Artificial neural network modeling and sensitivity analysis of performance and emissions in a compression ignition engine using biodiesel fuel
- Authors: Jaliliantabar, Farzad , Ghobadian, Barat , Najafi, Gholamhassan , Yusaf, Talal
- Date: 2018
- Type: Text , Journal article
- Relation: Energies Vol. 11, no. 9 (2018), p. 1-24
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- Description: In the present research work, a neural network model has been developed to predict the exhaust emissions and performance of a compression ignition engine. The significance and novelty of the work, with respect to existing literature, is the application of sensitivity analysis and an artificial neural network (ANN) simultaneously in order to predict the engine parameters. The inputs of the model were engine load (0, 25, 50, 75 and 100%), engine speed (1700, 2100, 2500 and 2900 rpm) and the percent of biodiesel fuel derived from waste cooking oil in diesel fuel (B0, B5, B10, B15 and B20). The relationship between the input parameters and engine cylinder performance and emissions can be determined by the network. The global sensitivity analysis results show that all the investigated factors are effective on the created model and cannot be ignored. In addition, it is found that the most emissions decreased while using biodiesel fuel in the compression ignition engine.
Body mass index is negatively associated with telomere length : A collaborative cross-sectional meta-analysis of 87 observational studies
- Authors: Gielen, Marij , Hageman, Geja , Antoniou, Evangelia , Nordfjall, Katarina , Mangino, Massimo , Balasubramanyam, Muthuswamy , De Meyer, Tim de , Hendricks, Audrey , Giltay, Erik , Hunt, Steven , Nettleton, Jennifer , Salpea, Klelia , Diaz, Vanessa , Farzaneh-Far, Ramin , Atzmon, Gil , Harris, Sarah , Hou, Lifang , Gilley, David , Hovatta, Iiris , Kark, Jeremy , Nassar, Hisham , Kurz, David , Mather, Karen , Willeit, Peter , Zheng, Yun-Ling , Pavanello, Sofia , Demerath, Ellen , Rode, Line , Bunout, Daniel , Steptoe, Andrew , Boardman, Lisa , Marti, Amelia , Needham, Belinda , Zheng, Wei , Ramsey-Goldman, Rosalind , Pellatt, Andrew , Kaprio, Jaakko , Hofmann, Jonathan , Gieger, Christian , Paolisso, Giuseppe , Hjelmborg, Jacob , Mirabello, Lisa , Seeman, Teresa , Wong, Jason , Van Der Harst, Pim , Broer, Linda , Kronenberg, Florian , Kollerits, Barbara , Strandberg, Timo , Eisenberg, Dan , Duggan, Catherine , Verhoeven, Josine , Schaakxs, Roxanne , Zannolli, Raffaela , Dos Reis, Rosana , Charchar, Fadi , Tomaszewski, Maciej , Mons, Ute , Demuth, Ilja , Molli, Andrea , Cheng, Guo , Krasnienkov, Dmytro , D'Antono, Bianca , Kasielski, Marek , McDonnell, Barry , Ebstein, Richard , Sundquist, Kristina , Pare, Guillaume , Chong, Michael , Zeegers, Maurice
- Date: 2018
- Type: Text , Journal article
- Relation: American Journal of Clinical Nutrition Vol. 108, no. 3 (2018), p. 453-475
- Relation: http://purl.org/au-research/grants/nhmrc/1123472
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- Description: Background: Even before the onset of age-related diseases, obesity might be a contributing factor to the cumulative burden of oxidative stress and chronic inflammation throughout the life course. Obesity may therefore contribute to accelerated shortening of telomeres. Consequently, obese persons are more likely to have shorter telomeres, but the association between body mass index (BMI) and leukocyte telomere length (TL) might differ across the life span and between ethnicities and sexes. Objective: A collaborative cross-sectionalmeta-analysis of observational studies was conducted to investigate the associations between BMI and TL across the life span. Design: Eighty-seven distinct study samples were included in the meta-analysis capturing data from 146,114 individuals. Studyspecific age- and sex-adjusted regression coefficients were combined by using a random-effects model in which absolute [base pairs (bp)] and relative telomere to single-copy gene ratio (T/S ratio) TLs were regressed against BMI. Stratified analysis was performed by 3 age categories ("young": 18-60 y; "middle": 61-75 y; and "old": >75 y), sex, and ethnicity. Results: Each unit increase in BMI corresponded to a-3.99 bp (95% CI: -5.17, -2.81 bp) difference in TL in the total pooled sample; among young adults, each unit increase in BMI corresponded to a -7.67 bp (95% CI:-10.03,-5.31 bp) difference. Each unit increase in BMI corresponded to a -1.58 × 10-3 unit T/S ratio (0.16% decrease; 95% CI: -2.14 × 10-3, -1.01 × 10-3) difference in ageand sex-adjusted relative TL in the total pooled sample; among young adults, each unit increase in BMI corresponded to a -2.58 × 10-3 unit T/S ratio (0.26% decrease; 95% CI: -3.92 × 10-3, -1.25 × 10-3). The associations were predominantly for the white pooled population. No sex differences were observed. Conclusions: A higher BMI is associated with shorter telomeres, especially in younger individuals. The presently observed difference is not negligible. Meta-analyses of longitudinal studies evaluating change in body weight alongside change in TL arewarranted.
