adopted to acoustics (A-PIV). The emphasis is put on the development and application of these methods for better understanding of noise generation inside the acoustic ducts with different cross-sections. The intensity distribution inside duct is produced by the action of the sum of modal pressures on the sum of modal particle velocities. However, acoustic field is extremely complicated because pressures in non-propagating (cut-off) modes cooperate with particle velocities in propagating modes, and vice versa. The discrete frequency sound is strongly influenced by the transmission of higher order modes in the duct. By under- standing the mechanism of energy in the sound channels and pipes we can find the best solution to noise abatement technology.

In the paper, numerous methods of visualization illustrate the vortex flow as an acoustic velocity or sound intensity stream which can be presented graphically. Diffraction and scattering phenomena occurring inside and around the open-end of the acoustic duct are shown.
Noise-Induced Hearing Loss in Professional Orchestral Musicians
Authors: Pawlaczyk-Łuszczyńska Małgorzata , Zamojska Małgorzata , Dudarewicz Adam , Zaborowski Kamil
Published: October 2013

The overall purpose of this study was to assess hearing status in professional orchestral musicians. Standard pure-tone audiometry (PTA) and transient-evoked otoacoustic emissions (TEOAEs) were per- formed in 126 orchestral musicians. Occupational and non-occupational risk factors for noise-induced hearing loss (NIHL) were identified in questionnaire inquiry. Data on sound pressure levels produced by various groups of instruments were also collected and analyzed. Measured hearing threshold levels (HTLs) were compared with the theoretical predictions calculated according to ISO 1999 (1990).

Musicians were exposed to excessive sound at weekly noise exposure levels of for 81-100 dB (mean: 86.6±4.0 dB) for 5-48 years (mean: 24.0±10.7 years). Most of them (95%) had hearing corresponds to grade 0 of hearing impairment (mean hearing threshold level at 500, 1000, 2000 and 4000 Hz lower than 25 dB). However, high frequency notched audiograms typical for noise-induced hearing loss were found in 35% of cases. Simultaneously, about 35% of audiograms showed typical for NIHL high frequency notches (mainly occurring at 6000 Hz). When analyzing the impact of age, gender and noise exposure on hearing test results both PTA and TEOAE consistently showed better hearing in females vs. males, younger vs. older musicians. But higher exposure to orchestral noise was not associated with poorer hearing tests results.

The musician’s audiometric hearing threshold levels were poorer than equivalent non-noise-exposed population and better (at 3000 and 4000 Hz) than expected for noise-exposed population according to ISO 1999 (1990). Thus, music impairs hearing of orchestral musicians, but less than expected from noise exposure.
Noise Exposure of School Teachers – Exposure Levels and Health Effects
Authors: Hadzi-Nikolova Marija , Mirakovski Dejan , Zdravkovska Milka , Angelovska Bistra , Doneva Nikolinka
Published: October 2013

Faculty of Natural and Technical Sciences and Faculty of Medical Sciences starting from December 2012, launched joint study in order to investigate personal noise exposure and associated health effects in general school teachers population, starting from kindergartens up to high schools in Stip, Macedonia.

In order to determine workplace associated noise exposure and associated health effects in this specific profession, a full shift noise exposure of 40 teachers from 1 kindergarten, 2 primary and 2 high schools were measured in real conditions using noise dosimeters.

A-weighted equivalent-continuous sound pressure levels (LAeq) of each teacher were recorded during single activities (classes). Normalized 8-hours exposure, termed the noise exposure level (Lex;8 h) was also computed. Daily noise dose is another descriptor for noise exposure that was determined as a measure of the total sound energy to which workers have been exposed, as a result of working in the varying noise levels.

