• Geophysics and Geophysical Exploration
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• v.18 no.2
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• pp.39-53
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• 2015

Analysis of multi-channel seismic reflection profiles acquired from the southwestern margin of Ulleung Basin reveals that the cut and fill structures, which show U-shaped or V-shaped morphology, occur on variable size. The cut and fill structure mostly consists of fine-grained sediments on the well data and is characterized by transparent or semitransparent seismic facies on the seismic section. Such cut and fill structures dominantly occur in the syn-compressional megasequence (MSQ3), which was deposited during basin deformation of late Miocene, among the four megasequences of the study area. These cut and fill structures can be divided into three groups based on their size and formation time. The cut and fill structures of Group I were formed when Dolgorae structure was active, and occurred on a small scale. The cut and fill structures of group II were formed when both Dolgorae structure and Gorae V structure were active, and the number and size of those increased compared with group I. The cut and fill structures of group III were formed when Dolgorae structure was weaken gradually but Gorae V structure kept active, and the number and size of those decreased in comparison with group II. Consequently the cut and fill structures in the southwestern margin of Ulleung basin are interpreted as submarine canyon based on spatial distribution, size and fill sediment. They were controlled by the tectonic movement in response to basin closure and tectonic-induced sediment supply variation.

• Geophysics and Geophysical Exploration
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• v.17 no.2
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• pp.74-87
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• 2014

Analysis of multi-channel seismic reflection profiles collected from the Ulleung Basin reveals that the Quaternary sequence consists of four stratigraphic units separated by erosional unconformities. Individual stratigraphic unit includes eighteen mass transport deposits which are variable in geometric characteristics and spatial distribution. Each mass transport deposit on the seismic profile is acoustically characterized by chaotic or transparent seismic facies, and shows wedge or lens-shaped external geometry. The mass transport deposits, which comprise a succession of stacked wedges, mainly occur on the southern slope, and their thickness gradually decreases toward the basin plain. The time structure map of erosional unconformities shows that a tectonic-induced structural high and troughs toward the northwest and northeast are developed at the central part of the basin. Based on the isochron map, the mass transport deposits, originated from southern part of the study area, transported to the basin plain and can be divided into two groups by the structural high. Consequently, the mass transport deposits within the Quaternary sequence in the Ulleung Basin are largely controlled by the large amounts of sediment supply, dissociation of gas hydrate during the lowstands, and central structural high.

• The Korean Journal of Pain
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• v.18 no.1
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• pp.39-42
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• 2005

Background: Besides its general anesthetic effect, ketamine interacts with sodium channels in a local anesthetic-like fashion, including the sharing of binding sites with those commonly used by clinical local anesthetics. This study evaluated the dose related effects of ketamine during epidural anesthesia with 0.5% ropivacaine. Methods: Sixty ASA physical status I II patients, scheduled for minor elective surgery under epidural anesthesia using 0.5% ropivacaine, were randomly divided into three groups (n = 20 each). The patients initially received either 0.5% ropivacaine (group 1), ketamine (0.1 mg/kg) in addition to the epidural 0.5% ropivacaine (group 2) or ketamine (0.2 mg/kg) in addition to the epidural 0.5% ropivacaine (group 3). The regression of sensory block was assessed by transcutaneous electric stimulation (TES), equivalent to a surgical incision. Motor block was assessed using the Modified Bromage's scale. Episodes of bradycardia, hypotension and sedation were also recorded. Results: There were no significant differences among the three groups in the maximal levels of sensory block or the times taken for these levels to be reached. The mean times for the block to regress to two and four segments below the maximal level were significantly prolonged by epidural ketamine. Conclusions: Epidural ketamine prolongs the duration of ropivacaine epidural anesthesia. These results suggest that ketamine has local anesthetic-like actions.

• Journal of the Korean association of regional geographers
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• v.8 no.1
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• pp.65-82
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• 2002

This study tries to examine the characteristics of the ancient Dujiangyan Irrigation System and geographical conditions in the western part of Sichuan Basin in China. The Dujiangyan System constructed in the third century B.C is located at the mouth of gorge of the River Mi. This spot shows that its altitude above sea level is higher than that of the three other rivers in this district. Also, this river reaches the maximum discharge. These facts reveal the spot has the great potentiality as an ideal location for man-made channels. Li Bing realized the "three magical projects": Yuzui and Jinggang Dyke(a water dividing dyke), Baopingkou(a water inlet), and Feishayan(a spillway). The dyke divided the River Min into two parts. The inner river is connected to the Baopingkou. And the Feishayan discharges flood and silt from the inner river to the outer. These projects have composed a scientific irrigation and drainage network. Finally, in the Chengdu Plain were digged a dozen channels for irrigation. Some of them are connected eastward to the River Bu. Since then the Dujiangyan System has been bring great benefits to agricultural production. This resulted in the population increase and establishment of new counties which have made the plain a "Land of Abundance".

