• 제목/요약/키워드: field pilot experiment

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Validation of Ship Detection by the RADARSAT Synthetic Aperture Radar and KOMPSAT EOC: Field Experiments (RADARSAT SAR와 KOMPSAT EOC에 의한 선박 탐지의 검증: 현장 실험)

  • Yang Chan-Su;Kim Sun-Young
    • Proceedings of KOSOMES biannual meeting
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    • 2004.11a
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    • pp.43-47
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    • 2004
  • Two different sensors (here, KOMPSAT and RADARSAT) are considered for ship detection, and are used to delineate the detection performance for their data The experiments are set for coastal regions of Mokpo Port and Ulsan Port and field experiments on board pilot boat are conducted to collect in situ ship validation information such as ship type and length This paper introduce mainly the experiment result of ship detection by both RADARSAT SAR imagery and land-based RADAR data, operated by the local Authority of South Korean, so called vessel traffic system (VTS) radar. Fine imagery of Ulsan Port was acquired on June 19, 2004 and in-situ data such as wind speed and direction, taking pictures of ships and natural features were obtained aboard a pilot ship. North winds, with a maximum speed of 3.1 m/s were recorded Ship's position, size and shape and natural features of breakwaters, oil pipeline and alongside ship were compared using SAR and VTS. It is shown that KOMPSAT/EOC has a good performance in the detection of a moving ship at a speed of kts or more an hour that ship and its wake can be imaged. The detection capability of RADARSAT doesn't matter how fast ship is running and depends on a ship itself, e.g. its material, length and type. Our results indicate that SAR can be applicable to automated ship detection for a VTS and SAR combination service.

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A Pilot Scale Biostimulation Study for In-situ Remediation of Organic Pollutants and PAHs contained in Coastal Sediment (연안 해역퇴적물에 함유된 유기오염물과 PAHs의 현장정화를 위한 파일럿 규모의 생물활성촉진연구)

  • Bae, Byung-Uk;Woo, Jung-Hui;Subha, Bakthavachallam;Song, Young-Chae
    • Journal of Navigation and Port Research
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    • v.40 no.6
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    • pp.441-450
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    • 2016
  • A pilot scale biostimulation experiment was performed under field conditions to degrade organic pollutants and PAHs (Polycyclic Aromatic Compounds) in contaminated coastal sediment. During the experiment, the seawater temperature around the sediment varied from $16.5^{\circ}C$ to $21^{\circ}C$, while the sediment pH was stable at 8.4-8.5. The experiment was conducted over a one year period with a control group and a sample group with a applied biostimulant composed of acetate, sulfate, and nitrate. Chemical oxygen demand decreased 39% in the control group and 79% in the sample group. Volatile solids were reduced from 15 to 7 g/kg in the control group and 2.5 g/kg in the sample group. Out of the 2-, 3- ,4- ,5-, and 6-rings of the 16 vital PAHs, the compound including naphthalene (2-ring), took 2 months to degrade completely, while the degradation efficiency was 55.6% in the control group during the same period. In the case of the 3-ring and 4-ring PAHs, complete degradation in the sample and 46% - 100% degradation in control was observed after one year of the experiment. The 5-ring and 6-ring PAHs were degraded to about 77%-100% in the sample group and 26%-87% in the control group during the one year of the experiment. The study results show that biostimulation is a very effective method to improve the degradation rate of organic pollutants and PAHs (Polycyclic Aromatic Compounds) in contaminated coastal sediment.

