• The Journal of Engineering Geology
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• v.24 no.1
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• pp.111-122
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• 2014

For accurate laboratory evaluations of soil deposits, it is essential that the samples are undisturbed. An artificial ground-freezing system is the one of the most effective methods for obtaining undisturbed samples from sand deposits. The objective of this study is to estimate the shear strengths and the characteristics of elastic waves of frozen-thawed and unfrozen specimens through the undrained triaxial compression test. For the experiments, Jumunjin standard sands are used to prepare frozen and unfrozen specimens with similar relative densities (60% and 80%). The water pluviation method is used to simulate the fully saturated condition under the groundwater table. When thawing the frozen specimens, the temperature is measured every minute. After the specimens are completely thawed, undrained triaxial compression tests are conducted using the same procedures as for the unfrozen specimens. During the triaxial tests (saturation, consolidation, and shear phase), compressional and shear waves are measured. The results show that the freeze-thaw process has minor effects on the peak deviatoric stress and shear strength values, and that the process does not affect the internal friction angle. The compressional wave velocity increases with increasing B-value to 1800 m/s in the saturation phase, but tends to remain constant in the process of consolidation and shearing. The shear wave velocity decreases with increasing B-value in the process of saturation, but changes velocity in accordance with the change in effective stress in the processes of consolidation and shearing. The compressional wave velocity has similar values regardless of the freeze-thaw process, but values of shear wave velocity are slighly lower in frozen-thawed specimens than in unfrozen specimens. This study is a preliminary experiment for estimating the shear strength and characteristics of elastic wave velocity in undisturbed frozen specimens that have been obtained using the artificial ground-freezing method.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.16 no.1
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• pp.27-38
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• 2004

In this study, the reliability design method developed by Shimosako and Takahashi in 1999 for calculation of the expected sliding distance of the caisson of a vertical breakwater is extended to take into account the variability in wave direction such as directional spreading of waves, obliquity of the deep-water design principal wave direction from the shore-normal direction, and its variation about the design value. To calculate the transformation of random directional waves, the model developed by Kweon et al. in 1997 is used instead of Goda's model, which was developed in 1975 for unidirectional random waves normally incident to a straight coast with parallel depth contours and has been used by Shimosako and Takahashi. The effects of directional spreading and the variation of deep-water principal wave directions were minor compared with those of the obliquity of the deep-water design principal wave direction from the shore-normal direction, which tends to reduce the expected sliding distance as it increases. Especially when we used the field data in a part of east coast of Korea, considering the variability in wave directions reduced the expected sliding distance to about one third of that not considering the directional variability. Reducing the significant wave height calculated at the design site by 6％ to correct the effect of wave refraction neglected in using Goda's model was found to be proper when the deep-water design principal wave direction is about 20 degrees. When it is smaller than 20 degrees, a value smaller than 6％ should be used, or vice versa. When we designed the caisson with the expected sliding distance to be 30㎝, in the area of water depth of 25 m or smaller, we could reduce the caisson width by about 30％ at the maximum compared with the deterministic design, even if we did not consider the variability in wave directions. When we used the field data in a part of east coast of Korea, considering the variability in wave directions reduced the necessary caisson width by about 10% at the maximum compared with that not considering the directional variability, and is needed a caisson width smaller than that of the deterministic design in the whole range of water depth considered (10∼30 m).

• Economic and Environmental Geology
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• v.35 no.3
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• pp.203-210
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• 2002

In order to elucidate the growth mechanism of sulfide chimney formed as a result of seafloor hydrothermal mineralization, we carried out the mineralogical and fluid inclusion studies on the inactive, sulfide- and silica-rich chimney which has been recovered from a hydrothermal field in the Cleft segment of the Juan de Fuca Ridge. According to previous studies, many active and inactive vents are present in the Cleft segment. The sulfide- and silica-rich chimney is composed of amorphous silica, pyrite, sphalerite and wurtzite with minor amounts of chalcopyrite and marcasite. The interior part of the chimney is highly porous and represents a flow channel. Open spaces within chimneys are typically coated with colloform layers of amorphous silica. The FeS content of Zn-sulfides varies widely from 13.9 to 34.3 mole% with Fe-rich core and Fe-poor rims. This variation possibly reflects the change of physicochemical characteristics of hydrothermal fluids. Chemical and mineralogical compositions of the each growth zone are also varied, possibly due to a thermal gradient. Based on the microthermometric measurements of liquid-rich, two-phase inclusions in amorphous silica that was precipitated in the late stage of mineralization, minimum trapping temperatures are estimated to be about 1140 to 145$^{\circ}$C with the salinities between 3.2 and 4.8 wt.% NaCI equiv. Although the actual fluid temperatures of the vent are not available, this study suggests that the lowtemperature conditions were predominant during the mineralization in the hydrothermal field at Cleft segment. Comparing with the previously reported chimney types, the morphology, colloform texture, bulk chemistry, and a characteristic mineral assemblage (pyrite + marcasite + wurtzite + amorphous silica) of this chimney indicate that the chimney have been formed from a relatively low-temperature (<250$^{\circ}$C) hydrothermal fluid that was changed by sluggish fluid flow and conductive cooling.

