• The KIPS Transactions:PartB
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• v.13B no.3 s.106
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• pp.315-322
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• 2006

Ant Colony System(ACS) is easily applicable to the traveling salesman problem(TSP) and it has demonstrated good performance on TSP. Recently, ACS has been emerged as the useful tool for the pattern recognition, feature extraction, and edge detection. The edge detection is wifely utilized in the area of document analysis, character recognition, and face recognition. However, the conventional operator-based edge detection approaches require additional postprocessing steps for the application. In the present study, in order to overcome this shortcoming, we have proposed the new ACS-based edge detection algorithm. The experimental results indicate that this proposed algorithm has the excellent performance in terms of robustness and flexibility.

• Biomolecules & Therapeutics
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• v.8 no.2
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• pp.184-193
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• 2000

To evaluate GC-rhEPO, human erythropoietin produced by recombinant DNA technique, its general pharmacological properties were investigated in experimental animals administering intravenously and in vitro test system. GC-rhEPO at doses of 70,700 and 7,000 IU/kg body weight had no influence on general behavior, spontaneous motor activity, thiopental-inducted sleeping time, writhing syndrome induced by acetic acid, strychnine-induced convulsions, charchoal meal propulsion in mice, and body temperature, gastric juice secretion, urine and electrolyte excretion in rats. In anesthetized rabbits, GC-rhEPO (70, 700 and 7,000 lU/kg, i.v.) did not alter respiratory rate, blood pressure, heat rate. In in vitro experiments, GC-rhEPO did not affect the contractions of the isolated ileum of guinea pigs and the muscle twitchs of isolated neuromuscular junction of the rats. In addition, GC-rhEPO did not affect the blood coagulation time and ADP-induced platelet aggregation in plasma of rabbits. Taken together, these results indicate that GC-rhEPO does not induce any adverse effects in the experimental animals.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.5A
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• pp.593-601
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• 2000

In a multi-bandwidth CDMA system, the performance of multiple order selection combining rake receivers are analyzed according to the spreading bandwidth of the system and the delay spread of the Rayleigh fading channel. The results for various channel environments indicate a tradeoff between total received signal energy and multipath fading immunity. Increasing the occupied bandwidth of the system(wide-bandwidth spreading) gives better performance for small delay spread environments, while gathering more energy(narrow-bandwidth spreading)gives better performance for large delay spread environments. It is shown that the performance difference between low and high order selection combining grows larger as the spreading bandwidth increases. It is also noted that performance degrades by increasing the bandwidth above a certain point and the optimum spreading bandwidth for each channel environment decreases as the delay spread of the channel increases.

• Journal of Applied Biological Chemistry
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• v.60 no.3
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• pp.265-269
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• 2017

Environment-friendly, commercially-available agricultural products were investigated for antimicrobial activity against Sclerotinia sclerotiorum, as a pathogen of sclerotium disease. Then ${\beta}$-thujaplicin from Chamaecyparis obtuse was investigated for antifungal activity against six kinds of pathogenic fungi. It showed a statistically significant (p <0.001) growth inhibition effect on Sclerotinia sclerotiorum as a pathogen of sclerotium disease, Rhizoctonia solani AG-4 as a pathogen of damping off, Phytophthora capsici as a pathogen of phytophthora blight, and Colletotrichum coccodes as a pathogen of anthracnose at a concentration of 50 ppm and on Stemphylium solani as a pathogen of spotting disease and Alternaria alternata as a pathogen of black mold at a concentration of 100 ppm. In conclusion, these results indicate that it may be possible to develop environment-friendly agricultural products using ${\beta}$-thujaplicin compounds.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.194-194
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• 2011

The effects of argon neutral beam (NB) energy on the amorphous carbon (a-C) films were investigated, while the a-C films were deposited by neutral particle beam assisted sputtering (NBAS) system. The energy of neutral particle beam can be controlled by reflector bias voltage directly as a unique operating parameter in this system. The deposition characteristics of the films investigated of Raman spectra, UV-visible spectroscopy, electrical conductivity, stress measurement system, and ellipsometer indicate the properties of amorphous carbon films can be manipulated by only NB energy (or reflector bias voltage) without changing any other process parameters. We report the effect of reflector bias voltage in the range from 0 to -1KV. By the increase of the reflector bias voltage, the amount of cross-linked sp2 clusters as well as the sp3 bonding in the a-C film coated by the NBAS system can be increased effectively and the composition of carbon thin films can be changed from nano-crystalline graphite phase to amorphous carbon phase.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.4
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• pp.1203-1222
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• 2012

