ABSTRACT The synthesis of a series of lanthanide dicyanoaurates containing the ancillary ligand 2... more ABSTRACT The synthesis of a series of lanthanide dicyanoaurates containing the ancillary ligand 2,2': 6',2 ''-terpyridine (terpy) have been carried out by reaction of Ln3+ nitrate salts with terpy and potassium dicyanoaurate. The resultant compounds, [Ln(C15H11N3)(H2O)(NO3)(2)Au(CN)(2)] (Ln = Eu, Tb, Dy, Ho, Er, Yb), form an isostructural series as established by single-crystal X-ray diffraction studies. These studies reveal the existence of two important non-covalent interactions in these compounds. Dimeric aurophilic interactions and terpyridine pi-stacking are both present with distances of similar to 3.5 angstrom for each. Photoluminescence measurements illustrate that the Eu3+ and Tb3+ compounds display enhanced Ln-based emission due to intramolecular energy transfer from the coordinated terpy ligands. Additionally, a [Au(CN)(2)](2) dimeric excimer produces a broad, green emission band in this class of compounds, albeit reduced in intensity in several of the compounds where a reasonable energy match exists with Ln(3+) excitation bands.
The development of Internet makes plagiarism problem more and more serious. Plagiarism can be in ... more The development of Internet makes plagiarism problem more and more serious. Plagiarism can be in different types, ranging from copying texts to adopting ideas, without giving credit to the original author. Most research in plagiarism checking concentrate on string matching. This method cannot deal with intelligent plagiarism in which the same content can be expressed by different ways. To deal with this problem, this paper proposes an approach to semantic text alignment based on sentence-level topic modeling. Experiments with PAN corpora gave us much higher recalls and approximate plagdets compared to the winning system in PAN2014. It shows that topic modeling is a potential solution for detecting intelligent plagiarism.
Acta Crystallographica Section E-structure Reports Online, Nov 17, 2012
In the title compound, C 23 H 38 O 5 , the oxabicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride un... more In the title compound, C 23 H 38 O 5 , the oxabicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride unit has a normal geometry and the tetradecoxymethyl side chain is fully extended. In the crystal, molecules are linked head-to-head by C-HÁ Á ÁO hydrogen bonds, forming two-dimensional networks propagating along the a and c-axis directions. Related literature Olefinic hydrogenation of an oxabicyclo[2.2.1]hept-5-ene derivative using catalytic quantities of 10% Pd on carbon as catalyst afforded the title compound. For reviews on the Diels-Alder reaction, see: Oppolzer (1991); Pindur et al. (1993). For a review on asymmetric cycloaddion processes, see: Pellissier (2012). For a review on catalytic hydrogenations, see: Brieger & Nestrick (1974). For a review on asymmetric catalytic hydrogenation processes, see: Knowles (2002). For discussions on reaction mechanisms with specifics on kinetic and thermodynamic control, see: Lowry & Richardson (1987); Smith (2012). For a discussion on Diels-Alder selectivity using maleic anhydride, see: Palmer (2004). Experimental Crystal data C 23 H 38 O 5 M r = 394.53 Monoclinic, P2 1 =n a = 6.8541 (5) Å b = 35.206 (4) Å c = 9.2992 (7) Å = 99.060 (7) V = 2216.0 (3) Å 3 Z = 4 Mo K radiation = 0.08 mm À1 T = 180 K 0.47 Â 0.17 Â 0.02 mm Data collection Agilent Xcalibur Eos diffractometer Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2012) T min = 0.865, T max = 1.000 9120 measured reflections 4053 independent reflections 2974 reflections with I > 2(I) R int = 0.028 Refinement R[F 2 > 2(F 2)] = 0.049 wR(F 2) = 0.108 S = 1.04 4053 reflections 255 parameters H-atom parameters constrained Á max = 0.18 e Å À3 Á min = À0.19 e Å À3 organic compounds o3374 Kelly et al.
