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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Enhancing Efficiency of Beaconing in VANETs

Feng, Yuhui 11 August 2016 (has links)
No description available.
12

AUTOMATED HEALTH OPERATIONS FOR THE SAPPHIRE SPACECRAFT

Swartwout, Michael A., Kitts, Christopher A. 10 1900 (has links)
International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Stanford’s Space Systems Development Laboratory is developing methods for automated spacecraft health operations. Such operations greatly reduce the need for ground-space communication links and full-time operators. However, new questions emerge about how to supply operators with the spacecraft information that is no longer available. One solution is to introduce a low-bandwidth health beacon and to develop new approaches in on-board summarization of health data for telemetering. This paper reviews the development of beacon operations and data summary, describes the implementation of beacon-based health management on board SAPPHIRE, and explains the mission operations response to health emergencies. Additional information is provided on the role of SSDL’s academic partners in developing a worldwide network of beacon receiving stations.
13

ALCATEL TELEMETRY TRANSMITTER AND BEACON TRANSMITTER (NEW GENERATION)

Tonello, E., Monica, G. Della 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / Presentation for ITC 98 of Alcatel Espace last studies and developments regarding TTC Products This document lays on 3 parts: · a technical point of view · a technology/design description · a synthesis showing main performance and results
14

Paleoenvironmental Interpretations of the Lower Taylor Group, Olympus Range area, southern Victoria Land, Antarctica

Gilmer, Greer Jessie January 2008 (has links)
The Devonian Taylor Group, in the Olympus Range area, southern Victoria Land (SVL), Antarctica, is separated from the basement by a regional nonconformity (Kukri Erosion Surface). A second localized unconformity within the Taylor Group called the Heimdall Erosion Surface separates the New Mountain Sandstone and older units from the younger Altar Mountain Formation. The depositional environment of the New Mountain Sandstone has long been under contention. The New Mountain Sandstone Formation is a predominantly quartzose cross-bedded sandstone. Its newly defined Mt Jason Member is a coarse arkosic small scale cross-bedded pebbly sandstone that grades up section into the rest of the quartzose New Mountain Sandstone with large scale cross beds. The New Mountain Sandstone has been divided into five lithofacies including the Basal Conglomerate Lithofacies, Pebbly Sandstone Lithofacies, Granule Cross-bedded Lithofacies, Pinstripe Cross-bedded Lithofacies and Cross-bedded Sandstone Lithofacies. Deposition was in a shoreface environment with minor coastal aeolian deposition. The environment changed from upper shoreface to lower shoreface up section, forming transgressive to highstand systems tracts. The Heimdall Erosion Surface truncates the Cross-bedded Sandstone Lithofacies and the Pinstripe Cross-bedded Lithofacies and was formed due to relative sea level fall leading to exposure and erosion of underlying sedimentary and basement rocks. It forms a type 1 sequence boundary. The New Mountain Sandstone was partially or totally lithified before erosion as shown by the jagged morphology of the eroded cross beds on the surface. It is not known when cementation of the NMS took place or how much of the formation has been eroded. The Heimdall Erosion Surface and Kukri Erosion Surface converge locally due to erosion on the Heimdall Erosion Surface and relief on the Kukri Erosion Surface. The Heimdall Erosion Surface became a shore platform and the site of deposition as relative sea level rose. The Altar Mountain Formation with its Odin Member is a cross-bedded, massive and bedded feldspathic and quartzose sandstone that fines up section and is deposited on the erosion surface. The Altar Mountain Formation is divided into four lithofacies including the Conglomerate Lithofacies, Trough Cross-bedded Lithofacies, Cross-bedded Bioturbated Lithofacies and Bedded Fine Lithofacies. Deposition was in a shoreface environment, changing up section to an inner shelf environment with minor estuarine/tidal influence near the top of the section forming transgressive to highstand to regressive system tracts. The sedimentary rocks are derived mainly from the Granite Harbour Intrusives and Koettlitz Group, which underlie the sandstones, but were exposed elsewhere in SVL. The sandstone clasts within the Conglomerate Lithofacies could be derived from underlying older Taylor Group rocks or exotic sources from outside the field area. Correlation with data from adjacent areas suggests deposition of the New Mountain Sandstone occurred in a shallow sea that existed from the Olympus Range, southwards into the Asgard Range and included Vashka Crag. The area around Sponsors Peak and to the north was exposed and supplying feldspathic and quartzose sediment and pebbles into the depositional basin. As relative sea level fell due to either tectonic uplift or eustatic processes a large area of southern Victoria Land was exposed including the Olympus and Asgard Ranges and Bull Pass-St Johns Range area. This lead to erosion of the New Mountain Formation and basement rocks. Deposition of the New Mountain Sandstone continued further south shown by the gradational contact between it and the overlying Altar Mountain Formation. Relative sea level rise led to deposition of the Altar Mountain Formation. Shallow seas once more dominated the southern Victoria Land with deltas in the east (in the Bull Pass-St Johns Range area) feeding feldspathic sediment into the depositional basin (Odin Member). Further sea level rise drowned the delta region and a shallow marine to inner shelf environment led to deposition of the rest of the Altar Mountain Formation.
15