Health effects were assessed trough a full scale epidemiological study which included 231 teachers from the same schools. Specific questionnaire was used to extract information about subject’s perception on occupational noise exposure, as well as theirs occupational and medical history.
Low Frequency Noise and Its Assessment and Evaluation
Authors: Žiaran Stanislav
Published: October 2013

The main aim of this paper is to present recent knowledge about the assessment and evaluation of low frequency noise and infrasound close to the threshold of hearing and the potential effects on human health. Low frequency noise generated by air flowing over a moving car with the open window is chosen as a source of noise. The noise within the interior of the car and its effects on a driver’s comfort at different velocities is analyzed. An open window at high velocity behaves as a source of specifically strong tonal low frequency noise which is annoying. The interior noise of a passenger car was measured under different conditions; while driving on normal highway and roadways. First, an octave-band analysis was used to assess the noise level and its impact on the driver’s comfort. Second, a Fast Fourier Transform (FFT) analysis was used for the detection of tonal low frequency noise. Finally, the paper suggests possibilities for scientifically assessing and evaluating low frequency noise but not only for the presented source of the sound.
The “NOMAD” Project – A Survey of Instructions Supplied with Machinery with Respect to Noise
Authors: Châtillon Jacques , Szyszko Marian
Published: October 2013

The NOMAD project was a survey to examine the noise-related content of instructions supplied with machinery offered for purchase in Europe. The project collected more than 1 500 instructions from machines covering 40 broad machine-families and from 800 different manufacturing companies. These instructions were analyzed to determine compliance with the requirements of the Machinery Directive, and assess the quality of information.

The general state of compliance of machinery instructions with the noise-related requirements of the Machinery Directive was found to be very poor: 80% of instructions did not meet legal requirements. Some required numerical values relating to noise emissions were often missing. Where values were given, they were often not traceable to machine operating conditions or measurement methods, and not credible either against stated conditions/methods or as warnings of likely risk in real use.

As a consequence, it is considered highly likely that, in making a machinery procurement decision, employers are prevented from taking noise emissions into account, and understanding what is necessary to manage the risks from noise relating to equipment that is procured.

Recommendations are made for actions aimed at bringing about a global improvement to the current situation. Targeted actions are now proposed by “ADCO Machinery Group” aimed at raising awareness of the legal requirements, responsibilities and actions required among the various groups who have parts to play in the system - machine manufacturers, machine users, occupational safety and health professionals, and standards-makers. Recommendations are also made aimed at providing, or improving, tools and resources for all these actors.
Discrimination of Acoustic Emission Signals for Damage Assessment in a Reinforced Concrete Slab Subjected to Seismic Simulations
Authors: Sagasta Francisco A. , Torné Juan L. , Sánchez-Parejo Antonio , Gallego Antolino
Published: October 2013

The purpose of this work is to distinguish between Acoustic Emission (AE) signals coming from mechanical friction and AE signals coming from concrete cracking, recorded during fourteen seismic simulations conducted with the shaking table of the University of Granada on a reinforced concrete slab supported on four steel columns. To this end, a particular criterion is established based on the Root Mean Square of the AE waveforms calculated in two different temporal windows. This criterion includes a parameter calculated by optimizing the correlation between the mechanical energy dissipated by the specimen (calculated by means of measurements with accelerometers and displacement transducers) and the energy obtained from the AE signals recorded by low-frequency piezoelectric sensors located on the specimen. The final goal of this project, initiated four years ago, is to provide a reliable evaluation of the level of damage of Reinforced Concrete specimens by means of AE signals to be used in future Structural Health Monitoring strategies involving RC structures.
Estimation of the Fundamental Frequency of the Speech Signal Compressed by MP3 Algorithm
Authors: Milivojević Zoran N. , Brodić Darko
Published: October 2013

The paper analyzes the estimation of the fundamental frequency from the real speech signal which is obtained by recording the speaker in the real acoustic environment modeled by the MP3 method. The estimation was performed by the Picking-Peaks algorithm with implemented parametric cubic convolution (PCC) interpolation. The efficiency of PCC was tested for Catmull-Rom, Greville, and Greville two- parametric kernel. Depending on MSE, a window that gives optimal results was chosen.
Preliminary Study on the Influence of Headphones for Listening Music on Hearing Loss of Young People
Authors: Dobrucki Andrzej B. , Kin Maurycy J. , Kruk Bartłomiej
Published: October 2013

