• Title/Summary/Keyword: Synthetic

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Studies on the Stochastic Generation of Long Term Runoff (2) (장기유출량의 추계학적 모의 발생에 관한 연구 (II))

  • 이순혁;맹승진;박종국
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.35 no.3
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    • pp.117-129
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    • 1993
  • This study was conducted to get reasonable and abundant hydrological time series of monthly flows simulated by a best fitting stochastic simulation model for the establishment of rational design and the rationalization of management for agricultural hydraulic structures including reservoirs. Comparative analysis carried out for both statistical characteristics and synthetic monthly flows simulated by the multi-season first order Markov model based on Gamma distribution which is confirmed as good one in the first report of this study and by Harmonic synthetic model analyzed in this report for the six watersheds of Yeong San and Seom Jin river systems. 1.Arithmetic mean values of synthetic monthly flows simulated by Gamma distribution are much closer to the results of the observed data than those of Harmonic synthetic model in the applied watersheds. 2.In comparison with the coefficients of variation, index of fluctuation for monthly flows simulated by two kinds of synthetic models, those based on Gamma distribution are appeared closer to the observed data than those of Harmonic synthetic model both in Yeong San and Seom Jin river systems. 3.It was found that synthetic monthly flows based on Gamma distribution are considered to give better results than those of Harmonic synthetic model in the applied watersheds. 4.Continuation studies by comparison with other simulation techniques are to be desired for getting reasonable generation technique of synthetic monthly flows for the various river systems in Korea.

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An Experimental Study on Variations of Exhaust Gas Temperature and Concentration with Synthetic Gas Combustion in Exhaust Manifold (배기관에서의 합성가스 연소에 따른 배기가스 온도 및 농도 변화에 관한 실험적 연구)

  • Cho, Yong-Seok;Lee, Seang-Wock;Yang, Seung-Il;Song, Chun-Sub;Park, Young-Joon
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.4
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    • pp.56-62
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    • 2008
  • A synthetic gas reformed from hydrocarbon-based fuels consists of $H_2$, CO and $N_2$. Hydrogen contained in the synthetic gas is a very useful species in chemical processes, due to its wide flammability range and fast burning speed. The ESGI (Exhaust Synthetic Gas Injection) technology is developed to shorten the light-off time of three way catalysts through combustion of the synthetic gas in the exhaust manifold during the cold start period of SI engines. Before the ESGI technology is applied to the test engine, the authors set a test rig that consists of gas temperature and composition controllers, an exhaust pulse generator and an exhaust manifold with a visualization window, in order to optimize the point and conditions of injection of the synthetic gas. Through measuring burned gas temperatures and taking photographs of synthetic gas combustion at the outlet of the exhaust manifold, the authors tried to find the optimal injection point and conditions. Analysis of burned gas composition has been performed for various $O_2$ concentrations. As a result, when the synthetic gas is injected at the port outlet of the cylinder No. 4 and $O_2$ concentration exceeds 4%, combustion of the synthetic gas is strong and effective in the exhaust manifold.

Flow Control of Smart UAV Airfoil Using Synthetic Jet Part 2 : Flow control in Transition Mode Using Synthetic Jet (Synthetic jet을 이용한 스마트 무인기(SUAV) 유동제어 Part 2 : 천이 비행 모드에서 synthetic jet을 이용한 유동제어)

  • Kim, Min-Hee;Kim, Sang-Hoon;Kim, Woo-Re;Kim, Chong-Am;Kim, Yu-Shin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.12
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    • pp.1184-1191
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    • 2009
  • In order to reduce the download around the Smart UAV(SUAV) at Transition mode, flow control using synthetic jet has been performed. Many of the complex tilt rotor flow features are captured including the leading and trailing edge separation, and the large region of separated flow beneath the wing. Based on the results of part 1 of the present work, synthetic jet is located at 0.01c, $0.95c_{flap}$ and it is operated with the non-dimensional frequency of 0.5, 5 to control the leading edge and trailing edge separation. Consequently, download is substantially reduced compared to with no control case at transition mode using leading edge jet only. The present results show that the overall flight performance and stability of the SUAV can be remarkably improved by applying the active flow control strategy based on synthetic jet.

Electrical Conductivity of Chemically Reduced Graphene Powders under Compression

  • Rani, Adila;Nam, Seung-Woong;Oh, Kyoung-Ah;Park, Min
    • Carbon letters
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    • v.11 no.2
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    • pp.90-95
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    • 2010
  • Carbon materials such as graphite and graphene exhibit high electrical conductivity. We examined the electrical conductivity of synthetic and natural graphene powders after the chemical reduction of synthetic and natural graphite oxide from synthetic and natural graphite. The trend of electrical conductivity of both graphene (synthetic and natural) was compared with different graphite materials (synthetic, natural, and expanded) and carbon nanotubes (CNTs) under compression from 0.3 to 60 MPa. We found that synthetic graphene showed a marked increment in electrical conductivity compared to natural graphene. Interestingly, the total increment in electrical conductivity was greater for denser graphite; however, an opposite behavior was observed in nanocarbon materials such as graphene and CNTs, probably due to the differing layer arrangement of nanocarbon materials.

