• 조명전기설비학회논문지
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• 제28권3호
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• pp.32-43
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• 2014

This paper presents the intra capacitance modeling according to the winding method, section bobbin and coil structure for hybrid choke coil capable of the EMI attenuation of broad bands from lower frequency bands to higher frequency bands and high frequency type common-mode choke coil capable of the EMI attenuation of high frequency band used in the EMI Block of LED-TV SMPS. In case of high frequency type CM choke coil, it can be explained the parasitic capacitance of A type and section bobbin type winding methods among them is much smaller than the other. The first resonant frequency of the proposed CM choke coil tends to increase as the parasitic capacitance becomes small and its impedance characteristics also show improved performance as the first resonant frequency increases. In case of hybrid choke coil using rectangular copper wire, it has investigated its parasitic capacitance compared to CM choke coil of conventional toroidal type becomes small. Also it has confirmed through the experiment results that CE margin and RE margin in frequency bands 0.5MHz to 5MHz and 30MHz to 200MHz are respectively 10dB and 15dB greater than that of conventional type in case of one stage EMI filter structure adopting hybrid choke coil compared to two stage EMI Filter structure using two of each CM choke coil used in the lower and higher frequency bands or two of CM choke coil used in only the lower frequency bands. In the future, the hybrid choke coil and CM choke coil of high frequency type show it can be practically used in not only LED/LCD-TV SMPS but also several applications such as LED Lighting, Laptop Adapter, Server Power Supply and so on.

• ETRI Journal
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• 제37권1호
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• pp.175-185
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• 2015

This paper presents a system-of-systems (SoS) approach to the formal modeling of a cyber-physical system (CPS) for simulation-based analysis. The approach is based on a convergence technology for modeling and simulation of a highly complex system in which SoS modeling methodology, hybrid systems modeling theory, and simulation interoperation technology are merged. The methodology maps each constituent system of a CPS to a disparate model of either continuous or discrete types. The theory employs two formalisms for modeling of the two model types with formal specification of interfaces between them. Finally, the technology adapts a simulation bus called DEVS BUS whose protocol synchronizes time and exchange messages between subsystems simulation. Benefits of the approach include reusability of simulation models and environments, and simulation-based analysis of subsystems of a CPS in an inter-relational manner.

• Geomechanics and Engineering
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• 제14권5호
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• pp.479-489
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• 2018

In this paper, a comparative study of the effects of soil modelling on the interaction between tunnelling in soft soil and adjacent piled structure is presented. Several three-dimensional finite element analyses are performed to study the deformation of pile caps and piles as well as tunnel internal forces during the construction of an underground tunnel. The soil is modelled by two material models: the simple, yet approximate Mohr Coulomb (MC) yield criterion; and the complex, but reasonable hardening soil (HS) model with hyperbolic relation between stress and strain. For the former model, two different values of the soil stiffness modulus ($E_{50}$ or $E_{ur}$) as well as two profiles of stiffness variation with depth (constant and linearly increasing) were used in attempts to improve its prediction. As these four attempts did not succeed, a hybrid representation in which the hardening soil is used for soil located at the highly-strained zones while the Mohr Coulomb model is utilized elsewhere was investigated. This hybrid representation, which is a compromise between rigorous and simple solutions yielded results that compare well with those of the hardening soil model. The compared results include pile cap movements, pile deformation, and tunnel internal forces. Problem symmetry is utilized and, therefore, one symmetric half of the soil medium, the tunnel boring machine, the face pressure, the final tunnel lining, the pile caps, and the piles are modelled in several construction phases.

• 대한기계학회논문집A
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• 제23권6호
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• pp.988-1000
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• 1999

An experimental study is presented for the effect of number of terms of a pewee series type stress function on stress analysis around a hole in tensile loaded plate. The hybrid method coupling photoelastsic data inputs and complex variable formulations involving conformal mappings and analytical continuity is used to calculate tangential stress on the boundary of the hole in uniaxially loaded, finite width tensile plate. In order to measure isochromatic data accurately, actual photoelastic fringe patterns are two times multiplied and sharpened by digital image processing. For qualitative comparison, actual fringes are compared with calculated ones. For quantitative comparison, percentage errors and standard deviations with respect to percentage errors are caculated for all measured points by changing the number of terms of stress function. The experimental results indicate that stress concentration factors analyzed by the hybrid method are accurate within three percent compared with ones obtained by theoretical and finite element analysis.

• Journal of Electrical Engineering and Technology
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• 제7권4호
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• pp.564-569
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• 2012

This paper proposes a hybrid-excited linear synchronous motor (LSM) that has potential applications in a magnetically levitated vehicle. The levitation and thrust force characteristics of the LSM are investigated by means of three-dimensional (3-D) numerical electromagnetic FEM calculations and experimental verification. Compared to a conventional LSM with electromagnets, a hybrid-excited LSM can improve levitation force/weight ratios, and reduce the power consumption of the vehicle. Because the two-dimensional (2-D) FE analysis model describes only the center section of the physical device, it cannot express the complex behavior of leakage flux, which this study is able to predicts along with levitation and thrust force characteristics by 3-D FEM calculations. A static force tester for a hybrid-excited LSM has been manufactured and tested in order to verify these predictions. The experimental results confirm the validity of the 3-D FEM calculation scheme for the description of a hybrid-excited LSM.

