• Korean Journal of Microbiology
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• v.10 no.4
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• pp.155-166
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• 1972

With respect to a bacterium isolated some of the similarities and differences previously indicated between Thiobacillus thiooxidans and Thiobacillus concretivorus wee confirmed and the bacteria also provided considerable diferences compared to the two species in some repects. Severe precipitation of sulfur occurred in colonies and in liquid media of the organism isolated. The organism isolated utilized nitrate and asparagine as well as ammonium sulfate as a sole nitrogen source and grew well without being nearly inhibited by citrate and malate. This organism also showed the resistance to heats and external physical stimulations. Owing to some characters decribed above and the reports proposed, the organism isolated could be concluded to be Thiobacillus concretivorus and it was suggested that Thiobacillus concretivorus might be an apparently different species from Thiobacillus thiooxidans.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.11a
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• pp.21-26
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• 1996

The identification of radioactive source in a medium with a limited number of external detectors is introduced as an inverse radiation transport problem. This kind of inverse problem is usually ill-posed and severely under-determined, however, its applications are very useful in manu fields including medical diagnosis and nondestructive assay of nuclear materials. Therefore, it is desired to develop efficient and robust solution algorithms. As an approach to solving inverse problems, an artificial neural network is proposed. We develop a modified version of the conventional Hopfield neural network and demonstrate its efficiency and robustness.

• BMB Reports
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• v.41 no.3
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• pp.248-253
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• 2008

Stresses and nutritional starvation are two main external signals for the induction of sex pheromones in the fission yeast Schizosaccharomyces pombe. In an attempt to identify the components involved in transduction of starvation signals, we screened 135 temperature-sensitive (ts) mutants and isolated 6 mutants that induced the pheromone even in the presence of a nitrogen source. These mutants exhibited two distict induction phenotypes: pheromone induction at restrictive but not at permissive temperatures; and pheromone induction at both permissive and restrictive temperatures. The times required for the maximum pheromone induction at the restrictive temperature differed slightly in each mutant. In addition to the pheromone induction phenotype, the ts243 and ts304 mutants exhibited cell-division-cycle defects. The ts304 mutant cells showed an abnormal cytoplasmic DAPI staining pattern. The nucleolus of this mutant seemed to be fragmented, a phenomenon which is typically observed in aged yeast cells. The result of our genetic analysis indicated that the pheromone induction mutants belonged to 6 separate complementation groups. We designated these mutants pws1 to pws6.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.71-74
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• 2003

The signal processing algorithm for a PSD(Position Sensitive Detector) using amplitude modulation/demodulation is addressed in this paper. Dark currents and external noises such as daylight and fluorescent lights are eliminated by using amplitude modulation/demodulation and a low pass filter. The proposed amplitude modulation/demodulation method for a PSD sensor is compared with pulse amplitude modulation method. The proposed amplitude modulation is proved to be more accurate and robust than PAM method by analysis and experiments. Multiple measurements using one PSD sensor by amplitude modulation/demodulation is also addressed. The Power variation of light source is compensated by normalization process using a divider.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.7
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• pp.931-936
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• 2013

In this paper, the temperature distribution of 400kVA hybrid transformer is predicted by using CFD analysis. The copper loss and iron loss which are heat source are calculated by using Joule heat and Bertotti's equation respectively. To improve the convergence of the numerical calculation and to reduce the computation time, the 1/4 model is used and the incompressible air model is used for external air. To verify analysis result, the temperature rise test and no-load test of the transformer are performed. The experiment result obtained by using thermo-graphic camera is similar to the numerical result of the CFD analysis.

• Journal of the Korean Society of Safety
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• v.29 no.6
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• pp.55-61
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• 2014

The autoignition temperature (AIT) of a material is the lowest temperature at which the substance will spontaneously ignite in the absence of an external ignition source such as a spark or flame. The AIT may be used as combustion property to specify operating, storage, and materials handling procedures for processs safety. This study measured the AITs of n-Propanol+n-Decane system from ignition delay time(time lag) by using ASTM E659 apparatus. The AITs of n-Propanol and n-Decane which constituted binary system were $435^{\circ}C$ and $212^{\circ}C$, respectively. The experimental AITs of n-Propanol+n-Decane system were a good agreement with the calculated AITs by the proposed equations with a few A.A.D(average absolute deviation).

• The Transactions of the Korea Information Processing Society
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• v.6 no.11S
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• pp.3278-3288
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• 1999

This paper proposes a security platform, called SCAP(Security platform for CORBA based APplication), to cope with potential threats in a distributed object system. SCAP supports CORBA security specification announced by OMG. SCAP is comprised of four functional blocks, which co-work with ORB to provide security services: Authentication Block, Association Block, Access Control Block, and Security Information Management Block. It is designed to support Common Secure Interoperability Functionality Level 2, which is useful for large-scale intra-, or inter-network based applications. Actual security services, which are dependent on supporting security technology, will be provided as external security service for replace ability. Implementation issues such as how to simulate an interceptor mechanism using a commercial ORB product without source code, and how to extend Current object required for security services are also described. At the end of the paper, the SCAP applied to the web environment is described to show its practical utilization.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2154_2155
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• 2009

Development of renewable energy is promoted to achieve sustainability. So researchers are seeking and developing a new, clean, safe and renewable energy. However, solar energy is an extreme intermittent and inconstant energy source. In order to improve the photovoltaic system efficiency and utilize the solar energy more fully, and the DC power vary with the irradiation, it is necessary to study the characteristics of P-V according to the external factors. This paper presents the analysis of characteristics of P-V according to the irradiation. The results show that the DC power of the photovoltaic system are increased along with the increasing values of irradiation.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2148_2149
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• 2009

Development of renewable energy is promoted to achieve sustainability. So researchers are seeking and developing a new, clean, safe and renewable energy. However, solar energy is an extreme intermittent and inconstant energy source. In order to improve the photovoltaic system efficiency and utilize the solar energy more fully, and the DC power vary with module temperature, it is necessary to study the characteristics of photovoltaic P-V according to the external factors. This paper presents the analysis of characteristics of photovoltaic P-V according to the module temperature. The results show that it seems that when the module temperature increases, the DC power increases. But actually, because when the irradiation increases, the DC power increases, the result of the relationship between DC power and the module temperature of solar cell will be effects by the increasing irradiation.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2150_2151
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• 2009

Solar, as an ideal renewable energy, has inexhaustible, clean and safe characteristics. However, solar energy is an extreme intermittent and inconstant energy source. In order to improve the photovoltaic system efficiency and utilize the solar energy more fully, and the DC current vary with module temperature, it is necessary to study the characteristics of photovoltaic I-V according to the external factors. This paper presents the analysis of characteristics of photovoltaic I-V according to the module temperature. The results show that it seems that when the module temperature increases, the DC current increases. But actually, because when the irradiation increases, the DC current increases, the result of the relationship between DC current and the module temperature of solar cell will be effects by the increasing irradiation.