• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.117-123
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• 2003

This paper deals with pressure ripple and noise reduction characteristics for a hydrostatic transmission(HST) consisting of a variable axial piston pump connected in an open loop to a fixed displacement axial piston motor. Pressure ripples in HST is major source of vibration, which can lead to fatigue failure of components and cause noise. In order to reduce the pressure ripple, an annular tube type hydraulic filter proposes to absorb pressure ripples with the high frequencies components to achieve better noise attenuation in HST. The basic principle tube is applied to propagation of pressure wave, reflection, absorption in cross section of discontinuity and resonance in the hydraulic pipeline. It is experimently confirmed that a hydraulic filter is absorbed to be about 30∼40dB of pressure ripple with high frequencies. These results will assist in modeling and design of noise reduction in hydraulic control systems, and here, should provide a means of designing a quieter HST.

• Journal of Korea Water Resources Association
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• v.44 no.5
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• pp.417-427
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• 2011

The open-channel flow with submerged vegetation shows distinct features in two separate regions, namely upper and vegetation layers. In the upper layer, the flow is akin to the open-channel flow, while the flow in the vegetation layer is relatively uniform with suppressed turbulence due to vegetation stems. This paper presents laboratory experiments to investigate the characteristics of turbulent flows and suspended sediment transport in open-channel flows with submerged vegetation. An open-channel facility, 0.5 m wide and 12 m long, was used for laboratory experiments. Various discharges were employed with depth ratios of 2~3, and wooden cylinders were used for vegetation. To make equilibrium suspension, sediment particles of median diameter of 75 ${\mu}M$ were fed until capacity condition. Laser Doppler velocimeter was used to measure instantaneous velocity, and direct sampling with vinyl tube was used to measure the concentration of suspended sediment. Using the sampled data, the mean flow and turbulence structures were provided and characteristics of suspended sediment concentration with Rouse number were presented.

• Journal of Chest Surgery
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• v.7 no.1
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• pp.47-60
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• 1974

During the past 10 years 114 patients with empyema have been treated in hospital of Chonnam University. There were 87 males and 27 females ranging from 20 days to 70 years of age. The etiology was pyogenic pneumonia in 36.7%, tuberculosis in 22.7%, paragonimiasis in 8.8%, post-thoracotomy in 5.4%, post-trauma in 4.4%, lung abscess in 3.5%, malignancy in 3.5%, post-esophageal operation in 1.8%, and sterile in 10.5%. The over-all mortality rate was 2% [3 patients]. The majority of deaths occurred in patients with associated systemic illness [liver cirrhosis in I, and renal tuberculosis in I] and resistant tuberculosis for anti-tuberculosis drugs in one patient. Adequate drainage and obliteration of the pleural space continues to be the most important aspect of treatment and can frequently be achieved by closed chest tube thoracostomy in acute empyema especially in children. The more chronic thick-walled or loculated cavities require open drainage [open window therapy], decortication, thoracoplasty, sterilization, and myoplasty for closure of tracheobronchial fistula.

• 한국가스학회:학술대회논문집
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• 1998.09a
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• pp.193-198
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• 1998

• Journal of Chest Surgery
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• v.28 no.5
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• pp.504-506
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• 1995

Postpneumonectomy empyema is an infrequent but dreaded complication. The seriousness of this complication is impossible to eliminate the space containing the infection, and consequently, it is difficult to sterilize the space. The time from pneumonectomy to the development of an empyema ranges from several days to several years, with most evident with 4 weeks. We experienced a case of postpneumonectomy empyema that occurred 27 1/2 years after initial pneumonectomy. She was treated with intrapleural antiseptic irrigation and open-tube drainage following partial decortication. The patient had an uneventful recovery and was discharged from hospital with improved condition.

