bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical Behaviour of 3D Printed PLA Hollow Spherical Parts Under Axial Compression
Authors: Hrituc Adelina , Mihalache Andrei , Mares Marian , Coteata Margareta , Dodun Oana , Nagit Gheorghe , Slatineanu Laurentiu
Published: April 2020

The form of the outer and inner surfaces of hollow spherical parts determines the developments of some particular categories of efforts during the compression tests. The overall purpose of the research presented in this paper was to study the behaviour of the hollow spherical parts under axial compression. The PLA hollow spherical parts were obtained by 3D printing and using distinct values for certain process input factors. The finite element method was used to theoretically investigate the behaviour of the parts and it highlighted the total plastic deformation of the test pieces. To experimentally verify the theoretical considerations, an L9 Taguchi orthogonal design was performed. The empirical mathematical model thus determined highlighted the stronger influence exerted by the printing plate temperature, printing speed, and part wall thickness.
Experimental Investigation, Modeling and Optimization of Circularity, Cylindricity and Surface Roughness in Drilling of PMMA Using ANN and ANOVA
Authors: Susac Florin , Stan Felicia
Published: April 2020

In this paper, experimental investigation, modeling and optimization of the drilling of PMMA are performed using the Taguchi Design of Experiments (DOE), analysis of variance (ANOVA) and artificial neural networks (ANN) methods. Drilling experiments were conducted on PMMA to assess the impact of process parameters (drill diameter, spindle speed, and feed rate) on the hole-quality characteristics (surface roughness, circularity error, and cylindricity error). ANOVA was performed to identify the drilling parameters that have a statistically significant influence on the hole-quality characteristics. A predictive model for the hole-quality characteristics was derived using a four-layer ANN with a backpropagation algorithm and a sigmoidal transfer function at the hidden layers. The ANN model was able to accurately predict the hole-quality parameters with the absolute mean relative errors of the testing data in the limits of 3 to 7%. Based on the experimental results and analytical modeling, it was found that drilling of PMMA requires lower spindle speed and high feed rate when the integrity of the drill hole is the main quality criterion.
A Study Regarding the Mechanical Properties of a Hybrid Matrix with Various Volume Proportions of Dammar
Authors: Bolcu Dumitru , Stanescu Marius Marinel , Ciuca Ion , Miritoiu Cosmin Mihai , Dinita Alin , Bolcu Alexandru
Published: April 2020

This paper studies the influence of the volume proportion between components on the mechanical behaviour of a hybrid resin obtained by combining the natural resin Dammar and epoxy resin. We analyse three sets of hybrid resin samples, in which we used a Dammar volume proportion of 60%, 70%, and 80% respectively and epoxy resin (employed together with its associated reinforcement in order to generate a quick process of polymerization). Following the tensile test we found the characteristic curves, the tensile strength and the elongation at break for each of the three types of resins. We also looked into the vibration damping properties of bars made of this resin. We experimentally determined the frequency and the damping coefficient of the first particular vibration mode for one bar taken out of each set of resins, with one end fixed and the other free. On the basis of the results, we calculated the loss coefficient for each type of resin.
The Behavior of Polymeric Blends (PP + PA6) in Tensile Tests
Authors: Musteata Andreea Elena , Pelin George , Botan Mihail , Popescu Adrian , Deleanu Lorena
Published: April 2020

This paper presents the influence of component concentration for a class of polymeric blends with different concentration of PP (polypropylene) and PA6 (polyamide 6) and a constant concentration of additives: CaCO3, LDPE (low density polyethylene) and a compatibilizer POLYBOND� 3200. Mechanical properties has been investigated for four different test speeds, from 10 mm/min to 1000 mm/min. Young�s modulus performs in a band between 1500...1900 MPa, except for the value for PA6 at the lowest testing speed (v=10 mm/min), that is 1444 MPa. At high concentration of PA6, there were noticed voids in the longitudinal direction of the samples, forming large parallel �empty channels�, as the two polymers are immiscible. Except for values at low testing speed, the average values for tensile stress at break perform in a band of less than 8 MPa. The elongation at break is less than 10% for all materials, except for PA6 at the lowest testing speed, when a higher value was obtained. The lowest values were obtained for the blend with 20% PA6. For blends with 60% and 80% PA6, the difference between values, at the same testing speed, is the smallest. Energy at break has a slightly increase with the concentration of PA6. From the mechanical point of view, among the formulated blends, material D (with 80% PA6) is the most promising as has the highest values for stress and energy at break (11.8 J at v=10 mm/min and 9.6 J at v=1000 mm/min), but values are still less than those for PA6.
Study on Increasing Performances of Hybrid Composite Through Pull Out Compression Test Assessement
Authors: Maier Raluca
Published: April 2020

