Comparative study to realize an automatic speaker recognition system

In this research, we present an automatic speaker recognition system based on adaptive orthogonal transformations. To obtain the informative features with a minimum dimension from the input signals, we created an adaptive operator, which helped to identify the speaker’s voice in a fast and efficient manner. We test the efficiency and the performance of our method by comparing it with another approach, mel-frequency cepstral coefficients (MFCCs), which is widely used by researchers as their feature extraction method. The experimental results show the importance of creating the adaptive operator, which gives added value to the proposed approach. The performance of the system achieved 96.8% accuracy using Fourier transform as a compression method and 98.1% using Correlation as a compression method.

Analisis Kinerja Inbound Logistik Susu Segar di Koperasi Peternak Sapi Bandung Utara (KPSBU) Lembang

North Bandung Cattle Ranching Cooperative (KPSBU) Lembang is a single primary business cooperative that acts as a distributor of fresh milk produced by cows owned by its member breeders. The distribution of fresh milk from farmers to cooperatives is a movement of material flow from suppliers to factories known as inbound logistics. This study was aimed to analyze the inbound logistics performance of fresh milk at KPSBU Lembang, its value added for the farmer, as well as the nutritional and microbiological quality. SCOR-AHP was used to analyse inbound logistics performance. The Hayami method was used to analyse value added of fresh milk for the farmer. Fresh milk quality indicators were total solid, protein, fat, pH, specific gravity and total plate count. Obtained data were analyzed descriptively. The results showed that fresh milk inbound logistics performance at KPSBU Lembang was 92.77% (above average). The added value obtained by breeders based on concentrate input amounted to Rp. 8.464 per cow with a value-added ratio of 73.83%. The quality of fresh milk during inbound logistics fulfilled national standard SNI 3141.1.2011.

Microarchitectural Exploration of STT-MRAM Last-level Cache Parameters for Energy-efficient Devices

As the technology scaling advances, limitations of traditional memories in terms of density and energy become more evident. Modern caches occupy a large part of a CPU physical size and high static leakage poses a limit to the overall efficiency of the systems, including IoT/edge devices. Several alternatives to CMOS SRAM memories have been studied during the past few decades, some of which already represent a viable replacement for different levels of the cache hierarchy. One of the most promising technologies is the spin-transfer torque magnetic RAM (STT-MRAM), due to its small basic cell design, almost absent static current and non-volatility as an added value. However, nothing comes for free, and designers will have to deal with other limitations, such as the higher latencies and dynamic energy consumption for write operations compared to reads. The goal of this work is to explore several microarchitectural parameters that may overcome some of those drawbacks when using STT-MRAM as last-level cache (LLC) in embedded devices. Such parameters include: number of cache banks, number of miss status handling registers (MSHRs) and write buffer entries, presence of hardware prefetchers. We show that an effective tuning of those parameters may virtually remove any performance loss while saving more than 60% of the LLC energy on average. The analysis is then extended comparing the energy results from calibrated technology models with data obtained with freely available tools, highlighting the importance of using accurate models for architectural exploration.

Horizons in Asymmetric Organocatalysis: En Route to the Sustainability and New Applications

Nowadays, the development of new enantioselective processes is highly relevant in chemistry due to the relevance of chiral compounds in biomedicine (mainly drugs) and in other fields, such as agrochemistry, animal feed, and flavorings. Among them, organocatalytic methods have become an efficient and sustainable alternative since List and MacMillan pioneering contributions were published in 2000. These works established the term asymmetric organocatalysis to label this area of research, which has grown exponentially over the last two decades. Since then, the scientific community has attended to the discovery of a plethora of organic reactions and transformations carried out with excellent results in terms of both reactivity and enantioselectivity. Looking back to earlier times, we can find in the literature a few examples where small organic molecules and some natural products could act as effective catalysts. However, with the birth of this type of catalysis, new chemical architectures based on amines, thioureas, squaramides, cinchona alkaloids, quaternary ammonium salts, carbenes, guanidines and phosphoric acids, among many others, have been developed. These organocatalysts have provided a broad range of activation modes that allow privileged interactions between catalysts and substrates for the preparation of compounds with high added value in an enantioselective way. Here, we briefly cover the history of this chemistry, from our point of view, including our beginnings, how the field has evolved during these years of research, and the road ahead.

