• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.4
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• pp.343-349
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• 2007

The reduced scale fire test provides basic data but it is not enough to analysis real fire problem directly because there is no exact analogy theory between a real fire and the reduced scale model. Therefore we have developed the large scale calorimeter in order to the real scale fire test. This advanced large scale calorimeter used for physical properties such as a heat release rate, based upon consumption of $O_2$ method. Using this large scale calorimeter, we cameo out the real scale vehicle fire test in order to evaluation for heat release rate. We obtained the calculated result for HRR $2.3{\sim}3.4\;MW$ and this result is very similar to the PIARC candidate HRR. It is approve that this facility has the reliability and it is capable of applying to the advance fire research in the future.

• The Korean Journal of Quaternary Research
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• v.2 no.1
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• pp.51-85
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• 1988

The understanding of the faunal sequence and palaeoenvironment of East Asia since the Late Tertiary depends mainly on the knowledge of Chinese fauna and its environmental changes. The recent Chinese researches including geology, geomorphology, climats fluctuation and loess distribution of this area have provided that the rapid uplifting of Himalayas and Qinghai/Xizang Plateau since the Lower Pleistocene was a main selective factor for the process of environmental changes in this vast territory. Although different concepts of the Plio-Pleistocene boundary have been provided, its boundary can not exceed over 2 mya. Instead of the traditional zoogeographical dicthomy in China, faunal compositions of Pleistocene are divided into three faunal zones. The knowledge of macrofaunal evolution in China are useful to understand the palaeoecology of East Asia. Palaeoenvironment of Korea during the Pleistocene Period can be reconstructed by using the analogy of the current Chinese studies.

• Journal of Korean Medical classics
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• v.33 no.4
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• pp.1-19
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• 2020

Objectives : This paper aims to understand the meaning and utilitarian values of 'Jongyong(從容)' in medicine by studying its meaning in the 『Huangdineijing』. Methods : Examples of 'Jongyong(從容)' usages in Chinese literature and classical texts were studied first. Next, the similarities and characteristics of its contexts in discourses between Leigong and Huangdi were examined, followed by further examination of the overall meanings of the six chapters, 「Shicongronglunpian(示從容論篇)」, 「Zhuzhijiaolunpian(著至敎論篇)」, 「Shuwuguolunpian(疏五過論篇)」, 「Zhengsishilunpian(徵四失論篇)」, 「Yinyangleilunpian(陰陽類論篇)」, 「Jiejingweilunpian(解精微論篇)」 and the verses that include 'Jongyong(從容).' Results : Generally 'Jongyong(從容)' describes a resilient attitude that responds appropriately and calmly to difficult external situations while maintaining one's character, or refers to one's general behavior. In the 『Huangdineijing』, 'Jongyong(從容)' is only mentioned in discourses between Leigong and Huangdi, which talks about ancient East Asian clinical medicine in general, its transmission and education. Here, the meaning of 'Jongyong(從容)' could be summarized as an expansion of analogical thinking[引比類], medical work that involves the physician's commitment(人事), and detailed measurement of yinyang difference in the body(刑法, 陰陽, 治數). Discussion : In ancient East Asian medicine, the meaning of 'Jongyong(從容)' is closer to measurement of the yinyang difference rather than differentiation of the five element analogy. It is a medical practice that measures the shape, volume, length, area, height, concentration etc. of the human body in numerical figures to allow for the most subtle comparison, which was an important aspect of the physician's work that needed to be demonstrated, educated and transmitted to later generations to enable continuity of the medical profession.

• The Journal of the Acoustical Society of Korea
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• v.39 no.2
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• pp.77-86
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• 2020

In this study, the Eulerian/Lagrangian one-way coupling method is proposed to predict flow noise due to Blade-Tip Vortex Cavitation (BTVC). The proposed method consists of four sequential steps: flow field simulation using Computational Fluid Dynamics (CFD) techniques, reconstruction of wing-tip vortex using vortex model, generation of BTVC using bubble dynamics model and acoustic wave prediction using the acoustic analogy. Because the CFD prediction of tip vortex structure generally suffers from severe under-prediction of its strength along the steamwise direction due to the intrinsic numerical damping of CFD schemes and excessive turbulence intensity, the wing-tip vortex along the freestream direction is regenerated by using the vortex modeling. Then, the bubble dynamics model based on the Rayleigh-Plesset equation was employed to simulate the generation and variation of BTVC. Finally, the flow noise due to BTVC is predicted by modeling each of spherical bubbles as a monople source whose strength is proportional to the rate of time-variation of bubble volume. The validity of the proposed numerical methods is confirmed by comparing the predicted results with the measured data.

• Journal of the Korean Chemical Society
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• v.62 no.1
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• pp.36-42
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• 2018

In this study, we investigated the characteristics of analogies generated by middle school students in the perspectives of the number of analogies, the mapping understanding, and the diversity and originality of analogs. We also compared the results by students' scientific creativity, field independence/dependence, and learning approach. Participants in this study were 250 9th graders in Seoul. The analyses of the results revealed that the students of higher scientific creativity generated more analogies, had a higher level of mapping understanding, and used more diverse and original sources. Field independent students had a higher level of mapping understanding. However, the other characteristics of analogies were not related to field independence/dependence. Meaningful understanding approach was related to all the characteristics of analogies, while rote learning approach was not related to any characteristics of analogies. Educational implications of these findings are discussed.

