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Sample records for optimal marker placement

  1. Genetic evolutionary taboo search for optimal marker placement in infrared patient setup

    International Nuclear Information System (INIS)

    Riboldi, M; Baroni, G; Spadea, M F; Tagaste, B; Garibaldi, C; Cambria, R; Orecchia, R; Pedotti, A

    2007-01-01

    In infrared patient setup adequate selection of the external fiducial configuration is required for compensating inner target displacements (target registration error, TRE). Genetic algorithms (GA) and taboo search (TS) were applied in a newly designed approach to optimal marker placement: the genetic evolutionary taboo search (GETS) algorithm. In the GETS paradigm, multiple solutions are simultaneously tested in a stochastic evolutionary scheme, where taboo-based decision making and adaptive memory guide the optimization process. The GETS algorithm was tested on a group of ten prostate patients, to be compared to standard optimization and to randomly selected configurations. The changes in the optimal marker configuration, when TRE is minimized for OARs, were specifically examined. Optimal GETS configurations ensured a 26.5% mean decrease in the TRE value, versus 19.4% for conventional quasi-Newton optimization. Common features in GETS marker configurations were highlighted in the dataset of ten patients, even when multiple runs of the stochastic algorithm were performed. Including OARs in TRE minimization did not considerably affect the spatial distribution of GETS marker configurations. In conclusion, the GETS algorithm proved to be highly effective in solving the optimal marker placement problem. Further work is needed to embed site-specific deformation models in the optimization process

  2. Two-Phase Algorithm for Optimal Camera Placement

    Directory of Open Access Journals (Sweden)

    Jun-Woo Ahn

    2016-01-01

    Full Text Available As markers for visual sensor networks have become larger, interest in the optimal camera placement problem has continued to increase. The most featured solution for the optimal camera placement problem is based on binary integer programming (BIP. Due to the NP-hard characteristic of the optimal camera placement problem, however, it is difficult to find a solution for a complex, real-world problem using BIP. Many approximation algorithms have been developed to solve this problem. In this paper, a two-phase algorithm is proposed as an approximation algorithm based on BIP that can solve the optimal camera placement problem for a placement space larger than in current studies. This study solves the problem in three-dimensional space for a real-world structure.

  3. Optimal Geometrical Set for Automated Marker Placement to Virtualized Real-Time Facial Emotions.

    Directory of Open Access Journals (Sweden)

    Vasanthan Maruthapillai

    Full Text Available In recent years, real-time face recognition has been a major topic of interest in developing intelligent human-machine interaction systems. Over the past several decades, researchers have proposed different algorithms for facial expression recognition, but there has been little focus on detection in real-time scenarios. The present work proposes a new algorithmic method of automated marker placement used to classify six facial expressions: happiness, sadness, anger, fear, disgust, and surprise. Emotional facial expressions were captured using a webcam, while the proposed algorithm placed a set of eight virtual markers on each subject's face. Facial feature extraction methods, including marker distance (distance between each marker to the center of the face and change in marker distance (change in distance between the original and new marker positions, were used to extract three statistical features (mean, variance, and root mean square from the real-time video sequence. The initial position of each marker was subjected to the optical flow algorithm for marker tracking with each emotional facial expression. Finally, the extracted statistical features were mapped into corresponding emotional facial expressions using two simple non-linear classifiers, K-nearest neighbor and probabilistic neural network. The results indicate that the proposed automated marker placement algorithm effectively placed eight virtual markers on each subject's face and gave a maximum mean emotion classification rate of 96.94% using the probabilistic neural network.

  4. Optimal Geometrical Set for Automated Marker Placement to Virtualized Real-Time Facial Emotions.

    Science.gov (United States)

    Maruthapillai, Vasanthan; Murugappan, Murugappan

    2016-01-01

    In recent years, real-time face recognition has been a major topic of interest in developing intelligent human-machine interaction systems. Over the past several decades, researchers have proposed different algorithms for facial expression recognition, but there has been little focus on detection in real-time scenarios. The present work proposes a new algorithmic method of automated marker placement used to classify six facial expressions: happiness, sadness, anger, fear, disgust, and surprise. Emotional facial expressions were captured using a webcam, while the proposed algorithm placed a set of eight virtual markers on each subject's face. Facial feature extraction methods, including marker distance (distance between each marker to the center of the face) and change in marker distance (change in distance between the original and new marker positions), were used to extract three statistical features (mean, variance, and root mean square) from the real-time video sequence. The initial position of each marker was subjected to the optical flow algorithm for marker tracking with each emotional facial expression. Finally, the extracted statistical features were mapped into corresponding emotional facial expressions using two simple non-linear classifiers, K-nearest neighbor and probabilistic neural network. The results indicate that the proposed automated marker placement algorithm effectively placed eight virtual markers on each subject's face and gave a maximum mean emotion classification rate of 96.94% using the probabilistic neural network.

  5. Marker optimization for facial motion acquisition and deformation.

    Science.gov (United States)

    Le, Binh H; Zhu, Mingyang; Deng, Zhigang

    2013-11-01

    A long-standing problem in marker-based facial motion capture is what are the optimal facial mocap marker layouts. Despite its wide range of potential applications, this problem has not yet been systematically explored to date. This paper describes an approach to compute optimized marker layouts for facial motion acquisition as optimization of characteristic control points from a set of high-resolution, ground-truth facial mesh sequences. Specifically, the thin-shell linear deformation model is imposed onto the example pose reconstruction process via optional hard constraints such as symmetry and multiresolution constraints. Through our experiments and comparisons, we validate the effectiveness, robustness, and accuracy of our approach. Besides guiding minimal yet effective placement of facial mocap markers, we also describe and demonstrate its two selected applications: marker-based facial mesh skinning and multiresolution facial performance capture.

  6. Urethral catheterization facilitates preradiation fiducial marker placement in postprostatectomy patients.

    Science.gov (United States)

    Williams, Christopher; Costa, Joseph; Mandia, Stephen; Henderson, Randal; Marino, Robert; Mendenhall, Nancy

    2012-05-01

    Surgical absence of the prostate can make placement of fiducial markers difficult, because anatomic landmarks are distorted and there is a paucity of substantial tissue to hold fast the markers. We describe a method for improving the accuracy of fiducial marker placement for the purpose of salvage or adjuvant external beam radiation therapy for prostate cancer in patients who have undergone radical prostatectomy. To assist with identification of the urethrovesical junction and to facilitate placement of the markers, a Foley catheter was placed and the balloon was inflated. Gentle traction on the catheter seated the balloon at the bladder neck to echographically define the anatomy of the urethrovesical junction. Next, a rectal ultrasound probe was inserted into the rectum, allowing visualization of the region of the urethrovesical junction. Fiducial markers were then placed bilaterally in the detrusor muscle at the bladder neck or in the periurethral tissue using the applicator needle. The treating radiation oncologist verified that marker placement was suitable for assisting with radiation therapy in all cases. Preradiation pelvic imaging verified that markers were not in the bladder or urethral lumen, and there were no patient complaints of voiding out the markers with urination.

  7. Optimal PMU Placement By Improved Particle Swarm Optimization

    DEFF Research Database (Denmark)

    Rather, Zakir Hussain; Liu, Leo; Chen, Zhe

    2013-01-01

    This paper presents an improved method of binary particle swarm optimization (IBPSO) technique for optimal phasor measurement unit (PMU) placement in a power network for complete system observability. Various effective improvements have been proposed to enhance the efficiency and convergence rate...... of conventional particle swarm optimization method. The proposed method of IBPSO ensures optimal PMU placement with and without consideration of zero injection measurements. The proposed method has been applied to standard test systems like 17 bus, IEEE 24-bus, IEEE 30-bus, New England 39-bus, IEEE 57-bus system...

  8. SPOT-A SENSOR PLACEMENT OPTIMIZATION TOOL FOR ...

    Science.gov (United States)

    journal article This paper presents SPOT, a Sensor Placement Optimization Tool. SPOT provides a toolkit that facilitates research in sensor placement optimization and enables the practical application of sensor placement solvers to real-world CWS design applications. This paper provides an overview of SPOT’s key features, and then illustrates how this tool can be flexibly applied to solve a variety of different types of sensor placement problems.

  9. Optimal DG placement in deregulated electricity market

    International Nuclear Information System (INIS)

    Gautam, Durga; Mithulananthan, Nadarajah

    2007-01-01

    This paper presents two new methodologies for optimal placement of distributed generation (DG) in an optimal power flow (OPF) based wholesale electricity market. DG is assumed to participate in real time wholesale electricity market. The problem of optimal placement, including size, is formulated for two different objectives, namely, social welfare maximization and profit maximization. The candidate locations for DG placement are identified on the basis of locational marginal price (LMP). Obtained as lagrangian multiplier associated with active power flow equation for each node, LMP gives the short run marginal cost (SRMC) of electricity. Consumer payment, evaluated as a product of LMP and load at each load bus, is proposed as another ranking to identify candidate nodes for DG placement. The proposed rankings bridges engineering aspects of system operation and economic aspects of market operation and act as good indicators for the placement of DG, especially in a market environment. In order to provide a scenario of variety of DGs available in the market, several cost characteristics are assumed. For each DG cost characteristic, an optimal placement and size is identified for each of the objectives. The proposed methodology is tested in a modified IEEE 14 bus test system. (author)

  10. Optimal PMU Placement with Uncertainty Using Pareto Method

    Directory of Open Access Journals (Sweden)

    A. Ketabi

    2012-01-01

    Full Text Available This paper proposes a method for optimal placement of Phasor Measurement Units (PMUs in state estimation considering uncertainty. State estimation has first been turned into an optimization exercise in which the objective function is selected to be the number of unobservable buses which is determined based on Singular Value Decomposition (SVD. For the normal condition, Differential Evolution (DE algorithm is used to find the optimal placement of PMUs. By considering uncertainty, a multiobjective optimization exercise is hence formulated. To achieve this, DE algorithm based on Pareto optimum method has been proposed here. The suggested strategy is applied on the IEEE 30-bus test system in several case studies to evaluate the optimal PMUs placement.

  11. Lung tumor tracking during stereotactic radiotherapy treatment with the CyberKnife: Marker placement and early results

    International Nuclear Information System (INIS)

    Nuyttens, J.J.; Prevost, J.B.; Praag, J.; Hoogeman, M.; Levendag, P.C.; Klaveren, R.J. van; Pattynama, P.M.T.

    2006-01-01

    Lung tumor tracking during stereotactic radiotherapy with the CyberKnife requires the insertion of markers in or close to the tumor. To reduce the risk of pneumothorax, three methods of marker placement were used: 1) intravascular coil placement, 2) percutaneous intrathoracal, and 3) percutaneous extrathoracal placement. We investigated the toxicity of marker placement and the tumor response of the lung tumor tracking treatment. Markers were placed in 20 patients with 22 tumors: 13 patients received a curative treatment, seven a palliative. The median Charlson Comorbidity Score was 4 (range: 1-8). Platinum fiducials and intravascular embolisation coils were used as markers. In total, 78 markers were placed: 34 intrathoracal, 23 intravascular and 21 extrathoracal. The PTV equaled the GTV + 5 mm. A median dose of 45 Gy (range: 30-60 Gy, in 3 fractions) was prescribed to the 70-85% isodose. The response was evaluated with a CTscan performed 6-8 weeks after the last treatment and routinely thereafter. The median follow-up was 4 months (range: 2-11). No severe toxicity due to the marker placement was seen. Pneumothorax was not seen. The local control was 100%. Four tumors in four patients showed a complete response, 15 tumors in 14 patients a partial response, and three tumors in two patients with metastatic disease had stable disease. No severe toxicity of marker placement was seen due to the appropriate choice of one of the three methods. CyberKnife tumor tracking with markers is feasible and resulted in excellent tumor response. Longer follow-up is needed to validate the local control

  12. Transarterial Fiducial Marker Placement for Image-guided Proton Therapy for Malignant Liver Tumors

    Energy Technology Data Exchange (ETDEWEB)

    Ohta, Kengo, E-mail: yesterday.is.yesterday@gmail.com; Shimohira, Masashi, E-mail: mshimohira@gmail.com [Nagoya City University Graduate School of Medical Sciences, Department of Radiology (Japan); Sasaki, Shigeru, E-mail: ssasaki916@yahoo.co.jp; Iwata, Hiromitsu, E-mail: h-iwa-ncu@nifty.com; Nishikawa, Hiroko, E-mail: piroko1018@gmail.com; Ogino, Hiroyuki, E-mail: oginogio@gmail.com; Hara, Masaki, E-mail: mhara@med.nagoya-cu.ac.jp [Nagoya City West Medical Center, Department of Radiation Oncology, Nagoya Proton Therapy Center (Japan); Hashizume, Takuya, E-mail: tky300@gmail.com; Shibamoto, Yuta, E-mail: yshiba@med.nagoya-cu.ac.jp [Nagoya City University Graduate School of Medical Sciences, Department of Radiology (Japan)

    2015-10-15

    PurposeThe aim of this study is to analyze the technical and clinical success rates and safety of transarterial fiducial marker placement for image-guided proton therapy for malignant liver tumors.Methods and MaterialsFifty-five patients underwent this procedure as an interventional treatment. Five patients had 2 tumors, and 4 tumors required 2 markers each, so the total number of procedures was 64. The 60 tumors consisted of 46 hepatocellular carcinomas and 14 liver metastases. Five-mm-long straight microcoils of 0.018 inches in diameter were used as fiducial markers and placed in appropriate positions for each tumor. We assessed the technical and clinical success rates of transarterial fiducial marker placement, as well as the complications associated with it. Technical success was defined as the successful delivery and placement of the fiducial coil, and clinical success was defined as the completion of proton therapy.ResultsAll 64 fiducial coils were successfully installed, so the technical success rate was 100 % (64/64). Fifty-four patients underwent proton therapy without coil migration. In one patient, proton therapy was not performed because of obstructive jaundice due to bile duct invasion by hepatocellular carcinoma. Thus, the clinical success rate was 98 % (54/55). Slight bleeding was observed in one case, but it was stopped immediately and then observed. None of the patients developed hepatic infarctions due to fiducial marker migration.ConclusionTransarterial fiducial marker placement appears to be a useful and safe procedure for proton therapy for malignant liver tumors.

  13. Transarterial Fiducial Marker Placement for Image-guided Proton Therapy for Malignant Liver Tumors

    International Nuclear Information System (INIS)

    Ohta, Kengo; Shimohira, Masashi; Sasaki, Shigeru; Iwata, Hiromitsu; Nishikawa, Hiroko; Ogino, Hiroyuki; Hara, Masaki; Hashizume, Takuya; Shibamoto, Yuta

    2015-01-01

    PurposeThe aim of this study is to analyze the technical and clinical success rates and safety of transarterial fiducial marker placement for image-guided proton therapy for malignant liver tumors.Methods and MaterialsFifty-five patients underwent this procedure as an interventional treatment. Five patients had 2 tumors, and 4 tumors required 2 markers each, so the total number of procedures was 64. The 60 tumors consisted of 46 hepatocellular carcinomas and 14 liver metastases. Five-mm-long straight microcoils of 0.018 inches in diameter were used as fiducial markers and placed in appropriate positions for each tumor. We assessed the technical and clinical success rates of transarterial fiducial marker placement, as well as the complications associated with it. Technical success was defined as the successful delivery and placement of the fiducial coil, and clinical success was defined as the completion of proton therapy.ResultsAll 64 fiducial coils were successfully installed, so the technical success rate was 100 % (64/64). Fifty-four patients underwent proton therapy without coil migration. In one patient, proton therapy was not performed because of obstructive jaundice due to bile duct invasion by hepatocellular carcinoma. Thus, the clinical success rate was 98 % (54/55). Slight bleeding was observed in one case, but it was stopped immediately and then observed. None of the patients developed hepatic infarctions due to fiducial marker migration.ConclusionTransarterial fiducial marker placement appears to be a useful and safe procedure for proton therapy for malignant liver tumors

  14. An Aggregated Optimization Model for Multi-Head SMD Placements

    NARCIS (Netherlands)

    Ashayeri, J.; Ma, N.; Sotirov, R.

    2010-01-01

    In this article we propose an aggregate optimization approach by formulating the multi-head SMD placement optimization problem into a mixed integer program (MIP) with the variables based on batches of components. This MIP is tractable and effective in balancing workload among placement heads,

  15. An aggregated optimization model for multi-head SMD placements

    NARCIS (Netherlands)

    Ashayeri, J.; Ma, N.; Sotirov, R.

    2011-01-01

    In this article we propose an aggregate optimization approach by formulating the multi-head SMD placement optimization problem into a mixed integer program (MIP) with the variables based on batches of components. This MIP is tractable and effective in balancing workload among placement heads,

  16. Optimal placement of capacito

    Directory of Open Access Journals (Sweden)

    N. Gnanasekaran

    2016-06-01

    Full Text Available Optimal size and location of shunt capacitors in the distribution system plays a significant role in minimizing the energy loss and the cost of reactive power compensation. This paper presents a new efficient technique to find optimal size and location of shunt capacitors with the objective of minimizing cost due to energy loss and reactive power compensation of distribution system. A new Shark Smell Optimization (SSO algorithm is proposed to solve the optimal capacitor placement problem satisfying the operating constraints. The SSO algorithm is a recently developed metaheuristic optimization algorithm conceptualized using the shark’s hunting ability. It uses a momentum incorporated gradient search and a rotational movement based local search for optimization. To demonstrate the applicability of proposed method, it is tested on IEEE 34-bus and 118-bus radial distribution systems. The simulation results obtained are compared with previous methods reported in the literature and found to be encouraging.

  17. RJMCMC based Text Placement to Optimize Label Placement and Quantity

    Science.gov (United States)

    Touya, Guillaume; Chassin, Thibaud

    2018-05-01

    Label placement is a tedious task in map design, and its automation has long been a goal for researchers in cartography, but also in computational geometry. Methods that search for an optimal or nearly optimal solution that satisfies a set of constraints, such as label overlapping, have been proposed in the literature. Most of these methods mainly focus on finding the optimal position for a given set of labels, but rarely allow the removal of labels as part of the optimization. This paper proposes to apply an optimization technique called Reversible-Jump Markov Chain Monte Carlo that enables to easily model the removal or addition during the optimization iterations. The method, quite preliminary for now, is tested on a real dataset, and the first results are encouraging.

  18. Structural damage detection-oriented multi-type sensor placement with multi-objective optimization

    Science.gov (United States)

    Lin, Jian-Fu; Xu, You-Lin; Law, Siu-Seong

    2018-05-01

    A structural damage detection-oriented multi-type sensor placement method with multi-objective optimization is developed in this study. The multi-type response covariance sensitivity-based damage detection method is first introduced. Two objective functions for optimal sensor placement are then introduced in terms of the response covariance sensitivity and the response independence. The multi-objective optimization problem is formed by using the two objective functions, and the non-dominated sorting genetic algorithm (NSGA)-II is adopted to find the solution for the optimal multi-type sensor placement to achieve the best structural damage detection. The proposed method is finally applied to a nine-bay three-dimensional frame structure. Numerical results show that the optimal multi-type sensor placement determined by the proposed method can avoid redundant sensors and provide satisfactory results for structural damage detection. The restriction on the number of each type of sensors in the optimization can reduce the searching space in the optimization to make the proposed method more effective. Moreover, how to select a most optimal sensor placement from the Pareto solutions via the utility function and the knee point method is demonstrated in the case study.

  19. Optimal placement of distributed generation in distribution networks ...

    African Journals Online (AJOL)

    This paper proposes the application of Particle Swarm Optimization (PSO) technique to find the optimal size and optimum location for the placement of DG in the radial distribution networks for active power compensation by reduction in real power losses and enhancement in voltage profile. In the first segment, the optimal ...

  20. Bond graph to digraph conversion: A sensor placement optimization ...

    Indian Academy of Sciences (India)

    In this paper, we consider the optimal sensors placement problem for ... is due to the fact that the construction is generally done from the state equations, ... The Bond Graph (BG) tool defined in Paynter (1961) formal- ... Sensor placement and structural problem formulation .... Thus the obtained four matrices are as follows:.

  1. Binary cuckoo search based optimal PMU placement scheme for ...

    African Journals Online (AJOL)

    without including zero-injection effect, an Optimal PMU Placement strategy considering ..... in Indian power grid — A case study, Frontiers in Energy, Vol. ... optimization approach, Proceedings: International Conference on Intelligent Systems ...

  2. Endoscopy/EUS-guided fiducial marker placement in patients with esophageal cancer: a comparative analysis of 3 types of markers.

    Science.gov (United States)

    Machiels, Melanie; van Hooft, Jeanin; Jin, Peng; van Berge Henegouwen, Mark I; van Laarhoven, Hanneke M; Alderliesten, Tanja; Hulshof, Maarten C

    2015-10-01

    Markers placed at the borders of esophageal tumors are potentially useful to facilitate radiotherapy (RT) target delineation, which offers the possibility of image-guided RT. To evaluate and compare the feasibility and technical benefit of endoscopy/EUS-guided marker placement of 3 different types of markers in patients with esophageal cancer referred for RT. Prospective, single-center, feasibility and comparative study. Tertiary-care medical center. Thirty patients with esophageal cancer who were referred for RT. Patients underwent endoscopy/EUS-guided implantation of 1 type of marker. A solid gold marker (SM) with fixed dimensions, a flexible coil-shaped gold marker (FM) with hand-cut length (2-10 mm), and a radiopaque hydrogel marker (HG) were used. Technical feasibility and adverse events were registered. CT scans and cone-beam CT scans (CBCT) acquired during RT were analyzed to determine and compare the visibility and continuous clear visibility of the implanted markers. Technical feasibility, technical benefit, and adverse events of 3 types of markers. A total of 101 markers were placed in 30 patients. Implantation was technically feasible in all patients without grade 3 to 4 adverse events. Two patients with asymptomatic mediastinitis and one with asymptomatic pneumothorax were seen. Visibility on CT scan of all 3 types of implanted markers was adequate for target delineation. Eighty percent of FMs remained continuously visible over the treatment period on CBCT, significantly better than SMs (63%) and HGs (11%) (P = .015). When we selected FMs ≥5 mm, 90.5% remained visible on CBCT between implantation and the end of RT. Single-center, nonrandomized design. Endoscopy/EUS-guided fiducial marker placement for esophageal cancer is both safe and feasible and can be used for target volume delineation purposes on CT. Our results imply a significant advantage of FMs over SMs and HGs, regarding visibility and continuous clear visibility over the treatment period

  3. Percutaneous fiducial marker placement prior to stereotactic body radiotherapy for malignant liver tumors: an initial experience

    International Nuclear Information System (INIS)

    Ohta, Kengo; Shimohira, Masashi; Murai, Taro; Nishimura, Junichi; Iwata, Hiromitsu; Ogino, Hiroyuki; Hashizume, Takuya; Shibamoto, Yuta

    2016-01-01

    The aim of this study was to describe our initial experience with a gold flexible linear fiducial marker and to evaluate the safety and technical and clinical efficacy of stereotactic body radiotherapy using this marker for malignant liver tumors. Between July 2012 and February 2015, 18 patients underwent percutaneous fiducial marker placement before stereotactic body radiotherapy for malignant liver tumors. We evaluated the technical and clinical success rates of the procedure and the associated complications. Technical success was defined as successful placement of the fiducial marker at the target site, and clinical success was defined as the completion of stereotactic body radiotherapy without the marker dropping out of position. All 18 fiducial markers were placed successfully, so the technical success rate was 100% (18/18). All 18 patients were able to undergo stereotactic body radiotherapy without marker migration. Thus, the clinical success rate was 100% (18/18). Slight pneumothorax occurred as a minor complication in one case. No major complications such as coil migration or bleeding were observed. The examined percutaneous fiducial marker was safely placed in the liver and appeared to be useful for stereotactic body radiotherapy for malignant liver tumors

  4. Optimal Trajectories Generation in Robotic Fiber Placement Systems

    Science.gov (United States)

    Gao, Jiuchun; Pashkevich, Anatol; Caro, Stéphane

    2017-06-01

    The paper proposes a methodology for optimal trajectories generation in robotic fiber placement systems. A strategy to tune the parameters of the optimization algorithm at hand is also introduced. The presented technique transforms the original continuous problem into a discrete one where the time-optimal motions are generated by using dynamic programming. The developed strategy for the optimization algorithm tuning allows essentially reducing the computing time and obtaining trajectories satisfying industrial constraints. Feasibilities and advantages of the proposed methodology are confirmed by an application example.

  5. Optimization of portal placement for endoscopic calcaneoplasty

    NARCIS (Netherlands)

    van Sterkenburg, Maayke N.; Groot, Minke; Sierevelt, Inger N.; Spennacchio, Pietro A.; Kerkhoffs, Gino M. M. J.; van Dijk, C. Niek

    2011-01-01

    The purpose of our study was to determine an anatomic landmark to help locate portals in endoscopic calcaneoplasty. The device for optimal portal placement (DOPP) was developed to measure the distance from the distal fibula tip to the calcaneus (DFC) in 28 volunteers to determine the location of the

  6. Optimizing placement and equalization of multiple low frequency loudspeakers in rooms

    DEFF Research Database (Denmark)

    Celestinos, Adrian; Nielsen, Sofus Birkedal

    2005-01-01

    loudspeakers in rooms a simulation tool has been created based on finite-difference time-domain approximations (FDTD). Simulations have shown that by increasing the number of loudspeakers and modifying their placement a significant improvement is achieved. A more even sound pressure level distribution along...... a listening area is obtained. The placement of loudspeakers has been optimized. Furthermore an equalization strategy can be implemented for optimization purpose. This solution can be combined with multi channel sound systems....

  7. Improved Formulation for the Optimization of Wind Turbine Placement in a Wind Farm

    Directory of Open Access Journals (Sweden)

    Zong Woo Geem

    2013-01-01

    Full Text Available As an alternative to fossil fuels, wind can be considered because it is a renewable and greenhouse gas-free natural resource. When wind power is generated by wind turbines in a wind farm, the optimal placement of turbines is critical because different layouts produce different efficiencies. The objective of the wind turbine placement problem is to maximize the generated power while minimizing the cost in installing the turbines. This study proposes an efficient optimization formulation for the optimal layout of wind turbine placements under the resources (e.g., number of turbines or budget limit by introducing corresponding constraints. The proposed formulation gave users more conveniences in considering resources and budget bounds. After performing the optimization, results were compared using two different methods (branch and bound method and genetic algorithm and two different objective functions.

  8. Use of the Toric Surgical Marker to Aid in Intraoperative Plaque Placement for the USC Eye Physics Plaques to Treat Uveal Melanoma: A New Surgical Technique.

    Science.gov (United States)

    Berry, Jesse L; Kim, Jonathan W; Jennelle, Richard; Astrahan, Melvin

    2015-09-01

    To describe a new surgical technique for intraoperative placement of Eye Physics (EP) plaques for uveal melanoma using a toric marker. A toric marker is designed for cataract surgery to align the axis of astigmatism; its use was modified in this protocol to mark the axis of suture coordinates as calculated by Plaque Simulator (PS) software. The toric marker can be used to localize suture coordinates, in degrees, during intraoperative plaque placement. Linear marking using the toric marker decreases potential inaccuracies associated with the surgeon estimating 'clock-hours' by dot placement. Use of the toric marker aided surgical placement of EP plaques. The EP planning protocol is now designed to display the suture coordinates either by clock-hours or degrees, per surgeon preference. Future research is necessary to determine whether routine use of the toric marker improves operative efficiency. [Ophthalmic Surg Lasers Imaging Retina. 2015;46:866-870.]. Copyright 2015, SLACK Incorporated.

  9. Optimal Sensor Placement for Latticed Shell Structure Based on an Improved Particle Swarm Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Xun Zhang

    2014-01-01

    Full Text Available Optimal sensor placement is a key issue in the structural health monitoring of large-scale structures. However, some aspects in existing approaches require improvement, such as the empirical and unreliable selection of mode and sensor numbers and time-consuming computation. A novel improved particle swarm optimization (IPSO algorithm is proposed to address these problems. The approach firstly employs the cumulative effective modal mass participation ratio to select mode number. Three strategies are then adopted to improve the PSO algorithm. Finally, the IPSO algorithm is utilized to determine the optimal sensors number and configurations. A case study of a latticed shell model is implemented to verify the feasibility of the proposed algorithm and four different PSO algorithms. The effective independence method is also taken as a contrast experiment. The comparison results show that the optimal placement schemes obtained by the PSO algorithms are valid, and the proposed IPSO algorithm has better enhancement in convergence speed and precision.

  10. Optimal sensor placement for leak location in water distribution networks using genetic algorithms.

    Science.gov (United States)

    Casillas, Myrna V; Puig, Vicenç; Garza-Castañón, Luis E; Rosich, Albert

    2013-11-04

    This paper proposes a new sensor placement approach for leak location in water distribution networks (WDNs). The sensor placement problem is formulated as an integer optimization problem. The optimization criterion consists in minimizing the number of non-isolable leaks according to the isolability criteria introduced. Because of the large size and non-linear integer nature of the resulting optimization problem, genetic algorithms (GAs) are used as the solution approach. The obtained results are compared with a semi-exhaustive search method with higher computational effort, proving that GA allows one to find near-optimal solutions with less computational load. Moreover, three ways of increasing the robustness of the GA-based sensor placement method have been proposed using a time horizon analysis, a distance-based scoring and considering different leaks sizes. A great advantage of the proposed methodology is that it does not depend on the isolation method chosen by the user, as long as it is based on leak sensitivity analysis. Experiments in two networks allow us to evaluate the performance of the proposed approach.

  11. Optimal Sensor Placement for Leak Location in Water Distribution Networks Using Genetic Algorithms

    Directory of Open Access Journals (Sweden)

    Luis E. Garza-Castañón

    2013-11-01

    Full Text Available This paper proposes a new sensor placement approach for leak location in water distribution networks (WDNs. The sensor placement problem is formulated as an integer optimization problem. The optimization criterion consists in minimizing the number of non-isolable leaks according to the isolability criteria introduced. Because of the large size and non-linear integer nature of the resulting optimization problem, genetic algorithms (GAs are used as the solution approach. The obtained results are compared with a semi-exhaustive search method with higher computational effort, proving that GA allows one to find near-optimal solutions with less computational load. Moreover, three ways of increasing the robustness of the GA-based sensor placement method have been proposed using a time horizon analysis, a distance-based scoring and considering different leaks sizes. A great advantage of the proposed methodology is that it does not depend on the isolation method chosen by the user, as long as it is based on leak sensitivity analysis. Experiments in two networks allow us to evaluate the performance of the proposed approach.

  12. Optimal Sensor Placement for Leak Location in Water Distribution Networks Using Genetic Algorithms

    Science.gov (United States)

    Casillas, Myrna V.; Puig, Vicenç; Garza-Castañón, Luis E.; Rosich, Albert

    2013-01-01

    This paper proposes a new sensor placement approach for leak location in water distribution networks (WDNs). The sensor placement problem is formulated as an integer optimization problem. The optimization criterion consists in minimizing the number of non-isolable leaks according to the isolability criteria introduced. Because of the large size and non-linear integer nature of the resulting optimization problem, genetic algorithms (GAs) are used as the solution approach. The obtained results are compared with a semi-exhaustive search method with higher computational effort, proving that GA allows one to find near-optimal solutions with less computational load. Moreover, three ways of increasing the robustness of the GA-based sensor placement method have been proposed using a time horizon analysis, a distance-based scoring and considering different leaks sizes. A great advantage of the proposed methodology is that it does not depend on the isolation method chosen by the user, as long as it is based on leak sensitivity analysis. Experiments in two networks allow us to evaluate the performance of the proposed approach. PMID:24193099

  13. Optimal Placement of Phasor Measurement Units with New Considerations

    DEFF Research Database (Denmark)

    Su, Chi; Chen, Zhe

    2010-01-01

    Conventional phasor measurement unit (PMU) placement methods normally use the number of PMU installations as the objective function which is to be minimized. However, the cost of one installation of PMU is not always the same in different locations. It depends on a number of factors. One of these......Conventional phasor measurement unit (PMU) placement methods normally use the number of PMU installations as the objective function which is to be minimized. However, the cost of one installation of PMU is not always the same in different locations. It depends on a number of factors. One...... of these factors is taken into account in the proposed PMU placement method in this paper, which is the number of adjacent branches to the PMU located buses. The concept of full topological observability is adopted and a version of binary particle swarm optimization (PSO) algorithm is utilized. Results from...

  14. Influence of model errors in optimal sensor placement

    Science.gov (United States)

    Vincenzi, Loris; Simonini, Laura

    2017-02-01

    The paper investigates the role of model errors and parametric uncertainties in optimal or near optimal sensor placements for structural health monitoring (SHM) and modal testing. The near optimal set of measurement locations is obtained by the Information Entropy theory; the results of placement process considerably depend on the so-called covariance matrix of prediction error as well as on the definition of the correlation function. A constant and an exponential correlation function depending on the distance between sensors are firstly assumed; then a proposal depending on both distance and modal vectors is presented. With reference to a simple case-study, the effect of model uncertainties on results is described and the reliability and the robustness of the proposed correlation function in the case of model errors are tested with reference to 2D and 3D benchmark case studies. A measure of the quality of the obtained sensor configuration is considered through the use of independent assessment criteria. In conclusion, the results obtained by applying the proposed procedure on a real 5-spans steel footbridge are described. The proposed method also allows to better estimate higher modes when the number of sensors is greater than the number of modes of interest. In addition, the results show a smaller variation in the sensor position when uncertainties occur.

  15. Optimization of the Document Placement in the RFID Cabinet

    Directory of Open Access Journals (Sweden)

    Kiedrowicz Maciej

    2016-01-01

    Full Text Available The study is devoted to the issue of optimization of the document placement in a single RFID cabinet. It has been assumed that the optimization problem means the reduction of archivization time with respect to the information on all documents with RFID tags. Since the explicit form of the criterion function remains unknown, for the purpose of its approximation, the regression analysis method has been used. The method uses data from a computer simulation of the process of archiving data about documents. To solve the optimization problem, the modified gradient projection method has been used.

  16. Fast Optimal Replica Placement with Exhaustive Search Using Dynamically Reconfigurable Processor

    Directory of Open Access Journals (Sweden)

    Hidetoshi Takeshita

    2011-01-01

    Full Text Available This paper proposes a new replica placement algorithm that expands the exhaustive search limit with reasonable calculation time. It combines a new type of parallel data-flow processor with an architecture tuned for fast calculation. The replica placement problem is to find a replica-server set satisfying service constraints in a content delivery network (CDN. It is derived from the set cover problem which is known to be NP-hard. It is impractical to use exhaustive search to obtain optimal replica placement in large-scale networks, because calculation time increases with the number of combinations. To reduce calculation time, heuristic algorithms have been proposed, but it is known that no heuristic algorithm is assured of finding the optimal solution. The proposed algorithm suits parallel processing and pipeline execution and is implemented on DAPDNA-2, a dynamically reconfigurable processor. Experiments show that the proposed algorithm expands the exhaustive search limit by the factor of 18.8 compared to the conventional algorithm search limit running on a Neumann-type processor.

  17. MVMO-based approach for optimal placement and tuning of supplementary damping controller

    NARCIS (Netherlands)

    Rueda Torres, J.L.; Gonzalez-Longatt, F.

    2015-01-01

    This paper introduces an approach based on the Swarm Variant of the Mean-Variance Mapping Optimization (MVMO-S) to solve the multi-scenario formulation of the optimal placement and coordinated tuning of power system supplementary damping controllers (POCDCs). The effectiveness of the approach is

  18. Simulation based optimization on automated fibre placement process

    Science.gov (United States)

    Lei, Shi

    2018-02-01

    In this paper, a software simulation (Autodesk TruPlan & TruFiber) based method is proposed to optimize the automate fibre placement (AFP) process. Different types of manufacturability analysis are introduced to predict potential defects. Advanced fibre path generation algorithms are compared with respect to geometrically different parts. Major manufacturing data have been taken into consideration prior to the tool paths generation to achieve high success rate of manufacturing.

  19. Stability of Markers Used for Real-Time Tumor Tracking After Percutaneous Intrapulmonary Placement

    International Nuclear Information System (INIS)

    Voort van Zyp, Noelle C. van der; Hoogeman, Mischa S.; Water, Steven van de; Levendag, Peter C.; Holt, Bronno van der; Heijmen, Ben J.M.; Nuyttens, Joost J.

    2011-01-01

    Purpose: To determine the stability of markers used for real-time tumor tracking after percutaneous intrapulmonary placement. Methods and Materials: A total of 42 patients with 44 lesions, 111 markers, and ≥2 repeat computed tomography (CT) scans were studied. The tumor on the repeat CT scans was registered with the tumor on the planning CT scan. Next, the three-dimensional marker coordinates were determined on the planning CT scan and repeat CT scans. Marker stability was analyzed by the displacement of the markers and the displacement of the center of mass (COM) of the marker configurations. In addition, we assessed the reliability of using the intermarker distance as a check for displacements in the COM of the marker configurations. Results: The median marker displacement was 1.3 mm (range, 0.1-53.6). The marker displacement was >5 mm in 12% of the markers and >10 mm in 5% of the markers. The causes of marker displacement >5 mm included marker migration (2 of 13) and target volume changes (5 of 13). Nonsynchronous tumor and marker movement during breathing might have been responsible for the displacements >5 mm in the other 6 of 13 markers. The median displacement in the COM of the marker configurations was 1.0 mm (range, 0.1-23.3). Displacements in the COM of the marker configurations of ≥2.0 mm were detected by changes in the intermarker distance of >1.5 mm in 96% of the treatment fractions. Conclusion: The median marker displacement was small (1.3 mm). Nevertheless, displacements >5 mm occurred in 12% of the markers. Therefore, we recommend the implantation of multiple markers because multiple markers will enable a quick and reliable check of marker displacement by determining the change in the intermarker distance. A displacement in the COM of the marker configuration of ≥2.0 mm was almost always detected (96%) by a change in the distance between the markers of >1.5 mm. This enabled the displaced marker to be disabled, such that tumor localization was

  20. Sensor placement optimization for structural modal identification of flexible structures using genetic algorithm

    International Nuclear Information System (INIS)

    Jung, B. K.; Cho, J. R.; Jeong, W. B.

    2015-01-01

    The position of vibration sensors influences the modal identification quality of flexible structures for a given number of sensors, and the quality of modal identification is usually estimated in terms of correlation between the natural modes using the modal assurance criterion (MAC). The sensor placement optimization is characterized by the fact that the design variables are not continuous but discrete, implying that the conventional sensitivity-driven optimization methods are not applicable. In this context, this paper presents the application of genetic algorithm to the sensor placement optimization for improving the modal identification quality of flexible structures. A discrete-type optimization problem using genetic algorithm is formulated by defining the sensor positions and the MAC as the design variables and the objective function, respectively. The proposed GA-based evolutionary optimization method is validated through the numerical experiment with a rectangular plate, and its excellence is verified from the comparison with the cases using different modal correlation measures.

  1. Optimal placement and sizing of wind / solar based DG sources in distribution system

    Science.gov (United States)

    Guan, Wanlin; Guo, Niao; Yu, Chunlai; Chen, Xiaoguang; Yu, Haiyang; Liu, Zhipeng; Cui, Jiapeng

    2017-06-01

    Proper placement and sizing of Distributed Generation (DG) in distribution system can obtain maximum potential benefits. This paper proposes quantum particle swarm algorithm (QPSO) based wind turbine generation unit (WTGU) and photovoltaic (PV) array placement and sizing approach for real power loss reduction and voltage stability improvement of distribution system. Performance modeling of wind and solar generation system are described and classified into PQ\\PQ (V)\\PI type models in power flow. Considering the WTGU and PV based DGs in distribution system is geographical restrictive, the optimal area and DG capacity limits of each bus in the setting area need to be set before optimization, the area optimization method is proposed . The method has been tested on IEEE 33-bus radial distribution systems to demonstrate the performance and effectiveness of the proposed method.

  2. Efficient Sensor Placement Optimization Using Gradient Descent and Probabilistic Coverage

    Directory of Open Access Journals (Sweden)

    Vahab Akbarzadeh

    2014-08-01

    Full Text Available We are proposing an adaptation of the gradient descent method to optimize the position and orientation of sensors for the sensor placement problem. The novelty of the proposed method lies in the combination of gradient descent optimization with a realistic model, which considers both the topography of the environment and a set of sensors with directional probabilistic sensing. The performance of this approach is compared with two other black box optimization methods over area coverage and processing time. Results show that our proposed method produces competitive results on smaller maps and superior results on larger maps, while requiring much less computation than the other optimization methods to which it has been compared.

  3. Joint Optimization of Receiver Placement and Illuminator Selection for a Multiband Passive Radar Network.

    Science.gov (United States)

    Xie, Rui; Wan, Xianrong; Hong, Sheng; Yi, Jianxin

    2017-06-14

    The performance of a passive radar network can be greatly improved by an optimal radar network structure. Generally, radar network structure optimization consists of two aspects, namely the placement of receivers in suitable places and selection of appropriate illuminators. The present study investigates issues concerning the joint optimization of receiver placement and illuminator selection for a passive radar network. Firstly, the required radar cross section (RCS) for target detection is chosen as the performance metric, and the joint optimization model boils down to the partition p -center problem (PPCP). The PPCP is then solved by a proposed bisection algorithm. The key of the bisection algorithm lies in solving the partition set covering problem (PSCP), which can be solved by a hybrid algorithm developed by coupling the convex optimization with the greedy dropping algorithm. In the end, the performance of the proposed algorithm is validated via numerical simulations.

  4. Application of HGSO to security based optimal placement and parameter setting of UPFC

    International Nuclear Information System (INIS)

    Tarafdar Hagh, Mehrdad; Alipour, Manijeh; Teimourzadeh, Saeed

    2014-01-01

    Highlights: • A new method for solving the security based UPFC placement and parameter setting problem is proposed. • The proposed method is a global method for all mixed-integer problems. • The proposed method has the ability of the parallel search in binary and continues space. • By using the proposed method, most of the problems due to line contingencies are solved. • Comparison studies are done to compare the performance of the proposed method. - Abstract: This paper presents a novel method to solve security based optimal placement and parameter setting of unified power flow controller (UPFC) problem based on hybrid group search optimization (HGSO) technique. Firstly, HGSO is introduced in order to solve mix-integer type problems. Afterwards, the proposed method is applied to the security based optimal placement and parameter setting of UPFC problem. The focus of the paper is to enhance the power system security through eliminating or minimizing the over loaded lines and the bus voltage limit violations under single line contingencies. Simulation studies are carried out on the IEEE 6-bus, IEEE 14-bus and IEEE 30-bus systems in order to verify the accuracy and robustness of the proposed method. The results indicate that by using the proposed method, the power system remains secure under single line contingencies

  5. A New Optimization Framework To Solve The Optimal Feeder Reconfiguration And Capacitor Placement Problems

    Directory of Open Access Journals (Sweden)

    Mohammad-Reza Askari

    2015-07-01

    Full Text Available Abstract This paper introduces a new stochastic optimization framework based bat algorithm BA to solve the optimal distribution feeder reconfiguration DFR as well as the shunt capacitor placement and sizing in the distribution systems. The objective functions to be investigated are minimization of the active power losses and minimization of the total network costs an. In order to consider the uncertainties of the active and reactive loads in the problem point estimate method PEM with 2m scheme is employed as the stochastic tool. The feasibility and good performance of the proposed method are examined on the IEEE 69-bus test system.

  6. Optimized Virtual Machine Placement with Traffic-Aware Balancing in Data Center Networks

    Directory of Open Access Journals (Sweden)

    Tao Chen

    2016-01-01

    Full Text Available Virtualization has been an efficient method to fully utilize computing resources such as servers. The way of placing virtual machines (VMs among a large pool of servers greatly affects the performance of data center networks (DCNs. As network resources have become a main bottleneck of the performance of DCNs, we concentrate on VM placement with Traffic-Aware Balancing to evenly utilize the links in DCNs. In this paper, we first proposed a Virtual Machine Placement Problem with Traffic-Aware Balancing (VMPPTB and then proved it to be NP-hard and designed a Longest Processing Time Based Placement algorithm (LPTBP algorithm to solve it. To take advantage of the communication locality, we proposed Locality-Aware Virtual Machine Placement Problem with Traffic-Aware Balancing (LVMPPTB, which is a multiobjective optimization problem of simultaneously minimizing the maximum number of VM partitions of requests and minimizing the maximum bandwidth occupancy on uplinks of Top of Rack (ToR switches. We also proved it to be NP-hard and designed a heuristic algorithm (Least-Load First Based Placement algorithm, LLBP algorithm to solve it. Through extensive simulations, the proposed heuristic algorithm is proven to significantly balance the bandwidth occupancy on uplinks of ToR switches, while keeping the number of VM partitions of each request small enough.

  7. Brocade: Optimal flow placement in SDN networks

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    Today' network poses several challanges to network providers. These challanges fall in to a variety of areas ranging from determining efficient utilization of network bandwidth to finding out which user applications consume majority of network resources. Also, how to protect a given network from volumetric and botnet attacks. Optimal placement of flows deal with identifying network issues and addressing them in a real-time. The overall solution helps in building new services where a network is more secure and more efficient. Benefits derived as a result are increased network efficiency due to better capacity and resource planning, better security with real-time threat mitigation, and improved user experience as a result of increased service velocity.

  8. Optimizing virtual machine placement for energy and SLA in clouds using utility functions

    Directory of Open Access Journals (Sweden)

    Abdelkhalik Mosa

    2016-10-01

    Full Text Available Abstract Cloud computing provides on-demand access to a shared pool of computing resources, which enables organizations to outsource their IT infrastructure. Cloud providers are building data centers to handle the continuous increase in cloud users’ demands. Consequently, these cloud data centers consume, and have the potential to waste, substantial amounts of energy. This energy consumption increases the operational cost and the CO2 emissions. The goal of this paper is to develop an optimized energy and SLA-aware virtual machine (VM placement strategy that dynamically assigns VMs to Physical Machines (PMs in cloud data centers. This placement strategy co-optimizes energy consumption and service level agreement (SLA violations. The proposed solution adopts utility functions to formulate the VM placement problem. A genetic algorithm searches the possible VMs-to-PMs assignments with a view to finding an assignment that maximizes utility. Simulation results using CloudSim show that the proposed utility-based approach reduced the average energy consumption by approximately 6 % and the overall SLA violations by more than 38 %, using fewer VM migrations and PM shutdowns, compared to a well-known heuristics-based approach.

  9. A mixed integer linear programming approach for optimal DER portfolio, sizing, and placement in multi-energy microgrids

    International Nuclear Information System (INIS)

    Mashayekh, Salman; Stadler, Michael; Cardoso, Gonçalo; Heleno, Miguel

    2017-01-01

    Highlights: • This paper presents a MILP model for optimal design of multi-energy microgrids. • Our microgrid design includes optimal technology portfolio, placement, and operation. • Our model includes microgrid electrical power flow and heat transfer equations. • The case study shows advantages of our model over aggregate single-node approaches. • The case study shows the accuracy of the integrated linearized power flow model. - Abstract: Optimal microgrid design is a challenging problem, especially for multi-energy microgrids with electricity, heating, and cooling loads as well as sources, and multiple energy carriers. To address this problem, this paper presents an optimization model formulated as a mixed-integer linear program, which determines the optimal technology portfolio, the optimal technology placement, and the associated optimal dispatch, in a microgrid with multiple energy types. The developed model uses a multi-node modeling approach (as opposed to an aggregate single-node approach) that includes electrical power flow and heat flow equations, and hence, offers the ability to perform optimal siting considering physical and operational constraints of electrical and heating/cooling networks. The new model is founded on the existing optimization model DER-CAM, a state-of-the-art decision support tool for microgrid planning and design. The results of a case study that compares single-node vs. multi-node optimal design for an example microgrid show the importance of multi-node modeling. It has been shown that single-node approaches are not only incapable of optimal DER placement, but may also result in sub-optimal DER portfolio, as well as underestimation of investment costs.

  10. Poster – 41: External marker block placement on the breast or chest wall for left-sided deep inspiration breath-hold radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Conroy, Leigh; Guebert, Alexandra; Smith, Wendy [Tom Baker Cancer Centre (Canada)

    2016-08-15

    Purpose: We investigate DIBH breast radiotherapy using the Real-time Position Management (RPM) system with the marker-block placed on the target breast or chest wall. Methods: We measured surface dose for three different RPM marker-blocks using EBT3 Gafchromic film at 0° and 30° incidence. A registration study was performed to determine the breast surface position that best correlates with overall internal chest wall position. Surface and chest wall contours from MV images of the medial tangent field were extracted for 15 patients. Surface contours were divided into three potential marker-block positions on the breast: Superior, Middle, and Inferior. Translational registration was used to align the partial contours to the first-fraction contour. Each resultant transformation matrix was applied to the chest wall contour, and the minimum distance between the reference chest wall contour and the transformed chest wall contour was evaluated for each pixel. Results: The measured surface dose for the 2-dot, 6-dot, and 4-dot marker-blocks at 0° incidence were 74%, 71%, and 77% of dose to dmax respectively. At 30° beam incidence this increased to 76%, 72%, and 81%. The best external surface position was patient and fraction dependent, with no consistent best choice. Conclusions: The increase in surface dose directly under the RPM block is approximately equivalent to 3 mm of bolus. No marker-block position on the breast surface was found to be more representative of overall chest wall motion; therefore block positional stability and reproducibility can be used to determine optimal placement on the breast or chest wall.

  11. Optimal sensor placement for modal testing on wind turbines

    Science.gov (United States)

    Schulze, Andreas; Zierath, János; Rosenow, Sven-Erik; Bockhahn, Reik; Rachholz, Roman; Woernle, Christoph

    2016-09-01

    The mechanical design of wind turbines requires a profound understanding of the dynamic behaviour. Even though highly detailed simulation models are already in use to support wind turbine design, modal testing on a real prototype is irreplaceable to identify site-specific conditions such as the stiffness of the tower foundation. Correct identification of the mode shapes of a complex mechanical structure much depends on the placement of the sensors. For operational modal analysis of a 3 MW wind turbine with a 120 m rotor on a 100 m tower developed by W2E Wind to Energy, algorithms for optimal placement of acceleration sensors are applied. The mode shapes used for the optimisation are calculated by means of a detailed flexible multibody model of the wind turbine. Among the three algorithms in this study, the genetic algorithm with weighted off-diagonal criterion yields the sensor configuration with the highest quality. The ongoing measurements on the prototype will be the basis for the development of optimised wind turbine designs.

  12. Optimal Meter Placement for Distribution Network State Estimation: A Circuit Representation Based MILP Approach

    DEFF Research Database (Denmark)

    Chen, Xiaoshuang; Lin, Jin; Wan, Can

    2016-01-01

    State estimation (SE) in distribution networks is not as accurate as that in transmission networks. Traditionally, distribution networks (DNs) are lack of direct measurements due to the limitations of investments and the difficulties of maintenance. Therefore, it is critical to improve the accuracy...... of SE in distribution networks by placing additional physical meters. For state-of-the-art SE models, it is difficult to clearly quantify measurements' influences on SE errors, so the problems of optimal meter placement for reducing SE errors are mostly solved by heuristic or suboptimal algorithms....... Under this background, this paper proposes a circuit representation model to represent SE errors. Based on the matrix formulation of the circuit representation model, the problem of optimal meter placement can be transformed to a mixed integer linear programming problem (MILP) via the disjunctive model...

  13. Novel Technique for Hepatic Fiducial Marker Placement for Stereotactic Body Radiation Therapy

    International Nuclear Information System (INIS)

    Jarraya, Hajer; Chalayer, Chloé; Tresch, Emmanuelle; Bonodeau, Francois; Lacornerie, Thomas; Mirabel, Xavier; Boulanger, Thomas; Taieb, Sophie; Kramar, Andrew; Lartigau, Eric; Ceugnart, Luc

    2014-01-01

    Purpose: To report experience with fiducial marker insertion and describe an advantageous, novel technique for fiducial placement in the liver for stereotactic body radiation therapy with respiratory tracking. Methods and Materials: We implanted 1444 fiducials (single: 834; linked: 610) in 328 patients with 424 hepatic lesions. Two methods of implantation were compared: the standard method (631 single fiducials) performed on 153 patients from May 2007 to May 2010, and the cube method (813 fiducials: 610 linked/203 single) applied to 175 patients from April 2010 to March 2013. The standard method involved implanting a single marker at a time. The novel technique entailed implanting 2 pairs of linked markers when possible in a way to occupy the perpendicular edges of a cube containing the tumor inside. Results: Mean duration of the cube method was shorter than the standard method (46 vs 61 minutes; P<.0001). Median numbers of skin and subcapsular entries were significantly smaller with the cube method (2 vs 4, P<.0001, and 2 vs 4, P<.0001, respectively). The rate of overall complications (total, major, and minor) was significantly lower in the cube method group compared with the standard method group (5.7% vs 13.7%; P=.013). Major complications occurred while using single markers only. The success rate was 98.9% for the cube method and 99.3% for the standard method. Conclusions: We propose a new technique of hepatic fiducial implantation that makes use of linked fiducials and involves fewer skin entries and shorter time of implantation. The technique is less complication-prone and is migration-resistant

  14. Optimal Sensor placement for acoustic range-based underwater robotic positioning

    Digital Repository Service at National Institute of Oceanography (India)

    Glotzbach, T.; Moreno-Salinas, D.; Aranda, J.; Pascoal, A.M.

    by affording the reviewer an overview of relevant principles, methods, and results available in the literature in the area, as well as of the practical motivation for this challenging topic of research. After a brief literature survey, a method... position estimator. Naturally, the optimal placement solution is a function of the actual measurement setup, the measurement model, and the actual position of the target. At first inspection this problem may seem to have little practical relevance...

  15. Optimal Placement and Sizing of PV-STATCOM in Power Systems Using Empirical Data and Adaptive Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Reza Sirjani

    2018-03-01

    Full Text Available Solar energy is a source of free, clean energy which avoids the destructive effects on the environment that have long been caused by power generation. Solar energy technology rivals fossil fuels, and its development has increased recently. Photovoltaic (PV solar farms can only produce active power during the day, while at night, they are completely idle. At the same time, though, active power should be supported by reactive power. Reactive power compensation in power systems improves power quality and stability. The use during the night of a PV solar farm inverter as a static synchronous compensator (or PV-STATCOM device has recently been proposed which can improve system performance and increase the utility of a PV solar farm. In this paper, a method for optimal PV-STATCOM placement and sizing is proposed using empirical data. Considering the objectives of power loss and cost minimization as well as voltage improvement, two sub-problems of placement and sizing, respectively, are solved by a power loss index and adaptive particle swarm optimization (APSO. Test results show that APSO not only performs better in finding optimal solutions but also converges faster compared with bee colony optimization (BCO and lightening search algorithm (LSA. Installation of a PV solar farm, STATCOM, and PV-STATCOM in a system are each evaluated in terms of efficiency and cost.

  16. Optimal placement of excitations and sensors for verification of large dynamical systems

    Science.gov (United States)

    Salama, M.; Rose, T.; Garba, J.

    1987-01-01

    The computationally difficult problem of the optimal placement of excitations and sensors to maximize the observed measurements is studied within the framework of combinatorial optimization, and is solved numerically using a variation of the simulated annealing heuristic algorithm. Results of numerical experiments including a square plate and a 960 degrees-of-freedom Control of Flexible Structure (COFS) truss structure, are presented. Though the algorithm produces suboptimal solutions, its generality and simplicity allow the treatment of complex dynamical systems which would otherwise be difficult to handle.

  17. Optimal Sequential Diagnostic Strategy Generation Considering Test Placement Cost for Multimode Systems

    Directory of Open Access Journals (Sweden)

    Shigang Zhang

    2015-10-01

    Full Text Available Sequential fault diagnosis is an approach that realizes fault isolation by executing the optimal test step by step. The strategy used, i.e., the sequential diagnostic strategy, has great influence on diagnostic accuracy and cost. Optimal sequential diagnostic strategy generation is an important step in the process of diagnosis system construction, which has been studied extensively in the literature. However, previous algorithms either are designed for single mode systems or do not consider test placement cost. They are not suitable to solve the sequential diagnostic strategy generation problem considering test placement cost for multimode systems. Therefore, this problem is studied in this paper. A formulation is presented. Two algorithms are proposed, one of which is realized by system transformation and the other is newly designed. Extensive simulations are carried out to test the effectiveness of the algorithms. A real-world system is also presented. All the results show that both of them have the ability to solve the diagnostic strategy generation problem, and they have different characteristics.

  18. Optimal Sequential Diagnostic Strategy Generation Considering Test Placement Cost for Multimode Systems

    Science.gov (United States)

    Zhang, Shigang; Song, Lijun; Zhang, Wei; Hu, Zheng; Yang, Yongmin

    2015-01-01

    Sequential fault diagnosis is an approach that realizes fault isolation by executing the optimal test step by step. The strategy used, i.e., the sequential diagnostic strategy, has great influence on diagnostic accuracy and cost. Optimal sequential diagnostic strategy generation is an important step in the process of diagnosis system construction, which has been studied extensively in the literature. However, previous algorithms either are designed for single mode systems or do not consider test placement cost. They are not suitable to solve the sequential diagnostic strategy generation problem considering test placement cost for multimode systems. Therefore, this problem is studied in this paper. A formulation is presented. Two algorithms are proposed, one of which is realized by system transformation and the other is newly designed. Extensive simulations are carried out to test the effectiveness of the algorithms. A real-world system is also presented. All the results show that both of them have the ability to solve the diagnostic strategy generation problem, and they have different characteristics. PMID:26457709

  19. Looking for optimal number and placement of FACTS devices to manage the transmission congestion

    International Nuclear Information System (INIS)

    Rahimzadeh, Sajad; Tavakoli Bina, Mohammad

    2011-01-01

    Some applications of FACTS devices show that they are proper and effective tools to control the technical parameters of power systems. However determination of optimal number, location, size and type of these devices is a difficult problem. Moreover, applying a suitable objective function for optimal placement of FACTS devices plays a very important role in economic improvement of a power market. In this paper optimal placement of parallel and series FACTS devices is studied. The STATCOM is selected as a parallel FACTS device and SSSC as a series one. The optimization problem is formulated in regard to restructured environment and a new objective function is defined so that its minimization can alleviate the congestion and provide fairer conditions for power market participants. Moreover, an index based on objective function value is presented to determine the optimal number of each FACTS device in a specific designed algorithm. The power injection models for STATCOM and SSSC are adopted by applying neural models based on the averaging technique. This model takes the converter power losses into account and produces the required PQ-phasor that is suitable for power system steady state analysis. The proposed method is applied on modified IEEE 14-bus, 30-bus and 118-bus test systems and the results are analyzed.

  20. Optimal Capacitor Placement in Wind Farms by Considering Harmonics Using Discrete Lightning Search Algorithm

    Directory of Open Access Journals (Sweden)

    Reza Sirjani

    2017-09-01

    Full Text Available Currently, many wind farms exist throughout the world and, in some cases, supply a significant portion of energy to networks. However, numerous uncertainties remain with respect to the amount of energy generated by wind turbines and other sophisticated operational aspects, such as voltage and reactive power management, which requires further development and consideration. To fix the problem of poor reactive power compensation in wind farms, optimal capacitor placement has been proposed in existing wind farms as a simple and relatively inexpensive method. However, the use of induction generators, transformers, and additional capacitors represent potential problems for the harmonics of a system and therefore must be taken into account at wind farms. The optimal location and size of capacitors at buses of an 80-MW wind farm were determined according to modelled wind speed, system equivalent circuits, and harmonics in order to minimize energy losses, optimize reactive power and reduce the management costs. The discrete version of the lightning search algorithm (DLSA is a powerful and flexible nature-inspired optimization technique that was developed and implemented herein for optimal capacitor placement in wind farms. The obtained results are compared with the results of the genetic algorithm (GA and the discrete harmony search algorithm (DHSA.

  1. An Optimization Model for Product Placement on Product Listing Pages

    Directory of Open Access Journals (Sweden)

    Yan-Kwang Chen

    2014-01-01

    Full Text Available The design of product listing pages is a key component of Website design because it has significant influence on the sales volume on a Website. This study focuses on product placement in designing product listing pages. Product placement concerns how venders of online stores place their products over the product listing pages for maximization of profit. This problem is very similar to the offline shelf management problem. Since product information sources on a Web page are typically communicated through the text and image, visual stimuli such as color, shape, size, and spatial arrangement often have an effect on the visual attention of online shoppers and, in turn, influence their eventual purchase decisions. In view of the above, this study synthesizes the visual attention literature and theory of shelf-space allocation to develop a mathematical programming model with genetic algorithms for finding optimal solutions to the focused issue. The validity of the model is illustrated with example problems.

  2. Optimal placement of water-lubricated rubber bearings for vibration reduction of flexible multistage rotor systems

    Science.gov (United States)

    Liu, Shibing; Yang, Bingen

    2017-10-01

    Flexible multistage rotor systems with water-lubricated rubber bearings (WLRBs) have a variety of engineering applications. Filling a technical gap in the literature, this effort proposes a method of optimal bearing placement that minimizes the vibration amplitude of a WLRB-supported flexible rotor system with a minimum number of bearings. In the development, a new model of WLRBs and a distributed transfer function formulation are used to define a mixed continuous-and-discrete optimization problem. To deal with the case of uncertain number of WLRBs in rotor design, a virtual bearing method is devised. Solution of the optimization problem by a real-coded genetic algorithm yields the locations and lengths of water-lubricated rubber bearings, by which the prescribed operational requirements for the rotor system are satisfied. The proposed method is applicable either to preliminary design of a new rotor system with the number of bearings unforeknown or to redesign of an existing rotor system with a given number of bearings. Numerical examples show that the proposed optimal bearing placement is efficient, accurate and versatile in different design cases.

  3. Optimal placement and sizing of multiple distributed generating units in distribution

    Directory of Open Access Journals (Sweden)

    D. Rama Prabha

    2016-06-01

    Full Text Available Distributed generation (DG is becoming more important due to the increase in the demands for electrical energy. DG plays a vital role in reducing real power losses, operating cost and enhancing the voltage stability which is the objective function in this problem. This paper proposes a multi-objective technique for optimally determining the location and sizing of multiple distributed generation (DG units in the distribution network with different load models. The loss sensitivity factor (LSF determines the optimal placement of DGs. Invasive weed optimization (IWO is a population based meta-heuristic algorithm based on the behavior of weeds. This algorithm is used to find optimal sizing of the DGs. The proposed method has been tested for different load models on IEEE-33 bus and 69 bus radial distribution systems. This method has been compared with other nature inspired optimization methods. The simulated results illustrate the good applicability and performance of the proposed method.

  4. K.S. Micro-Implant Placement Guide

    OpenAIRE

    Sharma, K; Sangwan, A

    2014-01-01

    A one of the greatest concerns with orthodontic mini-implants is risk of injury to dental roots during placement is, especially when they are inserted between teeth. Many techniques have been used to facilitate safe placement of interradicular miniscrews. Brass Wires or metallic markers are easy to place in the interproximal spaces, but because their relative positions may be inconsistent in different radio -graphic views, they are not always accurate. K.S. micro implant placement guide sugge...

  5. Optimal Placement and Sizing of Fault Current Limiters in Distributed Generation Systems Using a Hybrid Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    N. Bayati

    2017-02-01

    Full Text Available Distributed Generation (DG connection in a power system tends to increase the short circuit level in the entire system which, in turn, could eliminate the protection coordination between the existing relays. Fault Current Limiters (FCLs are often used to reduce the short-circuit level of the network to a desirable level, provided that they are dully placed and appropriately sized. In this paper, a method is proposed for optimal placement of FCLs and optimal determination of their impedance values by which the relay operation time, the number and size of the FCL are minimized while maintaining the relay coordination before and after DG connection. The proposed method adopts the removal of low-impact FCLs and uses a hybrid Genetic Algorithm (GA optimization scheme to determine the optimal placement of FCLs and the values of their impedances. The suitability of the proposed method is demonstrated by examining the results of relay coordination in a typical DG network before and after DG connection.

