• Title/Summary/Keyword: Data Gap

Search Result 2,014, Processing Time 0.025 seconds

Gap Junction Contributions to the Goldfish Electroretinogram at the Photopic Illumination Level

  • Kim, Doh-Yeon;Jung, Chang-Sub
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.16 no.3
    • /
    • pp.219-224
    • /
    • 2012
  • Understanding how the b-wave of the electroretinogram (ERG) is generated by full-field light stimulation is still a challenge in visual neuroscience. To understand more about the origin of the b-wave, we studied the contributions of gap junctions to the ERG b-wave. Many types of retinal neurons are connected to similar and different neighboring neurons through gap junctions. The photopic (cone-dominated) ERG, stimulated by a small light beam, was recorded from goldfish (Carassius auratus) using a corneal electrode. Data were obtained before and after intravitreal injection of agents into the eye under a photopic illumination level. Several agents were used to affect gap junctions, such as dopamine D1 and D2 receptor agonists and antagonists, a nitric oxide (NO) donor, a nitric oxide synthase (NOS) inhibitor, the gap junction blocker meclofenamic acid (MFA), and mixtures of these agents. The ERG b-waves, which were enhanced by MFA, sodium nitroprusside (SNP), SKF 38393, and sulpiride, remained following application of a further injection of a mixture with MFA. The ERG b-waves decreased following $N^G$-nitro-L-arginine methyl ester (L-NAME), SCH 23390, and quinpirole administration but were enhanced by further injection of a mixture with MFA. These results indicate that gap junction activity influences b-waves of the ERG related to NO and dopamine actions.

Components Constituting the Audit Expectation Gap: The Vietnamese Case

  • DANG, Tuan Anh;NGUYEN, Dung Khanh Ngoc
    • The Journal of Asian Finance, Economics and Business
    • /
    • v.8 no.1
    • /
    • pp.363-373
    • /
    • 2021
  • The present study seeks to investigate the degree of awareness that constitutes the audit gap expectations (AEG) to determine which audit responsibilities can be narrowed or even eliminated. The author had surveyed a sample comprising four groups including auditors, auditees, the financial community, and other interest groups. In this survey, 1400 questionnaires were sent to the respondents, and the total number of responses was 454. The collected data was processed using statistical software SPSS, version 22. The Chi-Square test was used to analyze the effect of professional differences on AEG. The results of this study indicate that AEG cannot be eliminated due to the occupational impact of each survey group (about 46%), but it can be narrowed down to 54%, including a reduction of 11% in the knowledge gap (lack of public knowledge), 13% in the reasonable expectations gap (unqualified audit quality), 30% in the deficient standards gap (limited auditing standards). These results could be attained by improving training, communicating, and adding more responsibilities. This is the first study that provides another method of measuring the contribution of the knowledge gap through professional differences and professional gaps that make up each of the AEG's components.

A point-scale gap filling of the flux-tower data using the artificial neural network (인공신경망 기법을 이용한 청미천 유역 Flux tower 결측치 보정)

  • Jeon, Hyunho;Baik, Jongjin;Lee, Seulchan;Choi, Minha
    • Journal of Korea Water Resources Association
    • /
    • v.53 no.11
    • /
    • pp.929-938
    • /
    • 2020
  • In this study, we estimated missing evapotranspiration (ET) data at a eddy-covariance flux tower in the Cheongmicheon farmland site using the Artificial Neural Network (ANN). The ANN showed excellent performance in numerical analysis and is expanding in various fields. To evaluate the performance the ANN-based gap-filling, ET was calculated using the existing gap-filling methods of Mean Diagnostic Variation (MDV) and Food and Aggregation Organization Penman-Monteith (FAO-PM). Then ET was evaluated by time series method and statistical analysis (coefficient of determination, index of agreement (IOA), root mean squared error (RMSE) and mean absolute error (MAE). For the validation of each gap-filling model, we used 30 minutes of data in 2015. Of the 121 missing values, the ANN method showed the best performance by supplementing 70, 53 and 84 missing values, respectively, in the order of MDV, FAO-PM, and ANN methods. Analysis of the coefficient of determination (MDV, FAO-PM, and ANN methods followed by 0.673, 0.784, and 0.841, respectively.) and the IOA (The MDV, FAO-PM, and ANN methods followed by 0.899, 0.890, and 0.951 respectively.) indicated that, all three methods were highly correlated and considered to be fully utilized, and among them, ANN models showed the highest performance and suitability. Based on this study, it could be used more appropriately in the study of gap-filling method of flux tower data using machine learning method.

