• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.9
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• pp.667-674
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• 2014

A ship's propulsion shafting system is subjected to varying magnitudes of intermittent loadings that pose great risks such as failure. Consequently, the dynamic characteristic of a propulsion shafting system must be designed to withstand the resonance that occurs during operation. This resonance results from hydrodynamic interaction between the propeller and fluid. For ice-class vessels, this interaction takes place between the propeller and ice. Producing load- and resonance-induced stresses, the propeller-ice interaction is the primary source of excitation, making it a major focus in the design requirements of propulsion shafting systems. This paper examines the transient torsional vibration response of the propulsion shafting system of an ice-class research vessel. The propulsion train is composed of an electric motor, flexible coupling, spherical gears, and a propeller configuration. In this paper, the theoretical analysis of transient torsional vibration and propeller-ice interaction loading is first discussed, followed by an explanation of the actual transient torsional vibration measurements. Measurement data for the analysis were compared with an applied estimation factor for the propulsion shafting design torque limit, and they were evaluated using an existing international standard. Addressing the transient torsional vibration of a propulsion shafting system with an electric motor, this paper also illustrates the influence of flexible coupling stiffness design on resulting resonance. Lastly, the paper concludes with a proposal to further study the existence of negative torque on a gear train and its overall effect on propulsion shafting systems.

• Korean Journal of Environmental Agriculture
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• v.11 no.1
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• pp.41-49
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• 1992

To determine the efficacy of uniconzaole[(E)-1-(4-chlorophenyl)-4,4-dimethy 2-(1,2,4-triazol-1-yl)-1-penten-3-ol)](XE-1019) as a phytoprotectant against $O_3$ injury in tomato plants(Lycopersicon esculentum Mill. 'Pink Glory'), plants were given a 50ml soil drench of uniconazole solution at concentrations of 0.001, 0,01, 0.1 and 0.2mg/pot thirteen days prior to $O_3$ fumigation. All four uniconazole concentrations were effective in providing protection against $O_3$ exposure(16h at 0.3 ppm). Uniconazole treatment above 0.001 mg/pot significantly reduced stem elongation, leaf enlargement, leaf area and fresh weight of plant, whereas increased chlorophyll concentration. Transpiration rate on a whole plant basis was reduced by uniconazole treatment and $O_3$ exposure. Uniconazole reduced ethylene production induced by $O_3$ injury but had little or no effect on defoliation of cotyledons and leaf epinasty. Activities of peroxidase (POD) and superoxide dismutase(SOD) were slightly increased by application of uniconazole. With increasing exposure time, $O_3$ increased POD activity but decreased SOD activity. The phytoprotective effects of uniconazole were diminished by applying gibberellin at $10{\sim}20$ ppm. These results suggest that the phytoprotective effects of uniconazole are related to its role of increasing activities of free radical scavengers such as POD and SOD, in addition to growth-retardation as an anti-gibberellin.

• The Journal of the Korea Contents Association
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• v.18 no.2
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• pp.216-230
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• 2018

In this paper, we analyze the economic ripple effects of technology related to the unmanned aerial vehicle industry by applying industry association analysis. Specifically, the effects of employment creation, value added inducement, sensitivity coefficient, and influence coefficient can be calculated, and implications for the analysis result are presented. As a result, the employment inducement effect was confirmed to be 10.017 persons per 1 billion won of investment. The value added inducement effect was much higher than the other manufacturing industry average (employment inducement coefficient: 2.285, value added inducement coefficient: 0.581) when the 1 won budget was added, resulting in 0.9771 won added value. In the unmanned aerial vehicle industry, the coefficient of sensitivity, which means the front chain effect, is 0.7870, which is lower than the manufacturing average (sensitivity coefficient 1.125), and the coefficient of influence, which means the backward chain effect, is 1.161, which is higher than the manufacturing average (influence coefficient: 1.116). Therefore, it is classified as the final demand manufacturing industry. This means that the unmanned aerial vehicle industry is an industry that is less affected by economic fluctuations and can be interpreted as an industry with a greater economic impact than other sectors. Based on these data, it can be used to establish the R&D investment direction policy of the unmanned aerospace industry.