• 한국생산제조학회지
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• 제22권5호
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• pp.871-878
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• 2013

Roll-to-roll (R2R) hot embossing systems have been developed and are widely used in various industrial domains. These systems press and heat flexible films between a press roll and a back-up roll, as said films pass through the two rolls. In previous studies, a heating roll was used for heating. However, in this study, a hybrid roll for R2R hot embossing is conceptualized and developed. This R2R system can be used for generating fine patterns on large and continuous films. The hybrid roll of our system can cool and heat the films simultaneously, thus affording greater flexibility in process design. Thermal and structural analyses were performed for developing the hybrid roll. In addition, a hybrid roll was designed based on analytical results. Experiments were conducted for measuring the performance of the developed hybrid roll.

• Journal of Power Electronics
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• 제13권5호
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• pp.757-765
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• 2013

For conventional interleaved two-phase forward converters with a common output inductor, the maximum duty cycle is 0.5, which limits the voltage range and increases the difficulty of the transformer's optimization. A new two-phase hybrid forward converter with series-parallel auto-regulated transformer windings is presented in this paper. With interleaved control signals for the two phases, the secondary windings of the transformers can work in series when the duty cycle is larger than 0.5, and they can work in parallel when duty cycle is lower than 0.5. Therefore, the maximum duty cycle is extended and the turns ratio of the transformer can be optimized. Duty cycle dependent auto-regulated windings result in the steady states of the converter being different in different duty cycle ranges (D>0.5 and D<0.5). Fortunately, the steady state gains of the proposed hybrid converter are identical at different duty cycle ranges, which means a stepless shift between two states. A prototype is built to verify the theoretical analysis. A conventional control loop is compatible for the whole input voltage range and load range thanks to the stepless shifting between the different duty cycle ranges.

• 자연과학논문집
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• 제15권1호
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• pp.79-88
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• 2005

효모에는 여러 가지 종류의 thiol peroxid se 동위 효소들인 cytoplasmic TPx I, cTPx II, cTPx III, mitochodrial TPx (mTPx), 및 nuclear TPx (nTPx)가 존재하고 있다. 특히 cTPx II는 다른 효모TPx와 비교해 볼 때 매우 낮은 peroxidase 활성을 보이나, cTPx II를 제거한 cTPx II mutant균주는 심하게 성장이 저해되는 특징을 보인다. 본 연구에서는 효모에서의 cTPx II의 생리학적 기능을 밝히는 연구의 첫 과정으로 cTPx II와 상호 작용하는 단백질을 탐색하였다. Sacchromyces cerevisiae genomic DNA library에서 yeast two-hybrid system을 이용하여 cTPx II와 상호 결합하는 단백질을 탐색하여 그 단백질들의 기능을 연구하여, 궁극적으로 cTPx II의 생리기능을 밝히는데 이 연구의 목적을 두었다.

• Steel and Composite Structures
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• 제17권6호
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• pp.803-824
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• 2014

The dynamic characterization is important in making accurate predictions of the seismic response of the hybrid structures dominated by different damping mechanisms. Different damping characteristics arise from the construction of the tower with different materials: steel for the upper part; reinforced concrete for the lower main part and interaction with supporting soil. The process of modeling damping matrices and experimental verification is challenging because damping cannot be determined via static tests as can mass and stiffness. The assumption of classical damping is not appropriate if the system to be analyzed consists of two or more parts with significantly different levels of damping, such as steel/concrete mixed structure - supporting soil coupled system. The dynamic response of structures is critically determined by the damping mechanisms, and its value is very important for the design and analysis of vibrating structures. An analytical approach capable of evaluating the equivalent modal damping ratio from structural components is desirable for improving seismic design. Two approaches are considered to define and investigate dynamic characteristics of hybrid tower of cable-stayed bridges: The first approach makes use of a simplified approximation of two lumped masses to investigate the structure irregularity effects including damping of different material, mass ratio, frequency ratio on dynamic characteristics and modal damping; the second approach employs a detailed numerical step-by step integration procedure in which the damping matrices of the upper and the lower substructures are modeled with the Rayleigh damping formulation.

• 한국어류학회지
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• 제29권1호
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• pp.1-12
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• 2017

낙동강 상류 지류인 황지천에서 쉬리(Coreoleuciscus splendidus)와 참쉬리(C. aeruginosa)의 종 간 자연잡종 개체를 채집하였다. 쉬리와 참쉬리의 종 간 잡종 개체는 외부형태 비교와 함께 핵 DNA의 RAG1 유전자(1,334 bp)와 미토콘드리아 DNA인 CO1 유전자(1,551 bp)를 이용한 염기서열 분석을 실시하였다. 외부형태 분석결과 잡종 개체는 등지느러미, 꼬리지느러미 및 뒷지느러미 3곳에서 지느러미 반문의 형태가 쉬리와 참쉬리의 중간 형태를 나타내었다. RAG1과 CO1 유전자를 이용한 분자계통 분석결과 황치천에 분포하는 쉬리속 어류는 쉬리, 참쉬리 두 종과 두 종 간의 잡종 개체군으로 구성되어 있음을 확인하였으며, CO1 유전자의 염기서열 분석결과 순종인 정교배체와 잡종인 상반교배체가 잘 구분되었다. 또한 RAG1 유전자 분석결과 13개의 염기서열 변이를 확인하였고, 잡종 개체는 9개의 염기서열에서 double peaks가 확인되었다. 유전학적 분석과 외부형태 변이 분석에 의해 쉬리와 참쉬리 사이에 잡종화가 발생한 것을 확인하였으나 잡종 F2세대와 잡종 F1 세대의 생식적 격리 여부는 확인하지 못하였다.