• Journal of Soil and Groundwater Environment
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• v.19 no.3
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• pp.39-46
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• 2014

Hydraulic conductivity is an important parameter, representing permeable property of the groundwater in aquifers, in the issues of groundwater development, groundwater contamination, and groundwater flow, etc. We estimated a relationship between hydraulic conductivity and electrical properties (formation factor, chargeability, and time constant) of silty sand in the laboratory. For this study, we conducted grain size analysis, constant head permeameter test, and measured electrical resistivity and spectral induced polarization of silty sand samples collected from the riverside alluvium of the Nakdong River in Nogok-ri area, Dasan-myeon, Goryeong-gun in Gyeongbook Province, Korea. In the laboratory test, we used soil samples of approximately uniform porosity with 0.5% error range, and kept the electrical resistivity of pore water with 100 ohm-m. As a result, the relationship between effective particle size and hydraulic conductivity agrees fairly well with the existing empirical formulas. Hydraulic conductivity was correlated with formation factor, chargeability, and time constant: hydraulic conductivity increased with increasing formation factor and time constant as well as with decreasing chargeability.

• The Korean Society of Law and Medicine
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• v.11 no.1
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• pp.199-239
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• 2010

In 2008, the Korean Supreme Court came across a plaintiff's claim to return his deceased father who had left family more than four decades ago and lived with another spouse(de facto) in the meantime to be buried after death in a cemetery of his own choice. The major opinion decided to approve the claim, on the ground that the first legitimate son should be the "head worshiper" prescribed in the article 1008-3 of the Korean Civil Code and that the corpse belong to the head woshiper, i. e. the head woshiper has a special "limited ownership" over the corpse for the purpose of its burial and worship, adding that a deceased's disposition inter vivos, if any, be only ethically but by no means legally binding others, including the head worshiper of course. Here scrutinized are the historical developments starting from the Roman criminal law of sepulchri violatio(trespass to grave) through the Canon law of the Middle Age and the doctrinal reactions to the challenges of anatomy and surgery to the formation of the "supporting the deceased" theory in Germany as well as the similarities in other european continental countries(Switzerland, Austria and France). The comparative review shows that the right of remaining family could neither be identified as limited "ownership" nor that the controversy over a corpse be solved by exclusively attributing/distributing it to one/some of the descendants. In principle, the question should be approached in the extension of family support.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.751-755
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• 2005

We propose a sound source localization method using the Head-Related-Transfer-Function (HRTF) to be implemented in a robot platform. In conventional localization methods, the location of a sound source is estimated from the time delays of wave fronts arriving in each microphone standing in an array formation in free-field. In case of a human head this corresponds to Interaural-Time-Delay (ITD) which is simply the time delay of incoming sound waves between the two ears. Although ITD is an excellent sound cue in stimulating a lateral perception on the horizontal plane, confusion is often raised when tracking the sound location from ITD alone because each sound source and its mirror image about the interaural axis share the same ITD. On the other hand, HRTFs associated with a dummy head microphone system or a robot platform with several microphones contain not only the information regarding proper time delays but also phase and magnitude distortions due to diffraction and scattering by the shading object such as the head and body of the platform. As a result, a set of HRTFs for any given platform provides a substantial amount of information as to the whereabouts of the source once proper analysis can be performed. In this study, we introduce new phase and magnitude criteria to be satisfied by a set of output signals from the microphones in order to find the sound source location in accordance with the HRTF database empirically obtained in an anechoic chamber with the given platform. The suggested method is verified through an experiment in a household environment and compared against the conventional method in performance.

