• 한국화재소방학회논문지
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• 제10권2호
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• pp.13-19
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• 1996

An estimation methodology, based on statistics and numerical method, has been developed for estimating the upper explosive limits(UEL) of paraffinic and olefinic hydrocarbon compounds. With proposed method, the UEL has been calculated for 24 paraffinic and 10 olefinic hydrocarbon compounds. The estimated the UEL agree with the experimental values within a few percent. A comparisond with four other methods avaiable in the literature are also presented. It is hoped eventually that this method will permit estimation of the UEL with improved accuracy and broader application for other compounds.

• 한국자동차공학회논문집
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• 제13권2호
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• pp.58-64
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• 2005

An infinite element for impact problem has been developed using ABAQUS/Standard UEL. 4-node plane strain element was considered, and the constitutive equation was derived from properties of propagation plane body waves. The element acts as unbounded domain to the plane waves generated by impact. The numerical method was tested for the simulation of plate impact. The results show the effectiveness of the infinite element.

• Asian-Australasian Journal of Animal Sciences
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• 제32권7호
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• pp.1015-1026
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• 2019

Objective: The objective of this study was to evaluate three different degrees of white striping (WS) addressing their automatic assessment and customer acceptance. The WS classification was performed based on a computer vision system (CVS), exploring different machine learning (ML) algorithms and the most important image features. Moreover, it was verified by consumer acceptance and purchase intent. Methods: The samples for image analysis were classified by trained specialists, according to severity degrees regarding visual and firmness aspects. Samples were obtained with a digital camera, and 25 features were extracted from these images. ML algorithms were applied aiming to induce a model capable of classifying the samples into three severity degrees. In addition, two sensory analyses were performed: 75 samples properly grilled were used for the first sensory test, and 9 photos for the second. All tests were performed using a 10-cm hybrid hedonic scale (acceptance test) and a 5-point scale (purchase intention). Results: The information gain metric ranked 13 attributes. However, just one type of image feature was not enough to describe the phenomenon. The classification models support vector machine, fuzzy-W, and random forest showed the best results with similar general accuracy (86.4%). The worst performance was obtained by multilayer perceptron (70.9%) with the high error rate in normal (NORM) sample predictions. The sensory analysis of acceptance verified that WS myopathy negatively affects the texture of the broiler breast fillets when grilled and the appearance attribute of the raw samples, which influenced the purchase intention scores of raw samples. Conclusion: The proposed system has proved to be adequate (fast and accurate) for the classification of WS samples. The sensory analysis of acceptance showed that WS myopathy negatively affects the tenderness of the broiler breast fillets when grilled, while the appearance attribute of the raw samples eventually influenced purchase intentions.

• 한국안전학회지
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• 제25권2호
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• pp.35-40
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• 2010

Explosion limit and flash point are the major combustion properties used to determine the fire and explosion hazards of the flammable substances. In this study, in order to predict upper explosion limits(UEL), the upper flash point of n-alcohols were measured under the VLE(vapor-liquid equilibrium) state by using Setaflash closed cup tester(ASTM D3278). The UELs calculated by Antoine equation using the experimental upper flash point are usually lower than the several reported UELs. From the given results, using the proposed experimental and predicted method, it is possible to research the upper explosion limits of the other flammable substances.

• 한국안전학회지
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• 제33권4호
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• pp.8-14
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• 2018

In the industrial chemical process involving combustible materials, reliable safety data are required for design prevention, protection and mitigation measures. The accurate combustion properties are necessary to safely treatment, transportation and handling of flammable substances. The combustion parameters necessary for process safety are lower flash point, upper flash point, fire point, lower explosion limit(LEL), upper explosion limit(UEL)and autoignition temperature(AIT) etc.. However, the combustion properties suggested in the Material Safety Data Sheet (MSDS) are presented differently according to the literatures. In the chemical industries, tetralin which is widely used as a raw material of intermediate products, coating substances and rubber chemicals was selected. For safe handling of tetralin, the lower and flash point, the fire point, and the AIT were measured. The LEL and UEL of tetralin were calculated using the lower and upper flash point obtained in the experiment. The flash points of tetralin by using the Setaflash and Pensky-Martens closed-cup testers measured $70^{\circ}C$ and $76^{\circ}C$, respectively. The flash points of tetralin using the Tag and Cleveland open cup testers are measured $78^{\circ}C$ and $81^{\circ}C$, respectively. The AIT of the measured tetralin by the ASTM E659 apparatus was measured at $380^{\circ}C$. The LEL and UEL of tetralin measured by Setaflash closed-cup tester at $70^{\circ}C$ and $109^{\circ}C$ were calculated to be 1.02 vol% and 5.03 vol%, respectively. In this study, it was possible to predict the LEL and the UEL by using the lower and upper flash point of tetralin measured by Setasflash closed-cup tester. A new prediction method for the ignition delay time by the ignition temperature has been developed. It is possible to predict the ignition delay time at different ignition temperatures by the proposed model.