Continuous patient monitoring with a patient centric agent : A block architecture
- Authors: Uddin, Ashraf , Stranieri, Andrew , Gondal, Iqbal , Balasubramanian, Venki
- Date: 2018
- Type: Text , Journal article
- Relation: IEEE Access Vol. 6, no. (2018), p. 32700-32726
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- Description: The Internet of Things (IoT) has facilitated services without human intervention for a wide range of applications, including continuous remote patient monitoring (RPM). However, the complexity of RPM architectures, the size of data sets generated and limited power capacity of devices make RPM challenging. In this paper, we propose a tier-based End to End architecture for continuous patient monitoring that has a patient centric agent (PCA) as its center piece. The PCA manages a blockchain component to preserve privacy when data streaming from body area sensors needs to be stored securely. The PCA based architecture includes a lightweight communication protocol to enforce security of data through different segments of a continuous, real time patient monitoring architecture. The architecture includes the insertion of data into a personal blockchain to facilitate data sharing amongst healthcare professionals and integration into electronic health records while ensuring privacy is maintained. The blockchain is customized for RPM with modifications that include having the PCA select a Miner to reduce computational effort, enabling the PCA to manage multiple blockchains for the same patient, and the modification of each block with a prefix tree to minimize energy consumption and incorporate secure transaction payments. Simulation results demonstrate that security and privacy can be enhanced in RPM with the PCA based End to End architecture.
Detection of power transformer winding deformation using improved FRA based on binary morphology and extreme point variation
- Authors: Zhao, Zhongyong , Yao, Chenguo , Li, Chengxiang , Islam, Syed
- Date: 2018
- Type: Text , Journal article
- Relation: IEEE Transactions on Industrial Electronics Vol. 65, no. 4 (2018), p. 3509-3519
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- Description: IEEE Frequency response analysis (FRA) has recently been developed as a widely accepted tool for power transformer winding mechanical deformation diagnosis, and has proven to be effective and powerful in many cases. However, there still exist problems regarding the application of FRA. FRA is a comparative method in which the measured FRA signature should be compared with its fingerprint. Small differences of FRA signatures in certain frequency bands might be produced by external disturbance, which hinders fault diagnosis. Additionally, the existing correlation coefficient indicator recommended by power industry standards cannot reflect key information of signatures, namely the extreme points. This paper proposes an improved FRA based on binary morphology and extreme point variation. Binary morphology is first introduced to extract the certain frequency bands of signatures with significant difference. A composite indicator of extreme point variation is adopted to realize the diagnosis of fault level. A ternary diagram is constructed by the area proportions of the binary image to identify winding faults, which has a potential to realize cluster analysis of fault types.
Development of flexible haptic forceps based on the electrohydraulic transmission system
- Authors: Ogawa, Kenji , Ibrahim, Yousef , Ohnishi, Kouhei
- Date: 2018
- Type: Text , Journal article
- Relation: IEEE Transactions on Industrial Informatics Vol. 14, no. 12 (2018), p. 5256-5267
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- Description: Minimally invasive surgery (MIS) has many benefits, e.g., unnecessary trauma and blood loss can be minimized by opening tiny surgery scars, recovery process of patients can be lessened, and the possibilities of complications can be decreased. The natural orifice transluminal surgery (NOTES) is one of the MIS surgical methodologies. NOTES surgery is performed using an endoscope. This methodology does not rely on making holes to patients' body to insert the medical instruments. Although some medical robots for NOTES have been proposed, current robots mainly suffer from the absence/limitation of haptic feedback to the surgeon's hands. In order to overcome this problem, this paper proposes electro hydraulic transmission system (EHTS) based forceps. The EHTS is a remote actuation system using fluid energy. By using the EHTS, the classical position and force transmission losses will not be influenced by the tube's shape. The validity of the proposal and its advantages have been experimentally verified and presented in this paper.
