| 1. |
- Andrén, Linus, et al.
(författare)
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Active Noise Control Experiments in a Fork-lift Truck Cabin
- 2004
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Konferensbidrag (refereegranskat)abstract
- High comfort for the driver in working vehicles is an important feature as well as a demand from the drivers. Low noise level is an essential factor for the manufacturer to maintain a high standard and comfort of vehicles. In many cases the noise inside the cabin can be related to the engine orders. Hydraulic pumps and fans are also related to the engine but not necessarily integers of the engine order. Passive absorbers are not suitable for the lowest frequencies and one approach is to use an active noise control system to solve the noise problem at low frequencies. In the present experiment loudspeakers were mounted inside the cabin of a fork lift-truck to produce the secondary noise field. To sense the residual noise, microphones were installed close to the driver's head. The aim is to create a zone of reduced noise around the head. Since a large portion of the noise inside the cabin can be related to the engine, an active control system based on a feedforward solution is possible. Experimental results from a feedforward solution of active noise control in a fork-lift truck cabin show that the noise level in the low frequency region can be reduced significantly.
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| 2. |
- Borgh, Markus, 1983-, et al.
(författare)
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A Personal Voice Analyzer and Trainer
- 2010
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Konferensbidrag (refereegranskat)abstract
- This paper presents a personal voice analyzer and trainer that allow the user to perform four daily exercises to improve the voice capacity. The system grades how well the user is performing the exercises by analyzing the duration, the intensity and the pitch of the user’s voice.
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| 3. |
- Claesson, Lena, et al.
(författare)
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Expert Competence in Remote Diagnostics : Industrial Interests, Educational Goals, Flipped Classroom & Laboratory Settings
- 2018
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Ingår i: Online Engineering & Internet of Things. - Cham : Springer. - 9783319643526 - 9783319643519 ; , s. 438-451
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Konferensbidrag (refereegranskat)abstract
- The manufacturing industry are dependent of engineering expertise. Currently the ability to supply the industry with engineering graduates and staff that have an up-to- date and relevant competences might be considered as a challenge for the society. In this paper an education approach is presented where academia - industry - research institutes cooperate around the development and implementation of master level courses. The methods applied to reach the educational goals, concerning expert competence within remote diagnostics, have been on site and remote lectures given by engineering, medical and metrology experts. The pedagogical approach utilized has been flipped classroom. The main results show that academic courses developed in cooperation with industry requires flexibility, time and effort from the involved partners. The evaluation interviews indicate that student are satisfied with the courses and pedagogical approach but suggests more reconciliation meetings for course development. Labs early in the course was considered good, and division of labs at the system and the component level. However further long- term studies of evaluation of impact is necessary.
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| 4. |
- Claesson, Lena, 1964-
(författare)
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Remote laboratories in STEM education : Strategies and methods for implementation
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- During a substantial part of their time young people of today live in an online world. The medial evolution has also influenced education and today much research work concerns the transfer of the physical world into the online one. One example is laboratories in science, technology, engineering, and mathematics (STEM) education that are available in online rooms. They enable students to be at home in front of a computer and on-screen watch and operate the physical equipment in the laboratory at school. It is a general agreement that laboratory lessons are necessary in subjects such as physics, chemistry and biology. Physical experiments provide a great way for students to learn more about nature and its possibilities as well as limitations. Experimental work can be provided by laboratories in three different categories; 1) hands-on, 2) remote and 3) simulated.This thesis addresses how to implement remote laboratories as a teaching methodology. It presents examples of upper secondary school students’ experimental work and their evaluation of remote laboratories regarding usability, sense of reality and technical problems. In order to gain a better understanding of the situation and needs regarding laboratory activities in an upper secondary school, eight physics teachers were interviewed at six different schools. Furthermore, 165 upper secondary school students answered a questionnaire survey regarding subject preferences, program choices, views on technology and self-ability, and their approach to technology and technology-related situations. This thesis also describes another education approach where academia, industry, and research institutes cooperate around the development and implementation of master level courses. The pedagogical approach utilized in these master level courses has been flipped classroom.In this thesis, the usage of remotely controlled laboratories in physics education at an upper secondary school and a university are addressed. The main objective of this project is to investigate the feasibility of using the Virtual Instruments System in Reality (VISIR) technology for remotely controlled laboratories, developed at Blekinge Institute of Technology, in upper secondary schools. The laboratory setup can be shared and utilized almost 24/7, thus reducing the associated costs and eliminating time restrictions.
