• Journal of the Korean Society for Aviation and Aeronautics
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• v.15 no.4
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• pp.117-130
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• 2007

Incheon International Airport has handled 3,054,485 transfer passengers (11.9% transfer rate) and 950,441 transfer cargo(44.2% transfer rate)recorded in 2005. Comparing to 30-40% transfer passenger rate which are competition hub airports in northeast Asia, transfer passenger rate of Incheon International Airport is lower. Above all, We think that Minimum Connecting Time(MCT) which is relating factors with transfer rate need to be monitored to make up for the weak points in the current Incheon internationalairport system. Minimum Connecting Time is defined the legally minimum time necessary to change planes at a given airport. and Transfers represent 35% of the total passenger volume at Vienna International Airport in Europe, which underscores our function as a major international hub. Vienna is rated priority in reservation systems because of our excellent minimum connecting time, and that increases the sale of tickets through our airport. In 2004 the total number of transfer passengers rose 18% to 5,089,624. Short routes, a one roof concept and an outstanding logistics system make Vienna an ideal airport for transfers. This transfer-friendly one roof concept will also form the basis for the new VlE-Skylink Terminal. In case of Japan, Star Alliance has also implemented its so called "Move under one roof"concept at the new Centrair airport. All member carriers are located in the same part of the termina1, sharing check-in counters and ticketing facilities. Star Alliance member carriers can now offer customersa reduced average minimum connecting time of one hour, for transfers between international and domestic. The research purpose of the Study on the Enhancement for Minimum Connecting Time of Incheon International Airport is to increase transfer rate of passenger and cargo of Incheon International Airport at Northeast Asia through this paper.

• Tribology and Lubricants
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• v.14 no.3
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• pp.39-45
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• 1998

Reynolds equation, which describes behavior of fluid film in journal bearings, basically satisfies mass conservation. But, boundary conditions usually used with this equation, e.g. half Sommerfeld or Reynolds boundary conditions, cannot fulfill this natural law of conservation. In the case of connecting rod bearing, where applied load is dynamic and its magnitude is relatively large, such unrealistic boundary conditions have serious influence on calculation results, especially on lubricant flow rate or power disspation which are important parameters in thermal analysis. In this paper, mass-conserving boundary condition was applied in the finite element analysis of connecting rod bearings. Lubricant flow rate and power dissipation rate were calculated together with journal center locus, minimum film thickness and maxmium film pressure. These computation results were compared with those of the case of Reynolds boundary condition. Balance between inlet and outlet flow rate was well achieved in the case of mass-conserving boundary condition.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.04a
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• pp.212-217
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• 1998

Reynolds equation, which describes behavior of fluid film in journal bearing, basically satisfies mass conservation. But, boundary conditions usually used with this equation, e.g. half Sommerfeld or Reynolds boundary conditions, cannot fulfill this natural law of conservation. In the case of connecting rod bearing, where applied load is dynamic and its magnitude is relatively large, such unrealistic boundary conditions have serious influence on calculation results, especially on lubricant flow rate or power dissipation which are important parameters in thermal analysis. Another important factor in the analysis of connecting rod bearing is elastic deformation of bearing support structure which is relatively flexible. In this paper, EHL analysis of connecting rod beating is performed using mass-conserving boundary condition. Elastic deformation of bearing support structure and application of mass-conserving boundary condition have significant effects on the performances of connecting rod bearing.

• Journal of Korean language education
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• v.25 no.1
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• pp.235-265
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• 2014

This study is for looking into distinguishing features in child KSL learners' early literacy development. For these, the writings, recording data of dialogue, and observational journals of KSL child learners was collected regularly and the data were analysed. As results, KSL child learners showed lots of writing errors due to difficulty in phonological awareness or letter awareness of Korean language. And they seemed to develop the competence of connecting letters and meanings prior to developing the competence of connecting letters and sounds. Three KSL child learners showed great individual differences in development rate, and it is supposed to be mainly caused from differences of literacy development in their mother tongue, or quantity and quality in exposure for Korean language.

