• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.10 s.241
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• pp.1119-1129
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• 2005

A new measurement system of wall pressure fluctuations on a rotating machinery, composed of digital recording device, was developed and evaluated. The small-sized digital recording device was attached on the rotating machinery and then was detached for data reduction. In order to obtain the system transfer function of the digital recording system, a dynamic calibration was performed utilizing the signal from a 1/8 inch B&K microphone as input. The time history of the unsteady pressure was then reconstructed from the output of the sensor by using this transfer function. The reconstructed pressure signals showed good agreement with the reference signal in both temporal and spectral sense. This sensor was then used to measure the wall pressure fluctuations on a rotating blade. An array of microphones were installed on the blade in the circumferential and radial directions. Various statistical moments were obtained from the measurement data set. Comparison of these quantities with the existing studies demonstrated satisfactory agreement. These tests give credence to the relevance and reliability of this device for applications in more complicated turbulent rotating machineries.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.10
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• pp.1430-1434
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• 2005

We conducted two experiments to assess the effect of transfer from housing to grazing on stress hormone secretion in cattle using urine samples. In a preliminary experiment, urine samples were collected following an adrenocorticotrophic hormone (ACTH) challenge, and cortisol levels in urine were compared with the levels in plasma. In a second experiment, urinary cortisol was measured before and after the start of a grazing season in 6 Japanese Shorthorn cows, all of which had experienced grazing before. In experiment 1, urinary cortisol showed a pattern of changes similar to that of plasma with a 0.5-h temporal lag time, and the peak levels were 4 to 10 times higher than the basal levels. In experiment 2, the urinary cortisol levels in cows did not change after the cows were let out to pasture, with no decreases in body weight. This study suggests that the transfer from housing to grazing did not affect physiological responses to cause high excretion of urinary cortisol in grazing-experienced cattle using a non-invasive sampling method.

• Proceedings of the KSRS Conference
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• v.1
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• pp.232-235
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• 2006

Using 30 days of hourly visible channel data and DIScrete Ordinate Radiative Transfer (DISORT) model (6S), Aerosol optical depth (AOD) at $0.55{\mu}m$ was retrieved over the East Asia. In contrast with the AOD retrieval using low-earth-orbit satellites such as MODIS (Moderate-Res olution Spectroradiometer) or MISR (Multiangle Imaging SpectroRadiometer), this algorithm with geostationary satellite can improve the monitoring of AOD without the limitation of temporal resolution. Due to the limited number of channels in the conventional meteorological imager onboard the geostationary satellite, an AOD retrieval algorithm utilizing a single visible channel has been introduced. This single channel algorithm has larger retrieval error of AOD than other multiple-channel algorithm due to errors in surface reflectance and atmospheric property. In this study, the effects of manifold atmospheric and surface properties on the retrieval of AOD from the geostationary satellite, are investigated and compared with the AODs from AERONET and MODIS. To improve the accuracy of retrieved AOD, efforts were put together to minimize uncertainties through extensive sensitivity tests. This algorithm can be utilized to retrieve aerosol information from previous geostationary satellite for long-term climate studies.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.10
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• pp.2595-2606
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• 1995

Buoyancy-assisted melting of an unconstrained ice in an isothermally heated horizontal enclosure was numerically analyzed in a range of wall temperatures encompassing the density inversion point. The problem as posed here involves two physically distinct domains each of which has its own scales and respective heat transfer mode. These two domains join at the junction where the liquid squeezed out of the film region flushes into the lower melt pool. Both of these domains have been treated separately in the literature by a patching technique which invokes several, otherwise unnecessary, assumptions. The present study eliminates successfully such a superfluous procedure by treating the film and lower melt pool regions as a single domain. As a result of this efficient solution procedure, the interaction of the water stream ejected at the junction and the natural convection in the melt pool could be clarified for different wall temperatures. Though limited by two-dimensionality, the present results conformed indirectly the earlier reported transition of the flow pattern, as the wall temperature was increased over the density inversion point. The transient evolution of the melting surface, the time rate of change in melt volume fraction, the local and temporal variation of the heat transfer coefficients are analyzed and presented.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.11
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• pp.977-984
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• 2013

A hygroscopic rotor comprises many microchannels with high adsorption characteristics. In this study, the iterative adsorption/desorption processes that were affected by the humid air flow in a channel were numerically simulated. In consideration of the accuracy and computational costs, in the desiccant layer, only surface diffusion was considered in this simulation. The results were compared with the previous numerical results and found to show good agreement. By conjugating the heat and mass transfer between the desiccant and the flow layers, temporal and spatial changes in the vapor mass fraction, adsorbed liquid water mass fraction, and temperature in the channel were presented.

• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.197-200
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• 2015

Understanding the slag flow behavior is important in an entrained coal gasifier for its influence of ash discharge and wall heat transfer rate. This study presents a new model to predict the transient behavior of the liquid and solid slag layers. Unlike the previous steady-state model, the solid slag layer was included in solving the governing equations in order to identify the temporal and spatial transformation between the solid-liquid slag, rather than treating the solid region as a boundary condition of the liquid layer. The performance of the new model was evaluated for changes in the slag deposition rate (${\pm}10%$) and gas temperature (${\pm}50K$) in a simple cylindrical gasifier. The results show that the characteristic times to reach a new steady-state ranged between 80 s to 180s for the changes in the two parameters. Because the characteristic times of the gasifier temperature and slag deposition rate by changes in the coal type and/or operating conditions would be almost instantaneous, the time-scale for the slag thickness at the bottom of the gasifier to stabilize was much larger.

