2,407 research outputs found
YAPA: A generic tool for computing intruder knowledge
Reasoning about the knowledge of an attacker is a necessary step in many
formal analyses of security protocols. In the framework of the applied pi
calculus, as in similar languages based on equational logics, knowledge is
typically expressed by two relations: deducibility and static equivalence.
Several decision procedures have been proposed for these relations under a
variety of equational theories. However, each theory has its particular
algorithm, and none has been implemented so far. We provide a generic procedure
for deducibility and static equivalence that takes as input any convergent
rewrite system. We show that our algorithm covers most of the existing decision
procedures for convergent theories. We also provide an efficient
implementation, and compare it briefly with the tools ProVerif and KiSs
Low-latitude scintillation occurrences around the equatorial anomaly crest over Indonesia
We investigated low-latitude ionospheric scintillation in Indonesia using two
GPS receivers installed at Bandung (107.6° E, 6.9° S;
magnetic latitude 17.5° S) and Pontianak (109.3° E,
0.02° S; magnetic latitude 8.9° S). This study aimed to
characterise climatological and directional ionospheric scintillation
occurrences, which are useful not only for the physics of ionospheric
irregularities but also for practical use in GNSS (global navigation
satellite system)-based navigation. We used the deployed instrument's
amplitude scintillation (S4 index) data from 2009, 2010, and 2011; the yearly
SSN (sunspot-smoothed numbers) were 3.1, 16.5, and 55.9, respectively. In
summary, (1) scintillation occurrences in the post-sunset period
(18:00–01:00 LT) during equinox months (plasma bubble season) at the two
sites can be ascribed to the plasma bubble; (2) using directional analyses of
the two sites, we found that the distribution of scintillation occurrences is
generally concentrated between the two sites, indicating the average location
of the EIA (equatorial ionisation anomaly) crest; (3) scintillation
occurrence enhancements for the two sites in field-aligned directions are
herein reported for the first time by ground-based observation in a
low-latitude region; (4) distribution of scintillation occurrences at
Pontianak are concentrated in the southern sky, especially in the southwest
direction, which is very likely associated with the plasma bubble tilted
westward with increasing latitude; and (5) scintillation occurrence in the
post-midnight period in the non-plasma-bubble season is the most intriguing
variable occurring between the two sites (i.e. post-midnight scintillations
are observed more at Bandung than Pontianak). Most of the post-midnight
scintillations observed at Bandung are concentrated in the northern sky, with
low elevation angles. This might be due to the amplitude of
irregularities in certain directions, which may be effectively
enhanced by background density enhancement by the EIA and because
satellite–receiver paths are longer in the EIA crest region and in a
field-aligned direction
Finality of Indonesian Constitutional Court Decision in Regard to Judicial Review
This article examines the constitutional status of Constitutional Court's decisions constitutionally guaranteed as final. This status very critical because it could lead Constitutional Court to the judicial supremacy position. This article argues against this possibility. The status of Constitutional Court's decisions should be critized on the basis that its finality is prima facie, not absolute. As a solution, this article takes a position called departmentalism which means that court and legislature are not supreme in their authority to interpret the constitution.
Artikel ini membahas tentang status konstitusional putusan Mahkamah Konstitusi yang dijamin konstitusi bersifat final. Status tersebut sangat kritikal karena dapat mengarahkan Mahkamah Konstitusi ke posisi supremasi yudisial. Artikel ini berargumen tidak setuju atas kemungkinan tersebut. Oleh karena itu, status
putusan Mahkamah Konstitusi perlu dikritisi dengan dasar bahwa finalitasnya tersebut bersifat “prima facie”, tidak absolut. Sebagai solusinya, artikel ini mengambil posisi departementalisme yang memiliki pengertian bahwa pengadilan dan legislator tidak memiliki supremasi atas kewenangan untuk melakukan interpretasi konstitusi
On the statistical distribution of first--return times of balls and cylinders in chaotic systems
We study returns in dynamical systems: when a set of points, initially
populating a prescribed region, swarms around phase space according to a
deterministic rule of motion, we say that the return of the set occurs at the
earliest moment when one of these points comes back to the original region. We
describe the statistical distribution of these "first--return times" in various
settings: when phase space is composed of sequences of symbols from a finite
alphabet (with application for instance to biological problems) and when phase
space is a one and a two-dimensional manifold. Specifically, we consider
Bernoulli shifts, expanding maps of the interval and linear automorphisms of
the two dimensional torus. We derive relations linking these statistics with
Renyi entropies and Lyapunov exponents.Comment: submitted to Int. J. Bifurcations and Chao
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
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
Pengaruh Kedalaman terhadap Perkembangan Rumput Laut Kotoni Hasil Kultur Jaringan
Biotrop Bogor berhasil melakukan kultur jaringan bibit rumput laut Kotoni (Kappaphycus alvarezii) hingga skala laboratorium.Perkembangan hingga produksi masal telahberhasil dilakukan oleh BBPBL Lampung. Sebagai komoditas baru, perlu dilakukan uji coba pendahuluan. Salah satu yang telah dilakukan adalah melakukan uji coba pada tahun 2014 untuk mengetahui kedalaman terbaik terhadap perkembangan bibit rumput laut hasil kultur jaringan. Uji coba dilakukan selama VI minggu dengan menggunakan berat awal bibit yang sama yaitu 75 gram pada tiga tingkatan kedalaman perairanberbeda: 10 cm, 30 dan 50 cm. Parameter yang diamati meliputi, perkembangan tanaman, dan sintasan. Hasil pengamatan perkembangan tanaman pada kedalaman 10 cm dari minggu pertama sampai minggu ke VI berat awal 75 gr, 115,80 gr, 157,40 gr, 216,00 gr,303,00 gr, 341,00 gr dan 375,00 gr. Kedalaman 30 cm berat awal 75 gr, 118,60 gr,139,80 gr, 199,00 gr, 254 gr 293 gr dan 304 gr. Kadalaman 50 cm: berat awal 75 gr, 96,6 gr, 122,4 gr, 159 gr,207 gr, 250 gr dan 260,8 gr. Sintasan (SR) pada kedalaman 10 cm dari minggu pertama hingga minggu keempat 100 % dan pada minggu ke lima dan keenam masing-masing 98 %. SR pada kedalaman 30 cm dari minggu pertama hingga keempat 100 % dan minggu kelima dan keenam 96 %. Dan SR pada kedalaman 50 cm dari minggu pertama hingga minggu ke empat 100 % dan pada minggu ke lima 94 % dan 92 %. Berdasarkan hasil perhitungan, melakukan kegiatan produksi dapat melakukan penanaman pada kedalaman antara 10 hingga 30 cm
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