1,543 research outputs found

    The Continuing Quest for Missile Defense: When Lofty Goals Confront Reality

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    For almost three quarters of a century, the United States has spent billions of dollars and countless person-hours in the pursuit of a national missile defense system that would protect the country from intercontinental ballistic missiles (ICBM) carrying nuclear warheads. The system currently in place consists of 44 long-range antiballistic missiles stationed in Alaska and California to protect the United States from a possible nuclear weapon carrying ICBM attack from North Korea. After all this effort, this system is still imperfect, being successful only 10 out of 18 tests. This book will provide an historical description of past efforts in national missile defenses to understand the technical difficulties involved. It will also explain how national security concerns, the evolving international environment, and the complexities of US politics have all affected the story. The book will also describe the current systems in place to protect allies and troops in the field from the threat of shorter range missiles. Finally, the book will describe the current US vision for the future of missile defenses and provide some suggestions for alternative paths.https://cupola.gettysburg.edu/books/1142/thumbnail.jp

    Exploring the Impact of Teacher Collaboration on Student Learning: A Focus on Writing

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    In this yearlong case study, six English teachers in an urban high school in Northern California engaged in sustained collaboration focused on developing and enacting strategies to improve the writing skills of their culturally and linguistically diverse freshmen. The study was conducted between August 2018 and June 2019, to determine the connections, if any, between teacher collaboration and student learning. Qualitative data were analyzed from teacher collaboration and observation of classroom practices, focus groups and teacher-created artifacts. Students’ on-demand writing assessments in fall and spring were compared with instructionally supported writing. Student surveys were analyzed in a mixed methods approach. Findings suggest that students’ writing skills improved and students reported increased confidence in writing and other literacy practices. The lessons developed in the collaboration meetings and observed in practice, in tandem with student and teacher self-reports suggest a positive relationship between teacher collaboration and student learning outcomes

    Simulation of Energy Consumption in Multi Cluster Wireless Sensor Networks

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    Energy conserving protocols in wireless sensor networks (WSNs), such as S-MAC, introduce multi-cluster network. The border nodes in multi cluster WSNs have more active time than the other nodes in the network; hence have more energy depletion rate. Since battery replacement in most networks is considered difficult, one or more nodes running out of energy prematurely will affect the network connectivity and decrease the overall network performance severely. This paper aims to (1) analyze the energy consumption in a multi-cluster sensor network and compare it to the single cluster scenario (2) investigate the merging time in a single cluster network. The result shows that, in average the energy needed to deliver a packet in the multi cluster networks is about 150% more than the energy needed in the single cluster networks. Moreover, the merging time in the single cluster network using schedule offset as the merging criteria in average is slightly smaller than one in the network using schedule ID as the merging criteria

    Measures of tuna abundance from purse-seine operations in the Eastern Pacific Ocean, adjusted for fleet-wide evolution of increased fishing power, 1960-1971

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    ENGLISH: The fishing power of the tuna purse-seine fleet of the eastern Pacific Ocean has increased since the early 1960's. Because the entire fleet seems to have adopted equipment and techniques to increase its efficiency in capturing tunas, traditional methods of adjusting catch rates to a reference vessel type of fixed efficiency to index tuna abundance from fishing success are inapplicable. Instead, a methodology for such adjustment based on a mathematical representation of purse seining activities is developed. Observed changes in efficiency in subprocesses of purse seining are then used to adjust catch rates when computing abundance histories for yellowfin and skipjack in large regions of the eastern Pacific Ocean. SPANISH: La eficacia de pesca de la flota de cerco atunera en el Océano Pacífico oriental ha aumentado desde el comienzo del decenio de 1960. Como toda la flota parece haber adoptado equipo y métodos para incrementar su eficaciaen capturar atunes, no se pueden aplicar los métodos tradicionales de ajustar los índices de captura a un tipo normalizado de barco (es decir de eficacia fija) para indicar la abundancia del atún según los resultados de pesca. En su lugar se ha desarrollado un método para realizar tal ajuste basado en una representación matemática de las actividades de las embarcaciones de cerco. Cuando se calcula la abundancia histórica del atún aleta amarilla y barrilete en grandes regiones del Océano Pacífico oriental, se usan entonces los cambios observados en la eficacia de los subprocesos cerqueros para ajustar los índices de captura. (PDF contains 120 pages.

