• 제목/요약/키워드: economic plants

검색결과 638건 처리시간 0.027초

외부 환경적 요인에 의한 파이프랙 구조물의 열적 거동 (Thermal Behavior of a Pipe-Rack Structure Subjected to Environmental Factors)

  • 이종한;이종재;김성연
    • 한국건설순환자원학회논문집
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    • 제3권2호
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    • pp.165-170
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    • 2015
  • 파이프랙 구조물은 고온 고압의 파이프를 지지하며 플랜트의 운전 안전성을 좌우하는 매우 중요 구조물이다. 따라서, 파이프랙 구조물의 손상은 산업 전반에 부정적인 파급효과를 가져옴과 동시에 인명 및 재산상의 막대한 피해까지 가져오게 된다. 특히, 파이프랙 구조물은 외부환경에 노출되어 있어, 구조물의 적절한 설계 및 유지관리를 위하여 환경적 영향에 의한 거동 특성을 평가할 필요가 있다. 따라서, 가장 널리 설계되어지는 하나의 파이프랙 구조물을 대상 구조물로 선정하여 열-구조 연성해석을 실시하여 파이프랙 구조물의 온도분포와 열응력을 평가하였다. 외부 환경적 요인으로는 국내의 여수지역과 중동의 사우디 지역을 고려하여 파이프의 운전조건과 함께 외부환경 영향인자에 대한 고려 필요성을 검증하였다.

보호지역 관리를 위한 생물다양성 평가 (The biodiversity representation assessment in South Korea's protected area network)

  • 최혜영;;주우영;권혁수
    • 한국환경복원기술학회지
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    • 제23권1호
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    • pp.77-87
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    • 2020
  • National parks and other protected areas often do not adequately protect national biodiversity because they were originally created for socio-economic and/or aesthetic values. The Korean government has committed to expanding the extent of protected areas to fulfill its commitments to the Aichi Biodiversity Convention. To do so, it is necessary to quantify the current levels of biodiversity representation within existing protected areas and to identify additional conservation needs for vulnerable species and ecological systems. In this study, we assess the proportion of species ranges found in South Korea's protected areas, for the species documented in the 3rd National Ecosystem Survey. We modeled the range distribution of 3,645 species in the following taxonomic groups; plants (1,545 species), mammals (35), birds (132), herptiles (35), and insects (1,898) using the MaxEnt species distribution model and calculated how much of each species' range is within protected areas. On average, 17.4% of plant species' ranges are represented in protected areas, while for mammals and insects an average 12.0% is currently conserved. Conservation representation for herptiles averages 9.3%, while it is 8.6% for birds. Although large proportions of species that have restricted distributions should be represented in protected areas, 17 plant species, two insects (Parnassius bremeri and Lasioglossum occidens), and one bird species (Phylloscopus inornatus) with ranges smaller than 1,000 ㎢ have less than 10% of their ranges within protected areas. Establishing specific conservation goals such as the protection of endangered species or vulnerable taxonomic groups will increase the efficiency of the biodiversity conservation strategies. In addition, lowland coastal areas are critical for biodiversity conservation because the protected areas in South Korea are mainly composed of high mountainous areas.

Efficacy of Three Different Plant Species for Arsenic Phytoextraction from Hydroponic System

  • Tiwari, Sarita;Sarangi, Bijaya Ketan;Pandey, Ram Avatar
    • Environmental Engineering Research
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    • 제19권2호
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    • pp.145-149
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    • 2014
  • Arsenic (As) is one of the heavy metals which causes acute bio-toxicity even at low concentration and has disastrous effect on environment. In some countries, As contamination has become alarming and increasing day by day as consequences of unsustainable management practices. Many existing physical, chemical and biological processes for As removal from water system are not feasible due to techno-economic limitations. The present study highlights the scope of biological strategy for As removal through phytoextraction. Arsenic uptake and accumulation in the biomass of three plant species and their As tolerance abilities have been investigated to develop an efficient phytoextraction system in combination of these plant species. Three non-crop plant species, Pteris vittata; Mimosa pudica, and Eichhornia crassipus were treated with 0-200 mg/L As in liquid nutrient solution for 14 days. P. vittata accumulated total 9,082.2 mg (8,223 mg in fronds) As/kg biomass and Eichhornia total 6,969 mg (4,517 mg in fronds)/kg biomass at 200 mg/L As concentration, respectively. Bioaccumulation factor (BF) and translocation factor (TF) were estimated to differentiate between excluders, accumulators and accumulation in above ground biomass. Pteris and Eichhornia have highest BF (67 and 17) and TF (64 and 3), respectively. In contrast, Mimosa accumulated up to 174 mg As/kg plant biomass which is low in comparison with other two plants, and both BF and TF were ${\leq}1$. This study reveals that Pteris and Eichhornia are As hyperaccumulator, and potential candidates for As removal from water system.

