• Journal of Veterinary Clinics
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• v.24 no.2
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• pp.233-237
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• 2007

A 10-month-old intact male Labrador Retriever dog was referred with the primary complaint of exercise intolerance, especially after vigorous exercise. Physical examination revealed split S1 and grade III/VI diastolic regurgitant murmur at the left apex and base, respectively. ECG finding was normal sinus rhythm at rest, but supraventricular tachycardia with bundle branch blocks after exercise. Thoracic radiography revealed dilated ascending aorta with normal range of cardiac silhouette (VHS 10.2). Echocardiography revealed abnormal valvular structures just above the aortic valvular cusps causing aortic regurgitation with a reduction of left ventricular ejection fraction (LVEF). Based on those findings, the case was diagnosed as congenital aortic regurgitation caused by abnormal valvular structures. The dog was managed with diltiazem and exercise restriction. This is a rare case of aortic deformity in dogs.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.4
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• pp.348-353
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• 2004

This study is aimed for the implementation of ultrasonic method to assess the reliability of turbine bearings. A modified ultrasonic immersion technique was carried out in both laboratory experiment and field application. From the laboratory results, we confirmed that the condition of interface layer between the babbitt and base metal be monitored by the C-Scan. The C-scan image by the ultrasonic immersion test can be used successfully to observe the condition of interface layer. The testing with a focused transducer provides a promising approach for estimating the extent of the damaged region and observing the interface layer effectively. The difference of the ultrasonic reflection ratio between the bonding and debonding area at the interface layer is one of the key parameters for assessing the extent of the damaged area; additionally, the reflection amplitude exhibits a favorable correlation with the overall damage level. The technique developed in this study was applied to the inspection of the turbine bearings at several power plants in Korea whereby the applicability in the field can be ascertained.

• Korean Journal of Food Science and Technology
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• v.9 no.1
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• pp.61-67
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• 1977

Seed separation from half-cut red pepper were investigated with free falling, up-and-down shaking and rotating collision methods. The separation rates were related with impact appiied and the rotating case was distinguished from the other two methods. Beside the impact effect, velocity of the pod and tumbling factors were involved. Momentum effectiveness of seed separation were calculated as $2.50{\times}10^{-6}$, $2.09{\times}10^{-6}$, and $3.94{\times}10^{-8}$ for free falling, shaking and rotating method on the same velocity basis, respectively. The tendency of separation rate was similar to that of red pepper drying rate against time.

• International Area Studies Review
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• v.14 no.2
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• pp.79-105
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• 2010

This paper investigates empirically the impact of foreign investors on a firm's dividend and investment decision making in Korean stock market. Empirical results using the sample firms in non-financial firms listed in Korean stock market whose settlement month are December, we find that foreign investors who declared participation in management didn't exert significant impact on dividend increase. In the case of investment, foreign investors exerts significant impact on R&D investments. Using Hausman-Taylor Instrumental Variable method, we controlled endogeneity problem related with foreign ownership and dividend and investment policy. The contribution of this paper is that the purpose of foreign investors whether or not participate in management is the most critical point and the impacts of foreign investors on dividends and investment are different whether they participate in management or not.

• Journal of the Korea Society of Computer and Information
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• v.28 no.5
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• pp.75-82
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• 2023

In collaborative filtering systems, the item rating prediction values calculated by the systems are very important for customer satisfaction with the recommendation list. In the time-aware system, predictions are calculated by reflecting the rating time of users, and in general, exponentially lower weights are assigned to past rating values. In this study, to find out whether the influence of rating time on the rating value varies according to various factors, the correlation between user rating value and rating time is investigated by the degree of user rating activity, the popularity of items, and item genres. As a result, using two types of public datasets, especially in the sparse dataset, significantly different correlation index values were obtained for each factor. Therefore, it is confirmed that the influence weight of the rating time on the rating prediction value should be set differently in consideration of the above-mentioned various factors as well as the density of the dataset.

