562 research outputs found

    Optimization of deliveries from distribution points

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    We solve an optimization problem involving the assignment of transport routes to a delivery point. The general and particular cases of the optimization problem are described. An algorithm for the simplified case and ideas for the general case is presented

    Interference analysis of high frequency power line communications

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    Abstract. In power line communications, the existing in-house or in-office power distribution network can be used as a communications channel. Current broadband power line communication systems in the market deploy frequency range up to 86 MHz with transmission speeds up to 1 Gb/s. To increase the capacity even further, an extension of the frequency range above 100 MHz has been proposed in the published literature. This thesis presents an empirical study of radiated interference of high frequency broadband power line communications. Utilization of high frequencies for power line communications will cause unwanted radio interference which needs to be treated with caution. The preliminary results obtained in this work show how the components and structures of a power grid segment will contribute to the overall interference radiation when frequencies above 100 MHz are used for power line communication. The results indicate that the peak levels of radiated interference from a typical cabling in in-house or in-office power line networks reach their maximum on frequencies near 300 MHz and remain on a relatively same level on above. The peak levels are approximately 13 dB above the EN 55022 limit in the 230–1000 MHz frequency range with an injected power spectral density of -80 dBm/Hz. The results will provide valuable information when designing and making more comprehensive measurement campaigns for deciding on the national transmission levels for power line communications in UHF and higher frequencies.Korkeataajuisen sähköverkkotiedonsiirron aiheuttama säteily. Tiivistelmä. Sähköverkkotiedonsiirrossa hyödynnetään olemassa olevaa sähköverkkoa tiedonsiirtokanavana. Tällä hetkellä käytössä olevat sähköverkkotiedonsiirron standardit käyttävät taajuuksia 86 MHz:iin asti. Saavutettavat tiedonsiirtonopeudet yltävät 1 Gb/s asti. Kapasiteetin kasvattamiseksi on julkaistussa kirjallisuudessa esitetty taajuusalueen laajentamista yli 100 MHz:n taajuuksille. Tässä diplomityössä esitetään empiirinen tutkimus korkeataajuisen sähköverkkotiedonsiirron aiheuttamasta säteilystä. Korkeiden taajuuksien käyttö sähköverkkotiedonsiirrossa aiheuttaa haitallista säteilyä, joka täytyy ottaa huomioon ennen kuin taajuusaluetta voidaan laajentaa. Työssä saavutetut tulokset osoittavat kuinka sähköverkon eri komponentit vaikuttavat kokonaissäteilyyn kun yli 100 MHz:n taajuuksia käytetään sähköverkkotiedonsiirrossa. Tulokset osoittavat että tyypillisen talon tai toimistorakennuksen sähköverkossa siirretyn korkeataajuisien signaalin vuotama säteily saavuttaa maksimitasonsa 300 MHz:n taajuuteen mennessä ja ei kasva sitä korkeammilla taajuuksilla. Säteilyn maksimitasot ovat noin 13 dB EN55022 standardin rajojen yläpuolella taajuuksilla 230–1000 MHz kun sähköverkkoon syötetyn signaalin tehollinen tehotiheys on -80 dBm/Hz. Tuloksia voidaan käyttää hyödyksi laajempia mittauskampanjoita suoritettaessa kansallisten tehorajoitusten päättämiseksi kun UHF ja sitä korkeampia taajuuksia käytetään sähköverkkotiedonsiirrossa

    The effect of coating properties on the performance of a-C:H and ta-C films

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    DLC films cover a wide range of different carbon based coatings, starting from soft to extremely hard diamond-like carbon films. In this study two different types of DLC films have been studied in respect of their stress and strain characteristics and tribological performance. The coatings are hydrogenated amorphous carbon (a-C:H) coatings deposited by PECVD and tetrahedral amorphous carbon (ta-C) coating deposited by filtered arc technique. In order to evaluate the mechanical behaviour of the coatings under load, 3D FE modelling was carried out in combination with scratch testing. Also the tribological performance was evaluated with pin-on-disc tests using stepwise increasing normal load. The 3D FEM model was developed for calculating the stress and strain distributions of DLC coated systems and to evaluate how coating thickness and elastic properties affect the stress-strain state at crack initiation location. The simulation was compared to the findings to experimental observations in scratch test contact conditions, when the spherical diamond tip was moving with increased load on a coated surface. The coating performance was evaluated with scratch testing to detect the crack generation as well as the coating adhesion. When combining the simulated coating characteristics with empirical observation of coating fracture patterns the coating fracture performance and tolerance to cracking could be evaluated. A major effect of the coating elastic modulus on the stress and fracture behaviour of the coatings was observed. In the tribological testing the both coatings had a low friction performance. In the tribological testing with stepwise increasing load, the critical load for coating delamination was higher for the a-C:H coating, which is in accordance with the results of FE modelling of coating stress state

    Inflammatory biomarker score and cancer: A population-based prospective cohort study