• Journal of Korean Society of Forest Science
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• v.101 no.1
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• pp.36-45
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• 2012

Education on the environment and plants offered by arboretum for today's people not only contribute to foster a better natural environment in urban region but also provide visitors with decent refreshment environment and beyond. In the study, the author undertook the observation on usage behavior and satisfaction model of arboretum visitors expect and investigated the facilities and programs to be offered by arboretum in order to propose the opinion regarding the service. For observation size of variables in a multiple regression analysis of variables is influencing satisfaction rankings walks the line of flow, the educational effect on the environment, cleanliness of the facility, visits pay, natural beauty, diversity of trees, accessibility and friendliness of staff, expansion of facilities in the arboretum and appeared as a complement. In case of visitor attribute, the residents living near the facility showed the highest visit frequency of more than 5 times, especially as part of taking a walk. This proves that the visit to arboretum is considered as part of everyday life, and thus a new program and walk path as well as movement route are needed to be developed for the visitors. In the question relating to the facilities and operation programs in Daegu Arboretum, particularly the requests by visitors, they responded that the establishment of cultural event, beautiful natural scenery, refreshment and convenience facilities is the most critical issue. In addition, the management on withered trees and bare lands is an urgent issue as well. In this sense, the Operation and Management Strategies based upon the visitor behaviors and model of satisfaction are needed to deal with the adoption of diverse events and festivals joined by local residents, ombudsman program, environmental program development for students and teachers within the region, negligent bare lands and withered tree replacement, and cafeteria facility improvement and supplement as well as the bench marking of other facilities than arboretums located in other regions. These items are thought to be sufficiently dealt with by Daegu Arboretum having no more external resources. It is recognized that the visitor satisfaction begins from a minor thing, and a small difference determines a great satisfaction, and thus the software approach rather than hardware one is in need.

• Journal of Chest Surgery
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• v.19 no.1
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• pp.35-42
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• 1986

