1,420 research outputs found
Verifying Monadic Second-Order Properties of Graph Programs
The core challenge in a Hoare- or Dijkstra-style proof system for graph
programs is in defining a weakest liberal precondition construction with
respect to a rule and a postcondition. Previous work addressing this has
focused on assertion languages for first-order properties, which are unable to
express important global properties of graphs such as acyclicity,
connectedness, or existence of paths. In this paper, we extend the nested graph
conditions of Habel, Pennemann, and Rensink to make them equivalently
expressive to monadic second-order logic on graphs. We present a weakest
liberal precondition construction for these assertions, and demonstrate its use
in verifying non-local correctness specifications of graph programs in the
sense of Habel et al.Comment: Extended version of a paper to appear at ICGT 201
INTERFERON PRODUCTION BY MOUSE LEUKOCYTES IN VITRO AND IN VIVO
Vaccinia virus penetrates, or is phagocytosed by, mouse leukocytes in vitro. A cytotoxic effect is observed, but no new infectious virus is produced. Vaccinia virus, as infectious particles, is eliminated from a culture of leukocytes at a more rapid rate than can be accounted for by thermal inactivation. Leukocytes infected with vaccinia virus produce a substance with the properties of interferon. The evidence presented suggests that leukocytes also produce interferon in vivo and that this interferon is related to the observed protective effect on the outcome of intracerebral vesicular stomatitis virus challenge in mice. It is postulated that leukocytes, in this manner, may make a positive contribution to the host's defense mechanism and to the process of recovery from viral infections
Examination of fully automated mammographic density measures using LIBRA and breast cancer risk in a cohort of 21,000 non-Hispanic white women
BACKGROUND: Breast density is strongly associated with breast cancer risk. Fully automated quantitative density assessment methods have recently been developed that could facilitate large-scale studies, although data on associations with long-term breast cancer risk are limited. We examined LIBRA assessments and breast cancer risk and compared results to prior assessments using Cumulus, an established computer-assisted method requiring manual thresholding.
METHODS: We conducted a cohort study among 21,150 non-Hispanic white female participants of the Research Program in Genes, Environment and Health of Kaiser Permanente Northern California who were 40-74 years at enrollment, followed for up to 10 years, and had archived processed screening mammograms acquired on Hologic or General Electric full-field digital mammography (FFDM) machines and prior Cumulus density assessments available for analysis. Dense area (DA), non-dense area (NDA), and percent density (PD) were assessed using LIBRA software. Cox regression was used to estimate hazard ratios (HRs) for breast cancer associated with DA, NDA and PD modeled continuously in standard deviation (SD) increments, adjusting for age, mammogram year, body mass index, parity, first-degree family history of breast cancer, and menopausal hormone use. We also examined differences by machine type and breast view.
RESULTS: The adjusted HRs for breast cancer associated with each SD increment of DA, NDA and PD were 1.36 (95% confidence interval, 1.18-1.57), 0.85 (0.77-0.93) and 1.44 (1.26-1.66) for LIBRA and 1.44 (1.33-1.55), 0.81 (0.74-0.89) and 1.54 (1.34-1.77) for Cumulus, respectively. LIBRA results were generally similar by machine type and breast view, although associations were strongest for Hologic machines and mediolateral oblique views. Results were also similar during the first 2 years, 2-5 years and 5-10 years after the baseline mammogram.
