• KCID journal
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• v.19 no.1
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• pp.64-76
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• 2012

Recently, it has been increased disaster of crops and agricultural facilities with climate change such as regional storm, typhoon. However agricultural facilities have unsafe design criteria of improving drainage corresponding to this change. This study has analyzed the impact that inundation area and magnitude of drainage-facility is decided based on fixed- and unfixed-duration precipitation by applying revised design criteria of drainage for climate change. The result was shown that 1-day and 2-days rainfall for 20-years return period has increased about 11.4%, 4.4% respectively by changing fixed- to unfixed duration. And the increase rate of design flood was 15.0%. The result was also shown that Inundation area was enlarged by 6.6% as well as increased inundation duration under same basic condition in designed rainfall between fixed- and unfixed-duration. According to the analysis, it is necessary for pump capacity in unfixed-duration to be increased by 70% for same effect with fixed-duration. Therefore, when computing method of probability precipitation is changed from fixed one to unfixed-duration by applying revised design criteria, there seems to be improving effect in drainage design. Because 1440-minutes rainfall for 20-years return period with unfixed-duration is more effective than 1-day rainfall for 30-years return period with fixed-duration. By applying unfixed-duration rainfall, capacity of drainage facilities need to be expanded to achieve the same effects (Inundation depth & duration) with fixed-duration rainfall. Further study is required for considering each condition of climate, topography and drainage by applying revised design criteria.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.4
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• pp.25-32
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• 2023

KDS (Korean Design Standard) for agricultural drainage is a planning standard that helps determine the appropriate capacity and type of drainage facilities. The objective of this study was to analyze the inundation of the agricultural basin considering the current design standard and the critical rainfall duration. This study used the rainfall durations of 1-48 hour, and the time distribution method with the Chicago and the modified Huff model. For the runoff model, the NRCS (Natural Resources Conservation Service) unit hydrograph method was applied, and the inundation depth and duration were analyzed using area-elevation data. From the inundation analysis using the modified Huff method with different rainfall durations, 4 hours showed the largest peak discharge, and 11 hours showed the largest inundation depth. From the comparison analysis with the current method (Chicago method with a duration of 48 hours) and the modified Huff method applying critical rainfall duration, the current method showed less peak discharge and lower inundation depth compared to the modified Huff method. From the simulation of changing values of drainage rate, the duration of 11 hours showed larger inundation depth and duration compared to the duration of 4 hours. Accordingly, the modified Huff method with the critical rainfall duration would likely be a safer design than the current method. Also, a process of choosing a design hydrograph considering the inundation depth and duration is needed to apply the critical rainfall duration. This study is expected to be helpful for the theoretical basis of the agricultural drainage design standards.

• Archives of Plastic Surgery
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• v.47 no.1
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• pp.33-41
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• 2020

Background Closed-suction drains are widely used in expander-based breast reconstruction. These drains are typically removed using a volume-based criterion. The drainage volume affects the hospital stay length and the recovery time. However, few studies have analyzed the factors that influence drainage volume after expander-based breast reconstruction. Methods We retrospectively analyzed data regarding daily drainage from patients who underwent expander-based breast reconstruction between April 2014 and January 2018 (159 patients, 176 expanders). Patient and operative factors were analyzed regarding their influence on total drainage volume and drain placement duration using univariate and multivariate analyses and analysis of variance. Results The mean total drainage volume was 1,210.77±611.44 mL. Univariate analysis showed correlations between total drainage volume and age (B=19.825, P<0.001), body weight (B=17.758, P<0.001), body mass index (B=51.817, P<0.001), and specimen weight (B=1.590, P<0.001). Diabetes history (P<0.001), expander type (P<0.001), and the surgical instrument used (P<0.001) also strongly influenced total drainage. The acellular dermal matrix type used did not affect total drainage (P=0.626). In the multivariate analysis, age (B=11.907, P=0.004), specimen weight (B=0.927, P<0.001), and expander type (B=593.728, P<0.001) were significant predictors of total drainage. Conclusions Our findings suggest that the total drainage and the duration of drain placement needed after expander-based breast reconstruction can be predicted using preoperative and intraoperative data. Patient age, specimen weight, and expander type are important predictors of drainage volume. Older patients, heavier specimens, and use of the Mentor rather than the Allergan expander corresponded to a greater total drainage volume and a longer duration of drain placement.