• Applied Chemistry for Engineering
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• v.34 no.5
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• pp.493-500
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• 2023

In this study, we developed an impedance sensor capable of controlling electrode polarization by coating iridium oxide (IrO_x) on the surface of the screen-printed carbon electrode. IrO_x was deposited on the surface of carbon electrodes according to the number of cycles (0~50 cycles) by cyclic voltammetry. Observation of scanning electron microscope images revealed that the size and number of IrO_x particles increased as the number of cycles increased. The changes in impedance responses as a function of the NaCl concentration of the as-obtained sensors were investigated using electrochemical impedance spectroscopy. The sensors manufactured in 50 cycles exhibited the best coefficient of determination and reproducibility, attributed to the well-controlled electrode polarization. We further demonstrated the usefulness of the IrO_x-based sensor as a diagnosis sensor for dry eye syndrome by comparing the results of the commercially available osmometer and our sensor using actual solution samples.

• Radiation Oncology Journal
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• v.11 no.2
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• pp.387-395
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• 1993

To identify pretreatment prognostic factors in carcinoma of the uterine cervix, a retrospective analysis was undertaken of 510 patients treated with curative radiation therapy in Seoul National University Hospital during the 7 year period, from March 1979 through December 1986. According to FIGO classification,35 patients were stage I B,89 were stage IIA, 232 were stage IIB,8 were stage IIIA, 134 were IIIB, and 12 were stage IVA. Five year locoregional control (LRC) rates in stage I B, II A, II B, IIIA, IIIB, and IVA were $79\%,78\%,70\%,58\%,51\%\;and\;27\%,$ respectively. Five year disease free survival (DFS) rates were $76\%,67\%,60\$,57\%,40\%,\;and\;25\%,$ respectively. Overall survival (OS) rates at five years were $82\%,72\%,67\%,67\%,51\%,\;and\;33\%,$ respectively. In univariate analyses, stage, age, initial hemoglobin level, type of histology, tumor size, and several CT findings including pelvic lymph node (LN) status, paraaortic lymph node (PAN) status, extent of parametrial invasion, bladder invasion, and rectal invasion were significant factors in terms of LRC. All these factors and elevation of BUN or creatinine were associated with DFS. In terms of overall survival, stage, initial hemoglobin level, type of histology, tumor size, elevation of BUN or creatinine, and five CT findings associated with LRC were prognostically significant. In multivariate analysis excluding CT findings, stage IV disease, non-squamous histology, and tumor size $\ge$4 cm were associated with poor LRC and DFS. Stage IV disease and tumor size significantly affected OS. in multivariate analysis including CT findings, histology, tumor size, and pelvic LN status on CT were uniformly significant in terms of LRC, DFS, and 05, PAN status on CT affected overall survival only.

• The Journal of the Petrological Society of Korea
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• v.24 no.3
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• pp.165-180
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• 2015

Jurassic granite from Geochang was analysed with respect to the characteristics of the rock cleavage. The phases of distribution of microcracks were well evidenced from the enlarged photomicrographs(${\times}6.7$) of the thin section. In this study, the length - cumulative frequency diagrams were used for expressing the distribution characteristics of microcrack. The diagrams for the six directions were arranged in the magnitude of density(${\rho}$). These diagrams show an order of H2 < H1 < G2 < G1 < R2 < R1 from the related chart. Among six diagrams, the diagram for hardway 2(H2) occupies the lowermost region on the left. On the contrary, the diagram for rift 1(R1) occupies the uppermost region on the right. Curve patterns of the two diagrams change from uniform to exponential distribution type in accordance with the increased density. The overall distribution characteristics of the diagrams were well evidenced from the magnitude of the exponent(${\lambda}$) and length of line oa related to the exponential straight line. The magnitude of exponent governing the values of slope(${\theta}$) is inversely proportional to the values of microcrack parameters such as number(N), length(L) and density. On the contrary, length of line oa is directly proportional to the values of the above three parameters. Above microcrack parameters related to the order of arrangement of diagrams show an order of hardway(H1 + H2) < grain(G1 + G2) < rift(R1 + R2). The distribution characteristics of progressive variation are found among the six diagrams. The order of arrangement of the diagrams indicates a relative magnitude of the rock cleavage. Meanwhile, the parameters such as slope, exponent, density and length of line oa were arranged in an order of H2 < H1 < G2 < G1 < R2 < R1. The variation curves of a smooth quadratic function are shown from the related chart. From the correlation chart between density and the above parameters, a common regularity following power-law correlation function was derived. Finally, the analysis for the rock cleavage was conducted through the combination between the diagram and microcrack parameter. This type of combination contribute to the progressivity in evaluation for the rock cleavage.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1981.05a
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• pp.9.1-10
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• 1981

