Menotti, J; Porcher, R; Ribaud, P; Lacroix, C; Jolivet, V; Hamane, S; Derouin, F
2010-09-01
In order to provide a statistically based evaluation of the incidence of invasive aspergillosis (IA) over time, we applied the cumulative sums (CUSUM) methodology, which was developed for quality control and has already been applied for the surveillance of hospital-acquired infections. Cases of IA were recorded during a 5-year period. Incidence rates of cases assumed to be hospital-acquired, i.e. nosocomial IA (NIA), were analysed using CUSUM tests. Relationships between NIA, fungal contamination and construction or renovation work were tested using time-series methods. Between January 2002 and December 2006, 81 cases of NIA were recorded. CUSUM analysis of NIA incidence showed no significant deviation from the expected monthly number of cases until August 2005, and then the CUSUM crossed the decision limit, i.e. identified a significant increase in NIA as compared with the reference period (January 2002 to December 2004). Up to April 2006, the learning-curve CUSUM stayed over its limit, supporting an ongoing outbreak involving 24 patients, and then it significantly decreased in May 2006. Follow-up after May 2006 indicated no out-of-control situation, supporting a return to the baseline situation. In haematology wards, significant links were found between NIA incidence and fungal contamination of several sites at each ward (mainly unprotected common sites). An environmental source of contamination could be suspected, but no significant relationship was found between NIA incidence and ongoing construction or renovation. In conclusion, the CUSUM test proved to be well suited for real-time monitoring of NIA and for early identification and follow-up of an outbreak.
Dexter, Franklin; Ledolter, Johannes; Hindman, Bradley J
2014-09-01
We describe our experiences in using Bernoulli cumulative sum (CUSUM) control charts for monitoring clinician performance. The supervision provided by each anesthesiologist is evaluated daily by the Certified Registered Nurse Anesthetists (CRNAs) and/or anesthesia residents with whom they work. Each of 9 items is evaluated (1 = never, 2 = rarely, 3 = frequently, 4 = always). The score is the mean of the 9 responses. Choosing thresholds for low scores is straightforward, CUSUM detection of low scores was within 50 ± 14 (median ± quartile deviation) days rather than 182 days without use of CUSUM. The true positive detection of anesthesiologists with incidences of low scores greater than the chosen "out-of-control" rate was 14 of 14. The false-positive detection rate was 0 of 29. This CUSUM performance exceeded that of Shewhart individual control charts, for which the smallest threshold sufficiently large to detect 14 of 14 true positives had false-positive detection of 16 of 29 anesthesiologists. The Bernoulli CUSUM assumes that scores are known right away, which is untrue. However, CUSUM performance was insensitive to this assumption. The Bernoulli CUSUM assumes statistical independence of scores, which also is untrue. For example, when an evaluation of an anesthesiologist 1 day by a CRNA had a low score, there was an increased chance that another CRNA working in a different operating room on the same day would also give that same anesthesiologist a low score (P CUSUM, such that detection is more likely. This is an advantage for our continual process improvement application since it flags individuals for further evaluation by managers while maintaining confidentiality of raters.
Kollmann-Camaiora, A; Brogly, N; Alsina, E; Gilsanz, F
2017-10-01
Although ultrasound is a basic competence for anaesthesia residents (AR) there is few data available on the learning process. This prospective observational study aims to assess the learning process of ultrasound-guided continuous femoral nerve block and to determine the number of procedures that a resident would need to perform in order to reach proficiency using the cumulative sum (CUSUM) method. We recruited 19 AR without previous experience. Learning curves were constructed using the CUSUM method for ultrasound-guided continuous femoral nerve block considering 2 success criteria: a decrease of pain score>2 in a [0-10] scale after 15minutes, and time required to perform it. We analyse data from 17 AR for a total of 237 ultrasound-guided continuous femoral nerve blocks. 8/17 AR became proficient for pain relief, however all the AR who did more than 12 blocks (8/8) became proficient. As for time of performance 5/17 of AR achieved the objective of 12minutes, however all the AR who did more than 20 blocks (4/4) achieved it. The number of procedures needed to achieve proficiency seems to be 12, however it takes more procedures to reduce performance time. The CUSUM methodology could be useful in training programs to allow early interventions in case of repeated failures, and develop competence-based curriculum. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.
A Parametric Cumulative Sum Statistic for Person Fit
Armstrong, Ronald D.; Shi, Min
2009-01-01
This article develops a new cumulative sum (CUSUM) statistic to detect aberrant item response behavior. Shifts in behavior are modeled with quadratic functions and a series of likelihood ratio tests are used to detect aberrancy. The new CUSUM statistic is compared against another CUSUM approach as well as traditional person-fit statistics. A…
A Parametric Cumulative Sum Statistic for Person Fit
Armstrong, Ronald D.; Shi, Min
2009-01-01
This article develops a new cumulative sum (CUSUM) statistic to detect aberrant item response behavior. Shifts in behavior are modeled with quadratic functions and a series of likelihood ratio tests are used to detect aberrancy. The new CUSUM statistic is compared against another CUSUM approach as well as traditional person-fit statistics. A…
ON THE IMPROVING OF CUMULATIVE SUM CHART%关于累积和(CUSUM)检验的改进
Institute of Scientific and Technical Information of China (English)
濮晓龙
2003-01-01
对连续检验问题,常用的检测方法有三大类,其一是众所周知的Shewhart控制图,它是最常用的对生产过程进行连续监控的控制方法,不过,如果过程均值有小的漂移(即μ-μo小)时,Shewhart控制图的检验效果不是很好.除了Shewhart控制图外,另有二类常用的控制图法,其一是累积和控制图(CUSUM),由Page[1]基于似然比导出,其二是指数加权移动平均控制图(EWMA),由Roberts[2]给出,它们已被证明在检测小的漂移时效果不错.许多人对CUSUM与EWMA进行了比较,总的来说,最好的CUSUM与最好的EWMA在检测小的漂移方面难分优劣,但CUSUM是由似然比导出的,且其平均运行长度的计算相对来说要简便些,因此,CUSUM在与EWMA的比较中更具优势,应用更广.我们分析了CUSUM的导出过程和公式,指出CUSUM有二个可以进一步改进的方面.在此基础上,我们给出了二个新的累积和检验统计量及其判断准则,它们分别是PCUSUM检验统计量Pn和DCUSUM检验统计量Sn.在连续检验问题中判断一个检验方法好坏的最重要的标准是其平均运行长度,比较标准是:在要求具有相同的受控状态下平均运行长度ARL0的条件下,比较其失控状态下的平均运行长度ARL1,ARL1越小越好.我们对PCUSUM检验和DCUSUM检验都建立了其平均运行长度ARL的计算公式.通过对CUSUM,PCUSUM,DCUSUM的平均运行长度的比较,我们发现,我们提出的新的累积和控制方法确比原来的CUSUM有较大改进.
Enhanced cumulative sum charts for monitoring process dispersion.
Abujiya, Mu'azu Ramat; Riaz, Muhammad; Lee, Muhammad Hisyam
2015-01-01
The cumulative sum (CUSUM) control chart is widely used in industry for the detection of small and moderate shifts in process location and dispersion. For efficient monitoring of process variability, we present several CUSUM control charts for monitoring changes in standard deviation of a normal process. The newly developed control charts based on well-structured sampling techniques - extreme ranked set sampling, extreme double ranked set sampling and double extreme ranked set sampling, have significantly enhanced CUSUM chart ability to detect a wide range of shifts in process variability. The relative performances of the proposed CUSUM scale charts are evaluated in terms of the average run length (ARL) and standard deviation of run length, for point shift in variability. Moreover, for overall performance, we implore the use of the average ratio ARL and average extra quadratic loss. A comparison of the proposed CUSUM control charts with the classical CUSUM R chart, the classical CUSUM S chart, the fast initial response (FIR) CUSUM R chart, the FIR CUSUM S chart, the ranked set sampling (RSS) based CUSUM R chart and the RSS based CUSUM S chart, among others, are presented. An illustrative example using real dataset is given to demonstrate the practicability of the application of the proposed schemes.
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Valentine Christopher SP
2009-01-01
Full Text Available Abstract Background The benefits of sentinel lymph node biopsy (SLNB for breast cancer patients with histologically negative axillary nodes, in whom axillary lymph node dissection (ALND is thereby avoided, are now established. Low false negative rate, certainly with blue dye technique, mostly reflects the established high inherent accuracy of SLNB and low axillary nodal metastatic load (subject to patient selection. SLN identification rate is influenced by volume, injection site and choice of mapping agent, axillary nodal metastatic load, SLN location and skill at axillary dissection. Being more subject to technical failure, SLN identification seems to be a more reasonable variable for learning curve assessment than false negative rate. Methylene blue is as good an SLN mapping agent as Isosulfan blue and is much cheaper. Addition of radio-colloid mapping to blue dye does not achieve a sufficiently higher identification rate to justify the cost. Methylene blue is therefore the agent of choice for SLN mapping in developing countries. The American Society of Breast Surgeons recommends that, for competence, surgeons should perform 20 SLNB but admits that the learning curve with a standardized technique may be "much shorter". One appropriate remedy for this dilemma is to plot individual learning curves. Methods Using methylene blue dye, experienced breast surgeons performed SLNB in selected patients with breast cancer (primary tumor Results The CUSUM plot crossed the SPRT limit line after 8 consecutive, positively identified SLN, signaling achievement of an acceptable level of competence. Conclusion Tabular CUSUM charting, based on a justified choice of parameters, indicates that the learning curve for SLNB using methylene blue dye is completed after 8 consecutive, positively identified SLN. CUSUM charting may be used to plot individual learning curves for trainee surgeons by applying a proxy parameter for failure in the presence of a mentor (such as
East, Jeffrey M; Valentine, Christopher S P; Kanchev, Emil; Blake, Garfield O
2009-01-27
The benefits of sentinel lymph node biopsy (SLNB) for breast cancer patients with histologically negative axillary nodes, in whom axillary lymph node dissection (ALND) is thereby avoided, are now established. Low false negative rate, certainly with blue dye technique, mostly reflects the established high inherent accuracy of SLNB and low axillary nodal metastatic load (subject to patient selection). SLN identification rate is influenced by volume, injection site and choice of mapping agent, axillary nodal metastatic load, SLN location and skill at axillary dissection. Being more subject to technical failure, SLN identification seems to be a more reasonable variable for learning curve assessment than false negative rate. Methylene blue is as good an SLN mapping agent as Isosulfan blue and is much cheaper. Addition of radio-colloid mapping to blue dye does not achieve a sufficiently higher identification rate to justify the cost. Methylene blue is therefore the agent of choice for SLN mapping in developing countries. The American Society of Breast Surgeons recommends that, for competence, surgeons should perform 20 SLNB but admits that the learning curve with a standardized technique may be "much shorter". One appropriate remedy for this dilemma is to plot individual learning curves. Using methylene blue dye, experienced breast surgeons performed SLNB in selected patients with breast cancer (primary tumor chart with sequential probability ratio test (SPRT) limits based on a target identification rate of 85%. The CUSUM plot crossed the SPRT limit line after 8 consecutive, positively identified SLN, signaling achievement of an acceptable level of competence. Tabular CUSUM charting, based on a justified choice of parameters, indicates that the learning curve for SLNB using methylene blue dye is completed after 8 consecutive, positively identified SLN. CUSUM charting may be used to plot individual learning curves for trainee surgeons by applying a proxy parameter for
Nazir, H.Z.; Riaz, M.; Does, R.J.M.M.; Abbas, N.
2013-01-01
Cumulative sum (CUSUM) control charts are very effective in detecting special causes. In general, the underlying distribution is supposed to be normal. In designing a CUSUM chart, it is important to know how the chart will respond to disturbances of normality. The focus of this article is to control
Learning curve of vitrification assessed by cumulative summation test for learning curve (LC-CUSUM).
Dessolle, Lionel; Biau, David J; de Larouzière, Vanina; Ravel, Célia; Antoine, Jean-Marie; Daraï, Emile; Mandelbaum, Jacqueline
2009-09-01
We used the cumulative summation test for learning curve (LC-CUSUM), a specifically designed statistical tool, to evaluate the first 50 procedures performed by a trainee in vitrification and to provide a usable model for monitoring the learning process of this technique. Given the lack of models to evaluate IVF technologies, the CUSUM methodology could prove useful for quality control in laboratories.
Zaman, B.; Riaz, M.; Abbas, N.; Does, R.J.M.M.
2015-01-01
Shewhart, exponentially weighted moving average (EWMA), and cumulative sum (CUSUM) charts are famous statistical tools, to handle special causes and to bring the process back in statistical control. Shewhart charts are useful to detect large shifts, whereas EWMA and CUSUM are more sensitive for smal
Detection of abrupt baseline length changes using cumulative sums
Janssen, Volker
2009-06-01
Dynamic processes are usually monitored by collecting a time series of observations, which is then analysed in order to detect any motion or non-standard behaviour. Geodetic examples include the monitoring of dams, bridges, high-rise buildings, landslides, volcanoes and tectonic motion. The cumulative sum (CUSUM) test is recognised as a popular means to detect changes in the mean and/or the standard deviation of a time series and has been applied to various monitoring tasks. This paper briefly describes the CUSUM technique and how it can be utilised for the detection of small baseline length changes by differencing two perpendicular baselines sharing a common site. A simulation is carried out in order to investigate the expected behaviour of the resulting CUSUM charts for a variety of typical deformation monitoring scenarios. This simulation shows that using first differences (between successive epochs) as input, rather than the original baseline lengths, produces clear peaks or jumps in the differenced CUSUM time series when a sudden change in baseline length occurs. These findings are validated by analysing several GPS baseline pairs of a network deployed to monitor the propagation of an active ice shelf rift on the Amery Ice Shelf, East Antarctica.
Optimality of Non-Restarting CUSUM charts
2012-01-01
We show optimality, in a well-defined sense, using cumulative sum (CUSUM) charts for detecting changes in distributions. We consider a setting with multiple changes between two known distributions. This result advocates the use of non-restarting CUSUM charts with an upper boundary. Typically, after signalling, a CUSUM chart is restarted by setting it to some value below the threshold. A non-restarting CUSUM chart is not reset after signalling; thus is able to signal continuously. Imposing an ...
Using Cumulative Sum Statistics to Detect Inconsistencies in Unproctored Internet Testing
Tendeiro, Jorge N.; Meijer, Rob R.; Schakel, Lolle; Maij-de Meij, Annette M.
2013-01-01
Unproctored Internet Testing (UIT) is becoming more popular in personnel recruitment and selection. A drawback of UIT is that cheating is easy and, therefore, a proctored test is often administered after an UIT procedure. To detect inconsistent test scores from UIT, a cumulative sum procedure (CUSUM
Lerch, Lindsey; Donald, James C; Olivotto, Ivo A; Lesperance, Mary; van der Westhuizen, Nick; Rusnak, Conrad; Biberdorf, Darren; Ross, Alison; Hayashi, Allen
2007-05-01
This study was performed to determine if surgeons' performance of sentinel lymph node biopsy (SLNB) for breast cancer varied with time and to devise a method to continuously evaluate that performance. We retrospectively examined the SLNB experience of 13 community surgeons performing 765 SLNBs and 579 concomitant axillary dissections. False-negative rates (FNRs) were assessed for individuals and cohorts defined by caseload. Performance with time was assessed using cumulative sum (CUSUM) analysis. Overall, the SLN identification rate was 94.3%, and FNR was 5.3%. Each surgeon demonstrated variation in identification rate and/or FNR with time. CUSUM analysis provided an effective means to demonstrate when surgeon variation breached performance standards. Surgeon performance of SLNB varied with time, independent of case load. CUSUM may prove to be a useful statistical tool to evaluate performance before adopting stand-alone SLNB.
Cumulative sum quality control for calibrated breast density measurements
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Heine, John J.; Cao Ke; Beam, Craig [Cancer Prevention and Control Division, Moffitt Cancer Center, 12902 Magnolia Drive, Tampa, Florida 33612 (United States); Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago, 1603 W. Taylor St., Chicago, Illinois 60612 (United States)
2009-12-15
Purpose: Breast density is a significant breast cancer risk factor. Although various methods are used to estimate breast density, there is no standard measurement for this important factor. The authors are developing a breast density standardization method for use in full field digital mammography (FFDM). The approach calibrates for interpatient acquisition technique differences. The calibration produces a normalized breast density pixel value scale. The method relies on first generating a baseline (BL) calibration dataset, which required extensive phantom imaging. Standardizing prospective mammograms with calibration data generated in the past could introduce unanticipated error in the standardized output if the calibration dataset is no longer valid. Methods: Sample points from the BL calibration dataset were imaged approximately biweekly over an extended timeframe. These serial samples were used to evaluate the BL dataset reproducibility and quantify the serial calibration accuracy. The cumulative sum (Cusum) quality control method was used to evaluate the serial sampling. Results: There is considerable drift in the serial sample points from the BL calibration dataset that is x-ray beam dependent. Systematic deviation from the BL dataset caused significant calibration errors. This system drift was not captured with routine system quality control measures. Cusum analysis indicated that the drift is a sign of system wear and eventual x-ray tube failure. Conclusions: The BL calibration dataset must be monitored and periodically updated, when necessary, to account for sustained system variations to maintain the calibration accuracy.
Model-Free CUSUM Methods for Person Fit
Armstrong, Ronald D.; Shi, Min
2009-01-01
This article demonstrates the use of a new class of model-free cumulative sum (CUSUM) statistics to detect person fit given the responses to a linear test. The fundamental statistic being accumulated is the likelihood ratio of two probabilities. The detection performance of this CUSUM scheme is compared to other model-free person-fit statistics…
Bazot, Marc; Daraï, Emile; Biau, David J; Ballester, Marcos; Dessolle, Lionel
2011-01-01
A specific statistical tool (the cumulative summation test for learning curve or LC-CUSUM) was used to monitor the learning curve of four trainees for the diagnosis of endometriomas by transvaginal ultrasound. A large intertrainee variability in the learning curves was found, justifying a tailored training to learn this diagnosis.
Musdalifah, N.; Handajani, S. S.; Zukhronah, E.
2017-06-01
Competition between the homoneous companies cause the company have to keep production quality. To cover this problem, the company controls the production with statistical quality control using control chart. Shewhart control chart is used to normal distributed data. The production data is often non-normal distribution and occured small process shift. Grand median control chart is a control chart for non-normal distributed data, while cumulative sum (cusum) control chart is a sensitive control chart to detect small process shift. The purpose of this research is to compare grand median and cusum control charts on shuttlecock weight variable in CV Marjoko Kompas dan Domas by generating data as the actual distribution. The generated data is used to simulate multiplier of standard deviation on grand median and cusum control charts. Simulation is done to get average run lenght (ARL) 370. Grand median control chart detects ten points that out of control, while cusum control chart detects a point out of control. It can be concluded that grand median control chart is better than cusum control chart.
A CUSUM to Detect Person Misfit: A Discussion and Some Alternatives for Existing Procedures
Tendeiro, Jorge N.; Meijer, Rob R.
2012-01-01
This article extends the work by Armstrong and Shi on CUmulative SUM (CUSUM) person-fit methodology. The authors present new theoretical considerations concerning the use of CUSUM person-fit statistics based on likelihood ratios for the purpose of detecting cheating and random guessing by individual test takers. According to the Neyman-Pearson…
Biau, D J; Meziane, M; Bhumbra, R S; Dumaine, V; Babinet, A; Anract, P
2011-09-01
The purpose of this study was to define immediate post-operative 'quality' in total hip replacements and to study prospectively the occurrence of failure based on these definitions of quality. The evaluation and assessment of failure were based on ten radiological and clinical criteria. The cumulative summation (CUSUM) test was used to study 200 procedures over a one-year period. Technical criteria defined failure in 17 cases (8.5%), those related to the femoral component in nine (4.5%), the acetabular component in 32 (16%) and those relating to discharge from hospital in five (2.5%). Overall, the procedure was considered to have failed in 57 of the 200 total hip replacements (28.5%). The use of a new design of acetabular component was associated with more failures. For the CUSUM test, the level of adequate performance was set at a rate of failure of 20% and the level of inadequate performance set at a failure rate of 40%; no alarm was raised by the test, indicating that there was no evidence of inadequate performance. The use of a continuous monitoring statistical method is useful to ensure that the quality of total hip replacement is maintained, especially as newer implants are introduced.
CUSUM-Based Person-Fit Statistics for Adaptive Testing.
van Krimpen-Stoop, Edith M. L. A.; Meijer, Rob R.
2001-01-01
Proposed person-fit statistics that are designed for use in a computerized adaptive test (CAT) and derived critical values for these statistics using cumulative sum (CUSUM) procedures so that item-score patterns can be classified as fitting or misfitting. Compared nominal Type I errors with empirical Type I errors through simulation studies. (SLD)
CUSUM Charts with Controlled Conditional Performance Under Estimated Parameters
Saleh, N.A.; Zwetsloot, I.M.; Mahmoud, M.A.; Woodall, W.H.
2016-01-01
We study the effect of the Phase I estimation error on the cumulative sum (CUSUM) chart. Impractically large amounts of Phase I data are needed to sufficiently reduce the variation in the in-control average run lengths (ARL) between practitioners. To reduce the effect of estimation error on the char
CUSUM Chart with Controlled Conditional Performance Under Estimated Parameters
Saleh, N.A.; Zwetsloot, I.M.; Mahmoud, M.A.; Woodall, W.H.
2016-01-01
We study the effect of the Phase I estimation error on the cumulative sum (CUSUM) chart. Impractically large amounts of Phase I data are needed to sufficiently reduce the variation in the in-control average run lengths (ARL) between practitioners. To reduce the effect of estimation error on the char
Cumulative sums for edge determination of a single object in PET and SPECT images
Protonotarios, Nicholas E.; Spyrou, George M.; Kastis, George A.
2016-08-01
The issue of edge determination of a single object in reconstructed nuclear medicine images has been examined thoroughly in the past, nevertheless most of the investigation has focused on the concepts of either numerical sinogram differentiation or segmentation. This work aims to develop an automated method for determining the contour of a single convex object in PET and SPECT reconstructed images, which can be used for computing body edges for attenuation correction, as well as for eliminating streak artifacts outside the specific object. This was accomplished by implementing a modified cumulative sums (CUSUM) scheme in the sinogram. Our method can automatically detect the object's boundary in the reconstructed image. This approach has been tested in simulated as well as real phantoms and it performed efficiently for all convex objects. We were able to detect the contour of a single object in the image space, which in turn enabled us to eliminate streak artifacts outside and thus to obtain body edges necessary for attenuation correction.
Lee, Young-Kyun; Biau, David J; Yoon, Byung-Ho; Kim, Tae-Young; Ha, Yong-Chan; Koo, Kyung-Hoi
2014-03-01
Despite advances in surgical techniques and instrumentation, optimal cup positioning in total hip arthroplasty (THA) is challenging with a limited accuracy. We evaluated whether a learning curve exists for the optimal cup positioning, using the LC-CUSUM test (Learning curve cumulative summation test). We evaluated the first 100 consecutive THA performed by two surgeons, who had a year of fellowship training in the same teaching hospital. A learning curve of cup positioning was plotted in each series using the LC-CUSUM score. There was no significant difference of numbers of outlier between two surgeons (P = 0.079). Both surgeons completed the learning curve of optimal cup positioning before 50 procedures, and maintained competence. A substantial learning period is necessary in the optimal positioning of an acetabular cup.
CUSUM analyses of time-interval data for online radiation monitoring.
Luo, Peng; Devol, Timothy A; Sharp, Julia L
2012-06-01
Three statistical control chart methods were investigated to determine the one with the highest detection probability and the best average run length (ARL). The three control charts include the Shewhart control chart of count data, cumulative sum (CUSUM) analysis of count data (Poisson CUSUM), and CUSUM analysis of time-interval (time difference between two consecutive radiation pulses) data (time-interval CUSUM). The time-interval CUSUM (CUSUMti) control chart was compared with the Poisson CUSUM (CUSUMcnt) and the Shewhart control charts with experimental and simulated data. The experimental data were acquired with a DGF-4C (XIA, Inc.) system in list mode. Simulated data were obtained by using Monte Carlo techniques to obtain a random sampling of a Poisson process. All statistical algorithms were developed using R (R Development Core Team). Detection probabilities and ARLs for the three methods were compared. The time-interval CUSUM control chart resulted in a similar detection probability as that of the Poisson CUSUM control chart but had the shortest ARL at relatively higher radiation levels; e.g., about 40% shorter than the Poisson CUSUM at 10.0 counts per second (cps) (five times above the background count rate). Both CUSUM control charts resulted in a higher detection probability than that of the Shewhart control chart; e.g., 100% greater than the Shewhart control method at 4.0 cps (two times above the background count rate). In addition, when time-interval information was used, the CUSUM control chart coupled with a modified runs rule (mrCUSUMti) showed the ability to further reduce the time needed to respond to changes in radiation levels and keep the false positive rate at a required level.
CUSUM: A tool for early feedback about performance?
Directory of Open Access Journals (Sweden)
McLean Ian P
2006-03-01
Full Text Available Abstract Background Modern day clinical practice demands evidence justifying our choice of treatment methods. Cumulative sum techniques (cusum are amongst the simplest statistical methods known. They provide rapid analysis and identification of trends in a series of data. This study highlights use of these techniques as an early performance indicator of a clinical procedure before its implementation. Methods Twenty consecutive patients who underwent total hip or knee arthroplasty received a simple dressing – blue gauze and Tegaderm. Cusum charting was used to assess the dressing with regards to skin blistering. At an acceptable level of performance the curve would oscillate about the horizontal axis and the overall trend therefore said to be flat. If performance is unacceptable, the cusum slopes upward. Results The cusum plot for the twenty patients did not cross the specified control limits. This showed that our simple dressing met specified standards with regards to wound blistering postoperatively. Conclusion We recommend the use of this simple, yet versatile cusum technique in the early evaluation of a clinical procedure before its implementation.
IMU Fault Detection Based on 2-CUSUM
Directory of Open Access Journals (Sweden)
Élcio Jeronimo de Oliveira
2012-01-01
IMU strapdown platforms using fiber optic gyros (FOG or micro electro mechanical systems (MEMSs. A way to solve this problem makes use of sensor redundancy and parity vector (PV analysis. However, the actual sensor outputs can include some anomalies, as impulsive noise which can be associated with the sensors itself or data acquisition process, committing the elementary threshold criteria as commonly used. Therefore, to overcome this problem, in this work, it is proposed an algorithm based on median filter (MF for prefiltering and chi-square cumulative sum (2-CUSUM only for fault detection (FD applied to an IMU composed by four FOGs.
The application of Cumulative Sum control chart in public health surveillance%CUSUM控制图法在公共卫生监测中的应用
Institute of Scientific and Technical Information of China (English)
刘普林; 胡权
2010-01-01
The Cumulative Sum control chart (CUSUM)techniques have been applied widely in public health surveillance in resent years since it was used in the study from industrial quality control to medical problems. Particularly,studies on early aberration alarm and procedure surveillance have been conducted extensively at abroad but there are few in China. The application of CUSUM techniques in public health surveillance in these international studies is reviewed in this article.%CUSUM控制图法从工业及制造业质量控制领域引入医学领域以来,在公共卫生监测中的应用研究越来越广泛,特别是在异常信息监测预警及过程监测控制等方面国外开展较多,但在我国还未见相关研究报道.此文就国际上CUSUM控制图法在公共卫生监测中的应用研究进展进行了综述.
New quality monitoring tools provided by the Scientific Registry of Transplant Recipients: CUSUM.
Snyder, J J; Salkowski, N; Zaun, D; Leppke, S N; Leighton, T; Israni, A K; Kasiske, B L
2014-03-01
The Scientific Registry of Transplant Recipients (SRTR) has been providing data on transplant program performance through semi-annual release of program-specific reports (PSRs). A consensus conference held in February 2012 recommended that SRTR also supply transplant programs with tools such as the cumulative sum (CUSUM) technique to facilitate quality assessment and performance improvement. SRTR developed the process, methodologies, programming code and web capabilities necessary to bring the CUSUM charts to the community, and began releasing them to all liver, kidney, heart and lung programs in July 2013. Observed-minus-expected CUSUM charts provide a general picture of a program's performance (all-cause graft failure and mortality within the first-year posttransplant) over a 3-year period; one-sided charts can determine when performance appears to be sufficiently worrisome to warrant action by the program. CUSUM charts are intended for internal quality improvement by allowing programs to better track performance in near-real time and day to day, and will not be used to indicate whether a program will be flagged for review. The CUSUM technique is better suited for real-time quality monitoring than the current PSRs in allowing monthly outcomes monitoring and presenting data recorded as recently as 2 months before the release of the CUSUM charts.
Application of a binomial cusum control chart to monitor one drinking water indicator
Directory of Open Access Journals (Sweden)
Elisa Henning
2014-02-01
Full Text Available The aim of this study is to analyze the use of a binomial cumulative sum chart (CUSUM to monitor the presence of total coliforms, biological indicators of quality of water supplies in water treatment processes. The sample series were monthly taken from a water treatment plant and were analyzed from 2007 to 2009. The statistical treatment of the data was performed using GNU R, and routines were created for the approximation of the upper limit of the binomial CUSUM chart. Furthermore, a comparative study was conducted to investigate whether there is a significant difference in sensitivity between the use of CUSUM and the traditional Shewhart chart, the most commonly used chart in process monitoring. The results obtained demonstrate that this study was essential for making the right choice in selecting a chart for the statistical analysis of this process.
Comparing syndromic surveillance detection methods: EARS' versus a CUSUM-based methodology.
Fricker, Ronald D; Hegler, Benjamin L; Dunfee, David A
2008-07-30
This paper compares the performance of three detection methods, entitled C1, C2, and C3, that are implemented in the early aberration reporting system (EARS) and other syndromic surveillance systems versus the CUSUM applied to model-based prediction errors. The cumulative sum (CUSUM) performed significantly better than the EARS' methods across all of the scenarios we evaluated. These scenarios consisted of various combinations of large and small background disease incidence rates, seasonal cycles from large to small (as well as no cycle), daily effects, and various types and levels of random daily variation. This leads us to recommend replacing the C1, C2, and C3 methods in existing syndromic surveillance systems with an appropriately implemented CUSUM method.
Babcock, Gwen D; Talbot, Thomas O; Rogerson, Peter A; Forand, Steven P
2005-10-01
Cumulative sum (CUSUM) charts were originally developed for industrial quality control, but may be adapted for the surveillance of health outcome data, such as birth defects. The reported prevalence of birth defects can vary due to differences in case ascertainment, surveillance practices, or true changes in prevalence. We examined the utility of CUSUM and Shewhart charts for detect-ing changes in prevalence of two different birth defect groups. We chose obstructive renal defects because we expected an increase in reporting due to improved diagnosis. We chose oral clefts for comparison because we expected reporting to be unaffected by changes in diagnostic technologies. Data from the New York State Congenital Malformations Registry from 1992-1999 were analyzed using self-starting binomial CUSUM and Shewhart charts for four regions of New York State. CUSUM charts show that reports of obstructive urinary defects have increased from 1992-1999 in all regions of New York State. Reports of oral clefts increased only on Long Island. The CUSUM method proved useful for identifying changes in birth defect reporting and was able to detect the expected increases in obstructive renal defects. The apparent increase is likely due to improvements in diagnostic imaging techniques. In contrast, we only detected an increase in oral clefts on Long Island, which may be related to under report-ing of cases in the earlier years. CUSUM charts are useful in detecting small, sustained increases in prevalences over time while Shewhart charts are easier to interpret and can detect large sharp increases.
Directory of Open Access Journals (Sweden)
Sung Yong Cho
Full Text Available INTRODUCTION: This study investigated the learning curve of a single-session retrograde intrarenal surgery (RIRS in patients with mid-sized stones. Competence and trainee proficiency for RIRS was assessed using cumulative sum analysis (CUSUM. MATERIALS AND METHODS: The study design and the use of patients' information stored in the hospital database were approved by the Institutional Review Board of our institution. A retrospective review was performed for 100 patients who underwent a single-session RIRS. Patients were included if the main stone had a maximal diameter between 10 and 30 mm. The presence of a residual stone was checked on postoperative day 1 and at one-month follow-up visit. Fragmentation efficacy was calculated "removed stone volume (mm(3 divided by operative time (min". CUSUM analysis was used for monitoring change in fragmentation efficacy, and we tested whether or not acceptable surgical outcomes were achieved. RESULTS: The mean age was 54.7±14.8 years. Serum creatinine level did not change significantly. Estimated GFR and hemoglobin were within normal limits postoperatively. The CUSUM curve tended to be flat until the 25th case and showed a rising pattern but declined again until the 56th case. After that point, the fragmentation efficacy reached a plateau. The acceptable level of fragmentation efficacy was 25 ml/min. Multivariate logistic regression analyses showed that stone-free rate was significantly lower for cases with multiple stones than those with a single stone (OR = 0.147, CI 0.032 - 0.674, P value = 0.005 and for cases with higher number of sites (OR = 0.676, CI 0.517 - 0.882, P value = 0.004. CONCLUSIONS: The statistical analysis of RIRS learning experience revealed that 56 cases were required for reaching a plateau in the learning curve. The number of stones and the number of sites were significant predictors for stone-free status.
Learning Curves of Macintosh Laryngoscope in Nurse Anesthetist Trainees Using Cumulative Sum Method
Directory of Open Access Journals (Sweden)
Panthila Rujirojindakul
2014-01-01
Full Text Available Background. Tracheal intubation is a potentially life-saving procedure. This skill is taught to many anesthetic healthcare professionals, including nurse anesthetists. Our goal was to evaluate the learning ability of nurse anesthetist trainees in their performance of orotracheal intubation with the Macintosh laryngoscope. Methods. Eleven nurse anesthetist trainees were enrolled in the study during the first three months of their training. All trainees attended formal lectures and practice sessions with manikins at least one time on performing successful tracheal intubation under supervision of anesthesiology staff. Learning curves for each nurse anesthetist trainee were constructed with the standard cumulative summation (cusum methods. Results. Tracheal intubation was attempted on 388 patients. Three hundred and six patients (78.9% were successfully intubated on the trainees’ first attempt and 17 patients (4.4% on the second attempt. The mean ± SD number of orotracheal intubations per trainee was 35.5 ± 5.1 (range 30–47. Ten (90.9% of 11 trainees crossed the 20% acceptable failure rate line. A median of 22 procedures was required to achieve an 80% orotracheal intubations success rate. Conclusion. At least 22 procedures were required to reach an 80% success rate for orotracheal intubation using Macintosh laryngoscope in nonexperienced nurse anesthetist trainees.
Lindenburg, I.T.; Wolterbeek, R..; Oepkes, D.; Klumper, F.J.; Vandenbussche, F.P.H.A.; Kamp, I.L. van
2011-01-01
INTRODUCTION: Intravascular intrauterine transfusion (IUT) is an effective and relatively safe method for the treatment of fetal anemia. Although implemented in centers all over the world in the 1980s, the length and strength of the learning curve for this procedure has never been studied. Cumulativ
Directory of Open Access Journals (Sweden)
Wright Graeme
2008-08-01
Full Text Available Abstract Background The automated monitoring of routinely collected disease surveillance data has the potential to ensure that important changes in disease incidence are promptly recognised. However, few studies have established whether the signals produced by automated monitoring methods correspond with events considered by epidemiologists to be of public health importance. This study investigates the correspondence between retrospective epidemiological evaluation of notifications of Ross River virus (RRv disease in Western Australia, and the signals produced by two cumulative sum (cusum-based automated monitoring methods. Methods RRv disease case notification data between 1991 and 2004 were assessed retrospectively by two experienced epidemiologists, and the timing of identified outbreaks was compared with signals generated from two different types of cusum-based automated monitoring algorithms; the three Early Aberration Reporting System (EARS cusum algorithms (C1, C2 and C3, and a negative binomial cusum. Results We found the negative binomial cusum to have a significantly greater area under the receiver operator characteristic curve when compared with the EARS algorithms, suggesting that the negative binomial cusum has a greater level of agreement with epidemiological opinion than the EARS algorithms with respect to the existence of outbreaks of RRv disease, particularly at low false alarm rates. However, the performance of individual EARS and negative binomial cusum algorithms were not significantly different when timeliness was also incorporated into the area under the curve analyses. Conclusion Our retrospective analysis of historical data suggests that, compared with the EARS algorithms, the negative binomial cusum provides greater sensitivity for the detection of outbreaks of RRv disease at low false alarm levels, and decreased timeliness early in the outbreak period. Prospective studies are required to investigate the potential
Cloern, James E.; Jassby, Alan D.; Carstensen, Jacob; Bennett, William A.; Kimmerer, Wim; Mac Nally, Ralph; Schoellhamer, David H.; Winder, Monika
2012-01-01
We comment on a nonstandard statistical treatment of time-series data first published by Breton et al. (2006) in Limnology and Oceanography and, more recently, used by Glibert (2010) in Reviews in Fisheries Science. In both papers, the authors make strong inferences about the underlying causes of population variability based on correlations between cumulative sum (CUSUM) transformations of organism abundances and environmental variables. Breton et al. (2006) reported correlations between CUSUM-transformed values of diatom biomass in Belgian coastal waters and the North Atlantic Oscillation, and between meteorological and hydrological variables. Each correlation of CUSUM-transformed variables was judged to be statistically significant. On the basis of these correlations, Breton et al. (2006) developed "the first evidence of synergy between climate and human-induced river-based nitrate inputs with respect to their effects on the magnitude of spring Phaeocystis colony blooms and their dominance over diatoms."
Asymptotics of trimmed CUSUM statistics
Berkes, István; Schauer, Johannes; 10.3150/10-BEJ318
2012-01-01
There is a wide literature on change point tests, but the case of variables with infinite variances is essentially unexplored. In this paper we address this problem by studying the asymptotic behavior of trimmed CUSUM statistics. We show that in a location model with i.i.d. errors in the domain of attraction of a stable law of parameter $0<\\alpha <2$, the appropriately trimmed CUSUM process converges weakly to a Brownian bridge. Thus, after moderate trimming, the classical method for detecting change points remains valid also for populations with infinite variance. We note that according to the classical theory, the partial sums of trimmed variables are generally not asymptotically normal and using random centering in the test statistics is crucial in the infinite variance case. We also show that the partial sums of truncated and trimmed random variables have different asymptotic behavior. Finally, we discuss resampling procedures which enable one to determine critical values in the case of small and mo...
Institute of Scientific and Technical Information of China (English)
赵宁; 韩东; 宗福季
2005-01-01
In this paper we not only present an estimation of the average run length (ARL) for CUSUM(cumulative sum) control chart but also give a numerical comparison of CUSUM, GLR (Gener-alized Likelihood Ratio), GEWMA (Generalized EWMA) and RFCuscore (Reference-free Cus-core) control charts in detecting the mean shifts of stable processes. The simulation results show that CUSUM has the best performance among the four charts in detecting mean shifts of any size if the index of stability α of stable distribution satisfies 1＜α＜2.%本文给出了累积和控制图(CUSUM)监测稳定过程均值漂移的平均运行长度(ARL)的区间估计,并采用数字模拟的方法对CUSUM,GLR,GEWMA以及RFCuscore四种控制图监测稳定过程均值漂移的效果进行比较,结果显示CUSUM效果最好.
Dynamic probability control limits for risk-adjusted Bernoulli CUSUM charts.
Zhang, Xiang; Woodall, William H
2015-11-10
The risk-adjusted Bernoulli cumulative sum (CUSUM) chart developed by Steiner et al. (2000) is an increasingly popular tool for monitoring clinical and surgical performance. In practice, however, the use of a fixed control limit for the chart leads to a quite variable in-control average run length performance for patient populations with different risk score distributions. To overcome this problem, we determine simulation-based dynamic probability control limits (DPCLs) patient-by-patient for the risk-adjusted Bernoulli CUSUM charts. By maintaining the probability of a false alarm at a constant level conditional on no false alarm for previous observations, our risk-adjusted CUSUM charts with DPCLs have consistent in-control performance at the desired level with approximately geometrically distributed run lengths. Our simulation results demonstrate that our method does not rely on any information or assumptions about the patients' risk distributions. The use of DPCLs for risk-adjusted Bernoulli CUSUM charts allows each chart to be designed for the corresponding particular sequence of patients for a surgeon or hospital.
A risk-adjusted O-E CUSUM with monitoring bands for monitoring medical outcomes.
Sun, Rena Jie; Kalbfleisch, John D
2013-03-01
In order to monitor a medical center's survival outcomes using simple plots, we introduce a risk-adjusted Observed-Expected (O-E) Cumulative SUM (CUSUM) along with monitoring bands as decision criterion.The proposed monitoring bands can be used in place of a more traditional but complicated V-shaped mask or the simultaneous use of two one-sided CUSUMs. The resulting plot is designed to simultaneously monitor for failure time outcomes that are "worse than expected" or "better than expected." The slopes of the O-E CUSUM provide direct estimates of the relative risk (as compared to a standard or expected failure rate) for the data being monitored. Appropriate rejection regions are obtained by controlling the false alarm rate (type I error) over a period of given length. Simulation studies are conducted to illustrate the performance of the proposed method. A case study is carried out for 58 liver transplant centers. The use of CUSUM methods for quality improvement is stressed.
Checking Fine and Gray subdistribution hazards model with cumulative sums of residuals
DEFF Research Database (Denmark)
Li, Jianing; Scheike, Thomas; Zhang, Mei Jie
2015-01-01
Recently, Fine and Gray (J Am Stat Assoc 94:496–509, 1999) proposed a semi-parametric proportional regression model for the subdistribution hazard function which has been used extensively for analyzing competing risks data. However, failure of model adequacy could lead to severe bias in parameter...... estimation, and only a limited contribution has been made to check the model assumptions. In this paper, we present a class of analytical methods and graphical approaches for checking the assumptions of Fine and Gray’s model. The proposed goodness-of-fit test procedures are based on the cumulative sums...
Barratt, Benjamin; Atkinson, Richard; Ross Anderson, H.; Beevers, Sean; Kelly, Frank; Mudway, Ian; Wilkinson, Paul
There is an increasing need for statistical techniques to identify and quantify the effects of traffic management schemes on ambient pollution levels. Cumulative sum (CUSUM) charts have been used extensively in industrial process control to detect deviations in production parameters from pre-determined values. This study investigates the use of the CUSUM procedure to identify change in ambient air pollution levels following the introduction of a traffic management scheme at a specific location in Central London. The CUSUM methods of Lucas first compute the standardised deviations of time series observations from the desired process mean. These are accumulated over time to compute the CUSUM at each time point. Data for the analysis were taken from a kerbside monitoring site on Marylebone Road, a six lane trunk route in Central London. In August 2001 the lane adjacent to the monitoring site was designated as a permanent bus lane. The CUSUM analysis clearly identifies a sustained decrease in carbon monoxide concentrations beginning in 2002. However, seasonality and other factors precluded precise characterisation of the timing of the change. When the analysis was repeated using a reference mean that extrapolated the pre-intervention trend in carbon monoxide concentrations, the CUSUM chart no longer identified a sustained decrease. CUSUM appears to offer a simple and rapid method for identifying sustained changes in pollution levels, but the range of confounding influences on carbon monoxide concentrations, most notably underlying trends, seasonality and independent interventions, complicate its interpretation. Its application in assessing the presence or timing of a stepped change in pollution or similar environmental time series data is recommended in its basic form only where the predicted change is large by comparison with other independent influences. The authors believe that further development of the technique beyond this initial study is worthwhile in order to
LINEAR RELATIONSHIPS TO ASSIST IN PARAMETER SELECTION OF A CUSUM CONTROL CHART
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Michael Anthony Arnold Cox
2012-06-01
Full Text Available The cumulative sum (CUSUM chart is widely employed in quality control. These charts are designed to exhibit acceptable average run lengths (ARL both when the process is in and out of control. For such a chart, for specified ARLs, this paper introduces a technique employing a simple linear approximation for parameter selection. Graphs are produced to provide the coefficients for the fit. The simplicity of this approach should encourage its adoption as an additional tool in the statistical process control kit.
Directory of Open Access Journals (Sweden)
Sibanda Nokuthaba
2007-11-01
Full Text Available Abstract Background The lack of robust systems for monitoring quality in healthcare has been highlighted. Statistical process control (SPC methods, utilizing the increasingly available routinely collected electronic patient records, could be used in creating surveillance systems that could lead to rapid detection of periods of deteriorating standards. We aimed to develop and test a CUmulative SUM (CUSUM based surveillance system that could be used in continuous monitoring of clinical outcomes, using routinely collected data. The low Apgar score (5 minute Apgar score Method A surveillance system based on the Observed minus Expected (O-E as well as the 2-sided Log-Likelihood CUSUM charts was developed. The Log-Likelihood chart was designed to detect a 50% rise (deterioration and halving (improvement in the odds of low Apgar scores. Baseline rates were calculated from data for 2001 to 2004, and were used to monitor deliveries for 2005. Deliveries for nulliparous and multiparous women were monitored separately. All analyses were retrospective. Results The CUSUM system detected periods of increased rates of low Apgar scores for each of the nulliparous and multiparous cohorts. The overall rate for 2005 was eventually found to be 0.67%, which was higher than the baseline reference rate of 0.44% from 2001 to 2004. Conclusion CUSUM methods can be used in continuous monitoring of clinical outcomes using routinely collected data. Used prospectively, they could lead to the prompt detection of periods of suboptimal standards.
暴发规模和持续时间对CUSUM预警模型效能的影响%Effect of magnitude and duration on the performance of Cumulative Sum
Institute of Scientific and Technical Information of China (English)
周鼎伦; 杨维中; 兰亚佳; 李中杰
2012-01-01
To explore the effect of magnitude and duration on the performance of Cumulative Sum (CUSUM),with simulation method used on the subject after the insertion of 11 outbreak events into baseline data with Poisson distribution.Sensitivity fluctuated from 9.1％ to 100.0％ with specificities higher than 98.6％.Sensitivity was significantly correlated with magnitude,and increased along with the increase of magnitude.However,no significant correlation was observed between sensitivity and duration.A magnitude which was at least 2.6 times higher than that of the mean daily baseline could result in the sensitivity of 100.0％.Time-lag would be improved along with the increase of magnitude.Time between onset and detection of an outbreak was no longer than one day when magnitude was more than 1.8 of the mean daily baseline.In summary,the performance of CUSUM was influenced by magnitude,but not by duration.CUSUM had the advantage of good time-lag and high sensitivity when the outbreak magnitude was more than 2.4 time over the baseline data.%采用数据模拟方法,在一段服从Poisson分布的数据序列中插入11个不同暴发规模、不同持续时间的暴发事件,研究暴发规模和持续时间对CUSUM(Cumulative Sum)预警模型效能的影响.结果发现,在现有模拟条件下,灵敏度为9.1％～100.0％,特异度≥98.6％；灵敏度与暴发规模有明显的关系,暴发强度越大,灵敏度越高,而暴发持续时间并不影响灵敏度；灵敏度达到100.0％,暴发规模需≥2.6；暴发规模越大,滞后时间越短；当暴发规模≥1.8时,滞后时间控制在＜1d.可见CUSUM预警模型的预警效能受暴发规模的影响,与暴发持续时间关系不明显.该模型对规模≥2.4的暴发具有较好的探测能力.
Implementation of multivariate cumulative sum control charts in mastitis and lameness monitoring.
