• Title/Summary/Keyword: Restoration Process

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Primary Restorative Transmission Line Selection for Myanmar's Electric Power System

  • Kim, Yong-Hak;Song, In-Jun;Jang, Byung-Tae;An, Yong-Ho
    • Journal of Electrical Engineering and Technology
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    • v.5 no.2
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    • pp.191-196
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    • 2010
  • Power system restoration following a massive or complete blackout starts with energizing the primary restorative transmission system. During this primary restoration process, unexpected overvoltage may happen due to nonlinear interaction between the unloaded transformer and the transmission system. In the case of the Myanmar electric power system, there are so many wide outage experiences, including complete blackout cases, caused by 230kV line faults and so on. Consequently, Myanmar's system operators have been well trained to deal with wide blackouts. Howver, system blackout restoration has been conducted by relying on the experience of only a few specialists. So, more scientific analysis is required to meet the requirements necessary to ensure fast and reliable system restoration. This paper presents analytical results on the primary restorative transmission system of Myanmar, focusing on the problems during the early restoration process. Methodologies are presented that handle load pick-up, terminal voltage and the reactive capability limitation of black-start generators to compensate the Ferranti effect. Static and dynamic simulation with the PSSolution and EMTDC programs respectively for the six cases are performed in order to select the primary restorative transmission lines.

Application of Three-dimensional Scanning, Haptic Modeling, and Printing Technologies for Restoring Damaged Artifacts

  • Jo, Young Hoon;Hong, Seonghyuk
    • Journal of Conservation Science
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    • v.35 no.1
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    • pp.71-80
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    • 2019
  • This study examined the applicability of digital technologies based on three-dimensional(3D) scanning, modeling, and printing to the restoration of damaged artifacts. First, 3D close-range scanning was utilized to make a high-resolution polygon mesh model of a roof-end tile with a missing part, and a 3D virtual restoration of the missing part was conducted using a haptic interface. Furthermore, the virtual restoration model was printed out with a 3D printer using the material extrusion method and a PLA filament. Then, the additive structure of the printed output with a scanning electron microscope was observed and its shape accuracy was analyzed through 3D deviation analysis. It was discovered that the 3D printing output of the missing part has high dimensional accuracy and layer thickness, thus fitting extremely well with the fracture surface of the original roof-end tile. The convergence of digital virtual restoration based on 3D scanning and 3D printing technology has helped in minimizing contact with the artifact and broadening the choice of restoration materials significantly. In the future, if the efficiency of the virtual restoration modeling process is improved and the material stability of the printed output for the purpose of restoration is sufficiently verified, the usability of 3D digital technologies in cultural heritage restoration will increase.

Emergy Perspectives of Ecosystem Restoration in Korea

  • Kang, Dae-Seok
    • Ocean and Polar Research
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    • v.24 no.1
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    • pp.87-92
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    • 2002
  • The emergy (spelled with an 'm') concept was introduced to provide a new insight into ecosystem restoration efforts in Korea. The emergy is defined as the available energy of one kind previously required directly and indirectly to make a product or service. It is an effort to evaluate the true contributions of natural resources to our economy. It tries to include both contributions from natures free works and human services to develop and process natural resources. The emergy evaluation can be used to select a restoration alternative that yields more to the economy with less stress to the environment, by comparing different alternatives with indices expressed in emergy. It can also be used to assess the success of ecosystem restoration projects. Pulsing dynamics in which a slow build-up of production is followed by a frenzied consumption in relatively short time period seems to be a general feature of all systems. Any ecosystem restoration effort, therefore, should consider the whole pulsing cycle for a successful implementation.

Conservation Process of Celadon Janggo Excavated from the Seabed (해저 출토 청자 장고의 보존)

  • Lee, Dahae;Kwak, Eunkyoung;Hwang, Hyunsung
    • Conservation Science in Museum
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    • v.11
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    • pp.53-60
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    • 2010
  • In this paper, key features of an excavated submarine article and general process of its conservation will be introduced. First, the conservation process of removing salt from an excavated submarine article was done by desalting stage, and the X-Ray photographing was done for its inner and outer damage detection. The process of making a restoration mold with the beeswax for the broken part, making restoration material with fillers and grinded broken pieces of earthen ware have similar color and quality, and color matching distinguishable for the naked eye after the whole conservation process have been finished.

