150 research outputs found
OBSAPS data acquisition system : operator's manual and system overview
On the Ocean Bottom Seismometer Augmentation to the Philippine Sea Experiment
(OBSAPS, April-May, 2011, R/V Revelle), a VLA and six OBSs were deployed to listen to
an active acoustic source, a J15-3. This report describes the hardware and software used to
control and record the acoustic transmissions from the source. Some significant features of
the system are: 1) The system transmits general user-defined source functions, such as Msequences
(.SIO files). 2) In addition to controlling the source waveform, the system also
records six real-time channels in binary files with user-selectable lengths: the monitor
hydrophone mounted near the source, the power amplifier voltage and current, the depth of
the source, sonobuoy data (when deployed) and an IRIG-B time reference. Files are output
in .AUV format with a precision GPS-based time stamp in the file name. 3) The
transmission start time along with ADC and DAC sample rates are disciplined to GPS time.
4) A convenient, Labview based, user interface provides real-time source control and
monitoring. 5) The software provides parsing and logging of gyro and GPS NMEA
sentences. The system, which was based on an earlier system from Scripps MPL, worked
well on OBSAPS and is available for future projects.Funding was provided by the Office of Naval Research under Contract Nos. N00014-10-1-0994
and N00014-10-1-0987
OBSANP data acquisition system : operator's manual and system overview
On the Ocean Bottom Seismometer Augmentation in the North Pacific Experiment (OBSANP,
June-July, 2013, R/V Melville), a VLA and twelve OBSs were deployed to listen to an active
acoustic source, a J15-3. This report describes the hardware and software used to control and
record the acoustic transmissions from the source. Some significant features of the system are:
1) The system transmits general user-defined source functions, such as M-sequences (.SIO files).
2) In addition to controlling the source waveform, the system also records six real-time channels
in binary files with user-selectable lengths: the monitor hydrophone mounted near the source, the
power amplifier voltage and current, the depth of the source, Vref signal driving the power
amplifiers and an IRIG-B time reference. Files are output in .AUV format with a precision GPSbased
time stamp in the file name. 3) The transmission start time along with ADC and DAC
sample rates are disciplined to GPS time. 4) A convenient, Labview based, user interface
provides real-time source control and monitoring. 5) The software provides parsing and logging
of gyro and GPS NMEA sentences. The system, which was based on an earlier system from
Scripps MPL, worked well on OBSANP and is available for future projects.Funding was provided by the Office of Naval Research
under contract N00014-10-1-0987 and N00014-10-1-0510
Operator precedence for data-dependent grammars
Constructing parsers based on declarative specification of operator precedence is a very old research topic, and there are various existing approaches. However, these approaches are either tied to a particular parsing technique, or cannot deal with all corner cases found in programming languages. In this paper we present an implementation of declarative specification of operator precedence for general parsing that (1) is independent of the underlying parsing algorithm, (2) does not require any grammar transformation that increases the size of the grammar, (3) preserves the shape of parse trees of the original, natural grammar, and (4) can deal with intricate cases of operator precedence found in functional programming languages such as OCaml. Our new approach to operator precedence is formulated using data-dependent grammars, which extend context-free grammars with arbitrary computation, variable binding and constraints. We implemented our approach using Iguana, a data-dependent parsing framework, and evaluated it by parsing Java and OCaml source files. The results show that our approach is practical for parsing programming languages with complicated operator precedence rules
The Impact of Business Intelligence Systems on Profitability and Risks of Firms
202105 bcvcAccepted ManuscriptRGC155009/15BEarly releas
Ocean Bottom Seismometer Augmentation of the Philippine Sea Experiment (OBSAPS) cruise report
The Ocean Bottom Seismometer Augmentation to the Philippine Sea Experiment
(OBSAPS, April-May, 2011, R/V Revelle) addresses the coherence and depth dependence of
deep-water ambient noise and signals. During the 2004 NPAL Experiment in the North Pacific
Ocean, in addition to predicted ocean acoustic arrivals and deep shadow zone arrivals, we
observed "deep seafloor arrivals" that were dominant on the seafloor Ocean Bottom Seismometer
(OBS) (at about 5000m depth) but were absent or very weak on the Distributed Vertical Line
Array (DVLA) (above 4250m depth). These "deep seafloor arrivals" (DSFA) are a new class of
arrivals in ocean acoustics possibly associated with seafloor interface waves. The OBSAPS
cruise had three major research goals: a) identification and analysis of DSFAs occurring at short
(1/2CZ) ranges in the 50 to 400Hz band, b) analysis of deep sea ambient noise in the band 0.03
to 80Hz, and c) analysis of the frequency dependence of BR and SRBR paths as a function of
frequency. On OBSAPS we deployed a fifteen element VLA from 12 to 852m above the
seafloor, four short-period OBSs and two long-period OBSs and carried out an 11.5day
transmission program using a J15-3 acoustic source.Funding was provided by the Office of Naval Research under Contract Nos. N00014-10-1-0994
and N00014-10-1-0987
18th Annual Conference on Legal Issues for Financial Institutions
Materials from the 18th Annual Conference on Legal Issues for Financial Institutions held by UK/CLE in 1998
Compositional Satisfiability Solving in Separation Logic
We introduce a novel decision procedure to the satisfiability problem in array separation logic combined with general inductively defined predicates and arithmetic. Our proposal differentiates itself from existing works by solving satisfiability through compositional reasoning. First, following Fermatās method of infinite descent, it infers for every inductive definition a ābaseā that precisely characterises the satisfiability. It then utilises the base to derive such a base for any formula where these inductive predicates reside in. Especially, we identify an expressive decidable fragment for the compositionality. We have implemented the proposal in a tool and evaluated it over challenging problems. The experimental results show that the compositional satisfiability solving is efficient and our tool is effective and efficient when compared with existing solvers
Dermatofibrosarcoma protuberans treated by micrographic surgery
Dermatofibrosarcoma protuberans is an uncommon cutaneous tumour which rarely metastasises. However, local recurrence following apparently adequate surgical excision is well recognised, presumably as a result of sub-clinical contiguous growth, for which micrographically controlled excision would be a logical treatment. A retrospective study of all patients treated by micrographic surgery, from April 1995āMarch 2000, at a tertiary skin oncology centre. Twenty-one patients (11 males), age 14 to 71 years with dermatofibrosarcoma protuberans on the trunk (10 patients), groin (four), head and neck (four), and limbs (three) were treated. In 15 patients one micrographic layer cleared the tumour, and four were cleared with two layers. For one patient the second stage was completed by conventional excision guided by positive margins. Another patient with a multiply recurrent perineal dermatofibrosarcoma protuberans, not cleared in one area after two layers, died from a pulmonary embolus before total clearance could be achieved. There was no correlation between tumour size and lateral excision margin. No recurrence was observed during the follow-up, from 21 to 80 months, median 47 months. The study provides further support for micrographic surgery as the treatment of choice for dermatofibrosarcoma protuberans
Extreme Weather and Civil War in Somalia: Does Drought Fuel Conflict through Livestock Price Shocks?
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