• Korean Membrane Journal
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• v.3 no.1
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• pp.39-50
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• 2001

The counter-diffusion of two gaseous substances permeating a polymeric membrane has been investigated both experimentally and theoretically. The aim of the study was to find mutual effects, if any, that could influence the permeability and diffusivity data. The experimental data were obtained with an isostatic permeameter operating at ambient pressure and 303 K: helium, nitrogen, carbon dioxide methane were used as permeating gas at different partial pressure; helium or nitrogen as equilibrating or carrier gas. No evident mutual effect of the counter-diffusing gas was observed. The theoretical analysis gave some insight into the phenomena and it was concluded that at near-atmospheric pressures, and in the absence of swelling phenomena no mutual interaction exists. On a theoretical basis any mutual interaction between diffusing and counter-diffusing gases could only occur: i) at high pressures , when the free movement of permeating gas molecules within the polymer is hindered by the counter-diffusing gas; ii) when a large part of the free volume fraction is occupied by the counter--diffusing gas; iii) swelling phenomena modify the structure and free volume fraction of the polymer.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.2
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• pp.201-210
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• 2002

Experiments were done for performance and flow characteristics of a counter-rotating axial flow fan. Performance curves of a counter-rotating axial flow fan were obtained and compared by varying the blade pitch angles. The fan characteristic curves were obtained following the Korean Standard Testing Methods for Turbo Fans and Blowers (KS B 6311). The fan flow characteristics were measured using a five-hole probe and a slanted hot-wire. The velocity profiles between the hub and tip of the fans were measured and analyzed at the peak efficiency point. The peak efficiency of the counter-rotating axial flow fan was improved about 15% respectively, compared with the single rotating axial fan. The single rotating axial flow fan showed relatively law efficiency due to the swirl velocities behind rotor exit which produced pressure losses. The counter-rotating axial flow fan showed that the swirl velocity generated by the front rotor was eliminated by the rear rotor and the associated dynamic pressure is recovered in the from of the static pressure rise.

• Korean Security Journal
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• no.19
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• pp.187-205
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• 2009

In this study, Horgan(2005)'s argument highlights the centrality to any successful counter-terrorism strategy of understanding the social context in which terrorist ideologies take root. Counter-terrorism refers to the practices, tactics, techniques, and strategies that governments, militaries, police departments and corporations adopt in response to terrorist threats and/or acts, both real and imputed. Pickering et al.(2008) historically explained four counter-terrorism strategies as traditional counter-terrorism model, community intelligence model, belonging model, social cohesion model. It is thus proposed that counter-terrorism strategies are based in established networks within the community and proactively seeks to continually renew these relationships between the community and police. This approach must embrace an explicit recognition of multiculturalism and its political imperative and drive in a policing organization explicitly committed to social cohesion and human rights in both discourse and practice. We, therefore, suggests community tree counter-terrorism approaches, or community intelligence model, belonging model and social cohesion model to apply to counter-terrorism agencies in Korea. These models are on the basis of Pickering et al.'s counter-terrorism models, which by using community policing to boot socially cohesion police are better able to position themselves as mediators to negotiate settlements between the competing demands of different social groups.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.2
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• pp.149-153
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• 1993

Daily energy expenditures (DEE) of 82 co-eds in a University were estimated simultaneously by use of calorie counter and 15-min check list diary for 3 days, including a weekend day. The results are summarized as follows. The mean values of DEE from 15-min check list diary and calorie counter were 1967kcal and 1649kcal, respectively. DEE obtained with 15-min check list diary seems to be consistent with the results made by others concerning DEE of college female in Korea, but DEE by calorie counter was lower than that. However, DEE by calorie counter show high correlations with anthropometric indices of subjects and DEE by 15-min check list diary. Therefore, DEE by 15-min check list diary was taken as standard and regression equation for predicting DEE of subjects were developed: DEE by 15-min check list diary =3.31186 + 1.18837 $\times$ DEE by calorie counter. This technique for measuring DEE permits us to have more accurate estimate of DEE and acceptable to the subjects. When the subjects classified as underweight, normal, overweight according to relative body weight(RBW), DEE and DEE per kg of body weight were significantly different from each other between three groups based on RBW. The frequency of 15-minute periods with a categorical value of 1 was significantly higher in overweight than underweight and normal groups and the frequency of a categorical value 3 was significantly lower in overweight than underweight group. From the results shown above, physical activity level of overweight group was lower than that of normal and underweight groups.

• Korean Security Journal
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• no.57
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• pp.137-156
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• 2018

The purpose of this study is to analyze the current status of counter terrorism system and to identify the causes of problems and to suggest alternatives by selecting legal and operational sectors based on theories of open systems and integrated systems. According to the results of the research, first, the degree of agreement on the open system and the integrated system is low with regard to the characteristics of the counter-terrorism system. Second, in relation to the importance and necessity of major factors of construction and operation of counter-terrorism system, counter-terrorism workers recognize that it is the most important and necessary. In the case of strengthening international cooperative system, the difference of recognition between importance and necessity was the biggest. The importance and necessity of reviewing the Anti-Terrorism Act for the protection of the public and public safety were relatively low, and the cooperation with the private sector showed the lowest importance and necessity. In the case of academic achievement, the average level of high school graduates is higher than that of professional high school graduates. Therefore, this research concludes that counter terrorism operation system with open and integrated system has to be applied to national counter terrorism operation structure in South Korea in increasing the quality and efficiency of nation counter terrorism response capability.