  6. Multi-objective PSO based optimal placement of solar power DG in radial distribution system

    Directory of Open Access Journals (Sweden)

    Mahesh Kumar

    2017-06-01

    Full Text Available Ever increasing trend of electricity demand, fossil fuel depletion and environmental issues request the integration of renewable energy into the distribution system. The optimal planning of renewable distributed generation (DG is much essential for ensuring maximum benefits. Hence, this paper proposes the optimal placement of probabilistic based solar power DG into the distribution system. The two objective functions such as power loss reduction and voltage stability index improvement are optimized. The power balance and voltage limits are kept as constraints of the problem. The non-sorting pare to-front based multi-objective particle swarm optimization (MOPSO technique is proposed on standard IEEE 33 radial distribution test system.

  7. Simulation-Based Optimization of Camera Placement in the Context of Industrial Pose Estimation

    DEFF Research Database (Denmark)

    Jørgensen, Troels Bo; Iversen, Thorbjørn Mosekjær; Lindvig, Anders Prier

    2018-01-01

    In this paper, we optimize the placement of a camera in simulation in order to achieve a high success rate for a pose estimation problem. This is achieved by simulating 2D images from a stereo camera in a virtual scene. The stereo images are then used to generate 3D point clouds based on two diff...

  8. Optimized Placement of Wind Turbines in Large-Scale Offshore Wind Farm using Particle Swarm Optimization Algorithm

    DEFF Research Database (Denmark)

    Hou, Peng; Hu, Weihao; Soltani, Mohsen

    2015-01-01

    With the increasing size of wind farm, the impact of the wake effect on wind farm energy yields become more and more evident. The arrangement of the wind turbines’ (WT) locations will influence the capital investment and contribute to the wake losses which incur the reduction of energy production....... As a consequence, the optimized placement of the wind turbines may be done by considering the wake effect as well as the components cost within the wind farm. In this paper, a mathematical model which includes the variation of both wind direction and wake deficit is proposed. The problem is formulated by using...... Levelized Production Cost (LPC) as the objective function. The optimization procedure is performed by Particle Swarm Optimization (PSO) algorithm with the purpose of maximizing the energy yields while minimizing the total investment. The simulation results indicate that the proposed method is effective...

  9. Optimal Sparse Upstream Sensor Placement for Hydrokinetic Turbines

    Science.gov (United States)

    Cavagnaro, Robert; Strom, Benjamin; Ross, Hannah; Hill, Craig; Polagye, Brian

    2016-11-01

    Accurate measurement of the flow field incident upon a hydrokinetic turbine is critical for performance evaluation during testing and setting boundary conditions in simulation. Additionally, turbine controllers may leverage real-time flow measurements. Particle image velocimetry (PIV) is capable of rendering a flow field over a wide spatial domain in a controlled, laboratory environment. However, PIV's lack of suitability for natural marine environments, high cost, and intensive post-processing diminish its potential for control applications. Conversely, sensors such as acoustic Doppler velocimeters (ADVs), are designed for field deployment and real-time measurement, but over a small spatial domain. Sparsity-promoting regression analysis such as LASSO is utilized to improve the efficacy of point measurements for real-time applications by determining optimal spatial placement for a small number of ADVs using a training set of PIV velocity fields and turbine data. The study is conducted in a flume (0.8 m2 cross-sectional area, 1 m/s flow) with laboratory-scale axial and cross-flow turbines. Predicted turbine performance utilizing the optimal sparse sensor network and associated regression model is compared to actual performance with corresponding PIV measurements.

  10. A method of surface marker location optimization for tumor motion estimation in lung stereotactic body radiation therapy

    International Nuclear Information System (INIS)

    Lu, Bo; Park, Justin C.; Fan, Qiyong; Kahler, Darren; Liu, Chihray; Chen, Yunmei

    2015-01-01

    Purpose: Accurately localizing lung tumor localization is essential for high-precision radiation therapy techniques such as stereotactic body radiation therapy (SBRT). Since direct monitoring of tumor motion is not always achievable due to the limitation of imaging modalities for treatment guidance, placement of fiducial markers on the patient’s body surface to act as a surrogate for tumor position prediction is a practical alternative for tracking lung tumor motion during SBRT treatments. In this work, the authors propose an innovative and robust model to solve the multimarker position optimization problem. The model is able to overcome the major drawbacks of the sparse optimization approach (SOA) model. Methods: The principle-component-analysis (PCA) method was employed as the framework to build the authors’ statistical prediction model. The method can be divided into two stages. The first stage is to build the surrogate tumor matrix and calculate its eigenvalues and associated eigenvectors. The second stage is to determine the “best represented” columns of the eigenvector matrix obtained from stage one and subsequently acquire the optimal marker positions as well as numbers. Using 4-dimensional CT (4DCT) and breath hold CT imaging data, the PCA method was compared to the SOA method with respect to calculation time, average prediction accuracy, prediction stability, noise resistance, marker position consistency, and marker distribution. Results: The PCA and SOA methods which were both tested were on all 11 patients for a total of 130 cases including 4DCT and breath-hold CT scenarios. The maximum calculation time for the PCA method was less than 1 s with 64 752 surface points, whereas the average calculation time for the SOA method was over 12 min with 400 surface points. Overall, the tumor center position prediction errors were comparable between the two methods, and all were less than 1.5 mm. However, for the extreme scenarios (breath hold), the

  11. Development of Decision-Making Automated System for Optimal Placement of Physical Access Control System’s Elements

    Science.gov (United States)

    Danilova, Olga; Semenova, Zinaida

    2018-04-01

    The objective of this study is a detailed analysis of physical protection systems development for information resources. The optimization theory and decision-making mathematical apparatus is used to formulate correctly and create an algorithm of selection procedure for security systems optimal configuration considering the location of the secured object’s access point and zones. The result of this study is a software implementation scheme of decision-making system for optimal placement of the physical access control system’s elements.

  12. Strain sensors optimal placement for vibration-based structural health monitoring. The effect of damage on the initially optimal configuration

    Science.gov (United States)

    Loutas, T. H.; Bourikas, A.

    2017-12-01

    We revisit the optimal sensor placement of engineering structures problem with an emphasis on in-plane dynamic strain measurements and to the direction of modal identification as well as vibration-based damage detection for structural health monitoring purposes. The approach utilized is based on the maximization of a norm of the Fisher Information Matrix built with numerically obtained mode shapes of the structure and at the same time prohibit the sensorization of neighbor degrees of freedom as well as those carrying similar information, in order to obtain a satisfactory coverage. A new convergence criterion of the Fisher Information Matrix (FIM) norm is proposed in order to deal with the issue of choosing an appropriate sensor redundancy threshold, a concept recently introduced but not further investigated concerning its choice. The sensor configurations obtained via a forward sequential placement algorithm are sub-optimal in terms of FIM norm values but the selected sensors are not allowed to be placed in neighbor degrees of freedom providing thus a better coverage of the structure and a subsequent better identification of the experimental mode shapes. The issue of how service induced damage affects the initially nominated as optimal sensor configuration is also investigated and reported. The numerical model of a composite sandwich panel serves as a representative aerospace structure upon which our investigations are based.

  13. Optimal placement of active braces by using PSO algorithm in near- and far-field earthquakes

    Science.gov (United States)

    Mastali, M.; Kheyroddin, A.; Samali, B.; Vahdani, R.

    2016-03-01

    One of the most important issues in tall buildings is lateral resistance of the load-bearing systems against applied loads such as earthquake, wind and blast. Dual systems comprising core wall systems (single or multi-cell core) and moment-resisting frames are used as resistance systems in tall buildings. In addition to adequate stiffness provided by the dual system, most tall buildings may have to rely on various control systems to reduce the level of unwanted motions stemming from severe dynamic loads. One of the main challenges to effectively control the motion of a structure is limitation in distributing the required control along the structure height optimally. In this paper, concrete shear walls are used as secondary resistance system at three different heights as well as actuators installed in the braces. The optimal actuator positions are found by using optimized PSO algorithm as well as arbitrarily. The control performance of buildings that are equipped and controlled using the PSO algorithm method placement is assessed and compared with arbitrary placement of controllers using both near- and far-field ground motions of Kobe and Chi-Chi earthquakes.

  14. Optimal placement of multiple types of communicating sensors with availability and coverage redundancy constraints

    Science.gov (United States)

    Vecherin, Sergey N.; Wilson, D. Keith; Pettit, Chris L.

    2010-04-01

    Determination of an optimal configuration (numbers, types, and locations) of a sensor network is an important practical problem. In most applications, complex signal propagation effects and inhomogeneous coverage preferences lead to an optimal solution that is highly irregular and nonintuitive. The general optimization problem can be strictly formulated as a binary linear programming problem. Due to the combinatorial nature of this problem, however, its strict solution requires significant computational resources (NP-complete class of complexity) and is unobtainable for large spatial grids of candidate sensor locations. For this reason, a greedy algorithm for approximate solution was recently introduced [S. N. Vecherin, D. K. Wilson, and C. L. Pettit, "Optimal sensor placement with terrain-based constraints and signal propagation effects," Unattended Ground, Sea, and Air Sensor Technologies and Applications XI, SPIE Proc. Vol. 7333, paper 73330S (2009)]. Here further extensions to the developed algorithm are presented to include such practical needs and constraints as sensor availability, coverage by multiple sensors, and wireless communication of the sensor information. Both communication and detection are considered in a probabilistic framework. Communication signal and signature propagation effects are taken into account when calculating probabilities of communication and detection. Comparison of approximate and strict solutions on reduced-size problems suggests that the approximate algorithm yields quick and good solutions, which thus justifies using that algorithm for full-size problems. Examples of three-dimensional outdoor sensor placement are provided using a terrain-based software analysis tool.

  15. Optimal sensor placement for leakage detection and isolation in water distribution networks

    OpenAIRE

    Rosich Oliva, Albert; Sarrate Estruch, Ramon; Nejjari Akhi-Elarab, Fatiha

    2012-01-01

    In this paper, the problem of leakage detection and isolation in water distribution networks is addressed applying an optimal sensor placement methodology. The chosen technique is based on structural models and thus it is suitable to handle non-linear and large scale systems. A drawback of this technique arises when costs are assigned uniformly. A main contribution of this paper is the proposal of an iterative methodology that focuses on identifying essential sensors which ultimately leads to...

  16. Artificial Intelligence based technique for BTS placement

    Science.gov (United States)

    Alenoghena, C. O.; Emagbetere, J. O.; Aibinu, A. M.

    2013-12-01

    The increase of the base transceiver station (BTS) in most urban areas can be traced to the drive by network providers to meet demand for coverage and capacity. In traditional network planning, the final decision of BTS placement is taken by a team of radio planners, this decision is not fool proof against regulatory requirements. In this paper, an intelligent based algorithm for optimal BTS site placement has been proposed. The proposed technique takes into consideration neighbour and regulation considerations objectively while determining cell site. The application will lead to a quantitatively unbiased evaluated decision making process in BTS placement. An experimental data of a 2km by 3km territory was simulated for testing the new algorithm, results obtained show a 100% performance of the neighbour constrained algorithm in BTS placement optimization. Results on the application of GA with neighbourhood constraint indicate that the choices of location can be unbiased and optimization of facility placement for network design can be carried out.

  17. Artificial Intelligence based technique for BTS placement

    International Nuclear Information System (INIS)

    Alenoghena, C O; Emagbetere, J O; 1 Minna (Nigeria))" data-affiliation=" (Department of Telecommunications Engineering, Federal University of Techn.1 Minna (Nigeria))" >Aibinu, A M

    2013-01-01

    The increase of the base transceiver station (BTS) in most urban areas can be traced to the drive by network providers to meet demand for coverage and capacity. In traditional network planning, the final decision of BTS placement is taken by a team of radio planners, this decision is not fool proof against regulatory requirements. In this paper, an intelligent based algorithm for optimal BTS site placement has been proposed. The proposed technique takes into consideration neighbour and regulation considerations objectively while determining cell site. The application will lead to a quantitatively unbiased evaluated decision making process in BTS placement. An experimental data of a 2km by 3km territory was simulated for testing the new algorithm, results obtained show a 100% performance of the neighbour constrained algorithm in BTS placement optimization. Results on the application of GA with neighbourhood constraint indicate that the choices of location can be unbiased and optimization of facility placement for network design can be carried out

  18. Optimal Placement of A Heat Pump in An Integrated Power and Heat Energy System

    DEFF Research Database (Denmark)

    Klyapovskiy, Sergey; You, Shi; Bindner, Henrik W.

    2017-01-01

    With the present trend towards Smart Grids and Smart Energy Systems it is important to look for the opportunities for integrated development between different energy sectors, such as electricity, heating, gas and transportation. This paper investigates the problem of optimal placement of a heat...... pump – a component that links electric and heating utilities together. The system used to demonstrate the integrated planning approach has two neighboring 10kV feeders and several distribution substations with loads that require central heating from the heat pump. The optimal location is found...

  19. A triaxial accelerometer monkey algorithm for optimal sensor placement in structural health monitoring

    Science.gov (United States)

    Jia, Jingqing; Feng, Shuo; Liu, Wei

    2015-06-01

    Optimal sensor placement (OSP) technique is a vital part of the field of structural health monitoring (SHM). Triaxial accelerometers have been widely used in the SHM of large-scale structures in recent years. Triaxial accelerometers must be placed in such a way that all of the important dynamic information is obtained. At the same time, the sensor configuration must be optimal, so that the test resources are conserved. The recommended practice is to select proper degrees of freedom (DOF) based upon several criteria and the triaxial accelerometers are placed at the nodes corresponding to these DOFs. This results in non-optimal placement of many accelerometers. A ‘triaxial accelerometer monkey algorithm’ (TAMA) is presented in this paper to solve OSP problems of triaxial accelerometers. The EFI3 measurement theory is modified and involved in the objective function to make it more adaptable in the OSP technique of triaxial accelerometers. A method of calculating the threshold value based on probability theory is proposed to improve the healthy rate of monkeys in a troop generation process. Meanwhile, the processes of harmony ladder climb and scanning watch jump are proposed and given in detail. Finally, Xinghai NO.1 Bridge in Dalian is implemented to demonstrate the effectiveness of TAMA. The final results obtained by TAMA are compared with those of the original monkey algorithm and EFI3 measurement, which show that TAMA can improve computational efficiency and get a better sensor configuration.

  20. Method for Vibration Response Simulation and Sensor Placement Optimization of a Machine Tool Spindle System with a Bearing Defect

    Science.gov (United States)

    Cao, Hongrui; Niu, Linkai; He, Zhengjia

    2012-01-01

    Bearing defects are one of the most important mechanical sources for vibration and noise generation in machine tool spindles. In this study, an integrated finite element (FE) model is proposed to predict the vibration responses of a spindle bearing system with localized bearing defects and then the sensor placement for better detection of bearing faults is optimized. A nonlinear bearing model is developed based on Jones' bearing theory, while the drawbar, shaft and housing are modeled as Timoshenko's beam. The bearing model is then integrated into the FE model of drawbar/shaft/housing by assembling equations of motion. The Newmark time integration method is used to solve the vibration responses numerically. The FE model of the spindle-bearing system was verified by conducting dynamic tests. Then, the localized bearing defects were modeled and vibration responses generated by the outer ring defect were simulated as an illustration. The optimization scheme of the sensor placement was carried out on the test spindle. The results proved that, the optimal sensor placement depends on the vibration modes under different boundary conditions and the transfer path between the excitation and the response. PMID:23012514

  1. A risk-based multi-objective model for optimal placement of sensors in water distribution system

    Science.gov (United States)

    Naserizade, Sareh S.; Nikoo, Mohammad Reza; Montaseri, Hossein

    2018-02-01

    In this study, a new stochastic model based on Conditional Value at Risk (CVaR) and multi-objective optimization methods is developed for optimal placement of sensors in water distribution system (WDS). This model determines minimization of risk which is caused by simultaneous multi-point contamination injection in WDS using CVaR approach. The CVaR considers uncertainties of contamination injection in the form of probability distribution function and calculates low-probability extreme events. In this approach, extreme losses occur at tail of the losses distribution function. Four-objective optimization model based on NSGA-II algorithm is developed to minimize losses of contamination injection (through CVaR of affected population and detection time) and also minimize the two other main criteria of optimal placement of sensors including probability of undetected events and cost. Finally, to determine the best solution, Preference Ranking Organization METHod for Enrichment Evaluation (PROMETHEE), as a subgroup of Multi Criteria Decision Making (MCDM) approach, is utilized to rank the alternatives on the trade-off curve among objective functions. Also, sensitivity analysis is done to investigate the importance of each criterion on PROMETHEE results considering three relative weighting scenarios. The effectiveness of the proposed methodology is examined through applying it to Lamerd WDS in the southwestern part of Iran. The PROMETHEE suggests 6 sensors with suitable distribution that approximately cover all regions of WDS. Optimal values related to CVaR of affected population and detection time as well as probability of undetected events for the best optimal solution are equal to 17,055 persons, 31 mins and 0.045%, respectively. The obtained results of the proposed methodology in Lamerd WDS show applicability of CVaR-based multi-objective simulation-optimization model for incorporating the main uncertainties of contamination injection in order to evaluate extreme value

  2. Optimal Node Placement in Underwater Wireless Sensor Networks

    KAUST Repository

    Felamban, M.

    2013-03-25

    Wireless Sensor Networks (WSN) are expected to play a vital role in the exploration and monitoring of underwater areas which are not easily reachable by humans. However, underwater communication via acoustic waves is subject to several performance limitations that are very different from those used for terresstrial networks. In this paper, we investigate node placement for building an initial underwater WSN infrastructure. We formulate this problem as a nonlinear mathematical program with the objective of minimizing the total transmission loss under a given number of sensor nodes and targeted coverage volume. The obtained solution is the location of each node represented via a truncated octahedron to fill out the 3D space. Experiments are conducted to verify the proposed formulation, which is solved using Matlab optimization tool. Simulation is also conducted using an ns-3 simulator, and the simulation results are consistent with the obtained results from mathematical model with less than 10% error.

  3. Implementation of strength pareto evolutionary algorithm II in the multiobjective burnable poison placement optimization of KWU pressurized water reactor

    International Nuclear Information System (INIS)

    Gharari, Rahman; Poursalehi, Navid; Abbasi, Mohmmadreza; Aghale, Mahdi

    2016-01-01

    In this research, for the first time, a new optimization method, i.e., strength Pareto evolutionary algorithm II (SPEA-II), is developed for the burnable poison placement (BPP) optimization of a nuclear reactor core. In the BPP problem, an optimized placement map of fuel assemblies with burnable poison is searched for a given core loading pattern according to defined objectives. In this work, SPEA-II coupled with a nodal expansion code is used for solving the BPP problem of Kraftwerk Union AG (KWU) pressurized water reactor. Our optimization goal for the BPP is to achieve a greater multiplication factor (K-e-f-f) for gaining possible longer operation cycles along with more flattening of fuel assembly relative power distribution, considering a safety constraint on the radial power peaking factor. For appraising the proposed methodology, the basic approach, i.e., SPEA, is also developed in order to compare obtained results. In general, results reveal the acceptance performance and high strength of SPEA, particularly its new version, i.e., SPEA-II, in achieving a semioptimized loading pattern for the BPP optimization of KWU pressurized water reactor

  4. Implementation of strength pareto evolutionary algorithm II in the multiobjective burnable poison placement optimization of KWU pressurized water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Gharari, Rahman [Nuclear Science and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of); Poursalehi, Navid; Abbasi, Mohmmadreza; Aghale, Mahdi [Nuclear Engineering Dept, Shahid Beheshti University, Tehran (Iran, Islamic Republic of)

    2016-10-15

    In this research, for the first time, a new optimization method, i.e., strength Pareto evolutionary algorithm II (SPEA-II), is developed for the burnable poison placement (BPP) optimization of a nuclear reactor core. In the BPP problem, an optimized placement map of fuel assemblies with burnable poison is searched for a given core loading pattern according to defined objectives. In this work, SPEA-II coupled with a nodal expansion code is used for solving the BPP problem of Kraftwerk Union AG (KWU) pressurized water reactor. Our optimization goal for the BPP is to achieve a greater multiplication factor (K-e-f-f) for gaining possible longer operation cycles along with more flattening of fuel assembly relative power distribution, considering a safety constraint on the radial power peaking factor. For appraising the proposed methodology, the basic approach, i.e., SPEA, is also developed in order to compare obtained results. In general, results reveal the acceptance performance and high strength of SPEA, particularly its new version, i.e., SPEA-II, in achieving a semioptimized loading pattern for the BPP optimization of KWU pressurized water reactor.

  5. Optimizing Virtual Network Functions Placement in Virtual Data Center Infrastructure Using Machine Learning

    Science.gov (United States)

    Bolodurina, I. P.; Parfenov, D. I.

    2018-01-01

    We have elaborated a neural network model of virtual network flow identification based on the statistical properties of flows circulating in the network of the data center and characteristics that describe the content of packets transmitted through network objects. This enabled us to establish the optimal set of attributes to identify virtual network functions. We have established an algorithm for optimizing the placement of virtual data functions using the data obtained in our research. Our approach uses a hybrid method of visualization using virtual machines and containers, which enables to reduce the infrastructure load and the response time in the network of the virtual data center. The algorithmic solution is based on neural networks, which enables to scale it at any number of the network function copies.

  6. Finite element analysis and genetic algorithm optimization design for the actuator placement on a large adaptive structure

    Science.gov (United States)

    Sheng, Lizeng

    The dissertation focuses on one of the major research needs in the area of adaptive/intelligent/smart structures, the development and application of finite element analysis and genetic algorithms for optimal design of large-scale adaptive structures. We first review some basic concepts in finite element method and genetic algorithms, along with the research on smart structures. Then we propose a solution methodology for solving a critical problem in the design of a next generation of large-scale adaptive structures---optimal placements of a large number of actuators to control thermal deformations. After briefly reviewing the three most frequently used general approaches to derive a finite element formulation, the dissertation presents techniques associated with general shell finite element analysis using flat triangular laminated composite elements. The element used here has three nodes and eighteen degrees of freedom and is obtained by combining a triangular membrane element and a triangular plate bending element. The element includes the coupling effect between membrane deformation and bending deformation. The membrane element is derived from the linear strain triangular element using Cook's transformation. The discrete Kirchhoff triangular (DKT) element is used as the plate bending element. For completeness, a complete derivation of the DKT is presented. Geometrically nonlinear finite element formulation is derived for the analysis of adaptive structures under the combined thermal and electrical loads. Next, we solve the optimization problems of placing a large number of piezoelectric actuators to control thermal distortions in a large mirror in the presence of four different thermal loads. We then extend this to a multi-objective optimization problem of determining only one set of piezoelectric actuator locations that can be used to control the deformation in the same mirror under the action of any one of the four thermal loads. A series of genetic algorithms

  7. On the Design of Smart Parking Networks in the Smart Cities: An Optimal Sensor Placement Model

    Science.gov (United States)

    Bagula, Antoine; Castelli, Lorenzo; Zennaro, Marco

    2015-01-01

    Smart parking is a typical IoT application that can benefit from advances in sensor, actuator and RFID technologies to provide many services to its users and parking owners of a smart city. This paper considers a smart parking infrastructure where sensors are laid down on the parking spots to detect car presence and RFID readers are embedded into parking gates to identify cars and help in the billing of the smart parking. Both types of devices are endowed with wired and wireless communication capabilities for reporting to a gateway where the situation recognition is performed. The sensor devices are tasked to play one of the three roles: (1) slave sensor nodes located on the parking spot to detect car presence/absence; (2) master nodes located at one of the edges of a parking lot to detect presence and collect the sensor readings from the slave nodes; and (3) repeater sensor nodes, also called “anchor” nodes, located strategically at specific locations in the parking lot to increase the coverage and connectivity of the wireless sensor network. While slave and master nodes are placed based on geographic constraints, the optimal placement of the relay/anchor sensor nodes in smart parking is an important parameter upon which the cost and efficiency of the parking system depends. We formulate the optimal placement of sensors in smart parking as an integer linear programming multi-objective problem optimizing the sensor network engineering efficiency in terms of coverage and lifetime maximization, as well as its economic gain in terms of the number of sensors deployed for a specific coverage and lifetime. We propose an exact solution to the node placement problem using single-step and two-step solutions implemented in the Mosel language based on the Xpress-MPsuite of libraries. Experimental results reveal the relative efficiency of the single-step compared to the two-step model on different performance parameters. These results are consolidated by simulation results

  8. On the Design of Smart Parking Networks in the Smart Cities: An Optimal Sensor Placement Model

    Directory of Open Access Journals (Sweden)

    Antoine Bagula

    2015-06-01

    Full Text Available Smart parking is a typical IoT application that can benefit from advances in sensor, actuator and RFID technologies to provide many services to its users and parking owners of a smart city. This paper considers a smart parking infrastructure where sensors are laid down on the parking spots to detect car presence and RFID readers are embedded into parking gates to identify cars and help in the billing of the smart parking. Both types of devices are endowed with wired and wireless communication capabilities for reporting to a gateway where the situation recognition is performed. The sensor devices are tasked to play one of the three roles: (1 slave sensor nodes located on the parking spot to detect car presence/absence; (2 master nodes located at one of the edges of a parking lot to detect presence and collect the sensor readings from the slave nodes; and (3 repeater sensor nodes, also called “anchor” nodes, located strategically at specific locations in the parking lot to increase the coverage and connectivity of the wireless sensor network. While slave and master nodes are placed based on geographic constraints, the optimal placement of the relay/anchor sensor nodes in smart parking is an important parameter upon which the cost and efficiency of the parking system depends. We formulate the optimal placement of sensors in smart parking as an integer linear programming multi-objective problem optimizing the sensor network engineering efficiency in terms of coverage and lifetime maximization, as well as its economic gain in terms of the number of sensors deployed for a specific coverage and lifetime. We propose an exact solution to the node placement problem using single-step and two-step solutions implemented in the Mosel language based on the Xpress-MPsuite of libraries. Experimental results reveal the relative efficiency of the single-step compared to the two-step model on different performance parameters. These results are consolidated by

  9. On the Design of Smart Parking Networks in the Smart Cities: An Optimal Sensor Placement Model.

    Science.gov (United States)

    Bagula, Antoine; Castelli, Lorenzo; Zennaro, Marco

    2015-06-30

    Smart parking is a typical IoT application that can benefit from advances in sensor, actuator and RFID technologies to provide many services to its users and parking owners of a smart city. This paper considers a smart parking infrastructure where sensors are laid down on the parking spots to detect car presence and RFID readers are embedded into parking gates to identify cars and help in the billing of the smart parking. Both types of devices are endowed with wired and wireless communication capabilities for reporting to a gateway where the situation recognition is performed. The sensor devices are tasked to play one of the three roles: (1) slave sensor nodes located on the parking spot to detect car presence/absence; (2) master nodes located at one of the edges of a parking lot to detect presence and collect the sensor readings from the slave nodes; and (3) repeater sensor nodes, also called "anchor" nodes, located strategically at specific locations in the parking lot to increase the coverage and connectivity of the wireless sensor network. While slave and master nodes are placed based on geographic constraints, the optimal placement of the relay/anchor sensor nodes in smart parking is an important parameter upon which the cost and efficiency of the parking system depends. We formulate the optimal placement of sensors in smart parking as an integer linear programming multi-objective problem optimizing the sensor network engineering efficiency in terms of coverage and lifetime maximization, as well as its economic gain in terms of the number of sensors deployed for a specific coverage and lifetime. We propose an exact solution to the node placement problem using single-step and two-step solutions implemented in the Mosel language based on the Xpress-MPsuite of libraries. Experimental results reveal the relative efficiency of the single-step compared to the two-step model on different performance parameters. These results are consolidated by simulation results

  10. Optimizing VM allocation and data placement for data-intensive applications in cloud using ACO metaheuristic algorithm

    Directory of Open Access Journals (Sweden)

    T.P. Shabeera

    2017-04-01

    Full Text Available Nowadays data-intensive applications for processing big data are being hosted in the cloud. Since the cloud environment provides virtualized resources for computation, and data-intensive applications require communication between the computing nodes, the placement of Virtual Machines (VMs and location of data affect the overall computation time. Majority of the research work reported in the current literature consider the selection of physical nodes for placing data and VMs as independent problems. This paper proposes an approach which considers VM placement and data placement hand in hand. The primary objective is to reduce cross network traffic and bandwidth usage, by placing required number of VMs and data in Physical Machines (PMs which are physically closer. The VM and data placement problem (referred as MinDistVMDataPlacement problem is defined in this paper and has been proved to be NP- Hard. This paper presents and evaluates a metaheuristic algorithm based on Ant Colony Optimization (ACO, which selects a set of adjacent PMs for placing data and VMs. Data is distributed in the physical storage devices of the selected PMs. According to the processing capacity of each PM, a set of VMs are placed on these PMs to process data stored in them. We use simulation to evaluate our algorithm. The results show that the proposed algorithm selects PMs in close proximity and the jobs executed in the VMs allocated by the proposed scheme outperforms other allocation schemes.

  11. Epicardial left ventricular lead placement for cardiac resynchronization therapy: optimal pace site selection with pressure-volume loops.

    Science.gov (United States)

    Dekker, A L A J; Phelps, B; Dijkman, B; van der Nagel, T; van der Veen, F H; Geskes, G G; Maessen, J G

    2004-06-01

    Patients in heart failure with left bundle branch block benefit from cardiac resynchronization therapy. Usually the left ventricular pacing lead is placed by coronary sinus catheterization; however, this procedure is not always successful, and patients may be referred for surgical epicardial lead placement. The objective of this study was to develop a method to guide epicardial lead placement in cardiac resynchronization therapy. Eleven patients in heart failure who were eligible for cardiac resynchronization therapy were referred for surgery because of failed coronary sinus left ventricular lead implantation. Minithoracotomy or thoracoscopy was performed, and a temporary epicardial electrode was used for biventricular pacing at various sites on the left ventricle. Pressure-volume loops with the conductance catheter were used to select the best site for each individual patient. Relative to the baseline situation, biventricular pacing with an optimal left ventricular lead position significantly increased stroke volume (+39%, P =.01), maximal left ventricular pressure derivative (+20%, P =.02), ejection fraction (+30%, P =.007), and stroke work (+66%, P =.006) and reduced end-systolic volume (-6%, P =.04). In contrast, biventricular pacing at a suboptimal site did not significantly change left ventricular function and even worsened it in some cases. To optimize cardiac resynchronization therapy with epicardial leads, mapping to determine the best pace site is a prerequisite. Pressure-volume loops offer real-time guidance for targeting epicardial lead placement during minimal invasive surgery.

  12. Incorporation of conventional genetic markers and RAPD markers into an RFLP based map in maize

    International Nuclear Information System (INIS)

    Coe, E.H. Jr.; McMullen, M.D.; Polacco, M.; Davis, G.L.; Chao, S.

    1998-01-01

    Integration of classical genetic markers, in particular mutants, onto the maize Restriction Fragment Length Polymorphism (RFLP) map will provide the tools necessary to further our understanding of plant development and of complex traits. Initially integration was accomplished by visual alignment of common markers and sometimes involved the use of information from several different molecular maps to determine the relative placement of a single mutant. The maize core marker set was designed to provide a common set of markers which could be used for integration of map data. We have completed the mapping, of 56 mutants on chromosome one relative to the core marker set. Phenotypes included whole plant, seedling, and kernel effects and represented a variety of biological processes. Since these mutants were previously located to chromosome arm, mapping required the use of only seven markers per mutant to define the correct bin location. Two mistakes in marker order relative to the classical map were identified, as well as, six groups of mutants which require allelism testing. Placement of mutants and cDNAs into bins using, the core markers provides a necessary resource for identification of gene function in maize. (author)

  13. [Method for optimal sensor placement in water distribution systems with nodal demand uncertainties].

    Science.gov (United States)

    Liu, Shu-Ming; Wu, Xue; Ouyang, Le-Yan

    2013-08-01

    The notion of identification fitness was proposed for optimizing sensor placement in water distribution systems. Nondominated Sorting Genetic Algorithm II was used to find the Pareto front between minimum overlap of possible detection times of two events and the best probability of detection, taking nodal demand uncertainties into account. This methodology was applied to an example network. The solutions show that the probability of detection and the number of possible locations are not remarkably affected by nodal demand uncertainties, but the sources identification accuracy declines with nodal demand uncertainties.

  14. K.s. Micro-implant placement guide.

    Science.gov (United States)

    Sharma, K; Sangwan, A

    2014-09-01

    A one of the greatest concerns with orthodontic mini-implants is risk of injury to dental roots during placement is, especially when they are inserted between teeth. Many techniques have been used to facilitate safe placement of interradicular miniscrews. Brass Wires or metallic markers are easy to place in the interproximal spaces, but because their relative positions may be inconsistent in different radio -graphic views, they are not always accurate. K.S. micro implant placement guide suggested in this article is simple design and easy in fabrication, required minimal equipment for fabrication and does not disturb the existing appliance system, clearly located in the radiograph and the mini-screw can be easily inserted through the guide reducing the chance of implant misplacement.

  15. Solve: a non linear least-squares code and its application to the optimal placement of torsatron vertical field coils

    International Nuclear Information System (INIS)

    Aspinall, J.

    1982-01-01

    A computational method was developed which alleviates the need for lengthy parametric scans as part of a design process. The method makes use of a least squares algorithm to find the optimal value of a parameter vector. Optimal is defined in terms of a utility function prescribed by the user. The placement of the vertical field coils of a torsatron is such a non linear problem

  16. Optimal power flow with optimal placement TCSC device on 500 kV Java-Bali electrical power system using genetic Algorithm-Taguchi method

    Science.gov (United States)

    Apribowo, Chico Hermanu Brillianto; Ibrahim, Muhammad Hamka; Wicaksono, F. X. Rian

    2018-02-01

    The growing burden of the load and the complexity of the power system has had an impact on the need for optimization of power system operation. Optimal power flow (OPF) with optimal location placement and rating of thyristor controlled series capacitor (TCSC) is an effective solution used to determine the economic cost of operating the plant and regulate the power flow in the power system. The purpose of this study is to minimize the total cost of generation by placing the location and the optimal rating of TCSC using genetic algorithm-design of experiment techniques (GA-DOE). Simulation on Java-Bali system 500 kV with the amount of TCSC used by 5 compensator, the proposed method can reduce the generation cost by 0.89% compared to OPF without using TCSC.

  17. Minimal invasive epicardial lead implantation: optimizing cardiac resynchronization with a new mapping device for epicardial lead placement.

    Science.gov (United States)

    Maessen, J G; Phelps, B; Dekker, A L A J; Dijkman, B

    2004-05-01

    To optimize resynchronization in biventricular pacing with epicardial leads, mapping to determine the best pacing site, is a prerequisite. A port access surgical mapping technique was developed that allowed multiple pace site selection and reproducible lead evaluation and implantation. Pressure-volume loops analysis was used for real time guidance in targeting epicardial lead placement. Even the smallest changes in lead position revealed significantly different functional results. Optimizing the pacing site with this technique allowed functional improvement up to 40% versus random pace site selection.

  18. Optimization of Placement Driven by the Cost of Wire Crossing

    National Research Council Canada - National Science Library

    Kapur, Nevin

    1997-01-01

    .... We implemented a prototype placement algorithm TOCO that minimizes the cost of wire crossing, and a universal unit-grid based placement evaluator place_eval. We have designed a number of statistical experiments to demonstrate the feasibility and the promise of the proposed approach.

  19. Pragmatic Approach for Multistage Phasor Measurement Unit Placement

    DEFF Research Database (Denmark)

    Rather, Zakir Hussain; Chen, Zhe; Thoegersen, Poul

    2016-01-01

    Effective phasor measurement unit (PMU) placement is a key to the implementation of efficient and economically feasible wide area measurement systems in modern power systems. This paper proposes a pragmatic approach for cost-effective stage-wise deployment of PMUs while considering realistic...... constraints. Inspired from a real world experience, the proposed approach optimally allocates PMU placement in a stage-wise manner. The proposed approach also considers large-scale wind integration for effective grid state monitoring of wind generation dynamics. The proposed approach is implemented...... on the Danish power system projected for the year 2040. Furthermore, practical experience learnt from an optimal PMU placement project aimed at PMU placement in the Danish power system is presented, which is expected to provide insight of practical challenges at ground level that could be considered by PMU...

  20. Automatic identification of optimal marker genes for phenotypic and taxonomic groups of microorganisms.

    Directory of Open Access Journals (Sweden)

    Elad Segev

    Full Text Available Finding optimal markers for microorganisms important in the medical, agricultural, environmental or ecological fields is of great importance. Thousands of complete microbial genomes now available allow us, for the first time, to exhaustively identify marker proteins for groups of microbial organisms. In this work, we model the biological task as the well-known mathematical "hitting set" problem, solving it based on both greedy and randomized approximation algorithms. We identify unique markers for 17 phenotypic and taxonomic microbial groups, including proteins related to the nitrite reductase enzyme as markers for the non-anammox nitrifying bacteria group, and two transcription regulation proteins, nusG and yhiF, as markers for the Archaea and Escherichia/Shigella taxonomic groups, respectively. Additionally, we identify marker proteins for three subtypes of pathogenic E. coli, which previously had no known optimal markers. Practically, depending on the completeness of the database this algorithm can be used for identification of marker genes for any microbial group, these marker genes may be prime candidates for the understanding of the genetic basis of the group's phenotype or to help discover novel functions which are uniquely shared among a group of microbes. We show that our method is both theoretically and practically efficient, while establishing an upper bound on its time complexity and approximation ratio; thus, it promises to remain efficient and permit the identification of marker proteins that are specific to phenotypic or taxonomic groups, even as more and more bacterial genomes are being sequenced.

  1. Comparing the Selection and Placement of Best Management Practices in Improving Water Quality Using a Multiobjective Optimization and Targeting Method

    Directory of Open Access Journals (Sweden)

    Li-Chi Chiang

    2014-03-01

    Full Text Available Suites of Best Management Practices (BMPs are usually selected to be economically and environmentally efficient in reducing nonpoint source (NPS pollutants from agricultural areas in a watershed. The objective of this research was to compare the selection and placement of BMPs in a pasture-dominated watershed using multiobjective optimization and targeting methods. Two objective functions were used in the optimization process, which minimize pollutant losses and the BMP placement areas. The optimization tool was an integration of a multi-objective genetic algorithm (GA and a watershed model (Soil and Water Assessment Tool—SWAT. For the targeting method, an optimum BMP option was implemented in critical areas in the watershed that contribute the greatest pollutant losses. A total of 171 BMP combinations, which consist of grazing management, vegetated filter strips (VFS, and poultry litter applications were considered. The results showed that the optimization is less effective when vegetated filter strips (VFS are not considered, and it requires much longer computation times than the targeting method to search for optimum BMPs. Although the targeting method is effective in selecting and placing an optimum BMP, larger areas are needed for BMP implementation to achieve the same pollutant reductions as the optimization method.

  2. Optimization of ISSR Markers for Molecular DNA Fingerprinting in Aquilaria sp

    International Nuclear Information System (INIS)

    Azhar Mohamad; Muhammad Hanif Azhari; Siti Norhayati Ismail; Parween, K.S.A.S.

    2013-01-01

    Aquilaria sp. belongs to the Thymelaeaceae family and well distributed to Asia region. The species is a multipurpose use from root to shoot and becoming an economic important crop, which generates wide interest in understanding the genetic diversity of the species. Understanding of the effectiveness in differentiating DNA-based markers is an important step towards plant germplasm characterization and evaluation. It is becoming a prerequisite for more effective application of molecular marker techniques in breeding and mapping programs. Polymerase Chain Reaction (PCR)-based approaches are in demanding as its simplicity and requirement for only small quantities of sample genomic DNA. Inter-simple sequence repeats (ISRR) requires no prior genomic information as anchor template in producing multi-loci markers of tandem repeats for polymorphic patterns by PCR amplification which becoming a key of advantageous of ISSR primers. ISSR markers have shown rapid, simple, reproducible and inexpensive means in molecular taxonomy, conservation breeding and genetic diversity analysis. The ISSR for marker applications are essential to facilitate management, conservation and genetic improvement programs towards improvement of standard resin quality for perfume and or pharmaceutical industries. In this paper, a total of 100 ISSR primers were optimized by using Aquilaria malaccensis. Primers optimization resulted, 38 ISSR primers affirmative for the polymorphism evaluation study, which encountered both from specific and degenerate ISSR primers. Marker derived from ISSR profiling is a powerful method for identification and molecular classification of Aquilaria sp from species to accessions and further will useful in identifying any mutant lines derived from nature and/or mutagenesis activities. (author)

  3. Field-Based Optimal Placement of Antennas for Body-Worn Wireless Sensors

    Directory of Open Access Journals (Sweden)

    Łukasz Januszkiewicz

    2016-05-01

    Full Text Available We investigate a case of automated energy-budget-aware optimization of the physical position of nodes (sensors in a Wireless Body Area Network (WBAN. This problem has not been presented in the literature yet, as opposed to antenna and routing optimization, which are relatively well-addressed. In our research, which was inspired by a safety-critical application for firefighters, the sensor network consists of three nodes located on the human body. The nodes communicate over a radio link operating in the 2.4 GHz or 5.8 GHz ISM frequency band. Two sensors have a fixed location: one on the head (earlobe pulse oximetry and one on the arm (with accelerometers, temperature and humidity sensors, and a GPS receiver, while the position of the third sensor can be adjusted within a predefined region on the wearer’s chest. The path loss between each node pair strongly depends on the location of the nodes and is difficult to predict without performing a full-wave electromagnetic simulation. Our optimization scheme employs evolutionary computing. The novelty of our approach lies not only in the formulation of the problem but also in linking a fully automated optimization procedure with an electromagnetic simulator and a simplified human body model. This combination turns out to be a computationally effective solution, which, depending on the initial placement, has a potential to improve performance of our example sensor network setup by up to about 20 dB with respect to the path loss between selected nodes.

  4. Optimal training for emergency needle thoracostomy placement by prehospital personnel: didactic teaching versus a cadaver-based training program.

    Science.gov (United States)

    Grabo, Daniel; Inaba, Kenji; Hammer, Peter; Karamanos, Efstathios; Skiada, Dimitra; Martin, Matthew; Sullivan, Maura; Demetriades, Demetrios

    2014-09-01

    Tension pneumothorax can rapidly progress to cardiac arrest and death if not promptly recognized and appropriately treated. We sought to evaluate the effectiveness of traditional didactic slide-based lectures (SBLs) as compared with fresh tissue cadaver-based training (CBT) for placement of needle thoracostomy (NT). Forty randomly selected US Navy corpsmen were recruited to participate from incoming classes of the Navy Trauma Training Center at the LAC + USC Medical Center and were then randomized to one of two NT teaching methods. The following outcomes were compared between the two study arms: (1) time required to perform the procedure, (2) correct placement of the needle, and (3) magnitude of deviation from the correct position. During the study period, a total of 40 corpsmen were enrolled, 20 randomized to SBL and 20 to CBT arms. When outcomes were analyzed, time required to NT placement was not different between the two arms. Examination of the location of needle placement revealed marked differences between the two study groups. Only a minority of the SBL group (35%) placed the NT correctly in the second intercostal space. In comparison, the majority of corpsmen assigned to the CBT group demonstrated accurate placement in the second intercostal space (75%). In a CBT module, US Navy corpsmen were better trained to place NT accurately than their traditional didactic SBL counterparts. Further studies are indicated to identify the optimal components of effective simulation training for NT and other emergent interventions.

  5. Optimal placement and sizing of fixed and switched capacitor banks under non sinusoidal operating conditions

    International Nuclear Information System (INIS)

    Ladjevardi, M.; Masoum, M.A.S.; Fuchs, E.F.

    2004-01-01

    An iterative nonlinear algorithm is generated for optimal sizing and placement of fixed and switched capacitor banks on radial distribution lines in the presence of linear and nonlinear loads. The HARMFLOW algorithm and the maximum sensitivities selection method are used to solve the constrained optimizations problem with discrete variables. To limit the burden of calculations and improve convergence, the problem is decomposed into two subproblems. Objective functions include minimum system losses and capacitor cost while IEEE 519 power quality limits are used as constraints. Results are presented and analyzed for the 18 bus IEEE distorted system. The advantage of the proposed algorithm compared to the previous work is the consideration of harmonic couplings and reactions of actual nonlinear loads of the distribution system

  6. Comparison of metaheuristic techniques to determine optimal placement of biomass power plants

    International Nuclear Information System (INIS)

    Reche-Lopez, P.; Ruiz-Reyes, N.; Garcia Galan, S.; Jurado, F.

    2009-01-01

    This paper deals with the application and comparison of several metaheuristic techniques to optimize the placement and supply area of biomass-fueled power plants. Both, trajectory and population-based methods are applied for our goal. In particular, two well-known trajectory method, such as Simulated Annealing (SA) and Tabu Search (TS), and two commonly used population-based methods, such as Genetic Algorithms (GA) and Particle Swarm Optimization (PSO) are hereby considered. In addition, a new binary PSO algorithm has been proposed, which incorporates an inertia weight factor, like the classical continuous approach. The fitness function for the metaheuristics is the profitability index, defined as the ratio between the net present value and the initial investment. In this work, forest residues are considered as biomass source, and the problem constraints are: the generation system must be located inside the supply area, and its maximum electric power is 5 MW. The comparative results obtained by all considered metaheuristics are discussed. Random walk has also been assessed for the problem we deal with.

  7. Comparison of metaheuristic techniques to determine optimal placement of biomass power plants

    Energy Technology Data Exchange (ETDEWEB)

    Reche-Lopez, P.; Ruiz-Reyes, N.; Garcia Galan, S. [Telecommunication Engineering Department, University of Jaen Polytechnic School, C/ Alfonso X el Sabio 28, 23700 Linares, Jaen (Spain); Jurado, F. [Electrical Engineering Department, University of Jaen Polytechnic School, C/ Alfonso X el Sabio 28, 23700 Linares, Jaen (Spain)

    2009-08-15

    This paper deals with the application and comparison of several metaheuristic techniques to optimize the placement and supply area of biomass-fueled power plants. Both, trajectory and population-based methods are applied for our goal. In particular, two well-known trajectory method, such as Simulated Annealing (SA) and Tabu Search (TS), and two commonly used population-based methods, such as Genetic Algorithms (GA) and Particle Swarm Optimization (PSO) are hereby considered. In addition, a new binary PSO algorithm has been proposed, which incorporates an inertia weight factor, like the classical continuous approach. The fitness function for the metaheuristics is the profitability index, defined as the ratio between the net present value and the initial investment. In this work, forest residues are considered as biomass source, and the problem constraints are: the generation system must be located inside the supply area, and its maximum electric power is 5 MW. The comparative results obtained by all considered metaheuristics are discussed. Random walk has also been assessed for the problem we deal with. (author)

  8. Optimal Node Placement in Underwater Acoustic Sensor Network

    KAUST Repository

    Felemban, Muhamad

    2011-10-01

    Almost 70% of planet Earth is covered by water. A large percentage of underwater environment is unexplored. In the past two decades, there has been an increase in the interest of exploring and monitoring underwater life among scientists and in industry. Underwater operations are extremely difficult due to the lack of cheap and efficient means. Recently, Wireless Sensor Networks have been introduced in underwater environment applications. However, underwater communication via acoustic waves is subject to several performance limitations, which makes the relevant research issues very different from those on land. In this thesis, we investigate node placement for building an initial Underwater Wireless Sensor Network infrastructure. Firstly, we formulated the problem into a nonlinear mathematic program with objectives of minimizing the total transmission loss under a given number of sensor nodes and targeted volume. We conducted experiments to verify the proposed formulation, which is solved using Matlab optimization tool. We represented each node with a truncated octahedron to fill out the 3D space. The truncated octahedrons are tiled in the 3D space with each node in the center where locations of the nodes are given using 3D coordinates. Results are supported using ns-3 simulator. Results from simulation are consistent with the obtained results from mathematical model with less than 10% error.

  9. An RTT-Aware Virtual Machine Placement Method

    Directory of Open Access Journals (Sweden)

    Li Quan

    2017-12-01

    Full Text Available Virtualization is a key technology for mobile cloud computing (MCC and the virtual machine (VM is a core component of virtualization. VM provides a relatively independent running environment for different applications. Therefore, the VM placement problem focuses on how to place VMs on optimal physical machines, which ensures efficient use of resources and the quality of service, etc. Most previous work focuses on energy consumption, network traffic between VMs and so on and rarely consider the delay for end users’ requests. In contrast, the latency between requests and VMs is considered in this paper for the scenario of optimal VM placement in MCC. In order to minimize average RTT for all requests, the round-trip time (RTT is first used as the metric for the latency of requests. Based on our proposed RTT metric, an RTT-Aware VM placement algorithm is then proposed to minimize the average RTT. Furthermore, the case in which one of the core switches does not work is considered. A VM rescheduling algorithm is proposed to keep the average RTT lower and reduce the fluctuation of the average RTT. Finally, in the simulation study, our algorithm shows its advantage over existing methods, including random placement, the traffic-aware VM placement algorithm and the remaining utilization-aware algorithm.

  10. Optimum distributed generation placement with voltage sag effect minimization

    International Nuclear Information System (INIS)

    Biswas, Soma; Goswami, Swapan Kumar; Chatterjee, Amitava

    2012-01-01

    Highlights: ► A new optimal distributed generation placement algorithm is proposed. ► Optimal number, sizes and locations of the DGs are determined. ► Technical factors like loss, voltage sag problem are minimized. ► The percentage savings are optimized. - Abstract: The present paper proposes a new formulation for the optimum distributed generator (DG) placement problem which considers a hybrid combination of technical factors, like minimization of the line loss, reduction in the voltage sag problem, etc., and economical factors, like installation and maintenance cost of the DGs. The new formulation proposed is inspired by the idea that the optimum placement of the DGs can help in reducing and mitigating voltage dips in low voltage distribution networks. The problem is configured as a multi-objective, constrained optimization problem, where the optimal number of DGs, along with their sizes and bus locations, are simultaneously obtained. This problem has been solved using genetic algorithm, a traditionally popular stochastic optimization algorithm. A few benchmark systems radial and networked (like 34-bus radial distribution system, 30 bus loop distribution system and IEEE 14 bus system) are considered as the case study where the effectiveness of the proposed algorithm is aptly demonstrated.

  11. The Comparison of two models of markerplacement for identifying the rear foot angle in normal people with and without shoes during the stance phase of walking

    Directory of Open Access Journals (Sweden)

    2016-09-01

    Full Text Available Objective: The purpose of this study was to compare the two models of marker placement for identifying of rear foot angle in normal people with and without shoes during the different stage of stance phase of walking. Methods: Fifteen male students in Birjand University were selected based on Navicular Drop Index. After marker placement based on Clarke and Nigg models, the rear foot angle were recorded with two-dimensional analysis (Panasonic Camera from behind position while subjects walked with 1.7 m/s on a treadmill with and without shoes. For statistical analysis, independent samples t-test was used (p≤0.05. Results: The Results showed a significant difference in rear foot angle during the stance phase between the two models of Clarke and Nigg during walking with and without shoes (p≤0.001. Conclusion: Based on the results of the present study, due to their specific features care must be considered when using any of these two models to investigate the angular kinematics of the foot.

  12. Relay Placement for FSO Multihop DF Systems With Link Obstacles and Infeasible Regions

    KAUST Repository

    Zhu, Bingcheng; Cheng, Julian; Alouini, Mohamed-Slim; Wu, Lenan

    2015-01-01

    Optimal relay placement is studied for free-space optical multihop communication with link obstacles and infeasible regions. An optimal relay placement scheme is proposed to achieve the lowest outage probability, enable the links to bypass obstacles

  13. Optimization of well placement geothermal reservoirs using artificial intelligence

    Science.gov (United States)

    Akın, Serhat; Kok, Mustafa V.; Uraz, Irtek

    2010-06-01

    This research proposes a framework for determining the optimum location of an injection well using an inference method, artificial neural networks and a search algorithm to create a search space and locate the global maxima. A complex carbonate geothermal reservoir (Kizildere Geothermal field, Turkey) production history is used to evaluate the proposed framework. Neural networks are used as a tool to replicate the behavior of commercial simulators, by capturing the response of the field given a limited number of parameters such as temperature, pressure, injection location, and injection flow rate. A study on different network designs indicates that a combination of neural network and an optimization algorithm (explicit search with variable stepping) to capture local maxima can be used to locate a region or a location for optimum well placement. Results also indicate shortcomings and possible pitfalls associated with the approach. With the provided flexibility of the proposed workflow, it is possible to incorporate various parameters including injection flow rate, temperature, and location. For the field of study, optimum injection well location is found to be in the southeastern part of the field. Specific locations resulting from the workflow indicated a consistent search space, having higher values in that particular region. When studied with fixed flow rates (2500 and 4911 m 3/day), a search run through the whole field located two locations which are in the very same region resulting in consistent predictions. Further study carried out by incorporating effect of different flow rates indicates that the algorithm can be run in a particular region of interest and different flow rates may yield different locations. This analysis resulted with a new location in the same region and an optimum injection rate of 4000 m 3/day). It is observed that use of neural network, as a proxy to numerical simulator is viable for narrowing down or locating the area of interest for

  14. Relay Placement for FSO Multihop DF Systems With Link Obstacles and Infeasible Regions

    KAUST Repository

    Zhu, Bingcheng

    2015-05-19

    Optimal relay placement is studied for free-space optical multihop communication with link obstacles and infeasible regions. An optimal relay placement scheme is proposed to achieve the lowest outage probability, enable the links to bypass obstacles of various geometric shapes, and place the relay nodes in specified available regions. When the number of relay nodes is large, the searching space can grow exponentially, and thus, a grouping optimization technique is proposed to reduce the searching time. We numerically demonstrate that the grouping optimization can provide suboptimal solutions close to the optimal solutions, but the average searching time linearly grows with the number of relay nodes. Two useful theorems are presented to reveal insights into the optimal relay locations. Simulation results show that our proposed optimization framework can effectively provide desirable solution to the problem of optimal relay nodes placement. © 2015 IEEE.

  15. Virtual sensors for active noise control in acoustic-structural coupled enclosures using structural sensing: part II--Optimization of structural sensor placement.

    Science.gov (United States)

    Halim, Dunant; Cheng, Li; Su, Zhongqing

    2011-04-01

    The work proposed an optimization approach for structural sensor placement to improve the performance of vibro-acoustic virtual sensor for active noise control applications. The vibro-acoustic virtual sensor was designed to estimate the interior sound pressure of an acoustic-structural coupled enclosure using structural sensors. A spectral-spatial performance metric was proposed, which was used to quantify the averaged structural sensor output energy of a vibro-acoustic system excited by a spatially varying point source. It was shown that (i) the overall virtual sensing error energy was contributed additively by the modal virtual sensing error and the measurement noise energy; (ii) each of the modal virtual sensing error system was contributed by both the modal observability levels for the structural sensing and the target acoustic virtual sensing; and further (iii) the strength of each modal observability level was influenced by the modal coupling and resonance frequencies of the associated uncoupled structural/cavity modes. An optimal design of structural sensor placement was proposed to achieve sufficiently high modal observability levels for certain important panel- and cavity-controlled modes. Numerical analysis on a panel-cavity system demonstrated the importance of structural sensor placement on virtual sensing and active noise control performance, particularly for cavity-controlled modes.

  16. Optimal Product Placement.

    Science.gov (United States)

    Hsu, Chia-Ling; Matta, Rafael; Popov, Sergey V; Sogo, Takeharu

    2017-01-01

    We model a market, such as an online software market, in which an intermediary connects sellers and buyers by displaying sellers' products. With two vertically-differentiated products, an intermediary can place either: (1) one product, not necessarily the better one, on the first page, and the other hidden on the second page; or (2) both products on the first page. We show that it can be optimal for the intermediary to obfuscate a product-possibly the better one-since this weakens price competition and allows the sellers to extract a greater surplus from buyers; however, it is not socially optimal. The choice of which one to obfuscate depends on the distribution of search costs.

  17. Control of chaos in permanent magnet synchronous motor by using optimal Lyapunov exponents placement

    Energy Technology Data Exchange (ETDEWEB)

    Ataei, Mohammad, E-mail: ataei@eng.ui.ac.i [Department of Electrical Engineering, Faculty of Engineering, University of Isfahan, Hezar-Jerib St., Postal Code 8174673441, Isfahan (Iran, Islamic Republic of); Kiyoumarsi, Arash, E-mail: kiyoumarsi@eng.ui.ac.i [Department of Electrical Engineering, Faculty of Engineering, University of Isfahan, Hezar-Jerib St., Postal Code 8174673441, Isfahan (Iran, Islamic Republic of); Ghorbani, Behzad, E-mail: behzad.ghorbani63@gmail.co [Department of Control Engineering, Najafabad Azad University, Najafabad, Isfahan (Iran, Islamic Republic of)

    2010-09-13

    Permanent Magnet Synchronous Motor (PMSM) experiences chaotic behavior for a certain range of its parameters. In this case, since the performance of the PMSM degrades, the chaos should be eliminated. In this Letter, the control of the undesirable chaos in PMSM using Lyapunov exponents (LEs) placement is proposed that is also improved by choosing optimal locations of the LEs in the sense of predefined cost function. Moreover, in order to provide the physical realization of the method, nonlinear parameter estimator for the system is suggested. Finally, to show the effectiveness of the proposed methodology, the simulation results for applying this control strategy are provided.

  18. Data-driven sensor placement from coherent fluid structures

    Science.gov (United States)

    Manohar, Krithika; Kaiser, Eurika; Brunton, Bingni W.; Kutz, J. Nathan; Brunton, Steven L.

    2017-11-01

    Optimal sensor placement is a central challenge in the prediction, estimation and control of fluid flows. We reinterpret sensor placement as optimizing discrete samples of coherent fluid structures for full state reconstruction. This permits a drastic reduction in the number of sensors required for faithful reconstruction, since complex fluid interactions can often be described by a small number of coherent structures. Our work optimizes point sensors using the pivoted matrix QR factorization to sample coherent structures directly computed from flow data. We apply this sampling technique in conjunction with various data-driven modal identification methods, including the proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD). In contrast to POD-based sensors, DMD demonstrably enables the optimization of sensors for prediction in systems exhibiting multiple scales of dynamics. Finally, reconstruction accuracy from pivot sensors is shown to be competitive with sensors obtained using traditional computationally prohibitive optimization methods.

  19. Optimized baffle and aperture placement in neutral beamlines

    International Nuclear Information System (INIS)

    Stone, R.; Duffy, T.; Vetrovec, J.

    1983-01-01

    Most neutral beamlines contain an iron-core ion-bending magnet that requires shielding between the end of the neutralizer and this magnet. This shielding allows the gas pressure to drop prior to the beam entering the magnet and therefore reduces beam losses in this drift region. We have found that the beam losses can be reduced even further by eliminating the iron-core magnet and the magnetic shielding altogether. The required bending field can be supplied by current coils without the iron poles. In addition, placement of the baffles and apertures can affect the cold gas entering the plasma region and the losses in the neutral beam due to re-ionization. In our study we varied the placement of the baffles, which determine the amount of pumping in each chamber, and the apertures, which determine the beam loss. Our results indicate that a baffle/aperture configuration can be set for either minimum cold gas into the plasma region or minimum beam losses, but not both

  20. Multi-projector auto-calibration and placement optimization for non-planar surfaces

    Science.gov (United States)

    Li, Dong; Xie, Jinghui; Zhao, Lu; Zhou, Lijing; Weng, Dongdong

    2015-10-01

    Non-planar projection has been widely applied in virtual reality and digital entertainment and exhibitions because of its flexible layout and immersive display effects. Compared with planar projection, a non-planar projection is more difficult to achieve because projector calibration and image distortion correction are difficult processes. This paper uses a cylindrical screen as an example to present a new method for automatically calibrating a multi-projector system in a non-planar environment without using 3D reconstruction. This method corrects the geometric calibration error caused by the screen's manufactured imperfections, such as an undulating surface or a slant in the vertical plane. In addition, based on actual projection demand, this paper presents the overall performance evaluation criteria for the multi-projector system. According to these criteria, we determined the optimal placement for the projectors. This method also extends to surfaces that can be parameterized, such as spheres, ellipsoids, and paraboloids, and demonstrates a broad applicability.

  1. Optimal Placement and Sizing of Renewable Distributed Generations and Capacitor Banks into Radial Distribution Systems

    Directory of Open Access Journals (Sweden)

    Mahesh Kumar

    2017-06-01

    Full Text Available In recent years, renewable types of distributed generation in the distribution system have been much appreciated due to their enormous technical and environmental advantages. This paper proposes a methodology for optimal placement and sizing of renewable distributed generation(s (i.e., wind, solar and biomass and capacitor banks into a radial distribution system. The intermittency of wind speed and solar irradiance are handled with multi-state modeling using suitable probability distribution functions. The three objective functions, i.e., power loss reduction, voltage stability improvement, and voltage deviation minimization are optimized using advanced Pareto-front non-dominated sorting multi-objective particle swarm optimization method. First a set of non-dominated Pareto-front data are called from the algorithm. Later, a fuzzy decision technique is applied to extract the trade-off solution set. The effectiveness of the proposed methodology is tested on the standard IEEE 33 test system. The overall results reveal that combination of renewable distributed generations and capacitor banks are dominant in power loss reduction, voltage stability and voltage profile improvement.

  2. Derivative load voltage and particle swarm optimization to determine optimum sizing and placement of shunt capacitor in improving line losses

    Directory of Open Access Journals (Sweden)

    Mohamed Milad Baiek

    2016-12-01

    Full Text Available The purpose of this research is to study optimal size and placement of shunt capacitor in order to minimize line loss. Derivative load bus voltage was calculated to determine the sensitive load buses which further being optimum with the placement of shunt capacitor. Particle swarm optimization (PSO was demonstrated on the IEEE 14 bus power system to find optimum size of shunt capacitor in reducing line loss. The objective function was applied to determine the proper placement of capacitor and get satisfied solutions towards constraints. The simulation was run over Matlab under two scenarios namely base case and increasing 100% load. Derivative load bus voltage was simulated to determine the most sensitive load bus. PSO was carried out to determine the optimum sizing of shunt capacitor at the most sensitive bus. The results have been determined that the most sensitive bus was bus number 14 for the base case and increasing 100% load. The optimum sizing was 8.17 Mvar for the base case and 23.98 Mvar for increasing load about 100%. Line losses were able to reduce approximately 0.98% for the base case and increasing 100% load reduced about 3.16%. The proposed method was also proven as a better result compared with harmony search algorithm (HSA method. HSA method recorded loss reduction ratio about 0.44% for the base case and 2.67% when the load was increased by 100% while PSO calculated loss reduction ratio about 1.12% and 4.02% for the base case and increasing 100% load respectively. The result of this study will support the previous study and it is concluded that PSO was successfully able to solve some engineering problems as well as to find a solution in determining shunt capacitor sizing on the power system simply and accurately compared with other evolutionary optimization methods.

  3. A Framework for Optimizing the Placement of Tidal Turbines

    Science.gov (United States)

    Nelson, K. S.; Roberts, J.; Jones, C.; James, S. C.

