• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.406-412
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• 2018

In this paper, we propose a narrow resonant waveguide probe that can improve the measurement sensitivity in near-field scanning microwave microscopy. The probe consists of a metal waveguide incorporating the following two sections: a straight section at the tip of the probe whose cross-section is a double-ridged rectangle, and whose height is much smaller than the waveguide width; and a standard waveguide section. The advantage of the narrow waveguide is the same as that of the quarter-wave transformer section i.e., it achieves impedance-matching between the sample under test (SUT) and the standard waveguide. The design procedure used for the probe is presented in detail and the performance of the designed resonant probe is evaluated theoretically by using an equivalent circuit. The calculated results are compared with those obtained using the finite element method (Ansoft HFSS), and consistency between the results is demonstrated. Furthermore, the performance of the fabricated resonant probe is evaluated experimentally. At X-band frequencies, we have measured the one-dimensional scanning reflection coefficient of the SUT using the probe. The sensitivity of the proposed resonant probe is improved by more than two times as compared to a conventional waveguide cavity type probe.

• Journal of Chest Surgery
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• v.10 no.2
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• pp.205-213
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• 1977

In order to evaluate the therapeutic effect of thoracostomy on the patients with pathological changes in pleural cavity which were caused by various etiological factors, a clinical study was carried out during a period of 5 and half years from May 1972 to September 1977 in the department of thoracic surgery, Hanyang University Hospital, and the following results were obtained. Of a total of 264 patients, 205 cases were male, and 59 female, exhibiting the ratio of male to female being 3.5 to 1. The pathological changes in pleural cavity could occur at any age from 4 months after birth to 76 years old, the peak incidence being in the third decade in either male or female. The incidence decreased in the second, fifth and fourth decade in order. The type of pathological changes observed and their frequencies of occurrences were 93 cases [35.2%] in pneumothorax, 62 cases [23.5%] in hemothorax, 48 cases [18.2%] in pyothorax, 46 cases [17. 4%] in hemopneumothorax, 13 cases [4.9%] in hydropneumothorax, and one case each in hydrothorax and chylothorax. The incidence of the primary diseases which predisposed the pathological changes in pleural cavity were, 119 cases [45-1%] in trauma, 64 cases [24.2%]in lung tuberculosis, 38 cases [14.4%] in pneumonia or empyema, 14 cases [5.3%] in lung emphysema and blebs, 13 cases [4.9%] in process after thoracotomy, 3 cases [1.1%] each in lung malignant tumor and lung paragonimiasis, one case in mechanical ventilator and 9 cases [3.4%] in unknown origin. The pathological changes in pleural cavity were located in the right side of the cavity in 124 cases, in the left side in 133 cases and in both sides in 7 cases, indicating that the difference between the incidence of the left and rightside occurences was insignificant. Of 93 cases of pneumothorax studied, 63 cases were found to have been tension pneumothorax and 30 cases non-tension pneumothorax, showing greater prevalence of tension type over non-tension type. Of 119 cases of trauma observed, 82 cases were accompanied with rib fractures and 37 cases were without any fracture [non-bone fracture]. Patients with the rib fractures were characterized by multiple rib fractures and multiple double fractures of ribs, accompanying with or without fracture of bones other than ribs, and patients with non-bone fracture were characterized by penetrating stab wound and blunt trauma. Of 264 cases who received thoracostomy, 207 cases [78.4%] demonstrated that their pathological changes in pleural cavity were removed and subsided by a simple measure of thoracostomy. In 43 cases [16.3%], various surgical measures including radical operation and thoracotomy were required for complete healing, since their pathological changes were not abolished by thoracostomy alone. The rest 14 cases [5.3%] were expired following thoracostomy.

• Bulletin of the Korean Chemical Society
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• v.19 no.11
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• pp.1222-1227
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• 1998

The crystal structure of a benzene sorption complex of fully dehydrated Cd2+-exchanged zeolite X, Cd46Si100Al92O384·43C6H6 (a=24.880(6) Å), has been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd3 at 21 ℃. The crystal was prepared by ion exchange in a flowing stream of 0.05 M aqueous Cd(NO3)2 for 3 d, followed by dehydration at 400 ℃ and 2 x 10-6 Torr for 2 d, followed by exposure to about 92 Torr of benzene vapor at 22 ℃. The structure was determined in this atmosphere and refined to the final error indices R1=0.054 and Rw=0.066 with 561 reflections for which I > 3σ(I). In this structure, Cd2+ ions are found at four crystallographic sites: eleven Cd2+ ions are at site 1, at the centers of the double six-oxygen rings; six Cd2+ ions lie at site I', in the sodalite cavity opposite to the double six-oxygen rings; and the remaining 29 Cd2+ ions are found at two nonequivalent threefold axes of unit cell, sites Ⅱ' (in the sodalite cavity ) and site Ⅱ (in the supercage) with occupancies of 2 and 27 ions, respectively. Each of these Cd2+ ions coordinates to three framework oxylkens, either at 2.173(13) or 2.224(10) Å, respectively, and extends 0.37 Å into the sodalite unit or 0.60 Å into the supercage from the plane of the three oxygens to which it is bound. The benzene molecules are found at two distinct sites within the supercages. Twenty-seven benzenes lie on threefold axes in the large cavities where they interact facially with the latter 27 site-Ⅱ Cd2+ ions (Cd2+-benzene center=2.72 Å; occupancy=27 molecules/32 sites). The remaining sixteen benzene molecules are found in 12ring planes; occupancy=16 molecules/16 sites. Each hydrogen of these sixteen benzenes is ca. 2.8/3.0 Å from three 12-ring oxygens where each is stabilized by multiple weak electrostatic and van der Waals interactions with framework oxygens.

