• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.4
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• pp.493-498
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• 2004

A novel approach for path planning of a polygonal robot is presented. Traditional path planners perform extensive geometric searching to find the optimal path or to prove that there is no solution. The computation required to prove that there is no solution is equivalent to exhaustive search of the motion space, which is typically very expensive. Humans seems to use a set of several different path planning strategies to analyse the situation of the obstacles in the environment, and quickly recognize whether the path-planning problem is easy to solve, hard to solve or has no solution. This human path-planning strategies have motivated the development of the presented algorithm that combines qualitative shape reasoning and exhaustive geometric searching to speed up the path planning process. It has three planning stages consisting of identification of no-solution cases based on an enclosure test, a qualitative reasoning stage, and finally a complete search algorithm in case the previous two stages cannot determine of the existence of a solution path.

• Korean Journal of Veterinary Research
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• v.38 no.3
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• pp.497-507
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• 1998

The localizations and morphological characteristics of immunoreactive cells for prolactin(PRL) and growth hormone(GH) antisera were studied with double immunohistochemistry in the adenohypophysis of the Korean native goat. PRL immunoreactive cells(mammotropes) and GH immunoreactive cells(somatotropes) were present in the pars distalis and pars tuberalis, but not in the pars intermedia. A few cells were stained with both PRL and GH antisera (somatomammotropes). The possessional percentages of mammotropes, somatotropes and somatomammotropes were 37.0%, 32.6%, 1.0% in females and 35.6%, 32.6%, 1.1% in males, respectively. Mammotropes were oval or round in shape, and $10{\sim}20{\mu}m{\times}17{\sim}25{\mu}m$ in size. These cells were distributed throughout the pars distalis, but were more abundant on the dorsal part adjacent to the hypophyseal cavity and along the lateral and ventral peripheral regions. Somatotropes were elliptical, triangular or polygonal in shape, and $8{\sim}17{\mu}m{\times}17{\sim}18{\mu}m$ in size. The distribution pattern of somatotropes was similar to that of mammotropes. Some somatomammotropes were intercalated between clusters of mammotropes while the others were dispersed independently among the secretory cells.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.2
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• pp.133-139
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• 2017

The timing chain system, which is a typical power transmission technology applied to a vehicle, has been widely used by the automotive industry because it is normally designed to last a car's lifetime. However, the timing chain system may cause some problems due to the shape of the chains and the polygonal behavior on contact between the chain and the sprocket. In addition, noise and vibration caused by transmission error are the most typical problems encountered by major automotive manufacturers and they are considered as the main source of customer complaint. The initial tension of the chain-sprocket system is thought to be the main cause of transmission error, and it is regarded as the source of engine vibration and noise. The initial tension of the chain system should be controlled carefully since a low initial tension can cause twisting, which may lead to a system malfunction, while a high initial tension can reduce the service life due to a worn down contact surface. In this paper, the kinematic analysis model is generated with various initial tensions, which are controlled by changing the shape of the fixed guide with the largest contact surface with chain. The results showed that the transmission error was minimized on a particular range of initial tension, and the tendency showed that the error changed with a higher sensitivity at a lower initial tension.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.1
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• pp.23-26
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• 2006

Effects of sera from several fish species and insulin on the development of cultured Silurus asotus hepatocytes were investigated. Hepatocytes with high viability (95%) were obtained from the livers of male catfish by two step collagenase perfusion. Isolated hepatocytes, initially showed a typical round-shape, firmly attached to the culture dish within 24 h. In the presence of catfish serum, hepatocytes attached each other, spread well on the dish and developed into monolayer after 3-4 days of incubation. Cells within the established monolayer became polygonal in shape and their nuclei and boundaries being clearly visible under the microscope. In contrast, when incubated in FBS-supplemented or serum-free medium, cells managed to form small clusters, each made of 2-10 cells. Cells in FBS-supplemented medium further developed into larger clusters. However, these clusters failed to develope into monolayer. In addition, when insulin was deprived from culture medium, formation of monolayer also failed. From these data, it can be concluded that the presence of both catfish serum and insulin is necessary for the formation of monolayer of catfish hepatocytes and the functional role of fish serum may differ from that of insulin and can not be displaced by FBS-supplementation.