The paper presents results of hearing loss measurements provided for 81 young people (from 16 to 25 years old). The main aim of the work was to find the influence of headphones of the types used (closed, semi-open, open and in-ear) on the hearing losses. The first part of the research was to answer questions about the influence of: time of listening, loudness of music, other noise exposures as well as the type of the headphones used. It turned out that all factors mentioned above influence thresholds of hearing but the found dependencies are not explicit. The greatest hearing losses were observed for people who work as sound reinforcement engineers and, moreover, no influence of the headphone types was found for them. It turned out that the use of in-ear headphones causes the greatest hearing losses for some subjects (thresholds shifted up to about 20 dB HL at 4 kHz). The daily time of a listening also affected the hearing thresholds. It was found that for users of in-ear and close headphones, an average time of musical exposure of three hours causes the hearing loss of 10-15 dB HL at higher frequencies. The use of open as well as semi-open headphones has no influence on the hearing damage. Thus it would be stated that these kinds are safety in use. Almost 15% of the investigated young people have their thresholds shifted up at higher frequencies, particularly at 4 kHz, which means that they have the first symptoms of a permanent hearing damage.
Study of the Categorisation Method Using Long-term Measurements
Authors: Gozalo Guillermo Rey , Barrigón Morillas Juan Miguel , Escobar Valentín Gómez , Vílchez-Gómez Rosendo , Méndez Sierra Juan Antonio , Carmona del Río Francisco Javier , Gajardo Carlos Prieto
Published: October 2013

Previous studies concerning the categorisation method have been based on short daytime measure- ments. These studies demonstrated urban-noise stratification in the daytime. Nevertheless, legislation and standards refer to noise estimation throughout the day. This paper presents the first attempt to apply the categorisation method to indicators obtained through long-term measurements. The study was conducted in Plasencia, Extremadura (Spain) which has approximately 41,500 inhabitants. First, we conducted a stratification of the roads using the categorisation method. Second, long-term measurements (approxi- mately one week) were conducted at different sampling locations across different categories of streets. The results were analysed by category. Moreover, the profile of the noise-level variation was analysed during the day. The results revealed a stratification of sound levels measured across the different categories. Furthermore, we found health risks due to the noise levels in this town. Short-term measurements were also conducted to complete the categorisation method suitability analysis.
The Lakescape in the Eyes of a Tourist
Authors: Potocka Ilona
Published: October 2013

Visual-esthetic landscapes values are determining a comfort of leisure in the environment, forms of tourist activities and constitute value as such. The aim of the research is to define how, and which components of lakescape are perceived by tourists, and how it influences on lake tourist activity. Presented paper describes also the role of water itself and the importance of the aesthetics of lakescape in tourist experience. The research of visual landscape values has been conducted for a long time, using different methods. The paper describes, apart from traditional method of inquires, use of eye-tracking to define elements of lakescape perceived by tourists.
Climatology of Hail in Central Europe
Authors: Suwała Katarzyna , Bednorz Ewa
Published: October 2013

Taking into consideration the spatial variability of the occurrence of hail in central Europe in the warm season (April - September) during the years 1966-2010, five hail regions were distinguished by Ward’s group hierarchy method. For this purpose the daily data of hail occurrence were used. Circulation patterns responsible for hail precipitation at each cluster of stations were analysed using Reanalysis data (NCEP/NCAR). Composite maps of the sea-level pressure, 500 hPa geopotential height and 850 hPa-level temperature means were constructed for the days with hail. Additionally, anomalies of the values of each parameter were presented. It was found that more than 65% of hail events were recorded from April to June, with May as the hail-peak month. In all five distinguished regions hail precipitation was associated with negative anomalies of SLP and 500 hPa heights over Europe, most often with low-pressure systems developing within colder than usual air mass.
Land Consolidation as an Instrument of Shaping the Agrarian Structure in Poland: A Case Study of the Wielkopolskie and Dolnośląskie Voivodeships
Authors: Markuszewska Iwona
Published: October 2013

Fragmentation of agricultural landscape is a specific feature of agrarian structure in Poland. Despite the fact that consolidation work has been carried out for years, the positive effects are still negligible. This is because land consolidation in Poland is encountering with a number of obstacles, which on the one hand, is cumbersome formal and legal policy, and on the other hand, disapproval of officials and farmers as well. These barriers unnecessarily prolong the proceeding, which is inherently long-term, sometimes takes years and not always is successfully completed. For this reason an effort was made to answer the question: how improving in land consolidation policy may look up the efficiency of land merging work in Poland? Two formal procedures were presented, on the basis of which land consolidation is carried out in two voivodeships: Wielkopolskie and Dolnośląskie. The study revealed the main obstacles and weaknesses in legal regulation. Additionally, open-interviews among farmers as well as local and regional land consolidation authorities, were undertaken. On the basis of the acquired data, a number of new suggestions to more successful land consolidation policy, were put forward. Finally, possible solutions to perk up the land unification work were established.
Influence of Biomass Pretreatment Process Time on Furfural Extraction from Birch Wood
Authors: Brazdausks Prans , Puke Maris , Vedernikovs Nikolajs , Kruma Irena
Published: October 2013