• Bulletin of the Korean Chemical Society
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• v.16 no.6
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• pp.539-542
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• 1995

The crystal structure of K92-X (K92Al92Si100O384), a=25.128(1) Å, dehydrated at 360 ℃ and 2X 10-6 Torr, has been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd&bar{3} at 21(1) ℃. The structure was refined to the final error indices R1=0.044 and Rw=0.039 with 242 reflections for which I<3σ(I). In this structure, ninety-two K+ ions are located at the five different crystallographic sites. Sixteen K+ ions are located at the centers of the double six rings (site I; K(1)-O(3)=2.65(2) Å and O(3)-K(1)-O(3)=92.0(6)°). About twelve K+ ions lie at site I' in the sodalite cavity opposite double six rings (D6R's) and these K+ ions are recessed ca. 1.62 Å into the sodalite cavity from their O(3) plane (K(2)-O(3)=2.74(2) Å, O(3)-K(2)-O(3)=88.5(8)°). About thirty-two K+ ions are located at the site II in the supercage and these K+ ions are recessed ca. 1.20 Å into the supercage from their O(2) plane (K(3)-O(2)=2.64(2) Å, and O(2)-K(3)-O(2)=101(1)°). About twenty-two K+ ions lie at the site III in the supercage opposite 4-ring ladder and the remaining ten K+ ions lie at the site III' near the 4-ring ladder in the supercage (K(4)-O(4)=2.88(3) Å, O(4)-K(4)-O(4)=79.8(9)°, K(5)-O(4)=2.8(2) Å, and O(4)-K(5)-O(4)=68(5)°).

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.1
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• pp.46-53
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• 2001

The prevalence of supernumerary teeth is between $1{\sim}3%$. Of these, $90{\sim}98%$ occur in the maxilla with particular predilection for the premaxilla, preceded by mandibular third premolars, mandibular forth molars and maxillary paramolars. The most common ones occur in the maxillary anterior region, they may occur singly between the central incisors(mesiodens), or they may be double(mesiodentes). Maxillary anterior supernumeraries may erupt into the oral cavity or remain unerupted. It is found that approximately 25% are erupted, while the rest are unerupted. They are usually a small tooth with a cone-shaped crown and a short root. They may cause delayed eruption, median diastema, bodily displacement or rotation of the adjacent permanent teeth. Occasionally they may lead to the developement of dentigerous cyst or primordial cyst, or eruption into nasal cavity. In this study, 109 supernumeraries surgically extracted from premaxilla in 84 patients are analysed. The results are as follows : 1. Sex distribution of male and female is 2.2 : 1. 2. Almost cases are in pediatric age from 5 to 12 years old (87%). 3. Problems with supernumeraries are tooth malpositon, diastema, delayed eruption, eruption to nasal cavity and cyst formation. 4. Of 109 supernumeraries, 16(15%) are erupted into oral cavity, 92(84%) are impacted, and 1(1%) is erupted into nasal cavity. 5. Of 84 patients, 59(70%) have one supernumeray while 25(30%) have two supernumeraries. 6. Of 109 supernumeraries, 96(88%) are found within the region of the central incisors. 7. Of 109 supernumeraries, 94(86%) are vertically impacted, 11(10%) are horizontally impacted, 3(3%) are labiopalatally impacted and 1(1%) is impacted in nasal cavity. 8. Of 84 patients, we used palatal flap in 67(80%), labial flap in 6(7%), both flaps in 4(5%) and no flap in 7(8%). And incisive nerve was cut in 33(49%) of 67 palatal flaps. 9. Extration with ostectomy was done in 72 supernumeraries(66%), without ostectomy in 37 teeth(34%). 10. Extraction with tooth sectioning was done in 21 supernumeraries(19%), without tooth sectioning was done in 88 teeth(81%). 11. We used local anesthesia in 70 patients(83%) and general anesthesia in 14 ones(17%).