• Journal of Biomedical Engineering Research
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• v.21 no.4
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• pp.391-401
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• 2000

Flow through compliant tubes with linear taper in wall thickness is numerically simulated by finite element analysis. For verification of the numerical method, flow through a compliant stenotic vessel is simulated and the results are compared to the existing experimental data. Steady two-dimensional flow in a collapsible channel with initial tension is also simulated and the results are compared with numerical solutions from the literature. Computational results show that as cross-sectional area decreases with the reduction in downstream pressure, flow rate increases and reaches the maximum when the speed index (mean velocity divided by wave speed) is near the unity at the point of minimum cross-section area, indicating the flow limitation or choking (flow speed equals wave speed) in one-dimensional studies. for further reductions in downstream pressure, flow rate decreases. The flow limitation or choking consist of the main reasons of waterfall effect which occurs in the airways, capillaries of lung, and other veins. Cross-sectional narrowing is significant but localized. When the ratio of downstream-to-upstream wall thickness is 2, the area throat is located near the downstream end. As this ratio is increased to 3, the constriction moves to the upstream end of the tube.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.9 no.2
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• pp.10-24
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• 2005

Background and Purpose: Feeling the pulse is based on the pulse condition and alteration to observe the condition of the human body's health and by using a healthy person's pulse as a standard we are able to analyze the patient's pulse to find the attacked channel and collateral, viscera and bowels and understand the pathology such as diseases caused by exogenous evil, disorder of internal organs, and seven modes of emotions. Observing the color and shade of the patient's face, listening carefully to the sound of the patient, and feeling the pulse are methods in accordance with Su Wen 'Plain Questions', 'The Classic on Difficulty' (5th century B.C. Bianque), 'The Classic of Sphymology' (280 A.D. Wang Xi), 'Pulse Formulas' (1189 A.D. Cui Jiayan), and is systematically edited for those who have started studying to easily reach the profound state. Therefore, 'The Elementary Course for Medicine' has been used from ancient times as the textbook for diagnostics. Methods: In this Study, we will inspect commonly used pulse feeling methods, the inch, bar, cubit thesis, the viscera and bowels thesis from The Elementary Course for Medicine and inquire the difference of the text from 'Plain Questions of Huangdi's Internal Classic', 'Treatise on Febrile Diseases', 'Classic on Difficulty'. Results and Conclusion: 1. In 'The Elementary Course for Medicine' the site of the wrist along the pulsation of the radial artery is divided into inch, bar, cubit and has defined the inch, bar, cubit crossways. 2. In 'The Elementary Course of Medicine' the inch, bar, cubit for the left hand and right hand is subjected to each viscera and bowel. By assigning the left hand's inch, bar, cubit to the cardial orb, the hepatic orb, the renal orb, and the right hand's inch, bar, cubit to the pulmonic orb, the splenic orb, the vital gate it has been able to feel the pulse for each viscera and bowel by using the interpromoting and interacting relation of the five evolutive phases.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.2
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• pp.103-112
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• 2011

This study aims to demonstrate the relationship between various factors and soil erosion or deposition, simulated from distributed rainfall-sediment-runoff model applications. We selected area, overland flow length, local slope as catchment representative characteristics among many important geographic factors and also used the grid-based accumulated rainfall as a representative hydro-climatic factor to assess the effect of these two different types of factors on erosion and deposition. The study catchment was divided based on the Strahler's stream order method for analysis of the relationship between area and erosion or deposition. Both erosion and deposition increased linearly as the catchment area became larger. Erosion occurred widely throughout the catchment, whereas deposition was observed at the grid-cells near the channel network with short overland flow lengths and mild slopes. In addition, the relationship results between grid-based accumulated rainfall and soil erosion or deposition showed that erosion increased gradually as rainfall amount increased, whereas deposition responded irregularly to variations in rainfall. Within the context of these results, it can be concluded that deposition is closely related with the geographic factors used in this study while erosion is significantly affected by rainfall.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.2
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• pp.151-159
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• 2019

