Cubic normal distribution and its significance in structural reliability

Zhao, Yan-Gang,Lu, Zhao-Hui Techno-Press 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.28 No.3

Information on the distribution of the basic random variable is essential for the accurate analysis of structural reliability. The usual method for determining the distributions is to fit a candidate distribution to the histogram of available statistical data of the variable and perform approximate goodness-of-fit tests. Generally, such candidate distribution would have parameters that may be evaluated from the statistical moments of the statistical data. In the present paper, a cubic normal distribution, whose parameters are determined using the first four moments of available sample data, is investigated. A parameter table based on the first four moments, which simplifies parameter estimation, is given. The simplicity, generality, flexibility and advantages of this distribution in statistical data analysis and its significance in structural reliability evaluation are discussed. Numerical examples are presented to demonstrate these advantages.

Estimation of load and resistance factors based on the fourth moment method

Zhao-Hui Lu,Yan-gang Zhao,Alfredo H-S. Ang 국제구조공학회 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.36 No.1

The load and resistance factors are generally obtained using the First Order Reliability Method (FORM), in which the design point should be determined and derivative-based iterations have to be used. In this paper, a simple method for estimating the load and resistance factors using the first four moments of the basic random variables is proposed and a simple formula for the target mean resistance is also proposed to avoid iteration computation. Unlike the currently used method, the load and resistance factors can be determined using the proposed method even when the probability density functions (PDFs) of the basic random variables are not available. Moreover, the proposed method does not need either the iterative computation of derivatives or any design points. Thus, the present method provides a more convenient and effective way to estimate the load and resistance factors in practical engineering. Numerical examples are presented to demonstrate the advantages of the proposed fourth moment method for determining the load and resistance factors.

Prevalence, Risk Factors, and Psychological Effects of Primary Nocturnal Enuresis in Chinese Young Adults

Hui Jie Hu,Zhen Wei Zhang,Yu Liang,Yan Yan Luo,Qi Feng Dou,Cui Ping Song,Hui Min Zhang,Ying Zhao,Guang Run Tian,Ke Zhang,Qiu Fang Mao,Jing Gui Song,Soren Rittig,Jian Guo Wen 대한배뇨장애요실금학회 2021 International Neurourology Journal Vol.25 No.1

Purpose: This study aimed to investigate the prevalence, risk factors, and effects of primary nocturnal enuresis (PNE) on physical and mental health in young adults in mainland China. Methods: An anonymous questionnaire was used to collect information including the sociodemographic characteristics, history of PNE, family history, daytime voiding symptoms, Pittsburgh Sleep Quality Index (PSQI) scores, Self-Esteem Scale (SES), and Self-Rating Depression Scale (SDS). A total of 22,500 university students from 23 provinces and 368 cities in mainland China were included. Results: In total, 21,082 questionnaires were collected, and 20,345 of them qualified for statistical analysis. The PNE prevalence was 1.17%, and the distribution of monosymptomatic nocturnal enuresis (MNE) and nonmonosymptomatic nocturnal enuresis (NMNE) was 66.1% and 33.9%, respectively. In total, 28% of respondents with PNE reported bedwetting daily, 31.6% between 1 and 7 times weekly, and 40.4% between 1 and 4 times monthly; 80% of PNE cases had no history of treatment. The prevalence of PNE in patients with a family history, frequency, urgency, urinary incontinence, and recurrent urinary tract infections was significantly higher than in those without these conditions (P<0.001). PNE was significantly correlated with the PSQI total score (sleep quality) (P=0.011). The SES score was lower and the SDS was higher (P<0.001) in the PNE group than in those without PNE. Conclusions: In mainland China, the PNE prevalence among young adults was found to be high, and PNE had significant effects on physical and mental health. Risk factors included a family history, daytime voiding symptoms, and lack of treatment.

