• Fire Science and Engineering
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• v.9 no.1
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• pp.10-19
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• 1995

Study on combined natural convection-radiation In partially open square enclosures filled with absorbing-anisotropic scattering media is performed. A heater block located in the enclosure causes the natural circulation of the fluid in the enclosure which results In significant in-flow of the cold fluid through the partially open wall. Four different locations of the heater are considered to observe the effect of the heater locations on the resulting heat transfer. Results obtained from the combined convection-radiation analyses show much stronger circulation of t he fluid inside the enclosure as compared to those obtained from the pure convection analyses. As the ratio of the open area is Increased, the inflow of the cold fluid and the circulation of the fluid inside the enclosure is increased causing lower fluid temperature Inside the enclosure. It is shown that the location of the heater influences the circulation and heat transfer significantly by showing stronger circulations and more uniform temperature distributions for the cases where the heater is located on the bottom wall as compared to those for the cases where the heater is located on the upper part wall of the enclosure. For pure absorbing medium, the expected circulation in the fluid is relatively week as compared to those with absorbing-scattering medium due to the smaller wall heating as the radiant heat is used to heat the fluid instead. The forward anisotropic scattering phase function is shown to increase the fluid circulation further as compared to the isotropic scattering medium.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.2
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• pp.169-175
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• 2004

In this paper, the stability of cantilever composite laminated structures with open channel section is studied. This paper deals with the buckling behavior under the variation of the geometrical shape (length ratio, crank angle in the open channel section), the fiber reinforced angle, and so on in order to offer a effective and reliable design data. Also, sensitive analyses are carried out on the stability by the interaction of design factors. Based on this fact, the proper channel section and lamination scheme of composite material cantilever structures are considered in the engineering aspect.

• Journal of Chest Surgery
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• v.24 no.11
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• pp.1115-1124
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• 1991

Recently the thoracic injuries have been markedly increasing due to the vast increase of traffic accident, industrial disaster, and incidental accident as well as the frequent use of the murderous weapons including gun or rifle. Because the thoracic injuries could involve the heart, lung, and great vessels, and would influence the lives, prompt diagnosis and adequate treatment are essential. Most of thoracic injuries can be managed with the conservative treatment and simple surgical procedure such as closed thoracostomy, but certain cases require open thoracotomy to preserve lives and to return to their normal environment. The authors have analysed the result of 53 cases of open thoracotomy after thoracic injuries mainly according to the patient`s chart review. The mean age was 33.4 years old and male to female ratio was about 5: l. Injury mechanisms that elicited thoracic trauma indicated for open thoracotomy were penetrating[47%] and non-penetrating[53%] injuries. The Most common type of the thoracic lesion was hemothorax with or without pneumothorax and diaphragm rupture was the second. 58\ulcornero of thoracic injuries were accompanied by abdominal injuries and 47% by bone fractures. 34 patients were operated within 24 hours after injury and their average elapsed time was 13.6 hour. The remained patients were operated after 24 hours and their average elapsed time was 7.8 days. 71 cases of operative procedures containing some overlappings were performed: diaphragm repair[28], bleeding control[12], pulmonary and cardiac repair[4 cases] Postoperative complication rate was 32.1% and operative mortality rate was 9.4%[5/53].

• Journal of computational fluids engineering
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• v.17 no.2
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• pp.21-27
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• 2012

Reynolds-averaged Navier-Stokes equations solver based on a pressure-based cell-centered finite volume method was developed using OpenFOAM libraries, which was an open source and providing computational continuum mechanics libraries. For the reasonable development of the turbulent boundary layer on the bow of the ship, specified library was developed. Grid sensitivities, such as skewness and aspect ratio of a cell, were tested for the solution convergence. Pressure, turbulent kinetic energy, turbulent dissipation rate contours on the ship surface computed by the developed CFD code were compared with those computed by the commercial CFD code, Fluent.

• Knowledge Management Research
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• v.16 no.4
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• pp.1-16
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• 2015

This paper aims to explore the small and medium sized enterprises'(SMEs') technological innovation through an open innovative strategy. Researchers have identified open innovation as external search 'breadth' and 'depth'. Although an open innovation strategy is well known as an effective way for SMEs' innovation, this stream of research examines differences between pursuing breadth of external knowledge and depth of external knowledge for SEMs' innovation. The sample comprises a total of 1106 SMEs included in the Korean Innovation Survey, and logistic regression analysis and odds ratio comparison were used to evaluate the relationship between external knowledge search and innovation outcomes. The results show that both 'breadth' and 'depth' positively affect the SMEs' innovation. When SMEs are simultaneously pursuing external searching for breadth and depth, however, a negative result on innovation outcome followed because of the lack of their internal resources and capacities. Despite these contributions, we have certain limitations that can be regarded as means of future research. Even though breadth and depth are adopted to measure the way of how a firm sources the external knowledge, companies may place the different weight on each source of knowledge. And also, it is difficult to understand how the knowledge gained through external search contributes to a firm's incremental and radical innovation, respectively.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.6
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• pp.563-575
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• 2007