    The distribution, abundance, and ecology of larval tunas from the entrance to the Gulf of California

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    ENGLISH: This study is based on collections of larvae of Thunnus albacares, Euthynnus llneatus, and Auxis sp. obtained from surface and oblique net tows made during seven cruises, each along a comparable track in the entrance of the Gulf of California and each during a different month. Concomitant measurements of surface temperature, salinity, and zooplankton were made at each of the plankton stations. The catches of larval Auxis sp. were examined by analysis of variance techniques to determine which environmental features were associated with the spawning of this tuna as indicated by the distribution of larvae and to gain some insight into the behavior of the larvae themselves. The testing indicated that the spawning of Auxis sp. varied significantly among the different months of the cruises. The testing also indicated that if the larvae were capable of avoiding the sampling apparatus, this ability was not related to features associated with time of day such as light conditions. The analysis did not detect any change in the vertical distribution of the larvae among the months of the experiment. It was concluded that the larvae did not exhibit a diel vertical movement. The measurements of temperature, salinity, and zooplankton volumes were treated as covariates in the analysis. The surface temperature proved to be a highly important factor in explaining the distribution of larvae, but salinity and zooplankton volumes were not. Catches of Thunnus albaeares and Euthynnus lineatus were rare during the course of the study; these are discussed in qualitative terms with respect to the time of the year and the surface temperature. The distribution of larval tunas in the area of study was compared with the distribution of surface water masses. It appeared that these masses had no influence per se on the distribution of larvae. SPANISH: Este estudio está basado en las recolecciones de larvas de Thunnus albacares, Eutbynnus lineatus, y Auxis sp. obtenidas según los arrastres superficiales y oblicuos de la red, realizados durante siete cruceros, cada uno a la entrada del Golfo de California a lo largo de un derrotero comparable, y cada uno durante distintos meses. Las mediciones correspondientes de la temperatura superficial, salinidad y de zooplancton se realizaron en cada una de las estaciones de plancton. Las capturas de larvas Auxís sp. fueron examinadas mediante el análisis de la varianza para determinar cuales características ambientales se encontraban asociadas con el desove de este atún según lo indicaba la distribución de las larvas, y para obtener alguna idea del comportamiento de las larvas en sí mismas. Las pruebas indicaron que el desove de Auxis sp. varió significativamente entre los diferentes meses de los cruceros; indicaron también que si las larvas eran capaces de evitar el aparato de muestreo, esta habilidad no se relacionaba a las características asociadas con la hora del día de acuerdo a las condiciones de luz. El análisis no demostró ningún cambio en la distribución vertical de las larvas durante los meses del experimento. Se determinó que las larvas no exhiben un movimiento vertical diario. Las mediciones de temperatura, salinidad, y de los volúmenes de zooplancton fueron tratadas como covariables en el análisis. La temperatura superficial demostró ser un factor altamente importante en la explicación de la distribución de las larvas, pero la salinidad y los volúmenes de zooplancton no lo fueron. Las capturas de Thunnus albacares y Eutbynnus lineatus fueron pocas durante el curso de este estudio; éstas se discuten en términos cualitativos respecto a la época del año y a la temperatura superficial. La distribución de los atunes larvales en el área de estudio fue comparada con la distribución de las masas superficiales de agua. Parece que estas masas no tienen influencia per se en la distribución de las larvas. (PDF contains 40 pages.

    Ancient Greek 'logos' : an invitation to historical-comparative discourse on education

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    This study aims to present some aspects of the methodological and epistemological encounter of contemporary historical-comparative discourse on education with the ancient Greek historical-comparative logos; this encounter will pose a challenging stream of research in the area of comparative education dealing mostly with the historicity, the methodology and the epistemology of this field. Such an approach will attempt to demonstrate that the contemporary historical discourse on comparative education does not remarkably deviate from a process of reasoning and research via the ancient concept of logos.peer-reviewe

    Nursing home

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    Tato práce řeší novostavbu domu s pečovatelskou službou v Prostějově. Objekt zahrnuje 36 bytových jednotek typu 1+kk a 2 bytové jednotky 3+kk. V budově jsou navrženy další provozy související s provozem pečovatelské služby a to dvě ordinace praktických lékařů, rehabilitační a masážní prostory a dále kavárna, kadeřnický salon. Celá budova je řešena jako bezbariérová. Objekt je dvoupodlažní, nepodsklepený o členitém půdorysu a je osazen na rovinné parcele v klidné zástavbě bytových domů. V exteriéru bude vybudována nová pozemní komunikace, parkovací stání a zpevněné plochy. Střecha je navržena jako plochá jednoplášťová a plochá dvouplášťová. Nosnou konstrukci tvoří stěnový systém z keramických tvárnic a železobetonové stropy. Všechny bytové jednotky jsou situovány na jižní stranu a přístupy do objektu jsou ze strany severní.This thesis deals with the Nursing home in the city of Prostějov. The object includes 36 one room flats and 2 three room flats. There are proposed another equipments which are related to nursing services such as two surgeries, rehabilitation, massage salon, coffee bar and hairdressing salon in the building. The hole building was designed as accesible. The object is two storied, cellarless and its grand plan is indented. It is staffed on plane plot in a quiet area of apartment blocks. There are going to be build new road, parking places and surfaces outside. The roof is designed as flat single casing or double casing. The main structure system is designed as walls of ceramic blocks and ceiling of reinforced concrete. All of the flats are situated on the southern side and the entrances are situated on the northern side.