To provide active notification and enhance drivers'awareness of their surroundings, a vision-based collision warning system that detects and monitors surrounding vehicles is proposed in this paper. The main objective is to prevent possible vehicle collisions by monitoring the status of surrounding vehicles, including the distance to the other vehicles in front, behind, to the left and to the right sides. In addition, the proposed system collects and integrates this information to provide advisory warnings to drivers. To offer the correct notification, an algorithm based on features of edge and morphology to detect vehicles is also presented. The proposed system has been implemented in embedded systems and evaluated on real roads in various lighting and weather conditions. The experimental results indicate that the vehicle detection ratios were higher than 97% in the daytime, and appropriate for real road applications.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.6
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• pp.1914-1925
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• 2014

Inter-symbol interference (ISI) problem is inevitable when the guard interval (GI) is shorter than the delay spread (DS) for an orthogonal frequency division multiplexing (OFDM) system. Iterative techniques have been proposed to overcome such a problem. However, most of existing algorithms are not efficient for an OFDM system with a small GI working under the channel with a large DS. Especially in the case of the DS spans a longer time than the half of the OFDM symbol duration. On the other hand, conventional algorithms, which can reduce the effects of the severe ISI, often employ several impractical assumptions to support the conclusions. In this paper, we present a robust decision feedback equalizer (DFE) for the OFDM system to overcome the severe ISI problem. The proposed DFE removes the ISI in a same manner as the residual inter-symbol interference cancellation (RISIC) algorithm. However, the inter-carrier interference (ICI) is reduced via cyclicity removal instead of the cyclicity restoration used in the conventional algorithms. The link-level simulation (LLS) results indicate that our proposed DFE scheme can dramatically improve the BER performance when the DS spans longer than the half of ODFM symbol duration.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.47
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• pp.57-68
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• 1998

Work environments have been changed with the advent of new technologies, such as computer technology. However, human cognitive limits can't pace up with the change of work environment. Designing human-computer system requires knowledge and evaluation of the human cognitive processes which control information flow workload. Futhermore, under limited reaction time and/or urgent situation, human operator may the work stress, work error and resultant deleterious work environment. This paper evaluate the visual factors of major information processing factors(information density, amount of information, operational speed of speed)on operator performance of supervisory control under urgent(limited reaction time)environments which require deleterious work condition. To describe the work performance int the urgent work situations with time stress and dynamic event occurrence, a new concept of information density was introduced. For a series of experiments performed for this study, three independent variables(information amount, system proceeding speed, information density) were evaluated using five dependent variables. The result of statistical analyses indicate that the amount of information affected on all of five dependent measure. Number of failure and number of secondary task score were influenced by both amount of information and operational speed of system. However reaction time of secondary task were affected by both amount of information and information density. As a result, the deleterious factors for the performances seemed to be a scanning time to supervise each control panel. Consequently, a new display panel was suggest to reduce operator work load for scanning task showing better operator performance.

• Journal of the Optical Society of Korea
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• v.19 no.5
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• pp.437-443
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• 2015

In this paper, we analyze the performance of the all-optical multihop radio over a free space optical (RoFSO) communication system with amplify-and-forward (AF) relays under varying weather conditions. The proposed channel model considers the propagation loss, attenuation and atmospheric fading modeled by the Gamma-Gamma (GG) distribution. Both the amplified spontaneous emission (ASE) noise in the all-optical relays and the background noise projected onto receiver apertures have been considered in the analysis. The lower bound analytical expressions for the end-to-end bit error rate (BER) and outage probability are derived for the multihop system employing the all-optical relays with the full channel state information (CSI). Meanwhile, the exact results for BER and outage probability are obtained via Monte Carlo simulation. Results indicate the performance of the proposed system will be improved by the multihop transmission technology. For a fixed number of relays, the BER and outage probability will be increased with the deterioration of the weather conditions.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.3
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• pp.231-242
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• 2011

This study examines influences of a daylight dimming control system on the variation of indoor illuminance and lighting energy savings in a small office space. Field measurements and a series of computation were performed for typical types of sky conditions in summer. Results indicate that the daylight illuminance under clear and partly-cloudy sky were close to the target illuminance during a majority of time due to a higher ratio of window to wall. However, the target illuminance was not kept successfully due to the variation of photosensor signals which were strongly influenced by desktop illuminance. The system with partially-shielded conditions succeeded to keep target illuminance under clear sky conditions. The system failed under overcast sky conditions since the electric light output from fixtures caused excessive signals to photosensors due to insufficient daylight on a desktop. Unshielded and fully-shielded conditions were not recommended for effective controls of the systems. The influence of lighting fixtures on photosensors should be minimized to achieve successful lighting controls by daylight dimming systems.