• The korean journal of orthodontics
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• v.14 no.1
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• pp.53-65
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• 1984

The purpose of this study was to investigate the histopathological change and adaptation process of the mandibular joint of the rat by muscle alteration. For this study, one hundred and twenty eight rats of 25 - and 60 - day old of age were used. Unilateral and bilateral detachment, with anterior positioning of the Masseter muscle, was performed under anesthesia. The animal was sacrified 10, 20, 50, 80 days postoperatively. This alteration in muscle function led to change in neuromuscular activity and demonstrated the adaptive nature of the condyle cartilage to functional demand. The results were as follows : 1. In the right muscle detached group, operated at 25 days of age, marked decrease on the chondroblastic zone was found in the condyle head on the right side of animals examined 10 days postoperatively. Comparing with the control group, no difference was found on the chondroblastic zone in the condylar head of animals examined 20, 50 and 80 days postoperatively. 2. In the bilateral muscle detached group, operated at 25 days of age, the chondroblastic zone was slightly decreased in the anterior parts of condylar head of animals examined 10 days postoperatively. 3. In the unilateral and bilateral muscle detached group, operated at 60 days of age, no significant change was found in the mandibular joint regardless of the post operative experimental periods. 4. Under Toluidine blue staining, slightly decreased metachromasia was found in the condyle head on the right side of unilateral experimental animals, operated at 25 days of age and examined 10 days postoperatively. 5. Under Masson's trichrome staining, increased metachromasia was found in the condyle head on the right side of unilateral experimental animals, operated at 25 days of age and examined 10 days postoperatively. In summary, the condyle of the rat could respond to changes in neuromuscular activity depend on the level of maturation of the tissue, because the endochondral bone formation of the condyle of the rat was almost ended within 3 months.

• Fire Science and Engineering
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• v.30 no.6
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• pp.111-117
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• 2016

The present study examined the free surface flow of a liquid sheet near a sprinkler head using a Computational Fluid Dynamics (CFD) model and considered the feasibility of the empirical model for predicting the initial spray characteristics of the sprinkler head through a comparison of the CFD results. The CFD calculation for a simplified sprinkler geometry considering the nozzle and deflector were performed using the commercially available CFD package, CFX 14.0 with the standard $k-{\varepsilon}$ turbulence model and theVolume of Fluid (VOF) method. The predicted velocity of the empirical model at the edge of deflector were in good agreement with that of the CFD model for the flat plate region but there was a certain discrepancy between the two models for the complex geometry region. The mean droplet diameter predicted by the empirical model differed significantly from the measured value of the real sprinkler head. On the other hand, the empirical model can be used to understand the mechanism of droplet formation near the sprinkler head and predict the initial spray characteristics for cases without experimental data.

• Korean Journal of Head & Neck Oncology
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• v.33 no.1
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• pp.73-77
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• 2017

An 81 year-old male patient presented with rapid enlargement of left lateral neck mass, diagnosed two months earlier as cervical nontuberculous mycobacterial lymphadenitis. Abscess formation and impending rupture related to aggravation of nontuberculous mycobacterial lymphadenitis was highly suspected. Unexpectedly, blood flow was detected by Doppler ultrasonography, which indicated possible vascular mass. Computed tomography demonstrated a $6.0cm{\times}4.0cm$ sized enhancing mass consistent with pseudoaneurysm of internal carotid artery. The patient underwent pseudoaneurysmectomy. Surgical drainage without adequate evaluation might have led to potentially life-threatening condition. We describe this rare case with importance of imaging screening in a neck mass.

• Journal of Korea Water Resources Association
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• v.31 no.4
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• pp.363-373
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• 1998

In this study, random flow field in a nonstationary porous formation is characterized through cross covariances of the velocity with the log conductivity and the head. The hydraulic head and the velocity in saturated aquifers are found through stochastic analysis of a steady, two-dimensional flow field without recharge. Expression for these cross covariances are obtained in quasi-analytic forms all in terms of the parameters which characterize the nonstationary conductivity field and the average head gradient. The cross covariances with a Gaussian correlation function for the log conductivity are presented for two particular cases where the trend is either parallel or perpendicular to the mean head gradient and for separation distances along and across the mean flow direction. The results may be of particular importance in transport predictions and conditioning on field measurements when the log conductivity field is suspected to be nonstationary and also serve as a benchmark for testing nonstationary numerical codes. Keywords : cross covariance, nonstationary conductivity field, saturated aquifer, stochastic analysis.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.33 no.2
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• pp.110-114
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• 2022