• Journal of Korea Water Resources Association
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• v.41 no.12
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• pp.1173-1185
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• 2008

The design methods of the road surface drainage facilities were compared for the improvement of design method. We have developed four computational design models classified by the methods to determine the duration of design rainfall and to analyze the flow of a linear drainage channel. The critical duration was determined by assuming the critical duration to be 10 minutes or by finding the duration of design storm being similar to the travel time of flow by trial and error. The flow of a linear drainage channel was analyzed as the uniform flow or the varied flow. The design models were applied to the artificial road surface drainage facilities with various channel slopes and road shoulder slopes. If the rainfall intensity of the 10 minutes duration was applied, the outlet spacing obtained from the design based on the varied flow analysis was larger than the uniform flow analysis only when the channel slope and the road shoulder slope was small. On the other hands, if the duration of design rainfall was determined by calculating the travel time, the varied flow analysis brought about larger outlet spacing than the uniform analysis for all conditions. However, the model of the critical duration concept and the varied flow analysis resulted in smaller outlet spacing than the current design method employing the rainfall of 10 minutes duration and the uniform flow analysis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.6
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• pp.531-536
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• 1994

Drainage duration before seeding and furrow depth desirable for establishment and growth in direct drill seeding of rice on puddled paddy soil were investigated. Furrow depths tested were 2, 4 and 6cm in combination with drainage duration 2, 4, and 6days. Dongjinbyeo was used and seeded on May 11, 1993. Seedling establishment were improved by longer drainage duration and by shallower furrow. Lodging occurred moderately at furrow depth of 2cm with 4 and 6days of surface drainage before seeding. This lodging might be attributable to the shallow burying of shoot below soil surface. Rice yield was highest at furrow depth of 4cm with 4days drainage before seeding. In considering seedling establishment and yield, desirable drainage duration before seeding and furrow depth might be 4days and 4cm, respectively. Cone(115g) penetration depth, dropped at 1m above soil surface, was 6 to 7cm on the date after 4days drainage before seeding.

• Journal of Korean Neurosurgical Society
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• v.46 no.3
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• pp.210-214
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• 2009

Objective : Several surgical procedures have been reported for the treatment of chronic subdural hematoma (CSDH). We compared the results of treatments for CSDH obtained from one burr-hole craniostomy with closed system drainage with or without irrigation, two burr-hole craniostomy with closed system drainage with irrigation, and small craniotomy with irrigation and closed-system drainage. Methods : Eighty-seven patients with CSDH underwent surgery at our institution from January 2004 to December 2008. Our patients were classified into three groups according to the operative procedure; group I, one burr-hole craniostomy with closed system drainage with or without irrigation (n=25), group II, two burr-hole craniostomy with closed system drainage with irrigation (n=32), and group III, small craniotomy with irrigation and closed-system drainage (n=30). Results : Age distribution, male and female ratio, Markwalder's grade on admission and at the time of discharge, size of hematoma before and after surgery, duration of operation, Hounsfield unit of hematoma before and after surgery, duration of hospital treatment, complication rate, and revision rate were categories that we compared between groups. Duration of operation and hospitalization were only two categories which were different. But, when comparing burr hole craniostomy group (group I and group II) with small craniotomy group (group III), duration of post-operative hospital treatment, complication and recurrence rate were statistically lower in small craniotomy group, even though operation time was longer. Conclusion : Such results indicate that small craniotomy with irrigation and closed-system drainage can be considered as one of the treatment options in patients with CSDH.

• Journal of Environmental Science International
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• v.9 no.3
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• pp.193-199
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• 2000

This study is carried out the analysis of the runoff characteristics for the design of the interior drainage systems by SWMM in urbanization basin. The basin analyzed in this study is Bumuh-chun basin which is located in Susung-gu of Taegu city. Huff method is used for rainfall distribution analysis. The optimal rainfall duration in Bumuh-chun basin is analyzed as about 90 minutes decided from comparison of arrival time and critical duration. Flood flow variation pattern is proposed through the comparison of the results of peak flow and peak time analyzed by SWMM about pre-urbanization and post-urbanization of Bumuh-chun basin. It is known that the variation of arrival time caused by the rapid increase of pavement rate in the upper area shows about 20∼25 minutes faster than pre- urbanization. Therefore, the management of surface water for design of water supply and drainage, and channel alteration has to considered the variation of geological factors according to urbanization.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup1
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• pp.99-107
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• 2001

