• Title/Summary/Keyword: data stream technology

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An Analysis of Groudwater Budget in a Water Curtain Cultivation Site (청원 수막재배 지역의 물수지 특성 분석)

  • Chang, Sun Woo;Chung, Il-Moon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.6
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    • pp.1259-1267
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    • 2015
  • In Korea, rural groundwater development faces new challenge, which have not been experienced so far. The problem is a groundwater depletion by the water curtain cultivation (WCC) during winter season. This study investigates the groundwater depletion using three-dimensional finite difference groundwater flow program, MODFLOW to verify the water budget of the shallow aquifer of Cheongweon area. Interdisciplinary research, which has become a worldwide trend, has been adopted in studying groundwater modeling in field scale. In particular, the method of groundwater recharge estimation adopted precise modeling techniques, SWAT to groundwater flow modeling. Based on qualified field data, the model calibrated and validated its reliability. The objective of this study is to simulate various stream-aquifer interactions according to groundwater pumping with artificial boundaries, such as weirs and drainage system. We also analyzed a seasonal variation of cumulative water budget of the site to quantify the groundwater depletion and recovery in the pumping field.

Inventory Development according to Aquatic Environment Fitness and Classification Characteristics of Plants for Urban Water Space (수환경 적응도에 따른 식물 목록 구축 및 도시 수 공간에 적용 가능한 식물 분류특성)

  • Li, Lan;Kwon, Hyo Jin;Kim, Hyeong Guk;Park, Mi Ok;Koo, Bonhak;Choi, Il Ki
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.16 no.2
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    • pp.93-104
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    • 2013
  • The purpose of this study was to develop a list of plants that adapted to the aquatic environment in urban areas based on the list of plants surveyed through literature review and field surveys, and to classify the types of vegetation according to the five categories of plant distributions set by the U.S. Fish and Wildlife Service (1988) in the aspect of the adaptability of plants to the aquatic environment. Results of the classification by category according to the adaptability to the aquatic environment for the plant species surveyed through literature review and field surveys showed that there are 45 species of OBL, 96 species of FACW, 66 species of FAC, and 94 species of FACU, totaling 650 species. In addition, a total of 50 species excluding exotic species, endangered species, and naturally introduced plants are proposed as appropriate plants for the urban aquatic environment that will be artificially constructed. The results of the study can be utilized as the basic information for maintaining diversity and stability of the ecosystem during the restoration of water ecology; they can serve as useful data for the development of an optimum vegetation model when planting in water spaces in the future and preparing proper planting plans for each space. In addition, it is believed that the information will be useful in wetland identification and evaluation by observing plant species that appear only in wetlands.

Estimation of Soil Erosion and Sediment Outflow in the Mountainous River Catchment (산지하천 유역의 토양침식량과 유사유출량 평가)

  • Kim, DongPhil;Kim, JooHun
    • Journal of Wetlands Research
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    • v.16 no.2
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    • pp.221-233
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    • 2014
  • Soil erosion, transportation, and sedimentation by water flow often occur in a stream. This excessive occurrence threatens the safety of hydraulic structures, and aggravates natural disasters like flood. To prevent soil disaster according to the soil erosion, it is necessary to predict accurate sediment outflow primarily. Besides, it is very important to choose appropriate models by basin characteristics, to estimate accurate quantity of related factors, and to acquire available hydrological data. Therefore, the purpose of this study is to estimate soil erosion amount and sediment amount according to rainfall-runoff by using rainfall, discharge, and sediment in the Seolmacheon experimental catchment. And, it proposed sediment delivery ratio of the Seolmacheon catchment by result of studying sediment delivery ratio. Hereafter, this study will estimate sediment delivery ratio by basin characteristics, and formulate the method of estimating soil erosion and sediment outflow in various conditions by applying the results in other catchments.

