139585 research outputs found
Sort by
A voyage-level ship performance modelling approach for the simulation of the Finnish-Swedish winter navigation system
No full textFunding Information: The research was supported by the Winter Navigation Research Board – a Finnish-Swedish cooperation co-funded by the Finnish Transport and Communications Agency , the Finnish Transport Infrastructure Agency , the Swedish Maritime Administration , and the Swedish Transport Agency under the projects WinterSim and W22-1 SIMNAV. The research also receives funding from the Finnish Transport Infrastructure Agency through the project ‘Development of winter navigation simulation model’ (agreement No. 2022.2379.1). Author 1 was also supported by the Academy of Finland project: Towards human-centered intelligent ships for winter navigation (Decision number: 351491). The corresponding author was supported by the Science and Technology Commission of Shanghai Municipality Project ( 23YF1419900 ). In addition, the authors would like to thank Aker Arctic Technology Inc for providing the sample ship database containing established h-v curves. Funding Information: The research was supported by the Winter Navigation Research Board – a Finnish-Swedish cooperation co-funded by the Finnish Transport and Communications Agency, the Finnish Transport Infrastructure Agency, the Swedish Maritime Administration, and the Swedish Transport Agency under the projects WinterSim and W22-1 SIMNAV. The research also receives funding from the Finnish Transport Infrastructure Agency through the project ‘Development of winter navigation simulation model’ (agreement No. 2022.2379.1). Author 1 was also supported by the Academy of Finland project: Towards human-centered intelligent ships for winter navigation (Decision number: 351491). The corresponding author was supported by the Science and Technology Commission of Shanghai Municipality Project (23YF1419900). In addition, the authors would like to thank Aker Arctic Technology Inc for providing the sample ship database containing established h-v curves. Publisher Copyright: © 2024 Elsevier LtdThe Finnish-Swedish winter navigation system plays an essential role in logistics to the ports surrounded by frozen sea in winter. Coordination of icebreakers is crucial to guarantee sufficient transit speed of merchant ships and minimize the waiting time. Simulation of the winter navigation system provides the opportunity to optimize the system performance and help the planning of future icebreaker fleets. For simulation, estimation of ship performance, such as the actual speed in ice, is essential. Calculation methods to estimate ship performance in such contexts are typically required to be of simple form without the need for heavy computation. Existing ship performance models embedded in route optimization algorithms and winter navigation simulations in the literature are often oversimplified. This paper proposes a systematic ship performance modelling approach which accounts for a wide range of parameters, such as ice condition and parameters, power variation and icebreaker assistance. The approach is validated against real ship voyages. The proposed approach is implemented into a simulation model which simulates the operation of merchant ships and icebreakers on the Baltic Sea. Analyses are conducted on the system level in terms of the waiting time of merchant ships needed for icebreakers as well as the energy consumption.Peer reviewe
Dissent, Humour, and Acceptance: Exploring Rural Emotions About Technological Change in England and Finland, 1890s‐1920s
No full textTechnological change at the dawn of the twentieth century was often rapid, with new technologies impacting both rural and urban areas. By taking a comparative approach to analysing technological change in the rural, this article compares emotional navigation in rural England and Finland using essay competitions collected between 1958 and 1964. The main findings illustrate how agricultural mechanization, milk-cream separators, and cars were highly contentious in Finland, whilst English writers comment on new machinery generally positively. Only the arrival of the car created tension in some writers, especially for women. Technological changes impacted genders and social classes differently. As the sources show, communities supported one another, but also created silences, sang songs, and told stories to exert control over who could benefit from what technology.Peer reviewe
Exploring the Impacts of Human-Robot Gender Match on Users’ Perceptions of Robots
No full textPublisher Copyright: © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.Numerous studies have explored human preferences for male versus female robots, producing inconsistent findings and varied explanations for the manifestation of gender bias towards robots. This study contributes to understanding how user gender and robot gender interact to influence users’ evaluations of robots by analyzing over 1100 survey responses on 23 robots, distinguished by their male and female appearances. The findings refute the existence of the same-gender or cross-gender effect. Specifically, we found a general preference for female robots over male robots. In addition, female users report the highest likeability scores for female robots compared to other human-robot gender combinations.Peer reviewe
Coupling of high ion transport efficiency in hydrogel electrolytes and interfacial fusion for performance enhancement in all-solid-state paper-based self-powered electrochromic devices with low-temperature tolerance
