• Journal of Korean Society of Environmental Engineers
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• v.27 no.7
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• pp.726-731
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• 2005

Sedimentation is treated as the most important unit process in waterworks, and plays great role on turbidity removal efficiency. Rectangle sedimentation basin is the most widely accepted sedimentation process. But it has some problems with short-circuit flow and density flow caused by temperature and influent turbidity variation. To solve these problems, installation of rectification wall was suggested, but not generally fully accepted in field. Because hole of rectification wall cause jet flow. In this research, use of moving baffle was investigated. Moving baffle was designed to induce uniform velocity at every section of water flow. The baffle walls was made from soft fiber materials. The baffle walls with flow of sedimentation basin moves at same speed. It is like that it controls density flow and short-circuit flow and induce uniform velocity at every section of water flow in sedimentation basin. When moving baffle was operated retention time of sedimentation basin was extended to 1 hours. When it talked again and the effluent time of highest concentration of the chlorine ion from 100 minutes was extended to 160 minutes. Turbidity removal efficiency was tested with different operation modes(continuous and batch) with influent turbidity and retention time. It was revealed that turbidity removal efficiency carl be improved up to 36%(continuous mode) and 58%(batch mode) respectively. Consequently if moving baffle introduces in Rectangle sedimentation basin, it forecasts that the turbidity improvement above 30% will be possible.

• Korean Journal of Plant Taxonomy
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• v.40 no.4
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• pp.226-233
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• 2010

An intensive study of the embryology of Gymnospermium microrrhynchum was conducted to provide information regarding a discussion of the phylogenetic relationships of the genus, which is yet unstudied. Our results indicated that Gymnospermium is similar to other genera of Berberidaceae in terms of its embryological features. Nevertheless, newly reported and unique features are the well-developed endothelium and the undifferentiated seed coat type. Until the study of Gymnospermium, it may have been considered to be closer to Caulophyllum and Leontice in the tribe Leonticeae. These three genera share many morphological features as well as molecular similarities, by which they are kept in the same tribe, Leonticeae. However, very little detailed embryological data regarding these genera have been published thus far. Gymnospermium was characterized according to the basic type of anther wall formation as well as its glandular tapetum, successive cytokinesis in the microspore mother cell, two-celled mature pollen grains, anatropous and crassinucellate ovules with a nucellar cap, well-developed endothelium, its Polygonum type of embryo sac formation, its nuclear type of endosperm formation, and its undifferentiated seed coat type. In comparison with Nandina, there are many differences, such as the dehiscence of the anther, the cytokinesis in the microspore mother cells, the shape of the megaspore dyad, and the seed characteristics. Although we had no available detailed embryological information regarding Caulophyllum and Leontice, which are genera that are more closely related to Gymnospermium, we could deduce from the phylogenetic relationship that Gymnospermium, Caulophyllum, and Leontice are more closely related to each other than other genera of Berberidaceae on the basis of the seed characteristics.

• The Korean Journal of Nuclear Medicine
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• v.32 no.5
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• pp.403-413
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• 1998

Purpose: We investigated reproducibility of the quantification of left ventricular volume and ejection fraction, and grading of myocardial wall motion and systolic thickening when we used gated myocardial SPECT and Cedars quantification software. Materials and Methods: We performed gated myocardial SPECT in 33 consecutive patients twice in the same position after Tc-99m-MIBI SPECT We used 16 frames per cycle for the gating of sequential Tc-99m-MIBI SPECT. After reconstruction, we used Cedars quantitative gated SPECT and calculated ventricular volume and ejection fraction (EF). Wall motion was graded using 5 point score. Wall thickening was graded using 4 point score. Coefficient of variation for re-examination of volume and fraction were calculated. Kappa values (k-value) for assessing reproducibility of wall motion or wall thickening were calculated. Results: Enddiastolic volumes (EDV) ranged from 58 ml to 248 ml (122 ml +/- 42 ml), endsystolic volumes (ESV) from 20 ml to 174 ml (65 ml +/- 39 ml), and EF from 20% to 65% (51% +/- 14%). Geometric mean of standard deviations of 33 patients was 5.0 ml for EDV, 3.9 ml for ESV and 1.9% for EF. Their average differences were not different from zero (p>0.05). k-value for wall motion using 2 consecutive images was 0.76 (confidence interval: 0.71-0.81). k-value was 0.87 (confidence interval: 0.83-0.90) for assessment of wall thickening. Conclusion: We concluded that quantification of functional indices, assessment of wall motion and wall thickening using gated Tc-99m-MIBI SPECT was reproducible and we could use this method for the evaluation of short-acting drug effect.

• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.59-67
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• 1995

This study was conducted to develope the automatic insulation system which control inside temperature of the greenhouse. For this purpose, the double- wall greenhouse and system which could automatically supply and discharge styrene pellets were constructed and abrasion of the pellets, blower ability, insulating property, transmittance and shading effect were analyzed by the experiments. The results obtained from this study can be summarized as follows : 1. It took an hour and fifteen minutes to supply and discharge about 2㎥ pellets in the experimental greenhouse. However, it is possible to reduce the operation time by proper selection of the blower and exhaust port, and by proper control of the supply and return pipe. 2. It was founded that the indirect delivery way was more profitable than the direct one in the supply and return of pellets. 3. When the transmittance was measured between 10 a.m. and 3 p.m., the average light transmissivity rate was 67%. 4. In winter nighttime, the inside temperature of the double- wall greenhouse with out the pellets was higher than the outside temperature by 3.4$^{\circ}C$ on an average. However, the inside temperature of the double - wall greenhouse with insulated area 73% was higher than the outside by one 6.6$^{\circ}C$ on an average, and the inside temperature of the greenhouse with insulated area 100% was higher than outside one by 13.5$^{\circ}C$ on an average. Therefore, it was proved that the insulating ability of the double - wall greenhouse in nighttime was excellent. 5. When the outside temperature was 36.9$^{\circ}C$ on an average, the inside temperature of the double- wail greenhouse with insulated area 100% was 3$0^{\circ}C$ on an average. As the inside temperature was lower than the outside one by 7$^{\circ}C$ on an average, we could know that the shading effects of the double- wall greenhouse were excellent in summer daytime.

• Journal of the Korean GEO-environmental Society
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• v.6 no.4
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• pp.65-71
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• 2005

Recently, difficulties in soft ground improvement that caused by effectiveness of the ground improvement, the durability and environmentally friendliness of the injection material come to the fore. This paper studies the field applicability of the SCM in reinforcement and seepage cutoff of the back of an existing continuous wall. SCM uses double rod which imposes heavy pressure($10-100kgf/cm^2$) to disturbed, cut, discharge, and mix the ground. It is observed that a bulb is formed by using cement paste and environmentally friendly injection materials with minimal alkali leaching. Unconfined compression test and fish poison tests are performed. Test results indicate that the method results in higher durability, less leaching through use of the environmentally friendly injection material, and faster mobilization of the strength. In addition, field tests confirm the formation of the bulb and the seepage cutoff wall.

• Korean Chemical Engineering Research
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• v.45 no.1
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• pp.39-45
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• 2007

This paper proposed a shortcut method for the structure design of dividing wall column based on the Fen-ske-Underwood equation by applying it on three conventional simple column configuration. It is shown that the proposed shortcut method can design the column structure including the feed tray, dividing wall section, and side-stream tray in a simple and efficient way in the initial design stage. Simulation study using HYSYS to compare the energy saving performance between the conventional sequential two column system and the dividing wall column designed by the proposed method shows that the proposed dividing wall column system saves from 16% to 65% more over the condepends on the composition of intermediate component while the optimal energy consumption pattern to internal flow distribution on the dividing wall section is characterized by the ESI factor of the feed mixture.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1993.05a
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• pp.90-90
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• 1993