• Korean Journal of Veterinary Research
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• v.14 no.2
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• pp.159-171
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• 1974

Histological and histochemical studies were made on the lining epithelia of the various ducts in epidymis of the Rooster and absorptive function of the canal epithelial cells in the Rooster epididymis were also investigated after administration of India ink. The results obtained were summerized as follows; 1. Epihtelium lining the rate testis was mainaly composed of single later of cuboidal cells, and was partially composed of flattened squamous or low columnar cells. Efferential ductules were characterized by having many villous projections orrfolds which extened into the lumen, and were lined by stereociliated pseudostratified epithelium which consisted of manily ciliated columnar cells, a few scattered clear cells and basal cells. Connecting ductules were lined by ciliated pseudostriatified colummnar epithelium in which ciliated columnar cells, clear cells and basal cells were noted. Epididymal ducts were lined by pseudostratified epidhelium in which columnar and basal cells were noted. 2. PAS-granules, saliva resistant were noted mainly in the epithelial cells of efferential and connecting ductules. 3. Sudan black B stained heavily the granules in the epithelial cells of sufferential and connecting ductules. 4. The granules reactive to acid phosphatase most abundant in the epithelial cells of efferential ductules and were lesser amount in the epithelial cells of connecting ductules where as very few or no granules were seen in the rest of the ducts. 5. Alkaline phosphatase activity was most prominent but discontinuous in the luminal surface of the epithelium of efferential ductules and less marked in the connecting ductless. No enzyme activity was noted in the canal epithelium of epididyml duct. 6. India ink granules were most numerous in the epithlial cells of efferential ductules and were a few in connecting ductules. Very few or no granules of India ink were noted in the other types of the ducts. India ink granules in the epithelium increased gradually as the time after the administration of India ink (one up to twenty-nine hours) has proceeded. From those results it is suggested that epithelial cells of efferential and connecting ductules have active absorptive function, whereas the rest of duct system in the epididymis of the Rooster may be the mere pathway of the seminal fluid without significant modification of its constituents.

• Tribology and Lubricants
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• v.22 no.4
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• pp.203-210
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• 2006

Two kinds of crankshaft oil supply system which were called continuous and discontinuous oil sup-ply system have recently been adopted in engine developing process. In order to clarify the lubrication characteristics for theses systems, in this paper, the comparison studies on supplied oil temperature, pressure, aspect ratio of bearings, and radial clearance were carried out for the main and the connecting rod bearing using computational fluid dynamic analysis.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.9
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• pp.41-47
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• 1999

The scale of dendritic structure of a cast preform plays a key role in determining the mechanical properties of cast/forged products. In this study, casting experiments are carried out to reduce dendrite arm spacing (DAS) to smaller than 20 ${\mu}$m by increasing cooling rate of the mold and then to spheriodize dendritic structures by addition of alloying elements such as Zr and Ti-B. From the casting experiments, appropriate casting conditions for producing the cast preform of a motorcycle connecting rod are obtained. To obtain fine microstructures of the cast preform, mold temperature must set to be low whilst cooling rate being high. When cooling rate is 10 $^{\circ}C$/s, the size of DAS is 17.4 ${\mu}$m. And the degree of spheriodization of a grain in the cast preform is described by aspect ratio, which is defined as the ratio of major and minor radii of an elliptical grain. When 0.5% Zr and 0.24 % Ti+B are added to the molten aluminum alloy, the best aspect-ratio 0.75 is obtained. After forging the cast preform of a motorcycle connecting rod, the microstructure and mechanical properties of the cast preform are compared with those of the cast/forged product. Cast/forged products are superior in microstructure and in mechanical properties such as ultimate strength, elongation, and hardness.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.6
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• pp.90-95
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• 2004

In this study, for the crankshaft bearing design adapting discontinuous oil supply system, analyses were conducted to determine the lubrication characteristics such as oil flow rate and increase of oil temperature at main bearing and connecting rod bearing. Additionally, supplied oil pressure and temperature effects on the bearings were simulated to figure out lubrication characteristics on the bearings. Finally the effects of increasing the bearing width and clearance were introduced on the lubrication characteristics.

• Carbon letters
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• v.7 no.4
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• pp.271-276
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• 2006

Porous carbon materials were prepared with a thermal treatment of coal tar pitch at 550 in the Ar gas. Growth, merger, and distribution of pore were characterized with scanning electron microscopy as variation ascending temperature gradient and chamber pressure. After graphitizing at the 2600 (1 hr.), walls and connecting parts between pores were investigated with X-ray diffraction patterns. Wall thickness and pore size decreases as increasing ascending temperature gradient, and pore size becomes homogeneous. Graphite quality and thermal conductivity become higher due to the enhanced orientation of walls and connecting parts between pores.

• Tribology and Lubricants
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• v.22 no.1
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• pp.47-52
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• 2006

It is very important to control pressure and flow rate distribution on each component of engine lubrication network. Sometimes many kinds of orifice are used to control flow rate in the hydraulic lubrication field. In this study orifices were adopted on the lubrication network to control oil flow rate distribution. And unsteady transient flow network analysis was carried out to find out the effects of orifices on the engine oil circuit system.