185 research outputs found

    Conditional expectation with regularization for missing data imputation

    Full text link
    Missing data frequently occurs in datasets across various domains, such as medicine, sports, and finance. In many cases, to enable proper and reliable analyses of such data, the missing values are often imputed, and it is necessary that the method used has a low root mean square error (RMSE) between the imputed and the true values. In addition, for some critical applications, it is also often a requirement that the imputation method is scalable and the logic behind the imputation is explainable, which is especially difficult for complex methods that are, for example, based on deep learning. Based on these considerations, we propose a new algorithm named "conditional Distribution-based Imputation of Missing Values with Regularization" (DIMV). DIMV operates by determining the conditional distribution of a feature that has missing entries, using the information from the fully observed features as a basis. As will be illustrated via experiments in the paper, DIMV (i) gives a low RMSE for the imputed values compared to state-of-the-art methods; (ii) fast and scalable; (iii) is explainable as coefficients in a regression model, allowing reliable and trustable analysis, makes it a suitable choice for critical domains where understanding is important such as in medical fields, finance, etc; (iv) can provide an approximated confidence region for the missing values in a given sample; (v) suitable for both small and large scale data; (vi) in many scenarios, does not require a huge number of parameters as deep learning approaches; (vii) handle multicollinearity in imputation effectively; and (viii) is robust to the normally distributed assumption that its theoretical grounds rely on

    Electrochemical DNA sensor for label-free soybean transgenic detection

    Get PDF
    This paper describes the development of electrochemical label- free DNA sensor for detection of transgenic in Round–up Ready Soybean (herbicide tolerance). Two pairs of electrodes which the optimized dimension is 70µm x 30µm (the width of electrode x inter-distance between fingers), were fabricated on a chip for differential measures. The DNA probe (35S 5’-GCT CCT ACA AAT GCC ATC A-3) was designed in such a way that it can hybridize with the CaMV 35S promoter of Roundup Ready soybean. The DNA was immobilized on the surface of the sensor by the mean of (3-aminopropyl)triethoxysilane (APTS) polymer. The response time of DNA sensor is less than 1 second; in case of 100% matching level, the sensitivity is 2 mV/µM. The activity of DNA sensor remains unchanged after 9 months of storage at -4oC in DI water. Some random soybean samples were collected, extracted and tested by the DNA sensor and the results were well matched with the of PCR method

    One-loop contributions to decays eb→eaγe_b\to e_a \gamma and (g−2)ea(g-2)_{e_a} anomalies, and Ward identity

    Full text link
    In this paper, we will present analytic formulas to express one-loop contributions to lepton flavor violating decays eb→eaγe_b\to e_a \gamma, which are also relevant to the anomalous dipole magnetic moments of charged leptons eae_a. These formulas were computed in the unitary gauge, using the well-known Passarino-Veltman notations. We also show that our results are consistent with those calculated previously in the 't Hooft-Veltman gauge, or in the limit of zero lepton masses. At the one-loop level, we show that the appearance of fermion-scalar-vector type diagrams in the unitary gauge will violate the Ward Identity relating to an external photon. As a result, the validation of the Ward Identity guarantees that the photon always couples with two identical particles in an arbitrary triple coupling vertex containing a photon.Comment: The version accepted to Nuclear Physics

    Student Satisfaction with Quality of Accounting and Auditing Education: The Case of Vietnam

    Get PDF
    This research is conducted to examine and evaluate determinants influencing the level of student satisfaction in the quality of auditing and accounting training at Vietnamese universities. Data were collected from 213 students of accounting and auditing field in three universities of National Economics University, University of Commerce and Academy of Finance. Exploratory factor analysis (EFA) and linear regression models were employed to determine the determinants influencing student satisfaction about quality of accounting and auditing. The findings show that the strongest impact on student satisfaction was the ability to serve; then training program; infrastructure component, and the last of teaching team. Based on the results, some recommendations are proposed for improving the satisfaction levels of students of accounting and auditing. Keywords: Quality of service; Quality of training; Satisfactio

    Ho Chi Minh's Thoughts On Control Of The State's Power And Lessons For Vietnam

    Get PDF
    In Vietnam, the State’s power is unified, agencies shall assign, coordinate and control each other in the exercises of the legislative, executive, and judicial powers. This is necessary to prevent abuse of power and ensure the state’s power. The Constitution 1946 was written by Ho Chi Minh (1890 -1969) and created a mechanism and foundation to control the state’s power in Vietnam. Nearly, in the Constitution 2013, the issue of controlling state power is recorded. The assignment and control are reflected in the assignment of the scope of power to each state agency. From the approach of philosophical, social philosophy, and political philosophy, through research and analysis documents in Ho Chi Minh Complete Collection; of previous researchers and policies, legal of Vietnam’s Government on control of the state's power and lessons for Vietnam today. The result shows that Ho Chi Minh’s thought on controlling power has shown the basic contents related to asserting that the power owner belongs to the people and focusing on supervision; use the Constitution to limit state power. The article also gives experiences when studying Ho Chi Minh's thoughts on state power control over Vietnam today

    A Two-Bit Reflectarray Element Using Cut-Ring Patch Coupled to Delay Lines

    Get PDF
    In this paper, a two-bit element for reflectarray applications is presented. The proposed element is based on the cut-ring patch coupled to delay lines through an annular slot. The four states of the reflection phase with a step of 90◦ are achieved with two switches. This reported work is the first step towards the 2-bit active reflectarray element. Prototypes of the element have been fabricated and characterized in X-band using waveguide simulator. Measured results show good characteristics with low magnitude losses and the bandwidth of 1.7-bit resolution is over 5%

    Preparation of Ti/TiO2-PANi electrodes by combining method of thermal treatment with polymerization processing and their electrochemical property

    Get PDF
    Ti/TiO2-PANi-electrodes were synthesized by combining method of thermal treatment of titanium substrate with chemical polymerization processing of aniline on which. Their morphological structure was observed by scanning electron microscopy. The presence of PANi and TiO2 were indicated by infrared spectra and X-ray diffraction, respectively. Their electrochemical properties were characterized by cyclic voltammetry and impedance spectroscopy. The results showed that their photoelectrochemical property with light on in 0.5 M H2SO4 indicating a n-conductor that depended on PANi thickness covered TiO2-layer among them the best one obtained by oxidative temperature of 500 oC for 30 minutes during thermal treatment of titanium substrate connected with an immersing into acidic aniline solution for only 8 min during polymerization

    Influence of alloying elements on the corrosion of fine art bronze in the strong corrosive environment

    Get PDF
    The influence of Sn, Zn, and Pb on the corrosion of fine art bronze in strong corrosive environment were investigated. The value of loss mass and the potential of the specimens were determined in the artificial sea-water environment. Corrosion of specimens was compared each to other to find the effect of the elements. The corrosion products were determined with the XRD/SEM/EDS analyses. The results shown that, Sn decreases the corrosion rate of the bronze alloy in marine environment while Zn increases it. The corrosion rates and potential curves showed that the corrosion rate of the bronzes reduced with immersion time. Alloy containing 0.7% Pb; 1.6% Zn; 9.7 % Sn; 88% Cu (in %wt.) has the corrosion rate as lowest. Keywords. Corrosion, strong corrosive environments, fine art bronze, Sn, Pb, Zn
    • …
    corecore