Evaluation of Flotation Efficiency and Particle Separation Characteristics of Carbon Dioxide Bubbles using Collision Efficiency Model (단일포집자충돌(SCC) 모델을 이용한 이산화탄소기포의 입자분리특성과 부상효율 평가)

  • Lee, Jun-Young;Kim, Seong-Jin;Yoo, Young-Hoon;Chung, Paul-Gene;Kwon, Young-Ho;Park, Yang-Kyun;Kwak, Dong-Heui
    • Journal of Korean Society on Water Environment
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    • v.28 no.1
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    • pp.129-136
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    • 2012
  • In this century, scientists realized that carbon dioxide gas in the atmosphere cause a greenhouse effect which affects the planet's temperature. Therefore lots of attempts have carried out to decrease the discharge of carbon dioxide gas in the field. The dissolved carbon dioxide flotation (DCF) process was developed as an alternative of DAF process to decrease the discharge and reuse of carbon dioxide as well as to save energy consumption. To investigate the particle separation characteristics and the flotation efficiency of carbon dioxide, SCC model was employed in the DCF process which has been applied extensively for the evaluation and simulation in the DAF process. The simulation results by the SCC model revealed the predicted curve of flotation efficiency became decreased gradually over the optimal pressure range of saturator about 1.6 atm in accordance with the experiment results of the DCF pilot plant and the size distribution and the bubble volume concentration of $CO_{2}$ bubbles depending on the operation pressure of saturator. The findings through the simulation results led to the conclusion that there was no significant difference between $CO_{2}$ bubbles and air bubbles, affecting on the practical flotation efficiency, in terms of the initial collision and attachment efficiency.

Paddy Rice Culture Experiment Using Treated Sewage Effluent From Constructed Wetland (인공습지 오수처리수를 이용한 벼재배 실험)

  • 윤춘경;함종화;우선호;김민희
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.43 no.2
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    • pp.94-104
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    • 2001
  • A pilot study was performed at the experimental field of Konkuk University in Seoul, to examine the feasibility of the constructed wetland system for sewage and the effect of treated sewage irrigation on the paddy rice culture and its soil characteristics. The constructed wetland performed well, in that effluent concentrations of pollutants were significantly lower than concentrations of the influent. Median removal efficiencies of BOD$_{5}$ was about 78% and slightly lower during winter. Removal efficiencies form TN and TP were approximately 48 and 21%, respectively, and relatively less effective than that of BOD$_{5}$. Irrigation of treated sewage to paddy rice culture did not affect adversely in both growth and yield of rice. Instead, plots of treated sewage irrigation showed up to 50% more yield in average than the control plot. It implies that treated sewage irrigation might be beneficial to rice culture rather than detrimental as long as it is treated adequately and used properly. Soil was sampled and analyzed before transplanting and after harvesting. pH was slightly increased due to irrigation water, but it may not be concerned as long as the treated sewage is within the normal range. EC was increased in first year but decreased in second year, therefore salts accumulation in the soil could be less concerned. OM and CES was slightly increased, which might be beneficial on growing plants. TN did not show apparent pattern. Available phosphorus was decreased after rice culture, but the quantity of phosphorus(TP-available phosphorus) was rather increased which implies that excessive phosphorus supply may result in phosphorus accumulation in the soil. Overall, the constructed wetland was thought to be an effective sewage treatment alternative, and treated sewage could be reused as a supplemental source of irrigation water for paddy rice culture without causing adverse effect as long as it is treated adequately and used properly. For full-scale application, further investigation should be followed on environmental risk assessment, tolerable water quality, and fraction of supplemental irrigation.ion.

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Properties of Hand-made Clay Balls used as a Novel Filter Media

  • Rajapakse, J.P.;Madabhushi, G.;Fenner, R.;Gallage, C.
    • Geomechanics and Engineering
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    • v.4 no.4
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    • pp.281-294
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    • 2012
  • Filtration using granular media such as quarried sand, anthracite and granular activated carbon is a well-known technique used in both water and wastewater treatment. A relatively new pre-filtration method called pebble matrix filtration (PMF) technology has been proved effective in treating high turbidity water during heavy rain periods that occur in many parts of the world. Sand and pebbles are the principal filter media used in PMF laboratory and pilot field trials conducted in the UK, Papua New Guinea and Serbia. However during first full-scale trials at a water treatment plant in Sri Lanka in 2008, problems were encountered in sourcing the required uniform size and shape of pebbles due to cost, scarcity and Government regulations on pebble dredging. As an alternative to pebbles, hand-made clay pebbles (balls) were fired in a kiln and their performance evaluated for the sustainability of the PMF system. These clay balls within a filter bed are subjected to stresses due to self-weight and overburden, therefore, it is important that clay balls should be able to withstand these stresses in water saturated conditions. In this paper, experimentally determined physical properties including compression failure load (Uniaxial Compressive Strength) and tensile strength at failure (theoretical) of hand-made clay balls are described. Hand-made clay balls fired between the kiln temperatures of $875^{\circ}C$ to $960^{\circ}C$ gave failure loads of between 3.0 kN and 7.1 kN. In another test when clay balls were fired to $1250^{\circ}C$ the failure load was 35.0 kN compared to natural Scottish cobbles with an average failure load of 29.5 kN. The uniaxial compressive strength of clay balls obtained by experiment has been presented in terms of the tensile yield stress of clay balls. Based on the effective stress principle in soil mechanics, a method for the estimation of maximum theoretical load on clay balls used as filter media is proposed and compared with experimental failure loads.