Analysis of Sediment Discharge by Long-term Runoff in Nakdong River Watershed using SWAT Model (SWAT 모형을 이용한 낙동강 유역의 장기 유출에 따른 유사량 분석)

  • Ji, Un;Kim, Tae-Geun;Lee, Eun-Jeong;Ryoo, Kyong-Sik;Hwang, Man-Ha;Jang, Eun-Kyung
    • Journal of Environmental Science International
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    • v.23 no.4
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    • pp.723-735
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    • 2014
  • Sediment discharge by long-term runoff in the Nakdong River watershed should be predicted for the maintenance and management of the Nakdong River newly changed by the four major river restoration project. The data establishment by the analysis of runoff and sediment discharge using the long-term watershed model is necessary to predict possible problems by incoming sediments and to prepare countermeasures for the maintenance and management. Therefore, sediment discharges by long-term runoff in the main points of the Nakdong River were calculated using SWAT(soil and water assessment tool) model and the relations and features between rainfall, runoff, and sediment discharge were analyzed in this study. As a result of sediment discharge calculation in the main points of the Nakdong River and tributaries, the sediment discharge at the outlet of the Naesung Stream was greater than the Jindong Station in the Lower Nakdong River from 1999 to 2008 except the years with low precipitation. The sediment discharge at the Nakdong River Estuary Barrage (NREB) was corresponding to 20% of the Jindong Station which is located about 80 km upstream from NREB.

Comparative Analysis of Filtering Techniques for Vegetation Points Removal from Photogrammetric Point Clouds at the Stream Levee (하천 제방의 영상 점군에서 식생 점 제거 필터링 기법 비교 분석)

  • Park, Heeseong;Lee, Du Han
    • Ecology and Resilient Infrastructure
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    • v.8 no.4
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    • pp.233-244
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    • 2021
  • This study investigated the application of terrestrial light detection and ranging (LiDAR) to inspect the defects of the vegetated levee. The accuracy of vegetation filtering techniques was compared by applying filtering techniques on photogrammetric point clouds of a vegetated levee generated by terrestrial LiDAR. Representative 10 vegetation filters such as CIVE, ExG, ExGR, ExR, MExG, NGRDI, VEG, VVI, ATIN, and ISL were applied to point cloud data of the Imjin River levee. The accuracy order of the 10 techniques based on the results was ISL, ATIN, ExR, NGRDI, ExGR, ExG, MExG, VVI, VEG, and CIVE. Color filters show certain limitations in the classification of vegetation and ground and classify grass flower image as ground. Morphological filters show a high accuracy of the classification, but they classify rocks as vegetation. Overall, morphological filters are superior to color filters; however, they take 10 times more computation time. For the improvement of the vegetation removal, combined filters of color and morphology should be studied.

A study on Spatiotemporal Variations of distribution characteristics in Artificial Rivers of the Brackish Water Zone (기수역 인공하천에서 시공간적 수질분포 특성 연구)

  • Kim, Yoon-Jeong;Choi, Ok Youn;Han, Ihn-Sup
    • Journal of Korean Society of Water Science and Technology
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    • v.26 no.6
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    • pp.89-97
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    • 2018
  • The purpose of this reaserch is to analyze the charateristics of water quality in space through the operation of ARA River in Artificial Rivers of the Brackish Water Zone. The spatial distribution measured water temperature and salt levels for the surface, middle and deep layers by dividing the four areas of Incheon, Sicheon, Gyeyang and Gimpo. Water temperature did not vary much by water depth and branch, and its purpose is to maintain stable water environment through correlation analysis and operation. To examine the temporal and spatial distribution patterns of the Arachon, we measured DO on the Incheon branch, Sicheon, Gyeyang and Gimpo branch twice a month, and on the surface, the temperature level, The water temperature did not vary much by depth and location, and the water temperature in January and March tended to rise from Incheon to Gimpo, with the average difference of 1.1 degrees during the same period. The salinity difference between Incheon and Gimpo sites was 3.3 psu deep and 5.4 psu deep. In particular, floodgates from July to September are found to be less than 10psu overall, which is considered to be a gas due to the effects of floods and the inflow of Gulpo Stream. D.O. is located in some areas due to summer rains. The hypoxic layer has been identified.Analysis of seasonal data shows that water temperature and DO are strongly correlated in autumn. It was found that the water temperature and salt levels in the fall showed a weak correlation.

