• ETRI Journal
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• v.33 no.2
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• pp.163-168
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• 2011

A Fabry-Perot cavity (FPC) antenna producing both high-gain and circularly-polarized (CP) behavior is proposed. To increase antenna gain and obtain CP characteristics, a superstrate composed of square patches with a pair of truncated corners is placed above the linearly polarized patch antenna with an approximately half-wavelength distance from the ground plane at the operating frequency. The proposed antenna has the advantages of high gain, a simple design, and an excellent boresight axial ratio over the operating frequency bandwidth. Moreover, used in an FPC antenna, the proposed superstrate converts a linear polarization produced by a patch antenna into a circular polarization. In addition, the cavity antenna produces left-hand circular-polarization and right-hand circular-polarization when a patch antenna inside the cavity generates x-direction and y-direction polarization, respectively. The measured and simulated results verify the performance of the antenna.

• The Journal of Advanced Prosthodontics
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• v.15 no.6
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• pp.302-314
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• 2023

PURPOSE. The aim of this study was to classify the shapes of retromolar pads and assess their morphometric differences using a 3D model. MATERIALS AND METHODS. Two hundred fully edentulous or Kennedy Class I partially edentulous patients (400 retromolar pads) were enrolled. Scan data of the definitive mandibular casts produced through functional impressions were obtained using a 3D laser scanner. Seven parameters (transverse diameter, longitudinal diameter, transverse-contour length, longitudinal-contour length, longitudinal/transverse diameter ratio, longitudinal/transverse-contour length ratio, and angle of the retromolar pad line to the residual alveolar ridge line) were measured using image analysis software. Subsequently, the pads were classified according to the shape. Statistical analyses were performed using 95% confidence intervals. RESULTS. Classifying the retromolar pads into three shapes led to high intra-examiner reliability (Cronbach's alpha = 0.933). The pear shape was the most common (56.5%), followed by oval/round (27.7%) and triangular (15.8%) shapes. There were no significant differences between the left and right sides according to the shape and no significant differences in any parameter according to age. The transverse diameter and longitudinal/transverse diameter ratio differed between sexes (P < .05). The triangular shape had a significantly different transverse diameter, transverse-contour length, longitudinal/transverse diameter ratio, and longitudinal/transverse-contour length ratio compared with the pear and oval/round shapes (P < .05). CONCLUSION. From a clinical reliability standpoint, classifying retromolar pads into three shapes (oval/round, pear-shaped, and triangular) is effective. The differences in the sizes among the shapes were attributed to the transverse measurement values.

• The Journal of Korean Academy of Prosthodontics
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• v.22 no.1
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• pp.33-50
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• 1984

The purpose of this study was to investigate whether the ashed tooth powder is utilized as an alternative material of the implant to recovery the bony defect. For this purpose its biocompatibility was evaluated comparing to the synthetic calcium phosphate compounds, such as Syntograft and Calcitite, as well as the vacuum firing porcelain (Ceramco Inc.) which is anticipated to use as a matrix to aid sintering. Bony defects to exposure the bone marrow, $3{\times}5$ mm in size, were created in the right and left tibias of fifteen rabbits, and then the ashed tooth powder at $950^{\circ}C$, the porcelain powder, Syhtograft and Calcitite were inserted in the defects of twelve rabbits of the experimental group and the blood clot only was filled in the defects of three rabbits of the control group. The experimental and control rabbits were sacrificed at 1st, 2nd 3rd week after implantation and the histologic examination was performed. The ashed tooth powder in order to make the needed form of the implant was molded using the cylindrical mold 1 cm high, 1 cm in diameter under the pressure of $1000kg/cm^2$ and the ashed tooth powder was sintered at $1100^{\circ}C$ for 1 hour and the mixture of the porcelain powder and the ashed tooth powder at the weight ratio of 7:3, 6:4, 5:5, 4:6 were molded in the same manner and were sintered at $925^{\circ}C$. From this sintered material, square shaped implants were prepared in the dimension of $2{\times}4{\times}6mm$. The prepared implants were surgically placed in the subperiosteum of lateral surfaces of the right and left mandibular bodies. The dogs were sacrificed at 4 weeks, and then the specimens were examined using the light and scanning electron microscopes. The results of this study were obtained as follows: 1. Any inflammatory response was not noted after implanting of the ashed tooth powder, Syntograft, Calcitite and the porcelain powder during the whole experimental period after implantation. 2. Induction of the new bone formation was significantly shown in the ashed tooth powder, Syntograft and Calcitite. 3. The more the porcelain powder was contained in the implants, the more the porosity was and the bigger the pore size was under the scanning electron microscope. And there was ingrowing of the fibrous connective and the osteoid tissue. 4. The osteoid tissues were found to be directly fused to the implant of the ashed tooth powder, and the mixture implant of the porcelain powder and the ashed tooth powder at the weight ratio of 4:6 under the light and scanning electron microscopes.

