• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.26 no.2
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• pp.85-92
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• 2020

In this study, the relationship between packaging design and logistics efficiency raised in prior research was to be conducted through empirical analysis in terms of SCM efficiency. The main research contents were carried out in the pursuit of efficiency of the relevant store operation, relationship with SCM efficiency aspects, resolution of differences in recognition between manufacturers and distributors, establishment of automated systems for RRP production facilities and processes in the manufacturer's facilities, logistics costs, environment and quality safety, and promotion of RRP through the manufacturer's packaging system. As a result of the verification of SCM efficiency aspects through this study, logistics efficiency will be reduced in the case of the packaging system or delivery system, where only the operational efficiency of the store is the top priority(χ² = 178.500, p < 0.001). This is because of the strong interaction between packaging and supply chain activities, many packaging systems affect the performance criteria of the supply chain, and the content that packaging personnel should ensure that the packaging system meets other essential requirements while meeting the primary goal of protecting the product is also a result consistent with the preceding study. An analysis of whether the RRP promotion through the manufacturer's packaging system would result in improved loading efficiency showed that there was a statistically meaningful difference at a significant level of 0.000, as χ² = 140.133.

• Journal of Korean Society for Quality Management
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• v.25 no.1
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• pp.80-99
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• 1997

This paper considers designing the simple (2-level) constant-and step-stress ALTs minimizing the asymptotic variance of the maximum likelihood estimator of the accelaeration factor, which is defined as the ratio of the 100qth percentile at use stress to that a specified stress, for items having lognormally-distributed lives. It is assumed that (i) the log-linear relationship exists between the stress and the mean log life, (ii) the standard deviation of the log life is constant, and (iii) the cumulative exposure model holds for the effect of changing stress. For the constant-stress ALT the low stress and the sample proportion allocated to low stress are determined and for two modes of stress loading of step-stress ALTs, the low-to-high and high-to-low, the low stress and the stress change time are determined. For selected values of the design parameters the optimum plans are figured, two modes of step-stress ALTs and the constant-stress ALT are compared to each other, and the effects of the incorrect pre-estimates of the design parameters are investigated.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.3 s.108
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• pp.219-225
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• 2006

In Seoul, several railway depots are located at the places where a public can easily access. Since a depot occupy a large amount of land itself, it is natural to use those sites for a public building construction such as an apartment complex or a transportation terminal, as an example. Most of the buildings on a depot, however, are exposed to vibration problems, because foundations are excited from the dynamic loading whenever heavy trains pass on the track. Severe vibration may cause a damage to building structures and a troublesome to a community. In this paper, some vibration practices have been examined in order to resolve the vibration problems. First, a critical speed of a train in a railway depot is evaluated. Then, the structural effect has been investigated. Finally, practical approaches to reduce the vibration level have been proposed. In this first half part of the paper, the focus has been on the critical speed and a structural transmission phenomena.

• Journal of The Korean Dental Society of Anesthesiology
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• v.2 no.1 s.2
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• pp.27-32
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• 2002

Hemophilia A is the most common congenital bleeding disorder, which is sex-linked disease, caused by a deficiency of clotting factor VIII. We experienced a case of alveolorrhaphy using iliac bone graft under general anesthesia for the correction of bilateral cleft alveolus in 10-year-old boy with hemophilia A. Factor VIII activity in this patient was 0.7%, on the severely deficient level, and aPTT was 100 seconds. Just before operation, he received 1,750 units of factor VIII intravenously for loading dose. After we confirmed his factor VIII activity improved to 95% and aPTT to 38.4 seconds, operation was begun. No more transfusion was needed during the operation. In his postoperative care, he received 50 units/kg a 12 hours for 3 days and 30 units/kg a 12 days for 2 days. His factor VIII activity was maintained at 57-139% during his hospitalization. He was discharged without any anesthetic complication. So we report this successful case of anesthetic management for the oral surgery in a child with hemophilia A.

• Journal of Industrial Technology
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• v.19
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• pp.269-278
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• 1999

When a variety of repeated loads are given, most steel structures failed in much lower level of loads than static failure loads. In addition, bridge always includes the internal defects or discontinuities. from these, fatigue cracks initiates and can lead to sudden failure. Thus, in this study, tensile specimens by the cover plate shapes were used as the test specimens. The fatigue test was performed by constant amplitude fatigue loading and beach mark. From the results of this study, each specimen's fatigue section was observed. in addition, stress intensity factor at crack tip was calculated by using the Green's function which applied to discontinuous section where causing stress concentration. Therefore, the fatigue life of structural detail was investigated by adopting the theories of fracture mechanics. each specimen's crack shape is a semi-elliptical surface crack or center crack sheet, stress gradient correction factor, Fg is the most subjective of all stress intensity correction factors and fatigue life should be predicted by previous proposed function and finite element analysis.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.4 no.4
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• pp.201-208
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• 2000

