• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.535-543
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• 2002

Although the generic implementation of aqueous two-phase systems (ATPS) processes for the recovery of biological products has been exploited for several years, this has not resulted in a wide adoption of the technique. The main reasons involve the poor understanding of the mechanism governing phase formation and the behavior of solute partitioning in ATPS processes, the cost of phase forming polymers, and the necessary extended time to optimize the technique. In this review paper, some of the practical disadvantages attributed to ATPS are addressed. The practical approach exploited to design ATPS processes, the application to achieve process integration, the extended use for the recovery of high-value products, and the recent development of new low-cost ATPS, are discussed. It is proposed that the trend of the practical application of ATPS processes for the recovery of biological products will involve the purification of new high-value bioparticulate products with medical applications. Such a trend will give new impetus to the technique, and will draw attention from industries needing to develop new, and improve existing, commercial processes.

• The Journal of Society for e-Business Studies
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• v.7 no.1
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• pp.167-186
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• 2002

The encryption of a file on a PC before saving can maintain security of the file. However, if the key for the encrypted file is lost or damaged, the encrypted file can not be decrypted, resulting in serious economical loss to the user or the user group. In order to minimize the economical loss a secure and reliable key recovery technology is required. Presented in this paper is the development and evaluation of PKRS (PC based Key Recovery System) which supports encryption and decryption of file and recovery of the encrypted file in emergency. The encapsulating method, which attaches key recovery information to encrypted file, is applied to the PKRS. In addition, the PKRS is developed and evaluated according to the requirements of Requirements for Key Recovery Products proposed by NIST and requirements of Common Criteria 2.0 to prove the safety and reliability of the information security system. This system is applicable to a PC and can be further extended to internet or intranet environment information system where in encryption and recovery of file is possible.

• Korean Chemical Engineering Research
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• v.55 no.5
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• pp.652-659
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• 2017

In the present research, in order to predict activity coefficient of inorganic ions in electrolyte solution of a petroleum system, we studied 13 components in the electrolyte solution, including $H_2O$, $CO_2$ (aq), $H^+$, $Na^+$, $Ba^{2+}$, $Ca^{2+}$, $Sr^{2+}$, $Mg^{2+}$, $SO_4$, $CO_3$, $OH^-$, $Cl^-$, and $HCO_3$. To predict the activity coefficient of the components of the petroleum system (a solid/liquid equilibrium system), activity coefficient model of Extended UNIQUAC was studied, along with its adjustable parameters optimized based on a genetic algorithm. The total calculated error associated with optimizing the adjustable parameters of Extended UNIQUAC model considering the 13 components under study at three temperature levels (298.15, 323.15, and 373.15 K) using the genetic algorithm is found to be 0.07.

• Journal of the Korea Society of Computer and Information
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• v.25 no.10
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• pp.77-86
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• 2020

In this paper, we propose a technique for blockchain service replication and recovery using kubernetes(BR2K) that robustly executes blockchain services based on replication and supports systematic recovery in case of the service failure. Blockchain services are being developed and applied in various fields such as administration, finance, and medical systems based on the features of blockchain, such as decentralization, high security, and data integrity. In such areas where service continuity is important, it is necessary to provide robustness for execution of blockchain services, and a recovery plan for service failure is also required. To this end, BR2K provides an execution replication technique that systematically supports the sustainable execution of blockchain application services. Also, it introduces a robust container registry based on the blockchain service registry, systematically supporting the recovery of service failures by using it. In addition, Truffle, a blockchain service development framework, is extended to utilize the Kubernetes container management tool, and BR2K provides a technique for rapidly deploying blockchain services using the extended framwork.

• The Transactions of the Korea Information Processing Society
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• v.7 no.6
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• pp.1874-1885
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• 2000

When a receiver of ciphertext message can not decrypt a message because he has lost his private-key, the private-key of receiver and session-key of the message should be recovered. In this paper, we developed an Encapsulation based Key Recovery System (EKRS). EKRS is a new key encapsulation based key recovery system which is characterized by secretly choice of KRA, randomized target keys. n-way recovery type, and useful for commercial key recovery. EKRS is formally specified by a pictorial model, an Extended Cryptographic Timed Petri Net (ECTPN). Secure information flow and reachability of a session-key are verified by using reachability graph of ECTPN. EKRS, executing over a Public Key Infrastructure, can be used as a security solution in Web based applications such as CALS, EC an EDI.

