• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.290_291
• /
• 2009

우리나라는 냉방부하로 인해 여름철에 연중 전력소모량이 가장 많다. 이때에는 전력설비의 여유도는 가장 낮아져서 전력계통의 취약성이 가장 높아진다. 전기사업자는 송변전설비 신 증설, 발전설비 준공 시기를 여름철 전에 완료하여 최대전력 발생에 대한 준비를 한다. 전력거래소는 여름철을 기준으로 신규로 운영되는 송변전설비 및 발전 설비를 고려하여 전력계통의 안정운영 방안을 수립 한다. 이때 수립된 운영방안과 전력계통의 구성은 향후 1년 동안 우리나라 전력계통의 기본 틀이 된다. 본 논문은 2009년 여름철 최대부하에 대비하여 수립한 전력계통 안정 운영 방안을 기술하고자 한다. 주로 전년도와 비교하여 올해의 설비 변동내용 및 계통변화 내용, 상정고장 발생에 대한 전압안정도 및 과부하를 해소하기 위한 방안, 송전제약 검토결과 등을 소개할 것이다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2010.11a
• /
• pp.1694-1697
• /
• 2010

지능형 빌딩 시스템은 빌딩을 운영하는 다양한 단위시스템 정보를 통합하여 빌딩 거주자에게 쾌적하고, 안전한 생활을 할 수 있도록 운영하는 시스템을 말한다. 하드웨어적인 방법은 단위시스템에 비례하게 비용이 증가하는 단점이 있다. 소프트웨어적인 방법은 하나의 서버에서 정보를 수집하기 때문에 단위시스템에 통신량 증가로 인한 오류가 발생하면 전체 시스템에 영향을 미치는 단점을 가지고 있다. 본 논문에서는 소프트웨어적인 방법의 단점을 개선하기 위해서 부하 및 오류를 격리화할 수 있는 가상화를 이용하여 통합 관리 시스템과 인터페이스 관리 시스템으로 운영한다. 시스템의 구조는 통합 관리 모듈, 가상 관리 모듈, 구성 관리 모듈, 그리고 단위시스템 관리 모듈로 분리되며 제안 시스템을 사용함으로써 인터페이스 관리 시스템에서 발생하는 오류 및 부하로 인한 전체 시스템 오류를 축소시킬 수 있다.

• Korean Journal of Environmental Agriculture
• /
• v.18 no.1
• /
• pp.70-76
• /
• 1999

Since high concentrations of N, P, and organic C cause the excessive eutrophication in water systems, the control of nutrient export from agricultural nonpoint sources has become important. This study was conducted to estimate discharges of N, P, and organic C from a small agricultural watershed of the upper Imgo stream in Youngchun, Kyongbuk. Of the total area(1.420ha), 25% was agricultural land including paddy, upland and orchards and most of the remainder was forest. The resident population in the watershed was 194 in 80 households and relatively small numbers of livestocks including cow were raised. Mean concentrations of nutrients in the stream water were 4.95, 0.80, 6.72, 0.07 and 2.52mg/L for $NO_3-N$, $NH_4-N$, Total N, Total P and COD respectively. Annual discharges in 1997 were 28,991kg of $NO_3-N$. 3,010kg of $NH_4-N$, 37,006kg of Total N. 590kg of Total P, and 29,138kg of COD. There was a strong positive relationship between stream flow and precipitation, and also most of the nutrient discharges occurred in the rainy season (May to August). Since there was no any other industries in the watershed, agricultural practices and sewage from the resident households, forest runoff and livestock wastes were the major sources of NPS discharges. A combination of management options, including management of soil erosion and fertilizer application, could lead to reductions in nutrient exports.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.4
• /
• pp.451-453
• /
• 2016

In this paper, we propose a Load Balance System for SFC based on DLP solution. SFC based on DLP solution does not distribute to the user data and each DLP server manages all traffic generated by the user device. When using existing algorithms such as the Load Balance Round Robin, Least Connection does not consider the resource usage of DLP server so traffic is not efficiently distributed due to different user traffic usage. It causes system failure and overload of the DLP server. Therefore, we propose the architecture of a Load Balance system for SFC based on DLP solution to perform the Load Balance based on the resource usage of DLP server through a LBM server in this paper.

• Environmental and Resource Economics Review
• /
• v.15 no.3
• /
• pp.425-450
• /
• 2006

The index of energy intensity(energy/GDP) has been a primary policy concern since it can clarify industry sectors which use energy intensively and generate $CO_2$ emission heavily. Although energy intensity index may be suitable for estimating $CO_2$ emission from an isolated industry sector, we need an index for induced $CO_2$ emission since industrial activities are interconnected in terms of input and output. By employing Environmental Input-Output Table 2000, this paper analyses the flow of energy demand and pollutants after first estimating an induced $CO_2$ emissions from various industrial sectors and economic activities. The paper reports higher induced $CO_2$ emissions from industry sectors with larger energy intensity since they produces goods or services retaining relatively considerable environmental load. Furthermore, it is shown that environmental load and $CO_2$ emissions in overall economy are likely increasing when the products of energy intensive industrial sector is used as inputs for less intensive sectors' production process. The result suggests we need consistent policy efforts to reduce energy intensity to lower $CO_2$ emissions.

