• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.4
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• pp.87-96
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• 2019

The objective of this study was to develop a general inundation modeling technique considering the effect of drainage delay in the paddy field districts. In most studies, farmland inundation simulations have been conducted using previously developed watershed models. However, the water cycle in the paddy fields has a different structure from that of the general watershed, and the effect of the drainage delay should be considered. In this study, the drainage delay algorithm was developed using water balance equation, and the inundation modeling was performed for inundation-prone paddy fields located near Doowol stream. As a result, the depth of inundation was 43.1 cm and 45.2 cm, respectively, due to the 100-year and 200-year frequency rainfall. With the operation of drainage pump ($0.1m^3/s$), inundation depths decreased by 5.8 cm and 6.0 cm, respectively, and inundation time reduced by 20 hours and 21 hours, respectively for the 100-year and 200-year frequency rainfall. The result showed that the general inundation modeling technique developed in this study could reflect the effect of drainage delay due to the rise of external water level and the flooding reduction effect by operation of drainage pump. The results of this study are expected to be useful to establish measures for damage caused by farmland inundation.

• Journal of applied mathematics & informatics
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• v.13 no.1_2
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• pp.165-182
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• 2003

Sufficient conditions for oscillation of all solutions of a class of second-order quasilinear delay differential equations with fixed moments of impulse effect are found.

• Explosives and Blasting
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• v.39 no.4
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• pp.12-21
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• 2021

In this study, a series of FEM numerical analyses was conducted to compare the resistance performance of concrete drainage protection facility to blast vibration. Two different types of ㅁ-shaped protection facility, which are suggested in the study, were compared to the traditional ㄷ-shaped one. In the analyses, the vibration resistances of the three protection facilities were evaluated under the varying conditions of the standoff distance from the explosion and charge weight per delay. As a result, it was found that the two proposed types of drainage protection facilities are superior to the traditional one in the vibration reduction performance.

• Journal of Soil and Groundwater Environment
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• v.16 no.3
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• pp.17-27
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• 2011

Recently, a physically based model of water-table fluctuation due to precipitation is developed based on aquifer water balance model. In the model, it was assumed that the water infiltration into ground surface is advection dominant and immediately reaches to water-table. The assumption may be suited for the sites where the water-table is shallow and/or the permeability of the unsaturated zone is high. However, there are more cases where the model is not directly applicable due to thick and low permeable unsaturated zone. For the low permeability unsaturated zone, the pattern of water flux passing through unsaturated zone is diffusive as well as advective. In this study, to improve the previously developed water-table fluctuation model, we combined the delayed drainage model, which has long been used in well hydraulics, to the water-table fluctuation model. To test the validity of the development, we apply the developed model to 5 different domestic sites. The model parameters are calibrated based on the groundwater hydrograph and the precipitation time series, and the correlation analyses among the parameters are pursued. The overall analyses on the delineated model parameters indicate that the delayed drainage parameters or delay index used in the developed model are able to reveal drainage information in the unsaturated zones.

• Journal of Chest Surgery
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• v.24 no.3
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• pp.306-309
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• 1991

Esophageal perforation by a ingested coins is a rare but usually life threatening complication, particularly if there is a delay in their removal. We report a case of esophageal perforation which occurred in a 4-year-old child after ingestion of a coin. The coin was removed through a left cervical esophagostomy approach. A gastrograffin study of the esophagus, performed four days after surgery, revealed the fistula had reopened. The wound was reexplored and the fistula was closed again with some debridement. In spite of the procedure, there had been continuous drainage of the saliva through the cervical fistula of esophagus. However within three weeks of conservative management, aided by a local drainage and hyperalimentation, the fistula of the esophagus was closed spontaneously.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.4
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• pp.280-285
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• 2012

From the standpoint of general guidelines of a dentist, the following conditions should be considered before replanting a permanent tooth. The avulsed tooth should be without advanced periodontal disease. The alveolar socket should be reasonably intact in order to provide a seat for the avulsed tooth. The extra-alveolar period should be considered, i.e. periods exceeding. 2 hours are usually associated with marked root resorption. But, the above mentioned regulations are often difficult to keep in the actual situation of the medical emergency room, owing it to the delay of primary medical care in multiple trauma patients. The successful cases have been reported with minimal root resorption in the long-term periods, in spite of extra-alveolar periods of several hours and combined alveolar bone fracture. This is a case report regarding the effect of endodontic drainage in delayed replantation after a prolonged extra-alveolar period of the avulsed teeth with alveolar bone fracture.