CONCLUSION: Associations with breast cancer risk were generally similar for LIBRA and Cumulus density measures and were sustained for up to 10 years. These findings support the suitability of fully automated LIBRA assessments on processed FFDM images for large-scale research on breast density and cancer risk
Synthesis of OCL Pre-conditions for Graph Transformation Rules
Proceedings of: Third International Conference on Model Transformation (ICMT 2010): Theory and Practice of Model Transformation. Málaga, Spain, 28 June-02 July, 2010Graph transformation (GT) is being increasingly used in Model Driven Engineering (MDE) to describe in-place transformations like animations and refactorings. For its practical use, rules are often complemented with OCL application conditions. The advancement of rule post-conditions into pre-conditions is a well-known problem in GT, but current techniques do not consider OCL. In this paper we provide an approach to advance post-conditions with arbitrary OCL expressions into pre-conditions. This presents benefits for the practical use of GT in MDE, as it allows: (i) to automatically derive pre-conditions from the meta-model integrity constraints, ensuring rule correctness, (ii) to derive pre-conditions from graph constraints with OCL expressions and (iii) to check applicability of rule sequences with OCL conditions.Work funded by the Spanish Ministry of Science and Innovation through projects “Design and construction of a Conceptual Modeling Assistant” (TIN2008-00444/TIN - Grupo Consolidado), “METEORIC” (TIN2008-02081),mobility grants JC2009-00015 and PR2009-0019, and the R&D program of the Community of Madrid (S2009/TIC-1650, project “e-Madrid”).Publicad
Canonical Derivations with Negative Application Conditions
Using graph transformations to specify the dynamics of distributed systems and networks, we require a precise understanding of concurrency. Negative application conditions (NACs) are an essential means for controlling the application of rules, extending our ability to model complex systems. A classical notion of concurrency in graph transformation is based on shift equivalence and its representation by canonical derivations, i.e., normal forms of the shift operation anticipating independent steps. These concepts are lifted to graph transformation systems with NACs and it is shown that canonical derivations exist for so-called incremental NACs
SISTEM INFORMASI PELAJARAN PADA SMP YPK MERAUKE
SMP YPK Merauke adalah salah satu Lembaga Pendidikan sekolah di Kota Merauke yang sama seperti sekolah pada lainnya bertujuan untuk mengubah tingkah laku individu menuju arah yang lebih baik melalui interaksi dengan lingkungan sekitar melalui proses belajar mengajar dan dengan kondisi situasi pandemic Covid-19 proses belajar mengajar harus mengikuti protocol kesehatan yang sebelumnya waktu belajar hingga 6 jam dalam sehari atau lebih sekarang berkurang menjadi 3 jam dalam sehari serta pertemuan waktu belajar di sekolah yang sebelumnya 6 hari dalam seminggu menjadi 2 hari dalam seminggu membuat guru dan pihak sekolah mengalami kesulitan dalam proses belajar mengajar sehingga murid banyak ketinggalan materi pelajaran yang ada. Dan Informasi tugas sekolah yang terlambat diinfokan membuat murid terlambat mengerjakan dan mengumpulkan tugas. oleh sebab, itu penelitian ini bertujuan untuk dapat membantu guru dalam memberikan materi pelajaran secara online kepada murid. Metode pengumpulan data yang digunakan berupa wawancara kepada guru atau staf serta murid pada SMP YPK Merauke, setelah data terkumpul berupa data guru, data murid, maka data mata pelajaran maka dimulai pembuatan sistem. Sistem dibuat menggunakan Android studio dan untuk manajemen database menggunakan Firebase. Setelah sistem selesai dibuat maka dilakukan pengujian terhadap sistem, pengujian yang digunakan adalah metode Black-Box untuk menguji fungsi dari sistem apakah sudah sesuai dengan rancangan yang dibuat dan pengujian metode UAT (User Acceptance Testing) untuk menguji sistem apakah sudah berjalan sesuai fungsinya berdasarkan kebutuhan guru dan murid. Mengacu pada hasil pengujian sistem menggunakan Black-Box, didapatkan bahwa sistem yang dibuat dapat memfasilitasi guru dalam memberikan materi, tugas kepada murid secara online serta membantu murid dalam mengakses materi pelajaran dan tugas secara online. Berdasarkan hasil tersebut dalam pengujian UAT (User Acceptance Testing) didapatkan hasil bahwa 80% guru menyatakan sistem dapat memfasilitasi untuk memberikan materi dan tugas secara online, serta 80% murid menyatakan sistem sangat memfasilitasi dalam mengakses materi pelajaran dan tugas secara online
Graph-Based Shape Analysis Beyond Context-Freeness
We develop a shape analysis for reasoning about relational properties of data
structures. Both the concrete and the abstract domain are represented by
hypergraphs. The analysis is parameterized by user-supplied indexed graph
grammars to guide concretization and abstraction. This novel extension of
context-free graph grammars is powerful enough to model complex data structures
such as balanced binary trees with parent pointers, while preserving most
desirable properties of context-free graph grammars. One strength of our
analysis is that no artifacts apart from grammars are required from the user;
it thus offers a high degree of automation. We implemented our analysis and
successfully applied it to various programs manipulating AVL trees,
(doubly-linked) lists, and combinations of both
- …