Development of flexible haptic forceps based on the electrohydraulic transmission system
- Authors: Ogawa, Kenji , Ibrahim, Yousef , Ohnishi, Kouhei
- Date: 2018
- Type: Text , Journal article
- Relation: IEEE Transactions on Industrial Informatics Vol. 14, no. 12 (2018), p. 5256-5267
- Full Text: false
- Reviewed:
- Description: Minimally invasive surgery (MIS) has many benefits, e.g., unnecessary trauma and blood loss can be minimized by opening tiny surgery scars, recovery process of patients can be lessened, and the possibilities of complications can be decreased. The natural orifice transluminal surgery (NOTES) is one of the MIS surgical methodologies. NOTES surgery is performed using an endoscope. This methodology does not rely on making holes to patients' body to insert the medical instruments. Although some medical robots for NOTES have been proposed, current robots mainly suffer from the absence/limitation of haptic feedback to the surgeon's hands. In order to overcome this problem, this paper proposes electro hydraulic transmission system (EHTS) based forceps. The EHTS is a remote actuation system using fluid energy. By using the EHTS, the classical position and force transmission losses will not be influenced by the tube's shape. The validity of the proposal and its advantages have been experimentally verified and presented in this paper.
Effectiveness of online tailored advice to prevent running-related injuries and promote preventive behaviour in Dutch trail runners : A pragmatic randomised controlled trial
- Authors: Hespanhol, Luiz , van Mechelen, Willem , Verhagen, Evert
- Date: 2018
- Type: Text , Journal article
- Relation: British journal of sports medicine Vol. 52, no. 13 (2018), p. 851-858
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- Description: BACKGROUND: Trail running is popular worldwide, but there is no preventive intervention for running-related injury (RRI). AIM: To evaluate the effectiveness of adding online tailored advice (TrailS6 ) to general advice on (1) the prevention of RRIs and (2) the determinants and actual preventive behaviour in Dutch trail runners. METHODS: Two-arm randomised controlled trial over 6 months. 232 trail runners were randomly assigned to an intervention or control group. All participants received online general advice on RRI prevention 1 week after baseline. Every 2 weeks, participants in the intervention group received specific advice tailored to their RRI status. The control group received no further intervention. Bayesian mixed models were used to analyse the data. RESULTS: Trail runners in the intervention group sustained 13% fewer RRIs compared with those in the control group after 6 months of follow-up (absolute risk difference -13.1%, 95% Bayesian highest posterior credible interval (95% BCI) -23.3 to -3.1). A preventive benefit was observed in one out of eight trail runners who had received the online tailored advice for 6 months (number needed to treat 8, 95% BCI 3 to 22). No significant between-group difference was observed on the determinants and actual preventive behaviours. CONCLUSIONS: Online tailored advice prevented RRIs among Dutch trail runners. Therefore, online tailored advice may be used as a preventive component in multicomponent RRI prevention programmes. No effect was observed on determinants and actual preventive behaviours. TRIAL REGISTRATION NUMBER: The Netherlands National Trial Register (NTR5431).
