• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.93-102
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• 2018

This paper reports a Surge Protective Device (SPD) that is used to protect an automatic metering interface (AMI) power supplies of communication equipment on a low-voltage distribution system from a lightning current. The surge protective device (SPD) can be classified as one-port SPDs and two-port SPDs with decoupling elements depending on the connection type. The protection of internal systems against the lightning current may require a systematic approach consisting of coordinated SPDs. To deal with this, the definition of a lightning protection zone (LPZ) was studied and interpreted through a theoretical review. Because the lightning current resulting from a lightning surge is considerably high, there is limited protection from one SPD; therefore, coordinated cascaded MOV-based SPDs are installed to solve this problem. Regarding the power grid mentioned in this paper, a class II SPD for the low-voltage distribution system installed on the border of LPZ1 and LPZ2, which establish a protection coordination with the Arrester (LA, SA) that corresponds to the LPZO installed on the MOF stage connected to one system were designed to protect various communication (control) equipment, including the automatic meter reading system inside the branch-type electric supply panel of a building, not the incoming side of one system. In addition, performance-related tests were done by a comparison with the existing method through testing, and the optimal design was achieved for the 1-port SPD that uses a series connection and can bleed load current without any decoupling element.

• The KIPS Transactions:PartC
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• v.14C no.7
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• pp.571-582
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• 2007

Vehicular ad-hoc networks is temporarily established through inter-vehicle communication without any additional infrastructure aids. It requires a immediate message propagation because it mainly deals with critical traffic information such as traffic accidents. The distance-based broadcast scheme is one of the representative broadcast schemes for vehicular ad-hoc network. In this scheme, a node to disseminate messages is selected based on a distance from a source node. However, a message propagation delay will be increased if the relay nodes are not placed at the border of transmission range of the source node. In particular, when the node density is low, the message propagation delay is getting longer. In this paper, we propose a time-window reservation based relay node selection scheme. A node receiving the alert message from the source node has its time-window and randomly selects its waiting time within the given time-window range. A proportional time period of the given time-window is reserved in order to reduce the message propagation delay. The experimental results show that the proposed scheme has shorter message propagation delay than the distance-based broadcast scheme irrespective of node density in VANET. In particular, when the node density is low, the proposed scheme shows about 26% shorter delay and about 46% better performance in terms of compound metric, which is a function of propagation latency and network traffic.

• The Korean Journal of Zoology
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• v.29 no.1
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• pp.23-30
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• 1986

Animals in Order Decapoda consist of a plentiful species and vary in external and internal shape, taste, feeding habit and the feature of alimentary canal. In this case, the morphological study on the midgut epithelium of filter feeding Decapoda in Crustacea, Korean fresh water crayfish (Cambaroides similis Koelbel), the only species dwelling in Korea, were performed by scanning electron microscopy. The anterior-most parts of midgut epithelium appeared to be many shallow, dense and irregular folds where a linear microvilli (MV) (1-3$\\mu$m long) numbered from a few to ten had raised. Middle part of the gut, the folds got gradually shallower. MV arranging on one, two or three lines were slightly thicker than those mentioned above. The number of MV in each group seemed gradual decrease from a apical border with maximum thirty in group to furrow with none. From the middle to posterior parts of the gut, the MV were slightly thinner and longer (2.5-4 $\\mu$m long) and raised twelve on a line and, in some cases, added from one to five on another line. On the posterior-end parts of the gut, the epithelium showed many shallow and dense folds as the anterior parts again. A group of thin and long MV (2-7 $\\mu$m long) countable fifteen on a line were raised to the base of each fold. In some cases, the MV also added utmost in five on the other line. All the MV observed in this study were posteriorly directed.

• Korean Journal of Veterinary Research
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• v.26 no.1
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• pp.1-9
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• 1986

