scholarly journals Correlation between predictability index and the error performance of customer baseline load (CBL) calculation

Author(s):  
Saeed Mohajeryami ◽  
Valentina Cecchi

This paper attempts to explore the correlation between the content of high frequency component of customers' historical consumption data (measured by a proposed index called predictability index) and the accuracy of Customer Baseline Load (CBL) calculation methods. In this paper, the customer's consumption signal is transformed from time-domain to frequency domain to separate the high and low frequency components of the consumption signal. Then, after reconstructing the time-domain equivalent of both of these signals, the predictability index for all customers are calculated. The data employed by this study belong to Australian Energy Market Operation (AEMO), and is the hourly consumption of 189 customers for the time span of a year (2012). This index is proposed to be used for the purpose of clustering the customers into different bins by K-means clustering algorithm. Then the CBL for customers of each bin is calculated by two methods of CAISO and Randomized Controlled Trial (RCT), and then the average error in each bin is computed. Afterwards, the correlation between the average P_index of each bin, and its normalized average error is calculated. It is found that there is a strong correlation between the P_index and the error performance of the CBL calculation methods.

2016 ◽  
Author(s):  
Saeed Mohajeryami ◽  
Valentina Cecchi

This paper attempts to explore the correlation between the content of high frequency component of customers' historical consumption data (measured by a proposed index called predictability index) and the accuracy of Customer Baseline Load (CBL) calculation methods. In this paper, the customer's consumption signal is transformed from time-domain to frequency domain to separate the high and low frequency components of the consumption signal. Then, after reconstructing the time-domain equivalent of both of these signals, the predictability index for all customers are calculated. The data employed by this study belong to Australian Energy Market Operation (AEMO), and is the hourly consumption of 189 customers for the time span of a year (2012). This index is proposed to be used for the purpose of clustering the customers into different bins by K-means clustering algorithm. Then the CBL for customers of each bin is calculated by two methods of CAISO and Randomized Controlled Trial (RCT), and then the average error in each bin is computed. Afterwards, the correlation between the average P_index of each bin, and its normalized average error is calculated. It is found that there is a strong correlation between the P_index and the error performance of the CBL calculation methods.


2017 ◽  
Vol 46 (2) ◽  
pp. 792-801 ◽  
Author(s):  
W-J Guo ◽  
S-K Yao ◽  
Y-L Zhang ◽  
S-Y Du ◽  
H-F Wang ◽  
...  

Objective This study was performed to investigate impaired vagal activity to meal in patients with functional dyspepsia (FD) with delayed gastric emptying (GE). Methods Eighty-five patients were studied. GE parameters, including those in the overall and proximal stomach, were measured by GE functional tests at the Department of Nuclear Medicine. Autonomic nervous function was tested by spectral analysis of heart rate variability (HRV). The vagal activity and sympathetic activity were analyzed by recording the power in the high-frequency component (HF), low-frequency component (LF), and LF/HF ratio. Results Overall and proximal GE were delayed in 47.2% and 50.9% of the patients, respectively. Spectral analysis of HRV showed that the HF in patients with delayed proximal GE was significantly lower and that the LF/HF ratio was significantly higher than those in patients with normal proximal GE after a meal. Conclusion Delayed proximal GE might be caused by disrupted sympathovagal balance as a result of decreased vagal activity after a meal. Improvement in vagal activity may constitute an effective treatment method for patients with FD.


2014 ◽  
Vol 610 ◽  
pp. 789-796
Author(s):  
Jiang Bao Li ◽  
Zhen Hong Jia ◽  
Xi Zhong Qin ◽  
Lei Sheng ◽  
Li Chen

In order to improve the prediction accuracy of busy telephone traffic, this study proposes a busy telephone traffic prediction method that combines wavelet transformation and least square support vector machine (lssvm) model which is optimized by particle swarm optimization (pso) algorithm. Firstly, decompose the pretreatment of busy telephone traffic data with mallat algorithm and get low frequency component and high frequency component. Secondly, reconfigure each component and use pso_lssvm model predict each reconfigured one. Then the busy telephone traffic can be achieved. The experimental results show that the prediction model has higher prediction accuracy and stability.