월남국 고콩지구 수리 개발 기본 조사 (The Engineering Services on the Go Cong Water Control Project in Vietnam)

  • 조용칠
    • 한국농공학회지
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    • 제13권4호
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    • pp.2471-2478
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    • 1971
  • Go Cong Water Control Project was conducted on its preliminary survey and design by Agricultural development Corporation for the Korean Government, an Executing Agency, and Directorate of Irrigation and Rural Engineering of the Ministry of Land Reform, Agriculture and Fishery Development for the Vietnamese Government, a cooperation Agency, under Korean and Vietnamese Economic and Technical Cooperation Program. The main purposes of the project are aimed at the improvements of irrigation and drainage, and salt water prevention of the Go Cong area located at northern part of the Mekong Delta. All the works from field survey through design to preparing reports were carried out by ADC alone and recently Korean Government submitted the relevant reports to vietnamese Government through official channel. The contents of the project are summarized as following: 1. The project comprises irrigation, drainage and salt water prevention facilities on the benefited area of about 55,000 hectares, covering Go Cong and Dinh Tuong(My Tho) Provinces and it will be possible to cultivate rice cropping twice a year, irrigating all the area in the dry season; 2. With completion of this project, annual production of rough rice and vegetables are anticipated to increase by 222,600 .T. and 142,600 M.T. respectively and the internal rateof return stants at 26 per cent, applying for the exchange rate of US $ 1 to VN $ 275. 3. Total investments required for the project are estimated at US $ 56,394,000 of which actual construction cost is estimated at US $ 39,183,000. The project has planned to be d to be developed by four stages, taking bout 7 years. 4. The project needs for three places of pumping plants. 57Km of feed and main irrigation canals, 81Km of drainage channels, 97Km of dike, 23 places of sluices and navigation locks, etc.

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VHDL을 이용한 구동 시간 설정 밸브 전동 엑추에이터 제어 장치 개발에 관한 연구 (A Study on the Development of Electric Actuator Control Device for Driving Time Setting Valve Using VHDL)

  • 강대국;최영규
    • 한국정보전자통신기술학회논문지
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    • 제13권5호
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    • pp.452-459
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    • 2020
  • 전동 엑추에이터는 사용자의 명령 입력 신호(열림/닫힘/정지)를 받아 엑추에이터 내부의 각종 센서(밸브의 위치, 회전력, 모터의 상태 등)들의 상태를 확인하고 모터를 정/역 제어하여 밸브를 개폐하고 엑추에이터(밸브)의 현재 상태를 출력하는 장치로 댐, 발전소, 상하수도 시설, 송유관 시설 등 다양한 분야에서 사용하는 장치이다. 전동 엑추에이터가 발전소 등에 설치되어 가동 중 문제가 발생할 경우 경제적으로 큰 손실이 발생할 수 있으므로 시스템의 신뢰성이 매우 중요하다. 본 연구에서는 전동 엑추에이터의 안전성을 높이기 위해 소프트웨어적으로 발생할 수 있는 신뢰성 문제를 하드웨어적으로 ON/OFF 시간 설정이 가능한 전동 엑추에이터 컨트롤 장치 개발을 진행하였다. 또한 전동 엑추에이터 제어 장치 개발 환경은 Xilinx 사의 Spartan7 FPGA와 Altium 툴을 활용하여 개발하였다.