• Journal of Animal Science and Technology
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• v.44 no.5
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• pp.617-624
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• 2002

Annual legume is being used as an important source of protein for farm animals and an ingredient for nitrogen fertilizers. There are, however, difficulties in selecting appropriate cultivar and forage management technique. The objective of this study is to select the best performing cultivars and evaluate a forage value on annual legume at two locations (Suwon and Sunghwan) for 1 year (1999${\sim}$2000). All cultivars shown a seedling vigor and lodging resistance of 8 rating or higher. Crimson and rose clover showed that they are appropriate for overwintering, but ;Laser; (35.9%) and 'Nitro'(9.1%) of persian clover variety did not overwinter well from 1999 to 2000. Flower stage was observed 4th of May for 'Tibbee', 6th of May for 'Contea' crimson clover, and 29th of April for 'Bolta balansa' rose clover. DM yield of a crimson clover 'Contea' (4,218kg/ha) was the highest among the legume forage. A crimson clover 'Tibbee' and rose clover 'Bolta balansa' also had a high production yield (3,874 and 3,828kg/ha). Calculations of relative feed value (RFV) based on the acid and neutral detergent fiber (ADF and NDF) of annual legume were over 125, which means that quality was high. According to the results of this study, crimson and rose clovers are recommended due to their high winter survival rate and high DM yield. Persian clover is not recommended because of a low overwintering rate at the Central region in Korea.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.188-192
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• 2007

Today, the most pivotal issue in the national research and development, and national scientific and technical policy is to overcome uncertainties in the environment of technology development. The social and economic environment around us is at restricted uncertainty (complex system) where order and disorder coexist. Furthermore, the environment of technology development is more complicated. In order to bring about creativity in practices of technology development, we need a paradigm shift towards a new framework for the construction of the national scientific and technical information infrastructure, which entails a shift to creativity, self-organization and dynamic capability. The paradigm shift will lead the present scientific and technical information infrastructure which centers on information sharing, to move towards one that enables information coherence through self-organization. Thus, it is expected that the new Web 3.0 will provide a client-flexible analysis information system that will make information coherence and feedback possible. Through this system, the policy for the construction of a new scientific and technical infrastructure will evolve, which will bring about co-evolution of individual's knowledge through sharing of self-organizaed knowhow.

• The KIPS Transactions:PartC
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• v.12C no.7 s.103
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• pp.989-998
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• 2005

Information systems are today becoming larger and mostly broadband-networked. This exposes them at a higher risk of intrusions and hacking than ever before. Of the technologies developed to meet information system security needs, risk analysis is currently one of the most actively researched areas. Meanwhile, due to the extreme diversity of assets and complexity of network structure, there is a limit to the level of accuracy which can be achieved by an analysis tool in the assessment of risk run by an information system. Also, the results of a risk assessment are most oftennot up-to-date due to the changing nature of security threats. By the time an evaluation and associated set of solutions are ready, the nature and level of vulnerabilities and threats have evolved and increased, making them obsolete. Accordingly, what is needed is a risk analysis tool capable of assessing threats and propagation of damage, at the same time as security solutions are being identified. To do that, the information system must be simplified, and intrusion data must be diagrammed using a modeling technique this paper, we propose a modeling technique information systems to enable security risk analysis, using SPICE and Petri-net, and conduct simulations of risk analysis on a number of case studies.

• Tuberculosis and Respiratory Diseases
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• v.46 no.2
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• pp.266-272
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• 1999

Coccidioidomycosis is a fungal infection acquired by inhalation of the arthrospore of Coccidioides immitis, and endemic disease in specific geographic areas, such as south central California, south Arizona. Nevada, and New Mexico. Approximately 60 percent of infected people is asymptomatic and the remainders mostly exhibit respiratory complaints, from flu-like coughing to overt pneumonia. Usually the infection due to Coccidioides immitis is self-limited. Symptoms resolve within several weeks but radiographic abnormalities could be resolved more slowly. If the radiographic abnormalities persist more than 8 weeks, the term' chronic pulmonary coccidioidomycosis' is designated. They take forms of nodules, cavities or progressive pneumonia. When manifested as nodule(s), lung malignancy is suspected as a possible diagnosis and histologic confirmation is needed. Here, we report a case of chronic pulmonary coccidioidomycosis manifested as solitary pulmonary nodule in a Korean woman who has traveled in Arizona, which is diagnosed finally by lobectomy and histologic examination.