Miekley, Bettina; Stamer, Eckhard; Traulsen, Imke; Krieter, Joachim
2013-09-01
This study analyzed the methodology and applicability of multivariate cumulative sum (MCUSUM) charts for early mastitis and lameness detection. Data used were recorded on the Karkendamm dairy research farm, Germany, between August 2008 and December 2010. Data of 328 and 315 cows in their first 200 d in milk were analyzed for mastitis and lameness detection, respectively. Mastitis as well as lameness was specified according to veterinary treatments. Both diseases were defined as disease blocks. Different disease definitions for mastitis and lameness (2 for mastitis and 3 for lameness) varied solely in the sequence length of the blocks. Only the days before the treatment were included in the disease blocks. Milk electrical conductivity, milk yield, and feeding patterns (feed intake, number of trough visits, and feeding time) were used for the recognition of mastitis. Pedometer activity and feeding patterns were used for lameness detection. To exclude biological trends and obtain independent observations, the values of each input variable were either preprocessed by wavelet filters or a multivariate vector autoregressive model. The residuals generated between the observed and filtered or observed and forecast values, respectively, were then transferred to a classic or self-starting MCUSUM chart. The combination of the 2 preprocessing methods with each of the 2 MCUSUM sum charts resulted in 4 combined monitoring systems. For mastitis as well as lameness detection requiring a block sensitivity of at least 70%, all 4 of the combined monitoring systems used revealed similar results within each of the disease definitions. Specificities of 73 to 80% and error rates of 99.6% were achieved for mastitis. The results for lameness showed that the definitions used obtained specificities of up to 81% and error rates of 99.1%. The results indicate that the monitoring systems with these study characteristics have appealing features for mastitis and lameness detection. However, they
Improved sliding window non-parameter cumulation sum algorithm%改进的基于统计学的滑动窗口无参数的累积和算法
Institute of Scientific and Technical Information of China (English)
陈波; 毛剑琳; 乔冠华; 戴宁
2013-01-01
为解决IEEE802.15.4无线传感器网络(WSN)中节点自私行为的检测问题,将最低检测延迟作为决策目标,提出了一种改进的基于统计学的滑动窗口无参数的累积和(SWN-CUSUM)算法.算法通过跟踪来自数据包两次成功传输之间的延迟特征序列,以此来判断无线传感器网络中的节点是否存在自私行为.最后通过NS2仿真工具验证算法的有效性.研究结果表明:改进的算法不仅弱化了阈值对算法性能的影响,还缩小了用于检测自私行为的滑动窗口大小,同时所提算法相对于原SWN-CUSUM算法在计算量及检测延迟上均有改善,证明改进的算法可以有效、快速地检测IEEE802.15.4无线传感器网络中的节点自私行为.%To solve the detection problem of selfish behavior in IEEE802. 15. 4 Wireless Sensor Network ( WSN), an improved Sliding Window Non-parameter Cumulation Sum ( SWN-CUSUM) algorithm based on statistics was proposed to decrease the detection delay. By tracing the delay characteristic sequence between successful transmissions, the algorithm could distinguish if there was a selfish behavior in the WSNs. The NS2 simulation tool was conducted to validate the feasibility of the proposed algorithm. The experimental results show that the improved algorithm not only weakens the impact of the threshold on the performance of the algorithm, but also reduces the size of sliding window used to detect selfish behavior, and the improved algorithm makes improvement in the calculation and the detection delay than the primitive SWN-CUSUM algorithm, so the improved algorithm can detect effectively and rapidly the selfish behavior of nodes in IEEE802. 15.4 WSNs.
Single and Multiple Change Point Detection in Spike Trains: Comparison of Different CUSUM Methods.
Koepcke, Lena; Ashida, Go; Kretzberg, Jutta
2016-01-01
In a natural environment, sensory systems are faced with ever-changing stimuli that can occur, disappear or change their properties at any time. For the animal to react adequately the sensory systems must be able to detect changes in external stimuli based on its neuronal responses. Since the nervous system has no prior knowledge of the stimulus timing, changes in stimulus need to be inferred from the changes in neuronal activity, in particular increase or decrease of the spike rate, its variability, and shifted response latencies. From a mathematical point of view, this problem can be rephrased as detecting changes of statistical properties in a time series. In neuroscience, the CUSUM (cumulative sum) method has been applied to recorded neuronal responses for detecting a single stimulus change. Here, we investigate the applicability of the CUSUM approach for detecting single as well as multiple stimulus changes that induce increases or decreases in neuronal activity. Like the nervous system, our algorithm relies exclusively on previous neuronal population activities, without using knowledge about the timing or number of external stimulus changes. We apply our change point detection methods to experimental data obtained by multi-electrode recordings from turtle retinal ganglion cells, which react to changes in light stimulation with a range of typical neuronal activity patterns. We systematically examine how variations of mathematical assumptions (Poisson, Gaussian, and Gamma distributions) used for the algorithms may affect the detection of an unknown number of stimulus changes in our data and compare these CUSUM methods with the standard Rate Change method. Our results suggest which versions of the CUSUM algorithm could be useful for different types of specific data sets.
CUSUM control charts based on likelihood ratio for preliminary analysis
Institute of Scientific and Technical Information of China (English)
Yi DAI; Zhao-jun WANG; Chang-liang ZOU
2007-01-01
To detect and estimate a shift in either the mean and the deviation or both for the preliminary analysis, the statistical process control (SPC) tool, the control chart based on the likelihood ratio test (LRT), is the most popular method.Sullivan and woodall pointed out the test statistic lrt (n1, n2) is approximately distributed as x2 (2) as the sample size n, n1 and n2 are very large, and the value of n1 = 2, 3,..., n- 2 and that of n2 = n- n1.So it is inevitable that n1 or n2 is not large. In this paper the limit distribution of lrt(n1, n2) for fixed n1 or n2 is figured out, and the exactly analytic formulae for evaluating the expectation and the variance of the limit distribution are also obtained.In addition, the properties of the standardized likelihood ratio statistic slr(n1,n) are discussed in this paper. Although slr(n1, n) contains the most important information, slr(i, n)(i ≠ n1) also contains lots of information. The cumulative sum (CUSUM) control chart can obtain more information in this condition. So we propose two CUSUM control charts based on the likelihood ratio statistics for the preliminary analysis on the individual observations. One focuses on detecting the shifts in location in the historical data and the other is more general in detecting a shift in either the location and the scale or both.Moreover, the simulated results show that the proposed two control charts are, respectively, superior to their competitors not only in the detection of the sustained shifts but also in the detection of some other out-of-control situations considered in this paper.
CUSUM control charts based on likelihood ratio for preliminary analysis
Institute of Scientific and Technical Information of China (English)
2007-01-01
To detect and estimate a shift in either the mean and the deviation or both for the preliminary analysis, the statistical process control (SPC) tool, the control chart based on the likelihood ratio test (LRT), is the most popular method. Sullivan and woodall pointed out the test statistic lrt(n1, n2) is approximately distributed as x2(2) as the sample size n,n1 and n2 are very large, and the value of n1 = 2,3,..., n - 2 and that of n2 = n - n1. So it is inevitable that n1 or n2 is not large. In this paper the limit distribution of lrt(n1, n2) for fixed n1 or n2 is figured out, and the exactly analytic formulae for evaluating the expectation and the variance of the limit distribution are also obtained. In addition, the properties of the standardized likelihood ratio statistic slr(n1, n) are discussed in this paper. Although slr(n1, n) contains the most important information, slr(i, n)(i≠n1) also contains lots of information. The cumulative sum (CUSUM) control chart can obtain more information in this condition. So we propose two CUSUM control charts based on the likelihood ratio statistics for the preliminary analysis on the individual observations. One focuses on detecting the shifts in location in the historical data and the other is more general in detecting a shift in either the location and the scale or both. Moreover, the simulated results show that the proposed two control charts are, respectively, superior to their competitors not only in the detection of the sustained shifts but also in the detection of some other out-of-control situations considered in this paper.
Using Page’s cumulative sum test on MODIS time series to detect land-cover changes
CSIR Research Space (South Africa)
Grobler, TL
2012-01-01
Full Text Available LETTERS, VOL. XXX, NO. Y, MONTH YEAR 1 Using Page’s Cumulative Sum Test on MODIS time series to detect land cover changes T.L. Grobler, Student Member, IEEE, E.R. Ackermann, Student Member, IEEE, A.J. van Zyl, J.C. Olivier, W. Kleynhans and B.P. Salmon....R. Ackermann is with the Computational and Applied Mathematics Department, Rice University, Houston, TX 77005-1827 USA A.J. van Zyl is with the Department of Mathematics and Applied Mathe- matics, University of Pretoria, Pretoria 0002, South Africa. J...
Detecting DDoS attacks in source-end network with CUSUM algorithm%CUSUM算法在DDoS源端检测中的应用
Institute of Scientific and Technical Information of China (English)
康健; 鞠九滨
2006-01-01
在深入分析了DDoS源端检测的特点和难点的基础上,引入统计学中非参数改变点检测方法,应用非参数化递归CUSUM(Cumulative Sum)算法对代表性的源端检测系统D-WARD进行了改进.经实验验证,应用CUSUM算法的检测系统具有更低的误报率和漏报率,能够适应更复杂的网络检测环境.
A Cusum-based multilevel alerting method for physiological monitoring.
Yang, Ping; Dumont, Guy; Ansermino, J Mark
2010-07-01
Alerting systems used by current physiological monitors are designed to detect changes in the levels of vital signs, but they tend to be very sensitive to artifacts. This paper proposes a method to detect changes in the direction of trend and generate multilevel alerts according to the statistical significance of the detection. One-point-ahead signal predictions are calculated by averaging the historical data with the weights decreasing in the past. The two-sided cumulative sums (Cusum) of the prediction errors are tested against multiple thresholds to detect change points with two levels of certainty. The temporal shapes of the detected changes are analyzed using heuristics to determine whether to trigger an alert. The method was tested offline using 20 cases collected during surgery at a local hospital. The detection results were evaluated by two experienced anesthesiologists. The direction of trend was correctly detected in 90.2% of the annotated changes for end-tidal carbon dioxide, 89.4% for expiratory minute volume, 91.8% for peak airway pressure, and 95.4% for noninvasive blood pressure. The certainty levels of the true-positive alerts estimated by the algorithm have a high ratio of agreement with the anesthesiologists' evaluations.
Axelrod, D A; Guidinger, M K; Metzger, R A; Wiesner, R H; Webb, R L; Merion, R M
2006-02-01
Access to timely, risk-adjusted measures of transplant center outcomes is crucial for program quality improvement. The cumulative summation technique (CUSUM) has been proposed as a sensitive tool to detect persistent, clinically relevant changes in transplant center performance over time. Scientific Registry of Transplant Recipients data for adult kidney and liver transplants (1/97 to 12/01) were examined using logistic regression models to predict risk of graft failure (kidney) and death (liver) at 1 year. Risk-adjusted CUSUM charts were constructed for each center and compared with results from the semi-annual method of the Organ Procurement and Transplantation Network (OPTN). Transplant centers (N = 258) performed 59 650 kidney transplants, with a 9.2% 1-year graft failure rate. The CUSUM method identified centers with a period of significantly improving (N = 92) or declining (N = 52) performance. Transplant centers (N = 114) performed 18 277 liver transplants, with a 13.9% 1-year mortality rate. The CUSUM method demonstrated improving performance at 48 centers and declining performance at 24 centers. The CUSUM technique also identified the majority of centers flagged by the current OPTN method (20/22 kidney and 8/11 liver). CUSUM monitoring may be a useful technique for quality improvement, allowing center directors to identify clinically important, risk-adjusted changes in transplant center outcome.
Hoogenveen RT; Heisterkamp SH
1991-01-01
The report starts with an introduction into the Cusum quality control scheme. This scheme is meant to improve the operating characteristic in case of small samples. Therefore the likelihood ratios of some bad parameter value with respect to the good parameter value are being summed up for successi
A risk-adjusted CUSUM in continuous time based on the Cox model.
Biswas, Pinaki; Kalbfleisch, John D
2008-07-30
In clinical practice, it is often important to monitor the outcomes associated with participating facilities. In organ transplantation, for example, it is important to monitor and assess the outcomes of the transplants performed at the participating centers and send a signal if a significant upward trend in the failure rates is detected. In manufacturing and process control contexts, the cumulative summation (CUSUM) technique has been used as a sequential monitoring scheme for some time. More recently, the CUSUM has also been suggested for use in medical contexts. In this article, we outline a risk-adjusted CUSUM procedure based on the Cox model for a failure time outcome. Theoretical approximations to the average run length are obtained for this new proposal and for some discrete time procedures suggested in the literature. The proposed scheme and approximations are evaluated in simulations and illustrated on transplant facility data from the Scientific Registry of Transplant Recipients.
Router Anomaly Traffic Detection Based on Modified-CUSUM Algorithms%基于改进CUSUM算法的路由器异常流量检测
Institute of Scientific and Technical Information of China (English)
孙知信; 唐益慰; 程媛
2005-01-01
针对核心路由器端口的输入、输出流量的变化,用改进的CUSUM(cumulative sum)算法对其统计特性进行实时监控,检测网络流量异常.基于路由器多端口的特点,提出了矩阵式的多统计量CUSUM算法(M-CUSUM),并提出了可调的参数设定体系,以提高准确性.M-CUSUM算法通过对输入、输出端口流量的绝对差与和之比进行统计,实时地监控其均值的偏移情况.通过对该算法在计算机中的模拟实现,验证了该算法对DOS/DDOS攻击具有较高的检测速度和精度,且系统开销小,已成功运行在软件路由器之上.
Directory of Open Access Journals (Sweden)
Abdu. M. A. Atta
2011-12-01
Full Text Available In many statistical process control (SPC applications, the ease of use of control charts leads to ignoring the fact that the process population of the quality characteristic being measured may be highly skewed. However, in many situations, the normality assumption is usually violated. Among the recent heuristic charts for skewed distributions proposed in the literature are those based on the weighted standard deviation (WSD method. Thus, this paper compares the performances of certain WSD charts, such as WSD X , WSD Exponential weighted moving Average (WSDEWMA and WSD Cumulative Sum (WSD-CUSUM charts for skewed distributions. The skewed distributions being considered are weibull, gamma and lognormal. The false alarm and mean shift detection rates were computed so as to evaluate the performances of the WSD charts. The WSD X chart was found to have the lowest false alarm rate in cases of known and unknown parameters. Moreover, when parameters are known and unknown, the WSD-CUSUM provided the highest mean shift detection rates. The chart with the lowest false alarm and the highest mean shift detection rates for most level of skewness and sample size, n is assumed to be have a better performance.
CUSUM方法在企业能源审计中的应用%Application of CUSUM Method in Enterprise Energy Audit
Institute of Scientific and Technical Information of China (English)
白尊亮; 冯驯; 梁辰; 于立军
2009-01-01
在企业能源审计过程中,将统计学中的cumulative sum(CUSUM)方法,用于计算企业的节能技改措施节能量并监测技改措施的实施效果,提出了该方法的具体应用步骤,分析了该方法在计算节能量时较基准单耗对比法更为真实的原因.以某建筑陶瓷企业为实际对象,运用该方法所得的结果与实际情况较为一致,从而验证了该方法在企业能源审计中的可行性,建议在企业能源审计中推广该方法.
On the Mathematics behind the CUSUM Control Charts
DEFF Research Database (Denmark)
Madsen, Henrik
1998-01-01
This paper describes the mathematics behind CUSUM control charts. An introduction to CUSUM charts is found in (Madsen 1998).CUSUM charts are well suited for checking a measuring system in operation for any departure from some target or specified values. In general they can be used for:- detecting...... a drift (or shift in the level) of the measuring system, and- detecting a change of the precision of the measuring system.In both cases the CUSUM procedure contains methods for estimating the shift such that maintenance (e.g. recalibration) can take place.The CUSUM procedure is described in ISO/CD 7871...... from CEN-TC 69. However the presentation in ISO/CD 7871 concentrates on the level, whereas CUSUM charts for detecting changes in the precision are not discussed.This document outlines the theory of CUSUM control charts, and both CUSUM procedures for detecting a drift as well as CUSUM procedures...
Goh, Bak Leong; Ganeshadeva Yudisthra, M; Lim, Teck Onn
2009-01-01
Peritoneal dialysis (PD) catheter insertion success rate is known to vary among different operators, and peritoneoscope PD catheter insertion demands mastery of a steep learning curve. Defining a learning curve using a continuous monitoring tool such as a Cumulative Summation (CUSUM) chart is useful for planning training programs. We aimed to analyze the learning curve of a trainee nephrologist in performing peritoneoscope PD catheter implantation with CUSUM chart. This was a descriptive single-center study using collected data from all PD patients who underwent peritoneoscope PD catheter insertion in our hospital. CUSUM model was used to evaluate the learning curve for peritoneoscope PD catheter insertion. Unacceptable primary failure rate (i.e., catheter malfunction within 1 month of insertion) was defined at >40% and acceptable performance was defined at CUSUM chart showed the learning curve of a trainee in acquiring new skill. As the trainee became more skillful with training, the CUSUM curve flattened. Technical proficiency of the trainee nephrologist in performing peritoneoscope Tenckhoff catheter insertion (CUSUM charting as described to monitor primary catheter dysfunction (i.e., failure of catheter function within 1 month of insertion), primary leak (i.e., within 1 month of catheter insertion), and primary peritonitis (i.e., within 2 weeks of catheter insertion).
Phase onset time estimation at regional distances using the CUSUM algorithm
Der, Zoltan A.; Shumway, Robert H.
1999-06-01
A simple approach for the estimation of onset times of regional arrivals was tested. The method consists of the computation of the cumulative sum (CUSUM) of a test statistic, in this case, the absolute value of the trace amplitude, addition of a linear trend to the result and finding minima of the resulting function by various methods. The minima are located at the times where sudden increases in the trace amplitudes occur, i.e., at the phase onsets. The method requires frequency prefiltering in order to enhance the amplitude changes at the phase onsets. It was found that this algorithm performed comparably to a human analyst in finding onset times for Pn arrivals with varying S/ N ratios. Moreover, when applied to the rest of the seismogram, it was effective in finding the onset times of the rest of the regional arrivals as long as these were clearly visible. In the rest of the cases, where there are many poorly defined arrivals, an analyst would also have difficulties in uniquely defining onset times. The method also shares with the human analyst the tendency to pick the onset times late when an emergent arrival is buried in noise.
Institute of Scientific and Technical Information of China (English)
张云贵; 赵华; 王丽娜
2012-01-01
To deal with the rising serious information security problem of the industrial control system (ICS) , this paper presents an intrusion detection method of the non-parametric cumulative sum (CUSUM) for industrial control network. Using the output-input dependent characteristics of the ICS, a mathematical model of the ICS is established to predict the output of the system. Once the sensors of the control system are under attack, the actual output will change. At every moment, the difference between the predicted output of the industrial control model and the measured signal by the sensors is calculated, and then the time-based statistical sequence is formed. By the non-parametric CUSUM algorithm, the online detection of the intrusion attacks is implemented and alarmed. The simulated detection experiments show that the proposed method has a good real-time and low false alarm rate. By choosing appropriate parameters r and β of the non-parametric CUSUM algorithm, the intrusion detection method can accurately detect the attacks before substantial damage to the control system and it is also helpful to monitor the misoperation.%为解决日趋严重的工业控制系统(industrial control system,ICS)信息安全问题,提出一种针对工业控制网络的非参数累积和( cumulative sum,CUSUM)入侵检测方法.利用ICS输入决定输出的特性,建立ICS的数学模型预测系统的输出,一旦控制系统的传感器遭受攻击,实际输出信号将发生改变.在每个时刻,计算工业控制模型的预测输出与传感器测量信号的差值,形成基于时间的统计序列,采用非参数CUSUM算法,实现在线检测入侵并报警.仿真检测实验证明,该方法具有良好的实时性和低误报率.选择适当的非参数CUSUM算法参数T和β,该入侵检测方法不但能在攻击对控制系统造成实质伤害前检测出攻击,还对监测ICS中的误操作有一定帮助.
Institute of Scientific and Technical Information of China (English)
王小莉; 张奕; 杨鹏; 钱海坤; 张莉; 田丽丽; 黎新宇; 王全意
2011-01-01
Objects To explore the efficiency of Cumulative Sum (CUSUM) and Exponentially Weighted Moving Average (EWMA) for detecting the onset of the epidemic of pandemic H1N1 2008.Methods Influenza like-illness (ILI) surveillance data was analyzed to detect the onset week of the epidemic of pandemic H1N1 2009,using the model of CUSUM and EWMA.The results were compared with the gold standard at different combination of parameter values.Results The 41 st week was considered as onset of the epidemic of pandemic H1N1 2009 according to the gold standard based on the results from influenza virologic surveillance data.Both CUSUM and EWMA triggered the signal before the 42nd week.Differences in performances were observed as parameter values changed.Conclusions The parameter values of CUSUM and EWMA had a correlation to their performances.CUSUM and EWMA could be used for detecting the onset of the epidemic of pandemic H1N1 2008.%目的 探讨累计和( CUSUM)和指数加权移动平均(EWMA)模型探测甲型H1 N1流感流行起始的功效.方法 利用北京市2009年流感样病例监测数据,分别采用CUSUM和EWMA模型对数据进行分析,与流感病原学监测数据进行对比,分析了不同参数组合下2种模型探测甲型H1N1流感流行起始的效果.结果 流感病原学监测显示2009年北京市甲型H1N1流感流行的起始时间为第41周,而CUSUM和EWMA模型均能在第42周之前发出预警信号；参数不同,CUSUM和EWMA模型的预警功效亦不同.结论 CUSUM和EWMA模型参数值与其预警功效有关,CUSUM和EWMA模型可用于探测甲型H1N1流感流行的起始.
Outlier reset CUSUM for the exploration of copy number alteration data.
Lai, Yinglei; Gastwirth, Joseph L
2015-08-01
Copy number alteration (CNA) data have been collected to study disease related chromosomal amplifications and deletions. The CUSUM procedure and related plots have been used to explore CNA data. In practice, it is possible to observe outliers. Then, modifications of the CUSUM procedure may be required. An outlier reset modification of the CUSUM (ORCUSUM) procedure is developed in this paper. The threshold value for detecting outliers or significant CUSUMs can be derived using results for sums of independent truncated normal random variables. Bartel's non-parametric test for autocorrelation is also introduced to the analysis of copy number variation data. Our simulation results indicate that the ORCUSUM procedure can still be used even in the situation where the degree of autocorrelation level is low. Furthermore, the results show the outlier's impact on the traditional CUSUM's performance and illustrate the advantage of the ORCUSUM's outlier reset feature. Additionally, we discuss how the ORCUSUM can be applied to examine CNA data with a simulated data set. To illustrate the procedure, recently collected single nucleotide polymorphism (SNP) based CNA data from The Cancer Genome Atlas (TCGA) Research Network is analyzed. The method is applied to a data set collected in an ovarian cancer study. Three cytogenetic bands (cytobands) are considered to illustrate the method. The cytobands 11q13 and 9p21 have been shown to be related to ovarian cancer. They are presented as positive examples. The cytoband 3q22, which is less likely to be disease related, is presented as a negative example. These results illustrate the usefulness of the ORCUSUM procedure as an exploratory tool for the analysis of SNP based CNA data.
Institute of Scientific and Technical Information of China (English)
魏文; 段美华
2014-01-01
本文利用给汽车加油过程中的一组样本观测数据，分别采用CUSUM（累积和）和EWMA（指数加权移动平均）控制图对其进行对比，分析了不同的参数组合下的两种控制图的监控效果。通过研究发现，当参数不同时，CUSUM和EWMA控制图的效果也不同。相对而言，EWMA控制图受参数影响较小，CUSUM控制图则受参数的影响较大。结果表明：这两种控制图可用于监控加油机给汽车加油的过程，且它们的参数设置和预警效果有关，应根据实际的情况合理设置参数。%This paper detects a dataset in fill cans for cars to explore the efficiency of Cumulative Sum (CUSUM) control chart and Exponentially Weighted Moving Average (EWMA) control chart. The results show that differences in performances are obtained when parameter values changed. EWMA control chart is less affected by the parameter values, on the contrary, CUSUM control chart is easily affected. In addition, the two types of control charts could be used for detecting the process in filling cans and the parameter values of CUSUM and EWMA have a correlation to their performances. Reasonable parameter values should be chosen according to the actual situation.
Improving the performance of CUSUM charts
Riaz, M.; Abbas, N.; Does, R.J.M.M.
2011-01-01
The control chart is an important statistical technique that is used to monitor the quality of a process. Shewhart control charts are used to detect larger disturbances in the process parameters, whereas CUSUM and EWMA charts are meant for smaller and moderate changes. Runs rules schemes are general
Niaki, Seyed Taghi Akhavan; Javad Ershadi, Mohammad
2012-12-01
In this research, the main parameters of the multivariate cumulative sum (CUSUM) control chart (the reference value k, the control limit H, the sample size n and the sampling interval h) are determined by minimising the Lorenzen-Vance cost function [Lorenzen, T.J., and Vance, L.C. (1986), 'The Economic Design of Control Charts: A Unified Approach', Technometrics, 28, 3-10], in which the external costs of employing the chart are added. In addition, the model is statistically constrained to achieve desired in-control and out-of-control average run lengths. The Taguchi loss approach is used to model the problem and a genetic algorithm, for which its main parameters are tuned using the response surface methodology (RSM), is proposed to solve it. At the end, sensitivity analyses on the main parameters of the cost function are presented and their practical conclusions are drawn. The results show that RSM significantly improves the performance of the proposed algorithm and the external costs of applying the chart, which are due to real-world constraints, do not increase the average total loss very much.
Wong, Kai-Pun; Lang, Brian Hung-Hin; Lam, Shi; Au, Kin-Pan; Chan, Diane Toi-yin; Kotewall, Nicholas Clarence
2016-03-01
Transcutaneous laryngeal ultrasonography (TLUSG) is a promising alternative to laryngoscopy in vocal cords (VCs) assessment which might be challenging in the beginning. However, it remains unclear when an assessor can provide proficient TLUSG enough to abandon direct laryngoscopy . Eight surgical residents (SRs) without prior USG experience were recruited to determine the learning curve. After a standardized training program, SRs would perform 80 consecutive peri-operative VCs assessment using TLUSG. Performances of SRs were quantitatively evaluated by a composite performance score (lower score representing better performance) which comprised total examination time (in seconds), VCs visualization, and assessment accuracy. Cumulative sum (CUSUM) chart was then used to evaluate learning curve. Diagnostic accuracy and demographic data between every twentieth TLUSG were compared. 640 TLUSG examinations had been performed by 8 residents. 95.1% of VCs could be assessed by SRs. The CUSUM curve showed a rising pattern (learning phase) until 7th TLUSG and then flattened. The curve declined continuously after 42nd TLUSG (after reaching a plateau). Rates of assessable VCs were comparable in every twentieth cases performed. It took a longer time to complete TLUSG in 1st-20th than 21st-40th examinations. (45 vs. 32s, p = 0.001). Although statistically not significant, proportion of false-negative results was higher in 21st-40th (2.5%) than 1(st)-20th (0.6%), 41(st)-60th (0.7%), and 61(st)-80th (0.7%) TLUSG performed. After a short formal training, surgeons could master skill in TLUSG after seven examination and assess vocal cord function consistently and accurately after 40 TLUSG.
p-Values and Alternative Boundaries for CUSUM Tests
2001-01-01
Firstly rather accurate approximations to the p value functions of the common Standard CUSUM test and the OLS-based CUSUM test for structural change are derived. Secondly alternative boundaries for both tests are suggested and their properties are examined by simulation of expected p values. It turns out that the power of the OLS-based CUSUM test for early and late structural changes can be improved, whereas this weakness of the Standard CUSUM test cannot be repaired by the new boundaries. (a...
Cusum charts for preliminary analysis of individual observations
A.J. Koning (Alex); R.J.M.M. Does (Ronald)
1997-01-01
textabstractA preliminary Cusum chart based on individual observations is developed from the uniformly most powerful test for the detection of linear trends. This Cusum chart is compared with several of its competitors which are based on the likelihood ratio test and on transformations of standardiz
CUSUM analysis of learning curves for the head-mounted microscope in phonomicrosurgery.
Chen, Ting; Vamos, Andrew C; Dailey, Seth H; Jiang, Jack J
2016-10-01
To observe the learning curve of the head-mounted microscope in a phonomicrosurgery simulator using cumulative summation (CUSUM) analysis, which incorporates a magnetic phonomicrosurgery instrument tracking system (MPTS). Retrospective case series. Eight subjects (6 medical students and 2 surgeons inexperienced in phonomicrosurgery) operated on phonomicrosurgical simulation cutting tasks while using the head-mounted microscope for 400 minutes total. Two 20-minute sessions occurred each day for 10 total days, with operation quality (Qs ) and completion time (T) being recorded after each session. Cumulative summation analysis of Qs and T was performed by using subjects' performance data from trials completed using a traditional standing microscope as success criteria. The motion parameters from the head-mounted microscope were significantly better than the standing microscope (P microscope (P microscope, as assessed by CUSUM analysis. Cumulative summation analysis can objectively monitor the learning process associated with a phonomicrosurgical simulator system, ultimately providing a tool to assess learning status. Also, motion parameters determined by our MPTS showed that, although the head-mounted microscope provides better motion control, worse Qs and longer T resulted. This decrease in Qs is likely a result of the relatively unstable visual environment that it provides. Overall, the inexperienced surgeons participating in this study failed to adapt to the head-mounted microscope in our simulated phonomicrosurgery environment. 4 Laryngoscope, 126:2295-2300, 2016. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.
一种适用于超宽带脉冲信号检测的改进CUSUM算法%An Improved CUSUM Algorithm for UWB Pulse Signal Detection
Institute of Scientific and Technical Information of China (English)
宋晓鸥
2013-01-01
将最快检测技术应用于超宽带脉冲信号检测中，具体采用改进的CUSUM（Cumulative Sum）算法来检测超宽带脉冲信号。首先分析了经过多径信道衰减后的超宽带脉冲信号概率分布特性，进一步提出了适用于超宽带脉冲信号检测的改进CUSUM算法。理论分析和仿真证明了所提改进算法性能优越且实现复杂度低。该算法克服了块检测算法的信噪比门限效应，且具有最优的检测延迟性能，相同虚警限制下其检测性能明显优于能量检测算法。%Quickest detection technology or exactly the improved Cumulative Sum(CUSUM)is applied to ultra-wide band(UWB)signal detection . First,the UWB pulse signal distribution after multi-path fading channel is analyzed . Then an improved CUSUM algorithm adaptive to UWB pulse signal detection is proposed . Both theo-retical analysis and simulations prove that the improved algorithm conquers the SNR wall phenomenon,with small detection delay and low realization complexity . Under the same false alarm constraint,the detection per-formance of proposed algorithm is much better than that of energy detection .
Cusum charts for preliminary analysis of individual observations
1997-01-01
textabstractA preliminary Cusum chart based on individual observations is developed from the uniformly most powerful test for the detection of linear trends. This Cusum chart is compared with several of its competitors which are based on the likelihood ratio test and on transformations of standardized recursive residuals on which for instance the Q-chart methodology is based. It turns out that the new proposed Cusum chart is not only superior in the detection of linear trend out-of-control co...
An Introduction to CUSUM Charts for COntrolling Measurement Systems
DEFF Research Database (Denmark)
Madsen, Henrik
1998-01-01
This paper gives an introduction to the CUSUM technique for quality assurance of measuring sytems. A seperate paper (Madsen 1998) gives a more detailed description of the mathematics behind the CUSUM technique. Also a brief description of some of the international standards which could be used...... for quality assurance of a measuring system is provided.The CUSUM technique is weel suited for detection of even rather small (systematical) errors of a measuring system, and the technique gives also an estimate of the time point were the error occurred....
Energy Technology Data Exchange (ETDEWEB)
Jessop, B.M.; Harvie, C.J. [Department of Fisheries and Oceans, Dartmouth, NS (Canada). Bedford Inst. of Oceanography
2003-07-01
American eel elvers are among the diadromous fishes native to the Saint John River in New Brunswick that have been affected by the construction of hydroelectric dams. Before 1980, large numbers of elvers were observed entering the fishway of the Mactaquac Dam in May and June for upstream migration, but their presence abruptly ceased after 1980. A study was conducted to determine why they disappeared at the Mactaquac Dam. A cumulative sum (CUSUM) analysis was performed to determine the variability in magnitude, duration, timing, frequency, and rate of change in the daily and seasonal average level of water discharge associated with the installation of the last two of six turbines in late 1979 and early 1980. It is believed that the rapid, short-term fluctuations in water discharge which is characteristic of peaking hydroelectric dam operations, could seriously affect life cycle transitions of diadromous fishes. Upstream and downstream migration of the elvers may be affected along with their abundance, diversity and productivity. Young fish in particular are at higher risk of mortality during high flows, depending on the species. 40 refs., 3 tabs., 10 figs.
CUSUM绘制在心外科住院医师临床培养中的应用%Application of CUSUM curve in cardiac surgery resident clinical training
Institute of Scientific and Technical Information of China (English)
高峰; 许李力
2015-01-01
目的 探讨累积和控制图(cumulative sum control chart,CUSUM)绘制在心外科住院医师和进修医师临床培养中的应用.方法 将某位工作时间10年以上主治医师的制备乳内动脉操作情况设为对照基准(标准组,28例患者).选取从事心外科专业临床工作不超过5年的住院医师1名(组一)、从事心外科专业临床工作超过5年的进修医师1名(组二),针对两人的制备乳内动脉操作各取40例患者资料,记录术后乳内动脉流量、乳内动脉制备时间及不良事件等数据,利用SPSS 19.0进行统计学分析,并用Matlab R2012b进行多项式曲线拟合描绘CUSUM.结果 在手术技术操作密度得到保障和操作例数达到25例左右时,有此技术操作经验的外科医生的多项式拟合曲线曲率可达到0,成功跨越学习曲线,CUSUM累积和值在66～76.而不能保证操作密度的情况下,无此手术经验的外科医生,即便CUSUM累积和值达到70左右,多项式拟合曲线曲率亦无法达到0,即无法跨越学习曲线.结论 CUSUM绘制为临床医师培养明确了量化指标,使带教教师能了解年轻医师的学习进程,及时更改教学方案,帮助年轻医师尽快跨越学习曲线.%Objective To investigate the application of CUSUM (cumulative sum control chart) curve in cardiac clinical teaching of resident surgeon education.Methods We chose a surgeon of 10years work experience of attending the preparation operation of internal mammary artery as control reference (standard group,28 patients) and a resident engaged in professional clinical cardiac work no more than 5 years as group 1,a professional training physician engaged in cardiac surgery clinical work more than 5 years as group 2 and took 40 patients' data respectively from the two groups' preparation of internal mammary artery operation.And then we recorded the postoperative mammary artery flow,internal mammary artery preparation time and adverse events data and made
Institute of Scientific and Technical Information of China (English)
李诚; 杜坤; 周明; 刘年东; 唐秀秀
2016-01-01
给水管网是城市重要的基础设施之一，负担着输水配水的重要任务，但目前爆管事故频发，严重影响了人们的生产和生活。CUSUM 算法利用观测值与目标值偏差的累积进行绘图，具有能对较小异常变化作出明显反应、以及累积滤波的优点。针对以上两个优点提出一种基于 CUSUM算法的给水管网爆管检测方法，并对使用条件进行了验证，最后利用实例进行了算法验证并对 CU-SUM 图进行了分析。结果表明，CUSUM 算法能很好地检测到管网中的爆管并有效的避免误报。
Robust CUSUM-M test in the presence of long-memory disturbances
2000-01-01
We derive the limiting null distribution of the robust CUSUM-M test and the recursive CUSUM-M test for structural change of the coefficients of a linear regression model with long-memory disturbances. It turns out that the asymptotic null distribution of the CUSUM-M statistic is a fractional Brownian Bridge and the asymptotic null distribution of the recursive CUSUM-M statistic is fractional Brownian motion.
An omnibus CUSUM chart for monitoring time to event data.
Phinikettos, Ioannis; Gandy, Axel
2014-07-01
A non-parametric method is proposed for monitoring time-to-event data. A cumulative sum chart is constructed that is able to detect an unknown out-of-control state. This method exploits the absolute differences between the Kaplan-Meier estimator and the in-control distribution over specific time intervals. The efficiency of the algorithm is studied via a simulation and a real data study. The new method is also tested via the simulation study against existing methods.
Cundy, Thomas P; Rowland, Simon P; Gattas, Nicholas E; White, Alan D; Najmaldin, Azad S
2015-06-01
Fundoplication is a leading application of robotic surgery in children, yet the learning curve for this procedure (RF) remains ill-defined. This study aims to identify various learning curve transition points, using cumulative summation (CUSUM) analysis. A prospective database was examined to identify RF cases undertaken during 2006-2014. Time-based surgical process outcomes were evaluated, as well as clinical outcomes. A total of 57 RF cases were included. Statistically significant transitions beyond the learning phase were observed at cases 42, 34 and 37 for docking, console and total operating room times, respectively. A steep early learning phase for docking time was overcome after 12 cases. There were three Clavien-Dindo grade ≥ 3 complications, with two patients requiring redo fundoplication. We identified numerous well-defined learning curve trends to affirm that experience confers significant temporal improvements. Our findings highlight the value of the CUSUM method for learning curve evaluation. Copyright © 2014 John Wiley & Sons, Ltd.
2004-01-01
Abstract: This paper investigates by means of Monte Carlo techniques the robustness of the CUSUM and CUSUM-of-squares tests (Brown et al., 1975) to serial correlation, endogeneity and lack of structural invariance. Our findings suggest that these tests perform better in the context of a dynamic model of the ADL type, which is not affected by serial correlation or nonpredetermined regressors even if over-specified. In this case, the empirical sizes of both tests are close to the nominal ones, ...
Frequency Jump Detection and Analysis
2008-12-01
CUMULATIVE SUM JUMP DETECTION The Cumulative Sum ( CUSUM ) is a classic change-point analysis technique that uses the cumulative sum of the...sum and y is the average of the data. The CUSUM slope indicates the value of the data with respect to the overall average. A flat cumulative sum...sudden change in the CUSUM slope indicates a jump in the data. The CUSUM plot for a data set having a single jump will have a V or inverted V shape
Pascual, M Angela; Alcazar, Juan Luís; Graupera, Betlem; Rodriguez, Ignacio; Guerriero, Stefano; Mallafre, Anna; de Lorenzo, Cristina; Hereter, Lourdes
2016-12-01
We evaluated learning curve cumulative summation (CUSUM) of 3-dimensional (3D) sonography for diagnosis of congenital uterine anomalies and the deviations of the level of trainees' performance at the control-stage CUSUM. First-year (R1), second-year (R2), and third-year (R3) residents in obstetrics and gynecology received a training program to learn how to analyze 3D sonographic volumes and to classify congenital uterine anomalies. Each trainee worked on 155 3D sonographic volumes from preselected patients. Their results were evaluated by learning curve CUSUM and standard CUSUM. The time for each volume analysis was calculated for the expert examiner and the trainees. Trainees R1, R2, and R3 reached competence at the 85th, 58th, and 40th evaluations, respectively, with success rates of 80%, 81%, and 85%, and kept the process under control with error levels of less than 4.5% until the end of the test. The trainees significantly reduced the average time of the evaluation per volume (P < .001). Learning curve CUSUM provided quantitative indicators of the learning evolution of 3D sonography for diagnosis of congenital uterine anomalies by obstetrics and gynecology residents. The training received by the residents was adequate for diagnosis of congenital uterine anomalies using 3D sonography. © 2016 by the American Institute of Ultrasound in Medicine.
CUSUM chart to monitor autocorrelated counts using Negative Binomial GARMA model.
Albarracin, Orlando Yesid Esparza; Alencar, Airlane Pereira; Lee Ho, Linda
2017-01-01
Cumulative sum control charts have been used for health surveillance due to its efficiency to detect soon small shifts in the monitored series. However, these charts may fail when data are autocorrelated. An alternative procedure is to build a control chart based on the residuals after fitting autoregressive moving average models, but these models usually assume Gaussian distribution for the residuals. In practical health surveillance, count series can be modeled by Poisson or Negative Binomial regression, this last to control overdispersion. To include serial correlations, generalized autoregressive moving average models are proposed. The main contribution of the current article is to measure the impact, in terms of average run length on the performance of cumulative sum charts when the serial correlation is neglected in the regression model. Different statistics based on transformations, the deviance residual, and the likelihood ratio are used to build cumulative sum control charts to monitor counts with time varying means, including trend and seasonal effects. The monitoring of the weekly number of hospital admissions due to respiratory diseases for people aged over 65 years in the city São Paulo-Brazil is considered as an illustration of the current method.
A comparison of weighted CUSUM procedures that account for monotone changes in population size.
Shu, Lianjie; Jiang, Wei; Tsui, Kwok-Leung
2011-03-30
The CUSUM procedure has been popularly used for detecting a shift in the incidence rate of a rare health event. Many CUSUM methods are developed based on a Poisson model with a constant mean number of events. In practice, the expected number of events is likely to vary over time as the population size at risk is not constant but often grows over time. An increase in the baseline incidence rate tends to be masked by the population growth. To efficiently detect an increase in the baseline incidence rate, it is appealing to assign more weight to recent observations and less weight to older observations. This paper compares weighted CUSUM (WCUSUM) and conventional CUSUM procedures in the presence of monotone changes in population size. The simulation results show that the WCUSUM method may be more efficient than the conventional CUSUM methods in detecting increases in the incidence rate, especially for small shifts. An example based on mortality data from New Mexico is used to illustrate the implementation of the WCUSUM method.
Locating Encrypted Data Hidden Among Non-Encrypted Data Using Statistical Tools
2007-03-01
Cumulative Sums ( Cusum ) Test This test calculates the cumulative sums of the bit sequence to determine if it is consistent with a random bit sequence...test indicates a bit sequence with too many or too few ones in the first half where the backward cusum tests for too many or too few ones in the
Directory of Open Access Journals (Sweden)
Jaqueline Betina Broenstrup Correa
2009-06-01
using the CUSUM cumulative addition method. RESULTS: It was calculated that the 105 OTIs were necessary to achieve proficiency. The four trainees crossed the line of acceptable failure rate of 5% before completing 105 OTIs; the first trainee reached proficiency after 42 OTIs, the second and third after 56 OTIs, and the fourth after 97 OTIs, and from then on their performance remained constant. Differences in the success rate between residents and experienced anesthesiologists were not observed. CONCLUSIONS: The CUSUM learning curve is a useful instrument to demonstrate objectively the ability when performing a new task. Laryngoscopy with the Truview EVO2® in a mannequin proved to be an easy procedure for physicians with prior experience in OTI; however, one should be cautious when transposing those results to clinical practice.
2010-09-01
assessing their ability to detect the presence of a known H1N1 outbreak in Monterey County. This research found the cumulative sum ( CUSUM ) detection... CUSUM ), Adaptive Regression 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT Unclassified 18. SECURITY CLASSIFICATION OF THIS PAGE...found the cumulative sum ( CUSUM ) detection method to be the most reliable in signaling the H1N1 outbreak, across all combinations of logic explored
Assessing the Effectiveness of Biosurveillance Via Discrete Event Simulation
2011-03-01
LIST OF ACRONYMS AND ABBREVIATIONS ALGO Algorithm CDC Centers for Disease Control and Prevention CUSUM Cumulative Sum DOC Doctor DES...thereby increasing the total number of people at the hospital with flu-like symptoms. A CUSUM (cumulative sum) statistical algorithm monitors the...average number of people going to the hospital with flu-like symptoms with a false signal rate fixed at once per 30 days. The CUSUM algorithm will signal
Application of CUSUM Model in the Early Warning of Mumps%CUSUM模型在流行性腮腺炎早期预警中的应用研究
Institute of Scientific and Technical Information of China (English)
刘文东; 胡建利; 艾静; 吴莹; 戴启刚; 梁祁; 李媛; 汤奋扬; 朱叶飞
2014-01-01
目的 探讨累积和控制图模型(cumulative sum control chart,CUSUM)在流行性腮腺炎早期预警中的应用价值,为流行性腮腺炎的应急防制提供科学依据,也为其他传染病突发公共卫生事件的预警研究提供参考和借鉴.方法 以江苏省各区县每日发病数为基础,从2012年1月1日起以CUSUM模型进行前瞻性试验,用灵敏度、特异度、及时性等3个指标对预警结果进行评价,并比较CUSUM模型预警与国家传染病自动预警系统(CIDARS)之间的优劣.结果 应用CUSUM模型进行预警分析全年共产生1688条预警信号,比自动预警系统产生的信号数少35.30％.CUSUM模型预警灵敏度为100％、特异度为95.84％,均高于自动预警系统(x2=6.087,P=0.0136;x2=602.48,P＜o.0001);CUSUM模型预警及时性的中位数为3.5天,自动预警系统为6天,两者无统计学差异(Z=0.9173,P=0.3590).结论 江苏省腮腺炎疫情数据CUSUM模型预警分析效果优于自动预警系统,且有进一步提高的空间.
Decompounding random sums: A nonparametric approach
DEFF Research Database (Denmark)
Hansen, Martin Bøgsted; Pitts, Susan M.
review a number of applications and consider the nonlinear inverse problem of inferring the cumulative distribution function of the components in the random sum. We review the existing literature on non-parametric approaches to the problem. The models amenable to the analysis are generalized considerably...
Pong, Wai Yan
2007-01-01
We begin by answering the question, "Which natural numbers are sums of consecutive integers?" We then go on to explore the set of lengths (numbers of summands) in the decompositions of an integer as such sums.
Nonparametric Multivariate CUSUM Chart and EWMA Chart Based on Simplicial Data Depth
Institute of Scientific and Technical Information of China (English)
Yanting; Li Zhaojun Wang
2003-01-01
Simplicial data depth is a useful tool for describing how central a vector is in a multivariate distribution. If the average simplicial depth of a subgroup of observations from a multivariate distribution is too small, it may indicate that a shift in its location or/both scale occurs. In this paper, we propose two new types of nonparametric control charts which are one-sided CUSUM and EWMA control schemes based on simplicial data depth. We also compute the Average Run Length of the CUSUM chart and the EWMA chart by Markov chain method. Recommendations on how to choose the optimal reference value and the smoothing parameter are also given. Comparisons between these two proposed control schemes and the multivariate EWMA are presented.
Kracalik, Ian; Lukhnova, Larissa; Aikimbayev, Alim; Pazilov, Yerlan; Temiralyeva, Gulnara; Blackburn, Jason K
2011-03-01
We analysed livestock anthrax in Kazakhstan from 1960-2006, using a prospective CUSUM to examine the affects of expectation on the detection of spatio-temporal clusters. Three methods for deriving baselines were used for CUSUM; a standard z-score, AVG, a spatially-weighted z-score derived from Local Moran's I, LISA, and a moving-window average, MWA. LISA and AVG elicited alarm signals in the second year that did not return below threshold during the 47-year period, while MWA signaled an alarm at year four and relented at year fifteen. The number of spatial clusters elicited varied: LISA n=16, AVG n=11, and MWA n=3, although there were clusters present around Shymkent, in south-central Kazakhstan, in each method. The results illustrate that the selection of a baseline with an unknown background population has a significant effect on the ability to detect the onset of clusters in space and in time when employing a CUSUM methodology.
The use of cusum analysis in the early detection and management of hospital bed occupancy crises.
Burns, Claire M; Bennett, Cameron J; Myers, Colin T; Ward, Michael
2005-09-19
To assess the value of cusum analysis in hospital bed management. Comparative analysis of medical patient flows, bed occupancy, and emergency department admission rates and access block over 2 years. Internal Medicine Services and Emergency Department in a teaching hospital. Improvements in bed use and changes in the level of available beds. Average length of stay; percentage occupancy of available beds; number of patients waiting more than 8 hours for admission (access block); number of medical patients occupying beds in non-medical wards; and number of elective surgical admissions. Cusum analysis provided a simple means of revealing important trends in patient flows that were not obvious in conventional time-series data. This prompted improvements in bed use that resulted in a decrease of 9500 occupied bed-days over a year. Unfortunately and unexpectedly, after some initial improvement, the levels of access block, medical ward congestion and elective surgical admissions all then deteriorated significantly. This was probably caused by excessive bed closures in response to the initial improvement in bed use. Cusum analysis is a useful technique for the early detection of significant changes in patient flows and bed use, and in determining the appropriate number of beds required for a given rate of patient flow.
A Note on the Sum of Correlated Gamma Random Variables
Paris, Jose F
2011-01-01
The sum of correlated gamma random variables appears in the analysis of many wireless communications systems, e.g. in systems under Nakagami-m fading. In this Letter we obtain exact expressions for the probability density function (PDF) and the cumulative distribution function (CDF) of the sum of arbitrarily correlated gamma variables in terms of certain Lauricella functions.
