• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.7
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• pp.6-13
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• 2006

Tin doped indium oxide(ITO) and Al doped zinc oxide(ZnO:Al) films, which are widely used as a transparent conductor in optoelectronic devices, were prepared by using the capacitively coupled DC magnetron sputtering method. ITO and ZnO:Al films with the optimum growth conditions showed each resistivity of $1.67{\times}10^{-3}[{\Omega}-cm],\;2.2{\times}10^{-3}[{\Omega}-cm]$ and transmittance of 89.61[%], 90.88[%] in the wavelength range of the visible spectrum. The two types of 5 inch-PDP cells with ZnO:Al and ITO transparent electrodes were made under the same manufacturing conditions. The PDP cell with ZnO:Al film was optimally operated in the mixing gas rate of Ne(base)-Xe(8[%]), and at gas pressure of 400[Torr]. It also shows the average measured brightness of $836[cd/m^2]$ at voltage range of $200{\sim}300$[V]. Luminous efficiency, one of the key parameter for high brightness and low power consumption, ranges from 1.2 to 1.6[lm/W] with increasing frequency of ac power supplier from 10 to 50[Khz]. The brightness and luminous efficiency are lower than those with ITO electrode by about 10[%]. However, these values are considered to be enough for the normal operation of PDP TV.

• Proceedings of the Korean Magnestics Society Conference
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• 2012.11a
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• pp.104-105
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• 2012

The temperature dependence of the effective magnetic anisotropy constant K(T) of ferrite nanoparticles is obtained based on the measurements of SQUID magnetometry. For this end, a very simple but intuitive and direct method for determining the temperature dependence of anisotropy constant K(T) in nanoparticles is introduced in this study. The anisotropy constant at a given temperature is determined by associating the particle size distribution f(r) with the anisotropy energy barrier distribution $f_A(T)$. In order to estimate the particle size distribution f(r), the first quadrant part of the hysteresis loop is fitted to the classical Langevin function weight-averaged with the log?normal distribution, slightly modified from the original Chantrell's distribution function. In order to get an anisotropy energy barrier distribution $f_A(T)$, the temperature dependence of magnetization decay $M_{TD}$ of the sample is measured. For this measurement, the sample is cooled from room temperature to 5 K in a magnetic field of 100 G. Then the applied field is turned off and the remanent magnetization is measured on stepwise increasing the temperature. And the energy barrier distribution $f_A(T)$ is obtained by differentiating the magnetization decay curve at any temperature. It decreases with increasing temperature and finally vanishes when all the particles in the sample are unblocked. As a next step, a relation between r and $T_B$ is determined from the particle size distribution f(r) and the anisotropy energy barrier distribution $f_A(T)$. Under the simple assumption that the superparamagnetic fraction of cumulative area in particle size distribution at a temperature is equal to the fraction of anisotropy energy barrier overcome at that temperature in the anisotropy energy barrier distribution, we can get a relation between r and $T_B$, from which the temperature dependence of the magnetic anisotropy constant was determined, as is represented in the inset of Fig. 1. Substituting the values of r and $T_B$ into the $N{\acute{e}}el$-Arrhenius equation with the attempt time fixed to $10^{-9}s$ and measuring time being 100 s which is suitable for conventional magnetic measurement, the anisotropy constant K(T) is estimated as a function of temperature (Fig. 1). As an example, the resultant effective magnetic anisotropy constant K(T) of manganese ferrite decreases with increasing temperature from $8.5{\times}10^4J/m^3$ at 5 K to $0.35{\times}10^4J/m^3$ at 125 K. The reported value for K in the literatures is $0.25{\times}10^4J/m^3$. The anisotropy constant at low temperature region is far more than one order of magnitude larger than that at 125 K, indicative of the effects of inter?particle interaction, which is more pronounced for smaller particles.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.3
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• pp.209-223
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• 2013

This study was to evaluate the stress distributions of prefabricated, customized abutments and fixtures according to their material and shape by three-dimensional finite element analysis. And to investigate the fatigue life and fracture characteristics. Mandibular models were fabricated by reconstruction of the CT scan of patients with normal occlusion. A total of six finite element models were designed, a load of 100 N was applied on the buccal cusps vertically, and 30 degree obliquely. 10 specimens each were fabricated for the more clinically widely used 4 type abutments and were loaded according to ISO 14801. Differences in stress distribution patterns were not found according to the materials of the abutments and fixtures. But a slight difference in the stress level was detected. Customized abutment groups showed lower crown stress levels. One-piece zirconia implant showed the lowest bone stress levels. In the fatigue test, highest values were measured in group 7. Prefabricated abutments showed less variation of fatigue life (P<0.05). Use of customized abutments can improve the fracture resistance of restorations. Especially, use of customized zirconia abutments reinforced by titanium screw connecting parts is recommended.

