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The paper deals with the low-speed impact of rigid bodies.The elasticity and damping forces,acting on a body during the impact,depend on the physical properties of the material;in this work these forces are considered according to...
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The paper deals with the low-speed impact of rigid bodies.The elasticity and damping forces,acting on a body during the impact,depend on the physical properties of the material;in this work these forces are considered according to the Kelvin-Voigt,Bingham and Maxwell models of the medium.New models of the forces,acting during the impact,are elaborated.Numerical solutions of the equations for various impact forces are obtained.
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This paper deals with modeling and analysis of an impact system, which is composed of ball and plane. An impact model considering both duration of impact and energy loss is proposed. The Resultant force due to impact is formulated...
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This paper deals with modeling and analysis of an impact system, which is composed of ball and plane. An impact model considering both duration of impact and energy loss is proposed. The Resultant force due to impact is formulated by introducing a complex stiffness coefficient in Hertz's contact theory. From the expression for the resultant force, the impact system is modeled by both a nonlinear spring and a nonlinear dashpot. The characteristics of the nonlinear spring is expressed by using Hertz's theory, and that of the nonlinear dashpot is expressed by a function of the displace- ment and the velocity. The model parameters are determined by the configuration, the material value and the coefficient of restitution in the impact system. Experimellt and simulation are carried out to demonstrate the accuracy of the proposed model, and good agreement is shown.
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Purpose-One of the binding commitments under the Trans-Pacific Partnership Agreement is the extension of the copyright term to 70 years after the death of the author. This paper reports the preliminary findings of a research on th...
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Purpose-One of the binding commitments under the Trans-Pacific Partnership Agreement is the extension of the copyright term to 70 years after the death of the author. This paper reports the preliminary findings of a research on the potential impact of the extension of copyright term on the music industry in Malaysia. As Malaysia is a user and net importer of intellectual property, it is feared that extending the copyright term will likely impede incentives for the creation of new contents, increase the cost of licensing/ royalties, diminish the choice and creativity of film and music industry and increase royalty payments abroad. The purpose of this study is to determine whether the commercial lifespan of copyright works is long enough. Design/methodology/approach - Using a qualitative research method, in-depth interviews were carried out with key industry players between June and September 2015 to collect relevant information from the industry. The information obtained was analysed to gauge the market standing of the local music industry and how the proposed extension would bolster their financial and market power. The paper does not intend to explore the legal implications from the retrospective extension of copyright term and data on illegal use and piracy. The findings of the research will be purely drawn from the non-structured interviews and information gathered from respondents. Findings - The paper concludes that there is not enough evidence to support the notion that the copyright extension will be economically advantageous to the local music industry. Research limitations/implications - The feedback from the interviews, although cannot be generalised to be considered as representing the whole music industry in Malaysia, can nevertheless be taken as preliminary conclusions and an eye-opener to the quest for concrete support in the debate for the extension of the copyright term in Malaysia. The paper also does no explore the legal implications from the retrospective extension of copyright and data on illegal use and piracy. Practical implications - In conclusion, more studies need to be conducted to understand the dynamics and needs of the music market in Malaysia for the extension of the copyright term to be really beneficial to them. As this study is only conducted using a qualitative research method, using open-ended and in-depth interview techniques on a small group of respondents, there may be a need to embark on empirical research with proper execution of survey instruments to a larger group of respondents. Social implications - The music industry is chosen as the case study because it may develop into a potential export interest. The music industry as a small component of the larger "creative industry" has been identified as one of the new economic drivers under the Tenth Malaysia Plan. Originality/value - The paper was first presented at the ATRIP Congress 2015 at Cape Town on 27th September 2015. The paper has not been published. No studies have been done on the possible implications of copyright extension term on the music industry in Malaysia before.
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Purpose Bariatric surgery is on the rise worldwide. With the desired weight loss after bariatric surgery, patients frequently develop massive skin flaps resulting in the need of abdominoplasty. In these patients, this surgical tec...
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Purpose Bariatric surgery is on the rise worldwide. With the desired weight loss after bariatric surgery, patients frequently develop massive skin flaps resulting in the need of abdominoplasty. In these patients, this surgical technique is frequently associated with perioperative complications. Strategies to minimize complications are sought after. The objective of our study was to compare two different dissection techniques and their impact on postoperative outcome.Methods We included 66 patients in our study who underwent abdominoplasty after massive weight loss following bariatric surgery. In group 1, abdominoplasty was performed using the conventional technique of diathermia (n = 20). In group 2, abdominoplasty was performed using LigaSure Impact? (n = 46). The duration of the surgical procedure and perioperative complications were recorded as primary endpoints. Secondary endpoints were length of hospital stay and assessment of additional risk factors.Results Baseline characteristics were comparable between groups. The duration of surgery was significantly shorter in group 2. Postoperative complications were significantly less frequent in group 2 (p = 0.0035). Additional risk factors, e.g., smoking and diabetes mellitus, were not associated with increased rates of perioperative complications.Conclusions The choice of technical device for dissection in abdominoplasty alone will not guarantee minimized complication rates. Yet, the utilization of LigaSure Impact? in refined surgical techniques may facilitate reduced rates of complications, especially wound infections, and a shortened duration of surgery.
