• Environmental Engineering Research
• /
• 제15권1호
• /
• pp.9-14
• /
• 2010

The objective of this study was to assess the variation in the concentration of assimilable organic carbon (AOC) in a drinking water resource, and investigate the characteristics of AOC derived from algae. The seasonal change in AOC at the Kamafusa dam corresponded to changes in the algal cell number. In order to understand the relationship between AOC and algae in a water resource and water purification plant, two kinds of laboratory experiment were performed. The algal culture experiment showed that extracellular organic matter (EOM) that was released during the growth of Phormidium tenue with M-11 medium led to significant increases in the AOC concentration, but no significant variation in the AOC concentration was observed with CT medium containing a high dissolved organic carbon concentration. The chlorination experiment showed that the AOC included in EOM was not easily removed by chlorination, although the AOC included in intercellular organic matter released from the algal cells by chlorination was removed under conditions where residual chlorine was detected.

• 자원리싸이클링
• /
• 제29권1호
• /
• pp.62-69
• /
• 2020

산업단지 내 입주기업들의 제조공정에서는 미세먼지 생성 원인물질인 질산화물(NOx), 황산화물(SOx), 휘발성 유기화합물(VOCs) 등이 다양한 형태로 배출되고 있다. 본 연구에서는 효과적인 산업단지 미세먼지 저감을 위해 산재해 있는 공공데이터를 활용하여 산업단지별 특성을 분석하고 미세먼지 감축 기술과 매칭하여 미세먼지를 감축할 수 있는 최적화 감축 방안을 제시하였다. 데이터를 기반으로 한 산업단지 별 맞춤형 기술 및 설비 적용은 미세먼지 전구물질을 공정에서 사전에 감축함으로써 산업단지 미세먼지 뿐만 아니라 제조업 미세먼지 감축을 위한 효과적인 대안이 될 것이다.

• Journal of Information Processing Systems
• /
• 제17권5호
• /
• pp.918-932
• /
• 2021

Evaluation of the collaboration of the upstream and downstream enterprises in the manufacturing supply chain is important to improve their synergistic effect. From the supply chain perspective, this study establishes the evaluation model of the manufacturing enterprise collaboration on the basis of fuzzy entropy according to synergistic theory. Downstream enterprises carry out coordinated capital, business, and information flows as subsystems and research enterprises as composite systems. From the three subsystems, the collaboration evaluation index is selected as the order parameter. The compound fuzzy matter-element matrix is established by using its improved algorithm. Subordinate membership and standard deviation fuzzy matter-element matrixes are constructed. Index weight is determined using the entropy weight method. The closeness of each matter element is then calculated. Through a representative of the home appliance industry, namely, Gree Electric Appliances Inc. of Zhuhai, empirical analysis of data in 2011-2017 from the company and its upstream and downstream enterprise collaboration shows a good trend, but the coordinated development has not reached stability. Gree Electric Appliances Inc. of Zhuhai need to strengthen the synergy with upstream and downstream enterprises in terms of cash, business, and information flows to enhance competitiveness. Experimental results show that this method can provide precise suggestions for enterprises, improve the degree of collaboration, and accelerate the development and upgrading of the manufacturing industry.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2019년도 춘계학술대회
• /
• pp.543-545
• /
• 2019

미세먼지에 따른 행동 지침을 위해 AQI 지수가 개발되어 사용되고 있다. AQI 지수에 대한 정보는 일반인들도 쉽게 제공 받을 수 있으며, 이에 따라 AQI 지수를 기반으로 다양한 서비스가 제공되고 있다. 서비스가 제공됨에 따라 정확한 AQI 지수의 예측이 필요하다. 본 논문에서는 미세먼지의 AQI 지수를 예측하기 위해 순환 신경망을 이용하여 분류 모델의 설계를 진행한다. 설계된 모델의 평가를 위해 실제 미세먼지와 예측치의 AQI 지수를 비교한다.

• 한국수소및신에너지학회논문집
• /
• 제31권6호
• /
• pp.546-552
• /
• 2020

In this study, optimization research was conducted through statistical analysis with the aim of maximizing the efficiency of organic matter reduction and hydrogen production by applying electrolysis process at sewage treatment plant. Statistical analysis and optimal operating conditions of organic matter removal efficiency and H2 generation, which varied with various conditions in the electrolysis process, were derived using response surface methodology. As a result, 1,268 μS/cm of conductivity, 350 A current, and pH 3.2 was found to be the optimum condition to reach the desired value as 38% of organic matter reduction and 2.58 L/min of H2 production. The experiment also determined that the optimization study was reliable. Base on this study, it was confirmed that the removal of organic matter and hydrogen production could be stably by applying the electrolysis process in the sewage treatment plant.