Synthetic approach to the generation of antibody diversity

  • Shim, Hyunbo
    • BMB Reports
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    • v.48 no.9
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    • pp.489-494
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    • 2015
  • The in vitro antibody discovery technologies revolutionized the generation of target-specific antibodies that traditionally relied on the humoral response of immunized animals. An antibody library, a large collection of diverse, pre-constructed antibodies, can be rapidly screened using in vitro display technologies such as phage display. One of the keys to successful in vitro antibody discovery is the quality of the library diversity. Antibody diversity can be obtained either from natural B-cell sources or by the synthetic methods that combinatorially generate random nucleotide sequences. While the functionality of a natural antibody library depends largely upon the library size, various other factors can affect the quality of a synthetic antibody library, making the design and construction of synthetic antibody libraries complicated and challenging. In this review, we present various library designs and diversification methods for synthetic antibody library. From simple degenerate oligonucleotide synthesis to trinucleotide synthesis to physicochemically optimized library design, the synthetic approach is evolving beyond the simple emulation of natural antibodies, into a highly sophisticated method that is capable of producing high quality antibodies suitable for therapeutic, diagnostic, and other demanding applications. [BMB Reports 2015; 48(9): 489-494]

Development of VSI Synthetic Control Chart (가변샘플링기법을 이용한 합성관리도의 개발)

  • Song, Suh-Ill;Park, Hyun-Kyu
    • Journal of Korean Society for Quality Management
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    • v.33 no.1
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    • pp.1-10
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    • 2005
  • This paper develops a new VSI $\={X}-CRL$ synthetic control chart that considers convenience of use in the field, and perception of change of process applying VSI techniques to synthetic control chart, simultaneously. We found the optimal sampling interval and various control limit factor of the suggested chart using markov chain. Comparison and analysis is carried out between synthetic VSI $\={X}-CRL$ chart and other chart in the statistical aspect; $\={X}$ control chart, VSI $\={X}$ chart, another synthetic chart. In case that the process follows normal distribution, the proposed VSI $\={X}-CRL$ synthetic control chart in detecting process mean shift showed the best performance in aspect of statistical performance, regardless of control limit L of CRL/S control chart.

A Synthetic Aperture Focusing Method for Three-way Dynamic Focusing

  • Kim Jung-Jun;Chang Jin-Ho;Song Tai-Kyong
    • Journal of Biomedical Engineering Research
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    • v.26 no.1
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    • pp.31-35
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    • 2005
  • A novel synthetic aperture method for real-time three-way dynamic focusing is proposed, which provides lateral beam patterns represented as the product of Fourier transforms of transmit subaperture, receive subaperture, and a synthetic window function. In the proposed method, all array elements are fired individually and for each firing echo signals are recorded from all elements of a receive subaperture moving along an array with the transmit element. The three-way dynamic focusing is then achieved by employing a synthetic aperture algorithm for two-way dynamic focusing and a synthetic focusing method for transmit dynamic focusing. Both theoretical analysis and computer simulation results show that the proposed method produces ultrasound beams with improved lateral resolution at all depths compared to the conventional phased array imaging and synthetic aperture focusing methods.

Synthetic Image Generation for Military Vehicle Detection (군용물체탐지 연구를 위한 가상 이미지 데이터 생성)

  • Se-Yoon Oh;Hunmin Yang
    • Journal of the Korea Institute of Military Science and Technology
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    • v.26 no.5
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    • pp.392-399
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    • 2023
  • This research paper investigates the effectiveness of using computer graphics(CG) based synthetic data for deep learning in military vehicle detection. In particular, we explore the use of synthetic image generation techniques to train deep neural networks for object detection tasks. Our approach involves the generation of a large dataset of synthetic images of military vehicles, which is then used to train a deep learning model. The resulting model is then evaluated on real-world images to measure its effectiveness. Our experimental results show that synthetic training data alone can achieve effective results in object detection. Our findings demonstrate the potential of CG-based synthetic data for deep learning and suggest its value as a tool for training models in a variety of applications, including military vehicle detection.

A Procedural Theory of Concepts and the Problem of Synthetic a priori

  • Duzi, Marie;Materna, Pavel
    • Korean Journal of Logic
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    • v.7 no.1
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    • pp.1-22
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    • 2004
  • The Kantian idea that some judgments are synthetic even in the area of a priori judgments cannot be accepted in its original version, but a modification of the notions 'analytic' and 'synthetic' discovers a rational core of that idea. The new definition of 'analytic' concerns concepts and makes it possible to distinguish between analytic concepts, which are effective ways of computing recursive functions, and synthetic concepts, which either define non-recursive functions, or define recursive functions in an ineffective way. To justify this claim we have to construe concepts as abstract procedures not reducible to set-theoretical entities.

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Bond Characteristics of Structural Synthetic Fibers (구조용 합성섬유 표면형상에 따른 부착특성)

  • 원종필;임동휘;박찬기;한일영;김방래
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.335-340
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    • 2001
  • Recently in abroad, structural synthetic fiber developed, has been studied extensively as a substitute for steel fiber due to its properties such as corrosion-resistance, low density, good pumping, and in-place safety, etc. In this study, we conducted pull-out test, for seven different geometries of structural synthetic fibers and obtained optimum geometry for structural synthetic fiber which fully utilizes matrix anchoring without revealing fiber fracturing. According to pull-out test results, it was found that crimped type structural synthetic fiber give significant improvement in the interface toughness(roll-out enemy) and pull-out load.

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