• Journal of Microbiology and Biotechnology
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• v.18 no.3
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• pp.410-416
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• 2008

The gene SfXyn10, which encodes a protease-resistant xylanase, was isolated using colony PCR screening from a genomic library of a feather-degrading bacterial strain Streptomyces fradiae var. k11. The full-length gene consists of 1,437bp and encodes 479 amino acids, which includes 41 residues of a putative signal peptide at its N terminus. The amino acid sequence shares the highest similarity (80%) to the endo-1,4-${\beta}$-xylanase from Streptomyces coelicolor A3, which belongs to the glycoside hydrolase family 10. The gene fragment encoding the mature xylanase was expressed in Escherichia coli BL21 (DE3). The recombinant protein was purified to homogeneity by acetone precipitation and anion-exchange chromatography, and subsequently characterized. The optimal pH and temperature for the purified recombinant enzyme were 7.8 and $60^{\circ}C$, respectively. The enzyme showed stability over a pH range of 4.0-10.0. The kinetic values on oat spelt xylan and birchwood xylan substrates were also determined. The enzyme activity was enhanced by $Fe^{2+}$ and strongly inhibited by $Hg^{2+}$ and SDS. The enzyme also showed resistance to neutral and alkaline proteases. Therefore, these characteristics suggest that SfXyn10 could be an important candidate for protease-resistant mechanistic research and has potential applications in the food industry, cotton scouring, and improving animal nutrition.

• Journal of Microbiology and Biotechnology
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• v.18 no.3
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• pp.404-409
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• 2008

The brown-rot basidiomycete Fomitopsis palustris is known to degrade crystalline cellulose (Avicel) and produce three major cellulases, exoglucanases, endoglucanases, and ${\beta}$-glucosidases. A gene encoding endoglucanase, designated as cel12, was cloned from total RNA prepared from F. palustris grown at the expense of Avicel. The gene encoding Cel12 has an open reading frame of 732 bp, encoding a putative protein of 244 amino acid residues with a putative signal peptide residing at the first 18 amino acid residues of the N-terminus of the protein. Sequence analysis of Cel12 identified three consensus regions, which are highly conserved among fungal cellulases belonging to GH family 12. However, a cellulose-binding domain was not found in Cel12, like other GH family 12 fungal cellulases. Northern blot analysis showed a dramatic increase of cel12 mRNA levels in F. palustris cells cultivated on Avicel from the early to late stages of growth and the maintenance of a high level of expression in the late stage, suggesting that Cel12 takes a significant part in endoglucanase activity throughout the growth of F. palustris. Adventitious expression of cel12 in the yeast Pichia pastoris successfully produced the recombinant protein that exhibited endoglucanase activity with carboxymethyl cellulose, but not with crystalline cellulose, suggesting that the enzyme is not a processive endoglucanase unlike two other endoglucanases previously identified in F. palustris.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.7A
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• pp.724-729
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• 2007

In this paper, we consider a joint optimization of transmitter and receiver in additive cyclostationary noise with zero forcing criterion. We assume that the period of the cyclostationary noise is the same as the inverse of the symbol transmission rate and that the noise has a positive-definite autocorrelation function. The data sequence is modeled as a wide-sense stationary colored random process and the channel is modeled as a linear time-invariant system with a frequency selective impulse response. Under these assumptions and a constraint on the average power of the transmitted signal, we derive the optimum transmitter and receiver waveforms that jointly minimizes the mean square error with no intersymbol interference. The simulation results show that the proposed system has a better BER performance than the systems with receiver only optimization and the systems with no transmitter and receiver optimization.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.4
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• pp.56-64
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• 2006

Generally, Permanent Magnet Brushless DC Motor(PM BLDC) is necessary the Hall-IC to detect the rotor position. But it will take place the operation standstill of motor or error of rotor position detection according to the circumference temperature, humidity, or limited surroundings. This paper propose the algorithm of rotor position detection only using one or two Hall-IC. Therefore we can estimate information of the others phase in sequence through a rotor instead of using three Hall-IC at 3 phase motor. This paper identify the same characteristics, performance and function of protection circuit by the proposed algorithm with the 3 phase PM BLDC motor in comparison with general method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.10
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• pp.829-841
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• 1990

On assuming that the transmission speed of the original information is the fifth-order transmission speed of the Korea digital multiplex hierarchy (564.992Mb/s), this paper proposes a new structure of the transmission line frame at the terminal repeater system, in order to not only maintain and conserve 565Mb/s optical fiber transmission system but also make the B.S.I. of digital communication network for the optical transmission. And the structure uses the mBIZ transmission line code, which is considered the optimal transmission line code of conventional transmission line codes. System hardware of the transmission line frame structure proposed in this paper is consisted by a method of pulse stuffing after converting the speed of the original information signal sequence at the terminal repeater system for 565Mb/s optical transmission. As a result of this, we can prevent the optical transmission system from a domino phenomenon, the phenomenon of the continuous error multiplication of systems by the transmission error, and suppress timing jitter and the identical consecutive digit number. And also we can improve SNR of the optical transmission system about 2dB because of raising total BER at the optical terminal system up to 10.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.1
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• pp.29-35
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• 2006