Improving International Access to the IARC Monographs Database with Linkage to other Sources of Information

  • Rice, Jerry M.;Waters, Michael D.;Wright, R.Glenn
    • Toxicological Research
    • /
    • v.17
    • /
    • pp.227-236
    • /
    • 2001
  • The IARC Monographs Programme on the Evaluation of Carcinogenic Risks to Humans has reviewed, summarized and evaluated 869 environmental agents and exposures as oj June 2000. This large collection includes all relevant published epidemiological data on cancer in exposed humans and results of bioassays for carcinogenicity in experimental animals. Since 1986. cancer data have been systematically supplemented by summaries of other toxicological data that are relevant to assessments of carcinogenic hazard. These include summaries qf genetic and related effects of chemicals. which have been prepared as Genetic Activity Profiles (GAP) by the U.S. EPA in collaboration with IARC. As the Mono-graphs have proved increasingly valuable and influential worldwide. they have evolved into an encyclopedia on environmental carcinogenic risks to humans. However. the Monographs have historically been prepared only as printed books with limited distribution. and the Monographs Programme has needed to adjust to expectations oj wider availability. Since 1998 the evaluations and summaries have been globally accessible by Internet from IARC (http://www.iarc.fr) and the GAP profiles by Internet from EPA (http://www.epa.gov/gapdb/). with the two web sites linked. Improved EPN/ARC GAP database and software. GAP2000. now link GAP profiles directly to the appropriate IARC web pages for summaries of evaluations of a given compound and its overall IARC classification. During the year 2000. by means of optical character recognition (OCR) technology the entire series of IARC Monographs is being converted to an electronic version. The first edition is now available commercially in CD-ROM format and will soon become available on-line at .

  • PDF

Evaluation of different approaches for using a laser scanner in digitization of dental impressions

  • Lee, Wan-Sun;Kim, Woong-Chul;Kim, Hae-Young;Kim, Wook-Tae;Kim, Ji-Hwan
    • The Journal of Advanced Prosthodontics
    • /
    • v.6 no.1
    • /
    • pp.22-29
    • /
    • 2014
  • PURPOSE. This study aimed to investigate the potential clinical application of digitized silicone rubber impressions by comparing the accuracy of zirconia 3-unit fixed partial dentures (FPDs) fabricated from 2 types of data (working model and impression) obtained from a laser scanner. MATERIALS AND METHODS. Ten working models and impressions were prepared with epoxy resin and vinyl polysiloxane, respectively. Based on the data obtained from the laser scanner (D-700; 3Shape A/S, Copenhagen, Denmark), a total of 20 zirconia frameworks were prepared using a dental CAD/CAM system (DentalDesigner; 3shape A/S, Copenhagen, Denmark / Ener-mill, Dentaim, Seoul, Korea). The silicone replicas were sectioned into four pieces to evaluate the framework fit. The replicas were imaged using a digital microscope, and the fit of the reference points (P1, P2, P3, P4, P5, P6, and P7) were measured using the program in the device. Measured discrepancies were divided into 5 categories of gaps (MG, CG, AWG, AOTG, OG). Data were analyzed with Student's t-test ($\alpha$=0.05), repeated measures ANOVA and two-way ANOVA (${\alpha}=0.05$). RESULTS. The mean gap of the zirconia framework prepared from the working models presented a narrower discrepancy than the frameworks fabricated from the impression bodies. The mean of the total gap in premolars (P=.003) and molars (P=.002) exhibited a statistical difference between two groups. CONCLUSION. The mean gap dimensions of each category showed statistically significant difference. Nonetheless, the digitized impression bodies obtained with a laser scanner were applicable to clinical settings, considering the clinically acceptable marginal fit ($120{\mu}m$).

