2,088 research outputs found
Relaxed Game Chromatic Numbers of Complete Multipartite Graphs
Competitive graph coloring is investigated by studying a game with two players, Alice and Bob, on a finite graph G with a set of r colors. Alice and Bob alternately color the vertices of G with legal colors. In the k-relaxed coloring game, a color c is legal for a vertex v if v has at most k neighbors previously colored c. New results about the 0, 1, and 2-relaxed game chromatic numbers will be presented, completely classifying the 0 and 1-relaxed games and partially classifying the 2-relaxed game. These results will be presented in the context of previous research and given a direction of where they need to go next
Superintendents and Professional Development: Voices from the Field
The primary task of the educational leader is to assure high quality learning environments for all students. Research (Gordon, 2004; Sparks, 2007) supports the proposition that effective professional development contributes to instructional improvement by building educator capacity. Much of the research on professional development focuses in principal leadership in improving instruction (Blase & Blase, 2004). But district level administrators, especially the superintendent of schools, also have a role to play in school improvement. Standards for the preparation of school leaders specify competencies for superintendents that include the design and implementation of professional development programs based on sound research, best practices, district-and school-level data, and other contextual information (National Policy Board, 2002). The National Staff Development Council\u27s Standards (2001) also describe a comprehensive set of activities to improve student learning that apply to both campus and district level personnel. But while the research on the instructional leadership role of principals is extensive, comparatively little is said about how superintendents meet their own responsibilities in this area (Dufour, 2000; Hirsch, 2009; Firestone, Manquin, & Martinez, 2005)
Improving Financial Inclusion through the Delivery of Cash Transfer Programmes: The Case of Mexico’s Progresa-Oportunidades-Prospera Programme
This paper follows a quasi-experimental research design to assess the impact of the electronic payment system of Mexico’s Progresa-Oportunidades-Prospera (POP) programme. The switch from cash payments to electronic payments delivered via savings accounts is found to have medium-term effects on savings decisions, transaction costs, and coping strategies. Overall, the study finds that, following the intervention, a substitution effect emerged between saving portfolio choices, with the poor favouring bank accounts over informal saving arrangements.
It also found that the Oportunidades savings account led to an increase in remittance reception, which in turn
had important implications for household consumption smoothing and risk management decisions. The study also
reveals impact heterogeneity depending on household composition and the rural-urban divide, with important
implications for replicability of similar policy innovations in other countrie
Keanekaragaman Kupu-Kupu (Lepidoptera) di Sekitar Pinggiran Sungai Maslete Kabupaten Timor Tengah Utara
Penelitian tentang keanekaragaman kupu-kupu sudah banyak dilakukan khususnya di pulau Jawa, namun belum semua wilayah di Indonesia diperoleh data tentang keanekaragaman kupu-kupu. Salah satu di Kabupaten Timor Tengah Utara masih belum banyak dilakukan, khususnya di sekitar pinggiran sungai Maslete, Kabupaten Timor Tengah Utara. Tujuan dari penelitian ini adalah untuk mengetahui jenis-jenis kupu-kupu, untuk mengetahui keanekaragaman kupu-kupu, untuk mengetahui faktor-faktor lingkungan yang mempengaruhi kehidupan kupu-kupu di sekitar pinggiran sungai Maslete Kabupaten Timor Tengah Utara serta untuk mengetahui implementasi hasil penelitian dalam pembelajaran biologi di sekolah. Metode yang digunakan dalam penelitian ini yaitu metode jelajah. Penentuan lokasi pengambilan sampel dilakukan dengan metode purposive sampling. Pengambilan sampel dilakukan dengan mengikuti garis transek sepanjang 500m, Pada garis transek dibuat substransek. Jarak antar subtransek yaitu 250m. Pada masing-masing subtransek dibuat 2 buah plot berukuran 5x5 m2. Kupu-kupu ditangkap menggunakan jaring dan identifikasi berdasarkan cirri morfologi kupu-kupu. Data yang diperoleh dianalisis keanekaragamannya menggunakan indeks keanekaragaman Shannon-wienner. Hasil penelitian di sekitar pinggiran sungai maslete ditemukan 7 jenis kupu-kupu yang tergolong dalam 3 famili yaitu Pieridae dengan 3 jenis, Nymphalidae dengan 2 jenis dan Papilionidae dengan 2 jenis. Indeks keanekaragaman kupu-kupu di sekitar pinggiran sungai maslete tergolong rendah dengan nilai H\u27 0,9884. Hasil pengukuran parameter lingkungan di sekitar pinggiran sungai Maslete menunjukkan bahwa suhu udara berkisar antara 34,37-34,67o C dan kelembaban udara berkisar antara 57-59%
Chemical composition and origin of nebulae around Luminous Blue Variables
We use the analysis of the heavy element abundances (C, N, O, S) in
circumstellar nebulae around Luminous Blue Variables to infer the evolutionary
phase in which the material has been ejected.
