1,319 research outputs found
Analysis of pervasive mobile ad hoc routing protocols
Pervasive computing (also referred to as ubiquitous computing or ambient intelligence) aims to create environments where computers are invisibly and seamlessly integrated and connected into our everyday environment. Pervasive computing and intelligent multimedia technologies are becoming increasingly important, although many potential applications have not yet been fully realized. These key technologies are creating a multimedia revolution that will have significant impact across a wide spectrum of consumer, business, healthcare, and governmental domains. This useful volume provides up-to-date and state-of-the-art coverage of the diverse topics related to pervasive computing and intelligent multimedia technologies. The use of different computational intelligence-based approaches to various problems in pervasive computing are examined, including video streaming, intelligent behavior modeling and control for mobile manipulators, tele-gaming, indexing video summaries for quick video browsing, web service processes, virtual environments, ambient intelligence, and prevention and detection of attacks to ubiquitous databases. Topics and features: -Includes a comprehensive overview, providing a thorough literature review and an outline of the important research challenges -Discusses pervasive computing approaches in the context of intelligent multimedia -Examines virtual reality technology, mobile virtual environments, and the potential use of intelligent multimedia and ubiquitous computing in the hotels of the future -Describes various approaches in ambient intelligence for home health care for the elderly and those suffering from Alzheimer’s disease, for volcano monitoring, and for preventing attacks to ubiquitous databases Investigates issues in web services and situation awareness in pervasive computing environments -Explores wireless network applications, such as mobile agents and e-commerce
Durable high early strength concrete via internal curing approach using saturated lightweight and recycled concrete aggregates
Master of ScienceDepartment of Civil EngineeringChristopher A. JonesEnvironmental exposure is one of the primary causes of concrete pavement deterioration, specifically cyclic freezing and thawing, as is common in Kansas. Rehabilitation of deteriorated concrete pavement is a common pavement life-extension strategy, and a variety of rehabilitation techniques are often utilized depending on the level of pavement distress. Budgetary constraints, however, often dictate use of partial and full-depth patching methods to rehabilitate deteriorated concrete pavement rather than replace an entire road. For roadways with high traffic volume, patching is often done overnight within few hours. These repairs include removing the old concrete and preparing the location for new concrete, which must achieve at least 1,800 psi compressive strength 6 hours prior to opening to traffic to avoid compromising future durability. Current patches last less than 10 years despite a nominal 20-year service life.
This study utilized an internal curing technique to produce durable high early strength concrete for patching. Because desorbing water throughout the concrete matrix improves the microstructure and reduces porosity, lightweight aggregates and crushed concrete aggregates were each used to desorb water and provide internal curing. Tests were conducted to evaluate compressive strength, autogenous shrinkage, length change, and freezing and thawing related to mass change, length change, and relative dynamic modulus of elasticity (RDME). In contrast to ASTM C157, which only measures drying shrinkage after 14 days of curing, autogenous shrinkage of concrete was measured in this study. KTMR-22, developed by the Kansas Department of Transportation, was used to evaluate freeze-thaw durability of internally cured repair mixtures because this method subjects test specimens to a much harsher test regimen than ASTM C666. For example, KTMR-22 utilizes 660 cycles that simulate 20 years of exposure to 33 cycles of freezing and thawing compared to ASTM-666 exposure of only 300 cycles. Results showed that the mixture made with lightweight aggregate and low cement content met all requirements for expansion and RDME. This mixture also had minimum autogenous shrinkage among all the mixtures
Analisis Pemilihan Pompa Untuk Shell and Tube Heat Exchanger Skala Laboratorium
Penelitian ini menganalisa tentang pemilihan pompa alat penukar kalor Shell dan Tube kapasitas Skala Laboraturium. Pompa yang digunakan dalam sistem Shell and Tube Heat exchanger ini menggukan dua jenis pompa , yaitu : pompa sentrifugal untuk distribusi air dingin dan pompa oli atau Gear Pump untuk distribusi oli panas (fluida panas).Heat Exchanger atau Alat Penukar Kalor merupakan suatu alat untuk memindahkan energi termal dari sumber panas ke sumber yang lebih dingin, atau alat yang memungkinkan terjadinya perpindahan energi kalor atau panas antara dua fluida atau lebih yang mempunyai temperatur berbeda. Oleh sebab itu perlu adanya anilisa pemilihan pompa yang tepat agar sistem beropersi dengan maksimal.Dalam perancangan ini aspek-aspek yang perlu dihitung antara lain : Menentukan kapasitas Heat Exchanger sehinnga bisa diketahui kebutuhan aliran air yang dibutuhkan untuk mendinginkan fluida panas, sehingga effisiensi dari Heat exchanger bisa mencapai nilai maksimal
CD44 Receptor Mediates Urate Crystal Phagocytosis by Macrophages and Regulates Inflammation in A Murine Peritoneal Model of Acute Gout
