• Title/Summary/Keyword: Multivariable Analysis

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Probabilistic computation of the structural performance of moment resisting steel frames

  • Ceribasi, Seyit
    • Steel and Composite Structures
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    • v.24 no.3
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    • pp.369-382
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    • 2017
  • This study investigates the reliability of the performance levels of moment resisting steel frames subjected to lateral loads such as wind and earthquake. The reliability assessment has been performed with respect to three performance levels: serviceability, damageability, and ultimate limit states. A four-story moment resisting frame is used as a typical example. In the reliability assessment the uncertainties in the loadings and in the capacity of the frame have been considered. The wind and earthquake loads are assumed to have lognormal distribution, and the frame resistance is assumed to have a normal distribution. In order to obtain an appropriate limit state function a linear relation between the loading and the deflection is formed. For the reliability analysis an algorithm has been developed for determination of limit state functions and iterations of the first order reliability method (FORM) procedure. By the method presented herein the multivariable analysis of a complicated reliability problem is reduced to an S-R problem. The procedure for iterations has been tested by a known problem for the purpose of avoiding convergence problems. The reliability indices for many cases have been obtained and also the effects of the coefficient of variation of load and resistance have been investigated.

Training an Artificial Neural Network for Estimating the Power Flow State

  • Sedaghati, Alireza
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.275-280
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    • 2005
  • The principal context of this research is the approach to an artificial neural network algorithm which solves multivariable nonlinear equation systems by estimating the state of line power flow. First a dynamical neural network with feedback is used to find the minimum value of the objective function at each iteration of the state estimator algorithm. In second step a two-layer neural network structures is derived to implement all of the different matrix-vector products that arise in neural network state estimator analysis. For hardware requirements, as they relate to the total number of internal connections, the architecture developed here preserves in its structure the pronounced sparsity of power networks for which state the estimator analysis is to be carried out. A principal feature of the architecture is that the computing time overheads in solution are independent of the dimensions or structure of the equation system. It is here where the ultrahigh-speed of massively parallel computing in neural networks can offer major practical benefit.

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An Introduction to Logistic Regression: From Basic Concepts to Interpretation with Particular Attention to Nursing Domain

  • Park, Hyeoun-Ae
    • Journal of Korean Academy of Nursing
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    • v.43 no.2
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    • pp.154-164
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    • 2013
  • Purpose: The purpose of this article is twofold: 1) introducing logistic regression (LR), a multivariable method for modeling the relationship between multiple independent variables and a categorical dependent variable, and 2) examining use and reporting of LR in the nursing literature. Methods: Text books on LR and research articles employing LR as main statistical analysis were reviewed. Twenty-three articles published between 2010 and 2011 in the Journal of Korean Academy of Nursing were analyzed for proper use and reporting of LR models. Results: Logistic regression from basic concepts such as odds, odds ratio, logit transformation and logistic curve, assumption, fitting, reporting and interpreting to cautions were presented. Substantial shortcomings were found in both use of LR and reporting of results. For many studies, sample size was not sufficiently large to call into question the accuracy of the regression model. Additionally, only one study reported validation analysis. Conclusion: Nursing researchers need to pay greater attention to guidelines concerning the use and reporting of LR models.

Design of new sliding mode control system using discrete-time switching dynamics and its stability analysis (이산 시간 스위칭 다이나믹을 이용한 새로운 슬라이딩 모드 제어 시스템의 설계 및 안정도 해석)

  • 김동식;서호준;서삼준;박귀태
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.3
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    • pp.407-414
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    • 1996
  • In this paper we consider the variable structure control for a class of discrete-time uncertain multivariable systems where the nominal system is linear. Discrete-time switching dynamics are introduced so that a new type of state trajectories called sliding mode may exist on the sliding surface by state feedback. The quantitative analysis for the matched uncertainties will show that every response of the system with the proposed switching dynamics is bounded within small neighborhoods of the state-space origin. Also, by the similarity transformation it will be shown that the eigenvalues of the closed-loop systems are composed of those of the subsystems which govern the range-space dynamics and null-space dynamics. It will be also shown that ideal sliding mode can be obtained in the absence of uncertainties due to one-step attraction to the sliding surface regardless of initial position of states. (author). 12 refs., 2 figs.

