• 자연과학논문집
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• 제12권1호
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• pp.61-67
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• 2002

물벼룩(Daphnia magna)과 클로렐라(Chlorella vulgaris)가 포함된 microcosm에서 독성오염물질인 페놀과 코발트를 첨가함에 따라 구조적 exergy가 감소되었다. microcosm의 구성 생물들의 생물량이나 군집 전체의 생물량보다 구조적 exergy가 훨씬 크게 변화되었다. 이것은 구조적 exergy가 생태계의 안정성을 평가하는 지표가 될 수 있음을 나타내는 것이다.

• Journal of Magnetics
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• 제21권4호
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• pp.629-634
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• 2016

In this study, we evaluate the performance of permanent magnets (PMs). The efficiency of attraction in the high speed region was studied using the Variable Flux Memory Motor (VFMM). It is presented in order to analyze the magnetic characteristics of PMs, using the second quadrant plan data with re- and demagnetization. In addition, this study focuses on the evaluation of operational characteristics relative to the magnetizing directions according to the d-axis currents, by using one of the finite element solutions. The feasibility of application for the VFMM has been experimentally demonstrated.

• 한방안이비인후피부과학회지
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• 제12권2호
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• pp.148-160
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• 1999

In order to strengthen objectivity and availability of oriental herb medicine, the standard formula for herbs has been attempted to set up by documentary testing original herbs which were recorded in authorized document. The object herb medicines are CARYOPHYLLI FLOS. After this study, additional experimental verification is required as a matter of fact. As comparison materials, this thesis will be utilized. Specially the internal and external morphological standard in this study is expected to supply the search for several physiochemical reaction, biological reaction, determination of indicator material and identification of gene with basic sources in the future.

• Nuclear Engineering and Technology
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• 제49권5호
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• pp.1019-1030
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• 2017

Diffusion is a crucial mechanism that regulates the migration of radioactive nuclides. In this study, an innovative numerical method was developed to simultaneously calculate the diffusion coefficient of both parent and, afterward, series daughter nuclides in a sequentially reactive through-diffusion model. Two constructed scenarios, a serial reaction (RN_1 ${\rightarrow}$ RN_2 ${\rightarrow}$ RN_3) and a parallel reaction (RN_1 ${\rightarrow}$ RN_2A + RN_2B), were proposed and calculated for verification. First, the accuracy of the proposed three-member reaction equations was validated using several default numerical experiments. Second, by applying the validated numerical experimental concentration variation data, the as-determined diffusion coefficient of the product nuclide was observed to be identical to the default data. The results demonstrate the validity of the proposed method. The significance of the proposed numerical method will be particularly powerful in determining the diffusion coefficients of systems with extremely thin specimens, long periods of diffusion time, and parent nuclides with fast decay constants.

• 대한임베디드공학회논문지
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• 제6권2호
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• pp.100-107
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• 2011

As the use of mobile multimedia devices is increasing in the recent year, the needs for high-performance multimedia processors are increasing. In this regard, we propose a SIMD (Single Instruction Multiple Data) based parallel processor that supports high-performance multimedia applications with low energy consumption. The proposed parallel processor consists of 16 processing elements(PEs) and operates on a 3-stage pipelining. Experimental results for the JPEG encoding algorithm indicate that the proposed parallel processor outperforms conventional parallel processors in terms of performance and energy efficiency. In addition, the proposed parallel processor architecture was developed and verified with verilog HDL and a FPGA prototype system.

• 전력전자학회논문지
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• 제24권1호
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• pp.16-24
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• 2019

The performance of the battery management system (BMS) algorithm is important for ensuring the stability and efficient operation of battery packs. Such a performance is determined by the internal parameters of the electrical equivalent circuit model (EECM). This study proposes a performance improvement and verification of battery parameters for the BMS algorithm using electrical experiments and tools. The parameters were extracted through electrical characteristic experiments, and an EECM based on Ah counting was designed. Simulation results using the EECM were compared with actual experimental data to determine the best parameter extraction method.

• 한국공간구조학회논문집
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• 제19권3호
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• pp.101-109
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• 2019

In order to develop the compatible damping device in various vibration source, a hybrid wall-type damper combining slit and friction damper in parallel was developed. Cyclic loading tests and two-story RC reinforced frame tests were performed for structural performance verification. As a result of the 5-cyclic loading test according to KBC-2016 and low displacement cyclic fatigue test, The hybrid wall type damper increased its strength and the ductility was the same as that of the slit damper. In addition, As a result of the two-layer frame test, the reinforced frame had about twice the strength of the unreinforced frame, and the story drift ratio was satisfied to Life Safety Level.

• Nuclear Engineering and Technology
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• 제51권1호
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• pp.31-44
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• 2019

This study simulated a control rod assembly (CRA), which is a part of reactor shutdown systems, in immersed and fluid flow conditions. The CRA was inserted into the reactor core within a predetermined time limit under normal and abnormal operating conditions, and the CRA (which consists of complex geometric shapes) drop behavior is numerically modeled for simulation. A full-scale prototype CRA drop test is established under room temperature and water-fluid conditions for verification and validation. This paper describes the details of the numerical modeling and analysis results of the several conditions. Results from the developed numerical simulation code are compared with the test results to verify the numerical model and developed computer code. The developed code is in very good agreement with the test results and this numerical analysis model and method may replace the experimental and CFD method to predict the drop behavior of CRA.

• Journal of Power Electronics
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• 제19권3호
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• pp.714-726
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• 2019

This paper proposes a hybrid-boost Modular Multilevel Converter (MMC) for the Medium-Voltage (MV) Variable Speed Drives (VSDs) employed in subsea applications, such as oil and gas recovery. In the presented architecture, a hybrid-boost MMC with a reduced number of semiconductor devices driving a multiphase Induction Machine (IM) is investigated. The stepped output voltage generated by the MMC reduces or eliminates the filtering requirements. Moreover, the boosting capability of the proposed architecture eliminates the need for bulky low-frequency transformers at the converter output terminals. A detailed illustration of the hybrid-boost MMC operation, the expected limitations/constraints, and the voltage balancing technique are presented. A simulation model of the proposed MV hybrid-boost MMC-based five-phase IM drive has been built to investigate the system performance. Finally, a downscaled prototype has been constructed for experimental verification.

• Current Optics and Photonics
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• 제5권1호
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• pp.23-31
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• 2021

We propose a wheel screen type Lamina 3D display, which realizes a 3D image that can satisfy the accommodation cue by projecting volumetric images encoded by varying polarization states to a multilayered screen. The proposed system is composed of two parts: an encoding part that converts depth information to states of polarization and a decoding part that projects depth images to the corresponded diffusing layer. Though the basic principle of Lamina displays has already been verified by previous studies, those schemes suffered from a bottleneck of inferior resolution of the 3D image due to the blurring on the surfaces of diffusing layers in the stacked volume. In this paper, we propose a new structure to implement the decoding part by adopting a form of the wheel screen. Experimental verification is also provided to support the proposed principle.