The third generation mobile communications system requiring the reliable multimedia data transmission has provided with the reliable voice, data and video services over the variable propagation environment. However the broadband wireless multiple access technologies cause Inter Symbol Interference(ISI) or Multiple Access Interference(MAI) to degrade the performance of CDMA(Code Division Multiple Access) system. Constant Modulus Algorithm which is frequently used as the adaptive blind equalizers to remove the interfering signal has ill-convergence phenomenon without proper initialization. In this paper, new blind equalization method based on conventional CMA is proposed to improve the channel efficiency, and through computer simulation this is tested over the time varying fading environment of mobile communication system. consequently, new blind equalization method into concatenated Kalman filter with CMA is verified better than conventional CMA through adopting minimum mean square errors and eye-pattern obtained from algorithm are compared.

• Smart Structures and Systems
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• v.9 no.3
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• pp.287-301
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• 2012

It is well known that overloaded vehicles may cause severe damages to bridges, and how to estimate and evaluate the status of the overloaded vehicles passing through bridges become a challenging problem. Therefore, based on the monitored strain data from a structural health monitoring system (SHM) installed on a bridge, a method is recommended to identify and analyze the probability of overloaded vehicles. Overloaded vehicle loads can cause abnormity in the monitored strains, though the abnormal strains may be small in a concrete continuous rigid frame bridge. Firstly, the abnormal strains are identified from the abundant strains in time sequence by taking the advantage of wavelet transform in abnormal signal identification; secondly, the abnormal strains induced by heavy vehicles are picked up by the comparison between the identified abnormal strains and the strain threshold gotten by finite element analysis of the normal heavy vehicle; finally, according to the determined abnormal strains induced by overloaded vehicles, the statistics of the overloaded vehicles passing through the bridge are summarized and the whole probability of the overloaded vehicles is analyzed. The research shows the feasibility of using the monitored strains from a long-term SHM to identify the information of overloaded vehicles passing through a bridge, which can help the traffic department to master the heavy truck information and do the damage analysis of bridges further.

• Journal of Digital Convergence
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• v.11 no.12
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• pp.393-399
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• 2013

Recently, the quantity and type of data that is being processed in cloud environment are varied. A method for easy access in different network in a heterogeneous environment of big data stored in the device is required. This paper propose security management method for smoothly access to big data in other network environment conjunction with attribute information between big data and user. The proposed method has a high level of safety even if user-generated random bit signal is modulated. The proposed method is sufficient to deliver any number of bits the user to share information used to secure recognition. Also, the security awareness information bit sequence generated by a third party to avoid unnecessary exposure value by passing a hash chain of the user anonymity is to be guaranteed to receive.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1480-1484
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• 2003

This paper presents the design and development of network for housing estate security system. The system can cover up to 961 houses which can be up to 1,200 meters long transfer rate of 9,600 bps. This system uses checking and warning the abnormal situation. More over this system has ability to control switch on/off the electrical equipment in the house via AC line control system. The system consists of 4 parts. The first part is a security system of each house using MCS-51 microcontroller as a central processing unit scan 32 sensors and control 8 appliances and send alarm. The MCS-51 microcontroller received control signal via telephone used DTMF circuit. The second part is distributed two levels master/slave network implementing after RS-485 serial communication standard. The protocol its base on the OSI (Open Systems Interconnection) 7 layers protocol model design focus on speed, reliability and security of data that is transferred. The network security using encrypt by DES algorithm, message sequence, time stamp checking and authentication system when user to access and when connect new device to this system. Flow control in system is Poll/Select and Stop-and-Wait method. The third part is central server that using microcomputer which its main function are storing event data into database and can check history event. The final part is internet system which users can access their own homes via the Internet. This web service is based on a combination of SOAP, HTTP and TCP/IP protocols. Messages are exchanged using XML format [6]. In order to save the number of IP address, the system uses 1 IP address for the whole village in which all homes and appliance in this village are addressed using internal identification numbers. This proposed system gives the data transfer accuracy over 99.8% and maximum polling time is 1,120 ms.

• Journal of Digital Convergence
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• v.10 no.9
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• pp.363-368
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• 2012

The Cluster-based routing protocol is consumed the energy consumption efficiently, but there are many isolated nodes while clustering, so these are impeding energy efficiency. Hop-by-hop based routing protocol is suitable large-scaled network or dynamic environment. However, with the periodic flooding signal and rapid energy loss of near sink nodes, the network life time become shorter. In this paper, We propose the hybrid routing protocol that combine the cluster based routing method for energy efficiency of nodes and hop-by-hop method for re-joining the isolated nodes and load balance of nodes in the near cluster using fibonacci sequence. Based on the analysis, it is proved that the hybrid routing protocol provided higher energy efficiency and less the isolated nodes than previous methods.