• Korean Journal of Cleft Lip And Palate
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• v.7 no.1
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• pp.35-46
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• 2004

The frequency of abnormality at birth is average 1-1.5%, and of these, cleft lip & palate is known to be the most frequent congenital abnormality, Cleft is considered to be due to multi-factorial heredity correlated with genetic and environmental factors, Cleft patients require the collaborative treatment with several medical departments, Clinics for Maxillo-Oral Disorders of Tohoku University Dental Hospital performs the total managements related to such as occlusion and language for the patients with congenital maxilla-facial abnormality, This study examined the patients with cleft lip and/or palate who came to the Clinics for Maxilla-Oral Disorders of Tohoku University Dental Hospital for the past 17 years from Jan. 1987 to Dec, 2002, and had the results as follows, 1. Annual mean number of patients The annual mean number of the patients for 17 years from Jan, 1987 to Dec, 2002 was 91 patients, ranging from 63 minimum to 116 maximum, 2, Gender and types of cleft There were 747(51%) males and 709(49%) females, with a male to female ratio 1,05:1. CLP was the most frequent cleft type as shown in 616 patients, and other patients manifested different complaints such as CL, CP, SMCP and MC in order. 3. The laterality in cleft type The lip cleft was frequently expressed orderly on left, right and both sides of CL patients while orderly being shown on left, both and right sides of CLP patients. Accordingly, lip cleft was most commonly found on the left side. 4. Address at first visit Of 1,456 subjects, 850(58.4%) patients were residing in Miyagi Prefecture, where this hospital is located. 5. Age at first visit 615(42.2%) patients came to the hospital at their age younger than 1 year old, comprising 282(19.4%) patients age younger than 2 months old and 333(22.9%) patients age between 2 month old and 1 year old. 6. Mother's age at birth For the mother's age at birth, 526(39.9%) patients were at the age of 25 to 30 years old, and 17(1.3%) patients were over 40 years old. 7. Birth weight 34.3%(443 patients) had a birth weight of 2500-3000gm and 56.0%(724 patients) had a 3000-4000gm. It was also found that 7.9%(102 patients) had a birth weight of less than 2500gm. 8. Familial expression The frequency of familial expression was 6.5%(94 patients).

• Journal of Biomedical and Translational Research
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• v.19 no.4
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• pp.79-85
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• 2018