Multi-stage Membrane Process for $CO_2$ Separation from Flue Gas Using PES Hollow Fiber Membrane Modules (폴리이서설폰 중공사모듈을 이용한 연소배가스로부터 이산화탄소 분리회수를 위한 다단계 막분리공정 연구)

  • Choi Seung-Hak;Kim Jeong-Hoon;Kim Eeom-Sik;Lee Soo-Bok
    • Membrane Journal
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    • v.15 no.4
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    • pp.310-319
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    • 2005
  • This paper describes the preliminary study on the development of multi-stage membrane demonstration plant for removal of carbon dioxide from flue gas stream being emitted from LNG boiler in thermal power generation plant. The prerequisite requirement is to design and develop the membrane process producing a $99\%\;CO_2$ with $90\%$ recovery from LNG flue gas of 1,000 $Nm^3$/day. Asymmetric polyethersulfone hollow fiber membranes and membrane modules developed in this laboratory[1] were used in this study. Using the permeation data for the hollow fiber membranes, modelling on the membrane module and multi-stage membrane process was done to meet the requirement condition of the process design. The effects of the operating pressure of feed and permeate side and feed concentration on $CO_2$ purity and recovery were investigated experimentally with the developed hollow fiber modules. These experimental results matched well with theoretical modelling results.

On a High-Speed Implementation of LILI-128 Stream Cipher Using FPGA/VHDL (FPGA/VHDL을 이용한 LILI-128 암호의 고속화 구현에 관한 연구)

  • 이훈재;문상재
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.11 no.3
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    • pp.23-32
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    • 2001
  • Since the LILI-128 cipher is a clock-controlled keystream generator, the speed of the keystream data is degraded in a clock-synchronized hardware logic design. Basically, the clock-controlled $LFSR_d$ in the LILI-128 cipher requires a system clock that is 1 ~4 times higher. Therefore, if the same clock is selected, the system throughput of the data rate will be lowered. Accordingly, this paper proposes a 4-bit parallel $LFSR_d$, where each register bit includes four variable data routines for feed feedback of shifting within the $LFSR_d$ . Furthermore, the timing of the propose design is simulated using a $Max^+$plus II from the ALTERA Co., the logic circuit is implemented for an FPGA device (EPF10K20RC240-3), and the throughput stability is analyzed up to a late of 50 Mbps with a 50MHz system clock. (That is higher than the 73 late at 45 Mbps, plus the maximum delay routine in the proposed design was below 20ns.) Finally, we translate/simulate our FPGA/VHDL design to the Lucent ASIC device( LV160C, 0.13 $\mu\textrm{m}$ CMOS & 1.5v technology), and it could achieve a throughput of about 500 Mbps with a 0.13$\mu\textrm{m}$ semiconductor for the maximum path delay below 1.8ns.

