• Journal of Korea Water Resources Association
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• v.45 no.8
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• pp.839-851
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• 2012

When we evaluate the water supply capacity of a river basin, it is a common practice to gradually increase the water demand and check if the water demands are met. This practice is not only used in the simulation approach, but also in the optimization approach. However, this trial and error approach is a tedious task. Hence, we propose a two-phase method. In the first phase, by assuming that the decision maker has complete information on inflow data, we use a goal programming model that can generate the maximum water supply capacity at one time. In the second phase, we simulate the real-time operation for the critical period by utilizing the water supply capacity given by the goal programming model under the condition that there is no foresight of inflow. We applied the two-phase method to the Geum-River basin, where multi-purpose weirs were newly constructed. By comparing the results of the goal programming model with those of the real-time simulation model we could comprehend and estimate the effect of perfect inflow data on the water supply capacity.

• Journal of Korean Society of Transportation
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• v.26 no.2
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• pp.81-88
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• 2008

This paper presents the travel demand estimation using interval estimation methods during the trip generation stage, and then followed the other three stages of the four stage trip estimation. We have used real data of Dae-jun City. To estimate travel demand using the interval estimation method, a reliability level was set to 95% by a upper bound value, a middle value and a lower bound value. The four stage traffic demand analysis procedure was equally applied and finally interval traffic was estimated. The result showed a difference between maximum values and middle values depending on the destination during the trip generation stage. It depends on an explanation ability of regression analysis. Most of interval estimation ratio resulted in the traffic assignment stage showed ${\pm}5{\sim}18%$ difference on the average and ${\pm}30{\sim}50%$ at the most.

• Environmental Analysis Health and Toxicology
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• v.20 no.2 s.49
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• pp.109-121
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• 2005

A chemical ranking and scoring (CRS-Korea) system was developed and proposed to use as the first step to prioritize the toxic chemicals for the purpose of monitoring and detailed risk assessment that might follow as necessary. The CRS-Korea system takes a basic concept of risk assessment (both human health risk and ecological risk) in that risk score is determined by the product of toxicity score and exposure score. Included in the toxicity category are acute toxicity, chronic/sub -chronic toxicity, carcinogenicity, and other toxicity. The exposure category consists of quantity released to the environment, bioconcentration, and persistence. A consistent scheme and a comprehensive chemical data base are offered in the CRS-Korea system to calculate a score for the each component in the two categories by using specific physicochemical, fate, and toxic properties and the quantity of the chemical used. The toxicity score is obtained by adding up all the individual scores for the components in the toxicity category. The exposure score is determined by multiplication of the score of the quantity released with the sum of persistent score and bioconcentration score. Equal weight is given to the toxicity score and the exposure score. As the CRS-Korea system was applied to identify 50 national priority chemicals, it was found that significant data gap exists on toxicity and fate properties and that the uncertainty associated with estimating the quantify released to the environment is notably high. The proposed CRS system is only a screening tool in the first step toward the priority setting and should be used with expert judgement and other considerations necessary.

• Journal of Distribution Science
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• v.13 no.11
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• pp.47-58
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• 2015

Purpose - This study aims to seek determinants of department store sales commission rates under consignment contracts based on transaction cost theory, the power-dependence view, and the resource-based view. A consignment contract is a unique contract where the retailer, over a given period, takes possession of goods owned by a supplier, promotes the sales of these goods, and receives a profit share from their sales. Under this contract, the supplier owns the goods until they are sold. In department stores in South Korea, over 70% of overall sales comes through consignment contracts. In other words, this is the most popular contract agreement between large retailers and vendors in South Korea. Consignment contracts yield high profits to department stores with minimal sales uncertainty, stock cost, and marketing investment. Many suppliers believe the consignment contract commission rates are too high. However, department stores disagree. They state that the commissions are not high as they generate new value for the suppliers by accumulating up-to-date merchandise and supporting various marketing programs on their behalf. Recently, consignment contracts have been critically examined and scrutinized by politicians, mass media, and the public of Korea. This study further intends to derive implications reflecting both buyer and seller perspectives as well as offer insights to policy makers in making appropriate decisions. Research design, data, and methodology - To verify the proposed research model and test hypotheses, the authors selected 164 suppliers, which currently have relationships with department stores. This study carefully investigated the reliability, content validity, convergent validity, and discriminant validity of the proposed model. The data were analyzed using SPSS 18.0 and AMOS structural equation modeling program Results - For the transaction cost theory and the power-dependence view, the results indicated that product diversity and demand volatility had a positive impact on the sales dependence on a department store. Dependence in turn had a positive effect on the sales commission under the consignment contract. Based on the resource-based view, the department store's marketing capability, the supplier's perception toward merchandising, and supporting activities could enhance the department store's channel leadership in the buyer-seller relationship. Subsequently, the channel leadership had a positive effect on the sales commission. However, product complexity had no relationship with department store dependence. Conclusions - This is the first empirical research that investigates the determinants of sales commissions under consignment contracts in the domestic retail industry. This study reveals several theoretical and practical implications for both marketing scholars and marketers. In terms of theoretical implication, this study integrated and enlarged certain theoretical background, such as transaction cost theory, the power-dependence view, and the resource-based view, to explain the determinants of sales commissions under consignment contracts that include sales revenue. From a business management viewpoint, this research offers useful insights for policy makers by applying two different perspectives, both the manufacturer and the retailer, in terms of the sales commission issue under a consignment contract.