• Journal of Embryo Transfer
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• v.22 no.4
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• pp.229-234
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• 2007

This study was undertaken to determine the normal appearance of the postpartum uterine involution. Postpartum changes in uterine shape, architecture, echogenicity and diameter were monitored with ultrasonography in 8 Miniature Schnauzer dogs. Vaginal discharge was observed visually during the 3 weeks of postpartum. A large amount of viscous dark green discharge changed progressively to a small amount of transparent discharge. In the uterine shape, the transverse images were crescent or polygonal at the beginning, but became circular after 16 days. At postpartum day 24, the longitudinal images of placental and interplacental sites were similar to each other The echogenicity of uterine structure was clearly distinguishable among the hyperechoic serous membrane, hypochoic myometrium, hyperechoic endometrium, and anechoic uterine contents during the first week postpartum, but afterward the interluminal boundaries and echogenicity became obscure gradually. In addition, the anechoic substance of the endometrial cavity was not observed after postpartum day 28. In the uterine diameter, the diameter of placental sites decreased markedly from 24 mm at the first day postpartum to 13 mm at day 7, and the diameter of interplacental sites decreased from 15 mm at postpartum day 1 to 10 mm at day 7. At postpartum day 65, the uterus (6.4 mm) changed little and had a uniform homogenous echo, and thus it was confirmed that uterine involution was completed at that time in Miniature Schnauzer dogs.

• Parasites, Hosts and Diseases
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• v.25 no.2
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• pp.99-109
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• 1987

The present study was carried out to examine the effect of a calcinogen, aflatoxin B1 on the ultrastructural changes of ciliary epithelial cells in mice infected with Clonerchis sinensis. A total of 93 male albino mice(BALB/c strain) was divided into 3 groups; group I, treated with 1.0 ppm aflatoxin Bl for 12 weeks; group II, given 50 C. sinensis n;etacercariae, and group III, given 50 metacercariae and treated with 1.0 ppm aflatoxin Bl for 12 weeks. Three mice served for untreated-uninfected controls. From 4 weeks after the treatsment and/or in(ection, three mice from each group were sacrificed at 4 week intervals up to the 40th week, and their hepatobiliary tissues were prepared for transmission electron microscopy. The most prominent ultrastructural changes in group I were remarkable enlargement of nuclear size, separation of nucleolus, dispersed chromatin granules in nuclei and increased dense granules along the inner membrane of nuclei. In the cytoplasm there was slight proliferation of mitochondria and endoplasmic reticulum (ER) at earlier stage. At the 12th week separation of fibrillar and granular components of the nucleolus was a characteristic finding. As the time elapsed, epithelial cells showed fiattened-cuboidal form and a tendency of atrophy. Most of the nuclei were elongated and polygonal in shape. In group II the appearance of elaborate interwoven folds of lateral cytoplasm forming a labyrinth of interconnected intercellular space and variety in nuclear shape were the prominent fadings at earlier stage. The cytoplasm showed slight proliferation and dilatation of mitochondria and ER, and a small number of mucin droplets. In the basement membrane scanty fibrous cells were seen. With time, variety in nuclear shape, marked proliferation and dilatation of rough ER and some collagen fibrils were demonstrated. Other features of intracellular organelles and mucin droplets persisted. In group III cuboidal epithelial cells showed their remarkably enlarged and irregular nuclei, increased chromatin granules in the nuclei, separated nucleoli, proliferated and dilated rough ER. With time, sequestered mitochondria showed blob-like evaginations which lacked cristae and dense matrix, and were limited by a single membrane. Since the 20th week, microvilli were relatively scanty and poorly developed. Organelles and inclusions in the cytoplasm of metaplastic cells were poor. Nuclei were variable in shape. The nlost prominent changes at later stage were separation of nuclei from the cytoplasm, and appearance of numerous and irregularly angled electron dense granules in the nuclei.

