Rejection-Cascade of Gaussians: Real-time adaptive background subtraction framework

Background-Foreground classification is a well-studied problem in computer vision. Due to the pixel-wise nature of modeling and processing in the algorithm, it is usually difficult to satisfy real-time constraints. There is a trade-off between the speed (because of model complexity) and accuracy. Inspired by the rejection cascade of Viola-Jones classifier, we decompose the Gaussian Mixture Model (GMM) into an adaptive cascade of Gaussians(CoG). We achieve a good improvement in speed without compromising the accuracy with respect to the baseline GMM model. We demonstrate a speed-up factor of 4-5x and 17 percent average improvement in accuracy over Wallflowers surveillance datasets. The CoG is then demonstrated to over the latent space representation of images of a convolutional variational autoencoder(VAE). We provide initial results over CDW-2014 dataset, which could speed up background subtraction for deep architectures.Comment: Accepted for National Conference on Computer Vision, Pattern Recognition, Image Processing and Graphics (NCVPRIPG 2019

Cost-effectiveness of diagnostic laparoscopy for assessing resectability in pancreatic and periampullary cancer.

Surgical resection is the only curative treatment for pancreatic and periampullary cancer, but many patients undergo unnecessary laparotomy because tumours can be understaged by computerised tomography (CT). A recent Cochrane review found diagnostic laparoscopy can decrease unnecessary laparotomy. We compared the cost-effectiveness of diagnostic laparoscopy prior to laparotomy versus direct laparotomy in patients with pancreatic and periampullary cancer with resectable disease based on CT scanning

Cost-Effectiveness Analysis of Endoscopic Ultrasound versus Magnetic Resonance Cholangiopancreatography in Patients with Suspected Common Bile Duct Stones.

Patients with suspected common bile duct (CBD) stones are often diagnosed using endoscopic retrograde cholangiopancreatography (ERCP), an invasive procedure with risk of significant complications. Using endoscopic ultrasound (EUS) or Magnetic Resonance CholangioPancreatography (MRCP) first to detect CBD stones can reduce the risk of unnecessary procedures, cut complications and may save costs

Knowledge about the research and ethics committee at Makerere University, Kampala

Background: All research involving human participants should be reviewed by a competent and independent institutional research and ethics committee. Research conducted at Makerere University College of Health Sciences should be subjected to a rigorous review process by the ethics committee in order to protect human participants’ interests, rights and welfare.Objective: To evaluate researchers’ knowledge about the functions and ethical review process of the College of Health Sciences research and ethics committee.Methods: A cross sectional study. 135 researchers consented to participate in the study, but 70 questionnaires were answered giving a 52% response.Results: Age ranged between 30 to 61 years, majority of participants 30-39 years. Most of the respondents do agree that the REC functions include Protocol review 86%, protection of research participants 84.3%, and monitoring of ongoing research. During ethical review, the RECpays special attention to scientific design [79.7%] and ethical issues [75.3%], but less to the budget and literature review. More than 97% of the respondents believe that the REC is either average or very good, while 2.8% rank it below average.Conclusion: Respondents knew the major functions of the committee including protection of the rights and welfare of research participants, protocol review and monitoring of on going research, and the elements of protocol review that are given more attention include ;scientific design and ethical issues. Overall performance of the REC was ranked as average by respondents. The committee should limit delays in approval and effectively handle all functions of the committee.African Health Sciences 2013; 13(4): 1041 - 104

Atomistic studies of transformation pathways and energetics in plutonium

One of the most challenging problems in understanding the structural phase transformations in Pu is to determine the energetically favored, continuous atomic pathways from one crystal symmetry to another. This problem involves enumerating candidate pathways and studying their energetics to garner insight into instabilities and energy barriers. The purpose of this work is to investigate the energetics of two transformation pathways for the delta to alpha' transformation in Pu that were recently proposed [Lookman et al., Phys. Rev. Lett. 100:145504, 2008] on the basis of symmetry. These pathways require the presence of either an intermediate hexagonal closed-packed (hcp) structure or a simple hexagonal (sh) structure. A subgroup of the parent fcc and the intermediate hexagonal structure, which has trigonal symmetry, facilitates the transformation to the intermediate hcp or sh structure. Phonons then break the translational symmetry from the intermediate hcp or sh structure to the final monoclinic symmetry of the alpha' structure. We perform simulations using the modified embedded atom method (MEAM) for Pu to investigate these candidate pathways. Our main conclusion is that the path via hcp is energetically favored and the volume change for both pathways essentially occurs in the second step of the transformation, i.e. from the intermediate sh or hcp to the monoclinic structure. Our work also highlights the deficiency of the current state-of-the-art MEAM potential in capturing the anisotropy associated with the lower symmetry monoclinic structure.Comment: 12 pages, 5 figures, accepted for publication in Philos. Ma

