• Korean Journal of Head & Neck Oncology
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• v.24 no.1
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• pp.57-63
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• 2008

Background and Purpose：Nausea, vomiting and weight loss are common problems that are encountered in the course of cancer patient treatment who are receiving radiotherapy. In this study, we are aiming to analyze the effect of megestrol acetate on quality of life of head and neck cancer patients receiving radiotherapy, resulting from improvement of weight loss, appetite and nutritional status via multicenter, open-labeled, observational clinical trial. Material and Methods：A total of 270 patients from 10 medical institutes who are receiving radiotherapy or who have completed radiotherapy within 3 months, between February 2007 and February 2008, were selected as candidates for the study. Megestrol acetate suspension(megace) was given to the subjectives once a week for 4 weeks with the amount of 20ml(megestrol 800mg). Measurement of weight and questionnaire surveys were carried out three times: at the start of the study, 4 weeks after the start of the medication, and 4 weeks after the end of the medication, respectively. Results：The group who has received megace had a total number of 199, and control group was 70. The group who have received megace showed mean weight loss of 1kg in 8 weeks, compared with the weight loss of 5.5kg in control group, which showed that the medication was effective in reducing the amount of weight loss(P=0.027). The group who received megace had a tendency to report a reduced rate of decrease in the score of appetite, nausea and vomiting, and QOL score, but it did not have statistical significance(P>0.05). Conclusion：Megestrol acetate have reduced the degree of weight loss significantly, and it has a tendency to reduce the rate of decrease in appetite, aggravation of nausea and vomiting, and quality of life.

• Journal of Clinical Otolaryngology Head and Neck Surgery
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• v.29 no.2
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• pp.240-244
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• 2018

Granulomatosis with polyangiitis (GPA) and Immunoglobulin (Ig) $G_4$-related disease ($IgG_4$-RD) are rare diseases and early diagnosis and proper management are imperative to prevent multi-organ damage. The authors present a case of a 60 years old woman who had facial paralysis and hearing loss. Lt intact canal wall tympanomastoidectomy, Lt facial nerve decompression and ossiculoplasty with partial ossicular replacement prosthesis (PORP) was done. During operation, middle ear tissue was biopsied and GPA with $IgG_4$-RD was diagnosed. After methyl prednisolone (MPD) pulse therapy and azathioprine therapy, the severity of paralysis was improved. We present this case because common otologic symptoms like facial palsy and hearing loss could be initial symptoms of rare systemic disease.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.789-795
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• 2005

This study proposes a modified bifurcation model with a computational fluid analysis according to variation of a bifurcation geometry. FLUENT is used for a calculation of the head losses in case of a generation and a pumping. The pressure, velocity field and turbulent intensity are simulated in a bifurcation. With consideration about these flow properties, we propose the modified model to improve a flow efficiency and reduce a sound. The proposed model is able to cut down a head loss by 45% when a generation and 36% when a pumping.

• Design & Manufacturing
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• v.13 no.2
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• pp.37-43
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• 2019

This study conducted a research as to condensation heat transfer friction loss headby using three types of flat micro multi-channel tubes with different processing of micro-fin and number of channels inside the pipes and different sizes of appearances. In addition, identical studies were conducted by using smoothing circular tubes with 5mm external diameter to study heat enhancement factor and pressure drop penalty factor. 1) The friction head loss showed an increase as the vapor quality and mass flux increased. In case of saturation temperature, it shows an increase as it gets lower. These factors are the reason occurring as the lower the saturation temperature is, the higher the density of refrigerant vapor gets. The influence of heat flux is similar as the dryness is low, but as it gets higher, it lowers in heat flux, and as the high temperature of high heat flux, it is a factor that occurs as the density gets lower. 2) RMS error of the in case of friction head loss, it showed to be predicted as 0.45~0.67 by Chisholm, Friedel, Lockhart and Martinelli. 3) As forfriction head loss penalty factor, the smaller the aspect ratio is, the larger the penalty factor gets, and as for the effect of micro-fin, the penalty factor increased because it decreases to the gas fluid the way groove for the refrigerant's flow.