Acta Crystallographica Section E-structure Reports Online, Nov 24, 2012
and are particularly interesting due to their tendency to simultaneously present a large number o... more and are particularly interesting due to their tendency to simultaneously present a large number of these bulky ligands. In complexes of the larger lanthanides, such as [Nd(NCS) 3 {OP(C 6 H 5) 3 } 4 ], four triphenylphosphine oxide ligands are able to coordinate the metal center (Feazell et al., 2004). With smallar lanthanide ions, such as Tb(III) in the title compound, [Tb(NCS) 3 {OP(C 6 H 5) 3 } 3 ], only three phosphine ligands are observed to coordinate. Even with a 1:4 mol ratio of terbium(III) nitrate to triphenylphosphine oxide in the synthetic strategy, there are only three triphenylphosphine oxide ligands that bind to the terbium center in the resultant products. In related lanthanide complexes containing triethylphosphine oxide ligands, the larger, lighter lanthanide ions contain three phosphine ligands and the smaller, heavier lanthanide ions contain only two ligands (Bowden et al., 2012), which is also consistent with the trend observed in structural reports in the triphenylphosphine oxide complexes reported earlier and reported here. Interestingly, it seems apparent that the anhydrous nature of the lanthanide triphenylphosphine oxide systems are dominant as the title compound and past structural reports alike show this behaviour. Experimental An ethanol solution of terbium(III) nitrate hydrate (1 mmol) and potassium thiocyanate (5 mmol) were combined. The precipitated KNO 3 was removed by filtration from the reaction mixture and was discarded. After filtration, the resulting mixture was combined with an ethanol solution of triphenylphosphine oxide (4 mmol). The solution volume was reduced and the title compound crystallized as colourless single Tris(thiocyanato-κN)tris(triphenylphosphine oxide-κO)terbium(III)crystals from the solution after approximately one hour. No recrystallization was needed. Refinement H atoms were placed in calculated positions and allowed to ride during subsequent refinement, with C-H = 0.93 Å and U iso (H) = 1.2U eq (C).
Many researchers have reported that bridging analogies can productively support students' scienti... more Many researchers have reported that bridging analogies can productively support students' scientific meaning-making. How this can be understood semiotically is, however, not well understood. This research followed an ethnographic case study approach to investigate Year 11 students meaning-making through a process of transduction (Kress, 2000; Volkwyn, 2020) across the submicroscopic and symbolic domains of Johnstone's (1991) chemistry triangle. A "cross-and-portion" (CPO) model was devised as a bridging representation for learning the molar concentration and dilution concepts, informed by Peirce's triadic model (1931) which relates the meaning of a concept to its representation in a sign, and its referent. The study drew on video capture of the classroom and small group activity, and interviews. The research findings indicated that the CPO model acted as a visualisation tool that facilitated students to link from the submicroscopic to symbolic domains of Johnstone's triangle. A recursive model of meaning-making was formulated to describe how bridging representations are re-purposed to occupy shifting positions in Peirce's triad to enable meaning through the system of interpretance. Students constructed, critiqued and transducted across multiple, multimodal representations to achieve discursive fluency across the dimensions of Johnstone's triangle. The recursive model provides a fresh perspective on how students coordinate multimodal representations to learn science/chemistry.
This paper deals with designing and implementing a battery management system (BMS) for autonomous... more This paper deals with designing and implementing a battery management system (BMS) for autonomous devices, using batteries as the power source. BMSs are now available in packaged form as an integrated chip. However, these chips are often expensive and unavailable in Vietnam and the Czech markets. Besides, their ability to integrate custom functions, especially function wireless communication between BMS and workstation, is limited. In practice, monitoring the state of the battery during the device’s operation is very important to devise a suitable operating tactic. This work aims to design a system that can measure and estimate the parameters of several batteries in an unmanned autonomous device, and send the measured data to the workstation by using technology Internet of Things for monitoring and analysis during the device’s operation.
In recent years, teacher merit pay programs have garnered considerable political and financial su... more In recent years, teacher merit pay programs have garnered considerable political and financial support, spurring rapid growth in the number of research studies investigating the association between teacher pay incentives and student test scores. The burgeoning research literature on this topic presents a novel opportunity to synthesize our understanding of merit pay and its influence on student test scores. This study fills that role as a meta-analysis of reported findings from 44 primary studies. Our meta-analysis finds that the presence of a merit pay program is associated with a modest, statistically significant, positive effect on student test scores (0.052 standard deviations). We also find that effect sizes are highly sensitive to program design and study context, which suggests that while some merit pay programs have the potential to improve student test scores in some contexts, researchers and policymakers should pay close attention to how the program is structured and imple...