The exhaustive use of light advanced polymer composites into the development of the future high-efficiency long-range commercial aircrafts (primary) structures for increasing strength while decreasing weight for lower fuel consumption and less pollution has attracted great attention in the last decade. In this context, solutions for the integration and joining composites into the aircraft structures metallic sub-assemblies or components, while providing the necessary strength to sustain heavily loaded joints, are urgently required. The paper comes to meet an area of interest for many researchers and large integrators and manufacturers, by presenting several type of metallic join geometrical designs, along with metallic joint part integration solutions into a composite structure directly during production. Performances evaluation of the developed metallic join geometrical designs was performed in static regime by means of �pull-out� compressive tests. The paper focuses on the strength of the hybrid metallic/advanced polymer composites joints. It was concluded that an efficient design of the metallic joint and a proper transition from hybrid to the composite structure can lead to proper integration solutions while assuring safety requirements.
Research on the Effect of Aortic Valve Replacement with Mechanical Prosthesis on the Evolution of Ventricular Hypertrophy in Patients with Degenerative Aortic Stenosis
Authors: Rada Maria , Berceanu-Vaduva Delia Mira , Velimirovici Milan Daniel , Dragan Simona , Berceanu-Vaduva Bianca , Berceanu-Vaduva Marcel Mihai , Radulescu Matilda , Tudoran Cristina , Pah Ana Maria , Velimirovici Dana Emilia
Published: April 2020

Aortic valvulopathies, and especially aortic stenosis (AS), are the most common valvular disorders. Untreated, 50% of patients with severe AS will die within 2-3 years from the onset of symptomatology. The standard treatment consists in the surgical replacement of the aortic valve with mechanical or biological prosthesis. 40 patients were included in the study after replacement of the aortic valve with double disc mechanical prosthesis for severe degenerative AS. The disks of the prosthesis are made of pyrolytic carbon characterized by extreme hardness, which provides wear protection over the years. The ring is composed of a graphite substrate coated with pyrolytic carbon and attached to a suture collar made of polyethylene (polytetrafluoroethylene - PTFE) or polyester (Dacron� or Teflon�). This study evaluates mass regression and left ventricular mass index at three months and one year postoperatively. The regression of the left ventricular mass at 3 months after the surgery is 25.86%, and at one year after the surgery this regression was reduced - 15.11%. The regression of the mass of the left ventricle and especially the premature regression, correlated with the degree of hypertrophy of the left ventricle preoperatively, highlight the beneficial effect of the double disc mechanical prosthesis.
Comparison of Fracture Resistance of Teeth Presenting non-carious Cervical Lesions, Restored with Different Composite Materials
Authors: Margarit Ruxandra , Tanasescu Livia Alice , Bodnar Dana , Ion Camelia Gabriela , Burlibasa Mihai , Bisoc Adriana , Farcasiu Catalina , Dina Magdalena Natalia , Andrei Oana Cella
Published: April 2020

The aim of our study was to compare the fracture resistance of teeth presenting non-carious cervical lesions restored with different types of esthetic composite materials. 20 extracted unspoiled maxillary first molars were mechanically cleaned and immersed in saline solution containing 0.1% thymol at 4�C for a period of 48 hours. Cervical cavities with a cervical-occlusal diameter of 2 mm and a mesial-distal diameter of 3mm were filled with ormocer, flow nano-composite, nano-composite and compomer. Fracture resistance was tested with a universal loading machine (Lloyd Instruments), with a maximum force of 5 kN and a crosshead speed of 1.0 mm/min; the authors used NEXYGEN Data Analysis Software and ANOVA method. For the group A (commercial grade ormocer), the smallest load that determined the sample failure was 650 N and the highest load was 1050 N, the mean value being 858 N � 150.89 N. For the group B (commercial grade flow nano-composite), the smallest load is 530 N, the highest load is 800 N, mean value being 654 N � 112.6 N. For the group C (commercial grade nano-composite), the smallest load is 680 N, the highest load is 1200 N, mean value being 926 N � 209.35 N. For the group D (commercial grade compomer), the smallest load is 1100 N, highest load is 1250N, mean value being 1180 N � 62.04 N. A p value of 0.000311 (p[0.05) shows that there are significant differences between the four groups. Conclusions. The best fracture resistance of teeth presenting non-carious cervical lesions, restored with different types of esthetic composite materials is assured by the compomer, followed by the nano-composite, which proved to be superior to ormocer. The flow nano-composite gives the lowest fracture resistance.
The Improvement of Polymer Structure Related to Radical Treatment of Alveolar Abcesses
Authors: Budacu Cristian Constantin , Antohe Magda-Ecaterina , Costan Victor , Raftu Gheorghe , Gurau Gabriela , Pavel Liliana Lacramioara , Stefanescu Victorita
Published: April 2020

Painful periapical manifestations are inflammatory responses of periapical connective tissue to pulpal irritants, when the exudative forces become hyperactive. From the point of view of tooth preservation, apical resection is a valuable procedure in avoiding early edentation, as it is a factual surgical method that comes to aid the conservative endodontic therapy. Polymers are chemical compounds (in most cases organic) with large molecules (macromolecules) obtained from the union of a molecular chain (catena) of a large number of monomers usually with identical structural units. In our research we evaluated the resistance to traction 9 test specimens for which the structure was aimed at the improvement of the self-polymerizable acrylic structure by adding sodium maleate co-polymers, namely maleic anhydride, whose structure was linked to the anti-microbial substances, of the thymol type with controlled release, versions with greater resistance, they found clinical applicability on 244 cases. An increased resistance to fracture was registered for the test specimens II, which unites polymer powder together with the sodium maleate co-polymer, in a ratio of 3 to 1 (F = 1030 and max = 37.73), test specimen III, which unites polymer powder together with the co- anhydride maleic polymer, in a ratio of 3 to 1 (F = 950 and max = 37.88), followed by the same combinations to which it was added the care antibacterial substance, thymol. An important role in the long term in the success of the apical resection, in addition to the applied surgical technique, accrues to the retrograde obturation material, which insures an optimal healing at the peri-apical level insuring the bony apposition at this level.
КОНЦЕПЦІЯ ОСВІТИ ДІТЕЙ РАННЬОГО ТА ДОШКІЛЬНОГО ВІКУ: НОВИЙ ПОГЛЯД
Authors: Sysoieva Svitlana , Reipolska Olha
Published: April 2020

