380 research outputs found

    Polyphase alternating codes

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    This work introduces a method for constructing polyphase alternating codes in which the length of a code transmission cycle can be pmp^m or p1p-1, where pp is a prime number and mm is a positive integer. The relevant properties leading to the construction alternating codes and the algorithm for generating alternating codes is described. Examples of all practical and some not that practical polyphase code lengths are given.Comment: Submitted to Annales Geophysica

    Application of tomographic inversion in studying airglow in the mesopause region

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    Tulevaisuuden rakennusmateriaalit infrarakentamisessa

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    Tiivistelmä. Tässä työssä selvitetään lakiuudistusten ja ilmastopolitiikan vaikutuksia rakennusmateriaaleihin sekä rakennusmateriaalien osuutta rakentamisen hiilijalanjäljestä. Suomessa rakentaminen ja sen materiaalit aiheuttavat jopa 30 % Suomen hiilidioksidipäästöistä. Päästöjen vähentämiseksi pyritään jatkuvasti löytämään uusia keinoja, koska niillä on potentiaalia päästövähennyksiin. Materiaalien päästövähennyspotentiaalin vuoksi niihin kohdistuu erilaisia vaatimuksia ja uudistamistarpeita, joita etsitään jatkuvasti. Kirjallisuustutkimuksella on selvitetty lainsäädännön tilaa liittyen vähähiilisiin rakennusmateriaaleihin sekä selvitetty miten ja millaisia materiaaleja on tällä hetkellä infrarakentamisessa käytössä. Kirjallisuustutkimuksen lisäksi työssä toteutettiin kyselytutkimus infrarakentamisen uusista materiaaleista ja lainsäädännön vaikutuksista rakentamisen kehitykseen. Tutkimukseen kutsuttiin mukaan alan osaajia eri toimijoista: materiaalitoimittajista, viranomaisista, rakennusliikkeiden asiakkaista, tilaajista ja muista asiantuntijoista. Kyselytutkimuksen tavoitteena oli selvittää osapuolten näkemyksiä tulevista uudistuksista ja niiden vaikutuksista infrarakentamiseen ja rakennusmateriaaleihin, sekä tunnistaa ainakin yksi merkittävä tekijä, jolla on todellista vaikutusta materiaalien kehittämistyössä ja käytön lisäämisessä. Kyselytutkimuksen vastauksissa nousivat esiin erityisesti toiveet materiaalien sujuvammasta käytöstä, tutkimuksen kehittämisestä sekä säädösten ja ohjeistusten parantaminen. Osapuolet toivoivat uusiomateriaaleille siis sujuvampia lupaprosesseja sekä rakentamista ilman tiukkoja säädöksiä, koska lupaprosessit voivat olla usein aikaa vieviä, ja jolloin rakentaminen voidaan joutua toteuttamaan toisella materiaalilla. Jotta rakentamista voitaisiin saada ympäristöystävällisemmäksi, olisi lainsäädäntöön saatava muutoksia. Kaikkiaan vastaajat pitivät merkittävimpinä tekijöinä uudistusten osalta koulutuksen ja tutkimuksen kehittämistä, lupakäytäntöjen ja -prosessien suoraviivaistamista ja selkeyttämistä. Vastaajat ja vastaukset kattavat hyvin rakennusalan eri osapuolia ja voidaan olettaa, että alan näkemys vastaa yleisesti tutkimuksessa saatuja tuloksia. Kyselytutkimuksessa saatuja vastauksia ja tuloksia käytetään ainoastaan tässä työssä. Tulokset ja kysymykset on avattu selkeästi, jotta tutkimus on toistettavissa myöhemmin.Construction materials of the future in infrastructure construction. Abstract. In this work, the goal was to investigate the effects of legal reforms and climate policy for construction materials and the construction materials part in the carbon footprint. In Finland, construction and its materials cause up to 30% of carbon dioxide emissions of Finland. New ways to reduce emissions are constantly being sought, as they have the potential to reduce emissions. Due to the emission reduction potential of materials, they face different requirements and needs for renewal, which are constantly being sought. The literature review has examined the state of legislation related to low-carbon construction materials and how and what kind of materials are currently used in infrastructure construction. In addition to the literature research, there was conducted a survey of new materials in infrastructure construction and the effects of legislation on the development of construction. Experts from various actors in the field: material suppliers, authorities, customers, and other experts were invited to participate in the study. The aim of the survey was to find out the parties’ views on future reforms and their impact on infrastructure and construction materials, and to identify at least one significant factor that has a real impact on the development of materials and increasing usage. The responses to the survey highlighted the desires for the smoother use of materials, the development of research and the improvement of regulations and guidelines. The parties called for smoother permitting processes for recycled materials, as well as construction without strict regulations, as permitting processes can often be time-consuming and construction may have to be carried out with another material. Legislation needs to be changed to make construction more environmentally friendly. Overall, the respondents considered that the most important factors for reform were the development of education and research, streamlining and clarification of permitting practices and processes. The various parties of the construction industry are covered well by respondents and responses, and it can be assumed that the view of the industry is basically in line with the results of the survey. The answers and results obtained in the survey are used only in this work. The results and questions have been clearly opened so that the study can be repeated later