(1) We discuss the different effects that may have changed the gas
composition of the nebula since it was ejected
(2) We calculate the expected abundance changes at the stellar surface due to
envelope convection in the red supergiant phase. If the observed LBV nebulae
are ejected during the RSG phase, the abundances of the LBV nebulae require a
significantly smaller amount of mass to be lost than assumed in evolutionary
models.
(3) We calculate the changes in the surface composition during the main
sequence phase by rotation induced mixing. If the nebulae are ejected at the
end of the MS-phase, the abundances in LBV nebulae are compatible with mixing
times between 5 x 10^6 and 1 x 10^7 years. The existence of ON stars supports
this scenario.
(4) The predicted He/H ratio in the nebulae are significantly smaller than
the current observed photospheric values of their central stars.
Combining various arguments we show that the LBV nebulae are ejected during
the blue SG phase and that the stars have not gone through a RSG phase. The
chemical enhancements are due to rotation induced mixing, and the ejection is
possibly triggered by near-critical rotation. During the ejection, the outflow
was optically thick, which resulted in a large effective radius and a low
effective temperature. This also explains the observed properties of LBV dust.Comment: 18 pages, 4 figures, to be published in The Astrophysical Journal,
April 20, 200
Topical Delivery of Haptens: Methods of Modulation of the Cutaneous Permeability to Increase the Diagnosis of Allergic Contact Dermatitis
Lossy Multi/Hyperspectral Compression HW Implementation at high data rate
Image compression is becoming more and more important, as new multispectral and hyperspectral instruments are going to generate very high data rates due to the increased spatial and spectral resolutions. Transmitting all the acquired data to the ground segment is a serious bottleneck, and compression techniques are a feasible solution to this problem. The CCSDS has established a working group (WG) on multispectral and Hyperspectral Data Compression (MHDC), which has the purpose of standardizing compression techniques to be used onboard. The WG has already standardized a lossless compression algorithm for multispectral and hyperspectral images, and has started working on a lossy compression algorithm. The complexity of lossless compression algorithms is typically larger than that of lossy ones, leading to potentially lower throughputs. Therefore, a careful assessment is required in order to identify techniques that are able to sustain very high data rates. The increased complexity can also lead to increased resource occupancy on a hardware device such as an FPGA. Lossy compression introduces information losses in the images, and these losses must be accurately characterized, and their effect on the applications investigated. For these reasons, developing a lossy algorithm requires a more elaborate process. Under an ESA contract primed by Politecnico of Torino, TSD is currently designing an IP core for FPGA and/or ASIC implementation of a lossy compression algorithm that is being proposed for CCSDS standardization. In addition to the IP core, TSD is developing a HW platform based on the Xilinx Virtex-5 XQR5VFX130, the industry's first high performance rad-hard reconfigurable FPGA for processing-intensive for space systems. Advanced results along with details of electronic platform design will be presented in this paper
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