• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.353-359
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• 2015

This study introduces a resource recycling system in urban apartment complex using four different technologies. The four technologies, called 4G, include a production technology for reclaimed water (Green water), a biogas production technology from organic waste (Green biogas), a reuse technology of rainwater (Green rainwater), and urban agropark (Green pyramid). Green water is the technology for producing the reclaimed water from wastewater, rainwater and underground water, and the average concentrations of BOD, SS, T-N and coliform of reclaimed water were 7.8mg/L, ND (not detected), 4.9mg/L and ND, respectively. Green biogas is the technology for producing biogas and effluent after treating organic wastes (e.g. food waste and night soil) discharged from households, and the average production rates of hydrogen and methane were $0.33m^3/m^3/d$ and $0.24m^3/m^3/d$, respectively. Green pyramid, agricultural farm operated by biogas and reclaimed water, provides a healthy and recreational space for residents, and plant growth rates using treated water and reclaimed water showed height of 1.32cm and weight of 112.8g. Therefore, 4G technologies can improve the recycling rate and treatment efficiencies of waste and wastewater in an apartment complex.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.6
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• pp.453-457
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• 2016

In various industrial plants such as power generation plants, petrochemical plants, and unit factories, there is an increasing demand for a system that generates hot water using waste or surplus steam. Compact steam unit (CSU), which produces hot water by using steam, is a good solution considering energy reuse. In this study, as a basic study to develop a high-pressure CSU, heat transfer characteristics of a hybrid heat exchanger were investigated through experiments, in order to use the hybrid heat exchanger instead of a conventional plate heat exchanger as the core component of CSU. The experimental results are the followings. Heat balance between the hot side and cold side was satisfied within ${\pm}5%$. Overall heat transfer coefficient increased linearly as the Reynolds number increased and exceeded $5,524W/m^2K$ when the flow velocity was above 0.5 m/s. In addition, pressure drop also increased as the Reynolds number increased, and pressure drop per unit length was below 50 kPa/m.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.470-470
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• 2011

환경부 하수재이용사업은 2007년도 하수도법 개정을 통해 공공하수처리시설 처리수의 재이용 의무화를 시작으로 2010년도 "물의 재이용 촉진 및 지원에 관한 법률"의 시행으로 전국적으로 사업이 확대되고 있다. 제주도 월정하수처리장은 2009년도 하수재이용사업지구로 선정이 되어 2010년도부터 농업용목적의 재이용으로 구체적인 설계와 시공이 추진되고 있는 사업지구이다. 제주도에서는 지하수보존을 위해 대체수자원 개발 방안을 시급히 마련중에 있다. 특히, 제주도 농업용수 종합계획수립(제주도, 2004)에는 하수처리수를 농업용수로 이용하기 위한 계획을 수립할 정도로 지하수 사용량을 줄이기 위한 노력을 진행중에 있으며, 그 일환으로 하수재이용사업을 지속적으로 추진하고 있다. 하수처리수의 농업용수 재이용은 사용된 물을 재이용함으로써 물과 에너지를 절약할 수 있고, 유역 또는 해양으로 배출되는 오염원을 억제하는 장점이 있는 반면에 농산물 생육에 직접 영향을 줄뿐만 아니라 주변의 수질 생태 토양 환경 및 영농인의 보건에도 영향을 주기 때문에 장기적인 관찰과 검증작업이 필요하다. 이 에 서울대와 한국농어촌공사는 안전한 농업용수 재이용기술을 개발하기 위해 장기간 현장시험을 통해 재이용 재배기술과 함께 보건환경에 미치는 영향을 검증하였고 그 개발기술을 월정사업지구에 적용하게 되었다. 월정하수처리장이 위치한 제주 동부의 월정지역은 농지면적이 밭(374ha)과 과수(12ha)등 제주도의 전형적인 농촌마을으로 주요 재배작물은 마늘과 당근, 쪽파, 콩 등으로서 농업기반시설의 미비로 영농에 어려움을 호소하고 있으며, 2006년도에 발생한 가뭄으로 그 해 평균 수학량의 30%가 감소된 바 있는 지역이다. 제주도 농업용수 종합계획수립(2004, 제주도)에서는 10년에 한발을 기준 으로 $43,000m^3$/일의 용수가 부족할 것으로 분석하였으며 최근 $35,000m^3$/day 규모의 상수도 확보사업 계획 수립하였으나 여전히 농업용수가 부족하다. 방류수의 수질은 방류수수질기준을 만족하지만 염분함량이 높아 직접 농업용으로 사용하기에는 적당하기 않고, 농업용재이용방류수 수질기준에 맞도록 재이용시스템을 통해 재처리하여 농업용수로 사용해야 한다. 제주도에서는 이미 제주 서부하수처리장 농업용수 재이용사업(이하 판포재이용사업)'이 완료되어 재이용수를 농업용수로 공급하고 있으며 향후 지속적으로 하수재이용사업이 확대될 것으로 판단된다.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.1
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• pp.101-109
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• 2009