The historical and religious antecedents of the New Beacon Series in Religious Education (1937)

Parke, David Boynton January 1965 (has links)
Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / This study traces the tendencies of thought and the institutional processes which culminated in the New Beacon Series in Religious Education, inaugurated by the American Unitarian Association in 1937. This curriculum is still in use in the large majority of Unitarian Universalist churches today. This study is based both on published and manuscript sources and on interviews with the persons most involved in the creation of the series. The study begins with a chapter of historical background, in which the distinctive characteristics of Judaic, Christian, Unitarian, and progressive education are delineated. It is showm that religious and secular education were integrated in Judaism, in the Reformation, and in the moral education movement pioneered by Horace Mann and Horace Bushnell. This integrated approach, whereby the child is regarded as a unity and religion is regarded as indigenous to children's growth, achieved articulation in the twentieth century in the progressive education movement, and is foundational to the New Beacon Series. The immediate precursors of the New Beacon Series, namely the Beacon Series of 1909 and the Beacon Course of 1912, are described. While the innovations contained in these curricula derived primarily from the assumptions and methodology of progressive education, it is shown that the curricula also contained residues of what many Unitarians considered to be outmoded theological, ethical, and psychological worldviews which limited their usefulness. Of the many individuals and groups who contributed to the making of the series, three persons are studied in detail: Angus H. MacLean, who contributed to the climate of ideas out of which the series emerged; Ernest W. Kuebler, who administered the Division of Education of the--American Unitarian Association while the series was in process of creation; and Sophia L. Fahs, who was the prime mover of the series as Children's Editor. It is demonstrated that Mrs. Fahs successively (1) abandoned the concept of the deity of Christ in favor of a more liberal view of his humanity; (2) abandoned the concept that all religious instruction should be Bible-centered in favor of an extra-Biblical orientation including missionary biography and world stories; (3) modified the concept of formal classroom learning in favor of an experimental curriculum, as derived from the educational philosophy of John Dewey; and (4) augmented the life situation approach with a concept of vicarious learning based on the assumed congruity of childhood experience and early racial experience, as derived from the philosophy of G. Stanley Hall. The creation of the New Beacon Series is described book by book, from Beginnings of Earth and Sky in 1937, the initial volume, to Today's Children and Yesterday's Heritage in 1952, the definitive theoretical statement of its philosophy. No attempt is made to trace the development of the series after 1952. It is shown that the series evolved from the premise of progressive education that all learning is contingent upon the needs and capacities of the child. The approach to younger children presupposed the principle of growth, and emphasized social and natural experience. The approach to older children presupposed, in addition to the principle of growth, the principle of the equivalence of immediate and vicarious experience, and emphasized world culture and religious biography, drawing heavily upon the Christian Bible. In the New Beacon Series, three basic principles are shown to be operative. First, the child is the arbiter of his own growth; religious instruction conforms to the growth of the child, rather than the reve~se. Secondly, Biblical models are employed not for their inherent superiority but for their power to illustrate religious values. Thirdly, openness, tentativeness, and wonder are prized as evidence of continuing growth, and there is no end to the process of growth save more growth. / 2031-01-01
16

Novel Ester Substrates for the Detection and Treatment of Prostate Cancer

McGoldrick, Christopher Allen 01 December 2013 (has links)
Cancer cell esterases are often overexpressed and some have chiral specificities different from those of corresponding normal cells. Carboxylesterases in particular are known to be overexpressed in several cancers. Additionally, cancer cells often exhibit high levels of intrinsic oxidative stress that is required for survival and an aggressive phenotype. We hypothesized that these 2 characteristics of cancer cells could be exploited to aid in the detection and treatment of prostate cancer. We have developed a fluorogenic ester probe that is activated by carboxylesterase to help distinguish tumorigenic cells from nontumorigenic prostate cells. Ester prodrugs have the same activation mechanism and have been thought to be a promising approach in cancer therapy. Prodrugs are inactive drugs that can be selectively activated by a specific enzyme. We have developed a chiral ester prodrug strategy using native polyacrylamide gel electrophoresis (n-PAGE) and proteomic methods to compare and identify the esterase profiles of several tumorigenic and nontumorigenic prostate cell lines. Our results showed that cell lysates from LNCaP, DU 145, and PC3 prostate cancer cell lines exhibit differential esterase activity compared with non-tumorigenic RWPE-1 prostate cell lysates when incubated with α- naphthyl acetate or α-naphthyl N-acetyl-alaninate ester substrates and a diazonium salt. We have identified oxidized protein hydrolase (OPH), a serine esterase/protease that catalyzes the removal of N-acylated residues from proteins, to be differentially expressed between some tumorigenic and nontumorigenic prostate cell lines. OPH was found to have high hydrolytic activity towards the S-isomer of α-naphthyl N-acetylalaninate (S-ANAA) chiral ester. LNCaP lysates incubated with N-acetyl-alanyl-p-nitroanilide, a known OPH substrate, had twofold higher OPH activity compared with RWPE-1 lysates. We have also developed and tested novel glutathione depleting prodrugs modeled after S-ANAA that increase oxidative stress and induced apoptosis in tumorigenic prostate cells with little effect on nontumorigenic RWPE-1 cells. These results suggest that ester molecular beacon probes and ester prodrugs may be effective in identifying and treating prostate cancer tumors that overexpress esterases with little effect on normal prostate cells.
17