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.21 no.2
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• pp.128-132
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• 2010

Background and Objectives : This study was designed to examine the effect of nasal cavity surgery on voice in terms of nasalance by using subjective test, Visual analogue scale (VAS) and Nasometer and compare the pre op and post op results among patiets with nasal cavity disease. Materials and Method : From April 2009 to November 2009, data of thirty one patients who underwent nasal cavity surgery were prospectively evaluated. 24 males and 7 females with age range between 12 years to 80 years old (average 34 years old) were chosen. VAS was questioned to patients group before, after 1 week, after 1 month, and after 3 months from the surgery. Nasometer, was also conducted. Results: After the surgery symptoms like nasal obstruction, mouth breath, snoring, and sleep apnea were all improved. Improvements for nasal obstruction and mouth breath were observed statistically in post operative day (POD) 1 month and POD 3 months. Also snoring was improved statistically in POD 1 month. Objective nasalance test showed increases in a single and double vowel for POD 3 months. Only /je/ sound statistically-significant increased in all post operative periods. Nasalance increase were observed in other test results. Conclusion : All the symptoms are improved after nasal cavity surgery. Also there are some nasalance changes during whole period of study and return to the pre operative state in POD 3 months. Therefore, patients must be warned and understood about nasalance changes, and surgeons need to aware of various facts, which can affect voice changes before the surgery.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.3
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• pp.163-168
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• 2023

An oroantral fistula (OAF) or oroantral communication (OAC) is an opening between the oral cavity and the maxillary sinus. If left untreated, these openings may cause chronic maxillary sinusitis. Although small defects (diameter <5 mm) may close spontaneously, larger communications require surgical intervention. Various studies have been conducted on OAC closure using a platelet-rich fibrin (PRF) membrane; most of these prior studies have involved simple direct application of PRF clots. This study introduces a new "double-barrier technique" using PRF for closure of an OAF involving sinus mucosal lifting and closure. The PRF material is inserted into the prepared maxillary sinus space, and the buccal advancement flap covers the oral side. This technique was successfully used to treat two patients with chronic OAF in the posterior maxillary region after implant removal or tooth extraction. The use of a PRF membrane in a double-barrier technique may have advantages in soft-tissue healing and could enable easy closure of chronic OAF with minimal trauma.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.5
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• pp.454-458
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• 2010

Velopharyngeal insufficiency is defined as a status in which nasal cavity and oral cavity can not be sepa-rated when speaking, swallowing by any reason. It has been treated by palatorrhaphy, pharyn-geal flap, local flap, free flap etc. When the size of the defect is small, it can be restored by palatorrhaphy, pharyngeal flap etc. But they are not proper for treatment of the large size of defect. In that case, local flap and free flap are more beneficial. Although large defect can be restored by free flap technique, but it is very complex, time-consuming and may bring about esthetical, functional complications of donor site. Buccinator myomucosal flap is a kind of local flap and reported for the first time by Bozola et al in 1989 and it has become a useful way for reconstruction of large intraoral defect. Authors experienced the use of buccinators myomucosal flap for treating secondary velopharyngeal insufficiency with large soft palate defect and obtained good result. So we report the case with literature reviews.

• Journal of Electrical Engineering and Technology
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• v.10 no.5
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• pp.2120-2125
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• 2015

In this paper, a rectangular waveguide probe with a ridge-loaded straight slot (RLSS) is presented for a near-field scanning microwave microscope (NSMM). The RLSS is located laterally at the end wall of the cavity and is loaded on double ridges in a narrow straight slot to improve the spatial resolution compared with a straight slot. The probe consists of a rectangular cavity with an RLSS and a feed section of a WR-90 rectangular waveguide. When the proposed NSMM is located at distance of 0.1mm in front of a substrate without patches or strips, the simulated full width at half maximum (FWHM) of the probe improve by approximately 31.5 % compared with that of a straight slot without ridges. One dimensional scanning of the E-plane on a sample under test was conducted, and the reflection coefficient of the near-field scanning probe is presented.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.89-91
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• 2015

Observed spectra of stars around the Sun have indicated that the Sun is located in a gas cavity, extending to 100pc. This gas cavity is called the "Local Bubble". The density of the interstellar medium (ISM) in the local bubble is about one tenth that of the average for the ISM in the Milky Way. Furthermore, some structures such as gas planes and strings in the local bubble are probably the result of supernovae. These, due to their low temperatures, can not be observed in the visible and infrared. The only way to do so is to measure the spectra of nearby stars so that the light of stars passing through the local bubble is absorbed by existing gas and the resulting spectral lines from absorption can be measured. In this study, we use binary stars to trace the local bubble structures through lines such as the Na I Doublet. First, we determined the observed spectral lines of stars by HARPS and FEROS echelle spectrographs. Then, we made synthetic spectra with the ATLAS9 code. Finally, the difference between the observational and synthetic spectra confirms the existence of the Na I Doublet in the local ISM.