• Journal of KIISE:Software and Applications
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• v.30 no.7_8
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• pp.773-779
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• 2003

Locating exact position of facial components is a key preprocessing for realizing highly accurate and reliable face recognition schemes. In this paper, we propose a simple but powerful method for detecting isolated facial components such as eyebrows, eyes, and a mouth, which are horizontally oriented and have relatively dark gray levels. The method is based on the shape-resolving locally optimum thresholding that may guarantee isolated detection of each component. We show that pure facial regions can be determined by grouping facial features satisfying simple geometric constraints on unique facial structure. In the test for over 1000 images in the AR -face database, pure facial regions were detected correctly for each face image without wearing glasses. Very few errors occurred in the face images wearing glasses with a thick frame because of the occluded eyebrow -pairs. The proposed scheme may be best suited for the later stage of classification using either the mappings or a template matching, because of its capability of handling rotational and translational variations.

• Spatial Information Research
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• v.20 no.6
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• pp.13-21
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• 2012

In this study, homogeneous regions for regional frequency analysis were identified using rainfall data from 61 observation points in Korea. The used data were gathered from 1980 to 2010. Self organizing map and K-means clustering based on Davies-Bouldin Index were used to make clusters showing similar rainfall patterns and to decide the optimum number of the homogeneous regions. The results from this analysis showed that the 61 observation points can be optimally grouped into 6 geographical clusters. Finally, the 61 observations points grouped into 6 clusters were mapped regionally using Thiessen polygon method.

• Journal of Microbiology and Biotechnology
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• v.8 no.2
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• pp.152-157
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• 1998

To analyze the role of the C and D domains in the cyclization activity of cyclodextrin glucanotransferase (CGTase), two plasmids, pKB1ΔC300 and pKB1ΔD96, were constructed in which DNA regions encoding 100 and 32 amino acids, respectively, from the C and D domains of B. stearothermophilus NO2 CGTase were deleted. The mutated CGTase from the pKBlΔC300 produced much lower amounts of ${\alpha}$-, ${\beta}$-, and $\gamma$-cyclodextrin (CD) than the parental CGTase. However, the mutated CGTase from the pKBlΔD96 showed a similar production pattern of CDs to wild-type CGTase. The production ratios of the ${\alpha}$-, ${\beta}$- and $\gamma$-CDs were not affected by the deletions, when compared to those of parental CGTase. The optimum temperature of the mutated CGTase from the pKBlΔC300 was decreased from $60^{\circ}C$ to $55^{\circ}C$. The optimum pH of the mutated CGTase from the pKB1D96 was shifted from 6.0 to 7.0. The thermostability of the two mutant CGTases were not changed. From these results, it is suggested that the C and D domains are not related to cyclization activity directly because mutant-enzymes deleted C or D domains still possessed their activity. However, they are important for other enzymatic properties such as productivity and pH optimum as a partition of CGTase tertiary structure.

• Journal of Microbiology and Biotechnology
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• v.16 no.3
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• pp.408-413
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• 2006

A strain, P821, with phospholipase D activity was isolated from soil and identified as a Streptomyces species. The phospholipase D enzyme was purified from a culture broth of the isolated strain using ammonium sulfate precipitation and DEAE-Sepharose, phenyl-Sepharose, and Superose 12 HR column chromatographies. The purified enzyme exhibited an optimum temperature and pH of $55^{\circ}C$ and 6.0, respectively, in the hydrolysis of phosphatidylcholine and remained stable up to $60^{\circ}C$ within a pH range of 3.5-8.0. The enzyme also catalyzed a transphosphatidylation reaction to produce phosphatidylserine with phosphatidylcholine and serine substrates. The optimum conditions for the transphosphatidylation were $30^{\circ}C$ and pH 5.0, indicating quite different optimum conditions for the hydrolysis and transphosphatidylation reactions. The gene encoding the enzyme was cloned by Southern hybridization and colony hybridization using a DNA probe designed from the conserved regions of other known phospholipase D enzymes. The resulting amino acid sequence was most similar to that of the PLD enzyme from Streptomyces halstedii (89.5%). Therefore, the enzyme was confirmed to be a phospholipase D with potential use in the production of phosphatidylserine.

