• 한국지리정보학회지
• /
• 제16권3호
• /
• pp.91-102
• /
• 2013

본 연구에서는 지방자치단체 내에서 생산되어 유통되고 있는 공간데이터의 유효활용방안을 제안하였다. 그를 위하여 부산광역시를 대상으로 각 부서에서 구축된 정보시스템과 관리되고 있는 공간정보를 파악하였다. 또한, 국내의 관련동향으로는 국가공간정보통합체계와 국가공간정보유통센터를 들 수 있는데 분산되어 있는 유통망을 국가공간정보유통센터로 통합하여 공공과 민간이 다 함께 참여할 수 있도록 서비스를 확대하고 있음을 알 수 있었다. 부산광역시의 중앙부처 보급 행정정보시스템은 총 22개이며 부산광역시에서 운영 중인 정보시스템은 총 168개로 파악되었다. 그 이외에도 2009년 국가공간정보체계 2차 시범사업을 시작으로 행정공간정보체계를 구축하였는데 환경, 도로교통, 축산 등 11개 분야 295종의 행정주제도가 있었다. 향후, 이들 시스템을 통합하고 관리하는 체계가 필요하며 정보시스템 통합 관리 및 연계, 고도화 방향 설정이 필요한 것으로 판단된다. 이를 위하여 (1)메타데이터 구축 및 정보시스템 연계 (2)공간데이터 유효활용을 위한 실증실험 (3)데이터센터 구축이 필요하다고 사료된다.

• 대한전기학회논문지:전력기술부문A
• /
• 제49권4호
• /
• pp.195-198
• /
• 2000

This paper illustrates a new method for constructing composite power system effective load duration curve(CMELDC) at load points. The main concept of proposed method is that the CMELDC can be obtain from convolution integral processing of the outage probabilistic distribution function of not supplied power and the load duration curve given at each load point. The effective load duration curve (ELDC) at HLI plays an important part in probabilistic production simulation, reliability evaluation, outage cost assessment and power supply margins assesment for power system planning and operation. And also, the CMELDC at HLII will extend the application areas of outage cost assessment and reliability evaluation at each load point. The CMELDC at load points using the Monte Carlo method and a DC load flow constrained LP have already been developed by authors. The effective load concept at HLII, however, has not been introduced sufficiently in last paper although the concept is important. In this paper, the main concept of the effective load at HLII which is proposed in this study is defined in details as the summation of the original load and the probabilistic loads caused by the forced outage of generators and transmission lines at this load point. The outage capacity probabilistic distribution function at HLII can be obtained by combining the not supplied powers and the probabilities of the not supplied powers at this load point. It si also expected that the proposed CMELDC can be applied usefully to research areas such as reliability evaluation, probabilistic production cost simulation and analytical outage cost assessment, etc. at HLII in future. The characteristics and effectiveness of this methodology are illustrated by case study of IEEE-RTS.

• 수산해양기술연구
• /
• 제58권2호
• /
• pp.141-152
• /
• 2022

As a method to understand the ecological habits around the artificial reef, various reports such as fishing gear survey, diving, sound survey, underwater CCTV and camera, etc. are reported. Among them, the sound survey method is carried out by installing an acoustic system on the ship and can be investigated regardless of the marine environment such as time constraints and turbidity. Such method, however, takes a lot of manpower and time as the ship travels at a constant speed. Investigations around artificial reefs are being conducted in an artificial way, and a lot of time and labor are consumed as such. Maritime buoys have been operated for various purposes such as route signs, weather observation, marine environment monitoring and defense monitoring for navigation safety in the past, but studies on monitoring systems for ecological habits and distribution of fish using marine buoys are remarkably insufficient. Therefore, this study aims to develop a system that allows users to directly monitor fish group detector data by estimating the distribution of fish groups around artificial reefs and using wireless communication at sea. In order to confirm the suitability of the maritime buoy used in this study, it was operated to compare data using LTE-equipped buoys capable of wireless communication and a data logger-type system buoy. Data transmission of buoys capable of LTE communication was carried out in a 10-minute ON, 10-minute OFF method due to the limitation of the power supply capacity, and data of the data logger-type buoy received full data. We compared and analyzed the data received from the two fish detectors. It is expected that real-time monitoring of the wireless buoy detection device using LTE will be possible through future research.

• 전기학회논문지
• /
• 제60권6호
• /
• pp.1280-1285
• /
• 2011

Recently, due to the use of fossil fuels for electric power production, carbon emissions increased excessively. Thereby, in order to replace fossil fuels, many studies about fossil fuels such as solar and fuel cell energy source are progressing. Fuel cell system has high energy conversion efficiency. Also, fuel cell system is environmentally friendly system because the carbon emission is almost not occur. Therefore, the fuel cell system is considered as the core technology of in the fields of the future energy and environmental. Fuel cell system has an effect on distribution power system because another power source of other than large power plants. So, fuel cell system can be degradation reason of power quality in the power system. In this paper, we constructed the system for an assessment on harmonics effect. The system is composed with power source, harmonics generation and linear load, fuel cell system. we also performed assessment on harmonics effect in customer and the distributed power system during grid connection of residential fuel cell system. An assessment cases are divided into three. A Case 1 is state that residential load and fuel system are connected to grid, Case 2 is state that residential load and harmonics load are connected to grid, and Case 3 is state that all loads are connected to grid. As a output of fuel cell system is increase, analysis results based on assessment system showed that power quality became more aggravation as effect of harmonics.

