The sinking seat is the mounted seat in rear columns of recreational vehicle. The convenience of sinking seat is lower than folding seat because the paths of the containment and withdrawal are different each other. In this paper, the cam shape design model which is related recliner apparatus was introduced of the folding path of the existing manual system sinking seat. And the validity of the design variable was verified through the dynamic mechanics simulation using RecurDyn. but, the transformation-time graph of cam link joint position in RecurDyn is unstable because it is not consideration of friction.

Pick-up truck has the advantage that can transport more baggage by the deck. However, it is inconvenient to put loads by a high ground clearance values. In this paper, we proposed a corresponding method to the high ground clearance using 4-bar linkage lift mechanism of tailgate. In addition, the validity of the lift mechanism through the prototype test is verified.

본 연구에서는 일반 음식점의 주방에서 발생하는 질병자의 특성을 분석하고자 2009년부터 2011년까지 음식점 주방에서 발생한 116명 질병자의 특성을 분석하였다. 일반 음식점 주방에서 발생한 질병자는 5인 미만의 영세음식점에서 63.8%가 발생했으 며, 성별분포는 여성작업자가 66.4%로 나타났다. 연령분포는 40～50대에서 63.8%가 나 타났으며, 근속기간별 분포에서는 2～5년 미만의 작업자가 전체 질병자의 58.7%를 차 지하였고, 작업관련성질환이 86.2%로 나타났다. 일반음식점 주방에서의 질병자 특징에 관한 연구결과는 주방에서 발생하는 질병에 관한 체계적인 예방대책을 세우는데 기초 자료로 이용될 수 있을 것이다.

n-InP(001)기판과 PECVD법으로 Si3N4(200nm)막이 성장된 InP 기판사이의 direct wafer bonding을 분석하였다. 두 기판을 접촉시켰을 때 이들 사이의 결합력에 크게 영향을 주는 표면 상태를 접촉각 측정과 AFM을 통해서 분석하였다. InP 기판은 50% 불산용액으로 에칭하였을 때 접촉각이 5˚, RMS roughness는 1.54Å이었다. Si3N4는 암모니아수 용액으로 에칭하였을 때 RMS roughness가 3.11Å이었다. Inp 기판과 Si3N4/InP를 각각 50% 불산 용액과 암모니아수 용액에 에칭한 후 접촉시켰을 때 상당한 크기의 초기 겹합력을 관찰할 수 있었다. 기계적으로 결합된 시편을 580˚C-680˚C, 1시간동안 수소 분위기와 질소분우기에서 열처리하였다. SAT(Scanning Acoustic Tomography)측정으로 두 기판 사이의 결합여부를 확인하였다. shear force로 측정한 InP 기판과 Si3N4/InP사이의 결합력은 Si3N4/InP 계면의 결합력만큼 증가되었다. TEM과 AES를 이용해서 di-rect water bonding 계면과 PECVD계면을 분석하였다.

매립형 InGaAnP/InP 레이저 다이오드 제작을 위한 질량 이동 현상의 최적화에 대한 연구를 수행하였다. Double heterostructure 레이저 다이오드 구조의 1차 성장은 액상 에피 성장 장치를 이용하였으며, 메사 에칭하였다. 활성층을 [110] 방향으로 선택적으로 에칭 한 후, 액상 에피 성장 장치를 이용하여 질량 이동 현상을 발생시켜 매립형 구조를 형성시켰다. 질량 이동 현상의 임계온도는 40분간 유지시켰을 때 670˚C로 나타났으며 재현성 있게 질량 이동 현상이 발생하였다. 질량 이동 현상에 의해 성장된 층의 폭은 온도증가에 따라 약간 증가하였다.