Furfural is a biomass derived-chemical that can be used to replace petrochemicals. In this study, dilute sulphuric acid hydrolysis was used for hemicelluloses secession from birch wood. The reaction was investigated at different biomass treatment times (10-90 min, increasing it by 10 min). We found that the greatest amount of furfural 1.4-2.6%, which is 9.7-17.7% from theoretical possible yield, was formed in the first 30 min of the beginning of birch wood pentoses monosaccharide dehydration, but the greatest yield of furfural 10.3%, which is 70.0% from the theoretical yield, can be obtained after 90 min. Given that furfural yield generally does not exceed 50% from the theoretical amount, the result can be considered as very good.
Design and Economic Analysis of a Heating/Absorption Cooling System Operating with Municipal Solid Waste Digester: A Case Study of Gazi University
Authors: Coşar Gökhan , Pooyanfar Mirparham , Amirabedin Ehsan , Topal Hüseyin
Published: October 2013

Recovering energy from municipal solid waste (MSW) is one of the most important issues of energy management in developed countries. This raises even more interest as world fossil fuel reserves diminish and fuel prices rise. Being one of main processes of waste disposal, anaerobic digestion can be used as a means to reduce fossil fuel and electricity consumption as well as reducing emissions. With growing demand for cooling in Turkey, especially during warm seasons and considering the energy costs, utilizing heat-driven absorption cooling systems coupled with an anaerobic digester for local cooling purposes is a potentially interesting alternative for electricity driven compression cooling. The aim of this article is to study the viability of utilizing biogas obtained from MSW anaerobic digestion as the main fuel for heating facilities of Gazi University, Turkey and also the energy source for an absorption cooling system designed for the central library of the aforementioned campus. The results prove that the suggested system is sustainably and financially appealing and has the potential to replace the conventional electricity driven cooling systems with a reasonable net present worth; moreover, it can notably reduce carbon dioxide emissions.
Technologies for Decreasing Mining Losses
Authors: Valgma Ingo , Väizene Vivika , Kolats Margit , Saarnak Martin
Published: October 2013

In case of stratified deposits like oil shale deposit in Estonia, mining losses depend on mining technologies. Current research focuses on extraction and separation possibilities of mineral resources. Selective mining, selective crushing and separation tests have been performed, showing possibilities of decreasing mining losses. Rock crushing and screening process simulations were used for optimizing rock fractions. In addition mine backfilling, fine separation, and optimized drilling and blasting have been analyzed. All tested methods show potential and depend on mineral usage. Usage in addition depends on the utilization technology. The questions like stability of the material flow and influences of the quality fluctuations to the final yield are raised.
Improved Project Management via Advancement in Evaluation Methodology of Regional Cooperation Environmental Projects
Authors: Zvingule Laura , Kalnins Silvija Nora , Blumberga Dagnija , Gusca Julija , Bogdanova Marija , Muizniece Indra
Published: October 2013

The financial mechanism within the European Union that is accessible for environmental issues is a tool by which it is possible to maintain and improve the state of the environment in the Baltic Sea region countries. However, the accessibility and use of finances cannot be considered indicators which mark the success of a programme. There are various evaluation types which can be conducted, such as ex ante to assess the impact desirable to help gauge what projects best to support. Ex post evaluations can also be applied to pool lessons learned to make recommendations for further development. Evaluation is important for checking progress, to further support successful initiatives and to avoid financing activities which do not produce results. Evaluation of environmental projects can be particularly difficult due to their diversity in approaches and applied technologies, however currently there is a risk to limit the assessment of projects to the activity-level (what outputs have been produced, such as number of seminars and publications or campaigns, technologies installed), rather than on the primary goal - specific impacts made on the environment. The goal of this research is to develop a methodology and set of indicators for the evaluation of environmental projects to improve the evaluation of project efficiency, impact and sustainability. Regional Cooperation Environmental Projects are selected and an evaluation is conducted on these projects.
Legendre multiwavelet collocation method for solving the linear fractional time delay systems
Authors: Yousefi Sohrab , Lotfi Ali
Published: October 2013

