• 한국전산유체공학회:학술대회논문집
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• 1999.11a
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• pp.71-76
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• 1999

The base flow regions of a three-body sounding rocket containing multiple exhaust plumes were numerically investigated in three dimensions for a free stream Mach number of 2.7 at flight altitude 18.5 km. The flowfields were calculated using the full compressible Navier-Stokes equations with an one-equation turbulence model of Baldwin-Earth. The present calculations were executed based upon a chemically frozen, single perfect gas model assumption. Due to the symmetry of the three-body rocket of each single nozzle, only one fourth of the computational domain was considered for the analysis. The results indicate that a babe heating effect is not considerable due to the small expansion of the plumes. In the base, however, a low speed recirculating flow dominates the region.

• Journal of Sensor Science and Technology
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• v.24 no.1
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• pp.1-5
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• 2015

The V-grooved single-mode fiber in which a surface part of the core was removed was investigated as a quasi-distributed water detection sensor. In the normal state, the V-grooved region is filled and covered with a specific RI (Refractive Index)-matched medium, and the sensor experiences minimal optical loss. As water invades the V-grooved region, the material is dissolved and removed, and a considerable optical loss occurs owing to the large RI difference between the fiber core and water. The experimental results showed the feasibility of the device as a sensor element of the quasi-distributed water detection sensor system based on general optical time domain reflectometry (OTDR).

• Journal of Sensor Science and Technology
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• v.14 no.3
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• pp.169-179
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• 2005

A multiplexed bend loss type single-mode fiber-optic sensor system was prepared to measure the displacement of several cm of the civil engineering structures such as many bridges, tunnels and various buildings. This bend loss type fiber-optic sensor used the signal difference between two reflection signals due to various bend losses generating at a pair of optical connectors by using OTDR (optical time domain reflectometer) for measuring displacements. And the experiments were conducted for showing the measurement feasibility on the range of 10 cm, and the multiplexing experiments were also performed to measure the displacements of 5 measuring positions of an object by setting these 5 fiber-optic sensors on a single mode fiber simultaneously.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.5
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• pp.1638-1653
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• 2014

A sequential optimization algorithm (SOA) for resource allocation in a cyclic-prefixed single-carrier cognitive relay system is proposed in this study. Both subcarrier pairing (SP) and power allocation are performed subject to a primary user interference constraint to minimize the mean squared error of frequency-domain equalization at the secondary destination receiver. Under uniform power allocation at the secondary source and optimal power allocation at the secondary relay, the ordered SP is proven to be asymptotically optimal in maximizing the matched filter bound on the signal-to-interference-plus-noise ratio. SOA implements the ordered SP before power allocation optimization by decoupling the ordered SP from the power allocation. Simulation results show that SOA can optimize resource allocation efficiently by significantly reducing complexity.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.79-81
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• 1987

Expert systems have a variety of potential applications in process control. The application domain ranges from the entire plant system to a single loop system. Both, off-line and real-time problems may be realized. In this paper, expert system is employed as a part of a single control loop of PID Controller with self-tuning. The goal of expert system in the present study is to build up the necessary process knowledge required for efficient control. In order to achieve this process, the development of an expert system and a prototype model is carried out. OPS5, a rule based production system, is utilized in experiment, and common LISP is used for man-machine interface.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.5
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• pp.349-353
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• 1999

In this paper, to fabricate the AC power electroluminescent device (PELD) with high brightness, new structure that constructed single emissive layer between electrodes was proposed. Dielectric and phosphor material structure that constructed single emissive layer between electrodes was proposed. Dielectric and phosphor material were BaTiO3 and ZnS:Cu respectively. Fabricated AC power EL devices were estimated by optical and electrical properties of EL spectrum, brightness, CIE coordinate system, transferred charge density and EL emission wave in time domain. With above results, we found that brightness of newly proposed AC powder EL power EL device was 2754 cd/m2 at 100V, 400 Hz and compared with conventional device structure.

• Journal of the Korean Magnetic Resonance Society
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• v.20 no.3
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• pp.66-70
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• 2016

The replication protein A (RPA), is a heterotrimer with 70, 32 and 14 kDa subunits and plays a crucial role in DNA replication, recombination, and repair. The largest subunit, RPA70, binds to single-stranded DNA (ssDNA) and mediates interactions with many cellular and viral proteins. In this study, we performed nuclear magnetic resonance experiments on the complex of the DNA binding domain A of human RPA70 (RPA70A) with ssDNA, d(CCCCC), at various temperatures, to understand the temperature dependency of ssDNA binding affinity of RPA70A. Essential residues for ssDNA binding were conserved while less essential parts were changed with the temperature. Our results provide valuable insights into the molecular mechanism of the ssDNA binding of human RPA.

• Proceedings of the KIEE Conference
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• summer
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• pp.276-279
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• 2004

The purpose of this paper is to describe and demonstrate how a utility-connectable inverter for photovoltaic or fuel-cell applications can be well modeled using PSCAD/EMTDC. In this paper, a single-phase IGBT inverter using SPWM is modeled. Simple voltage magnitude and phase controls are implemented using PSCAD's Pl controller, PLL, and a 'user defined' component called Modulo (found in their extensive collection of example circuits). The circuit model also takes advantage of PSCAD's interpolated firing pulse option, which provides improved simulation results by preventing errors from being introduced when switches fire between time simulation steps. Additionally, SCAD's Online Frequency Scanner for FFT is utilized for a demonstration of PSCAD's frequency-domain analysis capabilities.

• Journal of Korea Multimedia Society
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• v.22 no.8
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• pp.930-939
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• 2019

High-Level Architecture(HLA)/Run-Time Infrastructure(RTI) are standards for distributed simulation systems and offer a technology to interconnect them and form one single simulation system. In defense domain, M&S is the only way to prove effectiveness of weapon systems except for Live Fire Testing (LFT). This paper focuses on guided missile simulations in weapon systems for engagement analyses and proposes the integrated flying vehicle model that is based on HLA/RTI. There are a lot of missiles in real world; therefore, we should develop each missile models in M&S in order to apply battlefield scenarios. To deal with the difficulties, in this paper, firstly, I classify these missiles into three models: ballastic, cruise, and surface-to-air missile models, and then I design each missile model and integrates them into a single model. This paper also offers a case study with my integrated flying vehicle model. At the conclusion, this paper presents contributions of this paper.

• Journal of Auto-vehicle Safety Association
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• v.12 no.4
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• pp.70-77
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• 2020

In this study, we estimate the vehicle speed by analyzing the acoustic data recorded in a single microphone of a surveillance camera. The frequency analysis of the acoustic data corrects the Doppler effect, which is a characteristic of the moving sound source, and reflects the geometric relationship according to the location of the sound source and the microphone on the two-dimensional plane. The acoustic data is selected from the horn sound that is mainly observed in an urgent situation among various sound sources that may occur in a traffic accident, and the characteristics of the monotone source are considered. We verified the reliability of the proposed method by time domain acoustic analysis and actual vehicle evaluation. This method is effective and can be used for traffic accident analysis in the blind spot of the camera using a single microphone built into the existing surveillance camera.