Value Of Different Levels Research Articles

LDH LEVEL IN ACUTE ORGANOPHOSPHORUS POISONING AND ITS RELATION WITH SEVERITY AND MORTALITY: A TERTIARY CARE HOSPITAL EXPERIENCE

Background: Organophosphorus compounds have been widely used for a few decades in agriculture for crop protection and pest control. In India Organophosphorus poisoning is the most common. The objective of our study was to measure the LDH Level in acute organophosphorus poisoning
 Methods: This study was conducted among minimum 100 patients acute organophosphorus poisoning admitted in Casualty ward, MICU and attending medical ward of JLN hospital, Ajmer during Aug 2018 to July 2020. Serum lactate dehydrogenase estimation by spectrophotometric analysis using Beckman Coalter AU 680
 Results: These were significantly higher among deaths on day 1 and 3(810±372.99 and 1027.09±458.26, respectively) in comparison to survivors on day 1 and 3 (538.18±300.42 and 365.19±175.49, respectively). Significant difference was found between mean values of different levels of severity of LDH on day 1 and 3.
 Conclusion: In conclusion, this study found that Serum LDH can be used as biomarker in diagnosis or stratifying severity of acute OP poisoning, as it is cheap and easily available, especially in developing countries. Serial measurements of serum LDH levels in acute OP poisoning can predict the prognosis.
 Keywords: LDH, OP poisoning, Severity

A Combinatorial Deep Learning Structure for Precise Depth of Anesthesia Estimation From EEG Signals.

Electroencephalography (EEG) is commonly used to measure the depth of anesthesia (DOA) because EEG reflects surgical pain and state of the brain. However, precise and real-time estimation of DOA index for painful surgical operations is challenging due to problems such as postoperative complications and accidental awareness. To tackle these problems, we propose a new combinatorial deep learning structure involving convolutional neural networks (inspired by the inception module), bidirectional long short-term memory, and an attention layer. The proposed model uses the EEG signal to continuously predicts the bispectral index (BIS). It is trained over a large dataset, mostly from those under general anesthesia with few cases receiving sedation/analgesia and spinal anesthesia. Despite the imbalance distribution of BIS values in different levels of anesthesia, our proposed structure achieves convincing root mean square error of 5.59 ± 1.04 and mean absolute error of 4.3 ± 0.87, as well as improvement in area under the curve of 15% on average, which surpasses state-of-the-art DOA estimation methods. The DOA values are also discretized into four levels of anesthesia and the results demonstrate strong inter-subject classification accuracy of 88.7% that outperforms the conventional methods.

Solving fuzzy multiobjective linear bilevel programming problems based on the extension principle

Fuzzy multiobjective linear bilevel programming (FMOLBP) problems are studied in this paper. The existing methods replace one or some deterministic model(s) instead of the problem and solve the model(s). Doing this work, we lose much information about the compromise decision, and it does not make sense for the uncertain conditions. To overcome the difficulties, Zadeh’s extension principle is applied to solve the FMOLBP problems. Two crisp multiobjective linear three-level programming problems are proposed to find the lower and upper bound of its objective values in different levels. The problems are reduced to some linear optimization problems using one of the scalarization approaches, called the weighting method, the dual theory, and the vertex enumeration method. The lower and upper bounds are estimated by the resolution of the corresponding linear optimization problems. Hence, the membership functions of compromise objective values are produced, which is the main contribution of this paper. This technique is applied for the problem for the first time. This method applies all information of a fuzzy number and does not estimate it by a crisp number. Hence, the compromise decision resulted from the proposed method is consistent with reality. This point can minimize the gap between theory and practice. The results are compared with the results of existing approaches. It shows the efficiency of the proposed approach.

Growth performance, carcass characteristics, digestibility and economics of broiler production fed diets containing different levels of camel rumen content in the Semi- Arid Zone of Nigeria

