• Journal of Korean Society of Water and Wastewater
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• v.33 no.4
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• pp.291-297
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• 2019

Phosphorus is a vital resource for sustaining agriculture and nutrition, but a limited non-renewable resource. Thus, the recovery of phosphorus from waste activated sludge(WAS) was attempted by microwave heating and magnesium ammonium phosphorus(MAP) crystallization. Polyphosphate-accumulating organisms(PAOs) in WAS release phosphate from the cell when they are exposed to high temperature environments. Microwave heating caused phosphorus and ammonia to release from WAS. The amount was increased with increasing temperature, showing that 88.5% of polyphosphate present in the cells were released in the form of phosphate at $80^{\circ}C$. A similar result was also observed in the release of ammonia. On the other hand, both phosphorus and ammonia were crystallized with magnesium, and then was harvested as MAP. Phosphorus recovery rate reached almost 97.8%, but the ammonia was about 13.4%. These results cleary indicate that phosphorus could be recovered from WAS using a physiological trait of PAOs. Heavy metal analyses also show that the MAP crystal is useful and safe as a phosphorus fertilizer.

• Journal of Korean Society of Forest Science
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• v.99 no.6
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• pp.827-835
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• 2010

Reliable forest statistics provides important information to meet the UNFCCC. In this respect, the national forest inventory has played a crucial role to provide the reliable forest statistics for several decades. However, the previous forest statistics calculated by administrative district has not provided spatial information in a small scale. Thus, this study focused on developing models to estimate an explicit spatial distribution of forest growing stock. For this, first, stand volume model by stand types was developed using National Forest Inventory(NFI) data. Second, forest type map was integrated with this model. NFI data were used to calculate plot-level stand volume and basal area. The stand types of NFI plot including the species composition, age class, DBH class and crown density class are very crucial data to be connected with forest type map. Finally, polygonlevel stand volume map was developed with spatial uncertainty map. Average stand volume was estimated at 85.7 $m^3$/ha in the study area, and at 95% significance interval it was ranged from 79.7 $m^3$/ha to 91.8 $m^3$/ha.

• Journal of the Korean Solar Energy Society
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• v.40 no.5
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• pp.13-22
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• 2020

Day ahead forecast is necessary for the electricity market to stabilize the electricity penetration. Numerical weather prediction is usually employed to produce the solar irradiance as well as electric power forecast for longer than 12 hours forecast horizon. Korea Meteorological Administration operates the UM-LDAPS model to produce the 36 hours forecast of hourly total irradiance 4 times a day. This study interpolates the hourly total irradiance into 15 minute instantaneous irradiance and then compare them with observed solar irradiance at four ground stations at 1 minute resolution. Numerical weather prediction model employed here was produced at 00 UTC or 18 UTC from January to December, 2018. To compare the statistical model for the forecast horizon less than 3 hours, smart persistent model is used as a reference model. Relative root mean square error of 15 minute instantaneous irradiance are averaged over all ground stations as being 18.4% and 19.6% initialized at 18 and 00 UTC, respectively. Numerical weather prediction is better than smart persistent model at 1 hour after simulation began.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.300-302
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• 2008

For the evaluation of wind resources, numerical simulation was carried out as a tool for establishing wind map around the korean peninsula. Initial and boundary condition are given by 3 hourly RDAPS(Regional Data Assimilation and Prediction System) data of KMA(Korea Meteorology Administration) and high resolution terrain elevation land cover(30 seconds) data from USGS(United States Geological Survey). Furthermore, Data assimilation was adopted to improve initial meteorological data with buoy and QuikSCAT seawinds data. The simulation was performed from 2003 to 2006 year. To understand wind data correctly in complex terrain as the korean peninsula, at this research, Wind map was classified 4 categories by distance from coastline and elevation.