    2013-12-01

    Power generation with marine hydrokinetic (MHK) current energy converters (CECs), often in the form of underwater turbines, is receiving growing global interest. Because of reasonable investment, maintenance, reliability, and environmental friendliness, this technology can contribute to national (and global) energy markets and is worthy of research investment. Furthermore, in remote areas, small-scale MHK energy from river, tidal, or ocean currents can provide a local power supply. However, little is known about the potential environmental effects of CEC operation in coastal embayments, estuaries, or rivers, or of the cumulative impacts of these devices on aquatic ecosystems over years or decades of operation. There is an urgent need for practical, accessible tools and peer-reviewed publications to help industry and regulators evaluate environmental impacts and mitigation measures, while establishing best sitting and design practices. Sandia National Laboratories (SNL) and Sea Engineering, Inc. (SEI) have investigated the potential environmental impacts and performance of individual tidal energy converters (TECs) in Cobscook Bay, ME; TECs are a subset of CECs that are specifically deployed in tidal channels. Cobscook Bay is the first deployment location of Ocean Renewable Power Company's (ORPC) TidGenTM unit. One unit is currently in place with four more to follow. Together, SNL and SEI built a coarse-grid, regional-scale model that included Cobscook Bay and all other landward embayments using the modeling platform SNL-EFDC. Within SNL-EFDC tidal turbines are represented using a unique set of momentum extraction, turbulence generation, and turbulence dissipation equations at TEC locations. The global model was then coupled to a local-scale model that was centered on the proposed TEC deployment locations. An optimization frame work was developed that used the refined model to determine optimal device placement locations that maximized array performance. Within the

  4. Enhanced nonlinearity interval mapping scheme for high-performance simulation-optimization of watershed-scale BMP placement

    Science.gov (United States)

    Zou, Rui; Riverson, John; Liu, Yong; Murphy, Ryan; Sim, Youn

    2015-03-01

    Integrated continuous simulation-optimization models can be effective predictors of a process-based responses for cost-benefit optimization of best management practices (BMPs) selection and placement. However, practical application of simulation-optimization model is computationally prohibitive for large-scale systems. This study proposes an enhanced Nonlinearity Interval Mapping Scheme (NIMS) to solve large-scale watershed simulation-optimization problems several orders of magnitude faster than other commonly used algorithms. An efficient interval response coefficient (IRC) derivation method was incorporated into the NIMS framework to overcome a computational bottleneck. The proposed algorithm was evaluated using a case study watershed in the Los Angeles County Flood Control District. Using a continuous simulation watershed/stream-transport model, Loading Simulation Program in C++ (LSPC), three nested in-stream compliance points (CP)—each with multiple Total Maximum Daily Loads (TMDL) targets—were selected to derive optimal treatment levels for each of the 28 subwatersheds, so that the TMDL targets at all the CP were met with the lowest possible BMP implementation cost. Genetic Algorithm (GA) and NIMS were both applied and compared. The results showed that the NIMS took 11 iterations (about 11 min) to complete with the resulting optimal solution having a total cost of 67.2 million, while each of the multiple GA executions took 21-38 days to reach near optimal solutions. The best solution obtained among all the GA executions compared had a minimized cost of 67.7 million—marginally higher, but approximately equal to that of the NIMS solution. The results highlight the utility for decision making in large-scale watershed simulation-optimization formulations.

  5. Temperature Simulation of Greenhouse with CFD Methods and Optimal Sensor Placement

    Directory of Open Access Journals (Sweden)

    Yanzheng Liu

    2014-03-01

    Full Text Available The accuracy of information monitoring is significant to increase the effect of Greenhouse Environment Control. In this paper, by taking simulation for the temperature field in the greenhouse as an example, the CFD (Computational Fluid Dynamics simulation model for measuring the microclimate environment of greenhouse with the principle of thermal environment formation was established, and the temperature distributions under the condition of mechanical ventilation was also simulated. The results showed that the CFD model and its solution simulated for greenhouse thermal environment could describe the changing process of temperature environment within the greenhouse; the most suitable turbulent simulation model was the standard k?? model. Under the condition of mechanical ventilation, the average deviation between the simulated value and the measured value was 0.6, which was 4.5 percent of the measured value. The distribution of temperature filed had obvious layering structures, and the temperature in the greenhouse model decreased gradually from the periphery to the center. Based on these results, the sensor number and the optimal sensor placement were determined with CFD simulation method.

  6. FPGA Congestion-Driven Placement Refinement

    Energy Technology Data Exchange (ETDEWEB)

    Vicente de, J.

    2005-07-01

    The routing congestion usually limits the complete proficiency of the FPGA logic resources. A key question can be formulated regarding the benefits of estimating the congestion at placement stage. In the last years, it is gaining acceptance the idea of a detailed placement taking into account congestion. In this paper, we resort to the Thermodynamic Simulated Annealing (TSA) algorithm to perform a congestion-driven placement refinement on the top of the common Bounding-Box pre optimized solution. The adaptive properties of TSA allow the search to preserve the solution quality of the pre optimized solution while improving other fine-grain objectives. Regarding the cost function two approaches have been considered. In the first one Expected Occupation (EO), a detailed probabilistic model to account for channel congestion is evaluated. We show that in spite of the minute detail of EO, the inherent uncertainty of this probabilistic model impedes to relieve congestion beyond the sole application of the Bounding-Box cost function. In the second approach we resort to the fast Rectilinear Steiner Regions algorithm to perform not an estimation but a measurement of the global routing congestion. This second strategy allows us to successfully reduce the requested channel width for a set of benchmark circuits with respect to the widespread Versatile Place and Route (VPR) tool. (Author) 31 refs.

  7. An Effective Mechanism for Virtual Machine Placement using Aco in IAAS Cloud

    Science.gov (United States)

    Shenbaga Moorthy, Rajalakshmi; Fareentaj, U.; Divya, T. K.

    2017-08-01

    Cloud computing provides an effective way to dynamically provide numerous resources to meet customer demands. A major challenging problem for cloud providers is designing efficient mechanisms for optimal virtual machine Placement (OVMP). Such mechanisms enable the cloud providers to effectively utilize their available resources and obtain higher profits. In order to provide appropriate resources to the clients an optimal virtual machine placement algorithm is proposed. Virtual machine placement is NP-Hard problem. Such NP-Hard problem can be solved using heuristic algorithm. In this paper, Ant Colony Optimization based virtual machine placement is proposed. Our proposed system focuses on minimizing the cost spending in each plan for hosting virtual machines in a multiple cloud provider environment and the response time of each cloud provider is monitored periodically, in such a way to minimize delay in providing the resources to the users. The performance of the proposed algorithm is compared with greedy mechanism. The proposed algorithm is simulated in Eclipse IDE. The results clearly show that the proposed algorithm minimizes the cost, response time and also number of migrations.

  8. Optimal placement, sizing, and daily charge/discharge of battery energy storage in low voltage distribution network with high photovoltaic penetration

    DEFF Research Database (Denmark)

    Jannesar, Mohammad Rasol; Sedighi, Alireza; Savaghebi, Mehdi

    2018-01-01

    when photovoltaic penetration is increased in low voltage distribution network. Local battery energy storage system can mitigate these disadvantages and as a result, improve the system operation. For this purpose, battery energy storage system is charged when production of photovoltaic is more than...... consumers’ demands and discharged when consumers’ demands are increased. Since the price of battery energy storage system is high, economic, environmental, and technical objectives should be considered together for its placement and sizing. In this paper, optimal placement, sizing, and daily (24 h) charge......Proper installation of rooftop photovoltaic generation in distribution networks can improve voltage profile, reduce energy losses, and enhance the reliability. But, on the other hand, some problems regarding harmonic distortion, voltage magnitude, reverse power flow, and energy losses can arise...

  9. Neural network for optimal capacitor placement and its impact on power quality in electric distribution systems

    International Nuclear Information System (INIS)

    Mohamed, A.A.E.S.

    2013-01-01

    Capacitors are widely installed in distribution systems for reactive power compensation to achieve power and energy loss reduction, voltage regulation and system capacity release. The extent of these benefits depends greatly on how the capacitors are placed on the system. The problem of how to place capacitors on the system such that these benefits are achieved and maximized against the cost associated with the capacitor placement is termed the general capacitor placement problem. The capacitor placement problem has been formulated as the maximization of the savings resulted from reduction in both peak power and energy losses considering capacitor installation cost and maintaining the buses voltage within acceptable limits. After an appropriate analysis, the optimization problem was formulated in a quadratic form. For solving capacitor placement a new combinatorial heuristic and quadratic programming technique has been presented and applied in the MATLAB software. The proposed strategy was applied on two different radial distribution feeders. The results have been compared with previous works. The comparison showed the validity and the effectiveness of this strategy. Secondly, two artificial intelligence techniques for predicting the capacitor switching state in radial distribution feeders have been investigated; one is based on basis Radial Basis Neural Network (RBNN) and the other is based on Adaptive Neuro-Fuzzy Inference System (ANFIS). The ANFIS technique gives better results with a minimum total error compared to RBNN. The learning duration of ANFIS was very short than the neural network case. It implied that ANFIS reaches to the target faster than neural network. Thirdly, an artificial intelligence (RBNN) approach for estimation of transient overvoltage during capacitor switching has been studied. The artificial intelligence approach estimated the transient overvoltages with a minimum error in a short computational time. Finally, a capacitor switching

  10. Sensor Placement via Optimal Experiment Design in EMI Sensing of Metallic Objects

    Directory of Open Access Journals (Sweden)

    Lin-Ping Song

    2016-01-01

    Full Text Available This work, under the optimal experimental design framework, investigates the sensor placement problem that aims to guide electromagnetic induction (EMI sensing of multiple objects. We use the linearized model covariance matrix as a measure of estimation error to present a sequential experimental design (SED technique. The technique recursively minimizes data misfit to update model parameters and maximizes an information gain function for a future survey relative to previous surveys. The fundamental process of the SED seeks to increase weighted sensitivities to targets when placing sensors. The synthetic and field experiments demonstrate that SED can be used to guide the sensing process for an effective interrogation. It also can serve as a theoretic basis to improve empirical survey operation. We further study the sensitivity of the SED to the number of objects within the sensing range. The tests suggest that an appropriately overrepresented model about expected anomalies might be a feasible choice.

  11. On the use of PGD for optimal control applied to automated fibre placement

    Science.gov (United States)

    Bur, N.; Joyot, P.

    2017-10-01

    Automated Fibre Placement (AFP) is an incipient manufacturing process for composite structures. Despite its concep-tual simplicity it involves many complexities related to the necessity of melting the thermoplastic at the interface tape-substrate, ensuring the consolidation that needs the diffusion of molecules and control the residual stresses installation responsible of the residual deformations of the formed parts. The optimisation of the process and the determination of the process window cannot be achieved in a traditional way since it requires a plethora of trials/errors or numerical simulations, because there are many parameters involved in the characterisation of the material and the process. Using reduced order modelling such as the so called Proper Generalised Decomposition method, allows the construction of multi-parametric solution taking into account many parameters. This leads to virtual charts that can be explored on-line in real time in order to perform process optimisation or on-line simulation-based control. Thus, for a given set of parameters, determining the power leading to an optimal temperature becomes easy. However, instead of controlling the power knowing the temperature field by particularizing an abacus, we propose here an approach based on optimal control: we solve by PGD a dual problem from heat equation and optimality criteria. To circumvent numerical issue due to ill-conditioned system, we propose an algorithm based on Uzawa's method. That way, we are able to solve the dual problem, setting the desired state as an extra-coordinate in the PGD framework. In a single computation, we get both the temperature field and the required heat flux to reach a parametric optimal temperature on a given zone.

  12. Observability-Based Guidance and Sensor Placement

    Science.gov (United States)

    Hinson, Brian T.

    Control system performance is highly dependent on the quality of sensor information available. In a growing number of applications, however, the control task must be accomplished with limited sensing capabilities. This thesis addresses these types of problems from a control-theoretic point-of-view, leveraging system nonlinearities to improve sensing performance. Using measures of observability as an information quality metric, guidance trajectories and sensor distributions are designed to improve the quality of sensor information. An observability-based sensor placement algorithm is developed to compute optimal sensor configurations for a general nonlinear system. The algorithm utilizes a simulation of the nonlinear system as the source of input data, and convex optimization provides a scalable solution method. The sensor placement algorithm is applied to a study of gyroscopic sensing in insect wings. The sensor placement algorithm reveals information-rich areas on flexible insect wings, and a comparison to biological data suggests that insect wings are capable of acting as gyroscopic sensors. An observability-based guidance framework is developed for robotic navigation with limited inertial sensing. Guidance trajectories and algorithms are developed for range-only and bearing-only navigation that improve navigation accuracy. Simulations and experiments with an underwater vehicle demonstrate that the observability measure allows tuning of the navigation uncertainty.

  13. Determination of anatomic landmarks for optimal placement in captive-bolt euthanasia of goats.

    Science.gov (United States)

    Plummer, Paul J; Shearer, Jan K; Kleinhenz, Katie E; Shearer, Leslie C

    2018-03-01

    OBJECTIVE To determine the optimal anatomic site and directional aim of a penetrating captive bolt (PCB) for euthanasia of goats. SAMPLE 8 skulls from horned and polled goat cadavers and 10 anesthetized horned and polled goats scheduled to be euthanized at the end of a teaching laboratory. PROCEDURES Sagittal sections of cadaver skulls from 8 horned and polled goats were used to determine the ideal anatomic site and aiming of a PCB to maximize damage to the midbrain region of the brainstem for euthanasia. Anatomic sites for ideal placement and directional aiming were confirmed by use of 10 anesthetized horned and polled goats. RESULTS Clinical observation and postmortem examination of the sagittal sections of skulls from the 10 anesthetized goats that were euthanized confirmed that perpendicular placement and firing of a PCB at the intersection of 2 lines, each drawn from the lateral canthus of 1 eye to the middle of the base of the opposite ear, resulted in consistent disruption of the midbrain and thalamus in all goats. Immediate cessation of breathing, followed by a loss of heartbeat in all 10 of the anesthetized goats, confirmed that use of this site consistently resulted in effective euthanasia. CONCLUSIONS AND CLINICAL RELEVANCE Damage to the brainstem and key adjacent structures may be accomplished by firing a PCB perpendicular to the skull over the anatomic site identified at the intersection of 2 lines, each drawn from the lateral canthus of 1 eye to the middle of the base of the opposite ear.

  14. Particle swarm optimization algorithm for simultaneous optimal placement and sizing of shunt active power conditioner (APC) and shunt capacitor inharmonic distorted distribution system

    Institute of Scientific and Technical Information of China (English)

    Mohammadi Mohammad

    2017-01-01

    Due to development of distribution systems and increase in electricity demand, the use of capacitor banks increases. From the other point of view, nonlinear loads generate and inject considerable harmonic currents into power system. Under this condition if capacitor banks are not properly selected and placed in the power system, they could amplify and propagate these harmonics and deteriorate power quality to unacceptable levels. With attention of disadvantages of passive filters, such as occurring resonance, nowadays the usage of this type of harmonic compensator is restricted. On the other side, one of parallel multi-function compensating devices which are recently used in distribution system to mitigate voltage sag and harmonic distortion, performs power factor correction, and improves the overall power quality as active power conditioner (APC). Therefore, the utilization of APC in harmonic distorted system can affect and change the optimal location and size of shunt capacitor bank under harmonic distortion condition. This paper presents an optimization algorithm for improvement of power quality using simultaneous optimal placement and sizing of APC and shunt capacitor banks in radial distribution networks in the presence of voltage and current harmonics. The algorithm is based on particle swarm optimization (PSO). The objective function includes the cost of power losses, energy losses and those of the capacitor banks and APCs.

  15. Optimal PMU placement using topology transformation method in power systems

    Directory of Open Access Journals (Sweden)

    Nadia H.A. Rahman

    2016-09-01

    Full Text Available Optimal phasor measurement units (PMUs placement involves the process of minimizing the number of PMUs needed while ensuring the entire power system completely observable. A power system is identified observable when the voltages of all buses in the power system are known. This paper proposes selection rules for topology transformation method that involves a merging process of zero-injection bus with one of its neighbors. The result from the merging process is influenced by the selection of bus selected to merge with the zero-injection bus. The proposed method will determine the best candidate bus to merge with zero-injection bus according to the three rules created in order to determine the minimum number of PMUs required for full observability of the power system. In addition, this paper also considered the case of power flow measurements. The problem is formulated as integer linear programming (ILP. The simulation for the proposed method is tested by using MATLAB for different IEEE bus systems. The explanation of the proposed method is demonstrated by using IEEE 14-bus system. The results obtained in this paper proved the effectiveness of the proposed method since the number of PMUs obtained is comparable with other available techniques.

  16. Optimal PMU placement using topology transformation method in power systems.

    Science.gov (United States)

    Rahman, Nadia H A; Zobaa, Ahmed F

    2016-09-01

    Optimal phasor measurement units (PMUs) placement involves the process of minimizing the number of PMUs needed while ensuring the entire power system completely observable. A power system is identified observable when the voltages of all buses in the power system are known. This paper proposes selection rules for topology transformation method that involves a merging process of zero-injection bus with one of its neighbors. The result from the merging process is influenced by the selection of bus selected to merge with the zero-injection bus. The proposed method will determine the best candidate bus to merge with zero-injection bus according to the three rules created in order to determine the minimum number of PMUs required for full observability of the power system. In addition, this paper also considered the case of power flow measurements. The problem is formulated as integer linear programming (ILP). The simulation for the proposed method is tested by using MATLAB for different IEEE bus systems. The explanation of the proposed method is demonstrated by using IEEE 14-bus system. The results obtained in this paper proved the effectiveness of the proposed method since the number of PMUs obtained is comparable with other available techniques.

  17. Optimizing aspects of pedestrian traffic in building designs

    KAUST Repository

    Rodriguez, Samuel

    2013-11-01

    In this work, we investigate aspects of building design that can be optimized. Architectural features that we explore include pillar placement in simple corridors, doorway placement in buildings, and agent placement for information dispersement in an evacuation. The metrics utilized are tuned to the specific scenarios we study, which include continuous flow pedestrian movement and building evacuation. We use Multidimensional Direct Search (MDS) optimization with an extreme barrier criteria to find optimal placements while enforcing building constraints. © 2013 IEEE.

  18. Optimizing aspects of pedestrian traffic in building designs

    KAUST Repository

    Rodriguez, Samuel; Yinghua Zhang,; Gans, Nicholas; Amato, Nancy M.

    2013-01-01

    In this work, we investigate aspects of building design that can be optimized. Architectural features that we explore include pillar placement in simple corridors, doorway placement in buildings, and agent placement for information dispersement in an evacuation. The metrics utilized are tuned to the specific scenarios we study, which include continuous flow pedestrian movement and building evacuation. We use Multidimensional Direct Search (MDS) optimization with an extreme barrier criteria to find optimal placements while enforcing building constraints. © 2013 IEEE.

  19. Improved Relay Node Placement Algorithm for Wireless Sensor Networks Application in Wind Farm

    DEFF Research Database (Denmark)

    Chen, Qinyin; Hu, Y.; Chen, Zhe

    2013-01-01

    -tolerance. Each wind turbine has a potentially large number of data points needing to be monitored and collected, as farms continue to increase in scale; distances between turbines can reach several hundred meters. Optimal placement of relays in a large farm requires an efficient algorithmic solution. A relay...... node placement algorithm is proposed in this paper to approximate the optimal position for relays connecting each turbine. However, constraints are then required to prevent relay nodes being overloaded in 3-dimensions. The algorithm is extended to 3-dimensional Euclidean space for this optimal relay...

  20. Optimal placement of capacitors in a radial network using conic and mixed integer linear programming

    Energy Technology Data Exchange (ETDEWEB)

    Jabr, R.A. [Electrical, Computer and Communication Engineering Department, Notre Dame University, P.O. Box: 72, Zouk Mikhael, Zouk Mosbeh (Lebanon)

    2008-06-15

    This paper considers the problem of optimally placing fixed and switched type capacitors in a radial distribution network. The aim of this problem is to minimize the costs associated with capacitor banks, peak power, and energy losses whilst satisfying a pre-specified set of physical and technical constraints. The proposed solution is obtained using a two-phase approach. In phase-I, the problem is formulated as a conic program in which all nodes are candidates for placement of capacitor banks whose sizes are considered as continuous variables. A global solution of the phase-I problem is obtained using an interior-point based conic programming solver. Phase-II seeks a practical optimal solution by considering capacitor sizes as discrete variables. The problem in this phase is formulated as a mixed integer linear program based on minimizing the L1-norm of deviations from the phase-I state variable values. The solution to the phase-II problem is obtained using a mixed integer linear programming solver. The proposed method is validated via extensive comparisons with previously published results. (author)

  1. A Robust Optimization Based Energy-Aware Virtual Network Function Placement Proposal for Small Cell 5G Networks with Mobile Edge Computing Capabilities

    Directory of Open Access Journals (Sweden)

    Bego Blanco

    2017-01-01

    Full Text Available In the context of cloud-enabled 5G radio access networks with network function virtualization capabilities, we focus on the virtual network function placement problem for a multitenant cluster of small cells that provide mobile edge computing services. Under an emerging distributed network architecture and hardware infrastructure, we employ cloud-enabled small cells that integrate microservers for virtualization execution, equipped with additional hardware appliances. We develop an energy-aware placement solution using a robust optimization approach based on service demand uncertainty in order to minimize the power consumption in the system constrained by network service latency requirements and infrastructure terms. Then, we discuss the results of the proposed placement mechanism in 5G scenarios that combine several service flavours and robust protection values. Once the impact of the service flavour and robust protection on the global power consumption of the system is analyzed, numerical results indicate that our proposal succeeds in efficiently placing the virtual network functions that compose the network services in the available hardware infrastructure while fulfilling service constraints.

  2. Mechanical Elongation of the Small Intestine: Evaluation of Techniques for Optimal Screw Placement in a Rodent Model

    Directory of Open Access Journals (Sweden)

    P. A. Hausbrandt

    2013-01-01

    Full Text Available Introduction. The aim of this study was to evaluate techniques and establish an optimal method for mechanical elongation of small intestine (MESI using screws in a rodent model in order to develop a potential therapy for short bowel syndrome (SBS. Material and Methods. Adult female Sprague Dawley rats (n=24 with body weight from 250 to 300 g (Σ=283 were evaluated using 5 different groups in which the basic denominator for the technique involved the fixation of a blind loop of the intestine on the abdominal wall with the placement of a screw in the lumen secured to the abdominal wall. Results. In all groups with accessible screws, the rodents removed the implants despite the use of washers or suits to prevent removal. Subcutaneous placement of the screw combined with antibiotic treatment and dietary modifications was finally successful. In two animals autologous transplantation of the lengthened intestinal segment was successful. Discussion. While the rodent model may provide useful basic information on mechanical intestinal lengthening, further investigations should be performed in larger animals to make use of the translational nature of MESI in human SBS treatment.

  3. Sensor Placement Optimization using Chama

    Energy Technology Data Exchange (ETDEWEB)

    Klise, Katherine A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Geotechnology and Engineering Dept.; Nicholson, Bethany L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Discrete Math and Optimization Dept.; Laird, Carl Damon [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Discrete Math and Optimization Dept.

    2017-10-01

    Continuous or regularly scheduled monitoring has the potential to quickly identify changes in the environment. However, even with low - cost sensors, only a limited number of sensors can be deployed. The physical placement of these sensors, along with the sensor technology and operating conditions, can have a large impact on the performance of a monitoring strategy. Chama is an open source Python package which includes mixed - integer, stochastic programming formulations to determine sensor locations and technology that maximize monitoring effectiveness. The methods in Chama are general and can be applied to a wide range of applications. Chama is currently being used to design sensor networks to monitor airborne pollutants and to monitor water quality in water distribution systems. The following documentation includes installation instructions and examples, description of software features, and software license. The software is intended to be used by regulatory agencies, industry, and the research community. It is assumed that the reader is familiar with the Python Programming Language. References are included for addit ional background on software components. Online documentation, hosted at http://chama.readthedocs.io/, will be updated as new features are added. The online version includes API documentation .

  4. Ensemble-based data assimilation and optimal sensor placement for scalar source reconstruction

    Science.gov (United States)

    Mons, Vincent; Wang, Qi; Zaki, Tamer

    2017-11-01

    Reconstructing the characteristics of a scalar source from limited remote measurements in a turbulent flow is a problem of great interest for environmental monitoring, and is challenging due to several aspects. Firstly, the numerical estimation of the scalar dispersion in a turbulent flow requires significant computational resources. Secondly, in actual practice, only a limited number of observations are available, which generally makes the corresponding inverse problem ill-posed. Ensemble-based variational data assimilation techniques are adopted to solve the problem of scalar source localization in a turbulent channel flow at Reτ = 180 . This approach combines the components of variational data assimilation and ensemble Kalman filtering, and inherits the robustness from the former and the ease of implementation from the latter. An ensemble-based methodology for optimal sensor placement is also proposed in order to improve the condition of the inverse problem, which enhances the performances of the data assimilation scheme. This work has been partially funded by the Office of Naval Research (Grant N00014-16-1-2542) and by the National Science Foundation (Grant 1461870).

  5. Observability-Enhanced PMU Placement Considering Conventional Measurements and Contingencies

    Directory of Open Access Journals (Sweden)

    M. Esmaili

    2014-12-01

    Full Text Available Phasor Measurement Units (PMUs are in growing attention in recent power systems because of their paramount abilities in state estimation. PMUs are placed in existing power systems where there are already installed conventional measurements, which can be helpful if they are considered in PMU optimal placement. In this paper, a method is proposed for optimal placement of PMUs incorporating conventional measurements of zero injection buses and branch flow measurements using a permutation matrix. Furthermore, the effect of single branch outage and single PMU failure is included in the proposed method. When a branch with a flow measurement goes out, the network loses one observability path (the branch and one conventional measurement (the flow measurement. The permutation matrix proposed here is able to model the outage of a branch equipped with a flow measurement or connected to a zero injection bus. Also, measurement redundancy, and consequently measurement reliability, is enhanced without increasing the number of PMUs this implies a more efficient usage of PMUs than previous methods. The PMU placement problem is formulated as a mixed-integer linear programming that results in the global optimal solution. Results obtained from testing the proposed method on four well-known test systems in diverse situations confirm its efficiency.

  6. A Cross-Entropy-Based Admission Control Optimization Approach for Heterogeneous Virtual Machine Placement in Public Clouds

    Directory of Open Access Journals (Sweden)

    Li Pan

    2016-03-01

    Full Text Available Virtualization technologies make it possible for cloud providers to consolidate multiple IaaS provisions into a single server in the form of virtual machines (VMs. Additionally, in order to fulfill the divergent service requirements from multiple users, a cloud provider needs to offer several types of VM instances, which are associated with varying configurations and performance, as well as different prices. In such a heterogeneous virtual machine placement process, one significant problem faced by a cloud provider is how to optimally accept and place multiple VM service requests into its cloud data centers to achieve revenue maximization. To address this issue, in this paper, we first formulate such a revenue maximization problem during VM admission control as a multiple-dimensional knapsack problem, which is known to be NP-hard to solve. Then, we propose to use a cross-entropy-based optimization approach to address this revenue maximization problem, by obtaining a near-optimal eligible set for the provider to accept into its data centers, from the waiting VM service requests in the system. Finally, through extensive experiments and measurements in a simulated environment with the settings of VM instance classes derived from real-world cloud systems, we show that our proposed cross-entropy-based admission control optimization algorithm is efficient and effective in maximizing cloud providers’ revenue in a public cloud computing environment.

  7. Comparison of Sonography versus Digital Breast Tomosynthesis to Locate Intramammary Marker Clips.

    Science.gov (United States)

    Schulz-Wendtland, R; Dankerl, P; Dilbat, G; Bani, M; Fasching, P A; Heusinger, K; Lux, M P; Loehberg, C R; Jud, S M; Rauh, C; Bayer, C M; Beckmann, M W; Wachter, D L; Uder, M; Meier-Meitinger, M; Brehm, B

    2015-01-01

    Introduction: This study aimed to compare the accuracy of sonography versus digital breast tomosynthesis to locate intramammary marker clips placed under ultrasound guidance. Patients and Methods: Fifty patients with suspicion of breast cancer (lesion diameter less than 2 cm [cT1]) had ultrasound-guided core needle biopsy with placement of a marker clip in the center of the tumor. Intramammary marker clips were subsequently located with both sonography and digital breast tomosynthesis. Results: Sonography detected no dislocation of intrammammary marker clips in 42 of 50 patients (84 %); dislocation was reported in 8 patients (16 %) with a maximum dislocation of 7 mm along the x-, y- or z-axis. Digital breast tomosynthesis showed accurate placement without dislocation of the intramammary marker clip in 48 patients (96 %); 2 patients (4 %) had a maximum clip dislocation of 3 mm along the x-, y- or z-axis (p tomosynthesis could improve the accuracy when locating intramammary marker clips compared to sonography and could, in future, be used to complement or even completely replace sonography.

  8. Optimal sensor placement for large structures using the nearest neighbour index and a hybrid swarm intelligence algorithm

    International Nuclear Information System (INIS)

    Lian, Jijian; He, Longjun; Ma, Bin; Peng, Wenxiang; Li, Huokun

    2013-01-01

    Research on optimal sensor placement (OSP) has become very important due to the need to obtain effective testing results with limited testing resources in health monitoring. In this study, a new methodology is proposed to select the best sensor locations for large structures. First, a novel fitness function derived from the nearest neighbour index is proposed to overcome the drawbacks of the effective independence method for OSP for large structures. This method maximizes the contribution of each sensor to modal observability and simultaneously avoids the redundancy of information between the selected degrees of freedom. A hybrid algorithm combining the improved discrete particle swarm optimization (DPSO) with the clonal selection algorithm is then implemented to optimize the proposed fitness function effectively. Finally, the proposed method is applied to an arch dam for performance verification. The results show that the proposed hybrid swarm intelligence algorithm outperforms a genetic algorithm with decimal two-dimension array encoding and DPSO in the capability of global optimization. The new fitness function is advantageous in terms of sensor distribution and ensuring a well-conditioned information matrix and orthogonality of modes, indicating that this method may be used to provide guidance for OSP in various large structures. (paper)

  9. Optimizing placements of ground-based snow sensors for areal snow cover estimation using a machine-learning algorithm and melt-season snow-LiDAR data

    Science.gov (United States)

    Oroza, C.; Zheng, Z.; Glaser, S. D.; Bales, R. C.; Conklin, M. H.

    2016-12-01

    We present a structured, analytical approach to optimize ground-sensor placements based on time-series remotely sensed (LiDAR) data and machine-learning algorithms. We focused on catchments within the Merced and Tuolumne river basins, covered by the JPL Airborne Snow Observatory LiDAR program. First, we used a Gaussian mixture model to identify representative sensor locations in the space of independent variables for each catchment. Multiple independent variables that govern the distribution of snow depth were used, including elevation, slope, and aspect. Second, we used a Gaussian process to estimate the areal distribution of snow depth from the initial set of measurements. This is a covariance-based model that also estimates the areal distribution of model uncertainty based on the independent variable weights and autocorrelation. The uncertainty raster was used to strategically add sensors to minimize model uncertainty. We assessed the temporal accuracy of the method using LiDAR-derived snow-depth rasters collected in water-year 2014. In each area, optimal sensor placements were determined using the first available snow raster for the year. The accuracy in the remaining LiDAR surveys was compared to 100 configurations of sensors selected at random. We found the accuracy of the model from the proposed placements to be higher and more consistent in each remaining survey than the average random configuration. We found that a relatively small number of sensors can be used to accurately reproduce the spatial patterns of snow depth across the basins, when placed using spatial snow data. Our approach also simplifies sensor placement. At present, field surveys are required to identify representative locations for such networks, a process that is labor intensive and provides limited guarantees on the networks' representation of catchment independent variables.

  10. Integrated method to optimize well connection and platform placement on a multi-reservoir scenario

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Sergio Henrique Guerra de; Madeira, Marcelo Gomes; Franca, Martha Salles [Halliburton, Rio de Janeiro, RJ (Brazil); Mota, Rosane Oliveira; Silva, Edilon Ribeiro da; King, Vanessa Pereira Spear [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2012-07-01

    This paper describes a workflow created to optimize the platform placement and well-platform connections on a multi reservoir scenario using an integrated reservoir simulator paired with an optimization engine. The proposed methodology describes how a new platform, being incorporated into a pre-existing asset, can be better used to develop newly-discovered fields, while helping increase the production of existing fields by sharing their production load. The sharing of production facilities is highly important in Brazilian offshore assets because of their high price (a few billion dollars per facility) and the fact that total production is usually limited to the installed capacity of liquid processing, which is an important constraint on high water-cut well production rates typical to this region. The case study asset used to present the workflow consists of two deep water oil fields, each one developed by its own production platform, and a newly-discovered field with strong aquifer support that will be entirely developed with a new production platform. Because this new field should not include injector wells owing to the strong aquifer presence, the idea is to consider reconnecting existing wells from the two pre-existing fields to better use the production resources. In this scenario, the platform location is an important optimization issue, as a balance between supporting the production of the planned wells on the new field and the production of re-routed wells from the existing fields must be reached to achieve improved overall asset production. If the new platform is too far away from any interconnected production well, pressure-drop issues along the pipeline might actually decrease production from the existing fields rather than augment it. The main contribution of this work is giving the reader insights on how to model and optimize these complex decisions to generate high-quality scenarios. (author)

  11. PMU Placement Methods in Power Systems based on Evolutionary Algorithms and GPS Receiver

    Directory of Open Access Journals (Sweden)

    M. R. Mosavi

    2013-06-01

    Full Text Available In this paper, optimal placement of Phasor Measurement Unit (PMU using Global Positioning System (GPS is discussed. Ant Colony Optimization (ACO, Simulated Annealing (SA, Particle Swarm Optimization (PSO and Genetic Algorithm (GA are used for this problem. Pheromone evaporation coefficient and the probability of moving from state x to state y by ant are introduced into the ACO. The modified algorithm overcomes the ACO in obtaining global optimal solution and convergence speed, when applied to optimizing the PMU placement problem. We also compare this simulink with SA, PSO and GA that to find capability of ACO in the search of optimal solution. The fitness function includes observability, redundancy and number of PMU. Logarithmic Least Square Method (LLSM is used to calculate the weights of fitness function. The suggested optimization method is applied in 30-bus IEEE system and the simulation results show modified ACO find results better than PSO and SA, but same result with GA.

  12. Evaluation of soft-tissue artifacts when using anatomical and technical markers to measure mandibular motion

    Directory of Open Access Journals (Sweden)

    Chien-Chih Chen

    2011-06-01

    Conclusions: It appears that markers on the frontal nose bridge are good alternatives to transoral rigid devices for measuring mandibular motion, compared to optical frame markers and other skin markers on the face. The results of the current study will be helpful for establishing guidelines for marker placement when measuring mandibular movements in patients with potential temporomandibular disorders.

  13. Feasibility of magnetic marker localisation for non-palpable breast cancer.

    Science.gov (United States)

    Schermers, B; van der Hage, J A; Loo, C E; Vrancken Peeters, M T F D; Winter-Warnars, H A O; van Duijnhoven, F; Ten Haken, B; Muller, S H; Ruers, T J M

    2017-06-01

    Accurate tumour localisation is essential for breast-conserving surgery of non-palpable tumours. Current localisation technologies are associated with disadvantages such as logistical challenges and migration issues (wire guided localisation) or legislative complexities and high administrative burden (radioactive localisation). We present MAgnetic MArker LOCalisation (MaMaLoc), a novel technology that aims to overcome these disadvantages using a magnetic marker and a magnetic detection probe. This feasibility study reports on the first experience with this new technology for breast cancer localisation. Fifteen patients with unifocal, non-palpable breast cancer were recruited. They received concurrent placement of the magnetic marker in addition to a radioactive iodine seed, which is standard of care in our clinic. In a subset of five patients, migration of the magnetic marker was studied. During surgery, a magnetic probe and gammaprobe were alternately used to localise the markers and guide surgery. The primary outcome parameter was successful transcutaneous identification of the magnetic marker. Additionally, data on radiologist and surgeon satisfaction were collected. Magnetic marker placement was successful in all cases. Radiologists could easily adapt to the technology in the clinical workflow. Migration of the magnetic marker was negligible. The primary endpoint of the study was met with an identification rate of 100%. Both radiologists and surgeons reflected that the technology was intuitive to use and that it was comparable to radioactive iodine seed localisation. Magnetic marker localisation for non-palpable breast cancer is feasible and safe, and may be a viable non-radioactive alternative to current localisation technologies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Optimization of the tape placement process parameters for carbon–PPS composites

    NARCIS (Netherlands)

    Grouve, Wouter Johannes Bernardus; Warnet, Laurent; Rietman, B.; Visser, Roy; Akkerman, Remko

    2013-01-01

    The interrelation between process parameters, material properties and interlaminar bond strength is investigated for the laser assisted tape placement process. Unidirectionally carbon reinforced poly(phenylene sulfide) (PPS) tapes were welded onto carbon woven fabric reinforced PPS laminates. The

  15. Value-based distributed generator placements for service quality improvements

    Energy Technology Data Exchange (ETDEWEB)

    Teng, Jen-Hao; Chen, Chi-Fa [Department of Electrical Engineering, I-Shou University, No. 1, Section 1, Syuecheng Road, Dashu Township, Kaohsiung Country 840 (Taiwan); Liu, Yi-Hwa [Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei (Taiwan); Chen, Chia-Yen [Department of Computer Science, The University of Auckland (New Zealand)

    2007-03-15

    Distributed generator (DG) resources are small, self-contained electric generating plants that can provide power to homes, businesses or industrial facilities in distribution feeders. They can be used to reduce power loss and improve service reliability. However, the values of DGs are largely dependent on their types, sizes and locations as they were installed in distribution feeders. A value-based method is proposed in this paper to enhance the reliability and obtain the benefits for DG placement. The benefits of DG placement described in this paper include power cost saving, power loss reduction, and reliability enhancement. The costs of DG placement include the investment, maintenance and operating costs. The proposed value-based method tries to find the best tradeoff between the costs and benefits of DG placement and then find the optimal types of DG and their corresponding locations and sizes in distribution feeders. The derived formulations are solved by a genetic algorithm based method. Test results show that with proper types, sizes and installation site selection, DG placement can be used to improve system reliability, reduce customer interruption costs and save power cost; as well as enabling electric utilities to obtain the maximal economical benefits. (author)

  16. Evaluation of Effective Factors on Travel Time in Optimization of Bus Stops Placement Using Genetic Algorithm

    Science.gov (United States)

    Bargegol, Iraj; Ghorbanzadeh, Mahyar; Ghasedi, Meisam; Rastbod, Mohammad

    2017-10-01

    In congested cities, locating and proper designing of bus stops according to the unequal distribution of passengers is crucial issue economically and functionally, since this subject plays an important role in the use of bus system by passengers. Location of bus stops is a complicated subject; by reducing distances between stops, walking time decreases, but the total travel time may increase. In this paper, a specified corridor in the city of Rasht in north of Iran is studied. Firstly, a new formula is presented to calculate the travel time, by which the number of stops and consequently, the travel time can be optimized. An intended corridor with specified number of stops and distances between them is addressed, the related formulas to travel time are created, and its travel time is calculated. Then the corridor is modelled using a meta-heuristic method in order that the placement and the optimal distances of bus stops for that are determined. It was found that alighting and boarding time along with bus capacity are the most effective factors affecting travel time. Consequently, it is better to have more concentration on indicated factors for improving the efficiency of bus system.

  17. Keyword: Placement

    Science.gov (United States)

    Cassuto, Leonard

    2012-01-01

    The practical goal of graduate education is placement of graduates. But what does "placement" mean? Academics use the word without thinking much about it. "Placement" is a great keyword for the graduate-school enterprise. For one thing, its meaning certainly gives a purpose to graduate education. Furthermore, the word is a portal into the way of…

  18. A risk-based sensor placement methodology

    International Nuclear Information System (INIS)

    Lee, Ronald W.; Kulesz, James J.

    2008-01-01

    A risk-based sensor placement methodology is proposed to solve the problem of optimal location of sensors to protect population against the exposure to, and effects of, known and/or postulated chemical, biological, and/or radiological threats. Risk is calculated as a quantitative value representing population at risk from exposure at standard exposure levels. Historical meteorological data are used to characterize weather conditions as the frequency of wind speed and direction pairs. The meteorological data drive atmospheric transport and dispersion modeling of the threats, the results of which are used to calculate risk values. Sensor locations are determined via an iterative dynamic programming algorithm whereby threats detected by sensors placed in prior iterations are removed from consideration in subsequent iterations. In addition to the risk-based placement algorithm, the proposed methodology provides a quantification of the marginal utility of each additional sensor. This is the fraction of the total risk accounted for by placement of the sensor. Thus, the criteria for halting the iterative process can be the number of sensors available, a threshold marginal utility value, and/or a minimum cumulative utility achieved with all sensors

  19. Consumer Buying Behaviour; A Factor of Compulsive Buying Prejudiced by Windowsill Placement

    OpenAIRE

    Hameed, Irfan; Soomro, Yasir

    2012-01-01

    This empirical research investigates the impact of windowsill placement on the compulsive buying behavior of consumers on three different types of products i.e., convenience products, shopping products, and specialty products. Positive effect of windowsill placement on all three types of product categories has been hypothesized. The categorical regression (Optimal scaling) was used to test the hypotheses. The data was collected via self administered questionnaire from Pakistan through systema...

  20. Rise and Shock: Optimal Defibrillator Placement in a High-rise Building.

    Science.gov (United States)

    Chan, Timothy C Y

    2017-01-01

    Out-of-hospital cardiac arrests (OHCA) in high-rise buildings experience lower survival and longer delays until paramedic arrival. Use of publicly accessible automated external defibrillators (AED) can improve survival, but "vertical" placement has not been studied. We aim to determine whether elevator-based or lobby-based AED placement results in shorter vertical distance travelled ("response distance") to OHCAs in a high-rise building. We developed a model of a single-elevator, n-floor high-rise building. We calculated and compared the average distance from AED to floor of arrest for the two AED locations. We modeled OHCA occurrences using floor-specific Poisson processes, the risk of OHCA on the ground floor (λ 1 ) and the risk on any above-ground floor (λ). The elevator was modeled with an override function enabling direct travel to the target floor. The elevator location upon override was modeled as a discrete uniform random variable. Calculations used the laws of probability. Elevator-based AED placement had shorter average response distance if the number of floors (n) in the building exceeded three quarters of the ratio of ground-floor OHCA risk to above-ground floor risk (λ 1 /λ) plus one half (n ≥ 3λ 1 /4λ + 0.5). Otherwise, a lobby-based AED had shorter average response distance. If OHCA risk on each floor was equal, an elevator-based AED had shorter average response distance. Elevator-based AEDs travel less vertical distance to OHCAs in tall buildings or those with uniform vertical risk, while lobby-based AEDs travel less vertical distance in buildings with substantial lobby, underground, and nearby street-level traffic and OHCA risk.

  1. Optimal placement and decentralized robust vibration control for spacecraft smart solar panel structures

    International Nuclear Information System (INIS)

    Jiang, Jian-ping; Li, Dong-xu

    2010-01-01

    The decentralized robust vibration control with collocated piezoelectric actuator and strain sensor pairs is considered in this paper for spacecraft solar panel structures. Each actuator is driven individually by the output of the corresponding sensor so that only local feedback control is implemented, with each actuator, sensor and controller operating independently. Firstly, an optimal placement method for the location of the collocated piezoelectric actuator and strain gauge sensor pairs is developed based on the degree of observability and controllability indices for solar panel structures. Secondly, a decentralized robust H ∞ controller is designed to suppress the vibration induced by external disturbance. Finally, a numerical comparison between centralized and decentralized control systems is performed in order to investigate their effectiveness to suppress vibration of the smart solar panel. The simulation results show that the vibration can be significantly suppressed with permitted actuator voltages by the controllers. The decentralized control system almost has the same disturbance attenuation level as the centralized control system with a bit higher control voltages. More importantly, the decentralized controller composed of four three-order systems is a better practical implementation than a high-order centralized controller is

  2. Optimal placement of FACTS devices using optimization techniques: A review

    Science.gov (United States)

    Gaur, Dipesh; Mathew, Lini

    2018-03-01

    Modern power system is dealt with overloading problem especially transmission network which works on their maximum limit. Today’s power system network tends to become unstable and prone to collapse due to disturbances. Flexible AC Transmission system (FACTS) provides solution to problems like line overloading, voltage stability, losses, power flow etc. FACTS can play important role in improving static and dynamic performance of power system. FACTS devices need high initial investment. Therefore, FACTS location, type and their rating are vital and should be optimized to place in the network for maximum benefit. In this paper, different optimization methods like Particle Swarm Optimization (PSO), Genetic Algorithm (GA) etc. are discussed and compared for optimal location, type and rating of devices. FACTS devices such as Thyristor Controlled Series Compensator (TCSC), Static Var Compensator (SVC) and Static Synchronous Compensator (STATCOM) are considered here. Mentioned FACTS controllers effects on different IEEE bus network parameters like generation cost, active power loss, voltage stability etc. have been analyzed and compared among the devices.

  3. Optimal base station placement for wireless sensor networks with successive interference cancellation.

    Science.gov (United States)

    Shi, Lei; Zhang, Jianjun; Shi, Yi; Ding, Xu; Wei, Zhenchun

    2015-01-14

    We consider the base station placement problem for wireless sensor networks with successive interference cancellation (SIC) to improve throughput. We build a mathematical model for SIC. Although this model cannot be solved directly, it enables us to identify a necessary condition for SIC on distances from sensor nodes to the base station. Based on this relationship, we propose to divide the feasible region of the base station into small pieces and choose a point within each piece for base station placement. The point with the largest throughput is identified as the solution. The complexity of this algorithm is polynomial. Simulation results show that this algorithm can achieve about 25% improvement compared with the case that the base station is placed at the center of the network coverage area when using SIC.

  4. Analog integrated circuit design automation placement, routing and parasitic extraction techniques

    CERN Document Server

    Martins, Ricardo; Horta, Nuno

    2017-01-01

    This book introduces readers to a variety of tools for analog layout design automation. After discussing the placement and routing problem in electronic design automation (EDA), the authors overview a variety of automatic layout generation tools, as well as the most recent advances in analog layout-aware circuit sizing. The discussion includes different methods for automatic placement (a template-based Placer and an optimization-based Placer), a fully-automatic Router and an empirical-based Parasitic Extractor. The concepts and algorithms of all the modules are thoroughly described, enabling readers to reproduce the methodologies, improve the quality of their designs, or use them as starting point for a new tool. All the methods described are applied to practical examples for a 130nm design process, as well as placement and routing benchmark sets. Introduces readers to hierarchical combination of Pareto fronts of placements; Presents electromigration-aware routing with multilayer multiport terminal structures...

  5. Optimal needle placement for the accurate magnetic material quantification based on uncertainty analysis in the inverse approach

    International Nuclear Information System (INIS)

    Abdallh, A; Crevecoeur, G; Dupré, L

    2010-01-01

    The measured voltage signals picked up by the needle probe method can be interpreted by a numerical method so as to identify the magnetic material properties of the magnetic circuit of an electromagnetic device. However, when solving this electromagnetic inverse problem, the uncertainties in the numerical method give rise to recovery errors since the calculated needle signals in the forward problem are sensitive to these uncertainties. This paper proposes a stochastic Cramér–Rao bound method for determining the optimal sensor placement in the experimental setup. The numerical method is computationally time efficient where the geometrical parameters need to be provided. We apply the method for the non-destructive magnetic material characterization of an EI inductor where we ascertain the optimal experiment design. This design corresponds to the highest possible resolution that can be obtained when solving the inverse problem. Moreover, the presented results are validated by comparison with the exact material characteristics. The results show that the proposed methodology is independent of the values of the material parameter so that it can be applied before solving the inverse problem, i.e. as a priori estimation stage

  6. SAT, a flexible and optimized Web application for SSR marker development

    Directory of Open Access Journals (Sweden)

    Rami Jean-François

    2007-11-01

    Full Text Available Abstract Background Simple Sequence Repeats (SSRs, or microsatellites, are among the most powerful genetic markers known. A common method for the development of SSR markers is the construction of genomic DNA libraries enriched for SSR sequences, followed by DNA sequencing. However, designing optimal SSR markers from bulk sequence data is a laborious and time-consuming process. Results SAT (SSR Analysis Tool is a user-friendly Web application developed to minimize tedious manual operations and reduce errors. This tool facilitates the integration, analysis and display of sequence data from SSR-enriched libraries. SAT is designed to successively perform base calling and quality evaluation of chromatograms, eliminate cloning vector, adaptors and low quality sequences, detect chimera or partially digested sequences, search for SSR motifs, cluster and assemble the redundant sequences, and design SSR primer pairs. An additional virtual PCR step establishes primer specificity. Users may modify the different parameters of each step of the SAT analysis. Although certain steps are compulsory, such as SSR motifs search and sequence assembly, users do not have to run the entire pipeline, and they can choose selectively which steps to perform. A database allows users to store and query results, and to redo individual steps of the workflow. Conclusion The SAT Web application is available at http://sat.cirad.fr/sat, and a standalone command-line version is also freely downloadable. Users must send an email to the SAT administrator tropgene@cirad.fr to request a login and password.

  7. Injectable iodine-125 labeled tissue marker for radioactive localization of non-palpable breast lesions

    DEFF Research Database (Denmark)

    Schaarup-Jensen, Henrik; Jensen, Andreas Ingemann; Hansen, Anders Elias

    2018-01-01

    to be spatially well-defined and stable over a seven day period with excellent CT contrast (>1500 HU), enabling fluoroscopic visualization of markers during placement. The radioactivity remains strongly associated with the marker during the implantation period, which limits exposure to healthy tissue....... The surgical guidance marker is based on derivatives of the biomaterial sucrose acetate isobutyrate and unlike currently used markers it is injectable in the tissue using thin needles, reducing the discomfort to the patients significantly. The marker confers CT contrast and has radioactive properties, meaning...

  8. Virtual haptic system for intuitive planning of bone fixation plate placement

    Directory of Open Access Journals (Sweden)

    Kup-Sze Choi

    2017-01-01

    Full Text Available Placement of pre-contoured fixation plate is a common treatment for bone fracture. Fitting of fixation plates on fractured bone can be preoperatively planned and evaluated in 3D virtual environment using virtual reality technology. However, conventional systems usually employ 2D mouse and virtual trackball as the user interface, which makes the process inconvenient and inefficient. In the paper, a preoperative planning system equipped with 3D haptic user interface is proposed to allow users to manipulate the virtual fixation plate intuitively to determine the optimal position for placement on distal medial tibia. The system provides interactive feedback forces and visual guidance based on the geometric requirements. Creation of 3D models from medical imaging data, collision detection, dynamics simulation and haptic rendering are discussed. The system was evaluated by 22 subjects. Results show that the time to achieve optimal placement using the proposed system was shorter than that by using 2D mouse and virtual trackball, and the satisfaction rating was also higher. The system shows potential to facilitate the process of fitting fixation plates on fractured bones as well as interactive fixation plate design.

  9. Common ECG Lead Placement Errors. Part I: Limb Lead Reversals

    Directory of Open Access Journals (Sweden)

    Allison V. Rosen

    2015-10-01

    Full Text Available Background: Electrocardiography (ECG is a very useful diagnostic tool. However, errors in placement of ECG leads can create artifacts, mimic pathologies, and hinder proper ECG interpretation. It is important for members of the health care team to be able to recognize the common patterns resulting from lead placement errors. Methods: 12-lead ECGs were recorded in a single male healthy subject in his mid 20s. Six different limb lead reversals were compared to ECG recordings from correct lead placement. Results: Classic ECG patterns were observed when leads were reversed. Methods of discriminating these ECG patterns from true pathologic findings were described. Conclusion: Correct recording and interpretation of ECGs is key to providing optimal patient care. It is therefore crucial to be able to recognize common ECG patterns that are indicative of lead reversals.

  10. Patterning control strategies for minimum edge placement error in logic devices

    Science.gov (United States)

    Mulkens, Jan; Hanna, Michael; Slachter, Bram; Tel, Wim; Kubis, Michael; Maslow, Mark; Spence, Chris; Timoshkov, Vadim

    2017-03-01

    In this paper we discuss the edge placement error (EPE) for multi-patterning semiconductor manufacturing. In a multi-patterning scheme the creation of the final pattern is the result of a sequence of lithography and etching steps, and consequently the contour of the final pattern contains error sources of the different process steps. We describe the fidelity of the final pattern in terms of EPE, which is defined as the relative displacement of the edges of two features from their intended target position. We discuss our holistic patterning optimization approach to understand and minimize the EPE of the final pattern. As an experimental test vehicle we use the 7-nm logic device patterning process flow as developed by IMEC. This patterning process is based on Self-Aligned-Quadruple-Patterning (SAQP) using ArF lithography, combined with line cut exposures using EUV lithography. The computational metrology method to determine EPE is explained. It will be shown that ArF to EUV overlay, CDU from the individual process steps, and local CD and placement of the individual pattern features, are the important contributors. Based on the error budget, we developed an optimization strategy for each individual step and for the final pattern. Solutions include overlay and CD metrology based on angle resolved scatterometry, scanner actuator control to enable high order overlay corrections and computational lithography optimization to minimize imaging induced pattern placement errors of devices and metrology targets.

  11. Enabling High-performance Interactive Geoscience Data Analysis Through Data Placement and Movement Optimization

    Science.gov (United States)

    Zhu, F.; Yu, H.; Rilee, M. L.; Kuo, K. S.; Yu, L.; Pan, Y.; Jiang, H.

    2017-12-01

    Since the establishment of data archive centers and the standardization of file formats, scientists are required to search metadata catalogs for data needed and download the data files to their local machines to carry out data analysis. This approach has facilitated data discovery and access for decades, but it inevitably leads to data transfer from data archive centers to scientists' computers through low-bandwidth Internet connections. Data transfer becomes a major performance bottleneck in such an approach. Combined with generally constrained local compute/storage resources, they limit the extent of scientists' studies and deprive them of timely outcomes. Thus, this conventional approach is not scalable with respect to both the volume and variety of geoscience data. A much more viable solution is to couple analysis and storage systems to minimize data transfer. In our study, we compare loosely coupled approaches (exemplified by Spark and Hadoop) and tightly coupled approaches (exemplified by parallel distributed database management systems, e.g., SciDB). In particular, we investigate the optimization of data placement and movement to effectively tackle the variety challenge, and boost the popularization of parallelization to address the volume challenge. Our goal is to enable high-performance interactive analysis for a good portion of geoscience data analysis exercise. We show that tightly coupled approaches can concentrate data traffic between local storage systems and compute units, and thereby optimizing bandwidth utilization to achieve a better throughput. Based on our observations, we develop a geoscience data analysis system that tightly couples analysis engines with storages, which has direct access to the detailed map of data partition locations. Through an innovation data partitioning and distribution scheme, our system has demonstrated scalable and interactive performance in real-world geoscience data analysis applications.

  12. Short-Term Distribution System State Forecast Based on Optimal Synchrophasor Sensor Placement and Extreme Learning Machine

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Huaiguang; Zhang, Yingchen

    2016-11-14

    This paper proposes an approach for distribution system state forecasting, which aims to provide an accurate and high speed state forecasting with an optimal synchrophasor sensor placement (OSSP) based state estimator and an extreme learning machine (ELM) based forecaster. Specifically, considering the sensor installation cost and measurement error, an OSSP algorithm is proposed to reduce the number of synchrophasor sensor and keep the whole distribution system numerically and topologically observable. Then, the weighted least square (WLS) based system state estimator is used to produce the training data for the proposed forecaster. Traditionally, the artificial neural network (ANN) and support vector regression (SVR) are widely used in forecasting due to their nonlinear modeling capabilities. However, the ANN contains heavy computation load and the best parameters for SVR are difficult to obtain. In this paper, the ELM, which overcomes these drawbacks, is used to forecast the future system states with the historical system states. The proposed approach is effective and accurate based on the testing results.

  13. Optimal experimental design for placement of boreholes

    Science.gov (United States)

    Padalkina, Kateryna; Bücker, H. Martin; Seidler, Ralf; Rath, Volker; Marquart, Gabriele; Niederau, Jan; Herty, Michael

    2014-05-01

    Drilling for deep resources is an expensive endeavor. Among the many problems finding the optimal drilling location for boreholes is one of the challenging questions. We contribute to this discussion by using a simulation based assessment of possible future borehole locations. We study the problem of finding a new borehole location in a given geothermal reservoir in terms of a numerical optimization problem. In a geothermal reservoir the temporal and spatial distribution of temperature and hydraulic pressure may be simulated using the coupled differential equations for heat transport and mass and momentum conservation for Darcy flow. Within this model the permeability and thermal conductivity are dependent on the geological layers present in the subsurface model of the reservoir. In general, those values involve some uncertainty making it difficult to predict actual heat source in the ground. Within optimal experimental the question is which location and to which depth to drill the borehole in order to estimate conductivity and permeability with minimal uncertainty. We introduce a measure for computing the uncertainty based on simulations of the coupled differential equations. The measure is based on the Fisher information matrix of temperature data obtained through the simulations. We assume that the temperature data is available within the full borehole. A minimization of the measure representing the uncertainty in the unknown permeability and conductivity parameters is performed to determine the optimal borehole location. We present the theoretical framework as well as numerical results for several 2d subsurface models including up to six geological layers. Also, the effect of unknown layers on the introduced measure is studied. Finally, to obtain a more realistic estimate of optimal borehole locations, we couple the optimization to a cost model for deep drilling problems.

  14. The need for radio-opaque side markers on CT of the paranasal sinuses

    International Nuclear Information System (INIS)

    Nandi, R.; Luk, T.L.; Henson, J.

    2003-01-01

    AIM: To audit the presence of a radio-opaque 'side marker' routinely placed on the right side of the face of all patients undergoing computed tomography (CT) of the paranasal sinuses in our hospital and to audit awareness levels amongst ear, nose and throat (ENT) clinical and theatre staff regarding the 'marker'. MATERIALS AND METHODS: An audit of 100 CT studies of the paranasal sinuses was carried out with regard to the presence or absence of the marker. A further audit was conducted relating to the awareness amongst ENT clinical staff and theatre nurses regarding the marker. Re-audit of a second cohort of 100 sinus CT studies was carried out after implementing changes indicated by the first audit cycle. Awareness amongst staff concerned was similarly re-audited. RESULTS: In audit cycle I the side marker was positively identified in 85% of the CT examinations and were deemed absent in 15%. Of the clinical staff interviewed, only 30% were aware of the presence of the 'marker' and it's significance. In audit cycle II the 'side marker' was positively identified in 100% of the scans reviewed. Awareness of the presence of the 'marker' amongst clinical staff was found to be 90%. CONCLUSIONS: The routine placement of a radio-opaque side marker on the right zygoma of all patients undergoing CT of paranasal sinuses is a simple yet effective additional means of denoting the correct side whilst interpreting such images. This has important implications regarding surgery. The audit has shown an improvement in both the placement of the side marker as well as in awareness levels amongst staff involved to ensure best practice

  15. Automated Fiber Placement of PEEK/IM7 Composites with Film Interleaf Layers

    Science.gov (United States)

    Hulcher, A. Bruce; Banks, William I., III; Pipes, R. Byron; Tiwari, Surendra N.; Cano, Roberto J.; Johnston, Norman J.; Clinton, R. G., Jr. (Technical Monitor)

    2001-01-01

    The incorporation of thin discrete layers of resin between plies (interleafing) has been shown to improve fatigue and impact properties of structural composite materials. Furthermore, interleafing could be used to increase the barrier properties of composites used as structural materials for cryogenic propellant storage. In this work, robotic heated-head tape placement of PEEK/IM7 composites containing a PEEK polymer film interleaf was investigated. These experiments were carried out at the NASA Langley Research Center automated fiber placement facility. Using the robotic equipment, an optimal fabrication process was developed for the composite without the interleaf. Preliminary interleaf processing trials indicated that a two-stage process was necessary; the film had to be tacked to the partially-placed laminate then fully melted in a separate operation. Screening experiments determined the relative influence of the various robotic process variables on the peel strength of the film-composite interface. Optimization studies were performed in which peel specimens were fabricated at various compaction loads and roller temperatures at each of three film melt processing rates. The resulting data were fitted with quadratic response surfaces. Additional specimens were fabricated at placement parameters predicted by the response surface models to yield high peel strength in an attempt to gage the accuracy of the predicted response and assess the repeatability of the process. The overall results indicate that quality PEEK/lM7 laminates having film interleaves can be successfully and repeatability fabricated by heated head automated fiber placement.

  16. A Novel Marker Based Method to Teeth Alignment in MRI

    Science.gov (United States)

    Luukinen, Jean-Marc; Aalto, Daniel; Malinen, Jarmo; Niikuni, Naoko; Saunavaara, Jani; Jääsaari, Päivi; Ojalammi, Antti; Parkkola, Riitta; Soukka, Tero; Happonen, Risto-Pekka

    2018-04-01

    Magnetic resonance imaging (MRI) can precisely capture the anatomy of the vocal tract. However, the crowns of teeth are not visible in standard MRI scans. In this study, a marker-based teeth alignment method is presented and evaluated. Ten patients undergoing orthognathic surgery were enrolled. Supraglottal airways were imaged preoperatively using structural MRI. MRI visible markers were developed, and they were attached to maxillary teeth and corresponding locations on the dental casts. Repeated measurements of intermarker distances in MRI and in a replica model was compared using linear regression analysis. Dental cast MRI and corresponding caliper measurements did not differ significantly. In contrast, the marker locations in vivo differed somewhat from the dental cast measurements likely due to marker placement inaccuracies. The markers were clearly visible in MRI and allowed for dental models to be aligned to head and neck MRI scans.

  17. H{sub 2}/H{infinity} control of flexible structures through linear matrix inequalities with pole placement

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Jean C. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The objective of this work is to apply the H2/H{infinity} control technique using linear matrix inequalities and pole placement constraints to the flexible structures control problem. The H2/H{infinity}control is a technique to design a controller with mixed features of the H2 and H{infinity} control formulations, such as, optimal dynamical performance and robust performance. The Linear Matrix Inequalities allow formulating the problem as a convex optimization problem, and additional constraints can be included such as the pole placement. The pole placement requirement comes from the necessity of adjusting the transient response of the plant and ensuring a specific behavior in terms of speed and damping responses. The mathematical model used for this study is related to a flexible beam, with an applied disturbance and an actuator in different positions. The state-space matrices of the structure were obtained using the finite element method with the Euler-Bernoulli formulation of beams. The results showed that the pole placement constraints can improve the performance of the controller H2/H{infinity}. The Matlab was used for the computational implementation. (author)

  18. Radiologic placement of Hickman catheters

    International Nuclear Information System (INIS)

    Robertson, L.J.; Mauro, M.A.; Jaques, P.F.

    1988-01-01

    Hickman catheter inserter has previously been predominantly accomplished surgically by means of venous cutdown or percutaneous placement in the operating room. The authors describe their method and results for 55 consecutive percutaneous placements of Hickman catheters in the interventional radiology suite. Complication rates were comparable to those for surgical techniques. Radiologic placement resulted in increased convenience, decreased time and cost of insertion, and super fluoroscopic control of catheter placement and any special manipulations. Modern angiographic materials provide safer access to the subclavian vein than traditional methods. The authors conclude that radiologic placement of Hickman catheters offers significant advantages over traditional surgical placement

  19. PMU Placement Based on Heuristic Methods, when Solving the Problem of EPS State Estimation

    OpenAIRE

    I. N. Kolosok; E. S. Korkina; A. M. Glazunova

    2014-01-01

    Creation of satellite communication systems gave rise to a new generation of measurement equipment – Phasor Measurement Unit (PMU). Integrated into the measurement system WAMS, the PMU sensors provide a real picture of state of energy power system (EPS). The issues of PMU placement when solving the problem of EPS state estimation (SE) are discussed in many papers. PMU placement is a complex combinatorial problem, and there is not any analytical function to optimize its variables. Therefore,...

  20. Optimization of Phasor Measurement Unit (PMU Placement in Supervisory Control and Data Acquisition (SCADA-Based Power System for Better State-Estimation Performance

    Directory of Open Access Journals (Sweden)

    Mohammad Shoaib Shahriar

    2018-03-01

    Full Text Available Present-day power systems are mostly equipped with conventional meters and intended for the installation of highly accurate phasor measurement units (PMUs to ensure better protection, monitoring and control of the network. PMU is a deliberate choice due to its unique capacity in providing accurate phasor readings of bus voltages and currents. However, due to the high expense and a requirement for communication facilities, the installation of a limited number of PMUs in a network is common practice. This paper presents an optimal approach to selecting the locations of PMUs to be installed with the objective of ensuring maximum accuracy of the state estimation (SE. The optimization technique ensures that the critical locations of the system will be covered by PMU meters which lower the negative impact of bad data on state-estimation performance. One of the well-known intelligent optimization techniques, the genetic algorithm (GA, is used to search for the optimal set of PMUs. The proposed technique is compared with a heuristic approach of PMU placement. The weighted least square (WLS, with a modified Jacobian to deal with the phasor quantities, is used to compute the estimation accuracy. IEEE 30-bus and 118-bus systems are used to demonstrate the suggested technique.