• The Journal of Korean Medicine
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• v.20 no.1 s.37
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• pp.66-74
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• 1999

It is known that obesity is associated with chronic adult disease including stroke. However the relationship between stroke and obesity has not been discussed sufficiently, The purpose of this study was to confirm whether the serum Leptin levels related to BMI and these were associated with serum lipid levels and other risk factors in stroke patients. The subjects were 68 stroke patients(male 36. female 32) hospitalized in the Department of Circulatory Internal Medicine, College of Oriental Medicine, Kyung Hee University, Seoul. Obesity was shown in 16 patients(24%) whose BMI were above 25. and in 15 patients(22%) who represented higher values than normal in serum Leptin levels. BMI correlated with serum Leptin level(p=0.04), with Triglyceride(p=0.019) and with Total lipid(p=0.001) significantly. Meanwhile serum Leptin levels significantly correlated with Total cholesterol(p=0.013) only. BMI in the group with a history of smoking was significantly lower than that of the non-smoking group(p=0.01). Serum Leptin levels were higher in the group with Hypertension than the non-Hypertension group(p=0.026), lower in the non-Drinking group(p=0.006) and the smoking group(p=0.001) than the drinking group and the non-smoking group. respectively. So we concluded that BMI significantly correlates with serum Leptin levels and serum lipid levels in stroke patients.

• Progress in Medical Physics
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• v.14 no.2
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• pp.74-80
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• 2003

The purpose of this study was to evaluate the performance of the teflon encapsulated TLD rod, which may be used in nuclear medicine for the direct in vivo measurements of radiation dose. We analyzed the influence of teflon encapsulation for measuring absorbed dose. An experiment was carried out to evaluate and observe the response of a LiF TLD-100 rod in a thin-wall teflon capsule at different depths in a solid phantom. An adult anthropomorphic phantom was used to measure the absorbed dose using thin teflon encapsulated TLD. The measurements of PDD-, and TMR in solid phantom and athe bsorbed dose in humanoid phantom performed with normal TLD were compared with values obtained by teflon encapsulated TLD. It was demonstrated that the difference of TL response of LiF in phantom with and without teflon thin-wall capsule was less than 3％ under the same conditions beyond the build-up region. However, significant differences were observed near the phantom surface because of the build-up effect caused by the thin-wall thickness of the teflon capsule. Thus, our study showed that the contribution of teflon thin-wall capsule to TLD response for the megavoltage photon beams was negligible and that it did not significantly effect dose measurement. The teflon encapsulated TLD described in this work has been proven to be appropriate for in vivo dosimetry in therapeutic environments.

• Radiation Oncology Journal
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• v.23 no.1
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• pp.17-21
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• 2005

Purpose : To evaluate the voices of irradiated patients with early glottic carcinoma and to compare these with the voices of healthy volunteers. Materials and Methods : The voice samples (sustained vowel) of seventeen male patients who had been irradiated for T1a glottic squamous carcinoma at least 1 year prior to the study were analyzed with objective voice analyzer (acoustic voice analysis, aerodynamic test, and videostroboscopic analysis) and compared with those of a normal group of twenty age- and sex-matched volunteers. Average fundamental frequency, jitter, shimmer, and noise-to-harmonic ratio were obtained for acoustic voice analysis. Maximal phonation time, mean flow rate, intensity, subglottic pressure, glottal resistance, glottal efficiency, and glottal power were obtained for aerodynamic test. Results : The irradiated group presented higher values of shimmer in acoustic voice analysis. There was no significant difference between two groups in other parameters. Conclusion : In this study all the objective voice parameters except shimmer were no4 significantly different between the irradiated group and the control group. These results suggest that the voice quality is minimally affected by radiation therapy for 71 a glottic carcinoma.

• Korean Journal of Environment and Ecology
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• v.30 no.2
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• pp.214-227
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• 2016

This study was conducted to classify the vegetation structure of the Geumsan in Namhae-gun. Using the phytosociological method and DCCA ordination, the vegetation was classified into 10 communities of natural forests (Quercus serrata, Carpinus tschonoskii, Q.mongolica, Pinus densiflora, P.thunbergii, C. turczaninowii, Q. variablis, Zelkova serrata, C.laxifora and Corylopsis gotoana var. coreana) and 2 communities of plantation forests (Chamaecyparis obtusa and Cryptomeria japonica). Among the communities other than the plantation forests, the importance value of Q. serrata (45.7) was found to be the highest. According to the results of DBH analysis among the species with high importance values, Q. serrata, Q. mongolica and C. tschonoskii showed normal patterns in the size-frequency distribution, suggesting that these species will continue to hold their current dominance. The average soil pH in the communities ranged from 4.28 to 4.76. The results of DCCA ordination analysis showed that Q. serrata was evenly distributed in the high and low elevation habitats. P. thunbergii and P. densiflora communities were mainly distributed in the lowest elevation habitats on the southern slope.