1978 ◽  
Vol 1 (16) ◽  
pp. 105 ◽  
Author(s):  
Jay E. Leonard ◽  
Benno M. Brenninkmeyer

An array of electronic sensors was installed on Nauset Light Beach, Cape Cod, Massachusetts, U.S.A., in order to provide a description of the sediment movement during storm conditions. These sensors included two sediment concentration indicators (almometers) which monitor sediment movement as a function of elevation and time, one bidirectional electromagnetic current meter, and a resistive wave staff. Prior field studies performed during "normal" conditions have indicated that surf-zone suspended sediment movement is a low-frequency phenomenon, with the relatively high-frequency component (normal wave period) contributing little to the amount of total sediment transported. Development of a computational technique based upon discrete Fourier analysis and digital filtering called Spectrally Filtered Integration (SFI) provides the calculation and filtering of true units of sediment change in grams-per-liter. Moreover, the SFI technique eliminates the possibility spurious sediment information created by the presence of air bubbles in the water column. Generally, higher-frequency sediment movement is more common during storm conditions than during normal non-storm conditions. This movement is controlled not by the prevailing wave and swell periods, but by a longer period which may be due to water interactions below the surface.


2018 ◽  
Vol 10 (2) ◽  
pp. 62-65
Author(s):  
Teruhisa Komori

To clarify the physiological and psychological effects of deep breathing, the effects of extreme prolongation of expiration breathing (Okinaga) were investigated using electroencephalogram (EEG) and electrocardiogram (ECG). Participants were five male Okinaga practitioners in their 50s and 60s. Participants performed Okinaga for 31 minutes while continuous EEG and ECG measurements were taken. After 16 minutes of Okinaga, and until the end of the session, the percentages of theta and alpha 2 waves were significantly higher than at baseline. After 20 minutes, and until the end of the session, the percentage of beta waves was significantly lower than at baseline. The high frequency component of heart rate variability was significantly lower after 12 minutes of Okinaga and lasted until 23 minutes. The low frequency/high frequency ratio was significantly lower after 18 minutes of Okinaga and until the end of the session. Okinaga produced relaxation, suggesting that deep breathing may relieve anxiety. However, study limitations include potential ambiguity in the interpretation of the low frequency/high frequency ratio, the small sample, and the fact that EEG was measured only on the forehead.


2018 ◽  
Vol 10 (2) ◽  
Author(s):  
Teruhisa Komori

To clarify the physiological and psychological effects of deep breathing, the effects of extreme prolongation of expiration breathing (Okinaga) were investigated using electroencephalogram (EEG) and electrocardiogram (ECG). Participants were five male Okinaga practitioners in their 50s and 60s. Participants performed Okinaga for 31 minutes while continuous EEG and ECG measurements were taken. After 16 minutes of Okinaga, and until the end of the session, the percentages of theta and alpha 2 waves were significantly higher than at baseline. After 20 minutes, and until the end of the session, the percentage of beta waves was significantly lower than at baseline. The high frequency component of heart rate variability was significantly lower after 12 minutes of Okinaga and lasted until 23 minutes. The low frequency/high frequency ratio was significantly lower after 18 minutes of Okinaga and until the end of the session. Okinaga produced relaxation, suggesting that deep breathing may relieve anxiety. However, study limitations include potential ambiguity in the interpretation of the low frequency/high frequency ratio, the small sample, and the fact that EEG was measured only on the forehead.


1973 ◽  
Vol 51 (4) ◽  
pp. 628-635 ◽  
Author(s):  
Richard L. Reeves ◽  
Robert S. Kaiser ◽  
Mary S. Maggio ◽  
Edward A. Sylvestre ◽  
William H. Lawton

The absorption curves of methyl orange (MO) and analogous p-aminophenylazobenzenes in organic and aqueous organic solvents are shown to consist of two severely overlapping bands. The curves have been resolved into two skewed component bands using a regression method. The blue shift of the absorption maximum obtained when organic solvents are added to aqueous solutions of MO, or when MO is bound to bovine serum albumin or a surfactant micelle, is the result of a change in relative intensities of the component bands. The low-frequency component is assigned to a π1 → π1* transition of a solvate in which there is specific hydrogen-bonding interaction between solvent and the azo nitrogens, and the high-frequency component to a π1 → π1* transition of a solvate in which the interaction is absent. The low-frequency component is favored by aqueous solvent compositions and by low temperatures. The free energies of interconversion of the species in various hydrogen-bonding solvents are correlated by the solvent surface tension but not by the dielectric constant. The results show that the shift in absorption maximum accompanying binding to a protein or micelle should be interpreted as a shift in an equilibrium rather than as a shift in transition energy.