• Restorative Dentistry and Endodontics
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• 제42권4호
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• pp.324-331
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• 2017

Objectives: This study evaluated smear layer removal by different chemical solutions used with or without ultrasonic activation after post preparation. Materials and Methods: Forty-five extracted uniradicular human mandibular premolars with single canals were treated endodontically. The cervical and middle thirds of the fillings were then removed, and the specimens were divided into 9 groups: G1, saline solution (NaCl); G2, 2.5% sodium hypochlorite (NaOCl); G3, 2% chlorhexidine (CHX); G4, 11.5% polyacrylic acid (PAA); G5, 17% ethylenediaminetetraacetic acid (EDTA). For the groups 6, 7, 8, and 9, the same solutions used in the groups 2, 3, 4, and 5 were used, respectively, but activated with ultrasonic activation. Afterwards, the roots were analyzed by a score considering the images obtained from a scanning electron microscope. Results: EDTA achieved the best performance compared with the other solutions evaluated regardless of the irrigation method (p < 0.05). Conclusions: Ultrasonic activation did not significantly influence smear layer removal.

• 한국화재소방학회논문지
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• 제25권2호
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• pp.114-119
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• 2011

폭발한계와 인화점은 가연성물질의 화재 및 폭발의 위험성을 결정하는데 중요한 연소특성치이다. 본 연구에서는 산류와 케톤류의 폭발상한계를 예측하기 위해서, 평형상태에서 인화점을 측정하는 Setaflash 밀폐식 장치(ASTM D3278)를 사용하여 이들의 상부인화점을 측정하였다. 측정된 상부인화점을 이용하여 Antoine 식에 의한 계산된 폭발상한계는 기존의 문헌값들보다 약간 낮게 나타났다. 본 연구에서 제시한 실험 및 예측 방법을 이용하여 다른 가연성물질의 폭발상한계 예측이 가능해 졌다.

• Archives of Plastic Surgery
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• 제48권5호
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• pp.534-542
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• 2021

Background During the early stages of lymphedema, active physiologic surgical treatment can be applied. However, lymphedema patients often have limited knowledge and misconceptions regarding lymphedema and surgical treatment. We analyzed the correlations between lymphedema severity and surgical technique according to patients' awareness of surgical treatment for secondary upper extremity lymphedema (UEL). Methods Patients with UEL diagnosed between December 2017 and December 2019 were retrospectively evaluated. At the time of their presentation to our hospital for the treatment of lymphedema, they were administered a questionnaire about lymphedema and lymphedema surgery. Based on the results, patients were classified as being aware or unaware of surgical treatment. Lymphedema severity was classified according to the arm dermal backflow (ADB) stage and the MD Anderson Cancer Center (MDACC) stage based on indocyanine green lymphography conducted at presentation. Surgical techniques were compared between the two groups. Results Patients who were aware of surgical treatment had significantly lower initial ADB and MDACC stages (P<0.05) and more frequently underwent physiologic procedures than excisional procedures (P=0.003). Conclusions If patients are actively educated regarding surgical treatment of lymphedema, physiologic procedures may be performed during the early stages of UEL.

• 한국공간구조학회지
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• 제1권1호
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• pp.43-50
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• 2001

• Journal of Mechanical Science and Technology
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• 제16권10호
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• pp.1276-1286
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• 2002

The numerical techniques are presented to solve the static and dynamic contact problems of deformable bodies having large rotations of the contact surfaces. The contact conditions on the possible contact surfaces are enforced by using the contact error vector, and an iterative scheme similar to augmented Lagrange multiplier method is employed to reduce the contact error vector monotonically. For dynamic contact problems using implicit time integration, a contact error vector is also defined by combining the displacement, velocity, and acceleration on the contact surface. The suggested iterative technique is implemented to ABAQUS by using the UEL subroutine UEL. In this work, after the computing procedures to solve the frictional contact problems are explained, the numerical examples are presented to compare the present solutions with those obtained by ABAQUS.