Noyez, Luc
2009-09-01
Quality control in medicine is generating more and more interest. Industrial concepts of quality control have been refined and transformed to be useful in healthcare monitoring. Whereas medical practitioners first reaction to this new concept of quality control was negative 'we're treating patients, we're not a part of an industrial process', some dramatic cases of inferior medical performance urged the need to adequately monitor healthcare outcomes. To date, several methods have been described, and more and more reports deal with the subject. Most of us, however, are overwhelmed by the new and different tools in use such as Shewhart control charts, cumulative sum charts and funnel plots. This paper will review the methodology of statistical process control and its application in medical practice.
The Soft Cumulative Constraint
Petit, Thierry
2009-01-01
This research report presents an extension of Cumulative of Choco constraint solver, which is useful to encode over-constrained cumulative problems. This new global constraint uses sweep and task interval violation-based algorithms.
Hinchliffe, Ian; Hinchliffe, Ian; Kwiatkowski, Axel
1996-01-01
This review article discusses the experimental and theoretical status of various Parton Model sum rules. The basis of the sum rules in perturbative QCD is discussed. Their use in extracting the value of the strong coupling constant is evaluated and the failure of the naive version of some of these rules is assessed.
Dynamic mass balancing for wastewater treatment data quality control using CUSUM charts.
Spindler, A; Vanrolleghem, P A
2012-01-01
Mass balancing is a widely used tool for data quality control in wastewater treatment. It can effectively detect systematic errors in data. To overcome the limitations of the mean balancing error as a measure of data quality, a well established method for statistical process control (the CUSUM chart) is adopted for application on the error vector of balancing data. Two examples show how time periods with stable low mass balancing errors can be detected by the method. The detectability of such time periods depends on the variability of the balancing error which is an important measure for the precision of the data.
The CUSUM test for detecting structural changes in strong mixing processes
Azizzadeh, Fatemeh
2012-01-01
Strong mixing property holds for a broad class of linear and nonlinear time series models such as ARMA and GARCH models. In this article we study correlation structure of strong mixing sequences, and some asymptotic properties are presented. We also present a new method for detecting change point in correlation structure of strong mixing sequences, and present a nonparametric CUSUM test statistic for this. Asymptotic consistency of this test statistics is shown. This method is applied to simulated data of some linear and nonlinear models and power of the test is evaluated. For linear models, it is shown that this method have a better performance in compare to Berkes et al.(2009).
DEFF Research Database (Denmark)
Brodal, Gerth Stølting; Jørgensen, Allan Grønlund
2008-01-01
In an array of n numbers each of the \\binomn2+nUnknown control sequence '\\binom' contiguous subarrays define a sum. In this paper we focus on algorithms for selecting and reporting maximal sums from an array of numbers. First, we consider the problem of reporting k subarrays inducing the k larges...... an algorithm with this running time and by proving a matching lower bound. Finally, we combine the ideas and obtain an O(n· max {1,log(k/n)}) time algorithm that selects a subarray storing the k’th largest sum among all subarrays of length at least l and at most u....
U.S. Geological Survey, Department of the Interior — The GIS layer "Census_sum_15" provides a standardized tool for examining spatial patterns in abundance and demographic trends of the southern sea otter (Enhydra...
Longitudinal Dynamic Network Analysis. Using the Over Time Viewer Feature in ORA
2009-03-09
capture below. There are three different control chart procedures that can be applied to the signal. We are applying the Cumulative Sum or CUSUM in...control”. For the CUSUM , the analyst can select a standardized magnitude of change to optimize the procedure for. A novice user should just use the...horizontal line is the decision interval of the change detection procedure. When a plot of the CUSUM crosses the decision interval, the analyst may
Change-Point Methods for Overdispersed Count Data
2007-03-01
54 4.5 CUSUM Control Chart for Detecting a Change in Overdispersion Parameter 55 4.6 Performance of the MLE for Step...observation while ignoring the previous sequence of observations. Cumulative sum ( CUSUM ) control charts are effective alternatives for detecting small...changes, using information from the current and previous sequence of observations. Therefore, CUSUMs are good choices to implement during the phase
Statistical Process Control Charts for Public Health Monitoring
2014-12-01
Poisson counts) [21-23]. Cumulative sum ( CUSUM ) and exponentially weighted moving average (EWMA) control charts are often used with Phase II data. These...charts have been shown to more quickly detect small changes than traditional Shewhart charts. There have been several applications of CUSUM charts in...distribution, a CUSUM or EWMA chart would be required. Risk adjustment for health data has been applied when monitoring variables that can be
Dynamic Network Change Detection
2008-12-01
detection methods is presented; the cumulative sum ( CUSUM ), the exponentially weighted moving average (EWMA), and a scan statistic (SS). Statistical...minimizing the risk of false alarms. Three common SPC methods that we consider here are the CUSUM (Page, 1961), EWMA (Roberts, 1959), and the SS...successive dynamic network measures are then used to calculate the statistics for the CUSUM , the EWMA, and the SS. These are then compared to decision
2010-05-01
the CUSUM (Page) test yields the quickest detection of a change of distribution for the case of i.i.d. observations [3]. In fact, in a (highly...11. Autocorrelation of the CUSUM increments, sn, under H1 (target present). Issues in Target Tracking RTO-EN-SET-157(2010...restrictive condition that the increments of the cumulative sum, sn, be i.i.d. [3], [22]. Fig. 11 plots the autocorrelation of the CUSUM increments as a
Active fault diagnosis based on stochastic tests
DEFF Research Database (Denmark)
Poulsen, Niels Kjølstad; Niemann, Hans Henrik
2008-01-01
or an error output from the system. The classical cumulative sum (CUSUM) test will be modified with respect to the AFD approach applied. The CUSUM method will be altered such that it will be able to detect a change in the signature from the auxiliary input signal in an (error) output signal. It will be shown...... how it is possible to apply both the gain and the phase change of the output signal in CUSUM tests. The method is demonstrated using an example....
Use of combined Shewhart-CUSUM control charts for ground water monitoring applications
Energy Technology Data Exchange (ETDEWEB)
Gibbons, R.D.
1999-10-01
Statistical properties of combined Shewhart-CUSUM control charts are examined in terms of the site-wide false positive rate, false negative rate, and average run length (i.e., the average number of sampling events that it takes to detect a significant exceedance). The effects of multiple comparisons (i.e., multiple monitoring wells and constituents), verification resampling, background sample size, and background updating are incorporated into the analysis. The effects of (1) verification resampling plans including no resampling, pass one resample, pass one of two resamples, and pass two of two resamples; (2) background sample sizes (n = 8, 12, 16, 20, and 24); and (3) multiple comparisons (k = 1 to 500 future comparisons) were examined. In addition, various alternative control limit factors (h = SCL = 4.5, 5.0, 5.5, and 6.0) were considered, where the control limit is {bar x} + hs. Results of simulations revealed that it is possible to balance site-wide false positive and false negative rates at low levels using combined Shewhart-CUSUM control charts. The results revealed that it is important to select the appropriate multiplier, verification resampling plan, number of background samples, and number of intervening samples prior to updating background.
Glas, C. A. W.
In a previous study (1998), how to evaluate whether adaptive testing data used for online calibration sufficiently fit the item response model used by C. Glas was studied. Three approaches were suggested, based on a Lagrange multiplier (LM) statistic, a Wald statistic, and a cumulative sum (CUMSUM) statistic respectively. For all these methods,…
Stochastic Change Detection based on an Active Fault Diagnosis Approach
DEFF Research Database (Denmark)
Poulsen, Niels Kjølstad; Niemann, Hans Henrik
2007-01-01
output from the system. The classical CUSUM (cumulative sum) method will be modified such that it will be able to detect change in the signature from the auxiliary input signal in the (error) output signal. It will be shown how it is possible to apply both the gain as well as the phase change...... of the output vector in the CUSUM test....
Meijer, Rob R.; van Krimpen-Stoop, Edith M. L. A.
In this study a cumulative-sum (CUSUM) procedure from the theory of Statistical Process Control was modified and applied in the context of person-fit analysis in a computerized adaptive testing (CAT) environment. Six person-fit statistics were proposed using the CUSUM procedure, and three of them could be used to investigate the CAT in online test…
Memory-type control charts for monitoring the process dispersion
Abbas, N.; Riaz, M.; Does, R.J.M.M.
2014-01-01
Control charts have been broadly used for monitoring the process mean and dispersion. Cumulative sum (CUSUM) and exponentially weighted moving average (EWMA) control charts are memory control charts as they utilize the past information in setting up the control structure. This makes CUSUM and EWMA-t
A Comparative Study of Memory-Type Control Charts under Normal and Contaminated Normal Environments
Nazir, H.Z.; Abbas, N.; Riaz, M.; Does, R.J.M.M.
2016-01-01
Cumulative sum (CUSUM) and exponentially weighted moving average (EWMA) control charts are commonly used to detect small changes in the parameters of production processes. Recently, a new control structure was introduced, named as mixed EWMA–CUSUM control chart, which combined both charts. The
Memory-type control charts for monitoring the process dispersion
Abbas, N.; Riaz, M.; Does, R.J.M.M.
2014-01-01
Control charts have been broadly used for monitoring the process mean and dispersion. Cumulative sum (CUSUM) and exponentially weighted moving average (EWMA) control charts are memory control charts as they utilize the past information in setting up the control structure. This makes CUSUM and EWMA-t
A Comparative Study of Memory-Type Control Charts under Normal and Contaminated Normal Environments
Nazir, H.Z.; Abbas, N.; Riaz, M.; Does, R.J.M.M.
2016-01-01
Cumulative sum (CUSUM) and exponentially weighted moving average (EWMA) control charts are commonly used to detect small changes in the parameters of production processes. Recently, a new control structure was introduced, named as mixed EWMA–CUSUM control chart, which combined both charts. The curre
Computationally efficient algorithm for fast transients detection
Soudlenkov, Gene
2011-01-01
Computationally inexpensive algorithm for detecting of dispersed transients has been developed using Cumulative Sums (CUSUM) scheme for detecting abrupt changes in statistical characteristics of the signal. The efficiency of the algorithm is demonstrated on pulsar PSR J0835-4510.
CSIR Research Space (South Africa)
Mkuzangwe, NNP
2015-08-01
Full Text Available This work implements two anomaly detection algorithms for detecting Transmission Control Protocol Synchronized (TCP SYN) flooding attack. The two algorithms are an adaptive threshold algorithm and a cumulative sum (CUSUM) based algorithm...
High-resolution harmonic retrieval using the full fourth-order cumulant
Vossen, S.H.J.A.; Naus, H.W.L.; Zwamborn, A.P.M.
2010-01-01
The harmonic retrieval (HR) problem concerns the estimation of the frequencies in a sum of real or complex harmonics. Both correlation and cumulant-based approaches are used for this purpose. Cumulant-based HR algorithms use a single 1-D slice of the fourth-order cumulant that is estimated directly
Multiparty Symmetric Sum Types
DEFF Research Database (Denmark)
Nielsen, Lasse; Yoshida, Nobuko; Honda, Kohei
2010-01-01
This paper introduces a new theory of multiparty session types based on symmetric sum types, by which we can type non-deterministic orchestration choice behaviours. While the original branching type in session types can represent a choice made by a single participant and accepted by others...... determining how the session proceeds, the symmetric sum type represents a choice made by agreement among all the participants of a session. Such behaviour can be found in many practical systems, including collaborative workflow in healthcare systems for clinical practice guidelines (CPGs). Processes...... with the symmetric sums can be embedded into the original branching types using conductor processes. We show that this type-driven embedding preserves typability, satisfies semantic soundness and completeness, and meets the encodability criteria adapted to the typed setting. The theory leads to an efficient...
A FEW MORE PROPERTIES OF SUM AND INTEGRAL SUM GRAPHS
Directory of Open Access Journals (Sweden)
V Vilfred
2014-10-01
Full Text Available The concepts of sum graph and integral sum graph were introduced by Harary [7], [8]. A sum graph is a graph whose vertices can be labeled with distinct positive integers so that the sum of the labels on each pair of adjacent vertices is the label of some other vertex. Integral sum graphs have the same definition except that the labels may be any integers. Harary [7], [8], gave examples of all orders of sum graphs and integral sum graphs , nÎN. The family of integral sum graph was extended by Vilfred (see [14], and in this paper, we obtain a few properties of sum and integral sum graphs and two new families of integral sum graphs.
DEFF Research Database (Denmark)
T. Frandsen, Mads; Masina, Isabella; Sannino, Francesco
2011-01-01
We introduce new sum rules allowing to determine universal properties of the unknown component of the cosmic rays and show how it can be used to predict the positron fraction at energies not yet explored by current experiments and to constrain specific models.......We introduce new sum rules allowing to determine universal properties of the unknown component of the cosmic rays and show how it can be used to predict the positron fraction at energies not yet explored by current experiments and to constrain specific models....
Beck, Matthias
2010-01-01
Let $p_1,p_2,\\dots,p_n, a_1,a_2,\\dots,a_n \\in \\N$, $x_1,x_2,\\dots,x_n \\in \\R$, and denote the $k$th periodized Bernoulli polynomial by $\\B_k(x)$. We study expressions of the form \\[ \\sum_{h \\bmod{a_k}} \\ \\prod_{\\substack{i=1\\\\ i\
Adler, Stephen L
2009-01-01
The Adler sum rule states that the integral over energy of a difference of neutrino-nucleon and antineutrino-nucleon structure functions is a constant, independent of the four-momentum transfer squared. This constancy is a consequence of the local commutation relations of the time components of the hadronic weak current, which follow from the underlying quark structure of the standard model.
Languasco, Alessandro
2011-01-01
Assuming that the Generalized Riemann Hypothesis (GRH) holds, we prove an explicit formula for the number of representations of an integer as a sum of $k\\geq 5$ primes. Our error terms in such a formula improve by some logarithmic factors an analogous result by Friedlander-Goldston.
A CUSUM framework for detection of space-time disease clusters using scan statistics.
Sonesson, Christian
2007-11-20
Several methods for timely detection of emerging clusters of diseases have recently been proposed. We focus our attention on one of the most popular types of method; a scan statistic. Different ways of constructing space-time scan statistics based on surveillance theory are presented. We bridge the ideas from space-time disease surveillance, public health surveillance and industrial quality control and show that previously suggested space-time scan statistics methods can be fitted into a general CUSUM framework. Crucial differences between the methods studied are due to different assumptions about the spatial process. An example is the specification of the spatial regions of interest for a possible cluster, another is the increased rate to be detected within a cluster. We evaluate the detection ability of the methods considering the possibility of a cluster emerging at any time during the surveillance period. The methods are applied to the detection of an increased incidence of Tularemia in Sweden.
Assessing the effect of estimation error on risk-adjusted CUSUM chart performance.
2015-12-01
Mark A. Jones, Stefan H. Steiner. Assessing the effect of estimation error on risk-adjusted CUSUM chart performance. Int J Qual Health Care (2012) 24(2): 176–181 doi: 10.1093/intqhc/mzr082. The authors would like to correct an error identified in the above paper. Table 5 included incorrect information. The correct table has been reprinted below. Furthermore, in the discussion on p. 180 of this paper, one of the incorrect numbers in Table 5 was quoted. This section is reproduced below with the correct numbers. In the case of homogeneous patients where adverse event risk was assumed to be constant at 6.6% the estimated level of estimation error: SD (ARL0) = 85.9 was less than the equivalent risk-adjusted scenario where SD (ARL0) = 89.2 but only by around 4%.
Bounds for Certain Character Sums
Institute of Scientific and Technical Information of China (English)
杨锦; 郑志勇
2003-01-01
This paper shows a connection between exponential sums and character sums. In particular, we introduce a character sum that is an analog of the classical Kloosterman sums and establish the analogous Weil-Estermann's upper bound for it. The paper also analyzes a generalized Hardy-Littlewood example for character sums, which shows that the upper bounds given here are the best possible. The analysis makes use of local bounds for the exponential sums and character sums. The basic theorems have been previously established.
2013-01-01
O presente artigo tem como objetivo analisar e controlar estatisticamente um processo industrial, em que o gráfico do tipo Shewhart é o atualmente utilizado. A partir de uma aplicação realizada por meio da pesquisa axiomática quantitativa, são analisadas outras opções como o emprego de um gráfico CUSUM e um gráfico combinado Shewhart-CUSUM. Paralelamente à aplicação dos gráficos de controle, foram desenvolvidos scripts em ambiente R para calcular os limites de controle do gráfico CUSUM, por m...
A Few Finite Trigonometric Sums
Directory of Open Access Journals (Sweden)
Chandan Datta
2017-02-01
Full Text Available Finite trigonometric sums occur in various branches of physics, mathematics, and their applications. These sums may contain various powers of one or more trigonometric functions. Sums with one trigonometric function are known; however, sums with products of trigonometric functions can become complicated, and may not have a simple expression in a number of cases. Some of these sums have interesting properties, and can have amazingly simple values. However, only some of them are available in the literature. We obtain a number of such sums using the method of residues.
Nizard, Remy S; Porcher, Raphael; Ravaud, Philippe; Vangaver, Edouard; Hannouche, Didier; Bizot, Pascal; Sedel, Laurent
2004-08-01
Most of the early failures of total knee replacements are related to technical flaws. Conventional ancillary devices achieve good alignment in the frontal plane in only an average of 75% of total knee replacements. Computer-assisted surgery may improve the technical quality of implantation surgery. The aim of our study was to evaluate the use of computer-assisted surgery using a quality control process. Seventy-eight total knee arthroplasties were done with a CT-based computer-assisted surgery system. The outcomes studied were alignment of the lower limb, implant positioning, and operative time. The target for alignment was 180 degrees +/- 3 degrees. Cusum analysis showed that the three outcomes were controlled during the study. The cusum test identified any existing outliers. Because few data were available at the beginning of this study regarding computer-assisted surgery for total knee replacement, a randomized study was not relevant. However, a control of the procedure was mandatory. The cusum technique allowed continuous evaluation of the performance of the new procedure, and is a useful tool in assessing new technology. The results of this study showed that it is possible to do a randomized study to determine if computer-assisted surgery can improve the technical result of total knee replacement.
Directory of Open Access Journals (Sweden)
Olga Maria Formigoni Carvalho Walter
2013-06-01
Full Text Available O presente artigo tem como objetivo analisar e controlar estatisticamente um processo industrial, em que o gráfico do tipo Shewhart é o atualmente utilizado. A partir de uma aplicação realizada por meio da pesquisa axiomática quantitativa, são analisadas outras opções como o emprego de um gráfico CUSUM e um gráfico combinado Shewhart-CUSUM. Paralelamente à aplicação dos gráficos de controle, foram desenvolvidos scripts em ambiente R para calcular os limites de controle do gráfico CUSUM, por meio da aproximação de Siegmund (1985 e da construção do gráfico combinado Shewhart-CUSUM. Os resultados demonstram que a aplicação, tanto do gráfico CUSUM quanto do gráfico combinado Shewhart-CUSUM, possibilita detectar interferências no processo, as quais não foram identificadas pelo gráfico do tipo Shewhart. Assim, considera-se o gráfico de controle CUSUM, isolado ou combinado com o gráfico do tipo Shewhart, uma ferramenta preventiva mais sensível para avaliar interferências na qualidade do processo. Este artigo será útil tanto para pesquisadores quanto para profissionais da área de Engenharia de Produção e gestão de operações interessados em melhor compreender os parâmetros que compõem o projeto de um gráfico de controle CUSUM, bem como introduzi-lo em processos nos quais atualmente se utiliza somente o gráfico de controle de Shewhart.The objective of this study is to statistically analyze and control an industrial process in which the Shewhart style control chart is used. Through an axiomatic quantitative research, several options of application are evaluated, such as the use of the CUSUM control chart individually or a combined Shewhart-CUSUM chart probabilistically combined. At the same time, R language scripts were developed to calculate the control limits for the CUSUM control chart using Siegmund's (1985 approximation and the construction of the combined CUSUM-Shewhart chart. The results show that the
Cumulative fatigue damage models
Mcgaw, Michael A.
1988-01-01
The problem of calculating expected component life under fatigue loading conditions is complicated by the fact that component loading histories contain, in many cases, cyclic loads of widely varying amplitudes. In such a case a cumulative damage model is required, in addition to a fatigue damage criterion, or life relationship, in order to compute the expected fatigue life. The traditional cumulative damage model used in design is the linear damage rule. This model, while being simple to use, can yield grossly unconservative results under certain loading conditions. Research at the NASA Lewis Research Center has led to the development of a nonlinear cumulative damage model, named the double damage curve approach (DDCA), that has greatly improved predictive capability. This model, which considers the life (or loading) level dependence of damage evolution, was applied successfully to two polycrystalline materials, 316 stainless steel and Haynes 188. The cumulative fatigue behavior of the PWA 1480 single-crystal material is currently being measured to determine the applicability of the DDCA for this material.
Cundy, Thomas P; Gattas, Nicholas E; White, Alan D; Najmaldin, Azad S
2015-08-01
The cumulative summation (CUSUM) method for learning curve analysis remains under-utilized in the surgical literature in general, and is described in only a small number of publications within the field of pediatric surgery. This study introduces the CUSUM analysis technique and applies it to evaluate the learning curve for pediatric robot-assisted laparoscopic pyeloplasty (RP). Clinical data were prospectively recorded for consecutive pediatric RP cases performed by a single-surgeon. CUSUM charts and tests were generated for set-up time, docking time, console time, operating time, total operating room time, and postoperative complications. Conversions and avoidable operating room delay were separately evaluated with respect to case experience. Comparisons between case experience and time-based outcomes were assessed using the Student's t-test and ANOVA for bi-phasic and multi-phasic learning curves respectively. Comparison between case experience and complication frequency was assessed using the Kruskal-Wallis test. A total of 90 RP cases were evaluated. The learning curve transitioned beyond the learning phase at cases 10, 15, 42, 57, and 58 for set-up time, docking time, console time, operating time, and total operating room time respectively. All comparisons of mean operating times between the learning phase and subsequent phases were statistically significant (P=learning curve evaluation and outcome quality monitoring. In applying this statistical technique to the largest reported single surgeon series of pediatric RP, we demonstrate numerous distinctly shaped learning curves and well-defined learning phase transition points. Copyright © 2015 Elsevier Inc. All rights reserved.
Kumar, Alok
2010-01-01
We cannot use directly the results of zero-temperature at finite temperature, for at finite temperature the average is to be carried over all highly degenerate excited states unlike zero-temperature average is only on unique ground state. One of the formal way to take into account the finite temperature into quantum field theory is due to Matsubara, to replace temporal component of eigenvalues $k_{4}$ by $\\omega_{n}=\\frac{2\\pi n}{\\beta}$ $(\\frac{2\\pi (n+{1/2})}{\\beta})$ with summation over all integer values of $n$. The summation is done with the infinite series expansion of $\\coth (\\pi y)$. With the chemical potential $\\mu$, $\\omega_{n}$ will be replaced by $\\omega_{n} - \\mu$ in the eigenvalues and the summation over $n$ cannot be done easily. Various methods exist to evaluate it. We use the infinite series expansion of $\\coth (\\pi y)$ to work operationally for such Matsubara frequency sums.
Huesch, Marco D; Madan, Alok; Borckardt, Jeffrey J
2008-01-01
It is well-known that standard statistical process control tools (eg, Shewhart charts) are not robust to certain features of human-generated data typically seen in health care management. For example, the presence of positive serial correlation (the tendency for successive outcomes to cluster as opposed to being truly random) leads to increased "false alarms." Previous work has introduced potential work-arounds in the case of continuous data (eg, data that can take on many values). In this article we describe a different but related problem in the case of binary data (eg, "survived" vs "deceased"). We demonstrate the value of using the Cumulative Sum chart, which is shown to be relatively robust to serial correlation, and much more efficient and effective than existing control charts.
Sums of multiplicative characters analogue of Kloosterman sums
Xi, Ping
2010-01-01
Let $q$ be a positive integer, $\\chi$ a nontrivial character mod $q$. In this paper the authors prove some estimates for the character sum which is analogue of incomplete Kloostermann sums\\[\\sum_{\\substack{a\\in\\mathcal{I}\\\\ \\gcd(a,q)=1}}\\chi(ma+n\\overline{a}),\\] where $\\overline{a}$ is the multiplicative inverse of $a\\bmod q$, and $\\mathcal{I}$ is a subinterval of $[x+1,x+q]$ for certain integer $x.$
Fluctuations in classical sum rules.
Elton, John R; Lakshminarayan, Arul; Tomsovic, Steven
2010-10-01
Classical sum rules arise in a wide variety of physical contexts. Asymptotic expressions have been derived for many of these sum rules in the limit of long orbital period (or large action). Although sum-rule convergence may well be exponentially rapid for chaotic systems in a global phase-space sense with time, individual contributions to the sums may fluctuate with a width which diverges in time. Our interest is in the global convergence of sum rules as well as their local fluctuations. It turns out that a simple version of a lazy baker map gives an ideal system in which classical sum rules, their corrections, and their fluctuations can be worked out analytically. This is worked out in detail for the Hannay-Ozorio sum rule. In this particular case the rate of convergence of the sum rule is found to be governed by the Pollicott-Ruelle resonances, and both local and global boundaries for which the sum rule may converge are given. In addition, the width of the fluctuations is considered and worked out analytically, and it is shown to have an interesting dependence on the location of the region over which the sum rule is applied. It is also found that as the region of application is decreased in size the fluctuations grow. This suggests a way of controlling the length scale of the fluctuations by considering a time dependent phase-space volume, which for the lazy baker map decreases exponentially rapidly with time.
Cumulative Timers for Microprocessors
Battle, John O.
2007-01-01
It has been proposed to equip future microprocessors with electronic cumulative timers, for essentially the same reasons for which land vehicles are equipped with odometers (total-distance-traveled meters) and aircraft are equipped with Hobbs meters (total-engine-operating time meters). Heretofore, there has been no way to determine the amount of use to which a microprocessor (or a product containing a microprocessor) has been subjected. The proposed timers would count all microprocessor clock cycles and could only be read by means of microprocessor instructions but, like odometers and Hobbs meters, could never be reset to zero without physically damaging the chip.
Cumulative Vehicle Routing Problems
Kara, &#;mdat; Kara, Bahar Yeti&#;; Yeti&#;, M. Kadri
2008-01-01
This paper proposes a new objective function and corresponding formulations for the vehicle routing problem. The new cost function defined as the product of the distance of the arc and the flow on that arc. We call a vehicle routing problem with this new objective function as the Cumulative Vehicle Routing Problem (CumVRP). Integer programming formulations with O(n2) binary variables and O(n2) constraints are developed for both collection and delivery cases. We show that the CumVRP is a gener...
Social Security Administration — Staging Instance for all SUMs Counts related projects including: Redeterminations/Limited Issue, Continuing Disability Resolution, CDR Performance Measures, Initial...
Recurrence Formulas for Fibonacci Sums
Brandao, Adilson J V
2008-01-01
In this article we present a new recurrence formula for a finite sum involving the Fibonacci sequence. Furthermore, we state an algorithm to compute the sum of a power series related to Fibonacci series, without the use of term-by-term differentiation theorem
Institute of Scientific and Technical Information of China (English)
严长虹
2014-01-01
分布式拒绝服务攻击(DDoS)具有突发性、攻击主机分布广等特点，对其防御尤显困难。从分析 DDoS 攻击原理及常见的防御策略入手，根据非参数 CUSUM 算法，给出了基于流连接密度时间序列分析的 DDoS 攻击防御策略及其模型，并进行了与理论值比较的实验取证。结果表明：该防御模型能够在很大程度上有效防御 DDoS 攻击。%Distributed Denial of Service (DDoS)has features including burstiness and wide distri_bution of attacked host which makes it difficult to defend it.Starting from analysis on the princi_ple of DDoS attack and common defending strategies,this paper gives defending strategy for DDoS attack based on time series analysis of flow connection density and the model according to nonparametric CUSUM algorithm,and carries out experimental evidence comparing with theo_retical values.Results show that the defending model can defend DDoS attack effectively to a large extent.
Cumulative environmental effects. Summary
Energy Technology Data Exchange (ETDEWEB)
NONE
2012-07-01
This report presents a compilation of knowledge about the state of the environment and human activity in the Norwegian part of the North Sea and Skagerrak. The report gives an overview of pressures and impacts on the environment from normal activity and in the event of accidents. This is used to assess the cumulative environmental effects, which factors have most impact and where the impacts are greatest, and to indicate which problems are expected to be most serious in the future. The report is intended to provide relevant information that can be used in the management of the marine area in the future. It also provides input for the identification of environmental targets and management measures for the North Sea and Skagerrak.(Author)
A Self-adaptive Detecting Algorithm Based on CUSUM%基于CUSUM的自适应攻击检测
Institute of Scientific and Technical Information of China (English)
赖会霞; 马剑波; 张仕
2011-01-01
In order to detect DDoS attack in time and accurately, a detecting algorithm based-on CUSUM is proposed. Using the sensitivity of CUSUM algorithm to slight changes, the detecting algorithm take the proportion of sending packets to and outgoing packets from destination address as characteristic value. The algorithm can adjust expectations and alarm-threshold dynamically. It has good adaptability and can be applied to all kinds of network environment. The experimental results and analysis indicate that the algorithm can detect attack rapidly and accurately, also has good adaptability.%为了能够快速发现DDoS攻击,尽量减小或避免其危害,基于CUSUM算法,以发送和接收数据包数量比例为特征量,提出一种快速的DDoS攻击检测算法.并通过动态调整期望值和警告阀值,使算法具有更好的适应性,能够运用于不同的网络环境.最后通过实验对算法进行验证.
UBIQUITOUS POLLUTANTS FROM CUMULATIVE ...
The occurrence of pharmaceuticals and personal care products (PPCPS) as environmental pollutants is a multifaceted issue whose scope continues to become better delineated since the escalation of concerted attention beginning in the 1980s. PPCPs typically occur as trace environmental pollutants (primarily in surface but also in ground waters) as a result of their widespread, continuous, combined usage in a broad range of human and veterinary therapeutic activities and practices. With respect to the risk-assessment paradigm, the growing body of published work has focused primarily on the origin and occurrence of these substances. Comparatively less is known about human and ecological exposure, and even less about the known or even potential hazards associated with exposure to these anthropogenic substances, many of which are highly bioactive. The continually growing, worldwide importance of freshwater resources underscores the need for ensuring that any aggregate or cumulative impacts on water supplies and resultant potential for human or ecological exposure be minimized. This has prompted the more recent investigations on waste treatment processes for one of the major sources of environmental disposition, namely sewage. Despite the paucity of health effects data for long-term, simultaneous exposure to multiple xenobiotics (particularly PPCPS) at low doses (a major toxicological issue that can be described by the
Institute of Scientific and Technical Information of China (English)
2007-01-01
In this paper,we first introduce a concept of L_p-dual Quermassintegral sum function of convex bodies and establish the polar projection Minkowski inequality and the polar projection Aleksandrov-Fenchel inequality for L_p-dual Quermassintegral sums.Moreover,by using Lutwak’s width-integral of index i,we establish the L_p-Brunn-Minkowski inequality for the polar mixed projec- tion bodies.As applications,we prove some interrelated results.
Directory of Open Access Journals (Sweden)
Carlos Polanco
2013-01-01
Full Text Available A severe respiratory disease epidemic outbreak correlates with a high demand of specific supplies and specialized personnel to hold it back in a wide region or set of regions; these supplies would be beds, storage areas, hemodynamic monitors, and mechanical ventilators, as well as physicians, respiratory technicians, and specialized nurses. We describe an online cumulative sum based model named Overcrowd-Severe-Respiratory-Disease-Index based on the Modified Overcrowd Index that simultaneously monitors and informs the demand of those supplies and personnel in a healthcare network generating early warnings of severe respiratory disease epidemic outbreaks through the interpretation of such variables. A post hoc historical archive is generated, helping physicians in charge to improve the transit and future allocation of supplies in the entire hospital network during the outbreak. The model was thoroughly verified in a virtual scenario, generating multiple epidemic outbreaks in a 6-year span for a 13-hospital network. When it was superimposed over the H1N1 influenza outbreak census (2008–2010 taken by the National Institute of Medical Sciences and Nutrition Salvador Zubiran in Mexico City, it showed that it is an effective algorithm to notify early warnings of severe respiratory disease epidemic outbreaks with a minimal rate of false alerts.
Polanco, Carlos; Castañón-González, Jorge Alberto; Macías, Alejandro E; Samaniego, José Lino; Buhse, Thomas; Villanueva-Martínez, Sebastián
2013-01-01
A severe respiratory disease epidemic outbreak correlates with a high demand of specific supplies and specialized personnel to hold it back in a wide region or set of regions; these supplies would be beds, storage areas, hemodynamic monitors, and mechanical ventilators, as well as physicians, respiratory technicians, and specialized nurses. We describe an online cumulative sum based model named Overcrowd-Severe-Respiratory-Disease-Index based on the Modified Overcrowd Index that simultaneously monitors and informs the demand of those supplies and personnel in a healthcare network generating early warnings of severe respiratory disease epidemic outbreaks through the interpretation of such variables. A post hoc historical archive is generated, helping physicians in charge to improve the transit and future allocation of supplies in the entire hospital network during the outbreak. The model was thoroughly verified in a virtual scenario, generating multiple epidemic outbreaks in a 6-year span for a 13-hospital network. When it was superimposed over the H1N1 influenza outbreak census (2008-2010) taken by the National Institute of Medical Sciences and Nutrition Salvador Zubiran in Mexico City, it showed that it is an effective algorithm to notify early warnings of severe respiratory disease epidemic outbreaks with a minimal rate of false alerts.
Directory of Open Access Journals (Sweden)
Franciele A. C. Follador
2012-10-01
Full Text Available The aim of this study was to evaluate the application possibility of tabular CUSUM control charts in the quality control of chemical variables in surface water. It was performed bibliographic and field research to collect water samples from 2003 to 2009, totaling 30 samples, some monthly and others semi-annual in order to observe the variables that regulate water quality. It was found that these charts may be applied to control the quality of river water; showing to be effective in the perception of changes during the process, especially for small samples (n=1 which there is no repetition as in this research. It was also concluded that the Mandurim River does not presents significant levels of pollution.O objetivo do trabalho foi avaliar a possibilidade de aplicação das cartas de controle do tipo CUSUM tabular no controle de qualidade de variáveis químicas em água superficial. Foi realizada pesquisa bibliográfica e de campo com coleta de amostras de água, no período de 2003 até 2009, perfazendo 30 coletas, algumas mensais e outras semestrais, com o intuito de observar as variáveis que regulam a qualidade da água. Verificou-se que estas cartas podem ser aplicadas ao controle de qualidade de água de rio, mostrando ser eficazes na percepção de alterações durante o processo, principalmente para amostras pequenas (n=1, para as quais não há repetição, como é o caso desta pesquisa. Também se concluiu que o Rio Mandurim não apresenta poluição em níveis consideráveis.
New Results On the Sum of Two Generalized Gaussian Random Variables
Soury, Hamza
2015-01-01
We propose in this paper a new method to compute the characteristic function (CF) of generalized Gaussian (GG) random variable in terms of the Fox H function. The CF of the sum of two independent GG random variables is then deduced. Based on this results, the probability density function (PDF) and the cumulative distribution function (CDF) of the sum distribution are obtained. These functions are expressed in terms of the bivariate Fox H function. Next, the statistics of the distribution of the sum, such as the moments, the cumulant, and the kurtosis, are analyzed and computed. Due to the complexity of bivariate Fox H function, a solution to reduce such complexity is to approximate the sum of two independent GG random variables by one GG random variable with suitable shape factor. The approximation method depends on the utility of the system so three methods of estimate the shape factor are studied and presented.
New Results on the Sum of Two Generalized Gaussian Random Variables
Soury, Hamza
2016-01-06
We propose in this paper a new method to compute the characteristic function (CF) of generalized Gaussian (GG) random variable in terms of the Fox H function. The CF of the sum of two independent GG random variables is then deduced. Based on this results, the probability density function (PDF) and the cumulative distribution function (CDF) of the sum distribution are obtained. These functions are expressed in terms of the bivariate Fox H function. Next, the statistics of the distribution of the sum, such as the moments, the cumulant, and the kurtosis, are analyzed and computed. Due to the complexity of bivariate Fox H function, a solution to reduce such complexity is to approximate the sum of two independent GG random variables by one GG random variable with suitable shape factor. The approximation method depends on the utility of the system so three methods of estimate the shape factor are studied and presented [1].
Large even order character sums
Goldmakher, Leo
2012-01-01
A classical theorem of Paley asserts the existence of an infinite family of quadratic characters whose character sums become exceptionally large. In this paper, we establish an analogous result for characters of any fixed even order. Previously our bounds were only known under the assumption of the Generalized Riemann Hypothesis.
Some Alternating Double Binomial Sums
Institute of Scientific and Technical Information of China (English)
ZHENG De-yin; TANG Pei-pei
2013-01-01
We consider some new alternating double binomial sums. By using the Lagrange inversion formula, we obtain explicit expressions of the desired results which are related to a third-order linear recursive sequence. Furthermore, their recursive relation and generating functions are obtained.
Dominguez, C. A.
2013-08-01
A general, and very basic introduction to QCD sum rules is presented, with emphasis on recent issues to be described at length in other papers in this issue. Collectively, these papers constitute the proceedings of the International Workshop on Determination of the Fundamental Parameters of QCD, Singapore, March 2013.
EXTENSIONS OF EULER HARMONIC SUMS
Directory of Open Access Journals (Sweden)
Djurdje Cvijović
2012-10-01
Full Text Available Three new closed-form summation formulae involving harmonic numbers are established using simple arguments and they are very general extensions of Euler’s famous harmonic sum identity. Some illustrative special cases as well as immediate consequences of the main results are also considered.
2010-12-01
21 iid independent and identically distributed ILI Influenza -Like Illness Norm Normal Distribution Probability Density Function Pois Poisson...In epidemiology, is a carrier, especially an animal such as an arthropod that transfers an infective agent from one host to another. Zoonosis : A
CSIR Research Space (South Africa)
Machaka, Pheeha
2015-11-01
Full Text Available request, the server will open a connection session and respond with a SYN_ACK packet; by doing this the server stores details of the requested TCP connection in the memory stack and allocates resources to this open session. The connection remains in a half...-open state, i.e. the SYN_RECVD state. To complete the three-way handshake with the server, the client will need to confirm the connection and respond with an ACK packet. The server will then check the memory stack for an existing connection request...
Mixed exponentially weighted moving average-cumulative sum charts for process monitoring
Abbas, N.; Riaz, M.; Does, R.J.M.M.
2013-01-01
The control chart is a very popular tool of statistical process control. It is used to determine the existence of special cause variation to remove it so that the process may be brought in statistical control. Shewhart-type control charts are sensitive for large disturbances in the process, whereas
A poorly understood weapon languishing in the armoury
Energy Technology Data Exchange (ETDEWEB)
Vesma, Vilnis [Torpy Energy (United Kingdom)
1999-04-01
Cusum is the Cumulative Sum of Deviation and is the difference between the running total for the actual and expected consumption of energy in a building or process. The method can be used for setting and achieving consumption targets, assisting in the diagnosis of persistent excess consumption, and quantifying cumulative savings. Some simple rules for using the method are given. (UK)
带有测量误差的相关数据的CUSUM控制图%The CUSUM Control Chart for the Autocorrelated Data with Measurement Error
Institute of Scientific and Technical Information of China (English)
刘晓红; 王兆军
2009-01-01
As we know, the measurement error often exists in practice, and affects the performance of quality control in some cases. The autoregressive process with the measurement error is investigated in this paper. For detecting the step shift of the autoregressive process mean with measurement error, a CUSUM control chart based on the maximum log-likelihood ratio test is obtained. Simulated in-control and out-of-control ARL's are made for various measurement error and autocorrelation coefficients. The simulation results show that this new CUSUM scheme works well when the process is negatively autocorrelated.%实际中测量误差不仅存在而且在某些情况下还影响质量摔制的表现,本文将考虑带有测量误差的相关数据的监控问题.为检测这类数据的飘移,我们给出了一个基于极大似然比检验的CUSUM控制图及其多种情况下的可控与失控的ARL.模拟结果显示,当过程负相关时,我们提出的CUSUM控制图具有良好的表现.
Borwein, J M; McPhedran, R C
2013-01-01
The study of lattice sums began when early investigators wanted to go from mechanical properties of crystals to the properties of the atoms and ions from which they were built (the literature of Madelung's constant). A parallel literature was built around the optical properties of regular lattices of atoms (initiated by Lord Rayleigh, Lorentz and Lorenz). For over a century many famous scientists and mathematicians have delved into the properties of lattices, sometimes unwittingly duplicating the work of their predecessors. Here, at last, is a comprehensive overview of the substantial body of
BINOMIAL CUSUM VERSUS pn CHART FOR DEFECT DATA%二项变量累积和图vs pn图
Institute of Scientific and Technical Information of China (English)
孟祥新; 廖永平
2000-01-01
累积和(CUSUM)方法是一项成熟、先进的过程质量控制技术,并在发达国家得到了成功应用,但在我国的应用近乎空白.对二项变量累积和控制图及计算平均链长(ARL)的马尔可夫链方法作了简单介绍,计算了CUSUM图和pn图的平均链长,在此基础上对两种方法进行比较,表明CUSUM方法的ARL性能优于pn图,并通过具体实例,进一步论证了CUSUM图在实际应用方面优于pn图.认为在国内企业的质量管理中,应积极推广应用累积和技术,以取得经济效益.
Several Types of CUSUM Charts for Normal Distribution Process%几类正态过程的CUSUM图
Institute of Scientific and Technical Information of China (English)
涂玉娟; 冯士雍
2008-01-01
本文针对呈正态分布的过程数据,讨论当过程参数(μ,σ2)已知或未知时单参数变化、双参数变化的过程控制问题.针对均值朱知情况,利用Quesenberry提出的Q统计量构造了一系列标准化的CUSUM图;对于方差未知时的复杂情形,给出了一种构造更为简单的CUSUM图的方法;对于未知(或不关心)(μ,σ2)中何者变化的特殊情形,文章提出了纯变化的概念,给出了相应统计量及由该统计量构造的CUSUM-D图,针对每个考虑的情形,通过模拟计算本文给出了相应于统计量的条件期望延时(CED),同时在文章最后给出了本文提出的CUSUM图与已有的CUSUM图(Q图)的模拟比较,结果表明新的CUSUM图是可行的.
The Orbital Angular Momentum Sum Rule
Aslan, Fatma; Burkardt, Matthias
2015-10-01
As an alternative to the Ji sum rule for the quark angular momentum, a sum rule for the quark orbital angular momentum, based on a twist-3 generalized parton distribution, has been suggested. We study the validity of this sum rule in the context of scalar Yukawa interactions as well as in QED for an electron.
CONVERGENCE RATE OFDISTRIBUTIONS OF TRIMMED SUMS
Institute of Scientific and Technical Information of China (English)
QIYONGCHENG; CHENGSHIHONG
1996-01-01
The authors first derive the normal expansion of the joint density function of two orderstatistics from the uniform distribution and then, using the approximation, establish a wayto estimate the normal convergence rate for trimmed sums. For applications, the convergence rates for the intermediately trimmed sums and heavily trimmed sums are found out.
Cumulant expansions for atmospheric flows
Ait-Chaalal, Farid; Meyer, Bettina; Marston, J B
2015-01-01
The equations governing atmospheric flows are nonlinear, and consequently the hierarchy of cumulant equations is not closed. But because atmospheric flows are inhomogeneous and anisotropic, the nonlinearity may manifests itself only weakly through interactions of mean fields with disturbances such as thermals or eddies. In such situations, truncations of the hierarchy of cumulant equations hold promise as a closure strategy. We review how truncations at second order can be used to model and elucidate the dynamics of turbulent atmospheric flows. Two examples are considered. First, we study the growth of a dry convective boundary layer, which is heated from below, leading to turbulent upward energy transport and growth of the boundary layer. We demonstrate that a quasilinear truncation of the equations of motion, in which interactions of disturbances among each other are neglected but interactions with mean fields are taken into account, can successfully capture the growth of the convective boundary layer. Seco...
Electro-cumulation CNF project
Grishin, V G
2000-01-01
bound or free ion current within solid substances; non-plain symmetry; cumulation of the ion interaction. Experimental result: an Ice SuperPolarization. Cold nuclear fusion ? At http://www.shortway.to/to2084 . Keywords: ion, current, solid, symmetry, cumulation, cold nuclear fusion, polarization, depolarization, ionic conductor, superionic conductor, ice, crystal, strain, V-center, V-centre, doped crystal, interstitial impurity, intrinsic color center, high pressure technology, Bridgman, experiment, crowdion, dielectric, proton, layer, defect, lattice, dynamics, electromigration, mobility, muon catalysis, concentration, doping, dopant, conductivity, pycnonuclear reaction, permittivity, dielectric constant, point defects, interstitials, polarizability, imperfection, defect centers, glass, epitaxy, sodium hydroxide, metallic substrate, crystallization, point, tip, susceptibility, ferroelectric, ordering, force, correlation, collective, shift, distortion, coalescence, crowdions, electrolysis.
2009-01-01
JUSTIFICATIVA E OBJETIVOS: As curvas de aprendizado têm se mostrado ferramentas úteis no monitoramento do desempenho de um trabalhador submetido a uma nova tarefa. Essas curvas vêm sendo utilizadas na avaliação de vários procedimentos na prática médica. O objetivo desta pesquisa foi avaliar o aprendizado da intubação orotraqueal (IOT) com o laringoscópio Truview EVO2® através da curva de aprendizado CUSUM. MÉTODO: Quatro aprendizes realizaram o treinamento da IOT com o laringoscópio Truview E...
Directory of Open Access Journals (Sweden)
Ingo Klein
2016-07-01
Full Text Available A new kind of entropy will be introduced which generalizes both the differential entropy and the cumulative (residual entropy. The generalization is twofold. First, we simultaneously define the entropy for cumulative distribution functions (cdfs and survivor functions (sfs, instead of defining it separately for densities, cdfs, or sfs. Secondly, we consider a general “entropy generating function” φ, the same way Burbea et al. (IEEE Trans. Inf. Theory 1982, 28, 489–495 and Liese et al. (Convex Statistical Distances; Teubner-Verlag, 1987 did in the context of φ-divergences. Combining the ideas of φ-entropy and cumulative entropy leads to the new “cumulative paired φ-entropy” ( C P E φ . This new entropy has already been discussed in at least four scientific disciplines, be it with certain modifications or simplifications. In the fuzzy set theory, for example, cumulative paired φ-entropies were defined for membership functions, whereas in uncertainty and reliability theories some variations of C P E φ were recently considered as measures of information. With a single exception, the discussions in the scientific disciplines appear to be held independently of each other. We consider C P E φ for continuous cdfs and show that C P E φ is rather a measure of dispersion than a measure of information. In the first place, this will be demonstrated by deriving an upper bound which is determined by the standard deviation and by solving the maximum entropy problem under the restriction of a fixed variance. Next, this paper specifically shows that C P E φ satisfies the axioms of a dispersion measure. The corresponding dispersion functional can easily be estimated by an L-estimator, containing all its known asymptotic properties. C P E φ is the basis for several related concepts like mutual φ-information, φ-correlation, and φ-regression, which generalize Gini correlation and Gini regression. In addition, linear rank tests for scale that
The hybrid mean value of Dedekind sums and two-term exponential sums
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Leran Chang
2016-01-01
Full Text Available In this paper, we use the mean value theorem of Dirichlet L-functions, the properties of Gauss sums and Dedekind sums to study the hybrid mean value problem involving Dedekind sums and the two-term exponential sums, and give an interesting identity and asymptotic formula for it.
Institute of Scientific and Technical Information of China (English)
金浩; 田铮
2009-01-01
This paper analyzes the problem of testing for parameters change in ARCH errors models with deterministic trend based on residual cusum test. It is shown that the asymptotically limiting distribution of the residual cusum test statistic is still the sup of a standard Brownian bridge under null hypothesis. In order to check this, we carry out a Monte Carlo simulation and examine the return of IBM data. The results from both simulation and real data analysis support our claim. We also can explain this phenomenon from a theoretical viewpoint that the variance in ARCH model in mainly determined by its parameters.
