• Title/Summary/Keyword: Combined point

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Control of the Sediment in a Combined Sewer Using a Separation Wall

  • Lim, Bong Su;Kwon, Chung Jin;Kim, Do Young;Lee, Kuang Chun
    • Environmental Engineering Research
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    • v.18 no.2
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    • pp.71-75
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    • 2013
  • This study is to evaluate the effects of the separation wall on the sediment quality and quantity in a combined sewer, by surveying the sewer overflow and sediments during a rainfall. Since the separation wall installed in the combined sewer separates the rainfall and the sewage, the flow rate of the sewage is increased, and the amount of the sediment deposited on the sewer is decreased. One sampling point was the outfall of Daesacheon with a separation wall, and the other was the outfall of Gwaryecheon without a separation wall, in Daejeon metropolitan city. The maximum control of the biochemical oxygen demand (BOD) overflow load was more than 38% in the Daesacheon point with the separation wall, during a rainfall of 0.11 mm/hr. The maximum control of the BOD overflow load was 24% in Gwaryecheon without a separation wall, during a rainfall of 1.0 mm/hr. According to the survey results of the sediment in the sewer, the discharged sediment deposited on the sewer in Gwaryecheon point was about 23% to 28% of the total suspended solid during the rainfall. In addition, the average velocity of sewage in the presence of sediment was about 0.30 m/s, and if the separation wall is installed, it was expected to be about 1.01 m/s, that is 3.4 times more than the same conditions, resulting in the reduction of the sediment deposit.

The Capability Comparison of Positioning Performances using GPS and GPS/GLONASS (GPS와 GPS/GLONASS의 측위수행 능력 비교)

  • Park, Woon-Yong;Lee, In-Su;Kim, Jin-Soo
    • Journal of Korean Society for Geospatial Information Science
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    • v.9 no.1 s.17
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    • pp.59-66
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    • 2001
  • Satellite visibility, Accuracy, and Availability were increased by the combined GPS/GLONASS. But, there are some problems such as differences in the time frame, differences in the coordinate datum, and the problem of solving carrier phase ambiguities in the combined carrier frequency solutions due to different GLONASS frequency. Therefore, the accuracy of single point positioning using the combined GPS/GLONASS will be assessed, and intend to study the characteristics of the combined GPS/GLONASS with considered the rate of data acquisition according to the visibility of satellite and elevation cutoff at the combined GPS/GLONASS.

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Performance Analysis of a Gas Turbine for Integrated Gasification Combined Cycle (석탄가스화 복합화력 발전용 가스터빈 성능해석)

  • Lee, J.J.;Cha, K.S.;Sohn, J.L.;Kim, T.S.
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.771-774
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    • 2007
  • Integrated Gasification Combined Cycle (IGCC) power plant converts coal to syngas, which is mainly composed with hydrogen and carbon monoxide, by the gasification process and produces electric power by the gas and steam turbine combined cycle power plant. The purpose of this study is to investigate the influence of the syngas to the performance of a gas turbine in a combined cycle power plant. For this purpose, a commercial gas turbine is selected and its performance characteristics are analyzed with syngas. It is found that different heating values of those fuels and chemical compositions in their combustion gases are the causes in the different performance characteristics. Also, Changing of turbine inlet Mass flow lead to change the turbine matching point, in the event the pressure ratio is changed.

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The effect of Combined Sewer Overflows on river's water quality

  • Bae, Hun Kyun
    • Membrane and Water Treatment
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    • v.11 no.1
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    • pp.49-57
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    • 2020
  • The effect of Combined Sewer Overflow on the river system was investigated throughout three preliminary field tests and three main ones. As a result of the study, Combined Sewer Overflow did not affect water qualities on the main stream since the concentration of the main stream did not significantly changed during rainfall events although the water quality of tributaries has rapidly deteriorated due to the influence of the Combined Sewer Overflow during rainfall events. The main cause of the result is that the flow rate of the tributaries is considerably lower than that of the main stream, so that the tributaries with deteriorated water quality during rainfall events did not significantly affect the quality of the actual main stream. Therefore, the water quality of the Kumho River is more affected by the wastewater treatment facilities that discharges water continuously to the main stream than pollutants from non-point pollution sources during rainfall events. As a result, managements for discharges from wastewater treatment facilities should be strengthened in order to improve the water quality of the river.

Combined Economic and Emission Dispatch with Valve-point loading of Thermal Generators using Modified NSGA-II

  • Rajkumar, M.;Mahadevan, K.;Kannan, S.;Baskar, S.
    • Journal of Electrical Engineering and Technology
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    • v.8 no.3
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    • pp.490-498
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    • 2013
  • This paper discusses the application of evolutionary multi-objective optimization algorithms namely Non-dominated Sorting Genetic Algorithm-II (NSGA-II) and Modified NSGA-II (MNSGA-II) for solving the Combined Economic Emission Dispatch (CEED) problem with valve-point loading. The valve-point loading introduce ripples in the input-output characteristics of generating units and make the CEED problem as a non-smooth optimization problem. IEEE 57-bus and IEEE 118-bus systems are taken to validate its effectiveness of NSGA-II and MNSGA-II. To compare the Pareto-front obtained using NSGA-II and MNSGA-II, reference Pareto-front is generated using multiple runs of Real Coded Genetic Algorithm (RCGA) with weighted sum of objectives. Furthermore, three different performance metrics such as convergence, diversity and Inverted Generational Distance (IGD) are calculated for evaluating the closeness of obtained Pareto-fronts. Numerical results reveal that MNSGA-II algorithm performs better than NSGA-II algorithm to solve the CEED problem effectively.