The feeding value of different levels of camel rumen content in broiler diet was investigated using 150 Hover marshal broiler chickens from one-day to 63-days of age. The birds were randomly allotted to five /diets with two replicates of 15 birds each. The diets (starter and finisher) were formulated to contain 0, 5, 10, 15 and 20% camel rumen content in T1, T2, T3, T4 and T5 diets respectively. At nine week of the experiment three birds per replicate were selected for carcass measurement. The backs, hearts, kidneys, lungs, liver and spleen were not significantly (P > 0.05) different among the treatment groups while other parameters were significantly (P<0.05) different among the treatment groups. At week eight of the experiment three birds per replicate were selected for digestibility study. At the starter stage, the daily feed intake and daily weight gain were significantly (P<0.05) different among the treatment groups but only the feed conversion ratio was not affected (P>0.05) by the camel rumen content (CRC) in the diets. However, broiler chicks fed CRC T1 (0%), T2 (5%), T3 (10%) and T4 (15%) had better daily weight gain than those fed T5 (20%). During the finisher stage, all the growth parameters were not affected (P>0.05%) by CRC except final body weight which was affected (P<0.05) by the test material. Economic of production showed that CRC diets were not profitable in terms of cost of feed per kg weight gain during the starter stage. At finisher stage the cost of feed per kg weight gain were better in broilers chicken fed CRC based-diets. The result of the experiment showed that camel rumen content can replace maize and groundnut cake up to 15% level without deleterious effect on the roductive performance of broiler chicks.However, at finisher stage up to20%dietarymaize and groundnut cake could be replaced with CRC without adverse effect on the growth performance, carcass parameters, digestibility and economics of production.

Seismic response evaluation of structures using discrete wavelet transform through linear analysis

In this article, the discrete wavelet transform (DWT) has been used to construct the wavelet response spectrum analysis (WRSA) of structures in the linear elastic zone. For this purpose, the elastic response spectra of different single degree of freedom (SDOF) systems are studied for different beam-to-column stiffness ratios. Initially, using the DWT, the records of near- and far-field earthquakes are decomposed into three levels. Finally, the linear response spectra of the SDOF systems are constructed subjected to the main and decomposed earthquakes. In the end, the error values for different levels of decompositions are computed using the considered error estimation criteria. The results show that using WRSA, the computational volume of time history analysis has reduced since the consuming time to perform the analysis has significantly reduced (e.g., it reduces the computational cost by almost 50% in the first decomposition level). In addition, the results indicate that the highest error values occur for the structures with a beam-to-column stiffness ratio equal to one. However, for the structures with ratios of greater than one, the values of error reduced. For the conventional structures where the ratio is less than one and the natural period is in the range of 0.5 s and 10 s, the error values are <10%. Results also revealed that, except for the structures with beam-to-column stiffness ratio equal to one, in all the other cases, the values of error for the structure subjected to the near-field earthquakes are less than those of the far-field ones. Furthermore, the results obtained from the SDOF system analysis were investigated for several multi-degree-of-freedom structures with a linear behavior.

Analysis and Optimization of Tooth Surface Contact Stress of Gears with Tooth Profile Deviations, Meshing Errors and Lead Crowning Modifications Based on Finite Element Method and Taguchi Method

Based on the three-dimensional (3D) finite element method (FEM) and Taguchi method (TM), this paper analyzes the tooth surface contact stress (TSCS) of spur gears with three different influence factors: tooth profile deviations (TPD), meshing errors (ME) and lead crowning modifications (LCM), especially researching and analyzing the interactions between TPD, ME and LCM and their degree of influence on the TSCS. In this paper, firstly, a 3D FEM model of one pair of engaged teeth is modeled and the mesh of the contact area is refined by FEM software. In the model, the refined area mesh and the non-refined area mesh are connected by multi-point constraint (MPC); at the same time, in order to save the time of the FEM solution on the premise of ensuring the solution’s accuracy, the reasonable size of the refined area is studied and confirmed. Secondly, the TSCS analyses of gears with one single influence factor (other factors are all ideal) are carried out. By inputting the values of different levels of one single factor into the FEM model, especially using the real measurement data of TPD, and conducting the TSCS analysis under different torques, the influence degree of one single factor on TSCS is discussed by comparing the ideal model, and it is found that when the influence factors exist alone, each factor has a great influence on the TSCS. Finally, through TM, an orthogonal test is designed for the three influence factors. According to the test results, the interactions between the influence factors and the influence degree of the factors on the TSCS are analyzed when the three factors exist on the gear at the same time, and it is found that the TPD has the greatest influence on the TSCS, followed by the lead crowning modified quantity. The ME is relatively much small, and there is obvious interaction between ME and LCM. In addition, the optimal combination of factor levels is determined, and compared with the original combination of a gear factory, we see that the contact fatigue performance of the gear with the optimal combination is much better. The research of this paper has a certain reference significance for the control of TPD, ME and LCM when machining and assembling the gears.

Evaluation of the Perinodular Stiffness Potentially Predicts the Malignancy of Thyroid Nodules.