• Journal of Wetlands Research
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• v.19 no.4
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• pp.515-522
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• 2017

This study investigated the runoff characteristics containing NPS pollutants in urban areas and estimated the optimal number of storm events to be monitored. 13 residential areas, 8 commercial areas, 9 transportation areas and 11 industrial areas were selected to be monitored located in urban areas. Monitoring was performed from 2008 to 2016 with a total of 632 rainfall events. As a result, it was found that commercial area needs priority NPS management compared to other landuses because the commercial area has high runoff coefficient and NPS pollutant EMC compared with other landuses. The annual monitoring frequency for each landuse was estimated to be 11 to 14 times for industrial area, 12 to 14 times for transportation area, 11 to 13 times for commercial area and 22 to 25 times for residential area. Even with the use of accumulated monitoring data for several years, there is still high probability of uncertainty due to high error in some pollutant items, and it is necessary to establish monitoring know-how and data accumulation to reduce errors by continuous monitoring.

• Journal of Korea Water Resources Association
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• v.53 no.4
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• pp.293-301
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• 2020

This study determined appropriate threshold level (cumulative period and percentage) of precipitation for drought management in dam basin. The 5 dam basins were selected, the daily dam storage level and daily precipitation data were collected. MAP (Mean Areal Precipitation was calculated by using Thiessen polygon method, and MAP were converted to accumulated values for 6 cumulative periods (30-, 60-, 90-, 180-, 270-, and 360-day). The correlation coefficient and ratio of variation coefficient between storage level and MAP for 6 cumulative periods were used to determine the appropriate cumulative period. Correlation of cumulative precipitation below 90-day was low, and that of 270-day was high. Correlation was high when the past precipitation during the flood period was included within the cumulative period. The ratio of variation coefficient was higher for the shorter cumulative period and lower for the longer in all dam, and that of 270-day precipitation was closed to 1.0 in every month. ROC (Receiver Operating Characteristics) analysis with TLWSA (Threshold Line of Water Supply Adjustment) was used to determine the percentage of precipitation shortages. It is showed that the percentage of 270-day cumulative precipitation on Boryung dam and other 4-dam were less than 90% and 80% as threshold level respectively, when the storage was below the attention level. The relationship between storage and percentage of dam outflow and precipitation were analyzed to evaluate the impact of artificial dam operations on drought analysis, and the magnitude of dam outflow caused uncertainty in the analysis between precipitation and storage data. It is concluded that threshold level should be considered for dam drought analysis using based on precipitation.

• Korean Journal of Construction Engineering and Management
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• v.10 no.1
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• pp.114-125
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• 2009

In this study, a design value analysis technique that considered stochastic LCC and stochastic performance evaluation was proposed, and by introducing the concept of reliability analysis, a decision making that secured reliability was supported. The results of this study, which was carried out according to the above objectives and methods, are summarized as follows: 1) The design value analysis procedures and value state function, improved in order to carry out a reliable analysis when evaluating alternate proposals that were extracted after the function definition was complete, were formalized, and in order to secure consistency and efficiency for value evaluation procedures, an evaluation index scheme was proposed; 2) Database collection and analysis were done for a bridge's LCC analysis. As for the collection scope of data, literature of previous research done on a bridge's LCC analysis was used as the basis for analysis, and for securing reliability regarding analysis results and dealing with uncertainty of collected data, the MCS technique was applied; 3) Weights and evaluation ranks for performance evaluation of each of the alternate proposals, as well as LCC analysis model, analysis period, discount rate, user expense, safety inspection and safety diagnosis expense conditions for LCC analysis were proposed. Lastly, a feasibility study was done and conclusion was made about "OO grand bridge and connecting road construction work execution design" project centered on value analysis execution case.