Objective : Hydrocephalus and vasospasm are the common complications following subarachnoid hemorrhage (SAH). In spite of development of perioperative management and operative technique, hydrocephalus cause neurological deficit and poor prognosis. Usually CSF drainage procedure(external ventricular drainage(EVD) or shunt) is needed in hydrocephalus following SAH. The aim of this study was to investigate whether the need for shunting and the outcome after shunting in hydrocephaus following SAH can be related to the duration, daily and total amount of cerebrospinal fluid(CSF) drainage at EVD. Material and Method : IVH is one of several factors which cause hydrocephalus. In this retrospective study, firstly we investigated the incidence of IVH in total cases and frequency of IVH according to aneurysmal site and then prognosis of IVH following SAH. Among 629 patients with SAH, hydrocephalus was diagnosed by CT scan and symptoms. And then those 102 hydrocephalus following SAH were divided into two groups which were hydrocephalus with IVH group and without IVH group. In these two groups, we investigated and compared the incidence of hydrocephalus in all case, frequency of hydrocephalus according to aneurysmal site, the outcome according to H-H grade on admission and the need rate of shunt, etc. Of those hydrocephalus, 100 EVD procedures were done. The duration, daily and total amount of CSF drainage at EVD were investigated. Fifty cases expired during EVD was excluded. We analyzed whether the need rate of shunt and the final outcome after shunting can be related to IVH, the duration and daily and total amount of CSF drainage. Result : The incidence of hydrocephalus following SAH was 20%(with IVH group ; 64%, without IVH group ; 11%). As H-H grade on admission was better, the outcome of hydrocephalus was also better. The mortality rate of hydrocephalus with IVH was 64% which was higher than 40% that of hydrocephalus without IVH. The need rate of shunt in all cases of hydrocephalus following SAH was 20%, but those with IVH group excluding expired patients before shunt was 40%. This was very similar to 41% of the need rate of shunt in hydrocephalus without IVH. The total amount of CSF drainage was statistically related to the need rate of shunt(total amount : need rate of shunt/<1000cc : 15%, 1000-2000cc : 40%, >2000cc : 50%). The duration and daily amount of CSF drainage were not statistically related to the need rate of shunt, but as daily amount of CSF drainage was more and duration was longer, the need rate of shunt was increased(daily amount : need rate of shunt /<100cc : 16%, 100-200cc : 25%, >200cc : 40%//duration : need rate of shunt/<1week : 8%, 1-2weeks : 30%, >2weeks : 47%), and also the final outcome after shunting was poor. Especially the total amount of CSF drainage was significant related to the final outcome after shunting(total amount : GOS/<1000cc : I&II(3/4), 1000-2000cc : II(2/4), III(2/4), >2000cc : III&IV(6/7)). Conclusion : This study revealed that the incidence and mortality rate of hydrocephalus following SAH were influenced by IVH. So SAH associated IVH has the higher incidence of hydrocephalus and poor outcome. As the CSF drainage amount was more and duration of drainage was longer, the need rate of shunt was increased and the final outcome after shunting was poor. Especially the total amount of CSF drainage were strongly related to the need rate of shunt and the outcome after shunting.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.2
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• pp.47-55
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• 2022

The objective of this study was to analyze the effect of the duration and time distribution of probability rainfall on farmland inundation for the paddy fields in the drainage improvement project site. In this study, eight drainage improvement project sites were selected for inundation modeling. Hourly rainfall data were collected, and 20- and 30-year frequency probability rainfalls were estimated for 14 different durations. Probability rainfalls were distributed using Intensity-Duration-Frequency (IDF) and Huff time distribution methods. Design floods were calculated for 48 hr and critical duration, and IDF time distribution and Huff time distribution were used for 48 hr duration and critical duration, respectively. Inundation modeling was carried out for each study district using 48 hr and critical duration rainfalls. The result showed that six of the eight districts had a larger flood discharge using the method of applying critical duration and Huff distribution. The results of inundation depth analysis showed similar trends to those of design flood calculations. However, the inundation durations showed different tendencies from the inundation depth. The IDF time distribution is a distribution in which most of the rainfall is concentrated at the beginning of rainfall, and the theoretical background is unclear. It is considered desirable to apply critical duration and Huff time distribution to agricultural production infrastructure design standards in consideration of uniformity with other design standards such as flood calculation standard guidelines.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.1
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• pp.153-155
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• 2015

Background: The aim of this study was to establish the feasibility and efficiency of different pelvic drainage routes after laparoscopic abdominoperineal resection (LAPR) for rectal cancer by assessing short-term outcomes. Materials and Methods: Clinicopathological data of 76 patients undergoing LAPR for very low rectal cancer were reviewed retrospectively between June 2005 and June 2014. Outcomes were evaluated considering short-term results. Results: Of 76 relevant patients at our institution in the period of study, trans-perineal drainage of the pelvic cavity was performed in 17 cases. Compared with the trans-perineal group, the length of hospital stay was shorter in the trans-abdominal group, while the duration of drainage and the infection rates of the perineal wounds between two groups showed no significant differences. Conclusions: The outcomes of this study suggest that trans-abdominal drainage of pelvic cavity is a reliable and feasible procedure, the duration of drainage, infection rates and the healing rates of the perineal wounds being acceptable. Trans-abdominal drainage has a more satisfactory effect after laparoscopic abdominoperineal resection for rectal carcinoma.