• Journal of Korea Water Resources Association
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• v.38 no.7 s.156
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• pp.527-535
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• 2005

The computation of normal depth is very important for the design of channel and the analysis of water flow. Drainage pipe generally has the shape of curvature like circular or U-type, which is different from artificial triangular or rectangular channel. In this case, the computation of normal depth or the derivation of equations is very difficult because the change of hydraulic radius and area versus depth is not simple. If the ratio of the area to the diameter, or the hydraulic radius to the diameter of pipe is expressed as the water depth to the diameter of pipe by power law, however, the process of computing normal depth becomes relatively simple, and explicit equations can be obtained. In the present study, developed are the explicit normal depth equations for circular and U-type pipes, and the normal depth equation associated with Hagen (Manning) equation and friction factor equation of smooth turbulent flow by power law is also proposed because of its wide usage in engineering design.

• Journal of Korean Neurosurgical Society
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• v.63 no.4
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• pp.513-518
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• 2020

Objective : Chronic subdural hematoma (CSDH) is one of the most common intracranial hemorrhages. It can be managed with a simple surgical treatment such as burr-hole trephination and drainage. However, it has a relatively high recurrence rate. The mechanisms and risk factors for the recurrence have not yet been clearly identified and studies have reported varying results. Methods : We analyzed 230 patients with CSDH who were treated with burr-hole trephination and drainage at our institution from March 2011 to March 2016. The patients were divided into recurrence and non-recurrence groups and the medical records of each group were used to analyze the risk factors associated with CSDH recurrence. Results : After burr-hole trephination and drainage, CSDH recurrence was observed in 49 (21.3%) of the 230 patients. In univariate analysis, none of the factors showed statistical significance with respect to CSDH recurrence. In multivariate analysis, preoperative antithrombotic medication was the only independent risk factor for CSDH recurrence (odds ratio, 2.407; 95% confidence interval, 1.047-5.531). Conclusion : The present study found that preoperative antithrombotic medication was independently associated with CSDH recurrence.

• Archives of Plastic Surgery
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• v.44 no.4
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• pp.308-312
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• 2017

Background Donor site seroma is the most common complication after latissimus dorsi (LD) flap harvest. This study aimed to evaluate the efficacy of negative-pressure wound therapy (NPWT) in preventing donor site seroma formation after the harvest of an LD flap for breast reconstruction. Methods In this prospective matched-pair study, 40 patients in whom an LD flap was harvested for breast reconstruction were enrolled. NPWT was used in 20 patients, and in a control group composed of another 20 patients, the conventional donor site dressing technique was used. Information was collected regarding postoperative complications, the incidence of seroma, total drainage volume, the number of percutaneous seroma aspirations, and the volume aspirated. Results In the NPWT group, the incidence of seroma formation after drain removal was significantly lower than in the control group (15% vs. 70%; odds ratio=0.07; relative risk, 0.24). Both the mean percutaneous aspirated volume (P =0.004) and the number of percutaneous aspirations (P=0.001) were also significantly lower in the NPWT group. There were no significant differences in the total drainage volume or the duration of wound drainage between the NPWT dressing group and the control group (P>0.05). Conclusions This study showed that NPWT is a promising tool for reducing the incidence of seroma formation after removing the drain at the donor site after LD flap harvesting. It is a simple and safe technique.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.3
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• pp.276-281
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• 1985

This study was conducted to examine the morphological, physical and chemical characteristics of the Song-jeong (residuum), Dae-gog (local colluvium-alluvium), Ji-san and Og-cheon (local-alluvium) series with fine loamy texture derived from fine granitic parent materials on the drainage catena. 1. These soils consist of a catena, and then a color sequence due to the influence of topography, water table and free iron content. 2. The poorer the drainage, the higher were the silt/clay ratio, soil reaction, organic matter, and available phosphate content in soils but the active iron content was lower.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.10a
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• pp.100-107
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• 2002