Представлено головні положення проєкту Концепції освіти дітей раннього та дошкільного віку, яку розглянуто на засіданні Президії НАПН України 27 лютого 2020 р., та оприлюднено для громадського обговорення на вебсайті НАПН України. У доповіді-презентації розкрито мету Концепції, яка полягає у забезпеченні системних змін в освіті дітей раннього та дошкільного віку, управлінні системою дошкільної освіти на різних її рівнях задля формування стратегічного ресурсу країни – якісного людського капіталу. Обґрунтовано актуальність і доцільність Концепції, наведено чітко вибудовану її структуру та охарактеризовано п’ять розділів: «Стан освіти дітей раннього та дошкільного віку в Україні»; «Стратегічні напрями розвитку освіти дітей раннього та дошкільного віку»; «Законодавчі й управлінські передумови реалізації концепції»; «Фінансування»; «Очікувані результати»; «Ризики, пов’язані з реалізацією концепції» та списку використаних термінів. Концептуальні засади модернізації системи дошкільної освіти розроблені з ініціативи вчених НАПН України та законотворців, а також за участю науково-педагогічних працівників і освітян. З-поміж авторів / укладачів проєкту Концепції: В.А. Воронов, голова підкомітету з питань раннього розвитку та дошкільної освіти Комітету Верховної Ради України з питань освіти, науки та інновацій; Н.В. Гавриш, гол. наук. співр. лабораторії дошкільної освіти і виховання Інституту проблем виховання НАПН України, докт. пед. наук, професор; Л.В. Канішевська, заступник директора з науково-експериментальної роботи Інституту проблем виховання НАПН України, докт. пед. наук, професор; Т.О. Піроженко, завідувачка лабораторії психології дошкільника Інституту психології імені Г.С. Костюка НАПН України, докт. психол. наук, професор, член-кореспондент НАПН України; О.Д. Рейпольська, завідувачка лабораторії дошкільної освіти і виховання Інституту проблем виховання НАПН України, канд. пед. наук, доцент; С.О. Сисоєва, академік-секретар Відділення загальної педагогіки та філософії освіти НАПН України, докт. пед. наук, професор, дійсний член (академік) НАПН України.
ПРО ПРОГРАМУ СПІЛЬНОЇ ДІЯЛЬНОСТІ НАЦІОНАЛЬНОЇ АКАДЕМІЇ НАУК УКРАЇНИ ТА НАЦІОНАЛЬНОЇ АКАДЕМІЇ ПЕДАГОГІЧНИХ НАУК УКРАЇНИ НА 2020-2022 РОКИ
Authors: Kremen Vasyl
Published: April 2020

Вчені НАН та НАПН України разом підготували, розглянули й запланували конкретні спільні наукові й науково-практичні розробки у рамках Програми спільної діяльності Національної академії наук України та Національної академії педагогічних наук України на 2020-2022 роки. За результатами співпраці вчених НАН і НАПН України передбачається розроблення інформаційно-аналітичних матеріалів та рекомендацій Національній раді з питань розвитку науки і технологій, МОН України, Комітету Верховної Ради України з питань освіти, науки та інновацій; методик створення підручників та навчальної літератури для закладів початкової, середньої, професійної (професійно-технічної), фахової передвищої та вищої освіти; створення сучасних технологій і методик підвищення кваліфікації практичних працівників спеціальних і інклюзивних закладів освіти, а також осіб з порушеннями психофізичного розвитку; експериментальної освітньої програми спеціалізованої освіти наукового спрямування для обдарованих дітей; освітніх і навчальних програм для підготовки фахівців, зокрема майбутніх кваліфікованих робітників аграрної, будівельної та автотранспортної галузей; спільних навчальних програм для підготовки докторів філософії за відповідними напрямами, силабусів; науково-методичних посібників, навчально-методичних комплексів проектного професійного навчання, електронних навчальних засобів, методичних рекомендацій, статей тощо. Така спільна діяльність сприятиме науково обґрунтованій імплементації кращого досвіду реалізації законів про освіту та наукову і науково-технічну діяльність, принципів і практик наукової освіти як нової освітньої парадигми, концептуальних засад і технологій цифровізації усіх ланок освіти.
Exfoliation in a low boiling point solvent and electrochemical applications of MoO3
Authors: Sricharan Matangi , Gupta Bikesh , Moolayadukkam Sreejesh , Matte H S S Ramakrishna
Published: April 2020