Efficient video coding using visual sensitive information for HEVC coding standard
- Authors: Podder, Pallab , Paul, Manoranjan , Murshed, Manzur
- Date: 2018
- Type: Text , Journal article
- Relation: IEEE Access Vol. 6, no. (2018), p. 75695-75708
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- Description: The latest high efficiency video coding (HEVC) standard introduces a large number of inter-mode block partitioning modes. The HEVC reference test model (HM) uses partially exhaustive tree-structured mode selection, which still explores a large number of prediction unit (PU) modes for a coding unit (CU). This impacts on encoding time rise which deprives a number of electronic devices having limited processing resources to use various features of HEVC. By analyzing the homogeneity, residual, and different statistical correlation among modes, many researchers speed-up the encoding process through the number of PU mode reduction. However, these approaches could not demonstrate the similar rate-distortion (RD) performance with the HM due to their dependency on existing Lagrangian cost function (LCF) within the HEVC framework. In this paper, to avoid the complete dependency on LCF in the initial phase, we exploit visual sensitive foreground motion and spatial salient metric (FMSSM) in a block. To capture its motion and saliency features, we use the dynamic background and visual saliency modeling, respectively. According to the FMSSM values, a subset of PU modes is then explored for encoding the CU. This preprocessing phase is independent from the existing LCF. As the proposed coding technique further reduces the number of PU modes using two simple criteria (i.e., motion and saliency), it outperforms the HM in terms of encoding time reduction. As it also encodes the uncovered and static background areas using the dynamic background frame as a substituted reference frame, it does not sacrifice quality. Tested results reveal that the proposed method achieves 32% average encoding time reduction of the HM without any quality loss for a wide range of videos.
Enabling global exchange of groundwater data : GroundWaterML2 (GWML2)
- Authors: Brodaric, Boyan , Boisvert, Eric , Chery, Laurence , Dahlhaus, Peter , Grellet, Sylvain , Kmoch, Alexander , Létourneau, Francois , Lucido, Jessica , Simons, Bruce , Wagner, Bernhard
- Date: 2018
- Type: Text , Journal article
- Relation: Hydrogeology Journal Vol. 26, no. 3 (2018), p. 733-741
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- Description: GWML2 is an international standard for the online exchange of groundwater data that addresses the problem of data heterogeneity. This problem makes groundwater data hard to find and use because the data are diversely structured and fragmented into numerous data silos. Overcoming data heterogeneity requires a common data format; however, until the development of GWML2, an appropriate international standard has been lacking. GWML2 represents key hydrogeological entities such as aquifers and water wells, as well as related measurements and groundwater flows. It is developed and tested by an international consortium of groundwater data providers from North America, Europe, and Australasia, and facilitates many forms of data exchange, information representation, and the development of online web portals and tools. © 2018, The Author(s).
Head impact velocities in FIS World Cup snowboarders and freestyle skiers : Do real-life impacts exceed helmet testing standards?
- Authors: Steenstrup, Sophie , Mok, Kam-Ming , McIntosh, Andrew , Bahr, Roald , Krosshaug, Tron
- Date: 2018
- Type: Text , Journal article
- Relation: British Journal of Sports Medicine Vol. 52, no. 1 (2018), p. 32-40
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- Description: Introduction Prior to the 2013-2014 season, the International Ski Federation (FIS) increased the helmet testing speed from a minimum requirement of 5.4 to 6.8 m/s for alpine downhill, super-G and giant slalom and for freestyle ski cross, but not for the other freestyle disciplines or snowboarding. Whether this increased testing speed reflects impact velocities in real head injury situations on snow is unclear. We therefore investigated the injury mechanisms and gross head impact biomechanics in four real head injury situations among World Cup (WC) snowboard and freestyle athletes and compared these with helmet homologation laboratory test requirements. The helmets in the four cases complied with at least European Standards (EN) 1077 (Class B) or American Society for Testing and Materials (ASTM) F2040. Methods We analysed four head injury videos from the FIS Injury Surveillance System throughout eight WC seasons (2006-2014) in detail. We used motion analysis software to digitize the helmet's trajectory and estimated the head's kinematics in two dimensions, including directly preimpact and postimpact. Results All four impacts were to the occiput. In the four cases, the normal-to-slope preimpact velocity ranged from 7.0(±SD 0.2) m/s to 10.5±0.5 m/s and the normalto-slope velocity change ranged from 8.4±0.6 m/s to 11.7±0.7 m/s. The sagittal plane helmet angular velocity estimates indicated a large change in angular velocity (25.0±2.9 rad/s to 49.1±0.3 rad/s). Conclusion The estimated normal-to-slope preimpact velocity was higher than the current strictest helmet testing rule of 6.8 m/s in all four cases. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved.