• International Journal of Contents
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• v.12 no.3
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• pp.29-33
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• 2016

Cloud computing makes extensive use of virtual machines that permit for workloads, as well as resource usage, to be isolated from one another, and a hypervisor can be used by a virtual machine to construct cloud computing infrastructure. However, the hypervisor has high resource usage when constructing virtual machines, which results in a waste of allocated resources when not activated. Docker provides a more light-weight method to obtain agile computing resources based on a container technique that handles this problem. In this study, we have chosen this specific tool due to the increasing popularity of MapReduce and cloud container technologies such as Docker. This study aims to automatically configure Twister workloads for container-driven clouds. Basically, this is the first attempt towards automatic configuration of Twister jobs on a container-based cloud platform VM for many workloads.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.184.1-184.1
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• 2010

In order to research the way to evaluate wind resource without actual Met Mast data, this paper has been carried out on the southeastern region of Jeju island, Korea. Although wind turbine has been an economical alternative energy resource, misjudging the prediction of lifetime or payback period occurs because of the inaccurate assessment of wind resource and the location of wind turbine. Using WindPRO(Ver. 2.7), a software for wind farm design developed by EMD from Denmark, wind resources for the southeastern region of Jeju island was analyzed, and the performance of WindPRO prediction was evaluated in detail. Met Mast data in Su-san 5.5Km far from Samdal wind farm, AWS in Sung-san 4.5km far from Samdal wind farm, and Korea Wind Map data had been collected for this work.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.532-533
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• 2009

The national wind map of South Korea has been established as a core data to support national strategy building and promotion of wind energy dissemination. The national wind map has been made by numerical wind simulation with the spatial resolution of 1 km horizontal, 10m vertical and temporal resolution of 1 hour interval for 5 years period (2003-2007). Therefore, an application system linked with the national wind map named KIER-WindMap$^{TM}$ is being developed to be used by the government, local government, developers and researchers. We introduce the current status of the application system and the future development plans.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.7B
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• pp.991-1000
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• 2010

The Hierarchical Mobile IPv6 (HMIPv6) has been proposed to accommodate frequent mobility of the Mobile Node. HMIPv6 can effectively reduce the signaling overhead and latency. However, it has a problem that the registration of a mobile node concentrates on the furthest MAP(Mobility Anchor Point) when the mobile node enters into a new domain. This paper proposes a new load distribution mechanism by using the concept of Nash Bargaining Solution. The main advantage of the proposed scheme can prevent load concentration from being registered to the specified MAP based on the weight value according to the available resource-ratio of a MAP. With a simulation study, the proposed scheme can improve network performance under widely diverse traffic load intensities.

• Spatial Information Research
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• v.11 no.4
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• pp.391-407
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• 2003

Recently, a lot of interests are commanding in link practical use of country information and cadastral information for management of efficient country resource and administration of land. As map information, a lot of interests are commanding in construction of synthetic informations system including digital map and cadastral map. In this study, achieves analysis about non-coincidence causes of digital map and cadastral map, and achieve investigation about representative algorithm that is used in conversion of map for correct overlay between two map and opes overlay plan. Also, presented plan that can ready fetters for integration database construction of digital map and cadastral map by achieving study about matching security plan between map and plan elevation of the quality.

• Proceedings of the Korean Society of Computer Information Conference
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• 2009.01a
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• pp.13-18
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• 2009

Topic Map을 구축하는데 있어서 봉착하는 문제는 특정분야 전문가들이 Topic Map의 구성과 체계에 익숙하지 않다는 점이다. 이를 해결하기 위해서 Topic Map의 모든 요소들을 새로이 작성하는 것 보다는 작성하려는 분야에 대해 기 구축된 정보자원이 존재할 경우 이를 최대한 재활용하여, 모은 요소들을 추출한 다음 Topic Map 온톨로지로 변환하고 이용하는 것이 시간과 비용을 절약할 수 있는 효율적인 방법일 것이다. 본 연구에서는 기 구축된 학술DB보부터 Topic Map에서 재활용할 수 있는 요소들을 추출하기 위한 정보 소스로서 데이터베이스 스키마와 MARC에서 언급하는 메타데이터를 이용하는 것은, 기초 학문자료의 복잡한 관계의 개념구조, 자료유형 및 자료간의 의미적 상관관계 표현에 있어 효율적인 개발방법임을 제안한다.