This study was carried out to investigate the branch and distribution of Nervus facialis of the Korean native goat. The observation was made by dissection of embalmed cadavers of ten Korean native goats. The results were as follows; 1. N. facialis arose from the ventrolateral surface of the medulla oblongata. 2. In the facial canal, N. facialis gave off N. petrosus major, N. stapedius and Chorda tympani. 1) N. petrosus major arose from Ganglion geniculi, passed through the pterygoid canal and terminated in Ganglion pterygopalatinum. 2) Chorda tympani joined N. lingualis at the lateral surface of the internal pterygoid muscle. 3. At the exit of the stylomastoid foramen, N. facialis gave off N. caudalis auricularis, Ramus auricularis internus, Ramus stylohyoideus and Ramus digastricus. 1) N. caudalis auricularis arose by two branches in 6 cases and by a single branch in 4 cases. N. caudalis auricularis gave off branches to the caudoauricuIar muscles and the internal surface of the conchal cavity. 2) Ramus auricularis internus arose by a single branch except in 2 cases in which it arose in common with N. caudalis auricularis. It penetrated the caudolateral surface of the tragus and distributed in the skin of the scapha. 3) Ramus stylohyoideus and Ramus digastricus arose separately from N. facialis. 4. In the deep surface of the parotid gland, N. facialis divided into N. auriculopalpebralis, Ramus buccalis dorsalis and Ramus buccalis ventralis. In 6 cases, N. facialis gave off Ramus buccalis ventralis and then divided into N. auriculopalpebralis and Ramus buccalis dorsalis. In 3 cases, N. facialis trifurcated into Ramus buccalis ventralis, Ramus buccalis dorsalis and N. auriculopalpebralis. In one case, N. facialis gave off N. auriculopalpebralis and then divided into Ramus buccalis dorsalis and Ramus buccalis ventralis. 1) Ramus buccalis ventralis ran along the ventral border of the masseter muscle and distributed to the buccinator and depressor labii inferioris muscles. Ramus buccalis ventralis communicated with a branch of Ramus buccalis dorsalis and N. buccalis. In 2 cases, it also communicated with N. mylohyoideus. 2) Ramus buccalis dorsalis communicated with Ramus transverses faciei, N. buccalis, N. infraorbitalis and a branch of Ramus buccalis ventralis. Ramus buccalis dorsalis distributed to the orbicularis oris, caninus, depressor labii inferioris, levator labii superioris, buccinator, malaris, nasolabialis and zygomaticus muscles. 3) N. auriculopalpebralis gave off Rami auriculares rostrales, which supplied the zygomaticoauricularis muscle, the frontoscutularis muscle and the skin of the base of the ear. N. auriculopalpebralis then continued as Ramus zygomaticus, which innervated the frontal muscle, the lateral surface of the base of the horn, the orbicularis oculi muscle and the adjacent skin of the orbit. N. auriculopalpebralis communicated with Nn. auriculares rostrales and Ramus zygomaticotemporalis. In 7 cases, it also communicated with N. infratrochlearis.

• Journal of Chest Surgery
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• v.43 no.4
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• pp.413-416
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• 2010

A 47-year-old man presented with complaints of chest pain and dyspnea caused by deceleration injury due to an automobile accident. Systolic cardiac murmur was audible at the right sternal border. An electrocardiogram showed sinus tachycardia. Transthoracic echocardiography revealed a flailing anterior leaflet of the tricuspid valve, papillary muscle rupture, and severe valve insufficiency. Rupture of papillary muscle of the anterior leaflet and chordae tendineae of the posterior leaflet were confirmed by right atrial incision under routine cardiopulmonary bypass. Artificial chordae tendineaes were implanted between the anterior and posterior leaflet and papillary muscles in the right ventricles. De-Vega annuloplasty was also added. This is a very rare case in which a surgery was done for tricuspid valve regurgitation caused by post-traumatic papillary muscle rupture.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.33.1-33.7
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• 2019

Background: The concept of the ideal morphology for the alveolar bone form is an important element to reconstruct or restore the in maximizing esthetic profile and functional alveolar bone restoration. The purpose of this preliminary study is to evaluate the normal alveolar bone structure to provide the standard reference and guide template for use in diagnosing for implant placement, determining the correct amount of bone augmentation in actual clinical practice and producing prostheses based on three-dimensional imaging assessment of alveolar bone. Methods: This study was included 11 men and 11 women (average age, 22.6 and 24.5 years, respectively) selected from among 127 patients. The horizontal widths of alveolar bone of maxilla and mandible were measured at the crestal, mid-root, and root apex level on MDCT (multi-detector computed tomography) images reconstructed by medical imaging software. In addition, tooth dimensions of the central incisors, canines, second premolars, and first molars of maxilla and mandible, including the horizontal width of the interdental alveolar bone crest, were also measured and statistically analyzed. Results: The horizontal alveolar bone width of the palatal side of maxilla showed a distinct increment from the alveolar bone crest to the apical region in both anterior and posterior areas. The average widths of the maxillary alveolar ridge were as follows: central incisor, 7.43 mm; canine, 8.91 mm; second premolar, 9.57 mm; and first molar, 12.38 mm. The average widths of the mandibular alveolar ridge were as follows: central incisor, 6.21 mm; canine, 8.55 mm; second premolar, 8.45 mm; and first molar, 10.02 mm. In the buccal side, the alveolar bone width was not increased from the crest to the apical region. The horizontal alveolar bone width of an apical and mandibular border region was thinner than at the mid-root level. Conclusions: The results of the preliminary study are useful as a clinical guideline when determining dental implant diameter and position. And also, these measurements can also be useful during the production of prefabricated membranes and customized alveolar bone scaffolds.

