• Nuclear Engineering and Technology
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• v.51 no.1
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• pp.198-206
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• 2019

A new methodology to analyze the nuclear material accountability for pyroprocessing system is developed. The $Pu-to-^{244}Cm$ ratio quantification is one of the methods for Pu accountancy in pyroprocessing. However, an uncertainty in the $Pu-to-^{244}Cm$ ratio due to the non-uniform composition in used fuel assemblies can affect the accountancy of Pu. A random variable, LOPu, is developed to analyze the probability of detection for Pu diversion of hypothetical scenarios at a pyroprocessing facility considering the uncertainty in $Pu-to-^{244}Cm$ ratio estimation. The analysis is carried out by the hypothesis testing and the event tree method. The probability of detection for diversion of 8 kg Pu is found to be less than 95% if a large size granule consisting of small size particles gets sampled for measurements. To increase the probability of detection more than 95%, first, a new Material Balance Area (MBA) structure consisting of more number of Key Measurement Points (KMPs) is designed. This multiple KMP-measurement for the MBA shows the probability of detection for 8 kg Pu diversion is greater than 96%. Increasing the granule sample number from one to ten also shows the probability of detection is greater than 95% in the most ranges for granule and powder sizes.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.752-757
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• 2009

In the last decade, many methods such as greet chamber, reservoir, or debris barrier, have been utilized to manage and prevent muddy water problem. The Vegetative Filter Strip (VFS) has been thought to be one of the most effective methods to trap sediment effectively. The VFS are usually installed at the edge of agricultural areas adjacent to stream or drainage ditches, and it has been shown that the VFS effectively removes pollutants transported with upland runoff. But, if the VFS is installed without any scientific analysis of rainfall-runoff characteristics, soil erosion, and sediment analysis, it may not reduce the sediment as much as expected. Although Soil and Water Assessment Tool (SWAT) model has been used worldwide for many hydrologic and Non-Point Source Pollution (NPSP) analysis at a watershed scale. but it has many limitations in simulating the VFS. Because it considers only 'filter strip width' when the model estimates sediment trapping efficiency, and does not consider the routing of sediment with overland flow option which is expected to maximize the sediment trapping efficiency from upper agricultural subbasin to lower spatially-explicit filter strip. Therefore, the SWAT overland flow option between landuse-subbasins with sediment routing capability was enhanced with modifications in SWAT watershed configuration and SWAT engine. The enhanced SWAT can simulate the sediment trapping efficiency of the VFS in the similar way as the desktop VFSMOD-w system does. Also it now can simulate the effects of overland flow from upper subbasin to reflect the increased runoff volume at the receiving subbasin, which is what is occurring at the field if no diversion channel is installed. In this study, the enhanced SWAT model was applied to small watershed located at Jaun-ri in South Korea to simulate diversion channel and spatially-explicit VFS. It was found that approximately sediment can be reduced by 31%, 65%, 68%, with diversion channel, the VFS, and the VFS with diversion channel, respectively.

• Journal of Korea Trade
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• v.24 no.3
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• pp.1-19
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• 2020

Purpose - This study empirically analyzes the effects of provisional anti-dumping duties levied on imports by Korea following anti-dumping investigations. An anti-dumping duty is a legal tool that countries use to impose duties on imports to offset injurious dumping. This study verifies how effective the imposition of a provisional anti-dumping duty is and whether such duties have trade chilling effects on aggregate imports. Specifically, this study examines import trade diversion from named to unnamed countries caused by the imposition of provisional anti-dumping duties. Design/methodology - This empirical analysis employs an econometric model of provisional anti-dumping measures for cases in which Korea imposed final affirmative anti-dumping measures. We construct a monthly panel dataset for each stage of anti-dumping investigation undertaken by Korea for all manufacturing industries during 1995-2013. We illustrate a stage-by-stage analysis of anti-dumping investigations from initiation, preliminary decision, imposition of provisional duty, final affirmative decision, and imposition of final affirmative duty on a monthly basis at the six-digit harmonized system code-level. Findings - For cases in which provisional duties are imposed, the reduction in imports from named countries outweighs the increase in imports from unnamed countries. The substantial reduction in imports from named countries is large enough to offset the import diversion to unnamed countries, suggesting that import diversion in investigations is limited during the investigation period. Therefore, the use of provisional anti-dumping duties in Korea is effective, providing evidence of a chilling effect on aggregate imports. Originality/value - Few studies examine the size of the effects on import trade diversion of the imposition of provisional anti-dumping duties. We contribute to the literature by disentangling separate trade effects for each phase of the anti-dumping investigation process and imposition of provisional duty.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.237-237
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• 2015

