• Korean Journal of Veterinary Research
• /
• v.39 no.3
• /
• pp.425-434
• /
• 1999

The morphological studies on the cecal development in the 60-, 90-, and 120-day-old fetuses and the newborns of Korean native goats were investigated by scanning and transmission electron microscopy. The results were summarized as follows ; Scanning electron microscopic studies : 1. In the 60-day-old fetuses, fold-like shapes protrusion on the cecal mucosa surface appeared. In the 90-day-old fetuses, the cecal villi appeared to be columnar shapes. In the 120-day-old fetuses, the cecal villi showed various tongue-like or columnar shapes. In the newborns, only the rudimental trace of the villi and the intestinal glands were observed. Transmission electron microscopic studies : 2. In the 60-day-old fetuses, the cecal epithelia were simple columnar in some areas and stratified columnar in others, and the epithelial cells contained nuclei, nucleoli, ER, mitochondria, Golgi complexes, zonula occludens, desmosomes, digitiform intercellular junctions, and large masses of the glycogen granules. 3. In the 90-day-old fetuses, the cecal epithelia were simple columnar in some area and stratified columnar in other. The microvilli of the cecal epithelia became much larger and longer than those in the 60-day-old fetuses, and intercellular junctions were developed, and increased numbers of ER, mitochondria, Golgi complexes were observed and the goblet cells contained a lot of the secretory granules. 4. In the 120-day-old fetuses, the cecal epithelia were only simple columnar in all areas. Microvilli and cytoplasmic organelles were well developed and the irregular annular nuclei were observed. 5. In the newborns, the cecal epithelia were covered with extensive microvilli, and the goblet cells with secretory granules were protruded into the lumen. And some goblet cells secreted the secretory granules into the lumen.

• Education of Primary School Mathematics
• /
• v.26 no.4
• /
• pp.237-255
• /
• 2023

At a time when the textbooks publishing system is changing from government-administered to certified, it is necessary to analyze textbooks published in both systems. This study analyzed one government textbook and three certified textbooks on quadrilaterals based on the instructional components that must be taught in the area of 2-D shapes. As a result of the analysis, it was found that concept exploration was implemented appropriately, but classification activities were not presented in some lessons. In Defining Concepts, the definition of the concept was presented appropriately, but there were differences depending on the textbooks. In addition, it was found that there was little activity in talking about the components of shapes or shapes. In applying concepts, more diverse activities were presented in certified textbooks than in government textbooks. Knowing relationships are rarely presented in textbooks due to its influence on the curriculum. Based on the results of this analysis of quadrilaterals, this study provides textbook writers with implications on what to further consider is dealing with quadrilaterals.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.8 no.3
• /
• pp.34-43
• /
• 2005

We will catch the spatio-temporal changes that analyse the unknown topography of Go-Gunsan Islands using Landsat TM satellite images into an unsupervised ISODATA classification and a supervised nearest likelihood classification. Each sedimental topography has the different characteristics according to building the Saemangeum embarkment. We will deal with the distribution of sedimental shapes using ERDAS Imagine 8. 6. The result that classifies specifically topographic properties of our research area be considered to get use of establishing the reclaiming program and predicating the reclaimed sedimental topography. The research area can be classified into tidal flats and sea level using band 4 among 7 bands of Landsat TM. Also band 5 can be used to classify the special unknown shapes of tidal flats. We will clarify the efficiency that spatio-temporal sedimental changes can be extracted through processing satellite images. Therefore, the spatio-temporal unknown topography change monitoring using satellite images is expected to be very useful to clarify whether the tidal flat is generated or not in the Go-Gunsan Islands at the outer side of the embarkment after constructing completely the Saemangeum tidal embarkment.

• Journal of Advanced Marine Engineering and Technology
• /
• v.35 no.8
• /
• pp.1048-1054
• /
• 2011

Laser surface hardening process is the method of hardening surface by inducing rapid self quenching of laser injected area through transfer of surface heat to inside after rapid heating of laser injected area only by high density energy heat source. This surface treatment method does not involve virtually any thermal deformation by heat treatment nor accompanies any other process after surface hardening treatment. In addition, allowing local machining, this method is a surface treatment method suitable for die with complicated shape. In this study, die material cast iron was surface-treated by using high power diode laser with beam profile suitable for heat treatment. Since the shapes of die differ by press die process, specimens were heat-treated separately on plane and corner depending on the applied parts. At this time, corner heat treatment was done with optic head inclined at $10^{\circ}$. As a result, corner heat treatment easily involves concentration of heat input due to limitation of heat transfer route by the shapes compared with plane part, so the treatment accomplished hardening at faster conveying speed than plane heat treatment.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.33 no.6
• /
• pp.427-434
• /
• 2009

A new surface shape of an internal cooling passage which largely reduces the pressure drop and enhances the surface heat transfer is proposed in the present study. The surface shape of the cooling passage is consisted of the concave dimple and the riblet inside the dimple which is protruded along the stream-wise direction. Direct Numerical Simulation (DNS) for the fully developed turbulent flow and thermal fields in the cooling passage is conducted. The numerical simulations for five different surface shapes are conducted at the Reynolds number of 2800 based on the mean bulk velocity and channel height and Prandtl number of 0.71. The driving pressure gradient is adjusted to keep a constant mass flow rate in the x direction. The thermoaerodynamic performance for five different cases used in the present study was assessed in terms of the drag, Nusselt number, Fanning friction factor, volume and area goodness factor in the cooling passage. The value of maximum ratio of drag reduction is -22.86 %, and the value of maximum ratio of Nusselt number augmentation is 7.05% when the riblet angle is $60^{\circ}$. The remarkable point is that the ratio of Nusselt number augmentation has the positive value for the surface shapes which have over $45^{\circ}$ of the riblet angle. The maximum volume and area goodness factors are obtained when the riblet angle is $60^{\circ}$.

