• 한국물환경학회지
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• 제25권2호
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• pp.221-226
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• 2009

We investigated the most effective cutting interval for underwater nutrient removal through cut off the emergent part of hydrophytes at artificial vegetation island (AVR) which was installed for the purpose of water quality improvement in Lake Paldang. We divided the planting area of Phragmites japonica into three parts according to the cutting intervals. The shoot height and relative growth rate of P. japonica, nutrient contents and biomass of cut off P. japonica were measured at each cutting interval. The amount of nutrients which were removed through cut off at each cutting interval was calculated. P. japonica showed full growth, 80% and 60% of full growth before first cut off at three-months, two-months and one-month cutting interval condition respectively. Three-month cutting interval condition showed the largest biomass of cut off P. japonica and one-month cutting interval condition showed the least. However the cut off P. japonica showed the highest content of nutrients at one-month cutting interval condition and the least at three-month cutting interval condition. The amount of phosphorus and nitrogen removal at two-month cutting off condition is the largest among three cutting interval conditions indicating that cut off the emergent part of P. japonica every two months is the most effective to remove the nutrients from water at AVR in eutrophic lakes.

• 환경생물
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• 제33권3호
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• pp.352-359
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• 2015

본 연구는 낙동강 본류에 서식하는 Pectinatella magnifica의 출현양상을 조사하기 위해 발생시기인 2014년 7월~11월 동안 기본 분포조사와 출현밀도가 높은 지역을 대상으로 집중조사를 실시하였다. 그 결과, 낙동강 본류 구간 내 Pectinatella magnifica의 부착기질은 인공적으로 형성된 기질에서 12.3%, 자연기질에서 87.7%로써 자연기질에서 매우 높게 확인되었으나 자연기질에 포함된 식물군락의 특정 종에 따른 선호하는 정도는 유의한 차이를 보이지 않았다. 반면 본 조사 결과에서는 고착대상으로 하는 기질의 분포 정도의 차이는 P. magnifica의 분포 차이에 영향을 미치고 있음을 보여주었다. 그러므로 태형동물이 선호하는 출현기질의 증가는 P. magnifica의 성장 및 분포에 영향을 미치는 요인 중 하나로써 작용될 것으로 사료된다.

• 한국물환경학회지
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• 제30권6호
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• pp.673-682
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• 2014

A watershed model was constructed using Hydrological Simulation Program Fortran to predict the water temperature at major tributaries of Nakdong River basin, Korea. Water temperature is one of the most fundamental indices used to determine the nature of an aquatic environment. Most processes of an aquatic environment such as saturation level of dissolved oxygen, the decay rate of organic matter, the growth rate of phytoplankton and zooplankton are affected by temperature. The heat flux to major reservoirs and tributaries was analyzed to simulate water temperature accurately using HSPF model. The annual mean heat flux of solar radiation was estimated to $150{\sim}165W/m^2$, longwave radiation to $-48{\sim}-113W/m^2$, evaporative heat loss to $-39{\sim}-115W/m^2$, sensible heat flux to $-13{\sim}-22W/m^2$, precipitation heat flux to $2{\sim}4W/m^2$, bed heat flux to $-24{\sim}22W/m^2$ respectively. The model was calibrated at major reservoir and tributaries for a three-year period (2008 to 2010). The deviation values (Dv) of water temperature ranged from -6.0 to 3.7%, Nash-Sutcliffe efficiency(NSE) of 0.88 to 0.95, root mean square error(RMSE) of $1.7{\sim}2.8^{\circ}C$. The operational water temperature forecasting results presented in this study were in good agreement with measured data and had a similar accuracy with model calibration results.

• 한국물환경학회지
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• 제30권1호
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• pp.16-24
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• 2014

A combined watershed and receiving waterbody model was developed for operational water flow forecasting of the Nakdong river. The Hydrological Simulation Program Fortran (HSPF) was used for simulating the flow rates at major tributaries. To simulate the flow dynamics in the main stream, a three-dimensional hydrodynamic model, EFDC was used with the inputs derived from the HSPF simulation. The combined models were calibrated and verified using the data measured under different hydrometeological and hydraulic conditions. The model results were generally in good agreement with the field measurements in both calibration and verification. The 7-days forecasting performance of water flows in the Nakdong river was satisfying compared with model calibration results. The forecasting results suggested that the water flow forecasting errors were primarily attributed to the uncertainties of the models, numerical weather prediction, and water release at the hydraulic structures such as upstream dams and weirs. From the results, it is concluded that the combined watershed-waterbody model could successfully simulate the water flows in the Nakdong river. Also, it is suggested that integrating real-time data and information of dam/weir operation plans into model simulation would be essential to improve forecasting reliability.

• 한국물환경학회지
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• 제34권5호
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• pp.462-469
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• 2018

There are differences in method and cycle of flow rate survey depending on purpose of the operating department. To verify and use results of flow data according to the purpose, flow data of the directly measured and tele monitoring system were compared to verify validity. Flow measurement in the Ministry of Environment is aimed at setting up a standard flow of target water quality for water quality management and securing flow data of low and normal water level seasons for water quality evaluation. In this study, correlation analysis result ($R^2$) of same time zone data by direct measurement and tele monitoring system (TMS) at Seombon D point, a unit watershed of Seomjin river, for six years ('10 ~ '15) according to implementation of Total Daily Maximum Load (TDML) was wading 0.716, boating 0.962 and on bridge 0.943, and effectiveness of measurement method was verified by characteristics of flow duration as a season of dry and low-water; normal and high water are appropriate for wading, boating, and on bridge respectively. Results revealed it is reasonable to use directly measured results using the wading and boating method for low water level and dry seasons, and TMS data for rainy seasons. It can be used important data for future policy decisions.