Pilot Test of Improving Super Retarding Concrete to Control of Hydration Heat Crack of Foundation Mat Mass Concrete (기초매트 매스 콘크리트의 수화열 균열제어로서 초지연 콘크리트 활용에 관한 예비실험)

  • Noh, Sang-Kyun;Baek, Dae-Hyun;Lee, Jae-Sam;Kim, Hyun-Seob;Lee, Byeong-Hoon;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2008.11a
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    • pp.37-41
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    • 2008
  • According to the recent rapidly increasing that construction works are gradually Manhattanized mainly the grand scaled residential buildings, the foundation of the building that is related to safety is increasing for building as a grand scaled mat concrete. Because mat concrete can not be simultaneously placing of concrete in a great quantity due to the circumstance at the field, the inequal deformation of the tensile stress that according to the time lag of hydration heat between the upper layer and the lower layer is affecting as a cause that is the possibility of crack occurrence by increasing. Accordingly, this research checked the efficiency of super retard concrete in applying real structures, and we implemented the preparatory experiment to settle up the inequal deformation of the tensile stress substantially that is according to the time lag of placement between the upper layer and the lower layer by controlling the setting time using the super retarding agent. As the result of test, the more target of delay time lengthened, the more fluidity increased and air content indicated a little differences. There was from 2 to 10 hours between the standard curing and the outside curing at the setting time and in case of calculating the rate of mixing at real structure is required that mix promotion, increasing the amount of mixing, by setting up the curing temperature. The super retard concrete showed the result that in compressive strength, early-age strength was smaller than normal concrete whereas it was same or more figures from at the aging 28days because of the super retarding agent.

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Fundamental Experiment for the Development of Water Pipeline Locator (상수도관로 위치탐사 장비개발을 위한 기초실험)

  • Park, Sang-Bong;Kim, Jin-Won;Oh, Kyeong-Seok;Kim, Min-Cheol;Koo, Ja-yong
    • Journal of Korean Society of Water and Wastewater
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    • v.30 no.3
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    • pp.253-261
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    • 2016
  • A variety of methods for detecting the location of an underground water pipeline are being used across the world; the current main methods used in South Korea, however, have the problems of low precision and efficiency and the limitations in actual application. On this, this study developed locator capable of detecting the location of a water pipe by the use of an IMU sensor, and technology for using the extended karman filter to correct error in location detection and to plot the location on the coordinate system. This study carried out a tract test and a road test as basic experiments to measure the performance of the developed technology and equipment. As a result of the straight line, circular and ellipse track tests, the 1750 IMU sensor showed the average error of 0.08-0.11%; and thus it was found that the developed locator can detect a location precisely. As a result of the 859.6-m road test, it was found that the error was 0.31 m in case the moving rate of the sensor was 0.3-0.6 m/s; and thus it was judged that the equipment developed by this study can be applied to long-distance water pipes of over 1 km sufficiently. It is planned to evaluate its field applicability in the future through an actual pipe network pilot test, and it is expected that locator capable of detecting the location of a water pipe more precisely will be developed through research for the enhancement of accuracy in the algorithm of location detection.