In this article the Legendre multiwavelet basis with aid of collocation method has been applied to give approximate solution for fractional delay systems. The properties of Legendre multiwavelet are presented. These properties together with the collocation method are then utilized to reduce the problem to the solution of algebraic system. Numerical results and comparison with exact solutions in the cases when we have exact solution are given in test examples in order to demonstrate the applicability and efficiency of the method.
Two new odonate-like insect wings from the latest Norian of northern Germany
Authors: Barth Gregor , Nel André , Franz Matthias
Published: October 2013

Two new well preserved odonate (damsel-dragonflies) insect wings from the latest Norian (Upper Triassic) of two different localities are described. Although the rather long distance of more than 250 km separates the localities, the holotypes occur in comparable lithologies and are thus described together. We describe an odonate forewing, Italophlebia baueri sp. n., from an abandoned quarry at Langenberg near Seinstedt north of the Harz Mountains (Lower Saxony), which is the first occurrence of this genus outside Italy. The second wing, Triassothemis gartzii sp. n., was found in the cored well Gartz 1 (NE Germany). In both occurrences the insect wings were associated with abundant autochthonous as well as allochthonous faunal and floral remnants of shallow subaquatic environments.
Oral Health Condition Among Selected School Children in Dhaka City
Authors: Farzan MSA , Zayeed MA , Debnath S , Zerin I , Afrin S
Published: October 2013

This was a cross-sectional study on oral health conditions among selected school children in Dhaka city, this study was conducted at Ideal kinder garten and high school situated at kamarpara, Dhaka. The study was carried out among 200 children aged between 6-15 years from the month of September to December 2012. The main objective of the study was to assess the oral health conditions of school children through decayed, missing and filled teeth (DMFT) status of their teeth. Data were collected with a pretested structured questionnaire and a checklist. On analysis of data it was found that among the 200 children 101 (51%) were male and 99(49%) were female, tooth brushing twice daily 140(70%) was in comparison to once daily 60(30%). Tooth brushing before breakfast was 100(50%), after breakfast 20(10%),after dinner 80(40%). Tooth paste was used by most of the respondents 152(76%), than tooth powder 48(24%). Tooth brush was used by all of the respondents 200(100%). Among 200 respondents 69(35%) having no plaque,112(56%) had mild accumulation and 19(9%) had moderate plaque accumulation. Among 200 children 18(9%) did not have any decayed tooth, 30(15%) had only 1 tooth decay, 78(39%) had 2 teeth decay, 20(10%) had 3 teeth decay, 44(22%) had 4 teeth decay, while 10(5%) had more than 4 teeth decayed. Among 200 children 34(17%) did not have any missing tooth, 46(23%) had only 1 tooth missing, 85(43%) had 2 teeth missing, 20(10%) had 3 teeth missing, 15(7%) had 4 teeth missing, while none had more than 4 teeth missing. Among 200 children 32(16%) did not have any filled tooth, 66(33%) had only 1 tooth filled, 60(30%) had 2 teeth filled, 24(12%) had 3 teeth filled, 18(9%) had 4 teeth filled, while none had more than 4 teeth filled. Among 200 respondents 118(59%) had normal gingival condition while 82(41%) had red swollen gingiva. On the basis of the finding it was concluded that dental caries in children is a major health concern and creating awareness among the public about their own and their childrens oral health through appropriate plan and policy can reduce the burden of dental diseases. Moreover mass media and general education of the people can play vital role in this regard.DOI: http://dx.doi.org/10.3329/bjdre.v3i1.16591 Bangladesh Journal of Dental Research & Education Vol.3(1) 2013: 21-24
Introduction to Fiber Reinforced Composite (FRC) Post, A New Era in Reinforcing Esthetics: A Case Report
Authors: Jan CM , Rashid F , Nomann NA , Rashid AJ
Published: October 2013