    RANCANG BANGUN DAN ANALISA UNJUK KERJA SISTEM PENGAWASAN DENGAN FRAME RATE DINAMIS BERDASARKAN DETEKSI PERGERAKAN

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     Designing the Internet of Things (IoT) based surveillance systems is usually a trade of the frame rate in the video streaming to capture any movement in the frame and the bandwidth needed to stream the video. This research proposes a way to achieve bandwidth efficiency while still stream in a required frame rate by implementing video streaming with a dynamic frame rate based on movement detection. The system comprises surveillance devices; each consists of a Raspberry Pi single-board computer connected to a camera, and a central web server that mainly handles user authorization. The system was developed using Motion server, MySQL database engine, and PHP programming language. A system measurement using Wireshark network analyzer is used to evaluate key parameters of the system such as bandwidth requirement, round trip time delay, and error packet. The result shows that using a system with a dynamic frame rate requires as little as 25% bandwidth compared to the system with fix framer rate.  Salah satu pertimbangan dalam merancang sistem pengawasan berbasis Internet of Things (IoT) adalah jumlah frame yang dikirim setiap detiknya harus cukup untuk mendeteksi setiap pergerakan yang terjadi dan bandwidth yang dibutuhkan untuk mentransmisi frame-frame tersebut . Penelitian ini bertujuan merancang sebuah sistem yang dapat mengirimkan video dengan kecepatan frame yang dinamis untuk efisiensi bandwidth. Sistem terdiri dari peralatan-peralatan pengawasan dan sebuah computer server. Setiap peralatan pengawasan terdiri dari computer single board Raspberry PI, terkoneksi dengan sebuah kamera dan menjalankan motion server untuk mengatur pengambilan gambar dan transmisi video. Komputer serr betujuan untuk otorisasi penggun dan dibangun menggunakan bahasa program PHP dan mesin basis data MySQL. Pengukuran kinerja sistem dilakukan pada jaringan lokal dengan menggunakan Wireshark. Hasil pengujian menunjukan kebutuhan bandwidth sistem dengan frame rate dinamis mencapai 25% dari kebutuhan bandwidth pada sistem dengan frame rate statis

    Evalutaion of embedded malingering indices in a non-litigating, relief seeking sample: a partial cross-validation using control, clinical, and derived groups

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    Researchers have recently noted college students fail validity measures and base rate data are needed for students meeting Slick et al.’s criteria (1999) for malingering. The association between meeting Slick Criteria and subsequent recommendations (i.e., to receive external gain) is unknown as is the diagnostic utility of embedded validity indices in this population. The authors utilized archival data from: 1) a university psychological clinic (n = 986) and 2) a university student control sample (n = 182). Measures included the Wechsler Adult Intelligence Scale-III, Wechsler Memory Scale-III, and Personality Assessment Inventory. Empirically supported embedded validity indices were utilized to retrospectively identify suspected malingering patients. Group performance, according to level of symptom credibility and level of incentive seeking, was evaluated through a series of multivariate mean comparisons. Data are presented for frequency of falling in the noncredible range on all validity indices. Diagnostic statistics for each index are presented according to hypothetical base rates. Examination of receiving psychological recommendations to obtain external incentive (i.e., academic accommodations, medications, etc.) is reported according to incentive and credibility level. University patients explicitly seeking external gain, particularly those meeting criteria for malingering, demonstrated lower performance on the measures and received a higher rate of recommendations for academic accommodations and/or medications than patients not seeking external incentive. Nevertheless, a number of diagnostic statistics indicated some embedded validity indices lack specificity for malingering in university samples. The current study supports classifying patients according to level of incentive seeking when evaluating neurocognitive performance and feigned or exaggerated deficits

    Learning to Teach Writing in the Age of Standardization and Accountability; Toward an Equity Writing Pedagogy

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    Qualitative data from over three years of a lesson study project were analyzed through a situated learning theory lens in order to describe the connections between teacher learning and the variety of situations, or contexts that shaped the learning. The lesson study professional development model included planning, observation, and student data analysis protocols. The lesson study was situated in various middle school classroom settings, which provided multiple learning contexts. Additionally, teacher learning was shaped by the larger socio-political context often comprised of accountability rhetoric, standardization, and testing pressure. This study described how two teachers negotiated balance, or theoretical equilibrium, across a variety of competing interests and social pressures in order to define and operationalize equity in their writing pedagogy. Findings from this study suggest the design of practice-based teacher professional development models like lesson study, which afford opportunities for teachers to investigate and develop equity teaching in any grade or content area
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