Echocardiography is one of the most useful diagnostic techniques for differentiating heart disease as well as mitral valve lesion. Forty client-owned small breed dogs (weight, 2.3-13.2 kg) aged between 8-17 years with myxomatous mitral valve degeneration (MMVD) were included in the present study. The diagnosis of MMVD in dogs was made based on the clinical signs, chest radiography data, and echocardiographic findings. Echocardiographic examinations were conducted in accordance with recommended standards for dogs. M-mode, Doppler, and 2D echocardiography were performed in left and right lateral recumbency. 2D echocardiography was used to measure LA and Ao diameter from 2D short axis at the level of the aortic valve. In the comparison of conventional echocardiography indices in dogs with different stages of heart failure with MMVD, significant differences were observed in E/A ratio (p=0.005), EDV (p<0.001), EDVI (p<0.001), E-peak velocity (p= 0.001), ESV (p=0.028), ESVI (p=0.004), LA (p<0.001), LA/Ao Ratio (p<0.001), LVIDd (p<0.001), LVIDd/Ao Ratio (p<0.001), LVIDs (p=0.036), LVIDs/Ao Ratio (p=0.002), and MR Velocity (p=0.026). In addition, distinct correlations were found in EDV (r=0.712), LA/Ao ration (r=0.830), LVIDd (r=0.724), and LVIDd/Ao ratio (r=0.759). This study found that known conventional echocardiographic indices, including EDV, LA/Ao ratio, LVIDd dimension, and LVIDd/Ao ratio correlated with the severity of MMVD in point of significant differences and distinct correlations.

• Journal of Yeungnam Medical Science
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• v.14 no.1
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• pp.101-110
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• 1997

The maximal voluntary strength of knee extension and flexion on both the right and left sides was measured in patients with hemiparesis of upper motor neuron type and in a group of normal subjects. Significant differences of maximal voluntary strength were found between male and female but the ratio of flexor to extensor strength did not vary significantly between the sides, between the sex in normal subjects. The maximal voluntary strength of uninvolved side were not reduced significantly but involved side reduced significantly in patients. The ratio of flexor to extensor strength in hemiparetic side was significantly less than the ratio for the normal subjects but not significant difference in uninvolved side of patients. According to the above results, the maximal voluntary strength of flexion was more reduced than that of the extension in lower extremity of hemiparesis patients. The strength ratio of flexion to extension was a useful parameter for guiding the rehabilitation of hemiparesis.

• Journal of Korean Physical Therapy Science
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• v.6 no.1
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• pp.897-903
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• 1999

Many out patients of the rehabilitation center complaint a pain caused by suffering of MPS, and it brings many different kind of social and ecinomical problems such as medical expenses and the reduction in work efficiency. Therefore, we conducted a research to present a fast and effective treatment to the MPS patients. this research was conducted from November, 1996 to January 1998 with eighteen outpatients who agreed to be the subjects to our reserach. We applied the electric acupuncture on 28 different trigger point on the patients with mostly muscular-skeletal pain and some tender and radiating pain. After the treatment, VRS, VAS, PRI were used to measure the degree of the pain on the patients third and seventh visits, and following results were found. 1. To apply EAP treatment, we acupunctured 6em-Iong needles on Tps region, then the electrodes of pulse generater pg-306 E.S.T were connected on the top of the needles. the electric acupuncture therapy was conducted for 20 minutes with the intensity of 4hz - 60hz(auto wave). The treated electric intensity was the level at which the patients did not feel discomfort. 2. Thirteen out of the 18 participated patients were in their 30s and 40s(72.2%), showing highest frequency. There were more female than male with the ratio of 1 to 1:2. 3. six out of the participated patients (33.3%) had the pain for less then a week, and the average duration of the pain of the participated patients wear 0.8 years. 4. The pain occured mostly in the upper trapezius by 6 part (21.4%), then in the gluteus medius region by 4 part (14.3%). Many of the patients with the pain in the upper back area accompanied varios kind of the referred pains such as radiculopathy, HIVD and Frozen shoulder. 5. MPS occured more frequently on the right side than left side then left side and it seemed to be due to the frequent use of the right hand. 6. There was almost no difference in the measurement of the intensity of the pain right before and after the EAP treatment. Howerver, there was significant decrease in the numerical values of the VAS, and a little bit of decrease in the numerical values of the PRI after the EAP treatment. 7. Based on the results of this present research, it can be concluded that EAP can be used for the treating the myofascial pain syndrome with promptness and safety in most cases.