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The development of communication technology, radar, material processing, etc. stimulates the creation of powerful generators of microwave radiation with nanosecond pulse duration. A new method for generating microwave pulses of na...
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The development of communication technology, radar, material processing, etc. stimulates the creation of powerful generators of microwave radiation with nanosecond pulse duration. A new method for generating microwave pulses of nanosecond duration is proposed. This method is based on the property of the redistribution of charges in the coaxial line with a multi-element core. The paper takes into account the time delay of fuse switching. Pulse power increases with delays of up to 5 ns. Pulse parameters depend on the profile of a multi-element core generator. On the criterion of maximum generator power the parameters of multi-element generator core construction are optimized. In view of the analysis pulse generator construction, which consists of four sections, has been created and tested. As a result, studies have shown that under the optimization of generator construction parameters the generator gain increases in power by 11 times.
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We describe an optical fibre-based method to estimate impact force and collision duration using time measurements recorded from acoustic signals of a table tennis ball bouncing on a table. The technique combines measurements obtai...
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We describe an optical fibre-based method to estimate impact force and collision duration using time measurements recorded from acoustic signals of a table tennis ball bouncing on a table. The technique combines measurements obtained from a polarisation dependent optical fibre sensor with graphical analysis and kinetics through numerical calculations. The presented coefficient of restitution (COR), collision time, impact force, and elastic deformation during each bounce of the table tennis ball were obtained using corresponding time series measurements and numerical analysis. A peak impact force of 38.4 N was estimated for a ball of mass 2.83 g and 39.7 mm diameter dropped from a height of 31.5 cm. The impact duration for the associated bounce was 0.68 ms with a centre of gravity shift of 0.40 mm and COR of 0.88. While the observed results are unique to the ball and table surface, the approach is an attempt to fully quantify collision parameters from basic measurement and instrumentation applicable to undergraduate students. The sensor developed in this paper finds application in sports performance monitoring, infrastructural health early warning systems and pressure sensitive manufacturing processes.
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Objective. To examine the agreement between objective (accelerometer) and subjective measures of sleep in fibromyalgia women (FW) and healthy women (HW). To identify explanatory variables of the discrepancies between the objective...
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Objective. To examine the agreement between objective (accelerometer) and subjective measures of sleep in fibromyalgia women (FW) and healthy women (HW). To identify explanatory variables of the discrepancies between the objective and subjective measures in FW and in HW.
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To characterize damage and deformation in an impacted area of structure caused by flying foreign objects, it is fundamentally needed to measure the acting force and its distribution over the area. In the present experiments, it wa...
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To characterize damage and deformation in an impacted area of structure caused by flying foreign objects, it is fundamentally needed to measure the acting force and its distribution over the area. In the present experiments, it was attempted toidentify visually the impact force using the pressure sensitive paper 'Prescale'. A split Hopkinson pressure bar method was used to evaluate the sensitivity of the paper under impact loading. It is found that the pressure sensitive paper instantaneouslyresponds even for the impact loading of which duration is several hundred microseconds, while the sensitivity is significantly reduced when compared to the quasi-static loading. Hertzian impact tests were tried to visually evaluate pressure distributionsusing the pressure sensitive paper, and the experimental results were discussed.
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In this study, the displacement during the oblique impact of a rigid rod with a deformable flat has been studied. An approach has been developed in order to relate the impact duration, the normal permanent deformation and the slid...
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In this study, the displacement during the oblique impact of a rigid rod with a deformable flat has been studied. An approach has been developed in order to relate the impact duration, the normal permanent deformation and the sliding length during the impact. The same impact has been analyzed using the numerical simulations, and the theoretical and numerical results have been compared. An experimental setup was built to measure the motion of the rod before and after the impact. The deformation region after the impact was scanned and measured. Using the experimental results and the calculated impact duration, an average normal contact force was calculated. The presented approach yields to more accurate results compared to the direct integration of equations of motion using selected quasi-static contact models.
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A concerning issue with Economic Impact Analysis (EIA) is that many EIAs give results for one year, without being explicit about how long impacts are expected to last. New tourism attractions should not be assumed to provide conti...
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A concerning issue with Economic Impact Analysis (EIA) is that many EIAs give results for one year, without being explicit about how long impacts are expected to last. New tourism attractions should not be assumed to provide continuing positive impacts into the future. For instance, the Giant Pandas at Adelaide Zoo generated a positive economic impact in their first year of residence (22% of a sample of tourists visited Adelaide due to pandas, additional tourism expenditure in the region was $27.7 million, with $2.3 to $4.6 million captured by the zoo); however, increased numbers visiting to see the pandas lasted only two years. Investment decision makers expected larger, longer-term economic benefits than eventuated, and the zoo experienced financial difficulties. This study provides advice for predictive EIA of new tourism attractions and prompts a call for tourism EIA studies to be explicit about the time period for which results are relevant.
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