    Application of stochastic inversion in auroral tomography

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    Application of Tomographic Inversion in Studying Airglow in the Mesopause Region

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    It is pointed out that observations of periodic nightglow structures give excellent information on atmospheric gravity waves in the mesosphere and lower thermosphere. The periods, the horizontal wavelengths and the phase speeds of the waves can be determined from airglow images and, using several cameras, the approximate altitude of the luminous layer can also be determined by triangulation. In this paper the possibility of applying tomographic methods for reconstructing the airglow structures is investigated using numerical simulations. A ground-based chain of cameras is assumed, two-dimensional airglow models in the vertical plane above the chain are constructed, and simulated data are calculated by integrating the models along a great number of rays with different elevation angles for each camera. After addition of random noise, these data are then inverted to obtain reconstructions of the models. A tomographic analysis package originally designed for satellite radiotomography is used in the inversion. The package is based on a formulation of stochastic inversion which allows the input of a priori information to the solver in terms of regularization variances. The reconstruction is carried out in two stages. In the first inversion, constant regularization variances are used within a wide altitude range. The results are used in determining the approximate altitude range of the airglow structures. Then, in the second inversion, constant non-zero regularization variances are used inside this region and zero variances outside it. With this method reliable reconstructions of the models are obtained. The number of cameras as well as their separations are varied in order to find out the limitations of the method

    Knowledge, Skills, and Support Needed by Teaching Personnel for Managing Challenging Situations with Pupils

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    It is not uncommon for teachers to face challenging behavioral issues in their classrooms, including disruptive, aggressive, or insulting behavior toward peers or adults. In this paper, we describe what knowledge, skills, and support is needed among teaching personnel to manage challenging situations with pupils. This study was carried out in one comprehensive school in Southwest Finland. Two focus group interviews were conducted with teaching personnel (schoolteachers and classroom assistants, N = 16). The participants also wrote short texts about challenging situations they had experienced. The qualitative data were analyzed with inductive content analysis. According to the results, the teaching personnel needed better knowledge about the factors affecting pupils' behavior and about good practices to apply with pupils in challenging situations. Moreover, the personnel lacked the skills needed to anticipate and recognize pupils' moods and signs of mental distress, and expressed the desire for support from mental health professionals. Teachers with adequate knowledge about the factors linked to behavioral issues are more capable of promoting environments conducive to positive interactions with their pupils, thereby limiting challenging situations. When developing education and support for teaching personnel, collaboration between education and mental health professionals is essential

    Hydrocarbon fluxes above a Scots pine forest canopy: Measurements and modeling

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    International audienceWe measured the fluxes of several hydrocarbon species above a Scots pine (Pinus sylvestris) stand using disjunct eddy covariance technique with proton transfer reaction ? mass spectrometry. The measurements were conducted during four days in July at SMEAR II research station in Hyytiälä, Finland. Compounds which showed significant emission fluxes were methanol, acetaldehyde, acetone, and monoterpenes. A stochastic Lagrangian transport model with simple chemical degradation was applied to assess the sensitivity of the above canopy fluxes to chemistry. According to the model, the chemical degradation had a minor effect on the fluxes measured in this study but has a major effect on the vertical flux profiles of more reactive compounds, such as sesquiterpenes. The monoterpene fluxes followed the traditional exponential temperature dependent emission algorithm but were considerably higher than the fluxes measured before at the same site. The normalized emission potential (30°C) was 2.5 ?g gdw?1 h?1 obtained using the temperature dependence coefficient of 0.09°C?1
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