• Transactions of the Korean hydrogen and new energy society
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• v.1 no.1
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• pp.15-23
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• 1989

The selective separation of hydrogen from gas mixture containing hydrogen was experimentally studied using $LaNi_5$. The capacity and the rate of hydrogen separation, the purity of recovered hydrogen and the optimum condition of the regeneration of deactivated $LaNi_5$ were investigated. The separation rate and the recovery ratio of hydrogen were slowly decreased with the increase of the number of hydrogen absorption cycle. It was found that this result comes from the deactivation of $LaNi_5$ partly because of the blocking of hydrocarbon compounds in the $LaNi_5$ lattice and partly because of the poisoning of $LaNi_5$ surface by carbon monoxide contained in the gas mixture. The optimum condition for the regeneration of deactivated $LaNi_5$ was obtained by heating in a vacuum to about 637 K. The recovery ratio of hydrogen at the optimum condition was observed to be about 80%. The rates of hydrogen separation were measured in the ${\alpha}$-phase and two phase regions. The rate equations could be expressed as follows ; ${\alpha}$ - phase : $$-\frac{dP{_{H_2}}}{dt}=9.836{\times}10^{-3}(P{_{H_2}}_{-P_{eq}})$$ two phase region : $$-\frac{dP_{H{_2}}}{dt}=1.6909{\times}10^2\exp(-17560/RT)(P{_{H_2}}_{-P_{eq}})$$.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.1
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• pp.17-28
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• 2007

This study was conducted to analyze the optimum heading period according to the recent climatic change for improvement of rice yield and grain quality in the Yeongnam area. We analyzed climatic elements including daily mean air temperature, daily range of air temperature, sunshine hours, and amount of precipitation from 1996 to 2005 in comparison with those of the 1971 to 2000 normal. Daily mean air temperature and amount of precipitation in the recent 10 years increased, but daily range of air temperature and sunshine hours decreased in comparison with the norm. Also, monthly mean air temperature was lowered remarkably in July and August. The monthly amount of precipitation largely increased in August and September. The daily range of air temperature and sunshine hours were greatly decreased from August to October, Possible cultivation periods for rice in the recent 10 years ranged from 171 days in Boughwa to 228 days in Busan and was expanded about $1{\sim}13$ days in comparison with the normal. Optimum heading date by local regions for the maximum climatic yield potential was estimated as July 31 at Bonghwa to September 7 at Busan, Masan, and Tongyeong in the recent 10 years. There was a wide difference in optimum heading date according to local legions of the Yeongnam area. Compared to the normal, optimum heading date in the recent 10 years was delayed about I~8 days in most local regions except Bonghwa, Mungyeong, and Yeongdeok. These results suggested that it is necessary to develop late maturity rice cultivars for producing high yield and quality rice grain due to the recent climatic change. Moreover, it is still more important to select the most suitable cultivation period appropriate to the changed climate of each local region in Yeongnam area.

• Structural Engineering and Mechanics
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• v.47 no.5
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• pp.729-740
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• 2013

This paper addresses the structural design of the front end of Siemens ER24 locomotive body. The steel structure of the frontend is replaced with composite. Optimization of the composite lay-up is performed using Genetic Algorithms. Initially an optimized single design for the entire structure is presented. Then a more refined optimum is developed by considering the separate optimization of 7 separate regions of the structure. Significant savings in the weight of the structure are achieved.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.742-747
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• 2001

A study on the ultrasonic effect for turbulence enhancement is carried out in the horizontal flow field of a coaxial circular pipe. A large transparent acryl tank is made to perform several experiments for the above research. The front flow field from jet exit is divided as 4 measuring regions to observe characteristics of the above flow field according to those with and without ultrasonic. An ultrasonic transducer with 2MHz high frequency is used to give them the ultrasonic forcing. Characteristics such as the velocity distribution, the kinetic energy and the turbulence intensity are visualized, observed, examined and considered at Re No. 2000. In results, it is clarified that the ultrasonic increases the turbulence enhancement. And the optimum and harmonious intensity suited to the power of flow is needed to maximize the turbulence enhancement.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.971-974
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• 2001

Multi-Carrier Spread Spectrum communications has shown the ability of transform domain excision using the wavelet transformation to improve system performance when transmitting signals in the presence of additive white Gaussian noise and interference. In such work, the transforms were implemented using FIR filters and IIR filter. Some well-known classes of sequences, such as Pseudo noise, Walsh, Cold sequences are evaluated with respect to the basic criteria. The main objective is to implement the wavelet transform using IIR filters. This filters are well known to have sharper transition regions leading to better performance. Numerical simulation of multi-carrier spread spectrum communication systems have shown that IIR filters are better in removing the sinusoidal jammer and subsequently yield better BER performance.

• Proceedings of the KSME Conference
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• 2001.06c
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• pp.311-315
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• 2001

In this paper synchronous whirl of bearing is employed as control algorithm of actively controlled hydrodynamic journal bearing to suppress the whirl instability and unbalance response of a rotor-bearing system. Also, the cavitation algorithm implementing the Jakobsson-Floberg-Olsson boundary condition is adopted to predict cavitation regions in the fluid film more accurately than conventional analysis which uses the Reynolds condition. The stability and unbalance responses of a rotor-bearing system are investigated for various control gain and phase difference between the bearing and journal motion. It is shown that the unbalance response of a rotor-bearing system can be greatly improved by synchronous whirl of the bearing, and there is an optimum phase difference, which gives the minimum unbalance response of the system, at given operating condition. It is also found that the speed at onset of instability can be greatly increased by synchronous whirl of the bearing.