34 research outputs found

    Information Loss in the Human Auditory System

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    From the eardrum to the auditory cortex, where acoustic stimuli are decoded, there are several stages of auditory processing and transmission where information may potentially get lost. In this paper, we aim at quantifying the information loss in the human auditory system by using information theoretic tools. To do so, we consider a speech communication model, where words are uttered and sent through a noisy channel, and then received and processed by a human listener. We define a notion of information loss that is related to the human word recognition rate. To assess the word recognition rate of humans, we conduct a closed-vocabulary intelligibility test. We derive upper and lower bounds on the information loss. Simulations reveal that the bounds are tight and we observe that the information loss in the human auditory system increases as the signal to noise ratio (SNR) decreases. Our framework also allows us to study whether humans are optimal in terms of speech perception in a noisy environment. Towards that end, we derive optimal classifiers and compare the human and machine performance in terms of information loss and word recognition rate. We observe a higher information loss and lower word recognition rate for humans compared to the optimal classifiers. In fact, depending on the SNR, the machine classifier may outperform humans by as much as 8 dB. This implies that for the speech-in-stationary-noise setup considered here, the human auditory system is sub-optimal for recognizing noisy words

    The relationship between corporate governance and earnings management in banks listed on Tehran Stock Exchange

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    This study, in order to provide evidence about the effectiveness of corporate governance tools (content management stock ownership, institutional ownership and the percentage of non-duty members of the Board of Directors) on earnings management in banks was listed on Tehran Stock Exchange during 2009-2013.The sample consisted of 10 banks (all banks listed) were selected as sample data obtained through library research and application of new outcomes were collected. In this study, three variables of management stock ownership, institutional ownership and the percentage of non-duty members of the Board of Directors as independent variables used tools of corporate governance. Also, to measure earnings management the modified Jones model and to test hypotheses of multivariate regression was used and significance was determined using t and F statistics. Finally, it was determined that between three characteristics of corporate governance (institutional ownership percentage of share ownership required for managers and other members of the board) and there was no profit management. Keywords: Earnings management, institutional ownership percentage of share ownership management, the percentage of non-duty members of the Board of Directors

    A Novel Method for Frequency Estimation Considering Instrument Transient Effect

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    Large disturbances in power systems cause deviation in the frequency from the nominal value. Since the frequency is an important factor in the electrical network parameter measurements, it can cause malfunction of the protection system. In addition, Because of decaying DC and oscillatory components that introduced by CCVT in response of voltage variation during the fault occurrence, cause changes in the value of received voltage of primary side of CCVT. An improved least square method for estimating frequency is presented in this paper. In order to reduce the effect of this transient component, phasor estimation method has been improved by using the least square technique and utilizing knowledge of CCVT design. The capability of the proposed method was verified by several case studies generating signals in PSCAD/EMTDC. The results show the accuracy, speed and capability of the proposed metho

    A Secure-Coordinated Expansion Planning of Generation and Transmission Using Game Theory and Minimum Singular Value

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    In this paper a novel method have been proposed for expansion planning of generation and transmission that considered static security of the system such as voltage security margin And loadability limit. In the same study of expansion planning Security constraints of the system are neglected. In this study at the first step minimum singular value technique is used to evaluate voltage security margin and loadabolity limit, in order to select best bus for load incrimination. After it, in order to Supply the load, coordinated expansion planning of generation and transmission is needed, therefor the strategic interaction between transmission company (TransCo) and generation company (GenCo) for Transmission expansion planning (TEP) and generation expansion planning (GEP) in a competitive electricity market is proposed using Game Theory (GT).DOI:http://dx.doi.org/10.11591/ijece.v4i6.668

    Effects of Syringic Acid on Apoptosis, Inflammation, and AKT/mTOR Signaling Pathway in Gastric Cancer Cells

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    Gastric cancer is one of the most common cancer and deadly disease worldwide. Despite substantial advances made in the treatment of gastric cancer, existing therapies still encounter bottlenecks. Chemotherapy, for instance, could lead to serious side effects, high drug resistance and treatment failure. Phytochemical-derived compounds from plants offer novel strategies as potent drug molecules in cancer therapy. Given the low toxicity and higher tolerance rate of naturally occurring compounds, the present study evaluated the effects of syringic acid on cytotoxicity, oxidative stress, mitochondrial membrane potential, apoptosis, and inflammatory responses in gastric cancer cell line (AGS). AGS cells were treated with various concentrations (5–40 μg/mL) of syringic acid for 24 h, after which cytotoxicity was analyzed. Reactive Oxygen Species (ROS), antioxidant enzyme activities, mitochondrial membrane potential (MMP, Δψm), cell morphologies, the expression of apoptotic markers and protein expression patterns were also investigated. Results indicated that syringic acid-treated cells developed anti-cancer activities by losing MMP, cell viability, and enhancing intracellular ROS. Syringic acid selectively developed apoptosis in a dose-dependent manner via enhanced regulation of caspase-3, caspase-9 and Poly ADP-ribose Polymerase (PARP) whereas decreasing the expression levels of p53 and BCL-2. Syringic acid also lowered activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) whereas Thio Barbituric Acid Reactive Substances (TBARS) increased. Syringic acid suppressed gastric cancer cell proliferation, inflammation, and induced apoptosis by upregulating mTOR via AKT signaling pathway. The study suggests syringic acid may constitute a promising chemotherapeutic candidate for gastric cancer treatment. Our study is the first report on the anti-cancer effects of syringic acid against gastric cancer cells via apoptosis, inhibition of inflammation, and the suppression of the mTOR/AKT signaling pathway

