• Journal of Korea Society of Industrial Information Systems
• /
• v.11 no.4
• /
• pp.66-71
• /
• 2006

Carbon nanofibers have synthesized a low temperature using DC Ar plasma and Fe-Phthalocyanine, and a characteristic difference of the synthesized CNF according to the location of the substrate was investigated. The carbon nanofibers had about 100nm diameter and up to $10{\mu}m$ length. These were grown in random orientation. There are two shapes in the CNFs, screw and straight line shapes. Furthermore, we found the selective growth of nanofibers on the scratched substrates. The density of CNFs synthesized on the position (a) were higher than that synthesized on the position (b) [See the Fig. 2]. Also, the length of CNFs was different. In the shape, CNFs with screw and straight line shape were synthesized in the position (a), but. only CNFs with straight line shape were synthesized in the position (b). The difference have an important effect on the field emission characteristics.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.6 no.1
• /
• pp.73-87
• /
• 2004

In the designing stage, the HANBOK CHIMA is created using a flat pattern with linear shapes. However, when worn, the skirt creates a fluid and organic silhouette. According to the wearing method(wrapping), HANBOK CHIMA can create various shapes and movements. In comparison to the general skirt, It is more effective in revealing the wearer's sense of beauty. The method of wrapping the skirt from the rear is a suitable way of wearing the garment in accord with the Korean ON-DOL(온돌) culture and it creates mystique eroticism. We can devide the silhouettes according to six different period of time. The silhouette of HANBOK CHIMA is affected by the following elements: length, width, pleats, textures and the usage of underwear. [1. Koguryo (5C∼6C) - The first Tent silhouette. 2. The South Dynasty Silla (7C∼8C) - The second Tent silhouette. 3. Kyoryo dynasty (l4C) - Cylinder silhouette. 4. The first Chosun dynasty (late 14C∼17C) - Bell silhouette and Cylinder silhouette. 5. The second Chosun dynasty (mid 18C∼mid 19C) - Bell silhouette and Barrel silhouette. 6. The third Chosun dynasty (late 19C∼the beginning of 20C) - Tent, Cylinder and Bell silhouette.]

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.19 no.9
• /
• pp.2173-2180
• /
• 1995

This paper presents free vibration analysis method using the characteristics of the rotationally periodic structures and includes the analysis results of a tire as an example. The normal modes of the rotationally periodic structures are the kind of standing waves, so all sectors have the same deflection shapes, and only different phases. This property makes it possible to derive the analysis method called sector method. The sector method can give the accurate natural frequencies and the corresponding mode shapes of the rotationally periodic structure with information of only one sector. When the free vibration analysis is performed to find the dynamic characteristics of the rotationally periodic structure by using the sector method, the computer memory spaces and the CPU times can be saved. We obtained much economic benefits by using the sector method in the analysis of dynamic characteristics of a tire made of non-linear materials.

• 한국신재생에너지학회:학술대회논문집
• /
• 2006.11a
• /
• pp.184-187
• /
• 2006

The heat transfer characteristics of solar tower receivers are experimentally investigated with receiver shapes. Generally the heat transfer characteristics become different according to the shapes and materials of the volumetric air receiver. In order to study these effects, The experimental apparatus adopting laminated mesh and honeycombs as the volumetric air receiver is proposed. The receiver consists of laminated mesh (diameter; 100mm, thickness; 1mm), honeycombs (diameter; 100mm, thickness; 30 mm) inserted out the heat transfer characteristics of the laminated mesh the air temperatures are obtained by installing 3 thermocouples on each layer, dividing ceramic tube into 4 layers. Also, a radiative shield is installed to measure the only air temperature. The data for laminated mesh and honeycomb thickness of 30, 60, 90mm are obtained. The results show that the temperature of layer 3 is higher than those of layer 2 and layer 1.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.24 no.3
• /
• pp.353-360
• /
• 2000

The purpose of study examined the changes of the man's underclothes from the ancient ages to the early modern ages. The method of study researched literatures and possessions of the museum. In ancient ages, a suit of clothes had the functions of both underclothes and outer garments. In middle ages, underclothes were not exposed and the importance was not recognized while they were worn to show the sense of sin and humility or to punish criminals. In early modern ages, the importance of underclothes recognized as they were exposed. In Renaissance period, the fashion of the day influenced much on the underclothes. In Baroque ages, the functions of underclothes were different according to sexes and men wore underclothes to show their social status. As the outer garments were shortned, shirt wwere also conspicuously exposed. In Rococo ages, drawers were tightened due to the influence of outer garments, men exposed their shirts to show the social status and underclohtes were usually worn to express sexual attraction. Men's underclothes had the functions of class distinction from the ancient ages to the modern ages, except the middle ages and underclothes had the additional functions such as supporting body-shape and sex attraction. The fashion of the day influenced on the changes of the shapes of the shapes of men's underclothes and the changes of outer garments were reflected on underclothes.