This article proposes an encoder-decoder network model for Acoustic Scene Classification (ASC), t... more This article proposes an encoder-decoder network model for Acoustic Scene Classification (ASC), the task of identifying the scene of an audio recording from its acoustic signature. We make use of multiple low-level spectrogram features at the front-end, transformed into higher level features through a well-trained CNN-DNN front-end encoder. The high level features and their combination (via a trained feature combiner) are then fed into different decoder models comprising random forest regression, DNNs and a mixture of experts, for back-end classification. We report extensive experiments to evaluate the accuracy of this framework for various ASC datasets, including LITIS Rouen and IEEE AASP Challenge on Detection and Classification of Acoustic Scenes and Events (DCASE) 2016 Task 1, 2017 Task 1, 2018 Tasks 1A & 1B and 2019 Tasks 1A & 1B. The experimental results highlight two main contributions; the first is an effective method for high-level feature extraction from multi-spectrogram input via the novel C-DNN architecture encoder network, and the second is the proposed decoder which enables the framework to achieve competitive results on various datasets. The fact that a single framework is highly competitive for several different challenges is an indicator of its robustness for performing general ASC tasks.
Sound event detection is an extension of the static auditory classification task into continuous ... more Sound event detection is an extension of the static auditory classification task into continuous environments, where performance depends jointly upon the detection of overlapping events and their correct classification. Several approaches have been published to date which either develop novel classifiers or employ well-trained static classifiers with a detection front-end. This paper takes the latter approach, by combining a proven CNN classifier acting on spectrogram image features, with time-frequency shaped energy detection that identifies seed regions within the spectrogram that are characteristic of auditory energy events. Furthermore, the shape detector is optimised to allow early detection of events as they are developing. Since some sound events naturally have longer durations than others, waiting until completion of entire events before classification may not be practical in a deployed system. The early detection capability of the system is thus evaluated for the classification of partial events. Performance for continuous event detection is shown to be good, with accuracy being maintained well when detecting partial events.
TELKOMNIKA (Telecommunication Computing Electronics and Control), 2019
This paper presents a nature-inspired meta-heuristic, called a stochastic fractal search based me... more This paper presents a nature-inspired meta-heuristic, called a stochastic fractal search based method (SFS) for coping with complex economic load dispatch (ELD) problem. Two SFS methods are introduced in the paper by employing two different random walk generators for diffusion process in which SFS with Gaussian random walk is called SFS-Gauss and SFS with Levy Flight random walk is called SFS-Levy. The performance of the two applied methods is investigated comparing results obtained from three test system. These systems with 6, 10, and 20 units with different objective function forms and different constraints are inspected. Numerical result comparison can confirm that the applied approach has better solution quality and fast convergence time when compared with some recently published standard, modified, and hybrid methods. This elucidates that the two SFS methods are very favorable for solving the ELD problem.
Garment and textile (G&T) industry has been playing as a driving force for the socioeconomic deve... more Garment and textile (G&T) industry has been playing as a driving force for the socioeconomic development of Vietnam. With the international integration process and rising challenges from the global market, there is a need to examine international competitiveness of Vietnam's G&T industry to find out what Vietnam should focus on to enhance its position in the global market place. This paper, by using the Generalized Double Diamond Model (GDDM), analyzed international competitiveness of Vietnam's G&T industry and compared it with China. The results showed that Vietnam was less competitive than China in all four attributes of the GDDM. The lowest competitiveness of Vietnam in comparison with China was Related and Supporting industries, followed by Factor Conditions. Therefore, the paper argued that although Vietnam should improve all of the four attributes in the long term, Vietnam must put a high priority on developing Related and Supporting Industries and then enhance Factor Conditions while maintaining its strengths over China in terms of G&T export growths and favorable business context.
From the bulbs of Vietnamese Hippeastrum equestre Herb. (Amaryllidaceae), besides the well known ... more From the bulbs of Vietnamese Hippeastrum equestre Herb. (Amaryllidaceae), besides the well known alkaloids lycorine, tazettine, and hippeastrine, a new alkaloid, phamine, has been isolated. Its structure was established by spectroscopic methods.
