• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.4
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• pp.321-325
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• 2004

It is quite difficult to create an unbiased and stable random bit stream, as required for statistical randomness, when using a random generator with only a hardware component. In this paper, we studied to reduce the statistical property of the biased bit stream in the output of a real random number generator. The proposed scheme is enhanced the randomness of output bitstream, these test items are used by FIPS 140-1.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.6161-6176
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• 2018

Pseudorandom numbers are useful in cryptographic operations for using as nonce, initial vector, secret key, etc. Security of the cryptosystem relies on the secret key parameters, so a good pseudorandom number is needed. In this paper, we have proposed a new approach for generation of pseudorandom number. This method uses the three dimensional combinational puzzle Rubik Cube for generation of random numbers. The number of possible combinations of the cube approximates to 43 quintillion. The large possible combination of the cube increases the complexity of brute force attack on the generator. The generator uses cryptographic hash function. Chaotic map is being employed for increasing random behavior. The pseudorandom sequence generated can be used for cryptographic applications. The generated sequences are tested for randomness using NIST Statistical Test Suite and other testing methods. The result of the tests and analysis proves that the generated sequences are random.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.10
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• pp.507-511
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• 2005

We have derived the linear complexity of a binary sequence generated by a Feedback with Carry Shift Regiater(FCSR) under the following condition: q is a power of a prime such that $q=r^e,\;(e{\geq}2)$ and r=2p+1, where both r and p are 2-prime. Also, a summation generator creates sequence from addition with carry of LFSR(Linear Feedback Shift Register) sequences. Similarly, it is possible to generate keystream by bitwise exclusive-oring on two FCSR sequences. In this paper, we described the cryptographic properties of a sequence generated by the FCSRs in view of the linear complexity.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.226.2-226.2
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• 2005

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.7C
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• pp.915-920
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• 2004

In this paper, we propose the new polyphase sequence with the best nonperiodic autocorrelation property in the viewpoint of the merit factors, which are important criteria for a nonperiodic autocorrelation property. We propose the general implementation of a polyphase sequence generator over an integer residue ring by using a linear feedback shift register(LFSR), in addition, we analyze the linear complexities of polyphase sequences based on the proposed implementation method.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.61-66
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• 2004

In this paper an effort is made to develop an innovative spatial arrangement concept pertaining to ship building industry. The spatial scheduling is the problem that concentrates on effective planning of available space and arrangements of blocks and in a priority manner. In order to create an effective spatial scheduling. a database providing the priority has to be available to make the erection sequence. Such a system works hand in hand with erection sequence generator program The erection sequence program works on the conventional network analysis method which uses a typical parent-children idea for the calculation of the ENT(possible earliest network start time) and LNT(possible latest network start time). This program works in a cyclic manner taking turns by calculating the ENT in upward trace and LNT on the return trace thereby generating the entire erection sequence diagram for the requisite problem The generated database serves as an input data for spatial scheduling problem. When the system works it takes into consideration the entire system based on heuristic concepts as mentioned. There system uses the spatial aspects such as the available area of the P. E area and plan area of the corresponding blocks and its priority of erection from the erection sequence generator program develops the spatial scheduling arrangement. In this paper using all these concepts an innovative spatial schedule development system developed.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.43 no.5 s.311
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• pp.44-59
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• 2006

This paper describes the efficient implementation of DNA sequence generate system with genetic algorithm for reducing computation time of NACST. The proposed processor is based on genetic algerian with fitness functions which would suit the point of reference for generated sequences. In order to implement efficient hardware structure, we used the pipelined structure. In addition our design was applied the parallelism to achieve even better simulation time than the sequence generator system which is designed on software. In this paper, our hardware is implemented on the FPGA board with xc2v6000 devices. Through experiment, the proposed hardware achieves 467 times speed-up over software on a PC and sequence generate performance of hardware is same with software.

• Journal of Electrical Engineering and Technology
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• v.8 no.5
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• pp.1029-1039
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• 2013

To avoid undesirable disconnection of healthy wind generators (WGs) or a wind power plant, a WG protection relay should discriminate among faults, so that it can operate instantaneously for WG, connected feeder or connection bus faults, it can operate after a delay for inter-tie or grid faults, and it can avoid operating for parallel WG or adjacent feeder faults. A WG protection relay based on the positive- and negative-sequence fault components is proposed in the paper. At stage 1, the proposed relay uses the magnitude of the positive-sequence component in the fault current to distinguish faults requiring non-operation response from those requiring instantaneous or delayed operation responses. At stage 2, the fault type is first determined using the relationships between the positive- and negative-sequence fault components. Then, the relay differentiates between instantaneous operation and delayed operation based on the magnitude of the positive-sequence fault component. Various fault scenarios involving changes in position and type of fault and faulted phases are used to verify the performance of the relay. This paper concludes by implementing the relay on a hardware platform based on a digital signal processor. Results indicate that the relay can successfully distinguish the need for instantaneous, delayed, or non-operation.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.581-584
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• 2003

It is important to know phase offsets of PN (Pseudo Noise) sequences in spread spectrum communications since the acquisition is equivalent to make a phase offset between a receiving PN sequence and a PN sequence of local PN generator be identical. In this paper, a phase offset enumeration method for PN sequences with error detection, and its application to the synchronization are proposed. The phase offset enumeration far an n-tuple PN sequence and its error detection are performed when one period of the sequence is received. Once the phase offset of the receiving sequence is calculated, we can easily accomplish the synchronization by initializing shift registers of a local PN generator according to the phase offset value. The mean acquisition time of the proposed synchronization method is derived analytically, and we see that the method acquires very fast acquisition in the high SNR (Signal-to- Noise Ratio) environment.

• ETRI Journal
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• v.28 no.2
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• pp.250-252
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• 2006

In this letter, a discrete state, discrete time chaotic pseudo random number generator (CPRNG) is presented for stream ciphering of text, audio, or image data. The CPRNG is treated as a finite state machine, and its state is modulated according to the input bit sequence of the signal to be encrypted. The modulated state sequence obtained can be transmitted as a spread spectrum or encrypted data.