• 대한생식의학회:학술대회논문집
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• 2004.06a
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• pp.60.1-60.1
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• 2004

• Journal of Korean Clinical Nursing Research
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• v.18 no.1
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• pp.13-28
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• 2012

Purpose: This study was conducted to develop standards ensuring nursing process-based fluid intake/output and tube care, and to develop a performance measurement tool evaluating the level of care according to the standards, and finally to determine validity of the standards and the tool. Methods: The standards and the tool were reviewed by a panel of experts and refined based on the panel's suggestions. Validity of the standards and the tool were examined using a survey of 293 hospital nurses. Results: The mean validity scores of the performance measurement standards and the tool were 3.86 and 4.02, respectively, out of 5.00. So the performance measurement standards and the tool in this study were found to be acceptable in evaluating quality of nursing care for fluid intake/output and tubes. Conclusion: This result indicates that the performance measurement standards and the tool developed in this study are valid instruments to monitor and improve quality of nursing care for fluid intake/output and tube interventions, such as intravenous catheters, nasogastric tube and urinary catheters.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.1
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• pp.17-24
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• 2003

In this paper, a high efficiency leakage transformer for neon tube is developed to improve its power factor, to reduce its core loss and weight by using a technique of shape optimization and grain direction of non-oriented silicon steel strip. A protection circuit is designed for all types of neon transformer loaded with one or more neon tubes. Whenever the neon tube fails to be started up or comes to the life end, or encounters faults with open-circuits at the output terminals of the neon transformer, the electronic type protection circuit will be initiated to avoid more critical hazards. These neon transformers need a electronic type protection circuit to prevent from current stresses on circuit components by neon tube fail. The input of the transformer is automatically cut on when the abnormal condition occurs, preventing waste of no-load power.

• Entomological Research
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• v.48 no.5
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• pp.354-361
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• 2018

Plant essential oils (EOs) exhibit an array of biological activities against insect pests. However, their negative influences on the pheromonal activity of azuki bean beetle (ABB), Callosobruchus chinensis L. have not received research attentions. ABB is a field-to-storage pest of legumes, and its female produces the sex pheromone known as homofarnesal with two isomeric components: 2E- and 2Z-homofarnesal, (2E,6E)-7-ethyl-3,11-dimethyl-2,6,10-dodecatrienals and (2Z,6E)-7-ethyl-3,11-dimethyl-2,6,10-dodecatrienals. We evaluated the effects of three EOs and their two major components on the attractiveness of male ABBs to synthetic homofarnesal (2E-:2Z-homofarnesal = 6:4) using Y-tube olfactometry in laboratory and rocket traps in the semi-open polyhouse. Y-tube olfactometry showed the significant negative effect of EOs of Illicium verum, Croton anisatum at 10 and 100 ng, and Gaultheria fragrantissima at 100 ng against homofarnesal (100 ng) in attracting male ABBs. Similarly trans-anethole (at 10 and 100 ng) and methyl salicylate (at 100 ng) also ascertained significant negative effect against homofarnesal (100 ng) in Y-tube olfactometry. When 10 mg of each of trans-anethole and methyl salicylate was released at the downstream of 30 mg homofarnesal lure in rocket traps, highly significant effect was achieved against attractiveness of homofarnesal to ABB males. This study ascertained significant level of negative effect of the tested EOs and their major components to homofarnesal, tracing out a new opportunity of integrating them in ABB management programs both in field and storage.

• Steel and Composite Structures
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• v.44 no.3
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• pp.309-324
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• 2022

The post-fire elastic stiffness and performance of concrete-filled steel tube (CFST) columns containing recycled aggregate concrete (RAC) has rarely been addressed, particularly in terms of material properties. This study was conducted with the aim of assessing the modulus of elasticity of recycled aggregate concrete-filled steel tube (RACFST) stub columns following thermal loading. The test data were employed to model and assess the elastic modulus of circular RACFST stub columns subjected to axial loading after exposure to elevated temperatures. The length/diameter ratio of the specimens was less than three to prevent the sensitivity of overall buckling for the stub columns. The gene expression programming (GEP) method was employed for the model development. The GEP model was derived based on a comprehensive experimental database of heated and non-heated RACFST stub columns that have been properly gathered from the open literature. In this study, by using specifications of 149 specimens, the variables were the steel section ratio, applied temperature, yielding strength of steel, compressive strength of plain concrete, and elastic modulus of steel tube and concrete core (RAC). Moreover, parametric and sensitivity analyses were also performed to determine the contribution of different effective parameters to the post-fire elastic modulus. Additionally, comparisons and verification of the effectiveness of the proposed model were made between the values obtained from the GEP model and the formulas proposed by different researchers. Through the analyses and comparisons of the developed model against formulas available in the literature, the acceptable accuracy of the model for predicting the post-fire modulus of elasticity of circular RACFST stub columns was seen.