• International Journal of High-Rise Buildings
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• v.10 no.1
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• pp.73-83
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• 2021

The door open time, resulting from occupants evacuating from apartments, is an important parameter when assessing the performance of smoke ventilation systems in high-rise apartment buildings. However, the values recommended in UK design guidance appear to have limited substantiation. Monte Carlo simulations have been carried out considering variabilities in door swing time, flow rate and number of occupants. It has been found that the door open time can be represented by a lognormal distribution with a mean of 6.6, 8.7 and 11.1 s and a standard deviation of 1.7, 3.2 and 4.7 s for one, two and three-bedroom apartments, respectively. For deterministic analyses, it is proposed that the 95th percentile values may be adopted in line with recommended practice for other fire safety design parameters such as fuel load density and soot yield, giving door open times of 10 s to 19 s, depending on the number of bedrooms.

• Steel and Composite Structures
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• v.48 no.6
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• pp.709-725
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• 2023

This paper uses a new type of deformation theory to establish the free vibration and static buckling equations of nanoplates resting on two-parameter elastic foundations, in which the flexoelectric effect is taken into account. The proposed approach used in this work is not only simpler than other higher-order shear deformation theories but also does not need any shear correction coefficients to describe exactly the mechanical responses of structures. The reliability of the theory is verified by comparing the numerical results of this work with those of analytical solutions. The results show that the flexoelectric effect significantly changes the natural frequency and the critical buckling load of the nanoplate compared with the case of neglecting this effect, especially when the plate thickness changes and with some different boundary conditions. These are new results that have not been mentioned in any publications but are meaningful in engineering practice.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.28 no.2
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• pp.70-83
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• 2017

The objective of this review is the revision of the Korean practice parameters for the pharmacological treatment of attention-deficit hyperactivity disorder (ADHD) based on the change in the diagnostic system from DSM-IV-TR to DSM-5 and psychopharmacological developments. For the evidence-based approach, the authors conducted a review of the literature, including controlled clinical trials, studies of the side effects of drugs, toxicology and meta-analyses from the United States and Europe, as well as recent research conducted in Korea. The review committee composed of Korean experts on ADHD reviewed the revised parameters. This revised version reveals how to use central nervous system psychostimulants, non-stimulants such as atomoxetine and alpha2 agonists, and other medication for ADHD, and how to manage the adverse effects of such medication. At the end of this revised version, the authors propose recommendations for the pharmacotherapy of ADHD.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.4 no.1
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• pp.87-101
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• 1997

This Research is an attempt to find out what effects the resistance exercise program has on the rheumatoid arthritis patient's functional disability and biochemical parameters. The research took place from June to November 1996, and the target included an experimental group of 25 cases of rheumatoid arthritis and a control group of 26 cases of rheumatoid arthritis taken from the Anam Medical Center at Korea University. The resistance exercise program was executed on these patients five times a week during a period of eight weeks. Before and after the experiments, measurements of functional disability score, ESR, CRP, self-efficacy, and family support were taken and closely analysed. The results of this analysis are as follows : 1. After the experiment, the experimental group had less functional disabilities compared to the control group(t=9.11, P=0.0017). 2. After the experiment, the ESR of both the experimental and the control groups decrease, but there was not notable difference between the two groups(t=0.07, P=0.9546). 3. After the experiment, the CRP of both the experimental and the control groups decreased, with no significant different between them(t=0.53, P=0.6022). 4. After the experiment, the self-efficacy of the experimental group increased significantly compared to the control group(t=3.15, P=0.0042), but the self-efficacy had no effect on the actual practice of the program. 5. After the experiment, the family support of the experimental group was higher than of the control group(t=6.33, P=0.0013), but again the family support had no effect on the actual practice of the program. Judging from the results of these experiments, the resistance exercise program not only diminishes rheumatoid arthritis patients' functional disabilities, but also has a great influence on increasing their self-efficacy and family support. Concluding, in diminishing the functional disabilities of rheumatoid arthritis, the resistance exercise program would be appropriate nursing intervention.