Effectiveness of Pharmacopuncture Therapy in Adhesive Capsulitis: a Study Protocol for a Pragmatic Randomized Controlled Trial

Zhao Hui Yan,Han Chang-Hyun,Yang Changsop,Lee Yoon Jae,Ha In-Hyuk,Park Kyoung Sun 사단법인약침학회 2023 Journal of Acupuncture & Meridian Studies Vol.16 No.2

Background: Adhesive capsulitis is a progressive, idiopathic disorder that significantly impacts individuals̓ daily lives and increases their medical burden. Pharmacopuncture therapy, which combines acupuncture techniques with herbal medicine, involves injecting herbal extracts into specific acupoints. This study aims to determine the effectiveness and safety of pharmacopuncture therapy in comparison to physiotherapy (PT) for treating adhesive capsulitis. Methods: This research protocol outlines a two-arm, parallel, multi-center, pragmatic randomized controlled trial. Fifty participants will be randomly allocated to either the pharmacopuncture therapy or PT group, and they will receive 12 sessions of their respective therapies over a 6-week period. The primary outcome measure is the numeric rating scale for shoulder pain. Secondary outcomes include the visual analog scale score for shoulder pain, Shoulder Pain and Disability Index, Patients̓ Global Impression of Change score, Short Form-12 Health Survey Version 2 score, and EuroQol-5 Dimension. Statistical analysis will be conducted based on the intention-to-treat principle. Discussion: This trial may offer high-quality and reliable clinical evidence for evaluating the effectiveness and safety of pharmacopuncture therapy compared to PT in the treatment of adhesive capsulitis. Furthermore, this study will serve as a valuable guideline for practitioners when making clinical decisions and managing adhesive capsulitis.

Cubic normal distribution and its significance in structural reliability

Yan-Gang Zhao,Zhao-Hui Lu 국제구조공학회 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.28 No.3

Information on the distribution of the basic random variable is essential for the accurate analysis of structural reliability. The usual method for determining the distributions is to fit a candidate distribution to the histogram of available statistical data of the variable and perform approximate goodness-of-fit tests. Generally, such candidate distribution would have parameters that may be evaluated from the statistical moments of the statistical data. In the present paper, a cubic normal distribution, whose parameters are determined using the first four moments of available sample data, is investigated. A parameter table based on the first four moments, which simplifies parameter estimation, is given. The simplicity, generality, flexibility and advantages of this distribution in statistical data analysis and its significance in structural reliability evaluation are discussed. Numerical examples are presented to demonstrate these advantages.

Reliability-based assessment of American and European specifications for square CFT stub columns

Zhao-Hui Lu,Yan-gang Zhao,Zhi-wu Yu,Cheng Chen 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.19 No.4

This paper presents a probabilistic investigation of American and European specifications (i.e., AISC and Eurocode 4) for square concrete-filled steel tubular (CFT) stub columns. The study is based on experimental results of 100 axially loaded square CFT stub columns from the literature. By comparing experimental results for ultimate loads with code-predicted column resistances, the uncertainty of resistance models is analyzed and it is found that the modeling uncertainty parameter can be described using random variables of lognormal distribution. Reliability analyses were then performed with/without considering the modeling uncertainty parameter and the safety level of the specifications is evaluated in terms of sufficient and uniform reliability criteria. Results show that: (1) The AISC design code provided slightly conservative results of square CFT stub columns with reliability indices larger than 3.25 and the uniformness of reliability indices is no better because of the quality of the resistance model; (2) The uniformness of reliability indices for the Eurocode 4 was better than that of AISC, but the reliability indices of columns designed following the Eurocode 4 were found to be quite below the target reliability level of Eurocode 4.