MoO3 is a versatile two-dimensional transition metal oxide having applications in areas such as energy storage devices, electronic devices and catalysis. To efficiently utilize the properties of MoO3 arising from its two-dimensional nature exfoliation is necessary. In this work, the exfoliation of MoO3 is carried out in 2-butanone for the first time. The achieved concentration of the dispersion is about 0.57 mg·mL−1 with a yield of 5.7%, which are the highest values reported to date. These high values of concentration and yield can be attributed to a favorable matching of energies involved in exfoliation and stabilization of MoO3 nanosheets in 2-butanone. Interestingly, the MoO3 dispersion in 2-butanone retains its intrinsic nature even after exposure to sunlight for 24 h. The composites of MoO3 nanosheets were used as an electrode material for supercapacitors and showed a high specific capacitance of 201 F·g−1 in a three-electrode configuration at a scan rate of 50 mV·s−1.
Modeling of the Adriatic Bora on the Croatian Coast
Authors: Berzegova Roza B. , Bedanokov Murat K. , Kuizheva Saida K.
Published: April 2020

The article considers the Adriatic bora as a phenomenon of flow around real mountains using a nonlinear analytical two-dimensional model. The atmosphere is presented as three layers: the lower layer represents the troposphere, and the other two represent the influence of the upper atmosphere. The shape of the relief is taken into account accurately, the interaction of the flows in the studied layers is approximate. It has been deduced that disturbances over the main ridge and in the leeward zone over the mountains are often characterized by the presence of a zone with rotors in the form of closed vortices and extended sections of vertical movements. The energy of the disturbances beyond the mountains is estimated by the jet stream velocity at the leeward slope. It has been deduced that its value lies in the range of 19–40 m/s. It’s been deduced that the characteristic cold snap during the bora is determined by the arrival of a colder air mass in the region, and not by the flow process itself. The height and the steepness of the leeward slope of the mountains, as well as the effects of turbulization of movements in the leeward zone are determining factors in increasing the velocity in the surface layer over the mountains.
Modern Distribution and Ecological-phytocenotic Features of Platanthera chlorantha (Cust.) Rchb. in the Republic of Adygea
Authors: Shadge Aminet E. , Sirotyuk Emilia A. , Gunina Galina N. , Khiryanov Vladimir V.
Published: April 2020

During the monitoring of rare plant species in the Maykop region of the Republic of Adygea, known and discovered new locations of P. chlorantha were confirmed, for which the height above sea level and geographical coordinates were determined. The identification of the species to a certain range of altitudes above sea level and types of phytocenoses was revealed. Ongenetic states, ontogenetic structure and intraspecific variability of P. chlorantha were studied in populations.
First record of Chaetopteroides kosovarorum Ibrahimi & Oláh, 2013 (Insecta: Trichoptera) from the Republic of North Macedonia
Authors: Bilalli Astrit , Ibrahimi Halil , Musliu Milaim , Gashi Agim , Grapci-Kotori Linda , Slavevska-Stamenkovič Valentina , Hinič Jelena , Geci Donard
Published: April 2020

Caddisfly specimens were collected with entomological net and ultraviolet light trap during 2016 and 2017 at eight localities in North Macedonia, Kosovo and Serbia. During this investigation we found 13 species. Here we report first record of Chaetopteroides kosovarorum from North Macedonia, as well as new localities for this species in Kosovo and Serbia. This species belongs to an extremely rare genus, inhabiting only few mountainous areas in the Balkans, and until recently has been reported only from its type locality in Kosovo.Beside this, several other rare species were recorded during this investigation such as: Rhyacophila obtusa and Drusus botosaneanui.
Phytoplankton Exopolymers Enhance Adhesion of Microplastic Particles to Submersed Surfaces
Authors: Sakhon Evgeniy G. , Mukhanov Vladimir S. , Khanaychenko Antonina N.
Published: April 2020

Intense pollution of marine environments with plastic waste, including micro- and nanoplastics, is a new and poorly studied threat measured in tens of million tonnes annually. Despite a huge scale of the problem, almost nothing is known about pathways and mechanisms of involvement of micro- and nanoplastics in marine food webs, trophic processes, global biogeochemical cycles. In this study, a hypothesis is considered and experimentally verified about the role exopolymers from marine phytoplankton play in flocculating micro- and nanoplastics and forming their aggregates in marine environments to transfer and deposit them further in bottom sediments. In experiments with non-axenic cultures of the cryptophyte Rhodomonas salina (RHO) and the green alga Tetraselmis suecica (TET) exposed to micro-polystyrene particles (MP, 4.3 μm diam., about 0.4 × 106 particles/ml, 16 mg/L), microalgal exudates were shown to promote MP flocculation and immobilization on vertical glass surfaces. The highest levels of MP were “cleared” from the medium by the TET culture which released more extracellular polysacharides. Hetero-aggregation of MP and algal cells was not observed, probably owing to turbulent mixing and cell motility. Abundant bacterial consortia relealed in the cultures (up to 9 × 106 cells ml-1) could be an additional source of exopolymers and serve an agent of MP flocculation and adhesion. Thus, the results obtained highlight the potential for phytoplankton exudates to interact with micro- and nanoplastics, and potentially affect their bioavailability and vertical transport in marine environments.
Intelligent Control of Vibration Energy Harvesting System
Authors: Almajdy Nizar , Thjel Rabee , Ali Ramzi
Published: April 2020