• Journal of the Korean Geotechnical Society
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• v.15 no.5
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• pp.217-228
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• 1999

The three methods of analysis (i) REV(representative elemental volume), (ii) non-REV and (iii) joint network analysis are introduced in this paper to analyze the groundwater flow in jointed rock mass and the inflow into underground excavations. The results from those methods are compared one another to reveal their characteristics by varying the number of joints and the diameter of the opening. The pre-processor, the so-called sequential analysis, is introduced to predict the equivalent hydraulic conductivity of a jointed rock mass having a number of intersecting joints. Using the finite element mesh, joint map and sequential analysis, the equivalent hydraulic conductivities are calculated for all 445 elements. The hydraulic inhomogeneity and the determination of the representative properties of jointed rock masses are discussed. In the REV analysis where the entire rock mass is homogenized through the representative properties, the inflow is increased regularly and consistently by increasing the joint density, the opening size and the conductivity contrast value. Though the non-REV analysis showed irregular variation of the inflow due to the local inhomogeneity allowed to individual elements, the inflow approached the REV results as the characteristic length increases. The joint network analysis showed the most sensitive reaction to the joint density, the opening size and the presence of the network crossing the opening. The reliability of the network analysis depends on the geometric data of individual joints. In view of the limited field data on joint geometry and possible uncertainty the REV and non-REV methods are considered more practical and rational than the joint network analysis.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.307-307
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• 2017

There is a growing need to understand how local, farm household, and elementary units are responding to changes in agricultural conditions due to increased internal and external agrarian conditions and increased uncertainty in agricultural management due to increasing FTA and climate change. Therefore, we analyze dynamics of changes through more detailed and precise gathering of information related to agricultural products and DB, and by analyzing the satisfaction level of the first year panel survey by constructing a producer panel for utilization in agricultural research and policy. A total of 500 farmers in the producer panel who mainly grow rice, garlic, onion, strawberry, apple were collected through questionnaires. The actual analysis used data from a total of 393 farm households, including 82 farms of rice, 51 farms of apple, 100 farms of garlic, 88 farms of onion and 72 farmhouses of strawberry. The distribution by age was similar to the distribution of rural ages in Korea, with 2.8% under 30s, 17.6% in 40s, 32.4% in 50s, 37.5% in 60s and 9.7% in 70s. Panel happiness and rural life satisfaction were examined using the 7 - point Likert scale and the analysis method was one - way ANOVA. The results showed that the happiness of garlic and strawberry cultivator was significantly higher than that of rice and onion cultivator. However, the satisfaction of rural life did not show any difference among the cultivars. As a result of difference verification about Agricultural Outlook and Crop-specific Outlook after 5 years, there was no difference between the crops in terms of prospects for Korean agriculture after five years, but a survey of industrial prospects for crops after five years showed that the rice growers have a significantly negative outlook compared to garlic, onion and strawberry growers, and garlic and onion growers have a more positive outlook than rice and apple growers As a result of verifying whether there is a difference in ages between the agricultural prospects and the industrial prospects by crops after 5 years, there was no difference between the ages of prospects for Korean agriculture after 5 years, However, in the survey on industrial prospects by crops after 5 years, 40s were more positive than 60s.

• Journal of Hospice and Palliative Care
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• v.14 no.1
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• pp.34-41
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• 2011

Purpose: The purpose of this study was to analyze the reason to select complementary and alternative therapy for terminally ill cancer patients. Methods: The data were collected from 21 terminal cancer patients and families through the in-depth interview. Data analysis were performed by the Colaizzi's phenomenological method (1976). Results: The reason to select complementary and alternative therapy for terminal cancer patients and families was then categorized with 4 elements; Awareness of limitations in contemporary medical treatments, Belief in effectiveness of the CAM, Satisfaction with emotional needs of family members, and Disbelief due to negative attitudes of physicians. The result indicated the following 9 themes expectation for a complete cure, uncertainty in hospital treatments, complementary method for management of side effect of chemotherapy, alleviation of symptoms and life-sustaining, fear for side effects of cancer treatments, belief in earned information, referrals by other, responsibility of family, and dissatisfaction with negatine attitudes of physicians. Conclusion: Physicians should provide a sufficient explanation and try to effectively communicate with clients about hospice and palliative service and the CAM. We strongly realized that concerns about patients' best care and satisfactions with family's needs should be understood.