• Title/Summary/Keyword: 시설 위치

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Experimental Analysis of Nodal Head-outflow Relationship Using a Model Water Supply Network for Pressure Driven Analysis of Water Distribution System (상수관망 압력기반 수리해석을 위한 모의 실험시설 기반 절점의 압력-유량 관계 분석)

  • Chang, Dongeil;Kang, Kihoon
    • Journal of Korean Society of Environmental Engineers
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    • v.36 no.6
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    • pp.421-428
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    • 2014
  • For the analysis of water supply network, demand-driven and pressure-driven analysis methods have been proposed. Of the two methods, demand-driven analysis (DDA) can only be used in a normal operation condition to evaluate hydraulic status of a pipe network. Under abnormal conditions, i.e., unexpected pipe destruction, or abnormal low pressure conditions, pressure-driven analysis (PDA) method should be used to estimate the suppliable flowrate at each node in a network. In order to carry out the pressure-driven analysis, head-outflow relationship (HOR), which estimates flowrate at a certain pressure at each node, should be first determined. Most previous studies empirically suggested that each node possesses its own characteristic head-outflow relationship, which, therefore, requires verification by using actual field data for proper application in PDA modeling. In this study, a model pipe network was constructed, and various operation scenarios of normal and abnormal conditions, which cannot be realized in real pipe networks, were established. Using the model network, data on pressure and flowrate at each node were obtained at each operation condition. Using the data obtained, previously proposed HOR equations were evaluated. In addition, head-outflow relationship at each node was analyzed especially under multiple pipe destruction events. By analyzing the experimental data obtained from the model network, it was found that flowrate reduction corresponding to a certain pressure drop (by pipe destruction at one or multiple points on the network) followed intrinsic head-outflow relationship of each node. By comparing the experimentally obtained head-outflow relationship with various HOR equations proposed by previous studies, the one proposed by Wagner et al. showed the best agreement with the exponential parameter, m of 3.0.

A Numerical Study for Effective Operation of MSW Incinerator for Waste of High Heating Value by the Addition of Moisture Air (함습공기를 이용한 고발열량 도시폐기물 소각로의 효율적 운전을 위한 수치 해석적 연구)

  • Shin, Mi-Soo;Shin, Na-Ra;Jang, Dong-Soon
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.2
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    • pp.115-123
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    • 2013
  • Stoker type incinerator is one of the most popular one used as municipal solid waste (MSW) incineration because, in general, it is quite suitable for large capacity and need no preprocessing facility. Nowadays, however, since the combustible portion of incoming MSW increases together with the decrease of the moisture content due to prohibition of directly burying food waste in landfill, the heating value of waste is remarkably increasing in comparison with the early stage of incinerator installation. Consequently, the increased heating value in incinerator operation causes a number of serious problems such as reduction of waste amount to be burned due to the boiler heat capacity together with the significant NO generation in high temperature environment. Therefore, in this study, a series of numerical simulation have been made as parameters of waste amount and the fraction of moisture in air stream in order to investigate optimal operating condition for the resolution of the problems associated with the high heating value of waste mentioned above. In specific, a detailed turbulent reaction flow field calculation with NO model was made for the full scale incinerator of D city. To this end, the injection method of moisturized air as oxidizer was intensively reviewed by the addition of moisture water amount from 10% and 20%. The calculation result, in general, showed that the reduction of maximum flame temperature appears consistently due to the combined effects of the increased specific heat of combustion air and vaporization heat by the addition of water moisture. As a consequence, the generation of NOx concentration was substantially reduced. Further, for the case of 20% moisture amount stream, the afterburner region is quite appropriate in temperature range for the operation of SNCR. This suggests the SNCR facility can be considered for reoperation. which is not in service at all due to the increased heating value of MSW.