The Intelligent Control of Vibration Energy Harvesting system is presented in this paper. The harvesting systems use a mechanical vibration to generate electrical energy in a suitable form for use. Proportional-Integrated-derivative controller and Fuzzy Logic controller have been suggested; their parameters are optimized using a new heuristic algorithm, the Camel Traveling Algorithm(CTA). The proposed circuit Simulink model was constructed in Matlab facilities, and the model was tested under various operating conditions. The results of the simulation using the CTA was compared with two other methods.
An Event-based Spatiotemporal Approach
Authors: Wang Shuo , Nakayama Ken , Kobayashi Yoshitake , Maekawa Mamoru
Published: April 2020

With the development of temporal GIS (TGIS), users are not satisfied with the traditional static 2-dimensioinal maps any more, for the real-world entities are evolving in both space and time. Many papers have been brought to propose data models and query languages for TGIS applications. However they are not really adapted for the representation of dynamic geographical phenomena. The current concept of version is not suitable for storing continuous entity evolving information. To fulfil this work, this paper discusses the extended concept of version, called dynamic version, for modelling spatiotemporal entity evolution. The new definition of events and processes this paper presented allows for comprehensive decomposition and representation of complex spatiotemporal phenomena. Two application examples of our approach are brought out to discuss how we express temporal relationships among geographical entities and links describing their joint evolution.
Java Mobile Code Security by Bytecode Analysis
Authors: Bian Gaowei , Nakayama Ken , Kobayashi Yoshitake , Maekawa Mamoru
Published: April 2020

Since mobile code can migrate from a remote site to a host and can interact with the resources and facilities of the host, security becomes the key to the success of mobile code computation. Existing mobile code security mechanisms such as access control are not able to fully address the import security properties of the host including confidentiality and integrity. And these practices tend to protect the host from potential attacks by confining the mobile code, thus will impair the function of mobile code. Information-flow policy is a technique that can ensure confidentiality, however the analysis of the information flow is practically difficult. This paper describes an innovative approach to provide Java mobile code system security by bytecode analysis. The key technique of the approach is the dependence analysis adapted to information flow analysis. A security model for mobile code system is also proposed in this paper. By this approach, two major properties of the host security– integrity and confidentiality can be protected while the additional restriction on mobile code can be greatly avoided. A prototype has been implemented, which can be applied to analyze Java class file, applet and mobile agent.
Mitigation of Non-linear Distortion Using PTS and IDAR Method for Multi-Level QAM-OFDM System
Authors: Boonsrimuang Pisit , Boonsrimuang Pornpawit , Mori Kazuo , Paungma Tawil , Kobayashi Hideo
Published: April 2020

The future satellite communication systems are required to support the higher transmission data rate for providing the multimedia services by employing the efficient modulation method such as multi-level QAM. The employment of single carrier transmission with multi-level QAM would cause the fatal degradation of signal quality due to the non-linear amplifiers located at the earth station and satellite. To overcome this problem, we have proposed the multilevel QAM-OFDM technique with IDAR (Improved Decision Aided Reconstruction) method designed for non-linear satellite channel. However, the proposed method could not mitigate the non-linear distortion sufficiently when modulation level becomes higher such as 64QAM. This paper proposes the combined scheme of partial transmission sequence (PTS) and OFDM-IDAR methods so as to enable the usage of higher multi-level QAM method, which can achieve the higher transmission data rate with keeping the better bit error rate performance in the non-linear satellite channel. The various computer simulations are conducted in this paper to verify the effectiveness of proposed method in the non-linear satellite channel.
PP Attachment Ambiguity Resolution with Corpus-Based Pattern Distributions and Lexical Signaturese
Authors: Gala Nuria , Lafourcade Mathieu
Published: April 2020

We propose a method mixing unsupervised learning of lexical pattern frequencies with semantic information which aims at improving the resolution of PP attachment ambiguity. Using the output of a robust parser, i.e. the set of all possible attachments for a given sentence, we query the Web and obtain statistical information about the frequencies of the attachments distributions as well as lexical signatures of the terms on the patterns. All this information is used to weight the dependencies yielded by the parser and eventually to choose of the most probable attachment.
The Development of a Thai Spoken Dialogue System
Authors: Wutiwiwatchai Chai
Published: April 2020

This article summarily reports the development of the first Thai spoken dialogue system (SDS), namely a Thai Interactive Hotel Reservation Agent (TIRA) . In the development, a multi-stage technique of spoken language understanding (SLU), which combined a word spotting technique for concept extraction and a pattern classification technique for goal identification, was proposed. To improve system performance, a novel approach of logical n-gram modeling was developed for concept extraction in order to enhance the SLU robustness. Furthermore, dialogue contextual information was used to help understanding and finally, an error detection mechanism was constructed to prevent unreliable interpretation outputs of the SLU. All the mentioned algorithms were incorporated in the TIRA system and evaluated by real users.
Non-Parametric Vector Quantization Algorithm
Authors: Sivaraks Haemwaan , Surarerks Athasit
Published: April 2020