The studies on the preference for attachment to the habitat marine environment and habitat space of Sulculus diversicolor supertexta in Jeju Island (제주도 오분자기의 서식 해양 환경과 서식공간에 대한 부착 선호도에 관한 연구)

  • HEO, Nam-hee;KIM, Keun-hyoung;KANG, Kyoung-Bum;KIM, Suk-jong
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.58 no.2
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    • pp.106-112
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    • 2022
  • As a series of basic research to draw the pilot design measures for developing the habitat apparatus of Sulculus diversicolor supertexta inhabiting the coastal area of Jeju island, this study conducted a water tank experiment to understand the habitat marine environment of Sulculus diversicolor supertexta and the preference of habitat space focusing on the research fisheries performing the discharge of marine products. In the composition degree of marine algae in both fisheries, Donggwi-ri showed the highest gulfweed (79.3%) as brown algae and there were some coralline algae (17.2%) as red algae. Hansu-ri yielded the highest gulfweed (48.1%) as brown algae, which was followed by sea lettuce (10.4%) as green algae. In the preference of habitat space, the shelter angles 40° showed the highest adhesion as number of 82.9, which was followed by 60° and 70° as 69.2 and 68.2 respectively (P<0.05) by reviewing the environmental characteristics of habit of Salculus diversicolor supertexta in the coastal fishery of Jeju Island, when considering the adhesion rate in each of five shelters with different angles. In the future, there should be continuous research and monitoring for designing the fish shelters suitable for the coastal fisheries of Jeju island, and it would be also necessary to add the field-centered sustainable concrete research.

A Study on Teaching-Learning and Evaluation Methods of Environmental Studies in the Middle School (중학교 "환경" 교과의 교수.학습 및 평가 방법 연구)

