931 resultados para Mac Donald, Patrick (1878-1954)
Resumo:
Digital Image
Resumo:
Clipping: "Ausstellung ueber das juedische Leben in Neustadt a. d. Aisch" from Neustaedter Rathausbote (April, 1988). Xerox copy of the front page "Anzeige-Blatt der Stadt Neustadt an der Aisch" (June 5, 1878).
Resumo:
Contains business correspondence, accounts and documents relating to Jacob Franks of New York, his two sons, Moses and David, a nephew, Isaac, and a John Franks of Halifax, possibly a member of the family.
Resumo:
Letters to Ira Goldberg from Dora Edinger (1955), Paul P. Homburger (1955), The New York Public Library (1956) in reference to Bertha Pappenheim; article about stamp dedication by the German postal service honoring Bertha Pappenheim (in Allgemeine Wochenzeitung der Juden in Deutschland, 11/5/1954)
Resumo:
Tarkastelen pro gradu -tutkielmassani naiskysymystä Seitsemännen päivän adventtikirkon oppiäiti Ellen Whiten (1827 1915) terveysopetuksessa. White tunnetaan ennen kaikkea näyistään, joiden välityksellä hän koki saavansa Jumalalta hyvinvointiin liittyviä ohjeita. White kirjoitti näkyjensä innoittama terveysoppaita ja julisti pääasiassa Yhdysvalloissa yli 70 vuotta. Päälähteenäni ovat kaksi Whiten omaelämäkertaa vuosilta 1880 ja 1915 sekä 83 artikkelia, jotka hän julkaisi adventistien johtavassa terveyslehdessä, Health Reformerissa, vuosina 1866 1878. Tutkimuskysymykseni ovat, miksi White osoitti lähes kaiken terveyteen liittyvän opetuksensa naisille ja miten hän ymmärsi terveyden osana naisen roolia ja tehtäviä. Tulkintani mukaan White julisti naisille, sillä hän uskoi, että naisen asema oli selkeytettävä. Yhdysvallat teollistui ja kaupungistui nopeasti 1800-luvulla, mikä aiheutti naisille taloudellisia, sosiaalisia ja terveyteen liittyviä ongelmia. Lisäksi toinen suuri herätys (1800 1830) synnytti keskustelua naisen roolista. Monet kirkot antoivat naisille luvan esimerkiksi saarnaamiseen, mutta Yhdysvalloissa vahvistui samaan aikaan myös käsitys naisesta kodin uskonnollisena johtajana. Ymmärrän, että Whiten mukaan ratkaisu naisen sekavaan asemaan oli terveys. Uskon, että Whiten mukaan nainen pystyi ottamaan oman paikkansa yhteiskunnassa, mikäli hän pysyi terveenä ja oppi tuntemaan terveyden periaatteet. Toisaalta White sai vaikutteita naisten yhteiskunnallisten oikeuksien puolustajilta. He ajattelivat, että vain koulutettu ja terve nainen kykeni vapautumaan avioliitosta. Toisaalta White oli naisasianaisia maltillisempi. Hän ymmärsi, että vain terve ja terveyskoulutuksen saanut nainen saattoi olla hyvä äiti. Ellen White osallistui terveysopetuksellaan keskusteluun myös naisen uskonnollisesta roolista. White oli itse kiertelevä terveyssaarnaaja. Silti hän ymmärsi, että muiden naisten kutsumus oli olla terve ja koulutettu äiti. White korosti äitien pyhyyttä luultavasti siksi, että hän pyrki turvaamaan oman auktoriteettiasemansa Adventtikirkossa. White myös luultavasti ymmärsi roolinsa ja tehtävänsä poikkeuksellisiksi ja arvosti vilpittömästi äitiyttä. Whiten mukaan äidin tehtävä oli kasvattaa terveitä ja moraalisia kansalaisia. Tehtävän arvon hän perusteli aikansa tieteellisillä teorioilla. White korosti luonnontieteilijä Charles Darwinin (1809 1882) evoluutioteorian mukaisesti, että äidin velvollisuus oli siirtää lapsilleen hyvä terveys. Käsityksensä terveyden ja moraalin suhteesta hän selitti frenologialla, jonka mukaan ihmisen elämäntavat vaikuttivat hänen luonteenpiirteisiinsä. White oli myös todennäköisesti kiinnostunut sosiaalitieteilijä Herbert Spencerin (1820 1903) ajatuksista, joiden mukaan kansalaisten kehittyessä myös yhteiskunta jalostui yhä paremmaksi. Vaikka White perusteli opetustaan modernilla tieteellä, hän oli ennen kaikkea uskonnollinen julistaja. Hän kuului 1840-luvulla herätyssaarnaaja William