27 research outputs found
Performability Modeling And Analysis Of Fault Tolerance Support In Communication Protocols
No full textThere has been much research in assessing the performance of different messaging systems, but often messaging systems cannot be completely expressed by performance metrics alone. For an emerging class of large-scale distributed servers, robustness is at least as as important as performance. Three factors make protocol robustness critical: (i) these servers have very high availability requirements (e.g., minutes of down-time per year), implying that even occasional message loss cannot be catastrophic; (ii) intra-server communication depends on external client service demands, making it extremely difficult to exert enough control over the system "by design'' to avoid message loss; and (iii) many commodity LANs do not implement sufficient hardware flow control to always prevent loss inside the network under arbitrarily adverse communication patterns. Most of the current paradigms of reliable communication either provide strong consistency semantics with high overhead (e.g. transactional RPC) or reliability with indeterminate failure states using retransmissions(e.g.,TCP/IP).
This work aims at building a new messaging layer that provides additional recovery states for applications to allow designers to reason about the cause of the error and to build customized recovery mechanisms. We present the design and implementation of a high performance Active Message (AM) layer over the Virtual Interface Architecture (VIA) library as such a messaging infrastructure. Its performance is evaluated to ensure that the additional recovery states are achieved at a reasonable overhead. We then present a queuing model to allow in the analysis and evaluation of robustness of this messaging protocol by computing its performance as a function of dependability in the presence of component and overall failures.Technical report DCS-TR-42
The concept of divinity in Malay cosmology
No full textThe Malay World has undergone several formative experiences in interacting with nature, the latest of which is influenced mostly by the Islamic civilization. In tandem with these changes, the view the Malays acquired in engaging with the cosmos is fundamentally shaped by their theological belief. In this paper, the author attempts to elucidate their concept of divinity, which is based on their theology, to the extent that it shapes their views about the cosmos
The epistemology of values and sustainability
No full textScience is a problem solving activity. Based on the assumption that science begins with problems, the process of macro creativity is outlined. Solutions created are preceded by intention and action. Out of the macro creative process, the dynamics of having a sustainable science, namely, the Cycle of Sustainability, is formulated. It is within this Cycle of Sustainability that innovation, i.e. the endless possibilities of micro creativity by way of mathematics is further examined as a subset of the macro creative process. It is argued that essentially the root of sustainability in science lies in having sustainable problems. Moreover, the author attempts to epistemologically argue on two issues of scientific realism: (i) the distinction between the observables and non-observables, and (ii) whether scientific claims are either true or false
Wenn Macht und Dichtung sich begegnen : Polykrates und Anakreon im Lichte der griechischen Literatur
No full textThe main aim o f the article is to present the preserved literary tradition about connections
between the Samian tyrant Polycrates and the poet Anakreon. The literary tradition is
analyzed chronologically: from Herodotus to Himerius. The author makes an attempt to present
various traditions (which are partially independent form H erodotus) concerning the tyrant and th
Detection of magnesium ion concentration using fiber coupler based displacement sensor with concave mirror target
No full textHypothetical Protein BPSL3393 of Burkholderia pseudomallei is Involved in Ethanolamine Catabolism
No full textBurkholderia pseudomallei adalah bakterium kediaman tanah yang menyebabkan
penyakit muncul secara global yang dikenali sebagai melioidosis. Dianggarkan satu pertiga
daripada gen siliko di dalam genom dikelaskan sebagai gen hipotesis. Kumpulan gen ini
sukar untuk dicirikan secara fungsional, sebahagiannya disebabkan oleh ketiadaan fenotip
yang ketara di bawah tetapan makmal konvensional. Kajian bioinformatik gen hipotetikal
menunjukkan gen yang ditetapkan sebagai BPSL3393 yang menguraikan protein kecil
11 kDA dengan domain mengikat CoA. BPSL3393 dipelihara dalam semua genom
B. pseudomallei serta pelbagai spesies lain dalam genus Burkholderia. Dengan mengambil
kira bahawa CoA memainkan peranan metabolik di mana-mana dalam semua bentuk
kehidupan, pencirian BPSL3393 mungkin mendedahkan ciri metabolik B. Pseudomallei
yang sebelum ini terlepas pandang. Gen ini dipadamkan dari genom menggunakan
pendekatan penggabungan semula homolog berganda yang menghasilkan mutan null.
Mutan BPSL3393 tidak menunjukkan perbezaan kadar pertumbuhan dengan jenis yang
liar di bawah keadaan pertumbuhan yang kaya dan minima. Ujian fenotip metabolik
yang meluas dilakukan dengan melibatkan 95 substrat metabolik. Pemotongan mutan
BPSL3393 teruk terjejas dalam metabolisme etanolaminanya. Kadar pertumbuhan mutan
itu dilemahkan apabila etanolamina digunakan sebagai sumber karbon tunggal. Analisis
transkrip gen metabolisme etanolamina menunjukkan bahawa mereka telah dikawal
dalam mutan BPSL3393. Ini seolah-olah menunjukkan bahawa fungsi BPSL3393 sebagai
pengawal selia positif untuk metabolisme etanolamina
Lampes céramiques signées
No full textThis work, which summarises the author’s doctoral dissertation, presents an original approach to the study of lamps from the Early Roman Empire. Using a method more often applied to the study of samian pottery, the author has carried out a systematic analysis of the associations of signature, form and decoration. The purpose of the study was to verify a hypothesis, that characteristic types could be associated with a spécifie potter’s signature, and, at the same time, to identify actual workshops. The research is successful not only in demonstrating the existence of significant connections between several potters, but also in questioning the uncritical use, still frequently made, of chronoiogical typologies. The author argues for setting up reference corpora of makers stamps and decorative marks and for cataloguing characteristic forms, thus enabling the lamp to play a significant rôle in the archaeological evidence, as well as bringing to light a new craft