  1. End-User Software for Efficient Sensor Placement in Jacketed Wine Tanks

    Directory of Open Access Journals (Sweden)

    Dominik Schmidt

    2018-06-01

    Full Text Available In food processing, temperature is a key parameter affecting product quality and energy consumption. The efficiency of temperature control depends on the data provided by sensors installed in the production device. In the wine industry, temperature sensor placement inside the tanks is usually predetermined by the tank manufacturers. Winemakers rely on these measurements and configure their temperature control accordingly, not knowing whether the monitored values really represent the wine’s bulk temperature. To address this problem, we developed an end-user software which 1. allows winemakers or tank manufacturers to identify optimal sensor locations for customizable tank geometries and 2. allows for comparisons between actual and optimal sensor placements. The analysis is based on numerical simulations of a user-defined cooling scenario. Case studies involving two different tanks showed good agreement between experimental data and simulations. Implemented based on the scientific Linux operating system gmlinux, the application solely relies on open-source software that is available free of charge.

  2. Preoperative Computed Tomography-Guided Percutaneous Hookwire Localization of Metallic Marker Clips in the Breast with a Radial Approach: Initial Experience

    Energy Technology Data Exchange (ETDEWEB)

    Uematsu, T.; Kasami, M.; Uchida, Y.; Sanuki, J.; Kimura, K.; Tanaka, K.; Takahashi, K. [Dept. of Diagnostic Radiology, Dept. of Pathology, and Dept. of Breast Surgery, Shizuoka Cancer Center Hospital, Naga-izumi, Shizuoka (Japan)

    2007-07-15

    Background: Hookwire localization is the current standard technique for radiological marking of nonpalpable breast lesions. Stereotactic directional vacuum-assisted breast biopsy (SVAB) is of sufficient sensitivity and specificity to replace surgical biopsy. Wire localization for metallic marker clips placed after SVAB is needed. Purpose: To describe a method for performing computed tomography (CT)-guided hookwire localization using a radial approach for metallic marker clips placed percutaneously after SVAB. Material and Methods: Nineteen women scheduled for SVAB with marker-clip placement, CT-guided wire localization of marker clips, and, eventually, surgical excision were prospectively entered into the study. CT-guided wire localization was performed with a radial approach, followed by placement of a localizing marker-clip surgical excision. Feasibility and reliability of the procedure and the incidence of complications were examined. Results: CT-guided wire localization surgical excision was successfully performed in all 19 women without any complications. The mean total procedure time was 15 min. The median distance on CT image from marker clip to hookwire was 2 mm (range 0-3 mm). Conclusion: CT-guided preoperative hookwire localization with a radial approach for marker clips after SVAB is technically feasible.

  3. Preoperative computed tomography-guided percutaneous hookwire localization of metallic marker clips in the breast with a radial approach: initial experience.

    Science.gov (United States)

    Uematsu, T; Kasami, M; Uchida, Y; Sanuki, J; Kimura, K; Tanaka, K; Takahashi, K

    2007-06-01

    Hookwire localization is the current standard technique for radiological marking of nonpalpable breast lesions. Stereotactic directional vacuum-assisted breast biopsy (SVAB) is of sufficient sensitivity and specificity to replace surgical biopsy. Wire localization for metallic marker clips placed after SVAB is needed. To describe a method for performing computed tomography (CT)-guided hookwire localization using a radial approach for metallic marker clips placed percutaneously after SVAB. Nineteen women scheduled for SVAB with marker-clip placement, CT-guided wire localization of marker clips, and, eventually, surgical excision were prospectively entered into the study. CT-guided wire localization was performed with a radial approach, followed by placement of a localizing marker-clip surgical excision. Feasibility and reliability of the procedure and the incidence of complications were examined. CT-guided wire localization surgical excision was successfully performed in all 19 women without any complications. The mean total procedure time was 15 min. The median distance on CT image from marker clip to hookwire was 2 mm (range 0-3 mm). CT-guided preoperative hookwire localization with a radial approach for marker clips after SVAB is technically feasible.

  4. Implementing data placement strategies for the CMS experiment based on a popularity model

    International Nuclear Information System (INIS)

    Barreiro Megino, F H; Cinquilli, M; Giordano, D; Karavakis, E; Girone, M; Magini, N; Mancinelli, V; Spiga, D

    2012-01-01

    During the first two years of data taking, the CMS experiment has collected over 20 PetaBytes of data and processed and analyzed it on the distributed, multi-tiered computing infrastructure on the WorldWide LHC Computing Grid. Given the increasing data volume that has to be stored and efficiently analyzed, it is a challenge for several LHC experiments to optimize and automate the data placement strategies in order to fully profit of the available network and storage resources and to facilitate daily computing operations. Building on previous experience acquired by ATLAS, we have developed the CMS Popularity Service that tracks file accesses and user activity on the grid and will serve as the foundation for the evolution of their data placement. A fully automated, popularity-based site-cleaning agent has been deployed in order to scan Tier-2 sites that are reaching their space quota and suggest obsolete, unused data that can be safely deleted without disrupting analysis activity. Future work will be to demonstrate dynamic data placement functionality based on this popularity service and integrate it in the data and workload management systems: as a consequence the pre-placement of data will be minimized and additional replication of hot datasets will be requested automatically. This paper will give an insight into the development, validation and production process and will analyze how the framework has influenced resource optimization and daily operations in CMS.

  5. Using Chemicals to Optimize Conformance Control in Fractured Reservoirs; TOPICAL

    International Nuclear Information System (INIS)

    Seright, Randall S.; Liang, Jenn-Tai; Schrader, Richard; Hagstrom II, John; Wang, Ying; Kumar, Ananad; Wavrik, Kathryn

    2001-01-01

    This report describes work performed during the third and final year of the project, Using Chemicals to Optimize Conformance Control in Fractured Reservoirs. This research project had three objectives. The first objective was to develop a capability to predict and optimize the ability of gels to reduce permeability to water more than that to oil or gas. The second objective was to develop procedures for optimizing blocking agent placement in wells where hydraulic fractures cause channeling problems. The third objective was to develop procedures to optimize blocking agent placement in naturally fractured reservoirs

  6. PI controller design of a wind turbine: evaluation of the pole-placement method and tuning using constrained optimization

    DEFF Research Database (Denmark)

    Mirzaei, Mahmood; Tibaldi, Carlo; Hansen, Morten Hartvig

    2016-01-01

    to automatically tune the wind turbine controller subject to robustness constraints. The properties of the system such as the maximum sensitivity and complementary sensitivity functions (Ms and Mt), along with some of the responses of the system, are used to investigate the controller performance and formulate...... the optimization problem. The cost function is the integral absolute error (IAE) of the rotational speed from a disturbance modeled as a step in wind speed. Linearized model of the DTU 10-MW reference wind turbine is obtained using HAWCStab2. Thereafter, the model is reduced with model order reduction. The trade......PI/PID controllers are the most common wind turbine controllers. Normally a first tuning is obtained using methods such as pole-placement or Ziegler-Nichols and then extensive aeroelastic simulations are used to obtain the best tuning in terms of regulation of the outputs and reduction of the loads...

  7. Ultrasonography as an ancillary method for the positioning of markers in equine motion analysis

    Directory of Open Access Journals (Sweden)

    Luanna Ferreira Fasanelo Gomes

    2014-08-01

    Full Text Available Kinematic motion analysis is based on the reconstruction of selected bony anatomical landmarks identified by surface markers. Anatomical landmarks generally do not correspond to points but rather to relatively large and curved areas and their identification by palpation is not easy. Precise placement of surface markers is even more difficult and there is great variability between operators. In this study 16 examiners were asked to identify the lateral border of the left ischial tuberosity in a horse using palpation and ultrasonography for placement of a corresponding skin surface marker. Images of each marking procedure were captured using two video cameras and processed using the DVideow videogrammetry. A custom-written Matlab code was used to determine the position of the respective vectors. The positions of the markers were then compared to assess inter-examiner variability and the precision of the methods employed using the Bartletttest and the paired t-test respectively. Ultrasonography significantly improved the location of the anatomical landmark by each examiner (p = 0.04 and reduced the variability in the position of the surface marker when compared to palpation (p = 0.0028. The variability of the calculated distances (mean ± SD was 2.89 ± 2.24 cm and 1.63 ± 0.98 cm using palpation and ultrasonography respectively. Ultrasound guidance reduced inter-examiner variability and allowed visualization of the corresponding bony anatomical landmark.

  8. Joint sensor placement and power rating selection in energy harvesting wireless sensor networks

    KAUST Repository

    Bushnaq, Osama M.; Al-Naffouri, Tareq Y.; Chepuri, Sundeep Prabhakar; Leus, Geert

    2017-01-01

    In this paper, the focus is on optimal sensor placement and power rating selection for parameter estimation in wireless sensor networks (WSNs). We take into account the amount of energy harvested by the sensing nodes, communication link quality

  9. Tubal risk markers for failure to place transcervical sterilization coils

    Science.gov (United States)

    Leyser-Whalen, Ophra; Rouhani, Mahta; Rahman, Mahbubur; Berenson, Abbey B

    2011-01-01

    Background There is a growing body of literature on placement rates of the Essure® procedure, yet prior studies have not attempted to identify tubal-associated risk factors for placement failures. The current study examines risk markers associated with the inability to deploy the Essure® coils into the tubal lumen using the new ESS305 design. Study Design We used electronic medical record data to assess risk markers associated with the inability to place the Essure coils in the tubal lumen using the new ESS305 design. A total of 310 attempted procedures between June 14, 2007, and April 29, 2011 were analyzed. Results There were 18 tubal failures (5.8%) out of the 310 attempted procedures. A history of a prior sexually transmitted infection (STI) was associated with tubal failure (OR 2.64, 95% confidence interval (CI) 1.01–6.90; p=.048). Conclusions We speculate that the observed association between a prior STI and an inability to place the coil was due to a past history of pelvic inflammatory disease. PMID:22036044

  10. Placement by thermodynamic simulated annealing

    International Nuclear Information System (INIS)

    Vicente, Juan de; Lanchares, Juan; Hermida, Roman

    2003-01-01

    Combinatorial optimization problems arise in different fields of science and engineering. There exist some general techniques coping with these problems such as simulated annealing (SA). In spite of SA success, it usually requires costly experimental studies in fine tuning the most suitable annealing schedule. In this Letter, the classical integrated circuit placement problem is faced by Thermodynamic Simulated Annealing (TSA). TSA provides a new annealing schedule derived from thermodynamic laws. Unlike SA, temperature in TSA is free to evolve and its value is continuously updated from the variation of state functions as the internal energy and entropy. Thereby, TSA achieves the high quality results of SA while providing interesting adaptive features

  11. Computer modeling for optimal placement of gloveboxes

    International Nuclear Information System (INIS)

    Hench, K.W.; Olivas, J.D.; Finch, P.R.

    1997-08-01

    Reduction of the nuclear weapons stockpile and the general downsizing of the nuclear weapons complex has presented challenges for Los Alamos. One is to design an optimized fabrication facility to manufacture nuclear weapon primary components (pits) in an environment of intense regulation and shrinking budgets. Historically, the location of gloveboxes in a processing area has been determined without benefit of industrial engineering studies to ascertain the optimal arrangement. The opportunity exists for substantial cost savings and increased process efficiency through careful study and optimization of the proposed layout by constructing a computer model of the fabrication process. This paper presents an integrative two- stage approach to modeling the casting operation for pit fabrication. The first stage uses a mathematical technique for the formulation of the facility layout problem; the solution procedure uses an evolutionary heuristic technique. The best solutions to the layout problem are used as input to the second stage - a computer simulation model that assesses the impact of competing layouts on operational performance. The focus of the simulation model is to determine the layout that minimizes personnel radiation exposures and nuclear material movement, and maximizes the utilization of capacity for finished units

  12. Computer modeling for optimal placement of gloveboxes

    Energy Technology Data Exchange (ETDEWEB)

    Hench, K.W.; Olivas, J.D. [Los Alamos National Lab., NM (United States); Finch, P.R. [New Mexico State Univ., Las Cruces, NM (United States)

    1997-08-01

    Reduction of the nuclear weapons stockpile and the general downsizing of the nuclear weapons complex has presented challenges for Los Alamos. One is to design an optimized fabrication facility to manufacture nuclear weapon primary components (pits) in an environment of intense regulation and shrinking budgets. Historically, the location of gloveboxes in a processing area has been determined without benefit of industrial engineering studies to ascertain the optimal arrangement. The opportunity exists for substantial cost savings and increased process efficiency through careful study and optimization of the proposed layout by constructing a computer model of the fabrication process. This paper presents an integrative two- stage approach to modeling the casting operation for pit fabrication. The first stage uses a mathematical technique for the formulation of the facility layout problem; the solution procedure uses an evolutionary heuristic technique. The best solutions to the layout problem are used as input to the second stage - a computer simulation model that assesses the impact of competing layouts on operational performance. The focus of the simulation model is to determine the layout that minimizes personnel radiation exposures and nuclear material movement, and maximizes the utilization of capacity for finished units.

  13. Optimal capacitor placement and sizing using combined fuzzy ...

    African Journals Online (AJOL)

    Then the sizing of the capacitors is modeled as an optimization problem and the objective function (loss minimization) is solved using Hybrid Particle Swarm Optimization (HPSO) technique. A case study with an IEEE 34 bus distribution feeder is presented to illustrate the applicability of the algorithm. A comparison is made ...

  14. Placement of acid spoil materials

    Energy Technology Data Exchange (ETDEWEB)

    Pionke, H B; Rogowski, A S

    1982-06-01

    Potentially there are several chemical and hydrologic problems associated with placement of acid spoil materials. The rationale for a deep placement well below the soil surface, and preferably below a water table, is to prevent or minimize oxidation of pyrite to sulfuric acid and associated salts by reducing the supply of oxygen. If, however, substantial sulfuric acid or associated salts are already contained within the spoil because of present or previous mining, handling and reclamation operations (or if large supplies of indigenous salts exist, placement below a water table) may actually increase the rate of acid and salt leaching. Specific placement of acid- and salt-containing spoil should be aimed at preventing contact with percolating water or rising water tables. We recommend placement based on chemical and physical spoil properties that may affect water percolation O/sub 2/ diffusion rates in the profile. Both the deeper placement of acid spoil and coarser particle size can substantially reduce the amount of acid drainage. Placement above the water table with emphasis on percolate control may be better for high sulfate spoils, while placement below the non-fluctuating water table may be better for pyritic spoils.

  15. Assessment of prostatic fiducial marker introduction: patient morbidity, staff satisfaction and improved treatment field placement

    International Nuclear Information System (INIS)

    Brown, Simon; Lehman, Margot; Ferrari-Anderson, Janet; Glyde, Alan; Burmeister, Elizabeth; Nicol, David

    2011-01-01

    Increased accuracy when using fiducial markers for prostate localisation is well documented. This project aimed to establish the improvement in accuracy when using gold markers for daily prostate localisation, to assess patient satisfaction and morbidity from the transrectal implantation of gold seed markers and establish staff attitudes towards the newly introduced processes. Twenty patients with prostate cancer had three gold seeds implanted into the base, apex and central zone of the prostate transrectally using ultrasound guidance. Surveys were conducted to assess staff and patient satisfaction with the process of gold seed localisation. The gold markers were used to localise the prostate on a daily basis using megavoltage electronic portal imaging. Measurements were taken to establish the increase in accuracy when using gold fiducial markers compared with using the surrounding bony anatomy. Inter-fraction motion (1 standard deviation (SD)) of the fiducial markers was 2.20, 4.28 and 4.27 mm in the LR, SI and AP directions, respectively. Intra-fraction prostate motion (1 SD) was measured as 0.8 mm LR, 1.1 mm SI and 2.0 mm AP. The patient survey showed that the insertion and associated side effects were acceptable, with 5% of patients stating that the seed insertion was worse than the prostate biopsy, and 23.1% of patients experienced short duration (1–2 days) haematuria. The staff survey showed that daily online image guidance was achievable without affecting patient throughput. Thirty percent of treatment staff believed that performing online daily localisation did not add any extra time to a standard treatment, and the remaining 70% thought that the added time was minimal (2–4 min). Gold fiducial markers are an accurate, reliable and tolerable method of daily prostate localisation.

  16. Wavelength converter placement for different RWA algorithms in wavelength-routed all-optical networks

    Science.gov (United States)

    Chu, Xiaowen; Li, Bo; Chlamtac, Imrich

    2002-07-01

    Sparse wavelength conversion and appropriate routing and wavelength assignment (RWA) algorithms are the two key factors in improving the blocking performance in wavelength-routed all-optical networks. It has been shown that the optimal placement of a limited number of wavelength converters in an arbitrary mesh network is an NP complete problem. There have been various heuristic algorithms proposed in the literature, in which most of them assume that a static routing and random wavelength assignment RWA algorithm is employed. However, the existing work shows that fixed-alternate routing and dynamic routing RWA algorithms can achieve much better blocking performance. Our study in this paper further demonstrates that the wavelength converter placement and RWA algorithms are closely related in the sense that a well designed wavelength converter placement mechanism for a particular RWA algorithm might not work well with a different RWA algorithm. Therefore, the wavelength converter placement and the RWA have to be considered jointly. The objective of this paper is to investigate the wavelength converter placement problem under fixed-alternate routing algorithm and least-loaded routing algorithm. Under the fixed-alternate routing algorithm, we propose a heuristic algorithm called Minimum Blocking Probability First (MBPF) algorithm for wavelength converter placement. Under the least-loaded routing algorithm, we propose a heuristic converter placement algorithm called Weighted Maximum Segment Length (WMSL) algorithm. The objective of the converter placement algorithm is to minimize the overall blocking probability. Extensive simulation studies have been carried out over three typical mesh networks, including the 14-node NSFNET, 19-node EON and 38-node CTNET. We observe that the proposed algorithms not only outperform existing wavelength converter placement algorithms by a large margin, but they also can achieve almost the same performance comparing with full wavelength

  17. Development of the Animal Management and Husbandry Online Placement Tool.

    Science.gov (United States)

    Bates, Lucy; Crowther, Emma; Bell, Catriona; Kinnison, Tierney; Baillie, Sarah

    2013-01-01

    The workplace provides veterinary students with opportunities to develop a range of skills, making workplace learning an important part of veterinary education in many countries. Good preparation for work placements is vital to maximize learning; to this end, our group has developed a series of three computer-aided learning (CAL) packages to support students. The third of this series is the Animal Management and Husbandry Online Placement Tool (AMH OPT). Students need a sound knowledge of animal husbandry and the ability to handle the common domestic species. However, teaching these skills at university is not always practical and requires considerable resources. In the UK, the Royal College of Veterinary Surgeons (RCVS) requires students to complete 12 weeks of pre-clinical animal management and husbandry work placements or extramural studies (EMS). The aims are for students to improve their animal handling skills and awareness of husbandry systems, develop communication skills, and understand their future clients' needs. The AMH OPT is divided into several sections: Preparation, What to Expect, Working with People, Professionalism, Tips, and Frequently Asked Questions. Three stakeholder groups (university EMS coordinators, placement providers, and students) were consulted initially to guide the content and design and later to evaluate previews. Feedback from stakeholders was used in an iterative design process, resulting in a program that aims to facilitate student preparation, optimize the learning opportunities, and improve the experience for both students and placement providers. The CAL is available online and is open-access worldwide to support students during veterinary school.

  18. A suite of microsatellite markers optimized for amplification of DNA from Addax (Addax nasomaculatus) blood preserved on FTA cards.

    Science.gov (United States)

    Heim, Brett C; Ivy, Jamie A; Latch, Emily K

    2012-01-01

    The addax (Addax nasomaculatus) is a critically endangered antelope that is currently maintained in zoos through regional, conservation breeding programs. As for many captive species, incomplete pedigree data currently impedes the ability of addax breeding programs to confidently manage the genetics of captive populations and to select appropriate animals for reintroduction. Molecular markers are often used to improve pedigree resolution, thereby improving the long-term effectiveness of genetic management. When developing a suite of molecular markers, it is important to consider the source of DNA, as the utility of markers may vary across DNA sources. In this study, we optimized a suite of microsatellite markers for use in genotyping captive addax blood samples collected on FTA cards. We amplified 66 microsatellite loci previously described in other Artiodactyls. Sixteen markers amplified a single product in addax, but only 5 of these were found to be polymorphic in a sample of 37 addax sampled from a captive herd at Fossil Rim Wildlife Center in the US. The suite of microsatellite markers developed in this study provides a new tool for the genetic management of captive addax, and demonstrates that FTA cards can be a useful means of sample storage, provided appropriate loci are used in downstream analyses. © 2011 Wiley Periodicals, Inc.

  19. Optimal Placing of Wind Turbines: Modelling the Uncertainty

    NARCIS (Netherlands)

    Leenman, T.S.; Phillipson, F.

    2015-01-01

    When looking at the optimal place to locate a wind turbine, trade-offs have to be made between local placement and spreading: transmission loss favours local placements and the correlation between the stochastic productions of wind turbines favours spreading. In this paper steps are described to

  20. Optimal Placing of Wind Turbines: Modelling the Uncertainty

    NARCIS (Netherlands)

    Leenman, T.S.; Phillipson, F.

    2014-01-01

    When looking at the optimal place to locate a wind turbine, trade-offs have to be made between local placement and spreading: transmission loss favours local placements and the correlation between the stochastic productions of wind turbines favours spreading. In this paper steps are described to

  1. Why good placements matter: Pre-placement and placement risk factors associated with mental health disorders in pre-school children in foster care.

    Science.gov (United States)

    Hillen, Thomas; Gafson, Leonie

    2015-07-01

    Pre-school children placed in local authority care show elevated rates of mental health disorders when compared to the general population. This study investigated risk factors for mental health disorders relating to the period prior to entering care and while in care. A representative sample of 43 children in care aged 0-72 months in an inner London borough underwent comprehensive multidimensional assessments. Presence of emotional, behavioural, attachment and adaptive disorders was ascertained. Exposure to two pre-placement risk factors and six placement risk factors was compared between children with and without a disorder. A total of 26 children (60.5%) had at least one mental health disorder. The two pre-placement risk factors, multiple types of maltreatment and entry into care after the age of 6 months, were both significantly associated with mental health disorders. The three placement risk factors of sudden placement moves, multiple placement moves and child-carer alienation showed a significant association with mental health disorders. There was a strong correlation between the number of risk factors and the number of co-morbid mental health disorders per child (r = .67, p school mental health. © The Author(s) 2014.

  2. Optimal sensor placement for control of a supersonic mixed-compression inlet with variable geometry

    Science.gov (United States)

    Moore, Kenneth Thomas

    A method of using fluid dynamics models for the generation of models that are useable for control design and analysis is investigated. The problem considered is the control of the normal shock location in the VDC inlet, which is a mixed-compression, supersonic, variable-geometry inlet of a jet engine. A quasi-one-dimensional set of fluid equations incorporating bleed and moving walls is developed. An object-oriented environment is developed for simulation of flow systems under closed-loop control. A public interface between the controller and fluid classes is defined. A linear model representing the dynamics of the VDC inlet is developed from the finite difference equations, and its eigenstructure is analyzed. The order of this model is reduced using the square root balanced model reduction method to produce a reduced-order linear model that is suitable for control design and analysis tasks. A modification to this method that improves the accuracy of the reduced-order linear model for the purpose of sensor placement is presented and analyzed. The reduced-order linear model is used to develop a sensor placement method that quantifies as a function of the sensor location the ability of a sensor to provide information on the variable of interest for control. This method is used to develop a sensor placement metric for the VDC inlet. The reduced-order linear model is also used to design a closed loop control system to control the shock position in the VDC inlet. The object-oriented simulation code is used to simulate the nonlinear fluid equations under closed-loop control.

  3. Sediment Placement Areas 2012

    Data.gov (United States)

    California Natural Resource Agency — Dredge material placement sites (DMPS), including active, inactive, proposed and historical placement sites. Dataset covers US Army Corps of Engineers San Francisco...

  4. Sediment Placement Areas 2012

    Data.gov (United States)

    California Department of Resources — Dredge material placement sites (DMPS), including active, inactive, proposed and historical placement sites. Dataset covers US Army Corps of Engineers San Francisco...

  5. Automated beam placement for breast radiotherapy using a support vector machine based algorithm

    International Nuclear Information System (INIS)

    Zhao Xuan; Kong, Dewen; Jozsef, Gabor; Chang, Jenghwa; Wong, Edward K.; Formenti, Silvia C.; Wang Yao

    2012-01-01

    Purpose: To develop an automated beam placement technique for whole breast radiotherapy using tangential beams. We seek to find optimal parameters for tangential beams to cover the whole ipsilateral breast (WB) and minimize the dose to the organs at risk (OARs). Methods: A support vector machine (SVM) based method is proposed to determine the optimal posterior plane of the tangential beams. Relative significances of including/avoiding the volumes of interests are incorporated into the cost function of the SVM. After finding the optimal 3-D plane that separates the whole breast (WB) and the included clinical target volumes (CTVs) from the OARs, the gantry angle, collimator angle, and posterior jaw size of the tangential beams are derived from the separating plane equation. Dosimetric measures of the treatment plans determined by the automated method are compared with those obtained by applying manual beam placement by the physicians. The method can be further extended to use multileaf collimator (MLC) blocking by optimizing posterior MLC positions. Results: The plans for 36 patients (23 prone- and 13 supine-treated) with left breast cancer were analyzed. Our algorithm reduced the volume of the heart that receives >500 cGy dose (V5) from 2.7 to 1.7 cm 3 (p = 0.058) on average and the volume of the ipsilateral lung that receives >1000 cGy dose (V10) from 55.2 to 40.7 cm 3 (p = 0.0013). The dose coverage as measured by volume receiving >95% of the prescription dose (V95%) of the WB without a 5 mm superficial layer decreases by only 0.74% (p = 0.0002) and the V95% for the tumor bed with 1.5 cm margin remains unchanged. Conclusions: This study has demonstrated the feasibility of using a SVM-based algorithm to determine optimal beam placement without a physician's intervention. The proposed method reduced the dose to OARs, especially for supine treated patients, without any relevant degradation of dose homogeneity and coverage in general.

  6. FPGA Dynamic Power Minimization through Placement and Routing Constraints

    Directory of Open Access Journals (Sweden)

    Deepak Agarwal

    2006-08-01

    Full Text Available Field-programmable gate arrays (FPGAs are pervasive in embedded systems requiring low-power utilization. A novel power optimization methodology for reducing the dynamic power consumed by the routing of FPGA circuits by modifying the constraints applied to existing commercial tool sets is presented. The power optimization techniques influence commercial FPGA Place and Route (PAR tools by translating power goals into standard throughput and placement-based constraints. The Low-Power Intelligent Tool Environment (LITE is presented, which was developed to support the experimentation of power models and power optimization algorithms. The generated constraints seek to implement one of four power optimization approaches: slack minimization, clock tree paring, N-terminal net colocation, and area minimization. In an experimental study, we optimize dynamic power of circuits mapped into 0.12 μm Xilinx Virtex-II FPGAs. Results show that several optimization algorithms can be combined on a single design, and power is reduced by up to 19.4%, with an average power savings of 10.2%.

  7. Optimization of Lightweight Axles for an Innovative Carving Skateboard Based on Carbon Fiber Placement

    Directory of Open Access Journals (Sweden)

    Marc Fleischmann

    2018-02-01

    Full Text Available In 2003, the BMW Group developed a longboard called “StreetCarver”. The idea behind this product was to bring the perfect carving feeling of surf- and snowboarding on the streets by increasing the maneuverability of classical skateboard trucks. The outcome was a chassis based on complex kinematics. The negative side effect was the StreetCarver’s exceptional high weight of almost 8 kg. The main reason for this heaviness was the choice of traditional metallic engineering materials. In this research, modern fiber reinforced composites were used to lower the chassis’ mass by up to 50% to reach the weight of a common longboard. To accomplish that goal, carbon fibers were placed along pre-simulated load paths of the structural components in a so-called Tailored- Fiber-Placement process. This technology allows an angle-independent single-roving placement and leads not only to the reduction of weight but also helps to save valuable fiber material by avoiding cutting waste.

  8. MVMO-based approach for optimal placement and tuning of ...

    African Journals Online (AJOL)

    bus (New England) test system. Numerical results include performance comparisons with other metaheuristic optimization techniques, namely, comprehensive learning particle swarm optimization (CLPSO), genetic algorithm with multi-parent ...

  9. Product Placement in Cartoons

    Directory of Open Access Journals (Sweden)

    Irena Oroz Štancl

    2014-06-01

    Full Text Available Product placement is a marketing approach for integrating products or services into selected media content. Studies have shown that the impact of advertising on children and youth are large, and that it can affect their preferences and attitudes. The aim of this article is to determine the existing level of product placement in cartoons that are broadcast on Croatian television stations. Content analysis of cartoons in a period of one month gave the following results: in 30% of cartoons product placement was found; most product placement were visual ads, in 89%, however, auditory product placement and plot connection was also found. Most ads were related to toys and it is significant that even 65% of cartoons are accompanied by a large amount of products available on the Croatian market. This is the result of two sales strategies: brand licensing (selling popular cartoon characters to toys, food or clothing companies and cartoon production based on existing line of toys with the sole aim of making their sales more effective.

  10. Boat boarding ladder placement

    Science.gov (United States)

    1998-04-01

    Presented in three volumes; 'Boat Boarding Ladder Placement,' which explores safety considerations including potential for human contact with a rotating propeller; 'Boat Handhold Placement,' which explores essential principles and methods of fall con...

  11. Optimal Placement Algorithms for Virtual Machines

    OpenAIRE

    Bellur, Umesh; Rao, Chetan S; SD, Madhu Kumar

    2010-01-01

    Cloud computing provides a computing platform for the users to meet their demands in an efficient, cost-effective way. Virtualization technologies are used in the clouds to aid the efficient usage of hardware. Virtual machines (VMs) are utilized to satisfy the user needs and are placed on physical machines (PMs) of the cloud for effective usage of hardware resources and electricity in the cloud. Optimizing the number of PMs used helps in cutting down the power consumption by a substantial amo...

  12. Optimization and audit of radiation dose during percutaneous transluminal coronary angioplasty

    International Nuclear Information System (INIS)

    Livingstone, Roshan S.; Timothy Peace, B.S.; Chandy, Sunil; Gorge, Paul V.; Pati, Purendra

    2007-01-01

    The percutaneous transluminal coronary angioplasty (PTCA) is one of the interventional procedures which impart high radiation doses to patients compared to the other cardiologic procedures. This study intends to audit and optimize radiation dose imparted to patients undergoing PTCA. Forty-four patients who underwent PTCA involving single or multiple stent placement guided under cardiovascular X-ray machine were included in the study. Radiation doses were measured using dose area product (DAP) meter for patients undergoing single and multiple stent placements during PTCA. A dose reduction of 27-47% was achieved using copper filters and optimal exposure parameters. The mean DAP values before optimization were 66.16 and 122.68 Gy cm 2 for single and multiple stent placement respectively. These values were 48.67 and 65.44 Gy cm 2 respectively after optimization. In the present scenario, due to the increase in the number of PTCAs performed and the associated risk from radiation, periodical audit of radiation doses for interventional procedures are recommended. (author)

  13. Product placement and its aplication in foreign film

    OpenAIRE

    Vaněk, Tomáš

    2010-01-01

    Marketing and commertial communication and position of product placement within it, legislature governing product placement and its aplication, history of product placement, forms of product placement, use of product placement within marketing campaign, aplication of product placement in movie Casino Royale.

  14. Placement Optimization of Wind Farm Based on Niche Genetic Algorithm%基于小生境遗传算法的风电场布局优化

    Institute of Scientific and Technical Information of China (English)

    田琳琳; 赵宁; 钟伟; 胡偶

    2011-01-01

    The placement of wind turbines in a wind farm is optimized based on niche genetic algorithm. Two simplified oncoming flow models of the unidirectional uniform wind and the non-uniform wind are considered with variable wind directions. In order to predict a more realistic power produced by the wind farm, the modified Jensen wake model is employed to investigate the behavior of wake interactions among the wind turbines. The niche genetic algorithm is used in optimization to minimize the cost of en-ergy (COE). In addition to optimal configurations, the results include number of turbines, total power output, objective functions and efficiency of output power for each configuration. Compared with earlier studies, the present work provides more improved results, and it is suitable for the optimization of the wind turbine placement in wind farms.%基于小生境遗传算法对风电场内风力机机组的布局进行优化.在优化过程中,考虑等风速同风向和变风速变风向两种简化的入流模式,采用修正的Jensen尾流模型模拟机组之间尾流的相互干扰效应,以单位发电量所消耗的成本最低为目标,使用小生境遗传算法优化风电场机组的排布.文中给出了优化后的风电场布局轮廓图、风电场机组台数、总发电量、目标函数值以及风电场的效率.通过与以前的相关研究对比分析,表明本文的方法取得了较优的结果,可为将来真实风场的风力机排布提供参考依据.

  15. 22 CFR 96.50 - Placement and post-placement monitoring until final adoption in incoming cases.

    Science.gov (United States)

    2010-04-01

    ... qualified escorts, if used, and, if possible, in the company of the prospective adoptive parent(s). (b) In... greater. (c) When a placement for adoption is in crisis in the post-placement phase, the agency or person... resolving the crisis and the placement is disrupted, the agency or person assuming custody of the child...

  16. A format for phylogenetic placements.

    Directory of Open Access Journals (Sweden)

    Frederick A Matsen

    Full Text Available We have developed a unified format for phylogenetic placements, that is, mappings of environmental sequence data (e.g., short reads into a phylogenetic tree. We are motivated to do so by the growing number of tools for computing and post-processing phylogenetic placements, and the lack of an established standard for storing them. The format is lightweight, versatile, extensible, and is based on the JSON format, which can be parsed by most modern programming languages. Our format is already implemented in several tools for computing and post-processing parsimony- and likelihood-based phylogenetic placements and has worked well in practice. We believe that establishing a standard format for analyzing read placements at this early stage will lead to a more efficient development of powerful and portable post-analysis tools for the growing applications of phylogenetic placement.

  17. A Monte-Carlo-Based Method for the Optimal Placement and Operation Scheduling of Sewer Mining Units in Urban Wastewater Networks

    Directory of Open Access Journals (Sweden)

    Eleftheria Psarrou

    2018-02-01

    Full Text Available Pressures on water resources, which have increased significantly nowadays mainly due to rapid urbanization, population growth and climate change impacts, necessitate the development of innovative wastewater treatment and reuse technologies. In this context, a mid-scale decentralized technology concerning wastewater reuse is that of sewer mining. It is based on extracting wastewater from a wastewater system, treating it on-site and producing recycled water applicable for non-potable uses. Despite the technology’s considerable benefits, several challenges hinder its implementation. Sewer mining disturbs biochemical processes inside sewers and affects hydrogen sulfide build-up, resulting in odor, corrosion and health-related problems. In this study, a tool for optimal sewer mining unit placement aiming to minimize hydrogen sulfide production is presented. The Monte-Carlo method coupled with the Environmental Protection Agency’s Storm Water Management Model (SWMM is used to conduct multiple simulations of the network. The network’s response when sewage is extracted from it is also examined. Additionally, the study deals with optimal pumping scheduling. The overall methodology is applied in a sewer network in Greece providing useful results. It can therefore assist in selecting appropriate locations for sewer mining implementation, with the focus on eliminating hydrogen sulfide-associated problems while simultaneously ensuring that higher water needs are satisfied.

  18. An Analysis of the Optimal Placement of Beacon in Bluetooth-INS Indoor Localization

    OpenAIRE

    Zhao, Xinyu; Ruan, Ling; Zhang, Ling; Long, Yi; Cheng, Fei

    2018-01-01

    The placement of Bluetooth beacon has immediate impact on the accuracy and stability of indoor positioning. Affected by the shelter of building and human, Bluetooth shows uncertain spatial transmission characteristics. Therefore, the scientific deployment of the beacon nodes is closely related to the indoor space environment. In the study of positioning technology using Bluetooth, some scholars have discussed the deployment of Bluetooth beacon in different scenarios. In the principle of avoid...

  19. Wiring economy and volume exclusion determine neuronal placement in the Drosophila brain.

    Science.gov (United States)

    Rivera-Alba, Marta; Vitaladevuni, Shiv N; Mishchenko, Yuriy; Mischenko, Yuriy; Lu, Zhiyuan; Takemura, Shin-Ya; Scheffer, Lou; Meinertzhagen, Ian A; Chklovskii, Dmitri B; de Polavieja, Gonzalo G

    2011-12-06

    Wiring economy has successfully explained the individual placement of neurons in simple nervous systems like that of Caenorhabditis elegans [1-3] and the locations of coarser structures like cortical areas in complex vertebrate brains [4]. However, it remains unclear whether wiring economy can explain the placement of individual neurons in brains larger than that of C. elegans. Indeed, given the greater number of neuronal interconnections in larger brains, simply minimizing the length of connections results in unrealistic configurations, with multiple neurons occupying the same position in space. Avoiding such configurations, or volume exclusion, repels neurons from each other, thus counteracting wiring economy. Here we test whether wiring economy together with volume exclusion can explain the placement of neurons in a module of the Drosophila melanogaster brain known as lamina cartridge [5-13]. We used newly developed techniques for semiautomated reconstruction from serial electron microscopy (EM) [14] to obtain the shapes of neurons, the location of synapses, and the resultant synaptic connectivity. We show that wiring length minimization and volume exclusion together can explain the structure of the lamina microcircuit. Therefore, even in brains larger than that of C. elegans, at least for some circuits, optimization can play an important role in individual neuron placement. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Optimal PMU location in power systems using MICA

    Directory of Open Access Journals (Sweden)

    Seyed Abbas Taher

    2016-03-01

    Full Text Available This study presented a modified imperialist competitive algorithm (MICA for optimal placement of phasor measurement units (PMUs in normal and contingency conditions of power systems. The optimal PMU placement problem is used for full network observability with the minimum number of PMUs. For this purpose, PMUs are installed in strategic buses. Efficiency of the proposed method is shown by the simulation results of IEEE 14, 30, 57, and 118-bus test systems. Results of the numerical simulation on IEEE-test systems indicated that the proposed technique provided maximum redundancy measurement and minimum request of PMUs so that the whole system could be topologically observable by installing PMUs on the minimum system buses. To verify the proposed method, the results are compared with those of some recently reported methods. When MICA is used for solving optimal PMU placement (OPP, the number of PMUs would be usually equal to or less than those of the other existing methods. Results indicated that MICA is a very fast and accurate algorithm for OPP solution.

  1. ESL Placement and Schools

    Science.gov (United States)

    Callahan, Rebecca; Wilkinson, Lindsey; Muller, Chandra; Frisco, Michelle

    2010-01-01

    In this study, the authors explore English as a Second Language (ESL) placement as a measure of how schools label and process immigrant students. Using propensity score matching and data from the Adolescent Health and Academic Achievement Study and the National Longitudinal Study of Adolescent Health, the authors estimate the effect of ESL placement on immigrant achievement. In schools with more immigrant students, the authors find that ESL placement results in higher levels of academic performance; in schools with few immigrant students, the effect reverses. This is not to suggest a one-size-fits-all policy; many immigrant students, regardless of school composition, generational status, or ESL placement, struggle to achieve at levels sufficient for acceptance to a 4-year university. This study offers several factors to be taken into consideration as schools develop policies and practices to provide immigrant students opportunities to learn. PMID:20617111

  2. Preoperative short hookwire placement for small pulmonary lesions: evaluation of technical success and risk factors for initial placement failure.

    Science.gov (United States)

    Iguchi, Toshihiro; Hiraki, Takao; Matsui, Yusuke; Fujiwara, Hiroyasu; Masaoka, Yoshihisa; Tanaka, Takashi; Sato, Takuya; Gobara, Hideo; Toyooka, Shinichi; Kanazawa, Susumu

    2018-05-01

    To retrospectively evaluate the technical success of computed tomography fluoroscopy-guided short hookwire placement before video-assisted thoracoscopic surgery and to identify the risk factors for initial placement failure. In total, 401 short hookwire placements for 401 lesions (mean diameter 9.3 mm) were reviewed. Technical success was defined as correct positioning of the hookwire. Possible risk factors for initial placement failure (i.e., requirement for placement of an additional hookwire or to abort the attempt) were evaluated using logistic regression analysis for all procedures, and for procedures performed via the conventional route separately. Of the 401 initial placements, 383 were successful and 18 failed. Short hookwires were finally placed for 399 of 401 lesions (99.5%). Univariate logistic regression analyses revealed that in all 401 procedures only the transfissural approach was a significant independent predictor of initial placement failure (odds ratio, OR, 15.326; 95% confidence interval, CI, 5.429-43.267; p < 0.001) and for the 374 procedures performed via the conventional route only lesion size was a significant independent predictor of failure (OR 0.793, 95% CI 0.631-0.996; p = 0.046). The technical success of preoperative short hookwire placement was extremely high. The transfissural approach was a predictor initial placement failure for all procedures and small lesion size was a predictor of initial placement failure for procedures performed via the conventional route. • Technical success of preoperative short hookwire placement was extremely high. • The transfissural approach was a significant independent predictor of initial placement failure for all procedures. • Small lesion size was a significant independent predictor of initial placement failure for procedures performed via the conventional route.

  3. Theoretical modeling for optimizing horizontal production well placement in thermal recovery environments to maximize recovery

    Energy Technology Data Exchange (ETDEWEB)

    Bourgeois, D.J. [Schlumberger Canada Ltd., Calgary, AB (Canada)

    2008-07-01

    Heavy oil has a high viscosity and a low API gravity rating. Since it is difficult to get a fluid of this nature to flow, enhanced oil recovery techniques are required to extract the oil from the reservoir. Thermal recovery strategies such as steam assisted gravity drainage (SAGD) and cyclic steam injection stimulation (CSS) can be used. These techniques involve injecting steam into a formation which heats up the fluid in place decreasing its viscosity and allowing it to flow into the producing well bore. In order to maximize hydrocarbon recovery from this type of geological environment, the placement of the horizontal production well bore relative to the base of the reservoir is important. In conventional oil and gas plays, well placement methods involving directional deep resistivity logging while drilling (DDR-LWD) measurements to map formation contacts while drilling have enabled wells to be placed relative to formation boundaries. This paper discussed a study that presented some theoretical resistivity inversion and forward modeling results generated from a three-dimensional geocellular model to confirm that this evolving DDR-LWD technology may be applicable to western Canada's Athabasca heavy oil drilling environments. The paper discussed the effect of well bore position, thermal recovery, and pro-active well placement. Resistivity modeling work flow was also presented. It was concluded that being able to drill a horizontal production well relative to the base of the formation could help minimize abandoned oil ultimately leading to better recovery. 4 refs., 8 figs.

  4. Sensor Placement For Structural Monitoring of Transmission Line Towers

    Directory of Open Access Journals (Sweden)

    Benny eRaphael

    2015-11-01

    Full Text Available Transmission line towers are usually analyzed using linear elastic idealized truss models. Due to the assumptions used in the analysis, there are discrepancies between the actual results obtained from full scale prototype testing and the analytical results. Therefore, design engineers are interested in assessing the actual stress levels in transmission line towers. Since it is costly to place sensors on every member of a tower structure, the best locations for sensors need to be carefully selected. This study evaluates a methodology for sensor placement in transmission line towers. The objective is to find optimal locations for sensors such that the real behavior of the structure can be explained from measurements. The methodology is based on the concepts of entropy and model falsification. Sensor locations are selected based on maximum entropy such that there is maximum separation between model instances that represent different possible combinations of parameter values which have uncertainties. The performance of the proposed algorithm is compared to that of an intuitive method in which sensor locations are selected where the forces are maximum. A typical 220 kV transmission tower is taken as case study in this paper. It is shown that the intuitive method results in much higher number of non-separable models compared to the optimal sensor placement algorithm. Thus the intuitive method results in poor identification of the system.

  5. Current opinion on clip placement after breast biopsy: A survey of practising radiologists in France and Quebec

    International Nuclear Information System (INIS)

    Thomassin-Naggara, I.; Jalaguier-Coudray, A.; Chopier, J.; Tardivon, A.; Trop, I.

    2013-01-01

    Aim: To investigate current practice regarding clip placement after breast biopsy. Materials and methods: In June 2011, an online survey instrument was designed using an Internet-based survey site ( (www.surveymonkey.com)) to assess practices and opinions of breast radiologists regarding clip placement after breast biopsy. Radiologists were asked to give personal practice data, describe their current practice regarding clip deployment under stereotactic, ultrasonographic, and magnetic resonance imaging (MRI) guidance, and describe what steps are taken to ensure quality control with regards to clip deployment. Results: The response rate was 29.9% in France (131 respondents) and 46.7% in Quebec (50 respondents). The great majority of respondents used breast markers in their practice (92.1% in France and 96% in Quebec). In both countries, most reported deploying a clip after percutaneous biopsy under stereotactic or MRI guidance. Regarding clip deployment under ultrasonography, 38% of Quebec radiologists systematically placed a marker after each biopsy, whereas 30% of French radiologists never placed a marker in this situation, mainly due to its cost. Finally, 56.4% of radiologists in France and 54% in Quebec considered that their practice regarding clip deployment after breast percutaneous biopsy had changed in the last 5 years. Conclusion: There continues to be variations in the use of biopsy clips after imaging-guided biopsies, particularly with regards to sonographic techniques. These variations are likely to decrease over time, with the standardization of relatively new investigation protocols

  6. Evaluation of sensor placement algorithms for on-orbit identification of space platforms

    Science.gov (United States)

    Glassburn, Robin S.; Smith, Suzanne Weaver

    1994-01-01

    Anticipating the construction of the international space station, on-orbit modal identification of space platforms through optimally placed accelerometers is an area of recent activity. Unwanted vibrations in the platform could affect the results of experiments which are planned. Therefore, it is important that sensors (accelerometers) be strategically placed to identify the amount and extent of these unwanted vibrations, and to validate the mathematical models used to predict the loads and dynamic response. Due to cost, installation, and data management issues, only a limited number of sensors will be available for placement. This work evaluates and compares four representative sensor placement algorithms for modal identification. Most of the sensor placement work to date has employed only numerical simulations for comparison. This work uses experimental data from a fully-instrumented truss structure which was one of a series of structures designed for research in dynamic scale model ground testing of large space structures at NASA Langley Research Center. Results from this comparison show that for this cantilevered structure, the algorithm based on Guyan reduction is rated slightly better than that based on Effective Independence.

  7. Energy efficient sensor nodes placement using Territorial Predator Scent Marking Algorithm (TPSMA)

    International Nuclear Information System (INIS)

    Abidin, H Z; Din, N M

    2013-01-01

    The positions of sensor nodes in a Wireless Sensor Network (WSN) must be able to provide maximum coverage with a longer lifetime. This paper proposed a sensor node placement technique that utilizes a new biologically inspired optimization technique that imitates the behavior of territorial predators in marking their territories with their odors known as Territorial Predator Scent Marking Algorithm (TPSMA). The TPSMA deployed in this paper uses the maximum coverage ratio as the objective function. The performance of the proposed technique is then compared with other schemes in terms of uniformity and average energy consumption. Simulation results show that the WSN deployed with the proposed sensor node placement scheme consumes lower energy compared to the other two schemes and is expected to provide longer lifetime.

  8. Altered Passive Eruption Complicating Optimal Orthodontic Bracket Placement: A Case Report and Review of Literature.

    Science.gov (United States)

    Pulgaonkar, Rohan; Chitra, Prasad

    2015-11-01

    An unusual case of altered passive eruption with gingival hyperpigmentation and a Class I malocclusion in a 12-year-old girl having no previous history of medication is presented. The patient reported with spacing in the upper arch, moderate crowding in the lower arch, anterior crossbite and excessive gingival tissue on the labial surfaces of teeth in both the arches. The inadequate crown lengths made placement of the orthodontic brackets difficult. Preadjusted orthodontic brackets have a very precise placement protocol which can affect tooth movement in all 3 planes of space if violated. The periodontal condition was diagnosed as altered passive eruption Type IA. Interdisciplinary treatment protocols including periodontal surgical and orthodontic procedures were used. The periodontal surgical procedures were carried out prior to orthodontic therapy and the results obtained were satisfactory. It is suggested that orthodontists should be aware of conditions like altered passive eruption and modalities of management. In most instances, orthodontic therapy is not hindered.

  9. A Class-Specific Optimizing Compiler

    Directory of Open Access Journals (Sweden)

    Michael D. Sharp

    1993-01-01

    Full Text Available Class-specific optimizations are compiler optimizations specified by the class implementor to the compiler. They allow the compiler to take advantage of the semantics of the particular class so as to produce better code. Optimizations of interest include the strength reduction of class:: array address calculations, elimination of large temporaries, and the placement of asynchronous send/recv calls so as to achieve computation/communication overlap. We will outline our progress towards the implementation of a C++ compiler capable of incorporating class-specific optimizations.

  10. Material quality development during the automated tow placement process

    Science.gov (United States)

    Tierney, John Joseph

    Automated tow placement (ATP) of thermoplastic composites builds on the existing industrial base for equipment, robotics and kinematic placement of material with the aim of further cost reduction by eliminating the autoclave entirely. During ATP processing, thermoplastic composite tows are deposited on a preconsolidated substrate at rates ranging from 10--100mm/s and consolidated using the localized application of heat and pressure by a tow placement head mounted on a robot. The process is highly non-isothermal subjecting the material to multiple heating and cooling rates approaching 1000°C/sec. The requirement for the ATP process is to achieve the same quality in seconds (low void content, full translation of mechanical properties and degree of bonding and minimal warpage) as the autoclave process achieves in hours. The scientific challenge was to first understand and then model the relationships between processing, material response, microstructure and quality. The important phenomena affecting quality investigated in this study include a steady state heat transfer simulation, consolidation and deconsolidation (void dynamics), intimate contact and polymer interdiffusion (degree of bonding/mechanical properties) and residual stress and warpage (crystallization and viscoelastic response). A fundamental understanding of the role of materials related to these mechanisms and their relationship to final quality is developed and applied towards a method of process control and optimization.

  11. Immediate placement of dental implants in the esthetic zone : a systematic review and pooled analysis

    NARCIS (Netherlands)

    Slagter, Kirsten W; den Hartog, Laurens; Bakker, Nicolaas A; Vissink, Arjan; Meijer, Henny J A; Raghoebar, Gerry M

    Background: Research interest on immediate placement of dental implants has shifted from implant survival toward optimal preservation of soft and hard tissues. The aim of this study is to systematically assess the condition of implant survival, peri-implant hard and soft tissue changes, esthetic

  12. Humanitarian engineering placements in our own communities

    Science.gov (United States)

    VanderSteen, J. D. J.; Hall, K. R.; Baillie, C. A.

    2010-05-01

    There is an increasing interest in the humanitarian engineering curriculum, and a service-learning placement could be an important component of such a curriculum. International placements offer some important pedagogical advantages, but also have some practical and ethical limitations. Local community-based placements have the potential to be transformative for both the student and the community, although this potential is not always seen. In order to investigate the role of local placements, qualitative research interviews were conducted. Thirty-two semi-structured research interviews were conducted and analysed, resulting in a distinct outcome space. It is concluded that local humanitarian engineering placements greatly complement international placements and are strongly recommended if international placements are conducted. More importantly it is seen that we are better suited to address the marginalised in our own community, although it is often easier to see the needs of an outside populace.

  13. Optimization in multi-implant placement for immediate loading in edentulous arches using a modified surgical template and prototyping: a case report.

    Science.gov (United States)

    Jayme, Sérgio J; Muglia, Valdir A; de Oliveira, Rafael R; Novaes, Arthur B Júnior

    2008-01-01

    Immediate loading of dental implants shortens the treatment time and makes it possible to give the patient an esthetic appearance throughout the treatment period. Placement of dental implants requires precise planning that accounts for anatomic limitations and restorative goals. Diagnosis can be made with the assistance of computerized tomographic scanning, but transfer of planning to the surgical field is limited. Recently, novel CAD/CAM techniques such as stereolithographic rapid prototyping have been developed to build surgical guides in an attempt to improve precision of implant placement. The aim of this case report was to show a modified surgical template used throughout implant placement as an alternative to a conventional surgical guide.

  14. Does the insertion of a gel-based marker at stereotactic breast biopsy allow subsequent wire localizations to be carried out under ultrasound guidance?

    International Nuclear Information System (INIS)

    McMahon, M.A.; James, J.J.; Cornford, E.J.; Hamilton, L.J.; Burrell, H.C.

    2011-01-01

    Aim: To investigate whether the insertion of a gel-based marker at the time of stereotactic breast biopsy allows subsequent preoperative localization to be performed under ultrasound guidance. Materials and methods: One hundred consecutive women who underwent either a 10 G stereotactic vacuum-assisted breast biopsy or 14 G stereotactic core biopsy with marker placement, followed by wire localization and surgical excision were identified. All had mammographic abnormalities not initially visible with ultrasound. The method of preoperative localization was recorded and its success judged with reference to the wire position on the post-procedure films relative to the mammographic abnormality and the marker. Histopathology data were reviewed to ensure the lesion had been adequately excised. Results: Eighty-three women (83%) had a successful ultrasound-guided wire localization. Successful ultrasound-guided localization was more likely after stereotactic vacuum biopsy (86%) compared to stereotactic core biopsy (68%), although this did not quite reach statistical significance (p = 0.06). Conclusion: The routine placement of a gel-based marker after stereotactic breast biopsy facilitates preoperative ultrasound-guided localization.

  15. Control, Co-generation, and Sensor Placement Strategy for Integral Small Modular Reactors

    International Nuclear Information System (INIS)

    Upadhyaya, Belle-R.; Fan, Li; Hines, J.-Wesley; Perillo, Sergio-R. P.

    2011-01-01

    , the monitoring of process units and fault diagnosis is of high importance for the safe and optimal operation of a coupled nuclear desalination plant. An efficient sensor placement strategy will help in the quick and accurate identification of faults in sensors, field devices, and the processes of a large industrial plant, such as a nuclear desalination system. A dynamic model of a MSF desalination plant was developed and interfaced with graph-based techniques in order to optimize sensor placement, based on the minimization of fault unobervability. The application of the proposed FDI approach, with optimal sensor placement strategy, is demonstrated for the nuclear desalination system

  16. Control, Co-generation, and Sensor Placement Strategy for Integral Small Modular Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyaya, Belle-R.; Fan, Li; Hines, J.-Wesley [University of Tennessee, Knoxville (United States); Perillo, Sergio-R. P. [Instituto de Pesquisas Energeticas e Nucleares, Sao Paulo (Brazil)

    2011-08-15

    issues, the monitoring of process units and fault diagnosis is of high importance for the safe and optimal operation of a coupled nuclear desalination plant. An efficient sensor placement strategy will help in the quick and accurate identification of faults in sensors, field devices, and the processes of a large industrial plant, such as a nuclear desalination system. A dynamic model of a MSF desalination plant was developed and interfaced with graph-based techniques in order to optimize sensor placement, based on the minimization of fault unobervability. The application of the proposed FDI approach, with optimal sensor placement strategy, is demonstrated for the nuclear desalination system.

  17. Diagnostic markers of infection in curret pediatric practice | Chiabia ...

    African Journals Online (AJOL)

    chemokines, cytokines, adhesion molecules, cell surface markers and polymerase chain reaction are expensive and available only in specialised research laboratories. Optimal benefit can be obtained from rational use of currently available markers either by multiple marker assays or serial measurements which increase ...

  18. Optimization of Moving Coil Actuators for Digital Displacement Machines

    DEFF Research Database (Denmark)

    Nørgård, Christian; Bech, Michael Møller; Roemer, Daniel Beck

    2016-01-01

    This paper focuses on deriving an optimal moving coil actuator design, used as force pro-ducing element in hydraulic on/off valves for Digital Displacement machines. Different moving coil actuator geometry topologies (permanent magnet placement and magnetiza-tion direction) are optimized for actu......This paper focuses on deriving an optimal moving coil actuator design, used as force pro-ducing element in hydraulic on/off valves for Digital Displacement machines. Different moving coil actuator geometry topologies (permanent magnet placement and magnetiza-tion direction) are optimized...... for actuating annular seat valves in a digital displacement machine. The optimization objectives are to the minimize the actuator power, the valve flow losses and the height of the actuator. Evaluation of the objective function involves static finite element simulation and simulation of an entire operation...... designs requires approximately 20 W on average and may be realized in 20 mm × Ø 22.5 mm (height × diameter) for a 20 kW pressure chamber. The optimization is carried out using the multi-objective Generalized Differential Evolu-tion optimization algorithm GDE3 which successfully handles constrained multi-objective...

  19. Spatiotemporal AED Location Optimization

    NARCIS (Netherlands)

    Chan, Timothy C.Y.; Sun, Christopher L.F.; Demirtas, Derya; Morrison, Laurie J.; Brooks, Steven C.

    2015-01-01

    Background: Mathematical optimization can be used to plan future AED placement to maximize out-of-hospital cardiac arrest (OHCA) coverage. Many public access AEDs are placed in locations without 24/7 access. AED coverage can be overestimated unless temporal availability is considered. Objective: To

  20. Placement suitability criteria of composite tape for mould surface in automated tape placement

    Directory of Open Access Journals (Sweden)

    Zhang Peng

    2015-10-01

    Full Text Available Automated tape placement is an important automated process used for fabrication of large composite structures in aeronautical industry. The carbon fiber composite parts realized with this process tend to replace the aluminum parts produced by high-speed machining. It is difficult to determine the appropriate width of the composite tape in automated tape placement. Wrinkling will appear in the tape if it does not suit for the mould surface. Thus, this paper deals with establishing placement suitability criteria of the composite tape for the mould surface. With the assumptions for ideal mapping and by applying some principles and theorems of differential geometry, the centerline trajectory of the composite tape is identified to follow the geodesic. The placement suitability of the composite tape is examined on three different types of non-developable mould surfaces and four criteria are derived. The developed criteria have been used to test the deposition process over several mould surfaces and the appropriate width for each mould surface is obtained by referring to these criteria.

  1. Outcomes and complications of self-expanding metal stent placement for malignant colonic obstruction in a single-center study.

    Science.gov (United States)

    Stankiewicz, Rafał; Kozieł, Sławomir; Pertkiewicz, Jan; Zieniewicz, Krzysztof

    2018-03-01

    Approximately 20% of cases of colorectal cancer are accompanied by acute colonic obstruction. While emergency colonic surgery is associated with high mortality and morbidity rates, placement of a self-expanding metal stent (SEMS) has been suggested as an alternative method. The SEMS placement can serve as either a definitive treatment in palliative cases or a bridge to surgery. To summarize the experience of our center in the treatment of malignant colonic obstruction using SEMS placement. A retrospective review was conducted of all patients who underwent a SEMS placement for colorectal stricture in the study period. The procedures were performed under fluoroscopic guidance with colonoscopic assistance, and uncovered stents were used in all patients. The study population consisted of 28 patients treated with SEMS placement due to malignant colonic obstruction. The majority of procedures were performed with palliative intent. The overall technical success rate was 96.5%, and clinical success was achieved in all of the successfully placed SEMSs. One fatal complication due to colonic perforation occurred. In the bridge-to-surgery group, all patients experienced tumor resection with no stoma creation. The SEMS placement is an optimal treatment in the vast majority of acute colonic obstruction cases. Due to the possibility of potentially fatal complications, SEMS procedures should be performed by proficient endoscopists.

  2. Improved Multiobjective Harmony Search Algorithm with Application to Placement and Sizing of Distributed Generation

    Directory of Open Access Journals (Sweden)

    Wanxing Sheng

    2014-01-01

    Full Text Available To solve the comprehensive multiobjective optimization problem, this study proposes an improved metaheuristic searching algorithm with combination of harmony search and the fast nondominated sorting approach. This is a kind of the novel intelligent optimization algorithm for multiobjective harmony search (MOHS. The detailed description and the algorithm formulating are discussed. Taking the optimal placement and sizing issue of distributed generation (DG in distributed power system as one example, the solving procedure of the proposed method is given. Simulation result on modified IEEE 33-bus test system and comparison with NSGA-II algorithm has proved that the proposed MOHS can get promising results for engineering application.

  3. Transesophageal Echocardiography-Guided Epicardial Left Ventricular Lead Placement by Video-Assisted Thoracoscopic Surgery in Nonresponders to Biventricular Pacing and Previous Chest Surgery.

    Science.gov (United States)

    Schroeder, Carsten; Chung, Jane M; Mackall, Judith A; Cakulev, Ivan T; Patel, Aaron; Patel, Sunny J; Hoit, Brian D; Sahadevan, Jayakumar

    2018-06-14

    The aim of the study was to study the feasibility, safety, and efficacy of transesophageal echocardiography-guided intraoperative left ventricular lead placement via a video-assisted thoracoscopic surgery approach in patients with failed conventional biventricular pacing. Twelve patients who could not have the left ventricular lead placed conventionally underwent epicardial left ventricular lead placement by video-assisted thoracoscopic surgery. Eight patients had previous chest surgery (66%). Operative positioning was a modified far lateral supine exposure with 30-degree bed tilt, allowing for groin and sternal access. To determine the optimal left ventricular location for lead placement, the left ventricular surface was divided arbitrarily into nine segments. These segments were transpericardially paced using a hand-held malleable pacing probe identifying the optimal site verified by transesophageal echocardiography. The pacing leads were screwed into position via a limited pericardiotomy. The video-assisted thoracoscopic surgery approach was successful in all patients. Biventricular pacing was achieved in all patients and all reported symptomatic benefit with reduction in New York Heart Association class from III to I-II (P = 0.016). Baseline ejection fraction was 23 ± 3%; within 1-year follow-up, the ejection fraction increased to 32 ± 10% (P = 0.05). The mean follow-up was 566 days. The median length of hospital stay was 7 days with chest tube removal between postoperative days 2 and 5. In patients who are nonresponders to conventional biventricular pacing, intraoperative left ventricular lead placement using anatomical and functional characteristics via a video-assisted thoracoscopic surgery approach is effective in improving heart failure symptoms. This optimized left ventricular lead placement is feasible and safe. Previous chest surgery is no longer an exclusion criterion for a video-assisted thoracoscopic surgery approach.

  4. The Monetary Policy of the NBU and its Impact on the Placement of Households’ Savings

    Directory of Open Access Journals (Sweden)

    Perepolkina Olena О.

    2018-03-01

    Full Text Available The article researches the efficiency of implementation of monetary policy in Ukraine in the context of determining the optimal ways to place households’ savings. The prospects of making deposits in both national and foreign currency as the most common directions of savings placement are considered. The research has identified that the main risks in the placement of savings by households as deposits in the national currency are the likelihood of bankruptcy of financial institutions, imperfection of the functioning of deposit guarantee system, inflationary fluctuations, and devaluation processes of the national monetary unit. Significant deterrents to the placement of foreign currency deposits are low interest rates, a large number of restrictions in the currency regulation, and a general low level of trust in the banking system. The directions of increasing the efficiency of monetary policy are proposed, that not only will increase the attractiveness of deposits for households, but also will create the basis for macroeconomic stabilization in Ukraine.

  5. Placement Stability, Cumulative Time in Care, and Permanency: Using Administrative Data from CPS to Track Placement Trajectories.