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    BACKGROUND: Inflammation is associated with cancer but there are conflicting reports on associations of biomarkers of inflammation with cancer risk and mortality. We investigated the associations of C-reactive protein (CRP) and leukocyte count with cancer risk and mortality using individual biomarkers, and an inflammatory score derived from both biomarkers. METHODS: We conducted this analysis among 2,570 men enrolled in the population-based, prospective Kuopio Ischemic Heart Disease Risk Factor Study in Finland. During an average follow-up period of 26 years, 653 cancer cases and 287 cancer deaths occurred. We computed a z-score for each participant, with the combined z-score being the sum of each individual’s CRP and leukocyte z-scores. Multivariable-adjusted Cox proportional hazard model was used to evaluate associations with cancer risk and mortality. RESULTS: Using individual biomarkers, elevated leukocyte count was associated with an increased risk of cancer (RR = 1.31, 95 % CI 1.04-1.66), and cancer mortality (RR=, 95 % CI 1.39, 0.98-1.97). The corresponding results for CRP were (RR = 1.23, 95 % CI 0.97-1.55) for risk and (RR = 1.15, 95 % CI 0.81-1.64) for cancer mortality. Associations of the biomarkers with cancer appeared to be more robust using the combined z-score. HRs comparing men within the highest z-score quartile to those within the lowest z-score quartiles were 1.47 (95 % CI 1.16-1.88, p-trend < 0.01) for cancer risk, and 1.48 (95 % CI 1.03-2.14, p-trend = 0.09) for cancer mortality. CONCLUSION: Our study suggests that inflammation is associated with cancer risk and mortality, and combining inflammatory biomarkers into a score is a robust method of elucidating this association

    Integrated governance for managing multidimensional problems : Potentials, challenges, and arrangements

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    The implementation challenge of ecosystem-based (fisheries) management (EB(F)M) has entailed calls for integrated governance (IG) approaches in the marine field. We arranged an expert workshop to study the preconditions and applicability of IG, and to suggest how IG could be arranged in practice. Focusing on the management of the dioxin problem shared by the herring and salmon fisheries in the Baltic Sea, and using a coupled ‘insight network’- SWOT (strengths, weaknesses, opportunities, threats) methodology, we evaluated two scenarios: 1) IG of herring and salmon fisheries to benefit from collaboration between these fisheries that suffer from the same problem, and 2) IG between the fisheries sector and the food/public health sector to incorporate food safety in fisheries governance. Our results demonstrate that a variety of societal, political, institutional, operational, instrumental, and biological factors affect the applicability of IG in marine contexts, and work as preconditions for IG. While societal needs for IG were obvious in our case, as major challenges for it we identified the competing cross-sectoral objectives, path dependencies, and limitations of experts to think and work across fields. The study suggests that establishing an IG framework by adding new aspects upon the current governance structures may be easier to accept and adapt to, than creating new strategic or advisory bodies or other new capacities. Viewing IG as a framework for understanding cross-sectoral issues instead of one that requires a defined level and form of integrated assessment and management may be a way towards social learning, and thereby towards the implementation of more sophisticated, open and broad EB(F)M frameworks.Peer reviewe

    Acute compartment syndrome of the hand in Henoch-Schonlein Purpura

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    An eight year old boy with Henoch-Schonlein Purpura (HSP) presented with acute compartment syndrome (ACS) of his left hand following arterial cannulation of his radial artery in intensive care unit. Emergency decompression and fasciotomy were performed. The authors report this first case in literature and discuss how HSP can be complicated by ACS and ways to prevent the latter from happening

    Cosmological Backreaction from Perturbations

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    We reformulate the averaged Einstein equations in a form suitable for use with Newtonian gauge linear perturbation theory and track the size of the modifications to standard Robertson-Walker evolution on the largest scales as a function of redshift for both Einstein de-Sitter and Lambda CDM cosmologies. In both cases the effective energy density arising from linear perturbations is of the order of 10^-5 the matter density, as would be expected, with an effective equation of state w ~ -1/19. Employing a modified Halofit code to extend our results to quasilinear scales, we find that, while larger, the deviations from Robertson-Walker behaviour remain of the order of 10^-5.Comment: 15 pages, 8 figures; replaced by version accepted by JCA

    Подростки-спортсмены строят двойную карьеру и благополучие в условиях двойного карьерного роста: роль факторов окружающей среды

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    Рукопись поступила в редакцию: 20.12.2021.Received: 20.12.2021.Цель исследования заключалась в изучении карьерного роста и благополучия спортсменов-подростков в условиях двойного карьерного роста. В исследовании выявлены особенности адаптивности к карьере в старших классах спортивной школы. В статье представлены данные относительно того, в какой степени самооценка и пол связаны с адаптивностью к двойной карьере, определены профили адаптации к карьере спортсменов-подростков, выявлены как ожидания студентов-спортсменов в зависимости от их успехов в спорте и учебе и соответствующие ожидания их родителей связаны с их профилями адаптации к карьере. Получены новые данные относительно того, как организационная культура спортивной школы влияет на построение карьеры спортсменов-подростков.The purpose of the scientific research was to study the career growth and well-being of adolescent athletes in conditions of dual career growth. The study revealed the features of adaptability to a career in high school of sports school. The article presents data on the extent to which self-esteem and gender are associated with adaptability to a dual career, the profiles of adaptation to the career of adolescent athletes have been defined, it is also revealed how the expectations of student-athletes depending on their success in sports and studies and the corresponding expectations of their parents are associated with their profiles of adaptation to a career. The new data on how the organizational culture of a sports school affects the career development of teenage athletes have been obtained
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