Recently researches in vector quantization domain concentrate on improving the performance of parametric algorithms (i.e., need to specify either the codebook size or the expected distortion.) The specification of the both parameters gives the users some difficulties. We, in the research, propose a nonparametric vector quantization (NVQ) algorithm. The concept is to manage Voronoi regions with respect to the distortion decreasing rate. Experimental results point that the average distortions are statistically decreased comparing with LBG and adaptive incremental LBG algorithms at the 99% of confidence level. Both speech and image data are also includedin our consideration.
Compensated CIC-Cosine Decimation Filter
Authors: Dolecek Gordana Jovanovic , Torres Fernando Javier Trejo
Published: April 2020

This paper presents efficient modification of the CICcosine decimation filter. The second order compensator filter is introduced at low rate in order to improve the passband of interest of the overall filter. The coefficients of the compensator filter are presented in a canonical signed digits (CSD) form, and can be implemented using only adders and shifts. Consequently, the resulting filter is a multiplierfree filter and exhibits a high attenuation in the stopband, as well as a low passband droop.
Characteristic Sets for Learning k-Acceptable Languages
Authors: Jitpattanakul Anuchit , Surarerks Athasit
Published: April 2020

Learnability of languages is a challenging problem in the domain of formal language identification. It is known that the efficiency of a learning technique can be measured by the size of some good samples (representative or distinctive samples) formally called a characteristic set. Our research focuses on the characteristic set of k-acceptable languages. We proposed a Gold-style learning algorithm called KRPNI which applied the grammatical inference technique to identify a language and expressed it by a k-DFA. In this paper, we study the existence of such characteristic sets. Our theoretical results show that there exists a polynomial characteristic set for a k-acceptable language. It is found that the size of the characteristic set depends on the value of k, instead of the size of an alphabet.
No-Reference JPEG Image Quality Assessment Using Haar Wavelet Decomposition
Authors: Gunawan Irwan Prasetya , Halim Antony
Published: April 2020

This paper presents a novel method of no-reference image quality assessment for JPEG encoded images by means of multiresolution analysis using Haar wavelet decomposition. The proposed method takes advantage of the fact that JPEG encoded images are usually contaminated with blockiness artifacts. Blockiness artifact is modeled as a particular edge structure that transforms into a different edge structure when edge detection algorithm is applied. Subsequently after edge detection is performed, a 3-level Haar Wavelet Transform (HWT) is employed to construct an edge map, from which some features are derived. These features give meaningful information for blockiness distortions identification and quality assessment. The proposed quality metric was tested against publicly available JPEG subset of LIVE Image Database, whilst the detection algorithm was evaluated subjectively in terms of how well the automatic detection agrees with human’s perceived view. The detection algorithms as well as the proposed JPEG quality metric demonstrate satisfying performances.
A Low-Complexity and Low Power Design of 2D-Median Filter
Authors: Matsubara Takeaki , Moshnyaga Vasily G. , Hashimoto Koji
Published: April 2020

Impulse noise removal is a very important preprocessing operation in many computer vision applications. Usually it is accomplished by median filter with excessive sorting and therefore large power. This paper presents a new design of 2D median filter that utilizes a simple conditional filtering technique, executes fewer computations than related designs while achieving superior image quality. Experimental FPGA implementation of the proposed filtering scheme is compact, fast and low-power consuming.
Speech Enhancement Based on Linear Prediction and Correlation-Inputting Bias Free Equation Error ADF
Authors: Sasaoka Naoto , Wada Shinichi , Okello James , Itoh Yoshio , Kobayashi Masaki
Published: April 2020

In this paper, a speech enhancement technique to reduce background noise in noisy speech is proposed. We investigated the noise reconstruction system (NRS) based on linear prediction and system identification as a speech enhancement. Assuming that the background noise is generated from white noise by exciting a linear filter, the system identification estimates the background noise from estimated white noise. However, the white noise estimated by a linear prediction error filter (LPEF) includes residual speech, then the estimation accuracy of background noise is degraded at the system identification and the quality of enhanced speech is deteriorated. In order to reduce the influence of the residual speech, a lattice filter and a bias free equation error adaptive digital filter (ADF) are respectively introduced to the LPEF and system identification. The residual speech is reduced by the lattice filter which approximates a vocal-tract filter well. On the other hand, the bias free equation error ADF uses the cross-correlation between the whitened noise and a desired signal as a tap input. Since the speech does not have the correlation from the desired signal, the tap coefficients converge without the influence of speech.
Development of a Next Generation Ubiquitous Processor Chip
Authors: Fukase Masa-aki , Ichinohe Kohei , Narita Kazuki , Takaki Tatsuya , Mimura Naomichi , Sato Tomoaki , Kurokawa Atsushi
Published: April 2020