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| 5. |
- Gradolewski, Dawid, et al.
(författare)
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A Wavelet Transform-Based Neural Network Denoising Algorithm for Mobile Phonocardiography
- 2019
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Ingår i: Sensors. - : MDPI. - 1424-8220. ; 19:4
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Tidskriftsartikel (refereegranskat)abstract
- Cardiovascular pathologies cause 23.5% of human deaths, worldwide. An auto-diagnostic system monitoring heart activity, which can identify the early symptoms of cardiac illnesses, might reduce the death rate caused by these problems. Phonocardiography (PCG) is one of the possible techniques able to detect heart problems. Nevertheless, acoustic signal enhancement is required since it is exposed to various disturbances coming from different sources. The most common denoising enhancement is based on the Wavelet Transform (WT). However, the WT is highly susceptible to variations in the noise frequency distribution. This paper proposes a new adaptive denoising algorithm, which combines WT and Time Delay Neural Networks (TDNN). The acquired signal is decomposed by means of the WT using the coif five-wavelet basis at the tenth decomposition level and then provided as input to the TDNN. Besides the advantage of adaptive thresholding, the reason for using TDNNs is their capacity of estimating the Inverse Wavelet Transform (IWT). The best parameters of the TDNN were found for a NN consisting of 25 neurons in the first and 15 in the second layer and the delay block of 12 samples. The method was evaluated on several pathological heart sounds and on signals recorded in a noisy environment. The performance of the developed system with respect to other wavelet-based denoising approaches was validated by the online questionnaire.
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| 6. |
- Gradolewski, Dawid, 1988-
(författare)
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Sensors and Algorithms in Industry 4.0 : Security and Health Preservation Applications
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Globalisation and technological digitisation have triggered an Industry 4.0. revolution. The core of this revolution is autonomisation of complex processes, which require expert knowledge. The technical foundations of Industry 4.0 are IoT, Big Data and AI technologies. Nowadays, autonomous systems are widely used to increase human and environmental safety and to prevent health degradation. Such non-industrial, life related applications demand high reliability as well as precision and accuracy, which challenge engineering science. The thesis objective is to provide suitable solutions for non-invasive, automated, and autonomous systems used for life protection and health maintenance. The proposed solutions enable non-invasive measurements by means of vision and acoustic sensors. The presented methods and systems are designed based on an analytical assessment of existing technologies and algorithms. New hardware solutions, signal and data processing methods, as well as classification and decision-making algorithms are proposed. Where required, additional customisations and modifications are applied. The systems and methods presented have been modelled and rigorously validated, and subsequently implemented and verified in a real environment. The scope of the thesis includes the assessment of functional requirements, precision, accuracy and reliability of life-related technological systems. It covers an analytical evaluation of proposed methods and algorithms of filtration, feature extraction, also detection, localization, identification, and classification of objects. The application fields are health monitoring, nature observation and facilitating collaborative frameworks in modern factories. The thesis specifically focuses on methods and algorithms of autonomous decision making concerning the risk of heart disease, the threat of fatal collision of rare birds with man-made structures and the prevention of accidents in modern robotised factories. It also deals with the implementation of the Industry 4.0 fundamentals, which are smart sensing, IoT and AI methods optimised to improve the system performance in a broad sense. The applied distributed computing method and machine-to-machine communication are aimed at limiting the data stream at an early stage of the decision-making process, and thus ensure the system’s cost-effectiveness. From the thesis, one can understand how the Industry 4.0 paradigm can contribute to autonomisation of compound processes and to increase system performance, without compromising its affordability.The thesis is divided into two parts. The first, Prolegomena provides an overview of the sensors and algorithms applicable to industrial safety along with human health and nature preservation. This part also visualizes the relationships and interactions among the articles comprising the second part named Papers. In general, each of the enclosed six papers deals with the problem of autonomisation of complex processes in real-time and in a regular environment.
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| 7. |
- Håkansson, Lars, et al.
(författare)
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Chapter 78 Machine Tool Noise, Vibration and Chatter Prediction and Control
- 2005
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Ingår i: HANDBOOK OF NOISE AND VIBRATION CONTROL. - New York : To be published by by John Wiley & Sons.