Head injury mechanisms in FIS World Cup alpine and freestyle skiers and snowboarders
- Authors: Steenstrup, Sophie , Bakken, Arnhild , Bere, Tone , Patton, Declan , Bahr, Roald
- Date: 2018
- Type: Text , Journal article
- Relation: British Journal of Sports Medicine Vol. 52, no. 1 (2018), p. 61-69
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- Description: Introduction Head injuries represent a concern in skiing and snowboarding, with traumatic brain injuries being the most common cause of death. Aim To describe the mechanisms of head and face injuries among World Cup alpine and freestyle skiers and snowboarders. Methods We performed a qualitative analysis of videos obtained of head and face injuries reported through the International Ski Federation Injury Surveillance System during 10 World Cup seasons (2006-2016). We analysed 57 head impact injury videos (alpine n=29, snowboard n=13, freestyle n=15), first independently and subsequently in a consensus meeting. Results During the crash sequence, most athletes (84%) impacted the snow with the skis or board first, followed by the upper or lower extremities, buttocks/pelvis, back and, finally, the head. Alpine skiers had sideways (45%) and backwards pitching falls (35%), with impacts to the rear (38%) and side (35%) of the helmet. Freestyle skiers and snowboarders had backwards pitching falls (snowboard 77%, freestyle 53%), mainly with impacts to the rear of the helmet (snowboard 69%, freestyle 40%). There were three helmet ejections among alpine skiers (10% of cases), and 41% of alpine skiing injuries occurred due to inappropriate gate contact prior to falling. Athletes had one (47%) or two (28%) head impacts, and the first impact was the most severe (71%). Head impacts were mainly on snow (83%) on a downward slope (63%). Conclusion This study has identified several characteristics of the mechanisms of head injuries, which may be addressed to reduce risk.
Improved method to obtain the online impulse frequency response signature of a power transformer by multi scale complex CWT
- Authors: Zhao, Zhongyong , Tang, Chao , Yao, Chenguo , Zhou, Qu , Xu, Lingna , Gui, Yingang , Islam, Syed
- Date: 2018
- Type: Text , Journal article
- Relation: IEEE Access Vol. 6, no. (2018), p. 48934-48945
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- Description: Online impulse frequency response analysis (IFRA) has proven to be a promising method to detect and diagnose the transformer winding mechanical faults when the transformer is in service. However, the existing fast Fourier transform (FFT) is actually not suitable for processing the transient signals in online IFRA. The field test result also shows that the IFRA signature obtained by FFT is easily distorted by noise. An improved method to obtain the online IFRA signature based on multi-scale complex continuous wavelet transform is proposed. The electrical model simulation and online experiment indicate the superiority of the wavelet transform compared with FFT. This paper provides guidance on the actual application of the online IFRA method.
Infographic : We have the programme, what next? Developing a plan of action to implement injury prevention exercise programmes in community sport
- Authors: Bekker, Sheree , Donaldson, Alex , Finch, Caroline
- Date: 2018
- Type: Text , Journal article
- Relation: British journal of sports medicine Vol. 52, no. 22 (2018), p. 1419-1420
- Full Text: false
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- Description: Exercise programmes to prevent injuries, such as lower-limb injuries that are common in community Australian Football
Modelling optimal warranty price for lifetime policies taking into account the uncertainties in life measures
- Authors: Rahman, Anisur , Chattopadhyay, Gopinath
- Date: 2018
- Type: Text , Journal article
- Relation: International Journal of Management Science and Engineering Management Vol. 13, no. 2 (2018), p. 84-90
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- Description: Owing to the assurance of longer reliable service life and greater customer peace of mind, products with a lifetime warranty are becoming more and more popular. Under such policies, both the manufacturer and the buyer are exposed to uncertainties and risks of warranty pricing and product performance since product lifetimes are uncertain and are not well defined in these policies. Considering the uncertainties in the measure of lifetime (useful life), this paper extends previous work of the authors [Rahman, A., & Chattopadhay, G. N. (2010). Modelling risks to manufacturer and buyer for lifetime warranty policies. International Journal of Management Science and Engineering Management, 5, 203–209] to determine the optimal warranty price. Risk preference models are developed to find the optimal warranty price through the use of the manufacturer’s utility function for profit and the buyer’s utility function for repair costs. The sensitivity of the risk preferences models are analysed using numerical examples with respect to factors such as the buyer’s and the manufacturer/dealer’s risk preferences, the buyer’s anticipated and the manufacturer’s estimated product failure intensity, the buyer’s loyalty to the original manufacturer/dealer in repairing failed products, and the buyer’s repair costs for non-warrantied products. Analysis of the developed models reveals that the manufacturer’s decisions on warranty price are strictly related to useful life, failure intensity of the product, and risk preferences. On the other hand, the buyer’s acceptance of a lifetime warranty depends on the expected lifetime of the product, the buyer’s anticipated product failure intensity, anticipated repair costs, and most importantly the buyer’s risk preference. © 2017 International Society of Management Science and Engineering Management.