From the bulbs of Vietnamese Crinum amabile, besides lycorine, buphanisine and augustine, for the... more From the bulbs of Vietnamese Crinum amabile, besides lycorine, buphanisine and augustine, for the first time, ambelline, flexinine, and two new alkaloids crinamabine and 4a-dehydroxycrinamabine were isolated. Their structures were established from spectroscopic evidence.
From the bulbs of vietnamese Hippeastrum equestre Herb. (Amaryllidaceae), two novel Amaryllidacea... more From the bulbs of vietnamese Hippeastrum equestre Herb. (Amaryllidaceae), two novel Amaryllidaceae alkaloids 3-Odemethyltazettine and egonine have been isolated. Their structures were established by spectroscopic analysis (UV, MS, NMR and CD) as well as by comparison with respective spectroscopic data of tazettine and tazettadiol.
The synthesis and some physical properties of a new quasi-one-dimensional tetracyanidoplatinate, ... more The synthesis and some physical properties of a new quasi-one-dimensional tetracyanidoplatinate, Cs 4 [Pt(CN) 4 ](CF 3 SO 3) 2 (CsCP(OTf)) are reported and described in comparison to the well-known K 2 [Pt (CN) 4 ]Br 0.30 Á 3.2H 2 O (KCP). Single-crystal X-ray diffraction reveals Pt-Pt spacings to be greater than those of KCP by 5% longitudinal and 38% transverse, but much shorter than comparable spacings in other nonpartially oxidized platinates. Anomalies are observed between temperatures 100 K and 200 K: (1) Longitudinal DC conductivity is two orders of magnitude higher and is non-monotonic with temperature, showing a minimum at around 170 K. (2) Nuclear magnetic resonance (NMR) longitudinal relaxation time T 1 is at least three orders of magnitude higher than that of KCP, and is also non-monotonic with temperature, showing a sharp peak at around 120 K. Since X-ray diffraction reveals no structural transition at 120 K, these suggest a possible lattice freezing or stiffening at around 120 K.
Acta Crystallographica Section E Structure Reports Online, 2012
In the title compound, C 23 H 38 O 5 , the oxabicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride un... more In the title compound, C 23 H 38 O 5 , the oxabicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride unit has a normal geometry and the tetradecoxymethyl side chain is fully extended. In the crystal, molecules are linked head-to-head by C-HÁ Á ÁO hydrogen bonds, forming two-dimensional networks propagating along the a and c-axis directions. Related literature Olefinic hydrogenation of an oxabicyclo[2.2.1]hept-5-ene derivative using catalytic quantities of 10% Pd on carbon as catalyst afforded the title compound. For reviews on the Diels-Alder reaction, see: Oppolzer (1991); Pindur et al. (1993). For a review on asymmetric cycloaddion processes, see: Pellissier (2012). For a review on catalytic hydrogenations, see: Brieger & Nestrick (1974). For a review on asymmetric catalytic hydrogenation processes, see: Knowles (2002). For discussions on reaction mechanisms with specifics on kinetic and thermodynamic control, see: Lowry & Richardson (1987); Smith (2012). For a discussion on Diels-Alder selectivity using maleic anhydride, see: Palmer (2004). Experimental Crystal data C 23 H 38 O 5 M r = 394.53 Monoclinic, P2 1 =n a = 6.8541 (5) Å b = 35.206 (4) Å c = 9.2992 (7) Å = 99.060 (7) V = 2216.0 (3) Å 3 Z = 4 Mo K radiation = 0.08 mm À1 T = 180 K 0.47 Â 0.17 Â 0.02 mm Data collection Agilent Xcalibur Eos diffractometer Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2012) T min = 0.865, T max = 1.000 9120 measured reflections 4053 independent reflections 2974 reflections with I > 2(I) R int = 0.028 Refinement R[F 2 > 2(F 2)] = 0.049 wR(F 2) = 0.108 S = 1.04 4053 reflections 255 parameters H-atom parameters constrained Á max = 0.18 e Å À3 Á min = À0.19 e Å À3 organic compounds o3374 Kelly et al.