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- A frequent problem in the manufacturing industry today is the vibrations or chatter induced by metal cutting, e.g. turning, milling and boring operations. Vibrations in boring operations or internal turning operations, for example,are inevitable and constitute a major problem for the manufacturing industry. Tool vibrations in metal cutting affect the result of machining, particularly the surface finish. Furthermore, tool life is correlated with the degree of vibration and acoustic noise introduced. Generally, tool vibrations are related to a low-order bending mode of, for example, the tool holder shank in external turning, the boring bar in internal turning, spindle-cutter assembly in milling, etc. Tool chatter or vibration problems in internal turning or milling may be reduced, for example, by using boring bars and milling adapters with passive tuned dampers. These are usually manually tuned to increase the dynamic stiffness of the boring bar or milling adapter at one of the eigenfrequencies of its low-order bending modes. Active control approaches for the attenuation of the bending motion of boring bars, tool holder shanks and spindle-cutter assembly in milling have been developed; such approaches involve both adaptive and time-invariant feedback control. In addition, prediction and control methods for controlling cutting data to maintain stable cutting, i.e. to avoid cutting data resulting in chatter, have been developed.
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| 8. |
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| 9. |
- Håkansson, Lars, et al.
(författare)
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NOISE CANCELLING HEADSETS FOR SPEECH COMMUNICATION
- 2002
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Ingår i: Noise Reduction in Speech Applications. - Boca Raton, Florida : CRC Press. - 0849309492 ; , s. 305-327
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Headsets for speech communication are used in a wide range of applications. The basic idea is to allow hands-free speech communication, leaving both hands available for other tasks. One typical headset application is aircraft pilot communication. The pilot must be able to communicate with personnel on the ground and at the same time use both hands to control the aircraft. Communication headsets usually consist of a pair of headphones and a microphone attached with an adjustable boom. Headphone design varies widely between different manufacturers and models. In its simplest form, the headphone has an open construction providing little or no attenuation of the environmental noise. In headsets designed for noisy environments, the headphones are mounted in ear cups with cushions that provide some attenuation. The microphone is primarily designed to pick up the speech signal, but if the headset is used in a noisy environment, the background noise will also be picked up and transmitted together with the speech. As a consequence, speech intelligibility at the receive end will be reduced, possibly to zero. To increase the speech-to-noise ratio, it is common to use a directional microphone that has a lower sensitivity to sound incident from other directions than the frontal direction. In addition to this, the microphone electronics are usually equipped with a gate function that completely shuts off the microphone signal if its level drops below a threshold value. The purpose of the gate is to open the channel for transmission only when a speech signal is present. Headsets are frequently used in noisy environments where they suffer from problems of speech intelligibility. Even if an ear-cup type headset is used, the attenuation is relatively poor for low frequencies. Low frequency noise has a masking effect on speech, which significantly reduces the speech intelligibility. Several cases have been reported in which the sound level of the communication signal was increased to hazardous levels by the user to overcome this low frequency masking effect [1,2]. Ear exposure to the communication system resulted in hearing damage, such as hearing loss, tinnitus and hyperacusis.
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| 10. |
- Jachimzcyk, Bartosz, 1988-, et al.
(författare)
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IoT-based dairy supply chain : An ontological approach
- 2021
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Ingår i: Elektronika ir Elektrotechnika. - : Kauno Technologijos Universitetas. - 1392-1215 .- 2029-5731. ; 27:1, s. 71-83
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Tidskriftsartikel (refereegranskat)abstract
- Emerging digital transformation in industry is noticeable among others in Supply Chain Management (SCM). For instance, applying new-generation digitalized technologies in the Dairy Supply Chain (DSC) enables an increase of manufacturing productivity, improves planning and forecasting, and also enhances competitive capabilities according to Industry 4.0 assumptions. It is worth mentioning, that in modern DSC, high visibility of raw materials, components, products, and processes by all contributors on all stages of DSC is crucial. This article focuses on the transparency aspect of the DSC supported by IoT-based technologies enabling interoperability among all DSC participants. The paper addresses the problem of effective integration of heterogeneous data sources, i.e., deployed new technological IoT solutions with traditional SCM systems and a third-party software component. The main objective of this report is to propose the IoT-based DSC model comprising four chain stages: milk production, milk transportation, milk processing, and dairy products distribution. Moreover, the comprehensive DSC domain ontology as a knowledge model is formulated and described. The ontology aims on improvement of the DSC management efficiency by facilitating interoperability within DSC. The applicability of the proposed ontological model is verified using a sustainable-oriented case study, which estimates the environmental footprint at the milk transportation stage of the DSC. © 2021 Kauno Technologijos Universitetas. All rights reserved.
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