• 제어로봇시스템학회논문지
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• 제11권6호
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• pp.558-563
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• 2005

In this paper, we implemented a web-based virtual laboratory system(VLab system) with creative and interactive multimedia contents, which can be used to enhance the quality of education in the area of digital logic circuits. Since the proposed VLab system is implemented to describe the on-campus laboratory, the learners can obtain similar experimental data through it. Also, the VLab system is designed to increase the learning and teaching efficiencies of both the learners and the educators, respectively. The learners will be able to achieve high teaming standard and the educators save their time and labor. The virtual experiments on our VLab system are performed according to the following procedure: (1) Circuit composition on the virtual bread board (2). Applying input voltage (3) Output measurements (4) Checkout of experiment results. Furthermore, the circuit composition on the virtual bread board and its corresponding online schematic diagram are displayed together on the VLab system for the learner's convenience. Finally, we have obtained several affirmative effects such as reducing the total experimental hours and the damage rate for experimental equipments and increasing learning efficiencies as well as faculty productivity.

• Journal of Advanced Marine Engineering and Technology
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• 제33권2호
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• pp.259-266
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• 2009

An experimental study was conducted to investigate the effects of forcing amplitude on the flow structure near the nozzle exit of forced jet diffusion flames. The jet was excited up to the blowout occurrence by a considerable large amplitude with a periodic velocity fluctuation at the tube resonating frequency. In the attached flame regime, we disclosed the very interesting result newly that adding of a moderate forcing amplitude caused the jet flame to become longer in spite of being forced. Particular attention is focused on the turnabout mechanism of vortex roll-up around the elongated flame, which has not been reported previously, and on the inner coherent structure of the forced jet in the attached flame regime. From the velocity and flow visualization results, it was ascertained that the surrounding air due to the occurrence of negative velocity parts was suck into the fuel nozzle. To aid in understanding the rotating phenomenon of coherent structure, we present a schematic diagram of the turnabout mechanism of vortex roll-up. The mechanism of vortex turnabout phenomenon can be easily understood by considering the positive and negative velocity amplitudes about the instantaneous velocity of the forcing flow, as shown in this diagram.

• 센서학회지
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• 제21권3호
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• pp.172-179
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• 2012

This paper presents the design and analysis of a vibration-driven electromagnetic energy harvester that uses a multi-pole magnet. The physical backgrounds of the vibration electromagnetic energy harvester are reported, and an ANSYS finite element analysis simulation has been used to determine the different alignments of the magnetic pole array with their flux lines and density. The basic working principles for a single and multi-pole magnet are illustrated and the proposed harvester has been presented in a schematic diagram. Mechanical parameters such as input frequency, maximum displacement, number of coil turns, and load resistance have been analyzed to obtain an optimized output power for the harvester through theoretical study. The paper reports a maximum of 1.005 mW of power with a load resistance of $1.9k{\Omega}$ for 5 magnets with 450 coil turns.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전력기술부문
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• pp.95-99
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• 2001

Frequency is the unique physical value for all the interconnected systems. Therefore. the load frequency control is in the responsibility of all members in the interconnection power unbalance in one of the interconnected system can cause the problems in others. In the following text a brief description and the role of frequency in an interconnected system will be presented. Following is the short description of the Balkan Interconnection (UCTE Second Synchronous Zone) with schematic diagram. A Power-Frequency (P-f) dynamic model of a control area wil1 be shown. Model gives the analytical solution for frequency change versus a time after outage of a generator in the power system. This model will be applied to the Balkan Interconnection and compared with numerical approach. Advantages and drawbacks of the analytical method will be discussed Purpose of using this model is to investigate if the pumps in reversible hydropower plant will be underfrequency shed after the outage of the biggest generator unit in the interconnection, according %o (n-1) security postulate.