To evaluate the surrounding tissue stiffness measured by sound touch elastography for differential diagnosis of thyroid nodules (TNs). Thirty-nine benign and 90 malignant TNs were included in this study. The conventional ultrasound features, the maximum Young modulus value of the stiffness of the TNs (recorded as E), and the stiffness of the 0.5-, 1.0-, 1.5-, and 2.0-mm perinodular regions of the TNs (recorded as Eshell0.5 , Eshell1.0 , Eshell1.5 , and Eshell2.0 , respectively) were prospectively analyzed and compared to histopathologic results. The abundance of collagen fibers at various widths in the perinodular regions of the TNs was evaluated by Masson staining and ImageJ software (National Institutes of Health, Bethesda, MD). The fibrous structures in the perinodular regions of the TNs were classified. The various Eshell values of malignant TNs were significantly higher than those of benign TNs (P < .001 for all). Eshell0.5 correlated highly with E in the malignant TNs and in all samples (r = 0.722 and 0.772; P < .001 for both). Eshell2 yielded the highest area under the receiving operating characteristic curve value (0.96) for the differential diagnosis of TNs. The abundance of collagen fibers in the 2-mm perinodular region of the TNs was closely correlated with Eshell2 in the malignant TNs and in all samples (r =0.729 and 0.867; P < .001). The Eshell2 values for different levels of disorder of the tissue surrounding TNs were significantly different (P < .01 for all). Perinodular stiffness measured by sound touch elastography improved the diagnostic accuracy in TNs.

The Interaction Effect between ESG and Green Innovation and Its Impact on Firm Value from the Perspective of Information Disclosure

Few studies have been conducted on whether the coexistence of green innovation and corporate social responsibility (CSR) has a favorable interaction effect on firm value. This interaction effect is of great significance for enterprises balancing resource allocation between two factors in the future. Meanwhile, information disclosure can reflect the efforts of enterprises in taking on CSR. Therefore, taking China’s listed companies as an example, this paper studies the interaction effect of CSR after being divided into the three different dimensions of environment, society, and governance (ESG) and green innovation on firm value. The quantile regression method can reflect the impact of CSR and green innovation on the firm value of different levels. The study finds that: (1) green innovation can promote the improvement of medium- and high-level firm value; (2) only the disclosure of environmental and social information can have a positive impact on firm value; (3) the interaction effect between green innovation and social disclosure on firm value is a substitution effect, which will gradually weaken with the increase of firm value. This paper proposes that relevant departments should guide green funds into enterprises with capital constraints to alleviate the issue of fund crowding into CSR and green innovation.

THE SOCIOCULTURAL MODEL OF CREATIVITY: HOW IT CAN EXPLAIN THE SIGNIFICANCE OF MULTIPLE FORMS OF LATE-LIFE CREATIVITY

Creativity in later life comes in many forms, ranging from everyday creativity to genius-level creativity, and including both newly learned creative activities and life-long creative hobbies. Previous psychosocial models of creativity have had limited utility in explaining the significance of late life creativity. Glaveanu’s sociocultural model has not been previously applied to older adults, but its inclusiveness makes it supremely useful for describing the range of creative activities and products in context. Creativity, according to Glaveanu, involves five interconnected components: actors, actions, artifacts, audiences, and affordances, which can be used to describe many different points along continuum of creative activities. The sociocultural model recognizes the value of different levels of creativity, including culturally-specific crafts, practice and learning new skills, the role of large and small audiences for creativity, and the connection of creativity and community. Glaveanu’s model will be discussed in the context of Erikson’s theory of late life development.

The evaluation on neural status of cervical spinal cord in normal and Hirayama disease using diffusion tensor imaging.

To explore the changes in diffusion tensor imaging (DTI) parameters in cervical spinal cord in Hirayama disease (HD) patients and healthy volunteers and to compare these parameters between cervical flexion and neutral positions in HD patients. Seventeen male patients with HD and eleven healthy young males were included to receive DTI scans in cervical flexion and neutral positions. The FA and ADC values of different levels were measured based on the region of interest drawn on the mid-sagittal plane. The dynamic compressed level's parameters were defined as the lowest and the second lowest FA and the highest and the second highest ADC, respectively. The clinical assessment of patients was obtained using their disabilities of the arm, shoulder and hand (DASH) scores. For the HD patients, the FA values in the cervical flexion position were lower and the ADC values were much higher than those in the cervical neutral position. Compared with the controls, the ADC values were significantly higher in the lower levels (C5/6-C7/T1) and the FA values obviously lower at C7/T1 in HD patients in cervical neutral position. The FA and ADC values of the dynamic compressed level in HD patients deviated significantly from the average of the lower levels in controls. Both the FA and ADC values of the dynamic compressed level correlated with the DASH scores (FA, R2 = 0.520, P = 0.001; ADC, R2 = 0.421, P = 0.005). DTI parameters can support a hypothesis of dynamic cervical flexion compression and noninvasively reveal the neural status of HD patients. These slides can be retrieved under Electronic Supplementary Material.

