| 1. |
- Ahlin, Kjell, et al.
(author)
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Comparing Road Profiles with Vehicle Perceived Roughness
- 2004
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In: International Journal of Vehicle Design. - Geneva, Switzerland : Inderscience Enterprises. - 0143-3369 .- 1741-5314. ; 36:2-3, s. 270-286
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Journal article (peer-reviewed)abstract
- Accurate road profiles are useful in vehicle design, such as for simulation of durability and ride quality. Laser/inertial profilometers typically record I mm wide profiles. The question is how well such a profile matches perceived vehicle wheel roughness. The objective here was to create a more representative wheel track longitudinal profile. Simulated and measured wheel vibration was compared on a 6km long road. Simulations were made for several definitions of the profile. Results for single laser sensor profiles showed reasonable likeness to truck perceived roughness. By far the best likeness (14.5% better) was achieved when the profile was based on triangular 25%-50%-25% weighted data from three sensors in the wheel track. Clearly, vehicle engineers can benefit from using multiple laser profile sensors, instead of a single sensor. This will improve test accuracy, thus reducing vehicle design project lead times and costs.
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| 2. |
- Albinsson, Gunilla, et al.
(author)
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I vardagen konstrueras jämställdhet
- 2004
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Reports (peer-reviewed)abstract
- Studiens övergripande syfte är att fördjupa förståesen för jämställdhet inom en kommunal förvaltning utifrån tre teoretiska utgångspunkter; teoretiska perspektiv på organisation, könsperspektiv samt teorier om makt. I fokus står en grupp yrkesverksamma kvinnor och män. Vid genomförandet av den empiriska studien används observationer och kvalitativa intervjuer. När ett könsperspektiv är utgångspunkt vid studier av en organisation framträder könets betydelse på såväl struktur- som individnivå. I resultatet illustrerar en bild av både hinder och möjligheter för en jämställd organisation. De hinder som finns är hierarki, könssegregering, kunskapsbrist, kulturell kod samt språkbruk. Möjligherna utgörs av styrning, kunskap och metoder.
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| 3. |
- Andrén, Linus, et al.
(author)
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Active Noise Control Experiments in a Fork-lift Truck Cabin
- 2004
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Conference paper (peer-reviewed)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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| 4. |
- Andrén, Linus, et al.
(author)
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Actuator placements and Variations in the Control Path estimates in the Active Control of Boring Bar Vibrations
- 2004
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Conference paper (peer-reviewed)abstract
- A classical example of chatter prone machining is the boring operation. Turning under conditions with high vibrations in the cutting tool deteriorates the surface finish and may cause tool breakage. Severe noise is also a consequence of the high vibration levels in the boring bar. Active control is one possible solution to the noise and vibration problem in boring operations. In boring operations the boring bar usually have vibration components in both the cutting speed and the cutting depth direction. The introduction of the control force in different angles in between the cutting speed and the cutting depth directions have been investigated. Furthermore, control path estimates produced when the active boring bar was not in contact with the workpiece and during continuous cutting operation are compared. Experimental results indicate that the control force should be introduced in the cutting speed direction. Although the vibrations are controlled in just the cutting speed direction the vibrations in the cutting depth direction are also reduced significantly.
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| 5. |
- Andrén, Linus, et al.
(author)
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Identification of Dynamic Properties of Boring Bar Vibrations in a Continuous Boring Operation
- 2004
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In: Mechanical systems and signal processing. - : Academic Press. - 0888-3270 .- 1096-1216. ; 18:4, s. 869-901
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Journal article (peer-reviewed)abstract
- Vibrations in internal turning operations are usually a cumbersome part of the manufacturing process. This article focuses on the boring bar vibrations. Boring bar vibrations in alloyed steel, stainless steel and cast iron have been measured in both the cutting speed direction and the cutting depth direction with the aid of accelerometers. The dynamic response of a boring bar seem to be a time varying process that exhibits non-linear behaviour. The process is influenced by non-stationary parameters that are not under the control of the operator or experimenter. The vibrations are clearly dominated by the first resonance frequency in one of the two directions of the boring bar. The problem with force modulation in rotary machinery, which appears as side band terms in the spectrum, is also addressed. Furthermore, the resonance frequencies of the boring bar are correlated to an Euler-Bernoulli beam model.
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| 6. |
- Andrén, Linus, et al.
