• Transactions of Materials Processing
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• v.14 no.1 s.73
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• pp.43-48
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• 2005

The production of metal strip with uniform thickness and flatness are two important problems associated thin strip rolling. The thickness and flatness of strip are affected by the flattening of contact surface between strip and roll, the elastic recovery and the bending of roll. Especially, the flatness of the strip is greatly affected by bending deflection of roll. The roll must be designed considered the elastic deformation of roll. This study describes the measurement of thickness and flatness of strip and shows the crown roll for producing flat strip. But it is difficult to produce the crown roller. The cross rolling that is a simple method which can produce the flat strip is introduced and it is found the optimal cross angle for improvement of flatness of plate. These problems are solved by the MARC code on the basis of elastic-plastic material and the updated Lagrangian formulation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.8
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• pp.847-854
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• 2007

The battery electrode of a mobile phone is made of layered polymer coated on aluminum foils and the hot rolling process is applied to increase the density per volume of an electrode for a high capacity battery. The flatness of batteries surfaces should be less than $2{\mu}m$. To satisfy the required flatness, the deformation of roll surface due to bending and heating of the roll should be minimized. Complicated hot oil paths of $100^{\circ}C$ inside the roll are required for heating the polymer layers. FEA was used to calculate thermal deformations and temperatures distributions of the roller. Based on FEA, a modified surface curvature called a crown roll was suggested and this gave the area of 30% improved flatness compared with a flat roll. The flat roll satisfied the flatness of $2{\mu}m$ in the length of 340 mm and the crown roll resulted in the longer length of 460 mm. Experiments to measure the temperature distribution and thermal strain were performed and compared with FEA. There were only 6% difference between two results.

• The Research Journal of the Costume Culture
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• v.8 no.3
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• pp.486-492
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• 2000

This study is concerned with the jang il (　日). The purpose of this study was to trace the origin of jang il and to identify forms and the meaning of it. Significant findings and results of this research can be summerized as follows : It was found that jang il was a kind of brimmed hat with a round crown. People of Han Dynasty period wore jang il. It was favored by the people of Wei Chin (魏晉) Dynasty period of China and was a very popular hat in these periods. It was used by farmers and merchants. It was found that jang il was worn by a tribe of Kang(羌) in prehistorical period. It is considered that jang il of the Chinese, was derived from the people of Kang(羌). In the Tang and Five Dynasty periods women also wore jang il. Women from the upper class appeared used jang il. It appeared that Koguryoreans also used jang il : it was a kind of black wide brimmed hat with a round crown. which can be found in the tomb paintings of Yong Kang(龍崗). A horse rider wears jang il.

• Journal of the Korean Home Economics Association
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• v.44 no.1 s.215
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• pp.151-157
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• 2006

Ten types of male headgear-Kwonwoonkwan, crown-like headgear, hats with a square flap, hats with feathers, crowns with plumes, Ballip, hats with flat crowns, Somo, turban, and fur hats-were described in Jip-Sah, which was published in the 14th century. Mongolian people used summer headgear, winter hats, and crown ornaments, which had been used until the Ch'ing dynasty of China. From the late 12th century to 1304, the headgear styles remained the same, suggesting that the Mongolian people kept their tradition. Kwonwoonkwan, crown-like headgear, and Somo, presented in Jip-Sah, were also described in U. Yadamsuren's album, a pictorial depiction of the 20th century Mongolian headgear.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.10 no.2
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• pp.49-52
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• 2006

Theses days, the thickness of Brown tube becomes thinner since the display products are rapidly replaced by PDP, LCD etc. Accordingly, the shadow mask part also become flat. We propose the method of designing the surface with crown since the flat surface is fragile to vibration and shock.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.277-285
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• 2019

This study was conducted to understand the growth characteristics of Picea jezoensis that was one of representative subalpine species in Korea, in the light of the effects of wind and micro-topography in its habitats on Mt. Deogyu, Korea. The prevailing wind directions were southwest and west at the study sites. We randomly selected P. jezoensis (height ≥ 1.5 m) on windward, intermediate, and leeward slopes and measured diameter at breast height (DBH), height, crown length by 8 directions in upper, middle and lower sectors of the crown. We examined the micro-topography of P. jezoensis stood on and classified it into 3 types: type 1 was mounded and fully exposed to surrounding environments without neighboring trees; type 2 was somewhat wind-protected by surrounding rocks, but no neighboring vegetation; type 3 was on gentle slope or flat where P. jezoensis grew with neighboring trees or shrubs. The ratios of height to DBH, and estimated crown growth to actual crown growth (hereafter crown growth ratio) were compared among the three types of micro-topography on windward, intermediate and leeward sites. The height growth per DBH and crown growth ratio in the upper and middle crowns were the smallest on the windward site, and the highest on the leeward site (p < 0.01). The crown growth ratio on type 1 on the windward site was only 46% of that on type 3 on the leeward site. Although on the same windward slope, trees on type 1 had more deformed crown shapes than that on Type 3, showing asymmetric crown cross-sectional areas. Wind and micro-topography played critical roles on the crown growth of P. jezoensis.

