• 상하수도학회지
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• 제28권1호
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• pp.111-124
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• 2014

Decentralized water supply systems, treating the water in users'vicinity, cutting down the distribution system, utilizing the alternative water resources(rainwater harvesting, water reclamation and reuse and so on.) and saving energy and other resources, could be categorized into POU(Point-Of-Use), POE(Point-Of-Entry) and community small scale system. From the literature review, we could thought that decentralized water supply system and hybrid system(integrating centralized and decentralized water supply system within urban water management) might have strengthening comparative advantages to centralized system with respect to: (1) water security, (2) sustainability, (3) economical affordability. Even though it is difficult to derive and quantify direct benefit advantages from decentralized and hybrid system in comparison with centralized system, (1) operational cost reduction, (2) assurance for safe and stability water supply and (3) greenhouse gas reduction can be expected from successful establishment of the former.

• Environmental Engineering Research
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• 제18권2호
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• pp.109-114
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• 2013

In Cukhe, a village located in the outskirts of Hanoi, Vietnam, people suffer from a shortage of high-quality water due to an arsenic contaminated supply water resource. We installed catchments, filters and settled tanks in the existing rainwater harvesting facility to improve water quality, and ten portable rainwater tanks to provide good-quality drinking water to the poor households and kindergartens in the dry season. The triple bottom line considerations, as well as the environmental, economic, and social impacts of the rainwater harvesting (RWH) systems are examined. RWH is a sustainable method to obtain good-quality drinking water at low cost and with little energy expenditure. Education of the system also encourages that continuation of the system and expansion can lead into economic prosperity, as the safe drinking water can be sold to the community. Hence, RWH is a unique proposal as sustainable drinking supply water for improving the lives and health of residents in Cukhe and other sites where water supply sources are contaminated.

• 한국유기농업학회지
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• 제20권4호
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• pp.447-458
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• 2012

This study was carried out to evaluation of biomass generation mechanisms and to propose the estimation method of biomass generation. Agricultural by-product biomass is generated during crops cultivation and after harvest. However these are not uniformly generated yearly and these depending on the seasons. For planning of biomass utilization, accurate information of the biomass resources is needed, especially characteristic and productivity of biomass are necessary. Agricultural by-product biomass are generated in a wide area being scattered and it is one of the major reason why agricultural biomass utilization is not activated compared with other waste biomass. In this study, estimation and evaluation biomass generation is achieved in specific spatial and temporal boundary, A-city in Gyeongi-do and september to November respectively. Quantity and quality of by-product biomass show big difference depending on the crop species and cultivation periods and these difference bring up that accurate biomass estimation should be considered during planning of biomass utilization and technology selecting for biomass converting to energy and other forms.

• 기술혁신연구
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• 제14권3호
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• pp.155-182
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• 2006

Science & Technology(S&T) personnel have been Playing a major role to develop our country since S&T is the most important factor in enhancing national competitiveness in the 21st century, As S&T activities are done by S&T personnel, it is essential to improve the welfare of S&T personnel in order to increase the performance of S&T activities. We should motivate them to pour their efforts and energy in S&T activities. However, the issue of S&T personnel's welfare has not been discussed sufficiently not only in academic research, but also in actual S&T policies. It has caused many social problems, for example, avoidance of S&T areas by young generation, low social recognition of S&T community, and so on. Under this background, this paper aims at investigating how to effectively improve S&T personnel's welfare. In this paper, we will suggest the 'Comprehensive Welfare Town for S&T personnel' as an effective instrument for improving of S&T personnel's welfare. In particular, we will discuss the detailed aspects of the comprehensive welfare town : objectives, strategies and budgets.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 추계학술대회 논문집
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• pp.200-202
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• 2008

동해 울릉분지에서는 시추선 RemEtive를 사용하여 UBGH-X-01 가스하이드레이트 탐사가 2007년에 실시되었다. 본 연구에서는 천부 가스하이드레이트가 확인된 UBGH1-10 정점에서 무인잠수정(Quantam WROV)을 사용하여 획득된 푸쉬코어와 해저지형 분석을 수행되었다.UBGH1-10 정점은 seismic chimneys의 탄성파 특성이 발달된 지역이다. 이곳에서는 해저표면으로부터 수 m 하부에서 가스하이드레이트가 발견되었다. 이 정점은 수 m 높이의 얕은 둔덕들이 무인잠수정에 부착된 비디오 카메라에 의해서 관찰되었다.이곳에서 채취된 길이 약40 cm의 푸쉬코어는 생물교란된 뻘질 퇴적물로 구성되어 있으며, 가스하이드레이트와 chemosynthetic community는 관찰되지 않았다. 푸쉬코어는 X-ray fluorescence scanner를 사용하여 퇴적물의 26가지 원소 조성을 분석하였다. UBGH1-10 정점의 산화환원환경은 Mo/Al과 Mn/Ti 원소비를 이용하여 천부 가스하이드레이트가 발견되지 않은 UBGH1-9와 UBGH1-1 정점과 대비하였다. 이 정점의 일차생산력은 Ba/Al 원소비를 이용하여 다른 정점과 대비하였다. 천부 가스하이드레이트가 발견된 UBGH1-10 정점은 활발한 가스방출과 관련된 생물집단 서식 또는 자생광물 형성의 흔적이 발견되지 않으며, 퇴적물에서도 산화환원환경과 일차생산력의 큰 차이가 관찰되지 않는다.