When illustrating the therapeutical plan of laryngeal cancer, there are difficulties in obtaining the three dimensional volume of tumor, submucosal extension of tumor, and particularly whether or not invasion on laryngeal cartilage has occurred. In particular clinical significance is the invasion to the laryngeal framework, which correlates with poor prognosis due to high frequency of local recurrence and cervical metastasis. Therefore the purposes of histopathological evaluation according to serial section study after laryngectomy are firstly, apprehension of the spread of laryngeal cancer and the pattern of invasion to laryngeal cartilage and secondly, obtaining an aid to establish direction of management to make higher the validity of preoperative clinical diagnosis. The following results were obtained : 1. The pattern of tumor invasion in cartilage 1) The tumor invades ossified cartilage chiefly and invades nonossified cartilage in extensive lesion only. 2) The tumor spread through intramarrow space at invaded ossified cartilage with intact perichondrium. 3) The perichondrium is strong barrier. 2. The incidence of cartilage invasion in order of frequency is as follow thyroid, arytenoid, cricoid, epiglottic cartilage. 3. The transglottic cancer has higher incidence(811.8%)of cartilage invasion. 4. The sensitivity, specificity, and accuracy rate of preoperative CT scan was 100%, 62.5%, 82.3% respectively.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.3
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• pp.194-204
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• 2007

A numerical analysis and hydraulic experiments were undertaken to investigate the head loss occurring when a flow passes through vertical perforated walls. The numerical analysis applied continuity, momentum and energy equations to the control volumes that were set near the perforated wall. Non-dimensional equations were then derived to calculate both upstream depth and head loss for the given values of downstream depth and velocity. The hydraulic experiments were performed with several single and triple perforated plates varying their opening ratios and intervals. The numerical results with the single plates were compared with the experimental results, and it was shown that the contraction coefficient of the vertical line jet formed after the perforated plates relies on downstream Froude number as well as opening ratio. Based on the experimental results, empirical formulas were formulated. Finally, the formulas were applied to the triple plates sequentially from downstream side to upstream side, and it was found that in general the predicted values nicely agreed with the experimental results.

• Journal of the Korean Geosynthetics Society
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• v.22 no.2
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• pp.85-92
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• 2023

This paper describes the comparative results of measured and predicted values for the horizontal displacement of earth retaining wall based on two field cases, in order to evaluate the application of lateral earth pressure to earth retaining wall supported by earth anchor in Jeju. The prediction of lateral earth pressure acting on the earth retaining wall was performed by elasto-plastic analysis using Rankine earth pressure, Hong & Yun lateral earth pressure, Terzaghi & Peck modified lateral earth pressure, and Tschebotarioff lateral earth pressure. As a result, the predicted value of the maximum horizontal displacement for site A was about 10 to 12 times greater than the measured value, and in the case of site B, the predicted value was evaluated as about 9 to 12 times greater than the measured value. That is, both sites showed a similar increase rate in the maximum horizontal displacement by the predicted value compared to the measured value. In all field construction cases, the maximum horizontal displacement by measured values occurred in the sedimentary layer, soft rock layer, and clinker layer, and the horizontal displacement distribution was shown in a trapezoidal shape. The maximum horizontal displacement by the predicted value occurred around the clinker layer, and the horizontal displacement distribution was elliptical. In the ground with a clinker layer, the measured value showed a very different horizontal displacement tendency from the predicted value, because the clinker layer exists in the form of a rock layer and continuous layer. In other words, it is unreasonable to apply the existing prediction method, which is overestimated, because the characteristics of the earth pressure distribution in Jeju show a tendency to be quite different from the predicted earth pressure distribution. Therefore, it is necessary to conduct a research on the lateral earth pressure in the realistic Jeju that can secure more economic efficiency.

• Tribology and Lubricants
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• v.1 no.1
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• pp.46-58
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• 1985

The basic mechanism of lubrication between the piston ring and the cylinder wall is developed theoretically under the assumption of a reciprocating and dynamically loaded slider-bearing pair of parabolic form and smooth plane. A numerical computation for the prediction in cyclic variations of film thickness, net lubricant flow and frictional behaviour is attempted, and the influenec on the performance characteristics due to the ring height, ring face radius of curvature and the degree of offset, is also examined. The computational procedures develeped for a single ring system are extended and applied further to the complex problem of a ring pack system. It is well known that the ring pressure which is the total load on a ring, can be obtained from either an experimental measurement or a gas flow analysis. In this work, the latter of a gas low analysis method was used to calculate the pressures. It is remarked that the work done was focused on the role of flow continuity and lubricant starvation within the ring pack lubrication.