• Journal of Environmental Impact Assessment
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• v.10 no.3
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• pp.223-234
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• 2001

In this study, we conducted a survey to examine the runoff characteristics of nonpoint sources, which wash off pollutants from the surface of basin during rainfall and affect water pollution of streams. An Anyangchun basin in the region Ewiwang City was selected as a study site. The basin divided into several subbasins such as Wanggokchun, Ojeonchun, and Anyangchun based on the tributaries, which confluence to the main stream of Anyangchun. Four times of field examination had been carried out between July and August of 2000, and water quality data collected from the surveys had been analysed. The survey includes in-situ flow, DO and PH measurements in the outlet of catchment. Laboratory analysis includes BOD, TN, TP. From the result, pollutant by runoff of nonpoint sources were washed out along with stormwater in the beginning of rainfall, and flowed into streams resulted in stream pollution. In case of BOD, the load from Ojeonchun catchment, most of which included urban areas, took up 50% of the total load from the entire watershed. Thus, by the results, it is clear that runoff load by urban nonpoint sources plays an important role in the control and management of nonpoint sources for the watershed.

• Journal of Biomedical Engineering Research
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• v.37 no.2
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• pp.75-83
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• 2016

Nursing staffing is of major interest in hospital management, however, no practical method has been developed. The present study proposed a mathematical model based on the patient classification system for nursing staffing optimization. A few characteristic parameters possibly determined experimentally and/or empirically were introduced followed by systematic calculation of the required number of nurses. An essential concept of the model is the unit work load defined as the amount of nursing work performed on single patient per unit time, where the work load is defined as the number of nursing staffs multiplied by the working hours. The unit work load was considered to vary with the patient classification level as well as the working time during a day, both of which were represented by corresponding parameter values. The number of patients for each class and the number of working hours were multiplied to the unit work load, and added up to obtain the total required work load. As the next step, the averaged number of hours that a nurse could provide per day was formulated considering the degree of nursing practice experience into 3 levels. Finally, the appropriate number of nursing staffs was calculated as the total work load divided by the average working hours per nurse. The present technique has a great advantage that the number of nursing staffs to fulfill the required work load is systematically calculated once the characteristic parameters are appropriately determined, leading to instant and fast evaluation. A practical PC program was also developed to apply the present model to nursing practice.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.12
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• pp.714-722
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• 2017

The TPLMs is a system to manage the total amount of pollutants discharged from the watershed in order to achieve the target water quality of the river. In this process, the pollutant load can be classified into generation, discharge and delivery load. When using equation 2, the discharge coefficient should be 1. In case of using equation 3, it is considered that the discharge coefficient defined in the Technical Guideline should be applied. The delivery load is calculated as the product of the discharge load and the delivery ratio, and the delivery ratio is defined as the rate at which the pollutant discharged from the watershed reaches a specific point in the stream. In this study, the delivery ratio estimation method proposed by Hwang (2016) was applied to the Yonggang watershed in the Nakdong river. And the input data of QUALKO2 model was generated by using the estimated delivery ratio (equation 3) and the validation study was conducted by comparing with DRave (equation 2). As a result of the study, it is possible to use both the equation 2 and the equation 3, but it is necessary to change the methodology according to the application of the discharge coefficient.

• Korean Journal of Ecology and Environment
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• v.45 no.4
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• pp.347-355
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• 2012

In this study, non-point pollution sources in the Yeongsan river basin are analyzed; then, the priority regions (areas divided on a small scale) of management are selected for efficient water management of the Seungcheon and Jooksan reservoirs, which were constructed as one of the 4 major rivers restoration projects. The priority regions are decided by using the criteria of the excessive rate of target water quality, non-point pollution load per unit area, total TP load and down flow distance. The results of this study are as follows. The upper 10% of the priority regions for non-point pollution management includes YB15, YB05, YB10, YB24, YB14 and YB11 for the Seungcheon reservoir watershed, and YC24, YC25, YC30, YC34, YC22 and YC17 for the Jooksan reservoir watershed. However, a few regions in each of the Seungcheon and Jooksan reservoirs need to be selected in higher order, and the non-point pollution removal facilities in the regions need to be installed with respect to budget, urgent matter, and so on.

• Journal of the Korea Society of Computer and Information
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• v.13 no.2
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• pp.67-78
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• 2008

The purpose of this paper is to discuss the design and implementation of a WCBT(Web and Computer based Test). The WCBT combines the strengths of both a WBT(Web-based test) and a CBT(Computer-based test) on the basis of efficiency and stability. The current assessment system, considered an important management tool in the construction and operation of a total management system for the national technical qualification, has some unstable elements with regard to system load and stability. The proposed system's technological aspects have been tested through a basic simulation pilot program. The pilot program will be expanded to include the local Chamber of Commerce and Industry because the stability of the system was proved through its application to the real-time national technical examination of KCCI (Korea Chamber of Commerce and Industry). The WCBT system has shown great efficiency in terms of system load, and has solved frequent communication problems which have occurred through the use of foreign qualifying examinations. The server and client systems of the WCBT have been given good evaluations with regard to the convenience of their use and the management system for operators and supervisors.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.7
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• pp.67-75
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• 2005