This study investigates the seasonal variation and spatial distribution characteristics of pollutant load, as executing the quantity valuation of pollutant load inflowing into Yeong-Il bay from on-land including the Hyeong-san river. Annual total pollutant generating rate from Yeong-Il bay region are 202ton to BOD, 620ton to SS, 42ton to T-N, 16ton to T-P respectively, if expressly point out, pollutant generating rate from the Hyeong-san river is the greatest, which BOD ratio is 78.2%, SS 88.5%, T-N 62.5%, T-P 73.1%. As calculating Tank model with input value of daily precipitation and evaporation of 2001 year in drainage basin of the Hyeong-san river, Estimated result of the annual total river discharge effluencing from this river is $830{\times}106m^3$. As result to estimating annual total effluence rate outflowing at the rivers from each drainage basins, annual total inflow pollutant rate are BOD 10,633ton, SS 19,302ton, T-N 15,369ton, T-P 305ton. The III basin which is population congestion region of the Pohang-city drain away a good many pollutant load than the V basin including the Neang-Chun with wide drainage area. Especially, a great many T-N than T-P inflow into Yeong-Il bay. The accumulation of pollutant load effluenced from on-land will happen on at the inner coast region of Yeong-Il bay, finally we would make a prediction that the water quality will take a bad turn.

• Journal of Chest Surgery
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• v.1 no.1
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• pp.19-24
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• 1968

A clinical investigation was reported on 17 cases of spontaneous pneumothorax requiring surgical mana-gement. Males outnumbered females 15:2. Determination of the etiology in this series showed that the majority were pulmonary tuberculosis and paragonimiasis. Several others had pneumonia, lung abscess, cyst and blebs. It is of particular interest that the acute inflammation of respiratory system was younger age group, pulmonary tuberculosis & paragonimiasis were between 2 nd and 3 rd decades, and lung abscess, cyst, blebs were above 4 th decade. Pulmonary tuberculosis was far advanced bilateral and active. The ratio of right to left side was 13:6 and both side involved in 2 cases. In about half cases of patients, above 50%-collapsed lung associated with mediastinal shifting developed. The complications were pleural effusion and bronchopleural fistula. The former was 13 cases [76.4%] in which 3 cases combined with mixed infection, and latter was 5 cases. As the management, 11 cases were subjected to intercostal or rib resection drainage with continuous suc-tion. Among 11 drainage cases, 8 cases were successful in acute stage and 3 cases failed in chronic stage. This faiure was due to interference with re-expansion of collapsed lung for peel formation and broncho-pleural fistula. The open thoractomy was applied in 9 cases, among which primary operation were 5 cases and drainage failure were 4 cases. Among 11 cases subjected to the open thoracotomy, wedged resection was performed in 3 cases including paragonimiatic cyst, and pneumonectomy in 1 case-tuberculosis, and decortication only was performed in 2 cases in paragonimiasis. Decortication & lung resection was carried out in 2 patients among which ruptured lung abscess 1 case and ruptured multiple blebs 1 case. There was no case of death but prognosis of the tuberculosis may be poor because of far advanced bilateral and active pulmonary tuberculosis.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.4
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• pp.255-261
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• 2015

Soil catena can be characterized by some properties, such as drainage levels and soil textures. Characteristics of soil catena are different drainage levels from a summit to the direction of gravity and similar soil textures. Therefore this study was performed GIS (Geographic information system) and statistical analyses using perimeters from soil series in order to characterize quantitatively and objectively soil distributional properties in Korea. The total of 16 soil series from representative granite and granite gneiss originated soils were selected among inland soils from detailed soil maps (1:25,000 scale) in Rural Development Administration (RDA) and analyzed. After the detailed soil maps were merged by soil series unit, perimeters were measured from one soil series to neighboring soil series using functions of table join, merge, dissolve, buffer, and clip in ArcGIS (10.1). The covering ratio of each soil series unit was calculated from neighboring perimeters by soil series and applied to clustering analysis. Soils that were analyzed were the total of 16 soil series; 7 of sandy loam and 9 of clay loam. As a result, analyzed soil series adjoined complicatedly such as Hyocheon series adjoined 26 series and Jisan did 276 series. The results of the clustering analysis showed that soils were clustered by soil textures except a few soil series. This study applied only one property that was a length of neighboring soil series to GIS and statistical analyses. These results were compared to existing soil groups that were classified by new-soil taxonomy, texture, soil type and drainage level. It showed that these analyses can provide soil characteristics by soil texture. Based on this study, there is a need to investigate further objectively and quantitatively in statistical analyses of soil series.