A Sustainable Operation Plan for School Gardens - Based on a Survey of Elementary School Gardens in Seoul (학교 텃밭의 지속적인 운영방안에 관한 연구 - 서울특별시 초등학교의 학교 텃밭 실태조사를 바탕으로 -)

  • Choi, I-Jin;Lee, Jae Jung;Cho, Sang Tae;Jang, Yoon Ah;Heo, Joo Nyung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.46 no.4
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    • pp.36-48
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    • 2018
  • This study surveyed 599 elementary schools in Seoul to provide measures for the quantitative expansion and sustainable operation of environmentally-friendly school garden. Of all schools, 161 schools had formed and were operating school gardens. The total area of school gardens was $166,901m^2$ and the mean area was $131.2m^2$ in elementary, junior high and high schools in Seoul. Meanwhile, the total area of school gardens was $65,493m^2$ and the mean area was $363m^2$ in 161 schools that participated in the survey, indicating $1.15m^2$ per student. Of these schools, 11.8% were operating gardens themselves, while 50.3% were operating gardens that had been newly renovated or environmentally improved by institutional support projects after initially managing gardens themselves. According to the locations of school gardens, mixed-type gardening (a combination of school gardening and container vegetable gardening) accounted for 34.8%, followed by school gardening at 32.9%, container vegetable gardening at 29.2%, and suburb community gardening at 3.1%. Those in charge of garden operations were teachers at 51.6%, comprising the largest percentage. Facilities built when forming the garden included storage facilities for small-scale greenhouses and farming equipment at 26.1%, accounting for the largest percentage. No additional facilities constructed accounted for 21.7%. The greatest difficulty in operating gardens was garden management at 34.2%. The most needed elements for the sustainable operation of gardens were improvement in physical environment and the need for hiring a paid garden, each accounting for 32%. The most important purpose for school gardening was creating educational environments (81.6%). The major source for gaining information on garden management was consultation from acquaintances (67.8%). Schools that utilize plant waste from gardens as natural fertilizers accounted for 45.8% of all schools. Responses to the impact of operating school gardens for educational purpose were positive in all schools as 'very effective' in 63.2% and 'effective' in 36.8%. This study was meaningful in that it intended to identify the current status of the operation of school gardens in elementary schools in Seoul, support the formation of school gardens appropriate for each school with sustainable operation measures, implement a high-quality education program, develop teaching materials, expand job training opportunities for teachers in charge, devise measures to support specialized instructors, and propose the need for a garden management organization.

Basic Studies on the Location and Spatial Organization Characteristics of the Seoul Sajikdan (서울 사직단(社稷壇)의 입지(立地)와 공간구성특성(空間構成特性)에 관한 기초연구(基礎硏究))

  • Choi, Seung-Sik;Shim, Woo-Kyung;Yoo, Jong-Ho;Jeon, Hye-Won;Choi, Jong-Hee
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.30 no.1
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    • pp.146-158
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    • 2012
  • This study aims to discussion the characteristics of location and spatial organization of the Seoul Sajikdan that has significance as one of national ceremonial place in Joseon Dynasty to understand its landscape architectural characteristics. To do this, we studied in two ways; review of historical documents and analysis of the present conditions and photographing, research materials about the form of physical structure. Through these ways, the results are as follows. First, in case of construction, Sajikdan took fundamental shape in Tae-jong 16 year(1416), since then it had been changed during Imjin War, reign of Suk-jong, and Japanese Colonial Era. It took present shape through restoration of Seoul Sajikdan in 1998. Second, in case of location, Sajikdan abuts onto southeastern range of Mt. Inwang that is Wubaekho(右白虎) of inner four mountain(內四山) of Hanyang, and it has a topography of west-high-east-low type. Also its territory is up to Maedong elementary school, the office of Sajik-dong, and a Dangun shrine. Third, in case of spatial organization, Sadan and Jikdan are in harmony of Yin-Yang(陰陽) and arranged in the center. As making Yumun and Sinmun(神門) at the center of four side of Yuwon and Juwon(周垣), they show organization of the Five Elements. And subsidiary buildings are thought that its arrangement was considered functional similarity and use convenience. Finally, in case of spatial component, Danyu structures are Sadan and Jikdan that hold a Sajikdaeje(社稷大祭), Yuwon that surround two altars, and Juwon that is outer fence of Yuwon. Architectures are Sajikdan Jeongmun, Sinsil, and Anhyangcheong. Also Prunus yedoensis, Zelkova serrata, Acer palmatum, are planted, but Pinus densiflora was main species and there needs to be replanted suitably to the site.