본 연구에서는 시스토릭 어레이의 처리요소 수와 주어진 알고리즘을 처리하는 시간 두 평가기준에 대해서 최적의 시스토릭 어레이를 구현하기 위한 자동설계 소프트웨어 패케지를 개발하였다. 알고리즘의 크기에 맞는 시스토릭 어레이는 많은 처리요소를 요구하기 때문에 비효율적이므로 알고리즘을 분할하여 고정된 크기의 시스토릭 어레이로 사상시키는 방법을 이용했다. 시스토릭 어레이 설계과정에서 고려될 수 있는 여러 가지 사항들을 고려하여 처리요소의 통신패스 방향의 수를 줄이고 의존행렬의 열 벡터에서 값이 같은 열 벡터는 단일화하여 의존행렬의 크기를 줄여 발생되는 이용행렬의 수를 크게 줄였다. 따라서 기존의 Moldovan에 의한 방법보다 시스토릭 어레이를 설계하는 시간을 단축시켰으며, 처리요소의 수, 알고리즘의 수행시간, 분할밴드의 수 등을 계산하여 최적의 시스토릭 어레이를 설계했다. 작성된 프로그램에 동적 프로그래밍 알고리즘, QR분해 알고리즘과 행렬곱 알고리즘을 적용하여 각각에 대한 최적의 시스토릭 어레이를 설계하였으며 설계된 어레이의 구성을 CRT에 나타내어 어레이의 형태를 쉽게 인식할 수 있게 했다. 본 연구의 결과는 빠른 응답을 요구하는 신호 처리 및 데이터베이스 등에서 특수회로를 설계할 때 응용 될 수 있다. 그러나 본 연구에서의 시스토릭 어레이는 처리요소들이 분산되어 지역적으로 상호 연결되어 있으므로 한 처리요소가 제대로 동작하지 않으며 전체결과가 잘못된다. 따라서 몇 개의 처리 요소가 동작되지 않을 경우에도 전체 시스템이 정확하게 동작할 수 있는 폴트톨러런스 시스템의 설계가 앞으로의 고려사항이다.

Concern about water quality and pollution was heightened as contaminants flowed into the Namhan River downstream of the Chungju Dam. Thus, this study calculated the Real-Time Water Quality Index (RTWQI) using monthly average water quality monitoring data for major tributaries that require water quality control, which were obtained between 2010 and 2019. To review the applicability of the RTWQI for water quality assessment in the major tributaries of the Namhan River, it was compared with the living environment standard river. The calculated RTWQI result indicated that Bokhacheon, with 59 points, was in the “fair” grade, and this stream was identified as a tributary that preferentially requires water quality improvement as it showed a decreasing (-) tendency of RTWQI. A comparison between RTWQI and the living environment standard of T-P showed that the categories of “completely coincident” and “different by one grade” accounted for 45% of the total, and the water quality of major tributaries was assessed as low. Therefore, the RTWQI, which applies comprehensive water quality parameters and has higher reliability than assessing a single water quality parameter, was determined to be efficient for water quality assessment of the major tributaries of the Namhan River.

BAT-AEL(Best Available Techniques Associate Emission Level) is the basis for establishing permissible emission standards for the workplace. Therefore, it is necessary to formulate a regulated BAT-AEL setting methodology that is generally applicable to all relevant industries. For the BAT-AEL settings, various factors should be considered such as the pollutants item, whether the workplace is subject to integrated pollution prevention and control, whether BAT is applicable, the basic data type, the emission classification system, and the suitability of the collected data. Among these factors, it is the most important factor to establish the classification system for the emitting facilities such that the emission characteristics of an industrial facility and its pollutants can be effectively reflected. Furthermore the target of the survey workplace should adhere to the BAT guidelines, even if it is a workplace that is subject to an the integrated environmental system. Certified data (SEMS, TMS, cleanSYS, WEMS, etc.) can be used to prioritize the classification system for the emission facility and the emission levels of pollutants. However, the self-measured data, daily logs, and questionnaire data from the workplace can also be used upon agreement of the relevant TWG. The collected data should only be used only when the facility is operating normally. Data that have been determined to be outliers or inappropriate validation methods should also be excluded. The BAT-AEL can be establish by adhering to the following procedure: 1) investigate all relevant workplaces with in the industry, 2)select workplaces for integrated management, 3)Identify BAT application, 4)identify whether BAT is generally applicable, 5)establish a classification system for emitting facilities, 6)collection available data, 7)verify conformity, 8)remove of outliers, 9)prepare the BAT-AEL draft, 10)deliberate, and 11) perform the confirmation procedure.

The groundwater quality through livestock excreta survey based on “Act of the management and use of livestock excreta” was investigated by selecting sampling sites within 1 km of the farmland without considering hydrogeological units. However, these sites can be affected by various pollution sources such as chemical fertilizers and livestock excretions. Additionally, the effects of pollution sources on groundwater quality in the sites cannot be clearly distinguished from naturally occurring backgrounds. In this study, a method was developed to select the sampling sites for groundwater quality through livestock excreta survey in order to understand the effects of pollution sources especially livestock excreta. First, the concentrations of nitrate within the radius of 200 m, 300 m, 500 m and 750 m, respectively, from the farms regarded as pollution sources in hydrogeological units were compared in 2016-2017. All the nitrate concentrations at 200 - 500 m from the farms exceeded a background concentration, 13.3 mg/L. Those at 750 m and the background concentrations measured by the Ministry of Environment were comparable. Therefore, the appropriate radius was suggested as 500 m for livestock excretions survey. In this study, the areas within 500 m from the farms could be considered under the influence of livestock excretions, while those beyond 500 from the pollution sources as background in hydrogeological units. The developed method was validated by applying it to the sites selected based on both administrative divisions and watersheds for livestock excretion survey. The average densities for the developed method were 0.82 and 0.39 points/km2, respectively, which were considered as appropriate levels according to those of the European Environmental Agency.