Attacking and Securing Beacon-Enabled 802.15.4 Networks

JUNG, SANG SHIN 04 May 2011 (has links)
The IEEE 802.15.4 has attracted time-critical applications in wireless sensor networks (WSNs) because of its beacon-enabled mode and guaranteed timeslots (GTSs). However, the GTS scheme’s security still leave the 802.15.4 MAC vulnerable to attacks. Further, the existing techniques in the literature for securing 802.15.4 either focus on non beacon-enabled 802.15.4 or cannot defend against insider attacks for beacon-enabled 802.15.4. In this thesis, we illustrate this by demonstrating attacks on the availability and integrity of the beacon-enabled 802.15.4. To proof the attacks, we implement the attacks using Tmote Sky motes for a malicious node along with regular nodes. We show that the malicious node can freely exploit the beacon frames to compromise the integrity and availability of the network. For the defense, we present beacon-enabled MiniSec (BCN-MiniSec) and analyze its cost.
18

IEEE 802.15.4 MAC Protocol Study and Improvement

Cheng, Liang 27 November 2007 (has links)
IEEE 802.15.4 is a standard used for low rate personal area networks (PANs). It offers device level connectivity in applications with limited ower and relaxed throughput requirements. Devices with IEEE 802.15.4 technology can be used in many potential applications, such as home networking, industry/environments monitoring, healthcare equipments, etc, due to its extremely low power features. Although the superframe beacons play the key role in synchronizing channel access in IEEE 802.15.4, they are sources for energy inefficiency. This research focuses on exploring how to optimize the beacons, and designing novel schemes to distribute the information that are supposed to be delivered to a subset of PAN devices. In this work, an acknowledgement based scheme is proposed to reduce the energy consumption in the distribution of guaranteed time slot (GTS) descriptors. Based on the observation that the superframe beacon frame has global impact on all PAN devices, an energy-efficient channel reservation scheme is presented to deliver the information (GTS descriptors and pending addresses). In addition, the problem of channel underutilization is studied in the contention free period. To address the problem, a new GTS allocation scheme is proposed to improve the bandwidth utilization.
19

Šviesos diodų švyturio kūrimas ir tyrimas / LED beacon development and study

Jurgulis, Vygantas 11 June 2013 (has links)
Baigiamajame magistriniame darbe sukurta nauja šviesos diodų švyturio koncepcija. Nauja šviesos diodų švyturio koncepcija sukuria šviesos spindulio sukimosi efektą. Tai pasiekiama naudojant mikrovaldiklį, kuris pakeičia elektros pavaras reikalingas sukti šviesą atspindinčius reflektorius. Baigiamajame darbe aprašytas sklandaus šviesos spindulio sukimosi efekto išgavimo būdas, taip pat pateikiamas šviesos diodų švyturio modelis. Eksperimento metu išgautas šviesos sukimosi efektas, padarytos išvados bei rekomendacijos. / For the master thesis a new light-emitting diodes beacon concept, was created. This LED beacon creates a beam rotation effect. This is achieved by using a microcontroller that replaces the electric drive required to rotate reflector. For final project was proposed new smooth beam rotation effect extraction method, as well as the light-emitting diodes beacon model. During the experiment, beam rotation effect was obtained, and conclusions and recommendations was made.
20

To Cue or Not to Cue: Beacons and Landmarks in Object-displacement Tasks

Mangalindan, Diane Marie 08 August 2013 (has links)
Two experiments examined the role of various cues on children’s performance in a well-known object-displacement task. In this task, children observed a toy rolling down a ramp whose trajectory was occluded by an opaque screen with doors. A barrier was placed along the ramp, behind one of the doors, to stop the toy. The top portion of the barrier was visible above the screen. To search successfully, children had to retrieve the hidden toy by opening the correct door. Previous work had found that the barrier was an ineffective cue among children less than three years of age. According to a landmark-based account, this was because the barrier was only an indirect cue to object location. If a cue directly marked the location, then it would be more likely attended and utilized. This model underscores the spatial relation between cue and the target. Other cue properties are important in so far that they modify this spatial relation. In Experiment 1, a cue’s distance from the target object was manipulated (i.e., short vs. long), but the location marked by the cue was kept constant (i.e., correct door was directly below). The search performances of 24- and 30-month old children were compared under no cue, short-cue/short-door, and long-cue/long-door conditions. Both age groups performed equally well under both cued conditions. In Experiment 2, a cue’s movement (i.e., coincident with the car vs. not coincident with the car) down the ramp was manipulated. The performance of 24- and 30-month old children were compared under attached-direct cue and unattached-direct cue conditions. Both age groups performed well under both conditions. Collectively, the results provide support for the landmark-based account. The spatial relation between cue and target underlies toddlers’ search. Properties of the cue matter to the extent that they impact how well the cue marks its target.

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