• Environmental Engineering Research
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• 제18권2호
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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.

• 대한공간정보학회지
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• 제9권1호
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• pp.59-66
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• 2001

GPS/GLONASS 결합을 통해 위성의 가시성, 정확성, 그리고 이용성 등이 증가하였다. 하지만 두 시스템 결합에서 시간계 차이, 좌표계 차이, 그리고 GLONASS의 상이한 주파수에 의해 결합 반송파 주파수에서 반송파 미지정수 결정에 관한 문제점을 가지고 있다. 따라서 본 연구에서는 단독위치결정에서 GPS/GLONASS 결합에 의한 위치결정 정확도를 평가하고, GPS/GLONASS 결합에 의한 위성의 가시성과와 위성신호 수신고도각에 따른 자료획득율을 검토함으로써 GPS/GLONASS 결합 특성을 알아보고자 한다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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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.

• Membrane and Water Treatment
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• 제11권1호
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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.

• Journal of Electrical Engineering and Technology
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• 제8권3호
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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.

• Journal of Electrical Engineering and Technology
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• 제9권2호
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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).

• 한국산학기술학회논문지
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• 제15권5호
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• pp.3159-3168
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• 2014

비점오염원 관리를 위한 독립호우의 결정은 월류수 처리시설의 설계에서 필수적이다. 비점오염원의 관리를 위해서는 총량을 결정해야만 하는데 이를 위해서는 결정된 독립호우에 의해 1회 평균강우량, 평균강우강도, 평균지속시간 등의 강우특성의 분석이 실시되어야만 한다. 독립호우의 결정은 무강우 지속시간의 산정(Interevent Time Definition, IETD)에 따라 분리할 수 있으며 이를 결정하기 위한 기존의 분석방법에는 자기상관 분석, 변동계수 분석, 연강우 평균발생횟수 분석 등이 있다. 본 연구에서는 기존의 IETD 분석방법에 따라 무강우시간을 산정한 후 방법별 문제점을 고찰하고 새로운 IETD 결정방법으로 지수함수 검정방법을 제안하였다. 또한, 검정방법을 통하여 결과값의 적절성을 검토하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권9호
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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.

• Communications for Statistical Applications and Methods
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• 제15권5호
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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.

• 대한약침학회지
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• 제4권1호
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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.