NSGA-II Technique for Multi-objective Generation Dispatch of Thermal Generators with Nonsmooth Fuel Cost Functions

  • Rajkumar, M.;Mahadevan, K.;Kannan, S.;Baskar, S.
    • Journal of Electrical Engineering and Technology
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    • v.9 no.2
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    • pp.423-432
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    • 2014
  • Non-dominated Sorting Genetic Algorithm-II (NSGA-II) is applied for solving Combined Economic Emission Dispatch (CEED) problem with valve-point loading of thermal generators. This CEED problem with valve-point loading is a nonlinear, constrained multi-objective optimization problem, with power balance and generator capacity constraints. The valve-point loading introduce ripples in the input-output characteristics of generating units and make the CEED problem as a nonsmooth optimization problem. To validate its effectiveness of NSGA-II, two benchmark test systems, IEEE 30-bus and IEEE 118-bus systems are considered. To compare the Pareto-front obtained using NSGA-II, reference Pareto-front is generated using multiple runs of Real Coded Genetic Algorithm (RCGA) with weighted sum of objectives. Comparison with other optimization techniques showed the superiority of the NSGA-II approach and confirmed its potential for solving the CEED problem. Numerical results show that NSGA-II algorithm can provide Pareto-front in a single run with good diversity and convergence. An approach based on Technique for Ordering Preferences by Similarity to Ideal Solution (TOPSIS) is applied on non-dominated solutions obtained to determine Best Compromise Solution (BCS).

Estimation of Interevent Time for Management of Non-Point Source Pollutants (비점오염원 관리를 위한 독립호우 결정)

  • Lee, Eui Hoon;Yoo, Do Geun;Kim, Joong Hoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.5
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    • pp.3159-3168
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    • 2014
  • Interevent Time Definition(IETD) is essential in CSOs(Combined Sewer Overflows) tank design for the treatment of non-point source pollution. However, existent rainfall analysis can not calculate total amout of non-point source pollution. For deviding continuous rainfall events, therre are several IETD calculating methods. In this research, After calculate IETD by existents methods, problem of results is identified as existents method. To supplement these problems, new method using exponential decay function is suggested. The confidence range of ${\lambda}$ is estimated.

Prevelance of Common YMDD Motif Mutations in Long Term Treated Chronic HBV Infections in a Turkish Population

  • Alagozlu, Hakan;Ozdemir, Ozturk;Koksal, Binnur;Yilmaz, Abdulkerim;Coskun, Mahmut
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.9
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    • pp.5489-5494
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    • 2013
  • In the current study we aimed to show the common YMDD motif mutations in viral polymerase gene in chronic hepatitis B patients during lamivudine and adefovir therapy. Forty-one serum samples obtained from chronic hepatitis B patients (24 male, 17 female; age range: 34-68 years) were included in the study. HBV-DNA was extracted from the peripheral blood of the patients using an extraction kit (Invisorb, Instant Spin DNA/RNA Virus Mini Kit, Germany). A line probe assay and direct sequencing analyses (INNO-LIPA HBV DR v2; INNOGENETICS N.V, Ghent, Belgium) were applied to determine target mutations of the viral polymerase gene in positive HBV-DNA samples. A total of 41 mutations located in 21 different codons were detected in the current results. In 17 (41.5%) patients various point mutations were detected leading to lamivudin, adefovir and/or combined drug resistance. Wild polymerase gene profiles were detected in 24 (58.5%) HBV positive patients of the current cohort. Eight of the 17 samples (19.5%) having rtM204V/I/A missense transition and/or transversion point mutations and resistance to lamivudin. Six of the the mutated samples (14.6%) having rtL180M missense transversion mutation and resistance to combined adefovir and lamivudin. Three of the mutated samples (7.5%) having rtG215H by the double base substituation and resistance to adefovir. Three of the mutated samples (7.5%) having codon rtL181W due to the missense transversion point mutations and showed resistance to combined adefovir and lamivudin. Unreported novel point mutations were detected in the different codons of polymerase gene region in the current HBV positive cohort fromTurkish population. The current results provide evidence that rtL180M and rtM204V/I/A mutations of HBV-DNA may be associated with a poor antiviral response and HBV chronicity during conventional therapy in Turkish patients.

The Likelihood for a Two-Dimensional Poisson Exceedance Point Process Model

  • Yun, Seok-Hoon
    • Communications for Statistical Applications and Methods
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    • v.15 no.5
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    • pp.793-798
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    • 2008
  • Extreme value inference deals with fitting the generalized extreme value distribution model and the generalized Pareto distribution model, which are recently combined to give a single model, namely a two-dimensional non-homogeneous Poisson exceedance point process model. In this paper, we extend the two-dimensional non-homogeneous Poisson process model to include non-stationary effect or dependence on covariates and then derive the likelihood for the extended model.

The function of point injection in improving learning and memory dysfunction caused by cerebral ischemia

  • Chen, Hua-De
    • Journal of Pharmacopuncture
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    • v.4 no.1
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    • pp.49-53
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    • 2001
  • This experiment has investigated the influence of Yamen (Du. 15) point injection on learning and memory dysfunction caused by cerebral ischemia and reprofusion in bilateral cervical general artery combined with bleeding on mouse tail to mimic vascular dementia in human beings. By dividing 40 mice into 4 groups (group1false operation group, group2model group, group3point injection with Cerebrolysin group4point injection with saline.) According to random dividing principles, we observed the influence of Yamen(Du. 15) point injection on the time of swimming the whole course used by model mice which had received treatment for different days in different groups, and the influence of those mice on wrong times they entered blind end. The result showed that point injection with Cerebrolysin and saline could improve learning and memory dysfunction of the mice caused by cerebral ischemia.