7,071 research outputs found
Quad-band internal mobile phone antenna
A novel internal, quad-band antenna placed inside a ‘foldable’ type of Mobile Phone is presented. Its structure consists of a helical and a monopole element exciting two broad frequency bands. Using a simple matching circuit the proposed antenna covers several frequency bands including the Global System for Mobile Communication (890-960 MHz), Digital Communication System (1710-1880 MHz), Personal Communication System (1850-1990 MHz) and Universal Mobile Telecommunication System (1920-2170 MHz). It achieves a Voltage Standing Wave Ratio (VSWR) of less than three across all frequency bands with total radiation efficiency of more than 50%. Its novel design and structure occupies only 1.8 cm3 of volume making this antenna very small and very suitable for internal use inside mobile terminals
Methods of space radiation dose analysis with applications to manned space systems
The full potential of state-of-the-art space radiation dose analysis for manned missions has not been exploited. Point doses have been overemphasized, and the critical dose to the bone marrow has been only crudely approximated, despite the existence of detailed man models and computer codes for dose integration in complex geometries. The method presented makes it practical to account for the geometrical detail of the astronaut as well as the vehicle. Discussed are the major assumptions involved and the concept of applying the results of detailed proton dose analysis to the real-time interpretation of on-board dosimetric measurements
A Personalized System for Conversational Recommendations
Searching for and making decisions about information is becoming increasingly
difficult as the amount of information and number of choices increases.
Recommendation systems help users find items of interest of a particular type,
such as movies or restaurants, but are still somewhat awkward to use. Our
solution is to take advantage of the complementary strengths of personalized
recommendation systems and dialogue systems, creating personalized aides. We
present a system -- the Adaptive Place Advisor -- that treats item selection as
an interactive, conversational process, with the program inquiring about item
attributes and the user responding. Individual, long-term user preferences are
unobtrusively obtained in the course of normal recommendation dialogues and
used to direct future conversations with the same user. We present a novel user
model that influences both item search and the questions asked during a
conversation. We demonstrate the effectiveness of our system in significantly
reducing the time and number of interactions required to find a satisfactory
item, as compared to a control group of users interacting with a non-adaptive
version of the system
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Discovering qualitative empirical laws
In this paper we describe GLAUBER, an AI system that models the scientific discovery of qualitative empirical laws. We have tested the system on data from the history of early chemistry, and it has rediscovered such concepts as acids, alkalis, and salts, as well as laws relating these concepts. After discussing GLAUBER we examine the program's relation to other discovery systems, particularly methods for conceptual clustering and language acquisition
Expression of the neural cell adhesion molecule NCAM in endocrine cells
We examined the expression of the neural cell adhesion molecule NCAM in a number of endocrine tissues of adult rat and in an endocrine tumor cell line. NCAM was found by immunoelectron microscopy to be present on the surface of all endocrine cells in the three lobes of the hypophysis, although staining was relatively less intense in the intermediate lobe, and in pancreatic islets. Pituicytes, hypophyseal glial cells, were also labeled for NCAM. A rat insulinoma cell line (RIN A2) also expressed NCAM as judged by immunocytochemistry. Analysis of NCAM antigenic determinants (Mr 180, 140, and 120 KD) revealed large variations in the relative proportions of NCAM polypeptides present in the different tissues. Although all tissues and cell lines expressed NCAM-140, NCAM-180 was not detected in the adenohypophysis, pancreas, or adrenal medulla, and NCAM-120 was found in none of the endocrine tissues or cell lines except at low levels in the neurohypophysis. The tumor cell line expressed significant levels of NCAM-180, which was most abundant in the neurohypophysis. These results show that NCAM expression appears to be a general property of endocrine cells, although the antigenic composition differs markedly from that in brain tissue. These data are discussed with regard to the embryological origins of the different endocrine tissues, and possible functional implications are suggested
Fictions of Belonging: New Arrival Literature and Contemporary Discourse on U.S. Immigration
In the past two decades, “New Arrival Literature” has generated wide acclaim and a rich body of literary criticism. This genre of literature, written by immigrants who have themselves migrated, is becoming increasingly popular in a time of dominant currents of anti-immigration sentiment. My thesis explores this genre of fiction in the context of contemporary debates on immigration in the United States. In particular, this paper looks at three dominant myths about U.S. immigrants— that they drain the economy, are unwilling to assimilate, and bring crime. The novels in my study— Americanah (2013) by Chimamanda Ngozi Adichie, We Need New Names (2013) by NoViolet Bulawayo, Claire of the Sea Light (2013) by Edwidge Danticat, The Brief Wondrous Life of Oscar Wao (2008) by Junot Díaz, The Girl in the Tangerine Scarf (2009) by Mohja Kahf, and The Namesake (2003) by Jhumpa Lahiri— offer more holistic narratives about immigration and supplement material facts about its impact on the United States. Placing these novels in their socio-historical contexts, I explore the diverse immigrant experience and restore complexity to the oversimplified debate. My thesis also reveals how reductive, anti-immigrant stereotypes are part of the broader myth of “American Exceptionalism.” These authors, through their lived experiences and works of fiction, counter these myths by offering more human and complex narratives of migration
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