Prevention of thrombombolism after rosthetic cardiac valve replacement is essential for the patients. About 90% of patients are free of major and minor thromboembolic complications 5 year after replacement of cardiac valves with prosthetic devices when they are under control of anticoagulant therapy. Ticlopidine is a drug that alter platelet function to have an antithrombotic effect. It is an antiaggregating agent which inhibits primary platelet function to have an antithrombotic effect. It is an antiaggregating agent which inhibits primary platelet aggregation induced by ADP and increases the production of prostaglandin $D_{2}$. Aspirin in small doses inhibits platelet synthesis of prostaglandins by irreversibly blocking the enzyme cyclo-oxygenase. Platelet secretion and aggregation are impaired with Ticlopidine and Aspirin. the thromboembolic event sof 54 patient s who were treated with Ticlopidine and Aspirin after cardiac valve replacement were evaluated and compared with that of 79 patients who were treated with Wafarin and Aspirin after the same type of operation. The follow-up period ranged from 4 to 110 months (mean of 48 months). there were 11 major thromboembolic episodes including three deaths in the warfarin goup during mean follow-up period of 56 months. two cases of CVA and one hemoarthrosis were noted due to overdose of Warfarin. Inticlopidine group, there was only one fatal thromboembolic epdisode three month after mitral valve replacement during mean follow-up period of 18 months. Two episodes of hypermenorrhea resulting anemia ere noted in the ticlopidine group. We measured the parameters of platelet function in aggreagation curve of platelet with platelet aggregometer (chrono-log Aggregometer, Model No. 430) Aggregation test was performed with three final concentrations of epinephrine in 10 uM/L, ADP in 5uM/L. 28 patients with prosthetic cardiac valves and 35 healthy volunteers were subgrouped as follows to analyze the effect of antithrombotic drugs used. Group I ; 11 patients treated with 250-500 mg of ticlopidine and 0.5gm of Aspirin as a daily single dose after cardiac valve replacement (14 St. Jude Medical and 1 Carpentier-Edwards, 9 patients with atrial fibrillation among them) Group II ; 10 patients treated with 3-5 mg of Warfarin and 0.75 gm of Aspirin daily to prolong prothrombin time around 20 seconds for more than 6 months and single Aspirin dose was maintained afterward as a life-long regimes(3 St. Jude Medical, 1 Hall-Kaster and 7 Carpentier-Edwards valve, 9 patients in atrial fibrilation). Group III ; 7 patients who quit anticoagulant treatment (Warfarin + Aspirin) 6-12 months after the regime as group II (3 St. Jude Medical. 1 bjork-Shiley, 1 Hall-Kaster, 3 Carpentier-Edwards valve, 2 of them are with atrial fibrillation). Group IV ; 35 healthy vounteers (28 males and 7 females). The following results were obtained. 1. The mean maximal platelet aggregability in Group I induced by 10uM/L epinephrine was 15.6%, and 17.5 and 18.7% in BM in proportion to the induction by 5 and 10 uM/L ADP. 2. The mean maximal platelet aggregability in Group II induced by 10uM/L epinephrine was 16.5%, and 27.4 and 44.7% in BM in proportion to the induction by 5 and 10uM/L ADP. 3. The mean maximal platelet aggregability in group III induced by 10uM/L epinephrine was 65%, and 56.5 and 51.8% in BM in proportion to the induction by 5 and 10 uM/L ADP. 4. The mean maximal platelet aggregability in the normal subjects induced by 10 uM/L epinephrine was 64%, and 65 and 69% in Bm inproportion to the induction by 5 and 10 uM/L ADP. 5. Reversible change of platelet aggregation curve induced by 5 and 10uM/L was noted all of the patients in Group I. conclusion : Ticlopidine is an antiaggregating agent which inhibits primary platelet aggregation induced by ADP, and increases the production of prostaglandin $D_{2}$. Ticlopidine and Aspirin produced a significant inhibition of platelet in the presence of ADP and epinephrine in our study. Acccording to our brief experience, 250 mg of ticlopidine and low dose of Aspirin resulted synergistic superior effect to each drug alone in prevention of thromboembolism after prosthetic cardiac valve replacement.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.386-395
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• 2007

A total of 27 strains of Vibrio parahaemolyticus (18 strains isolated from Korea and 9 strains from Japan) were serotyped and examined for biochemical characteristics, antimicrobial susceptibility patterns, cytotoxicity assay, thermostable direct hemolysin (TDH) production and molecular epidemiology. Using polymerase chain reaction (PCR) method and DNA probe hybridization method, the strains were tested for toxR, tdh, trh and ORF 8 genes. The V. parahaemolyticus isolated from patients were belonged to 8 different serotypes : O3:K6, O1:K38, O3:K57, O4:K9, O4:Kl2, O4:K68, O5:Kl5 and O6:K46. Urease-positive strain possessed the trh gene, and conversely, urease-negative strains lacked the gene, indicating that urease production by V. parahemolyticus strains strongly correlates with the possession of the trh gene. Most strains showed multiple resistant to more than three antibiotics and the antibiogram could be classified into 6 group (I to VI). All of the O3:K6 strains isolated in South Korea and Japan producted TDH at high levels. The TDH titers ranged between 256 and 2.048, and the average titer was 1009. To distinguish the new and increasingly common V. parahaemolyticus strains from clinical isolates, ORF 8 is a useful genetic marker. After Southern hybridization, the HindIII restriction fragment patterns of the tdh gene were grouped one type, respectively. One type showed two bands one of which was 4.3kb and the other was 11.5kb in size. Variation between the O3:K6 serotype are minor when compared to the differences seen with the non O3:K6 strains. The migration patterns of Not I -digested of the total DNA of the O3:K6 strains were similar, and only slight variations were observed between the serotypes. By contrast, the O3:K6 strains and non O3:K6 had markedly different profiles. In conclusion, Random amplified polymorphic DNA (RAPD) profile using appropriate primers was an effective epidemiological marker.