  • 남상준
    • Hwankyungkyoyuk
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    • v.7 no.1
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    • pp.1-17
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    • 1994
  • This study was performed to determine appropriate teaching-learning and evaluation methods for Environmental Studies. To promote the relevance of our study to the needs of the schools and concerned educational communities of environmental education, we reviewed related literature, conducted questionnaire surveys, interviewed related teachers and administrator, held meetings with experts, and field-tested our findings. For selecting and developing teaching-learning methods of Environmental Studies, findings of educational research in general are considered. moreover, principles of environmental education, general aim of environmental education, orientations of environmental education, and developmental stages of middle school students in educational psychology were attended. In addition, relevance to the purpose of the Environmental Studies curriculum, appropriateness for value inquiry as well as knowledge inquiry, small group centered class organization, social interaction centered teaching-learning process, regional environmental situation, significance of personal environment, evaluation methods of Environmental Studies, multi- and inter-disciplinary contents of the Environmental Studies textbook, suitability to the evaluation methods of Environmental Studies, and emphasis on the social interaction in teaching-learning process were regarded. It was learned the Environmental Studies can be taught most effectively in via of holding discussion sessions, conducting actual investigation, doing experiment-practice, doing games and plate, role-playing and carrying out simulation activities, and doing inquiry. These teaching-learning methods were field-tested and proved appropriate methods for the subject. For selecting and developing evaluation method of Environmental Studies, such principles and characteristics of Environmental Studies as objective domains stated in the Environmental Studies curriculum, diversity of teaching-learning organization, were appreciated. We categorized nine evaluation methods: the teacher may conduct questionnaire surveys, testings, interviews, non-participatory observations; they may evaluate student's experiment-practice performances, reports preparation ability, ability to establish a research project, the teacher may ask the students to conduct a self-evaluation, or reciprocal evaluation. To maximize the effect of these methods, we further developed an application system. It considered three variables, that is, evaluates, evaluation objectives domains, and evaluation agent, and showed how to choose the most appropriate methods and, when necessary, how to combine uses of different methods depending on these variables. A sample evaluation instrument made on the basis of this application system was developed and tested in the classes. The system proved effective. Pilot applications of the teaching-learning methods and evaluation method were made simultaneously; and the results and their implications are as follows. Discussion program was applied in a lesson dealing with the problems of waste disposal, in which students showed active participation and creative thinking. The evaluation method used in this lesson was a multiple-choice written test for knowledge and skills. It was shown that this evaluation method and device are effective in helping students' revision of the lesson and in stimulating their creative interpretations and responces. Pupils showed great interests in the actual investigation program, and this programme was proved to be effective in enhancing students' participation. However, it was also turned out that there must be pre-arranged plans for the objects, contents and procedures of survey if this program is to effective. In this lesson, non-participatory observation methods were used with a focus on the attitudes of students. A scaled reported in general description rather than in grade. Experiment-practice programme was adopted in a lesson for purifying contaminated water and in this lesson, instruction objectives were properly established, the teaching-learning process was clearly specified and students were highly motivated. On the other hand, however, it was difficult to control the class when some groups of students require more times to complete their experiment, and sometimes different results. As regards to evaluation, performance observation test were used for assessing skills and attitudes. If teachers use well-prepared Likert scale, evaluation of all groups within a reasonablely short period of time will be possible. The most effective and successful programme in therms of students' participation and enjoyment, was the 'ah-nah-bah-dah-market' program, which is kind of game of the flea market. For better organized program of this kind, however, are essential, In this program, students appraise their own attitudes and behavior by responding to a written questionnaire. In addition, students were asked to record any anecdotes relating to self-appraisal of changes on one's own attitudes and behaviours. Even after the lesson, students keep recording those changes on letters to herself. Role-playing and simulation game programme was applied to a case of 'NIMBY', in which students should decide where to located a refuse dumping ground. For this kind of programme to e successful, concepts and words used in the script should be appropriate for students' intellectual levels, and students should by adequately introduced into the objective and the procedures of the lessons. Written questionnaire was used to assess individual students' attitudes after the lesson, but in order to acquire information on the changes of students' attitudes and skills, pre-test may have to be made. Doing inquiry programme, in which advantages in which students actually investigated the environmental influence of the areas where school os located, had advantages in developing students' ability to study the environmental problems and to present the results of their studies. For this programme to be more efficient, areas of investigation should be clearly divided and alloted to each group so that repetition or overlap in areas of study and presentation be avoided, and complementary wok between groups bee enhanced. In this programme, teacher assessed students' knowledge and attitudes on the basis of reports prepared by each group. However, there were found some difficults in assessing students' attitudes and behaviours solely on the grounds of written report. Perhaps, using a scaled checklist assessing students' attitudes while their presentation could help to relieve the difficulties.

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Ehtiopiam Agricultural Extension System -The Past Experience, Present Status and Future Direction- (에티오피아 농촌지도사업의 현재와 미래)

  • Besha, Dagnachew Bekele;Park, Duk-Byeong
    • Journal of Agricultural Extension & Community Development
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    • v.21 no.1
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    • pp.219-244
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    • 2014
  • Agricultural extension service in Ethiopia was started in early 1950s with mandate of transferring local research outputs and technologies to farmers, and importing technologies and improved practices from abroad. Extension service provided in this early time was limited to areas surrounding the experiment stations. Since then, Ethiopian Agricultural extension service has passed through at least five stages: the land grant extension system, the Comprehensive Package Programs, the Minimum Package Projects, the Peasant Agricultural Development Program, and the Participatory Demonstration and Training Extension System (PADETS). The comprehensive package extension program was initially implemented in selected pilot areas and eventually to be scaled up to cover about 90% of the farming community within 15-20 years time. The program used demonstration plots managed by development agents and used to train farmers organized through various field days. However, since all of these programs were operational in only small areas, the vast majority of the country was out of their reach. Through Participatory Demonstration and Training Extension System, the extension service in Ethiopia has come under the spotlight and government debates and external reviews are putting additional scrutiny on the system. Despite this long history, the system is still in its infancy in terms of coverage, communication and institutional pluralism. Currently in Ethiopia the Agricultural extension is provided primarily by the public sector, operating in a decentralized manner through which extension is implemented at the district level. Therefore, the main focus of this paper is to scrutinize the past, the present and the future Agricultural extension system in Ethiopia.