Millerin (1782 1849) liikkeeseen, jonka jäsenet uskoivat, että Jumala tuhoaa Yhdysvallat viimeisellä tuomiolla, mikäli kansan moraalin tila ei nopeasti kohene. Millerin liikkeen painotukset säilyivät Adventtikirkossa, joka perustettiin vuonna 1863. Siten White ymmärsi, ettei äiti ollut vastuussa vain perheensä ja kansansa maallisesta hyvinvoinnista vaan myös heidän pelastuksestaan. Whiten käsitys äidistä on mielestäni ristiriitainen. White antoi äideille paljon valtaa, mutta myös suuren vastuun. Hän korosti äitien arvokkuutta, mutta toisaalta he eivät olleet hänen mukaansa korvaamattomia. White ei myöskään huomioinut naisia, jotka eivät olleet äitejä.
Resumo:
As one of the most widely used wireless network technologies, IEEE 802.11 wireless local area networks (WLANs) have found a dramatically increasing number of applications in soft real-time networked control systems (NCSs). To fulfill the real-time requirements in such NCSs, most of the bandwidth of the wireless networks need to be allocated to high-priority data for periodic measurements and control with deadline requirements. However, existing QoS-enabled 802.11 medium access control (MAC) protocols do not consider the deadline requirements explicitly, leading to unpredictable deadline performance of NCS networks. Consequentially, the soft real-time requirements of the periodic traffic may not be satisfied, particularly under congested network conditions. This paper makes two main contributions to address this problem in wireless NCSs. Firstly, a deadline-constrained MAC protocol with QoS differentiation is presented for IEEE 802.11 soft real-time NCSs. It handles periodic traffic by developing two specific mechanisms: a contention-sensitive backoff mechanism, and an intra-traffic-class QoS differentiation mechanism. Secondly, a theoretical model is established to describe the deadline-constrained MAC protocol and evaluate its performance of throughput, delay and packet-loss ratio in wireless NCSs. Numerical studies are conducted to validate the accuracy of the theoretical model and to demonstrate the effectiveness of the new MAC protocol.
Resumo:
In this paper we have proposed and implemented a joint Medium Access Control (MAC) -cum- Routing scheme for environment data gathering sensor networks. The design principle uses node 'battery lifetime' maximization to be traded against a network that is capable of tolerating: A known percentage of combined packet losses due to packet collisions, network synchronization mismatch and channel impairments Significant end-to-end delay of an order of few seconds We have achieved this with a loosely synchronized network of sensor nodes that implement Slotted-Aloha MAC state machine together with route information. The scheme has given encouraging results in terms of energy savings compared to other popular implementations. The overall packet loss is about 12%. The battery life time increase compared to B-MAC varies from a minimum of 30% to about 90% depending on the duty cycle.
Resumo:
We propose a simple and energy efficient distributed change detection scheme for sensor networks based on Page's parametric CUSUM algorithm. The sensor observations are IID over time and across the sensors conditioned on the change variable. Each sensor runs CUSUM and transmits only when the CUSUM is above some threshold. The transmissions from the sensors are fused at the physical layer. The channel is modeled as a multiple access channel (MAC) corrupted with IID noise. The fusion center which is the global decision maker, performs another CUSUM to detect the change. We provide the analysis and simulation results for our scheme and compare the performance with an existing scheme which ensures energy efficiency via optimal power selection.