It has been well-known that the Nonpoint Source (NPS) pollutions are the primary contributors to water quality degradation in the receiving water bodies as well as the Point Source (PS) pollutions. To develop an effective management practice for water quality improvement, pollutant loads must be first estimated. In many studies, the Numeric Integration (NI) method has been used because of its ease of application, irrespective of the total number of samples collected for each storm event. Thus, there have been needs for more accurate pollutant load estimation with a limited number of water quality samples. In this study, NI method and regression method using the USGS ESTIMATOR model were comparatively used to calculate the pollutant loads for the Wolgokri watershed, Gangwon Province. The $NO_{3}$-N, T-N, and T-P loads using NI method and ESTIMATOR model were 13.85 kg/ha, 45.92 kg/ha, and 1.887 kg/ha, and 11.93 kg/ha,43.20 kg/ha, and 1.650 kg/ha, respectively. The estimated loads using ESTIMATOR model were lower than those using NI method by $86\%$, $94\%$, and $87\%$. These discrepancies in the estimated loads using a different load estimation method could be explained in that the total number of samples were not sufficient enough for NI method. Thus, ESTIMATOR model is recommended for the frequently stream discharge and less frequently measured water quality data.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.796-802
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• 2014

South Korea is recently under serious situation in supplying electricity with enough power reserve. A single fault of power plant at a peak-load time may lead to a total blackout for whole area connected by a single electric grid and isolated from other grids. Despite of the seriousness of blackout, however, there are scarce studies with ex-ante analysis of the economic costs from blackout. In order to evocate the seriousness, we calculate the economic costs for both industrial and household sectors with using some survey data and statistical methodologies. As a result, total economic costs are 39.23 trillion KRW (35.83 trillion KRW for industrial sector, 3.40 trillion KRW for household sector).

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.6
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• pp.114-126
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• 2001

The purpose of this study is to establish the databases of pollutant sources and water quality measurement data by utilizing GIS, and making the user interface for the management of pollutant sources. Yeongsan Estuarine Lake was formed of a huge levee of 4.35 km constructed by an agricultural reclamation project. Water quality of the reservoir has been degraded gradually, which mainly attributes to increase of point and non-point source pollutant loads from the lake's watershed of 33,374.3 $\textrm{km}^2$ into it. Application of GIS to establishment of the database was researched of pint source such as domestic sewage, industrial wastewater, farm wastes, and fishery wastes, and non-pont source such as residence, rice and upland field, and forest runoffs of the watershed of the lake. NT Acr/Info and ArcView were mainly utilized for the database formation. Land use of the watershed using LANDSAT image data was analyzed for non-point source pollutant load estimation. Pollutant loads from the watershed into the reservoir were calculated using the GIS database and BOD, TN, TP load units of point and non-point sources. Total BOD, TN, TP loads into it reached approximately to 141, 715, 2,094 and 4,743 kg/day respectively. The loads can be used as input parameters for water quality predicting model of it. A user-friendly interface program was developed using Dialog Designer and Avenue Script of AcrView, which can perform spatial analysis of point and non-point sources, calculate pollutant inputs from the sources, update attribute data of them, delete and add point sources, identify locations and volumes of water treatment facilities, and examine water quality data of water sampling points.

• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.682-688
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• 2009

A plane field and a sloped field located at low-land plane and alpine areas, respectively, were monitored with respect to runoff, water quality and fertilizer uses from March to December, 2008. Runoff volume and Non-Point Source (NPS) loads were estimated and analyzed with respect to fertilizer uses. Total TN and TP loads from the sloped field were higher than those from plane field because of larger chemical uses in the alpine field than in the plane field. Organic matter load from plane field was higher than that from sloped field because more organic compost was applied to plane field than to sloped field. Event Mean Concentration (EMC) of measured water quality indices were relatively higher in both fields. Organic matter load per 1 mm rainfall were higher in plane field and TN and TP loads per 1 mm rainfall were higher in sloped field than those in respective comparing field. It was concluded that the type and application method of fertilizer could play an important role in the estimation of NPS pollution loads and the development of Best Management Practices (BMPs). However, it was recommended that long-term monitoring is necessary to better describe the relationship between fertilizer uses and water quality from agricultural fields because numerous natural and management factors other than fertilizer also affect runoff quality.

• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.792-802
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• 2009

The objective of this study is to construct the watershed management system with link of the non-point sources model and to estimate delivery ratio duration curves for various pollutants. For the total water pollution load management system, non-point source model should be performed with the study of the characteristic about non-point sources and loadings of non-point source and the allotment of pollutant in each area. In this study, daily flow rates and delivered pollutant loads of Nakdong river basin are simulated with modified TANK model and minimum variance unbiased estimator and SWAT model. Based on the simulation results, flow duration curves, load duration curves, and delivery ratio duration curves have been established. Then GIS analysis is performed to obtain several hydrological geomorphic characteristics such as watershed area, stream length, watershed slope and runoff curve number. As a result, the SWAT simulation results show good agreements in terms of discharge, BOD, TN, TP but for more exact simulation should be kept studying about variables and parameters which are needed for simulation. And as a result of the characteristic discharges, pollutants loading with the runoff and delivery ratios, non-point sources effects were higher than point sources effects in the small-scale test bed of Nakdong river basin.