• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.439-443
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• 2004

In this research, we describe the sorting conditions modeling by friction force. As in any mechanism which is required to provide good dynamic performance and high accuracy, performance evaluation of optimal control. To understand friction it is necessary to investigate the topography of the sliding surfaces in contact. Any surfaces, even apparently smooth surfaces, are microscopically rough. When two surfaces come into contact, the true contact takes place only at point where asperities come together. The sorting conditions of sorting mechanism with friction force is sorting force must be equal with force can sorting one highest veneer among loaded veneer. This is just a thing being sorted veneer have friction with under veneer and this friction disturb sorting at the same time. Hence, the sorting conditions evaluation is important to sorting one veneer must get under control friction with veneer.

• 치위생과학회지
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• 제17권1호
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• pp.56-64
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• 2017

Systemic health conditions increase with advancing age, and may be linked to poor self-reported oral health. The purpose of this study was to evaluate the association between systemic health conditions and poor self-reported oral health among Korean elderly. The study used a nationally representative sample of Koreans (2012 Korea National Health and Nutrition Examination Survey) aged 65~98 years (n=1,595). Systemic health conditions in this population were assessed by the presence of one or more of the following conditions: obesity, hypertension, diabetes, and hypercholesterolemia. The relative risk of poor self-reported oral health according to the occurrence of systemic health conditions was estimated by multivariate logistic regression after controlling for several potential confounders (i.e., socio-demographic factors, oral health behaviors, health behaviors, and psychological factors). After adjustment for these confounders, the relative risk of having poor self-reported oral health was greater among the elderly with one or more systemic health conditions than in those without a systemic health condition. The odds ratio of having poor self-reported oral health according to the occurrence of systemic health conditions was 1.51 (95% confidence interval, 1.08~2.12). Among the Korean elderly, perception of poor oral health was associated with the presence of one or more systemic health conditions. Future studies are needed to examine the detailed causal relation between systemic health conditions and poor oral health longitudinally.

• 한국생활과학회지
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• 제19권4호
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• pp.733-744
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• 2010

This study investigated the working conditions and job satisfaction of school cafeteria, according to their employment type in Chonbuk, South Korea. Self-administered questionnaires were collected from 401 elementary, middle, and high school cafeteria employees. The data showed significant differences between regular and irregular employees. These factors were: previous work experience (p<.001), type of school (p<.001), the style of foodservice at a school (p<.001), the type of foodservice system (p<.05), and the number of meals served each day (p<.001). The working conditions for regular and irregular employees were significantly different with regard to several factors: these were union membership (p<.01), how they were paid (p<.05), their total working hours (p<.01), and difficulty of using their holidays (p<.01). Approximately 80.5% of the subjects were dissatisfied with the working conditions after the introduction of countermeasures for irregular employees. Results indicated that the average employee job satisfaction level was 2.53, but that there were not significant difference in the level of job satisfaction when comparing regular and irregular employees. The item employees were most satisfied with was having responsibility over meals for young students (3.37). They were least satisfied with their salary (2.00). An interesting issue for future study would be to determine the factors that could improve job satisfaction whilst satisfying the employees' needs which in turn would improve the quality of foodservice.

• 대한수학회보
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• 제54권3호
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• pp.917-933
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• 2017

In this paper, seven equivalent conditions of complete moment convergence and complete integral convergence for negatively orthant dependent (NOD, in short) sequences are shown under two cases: identical distribution and stochastic domination. The results obtained in the paper improve and generalize the corresponding ones of Liang et al. [10]). In addition, an extension of the Baum-Katz complete convergence theorem: six equivalent conditions of complete convergence is established.

• Journal of applied mathematics & informatics
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• 제37권3_4호
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• pp.183-200
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• 2019

We have constructed a robust numerical method on Shishkin mesh for a class of convection diffusion type turning point problems with Robin type boundary conditions. Supremum norm is used to derive error estimates which is of order O($N^{-1}$ ln N). Theoretical results are verified by providing numerical examples.

• Journal of Mechanical Science and Technology
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• 제17권6호
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• pp.787-795
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• 2003

Mechanical properties of the materials used for transportations and industrial machinery under high strain rate loading conditions such as seismic loading are required to provide appropriate safety assessment to these mechanical structures. The Split Hopkinson Pressure Bar (SHPB) technique with a special experimental apparatus can be used to obtain the material behavior under high strain rate loading conditions. In this paper, dynamic deformation behaviors of the aluminum alloys such as A12024-T4, A1606 IT-6 and A17075-T6 under both high strain rate compressive and tensile loading conditions are determined using the SHPB technique.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.567-570
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• 2003

A color restoration algorithm for dynamic images under multiple luminance conditions is proposed by using correction vectors, defined for sub regions that the original target is divided into and calculated from color information given in well-illuminated regions. These vectors restore chromatic information of the restored image obtained by the color restoration algorithm in a low luminance condition. Under the condition that the size of dynamic color images in multiple luminance conditions is $320\times240$, experimental results show that the restored image by the proposed algorithm decreases the color-difference about 30％ than that of the restoration algorithm with color change vectors in a low luminance condition. The proposed algorithm aims to construct the surveillance system with a low cost CCD camera in the real world.

• Design & Manufacturing
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• 제6권2호
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• pp.1-5
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• 2012

Weld line in injection molded part is one of the defects in injection molding process. Weld line deteriorates not only appearance quality but mechanical property. In this study, ABS and PP were used as experimental materials. And weld line length, depth and strength have been examined according to the injection molding conditions. As the results of experimental studies, weld line length increased as flow rate increases for all materials. And the flow rate is most influenced to the creation of weld line length. Also weld line strength increased, as flow rate and melt temperature increase for all materials. The whole experiment results was similar to CAE analysis results.

• 한국금형공학회:학술대회논문집
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• 한국금형공학회 2008년도 하계 학술대회
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• pp.115-119
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• 2008

Weld line in injection molded part is one of the defects in injection molding process. Weld line deteriorates not only appearance quality but mechanical property. In this study, ABS and PP were used as experimental materials. And weld line length, depth and strength have been examined according to the injection molding conditions. As the results of experimental studies, weld line length increased as flow rate increases for all materials. And the flow rate is most influenced to the creation of weld line length. Also weld line strength increased, as flow rate and melt temperature increase for all materials. The whole experiment results was similar to CAE analysis results.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.462-463
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• 2006

Monodispersed and nano-sized Ni powders were synthesized from aqueous nickel sulfate hexahydrate $(NiSO_4{\cdot}6H_2O)$ inside nonionic polymer network by using wet chemical reduction process. The sucrose was used as a nonionic polymer network source. The effect of reaction conditions such as the amount of sucrose and a various reaction temperature, nickel sulfate hexahydrate molarity. The influence of a nonionic polymer network on the particle size of the prepared Ni powders was characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and particle size analysis (PSA). The results showed that the obtained Ni powders were strong by dependent of the reaction conditions. In particular, the Ni powders prepared inside a nonionic polymer network had smooth spherical shape and narrow particle size distribution.