Intelligent fault diagnosis methods toward gas turbine: A review

Fault diagnosis plays a significant role in conducting condition-based maintenance and health management for gas turbines(GTs) to improve reliability and reduce costs. Various diagnosis methods developed by modeling engine systems or certain components implement faults detection and diagnosis based on the measurement of systemic parameters deviations. However, these conventional model-based methods are hindered by limitations of inability to handle the nonlinear nature, measurement uncertainty, fault coupling and other implementing problems. Recently, the development of artificial intelligence algorithms has provided an effective solution to the above problems, triggering broad researches for data-driven fault diagnosis methods with better accuracy,dynamic performance, and universality. This paper presents a systematic review of recently proposed intelligent fault diagnosis methods for GT engines, according to the classification of shallow learning methods, deep learning methods and hybrid intelligent methods. Moreover, the principle of typical algorithms, the evolution of enhanced methods, and the assessment of pros and cons are summarized to conclude the present status and look forward to the future in the field of GT fault diagnosis. Possible directions for development in method validation, information fusion, and interpretability of intelligent diagnosis methods are concluded in the end to provide insightful concepts for scholars in related fields.

A case of 9p deletion syndrome with congenital infantile glaucoma,effective method of diagnosis,and treatment

Dear Editor,I am Dr.Jia X from the Department of Ophthalmology,Second Xiangya Hospital,Central South University,Changsha,China.I write to present a rare case report of 9p deletion syndrome with congenital infantile glaucoma in an infant,accompanying with an effective method of both diagnosis and treatment.

Rapid and Visualized Detection Method of Canine Parvovirus Using Loop-Mediated Isothermal Amplification

[Objective] To develop a rapid and visualized detection method using loop-mediated isothermal amplification （LAMP）, improve the detection rate of canine parvovirus （CPV） and reduce the testing cost. [ Method] According to the conserved regions of the VP2 gene of CPV, six primers were designed to amplify the special DNA sequences by LAMP. In addition, the reaction conditions of LAMP were optimized, and the sensitivity, specificity, repeatability and stability were verified. [ Result] The optimal reaction time of the LAMP method for CPVwas 60 min. The products obtained by LAMP had high specificity without cross-reaction with other generic viruses. The sensitivity of the LAMP was 100 times higher than that of PCR. [ Conclusion] The LAMP method for detecting CPV has high practical value. It has many advantages such as high specificity, high sensitivity, simple operation, low cost and rapid analysis, and it does not require special equipment. Therefore, this method is more suitable for the detection of CPV.

Comparison of Four Diagnostic Tests Methods for the Detection of Dengue Virus Non-Structural-1 Antigen and IgM/IgG Antibodies

Objectives: Dengue virus (DENV) infection is a mosquito-borne disease that stands out as one of the major public health issues and has a wide-ranging geographical distribution throughout the tropics and subtropics. The general alarming increase in the number of cases over the last two decades can be attributed to an extent by the change in national practices to keeping records and reporting dengue to the Ministries of Health, and WHO. Dengue diagnosis is routinely carried out by detection of dengue virus (DENV) antigen NS1 (Non-structural Antigen 1) and/or anti-DENV IgM/IgG antibodies using enzyme-linked immunosorbent assays (ELISAs) and rapid diagnostic tests (RDTs). This study compared the performance of three RDTs and one ELISA used for dengue diagnosis in southeastern, Nigeria. Design: This study adopted a cross-sectional design that included prospective hospital-based surveillance of cases among febrile participants attending two major health facilities within the southeastern region of Nigeria. In this study, 338 HIV-infected participants from two teaching hospitals in Nigeria’s southeast were systematically tested for Dengue with four methods: NS1 RDT, IgG RDT, IgM RDT, and NS1 ELISA. Their specificities and sensitivities were compared, as well as their level of concordance. Their respective performances were also evaluated using the Receivers Operational curve (ROC). Results: Out of the 338 patients, the dengue prevalence from the four dengue diagnostic methods Dengue virus NS1 ELISA, NS1 RDT, IgM and IgG seropositivity were 8.9%, 0.6%, 5.6%, and 8.0%, respectively. The Dengue IgM RDT test indicated 36.8% sensitivity, 92.8% specificity, the IgG anti-dengue specific test indicated 29.6% sensitivity, 92.9% specificity and the dengue NS1 RDT test indicated 3.3% sensitivity, 99.4% specificity when compared with the Dengue NSI Elisa test method as a reference method. Conclusion: The use of NSI ELISA for DENV diagnosis showed good performance and the RDTs showed, to an extent, reliable results compared with ELISA. However, diagnostic laboratories should be aware of performance variations across tests and the possibilities of cross-reactivity that may affect results.

Research Methods and Essay Writing Analysis of MBA Dissertation

With the vigorous development of innovation and entrepreneurship in China,a large number of managers of innovation and entrepreneurship enterprises are studying for MBA degree.The enrollment scale of the MBA program is expanding.In order to improve the quality of MBA dissertation and promote the sustainable and healthy development of MBA education,based on the author's years of MBA teaching experience and dissertation writing guidance experience,this paper introduces three research methods of dissertation writing skills:case study method,enterprise diagnosis method and survey research method,and analyzes five steps of MBA dissertation writing,which can be used as a reference for MBA(EMBA)students to improve their dissertation writing level.

