• Structural Engineering and Mechanics
• /
• v.90 no.2
• /
• pp.143-157
• /
• 2024

Cold-formed steel (CFS) I sections are increasingly being used as load-bearing components in building constructions, and such I sections frequently incorporate web holes to facilitate service installation. The economical and structural advantages of these elements have prompted many researchers to investigate the behavior of such structures. Despite numerous studies on the buckling stability of castellated beams, there is a notable absence of experimental investigation into oval castellated beams with stiffeners. This study examines the local buckling of cold-formed steel castellated I-beams stiffened with oval constellations through experimental and numerical analysis. Four specimens are fabricated with and without stiffeners, including parallel, perpendicular, and intersecting types attached to the web portion of the beam, along with cross stiffeners for the oval-shaped openings at the beam ends. Additionally, a numerical model is developed to predict the behavior of castellated beams with oval openings up to failure, considering both material and geometric nonlinearities. Codal analysis is performed using the North American specification for cold-formed steel AISI S-100 and the Australian/New Zealand design code AS/NZS 4600. The anticipated outcomes from numerical analysis, experimental research, and codal analysis are compared and presented. It will be more helpful to the preliminary designers.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.11
• /
• pp.68-73
• /
• 1999

In this paper, the residual stresses for the wide-band laser heat treatment using a polygon mirror have been analyzed. The results of FE analysis are compared with the experimental results. ANSYS Version 5.3, a commercial FE-code, is used for the FE stress analysis. The structural analysis was performed on after thermal analysis. The residual stress distribution across the hardened area was measured by the X-ray diffraction technique. The laser hardening conditions, 2kW laser power and 2mm/s travel speed, were used for the experiment and the FE analysis. Analysis results, which is maximum tensile residual stress is about 143MPa and maximum compressive residual stress is about -380MPa. Under same parameters with the analysis, experimental results indicate that MTRS is about 152MPa and MCRS is about -312MPa. The experimental results is about 6% higher than the FE analysis. As a result, residual stress data from the experiment close well with that of the FE analysis.

• Korean Journal of Oriental Medicine
• /
• v.13 no.2 s.20
• /
• pp.83-90
• /
• 2007

The aim of the study was to analyze recent trends of experimental studies regarding to acupuncture and moxibustion (AM) through reviewing the 492 papers in the PubMed database in order to help researchers from overlapping study on the same theme and to spur them to investigate experimental studies on AM with understanding the current flow of that. For the analysis, we include papers in which abstract was written in English. First, we performed quantitative analysis of the experimental studies using whole of the first filtrated 492 papers. From this analysis, we could obtain the followings: 'Trends of study in the most frequently appeared journals and leading authors in experimental study of AM'. 'The number of papers and name of journals by leading authors in experimental study of AM'. 'Trends of Korean papers in the most frequently appeared journals and Korean leading authors in experimental study of AM", 'Classification of experimental studies related to acupuncture and moxibustion according to intervention methods or individual country' and 'Assortment of experimental studies related to acupuncture and moxibustion in terms of intervention methods on leading countries'. Second, we collected 72 papers considering impact factor of the journal and influential effect of the papers' result for qualitative analysis, and we divided the papers into pain related one or not, because the effect of AM on pain is major subject of AM study. The results showed that experimental studies regarding to AM still has several weakness such as limited usage of acupuncture points and inclined application of electroacupucture even though there are 361 acupuncture points in the human body and various kinds of stimulation methods using traditional needles and moxibustion. Therefore, we suggest that researchers should pay more attention to the study on basic AM research creatively and systematically through strengthening and enhancing the cooperation among colleges, research institutes and hospitals. Moreover, in order to promote the basic research of the AM, it is required that we need cross-disciplinary research as well as international collaboration research.

• Wind and Structures
• /
• v.26 no.4
• /
• pp.231-251
• /
• 2018

The objective of the investigation is the analysis of wind-tunnel experimental errors, associated with the measurement of aeroelastic coefficients of bridge decks (Scanlan flutter derivatives). A two-degree-of-freedom experimental apparatus is used for the measurement of flutter derivatives. A section model of a closed-box bridge deck is considered in this investigation. Identification is based on free-vibration aeroelastic tests and the Iterative Least Squares method. Experimental error investigation is carried out by repeating the measurements and acquisitions thirty times for each wind tunnel speed and configuration of the model. This operational procedure is proposed for analyzing the experimental variability of flutter derivatives. Several statistical quantities are examined; these quantities include the standard deviation and the empirical probability density function of the flutter derivatives at each wind speed. Moreover, the critical flutter speed of the setup is evaluated according to standard flutter theory by accounting for experimental variability. Since the probability distribution of flutter derivatives and critical flutter speed does not seem to obey a standard theoretical model, polynomial chaos expansion is proposed and used to represent the experimental variability.