• The Korean Journal of Nuclear Medicine
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• v.31 no.1
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• pp.36-42
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• 1997

Though myocardial perfusion was usually expected to improve after coronary artery bypass graft(CABG) surgery, some myocardial segments were aggravated after operation, as we compared perfusion changes on postoperative SPECT with preoperative ones. In this study, we evaluated perfusion changes after operation in rest and stress myocardial SPECT in 44 patients (M:F=25:19, age 57.1 $year{\pm}8.2$) who had CABG before and 3 months after operation. We tried to find out possible causes for perfusion aggravation with multivariate logistic regression analysis regarding whether bypass graft was artery or vein and which coronary artery territory was operated. Among 616 myocardial segments which were operated, 89(14.4%) aggravated after operation. In the univariate analysis, myocardial segments in the left circumflex arteries(LCx) aggravated more often(p<0.01) than others and segments having operative angioplasty did less often(p<0.01). Multivariate logistic regression revealed that LCx was risk factor for perfusion aggravation [odds ratio=2.54 (95% confidence interval : 1.53-4.22, p<0.01)]. However, this was not the case when we analysed in terms of arterial territories. Among 106 coronary arterial territories which were operated, 27(25.5%) aggravated. The territories having aggravated had similar characteristics regarding whether they received arterial or venous grafts, angioplasty and whether the operated territories were left anterior descending, right coronary or left circumflex arteries. In conclusion, myocardial segments in the left circumflex artery tended to aggravate more often after bypass surgery than the others. In short-term comparison of perfusion after surgery, we could not find any tendency that arterial or venous graft was associated with more frequency of the aggravation of perfusion after operation.

• Progress in Medical Physics
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• v.18 no.1
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• pp.42-47
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• 2007

Purpose: To evaluate the tracing of optic nerve tract using manganese enhanced magnetic resonance Imaging. Materials and Methods: After injecting $30{\mu}l$ of $MnCl_2(1mol)$ (1 mol) Into the retina of female New Zealand white rabbit, the contrast enhancements at major anatomical structures of optic nerve tract were evaluated by high resolution T1-weighted Images 12 hours, 24 hours, and 48 hours after $MnCl_2(1mol)$ Injection using 3D FSPGR (Fast Speiled Gradient Recalled echo) pulse sequence at 1.5T clinical MR scanner with high performance gradient system. Also, for quantitative evaluation, the signal-to-noise ratios of circular ROI on anatomical locations were measured. Results: The major structures on the optic nerve tract were enhanced after injecting $MnCl_2(1mol)$. The structures, which showed enhancement, were right optic nerve, optic chiasm, left optic tract, left lateral geniculate nucleus, left superior colliculus. The structures on the contralateral optic pathway to the right retina were enhanced whereas the structures on the ipsilateral pathway did not show enhancement. Conclusion: The Mn transport through axonal pathway of optic nerve sys)em was non- invasively observed after injecting injecting $MnCl_2$ at the retina, which is the end terminal of optic nerve system. This Mn transport seems to occur by voltage gated calcium $(Ca^{2+})$ channel and In case of direct Injection Into the retina, the fast transpori pathway of voltage gated calcium channel seems to be responsible for Mn transport.

• The Journal of the Acoustical Society of Korea
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• v.41 no.1
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• pp.108-113
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• 2022

Speech recognition in noise situation is an important skill for effective communication. Hearing In Noise Test (HINT) has been suggested as a clinical tool to evaluate these aspects. However, this tool has not been used widely in domestic clinics. In this study, psychophysical aspects of HINT and burdens in clinical application were analyzed to improve the applicability of the tool. The difficulty in understanding speech in the elderly population is due to hearing loss based on aging of peripheral and central auditory pathways. As typical clinical cases, HINT scores for young and elderly listeners (20s vs 70s) were compared. Four conditions of HINT test were Quiet (Q), Noise Front (NF), Noise Right (NR), and Noise Left (NL). Quantitative scores showed that the elderly listener required more Signal to Noris Ratio (SNR) values than the younger counterpart in noisy situations. Although both showed Binaural Masking Level Difference (BMLD) effect, the strength was smaller in the elder. However, the age-matched normalized data were not established in detail for clinical application. Confirmed usefulness of HINT and the related improvement in clinical measuring procedure were suggested.