• Korean Journal of Food Science and Technology
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• v.5 no.3
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• pp.169-173
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• 1973

Secondary amines and nitrites in various daily foods have been known as the precursors of potent carcinogenic nitroso compound produced in the human stomach when they were ingested simultaneouly in high concentration. In this report, the amounts and distribution of secondary amines and nitrites in Korean daily foods, kim-chi, fishes, fish eggs, sausages, canned fish foods and fish sauces (salted fish) were studied.Nitrite contents were low in most subjected foods except in sausages. Secondary amines showed low contents in kim-chi, fishes, but high in fish sauces, fish eggs and canned fish foods. The result of this study suggested that the possible formation of carcinogenic nitrosamines during manufacturing, storage and cooking of all Korean foods should be studied.

• Journal of Animal Environmental Science
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• v.13 no.1
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• pp.13-20
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• 2007

Sawdust biofiltration is an emerging bio-technology for control of ammonia emissions including compost odors from composting of biological wastes. Although sawdust is widely used as a medium for bulking agent in composting system and for microbial attachment in biofiltration systems, the performance of agitated bed composting and sawdust biofiltration are not well established. A pilot-scale composting of hog manure amended with sawdust and sawdust biofiltration systems for practical operation were investigated using aerated and agitated rectangular reactor with compost turner and sawdust biofilter operated under controlled conditions, each with a working capacity of approximately $40m^3\;and\;4.5m^3$ respectively. These were used to investigate the effect of compost temperature, seed germination rate and the C/N ratio of the compost on ammonia emissions, compost maturity and sawdust biofiltration performance. Temperature profiles showed that the material in three runs had been reached to temperature of 55 to $65^{\circ}C$ and above. The ammonia concentration in the exhaust gas of the sawdust biofilter media was below the maximum average value as 45 ppm. Seed germination rate levels of final compost was maintained from 70 to 93% and EC values of the finished compost varied between 2.8 and 4.8 ds/m, providing adequate conditions for plant growth.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.2
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• pp.118-126
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• 2004

Recombinant E.coli ACV 1003 (recA::lacZ) releasing ${\beta}$-galactosidase by a SOS regulon system, when exposed to DNA-damaging compounds, have been used to effectively monitor endocrine disruptors. Low enzyme activity of less than 10 units/mL, corresponding to a $\mu\textrm{g}$/L(ppb) range of an endocrine disruptor (tributyl tin, bisphenol A. etc.), can be rapidly determined, not by a conventional time-consuming and tedious enzyme assay, but by an alternative interferometric biosensor. Heavily boron-doped porous silicon for application as an interferometer, was fabricated by etching to form a Fabry-Perot fringe pattern, which caused a change in the refractive index of the medium including ${\beta}$-galactosidase. In order to enhance the immobilization of the porous silicon surface, a calyx crown derivative (ProLinker A) was applied, instead of a conventional biomolecular affinity method using biotin. This resulted in a denser linked formation. The change in the effective optical thickness versus ${\beta}$-galactosidase activity, showed a linear increase up to a concentration of 150 unit ${\beta}$-galactosidase/mL, unlike the sigmoidal increase pattern observed with the biotin.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.2
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• pp.241-249
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• 2008

In this study, lateral vibration analysis has been conducted on a propulsion and lift shafting system for an air cushion vehicle using ANSYS code. The shafting system is totally flexible multi-elements system including air propeller, aluminum alloy of lift fan and thin walled shaft with flexible coupling. The analysis included the lateral natural frequencies, mode shapes and harmonic analysis of the shafting system taking into account three-dimensional models for propulsion and lifting shaft system. In case of ACV the yawing and pitching rate of craft will be quite high. During yawing and pitching of craft significant gyroscopic moment will be applied to the shafting and will generate high amplitude of lateral vibration. So, such a shafting system has very intricate lateral vibrating characteristics and natural frequencies of shafting must be avoided in the range of operating revolution. The control of lateral vibration is included in this study.

• BMB Reports
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• v.36 no.4
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• pp.379-386
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• 2003

A mutant herpes simplex virus 1, mtHSV, was constructed by inserting the E. coli beta-galactosidase gene into the loci of icp34.5, the apoptosis-inhibiting gene of HSV. The mtHSV replicated in and lysed U251 (human glioma cells), EJ (human bladder cells), and S-180 (mice sarcoma cells), but not Wish (human amnion cells) cells. With its intact tk (thymidine kinase) gene, mtHSV exhibited susceptibility to acyclovir (ACV), which provided an approach to control viral replication. An in vivo test with mtHSV was conducted in immune-competent mice bearing sarcoma S-180 tumors, which were treated with a single intratumoral injection of mtHSV or PBS. Tumor dimensions then were measured at serial time points, and the tumor volumes were calculated. Sarcoma growth was significantly inhibited with prolonged time and reduced tumor volume. There was microscopic evidence of necrosis of tumors in treated mice, whereas no damage was found in other organs. Immunohistochemical staining revealed that virus replication was exclusively confined to the treated tumor cells. HSV-1 DNA was detected in tumors, but not in the other organs by a polymerase chain reaction analysis. From these experiments, we concluded that mtHSV should be a safe and promising oncolytic agent for cancer treatment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.387-392
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• 2006