• KSTLE International Journal
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• v.5 no.2
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• pp.52-56
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• 2004

The hard disk drive performance depends strongly on air bearing characterisitcs of the head slider. The objective of the slider design is to provide accurate positioning of the magnetic read/write element at the very small height above the disk. Application of the numerical methods is required due to complexity of the air bearing surface of the slider. The Boundary-Fitted Coordinate System Divergence Formulation method can be used for calculation of pressure distribution in the case of steep film thickness gradients. In the present work, the interpolating functions used in the expression for the Couette flow are modified in order to improve the solution characteristics in the extremely high compressibility number region. The advantages of the modified method are demonstrated on example of the flat skewed slider. Finally, the modi.ed method is applied to analysis of the static characteristics of the femto-slider. The analysis results indicate the effect of the silder's air bearing surface crown on the flying height and the pitching angle in steady state position.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1068-1071
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• 1996

Good shape on flat rolled product is necessary to meet today's customer quality requirement. To meet the increasing demand in quality of strip shape from downstream customers, POSCO has replaced the Automatic Shape Control(ASC) system with the existing one that had used noncontact type measuring system at No.2 Cold Rolling Mill, Pohang works in October, 1995. The strip shape is influenced by the profile, roll crown, bending control, skew control system, as well as work roll cooling system. We have used ASC to adjust those factors in Cold Rolling Mill that could get a satisfactory result, almost less than .+-.5 1-unit deviation from the target shape. However, the downstream customer(i.e. Continuos Annealing Line) wants a good shape not only at the moment of exit of roll bite, but after rolling without tension. In this investigation, the difference will be discussed and how deal with this problem.

• The Korean Journal of Community Living Science
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• v.21 no.1
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• pp.5-12
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• 2010

The objective of this research was to examine the relationship between food preferences and personality of university students. The questionnaires were distributed to 198 university students in 2009. The data showed high correlation between personality and food preferences. According to the result of food preferences exams the most favorite food of university students was coffee, refreshing drinks, eggs, ice creams, bananas, porks, apples, chickens, weeds, grapes and food they dislike were sea cucumbers, livers, mung bean sprout, crown daisy, flat fishes, bean curd, green lavers, lotus roots, turban shells, egg plant etc. The correlation coefficient between food preferences and personality showed that male students had more dominance and sociability, and female students had more sociability and validity. On the other hand, a good diet group had higher responsibility and a poor diet group had higher sociability. Consequently, good food habits is essentially needed for the formation of desirable personality of students.

• Journal of Microbiology and Biotechnology
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• v.16 no.12
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• pp.1968-1976
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• 2006

Recombinant E. coli ACV 1003 (recA:: lacZ) was used to measure low concentrations of DNA-damaging chemicals, which produce $\beta$-galactosidase via an SOS regulon system. Very low $\beta$-galactosidase activities of less than 0.01 unit/ml, $\beta$-galactosidase produced through an SOS response corresponding to the 10 ng/ml (ppb) of DNA damaging chemicals in the environment, can be rapidly determined by using an alternative interferometric biosensor with optically flat thin films of porous silicon rather than by the conventional time-consuming Miller's enzyme assay as well as the ELISA method. fu order to enhance the sensitivity in the interferometry, it needs to obtain more uniform distribution and higher biolinking efficiency, whereas interferometric sensing is rapid, cheap, and advantageous in high throughput by using a multiple-well-type chip. In this study, pore size adjusted to 60 nm for the target enzyme $\beta$-galactosidase to be bound on both walls of a Si pore and a calyx crown derivative was apllied as a more efficient biolinker. Furthermore, anti-$\beta$-galactosidase was previously functionalized with the biolinker for the target $\beta$-galactosidase to be specifically bound. When anti-$\beta$-galactosidase was bound to the calyx-crown derivative-linked surface, the effective optical thickness was found to be three times as high as that obtained without using anti-$\beta$-galactosidase. The resolution obtained was very similar to that afforded by the time-consuming ELISA method; however, the reproducibility was still unsatisfactory, below 1 unit $\beta$-galactosidase/ml, owing to the microscopic non-uniform distribution of the pores in the etched silicon surface.