Deacon, A J; Melhuishi, N S; Terblanche, N C S
2014-07-01
Spinal ultrasonography is a promising aid for epidural insertion. We aimed to determine the learning curve of spinal ultrasonography tasks and the number of training scans required to reach competency after undergoing standardised step-wise teaching. Trainees were required to complete a minimum of 60 assessed scans on selected non-pregnant models following attendance at two training sessions, with feedback from an expert after each scan. Learning curves were plotted using the non-risk cumulative summation technique and an acceptable failure rate of 20%. Five trainees completed between 65 and 75 scans each. All trainees were competent at identifying a randomly assigned intervertebral space after a median of five scans (range one to nine) and at measuring the depth from skin to the posterior complex after a median of 10 scans (range 1 to 42). Two trainees were competent at marking an ideal needle insertion point after 55 scans, while three trainees did not attain competency. All trainees were competent after 60 scans if the tolerance was changed from five to eight millimetre for marking the needle insertion point. The average time taken to complete a scan was 163 seconds. Our study showed that after a standardised educational intervention, anaesthetic trainees are able to identify a lumbar interlaminar space easily and can measure the depth to the posterior complex after a reasonable number of additional practice scans, but experienced difficulty accurately marking the needle insertion point whilst using spinal ultrasonography. We confirmed that it was hard to achieve competency in all aspects of spinal ultrasonography, based on assessment using our predefined competency criteria.
Determinant Sums for Undirected Hamiltonicity
Björklund, Andreas
2010-01-01
We present a Monte Carlo algorithm for Hamiltonicity detection in an $n$-vertex undirected graph running in $O^*(1.657^{n})$ time. To the best of our knowledge, this is the first superpolynomial improvement on the worst case runtime for the problem since the $O^*(2^n)$ bound established for TSP almost fifty years ago (Bellman 1962, Held and Karp 1962). It answers in part the first open problem in Woeginger's 2003 survey on exact algorithms for NP-hard problems. For bipartite graphs, we improve the bound to $O^*(1.414^{n})$ time. Both the bipartite and the general algorithm can be implemented to use space polynomial in $n$. We combine several recently resurrected ideas to get the results. Our main technical contribution is a new reduction inspired by the algebraic sieving method for $k$-Path (Koutis ICALP 2008, Williams IPL 2009). We introduce the Labeled Cycle Cover Sum in which we are set to count weighted arc labeled cycle covers over a finite field of characteristic two. We reduce Hamiltonicity to Labeled ...
The Algebra of the Cumulative Percent Operation.
Berry, Andrew J.
2002-01-01
Discusses how to help students avoid some pervasive reasoning errors in solving cumulative percent problems. Discusses the meaning of ."%+b%." the additive inverse of ."%." and other useful applications. Emphasizes the operational aspect of the cumulative percent concept. (KHR)
Adaptive strategies for cumulative cultural learning.
Ehn, Micael; Laland, Kevin
2012-05-21
The demographic and ecological success of our species is frequently attributed to our capacity for cumulative culture. However, it is not yet known how humans combine social and asocial learning to generate effective strategies for learning in a cumulative cultural context. Here we explore how cumulative culture influences the relative merits of various pure and conditional learning strategies, including pure asocial and social learning, critical social learning, conditional social learning and individual refiner strategies. We replicate the Rogers' paradox in the cumulative setting. However, our analysis suggests that strategies that resolved Rogers' paradox in a non-cumulative setting may not necessarily evolve in a cumulative setting, thus different strategies will optimize cumulative and non-cumulative cultural learning.
"Buddha's Light" of Cumulative Particles
Kopeliovich, Vladimir B; Potashnikova, Irina K
2014-01-01
We show analytically that in the cumulative particles production off nuclei multiple interactions lead to a glory-like backward focusing effect. Employing the small phase space method we arrived at a characteristic angular dependence of the production cross section $d\\sigma \\sim 1/ \\sqrt {\\pi - \\theta}$ near the strictly backward direction. This effect takes place for any number $n\\geq 3 $ of interactions of rescattered particle, either elastic or inelastic (with resonance excitations in intermediate states), when the final particle is produced near corresponding kinematical boundary. Such a behaviour of the cross section near the backward direction is in qualitative agreement with some of available data.
A Resource Cost Aware Cumulative
Simonis, Helmut; Hadzic, Tarik
We motivate and introduce an extension of the well-known cumulative constraint which deals with time and volume dependent cost of resources. Our research is primarily interested in scheduling problems under time and volume variable electricity costs, but the constraint equally applies to manpower scheduling when hourly rates differ over time and/or extra personnel incur higher hourly rates. We present a number of possible lower bounds on the cost, including a min-cost flow, different LP and MIP models, as well as greedy algorithms, and provide a theoretical and experimental comparison of the different methods.
Cumulative social disadvantage and child health.
Bauman, Laurie J; Silver, Ellen J; Stein, Ruth E K
2006-04-01
Disparities in child health are a major public health concern. However, it is unclear whether these are predominantly the result of low income, race, or other social risk factors that may contribute to their health disadvantage. Although others have examined the effects of the accumulation of risk factors, this methodology has not been applied to child health. We tested 4 social risk factors (poverty, minority race/ethnicity, low parental education, and not living with both biological parents) to assess whether they have cumulative effects on child health and examined whether access to health care reduced health disparities. We analyzed data on 57,553 children low parental education, and single-parent household) were consistently associated with child health. These were summed, generating the Social Disadvantage Index (range: 0-3). A total of 43.6% of children had no social disadvantages, 30.8% had 1, 15.6% had 2, and 10.0% had all 3. Compared with those with no social disadvantages, the odds ratios (ORs) of being in "good, fair, or poor health" (versus "excellent or very good") were 1.95 for 1 risk, 3.22 for 2 risks, and 4.06 for 3 risks. ORs of having a chronic condition increased from 1.25 (1 risk) to 1.60 (2 risks) to 2.11 (3 risks). ORs for activity limitation were 1.51 (1 risk) to 2.14 (2 risks) and 2.88 (3 risks). Controlling for health insurance did not affect these findings. The accumulation of social disadvantage among children was strongly associated with poorer child health and having insurance did not reduce the observed health disparities.
Parameterized Telescoping Proves Algebraic Independence of Sums
Schneider, Carsten
2008-01-01
Usually creative telescoping is used to derive recurrences for sums. In this article we show that the non-existence of a creative telescoping solution, and more generally, of a parameterized telescoping solution, proves algebraic independence of certain types of sums. Combining this fact with summation-theory shows transcendence of whole classes of sums. Moreover, this result throws new light on the question why, e.g., Zeilberger's algorithm fails to find a recurrence with minimal order.
Cumulative Phenomena through the Quark-Parton Diagram Summation at Thresholds
Braun, M A
1998-01-01
A microscopic treatment of cumulative phenomena based on perturbative QCD calculations of the corresponding quark diagrams near the threshold is presented. To sum all diagrams like these the special technique based on the recurrence relations was developed. The x-behaviour of the nuclear structure function $F_{2}(x)$ in the cumulative region x>1 was found to be roughly exponential, governed by an effective coupling constant, which depends on the QCD coupling constant and quark mass. Two mechanisms for cumulative particle production, direct and spectator ones, were analysed. It was shown that due to final state interactions the leading terms of the direct mechanism contribution are cancelled and the spectator mechanism is the dominant one. It leads to a smaller slope of the particle production rates compared to the slope of the nuclear structure function in the cumulative region, in agreement with the recent experimental data. The slope difference is due to additional multiple interactions between nuclear and ...
A paradox of cumulative culture.
Kobayashi, Yutaka; Wakano, Joe Yuichiro; Ohtsuki, Hisashi
2015-08-21
Culture can grow cumulatively if socially learnt behaviors are improved by individual learning before being passed on to the next generation. Previous authors showed that this kind of learning strategy is unlikely to be evolutionarily stable in the presence of a trade-off between learning and reproduction. This is because culture is a public good that is freely exploited by any member of the population in their model (cultural social dilemma). In this paper, we investigate the effect of vertical transmission (transmission from parents to offspring), which decreases the publicness of culture, on the evolution of cumulative culture in both infinite and finite population models. In the infinite population model, we confirm that culture accumulates largely as long as transmission is purely vertical. It turns out, however, that introduction of even slight oblique transmission drastically reduces the equilibrium level of culture. Even more surprisingly, if the population size is finite, culture hardly accumulates even under purely vertical transmission. This occurs because stochastic extinction due to random genetic drift prevents a learning strategy from accumulating enough culture. Overall, our theoretical results suggest that introducing vertical transmission alone does not really help solve the cultural social dilemma problem. Copyright © 2015 Elsevier Ltd. All rights reserved.
改进的CUSUM网络流量异常检测%Abnormal Detection on Network Traffic Based on the Improved CUSUM
Institute of Scientific and Technical Information of China (English)
邓绯; 韩文智; 朱倩; 钱立
2014-01-01
The network is an integral part in people living and learning. It is an assurance of a normal network running how to be able to detect the abnormal network traffic accurately and fast, and to make a reasonable response. This paper put forward the algorithm for an abnormal network traffic detection based on the improved CUSUM, it was improved through two parts of the warning judgement and improvement constraints according to the detection algorithm. Finally, experimental results showed that CUSUM algorithm was a simple, had a great of improvement in the aspects of improving traffic abnormal detection false positive negative rate.%网络已是人们学习生活不可缺少的一部分，如何能够准确、快速地检测出网络流量异常，并做出合理的响应，是网络正常运行的保证。本文提出改进的CUSUM流量异常检测算法，通过对CUSUM算法对网络流量进行检测，在警告判断条件和增加约束条件两方面进行改进。最后实验结果表明，CUSUM算法实现简单，在提高异常流量检测的误报率和漏报率方面有较大改进。
Some Finite Sums Involving Generalized Fibonacci and Lucas Numbers
Directory of Open Access Journals (Sweden)
E. Kılıç
2011-01-01
Full Text Available By considering Melham's sums (Melham, 2004, we compute various more general nonalternating sums, alternating sums, and sums that alternate according to (−12+1 involving the generalized Fibonacci and Lucas numbers.
The BFKL Pomeron calculus: Summing enhanced diagrams
Energy Technology Data Exchange (ETDEWEB)
Levin, E., E-mail: leving@post.tau.ac.il [Department of Particle Physics, School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel); Departamento de Fisica, Universidad Tecnica Federico Santa Maria, and Centro Cientifico-Tecnologico de Valparaiso, Casilla 110-V, Valparaiso (Chile); Miller, J., E-mail: jeremy.miller@ist.utl.pt [Department of Particle Physics, School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel); CENTRA, Departamento de Fisica, Instituto Superior Tecnico (IST), Av. Rovisco Pais, 1049-001 Lisboa (Portugal)
2012-07-01
The goal of this paper is to sum over a class of enhanced diagrams, and derive a new Pomeron Green function. It is found that this sum gives the Pomeron contribution to the scattering amplitude that decreases with energy. In other words, we found that the total cross section of two colourless dipoles of small but equal sizes, falls down at high energies.
Magnetic Dipole Sum Rules for Odd Nuclei
Ginocchio, J N
1997-01-01
Sum rules for the total- and scissors-mode M1 strength in odd-A nuclei are derived within the single-j interacting boson-fermion model. We discuss the physical content and geometric interpretation of these sum rules and apply them to ^{167}Er and ^{161}Dy. We find consistency with the former measurements but not with the latter.
The package HarmonicSums: Computer Algebra and Analytic aspects of Nested Sums
Ablinger, Jakob
2014-01-01
This paper summarizes the essential functionality of the computer algebra package HarmonicSums. On the one hand HarmonicSums can work with nested sums such as harmonic sums and their generalizations and on the other hand it can treat iterated integrals of the Poincare and Chen-type, such as harmonic polylogarithms and their generalizations. The interplay of these representations and the analytic aspects are illustrated by concrete examples.
A New Sum Analogous to Gauss Sums and Its Fourth Power Mean
Directory of Open Access Journals (Sweden)
Shaofeng Ru
2014-01-01
Full Text Available The main purpose of this paper is to use the analytic methods and the properties of Gauss sums to study the computational problem of one kind of new sum analogous to Gauss sums and give an interesting fourth power mean and a sharp upper bound estimate for it.
A new sum analogous to Gauss sums and its fourth power mean.
Ru, Shaofeng; Zhang, Wenpeng
2014-01-01
The main purpose of this paper is to use the analytic methods and the properties of Gauss sums to study the computational problem of one kind of new sum analogous to Gauss sums and give an interesting fourth power mean and a sharp upper bound estimate for it.
A hybrid mean value related to the Dedekind sums and Kloosterman sums
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
The main purpose of this paper is using the properties of character sum and the analytic method to study a hybrid mean value problem related to the Dedekind sums and Kloosterman sums,and give some interesting mean value formulae and identities for it.
Optimal sequential change-detection for fractional stochastic differential equations
Chronopoulou, Alexandra
2011-01-01
The sequential detection of an abrupt and persistent change in the dynamics of an arbitrary continuous-path stochastic process is considered; the optimality of the cumulative sums (CUSUM) test is established with respect to a modified Lorden's criterion. As a corollary, sufficient conditions are obtained for the optimality of the CUSUM test when the observed process is described by a fractional stochastic differential equation. Moreover, a novel family of model-free, Lorden-like criteria is introduced and it is shown that these criteria are optimized by the CUSUM test when a fractional Brownian motion adopts a polynomial drift. Finally, a modification of the continuous-time CUSUM test is proposed for the case that only discrete-time observations are available.
Private Decayed Sum Estimation under Continual Observation
Bolot, Jean; Muthukrishnan, S; Nikolov, Aleksandar; Taft, Nina
2011-01-01
Motivated by monitoring applications, recently, Dwork et al. initiated the study of differential privacy as data is continually updated over time. They abstracted the problem of running sums that is applicable widely, and proved upper and lower bounds on accuracy of \\epsilon - differentially private algorithms for this problem. We continue their study, but we are motivated by the reality that in many monitoring applications, recent data is more important than distant data. Thus, we study the sums problem for well known decay models of data, from window to exponential and polynomial decay. Such "decayed sums" are challenging because (a) while we want accuracy in analysis with respect to the window or decayed sum, we still want differential privacy; (b) sums within windows and decayed sums in general are not monotonic or even near-monotonic as studied in the work of Dwork et al. We present algorithms for decayed sum in each model which are \\epsilon-differentially private, and are accurate. For window and expone...
Dai, Y B; Dai, Yuan-Ben; Zhu, Shi-Lin
2006-01-01
We derive a new QCD sum rule for $D(0^+)$ which has only the $D\\pi$ continuum with a resonance in the hadron side, using the assumption similar to that has been successfully used in our previous work to the mass of $D_s(0^+)(2317)$. For the value of the pole mass $M_c=1.38 $ GeV as used in the $D_s(0^+)$ case we find that the mass of $D(0^+)$ derived from this sum rule is significantly lower than that derived from the sum rule with the pole approximation. Our result is in agreement with the experimental dada from Belle.
Directory of Open Access Journals (Sweden)
Irene Machado
2008-11-01
Full Text Available Nem sempre os temas candentes da investigação, numa determinada área do conhecimento, são colocados de maneira orgânica e organizada para o conjunto dos pesquisadores que sobre eles se debruçam. Quase nunca as edições cientícas, que se propõem a torná-los acessíveis a seus leitores, conseguem harmonizá-los sem correr os riscos de aproximações indevidas. A única forma de não incorrer em equívocos perigosos é assumir a idiossincrasia do temário diversificado que constitui o campo em questão. O leitor que ora inicia seu diálogo com este sétimo número de Galáxia não deve tomar esse preâmbulo por alerta, mas sim como tentativa de a revista manter a coerência face a seu compromisso de ser porta-voz dos temas e problemas da comunicação e da cultura pelo prisma das teorias semióticas que orientam o olhar dos vários colaboradores que encontram neste espaço uma tribuna aberta ao trânsito das diferenças. Basta um relance pelo sumário desta edição para que tal armação possa ser confirmada. Os textos que constituem o Fórum, respeitadas as singularidades, tratam de temas que são caros para as abordagens da comunicação e da semiótica na cultura. Temos o privilégio de publicar o texto inédito em português de Jakob von Uexküll em que o autor apresenta sua teoria da Umwelt, caracterizando formulações da biossemiótica sobre o signi.cado do entorno ou do espaço circundante, que são valiosas para compreender a percepção, a interação, o contexto, a informação, os códigos em ambientes de semiose. De um outro lugar - aquele modulado pela lógica da linguagem - Lucrécia Ferrara perscruta o campo conceitual que entende o design não pelo viés da operatividade, mas como processo semiótico-cognitivo. A outra ponta deste que pode ser um triálogo nos é dado pela comunicologia de Vilém Flusser. Para Michael Hanke, Flusser foi um dos grandes teóricos a investigar a importância da mídia para os
Generalized Thomas-Reiche-Kuhn sum rule
Zhou, Bing-Lu; Zhu, Jiong-Ming; Yan, Zong-Chao
2006-01-01
The generalized Thomas-Reiche-Kuhn sum rule is established for any Coulombic system with arbitrary masses and charges of its constituent particles. Numerical examples are given for the hydrogen molecular ions.
The generalized GDH sum for He-3
Energy Technology Data Exchange (ETDEWEB)
Karl Slifer
2004-06-02
The Burkhardt-Cottingham, Bjorken and generalized GDH sum rules are all consequences of the Q^2-dependent dispersion relations for the virtual photon Compton amplitudes. These integrals are investigated for a He-3 target at low Q^2.
A method to compute periodic sums
Gumerov, Nail A
2013-01-01
In a number of problems in computational physics, a finite sum of kernel functions centered at $N$ particle locations located in a box in three dimensions must be extended by imposing periodic boundary conditions on box boundaries. Even though the finite sum can be efficiently computed via fast summation algorithms, such as the fast multipole method (FMM), the periodized extension is usually treated via a different algorithm, Ewald summation, accelerated via the fast Fourier transform (FFT). A different approach to compute this periodized sum just using a blackbox finite fast summation algorithm is presented in this paper. The method splits the periodized sum in to two parts. The first, comprising the contribution of all points outside a large sphere enclosing the box, and some of its neighbors, is approximated inside the box by a collection of kernel functions ("sources") placed on the surface of the sphere or using an expansion in terms of spectrally convergent local basis functions. The second part, compri...
Certain Binomial Sums with recursive coefficients
Kilic, Emrah
2010-01-01
In this short note, we establish some identities containing sums of binomials with coefficients satisfying third order linear recursive relations. As a result and in particular, we obtain general forms of earlier identities involving binomial coefficients and Fibonacci type sequences.
On Learning Ring-Sum-Expansions
DEFF Research Database (Denmark)
Fischer, Paul; Simon, H. -U.
1992-01-01
The problem of learning ring-sum-expansions from examples is studied. Ring-sum-expansions (RSE) are representations of Boolean functions over the base {#123;small infinum, (+), 1}#125;, which reflect arithmetic operations in GF(2). k-RSE is the class of ring-sum-expansions containing only monomials...... of a 2-CNF and a 1-DNF. Finally the paper presents learning (on-line prediction) algorithms for k-RSE that are optimal with respect to the sample size (worst case mistake bound)...... of length at most k:. term-RSE is the class of ring-sum-expansions having at most I: monomials. It is shown that k-RSE, k>or=1, is learnable while k-term-RSE, k>2, is not learnable if RPnot=NP. Without using a complexity-theoretical hypothesis, it is proven that k-RSE, k>or=1, and k-term-RSE, k>or=2 cannot...
A branch-and-cut-and-price algorithm for the cumulative capacitated vehicle routing problem
DEFF Research Database (Denmark)
Wøhlk, Sanne; Lysgaard, Jens
2014-01-01
The paper considers the Cumulative Capacitated Vehicle Routing Problem (CCVRP), which is a variation of the well-known Capacitated Vehicle Routing Problem (CVRP). In this problem, the traditional objective of minimizing total distance or time traveled by the vehicles is replaced by minimizing the...... the sum of arrival times at the customers. A branch-and-cut-and-price algorithm for obtaining optimal solutions to the problem is proposed. Computational results based on a set of standard CVRP benchmarks are presented....
Sum rules in the oscillator radiation processes
Energy Technology Data Exchange (ETDEWEB)
Casana, R. [Instituto de Fisica Teorica-IFT/UNESP, Rua Pamplona 145, 01405-900 Sao Paulo, SP (Brazil)]. E-mail: casana@ift.unesp.br; Flores-Hidalgo, G. [Instituto de Fisica Teorica-IFT/UNESP, Rua Pamplona 145, 01405-900 Sao Paulo, SP (Brazil)]. E-mail: gflores@ift.unesp.br; Pimentel, B.M. [Instituto de Fisica Teorica-IFT/UNESP, Rua Pamplona 145, 01405-900 Sao Paulo, SP (Brazil)]. E-mail: pimentel@ift.unesp.br
2005-03-28
We consider the problem of a harmonic oscillator coupled to a scalar field in the framework of recently introduced dressed coordinates. We compute all the probabilities associated with the decay process of an excited level of the oscillator. Instead of doing direct quantum mechanical calculations we establish some sum rules from which we infer the probabilities associated to the different decay processes of the oscillator. Thus, the sum rules allows to show that the transition probabilities between excited levels follow a binomial distribution.
Sum rules in the oscillator radiation processes
Casana, R.; Flores-Hidalgo, G.; Pimentel, B. M.
2005-03-01
We consider the problem of a harmonic oscillator coupled to a scalar field in the framework of recently introduced dressed coordinates. We compute all the probabilities associated with the decay process of an excited level of the oscillator. Instead of doing direct quantum mechanical calculations we establish some sum rules from which we infer the probabilities associated to the different decay processes of the oscillator. Thus, the sum rules allows to show that the transition probabilities between excited levels follow a binomial distribution.
Structural relations between nested harmonic sums
Energy Technology Data Exchange (ETDEWEB)
Bluemlein, J.
2008-07-15
We describe the structural relations between nested harmonic sums emerging in the description of physical single scale quantities up to the 3-loop level in renormalizable gauge field theories. These are weight w=6 harmonic sums. We identify universal basic functions which allow to describe a large class of physical quantities and derive their complex analysis. For the 3-loop QCD Wilson coefficients 35 basic functions are required, whereas a subset of 15 describes the 3-loop anomalous dimensions. (orig.)
Trigonometric sums in number theory and analysis
Karatsuba, Anatoly A; Chubarikov, Vladimir N; Shishkova, Maria
2004-01-01
The book presents the theory of multiple trigonometric sums constructed by the authors. Following a unified approach, the authors obtain estimates for these sums similar to the classical I. M. Vinogradov´s estimates and use them to solve several problems in analytic number theory. They investigate trigonometric integrals, which are often encountered in physics, mathematical statistics, and analysis, and in addition they present purely arithmetic results concerning the solvability of equations in integers.
Cumulate Fragments in Silicic Ignimbrites
Bachmann, O.; Ellis, B. S.; Wolff, J.
2014-12-01
Increasingly, studies are concluding that silicic ignimbrites are the result of the amalgamation of multiple discrete magma batches. Yet the existence of discrete batches presents a conundrum for magma generation and storage; if silicic magma batches are not generated nearly in situ in the upper crust, they must traverse, and reside within, a thermally hostile environment with large temperature gradients, resulting in low survivability in their shallow magmatic hearths. The Snake River Plain (Idaho, USA) is a type example of this 'multi-batch' assembly with ignimbrites containing multiple populations of pyroxene crystals, glass shards, and crystal aggregates. The ubiquitous crystal aggregates hint at a mechanism to facilitate the existence of multiple, relatively small batches of rhyolite in the upper crust. These aggregates contain the same plagioclase, pyroxene, and oxide mineral compositions as single phenocrysts of the same minerals in their host rocks, but they have significantly less silicic bulk compositions and lack quartz and sanidine, which occur as single phenocrysts in the deposits. This implies significant crystallization followed by melt extraction from mushy reservoir margins. The extracted melt then continues to evolve (crystallizing sanidine and quartz) while the melt-depleted margins provide an increasingly rigid and refractory network segregating the crystal-poor batches of magma. The hot, refractory, margins insulate the crystal-poor lenses, allowing (1) extended residence in the upper crust, and (2) preservation of chemical heterogeneities among batches. In contrast, systems that produce cumulates richer in low-temperature phases (quartz, K-feldspars, and/or biotite) favour remelting upon recharge, leading to less segregation of eruptible melt pockets and the formation of gradationally zoned ignimbrites. The occurrence of similar crystal aggregates from a variety of magmatic lineages suggests the generality of this process.
Deel, Lindsay N.
Eastern forests experience a range of disturbance events over time, from stand-replacing disturbances, such as clear cuts, to ephemeral disturbances, such as insect outbreaks. By understanding the cumulative impact of disturbances on canopy structure and chemistry, we can gain insight into management strategies, assess a variety of ecosystem services, and even contribute to a larger body of knowledge on global climate change. I transformed a series of Landsat images spanning approximately 25 years into cumulative disturbance maps covering Green Ridge State Forest and Savage River State Forest in western Maryland. Intensive field surveys collected during the summer of 2009 provided measurements of canopy N and estimates of canopy cover, understory cover, and leaf cover. I used AVIRIS imagery flown concurrently with field data collection to map canopy nitrogen across both forests. Through this project, I tested the impact of cumulative disturbance on forest canopy cover and canopy nitrogen. I found that increased values of cumulative disturbance had a measurable negative impact on forest canopy structure and canopy nitrogen. Moreover, by testing varying methods of summing cumulative disturbance, I found that past disturbances diminish over time in importance, yet still influence the current canopy structure and canopy N of a forest. Thus, my study suggests that Landsat time series data can be synthesized into cumulative metrics incorporating multiple disturbance types, which help explain important disturbance-mediated changes in ecosystem functions.
Institute of Scientific and Technical Information of China (English)
程军; 林白; 芦建芝; 李鸥
2006-01-01
针对危害性极大的SYN Flooding攻击,提出了一种新的检测方法.该方法监控进入网络的TCP业务的SYN包与FIN(RsT)包的平衡性,并使用非参数累积和(CUSUM)算法来检测SYN包与FIN(RST)包数量的均衡性的变化.该方法不需要正常业务和攻击业务的详细模型,能提高检测的准确性和在线检测速度,降低运算开销.
Institute of Scientific and Technical Information of China (English)
严长虹
2014-01-01
分布式拒绝服务攻击（DDoS）具有突发性、攻击主机分布广等特点，对其防御尤显困难。从分析 DDoS 攻击原理及常见的防御策略入手，根据非参数 CUSUM 算法，给出了基于流连接密度时间序列分析的 DDoS 攻击防御策略及其模型，并进行了与理论值比较的实验取证。结果表明：该防御模型能够在很大程度上有效防御 DDoS 攻击。
Directory of Open Access Journals (Sweden)
Francisco Eljach
2006-01-01
Full Text Available Debido a la globalización y las actuales tendencias de la economía, las organizaciones han orientado sus estrategias hacia el mejoramiento de la calidad y a la reducción de los costos de fabricación. Esta investigación busca detectar las situaciones fuera de control que se puedan presentara al monitorear un proceso y tomar decisiones orientadas a mejorar la calidad y disminuir los costos asociadas a la misma. Esto se logrará mediante un programa computacional que permite simular el comportamiento de las cartas X, CUSUM y EWMA y el uso de diferentes reglas de detención y el uso de diferentes reglas de detención y teniendo en cuenta la magnitud del cambio y los costos de calidad asociados.
Cumulative human impacts on marine predators
DEFF Research Database (Denmark)
Maxwell, Sara M; Hazen, Elliott L; Bograd, Steven J
2013-01-01
Stressors associated with human activities interact in complex ways to affect marine ecosystems, yet we lack spatially explicit assessments of cumulative impacts on ecologically and economically key components such as marine predators. Here we develop a metric of cumulative utilization and impact...
一种适用于认知超宽带的CUSUM频谱感知算法%Novel CUSUM spectrum sensing algorithm in cognitive UWB
Institute of Scientific and Technical Information of China (English)
宋晓鸥; 向新; 毕笃彦; 陈顺方
2011-01-01
A novel Cognitive UWB spectrum sensing algorithm is proposed and evaluated, which enables the detection of the low average SNR and low duty ratio signal with low complexity and small detection delay. An uniform probability density function of the low duty ratio received signal is constructed based on the characteristic of the UWB pulse signal. CUSUM test is introduced to implement the detection. Theoretical analysis indicates that the proposed algorithm is suitable for low duty ratio signal detection. Compared with the energy detection algorithm, the proposed algorithm conquers the SNR wall phenomenon, with superior detection delay performance. Furthermore, the theoretical analysis results are proved by simulations.%提出了一种新的认知超宽带频谱感知算法,该算法适合检测低平均信噪比、低占空比的超宽带脉冲信号,且具有复杂度低、检测延迟性能优越的特点.论文根据超宽带脉冲信号特性,给出形式统一的低占空比接收信号概率密度函数表达式,并采用累加和(CUSUM)算法实施检测.仿真结果表明,该算法对低占空比信号具有良好的适应性,有效克服了能量检测的信噪比门限效应,且检测延迟性能优越.
DEFF Research Database (Denmark)
Søeborg, T; Frederiksen, H; Andersson, Anna-Maria
2012-01-01
and adolescents and resulting estimated daily intakes of four different phthalates. These daily intake estimates are used for a cumulative risk assessment with anti-androgenic effects as the endpoint using Tolerable Daily Intake (TDI) values determined by the European Food Safety Authorities (EFSA) or Reference...... endpoint for the phthalates included in this article. Using the EFSA TDI values, 12 children exceeded the hazard quotient for the sum of di-n-butyl phthalate and di-iso-butyl phthalate (∑DBP((i+n)) ) and one child exceeded the hazard quotient for di-(2-ethylhexyl)phthalate (DEHP). Nineteen children...... exceeded the cumulated hazard index for three phthalates. Using the RfD AA values, one child exceeded the hazard quotient for DEHP and the same child exceeded the cumulated hazard index for four phthalates. The EFSA TDI approach thus is more restrictive and identifies ∑DBP((i+n)) as the compound...
Model-checking techniques based on cumulative residuals.
Lin, D Y; Wei, L J; Ying, Z
2002-03-01
Residuals have long been used for graphical and numerical examinations of the adequacy of regression models. Conventional residual analysis based on the plots of raw residuals or their smoothed curves is highly subjective, whereas most numerical goodness-of-fit tests provide little information about the nature of model misspecification. In this paper, we develop objective and informative model-checking techniques by taking the cumulative sums of residuals over certain coordinates (e.g., covariates or fitted values) or by considering some related aggregates of residuals, such as moving sums and moving averages. For a variety of statistical models and data structures, including generalized linear models with independent or dependent observations, the distributions of these stochastic processes tinder the assumed model can be approximated by the distributions of certain zero-mean Gaussian processes whose realizations can be easily generated by computer simulation. Each observed process can then be compared, both graphically and numerically, with a number of realizations from the Gaussian process. Such comparisons enable one to assess objectively whether a trend seen in a residual plot reflects model misspecification or natural variation. The proposed techniques are particularly useful in checking the functional form of a covariate and the link function. Illustrations with several medical studies are provided.
Exponential sums over primes in short intervals
Institute of Scientific and Technical Information of China (English)
LIU; Jianya
2006-01-01
[1]Vinogradov,I.M.,Estimation of certain trigonometric sums with prime variables,Izv.Acad.Nauk.SSSR,1939,3:371-398.[2]Zhan,T.,On the representation of large odd integer as a sum of three almost equal primes,Acta Math.Sin.,1991,7:259-272.[3]Ren,X.M.,On exponential sums over primes and application in the Waring-Goldbach problem,Sci.China,Ser.A-Math.,2005,48(6):785-797.[4]Liu,J.Y.,Wooley,T.D.,Yu,G.,The quadratic Waring-Goldbach problem,J.Number Theory,2004,107:298-321.[5]Hua,L.K.,Some results in the additive prime number theory,Quart.J.Math.(Oxford),1938,9:68-80.[6]Liu,J.Y.,Zhan,T.,On sums of five almost equal prime squares,Acta Arith.,1996,77:369-383.[7]Bauer,C.,A note on sums of five almost equal prime squares,Arch.Math,1997,69:20-30.[8]Liu,J.Y.,Zhan,T.,Sums of five almost equal prime squares,Science in China,Ser.A,1998,41:710-722.[9]Liu,J.Y.,Zhan,T.,Hua's theorem on prime squares in short intervals,Acta Math.Sin.,2000,16:1-22.[10]Bauer,C.,Sums of five almost equal prime squares,Acta Math.Sin.,2005,21(4):833-840.[11]Lü,G.S.,Hua's Theorem with five almost equal prime variables,Chin.Ann.Math.,Ser.B,2005,26(2):291-304.[12]Vinogradov,I.M.,Elements of Number Theory,Dover Publications,1954.[13]Titchmarsh,E.C.,The Theory of the Riemann Zeta-function,2nd ed.,Oxford:Oxford University Press,1986.
Generalized Weinberg Sum Rules in Deconstructed QCD
Sekhar-Chivukula, R; Tanabashi, Masaharu; Kurachi, Masafumi; Tanabashi, Masaharu
2004-01-01
Recently, Son and Stephanov have considered an "open moose" as a possible dual model of a QCD-like theory of chiral symmetry breaking. In this note we demonstrate that although the Weinberg sum rules are satisfied in any such model, the relevant sums converge very slowly and in a manner unlike QCD. Further, we show that such a model satisfies a set of generalized sum rules. These sum rules can be understood by looking at the operator product expansion for the correlation function of chiral currents, and correspond to the absence of low-dimension gauge-invariant chiral symmetry breaking condensates. These results imply that, regardless of the couplings and F-constants chosen, the open moose is not the dual of any QCD-like theory of chiral symmetry breaking. We also show that the generalized sum rules lead to a compact expression for the difference of vector- and axial-current correlation functions. This expression allows for a simple formula for the S parameter (L_10), which implies that S is always positive a...
Randomly Stopped Sums: Models and Psychological Applications
Directory of Open Access Journals (Sweden)
Michael eSmithson
2014-11-01
Full Text Available This paper describes an approach to modeling the sums of a continuous random variable over a number of measurement occasions when the number of occasions also is a random variable. A typical example is summing the amounts of time spent attending to pieces of information in an information search task leading to a decision to obtain the total time taken to decide. Although there is a large literature on randomly stopped sums in financial statistics, it is largely absent from psychology. The paper begins with the standard modeling approaches used in financial statistics, and then extends them in two ways. First, the randomly stopped sums are modeled as ``life distributions'' such as the gamma or log-normal distribution. A simulation study investigates Type I error rate accuracy and power for gamma and log-normal versions of this model. Second, a Bayesian hierarchical approach is used for constructing an appropriate general linear model of the sums. Model diagnostics are discussed, and three illustrations are presented from real datasets.
Systematics of strength function sum rules
Johnson, Calvin W.
2015-11-01
Sum rules provide useful insights into transition strength functions and are often expressed as expectation values of an operator. In this letter I demonstrate that non-energy-weighted transition sum rules have strong secular dependences on the energy of the initial state. Such non-trivial systematics have consequences: the simplification suggested by the generalized Brink-Axel hypothesis, for example, does not hold for most cases, though it weakly holds in at least some cases for electric dipole transitions. Furthermore, I show the systematics can be understood through spectral distribution theory, calculated via traces of operators and of products of operators. Seen through this lens, violation of the generalized Brink-Axel hypothesis is unsurprising: one expects sum rules to evolve with excitation energy. Furthermore, to lowest order the slope of the secular evolution can be traced to a component of the Hamiltonian being positive (repulsive) or negative (attractive).
Systematics of strength function sum rules
Energy Technology Data Exchange (ETDEWEB)
Johnson, Calvin W., E-mail: cjohnson@mail.sdsu.edu
2015-11-12
Sum rules provide useful insights into transition strength functions and are often expressed as expectation values of an operator. In this letter I demonstrate that non-energy-weighted transition sum rules have strong secular dependences on the energy of the initial state. Such non-trivial systematics have consequences: the simplification suggested by the generalized Brink–Axel hypothesis, for example, does not hold for most cases, though it weakly holds in at least some cases for electric dipole transitions. Furthermore, I show the systematics can be understood through spectral distribution theory, calculated via traces of operators and of products of operators. Seen through this lens, violation of the generalized Brink–Axel hypothesis is unsurprising: one expects sum rules to evolve with excitation energy. Furthermore, to lowest order the slope of the secular evolution can be traced to a component of the Hamiltonian being positive (repulsive) or negative (attractive).
Finite Temperature QCD Sum Rules: A Review
Directory of Open Access Journals (Sweden)
Alejandro Ayala
2017-01-01
Full Text Available The method of QCD sum rules at finite temperature is reviewed, with emphasis on recent results. These include predictions for the survival of charmonium and bottonium states, at and beyond the critical temperature for deconfinement, as later confirmed by lattice QCD simulations. Also included are determinations in the light-quark vector and axial-vector channels, allowing analysing the Weinberg sum rules and predicting the dimuon spectrum in heavy-ion collisions in the region of the rho-meson. Also, in this sector, the determination of the temperature behaviour of the up-down quark mass, together with the pion decay constant, will be described. Finally, an extension of the QCD sum rule method to incorporate finite baryon chemical potential is reviewed.
Dowker, J S
2015-01-01
The finite sums of powers of cosecs occur in numerous situations, both physical and mathematical, examples being the Casimir effect, Renyi entropy, Verlinde's formula and Dedekind sums. I here present some further discussion which consists mainly of a reprise of early work by H.M.Jeffery in 1862-64 which has fallen by the wayside and whose results are being reproduced up to the present day. The motivation is partly historical justice and partly that, because of the continuing appearance of the sums, his particular methods deserve re--exposure. For example, simple trigonometric generating functions are found and these have a field theoretic, Green function significance and I make a few comments in the topic of R\\'enyi entropies.
Fundamentals of sum-frequency spectroscopy
Shen, Y R
2016-01-01
The first book on the topic, and written by the founder of the technique, this comprehensive resource provides a detailed overview of sum-frequency spectroscopy, its fundamental principles, and the wide range of applications for surfaces, interfaces, and bulk. Beginning with an overview of the historical context, and introductions to the basic theory of nonlinear optics and surface sum-frequency generation, topics covered include discussion of different experimental arrangements adopted by researchers, notes on proper data analysis, an up-to-date survey commenting on the wide range of successful applications of the tool, and a valuable insight into current unsolved problems and potential areas to be explored in the future. With the addition of chapter appendices that offer the opportunity for more in-depth theoretical discussion, this is an essential resource that integrates all aspects of the subject and is ideal for anyone using, or interested in using, sum-frequency spectroscopy.
Systematics of strength function sum rules
Directory of Open Access Journals (Sweden)
Calvin W. Johnson
2015-11-01
Full Text Available Sum rules provide useful insights into transition strength functions and are often expressed as expectation values of an operator. In this letter I demonstrate that non-energy-weighted transition sum rules have strong secular dependences on the energy of the initial state. Such non-trivial systematics have consequences: the simplification suggested by the generalized Brink–Axel hypothesis, for example, does not hold for most cases, though it weakly holds in at least some cases for electric dipole transitions. Furthermore, I show the systematics can be understood through spectral distribution theory, calculated via traces of operators and of products of operators. Seen through this lens, violation of the generalized Brink–Axel hypothesis is unsurprising: one expects sum rules to evolve with excitation energy. Furthermore, to lowest order the slope of the secular evolution can be traced to a component of the Hamiltonian being positive (repulsive or negative (attractive.
Concentration inequalities for sums and martingales
Bercu, Bernard; Rio, Emmanuel
2015-01-01
The purpose of this book is to provide an overview of historical and recent results on concentration inequalities for sums of independent random variables and for martingales. The first chapter is devoted to classical asymptotic results in probability such as the strong law of large numbers and the central limit theorem. Our goal is to show that it is really interesting to make use of concentration inequalities for sums and martingales. The second chapter deals with classical concentration inequalities for sums of independent random variables such as the famous Hoeffding, Bennett, Bernstein and Talagrand inequalities. Further results and improvements are also provided such as the missing factors in those inequalities. The third chapter concerns concentration inequalities for martingales such as Azuma-Hoeffding, Freedman and De la Pena inequalities. Several extensions are also provided. The fourth chapter is devoted to applications of concentration inequalities in probability and statistics.
Least square regularized regression in sum space.
Xu, Yong-Li; Chen, Di-Rong; Li, Han-Xiong; Liu, Lu
2013-04-01
This paper proposes a least square regularized regression algorithm in sum space of reproducing kernel Hilbert spaces (RKHSs) for nonflat function approximation, and obtains the solution of the algorithm by solving a system of linear equations. This algorithm can approximate the low- and high-frequency component of the target function with large and small scale kernels, respectively. The convergence and learning rate are analyzed. We measure the complexity of the sum space by its covering number and demonstrate that the covering number can be bounded by the product of the covering numbers of basic RKHSs. For sum space of RKHSs with Gaussian kernels, by choosing appropriate parameters, we tradeoff the sample error and regularization error, and obtain a polynomial learning rate, which is better than that in any single RKHS. The utility of this method is illustrated with two simulated data sets and five real-life databases.
Sum rule of the correlation function
Maj, R; Maj, Radoslaw; Mrowczynski, Stanislaw
2004-01-01
We discuss a sum rule satisfied by the correlation function of two particles with small relative momenta. The sum rule, which results from the completeness condition of the quantum states of the two particles, is first derived and then we check how it works in practice. The sum rule is shown to be trivially satisfied by free particle pair, and then there are considered three different systems of interacting particles. We discuss a pair of neutron and proton in the s-wave approximation and the case of the so-called hard spheres with the phase shifts taken into account up to l=4. Finally, the Coulomb system of two charged particles is analyzed.
Irreducible polynomials with prescribed sums of coefficients
Tuxanidy, Aleksandr; Wang, Qiang
2016-01-01
Let $q$ be a power of a prime, let $\\mathbb{F}_q$ be the finite field with $q$ elements and let $n \\geq 2$. For a polynomial $h(x) \\in \\mathbb{F}_q[x]$ of degree $n \\in \\mathbb{N}$ and a subset $W \\subseteq [0,n] := \\{0, 1, \\ldots, n\\}$, we define the sum-of-digits function $$S_W(h) = \\sum_{w \\in W}[x^{w}] h(x)$$ to be the sum of all the coefficients of $x^w$ in $h(x)$ with $w \\in W$. In the case when $q = 2$, we prove, except for a few genuine exceptions, that for any $c \\in \\mathbb{F}_2$ an...
Nonlinear cumulative damage model for multiaxial fatigue
Institute of Scientific and Technical Information of China (English)
SHANG De-guang; SUN Guo-qin; DENG Jing; YAN Chu-liang
2006-01-01
On the basis of the continuum fatigue damage theory,a nonlinear uniaxial fatigue cumulative damage model is first proposed.In order to describe multiaxial fatigue damage characteristics,a nonlinear multiaxial fatigue cumulative damage model is developed based on the critical plane approach,The proposed model can consider the multiaxial fatigue limit,mean hydrostatic pressure and the unseparated characteristic for the damage variables and loading parameters.The recurrence formula of fatigue damage model was derived under multilevel loading,which is used to predict multiaxial fatigue life.The results showed that the proposed nonlinear multiaxial fatigue cumulative damage model is better than Miner's rule.
Integrals of Lagrange functions and sum rules
Energy Technology Data Exchange (ETDEWEB)
Baye, Daniel, E-mail: dbaye@ulb.ac.be [Physique Quantique, CP 165/82, Universite Libre de Bruxelles, B 1050 Bruxelles (Belgium); Physique Nucleaire Theorique et Physique Mathematique, CP 229, Universite Libre de Bruxelles, B 1050 Bruxelles (Belgium)
2011-09-30
Exact values are derived for some matrix elements of Lagrange functions, i.e. orthonormal cardinal functions, constructed from orthogonal polynomials. They are obtained with exact Gauss quadratures supplemented by corrections. In the particular case of Lagrange-Laguerre and shifted Lagrange-Jacobi functions, sum rules provide exact values for matrix elements of 1/x and 1/x{sup 2} as well as for the kinetic energy. From these expressions, new sum rules involving Laguerre and shifted Jacobi zeros and weights are derived. (paper)
Almost Sure Central Limit Theory for Self-Normalized Products of Sums of Partial Sums
Directory of Open Access Journals (Sweden)
Qunying Wu
2012-01-01
Full Text Available Let X,X1,X2,… be a sequence of independent and identically distributed random variables in the domain of attraction of a normal law. An almost sure limit theorem for the self-normalized products of sums of partial sums is established.
Cumulative cultural learning: Development and diversity.
Legare, Cristine H
2017-07-24
The complexity and variability of human culture is unmatched by any other species. Humans live in culturally constructed niches filled with artifacts, skills, beliefs, and practices that have been inherited, accumulated, and modified over generations. A causal account of the complexity of human culture must explain its distinguishing characteristics: It is cumulative and highly variable within and across populations. I propose that the psychological adaptations supporting cumulative cultural transmission are universal but are sufficiently flexible to support the acquisition of highly variable behavioral repertoires. This paper describes variation in the transmission practices (teaching) and acquisition strategies (imitation) that support cumulative cultural learning in childhood. Examining flexibility and variation in caregiver socialization and children's learning extends our understanding of evolution in living systems by providing insight into the psychological foundations of cumulative cultural transmission-the cornerstone of human cultural diversity.
Wen, Zhe; Liang, Huiying; Liang, Jiankun; Liang, Qifeng; Xia, Huimin
2017-02-01
Laparoscopic cyst excision and Roux-en-Y hepaticojejunostomy is gaining popularity as a treatment for choledochal cyst (CDC) in children. However, the learning curve for this challenging laparoscopic procedure has not been addressed. The aim of this study is to determine the characteristics of the learning curve of this procedure. This may guide the training in institutions currently not using this technique. A prospectively collected database comprising all medical records of the first 104 consecutive patients undergoing laparoscopic CDC excision and Roux-en-Y hepaticojejunostomy performed by one surgeon was studied. Multifactorial linear/logistic regression analysis was performed to identify patient-, surgeon-, and procedure-related factors associated with operating times, rates of adverse event, and length of postoperative stay. Cumulative sum analysis demonstrated a learning curve for laparoscopic choledochal cyst excision of 37 cases. Comparing the early with the late experiences (37 vs. 67 cases), the surgeon-specific outcomes significantly improved in terms of operating times (352 vs. 240 min; P learning curve (CLC) (OR 0.68, 95 % CI 0.63-0.73) and adhesion score (ORmiddle 1.25, 95 % CI 1.08-1.45; ORhigh 1.40, 95 % CI 1.20-1.62; compared with the low score); significant predictors of perioperative adverse outcomes were CLC (OR 0.07, 95 % CI 0.02-0.34) and comorbidities prior to the surgery (OR 30.65, 95 % CI 1.71-549.63). The independent predictors of length of postoperative stay included CLC, preoperative comorbidities, and perioperative adverse events. CLC for laparoscopic choledochal cyst excision is 37 cases. After CLC, not only the operative time is reduced, the complications, adverse results, and the length of hospital stay all decreased significantly. The learning curve can be used as the basis for performance guiding the training.
Calculating Cumulative Binomial-Distribution Probabilities
Scheuer, Ernest M.; Bowerman, Paul N.
1989-01-01
Cumulative-binomial computer program, CUMBIN, one of set of three programs, calculates cumulative binomial probability distributions for arbitrary inputs. CUMBIN, NEWTONP (NPO-17556), and CROSSER (NPO-17557), used independently of one another. Reliabilities and availabilities of k-out-of-n systems analyzed. Used by statisticians and users of statistical procedures, test planners, designers, and numerical analysts. Used for calculations of reliability and availability. Program written in C.
Cumulative cultural evolution: the role of teaching.