Power conscious PC processors, mobile processors, cryptography processors, RFID tags, etc. have obviously supported the trend of ubiquitous network and computing. The authors have developed a ubiquitous processor named HCgorilla under the strategy to unify these devices. The unification of those devices has been effective to achieve power consciousnessfor Green IT and secureness for ubiquitous environment. The target of this study is the shift of HCgorilla to SoC, considering the exploitation of adaptability to SoC and resource-constrained implementation is cutting edge microprocessor tendency. Since this requires the total improvement of HCgorilla, the complicated clock schemes are optimally unified together. One of most important clock schemes applied to HCgorilla is a waved MFU (multifunctional unit). Although gated clock and scan path have been supported by standard CAD tools, the wave-pipelining has been mainly done by manual tuning because it has not always been so popular. Thus, these clock schemes are totally introduced. Specific features of the improved HCgorilla and its implementation in a CMOS standard cell chip are described in this article. The HCgorilla.7 chip developed in this study is the best in view of clock speed, occupied area, power consumption, and hardware security.
Performance Evaluation of a RFID-Enabled Real Time Bus Dispatching System: Case study of the Bangkok bus system
Authors: Vanitchakornpong Kriangsak , Indra-Payoong Nakorn , Sumalee Agachai , Sriborrirux Wiroon
Published: April 2020

This paper aims to present and evaluate the performance of one of the first real-time bus dispatching system in Bangkok, Thailand. The proposed bus dispatching system receives the real-time bus location data from the RFID sensor network. The paper provides the background and brief description of both the hardware and architecture of the RFID sensornetwork and the real-time bus dispatching system. The bus dispatching system continuously monitors the status of each bus and updates its expected arrival time at the depot using the real-time data from the RFID sensor network. If the expected number of vehicles falls below the required level, then the bus dispatching system will adjust the service headwayand vehicle/driver assignments to minimize the impact on the service headway. The system is implemented on one of a bus lines in Bangkok. The main focus of the paper is to evaluate the performance of the implemented system by comparing the bus service qualities before and after the implementation of the real-time bus dispatching system. One month bus service data both before and after the system deployment are used in the evaluation of the bus level of service. The result illustrates the potential real-life benefit of the real-time bus dispatching system despite the simplicity of the timetable adjustment strategy.
Enhanced Performance of Particle Swarm Optimization with Generalized Generation Gap Model with Parent-Centric Recombination Operator
Authors: Worasucheep Chukiat , Pipopwatthana Charinrat , Srimontha Sujitra , Phanmak Wilasini
Published: April 2020

Particle Swarm Optimization (PSO) algorithm has recently gained more attention in the global optimization research due to its simplicity and global search ability. This paper proposes a hybrid of PSO and Generalized Generation Gap model with Parent- Centric Recombination operator (G3PCX) [25], a well-known real-coded genetic algorithm. The proposed hybrid algorithm, namely PSPG, combines fast convergence and rotational invariance of G3PCX as well as global search ability of PSO. The performance of PSPG algorithm is evaluated using 8 widely-used nonlinear benchmark functions of 30 and 200 decision variables having different properties. The experiments study the effects of its new probability parameter Px and swarm size for optimizing those functions. The results are analyzed and compared with those from the Standard PSO [14] and G3PCX algorithms. The proposed PSPG with Px = 0.10 and 0.15 can outperform both algorithms with a statistical significance for most functions. In addition, the PSPG is not much sensitive to its swarm size as most PSO algorithms are. The best swarm sizes are 40 and 50 for unimodal and multimodal functions, respectively, of 30 decision variables.
A Language Independent Approach to Identify Problematic Conversations in Call Centers
Authors: Pandharipande Meghna Abhishek , Kopparapu Sunil Kumar
Published: April 2020

Voice based call centers enable customers query for information by speaking to human agents. Most often these call conversations are recorded by call centers with the intent of trying to identify things that can help improve the performance of the call center to serve the customer better. Today the recorded conversations are analyzed by humans by listening to call conversations, which is both time consuming, fatigue prone and not very accurate. Additionally, humans are able to analyze only a small percentage of the total calls because of economics. In this paper which is based on [1], we propose a visual method to identify problem calls quickly. The idea is to sieve through all the calls and identify problem calls, these calls can then be further analyzed by human. We first model call conversations as a directed graph and then identify a directed graph structure associated with a normal call. All call conversations that do not have the structure of a normal call are then classified as being abnormal. We use the speaking rate feature to model call conversation because it can spot potential problem calls. We have experimented on real call center conversations acquired from different call centers and the results are encouraging.
Experimental Analysis of Performance Comparison on Both Linear Filter and Bidirectional Condential Technique for Spatial Domain Optical Flow Algorithm
Authors: Kesrarat Darun , Patanavijit Vorapoj
Published: April 2020

Optical flow is a method for classifying the density velocity or motion vector (MV) in a degree of pixel basis for motion classification of image in video sequences. In actual situation, many unpleasant situations usually generate noises over the video sequences. These unpleasant situations corrupt the performance in efficiency of optical flow. In turn to increase the efficiency of the MV, this research work proposes the performance comparison on linear filter and bidirectional confidential technique for spatial domain optical flow algorithms. Our experiment concentrates on the 3 classical spatial based optical flow algorithms (such as spatial correlation-based optical flow (SCOF), Horn-Schunk algorithm (HS) and Lucas-Kanade algorithm (LK)). Different standard video sequences such as AKIYO, CONTAINER, COASTGUARD, and FOREMAN are comprehensively evaluated to demonstrate the effectiveness results. These video sequences have differences in aspect of action and speed in foreground and background. These video sequences are also debased by the Additive White Gaussian Noise (AWGN) at different noise degree (such as AWGN at 25 dB, 20 dB, and 15 dB consequently). Peak Signal to Noise Ratio (PSNR) is utilized as the performance index in our observation.
A Bayesian Approach for Sound Source Estimation
Authors: Teachasrisaksakul Krittameth , Thiemjarus Surapa , Polprasert Chantri
Published: April 2020

