• Title/Summary/Keyword: Flow Control System

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Development of a technology valuation method for buyers in technology transfer (기술이전을 위한 기술수요자 중심의 가치평가 방법론 개발)

  • Yun, DooSeob;Park, Inchae;Yoon, Byungun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.11
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    • pp.155-167
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    • 2016
  • Technology valuation is necessary for determining the feasibility of technology commercialization. However, existing methods focus only on technology evaluation, with limitation in sufficiently reflecting buyer viewpoint. In addition, it causes a gap between estimated value and market value. Therefore, this research suggests a new technology valuation method which focuses on the perspectives of buyers. Technology factors, buyer factors and market factors are first determined and their relationships are analyzed. Second, based on the relationships, profit projections are calculated using the discount cash flow method. Finally, profit projections for each year are discounted. The proposed method was applied using the ubiquitous home network system and audio service and illumination control method and results compared with the value of a technology valuation guide distributed by the Ministry of Trade, Industry and Energy. The technology valuation approach used in this research is quantitative and systematic and can be used as a decision making support tool in technology transfer, reflecting various perspectives of stakeholders.

Capacity of Urban Freeway Work Zones (도시 고속도로 공사구간 용량 산정)

  • Lee, Mi Ri;Kim, Do-Gyeong;Kim, Hyo-Seung;Lee, Chungwon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.3
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    • pp.1123-1130
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    • 2013
  • This paper aims to estimate work zone base capacity by the number of lanes for urban freeway. To do this, data were collected from the field survey and the database system maintained by traffic control center, and analyzed with four different methods such as the average maximum observation flow rate, headway, regression analysis, and parameter inspection. The work zone base capacity for urban freeway is estimated based on the average maximum observation flow rate and headway method, which are more reliable methods compared to others. The average capacity is 1,650pcphpl when the design speed is 80km/h. The capacity of four lanes one-way work zones was about 1,700pcphpl, while one of 2 lanes one-way work zones was about 1,600pcphpl. The capacity reduction rates for each are 0.15 and 0.2, respectively. The smaller the number of lane is, the more base capacity is reduced. For verification of results, we estimate the capacity by simulation analysis using PARAMICS, and compare with analytical results by a statistical method. This research can be used for efficient and systemic management of work zone in the urban freeway.

A Study on the Warpage of Glass Fiber Reinforced Plastics for Part Design and Operation Condition: Part 1. Amorphous Plastics (유리섬유로 보강된 수지에서 제품설계 및 성형조건에 따른 휨의 연구: Part 1. 비결정성 수지)

  • Lee, Min;Kim, Hyeok;Lyu, Min-Young
    • Polymer(Korea)
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    • v.36 no.5
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    • pp.555-563
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    • 2012
  • Warpage of injection molded product is caused by non-uniform shrinkage during shaping operation and relaxation of residual stress. Robust part design and glass fiber reinforced reins have been adopted to prevent warpage of part. Warpages for part designs have been investigated in this study according to the injection molding conditions. Part design contains flat specimen and two different rib designs in the flat part. Resins used in this study were glass fiber reinforced amorphous plastics, PC and ABS. Different rib designs showed significant differences of warpages in the parts. Various warpages have been observed in the three regions of the part, near gate region, opposite region to the gate, and flow direction region. Results of computer simulation revealed that the warpages were strongly related to glass fiber orientation. Flat specimen showed the smallest warpage and the specimen with ribs to the flow direction showed a high resistance to warpage. Warpage highly depended upon part design rather than molding condition. It was concluded that the rib design and selection of gate location in injection molding would be the most important factors for the control of warpage since those are directly related to the fiber orientation during molding.

Stage-Discharge Rating Curve Model Development and Modification (하천 수위-유량곡선식 개선 및 모형개발)

  • Chang, Ki-Hwan;Lee, Jae-Hyoung
    • Journal of Korea Water Resources Association
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    • v.38 no.4 s.153
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    • pp.271-280
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    • 2005
  • The goal of this study is to recommend a new type of stage-discharge rating curve ($Q=p(h-e)^{\beta}-{\gamma}$) useful for satisfying divergence, and one other seemingly irresolvable problem related to exited rating curves, while also extending this rating curve model. The problem of divergence is that during the finding of the CZF (cease-to-zero flow) parameter e and while minimizing the sum of total errors of the estimated curve, the exponential parameter ${\beta}$ become an abnormally large value. The insoluble problem is that when the value e is greater then the recorded minimum at the gauged stage, it is impossible to have a negative logarithm value (h-e). The two problems above can be satisfied by adapting the control value ${\gamma}$, which affects the reduction of ${\gamma}$ and gives us the possibility of controlling (h-e) over zero. The study results show that the effects of parameter ${\gamma}$ are very similar to that of e when conducting physical and sensitivity analyses. This system can be used towards developing a new stage-discharge rating curve for river discharge, for use in evaluating the acceptability of existing stage-discharge rating curves generated by using hydrologic analyses at all stations.