BER analysis of concatenated levels of encoding in GFDM system using labview

&lt;p&gt;All the devices are interconnected each other in digital form, for different applications the input data is encoded for error correcting and detecting purpose. The paper describes the transmission of QAM signals with two level encoded stages, i.e. convolutional and hamming coded GFDM system with 256-point IFFT at transmitter and FFT at the receiver using LABVIEW software. GFDM is a non-orthogonal, digital multicarrier transmission scheme which digitally implements the classical filter bank approach. GFDM transmits a block of frame composed by M time slots with K subcarriers. The higher order QAM is used because of transmitting more data but is less reliable when compared to lower order QAM. Based on GFDM specifications for the IEEE 802.11, latest 5G physical layer standards, the coding is provided by ½ rate encoder at the input side, and Maximum Likelihood decoder at the receiver side is used. The standard convolution code (7, [171, 133]), is used as encoder for the GFDM system. The GFDM complex values are displayed in the front panel, along with FFT and power spectrum is plotted for GFDM signal. The array of input bits and output bits are shown with green colour LED’s. The van de Beek algorithm is used at the receiver for maximum likelihood detection acts as convolutional decoder of GFDM signal. Next the signal is subjected to remove cyclic prefix and zero padding and applied to channel estimation algorithm. The un-equalized data and equalized data graph is shown in the front panel, before and after channel estimation VI. With BER VI available in the LABVIEW the data is normalized and its response is plotted with respect to SNR. BER values for different levels of encoders have shown in table for SNR values. This paper concludes the 32.91% improvement in BER for two levels of concatenated codes.Thus the GFDM signal outperforms the OFDM signal interms of BER for series levels of coding using labVIEW software.&lt;/p&gt;

Assessing the value of eHealth for bariatric surgery (BePatient trial): study protocol for a randomized controlled trial

BackgroundThe expansion of digital devices and widespread access to the Internet has opened up opportunities to provide patients with more personal information. It can be hypothesized that eHealth in addition to standard care could enhance clinical outcomes such as increased weight loss, co-morbidity reduction, and commitment to the program. The beneficial value of incorporating eHealth applications as standard postoperative care is yet to be established. In this trial, the value of different levels of eHealth are assessed.Methods/designTwo hundred adult patients with a body mass index (BMI) ≥ 40 kg/m2, or ≥ 35 kg/m2 with obesity-related co-morbidity, undergoing sleeve gastrectomy or gastric bypass will be enrolled in this randomized controlled trial. Patients will be randomly assigned to one of the groups: receiving standard care (control group, n = 100); have access to an online eHealth platform in addition to the previous group (online group, n = 50); or receive wireless monitoring devices in addition to previous groups (device group, n = 50). The total follow-up period is two years postoperatively. Primary outcome is weight loss in terms of BMI. Secondary outcomes include: quality of life; return-to-work time; co-morbidity reduction; additional contacts; and ease of use of devices.DiscussionIn this trial, the value of different levels of eHealth will be assessed. This addresses an important aspect of a changing healthcare environment.Trial registrationTrialregister.nl, NTR6827. Retrospectively registered on 19 November 2017. http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=6827.

The COSMAM TRIAL a prospective cohort study of quality of life and cosmetic outcome in patients undergoing breast conserving surgery

