5,179 research outputs found
Rail Track Maintenance Planning: An Assessment Model
In Australia, railway track maintenance costs comprise between 25-35 percent of total freight train operating costs. Track maintenance planning models have been shown to reduce maintenance costs by 5 to 10 percent though improved planning. This paper describes a model which has been developed to deal with the track maintenance planning function at the medium to long-term levels. This model simulates the impacts of degrading railway track conditions and related maintenance work, in contrast to tradition models that mainly use expert systems. The model simulates the degrading track condition using an existing track degradation model. Track condition data from that model is used to determine if safety related speed restrictions are needed and what immediate maintenance work may be required for safe train operations. The model outputs the net present value of the benefits of undertaking a given maintenance strategy, when compared with a base-case scenario. The model approach has advantages over current models in investigating what if scenarios. The track engineer can assess the possible benefits in reduced operating costs from upgrading track infrastructure or from the use of improved maintenance equipment. After describing the model inputs and the assumptions used, the paper deals with the simulation of track maintenance and of train operating costs over time. The results of applying the model to a test track section using a number of different maintenance strategies are also given
Understanding Database Reconstruction Attacks on Public Data
In 2020 the U.S. Census Bureau will conduct the Constitutionally mandated decennial Census of Population and Housing. Because a census involves collecting large amounts of private data under the promise of confidentiality, traditionally statistics are published only at high levels of aggregation. Published statistical tables are vulnerable to DRAs (database reconstruction attacks), in which the underlying microdata is recovered merely by finding a set of microdata that is consistent with the published statistical tabulations. A DRA can be performed by using the tables to create a set of mathematical constraints and then solving the resulting set of simultaneous equations. This article shows how such an attack can be addressed by adding noise to the published tabulations, so that the reconstruction no longer results in the original data
Discrepancy between strength and function in adults with obstetric brachial plexus lesions
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108706/1/dmcn12525.pd
Providing cryptographic security and evidentiary chain-of-custody with the advanced forensic format, library, and tools
This paper presents improvements in the Advanced Forensics Format Library version 3 that provide for digital signatures and other cryptographic protections for digital evidence, allowing an investigator to establish a reliable chain-of-custody for electronic evidence from the crime scene to the court room. No other system for handling and storing electronic evidence currently provides such capabilities. This paper discusses implementation details, user level commands, and the AFFLIB programmer's API.Approved for public release; distribution is unlimited
Notes on the Codling moth
The Codling Moth (Carpocapsa pomonella) is attracting so much
attention at present that I hope I may be excused for making some
remarks upon the subject.
This insect belongs to that family of the Lepidoptera called Tortricidae
(in French, "Tordeuses"), on account of the general habit of
their larvae of "twisting" or rolling up the leaves of plants of
their abode, usually those leaves enclosing a young shoot or
bud. They then devour such leaves, shoots or buds, to the great
detriment of the plant attacked. A few take up their abode in the
interior or fruits, especially the apple, pear, and plum
PENGEMBANGAN MEDIA PEMBELAJARAN KIMIA DENGAN MATERI POKOK KARBOHIDRAT BERBASIS WEBSITE SEBAGAI SUMBER BELAJAR MANDIRI UNTUK SISWA SMA/MA
Penelitian ini merupakan penelitian pengembangan di bidang pendidikan kimia. Tujuan penelitian ini adalah mengembangkan media pembelajaran kimia dengan materi pokok karbohidrat berbasis website sebagai sumber belajar mandiri untuk siswa SMA/MA dan mengetahui kualitas media pembelajaran kimia tersebut berdasarkan penilaian lima guru kimia SMA di Daerah Istimewa Yogyakarta.
Model pengembangan yang digunakan adalah model prosedural, yaitu model yang bersifat deskriptif melalui beberapa langkah yang harus diikuti untuk menghasilkan produk. Produk awal ditinjau dan diberi masukan oleh dosen pembimbing, peer reviewer, ahli media dan ahli materi, dan selanjutnya direvisi. Produk revisi dinilai dan diberi masukan oleh lima guru kimia SMA (reviewer) di Daerah Istimewa Yogyakarta. Instrumen penilaian media pembelajaran ini berisi lima aspek penilaian, yaitu: (1) aspek kebenaran, keluasan, dan kedalaman konsep, (2) aspek kebahasaan yang digunakan, (3) aspek keterlaksanaan, (4) aspek tampilan dan (5) aspek kemudahan penggunaan. Kelima aspek tersebut terdiri atas 19 indikator penilaian. Hasil penilaian yang berupa skor kemudian di gabung dan dianalisis dengan pedoman kriteria penilaian ideal.
Hasil penelitian pengembangan ini adalah Compact Disc (CD) media pembelajaran berbasis website, dengan pokok bahasan karbohidrat untuk siswa SMA/MA. Media pembelajaran kimia berbasis website yang dikembangkan memperoleh skor rata-rata 81,6 dari skor maksimal 100, dengan persentase keidealan 81,6 %. Berdasarkan rentang persentase keidealan, media pembelajaran kimia berbasis website dengan materi pokok karbohidrat ini mempunyai kategori kualitas baik dan dapat digunakan sebagai sumber pembelajaran mandiri untuk peserta didik tingkat SMA
Memória de horta orgânica comunitária em solo urbano
Pesquisa-ação em desenvolvimento junto ao movimento de horta orgânica comunitária Vila Esperança, situado na próspera cidade econômica e tecnologicamente desenvolvida de Campinas (Estado de São Paulo – Brasil), foi idealizada como ação promotora de saúde para ressignificar área pública degradada, utilizada como bota-fora de lixo e resíduos de materiais de construção civil.
Em 2007, foi realizada a oficina "Comunidade Saudável" com representantes do poder público, universidade e lideranças comunitárias com perguntas condutoras para responderam “O que é mais importante, possível realizar / proporcionar uma comunidade saudável na região dos Amarais?”. A sugestão foi trabalhar nos eixos saúde, meio ambiente e educação; entre as propostas foi escolhida a implantação de hortas comunitárias.
Da proposta inicial de horta comunitária, o movimento passou por várias fases: solicitação de cessão de área pública, fundação de uma Associação para ser a beneficiaria da área, instalação de ponto de água, iniciativas de produção, organização do grupo, orientações para produção de olericultura orgânica.
Atualmente o grupo de agricultores e agricultoras da horta recebe orientações para a produção de hortaliças orgânicas. O programa é estruturado em preparo do solo e adubação verde, compostagem, produção de mudas, tratos culturais, pragas e doenças, colheita e comercialização.
A pesquisadora acompanha e colabora com o planejamento da implantação da horta comunitária, mantém um caderno de memória das atividades da horta, e através da metodologia de história oral, coleta depoimentos dos agricultores e agricultoras sobre o processo de migração para a região estudada e sobre as transformações territoriais, as questões socioambientais, de saúde e de consolidação da horta comunitária no bairro.
Desta experiência formamos um mosaico de histórias que se cruzam e entrecruzam com questões sociais, migração, adensamento populacional, transição entre rural e urbano, mudanças de hábitos e alimentação, qualidade de vida urbana. Entretanto, observamos desafios deste empreendimento: importância do trabalho coletivo, da produção sem uso de agrotóxicos e a sustentabilidade social, econômica e ambiental
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