The district of Marlborough has had more than its share of river management projects over the past 150 years, each one uniquely affecting the geomorphology and flood hazard of the Wairau Plains. A major early project was to block the Opawa distributary channel at Conders Bend. The Opawa distributary channel took a third and more of Wairau River floodwaters and was a major increasing threat to Blenheim. The blocking of the Opawa required the Wairau and Lower Wairau rivers to carry greater flood flows more often. Consequently the Lower Wairau River was breaking out of its stopbanks approximately every seven years. The idea of diverting flood waters at Tuamarina by providing a direct diversion to the sea through the beach ridges was conceptualised back around the 1920s however, limits on resources and machinery meant the mission of excavating this diversion didn't become feasible until the 1960s. In 1964 a 10 m wide pilot channel was cut from the sea to Tuamarina with an initial capacity of $700m^3/s$. It was expected that floods would eventually scour this 'Wairau Diversion' to its design channel width of 150 m. This did take many more years than initially thought but after approximately 50 years with a little mechanical assistance the Wairau Diversion reached an adequate capacity. Using the power of the river to erode the channel out to its design width and depth was a brilliant idea that saved many thousands of dollars in construction costs and it is somewhat ironic that it is that very same concept that is now being used to deal with the aggradation problem that the Wairau Diversion has caused. The introduction of the Wairau Diversion did provide some flood relief to the lower reaches of the river but unfortunately as the Diversion channel was eroding and enlarging the Lower Wairau River was aggrading and reducing in capacity due to its inability to pass its sediment load with reduced flood flows. It is estimated that approximately $2,000,000m^3$ of sediment was deposited on the bed of the Lower Wairau River in the time between the Diversion's introduction in 1964 and 2010, raising the Lower Wairau's bed upwards of 1.5m in some locations. A numerical morphological model (MIKE-11 ST) was used to assess a number of options which led to the decision and resource consent to construct an erodible (fuse plug) bank at the head of the Wairau Diversion to divert more frequent scouring-flows ($+400m^3/s$)down the Lower Wairau River. Full control gates were ruled out on the grounds of expense. The initial construction of the erodible bank followed in late 2009 with the bank's level at the fuse location set to overtop and begin washing out at a combined Wairau flow of $1,400m^3/s$ which avoids berm flooding in the Lower Wairau. In the three years since the erodible bank was first constructed the Wairau River has sustained 14 events with recorded flows at Tuamarina above $1,000m^3/s$ and three of events in excess of $2,500m^3/s$. These freshes and floods have resulted in washout and rebuild of the erodible bank eight times with a combined rebuild expenditure of $80,000. Marlborough District Council's Rivers & Drainage Department maintains a regular monitoring program for the bed of the Lower Wairau River, which consists of recurrently surveying a series of standard cross sections and estimating the mean bed level (MBL) at each section as well as an overall MBL change over time. A survey was carried out just prior to the installation of the erodible bank and another survey was carried out earlier this year. The results from this latest survey show for the first time since construction of the Wairau Diversion the Lower Wairau River is enlarging. It is estimated that the entire bed of the Lower Wairau has eroded down by an overall average of 60 mm since the introduction of the erodible bank which equates to a total volume of $260,000m^3$. At a cost of $$0.30/m^3$ this represents excellent value compared to mechanical dredging which would likely be in excess of $$10/m^3$. This confirms that the idea of using the river to enlarge the channel is again working for the Wairau River system and that in time nature's "excavator" will provide a channel capacity that will continue to meet design requirements.