• 한국물환경학회지
• /
• 제27권1호
• /
• pp.88-97
• /
• 2011

To identify the inflow and outflow characteristics of allchthonous organic matters and examine the change of allochthonous organic matter load pattern due to the climate change, we investigated the temporal variations of DOC and POC concentrations within inflow water and dam discharge water and spatio-temporal distribution of POM within the lake water in Lake Soyang which is the largest dam reservoir in Korea in 2006. Most of allochthonous DOC flowed into the lake water during initial rain and was not affected by the amount of precipitation, whereas most of allochthonous POC flowed into during concentrated heavy rain and the concentration of POC was significantly associated with the amount of inflow water and precipitation. Calculated annual allochthonous organic matter loads in Lake Soyang from 2003 to 2006 using the regression equation between the amount of inflow water and the concentration of POC indicate allochthonous organic matter loads are mainly affected by total influx and extreme influx of inflow water. The spatio-temporal distribution of POM indicated allochthonous organic matter of inflow river during flood period in July transported from upper part to middle and lower part of the lake a month later respectively along the middle layer of water column in Lake Soyang.

• 천문학회보
• /
• 제44권2호
• /
• pp.73.4-73.4
• /
• 2019

Most of the galaxy mass is known to be occupied by dark matter. However, it is difficult to directly measure the mass and distribution of dark matter in a galaxy. Recently, the velocity dispersion of the stellar population in a galaxy's center has been suggested as a possible probe of the mass of the dark matter halo. In this study, we test and verify this hypothesis using the kinematics of the satellite galaxies of isolated galaxies. We use the Friends-of-Friends (FoF)algorithm to build a catalog of primary galaxies and their satellite galaxies from the Sloan Digital Sky Survey (SDSS) DR 12. We calculate the dynamical mass of the primary galaxies from the velocity dispersion of their satellite galaxies. We then investigate the correlation between the dynamical mass and the central velocity dispersion of the primary galaxies. The stellar velocity dispersion of the central host galaxies has a strong linear correlation with the velocity dispersion of their satellite galaxies. Also, the stellar velocity dispersion of the central galaxy is strongly correlated with the dynamical mass of the galaxy, which can be described as a power law. The results of this study show that the central velocity dispersion of the primary galaxies is a good proxy for tracing the mass of dark matter halo.

• 천문학회보
• /
• 제45권1호
• /
• pp.34.1-34.1
• /
• 2020

The recent discovery of diffuse dwarf galaxies that are deficient in dark matter appears to challenge the current paradigm of structure formation in our Universe. We describe the numerical experiments to determine if the so-called dark matter deficient galaxies (DMDGs) could be produced when two gas-rich, dwarf-sized galaxies collide with a high relative velocity of ~ 300km/s. Using idealized high-resolution simulations with both mesh-based and particle-based gravito-hydrodynamics codes, we find that DMDGs can form as high-velocity galaxy collisions separate dark matter from the warm disk gas which subsequently is compressed by shock and tidal interaction to form stars. Then using a large simulated universe ILLUSTRISTNG, we discover a number of high-velocity galaxy collision events in which DMDGs are expected to form. However, we did not find evidence that these types of collisions actually produced DMDGs in the ILLUSTRISTNG100-1 run. We argue that the resolution of the numerical experiment is critical to realize the "collision-induced" DMDG formation scenario. Our results demonstrate one of many routes in which galaxies could form with unconventional dark matter fractions.

• 한국자기학회:학술대회 개요집
• /
• 한국자기학회 2006년도 동계학술연구발표회 및 자성 스핀트로닉스 국제학술대회
• /
• pp.8-8
• /
• 2006

• 한국토양비료학회지
• /
• 제44권2호
• /
• pp.303-305
• /
• 2011

A study of different levels of Nutrition Elements and the chemical properties of the soil was conducted to determine the yield performance of potato. Application of sulfur, potassium, and Magnesium significantly affected final height, dry matter content, and crispiness of potato. The final pH, organo-nitrogen, phosphorus, potassium, and magnesium content in the soil were significantly affected by S-K-Mg application.