The restoration of a root canal treated or, endodontically treated teeth, is often can be achieved with post and core because of the significant loss of tooth structure. Until the mid-1980s, the safest way to restore an endodontically treated tooth was considered to be the cast-metal post, made indirectly by a dental technician. Also prefabricated metal posts in combination with different core materials under artificial crowns were used. The development and use of fiber reinforced composite (FRC) root canal posts over metallic posts make possible of the attachment & reinforcement of the crown with maximum esthetics. This paper illustrates a technique for rehabilitation of an endodontically treated maxillary central incisor of both sides (UL1 & UR1) with a fiber reinforced composite post (FRC post) & discusses the advantages, disadvantages of metallic post over fiber reinforced composite (FRC) posts.DOI: http://dx.doi.org/10.3329/bjdre.v3i1.16595 Bangladesh Journal of Dental Research & Education Vol.3(1) 2013: 45-48
Sublinear Time Motif Discovery from Multiple Sequences
Authors: Fu Bin , Fu Yunhui , Xue Yuan
Published: October 2013

In this paper, a natural probabilistic model for motif discovery has been used to experimentally test the quality of motif discovery programs. In this model, there are k background sequences, and each character in a background sequence is a random character from an alphabet, Σ. A motif G = g1g2 ... gm is a string of m characters. In each background sequence is implanted a probabilistically-generated approximate copy of G. For a probabilistically-generated approximate copy b1b2 ... bm of G, every character, bi, is probabilistically generated, such that the probability for bi ≠ gi is at most α. We develop two new randomized algorithms and one new deterministic algorithm. They make advancements in the following aspects: (1) The algorithms are much faster than those before. Our algorithms can even run in sublinear time. (2) They can handle any motif pattern. (3) The restriction for the alphabet size is a lower bound of four. This gives them potential applications in practical problems, since gene sequences have an alphabet size of four. (4) All algorithms have rigorous proofs about their performances. The methods developed in this paper have been used in the software implementation. We observed some encouraging results that show improved performance for motif detection compared with other software.
Relaxation to Fixed Points in the Logistic and Cubic Maps: Analytical and Numerical Investigation
Authors: De Oliveira Juliano , Papesso Edson , Leonel Edson
Published: October 2013

Convergence to a period one fixed point is investigated for both logistic and cubic maps. For the logistic map the relaxation to the fixed point is considered near a transcritical bifurcation while for the cubic map it is near a pitchfork bifurcation. We confirmed that the convergence to the fixed point in both logistic and cubic maps for a region close to the fixed point goes exponentially fast to the fixed point and with a relaxation time described by a power law of exponent -1. At the bifurcation point, the exponent is not universal and depends on the type of the bifurcation as well as on the nonlinearity of the map.
Polyphenol-Retaining Decaffeinated Cocoa Powder Obtained by Supercritical Carbon Dioxide Extraction and Its Antioxidant Activity
Authors: Kobori Kinji , Maruta Yuto , Mineo Shigeru , Shigematsu Toru , Hirayama Masao
Published: October 2013

Cocoa beans contain many functional ingredients such as theobromine and polyphenols, but also contain a relatively high amount of caffeine, which can negatively impact human health. It is therefore desirable to reduce caffeine levels in cocoa powder used to make chocolate or cocoa beverages while retaining functional ingredients. We have established conditions for supercritical carbon dioxide (SCCO2) extraction that remove 80.1% of the caffeine from cocoa powder while retaining theobromine (94.1%) and polyphenols (84.7%). The antioxidant activity of the decaffeinated cocoa powder (DCP) made with this optimized SCCO2 extraction method was 85.3% that of non-processed cocoa powder. The total procyanidin and total polyphenol concentrations of the DCPs resulting from various SCCO2 extractions showed a significant positive correlation with oxygen radical absorbance capacity (ORAC). The correlation coefficient between total polyphenols and ORAC was higher than that between total procyanidins and ORAC; thus, the concentration of total polyphenols might be a greater factor in the antioxidant activity of DCP. These results indicate that we could remove large quantities of caffeine from conventional high-cocoa products while retaining the functional benefits of high polyphenol content. This SCCO2 extraction method is expected to be applicable high-cocoa products, such as dark chocolate.