Gout is a chronic arthritis caused by the deposition of poorly soluble monosodium urate monohydrate (MSU) crystals in peripheral joints. Resident macrophages initiate inflammation in response to MSU mediated by NF-κB nuclear translocation and NLRP3 inflammasome activation. We investigated the role of CD44, a transmembrane receptor, in mediating MSU phagocytosis by macrophages. We used an antibody that sheds the extracellular domain (ECD) of CD44 to study the role of the receptor and its associated protein phosphatase 2A (PP2A) in macrophage activation. We also studied the significance of CD44 in mediating MSU inflammation in-vivo. Cd44−/− BMDMs showed reduced MSU phagocytosis, LDH release, IL-1β expression and production compared to Cd44+/+ BMDMs. Elevated CD44 staining was detected intracellularly and CD44 colocalized with α-tubulin as a result of MSU exposure and ECD-shedding reduced MSU phagocytosis in murine and human macrophages. Anti-CD44 antibody treatment reduced NF-κB p65 subunit nuclear levels, IL-1β expression, pro-IL-1β and IL-8 production in MSU stimulated THP-1 macrophages (p \u3c 0.01). The effect of the antibody was mediated by an enhancement in PP2A activity. CD44 ECD-shedding reduced the conversion of procaspase-1 to active caspase-1, caspase-1 activity and resultant generation of mature IL-1β in macrophages. Neutrophil and monocyte influx and upregulated production of IL-1β was evident in wildtype mice. MSU failed to trigger neutrophil and monocyte recruitment in Cd44−/− mice and lower IL-1β levels were detected in peritoneal lavages from Cd44−/− mice (p \u3c 0.01). Anti-CD44 antibody treatment reduced neutrophil and monocyte recruitment and resulted in reduced lavage IL-1β levels in the same model. CD44 plays a biologically significant role in mediating phagocytosis of MSU and downstream inflammation and is a novel target in gout treatment
Fingolimod Phosphate (FTY720-P) Activates Protein Phosphatase 2A in Human Monocytes and Inhibits Monosodium Urate Crystal-Induced Interleukin-1 β Production
Gout is a chronic inflammatory arthritis caused by monosodium urate monohydrate (MSU) crystal deposits in joints of lower limbs. Phagocytic uptake of MSU crystals by joint-resident macrophages and recruited circulating monocytes results in IL-1β expression and production. Current acute gout treatments have serious toxicities and suffer suboptimal clinical outcomes. Protein phosphatase 2A (PP2A) plays an important role in regulating signaling pathways relevant to inflammation. We hypothesized that innate immune danger signals, e.g., lipopolysaccharide (LPS) and soluble uric acid (sUA), prime human monocytes toward MSU crystal phagocytosis and that increased IL-1β production mediated by a reduction in PP2A activity and restoring PP2A activity exerts an anti-inflammatory effect in this setting. Priming monocytes with LPS + sUA increased cytosolic pro-IL-1β and mature IL-1β and enhanced MSU crystal phagocytosis and its downstream IL-1β expression (P \u3c 0.001). A combination of LPS + sUA priming and MSU crystals reduced PP2A activity in monocytes by 60% (P = 0.013). PP2A catalytic subunit gene knockdown reduced PP2A activity and exacerbated MSU crystal–induced IL-1β expression and secretion (P \u3c 0.0001). Fingolimod (FTY720) and its active metabolite, fingolimod phosphate (FTY720-P), were evaluated for their ability to activate PP2A in human monocytes over 24 hours. FTY720 and FTY720-P activated PP2A to a similar extent, and maximal enzyme activity occurred at 24 hours for FTY720 and at 6 hours for FTY720-P. FTY720-P (2.5 μM) reduced pro-IL-1β production and IL-1β secretion in primed and MSU crystal–stimulated monocytes (P \u3c 0.0001) without changing the magnitude of crystal phagocytosis. We conclude that PP2A is a promising new target in acute gout
Study of Botnets and Their Threats to Internet Security
Among all media of communications, Internet is most vulnerable to attacks owing to its public nature and virtually without centralized control. With the growing financial dealings and dependence of businesses on Internet, these attacks have even more increased. Whereas previously hackers would satisfy themselves by breaking into someone’s system, in today\u27s world hackers\u27 work under an organized crime plan to obtain illicit financial gains. Various attacks than include spamming, phishing, click fraud, distributed denial of services, hosting illegal material, key logging, etc. are being carried out by hackers using botnets. In this paper a detailed study of botnets vis-a-vis their creation, propagation, command and control techniques, communication protocols and relay mechanism is presented. The aim of this paper is to gain an insight of security threats that users of Internet are facing from hackers by the use of malicious botnets
A Practical Study of E-mail Communication through SMTP
Simple Mail Transfer Protocol (SMTP) is an application layer protocol for e-mail communication. It has been adopted as a standard by Internet Engineering Task Force (IETF). SMTP has set conversational and grammatical rules for exchanging messages between connected computers. It has evolved through several revisions and extensions since its formation by Jon Postel in 1981. In SMTP, the sender establishes a full-duplex transmission channel with a receiver. The receiver may be either the ultimate destination or an intermediate forwarding agent. SMTP commands are issued by the sender and are sent to the receiver, which responds to these commands through codes. Each SMTP session between the sender and the receiver consists of three phases namely: connection establishment, mail transactions and connection termination. This paper describes and illustrates the process of e-mail communication through SMTP by issuing the individual SMTP commands directly to transmit e-mail messages. It also describes individual SMTP commands and extensions with practical implementation using a Telnet client
Digital Library - An Inevitable Resource for Modern Day Research in Developing Countries
Research in any area requires an extensive collection and study of relevant literature. The research literature may be found in different libraries dispersed at different geographical locations. The conventional library systems pose some potential difficulties in acquiring timely information and therefore impede the research activity. This paper presents use of digital libraries in carrying out cost-effective and quality research. With technology innovations, a commensurate progress is required in the development and maintenance of the knowledge base. Statistics have shown that the research activity has increased with the digitization of the information and its easy availability to the researchers especially in developing countries. The digital library has thus become an inevitable source of information for researchers around the globe especially in developing countries to maintain the pace of research in a highly competitive world
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