• Smart Structures and Systems
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• v.23 no.1
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• pp.71-79
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• 2019

In general, it may be advantageous to measure the pressure pulsation near a valve to detect a valve defect in a linear compressor. However, the acceleration signals are more advantageous for rapid classification in a mass-production line. This paper deals with the performance improvement of fault classification using only the compressor-shell acceleration signal based on the relation between the refrigerant pressure pulsation and the shell acceleration of the compressor. A transfer function was estimated experimentally to take into account the signal noise ratio between the pressure pulsation of the refrigerant in the suction pipe and the shell acceleration. The shell acceleration signal of the compressor was modified using this transfer function to improve the defect classification performance. The defect classification of the modified signal was evaluated in the acceleration signal in the frequency domain using Fisher's discriminant ratio (FDR). The defect classification method was validated by experimental data. By using the method presented, the classification of valve defects can be performed rapidly and efficiently during mass production.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.1038-1039
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• 2005

• The Journal of Engineering Geology
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• v.14 no.2
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• pp.169-177
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• 2004

The permeation movements of groundwater recharge and contaminate materials receive a eat effect due to porosity and effective porosity of porous media which is composing underground consisted of saturation and unsaturated states. This study developed Frequency Domain Reflectometry(FDR) system and measurement sensor, and then carried out the laboratory experiments to measure effective porosity for unsaturated porous media. Also, I suggested dielectric mixing models(DMMs) which can calculate the effective porosity from relation of measured dielectric constants. In the experimental results the extent range of effective porosity of standard sand and river sand which are unsaturated soil sample were measured in about 65∼85 % for porosity. In relation of effective porosity and porosity, especially, effective porosity confirmed that displays decreasing a little tendency as porosity increases. This is because unsaturated soil did not reach in saturation enough by air of very small amount that exist in pore between soil particles.

• The Journal of Engineering Geology
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• v.14 no.2
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• pp.179-187
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• 2004

This study conducted a laboratory work to determine the change of dielectric constant of saturated soil porous media, which is injecting EML to use Frequency Domain Reflectometry(FDR) system and length 7cm-length measurement sensor. It is purpose of study that estimate a movement path through pore of soil for an ethanol mixing liquid(EML) which have the same specific gravity of water at $20{\;}^{\circ}C$, and determine to a dielectric measuring range for the measurement sensor. As an outflow point of saturated soil column upper part recedes from an EML inject point in EML diffusion test, the diffusion extent of EML through pore of saturated soil was expanded. And results of ail EML flow experiment were measured the change of dielectric constant at all measurement sensors which are placed to constant interval at the same travel time for saturated soil column. Therefore, the displace process of water that exist in pore of saturated soil by EML injection is enough available and confirm together mobility through pores.

• Journal of Microbiology and Biotechnology
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• v.29 no.1
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• pp.44-54
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• 2019

Geldanamycin and its derivatives, inhibitors of heat shock protein 90, are considered potent anticancer drugs, although their biosynthetic pathways have not yet been fully elucidated. The key step of conversion of 4,5-dihydrogeldanamycin to geldanamycin was expected to catalyze by a P450 monooxygenase, Gel16. The adequate bioconversions by cytochrome P450 mostly rely upon its interaction with redox partners. Several ferredoxin and ferredoxin reductases are available in the genome of certain organisms, but only a few suitable partners can operate in full efficiency. In this study, we have expressed cytochrome P450 gel16 in Escherichia coli and performed an in vitro assay using 4,5-dihydrogeldanamycin as a substrate. We demonstrated that the in silico method can be applicable for the efficient mining of convenient endogenous redox partners (9 ferredoxins and 6 ferredoxin reductases) against CYP Gel16 from Streptomyces hygroscopicus. The distances for ligand FDX4-FDR6 were found to be $9.384{\AA}$. Similarly, the binding energy between Gel16-FDX4 and FDX4-FDR6 were -611.88 kcal/mol and -834.48 kcal/mol, respectively, suggesting the lowest distance and binding energy rather than other redox partners. These findings suggest that the best redox partners of Gel16 could be NADPH ${\rightarrow}$ FDR6 ${\rightarrow}$ FDX4 ${\rightarrow}$ Gel16.

• The Korean Journal of Air & Space Law and Policy
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• v.23 no.2
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• pp.137-172
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• 2008

The earliest safety data programs, the FDR and CVR, were electronic reporting systems that generate data "automatically." The FDR program, originally instituted in 1958, had no publicly available restrictions for protections against sanctions by the FAA or an airline, although there are agreements and union contracts forbidding the use of FDR data for FAA enforcement actions. This FDR program still has the least formalized protections. With the advent of the CVR program in 1966, the precursor to the current FAR 91.25 was already in place, having been promulgated in 1964. It stated that the FAA would not use CVR data for enforcement actions. In 1982, Congress began restricting the disclosure of the CVR tape and transcripts. Congress added further clarification of the availability of discovery in civil litigation in 1994. Thus, the CVR data have more definitive protections in place than do FDR data. The ASRS was the first non-automatic reporting system; and built into its original design in 1975 was a promise of limited protection from enforcement sanctions. That promise was further codified in an FAR in 1979. As with the CVR, from its inception, the ASRS had some protections built in for the person who might have had a safety problem. However, the program did not (and to this day does not) explicitly deal with issues of use by airlines, litigants, or the public media, although it appears that airlines will either take a non-punitive stance if an ASRS report is filed, or the airline may ignore the fact that it has been filed at all. The FAA worked with several U.S. airlines in the early 1990s on developing ASAP programs, and the FAA issued an Advisory Circular about the program in 1997. From its inception, the ASAP program contained some FAA enforcement protections and company discipline protections, although some protection against litigation disclosure and public disclosure was not added until 2003, when FAA Order 8000.82 was promulgated, placing the program under the protections of FAR 193, which had been added in 2001. The FOQA program, when it was first instituted through a demonstration program in 1995, did not contain protections against sanctions. Now, however, the FAA cannot take enforcement action based on FOQA safety data, and an airline is limited to "corrective action" under the program. Union contracts can exclude FOQA from the realm of disciplinary action, although airline practice may be for airlines to require retraining if there is no contract in place forbidding it. The data is protected against disclosure for litigation and public media purposes by FAA Order 8000.81, issued in 2003, which placed FOQA under the protections of FAR 193. The figure on the next page shows when each program began, and when each statute, regulation, or order became effective for that program.