Improved CICA Algorithm Used for Single Channel Compound Fault Diagnosis of Rolling Bearings

A Compound fault signal usually contains multiple characteristic signals and strong confusion noise, which makes it difficult to separate week fault signals from them through conventional ways, such as FFT-based envelope detection, wavelet transform or empirical mode decomposition individually. In order to realize single channel compound fault diagnosis of bearings and improve the diagnosis accuracy, an improved CICA algorithm named constrained independent component analysis based on the energy method （E-CICA） is proposed. With the approach, the single channel vibration signal is firstly decomposed into several wavelet coefficients by discrete wavelet transform（DWT） method for the purpose of obtaining multichannel signals. Then the envelope signals of the reconstructed wavelet coefficients are selected as the input of E-CICA algorithm, which fulfills the requirements that the number of sensors is greater than or equal to that of the source signals and makes it more suitable to be processed by CICA strategy. The frequency energy ratio（ER） of each wavelet reconstructed signal to the total energy of the given synchronous signal is calculated, and then the synchronous signal with maximum ER value is set as the reference signal accordingly. By this way, the reference signal contains a priori knowledge of fault source signal and the influence on fault signal extraction accuracy which is caused by the initial phase angle and the duty ratio of the reference signal in the traditional CICA algorithm is avoided. Experimental results show that E-CICA algorithm can effectively separate out the outer-race defect and the rollers defect from the single channel compound fault and fulfill the needs of compound fault diagnosis of rolling bearings, and the running time is 0.12% of that of the traditional CICA algorithm and the extraction accuracy is 1.4 times of that of CICA as well. The proposed research provides a new method to separate single channel compound fault signals.

Advances in Animal Toxoplasmosis

Toxoplasmosis is a worldwide intracellular parasite disease of natural focus caused by Toxoplasma gondii,which has become one of the most important zoonoses seriously endangering the livestock industry development and socio-economic development in the world.In this paper,advances in the epidemiological characteristics of toxoplasmosis,detection and diagnosis of toxoplasmosis,development of T.gondii vaccines were summarized,which provided scientific basis for the control and treatment of T.gondii infection.

Nonfunctional bladder paraganglioma misdiagnosed as hemangioma:A case report

BACKGROUND Paraganglioma of the urinary bladder(PUB)is a nonepithelial tumor of the bladder that is also known as bladder pheochromocytoma.The incidence of nonfunctional paraganglioma of the urinary bladder is rare in clinical practice.CASE SUMMARY A case of nonfunctional paraganglioma of the urinary bladder diagnosed and treated in our hospital is reported herein.A 2.5 cm×2.1 cm moderate-echo mass protruding into the right anterior wall of the bladder was incidentally found during transvaginal color Doppler ultrasound examination.Based on a contrastenhanced computed tomography scan of the bladder,the right anterior wall of the bladder was considered to present a hemangioma.The patient underwent laparoscopic partial resection of the bladder wall in our hospital,and pathological results showed paraganglioma of the bladder.At present,we have followed up with the patient for half a year,and there has been no recurrence of the tumor.CONCLUSION The imaging patterns of PUB and bladder hemangioma are similar.In clinical practice,the possibility of PUB should be considered for a single wide-based isoechoic mass in the bladder,especially functional PUB may cause some adverse effects during surgery.

巨大儿201例临床分析

目的探讨巨大儿的临床特征及产科处理,减少母婴并发症。方法选择我院近4年来分娩的201例巨大儿,对其产前诊断、分娩方式与新生儿情况进行分析。结果剖宫产与阴道分娩出血情况比较差异有显著性(P<0.05);剖宫产组较阴道分娩组新生儿窒息及肩难产的机会明显降低,差异有极显著性(P<0.01)。结论应重视巨大儿的产前诊断。巨大儿的孕妇应根据不同的临床情况选择合适的分娩方法,应适当放宽剖宫产指征,以减少母婴损伤,避免医疗纠纷。

Current Status and Challenge of Pseudorabies Virus Infection in China

Pseudorabies(PR),also called Aujeszky's disease,is a highly infectious disease caused by pseudorabies virus(PRV).Without specific host tropism,PRV can infect a wide variety of mammals,including pig,sheep,cattle,etc.,thereby causing severe clinical symptoms and acute death.PRV was firstly reported in China in 1950s,while outbreaks of emerging PRV variants have been documented in partial regions since 2011,leading to significant economic losses in swine industry.Although scientists have been devoting to the design of diagnostic approaches and the development of vaccines during the past years,PR remains a vital infectious disease widely prevalent in Chinese pig industry.Especially,its potential threat to human health has also attracted the worldwide attention.In this review,we will provide a summary of current understanding of PRV in China,mainly focusing on PRV history,the existing diagnosis methods,PRV prevalence in pig population and other susceptible mammals,molecular characteristics,and the available vaccines against its infection.Additionally,promising agents including traditional Chinese herbal medicines and novel inhibitors that may be employed to treat this viral infection,are also discussed.