Analysis of Galaxy Formation with Hydrodynamics

We present a hydrodynamical code based on the Smooth Particle Hydrodynamics technique implemented in an AP3M code aimed at solving the hydrodynamical and gravitational equations in a cosmological frame. We analyze the ability of the code to reproduce standard tests and perform numerical simulations to study the formation of galaxies in a typical region of a CDM model. These numerical simulations include gas and dark matter particles and take into account physical processes such as shock waves, radiative cooling, and a simplified model of star formation. Several observed properties of normal galaxies such as $M_{gas}/M_{total}$ ratios, the luminosity function and the Tully-Fisher relation are analyzed within the limits imposed by numerical resolution.Comment: 21 pages, 2 postscript tables. Submitted MNRAS 04.03.9

Pilot Metal Workload in Flight Operation: a Case Study of Indonesian Civilian Pilot

This type of activity or work with high stress level and requires more concentration and attention, in this case is the aircraft operation. Thereby mental workload is the most dominant than the physical workload. And this is what should have been a concern, because if mental workload endured by pilot is excessive, it will lower down the quality of work and lead to work safety; in this case the aircraft operation. Subjective Workload Assessment Technique (SWAT) method is used to measure mental workload value, this method consists of three dimensions with their levels, there are: time, mental effort, and psychological stress load. The aim of this study was to know the mental workload of the pilot of an aircraft in flight dimensions: phases of time, phase of flight, terrain condition, and weather, and identifies what factors the most dominant for build of mental workload. The results of studies showed that pilot mental workload will increase when a pilot faced with flight conditions do at early morning (00.00-05:59 am), during weekend and enters the peak season period, and the aircraft will be landing procedures, and also in case of change of wind conditions in flight, and will increasingly when pilot exposed to aircraft operating with route condition which has a land surface is mountainious. This study also showed that the time dimension factor (T) significantly affects the mental workload of pilots, indicating that they put more emphasis on this factor when they are considering workloads

Sharp error terms for return time statistics under mixing conditions

We describe the statistics of repetition times of a string of symbols in a stochastic process. Denote by T(A) the time elapsed until the process spells the finite string A and by S(A) the number of consecutive repetitions of A. We prove that, if the length of the string grows unbondedly, (1) the distribution of T(A), when the process starts with A, is well aproximated by a certain mixture of the point measure at the origin and an exponential law, and (2) S(A) is approximately geometrically distributed. We provide sharp error terms for each of these approximations. The errors we obtain are point-wise and allow to get also approximations for all the moments of T(A) and S(A). To obtain (1) we assume that the process is phi-mixing while to obtain (2) we assume the convergence of certain contidional probabilities

Formal Verification of Security Protocol Implementations: A Survey

Automated formal verification of security protocols has been mostly focused on analyzing high-level abstract models which, however, are significantly different from real protocol implementations written in programming languages. Recently, some researchers have started investigating techniques that bring automated formal proofs closer to real implementations. This paper surveys these attempts, focusing on approaches that target the application code that implements protocol logic, rather than the libraries that implement cryptography. According to these approaches, libraries are assumed to correctly implement some models. The aim is to derive formal proofs that, under this assumption, give assurance about the application code that implements the protocol logic. The two main approaches of model extraction and code generation are presented, along with the main techniques adopted for each approac

A reduced semantics for deciding trace equivalence using constraint systems

Many privacy-type properties of security protocols can be modelled using trace equivalence properties in suitable process algebras. It has been shown that such properties can be decided for interesting classes of finite processes (i.e., without replication) by means of symbolic execution and constraint solving. However, this does not suffice to obtain practical tools. Current prototypes suffer from a classical combinatorial explosion problem caused by the exploration of many interleavings in the behaviour of processes. M\"odersheim et al. have tackled this problem for reachability properties using partial order reduction techniques. We revisit their work, generalize it and adapt it for equivalence checking. We obtain an optimization in the form of a reduced symbolic semantics that eliminates redundant interleavings on the fly.Comment: Accepted for publication at POST'1