Castro, Laureano; Toro, Miguel A
2014-04-21
In humans, cultural transmission occurs usually by cumulative inheritance, generating complex adaptive behavioral features. Cumulative culture requires key psychological processes (fundamentally imitation and teaching) that are absent or impoverished in non-human primates. In this paper we analyze the role that teaching has played in human cumulative cultural evolution. We assume that a system of cumulative culture generates increasingly adaptive behaviors, that are also more complex and difficult to imitate. Our thesis is that, as cultural traits become more complex, cumulative cultural transmission requires teaching to ensure accurate transmission from one generation to the next. In an increasingly complex cultural environment, we consider that individuals commit errors in imitation. We develop a model of cumulative cultural evolution in a changing environment and show that these errors hamper the process of cultural accumulation. We also show that a system of teaching between parents and offspring that increases the fidelity of imitation unblocks the accumulation and becomes adaptive whenever the gain in fitness compensates the cost of teaching.
Human cumulative culture: a comparative perspective.
Dean, Lewis G; Vale, Gill L; Laland, Kevin N; Flynn, Emma; Kendal, Rachel L
2014-05-01
Many animals exhibit social learning and behavioural traditions, but human culture exhibits unparalleled complexity and diversity, and is unambiguously cumulative in character. These similarities and differences have spawned a debate over whether animal traditions and human culture are reliant on homologous or analogous psychological processes. Human cumulative culture combines high-fidelity transmission of cultural knowledge with beneficial modifications to generate a 'ratcheting' in technological complexity, leading to the development of traits far more complex than one individual could invent alone. Claims have been made for cumulative culture in several species of animals, including chimpanzees, orangutans and New Caledonian crows, but these remain contentious. Whilst initial work on the topic of cumulative culture was largely theoretical, employing mathematical methods developed by population biologists, in recent years researchers from a wide range of disciplines, including psychology, biology, economics, biological anthropology, linguistics and archaeology, have turned their attention to the experimental investigation of cumulative culture. We review this literature, highlighting advances made in understanding the underlying processes of cumulative culture and emphasising areas of agreement and disagreement amongst investigators in separate fields.
Summing threshold logs in a parton shower
Nagy, Zoltan
2016-01-01
When parton distributions are falling steeply as the momentum fractions of the partons increases, there are effects that occur at each order in $\\alpha_s$ that combine to affect hard scattering cross sections and need to be summed. We show how to accomplish this in a leading approximation in the context of a parton shower Monte Carlo event generator.
Form Sums of Nonnegative Selfadjoint Operators
Hassi, S.; Sandovici, A.; Snoo, H.S.V. de; Winkler, Henrik; Sandovici, 27740
2006-01-01
The sum of two unbounded nonnegative selfadjoint operators is a nonnegative operator which is not necessarily densely defined. In general its selfadjoint extensions exist in the sense of linear relations (multivalued operators). One of its nonnegative selfadjoint extensions is constructed via the fo
The Ronkin number of an exponential sum
Silipo, James
2011-01-01
We give an intrinsic estimate of the number of connected components of the complementary set to the amoeba of an exponential sum with real spectrum improving the result of Forsberg, Passare and Tsikh in the polynomial case and that of Ronkin in the exponential one.
Summing threshold logs in a parton shower
Energy Technology Data Exchange (ETDEWEB)
Nagy, Zoltan [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Soper, Davison E. [Oregon Univ., Eugene, OR (United States). Inst. of Theoretical Science
2016-05-15
When parton distributions are falling steeply as the momentum fractions of the partons increases, there are effects that occur at each order in α{sub s} that combine to affect hard scattering cross sections and need to be summed. We show how to accomplish this in a leading approximation in the context of a parton shower Monte Carlo event generator.
Sum and product in dynamic epistemic logic
Van Ditmarsch, H. P.; Ruan, J.; Verbrugge, R.
2008-01-01
The Sum-and-Product riddle was first published in the reference H. Freudenthal (1969, Nieuw Archief voor Wiskunde 3, 152) [6]. We provide an overview on the history of the dissemination of this riddle through the academic and puzzle-math community. This includes some references to precursors of the
On the Computation of Correctly Rounded Sums
DEFF Research Database (Denmark)
Kornerup, Peter; Lefevre, Vincent; Louvet, Nicolas;
2012-01-01
algorithm introduced by Knuth is minimal, both in terms of number of operations and depth of the dependency graph. We investigate the possible use of another algorithm, Dekker's Fast2Sum algorithm, in radix-10 arithmetic. We give methods for computing, in radix 10, the floating-point number nearest...
Sums of Integer Squares: A New Look.
Sastry, K. R. S.; Pranesachar, C. R.; Venkatachala, B. J.
1998-01-01
Focuses on the study of the sum of two integer squares, neither of which is zero square. Develops some new interesting and nonstandard ideas that can be put to use in number theory class, mathematics club meetings, or popular lectures. (ASK)
Fibonacci Identities via the Determinant Sum Property
Spivey, Michael
2006-01-01
We use the sum property for determinants of matrices to give a three-stage proof of an identity involving Fibonacci numbers. Cassini's and d'Ocagne's Fibonacci identities are obtained at the ends of stages one and two, respectively. Catalan's Fibonacci identity is also a special case.
Demonstration of a Quantum Nondemolition Sum Gate
DEFF Research Database (Denmark)
Yoshikawa, J.; Miwa, Y.; Huck, Alexander;
2008-01-01
The sum gate is the canonical two-mode gate for universal quantum computation based on continuous quantum variables. It represents the natural analogue to a qubit C-NOT gate. In addition, the continuous-variable gate describes a quantum nondemolition (QND) interaction between the quadrature compo...
Large- quantum chromodynamics and harmonic sums
Indian Academy of Sciences (India)
Eduardo De Rafael
2012-06-01
In the large- limit of QCD, two-point functions of local operators become harmonic sums. I review some properties which follow from this fact and which are relevant for phenomenological applications. This has led us to consider a class of analytic number theory functions as toy models of large- QCD which also is discussed.
Zero-Sum Problems with Subgroup Weights
Indian Academy of Sciences (India)
S D Adhikari; A A Ambily; B Sury
2010-06-01
In this note, we generalize some theorems on zero-sums with weights from [1], [4] and [5] in two directions. In particular, we consider $\\mathbb{Z}^d_p$ for a general and subgroups of $Z^∗_p$ as weights.
On the sum of generalized Fibonacci sequence
Chong, Chin-Yoon; Ho, C. K.
2014-06-01
We consider the generalized Fibonacci sequence {Un defined by U0 = 0, U1 = 1, and Un+2 = pUn+1+qUn for all n∈Z0+ and p, q∈Z+. In this paper, we derived various sums of the generalized Fibonacci sequence from their recursive relations.
On Learning Ring-Sum-Expansions
DEFF Research Database (Denmark)
Fischer, Paul; Simon, H. -U.
1992-01-01
The problem of learning ring-sum-expansions from examples is studied. Ring-sum-expansions (RSE) are representations of Boolean functions over the base {#123;small infinum, (+), 1}#125;, which reflect arithmetic operations in GF(2). k-RSE is the class of ring-sum-expansions containing only monomials...... of length at most k:. term-RSE is the class of ring-sum-expansions having at most I: monomials. It is shown that k-RSE, k>or=1, is learnable while k-term-RSE, k>2, is not learnable if RPnot=NP. Without using a complexity-theoretical hypothesis, it is proven that k-RSE, k>or=1, and k-term-RSE, k>or=2 cannot...... be learned from positive (negative) examples alone. However, if the restriction that the hypothesis which is output by the learning algorithm is also a k-RSE is suspended, then k-RSE is learnable from positive (negative) examples only. Moreover, it is proved that 2-term-RSE is learnable by a conjunction...
The Distribution of Sum of Random Sums%随机和的和的分布
Institute of Scientific and Technical Information of China (English)
王开永; 戚文文
2012-01-01
对于两个独立的随机和，利用概率论的方法讨论它们的和的分布问题，可以得出独立的随机和的和仍然为随机和的结论．另外具体给出复合Poisson分布和、复合二项分布和、复合负二项分布和，以及复合几何分布和的分布．’%For two independent random sums, the distribution of the sum of these two random sums is investigated and a general result that the sum of two independent random sums is still a random sum is presented, which shows the relation between the two distributions. Using this result, the distributions of the sums of some common compound distributions are given which include the compound Poisson distribution, binomial distribution, generalized binomial distribution, and geometric distribution.
A Single Disease Cost Variance Analysis Model Based on CUSUM and SVM%基于CUSUM控制图和SVM的单病种成本差异分析
Institute of Scientific and Technical Information of China (English)
刘子先; 邹刘霞; 徐靖
2012-01-01
CUSUM控制图可用来监测均值的偏移.在单病种成本值发生重大差异前,短期内会发生一定失控趋势,CUSUM控制图却不能及时发出失控信号.针对成本差异分析中存在的问题,提出了基于支持向量机(SVM)的智能化单病种成本差异分析模型来替代CUSUM控制图.首先利用支持向量机(SVM)自身良好的泛化能力经过训练后获得复杂成本值之间的内在规律,然后对测试样本进行有效的预测分类,及时给出失控的样本点.将模型应用到单纯性阑尾炎病人样本中,与CUSUM控制图方法作比较,结果显示了该模型比CUSUM控制图更加及时发现有失控趋势或失控的样本点.%CUSUM control chart can be used to detect the shifts in the mean. Before the significant cost variance of single disease,the cost will have certain out-control trend in the short term,but the CUSUM control chart couldn't timely forecast. In view of the problems existing in the cost difference analysis,this paper put forward an intelligent method based on support vector machine (SVM) of single disease cost variance analysis model as an alternative approach to CUSUM control chart. Support vector machine (SVM) used its good generalization ability after training to obtain the internal rules from complex cost data, then the test sample points for effective prediction classification and timely forecast points of out-control. The model was applied to the simple appendicitis surgery, by comparing the method with the CUSUM control chart model,the results suggest this model is more sensitive than CUSUM control chart.
A New Generalization of Hardy-Berndt Sums
Indian Academy of Sciences (India)
Muhammet Cihat Dağli; Mümün Can
2013-05-01
In this paper, we construct a new generalization of Hardy–Berndt sums which are explicit extensions of Hardy–Berndt sums. We express these sums in terms of Dedekind sums $s_r(h,k:x,y|)$ with ==0 and obtain corresponding reciprocity formulas.
Predicting Cumulative Incidence Probability by Direct Binomial Regression
DEFF Research Database (Denmark)
Scheike, Thomas H.; Zhang, Mei-Jie
Binomial modelling; cumulative incidence probability; cause-specific hazards; subdistribution hazard......Binomial modelling; cumulative incidence probability; cause-specific hazards; subdistribution hazard...
New QCD sum rules based on canonical commutation relations
Hayata, Tomoya
2012-04-01
New derivation of QCD sum rules by canonical commutators is developed. It is the simple and straightforward generalization of Thomas-Reiche-Kuhn sum rule on the basis of Kugo-Ojima operator formalism of a non-abelian gauge theory and a suitable subtraction of UV divergences. By applying the method to the vector and axial vector current in QCD, the exact Weinberg’s sum rules are examined. Vector current sum rules and new fractional power sum rules are also discussed.
Strong sum distance in fuzzy graphs.
Tom, Mini; Sunitha, Muraleedharan Shetty
2015-01-01
In this paper the idea of strong sum distance which is a metric, in a fuzzy graph is introduced. Based on this metric the concepts of eccentricity, radius, diameter, center and self centered fuzzy graphs are studied. Some properties of eccentric nodes, peripheral nodes and central nodes are obtained. A characterisation of self centered complete fuzzy graph is obtained and conditions under which a fuzzy cycle is self centered are established. We have proved that based on this metric, an eccentric node of a fuzzy tree G is a fuzzy end node of G and a node is an eccentric node of a fuzzy tree if and only if it is a peripheral node of G and the center of a fuzzy tree consists of either one or two neighboring nodes. The concepts of boundary nodes and interior nodes in a fuzzy graph based on strong sum distance are introduced. Some properties of boundary nodes, interior nodes and complete nodes are studied.
Transition Mean Values of Shifted Convolution Sums
Petrow, Ian
2011-01-01
Let f be a classical holomorphic cusp form for SL_2(Z) of weight k which is a normalized eigenfunction for the Hecke algebra, and let \\lambda(n) be its eigenvalues. In this paper we study "shifted convolution sums" of the eigenvalues \\lambda(n) after averaging over many shifts h and obtain asymptotic estimates. The result is somewhat surprising: one encounters a transition region depending on the ratio of the square of the length of the average over h to the length of the shifted convolution sum. The phenomenon is similar to that encountered by Conrey, Farmer and Soundararajan in their 2000 paper Transition Mean Values of Real Characters, and the connection of both results to Eisenstein series and multiple Dirichlet series is discussed.
Maximum Segment Sum, Monadically (distilled tutorial
Directory of Open Access Journals (Sweden)
Jeremy Gibbons
2011-09-01
Full Text Available The maximum segment sum problem is to compute, given a list of integers, the largest of the sums of the contiguous segments of that list. This problem specification maps directly onto a cubic-time algorithm; however, there is a very elegant linear-time solution too. The problem is a classic exercise in the mathematics of program construction, illustrating important principles such as calculational development, pointfree reasoning, algebraic structure, and datatype-genericity. Here, we take a sideways look at the datatype-generic version of the problem in terms of monadic functional programming, instead of the traditional relational approach; the presentation is tutorial in style, and leavened with exercises for the reader.
Optical Thomas-Reiche-Kuhn Sum Rules
Barnett, Stephen M.; Loudon, Rodney
2012-01-01
The Thomas-Reiche-Kuhn sum rule is a fundamental consequence of the position-momentum commutation relation for an atomic electron and it provides an important constraint on the transition matrix elements for an atom. Analogously, the commutation relations for the electromagnetic field operators in a magnetodielectric medium constrain the properties of the dispersion relations for the medium through four sum rules for the allowed phase and group velocities for polaritons propagating through the medium. These rules apply to all bulk media including the metamaterials designed to provide negative refractive indices. An immediate consequence of this is that it is not possible to construct a medium in which all the polariton modes for a given wavelength lie in the negative-index region.
Geometric optimization and sums of algebraic functions
Vigneron, Antoine E.
2014-01-01
We present a new optimization technique that yields the first FPTAS for several geometric problems. These problems reduce to optimizing a sum of nonnegative, constant description complexity algebraic functions. We first give an FPTAS for optimizing such a sum of algebraic functions, and then we apply it to several geometric optimization problems. We obtain the first FPTAS for two fundamental geometric shape-matching problems in fixed dimension: maximizing the volume of overlap of two polyhedra under rigid motions and minimizing their symmetric difference. We obtain the first FPTAS for other problems in fixed dimension, such as computing an optimal ray in a weighted subdivision, finding the largest axially symmetric subset of a polyhedron, and computing minimum-area hulls.
Disjoint sum forms in reliability theory
Directory of Open Access Journals (Sweden)
B. Anrig
2014-01-01
Full Text Available The structure function f of a binary monotone system is assumed to be known and given in a disjunctive normal form, i.e. as the logical union of products of the indicator variables of the states of its subsystems. Based on this representation of f, an improved Abraham algorithm is proposed for generating the disjoint sum form of f. This form is the base for subsequent numerical reliability calculations. The approach is generalized to multivalued systems. Examples are discussed.
Advances in QCD sum rule calculations
Melikhov, Dmitri
2016-01-01
We review the recent progress in the applications of QCD sum rules to hadron properties with the emphasis on the following selected problems: (i) development of new algorithms for the extraction of ground-state parameters from two-point correlators; (ii) form factors at large momentum transfers from three-point vacuum correlation functions; (iii) properties of exotic tetraquark hadrons from correlation functions of four-quark currents.
Advances in QCD sum-rule calculations
Energy Technology Data Exchange (ETDEWEB)
Melikhov, Dmitri [Institute for High Energy Physics, Austrian Academy of Sciences, Nikolsdorfergasse 18, A-1050 Vienna, Austria D. V. Skobeltsyn Institute of Nuclear Physics, M. V. Lomonosov Moscow State University, Moscow (Russian Federation)
2016-01-22
We review the recent progress in the applications of QCD sum rules to hadron properties with the emphasis on the following selected problems: (i) development of new algorithms for the extraction of ground-state parameters from two-point correlators; (ii) form factors at large momentum transfers from three-point vacuum correlation functions: (iii) properties of exotic tetraquark hadrons from correlation functions of four-quark currents.
Variance of partial sums of stationary sequences
Deligiannidis, George
2012-01-01
Let $X_1, X_2,...$ be a centred sequence of weakly stationary random variables with spectral measure $F$ and partial sums $S_n = X_1 +...+ X_n$, and let $G(x) = \\int_{-x}^x F(\\rd x)$. We show that $\\var(S_n)$ is regularly varying of index $\\gamma$ at infinity, if and only if $G(x)$ is regularly varying of index $2-\\gamma$ at the origin ($0<\\gamma<2$).
Heavy Baryons and QCD Sum Rules
Yakovlev, O I
1996-01-01
We discuss an application of QCD sum rules to the heavy baryons $\\Lambda_Q$ and $\\Sigma_Q$. The predictions for the masses of heavy baryons, residues and Isgur-Wise function are presented. The new results on two loop anomalous dimensions of baryonic currents and QCD radiative corrections (two- and three- loop contributions) to the first two Wilson coefficients in OPE are explicitly presented.
Sequences, Bent Functions and Jacobsthal sums
Helleseth, Tor
2010-01-01
The $p$-ary function $f(x)$ mapping $\\mathrm{GF}(p^{4k})$ to $\\mathrm{GF}(p)$ and given by $f(x)={\\rm Tr}_{4k}\\big(ax^d+bx^2\\big)$ with $a,b\\in\\mathrm{GF}(p^{4k})$ and $d=p^{3k}+p^{2k}-p^k+1$ is studied with the respect to its exponential sum. In the case when either $a^{p^k(p^k+1)}\
Gao's Conjecture on Zero-Sum Sequences
Indian Academy of Sciences (India)
B Sury; R Thangadurai
2002-08-01
In this paper, we shall address three closely-related conjectures due to van Emde Boas, W D Gao and Kemnitz on zero-sum problems on $\\mathbf{Z}_p \\oplus \\mathbf{Z}_p$. We prove a number of results including a proof of the conjecture of Gao for the prime = 7 (Theorem 3.1). The conjecture of Kemnitz is also proved (Propositions 4.6, 4.9, 4.10) for many classes of sequences.
A 2-categorical state sum model
Baratin, Aristide; Freidel, Laurent
2015-01-01
It has long been argued that higher categories provide the proper algebraic structure underlying state sum invariants of 4-manifolds. This idea has been refined recently, by proposing to use 2-groups and their representations as specific examples of 2-categories. The challenge has been to make these proposals fully explicit. Here, we give a concrete realization of this program. Building upon our earlier work with Baez and Wise on the representation theory of 2-groups, we construct a four-dimensional state sum model based on a categorified version of the Euclidean group. We define and explicitly compute the simplex weights, which may be viewed a categorified analogue of Racah-Wigner 6j-symbols. These weights solve a hexagon equation that encodes the formal invariance of the state sum under the Pachner moves of the triangulation. This result unravels the combinatorial formulation of the Feynman amplitudes of quantum field theory on flat spacetime proposed in A. Baratin and L. Freidel [Classical Quantum Gravity 24, 2027-2060 (2007)] which was shown to lead after gauge-fixing to Korepanov's invariant of 4-manifolds.
A 2-categorical state sum model
Baratin, Aristide
2014-01-01
It has long been argued that higher categories provide the proper algebraic structure underlying state sum invariants of 4-manifolds. This idea has been refined recently, by proposing to use 2-groups and their representations as specific examples of 2-categories. The challenge has been to make these proposals fully explicit. Here we give a concrete realization of this program. Building upon our earlier work with Baez and Wise on the representation theory of 2-groups, we construct a four-dimensional state sum model based on a categorified version of the Euclidean group. We define and explicitly compute the simplex weights, which may be viewed a categorified analogue of Racah-Wigner 6$j$-symbols. These weights solve an hexagon equation that encodes the formal invariance of the state sum under the Pachner moves of the triangulation. This result unravels the combinatorial formulation of the Feynman amplitudes of quantum field theory on flat spacetime proposed in [1], which was shown to lead after gauge-fixing to ...
A 2-categorical state sum model
Energy Technology Data Exchange (ETDEWEB)
Baratin, Aristide, E-mail: abaratin@uwaterloo.ca [Department of Applied Mathematics, University of Waterloo, 200 University Ave W, Waterloo, Ontario N2L 3G1 (Canada); Freidel, Laurent, E-mail: lfreidel@perimeterinstitute.ca [Perimeter Institute for Theoretical Physics, 31 Caroline Str. N, Waterloo, Ontario N2L 2Y5 (Canada)
2015-01-15
It has long been argued that higher categories provide the proper algebraic structure underlying state sum invariants of 4-manifolds. This idea has been refined recently, by proposing to use 2-groups and their representations as specific examples of 2-categories. The challenge has been to make these proposals fully explicit. Here, we give a concrete realization of this program. Building upon our earlier work with Baez and Wise on the representation theory of 2-groups, we construct a four-dimensional state sum model based on a categorified version of the Euclidean group. We define and explicitly compute the simplex weights, which may be viewed a categorified analogue of Racah-Wigner 6j-symbols. These weights solve a hexagon equation that encodes the formal invariance of the state sum under the Pachner moves of the triangulation. This result unravels the combinatorial formulation of the Feynman amplitudes of quantum field theory on flat spacetime proposed in A. Baratin and L. Freidel [Classical Quantum Gravity 24, 2027–2060 (2007)] which was shown to lead after gauge-fixing to Korepanov’s invariant of 4-manifolds.
Martin Sénéchal; Jana Slaght; Bouchard, Danielle R.
2015-01-01
Objectives. To evaluate if cumulative weight exposure is associated with weight loss strategy choices and weight loss success. Methods. Data from the National Health and Nutrition Examination Survey were used; a total of 4,562 people age 50 years or older who reported trying to lose weight in the last year were studied. Cumulative weight exposure (CWE) score was defined as the sum of body mass index points above 25 kg/m2 at the age of 25, 10 years ago, 1 year ago, and now. Weight loss strateg...
Vale, G. L.; Flynn, E. G.; Kendal, R. L.
2012-01-01
Cumulative culture denotes the, arguably, human capacity to build on the cultural behaviors of one's predecessors, allowing increases in cultural complexity to occur such that many of our cultural artifacts, products and technologies have progressed beyond what a single individual could invent alone. This process of cumulative cultural evolution…
Is cumulated pyrethroid exposure associated with prediabetes?
DEFF Research Database (Denmark)
Hansen, Martin Rune; Jørs, Erik; Lander, Flemming;
2014-01-01
, cumulative exposure) was assessed from questionnaire data. Participants were asked about symptoms of diabetes. Blood samples were analyzed for glycosylated hemoglobin (HbA1c), a measure of glucose regulation. No association was found between pyrethroid exposure and diabetes symptoms. The prevalence...
Cumulative Disadvantage among the Highly Ambitious.
McClelland, Katherine
1990-01-01
Using a social reproduction theory framework, analyzes the process by which high school seniors aspiring to high-level positions are sorted out after graduation. Analyzes early educational attainments and changes in occupational expectations. Shows a process of cumulative disadvantage in which White males are more likely to achieve their goals.…
Pavlovian conditioning and cumulative reinforcement rate.
Harris, Justin A; Patterson, Angela E; Gharaei, Saba
2015-04-01
In 5 experiments using delay conditioning of magazine approach with rats, reinforcement rate was varied either by manipulating the mean interval between onset of the conditioned stimulus (CS) and unconditioned stimulus (US) or by manipulating the proportion of CS presentations that ended with the US (trial-based reinforcement rate). Both manipulations influenced the acquisition of responding. In each experiment, a specific comparison was made between 2 CSs that differed in their mean CS-US interval and in their trial-based reinforcement rate, such that the cumulative reinforcement rate-the cumulative duration of the CS between reinforcements-was the same for the 2 CSs. For example, a CS reinforced on 100% of trials with a mean CS-US interval of 60 s was compared with a CS reinforced on 33% of trials and a mean duration of 20 s. Across the 5 experiments, conditioning was virtually identical for the 2 CSs with matched cumulative reinforcement rate. This was true as long as the timing of the US was unpredictable and, thus, response rates were uniform across the length of the CS. We conclude that the effects of CS-US interval and of trial-based reinforcement rate are reducible entirely to their common effect on cumulative reinforcement rate. We discuss the implications of this for rate-based, trial-based, and real-time associative models of conditioning.
An Axiomatization of Cumulative Prospect Theory
Wakker, P.P.; Tversky, A.
1993-01-01
This paper presents a method for axiomatizing a variety of models for decision making under uncertainty, including Expected Utility and Cumulative Prospect Theory. This method identifies, for each model, the situations that permit consistent inferences about the ordering of value differences. Exampl
Cumulative Disadvantage among the Highly Ambitious.
McClelland, Katherine
1990-01-01
Using a social reproduction theory framework, analyzes the process by which high school seniors aspiring to high-level positions are sorted out after graduation. Analyzes early educational attainments and changes in occupational expectations. Shows a process of cumulative disadvantage in which White males are more likely to achieve their goals.…
An efficiency comparison of control chart for monitoring process variance: Non-normality case
Directory of Open Access Journals (Sweden)
Sangkawanit, R.
2005-11-01
Full Text Available The purposes of this research are to investigate the relation between upper control limit and parameters of weighted moving variance linear weight control chart (WMVL, weighted moving variance: exponential weight control chart (WMVE , successive difference cumulative sum control chart (Cusum-SD and current sample mean cumulative sum control chart (Cusum-UM and to compare efficiencies of these control charts for monitoring increases in process variance, exponentially distributed data with unit variance and Student's t distributed data with variance 1.071429 (30 degrees of freedom as the in control process. Incontrol average run lengths (ARL0 of 200, 400 and 800 are considered. Out-of-control average run lengths (ARL1 obtained via simulation 10,000 times are used as a criteria.The main results are as follows: the upper control limit of WMVL has a negative relation with moving span while the upper control limit of WMVE has a negative relation with moving span and a positive relation with exponential weight. Both the upper control limits of Cusum-SD and Cusum-UM have a negative relation with reference value in which such relation looks like an exponential curve.The results of efficiency comparisons in case of exponentially distributed data for ARL0 of 200, 400 and 800 turned out to be quite similar. When standard deviation changes less than 50%, Cusum-SD control chart and Cusum-UM control chart have ARL1 less than those of WMVL control chart and WMVE control chart. However, when standard deviation changes more than 50%, WMVL control chart and WMVE control chart have ARL1 less than those of Cusum-SD control chart and Cusum-UM control chart. The results are different from the normally distributed data case, studied by Sparks in 2003. In case of Student's t distributed data for ARL0 of 200 and 400 when process variance shifts by a small amount (less than 50%, Cusum- UM control chart has the lowest ARL1 but when process variance shifts by a large amount
Generalizations of some Zero Sum Theorems
Indian Academy of Sciences (India)
M N Chintamani; B K Moriya
2012-02-01
Given an abelian group of order , and a finite non-empty subset of integers, the Davenport constant of with weight , denoted by $D_A(G)$, is defined to be the least positive integer such that, for every sequence $(x_1,\\ldots,x_t)$ with $x_i\\in G$, there exists a non-empty subsequence $(x_{j_1},\\ldots,x_{j_l})$ and $a_i\\in A$ such that $\\sum^l_{i=1}a_ix_{j_i}=0$. Similarly, for an abelian group of order $n,E_A(G)$ is defined to be the least positive integer such that every sequence over of length contains a subsequence $(x_{j_1},\\ldots,x_{j_n})$ such that $\\sum^n_{i=1}a_ix_{j_i}=0$, for some $a_i\\in A$. When is of order , one considers to be a non-empty subset of $\\{1,\\ldots,n-1\\}$. If is the cyclic group $\\mathbb{Z}/n\\mathbb{Z}$, we denote $E_A(G)$ and $D_A(G)$ by $E_A(n)$ and $D_A(n)$ respectively. In this note, we extend some results of Adhikari et al(Integers 8(2008) Article A52) and determine bounds for $D_{R_n}(n)$ and $E_{R_n}(n)$, where $R_n=\\{x^2:x\\in(\\mathbb{Z}/n\\mathbb{Z})^∗\\}$. We follow some lines of argument from Adhikari et al(Integers 8 (2008) Article A52) and use a recent result of Yuan and Zeng (European J. Combinatorics 31 (2010) 677–680), a theorem due to Chowla (Proc. Indian Acad. Sci. (Math. Sci.) 2 (1935) 242–243) and Kneser’s theorem (Math. Z.58(1953) 459–484;66(1956) 88–110;61(1955) 429–434).
Some Zero-Sum Constants with Weights
Indian Academy of Sciences (India)
S D Adhikari; R Balasubramanian; F Pappalardi; P Rath
2008-05-01
For an abelian group , the Davenport constant () is defined to be the smallest natural number such that any sequence of elements in has a non-empty subsequence whose sum is zero (the identity element). Motivated by some recent developments around the notion of Davenport constant with weights, we study them in some basic cases. We also define a new combinatorial invariant related to $(\\mathbb{Z}/n\\mathbb{Z})^d$, more in the spirit of some constants considered by Harborth and others and obtain its exact value in the case of $(\\mathbb{Z}/n\\mathbb{Z})^2$ where is an odd integer.
Exponential sums over primes in short intervals
Institute of Scientific and Technical Information of China (English)
LIU Jianya; L(U) Guangshi; ZHAN Tao
2006-01-01
In this paper we establish one new estimate on exponential sums over primes in short intervals. As an application of this result, we sharpen Hua's result by proving that each sufficiently large integer N congruent to 5 modulo 24 can be written as N = p21 +p22 +p23 +p24 +p25, with |pj - √N/5| ≤ U = N1/2-1/20+ε,where pj are primes. This result is as good as what one can obtain from the generalized Riemann hypothesis.
Clique Cover Width and Clique Sum
Shahrokhi, Farhad
2015-01-01
For a clique cover $C$ in the undirected graph $G$, the clique cover graph of $C$ is the graph obtained by contracting the vertices of each clique in $C$ into a single vertex. The clique cover width of G, denoted by $CCW(G)$, is the minimum value of the bandwidth of all clique cover graphs of $G$. When $G$ is the clique sum of $G_1$ and $G_2$, we prove that $CCW(G) \\le 3/2(CCW(G_1) + CCW(G_2))$.
Sum-of-squares clustering on networks
Directory of Open Access Journals (Sweden)
Carrizosa Emilio
2011-01-01
Full Text Available Finding p prototypes by minimizing the sum of the squared distances from a set of points to its closest prototype is a well-studied problem in clustering, data analysis and continuous location. In this note, this very same problem is addressed assuming, for the first time, that the space of possible prototype locations is a network. We develop some interesting properties of such clustering problem. We also show that optimal cluster prototypes are not necessary located at vertices of the network.
Sums of two-dimensional spectral triples
DEFF Research Database (Denmark)
Christensen, Erik; Ivan, Cristina
2007-01-01
construct a sum of two dimensional modules which reflects some aspects of the topological dimensions of the compact metric space, but this will only give the metric back approximately. At the end we make an explicit computation of the last module for the unit interval in. The metric is recovered exactly......, the Dixmier trace induces a multiple of the Lebesgue integral but the growth of the number of eigenvalues is different from the one found for the standard differential operator on the unit interval....
Dedekind zeta-functions and Dedekind sums
Institute of Scientific and Technical Information of China (English)
陆洪文; 焦荣政; 纪春岗
2002-01-01
In this paper we use Dedekind zeta functions of two real quadratic number fields at -1 to denote Dedekind sums of high rank. Our formula is different from that of Siegel's. As an application, we get a polynomial representation of ζK(-1): ζK(-1) =1/45(26n3-41n±9), n ≡±2(mod 5), where K=Q( q),prime q=4n2+1, and the class number of quadratic number field K2=Q(q) is 1.
Sum-SINR/sum-capacity optimal multisignature spread-spectrum steganography
Wei, Lili; Pados, Dimitris A.; Batalama, Stella N.; Medley, Michael J.
2008-04-01
For any given digital host image or audio file (or group of hosts) and any (block) transform domain of interest, we find an orthogonal set of signatures that achieves maximum sum-signal-to-interference-plus-noise ratio (sum- SINR) spread-spectrum message embedding for any fixed embedding amplitude values. We also find the sumcapacity optimal amplitude allocation scheme for any given total distortion budget under the assumption of (colored) Gaussian transform-domain host data. The practical implication of the results is sum-SINR, sumcapacity optimal multiuser/multisignature spread-spectrum data hiding in the same medium. Theoretically, the findings establish optimality of the recently presented Gkizeli-Pados-Medley multisignature eigen-design algorithm.
The Infinite Sum of Reciprocal of the Fibonacci Numbers
Institute of Scientific and Technical Information of China (English)
Guo Jie ZHANG
2011-01-01
In this paper,we consider infinite sums of the reciprocals of the Fibonacci numbers.Then applying the floor function to the reciprocals of this sums,we obtain a new identity involving the Fibonacci numbers.
Conservation Rules of Direct Sum Decomposition of Groups
Directory of Open Access Journals (Sweden)
Nakasho Kazuhisa
2016-03-01
Full Text Available In this article, conservation rules of the direct sum decomposition of groups are mainly discussed. In the first section, we prepare miscellaneous definitions and theorems for further formalization in Mizar [5]. In the next three sections, we formalized the fact that the property of direct sum decomposition is preserved against the substitutions of the subscript set, flattening of direct sum, and layering of direct sum, respectively. We referred to [14], [13] [6] and [11] in the formalization.
Interpreting the Four Types of Sums of Squares in SPSS.
Tanguma, Jesus; Speed, F. M.
This paper analyzes three possible research designs using each of the four types of sums of squares in the Statistical Package for the Social Sciences (SPSS). When the design is balanced (i.e., each cell has the same number of observations), all of the SPSS types of sums of squares yield equivalent results (testable hypotheses and sums of squares)…
Light four-quark states and QCD sum rule
Institute of Scientific and Technical Information of China (English)
ZHANG Ai-Lin
2009-01-01
The relations among four-quark states, diquarks and QCD sum rules are discussed. The situation of the existing, but incomplete studies of four-quark states with QCD sum rules is analyzed. Masses of some diquark clusters were attempted to be determined by QCD sum rules, and masses of some light tetraquark states were obtained in terms of the diquarks.
27 CFR 24.148 - Penal sums of bonds.
2010-04-01
... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Penal sums of bonds. 24.148 Section 24.148 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU... Penal sums of bonds. The penal sums of bonds prescribed in this part are as follows: Bond Basis...
22 CFR 19.13-1 - Lump-sum credit.
2010-04-01
... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Lump-sum credit. 19.13-1 Section 19.13-1... THE FOREIGN SERVICE RETIREMENT AND DISABILITY SYSTEM § 19.13-1 Lump-sum credit. “Lump-sum credit” is the compulsory and special contributions to a participant's or former participant's credit in the Fund...
42 CFR 411.46 - Lump-sum payments.
2010-10-01
... Covered Under Workers' Compensation § 411.46 Lump-sum payments. (a) Lump-sum commutation of future benefits. If a lump-sum compensation award stipulates that the amount paid is intended to compensate the... payment of workers' compensation benefits, medical expenses incurred after the date of the settlement are...
Logical consistency and sum-constrained linear models
van Perlo -ten Kleij, Frederieke; Steerneman, A.G.M.; Koning, Ruud H.
2006-01-01
A topic that has received quite some attention in the seventies and eighties is logical consistency of sum-constrained linear models. Loosely defined, a sum-constrained model is logically consistent if the restrictions on the parameters and explanatory variables are such that the sum constraint is a
Complexity and demographic explanations of cumulative culture.
Directory of Open Access Journals (Sweden)
Adrien Querbes
Full Text Available Formal models have linked prehistoric and historical instances of technological change (e.g., the Upper Paleolithic transition, cultural loss in Holocene Tasmania, scientific progress since the late nineteenth century to demographic change. According to these models, cumulation of technological complexity is inhibited by decreasing--while favoured by increasing--population levels. Here we show that these findings are contingent on how complexity is defined: demography plays a much more limited role in sustaining cumulative culture in case formal models deploy Herbert Simon's definition of complexity rather than the particular definitions of complexity hitherto assumed. Given that currently available empirical evidence doesn't afford discriminating proper from improper definitions of complexity, our robustness analyses put into question the force of recent demographic explanations of particular episodes of cultural change.
Avoiding Program-Induced Cumulative Overload (PICO).
Orr, Robin; Knapik, Joseph J; Pope, Rodney
2016-01-01
This article defines the concept of program-induced cumulative overload (PICO), provides examples, and advises ways to mitigate the adverse effects. PICO is the excessive cumulative physical workload that can be imparted to military personnel by a military training program with an embedded physical training component. PICO can be acute (accumulating within a single day) or chronic (accumulating across the entirety of the program) and results in adverse outcomes for affected personnel, including detrimental fatigue, performance degradation, injuries, or illness. Strategies to mitigate PICO include focusing administration and logistic practices during the development and ongoing management of a trainee program and implementing known musculoskeletal injury prevention strategies. More training is not always better, and trainers need to consider the total amount of physical activity that military personnel experience across both operational training and physical training if PICO is to be mitigated.
Sharing a quota on cumulative carbon emissions
Raupach, Michael R.; Davis, Steven J.; Peters, Glen P.; Andrew, Robbie M.; Canadell, Josep G.; Ciais, Philippe; Friedlingstein, Pierre; Jotzo, Frank; van Vuuren, Detlef P.; Le Quéré, Corinne
2014-10-01
Any limit on future global warming is associated with a quota on cumulative global CO2 emissions. We translate this global carbon quota to regional and national scales, on a spectrum of sharing principles that extends from continuation of the present distribution of emissions to an equal per-capita distribution of cumulative emissions. A blend of these endpoints emerges as the most viable option. For a carbon quota consistent with a 2 °C warming limit (relative to pre-industrial levels), the necessary long-term mitigation rates are very challenging (typically over 5% per year), both because of strong limits on future emissions from the global carbon quota and also the likely short-term persistence in emissions growth in many regions.
Structural Vibration Monitoring Using Cumulative Spectral Analysis
Directory of Open Access Journals (Sweden)
Satoru Goto
2013-01-01
Full Text Available This paper describes a resonance decay estimation for structural health monitoring in the presence of nonstationary vibrations. In structural health monitoring, the structure's frequency response and resonant decay characteristics are very important for understanding how the structure changes. Cumulative spectral analysis (CSA estimates the frequency decay by using the impulse response. However, measuring the impulse response of buildings is impractical due to the need to shake the building itself. In a previous study, we reported on system damping monitoring using cumulative harmonic analysis (CHA, which is based on CSA. The current study describes scale model experiments on estimating the hidden resonance decay under non-stationary noise conditions by using CSA for structural condition monitoring.
Institute of Scientific and Technical Information of China (English)
汪邦军
2007-01-01
分析了常规控制图在精密制造过程质量的统计控制中的不足,讨论了应用对过程均值小偏移比较敏感的累积和控制图,实现精密制造过程输出质量的统计过程控制的基本原理,并给出了累积和控制图(Cusum)的SAS实现步骤.
2009-01-01
JUSTIFICATIVA E OBJETIVOS: As curvas de aprendizado têm se mostrado ferramentas úteis no monitoramento do desempenho de um trabalhador submetido a uma nova tarefa. Essas curvas vêm sendo utilizadas na avaliação de vários procedimentos na prática médica. O objetivo desta pesquisa foi avaliar o aprendizado da intubação orotraqueal (IOT) com o laringoscópio Truview EVO2® através da curva de aprendizado CUSUM. MÉTODO: Quatro aprendizes realizaram o treinamento da IOT com o laringoscópio Truview E...
Cumulative carbon emissions and the Green Paradox
Ploeg, Frederick Van der
2013-01-01
The green paradox states that a gradually more ambitious climate policy such as a renewables subsidy or an anticipated carbon tax induces fossil fuel owners to extract more rapidly and accelerate global warming. However, if extraction becomes more costly as reserves are depleted, such policies also shorten the fossil fuel era, induce more fossil fuel to be left in the earth, and thus curb cumulative carbon emissions. These consequences are relevant, as global warming depends primarily on cumu...
Expansive Soil Crack Depth under Cumulative Damage
Directory of Open Access Journals (Sweden)
Bei-xiao Shi
2014-01-01
Full Text Available The crack developing depth is a key problem to slope stability of the expansive soil and its project governance and the crack appears under the roles of dry-wet cycle and gradually develops. It is believed from the analysis that, because of its own cohesion, the expansive soil will have a certain amount of deformation under pulling stress but without cracks. The soil body will crack only when the deformation exceeds the ultimate tensile strain that causes cracks. And it is also believed that, due to the combined effect of various environmental factors, particularly changes of the internal water content, the inherent basic physical properties of expansive soil are weakened, and irreversible cumulative damages are eventually formed, resulting in the development of expansive soil cracks in depth. Starting from the perspective of volumetric strain that is caused by water loss, considering the influences of water loss rate and dry-wet cycle on crack developing depth, the crack developing depth calculation model which considers the water loss rate and the cumulative damages is established. Both the proposal of water loss rate and the application of cumulative damage theory to the expansive soil crack development problems try to avoid difficulties in matrix suction measurement, which will surely play a good role in promoting and improving the research of unsaturated expansive soil.
EPA Workshop on Epigenetics and Cumulative Risk ...
Agenda Download the Workshop Agenda (PDF) The workshop included presentations and discussions by scientific experts pertaining to three topics (i.e., epigenetic changes associated with diverse stressors, key science considerations in understanding epigenetic changes, and practical application of epigenetic tools to address cumulative risks from environmental stressors), to address several questions under each topic, and included an opportunity for attendees to participate in break-out groups, provide comments and ask questions. Workshop Goals The workshop seeks to examine the opportunity for use of aggregate epigenetic change as an indicator in cumulative risk assessment for populations exposed to multiple stressors that affect epigenetic status. Epigenetic changes are specific molecular changes around DNA that alter expression of genes. Epigenetic changes include DNA methylation, formation of histone adducts, and changes in micro RNAs. Research today indicates that epigenetic changes are involved in many chronic diseases (cancer, cardiovascular disease, obesity, diabetes, mental health disorders, and asthma). Research has also linked a wide range of stressors including pollution and social factors with occurrence of epigenetic alterations. Epigenetic changes have the potential to reflect impacts of risk factors across multiple stages of life. Only recently receiving attention is the nexus between the factors of cumulative exposure to environmental
Cognitive UWB Spectrum Sensing Algorithm Based On Nonparametric CUSUM%基于非参量CUSUM的认知超宽带频谱感知算法
Institute of Scientific and Technical Information of China (English)
宋晓鸥; 向新; 毕笃彦; 杨宝强
2011-01-01
提出了一种基于非参量CUSUM的超宽带信号快速检测算法,该算法针对认知超宽带频谱感知中超宽带信号检测问题,根据超宽带信号占空比低的特点,选择短时能量作为非参量CUSUM算法的观测统计量,将块检测思想和序列检测思想进行有机结合,克服了块检测算法的信噪比门限效应,并采用加滑动预处理窗的方式降低噪声对观测统计量的影响.本文通过自适应改变非参量CUSUM算法中Reference Value取值的方法,提出改进算法以进一步缩短检测延迟.仿真证明,占空比为1/10、信噪比为-25dB时,所提算法可在用户发送50个脉冲的时间内以90％的概率检测出主用户信号的存在,而能量检测算法在8dB时才能达到相同检测概率,且所提算法检测延迟小于能量检测算法.改进算法在-10dB≤SNR≤5dB时,改进算法检测延迟小于本文所提算法,但5dB＜SNR时,检测延迟基本相同.%Based on nonparametric CUSUM algorithm, an UWB signal quickest detection algorithm is proposed, to solve the problem of UWB signal detection in CUWB (cognitive UWB) system. According to the low duty ratio property of UWB signal, short time energy is selected as the observation statistic to connect the block detection idea and the sequence detection idea, which conquers the SNR wall problem. A slipped pretreatment window is adopted to depress the noise interference to observation statistic. To more decrease the detection delay, the Reference Value of CUSUM algorithm is adaptively changed in improved algorithm. It is improved by simulation that the proposed algorithm can achieve more than 90% detection probability, under the condition that duty ratio is 1/6 and SNR = -25dB, within 50 transmitted pulses, and energy detection algorithm can achieve the same detection probability when SNR = 8dB. Under the condition -10dB
Character sums for primitive root densities
Lenstra, H W; Stevenhagen, P
2011-01-01
It follows from the work of Artin and Hooley that, under assumption of the generalized Riemann hypothesis, the density of the set of primes $q$ for which a given non-zero rational number $r$ is a primitive root modulo $q$ can be written as an infinite product $\\prod_p \\delta_p$ of local factors $\\delta_p$ reflecting the degree of the splitting field of $X^p-r$ at the primes $p$, multiplied by a somewhat complicated factor that corrects for the `entanglement' of these splitting fields. We show how the correction factors arising in Artin's original primitive root problem and some of its generalizations can be interpreted as character sums describing the nature of the entanglement. The resulting description in terms of local contributions is so transparent that it greatly facilitates explicit computations, and naturally leads to non-vanishing criteria for the correction factors.
On Zero Sum Subsequences of Restricted Size
Indian Academy of Sciences (India)
B K Moriya
2010-09-01
Let be a finite abelian group with $\\exp(G)=e$. Let $s(G)$ be the minimal integer with the property that any sequence of elements in contains an -term subsequence with sum zero. Let , and be positive integers and ≥ 3. Furthermore, $(C^r_m)=a_r(m-1)+1$, for some constant $a_r$ depending on and is a fixed positive integer such that $$n≥\\frac{m^r(c(r)m-a_r(m-1)+m-3)(m-1)-(m+1)+(m+1)(a_r+1)}{m(m+1)(a_r+1)}$$ and $s(C^r_n)=(a_r+1)(n-1)+1$. In the above lower bound on $n,c(r)$ is the Alon-Dubiner constant. Then $s(C^r_{nm})=(a_r+1)(nm-1)+1$.
Nonlocal Condensate Model for QCD Sum Rules
Hsieh, Ron-Chou
2009-01-01
We include effects of nonlocal quark condensates into QCD sum rules (QSR) via the K$\\ddot{\\mathrm{a}}$ll$\\acute{\\mathrm{e}}$n-Lehmann representation for a dressed fermion propagator, in which a negative spectral density function manifests their nonperturbative nature. Applying our formalism to the pion form factor as an example, QSR results are in good agreement with data for momentum transfer squared up to $Q^2 \\approx 10 $ GeV$^2$. It is observed that the nonlocal quark-condensate contribution descends like $1/Q^4$, different from the exponential decrease in $Q^2$ obtained in the literature, and contrary to the linear rise in the local-condensate approximation.
Scattering and; Delay, Scale, and Sum Migration
Energy Technology Data Exchange (ETDEWEB)
Lehman, S K
2011-07-06
How do we see? What is the mechanism? Consider standing in an open field on a clear sunny day. In the field are a yellow dog and a blue ball. From a wave-based remote sensing point of view the sun is a source of radiation. It is a broadband electromagnetic source which, for the purposes of this introduction, only the visible spectrum is considered (approximately 390 to 750 nanometers or 400 to 769 TeraHertz). The source emits an incident field into the known background environment which, for this example, is free space. The incident field propagates until it strikes an object or target, either the yellow dog or the blue ball. The interaction of the incident field with an object results in a scattered field. The scattered field arises from a mis-match between the background refractive index, considered to be unity, and the scattering object refractive index ('yellow' for the case of the dog, and 'blue' for the ball). This is also known as an impedance mis-match. The scattering objects are referred to as secondary sources of radiation, that radiation being the scattered field which propagates until it is measured by the two receivers known as 'eyes'. The eyes focus the measured scattered field to form images which are processed by the 'wetware' of the brain for detection, identification, and localization. When time series representations of the measured scattered field are available, the image forming focusing process can be mathematically modeled by delayed, scaled, and summed migration. This concept of optical propagation, scattering, and focusing have one-to-one equivalents in the acoustic realm. This document is intended to present the basic concepts of scalar scattering and migration used in wide band wave-based remote sensing and imaging. The terms beamforming and (delayed, scaled, and summed) migration are used interchangeably but are to be distinguished from the narrow band (frequency domain) beamforming to determine
QCD Sum Rules Study of X(4350)
Mo, Zeng; Cui, Chun-Yu; Liu, Yong-Lu; Huang, Ming-Qiu
2014-04-01
The QCD sum rule approach is used to analyze the nature of the recently observed new resonance X(4350), which is assumed to be a diquark-antidiquark state [cs][bar cbar s] with JPC = 1-+. The interpolating current representing this state is proposed. In the calculation, contributions of operators up to dimension six are included in the operator product expansion (OPE), as well as terms which are linear in the strange quark mass ms. We find m1-+ = (4.82 ± 0.19) GeV, which is not compatible with the X(4350) structure as a 1-+ tetraquark state. Finally, we also discuss the difference of a four-quark state's mass whether the state's interpolating current has a definite charge conjugation.