(author)
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Identification of Motion of Cutting Tool Vibration in a Continuous Boring Operation : Correlation to structural Properties
- 2004
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In: Mechanical systems and signal processing. - : Academic Press, UK. - 0888-3270 .- 1096-1216. ; 18:4, s. 903-27
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Journal article (peer-reviewed)abstract
- The internal turning operation has a history of being a cumbersome metal working process as vibration in boring operations is usually inevitable. In this article, the deflection shapes and/or mode shapes as well as the resonance frequencies of a boring bar have been put under scrutiny. Three methods have been used in order to investigate dynamic properties of a clamped boring bar: a theoretical Euler-Bernoulli beam model, an experimental modal analysis and an operating deflection shape analysis. \\ The results indicate a correlation between the shapes of the deflection shapes and/or mode shapes produced by the three different analysis methods. On the other hand, the orientation of the forced deflection shapes and/or mode shapes and the resonance frequencies demonstrates differences between the three methods. During continuous cutting, it is demonstrated that the bending motion of the first two resonance frequencies is to a large extent in the cutting speed direction.
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| 7. |
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| 8. |
- Bai, Guohua
(author)
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A Sustainable Information System for e-home Services
- 2004
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Conference paper (peer-reviewed)abstract
- E-home related home-services (including homecare and home healthcare) in China is urgently needed. The population of aged people over 80 is increasing 5% every year in China, and to year 2050, one fourth of whole population or 0.4 billions people in China are aged staying at home. Meanwhile the government cannot afford with a national elderly care system like most western countries as Sweden. This is because China has had one-child/one-family policy since 1970’s, and this radical policy has made China step in aged society very quickly within only 20 years, while the same process took 40-80 years in western countries. Even worse, China becomes aged society when the country is still poor and under developing with GDP per capita less than 1000$, comparing to western countries with 5000 – 10000 $ when they became aged society. E-home provides China with a unique, and maybe the most effective solution to the problem. By applying effective IT&C at home, elder people are facilitated to manage their own daily life. If needed, they can always call help from their collective service centre that is located in their resident area and the collective service centre can provide with both homecare (cleaning, shopping, reparation, baby care etc.) and home healthcare (legitimate medical care). Elder people can be also monitored (if wished by all partners) both at home and out door by bearing sensors that can send singles directly to related care providers (including their children and relatives if wished). E-home will greatly increase the security of elder people, release great worry from both their children and elder people themselves, and can be afford by most people. However, e-home is more than just a technical problem, and it needs a systemic way and social-psychological study how to design e-home system. In the end, e-home system must provide with needed services to residents. I will introduce IMIS project ´Integrated Mobile Information System for Home Healthcare’ financed by Swedish Agency for Innovative Systems (VINNOVA). This project will continue to 2006, and one of the outputs will be a sustainable software platform which is based on a systemic study of social psychological factors involved in the home healthcare. I will provide with some Swedish experiences and the so called ‘Scandinavia Approach’ in conducting such complex system to my colleagues in China, and I hope the IMIS project will be also developed in China based up on some feasibility and desirability studies with some Chinese colleagues.
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| 9. |
- Bai, Guohua
(author)
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A Sustainable Platform for E-services System Design
- 2004
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In: Journal of Systems Science and Systems Engineering. - Beijing : Springer Science + business Media. - 1004-3756 .- 1861-9576. ; 13:No.4
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Journal article (peer-reviewed)abstract
- By integrating system thinking and social psychology, this paper presents an Activity System Theory (AST) approach to the platform design of e-service systems in general, and e-healthcare systems in specific. In the first part, some important principles of AST and a sustainable model of human activity system are introduced. Then a project ‘Integrated Mobile Information System for Healthcare (IMIS)’ is presented to demonstrate how to construct a comprehensive platform for various complex e-service systems based on the sustainable model of AST. Our research focused on the complex e-healthcare system in Sweden, and the results showed that the model of AST can provide the designers of e-service system with a comprehensive and sustainable platform for designing various kinds of e-service system
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| 10. |
- Bai, Guohua
(author)
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Activity System Theory Approach to Healthcare Information System
- 2004
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Conference paper (peer-reviewed)abstract
- Healthcare information system is a very complex system and has to be approached from systematic perspectives. This paper presents an Activity System Theory (ATS) approach by integrating system thinking and social psychology. First part of the paper, the activity system theory is presented, especially a recursive model of human activity system is introduced. A project ‘Integrated Mobile Information System for Diabetic Healthcare (IMIS)’ is then used to demonstrate a practical application of the Activity System Theory especially in constructing healthcare information system. Our conclusion is that the activity system model can provide the service system designers with a comprehensive and integrated framework for designing healthcare information system in specific, and for designing various kinds of service systems in general.
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