• Journal of Pharmaceutical Investigation
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• v.22 no.4
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• pp.289-300
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• 1992

The counter-transport phenomena in the hepatic transport of 1-anilino-8-naphthalene sulfonate (ANS) were kinetically investigated by analyzing the plasma disappearance-time profiles and the transport into the isolated hepatocytes. In vivo "counter transport phenomena" were simulated based on the perfusion model which incorporated the carrier-mediated transport and the saturable intracellular binding. The condition that the mobility of carrier-ligand complex is greater than that of free carrier is not essential for the occurrence of counter-transport phenomenon. To examine the inhibitory effects on the initial uptake of a ligand by the liver, it is necessary to judge whether the true counter-transport mechanism (trans-stimulation) is working or not. The initial plasma disappearance curves of ANS were then kinetically analyzed based on a two-compartment model, in which the ligand is eliminated only from the peripheral compartment (liver compartment). No effects on the initial plasma disappearance rates of ANS were observed after preloading of bromophenol blue (BPB) or rose bengal (RB) in the liver. Inhibitory effect of BPB or RB on the initial uptake (or efflux) rates of ANS by the isolated hepatocytes were not observed, suggesting that the true counter transport mechanism is not working. In conclusion, checking the preloading effects of transstimulation on the initial uptake of a ligand by the liver could be a useful criterion for carrier cycling and common use of the same carrier between two ligands. However, one cannot exclude those possibilities even if the preloading effects cannot be observed.

• Journal of Computing Science and Engineering
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• v.7 no.4
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• pp.285-299
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• 2013

To enable hard real-time systems to take advantage of multicore processors, it is crucial to obtain the worst-case execution time (WCET) for programs running on multicore processors. However, this is challenging and complicated due to the inter-thread interferences from the shared resources in a multicore processor. Recent research used the combined cache conflict graph (CCCG) to model and compute the worst-case inter-thread interferences on a shared L2 cache in a multicore processor, which is called the CCCG-based approach in this paper. Although it can compute the WCET safely and accurately, its computational complexity is exponential and prohibitive for a large number of cores. In this paper, we propose three counter-based approaches to significantly reduce the complexity of the multicore WCET analysis, while achieving absolute safety with tightness close to the CCCG-based approach. The basic counter-based approach simply counts the worst-case number of cache line blocks mapped to a cache set of a shared L2 cache from all the concurrent threads, and compares it with the associativity of the cache set to compute the worst-case cache behavior. The enhanced counter-based approach uses techniques to enhance the accuracy of calculating the counters. The hybrid counter-based approach combines the enhanced counter-based approach and the CCCG-based approach to further improve the tightness of analysis without significantly increasing the complexity. Our experiments on a 4-core processor indicate that the enhanced counter-based approach overestimates the WCET by 14% on average compared to the CCCG-based approach, while its averaged running time is less than 1/380 that of the CCCG-based approach. The hybrid approach reduces the overestimation to only 2.65%, while its running time is less than 1/150 that of the CCCG-based approach on average.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.10
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• pp.761-769
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• 2013

Effects of helicopter wakes on helicopter aerodynamics are serious, but the wake configuration is very complicated and hard to predict. The purpose of this study is the detailed observation of wake using numerical methods. Vortex lattice method and freewake method are used to track the vortices in the wake. In this paper, the wake configuration is observed during hovering flight. In the case of hovering flight at the moderate thrust level, besides tip vortex, counter-rotating vortex can be observed at the inboard part of blade. When the vortices move downward, tip vortex and counter-rotating vortex get close and influence to each other. Therefore, vortices are highly distorted due to their own instability.

• Korean Institute of Interior Design Journal
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• v.19 no.3
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• pp.30-37
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• 2010

Dutch artist, Theo van Doesburg had shown short but strong experimental aesthetics in his works through De Stijl movement. He played a leading role for editing De Stijl magazine and performed various formative works such as painting, sculpture, and architecture. In 1923 he opened the first De Stijl exhibition cooperated with Cornelis van Eesteren. In this architecture exhibition he showed rich formal spirits of counter-construction in his major design works, that is Maison Particuliere and Maison D'artiste among three houses projects. Formal characteristics of counter-construction can be summed up under two categories, time and space. Analytical results are as follows; First, the characteristics of counter-construction related to time category include two types of two mode. One is linear aspect of time based on the viewer's movement. The other aspect is simultaneity caused by synoptical effect. These could be proved by the analysis of arrangement of color planes. Secondly, the spatial aspects of counter-construction are produced through two different ways of formal strategies. Van Doesburg arranged cubes in very irregular pattern. This treatment induces ambiguous void and creates feeling of subject's space. And, through deleting, shifting, and extending he could make dynamic spatial effect by interpenetration between in and out. This fluid space thus introduces movements of one's gaze and circulation. He denied traditional classical values which had ruled the western aesthetical discipline for centuries and believed that mankind can reach the realm of universal equilibrium by contrast and tension created by counter-construction. In this vein Theo van Doesburg was an avant-garde artist of Hegelian thoughts who adopted the dialectical method without following the formal characteristics from ancestors.

• Analytical Science and Technology
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• v.8 no.2
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• pp.205-213
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• 1995

Counter-diffusion of coronene desorbed from alumina with addition of tetra-phenylporphine was studied by spectrophotometry. The counter-diffusion processes of adsorbing and desorbing materials in liquid phase were simulated by counter-diffusion model based on Fritz's binary component isotherm under an assumption of equimass diffusion. The counter-diffusivities of desorbed coronene with addition of tetra-phenylporphine were as ${\sim}10^{-15}m^2/sec$ and that of adsorbed tetra-phenylporphine as ${\sim}10^{-11}m^2/sec$. The counter-diffusivity of coronene determined from desorption process was smaller by ${\sim}10^5$ times than the diffusivity determined from adsorption process of a single species. The reduction of the determined counter-diffusivity of coronene in desorption process was explained by the cross of diffusion fluxes and build-up of high gradient of coronene in pore.