In the environment where AGVs(Automated Guided Vehicles) operate concurrently in limited space, collisions. deadlocks, and livelocks which have negative effect on the productivity of AGVs occure more frequently. The accelerated motion of an AGV is also the factor that make the AGV routing more difficult because the accelerated motion makes it difficult to estimate the vehicle's exact travel time. In this study, we propose methods of avoiding collisions, deadlocks, and livelocks using OAR(Occupancy Area Reservation) table, and selecting best route by estimating the travel time of an AGV in accelerated motion. A time-driven simulation validated the effectiveness of the proposed methods.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.928-942
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• 2020

The pressure responsiveness property of a skirt-cushion system, which is closely related to the overall performance of Air Cushion Vehicles (ACVs), has always been the difficulty and challenging problem involving cushion aerodynamics and flexible skirt dynamics. Based on a widely used bag and finger skirt-cushion system, the pressure responsiveness properties are investigated numerically. The physical process and mechanism are analyzed and a numerical method for evaluating the pressure responsiveness property is proposed. A cushion-skirt information communication platform is also presented for interchanging the force and the skirt configuration between cushion aerodynamics and flexible skirt dynamics. The pressure responsiveness of a typical skirt-cushion system is calculated and the results demonstrate that the pressure responsiveness property helps alleviate the influence of the cushion height changing on the overall performance of ACVs. Finally, the influences of skirt geometrical and cushion aerodynamic parameters on the pressure responsiveness properties are discussed systematically, giving insight into the design of skirt-cushion systems.

• Journal of Microbiology and Biotechnology
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• v.16 no.12
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• pp.1968-1976
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• 2006

Recombinant E. coli ACV 1003 (recA:: lacZ) was used to measure low concentrations of DNA-damaging chemicals, which produce $\beta$-galactosidase via an SOS regulon system. Very low $\beta$-galactosidase activities of less than 0.01 unit/ml, $\beta$-galactosidase produced through an SOS response corresponding to the 10 ng/ml (ppb) of DNA damaging chemicals in the environment, can be rapidly determined by using an alternative interferometric biosensor with optically flat thin films of porous silicon rather than by the conventional time-consuming Miller's enzyme assay as well as the ELISA method. fu order to enhance the sensitivity in the interferometry, it needs to obtain more uniform distribution and higher biolinking efficiency, whereas interferometric sensing is rapid, cheap, and advantageous in high throughput by using a multiple-well-type chip. In this study, pore size adjusted to 60 nm for the target enzyme $\beta$-galactosidase to be bound on both walls of a Si pore and a calyx crown derivative was apllied as a more efficient biolinker. Furthermore, anti-$\beta$-galactosidase was previously functionalized with the biolinker for the target $\beta$-galactosidase to be specifically bound. When anti-$\beta$-galactosidase was bound to the calyx-crown derivative-linked surface, the effective optical thickness was found to be three times as high as that obtained without using anti-$\beta$-galactosidase. The resolution obtained was very similar to that afforded by the time-consuming ELISA method; however, the reproducibility was still unsatisfactory, below 1 unit $\beta$-galactosidase/ml, owing to the microscopic non-uniform distribution of the pores in the etched silicon surface.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.2
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• pp.48-59
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• 1992

In this paper, the effects of a skirt deformation on the responses of an Air Cushion Vehicle in waves are investigated. The air in the bag and in the plenum chamber is assumed to be compressible and to have a uniform instantaneous pressure distribution in each volume. The free surface deformation is determined in the framework of linear potential theory by replacing the cushion pressure with the pressure patch moving uniformly with an oscillating strength. And the bag-finger skirt is assumed to be deformed due to the pressure disturbance while its surface area remained constant. The restoring force and moment due to the deformation of bag-finger skirt from the equilibrium shape is included in the equations of hearse and pitch motions. The numerical results of motion responses due to various ratios of the bag and cushion pressure or bag-to-finger depth ratios are shown.

• Convergence Security Journal
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• v.8 no.2
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• pp.63-70
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• 2008

In order not to make the malwares be easily analyzed, the hackers apply various anti-reversing and obfuscation techniques to the malwares. However, as the more anti-revering techniques are applied to the malwares the more abnormal characteristics in the PE file's header which are not shown in the normal PE file, could be observed. In this letter, a new malware detection technique is proposed based on this observation. For the malware detection, we define the Characteristics Vector(CV) which can represent the characteristics of a PE file's header. In the learning phase, we calculate the average CV(ACV) of malwares(ACVM) and normal files(ACVN). To detect the malwares we calculate the 2 Weighted Euclidean Distances(WEDs) from a file's CV to ACVs and they are used to decide whether the file is a malware or not. The proposed technique is very fast and detection rate is fairly high, so it could be applied to the network based attack detection and prevention devices. Moreover, this technique is could be used to detect the unknown malwares because it does not utilize a signature but the malware's characteristics.