This study aimed to assess the impact of livestock excreta discharged from an Intensive Livestock Farming Area (ILFA) on river water quality during a rainfall event. The Bangcho River, which is one of the 7 tributaries in the Cheongmi River watershed, was the study site. The Cheongmi River watershed is the second largest area for livestock excreta discharge in Korea. Our results clearly showed that, during the rainfall event, the water quality of the Bangcho River was severely deteriorated due to the COD, NH4-N, T-N, PO4-P, T-P, and heavy metals (Cu, Zn, and Mn) in the run-off from nearby farmlands, where the soil comprised composted manure and unmanaged livestock excreta. In addition, stable isotope analysis revealed that most of nitrogen (NH4-N and NO3-N) in the run-off was from the ammonium and nitrate in the livestock excreta. The values of δ15NNH4 and δ15NNO3 for the Bangcho River water sample, which was obtained from the downstream of mixing zone for run-off water, were lower than those for the run-off water. This indicates that there were other nitrogen sources upstream river in the river. It was assumed from δ15NNH4 and δ15NNO3 stable isotope analyses that these other nitrogen sources were naturally occurring soil nitrogen, nitrogen from chemical fertilizers, sewage, and livestock excreta. Therefore, the use of physicochemical characteristics and nitrogen stable isotopes in the water quality impact assessment enabled more effective analysis of nitrogen pollution from an ILFA during rainfall events.

To investigate the distribution characteristics of grain size and organic matter of surface sediments from the Nakdong-Goryeong Mid-watershed, surface sediments were collected and analyzed. The samples were collected from six sited at four different times between May 2013 and May 2014. The were analyzed for grain size, water content, ignition loss, chemical oxygen demand, total organic carbon and total nitrogen. The surface sediments were mainly composed of medium sand (mean 44.7%) and coarse sand (mean 32.8%) and became coarser in May 2014. Fine sediments at the site NG-2 were poorly sorted and positively skewed, and occur in a tributary environment that is relatively low-energy compared with the other sites. The water content at the studied sites (15.3 ~ 34.9%) averaged 20.25%, and ignition loss (0.4 ~ 5.8%) and total nitrogen (274 ~ 2493 mg/kg) averaged 1.33% and, 696 mg/kg, respectively. These values indicated that the sediments were not seriously contaminated when compared with the sediment pollution evaluation standard of the National Institute of Environmental Research. The chemical oxygen demand (mean 0.17%) was at the non-polluted level compared with United States Environmental Protection Agency sediment quality standards. The total organic carbon (mean 0.18%) at all sites except site NG-2 (lowest effect level) was the no effect level of the Ontario sediment quality guidelines. The COD/IL (0.02 ~ 0.20) and C/N (0.73 ~ 6.76) were less than 1 and 10, respectively. Organic matter in the study area produced naturally from aquatic organisms. Results of principal component analysis showed that fine sediments (very fine sand and silt) were significantly affected by organic matters (ignition loss, chemical oxygen demand, total organic carbon and total nitrogen). In addition, the highest organic matters content in the study area occurred at the site with the finest sediments (NG-2).

Multifunctional weirs constructed through the Four Major Rivers Restoration Project are operated as management water levels. The purpose of this study was to evaluate the effect of water level in the main stem on the tributary water level according to multifunctional weir operation, because the operation of multifunctional weirs for water level management influences the drainage of tributaries. In this study, water level pressure gauges were installed and spatial and temporal water quality was observed. The LOcally Weighted Scatterplot Smoothing (LOWESS) technique was applied to the Nakdong River and the Baekcheon Junction, both upstream of the Gangjeong-Goryeong weir, in order to analyze water quality trends. When considering the overall analysis and observations, it was found that the water quality forecasting point located at the Baekcheon estuary point should be transferred to the Dosung Bridge, which is located upstream of the Sunwon Bridge.

