• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1921-1926
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• 2003

We build a local minimum free motion planning for mobile robots considering dynamic environments by simple sensor fusion assuming that there are unknown obstacles which can be detected only partially at a time by proximity sensors and can be cleaned up or moved slowly (dynamic environments). Potential field is used as a basic platform for the motion planning. To clear local minimum problem, the partial information on the obstacles should be memorized and integrated effectively. Sets of linked line segments (SLLS) are proposed as the integration method. Then robot's target point is replaced by virtual target considering the integrated sensing information. As for the main proximity sensors, we use laser slit emission and simple web camera since the system gives more continuous data information. Also, we use ultrasonic sensors as the auxiliary sensors for simple sensor fusion considering the advantages in that they give exact information about the presence of any obstacle within certain range. By using this sensor fusion, the dynamic environments can be dealt easily. The performance of our algorithm is validated via simulations and experiments.

• Vacuum Magazine
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• v.4 no.1
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• pp.16-23
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• 2017

Recently, KSTAR, Korea's superconducting fusion energy research and development device, has succeeded in driving the high performance plasma for 70 seconds for the first time in the world. Continuous plasma operation technology is an essential factor for commercialization of fusion energy power generation. Therefore, this achievement is expected to play a major role in the research of fusion technology required for future fusion power plants. In order to operate the KSTAR, the discharge process in which the neutral gas is turned into the plasma should be preceded in the start-up (breakdown) phase of tokamak operation. This process essentially involves the vacuum environment in the tokamak device. KSTAR has successfully operated a vacuum pumping system to achieve the target level of the vacuum environment through a high temperature baking operation, a discharge cleaning process and boronization.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4337-4340
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• 2011

The vitamin D receptor binding peptide, VDRBP, was overexpressed as a fused form with the ubiquitin molecule in Rosetta(DE3)pLysS, a protein production strain of Escherichia coli harboring an induction controller plasmid. The fusion protein was bound to the immobilized metal ions, and the denaturation and renaturation of the fusion protein were performed as a part of the purification procedure. After the elution of the fusion protein, the peptide hormone was released from its fusion partner by using yeast ubiquitin hydrolase (YUH), and subsequently purified by reverse phase chromatography. The purity of the resulting peptide fragment was checked by MALDI-TOF mass and NMR spectroscopy. The final yields of the target peptide were around 5 and 2 mg per liter of LB and minimal media, respectively. The recombinant expression and purification of this peptide will enable structural and functional studies using multidimensional NMR spectroscopy and X-ray crystallography.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.4 s.23
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• pp.24-31
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• 2005

This paper presents an implementation of a real-time multi-sensor data fusion algorithm for Flight Test Computer. The sensor data consist of positional information of the target from a radar, a GPS receiver and an INS. The data fusion algorithm is designed by the 21st order distributed Kalman Filter which is based on the PVA model with sensor bias states. A fault detection and correction logics are included in the algorithm for bad measurements and sensor faults. The statistical parameters for the states are obtained from Monte Carlo simulations and covariance analysis using test tracking data. The designed filter is verified by using real data both in post processing and real-time processing.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.2
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• pp.177-187
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• 2010

A MTG (Multimode Tracking and Guidance) system is employed to compensate for the limitations of individual seekers such as RF (Radio frequency) or IIR (Imaging Infra-red) and to improve the overall tracking and guidance performance in jamming, clutter, and adverse weather environments. In the MTG system, tracking filter, data association, and data fusion methods are important elements to maximize the effectiveness of precision homing missile guidance. This paper proposes the formulation of a Kalman filter for the estimation of line-of-sight rate from seeker measurements in missiles guided by proportional navigation. Also, we suggest the HPDA (Highest Probability Data Association) and data fusion methods of the MTG system for target tracking in the adverse environments. Mont-Carlo simulation is employed to evaluate the overall tracking performance and guidance accuracy.

• Journal of the Korean Ceramic Society
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• v.49 no.5
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• pp.448-453
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• 2012

Nitrogen-incorporated $SnO_2$ thin films were deposited by rf magnetron sputtering. Comparative structural, electrical and optical studies of thin films deposited by sputtering of the Sn metallic target and sputtering of the $SnO_2$ ceramic target were conducted. The $SnO_2$ thin films deposited by sputtering of the Sn metallic target had a higher electrical conductivity due to a higher carrier concentration than those by sputtering of the $SnO_2$ ceramic target. Structurally the $SnO_2$ thin films deposited by sputtering of the $SnO_2$ ceramic target had a better crystallinity and a larger grain size. This study confirmed that there were distinct and clear differences in electrical, structural, and optical characteristics between $SnO_2$ thin films deposited by reactive sputtering of the Sn metallic target and by direct sputtering of the $SnO_2$ ceramic target.

• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.657-659
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• 1998

In this paper we discuss an algorithm to discriminate a target under track against multiple acoustic counter-measure (ACM) sources, based on sequential testings of multiple hypotheses. The ACM sources are separated from the target under track and generate, while drifting, measurements with false range and Doppler information. The purpose of the ACM is to mislead the target tracking and to help the true target evade a pursuer. The proposed algorithm uses as a test statistic a function of both the sequences of processed waveform signature and the innovation sequences from extended Kalman filters to estimate the target dynamics and the drifting positions of the ACM sources. Numerical experiments on various scenarios show that the proposed algorithm discriminates the target faster with a higher probability of success than the algorithm using only the innovation sequences from extended Kalman filters.

• Nuclear Engineering and Technology
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• v.48 no.3
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• pp.795-798
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• 2016

Transmission X-ray tubes based on carbon nanotube have attracted significant attention recently. In most of these tubes, tungsten is used as the target material. In this article, the well-known simulator Geant4 was used to obtain some of the tungsten target parameters. The optimal thickness for maximum production of usable X-rays when the target is exposed to electron beams of different energies was obtained. The linear variation of optimal thickness of the target for different electron energies was also obtained. The data obtained in this study can be used to design X-ray tubes. A beryllium window was considered for the X-ray tube. The X-ray energy spectra at the moment of production and after passing through the target and window for different electron energies in the 30-110 keV range were also obtained. The results obtained show that with a specific thickness, the target material itself can act as filter, which enables generation of X-rays with a limited energy.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.3
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• pp.445-452
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• 2010

Adequate segmentation of target objects from the background plays an important role for the performance of automatic target recognition(ATR) system. This paper presents a new segmentation algorithm using fuzzy thresholding to extract a target. The proposed algorithm consists of two steps. In the first step, the region of interest(ROI) including the target can be automatically selected by the proposed robust method based on the frame difference of each image sensor. In the second step, fuzzy thresholding with a proposed membership function is performed within the only ROI selected in the first step. The proposed membership function is based on the similarity of intensity and the adjacency of target area on each image. Experimental results applied to real CCD/IR images show a good performance and the proposed algorithm is expected to enhance the performance of ATR system using multi-sensors.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.10
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• pp.486-490
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• 2014

In our country, which imports 97% of the energy consumed, an energy saving policy is required. The price inflation of utility bills is caused by a steep rise in the prices of imported oil. This study aims to solve the difficulties that cause poor environmental conditions for workers in the energy services sector, and especially, to systematize energy consumption reports to manage energy goals by suggesting an example of written energy-saving reports. To this end, this research focuses on energy consumption of target facilities including office spaces in a main building and multi-use facilities of an office building. A system where all employees can participate is structured through the analysis of energy usage in the target buildings.