• Journal of Families and Better Life
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• v.23 no.2 s.74
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• pp.77-91
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• 2005

The purpose of this study is to investigate general tendencies in credit card use, and determine the causes of the use of cash advance service and deferred payment among college students. Socio-demographic variables(gender, year in college, allowance, family income, parents' education and occupation, having taken a personal financial management course), knowledge and attitudes toward credit card, and financial management practices were incorporated as antecedent variables. Logistic regression analysis and multiple regression analysis were conducted to test the hypotheses. The results were as follows ; First, $32\%$ of the college students with no regular income experienced deferred payment, and $60.4\%$ of them had used a cash advance service. Second, the frequency and amount of cash advance service use were affected by family income, financial practices, and allowance. The financial practice as a parameter was affected by their completion of a personal finance course and their allowance. Third, deferred payment of credit was affected by their knowledge on credit cards and their financial practices. The financial practices as a parameter were affected by the family income and their completion of a personal finance course, and the knowledge on credit cards was affected by gender. Lastly, implications and suggestions for credit card use behavior research and consumer credit education are discussed in this article.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.4
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• pp.887-896
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• 1994

It is common practice in the case of optimum reservoir operation model that the reservoir inflow series are generated by stochastic model with keeping other variable such as water demands from the reservoir constant. However, when the input and output of the water distribution system have close relationship the output variables can be stochastically generated in relation with the input variables. In the present study the reservoir inflow series, the input of the system, is generated by periodic autoregressive model with constant parameter, and the agricultural water demand series, the output, is generated using periodic multivariate autoregressive model with constant parameter. The time period of the data series generated is taken as 10-day which is the common period used for agricultural water uses. The results of data generation by two different models showed that the periodic stochastic models well represent the characteristics of the historical time series, and that in the case of generating model for agricultural demand series it has closer relation with reservoir inflow than with the series itself.

• Annals of Clinical Neurophysiology
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• v.4 no.2
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• pp.108-113
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• 2002

Background and Objective : Carpal tunnel syndrome (CTS) is the most common mononeuropathy encountered in clinical practice. No single procedure or group of procedures has demonstrated adequate sensitivity. F-wave study in CTS is very rarely reported. To determine the diagnostic usefulness of new parameters of F-wave and comparative study of F-wave parameters of median and ulnar nerves in patients with CTS. Methods : F-wave responses of median and ulnar nerves were analyzed from 27 patients with clinically diagnosed CTS and 22 age and gender-matched normal control. Conventional F-wave parameters were studied. Also, the usefulness of new parameters such as mean and maximal ulnar-median F-wave latency differences, ulnar-median F-wave persistence and chronodispersion differences, median/ulnar F-wave amplitude ratio, and F-wave conduction velocity (FCV) using mean and maximal latency were assessed. Results : Compared with controls, median F-wave minimal, maximal and mean latencies, mean F-wave amplitude/M-wave amplitude, minimal, mean and maximal ulnar-median F-wave latency differences, and FCVs using minimal, maximal and mean latency were significant (P<0.05~0.001). Median F-wave minimal, maximal and mean latencies, mean ulnar-median F-wave latency difference, and FCVs using minimal, maximal and mean latency showed high sensitivity and specificity. Mean ulnar-median F-wave latency difference and FCVs using maximal and mean latency were new parameters. Conclusion : New F-wave parameter including mean ulnar- median F-wave latency difference and FCVs using maximal and mean latency may be a useful to assess the CTS. Also, median F-wave minimal, maximal and mean latencies, and FCV using minimal latency may be included in routine diagnostic tests in CTS.