Non-functional regression : A new challenge for neural networks
- Authors: Vamplew, Peter , Dazeley, Richard , Foale, Cameron , Choudhury, Tanveer
- Date: 2018
- Type: Text , Journal article
- Relation: Neurocomputing Vol. 314, no. (2018), p. 326-335
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- Description: This work identifies an important, previously unaddressed issue for regression based on neural networks – learning to accurately approximate problems where the output is not a function of the input (i.e. where the number of outputs required varies across input space). Such non-functional regression problems arise in a number of applications, and can not be adequately handled by existing neural network algorithms. To demonstrate the benefits possible from directly addressing non-functional regression, this paper proposes the first neural algorithm to do so – an extension of the Resource Allocating Network (RAN) which adds additional output neurons to the network structure during training. This new algorithm, called the Resource Allocating Network with Varying Output Cardinality (RANVOC), is demonstrated to be capable of learning to perform non-functional regression, on both artificially constructed data and also on the real-world task of specifying parameter settings for a plasma-spray process. Importantly RANVOC is shown to outperform not just the original RAN algorithm, but also the best possible error rates achievable by any functional form of regression.
Numerical estimation of stress intensity factors in cracked functionally graded piezoelectric materials - a scaled boundary finite element approach
- Authors: Pramod, A. , Ooi, Ean Tat , Song, Chongmin , Natarajan, Sundararajan
- Date: 2018
- Type: Text , Journal article
- Relation: Composite Structures Vol. 206, no. (2018), p. 301-312
- Full Text: false
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- Description: The stress intensity factors and the electrical displacement intensity factor for functionally graded piezoelectric materials (FGPMs) are influenced by: (a) the spatial variation of the mechanical property and (b) the electrical and mechanical boundary conditions. In this work, a semi-analytical technique is proposed to study the fracture parameters of FGPMs subjected to far field traction and electrical boundary conditions. A scaled boundary finite element formulation for the analysis of functionally graded piezoelectric materials is developed. The formulation is linearly complete for uncracked polygons and can capture crack tip singularity for cracked polygons. These salient features enable the computation of the fracture parameters directly from their definition. Numerical examples involving cracks in FGPMs show the accuracy and efficiency of the proposed technique.
On topology optimization and canonical duality method
- Authors: Gao, David
- Date: 2018
- Type: Text , Journal article
- Relation: Computer Methods in Applied Mechanics and Engineering Vol. 341, no. (2018), p. 249-277
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- Description: Topology optimization for general materials is correctly formulated as a bi-level knapsack problem, which is considered to be NP-hard in global optimization and computer science. By using canonical duality theory (CDT) developed by the author, the linear knapsack problem can be solved analytically to obtain global optimal solution at each design iteration. Both uniqueness, existence, and NP-hardness are discussed. The novel CDT method for general topology optimization is refined and tested by both 2-D and 3-D benchmark problems. Numerical results show that without using filter and any other artificial technique, the CDT method can produce exactly 0-1 optimal density distribution with almost no checkerboard pattern. Its performance and novelty are compared with the popular SIMP and BESO approaches. Additionally, some mathematical and conceptual mistakes in literature are explicitly addressed. A brief review on the canonical duality theory for modeling multi-scale complex systems and for solving general nonconvex/discrete problems are given in Appendix. This paper demonstrates a simple truth: elegant designs come from correct model and theory. © 2018
Paclitaxel-loaded self-assembled lipid nanoparticles as targeted drug delivery systems for the treatment of aggressive ovarian cancer
- Authors: Zhai, Jiali , Luwor, Rodney , Ahmed, Nuzhat , Escalona, Ruth , Tan, Fiona , Fong, Celesta , Ratcliffe, Julian , Scoble, Judith , Drummond, Calum , Tran, Nhiem
- Date: 2018
- Type: Text , Journal article
- Relation: ACS Applied Materials & Interfaces Vol. 10, no. 30 (2018), p. 25174-25185