• Transactions of Materials Processing
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• v.9 no.2
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• pp.193-202
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• 2000

The influence of rolling draughts on the formation of through-thickness textures in aluminum 5000X sheet was investigated by X-ray texture measurements and microstructure observations. In order to intensify the deformation inhomogeneities, cold rolling was performed without lubrication. Applying a large draught gave rise to the formation of the shear texture at the surface, whereas a normal plane strain testure formed at the surface after deformation with a small draught. The orientation density along the $\beta$-fiber orientations which developed in the center layer of the rolled specimen was also dependent on the strain gradients in a roll gap. Upon annealing, the deformed substructure of sample surfaces was transformed into a fine grained recrystallized microsturcture through extended recovery reaction. However, coarse grains developed after the discontinuous recrystallization which gave rise to the development of the Cube-texture.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.5A
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• pp.634-640
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• 2000

This paper proposes a new extended decision directed-decision estimated phase recovery algorithm based on maximum likelihood parameter estimation for OQPSK. In this scheme, comparing conventional one, the data dependent noise of phase recovery loop is reduced by inserting filter with 2 taps to in-phase and quadrature-phase channel respectively before phase detector. The proposed scheme is compared to conventionalscheme and OQPSK in aspect to BER(Bit Error Rate) and phase error according to the roll-off factor of baseband filter, the output back-offs of nonlinear satellite channel, and loop bandwidth.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.7B
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• pp.650-659
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• 2004

Domestic wireless network environment is changing rapidly while adapting to meet service requirements of users and growth of market. As a result, reliable data transmission using TCP is also expected to increase. Since TCP assumes that it is used in wired networt TCP suffers significant performance degradation over wireless network where packet losses are not always result of network congestion. Especially RTO imposes a great performance degradation of TCP. In this paper, we propose DAC$^{＋}$ and EFR in order to prevent performance degradation by quickly detecting and recovering loss without RTO during fast recovery. Compared with TCP NewReno, proposed scheme shows improvements in steady-state in terms of higher fast recovery Probability and reduced response time.

• Journal of KIISE:Software and Applications
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• v.29 no.11
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• pp.767-774
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• 2002

Conventional research on image restoration has focused on restoring degraded images resulting from image formation, storage and communication, mainly in the signal processing field. Related research on recovering original image information of caption regions includes a method using BMA(block matching algorithm). The method has problem with frequent incorrect matching and propagating the errors by incorrect matching. Moreover, it is impossible to recover the frames between two scene changes when scene changes occur more than twice. In this paper, we propose a method for recovering original images using EBMA(Extended Block Matching Algorithm) and a region compensation method. To use it in original image recovery, the method extracts a priori knowledge such as information about scene changes, camera motion and caption regions. The method decides the direction of recovery using the extracted caption information(the start and end frames of a caption) and scene change information. According to the direction of recovery, the recovery is performed in units of character components using EBMA and the region compensation method. Experimental results show that EBMA results in good recovery regardless of the speed of moving object and complexity of background in video. The region compensation method recovered original images successfully, when there is no information about the original image to refer to.

• Korean Journal of Veterinary Research
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• v.24 no.2
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• pp.245-266
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• 1984

As a fundamental study to increase the reproductive efficiency in cattle, highly motile sperm were separated and collected from raw semen, extended semen and frozen semen by different methods using various concentrations of bovine serum albumin or Tyrode's solution. Various characteristics and light microscopic and electron-microscopic morphology of sperm separated by different methods were compared. The results obtained were as follows; 1. The sperm separated from raw semen using bovine serum albumin showed significantly high value in motility, motile sperm count, percent of normal sperm and progressive motility, as compared with control sperm and revealed the highest sperm recovery rate when separated with 6% bovine serum albumin. 2. The sperm motility, percent of normal sperm and progressive motility of the highly motile sperm frozen after being separated from raw semen with bovine serum albumin, showed significantly high value than those of a control sperm and especially found the highest value when separated with 20% bovine serum albumin. 3. Light-microscopic percent of abnormality was significantly low in the prefrozen and postfrozen highly motile sperm separated with bovine serum albumin, as compared with control sperm. 4. Electron-microscopic finding of the highly motile sperm separated with bovine serum albumin showed low percent of deformity in the dilatation and vesiculation of cell membrane, in dilatation and density loss of acrosome than in those of control sperm. 5. It was impossible to separate the highly motile sperm from frozen semen with bovine serum albumin, but it was possible with Tyrode's solution. 6. Recovery rate of highly motile sperm from raw semen extended semen and frozen semen was the highest when the sperm pellet stood in Tyrde's solution for 80 minutes. 7. The highly motile sperm separated from raw semen, extended semen and frozen semen with Tyrode's solution showed significantly high value in motility, progressive motility and percent of normal sperm, as compared with control sperm. 8. Highly motile sperm, when separated from raw semen, extended semen and frozen semen with Tyrode's solution, showed significantly low percent of microscopic abnormality as compared with control sperm.