Browsing by Department "University of Vaasa"

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  • An Adaptive Denoising Algorithm for Online Condition Monitoring of High-Voltage Power Equipment
    (2020-10-21) Hussain, Amjad; Ahmed, Zeeshan; Shafiq, Muhammad; Zaher, Ashraf; Rashid, Zeeshan; Lehtonen, Matti
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Partial discharge (PD) diagnostic is an effective tool for condition monitoring of the high-voltage equipment that provides an updated status of the dielectric insulation of the components. Reliability of the diagnostics depends on the quality of the PD measurement techniques and the processing of the measured PD data. The online measured data suffer from various inaccuracies caused by external noise from various sources such as power electronic equipment, radio broadband signals and wireless communication, etc. Therefore, extraction of useful data from the on-site measurements is still a challenge. This article presents a discrete wavelet transform (DWT)-based adaptive denoising algorithm and evaluates its performance. Various decisive steps in applying DWT-based denoising on any signal, including selection of mother wavelet, number of levels in multiresolution decomposition and criteria for reconstruction of the denoised signals are taken by the proposed algorithm and vary from one signal to another withouta human intervention. Hence, the proposed technique is adaptive. The proposed solution can enhance the accuracy of the PD diagnostic for HV power components.
  • Can You Trust Your Pose? Confidence Estimation in Visual Localization
    (2020) Ferranti, Luca; Li, Xiaotian; Boutellier, Jani; Kannala, Juho
     Conference article in proceedings
    Camera pose estimation in large-scale environments is still an open question and, despite recent promising results, it may still fail in some situations. The research so far has focused on improving subcomponents of estimation pipelines, to achieve more accurate poses. However, there is no guarantee for the result to be correct, even though the correctness of pose estimation is critically important in several visual localization applications, such as in autonomous navigation. In this paper we bring to attention a novel research question, pose confidence estimation, where we aim at quantifying how reliable the visually estimated pose is. We develop a novel confidence measure to fulfill this task and show that it can be flexibly applied to different datasets, indoor or outdoor, and for various visual localization pipelines. We also show that the proposed techniques can be used to accomplish a secondary goal: improving the accuracy of existing pose estimation pipelines. Finally, the proposed approach is computationally light-weight and adds only a negligible increase to the computational effort of pose estimation.
  • CEO facial masculinity and bank risk-taking
    (2019-02-01) Ahmed, Shaker; Sihvonen, Jukka; Vähämaa, Sami
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    This paper uses Chief Executive Officer (CEO) facial features to examine the association between CEO masculinity and bank risk-taking. Given that high facial width-to-height ratio has been linked to high testosterone levels and masculine behavioral traits such as increased risk tolerance, aggression, and sensation seeking, we postulate a positive relationship between CEO facial masculinity and bank risk-taking. Consistent with this prediction, we document that banks led by CEOs with more masculine facial features are associated with more volatile stock returns and higher levels of idiosyncratic risk.
  • Cybersecurity in Accounting Research
    (2022) Haapamäki, Elina; Sihvonen, Jukka
     A3 Kirjan tai muun kokoomateoksen osa
  • Intermediation dilemmas in facilitated industrial symbiosis
    (2020-07-10) Patala, Samuli; Salmi, Asta; Bocken, Nancy
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Industrial symbiosis (IS) is a key paradigm for achieving circular economy among industrial firms. Achieving new IS projects often requires outside facilitation, and intermediaries can help solidify and expand existing IS networks. While various intermediary roles have been identified in the literature, less attention has been paid to the potential challenges that intermediaries might encounter in their activities. Based on the case of the national symbiosis network FISS, the Finnish Industrial Symbiosis system, this study investigates the dilemmas faced when organizing IS networks. It identifies openness and value demonstration dilemmas, which hinder intermediary-firm relations. It also identifies collaborative intermediation processes among intermediaries in seeking to uncover value, ensuring community embedding of new networks and selective integration of intermediation activities. These processes can help overcome the intermediation dilemmas. The results on the collaborative intermediation and its development over time contribute to research on facilitated IS and on intermediaries in sustainability transitions. For policy-makers, the study pinpoints the need for collaborative intermediation where both national and regional intermediaries are involved to ensure both economies of scale and flexibility.
