• Title/Summary/Keyword: Environmental control systems

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The impact of corrosion on marine vapour recovery systems by VOC generated from ships

  • Choi, Yoo Youl;Lee, Seok Hee;Park, Jae-Cheul;Choi, Doo Jin;Yoon, Young Soo
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.11 no.1
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    • pp.52-58
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    • 2019
  • Marine emissions of Volatile Organic Compounds (VOCs) have received much attention because the International Maritime Organization (IMO) requires the installation of vapour emission control systems for the loading of crude oils or petroleum products onto ships. It was recently recognised that significant corrosion occurs inside these vapour emission control systems, which can cause severe clogging issues. In this study, we analysed the chemical composition of drain water sampled from currently operating systems to investigate the primary causes of corrosion in vapour recovery systems. Immersion and electrochemical tests were conducted under simulated conditions with various real drain water samples, and the impact of corrosion on the marine vapour recovery system was carefully investigated. Moreover, corrosion tests on alternative materials were conducted to begin identifying appropriate substitutes. Thermodynamic calculations showed the effects of environmental factors on the production of condensed sulphuric acid from VOC gas. A model of sulphuric acid formation and accumulation by the characteristics of VOC from crude oil and flue gas is suggested.

Smart Dairy Management System Development Using Biometric/Environmental Sensors and Farm Control Gateway (생체 환경 정보 센싱 모듈 및 농장 제어 게이트웨이를 이용한 스마트 낙농 관리 시스템 개발)

  • Park, Yongju;Moon, Jun
    • IEMEK Journal of Embedded Systems and Applications
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    • v.11 no.1
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    • pp.15-20
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    • 2016
  • Recently, the u-IT applications for plants and livestock become larger and control of livestock farm environment has been used important in the field of industry. We implemented wireless sensor networks and farm environment automatic control system for applying to the breeding barn environment by calculating the THI index. First, we gathered environmental information like livestock object temperature, heart rate and momentum. And we also collected the farm environment data including temperature, humidity and illuminance for calculating the THI index. Then we provide accurate control action roof open and electric fan in of intelligent farm to keep the best state automatically by using collected data. We believed this technology can improve industrial competitiveness through the u-IT based smart integrated management system introduction for industry aversion and dairy industries labor shortages due to hard work and old ageing.

Dynamic behavior control of a collective autonomous mobile robots using artificial immune networks (인공면역네트워크에 의한 자율이동로봇군의 동적 행동 제어)

  • 이동욱;심귀보
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.124-127
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    • 1997
  • In this paper, we propose a method of cooperative control based on immune system in distributed autonomous robotic system(DARS). Immune system is living body's self-protection and self-maintenance system. Thus these features can be applied to decision making of optimal swarm behavior in dynamically changing environment. For the purpose of applying immune system to DARS, a robot is regarded as a B lymphocyte(B cell), each environmental condition as an antigen, and a behavior strategy as an antibody respectively. The executing process of proposed method is as follows. When the environmental condition changes, a robot selects an appropriate behavior strategy. And its behavior strategy is simulated and suppressed by other robot using communication. Finally much simulated strategy is adopted as a swarm behavior strategy. This control scheme is based on clonal selection and idiotopic network hypothesis. And it is used for decision making of optimal swarm strategy.

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Analysis of Small reservoir system by Flood control ability augmentation (치수능력 증대에 따른 저수지시스템 분석)

  • Park Ki-Bum;Lee Soon-Tak
    • Journal of Environmental Science International
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    • v.14 no.11
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    • pp.995-1004
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    • 2005
  • As a research establish reservoir safety operation for small dam systems. This study presents hydrologic analysis conducted in the Duckdong and Bomun dam watershed based on various rainfall data and increase inflow. Especially the Duckdong dam without flood control feature are widely exposed to the risk of flooding, thus it is constructed emergency gate at present. In this study reservoir routing program was simulation for basin runoff estimating using HEC-HMS model, the model simulation the reservoir condition of emergency Sate with and without. At the reservoir analysis results is the Duckdong dam average storage decrease $20\%$ with emergency gate than without emergency gate. Also, the Bomun dam is not affected by the Duckdong flood control augmentation.