• Journal of Oral Medicine and Pain
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• v.37 no.1
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• pp.1-7
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• 2012

Burning mouth syndrome(BMS) refers to a chronic orofacial pain disorder usually unaccompanied by mucosal lesions or other clinical signs. Tongue(anterior and lateral border) is found to be the most common site for the burning sensations in the oral cavity, and various oral sites may be affected including hard palate and lips. The etiology of this disorder remains poorly understood, but the various factors might be related with the pathogenesis of the BMS. These factors have been devided into local, systemic and psychological. Recently, there have been increasing reports that the pain of BMS may be neuropathic in origin. The complex and multifactorial etiology of BMS necessitates multidisciplinary approach for the management of these patients. Recently, several studies have reported that oral parafunctional habits could be related the pathogenesis of BMS, and tried to control the symptom of BMS with various methods. We reported the cases who had the symptom of burning mouth syndrome with removable anti-nociceptive appliance in the lower dentition.

• Imaging Science in Dentistry
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• v.34 no.2
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• pp.75-79
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• 2004

Purpose: To compare the proliferation potential of the epithelial cells between unicystic ameloblastoma (UA), dentigerous cyst (DC), and odontogenic keratocyst (OKC) and to correlate this proliferation potential with the radiographic features of these three pathoses. Materials and Methods: Immunohistochemical expression of PCNA, Ki-67, and cytokeratin as a proliferation marker were assessed for 15 cases of UA, 15 cases of DC, and 15 cases of OKC. The degree of immunochemical expression of three proliferation markers were correlated with the radiographic features, especially cortical expansion (negative and positive) and shape of border (scalloped and round). Results: Using PCNA and Ki-67, OKC showed the highest proliferation potential and UA the lowest. Statistically significant differences were found between the OKC and the UA (p < 0.05). However, no statistically significant difference was present according to the radiographic features in all pathoses. Using cytokeratin, there was no significant differences of proliferation potential among three pathoses. Conclusions : OKC epithelium has the most intense proliferation potential, followed by the dentigeous cyst and then unicystic ameloblastoma. There is no significant relation between the radiographic features and the proliferation potential of epithelium of these three pathoses.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.5
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• pp.446-454
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• 2000

Condylar process of mandible is an important and fuctionally versatile part of the mandible. There were quite large amount of investigations on the functional and anatomical adaptation of the temporomandibular joint(TMJ) to the surrounding tissues. But controversies on the mechanism of functional adaptation of the joint still exist. In this research, we investigated changes in the TMJ by the lateral deviation of the maxillary incisor to shift the mandible right, and bone the undecalcified microscopic sections with fluorescent microscope and von Kossa staining with bright field microscope. Results were as follows: 1. Lateral deviation rendered shifting and tilting of the mandible, There were, compressions in the right joint and opening of the left joint space at early stage. At the same time, both condyles shifted slightly to anterior. 2. After $2{\sim}4$ weeks, left condyle showed anterior displacement and compressions in the joint space. Right condyle showed only slight shift to the anterior. 3. Regardless of the direction of the lateral shift, anterior bite plate compressed both condyle heads until 2 weeks. 4. There are bone resorptions in the anterior aspect of the condyle head and apposition of posterior border. Bone remodeling were observed between 3 and 4 weeks. 5. After 8 weeks of the experiment, there were little differences in condylar morphology between experimental and control group, though slight shifting and compression were still present in the experimental group. Lateral deviation of mandible evoked active remodeling of the TMJ until functional and anatomical reconstruction of TMJ position was achieved.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.4
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• pp.301-307
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• 2004

The flap considered at first for the reconstruction of large maxillary defect, especially mid-face defect, is scapular free flap, because it provides ample composite tissue which can be designed 3-dimensionally for orbital, facial and oral reconstruction. In case of maxillary defect involving hard palate, however, this flap has some limitations. First, its bulk prevents oral function and physio-anatomic reconstruction of nasal and oral cavity. Second, mobility and thickness of cutaneous paddle covering the alveolar area reduce retention of tissue-supported denture and give rise to peri-implantitis when implant is installed. Third, lateral border of scapula that is to reconstruct maxillary arch and hold implants is straight, not U-shaped maxillary arch form. To overcome these problems, new concept of step prefabrication technique was provided to a 27-year-old male patient who had been suffering from a complete hard palate and maxillary alveolar ridge defect. In the first stage, scapular osteomuscular flap was elevated, tailored to fit the maxillary defect, particulated autologous bone was placed subperiosteally to simulate U-shaped alveolar process, and then wrapped up with split thickness skin graft(STSG, 0.3mm thickness). Two months later, thus prefabricated new flap was elevated and microtransferred to the palato-maxillary defect. After 6 months, 10 implant fixtures were installed along the reconstructed maxillary alveolus, with following final prosthetic rehabilitation. The procedure was very successful and patient is enjoying normal rigid diet and speech.