The Trend of Cigarette Design and Tobacco Flavor System Development

  • Wu, Jimmy Z.
    • Journal of the Korean Society of Tobacco Science
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    • v.24 no.1
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    • pp.67-73
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    • 2002
  • In light of addressing consumer health concern, coping with anti-tobacco movement, and promoting new product, tobacco industry is actively pursuing to make a new generation of cigarettes with low tar and nicotine deliveries, and less harmful substances. Low tar and low nicotine cigarettes increases their market shares dramatically world wide, especially in KT&G, multinational tobacco companies, EU countries, even in China regulated by CNTC to set up yearly target to lower tar and nicotine deliveries. On the other hand, to design a new cigarette with reduced harmful substances begins to gain speed. The "modified Hoffmann list" publishes thirty plus substances in tobacco leaf and main smoke stream, which is the prime suspect causing health problems. Various ways and means are developed to reduce such components including new tobacco breeds, new curing method, tobacco leaf treatment before processing, selected filtration system, innovated casing system to reduce free radicals, as well as some non conventional cigarette products. In TSRC held this year, the main topic is related to reduce tobacco specific nitrosamines in tobacco leaf. The new generation of cigarette is in the horizon. It still needs a lot help to produce commercial products with satisfied taste and aroma characters. The flavor industry is not regulated by many governments demanding which ingredients might or might not be for tobacco use. However, most of the cigarette companies self impose a list of ingredients to guide flavor suppliers to design flavors. Unfortunately, the number of ingredients in those lists is getting shorter every year. It is understandable that the health is not the only reason. Some cigarette companies are playing safe to protect the company from potential lawsuit, while others are just copying from their competitors. Moreover, it is obvious that it needs more assistance from casings and flavors to design new generation of cigarettes with missing certain flavor components in tobacco leaf and main smoke stream. These flavor components are either non-existed or at lower level at new form of cured tobacco leaf or filtered in the main smoke stream along with reduced harmful substances. The use of carbon filters and other selected filtration system poses another tough task for flavor system design. Specific flavor components are missing from the smoke analysis data, which brings a notion of "carbon taste" and "dryness" of mouth feel. It is ever more demanded by cigarette industry to flavor suppliers to produce flavors as body enhancer, tobacco notes, salivating agents, harshness reducer, and various of aromatic notes provided they are safe to use. Another trend is that water based flavor or flavor with reduced ethanol as solvent is gaining popularity. It is preferred by some cigarette companies that the flavor is compounded with all natural ingredients or all ingredients should he GMO free. The new generation of cigarettes demands many ways of new thinking process. It is also vital for tobacco industry. It reflects the real needs for the consumers that the cigarette product should be safe to use as well as bearing the taste and aroma characters smokers always enjoyed. An effective tobacco flavor system is definitely a part of the equation. The global trend of tobacco industry is like trends of any other industries lead by consumer needs, benefited with new technology availability, affected by the global economy, and subjected for various rules and regulations. Anti-tobacco organizations and media exceptionally scrutinize cigarette, as a legal commercial product. Cigarette is probably the most studied commercial product for its composition, structure, deliveries, effects, as well as its new developmental trend. Therefore, any new trend of cigarette development would be within these boundaries. This paper is trying to point out what it would be like for tobacco industry in the next few yews and what concerns the tobacco industry. It focuses mostly on the efforts to produce safer cigarettes. It is such a vital task for the tobacco industry and its affiliate industries such as cigarette papers, filters, flavors, and other materials. The facts and knowledge presented in this paper might be well known for the public. Some of the comments and predictions are very much personal opinion for a further discussion.

The Mediating Effects of the Manufacturing Capability and the Testing and Inspection Capability on the Relation between Small and Medium Venture Firms' External Information Network Heterogeneity and Technology Commercialization Capability (제조 역량과 시험 및 검사 역량이 중소벤처기업의 외부 정보 네트워크의 다양성과 기술 사업화 역량 사이의 관계에 미치는 매개 효과)

  • Hau, Yong Sauk
    • Journal of Digital Convergence
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    • v.15 no.10
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    • pp.233-241
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    • 2017
  • This study has attempted to empirically analyze the mediating effects of small and medium venture firms' manufacturing capability and testing and inspection capability on the relation between their external information network heterogeneity and technology commercialization capability with a view to diversifying the research stream on the influential factors to small and medium firms' technology commercialization capability. By performing the ordinary least squares regression analysis, the Sobel test, and the Baron and Kenny test based on the 683 data of South Korean small and medium venture firms with the IBM SPSS version 23, this study provides the three empirical findings to be useful for future studies on the roles of small and medium venture firms' the manufacturing capability and testing and inspection capability. First, small and medium venture firms' manufacturing capability partially mediates the positive effect of their external information network heterogeneity on their technology commercialization capability. Second, their testing and inspection capability partially mediates this positive effect. Third, their manufacturing capability and testing and inspection capability jointly and partially mediates this positive effect.