    Cellular and subcellular interactions of graphene-based materials with cancerous and non-cancerous cells

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    Despite significant advances in early detection and personalized treatment, cancer is still among the leading causes of death globally. One of the possible anticancer approaches that is presently receiving a lot of attention is the development of nanocarriers capable of specific and efficient delivery of anticancer drugs. Graphene-based materials are promising nanocarriers in this respect, due to their high drug loading capacity and biocompatibility. In this review, we present an overview on the interactions of graphene-based materials with normal mammalian cells at the molecular level as well as cellular and subcellular levels, including plasma membrane, cytoskeleton, and membrane-bound organelles such as lysosomes, mitochondria, nucleus, endoplasmic reticulum, and peroxisome. In parallel, we assemble the knowledge about the interactions of graphene-based materials with cancerous cells, that are considered as the potential applications of these materials for cancer therapy including metastasis treatment, targeted drug delivery, and differentiation to non-cancer stem cells. We highlight the influence of key parameters, such as the size and surface chemistry of graphene-based materials that govern the efficiency of internalization and biocompatibility of these particles in vitro and in vivo. Finally, this review aims to correlate the key parameters of graphene-based nanomaterials specially graphene oxide, such as size and surface modifications, to their interactions with the cancerous and non-cancerous cells for designing and engineering them for bio-applications and especially for therapeutic purposes

    Heracleum persicum Essential Oil Nanoemulsion: A Nanocarrier System for the Delivery of Promising Anticancer and Antioxidant Bioactive Agents

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    Essential oils are important compounds for the prevention and/or treatment of various diseases in which solubility and bio-accessibility can be improved by nanoemulsion systems. Heracleum persicum oil nanoemulsion (HAE-NE) was prepared and biological properties were investigated against human breast cancer cells and normal human fibroblasts foreskin. Particle size, zeta potential and poly dispersity index were 153 nm, −47.9 mV and 0.35, respectively. (E)anethole (57.9%), terpinolene (13.8%), G-terpinene (8.1%), myrcene (6.8%), hexyl butyrate (5.2%), octyl bu-tanoate (4.5%) and octyl acetate (3.7%) was detected in nanoemulsion. Proliferation of cancer cells at IC50 = 2.32 \ub5g/mL was significantly (p < 0.05) inhibited, and cell migration occurred at 1.5 \ub5L/mL. The HAE-NE at 1.5, 2.5 and 3.5 \ub5g/concentration up-regulated caspase 3 and enhanced sub-G1 peak of cell cycle with nil cytotoxic effects in the liver, kidney and jejunum of mice. Villus height, villus width, crypt depth and goblet cells in mice group fed with 10 and 20 mg/kg body weight of HAE-NE improved. Cellular redox state in the liver indicated 10 and 20 mg/kg body weight of nanoemulsion significantly up-regulated the expression of SOD, CAT and GPx genes. Heracleum persicum oil na-noemulsion could be an eco-friendly nanotherapeutic option for pharmaceutical, cosmetological and food applications

    A Novel method to estimate Economic Replacing Time of Transformer Using Monte Carlo Algorithm and ANN

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    A hybrid method for developing a more principled approach is presented to determine the life expectancy of transformers. The approach is constructed on an economic analysis of the transformers operational characteristics in combination  with the technical issues incorporated in the decision process. In this method, firstly life time of transformer is estimated using a hybrid method based on Monte Carlo algorithm and artificial neural network. Also Pareto distribution function is applied to consider health history of transformer and uncertainty in DP behavior of transformer. In the next step, a method is proposed in order to estimate economic replacement time of transformer. This method is based on the well-known bathtub failure model, containing repairs and scheduled maintenance, in order to achieve at a more economically aim  replacing decision. This aim is obtained in part by considering the uncertainty intrinsic in transformer failures and the corresponding discontinuations in power. In essence, this method organizes a decision support system for determination the life expectancy of a transformer. Simulation results show the high accuracy and functionality of the proposed approach in estimating economic replacing time of the Transformer

    Modeling of glutamic acid production by Lactobacillus plantarum MNZ

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    Background: L-glutamic acid, the principal excitatory neurotransmitter in the brain and an important intermediate in metabolism acts as a precursor of \u3b3-amino butyric acid (GABA). In the present study, culture condition for enhanced glutamic acid production by Lactobacillus plantarum MNZ was optimized and the influence of such conditions on GABA production was evaluated. Results: Results indicated that glutamic acid increased up to 3-fold (3.35) under the following condition: pH 4.5, temperature 37\ub0C, 12% (w/v) glucose and 0.7% (w/v) ammonium nitrate; whilst GABA production was enhanced up to 10-fold under the following condition: pH 4.5, temperature 37oC, 6% (w/v) glucose and 0.7% (w/v) ammonium nitrate. Conclusions: This is the first report for dual biosynthesizing activities of a lactic acid bacterium for the production of glutamic acid and GABA. The results of this study can be further used for developing functional foods rich inglutamic acid and subsequently GABA as a bioactive compound
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