188 research outputs found
PEMBANGUNAN INFRASTRUKTUR MARITIM UNTUK MENDUKUNG PROGRAM TOL LAUT DALAM MEWUJUDKAN POROS MARITIM DUNIA (PMD). AUTHOR: Mithun Sinaga, D. A. Mamahit, Yusnaldi Yusnaldi
No full textPEMBANGUNAN INFRASTRUKTUR MARITIM UNTUK MENDUKUNG PROGRAM TOL LAUT DALAM MEWUJUDKAN POROS MARITIM DUNIA (PMD)
Mithun Sinaga, D. A. Mamahit, Yusnaldi Yusnald
Characterisation of cosmic ray induced noise events in AstroSat-CZT imager
No full textThe Cadmium Zinc Telluride (CZT) Imager onboard AstroSat consists of pixelated CZT detectors, which are sensitive to hard X-rays above 20 keV. The individual pixels are triggered by ionising events occurring in them, and the detectors operate in a self-triggered mode, recording each event separately with information about its time of incidence, detector co-ordinates, and channel that scales with the amount of ionisation. The detectors are sensitive not only to photons from astrophysical sources of interest, but also prone to a number of other events like background X-rays, cosmic rays, and noise in detectors or the electronics. In this work, a detailed analysis of the effect of cosmic rays on the detectors is made and it is found that cosmic rays can trigger multiple events which are closely packed in time (called ‘bunches’). Higher energy cosmic rays, however, can also generate delayed emissions, a signature previously seen in the PICsIT detector on-board INTEGRAL. An algorithm to automatically detect them based on their spatial clustering properties is presented. Residual noise events are examined using examples of Gamma Ray Bursts as target sources
A generalized event selection algorithm for AstroSat CZT imager data
No full textThe Cadmium–Zinc–Telluride (CZT) Imager on board AstroSat is a hard X-ray imaging spectrometer operating in the energy range of 20–100 keV. It also acts as an open hard X-ray monitor above 100 keV capable of detecting transient events like the Gamma-ray Bursts (GRBs). Additionally, the instrument has the sensitivity to measure hard X-ray polarization in the energy range of 100–400 keV for bright on-axis sources like Crab and Cygnus X-1 and bright GRBs. As hard X-ray instruments like CZTI are sensitive to cosmic rays in addition to X-rays, it is required to identify and remove particle induced or other noise events and select events for scientific analysis of the data. The present CZTI data analysis pipeline includes algorithms for such event selection, but they have certain limitations. They were primarily designed for the analysis of data from persistent X-ray sources where the source flux is much less than the background and thus are not best suited for sources like GRBs. Here, we re-examine the characteristics of noise events in CZTI and present a generalized event selection method that caters to the analysis of data for all types of sources. The efficacy of the new method is reviewed by examining the Poissonian behavior of the selected events and the signal to noise ratio for GRBs
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No full textData set of 821 patients to assess the sleep quality in the urban slum</p
Sub-MeV spectroscopy with AstroSat-CZT imager for gamma ray bursts
No full textCadmium–Zinc–Telluride Imager (CZTI) onboard AstroSat has been a prolific Gamma-Ray Burst (GRB) monitor. While the 2-pixel Compton scattered events (100–300 keV) are used to extract sensitive spectroscopic information, the inclusion of the low-gain pixels (∼ 20% of the detector plane) after careful calibration extends the energy range of Compton energy spectra to 600 keV. The new feature also allows single-pixel spectroscopy of the GRBs to the sub-MeV range which is otherwise limited to 150 keV. We also introduced a new noise rejection algorithm in the analysis (‘Compton noise’). These new additions not only enhances the spectroscopic sensitivity of CZTI, but the sub-MeV spectroscopy will also allow proper characterization of the GRBs not detected by Fermi. This article describes the methodology of single, Compton event and veto spectroscopy in 100–900 keV combined for the GRBs detected in the first year of operation. CZTI in last five years has detected ∼ 20 bright GRBs. The new methodologies, when applied on the spectral analysis for this large sample of GRBs, has the potential to improve the results significantly and help in better understanding the prompt emission mechanism
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Voice Constructions in Kanakanavu Grammar and Discourse
No full textThis dissertation is a comprehensive analysis of voice constructions in Kanakanavu, a critically endangered Formosan language (Austronesian language of Taiwan) spoken in the Namasia District of Kaohsiung, southern Taiwan. The data considered for the analysis are mainly drawn from a corpus of spontaneous speech produced by contemporary speakers, which are complemented by elicited data and a verb database constructed by the author. The Kanakanavu voice system has been treated in various previous studies, but there is a general lack of consensus regarding several of its fundamental properties. The language has been analyzed as exhibiting a two-way, three-way or even four-way/Philippine-type voice distinction; it also remains unclear how voice interacts with tense-aspect-mood marking on the one hand, and transitivity and grammatical relations on the other. By investigating the morphosyntactic, semantic and discourse-pragmatic properties of voice, this dissertation (i) establishes a framework for describing and representing Kanakanavu natural discourse data, (ii) analyzes the morphological and syntactic foundations of Kanakanavu voice and (iii) explores the functional-typological implications of Kanakanavu voice constructions both within and beyond the Austronesian language family.It is argued that Kanakanavu exhibits a binary voice distinction in its verbal-clause morphosyntax.The structural opposition --- between what are labelled "agent voice" and "patient voice" --- is evidenced in two specific patterns of interaction between voice marking and tense-aspect-mood marking: while agent-voice verbs always involve separate exponents for voice and tense-aspect-mood, patient-voice verbs are consistently marked by voice markers that also serve a tense-aspect-marking or mood-marking function. The finding regarding the number of voice distinctions is in line with those found in some recent analyses of Kanakanavu voice, but it is motivated by typologically informed analyses of verbal tense-aspect-mood marking in the language based on detailed examinations of how different verb forms are used in spontaneous speech.At the syntactic level, voice alternation in Kanakanavu is argued to be essentially a transitivity-alternation phenomenon, leading to the analysis of the agent-voice construction as the intransitive construction (involving only one core argument), and the patient-voice construction as the transitive construction (involving two core arguments). The analysis is based on the observation from natural discourse that the patient-voice construction is always used for expressing transitive situations, while the agent-voice construction is the default construction for forming (i) basic intransitive clauses and (ii) clauses involving syntactically demoted and discourse-functionally backgrounded patients. The finding suggests that the Kanakanavu verbal clause exhibits ergativity, which is in line with many analyses of Formosan and Philippine languages where voice interacts closely with transitivity. It is, however, further shown that Kanakanavu exhibits differential (pronominal) agent marking in its patient-voice construction. This is a typologically and areally unusual phenomenon within the larger Western Austronesian context, which has been generally overlooked in previous studies on the language despite having been identified early on by Tsuchida (1976)
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