ABSTRACT The synthesis of a series of lanthanide dicyanoaurates containing the ancillary ligand 2... more ABSTRACT The synthesis of a series of lanthanide dicyanoaurates containing the ancillary ligand 2,2': 6',2 ''-terpyridine (terpy) have been carried out by reaction of Ln3+ nitrate salts with terpy and potassium dicyanoaurate. The resultant compounds, [Ln(C15H11N3)(H2O)(NO3)(2)Au(CN)(2)] (Ln = Eu, Tb, Dy, Ho, Er, Yb), form an isostructural series as established by single-crystal X-ray diffraction studies. These studies reveal the existence of two important non-covalent interactions in these compounds. Dimeric aurophilic interactions and terpyridine pi-stacking are both present with distances of similar to 3.5 angstrom for each. Photoluminescence measurements illustrate that the Eu3+ and Tb3+ compounds display enhanced Ln-based emission due to intramolecular energy transfer from the coordinated terpy ligands. Additionally, a [Au(CN)(2)](2) dimeric excimer produces a broad, green emission band in this class of compounds, albeit reduced in intensity in several of the compounds where a reasonable energy match exists with Ln(3+) excitation bands.
The development of Internet makes plagiarism problem more and more serious. Plagiarism can be in ... more The development of Internet makes plagiarism problem more and more serious. Plagiarism can be in different types, ranging from copying texts to adopting ideas, without giving credit to the original author. Most research in plagiarism checking concentrate on string matching. This method cannot deal with intelligent plagiarism in which the same content can be expressed by different ways. To deal with this problem, this paper proposes an approach to semantic text alignment based on sentence-level topic modeling. Experiments with PAN corpora gave us much higher recalls and approximate plagdets compared to the winning system in PAN2014. It shows that topic modeling is a potential solution for detecting intelligent plagiarism.
Acta Crystallographica Section E-structure Reports Online, Nov 17, 2012
In the title compound, C 23 H 38 O 5 , the oxabicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride un... more In the title compound, C 23 H 38 O 5 , the oxabicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride unit has a normal geometry and the tetradecoxymethyl side chain is fully extended. In the crystal, molecules are linked head-to-head by C-HÁ Á ÁO hydrogen bonds, forming two-dimensional networks propagating along the a and c-axis directions. Related literature Olefinic hydrogenation of an oxabicyclo[2.2.1]hept-5-ene derivative using catalytic quantities of 10% Pd on carbon as catalyst afforded the title compound. For reviews on the Diels-Alder reaction, see: Oppolzer (1991); Pindur et al. (1993). For a review on asymmetric cycloaddion processes, see: Pellissier (2012). For a review on catalytic hydrogenations, see: Brieger & Nestrick (1974). For a review on asymmetric catalytic hydrogenation processes, see: Knowles (2002). For discussions on reaction mechanisms with specifics on kinetic and thermodynamic control, see: Lowry & Richardson (1987); Smith (2012). For a discussion on Diels-Alder selectivity using maleic anhydride, see: Palmer (2004). Experimental Crystal data C 23 H 38 O 5 M r = 394.53 Monoclinic, P2 1 =n a = 6.8541 (5) Å b = 35.206 (4) Å c = 9.2992 (7) Å = 99.060 (7) V = 2216.0 (3) Å 3 Z = 4 Mo K radiation = 0.08 mm À1 T = 180 K 0.47 Â 0.17 Â 0.02 mm Data collection Agilent Xcalibur Eos diffractometer Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2012) T min = 0.865, T max = 1.000 9120 measured reflections 4053 independent reflections 2974 reflections with I > 2(I) R int = 0.028 Refinement R[F 2 > 2(F 2)] = 0.049 wR(F 2) = 0.108 S = 1.04 4053 reflections 255 parameters H-atom parameters constrained Á max = 0.18 e Å À3 Á min = À0.19 e Å À3 organic compounds o3374 Kelly et al.