• Proceedings of the IEEK Conference
• /
• 2003.07d
• /
• pp.1339-1342
• /
• 2003

클라이언트-서버 구조의 온라인 게임에서 서버의 역할은 매우 중요하다. 그러나 서버에 너무 많은 사용자가 동시에 접속할 경우에는 과도한 부하로 인하여 안정적인 서비스를 제공하지 못하는 경우가 발생할 수 있다. 이러한 문제를 해결하기 위하여 여러 대의 분산 서버를 활용한 방법이 사용되고 있다 분산 서버 구조에서는 부하가 특정 서버로 집중되는 것을 막는 것이 전체 시스템의 성능 향상을 위하여 필요하다. 이를 위하여 부하 평형 기법을 사용하고 있으며 관련 연구도 활발히 진행 중이다. 본 논문에서는 분산 서버를 이용한 온라인 게임 서버의 구조를 설계하고, 대량 사용자의 제약을 극복하기 위한 하나의 방안으로 다중 서버 시스템에서 실행되는 게임 서버 프로세스들에 대한 부하 평형 기법을 제시한다. 제안된 기법에서는 전체 게임을 소규모의 여러 게임 세상(Game World)으로 나누고 서비스가 진행되는 상황에서 게임 세상을 게임 서버들 사이에서 이동시킨다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.21 no.10
• /
• pp.52-58
• /
• 2007

This paper presents the wind-power model for generation adequacy assessment. Both wind-power and system load depend on time of a year and show their periodic nature with similar periods. Therefore, the two quantities have some probabilistic relations, and if one of them is given, the other can be decided with some probability. In this paper, the two quantities are quantized by k-means clustering algorithm and related probabilities among the cluster centers are calculated using sequential wind-power and system load data. The proposed model is highly expected to be applied for generation adequacy assessment by Monte-Carlo simulation with state sampling method.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.31 no.1D
• /
• pp.111-117
• /
• 2011

In the wake of increased concerns on reduction of greenhouse emission which started with United Nation's Framework Convention on Climate Change (UNFCCC) and Kyoto protocol, Korean government is making various efforts under the represented slogan "Low Carbon, Green Growth". Therefore, it is inevitable that construction industry also follow the Korea government's slogan and the international trend in environmental problems. This study identified several main construction materials and equipments of civil construction projects and suggested a environmental cost estimation method and related estimation standards (Public and private owners are distinguished). A case analysis of a real road construction project is also performed and characteristics according to the owner type is compared. This study analyzed the environmental impact to total construction cost variations. In the result, public owner required 11~16% of extra budget and private owner required 19~22% of extra costs. This study is limited in consideration of environmental factors and carbon trading prices.

• Journal of Animal Environmental Science
• /
• v.18 no.3
• /
• pp.235-246
• /
• 2012

Reusing livestock manure have various advantages in securing soil organic resources. In this study, the N-loading and recycling capacity assessment of animal manure was analyzed by comparing between the cultivated areas of crops and the amount of manure units that are generated from livestock manure. From this assessment, the possibility of recycling resources of livestock manure was evaluated. The amount generated of livestock manure in Gyeonggi-do were evaluated by applying the manure units to the number of livestock manure. The analysis of manure unit per ha shows that the N loading by MU is quite different by region. When it comes to nitrogen loading, the MU per ha of cultivated land in excess of the N-amount was the highest in the Gyeonggi-do province with 2.70 MU/ha, which is higher than the appropriate level. The Chungcheongnam-do province came next with 2.31 MU. So the recycling capacity assessment was carried out mainly based on areas of forage crops, rice that can be provided by recycling livestock manure. The recycling capacity ware highest in Jeollanam-do and Jeollabuk-do. In order to properly apply the livestock manure into organic resources, the seasonal situation that effects the nitrogen demands of crops along with the regional effects crop cultivation should be seriously analyzed. In addition, a system that can effectively produce and manage fertilizer should be established.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.20 no.1
• /
• pp.56-70
• /
• 2017

In this study, multi-image information for the central Taewha River basin was used to develop and analyze a distribution map of non-point pollution sources. The data were collected using a hyper-sensor (image), aerial photography, and a field spectro-radiometer. An image correction process was performed for each image to develop an ortho-image. In addition, the spectra from the field spectro-radiometer measurements were analyzed for each classification to create land cover and distribution maps of non-point pollutant sources. In the western region of the Taewha River basin, where most of the forest and agricultural land is distributed, the distribution map showed generated loads for BOD($kg/km^2{\times}day$) of 1.0 - 2.3, for TN($kg/km^2{\times}day$) of 0.06 - 9.44, and for TP($kg/km^2{\times}day$) of 0.03 - 0.24, which were low load distributions. In the eastern region where urbanization is in progress, the BOD, TN, and TP were 85.9, 13.69, and 2.76, respectively and these showed relatively high load distributions when the land use was classified by plot.