The goal of this study is to equip a mobile service robot with an ability to navigate to the human who commands the robot by speech. Based on time delay of arrival (TDOA) features, a Bayesian approach to sound source direction estimation is proposed. The method requires low computational complexity and is feasible for real-time robot navigation. Based on an experiment with various parameter settings in an indoor environment, different factors that affect the classification accuracy have been analyzed. The experiment results have illustrated that the proposed Bayesian method outperforms both that of the Microsoft Kinect sensor and the trigonometric approach in terms of classification accuracy.
Conguring ANN for Inundation Areas Identication based on Relevant Thematic Layers
Authors: Puttinaovarat Supattra , Horkaew Paramate , Khaimook Kanit
Published: April 2020

Flooding is one of the major natural disasters that can cause not only disruptions to daily lives but also damages to our properties. The study of flood models to determine inundation areas has therefore become increasingly more important for decision makers and the authorities. Being readily accessible, the Artificial Neural Network (ANN) scheme was frequently adopted for hydrology and flood modeling. Most ANN techniques primarily take into account rainfall data and then predict runoff consequences. Despite convincing successes, they usually neglect other causative factors. This study thus focuses on configuring and improving generic ANN for inundation areas identification using various flood deterministic attributes. Accordingly, an ANN was developed using nine flood causative factors, derived from relevant thematic layers. They consist of flood plain in the past, height above sea level, water density, water blockage, sub basin areas, soil drainage capability, land uses and monthly rainfall, whose prognostic values were previously reported and assessed against the full scale census and comprehensive GIS survey with satisfying cogency. The guidelines and precautions suggested in this paper may be applied to various ubiquitous ANN based frameworks for flood forecasting and related risks assessment.
A Client-Side Cloud Cache Replacement Policy
Authors: Banditwattanawong Thepparit , Uthayopas Putchong
Published: April 2020

To deliver data-centric cloud computing services heavily relies on data networks between cloud providers and consumer premises. The continuous and rapid growth of data hosted in external private clouds accelerates downstream network-bandwidth saturation and public cloud data-out overspends. The consumer-initiated replication of cloud data to consumer locality is a solution and known as clientside cloud caching. This paper presents the core mechanism of the cloud caching, called Cloud cache replacement policy. Simulations shown that 1) Cloud saved network bandwidth, data-out charge and data loading time; 2) even Clouds performance minima outperformed three well-known web cache replacement policies across all performance metrics for almost all test cases; 3) Cloud importantly attain optimal hit and byte-hit ratios without sacrificing one to the other.
Power-Aware Logical Topology Optimization for IP-over-WDM Networks Based on Per-Lightpath Power Consumption Model
Authors: Saengudomlert Poompat
Published: April 2020

This paper considers the problem of logical topology optimization in an IP-over-WDM network, with the objective to minimize the total power consumption used to support the given traffic demands. While there are several power consuming devices in a backbone WDM network, it is assumed that major power consumption occurs at IP router ports, which are termination points of optical connections or lightpaths. The logical topology optimization problem is first formulated as an integer linear programming (ILP) problem that is computationally difficult to solve. To focus on minimizing the power consumption, it is assumed that traffic routing is not limited by link capacities. Two systematic approaches to obtain a lower bound on the power consumption are considered, namely linear programming (LP) relaxation and Lagrangian relaxation. It is shown that both methods result in the same lower bound that corresponds to shortest path routing of traffic. A heuristic based on shortest path routing and pruning of unnecessary lightpaths is then evaluated using simulation results obtained from the heuristic in comparison to the baseline case in which the logical topology is taken to be the same as the physical topology. Finally, WDM networks that support mixed line rates are considered in order to further optimize the power consumption of IP-over-WDM networks in which transmission rates over different wavelength channels are not necessarily equal.
A Novel Intercarrier Interference Cancellation for MIMO-OFDM Systems
Authors: Yiwleak Aurupong , Pirak Chaiyod
Published: April 2020

The main impairment of an orthogonal frequency division multiplexing (OFDM) systems is an intercarrier interference (ICI) effect caused by a frequency offset. A zero-padded technique designed for a conjugate cancellation scheme in MIMO-OFDM systems for ICI cancellation is proposed by padding zero between two consecutive symbols over a space-frequency domain. At the receiver, the ICI cancellation and space-frequency diversity combining techniques are proposed. In this paper, a performance analysis is investigated and analyzed. In comparison with the conventional complex conjugate scheme, the outage probability expressions of the proposed system and the repetition-coded conjugate cancellation scheme are derived for quasi-static Rayleigh fading channels. Simulation results show the close agreement with those obtained by theoretical analysis, which could be used to estimate the proposed system performance. Finally, simulation results in time-varying frequency-selective fading channels, a bit error rate (BER) performance of the proposed system is significantly improved over both the ordinary zero-padded MIMO-OFDM systems and the repetition-coded conjugate cancellation scheme when the frequency offset is not greater than 10% of subcarrier spacing. Furthermore, the proposed system is shown to be able to attain significant diversity gain.