• Journal of Ocean Engineering and Technology
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• 제15권2호
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• pp.120-123
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• 2001

Despite the increasing necessity of accurate estimation of ring-stiffened cylinders'ultimate strength, the complex structural behavior of cylinders has made their design mainly depend on empirical formulas mostly based on limited test data rather than theoretical background. This paper has developed the imperfection method which enables the ultimate strength analysis of buckling-sensitive structures by combining two separate functions covered by common commercial finite element softwares, which are linear elastic buckling analysis and nonlinear stress analysis. Developed method was applied to two of the world most renowned softwares, MSC/NASTRAN and ABAQUS, for the analysis of ring-stiffened cylinders and unexpectedly big difference in their analysis results was found. This tells that many widely used commercial softwares have their different strong points and weak points and the choice of commercial software should be cautiously made after thorough inspection. This paper ends with some useful information about which of the two aforementioned softwares is more respectively for the linear elastic buckling analysis and the ultimate strength analysis of ring-stiffened cylinders.

• Journal of Information Processing Systems
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• 제15권3호
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• pp.500-519
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• 2019

The blooming of social media has simulated interest in sentiment analysis. Sentiment analysis aims to determine from a specific piece of content the overall attitude of its author in relation to a specific item, product, brand, or service. In sentiment analysis, the focus is on the subjective sentences. Hence, in order to discover and extract the subjective information from a given text, researchers have applied various methods in computational linguistics, natural language processing, and text analysis. The aim of this paper is to provide an in-depth up-to-date study of the sentiment analysis algorithms in order to familiarize with other works done in the subject. The paper focuses on the main tasks and applications of sentiment analysis. State-of-the-art algorithms, methodologies and techniques have been categorized and summarized to facilitate future research in this field.

• Transactions of the Korean Society of Mechanical Engineers A
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• 제26권12호
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• pp.2605-2614
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• 2002

This paper describes an analysis method based on the experimental parameter for the 0.9kW starter motor of vehicle with permanent magnet and pole core, and analyzed the influence by the effect of pole core of starting motor by using the 2D-FEM analysis technique to reflect the structural characteristic of 3D. A starter motor consists mainly of armature, yoke and permanent magnet with the pole core. Additionally, there is different the axial length of each part. Therefore, the effective of analysis method is needed to improve the characteristic of it. This paper approached the 2D-FEM analysis estimated by the 3D-EMCN(Three Dimensional Equivalent Magnetic Circuit Network) instead of the 3D-FEM analysis to minimize parameters. As a result, this paper is proposed the validity of 2D-FEM analysis and obtained reasonable results for improving a performance.

• Transactions of Materials Processing
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• 제13권8호
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• pp.723-730
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• 2004

This paper describes the analysis of extrusion process and integrity for a condenser tube which is a component of the heat exchanger in automobile and all conditioning apparatus. Recently, according to the development of analysis method using the computer, the numerical simulation have been applied to the 3-dimensional hot extrusion process with complex section area of the non-steady statement and then results of the analysis have been applied to optimal die design and process design. In this paper, firstly, the die design was performed for a condenser tube with a multi-hole section and the rigid-plasticity FE analysis performed of extrusion process. Secondly, we estimated metal flow of billet, extrusion load, welding pressure in chamber etc. and evaluated the pressure and elastic strain of the die land and mandrel tooth profile through a stress analysis of the die. Finally, the extrusion test was performed to estimate the validity of FE analysis. This paper confirmed that the designed extrusion die of the research is satisfactorily designed fur integrity of condenser tube.

• Geomechanics and Engineering
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• 제6권6호
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• pp.531-544
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• 2014

Studies of earthquakes over the last 50 years and the examination of dynamic soil behavior reveal that soil behavior is highly nonlinear and hysteretic even at small strains. Nonlinear behavior of soils during a seismic event has a predominant role in current site response analysis approaches. Common approaches to ground response analysis include linear, equivalent linear and nonlinear methods. These methods of ground response analysis may also be categorized into time domain and frequency domain concepts. Simplicity in developing analytical relations and accuracy in considering soils' dynamic properties dependency to loading frequency are benefits of frequency domain analysis. On the other hand, nonlinear methods are complicated and time consuming mainly because of their step by step integrations in time intervals. In part Ι of this paper, governing equations for seismic response analysis of surcharged and layered soils were developed using fundamental of wave propagation theory based on transfer function and boundary conditions. In this part, nonlinear seismic ground response is analyzed using extended HFTD method. The extended HFTD method benefits Newton-Raphson procedure which applies regular iterations and follows soils' fundamental stress-strain curve until convergence is achieved. The nonlinear HFTD approach developed here are applied to some examples presented in this part of the paper. Case studies are carried in which effects of some influencing parameters on the response are investigated. Results show that the current approach is sufficiently accurate, efficient, and fast converging. Discussions on the results obtained are presented throughout this part of the paper.