• The Korean Journal of Applied Statistics
• /
• v.24 no.5
• /
• pp.893-904
• /
• 2011

The lecture of the experimental designs consists of two main part-experimental designs and model analysis. Mostly, the progress of the visualization has been made on a model analysis. As the visualization of experimental designs, we can consider the visualization of Latin squares, supersaturated designs, and balanced incomplete block designs. We can propose the design plots as well as use the scatterplots and the scatterplot matrices for the visualization of experimental designs. Through the visualization of experimental designs, we can use the synergy effect in teaching the lecture of the experimental designs.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.15 no.2
• /
• pp.130-137
• /
• 2012

In this paper, a post-analysis of cooling system for infrared(IR) window was performed based on heating experiment of IR window system. We applied the same experimental conditions to analysis, and then validated the analysis technique by comparing numerical and experimental results. For an analysis software, we used a professional heat/fluid analysis program and the numerical and experimental results were in fairly good agreement. We investigated the effect of thermal transfer between the frame and IR window and also a cooling efficiency between fluid and structure in order to determine the proper parameters for the analysis. In this study, 100 % thermal transfer between the frame and IR window and 30 % cooling efficiency between fluid and structure have been proposed, which can be used in the future conceptual design and analysis of similar IR windows.

• The Korean Journal of Applied Statistics
• /
• v.17 no.3
• /
• pp.499-505
• /
• 2004

The Pareto diagram analysis of the experimental data by the two level orthogonal arrays has been used widely in practice since it is a graphical, quick and easy method to analyze experimental results, which does not use the analysis of variance to screen significant effects. For the analysis of the experimental data by $L_{18}(2 \times 3^7)$ orthogonal array, Park(1996) proposed Pareto ANOVA in which the size of effects is defined by the mean squares of effects and the Pareto principle is used. In this paper, a new approach of the Pareto diagram analysis of the experimental data by $L_{18}(2 \times 3^7)$ orthogonal array is proposed. The main idea is to partition the size of three level effects by that of linear and quadratic orthogonal contrasts of those effects.

• Herbal Formula Science
• /
• v.31 no.4
• /
• pp.389-413
• /
• 2023

Objectives : This study aimed to review the current trends in experimental studies on the use of natural products for treatment of gastroesophageal reflux disease (GERD). Methods : Experimental studies assessing the efficacy of natural products against GERD were searched on PubMed. Articles were selected based on predefined inclusion and exclusion criteria and then analyzed for experimental methods, interventions, and result analysis techniques. Results : A total 37 studies were included in this review. Predominantly, in vivo experiments were conducted to induce GERD through surgery, involving the ligation of the pylorus and the transitional junction between the corpus and the forestomach using 7-week-old male Sprague-Dawley rats. The acute induction model, sacrificing animals after a single administration following GERD induction, was mainly used.The utilization of cell experiments was relatively infrequent, with a focus on assessing antioxidant and anti-inflammatory effects via the treatment of the RAW 264.7 cell line with lipopolysaccharides treatment. Glycyrrhizae Radix et Rhizoma, Pinelliae Tuber, Ginseng Radix and Zingiberis Rhizoma were used as single ingredients, and herbal formula, STW-5 (iberogast), Rikkunshito (六君子湯), Banhasasim-tang (半夏瀉心湯), and Hewei Jiangni granule (和胃降逆湯) were used. Outcome analysis methods encompassed Macroscopic evaluation, esophageal function assessment, blood biomarker analysis, histological examination, protein analysis, gene expression analysis, and gastric juice analysis. Proton pump inhibitors were predominantly employed as positive controls. Conclusions : This study revealed the current trends in non-clinical research evaluating natural products for GERD. Based on the results of this study, we expect that non-clinical research on clinically effective natural products will be revitalized.

• KSBB Journal
• /
• v.15 no.4
• /
• pp.393-397
• /
• 2000

The cometaboic biodegradation conditionso f trichloroethylene(TCE) by Burkholderia cepacia G4 were optimized using response surface analysis. The experimental sets of phenol concentration temperature and pH were designed using central composite experimental design. The optimal conditions of phenol concentration temperature and pH were determined to be 0.91 ppm 21.5$^{\circ}C$ and 7.65 respectively by the Ridge analysis of the contour plot for TCE biodegradation rates. The TCE biodegradation rate could be enhanced up to 2.43 nmol.mg protein$.$min by response surface methodology.

• Journal of Welding and Joining
• /
• v.22 no.2
• /
• pp.28-32
• /
• 2004

Fatigue life at seam weldment of thick plate was estimated using the finite element and FEM-FAT(an exclusive fatigue solver). Finite element meshing at toe and root of weldment was based oil Radaj's theory. Also, the results of FE analysis were compared with experimental results in the point of Miner's Rule. The results of FE and FEM-FAT analysis were in accord with experimental results within 60% confidence. This result reveals that above techniques is useful in assessment of seam weldment and to be an alternative method instead of an object experiment.