A Fundamental Study on the Development of Irrigation Control Model in Soilless Culture of Cucumber (양액재배 오이의 급액제어모델 개발에 관한 기초연구)

  • 남상운;이남호;전우정;황한철;홍성구;허연정
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 1998.10a
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    • pp.224-229
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    • 1998
  • This study was conducted to develop the simple and convenient irrigation control model which can maintain the appropriate rates of irrigation and drainage of nutrient solution according to the environmental conditions and growth stages in soilless culture of cucumber. In order to obtain fundamental data for development of the model, investigation of the actual state of soilless culture practices was carried out. Most irrigation systems of soilless culture were controlled by the time clock. Evapotranspiration of cucumber in soilless culture was investigated and correlations with environmental conditions were analyzed, and its prediction model was developed. A irrigation control model based on the time clock control and there were considered seasons, weather conditions, and growth stages was developed. Applicability of the model was tested by simulation. Drainage rates of irrigation system controlled by conventional time clock, integrated solar radiation, and the developed model were 61%, 20%, and 32%, respectively in cucumber perlite culture.

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Robust optimization of a hybrid control system for wind-exposed tall buildings with uncertain mass distribution

  • Venanzi, Ilaria;Materazzi, Annibale Luigi
    • Smart Structures and Systems
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    • v.12 no.6
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    • pp.641-659
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    • 2013
  • In this paper is studied the influence of the uncertain mass distribution over the floors on the choice of the optimal parameters of a hybrid control system for tall buildings subjected to wind load. In particular, an optimization procedure is developed for the robust design of a hybrid control system that is based on an enhanced Monte Carlo simulation technique and the genetic algorithm. The large computational effort inherent in the use of a MC-based procedure is reduced by the employment of the Latin Hypercube Sampling. With reference to a tall building modeled as a multi degrees of freedom system, several numerical analyses are carried out varying the parameters influencing the floors' masses, like the coefficient of variation of the distribution and the correlation between the floors' masses. The procedure allows to obtain optimal designs of the control system that are robust with respect to the uncertainties on the distribution of the dead and live loads.

Field Survey of Structural and Environmental Characteristics of Pig Houses in the Central Provinces in Korea (우리나라 중부지방 돈사의 구조 및 환경실태조사)

  • 최홍림;송준익;김현태
    • Journal of Animal Environmental Science
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    • v.5 no.1
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    • pp.1-15
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    • 1999
  • The structural and environmental characteristics of typical pig houses in different growth phases were surveyed and analyzed. Based on the data for thirty six selected farms in four provinces, Gyonggi-do, Gangwon-do, Choongnam, and Chonbook, in Central Korea, the goal is to eventually establish standard pig houses of sow and litter, nursery pigs, and growing-finishing pigs. The survey included farm scale, production specialization, structural dimensions of the houses and their ventilation systems, cooling and heating systems, and floor and pit systems related to manure collection. The survey showed 90∼99% of growing-finishing curtain installation rate was lower by 10∼20%. The sidewall curtain system, although popular, is not well insulated which leads to excessive heating costs in winter. Regarding flooring and manure collection system of the house, there was quite a lot variability among provinces, with 30∼80% of the houses installing scraper systems with concrete-slat floors in comparison with 30∼60% using a slurry system. Gangwon-do and Choongbook Chungwoo-goon are the predominant regions that installed a scraper system. A general trend toward enlargement and enclosure of pig houses for all growth phases was gaining popularity in most regions in recent years. A steady shift to three site production from a lumped system was also observed to prevent a disease transfer. The structural design of a standard pig house with its environmental control systems including ventilation and heating/cooling system was suggested for further validation study. In-depth analysis of the survey data is presented in the Results and Discussing section.

A Critical Analysis on the Architectural Education in Korea from the view of International Accrediting Criteria (국제적(國際的) 건축(建築) 전문교육(專門敎育) 인증기준(認證基準)에서 본 한국(韓國) 건축교육(建築敎育)의 현황분석(現況分析))

  • Ryu, Jeon-Hee;Rieh, Sun-Young
    • Journal of architectural history
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    • v.8 no.3 s.20
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    • pp.75-89
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    • 1999
  • Under the WTO system, global standardization of professionalism in architecture practice calls for transformation of curriculum in architectural education in Korea. This paper compares the curriculum standards of international accrediting authorities such as NAAB and RIBA based on UIA accord which defines fundamental knowledge and abilities of an architect. As a result this paper extracts 51 achievement oriented criteria of architectural education in Korea. It can be categorized as communication, design, cultural context(history and theory, human behavior and social aspects), technical systems(structural systems, environmental control systems, construction material and assemblies) and practice(project process, project economics and business management, laws and regulations). Based on this recommended Korean curriculum standards, current curriculum is analyzed focusing on the 5 architectural programs in Seoul. Through this analysis, it became clear that some area - social and economic aspects in architecture, sustainability in architecture, understanding and selection of construction material, assemblies and environmental control system, recycling of existing building, professional liability, professional rules of conduct, project economics and project management - need to be covered and emphasized to meet the international standards in professional education in architecture. The result in this paper will be used as a basic data in the process of finding the direction of restructuring curriculum for professional architectural education in Korea.