• Journal of the Korea Convergence Society
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• v.6 no.4
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• pp.121-126
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• 2015

Korea Youth Panel (2008) has 2 panels of the 5th year of Knowledge data to perform statistical analysis and regression analysis, the risk factors in the risk conditions of the family of functional deficits, protective factors, the relationship between the mediating effect of psychological adaptation and protective factors verification mechanisms and the psychological adaptation level it is an objective to analyze the protective factors that protect the high youth. To investigate the differences by frequency analysis and personal characteristics of the analyte's was performed t test using PASW (Predictive Analytics Software) 18.0. And to verify the effect of the parameters is performed rank regression analysis for verification of the effects of protection factors for adaptation. Rather than focusing on youth risk factors in social welfare practice field, focusing on processes and protective factors to reduce the risk factors, it is possible to convert the viewpoint overlooking the youth exposed to risk factors. Also, for young people experiencing difficulties that features loss of the family, it is determined that the prepared foundation which can be provided in the direction of social welfare practical intervention.

• Steel and Composite Structures
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• v.51 no.5
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• pp.509-527
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• 2024

Bonding carbon fiber-reinforced polymer (CFRP) laminates have been extensively employed in the restoration of steel constructions. In addition to the mechanical properties of the CFRP, the bond strength (P_U) between the CFRP and steel is often important in the eventual strengthened performance. Nonetheless, the bond behavior of the CFRP-steel (CS) interface is exceedingly complicated, with multiple failure causes, giving the P_U challenging to forecast, and the CFRP-enhanced steel structure is unsteady. In just this case, appropriate methods were established by hybridized Random Forests (RF) and support vector regression (SVR) approaches on assembled CS single-shear experiment data to foresee the P_U of CS, in which a recently established optimization algorithm named Aquila optimizer (AO) was used to tune the RF and SVR hyperparameters. In summary, the practical novelty of the article lies in its development of a reliable and efficient method for predicting bond strength at the CS interface, which has significant implications for structural rehabilitation, design optimization, risk mitigation, cost savings, and decision support in engineering practice. Moreover, the Fourier Amplitude Sensitivity Test was performed to depict each parameter's impact on the target. The order of parameter importance was t_c> L_c > E_A > t_A > E_c > b_c > f_c > f_A from largest to smallest by 0.9345 > 0.8562 > 0.79354 > 0.7289 > 0.6531 > 0.5718 > 0.4307 > 0.3657. In three training, testing, and all data phases, the superiority of AO - RF with respect to AO - SVR and MARS was obvious. In the training stage, the values of R² and VAF were slightly similar with a tiny superiority of AO - RF compared to AO - SVR with R² equal to 0.9977 and VAF equal to 99.772, but large differences with results of MARS.

• Geomechanics and Engineering
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• v.36 no.5
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• pp.465-474
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• 2024

Uniaxial compressive strength (UCS) is a critical geomechanical parameter that plays a significant role in the evaluation of rocks. The practice of indirectly estimating said characteristics is widespread due to the challenges associated with obtaining high-quality core samples. The primary aim of this study is to investigate the feasibility of utilizing the gene expression programming (GEP) technique for the purpose of forecasting the UCS for various rock categories, including Schist, Granite, Claystone, Travertine, Sandstone, Slate, Limestone, Marl, and Dolomite, which were sourced from a wide range of quarry sites. The present study utilized a total of 170 datasets, comprising Schmidt hammer (SH), porosity (n), point load index (Is(50)), and P-wave velocity (Vp), as the effective parameters in the model to determine their impact on the UCS. The UCS parameter was computed through the utilization of the GEP model, resulting in the generation of an equation. Subsequently, the efficacy of the GEP model and the resultant equation were assessed using various statistical evaluation metrics to determine their predictive capabilities. The outcomes indicate the prospective capacity of the GEP model and the resultant equation in forecasting the unconfined compressive strength (UCS). The significance of this study lies in its ability to enable geotechnical engineers to make estimations of the UCS of rocks, without the requirement of conducting expensive and time-consuming experimental tests. In particular, a user-friendly program was developed based on the GEP model to enable rapid and very accurate calculation of rock's UCS, doing away with the necessity for costly and time-consuming laboratory experiments.