Analysis of Groundwater Use in Kap-cheon Basin (갑천 유역의 지하수 이용 특성 분석)

  • Hong, Sung-Hun;Kim, Jeong-Kon
    • Journal of Korea Water Resources Association
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    • v.41 no.5
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    • pp.463-471
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    • 2008
  • The purpose of this study is to analyze the features of groundwater use to utilize as basic information for water-cycle analysis system development and effective groundwater management in the Kap-cheon basin. The cumulative relationship between groundwater use and the number of wells was analyzed to estimate the representative total groundwater use and the number of wells for the Kap-cheon basin. Then, the spatial distribution of groundwater use in the basin were figured out using the detailed information on groundwater use in each well. Finally, the reasonability of groundwater resources management in Kap-cheon basin was evaluated by comparing groundwater recharge and groundwater use in sub-basins and major stream basins. The results of the analysis showed about 25% of the total wells could represent 90% of groundwater use ($37,923,516\;m^3$/year) in the Kap-cheon basin. A detailed analysis on the groundwater uses in the vicinity of down-town areas of Daejeon metropolitan city showed high groundwater uses ($1.4{\sim}11.1$ times) compared to the groundwater recharge previously estimated using the rainfall-runoff model. The ratio of groundwater use and groundwater recharge for the major river basins in Kap-cheon basin ranged from 1.9 to 2.3 indicating that more sustainable groundwater management should be exercised. The results of this study can be used as basic information in evaluating the change of groundwater flow, stream flow and water-cycle for various groundwater uses in the Kap-cheon basin.

Membrane Fouling Control Effect of Periodic Water-back-flushing in the Tubular Carbon Ceramic Ultrafiltration System for Recycling Paper Wastewater (제지폐수 재활용을 위한 관형 탄소계 세라믹 한외여과장치에서 물 역세척의 막오염 제어 효과)

  • 김미희;박진용
    • Membrane Journal
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    • v.11 no.4
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    • pp.190-203
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    • 2001
  • In this study the discharged wastewater from a paper plant was filtrated by 4 kinds of tubular carbon ceramic ultrafiltration membranes with periodic water-back-flushing. We could investigate effects of watch-back-flushing period, transmembrane pressure (TMP) and flow rate, and find optimal operating conditions. The back-f1ushing time (BT) was fixed at 3 sec, and fi1tration times (FT) werc changed in 15~60 scc, TMP in 1.00~2.50$kg_{f}$/$cm^2$, and the flow rates in 0.27~1.75 L/min. The optimal conditions were discussed in 7he viewpoints of dimensionless permeate flux (J/J$_{0}$), total permeate volume ($V^T$) and resistance of membrane fouling ($R^f$). Optima1 back-flushing period was BT/FT=0.20, suggesting that the frequent back-flushing should decrease membrane fouling. Optimal TMP in the viewpoint of $V^T$ was 1.00~1.55$kg_{f}$/$cm^2$, suggesting that rising TMP should increase membrane fouling and decrease permeate flux. But, rising f1ow rate should decrease membrane fouling and increase permeate flux. Then, average rejection rates of pollutants filtratedby carbon ceramic membranes were 88~98 % for turbidity, 48~72% fort $COD_{cr}$ and 37~76% for TDS.

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Effects of supplemental undaria powder, herb and wasabi in the diets on growth, body composition, blood chemistry and non-specific immune response of juvenile flounder, Paralichthys olivaceus