A Review on Environmental Restoration of the Waste Landfills (쓰레기매립지의 환경복원)

  • Kim, Kee Dae;Lee, Eun Ju
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.6 no.6
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    • pp.56-71
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    • 2003
  • Waste landfills have been the center of environmental problems and they must be restored due to environmental pollution, disgusting landscape, and cost of management. It is suggested that they be recycled urban space as cities expand. Specially, nonsanitary waste landfills which have no pollution prevention facilities cause serious problems. Restoring the landfills as parks and golf courses, so on makes more benefits because of cheap use land, closeness to urban area, flat topography applicable to parks and golf courses, and high land values after restoration and the changes to local recreation sites. Restoration of waste landfills is a complex, costly, and interdisciplinary work. But, the waste landfill is a manmade ecosystem. Control, restoration and postmanagement of waste landfills are very important problems. The role of vegetation prevents soil erosion, reduces soil water storage, and obstructs leachate seepage. Early restoration makes derelict lands into man park artificially geared to soil, vegetation, landforms and hydrology. But, Ideal restoration is to make stable ecosystem nature-friendly and compatible with surrounding landscape without more management. Landscape is structured hierarchically with patches and stands as small components and forms forest as large components. Therefore, landscape formation of the waste landfills needs much restoration process. There are many ecological restoration techniques for the waste landfills. Those are divided into artificial and natural methods. The artificial method is anthropogenic plantings while the natural method is to trigger and use succession processes. The most important thing in the restoration of waste landfills is to consider the final restoration objectives of each waste landfill. According to these objectives, the depth of covering layer, planting degree, and structural design should be determined. The effective restoration methods should be selected of artificial and natural options.

Research on the Utilization of the Native Plants in Restoration of Stream-Side in Rural Areas (농촌마을 소하천변 식생복원을 위한 자생식물 선정에 관한 연구)

  • Kang, Bang-Hun;Lee, Sang-Hwa
    • Journal of Korean Society of Rural Planning
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    • v.12 no.4 s.33
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    • pp.83-88
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    • 2006
  • Recently, management and restoration efforts using the plants promote the disturbed habitats such as a set-asides or field boundaries. But, side effects are coming out because of using the exotic plants in restoration process. This study was conducted to select the native plant species used for restoration through the vegetation survey and plant community analysis at small stream-side in rural villages. We surveyed at two small stream-sides in open field and high land area in 2005 as a case study. Total 126 species was found at small stream side in open field area. As the result of important value' calculation, Persicaria thunbergii 23.0%, Humulus japonicus 18.6%, Phragmites communis 4.4%, Bromus japonicus 4.2%, and Rosa multiflora 3.4% were in the order of important value. Total 92 species were found at small stream side in high land area. As the result of important value' calculation, Dactylis glomerata 16.1%, Artemisia princeps var. orientalis 11.0%, Persicaria thunbergii 10.9%, Humulus japonicus 9.3%, Phragmites japonica 5.2% and Phragmites communis 3.5% were in the order of important value. We selected some plant species to use in restoration after due consideration of problems of exotic plant and high coverage and density species, and ecological process; Persicaria thunberii, Phragmites communis, Bromus japonicus, Rosa multiflora, Equisetum arvense, Digtaria sanguinalis, Impatiens textori, and Artemisia princeps var. orientalis in open field stream-side, and Artemisia princeps var. orientalis, Persicaria thunbergii, Phragmites japonica, Phragmites communis, Artemisia selengensis, Panicum bisulcatum, Rorippa indica, and Equisetum arvense at hghland stream-side. We will verify the selected native plants and plan the utilization of the native plants in restoration at stream-side in rural village.