This contribution contained the classical work of an open-hole tensile plate to demonstrate the performance of grating shearography and to compare with the results obtained by other full-field measurement techniques, The isotropic plate with an open-hole has often appeared in the previous contributions introducing novel full-field method and system. Grating shearography directly provided six quantitative measurands about the specimen's surface kinematics by using a single measurement set: three in-plane strains, in plane rotation, and two out-of-plane slopes. The quasi-plane wavefront of grating metrology led to high signal-to-noise ratio (SNR) and thus neither fitting nor filtering was applied, and the small shearing distance of $101{\mu}m$ could be used. The small shearing distance provided the outstanding spatial resolution of $80{\mu}m$ and sensitivity appropriate for experimental mechanics. Finally, the grating shearography enabled the visualization of the complex surface deformation around the hole and also detected parasitic flexions of the specimen in the micrometer regime during the tensile test.

• Steel and Composite Structures
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• v.42 no.6
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• pp.843-853
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• 2022

The fatigue behavior of welded open rib-to crossbeam joints (ORCJ) in orthotropic bridge structures is investigated using a traction structural stress method. The fatigue behaviors of welded open rib-to crossbeam joints have been a subject of study for decades for ensuring operational safety and future design improvement. A mesh-insensitive combination of traction structural stresses in ORCJ was obtained considering the effect of in-plane shear stress and validated by fatigue test results. The proposed method is advantageous for predicting fatigue cracks that initiate from the crossbeam cutout and propagate along the crossbeam. The investigations carried out with the proposed approach reveal that the normal structural stress decreases with the propagation of fatigue cracks, while the ratio of shear stress to normal stress increases. The effect of shear structural stress is significant for the analysis of fatigue behavior of ORCJ in multiaxial stress states.

• Journal of Korean Society of Steel Construction
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• v.18 no.5
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• pp.563-574
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• 2006

The objective of this study is to determine the effect of the loading size on displacements of stiffened plates with open ribs using the orthotropic rigidity ratio as the parameter. To analyze the displacement behavior of stiffened plates according to the loading size, a concentrated load and three types of uniform distributed loads were applied on the rib at the center of some plates. The results of the analysis of various stiffened plates show that the central displacement ratio of the distributed load to the concentrated load increased according to the decrease in the loading size, and that the ratio can be expressed as a function of the rigidity ratio for each rib space. The maximum displacement of the stiffened plate subjected to the distributed load did not appear at the center of the plate due to the local behavior, and the increasing ratio of the maximum displacement to the central displacement can be expressed as a function of the rigidity ratio for each rib space. Orthotropic plate analysis can achieve more accurate results using the proposed functions, and the application of the functions to examples of a different aspect ratio and support condition shows good accuracy. Therefore, using the functions proposed in this study, the central and maximum displacements can easily be achieved in the orthotropic plate analysis of stiffened plates subjected to the distributed load.

• Korean journal of food and cookery science
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• v.15 no.6
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• pp.645-651
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• 1999

The lipid and fatty acid composition of various poultry eggs were examined after extracting yolk oils from the eggs of caged hen, open barn-reared hen, mallard, and muscovy duck. Total lipid content in 100 g of each edible portion was the highest in muscovy duck egg followed by open barn-reared hen, mallard, caged hen, and natural hen eggs. The triglyceride contents in the egg were in the order of caged hen, open barn-reared hen, natural hen, mallard, and muscovy duck. The cholesterol contents in total lipid were the highest in caged hen and muscovy duck eggs(4.5%), and the lowest in mallard(3.3%). Caged hen eggs had higher neutral lipid ratio among total lipid, but had lower ratio of glycolipid and phospholipid compared with those of the open barn-reared hens. For fatty acid composition, linoleic acid was the highest in the muscovy and linolenic acid was the highest in open barn-reared hen eggs. The contents of arachidonic acid and Eicosapentaenoic acid(EPA) were the highest in muscovy eggs. On the other hand, the content of Docosahexaenoic acid(DHA) was the highest in muscovy duck eggs.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1143-1148
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• 2007

LRE(Liquid propellant Rocket Engine) is one of the important parts to control the motion of rocket. For operation of rocket in error boundary of the set-up trajectory, it is necessarily to control the thrust of LRE according to the required thrust profile and control the mixture ratio of propellants fed into combustor for the constant mixture ratio. It is not easy to control thrust and mixture ratio of propellants since there are co-interferences among the components of LRE. In this study, the dynamic model of LRE was constructed and the dynamic characteristics were analyzed with control system as PID control and PID+Q-ILC(Iterative Learning Control with Quadratic Criterion) control. From the analysis, it could be observed that PID+Q-ILC control logic is more useful than standard PID control system for control of LRE.