Acta Crystallographica Section E-structure Reports Online, Nov 24, 2012
and are particularly interesting due to their tendency to simultaneously present a large number o... more and are particularly interesting due to their tendency to simultaneously present a large number of these bulky ligands. In complexes of the larger lanthanides, such as [Nd(NCS) 3 {OP(C 6 H 5) 3 } 4 ], four triphenylphosphine oxide ligands are able to coordinate the metal center (Feazell et al., 2004). With smallar lanthanide ions, such as Tb(III) in the title compound, [Tb(NCS) 3 {OP(C 6 H 5) 3 } 3 ], only three phosphine ligands are observed to coordinate. Even with a 1:4 mol ratio of terbium(III) nitrate to triphenylphosphine oxide in the synthetic strategy, there are only three triphenylphosphine oxide ligands that bind to the terbium center in the resultant products. In related lanthanide complexes containing triethylphosphine oxide ligands, the larger, lighter lanthanide ions contain three phosphine ligands and the smaller, heavier lanthanide ions contain only two ligands (Bowden et al., 2012), which is also consistent with the trend observed in structural reports in the triphenylphosphine oxide complexes reported earlier and reported here. Interestingly, it seems apparent that the anhydrous nature of the lanthanide triphenylphosphine oxide systems are dominant as the title compound and past structural reports alike show this behaviour. Experimental An ethanol solution of terbium(III) nitrate hydrate (1 mmol) and potassium thiocyanate (5 mmol) were combined. The precipitated KNO 3 was removed by filtration from the reaction mixture and was discarded. After filtration, the resulting mixture was combined with an ethanol solution of triphenylphosphine oxide (4 mmol). The solution volume was reduced and the title compound crystallized as colourless single Tris(thiocyanato-κN)tris(triphenylphosphine oxide-κO)terbium(III)crystals from the solution after approximately one hour. No recrystallization was needed. Refinement H atoms were placed in calculated positions and allowed to ride during subsequent refinement, with C-H = 0.93 Å and U iso (H) = 1.2U eq (C).
Many researchers have reported that bridging analogies can productively support students' scienti... more Many researchers have reported that bridging analogies can productively support students' scientific meaning-making. How this can be understood semiotically is, however, not well understood. This research followed an ethnographic case study approach to investigate Year 11 students meaning-making through a process of transduction (Kress, 2000; Volkwyn, 2020) across the submicroscopic and symbolic domains of Johnstone's (1991) chemistry triangle. A "cross-and-portion" (CPO) model was devised as a bridging representation for learning the molar concentration and dilution concepts, informed by Peirce's triadic model (1931) which relates the meaning of a concept to its representation in a sign, and its referent. The study drew on video capture of the classroom and small group activity, and interviews. The research findings indicated that the CPO model acted as a visualisation tool that facilitated students to link from the submicroscopic to symbolic domains of Johnstone's triangle. A recursive model of meaning-making was formulated to describe how bridging representations are re-purposed to occupy shifting positions in Peirce's triad to enable meaning through the system of interpretance. Students constructed, critiqued and transducted across multiple, multimodal representations to achieve discursive fluency across the dimensions of Johnstone's triangle. The recursive model provides a fresh perspective on how students coordinate multimodal representations to learn science/chemistry.
This paper deals with designing and implementing a battery management system (BMS) for autonomous... more This paper deals with designing and implementing a battery management system (BMS) for autonomous devices, using batteries as the power source. BMSs are now available in packaged form as an integrated chip. However, these chips are often expensive and unavailable in Vietnam and the Czech markets. Besides, their ability to integrate custom functions, especially function wireless communication between BMS and workstation, is limited. In practice, monitoring the state of the battery during the device’s operation is very important to devise a suitable operating tactic. This work aims to design a system that can measure and estimate the parameters of several batteries in an unmanned autonomous device, and send the measured data to the workstation by using technology Internet of Things for monitoring and analysis during the device’s operation.
In recent years, teacher merit pay programs have garnered considerable political and financial su... more In recent years, teacher merit pay programs have garnered considerable political and financial support, spurring rapid growth in the number of research studies investigating the association between teacher pay incentives and student test scores. The burgeoning research literature on this topic presents a novel opportunity to synthesize our understanding of merit pay and its influence on student test scores. This study fills that role as a meta-analysis of reported findings from 44 primary studies. Our meta-analysis finds that the presence of a merit pay program is associated with a modest, statistically significant, positive effect on student test scores (0.052 standard deviations). We also find that effect sizes are highly sensitive to program design and study context, which suggests that while some merit pay programs have the potential to improve student test scores in some contexts, researchers and policymakers should pay close attention to how the program is structured and imple...