Pruritus (itching) is classically defined as an unpleasant cutaneous sensation that leads to scratching behavior. Although the scientific criteria of classification for pruritic diseases are not clear, it can be divided as acute or chronic by duration of symptoms. In this study, we investigated whether skin injury caused by chemical (contact hypersensitivity, CHS) or physical (skin-scratching stimulation, SSS) stimuli causes initial pruritus and analyzed gene expression profiles systemically to determine how changes in skin gene expression in the affected area are related to itching. In both CHS and SSS, we ranked the Gene Ontology Biological Process terms that are generally associated with changes. The factors associated with upregulation were keratinization, inflammatory response and neutrophil chemotaxis. The Kyoto Encyclopedia of Genes and Genomes pathway shows the difference of immune system, cell growth and death, signaling molecules and interactions, and signal transduction pathways. Il1a, Il1b and Il22 were upregulated in the CHS, and Tnf, Tnfrsf1b, Il1b, Il1r1 and Il6 were upregulated in the SSS. Trpc1 channel genes were observed in representative itching-related candidate genes. By comparing and analyzing RNA-sequencing data obtained from the skin tissue of each animal model in these characteristic stages, it is possible to find useful diagnostic markers for the treatment of itching, to diagnose itching causes and to apply customized treatment.

• Particle and aerosol research
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• v.14 no.4
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• pp.171-180
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• 2018

To optimize the shape of the electrostatic precipitator for the removal of particulate matter in subway environments, the wind-tunnel experiments were carried out to characterize collection efficiency and ozone emission rate. As a standardized parameter, power consumption divided by the square of flow velocity, was increased, the $PM_{10}$ collection efficiency increased. If the standardized parameter is higher than 1.0 due to high power consumption or low flow velocity, increase in thickness of electrodes from 1 to 2 mm, or increase in distance of collection plates from 5 to 10 cm did not change the $PM_{10}$ collection efficiency much. Increase in thickness of high-voltage electrodes, however, can cause decrease in $PM_{10}$ collection efficiency by 28% for low power consumption and high flow velocity. The ozone emission rate decreased as distance of collection plates became wider, because the ozone emission rate per unit channel was constant, and the number of collection channels decreased as the distance of collection plates increased. When the distance of collection plates was narrow, the ozone emission rate increased with the increase of the thickness of electrodes, but the difference was negligible when the distance of collection plates was wide. It was found that the electrostatic precipitator having a thin high-voltage electrodes and a narrow distance of collection plates is advantageous. However, to increase the thickness of high-voltage electrodes, or to increase the distance of collection plates is needed, it is necessary to increase the applied voltage or reduce the flow rate to compensate reduction of the collection efficiency.

• Fisheries and Aquatic Sciences
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• v.24 no.11
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• pp.360-369
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• 2021

Paralytic shellfish toxins (PSTs) and tetrodotoxin (TTX) are neurotoxins that display pharmacological activity that is similar to that of specific sodium channel blockers; they are the principle toxins involved in shellfish and puffer fish poisoning. In Korea, puffer fish is a very popular seafood, and several cases of accidental poisoning by TTX have been reported. Therefore, it is necessary to determine whether puffer fish poisoning incidents are caused by PSTs or by TTX. In this study, we used mouse bioassay (MBA) and liquid chromatograph-tandem mass spectrometry (LC-MS/MS) to determine the presence of PSTs and TTX in puffer fish from an area near Mireuk-do, Tong-Yeong on the southern coast of Korea from January through March, 2014. The toxicity of PSTs and TTX extracts prepared from three organs of each specimen was analyzed by MBA. Most of the extracts killed mice with typical signs of TTX and PSTs. The LC-MS/MS analysis of seven specimens of Takifugu pardalis and Takifugu niphobles, each divided into muscles, intestines, and liver, were examined for TTX. In T. pardalis, the TTX levels were within the range of 1.3-1.6 ㎍/g in the muscles, 18.8-49.8 ㎍/g in the intestines, and 23.3-96.8 ㎍/g in the liver. In T. niphobles, the TTX levels were within the range of 2.0-4.5 ㎍/g in the muscles, 23.9-71.5 ㎍/g in the intestines, and 28.1-114.8 ㎍/g in the liver. Additionally, the toxicity profile of the detected PSTs revealed that dcGTX3 was the major component in T. pardalis and T. niphobles. When PSTs were calculated as saxitoxin equivalents the levels were all less than 0.5 ㎍/g, which is below the permitted maximum standard of 0.8 ㎍/g. These findings indicate that the toxicity of T. pardalis and T. niphobles from the southern coast of Korea is due mainly to TTX and that PSTs do not exert an effect.