• Archives of Craniofacial Surgery
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• v.23 no.1
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• pp.39-42
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• 2022

The reconstruction of total lower eyelid defects is challenging to plastic surgeons due to the complicated anatomical structure of the eyelid. In addition, in the setting of cancer excision, the resection is deep, which requires some volume augmentation. However, in some cases, free tissue transfer is not applicable. We report a case of using a temporoparietal fascia flap (TPFF) for reconstructing a total lower eyelid defect. A large erythematous mass in an 83-year-old woman was diagnosed as squamous cell carcinoma by biopsy. After wide excision, the defect size was about 8×6 cm. The lower eyelid structures including the tarsus were removed. The TPFF including the superficial temporal artery was elevated and inset to the defect area. After the flap inset, a split-thickness skin graft with an acellular dermal matrix was performed on the fascial flap. There were no wound problems such as infection, dehiscence, or necrosis. After the patient's discharge, partial skin graft loss and ectropion occurred. The complications resolved spontaneously during the postoperative period. We report a case of reconstructing a lower eyelid defect using a TPFF. A TPFF can be applied to patients with large defects for whom free tissue transfer surgery is not appropriate as in this case.

• Archives of Craniofacial Surgery
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• v.25 no.1
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• pp.1-10
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• 2024

The facial nerve stimulates the muscles of facial expression and the parasympathetic nerves of the face. Consequently, facial nerve paralysis can lead to facial asymmetry, deformation, and functional impairment. Facial nerve palsy is most commonly idiopathic, as with Bell palsy, but it can also result from a tumor or trauma. In this article, we discuss traumatic facial nerve injury. To identify the cause of the injury, it is important to first determine its location. The location and extent of the damage inform the treatment method, with options including primary repair, nerve graft, cross-face nerve graft, nerve crossover, and muscle transfer. Intracranial proximal facial nerve injuries present a challenge to surgical approaches due to the complexity of the temporal bone. Surgical intervention in these cases requires a collaborative approach between neurosurgery and otolaryngology, and nerve repair or grafting is difficult. This article describes the treatment of peripheral facial nerve injury. Primary repair generally offers the best prognosis. If primary repair is not feasible within 6 months of injury, nerve grafting should be attempted, and if more than 12 months have elapsed, functional muscle transfer should be performed. If the affected nerve cannot be utilized at that time, the contralateral facial nerve, ipsilateral masseter nerve, or hypoglossal nerve can serve as the donor nerve. Other accompanying symptoms, such as lagophthalmos or midface ptosis, must also be considered for the successful treatment of facial nerve injury.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.1
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• pp.113-123
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• 2007

This study analyzed the appropriateness of the spatial distribution of fire stations and emergency medical facilities, the main providers of emergency medical care, in Busan. The area over which the 119 emergency medical services were situated in relation to the dispatch and transport of urgent rescue services was examined. Addresses of patients requiring 119 emergency services were obtained and stored as individual units so that they could be analyzed in a Geographic Information System(GIS). The time taken by emergency services to reach patients and transport them to a hospital or other facility was measured in seconds. By inputting additional information such as the location of the 119 dispatch centers, jurisdictions, and emergency medical facilities, the GIS allowed for analyses not only of the temporal but also the spatial aspects of emergency medical services. The results showed that of 16 Gu/Gun and 226 Eup/Myen/Dong in the Busan area, only 41% of Busan's emergency medical services could respond to and transport patients within five minutes. In all districts, most emergency medical services were provided within five to ten minutes. However, the pattern of hospital use to transfer patients to hospitals was inefficient. Based on the temporal and spatial distributions of fire stations and emergency medical agencies, and on their dispatch and transport times, this study sets out and compares ideal dispatch and transportation patterns for the efficient use of Busan's emergency medical services and resources.

• Journal of the Korean earth science society
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• v.30 no.7
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• pp.824-833
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• 2009

We analyzed a total of six months of geomagnetic data obtained at Cheonyang observatory, which is operated by Korean Meteorological Administration, to monitor earthquake precursors. Geomagnetic transfer functions (GTFs) and polarization values, which reflect the time-variations of the resistivity of subsurface, were estimated from 3-component geomagnetic data. The time-variant fluctuations were compared with the earthquake events occurred in the same period. Now that the daily GTFs show fairly irregular variations, we can not identify any correlation with the already occurred earthquakes and Kp index. On the other hand, we detect clear increases of the Ultra-Low-Frequency (ULF) band polarization values before the earthquakes, but the similar features are also observed even though the earthquake did not occur. This result may indicate that these time-variations are not just due to the earthquake precursor. For further understanding about these results, we need to investigate the relationship between the previous earthquake events and the geomagnetic data of other observatories.