• 한국해양학회지
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• v.1
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• pp.1-15
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• 1971

Some major and minor geochemical contents, such as Zr, Br, Ni, Sr, Zn, Mn, Ti and Fe, of ninety-seven sediment samples from the sea off eastern Korea have been analyzed by the fluorescence spectrometric techniques. Concentrations of elements showed 22-962ppm Zr(averaging 194.4ppm), tr-220 ppm Br(averaging 138.2ppm), 31-141ppm Ni(averaging 89.1ppm), 118-3,494ppm Sr(averaging 448.6ppm) 27-134ppm Zn(averaging 92.5ppm), 38-1,043ppm Mn(averaging 664.2ppm), 0.04-0.42% Ti(averaging 0.29%) and 0.57-4.02% Fe(averaging 2.76%). The ratios of Zn/Ti 10$\^$3/, An/Fe 10$\^$3/ and Ti/Fe were 0.27-6.43(averaging 3.27), 2.25-7.76 (averaging 3.46) and 0.04-0.18(averaging 0.11), respectively. From the results of geochemical analyses of sediments from the sea off eastern Korea represented the different types of sediment pattern are considered between the southern part and the northern part of the sea. The bottom sediments of the southern part were characterized with higher Sr and lower Zn, Br contents; higher Zr and lower Br contents; lower Br and lower Zn, Ti and Fe contents; and lower Zn and lower Ti and Fe contents.

• Korean Journal of Food Science and Technology
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• v.6 no.1
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• pp.30-35
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• 1974

As studies on the starch properties of barley and naked barley, the granule size frequency distribution, amylose content and blue value of starches seperated from the 11 varieties of barley and 13 varieties of naked barley, which were grown paddies of Office of Rural Development, Iri, Korea in 1972, were determined. The results were as follows: 1. The type of the barley and naked barley starch granules was short oval and the ratio of minor axis to major axis was 1 to 1.2. Diameter of the starch granules was in the range of $4.0{\sim}6.0\;{\mu}$ to $32.0{\sim}37.0\;{\mu}$ is and medium granule of the naked barley was $10{\sim}22\;{\mu}$ on the contrary to $16{\sim}20\;{\mu}$ of the barley starch. Average size of the naked barley starch was larger than that of the barley and some differences were observed between varieties. 2, Amylose contents of the barley and the naked barley starches were in the range $27.5{\sim}30.5%$ and average of the barley was 29.4% a little higher than 28.2% of the naked barley and observed of some differences between varieties. 3. Blue values of the barley and the naked barley starches were in the range $0.47{\sim}0.54$, and average was 0.51.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.3
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• pp.169-178
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• 2003

This pot experiment was conducted to find out the effects of boron application($B_{0}$ ; control, $B_1$; 0.2, $B_2$; 2.0, B$_3$; 6.0, $B_4$; 15.0 boron me/pot) on the forage performance of pure and mixed cultures of orchardgrass and white clover. The third part was concerned with the changes in the contents and yields of nitrogen compounds(crude/pure protein and soluble N-compound) in forages. The results obtained are summarized as follows: 1. With no additional fertilization, especially nitrogen, in a pure culture, the $B_{0}$ and $B_4$ treatments on white clover decreased the amount of crude/pure protein, and showed nitrogen deficiency symptoms. However, the optimum boron application($B_2$) positively resulted in the increase of crude and pure protein, especially pure protein, and the content ratio of pure protein/soluble N-compounds. With additional fertilization, especially nitrogen, differences were not found among the boron treatments($B_{0}$, $B_2$, and $B_4$). 2. Owing to the decline of white clover as affected by the additional fertilization, especially nitrogen, in the grass-clover mixed cultures, the effects of B-application on these contents of white clover were different and relatively low, compared with the pure cultures. But the positive effect of $B_2$ treatment tended to be similar to the pure cultures. Also, it was recognized that the $B_2$ treatment resulted in the increase of their contents in orchardgrass, however, the effect was relatively minor compared with that of white clover. 3. The optimum B application(B$_2$) on white clover influenced relatively better on the yields of crude and pure protein than on the dry matter yields, especially with no additional fertilization. The effects of boron application on the contents and yields of crude and pure protein were different according to the forage species, whether it was a pure or mixed culture, and additional fertilization.

• Journal of Hospice and Palliative Care
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• v.6 no.1
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• pp.11-21
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• 2003

This paper addresses the minor differences in the description of pain in Korean language in order to develop a standarized cancer pain aneument tool for Korean adults, Korean Cancer Pain Assessement Tool. The subtle differences in the meaning of expressions used cannot be translated into English and therefore we omiltted the English abstract.