• 소음진동
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• 제3권4호
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• pp.341-352
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• 1993

Although a frequency analysis by FFT algorithm has been widely used in the vibration community, this approach has somewhat limited features when an analysist want to see the details of frequency trends because FFT shows only energy contents along frequencies. So the concept of instantaneous frequency that represents the dominant frequency component at each time needs to be introduced. In this paper, to get the instantaneous frequency, two methods are used. Methods using Hilbert transform and evolutionary spectrum are those. One of the problems of estimating instantaneous frequency using Hilbert transform is that it is normally very sensitive to signal to noise ratio(SNR) because of the differentiation. Moving window is applied on the estimation of instantaneous frequency, and instantaneous frequency histogram are used to handle this problem and proved to be very effective. Computer simulations for various signals have been done to understand the characteristics of instantaneous frequency. The usefulness of signal analysis using instantaneous frequency was tested by three simple experiments, which were engine experiment, beam experiment, and car door experiment. The instantaneous frequency analysis is found to be a useful technique to analyze the signals that have time varying frequencies.

• 미생물학회지
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• 제27권2호
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• pp.130-138
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• 1989

소양호에서 측정된 세균 체적, 세균 생물량 및 세균 생산량 등의 미생물학적인 요인의 변화에 미치는 물리화학적 환경요인의 영향을 통계학적 방법으로 분석을 하였다. 상관관계 분석과 중회귀 분석 결과 수온은 대부분의 미생물학적 요인에 폭넓은 영향을 미침을 알 수 있었다. 총 세균수, 세균 체적, 세균 생물 량 및 saprophyte 수외 변화는 엽록소 a와 pheophytin a의 존재와 높은 상관관계를, $^{3}H$-thymidine incorporation rate에 의해 측정된 세균 생산량은 seston의 농도에 큰 영향을 받는 것으로 분석되었다. 소양호 수중생태계에서의 세균 체적 및 세균 생물량의 미생물학적 요인은 미생물 군집에게 탄소와 에너지원으로 작용하는 유기물질의 제공원인 식물성 플랑크톤의 분포와 seston의 농도에 의해 조절되고 있음을 시사하여 준다.

• 생태와환경
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• 제41권2호
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• pp.128-136
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• 2008

An attempt was made in the Veeranam freshwater lake with the objectives to collect, identify, describe and document the algae occurring from March 2007 to August 2007. Qualitative and quantitative characterization of phytoplankton and analysis of physico-chemical parameters of water samples were carried out at monthly intervals during the study period in the western and eastern sides of the lake. It was found that the phytoplankton community embraced 68 genera belonging to four classes viz., Bacillariophyceae (40), Chlorophyceae (22), Cynophyceae (4) and Euglenophyceae (2). There were significant influences of various physico-chemical parameters on the phytoplankton population density. Commonly occurred genera, Oscillatoria (Cyanophyceae), Navicula (Bacillariophyceae) and Scenedesmus (Chlorophyceae), were subjected to energy dispersive spectroscopic analysis (EDS). They were found to accumulate different elements such as Zn, P, S, Ca, Mg, Fe, N, Si, Cl and Mn. Among these the member Cyanophyceae contained Zn, P, Mg, Ca, Mn, S and N. Bacillariophyceae Si, Zn, Mg, Cl, N, Fe, and Ca. Chlorophyceae Ca, Mg, N, Fe, Cl, Zn, Si and Mn. Thus these observations would determine the chemical dialogue between the cell structures and role of the elements. Further, it gives the clue about the phytoplankton growth requirements.

• 한국주거학회논문집
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• 제17권2호
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• pp.117-124
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• 2006

Korean urban traditional housing abandoned by the social apathy promptly disappearing form our sight, or ruining. It tells that the strategies we are using today are impossible to fulfill socio-economic needs of residents here. So it needed to find out the strategies which can change this place better to live in. Consolidating the street parking lots fer cars can be one of the important solutions to the area. By using cul-de-sac, after setting up small unit of communities, we will have chance to have a small public space, and at the same time it can help to set up our tradition of people's intimacy inside the community. Most people have their own cars, and the need of parking lots becomes more serious. So, a meeting place like public well in the past must replace parking lots. On the other hand, it is important to re-consolidate existing land to obtain appropriate land size for other uses. Today, the use of private space (house, private lots, etc..)and public space(streets, local offices) is very important. NIMBY (Not In My Back Yard) attitude should also be reconsidered. All these negative social aspects come from negative social relationship, thus we should consider them with care and deep understandings. The traditional housing of Korea should not be abandoned as slum, but this should be transformed in terms of the conservation since it is superior in its ecological and energy conservation aspect.

• Environmental Engineering Research
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• 제25권3호
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• pp.274-280
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• 2020

The marine sediment sustains from the anoxic condition due to increased nutrients of external sources. The nutrients are liberated from the sediment, which acts as an internal source. In hypoxic environments, anaerobic respiration results in the formation of several reduced matters, such as N₂ and NH₄⁺, N₂O, Fe²⁺, H₂S, etc. The experimental results have shown that nitrogen and sulfur played an influential, notable role in this biogeochemical cycle with expected chemical reductions and a 'diffusive' release of present nutrient components trapped in pore water inside sediment toward the bulk water. Nitate/ammonium, sulfate/sulfides, and ferrous/ferric irons are found to be the key players in these sediment-waters mutual interactions. Organonitrogen and nitrate in the sediment were likely to be converted to a form of ammonium. Reductive nitrogen is called dissimilatory nitrate reduction to ammonium and denitrification. The steady accumulation in the sediment and surplus increases in the overlying waters of ammonium strongly support this hypothesis as well as a diffusive action of the involved chemical species. Sulfate would serve as an essential electron acceptor so as to form acid volatile sulfides in present of Fe³⁺, which ended up as the Fe²⁺ positively with an aid of the residential microbial community.