This CW(Construction wastes) are increasing as construction industry is growing, so many countries make efforts to recycle CW. Korea also made a stipulation for recycling CW. But the main content of this stipulation is for using recycled aggregates. Advanced countries try to increase reuse rate of not only recycled aggregate but also other kinds of wastes. So they are adopting SDM(separating dismantlement) method and we are also planning to make the system for SDM. This study is about SDM analysis through construction field investigation and difference analysis between SDM and UDM comparing predictive amount by UDM with real generated amount by SDM. First, the generated amount of construction wastes by SDM is more than estimated amount by UDM, and mixed waste was specially reduced more than UDM. The warehouse is easier than the office building to applicate SDM. But still there is no manual for SDM in the site, so establishment of SDM is demanded.

• Journal of KIISE:Software and Applications
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• v.35 no.2
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• pp.70-80
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• 2008

Today, businesses have to respond with flexibility and speed to ever-changing customer demand and market opportunities. Service-oriented architecture (SOA) is the best methodology for minimizing the complexity and the cost of enterprise-level infrastructure and for maximizing the productivity and the flexibility of an enterprise. Most of the enterprise-level SOA delivery strategies deal with the top-down approach, which organization has to define the business processes, to model business services, and to find the required services or to develop new services. However, a lot of peoples want to maximally reuse legacy component-based systems as well as to deliver SOA into their organizations. In this paper, we propose a bottom-up approach for identifying business services with proper granularity. It can improve the reusability and maintenance of services by considering not data I/O of components of legacy applications but GUI event patterns. Our proposed method is applied to MIS with 129 GUIs and 13 components. As a result, the valiance of the coupling value of components is increased five times and three business services are distinctly exposed. It also provides a 49% improvement in reducing the relationship problems between services over a service identification method using only partitioning information of components.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.3
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• pp.198-207
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• 1990

Among the biodegradable liquid waste treatment and disposal methods, ocean dumping is a cost-effective and productive manner considering reuse point of view However, when biodegradable liquid waste is dumped in the ocean, oxygen consumption by the decomposition of organic matter must be considered. The purpose of this study is to determine the maximum allowable concentration and dumping rate in the southern waters of the East Sea based on dissolved oxygen level. Streeter and Phelps' model has been used to determine the maximum allowable concentration. Factors in this model, deoxygenation constants and reaeration coefficients, have been determined by appling oxygen consumption method and closed system model. Deoxygenation constants and reaeration coefficients from surface to each standard depth are $0.24\~0.29/day\;and\;0.03\~0.39/day$ in summer, $0.17\~0.20/day\;and\;0.04\~0.56/day$ in winter, respectively. The allowable organic matter concentration($mgBOD/\iota$) to the dissolved oxy-gen sag value of $5mg/{\iota}$ is represented $17.23\times(H)^{-0.37}$ in summer, and $64.96\times(H)^{-0.52}$ in winter by mixing depth(H, m). Csanady's experiment has been applied to estimate the optimum dumping rate. The optimum dumping rate($R,\;m^3/sec$) can be written as a product of the beam(b, m) and the draft(h, m) of vessel, and biochemical oxygen demand of waste($L_n,\;mg/{\iota}$) $R=275{\times}bh^{0.63}L_n^{-1}$ in summer $=745{\times}bh^{0.48}L_n^{-1}$ in winter. The difference of dumping rate between in summer and winter is due to the oxygen distribution.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.6
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• pp.561-567
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• 1987