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Odor Emission from Sediments in Sewer Systems and Odor Removal using an Electrolytic Oxidation Process (하수관거에 퇴적된 유기물에 의한 악취 발생과 산화전리시스템을 이용한 악취 저감)

  • Ahn, Hae-Young;Shin, Seung-Kyu;Song, Ji-Hyeon
    • Journal of Korean Society for Atmospheric Environment
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    • v.27 no.6
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    • pp.703-710
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    • 2011
  • Odor emission from domestic sewer systems has become a serious environmental problem. An investigation on a sewer manhole revealed that anaerobic decay of sediment organic matters (SOMs) and related declines of oxidation reduction potential (ORP) in the sediment layer were the main reason of the production of volatile sulfur compounds. In addition, as the anaerobic decaying period continued, the odor intensity rapidly increased with increasing concentrations of $H_2S$ and dimethyl sulfide. As a feasible method to control SOMs and to minimize odor emission potentials, an electrolytic oxidation process has been employed to the sediment sludge phase. In this study, voltages applied to the electrolytic oxidation process were varied as a main system parameter, and its effects on odor removal efficiencies and reaction characteristics were investigated. At the applied voltages greater than 20 V, the system efficiently oxidized the organic matter, and the ORP in the sludge phase increased rapidly. As a consequence, the removal efficiency of hydrogen sulfide was found to be >99% within 60 minutes of the electrolytic oxidation. Overall, the electrolytic oxidation process can be an alternative to control odor emission from sewer systems, and a threshold input energy needs to be determined to achieve effective operation of the process.

A Study on the Factors Affecting the Use and Satisfaction of Internet Ticketing Systems (인터넷 티켓팅 시스템의 사용과 만족에 영향을 미치는 요인)

  • Woo, Sung-Hwa;Kim, Kyung-Kyu;Chang, Hang-Bae;Shin, Ho-Kyoung
    • Asia pacific journal of information systems
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    • v.17 no.3
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    • pp.1-24
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    • 2007
  • With the development of information technology (IT), various information systems (IS) such as Web-based systems and mobile systems have appeared utilizing different technologies. However, recent studies on IS use and user satisfaction rarely account for technological differences among IS and environmental characteristics where IS are intended to be used. The purpose of this research is to investigate the determinants of the use of Web-based ticketing systems for cultural activities and to empirically validate their relationships. Environmental psychology suggests that human beings respond to external stimuli from environments with their emotions, and their emotional states influence human actions, e.g., IS use in this research. Applying environmental psychology to the use of Web-based systems in the culture and entertainment industry, we propose that web site characteristics first influence a user's internal state of mind (i.e., flow) and then the flow state influences the IS use. Studies related to the state of flow collectively affirm the key role played by the flow construct in shaping individual attitudes and behaviors toward IS. Users' flow states are captured by their shopping enjoyment, perceived behavioral control, and the level of concentration on the IS use. Referring to social presence theory, we have included such web site characteristics as content quality, context of web site, and community quality. In our research model, a second order construct is utilized to represent web site quality, because flow theory suggests that holistic experiences with web-based systems (rather than individual characteristics of the web site) are important in explaining the IS use. Further, we have included trust as another important factor influencing the IS use since business transactions on the web encompass higher uncertainty comparing to offline transactions. In order to test our hypotheses, we have conducted an online survey which results in 1,141 valid responses in the final sample. The data were collected from respondents who have experiences in Internet ticketing systems. Although it was a convenient sample, the sample represents a wide variety of user demographics. Validity and reliability of the research instrument were tested and research hypotheses were examined using PLS Graph 3.0. The results indicate that web site characteristics significantly influence the level of user concentration, user's enjoyment in shopping, and perceived behavioral control. Further, the use of Internet ticketing systems is influenced by users' flow states and trust in the web channel. User satisfaction is turned out to be affected by the use of Internet ticketing systems. Unlike extant research on the relationship between web site characteristics and its use, our study has found that, in the culture and entertainment industry, the impact of web site characteristics on IS use is mediated by a user's flow state. This finding has a practical implication that web site design should include as many features that enhance shopping enjoyment and concentration. Other practical implications of these findings and future research implications are also discussed.