Sum of Bernoulli Mixtures: Beyond Conditional Independence
Directory of Open Access Journals (Sweden)
Taehan Bae
2014-01-01
Full Text Available We consider the distribution of the sum of Bernoulli mixtures under a general dependence structure. The level of dependence is measured in terms of a limiting conditional correlation between two of the Bernoulli random variables. The conditioning event is that the mixing random variable is larger than a threshold and the limit is with respect to the threshold tending to one. The large-sample distribution of the empirical frequency and its use in approximating the risk measures, value at risk and conditional tail expectation, are presented for a new class of models which we call double mixtures. Several illustrative examples with a Beta mixing distribution, are given. As well, some data from the area of credit risk are fit with the models, and comparisons are made between the new models and also the classical Beta-binomial model.
Exponential Approximations Using Fourier Series Partial Sums
Banerjee, Nana S.; Geer, James F.
1997-01-01
The problem of accurately reconstructing a piece-wise smooth, 2(pi)-periodic function f and its first few derivatives, given only a truncated Fourier series representation of f, is studied and solved. The reconstruction process is divided into two steps. In the first step, the first 2N + 1 Fourier coefficients of f are used to approximate the locations and magnitudes of the discontinuities in f and its first M derivatives. This is accomplished by first finding initial estimates of these quantities based on certain properties of Gibbs phenomenon, and then refining these estimates by fitting the asymptotic form of the Fourier coefficients to the given coefficients using a least-squares approach. It is conjectured that the locations of the singularities are approximated to within O(N(sup -M-2), and the associated jump of the k(sup th) derivative of f is approximated to within O(N(sup -M-l+k), as N approaches infinity, and the method is robust. These estimates are then used with a class of singular basis functions, which have certain 'built-in' singularities, to construct a new sequence of approximations to f. Each of these new approximations is the sum of a piecewise smooth function and a new Fourier series partial sum. When N is proportional to M, it is shown that these new approximations, and their derivatives, converge exponentially in the maximum norm to f, and its corresponding derivatives, except in the union of a finite number of small open intervals containing the points of singularity of f. The total measure of these intervals decreases exponentially to zero as M approaches infinity. The technique is illustrated with several examples.
Botnet Anomaly Traffic Detection Based on Modified-CUSUM Algorithms%基于改进CUSUM算法的僵尸网络流量异常检测
Institute of Scientific and Technical Information of China (English)
来犇; 张怡
2012-01-01
The detection of Botnet has become one of the hot spots in network security research. An extinct characteristic of Botnet is to build up C＆C channel through which the attacker would be able to send commands to bots and receive the responses. The response action is likely to cause a sudden change in network traffic. Based on the characteristic of the change point, we propose an improved CUSUM algorithm in this paper to detect the change point in network traffic of Botnet. The experiment result shows that the algorithm we proposed is effective to detect the change point in network traffic of Botnet with a higher detection ratio and a higher accuracy.%僵尸网络（Botnet）检测已经成为近年来网络安全领域的研究热点之一，Botnet的一个显著特点是能建立C＆C通道，攻击者可以通过这个通道给bots发送命令，并接收与命令相对应的响应，而响应往往会引起网络流量的突变。基于这一特点，本文提出一种改进的CUSUM的算法，对僵尸网络流量中的突变点进行检测。经实验表明，本文所采用的算法是有效的，能有效地检测出流量中的突变点，并且能提高检测速度和准确率。
CUSUM Expectations and Warning Threshold Optimization Research of the Algorithm%CUSUM算法期望值及警告阈值优化研究
Institute of Scientific and Technical Information of China (English)
邓绯
2015-01-01
With the in‐depth development of economic globalization ,the revolution of science and technology constantly breakthroughs ,with the greatest information network technology ,the progress of the information network will also constantly human beings into a new historical height .But at the same time the network invasion rate also increased ,become the one big drawback of network technology .In order to reduce the invasion of the attacker to network and reduce the attack means ,and on the basis of the original algorithm using CUSUM algorithm to detect network intrusion ,and optimize their expecta‐tions and warning threshold (s) .After testing found that the improved algorithm are more accuracy than the original algorithm .%随着经济全球化深入发展，科技革命不断取得突破，其中以信息网络技术为最，信息网络化的进程也不断将人类推向新的历史高度。但与此同时网络入侵率也随之增加，成为了网络技术的一大弊端。为了降低攻击者对网络的入侵和减少攻击手段，在原算法的基础上采用CUSUM算法来检测网络入侵，并优化其期望值和警告阈值。经检测发现，改善后的算法比原算法更具检测精度。
On solving equations of algebraic sum of equal powers
Institute of Scientific and Technical Information of China (English)
WANG Xinghua; YANG Shijun
2006-01-01
It is well known that a system of equations of sum of equal powers can be converted to an algebraic equation of higher degree via Newton's identities. This is the Viete-Newton theorem. This work reports the generalizations of the Viete-Newton theorem to a system of equations of algebraic sum of equal powers. By exploiting some facts from algebra and combinatorics,it is shown that a system of equations of algebraic sum of equal powers can be converted in a closed form to two algebraic equations, whose degree sum equals the number of unknowns of the system of equations of algebraic sum of equal powers.
Definition and Properties of Direct Sum Decomposition of Groups1
Directory of Open Access Journals (Sweden)
Nakasho Kazuhisa
2015-03-01
Full Text Available In this article, direct sum decomposition of group is mainly discussed. In the second section, support of element of direct product group is defined and its properties are formalized. It is formalized here that an element of direct product group belongs to its direct sum if and only if support of the element is finite. In the third section, product map and sum map are prepared. In the fourth section, internal and external direct sum are defined. In the last section, an equivalent form of internal direct sum is proved. We referred to [23], [22], [8] and [18] in the formalization.
Equivalent Expressions of Direct Sum Decomposition of Groups1
Directory of Open Access Journals (Sweden)
Nakasho Kazuhisa
2015-03-01
Full Text Available In this article, the equivalent expressions of the direct sum decomposition of groups are mainly discussed. In the first section, we formalize the fact that the internal direct sum decomposition can be defined as normal subgroups and some of their properties. In the second section, we formalize an equivalent form of internal direct sum of commutative groups. In the last section, we formalize that the external direct sum leads an internal direct sum. We referred to [19], [18] [8] and [14] in the formalization.
Scalar Glueballs A Gaussian Sum-rules Analysis
Harnett, D
2002-01-01
Although marginally more complicated than the traditional laplace sum-rules, gaussian sum-rules have the advantage of being able to probe excited and ground hadronic states with similar sensitivity. Gaussian sum-rule analysis techniques are applied to the problematic scalar glueball channel to determine masses, widths, and relative resonance strengths of low-lying scalar glueball states contributing to the hadronic spectral function. An important feature of our analysis is the inclusion of instanton contributions to the scalar gluonic correlation function. Compared with the next-to-leading gaussian sum- rule, the analysis of the lowest weighted sum-rule (which contains a large scale independent contribution from the low energy theorem) is shown to be unreliable because of instability under QCD uncertainties. However, the presence of instanton effects leads to approximately consistent mass scales in the lowest weighted and next- lowest weighted sum-rules. The analysis of the next-to- leading sum-rule demonstra...
DEFF Research Database (Denmark)
Lopes Antunes, Ana Carolina; Dorea, Fernanda; Hisham Beshara Halasa, Tariq;
2016-01-01
(number of sentinel herds tested in the surveillance system) on the performance of the algorithms. Three univariate process monitoring control algorithms were compared: Shewart p Chart 1 (PSHEW), Cumulative Sum2 (CUSUM) and Exponentially Weighted Moving Average3 (EWMA). Increases in seroprevalence were......, it was possible to assess the accuracy and timeliness of the surveillance system working in real-time. The results showed that EWMA and PSHEW had higher CumSe (when compared with the CUSUM) from week 1 until the end of the period for all simulated scenarios. Changes in seroprevalence from 0.10 to 0.20 were more...... easily detected (higher CumSe) than changes from 0.10 to 0.15 for all three algorithms. Similar results were found with EWMA and PSHEW, based on the median time to detection. Changes in the seroprevalence were detected later with CUSUM, compared to EWMA and PSHEW for the different scenarios. Increasing...
Cumulative risks of foster care placement for Danish children
National Research Council Canada - National Science Library
Fallesen, Peter; Emanuel, Natalia; Wildeman, Christopher
2014-01-01
Although recent research suggests that the cumulative risk of foster care placement is far higher for American children than originally suspected, little is known about the cumulative risk of foster...
Recursive Numerical Evaluation of the Cumulative Bivariate Normal Distribution
Meyer, Christian
2010-01-01
We propose an algorithm for evaluation of the cumulative bivariate normal distribution, building upon Marsaglia's ideas for evaluation of the cumulative univariate normal distribution. The algorithm is mathematically transparent, delivers competitive performance and can easily be extended to arbitrary precision.
Climate mitigation: sustainable preferences and cumulative carbon
Buckle, Simon
2010-05-01
We develop a stylized AK growth model with both climate damages to ecosystem goods and services and sustainable preferences that allow trade-offs between present discounted utility and long-run climate damages. The simplicity of the model permits analytical solutions. Concern for the long-term provides a strong driver for mitigation action. One plausible specification of sustainable preferences leads to the result that, for a range of initial parameter values, an optimizing agent would choose a level of cumulative carbon dioxide (CO2) emissions independent of initial production capital endowment and CO2 levels. There is no technological change so, for economies with sufficiently high initial capital and CO2 endowments, optimal mitigation will lead to disinvestment. For lower values of initial capital and/or CO2 levels, positive investment can be optimal, but still within the same overall level of cumulative emissions. One striking aspect of the model is the complexity of possible outcomes, in addition to these optimal solutions. We also identify a resource constrained region and several regions where climate damages exceed resources available for consumption. Other specifications of sustainable preferences are discussed, as is the case of a hard constraint on long-run damages. Scientists are currently highlighting the potential importance of the cumulative carbon emissions concept as a robust yet flexible target for climate policymakers. This paper shows that it also has an ethical interpretation: it embodies an implicit trade off in global welfare between present discounted welfare and long-term climate damages. We hope that further development of the ideas presented here might contribute to the research and policy debate on the critical areas of intra- and intergenerational welfare.
A Study on the CUSUM Control Chart in Fluorine Filling of Air Conditioners%CUSUM控制图在空调充氟生产过程中的应用研究
Institute of Scientific and Technical Information of China (English)
何桢; 雷毅; 生静; 毛文峰
2000-01-01
Traditional Shewhart control charts have low power in detecting mean shift of quality characteristics under control. When an individual-moving range control chart(X-Rm) is used to control its deviations of fluorine filling amount, It is found that X-Rm is too insensitive to the shift of the deviations and unable to calibrate its fluorine filling machines in time. A CUSUM control chart is used to solve the problem and to improve machine calibration, which results in high quality and low cost in fluorine filling process.%经典的休哈特控制图对质量特征值的均值波动检出力较弱。采用单值-移动极差控制图控制空调充氟量在短期内往往很难发现充氟量偏差值的漂移，导致充氟量偏差调整不及时。本文采用累积和控制图(CUSUM)来控制充氟量偏差的变化，改进了充氟偏差调整方式，在保证质量的同时降低了生产成本。
Institute of Scientific and Technical Information of China (English)
张云贵; 佟为明; 赵永丽
2014-01-01
根据工业控制系统高度实时性和可用性要求，采用统计分析方法，对常规CUSUM异常检测算法的判别函数进行改进，并将改进后的算法用于钢铁企业热风炉拱顶温度控制系统入侵检测中，结果表明，通过改进的CUSUM异常检测算法，基本能够消除随机偏差的影响，实现低误报率的在线入侵检测。%According to high real-time and availability requirements of industrial control systems,the discriminant function of routine CUSUM anomaly detection algorithm is improved by using the statisti-cal analysis method. Finally,the improved algorithm is applied in the intrusion detection of the hot-blast furnace temperature control system in iron and steel enterprises. Results show that the improved CUSUM algorithm can eliminate the random deviation influence and realize the online intrusion de-tection at a low false alarm rate.
Institute of Scientific and Technical Information of China (English)
李绍晖; 刘纪伟
2015-01-01
针对CUSUM异常检测算法在入侵检测应用中存在的固定偏移常数和固定检测门限的问题,结合工业控制系统高实时性和高可用性的要求,提出一种面向工业控制系统、具有自适应特征的改进非参数CUSUM(D-CUSUM)入侵检测方法.与以往凭经验设置固定值不同,算法基于概率论中著名的柯尔莫哥洛夫不等式理论重新设计了非参数CUSUM偏移常数β的生成方法,通过外部参数-告警控制参数动态设置CUSUM算法的检测门限TN,使β和TN具有自适应特性.在基于MATLAB Simulink的温度控制系统攻击仿真实验中,证明改进的非参数CUSUM异常检测算法能够改善检测的实时性和误报率,实现对工业控制系统的低误报率实时入侵检测.
Long and Short Term Cumulative Structural Priming Effects
Kaschak, Michael P.; Kutta, Timothy J.; Coyle, Jacqueline M.
2012-01-01
We present six experiments that examine cumulative structural priming effects (i.e., structural priming effects that accumulate across many utterances). Of particular interest is whether (1) cumulative priming effects transfer across language production tasks and (2) the transfer of cumulative priming effects across tasks persists over the course of a week. Our data suggest that cumulative structural priming effects do transfer across language production tasks (e.g., from written stem complet...
Preserved cumulative semantic interference despite amnesia
Directory of Open Access Journals (Sweden)
Gary Michael Oppenheim
2015-05-01
As predicted by Oppenheim et al’s (2010 implicit incremental learning account, WRP’s BCN RTs demonstrated strong (and significant repetition priming and semantic blocking effects (Figure 1. Similar to typical results from neurally intact undergraduates, WRP took longer to name pictures presented in semantically homogeneous blocks than in heterogeneous blocks, an effect that increased with each cycle. This result challenges accounts that ascribe cumulative semantic interference in this task to explicit memory mechanisms, instead suggesting that the effect has the sort of implicit learning bases that are typically spared in hippocampal amnesia.
Cumulant matching for independent source extraction.
Phlypo, Ronald; Zarzoso, Vicente; Comon, Pierre; Lemahieu, Ignace
2008-01-01
In this work we show how one can make use of priors on signal statistics under the form of cumulant guesses to extract an independent source from an observed mixture. The advantage of using statistical priors on the signal lies in the fact that no specific knowledge is needed about its temporal behavior, neither about its spatial distribution. We show that these statistics can be obtained either by reasoning on the theoretical values of a supposed waveform, either by using a subset of the observations from which we know that their statistics are merely hindered by interferences. Results on an electro-cardiographic recording confirm the above assumptions.
A Missing Link in the Evolution of the Cumulative Recorder
Asano, Toshio; Lattal, Kennon A.
2012-01-01
A recently recovered cumulative recorder provides a missing link in the evolution of the cumulative recorder from a modified kymograph to a reliably operating, scientifically and commercially successful instrument. The recorder, the only physical evidence of such an early precommercial cumulative recorder yet found, was sent to Keio University in…
Original and cumulative prospect theory: a discussion of empirical differences
P.P. Wakker; H. Fennema
1997-01-01
This note discusses differences between prospect theory and cumulative prospect theory. It shows that cumulative prospect theory is not merely a formal correction of some theoretical problems in prospect theory, but it also gives different predictions. Experiments are described that favor cumulative
Large convexly independent subsets of Minkowski sums
Swanepoel, Konrad J
2010-01-01
Let $E_d(n)$ be the maximum number of pairs that can be selected from a set of $n$ points in $R^d$ such that the midpoints of these pairs are convexly independent. We show that $E_2(n)\\geq \\Omega(n\\sqrt{\\log n})$, which answers a question of Eisenbrand, Pach, Rothvo\\ss, and Sopher (2008) on large convexly independent subsets in Minkowski sums of finite planar sets, as well as a question of Halman, Onn, and Rothblum (2007). We also show that $\\lfloor\\frac{1}{3}n^2\\rfloor\\leq E_3(n)\\leq \\frac{3}{8}n^2+O(n^{3/2})$. Let $W_d(n)$ be the maximum number of pairwise nonparallel unit distance pairs in a set of $n$ points in some $d$-dimensional strictly convex normed space. We show that $W_2(n)=\\Theta(E_2(n))$ and for $d\\geq 3$ that $W_d(n)\\sim\\frac12\\left(1-\\frac{1}{a(d)}\\right)n^2$, where $a(d)\\in N$ is related to strictly antipodal families. In fact we show that the same asymptotics hold without the requirement that the unit distance pairs form pairwise nonparallel segments, and also if diameter pairs are considere...
Level-1 Jets and Sums Trigger Performance
CMS Collaboration
2016-01-01
After the first long shutdown, the LHC has restarted at a centre-of-mass energy of 13 TeV. The LHC is expected to achieve an instantaneous luminosity larger than $10^{34} \\rm{cm}^{-2} \\rm{s}^{-1}$ and an average number of pile-up interactions of at least 40. The CMS Level-1 trigger architecture has undergone a full upgrade in order to maintain and improve the trigger performance under these new conditions. It will allow CMS to keep the trigger rate under control and to avoid a significant increase in trigger thresholds that would have a negative impact on the CMS physics programme. First studies of the performance of the calorimeter trigger upgrade for jets and energy sums are shown. Details of the algorithms and commissioning may be found in CMS-DP-2015-051 and the CMS Technical Design Report for the Level-1 Trigger upgrade: CERN-LHCC-2013-011, CMS-TDR-12 (2013)
Cumulative Environmental Management Association : Wood Buffalo Region
Energy Technology Data Exchange (ETDEWEB)
Friesen, B. [Syncrude Canada Ltd., Edmonton, AB (Canada)
2001-07-01
The recently announced oil sands development of the Wood Buffalo Region in Alberta was the focus of this power point presentation. Both mining and in situ development is expected to total $26 billion and 2.6 million barrels per day of bitumen production. This paper described the economic, social and environmental challenges facing the resource development of this region. In addition to the proposed oil sands projects, this region will accommodate the needs of conventional oil and gas production, forestry, building of pipelines and power lines, municipal development, recreation, tourism, mining exploration and open cast mining. The Cumulative Environmental Management Association (CEMA) was inaugurated as a non-profit association in April 2000, and includes 41 members from all sectors. Its major role is to ensure a sustainable ecosystem and to avoid any cumulative impacts on wildlife. Other work underway includes the study of soil and plant species diversity, and the effects of air emissions on human health, wildlife and vegetation. The bioaccumulation of heavy metals and their impacts on surface water and fish is also under consideration to ensure the quality and quantity of surface water and ground water. 3 figs.
Cumulative environmental management and the oil sands
Energy Technology Data Exchange (ETDEWEB)
NONE
2005-07-01
In response to concerns regarding the cumulative environmental impacts of oil sands development within the Athabasca oil sands deposit, the government of Alberta established a Regional Sustainable Development Strategy (RSDS) to balance development with environmental protection. The environmental issues identified through the RSDS were addressed by the Cumulative Environmental Management Association (CEMA). CEMA's boundary is the Wood Buffalo region of northeastern Alberta. It identifies existing and future environmental effects in the region and proposes recommendations to regulatory bodies for reducing environmental impacts associated with oil sands development. This presentation outlined some of the 55 stakeholder representatives of CEMA, including Alberta government departments associated with resource development, oil sand developers within the region, and Aboriginal communities and First Nations. These stakeholders provide input on sector priorities and agree on environmental thresholds. Established working groups also address technical and scientific research issues identified in the RSDS such as sustainable ecosystems; surface waters; trace metals and air contaminants; nitrogen oxides and sulphur dioxides; and land reclamation. To date, CEMA has submitted more than 50 reports and has made 4 major environmental recommendations for trace metal management, ecosystem management tools, a framework for acid deposition management, and a landscape design checklist. tabs., figs.
Higher Order Cumulants in Colorless Partonic Plasma
Cherif, S; Ladrem, M
2016-01-01
Any physical system considered to study the QCD deconfinement phase transition certainly has a finite volume, so the finite size effects are inevitably present. This renders the location of the phase transition and the determination of its order as an extremely difficult task, even in the simplest known cases. In order to identify and locate the colorless QCD deconfinement transition point in finite volume $T_{0}(V)$, a new approach based on the finite-size cumulant expansion of the order parameter and the $\\mathscr{L}_{m,n}$-Method is used.We have shown that both cumulants of higher order and their ratios, associated to the thermodynamical fluctuations of the order parameter, in QCD deconfinement phase transition behave in a particular enough way revealing pronounced oscillations in the transition region. The sign structure and the oscillatory behavior of these in the vicinity of the deconfinement phase transition point might be a sensitive probe and may allow one to elucidate their relation to the QCD phase...
Innovativeness, population size and cumulative cultural evolution.
Kobayashi, Yutaka; Aoki, Kenichi
2012-08-01
Henrich [Henrich, J., 2004. Demography and cultural evolution: how adaptive cultural processes can produce maladaptive losses-the Tasmanian case. Am. Antiquity 69, 197-214] proposed a model designed to show that larger population size facilitates cumulative cultural evolution toward higher skill levels. In this model, each newborn attempts to imitate the most highly skilled individual of the parental generation by directly-biased social learning, but the skill level he/she acquires deviates probabilistically from that of the exemplar (cultural parent). The probability that the skill level of the imitator exceeds that of the exemplar can be regarded as the innovation rate. After reformulating Henrich's model rigorously, we introduce an overlapping-generations analog based on the Moran model and derive an approximate formula for the expected change per generation of the highest skill level in the population. For large population size, our overlapping-generations model predicts a much larger effect of population size than Henrich's discrete-generations model. We then investigate by way of Monte Carlo simulations the case where each newborn chooses as his/her exemplar the most highly skilled individual from among a limited number of acquaintances. When the number of acquaintances is small relative to the population size, we find that a change in the innovation rate contributes more than a proportional change in population size to the cumulative cultural evolution of skill level.
Hebron, Judith; Oldfield, Jeremy; Humphrey, Neil
2017-04-01
Students with autism are more likely to be bullied than their typically developing peers. However, several studies have shown that their likelihood of being bullied increases in the context of exposure to certain risk factors (e.g. behaviour difficulties and poor peer relationships). This study explores vulnerability to bullying from a cumulative risk perspective, where the number of risks rather than their nature is considered. A total of 722 teachers and 119 parents of young people with autism spectrum conditions participated in the study. Established risk factors were summed to form a cumulative risk score in teacher and parent models. There was evidence of a cumulative risk effect in both models, suggesting that as the number of risks increased, so did exposure to bullying. A quadratic effect was found in the teacher model, indicating that there was a disproportionate increase in the likelihood of being bullied in relation to the number of risk factors to which a young person was exposed. In light of these findings, it is proposed that more attention needs to be given to the number of risks to which children and young people with autism spectrum conditions are exposed when planning interventions and providing a suitable educational environment.
The subsequence weight distribution of summed maximum length digital sequences
Weathers, G. D.; Graf, E. R.; Wallace, G. R.
1974-01-01
An attempt is made to develop mathematical formulas to provide the basis for the design of pseudorandom signals intended for applications requiring accurate knowledge of the statistics of the signals. The analysis approach involves calculating the first five central moments of the weight distribution of subsequences of hybrid-sum sequences. The hybrid-sum sequence is formed from the modulo-two sum of k maximum length sequences and is an extension of the sum sequences formed from two maximum length sequences that Gilson (1966) evaluated. The weight distribution of the subsequences serves as an approximation to the filtering process. The basic reason for the analysis of hybrid-sum sequences is to establish a large group of sequences with good statistical properties. It is shown that this can be accomplished much more efficiently using the hybrid-sum approach rather than forming the group strictly from maximum length sequences.
Central Binomial Sums, Multiple Clausen Values and Zeta Values
Borwein, J M; Kamnitzer, J
2000-01-01
We find and prove relationships between Riemann zeta values and central binomial sums. We also investigate alternating binomial sums (also called Ap\\'ery sums). The study of non-alternating sums leads to an investigation of different types of sums which we call multiple Clausen values. The study of alternating sums leads to a tower of experimental results involving polylogarithms in the golden ratio. In the non-alternating case, there is a strong connection to polylogarithms of the sixth root of unity, encountered in the 3-loop Feynman diagrams of {\\tt hep-th/9803091} and subsequently in hep-ph/9910223, hep-ph/9910224, cond-mat/9911452 and hep-th/0004010.
Gaussian Sum-Rules, Scalar Gluonium, and Instantons
Steele, T G; Orlandini, G
2002-01-01
Gaussian sum-rules relate a QCD prediction to a two-parameter Gaussian-weighted integral of a hadronic spectral function, providing a clear conceptual connection to quark-hadron duality. In contrast to Laplace sum-rules, the Gaussian sum-rules exhibit enhanced sensitivity to excited states of the hadronic spectral function. The formulation of Gaussian sum-rules and associated analysis techniques for extracting hadronic properties from the sum-rules are reviewed and applied to scalar gluonium. With the inclusion of instanton effects, the Gaussian sum-rule analysis results in a consistent scenario where the gluonic resonance strength is spread over a broad energy range below 1.6 GeV, and indicates the presence of gluonium content in more than one hadronic state.
Operator-sum representation for bosonic Gaussian channels
Energy Technology Data Exchange (ETDEWEB)
Ivan, J. Solomon; Sabapathy, Krishna Kumar; Simon, R. [Raman Research Institute, C. V. Raman Avenue, Sadashivanagar, Bangalore 560 080 (India); Optics and Quantum Information Group, The Institute of Mathematical Sciences, C.I.T. Campus, Tharamani, Chennai 600 113 (India)
2011-10-15
Operator-sum or Kraus representations for single-mode bosonic Gaussian channels are developed, and several of their consequences explored. The fact that the two-mode metaplectic operators acting as unitary purification of these channels do not, in their canonical form, mix the position and momentum variables is exploited to present a procedure which applies uniformly to all families in the Holevo classification. In this procedure the Kraus operators of every quantum-limited Gaussian channel can be simply read off from the matrix elements of a corresponding metaplectic operator. Kraus operators are employed to bring out, in the Fock basis, the manner in which the antilinear, unphysical matrix transposition map when accompanied by injection of a threshold classical noise becomes a physical channel, denoted D({kappa}) in the Holevo classification. The matrix transposition channels D({kappa}), D({kappa}{sup -1}) turn out to be a dual pair in the sense that their Kraus operators are related by the adjoint operation. The amplifier channel with amplification factor {kappa} and the beam-splitter channel with attenuation factor {kappa}{sup -1} turn out to be mutually dual in the same sense. The action of the quantum-limited attenuator and amplifier channels as simply scaling maps on suitable quasiprobabilities in phase space is examined in the Kraus picture. Consideration of cumulants is used to examine the issue of fixed points. The semigroup property of the amplifier and attenuator families leads in both cases to a Zeno-like effect arising as a consequence of interrupted evolution. In the cases of entanglement-breaking channels a description in terms of rank 1 Kraus operators is shown to emerge quite simply. In contradistinction, it is shown that there is not even one finite rank operator in the entire linear span of Kraus operators of the quantum-limited amplifier or attenuator families, an assertion far stronger than the statement that these are not entanglement
Twisted exponential sums of polynomials in one variable
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
The twisted T-adic exponential sums associated to a polynomial in one variable are studied.An explicit arithmetic polygon in terms of the highest two exponents of the polynomial is proved to be a lower bound of the Newton polygon of the C-function of the twisted T-adic exponential sums.This bound gives lower bounds for the Newton polygon of the L-function of twisted p-power order exponential sums.
27 CFR 25.93 - Penal sum of bond.
2010-04-01
... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Penal sum of bond. 25.93... OF THE TREASURY LIQUORS BEER Bonds and Consents of Surety § 25.93 Penal sum of bond. (a)(1) Brewers....164(c)(2), the penal sum of the brewers bond must be equal to 10 percent of the maximum amount of...
Exponential convergence rates for weighted sums in noncommutative probability space
Choi, Byoung Jin; Ji, Un Cig
2016-11-01
We study exponential convergence rates for weighted sums of successive independent random variables in a noncommutative probability space of which the weights are in a von Neumann algebra. Then we prove a noncommutative extension of the result for the exponential convergence rate by Baum, Katz and Read. As applications, we first study a large deviation type inequality for weighted sums in a noncommutative probability space, and secondly we study exponential convergence rates for weighted free additive convolution sums of probability measures.
Sum Rule for a Schiff-Like Dipole Moment
Raduta, A. A.; Budaca, R.
The energy-weighted sum rule for an electric dipole transition operator of a Schiff type differs from the Thomas-Reiche-Kuhn (TRK) sum rule by several corrective terms which depend on the number of system components, N. For illustration the formalism was applied to the case of Na clusters. One concludes that the random phase approximation (RPA) results for Na clusters obey the modified TRK sum rule.
Nuclear pions and the Gottfried and Bjorken sum rules
Energy Technology Data Exchange (ETDEWEB)
Epele, L.N. (Lab. de Fisica Teorica, Dept. de Fisica, Univ. Nacional de La Plata (Argentina)); Fanchiotti, H. (Lab. de Fisica Teorica, Dept. de Fisica, Univ. Nacional de La Plata (Argentina)); Garcia Canal, C.A. (Lab. de Fisica Teorica, Dept. de Fisica, Univ. Nacional de La Plata (Argentina)); Leader, E. (Birkbeck Coll., Univ. of London (United Kingdom)); Sassot, R. (Lab. de Fisica Teorica, Dept. de Fisica, Univ. Nacional de La Plata (Argentina))
1994-10-01
An extremely simple but instructive, ''toy'' model is presented which shows that a small excess of pions in the nucleus can produce a significant change in the values expected for the Gottfried sum rule. The general question of the convergence of the sum rule and of the convergence of the experimental integral is also discussed. It is demonstrated that conclusions about the sum rule, based on deuterium data, are surprisingly model dependent. In contrast, it is stressed, that the Bjorken sum rule can be tested significantly using deuterium data. (orig.)
PROBABILITY INEQUALITIES FOR SUMS OF INDEPENDENT UNBOUNDED RANDOM VARIABLES
Institute of Scientific and Technical Information of China (English)
张涤新; 王志诚
2001-01-01
The tail probability inequalities for the sum of independent unbounded random variables on a probability space ( Ω , T, P) were studied and a new method was proposed to treat the sum of independent unbounded random variables by truncating the original probability space (Ω, T, P ). The probability exponential inequalities for sums of independent unbounded random variables were given. As applications of the results, some interesting examples were given. The examples show that the method proposed in the paper and the results of the paper are quite useful in the study of the large sample properties of the sums of independent unbounded random variables.
Nahm sums, stability and the colored Jones polynomial
Garoufalidis, Stavros
2011-01-01
Nahm sums are $q$-series of a special hypergeometric type that appear in character formulas in Conformal Field Theory, and give rise to elements ot the Bloch group, and have interesting modularity properties. In our paper, we show how Nahm sums arise natural in Quantum Knot Theory, namely we prove the stability of the coefficients of an alternating link and present a Nahm sum formula for the resulting power series, defined in terms of a reduced, downward diagram of an alternating link. The Nahm sum formula comes with a computer implementation, illustrated in numerous examples of proven or conjectural identities among $q$-series.
On minimum sum representations for weighted voting games
Kurz, Sascha
2011-01-01
A proposal in a weighted voting game is accepted if the sum of the (non-negative) weights of the "yea" voters is at least as large as a given quota. Several authors have considered representations of weighted voting games with minimum sum, where the weights and the quota are restricted to be integers. Freixas and Molinero have classified all weighted voting games without a unique minimum sum representation for up to 8 voters. Here we exhaustively classify all weighted voting games consisting of 9 voters which do not admit a unique minimum sum integer weight representation.
Tuning sum rules with window functions for optical constant evaluation
Rodríguez-de Marcos, Luis V.; Méndez, José A.; Larruquert, Juan I.
2016-07-01
Sum rules are a useful tool to evaluate the global consistency of a set of optical constants. We present a procedure to spectrally tune sum rules to evaluate the local consistency of optical constants. It enables enhancing the weight of a desired spectral range within the sum-rule integral. The procedure consists in multiplying the complex refractive index with an adapted function, which is named window function. Window functions are constructed through integration of Lorentz oscillators. The asymptotic decay of these window functions enables the derivation of a multiplicity of sum rules akin to the inertial sum rule, along with one modified version of f-sum rule. This multiplicity of sum rules combined with the free selection of the photon energy range provides a double way to tune the spectral contribution within the sum rule. Window functions were applied to reported data of SrF2 and of Al films in order to check data consistency over the spectrum. The use of window functions shows that the optical constants of SrF2 are consistent in a broad spectrum. Regarding Al, some spectral ranges are seen to present a lower consistency, even though the standard sum rules with no window function did not detect inconsistencies. Hence window functions are expected to be a helpful tool to evaluate the local consistency of optical constants.
On unit root formulas for toric exponential sums
Adolphson, Alan
2010-01-01
Starting from a classical generating series for Bessel functions due to Schlomilch, we use Dwork's relative dual theory to broadly generalize unit-root results of Dwork on Kloosterman sums and Sperber on hyperkloosterman sums. In particular, we express the (unique) p-adic unit root of an arbitrary exponential sum on the torus in terms of special values of the p-adic analytic continuation of a ratio of A-hypergeometric functions. In contrast with the earlier works, we use noncohomological methods and obtain results that are valid for arbitrary exponential sums without any hypothesis of nondegeneracy.
Ion cumulation by conical cathode electrolysis.
Grishin, V G
2002-01-01
Results of solid-state sodium stearate electrolysis with conical and cylindrical cathodes is presented here. Both electric measurement and conical samples destruction can be explained if a stress developing inside the conical sample is much bigger than in the cylindrical case and there is its unlimited amplification along cone slopes. OTHER KEYWORDS: ion, current, solid, symmetry, cumulation, polarization, depolarization, ionic conductor,superionic conductor, ice, crystal, strain, V-center, V-centre, doped crystal, interstitial impurity, intrinsic color center, high pressure technology, Bridgman, anvil, experiment, crowdion, dielectric, proton, layer, defect, lattice, dynamics, electromigration, mobility, muon catalysis, concentration, doping, dopant, conductivity, pycnonuclear reaction, permittivity, dielectric constant, point defects, interstitials, polarizability, imperfection, defect centers, glass, epitaxy, sodium hydroxide, metallic substrate, crystallization, point, tip, susceptibility, ferroelectric, ...
[Cumulative trauma disorders: work or professional disease?].
de Carvalho, Marcus Vitor Diniz; Cavalcanti, Francisco Ivo Dantas; Soriano, Evelyne Pessoa; de Miranda, Hênio Ferreira
2009-06-01
This study aimed at reviewing the Brazilian legislation applied to occupational health. It refers to the diseases embodied in the Repetition Strain Injury (RSI) and Cumulative Trauma Disorders (CTD) regarded as work or professional diseases. This analysis allowed to perform the historical evolution of legislation concerning the issue, noting that the state of the art of regulation on RSI-CTD is anchored in specific regulation present in the Normative Instruction 98/2003, that establishes the diagnostic criteria and classification of RSI-CTD. It was concluded that according to the existing legislation in Brazil, the pathologies related to RSI-CTD are considered as work diseases and their legal effects are similar to the work-related accidents.
Energy Technology Data Exchange (ETDEWEB)
El Ammouri, F.; Plessier, R.; Till, M.; Marie, B.; Djavdan, E. [Air Liquide Centre de Recherche Claude Delorme, 78 - Jouy-en-Josas (France)
1996-12-31
Coupled reactive fluid dynamics and radiation calculations are performed in air and oxy-fuel furnaces using two gas radiative property models. The first one is the weighted sum of gray gases model (WSGG) and the second one is the correlated-k (CK) method which is a spectral model based on the cumulative distribution function of the absorption coefficient inside a narrow band. The WSGG model, generally used in industrial configurations, is less time consuming than the CK model. However it is found that it over-predicts radiative fluxes by about 12 % in industrial furnaces. (authors) 27 refs.
Defining competence in obstetric epidural anaesthesia for inexperienced trainees.
Drake, E J; Coghill, J; Sneyd, J R
2015-06-01
Cumulative sum (CUSUM) analysis has been used for assessing competence of trainees learning new technical skills. One of its disadvantages is the required definition of acceptable and unacceptable success rates. We therefore monitored the development of competence amongst trainees new to obstetric epidural anaesthesia in a large public hospital. Obstetric epidural data were collected prospectively between January 1996 and December 2011. Success rates for inexperienced trainees were calculated retrospectively for (1) the whole database, (2) for each consecutive attempt and (3) each trainee's individual overall success rate. Acceptable and unacceptable success rates were defined and CUSUM graphs generated for each trainee. Competence was assessed for each trainee and the number of attempts to reach competence recorded. Mean (sd) success rate for all inexperienced trainees was 76.8 (0.1%), range 63-90%. Consecutive attempt success rate produced a learning curve with a mean success rate commencing at 58% on attempt 1. After attempt 10 the attempt number had no effect on subsequent success rates. From these results, the acceptable and unacceptable success rates were set at 65 and 55% respectively. CUSUM graphs demonstrated 76 out of 81 trainees competent after a mean of 46 (22) attempts. CUSUM is useful for assessing trainee epidural competence. Trainees require approximately 50 attempts, as defined by CUSUM, to reach competence. © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
A note on the moments of Kloosterman sums
Xi, Ping
2011-01-01
In this note, we deduce an asymptotic formula for even power moments of Kloosterman sums based on the important work of N. M. Katz on Kloosterman sheaves. In a similar manner, we can also obtain an upper bound for odd power moments. Moreover, we shall give an asymptotic formula for odd power moments of absolute Kloosterman sums.
Partial sums of arithmetical functions with absolutely convergent Ramanujan expansions
Indian Academy of Sciences (India)
BISWAJYOTI SAHA
2016-08-01
For an arithmetical function $f$ with absolutely convergent Ramanujan expansion, we derive an asymptotic formula for the $\\sum_{n\\leq N}$ f(n)$ with explicit error term. As a corollary we obtain new results about sum-of-divisors functions and Jordan’s totient functions.
Almost Sure Central Limit Theorems for Heavily Trimmed Sums
Institute of Scientific and Technical Information of China (English)
Fang WANG; Shi Hong CHENG
2004-01-01
We obtain an almost sure central limit theorem (ASCLT) for heavily trimmed sums. We also prove a function-typed ASCLT under the same conditions that assure measurable functions to satisfy the ASCLT for the partial sums of i.i.d. random variables with EX1 = 0, EX12 = 1.
On Sum--Connectivity Index of Bicyclic Graphs
Du, Zhibin
2009-01-01
We determine the minimum sum--connectivity index of bicyclic graphs with $n$ vertices and matching number $m$, where $2\\le m\\le \\lfloor\\frac{n}{2}\\rfloor$, the minimum and the second minimum, as well as the maximum and the second maximum sum--connectivity indices of bicyclic graphs with $n\\ge 5$ vertices. The extremal graphs are characterized.
Analytic and algorithmic aspects of generalized harmonic sums and polylogarithms
Energy Technology Data Exchange (ETDEWEB)
Ablinger, Jakob; Schneider, Carsten [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation; Bluemlein, Johannes [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)
2013-01-15
In recent three-loop calculations of massive Feynman integrals within Quantum Chromodynamics (QCD) and, e.g., in recent combinatorial problems the so-called generalized harmonic sums (in short S-sums) arise. They are characterized by rational (or real) numerator weights also different from {+-}1. In this article we explore the algorithmic and analytic properties of these sums systematically. We work out the Mellin and inverse Mellin transform which connects the sums under consideration with the associated Poincare iterated integrals, also called generalized harmonic polylogarithms. In this regard, we obtain explicit analytic continuations by means of asymptotic expansions of the S-sums which started to occur frequently in current QCD calculations. In addition, we derive algebraic and structural relations, like differentiation w.r.t. the external summation index and different multi-argument relations, for the compactification of S-sum expressions. Finally, we calculate algebraic relations for infinite S-sums, or equivalently for generalized harmonic polylogarithms evaluated at special values. The corresponding algorithms and relations are encoded in the computer algebra package HarmonicSums.
Chain hexagonal cacti with the extremal eccentric distance sum.
Qu, Hui; Yu, Guihai
2014-01-01
Eccentric distance sum (EDS), which can predict biological and physical properties, is a topological index based on the eccentricity of a graph. In this paper we characterize the chain hexagonal cactus with the minimal and the maximal eccentric distance sum among all chain hexagonal cacti of length n, respectively. Moreover, we present exact formulas for EDS of two types of hexagonal cacti.
Finding Sums for an Infinite Class of Alternating Series
Chen, Zhibo; Wei, Sheng; Xiao, Xuerong
2012-01-01
Calculus II students know that many alternating series are convergent by the Alternating Series Test. However, they know few alternating series (except geometric series and some trivial ones) for which they can find the sum. In this article, we present a method that enables the students to find sums for infinitely many alternating series in the…
College Sports: The Mystery of the Zero-Sum Game
Getz, Malcolm; Siegfried, John J.
2012-01-01
In recent years, when a university may earn well over $10 million per year from fees for sports-broadcast rights, half of the teams still lose. Collegiate athletic competition is a zero sum game: The number of winners equals the number of losers. So why do universities spend growing sums of scarce resources on an activity when the odds of winning…
Integrals of $K$ and $E$ from Lattice Sums
J. G. WAN; Zucker, I. J.
2014-01-01
We give closed form evaluations for many families of integrals, whose integrands contain algebraic functions of the complete elliptic integrals $K$ and $E$. Our methods exploit the rich structures connecting complete elliptic integrals, Jacobi theta functions, lattice sums, and Eisenstein series. Various examples are given, and along the way new (including 10-dimensional) lattice sum evaluations are produced.
Octet magnetic Moments and their sum rules in statistical model
Batra, M
2013-01-01
The statistical model is implemented to find the magnetic moments of all octet baryons. The well-known sum rules like GMO and CG sum rules has been checked in order to check the consistency of our approach. The small discrepancy between the results suggests the importance of breaking in SU(3) symmetry.
Radiative Corrections to the Sum Rule of Lepton Flavor Mixing
Zhang, Jue
2016-01-01
The simple correlation among three lepton flavor mixing angles $(\\theta^{}_{12}, \\theta^{}_{13}, \\theta^{}_{23})$ and the leptonic Dirac CP-violating phase $\\delta$ is conventionally called a sum rule of lepton flavor mixing, which may be derived from a class of neutrino mass models with flavor symmetries. In this paper, we consider the sum rule $\\theta^{}_{12} \\approx \\theta^{\
Generating matrix and sums of Fibonacci and Pell sequences
Ho, C. K.; Woon, H. S.; Chong, Chin-Yoon
2014-07-01
In this paper, we study the Fibonacci sequence and Pell sequence and developed generating matrices for them. First we proved two results on the even sum of the Fibonacci sequence and the Pell sequence, using the generating matrix approach. We then deduce the odd sums, some identities and recursive formulas for these two sequences.
Faraday effect revisited: sum rules and convergence issues
DEFF Research Database (Denmark)
Cornean, Horia; Nenciu, Gheorghe
2010-01-01
This is the third paper of a series revisiting the Faraday effect. The question of the absolute convergence of the sums over the band indices entering the Verdet constant is considered. In general, sum rules and traces per unit volume play an important role in solid-state physics, and they give...
GRASP with Path Relinking for the SumCut Problem
Directory of Open Access Journals (Sweden)
Jesús Sánchez-Oro
2012-01-01
Full Text Available This paper proposes a GRASP algorithm combined with Path Relinking to solve the SumCut minimization problem. In the SumCut problem one is given a graph with n nodes and must label the nodes in a way that each node receives a unique label from the set{1,2,…,n}, in order to minimize the sum cut of the generated solution. The SumCut problem is really important in archeology (in seriation tasks and in genetics, helping in the Human Genome Project. This problem is equivalent to the Profile problem, because a solution for SumCut is reversal solution for Profile problem. Experimental results show that the GRASP and Path Relinking methods presented outperform in terms of average percentage deviation the results from the State of the Art using shorter CPU time.
Harmonic sums, polylogarithms, special numbers, and their generalizations
Energy Technology Data Exchange (ETDEWEB)
Ablinger, Jakob [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation; Bluemlein, Johannes [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)
2013-04-15
In these introductory lectures we discuss classes of presently known nested sums, associated iterated integrals, and special constants which hierarchically appear in the evaluation of massless and massive Feynman diagrams at higher loops. These quantities are elements of stuffle and shuffle algebras implying algebraic relations being widely independent of the special quantities considered. They are supplemented by structural relations. The generalizations are given in terms of generalized harmonic sums, (generalized) cyclotomic sums, and sums containing in addition binomial and inverse-binomial weights. To all these quantities iterated integrals and special numbers are associated. We also discuss the analytic continuation of nested sums of different kind to complex values of the external summation bound N.
Harmonic Sums, Polylogarithms, Special Numbers, and their Generalizations
Ablinger, Jakob
2013-01-01
In these introductory lectures we discuss classes of presently known nested sums, associated iterated integrals, and special constants which hierarchically appear in the evaluation of massless and massive Feynman diagrams at higher loops. These quantities are elements of stuffle and shuffle algebras implying algebraic relations being widely independent of the special quantities considered. They are supplemented by structural relations. The generalizations are given in terms of generalized harmonic sums, (generalized) cyclotomic sums, and sums containing in addition binomial and inverse-binomial weights. To all these quantities iterated integrals and special numbers are associated. We also discuss the analytic continuation of nested sums of different kind to complex values of the external summation bound N.
Evaluation of the multi-sums for large scale problems
Energy Technology Data Exchange (ETDEWEB)
Bluemlein, J.; Hasselhuhn, A. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation
2012-02-15
A big class of Feynman integrals, in particular, the coefficients of their Laurent series expansion w.r.t. the dimension parameter {epsilon} can be transformed to multi-sums over hypergeometric terms and harmonic sums. In this article, we present a general summation method based on difference fields that simplifies these multi--sums by transforming them from inside to outside to representations in terms of indefinite nested sums and products. In particular, we present techniques that assist in the task to simplify huge expressions of such multi-sums in a completely automatic fashion. The ideas are illustrated on new calculations coming from 3-loop topologies of gluonic massive operator matrix elements containing two fermion lines, which contribute to the transition matrix elements in the variable flavor scheme. (orig.)
Long and Short Term Cumulative Structural Priming Effects.
Kaschak, Michael P; Kutta, Timothy J; Coyle, Jacqueline M
We present six experiments that examine cumulative structural priming effects (i.e., structural priming effects that accumulate across many utterances). Of particular interest is whether (1) cumulative priming effects transfer across language production tasks and (2) the transfer of cumulative priming effects across tasks persists over the course of a week. Our data suggest that cumulative structural priming effects do transfer across language production tasks (e.g., from written stem completion to picture description, and from picture description to written stem completion), but only when both tasks are presented in the same experimental session. When cumulative priming effects are established in one task, and the second (changed) task is not presented until a week later, the cumulative priming effects are not observed.
Why Veterinary Medical Educators Should Embrace Cumulative Final Exams.
Royal, Kenneth D
2017-01-03
The topic of cumulative final examinations often elicits polarizing opinions from veterinary medical educators. While some faculty prefer cumulative finals, there are many who perceive these types of examinations as problematic. Specifically, faculty often cite cumulative examinations are more likely to cause students' greater stress, which may in turn result in negative student evaluations of teaching. Cumulative finals also restrict the number of items one may present to students on most recent material. While these cited disadvantages may have some merit, the advantages of cumulative examinations far exceed the disadvantages. The purpose of this article is to discuss the advantages of cumulative examinations with respect to learning evidence, grade/score validity, fairness issues, and implications for academic policy.