• Journal of Korean Society of Transportation
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• v.8 no.2
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• pp.77-97
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• 1990

Compared to modal split, the methods of forecasting traffic volumes diverted in various types of I.C.s have not been sufficiently studied. The purpose of this study is to derive a new diversion function that can represent the directional traffic volume in accordance with various geometrics of I.C.s. In general, knowing various traffic impedances and the amount of traffic production and attraction, one can estimate proper traffic volumes associated with directions by using a well-defined diversion function. This function is usually made by a series of process such as surveying directional traffic volumes on several I.C.s, analyzing with a regression method and verifying those results by statistical approaches. The function has been developed by rigorous statistical testings, mainly a regression analysis. This paper presents an effective method in planning and designing new roads, I.C.s and route choice of subway. Finally, some comparisons and improvements and suggested when one uses different types of relevant models and functions.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.223-226
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• 2003

Devices of diversion gate used at irrigation canal, as a irrigation structures of agriculture, have shown serious problems such as corrosion, defect, inconvenience of operation, etc. Accordingly, handy devices of diversion gate have been developed and then tested in the laboratory. The operating types of the prototype were a rack-and-pinion type, an improved screw type that only gate plate was moved up and down while the screw axis was unmoved, and a remote control type which can be controlled from 50m away using a remote control system. Those 3 types were developed, and the improved screw type was shown the best operation through the laboratory tests.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.11 no.1
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• pp.67-80
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• 2003

This study is performed to secure the safety of civil aviation by establishing systematic analysis ability of Flight Data Recorder. Through this study, downloading SSFDR(Solid State Flight Data Recorder) to personal computer, editing interface file, flight data numerical analysis and regulations relayed to the aircraft with carry diversion into execution are performed. In the analysis, the flight data of B747-400 model aircraft between Jeju(RKPC) and Gimpo(RKSS) was selected.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.570-577
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• 2000

In this study, using modified tracer method(Constant Rate Injection, CRI method), reaeration rates were measured in the territories of Bokha stream. In case of Kwanri stream, reaeration rates of a diversion were measured simultaneously. Propane gas and Rhodamine-WT were used as gas and dye tracer, respectively. The experimental results show that reaeration rates of the stream were ranged from 6.16 to 24.52 1/day and those of a diversion in Kwanri stream were ranged from 28.39 to 123.61 1/day. It is resulted that mean velocity of stream is a dominant factor in reaeration process and diversion significantly influence on reareation process.

• Journal of Trauma and Injury
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• v.32 no.2
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• pp.118-121
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• 2019

Percutaneous nephrostomy is relatively safe for temporary urinary diversion. However, colonic perforation due to percutaneous nephrostomy can happen with an incidence of 0.2% as reported in the English literatures. To our knowledge, this is the first case being reported as a complication following treatment for traumatic renal injury. This paper is to share our treatment approach which differs from the usual approach according to existing literatures. We report on a young man who sustained grade IV renal injury due to blunt trauma and was managed conservatively. The treatment of traumatic renal injury via urinary diversion was complicated with an iatrogenic colonic perforation. The management and subsequent treatment of this patient is discussed in this case report.

• Solar Energy
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• v.20 no.2
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• pp.67-73
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• 2000

This study represents the methodology of performance prediction for small hydro power(SHP) sites. Nine tunnel type SHP sites with diversion dam were selected and the performance characteristics were analyzed by using a developed model. Also, primary design specifications such as design flowrate, plant capacity, and operational rate were suggested and feasibility for tunnel-type SHP sites were estimated. It was found that the design flowrate was most important parameter to exploit SHP plant and the methodology developed in this study was useful tool to analyze the performance of SHP sites.