IgG4-related disease is a fibroinflammatory condition by infiltration of IgG4-positive plasma cells that often presents as a tumorous lesion. This disease can affect nearly every organ system. After the pancreas, the head and neck region is second most common site for presentation of IgG4-related disease such as Mikulicz's disease, Küttner tumor. The involvement of IgG4-related disease in laryngeal lesions is extremely rare. We have experienced a case of IgG4-related disease with pseudotumor formation in the larynx that is suggestive of malignancy in radiologic findings. But the pathology findings was finally confirmed as IgG4-related disease. Oral treatment with prednisolone was initiated, and the edematous mass reduced in size without permanent functional impairment of vocal fold mobility. We report our experience with a literature review.

• Journal of Audiology & Otology
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• v.23 no.2
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• pp.69-75
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• 2019

Background and Objectives: The antioxidant ebselen will be able to limit or prevent the ototoxicity arising from 2-hydroxypropyl-β-cyclodextrin (HPβCD). Niemann-Pick Type C (NPC) disease is a disorder of lysosomal storage manifested in sphingolipidosis. Recently, it was noted that experimental use of HPβCD could partially resolve the symptoms in both animals and human patients. Despite its desirable effect, HPβCD can induce hearing loss, which is the only major side effect noted to date. Understanding of the pathophysiology of hearing impairment after administration of HPβCD and further development of preventive methods are essential to reduce the ototoxic side effect. The mechanisms of HPβCD-induced ototoxicity remain unknown, but the resulting pathology bears some resemblance to other ototoxic agents, which involves oxidative stress pathways. To indirectly determine the involvement of oxidative stress in HPβCD-induced ototoxicity, we tested the efficacy of an antioxidant reagent, ebselen, on the extent of inner ear side effects caused by HPβCD. Materials and Methods: Ebselen was applied prior to administration of HPβCD in mice. Auditory brainstem response thresholds and otopathology were assessed one week later. Bilateral effects of the drug treatments also were examined. Results: HPβCD-alone resulted in bilateral, severe, and selective loss of outer hair cells from base to apex with an abrupt transition between lesions and intact areas. Ebselen co-treatment did not ameliorate HPβCD-induced hearing loss or alter the resulting histopathology. Conclusions: The results indirectly suggest that cochlear damage by HPβCD is unrelated to reactive oxygen species formation. However, further research into the mechanism(s) of HPβCD otopathology is necessary.

• Korean Journal of Audiology
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• v.23 no.2
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• pp.69-75
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• 2019

Background and Objectives: The antioxidant ebselen will be able to limit or prevent the ototoxicity arising from 2-hydroxypropyl-β-cyclodextrin (HPβCD). Niemann-Pick Type C (NPC) disease is a disorder of lysosomal storage manifested in sphingolipidosis. Recently, it was noted that experimental use of HPβCD could partially resolve the symptoms in both animals and human patients. Despite its desirable effect, HPβCD can induce hearing loss, which is the only major side effect noted to date. Understanding of the pathophysiology of hearing impairment after administration of HPβCD and further development of preventive methods are essential to reduce the ototoxic side effect. The mechanisms of HPβCD-induced ototoxicity remain unknown, but the resulting pathology bears some resemblance to other ototoxic agents, which involves oxidative stress pathways. To indirectly determine the involvement of oxidative stress in HPβCD-induced ototoxicity, we tested the efficacy of an antioxidant reagent, ebselen, on the extent of inner ear side effects caused by HPβCD. Materials and Methods: Ebselen was applied prior to administration of HPβCD in mice. Auditory brainstem response thresholds and otopathology were assessed one week later. Bilateral effects of the drug treatments also were examined. Results: HPβCD-alone resulted in bilateral, severe, and selective loss of outer hair cells from base to apex with an abrupt transition between lesions and intact areas. Ebselen co-treatment did not ameliorate HPβCD-induced hearing loss or alter the resulting histopathology. Conclusions: The results indirectly suggest that cochlear damage by HPβCD is unrelated to reactive oxygen species formation. However, further research into the mechanism(s) of HPβCD otopathology is necessary.