• Restorative Dentistry and Endodontics
• /
• v.35 no.4
• /
• pp.273-284
• /
• 2010

The objective of this study was to observe the histology of dental pulp healing after tooth replantation in rats. The maxillary right first molars of 4-week-old rat were extracted, and then the teeth were repositioned in the original socket. At 3 days after replantation, there was localized inflammatory reaction. But, pulp revasculization and healing had already begun in the root area. At 5 days after replantation, odontoblast-like cells were observed. Tertiary dentin deposition was observed beneath the pulp-dentin border from 1 week after replantation. And tertiary dentin was increased at 2 weeks after replantation. The presence of odontoblast-like cells and the formation of tertiary dentin were continued to 4 weeks after replantation. At 4 weeks after replantation, the deposition of bone-like tissues and cementum-like tissues was observed. This results show that there is a possibility of pulp healing after tooth replantation in rats and the mineralization of tooth can progress. The mineralization of tooth after replantation was initially occurred by the deposition of tertiary dentin, but as time passed, the deposition of bone-like tissues and cementum-like tissues was begun and increased.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.37 no.3
• /
• pp.176-183
• /
• 2011

Introduction: Very high aggressiveness and recurrence are important clinical characteristics of ameloblastoma compared to the other benign tumors. Therefore, an accurate diagnosis and treatment plan is important. This study examined the association of the clinical findings and recurrence based on the radiological findings of ameloblastoma. In recurrent cases, these results are expected to help in the diagnosis and treatment of ameloblastoma to examine the relevance with the clinical characteristics and radiological features. Materials and Methods: For a clinical (gender, age) and radiological (location, internal pattern, size, perforation, border pattern, impacted tooth, root resorption) evaluation, this study examined 156 cases of 147 patients diagnosed with ameloblastoma, who had been treated and in most cases regularly checked at the department of oral and maxillofacial surgery, Kyungpook National University Hospital, between January 1993 and December 2009. For a recurrent rate evaluation, a more than 3 years follow-up period is needed. Accordingly, 116 patients diagnosed with ameloblastoma between January 1994 and December 2007 were investigated. Results: The recurrence rate in all cases was 6.1% but was 7.8% in cases with follow-up periods more than 3 years. The male-to-female ratio was 3:2, showing a slight male predilection. Ameloblastoma had a peak occurrence in the second decade of life followed by the fourth decade of life. The mandibular angle area is the most frequent site of ameloblastoma (50.8%) in the jaws. Six cases of unilocular (7.8%) and 3 cases of multilocular (7.7%) ameloblastomas recurred. Seven cases of smooth (10%) and 2 cases of irregular (4.3%) ameloblastomas recurred. No cases of ameloblastomas without perforation of the cortical bone (0%) and 9 cases with a perforation of cortical bone (11.1%) recurred. Four cases of the ameloblastomas with impacted teeth (11.4%) and 5 cases of ameloblastomas without impacted tooth (6.2%) recurred. Seven cases of ameloblastomas with root resorption (10.9%) and 2 cases of ameloblastomas without root resorption (3.8%) recurred. Conclusion: A multiple smooth margin, unilocular ameloblastoma with an impacted tooth, root resorption tends to recur more easily. Therefore, they need to be treated more carefully and require a a longer follow-up.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.39 no.6
• /
• pp.263-268
• /
• 2013

Objectives: The interforminal region, between the mandibular foramen, is known as a relatively safe area that is free of anatomic structures, such as inferior alveolar nerve, submandibular fossa, and lingual side of the mandible is occasionally neglected for its low clinical importance. Even in the case of a severely constricted alveolus, perforation of the lingual cortical bone had been intended. However, anterior extension of the inferior alveolar canal, important anatomic structure, such as concavity of lingual bone, lingual foramina, and lingual canal, has recently been reported through various studies, and untypical bleeding by perforation of the lingual plate on implantation has also been reported. Therefore, in this study, we performed radiographic and statistical analysis on distribution and appearance frequencies of the lingual foramina that causes perforation of the mandibular lingual cortical bone to prevent complications, such as untypical bleeding, during surgical procedure. Materials and Methods: We measured the horizontal length from a midline of the mandible to the lingual foramina, as well as the horizontal length from the alveolar crest to the lingual foramina and from the lingual foramina to the mandibular border by multi-detector computed tomography of 187 patients, who visited Dankook University Dental Hospital for various reasons from January 1, 2008 to August 31, 2012. Results: From a total of 187 human mandibles, 110 (58.8%) mandibles had lingual foramina; 39 (20.9%) had bilateral lingual foramen; 34 (18.2%) had the only left lingual foramen; and 37 (19.8%) had the only right lingual foramen. Conclusion: When there is consistent bleeding during a surgical procedure, clinicians must consider damages on the branches of the sublingual artery, which penetrate the lingual foramina. Also, when there is a lingual foramina larger than 1 mm in diameter on a pre-implantation computed tomography, clinicians must beware of vessel damage. In order to prevent these complications and progress with a safe surgical procedure, a thorough radiographic examination before the surgery is indispensable. Further, clinicians should retract lingual flap definitely to confirm the shape of the lingual bone and existence of the lingual foramina.