• International Journal of Internet, Broadcasting and Communication
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• 제14권2호
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• pp.212-218
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• 2022

In this paper, the necessity of AI video interview arises when conducting an interview for acquisition of excellent talent in a non-face-to-face situation due to similar situations such as Covid-19. As a matter to be supplemented in general AI interviews, it is difficult to evaluate the reliability and qualitative factors. In addition, the AI interview is conducted not in a two-way Q&A, rather in a one-sided Q&A process. This paper intends to fuse the advantages of existing AI interviews and video interviews. When conducting an interview using AI image analysis technology, it supplements subjective information that evaluates interview management and provides quantitative analysis data and HR expert data. In this paper, image-based multi-modal AI image analysis technology, bioanalysis-based HR analysis technology, and web RTC-based P2P image communication technology are applied. The goal of applying this technology is to propose a method in which biological analysis results (gaze, posture, voice, gesture, landmark) and HR information (opinions or features based on user propensity) can be processed on a single screen to select the right person for the hire.

• Journal of Korean Clinical Health Science
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• 제2권2호
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• pp.126-132
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• 2014

Purpose. Because traditional statistics approach had limitations in learning future forecasting and major factors causing occupational injuries in each industry, this paper develops a model forecasting and evaluating occupational injury rate by using a system dynamics model through the analysis of the industry injury statistics and the project for industry injury prevention. Method. The model of this paper consists of 12 total models such as a model of employees, of industrial disaster victims, of injury rate, etc.; In the analysis of firm size, it is classified and developed according to 12 groups on the basis of the number of employees, and in the analysis of industrial classification, it is done according to 10 total business fields such as manufacturing business, construction one, etc. Results. This paper suggests the methodology which forecasts industry injury rate by business field and size on the basis of developed model, and evaluates an industry injury prevention project from various angles. Conclusions. This paper deduced problem through the analysis of an industry injury by business fields and a comparative analysis of foreign cases, and analyzed to affect industry injury prevention by industry. And it also analyzed actual condition of industry injury, and did a difference in the level of safety consciousness according to the general characteristics of workers and occupational safety and health education related characteristics. In result, this paper suggests that analyzing occupational injury related factors, a safety budgetary allocation, and industry injury related factors can reduce illness costs such as employees' injury and medical care, and also assist cost for a disability.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• 제45권1호
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• pp.27-34
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• 2013

Quantitative analysis of 5-hydroxymethylfufural (5-HMF) conversion from fructose by dehydration and rearrangement was investigated by $^1H$-NMR spectroscopic method. Fructose was converted to 5-HMF in dimethylsulfoxide (DMSO)-$d^6$ or acidic deuterium hydroxide at controlled reaction temperature and time. With addition of internal standards (biphenyl for DMSO-$d^6$ solvent, and 2,5-dihydroxybenzoic acid for deuterium oxide solvent), conversion from fructose to 5-HMF was analyzed by $^1H$-NMR spectroscopy. Quantitative analysis was run by comparison with peak area integration between of 5-HMF and internal standard. In DMSO solvent, 5-HMF was stable end product but part of 5-HMF was converted to formic and levulinic acid at acidic aqueous medium.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.1204-1209
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• 1990

This paper offers the theory and method for regression analysis of the regression model with operational parameter variables based on the fundamentals of mathematical statistics. Regression coefficients are usually constants related to the problem of regression analysis. This paper considers that regression coefficients are not constants but the functions of some operational parameter variables. This is a kind of method of two-step fitting regression model. The second part of this paper considers the experimental step numbers as recursive variables, the recursive identification with unknown operational parameter variables, which includes two recursive variables, is deduced. Then the optimization and the recursive identification are combined to obtain the sequential experiment optimum design with operational parameter variables. This paper also offers a fast recursive algorithm for a large number of sequential experiments.

• Journal of Food Hygiene and Safety
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• 제14권1호
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• pp.67-75
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• 1999

The new approach using the Peak Pattern Method was conducted for the analysis of polychlorinated biphenyls (PCBs) from the papers or paper products to provide certain hygienic data for the recycled papers as well as white papers. The height of the each peak, obtained from the PCBs standards, was transformed to the spectrum to compare with that of the samples. In addition to the results of the single PCBs standards, the pattern of mixed PCBs standards with the adequate concentration and ratios were obtained prior to the analysis of the paper samples. The test showed excellent repetition within 5% variation, and the recoveries of PCBs ranged from 92% to 97%. The PCBs, considered as a hazard material, were analyzed using the Peak Pattern Method from six different types of paper samples including the roll tissue. It could not find the same pattern of the PCBs peaks from all of the paper samples.