Development and Application of the High Speed Weigh-in-motion for Overweight Enforcement (고속축하중측정시스템 개발과 과적단속시스템 적용방안 연구)

  • Kwon, Soon-Min;Suh, Young-Chan
    • International Journal of Highway Engineering
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    • v.11 no.4
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    • pp.69-78
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    • 2009
  • Korea has achieved significant economic growth with building the Gyeongbu Expressway. As the number of new road construction projects has decreased, it becomes more important to maintain optimal status of the current road networks. One of the best ways to accomplish it is weight enforcement as active control measure of traffic load. This study is to develop High-speed Weigh-in-motion System in order to enhance efficiency of weight enforcement, and to analyze patterns of overloaded trucks on highways through the system. Furthermore, it is to review possibilities of developing overweight control system with application of the HS-WIM system. The HS-WIM system developed by this study consists of two sets of an axle load sensor, a loop sensor and a wandering sensor on each lane. A wandering sensor detects whether a travelling vehicle is off the lane or not with the function of checking the location of tire imprint. The sensor of the WIM system has better function of classifying types of vehicles than other existing systems by detecting wheel distance and tire type such as single or dual tire. As a result, its measurement errors regarding 12 types of vehicle classification are very low, which is an advantage of the sensor. The verification tests of the system under all conditions showed that the mean measurement errors of axle weight and gross axle weight were within 15 percent and 7 percent respectively. According to the WIM rate standard of the COST-323, the WIM system of this study is ranked at B(10). It means the system is appropriate for the purpose of design, maintenance and valuation of road infrastructure. The WIM system in testing a 5-axle cargo truck, the most frequently overloaded vehicle among 12 types of vehicles, is ranked at A(5) which means the system is available to control overloaded vehicles. In this case, the measurement errors of axle load and gross axle load were within 8 percent and 5 percent respectively. Weight analysis of all types of vehicles on highways showed that the most frequently overloaded vehicles were type 5, 6, 7 and 12 among 12 vehicle types. As a result, it is necessary to use more effective overweight enforcement system for vehicles which are seriously overloaded due to their lift axles. Traffic volume data depending upon vehicle types is basic information for road design and construction, maintenance, analysis of traffic flow, road policies as well as research.

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Characteristics of Pollution Loading from Kyongan Stream Watershed by BASINS/SWAT. (BASINS/SWAT 모델을 이용한 경안천 유역의 오염부하 배출 특성)

  • Jang, Jae-Ho;Yoon, Chun-Gyeong;Jung, Kwang-Wook;Lee, Sae-Bom
    • Korean Journal of Ecology and Environment
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    • v.42 no.2
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    • pp.200-211
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    • 2009
  • A mathematical modeling program called Soil and Water Assessment Tool (SWAT) developed by USDA was applied to Kyongan stream watershed. It was run under BASINS (Better Assessment Science for Integrating point and Non-point Sources) program, and the model was calibrated and validated using KTMDL monitoring data of 2004${\sim}$2008. The model efficiency of flow ranged from very good to fair in comparison between simulated and observed data and it was good in the water quality parameters like flow range. The model reliability and performance were within the expectation considering complexity of the watershed and pollutant sources. The results of pollutant loads estimation as yearly (2004${\sim}$2008), pollutant loadings from 2006 were higher than rest of year caused by high precipitation and flow. Average non-point source (NPS) pollution rates were 30.4%, 45.3%, 28.1% for SS, TN and TP respectably. The NPS pollutant loading for SS, TN and TP during the monsoon rainy season (June to September) was about 61.8${\sim}$88.7% of total NPS pollutant loading, and flow volume was also in a similar range. SS concentration depended on precipitation and pollution loading patterns, but TN and TP concentration was not necessarily high during the rainy season, and showed a decreasing trend with increasing water flow. SWAT based on BASINS was applied to the Kyongan stream watershed successfully without difficulty, and it was found that the model could be used conveniently to assess watershed characteristics and to estimate pollutant loading including point and non-point sources in watershed scale.

