• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.6
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• pp.52-60
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• 2003

In aviation navigation using GPS, requirements on availability and integrity must be absolutely satisfied. Current study on accomplishing this integrity includes RAIM(Receiver Autonomous Integrity Monitoring), monitoring integrity internaIly in GPS receiver itself. Parity space technique as one of RAIM techniques has shown the advantages in fault detection and isolation due to each use of its magnitude and direction under the assumption of one fault. ln case of multiple fault, as biases in errors interact decreasing the effect of multiple fault in parity space, the exact fault detection and identification(FDI) may be difficult to be conducted. This paper focuses on FDI study on two faults and explains why parity space techniques applied on single fault is not adequate to the application of multiple fault case and shows that extended parity space technique may improve the performance of RAIM on two faults.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.2
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• pp.169-179
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• 2010

Satisfying the same probability of loss of control and essentially two fail operative performance with a triplex computer architecture requires a lot of modification of the conventional redundancy management design techniques, previously employed in quadruplex digital flight control computer. T-50 FCS for triplex redundancy management design applied an advanced digital flight control architecture with an I/O controller which is functionally independent of the digital computer to achieve the same reliability and special failure analysis and isolation schemes for fail operational goals with a triplex configuration. The analysis results indicated that the triplex flight control system is to satisfy the safety requirement utilizing the advanced flight control techniques and the system performance of the implemented flight control system was verified by failure mode effect test.

• Journal of Microbiology and Biotechnology
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• v.22 no.9
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• pp.1185-1192
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• 2012

This study investigated the hydrocarbonoclastic microbial community present on weathered crude oil and their ability to degrade weathered oil in seawater obtained from the Gulf St. Vincent (SA, Australia). Examination of the native seawater communities capable of utilizing hydrocarbon as the sole carbon source identified a maximum recovery of just $6.6{\times}10^1\;CFU/ml$, with these values dramatically increased in the weathered oil, reaching $4.1{\times}10^4\;CFU/ml$. The weathered oil (dominated by > $C_{30}$ fractions; $750,000{\pm}150,000mg/l$) was subject to an 8 week laboratory-based degradation microcosm study. By day 56, the natural inoculums degraded the soluble hydrocarbons (initial concentrations $3,400{\pm}700mg/l$ and $1,700{\pm}340mg/l$ for the control and seawater, respectively) to below detectable levels, and biodegradation of the residual oil reached 62% ($254,000{\pm}40,000mg/l$) and 66% ($285,000{\pm}45,000mg/l$) in the control and seawater sources, respectively. In addition, the residual oil gas chromatogram profiles changed with the presence of short and intermediate hydrocarbon chains. 16S rDNA DGGE sequence analysis revealed species affiliated with the genera Roseobacter, Alteromonas, Yeosuana aromativorans, and Pseudomonas, renowned oil-degrading organisms previously thought to be associated with the environment where the oil contaminated rather than also being present in the contaminating oil. This study highlights the importance of microbiological techniques for isolation and characterisation, coupled with molecular techniques for identification, in understanding the role and function of native oil communities.

• Journal of Microbiology
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• v.44 no.4
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• pp.383-395
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• 2006

Four different Trichoderma strains, T. harzianum CECT 2413, T. asperellum T53, T. atroviride T11 and T. longibrachiatum T52, which represent three of the four sections contained in this genus, were transformed by two different techniques: a protocol based on the isolation of protoplasts and a protocol based on Agrobacterium-mediated transformation. Both methods were set up using hygromycin B or phleomycin resistance as the selection markers. Using these techniques, we obtained phenotypically stable transformants of these four different strains. The highest transformation efficiencies were obtained with the T. longibrachiatum T52 strain: 65-70 $transformants/{\mu}g$ DNA when transformed with the plasmid pAN7-1 (hygromycin B resistance) and 280 $transformants/l0^7$ spores when the Agrobacterium-mediated transformation was performed with the plasmid pUR5750 (hygromycin B resistance). Overall, the genetic analysis of the transform ants showed that some of the strains integrated and maintained the transforming DNA in their genome throughout the entire transformation and selection process. In other cases, the integrated DNA was lost.

• Journal of Korean Neurosurgical Society
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• v.39 no.3
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• pp.215-220
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• 2006

Objective : Tyrosine kinase inhibitors may be useful in the management of cerebral vasospasm. It has not yet been reported whether L-type $Ca^{2+}$ channels playa role in tyrosine kinase inhibitors-induced vascular relaxation of cerebral artery. This study was undertaken to clarify the role of L-type $Ca^{2+}$ channels in tyrosine kinase inhibitors-induced vascular relaxation, and to investigate the effect of tyrosine kinase inhibitors on L-type $Ca^{2+}$ channels currents in freshly isolated smooth muscle cells from rat basilar artery. Methods : The isolation of rat basilar smooth muscle cells was performed by special techniques. The whole cell currents were recorded by whole cell patch clamp technique in freshly isolated smooth muscle cells from rat basilar artery. Results : Patch clamp studies revealed a whole-cell current which resembles the L-type $Ca^{2+}$ current reported by others. The amplitude of this current was decreased by nimodipine and increased by Bay K 8644. Genistein[n=5], tyrphostin A-23[n=3]. A-25[n=6] $30{\mu}M$ reduced the amplitude of the L -type $Ca^{2+}$ channel current in whole cell mode. In contrast, diadzein $30{\mu}M$ [n=3]. inactive analogue of genistein, did not decrease the amplitude of the L-type $Ca^{2+}$ channels current. Conclusion : These results suggest that tyrosine kinase inhibitors such as genistein, tyrphostin A-23, A-25 may relax cerebral vessel through decreasing level of intracellular calcium, [$Ca^{2+}$]i, by inhibition of L-type $Ca^{2+}$ channel.