• Journal of the Korea Society for Simulation
• /
• v.22 no.3
• /
• pp.1-6
• /
• 2013

The ecosystem is the complex system consisting of various biotic and abiotic factors and the factors interact with each other in the hierarchical predator-prey relationship. Since the competitive relation spatiotemporally occurs, the initial state of population density and species distribution are likely to play an important role in the stability of the ecosystem. In the present study, we constructed a lattice model to simulate the three-trophic ecosystem (predatorprey- plant) and using the model, explored how the ecosystem stability is affected by the initial density. The size of lattice space was $L{\times}L$, (L=100) with periodic boundary condition. The initial density of the plant was arbitrarily set as the value of 0.2. The simulation result showed that predator and prey coexist when the density of predator is less than or equal to 0.4 and the density of prey is less than or equal to 0.5. On the other hand, when the predator density is more than or equal to 0.5 and the density of prey is more than or equal to 0.6, both of predator and prey were extinct. In addition, we found that the strong nonlinearity in the interaction between species was observed in the border area between the coexistence and extinction in the species density space.

• Journal of Digital Convergence
• /
• v.14 no.12
• /
• pp.645-655
• /
• 2016

The purpose of this study is to analyze the roles and functions of NGO 's International Solidarity in the establishment of' DMZ World Peace Park ', the mechanism of operation, and the policy formation of NGO' s international solidarity. The establishment of the DMZ World Peace Park is a matter that can be achieved as a result of dialogue efforts between the two parties based on the agreement between the DPRK and the ROK government, but should take a more relaxed approach to the process issues in order to achieve such results And should be done in a long-term, step-by-step plan. In the process of realizing this, South Korea's own efforts alone are difficult, and it is necessary to seek various channels of dialogue with the international community so that North Korea can have dialogue negotiations. This will be the role of NGO, It should be noted. As a result, in order to establish 'DMZ World Peace Park', it is necessary to establish concrete road map of DMZ World Peace Park. In the first stage, it is necessary to organize and operate 'DMZ World Peace Park Promotion Committee' under the directorship of the President or Prime Minister, It is necessary to select candidates, to appeal to North Korea and to support the international community, and to participate voluntarily by the private sector. Phase 2 requires final settlement. Phase 3 will require a step-by-step road map, such as rapid construction of the Peace Park, expansion of peaceful use of the DMZ, and expansion of ecology, history and cultural tourism in the DMZ border area.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.49 no.1
• /
• pp.29-38
• /
• 2012

The noise generated in the process of obtaining the medical image acts as the element obstructing the image interpretation and diagnosis. To restore the true image from the image polluted from the noise, the total variation optimization algorithm was proposed by the R.O. F (L.Rudin, S Osher, E. Fatemi). This method removes the noise by fitting the balance of the regularity and fidelity. However, the blurring phenomenon of the border area generated in the process of performing the iterative operation cannot be avoided. In this paper, we propose the adaptive total variation method by mapping the control parameter to the proposed transfer function for minimizing boundary error. The proposed transfer function is determined by the noise variance and the local property of the image. The proposed method was applied to 464 tooth images. To evaluate proposed method performance, PSNR which is a indicator of signal and noise's signal power ratio was used. The experimental results show that the proposed method has better performance than other methods.