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Factors associated with Utilization and Satisfaction of Traditional Korean Medicine in Korea: A National survey

  • Hyun, Min Kyung;Lee, Sang-Jae;Ryu, Ho Geol
    • Journal of Society of Preventive Korean Medicine
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    • v.19 no.3
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    • pp.171-178
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    • 2015
  • Objective : To assess the utilization patternsand satisfaction factors of Traditional Korean Medicine(TKM) in Korea. Method : The study design of this paper is from a nationally representative random e-mails and interview surveys. In this survey, we asked 2000 Korean adults between the ages of 20 and 69, whether they have used TKM in the past three years and if so, what were their experiences and how satisfied they were with the care they have received. Results : Sixty percent of respondents(n=1239) answered that they had used TKM in the past three years. The odds of using TKM were higher in female(OR 1.48; 95% CI 1.24-1.78) and academic backgrounds of university graduate or beyond (OR 1.27; 95% CI 1.01-1.60), and lower in unmarried person (OR 0.68; 95% CI 0.55-0.84) in the multivariable analysis. The most frequent purpose for seeking TKM and receiving treatment was to 'treat illness'.In addition, the use herbal medicine among types of TKM is statistically significant in sexual groupings.748(60.4%) among TKM users responded that they had a satisfying experience during TKM treatment. In multivariable logistic model, the odds of satisfaction from using TKM were higher in employed groups(OR 1.34; 95% CI 1.02-1.77), the reason for using of personalized medicine into TKM(OR 1.50; 95% CI 1.00-2.26). Conclusion : Korean traditional medicine doctors need to develop and provide the personalized medicine for the group of high utilization rate and satisfaction, and make strategies to disseminate TKM utilization for the group of lower utilization.

Effects of Simultaneous Bending and Heating on Characteristics of Flexible Organic Thin Film Transistors

  • Cho, S.W.;Kim, D.I.;Lee, N.E.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.470-470
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    • 2013
  • Recently, active materials such as amorphous silicon (a-Si), poly crystalline silicon (poly-Si), transition metal oxide semiconductors (TMO), and organic semiconductors have been demonstrated for flexible electronics. In order to apply flexible devices on the polymer substrates, all layers should require the characteristic of flexibility as well as the low temperature process. Especially, pentacene thin film transistors (TFTs) have been investigated for probable use in low-cost, large-area, flexible electronic applications such as radio frequency identification (RFID) tags, smart cards, display backplane driver circuits, and sensors. Since pentacene TFTs were studied, their electrical characteristics with varying single variable such as strain, humidity, and temperature have been reported by various groups, which must preferentially be performed in the flexible electronics. For example, the channel mobility of pentacene organic TFTs mainly led to change in device performance under mechanical deformation. While some electrical characteristics like carrier mobility and concentration of organic TFTs were significantly changed at the different temperature. However, there is no study concerning multivariable. Devices actually worked in many different kinds of the environment such as thermal, light, mechanical bending, humidity and various gases. For commercialization, not fewer than two variables of mechanism analysis have to be investigated. Analyzing the phenomenon of shifted characteristics under the change of multivariable may be able to be the importance with developing improved dielectric and encapsulation layer materials. In this study, we have fabricated flexible pentacene TFTs on polymer substrates and observed electrical characteristics of pentacene TFTs exposed to tensile and compressive strains at the different values of temperature like room temperature (RT), 40, 50, $60^{\circ}C$. Effects of bending and heating on the device performance of pentacene TFT will be discussed in detail.

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Association between Shammah Use and Oral Leukoplakia-like Lesions among Adult Males in Dawan Valley, Yemen

  • Al-Tayar, Badr Abdullah;Tin-Oo, Mon Mon;Sinor, Modh Zulkarnian;Alakhali, Mohammed Sultan
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.18
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    • pp.8365-8370
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    • 2016
  • Background: Shammah is a traditional form of snuff dipping tobacco (a smokeless tobacco form) that is commonly used in Yemen. Oral mucosal changes due to the use of shammah can usually be observed in the mucosal surfaces that the product touches. The aim of this study was to determine the association between shammah use and oral leukoplakia-like lesions. Other associated factors were also determined. Materials and Methods: A cross sectional study was conducted on 346 randomly selected adult males. Multi-stage random sampling was used to select the study location. After completing the structured questionnaire interviews, all the participants underwent clinical exanimation for screening of oral leukoplakia-like lesions Clinical features of oral leukoplakia-like lesion were characterized based on the grades of $Ax{\acute{e}}ll$ et al (1976). Univariable logistic regression and multivariable logistic regression were used to assess the potential associated factors. Results: Out of 346 male participants aged 18 years and older, 68 (19.7%) reported being current shammah users. The multivariable analysis revealed that age, non-formal or primary level of education, former shammah user, current shammah user, and frequency of shammah use per day were statistically associated with the presence of oral leukoplakia-like lesions [Adjusted odds ratio (AOR) = 1.03; 95% confidence interval (CI) : 1.01, 1.06; P=0.006], (AOR=8.65; 95% CI: 2.81, 26.57; P=0.001), (AOR=3.65; 95% CI: 1.40, 9.50; P=0.008), (AOR=12.99; 95% CI: 6.34, 26.59; P=0.001), and (AOR=1.17; 95% CI: 1.02, 1.36; P=0.026), respectively. Conclusions: The results revealed oral leukoplakia-like lesions to be significantly associated with shammah use. Therefore, it is important to develop comprehensive shammah prevention programs in Yemen.