• Applied Microscopy
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• v.36 no.3
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• pp.141-153
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• 2006

The purpose of this study is to find out how soft contact lens multi-purpose solution (MPS), often used for medical treatment, effects the inhibition on cell growth and research the result of using MPS, suspected to demage eye cells, on rabbit eye's corneal epithelium and endothelium tissue. In this treatise, $ReNu^{(R)}$ (Baush & Lomb, USA), Opti-free $express^{(R)}$ (Alcon, USA), Free-sol $plus^{(R)}$ (Hanamedicon, Korea) had been selected among the MPS. After culturing L929 roil line, cell growth inhibition rate was measured by MTT assay, and by making Hematoxylin and Eosin stain specimen. the morphology was observed by optical microscope. In the In vivo experiment,9 white rabbit eyes (18 eyes) were classified into 3 groups. The experimental group is left eyes (9 eyes) of rabbit, and MPS were dropped; however. the control group, the right eyes (9 eyes), were only used a saline solution without preservatives. After the dropping within the period, the cornea surface of rabbit eyes were stained by Rose bengal and observed. To figure out the changes of the corneal epithelium and endothelium tissue scanning electron microscopy (SEM) has been used. As the result, the rate of cell growth inhibition was 54%. 73% and 36%, respectively. Morphological changes represented that the shape has been changed into oval or round shape and those are not considered as a common formation of L929 cell line. When it comes to staining Rose bengal, each experiment group was stained red which is not shown in controls. The polygonal mosaic pattern of a corneal epithelium was disturbed in the picture taken by SEM; furthermore, the shape of the corneal endothelium was irregular. In conclusion, as we consider antimicrobial effect and the safety on living cells, it is necessary that we should improve concentration of preservatives and study continuously to develop a new preservatives without a toxic effect on the cornea surface.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.12
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• pp.894-906
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• 2006

There are many difficulties to develop a mobile contents due to many constraints on mobile environments. It is difficult to make a good mobile contents with only visual reduction of existing contents on wire Internet. Therefore, it is essential to devise the data representation and to develop the authoring tool to meet the needs of the mobile contents market. We suggest the compact mobile contents to learn Chinese characters and developed its authoring tool. The animation which our system produces is realistic as if someone writes letters with pen or brush. Moreover, our authoring tool makes a user generate a Chinese character animation easily and rapidly although she or he has not many knowledge in computer graphics, mobile programming or Chinese characters. The method to generate the stroke animation is following: We take basic character shape information represented with several contours from TTF(TrueType Font) and get the information for the stroke segmentation and stroke ordering from simple user input. And then, we decompose whole character shape into some strokes by using polygonal approximation technique. Next, the stroke animation for each stroke is automatically generated by the scan line algorithm ordered by the stroke direction. Finally, the ordered scan lines are compressed into some integers by reducing coordinate redundancy As a result, the stroke animation of our system is even smaller than GIF animation. Our method can be extended to rendering and animation of Hangul or general 2D shape based on vector graphics. We have the plan to find the method to automate the stroke segmentation and ordering without user input.