  • Park, Sang-Un;Kwon, Mun-Gyeong;Lee, Yoon-Ho;Kim, Kyoung-Duck;Shin, Il-Shik;Lee, Sang-Min
    • Proceedings of the Korean Aquaculture Society Conference
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    • 2003.10a
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    • pp.74-75
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    • 2003
  • This study was conducted to investigate the effects of several additives(macroalgae, wasabi, and herb) in formulated diets on the growth, body composition, blood chemistry and non-specific immune response of juvenile flounder. Three replicates of juveniles (average weight 8.4 g) in flow-through aquarium system were fed one of six isonitrogenous (45%) and isolipidic (8%) diets containing 5 and 10% Undaria powder, 2% wasabi leaf, 2% wasabi stem, and 0.5% herb (Obosan) for 8 weeks. Survival was not affected by the different dietary additives (P>0.05). The highest weight gain and feed efficiency offish fed the diet containing 0.5% herb were significantly higher than those of fish fed the diets containing 10% Undaria powder (P<0.05). No significant differences were found in contents of moisture, crude protein, lipid and ash of whole body (P>0.05). Fish fed the diet containing 10% Undaria powder showed the highest moisture and the lowest crude lipid contents in the liver. Although hematological parameters (red blood cell, hematocrit and hemoglobin) and serum constituents (glucose, total cholesterol and glutamic-oxaloacetic transaminase) contents of fish varied between treatments, no specific trend was observed throughout feeding periods. Lysozyme activity in the serum and nitroblue tetrazolium reduction of macrophage in the head kidney from fish fed the diets containing herb was significantly higher than those of fish fed the control diet. The results of this study suggest that herb as an additive in this formulated diet may improve growth and non-specific immune response of juvenile flounder.

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Fluid Structure Interaction Analysis of Membrane Type LNG CCS Experiencing the Sloshing Impact by Impinging Jet Model (멤브레인형 LNG 화물창의 강도평가를 위해 적용된 분사모델을 이용한 유체구조 연성해석에 관한 연구)

  • Hwang, Se Yun;Lee, Jang Hyun
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.1
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    • pp.71-78
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    • 2015
  • The reliable sloshing assessment methods for LNG CCS(cargo containment system) are important to satisfy the structural strength of the systems. Multiphase fluid flow of LNG and Gas Compressibility may have a large effect on excited pressures and structural response. Impinging jet model has been introduced to simulate the impact of the LNG sloshing and analyze structural response of LNG CCS as a practical FSI(fluid structure interaction) method. The practical method based on fluid structure interaction analysis is employed in order to evaluate the structural strength in actual scale for Mark III CCS. The numerical model is based on an Euler model that employs the CVFEM(control volume based finite element method). It includes the particle motion of gas to simulate not only the interphase interaction between LNG liquid and gas and the impact load on the LNG insulation box. The analysis results by proposed method are evaluated and discussed for an effectiveness of FSI analysis method.

An Experimental Study on the Toluene Control Characteristics of Biofilter Packed with Compost, Peatmoss and GAC (Compost, Peatmoss, GAC의 복합 메디아로 충전된 Biofilter의 Toluene 제어특성에 관한 실험적 연구)

  • Eom, Yun-Sung;Han, Se-Hyun;Jung, Yong-Won
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.3
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    • pp.265-276
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    • 2007
  • The primary objective of this study is to investigate the effect of media on the performance of biofilters. Two types of experiments were carried out in this study. The first type of experiment used a biofilter with the media composed of three different packing materials of compost, peatmoss and GAC(granular activated carbon), whereas the second type used a biofilter with the media composed of compost only. It was found from the two experiments that the biofilter composed of compost, peatmoss and GAC showed better performance than the one composed of compost only with the higher toluene removal efficiency, lower pressure drop, and more uniform media moisture content. In particular, no appreciable media compression occurred for the biofilter composed of compost, peatmoss and GAC, whereas significant media compression took place in the biofilter composed of compost only. As suggested by the other researchers, it is likely that GAC may be responsible for the higher toluene removal efficiency in the case of the biofilter composed of mixed media especially for the early stage of biofiltration due to its adsorption capability of toluene of such high concentration as 300 ppm. It was also regarded that GAC may playa major role in maintaining lower media pressure drop in the case of the mixed media than the media with compost only because of its mechanical strength resisting to the compression. Nonetheless, further refined experiments may need to draw more accurate conclusion. The results of the additional test run using the same mixed media showed that the biofilter system using the mixed media can be consistently operated for more than 100 days very stably despite sudden change in operating conditions of temperature and flow rate.

Coupling Simulation with Multi-dimensional Models for River Flow (다차원 모형을 이용한 하천흐름 연계모의)

  • Ahn, Jung Min;Hur, Young Teck;Lyu, Siwan
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.1
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    • pp.137-147
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    • 2013
  • It is essential to understand the hydraulic characteristics of rivers for increasing flood-control capacity and operating hydraulic structures efficiently. Multi-dimensional models can be the proper measures to obtain the detailed information on the hydraulic characteristics of rivers. But huge amount of data and time-consuming work have been the obstacle for applying multi-dimensional models. In this study, simulation technique with multi-dimensional model(EFDC), coupled with COSFIM and FLDWAV, has been developed and applied to the real river system for verification. Developed technique can offers spatial and grid unit information as well as line and section unit information from 1-D modeling. It is considered that the coupling simulation technique can provide useful hydraulic information for river management and treatment.