Traditional Agricultural Landscape as ail Important Model of Ecological Restoration in Japan

  • Toshihiko, Nakamura
    • The Korean Journal of Ecology
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    • v.25 no.1
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    • pp.19-24
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    • 2002
  • The traditional Japanese agricultural landscape, In which a set of varied land-use patches functions as a sustainable ecosystem landscape unit, not only provides the local people tilth a stable food supply, but also offers a variety of habitats to many species of wildlife. Therefore, remaining natural habitats including those in the traditional agricultural landscape should be maintained whenever possible. In addition, restoration work should be implemented in areas where the natural habitat has been destroyed or severely degraded by human activities. This basic approach to the natural environment is a combination of maintenance and restoration. Types of maintenance and restoration can be classified into three categories according to the countermeasures employed: preservation, conservation and protection types of maintenance, and improvement, reconstruction and creation types of restoration. Four steps are proposed for ecological restoration and maintenance of a target area: exploration, diagnosis, prescription and care. In this process, a model for approaching the goal is important. One of the most important models should center on the traditional agricultural landscape involving a sustainable farming ecosystem. It is necessary to protect traditional landscapes and ecosystems from the degrading impact of urbanization and industrialization, as well as to enhance efforts at restoration.

A Consideration on the Approach of Urban Stream Landscape Restoration - The Case of the Chungkye Stream Restoration Project - (도시하천경관복원 접근방법에 관한 고찰- 청계천 복원사업을 사례로 -)

  • Shin Dong-Hoon;Lee Kyoo-Seock
    • Journal of the Korean Institute of Landscape Architecture
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    • v.32 no.4
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    • pp.39-48
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    • 2004
  • In the 1960s, polluted urban streams were covered and paved in concrete. Rivers became sewers buried under road. As a result, wildlife habitat was lost and the open stream space was gone. In the 1990s, there was a movement for restoring urban streams to enhance the quality of life of inhabitants. Chungkye Stream, whose covering began from early 1950s and ended in 1977, is now in the process of restoration together with the Central Business District (CBD) Redevelopment Plan. However, as the construction proceeds, several problems were raised, and serious controversies resulted. Therefore, this study aims to investigate the validity of the approach of the Chungkye Stream Restoration Project through a literature survey and a site survey, and to present the improved alternative. Ultimately, the study aims to contribute to present references or guidelines for similar urban stream restoration projects. The Chungkye Stream Restoration Project has some of the following problems. First, the construction should be done based on the long-term urban redevelopment plan. Second, the construction period should be extended to restore urban streams. Third, the cultural asset conservation plan should be implemented. In order to fulfill the anticipated purpose, the above mentioned problems need to be solved.

Mistakes Made, Lessons Learned: The Eulsukdo Wetland Restoration Program

  • Lineman, Maurice J.M.;Do, Yuno;Kim, Ji-Yoon;Joo, Gea-Jae
    • Journal of Environmental Science International
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    • v.23 no.8
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    • pp.1523-1536
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    • 2014
  • Restoration is the process of reducing or reversing damage to an ecosystem so that it can function in its original manner. However, many restoration programs do not achieve this. In the Nakdong Estuary, the largest migratory nesting site in the center of the East Asian-Australasian flyway, an estuarine barrage was constructed in the 1980s that required site restoration following its completion in 1987 and the expansion of several large industrial complexes(Noksan and Jangrim) and a residential development(Myeongji). The goal of the restoration was to restore the function of the wetland to its pre-disturbance state. To achieve this, a restoration program was designed consisting of three stages. The first stage(1993-1995), saw the construction of three artificial wetlands(Shinhori, Daemadeung, and Eulsuk), the second(2003-2005) involved the dredging and returning of farmed lands to their natural state, and the third(2008-2012) focused on the rehabilitation and vegetation development of the wetlands. However, the project has not achieved all of the desired goals, and it is an example of the lapses in ecological restoration following anthropogenic disturbance. Issues that resulted in an incomplete restoration included the timing of the stages, noncompliance with the restoration plan, not directly monitoring the restoration or continuing the monitoring following completion of the development project, and the political subversion of the restoration plan. For the success of the restoration plan, it is necessary to avoid mistakes such as inconsistent monitoring, unequal levels of stakeholder involvement, and political interference.

3 keys for successive direct esthetic restoration (성공적 직접 심미 수복을 위한 3가지 열쇠)

  • Cho, Sang Ho
    • The Journal of the Korean dental association
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    • v.54 no.1
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    • pp.16-20
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    • 2016
  • There is a difficulty for many practioner in anterior direct restroation with composit resin. Because its result is various according to patient, a practioner have a fear about that unpromisable result. Moreover in esthetic region, there is difference in satisfaction by patient character. That is one of difficulty in this practice. But if we make a manual for parctice it will be easier. So I will summarize the process and things to note in direct anterior composite resin restoration.

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