    Science.gov (United States)

    Hélie, Sonia; Poirier, Marie-Andrée; Esposito, Tonino; Turcotte, Daniel

    2017-11-17

    Objectives : The Quebec Youth Protection Act was amended in 2007. The main goal of this reform was to improve placement stability for children who are removed from their home for their protection. Among several legal provisions introduced was the establishment of maximum age-specific durations of out-of-home care, after which a plan must be established to provide stability for children placed in substitute care by finding permanent homes for them. The purpose of this study is (1) to examine trends in placement use and placement stability since the reform and (2) to document the current frequency of each type of placement setting, the cumulative time in care before the exit to permanency, and the sustainability of the permanency outcome. Methods: The study relies on 3 entry cohorts of all children investigated who received protection measures in the province of Quebec during 3 specific time frames before and after the reform ( n = 9620, 8676, 8425). Cohorts were observed for a period varying from 3 to 4 years. Administrative data from all 16 child protection agencies were used to track placement trajectory indicators and to compare cohorts. Results : There has been a decrease in the proportion of children receiving protection measures who were placed in care since the reform, and placement in kinship care has become more frequent among children placed. Placement stability improved slightly after the reform. Overall, for infants, the most frequent type of permanency attained is adoption, while reunification is the option most often indicated for older children. Some children are at a greater risk of experiencing unstable placement trajectories: young children have a high rate of reunification breakdown, some wait a long time to be adopted, and adolescents are frequently removed from the substitute care setting where they were supposed to stay until the age of 18. Conclusions : The results suggest interesting avenues for policy makers and service providers to improve

  6. Placement Stability, Cumulative Time in Care, and Permanency: Using Administrative Data from CPS to Track Placement Trajectories

    Directory of Open Access Journals (Sweden)

    Sonia Hélie

    2017-11-01

    Full Text Available Objectives: The Quebec Youth Protection Act was amended in 2007. The main goal of this reform was to improve placement stability for children who are removed from their home for their protection. Among several legal provisions introduced was the establishment of maximum age-specific durations of out-of-home care, after which a plan must be established to provide stability for children placed in substitute care by finding permanent homes for them. The purpose of this study is (1 to examine trends in placement use and placement stability since the reform and (2 to document the current frequency of each type of placement setting, the cumulative time in care before the exit to permanency, and the sustainability of the permanency outcome. Methods: The study relies on 3 entry cohorts of all children investigated who received protection measures in the province of Quebec during 3 specific time frames before and after the reform (n = 9620, 8676, 8425. Cohorts were observed for a period varying from 3 to 4 years. Administrative data from all 16 child protection agencies were used to track placement trajectory indicators and to compare cohorts. Results: There has been a decrease in the proportion of children receiving protection measures who were placed in care since the reform, and placement in kinship care has become more frequent among children placed. Placement stability improved slightly after the reform. Overall, for infants, the most frequent type of permanency attained is adoption, while reunification is the option most often indicated for older children. Some children are at a greater risk of experiencing unstable placement trajectories: young children have a high rate of reunification breakdown, some wait a long time to be adopted, and adolescents are frequently removed from the substitute care setting where they were supposed to stay until the age of 18. Conclusions: The results suggest interesting avenues for policy makers and service

  7. Placement Stability, Cumulative Time in Care, and Permanency: Using Administrative Data from CPS to Track Placement Trajectories

    Science.gov (United States)

    Hélie, Sonia; Poirier, Marie-Andrée; Esposito, Tonino; Turcotte, Daniel

    2017-01-01

    Objectives: The Quebec Youth Protection Act was amended in 2007. The main goal of this reform was to improve placement stability for children who are removed from their home for their protection. Among several legal provisions introduced was the establishment of maximum age-specific durations of out-of-home care, after which a plan must be established to provide stability for children placed in substitute care by finding permanent homes for them. The purpose of this study is (1) to examine trends in placement use and placement stability since the reform and (2) to document the current frequency of each type of placement setting, the cumulative time in care before the exit to permanency, and the sustainability of the permanency outcome. Methods: The study relies on 3 entry cohorts of all children investigated who received protection measures in the province of Quebec during 3 specific time frames before and after the reform (n = 9620, 8676, 8425). Cohorts were observed for a period varying from 3 to 4 years. Administrative data from all 16 child protection agencies were used to track placement trajectory indicators and to compare cohorts. Results: There has been a decrease in the proportion of children receiving protection measures who were placed in care since the reform, and placement in kinship care has become more frequent among children placed. Placement stability improved slightly after the reform. Overall, for infants, the most frequent type of permanency attained is adoption, while reunification is the option most often indicated for older children. Some children are at a greater risk of experiencing unstable placement trajectories: young children have a high rate of reunification breakdown, some wait a long time to be adopted, and adolescents are frequently removed from the substitute care setting where they were supposed to stay until the age of 18. Conclusions: The results suggest interesting avenues for policy makers and service providers to improve the

  8. Analysis of Vibrant Soundbridge placement against the round window membrane in a human cadaveric temporal bone model.

    NARCIS (Netherlands)

    Pennings, R.J.E.; Ho, A.; Brown, J.; Wijhe, R.G. van; Bance, M.

    2010-01-01

    OBJECTIVE: To evaluate optimal placement of the Floating Mass Transducer of the Vibrant Soundbridge (Med-El, Innsbruck, Austria) against the round window membrane, particularly the impact of interposed coupling fascia and of covering materials. METHOD: : Six fresh human cadaveric temporal bones were

  9. A study for proposal of use of regulatory T cells as a prognostic marker and establishing an optimal threshold level for their expression in chronic lymphocytic leukemia.

    Science.gov (United States)

    Dasgupta, Alakananda; Mahapatra, Manoranjan; Saxena, Renu

    2015-06-01

    Although regulatory T cells (Tregs) have been extensively studied in chronic lymphocytic leukemia, there is no uniform guideline or consensus regarding their use as a prognostic marker. This study describes the methodology used to develop an optimal threshold level for Tregs in these patients. Treg levels were assessed in the peripheral blood of 130 patients and 150 controls. Treg frequencies were linked to established prognostic markers as well as overall survival and time to first treatment. The cut-offs for Treg positivity were assessed by receiver operating characteristic (ROC) analysis. A cut-off of 5.7% for Treg cell percentage and of 35 cells/μL for absolute Treg cell count were determined as optimal in patients with CLL along with a median Treg percentage of 15.5% used to separate patients with low- and high-risk disease. The experiments presented here will possibly aid in the use of Treg frequencies as a potential prognostic marker in CLL.

  10. Offshore Wind Farm Layout Design Considering Optimized Power Dispatch Strategy

    DEFF Research Database (Denmark)

    Hou, Peng; Hu, Weihao; N. Soltani, Mohsen

    2017-01-01

    Offshore wind farm has drawn more and more attention recently due to its higher energy capacity and more freedom to occupy area. However, the investment is higher. In order to make a cost-effective wind farm, the wind farm layout should be optimized. The wake effect is one of the dominant factors...... leading to energy losses. It is expected that the optimized placement of wind turbines (WT) over a large sea area can lead to the best tradeoff between energy yields and capital investment. This paper proposes a novel way to position offshore WTs for a regular shaped wind farm. In addition to optimizing...... the direction of wind farm placement and the spacing between WTs, the control strategy’s impact on energy yields is also discussed. Since the problem is non-convex and lots of optimization variables are involved, an evolutionary algorithm, the particle swarm optimization algorithm (PSO), is adopted to find...

  11. On marker-based parentage verification via non-linear optimization.

    Science.gov (United States)

    Boerner, Vinzent

    2017-06-15

    Parentage verification by molecular markers is mainly based on short tandem repeat markers. Single nucleotide polymorphisms (SNPs) as bi-allelic markers have become the markers of choice for genotyping projects. Thus, the subsequent step is to use SNP genotypes for parentage verification as well. Recent developments of algorithms such as evaluating opposing homozygous SNP genotypes have drawbacks, for example the inability of rejecting all animals of a sample of potential parents. This paper describes an algorithm for parentage verification by constrained regression which overcomes the latter limitation and proves to be very fast and accurate even when the number of SNPs is as low as 50. The algorithm was tested on a sample of 14,816 animals with 50, 100 and 500 SNP genotypes randomly selected from 40k genotypes. The samples of putative parents of these animals contained either five random animals, or four random animals and the true sire. Parentage assignment was performed by ranking of regression coefficients, or by setting a minimum threshold for regression coefficients. The assignment quality was evaluated by the power of assignment (P[Formula: see text]) and the power of exclusion (P[Formula: see text]). If the sample of putative parents contained the true sire and parentage was assigned by coefficient ranking, P[Formula: see text] and P[Formula: see text] were both higher than 0.99 for the 500 and 100 SNP genotypes, and higher than 0.98 for the 50 SNP genotypes. When parentage was assigned by a coefficient threshold, P[Formula: see text] was higher than 0.99 regardless of the number of SNPs, but P[Formula: see text] decreased from 0.99 (500 SNPs) to 0.97 (100 SNPs) and 0.92 (50 SNPs). If the sample of putative parents did not contain the true sire and parentage was rejected using a coefficient threshold, the algorithm achieved a P[Formula: see text] of 1 (500 SNPs), 0.99 (100 SNPs) and 0.97 (50 SNPs). The algorithm described here is easy to implement

  12. Mathematics Placement at the University of Illinois

    Science.gov (United States)

    Ahlgren Reddy, Alison; Harper, Marc

    2013-01-01

    Data from the ALEKS-based placement program at the University of Illinois is presented visually in several ways. The placement exam (an ALEKS assessment) contains precise item-specific information and the data show many interesting properties of the student populations of the placement courses, which include Precalculus, Calculus, and Business…

  13. Product placement of computer games in cyberspace.

    Science.gov (United States)

    Yang, Heng-Li; Wang, Cheng-Shu

    2008-08-01

    Computer games are considered an emerging media and are even regarded as an advertising channel. By a three-phase experiment, this study investigated the advertising effectiveness of computer games for different product placement forms, product types, and their combinations. As the statistical results revealed, computer games are appropriate for placement advertising. Additionally, different product types and placement forms produced different advertising effectiveness. Optimum combinations of product types and placement forms existed. An advertisement design model is proposed for use in game design environments. Some suggestions are given for advertisers and game companies respectively.

  14. Tumour bed delineation for partial breast/breast boost radiotherapy: What is the optimal number of implanted markers?

    International Nuclear Information System (INIS)

    Kirby, Anna NM.; Jena, Rajesh; Harris, Emma J.; Evans, Phil M.; Crowley, Clare; Gregory, Deborah L.; Coles, Charlotte E.

    2013-01-01

    Purpose: International consensus has not been reached regarding the optimal number of implanted tumour bed (TB) markers for partial breast/breast boost radiotherapy target volume delineation. Four common methods are: insertion of 6 clips (4 radial, 1 deep and 1 superficial), 5 clips (4 radial and 1 deep), 1 clip at the chest wall, and no clips. We compared TB volumes delineated using 6, 5, 1 and 0 clips in women who have undergone wide-local excision (WLE) of breast cancer (BC) with full-thickness closure of the excision cavity, in order to determine the additional margin required for breast boost or partial breast irradiation (PBI) when fewer than 6 clips are used. Methods: Ten patients with invasive ductal BC who had undergone WLE followed by implantation of six fiducial markers (titanium clips) each underwent CT imaging for radiotherapy planning purposes. Retrospective processing of the DICOM image datasets was performed to remove markers and associated imaging artefacts, using an in-house software algorithm. Four observers outlined TB volumes on four different datasets for each case: (1) all markers present (CT 6M ); (2) the superficial marker removed (CT 5M ); (3) all but the chest wall marker removed (CT CW ); (4) all markers removed (CT 0M ). For each observer, the additional margin required around each of TB 0M , TB CW , and TB 5M in order to encompass TB 6M was calculated. The conformity level index (CLI) and differences in centre-of-mass (COM) between observers were quantified for CT 0M , CT CW , CT 5M , CT 6M . Results: The overall median additional margins required to encompass TB 6M were 8 mm (range 0–28 mm) for TB 0M , 5 mm (range 1–13 mm) for TB CW , and 2 mm (range 0–7 mm) for TB 5M . CLI were higher for TB volumes delineated using CT 6M (0.31) CT 5M (0.32) than for CT CW (0.19) and CT 0M (0.15). Conclusions: In women who have undergone WLE of breast cancer with full-thickness closure of the excision cavity and who are proceeding to PBI or

  15. Angioplasty and stent placement - carotid artery

    Science.gov (United States)

    ... medlineplus.gov/ency/article/002953.htm Angioplasty and stent placement - carotid artery To use the sharing features ... to remove plaque buildup ( endarterectomy ) Carotid angioplasty with stent placement Description Carotid angioplasty and stenting (CAS) is ...

  16. Multiobjective optimal placement of switches and protective devices in electric power distribution systems using ant colony optimization

    Energy Technology Data Exchange (ETDEWEB)

    Tippachon, Wiwat; Rerkpreedapong, Dulpichet [Department of Electrical Engineering, Kasetsart University, 50 Phaholyothin Rd., Ladyao, Jatujak, Bangkok 10900 (Thailand)

    2009-07-15

    This paper presents a multiobjective optimization methodology to optimally place switches and protective devices in electric power distribution networks. Identifying the type and location of them is a combinatorial optimization problem described by a nonlinear and nondifferential function. The multiobjective ant colony optimization (MACO) has been applied to this problem to minimize the total cost while simultaneously minimize two distribution network reliability indices including system average interruption frequency index (SAIFI) and system interruption duration index (SAIDI). Actual distribution feeders are used in the tests, and test results have shown that the algorithm can determine the set of optimal nondominated solutions. It allows the utility to obtain the optimal type and location of devices to achieve the best system reliability with the lowest cost. (author)

  17. Planned and unplanned terminations of foster care placements in the Netherlands: Relationships with characteristics of foster children and foster placements

    NARCIS (Netherlands)

    van Rooij, F.; Maaskant, A.; Weijers, I.; Weijers, D.; Hermanns, J.

    2015-01-01

    This study examined the role of placement and child characteristics in the unplanned termination of foster placements. Data were used from 169 foster children aged 0 to 20. Results showed that 35% of all foster placement terminations were unplanned. Outcomes of logistic regression analyses

  18. Take me where I want to go: Institutional prestige, advisor sponsorship, and academic career placement preferences.

    Directory of Open Access Journals (Sweden)

    Diogo L Pinheiro

    Full Text Available Placement in prestigious research institutions for STEM (science, technology, engineering, and mathematics PhD recipients is generally considered to be optimal. Yet some doctoral recipients are not interested in intensive research careers and instead seek alternative careers, outside but also within academe (for example teaching positions in Liberal Arts Schools. Recent attention to non-academic pathways has expanded our understanding of alternative PhD careers. However, career preferences and placements are also nuanced along the academic pathway. Existing research on academic careers (mostly research-centric has found that certain factors have a significant impact on the prestige of both the institutional placement and the salary of PhD recipients. We understand less, however, about the functioning of career preferences and related placements outside of the top academic research institutions. Our work builds on prior studies of academic career placement to explore the impact that prestige of PhD-granting institution, advisor involvement, and cultural capital have on the extent to which STEM PhDs are placed in their preferred academic institution types. What determines whether an individual with a preference for research oriented institutions works at a Research Extensive university? Or whether an individual with a preference for teaching works at a Liberal Arts college? Using survey data from a nationally representative sample of faculty in biology, biochemistry, civil engineering and mathematics at four different Carnegie Classified institution types (Research Extensive, Research Intensive, Master's I & II, and Liberal Arts Colleges, we examine the relative weight of different individual and institutional characteristics on institutional type placement. We find that doctoral institutional prestige plays a significant role in matching individuals with their preferred institutional type, but that advisor involvement only has an impact on those

  19. Take me where I want to go: Institutional prestige, advisor sponsorship, and academic career placement preferences.

    Science.gov (United States)

    Pinheiro, Diogo L; Melkers, Julia; Newton, Sunni

    2017-01-01

    Placement in prestigious research institutions for STEM (science, technology, engineering, and mathematics) PhD recipients is generally considered to be optimal. Yet some doctoral recipients are not interested in intensive research careers and instead seek alternative careers, outside but also within academe (for example teaching positions in Liberal Arts Schools). Recent attention to non-academic pathways has expanded our understanding of alternative PhD careers. However, career preferences and placements are also nuanced along the academic pathway. Existing research on academic careers (mostly research-centric) has found that certain factors have a significant impact on the prestige of both the institutional placement and the salary of PhD recipients. We understand less, however, about the functioning of career preferences and related placements outside of the top academic research institutions. Our work builds on prior studies of academic career placement to explore the impact that prestige of PhD-granting institution, advisor involvement, and cultural capital have on the extent to which STEM PhDs are placed in their preferred academic institution types. What determines whether an individual with a preference for research oriented institutions works at a Research Extensive university? Or whether an individual with a preference for teaching works at a Liberal Arts college? Using survey data from a nationally representative sample of faculty in biology, biochemistry, civil engineering and mathematics at four different Carnegie Classified institution types (Research Extensive, Research Intensive, Master's I & II, and Liberal Arts Colleges), we examine the relative weight of different individual and institutional characteristics on institutional type placement. We find that doctoral institutional prestige plays a significant role in matching individuals with their preferred institutional type, but that advisor involvement only has an impact on those with a

  20. A Cognitive Model of College Mathematics Placement

    Science.gov (United States)

    1989-08-01

    study focused on the precalculus -- calculus placement decision. The Cognitive model uses novel, or analysis level, placement test items in an attempt to...relative to the requirements of a precalculus course. Placement test scores may be partitioned to give analysis and non-analysis subtest scores which can...67 5.1.1 1989 Intercorrelations ....................................................................... 67 5.1.2 1989 Precalculus -Calculus

  1. The benefits of a 5-day dysphagia intensive placement

    OpenAIRE

    Cocks, N.; Harding, C.; Pritchard, M.

    2014-01-01

    Finding practical dysphagia opportunities for students pre-qualification is challenging. Discussions with clinicians led to the development of a new placement model. The placement was just five days and had an accompanying workbook. The current study aimed to evaluate the benefits of the placement. Data were analysed from 40 students who attended an adult dysphagia placement and 13 who attended a paediatric dysphagia placement. Measures included a pre and post self-rating questionnaire, quali...

  2. Consequences of fiducial marker error on three-dimensional computer animation of the temporomandibular joint

    Science.gov (United States)

    Leader, J. Ken, III; Boston, J. Robert; Rudy, Thomas E.; Greco, Carol M.; Zaki, Hussein S.

    2001-05-01

    Jaw motion has been used to diagnose jaw pain patients, and we have developed a 3D computer animation technique to study jaw motion. A customized dental clutch was worn during motion, and its consistent and rigid placement was a concern. The experimental protocol involved mandibular movements (vertical opening) and MR imaging. The clutch contained three motion markers used to collect kinematic data and four MR markers used as fiducial markers in the MR images. Fiducial marker misplacement was mimicked by analytically perturbing the position of the MR markers +/- 2, +/- 4, and +/- 6 degrees in the three anatomical planes. The percent difference between the original and perturbed MR marker position was calculated for kinematic parameters. The maximum difference across all perturbations for axial rotation, coronal rotation, sagittal rotation, axial translation, coronal translation, and sagittal translation were 176.85%, 191.84%, 0.64%, 9.76%, 80.75%, and 8.30%, respectively, for perturbing all MR markers, and 86.47%, 93.44%, 0.23%, 7.08%, 42.64%, and 13.64%, respectively, for perturbing one MR marker. The parameters representing movement in the sagittal plane, the dominant plane in vertical opening, were determined to be reasonably robust, while secondary movements in the axial and coronal planes were not considered robust.

  3. Optimal Colostomy Placement in Spinal Cord Injury Patients.

    Science.gov (United States)

    Xu, Jiashou; Dharmarajan, Sekhar; Johnson, Frank E

    2016-03-01

    Barring unusual circumstances, sigmoid colostomy is the optimal technique for management of defecation in spinal cord injury (SCI) patients. We sought to provide evidence that a sigmoid colostomy is not difficult to perform in SCI patients and has better long-term results. The St. Louis Department of Veterans Affairs has a Commission on Accreditation of Rehabilitation Facilities (CARF)-approved SCI Unit. We reviewed the operative notes on all SCI patients who received a colostomy for fecal management by three ASCRS-certified colorectal surgeons at the St. Louis Department of Veterans Affairs from January 1, 2007 to November 26, 2012. There were 27 operations for which the recorded indication for surgery suggested that the primary disorder was SCI. Fourteen had traumatic SCI of the thoracic and/or lumbar spine and were evaluable. Of these 14 patients, 12 had laparoscopic sigmoid colostomy and two had open sigmoid colostomy. We encountered one evaluable patient with a remarkably large amount of retroperitoneal bony debris who successfully underwent laparoscopic sigmoid colostomy. In conclusion, sigmoid colostomy is the consensus optimal procedure for fecal management in SCI patients. Laparoscopic procedures are preferred. Care providers should specify sigmoid colostomy when contacting a surgeon.

  4. Optimization Of ISSR Markers For DNA Fingerprinting In Stevia Rebaudiana Bertoni

    International Nuclear Information System (INIS)

    Lyena Watty Zuraine Ahmad; Lyena Watty Zuraine Ahmad; Azhar Mohamad; Mohamad Osman; Zarina Zainuddin; Fatin Izzati Mohd Khari

    2014-01-01

    ISSR or inter-simple sequence repeat is PCR based markers which required no prior DNA sequence knowledge of the studied organism. It has been proved to overcome limitations in other genetic marker techniques. In this study, 100 ISSR primers which comprised of 80 specific primers and 20 degenerate primers were used. All of the primers were tested on gradient temperatures from 45-55 degree Celsius. For positive amplification, 62 specific primers (77.5 %) and 18 degenerate primers (90.0 %) were recorded as working primers. The most efficient temperature for 25 primers was 55 degree Celsius. Marker derived from ISSR profiling is a powerful approach for identification and molecular classification of Stevia rebaudiana bertoni. (author)

  5. Product Placement and Brand Equity

    OpenAIRE

    Corniani, Margherita

    2003-01-01

    Product placement is the planned insertion of a brand within a movie, a fiction, etc. It can be used with other communication tools (i.e. advertising, sales promotions, etc.) in order to disseminate brand awareness and characterize brand image, developing brand equity. In global markets, product placement is particularly useful for improving brand equity of brands with a well established brand awareness.

  6. Optimal placement of biomass fuelled gas turbines for reduced losses

    International Nuclear Information System (INIS)

    Jurado, Francisco; Cano, Antonio

    2006-01-01

    This paper presents a method for the optimal location and sizing of biomass fuelled gas turbine power plants. Both profitability in using biomass and power loss are considered in the cost function. The first step is to assess the plant size that maximizes the profitability of the project. The second step is to determine the optimal location of the gas turbines in the electric system to minimize the power loss of the system

  7. Preoperative optimization of multi-organ failure following acute myocardial infarction and ischemic mitral regurgitation by placement of a transthoracic intra-aortic balloon pump.

    Science.gov (United States)

    Umakanthan, Ramanan; Dubose, Robert; Byrne, John G; Ahmad, Rashid M

    2010-10-01

    The management of acute myocardial infarction with resultant acute ischemic mitral regurgitation and acute multi-organ failure can prove to be a very challenging scenario. The presence of concomitant vascular disease can only serve to further compromise the complexity of the situation. We demonstrate a new indication for the transthoracic intra-aortic balloon pump as a preoperative means of unloading the heart and improving clinical outcome in such high-risk patients with severe vascular disease. We present the case of a 75-year-old man with a history of severe vascular disease who was transferred emergently to Vanderbilt University Medical Center with an acute inferolateral wall myocardial infarction resulting in severe acute ischemic mitral regurgitation and acute multi-organ failure. He presented with shock liver (serum glutamic-oxaloacetic transaminase [SGOT] of 958), renal failure (creatinine of 3.0), and respiratory failure with a pH of 7.18. Emergent cardiac catheterization revealed 100% occlusion of the left circumflex artery as well as severe ileofemoral disease. The advanced nature of his ileofemoral disease was such that the arterial access catheter occluded the right femoral artery. The duration of time that the catheter was in the artery led to transient limb ischemia with an elevation of his creatine phosphokinase (CPK) to 10,809. Balloon angioplasty followed by stent placement was successfully performed, which restored flow to the coronary vessel. Given the grave nature of the patient's condition, we were very concerned that immediate operative intervention for his condition would entail prohibitively high risk. In fact, the Society of Thoracic Surgeons predicted risk adjusted mortality was calculated to be 56%. In order to minimize patient mortality and morbidity, it was critical to help restore perfusion and organ recovery. Therefore, we decided that the chances for this patient's survival would improve if his condition could be optimized by

  8. PEG Tube Placement

    Directory of Open Access Journals (Sweden)

    Saptarshi Biswas

    2014-01-01

    Full Text Available Percutaneous endoscopic gastrostomy (PEG has been used for providing enteral access to patients who require long-term enteral nutrition for years. Although generally considered safe, PEG tube placement can be associated with many immediate and delayed complications. Buried bumper syndrome (BBS is one of the uncommon and late complications of percutaneous endoscopic gastrostomy (PEG placement. It occurs when the internal bumper of the PEG tube erodes into the gastric wall and lodges itself between the gastric wall and skin. This can lead to a variety of additional complications such as wound infection, peritonitis, and necrotizing fasciitis. We present here a case of buried bumper syndrome which caused extensive necrosis of the anterior abdominal wall.

  9. Dental hygiene student experiences in external placements in Australia.

    Science.gov (United States)

    Taylor, Jane A; Hayes, Melanie J; Wallace, Linda

    2012-05-01

    While placements in external locations are being increasingly used in dental education globally, few studies have explored the student learning experience at such placements. The purpose of this study was to investigate student experiences while on external placement in a baccalaureate dental hygiene program. A self-reporting questionnaire was distributed to final-year dental hygiene students (n=77) at the University of Newcastle, Australia, in 2010. The questionnaire included questions regarding the type of placement, experiences offered, supervision, resources available, and lasting impressions. Responding students were generally positive about their external placement experience and indicated that the majority of facilities provided them with the opportunity to provide direct patient care and perform clinical tasks typical of a practicing hygienist. However, there was a statistically significant difference in their opinions about discipline-focused and community placements. Students indicated that their external placement experience provided opportunities to learn more about time and patient management, including hands-on experience with specific clinical tasks. Ongoing evaluations are necessary to ensure that external placements meet both student needs and intended learning outcomes within dental hygiene programs.

  10. Optimized scalar promotion with load and splat SIMD instructions

    Science.gov (United States)

    Eichenberger, Alexander E; Gschwind, Michael K; Gunnels, John A

    2013-10-29

    Mechanisms for optimizing scalar code executed on a single instruction multiple data (SIMD) engine are provided. Placement of vector operation-splat operations may be determined based on an identification of scalar and SIMD operations in an original code representation. The original code representation may be modified to insert the vector operation-splat operations based on the determined placement of vector operation-splat operations to generate a first modified code representation. Placement of separate splat operations may be determined based on identification of scalar and SIMD operations in the first modified code representation. The first modified code representation may be modified to insert or delete separate splat operations based on the determined placement of the separate splat operations to generate a second modified code representation. SIMD code may be output based on the second modified code representation for execution by the SIMD engine.

  11. AFLPMax: a user-friendly application for computing the optimal number of amplified fragment length polymorphism markers needed in phylogenetic reconstruction.

    Science.gov (United States)

    García-Pereira, M J; Quesada, H; Caballero, A; Carvajal-Rodríguez, A

    2012-05-01

    Amplified fragment length polymorphisms (AFLPs) are widely used for phylogenetic inference especially in non-model species. Frequently, trees obtained with other nuclear or mitochondrial markers or with morphological information need additional resolution, increased branch support, or independent data sources (i.e. unlinked loci). In such cases, the use of AFLPs is a quick and cheap option. Computer simulation has shown that dominant AFLP markers lead to less accurate tree topologies than bi-allelic codominant markers such as SNPs, but this difference becomes negligible for shallow trees when using AFLP data sets that include a sufficiently large number of characters. Thus, determining how many AFLP characters are required to recover a given phylogeny is a key issue regarding the appropriateness of AFLPs for phylogenetic reconstruction. Here, we present a user-friendly, java-based graphical interface, AFLPMax, which executes an automatic pipeline of different programs providing the user with the optimal number of AFLP characters needed to recover a given phylogeny with high accuracy and support. Executables for Windows, linux and MacOS X operating systems, source code and user manual are available from: http://webs.uvigo.es/acraaj/AFLPMax.htm. © 2012 Blackwell Publishing Ltd.

  12. Risk factors for technical failure of endoscopic double self-expandable metallic stent placement by partial stent-in-stent method.

    Science.gov (United States)

    Kawakubo, Kazumichi; Kawakami, Hiroshi; Toyokawa, Yoshihide; Otani, Koichi; Kuwatani, Masaki; Abe, Yoko; Kawahata, Shuhei; Kubo, Kimitoshi; Kubota, Yoshimasa; Sakamoto, Naoya

    2015-01-01

    Endoscopic double self-expandable metallic stent (SEMS) placement by the partial stent-in-stent (PSIS) method has been reported to be useful for the management of unresectable hilar malignant biliary obstruction. However, it is technically challenging, and the optimal SEMS for the procedure remains unknown. The aim of this study was to identify the risk factors for technical failure of endoscopic double SEMS placement for unresectable malignant hilar biliary obstruction (MHBO). Between December 2009 and May 2013, 50 consecutive patients with MHBO underwent endoscopic double SEMS placement by the PSIS method. We retrospectively evaluated the rate of successful double SEMS placement and identified the risk factors for technical failure. The technical success rate for double SEMS placement was 82.0% (95% confidence interval [CI]: 69.2-90.2). On univariate analysis, the rate of technical failure was high in patients with metastatic disease and unilateral placement. Multivariate analysis revealed that metastatic disease was a significant risk factor for technical failure (odds ratio: 9.63, 95% CI: 1.11-105.5). The subgroup analysis after double guidewire insertion showed that the rate of technical success was higher in the laser-cut type SEMS with a large mesh and thick delivery system than in the braided type SEMS with a small mesh and thick delivery system. Metastatic disease was a significant risk factor for technical failure of double SEMS placement for unresectable MHBO. The laser-cut type SEMS with a large mesh and thin delivery system might be preferable for the PSIS procedure. © 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  13. A linear programming approach for placement of applicants to academic programs.

    Science.gov (United States)

    Kassa, Biniyam Asmare

    2013-01-01

    This paper reports a linear programming approach for placement of applicants to study programs developed and implemented at the college of Business & Economics, Bahir Dar University, Bahir Dar, Ethiopia. The approach is estimated to significantly streamline the placement decision process at the college by reducing required man hour as well as the time it takes to announce placement decisions. Compared to the previous manual system where only one or two placement criteria were considered, the new approach allows the college's management to easily incorporate additional placement criteria, if needed. Comparison of our approach against manually constructed placement decisions based on actual data for the 2012/13 academic year suggested that about 93 percent of the placements from our model concur with the actual placement decisions. For the remaining 7 percent of placements, however, the actual placements made by the manual system display inconsistencies of decisions judged against the very criteria intended to guide placement decisions by the college's program management office. Overall, the new approach proves to be a significant improvement over the manual system in terms of efficiency of the placement process and the quality of placement decisions.

  14. Optimal planning of electric vehicle charging station at the distribution system using hybrid optimization algorithm

    DEFF Research Database (Denmark)

    Awasthi, Abhishek; Venkitusamy, Karthikeyan; Padmanaban, Sanjeevikumar

    2017-01-01

    India's ever increasing population has made it necessary to develop alternative modes of transportation with electric vehicles being the most preferred option. The major obstacle is the deteriorating impact on the utility distribution system brought about by improper setup of these charging...... stations. This paper deals with the optimal planning (siting and sizing) of charging station infrastructure in the city of Allahabad, India. This city is one of the upcoming smart cities, where electric vehicle transportation pilot project is going on under Government of India initiative. In this context......, a hybrid algorithm based on genetic algorithm and improved version of conventional particle swarm optimization is utilized for finding optimal placement of charging station in the Allahabad distribution system. The particle swarm optimization algorithm re-optimizes the received sub-optimal solution (site...

  15. Immediate placement of endosseous implants into the extraction sockets.

    Science.gov (United States)

    Ebenezer, Vijay; Balakrishnan, K; Asir, R Vigil Dev; Sragunar, Banu

    2015-04-01

    Implant by definition "means any object or material, such as an alloplastic substance or other tissue, which is partial or completely inserted into the body for therapeutic, diagnostic, prosthetic, or experimental purpose." The placement of a dental implant in an extraction socket at the time of extraction or explantation is known as immediate implant placement whereas delayed placement of implant signifies the implant placement in edentulous areas where healing has completed with new bone formation after the loss of tooth/teeth. Recent idea goes by "why late when it can be done immediately." There are several advantages of immediate placement of implants, and lots of studies have been done. In this article, the advantages and disadvantages of immediate versus delayed placement of implants have been reviewed.

  16. Bayesian Optimization in High Dimensions via Random Embeddings

    NARCIS (Netherlands)

    Wang, Z.; Zoghi, M.; Hutter, F.; Matheson, D.; de Freitas, N.; Rossi, F.

    2013-01-01

    Bayesian optimization techniques have been successfully applied to robotics, planning, sensor placement, recommendation, advertising, intelligent user interfaces and automatic algorithm configuration. Despite these successes, the approach is restricted to problems of moderate dimension, and several

  17. What is the optimal alignment of the tibial and femoral components in knee arthroplasty?

    DEFF Research Database (Denmark)

    Gromov, Kirill; Korchi, Mounim; Thomsen, Morten G

    2014-01-01

    of positioning on survival and functional outcome was considered. Results - Many definitions exist when evaluating placement of femoral and tibial components. Implant alignment plays a role in both survival and functional outcome following primary TKA, as component malalignment can lead to increased failure......Background - Surgeon-dependent factors such as optimal implant alignment are thought to play a significant role in outcome following primary total knee arthroplasty (TKA). Exact definitions and references for optimal alignment are, however, still being debated. This overview of the literature...... describes different definitions of component alignment following primary TKA for (1) tibiofemoral alignment in the AP plane, (2) tibial and femoral component placement in the AP plane, (3) tibial and femoral component placement in the sagittal plane, and (4) rotational alignment of tibial and femoral...

  18. Mathematics Placement Test: Typical Results with Unexpected Outcomes

    Science.gov (United States)

    Ingalls, Victoria

    2011-01-01

    Based on the results of a prior case-study analysis of mathematics placement at one university, the mathematics department developed and piloted a mathematics placement test. This article describes the implementation process for a mathematics placement test and further analyzes the test results for the pilot group. As an unexpected result, the…

  19. The development of a model to predict the effects of worker and task factors on foot placements in manual material handling tasks.

    Science.gov (United States)

    Wagner, David W; Reed, Matthew P; Chaffin, Don B

    2010-11-01

    Accurate prediction of foot placements in relation to hand locations during manual materials handling tasks is critical for prospective biomechanical analysis. To address this need, the effects of lifting task conditions and anthropometric variables on foot placements were studied in a laboratory experiment. In total, 20 men and women performed two-handed object transfers that required them to walk to a shelf, lift an object from the shelf at waist height and carry the object to a variety of locations. Five different changes in the direction of progression following the object pickup were used, ranging from 45° to 180° relative to the approach direction. Object weights of 1.0 kg, 4.5 kg, 13.6 kg were used. Whole-body motions were recorded using a 3-D optical retro-reflective marker-based camera system. A new parametric system for describing foot placements, the Quantitative Transition Classification System, was developed to facilitate the parameterisation of foot placement data. Foot placements chosen by the subjects during the transfer tasks appeared to facilitate a change in the whole-body direction of progression, in addition to aiding in performing the lift. Further analysis revealed that five different stepping behaviours accounted for 71% of the stepping patterns observed. More specifically, the most frequently observed behaviour revealed that the orientation of the lead foot during the actual lifting task was primarily affected by the amount of turn angle required after the lift (R(2) = 0.53). One surprising result was that the object mass (scaled by participant body mass) was not found to significantly affect any of the individual step placement parameters. Regression models were developed to predict the most prevalent step placements and are included in this paper to facilitate more accurate human motion simulations and ergonomics analyses of manual material lifting tasks. STATEMENT OF RELEVANCE: This study proposes a method for parameterising the steps

  20. Hybrid Techniques for Optimizing Complex Systems

    Science.gov (United States)

    2009-12-01

    relay placement problem, we modeled the network as a mechanical system with springs and a viscous damper ⎯a widely used approach for solving optimization...fundamental mathematical tools in many branches of physics such as fluid and solid mechanics, and general relativity [108]. More recently, several

  1. Peculiarities of product placement in Lithuanian movies

    OpenAIRE

    Pilelienė, Lina; Jurgilaitė, Sigita

    2013-01-01

    The scientific problem analysed in the article is formulates as follows: how product placement is used in Lithuanian movies. The object of the article is product placement in Lithuanian movies, and the aim is to analyse the peculiarities of product placement in Lithuanian movies. Following methods were used to reveal the problem and reach the aim. Theoretical analysis of scientific literature was provided to construct the framework for the research. The analysis of current usage of product pl...

  2. Immediate placement of endosseous implants into the extraction sockets

    Directory of Open Access Journals (Sweden)

    Vijay Ebenezer

    2015-01-01

    Full Text Available Implant by definition "means any object or material, such as an alloplastic substance or other tissue, which is partial or completely inserted into the body for therapeutic, diagnostic, prosthetic, or experimental purpose." The placement of a dental implant in an extraction socket at the time of extraction or explantation is known as immediate implant placement whereas delayed placement of implant signifies the implant placement in edentulous areas where healing has completed with new bone formation after the loss of tooth/teeth. Recent idea goes by "why late when it can be done immediately." There are several advantages of immediate placement of implants, and lots of studies have been done. In this article, the advantages and disadvantages of immediate versus delayed placement of implants have been reviewed.

  3. MVMO-based approach for optimal placement and tuning of ...

    African Journals Online (AJOL)

    DR OKE

    differential evolution DE algorithm with adaptive crossover operator, .... x are assigned by using a sequential scheme which accounts for mean and ... the representative scenarios from probabilistic model based Monte Carlo ... Comparison of average convergence of MVMO-S with other metaheuristic optimization methods.

  4. Automated Fiber Placement of Advanced Materials (Preprint)

    National Research Council Canada - National Science Library

    Benson, Vernon M; Arnold, Jonahira

    2006-01-01

    .... ATK has been working with the Air Force Research Laboratory to foster improvements in the BMI materials and in the fiber placement processing techniques to achieve rates comparable to Epoxy placement rates...

  5. How do we facilitate international clinical placements for nursing students: A cross-sectional exploration of the structure, aims and objectives of placements.

    Science.gov (United States)

    Browne, Caroline A; Fetherston, Catherine M

    2018-07-01

    International clinical placements provide undergraduate students with a unique and complex clinical learning environment, to explore cultural awareness, experience different health care settings and achieve clinical competencies. Higher education institutions need to consider how to structure these placements to ensure appropriate and achievable aims and learning outcomes. In this study we described the structure, aims and learning outcomes associated with international clinical placement opportunities currently undertaken by Australian undergraduate nursing students in the Asia region. Forty eight percent (n = 18) of the institutions invited responded. Eight institutions met the inclusion criteria, one of which offered three placements in the region, resulting in 10 international placements for which data were provided. An online survey tool was used to collect data during August and September 2015 on international clinical placements conducted by the participating universities. Descriptive data on type and numbers of placements is presented, along with results from the content analysis conducted to explore data from open ended questions on learning aims and outcomes. One hundred students undertook 10 International Clinical Placements offered in the Asian region by eight universities. Variations across placements were found in the length of placement, the number of students participating, facilitator to student ratios and assessment techniques used. Five categories related to the aims of the programs were identified: 'becoming culturally aware through immersion', 'working with the community to promote health', 'understanding the role of nursing within the health care setting', 'translating theory into professional clinical practice', and 'developing relationships in international learning environments'. Four categories related to learning outcomes were identified: 'understanding healthcare and determinants of health', 'managing challenges', 'understanding the

  6. Monte Carlo simulations of the dosimetric impact of radiopaque fiducial markers for proton radiotherapy of the prostate

    Science.gov (United States)

    Newhauser, Wayne; Fontenot, Jonas; Koch, Nicholas; Dong, Lei; Lee, Andrew; Zheng, Yuanshui; Waters, Laurie; Mohan, Radhe

    2007-06-01

    Many clinical studies have demonstrated that implanted radiopaque fiducial markers improve targeting accuracy in external-beam radiotherapy, but little is known about the dose perturbations these markers may cause in patients receiving proton radiotherapy. The objective of this study was to determine what types of implantable markers are visible in setup radiographs and, at the same time, perturb the therapeutic proton dose to the prostate by less than 10%. The radiographic visibility of the markers was assessed by visual inspection of lateral setup radiographs of a pelvic phantom using a kilovoltage x-ray imaging system. The fiducial-induced perturbations in the proton dose were estimated with Monte Carlo simulations. The influence of marker material, size, placement depth and orientation within the pelvis was examined. The radiographic tests confirmed that gold and stainless steel markers were clearly visible and that titanium markers were not. The Monte Carlo simulations revealed that titanium and stainless steel markers minimally perturbed the proton beam, but gold markers cast unacceptably large dose shadows. A 0.9 mm diameter, 3.1 mm long cylindrical stainless steel marker provides good radiographic visibility yet perturbs the proton dose distribution in the prostate by less than 8% when using a parallel opposed lateral beam arrangement.

  7. Algorithms for selecting informative marker panels for population assignment.

    Science.gov (United States)

    Rosenberg, Noah A

    2005-11-01

    Given a set of potential source populations, genotypes of an individual of unknown origin at a collection of markers can be used to predict the correct source population of the individual. For improved efficiency, informative markers can be chosen from a larger set of markers to maximize the accuracy of this prediction. However, selecting the loci that are individually most informative does not necessarily produce the optimal panel. Here, using genotypes from eight species--carp, cat, chicken, dog, fly, grayling, human, and maize--this univariate accumulation procedure is compared to new multivariate "greedy" and "maximin" algorithms for choosing marker panels. The procedures generally suggest similar panels, although the greedy method often recommends inclusion of loci that are not chosen by the other algorithms. In seven of the eight species, when applied to five or more markers, all methods achieve at least 94% assignment accuracy on simulated individuals, with one species--dog--producing this level of accuracy with only three markers, and the eighth species--human--requiring approximately 13-16 markers. The new algorithms produce substantial improvements over use of randomly selected markers; where differences among the methods are noticeable, the greedy algorithm leads to slightly higher probabilities of correct assignment. Although none of the approaches necessarily chooses the panel with optimal performance, the algorithms all likely select panels with performance near enough to the maximum that they all are suitable for practical use.

  8. STUDENT PLACEMENT

    African Journals Online (AJOL)

    User

    students express lack of interest in the field they are placed, it ... be highly motivated to learn than students placed in a department ... the following research questions. Research Questions. •. Did the criteria used by Mekelle. University for placement of students into different departments affect the academic performance of ...

  9. In vitro protocol for validating interface pressure sensors for therapeutic compression garments: Importance of sphygmomanometer placement and initial cuff diameter

    Directory of Open Access Journals (Sweden)

    Inhwa Jung

    2018-02-01

    Full Text Available An optimal protocol is needed to validate the performance of future interface pressure sensors for compression garments when using a sphygmomanometer. PicoPress® was used on a rigid plastic cylinder (r=4 cm. An FDA-cleared aneroid sphygmomanometer was used to apply pressures from 10-60 mmHg with a diameter of 8 cm or 12 cm placed either beneath the sphygmomanometer’s airbag or fabric cuff. A two-tail t-test was performed (P<0.05 for significance for all applied pressures. PicoPress® outputs vary with sensor placement (airbag vs fabric cuff and the initial cuff diameter. Sensor placement overlying the sphygmomanometer’s fabric cuff compared to the airbag led to significantly higher pressures (37%-135% depending on the cuff diameter size. These differences were nearly all statistically significant (P<0.05. Validation of new interface pressure sensors deploying a sphygmomanometer for calibration should specify the location of sensor placement location and initial diameter with a preference for placement under the airbag.

  10. Actuator Placement Via Genetic Algorithm for Aircraft Morphing

    Science.gov (United States)

    Crossley, William A.; Cook, Andrea M.

    2001-01-01

    This research continued work that began under the support of NASA Grant NAG1-2119. The focus of this effort was to continue investigations of Genetic Algorithm (GA) approaches that could be used to solve an actuator placement problem by treating this as a discrete optimization problem. In these efforts, the actuators are assumed to be "smart" devices that change the aerodynamic shape of an aircraft wing to alter the flow past the wing, and, as a result, provide aerodynamic moments that could provide flight control. The earlier work investigated issued for the problem statement, developed the appropriate actuator modeling, recognized the importance of symmetry for this problem, modified the aerodynamic analysis routine for more efficient use with the genetic algorithm, and began a problem size study to measure the impact of increasing problem complexity. The research discussed in this final summary further investigated the problem statement to provide a "combined moment" problem statement to simultaneously address roll, pitch and yaw. Investigations of problem size using this new problem statement provided insight into performance of the GA as the number of possible actuator locations increased. Where previous investigations utilized a simple wing model to develop the GA approach for actuator placement, this research culminated with application of the GA approach to a high-altitude unmanned aerial vehicle concept to demonstrate that the approach is valid for an aircraft configuration.

  11. Radiography students' perceptions of clinical placements - A Nigerian perspective

    International Nuclear Information System (INIS)

    Ogbu, S.O.I.

    2008-01-01

    Purpose: To assess undergraduate radiography student perception of clinical placements and to evaluate their clinical learning experiences. Methods: To evaluate student perception of clinical placements, a Likert-scale questionnaire was used to assess clinical practice, the practice-learning environment. One hundred and seventy-eight undergraduate [student] radiographers participated in the study. Results: The students indicated they had adequate and enjoyed their time on the clinical placement. They also indicated the qualified staff was supportive, friendly and approachable. The students were able to achieve their learning outcomes during the placement. However placement venues, according to the students, had inadequate learning resources. No radiographic/medical imaging research findings, whether locally generated or otherwise, were used in clinical practice. Conclusions: Clinical placements had adequate student support. It provided a pleasant learning experience for the students and it enhanced their skills. Staff was willing and available to assist learning. Nevertheless, the training institutions, professional body and clinical placement providers need to make an effort to address inadequate learning resources (e.g. IT, library, study rooms) as well as the non-utilization of radiographic/medical imaging research findings

  12. Trade-offs and efficiencies in optimal budget-constrained multispecies corridor networks

    Science.gov (United States)

    Bistra Dilkina; Rachel Houtman; Carla P. Gomes; Claire A. Montgomery; Kevin S. McKelvey; Katherine Kendall; Tabitha A. Graves; Richard Bernstein; Michael K. Schwartz

    2016-01-01

    Conservation biologists recognize that a system of isolated protected areas will be necessary but insufficient to meet biodiversity objectives. Current approaches to connecting core conservation areas through corridors consider optimal corridor placement based on a single optimization goal: commonly, maximizing the movement for a target species across a...

  13. Delayed ischemic cecal perforation despite optimal decompression after placement of a self-expanding metal stent: report of a case

    DEFF Research Database (Denmark)

    Knop, Filip Krag; Pilsgaard, Bo; Meisner, Søren

    2004-01-01

    Endoscopic deployment of self-expanding metal stents offers an alternative to surgical intervention in rectocolonic obstructions. Reported clinical failures in the literature are all related to the site of stent placement. We report a case of serious intra-abdominal disease after technically...... and clinically successful stent deployment: a potentially dangerous situation of which the surgeon should be aware. A previously healthy 72-year-old female was referred to our department with symptoms of an obstructing colorectal tumor. Successful stent placement resulted in resolution of the obstructive......, probably caused by ischemic conditions developed before stent-decompression of the colon was revealed during the operation. The patient died in the postoperative course. We discuss the observation of patients treated with self-expanding metal stents based on the selection-strategy used to allocate patients...

  14. Delayed ischemic cecal perforation despite optimal decompression after placement of a self-expanding metal stent: report of a case

    DEFF Research Database (Denmark)

    Knop, Filip Krag; Pilsgaard, Bo; Meisner, Søren

    2004-01-01

    Endoscopic deployment of self-expanding metal stents offers an alternative to surgical intervention in rectocolonic obstructions. Reported clinical failures in the literature are all related to the site of stent placement. We report a case of serious intra-abdominal disease after technically...... and clinically successful stent deployment: a potentially dangerous situation of which the surgeon should be aware. A previously healthy 72-year-old female was referred to our department with symptoms of an obstructing colorectal tumor. Successful stent placement resulted in resolution of the obstructive...... condition. Three days after stent deployment, x-ray examinations revealed a small-bowel obstruction and emergency surgery was performed. Intraoperative findings demonstrated a segment of ileum fixated to the tumor in the small pelvis, resulting in the obstructive condition. Furthermore, a cecal perforation...

  15. Selection and placement of best management practices used to reduce water quality degradation in Lincoln Lake watershed

    Science.gov (United States)

    Rodriguez, Hector German; Popp, Jennie; Maringanti, Chetan; Chaubey, Indrajeet

    2011-01-01

    An increased loss of agricultural nutrients is a growing concern for water quality in Arkansas. Several studies have shown that best management practices (BMPs) are effective in controlling water pollution. However, those affected with water quality issues need water management plans that take into consideration BMPs selection, placement, and affordability. This study used a nondominated sorting genetic algorithm (NSGA-II). This multiobjective algorithm selects and locates BMPs that minimize nutrients pollution cost-effectively by providing trade-off curves (optimal fronts) between pollutant reduction and total net cost increase. The usefulness of this optimization framework was evaluated in the Lincoln Lake watershed. The final NSGA-II optimization model generated a number of near-optimal solutions by selecting from 35 BMPs (combinations of pasture management, buffer zones, and poultry litter application practices). Selection and placement of BMPs were analyzed under various cost solutions. The NSGA-II provides multiple solutions that could fit the water management plan for the watershed. For instance, by implementing all the BMP combinations recommended in the lowest-cost solution, total phosphorous (TP) could be reduced by at least 76% while increasing cost by less than 2% in the entire watershed. This value represents an increase in cost of 5.49 ha-1 when compared to the baseline. Implementing all the BMP combinations proposed with the medium- and the highest-cost solutions could decrease TP drastically but will increase cost by 24,282 (7%) and $82,306 (25%), respectively.

  16. Entry-Level Placement Scores for the 1996-97 Academic Year.

    Science.gov (United States)

    Padron, Eduardo J.

    This memorandum reviews the implementation of new, state-mandated placement criteria at Florida's Miami-Dade Community College (MDCC). The first section focuses on placement criteria for degree-seeking students, indicating that MDCC uses scores on the Florida College Entry-Level Placement Test for making placement decisions in reading, writing,…

  17. Delayed bracket placement in orthodontic treatment

    Directory of Open Access Journals (Sweden)

    Chandra Wigati

    2008-12-01

    Full Text Available Background: Beside bracket position, the timing of bracket placement is one of the most essential in orthodontic treatment with fixed appliances. Even it seems simple the timing of bracket placement can be crucial and significantly influence the result of orthodontic treatment. However it is often found brackets are placed without complete understanding of its purpose and effects, which could be useless and even detrimental for the case. Purpose: The aim of this case report is to show that the timing of bracket placement could be different depending on the cases. Case: Five different cases are presented here with different timing of bracket placement. Case management: On these cases, brackets were placed on the upper arch first, on the lower arch first, or even only on some teeth first. Good and efficient orthodontic treatment results were achieved. Conclusion: For every orthodontic case, from the very beginning of treatment, bracket should be placed with the end result in mind. If brackets are correctly placed at a correct time, better treatment result could be achieved without unnecessary round tripping tooth movement.

  18. A distributed parallel genetic algorithm of placement strategy for virtual machines deployment on cloud platform.

    Science.gov (United States)

    Dong, Yu-Shuang; Xu, Gao-Chao; Fu, Xiao-Dong

    2014-01-01

    The cloud platform provides various services to users. More and more cloud centers provide infrastructure as the main way of operating. To improve the utilization rate of the cloud center and to decrease the operating cost, the cloud center provides services according to requirements of users by sharding the resources with virtualization. Considering both QoS for users and cost saving for cloud computing providers, we try to maximize performance and minimize energy cost as well. In this paper, we propose a distributed parallel genetic algorithm (DPGA) of placement strategy for virtual machines deployment on cloud platform. It executes the genetic algorithm parallelly and distributedly on several selected physical hosts in the first stage. Then it continues to execute the genetic algorithm of the second stage with solutions obtained from the first stage as the initial population. The solution calculated by the genetic algorithm of the second stage is the optimal one of the proposed approach. The experimental results show that the proposed placement strategy of VM deployment can ensure QoS for users and it is more effective and more energy efficient than other placement strategies on the cloud platform.

  19. A Distributed Parallel Genetic Algorithm of Placement Strategy for Virtual Machines Deployment on Cloud Platform

    Directory of Open Access Journals (Sweden)

    Yu-Shuang Dong

    2014-01-01

    Full Text Available The cloud platform provides various services to users. More and more cloud centers provide infrastructure as the main way of operating. To improve the utilization rate of the cloud center and to decrease the operating cost, the cloud center provides services according to requirements of users by sharding the resources with virtualization. Considering both QoS for users and cost saving for cloud computing providers, we try to maximize performance and minimize energy cost as well. In this paper, we propose a distributed parallel genetic algorithm (DPGA of placement strategy for virtual machines deployment on cloud platform. It executes the genetic algorithm parallelly and distributedly on several selected physical hosts in the first stage. Then it continues to execute the genetic algorithm of the second stage with solutions obtained from the first stage as the initial population. The solution calculated by the genetic algorithm of the second stage is the optimal one of the proposed approach. The experimental results show that the proposed placement strategy of VM deployment can ensure QoS for users and it is more effective and more energy efficient than other placement strategies on the cloud platform.

  20. A Sea-of-Gates Style FPGA Placement Algorithm

    Directory of Open Access Journals (Sweden)

    Kalapi Roy

    1996-01-01

    Full Text Available Field Programmable Gate Arrays (FPGAs have a pre-defined chip boundary with fixed cell locations and routing resources. Placement objectives for flexible architectures (e.g., the standard cell design style such as minimization of chip area do not reflect the primary placement goals for FPGAs. For FPGAs, the layout tools must seek 100% routability within the architectural constraints. Routability and congestion estimates must be made directly based on the demand and availability of routing resources for detailed routing of the particular FPGA. We. present a hierarchical placement approach consisting of two phases: a global placement phase followed by a detailed placement phase. The global placement phase minimizes congestion estimates of the global routing regions and satisfies all constraints at a coarser level. The detailed placer seeks to maximize the routability of the FPGA by considering factors which cause congestion at the detailed routing level and to precisely satisfy all of the constraints. Despite having limited knowledge about the gate level architectural details, we have achieved a 90%reduction in the number of unrouted nets in comparison to an industrial tool (the only other tool developed specifically for this architecture.

  1. Confirmation of Essure placement using transvaginal ultrasound.

    Science.gov (United States)

    Veersema, Sebastiaan; Vleugels, Michel; Koks, Caroline; Thurkow, Andreas; van der Vaart, Huub; Brölmann, Hans

    2011-01-01

    To evaluate the protocol for confirmation of satisfactory Essure placement using transvaginal ultrasound. Prospective multicenter cohort study (Canadian Task Force classification II-2). Outpatient departments of 4 teaching hospitals in the Netherlands. Eleven hundred forty-five women who underwent hysteroscopic sterilization using the Essure device between March 2005 and December 2007. Transvaginal ultrasound examination 12 weeks after uncomplicated successful bilateral placement or as indicated according to the transvaginal ultrasound protocol after 4 weeks, and hysterosalpingography (HSG) at 12 weeks to confirm correct placement of the device after 3 months. The rate of successful placement was 88.4% initially. In 164 women (15%), successful placement was confirmed at HSG according the protocol. In 9 patients (0.84%), incorrect position of the device was observed at HSG. The cumulative pregnancy rate after 18 months was 3.85 per thousand women. Transvaginal ultrasound should be the first diagnostic test used to confirm the adequacy of hysteroscopic Essure sterilization because it is minimally invasive, averts ionizing radiation, and does not decrease the effectiveness of the Essure procedure. Copyright © 2011 AAGL. Published by Elsevier Inc. All rights reserved.

  2. Plant breeding with marker-assisted selection in Brazil

    Directory of Open Access Journals (Sweden)

    Ney Sussumu Sakiyama

    2014-03-01

    Full Text Available Over the past three decades, molecular marker studies reached extraordinary advances, especially for sequencing and bioinformatics techniques. Marker-assisted selection became part of the breeding program routines of important seed companies, in order to accelerate and optimize the cultivar developing processes. Private seed companies increasingly use marker-assisted selection, especially for the species of great importance to the seed market, e.g. corn, soybean, cotton, and sunflower. In the Brazilian public institutions few breeding programs use it efficiently. The possible reasons are: lack of know-how, lack of appropriate laboratories, few validated markers, high cost, and lack of urgency in obtaining cultivars. In this article we analyze the use and the constraints of marker-assisted selection in plant breeding programs of Brazilian public institutes

  3. Implementing data placement strategies for the CMS experiment based on a popularity mode

    CERN Multimedia

    CERN. Geneva; Barreiro Megino, Fernando Harald

    2012-01-01

    During the first two years of data taking, the CMS experiment has collected over 20 PetaBytes of data and processed and analyzed it on the distributed, multi-tiered computing infrastructure on the WorldWide LHC Computing Grid. Given the increasing data volume that has to be stored and efficiently analyzed, it is a challenge for several LHC experiments to optimize and automate the data placement strategies in order to fully profit of the available network and storage resources and to facilitate daily computing operations. Building on previous experience acquired by ATLAS, we have developed the CMS Popularity Service that tracks file accesses and user activity on the grid and will serve as the foundation for the evolution of their data placement. A fully automated, popularity-based site-cleaning agent has been deployed in order to scan Tier2 sites that are reaching their space quota and suggest obsolete, unused data that can be safely deleted without disrupting analysis activity. Future work will be to demons...

  4. Controller Placement Algorithms in Software Defined Network - A Review of Trends and Challenges

    Directory of Open Access Journals (Sweden)

    Yoon Si-Kee

    2017-01-01

    Full Text Available Traditional network architectures are complex to manage, comparatively static, rigid and difficult to make changes for new innovation. The proprietary devices in such architectures are based on manual configuration which are unwieldy and error-prone. Software Defined Network (SDN which is described as a new network paradigm that decouple the control plane from data plane are capable to solve today's network issues and improve the network performance. Nevertheless, among so many challenges and research opportunity in SDN, Controller Placement Problem (CPP is said to be the most important issues which can directly affect the overall network performance. Thus far, the issue regarding the CPP and its challenge has not been completely reviewed and discussed properly in any other papers. In this paper, we provide a comprehensive review on several optimized controller placement problem algorithms in SDN. This paper also highlights some limitations of the reviewed methods and also emphasizes on suitable approach to address the aforementioned problems.

  5. Implementing data placement strategies for the CMS experiment based on a popularity model

    CERN Document Server

    Giordano, Domenico

    2012-01-01

    During the first two years of data taking, the CMS experiment has collected over 20 PetaBytes of data and processed and analyzed it on the distributed, multi-tiered computing infrastructure on the WorldWide LHC Computing Grid. Given the increasing data volume that has to be stored and efficiently analyzed, it is a challenge for several LHC experiments to optimize and automate the data placement strategies in order to fully profit of the available network and storage resources and to facilitate daily computing operations. Building on previous experience acquired by ATLAS, we have developed the CMS Popularity Service that tracks file accesses and user activity on the grid and will serve as the foundation for the evolution of their data placement. A fully automated, popularity-based site-cleaning agent has been deployed in order to scan Tier-2 sites that are reaching their space quota and suggest obsolete, unused data that can be safely deleted without disrupting analysis activity. Future work will be to demonst...

  6. Brand placement prominence: good for memory! Bad for attitudes?

    NARCIS (Netherlands)

    van Reijmersdal, E.

    2009-01-01

    This paper presents two laws about the effects of brand placement on audience reactions. This article presents two laws about the effects of brand placement on audience reactions. Brand placement is the compensated inclusion of brands or brand identifiers within media programming. The first law

  7. How media factors affect audience responses to brand placement

    NARCIS (Netherlands)

    van Reijmersdal, E.; Smit, E.; Neijens, P.

    2010-01-01

    This study investigates the influence of media factors on brand placement effects in a real-life setting. Although many studies on brand placement have been conducted, insights into context effects on brand placement reactions are scarce. The impact of objective and subjective media context factors

  8. Impacted material placement plans

    International Nuclear Information System (INIS)

    Hickey, M.J.

    1997-01-01

    Impacted material placement plans (IMPP) are documents identifying the essential elements in placing remediation wastes into disposal facilities. Remediation wastes or impacted material(s) are those components used in the construction of the disposal facility exclusive of the liners and caps. The components might include soils, concrete, rubble, debris, and other regulatory approved materials. The IMPP provides the details necessary for interested parties to understand the management and construction practices at the disposal facility. The IMPP should identify the regulatory requirements from applicable DOE Orders, the ROD(s) (where a part of a CERCLA remedy), closure plans, or any other relevant agreements or regulations. Also, how the impacted material will be tracked should be described. Finally, detailed descriptions of what will be placed and how it will be placed should be included. The placement of impacted material into approved on-site disposal facilities (OSDF) is an integral part of gaining regulatory approval. To obtain this approval, a detailed plan (Impacted Material Placement Plan [IMPP]) was developed for the Fernald OSDF. The IMPP provides detailed information for the DOE, site generators, the stakeholders, regulatory community, and the construction subcontractor placing various types of impacted material within the disposal facility

  9. Do Work Placements Improve Final Year Academic Performance or Do High-Calibre Students Choose to Do Work Placements?

    Science.gov (United States)

    Jones, C. M.; Green, J. P.; Higson, H. E.

    2017-01-01

    This study investigates whether the completion of an optional sandwich work placement enhances student performance in final year examinations. Using Propensity Score Matching, our analysis departs from the literature by controlling for self-selection. Previous studies may have overestimated the impact of sandwich work placements on performance…

  10. Clinical Evaluation and Cost-Effectiveness Analysis of Serum Tumor Markers in Lung Cancer

    Directory of Open Access Journals (Sweden)

    Rong Wang

    2013-01-01

    Full Text Available The detection of serum tumor markers is valuable for the early diagnosis of lung cancer. Tumor markers are frequently used for the management of cancer patients. However, single markers are less efficient but marker combinations increase the cost, which is troublesome for clinics. To find an optimal serum marker combination panel that benefits the patients and the medical management system as well, four routine lung cancer serum markers (SCCA, NSE, CEA, and CYFRA21-1 were evaluated individually and in combination. Meanwhile, the costs and effects of these markers in clinical practice in China were assessed by cost-effectiveness analysis. As expected, combinations of these tumor markers improved their sensitivity for lung cancer and different combination panels had their own usefulness. NSE + CEA + CYFRA21-1 was the optimal combination panel with highest Youden’s index (0.64, higher sensitivity (75.76%, and specificity (88.57%, which can aid the clinical diagnosis of lung cancer. Nevertheless, the most cost-effective combination was SCCA + CEA, which can be used to screen the high-risk group.

  11. Realistic Approach for Phasor Measurement Unit Placement

    DEFF Research Database (Denmark)

    Rather, Zakir Hussain; Chen, Zhe; Thøgersen, Paul

    2015-01-01

    This paper presents a realistic cost-effectivemodel for optimal placement of phasor measurement units (PMUs) for complete observability of a power system considering practical cost implications. The proposed model considers hidden or otherwise unaccounted practical costs involved in PMU...... installation. Consideration of these hidden but significant and integral part of total PMU installation costs was inspired from practical experience on a real-life project. The proposedmodel focuses on the minimization of total realistic costs instead of a widely used theoretical concept of a minimal number...... of PMUs. The proposed model has been applied to IEEE 14-bus, IEEE 24-bus, IEEE 30-bus, New England 39-bus, and large power system of 300 buses and real life Danish grid. A comparison of the presented results with those reported by traditionalmethods has also been shown to justify the effectiveness...

  12. Optimal Placement of Actors in WSANs Based on Imposed Delay Constraints

    Directory of Open Access Journals (Sweden)

    Chunxi Yang

    2014-01-01

    Full Text Available Wireless Sensor and Actor Networks (WSANs refer to a group of sensors and actors linked by wireless medium to probe environment and perform specific actions. Such certain actions should always be taken before a deadline when an event of interest is detected. In order to provide such services, the whole monitor area is divided into several virtual areas and nodes in the same area form a cluster. Clustering of the WSANs is often pursued to give that each actor acts as a cluster-head. The number of actors is related to the size and the deployment of WSANs cluster. In this paper, we find a method to determine the accurate number of actors which enables them to receive data and take actions in an imposed time-delay. The k-MinTE and the k-MaxTE clustering algorithm are proposed to form the minimum and maximum size of cluster, respectively. In those clustering algorithms, actors are deployed in such a way that sensors could route data to actors within k hops. Then, clusters are arranged by the regular hexagon. At last, we evaluate the placement of actors and results show that our approach is effective.