• Journal of the Korean Geographical Society
• /
• v.47 no.1
• /
• pp.79-97
• /
• 2012

This study examines on the impact of biodiversity in circular greenspace of Cheongju city since 2002 greenbelt release. Research has carried out to investigate the biotope pattern change with landscape fragmentation. Major landscape fragmentation has occurred with development of residential sector and build-up of major highways. Settlement has been expanded to the entire area connected to urban district excluding the eastern forest. North-south district shows high road density, where inter-regional roads meet in the cross-section. It is found that landscape fragmentation impact on species richness as well as population size of the species varies depending on the animal species. The birds show high species richness in N2, N3, N4, S2(north-south zone) even with high fragmentation rate. This can be explained that birds can access to aquatic environment where they can find abundant food resources. The amphibians and the reptiles show almost no zonal variation in species richness than the birds. The more a zone fragmented in small patches, the species richness of the amphibians and the reptiles also tends to be declined. Information accumulation on biodiversity for integrating landscape planning in urban planning, various level of community participation in decision making process, and cross border cooperation with neighbouring Cheongwon-gun will be required for sustainable greenspace management of Cheongju City.

• Korean journal of applied entomology
• /
• v.49 no.4
• /
• pp.325-331
• /
• 2010

Attractiveness of stink bugs to various colors, heights and locations of fish-net traps incorporated with aggregation pheromones was determined. Bean bug, Riptortus pedestris Fabricius, was most attracted to yellow color trap, followed by white, black, green, blue and brown. R. pedestris and one-banded stink bug, Piezodorus hybneri Gmelin, were most attracted to fish-net traps placed 80 cm above the ground regardless of sexes of two species of stink bugs. Between the sexes, however, R. pedestris females were more attracted to 40 and 80 cm above the ground than the males at those heights although the attraction was not significantly different at 120 and 160 cm heights. P. hybneri females tended to be attracted to 40 and 80 cm height traps but the attraction was the opposite at 120 and 160 cm heights. The highest attraction of R. pedestris was observed in a perilla field with no significant difference in the soybean field and border area in which no crop were cultivated between the perilla and soybean fields. R. pedestris was also more attracted to the sweet persimmon orchard than the soybean and medicinal crops fields, which was a significant difference between the two fields.

• The Korean Journal of Mycology
• /
• v.26 no.1 s.84
• /
• pp.31-38
• /
• 1998

Since 1990, destructive yellow rots on Ganoderma lucidum caused by a soilborne fungus have been occurred in major cultivation areas of Korea. Incidences of the disease were 61% in Chulwon and 94% in Kanghwa area where the mushroom has been cultivated for 10 years, whereas the disease has not been found yet in new cultivation areas such as Moonkyung and Hongsung. when severely infected, inner tissues of bed-logs showed severe yellow and fruiting bodies of the mushroom was not produced. Infected tissues of bed-logs were readily distinguished from those of healthy ones by a distinctive brown border line. When the disease progressed, mycelia of Ganoderma lucidum were totally destroyed, and abundant ascocarps of the pathogen were formed inside the tissues of bed-logs showing yellowish green. The fungus derived from a single ascospore strongly lysed mycelia of Ganoderma lucidum growing on bottle media, and non-volatile components secreted by the pathogen were also highly inhibitory to mycelial growth of the mushroom fungus. The pathogen was identified as Arthrographis cuboidea based on its distinctive cultural and morphological characters. The fungus produced arthroconidia and unbrached conidiophores. The width of fungal conidia was distinctively wide as compared with the length. Colonies of the fungi were pale yellow to yellowish green on agar media. As a causal pathogen of yellow rot of Ganoderma lucidum., this fungus has not been reported yet in Korea.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.40 no.1
• /
• pp.57-68
• /
• 2012

This research was conducted to understand the extent to which visitors to the DMZ Pyeonghwa Nuri-gil Trail(located in one of the most Ecologically Sensitive Areas(ESA) of Korea) are motivated by perceived constraints and loyalty to the trail. Self-administered questionnaires were distributed to the participants of the '2010 DMZ Border Trekking Course', which resulted in collecting 317 valid responses. For statistical tests, the respondents were divided into three clusters(accidental, activity-driven, and nature-driven) by their motivation for the visit. ANOVA was conducted to examine if the three groups differ in terms of the perceived constraints and loyalty to the DMZ Pyeonghwa Nuri-gil Trail. The results showed that nature-driven visitors were more likely to perceive "psychological constraints" than accidental or activity-driven visitors. As for loyalty, accidental visitors displayed the lowest level of loyalty while nature-driven visitors indicated the highest level of loyalty. These results illustrate that nature-driven visitors not only have the strongest desire to experience and learn about ESAs but also possess the highest sense of loyalty to the trail. It can further be argued that nature-driven visitors are the ones with the greatest concern for the trail's well-being. The paper concludes with the contention that understanding the demand and characteristics of trail visitors is critical to the future development of the trail.