• Polymer(Korea)
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• v.31 no.3
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• pp.206-214
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• 2007

The theoretical study is developed for predicting the thermal expansion changes of composites which include complex inclusion, which is used three-dimensional ellipsoid model ($a_1>a_2>a_3$), which has two aspect ratios (the primary aspect ratio, $\rho_{\alpha}=a_1/a_3$ and the secondary aspect ratio, $\rho_{\beta}=a_1/a_2$). We can predict the feature of general thermal expansion factors by theoretical approach of matrix with aligned ellipsoidal inclusion using the Eshelby's equivalent tensor. The coefficients of longitudinal linear thermal expansion ${\alpha}_{11}$ decrease to those of inclusions, ${\alpha}_f$, as both aspect ratios increase. The coefficients of transverse linear thermal expansion of composites ${\alpha}_{33}$ initially increase and show the parabolic corves with maximum values, as the concentrations of filler increase. The coefficient of thermal expansion, ${\alpha}_{22}$ in the transverse direction decreases, as $\rho_{\alpha}$ increases, however, ${\alpha}_{22}$ increases as $\rho_{\beta}$ increases. The coefficient of linear thermal expansion of composites, ${\alpha}_{33}$ in the normal direction increases, as $\rho_{\alpha}$ increases, while ${\alpha}_{33}$ decreases as $\rho_{\beta}$ increases.

• Journal of Veterinary Clinics
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• v.17 no.2
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• pp.443-449
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• 2000

A three-year-old male jindo with generalized skin lesions (including seborrhea, hyperk- eratosis, alopecia, papules, and ecchymoses), pruritus lymph node enlargement, and fever was brought to Veterinary Teaching Hospital, College of Veterinary Medicine, Chungbuk National Uni- versity. There were no laboratory findings for parasites and fungi in the hair and skin But, the com- plete blood counts (CBC) showed leukocytosis and severe cosinophilia, It was suspected to be an inflammatory and allergic dermatitis. Thus, prednisoIone (0.5 mg/kg PO, BID for 1 week) and ampi- cillin (10 mg/kg PO, BID for 1 week given. One week later, pruritus and ecchymoses were reduced. These treatments were repeated for 7 day again. Three months later, the dog was presented again due to the relapse and exacerbation of the clinical signs. The signs were as follows; severe pru- ritus, vesicobullous skin lesions, anorexia, emaciation, lameness, and welling of carpal joints that showed inflammatory skin lesion and draining of synovia-like fluid. The values of WBC counts were returned to normal ranges. In contrast, eosinophilia was still observed. Coombs test for patient RBC and serum were negative. Hypoalbuminemia (2.5g/dl) was shown by serum chemistry. The uri- nalysis revealed and presence of leukocytes. Luxation finding of right radial carpal joint by polyarthritis was shown in radiography of affected joints.Lupus eryhematosus(LE) cells also appeared in peripheral blood and synovial fluid of affected joints. Definitely, antinuclear antibody (ANA) of patient serum using feline peripheral blood mononuclear cells was detected by all immu- nofluorescence. Based on these findings such as sedum ANA-Positive. major signs (skin disease, non- erosive polyarthritis with soft tissue swelling. and proteinuria), minor signs (fever), and LE cell-pos- itive, a diagnosis of systemic lupus crythematosus (SLE) was mad\ulcorner in this dog. The dog with SLE was administered with Pre(2.0 mg/kg PO, BID for first 4 week and then QOD) to inhibit the production of autoantibodies and with ampicillin (10 mg/kg PO, BID for first 4 weeks and then QOD) to prevent the secondary infection. The condition of this dog was monitored every 2 weeks by physical examinations, radiography, CBC, serum chemistry and urinalyais. At 8th week of treat- ment, the state of SLE evaluated by physical examinations and laboratory findings was markedly improved except for proteinura.

• Journal of Veterinary Clinics
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• v.29 no.5
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• pp.391-394
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• 2012

The purpose of the present study was to prove our empirical tendency of relatively high small intestinal diameter (SI) to fifth lumbar vertebral height (L5) ratio, which has been used in dogs. In this study, the ratio of SI/L5 was determined in small breed dogs weighing less than 5 kg. In addition, the effect of large volume of contrast media on the intestinal dilation was determined by performing upper gastrointestinal contrast study. Abdominal radiography and upper gastrointestinal series were performed in twelve healthy dogs weighing less than 5 kg. Small intestinal diameter (SI), fifth lumbar vertebral height (L5), and twelveth rib diameter were measured on abdominal radiographs. The range of values of SI/L5 is from 1.03 to 2.26 in plain radiography, and from 1.55 to 2.5 in contrast studies. Contrast agent significantly increased small intestinal diameter, and could be considered as mildly dilated intestinal model. Therefore, a value of 2.1 for SI/L5 is recommended as the upper limit of the normal range suggesting nonobstructive intestinal dilation.