BackgroundCosmetic result in breast cancer surgery is gaining increased interest. Currently, some 30–40% of the patients treated with breast conserving surgery (BCS) are dissatisfied with their final cosmetic result. In order to prevent disturbing breast deformity oncoplastic surgical techniques have been introduced. The extent of different levels of oncoplastic surgery incorporated in breast conserving surgery and its value with regard to cosmetic outcome, patient satisfaction and quality of life remains to be defined. The aim of this prospective cohort study is to investigate quality of life and satisfaction with cosmetic result in patients with breast cancer, undergoing standard lumpectomy versus level I or II oncoplastic breast conserving surgery.MethodsFemale breast cancer patients scheduled for BCS, from 18 years of age, referred to our outpatient clinic from July 2015 are asked to participate in this study. General, oncologic and treatment information will be collected. Patient satisfaction will be scored preceding surgery, and at 1 month and 1 year follow up. Photographs of the breast will be used to score cosmetic result both by the patient, an independent expert panel and BCCT.Core software. Quality of life will be measured by using the BREAST-Q BCT, EORTC-QLQ and EQ-5D-5 L questionnaires.DiscussionThe purpose of this prospective study is to determine the clinical value of different levels of oncoplastic techniques in breast conserving surgery, with regard to quality of life and cosmetic result. Analysis will be carried out by objective measurements of the final cosmetic result in comparison with standard breast conserving surgery. The results of this study will be used to development of a clinical decision model to guide the use oncoplastic surgery in future BCS.Trial registrationCentral Commission of Human Research (CCMO), The Netherlands: NL54888.015.15.Medical Ethical Commission (METC), Maxima Medical Centre, Veldhoven, The Netherlands: 15.107.Dutch Trial Register: NTR5665, retrospectively registered, 02-25-2016.

Prognostic Value of the Glasgow Prognostic Score or Modified Glasgow Prognostic Score for Patients with Colorectal Cancer Receiving Various Treatments: a Systematic Review and Meta-Analysis

Background/Aims: Increasing evidence indicates that the systemic inflammatory response plays a vital role in carcinogenesis. The Glasgow Prognostic Score or modified Glasgow Prognostic Score (GPS/mGPS) is a novel inflammatory indicator which consists of CRP and albumin. Here, we performed a meta-analysis to evaluate the prognostic value of the GPS/ mGPS in patients with colorectal cancer (CRC) and to assess its consistency in different CRC therapies. Methods: The electronic databases PubMed, Embase, Scopus, Web of Science, and Cochrane Library were searched from inception through December 2017 for the association between the GPS/mGPS and clinical outcomes. Study characteristics and prognostic data were extracted from each relevant study. Overall survival (OS) and cancer-specific survival (CSS) were considered the primary outcomes, and hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated. The quality of each study was pooled using the random-effects Mantel-Haenszel model. Finally, subgroup analyses were performed to detect the heterogeneity of different CRC treatments. Results: Thirty-four studies, with a combined total of 8834 patients, were eligible for this meta-analysis. Data on OS and CSS were available in 23 and 22 studies, respectively. By comparing the prognostic values of different levels of the GPS in CRC patients, the summary HRs for OS and CSS were 2.18 (95% CI 1.83-2.60) and 1.82 (95% CI 1.57-2.11), respectively. According to the different tumor stages, the subgroup analyses were stratified by different treatments, including curative or palliative therapy. The results robustly confirmed the prognostic role of the GPS/mGPS. Conclusion: Our results suggest that the GPS/mGPS is a novel and effective prognostic indicator for the OS and CSS of patients with CRC.

An adaptive background extraction method in traffic scenes

This paper presents an adaptive background extraction method in traffic scenes. Based on running average method, the proposed method uses the hierarchical learning factor which has different values in different levels to extract background. Traditionally, the running average method uses a fixed learning factor. It has some shortcomings: if the value of learning factor taken is too large, ghosts are prone to occur in the background learning process; if the value is too small, the speed of background extraction will be slow. In the proposed method, the value of image texture entropy is used to measure the convergence degree of background. According to the convergence degree, the learning factors are selected in an adaptive manner. Experiments prove that the proposed method can overcome the above shortcomings of traditional running average method and can faster extract the background without ghosts. The background composition curve analysis shows that this method is reasonable due to reasonable component distribution without excessive reliance on certain video frames. In addition, the proposed method is compared with some state-of-the-art methods. The comparison shows that our method has high detection accuracy and computation speed.

Valuation of measurement data for low voltage network expansion planning

The introduction of electric vehicles and photovoltaics is changing the residential electricity consumption. Distribution network operators (DNO) are investing in an advanced metering infrastructure (AMI) to enable cost reduction through smart grid applications. The DNO also benefits from the additional measurement data the AMI gives for the network planning process. The availability of AMI data can be limited by the cost of communication and by privacy concerns. To determine the social welfare of an AMI, the economic gains should be estimated. For the planning of the low voltage (LV) network, a method for determining the value of an AMI still needs to be developed. Therefore, a planning methodology which allows various levels of measurement data availability has been developed. By applying this approach the value of different levels of AMI from an LV-network planning perspective can be determined. To illustrated the application of this approach a case study for the LV-network of a Dutch DNO is performed. The results show that an increase in measurement data can lead to €49-254 lower LV-network reinforcement costs. A detailed analysis of the results shows that already 50% of the possible cost reduction can be achieved if only 65% of the households have AMI data available.