• Applied Microscopy
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• v.39 no.1
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• pp.41-48
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• 2009

We investigated the morphological characteristics of the pearlescent pigment by using scanning electron microscope, energy dispersive X-ray spectrometry and thermal analyzer. The result is that the shape of pigment is platy polygonal form through observing the pearlescent pigment by the scanning electron microscope. The size of pigment is various and not formed in standardized size or shape. The pigment flakes were measured about from $30{\mu}m$ to $300{\mu}m$. The tip of the piece of pigment is pointed shape or angled. The result of observing them by the scanning electron microscope in magnifying high power is that the edge and the lateral face of them is an round form and the measurement of thickness is about $9{\mu}m$. As well using the high magnification scanning electron microscope, the surface of the pigment flake observed like rugged as coating with the $TiO_2$ element, the diameter of the coating particle is around 60 nm, then the coating particle consists of granular substance. Analysis of the configuration elements of pearlescent pigment using by the energy dispersive X-ray spectrometry is that O, Si, C, Na, Ca, Ti, Zn detected in the surface of pigment and its lateral face identifies similar components. In thermal analysis, there are no contained quantity differences between them in beginning from $100^{\circ}C$ to $800^{\circ}C$ showing thermal analysis, 1.1% out of contained quantity reduced at $115^{\circ}C$, 1.7% dropped at $416^{\circ}C$, and 1.9% decreased at $797^{\circ}C$.

• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.653-664
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• 1999

This study was undertaken to determine the normal appearance of the postpartum uterine involution. Postpartum changes in uterine shape, architecture, echogenicity and diameter were monitored with ultrasonography in 11 Korea Jin-do dogs. Serial ultrasonographic examination was done daily during the first week, 3 days interval from 8 to 30 days, and weekly from 31 to 100 days postpartum, respectively. Of 11 postpartum bitches, 10 bitches (90.9%) had normal involution and 1 bitch (9.1%) had subinvolution of the placental sites (SIPS) by gross findings, vaginal discharges, and by ultrasographic findings, uterine shape and echogenicity. The excretory period of vaginal discharges in 10 normal bitches of uterine involution was finished completely at $20.2{\pm}4.6$ days (Mean${\pm}$SD) postpartum, but in 1 SIPS at 50 days postpartum. The short axis shape of the uterus was initially often flaccid-appearing. It varied from circular to crescent shaped to polygonal. This lasted until $16.5{\pm}3.7$ days postpartum, during which time the short axis uterine shape gradually changed to circular. Also, the long axis shape of the uterus was created a beaded appearance of the horns until $29.9{\pm}3.2$ days postpartum. After 30 days, it was appeared as tubular shape without distinguished between placental and interplacental sites. The ultrasonographic image of the postpartum uterus consisted of four echogenicity distinct layers. Uterine wall was represented the very hyperechoic serosa, hypoechoic myometrium, hyper echoic endometrium and anechoic structures of fluid in the uterine cavity until 7 days postpartum. The individual uterine layers were most prominent during the first week postpartum, and they became progressively less distinct throughout the course of uterine involution. Anechoic structures of fluid in the uterine cavity was detected until $25.0{\pm}6.4$ days postpartum, after which time it was not reliably detected. The uterine diameter was decreased not only in the placental sites frorm $24.1{\pm}2.5mm$ at 1 day to $15.4{\pm}1.4mm$ at 7 days postpartum, but also in the interplacental sites $14.9{\pm}1.5mm$ at 1 day, $10.6{\pm}0.8mm$ at 7 days postpartum. There was a general trend of decreasing uterine diameter, which occurred more rapidly at the placental sites. At 31 days pastpartum, these diameter reached almost same size, after that time, they could be not distinguished between placental and interplacental sites. At 87 days postpartum, the uterine diameter was $5.6{\pm}0.6mm$ both placental and interplacental sites, and the uterine horns were uniform hypoechoic, tubular structures without enlargement. Therefore, complete involution of the uterus occurred at that time. It was concluded that normal postpartum uterine involution in Korea Jin-do bitches appeared to be completed around 87 days postpartum by gross findings such as vaginal discharges, and by ultrasonographic findings, uterine shape and echogenicity. Also ultrasonographic characteristics of the postpartum uterine involution were described. Therefore, these result suggest that ultrasonographic assessment is a reliable method for diagnosing the SIPS and uterine dysfunction, such as pyometra in bitch.