Estimation of load and resistance factors based on the fourth moment method

Lu, Zhao-Hui,Zhao, Yan-Gang,Ang, Alfredo H.S. Techno-Press 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.36 No.1

The load and resistance factors are generally obtained using the First Order Reliability Method (FORM), in which the design point should be determined and derivative-based iterations have to be used. In this paper, a simple method for estimating the load and resistance factors using the first four moments of the basic random variables is proposed and a simple formula for the target mean resistance is also proposed to avoid iteration computation. Unlike the currently used method, the load and resistance factors can be determined using the proposed method even when the probability density functions (PDFs) of the basic random variables are not available. Moreover, the proposed method does not need either the iterative computation of derivatives or any design points. Thus, the present method provides a more convenient and effective way to estimate the load and resistance factors in practical engineering. Numerical examples are presented to demonstrate the advantages of the proposed fourth moment method for determining the load and resistance factors.

A Rapidly New-typed Detection of Norovirus Based on F0F1-ATPase Molecular Motor Biosensor

Zhuo Zhao,Jie Zhang,Mei-Ling Xu,Zhi-Peng Liu,Hua Wang,Ming Liu,Yan-Yan Yu,Li Sun,Hui Zhang,Hai-Yan Wu 한국생물공학회 2016 Biotechnology and Bioprocess Engineering Vol.21 No.1

In order to adapt port rapid detection of food borne norovirus, presently we developed a new typed detection method based on F0F1-ATPase molecular motor biosensor. A specific probe was encompassed the conservative region of norovirus and F0F1-ATPase within chromatophore was constructed as a molecular motor biosensor through the “ε-subunit antibody-streptomycinbiotin- probe” system. Norovirus was captured based on probe-RNA specific binding. Our results demonstrated that the Limit of Quantification (LOQ) is 0.005 ng/mL for NV RNA and also demonstrated that this method possesses specificity and none cross-reaction for food borne virus. What’s more, the experiment used this method could be accomplished in 1 h. We detected 10 samples by using this method and the results were consistent with RT-PCR results. Overall, based on F0F1-ATPase molecular motors biosensor system we firstly established a new typed detection method for norovirus detection and demonstrated that this method is sensitive and specific and can be used in the rapid detection for food borne virus.

Media Optimization for Laccase Production by Trichoderma harzianum ZF-2 Using Response Surface Methodology

( Hui Ju Ga ),( Xiang Chu ),( Yan Wen Wang ),( Fei Zhou ),( Kai Zhao ),( Zhi Mei Mu ),( Qing Xin Liu ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.12

Trichoderma harzianum ZF-2 producing laccase was isolated from decaying samples from Shandong, China, and showed dye decolorization activities. The objective of this study was to optimize its culture conditions using a statistical analysis of its laccase production. The interactions between different fermentation parameters for laccase production were characterized using a Plackett-Burman design and the response surface methodology. The different media components were initially optimized using the conventional one-factor-at-atime method and an orthogonal test design, and a Plackett-Burman experiment was then performed to evaluate the effects on laccase production. Wheat straw powder, soybean meal, and CuSO4 were all found to have a significant influence on laccase production, and the optimal concentrations of these three factors were then sequentially investigated using the response surface methodology with a central composite design. The resulting optimal medium components for laccase production were determined as follows: wheat straw powder 7.63 g/l, soybean meal 23.07 g/l, (NH4)2SO4 1 g/l, CuSO4 0.51 g/l, Tween-20 1 g/l, MgSO4 1 g/l, and KH2PO4 0.6 g/l. Using this optimized fermentation method, the yield of laccase was increased 59.68 times to 67.258 U/ml compared with the laccase production with an unoptimized medium. This is the first report on the statistical optimization of laccase production by Trichoderma harzianum ZF-2.

Reviews on the Paleozoic-Mesozoic granitoids and sedimentary rocks in North Korea

Yan-Bin Zhang,Ming-Guo Zhai,Fu-Yuan Wu,Xiao-Hui Zhang,Qiu-Li Li,Peng Peng,Lei Zhao,Li-Gang Zhou 대한지질학회 2021 지질학회지 Vol.57 No.4