No full textPublisher Copyright: © 2025 The Royal Society of Chemistry.Self-powered electrochromic devices (ECDs) have gained considerable attention for applications such as smart labels, displays and rechargeable batteries, thanks to their dynamic balance between color display and energy storage capabilities. The electrochemical performance of existing ECDs, however, is often constrained by the conductivity of electrolytes, the contact interface between electrodes and electrolytes, and the severe intolerance of ECDs to low temperature environments. In this study, we couple two approaches. Firstly, we harness the Hofmeister effect to modulate the concentration of an ionic compound within the hydrogel electrolyte. This modulation enhances ion solvation and ionic conductivity, thereby facilitating internal ion transport within the self-powered ECD and accelerating the device's response time. Secondly, we illustrate how it is possible to capitalize on the designable properties of the substrate. Paper offers a unique controllable substrate structure, which can be readily modified in terms of surface micro-roughness, which, in turn, can be utilized during the forming of the gravure printed electrode. This novel optimization can improve the final surface morphology of the paper-based electrode, enhancing its surface area properties. This enhancement subsequently facilitates improved integration of the electrode interface with the hydrogel electrolyte, reducing interface impedance and increasing ion transport efficiency within the ECD. Combining this morphological effect with the increased ion solvation in the hydrogel electrolyte enables an improved electrochemical performance and cyclic stability, maintaining stability even at temperatures as low as −40 °C.Peer reviewe
Compressive behaviour and design of rectangular concrete columns strengthened with high strength thin-walled octagonal steel tube and sandwiched ECC layer
No full textPublisher Copyright: © 2024Traditional strengthening techniques like concrete jacketing and steel jacketing may no longer suffice to meet the demands of high-performance, efficiency, and low carbon footprint. This paper presents an experimental investigation on a novel strengthening method for reinforced concrete (RC) columns, using external thin-walled octagonal high strength steel tube and sandwiched ECC layers. The impacts of steel grade, sandwiched layer material, sandwiched layer thickness, tube aspect ratio, and ECC-concrete interface roughness on the failure mode, load-bearing capacity, and strain responses of the strengthened concrete columns were explored. Uniaxial compression tests results illustrated the effectiveness of the proposed strengthening technique in utilizing the compressive strength of the steel tube and the advantages of confinement. This method resulted in a notable enhancement in load-bearing capacity, ranging from 304 % to 814 %, with a modest increase in section size of 51 % to 140 %. Furthermore, a significant improvement of up to 24 % in strength was observed when comparing the strengthened column to its nominal strength. Design recommendations were provided based on the design approaches from GB 50936–2014, EN 1994-1-1:2004 and ANSI/AISC 360-22 for CFSTs. The results showed that the design approaches for circular CFSTs in EN 1994-1-1:2004 combined with the confinement coefficient for octagonal section could reasonably capture the compressive capacity of the strengthened columns.Peer reviewe
Becoming response-able together in research fieldwork
No full textPublisher Copyright: © 2025 selection and editorial matter, Michela Cozza, Anna Carreri, and Barbara Poggio; individual chapters, the contributors.In this chapter, we explore response-ability – our embodied ability to respond to others – in research fieldwork. Building on materials from an immersive coaching process of a leadership team, we elaborate on how the researcher-coach and the team negotiated becoming ‘response-able-together’ over time and how that supported the development of collective leadership. We focus on the affective intensities during the process, particularly moments where differences in ideas, rhythms, priorities, and abilities led to uncertainty and vulnerability, necessitating an ongoing negotiation of response-ability. We illustrate how response-ability in fieldwork may nurture reciprocal relations that arise from tensions instead of privileging consensus and/or unity. We further argue that response-able research can support organizational processes and practices that enhance individual and collective capacities to act, while counter-acting forms of affective contagion that work in disciplining and diminishing ways.Peer reviewe
Magnonic Fabry-Pérot resonators as programmable phase shifters
No full textPublisher Copyright: © 2025 Author(s).We explore the use of magnonic Fabry-Pérot resonators as programmable phase shifters for spin-wave computing. The resonator, composed of an yttrium iron garnet film coupled with a CoFeB nanostripe, operates through dynamic dipolar coupling, leading to wavelength downconversion and the formation of a magnonic cavity. Using super-Nyquist sampling magneto-optical Kerr effect microscopy and micromagnetic simulations, we demonstrate that these resonators can induce a π phase shift in the transmitted spin wave. The phase shift is highly sensitive to the magnetization alignment within the resonator, allowing for on-demand control via magnetic switching. This feature, combined with low-loss transmission, positions the magnonic Fabry-Pérot resonator as a promising component for reconfigurable magnonic circuits and spin-wave computing devices.Peer reviewe