Pulsar Polar Cap and Slot Gap Models: Confronting Fermi Data

  • Harding, Alice K.
    • Journal of Astronomy and Space Sciences
    • /
    • v.30 no.3
    • /
    • pp.145-152
    • /
    • 2013
  • Rotation-powered pulsars are excellent laboratories for studying particle acceleration as well as fundamental physics of strong gravity, strong magnetic fields and relativity. Particle acceleration and high-energy emission from the polar caps is expected to occur in connection with electron-positron pair cascades. I will review acceleration and gamma-ray emission from the pulsar polar cap and associated slot gap. Predictions of these models can be tested with the data set on pulsars collected by the Large Area Telescope on the Fermi Gamma-Ray Telescope over the last four years, using both detailed light curve fitting, population synthesis and phase-resolved spectroscopy.

Reversible Data Hiding Scheme Based on Maximum Histogram Gap of Image Blocks

  • Arabzadeh, Mohammad;Rahimi, Mohammad Reza
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.6 no.8
    • /
    • pp.1964-1981
    • /
    • 2012
  • In this paper a reversible data hiding scheme based on histogram shifting of host image blocks is presented. This method attempts to use full available capacity for data embedding by dividing the image into non-overlapping blocks. Applying histogram shifting to each block requires that extra information to be saved as overhead data for each block. This extra information (overhead or bookkeeping information) is used in order to extract payload and recover the block to its original state. A method to eliminate the need for this extra information is also introduced. This method uses maximum gap that exists between histogram bins for finding the value of pixels that was used for embedding in sender side. Experimental results show that the proposed method provides higher embedding capacity than the original reversible data hiding based on histogram shifting method and its improved versions in the current literature while it maintains the quality of marked image at an acceptable level.

Class Specific Autoencoders Enhance Sample Diversity

  • Kumar, Teerath;Park, Jinbae;Ali, Muhammad Salman;Uddin, AFM Shahab;Bae, Sung-Ho
    • Journal of Broadcast Engineering
    • /
    • v.26 no.7
    • /
    • pp.844-854
    • /
    • 2021
  • Semi-supervised learning (SSL) and few-shot learning (FSL) have shown impressive performance even then the volume of labeled data is very limited. However, SSL and FSL can encounter a significant performance degradation if the diversity gap between the labeled and unlabeled data is high. To reduce this diversity gap, we propose a novel scheme that relies on an autoencoder for generating pseudo examples. Specifically, the autoencoder is trained on a specific class using the available labeled data and the decoder of the trained autoencoder is then used to generate N samples of that specific class based on N random noise, sampled from a standard normal distribution. The above process is repeated for all the classes. Consequently, the generated data reduces the diversity gap and enhances the model performance. Extensive experiments on MNIST and FashionMNIST datasets for SSL and FSL verify the effectiveness of the proposed approach in terms of classification accuracy and robustness against adversarial attacks.

Experimental Study on the Dynamic Behaviour of Oil Seals (오일시일의 동적거동에 관한 실험적 연구)

  • 김청균;심우전
    • Tribology and Lubricants
    • /
    • v.11 no.3
    • /
    • pp.54-58
    • /
    • 1995
  • This paper deals with an experimental study on the dynamic behaviour of rubber oil seals when the interferences between the shaft and the seal lip as well as the dynamic eccentricities are present. The micro-separation of the sealing gap was observed with the aid of an image processing apparatus. The temperature of the seal lip edge, friction torque and the dynamic sealing gap profile are experimentally investigated for the initial interference and the shaft eccentricity. The data was simultaneously measured under the operation conditions. Experimental results show that, as the shaft speed is increased, the leakage of sealed fluids is increasing for a certain range of shaft speeds. The test data indicates that the shaft eccentricity clearly produces the gap separation between the shaft and the seal lip which is unable to follow the radial displacement of shaft as the shaft speed increases.