This article proposes an encoder-decoder network model for Acoustic Scene Classification (ASC), t... more This article proposes an encoder-decoder network model for Acoustic Scene Classification (ASC), the task of identifying the scene of an audio recording from its acoustic signature. We make use of multiple low-level spectrogram features at the front-end, transformed into higher level features through a well-trained CNN-DNN front-end encoder. The high level features and their combination (via a trained feature combiner) are then fed into different decoder models comprising random forest regression, DNNs and a mixture of experts, for back-end classification. We report extensive experiments to evaluate the accuracy of this framework for various ASC datasets, including LITIS Rouen and IEEE AASP Challenge on Detection and Classification of Acoustic Scenes and Events (DCASE) 2016 Task 1, 2017 Task 1, 2018 Tasks 1A & 1B and 2019 Tasks 1A & 1B. The experimental results highlight two main contributions; the first is an effective method for high-level feature extraction from multi-spectrogram input via the novel C-DNN architecture encoder network, and the second is the proposed decoder which enables the framework to achieve competitive results on various datasets. The fact that a single framework is highly competitive for several different challenges is an indicator of its robustness for performing general ASC tasks.
Sound event detection is an extension of the static auditory classification task into continuous ... more Sound event detection is an extension of the static auditory classification task into continuous environments, where performance depends jointly upon the detection of overlapping events and their correct classification. Several approaches have been published to date which either develop novel classifiers or employ well-trained static classifiers with a detection front-end. This paper takes the latter approach, by combining a proven CNN classifier acting on spectrogram image features, with time-frequency shaped energy detection that identifies seed regions within the spectrogram that are characteristic of auditory energy events. Furthermore, the shape detector is optimised to allow early detection of events as they are developing. Since some sound events naturally have longer durations than others, waiting until completion of entire events before classification may not be practical in a deployed system. The early detection capability of the system is thus evaluated for the classification of partial events. Performance for continuous event detection is shown to be good, with accuracy being maintained well when detecting partial events.
TELKOMNIKA (Telecommunication Computing Electronics and Control), 2019
This paper presents a nature-inspired meta-heuristic, called a stochastic fractal search based me... more This paper presents a nature-inspired meta-heuristic, called a stochastic fractal search based method (SFS) for coping with complex economic load dispatch (ELD) problem. Two SFS methods are introduced in the paper by employing two different random walk generators for diffusion process in which SFS with Gaussian random walk is called SFS-Gauss and SFS with Levy Flight random walk is called SFS-Levy. The performance of the two applied methods is investigated comparing results obtained from three test system. These systems with 6, 10, and 20 units with different objective function forms and different constraints are inspected. Numerical result comparison can confirm that the applied approach has better solution quality and fast convergence time when compared with some recently published standard, modified, and hybrid methods. This elucidates that the two SFS methods are very favorable for solving the ELD problem.
Garment and textile (G&T) industry has been playing as a driving force for the socioeconomic deve... more Garment and textile (G&T) industry has been playing as a driving force for the socioeconomic development of Vietnam. With the international integration process and rising challenges from the global market, there is a need to examine international competitiveness of Vietnam's G&T industry to find out what Vietnam should focus on to enhance its position in the global market place. This paper, by using the Generalized Double Diamond Model (GDDM), analyzed international competitiveness of Vietnam's G&T industry and compared it with China. The results showed that Vietnam was less competitive than China in all four attributes of the GDDM. The lowest competitiveness of Vietnam in comparison with China was Related and Supporting industries, followed by Factor Conditions. Therefore, the paper argued that although Vietnam should improve all of the four attributes in the long term, Vietnam must put a high priority on developing Related and Supporting Industries and then enhance Factor Conditions while maintaining its strengths over China in terms of G&T export growths and favorable business context.
From the bulbs of Vietnamese Hippeastrum equestre Herb. (Amaryllidaceae), besides the well known ... more From the bulbs of Vietnamese Hippeastrum equestre Herb. (Amaryllidaceae), besides the well known alkaloids lycorine, tazettine, and hippeastrine, a new alkaloid, phamine, has been isolated. Its structure was established by spectroscopic methods.