  13. Deep percolation in greenhouse-cultivated celery using the technique of subsurface film strips placement

    Directory of Open Access Journals (Sweden)

    Zhida Du

    2014-05-01

    Full Text Available To reduce the deep percolation during greenhouse vegetable cultivation, the technique of subsurface film strips placement was tested. Four treatments with two kinds of cross-sections (flat and U-shaped and two different spacings (10 cm and 40 cm of subsurface film strips were arranged in a greenhouse before planting celery. At the same time, a non-film treatment was arranged for comparison. Soil water content was measured and irrigation time was adjusted according to the soil water content. Evapotranspiration of celery during growth was calculated by the method of energy balance and the deep percolation was calculated by the equation of water balance. Deep percolation was reduced in all experimental treatments. Greater reduction in deep percolation was observed when using U-shaped cross-section strips compared with that using the flat cross-section strips. In addition, greater reduction in deep percolation was observed when the spacing between the film strips was smaller. The results of this test showed that the technique of subsurface film strips placement can reduce deep percolation and conserve irrigation water for greenhouse vegetables cultivation. However, the optimal layout variables for the use of the technique of subsurface film strips placement need further experimental and numerical analysis.

  14. Optimal siting and sizing of wind farms

    NARCIS (Netherlands)

    Cetinay-Iyicil, H.; Kuipers, F.A.; Guven, A. Nezih

    2017-01-01

    In this paper, we propose a novel technique to determine the optimal placement of wind farms, thereby taking into account wind characteristics and electrical grid constraints. We model the long-term variability of wind speed using a Weibull distribution according to wind direction intervals, and

  15. Placement education pedagogy as social participation: what are students really learning?

    Science.gov (United States)

    Kell, Clare

    2014-03-01

    This paper draws on empirical fieldwork data of naturally occurring UK physiotherapy placement education to make visible how education is actually carried out and suggest what students may be learning through their placement interactions. The data challenge everyone involved in placement education design and practice to consider the values and practices students are learning to perpetuate through placement education experiences. The researcher undertook an ethnomethodologically informed ethnographic observation of naturally occurring physiotherapy placement education in two UK NHS placement sites. This study adopted a social perspective of learning to focus on the minutiae of placement educator, student and patient interaction practices during student-present therapeutic activities. Two days of placement for each of six senior students were densely recorded in real-time focussing specifically on the verbal, kinesics and proxemics-based elements of the participants' interaction practices. Repeated cycles of data analysis suggested consistent practices irrespective of the placement, educators, students or patients. The data suggest that placement education is a powerful situated learning environment in which students see, experience and learn to reproduce the physiotherapy practices valued by the local placement. Consistently, placement educators and students co-produced patient-facing activities as spectacles of physiotherapy-as-science. In each setting, patients were used as person-absent audiovisual teaching aids from which students learnt to make a case for physiotherapy intervention. The paper challenges physiotherapists and other professions using work-placement education to look behind the rhetoric of their placement documentation and explore the reality of students' learning in the field. The UK-based physiotherapy profession may wish to consider further the possible implications of its self-definition as a 'science-based healthcare profession' on its in

  16. Full automatic fiducial marker detection on coil arrays for accurate instrumentation placement during MRI guided breast interventions

    Science.gov (United States)

    Filippatos, Konstantinos; Boehler, Tobias; Geisler, Benjamin; Zachmann, Harald; Twellmann, Thorsten

    2010-02-01

    With its high sensitivity, dynamic contrast-enhanced MR imaging (DCE-MRI) of the breast is today one of the first-line tools for early detection and diagnosis of breast cancer, particularly in the dense breast of young women. However, many relevant findings are very small or occult on targeted ultrasound images or mammography, so that MRI guided biopsy is the only option for a precise histological work-up [1]. State-of-the-art software tools for computer-aided diagnosis of breast cancer in DCE-MRI data offer also means for image-based planning of biopsy interventions. One step in the MRI guided biopsy workflow is the alignment of the patient position with the preoperative MR images. In these images, the location and orientation of the coil localization unit can be inferred from a number of fiducial markers, which for this purpose have to be manually or semi-automatically detected by the user. In this study, we propose a method for precise, full-automatic localization of fiducial markers, on which basis a virtual localization unit can be subsequently placed in the image volume for the purpose of determining the parameters for needle navigation. The method is based on adaptive thresholding for separating breast tissue from background followed by rigid registration of marker templates. In an evaluation of 25 clinical cases comprising 4 different commercial coil array models and 3 different MR imaging protocols, the method yielded a sensitivity of 0.96 at a false positive rate of 0.44 markers per case. The mean distance deviation between detected fiducial centers and ground truth information that was appointed from a radiologist was 0.94mm.

  17. A Greedy Approach for Placement of Subsurface Aquifer Wells in an Ensemble Filtering Framework

    KAUST Repository

    El Gharamti, Mohamad; Marzouk, Youssef M.; Huan, Xun; Hoteit, Ibrahim

    2015-01-01

    Optimizing wells placement may help in better understanding subsurface solute transport and detecting contaminant plumes. In this work, we use the ensemble Kalman filter (EnKF) as a data assimilation tool and propose a greedy observational design algorithm to optimally select aquifer wells locations for updating the prior contaminant ensemble. The algorithm is greedy in the sense that it operates sequentially, without taking into account expected future gains. The selection criteria is based on maximizing the information gain that the EnKF carries during the update of the prior uncertainties. We test the efficiency of this algorithm in a synthetic aquifer system where a contaminant plume is set to migrate over a 30 years period across a heterogenous domain.

  18. A Greedy Approach for Placement of Subsurface Aquifer Wells in an Ensemble Filtering Framework

    KAUST Repository

    El Gharamti, Mohamad

    2015-11-26

    Optimizing wells placement may help in better understanding subsurface solute transport and detecting contaminant plumes. In this work, we use the ensemble Kalman filter (EnKF) as a data assimilation tool and propose a greedy observational design algorithm to optimally select aquifer wells locations for updating the prior contaminant ensemble. The algorithm is greedy in the sense that it operates sequentially, without taking into account expected future gains. The selection criteria is based on maximizing the information gain that the EnKF carries during the update of the prior uncertainties. We test the efficiency of this algorithm in a synthetic aquifer system where a contaminant plume is set to migrate over a 30 years period across a heterogenous domain.

  19. Internship guide : Work placements step by step

    NARCIS (Netherlands)

    Haag, Esther

    2013-01-01

    Internship Guide: Work Placements Step by Step has been written from the practical perspective of a placement coordinator. This book addresses the following questions : what problems do students encounter when they start thinking about the jobs their degree programme prepares them for? How do you

  20. Clinical placements in mental health: a literature review.

    Science.gov (United States)

    Happell, Brenda; Gaskin, Cadeyrn J; Byrne, Louise; Welch, Anthony; Gellion, Stephen

    2015-01-01

    Gaining experience in clinical mental health settings is central to the education of health practitioners. To facilitate the ongoing development of knowledge and practice in this area, we performed a review of the literature on clinical placements in mental health settings. Searches in Academic Search Complete, CINAHL, Medline and PsycINFO databases returned 244 records, of which 36 met the selection criteria for this review. Five additional papers were obtained through scanning the reference lists of those papers included from the initial search. The evidence suggests that clinical placements may have multiple benefits (e.g. improving students' skills, knowledge, attitudes towards people with mental health issues and confidence, as well as reducing their fears and anxieties about working in mental health). The location and structure of placements may affect outcomes, with mental health placements in non-mental health settings appearing to have minimal impact on key outcomes. The availability of clinical placements in mental health settings varies considerably among education providers, with some students completing their training without undertaking such structured clinical experiences. Students have generally reported that their placements in mental health settings have been positive and valuable experiences, but have raised concerns about the amount of support they received from education providers and healthcare staff. Several strategies have been shown to enhance clinical placement experiences (e.g. providing students with adequate preparation in the classroom, implementing learning contracts and providing clinical supervision). Educators and healthcare staff need to work together for the betterment of student learning and the healthcare professions.

  1. Multi-Objective Distribution Network Operation Based on Distributed Generation Optimal Placement Using New Antlion Optimizer Considering Reliability

    Directory of Open Access Journals (Sweden)

    KHANBABAZADEH Javad

    2016-10-01

    Full Text Available Distribution network designers and operators are trying to deliver electrical energy with high reliability and quality to their subscribers. Due to high losses in the distribution systems, using distributed generation can improves reliability, reduces losses and improves voltage profile of distribution network. Therefore, the choice of the location of these resources and also determining the amount of their generated power to maximize the benefits of this type of resource is an important issue which is discussed from different points of view today. In this paper, a new multi-objective optimal location and sizing of distributed generation resources is performed to maximize its benefits on the 33 bus distribution test network considering reliability and using a new Antlion Optimizer (ALO. The benefits for DG are considered as system losses reduction, system reliability improvement and benefits from the sale electricity and voltage profile improvement. For each of the mentioned benefits, the ALO algorithm is used to optimize the location and sizing of distributed generation resources. In order to verify the proposed approach, the obtained results have been analyzed and compared with the results of particle swarm optimization (PSO algorithm. The results show that the ALO has shown better performance in optimization problem solution versus PSO.

  2. Nuclear medicine markers of tumor oxygenation and radioresistance

    International Nuclear Information System (INIS)

    Chapman, J. Donald; Schneider, R.H.; Stobbe, C.C.; Kim, E.; Engelhardt, E.L.; Coia, L.

    1996-01-01

    Purpose/Objective: The objective of this research project was to synthesize, purify, radiolabel and characterize second-generation nuclear medicine markers of tissue oxygenation with properties superior to iodoazomycin arabinoside (IAZA) and to validate the hypoxia-marking activity of optimal compounds by independent measurements of tumor oxygenation and tumor radioresistance. Materials and Methods: Six hypoxic markers of the iodoazomycin nucleoside class with water solubilities greater than IAZA were synthesized by published procedures. The markers were purified, chemically characterized and labeled with Iodine-125 or Iodine-131. Absolute rates of marker ligation to the macromolecules of hypoxic EMT-6 tumor cells in vitro were determined as a function of marker concentration and used to establish relative marker effectiveness. Hypoxic marking activity in tumors was determined from tumor/blood (T/B) and tumor/muscle (T/M) ratios of radiolabelled marker in EMT-6 tumor-bearing C.B17/Icr scid mice. The optimal marker was administered to R3327-H and R3327-AT tumor-bearing Fischer X Copenhagen rats for estimates of tumor oxygenation by T/B and T/M ratios. Oxygen distributions in the same tumors were obtained with the Eppendorf pO 2 Histograph. The radioresistance of individual tumors was determined from in vitro plating efficiencies of cells released from tumors which had been irradiated in vivo with 20 Gy Cs-137 γ-rays. Results: Of the six iodinated azomycin nucleosides investigated, five were novel markers and all had water solubilities higher than IAZA. Iodinated azomycin xylopyranoside (β-D-IAZXP) was selected as the optimal marker of this class since it 1) exhibited the highest absolute rate of ligation to hypoxic tumor cells in vitro, 2) had the fastest plasma clearance rate in tumor-bearing mice and 3) yielded high T/B ratios in both the mouse and rat tumor models employed in this study. Planar nuclear medicine images of (I-131) β-D-IAZXP in tumor-bearing rats

  3. Brand Placement and Consumer Choice: An in-Store Experiment

    Science.gov (United States)

    Sigurdsson, Valdimar; Saevarsson, Hugi; Foxall, Gordon

    2009-01-01

    An in-store experiment was performed to investigate the effects of shelf placement (high, middle, low) on consumers' purchases of potato chips. Placement of potato chips on the middle shelf was associated with the highest percentage of purchases. The results confirm the importance of item placement as a factor in consumers' buying behavior.…

  4. Right ventricle/interventricular septum electrophysiological anatomy (determination of optimal right ventricular lead placement

    Directory of Open Access Journals (Sweden)

    М. В. Диденко

    2015-10-01

    Full Text Available Notwithstanding a theoretically justified lead placement into the interventricular septum (IVS, the data from the clinical trials demonstrate somewhat controversial results. One of these controversies is the absence of consolidated criteria for positioning the electrode to deliver pacing from the interventricular septum (IVS area. The study describes anatomic features of RV and IVS with respect to the cardiac conduction system, normal ventricular excitation and electrode implantation techniques for continuous pacing. A comparative study of 73 specimens of cadaver hearts was carried out by using electro-anatomic 3D mapping of the heart, X-ray examination, computer-aided tomography, morphological and morphometric investigation. It was found out that the medium part of IVS in the septomarginal trabecula zone could be considered the best for continuous pacing. The criteria for the RV lead to be implanted in this zone were determined.

  5. A Schur Method for Designing LQ-optimal Systems with Prescribed Eigenvalues

    Directory of Open Access Journals (Sweden)

    David Di Ruscio

    1990-01-01

    Full Text Available In this paper a new algorithm for solving the LQ-optimal pole placement problem is presented. The method studied is a variant of the classical eigenvector approach and instead uses a set of Schur vectors, thereby gaining substantial numerical advantages. An important task in this method is the LQ-optimal pole placement problem for a second order (sub system. The paper presents a detailed analytical solution to this problem. This part is not only important for solving the general n-dimensional problem but also provides an understanding of the behaviour of an optimal system: The paper shows that in some cases it is an infinite number; in others a finite number, and in still others, non state weighting matrices Q that give the system a set of prescribed eigenvalues. Equations are presented that uniquely determine these state weight matrices as a function of the new prescribed eigcnvalues. From this result we have been able to derive the maximum possible imaginary part of the eigenvalues in an LQ-optimal system, irrespective of how the state weight matrix is chosen.

  6. Geometric leaf placement strategies

    International Nuclear Information System (INIS)

    Fenwick, J D; Temple, S W P; Clements, R W; Lawrence, G P; Mayles, H M O; Mayles, W P M

    2004-01-01

    Geometric leaf placement strategies for multileaf collimators (MLCs) typically involve the expansion of the beam's-eye-view contour of a target by a uniform MLC margin, followed by movement of the leaves until some point on each leaf end touches the expanded contour. Film-based dose-distribution measurements have been made to determine appropriate MLC margins-characterized through an index d 90 -for multileaves set using one particular strategy to straight lines lying at various angles to the direction of leaf travel. Simple trigonometric relationships exist between different geometric leaf placement strategies and are used to generalize the results of the film work into d 90 values for several different strategies. Measured d 90 values vary both with angle and leaf placement strategy. A model has been derived that explains and describes quite well the observed variations of d 90 with angle. The d 90 angular variations of the strategies studied differ substantially, and geometric and dosimetric reasoning suggests that the best strategy is the one with the least angular variation. Using this criterion, the best straightforwardly implementable strategy studied is a 'touch circle' approach for which semicircles are imagined to be inscribed within leaf ends, the leaves being moved until the semicircles just touch the expanded target outline

  7. Comparative Performance Analysis of G-RAKE Receivers with Suboptimal Finger Placement

    Directory of Open Access Journals (Sweden)

    K. B. Baltzis

    2014-07-01

    Full Text Available Generalized RAKE (G-RAKE reception reduces the total amount of interference and provides enhanced diversity by comprising extra fingers to collect information about interference and further using channel and impairment correlation estimates for fingers allocation. However, the hardware complexity and the excessive computational requirements of GRAKE receivers may restrict their application in real systems; thus, suboptimal solutions are commonly used. In this paper, we propose and evaluate three maximum likelihood G-RAKE structures for colored noise with suboptimal finger placement. In all implementations, the fingers are optimally distributed within a time window that spans from several chip periods before the first arriving multipath to several chip periods after the latest one. The first receiver has its fingers at integer multiples of the chip period while in the rest two structures the search window is segmented in halves and tenths of the chip duration. This work also extends earlier studies by thoroughly investigating the impact of fractionally spaced finger placement on system performance. Our analysis shows that a suboptimal finger allocation reduces hardware complexity with negligible performance loss. The impact of channel delay spread and processing gain on system performance is also investigated and gives interesting results.

  8. Clitoral Pain Following Retropubic Midurethral Sling Placement

    Directory of Open Access Journals (Sweden)

    Melanie Christofferson, DO

    2015-12-01

    Conclusion: Clitoral pain symptoms following placement of a retropubic midurethral sling should be evaluated and promptly addressed, given the potential negative impact on the patient's sexual function. Christofferson M, Barnard J, and Montoya TI. Clitoral pain following retropubic midurethral sling placement. Sex Med 2015;3:346–348.

  9. A physical theory on placement of fertilizers

    NARCIS (Netherlands)

    Wit, de C.T.

    1953-01-01

    A theory was developed enabling calculation of the effect of any placement method of fertilizer on yield if the effect of one method is known.

    This theory was based on the following established facts. The reactions between soil and fertilizer rate are the same for broadcasting and placement

  10. Radiography students' perceptions of clinical placements - A Nigerian perspective

    Energy Technology Data Exchange (ETDEWEB)

    Ogbu, S.O.I. [Department of Medical Radiography and Radiological Sciences, University of Nigeria, Enugu Campus, 11 Clement Nnakwe Close, Ugbene, Abakpa-Nike, Enugu State 400001 (Nigeria)], E-mail: sylvogbu_rad@yahoo.com

    2008-05-15

    Purpose: To assess undergraduate radiography student perception of clinical placements and to evaluate their clinical learning experiences. Methods: To evaluate student perception of clinical placements, a Likert-scale questionnaire was used to assess clinical practice, the practice-learning environment. One hundred and seventy-eight undergraduate [student] radiographers participated in the study. Results: The students indicated they had adequate and enjoyed their time on the clinical placement. They also indicated the qualified staff was supportive, friendly and approachable. The students were able to achieve their learning outcomes during the placement. However placement venues, according to the students, had inadequate learning resources. No radiographic/medical imaging research findings, whether locally generated or otherwise, were used in clinical practice. Conclusions: Clinical placements had adequate student support. It provided a pleasant learning experience for the students and it enhanced their skills. Staff was willing and available to assist learning. Nevertheless, the training institutions, professional body and clinical placement providers need to make an effort to address inadequate learning resources (e.g. IT, library, study rooms) as well as the non-utilization of radiographic/medical imaging research findings.

  11. Factors influencing radiation therapy student clinical placement satisfaction

    Science.gov (United States)

    Bridge, Pete; Carmichael, Mary-Ann

    2014-01-01

    Introduction: Radiation therapy students at Queensland University of Technology (QUT) attend clinical placements at five different clinical departments with varying resources and support strategies. This study aimed to determine the relative availability and perceived importance of different factors affecting student support while on clinical placement. The purpose of the research was to inform development of future support mechanisms to enhance radiation therapy students’ experience on clinical placement. Methods: This study used anonymous Likert-style surveys to gather data from years 1 and 2 radiation therapy students from QUT and clinical educators from Queensland relating to availability and importance of support mechanisms during clinical placements in a semester. Results: The study findings demonstrated student satisfaction with clinical support and suggested that level of support on placement influenced student employment choices. Staff support was perceived as more important than physical resources; particularly access to a named mentor, a clinical educator and weekly formative feedback. Both students and educators highlighted the impact of time pressures. Conclusions: The support offered to radiation therapy students by clinical staff is more highly valued than physical resources or models of placement support. Protected time and acknowledgement of the importance of clinical education roles are both invaluable. Joint investment in mentor support by both universities and clinical departments is crucial for facilitation of effective clinical learning. PMID:26229635

  12. Factors influencing radiation therapy student clinical placement satisfaction

    Energy Technology Data Exchange (ETDEWEB)

    Bridge, Pete; Carmichael, Mary-Ann [School of Clinical Sciences, Queensland University of Technology, Brisbane (Australia)

    2014-02-15

    Introduction: Radiation therapy students at Queensland University of Technology (QUT) attend clinical placements at five different clinical departments with varying resources and support strategies. This study aimed to determine the relative availability and perceived importance of different factors affecting student support while on clinical placement. The purpose of the research was to inform development of future support mechanisms to enhance radiation therapy students’ experience on clinical placement. Methods: This study used anonymous Likert-style surveys to gather data from years 1 and 2 radiation therapy students from QUT and clinical educators from Queensland relating to availability and importance of support mechanisms during clinical placements in a semester. Results: The study findings demonstrated student satisfaction with clinical support and suggested that level of support on placement influenced student employment choices. Staff support was perceived as more important than physical resources; particularly access to a named mentor, a clinical educator and weekly formative feedback. Both students and educators highlighted the impact of time pressures. Conclusions: The support offered to radiation therapy students by clinical staff is more highly valued than physical resources or models of placement support. Protected time and acknowledgement of the importance of clinical education roles are both invaluable. Joint investment in mentor support by both universities and clinical departments is crucial for facilitation of effective clinical learning.

  13. Factors influencing radiation therapy student clinical placement satisfaction

    International Nuclear Information System (INIS)

    Bridge, Pete; Carmichael, Mary-Ann

    2014-01-01

    Introduction: Radiation therapy students at Queensland University of Technology (QUT) attend clinical placements at five different clinical departments with varying resources and support strategies. This study aimed to determine the relative availability and perceived importance of different factors affecting student support while on clinical placement. The purpose of the research was to inform development of future support mechanisms to enhance radiation therapy students’ experience on clinical placement. Methods: This study used anonymous Likert-style surveys to gather data from years 1 and 2 radiation therapy students from QUT and clinical educators from Queensland relating to availability and importance of support mechanisms during clinical placements in a semester. Results: The study findings demonstrated student satisfaction with clinical support and suggested that level of support on placement influenced student employment choices. Staff support was perceived as more important than physical resources; particularly access to a named mentor, a clinical educator and weekly formative feedback. Both students and educators highlighted the impact of time pressures. Conclusions: The support offered to radiation therapy students by clinical staff is more highly valued than physical resources or models of placement support. Protected time and acknowledgement of the importance of clinical education roles are both invaluable. Joint investment in mentor support by both universities and clinical departments is crucial for facilitation of effective clinical learning

  14. Optimal sensor configuration for complex systems

    DEFF Research Database (Denmark)

    Sadegh, Payman; Spall, J. C.

    1998-01-01

    configuration is based on maximizing the overall sensor response while minimizing the correlation among the sensor outputs. The procedure for sensor configuration is based on simultaneous perturbation stochastic approximation (SPSA). SPSA avoids the need for detailed modeling of the sensor response by simply......Considers the problem of sensor configuration for complex systems. Our approach involves definition of an appropriate optimality criterion or performance measure, and description of an efficient and practical algorithm for achieving the optimality objective. The criterion for optimal sensor...... relying on observed responses as obtained by limited experimentation with test sensor configurations. We illustrate the approach with the optimal placement of acoustic sensors for signal detection in structures. This includes both a computer simulation study for an aluminum plate, and real...

  15. optimal location of distributed generation on the nigerian power ...

    African Journals Online (AJOL)

    user

    optimal sizing and placement of DG in the Nigerian power network for active power loss minimization. The ..... costs, resulting to low or over voltage in the network contrary to the desired ... Through Capabilities of a Wind Farm” Paper ID 99,.

  16. Dispositional Optimism

    Science.gov (United States)

    Carver, Charles S.; Scheier, Michael F.

    2014-01-01

    Optimism is a cognitive construct (expectancies regarding future outcomes) that also relates to motivation: optimistic people exert effort, whereas pessimistic people disengage from effort. Study of optimism began largely in health contexts, finding positive associations between optimism and markers of better psychological and physical health. Physical health effects likely occur through differences in both health-promoting behaviors and physiological concomitants of coping. Recently, the scientific study of optimism has extended to the realm of social relations: new evidence indicates that optimists have better social connections, partly because they work harder at them. In this review, we examine the myriad ways this trait can benefit an individual, and our current understanding of the biological basis of optimism. PMID:24630971

  17. Private Placement Debt Financing for Public Entities

    Science.gov (United States)

    Holman, Lance S.

    2010-01-01

    Private placement financing is a debt or capital lease obligation arranged between a municipality or a 501(c) (3) not-for-profit organization and a single sophisticated institutional investor. The investor can be a bank, insurance company, finance company, hedge fund, or high-net worth individual. Private placement financing is similar to…

  18. Patterns of out-of-home placement decision-making in child welfare.

    Science.gov (United States)

    Chor, Ka Ho Brian; McClelland, Gary M; Weiner, Dana A; Jordan, Neil; Lyons, John S

    2013-10-01

    Out-of-home placement decision-making in child welfare is founded on the best interest of the child in the least restrictive setting. After a child is removed from home, however, little is known about the mechanism of placement decision-making. This study aims to systematically examine the patterns of out-of-home placement decisions made in a state's child welfare system by comparing two models of placement decision-making: a multidisciplinary team decision-making model and a clinically based decision support algorithm. Based on records of 7816 placement decisions representing 6096 children over a 4-year period, hierarchical log-linear modeling characterized concordance or agreement, and discordance or disagreement when comparing the two models and accounting for age-appropriate placement options. Children aged below 16 had an overall concordance rate of 55.7%, most apparent in the least restrictive (20.4%) and the most restrictive placement (18.4%). Older youth showed greater discordant distributions (62.9%). Log-linear analysis confirmed the overall robustness of concordance (odd ratios [ORs] range: 2.9-442.0), though discordance was most evident from small deviations from the decision support algorithm, such as one-level under-placement in group home (OR=5.3) and one-level over-placement in residential treatment center (OR=4.8). Concordance should be further explored using child-level clinical and placement stability outcomes. Discordance might be explained by dynamic factors such as availability of placements, caregiver preferences, or policy changes and could be justified by positive child-level outcomes. Empirical placement decision-making is critical to a child's journey in child welfare and should be continuously improved to effect positive child welfare outcomes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Visibility of fiducial markers used for image-guided radiation therapy on optical coherence tomography for registration with CT: An esophageal phantom study.

    Science.gov (United States)

    Jelvehgaran, Pouya; Alderliesten, Tanja; Weda, Jelmer J A; de Bruin, Martijn; Faber, Dirk J; Hulshof, Maarten C C M; van Leeuwen, Ton G; van Herk, Marcel; de Boer, Johannes F

    2017-12-01

    Optical coherence tomography (OCT) is of interest to visualize microscopic esophageal tumor extensions to improve tumor delineation for radiation therapy (RT) planning. Fiducial marker placement is a common method to ensure target localization during planning and treatment. Visualization of these fiducial markers on OCT permits integrating OCT and computed tomography (CT) images used for RT planning via image registration. We studied the visibility of 13 (eight types) commercially available solid and liquid fiducial markers in OCT images at different depths using dedicated esophageal phantoms and evaluated marker placement depth in clinical practice. We designed and fabricated dedicated esophageal phantoms, in which three layers mimic the anatomical wall structures of a healthy human esophagus. We successfully implanted 13 commercially available fiducial markers that varied in diameter and material property at depths between 0.5 and 3.0 mm. The resulting esophageal phantoms were imaged with OCT, and marker visibility was assessed qualitatively and quantitatively using the contrast-to-background-noise ratio (CNR). The CNR was defined as the difference between the mean intensity of the fiducial markers and the mean intensity of the background divided by the standard deviation of the background intensity. To determine whether, in current clinical practice, the implanted fiducial markers are within the OCT visualization range (up to 3.0 mm depth), we retrospectively measured the distance of 19 fiducial markers to the esophageal lumen on CT scans of 16 esophageal cancer patients. In the esophageal phantoms, all the included fiducial markers were visible on OCT at all investigated depths. Solid fiducial markers were better visible on OCT than liquid fiducial markers with a 1.74-fold higher CNR. Although fiducial marker identification per type and size was slightly easier for superficially implanted fiducial markers, we observed no difference in the ability of OCT to

  20. Disclosing brand placement to young children

    OpenAIRE

    De Pauw, Pieter; Hudders, Liselot; Cauberghe, Veroline; De Kuysscher, Charlotte

    2015-01-01

    Purpose – This article examines whether a television brand placement warning cue can alter young children’s susceptibility for advertising effects (i.e., brand attitude) through activating their advertising literacy. The proposed model also puts forward an important moderating role for children’s skeptical attitude toward the brand placement format. Design/methodology/approach – The data were collected among 63 children between 7 and 9 years old (Mage = 8.49; 51% girls) through a single...

  1. Laryngeal mask placement in a teaching institution: analysis of difficult placements [version 1; referees: 2 approved, 1 approved with reservations

    Directory of Open Access Journals (Sweden)

    Anastasia D Katsiampoura

    2015-04-01

    Full Text Available Background: Laryngeal mask airway (LMA placement is now considered a common airway management practice. Although there are many studies which focus on various airway techniques, research regarding difficult LMA placement is limited, particularly for anesthesiologist trainees. In our retrospective analysis we tried to identify predictive factors of difficult LMA placement in an academic training program. Methods: This retrospective analysis was derived from a research airway database, where data were collected prospectively at the Memorial Hermann Hospital, Texas Medical Center, Houston, TX, USA, from 2008 to 2010. All non-obstetric adult patients presenting for elective surgery requiring general anesthesia, were enrolled in this study: anesthesiology residents primarily managed the airways. The level of difficulty, number of attempts, and type of the extraglottic device placement were retrieved. Results: Sixty-nine unique Laryngeal Mask Airways (uLMAs were utilized as a primary airway device. Two independent predictors for difficult LMA placement were identified: gender and neck circumference. The sensitivity for one factor is 87.5% with a specificity of 50%. However with two risk factors, the specificity increases to the level of 93% and the sensitivity is 63%. Conclusion: In a large academic training program, besides uLMA not been used routinely, two risk factors for LMA difficulty were identified, female gender and large neck circumference. Neck circumference is increasingly being recognized as a significant predictor across the spectrum of airway management difficulties while female gender has not been previously reported as a risk factor for difficult LMA placement.

  2. 33 CFR 183.566 - Fuel pumps: Placement.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Fuel pumps: Placement. 183.566...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Manufacturer Requirements § 183.566 Fuel pumps: Placement. Each fuel pump must be on the engine it serves or within 12 inches of the engine, unless it is a...

  3. Impact of Antenna Placement on Frequency Domain Adaptive Antenna Array in Hybrid FRF Cellular System

    Directory of Open Access Journals (Sweden)

    Sri Maldia Hari Asti

    2012-01-01

    Full Text Available Frequency domain adaptive antenna array (FDAAA is an effective method to suppress interference caused by frequency selective fading and multiple-access interference (MAI in single-carrier (SC transmission. However, the performance of FDAAA receiver will be affected by the antenna placement parameters such as antenna separation and spread of angle of arrival (AOA. On the other hand, hybrid frequency reuse can be adopted in cellular system to improve the cellular capacity. However, optimal frequency reuse factor (FRF depends on the channel propagation and transceiver scheme as well. In this paper, we analyze the impact of antenna separation and AOA spread on FDAAA receiver and optimize the cellular capacity by using hybrid FRF.

  4. The Re-Placement Test: Using TOEFL for Purposes of Placement

    Science.gov (United States)

    Moglen, Daniel

    2015-01-01

    This article will consider using TOEFL scores for purposes of placement and advising for international graduate students at a northern California research university. As the number of international students is on the rise and the funds for the graduate ESL program are diminishing, the way in which the university is handling the influx of…

  5. Wave Manipulation by Topology Optimization

    DEFF Research Database (Denmark)

    Andkjær, Jacob Anders

    topology optimization can be used to design structures for manipulation of the electromagnetic and acoustic waves. The wave problems considered here fall within three classes. The first class concerns the design of cloaks, which when wrapped around an object will render the object undetectable...... for the cloak is to delay the waves in regions of higher permittivity than the background and subsequently phase match them to the waves outside. Directional acoustic cloaks can also be designed using the topology optimization method. Aluminum cylinders constitutes the design and their placement and size...... concerns the design of planar Fresnel zone plate lenses for focusing electromagnetic waves. The topology optimized zone plates improve the focusing performance compared to results known from the literature....

  6. A compensatory approach to optimal selection with mastery scores

    NARCIS (Netherlands)

    van der Linden, Willem J.; Vos, Hendrik J.

    1994-01-01

    This paper presents some Bayesian theories of simultaneous optimization of decision rules for test-based decisions. Simultaneous decision making arises when an institution has to make a series of selection, placement, or mastery decisions with respect to subjects from a population. An obvious

  7. Improvement in Interobserver Accuracy in Delineation of the Lumpectomy Cavity Using Fiducial Markers

    International Nuclear Information System (INIS)

    Shaikh, Talha; Chen Ting; Khan, Atif; Yue, Ning J.; Kearney, Thomas; Cohler, Alan; Haffty, Bruce G.; Goyal, Sharad

    2010-01-01

    Purpose: To determine, whether the presence of gold fiducial markers would improve the inter- and intraphysician accuracy in the delineation of the surgical cavity compared with a matched group of patients who did not receive gold fiducial markers in the setting of accelerated partial-breast irradiation (APBI). Methods and Materials: Planning CT images of 22 lumpectomy cavities were reviewed in a cohort of 22 patients; 11 patients received four to six gold fiducial markers placed at the time of surgery. Three physicians categorized the seroma cavity according to cavity visualization score criteria and delineated each of the 22 seroma cavities and the clinical target volume. Distance between centers of mass, percentage overlap, and average surface distance for all patients were assessed. Results: The mean seroma volume was 36.9 cm 3 and 34.2 cm 3 for fiducial patients and non-fiducial patients, respectively (p = ns). Fiducial markers improved the mean cavity visualization score, to 3.6 ± 1.0 from 2.5 ± 1.3 (p < 0.05). The mean distance between centers of mass, average surface distance, and percentage overlap for the seroma and clinical target volume were significantly improved in the fiducial marker patients as compared with the non-fiducial marker patients (p < 0.001). Conclusions: The placement of gold fiducial markers placed at the time of lumpectomy improves interphysician identification and delineation of the seroma cavity and clinical target volume. This has implications in radiotherapy treatment planning for accelerated partial-breast irradiation and for boost after whole-breast irradiation.

  8. Middle finger length-based tracheal intubation depth improves the rate of appropriate tube placement in children.

    Science.gov (United States)

    Zhou, Qing-he; Xiao, Wang-pin; Zhou, Hong-mei

    2015-11-01

    It is challenging for anesthetists to determine the optimal tracheal intubation depth in children. We hypothesize that a measure three times the length of the middle finger can be used for predicting tracheal tube depth in children. Eighty-six children (4-14 years of age) were included in this study. After the children were anesthetized, a fiberoptic bronchoscope (FOB) was inserted into the trachea, the lengths from the upper incisor teeth to carina and vocal cords were measured, and a suitably sized cuffed tracheal tube was inserted into the trachea. Age-based and middle finger length-based formulas were used to determine the tracheal intubation depth. All 86 children enrolled were included in this study. Compared with the age-based intubation, the rate of appropriate tube placement was higher for middle finger length-based intubation (88.37% vs 66.28%, P = 0.001). The proximal intubation rate was lower in middle finger length-based intubation (4.65% vs 32.56%, P tube depth was larger than that between age and optimal tracheal tube depth (0.883 vs 0.845). Our data indicate that the appropriate tube placement rate can be improved by using three times the middle finger length as the tracheal intubation depth in children. © 2015 John Wiley & Sons Ltd.

  9. The Effect of Product Placement Marketing on Effectiveness of Internet Advertising

    Science.gov (United States)

    Liao, Hsiu-Li; Liu, Su-Houn; Pi, Shih-Ming; Chen, Hui-Ju

    Compared to the traditional way of doing advertising, such as ad Banners, internet product placement is now emerging as a promising strategy for advertisers to do their job effectively in this Web 2.0 era. Therefore, this study focuses on the effectiveness of product placement advertising on the Internet. The results show that product prominence (Subtle or Prominent) and presentation of the advertising (Video or Images) significantly impacts the effectiveness of product placement advertising on the Internet, including brand impression, advertising attitude, and intention to click. Product prominence and presentation of the advertisement have an interactive impact. Our findings indicated that presenting the product through videos will enhance higher levels of advertising attitude, brand impression, and intention to click than presenting it through still images. Subtle placements will increase the level of advertising attitude and intention to click more so than prominent placements. But prominent placements increase the brand impression more than the subtle placements.

  10. Visibility and artifacts of gold fiducial markers used for image guided radiation therapy of pancreatic cancer on MRI

    International Nuclear Information System (INIS)

    Gurney-Champion, Oliver J.; Lens, Eelco; Horst, Astrid van der; Houweling, Antonetta C.; Tienhoven, Geertjan van; Bel, Arjan; Klaassen, Remy; Hooft, Jeanin E. van; Stoker, Jaap; Nederveen, Aart J.

    2015-01-01

    Purpose: In radiation therapy of pancreatic cancer, tumor alignment prior to each treatment fraction is improved when intratumoral gold fiducial markers (from here onwards: markers), which are visible on computed tomography (CT) and cone beam CT, are used. Visibility of these markers on magnetic resonance imaging (MRI) might improve image registration between CT and magnetic resonance (MR) images for tumor delineation purposes. However, concomitant image artifacts induced by markers are undesirable. The extent of visibility and artifact size depend on MRI-sequence parameters. The authors’ goal was to determine for various markers their potential to be visible and to generate artifacts, using measures that are independent of the MRI-sequence parameters. Methods: The authors selected ten different markers suitable for endoscopic placement in the pancreas and placed them into a phantom. The markers varied in diameter (0.28–0.6 mm), shape, and iron content (0%–0.5%). For each marker, the authors calculated T 2 ∗ -maps and ΔB 0 -maps using MRI measurements. A decrease in relaxation time T 2 ∗ can cause signal voids, associated with visibility, while a change in the magnetic field B 0 can cause signal shifts, which are associated with artifacts. These shifts inhibit accurate tumor delineation. As a measure for potential visibility, the authors used the volume of low T 2 ∗ , i.e., the volume for which T 2 ∗ differed from the background by >15 ms. As a measure for potential artifacts, the authors used the volume for which |ΔB 0 | > 9.4 × 10 −8 T (4 Hz). To test whether there is a correlation between visibility and artifact size, the authors calculated the Spearman’s correlation coefficient (R s ) between the volume of low T 2 ∗ and the volume of high |ΔB 0 |. The authors compared the maps with images obtained using a clinical MR-sequence. Finally, for the best visible marker as well as the marker that showed the smallest artifact, the authors

  11. This is Advertising! Effects of Disclosing Television Brand Placement on Adolescents.

    Science.gov (United States)

    van Reijmersdal, Eva A; Boerman, Sophie C; Buijzen, Moniek; Rozendaal, Esther

    2017-02-01

    As heavy media users, adolescents are frequently exposed to embedded advertising formats such as brand placements. Because this may lead to unwitting persuasion, regulations prescribe disclosure of brand placements. This study aimed to increase our understanding of the effects of disclosing television brand placements and disclosure duration on adolescents' persuasion knowledge (i.e., recognition of brand placement as being advertising, understanding that brand placement has a persuasive intent and critical attitude toward brand placement) and brand responses (i.e., brand memory and brand attitude). To do so, an earlier study that was conducted among adults was replicated among adolescents aged 13-17 years (N = 221, 44 % female). The present study shows that brand placement disclosure had limited effects on adolescents' persuasion knowledge as it only affected adolescents' understanding of persuasive intent, did not mitigate persuasion, but did increase brand memory. These findings suggest that brand placement disclosure has fundamentally different effects on adolescents than on adults: the disclosures had less effects on activating persuasion knowledge and mitigating persuasion among adolescents than among adults. Implications for advertising disclosure regulation and consequences for advertisers are discussed.

  12. Emerging: An Art Field Placement's Impact on Practice

    Science.gov (United States)

    Averett, Paige; Spence, Christina Hall

    2018-01-01

    This exploratory study examined the experiences of 9 stakeholders in an art gallery field placement during their social work education. The study sought to understand how the nontraditional field placement prepared students for practice. In addition, personality traits of students that best fit the placement was examined. Findings suggest that…

  13. Photovoltaic and Wind Turbine Integration Applying Cuckoo Search for Probabilistic Reliable Optimal Placement

    OpenAIRE

    R. A. Swief; T. S. Abdel-Salam; Noha H. El-Amary

    2018-01-01

    This paper presents an efficient Cuckoo Search Optimization technique to improve the reliability of electrical power systems. Various reliability objective indices such as Energy Not Supplied, System Average Interruption Frequency Index, System Average Interruption, and Duration Index are the main indices indicating reliability. The Cuckoo Search Optimization (CSO) technique is applied to optimally place the protection devices, install the distributed generators, and to determine the size of ...

  14. Structural challenges of holiday placement programmes for children ...

    African Journals Online (AJOL)

    Structural challenges of holiday placement programmes for children in SOS's Children Village, Zimbabwe. ... African Journal of Social Work ... Response to child protection crisis has essentially seen the placement of orphans and other vulnerable children in residential care institutions, particularly children' homes modelled ...

  15. Promise and pitfalls of molecular markers of thyroid nodules

    Science.gov (United States)

    Jadhav, S.; Lila, Anurag; Bandgar, Tushar; Shah, Nalini

    2012-01-01

    Thyroid nodules are common in the general population with a prevalence of 5-7% The initial evaluation of thyroid nodules commonly involves thyroid function tests, an ultrasound (USG) and fine needle aspiration biopsy (FNAB). The optimal management of patients with thyroid nodules with indeterminate cytology is plagued by the lack of highly sensitive and specific diagnostic modalities In this article we attempt to review the available literature on the molecular markers which are increasingly being studied for their diagnostic utility in assessing thyroid nodules. The various molecular markers consist of gene mutations, gene re arrangements, RNA based assays and immunohistochemical markers. The molecular markers definitely would help to optimise the management of such patients. PMID:23565369

  16. Promise and pitfalls of molecular markers of thyroid nodules

    Directory of Open Access Journals (Sweden)

    S Jadhav

    2012-01-01

    Full Text Available Thyroid nodules are common in the general population with a prevalence of 5-7% The initial evaluation of thyroid nodules commonly involves thyroid function tests, an ultrasound (USG and fine needle aspiration biopsy (FNAB. The optimal management of patients with thyroid nodules with indeterminate cytology is plagued by the lack of highly sensitive and specific diagnostic modalities In this article we attempt to review the available literature on the molecular markers which are increasingly being studied for their diagnostic utility in assessing thyroid nodules. The various molecular markers consist of gene mutations, gene re arrangements, RNA based assays and immunohistochemical markers. The molecular markers definitely would help to optimise the management of such patients.

  17. ESL Placement and Schools: Effects on Immigrant Achievement.

    Science.gov (United States)

    Callahan, Rebecca; Wilkinson, Lindsey; Muller, Chandra; Frisco, Michelle

    2009-05-01

    In this study, the authors explore English as a Second Language (ESL) placement as a measure of how schools label and process immigrant students. Using propensity score matching and data from the Adolescent Health and Academic Achievement Study and the National Longitudinal Study of Adolescent Health, the authors estimate the effect of ESL placement on immigrant achievement. In schools with more immigrant students, the authors find that ESL placement results in higher levels of academic performance; in schools with few immigrant students, the effect reverses. This is not to suggest a one-size-fits-all policy; many immigrant students, regardless of school composition, generational status, or ESL placement, struggle to achieve at levels sufficient for acceptance to a 4-year university. This study offers several factors to be taken into consideration as schools develop policies and practices to provide immigrant students opportunities to learn.

  18. Rotation placements help students' understanding of intensive care.

    Science.gov (United States)

    Abbott, Lisa

    2011-07-01

    It is vital that children's nursing students are fit for practice when they qualify and are able to meet various essential skills as defined by the Nursing and Midwifery Council (NMC). To gain the knowledge and skills required, students need placements in areas where high dependency and potentially intensive care are delivered. Efforts to maximise the number of students experiencing intensive care as a placement have led to the development of the paediatric intensive care unit (PICU) rotation, increasing placements on the PICU from 5 to 40 per cent of the student cohort per year. The lecturer practitioner organises the rotation, providing credible links between university and practice areas, while supporting students and staff in offering a high-quality placement experience. Students say the rotation offers a positive insight into PICU nursing, helping them develop knowledge and skills in a technical area and creating an interest in this specialty.

  19. Dense, shape-optimized posterior 32-channel coil for submillimeter functional imaging of visual cortex at 3T.

    Science.gov (United States)

    Farivar, Reza; Grigorov, Filip; van der Kouwe, Andre J; Wald, Lawrence L; Keil, Boris

    2016-07-01

    Functional neuroimaging of small cortical patches such as columns is essential for testing computational models of vision, but imaging from cortical columns at conventional 3T fields is exceedingly difficult. By targeting the visual cortex exclusively, we tested whether combined optimization of shape, coil placement, and electronics would yield the necessary gains in signal-to-noise ratio (SNR) for submillimeter visual cortex functional MRI (fMRI). We optimized the shape of the housing to a population-averaged atlas. The shape was comfortable without cushions and resulted in the maximally proximal placement of the coil elements. By using small wire loops with the least number of solder joints, we were able to maximize the Q factor of the individual elements. Finally, by planning the placement of the coils using the brain atlas, we were able to target the arrangement of the coil elements to the extent of the visual cortex. The combined optimizations led to as much as two-fold SNR gain compared with a whole-head 32-channel coil. This gain was reflected in temporal SNR as well and enabled fMRI mapping at 0.75 mm resolutions using a conventional GRAPPA-accelerated gradient echo echo planar imaging. Integrated optimization of shape, electronics, and element placement can lead to large gains in SNR and empower submillimeter fMRI at 3T. Magn Reson Med 76:321-328, 2016. © 2015 Wiley Periodicals, Inc. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

  20. Optimized packings with applications

    CERN Document Server

    Pintér, János

    2015-01-01

    This volume presents a selection of case studies that address a substantial range of optimized object packings (OOP) and their applications. The contributing authors are well-recognized researchers and practitioners. The mathematical modelling and numerical solution aspects of each application case study are presented in sufficient detail. A broad range of OOP problems are discussed: these include various specific and non-standard container loading and object packing problems, as well as the stowing of hazardous and other materials on container ships, data centre resource management, automotive engineering design, space station logistic support, cutting and packing problems with placement constraints, the optimal design of LED street lighting, robust sensor deployment strategies, spatial scheduling problems, and graph coloring models and metaheuristics for packing applications. Novel points of view related to model development and to computational nonlinear, global, mixed integer optimization and heuristic st...

  1. A Comparative Study of Genetic and Firefly Algorithms for Sensor Placement in Structural Health Monitoring

    Directory of Open Access Journals (Sweden)

    Guang-Dong Zhou

    2015-01-01

    Full Text Available Optimal sensor placement (OSP is an important task during the implementation of sophisticated structural health monitoring (SHM systems for large-scale structures. In this paper, a comparative study between the genetic algorithm (GA and the firefly algorithm (FA in solving the OSP problem is conducted. To overcome the drawback related to the inapplicability of the FA in optimization problems with discrete variables, some improvements are proposed, including the one-dimensional binary coding system, the Hamming distance between any two fireflies, and the semioriented movement scheme; also, a simple discrete firefly algorithm (SDFA is developed. The capabilities of the SDFA and the GA in finding the optimal sensor locations are evaluated using two disparate objective functions in a numerical example with a long-span benchmark cable-stayed bridge. The results show that the developed SDFA can find the optimal sensor configuration with high reliability. The comparative study indicates that the SDFA outperforms the GA in terms of algorithm complexity, computational efficiency, and result quality. The optimization mechanism of the FA has the potential to be extended to a wide range of optimization problems.

  2. Delay of surgery after stent placement for resectable malignant colorectal obstruction is associated with higher risk of recurrence

    DEFF Research Database (Denmark)

    Broholm, Malene; Kobborg, Martin; Frostberg, Erik

    2017-01-01

    BACKGROUND: Self-expanding metal stents can be used as bridge to elective surgery for acute malignant colonic obstruction. However, the impact on long-term oncological outcome and the optimal timing of surgery are still unknown. METHOD: This was a retrospective multicenter study performed at four...... colorectal centers. Patients undergoing stent placement as bridge to surgery, between January 2010 and December 2013, were included in the study. Primary outcomes were survival and recurrence rates along with location of the metastases. Additionally, we recorded time from stent placement to elective surgery....... Secondary outcomes were postoperative complication rates. Complications were classified according to the Clavien-Dindo classification score. A logistic regression model was used to describe impact of delayed stent removal on risk of recurrence. RESULTS: This study included 112 patients, with a median follow...

  3. Study protocol: precision of a protocol for manual intramuscular needle placement checked by passive stretching and relaxing of the target muscle in the lower extremity during BTX-A treatment in children with spastic cerebral palsy, as verified by means of electrical stimulation

    NARCIS (Netherlands)

    Warnink-Kavelaars, Jessica; Vermeulen, Roland Jeroen; Becher, Jules Guilhelmus

    2013-01-01

    Background: Intramuscular injection of botulinum toxin type-A given by manual intramuscular needle placement in the lower extremity under general anaesthesia is an established treatment and standard of care in managing spasticity in children with spastic cerebral palsy. Optimal needle placement is

  4. Optimal Solution for VLSI Physical Design Automation Using Hybrid Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    I. Hameem Shanavas

    2014-01-01

    Full Text Available In Optimization of VLSI Physical Design, area minimization and interconnect length minimization is an important objective in physical design automation of very large scale integration chips. The objective of minimizing the area and interconnect length would scale down the size of integrated chips. To meet the above objective, it is necessary to find an optimal solution for physical design components like partitioning, floorplanning, placement, and routing. This work helps to perform the optimization of the benchmark circuits with the above said components of physical design using hierarchical approach of evolutionary algorithms. The goal of minimizing the delay in partitioning, minimizing the silicon area in floorplanning, minimizing the layout area in placement, minimizing the wirelength in routing has indefinite influence on other criteria like power, clock, speed, cost, and so forth. Hybrid evolutionary algorithm is applied on each of its phases to achieve the objective. Because evolutionary algorithm that includes one or many local search steps within its evolutionary cycles to obtain the minimization of area and interconnect length. This approach combines a hierarchical design like genetic algorithm and simulated annealing to attain the objective. This hybrid approach can quickly produce optimal solutions for the popular benchmarks.

  5. Determining the brand awareness of product placement in video games

    OpenAIRE

    Král, Marek

    2015-01-01

    This bachelor thesis focusses on the determination of the brand awareness of product placement in video games. The theoretical part includes information about marketing, product placement and video games. The practical part consists of evaluation of the market research about product placements in video games. Conclusion suggests the most important factors influencing the level brand awareness.

  6. The Placement Handbook. A Guide for the Competitive Employment of the Handicapped.

    Science.gov (United States)

    Horn, Adelaide; Drury, Stephen

    This handbook stresses those components that are considered peripheral to the placement process but that must precede the actual placement. The philosophy of placement upon which this guide is based appears first. Discussions follow of the basic components of the process of training and placement of handicapped individuals, including a varied…

  7. 25 CFR 26.4 - Who administers the Job Placement and Training Program?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Who administers the Job Placement and Training Program... PLACEMENT AND TRAINING PROGRAM General Applicability § 26.4 Who administers the Job Placement and Training Program? The Job Placement and Training Program is administered by the Bureau of Indian Affairs or a...

  8. Placement Design of Changeable Message Signs on Curved Roadways

    Directory of Open Access Journals (Sweden)

    Zhongren Wang, Ph.D. P.E. T.E.

    2015-01-01

    Full Text Available This paper presented a fundamental framework for Changeable Message Sign (CMS placement design along roadways with horizontal curves. This analytical framework determines the available distance for motorists to read and react to CMS messages based on CMS character height, driver's cone of vision, CMS pixel's cone of legibility, roadway horizontal curve radius, and CMS lateral and vertical placement. Sample design charts were developed to illustrate how the analytical framework may facilitate CMS placement design.

  9. FtsZ placement in nucleoid-free bacteria.

    Directory of Open Access Journals (Sweden)

    Manuel Pazos

    Full Text Available We describe the placement of the cytoplasmic FtsZ protein, an essential component of the division septum, in nucleoid-free Escherichia coli maxicells. The absence of the nucleoid is accompanied in maxicells by degradation of the SlmA protein. This protein, together with the nucleoid, prevents the placement of the septum in the regions occupied by the chromosome by a mechanism called nucleoid occlusion (NO. A second septum placement mechanism, the MinCDE system (Min involving a pole-to-pole oscillation of three proteins, nonetheless remains active in maxicells. Both Min and NO act on the polymerization of FtsZ, preventing its assembly into an FtsZ-ring except at midcell. Our results show that even in the total absence of NO, Min oscillations can direct placement of FtsZ in maxicells. Deletion of the FtsZ carboxyl terminal domain (FtsZ*, a central hub that receives signals from a variety of proteins including MinC, FtsA and ZipA, produces a Min-insensitive form of FtsZ unable to interact with the membrane-anchoring FtsA and ZipA proteins. This protein produces a totally disorganized pattern of FtsZ localization inside the maxicell cytoplasm. In contrast, FtsZ*-VM, an artificially cytoplasmic membrane-anchored variant of FtsZ*, forms helical or repetitive ring structures distributed along the entire length of maxicells even in the absence of NO. These results show that membrane anchoring is needed to organize FtsZ into rings and underscore the role of the C-terminal hub of FtsZ for their correct placement.

  10. FtsZ placement in nucleoid-free bacteria.

    Science.gov (United States)

    Pazos, Manuel; Casanova, Mercedes; Palacios, Pilar; Margolin, William; Natale, Paolo; Vicente, Miguel

    2014-01-01

    We describe the placement of the cytoplasmic FtsZ protein, an essential component of the division septum, in nucleoid-free Escherichia coli maxicells. The absence of the nucleoid is accompanied in maxicells by degradation of the SlmA protein. This protein, together with the nucleoid, prevents the placement of the septum in the regions occupied by the chromosome by a mechanism called nucleoid occlusion (NO). A second septum placement mechanism, the MinCDE system (Min) involving a pole-to-pole oscillation of three proteins, nonetheless remains active in maxicells. Both Min and NO act on the polymerization of FtsZ, preventing its assembly into an FtsZ-ring except at midcell. Our results show that even in the total absence of NO, Min oscillations can direct placement of FtsZ in maxicells. Deletion of the FtsZ carboxyl terminal domain (FtsZ*), a central hub that receives signals from a variety of proteins including MinC, FtsA and ZipA, produces a Min-insensitive form of FtsZ unable to interact with the membrane-anchoring FtsA and ZipA proteins. This protein produces a totally disorganized pattern of FtsZ localization inside the maxicell cytoplasm. In contrast, FtsZ*-VM, an artificially cytoplasmic membrane-anchored variant of FtsZ*, forms helical or repetitive ring structures distributed along the entire length of maxicells even in the absence of NO. These results show that membrane anchoring is needed to organize FtsZ into rings and underscore the role of the C-terminal hub of FtsZ for their correct placement.

  11. A linear programming approach for placement of applicants to academic programs

    OpenAIRE

    Kassa, Biniyam Asmare

    2013-01-01

    This paper reports a linear programming approach for placement of applicants to study programs developed and implemented at the college of Business & Economics, Bahir Dar University, Bahir Dar, Ethiopia. The approach is estimated to significantly streamline the placement decision process at the college by reducing required man hour as well as the time it takes to announce placement decisions. Compared to the previous manual system where only one or two placement criteria were considered, the ...

  12. 20 CFR 638.409 - Placement and job development.

    Science.gov (United States)

    2010-04-01

    ... Section 638.409 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR JOB CORPS... Placements in the Job Corps § 638.409 Placement and job development. The overall objective of all Job Corps... issued by the Job Corps Director. (a) The Regional Director, as contracting officer, shall contract with...

  13. Comparison of complications between pediatric peripherally inserted central catheter placement techniques

    International Nuclear Information System (INIS)

    Dasgupta, Niloy; Lungren, Matthew P.; Patel, Manish N.; Racadio, John M.; Johnson, Neil D.

    2016-01-01

    Peripherally inserted central catheter (PICC) is among the most common procedures performed in children in the hospital setting. PICC insertion can be simplified with the use of a sheathed needle as an alternative to the modified Seldinger technique. To retrospectively evaluate PICC placement for the technique used and the incidence of complications at a large pediatric tertiary care center. We retrospectively reviewed all PICC placements at a single institution over a 4-year period. We reviewed patient records for demographic data, PICC placement technique, catheter size and number of lumens, and the incidence of complications (i.e. multiple attempted puncture sites, phlebitis and vessel thrombosis). We analyzed complication rates between two placement techniques using a chi-square test. We identified 8,816 successful PICC placements, 4,749 (53.9%) in males and 4,067 (46.1%) in females. The average age of the patients for which a line was placed was 5.6 years (range 1 day to 45 years). A direct sheathed needle puncture technique was used in 8,362 (94.9%) placements and a modified Seldinger technique was used in 454 (5.1%). Complications occurred in 312 (3.7%) of direct sheathed needle puncture placements versus 17 (3.7%) of modified Seldinger placements (P = 0.99). Multiple puncture sites were required in 175 (2.1%) attempted direct sheathed needle puncture placements compared with 8 (1.7%) attempted modified Seldinger placements (P = 0.63). Phlebitis occurred in 94 (1.1%) direct sheathed needle puncture lines versus 5 (1.1%) modified Seldinger placed lines (P = 0.96). Vessel thrombosis occurred in 43 (0.5%) direct sheathed needle puncture lines versus 4 (0.9%) modified Seldinger placed lines (P = 0.30). The direct peel-away sheathed needle vessel puncture technique and the modified Seldinger technique used to place PICC lines in children have similar complication rates. (orig.)

  14. Comparison of complications between pediatric peripherally inserted central catheter placement techniques

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, Niloy; Lungren, Matthew P. [Lucile Packard Children' s Hospital Stanford, Department of Radiology, Palo Alto, CA (United States); Patel, Manish N.; Racadio, John M.; Johnson, Neil D. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

    2016-09-15

    Peripherally inserted central catheter (PICC) is among the most common procedures performed in children in the hospital setting. PICC insertion can be simplified with the use of a sheathed needle as an alternative to the modified Seldinger technique. To retrospectively evaluate PICC placement for the technique used and the incidence of complications at a large pediatric tertiary care center. We retrospectively reviewed all PICC placements at a single institution over a 4-year period. We reviewed patient records for demographic data, PICC placement technique, catheter size and number of lumens, and the incidence of complications (i.e. multiple attempted puncture sites, phlebitis and vessel thrombosis). We analyzed complication rates between two placement techniques using a chi-square test. We identified 8,816 successful PICC placements, 4,749 (53.9%) in males and 4,067 (46.1%) in females. The average age of the patients for which a line was placed was 5.6 years (range 1 day to 45 years). A direct sheathed needle puncture technique was used in 8,362 (94.9%) placements and a modified Seldinger technique was used in 454 (5.1%). Complications occurred in 312 (3.7%) of direct sheathed needle puncture placements versus 17 (3.7%) of modified Seldinger placements (P = 0.99). Multiple puncture sites were required in 175 (2.1%) attempted direct sheathed needle puncture placements compared with 8 (1.7%) attempted modified Seldinger placements (P = 0.63). Phlebitis occurred in 94 (1.1%) direct sheathed needle puncture lines versus 5 (1.1%) modified Seldinger placed lines (P = 0.96). Vessel thrombosis occurred in 43 (0.5%) direct sheathed needle puncture lines versus 4 (0.9%) modified Seldinger placed lines (P = 0.30). The direct peel-away sheathed needle vessel puncture technique and the modified Seldinger technique used to place PICC lines in children have similar complication rates. (orig.)

  15. Optimal topology of urban buildings for maximization of annual solar irradiation availability using a genetic algorithm

    International Nuclear Information System (INIS)

    Conceição António, Carlos A.; Monteiro, João Brasileiro; Afonso, Clito Félix

    2014-01-01

    An approach based on the optimal placement of buildings that favors the use of solar energy is proposed. By maximizing the area of exposure to incident solar irradiation on roofs and facades of buildings, improvements on the energy performance of the urban matrix are reached, contributing decisively to reduce dependence on other less environmentally friendly energy options. A mathematical model is proposed to optimize the annual solar irradiation availability where the placement of the buildings in urban environment favors the use of solar energy resource. Improvements on the solar energy potential of the urban grid are reached by maximizing the exposure of incident solar irradiation on roofs and facades of buildings. The proposed model considers predominant, the amount of direct solar radiation, omitting the components of the solar irradiation diffused and reflected. The dynamic interaction of buildings on exposure to sunlight is simulated aiming to evaluate the shadowing zones. The incident solar irradiation simulation and the dynamic shading model were integrated in an optimization approach implemented numerically. The search for optimal topological solutions for urban grid is based on a Genetic Algorithm. The objective is to generate optimal scenarios for the placement of buildings into the urban grid in the pre-design phase, which enhances the use of solar irradiation. - Highlights: • A mathematical model is proposed to optimize annual solar irradiation availability. • Maximization of incident solar irradiation on roofs and facades of buildings. • Dynamic interaction of buildings is simulated aiming to evaluate shadowing zones. • Search for optimal topological solutions for urban grid based on genetic algorithm. • Solutions are compared with the conventional configurations for urban grid

  16. FROM BRAND PLACEMENT TO TOURISM PRODUCT PLACEMENT. FICTION SERIES AS PROMOTIONAL SUPPORT OF SPANISH TOURISM DESTINATIONS

    Directory of Open Access Journals (Sweden)

    Noelia Araújo-Vila

    2011-12-01

    Full Text Available Every day more consumers spend much of their free time to the consumption of audiovisual series, which is reflected in the notable increase in downloads and audiences. Therefore, many sectors have decided to use audiovisual series as advertising (brand placement, being one of them the tourism sector (tourism product placement. There are many worldwide destinations that have decided to set in a fiction series, thus being viewed by thousands of spectators, which has resulted in increases in visitors. In the Spanish case is not so clear the use of this strategy, as it is analysed in this article.

  17. Identification and reproducibility of diagnostic DNA markers for tuber starch and yield optimization in a novel association mapping population of potato (Solanum tuberosum L.).

    Science.gov (United States)

    Schönhals, E M; Ortega, F; Barandalla, L; Aragones, A; Ruiz de Galarreta, J I; Liao, J-C; Sanetomo, R; Walkemeier, B; Tacke, E; Ritter, E; Gebhardt, C

    2016-04-01

    SNPs in candidate genes Pain - 1, InvCD141 (invertases), SSIV (starch synthase), StCDF1 (transcription factor), LapN (leucine aminopeptidase), and cytoplasm type are associated with potato tuber yield, starch content and/or starch yield. Tuber yield (TY), starch content (TSC), and starch yield (TSY) are complex characters of high importance for the potato crop in general and for industrial starch production in particular. DNA markers associated with superior alleles of genes that control the natural variation of TY, TSC, and TSY could increase precision and speed of breeding new cultivars optimized for potato starch production. Diagnostic DNA markers are identified by association mapping in populations of tetraploid potato varieties and advanced breeding clones. A novel association mapping population of 282 genotypes including varieties, breeding clones and Andean landraces was assembled and field evaluated in Northern Spain for TY, TSC, TSY, tuber number (TN) and tuber weight (TW). The landraces had lower mean values of TY, TW, TN, and TSY. The population was genotyped for 183 microsatellite alleles, 221 single nucleotide polymorphisms (SNPs) in fourteen candidate genes and eight known diagnostic markers for TSC and TSY. Association test statistics including kinship and population structure reproduced five known marker-trait associations of candidate genes and discovered new ones, particularly for tuber yield and starch yield. The inclusion of landraces increased the number of detected marker-trait associations. Integration of the present association mapping results with previous QTL linkage mapping studies for TY, TSC, TSY, TW, TN, and tuberization revealed some hot spots of QTL for these traits in the potato genome. The genomic positions of markers linked or associated with QTL for complex tuber traits suggest high multiplicity and genome wide distribution of the underlying genes.

  18. Mathematics Course Placement Using Holistic Measures: Possibilities for Community College Students

    Science.gov (United States)

    Ngo, Federick; Chi, W. Edward; Park, Elizabeth So Yun

    2018-01-01

    Background/Context: Most community colleges across the country use a placement test to determine students' readiness for college-level coursework, yet these tests are admittedly imperfect instruments. Researchers have documented significant problems stemming from overreliance on placement testing, including placement error and misdiagnosis of…

  19. German causative events with placement verbs

    Directory of Open Access Journals (Sweden)

    De Knop Sabine

    2016-06-01

    Full Text Available Several studies have described the semantic uses of German posture verbs, but only few have dealt with German placement verbs. The present study wants to make up for this gap. Starting from a collection of examples from the core corpora of the Digitales Wörterbuch der Deutschen Sprache (DWDS and some former studies on posture verbs, it first describes the variety of the most common German placement verbs stellen (‘to put upright’, legen (‘to lay down’, setzen (‘to set’ and stecken (‘to stick’.

  20. CATTLE FEEDER BEHAVIOR AND FEEDER CATTLE PLACEMENTS

    OpenAIRE

    Kastens, Terry L.; Schroeder, Ted C.