Research Based Learning: Added Value in Students' Science Critical Thinking Skills

Many new learning models in the 21st century have emerged in improving students' academic skills, one of which is research-based learning (RBL). This pedagogic and constructivist model connects research and learning in improving students' critical thinking skills (CTS). The results of the study show that studies in empowering students' CTS using RBL are still limited. Therefore, exploration and deeper measurement of CTS with the RBL model were carried out through this study. The purpose of this study was to improve students' CTS using the RBL learning model. The results of the ANCOVA test showed that there was an effect of the RBL model in improving students' CTS. Descriptive data also shows that the average value of CTS is 72.70 using RBL, while students who take part in learning using conventional models show an average value of critical thinking skills of 58.30. Thus, RBL can be recommended in increasing the CTS of elementary school students in science learning.

Modeling and Simulation of Reaction Environment in Photoredox Catalysis: A Critical Review

From the pharmaceutical industry’s point of view, photoredox catalysis has emerged as a powerful tool in the field of the synthesis of added-value compounds. With this method, it is possible to excite the catalyst by the action of light, allowing electron transfer processes to occur and, consequently, oxidation and reduction reactions. Thus, in association with photoredox catalysis, microreactor technology and continuous flow chemistry also play an important role in the development of organic synthesis processes, as this technology offers high yields, high selectivity and reduced side reactions. However, there is a lack of a more detailed understanding of the photoredox catalysis process, and computational tools based on computational fluid dynamics (CFD) can be used to deal with this and boost to reach higher levels of accuracy to continue innovating in this area. In this review, a comprehensive overview of the fundamentals of photoredox catalysis is provided, including the application of this technology for the synthesis of added-value chemicals in microreactors. Moreover, the advantages of the continuous flow system in comparison with batch systems are pointed out. It was also demonstrated how modeling and simulation using computational fluid dynamics (CFD) can be critical for the design and optimization of microreactors applied to photoredox catalysis, so as to better understand the reagent interactions and the influence of light in the reaction medium. Finally, a discussion about the future prospects of photoredox reactions considering the complexity of the process is presented.

Multiple-bead assay for the differential serodiagnosis of neglected human cestodiases: Neurocysticercosis and cystic echinococcosis

Background Neurocysticercosis (NCC), and cystic echinococcosis (CE) are two neglected diseases caused by cestodes, co-endemic in many areas of the world. Imaging studies and serological tests are used in the diagnosis of both parasitic diseases, but cross-reactions may confound the results of the latter. The novel multiplex bead-based assay with recombinant antigens has been reported to increases the diagnostic accuracy of serological techniques. Methodology We set-up an immunoassay based on the multiplex bead-based platform (MBA), using the rT24H (against Cysticercus cellulosae, causing cysticercosis) and r2B2t (against Echinococcus granulosus sensu lato, causing CE) recombinant antigens, for simultaneous and differential diagnosis of these infections. The antigens were tested on 356 sera from 151 patients with CE, 126 patients with NCC, and 79 individuals negative for both diseases. Specificity was calculated including sera from healthy donors, other neurological diseases and the respective NCC or CE sera counterpart. The diagnostic accuracy of this assay was compared with two commercial ELISA tests, Novalisa and Ridascreen, widely used in the routine diagnosis of cysticercosis and CE, respectively. Main findings For the diagnosis of NCC, sensitivity ranged from 57.94–63.49% for the rT24H-MBA, and 40.48–46.03% for Novalisa ELISA depending on exclusion or inclusion of sera having equivocal results on ELISA from the analysis; specificities ranged from 90.87–91.30% and 70.43–76.96%, respectively. AUC values of the ROC curve were 0.783 (rT24H) and 0.619 (Novalisa) (p-value < 0.001). For the diagnosis of CE, the sensitivity of the r2B2t-MBA ranged from 68.87–69.77% and of Ridascreen ELISA from 50.00–57.62%; specificities from 92.47–92.68% and from 74.15–80.98%, respectively. AUC values were 0.717 and 0.760, respectively. Conclusions/Significance Overall, the recombinant antigens tested with the bead-based technology showed better diagnostic accuracy than the commercial assays, particularly for the diagnosis of NCC. The possibility of testing the same serum sample simultaneously for the presence of antibodies against both antigens is an added value particularly in seroprevalence studies for cysticercosis linked to control programs in endemic areas where these two parasites coexist.