17 research outputs found

    Optimization of Gait Parameters for Energy Efficiency Improvement of Farmland Robot Based on Orthogonal Experiment Design

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    In order to improve the energy efficiency of legged robots while walking on farmland, a simulation system of legged robot on farmland soil was put forward in this paper. Firstly, the finite element model of the interaction between the robot leg and the farmland soil was established, and the multi-body dynamics and the foot-ground interaction simulation were carried out in one gait cycle. Secondly, the orthogonal experiment with four factors was established to analyze the external energy required for the robot leg to walk in the soil. Then the range analysis and variance analysis of the results were carried out to optimize the energy consumption ratio. The influence of the four factors on the experimental results and the optimal gait parameters and foot structure were obtained subsequently. Finally, the no-load walking experiment in the self-developed soil-bin test-bed was carried out with the optimal gait and foot structure. The results demonstrate that the successive order of factors affecting the energy consumption ratio is foot structure, stride length, gait cycle time and stride height. The process of penetrating the soil consumes the most energy in a gait cycle. The optimization design of the foot structure and the penetration process is helpful to reduce the energy consumption of the farmland robot

    屋外調査用自律移動型ロボットの不整地移動性能

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    早大学位記番号:新7829早稲田大

    Selected Papers from IEEE ICASI 2019

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    The 5th IEEE International Conference on Applied System Innovation 2019 (IEEE ICASI 2019, https://2019.icasi-conf.net/), which was held in Fukuoka, Japan, on 11–15 April, 2019, provided a unified communication platform for a wide range of topics. This Special Issue entitled “Selected Papers from IEEE ICASI 2019” collected nine excellent papers presented on the applied sciences topic during the conference. Mechanical engineering and design innovations are academic and practical engineering fields that involve systematic technological materialization through scientific principles and engineering designs. Technological innovation by mechanical engineering includes information technology (IT)-based intelligent mechanical systems, mechanics and design innovations, and applied materials in nanoscience and nanotechnology. These new technologies that implant intelligence in machine systems represent an interdisciplinary area that combines conventional mechanical technology and new IT. The main goal of this Special Issue is to provide new scientific knowledge relevant to IT-based intelligent mechanical systems, mechanics and design innovations, and applied materials in nanoscience and nanotechnology