    1994-01-01

    Cattle feeders appear irrational when they place cattle on feed when projected profit is negative. Long futures positions appear to offer superior returns to cattle feeding investment. Cattle feeder behavior suggests that they believe a downward bias in live cattle futures persists and that cattle feeders use different expectations than the live cattle futures market price when making placement decisions. This study examines feeder cattle placement determinants, comparing performance of expec...

  1. Pregnancy Outcomes After Myomectomy With Polytetrafluoroethylene Placement

    OpenAIRE

    Eaton, Jennifer L.; Milad, Magdy P.

    2014-01-01

    Background and Objectives: The aim of this study was to report preliminary data on pregnancy outcomes after myomectomy with placement of an expanded polytetrafluoroethylene adhesion barrier membrane. Methods: In this retrospective case series, 68 women who underwent myomectomy with expanded polytetrafluoroethylene membrane placement between January 1, 2003, and December 31, 2009, were identified. Of these women, 15 subsequently had documented pregnancies and were included in the final dataset...

  2. Variability of Marker-Based Rectal Dose Evaluation in HDR Cervical Brachytherapy

    International Nuclear Information System (INIS)

    Wang Zhou; Jaggernauth, Wainwright; Malhotra, Harish K.; Podgorsak, Matthew B.

    2010-01-01

    In film-based intracavitary brachytherapy for cervical cancer, position of the rectal markers may not accurately represent the anterior rectal wall. This study was aimed at analyzing the variability of rectal dose estimation as a result of interfractional variation of marker placement. A cohort of five patients treated with multiple-fraction tandem and ovoid high-dose-rate (HDR) brachytherapy was studied. The cervical os point and the orientation of the applicators were matched among all fractional plans for each patient. Rectal points obtained from all fractions were then input into each clinical treated plan. New fractional rectal doses were obtained and a new cumulative rectal dose for each patient was calculated. The maximum interfractional variation of distances between rectal dose points and the closest source positions was 1.1 cm. The corresponding maximum variability of fractional rectal dose was 65.5%. The percentage difference in cumulative rectal dose estimation for each patient was 5.4%, 19.6%, 34.6%, 23.4%, and 13.9%, respectively. In conclusion, care should be taken when using rectal markers as reference points for estimating rectal dose in HDR cervical brachytherapy. The best estimate of true rectal dose for each fraction should be determined by the most anterior point among all fractions.

  3. ANALYTICAL MODELING OF INNOVATIVE SENSOR PLACEMENT STRATEGY FOR CORONA-BASED WIRELESS SENSOR NETWORKS

    Directory of Open Access Journals (Sweden)

    HASSAN H. EKAL

    2017-09-01

    Full Text Available Wireless Sensor Networks (WSNs applications are increasing rapidly, thanks to their broad potential in ecological monitoring, biomedical health monitoring, data gathering and many others. Imbalance energy of sensors causes significant reduction in the lifetime of the network. In many-to-one communication (corona WSNs, sensor nodes located nearby the data collector (sink forward data sensed data received from other nodes, hence, having heavier workloads. These nodes consume more energy than the others, leading to quicker energy depletion.Consequently, this results in energy hole problem, where the network becomes separate islands, which affect the lifetime of the network negatively. When this situation occurs, the sensed data will not be forwarded to the intended sink; accordingly, the network will not be able to completely fulfil its required tasks. In this paper, an effective sensors placement strategy is proposed to avoid or alleviate energy hole problem in such type of WSNs. The proposed strategy aims to improve, scale, and balance the energy consumption among sensor nodes and to maximize the network lifetime, by sustaining the network coverage and connectivity. To achieve this aim, the number of sensors should be optimized to create sub-balanced coronas in the sense of energy consumption, while satisfying the network coverage and connectivity requirements. The theoretical design and modelling of the proposed sensors placement strategy promise a considerable improvement in the lifetime of corona-based networks. The Experimental evaluation results have shown that the proposed sensors placement strategy is capable to increase the network lifetime considerably compared to conventional uniform strategy.

  4. Optimal siting of capacitors in radial distribution network using Whale Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    D.B. Prakash

    2017-12-01

    Full Text Available In present days, continuous effort is being made in bringing down the line losses of the electrical distribution networks. Therefore proper allocation of capacitors is of utmost importance because, it will help in reducing the line losses and maintaining the bus voltage. This in turn results in improving the stability and reliability of the system. In this paper Whale Optimization Algorithm (WOA is used to find optimal sizing and placement of capacitors for a typical radial distribution system. Multi objectives such as operating cost reduction and power loss minimization with inequality constraints on voltage limits are considered and the proposed algorithm is validated by applying it on standard radial systems: IEEE-34 bus and IEEE-85 bus radial distribution test systems. The results obtained are compared with those of existing algorithms. The results show that the proposed algorithm is more effective in bringing down the operating costs and in maintaining better voltage profile. Keywords: Whale Optimization Algorithm (WOA, Optimal allocation and sizing of capacitors, Power loss reduction and voltage stability improvement, Radial distribution system, Operating cost minimization

  5. Spatial Model for Determining the Optimum Placement of Logistics Centers in a Predefined Economic Area

    Directory of Open Access Journals (Sweden)

    Ramona Iulia Țarțavulea (Dieaconescu

    2016-08-01

    Full Text Available The process of globalization has stimulated the demand for logistics services at a level of speed and increased efficiency, which involves using of techniques, tools, technologies and modern models in supply chain management. The aim of this research paper is to present a model that can be used in order to achieve an optimized supply chain, associated with minimum transportation costs. The utilization of spatial modeling for determining the optimal locations for logistics centers in a predefined economic area is proposd in this paper. The principal methods used to design the model are mathematic optimization and linear programming. The output data of the model are the precise placement of one up to ten logistics centers, in terms of minimum operational costs for delivery from the optimum locations to consumer points. The results of the research indicate that by using the proposed model, an efficient supply chain that is consistent with optimization of transport can be designed, in order to streamline the delivery process and thus reduce operational costs

  6. Wavelength converter placement in optical networks with dynamic traffic

    DEFF Research Database (Denmark)

    Buron, Jakob Due; Ruepp, Sarah Renée; Wessing, Henrik

    2008-01-01

    We evaluate the connection provisioning performance of GMPLS-controlled wavelength routed networks under dynamic traffic load and using three different wavelength converter placement heuristics. Results show that a simple uniform placement heuristic matches the performance of complex heuristics...

  7. Life cycle assessment for dredged sediment placement strategies.

    Science.gov (United States)

    Bates, Matthew E; Fox-Lent, Cate; Seymour, Linda; Wender, Ben A; Linkov, Igor

    2015-04-01

    Dredging to maintain navigable waterways is important for supporting trade and economic sustainability. Dredged sediments are removed from the waterways and then must be managed in a way that meets regulatory standards and properly balances management costs and risks. Selection of a best management alternative often results in stakeholder conflict regarding tradeoffs between local environmental impacts associated with less expensive alternatives (e.g., open water placement), more expensive measures that require sediment disposal in constructed facilities far away (e.g., landfills), or beneficial uses that may be perceived as risky (e.g., beach nourishment or island creation). Current sediment-placement decisions often focus on local and immediate environmental effects from the sediment itself, ignoring a variety of distributed and long-term effects from transportation and placement activities. These extended effects have implications for climate change, resource consumption, and environmental and human health, which may be meaningful topics for many stakeholders not currently considered. Life-Cycle Assessment (LCA) provides a systematic and quantitative method for accounting for this wider range of impacts and benefits across all sediment management project stages and time horizons. This paper applies a cradle-to-use LCA to dredged-sediment placement through a comparative analysis of potential upland, open water, and containment-island placement alternatives in the Long Island Sound region of NY/CT. Results suggest that, in cases dealing with uncontaminated sediments, upland placement may be the most environmentally burdensome alternative, per ton-kilometer of placed material, due to the emissions associated with diesel fuel combustion and electricity production and consumption required for the extra handling and transportation. These results can be traded-off with the ecosystem impacts of the sediments themselves in a decision-making framework. Published by

  8. Impact of an international workplace learning placement on personal and professional development.

    Science.gov (United States)

    Davies, Kerryn; Curtin, Michael; Robson, Kristy

    2017-04-01

    Workplace learning (WPL) placements are a mandatory part of occupational therapy courses. There is some evidence that suggests WPL placements in international settings are beneficial for students' learning, and personal and professional development. The aim of this study was to explore the impact an international WPL placement in Vietnam had on the perceived personal and professional development of a group of Australian occupational therapy graduates. Interpretative phenomenological analysis was used to explore the perceptions of how participation in the Charles Sturt University School of Community Health's Vietnam placement influenced the personal and professional development of occupational therapy graduates. Individual semi-structured interviews were conducted with nine graduates who participated in the Vietnam placement when they were final year occupational therapy students. Interviews were audio-recorded, transcribed verbatim and individually analysed to identify key themes. Two major themes emerged from the analysis: becoming resourceful, resilient and confident, and becoming respectful of difference. The participants indicated that participation in the Vietnam placement had a positive impact on their personal and professional development. Participants indicated that the Vietnam placement enabled them to develop their resourcefulness, resilience, reasoning skills, cultural competence, confidence and independence, beyond what they felt would have achieved on a domestic placement. For these reason these participants found the placement a beneficial and worthwhile experience. © 2016 Occupational Therapy Australia.

  9. Heterocyst placement strategies to maximize the growth of cyanobacterial filaments

    International Nuclear Information System (INIS)

    Brown, Aidan I; Rutenberg, Andrew D

    2012-01-01

    Under conditions of limited fixed-nitrogen, some filamentous cyanobacteria develop a regular pattern of heterocyst cells that fix nitrogen for the remaining vegetative cells. We examine three different heterocyst placement strategies by quantitatively modelling filament growth while varying both external fixed-nitrogen and leakage from the filament. We find that there is an optimum heterocyst frequency which maximizes the growth rate of the filament; the optimum frequency decreases as the external fixed-nitrogen concentration increases but increases as the leakage increases. In the presence of leakage, filaments implementing a local heterocyst placement strategy grow significantly faster than filaments implementing random heterocyst placement strategies. With no extracellular fixed-nitrogen, consistent with recent experimental studies of Anabaena sp. PCC 7120, the modelled heterocyst spacing distribution using our local heterocyst placement strategy is qualitatively similar to experimentally observed patterns. As external fixed-nitrogen is increased, the spacing distribution for our local placement strategy retains the same shape, while the average spacing between heterocysts continuously increases. (paper)

  10. Clinical application of transnasal feeding tube placement under fluoroscopic guidance

    International Nuclear Information System (INIS)

    Ge Kunyuan; Ni Caifang; Liu Yizhi; Zhu Xiaoli; Zou Jianwei; Jin Yonghai; Chen Long; Sun Ge; Sun Lingfang; Zhang Dong

    2008-01-01

    Objective: To evaluate the feasibility and effectiveness of duodenal feeding tube placement under fluoroscopic guidance and its clinical application. Methods: The transnasal duodenal nutriment tubes placement under fluoroscopic guidance were performed in 59 patients from June 3th, 2003 to August 17th, 2007. The successful placement of the feeding tube was defined as that of the tube tip was fixed at or distal to the duodenojejunal junction. Results: 57 out of 59 patients were successfully managed by feeding tube placement, with primary successful rate of 96.6% (57/59). The remaining two failures were due to overdistention of the stomach and were further managed after gastrointestinal decompression thoroughly. The mean fluoroscopy time of the procedure was 17.8 minutes with no severe immediate or delayed complications. Conclusion: The transnasal duodenal nutrient feeding tube placement under fluoroscopic guidance is a safe,economic, and effective management for enteral nutrition, providing extensive clinical utilization. (authors)

  11. Successful implant placement in a Case of Florid Cemento-osseous Dysplasia: a case report and literature review.

    Science.gov (United States)

    Esfahanizadeh, Nasrin; Yousefi, Hila

    2018-02-06

    Florid cemento-osseus dysplasia (FCOD) has been described as a reactive process in which normal bone is replaced by fibrous connective tissues and cementum-like materials. Radiographically it appears as dense, lobulated masses, often occurring bilaterally with symmetric involvement. In this case report a successful implant placement has been reported in a 62-year-old Caucasian woman with a chief complaint of mandibular partial edentulous. Radiographic images showed the bilateral radio-opaque lesions in edentulous regions of mandible, and mandibular anterior teeth alike. All mandibular teeth were vital and no root resorption was detected. The findings of X-ray images were attributable to FCOD. A highly conservative step-by-step two-stage implant surgery was performed. After 6 months the implants loaded with fixed prosthesis. 2, 4,6,12 and 18 months after the surgery radiographic images were taken, which revealed an optimal functional rehabilitation and complete integration of implants. This report confirms that treating the edentulous area near the FCOD lesions could be planned, if conservative and step-by-step implant placement been considered. To the best of our knowledge, a case of FCOD with successful implant placement has not been reported previously. More studies in more patients are needed to confirm results of such a therapeutic modality.

  12. Radiological landmarks for the safe extra-capsular placement of supra-acetabular half pins for external fixation.

    Science.gov (United States)

    Lidder, Surjit; Heidari, Nima; Gänsslen, Axel; Grechenig, Wolfgang

    2013-03-01

    Low anterior external fixators are constructed by placing half pins in the dense bone tunnel of the supra-acetabular region in an anterior to posterior direction. Although the placement of these pins is extra-articular, they may still breach the hip capsule on the anterior inferior iliac spine and thus be intra-capsular. We aim to provide radiological markers for the most superior fibres of the capsule to allow safe extra-capsular pin placement within the supra-acetabular bone tunnel. Thirteen cadaveric pelves were used for this study. The supra-acetabular bone tunnel was visualised with an image intensifier. The proximal most fibres of the hip joint capsule were marked with a K-wire so that their relation to the bone tunnel could be clearly seen on the images. Once all images were acquired they were calibrated and analysed to estimate the dimensions of the supra-acetabular bone tunnel and the reflection of the hip capsule. The median height of the bone tunnel was 23.6 mm (18.9-33.2) and maximum width was 11.4 mm (7.6-16.3). The inferior margin of the bone tunnel was 6.7 mm (1.1-14.5) superior to the acetabular dome, and the most proximal fibres of the capsule were 9.3 mm (4.7-6.1) superior to the acetabular dome. The inferior portion of the tunnel was 3.7 mm (0.3-8.9) within the joint. Half pins for the construction of a pelvic external fixator should be placed in the upper half of the supra-acetabular bone corridor to minimise the risk of intra-capsular placement.

  13. Measuring the Value of Placements to Employers: A Cost-Benefit Approach

    Science.gov (United States)

    Wond, Tracey; Rambukwella, Shan

    2018-01-01

    This article explores the concept and measurement of placement value, underexplored in theory and practice to date. The article makes a theoretical contribution to the placement value discourse by examining and articulating the placement value concept. It also offers a practical contribution by exploring a piloted tool to evaluate employer…

  14. Optimal Placement of Energy Storage and Wind Power under Uncertainty

    Directory of Open Access Journals (Sweden)

    Pilar Meneses de Quevedo

    2016-07-01

    Full Text Available Due to the rapid growth in the amount of wind energy connected to distribution grids, they are exposed to higher network constraints, which poses additional challenges to system operation. Based on regulation, the system operator has the right to curtail wind energy in order to avoid any violation of system constraints. Energy storage systems (ESS are considered to be a viable solution to solve this problem. The aim of this paper is to provide the best locations of both ESS and wind power by optimizing distribution system costs taking into account network constraints and the uncertainty associated to the nature of wind, load and price. To do that, we use a mixed integer linear programming (MILP approach consisting of loss reduction, voltage improvement and minimization of generation costs. An alternative current (AC linear optimal power flow (OPF, which employs binary variables to define the location of the generation, is implemented. The proposed stochastic MILP approach has been applied to the IEEE 69-bus distribution network and the results show the performance of the model under different values of installed capacities of ESS and wind power.

  15. Reloading optimization of pressurized water reactor core with burnable absorber fuel

    International Nuclear Information System (INIS)

    Shi Xiuan; Liu Zhihong; Hu Yongming

    2008-01-01

    The reloading optimization problem of PWR with burnable absorber fuel is very difficult, and common optimization algorithms are inefficient and have bad global performance for it. Characteristic statistic algorithm (CSA) is very fit for the problem. In the past, the reloading optimization using CSA has shortcomings of separating the fuel assemblies' loading pattern (LP) optimization from burnable absorber's placement (BP) optimization. In this study, LP and BP were optimized simultaneously using CSA coupled with CYCLE2D, which is a core analysis code. The corresponding reloading coupling optimization software, CSALPBP, was developed. The 10th cycle reloading design of Daya Bay Nuclear Power Plant was optimized using CSALPBP. The results show that CSALPBP has high efficiency and excellent global performance. (authors)

  16. Joint Content Placement and Traffic Management for Cloud Mobile Video Distribution over Software-Defined Networks

    Institute of Scientific and Technical Information of China (English)

    Zhenghuan Zhang; Xiaofeng Jiang; Hongsheng Xi

    2016-01-01

    To cope with the rapid growth of mobile video,video providers have leveraged cloud technologies to deploy their mobile video service system for more cost-effective and scalable performance.The emergence of Software-Defined Networking (SDN) provides a promising solution to manage the underlying network.In this paper,we introduce an SDN-enabled cloud mobile video distribution architecture and propose a joint video placement,request dispatching and traffic management mechanism to improve user experience and reduce the system operational cost.We use a utility function to capture the two aspects of user experience:the level of satisfaction and average latency,and formulate the joint optimization problem as a mixed integer programming problem.We develop an optimal algorithm based on dual decomposition and prove its optimality.We conduct simulations to evaluate the performance of our algorithm and the results show that our strategy can effectively cut down the total cost and guarantee user experience.

  17. The developing relationship between recently placed foster infants and toddlers and their foster carers: Do demographic factors, placement characteristics and biological stress markers matter?

    NARCIS (Netherlands)

    van Andel, H.W.H.; Post, W.J.; Jansen, L.M.C.; Kamphuis, J.S.; v.d. Gaag, R.J.; Knorth, E.J.; Grietens, H.

    2015-01-01

    Background: Infants and toddlers often react to a foster family placement with avoidant behavior. Foster carers may interpret this as if the child is adapting quite well to the new family. This misunderstanding may lead to stress in the child and create a risk for an enduring relationship.

  18. Physical optimization of afterloading techniques

    International Nuclear Information System (INIS)

    Anderson, L.L.

    1985-01-01

    Physical optimization in brachytherapy refers to the process of determining the radioactive-source configuration which yields a desired dose distribution. In manually afterloaded intracavitary therapy for cervix cancer, discrete source strengths are selected iteratively to minimize the sum of squares of differences between trial and target doses. For remote afterloading with a stepping-source device, optimized (continuously variable) dwell times are obtained, either iteratively or analytically, to give least squares approximations to dose at an arbitrary number of points; in vaginal irradiation for endometrial cancer, the objective has included dose uniformity at applicator surface points in addition to a tapered contour of target dose at depth. For template-guided interstitial implants, seed placement at rectangular-grid mesh points may be least squares optimized within target volumes defined by computerized tomography; effective optimization is possible only for (uniform) seed strength high enough that the desired average peripheral dose is achieved with a significant fraction of empty seed locations. (orig.) [de

  19. Optimal Sizing and Placement of Power-to-Gas Systems in Future Active Distribution Networks

    DEFF Research Database (Denmark)

    Diaz de Cerio Mendaza, Iker; Bhattarai, Bishnu Prasad; Kouzelis, Konstantinos

    2015-01-01

    Power-to-Gas is recently attracting lots of interest as a new alternative for the regulation of renewable based power system. In cases, where the re-powering of old wind turbines threatens the normal operation of the local distribution network, this becomes especially relevant. However, the design...... -investment cost- and the technical losses in the system under study. The results obtained from the assessed test system show how such non-linear methods could help distribution system operators to obtain a fast and precise perception of what is the best way to integrate the Power-to-Gas facilities...... of medium voltage distribution networks does not normally follow a common pattern, finding a singular and very particular layouts in each case. This fact, makes the placement and dimensioning of such flexible loads a complicated task for the distribution system operator in the future. This paper describes...

  20. Joint sensor placement and power rating selection in energy harvesting wireless sensor networks

    KAUST Repository

    Bushnaq, Osama M.

    2017-11-02

    In this paper, the focus is on optimal sensor placement and power rating selection for parameter estimation in wireless sensor networks (WSNs). We take into account the amount of energy harvested by the sensing nodes, communication link quality, and the observation accuracy at the sensor level. In particular, the aim is to reconstruct the estimation parameter with minimum error at a fusion center under a system budget constraint. To achieve this goal, a subset of sensing locations is selected from a large pool of candidate sensing locations. Furthermore, the type of sensor to be placed at those locations is selected from a given set of sensor types (e.g., sensors with different power ratings). We further investigate whether it is better to install a large number of cheap sensors, a few expensive sensors or a combination of different sensor types at the optimal locations.

  1. In vivo reproducibility of robotic probe placement for an integrated US-CT image-guided radiation therapy system

    Science.gov (United States)

    Lediju Bell, Muyinatu A.; Sen, H. Tutkun; Iordachita, Iulian; Kazanzides, Peter; Wong, John

    2014-03-01

    Radiation therapy is used to treat cancer by delivering high-dose radiation to a pre-defined target volume. Ultrasound (US) has the potential to provide real-time, image-guidance of radiation therapy to identify when a target moves outside of the treatment volume (e.g. due to breathing), but the associated probe-induced tissue deformation causes local anatomical deviations from the treatment plan. If the US probe is placed to achieve similar tissue deformations in the CT images required for treatment planning, its presence causes streak artifacts that will interfere with treatment planning calculations. To overcome these challenges, we propose robot-assisted placement of a real ultrasound probe, followed by probe removal and replacement with a geometrically-identical, CT-compatible model probe. This work is the first to investigate in vivo deformation reproducibility with the proposed approach. A dog's prostate, liver, and pancreas were each implanted with three 2.38-mm spherical metallic markers, and the US probe was placed to visualize the implanted markers in each organ. The real and model probes were automatically removed and returned to the same position (i.e. position control), and CT images were acquired with each probe placement. The model probe was also removed and returned with the same normal force measured with the real US probe (i.e. force control). Marker positions in CT images were analyzed to determine reproducibility, and a corollary reproducibility study was performed on ex vivo tissue. In vivo results indicate that tissue deformations with the real probe were repeatable under position control for the prostate, liver, and pancreas, with median 3D reproducibility of 0.3 mm, 0.3 mm, and 1.6 mm, respectively, compared to 0.6 mm for the ex vivo tissue. For the prostate, the mean 3D tissue displacement errors between the real and model probes were 0.2 mm under position control and 0.6 mm under force control, which are both within acceptable

  2. Radiologic placement of metallic esophageal stents: preliminary experience

    International Nuclear Information System (INIS)

    Good, S.; Asch, M.R.; Jaffer, N.; Casson, A.G.

    1997-01-01

    To assess the usefulness of covered, self expanding metallic stents for alleviating stricture associated with malignant esophageal lesions. Patients and methods: Self-expanding metallic stents were placed in 10 patients with dysphagia related to stricture caused by malignant esophageal lesions. The stents were placed fluoroscopically with local anesthesia, and patency of the esophageal lumen was assessed by barium study after the procedure. The patients were then followed clinically. Results: In all 10 cases patency of the lumen was renewed after stent placement. After the procedure 9 of the patients could tolerate a normal or near-normal diet; in the other patient esophageal perforation occurred, and clinical deterioration prevented oral intake of food. In one patient, 2 stents were needed because of the length of the stricture. Two patients experienced reflux after placement of the stent across the gastro-esophageal junction. Another patient had asymptomatic aspiration after stent placement in the proximal esophagus. In 2 patients, symptoms associated with tracheoesophageal fistula were relieved after placement of the stents. Six of the 10 patients died; mean survival after the procedure was 12 (range 1 to 56) weeks. The other 4 patients were alive at the time of writing, having survived for a mean of 7.5 (range 2 to 13) weeks; all of these patients tolerated a near-normal diet. Conclusions: The placement of covered, self-expanding metallic stents is a quick, effective method of palliating dysphagia related to stricture caused by malignant esophageal lesions. (author)

  3. Medical school clinical placements - the optimal method for assessing the clinical educational environment from a graduate entry perspective.

    Science.gov (United States)

    Hyde, Sarah; Hannigan, Ailish; Dornan, Tim; McGrath, Deirdre

    2018-01-05

    Educational environment is a strong determinant of student satisfaction and achievement. The learning environments of medical students on clinical placements are busy workplaces, composed of many variables. There is no universally accepted method of evaluating the clinical learning environment, nor is there consensus on what concepts or aspects should be measured. The aims of this study were to compare the Dundee ready educational environment measure (DREEM - the current de facto standard) and the more recently developed Manchester clinical placement index (MCPI) for the assessment of the clinical learning environment in a graduate entry medical student cohort by correlating the scores of each and analysing free text comments. This study also explored student perceptionof how the clinical educational environment is assessed. An online, anonymous survey comprising of both the DREEM and MCPI instruments was delivered to students on clinical placement in a graduate entry medical school. Additional questions explored students' perceptions of instruments for giving feedback. Numeric variables (DREEM score, MCPI score, ratings) were tested for normality and summarised. Pearson's correlation coefficient was used to measure the strength of the association between total DREEM score and total MCPI scores. Thematic analysis was used to analyse the free text comments. The overall response rate to the questionnaire was 67% (n = 180), with a completed response rate for the MCPI of 60% (n = 161) and for the DREEM of 58% (n = 154). There was a strong, positive correlation between total DREEM and MCPI scores (r = 0.71, p < 0.001). On a scale of 0 to 7, the mean rating for how worthwhile students found completing the DREEM was 3.27 (SD 1.41) and for the MCPI was 3.49 (SD 1.57). 'Finding balance' and 'learning at work' were among the themes to emerge from analysis of free text comments. The present study confirms that DREEM and MCPI total scores are strongly correlated

  4. Hollow mandrin facilitates external ventricular drainage placement.

    Science.gov (United States)

    Heese, O; Regelsberger, J; Kehler, U; Westphal, M

    2005-07-01

    Placement of ventricular catheters is a routine procedure in neurosurgery. Ventricle puncture is done using a flexible ventricular catheter stabilised by a solid steel mandrin in order to improve stability during brain penetration. A correct catheter placement is confirmed after removing the solid steel mandrin by observation of cerebrospinal fluid (CSF) flow out of the flexible catheter. Incorrect placement makes further punctures necessary. The newly developed device allows CSF flow observation during the puncture procedure and in addition precise intracranial pressure (ICP) measurement. The developed mandrin is hollow with a blunt tip. On one side 4-5 small holes with a diameter of 0.8 mm are drilled corresponding exactly with the holes in the ventricular catheter, allowing CSF to pass into the hollow mandrin as soon as the ventricle is reached. By connecting a small translucent tube at the distal portion of the hollow mandrin ICP can be measured without loss of CSF. The system has been used in 15 patients with subarachnoid haemorrhage (SAH) or intraventricular haemeorrhage (IVH) and subsequent hydrocephalus. The new system improved the external ventricular drainage implantation procedure. In all 15 patients catheter placement was correct. ICP measurement was easy to perform immediately at ventricle puncture. In 4 patients at puncture no spontaneous CSF flow was observed, therefore by connecting a syringe and gentle aspiration of CSF correct placement was confirmed in this unexpected low pressure hydrocephalus. Otherwise by using the conventional technique further punctures would have been necessary. Advantages of the new technique are less puncture procedures with a lower risk of damage to neural structures and reduced risk of intracranial haemorrhages. Implantation of the ventricular catheter to far into the brain can be monitored and this complication can be overcome. Using the connected pressure monitoring tube an exact measurement of the opening

  5. A Cloud-Computing-Based Data Placement Strategy in High-Speed Railway

    Directory of Open Access Journals (Sweden)

    Hanning Wang

    2012-01-01

    Full Text Available As an important component of China’s transportation data sharing system, high-speed railway data sharing is a typical application of data-intensive computing. Currently, most high-speed railway data is shared in cloud computing environment. Thus, there is an urgent need for an effective cloud-computing-based data placement strategy in high-speed railway. In this paper, a new data placement strategy named hierarchical structure data placement strategy is proposed. The proposed method combines the semidefinite programming algorithm with the dynamic interval mapping algorithm. The semi-definite programming algorithm is suitable for the placement of files with various replications, ensuring that different replications of a file are placed on different storage devices, while the dynamic interval mapping algorithm ensures better self-adaptability of the data storage system. A hierarchical data placement strategy is proposed for large-scale networks. In this paper, a new theoretical analysis is provided, which is put in comparison with several other previous data placement approaches, showing the efficacy of the new analysis in several experiments.

  6. 26 CFR 31.3506-1 - Companion sitting placement services.

    Science.gov (United States)

    2010-04-01

    ....3506-1 Companion sitting placement services. (a) Definitions—(1) Companion sitting placement service... agency that places babysitters with individuals who desire babysitting services. X furnishes all the.... B performs the services four days a week in A's home and follows specific instructions given by A...

  7. Research advances in tumor markers for the diagnosis of hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    YANG Guimin

    2018-01-01

    Full Text Available Hepatocellular carcinoma (HCC is a malignant tumor with a high fatality rate in the world, and alpha-fetoprotein (AFP is the most commonly used tumor marker for HCC diagnosis. However, AFP does not have a satisfactory sensitivity or specificity and may lead to missed diagnosis when the tumor is small in the early stage of HCC. This article summarizes the clinical value of new tumor markers in the diagnosis, treatment monitoring, and prognosis judgment of HCC and analyzes the future prospects of the measurement of tumor markers for HCC. It is pointed out that combined determination of several tumor markers helps to improve the sensitivity and specificity of HCC diagnosis, and the screening and optimization of combined determination of tumor markers, noninvasive and efficient tumor markers, and individualized treatment are research hotspots in future.

  8. Practical solid and liquid phase markers for studying gastric emptying in man

    International Nuclear Information System (INIS)

    Thomforde, G.M.; Brown, M.L.; Malagelada, J.R.

    1985-01-01

    This paper presents a method used to evaluate solid and liquid phase markers for radionuclide gastric emptying studies. The authors conducted in vitro and in vivo comparative experiments employing several radiolabeled markers. Among the solid phase markers tested, Tc-99m-sulfur colloid in vivo-labeled liver and I-131-fiber performed optimally. However, Tc-99M sulfur colloid in scrambled egg showed very acceptable performance and it is significantly easier to prepare. Among liquid phase markers, they found In-111-DTPA stabilized with 1% albumin to be a good agent and appropriate for dual isotope emptying studies

  9. Effect of electromagnetic navigated ventriculoperitoneal shunt placement on failure rates.

    Science.gov (United States)

    Jung, Nayoung; Kim, Dongwon

    2013-03-01

    To evaluate the effect of electromagnetic (EM) navigation system on ventriculoperitoneal (VP) shunt failure rate through comparing the result of standard shunt placement. All patients undergoing VP shunt from October 2007 to September 2010 were included in this retrospective study. The first group received shunt surgery using EM navigation. The second group had catheters inserted using manual method with anatomical landmark. The relationship between proximal catheter position and shunt revision rate was evaluated using postoperative computed tomography by a 3-point scale. 1) Grade I; optimal position free-floating in cerebrospinal fluid, 2) Grade II; touching choroid or ventricular wall, 3) Grade III; tip within parenchyma. A total of 72 patients were participated, 27 with EM navigated shunts and 45 with standard shunts. Grade I was found in 25 patients from group 1 and 32 patients from group 2. Only 2 patients without use of navigation belonged to grade III. Proximal obstruction took place 7% in grade I, 15% in grade II and 100% in grade III. Shunt revision occurred in 11% of group 1 and 31% of group 2. Compared in terms of proximal catheter position, there was growing trend of revision rate according to increase of grade on each group. Although infection rate was similar between both groups, the result had no statistical meaning (p=0.905, chi-square test). The use of EM navigation in routine shunt surgery can eliminate poor shunt placement resulting in a dramatic reduction in failure rates.

  10. Self-Expandable Stent Placement in Infrapopliteal Arteries After Unsuccessful Angioplasty Failure: One-Year Follow-up

    International Nuclear Information System (INIS)

    Peregrin, J. H.; Smirova, S.; Koznar, B.; Novotny, J.; Kovac, J.; Lastovickova, J.; Skibova, J.

    2008-01-01

    The purpose of this prospective study was to evaluate whether stent placement in infrapopliteal arteries is helpful in failed percutaneous transluminal angioplasty (PTA). Infrapopliteal PTA was performed in 70 arteries of 66 patients with chronic critical lower limb ischemia. The group comprised 55 males and 11 females, with an average age of 63.4 (range, 42-82) years. Diabetes mellitus was present in 92.4% of patients. Only the palpable anterior tibial and posterior tibial arteries were evaluated. Stents (Xpert stent; Abbot Vascular, Redwood City, CA, USA) were placed in 16 arteries where PTA was not successful (the failure was defined as residual stenosis >30% after PTA). In 54 arteries simple PTA was performed and was technically successful. Twenty-four nondilated arteries with no significant stenosis served as a comparison group. The 12-month patency rate was evaluated according to a combination of palpation and Doppler ultrasound. In all cases stent placement restored the flow in the artery immediately after unsuccessful PTA. Twelve-month follow-up showed a patency rate of 82% in the PTA group, 78% in the stent group, and 69% in the comparison group. We conclude that stent placement in the case of unsuccessful infrapopliteal PTA changed technical failure to success and restored flow in the dilated artery. At 12-month follow-up the patency rate of infrapopliteal arteries stented for PTA failure did not differ significantly either from nonstented arteries with an optimal PTA result or from a comparison group of nonintervened arteries.

  11. NEWTONIAN IMPERIALIST COMPETITVE APPROACH TO OPTIMIZING OBSERVATION OF MULTIPLE TARGET POINTS IN MULTISENSOR SURVEILLANCE SYSTEMS

    Directory of Open Access Journals (Sweden)

    A. Afghan-Toloee

    2013-09-01

    Full Text Available The problem of specifying the minimum number of sensors to deploy in a certain area to face multiple targets has been generally studied in the literatures. In this paper, we are arguing the multi-sensors deployment problem (MDP. The Multi-sensor placement problem can be clarified as minimizing the cost required to cover the multi target points in the area. We propose a more feasible method for the multi-sensor placement problem. Our method makes provision the high coverage of grid based placements while minimizing the cost as discovered in perimeter placement techniques. The NICA algorithm as improved ICA (Imperialist Competitive Algorithm is used to decrease the performance time to explore an enough solution compared to other meta-heuristic schemes such as GA, PSO and ICA. A three dimensional area is used for clarify the multiple target and placement points, making provision x, y, and z computations in the observation algorithm. A structure of model for the multi-sensor placement problem is proposed: The problem is constructed as an optimization problem with the objective to minimize the cost while covering all multiple target points upon a given probability of observation tolerance.

  12. Automatic entry point planning for robotic post-mortem CT-based needle placement.

    Science.gov (United States)

    Ebert, Lars C; Fürst, Martin; Ptacek, Wolfgang; Ruder, Thomas D; Gascho, Dominic; Schweitzer, Wolf; Thali, Michael J; Flach, Patricia M

    2016-09-01

    Post-mortem computed tomography guided placement of co-axial introducer needles allows for the extraction of tissue and liquid samples for histological and toxicological analyses. Automation of this process can increase the accuracy and speed of the needle placement, thereby making it more feasible for routine examinations. To speed up the planning process and increase safety, we developed an algorithm that calculates an optimal entry point and end-effector orientation for a given target point, while taking constraints such as accessibility or bone collisions into account. The algorithm identifies the best entry point for needle trajectories in three steps. First, the source CT data is prepared and bone as well as surface data are extracted and optimized. All vertices of the generated surface polygon are considered to be potential entry points. Second, all surface points are tested for validity within the defined hard constraints (reachability, bone collision as well as collision with other needles) and removed if invalid. All remaining vertices are reachable entry points and are rated with respect to needle insertion angle. Third, the vertex with the highest rating is selected as the final entry point, and the best end-effector rotation is calculated to avoid collisions with the body and already set needles. In most cases, the algorithm is sufficiently fast with approximately 5-6 s per entry point. This is the case if there is no collision between the end-effector and the body. If the end-effector has to be rotated to avoid collision, calculation times can increase up to 24 s due to the inefficient collision detection used here. In conclusion, the algorithm allows for fast and facilitated trajectory planning in forensic imaging.

  13. Computed Tomographic Analysis of Ventral Atlantoaxial Optimal Safe Implantation Corridors in 27 Dogs.

    Science.gov (United States)

    Leblond, Guillaume; Gaitero, Luis; Moens, Noel M M; Zur Linden, Alex; James, Fiona M K; Monteith, Gabrielle J; Runciman, John

    2017-11-01

    Objectives  Ventral atlantoaxial stabilization techniques are challenging surgical procedures in dogs. Available surgical guidelines are based upon subjective anatomical landmarks, and limited radiographic and computed tomographic data. The aims of this study were (1) to provide detailed anatomical descriptions of atlantoaxial optimal safe implantation corridors to generate objective recommendations for optimal implant placements and (2) to compare anatomical data obtained in non-affected Toy breed dogs, affected Toy breed dogs suffering from atlantoaxial instability and non-affected Beagle dogs. Methods  Anatomical data were collected from a prospectively recruited population of 27 dogs using a previously validated method of optimal safe implantation corridor analysis using computed tomographic images. Results  Optimal implant positions and three-dimensional numerical data were generated successfully in all cases. Anatomical landmarks could be used to generate objective definitions of optimal insertion points which were applicable across all three groups. Overall the geometrical distribution of all implant sites was similar in all three groups with a few exceptions. Clinical Significance  This study provides extensive anatomical data available to facilitate surgical planning of implant placement for atlantoaxial stabilization. Our data suggest that non-affected Toy breed dogs and non-affected Beagle dogs constitute reasonable research models to study atlantoaxial stabilization constructs. Schattauer GmbH Stuttgart.

  14. Percutaneous placement of peritoneal port-catheter in oncologic patients

    International Nuclear Information System (INIS)

    Orsi, Franco; Vigna, Paolo Della; Bonomo, Guido; Penco, Silvia; Lovati, Elena; Bellomi, Massimo

    2004-01-01

    The aim of this paper is to describe the technique of percutaneous ultrasound (US)-guided placement of a peritoneal port-catheter in an interventional radiological setting. Nineteen patients with peritoneal carcinomatosis were selected for intraperitoneal port-catheter placement in order to perform intracavitary receptor-immuno- or radio-immunotherapy with Ytrium-90. All the procedures were performed percutaneously under US and fluoro guidance; the insertion site for catheters was chosen according to abdominal conditions and US findings: all devices were implanted at the lower abdominal quadrants. All patients were followed up with CT and US according to the therapy protocol. The procedure was successfully completed in 15/19 patients, in 4 being contraindicated by peritoneal adhesions. No procedure-related complications and device occlusions during therapy were observed; one catheter displaced 7 months later the placement. In our experience, this procedure was feasible, reliable and easy to perform, allowing the correct administration of the planned intracavitary therapy. Peritoneal adhesions are the main limitation of peritoneal port placement. (orig.)

  15. Swarm intelligence algorithms for integrated optimization of piezoelectric actuator and sensor placement and feedback gains

    International Nuclear Information System (INIS)

    Dutta, Rajdeep; Ganguli, Ranjan; Mani, V

    2011-01-01

    Swarm intelligence algorithms are applied for optimal control of flexible smart structures bonded with piezoelectric actuators and sensors. The optimal locations of actuators/sensors and feedback gain are obtained by maximizing the energy dissipated by the feedback control system. We provide a mathematical proof that this system is uncontrollable if the actuators and sensors are placed at the nodal points of the mode shapes. The optimal locations of actuators/sensors and feedback gain represent a constrained non-linear optimization problem. This problem is converted to an unconstrained optimization problem by using penalty functions. Two swarm intelligence algorithms, namely, Artificial bee colony (ABC) and glowworm swarm optimization (GSO) algorithms, are considered to obtain the optimal solution. In earlier published research, a cantilever beam with one and two collocated actuator(s)/sensor(s) was considered and the numerical results were obtained by using genetic algorithm and gradient based optimization methods. We consider the same problem and present the results obtained by using the swarm intelligence algorithms ABC and GSO. An extension of this cantilever beam problem with five collocated actuators/sensors is considered and the numerical results obtained by using the ABC and GSO algorithms are presented. The effect of increasing the number of design variables (locations of actuators and sensors and gain) on the optimization process is investigated. It is shown that the ABC and GSO algorithms are robust and are good choices for the optimization of smart structures

  16. A Multi-objective PMU Placement Method Considering Observability and Measurement Redundancy using ABC Algorithm

    Directory of Open Access Journals (Sweden)

    KULANTHAISAMY, A.

    2014-05-01

    Full Text Available This paper presents a Multi- objective Optimal Placement of Phasor Measurement Units (MOPP method in large electric transmission systems. It is proposed for minimizing the number of Phasor Measurement Units (PMUs for complete system observability and maximizing the measurement redundancy of the system, simultaneously. The measurement redundancy means that number of times a bus is able to monitor more than once by PMUs set. A higher level of measurement redundancy can maximize the total system observability and it is desirable for a reliable power system state estimation. Therefore, simultaneous optimization of the two conflicting objectives are performed using a binary coded Artificial Bee Colony (ABC algorithm. The complete observability of the power system is first prepared and then, single line loss contingency condition is considered to the main model. The efficiency of the proposed method is validated on IEEE 14, 30, 57 and 118 bus test systems. The valuable approach of ABC algorithm is demonstrated in finding the optimal number of PMUs and their locations by comparing the performance with earlier works.

  17. Two mitochondrial genomes in Alcedinidae (Ceryle rudis/Halcyon pileata) and the phylogenetic placement of Coraciiformes.

    Science.gov (United States)

    Sun, Xiaomin; Zhao, Ruoping; Zhang, Ting; Gong, Jie; Jing, Meidong; Huang, Ling

    2017-10-01

    Coraciiformes comprises 209 species belonging to ten families with significant divergence on external morphologies and life styles. The phylogenetic placement of Coraciiformes was still in debate. Here, we determined the complete mitochondrial genomes (mitogenomes) of Crested Kingfisher (Ceryle rudis) and Black-capped Kingfisher (Halcyon pileata). The mitogenomes were 17,355 bp (C. rudis) and 17,612 bp (H. pileata) in length, and both of them contained 37 genes (two rRNA genes, 22 tRNA genes and 13 protein-coding genes) and one control region. The gene organizations and characters of two mitogenomes were similar with those of other mitogenomes in Coraciiformes, however the sizes and nucleotide composition of control regions in different mitogenomes were significantly different. Phylogenetic trees were constructed with both Bayesian and Maximum Likelihood methods based on mitogenome sequences from 11 families of six orders. The trees based on two different data sets supported the basal position of Psittacidae (Psittaciformes), the closest relationship between Cuculiformes (Cuculidae) and Trogoniformes (Trogonidae), and the close relationship between Coraciiformes and Piciformes. The phylogenetic placement of the clade including Cuculiformes and Trogoniformes has not been resolved in present study, which need further investigations with more molecular markers and species. The mitogenome sequences presented here provided valuable data for further taxonomic studies on Coraciiformes and other related groups.

  18. Accuracy of an infrared marker-based patient positioning system (ExacTrac®) for stereotactic body radiotherapy in localizing the planned isocenter using fiducial markers

    Science.gov (United States)

    Montes-Rodríguez, María de los Ángeles; Hernández-Bojórquez, Mariana; Martínez-Gómez, Alma Angélica; Contreras-Pérez, Agustín; Negrete-Hernández, Ingrid Mireya; Hernández-Oviedo, Jorge Omar; Mitsoura, Eleni; Santiago-Concha, Bernardino Gabriel

    2014-11-01

    Stereotactic Body Radiation Therapy (SBRT) requires a controlled immobilization and position monitoring of patient and target. The purpose of this work is to analyze the performance of the imaging system ExacTrac® (ETX) using infrared and fiducial markers. Materials and methods: In order to assure the accuracy of isocenter localization, a Quality Assurance procedure was applied using an infrared marker-based positioning system. Scans were acquired of an inhouse-agar gel and solid water phantom with infrared spheres. In the inner part of the phantom, three reference markers were delineated as reference and one pellet was place internally; which was assigned as the isocenter. The iPlan® RT Dose treatment planning system. Images were exported to the ETX console. Images were acquired with the ETX to check the correctness of the isocenter placement. Adjustments were made in 6D the reference markers were used to fuse the images. Couch shifts were registered. The procedure was repeated for verification purposes. Results: The data recorded of the verifications in translational and rotational movements showed averaged 3D spatial uncertainties of 0.31 ± 0.42 mm respectively 0.82° ± 0.46° in the phantom and the first correction of these uncertainties were of 1.51 ± 1.14 mm respectively and 1.37° ± 0.61°. Conclusions: This study shows a high accuracy and repeatability in positioning the selected isocenter. The ETX-system for verifying the treatment isocenter position has the ability to monitor the tracing position of interest, making it possible to be used for SBRT positioning within uncertainty ≤1mm.

  19. Accuracy of an infrared marker-based patient positioning system (ExacTrac®) for stereotactic body radiotherapy in localizing the planned isocenter using fiducial markers

    Energy Technology Data Exchange (ETDEWEB)

    Montes-Rodríguez, María de los Ángeles, E-mail: angy24538@yahoo.com; Mitsoura, Eleni [Medical Physics Graduate Programme, Universidad Autónoma del Estado de México, Facultad de Medicina, Paseo Tollocan esquina Jesús Carranza Colonia Moderna de la Cruz, C.P. 50180, Toluca, Estado de México (Mexico); Hernández-Bojórquez, Mariana; Martínez-Gómez, Alma Angélica; Contreras-Pérez, Agustín; Negrete-Hernández, Ingrid Mireya; Hernández-Oviedo, Jorge Omar; Santiago-Concha, Bernardino Gabriel [Centro de Cáncer ABC, The American British Cowdray Medical Center I.A.P. (CMABC), Calle Sur 136, no. 116, Colonia las Américas, C.P. 01120, México, D.F. (Mexico)

    2014-11-07

    Stereotactic Body Radiation Therapy (SBRT) requires a controlled immobilization and position monitoring of patient and target. The purpose of this work is to analyze the performance of the imaging system ExacTrac® (ETX) using infrared and fiducial markers. Materials and methods: In order to assure the accuracy of isocenter localization, a Quality Assurance procedure was applied using an infrared marker-based positioning system. Scans were acquired of an inhouse-agar gel and solid water phantom with infrared spheres. In the inner part of the phantom, three reference markers were delineated as reference and one pellet was place internally; which was assigned as the isocenter. The iPlan® RT Dose treatment planning system. Images were exported to the ETX console. Images were acquired with the ETX to check the correctness of the isocenter placement. Adjustments were made in 6D the reference markers were used to fuse the images. Couch shifts were registered. The procedure was repeated for verification purposes. Results: The data recorded of the verifications in translational and rotational movements showed averaged 3D spatial uncertainties of 0.31 ± 0.42 mm respectively 0.82° ± 0.46° in the phantom and the first correction of these uncertainties were of 1.51 ± 1.14 mm respectively and 1.37° ± 0.61°. Conclusions: This study shows a high accuracy and repeatability in positioning the selected isocenter. The ETX-system for verifying the treatment isocenter position has the ability to monitor the tracing position of interest, making it possible to be used for SBRT positioning within uncertainty ≤1mm.

  20. Learning experiences on role-emerging placements: an exploration from the students' perspective.

    Science.gov (United States)

    Dancza, Karina; Warren, Alison; Copley, Jodie; Rodger, Sylvia; Moran, Monica; McKay, Elizabeth; Taylor, Ann

    2013-12-01

    Occupational therapy educators are challenged to provide students with practical experiences which prepare them for ever changing health-care contexts on graduation. Role-emerging placements have been widely used internationally to help meet this challenge, but research into the learning experiences of students during these innovative placements is limited. This research investigated the enablers and barriers to learning from the perspectives of students on such placements from two European universities. Two separate qualitative studies tracked 10 final year students. Interviews explored their learning experiences prior to, during and after an eight- or 10-week role-emerging placement in a range of settings. Four themes emerged, which were (1) adapting to less doing, more thinking and planning; (2) understanding the complexity of collaboration and making it work; (3) emotional extremes; and (4) realising and using the occupational therapy perspective. These placements presented a 'roller coaster' of authentic learning experiences which created the opportunity for students to use occupation in practice and develop skills for collaborative working in an interprofessional environment. Whereas students viewed their role-emerging placement experiences positively, challenges included the emotional responses of students and placement pace. Findings suggest the need for supportive student placement experiences in both established and role-emerging areas to prepare students for a range of opportunities in an uncertain future. © 2013 Occupational Therapy Australia.

  1. The History of Nontraditional or Ectopic Placement of Reservoirs in Prosthetic Urology.

    Science.gov (United States)

    Perito, Paul; Wilson, Steven

    2016-04-01

    Reservoir placement during implantation of prosthetic urology devices has been problematic throughout the history of the surgical treatment of erectile dysfunction and urinary incontinence. We thought it would be interesting to review the history of reservoir placement leading up to current surgical techniques. To provide an overview of the past and present techniques for reservoir placement and discuss the evolutionary process leading to safe and effective placement of prosthetic reservoirs. We reviewed data pertaining to inflatable penile prosthesis (IPP) reservoirs and pressure-regulating balloons (PRB) in a chronological fashion, spanning 25 years. Main outcomes included a historical review of techniques for IPP reservoir and PRB placement leading to the subsequent incremental improvements in safety and efficacy when performing penile implants and artificial urinary sphincters. Prosthetic urologic reservoirs have traditionally been placed in the retropubic space. Over the years, urologists have attempted use of alternative spaces including peritoneal, epigastric, "ectopic," posterior to transversalis, and high submuscular. Current advances in prosthetic urologic reservoir placement allow safe and effective abdominal wall placement of reservoirs. These novel approaches appear to be so effective that urologists may now be able to cease using the traditional retropubic space for reservoir placement, even in the case of virgin pelves. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

  2. Using computer graphics to analyze the placement of neutral-beam injectors for the Mirror Fusion Test Facility

    International Nuclear Information System (INIS)

    Horvath, J.A.

    1977-01-01

    To optimize the neutral-beam current incident on the fusion plasma and limit the heat load on exposed surfaces of the Mirror Fusion Test Facility magnet coils, impingement of the neutral beams on the magnet structure must be minimized. Also, placement of the neutral-beam injectors must comply with specifications for neutral-current heating of the plasma and should allow maximum flexibility to accommodate alternative beam aiming patterns without significant hardware replacement or experiment down-time. Injector placements and aimings are analyzed by means of the Structural Analysis Movie Post Processor (SAMPP), a general-purpose graphics code for the display of three-dimensional finite-element models. SAMPP is used to visually assemble, disassemble, or cut away sections of the complex three-dimensional apparatus, which is represented by an assemblage of 8-node solid finite elements. The resulting picture is used to detect and quantify interactions between the structure and the neutral-particle beams

  3. AP: A Critical Examination of the Advanced Placement Program

    Science.gov (United States)

    Sadler, Philip M.; Sonnert, Gerhard; Tai, Robert; Klopfenstein, Kirstin

    2016-01-01

    The Advanced Placement (AP) program was created to enhance the experience of gifted students as they transition from high school to college. "AP: A Critical Examination of the Advanced Placement Program," edited by Philip M. Sadler, Gerhard Sonnert, Robert Tai, and Kirstin Klopfenstein (2010, Harvard Education Press), questions the…

  4. Incorrect position of Essure microinserts 3 months after successful bilateral placement.

    Science.gov (United States)

    Gerritse, Maria B E; Veersema, Sebastiaan; Timmermans, Anne; Brölmann, Hans A M

    2009-03-01

    To describe incorrect positions of Essure microinserts detected at 3 months' follow-up. Case report. Outpatient department of obstetrics and gynecology in a Dutch teaching hospital. Initial series of 100 patients who underwent hysteroscopic sterilization using Essure between December 2003 and June 2004. Hysteroscopic placement of the Essure System, follow-up at 3 months with transvaginal ultrasound (TVU), and hysterosalpingography. Bilateral placement rate, tubal obstruction, and detection of incorrect Essure microinsert localization at follow-up after apparent successful bilateral placement. Bilateral placement of Essure microinserts in one session was successful in 93 women (93%). In 90 of these women (96.8%), tubal obstruction was proven at follow-up 3 months later. Three incorrect positions of an Essure insert were seen: two expulsions and one perforation into the abdominal cavity. Incorrect position of Essure microinserts was seen only when the initial placement procedure was difficult. When a placement procedure was difficult or other suboptimal conditions are present during the procedure, we advise performing a TVU or pelvic X-ray in these women 4 weeks after the procedure or after the first vaginal bleeding, instead of waiting for follow-up after 3 months.

  5. Consumers with Major Depressive Disorder: Factors Influencing Job Placement

    Science.gov (United States)

    Hergenrather, Kenneth C.; Haase, Eileen; Zeglin, Robert J.; Rhodes, Scott D.

    2013-01-01

    The theory of planned behavior (TPB) was applied to study the factors that influence the intention of public rehabilitation placement professionals to place consumers with major depressive disorder (MDD) in jobs. A sample of 108 public rehabilitation placement professionals in the Mid-Atlantic region of the United States completed the MDD…

  6. Community placement and reintegration of service users from long ...

    African Journals Online (AJOL)

    Objective: To ascertain community placement and reintegration of service users from long-term mental health care facilities. Method: This study reviewed the progress during 2003 with the alternative placement of a selected candidate group of 27 service users in some of Lifecare's long-term mental health care facilities in ...

  7. 28 CFR 541.49 - Review of control unit placement.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Review of control unit placement. 541.49... INMATE DISCIPLINE AND SPECIAL HOUSING UNITS Control Unit Programs § 541.49 Review of control unit placement. (a) Unit staff shall evaluate informally and daily an inmate's adjustment within the control unit...

  8. Proposal for optimal placement platform of bikes using queueing networks.

    Science.gov (United States)

    Mizuno, Shinya; Iwamoto, Shogo; Seki, Mutsumi; Yamaki, Naokazu

    2016-01-01

    In recent social experiments, rental motorbikes and rental bicycles have been arranged at nodes, and environments where users can ride these bikes have been improved. When people borrow bikes, they return them to nearby nodes. Some experiments have been conducted using the models of Hamachari of Yokohama, the Niigata Rental Cycle, and Bicing. However, from these experiments, the effectiveness of distributing bikes was unclear, and many models were discontinued midway. Thus, we need to consider whether these models are effectively designed to represent the distribution system. Therefore, we construct a model to arrange the nodes for distributing bikes using a queueing network. To adopt realistic values for our model, we use the Google Maps application program interface. Thus, we can easily obtain values of distance and transit time between nodes in various places in the world. Moreover, we apply the distribution of a population to a gravity model and we compute the effective transition probability for this queueing network. If the arrangement of the nodes and number of bikes at each node is known, we can precisely design the system. We illustrate our system using convenience stores as nodes and optimize the node configuration. As a result, we can optimize simultaneously the number of nodes, node places, and number of bikes for each node, and we can construct a base for a rental cycle business to use our system.

  9. Concurrent Aeroservoelastic Design and Optimization of Wind Turbines

    DEFF Research Database (Denmark)

    Tibaldi, Carlo

    This work develops and investigates methods to integrate controllers in the wind turbine design process and to perform wind turbine optimization. These techniques can exploit the synergy between wind turbine components and generate new design solutions. Two frameworks to perform wind turbine...... optimization design are presented. These tools handle workflows to model a wind turbine and to evaluate loads and performances under specific conditions. Three approaches to evaluate loads are proposed and integrated in the optimization codes. The first method is based on time domain simulations, the second...... simulations, allows the selection of any controller parameter. The methods to evaluate loads and the pole-placement technique are then employed to carry out wind turbine optimization design from an aeroservoelastic prospective. Several analysis of the NREL 5 MW Reference Wind Turbine and the DTU 10 MW...

  10. Study on the placement of phosphorus fertilizer to improve fertilizer utilization by lowland rice

    International Nuclear Information System (INIS)

    Sisworo, W.H.; Riswantoro; Mardjo, M.

    1976-01-01

    An experiment for studying the placement of phosphorus fertilizer was carried out in the glass house by using 32 P-labelled superphosphate. The specific activity of the labelled fertilizer used was 0,25 mCi/g P 2 O 5 . Three placement methods were studied: (1) Hill placement: Fertilizer was burried at a distance of 5cm from the plants at the depth of 5 cm, (2) Surface placement: Fertilizer was spread on the surface, and (3) Soil mixed application: Fertilizer was mixed with the soil at the depth of 5 cm. Superphosphate was applied at the rates of 0, 30, 60, 90, and 120 kg P 25 /ha. Results obtained from the experiment showed that the dry matter production was significantly affected by the methods of placement of phosphorus fertilizer. Soil mixed placement gave the lowest yield of dry plant material. It differed significantly from the two other methods of placement. However, there was no significant difference between hill and surface placement. The placement of phosphorus fertilizer significantly affected the total uptake of phosphorus nutrient, uptake fertilizer phosphorus, and the percentage of fertilizer utilization. Surface placement gave the highest utilization of fertilizer when supplied at rates higher than 60 kg P 2 O 5 /ha. At low rate applications, hill placement was the best, but, at rates higher than 60 kg P 2 O 5 /ha the percentage of fertilizer utilization decreased. Soil mixed application was the least efficient fertilizer utilization. (author)

  11. Work Placements at 14-15 Years and Employability Skills

    Science.gov (United States)

    Messer, David

    2018-01-01

    Purpose: In the UK, concern frequently has been voiced that young people lack appropriate employability skills. One way to address this is to provide work based placements. In general, previous research findings have indicated that young people find such placements useful because of help with career choice and relevant skills. However, most…

  12. Community Resources and Job Placement

    Science.gov (United States)

    Preston, Jim

    1977-01-01

    In cooperation with the chamber of commerce, various businesses, associations, and other community agencies, the Sarasota schools (Florida) supplement their own job placement and follow-up efforts with community job development strategies for placing high school graduates. (JT)

  13. Using a computational model to quantify the potential impact of changing the placement of healthy beverages in stores as an intervention to "Nudge" adolescent behavior choice.

    Science.gov (United States)

    Wong, Michelle S; Nau, Claudia; Kharmats, Anna Yevgenyevna; Vedovato, Gabriela Milhassi; Cheskin, Lawrence J; Gittelsohn, Joel; Lee, Bruce Y

    2015-12-23

    Product placement influences consumer choices in retail stores. While sugar sweetened beverage (SSB) manufacturers expend considerable effort and resources to determine how product placement may increase SSB purchases, the information is proprietary and not available to the public health and research community. This study aims to quantify the effect of non-SSB product placement in corner stores on adolescent beverage purchasing behavior. Corner stores are small privately owned retail stores that are important beverage providers in low-income neighborhoods--where adolescents have higher rates of obesity. Using data from a community-based survey in Baltimore and parameters from the marketing literature, we developed a decision-analytic model to simulate and quantify how placement of healthy beverage (placement in beverage cooler closest to entrance, distance from back of the store, and vertical placement within each cooler) affects the probability of adolescents purchasing non-SSBs. In our simulation, non-SSB purchases were 2.8 times higher when placed in the "optimal location"--on the second or third shelves of the front cooler--compared to the worst location on the bottom shelf of the cooler farthest from the entrance. Based on our model results and survey data, we project that moving non-SSBs from the worst to the optional location would result in approximately 5.2 million more non-SSBs purchased by Baltimore adolescents annually. Our study is the first to quantify the potential impact of changing placement of beverages in corner stores. Our findings suggest that this could be a low-cost, yet impactful strategy to nudge this population--highly susceptible to obesity--towards healthier beverage decisions.

  14. Clinical predictors of port infections within the first 30 days of placement.

    Science.gov (United States)

    Bamba, Ravinder; Lorenz, Jonathan M; Lale, Allison J; Funaki, Brian S; Zangan, Steven M

    2014-03-01

    To identify risk factors for port infections within 30 days of placement. A retrospective chart review of port placements from 2002-2009 was conducted. Patients who had port removals secondary to infection within the first 30 days of placement were included. This group of patients was compared with a control group of patients with ports with no evidence of infection. For every one patient with a port infection, two control subjects were chosen of the same gender and new port placement during the same month as the corresponding patient with an infected port. From 2002-2009, 4,404 ports were placed. Of the 4,404 patients, 33 (0.7%) were found to have a port infection within 30 days of placement. Compared with the control group, the early infection group had a higher prevalence of leukopenia (21.2% vs 6.1%, P = .039) and thrombocytopenia (33% vs 12%, P = .0158). There was also a higher prevalence of an inpatient hospital stay during port placement and high international normalized ratio in the early infection group. Low preoperative white blood cell and platelet counts were risk factors for early infection. Abnormal coagulation profiles and inpatient access of ports after placement could be additional risk factors. Copyright © 2014 SIR. Published by Elsevier Inc. All rights reserved.

  15. Characteristics of People Providing Family Placements to Adult Persons with Intellectual Disabilities

    Science.gov (United States)

    McConkey, Roy; McConaghie, Jayne; Roberts, Paul; King, Diana

    2005-01-01

    The success of family placement schemes depends largely on the recruitment of suitable people who are willing to offer placements in their own home yet little research has been undertaken of their characteristics and the reasons for their involvement. Thirty providers of family based placements to adult persons with intellectual disabilities were…

  16. A Case for Faculty Involvement in EAP Placement Testing

    Science.gov (United States)

    James, Cindy; Templeman, Elizabeth

    2009-01-01

    The EAP placement procedure at Thompson Rivers University (TRU) involves multiple measures to assess the language skills of incoming students, some of which are facilitated and all of which are assessed by ESL faculty. In order to determine the effectiveness of this comprehensive EAP placement process and the effect of the faculty factor, a…

  17. Effect of posterior crown margin placement on gingival health.

    Science.gov (United States)

    Reitemeier, Bernd; Hänsel, Kristina; Walter, Michael H; Kastner, Christian; Toutenburg, Helge

    2002-02-01

    The clinical impact of posterior crown margin placement on gingival health has not been thoroughly quantified. This study evaluated the effect of posterior crown margin placement with multivariate analysis. Ten general dentists reviewed 240 patients with 480 metal-ceramic crowns in a prospective clinical trial. The alloy was randomly selected from 2 high gold, 1 low gold, and 1 palladium alloy. Variables were the alloy used, oral hygiene index score before treatment, location of crown margins at baseline, and plaque index and sulcus bleeding index scores recorded for restored and control teeth after 1 year. The effect of crown margin placement on sulcular bleeding and plaque accumulation was analyzed with regression models (Prisk of bleeding at intrasulcular posterior crown margins was approximately twice that at supragingival margins. Poor oral hygiene before treatment and plaque also were associated with sulcular bleeding. Facial sites exhibited a lower probability of sulcular bleeding than lingual surfaces. Type of alloy did not influence sulcular bleeding. In this study, placement of crown margins was one of several parameters that affected gingival health.

  18. Confirmation of gastric tube bedside placement with the sky blue method.

    Science.gov (United States)

    Imamura, Takashi; Maeda, Hajime; Kinoshita, Hidetoshi; Shibukawa, Yasuko; Suda, Kiyomi; Fukuda, Yutaka; Goto, Aya; Nagasawa, Katsutoshi

    2014-02-01

    The purpose was to review our experiences and determine if applying the sky blue method is reliable in confirming gastric tube (GT) placement in neonates. The study population consisted of 44 infants (55 placements) who were admitted to the Takeda General Hospital between April 2012 and March 2013 and who required GT exchange. The sky blue method using indigo carmine (IC) was indicated for planned tube exchange only. Diluted IC was injected into the gastric space via the old GT just before the tube exchange. The tube was exchanged using a standard method. Then, we checked whether the diluted IC could be collected through the new GT or not. The reasons for GT placement were a gestational age of sky blue method was considered successful in 52 placements (94.4%), with the remaining 3 placements (5.6%) considered to be failures due to the inability to obtain IC from the gastric space. No adverse events were observed during the tube exchange period. Based on the results, the sky blue method can be considered to be reliable method for the confirmation of GT placement. These results also suggest that the number of radiologic evaluations performed to confirm correct replacement of the GT in infants can be reduced in the future.