The clinical study of 183 cases of laryngeal mass was observed and 88 cases of vocal nodule and polyp which is confirmed histopathologically, were clinically classified into 30 cases of vocal nodule, 48 cases of localized vocal polyp, 10 cases of diffuse vocal polyp, and the following results of microscopic examination were obtained. I. The clinical study of laryngeal mass 1. Among total cases of 183, vocal nodule is 82(45%) vocal polyp 53(29%) postintubation granuloma 3(1%) laryngeal papilloma 18(10%) tuberculosis 2(1%) cancer 25(14%). 2. The sex ratio of male to female is 3:4 in vocal nodule, 1:1 in vocal polyp, 1:2 in postintubation granuloma, 3:2 in laryngeal papilloma, 11:1 in cancer. 3. The age distribution is third-fourth decade in vocal nodule, fourth-fifth decade in vocal polyp, third decade in postintubation granuloma, second and fifth decade in laryngeal tuberculosis, sixth decade in laryngeal cancer. 4. The distribution of symptoms is 5 month. -1 year in vocal nodule and polyp, less than 1 year in laryngeal papilloma and postintubation granuloma, 1 year-3 year in laryngeal tuberculosis and cancer. 5. The location of the lesion is between the anterior 1/3 and middle 1/3 in vocal nodule and polyp and papilloma, middle 1/3 and posterior 1/3 in postintubation granuloma, and is diffusely spread on the entire vocal cord in laryngeal tuberculosis and cancer. 6. The side of the lesion is bilateral in vocal nodule and papilloma and the ratio of right to left is 5:3 in vocal polyp, 2:1 in postintubation granuloma. 7. The size is 1~2mm(67%) in vocal nodule, 3~5mm(42%) in vocal polyp, 6~10mm (67%) in postintubation granuloma, 1~2mm (39%) in papilloma, more than 10mm in tuberculosis and cancer. 8. Among the symptoms, the hoarseness is in more than 90% of disease entity, the sore-throat in tuberculosis and cancer, the dyspnea in postintubation granuloma and papilloma and tuberculosis and cancer. 9. In the past history, certain relationship with smoking is noted in cancer (40%) and tuberculosis(50%) and the history of frequent attack of URI is in papilloma(33%). 10. In occupation, certain statistical significance was not noted. II. The histopathological study of vocal nodule and polyp. 1. Most polyps and nodules were covered with stratified squamous epithelium, but focal hyperkeratosis, parakeratosis, acanthosis and atrophy were rather frequently observed. Hyperkeratosis and acanthosis was most frequently seen.

• Journal of the Korean Chemical Society
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• v.24 no.5
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• pp.380-392
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• 1980

Six coordinate low spin iron(Ⅱ) complexes of vicinal-dioximes, [Fe$(DH)_2B_2$] and [Fe$(DH)_2$B(CO)]($(DH)_2$=$(CHDH)_2$(bis(1,2-cyclohexadinedioximato) bivalent anion), $(DPGH)_2$-(bis(diphenylglyoximato) bivalent anion), $(F{\alpha}DH)_2(bis(furil-{\alpha}-dioximato)$ bivalent anion); B = monodentate neutral nitrogen base), have been prepared and their physical properties have been investigated with respect to the effects of the equatorial ligands, $(DH)_2$. The order of ${\pi}$-acceptor CO stretching frequency for [Fe$(DH)_2$B(CO)] is $(F{\alpha}DH)_2$ > $(DPGH)_2$> $(CHDH)_2$, while non-${\pi}$-acceptor $NH_3$ stretching frequencies for [Fe$(DH)_2(NH_3)_2$] show the opposite order to that of CO, i.e., $(CHDH)_2$ > $(DPGH)_2$ > $(F{\alpha}DH)_2$. These infrared spectral data together with Fe-N (oxime) and Fe-N (oxime) and Fe-N (B) stretching frequency data suggest that the nitrogen atoms of $(CHDH)_2$ are more basic and poorer ${\pi}$-acceptors than the corresponding nitrogen atoms of $(DPGH)_2$ and $(F{\alpha}DH)_2$, respectively. It has been found from the electronic spectral data of [Fe$(DH)_2$] and [Fe$(DH)_2$B(CO)] that the energy of the charge transfer band from iron(Ⅱ) to $(DH)_2$ increases as the basicity of $(DH)_2$ increases.