Direction-agnostic gesture recognition system using commercial WiFi devices
No full textFunding Information: This work was supported by the National Natural Science Foundation of China under Grant 62071244, the Postgraduate Research & Practice Innovation Program of Jiangsu Province under Grant KYCX20_0717, and China Scholarship Council, China under Grant 202108320270. Publisher Copyright: © 2024 Elsevier B.V.In recent years, channel state information (CSI) has been used to recognize hand gestures for contactless human–computer interaction. However, most existing solutions require precision hardware or prior learning at the same angle both during training and for inference/training in order to achieve high recognition accuracy. This requirement is unrealistic for practical instrumentation, where the orientation of a subject relative to the RF receiver may be arbitrary. We present direction-agnostic hand gesture recognition utilizing commercial WiFi devices to overcome low accuracy in non-trained observation angles. To achieve equal conditions in all recognition angles, first of all, through the circular antenna arrangement to mitigate the impact of user direction changes. Then, the orientation of users is estimated by the Fresnel zone model. Finally, the feature mapping model of users in different orientations is established, and the gesture features in the estimated direction are mapped to the benchmark direction to eliminate the influence caused by the change of user orientation. Experimental results in a typical indoor environment show that WiNDR has superior performance, and the average recognition accuracy of five common gestures is 92.38%.Peer reviewe
Piikarbidikiekkojen valmistuksesta johtuvat kidevirheet ja epapuhtaudet
No full textPiikarbidi on piistä ja hiilestä koostuva puolijohdemateriaali. Ominaisuuksiensa ansiosta se soveltuu hyvin käytettäväksi esimerkiksi teho- ja optoelektroniikan sovelluksissa. Elektroniset sovellukset valmistetaan piikarbidikiekoille, joiden valmistusprosessi vaatii haastavat olosuhteet ja joiden valmistuksen aikana voi muodostua kidevirheitä ja päätyä epäpuhtauksia.
Tässä kirjallisuustutkimuksena toteutetussa kandidaatintyössä tavoitteena on selvittää, mitä kidevirheitä ja epäpuhtauksia piikarbidikiekkojen valmistuksessa muodostuu, miten ne vaikuttavat sovelluksiin ja kuinka yleisiä ne ovat.
Tässä työssä käsitellään kahdeksan yleisintä tai merkityksellisintä modifioidussa Lely-menetelmässä piikarbidikiekkoihin muodostuvaa virhetyyppiä: mikroputket, läpäisevät ruuvidislokaatiot, läpäisevät särmäsislokaatiot, basaalitason dislokaatiot, pinoamisvirheet, vieraan polytyypin kasvu, epäpuhtaudet ja pintavirheet. Työssä todetaan, että vaikutuksiltaan merkittäviä mikroputkia, läpäiseviä ruuvidislokaatioita ja pinoamisvirheitä esiintyy kiekoissa nykyisin vähän tai ei ollenkaan. Kuitenkin kiekoissa esiintyy edelleen muita virhetyyppejä, jotka heikentävät kiekkojen laatua ja niistä valmistettujen laitteiden suorituskykyä. Pintavirheisiin voidaan vaikuttaa käytettävällä kiekkojen sahausmenetelmällä ja muita virhetyyppejä voidaan vähentää parantamalla kasvuolosuhteita kiteen kasvatukselle optimaalisemmiksi.
Tulosten perusteella voidaan todeta, että piikarbidikiekkojen valmistusprosessi vaatii vielä kehittämistä, jotta saataisiin korkealaatuisempia kiekkoja käytettäväksi
Numerical implementation of the partial secular approximation and unified master equation in structured open quantum systems
No full textThe Markovian dynamics of open quantum systems is typically described through Lindblad equations, which are derived from the Redfield equation via the full secular approximation. The latter neglects the rotating terms in the master equation corresponding to pairs of jump operators with different Bohr frequencies. However, for many physical systems this approximation breaks down, and thus a more accurate treatment of the slowly rotating terms is required. Indeed, more precise physical results can be obtained by performing the partial secular approximation, which takes into account the relevant time scale associated with each pair of jump operators and compares it with the time scale arising from the system-environment coupling. In this work, we introduce a general code for performing the partial secular approximation in the Redfield equation for structured open quantum systems. The code can be applied to a generic Hamiltonian of any multipartite system coupled to bosonic baths. Moreover, it can also reproduce the unified master equation, which captures the same physical behavior as the Redfield equation under the partial secular approximation, but is mathematically guaranteed to generate a completely positive dynamical map. Finally, the code can compute both the local and global version of the master equation for the same physical problem. We illustrate the code by studying the steady-state heat flow in a structured open quantum system composed of two superconducting qubits, each coupled to a bosonic mode, which in turn interacts with a thermal bath. The results in this work can be employed for the numerical study of a wide range of complex open quantum systems.Peer reviewe