• Journal of the Korean GEO-environmental Society
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• v.12 no.2
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• pp.15-22
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• 2011

In this study, the effect of surface coating on iron-sulfide mineral for preventing the product acid mine drainage(AMD) was progressed by oxidation process of sulfide minerals abandoned mine Area. Three abandoned mines, Yongdong coal mine, Sil Lim mine, and Il Koang mine were selected as a sulfide mineral resource due to higher contamination rate. Six coating agents, apatite, limestone, mangnite, dolomite, bentonite, and cement were used for preventing the AMD with $H_2O_2$ and NaClO as a oxidizing agent helping for oxidizing process on sulfide minerals. Experimental results showed that sulfide mineral surface was coated effectively. Cement has a higher ability of preventing AMD when the ratio of cement to mineralis 1:1 and experimental condition is maintaining 4Days.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.2
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• pp.85-96
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• 2022

The study is aimed to investigate the features and socio-economic background of farmland consolidation project with medium-sized paddy plot at irrigation associations during the Japanese colonial period in Korea. Most of farmland consolidation works in the 1940s was composed of independent irrigation and drainage ditches along the short side of field plot. However, the number of farm roads at farmland consolidation zone was much smaller than number of irrigation ditches to decrease reduction in farmland area. The standard field plot was medium-sized (about 20-40 ares) in Korea but small-sized (about 10 ares) in Japan in this period. As the result of farmland consolidation works, the unit water requirement was increased to 0.0035 m³/s/ha, and the unit area drainage discharge was over 2.0 m³/s/km² in many cases. The farmland consolidation with medium-sized plot have been spread under the colonial landlord system, where major landlords occupied a large share of farmland and managed corporate farming to gain more benefit. The reasons for spread of farmland consolidation with medium-sized plot may be as follows: high net profit ratio, an increase in land price, and labor savings in rice farming. The farmland consolidation with medium-sized plot in the colonial period showed intermediate features between the farm consolidation with small-sized plot for an increase in land productivity in Japan and the farm consolidation with medium-sized plot for an increase in labor productivity after the 1960s.

• Korean Journal of Radiology
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• v.22 no.3
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• pp.376-383
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• 2021

Objective: To assess the safety and efficacy of lymphopseudoaneurysm (LPA) glue (n-butyl cyanoacrylate [NBCA]) embolization in the management of chylous ascites after retroperitoneal surgery. Materials and Methods: A retrospective analysis from January 2014 to October 2018 was performed in six patients (4 females and 2 males; mean age, 45.3 ± 14.2 years; range, 26-61 years) who underwent LPA embolization for chylous ascites developing after retroperitoneal surgery involving the perirenal space (four donor nephrectomies, one partial nephrectomy, and one retroperitoneal lymphadenectomy). After placing a percutaneous drainage catheter into the LPA or adjacent lymphocele, embolization was performed by filling the LPA itself with a mixture of glue and Lipiodol (Guerbet). Results: Daily drainage from percutaneously placed drains exceeded 300 mL/day despite medical and surgical treatment (volume: mean, 1173 ± 1098 mL; range, 305-2800 mL). Intranodal lymphangiography was performed in four of the six patients and revealed leakage in 2 patients. Percutaneous embolization of the LPA was successful in all patients using an NBCA and Lipiodol mixture in a ratio of 1:1-1:2 (volume: mean, 4.3 ± 1.1 mL; range, 3-6 mL). Chylous ascites was resolved and the drainage catheter was removed in all patients within 4 days after the procedure (mean, 2.0 ± 1.8 days; range, 0-4 days). No procedure-related complications or recurrence of chylous ascites occurred during a mean follow-up period of 37.3 months (range, 21.1-48.4 months). Conclusion: Glue embolization of LPA has the potential to be a feasible and effective treatment method for the management of chylous ascites after retroperitoneal surgery.