For the development of flow duration curves for the management of 41 Total Maximum Daily Load (TMDL) units of the Nakdong River basin, first, an equation for estimating daily flow rates as well as the level of correlation (correlation and determination coefficients) was extrapolated through regression analysis of discrete (Ministry of Environment) and continuous (Ministry of Land, Infrastructure and Transportation) measurement data. The equation derived from the analysis was used to estimate daily flow rates in order to develop flow duration curves for each TMDL unit. By using the equation, the annual flow duration curves and flow curves, for the entire period and for each TMDL unit of the basin, were developed to be demonstrated in this research. Standard flow rates (abundant-, ordinary-, low- and drought flows) for major flow duration periods were calculated based on the annual flow duration curves. Then, the flow rates, based on percentile ranks of exceedance probabilities (5, 25, 50, 75, and 95%), were calculated according to the flow duration curves for the entire period and are suggested in this research. These results can be used for feasibility assessment of the set values of primary and secondary standard flow rates for each river system, which are derived from complicated models. In addition, they will also be useful for the process of implementing TMDL management, including evaluation of the target level of water purity based on load duration curves.

Recently IPCC (International Panel on Climate Change, 2007) pointed out that global warming is a certain ongoing process on the earth, due to which water resources management is becoming one of the most difficult tasks with the frequent occurrences of extreme floods and droughts. In this study we made runoff predictions for several control points in the Geum River by using the watershed runoff model, SSARR (Streamflow Synthesis and Reservoir Regulation Model), with daily RCP 4.5 and RCP 8.5 scenarios for 100 year from 1st Jan 2006 to 31st Dec 2100 at the resolution of 1 km given by Climate Change Information Center. As a result of, the Geum River Basin is predicted to be a constant flow increases, and it showed a variation in the water circulation system. Thus, it was found that the different seasonality occurred.

In recent years, the United States has used the Load Duration Curve (LDC) method to identify water pollution problems, considering the size of the pollutant load in the entire stream flow condition to effectively evaluate Total Maximum Daily Loads (TMDLs). A study on the improvement of the target water quality evaluation method was carried out by comparing evaluations of two consecutive years of water quality and LDC data for 41 unit watersheds (14 main streams and 27 tributaries). As a result, the achievement rate of the target water quality evaluation method, according to current regulations, was 68-93%, and that by the LDC method was 82-93%. Evaluating the target water quality using the LDC method results in a reduction in the administrative burden and the total amount of planning as compared to the current method.

To certificate change in the geochemical characteristics of surface sediments in the main stream of the Nakdong River, surface sediments from 12 sampling sites during the first and second half year (total 24 sampling sites) were collected and analyzed for grain size, ignition loss, total organic carbon and heavy metal content. Surface sediments mainly composed of sand (coarse and medium sand) and fining changed from the first half to the second half of the year. Ignition loss, total organic carbon and heavy metals content increased in the second half of the year. Some heavy metals (Zn, Ni and Cu) were found to be at the lowest effect levels according to Ontario sediment quality guidelines. Additionally, most heavy metals were found to be at the non polluted level and level I according to USEPA sediment quality standards and National Institute of Environmental Research sediment pollution evaluation standard, respectively. The enrichment factor (< 1) and index of geoaccmulation (< 0) were non polluted in the study area. The correlation analysis results showed that ignition loss, total organic carbon and heavy metal content were highly correlated with grain size. Regarding changes in geochemical characteristics of surface sediments in the study area, grain size fine and organic matter and heavy metal content increased in the second half year. Nonetheless these results indicated pollution levels that did not adversely affect the benthos.

For areas with the diverse contamination sources, the change of 4-nitrophenol contamination and impact of potential contamination sources have been evaluated using monitoring data and a numerical model (HydroGeoSphere). The model considered several parameters including land cover, precipitation, and flow rate. And, the model has been performed to investigate the effect of decay rate of 4-nitrophenol. The results of the simulations showed that the influence on 4-nitrophenol in downstream was mainly greater than that in upstream, and the tributaries did not significantly affect the mainstream because of their low flow rates. In addition, the effect of contamination sources was simulated for each section, then the measured data were higher than the corresponding simulated data in most sections of the Geumho river. In particular, the impact of the potential contamination sources in the upstream area was much higher than that in the other area, thus more monitoring data for the upstream area is required.

This study was performed to analyze the effects of a water circulation green area plan on non-point source pollution in Gimhae South Korea. A quantitative analysis of Arc-GIS data was conducted by applying a watershed model based on Fortran to investigate the changes to direct runoff and pollution load. Results showed that prior to the implementation of the water circulation green area plan in Gimhae, direct runoff was 444.05 m3/year, total biological oxygen demand (BOD) pollution load was 21,696 kg/year, and total phosphorus (TP) pollution load was 1,743 kg/year. Implementation of the development plan was found to reduce direct runoff by 2.27%, BOD pollution load by 1.16% and TP pollution load by 0.19% annually. The reduction in direct runoff and non-point source pollution were attributed to improvements in the design of impermeable layers within the city.