• Korean Journal of Head & Neck Oncology
• /
• v.26 no.2
• /
• pp.204-211
• /
• 2010

Background and Objectives : Boundary detection and drawing are essential in 3D reconstruction of neck mass. Manual tracing methods are popular for drawing head and neck tumor. To improve manual tracing, circular boundaries overlapping was tried. Materials and Methods : Twenty patients with neck tumors were recruited for study. Representative frames were examined for shapes of outline. They were all single closed curves. Circular boundaries were added to fill the outlines of the tumors. Inserted circles were merged to form single closed curves(Circular boundary overlapping, CBO). After surface rendering, 3 dimensional images with volumes and area data were made. Same procedures were performed with manual tracing from same cases. 3D images were compared with surgical photographs of tumors for shape similarity by 2 doctors. All data were evaluated with Mann-Whitney test(p<0.05). Results : Shapes of boundaries from CBO were similar with boundaries from manual tracing. Tumor outlines could be filled with multiple circular boundaries., While both boundary tracing gave same results in small tumors, the bigger tumors showed different data. Two raters gave the similar high scores for both manual and CBO methods. Conclusion : Circular boundary overlapping is time saver in 3 dimensional reconstruction of CT images.

• 한국연소학회:학술대회논문집
• /
• 2002.06a
• /
• pp.140-146
• /
• 2002

The tulip-inversion of flames in half-open tubes was investigated experimentally. Experiments was carried out in tubes with various shapes. The image of a flame propagation were pictured by HICCD(High speed intensified CCD) and the dynamic pressure of tubes was measured by a piezo pressure sensor. By analyzing the images of the flame propagation, we found the time and the distance for the occurrence of tulip-inversion. Regardless of the shapes of tubes, time of tulip-inversion are similar and inversely proportional to the burning velocity. But distances have different tendency. In a straight tube, the distance of tulip-inversion increases when the burning velocity increases. But in a converging tube, the distance of tulip-inversion decreases when a burning velocity increases. And the distance of tulip-inversion in a converging tube is much smaller than the distance of tulip-inversion in a straight tube. These results are caused by the deceleration of a flame when the diameter of a hole in open-side of a tube is small. The deceleration causes little effect on the time of tulip-inversion.

• Structural Engineering and Mechanics
• /
• v.38 no.1
• /
• pp.65-79
• /
• 2011

Concrete hydraulic structures such as: Dams, Intake Towers, Piers and dock are usually recognized as" Vital and Special Structures" that must have sufficient safety margin at critical conditions like when earthquake occurred as same as normal servicing time. Hence, to evaluate hydrodynamic pressures generated due to seismic forces and Fluid-Structure Interaction (FSI); introduction to fluid-structure domains and interaction between them are inevitable. For this purpose, first step is exact modeling of water-structure and their interaction conditions. In this paper, the basic equation involved the water-structure-foundation interaction and the effective factors are explained briefly for concrete hydraulic structure types. The finite element modeling of two concrete gravity dams with 5 m, 150 m height, reservoir water and foundation bed rock is idealized and then the effects of fluid domain and bed rock have been investigated on modal characteristic of dams. The analytical results obtained from numerical studies and modal analysis show that the accurate modeling of dam-reservoir-foundation and their interaction considerably affects the modal periods, mode shapes and modal hydrodynamic pressure distribution. The results show that the foundation bed rock modeling increases modal periods about 80%, where reservoir modeling changes modal shapes and increases the period of all modes up to 30%. Reservoir-dam-foundation interaction increases modal period from 30% to 100% for different cases.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.26 no.9
• /
• pp.447-452
• /
• 2014

We evaluated heat transfer characteristics of microscale wrinkles using a CFD (computational fluid dynamics) analysis. In order to verify the heat transfer effect of wrinkles having various shapes, we introduce wrinkling processes to generate few different shapes of wrinkles such as macroscale ($200{\sim}400{\mu}m$ width), microscale ($10{\sim}30{\mu}m$ width), and hierarchical (microscale on macroscale wrinkle) wrinkles, using repetitive-dividing-volume (RDV) method for single-shape of wrinkles and connected method of UV-weakly polymerization with thermal curing for hierarchical structure of winkles. The analysis results of simplified CFD model showed that heat flux on heated plate was changed by the shape of wrinkles on the plate. The increase in heat flux of about 2.6 times was achieved in the case where hierarchical wrinkle structure was used.

• Korean Journal of Materials Research
• /
• v.27 no.11
• /
• pp.609-616
• /
• 2017

We investigated a Leidenfrost effect in the growth of ZnO nanostructures on silicon substrates by ultrasonic-assisted spray pyrolysis deposition(SPD). Structural and optical properties of the ZnO nanostructures grown by varying the growth parameters, such as substrate temperature, source concentration, and suction rate of the mist in the chambers, were investigated using field-emission scanning electron microscopy, X-ray diffraction, and photoluminescence spectrum analysis. Structural investigations of the ZnO nanostructures showed abnormal evolution of the morphologies with variation of the substrate temperatures. The shape of the ZnO nanostructures transformed from nanoplate, nanorod, nanopencil, and nanoprism shapes with increasing of the substrate temperature from 250 to $450^{\circ}C$; these shapes were significantly different from those seen for the conventional growth mechanisms in SPD. The observed growth behavior showed that a Leidenfrost effect dominantly affected the growth mechanism of the ZnO nanostructures.