• Journal of Electrical Engineering and Technology
• /
• 제4권3호
• /
• pp.382-388
• /
• 2009

Recently, hydrogen energy has been anticipated to change the paradigm of conventional power systems because it can expand sustainable energy utilization and conceptually provide remarkable flexibility to power system operation. Since hydrogen energy can be converted to electric energy through fuel cells, fuel cells are expected to play an important role in the future hydrogen economy. In this paper, a Proton Exchange Membrane Fuel Cell (PEMFC) is modeled as an equivalent circuit and its steady-state characteristics investigated using the model. PEMFCs can be connected to power systems through power conditioning systems, which consist of power electronic circuits, and which are operated as distributed generators. This paper analyzes the effects of the characteristics of the PEMFC internal voltages and investigated the dynamic responses of the PEMFC under fault conditions. The results show that the fault current contribution of the PEMFC is different from those of conventional generators and is closely related to its operating point.

• 설비공학논문집
• /
• 제18권8호
• /
• pp.620-626
• /
• 2006

Recently, indoor air quality (IAQ) is one of the greatest problems in our modern societies. Although research for IAQ is made rapid progress but IAQ problems concerning in door microorganism contamination is required to be studied still more. So we have investigated the indoor microorganism concentration of a variety of department store, subway station, underground shopping center, kindergartens, library where people complain about the in-door air quality. The experiment on microorganism concentration of indoor air was carried out and the average of total microorganisms was measured. Comparing the experimental results with existing foreign criterion, the experimental results show that the ministry of environment recommendation microorganism concentration value ($800 CFU/m^3$) is in need of revision in the near future.

• 물과 미래
• /
• 제27권4호
• /
• pp.59-67
• /
• 1994

본 연구에서는 설계기준에 합당한 제약조건을 고려하여 최저경비의 관망시스템을 설계함을 목적으로 비선형계획법(NLP)을 적용하였다. 경기도 고양군의 고양배수지를 급수원으로 하는 배수유역에 실제 적용하여 기존의 설계와 비교한 결과 기존 수리모의모형에서 사용되고 있는 반복계산 과정이 필요없이 설계가 가능함을 알 수 있었고, 설계의 최적화를 도모하는 동시에 수요절점에서의 유량 및 수압조건을 만족시킬 수 있었다. 이상의 결과와 같이, 본 연구에서의 비선형계획법(NLP)을 이용한 상수도 관망설계가 실무에서도 효과적으로 사용될 수 있음을 알 수 있었고 최적화 설계로 인하여 경제적 측면까지도 고려할 수 있음을 알 수 있었다.

• 한국항만경제학회지
• /
• 제17권2호
• /
• pp.1-28
• /
• 2001

Korea has been at the forefront of efforts to enhance international cooperation in transport and communications within Northeast Asia. This effort is driven not only by the benefits that could accrue to the Korean Peninsula but also to all nations in the region. Mutual cooperation within Northeast Asia would reduce transport and communications costs and provide the basis for a regional transport and logistics network. Before progress can be made towards an integrated transport and communications system in Northeast Asia, however, there is a need to evaluate its prospects, outline a visionary plan, and detail a preferred strategy. The strategy to develop the Korean Peninsula as the gateway for Northeast Asia should harmonize with the region's common transport (and communications) policy The strategy adopted by South Korea is focused primarily on the development of an improved logistics infrastructure that would be extended to North Korea upon reunification. The seaport and airport developments In Korea will have to be supported by improved access to planned high-speed railways, expressways and freight distribution centers that, in turn, are to be integrated with new telecommunications and computer technologies. The benefits from these improvements will be lost unless existing government monopolies controlling seaport, airport, rail, road and expressway developments are commercialized to ensure that the price of transport reflects its actual cost. Technical harmonization between different modes should be promoted to facilitate efficient intermodal transport between the Korean Peninsula and the rest of Northeast Asia.

• 한국물환경학회지
• /
• 제18권3호
• /
• pp.283-290
• /
• 2002

In this study, home-made detection system by means of noble FIA is introduced on the measurement of toxic nitrite in the water samples collected from the area of Kwangju. As the standard calibration between 30 to 1000 ppb, the linearity has been shown more than 0.9999 as the correlation coefficient($R^2$) with the detection limit 1.5 ppb(S/N>2). The distribution of sample concentration was monitored as N.D. - 123 ppb which is wide span of concentrations in field water samples. The low level of nitrite is hardly detectable with other expensive sophisticated instruments including ion chromatography. Whereas the result of high concentration brings forth the necessity monitoring constantly our precious water resources. Successfully, the FIA system has played a very important role detecting wide span of nitrite in water sample. This technique can be adopted for controlling our environment in the near future.

• 상하수도학회지
• /
• 제29권1호
• /
• pp.97-106
• /
• 2015

A CCTV inspection method has been widely used to assess sewer condition and performance, but Korea lacks a proper decision support system for prioritizing sewer repair and rehabilitation (R&R). The objective of this paper is to introduce the results that we have developed in the Sewer Condition Assessment and Rehabilitation Decision-making (SCARD) Program using MS-EXCEL. The SCARD-Program is based on a standardized defect score for sewer structural and hydraulic assessment. Priorities are ranked based on risk scores, which are calculated by multiplying the sewer severity scores by the environmental impacts. This program is composed of three parts, which are decision-making for sewer condition and performance assessment, decision-making for sewer R&R priority assessment, and decision-making for optimal budget allocation. The SCARD-Program is useful for decision-makers, as it enables them to assess the sewer condition and to prioritize sewer R&R within the limited annual budget. In the future, this program logic will applied to the GIS-based sewer asset management system in local governments.