    Biodiversity and spatial ecology of arctic sponge grounds in the Nordic Seas

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    Sponge grounds are biogenic habitats formed by large structure-forming sponges in the deep-sea. They are biodiversity hotspots because they provide associated fauna a place of refuge, additional substratum, foraging areas, and can act as nursery grounds for many demersal fish. Sponge grounds have a global distribution, though there has been an increased focus in the North Atlantic in recent years due to the Horizon 2020 funded SponGES project. While there are a variety of sponge ground types based on their main sponge composition (monospecific and multispecific) or distribution (temperate, boreal, and arctic), there has been relatively little scientific focus on arctic sponge grounds, in terms of biodiversity, community ecology, and distribution. With potential imposing threats (e.g., climate change, bottom fishing, deep-sea mining) to arctic deep-sea communities such as arctic sponge grounds, there is a clear need to form a baseline understanding of these communities and their spatial ecology. The main aims of this thesis were to fill the current knowledge gaps of arctic sponge ground biodiversity and spatial ecology in the Nordic Seas. More specifically, this project aimed to: 1) describe the megafauna composition and diversity of arctic sponge grounds to improve on their current habitat classification; 2) examine biotic interactions occurring within the sponge grounds to evaluate the ecological services arctic sponge grounds provide; 3) investigate the spatial distribution of arctic sponge grounds and the characterising megafauna to identify how communities are distributed on a seascape and how megafauna are assembled within a habitat; and 4) explore the primary abiotic drivers that influence the distribution and community structure of arctic sponges grounds and their inhabitants in order to understand what conditions sponge grounds need to form and thrive. This thesis provides the first description of the oceanographic setting of Schulz Bank, a seamount on the Arctic Mid-Ocean Ridge used as a case study site for majority of the thesis and evaluates how the oceanographic conditions benefit the communities the seamount supports (Paper 1). The visual data collected from remotely operated vehicles (ROV) at various sites allowed us to test and refine annotation and statistical methodology that can be employed in future research for characterising benthic communities, exploring their distribution, and identifying their abiotic drivers (Papers 2–4). Furthermore, this thesis further highlights the potential of using AUVs for habitat mapping at small scales (<10 m) by identifying the fine-scale spatial patterns of arctic sponge ground fauna for the first time and visualizing how megafauna are assembled within their habitat (Paper 2). The work presented in the thesis forms a baseline understanding of the different types of arctic sponge grounds on Schulz Bank and builds on the limited scientific understanding of arctic sponge ground community and spatial ecology. Based on the results of this thesis, various new arctic megabenthic communities (biotopes), comprised of vulnerable marine ecosystem (VME) characterising taxa, were classified and are being proposed to the habitat classification system, European Nature Information System (EUNIS). These classifications can further improve habitat mapping and species distribution modelling capabilities of arctic megabenthic communities in the future. The extensive annotation of visual data identified key ecological roles that the sponge grounds provide to the associated megafauna, which can be further evaluated. Our work enhances the current understanding of abiotic drivers that influence arctic sponge ground distribution, although there is still a clear need to further build on this knowledge. Furthermore, our findings show that Schulz Bank is a prime candidate for protection due to its diverse and vulnerable communities, the ecological services the communities provide, and the relatively pristine condition the seamount is currently in. The work from this thesis has improved the understanding of sponge ground community and spatial ecology and developed tools and datasets that have been used in other work in the field. This thesis shows that arctic sponge grounds are important habitats in the Nordic Seas and highlights the need to form a baseline understanding of arctic benthic communities, especially in light of potential anthropogenic disturbances in the future.Svampebunner er biogene habitater dannet av store strukturdannende svamper i dyphavet. De har høyt biologisk mangfold fordi de gir tilhørende fauna et tilfluktssted, ekstra substrat, tilgang på mat og kan fungere som oppvekstområder for mange bunnfisk. Svampebunner har en global utbredelse, selv om det har vært et økt fokus i Nord-Atlanteren de siste årene på grunn av det forskningsprosjektet SpongES som var finansiert av EU-programmet Horisont2020. Selv om det finnes en rekke ulike svampebunner definert av sammensetningen av store svamper (monospesifikke og multispesifikke) eller utbredelsen (tempererte, boreale og arktiske), har det vært relativt lite vitenskapelig fokus på arktiske svampebunner når det gjelder biologisk mangfold, samfunnsøkologi, og distribusjon. Med potensielle fremtidige trusler (f.eks. klimaendringer, bunnfiske, dyphavsgruvedrift) mot arktiske dyphavssamfunn som svampebunner, er det et klart behov for å øke den grunnleggende forståelsen av disse samfunnene og deres romlige økologi. Hovedmålene med denne oppgaven var å fylle kunnskapshull om biologisk mangfold i arktisk svampebunn og romlig økologi i de nordiske hav. Mer spesifikt hadde dette prosjektet som mål å: 1) beskrive megafaunasammensetningen og mangfoldet av arktiske svampebunner for å forbedre deres nåværende habitatklassifisering; 2) undersøke biotiske interaksjoner som forekommer innenfor svampebunnene for å evaluere de økologiske tjenestene arktiske svampebunner tilbyr; 3) undersøke den romlige fordelingen av arktiske svampebunner og den karakteristiske megafaunaen for å identifisere hvordan samfunnet er fordelt på havbunnen og hvordan megafauna er utbredt innenfor habitatet; og 4) utforske de primære abiotiske drivkreftene som påvirker utbredelsen og samfunnsstrukturen til arktiske svampebunner og deres innbyggere for å forstå hvilke forhold svampebunner trenger for å dannes og trives. Denne oppgaven gir den første beskrivelsen av de oseanografiske forholdene ved Schulzbanken, et undersjøisk fjell på den arktiske midthavsryggen som er studieområdet for størstedelen av oppgaven, og evaluerer hvordan de oseanografiske forholdene er til nytte for samfunnene undersjøisk fjellet støtter (artikkel 1). De visuelle dataene samlet inn fra remotely operated vehicles (ROV) på forskjellige steder gjorde det mulig å teste og raffinere annotering og statistisk metodikk som kan brukes i fremtidig forskning for å karakterisere bunndyrsamfunn, utforske deres utbredelse og identifisere deres abiotiske drivere (artikkel 2–4). Videre fremhever denne oppgaven potensialet ved å bruke AUV-er for habitatkartlegging i liten skala (<10 m) ved å identifisere de finskala romlige mønstrene til arktisk svampebunnfauna for første gang, og visualisere hvordan megafauna er satt sammen i deres habitat (artikkel 2). Arbeidet som presenteres i avhandlingen danner en grunnleggende forståelse av de forskjellige typene av arktiske svampebunner på Schulzbanken og utvider den begrensede vitenskapelige forståelsen av arktisk svampebunnsamfunn og romlig økologi. Basert på resultatene av denne avhandlingen, ble ulike nye arktiske megabentiske samfunn (biotoper), som består av dyregrupper som karakteriserer Vulnerable Marine Ecosystems (VMEer), klassifisert og foreslått til habitatklassifiseringssystemet, European Nature Information System (EUNIS). Disse klassifiseringene kan ytterligere forbedre habitatkartlegging og artsfordelingsmodelleringsevner for arktiske megabentiske samfunn i fremtiden. Den omfattende annoteringen av visuelle data identifiserte viktige økologiske roller som svampebunnene har for den tilhørende megafaunaen. Avhandlingen forbedrer den nåværende forståelsen av abiotiske drivere som påvirker arktisk svampebunnfordeling, selv om det fortsatt er et klart behov for å bygge videre på denne kunnskapen. Videre viser funnene våre at Schulzbanken er en førsteklasses kandidat for beskyttelse på grunn av dets mangfoldige og sårbare samfunn, de økologiske tjenestene samfunnene leverer, og den relativt uberørte tilstanden havfjellet er i. Arbeidet i denne avhandlingen har forbedret forståelsen av svampebunnssamfunn og romlig økologi og utviklet verktøy og datasett som har vært brukt i annet arbeid på feltet. Denne oppgaven viser at arktiske svampebunner er viktige habitater i de nordiske hav og fremhever behovet for å danne en grunnleggende forståelse av arktiske bunndyrsamfunn, spesielt i lys av potensielle menneskeskapte forstyrrelser i fremtiden.Doktorgradsavhandlin