  • A novel methodology for the path alignment of visual SLAM in indoor construction inspection
    (2021-07) Lu, Tao; Tervola, Sonja; Lü, Xiaoshu; Kibert, Charles J.; Zhang, Qunli; Li, Tong; Yao, Zhitong
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Path alignment is the process of mapping an indoor construction inspection path reconstructed by a visual SLAM system onto a 2D map with user interaction required to pinpoint at least two common tie points. In practice, more points are often needed due to path distortions and linear transformations, potentially resulting in reduced productivity. This paper proposes a methodology that combines two novel algorithms for the path alignment: (1) PCA_STAN_ALGO applies principal component analysis to remove path distortions caused by the xz plane of a camera coordinate system not being parallel to the floor plane; and (2) GRPX_TRANS utilizes a graphical user interface to facilitate the path alignment. The proposed methodology enables the users to utilize just two tie points for successful path alignment. An experimental study showed that applying both PCA_STAN_ALGO and GRPX_TRANS saved about 50% in time compared to using only GRPX_TRANS, a result of needing minimal moving points.
  • Perceptions of Language (Mis)fit at a Multilingual Workplace
    (2020) Järlström, Maria; Piekkari, Rebecca; Pilke, Nina; Turpeinen, Hanna
     A3 Kirjan tai muun kokoomateoksen osa
    Based on a case study we identify sources and contexts of linguistic challenges that academic and university services staff perceive at a multilingual workplace. Some of these challenges produce subjective perceptions of language misfit—a concept that refers to a sense of inadequacy in the social context through which professionals communicate specialized knowledge. Professionals who experience misfit have limited language skills or their skills are inconsistent with the language policies and practices of the university and/or the region where the university is embedded. Our findings suggest that language misfit and fit form a dualistic pair of concepts which is dynamic and context-specific. We offer a contribution to person-environment (mis)fit research and the study of multilingual organizations, which has to date focused on private, for-profit organizations.
  • TBPos
    (2023) Fahim, Masud; Söchting, Ilona; Ferranti, Luca; Kannala, Juho; Boutellier, Jani
     Conference article in proceedings
    Image based localization is a classical computer vision challenge, with several well-known datasets. Generally, datasets consist of a visual 3D database that captures the modeled scenery, as well as query images whose 3D pose is to be discovered. Usually the query images have been acquired with a camera that differs from the imaging hardware used to collect the 3D database; consequently, it is hard to acquire accurate ground truth poses between query images and the 3D database. As the accuracy of visual localization algorithms constantly improves, precise ground truth becomes increasingly important. This paper proposes TBPos, a novel large-scale visual dataset for image based positioning, which provides query images with fully accurate ground truth poses: both the database images and the query images have been derived from the same laser scanner data. In the experimental part of the paper, the proposed dataset is evaluated by means of an image-based localization pipeline.
  • A transition from goods-dominant to service-dominant exchange logic in a B2B relationship
    (2019) Makkonen, Hannu; Saarikorpi, Mervi; Rajala, Risto
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    The study complements the dominant interpretations of positioning in marketing management research by introducing a relational perspective on positioning in the industrial markets. Instead of focusing on products, brand, or company image only, the study focuses on the exchange logic of the relationship. The study suggests that exchange logic of the relationship i.e. relationship logic comprises a fundamental unit of positioning in the industrial markets. Accordingly, the study defines that relationship logic stems from the dynamics of the action, structural and management dimensions that integrate the buyer and supplier organizations into their mutual relationship. Through a longitudinal empirical study of a relationship between buyer and supplier companies in the food service industry, we show how the relationship has been repositioned from goods-dominant to service-dominant relationship logic. The results reveal elements on the action and structural dimensions, their mutual dynamics and managerial reframingactions that catalyze changes in the relationship logic, i.e., reposit the relationship. The results are organized into a framework that delineates the relationship positioning dimensions, and discusses the implications of such relationship positioning to guide further academic research and managerial practice.
  • Who cares about sanctions? Observations from annual reports of European firms
    (2022-05-04) Davydov, Denis; Sihvonen, Jukka; Solanko, Laura
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    This paper uses textual analysis to examine how European corporations assess sanctions in their annual reports. Using observations from a panel of almost 11,500 corporate annual reports from 2014 to 2017, we document significant cross-country variation in how firms perceive Russia-related sanctions, even after controlling for many firm-level characteristics, sectoral differences, and time trends. The cross-country differences also remain for sentiments about sanctions and contexts in which sanctions are mentioned. We also examine the role of macroeconomic linkages in explaining these differences. We show that Russia’s inward and outward FDI stocks and high levels of imports and exports with Russia explain about half of the cross-country variation, leaving a nontrivial share of variation unexplained.