• Korean Journal of Plant Taxonomy
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• v.47 no.1
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• pp.27-45
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• 2017

A taxonomic study of the genus Hosta (Lilliaceae) in Korea was conducted based on morphological characteristics. Hosta clausa varieties share several characteristics (rhizomes with underground stolons, smooth scapes, and purple anthers). Hosta clausa var. normalis has an open perianth, long pistils, and fertile fruit. H. clausa var. clausa can be distinguished from H. clausa var. normalis by its closed perianth and sterile fruit. H. clausa var. geumgangensis has sterile fruit, green petioles, short pistils, and short narrow perianth tubes. H. clausa var. ensata has very narrow, sword-shaped leaves. It can be included in H. clausa var. normalis, which has a large degree of variation in leaf and petiole shape. H. jonesii has smooth scapes, yellow anthers, and bell-shaped flowers. It can be distinguished from the related species H. tsushimensis found on the Tushima islands in Japan by its wide perianth tube. H. yingeri is distinguished by its funnel-shaped flowers, 3 long and 3 short stamens, and smooth scape; the related species H. laevigata has 6 equally-sized stamens, narrowly lanceolate leaves, and wavy leaf margins. Because H. laevigata is not found in its type locality Isl. Heugsando, its taxonomic position must be determined at a later time. H. minor shares several characteristics (scapes with ridges and yellow-colored anthers) with the related taxa H. venusta. However, H. venusta is changed to H. minor var. venusta because it has overlapping characteristics in plant size, number of flowers, leaf size, and leaf shape. Consequently, the genus Hosta in Korea is classified into 5 species, 3 varieties, and 6 forms.

• Journal of the Korean Society of Radiology
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• v.13 no.3
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• pp.481-487
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• 2019

Based on the scan conditions and algorithms that are generally applied during examinations during head CT examinations, the results of dose reduction through the application of algorithm changes were investigated through experiments. As a result, the dose reduction effect was more meaningful for the change of perfusion than for the tube voltage, and the quality evaluation using the brain phantom was relatively less reduced when the dose was reduced after the application of the Bone algorithm, especially for the application of the Bone algorithm, and the deviation of the mean CT number or Pixel value was measured relatively significantly. In other words, the conditions under which dose was reduced and quality was maintained to reduce the patient's exposure dose and obtain images of the same quality were obtained with the application of the Smooth algorithm and the resulting values of 120 kVp, 160 mA. At this point, doses were reduced by about 28%, and the mean CT number or Pixel value was also measured with relatively little error. If the results are applied to patients who visit the hospital for examination or follow-up after applying various algorithms and follow up scan conditions, the results are considered to be very useful in reducing patient exposure dose.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.1
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• pp.54-61
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• 2001

Condensing heat transfer coefficients of R-22 and R-134a were measured in smooth, horizontal copper tubes with inner diameters of 1.77mm, 3.36mm, and 5.35mm, respectively. The experiments were conducted in the closed loop, which was driven by a magnetic gear pump. Data are presented for the following range of variables : mass velocity from 200 to 500kg/$m^2$.s and quality from 0 to 1.0. The heat transfer coefficients in the small diameter tubes (ID < 7mm) were observed to be strongly affected by various diameters and the heat transfer characteristics in the small diameter tubes differed from those in the large diameter tubes. Heat transfer coefficients in the small diameter tubes are higher than those in the large diameter tubes at the same experimental condition. It was found that some well-known previous correlations(Shahs correlation and Cavallini-Zecchins correlation) were not suitable for small diameter tubes.

• Journal of Chest Surgery
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• v.27 no.4
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• pp.292-296
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• 1994

From March, 1985, to June, 1993, 244 patients with 345 episodes of spontaneous pneumothorax treated at Koryo General Hospital were reviewed. Most of the patients were male, and the ratio of male to female was 8:1. The average age of the patients with spontaneous pneumothorax was 32.8 years old. The site of pneumothorax was revealed left side in 53.3%, right side in 42.6%, and bilateral in 4.1%. The cause of pneumothorax were shown primary spontaneous pneumothorax in 73.4%, and secondary spontaneous pneumothorax in 26.6%. The underlying pathologic lesion in secondary spontaneous pneumothorax showed pulmonary tuberculosis in 56patients[86.1%], COPD in 4patients[6.2%], bronchial asthma in 2patients[3.1%], lung cancer in 2patients[3.1%], and pneumoconiosis in a patient[1.5%]. The usual clinical symptomes were dyspnea, chest pain and chest discomfort. Recurrence rate was as follow; 2nd episode 33.6%, 3rd episode in 26.8%, and above in 4th episode in 18.2%. All the patient of pneumothorax was treated as following; Closed thoracostomy tube drainage in 127patients, bullectomy in 88patients, lobectomy in 5patients, wedge resection in 2patients, conservative treatment with oxygen therapy in 21patients, and video assisted thoracoscopic bullectomy in a patient. The course of treatment of all of the patients were smooth and uneventful.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.2
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• pp.122-128
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• 2014