• The Journal of Engineering Geology
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• v.14 no.3 s.40
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• pp.301-311
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• 2004

This study is suggested a new dielectric tracer test method to understand geological structure of porous media and groundwater flow to use the dielectric constant which is one of electrical special quality of various geological materials. To measure their parameters, tracer material is made an ethanol mixing liquid(EML) having a same specific gravity of water. Also, soil materials are prepared a dielectric tracer test using the FDR system that could measure dielectric constant for saturated standard sand and river sand layers which have different initial porosity. To compare with their results, we discussed with the concentration variation of saline water having a saline concentration $3\%$ which is general tracer material by using the electro multi-meter system in the laboratory or field test. In two tracer experiment results, EML tracer test could confirm definitely EML concentration variation from each saturated soil layer as standard and river sands. However, tracer test of saline water $3\%$ concentration could not confirm permeating movement of water by degree of salinity change because these are settled at lower part column in a whole column area continuously. These causes are that specific gravity of saline water is heavier than water. That is, it could know that deposition of saline water is composed of lower part of soil column continuously independently of the direction of water into saturated soil material.

• The KIPS Transactions:PartC
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• v.18C no.5
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• pp.331-338
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• 2011

The RFID system includes a section of wireless communication between the readers and the tags. Because of its vulnerability in terms of security, this part is always targeted by attackers and causes various security problems including the leakage of secret and the invasion of privacy. In response to these problems, various protocols have been proposed, but because many of them have been hardly implementable they have been limited to theoretical description and theorem proving without the accurate verification of their safety. Thus, this study tested whether the protocol proposed by Kenji et al. satisfies security requirements, and identified its vulnerabilities such as the exposure of IDs and messages. In addition, we proposed an improved RFID security protocol that reduced the number of public keys and random numbers. As one of its main characteristics, the proposed protocol was designed to avoid unnecessary calculations and to remove vulnerabilities in terms of security. In order to develop and verify a safe protocol, we tested the protocol using Casper and FDR(Failure Divergence Refinements) and confirmed that the proposed protocol is safe in terms of security. Furthermore, the academic contributions of this study are summarized as follows. First, this study tested the safety of a security protocol through model checking, going beyond theorem proving. Second, this study suggested a more effective method for protocol development through verification using FDR.

• The Journal of Engineering Geology
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• v.14 no.4 s.41
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• pp.361-369
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• 2004

The authors designed a new technique to measure dielectric constant of a soil media by Frequency Domain Reflectometry (FDR) system and its measurement sensor probe with different length such as 7m, 10cm and 15cm for estimating the variations of dielectric constant. Measurement of dielectric constant of soil material is possible to measure an interference wave generated by between incidence wave and reflection wave which are detected to electro-magnetic wave through the directional coupler at the high frequency range,0.1 to 1.7GHz, by FDR system. The obtained experimental results verified that the technique is very promising for non-destructive and continuous soil volumetric water content measurement monitoring in a laboratory. The relationship between the soil volumetric water content and the dielectric constant of soil media (standard sand) was expressed by a single regression ewe independent of soil texture at a small experimental error. Also the derived regression curve coincided well with that obtained by Topp curve.

• The Journal of Engineering Geology
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• v.13 no.4
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• pp.405-418
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• 2003

Measurements of volumetric water content and saturation of porous media are very important factors in understanding the physical characteristics of soil, groundwater recharge by rainfall, pollutant movement, and slope failure. To measure such physical parameters, a permittivity method using electromagnetic wave is applied and use is made of the special permittivity response of understand to water and ethanol. In particular, the estimation is required because permittivity is influenced by the nature of the underground environment. In this study, we carried out experiments on the relative dependency of soil density, temperature and salinity of standard sand and granitic weathered soil using FDR-V system (Frequency domain reflectometry with vector network analyzer) within a frequency range of 1 - 18 GHz. The results of the study showed that the dielectric constants of standard sand and granitic weathered soil increased with increased volumetric water content of soil. However, the dependency of soil density was found to be a little low. Changes of dielectric constant with temperature appeared definitely in the real part of 1 GHz. That is, the dielectric constant of real part at 1 GHz of water and standard sand increased with the rise of temperature. However, ethanol showed decreased tendency. The study also showed that dielectric constant increased with increase in salinity at imaginary part of 1 GHz. It could be concluded from this study FDR-V system can adequately measure the physical properties of soil and the degree of salinity concentration of porous media within 1 GHz frequency range using dielectric constant.