Risk Factors for Poorer Breast Cancer Outcomes in Residents of Remote Areas of Australia

  • Roder, David;Zorbas, Helen;Kollias, James;Pyke, Chris;Walters, David;Campbell, Ian;Taylor, Corey;Webster, Fleur
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.1
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    • pp.547-552
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    • 2013
  • To investigate patient, cancer and treatment characteristics in females with breast cancer from more remote areas of Australia, to better understand reasons for their poorer outcomes, bi-variable and multivariable analyses were undertaken using the National Breast Cancer Audit database of the Society of Breast Surgeons of Australia and New Zealand. Results indicated that patients from more remote areas were more likely to be of lower socio-economic status and be treated in earlier diagnostic epochs and at inner regional and remote rather than major city centres. They were also more likely to be treated by low case load surgeons, although this finding was only of marginal statistical significance in multivariable analysis (p=0.074). Patients from more remote areas were less likely than those from major cities to be treated by breast conserving surgery, as opposed to mastectomy, and less likely to have adjuvant radiotherapy when having breast conserving surgery. They had a higher rate of adjuvant chemotherapy. Further monitoring will be important to determine whether breast conserving surgery and adjuvant radiotherapy utilization increase in rural patients following the introduction of regional cancer centres recently funded to improve service access in these areas.

Smoking Cessation Treatment and Outcomes in Medium to Heavy Cigarette Smokers being Treated for Cancer in Jordan

  • Hawari, Feras Ibrahim;Obeidat, Nour Ali;Ayub, Hiba Salem;Dawahrah, Sahar Sattam;Hawari, Saif Feras
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6875-6881
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    • 2013
  • Background: Studies evaluating smoking cessation treatment outcomes in cancer patients are scarce, despite smoking cessation importance in cancer care. We sought to add to the literature by evaluating smoking cessation in a challenging group of cancer patients (medium-to-heavy smokers) visiting an out-patient smoking cessation clinic (SCC) in a cancer center in Amman, Jordan. Materials and Methods: Patients smoking >9 cigarettes per day (CPD) and referred to the SCC between June 2009 and May 2012 were studied. Clinic records were reviewed to measure demographic and baseline clinical characteristics, and longitudinal (3-, 6- and 12- month) follow-up by phone/clinic visit was conducted. At each follow-up, patients were asked if they experienced medication side-effects, if they had returned to smoking, and reasons for failing to abstain. Descriptive and multivariable logistic regression analyses were performed. Results: A total of 201 smokers were included in the analysis. The 3-month abstinence was 23.4% and significantly associated with older age, being married, and presenting with lower (${\leq}10ppm$) baseline carbon monoxide (CO) levels. On a multivariable level, lower CO levels, a higher income (relative to the lowest income group), being older, and reporting severe dependence (relative to dependence reported as 'somewhat' or 'not') were significant predictors of higher odds of abstinence at three months. Reasons for failing to quit included not being able to handle withdrawal and seeing no value in quitting. Long-term ARs did not reach 7%. Conclusions: In a sample of Jordanian smokers (>9CPD) with cancer and receiving smoking cessation treatment, ARs were low and further declined with time. Results underscore the need for more aggressive patient management and rigorous follow-up during and after smoking cessation treatment, particularly when this takes place in challenging settings. Observed reasons for failure to abstain should be used to tailor counseling practices.

Risk Factors for Cervical Cancer and CIN3 in Jewish Women in Israel - Two Case Control Studies

  • Bassal, Ravit;Schejter, Eduardo;Bachar, Rachel;Perri, Tamar;Korach, Jacob;Jakobson-Setton, Ariella;Ben-David, Liat Hogen;Cohen, Daniel;Keinan-Boker, Lital
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.4
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    • pp.2067-2073
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    • 2016
  • Purpose: The aim of the study was to identify risk and protective factors/markers for cervical cancer and cervical intraepithelial neoplasia 3 (CIN3) in Israeli Jewish women in order to settle the discrepancy of low incidence rate of cervical cancer and relatively high incidence rate of CIN3. Materials and Methods: We conducted two case control studies, which examined the association between potential risk and protective factors/markers for cervical cancer or CIN3 using self administered detailed questionnaires. Results: For studying cervical cancer, 40 cases and 40 matched controls were interviewed. In the univariable and multivariable analyses older age, depression or anxiety and ever smoking seemed to act as independent risk factors/markers, while older age at first intercourse was protective. For studying CIN3, 99 cases and 79 controls were interviewed. Multivariable analysis has demonstrated that being born in Israel, depression or anxiety and ever smoking were independent risk factors/markers for CIN3. Conclusions: The risk factors/markers studied, that were associated with cervical cancer or CIN3 among Jewish women in Israel, are similar to those reported in other parts of the world, and do not explain the observed discrepancy of high in-situ cervical cancer rates and low invasive cervical cancer incidence in Israel.