Establishment and effects of the new nursing performance appraisal system

Objective To establish a new nursing performance appraisal system to solve the problem of low efficacy, and to explore its effect on stabilizing the clinical nursing team. Methods Based on the position management, nursing performance was evaluated separately, and a new appraisal system was established to assess nurses′ workload, care quality, nursing risk, experiences, age, post, and shift, etc. Results After implementing the new appraisal system, the goal of synchronizing the workload, job risk, and efficacy was mostly achieved. The pooled increase of nursing performance for the whole 42 inpatient areas was 24.64%. The improvement in the infectious disease department had the greatest increase of 77.8% and the pooled increase for other wards was 19.06%. Unfortunately, six departments showed poorer performance. Conclusions The new nursing performance appraisal system can reflect the value of different levels of nurses and can ensure their working efficacy and enthusiasm. Key words: Nursing management; Position management; Performance appraisal system; Reform

Systemic Lisbon Battery: Normative Data for Memory and Attention Assessments.

BackgroundMemory and attention are two cognitive domains pivotal for the performance of instrumental activities of daily living (IADLs). The assessment of these functions is still widely carried out with pencil-and-paper tests, which lack ecological validity. The evaluation of cognitive and memory functions while the patients are performing IADLs should contribute to the ecological validity of the evaluation process.ObjectiveThe objective of this study is to establish normative data from virtual reality (VR) IADLs designed to activate memory and attention functions.MethodsA total of 243 non-clinical participants carried out a paper-and-pencil Mini-Mental State Examination (MMSE) and performed 3 VR activities: art gallery visual matching task, supermarket shopping task, and memory fruit matching game. The data (execution time and errors, and money spent in the case of the supermarket activity) was automatically generated from the app.ResultsOutcomes were computed using non-parametric statistics, due to non-normality of distributions. Age, academic qualifications, and computer experience all had significant effects on most measures. Normative values for different levels of these measures were defined.ConclusionsAge, academic qualifications, and computer experience should be taken into account while using our VR-based platform for cognitive assessment purposes.

Evaluation of Performance Measures for Two-Lane Intercity Highways under Mixed Traffic Conditions

AbstractTraffic performance of a highway is expressed in terms of level of service (LOS). It is a major input to important decisions on public fund investments. Because of its unique operational characteristics, evaluation of traffic performance on two-lane highways is a critical task. This research examines the applicability of various performance measures for two-lane highways under mixed traffic conditions and assigns threshold values for different levels of service based on the best performance measure observed. Graphical and statistical analyses are carried out among the six most popular performance measures and traffic volume, but none of the considered measures are found to be reliable. A new parameter, number of followers (NF), which is defined as the number of vehicles traveling with a gap less than 2.6 s, is found to have good correlation with traffic volume but it does not reflect the true congestion conditions of a roadway. Therefore, the NF is further modified to the number of followers as a ...

Noise reduction of nuclear magnetic resonance (NMR) transversal data using improved wavelet transform and exponentially weighted moving average (EWMA)

NMR logging and core NMR signals acts as an effective way of pore structure evaluation and fluid discrimination, but it is greatly contaminated by noise for samples with low magnetic resonance intensity. Transversal relaxation time (T2) spectrum obtained by inversion of decay signals intrigued by Carr–Purcell–Meiboom–Gill (CPMG) sequence may deviate from the truth if the signal-to-noise ratio (SNR) is imperfect. A method of combing the improved wavelet thresholding with the EWMA is proposed for noise reduction of decay data. The wavelet basis function and decomposition level are optimized in consideration of information entropy and white noise estimation firstly. Then a hybrid threshold function is developed to avoid drawbacks of hard and soft threshold functions. To achieve the best thresholding values of different levels, a nonlinear objective function based on SNR and mean square error (MSE) is constructed, transforming the problem to a task of finding optimal solutions. Particle swarm optimization (PSO) is used to ensure the stability and global convergence. EWMA is carried out to eliminate unwanted peaks and sawtooths of the wavelet denoised signal. With validations of numerical simulations and experiments, it is demonstrated that the proposed approach can reduce the noise of T2 decay data perfectly.