경관선호도의 인지인자에 관한 연구 (A Study on Cognitive Factors for the Landscape Preference)

  • 양병이
    • 한국조경학회지
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    • 제17권3호
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    • pp.9-20
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    • 1990
  • The objective of this study is to test the applicability of the Information processing model suggested by Kaplan to the preferences of Korean people as well as to investigate the preference patterns of Korean people and the influencing factors on Korean preferences for the landscape. Photo - questionnaire survey was conducted twice to collect the data concerning the landscape preferences. The samples of the first survey were selected from the citizens of Seoul and the students of Seoul National University. The first survey focused on the preference patterns of Korean people while the emphasis of the second survey was given to the test of information processing model and the influencing factors on the preferences of Korean people. The samples of second survey were also selected from the students of Seoul National University. The photos in the photo - questionnaire for the first survey included the scenes representing both three landscape styles(Korean, Japanese and Western styles)and three landscape qualities such as the layout of space, the use of landscape plants and the use of stones and rocks. For the second survey, four informational factors such as complexity, coherence, legibility and mystery were selected for inclusion in the photos of photo - questionnaire. Respondents for both survey were asked to respond their preferences on the five - point Likers scale. The results of the study suggested that four informational factors influence significantly the preferences of Korean students. The study indicated that both the citizens of Seoul and the students of Seoul National University prefer water and vegetation to rock among the contents of landscape. Among the landscape styles, Japanese landscape style was most preferred and Western landscape style was more preferred than Korean traditional landscape style. In addition to informational factors, it was found that the contents of landscape and landscape style were also major influencing factors on the landscape preferences. The socio - economic backgrounds of respondents such as age, foreign travel experience, income, residency before the age 14, familiarity and respondent's experties in landscape architecture seemed to Influence the landscape preferences.

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온실가스 대량감축을 위한 $CO_2$ 지중저장의 기술 동향 (Trends of Underground $CO_2$ Storage Technology for the Large Scale Reduction of GHG)

  • 채광석;이상필;윤성욱;마츠오카 토시후미
    • 터널과지하공간
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    • 제20권5호
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    • pp.309-317
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    • 2010
  • CCS는 "이산화탄소의 포집 및 저장 기술"의 약어로서, 화석연료를 사용하는 화력발전소, 제철소 등에서 대규모로 배출하는 이산화탄소를 저감하기 위한 방법이다. CCS는 화석연료의 연소에서 발생되는 가스를 포집하여, 압축, 수송, 주입의 프로세스를 거처서 깊은 지하에 영구적으로 저장한다. CCS를 기존 화력발전소에 적용시에는 CCS 설비가 없는 발전소에 비해 약 80~90%의 이산화탄소를 줄일 수 있다. IPCC의 보고서에 의하면, CCS는 2010년까지 이산화탄소 총 감축량의 10~55%를 감당할 수 있는 경제적 잠재력이 있다고 보고되고 있다. 본 고에서는 CCS 기술의 해외 적용 사례 및 관련 핵심 기술 동향에 대해 간략하게 소개하고자 한다.

문화와 과학의 융합적 관점에서 본 전통음식의 역사 및 미래 (Traditional Foods: Historical Perspectives and Future Prospects)

  • 김희섭
    • 한국식생활문화학회지
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    • 제30권1호
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    • pp.1-7
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    • 2015
  • Traditional cuisine reflects cooking traditions shaped by political, economic, social, cultural, and environmental conditions characterized by authenticity and uniqueness. Traditional food is not only a part of our cultural heritage but also a knowledge resource. Application of food science and technology in Korean traditional foods was reviewed from six points of view, including food preservation, fermentation, changes in food materials, utilization of food functionality, and packaging and development of cooking appliances. Books from disparate times were chosen in order to cover a wide range of materials from the past to the present. Food preservation and fermentation techniques were applied to various food materials. Combination of science and skills contributes to the accessibility of diverse food materials and better quality foods. Koreans use assorted and resilient plants, which have an abundance of functional substances such as food materials. Among cooking appliances, microwave oven and refrigerator are the most innovative products with huge influences on food eating patterns as well as lifestyle. Packaging effectively reduces post-harvest preservation losses, and better packaging has technical improvements for storage and distribution. Kimchi was chosen as an example in order to study technology from the past to the present. Availability of Kimchi cabbage, enrichment of functional ingredients, identification of useful microbial species, standardization of recipe for commercialization, prevention of texture softening, introduction of salted Kimchi cabbage and Kimchi refrigerators, and packaging were reviewed. The future of traditional foods in the market will be competitive. First, traditional foods market should be maintained to protect the diversity of food materials. Secondly, tailored foods for individuals should be considered using foods with functional properties. Information on health benefits would provide insights into health and traditional food products. Third, speedy transfer of new technology to the traditional food industry is needed to ensure food quality production and new opportunities in the market. Fourth, safety of traditional foods should be ensured without sacrificing the essential characteristics of culturally important foods. Improvement of logistics, distribution, and facility should be carried out. As demand for convenience foods increases, traditional foods should be developed into products.

