1,879 research outputs found

    Numerical Fitting-based Likelihood Calculation to Speed up the Particle Filter

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    The likelihood calculation of a vast number of particles is the computational bottleneck for the particle filter in applications where the observation information is rich. For fast computing the likelihood of particles, a numerical fitting approach is proposed to construct the Likelihood Probability Density Function (Li-PDF) by using a comparably small number of so-called fulcrums. The likelihood of particles is thereby analytically inferred, explicitly or implicitly, based on the Li-PDF instead of directly computed by utilizing the observation, which can significantly reduce the computation and enables real time filtering. The proposed approach guarantees the estimation quality when an appropriate fitting function and properly distributed fulcrums are used. The details for construction of the fitting function and fulcrums are addressed respectively in detail. In particular, to deal with multivariate fitting, the nonparametric kernel density estimator is presented which is flexible and convenient for implicit Li-PDF implementation. Simulation comparison with a variety of existing approaches on a benchmark 1-dimensional model and multi-dimensional robot localization and visual tracking demonstrate the validity of our approach.Comment: 42 pages, 17 figures, 4 tables and 1 appendix. This paper is a draft/preprint of one paper submitted to the IEEE Transaction

    Parity and Risk of Low Birth Weight Infant in Full Term Pregnancy

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    Latar belakang: Berat badan lahir rendah meningkatkan morbiditas dan mortalitas pada bayi baru lahir. Hasil Riskesdas 2010 dan 2013 menunjukkan penurunan angka prevalensi berat badan lahir rendah dari 11,1% menjadi 10,2%. Tujuan penelitian ini adalah mengidentifikasi faktor risiko yang berkaitan dengan kejadian berat badan lahir rendah pada kehamilan cukup bulan. Metode: Penelitian potong lintang di dua rumah sakit di Jakarta dengan menggunakan data sekunder. Data rekam medik wanita yang melahirkan pada periode 1 Januari sampai 31 Desember 2011 dipilih secara purposif. Berat badan lahir rendah adalah berat badan kurang dari 2500g pada bayi baru lahir. Analisis data dilakukan dengan menggunakan regresi logistik. Hasil: Pada analisis ini didapatkan 2242 subyek yang memenuhi kriteria, dari 4191 subyek. Proporsi berat badan lahir rendah adalah 9,5%. Jika dibandingkan dengan primipara, wanita nullipara memiliki risiko melahirkan bayi dengan berat badan lahir rendah 46% lebih tinggi [adjusted odds ratio (ORa) = 1.46; P=0.030]. Selanjutnya, jika dibandingkan dengan bayi laki-laki, bayi perempuan memiliki risiko 42% lebih tinggi mengalami berat lahir rendah (ORa = 1.42; P=0.017) Kesimpulan: Bayi berat badan lahir rendah pada kehamilan cukup bulan lebih sering ditemukan pada wanita nullipara dan bayi perempuan. Kata kunci: paritas, jenis kelamin bayi, berat badan lahir rendahBackground: Low birth weight infants tend to increase the occurence of early infant mortality and morbidity. The survey in Indonesia suggested that the prevalence of low birth weight declined from 11.1% in 2010 to 10.2% in 2013. This study aims to identify the risk factors of low birth weight infant in full term pregnancy. Methods: This was a cross-sectional study using secondary data from two hospitals in Jakarta. The data was obtained from medical records of pregnant women who gave birth during the period of January 1 to December 31, 2011. Multivariat logistic regression model with stepwise method was used to analyze the risks of low birth weight. Results: The sample size in this study was 4191 subjects. Out of them 2242 subjects met the inclusion criteria. The proportion of low birth weight was 9.5%. Compared with primipara, nullipara had 46 % increased risk to have LBW infant (ORa = 1.46; P=0.030), meanwhile primipara and nullipara did not have significant difference for having LBW infants (ORa = 0.90; P=0.614). In term of sex of infants, female infant had 42% higher risk of having LBW infant compared with male infant (ORa = 1.42; P=0.017). Conclusion : Low birth weight infants in full term pregnancies are more common in nullipara and most of the LBW infants are femal

    Brief Report of an Artificial Rearing Method for Paragus quadri-fasciatus Meigen

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    The four-striped small syrphid fly, Paragus quadri-fasciatus Meigen, is one important kind of natural enemy of aphids. Since 1983 we have studied the utilization of this natural enemy. We selected perennial grasses (of two to three years life span), which host aphids. In the first year we planted the above-mentioned grasses and in the second year we raised the syrphid fly. Details of the method are described as follows.Originating text in Chinese.Citation: Gao, Junfeng, Zhang, Li, Zhang, Shubin, Qin, Bo. (1992). Brief Report of an Artificial Rearing Method for Paragus quadri-fasciatus Meigen. Natural Enemies of Insects, 14(4), 188-190

    Temperature Dependence Calibration and Correction of the DAMPE BGO Electromagnetic Calorimeter

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    A BGO electromagnetic calorimeter (ECAL) is built for the DArk Matter Particle Explorer (DAMPE) mission. The effect of temperature on the BGO ECAL was investigated with a thermal vacuum experiment. The light output of a BGO crystal depends on temperature significantly. The temperature coefficient of each BGO crystal bar has been calibrated, and a correction method is also presented in this paper

    Quantum Coherence Effects in Four-level Diamond Atomic System

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    A symmetric four-level closed-loop \diamondsuit type (the diamond structure) atomic system driven by four coherent optical fields is investigated. The system shows rich quantum interference and coherence features. When symmetry of the system is broken, interesting phenomena such as single and double dark resonances appear. As a result, the double electromagnetically induced transparency effect is generated, which will facilitate the implementation of quantum phase gate operation.Comment: 8pages, 19 figure
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