The present study was performed to examine the contraction and relaxation responses of the smooth muscles, and search for antimicrobial and antioxidant activities in the tissues, of the starfish Asterina pectinifera. Frozen samples were extracted with distilled water containing 1% acetic acid. Extracts from all tissues showed potent antimicrobial activity against Escherichia coli D31. Relatively high levels of antimicrobial activity were also detected in the body extracts. Liver, tube feet, and body extracts caused contraction responses in the dorsal retractor muscles (DRM) of the starfish. In contrast, all tissues examined exhibited contractile activity in the esophagus of squid Todarodes pacificus. In addition, liver and gonad extracts caused contraction responses upon application to the intestine of the puffer fish Takifugu pardalis. Relaxation effects on the DRM of starfish were identified in most of the extracts, while no relaxant activity was detected in body extracts. Extracts from all tissues examined also exhibited antioxidant activities. The results of this study suggest that starfish are a potential source of novel bioactive compounds.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.373-378
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• 2000

An experimental investigation on the incipience of nucleate boiling in forced flow of water is performed as a verification and extension of previous analysis. The effects of the subcooling, Reynolds number and surface curvature on the onset of nucleate boiling(ONB) in a concentric annulus flow channel with smooth inner heating surface is investigated experimentaly. Through flow visualization, the boiling phenomenon was observed directly and the experimental results were examined to find ONB heat flux. The results show that the variation of heat flux at ONB is increased linearly as the Reynolds number and subcooling are increased. The effect of surface curvature is very great specially for a small radius when radius of the inner heating tube is increased, the heat flux at ONB is almost inversely increased for the range of this investigation. It is found that the effect of convex surface curvature on ONB heat flux is very significant for a small radius.

• Journal of Welding and Joining
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• v.17 no.4
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• pp.26-31
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• 1999

An attempt was made in this study to investigate the brazing characteristics of Zr-Be binary amorphous alloys for the development of a new brazing filler metal for joining Zircaloy-4 nuclear fuel cladding tubes. This study was also aimed at the feasibility study of rapidly solidified amorphous alloys to substitute the conventional physical vapor-deposited(PVD) metallic beryllium. The $Zr_{1-x}Be_{x}$($0.3\leq$x$\leq0.5$) binary amorphous alloys were produced in the ribbon form by the melt-spinning method. It was confirmed by x-ray diffraction that the ribbons were amorphous. The amorphous. the amorphous alloys were used to join bearing pads on Zircaloy-4 nuclear fuel cladding tubes. Using Zr-Be amorphous alloys as filler metals, it was found that the reduction in the tube wall thickness caused by erosion was prevented. Especially, in the case of using $Zr_{0.65}Be_{0.35}$ and $Zr_{0.7}Be_{0.3}$ amorphousalloys, the smooth and spherical primary $\alpha$-Zr particles appeared in the brazed layer, which was the most desirable microstructure from the corrosion-resistance standpoint.

• Tuberculosis and Respiratory Diseases
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• v.62 no.1
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• pp.71-73
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• 2007

Bronchogenic cysts are commonly located in the mediastinum or lung parenchyma, and arise from the abnormal budding of the primitive tracheobronchial tube. Cough and pain are the most common symptoms. Bronchogenic cysts appear as spherical or oval masses with smooth outlines and are usually unilocular and noncalcified. We report a young adult with a bronchogenic cyst presenting as multicystic pulmonary parenchymal lesions. This case is very unusual because a multicystic intrapulmonary bronchogenic cyst is very rare in adults.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.317-322
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• 2008

The objectives of this paper are to study the effects of thermal and geometric conditions on the performance of indoor heat exchanger with R410A for Gas Engine Driven Heat Pump (GHP) application and to find optimum design conditions of indoor heat exchanger by parametric analysis for the key parameters. In the air side, moisture out of the humid air condenses on the fin surface while the refrigerant (R410A) boils inside the smooth tube. Therefore this study uses Log Mean Enthalpy Difference (LMHD) method to analyze the heat transfer from the humid air to the refrigerant of R410A. The results show that fin pitch and longitudinal pitch have significant effect on the heat exchanger preformance. This study will provide the guideline for optimum design of indoor heat exchanger with R410A for GHP application.

• Plant Journal
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• v.8 no.2
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• pp.52-58
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• 2012

Pipe means the connection of the tube in order to transfer fluid from one device to another device. The piping stress analysis is to analyze the structural stability considering the location and the features of piping support after completing the piping design, The allowable stresses comply with the requirements of the relevant standards by examining whether the support of the function and location of pipe or re-operation is confirmed. Allowable stresses are to make sure that the maximum stress should not exceed the allowable stress presented in the ASME B31.1 POWER PIPING code. ASME B31.1 POWER PIPING code ensures a smooth stress analysis can be performed during the initial pipe stress analysis as provided in the case of straight pipe to the horizontal distance between the supports. However, because there is no criteria set in the case of curved pipe, the optimum pipe supporting points were studied in this paper. As mentioned about the curved pipe, loads applied to the support of the position of 17% and 83% of the position relative to the elbow part have results similar to the load acting on the support of straight pipe.