- Full Text: false
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- Description: Chemotherapy using cytotoxic agents, such as paclitaxel (PTX), is one of the most effective treatments for advanced ovarian cancer. However, due to nonspecific targeting of the drug and the presence of toxic solvents required for dissolving PTX prior to injection, there are several serious side effects associated with this treatment. In this study, we explored self-assembled lipid-based nanoparticles as PTX carriers, which were able to improve its antitumour efficacy against ovarian cancer. The nanoparticles were also functionalized with epidermal growth factor receptor (EGFR) antibody fragments to explore the benefit of tumor active targeting. The formulated bicontinuous cubic- and sponge-phase nanoparticles, which were stabilized by Pluronic F127 and a lipid poly(ethylene glycol) stabilizer, showed a high capacity of PTX loading. These PTX-loaded nanoparticles also showed significantly higher cytotoxicity than a free drug formulation against HEY ovarian cancer cell lines in vitro. More importantly, the nanoparticle-based PTX treatments, with or without EGFR targeting, reduced the tumor burden by 50% compared to PTX or nondrug control in an ovarian cancer mouse xenograft model. In addition, the PTX-loaded nanoparticles were able to extend the survival of the treatment groups by up to 10 days compared to groups receiving free PTX or nondrug control. This proof-of-concept study has demonstrated the potential of these self-assembled lipid nanomaterials as effective drug delivery nanocarriers for poorly soluble chemotherapeutics, such as PTX.
Reconstruction of head impacts in FIS World Cup alpine skiing
- Authors: Steenstrup, Sophie , Mok, Kam-Ming , McIntosh, Andrew , Bahr, Roald , Krosshaug, Tron
- Date: 2018
- Type: Text , Journal article
- Relation: British Journal of Sports Medicine Vol. 52, no. 11 (2018), p. 709-715
- Full Text: false
- Reviewed:
- Description: Introduction Prior to the 2013/2014 season, the International Ski Federation (FIS) increased the helmet testing speed from 5.4 to 6.8 m/s for alpine downhill, super-G and giant slalom. Whether this increased testing speed reflects head impact velocities in real head injury situations on snow is unclear. We therefore investigated the injury mechanisms and gross head impact biomechanics in seven real head injury situations among World Cup (WC) alpine skiers. Methods We analysed nine head impacts from seven head injury videos from the FIS Injury Surveillance System, throughout nine WC seasons (2006-2015) in detail. We used commercial video-based motion analysis software to estimate head impact kinematics in two dimensions, including directly preimpact and postimpact, from broadcast video. The sagittal plane angular movement of the head was also measured using angle measurement software. Results In seven of nine head impacts, the estimated normal to slope preimpact velocity was higher than the current FIS helmet rule of 6.8 m/s (mean 8.1 (±SD 0.6) m/s, range 1.9±0.8 to 12.1±0.4 m/s). The nine head impacts had a mean normal to slope velocity change of 9.3±1.0 m/s, range 5.2±1.1 to 13.5±1.3 m/s. There was a large change in sagittal plane angular velocity (mean 43.3±2.9 rad/s (range 21.2±1.5 to 64.2±3.0 rad/s)) during impact. Conclusion The estimated normal to slope preimpact velocity was higher than the current FIS helmet rule of 6.8 m/s in seven of nine head impacts.
Reliability analysis of shear strength parameters of rock mass derived using the Hoek-Brown criterion
- Authors: Wen, Yiming , Wang, Chun , Zhao, Lei , You, Greg , Yang, Jianzhong , Zeng, Xiaoyan , Yang, Ze , Sun, Wei , Cheng, Yong , Lin, You
- Date: 2018
- Type: Text , Journal article
- Relation: Journal of Mines, Metals and Fuels Vol. 66, no. 8 (2018), p. 438-443
- Full Text: false
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- Description: Determining the mechanical parameters of a rock mass is a difficult but crucial matter in studies pertaining to stability. In this study, the Hoek-Brown criterion is used to derive the shear strength parameters of a rock mass; the parameters are subsequently optimized through reliability analyses, including the nonlinear Mohr-Coulomb envelope, optimized slopes, and least square variance methods. Further, through a case study of the Jianshan open pit mine, the c and ϕ values of the orebody were comparatively studied using the proposed method. The nonlinear Mohr-Coulomb envelope method and the optimized slopes method can attain reliability values exceeding 80%, as required by Chinese standards.