• Tuberculosis and Respiratory Diseases
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• v.51 no.4
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• pp.379-385
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• 2001

Sternocostoclavicular hyperostosis is an uncommon disease, characterized by an inflammatory arthrosteitis of the sternocostoclavicular region. Clinically, it manifests as a painful swelling of the upper anterior chest wall, which is associated with occasional pustulosis palmaris and plantaris. A 48-year-old man had suffered from pain in both shoulders and the upper anterior part of the chest for 6 months. On examination, a venous engorgement in the neck with dilated collateral veins in the upper chest and shoulders was observed. Swelling was noticed in his face, neck and both arms. Radiologically, the clavicles, the sternum and the first ribs were enlarged with complete fusion between them. 99Tc scintigraphy showed increased uptake in the clavicles and the sternum. Selective venography resulted in a bilateral subclavian and brachiocephalic vein occlusion, which resulted from a subclavian vein thrombosis. All the above suggested a sternocostoclavicular hyperostosis. He underwent a vascular graft interposition between the right jugular vein and the left innomianate vein (using 8mm ringed Gore-Tex graft) and a resection of the bilateral medial half of clavicle and 1st rib. Here, we present a case on sternoclavicular hyperostosis with subclavian and brachiocephalic vein thrombosis, and report this case study with a review of the appropriate literature.

• Tuberculosis and Respiratory Diseases
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• v.49 no.1
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• pp.99-104
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• 2000

Pulmonary hemangiomatosis is a rare disease of unknown etiology characterized by diffuse proliferating microvessels that infiltrate not only the lung but also all of the thoracic tissues. The disease is rapidly progressive and usually results in death due to complications of pulmonary hypertension and pulmonary hemorrhage. There are two histologic patterns of pulmonary hemangiomatosis : capillary and cavernous. We describe a 21-year-old man with cavernous-type pulmonary hemangiomatosis presented with right side shoulder pain. He was treated with percutaneous transarterial embolization and then followed with interferon alfa-2a for one year with favorable clinical and radiological response.

• The Korean Journal of Nuclear Medicine
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• v.10 no.1
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• pp.35-46
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• 1976

To evaluate the possible pathophysiologic role of renin in acute renal failure observed in Korean hemorrhagic fever (KHF), the author measured the basal plasma renin activity (PRA) and the stimulated PRA by radioimmunoassay for angiotensin I in 15 normal controls and 42 KHF patients who are admitted in Seoul National University Hospital and Nation Army Hospital from Jan. 1975 to Jan. 1976. The results obtained were as follows: The mean basal PRA in normal control group was $2.9{\pm}2.16ng/ml/hr$ in the patients during the oliguric phase of KHF, the mean basal PRA was $4.7{\pm}2.13ng/ml/hr$, and there was statistically significant increase compared to the normal control. In the patients during the diuretic phase of KHF, the mean basal PRA was $3.4{\pm}2.09ng/ml/hr$, and there was statistically significant decrease compared to the oliguric phase of KHF. In normal control group, the mean basal PRA was $2.9{\pm}2.16ng/ml/hr$. And the PRA 1 hour after the administration of $Lasix^{(R)}$ 40 mg intravenously(stmulated PRA) was $5.3{\pm}2.20ng/ml/hr$ and there was statistically significant increasec ompared to basal level. In oliguric phase of KHF, the mean basal PRA was $4.6{\pm}2.01ng/ml/hr$. And stimulated PRA was $4.4{\pm}2.34ng/ml/hr$ and there was no significant changes. In diuretic phase of KHF, the mean basal PRA was $3.3{\pm}1.86ng/ml/hr$. And stimulated PRA was 5.2{\pm}2.58ng/ml/hr and there was statistically significant increase compared to basal level. There were statistically no significant correlations between basal PRA and stimulated PRA and serum creatinine, BUN, urine volume and peritonial dialysis.