A Study on Physical Properties About Velvet Antler of the Elk(Cerus canadensis) (엘크 녹용의 물성 특성에 관한 연구)

  • Sung, S.H.;Han, J.H.;Kim, Y.M.;Kim, B.K.
    • Journal of Animal Environmental Science
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    • v.13 no.3
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    • pp.201-210
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    • 2007
  • In this study, physical properties of Elk antler was investigated to develop the optimum drying and packaging methods for improving the antler quality as well as deal with diversify of demand. After the antler was sliced with 5 mm thickness, and the compressive, shear, and tensile stresses were measured at the center and velvet parts of pre-dried and dried antlers after the contained water rate of the dried antlers was maintained below 10%. The results are as follows. 1. Considering the center of pre-dried antlers, the compressive stresses were $60.73\;g/mm^2$, $145.65\;g/mm^2$, and $260.97\;g/mm^2$, respectively at the upper, middle, and lower parts while $70.67\;g/mm^2$, $811.90\;g/mm^2$, $3,235.52\;g/mm^2$, respectively for velvet layer. Considering the center of dried antlers, the compressive stresses were $190.43\;g/mm^2$, $445.81\;g/mm^2$, and $705.86\;g/mm^2$, respectively at the upper, middle, and lower parts while $734.01\;g/mm^2$, $1,238.40\;g/mm^2$, $4,134.03\;g/mm^2$, respectively for velvet layer. 2. For the pre-dried, the shear stresses were $50.24\;g/mm^2$, $294.44\;g/mm^2$, and $423.47\;g/mm^2$, respectively, and $124.14\;g/mm^2$, $367.69\;g/mm^2$, and $425.86\;g/mm^2$, respectively for the dried antlers. 3. The tensile stresses were $13.59\;g/mm^2$, $62.85\;g/mm^2$, and $112.07\;g/mm^2$, respectively for the pre-dried and $77.24\;g/mm^2$, $175.87\;g/mm^2$, and $184.06\;g/mm^2$, respectively for the dried antlers. 4. In the case of drying antlers, the physical characteristics of the antlers was. changed such as moisture evaporation, contraction, and surface hardening. For the center part, the changes of the physical characteristics were more significant at the lower part while at the upper part for the velvet layer. 5. The stress changes of Elk antlers was shown very remarkably according to growth point. Moreover, the stress was clearly higher at velvet layer part to the center part, base parts compared to the upper parts.

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A Study on the Application of Bushings Fire Prevent Structure to Prevent Fire Spread of Transformer (변압기의 화재확산 방지를 위한 부싱 방화구조체 적용에 관한 연구)

  • Kim, Do-Hyun;Cho, Nam-Wook;Yoon, Choung-Ho;Park, Pil-Yong;Park, Keun-Sung
    • Fire Science and Engineering
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    • v.31 no.5
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    • pp.53-62
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    • 2017
  • Electric power which is the energy source of economy and industries requires long distance transportation due to regional difference between its production and consumption, and it is supplied through the multi-loop transmission and distribution system. Prior to its actual use, electric power flows through several transformations by voltage transformers in substations depending on the characteristics of each usage, and a transformer has the structure consisting of the main body, winding wire, insulating oil and bushings. A transformer fire that breaks out in substations entails the primary damage that interrupts the power supply to houses and commercial facilities and causes various safety accidents as well as the secondary economic losses. It is considered that causes of such fire include the leak of insulating oil resulting from the destruction of bottom part of bushings, and the chain reaction of fire due to insulating oil that reaches its ignition point within 1 second. The smoke detector and automatic fire extinguishing system are established in order to minimize fire damage, but a difficulty in securing golden time for extinguishing fire due to delay in the operation of detector and release of gas from the extinguishing system has become a problem. Accordingly, this study was carried out according to needs of active mechanism to prevent the spread of fire and block the leak of insulating oil, in accordance with the importance of securing golden time in extinguishing a fire in its early stage. A bushings fireproof structure was developed by applying the high temperature shape retention materials, which are expanded by flame, and mechanical flame cutoff devices. The bushings fireproof structure was installed on the transformer model produced by applying the actual standards of bushings and flange, and the full scale fire test was carried out. It was confirmed that the bushings fireproof structure operated at accurate position and height within 3 seconds from the flame initiation. It is considered that it could block the spread of flame effectively in the event of actual transformer fire.