• Steel and Composite Structures
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• 제24권4호
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• pp.383-390
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• 2017

This paper highlights the experimental and numerical investigations performed on a tubular T-joint fabricated from circular hollow sections under axial compressive loads applied at the brace. Tests were performed on a reference joint and the joint wrapped with Carbon Fiber Reinforced Polymer (CFRP). The Nitowrap EP carbon fiber with Nitowrap 410 resin serve as a composite material is used for wrapping the T-joint. Schematic diagram of the fabricated tubular joint for the experimental test setup, along with the experimental and numerical results are presented. After performing these experiments, it has been demonstrated that the joint wrapped with CFRP has a better strength and lesser deflection than a reference joint. Finite element analysis carried out in Ansys reveals that the results were in good correlation with the experimental values.

• 한국초전도ㆍ저온공학회논문지
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• 제4권1호
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• pp.8-12
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• 2002

Since the high performance analog-to-digital converter can be built with Rapid Single Flux Quantum (RSFQ) logic circuits the development of superconductive analog-to-digital converter has attracted a lot of interests as one of the most prospective area of the application of Josephson Junction technology. One of the main advantages in using Rapid Sng1e Flux Quantum logic in the analog-to-digital converter is the low voltage output from the Josephson junction switching, and hence the high resolution. To design an analog-digital converter, first we have used XIC tool to compose a circuit schematic, and then studied the operational principle of the circuit with WRSPICE tool. Through this process, we obtained the proper circuit diagram of an 1-bit analog-digital converter circuit. The optimized circuit was laid out as a mask drawing. Inductance values of the circuit layout were calculated with L-meter.

• Molecules and Cells
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• 제46권11호
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• pp.672-674
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• 2023

Schematic diagram of the interaction between the intestinal muscularis externa (MMΦ) macrophages and the enteric nervous system (ENS) neurons during different developmental periods. At the early postnatal stage, MMΦs play a critical role in ENS maturation and refinement through synaptic pruning and enteric neuron phagocytosis. In addition, during the adult stage, a specific MMΦ subset named neuron-associated (NA)-MMΦ, supports enteric neuronal survival and functions. Conversely, enteric neurons promote the phenotypic MMΦ changes by secreting transforming growth factor-β (TGFβ), transitioning them from a phagocytic phenotype in the early postnatal period to a neuroprotective and immune-surveillant phenotype in the young adult period. Disruptions in these interactions could lead to alterations in the enteric neuron numbers, ultimately resulting in reduced gut motility.

• 대한조선학회논문집
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• 제55권1호
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• pp.83-91
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• 2018

In this paper, usefulness of marine radar for water waves measurement in coastal waters is presented. We installed a marine radar to acquire radar images of water wave around light beacon at Jujeon in Ulsan. Also, a series of analysis procedures for obtaining the wave information from the acquired image is described with a schematic diagram. We compared analysis results of radar images with measurement values using wave height gauge at light beacon. In order to improve accuracy of analysis results, detailed water depth information is essential. In conclusion, in case of the use of radar for water waves measurement, it is shown that it is very necessary to increase the accuracy of measurement by consideration of the water depth in the dispersion relation of water waves.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.682-685
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• 2009

Several studies are being carried out to develop the reliable methods for the gas hydrate resource evaluation around the world. In this study, some case studies and investigations on the resource assesment of several advanced research teams were tried and then detail information on the evaluation scheme and technology of each team and nation are explained and analyzed for the future study and development. On top of that, main concepts and major parameters which can affect the quantity of assessment are examined and arranged for applying to our Donghae gas hydrate field case. Finally, the major concepts and methodology for this evaluation are brought forth and a schematic diagram for the main steps are come up with as well.

• 한국안전학회지
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• 제15권4호
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• pp.47-55
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• 2000

In this modern age which electric energy is the fundamental source of energy in the industry, electric shock disasters are unavoidable. Although numerous efforts, time, and money have been invested to prevent such electric shock disasters, the number of electric shock disasters are on the increase. In this study, models for equivalent electric circuit are developed for the different types of electric shock which are classified into three groups. The objective of these models is to calculate the electric current flowing through the body at the time of the shock. Based on the analysis, countermeasures to prevent the shock are suggested. The data used in this study are based on 28 actual incidents which occurred in the Daegu area during January of 1995 through June of 1999. The results of this study can be used as a technical manual for workers treating electrical facilities.