• Journal of the Korean GEO-environmental Society
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• v.13 no.3
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• pp.77-83
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• 2012

The most of horizontal drainages, which is composed of the aggregates made of sand and crushed stone, are used to improve the soft ground. However, where the aggregates are used as the horizontal drainage, it often brings about the delay of consolidation. For this reason, the horizontal drain pipe system is applied to properly improve the soft ground using a drainage pipe instead of horizontal drainage. This system is direct drain method for disappearing the excess porewater pressure which is caused by placing of fill on the soft ground. The large-scale field test was conducted in order to evaluate the applicability and constructability of the horizontal drain pipe system. The settlement characteristics of improved ground with horizontal drain pipe system was observed. It is also compared to the conventional soft ground improvement method to confirm its effectiveness.

• Journal of the Korean Geotechnical Society
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• v.21 no.5
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• pp.225-230
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• 2005

At present, there are several problems related with sand mat which is used as a way to accelerate consolidation settlement, to act like an underground drainage layer and to increase trafficability simultaneously. First of all, the unbalance of the demand and supply of sand is one of the biggest problems, which causes not only price rise but also delay of the term of the total construction work. Secondly, the damage of ecosystem and scenery is triggered by thoughtless sand dredging or mining. So, the need that sand mat should be replaced with a new environmentally friendly material has been increased. Fiber mat may be one of the proper materials that suits the need. Therefore, we intended to compare the drainage properties of sand mat with those of fiber mat by experimental model tests. On the basis of the test results, fiber mat took shorter period of consolidation than sand mat and the amount of settlement in the farmer showed a little bit bigger than in the latter. As a conclusion, the substitutability of sand mat with fiber mat could be placed highly in view of drainage efficiency. Furthermore, when fiber mat is used, it has an advantage that spoiled soil of the construction site or nearby site can be used for the purpose of increasing trafficability in addition to a role of drainage layer.

• Advances in pediatric surgery
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• v.17 no.1
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• pp.1-14
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• 2011

Biliary atresia (BA) is an infantile cholestatic disease of progressive obliterative cholangiopathy with varying degrees of damage to both extra and intrahepatic bile ducts due to unknown causes. The diagnostic studies should be done to diagnose or exclude BA without unnecessary delay. Kasai portoenterostomy is the first choice of treatment for bile drainage from microscopic bile ductules present in the portal fibrous mass. The medical management after Kasai portoenterostomy should be done carefully to maintain bile excretion and prevent and treat complications Including cholangitis, hepatic fibrosis, portal hypertension and nutritional problem. The reported five years-survival rates after Kasai portoenterostomy range from 30 to 60 %. About 20 % of all patients undergoing Kasai portoenterostomy during infancy survive into adulthood with their native liver. Even if Kasai portoenterostomy remains as the first line of treatment In BA, liver transplantation serves as a good salvage treatment when portoenterostomy fails or liver function gradually deteriorates after initially successful establishment of bile flow, Overall 5-year survival rate in BA is about 90 % in recent series.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.6
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• pp.111-123
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• 2010

In this study, laboratory model test on utilization of recycled aggregates and crushed stone as horizontal drains to use alternative material of sand in soft ground is practiced. The coefficient of permeability of the recycled aggregates and crushed stone showed largely 1.2~5.1 times and 2.0~3.3 times greater than sand, respectively. The horizontal coefficient of permeability in case of installing the horizontal perforated drain pipe showed largely 1.9~6.8 times more than the case of not installing. The drainage distance showed 1.7~1.8 times greater than sand. When a degree of consolidation is 90 %, there is no delay of consolidation in SCP and PVD improvement sections. Therefore, it is proven that the field applicability is excellent. Also, the suitable quality management criterion is presented to make use of a horizontal drains in soft ground on the basis of analysis of the physical and environmental characteristics.