Interactive exploration of population scale pharmacoepidemiology datasets

Population-scale drug prescription data linked with adverse drug reaction (ADR) data supports the fitting of models large enough to detect drug use and ADR patterns that are not detectable using traditional methods on smaller datasets. However, detecting ADR patterns in large datasets requires tools for scalable data processing, machine learning for data analysis, and interactive visualization. To our knowledge no existing pharmacoepidemiology tool supports all three requirements. We have therefore created a tool for interactive exploration of patterns in prescription datasets with millions of samples. We use Spark to preprocess the data for machine learning and for analyses using SQL queries. We have implemented models in Keras and the scikit-learn framework. The model results are visualized and interpreted using live Python coding in Jupyter. We apply our tool to explore a 384 million prescription data set from the Norwegian Prescription Database combined with a 62 million prescriptions for elders that were hospitalized. We preprocess the data in two minutes, train models in seconds, and plot the results in milliseconds. Our results show the power of combining computational power, short computation times, and ease of use for analysis of population scale pharmacoepidemiology datasets. The code is open source and available at: https://github.com/uit-hdl/norpd_prescription_analyse

Bactericide ATM's keyboard intelligent systems

زمینه و هدف: آلوده بودن صفحه کلید دستگاه های خودپرداز بانکی و مراجعه فراوان کاربران به آن ها، باعث انتقال باکتری ها به انسان می شود. بنابراین از بین بردن این باکتری ها نقش مهمی در سلامتی انسان دارد. این مطالعه با هدف معرفی و ارزیابی یک سیستم هوشمند باکتری زدایی از صفحه کلید دستگاه های خودپرداز انجام شد. روش بررسی: در این مطالعه تجربی یک سیستم هوشمند ساخته شد که بر اساس خاصیت باکتری کشی پرتوهای فرابنفش عمل می کند. قبل از ارزیابی سیستم هوشمند، نمونه برداری از صفحه کلیدها انجام و تعداد باکتری اشریشیا کلی به عنوان گروه شاهد در نظر گرفته شد. قابلیت فعال شدن خودکار سیستم (پرتودهی یا قطع پرتودهی) بر اساس تعداد مراجعه کاربران، گذشت زمان و قطع تابش در زمان مراجعه کاربر بررسی شد. پس از تابش به مدت 5، 10، 15 و 20 ثانیه از فاصله 10 سانتی متری به صفحه کلید آلوده، مجدداً نمونه برداری صورت گرفت و پس از کشت باکتری ها، شمارش انجام و تعداد باکتری اشریشیا کلی با گروه شاهد مقایسه شد. یافته ها: بررسی عملکردهای مختلف سیستم نشان داد که پرتودهی (یا قطع پرتودهی) بر اساس موارد تعریف شده برای آن، به صورت خودکار انجام می شود. آزمایش های باکتریولوژیکی نشان داد که با تابش پرتو، تعداد باکتری ها به کمتر از یک درصد می رسد و در همه موارد تعداد باکتری زنده مانده با گروه شاهد تفاوت معنی داری نشان می دهد (05/0>P). نتیجه گیری: یکی از روش های مرسوم کاهش آلودگی از صفحه کلید دستگاه های خودپرداز تمیز نمودن دوره ای آن ها با مواد ضد عفونی کننده است که در دراز مدت روشی پرهزینه می باشد. سیستم هوشمند طراحی شده در مطالعه حاضر راهکار مناسبی برای کاهش آلودگی از صفحه کلید این دستگاه ها می باشد

Prochlo: Strong Privacy for Analytics in the Crowd

The large-scale monitoring of computer users' software activities has become commonplace, e.g., for application telemetry, error reporting, or demographic profiling. This paper describes a principled systems architecture---Encode, Shuffle, Analyze (ESA)---for performing such monitoring with high utility while also protecting user privacy. The ESA design, and its Prochlo implementation, are informed by our practical experiences with an existing, large deployment of privacy-preserving software monitoring. (cont.; see the paper