The purpose of this study was to find out the removal capacity of harmful ammonia by different filter media in the submerged biological filters in a given space of chamber. Four materials, pile cloth, corrugated skylight roofing plate, embossed plastic plate, and gravel, were used as the experimental filter media. Each filter medium was placed in two aquariums, each aquarium measuring $90cm\times60cm\times60cm\;(depth)$. Under the normal operating condition, the average of mean ammonia removal rates during the first and second functioning periods by each filter material which occupied tile space in the filter chamber (aquarium) was as follows: 1. Pile cloth: $8.381\;g{\cdot}m^{-3}.\;day^{-1}$ 2. Corrugated skylight roofing plate: $7.834\;g{\cdot}m^{-3}.\;day^{-1}$ 3. Embossed plastic plate: $7.797\;g{\cdot}m^{-3}.\;day^{-1}$ 4. Gravel: $7.051\;g{\cdot}m^{-3}.\;day^{-1}$ Thus, there were no significant differences between the media, but at the time of practical application of these materials, some other factors such as investment cost, easiness for the removal of excess detritus accumulated in tile interstices of filter media, etc. should be fallen into consideration. When large units are required, in particular, removal of excess detritus from tile gravel bed is extremely difficult, and in case of pile cloth filters the installation work is much complicated and a problem in supporting the structure when drained also exists. In these respects, corrugated skylight roofing plate and embossed plastic plate seem to be more optimal, but again in practice the local situation for the availability and the price of the materials should be rechecked and the fitness of tile materials in the particular filter chambers under use or under consideration for construction must be taken into account.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.1
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• pp.96-107
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• 2015

Brownfield sites are beginning to be considered as potentially useful areas for landscape design and planning, with post-industrial areas such as water treatment facilities and military training bases being converted into useful landscapes such as parks and recreation areas. These redevelopments bring broad benefits through revitalizing communities and increasing property values, thus, increasing the demand for comprehensive management and planning policies. This study examines changes in U.S. brownfield policies and programs and, identifies their periodic characteristics over the thirty years since the Superfund program was introduced in 1980. A descriptive and interpretive approach was utilized, focusing specifically on a time sequential analysis of the data gathered from the overview of the Environmental Protection Agency's web-based documents and related literature. The primary changes in and characteristics of programs and policies were analyzed and divided into three periods : environmental protection, remediation and reuse, and comprehensive planning. Four major features were identified: relaxation and readjustment of regulation, diversification of support programs, a mix of top-down and bottom-up approaches, and database system building. The study examines how common brownfield problems such as site identification difficulties and assessment and remediation cost have been dealt with in the regulatory context and has implications for future policies and programs for effective brownfield planning and management in Korea.

• The Transactions of the Korea Information Processing Society
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• v.4 no.7
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• pp.1804-1820
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• 1997

In this paper, an efficient call control procedure is presented for next generation wireless ATM networks and its performance is mathematically analyzed using the open queueing network. This procedure is based on a new scheme called as the cell clustering. When we use the cell clustering scheme, at the time that a mobile connection is admitted to the network, a virtual cell is constructed by choosing a group of neighboring base stations to which the call may probabilistically hand over and by assigning to the call a collection of virtual paths between the base stations. Within a microcell/picocell environment, it is seen that the cell clustering can support effectively a very high rate of handovers, provides very high system capacity, and guarantees a high degree of frequency reuse over the same geographical region without requiring the intervention of the network call control processor each time a handover occurs. But since mobiles, once admitted, are free to roam within the virtual cell, overload condition occurs in which the number of calls to be handled by one base station to exceed that cell site's capacity of radio channel. When an overload condition happens, the quality of service is abruptly degraded. We refer to this as the overload state and in order to quantify the degree of degradation we define two metrics, the probability of overload and the normalized average time spent in the overload state. By using the open network queueing model, we derive closed form expressions for the maximum number of calls that can be admitted into the virtual cell such that the two defined metrics are used as the acceptance criteria for call admission control.

• The Journal of the Korea Contents Association
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• v.17 no.9
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• pp.1-11
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• 2017

The importance of data curation is increasingly recognized as the need of data reuse drastically grows. Due to recent data explosion, scientists invest almost 90% of their efforts in the retrieval and collection of data needed to their study. In this paper, we deal with the development and application of a collaborative environment for community-driven data curation which is essential to enhance scientific data reusability and citability. The collaborative scientific data curation environment focuses on the cross-linking between data (or data collections) and their associated literatures to capture and organize inter-relations among research results in a specific domain. Also, plenty of contextual information is provided as metadata in order to support users in understanding data. The cross-linking has been realized by using DOI system to guarantee global accessibility to data and their relationships to literatures. The curation environment has been adopted to build a community-driven curated DB by a globally well-known intrinsically-disorderd protein research group. The curated DB will drastically reduce researchers' efforts to retrieve and collect the data required for scientific discovery.