• The KSFM Journal of Fluid Machinery
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• v.4 no.3 s.12
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• pp.7-13
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• 2001

The present study investigates convective heat/mass transfer and flow characteristics inside a cooling passage of rotating gas-turbine blades. The rotating duct has staggered ribs with $70^{\circ}$ attack angle, which are attached on leading and trailing surfaces. Naphthalene sublimation technique is employed to determine detailed local heat transfer coefficients using the heat and mass transfer analogy. Additional numerical calculations are conducted to analyze the flow patterns in the cooling passage. The present experiments employ two-surface heating conditions in the rotating duct because the exposed surfaces to hot gas stream are pressure and suction side surfaces in the middle passages of an actual gas-turbine blade. Secondary flows are generated by Coriolis and centrifugal forces in the spanwise and streamwise directions. The ribs attached on the walls disturb the mainflow resulting in recirculation and secondary flows near the ribbed wall. The local heat transfer and flow patterns in the passage are changed significantly according to rib configurations and duct rotation speeds. Therefore, the geometry and arrangement of the ribs are important for the advantageous cooling performance. The experimental results show that the ribs enhance the heat transfer more than $70\%$ from that of the smooth duct. The duct rotation generates the heat transfer discrepancy between the leading and trailing walls due to the secondary flows induced by the Coriolis force. The overal heat transfer pattern on the leading and trailing walls for the first and second passes are depended on the rotating speed, but the local heat transfer trend is affected mainly by the rib arrangements.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1993.05a
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• pp.134-136
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• 1993

Using the extended H$\ddot{u}$ckel molecular orbital method in connection with the tight binding model, we have studied electronic structure and related properties of superconducting $YBa_2Cu_3O_{7-x}$ crystals in which O-atoms in regular sites were selectively replaced with F atoms. The calculations are based on the crystal structure of Y-Ba-Cu-O obtained by Beno et al.. We use atomic coordinates that refer to the unrelaxed Y-Ba-Cu-O system. In analogy to the isomerism problem with molecules, we discuss all possible combinations of F-substitutions in O-sites with one, two, and four F atoms. The calculations are carried out within charged clusters model for the analogues of the YBa-free copperoxide. Our results suggest that the electronic structure of the symmetrically F-substituted or F-added compound is closer to that of the oxygen-deficient superconducting compound than that obtained from unsymmetrical substitution. This applies in particular if O is replaced with in an O(1) site. This suggests that superconductivity is very sensitive to the oxygen content of the $CuO_2$ layers.

• Journal of Forest and Environmental Science
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• v.31 no.3
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• pp.214-224
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• 2015

The economy of India and so also of many Asian countries depends on bamboos and their uses are not only in domestic items but also in rural housing and raw materials to several industries and germplasm characterization is an important link between the conservation and utilization of plant genetic resources. Classical taxonomic studies of the bamboos are based on floral morphology and growth habit, which can cause problems in identification due to erratic flowering coupled with different biotic agencies and environmental factors. Identification and genetic relationships among accessions of Thamnocalamus falconeri were investigated using morphology and random amplified polymorphic DNAs (RAPD) technique. Analysis started by using 51 vegetative characters and forty two 10-mer primers that allowed us to distinguish different genotypes hailing from different eco- zones of Garhwal Himalayas (India). The selected primers (12) were used for identification and for establishing a profiling system to estimate genetic diversity. A total of 79.33% polymorphism was estimated by using 12 selected primers. The genetic similar analysis was conducted based on binary digits i.e. presence (1) or absence (0) of bands, which revealed a wide range of variability among the species whereas genetic relatedness was quite high based on vegetative characters. Cluster analysis clearly showed two major clusters for both of the markers viz. morphology and RAPD belonging to 10 accessions of T. falconeri. Two major clusters were further divided into minor clusters. Cluster based on RAPD marker showed grouping of accessions of closed locality whereas analogy was reported for vegetative traits. The RAPD technique has the potential for use in species identification and genetic relationships studies of bamboo for breeding program.

• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.325-333
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• 2001

The present study investigates convective heat/mass transfer and flow characteristics inside the cooling passage of the gas-turbine blades. It is important to increase not only the heat transfer rates but also the uniformity of heat transfer in the cooling passage. The square duct has compound-angled ribs with $60^{\circ},\;70^{\circ}$ and $90^{\circ}$ attack angles, which are installed on the test plate surfaces. a naphthalene sublimation technique is employed to determine the detailed local heat transfer coefficients using the heat and mass transfer analogy. The ribs disturb the main flow resulting in the recirculation and secondary flows near the ribbed wall and the vertices near the side-wall. The local heat transfer and the secondary flow in the duct are changed largely according to the rib orientation. Therefore, geometry and arrangement of the ribs are important fur the advantageous cooling performance. The angled ribs increase the heat transfer discrepancy between the wall and center regions because of the interaction of the secondary flows. The average heat/mass transfer coefficient and pressure drop of the ribs with the $60^{\circ}$ $-90^{\circ}$ compound-angle are higher than those with the $60^{\circ}$ attack angle. Also, the thermal efficiency of the compound-angled rib is higher than that with the $60^{\circ}$ attack angle. The uniformity of heat/mass transfer coefficient on the cross ribs may is higher than that on the parallel ribs array.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.5
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• pp.390-396
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• 2007

In the present study, we have developed a flapping wing using a smart material to mimic the nature's flyers, birds. The wing consists of composite frames, a flexible PVC film and a surface actuator, and the main wing motions are flapping, twisting and camber motions. To change the camber, a Macro-Fiber Composite(MFC) is used as the surface actuator, and it's structural response is analyzed by the use of piezoelectric-thermal analogy. To measure the lift and thrust simultaneously, a test stand consisting of two load cells is manufactured. Some aerodynamic tests are performed for the wing in a subsonic wind tunnel to evaluate the dynamic characteristics. Experimental results show that the main lift is mostly affected by the forward velocity and the pitch angle, but the thrust is mostly affected by the flapping frequency. The effect of the camber generated by the MFC actuator can produce the sufficient lift increment of up to 24.4% in static condition and 20.8% in dynamic condition.