The reduction of NO by hydrocarbons was investigated over Cu/Al$_2$O$_3$catalysts using a stainless steel flow reactor under highly oxidising diesel exhaust conditions(up to 15%). Three different Cu loadings(1,5 and 10wt.%) on an $Al_2$O$_3$support were prepared and characterized using spectroscopic techniques. The catalytic activity tests show that different Cu loadings as well as temperature, oxygen, and hydrocarbon concentration levels significantly influence the NO reduction. Increasing Cu loadings up to 5 and 10wt.% decreases the catalytic activities for NO reduction due to the formation of a bulk crystalline CuO phase, as observed from XRD and SEM images. In particular, the visualization of the copper dispersion on the surface using the SEM-BEI technique provides information on the extent of copper saturation, particle size, and the effects on NO reduction. However, the lower Cu loading(1 wt.%) increases the catalytic activity with a temperature window of 720-810K, thereby favoring the formation of well dispersed isolated Cu species, e.g. Cu(sup)2+ ions, which is related to selective NO reduction. The effects of other reaction parameters, such as oxygen, the hydrocarbon level and type, and byproduct emissions are further discussed.

• Computers and Concrete
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• v.12 no.1
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• pp.1-18
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• 2013

This paper presents an actual microstructure-based numerical method to investigate the mechanical properties of concrete at mesoscopic level. Digital image processing technique is used to capture the concrete surface image and generate the actual 3-phase microstructure of the concrete, which consists of aggregate, matrix and interfacial transition zones. The microstructure so generated is then transformed into a mesh or grid for numerical analysis. A finite difference code FLAC2D is used for the numerical analysis to simulate the mechanical responses and failure patterns of the concrete. Several cases of concrete with different degrees of material heterogeneity and under different compression loading conditions have been analysed. From the numerical results, the effects of the internal material heterogeneities as well as the external confining stresses are studied. It is shown that the material heterogeneities arising from the presence of different phases and the existence of interfacial transition zones have great influence on the overall mechanical behaviour of concrete and that the numerically simulated behaviour of concrete with or without confining stresses applied agrees quite well with the general observations reported in the literature.

• Geomechanics and Engineering
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• v.20 no.1
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• pp.29-41
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• 2020

It is extremely important to obtain rock strength parameters for geological engineering. In this paper, the evolution of sandstone cohesion and internal friction angle with plastic shear strain was obtained by simulating the cyclic loading and unloading tests under different confining pressures using Particle Flow Code software. By which and combined with the micro-crack propagation process, the mesoscopic mechanism of parameter evolution was studied. The results show that with the increase of plastic shear strain, the sandstone cohesion decreases first and then tends to be stable, while the internal friction angle increases first, then decreases, and finally maintains unchanged. The evolution of sandstone shear strength parameters is closely related to the whole process of crack formation, propagation and coalescence. When the internal micro-cracks are less and distributed randomly and dispersedly, and the rock shear strength parameters (cohesion, internal friction angle) are considered to have not been fully mobilized. As the directional development of the internal micro-fractures as well as the gradual formation of macroscopic shear plane, the rock cohesion reduces continuously and the internal friction angle is in the rise stage. As the formation of the macroscopic shear plane, both the rock cohesion and internal friction angle continuously decrease to a certain residual level.

• Korean Medical Education Review
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• v.22 no.2
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• pp.57-66
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• 2020

The purpose of this study was to examine teaching strategies from cognitive learning theory applied to medical education and to present specific applications of the strategies and cases. The results of this study yielded (1) seven teaching strategies and specific sample activities that instructors can use based on learning processes in medical schools; (2) nine instructional events to which cognitive learning strategies were applied; (3) principles of curriculum design from a cognitive perspective; and (4) instruction cases employing cognitive teaching strategies. Cognitive learning theory has two implications: first, if instructors in medical schools apply the results of the study to design a class and curriculum, it would be possible for them to minimize cognitive loading of the learners that may stem from ineffective teaching strategies or curricula; second, cognitive teaching strategies that seek improvement in thinking skills could provide useful teaching strategies for medical education, which aims to develop experts with high-level thinking processes. In this sense, cognitive learning theory is not an out-of-date learning theory, but one that can be effectively applied in current medical education.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.222-227
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• 2008

This study is focused on an integrated numerical modeling enabling one to investigate the dynamic behavior and failure of 2-D textile composite and 3-D orthogonal woven composite structures weakened by micro-cracks and subjected to an impact load. The integrated numerical modeling is based on: I) determination of governing equations via a three-level hierarchy: micro-mechanical unit cell analysis, layer-wise analysis accounting for transverse strains and stresses, and structural analysis based on anisotropic plate layers, II) development of an efficient computational approach enabling one to perform transient response analyses of 2-D plain woven and 3-D orthogonal woven composite structures featuring the matrix cracking and exposed to time-dependent loads, III) determination of the structural characteristics of the textile-layered composites and their degraded features under various geometrical yarn shapes, and finally, IV) assessment of the implications of stiffness degradation on dynamic response to impact loads.