• Research in Vestibular Science
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• v.17 no.4
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• pp.170-174
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• 2018

Epidural anesthesia has significantly advanced in neuraxial anesthesia and analgesia. It is used for surgical anaesthesia and treatment of chronic pain. Hearing loss during or after epidural anesthesia is rare, and it is known to occur by the change of the intracranial pressure. Cerebrospinal fluid is connected with perilymph in the cochlear and vestibule that is important to hearing and balance. If the intracranial pressure is abruptly transferred to the inner ear, perilymph can be leak, that called perilymphatic fistula, dizziness, and hearing loss can occur suddenly. We report a 65-year-old woman who presented with acute onset dizziness and hearing loss during the epidural nerve block for back pain, wherein we speculated a possibility of perilymphatic fistula as the mechanism of hearing loss and dizziness. The mechanism of dizziness and hearing loss was suspected with perilymphatic fistula.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.1
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• pp.107-112
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• 2009

This study was conducted for verification and systematization of estimation method about the headloss using CFD(Computational Fluid Dynamics). Head loss which happens between the inlet and outlet of in-line mixer can be a major factor for the design and construction. Also, this Case studies about the sensitivity related to the velocity in the piping system. As result, program's default calculation function was used to get each side's total pressure and the differential of each total pressure could be defined as head loss from in-line mixer. In the case of adopting pipe surface friction factor and geometry loss, Calculation residual can be much more reduced. It was found that residual of value between CFD method and field test ranged about 3 through 18 precent.

• Korean Journal of Hydrosciences
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• v.7
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• pp.77-86
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• 1996

An air chamber is design to keep the pressure from exceeding a predetermined value, or to prevent low pressures and colum separation. Therefore, it can be used to protect against rapid transients in a pipe system following abrupt pump stoppage. In this research, an air chmber was applied to a hypthetical pipe system to analyze attenuation effect of pressure head for different air volumes, locations, chamber areas, coefficients of orifice loss and pollytropic exponents. With an increase of air volume, the maximum pressure head at pump site is decreased and the minimum pressure head is imcreased. For different locations and areas of the chamber, the attenuation effects do not show much difference. Also, as the orifice loss coefficient increases, the maximum pressure head is decreased. For different polytropic exponents, isothermal process shows lower maximum pressure head than that of the adiabatic process.

• Genomics & Informatics
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• v.16 no.4
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• pp.20.1-20.20
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• 2018

Genetic hearing loss crosses almost all the categories of hearing loss which includes the following: conductive, sensory, and neural; syndromic and nonsyndromic; congenital, progressive, and adult onset; high-frequency, low-frequency, or mixed frequency; mild or profound; and recessive, dominant, or sex-linked. Genes play a role in almost half of all cases of hearing loss but effective treatment options are very limited. Genetic hearing loss is considered to be extremely genetically heterogeneous. The advancements in genomics have been instrumental to the identification of more than 6,000 causative variants in more than 150 genes causing hearing loss. Identification of genes for hearing impairment provides an increased insight into the normal development and function of cells in the auditory system. These defective genes will ultimately be important therapeutic targets. However, the auditory system is extremely complex which requires tremendous advances in gene therapy including gene vectors, routes of administration, and therapeutic approaches. This review summarizes and discusses recent advances in elucidating the genomics of genetic hearing loss and technologies aimed at developing a gene therapy that may become a treatment option for in the near future.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.2
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• pp.207-214
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• 2009

This study examines the optimum filtration conditions in pretreatment of seawater desalination by reverse osmosis. For this purpose, Masan bay seawater is treated through a gravity filter column while $FeCl_3$ is added as coagulant. The conditions of coagulantd osage, media depth, filtration rate, and backwash time are evaluated. The study results show that the filtrate quality improved with increasing coagulant dosage, but head loss rapidly increased. After 4mg/L, the unit filter run volume reduced to less than $200m^3/m^2$. Considering the head loss development, 4mg/L is determined as the optimum dosage. The better filtrate qualities are obtained with depth of 100cm than that of 80cm. The two stage filtration, which outperformed the single stage filtration, is suggested for treatment of Masan bay. The filtration rate of 5m/h is decided as the optimum condition considering the head loss development. At 10m/h, the filtrate quality deteriorated even though the extent was minimal, and head loss increased rapidly. The backwash time of 10 min is decided appropriate.

• Journal of the Korean Geotechnical Society
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• v.26 no.5
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• pp.37-48
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• 2010

In this study, the seepage flow monitoring method by the hydraulic head loss rate was developed for the purpose of application to offshore construction site enclosed by cofferdams in which seepage force varies periodically. The amount of the hydraulic head loss rate newly defined in this graph was in a range between 0 and 1. The zero of the rate means the existence of flow with no seepage resistance. The 1 of the rate means no seepage flow through the ground. The closer to 1 the coefficient of determinant in the hydraulic head loss graph is, the more the ground through which seepage water flows is stable. The closer to 0 the coefficient of determinant in the hydraulic head loss graph is, the more the ground through which seepage water flows was unstable and the higher the possibilities of existence of empty space or of occurrence of piping on the seepage flow pass in the ground is. The hydraulic head loss graph makes it possible to monitor sensitively the situation of seepage flow state, and the graph helps to understand easily the seepage flow state at the specific section on the whole cofferdam.