• Fashion & Textile Research Journal
• /
• v.18 no.2
• /
• pp.235-243
• /
• 2016

This study is a preliminary study to suggest a distinguished fitted sloper according to body types. To this end, this study classified body types of men in their 20s in an attempt to examine the characteristics of each type. A total of 842 adult men of age 20 to 29 were studied by using the direct measurement data taken in the 6th Size Korea. The subjects' body types were classified based on 48 measurements. We extracted a total of six factors that characterized the body types of adult men in their 20s: horizontal size, vertical length, shoulder development, trunk area length, hip area length and shoulder slope. Result of the cluster analysis, the body shapes of men in their 20s were classified into four types. We developed the overlapped silhouettes for each of the four body types and compared the front and side shapes to clearly identify the differences of each body types. The findings of this study indicated that Korean adult men in their 20s can be classified into the big inverted triangular type that represents healthy and muscular men, the small inverted triangular type that represents short and skinny men, the triangular type that represents men with abdominal obesity, and the rectangular type that represents men that are fat overall, with a fairly even distribution of each body type.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.37 no.11
• /
• pp.999-1007
• /
• 2013

The present work reports numerical results of the pressure drop and heat transfer characteristics of pipes with various shapes such as circular, elliptical, circumferential wavy and twisted using a three-dimensional simulation. Numerical simulations are calculated for laminar to turbulent flows. The fully developed flow in pipes was modeled using steady incompressible Reynolds-averaged Navier-Stokes (RANS) equations. The friction and Colburn factor of each pipe are compared with those of a circular tube. The overall flow and heat transfer calculations are evaluated by the volume and area goodness factor. Finally, the objective of the investigation is to find a pipe shape that decreases the pressure loss and increases the heat transfer coefficient.

• Journal of the Korean GEO-environmental Society
• /
• v.9 no.5
• /
• pp.83-89
• /
• 2008

This study is to figure out the speed of soil diffusion and shapes as well when landslide occurred. It was measured the speed and shapes of soil diffusion using installed indoor-simulation of a land slide. Standard sand was used to measure it and this measurement is following the moisture content of standard sand. The result of this experiment follows the moisture content; as the moisture content goes up, the area and speed of soil diffusion goes faster as well. As the average of records by the moisture content was analyzed, the area and speed of land slide are increased proportionally. The shape of diffusion is formed as fanwise. It depends on the moisture content as above; the speed was fast when the moisture content is high, and it was getting narrower and longer as the speed of diffusion was faster.

• Proceedings of the KSME Conference
• /
• 2008.11b
• /
• pp.2465-2470
• /
• 2008

A new surface shape of an internal cooling passage which largely reduces the pressure drop and enhances the surface heat transfer is proposed in the present study. The surface shape of the cooling passage is consisted of the concave dimple and the riblet inside the dimple which is protruded along the stream-wise direction. Direct Numerical Simulation (DNS) for the fully developed turbulent flow and thermal fields in the cooling passage is conducted. The Numerical simulations for the 5 different surface shapes are conducted at the Reynolds number of 2800 based on the mean bulk velocity and channel height and Prandtl number of 0.71. The driving pressure gradient is adjusted to keep a constant mass flow rate in the x direction. The thermo-aerodynamic performance for the 5 different cases used in the present study was assessed in terms of the drag, Nusselt number, Fanning friction factor, Volume and Area goodness factor in the cooling passage. The value of maximum ratio of drag reduction is -22.86 [%], and the value of maximum ratio of Nusselt number augmentation is 7.05 [%] when the riblet angle is $60^{\circ}$ (Case5). The remarkable point is that the ratio of Nusselt number augmentation has the positive value for the surface shapes which have over $45^{\circ}$ of the riblet angle. The maximum Volume and Area goodness factor are obtained when the riblet angle is $60^{\circ}$ (Case5).

• Transactions of the Korean Society of Automotive Engineers
• /
• v.14 no.5
• /
• pp.107-114
• /
• 2006

This paper investigates the radiating source of electro-magnetic waves in the cabin of automobile with spark ignition engine. Front seats are very close to the engine room where electro-magnetic waves are expected to be radiating. But front seat area is believed to be a blind zone, which is not affected by radiating electro-magnetic waves, because a bulk board and floor board shield the front seat area. The level and frequency spectrum of electro-magnetic waves are measured at the passenger seat and the engine room. The measured frequency range is $145{\sim}365MHz$. As a results, the level of the electro-magnetic waves of automatic transmission vehicle is greater than -82dBm. The shapes of frequency spectrum of both engine room and passenger seat are look alike. But the level of electro-magnetic waves of manual transmission vehicle is less than -82dBm and the shapes of frequency spectrum of engine room and passenger seat are different to each other. From these results, we can say that any mal-function caused by electro-magnetic waves in the automobile cabin are only possible for automatic transmission vehicle. Also, it is believed that the radiating source of electro-magnetic waves is inside the vehicle. Thus, based on the transmission line theory, this paper presumably concludes that the cables which connect all the components inside a automatic transmission vehicle must be a radiating source of electro-magnetic waves in the cabin.