  19. Isotropic Optical Mouse Placement for Mobile Robot Velocity Estimation

    Directory of Open Access Journals (Sweden)

    Sungbok Kim

    2014-06-01

    Full Text Available This paper presents the isotropic placement of multiple optical mice for the velocity estimation of a mobile robot. It is assumed that there can be positional restriction on the installation of optical mice at the bottom of a mobile robot. First, the velocity kinematics of a mobile robot with an array of optical mice is obtained and the resulting Jacobian matrix is analysed symbolically. Second, the isotropic, anisotropic and singular optical mouse placements are identified, along with the corresponding characteristic lengths. Third, the least squares mobile robot velocity estimation from the noisy optical mouse velocity measurements is discussed. Finally, simulation results for several different placements of three optical mice are given.

  20. A hybrid of ant colony optimization and artificial bee colony algorithm for probabilistic optimal placement and sizing of distributed energy resources

    International Nuclear Information System (INIS)

    Kefayat, M.; Lashkar Ara, A.; Nabavi Niaki, S.A.

    2015-01-01

    Highlights: • A probabilistic optimization framework incorporated with uncertainty is proposed. • A hybrid optimization approach combining ACO and ABC algorithms is proposed. • The problem is to deal with technical, environmental and economical aspects. • A fuzzy interactive approach is incorporated to solve the multi-objective problem. • Several strategies are implemented to compare with literature methods. - Abstract: In this paper, a hybrid configuration of ant colony optimization (ACO) with artificial bee colony (ABC) algorithm called hybrid ACO–ABC algorithm is presented for optimal location and sizing of distributed energy resources (DERs) (i.e., gas turbine, fuel cell, and wind energy) on distribution systems. The proposed algorithm is a combined strategy based on the discrete (location optimization) and continuous (size optimization) structures to achieve advantages of the global and local search ability of ABC and ACO algorithms, respectively. Also, in the proposed algorithm, a multi-objective ABC is used to produce a set of non-dominated solutions which store in the external archive. The objectives consist of minimizing power losses, total emissions produced by substation and resources, total electrical energy cost, and improving the voltage stability. In order to investigate the impact of the uncertainty in the output of the wind energy and load demands, a probabilistic load flow is necessary. In this study, an efficient point estimate method (PEM) is employed to solve the optimization problem in a stochastic environment. The proposed algorithm is tested on the IEEE 33- and 69-bus distribution systems. The results demonstrate the potential and effectiveness of the proposed algorithm in comparison with those of other evolutionary optimization methods

  1. An Improvement in Thermal Modelling of Automated Tape Placement Process

    International Nuclear Information System (INIS)

    Barasinski, Anaies; Leygue, Adrien; Poitou, Arnaud; Soccard, Eric

    2011-01-01

    The thermoplastic tape placement process offers the possibility of manufacturing large laminated composite parts with all kinds of geometries (double curved i.e.). This process is based on the fusion bonding of a thermoplastic tape on a substrate. It has received a growing interest during last years because of its non autoclave abilities.In order to control and optimize the quality of the manufactured part, we need to predict the temperature field throughout the processing of the laminate. In this work, we focus on a thermal modeling of this process which takes in account the imperfect bonding existing between the different layers of the substrate by introducing thermal contact resistance in the model. This study is leaning on experimental results which inform us that the value of the thermal resistance evolves with temperature and pressure applied on the material.

  2. PRODUCT PLACEMENT IN BRAND PROMOTION

    Directory of Open Access Journals (Sweden)

    Alicja Mikołajczyk

    2015-06-01

    Full Text Available Product placement can have a significant impact on brand awareness and customer purchasing decisions. The article discusses techniques applied in the mass media against the EU legal background and the opportunities it offers in reaching the target audience.

  3. Post-placement temperature reduction techniques

    DEFF Research Database (Denmark)

    Liu, Wei; Nannarelli, Alberto

    2010-01-01

    With technology scaled to deep submicron era, temperature and temperature gradient have emerged as important design criteria. We propose two post-placement techniques to reduce peak temperature by intelligently allocating whitespace in the hotspots. Both methods are fully compliant with commercial...

  4. Hepatocellular Carcinoma Complicated by Gastroduodenal Obstruction: Palliative Treatment with Metallic Stent Placement

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ye Jin; Kim, Jin Hyoung, E-mail: m1fenew@daum.net; Song, Ho-Young; Park, Jung-Hoon; Na, Han Kyu; Kim, Pyeong Hwa; Fan, Yong [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center (Korea, Republic of)

    2012-10-15

    Purpose: To evaluate the clinical effectiveness of self-expandable metallic stents in seven patients with malignant gastroduodenal obstruction caused by inoperable hepatocellular carcinoma (HCC). Methods: Seven patients with gastroduodenal obstruction caused by advanced HCC underwent metallic stent placement from 2003 to 2010. These patients had total dysphagia (n = 5) or were able to eat only liquids (n = 2) before stent placement. Patients had Eastern Cooperative Oncology Group performance scores of 2 or 3, and Child-Pugh classification B or C. Results: Stent placement was technically successful in all seven patients (100%) and clinically successful in six (86%). Five patients could eat a soft diet, and one patient tolerated regular diet after stent placement. Stent-related obstructive jaundice occurred in one patient. One patient had hematemesis 11 days after stent placement. Overall mean survival was 51 days (range, 10-119 days). Stent patency was preserved in six patients with clinical success until death. Conclusion: Placement of a covered self-expandable metallic stent may offer good palliation in patients with gastroduodenal obstruction due to advanced HCC.

  5. Hepatocellular Carcinoma Complicated by Gastroduodenal Obstruction: Palliative Treatment with Metallic Stent Placement

    International Nuclear Information System (INIS)

    Lee, Ye Jin; Kim, Jin Hyoung; Song, Ho-Young; Park, Jung-Hoon; Na, Han Kyu; Kim, Pyeong Hwa; Fan, Yong

    2012-01-01

    Purpose: To evaluate the clinical effectiveness of self-expandable metallic stents in seven patients with malignant gastroduodenal obstruction caused by inoperable hepatocellular carcinoma (HCC). Methods: Seven patients with gastroduodenal obstruction caused by advanced HCC underwent metallic stent placement from 2003 to 2010. These patients had total dysphagia (n = 5) or were able to eat only liquids (n = 2) before stent placement. Patients had Eastern Cooperative Oncology Group performance scores of 2 or 3, and Child-Pugh classification B or C. Results: Stent placement was technically successful in all seven patients (100%) and clinically successful in six (86%). Five patients could eat a soft diet, and one patient tolerated regular diet after stent placement. Stent-related obstructive jaundice occurred in one patient. One patient had hematemesis 11 days after stent placement. Overall mean survival was 51 days (range, 10–119 days). Stent patency was preserved in six patients with clinical success until death. Conclusion: Placement of a covered self-expandable metallic stent may offer good palliation in patients with gastroduodenal obstruction due to advanced HCC.

  6. Wireless sensor placement for structural monitoring using information-fusing firefly algorithm

    Science.gov (United States)

    Zhou, Guang-Dong; Yi, Ting-Hua; Xie, Mei-Xi; Li, Hong-Nan

    2017-10-01

    Wireless sensor networks (WSNs) are promising technology in structural health monitoring (SHM) applications for their low cost and high efficiency. The limited wireless sensors and restricted power resources in WSNs highlight the significance of optimal wireless sensor placement (OWSP) during designing SHM systems to enable the most useful information to be captured and to achieve the longest network lifetime. This paper presents a holistic approach, including an optimization criterion and a solution algorithm, for optimally deploying self-organizing multi-hop WSNs on large-scale structures. The combination of information effectiveness represented by the modal independence and the network performance specified by the network connectivity and network lifetime is first formulated to evaluate the performance of wireless sensor configurations. Then, an information-fusing firefly algorithm (IFFA) is developed to solve the OWSP problem. The step sizes drawn from a Lévy distribution are adopted to drive fireflies toward brighter individuals. Following the movement with Lévy flights, information about the contributions of wireless sensors to the objective function as carried by the fireflies is fused and applied to move inferior wireless sensors to better locations. The reliability of the proposed approach is verified via a numerical example on a long-span suspension bridge. The results demonstrate that the evaluation criterion provides a good performance metric of wireless sensor configurations, and the IFFA outperforms the simple discrete firefly algorithm.

  7. Development of an MRI/x-ray/ultrasound compatible marker for pre-operative breast tumour localization

    International Nuclear Information System (INIS)

    Li Yangmei; Wang, Jianxiong; Holloway, Claire; Plewes, Donald B

    2005-01-01

    This paper describes an in vitro investigation into the composition, structure and development of an magnetic resonance imaging (MRI), ultrasound (US) and x-ray imaging compatible marker for breast tumour localization. The marker is composed of 0.4-0.6 mm glass and iron-containing aluminium microspheres suspended in a gelatin matrix. The final form of the marker is a cylindrical shape 7 mm long with 2.05 mm diameter to facilitate delivery through a 12 gauge biopsy needle. To get optimal reflectivity for the US contrast, the glass microsphere concentration was found to be 40% by weight. US contrast is independent of marker orientation and the cylindrical shape made its US signal appearance distinctive thus ensuring confident identification. To control the MRI contrast, iron content was varied to generate a clear and local susceptibility signal void to reflect the marker position. Optimal iron content was found to be 52 μg iron which produced a clear signal void in spoiled gradient recalled MR images. The appearance of the susceptibility artefact is determined by the marker's shape, orientation and echo time. The final marker produces a dark artefact in MRI while appears as a clear hyperintense structure with acoustic shadowing in US images. The x-ray image showed the marker as a radio-opaque structure. This in vitro study demonstrates that the marker forms an alternative to traditional wire localization currently used for breast surgical procedures and creates new opportunities for US guided surgical procedures

  8. A new branch of advertising: reviewing factors that influence reactions to product placement

    NARCIS (Netherlands)

    van Reijmersdal, E.; Neijens, P.; Smit, E.G.

    2009-01-01

    This iiterature review presents a quantitative synthesis of 57 studies on product placement and shows which factors are most effective, it shows that placement characteristics, such as placement commerciality, modality, and prominence, have a strong impact on audience reactions. Audience

  9. Is the Routine Check Nephrostogram Following Percutaneous Antegrade Ureteric Stent Placement Necessary?

    International Nuclear Information System (INIS)

    Soh, Keng Chuan; Tay, Kiang Hiong; Tan, Bien Soo; MM Htoo, Austin; HG Lo, Richard; Lin, Shueh En

    2008-01-01

    Our aim was to review our experience with percutaneous antegrade ureteric stent (PAUS) placement and to determine if the routinely conducted check nephrostogram on the day following ureteric stent placement was necessary. Retrospective review of patients who had undergone PAUS placement between January 2004 and December 2005 was performed. There were 83 subjects (36 males, 47 females), with a mean age of 59.9 years (range, 22-94 years). Average follow-up duration was 7.1 months (range, 1-24 months). The most common indications for PAUS placement were ureteric obstruction due to metastatic disease (n = 56) and urinary calculi (n = 34). Technical success was 93.2% (96/103 attempts), with no major immediate procedure-related complications or mortalities. The Bard 7Fr Urosoft DJ Stent was used in more than 95% of the cases. Eighty-one of 89 (91.0%) check nephrostograms demonstrated a patent ureteric stent with resultant safety catheter removal. Three check nephrostograms revealed distal stent migration requiring repositioning by a goose-snare, while five others showed stent occlusion necessitating permanent external drainage by nephrostomy drainage catheter reinsertion. Following PAUS placement, the serum creatinine level improved or stabilized in 82% of patients. The serum creatinine outcome difference between the groups with benign and malignant indications for PAUS placement was not statistically significant (p = 0.145) but resolution of hydronephrosis was significantly better (p = 0.008) in patients with benign indications. Percutaneous antegrade ureteric stent placement is a safe and effective means of relief for ureteric obstruction. The check nephrostogram following ureteric stent placement was unnecessary in the majority of patients

  10. [Family caregivers' adjustment to nursing home placement of older relatives].

    Science.gov (United States)

    Wang, Szu-Yao; Davies, Elizabeth

    2007-06-01

    The literature on the impact of nursing home placement of older parents on family caregivers is still incomplete. Family caregivers experience stress, shock, anxiety, fear, resistance, and guilt in the process of decision making. The literature has demonstrated that family caregivers continue to experience stress and problems after placing older relatives into a long term care facility. Cultural values impact on people's attitudes, values and expectations. Culture will therefore affect the care-giving experience. Relatively little information is available from Asian and multicultural societies. Identifying family caregiver experiences after nursing home placement can alert professionals to the need for family guidance prior to nursing home placement and assist in early identification of potential problems. This article reviews the literature and discusses the impact on family caregivers of making a decision for nursing home placement and dealing with the stress and challenges that persist after nursing home admission.

  11. Clinical placements and nursing students' career planning: a qualitative exploration.

    Science.gov (United States)

    McKenna, Lisa; McCall, Louise; Wray, Natalie

    2010-04-01

    Many nursing students enter undergraduate programmes with preconceived ideas about their future nursing careers, and intend to practice in particular areas such as midwifery or paediatrics. Through clinical placements, students are exposed to different clinical areas and professional socialization is facilitated. However, little is known about the influence of clinical placements on students' career intentions. This paper reports nursing findings drawn from a large qualitative study conducted in Victoria, Australia that sought to explore the influence of health professional students' clinical placements on their future career intentions. Participants were invited to be involved in either face-to-face or focus group interviews depending upon their own preference. Thematic data analysis revealed three main themes: 're-affirming career choice', 'working in a particular area' and 'work location'. Findings from the study add to our understanding of factors influencing nursing students' planning for their future careers including the impact of clinical placements.

  12. First magnetic resonance imaging-guided aortic stenting and cava filter placement using a polyetheretherketone-based magnetic resonance imaging-compatible guidewire in swine: proof of concept.

    Science.gov (United States)

    Kos, Sebastian; Huegli, Rolf; Hofmann, Eugen; Quick, Harald H; Kuehl, Hilmar; Aker, Stephanie; Kaiser, Gernot M; Borm, Paul J A; Jacob, Augustinus L; Bilecen, Deniz

    2009-05-01

    The purpose of this study was to demonstrate feasibility of percutaneous transluminal aortic stenting and cava filter placement under magnetic resonance imaging (MRI) guidance exclusively using a polyetheretherketone (PEEK)-based MRI-compatible guidewire. Percutaneous transluminal aortic stenting and cava filter placement were performed in 3 domestic swine. Procedures were performed under MRI-guidance in an open-bore 1.5-T scanner. The applied 0.035-inch guidewire has a PEEK core reinforced by fibres, floppy tip, hydrophilic coating, and paramagnetic markings for passive visualization. Through an 11F sheath, the guidewire was advanced into the abdominal (swine 1) or thoracic aorta (swine 2), and the stents were deployed. The guidewire was advanced into the inferior vena cava (swine 3), and the cava filter was deployed. Postmortem autopsy was performed. Procedural success, guidewire visibility, pushability, and stent support were qualitatively assessed by consensus. Procedure times were documented. Guidewire guidance into the abdominal and thoracic aortas and the inferior vena cava was successful. Stent deployments were successful in the abdominal (swine 1) and thoracic (swine 2) segments of the descending aorta. Cava filter positioning and deployment was successful. Autopsy documented good stent and filter positioning. Guidewire visibility through applied markers was rated acceptable for aortic stenting and good for venous filter placement. Steerability, pushability, and device support were good. The PEEK-based guidewire allows either percutaneous MRI-guided aortic stenting in the thoracic and abdominal segments of the descending aorta and filter placement in the inferior vena cava with acceptable to good device visibility and offers good steerability, pushability, and device support.

  13. First Magnetic Resonance Imaging-Guided Aortic Stenting and Cava Filter Placement Using a Polyetheretherketone-Based Magnetic Resonance Imaging-Compatible Guidewire in Swine: Proof of Concept

    International Nuclear Information System (INIS)

    Kos, Sebastian; Huegli, Rolf; Hofmann, Eugen; Quick, Harald H.; Kuehl, Hilmar; Aker, Stephanie; Kaiser, Gernot M.; Borm, Paul J. A.; Jacob, Augustinus L.; Bilecen, Deniz

    2009-01-01

    The purpose of this study was to demonstrate feasibility of percutaneous transluminal aortic stenting and cava filter placement under magnetic resonance imaging (MRI) guidance exclusively using a polyetheretherketone (PEEK)-based MRI-compatible guidewire. Percutaneous transluminal aortic stenting and cava filter placement were performed in 3 domestic swine. Procedures were performed under MRI-guidance in an open-bore 1.5-T scanner. The applied 0.035-inch guidewire has a PEEK core reinforced by fibres, floppy tip, hydrophilic coating, and paramagnetic markings for passive visualization. Through an 11F sheath, the guidewire was advanced into the abdominal (swine 1) or thoracic aorta (swine 2), and the stents were deployed. The guidewire was advanced into the inferior vena cava (swine 3), and the cava filter was deployed. Postmortem autopsy was performed. Procedural success, guidewire visibility, pushability, and stent support were qualitatively assessed by consensus. Procedure times were documented. Guidewire guidance into the abdominal and thoracic aortas and the inferior vena cava was successful. Stent deployments were successful in the abdominal (swine 1) and thoracic (swine 2) segments of the descending aorta. Cava filter positioning and deployment was successful. Autopsy documented good stent and filter positioning. Guidewire visibility through applied markers was rated acceptable for aortic stenting and good for venous filter placement. Steerability, pushability, and device support were good. The PEEK-based guidewire allows either percutaneous MRI-guided aortic stenting in the thoracic and abdominal segments of the descending aorta and filter placement in the inferior vena cava with acceptable to good device visibility and offers good steerability, pushability, and device support.

  14. Product Category Layout and Organization: Retail Placement of Food Products

    NARCIS (Netherlands)

    Herpen, van E.

    2016-01-01

    This article discusses the placement of food products in retail stores, in particular how the placement of food products can influence how consumers perceive the store in general and these products in particular. It reviews the overall layout of the store, assortment organization, and shelf

  15. [The implementation of Individual Placement and Support in the Netherlands].

    Science.gov (United States)

    Giesen, F; van Erp, N; van Weeghel, J; Michon, H; Kroon, H

    2007-01-01

    Individual Placement and Support is a vocational rehabilitation programme for people with severe mental illness, which was implemented during the period 2003-2005 at four locations in the Netherlands. To investigate the degree of compliance with the Individual Placement and Support programme, the factors that hindered or facilitated its implementation, and the results. The degree of compliance was assessed using the Individual Placement and Support fidelity scale. Data regarding the factors that hindered or facilitated the implementation were collected via interviews and monitoring. In addition, data were collected on patient characteristics, the support provided and the jobs found. None of the locations achieved the highest level of compliance, although two locations came close. Eighteen per cent of the 316 patients were helped to find a regular job. The most important obstacles to implementation were loss of vocational team members, project leaders' lack of time, lack of finance, and insufficient cooperation between the organisations involved. The most important facilitating factors were the skills and commitment of the vocational team member(s) and the integration of the vocational teammember(s) and the mental health team. It is not easy to implement Individual Placement and Support. However, if more attention is given to good project management, Individual Placement and Support can succeed in the Netherlands.

  16. The optimal location of piezoelectric actuators and sensors for vibration control of plates

    Science.gov (United States)

    Kumar, K. Ramesh; Narayanan, S.

    2007-12-01

    This paper considers the optimal placement of collocated piezoelectric actuator-sensor pairs on a thin plate using a model-based linear quadratic regulator (LQR) controller. LQR performance is taken as objective for finding the optimal location of sensor-actuator pairs. The problem is formulated using the finite element method (FEM) as multi-input-multi-output (MIMO) model control. The discrete optimal sensor and actuator location problem is formulated in the framework of a zero-one optimization problem. A genetic algorithm (GA) is used to solve the zero-one optimization problem. Different classical control strategies like direct proportional feedback, constant-gain negative velocity feedback and the LQR optimal control scheme are applied to study the control effectiveness.

  17. Retrievable Airway Stent Placement for Stoma Stricture after Anterior Mediastinal Tracheostomy: Case Report

    International Nuclear Information System (INIS)

    Hwang, Jae Yeon; Shin, Ji Hoon; Kim, Yong Hee; Song, Ho Young; Kim, Jin Hyoung; Lee, Yeoun Joo

    2013-01-01

    Anterior mediastinal tracheostomy (AMT) is performed to establish an airway after resection of advanced tumors in the cervicothoracic region. We report a case of successful placement of a covered retrievable self-expandable nitinol stent for a stoma stricture that developed after AMT in a patient with adenoid cystic carcinoma of the trachea. Two stent placements and removals, at two and three months after their initial placement, were performed due to loosening of the stents. Although we did not achieve long-term results as the patient died of massive hemorrhage, the stent placement was both feasible and safe, thus suggesting that temporary stent placement may be a valuable option for treating stoma stricture occurring after AMT.

  18. Retrievable Airway Stent Placement for Stoma Stricture after Anterior Mediastinal Tracheostomy: Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Jae Yeon; Shin, Ji Hoon; Kim, Yong Hee; Song, Ho Young; Kim, Jin Hyoung [Dept. of University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Lee, Yeoun Joo [Dept. of Pediatrics, Pusan National University Children' s Hospital, Yangsan (Korea, Republic of)

    2013-06-15

    Anterior mediastinal tracheostomy (AMT) is performed to establish an airway after resection of advanced tumors in the cervicothoracic region. We report a case of successful placement of a covered retrievable self-expandable nitinol stent for a stoma stricture that developed after AMT in a patient with adenoid cystic carcinoma of the trachea. Two stent placements and removals, at two and three months after their initial placement, were performed due to loosening of the stents. Although we did not achieve long-term results as the patient died of massive hemorrhage, the stent placement was both feasible and safe, thus suggesting that temporary stent placement may be a valuable option for treating stoma stricture occurring after AMT.

  19. Outcomes of Temporary Partially Covered Stent Placement for Benign Tracheobronchial Stenosis

    International Nuclear Information System (INIS)

    Ma, Ji; Han, Xinwei; Wu, Gang; Jiao, Dechao; Ren, Kewei; Bi, Yonghua

    2016-01-01

    PurposeTo evaluate the intermediate outcomes of temporary partially covered tracheobronchial stenting in patients with benign tracheobronchial stenosis.Materials and MethodsWe conducted a retrospective study of patients with benign tracheobronchial stenosis who underwent stent placement. All stents were removed approximately 3 months after placement. Respiratory function was assessed using the visual analogue scale (VAS) and Karnofsky performance status scale (KPS) before and after stent placement. The lumen diameters of the stenotic lesions were measured using chest computed tomography (CT) and compared between before stent placement and after stent removal.ResultsA total of 51 stents were successfully placed in consecutive 51 patients with benign tracheobronchial stenosis. No serious complications occurred. The mean VAS and KPS scores significantly improved after stent removal (6.291 ± 0.495 and 25.352 ± 10.533, respectively) compared with those before stent placement (1.493 ± 0.504 and 60.140 ± 16.344, respectively; P   0.05).ConclusionTemporary partially covered stenting may be a safe and effective treatment for benign tracheobronchial stenosis.

  20. Outcomes of Temporary Partially Covered Stent Placement for Benign Tracheobronchial Stenosis.

    Science.gov (United States)

    Ma, Ji; Han, Xinwei; Wu, Gang; Jiao, Dechao; Ren, Kewei; Bi, Yonghua

    2016-08-01

    To evaluate the intermediate outcomes of temporary partially covered tracheobronchial stenting in patients with benign tracheobronchial stenosis. We conducted a retrospective study of patients with benign tracheobronchial stenosis who underwent stent placement. All stents were removed approximately 3 months after placement. Respiratory function was assessed using the visual analogue scale (VAS) and Karnofsky performance status scale (KPS) before and after stent placement. The lumen diameters of the stenotic lesions were measured using chest computed tomography (CT) and compared between before stent placement and after stent removal. A total of 51 stents were successfully placed in consecutive 51 patients with benign tracheobronchial stenosis. No serious complications occurred. The mean VAS and KPS scores significantly improved after stent removal (6.291 ± 0.495 and 25.352 ± 10.533, respectively) compared with those before stent placement (1.493 ± 0.504 and 60.140 ± 16.344, respectively; P  0.05). Temporary partially covered stenting may be a safe and effective treatment for benign tracheobronchial stenosis.

  1. DIM and diagnostic placement for NIF experiments

    International Nuclear Information System (INIS)

    Kalantar, D.

    1999-01-01

    The input that has been provided on the NIF experiment setup sheets has allowed us to review the diagnostic and DIM placement as well as the baseline unconverted light management plan. We have done an iteration to identify common diagnostic lines of sight, and with additional requirements defined by specific experiments, we propose (1) a baseline plan for DIM placement requiring only five DIMs that may be moved between up to seven DIM ports, and (2) a modified baseline unconverted light management plan. We request additional input to identify primary vs. secondary diagnostics for each experiment definition

  2. Molecular markers to assess genetic diversity and mutant identifications in Jatropha curcas

    International Nuclear Information System (INIS)

    Azhar Mohamad; Yie Min Kwan; Fatin Mastura Derani; Abdul Rahim Harun

    2010-01-01

    Jatropha curcas (Linnaeus) belongs to the Euphorbiaceae family, is a multipurpose use, drought resistant and perennial plant. It is an economic important crop, which generates wide interest in understanding the genetic diversity of the species towards selection and breeding of superior genotypes. Jatropha accessions are closely related family species. Thus, better understanding of the effectiveness of the different DNA-based markers is an important step towards plant germplasm characterization and evaluation. It is becoming a prerequisite for more effective application of marker techniques in breeding programs. Inter-simple sequence repeats (ISSRs) has shown rapid, simple, reproducible and inexpensive means in molecular taxonomy, conservation breeding and genetic diversity analysis. These markers were used to understand diversity and differentiate amongst accessions of Jatropha population and mutant lines generated by acute gamma radiation. The ISSR for marker applications are essential to facilitate management, conservation and genetic improvement programs towards improvement of bio-diesel production and medication substances. A total of 62 ISSR primers were optimized for polymorphism evaluations on five foreign accessions (Africa, India, Myanmar, Indonesia, Thailand), nine local accessions and two mutants of Jatropha. Optimization was resulted 54 ISSR primers affirmative for the polymorphism evaluation study, which encountered 12 ISSR primers, showed significance polymorphism amongst the accessions and mutants. Marker derived from ISSR profiling is a powerful method for identification and molecular classification of Jatropha from accession to generated mutant varieties. (author)

  3. A conformal mapping based fractional order approach for sub-optimal tuning of PID controllers with guaranteed dominant pole placement

    Science.gov (United States)

    Saha, Suman; Das, Saptarshi; Das, Shantanu; Gupta, Amitava

    2012-09-01

    A novel conformal mapping based fractional order (FO) methodology is developed in this paper for tuning existing classical (Integer Order) Proportional Integral Derivative (PID) controllers especially for sluggish and oscillatory second order systems. The conventional pole placement tuning via Linear Quadratic Regulator (LQR) method is extended for open loop oscillatory systems as well. The locations of the open loop zeros of a fractional order PID (FOPID or PIλDμ) controller have been approximated in this paper vis-à-vis a LQR tuned conventional integer order PID controller, to achieve equivalent integer order PID control system. This approach eases the implementation of analog/digital realization of a FOPID controller with its integer order counterpart along with the advantages of fractional order controller preserved. It is shown here in the paper that decrease in the integro-differential operators of the FOPID/PIλDμ controller pushes the open loop zeros of the equivalent PID controller towards greater damping regions which gives a trajectory of the controller zeros and dominant closed loop poles. This trajectory is termed as "M-curve". This phenomena is used to design a two-stage tuning algorithm which reduces the existing PID controller's effort in a significant manner compared to that with a single stage LQR based pole placement method at a desired closed loop damping and frequency.

  4. Health professional students' rural placement satisfaction and rural practice intentions: A national cross-sectional survey.

    Science.gov (United States)

    Smith, Tony; Sutton, Keith; Pit, Sabrina; Muyambi, Kuda; Terry, Daniel; Farthing, Annie; Courtney, Claire; Cross, Merylin

    2018-02-01

    The aim of this study was to profile students undertaking placements at University Departments of Rural Health (UDRHs) and investigate factors affecting students' satisfaction and intention to enter rural practice. Cross-sectional survey comprising 21 core questions used by all UDRHs. Eleven UDRHs across Australia that support students' placements in regional, rural and remote locations. Medical, nursing and allied health students who participated in UDRH placements between July 2014 and November 2015 and completed the questionnaire. Key dependent variables were placement satisfaction and rural practice intention. Descriptive variables were age, gender, Aboriginal or Torres Strait Islander (ATSI) background, location of placement, healthcare discipline, year of study and type and length of placement. A total of 3328 students responded. The sample was predominantly female (79%), the mean age was 26.0 years and 1.8% identified as ATSI. Most placements (69%) were >2 but ≤12 weeks, 80% were in Modified Monash 3, 4 or 5 geographical locations. Public hospitals and community health made up 63% of placements. Students satisfied with their placement had 2.33 higher odds of rural practice intention. Those satisfied with Indigenous cultural training, workplace supervision, access to education resources and accommodation had higher odds of overall satisfaction and post-placement rural practice intention. The majority of students were highly satisfied with their placement and the support provided by rural clinicians and the UDRHs. UDRHs are well placed to provide health professional students with highly satisfactory placements that foster rural practice intention. © 2017 National Rural Health Alliance Inc.

  5. Distinguishing implicit from explicit brand attitudes in brand placement research

    NARCIS (Netherlands)

    Wennekers, A.M.; Vandeberg, L.; Zoon, K.; van Reijmersdal, E.A.; Verlegh, P.; Voorveld, H.; Eisend, M.

    2016-01-01

    Brand placement is a popular topic, both in business and academia. Brands are placed in a wide-ranging array of media, including television programs, movies, radio shows, magazines, games, music videos, and websites. Expenditures on brand placement are still growing (PQ Media, 2013), as well as the

  6. Retrograde or antegrade double-pigtail stent placement for malignant ureteric obstruction?

    International Nuclear Information System (INIS)

    Uthappa, M.C.; Cowan, N.C.

    2005-01-01

    AIM: To determine the optimum approach for double-pigtail stent placement in malignant ureteric obstruction. PATIENTS AND METHODS: Retrograde stent placement was attempted in a consecutive series of patients presenting with malignant ureteric obstruction. If retrograde stent placement was unsuccessful, percutaneous nephrostomy was performed immediately followed by elective antegrade stent placement. Identical digital C-arm fluoroscopy for image-guidance and conditions for anaesthesia and analgesia were employed for both retrograde and antegrade procedures. Identical 8 Fr (20-26 cm) double-pigtail hydrophilic coated stents were used for each approach. RESULTS: Retrograde placement was attempted in 50 ureters in 30 patients {19 male, 11 female, average age 61.4 yr (range 29-90 yr)} over a 24-month period. The success rate for retrograde ureteric stent placement was 50% (n=25/50). Technical failures were due to failure to identify the ureteric orifice (n=22), failure to cross the stricture (n=1), failure to pass the stent (n=1) and failure to pass a 4 Fr catheter (n=1). Antegrade placement was attempted in 25 ureters with a success rate of 96% (n=24/25). Failure in the one case was due to inability to cross an upper third stricture secondary to pyeloureteritis cystica. CONCLUSION: It is suggested that retrograde route should be the initial approach if imaging shows no involvement of ureteric orifice (UO), when nephrostomy is technically very difficult or in cases of solitary kidney. The antegrade route is preferred if imaging shows tumour occlusion of the UO or if there is a tight stricture very close to the uretero-vesical junction (UVJ) making purchase within the ureter difficult for crossing the stricture

  7. Palliation of malignant gastric obstruction : fluoroscopic guided covered metallic stent placement

    International Nuclear Information System (INIS)

    Lee, Jeong Min; Han, Young Min; Kim, Chong Soo; Lee, Sang Yong; Choi, Ki Chul; Lee, Soo Tak; Han, Hyun Young

    2000-01-01

    To demonstrate the feasibility and clinical efficacy of self-expanding, covered metallic stent placement for the palliative treatment of malignant gastric obstruction. Under fluoroscopic guidance, the placement of self-expanding, covered stents was attempted in 23 patients (age range, 31-78 years) with inoperable or recurrent gastric malignancies. All 23 suffered dysphagia and/or vomiting after the ingestion of soft foods, or swallowing difficulty. Three different types of self-expanding, covered metallic stents were used and in all patients, these were placed perorally using over the guide wire technique. Success was defined both technically and clinically. Stent placement was technically successful in 19 patients (82.6%) but because the guidewire failed to successfully negotiate the sites at which there was obstruction, was unsuccessful in four (17.4%). Stent placement was well tolerated in all patients except one, in whom an acutely angled efferent loop from remnant stomach was present. In this case, stent placement required a strong metallic guidewire. After placement, 17 of the 19 patients (89.5%) were able to ingest solid and/or soft foods without dysphagia and showed a markedly decreased incidence of vomiting. Two others showed some improvement in the frequency of vomiting but were able to ingest only a liquid diet. In one patient, the stent migrated two days after the procedure. During the follow-up period of 2-7 months (mean, 74 days), there were no clinically significant complications. For the short-term palliative treatment of patients with gastric inlet or outlet obstruction, the placement of self-expanding metallic stents has proven relatively easy and safe, as well as reasonably effective. (author)

  8. Efficient placement of structural dynamics sensors on the space station

    Science.gov (United States)

    Lepanto, Janet A.; Shepard, G. Dudley

    1987-01-01

    System identification of the space station dynamic model will require flight data from a finite number of judiciously placed sensors on it. The placement of structural dynamics sensors on the space station is a particularly challenging problem because the station will not be deployed in a single mission. Given that the build-up sequence and the final configuration for the space station are currently undetermined, a procedure for sensor placement was developed using the assembly flights 1 to 7 of the rephased dual keel space station as an example. The procedure presented approaches the problem of placing the sensors from an engineering, as opposed to a mathematical, point of view. In addition to locating a finite number of sensors, the procedure addresses the issues of unobserved structural modes, dominant structural modes, and the trade-offs involved in sensor placement for space station. This procedure for sensor placement will be applied to revised, and potentially more detailed, finite element models of the space station configuration and assembly sequence.

  9. Accounting for L2 learners’ errors in word stress placement

    Directory of Open Access Journals (Sweden)

    Clara Herlina Karjo

    2016-01-01

    Full Text Available Stress placement in English words is governed by highly complicated rules. Thus, assigning stress correctly in English words has been a challenging task for L2 learners, especially Indonesian learners since their L1 does not recognize such stress system. This study explores the production of English word stress by 30 university students. The method used for this study is immediate repetition task. Participants are instructed to identify the stress placement of 80 English words which are auditorily presented as stimuli and immediately repeat the words with correct stress placement. The objectives of this study are to find out whether English word stress placement is problematic for L2 learners and to investigate the phonological factors which account for these problems. Research reveals that L2 learners have different ability in producing the stress, but three-syllable words are more problematic than two-syllable words. Moreover, misplacement of stress is caused by, among others, the influence of vowel lenght and vowel height.

  10. Placement shift, sibling relationship quality, and child outcomes in foster care: a controlled study.

    Science.gov (United States)

    Linares, L Oriana; Li, MiMin; Shrout, Patrick E; Brody, Gene H; Pettit, Gregory S

    2007-12-01

    Sibling unity during family transitions is considered a protective factor for child behavior problems, but there is little empirical support for the widespread child protection policy of placing siblings together in foster care. In a prospective study of 156 maltreated children, siblings were classified in 1 of 3 placement groups: continuously together (n = 110), continuously apart (n = 22), and disrupted placement (siblings placed together were separated; n = 24). Changes in child adjustment as a function of sibling relationship and placement group were examined. Sibling positivity predicted lower child problems at follow-up (about 14 months later), while sibling negativity predicted higher child problems. Placement group did not affect child behavior problems at follow-up; however, compared to siblings in continuous placement (either together or apart), siblings in disrupted placement with high initial behavior problems were rated as having fewer problems at follow-up, while siblings in disrupted placement with low initial behavior problems were rated as having more problems at follow-up. These findings highlight the importance of considering relationships between siblings and the risk that one poses to another before early placement decisions are made.

  11. Intraoperative Factors that Predict the Successful Placement of Essure Microinserts.

    Science.gov (United States)

    Arthuis, Chloé J; Simon, Emmanuel G; Hébert, Thomas; Marret, Henri

    To determine whether the number of coils visualized in the uterotubal junction at the end of hysteroscopic microinsert placement predicts successful tubal occlusion. Cohort retrospective study (Canadian Task Force classification II-2). Department of obstetrics and gynecology in a teaching hospital. One hundred fifty-three women underwent tubal microinsert placement for permanent birth control from 2010 through 2014. The local institutional review board approved this study. Three-dimensional transvaginal ultrasound (3D TVU) was routinely performed 3 months after hysteroscopic microinsert placement to check position in the fallopian tube. The correlation between the number of coils visible at the uterotubal junction at the end of the hysteroscopic microinsert placement procedure and the device position on the 3-month follow-up 3D TVU in 141 patients was evaluated. The analysis included 276 microinserts placed during hysteroscopy. The median number of coils visible after the hysteroscopic procedure was 4 (interquartile range, 3-5). Devices for 30 patients (21.3%) were incorrectly positioned according to the 3-month follow-up 3D TVU, and hysterosalpingography was recommended. In those patients the median number of coils was in both the right (interquartile range, 2-4) and left (interquartile range, 1-3) uterotubal junctions. The number of coils visible at the uterotubal junction at the end of the placement procedure was the only factor that predicted whether the microinsert was well positioned at the 3-month 3D TVU confirmation (odds ratio, .44; 95% confidence interval, .28-.63). When 5 or more coils were visible, no incorrectly placed microinsert could be seen on the follow-up 3D TVU; the negative predictive value was 100%. No pregnancies were reported. The number of coils observed at the uterotubal junction at the time of microinsert placement should be considered a significant predictive factor of accurate and successful microinsert placement. Copyright © 2017

  12. Occupational therapy students' contribution to occasions of service during practice placements in health settings.

    Science.gov (United States)

    Rodger, Sylvia; Stephens, Elizabeth; Clark, Michele; Ash, Susan; Graves, Nicholas

    2011-12-01

    Currently in the Australian higher education sector, the productivity benefits of occupational therapy clinical education placements are a contested issue. This article will report results of a study that developed a methodology for documenting time use during placements and investigated the productivity changes associated with occupational therapy clinical education placements in Queensland, Australia. Supervisors' and students' time use during placements and how this changed for supervisors compared to pre- and post-placement is also presented. Using a cohort survey design, participants were students from two Queensland universities, and their supervisors employed by Queensland Health. Time use was recorded in 30 minute blocks according to particular categories. There was a significant increase in supervisors' time spent in patient care activities (F = 94.011(2,12.37 df) , P increasing between pre- and during placement (P = 0.028). There was a significant decrease in supervisors' time spent in placement activities (F = 5.133(2,19.18 df) , P = 0.016) from during to post-placement. Students spent more time than supervisors in patient care activities while on placement. A novel method for reporting productivity and time-use changes during clinical education programs for occupational therapy has been applied. Supervisors spent considerable time in assessing and managing students and their clinical education role should be seen as core business in standard occupational therapy practice. This paper will contribute to future assessments of the economic impact of student placements for allied health disciplines. © 2011 The Authors. Australian Occupational Therapy Journal © 2011 Occupational Therapy Australia.

  13. Speeding Up FPGA Placement via Partitioning and Multithreading

    Directory of Open Access Journals (Sweden)

    Cristinel Ababei

    2009-01-01

    placement subproblems are created by partitioning and then processed concurrently by multiple worker threads that are run on multiple cores of the same processor. Our main goal is to investigate the speedup that can be achieved with this simple approach compared to previous approaches that were based on distributed computing. The new hybrid parallel placement algorithm achieves an average speedup of 2.5× using four worker threads, while the total wire length and circuit delay after routing are minimally degraded.

  14. 37 CFR 211.6 - Methods of affixation and placement of mask work notice.

    Science.gov (United States)

    2010-07-01

    ... placement of mask work notice. 211.6 Section 211.6 Patents, Trademarks, and Copyrights COPYRIGHT OFFICE, LIBRARY OF CONGRESS COPYRIGHT OFFICE AND PROCEDURES MASK WORK PROTECTION § 211.6 Methods of affixation and placement of mask work notice. (a) General. (1) This section specifies methods of affixation and placement...

  15. Optimizing 4DCBCT projection allocation to respiratory bins

    International Nuclear Information System (INIS)

    O’Brien, Ricky T; Kipritidis, John; Shieh, Chun-Chien; Keall, Paul J

    2014-01-01

    4D cone beam computed tomography (4DCBCT) is an emerging image guidance strategy used in radiotherapy where projections acquired during a scan are sorted into respiratory bins based on the respiratory phase or displacement. 4DCBCT reduces the motion blur caused by respiratory motion but increases streaking artefacts due to projection under-sampling as a result of the irregular nature of patient breathing and the binning algorithms used. For displacement binning the streak artefacts are so severe that displacement binning is rarely used clinically. The purpose of this study is to investigate if sharing projections between respiratory bins and adjusting the location of respiratory bins in an optimal manner can reduce or eliminate streak artefacts in 4DCBCT images. We introduce a mathematical optimization framework and a heuristic solution method, which we will call the optimized projection allocation algorithm, to determine where to position the respiratory bins and which projections to source from neighbouring respiratory bins. Five 4DCBCT datasets from three patients were used to reconstruct 4DCBCT images. Projections were sorted into respiratory bins using equispaced, equal density and optimized projection allocation. The standard deviation of the angular separation between projections was used to assess streaking and the consistency of the segmented volume of a fiducial gold marker was used to assess motion blur. The standard deviation of the angular separation between projections using displacement binning and optimized projection allocation was 30%–50% smaller than conventional phase based binning and 59%–76% smaller than conventional displacement binning indicating more uniformly spaced projections and fewer streaking artefacts. The standard deviation in the marker volume was 20%–90% smaller when using optimized projection allocation than using conventional phase based binning suggesting more uniform marker segmentation and less motion blur. Images

  16. Volunteering and overseas placements in the NHS: a survey of current activity.

    Science.gov (United States)

    Chatwin, John; Ackers, Louise

    2016-10-19

    The study aimed to establish current levels of overseas volunteering and placement activity across all staff grades within the National Health Service (NHS) in the North West of England. Cross-sectional survey. Descriptive statistics. 4 main regional hospitals in the North West of England, and additional NHS staff training events. Convenience sample of NHS staff (n=911). 911 NHS staff took part in the survey. The medical and dental staff group returned the highest number of responses (32.1%). 42% of staff reported some form of overseas volunteering or placement experience. Most staff took an international placement as students (33.6% men; 40.6% women). Medium-term placements were undertaken by 46.7% of men, and 52.5% of women. Settlement stays (ie, over 1 year) were reported by 7.6% men, and 8.3% women). The majority of respondents engaged in international placement were from the age groups incorporating 'below 25' to '41-50' (74%). Multiple placement experiences were uncommon: 2.5% of respondents reported three periods of overseas activity, and 1.5% reported four. All those with multiple placement experience came from the staff groups incorporating midwife/nurse/health visitor, and medical and dental. This survey captured a snapshot of current levels of volunteering and overseas placement activity across NHS staff grades in the North West. Owing to relatively homogenous organisational structures, findings are likely to broadly represent the position across the organisation as a whole. Although some degree of overseas placement activity is undertaken by a relatively high proportion of NHS staff, such activity is currently heavily skewed towards higher clinical staff grades. Significant numbers of allied health professionals and equivalent non-clinical cadres also report overseas experience, and we anticipate that the numbers will continue to rise if current policy initiatives gain momentum. Published by the BMJ Publishing Group Limited. For permission to use

  17. Selective Placement Program Coordinator (SPPC) Directory

    Data.gov (United States)

    Office of Personnel Management — List of the Selective Placement Program Coordinators (SPPC) in Federal agencies, updated as needed. Users can filter the list by choosing a state and/or agency name.

  18. Mode of communication and classroom placement impact on speech intelligibility.

    Science.gov (United States)

    Tobey, Emily A; Rekart, Deborah; Buckley, Kristi; Geers, Ann E

    2004-05-01

    To examine the impact of classroom placement and mode of communication on speech intelligibility scores in children aged 8 to 9 years using multichannel cochlear implants. Classroom placement (special education, partial mainstream, and full mainstream) and mode of communication (total communication and auditory-oral) reported via parental rating scales before and 4 times after implantation were the independent variables. Speech intelligibility scores obtained at 8 to 9 years of age were the dependent variables. The study included 131 congenitally deafened children between the ages of 8 and 9 years who received a multichannel cochlear implant before the age of 5 years. Higher speech intelligibility scores at 8 to 9 years of age were significantly associated with enrollment in auditory-oral programs rather than enrollment in total communication programs, regardless of when the mode of communication was used (before or after implantation). Speech intelligibility at 8 to 9 years of age was not significantly influenced by classroom placement before implantation, regardless of mode of communication. After implantation, however, there were significant associations between classroom placement and speech intelligibility scores at 8 to 9 years of age. Higher speech intelligibility scores at 8 to 9 years of age were associated with classroom exposure to normal-hearing peers in full or partial mainstream placements than in self-contained, special education placements. Higher speech intelligibility scores in 8- to 9-year-old congenitally deafened cochlear implant recipients were associated with educational settings that emphasize oral communication development. Educational environments that incorporate exposure to normal-hearing peers were also associated with higher speech intelligibility scores at 8 to 9 years of age.

  19. Estimation of optimal nasotracheal tube depth in adult patients.

    Science.gov (United States)

    Ji, Sung-Mi

    2017-12-01

    The aim of this study was to estimate the optimal depth of nasotracheal tube placement. We enrolled 110 patients scheduled to undergo oral and maxillofacial surgery, requiring nasotracheal intubation. After intubation, the depth of tube insertion was measured. The neck circumference and distances from nares to tragus, tragus to angle of the mandible, and angle of the mandible to sternal notch were measured. To estimate optimal tube depth, correlation and regression analyses were performed using clinical and anthropometric parameters. The mean tube depth was 28.9 ± 1.3 cm in men (n = 62), and 26.6 ± 1.5 cm in women (n = 48). Tube depth significantly correlated with height (r = 0.735, P < 0.001). Distances from nares to tragus, tragus to angle of the mandible, and angle of the mandible to sternal notch correlated with depth of the endotracheal tube (r = 0.363, r = 0.362, and r = 0.546, P < 0.05). The tube depth also correlated with the sum of these distances (r = 0.646, P < 0.001). We devised the following formula for estimating tube depth: 19.856 + 0.267 × sum of the three distances (R 2 = 0.432, P < 0.001). The optimal tube depth for nasotracheally intubated adult patients correlated with height and sum of the distances from nares to tragus, tragus to angle of the mandible, and angle of the mandible to sternal notch. The proposed equation would be a useful guide to determine optimal nasotracheal tube placement.

  20. Substantial changes in mastery perceptions of dementia caregivers with the placement of a care recipient.

    Science.gov (United States)

    Infurna, Frank J; Gerstorf, Denis; Zarit, Steven H

    2013-03-01

    The current study examined how a key component of caregiving stress processes, global mastery perceptions, changes with placing the care recipient in a nursing home or institution. We also explored the role of primary stressors in accounting for mastery changes with placement and whether characteristics of the caregiver and care recipient moderate reactions to placement. We applied multiphase growth curve models to prospective longitudinal data from 271 caregivers in the Caregiver Stress and Coping Study who experienced placement of their care recipient. Using a time-to/from-placement metric, we found that caregivers typically experienced declines in mastery preceding placement, followed by a significant increase within 1 year after placement and further increases thereafter. Corresponding changes in primary stressors (role overload) mediated the placement-related increase in mastery. Caregivers who reported more depressive symptoms and activities of daily living/instrumental activities of daily living dependencies of the care recipient were more likely to experience larger placement-related increases in mastery perceptions. Our findings suggest that placement alters psychological resources of caregivers and this effect is driven by corresponding changes in primary stressors. Findings also underscore the importance of examining change processes across salient life events and transitions.

  1. Private Placements as Sources of Long Term Funds for publicly ...

    African Journals Online (AJOL)

    Thereafter, an overview of the concept of private placement is given to enable a better appreciation of its unique role in raising funds for organizations that are not publicly quoted in a registered stock exchange. It concludes with an exposition of the problems of allowing private placements for publicly quoted firms.

  2. Advanced Placement U.S. History: What Happens after the Examination?

    Science.gov (United States)

    Henry, Michael

    1991-01-01

    Discusses a survey of 56 advanced placement (AP) U.S. history teachers. Explores the scope of AP history and types of posttest activities used after Advanced Placement examinations. Concludes that public school courses developed more deeply into post-1960 events than the private schools did. Describes movies, debates, simulations, and local…

  3. Product placement in Hollywood blockbusters: brand recognition and attitude towards the practice : A case study on product placement attitudes among international students

    OpenAIRE

    Tiavin, Kiril; Köllisch, Frederic; Nurminen, Vili

    2015-01-01

    Background: Advertising channels in today's marketplace are becoming more limited with the development of ad-free sources of entertainment. The phenomenon of product placements is therefore becoming one of the most important sources for advertising in media. Especially film productions have turned into a canvas for companies to display their brands upon. Purpose: The purpose of this thesis was to investigate the case of product placements in Hollywood blockbuster movies. In particular, brand ...

  4. Pathologic Markers Determining Prognosis in Patients with Treated or Healing Giant Cell Arteritis.

    Science.gov (United States)

    Sultan, Harris; Smith, Stacy V; Lee, Andrew G; Chévez-Barrios, Patricia

    2018-06-08

    To provide quantitative evidence linking the Cluster of Differentiation-68 (CD68)+ macrophage-marker found on temporal artery biopsies (TABs) with disease prognosis. Retrospective, cross-sectional study METHODS: We examined 42 consecutive patients who had undergone unilateral TABs at a single hospital in 2015. Clinical data, laboratory data, and histopathologic features of TABs were recorded. clinical diagnosis of giant cell arteritis (GCA) with TAB performed at the same center. CD68 immunohistochemistry was used to label macrophages in the TABs. multiple logistic regression and bivariate comparisons to measure the association between CD68+ cells per histologic section with placement on immunomodulatory therapy (IMT). Twenty seven patients were females (64%), with a mean age of 72 (standard deviation [S.D.] ±7.7). Eleven patients (26%) were placed on IMT, 17 (40%) had disease recurrence during steroid taper, and 25 (60%) were referred to rheumatology. Of 42 biopsies, 35 underwent staining with CD68 to confirm active inflammation in suspicious, but not diagnostic, specimens. Patients eventually placed on IMT had increased CD68+ cells/slice compared to those not on IMT (median 5.00 [25-75 th quartile 2.00-7.15] vs 1.21 [0.38-2.57], p=0.031, respectively). A receiver operating characteristics (ROC) curve demonstrates that 2.17 CD68+ cells/slice predicts placement on IMT with an odds ratio of 1.54 (95% C.I. 1.02-2.33, p=0.038). Patients refractory to initial steroid tapers and those eventually placed on IMT had increased CD68 cells/section. CD68+ macrophages and their location on the internal elastic lamina may predict disease severity in patients with presumed GCA. Our results suggest that this marker may expedite patient triaging to alternate treatment to the usual steroid therapy. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. Restrictive educational placements increase adolescent risks for students with early-starting conduct problems.

    Science.gov (United States)

    Powers, Christopher J; Bierman, Karen L; Coffman, Donna L

    2016-08-01

    Students with early-starting conduct problems often do poorly in school; they are disproportionately placed in restrictive educational placements outside of mainstream classrooms. Although intended to benefit students, research suggests that restrictive placements may exacerbate the maladjustment of youth with conduct problems. Mixed findings, small samples, and flawed designs limit the utility of existing research. This study examined the impact of restrictive educational placements on three adolescent outcomes (high school noncompletion, conduct disorder, depressive symptoms) in a sample of 861 students with early-starting conduct problems followed longitudinally from kindergarten (age 5-6). Causal modeling with propensity scores was used to adjust for confounding factors associated with restrictive placements. Analyses explored the timing of placement (elementary vs. secondary school) and moderation of impact by initial problem severity. Restrictive educational placement in secondary school (but not in elementary school) was iatrogenic, increasing the risk of high school noncompletion and the severity of adolescent conduct disorder. Negative effects were amplified for students with conduct problem behavior with less cognitive impairment. To avoid harm to students and to society, schools must find alternatives to restrictive placements for students with conduct problems in secondary school, particularly when these students do not have cognitive impairments that might warrant specialized educational supports. © 2015 Association for Child and Adolescent Mental Health.

  6. 25 CFR 26.11 - What type of Job Placement and Training assistance may be approved?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false What type of Job Placement and Training assistance may be... JOB PLACEMENT AND TRAINING PROGRAM General Applicability § 26.11 What type of Job Placement and... supplemental assistance that supports job placement or training activities (see subpart B of this part for Job...

  7. A shared experience of fragmentation: making sense of foster placement breakdown.

    Science.gov (United States)

    Rostill-Brookes, Helen; Larkin, Michael; Toms, Amy; Churchman, Clare

    2011-01-01

    Multiple placement transitions have been associated with poorer psychosocial outcomes for children growing up in local authority care. However, although there is an expanding literature examining the risk and protective factors connected with placement breakdown, very few studies have explored the quality of the move experience for those most closely involved with it. Our study considered how young people, foster carers and social workers made sense of unplanned placements' endings. Bringing together the lived experiences of these key stakeholders in the placement system added a novel dimension to existing research knowledge. What emerged from our analysis was evidence of a pervasive and shared emotional experience; all of the participants were affected by the breakdown irrespective of age, experience, or professional role. However, despite many commonalities, there was also a strong sense of fragmentation between the groups, which was characterised by discourses of mistrust and miscommunication. This meant that emotional reactions to the breakdown were often suppressed or dismissed, resentments built-up and attempts to find a solution were thwarted by silence or angry recrimination. These findings raise real challenges for practice and policy development. In particular, they stress the importance of shared and meaningful dialogue between all key stakeholders within the social care system, the need for more effective and timely support when placements are in crisis and opportunities for those most closely involved with the placement breakdown to process the emotional experience.

  8. Making short-term international medical volunteer placements work: a qualitative study.

    Science.gov (United States)

    Elnawawy, Omnia; Lee, Andrew C K; Pohl, Gerda

    2014-06-01

    International medical volunteering has grown in recent decades. It has the potential to benefit and harm the volunteer and host countries; but there is a paucity of literature on the impacts of international medical volunteering and a need to find ways to optimise the benefits of such placements. In this study, one example of international medical volunteering was examined involving British GPs on short-term placements in Nepal. The intention was to explore the expectations and experiences of the local health workers, volunteers, and host organisation to try and understand what makes volunteer placements work. Qualitative study of key informant interviews. Stakeholders of a short-term international medical volunteer (IMV) placement programme in Nepal. Key informant interviews were carried out via face-to-face or telephone/internet interviews with five previous volunteers, three representatives from a non-governmental organisation providing placements, and five local health workers in Nepal who had had contact with the IMVs. Interviews were recorded, transcribed, and analysed using standard thematic framework approaches. All the stakeholders had their own specific motives for participating in the IMV programme. The relationship between volunteers and the Nepalese health workers was complex and characterised by discrepant and occasionally unrealistic expectations. Managing these different expectations was challenging. Contextual issues and cultural differences are important considerations in medical volunteer programmes, and this study highlights the importance of robust preparation pre-placement for the volunteer and host to ensure positive outcomes. © British Journal of General Practice 2014.

  9. Radiography students' clinical placement experiences in MRI: A phenomenological study

    International Nuclear Information System (INIS)

    Portanier Mifsud, Claude; Castillo, Joseph; Portelli, Jonathan Loui

    2015-01-01

    Purpose: The purpose of this study was to gain an insight into radiography students' clinical practice experiences within an MRI unit of a large teaching hospital in Malta. The underlying objectives of the study were to identify and explore the descriptions and meanings of the MRI clinical experiences of students. Methods: Five students, independently undergoing their clinical placements in MRI were asked to write a diary about their daily experiences. Each student then participated in a follow up interview. Data analysis was based on Husserls' phenomenological approach. Results: Eight themes emerged from the data analysed. Students described their experience as one mainly based on observation, where, during their placements, they observed radiographers at work. In this respect, students described their experience as lacking ‘hands on practice’. Students indicated that they felt uncomfortable, unsupervised and unwelcome most of the time. They also expressed the need to feel useful and part of the MRI team during their placement and so they tried to help the team in areas such as patient screening. This helped them build confidence. Learning in MRI was specifically based on the university tasks prescribed and possibly there was no motivation to learn more. The students also described their experience as varied and different when compared to other placements. Conclusion: This study provides a rare insight into radiography students' placement experiences in MRI and should enable the supervising radiographer and educator to obtain a deeper appreciation of the clinical placement experience

  10. Angioplasty and stent placement - peripheral arteries

    Science.gov (United States)

    ... medlineplus.gov/ency/article/007393.htm Angioplasty and stent placement - peripheral arteries To use the sharing features ... inside the arteries and block blood flow. A stent is a small, metal mesh tube that keeps ...

  11. Something has shifted: Nursing students' global perspective following international clinical placements.

    Science.gov (United States)

    Gower, Shelley; Duggan, Ravani; Dantas, Jaya A R; Boldy, Duncan

    2017-10-01

    To examine understandings of global health issues among nursing students following participation in an international clinical placement during their pre-registration university education. Universities use international clinical placements, especially in developing countries, to develop cultural awareness in students; however, little is known about the longer term influences on students' understandings of global nursing. A retrospective cross-sectional design was used, using an exploratory, descriptive qualitative approach. Individual semi-structured interviews were conducted in 2014 with a purposive sample of 25 pre-registration nursing students from four Western Australian universities who undertook clinical placements across five countries. Data were analysed using inductive thematic analysis. Findings highlight that students developed new understandings around health systems including fragility of resource access, differences in clinical practice and variances in nursing roles between settings. Students also experienced challenges but were able to appreciate alternative world viewpoints. International clinical placements can develop greater awareness and help students form realistic strategies for using their nursing skills globally. Pre-placement training in cultural awareness and health system realities, along with strong supervisory support, is critical to success. © 2017 John Wiley & Sons Ltd.

  12. Placement Evaluations and Remedial Education: Are Students Shopping for Bargains?

    Science.gov (United States)

    Fletcher, Stephen H.

    2014-01-01

    The purpose of this study is to provide evidence that students may be doing comparison shopping when it comes to community college placement in English and mathematics courses. Comparisons may occur because of the difference in the placement process across campuses and the variation in the levels of developmental education offered. The…

  13. 34 CFR 300.325 - Private school placements by public agencies.

    Science.gov (United States)

    2010-07-01

    ... Programs, and Educational Placements Development of Iep § 300.325 Private school placements by public... child to, a private school or facility, the agency must initiate and conduct a meeting to develop an IEP... disability enters a private school or facility, any meetings to review and revise the child's IEP may be...

  14. 25 CFR 26.3 - What is the purpose of the Job Placement and Training Program?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false What is the purpose of the Job Placement and Training... PLACEMENT AND TRAINING PROGRAM General Applicability § 26.3 What is the purpose of the Job Placement and Training Program? The purpose of the Job Placement and Training Program is to assist eligible applicants to...

  15. [Eleven Patients with Gastric Cancer Who Received Chemotherapy after Stent Placement for Gastric Outlet Obstruction].

    Science.gov (United States)

    Endo, Shunji; Nakagawa, Tomo; Konishi, Ken; Ikenaga, Masakazu; Ohta, Katsuya; Nakashima, Shinsuke; Matsumoto, Kenichi; Nishikawa, Kazuhiro; Ohmori, Takeshi; Yamada, Terumasa

    2017-01-01

    Endoscopic placement of self-expandable metallic stents is reportedly effective for gastric outlet obstructions due to advanced gastric cancer, and is less invasive than gastrojejunostomy. For patients who have good performance status, we administer chemotherapy after stent placement, although the safety and feasibility of this chemotherapy have not yet been discussed in full. Between 2011 and 2015, 15 patients at our institution underwent endoscopic gastroduodenal stent placement for gastric outlet obstruction due to gastric cancer. Eleven of these patients were administered chemotherapy after stent placement. In our case series, we did not observe any specific adverse event caused by stent placement plus chemotherapy. Adverse events after chemotherapy included anemia of CTCAE Grade 3 in 7 patients. Stent-in-stent placement was needed in 2 patients. Neither stent migration nor perforation was observed. Therefore, chemotherapy after stent placement for gastric outlet obstruction due to gastric cancer was considered safe and feasible. Stent placement is useful not only as palliative care for patients with terminal-stage disease, but also as one of the multimodal therapeutic strategies for gastric cancer.

  16. Wireless Sensor Network Optimization: Multi-Objective Paradigm.

    Science.gov (United States)

    Iqbal, Muhammad; Naeem, Muhammad; Anpalagan, Alagan; Ahmed, Ashfaq; Azam, Muhammad

    2015-07-20

    Optimization problems relating to wireless sensor network planning, design, deployment and operation often give rise to multi-objective optimization formulations where multiple desirable objectives compete with each other and the decision maker has to select one of the tradeoff solutions. These multiple objectives may or may not conflict with each other. Keeping in view the nature of the application, the sensing scenario and input/output of the problem, the type of optimization problem changes. To address different nature of optimization problems relating to wireless sensor network design, deployment, operation, planing and placement, there exist a plethora of optimization solution types. We review and analyze different desirable objectives to show whether they conflict with each other, support each other or they are design dependent. We also present a generic multi-objective optimization problem relating to wireless sensor network which consists of input variables, required output, objectives and constraints. A list of constraints is also presented to give an overview of different constraints which are considered while formulating the optimization problems in wireless sensor networks. Keeping in view the multi facet coverage of this article relating to multi-objective optimization, this will open up new avenues of research in the area of multi-objective optimization relating to wireless sensor networks.

  17. Wireless Sensor Network Optimization: Multi-Objective Paradigm

    Science.gov (United States)

    Iqbal, Muhammad; Naeem, Muhammad; Anpalagan, Alagan; Ahmed, Ashfaq; Azam, Muhammad

    2015-01-01

    Optimization problems relating to wireless sensor network planning, design, deployment and operation often give rise to multi-objective optimization formulations where multiple desirable objectives compete with each other and the decision maker has to select one of the tradeoff solutions. These multiple objectives may or may not conflict with each other. Keeping in view the nature of the application, the sensing scenario and input/output of the problem, the type of optimization problem changes. To address different nature of optimization problems relating to wireless sensor network design, deployment, operation, planing and placement, there exist a plethora of optimization solution types. We review and analyze different desirable objectives to show whether they conflict with each other, support each other or they are design dependent. We also present a generic multi-objective optimization problem relating to wireless sensor network which consists of input variables, required output, objectives and constraints. A list of constraints is also presented to give an overview of different constraints which are considered while formulating the optimization problems in wireless sensor networks. Keeping in view the multi facet coverage of this article relating to multi-objective optimization, this will open up new avenues of research in the area of multi-objective optimization relating to wireless sensor networks. PMID:26205271

  18. This is advertising! Effects of disclosing television brand placement on adolescents

    NARCIS (Netherlands)

    Reijmersdal, E.A. van; Boerman, S.C.; Buijzen, M.A.; Rozendaal, E.

    2017-01-01

    As heavy media users, adolescents are frequently exposed to embedded advertising formats such as brand placements. Because this may lead to unwitting persuasion, regulations prescribe disclosure of brand placements. This study aimed to increase our understanding of the effects of disclosing

  19. This is Advertising! Effects of Disclosing Television Brand Placement on Adolescents

    NARCIS (Netherlands)

    van Reijmersdal, E.A.; Boerman, S.C.; Buijzen, M.; Rozendaal, E.

    As heavy media users, adolescents are frequently exposed to embedded advertising formats such as brand placements. Because this may lead to unwitting persuasion, regulations prescribe disclosure of brand placements. This study aimed to increase our understanding of the effects of disclosing

  20. Cancer stem cell markers in common cancers - therapeutic implications

    DEFF Research Database (Denmark)

    Klonisch, Thomas; Wiechec, Emilia; Hombach-Klonisch, Sabine

    2008-01-01

    Rapid advance in the cancer stem cell field warrants optimism for the development of more reliable cancer therapies within the next 2-3 decades. Below, we characterize and compare the specific markers that are present on stem cells, cancer cells and cancer stem cells (CSC) in selected tissues...