1970 ◽  
Vol 48 (19) ◽  
pp. 3019-3025 ◽  
Author(s):  
George Brink ◽  
Michael Falk

The OH and OD stretching bands of HDO in aqueous solutions containing the ions ClO4− and BF4− are split into two components. The high-frequency component, A, does not shift with temperature. It is interpreted as due to OH groups involved in weak [Formula: see text] or [Formula: see text] hydrogen bonds. This interpretation is in line with the corresponding OH frequencies of other systems containing ClO4− ions, such as methanolic solutions and crystalline hydrates. Solvent-separated ion pairs may account for the observed cation effect on band A. The low-frequency component, B, varies with temperature almost exactly like the corresponding band of pure water. It is interpreted to be due to those OH groups which are not associated with the anion. Components A and B are not resolved in solutions of most electrolytes because the distribution of strengths of interactions of OH groups with most anions overlaps that of [Formula: see text] interactions between water molecules.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Eun Ji Choi ◽  
Younghee Yun ◽  
Seungyeon Yoo ◽  
Kyu Seok Kim ◽  
Jeong-Su Park ◽  
...  

Tinnitus patients suffer from not only auditory sensations but also physical, mental, and social difficulties. Even though tinnitus is believed to be associated with the autonomic nervous system, changes in autonomic conditions in tinnitus patients are not receiving much research attention. The aims of this study were to investigate the autonomic condition of tinnitus patients and to consider Korean medicine in the treatment of tinnitus with an evidence-based approach. We performed a retrospective chart review and compared the heart rate variability (HRV) parameters of 40 tinnitus patients (19 acute and 21 chronic) and 40 healthy controls. In tinnitus patients, the power of the high frequency component and total power of the HRV significantly decreased(P<0.05), and the low frequency to high frequency ratio significantly increased(P<0.05). There was no significant difference between the acute and chronic patients. When comparing each group with the controls, there was a tendency that the longer the duration of tinnitus was, the larger the observed HRV change was. In conclusion, tinnitus patients have vagal withdrawal and sympathetic overactivity, and chronic tinnitus more strongly affects autonomic conditions than acute tinnitus. This study provides evidence for Korean medical treatments of tinnitus, such as acupuncture and Qi-training, that cause modulation of cardiac autonomic function.


2015 ◽  
Author(s):  
Randolph F Helfrich ◽  
Christoph S Herrmann ◽  
Andreas K Engel ◽  
Till R Schneider

Cross-frequency coupling (CFC) has been suggested to constitute a highly flexible mechanism for cortical information gating and processing, giving rise to conscious perception and various higher cognitive functions in humans. In particular, it might provide an elegant tool for information integration across several spatiotemporal scales within nested or coupled neuronal networks. However, it is currently unknown whether low frequency (theta/alpha) or high frequency gamma oscillations orchestrate cross-frequency interactions, raising the question of who is master and who is slave. While correlative evidence suggested that at least two distinct CFC modes exist, namely phase-amplitude-coupling (PAC) and amplitude-envelope-correlations (AEC), it is currently unknown whether they subserve distinct cortical functions. Novel non-invasive brain stimulation tools, such as transcranial alternating current stimulation (tACS), now provide the unique opportunity to selectively entrain the low or high frequency component and study subsequent effects on CFC. Here, we demonstrate the differential modulation of CFC during selective entrainment of alpha or gamma oscillations. Our results reveal that entrainment of the low frequency component increased PAC, where gamma power became preferentially locked to the trough of the alpha oscillation, while gamma-band entrainment reduced alpha power through enhanced AECs. These results provide causal evidence for the functional role of coupled alpha and gamma oscillations for visual processing.


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