Lim, Kim-Hui,; Har, Wai-Mun
2008-01-01
The lack of academic and thinking culture is getting more worried and becomes a major challenge to our academia society this 21st century. Few directions that move academia from "cogito ergo sum" to "consumo ergo sum" are actually leading us to "the end of academia". Those directions are: (1) the death of dialectic;…
Directory of Open Access Journals (Sweden)
Romer C. Castillo
2015-11-01
Full Text Available Factoriangular numbers resulted from adding corresponding factorials and triangular numbers. If Ftn is the nth factoriangular number, n! is the factorial of n and Tn is the nth triangular number, then Ftn = n! + Tn. In this study, interesting results on the representations of factoriangular number as sum of two triangular numbers and as sum of two squares are presented.
Analysis of experimental data on correlations between cumulative particles
Energy Technology Data Exchange (ETDEWEB)
Vlasov, A.V.; Doroshkevich, E.A.; Leksin, G.A. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation)] [and others
1995-04-01
Experimental data on correlations between cumulative particles are analyzed. A space-time and energy-transfer pattern of hadron-nucleus interaction based on both correlation data and data on the inclusive spectra of cumulative particles is considered. A new variable that is convenient for describing the production of cumulative particles is proposed using the concept of symmetry between the one-particle and multiparticle distributions. 32 refs., 9 figs., 1 tab.
Institute of Scientific and Technical Information of China (English)
娄聃; 常安定; 荀海潞; 孙丽芹
2015-01-01
经典的休哈特控制图对质量特征值的均值波动检出力较弱.采用均值-极差控制图控制印刷电路板锡浆厚度在短期内往往很难发现印刷锡浆厚度偏差的偏移,导致印刷锡浆厚度偏差调整不及时.为了提高检出力,采用累积和控制图(CUSUM)来控制印刷锡浆厚度偏差的变化,改进了印刷锡浆厚度偏差调整方式,在保证质量的同时降低了生产成本.
Analysis of Memory Codes and Cumulative Rehearsal in Observational Learning
Bandura, Albert; And Others
1974-01-01
The present study examined the influence of memory codes varying in meaningfulness and retrievability and cumulative rehearsal on retention of observationally learned responses over increasing temporal intervals. (Editor)
Continuously Cumulating Meta-Analysis and Replicability.
Braver, Sanford L; Thoemmes, Felix J; Rosenthal, Robert
2014-05-01
The current crisis in scientific psychology about whether our findings are irreproducible was presaged years ago by Tversky and Kahneman (1971), who noted that even sophisticated researchers believe in the fallacious Law of Small Numbers-erroneous intuitions about how imprecisely sample data reflect population phenomena. Combined with the low power of most current work, this often leads to the use of misleading criteria about whether an effect has replicated. Rosenthal (1990) suggested more appropriate criteria, here labeled the continuously cumulating meta-analytic (CCMA) approach. For example, a CCMA analysis on a replication attempt that does not reach significance might nonetheless provide more, not less, evidence that the effect is real. Alternatively, measures of heterogeneity might show that two studies that differ in whether they are significant might have only trivially different effect sizes. We present a nontechnical introduction to the CCMA framework (referencing relevant software), and then explain how it can be used to address aspects of replicability or more generally to assess quantitative evidence from numerous studies. We then present some examples and simulation results using the CCMA approach that show how the combination of evidence can yield improved results over the consideration of single studies.
Harmonic sums and polylogarithms generated by cyclotomic polynomials
Energy Technology Data Exchange (ETDEWEB)
Ablinger, Jakob; Schneider, Carsten [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation; Bluemlein, Johannes [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)
2011-05-15
The computation of Feynman integrals in massive higher order perturbative calculations in renormalizable Quantum Field Theories requires extensions of multiply nested harmonic sums, which can be generated as real representations by Mellin transforms of Poincare-iterated integrals including denominators of higher cyclotomic polynomials. We derive the cyclotomic harmonic polylogarithms and harmonic sums and study their algebraic and structural relations. The analytic continuation of cyclotomic harmonic sums to complex values of N is performed using analytic representations. We also consider special values of the cyclotomic harmonic polylogarithms at argument x=1, resp., for the cyclotomic harmonic sums at N{yields}{infinity}, which are related to colored multiple zeta values, deriving various of their relations, based on the stuffle and shuffle algebras and three multiple argument relations. We also consider infinite generalized nested harmonic sums at roots of unity which are related to the infinite cyclotomic harmonic sums. Basis representations are derived for weight w=1,2 sums up to cyclotomy l=20. (orig.)
Minkowski sum of HV-polytopes in Rn
Delos, Vincent
2014-01-01
Minkowski sums cover a wide range of applications in many different fields like algebra, morphing, robotics, mechanical CAD/CAM systems ... This paper deals with sums of polytopes in a n dimensional space provided that both H-representation and V-representation are available i.e. the polytopes are described by both their half-spaces and vertices. The first method uses the polytope normal fans and relies on the ability to intersect dual polyhedral cones. Then we introduce another way of considering Minkowski sums of polytopes based on the primal polyhedral cones attached to each vertex.
Evolution of sum-chirp in polarization multiplexed communication system
Institute of Scientific and Technical Information of China (English)
Wang Jing; Wang Zhen-Li
2004-01-01
The evolution of sum-chirp for an initially chirped Gaussian pulse is studied in the polarization multiplexed communication system, with fibre attenuation considered. The sum-chirp is found to have the character of saturation.Its value appears different along the two different polarization axes, determined by the incidence polarization angle. We also find that sum-chirp is dominated by the initial chirp at a short distance, and by the cross-phase modulation effect at long distance. And it is influenced apparently by a wavevector mismatch parameter below 10 ps/km. Further, its saturation results from the effective distance determined by fibre attenuation.
Neutrino mass sum rules and symmetries of the mass matrix
Energy Technology Data Exchange (ETDEWEB)
Gehrlein, Julia [Karlsruhe Institute of Technology, Institut fuer Theoretische Teilchenphysik, Karlsruhe (Germany); Universidad Autonoma de Madrid, Departamento de Fisica Teorica, Madrid (Spain); Instituto de Fisica Teorica UAM/CSIC, Madrid (Spain); Spinrath, Martin [Karlsruhe Institute of Technology, Institut fuer Theoretische Teilchenphysik, Karlsruhe (Germany); National Center for Theoretical Sciences, Physics Division, Hsinchu (China)
2017-05-15
Neutrino mass sum rules have recently gained again more attention as a powerful tool to discriminate and test various flavour models in the near future. A related question which has not yet been discussed fully satisfactorily was the origin of these sum rules and if they are related to any residual or accidental symmetry. We will address this open issue here systematically and find previous statements confirmed. Namely, the sum rules are not related to any enhanced symmetry of the Lagrangian after family symmetry breaking but they are simply the result of a reduction of free parameters due to skillful model building. (orig.)
Sums of magnetic eigenvalues are maximal on rotationally symmetric domains
Laugesen, Richard S; Roy, Arindam
2011-01-01
The sum of the first n energy levels of the planar Laplacian with constant magnetic field of given total flux is shown to be maximal among triangles for the equilateral triangle, under normalization of the ratio (moment of inertia)/(area)^3 on the domain. The result holds for both Dirichlet and Neumann boundary conditions, with an analogue for Robin (or de Gennes) boundary conditions too. The square similarly maximizes the eigenvalue sum among parallelograms, and the disk maximizes among ellipses. More generally, a domain with rotational symmetry will maximize the magnetic eigenvalue sum among all linear images of that domain. These results are new even for the ground state energy (n=1).
Exact Stochastic Unraveling of an Optical Coherence Dynamics by Cumulant Expansion
Olsina, Jan; Kreisbeck, Christoph; Mancal, Tomas
2013-01-01
A numerically exact Monte Carlo scheme for calculation of open quantum system dynamics is proposed and implemented. Time evolution of an optically excited Frenkel exciton dimer representing a molecular aggregate interacting with its environment is investigated. The method is based on a Monte-Carlo summation of a perturbation expansion with respect to the resonance coupling between the excited states of the molecules which is mapped on a sum over trajectories in Liouville space of the system. The trajectories are weighted by a complex decoherence factors based on second cumulant expansion of the environmental evolution. The method can be used with an arbitrary environment characterized by a general correlation function, and it is exact for Gaussian environments. We calculate the evolution of the optical coherences and linear absorption spectrum, and compare them with the predictions of the standard simulation methods.
Cumulative Effect of Depression on Dementia Risk
Directory of Open Access Journals (Sweden)
J. Olazarán
2013-01-01
Full Text Available Objective. To analyze a potential cumulative effect of life-time depression on dementia and Alzheimer’s disease (AD, with control of vascular factors (VFs. Methods. This study was a subanalysis of the Neurological Disorders in Central Spain (NEDICES study. Past and present depression, VFs, dementia status, and dementia due to AD were documented at study inception. Dementia status was also documented after three years. Four groups were created according to baseline data: never depression (nD, past depression (pD, present depression (prD, and present and past depression (prpD. Logistic regression was used. Results. Data of 1,807 subjects were investigated at baseline (mean age 74.3, 59.3% women, and 1,376 (81.6% subjects were evaluated after three years. The prevalence of dementia at baseline was 6.7%, and dementia incidence was 6.3%. An effect of depression was observed on dementia prevalence (OR [CI 95%] 1.84 [1.01–3.35] for prD and 2.73 [1.08–6.87] for prpD, and on dementia due to AD (OR 1.98 [0.98–3.99] for prD and OR 3.98 [1.48–10.71] for prpD (fully adjusted models, nD as reference. Depression did not influence dementia incidence. Conclusions. Present depression and, particularly, present and past depression are associated with dementia at old age. Multiple mechanisms, including toxic effect of depression on hippocampal neurons, plausibly explain these associations.
Institute of Scientific and Technical Information of China (English)
王海涛; 陈友明; 陈永康; 秦建英
2012-01-01
Cumulative sum (CUSUM) control charts are constructed under the assumption that the observations taken from the process of interest are independent over time. However, the observations in many industrial cases are actually correlated. Serial correlation of observations will result in poor performance of control charts. The effect of serial correlation on the performance of control charts is analyzed through mathematical analysis method. Positive serial correlation decreases the average run length (ARL) of CUSUM control chart, resulting in too many false alarms. Negative serial correlation increases the ARL of CUSUM control chart, which possibly results in missing faults. In addition, a fault detection method for autocorrelated processes is presented by using residual-based CUSUM control chart. The residuals between the process error and its predication are generated using autoregressive time-series models. Then, CUSUM control charts are used to monitor the residuals which are statistically independent. The residual-based CUSUM control chart can improve the accuracy of fault detection through eliminating the effects of serial correlation on the performance of control charts. Some case studies show that the residual-based CUSUM control chart is an effective tool in detecting faults of autocorrelated processes, and the fault detection method has good robustness and high accuracy rate.%由于累积和控制图(cumulative sum,简称CUSUM)算法应用的基本假设是从过程得到的观测值彼此独立,而工业过程通常是自相关过程,数据自相关性会影响CUSUM控制图的性能.针对这一问题,利用数学推理的方法分析了数据自相关性对CUSUM控制图性能的不利影响,正自相关会使CUSUM控制图的平均运行长度变短,可能引起假警报；负自相关会使CUSUM控制图的平均运行长度变长,可能造成故障漏报.在此基础上,提出用残差CUSUM控制图来检测自相关过程中的故障,运用时间序
The Nonlinearity of Sum and Product for Boolean Functions
Directory of Open Access Journals (Sweden)
Huang Jinglian
2016-01-01
Full Text Available In this paper, we study the relationship between the nonlinearity of Boolean function and the nonlinearity of the sum and product of Boolean function, while derivative and e-derivative are used to study the problem further. We obtain that the sum of two functions’ nonlinearity is not less than the nonlinearity of the sum of two functions. The relationship between the nonlinearity of function and the nonlinearity of the sum and product of two functions are also obtained. Furthermore, we also get the relationship between the nonlinearity of the product of functions, and the derivative and e-derivative of function. Moreover, we also deduced some important applications on the basis of the above work.
The Sum and Difference of Two Lognormal Random Variables
Directory of Open Access Journals (Sweden)
C. F. Lo
2012-01-01
Full Text Available We have presented a new unified approach to model the dynamics of both the sum and difference of two correlated lognormal stochastic variables. By the Lie-Trotter operator splitting method, both the sum and difference are shown to follow a shifted lognormal stochastic process, and approximate probability distributions are determined in closed form. Illustrative numerical examples are presented to demonstrate the validity and accuracy of these approximate distributions. In terms of the approximate probability distributions, we have also obtained an analytical series expansion of the exact solutions, which can allow us to improve the approximation in a systematic manner. Moreover, we believe that this new approach can be extended to study both (1 the algebraic sum of N lognormals, and (2 the sum and difference of other correlated stochastic processes, for example, two correlated CEV processes, two correlated CIR processes, and two correlated lognormal processes with mean-reversion.
Compton scattering from nuclei and photo-absorption sum rules
Gorchtein, Mikhail; Hobbs, Timothy; Londergan, J. Timothy; Szczepaniak, Adam P.
2011-12-01
We revisit the photo-absorption sum rule for real Compton scattering from the proton and from nuclear targets. In analogy with the Thomas-Reiche-Kuhn sum rule appropriate at low energies, we propose a new “constituent quark model” sum rule that relates the integrated strength of hadronic resonances to the scattering amplitude on constituent quarks. We study the constituent quark model sum rule for several nuclear targets. In addition, we extract the α=0 pole contribution for both proton and nuclei. Using the modern high-energy proton data, we find that the α=0 pole contribution differs significantly from the Thomson term, in contrast with the original findings by Damashek and Gilman.
Compton Scattering and Photo-absorption Sum Rules on Nuclei
Gorshteyn, Mikhail; Hobbs, Timothy; Londergan, J. Timothy; Szczepaniak, Adam P.
2012-03-01
We revisit the photo-absorption sum rule for real Compton scattering from the proton and from nuclear targets. In analogy with the Thomas-Reiche-Kuhn sum rule appropriate at low energies, we propose a new ``constituent quark model'' sum rule that relates the integrated strength of hadronic resonances to the scattering amplitude on constituent quarks. We study the constituent quark model sum rule for several nuclear targets. In addition we extract the J=0 pole contribution for both proton and nuclei. Using the modern high energy proton data we find that the J=0 pole contribution differs significantly from the Thomson term, in contrast with the original findings by Damashek and Gilman. We discuss phenomenological implications of this new result.
Limiting Behavior of Weighted Sums of NOD Random Variables
Institute of Scientific and Technical Information of China (English)
De Hua QIU; Ping Yan CHEN
2011-01-01
The strong laws of large numbers and laws of the single logarithm for weighted sums of NOD random variables are established.The results presented generalize the corresponding results of Chen and Gan [5]in independent sequence case.
Sublinear Time Approximate Sum via Uniform Random Sampling
Fu, Bin; Peng, Zhiyong
2012-01-01
We investigate the approximation for computing the sum $a_1+...+a_n$ with an input of a list of nonnegative elements $a_1,..., a_n$. If all elements are in the range $[0,1]$, there is a randomized algorithm that can compute an $(1+\\epsilon)$-approximation for the sum problem in time ${O({n(\\log\\log n)\\over\\sum_{i=1}^n a_i})}$, where $\\epsilon$ is a constant in $(0,1)$. Our randomized algorithm is based on the uniform random sampling, which selects one element with equal probability from the input list each time. We also prove a lower bound $\\Omega({n\\over \\sum_{i=1}^n a_i})$, which almost matches the upper bound, for this problem.
Structure Function Sum rules for Systems with Large Scattering Lengths
Goldberger, Walter D
2010-01-01
We use a dispersion relation in conjunction with the operator product expansion (OPE) to derive model independent sum rules for the dynamic structure functions of systems with large scattering lengths. We present an explicit sum rule for the structure functions that control the density and spin response of the many-body ground state. Our methods are general, and apply to either fermions or bosons which interact through two-body contact interactions with large scattering lengths. By employing a Borel transform of the OPE, the relevant integrals are weighted towards infrared frequencies, thus allowing for greater overlap low energy data. Similar sum rules can be derived for other response functions. The sum rules can be used to extract the contact parameter introduced by Tan, including universality violating corrections at finite scattering lengths.
A Framework for Treating Cumulative Trauma with Art Therapy
Naff, Kristina
2014-01-01
Cumulative trauma is relatively undocumented in art therapy practice, although there is growing evidence that art therapy provides distinct benefits for resolving various traumas. This qualitative study proposes an art therapy treatment framework for cumulative trauma derived from semi-structured interviews with three art therapists and artistic…
Cumulative Effects of Human Activities on Marine Mammal Populations
2015-09-30
1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Cumulative Effects of Human Activities on Marine Mammal ...marine mammals . OBJECTIVES The National Academies of Sciences, Engineering, and Medicine has convened a volunteer committee that will...Review the present scientific understanding of cumulative effects of anthropogenic stressors on marine mammals with a focus on anthropogenic sound
A Framework for Treating Cumulative Trauma with Art Therapy
Naff, Kristina
2014-01-01
Cumulative trauma is relatively undocumented in art therapy practice, although there is growing evidence that art therapy provides distinct benefits for resolving various traumas. This qualitative study proposes an art therapy treatment framework for cumulative trauma derived from semi-structured interviews with three art therapists and artistic…
Cumulative Estrogen Exposure and Prospective Memory in Older Women
Hesson, Jacqueline
2012-01-01
This study looked at cumulative lifetime estrogen exposure, as estimated with a mathematical index (Index of Cumulative Estrogen Exposure (ICEE)) that included variables (length of time on estrogen therapy, age at menarche and menopause, postmenopausal body mass index, time since menopause, nulliparity and duration of breastfeeding) known to…
Lattice energy sum rules and the trace anomaly
Rothe, Heinz J.
1995-01-01
We show that the additional contribution to the Michael lattice energy sum rule for the static quark-antiquark potential, pointed out recently, can be identified with the contribution to the field energy arising from the trace anomaly of the energy momentum tensor. We also exlicitely exhibit the anomalous contribution to the field energy in the sum rule for the glueball mass obtained recently by Michael.
Magnetic Dipole Sum Rules for Odd-Mass Nuclei
Energy Technology Data Exchange (ETDEWEB)
Ginocchio, J.N.; Leviatan, A. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Leviatan, A. [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel); Ginocchio, J.N.; Leviatan, A. [European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT), I-38050 Villazano, Trento (Italy)
1997-08-01
Sum rules for the total- and scissors-mode M1 strength in odd-A nuclei are derived within the single-j interacting boson-fermion model. We discuss the physical content and geometric interpretation of these sum rules and apply them to {sup 167}Er and {sup 161}Dy. We find consistency with the former measurements but not with the latter. {copyright} {ital 1997 } {ital The American Physical Society}
Induction and Analogy in a Problem of Finite Sums
Zielinski, Ryan
2016-01-01
What is a general expression for the sum of the first n integers, each raised to the mth power, where m is a positive integer? Answering this question will be the aim of the paper....We will take the unorthodox approach of presenting the material from the point of view of someone who is trying to solve the problem himself. Keywords: analogy, Johann Faulhaber, finite sums, heuristics, inductive reasoning, number theory, George Polya, problem solving, teaching of mathematics
Unidirectional ring-laser operation using sum-frequency mixing
DEFF Research Database (Denmark)
Tidemand-Lichtenberg, Peter; Cheng, Haynes Pak Hay; Pedersen, Christian
2010-01-01
A technique enforcing unidirectional operation of ring lasers is proposed and demonstrated. The approach relies on sum-frequency mixing between a single-pass laser and one of the two counterpropagating intracavity fields of the ring laser. Sum-frequency mixing introduces a parametric loss for the...... where lossless second-order nonlinear materials are available. Numerical modeling and experimental demonstration of parametric-induced unidirectional operation of a diode-pumped solid-state 1342 nm cw ring laser are presented....
QCD Sum Rules and Models for Generalized Parton Distributions
Energy Technology Data Exchange (ETDEWEB)
Anatoly Radyushkin
2004-10-01
I use QCD sum rule ideas to construct models for generalized parton distributions. To this end, the perturbative parts of QCD sum rules for the pion and nucleon electromagnetic form factors are interpreted in terms of GPDs and two models are discussed. One of them takes the double Borel transform at adjusted value of the Borel parameter as a model for nonforward parton densities, and another is based on the local duality relation. Possible ways of improving these Ansaetze are briefly discussed.
The quantum Ising model: finite sums and hyperbolic functions
Damski, Bogdan
2015-10-01
We derive exact closed-form expressions for several sums leading to hyperbolic functions and discuss their applicability for studies of finite-size Ising spin chains. We show how they immediately lead to closed-form expressions for both fidelity susceptibility characterizing the quantum critical point and the coefficients of the counterdiabatic Hamiltonian enabling arbitrarily quick adiabatic driving of the system. Our results generalize and extend the sums presented in the popular Gradshteyn and Ryzhik Table of Integrals, Series, and Products.
The quantum Ising model: finite sums and hyperbolic functions
Bogdan Damski
2015-01-01
We derive exact closed-form expressions for several sums leading to hyperbolic functions and discuss their applicability for studies of finite-size Ising spin chains. We show how they immediately lead to closed-form expressions for both fidelity susceptibility characterizing the quantum critical point and the coefficients of the counterdiabatic Hamiltonian enabling arbitrarily quick adiabatic driving of the system. Our results generalize and extend the sums presented in the popular Gradshteyn...
The Black Hole Interior and a Curious Sum Rule
Giveon, Amit; Troost, Jan
2013-01-01
We analyze the Euclidean geometry near non-extremal NS5-branes in string theory, including regions beyond the horizon and beyond the singularity of the black brane. The various regions have an exact description in string theory, in terms of cigar, trumpet and negative level minimal model conformal field theories. We study the worldsheet elliptic genera of these three superconformal theories, and show that their sum vanishes. We speculate on the significance of this curious sum rule for black hole physics.
The black hole interior and a curious sum rule
Energy Technology Data Exchange (ETDEWEB)
Giveon, Amit [Racah Institute of Physics, The Hebrew University,Jerusalem, 91904 (Israel); Itzhaki, Nissan [Physics Department, Tel-Aviv University,Ramat-Aviv, 69978 (Israel); Troost, Jan [Laboratoire de Physique Théorique,Unité Mixte du CRNS et de l’École Normale Supérieure,associée à l’Université Pierre et Marie Curie 6,UMR 8549 École Normale Supérieure,24 Rue Lhomond Paris 75005 (France)
2014-03-12
We analyze the Euclidean geometry near non-extremal NS5-branes in string theory, including regions beyond the horizon and beyond the singularity of the black brane. The various regions have an exact description in string theory, in terms of cigar, trumpet and negative level minimal model conformal field theories. We study the worldsheet elliptic genera of these three superconformal theories, and show that their sum vanishes. We speculate on the significance of this curious sum rule for black hole physics.
A Hybrid Continuous Max-Sum Algorithm for Decentralised Coordination
Voice, Thomas; Stranders, Ruben; Rogers, Alex; Jennings, Nick
2010-01-01
Recent advances in decentralised coordination of multiple agents have led to the proposal of the max-sum algorithm for solving distributed constraint optimisation problems (DCOPs). The max-sum algorithm is fully decentralised, converges to optimality for problems with acyclic constraint graphs and otherwise performs well in empirical studies. However, it requires agents to have discrete state spaces, which are of practical size to conduct repeated searches over. In contrast, there are decentr...
Complete Convergence for Weighted Sums of WOD Random Variables
Institute of Scientific and Technical Information of China (English)
ZHANG Ying; ZHANG Yu; SHEN Ai-ting
2016-01-01
In this article, we study the complete convergence for weighted sums of widely orthant dependent random variables. By using the exponential probability inequality, we establish a complete convergence result for weighted sums of widely orthant dependent ran-dom variables under mild conditions of weights and moments. The result obtained in the paper generalizes the corresponding ones for independent random variables and negatively dependent random variables.
Nuclear effects in deuteron and the Gottfried sum rule
Energy Technology Data Exchange (ETDEWEB)
Epele, L.N.; Sassot, R. (Lab. de Fisica Teorica, Univ. Nacional de La Plata (Argentina)); Fanchiotti, H. (Theory Div., CERN, Geneva (Switzerland)); Carcia Canal, C.A. (Lab. de Fisica Teorica, Univ. Nacional de La Plata (Argentina) Theory Div., CERN, Geneva (Switzerland))
1992-01-23
Recent NMC data on the ratio of the deep inelastic structure functions F{sub 2} per nucleon for deuterium relative to hydrogen are analysed in the context of the Gottfried sum rule. It is shown that the discrepancy between the Gottfried sum rule prediction and NMC data analysis may be interpreted as a nuclear effect in deuterium as it is suggested by several models. This fact, applied to nuclear-deuterium measured ratios, modifies the standard picture of nuclear effects. (orig.).
Lattice QCD results on cumulant ratios at freeze-out
Karsch, Frithjof
2016-01-01
Ratios of cumulants of net proton-number fluctuations measured by the STAR Collaboration show strong deviations from a skellam distribution, which should describe thermal properties of cumulant ratios, if proton-number fluctuations are generated in equilibrium and a hadron resonance gas (HRG) model would provide a suitable description of thermodynamics at the freeze-out temperature. We present some results on sixth order cumulants entering the calculation of the QCD equation of state at non-zero values of the baryon chemical potential (mu_B) and discuss limitations on the applicability of HRG thermodynamics deduced from a comparison between QCD and HRG model calculations of cumulants of conserved charge fluctuations. We show that basic features of the $\\mu_B$-dependence of skewness and kurtosis ratios of net proton-number fluctuations measured by the STAR Collaboration resemble those expected from a O(mu_B^2) QCD calculation of the corresponding net baryon-number cumulant ratios.
A new family of cumulative indexes for measuring scientific performance.
Directory of Open Access Journals (Sweden)
Marcin Kozak
Full Text Available In this paper we propose a new family of cumulative indexes for measuring scientific performance which can be applied to many metrics, including h index and its variants (here we apply it to the h index, h(2 index and Google Scholar's i10 index. These indexes follow the general principle of repeating the index calculation for the same publication set. Using bibliometric data and reviewer scores for accepted and rejected fellowship applicants we examine how valid the cumulative variant is compared to the original variant. These analyses showed that the cumulative indexes result in higher correlations with the reviewer scores than their original variants. Thus, the cumulative indexes better reflect the assessments by peers than the original variants and are useful extensions of the original indexes. In contrast to many other measures of scientific performance proposed up to now, the cumulative indexes seem not only to be effective, but they are also easy to understand and calculate.
Upper bounds on a two-term exponential sum
Institute of Scientific and Technical Information of China (English)
Todd; Cochrane
2001-01-01
［1］Davenport, H. , Heibronn, H., On an exponential sum, Proc. Lond. Math. Soc., 1936, 41(2): 449-453.［2］Hua, L. K., On exponential sums, Sci. Record (Peking) (N.S.), 1957, 1: 1-4.［3］Vaughan, R. C. , The Hardy-Littlewood Method, 2nd ed. , Cambridge Tracts in Math. , Cambridge: Cambridge Univ. Press, 1997, 125.［4］Weil, A., On some exponential sums, Proc. Nat. Acad. Sci. USA, 1948, 34: 204-207.［5］Cochrane, T., Zheng, Z., Pure and mixed exponential sums, Acta Arith. , 1999, 91(3): 249-278.［6］Chalk, J. H. H., On Hua's estimate for exponential sums, Mathematika, 1987, 34: 115-123.［7］Loh, W. K. A. , Hua's Lemma, Bull. Australian Math. Soc., 1994, 50(3): 451-458.［8］Ding, P., An improvement to Chalk's estimation of exponential sums, Acta Arith. , 1991, 59(2): 149-155.
Chiral corrections to the Adler-Weisberger sum rule
Beane, Silas R.; Klco, Natalie
2016-12-01
The Adler-Weisberger sum rule for the nucleon axial-vector charge, gA , offers a unique signature of chiral symmetry and its breaking in QCD. Its derivation relies on both algebraic aspects of chiral symmetry, which guarantee the convergence of the sum rule, and dynamical aspects of chiral symmetry breaking—as exploited using chiral perturbation theory—which allow the rigorous inclusion of explicit chiral symmetry breaking effects due to light-quark masses. The original derivations obtained the sum rule in the chiral limit and, without the benefit of chiral perturbation theory, made various attempts at extrapolating to nonvanishing pion masses. In this paper, the leading, universal, chiral corrections to the chiral-limit sum rule are obtained. Using PDG data, a recent parametrization of the pion-nucleon total cross sections in the resonance region given by the SAID group, as well as recent Roy-Steiner equation determinations of subthreshold amplitudes, threshold parameters, and correlated low-energy constants, the Adler-Weisberger sum rule is confronted with experimental data. With uncertainty estimates associated with the cross-section parametrization, the Goldberger-Treimann discrepancy, and the truncation of the sum rule at O (Mπ4) in the chiral expansion, this work finds gA=1.248 ±0.010 ±0.007 ±0.013 .
Cumulated insolation: a simple explanation of Milankovitch's forcing on climate changes
Directory of Open Access Journals (Sweden)
F. Marra
2013-10-01
Full Text Available The occurrence of the sudden melting of the ice sheets during the glacial terminations is explained in this paper as the consequence of the combined role of the minima and the maxima of mean summer insolation on the Northern Hemisphere, providing a new contribution to understand the mechanisms ruling glacial forcing. Indeed, no satisfactory answer has been provided so far to the question why one specific maximum, after a series of consecutive maxima of insolation, has the potentiality to trigger a deglaciation. The explanation proposed in this paper accounts for a pre-conditioning factor, represented by "mild" (warmer minimum, followed by a sufficiently warm maximum as the conditions that cause the end of a glacial cycle. These conditions are realized whenever the sum of the values of each consecutive minima and maxima ("cumulated insolation" on the curve of mean summer insolation at 65° N exceeds 742 Watt m−2. The comparison of the succession of these cumulated insolation values with the astronomically tuned Oxygen isotopes record provides a satisfactory match with the occurrence of all the glacial terminations in the last 800 ka.
A critique of the angular momentum sum rules and a new angular momentum sum rule
Bakker, B L G; Trueman, T L
2004-01-01
We show that the expressions in the literature for the tensorial structure of the hadronic matrix elements of the angular momentum operators J are incorrect. Given this disagreement with the published results, we have taken pains to derive the correct expressions in three different ways, two involving explicit physical wave packets and the third, totally independent, based upon the rotational properties of the state vectors. Surprisingly it turns out that the results are very sensitive to the type of relativistic spin state used to describe the motion of the particle i.e. whether a canonical (i.e. boost) state or a helicity state is utilized. We present results for the matrix elements of the angular momentum operators, valid in an arbitrary Lorentz frame, both for helicity states and canonical states. These results are relevant for the construction of angular momentum sum rules, relating the angular momentum of a nucleon to the spin and orbital angular momentum of its constituents. Moreover, we show that it i...
An analytical model for cumulative infiltration into a dual-permeability media
Peyrard, Xavier; Lassabatere, Laurent; Angulo-Jaramillo, Rafael; Simunek, Jiri
2010-05-01
Modeling of water infiltration into the vadose zone is important for better understanding of movement of water-transported contaminants. There is a great need to take into account the soil heterogeneity and, in particular, the presence of macropores or cracks that could generate preferential flow. Several mathematical models have been proposed to describe unsaturated flow through heterogeneous soils. The dual-permeability model assumes that flow is governed by Richards equation in both porous regions (matrix and fractures). Water can be exchanged between the two regions following a first-order rate law. A previous study showed that the influence of the hydraulic conductivity of the matrix/macropore interface had a little influence on cumulative infiltration at the soil surface. As a result, one could consider the surface infiltration for a specific case of no water exchange between the fracture and matrix regions (a case of zero interfacial hydraulic conductivity). In such a case, water infiltration can be considered to be the sum of the cumulative infiltrations into the matrix and the fractures. On the basis of analytical models for each sub domain (matrix and fractures), an analytical model is proposed for the entire dual-porosity system. A sensitivity analysis is performed to characterize the influence of several factors, such as the saturated hydraulic conductivity ratio, the water pressure scale parameter ratio, and the saturated volumetric water content scale ratio, on the total cumulative infiltration. Such an analysis greatly helps in quantifying the impact of macroporosity and fractures on water infiltration, which can be of great interest for hydrological models.
Indian Academy of Sciences (India)
MIN-T SAI LAI; SHIH-CHIH CHEN
2016-05-01
In this paper, a bivariate replacement policy (n, T) for a cumulative shock damage process is presented that included the concept of cumulative repair cost limit. The arrival shocks can be divided into two kinds of shocks. Each type-I shock causes a random amount of damage and these damages are additive. When the total damage exceeds a failure level, the system goes into serious failure. Type-II shock causes the system into minor failure and such a failure can be corrected by minimal repair. When a minor failure occurs, the repaircost will be evaluated and minimal repair is executed if the accumulated repair cost is less than a predetermined limit L. The system is replaced at scheduled time T, at n-th minor failure, or at serious failure. The long-term expected cost per unit time is derived using the expected costs as the optimality criterion. The minimum-cost policy is derived, and existence and uniqueness of the optimal n* and T* are proved. This bivariate optimal replacement policy (n, T) is showed to be better than the optimal T* and the optimal n* policy.
Longhi Games, Internal Reservoirs, and Cumulate Porosity
Morse, S. A.
2009-05-01
Fe in plagioclase at an early age, T-rollers (or not) on the Di-Trid boundary in Fo-Di-Sil, the mantle solidus, origins of anorthosites, esoteric uses of Schreinemakers rules and many more topics are all fresh and pleasant memories of John Longhi's prolific and creative work. The Fram-Longhi experimental effect of pressure on plagioclase partitioning with liquid in mafic rocks became essential to an understanding of multiphase Rayleigh fractionation of plagioclase in big layered intrusions. Only by using the pressure effect could I find a good equation through the data for the Kiglapait intrusion, and that result among others required the existence with probability 1.0 of an internal reservoir (Morse, JPet 2008). Knowledge of cumulate porosity is a crucial key to the understanding of layered igneous rocks. We seek both the initial (inverse packing fraction) and residual porosity to find the time and process path from sedimentation to solidification. In the Kiglapait Lower Zone we have a robust estimate of mean residual porosity from the modes of the excluded phases augite, oxides, sulfide, and apatite. To this we apply the maximum variance of plagioclase composition (the An range) to find an algorithm that extends through the Upper Zone and to other intrusions. Of great importance is that all these measurements were made in grain mounts concentrated from typically about 200 g of core or hand specimen, hence the represented sample volume is thousands of times greater than for a thin section. The resulting distribution and scatter of the An range is novel and remarkable. It is V-shaped in the logarithmic representation of stratigraphic height, running from about 20 mole % at both ends (base to top of the Layered Series) to near-zero at 99 PCS. The intercept of the porosity-An range relation gives An range = 3.5 % at zero residual porosity. Petrographic analysis reveals that for PCS less than 95 and greater than 99.9, the An range is intrinsic, i.e. pre-cumulus, for
A fast simulation method for the Log-normal sum distribution using a hazard rate twisting technique
Rached, Nadhir B.
2015-06-08
The probability density function of the sum of Log-normally distributed random variables (RVs) is a well-known challenging problem. For instance, an analytical closed-form expression of the Log-normal sum distribution does not exist and is still an open problem. A crude Monte Carlo (MC) simulation is of course an alternative approach. However, this technique is computationally expensive especially when dealing with rare events (i.e. events with very small probabilities). Importance Sampling (IS) is a method that improves the computational efficiency of MC simulations. In this paper, we develop an efficient IS method for the estimation of the Complementary Cumulative Distribution Function (CCDF) of the sum of independent and not identically distributed Log-normal RVs. This technique is based on constructing a sampling distribution via twisting the hazard rate of the original probability measure. Our main result is that the estimation of the CCDF is asymptotically optimal using the proposed IS hazard rate twisting technique. We also offer some selected simulation results illustrating the considerable computational gain of the IS method compared to the naive MC simulation approach.
Cumulative stress and autonomic dysregulation in a community sample.
Lampert, Rachel; Tuit, Keri; Hong, Kwang-Ik; Donovan, Theresa; Lee, Forrester; Sinha, Rajita
2016-05-01
Whether cumulative stress, including both chronic stress and adverse life events, is associated with decreased heart rate variability (HRV), a non-invasive measure of autonomic status which predicts poor cardiovascular outcomes, is unknown. Healthy community dwelling volunteers (N = 157, mean age 29 years) participated in the Cumulative Stress/Adversity Interview (CAI), a 140-item event interview measuring cumulative adversity including major life events, life trauma, recent life events and chronic stressors, and underwent 24-h ambulatory ECG monitoring. HRV was analyzed in the frequency domain and standard deviation of NN intervals (SDNN) calculated. Initial simple regression analyses revealed that total cumulative stress score, chronic stressors and cumulative adverse life events (CALE) were all inversely associated with ultra low-frequency (ULF), very low-frequency (VLF) and low-frequency (LF) power and SDNN (all p stress and chronic stress each was significantly associated with SDNN and ULF even after the highly significant contributions of age and sex, with no other covariates accounting for additional appreciable variance. For VLF and LF, both total cumulative stress and chronic stress significantly contributed to the variance alone but were not longer significant after adjusting for race and health behaviors. In summary, total cumulative stress, and its components of adverse life events and chronic stress were associated with decreased cardiac autonomic function as measured by HRV. Findings suggest one potential mechanism by which stress may exert adverse effects on mortality in healthy individuals. Primary preventive strategies including stress management may prove beneficial.
Energy Technology Data Exchange (ETDEWEB)
Smales, Ian; Muir, Stuart; Meredith, Charles; Baird, Robert
2011-07-01
Full text: Assessment of the effects on birds of wind turbine collisions has generally been focussed on the number of individuals that might be killed at a particular facility. However, this measure, of itself, may have little relevance to evaluating the potential or real effects on conservation status of threatened species. Determination of the overall effect any such mortality may have on the functioning of these populations will provide a better basis for decisions that have a strong foundation in ecology. For species with sufficient demographic information, we have developed and applied an approach combining collision risk modelling for all wind farms within the range of a threatened species with population modelling. This permits population-level evaluation of potential cumulative impacts of multiple wind farms. In Australia, regulatory authorities are increasingly interested in the cumulative risk to threatened species that may be posed by multiple wind energy facilities within a species. range. The approach outlined here has been applied in the pre-construction approval stage using collision risk modelling, and can be applied to operational facilities using data on actual mortalities. Cumulative modelling of risk posed by multiple wind farms requires different approaches for sedentary and migratory species. For sedentary species the cumulative effect will be the sum of the impact experienced by those parts of the population whose range intersects with wind farms. Cumulative impact is derived for migratory species by assessing the probability of birds surviving encounters with one wind farm after another on the migratory route and is thus the product of their survivorship rates for the relevant wind farms. The collision risk modelling used will be outlined along with the method in which it is integrated with a population model. Case studies for a crane (Brolga Grus rubicundus) and a parrot (orange- bellied parrot Neophema chrysogaster) species will be
Entanglement entropy and particle number cumulants of disordered fermions
Burmistrov, I. S.; Tikhonov, K. S.; Gornyi, I. V.; Mirlin, A. D.
2017-08-01
We study the entanglement entropy and particle number cumulants for a system of disordered noninteracting fermions in d dimensions. We show, both analytically and numerically, that for a weak disorder the entanglement entropy and the second cumulant (particle number variance) are proportional to each other with a universal coefficient. The corresponding expressions are analogous to those in the clean case but with a logarithmic factor regularized by the mean free path rather than by the system size. We also determine the scaling of higher cumulants by analytical (weak disorder) and numerical means. Finally, we predict that the particle number variance and the entanglement entropy are nonanalytic functions of disorder at the Anderson transition.
Broadening of dielectric response and sum rule conservation
Energy Technology Data Exchange (ETDEWEB)
Franta, Daniel, E-mail: franta@physics.muni.cz [Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlářká 2, 611 37 Brno (Czech Republic); CEITEC —Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno (Czech Republic); Nečas, David; Zajíčková, Lenka [Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlářká 2, 611 37 Brno (Czech Republic); CEITEC —Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno (Czech Republic); Ohlídal, Ivan [Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlářká 2, 611 37 Brno (Czech Republic)
2014-11-28
Different types of broadening of the dielectric response are studied with respect to the preservation of the Thomas–Reiche–Kuhn sum rule. It is found that only the broadening of the dielectric function and transition strength function conserve this sum rule, whereas the broadening of the transition probability function (joint density of states) increases or decreases the sum. The effect of different kinds of broadening is demonstrated for interband and intraband direct electronic transitions using simplified rectangular models. It is shown that the broadening of the dielectric function is more suitable for interband transitions while broadening of the transition strength function is more suitable for intraband transitions. - Highlights: • Preservation of the sum rule by different types of dielectric response broadening • Only broadening of dielectric function and transition strength function preserves it. • Broadening of joint density of states does not preserve the sum rule. • Broadening of dielectric function is better for direct interband transitions. • Broadening of transition strength is better for indirect interband transitions.
Transition Strength Sums and Quantum Chaos in Shell Model States
Kota, V K B; Kar, K; Gómez, J M G; Retamosa, J
2000-01-01
For the embedded Gaussian orthogonal ensemble (EGOE) of random matrices, the strength sums generated by a transition operator acting on an eigenstate vary with the excitation energy as the ratio of two Gaussians. This general result is compared to exact shell model calculations, with realistic interactions, of spherical orbit occupancies and Gamow-Teller strength sums in some $(ds)$ and $(fp)$ shell examples. In order to confirm that EGOE operates in the chaotic domain of the shell model spectrum, calculations are carried out using two different interpolating hamiltonians generating order-chaos transitions. Good agreement is obtained in the chaotic domain of the spectrum, and strong deviations are observed as nuclear motion approaches a regular regime (transition strength sums appear to follow the Dyson's $\\Delta_3$ statistic). More importantly, they shed new light on the newly emerging understanding that in the chaotic domain of isolated finite interacting many particle systems smoothed densities (they inclu...
Skew Schur Functions of Sums of Fat Staircases
Morin, Matthew
2010-01-01
We define a fat staircase to be a Ferrers diagram corresponding to a partition of the form $(n^{\\alpha_n}, {n-1}^{\\alpha_{n-1}},..., 1^{\\alpha_1})$, where $\\alpha = (\\alpha_1,...,\\alpha_n)$ is a composition, or the $180^\\circ$ rotation of such a diagram. If a diagram's skew Schur function is a linear combination of Schur functions of fat staircases, we call the diagram a sum of fat staircases. We prove a Schur-positivity result that is obtained each time we augment a sum of fat staircases with a skew diagram. We also determine conditions on which diagrams can be sums of fat staircases, including necessary and sufficient conditions in the special case when the diagram is a fat staircase skew a single row or column.
An efficient method for evaluating energy-dependent sum rules
Dinur, Nir Nevo; Bacca, Sonia; Barnea, Nir
2014-01-01
Energy-dependent sum rules are useful tools in many fields of physics. In nuclear physics, they typically involve an integration of the response function over the nuclear spectrum with a weight function composed of integer powers of the energy. More complicated weight functions are also encountered, e.g., in nuclear polarization corrections of atomic spectra. Using the Lorentz integral transform method and the Lanczos algorithm, we derive a computationally efficient technique for evaluating such sum rules that avoids the explicit calculation of both the continuum states and the response function itself. Our numerical results for electric dipole sum rules of the Helium-4 nucleus with various energy-dependent weights show rapid convergence with respect to the number of Lanczos steps. This demonstrates the usefulness of the method in a variety of electroweak reactions.
A supercharacter table decomposition via power-sum symmetric functions
Bergeron, Nantel
2011-01-01
We give an $AB$-factorization of the supercharacter table of the group of $n\\times n$ unipotent upper triangular matrices over $\\FF_q$, where $A$ is a lower-triangular matrix with entries in $\\ZZ[q]$ and $B$ is a unipotent upper-triangular matrix with entries in $\\ZZ[q^{-1}]$. To this end we introduce a $q$ deformation of a new power-sum basis of the Hopf algebra of symmetric functions in noncommutative variables. The factorization is obtain from the transition matrices between the supercharacter basis, the $q$-power-sum basis and the superclass basis. This is similar to the decomposition of the character table of the symmetric group $S_n$ given by the transition matrices between Schur functions, monomials and power-sums. We deduce some combinatorial results associated to this decomposition. In particular we compute the determinant of the supercharacter table.
Sums of hermitian squares and the BMV conjecture
Klep, Igor
2007-01-01
Recently Lieb and Seiringer showed that the Bessis-Moussa-Villani conjecture from quantum physics can be restated in the following purely algebraic way: The sum of all words in two positive semidefinite matrices where the number of each of the two letters is fixed is always a matrix with nonnegative trace. We show that this statement holds if the words are of length at most 13. This has previously been known only up to length 7. In our proof, we establish a connection to sums of hermitian squares of polynomials in noncommuting variables and to semidefinite programming. As a by-product we obtain an example of a real polynomial in two noncommuting variables having nonnegative trace on all symmetric matrices of the same size, yet not being a sum of hermitian squares and commutators.
Fermionic Sum Representations for Conformal Field Theory Characters
Kedem, R; McCoy, B M; Melzer, E
1993-01-01
We present sum representations for all characters of the unitary Virasoro minimal models. They can be viewed as fermionic companions of the Rocha-Caridi sum representations, the latter related to the (bosonic) Feigin-Fuchs-Felder construction. We also give fermionic representations for certain characters of the general $(G^{(1)})_k \\times (G^{(1)})_l \\over (G^{(1)})_{k+l}}$ coset conformal field theories, the non-unitary minimal models ${\\cal M}(p,p+2)$ and ${\\cal M}(p,kp+1)$, the $N$=2 superconformal series, and the $\\ZZ_N$-parafermion theories, and relate the $q\\to 1$ behaviour of all these fermionic sum representations to the thermodynamic Bethe Ansatz.
The lowest hidden charmed tetraquark state from QCD sum rules
Wang, Zhi-Gang
2015-01-01
In this article, we study the $S\\bar{S}$ type scalar tetraquark state $cq\\bar{c}\\bar{q}$ in details with the QCD sum rules by calculating the contributions of the vacuum condensates up to dimension-10 in the operator product expansion, and obtain the value $M_{Z_c}=\\left(3.82^{+0.08}_{-0.08}\\right)\\,\\rm{GeV}$, which is the lowest mass for the hidden charmed tetraquark states from the QCD sum rules. Furthermore, we calculate the hadronic coupling constants $G_{Z_c\\eta_c\\pi}$ and $G_{Z_cDD}$ with the three-point QCD sum rules, then study the strong decays $ Z_c\\to \\eta_c\\pi\\, ,\\, DD$, and observe that the total width $\\Gamma_{Z_c}\\approx 21\\,\\rm{MeV}$. The present predictions can be confronted with the experimental data in the futures at the BESIII, LHCb and Belle-II.
Limit theorems for multi-indexed sums of random variables
Klesov, Oleg
2014-01-01
Presenting the first unified treatment of limit theorems for multiple sums of independent random variables, this volume fills an important gap in the field. Several new results are introduced, even in the classical setting, as well as some new approaches that are simpler than those already established in the literature. In particular, new proofs of the strong law of large numbers and the Hajek-Renyi inequality are detailed. Applications of the described theory include Gibbs fields, spin glasses, polymer models, image analysis and random shapes. Limit theorems form the backbone of probability theory and statistical theory alike. The theory of multiple sums of random variables is a direct generalization of the classical study of limit theorems, whose importance and wide application in science is unquestionable. However, to date, the subject of multiple sums has only been treated in journals. The results described in this book will be of interest to advanced undergraduates, graduate students and researchers who ...
QCD Sum Rules at Finite Temperature: a Review
Ayala, Alejandro; Loewe, M
2016-01-01
The method of QCD sum rules at finite temperature is reviewed, with emphasis on recent results. These include predictions for the survival of charmonium and bottonium states, at and beyond the critical temperature for de-confinement, as later confirmed by lattice QCD simulations. Also included are determinations in the light-quark vector and axial-vector channels, allowing to analyse the Weinberg sum rules, and predict the dimuon spectrum in heavy ion collisions in the region of the rho-meson. Also in this sector, the determination of the temperature behaviour of the up-down quark mass, together with the pion decay constant, will be described. Finally, an extension of the QCD sum rule method to incorporate finite baryon chemical potential is reviewed.