Studies on the Characteristics of Modified Landscape and the Transformational Processes of Ongnyucheon in Changdeok Palace (창덕궁 옥류천의 수경(修景) 특성과 변천과정)

  • Jung, Woo-Jin;Kim, Hyung-Suk;Sim, Woo-Kyung
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.30 no.3
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    • pp.42-56
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    • 2012
  • This study was carried out to investigate the construction characteristics and the landscaping design skill for Wiyiam at Ongnyucheon(玉流川) in the rear garden of Changdeok Palace focusing on constructing technique, space composition and transformational process of the site. The results of this study were summarized as follows; First, Wiyiam of Ongnyucheon was constructed as garden ornament which was modified the huge bedrock into the shape of the mountain. The waterfall of Wiyiam was originally made of torrent which water flowed into the bottom, but it was reconstructed to take the effect of Inak(離落: the method to drop water from high place) by carving rock into square shape at the era of King Gojong(高宗). Second, main characteristics of Wiyiam appeared in Donggwoldo was the hill built up with a square pond and ground at the back of Wiyiam and the profound scenery of mountains and stream from the view of Wiyiam. Also, pavilions such as Soyojeong(逍遙亭), Cheongujeong and Taegeukjeong(太極亭) built in Ongnyucheon seemed to be constructed as the spots to appreciate the view and waterfall sound of Wiyiam. Also the spots were not bounded by the function of creating special water systems such as Cheongujeong pond and Taegeukjeong pond and showed the outstanding landscape design skill to make people feel unusual interest from each spot. On the other hand, this study considered that the evening scenery of Wiyiam, beautiful sound of falling water, unusual water system with beautiful plant materials were landscaped for the function of the psychological peace and stability to the appreciators. Lastly, the extreme change of space composition in Ongnyucheon was assumed as a strategy to improve the existing poor drain environment by confirming that the mountain stream and wall of Soyojeong were removed and drainage in both side of Soyojeong was installed in the 21th year of King Gojong's reign(1884).

Time Change in Spatial Distributions of Light Interception and Photosynthetic Rate of Paprika Estimated by Ray-tracing Simulation (광 추적 시뮬레이션에 의한 시간 별 파프리카의 수광 및 광합성 속도 분포 예측)

  • Kang, Woo Hyun;Hwang, Inha;Jung, Dae Ho;Kim, Dongpil;Kim, Jaewoo;Kim, Jin Hyun;Park, Kyoung Sub;Son, Jung Eek
    • Journal of Bio-Environment Control
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    • v.28 no.4
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    • pp.279-285
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    • 2019
  • To estimate daily canopy photosynthesis, accurate estimation of canopy light interception according to a daily solar position is needed. However, this process needs a lot of cost, time, manpower, and difficulty when measuring manually. Various modeling approaches have been applied so far, but it was difficult to accurately estimate light interception by conventional methods. The objective of this study is to estimate the spatial distributions of light interception and photosynthetic rate of paprika with time by using 3D-scanned plant models and optical simulation. Structural models of greenhouse paprika were constructed with a portable 3D scanner. To investigate the change in canopy light interception by surrounding plants, the 3D paprika models were arranged at $1{\times}1$ and $9{\times}9$ isotropic forms with a distance of 60 cm between plants. The light interception was obtained by optical simulation, and the photosynthetic rate was calculated by a rectangular hyperbola model. The spatial distributions of canopy light interception of the 3D paprika model showed different patterns with solar altitude at 9:00, 12:00, and 15:00. The total canopy light interception decreased with an increase of surrounding plants like an arrangement of $9{\times}9$, and the decreasing rate was lowest at 12:00. The canopy photosynthetic rate showed a similar tendency with the canopy light interception, but its decreasing rate was lower than that of the light interception due to the saturation of photosynthetic rate of upper leaves of the plants. In this study, by using the 3D-scanned plant model and optical simulation, it was possible to analyze the light interception and photosynthesis of plant canopy under various conditions, and it can be an effective way to estimate accurate light interception and photosynthesis of plants.