• Journal of Sensor Science and Technology
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• v.22 no.1
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• pp.28-37
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• 2013

This paper presents a fault-tolerant control technique for wind turbine systems with sensor and actuator faults. The control objective is to maximize power production and minimize turbine loads by calculating a desired pitch angle within their limits. Any fault with a sensor and actuator can cause significant error in the pitch position of the corresponding blade. This problem may result in insufficient torque such that the power reference cannot be achieved. In this paper, a fault-tolerant control technique using a robust dynamic inversion observer and control allocation is employed to achieve successful pitch control despite these faults in the sensor and actuator. The observer based detection method is used to detect and isolate sensor faults by checking whether errors are larger than threshold values. In addition, the control allocation technique is adopted to tolerate actuator fault. Control allocation is one of the most commonly used fault-tolerant control techniques, especially for over-actuated systems. Further, the control allocation method can be used to achieve the power reference even in the event of blade actuator fault by redistributing the lost torque due to erroneous pitch position into non-faulty blade actuators. The effectiveness of the proposed method is demonstrated through simulations with a benchmark model of the wind turbine.

• Korean Journal of Computational Design and Engineering
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• v.17 no.2
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• pp.97-110
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• 2012

High performance sensors and modern data logging technology with real-time telemetry facilitate system fault diagnosis in a very precise manner. Fault detection, isolation and identification in fault diagnosis systems are typical steps to analyze the root cause of failures. This systematic failure analysis provides not only useful clues to rectify the abnormal behaviors of a system, but also key information to redesign the current system for retrofit. The main barriers to effective failure analysis are: (i) the gathered data (event) logs are too large in general, and further (ii) they usually contain noise and redundant data that make precise analysis difficult. This paper therefore applies suitable pre-processing techniques to data reduction and feature extraction, and then converts the reduced data log into a new format of event sequence information. Finally the event sequence information is decoded to investigate the correlation between specific event patterns and various system faults. The efficiency of the developed pre-filtering procedure is examined with a terminal box data log of a marine diesel engine.

• Steel and Composite Structures
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• v.35 no.5
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• pp.687-699
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• 2020

This paper focus on the buckling restrained braces (BRBs) with new casing members (CMs). Seven BRBs with CMs consisting of precast concrete modules (PCMs) were tested to investigate the effects of CMs on the cyclic performance of BRBs. The PCMs consisted of plain and reinforced concrete casted into wooden or steel molds than they were located on the core plate (CP) via bolts. There were 14 or 18 PCMs on the CP for each BRBs. The technique of the PCMs for the CM provides that the BRBs can be constructed inside the steel or reinforced concrete (RC) structures. In this way, their applications may be rapid and practical during the application of the retrofitting. The test results indicated that the cyclic performance of the BRBs was dominated by the connection strength and confinement of the PCMs. The BRBs with PCMs wrapped with fiber reinforced polymers (FRPs) sustained stable hysteretic performance up to a CP strain of 2.0 %. This indicates that the new designed BRBs with PCMs were found to be acceptable in terms of cyclic performance. Furthermore, the connection details, isolation materials and their application techniques have been also investigated for the improved BRB design in this study.

• Journal of muscle and joint health
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• v.13 no.1
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• pp.53-66
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• 2006

Aims. In order to analyze the concept of stigma, so to develop a valid instrument to measure stigma. Methods. First, a concept analysis was conducted with the aim of clarifying the state of the science of discipline-specific conceptualizations of stigma. The criterion-based method of concept analysis as described by Morse and colleagues was used (Morse et al., 1996; Morse, 2000). This analytic process enabled the assessment of the scientific maturity of the concept of stigma. The interdisciplinary concept of stigma was found to be immature. Based on this level of maturity it was determined that in order to advance the concept of stigma toward gloater maturity. techniques of concept development using the literature as data were applied. In this process, questions were 'asked of the data' (in this case, the selected disciplinary literatures) to identify the conceptual components of stigma. Results. The inquiry into the concept of stigma led to the development of an expanded interdisciplinary conceptual definition by merging the most coherent commonalties from each discipline. And the conceptual components of stigma were identified. The antecedent factors of stigma were "apart from social identity". The attributes of stigma were "devaluing, labeling, negative stereotypes, discrimination". The consequences of stigma were "social rejection, social isolation, deficiency of social support, low social status".

• Natural Product Sciences
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• v.16 no.4
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• pp.217-222
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• 2010

A phytochemical investigation of the ethanolic extract of Erythrina caffra flowers from an Egyptian origin yielded three C-flavonoidal glycosides; 5,7,4'-trihydroxyflavone-8-C-$\beta$-D-glucopyranoside (vitexin) (1), 5,7,4'-trihydroxyflavone-6-C-$\beta$-D-glucopyranosyl-(1 $\rightarrow$ 2)-$\beta$-D-glucopyranoside (isovitexin-2"-$\beta$-D-glucopyranoside) (2), 5, 7, 4'-trihydroxyflavone-6, 8-di-C-$\beta$-D-glucopyranoside (vicenin-2) (3) and one O-flavonoidal glycoside; kaempferol-3-O-$\beta$-D.glucopyranosyl) (1 $\rightarrow$ 2)-$\beta$-D-glucopyranoside (4). The structures of the isolated compounds (1 - 4) were elucidated using different spectral techniques (UV, 1D and 2D NMR and HRESIMS). This is the first report for the isolation of flavonoidal glycosides from Erythrina caffra. The antibacterial, antifungal, antimalarial, and antileishmanial activities of the isolates were evaluated. In addition, the cytotoxic activity of the ethanolic extract and the main fractions were tested using brine shrimp bioassay.