Ramanujan sums via generalized Möbius functions and applications
Directory of Open Access Journals (Sweden)
Vichian Laohakosol
2006-01-01
Full Text Available A generalized Ramanujan sum (GRS is defined by replacing the usual Möbius function in the classical Ramanujan sum with the Souriau-Hsu-Möbius function. After collecting basic properties of a GRS, mostly containing existing ones, seven aspects of a GRS are studied. The first shows that the unique representation of even functions with respect to GRSs is possible. The second is a derivation of the mean value of a GRS. The third establishes analogues of the remarkable Ramanujan's formulae connecting divisor functions with Ramanujan sums. The fourth gives a formula for the inverse of a GRS. The fifth is an analysis showing when a reciprocity law exists. The sixth treats the problem of dependence. Finally, some characterizations of completely multiplicative function using GRSs are obtained and a connection of a GRS with the number of solutions of certain congruences is indicated.
Heavy hybrid mesons in the QCD sum rule
Huang, Peng-Zhi
2011-01-01
We study the spectra of the hybrid mesons containing one heavy quark ($q\\bar{Q}g$) within the framework of QCD sum rules in the heavy quark limit. The derived sum rules are stable with the variation of the Borel parameter within their corresponding working ranges. The extracted binding energy for the heavy hybrid doublets $H(S)$ and $M(T)$ is almost degenerate. We also calculate the pionic couplings between these heavy hybrid and the conventional heavy meson doublets using the light-cone QCD sum rule method. The extracted coupling constants are rather small as a whole. With these couplings we make a rough estimate of the partial widths of these pionic decay channels.
On the Predictivity of Neutrino Mass Sum Rules
Gehrlein, Julia; Spinrath, Martin
2016-01-01
Correlations between light neutrino observables are arguably the strongest predictions of lepton flavour models based on (discrete) symmetries, except for the very few cases which unambiguously predict the full set of leptonic mixing angles. A subclass of these correlations are neutrino mass sum rules, which connect the three (complex) light neutrino mass eigenvalues among each other. This connection constrains both the light neutrino mass scale and the Majorana phases, so that mass sum rules generically lead to a non-zero value of the lightest neutrino mass and to distinct predictions for the effective mass probed in neutrinoless double beta decay. However, in nearly all cases known, the neutrino mass sum rules are not exact and receive corrections from various sources. We introduce a formalism to handle these corrections perturbatively in a model-independent manner, which overcomes issues present in earlier approaches. Our ansatz allows us to quantify the modification of the predictions derived from neutrin...
Online Scheduling in Manufacturing A Cumulative Delay Approach
Suwa, Haruhiko
2013-01-01
Online scheduling is recognized as the crucial decision-making process of production control at a phase of “being in production" according to the released shop floor schedule. Online scheduling can be also considered as one of key enablers to realize prompt capable-to-promise as well as available-to-promise to customers along with reducing production lead times under recent globalized competitive markets. Online Scheduling in Manufacturing introduces new approaches to online scheduling based on a concept of cumulative delay. The cumulative delay is regarded as consolidated information of uncertainties under a dynamic environment in manufacturing and can be collected constantly without much effort at any points in time during a schedule execution. In this approach, the cumulative delay of the schedule has the important role of a criterion for making a decision whether or not a schedule revision is carried out. The cumulative delay approach to trigger schedule revisions has the following capabilities for the ...
Cumulative Risks of Foster Care Placement for Danish Children
DEFF Research Database (Denmark)
Fallesen, Peter; Emanuel, Natalia; Wildeman, Christopher
2014-01-01
Although recent research suggests that the cumulative risk of foster care placement is far higher for American children than originally suspected, little is known about the cumulative risk of foster care placement in other countries, which makes it difficult to gauge the degree to which factor...... is for Danish children. Results suggest that at the beginning of the study period (in 1998) the cumulative risk of foster care placement for Danish children was roughly in line with the risk for American children. Yet, by the end of the study period (2010), the risk had declined to half the risk for American...... foster care placement is salient in other contexts. In this article, we provide companion estimates to those provided in recent work on the US by using Danish registry data and synthetic cohort life tables to show how high and unequally distributed the cumulative risk of foster care placement...
Mapping cumulative human impacts in the eastern North Sea
DEFF Research Database (Denmark)
Stock, A.; Andersen, Jesper; Heinänen, S.
of the MSFD; and 3) to deepen the understanding of how errors in expert judgment affect the resulting cumulative human impact maps by means of Monte Carlo simulations. We combined existing data sets on the spatial distribution of 33 anthropogenic stressors (linked to the MSFD pressures) and 28 key habitats....... In contrast, the predicted impacts for much of the Norwegian EEZ and areas far offshore were lower. The Monte Carlo simulations confirmed earlier findings that mapping cumulative impacts is generally "robust", but also showed that specific combinations of errors can seriously change local and regional...... on marine ecosystems have only recently been developed. The aims of our study were: 1) to develop a map of cumulative human impacts for the Danish, Swedish, Norwegian and German parts of the Greater North Sea; 2) to adjust the existing methods for mapping cumulative human impacts to fit the requirements...
Cumulative Production Per Township - SaMiRa
U.S. Geological Survey, Department of the Interior — This dataset contains a selected township grid within the Sagebrush Mineral Resource Assessment project (SaMiRa) study area attributed with cumulative oil and gas...
Cumulative radiation exposure in children with cystic fibrosis.
LENUS (Irish Health Repository)
O'Reilly, R
2010-02-01
This retrospective study calculated the cumulative radiation dose for children with cystic fibrosis (CF) attending a tertiary CF centre. Information on 77 children with a mean age of 9.5 years, a follow up time of 658 person years and 1757 studies including 1485 chest radiographs, 215 abdominal radiographs and 57 computed tomography (CT) scans, of which 51 were thoracic CT scans, were analysed. The average cumulative radiation dose was 6.2 (0.04-25) mSv per CF patient. Cumulative radiation dose increased with increasing age and number of CT scans and was greater in children who presented with meconium ileus. No correlation was identified between cumulative radiation dose and either lung function or patient microbiology cultures. Radiation carries a risk of malignancy and children are particularly susceptible. Every effort must be made to avoid unnecessary radiation exposure in these patients whose life expectancy is increasing.
Macroscopic cumulative fatigue damage of material under nonsymmetrical cycle
Institute of Scientific and Technical Information of China (English)
盖秉政
2002-01-01
Hashin's macroscopic theory of fatigue damage is further discussed and a new method has been proposed for prediction of cumulative fatigue damage of material and its lifetime under nonsymmetrical cyclic loading.
Translation-Invariant Representation for Cumulative Foot Pressure Images
Zheng, Shuai; Tan, Tieniu
2010-01-01
Human can be distinguished by different limb movements and unique ground reaction force. Cumulative foot pressure image is a 2-D cumulative ground reaction force during one gait cycle. Although it contains pressure spatial distribution information and pressure temporal distribution information, it suffers from several problems including different shoes and noise, when putting it into practice as a new biometric for pedestrian identification. In this paper, we propose a hierarchical translation-invariant representation for cumulative foot pressure images, inspired by the success of Convolutional deep belief network for digital classification. Key contribution in our approach is discriminative hierarchical sparse coding scheme which helps to learn useful discriminative high-level visual features. Based on the feature representation of cumulative foot pressure images, we develop a pedestrian recognition system which is invariant to three different shoes and slight local shape change. Experiments are conducted on...
Some Characterization Results on Dynamic Cumulative Residual Tsallis Entropy
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Madan Mohan Sati
2015-01-01
Full Text Available We propose a generalized cumulative residual information measure based on Tsallis entropy and its dynamic version. We study the characterizations of the proposed information measure and define new classes of life distributions based on this measure. Some applications are provided in relation to weighted and equilibrium probability models. Finally the empirical cumulative Tsallis entropy is proposed to estimate the new information measure.
Steps and pips in the history of the cumulative recorder.
Lattal, Kennon A.
2004-01-01
From its inception in the 1930s until very recent times, the cumulative recorder was the most widely used measurement instrument in the experimental analysis of behavior. It was an essential instrument in the discovery and analysis of schedules of reinforcement, providing the first real-time analysis of operant response rates and patterns. This review traces the evolution of the cumulative recorder from Skinner's early modified kymographs through various models developed by Skinner and his co...
Sum of Roots Characterization for H2 Control Performance Limitations
Hara, Shinji; Kanno, Masaaki
This paper provides new expressions of H2 control performance limits achievable by feedback for SISO continuous-time systems. The result for the regulation problem is expressed in a simple manner in terms of two sums of roots obtained from the plant and the associated polynomial spectral factorization. We show that it can connect the two existing solutions, namely the Riccati solution and the analytical expression with an integral form. The similar result for the tracking problem is also derived using the reciprocal transform. Finally parametric optimization making use of the derived expression by means of symbolic computation is demonstrated to confirm the validity of the sum of roots characterization.
Charm quark mass determined from a pair of sum rules
Erler, Jens; Spiesberger, Hubert
2016-01-01
In this paper, we present preliminary results of the determination of the charm quark mass $\\hat{m}_c$ from QCD sum rules of moments of the vector current correlator calculated in perturbative QCD at ${\\cal O} (\\hat \\alpha_s^3)$. Self-consistency between two different sum rules allow to determine the continuum contribution to the moments without requiring experimental input, except for the charm resonances below the continuum threshold. The existing experimental data from the continuum region is used, then, to confront the theoretical determination and reassess the theoretic uncertainty.
A Global Optimization Algorithm for Sum of Linear Ratios Problem
Directory of Open Access Journals (Sweden)
Yuelin Gao
2013-01-01
Full Text Available We equivalently transform the sum of linear ratios programming problem into bilinear programming problem, then by using the linear characteristics of convex envelope and concave envelope of double variables product function, linear relaxation programming of the bilinear programming problem is given, which can determine the lower bound of the optimal value of original problem. Therefore, a branch and bound algorithm for solving sum of linear ratios programming problem is put forward, and the convergence of the algorithm is proved. Numerical experiments are reported to show the effectiveness of the proposed algorithm.
A new neutrino mass sum rule from inverse seesaw
Dorame, L; Peinado, E; Rojas, Alma D; Valle, J W F
2012-01-01
A class of discrete flavor-symmetry-based models predicts constrained neutrino mass matrix schemes that lead to specific neutrino mass sum-rules (MSR). One of these implies in a lower bound on the effective neutrinoless double beta mass parameter, even for normal hierarchy neutrinos. Here we propose a new model based on the S4 flavor symmetry that leads to the new neutrino mass sum-rule and discuss how to generate a nonzero value for the reactor mixing angle indicated by recent experiments, and the resulting correlation with the solar mixing angle.
Testing solar lepton mixing sum rules in neutrino oscillation experiments
Ballett, Peter; Luhn, Christoph; Pascoli, Silvia; Schmidt, Michael A
2014-01-01
Small discrete family symmetries such as S4, A4 or A5 may lead to simple leading-order predictions for the neutrino mixing matrix such as the bimaximal, tribimaximal or golden ratio mixing patterns, which may be brought into agreement with experimental data with the help of corrections from the charged-lepton sector. Such scenarios generally lead to relations among the parameters of the physical leptonic mixing matrix known as solar lepton mixing sum rules. In this article, we present a simple derivation of such solar sum rules, valid for arbitrary neutrino and charged lepton mixing angles and phases, assuming only {\\theta}13^{\
IDENTITIES INVOLVING RATIONAL SUMS BY INVERSION AND PARTIAL FRACTION DECOMPOSITION
Directory of Open Access Journals (Sweden)
Helmut Prodinger
2008-03-01
Full Text Available Identities appearing recentlyin: {sc J. L. D'{i}az-Barrero, J. Gibergans-B'agu-ena, P. G. Popescu:}{it Some identities involving rational sums}. Appl. Anal. Discrete Math., {f 1} (2007, 397--402, aretreated by inverting them; the resulting sums areevaluated using partial fraction decomposition, following{sc Wenchang Chu:} {it A binomial coefficient identity associated with {B}eukers' conjectureon {A}p'ery numbers.} Electron. J. Combin., {f 11} (1: Note 15, 3 pp. (electronic, 2004.This approach produces a general formula, not only special cases.
Sums of Laplace eigenvalues - rotationally symmetric maximizers in the plane
Laugesen, R S
2010-01-01
The sum of the first $n \\geq 1$ eigenvalues of the Laplacian is shown to be maximal among triangles for the equilateral triangle, maximal among parallelograms for the square, and maximal among ellipses for the disk, provided the ratio $\\text{(area)}^3/\\text{(moment of inertia)}$ for the domain is fixed. This result holds for both Dirichlet and Neumann eigenvalues, and similar conclusions are derived for Robin boundary conditions and Schr\\"odinger eigenvalues of potentials that grow at infinity. A key ingredient in the method is the tight frame property of the roots of unity. For general convex plane domains, the disk is conjectured to maximize sums of Neumann eigenvalues.
A Derivative of the Gerasimov-Drell-Hearn Sum Rule
Energy Technology Data Exchange (ETDEWEB)
Vladimir Pascalutsa; Barry Holstein; Marc Vanderhaeghen
2004-08-01
We derive a sum rule which establishes a linear relation between a particle's anomalous magnetic moment and a quantity connected to the photoabsorption cross-section. This quantity cannot be measured directly. However, it can be computed within a given theory. As an example, we demonstrate validity of the sum rule in QED at tree level---the renowned Schwinger's correction to the anomalous magnetic moment is readily reproduced. In the case of the strong interactions, we also consider the calculation of the nucleon magnetic moment within chiral theories.
A derivative of the Gerasimov Drell Hearn sum rule
Pascalutsa, Vladimir; Holstein, Barry R.; Vanderhaeghen, Marc
2004-10-01
We derive a sum rule which establishes a linear relation between a particle's anomalous magnetic moment and a quantity connected to the photoabsorption cross section. This quantity cannot be measured directly. However, it can be computed within a given theory. As an example, we demonstrate validity of the sum rule in QED at tree level-the renowned Schwinger's correction to the anomalous magnetic moment is readily reproduced. In the case of the strong interactions, we also consider the calculation of the nucleon magnetic moment within chiral theories.
A derivative of the Gerasimov-Drell-Hearn sum rule
Energy Technology Data Exchange (ETDEWEB)
Pascalutsa, Vladimir [Theory Group, JLab, 12000 Jefferson Ave, Newport News, VA 23606 (United States) and Department of Physics, College of William and Mary, Williamsburg, VA 23188 (United States)]. E-mail: vlad@jlab.org; Holstein, Barry R. [Theory Group, JLab, 12000 Jefferson Ave, Newport News, VA 23606 (United States) and Department of Physics-LGRT, University of Massachusetts, Amherst, MA 01003 (United States)]. E-mail: holstein@physics.umas.edu; Vanderhaeghen, Marc [Theory Group, JLab, 12000 Jefferson Ave, Newport News, VA 23606 (United States) and Department of Physics, College of William and Mary, Williamsburg, VA 23188 (United States)]. E-mail: marcvdh@jlab.org
2004-10-28
We derive a sum rule which establishes a linear relation between a particle's anomalous magnetic moment and a quantity connected to the photoabsorption cross section. This quantity cannot be measured directly. However, it can be computed within a given theory. As an example, we demonstrate validity of the sum rule in QED at tree level-the renowned Schwinger's correction to the anomalous magnetic moment is readily reproduced. In the case of the strong interactions, we also consider the calculation of the nucleon magnetic moment within chiral theories.
A zero-sum monetary system, interest rates, and implications
Hanley, Brian P
2015-01-01
To the knowledge of the author, this is the first time it has been shown that interest rates that are extremely high by modern standards are necessary within a zero-sum monetary system. Extreme interest rates persisted for long periods of time in many places. Prior to the invention of banking, most money was hard-money in the form of some type of coin. Here a model is presented that examines the interest rate required to succeed as an investor in a zero-sum hard-money system. Even when the pl...
Impact of Duality Violations on Spectral Sum Rule Analyses
Cata, O
2007-01-01
Recent sum rule analyses on the two-point correlator have led to significant discrepancies in the values found for the OPE condensates, most dramatically in the dimension eight condensate and to a lesser extent in the dimension six one. Precise knowledge of these condensates is of relevance in kaon decays and therefore it seems mandatory to assess the actual impact of what is commonly neglected in spectral sum rules, most prominently the issue of duality violations. We will explicitly compute them in a toy model and show that they are a priori non-negligible.
Childhood Cumulative Risk Exposure and Adult Amygdala Volume and Function.
Evans, Gary W; Swain, James E; King, Anthony P; Wang, Xin; Javanbakht, Arash; Ho, S Shaun; Angstadt, Michael; Phan, K Luan; Xie, Hong; Liberzon, Israel
2016-06-01
Considerable work indicates that early cumulative risk exposure is aversive to human development, but very little research has examined the neurological underpinnings of these robust findings. This study investigates amygdala volume and reactivity to facial stimuli among adults (mean 23.7 years of age, n = 54) as a function of cumulative risk exposure during childhood (9 and 13 years of age). In addition, we test to determine whether expected cumulative risk elevations in amygdala volume would mediate functional reactivity of the amygdala during socioemotional processing. Risks included substandard housing quality, noise, crowding, family turmoil, child separation from family, and violence. Total and left hemisphere adult amygdala volumes were positively related to cumulative risk exposure during childhood. The links between childhood cumulative risk exposure and elevated amygdala responses to emotionally neutral facial stimuli in adulthood were mediated by the corresponding amygdala volumes. Cumulative risk exposure in later adolescence (17 years of age), however, was unrelated to subsequent adult amygdala volume or function. Physical and socioemotional risk exposures early in life appear to alter amygdala development, rendering adults more reactive to ambiguous stimuli such as neutral faces. These stress-related differences in childhood amygdala development might contribute to the well-documented psychological distress as a function of early risk exposure.
Oldfield, Jeremy; Humphrey, Neil; Hebron, Judith
2015-01-01
Research has identified multiple risk factors for the development of behaviour difficulties. What have been less explored are the cumulative effects of exposure to multiple risks on behavioural outcomes, with no study specifically investigating these effects within a population of young people with special educational needs and disabilities (SEND). Furthermore, it is unclear whether a threshold or linear risk model better fits the data for this population. The sample included 2660 children and 1628 adolescents with SEND. Risk factors associated with increases in behaviour difficulties over an 18-month period were summed to create a cumulative risk score, with this explanatory variable being added into a multi-level model. A quadratic term was then added to test the threshold model. There was evidence of a cumulative risk effect, suggesting that exposure to higher numbers of risk factors, regardless of their exact nature, resulted in increased behaviour difficulties. The relationship between risk and behaviour difficulties was non-linear, with exposure to increasing risk having a disproportionate and detrimental impact on behaviour difficulties in child and adolescent models. Interventions aimed at reducing behaviour difficulties need to consider the impact of multiple risk variables. Tailoring interventions towards those exposed to large numbers of risks would be advantageous.
Directory of Open Access Journals (Sweden)
Abolmaali Nasreddin
2008-07-01
Full Text Available Abstract Objectives To examine the dose-response relationship between cumulative exposure to kneeling and squatting as well as to lifting and carrying of loads and symptomatic knee osteoarthritis (OA in a population-based case-control study. Methods In five orthopedic clinics and five practices we recruited 295 male patients aged 25 to 70 with radiographically confirmed knee osteoarthritis associated with chronic complaints. A total of 327 male control subjects were recruited. Data were gathered in a structured personal interview. To calculate cumulative exposure, the self-reported duration of kneeling and squatting as well as the duration of lifting and carrying of loads were summed up over the entire working life. Results The results of our study support a dose-response relationship between kneeling/squatting and symptomatic knee osteoarthritis. For a cumulative exposure to kneeling and squatting > 10.800 hours, the risk of having radiographically confirmed knee osteoarthritis as measured by the odds ratio (adjusted for age, region, weight, jogging/athletics, and lifting or carrying of loads is 2.4 (95% CI 1.1–5.0 compared to unexposed subjects. Lifting and carrying of loads is significantly associated with knee osteoarthritis independent of kneeling or similar activities. Conclusion As the knee osteoarthritis risk is strongly elevated in occupations that involve both kneeling/squatting and heavy lifting/carrying, preventive efforts should particularly focus on these "high-risk occupations".
Directory of Open Access Journals (Sweden)
Giżyńska Marta
2016-03-01
Full Text Available Nowadays in radiotherapy, much effort is taken to minimize the irradiated volume and consequently minimize doses to healthy tissues. In our work, we tested the hypothesis that the mean dose distribution calculated from a few first fractions can serve as prediction of the cumulated dose distribution, representing the whole treatment. We made our tests for 25 prostate cancer patients treated with three orthogonal fields technique. We did a comparison of dose distribution calculated as a sum of dose distribution from each fraction with a dose distribution calculated with isocenter shifted for a mean setup error from a few first fractions. The cumulative dose distribution and predicted dose distributions are similar in terms of gamma (3 mm 3% analysis, under condition that we know setup error from seven first fractions. We showed that the dose distribution calculated for the original plan with the isocenter shifted to the point, defined as the original isocenter corrected of the mean setup error estimated from the first seven fractions supports our hypothesis, i.e. can serve as a prediction for cumulative dose distribution.
Determination of rotational temperature of AlO from the $B^{2}\\sum^{+} -X^{2}\\sum^{+}$ system
Indian Academy of Sciences (India)
M M Chaudhari; C T Londhe; S H Behere
2006-03-01
AlO molecule was excited in a DC arc in air running between two aluminium electrodes. Rotational structure of the (0,0) band of the $B^{2}\\sum^{+} -x^{2}\\sum^{+}$ system of AlO molecule was photographed in the first order of a 10.6 m concave grating spectrograph. Intensity distribution amongst the well-resolved rotational lines of R1 and R2 branches was recorded and the average rotational temperature calculated from these has been determined as 2880 ± 100 K.
Pointwise Approximation for the Iterated Boolean Sums of Bernstein Operators
Institute of Scientific and Technical Information of China (English)
HUO Xiao-yan; LI Cui-xiang; YAO Qiu-mei
2013-01-01
In this paper,with the help of modulus of smoothness ω2r(4)(f,t),we discuss the pointwise approximation properties for the iterated Boolean sums of Bernstein operator Bnn and obtain direct and inverse theorems when 1-1/r ≤ λ ≤ 1,r ∈ N.
Decay Constants of Beauty Mesons from QCD Sum Rules
Lucha, Wolfgang; Simula, Silvano
2014-01-01
Our recently completed analysis of the decay constants of both pseudoscalar and vector beauty mesons reveals that in the bottom-quark sector two specific features of the sum-rule predictions show up: (i) For the input value of the bottom-quark mass in the $\\overline{\\rm MS}$ scheme $\\overline{m}_b(\\overline{m}_b)\\approx4.18\\;\\mbox{GeV},$ the sum-rule result $f_B\\approx210$-$220\\;\\mbox{MeV}$ for the $B$ meson decay constant is substantially larger than the recent lattice-QCD finding $f_B\\approx190\\;\\mbox{MeV}.$ Requiring QCD sum rules to reproduce the lattice-QCD value of $f_B$ yields a significantly larger $b$-quark mass: $\\overline{m}_b(\\overline{m}_b)=4.247\\;\\mbox{GeV}.$ (ii) Whereas QCD sum-rule predictions for the charmed-meson decay constants $f_D,$ $f_{D_s},$ $f_{D^*}$ and $f_{D_s^*}$ are practically independent of the choice of renormalization scale, in the beauty sector the results for the decay constants - and especially for the ratio $f_{B^*}/f_B$ - prove to be very sensitive to the specific scale s...
Decay Constants of Beauty Mesons from QCD Sum Rules
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Lucha Wolfgang
2014-01-01
Full Text Available Our recently completed analysis of the decay constants of both pseudoscalar and vector beauty mesons reveals that in the bottom-quark sector two specific features of the sum-rule predictions show up: (i For the input value of the bottom-quark mass in the M̅S̅ scheme m̅b(m̅b ≈ 4:18 GeV; the sum-rule result fB ≈ 210–220 MeV for the B meson decay constant is substantially larger than the recent lattice-QCD finding fB ≈ 190 MeV: Requiring QCD sum rules to reproduce the lattice-QCD value of fB yields a significantly larger b-quark mass: m̅b(m̅b = 4:247 GeV: (ii Whereas QCD sum-rule predictions for the charmed-meson decay constants fD; fDs, fD* and fDs* are practically independent of the choice of renormalization scale, in the beauty sector the results for the decay constants—and especially for the ratio fB* / fB—prove to be very sensitive to the specific scale setting.
Beauty Vector Meson Decay Constants from QCD Sum Rules
Lucha, Wolfgang; Simula, Silvano
2016-01-01
We present the outcomes of a very recent investigation of the decay constants of nonstrange and strange heavy-light beauty vector mesons, with special emphasis on the ratio of any such decay constant to the decay constant of the corresponding pseudoscalar meson, by means of Borel-transformed QCD sum rules. Our results suggest that both these ratios are below unity.
Standardization of I-125. Sum-Peak Coincidence Counting
Energy Technology Data Exchange (ETDEWEB)
Grau Carles, A.; Grau Malonda, A.
2011-07-01
I-125 is a nuclide which presents difficulties for standardization. The sum-peak method is one of the procedures used to standardize this radionuclide. Initially NaI (Tl)detectors and then the semiconductor detectors with higher resolution have been used.This paper describes the different methods based on the sum-peak procedure and the different expressions used to calculate the activity are deduced. We describe a general procedure for obtaining all of the above equations and many more. We analyze the influence of uncertainties in the used parameters in the uncertainty of the activity. We give a complete example of the transmission of uncertainty and the effects of correlations in the uncertainty of the activity of the sample. High-resolution spectra show an unresolved doublet of 62.0 keV and 62.8 keV. The paper presents two approaches to solve this problem. One is based on the calculation of area ratio and the sum of peak areas obtained from atomic and nuclear data, in the other we modify the equations so that the sum of the peak areas doublet, rather than its components, is present. (Author) 19 refs.
Efficient simulation of tail probabilities of sums of correlated lognormals
DEFF Research Database (Denmark)
Asmussen, Søren; Blanchet, José; Juneja, Sandeep;
We consider the problem of efficient estimation of tail probabilities of sums of correlated lognormals via simulation. This problem is motivated by the tail analysis of portfolios of assets driven by correlated Black-Scholes models. We propose two estimators that can be rigorously shown to be eff...
QCD sum rule studies at finite density and temperature
Energy Technology Data Exchange (ETDEWEB)
Kwon, Youngshin
2010-01-21
In-medium modifications of hadronic properties have a strong connection to the restoration of chiral symmetry in hot and/or dense medium. The in-medium spectral functions for vector and axial-vector mesons are of particular interest in this context, considering the experimental dilepton production data which signal the in-medium meson properties. In this thesis, finite energy sum rules are employed to set constraints for the in-medium spectral functions of vector and axial-vector mesons. Finite energy sum rules for the first two moments of the spectral functions are investigated with emphasis on the role of a scale parameter related to the spontaneous chiral symmetry breaking in QCD. It is demonstrated that these lowest moments of vector current spectral functions do permit an accurate sum rule analysis with controlled inputs, such as the QCD condensates of lowest dimensions. In contrast, the higher moments contain uncertainties from the higher dimensional condensates. It turns out that the factorization approximation for the four-quark condensate is not applicable in any of the cases studied in this work. The accurate sum rules for the lowest two moments of the spectral functions are used to clarify and classify the properties of vector meson spectral functions in a nuclear medium. Possible connections with the Brown-Rho scaling hypothesis are also discussed. (orig.)
Beauty vector meson decay constants from QCD sum rules
Energy Technology Data Exchange (ETDEWEB)
Lucha, Wolfgang [Institute for High Energy Physics, Austrian Academy of Sciences, Nikolsdorfergasse 18, A-1050 Vienna (Austria); Melikhov, Dmitri [Institute for High Energy Physics, Austrian Academy of Sciences, Nikolsdorfergasse 18, A-1050 Vienna (Austria); D. V. Skobeltsyn Institute of Nuclear Physics, M. V. Lomonosov Moscow State University, 119991, Moscow (Russian Federation); Simula, Silvano [Istituto Nazionale di Fisica Nucleare, Sezione di Roma Tre, Via della Vasca Navale 84, I-00146, Roma (Italy)
2016-01-22
We present the outcomes of a very recent investigation of the decay constants of nonstrange and strange heavy-light beauty vector mesons, with special emphasis on the ratio of any such decay constant to the decay constant of the corresponding pseudoscalar meson, by means of Borel-transformed QCD sum rules. Our results suggest that both these ratios are below unity.
Renormalisation Group Corrections to Neutrino Mixing Sum Rules
Gehrlein, J; Spinrath, M; Titov, A V
2016-01-01
Neutrino mixing sum rules are common to a large class of models based on the (discrete) symmetry approach to lepton flavour. In this approach the neutrino mixing matrix $U$ is assumed to have an underlying approximate symmetry form $\\tilde{U}_{\
Sums of variables at the onset of chaos, replenished
Diaz-Ruelas, Alvaro; Robledo, Alberto
2016-11-01
As a counterpart to our previous study of the stationary distribution formed by sums of positions at the Feigenbaum point via the period-doubling cascade in the logistic map (Eur. Phys. J. B 87, 32 (2014)), we determine the family of related distributions for the accompanying cascade of chaotic band-splitting points in the same system. By doing this we rationalize how the interplay of regular and chaotic dynamics gives rise to either multiscale or gaussian limit distributions. As demonstrated before (J. Stat. Mech. 2010, P01001 (2010)), sums of trajectory positions associated with the chaotic-band attractors of the logistic map lead only to a gaussian limit distribution, but, as we show here, the features of the stationary multiscale distribution at the Feigenbaum point can be observed in the distributions obtained from finite sums with sufficiently small number of terms. The multiscale features are acquired from the repellor preimage structure that dominates the dynamics toward the chaotic attractors. When the number of chaotic bands increases this hierarchical structure with multiscale and discrete scale-invariant properties develops. Also, we suggest that the occurrence of truncated q-gaussian-shaped distributions for specially prescribed sums are t-Student distributions premonitory of the gaussian limit distribution.
Perturbative corrections to zero recoil inclusive B decay sum rules
Kapustin, A A; Wise, M B; Grinstein, B; Kapustin, Anton; Ligeti, Zoltan; Wise, Mark B; Grinstein, Benjamin
1996-01-01
Comparing the result of inserting a complete set of physical states in a time ordered product of b decay currents with the operator product expansion gives a class of zero recoil sum rules. They sum over physical states with excitation energies less than \\Delta, where \\Delta is much greater than the QCD scale and much less than the heavy charm and bottom quark masses. These sum rules have been used to derive an upper bound on the zero recoil limit of the B\\to D^* form-factor, and on the matrix element of the kinetic energy operator between B meson states. Perturbative corrections to the sum rules of order \\alpha_s(\\Delta) \\Delta^2/m_{c,b}^2 have previously been computed. We calculate the corrections of order \\alpha_s(\\Delta) and \\alpha_s^2(\\Delta) \\beta_0 keeping all orders in \\Delta/m_{c,b}, and show that these perturbative QCD corrections suppressed by powers of \\Delta/m_{c,b} significantly weaken the upper bound on the zero recoil B\\to D^* form-factor, and also on the kinetic energy operator's matrix eleme...
Algorithms for multidimensional spectral factorization and sum of squares
Napp Avelli, D.; Trentelman, H.L.
2008-01-01
In this paper, algorithms are developed for the problems of spectral factorization and sum of squares of polynomial matrices with n indeterminates, and a natural interpretation of the tools employed in the algorithms is given using ideas from the theory of lossless and dissipative systems. These
Numerical Radius Inequalities for Finite Sums of Operators
Directory of Open Access Journals (Sweden)
Mirmostafaee Alireza Kamel
2014-12-01
Full Text Available In this paper, we obtain some sharp inequalities for numerical radius of finite sums of operators. Moreover, we give some applications of our result in estimation of spectral radius. We also compare our results with some known results.
Lump Sum Moving Cost and Aggregate Office Space Use
G. Romijn
1997-01-01
textabstractWhen firms decide to change office space use, in many instances this involves relocation. Relocation involves sizable costs to the firm that can to a large extent be characterized as lump sum, i.e. independent of the change in demand. In this paper we propose and solve a model of the
Dibaryon decay sum rules and other multiquark states
Polanco-Euán, E N; Sánchez-Colón, G; Bambah, B A
2015-01-01
The decays of the antisymmetric dibaryon octet $D(8_F)$ into two baryon octets are considered. Sum rules for these decays in first order broken SU(3) are given. An SU(4) extension of the analysis is commented upon. Possibilities for the experimental observation of multibaryon and anti-multibaryon states is pointed out.
Sums over Graphs and Integration over Discrete Groupoids
Fiorenza, Domenico
2002-01-01
We show that sums over graphs such as appear in the theory of Feynman diagrams can be seen as integrals over discrete groupoids. From this point of view, basic combinatorial formulas of the theory of Feynman diagrams can be interpreted as pull-back or push-forward formulas for integrals over suitable groupoids.
On some Vongruence with Application to Exponential Sums
Indian Academy of Sciences (India)
Soon-Mo Jung
2004-02-01
We will study the solution of a congruence, $x≡ g^{(1/2)_g(2^n)}\\mathrm{mod} 2^n$, depending on the integers and , where $_g(2^n)$ denotes the order of modulo $2^n$. Moreover, we introduce an application of the above result to the study of an estimation of exponential sums.
Communicating the sum of sources over a network
Ramamoorthy, Aditya
2010-01-01
We consider the network communication scenario, over directed acyclic networks with unit capacity edges in which a number of sources $s_i$ each holding independent unit-entropy information $X_i$ wish to communicate the sum $\\sum{X_i}$ to a set of terminals $t_j$. We show that in the case in which there are only two sources or only two terminals, communication is possible if and only if each source terminal pair $s_i/t_j$ is connected by at least a single path. For the more general communication problem in which there are three sources and three terminals, we prove that a single path connecting the source terminal pairs does not suffice to communicate $\\sum{X_i}$. We then present an efficient encoding scheme which enables the communication of $\\sum{X_i}$ for the three sources, three terminals case, given that each source terminal pair is connected by two edge disjoint paths. Our encoding scheme includes a structural decomposition of the network at hand which may be found useful for other network coding problem...
Lump Sum Moving Cost and Aggregate Office Space Use
G. Romijn
1997-01-01
textabstractWhen firms decide to change office space use, in many instances this involves relocation. Relocation involves sizable costs to the firm that can to a large extent be characterized as lump sum, i.e. independent of the change in demand. In this paper we propose and solve a model of the dem
The Sensitive Infrared Signal Detection by Sum Frequency Generation
Wong, Teh-Hwa; Yu, Jirong; Bai, Yingxin
2013-01-01
An up-conversion device that converts 2.05-micron light to 700 nm signal by sum frequency generation using a periodically poled lithium niobate crystal is demonstrated. The achieved 92% up-conversion efficiency paves the path to detect extremely weak 2.05-micron signal with well established silicon avalanche photodiode detector for sensitive lidar applications.
Beauty vector meson decay constants from QCD sum rules
Lucha, Wolfgang; Melikhov, Dmitri; Simula, Silvano
2016-01-01
We present the outcomes of a very recent investigation of the decay constants of nonstrange and strange heavy-light beauty vector mesons, with special emphasis on the ratio of any such decay constant to the decay constant of the corresponding pseudoscalar meson, by means of Borel-transformed QCD sum rules. Our results suggest that both these ratios are below unity.
The Distribution of the Sum of Signed Ranks
Albright, Brian
2012-01-01
We describe the calculation of the distribution of the sum of signed ranks and develop an exact recursive algorithm for the distribution as well as an approximation of the distribution using the normal. The results have applications to the non-parametric Wilcoxon signed-rank test.
Improved light quark masses from pseudoscalar sum rules
Directory of Open Access Journals (Sweden)
Stephan Narison
2014-11-01
Full Text Available Using ratios of the inverse Laplace transform sum rules within stability criteria for the subtraction point μ in addition to the ones of the usual τ spectral sum rule variable and continuum threshold tc, we extract the π(1300 and K(1460 decay constants to order αs4 of perturbative QCD by including power corrections up to dimension-six condensates, tachyonic gluon mass for an estimate of large order PT terms, instanton and finite width corrections. Using these inputs with enlarged generous errors, we extract, in a model-independent and conservative ways, the sum of the scale-independent renormalization group invariant (RGI quark masses (mˆu+mˆq:q≡d,s and the corresponding running masses (m¯u+m¯q evaluated at 2 GeV. By giving the value of the ratio mu/md, we deduce the running quark masses m¯u,d,s and condensate 〈u¯u¯〉 and the scale-independent mass ratios: 2ms/(mu+md and ms/md. Using the positivity of the QCD continuum contribution to the spectral function, we also deduce, from the inverse Laplace transform sum rules, for the first time to order αs4, new lower bounds on the RGI masses which are translated into the running masses at 2 GeV and into upper bounds on the running quark condensate 〈u¯u¯〉. Our results summarized in Table 3 and compared with our previous results and with recent lattice averages suggest that precise phenomenological determinations of the sum of light quark masses require improved experimental measurements of the π(1.3 and K(1.46 hadronic widths and/or decay constants which are the dominant sources of errors in the analysis.
Cumulative risks of foster care placement for Danish children.
Fallesen, Peter; Emanuel, Natalia; Wildeman, Christopher
2014-01-01
Although recent research suggests that the cumulative risk of foster care placement is far higher for American children than originally suspected, little is known about the cumulative risk of foster care placement in other countries, which makes it difficult to gauge the degree to which factor foster care placement is salient in other contexts. In this article, we provide companion estimates to those provided in recent work on the US by using Danish registry data and synthetic cohort life tables to show how high and unequally distributed the cumulative risk of foster care placement is for Danish children. Results suggest that at the beginning of the study period (in 1998) the cumulative risk of foster care placement for Danish children was roughly in line with the risk for American children. Yet, by the end of the study period (2010), the risk had declined to half the risk for American children. Our results also show some variations by parental ethnicity and sex, but these differences are small. Indeed, they appear quite muted relative to racial/ethnic differences in these risks in the United States. Last, though cumulative risks are similar between Danish and American children (especially at the beginning of the study period), the age-specific risk profiles are markedly different, with higher risks for older Danish children than for older American children.
Latino Mothers' Cumulative Food Insecurity Exposure and Child Body Composition.
Hernandez, Daphne C
2016-01-01
To document whether an intergenerational transmission of food insecurity is occurring by assessing low-income foreign-born Latino mothers' experiences with food insecurity as none, once (either childhood or adulthood) or twice (during both childhood and adulthood). Also the association between maternal cumulative food insecurity and children's body composition was examined. Maternal self-reported surveys on retrospective measures of food insecurity during childhood, current measures of food insecurity, and demographics were collected from Houston-area community centers (N = 96). Children's body mass index (BMI) and waist circumference (WC) were directly assessed. Covariate-adjusted logistic regression models analyzed the association between cumulative food insecurity experiences and children's body composition. Fifty-eight percent of mothers experienced food insecurity both as a child and as an adult and 31% of the mothers experienced food insecurity either as a child or adult. Maternal cumulative exposure to food insecurity was unrelated to BMI but was negatively related to elevated WC. Although an intergenerational transmission of food insecurity does exist, maternal cumulative exposure to food insecurity does not impact children's body composition negatively in the short term. Studying the long-term effects of cumulative food insecurity exposure can provide information for the development and timing of obesity interventions.
USING CUMULATIVE NUMBER DENSITIES TO COMPARE GALAXIES ACROSS COSMIC TIME
Energy Technology Data Exchange (ETDEWEB)
Behroozi, Peter S.; Wechsler, Risa H. [Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Stanford, CA 94305 (United States); Marchesini, Danilo [Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States); Muzzin, Adam [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Papovich, Casey [Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Stefanon, Mauro [Physics and Astronomy Department, University of Missouri, Columbia, MO 65211 (United States)
2013-11-01
Comparing galaxies across redshifts at fixed cumulative number density is a popular way to estimate the evolution of specific galaxy populations. This method ignores scatter in mass accretion histories and galaxy-galaxy mergers, which can lead to errors when comparing galaxies over large redshift ranges (Δz > 1). We use abundance matching in the ΛCDM paradigm to estimate the median change in cumulative number density with redshift and provide a simple fit (+0.16 dex per unit Δz) for progenitors of z = 0 galaxies. We find that galaxy descendants do not evolve in the same way as galaxy progenitors, largely due to scatter in mass accretion histories. We also provide estimates for the 1σ range of cumulative number densities corresponding to galaxy progenitors and descendants. Finally, we discuss some limits on cumulative number density comparisons, which arise due to difficulties measuring physical quantities (e.g., stellar mass) consistently across redshifts. A public tool to calculate cumulative number density evolution for galaxies, as well as approximate halo masses, is available online.
Maintenance hemodialysis patients have high cumulative radiation exposure.
LENUS (Irish Health Repository)
Kinsella, Sinead M
2010-10-01
Hemodialysis is associated with an increased risk of neoplasms which may result, at least in part, from exposure to ionizing radiation associated with frequent radiographic procedures. In order to estimate the average radiation exposure of those on hemodialysis, we conducted a retrospective study of 100 patients in a university-based dialysis unit followed for a median of 3.4 years. The number and type of radiological procedures were obtained from a central radiology database, and the cumulative effective radiation dose was calculated using standardized, procedure-specific radiation levels. The median annual radiation dose was 6.9 millisieverts (mSv) per patient-year. However, 14 patients had an annual cumulative effective radiation dose over 20 mSv, the upper averaged annual limit for occupational exposure. The median total cumulative effective radiation dose per patient over the study period was 21.7 mSv, in which 13 patients had a total cumulative effective radiation dose over 75 mSv, a value reported to be associated with a 7% increased risk of cancer-related mortality. Two-thirds of the total cumulative effective radiation dose was due to CT scanning. The average radiation exposure was significantly associated with the cause of end-stage renal disease, history of ischemic heart disease, transplant waitlist status, number of in-patient hospital days over follow-up, and death during the study period. These results highlight the substantial exposure to ionizing radiation in hemodialysis patients.
Ansari, Imran Shafique
2013-06-01
The probability density function (PDF) and cumulative distribution function of the sum of L independent but not necessarily identically distributed squared η-μ variates, applicable to the output statistics of maximal ratio combining (MRC) receiver operating over η-μ fading channels that includes the Hoyt and the Nakagami-m models as special cases, is presented in closed-form in terms of the Fox\\'s H function. Further analysis, particularly on the bit error rate via PDF-based approach, is also represented in closed form in terms of the extended Fox\\'s H function (H). The proposed new analytical results complement previous results and are illustrated by extensive numerical and Monte Carlo simulation results. © 2013 IEEE.
27 CFR 19.245 - Bonds and penal sums of bonds.
2010-04-01
... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bonds and penal sums of... Bonds and penal sums of bonds. The bonds, and the penal sums thereof, required by this subpart, are as follows: Penal Sum Type of bond Basis Minimum Maximum (a) Operations bond: (1) One plant bond—...
Sums of Powers of Fibonacci and Lucas Polynomials in terms of Fibopolynomials
Velasco, Claudio de Jesus Pita Ruiz
2012-01-01
We study sums of powers of Fibonacci and Lucas polynomials of the form $% \\sum_{n=0}^{q}F_{tsn}^{k}(x) $ and $\\sum_{n=0}^{q}L_{tsn}^{k}% (x) $, where $s,t,k$ are given natural numbers, together with the corresponding alternating sums $\\sum_{n=0}^{q}(-1) ^{n}F_{tsn}^{k}(x) $ and $\\sum_{n=0}^{q}(-1) ^{n}L_{tsn}^{k}(x) $. We give sufficient conditions on the parameters $s,t,k$ for express these sums as linear combinations of certain $s$-Fibopolynomials.
Cumulative Trauma Among Mayas Living in Southeast Florida.
Millender, Eugenia I; Lowe, John
2016-01-04
Mayas, having experienced genocide, exile, and severe poverty, are at high risk for the consequences of cumulative trauma that continually resurfaces through current fear of an uncertain future. Little is known about the mental health and alcohol use status of this population. This correlational study explored t/he relationship of cumulative trauma as it relates to social determinants of health (years in the United States, education, health insurance status, marital status, and employment), psychological health (depression symptoms), and health behaviors (alcohol use) of 102 Guatemalan Mayas living in Southeast Florida. The results of this study indicated that, as specific social determinants of health and cumulative trauma increased, depression symptoms (particularly among women) and the risk for harmful alcohol use (particularly among men) increased. Identifying risk factors at an early stage before serious disease or problems are manifest provides room for early screening leading to early identification, early treatment, and better outcomes.
Analysis of sensory ratings data with cumulative link models
DEFF Research Database (Denmark)
Christensen, Rune Haubo Bojesen; Brockhoff, Per B.
2013-01-01
Examples of categorical rating scales include discrete preference, liking and hedonic rating scales. Data obtained on these scales are often analyzed with normal linear regression methods or with omnibus Pearson chi2 tests. In this paper we propose to use cumulative link models that allow...... for regression methods similar to linear models while respecting the categorical nature of the observations. We describe how cumulative link models are related to the omnibus chi2 tests and how they can lead to more powerful tests in the non-replicated setting. For replicated categorical ratings data we present...... a quasi-likelihood approach and a mixed effects approach both being extensions of cumulative link models. We contrast population-average and subject-specific interpretations based on these models and discuss how different approaches lead to different tests. In replicated settings, naive tests that ignore...
Cumulative pion production via successive collisions in nuclear medium
Motornenko, A
2016-01-01
Production of pions in proton-nucleus (p+A) reactions outside of a kinematical boundary of proton-nucleon collisions, the so-called cumulative effect, is studied. The kinematical restrictions on pions emitted in backward direction in the target rest frame are analyzed. It is shown that cumulative pion production requires a presence of massive baryonic resonances that are produced during successive collisions of projectile with nuclear nucleons. After each successive collision the mass of created resonance may increase and, simultaneously, its longitudinal velocity decreases. Simulations within Ultra relativistic Quantum Molecular Dynamics model reveals that successive collisions of baryonic resonances with nuclear nucleons plays the dominant role in cumulative pion production in p+A reactions.
Solid-state electro-cumulation effect numerical simulation
Grishin, V G
2001-01-01
It is an attempt to simulate as really as possible a crystal's interatomic interaction under conditions of "Solid-state electro-cumulation (super-polarization) effect". Some theoretical and experimental reasons to believe that within solid substances an interparticles interaction could concentrate from the surface to a centre were given formerly. Now, numerical results show the conditions that could make the cumulation more effective. Another keywords: ion, current, solid, symmetry, cumulation, polarization, depolarization, ionic conductor,superionic conductor, ice, crystal, strain, V-center, V-centre, doped crystal, interstitial impurity, intrinsic color center, high pressure technology, Bridgman, anvil, experiment, crowdion, dielectric, proton, layer, defect, lattice, dynamics, electromigration, mobility, muon catalysis, concentration, doping, dopant, conductivity, pycnonuclear reaction, permittivity, dielectric constant, point defects, interstitials, polarizability, imperfection, defect centers, glass, epi...
Association between diastolic blood pressure and cumulative work time
Directory of Open Access Journals (Sweden)
Ricardo Cordeiro
1999-01-01
Full Text Available Diastolic blood pressure was viewed as a generic indicator of aging, and its association with cumulative work time was studied after controlling for age as a potential confounding factor. The study was conducted among production line workers at a Brazilian tannery in July 1993. The association between diastolic blood pressure and cumulative work time was verified by fitting a second-order linear regression model, where diastolic blood pressure was a function of worker's age and cumulative work time. By fitting the model, one can predict that, in the beginning of working life at the tannery, on average each 1-year period is associated with an increase of about 1.5 mmHg in diastolic blood pressure. The fit obtained highlights one component directly associated with work as part of the rate of pressure increase in the study group. This component is twice as high as that directly associated with age.