Resumo:
With the increasing adoption of wireless technology, it is reasonable to expect an increase in file demand for supporting both real-time multimedia and high rate reliable data services. Next generation wireless systems employ Orthogonal Frequency Division Multiplexing (OFDM) physical layer owing, to the high data rate transmissions that are possible without increase in bandwidth. Towards improving file performance of these systems, we look at the design of resource allocation algorithms at medium-access layer, and their impact on higher layers. While TCP-based clastic traffic needs reliable transport, UDP-based real-time applications have stringent delay and rate requirements. The MAC algorithms while catering to the heterogeneous service needs of these higher layers, tradeoff between maximizing the system capacity and providing fairness among users. The novelly of this work is the proposal of various channel-aware resource allocation algorithms at the MAC layer. which call result in significant performance gains in an OFDM based wireless system.
Resumo:
Next generation wireless systems employ Orthogonal frequency division multiplexing (OFDM) physical layer owing to the high data rate transmissions that are possible without increase in bandwidth. While TCP performance has been extensively studied for interaction with link layer ARQ, little attention has been given to the interaction of TCP with MAC layer. In this work, we explore cross-layer interactions in an OFDM based wireless system, specifically focusing on channel-aware resource allocation strategies at the MAC layer and its impact on TCP congestion control. Both efficiency and fairness oriented MAC resource allocation strategies were designed for evaluating the performance of TCP. The former schemes try to exploit the channel diversity to maximize the system throughput, while the latter schemes try to provide a fair resource allocation over sufficiently long time duration. From a TCP goodput standpoint, we show that the class of MAC algorithms that incorporate a fairness metric and consider the backlog outperform the channel diversity exploiting schemes.
Resumo:
Constellation Constrained (CC) capacity regions of a two-user Gaussian Multiple Access Channel(GMAC) have been recently reported. For such a channel, code pairs based on trellis coded modulation are proposed in this paper with MPSK and M-PAM alphabet pairs, for arbitrary values of M,toachieve sum rates close to the CC sum capacity of the GMAC. In particular, the structure of the sum alphabets of M-PSK and M-PAMmalphabet pairs are exploited to prove that, for certain angles of rotation between the alphabets, Ungerboeck labelling on the trellis of each user maximizes the guaranteed squared Euclidean distance of the sum trellis. Hence, such a labelling scheme can be used systematically,to construct trellis code pairs to achieve sum rates close to the CC sum capacity. More importantly, it is shown for the first time that ML decoding complexity at the destination is significantly reduced when M-PAM alphabet pairs are employed with almost no loss in the sum capacity.
Resumo:
In this paper, Space-Time Block Codes (STBCs) with reduced Sphere Decoding Complexity (SDC) are constructed for two-user Multiple-Input Multiple-Output (MIMO) fading multiple access channels. In this set-up, both the users employ identical STBCs and the destination performs sphere decoding for the symbols of the two users. First, we identify the positions of the zeros in the R matrix arising out of the Q-R decomposition of the lattice generator such that (i) the worst case SDC (WSDC) and (ii) the average SDC (ASDC) are reduced. Then, a set of necessary and sufficient conditions on the lattice generator is provided such that the R matrix has zeros at the identified positions. Subsequently, explicit constructions of STBCs which results in the reduced ASDC are presented. The rate (in complex symbols per channel use) of the proposed designs is at most 2/N-t where N-t denotes the number of transmit antennas for each user. We also show that the class of STBCs from complex orthogonal designs (other than the Alamouti design) reduce the WSDC but not the ASDC.
Resumo:
Wireless LAN (WLAN) market consists of IEEE 802.11 MAC standard conformant devices (e.g., access points (APs), client adapters) from multiple vendors. Certain third party certifications such as those specified by the Wi-Fi alliance have been widely used by vendors to ensure basic conformance to the 802.11 standard, thus leading to the expectation that the available devices exhibit identical MAC level behavior. In this paper, however, we present what we believe to be the first ever set of experimental results that highlight the fact that WLAN devices from different vendors in the market can have heterogeneous MAC level behavior. Specifically, we demonstrate with examples and data that in certain cases, devices may not be conformant with the 802.11 standard while in other cases, they may differ in significant details that are not a part of mandatory specifications of the standard. We argue that heterogeneous MAC implementations can adversely impact WLAN operations leading to unfair bandwidth allocation, potential break-down of related MAC functionality and difficulties in provisioning the capacity of a WLAN. However, on the positive side, MAC level heterogeneity can be useful in applications such as vendor/model level device fingerprinting.