    Comparison of the vocabularies of the Gregg shorthand dictionary and Horn-Peterson's basic vocabulary of business letters

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    This study is a comparative analysis of the vocabularies of Horn and Peterson's The Basic Vocabulary of Business Letters1 and the Gregg Shorthand Dictionary.2 Both books purport to present a list of words most frequently encountered by stenographers and students of shorthand. The, Basic Vocabulary of Business Letters, published "in answer to repeated requests for data on the words appearing most frequently in business letters,"3 is a frequency list specific to business writing. Although the book carries the copyright date of 1943, the vocabulary was compiled much earlier. The listings constitute a part of the data used in the preparation of the 10,000 words making up the ranked frequency list compiled by Ernest Horn and staff and published in 1926 under the title of A Basic Writing Vocabulary: 10,000 Words Lost Commonly Used in Writing. The introduction to that publication gives credit to Miss Cora Crowder for the contribution of her Master's study at the University of Minnesota concerning words found in business writing. With additional data from supplementary sources, the complete listing represents twenty-six classes of business, as follows 1. Miscellaneous 2. Florists 3. Automobile manufacturers and sales companie

    Concepts and Approaches for Mars Exploration

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    Abstracts describe missions, mission elements or experiments for consideration in the 2005-2020 time frame. Also the technologies and the support necessary to achieve the results are discussed.NASA Headquarters; Lunar and Planetary Institutehosted by Lunar and Planetary Institute ; sponsored by NASA Headquarters, Lunar and Planetary Institute ; convener Scott Hubbard

    Towards a grammar of the senses: perception in Lushese (Olussese)

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    The thesis presents the grammar of the Eastern African Bantu language Lushese (Olussese), spoken in Uganda, and gives information on the historical background that caused the today´s highly endangered status of the language (chapters 1 & 2). Focussing on the semantics of the verbs of perception, the thesis presents the use and meaning of various linguistic means for expressing perception in general and further for the expression of physical, sensory, emotional and cognitive experience in Lushese (chapters 3-5). The findings in Lushese provide insights of the use of language in the light of social interaction and include information on the ways cultural and social values impact the choice of linguistic means (chapter 6). With respect to the theoretical issues concerning the language of perception the data in Lushese show that the way people speak about the environment and use language to express categories of perception are rather a matter of innate cultural interpretation regarding the human body and the environment than a matter of the human body and the environment as given by biological and/or physical conditions
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