C IV BAL disappearance in a large SDSS QSO sample

Broad absorption lines (BALs) in the spectra of quasi-stellar objects (QSOs) originate from outflowing winds along our line of sight; winds are thought to originate from the inner regions of the QSO accretion disk, close to the central supermassive black hole (SMBH). Winds likely play a role in galaxy evolution and aid the accretion mechanism onto the SMBH. BAL equivalent widths can change on typical timescales from months to years; such variability is generally attributed to changes in the covering factor and/or in the ionization level of the gas. We investigate BAL variability, focusing on BAL disappearance. We analyze multi-epoch spectra of more than 1500 QSOs -the largest sample ever used for such a study- observed by different programs from the Sloan Digital Sky Survey-I/II/III (SDSS), and search for disappearing C IV BALs. The spectra rest-frame time baseline ranges from 0.28 to 4.9 yr; the source redshifts range from 1.68 to 4.27. We detect 73 disappearing BALs in the spectra of 67 sources. This corresponds to 3.9% of disappearing BALs, and 5.1% of our BAL QSOs exhibit at least one disappearing BAL. We estimate the average lifetime of a BAL along our line of sight (~ 80-100 yr), which appears consistent with the accretion disk orbital time at distances where winds are thought to originate. We inspect properties of the disappearing BALs and compare them to the properties of our main sample. We also investigate the existence of a correlation in the variability of multiple troughs in the same spectrum, and find it persistent at large velocity offsets between BAL pairs, suggesting that a mechanism extending on a global scale is necessary to explain the phenomenon. We select a more reliable sample of disappearing BALs following Filiz Ak et al. (2012), where a subset of our sample was analyzed, and compare the findings from the two works, obtaining generally consistent results.Comment: 22 pages, 9 figures. Accepted for publication in A&

Pengaruh Penggunaan Media Video Youtube APHD Channel Terhadap Kemampuan Menulis Teks Berita Pada Siswa Kelas VIII Swasta Hkbp Sidikalang Tahun Pembelajaran 2022/2023

The success of an education can be achieved with a fun level of learning using media that is able to develop students' learning intentions. This study aims to find out how influential YouTube Video Media is on the Ability to Write News Texts in Grade VIII Students of SMP HKBP Sidikalang in the 2022/2023 Academic Year. This study used a population of 60 and a sample of 30 students in each grade VIII of SMP HKBP Sidikalang in the 2022/2023 academic year. The method used in this study is the quantitative method or also called the discovery method, which determines and analyzes data concretely or empirically, objectively, measurably, rationally and systematically by describing events in the two variables studied. In accordance with this quantitative method which seeks to present data in an ongoing study. Calculation of the hypothesis in this study was tested with the "t" test at a significant level a = 0.05. From the calculated data tcount > table, namely 4.8 > 2.0. Therefore, the null hypothesis (H₂) is rejected and the alternative hypothesis (H₂) is accepted. Thus, it can be concluded that there is an influence of YouTube video media on the ability to write news text in class VIII students of SMP HKBP Sidikalang in the 2022/2023 academic year

Optimal Design of Robust Combinatorial Mechanisms for Substitutable Goods

In this paper we consider multidimensional mechanism design problem for selling discrete substitutable items to a group of buyers. Previous work on this problem mostly focus on stochastic description of valuations used by the seller. However, in certain applications, no prior information regarding buyers' preferences is known. To address this issue, we consider uncertain valuations and formulate the problem in a robust optimization framework: the objective is to minimize the maximum regret. For a special case of revenue-maximizing pricing problem we present a solution method based on mixed-integer linear programming formulation