From the bulbs of Vietnamese Crinum amabile, besides lycorine, buphanisine and augustine, for the... more From the bulbs of Vietnamese Crinum amabile, besides lycorine, buphanisine and augustine, for the first time, ambelline, flexinine, and two new alkaloids crinamabine and 4a-dehydroxycrinamabine were isolated. Their structures were established from spectroscopic evidence.
From the bulbs of vietnamese Hippeastrum equestre Herb. (Amaryllidaceae), two novel Amaryllidacea... more From the bulbs of vietnamese Hippeastrum equestre Herb. (Amaryllidaceae), two novel Amaryllidaceae alkaloids 3-Odemethyltazettine and egonine have been isolated. Their structures were established by spectroscopic analysis (UV, MS, NMR and CD) as well as by comparison with respective spectroscopic data of tazettine and tazettadiol.
The synthesis and some physical properties of a new quasi-one-dimensional tetracyanidoplatinate, ... more The synthesis and some physical properties of a new quasi-one-dimensional tetracyanidoplatinate, Cs 4 [Pt(CN) 4 ](CF 3 SO 3) 2 (CsCP(OTf)) are reported and described in comparison to the well-known K 2 [Pt (CN) 4 ]Br 0.30 Á 3.2H 2 O (KCP). Single-crystal X-ray diffraction reveals Pt-Pt spacings to be greater than those of KCP by 5% longitudinal and 38% transverse, but much shorter than comparable spacings in other nonpartially oxidized platinates. Anomalies are observed between temperatures 100 K and 200 K: (1) Longitudinal DC conductivity is two orders of magnitude higher and is non-monotonic with temperature, showing a minimum at around 170 K. (2) Nuclear magnetic resonance (NMR) longitudinal relaxation time T 1 is at least three orders of magnitude higher than that of KCP, and is also non-monotonic with temperature, showing a sharp peak at around 120 K. Since X-ray diffraction reveals no structural transition at 120 K, these suggest a possible lattice freezing or stiffening at around 120 K.
Acta Crystallographica Section E Structure Reports Online, 2012
In the title compound, C 23 H 38 O 5 , the oxabicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride un... more In the title compound, C 23 H 38 O 5 , the oxabicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride unit has a normal geometry and the tetradecoxymethyl side chain is fully extended. In the crystal, molecules are linked head-to-head by C-HÁ Á ÁO hydrogen bonds, forming two-dimensional networks propagating along the a and c-axis directions. Related literature Olefinic hydrogenation of an oxabicyclo[2.2.1]hept-5-ene derivative using catalytic quantities of 10% Pd on carbon as catalyst afforded the title compound. For reviews on the Diels-Alder reaction, see: Oppolzer (1991); Pindur et al. (1993). For a review on asymmetric cycloaddion processes, see: Pellissier (2012). For a review on catalytic hydrogenations, see: Brieger & Nestrick (1974). For a review on asymmetric catalytic hydrogenation processes, see: Knowles (2002). For discussions on reaction mechanisms with specifics on kinetic and thermodynamic control, see: Lowry & Richardson (1987); Smith (2012). For a discussion on Diels-Alder selectivity using maleic anhydride, see: Palmer (2004). Experimental Crystal data C 23 H 38 O 5 M r = 394.53 Monoclinic, P2 1 =n a = 6.8541 (5) Å b = 35.206 (4) Å c = 9.2992 (7) Å = 99.060 (7) V = 2216.0 (3) Å 3 Z = 4 Mo K radiation = 0.08 mm À1 T = 180 K 0.47 Â 0.17 Â 0.02 mm Data collection Agilent Xcalibur Eos diffractometer Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2012) T min = 0.865, T max = 1.000 9120 measured reflections 4053 independent reflections 2974 reflections with I > 2(I) R int = 0.028 Refinement R[F 2 > 2(F 2)] = 0.049 wR(F 2) = 0.108 S = 1.04 4053 reflections 255 parameters H-atom parameters constrained Á max = 0.18 e Å À3 Á min = À0.19 e Å À3 organic compounds o3374 Kelly et al.
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