• 대한가정학회지
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• 제48권1호
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• pp.83-96
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• 2010

This study was conducted to derive useful predictive variations for the qualitative supply of homes to provide information to real estate venture businesses and other business owners in neighborhood amenities and significant basic information to housing suppliers and policy makers. For this purpose, a number of apartment dwellers in Seoul were surveyed to examine their housing satisfaction, difference in housing satisfaction according to variables, and any relevant correlations. In detail, 500 apartment dwellers in Seoul were surveyed from September 1, 2009 to September 20, 2009 to gather resources that were processed through SPSS 14.0 to find percentage of frequency, mean, standard deviations, t-test, ANOVA, and Duncan Multiple Ranger's Test. The following were the findings of this study: First, housing satisfaction of apartment dwellers in Seoul was above average with the highest satisfaction with neighborhood environment. Second, satisfaction with amenities was significantly affected by dweller-related variables. Gangnam dwellers were more satisfied with housing environment and community environment than Gangbuk dwellers. By age, people in 20s and 30s showed high satisfaction with housing environment. Satisfaction with community environment was high among 20s, 30s and 40s. Satisfaction with management conditions was high among 20s. Also, satisfaction was high when housing period was between 1 and 10 years. By size, dwellers in 40py or larger homes showed high satisfaction with housing environment and management conditions. Dwellers in 30py and 40py or larger homes were satisfied with community environment. By ownership, dwellers with ownership of their homes showed high satisfaction. Third, there was a significant difference in satisfaction with neighborhood and social environments according to dweller-related variables. By region, dwellers of Gangnam area showed high satisfaction with neighborhood environment. By age, people in 20s, 30s and 40s showed high satisfaction with neighborhood environment. Also, satisfaction with neighborhood environment was high when housing period was around 10 years. By size, dwellers in 30py and 40py or larger homes were satisfied with neighborhood and social environments. Fourth, there was a close correlation between satisfaction with housing environment and satisfaction with community environment, and between satisfaction with community environment and satisfaction with management conditions. Thus, most dwellers that were satisfied with one variable of housing environment showed high satisfaction with other variables.

• 한국유기농업학회지
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• 제16권3호
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• pp.259-274
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• 2008

This study was designed to analyze the possibility to enter the Chinese market aggressively by giving light on the factors which have effects on the continuous intention of Shanghai consumers to purchase environment-friendly foods, and the purchase of Korean environment-friendly foods. The objects of analysis were the 209 consumers living in Shanghai, China. As for the analysis method, the frequency, percentage, crossing analysis, $X^2$-test and logistic regression analysis were carried out, making use of SPSS PC+ 13.0. The study results are as follows. Firstly, it was identified that the decisive factors, such as good taste, health of family, freshness, food shop in a department store, international quality authentication, diversity of items and number of family members, had effects on the possibility that the consumers in Shanghai, China would purchase environment friendly foods continuously, showing the meaningful variables. Secondly, as for the decisive factors having effects on the possibility to buy Korean environment friendly foods continuously, it was identified that good taste, health of family, freshness and price cutting were the meaningful variables. Therefore, it is necessary that to set up a export promotion strategy to make the Shanghai consumers get interested in Korean environment-friendly foods and choose to buy the foods.

• 산경연구논집
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• 제7권1호
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• pp.19-25
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• 2016

Purpose - The purpose of this paper is to aim to stress the importance of doing business environment in South Korean economy. The theoretical justification is based on neo-institutional theories and new business management including Porter's Model as main justifications of state intervention due to the market failures to promote a competitive environment of doing business. Research design, data and methodology - The methods to be taken is to provide a comparative performance analysis, and offer in terms of doing business and economic freedom sub-index complemented by Korean reforms diagnostics. Results - The main results underlined the key factors explain the success of business environment in South Korea such as: a simplified registration procedures, a target tax incentives, the removal of business barriers, the improvement of legislative and regulatory framework, target reforms, property right and technical norms, good governance and the quality of institution, a role of a well-functioning legal framework, a strong competition framework, and the transparency of regulation, etc. Conclusion - A competitive environment of doing business is based on the target national strategies, appropriate reforms responding to national needs and good governance system.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1234-1239
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• 2000

KOMPSAT-1(Korea Multi-Purpose Satellite), which opened the space era in Korean peninsula, was developed from 1994 and launched successfully in December of 1999 at VAFB, USA. This paper presents a launch environment test of KOMPSAT and a short description of environment test facilities at Korea Aerospace Research Institute as well. The launch environment tests of KOMPSAT-1 satellite, such as vibration, acoustic, pyro-shock and mass properties measurement test, were performed during its system integration and test period. The participating engineers concluded that KOMPSAT-1 satellite would withstand environment during its launch period.

• 대한가정학회지
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• 제46권9호
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• pp.87-97
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• 2008

This study was conducted to develop the Home Literacy Environment Rating Scale(HLERS) and to analyze its item discrimination, reliability, and validity. The participants of this study were 438 parents whose children were three to five years old. The item discrimination, determined by comparing the highest and lowest group using Chi-square($x^2$) and Cramer's V, was found to be satisfactory. The Cronbach's $\alpha$ for internal consistency reliability was .78. Factor analysis revealed that the structure of the HLERS consisted of three factors: 'reading books,' 'reading behavior and modeling of parents' and 'literacy learning.' The concurrent validity was also identified by correlation between the HLERS and two sub-tests of EC-HOME. In conclusion, these results demonstrated that the Home Literacy Environment Rating Scale is reliable and valid to examine the home literacy environment for Korean families.