중국 현대 상업건축 실내 공간의 문화적 표현특성에 대한 사례연구 (A Case Study on the Characteristics of Cultural Expression in Contemporary Commercial Architecture Design in China)

  • 위더셩
    • 한국콘텐츠학회논문지
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    • 제19권10호
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    • pp.32-44
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    • 2019
  • 본 논문은 문화적 표현특성을 기초로, 중국 6개 최대 도시의 대표적인 현대 상업건축 공간 사례에 대해 비교분석을 진행한 것이다. 본 논문에서는 중국 현대 상업용 건물의 실내공간 문화가 지속 가능한 발전을 이루기를 기대한다. 6개 사례를 각각 문화의 전통성, 지역성, 대중성, 기술성, 생태성 5가지 관점에서 분석했고 결과는 다음과 같다. 첫째, 문화의 전통성은 상업건축의 실내공간에서 구체적인 지역의 전통적 요소를 중시하도록 요구한다. 둘째, 문화의 지역성은 상업건축의 실내공간이 있는 곳의 경제발전 정도, 역사적 내막, 지리적 환경조건, 기후 등 사회와 자연환경 요인과 밀접하게 연관되어 있다. 셋째, 문화의 대중성은 상업건축의 실내공간을 통해 대중문화의 통합화, 레저화, 오락화, 기호화를 나타낸다. 넷째, 문화의 기술성은 현지의 문화성을 가진 시공 방법, 구조 형식, 재료를 상업건축 실내공간에 통합하는 것이다. 다섯째, 문화의 생태성은 상업건축의 실내공간에 식물을 배치하고, 건강하고 쾌적하며 안전한 환경을 만드는 것이다.

CONDITION MONITORING USING EMPIRICAL MODELS: TECHNICAL REVIEW AND PROSPECTS FOR NUCLEAR APPLICATIONS

  • Heo, Gyun-Young
    • Nuclear Engineering and Technology
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    • 제40권1호
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    • pp.49-68
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    • 2008
  • The purpose of this paper is to extensively review the condition monitoring (CM) techniques using empirical models in an effort to reduce or eliminate unexpected downtimes in general industry, and to illustrate the feasibility of applying them to the nuclear industry. CM provides on-time warnings of system states to enable the optimal scheduling of maintenance and, ultimately, plant uptime is maximized. Currently, most maintenance processes tend to be either reactive, or part of scheduled, or preventive maintenance. Such maintenance is being increasingly reported as a poor practice for two reasons: first, the component does not necessarily require maintenance, thus the maintenance cost is wasted, and secondly, failure catalysts are introduced into properly working components, which is worse. This paper first summarizes the technical aspects of CM including state estimation and state monitoring. The mathematical background of CM is mature enough even for commercial use in the nuclear industry. Considering the current computational capabilities of CM, its application is not limited by technical difficulties, but by a lack of desire on the part of industry to implement it. For practical applications in the nuclear industry, it may be more important to clarify and quantify the negative impact of unexpected outcomes or failures in CM than it is to investigate its advantages. In other words, while issues regarding accuracy have been targeted to date, the concerns regarding robustness should now be concentrated on. Standardizing the anticipated failures and the possibly harsh operating conditions, and then evaluating the impact of the proposed CM under those conditions may be necessary. In order to make the CM techniques practical for the nuclear industry in the future, it is recommended that a prototype CM system be applied to a secondary system in which most of the components are non-safety grade. Recently, many activities to enhance the safety and efficiency of the secondary system have been encouraged. With the application of CM to nuclear power plants, it is expected to increase profit while addressing safety and economic issues.