• Geomechanics and Engineering
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• v.15 no.6
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• pp.1207-1217
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• 2018

Geomechanics parameters are critical to numerical simulation, stability analysis, design and construction of geotechnical engineering. Due to the limitations of laboratory and in situ experiments, back analysis is widely used in geomechancis and geotechnical engineering. In this study, a hybrid back analysis method, that coupling numerical simulation, response surface (RS) and relevance vector machine (RVM), was proposed and applied to identify geomechanics parameters from hydraulic fracturing. RVM was adapted to approximate complex functional relationships between geomechanics parameters and borehole pressure through coupling with response surface method and numerical method. Artificial bee colony (ABC) algorithm was used to search the geomechanics parameters as optimal method in back analysis. The proposed method was verified by a numerical example. Based on the geomechanics parameters identified by hybrid back analysis, the computed borehole pressure agreed closely with the monitored borehole pressure. It showed that RVM presented well the relationship between geomechanics parameters and borehole pressure, and the proposed method can characterized the geomechanics parameters reasonably. Further, the parameters of hybrid back analysis were analyzed and discussed. It showed that the hybrid back analysis is feasible, effective, robust and has a good global searching performance. The proposed method provides a significant way to identify geomechanics parameters from hydraulic fracturing.

• Reproductive and Developmental Biology
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• v.34 no.3
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• pp.257-262
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• 2010

The purpose of this study is to establish a basic culture system enabling in vitro culture of chicken blastodermal cells and to test the feasibility of retrovirus-mediated gene transfer to the cultured cells. The blastodermal cells were isolated from freshly laid eggs of stage X and cultured with or without STO feeder layer cells. Stem cell-like morphology was maintained after multiple passages and RT-PCR analysis proved expression of several stem cell specific genes. Immunocytochemical analysis using antibodies of anti-EMA-1 and anti-SSEA-1 also showed the feature of stem cells. Infection of the cultured blastodermal cells with LNCGW retrovirus vector resulted in successful transfer of foreign genes. The results of this study may be useful in establishing stem cell-mediated transgenic chicken production.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.4
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• pp.171-178
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• 1997

Vehicle interior noise has become increasingly important in this recent years. The noise of a vehicle is one of the important problems in a vehicle design. The interior noise is caused by various vibration sources of vehicle compartment. The booming noise of a vehicle can be significantly affected by vibrations transmitted from engine excitation forces to the vehicle body. Specially, we are interested in the state of transmission paths such as engine mounts to reduce noise in a vehicle compartment. In this paper, we have been calculated the contribution of each transmission path such as engine mounts to interior noise. To identify contribution of each input sources and transmission paths to output, the effectiveness of each input component to output is calculated. Sensitivity analysis is carried out for investigation of contribution to output due to input variations. With the simulation of magnitude and phase change of inputs using vector synthesis diagram, the trends of synthesized output vector are obtained. As a result, we suggested sensitivity analysis of vector synthesis as a technique of prediction and control for noise in a vehicle compartment.

• Journal of Astronomy and Space Sciences
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• v.29 no.3
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• pp.287-293
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• 2012

Satellite operating agencies are constantly monitoring conjunctions between satellites and space objects. Two line element (TLE) data, published by the Joint Space Operations Center of the United States Strategic Command, are available as raw data for a preliminary analysis of initial conjunction with a space object without any orbital information. However, there exist several sorts of uncertainties in the TLE data. In this paper, we suggest and analyze a method for estimating the uncertainties in the TLE data through mean, standard deviation of state vector residuals and covariance matrix. Also the estimation results are compared with actual results of orbit determination to validate the estimation method. Characteristics of the state vector residuals depending on the orbital elements are examined by applying the analysis to several satellites in various orbits. Main source of difference between the covariance matrices are also analyzed by comparing the matrices. Particularly, for the Korea Multi-Purpose Satellite-2, we examine the characteristics of the residual variation of state vector and covariance matrix depending on the orbital elements. It is confirmed that a realistic consideration on the space situation of space objects is possible using information from the analysis of mean, standard deviation of the state vector residuals of TLE and covariance matrix.

• Journal of Positioning, Navigation, and Timing
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• v.9 no.3
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• pp.207-214
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• 2020

In this paper, we implement linear-quadratic-Gaussian based vector tracking loop (LQG-VTL) instead of conventional extended Kalman filter based vector tracking loop (EKF-VTL). The LQG-VTL can improve the performance compared to the EKF-VTL by generating optimal control input at a specific performance index. Performance analysis is conducted through two factors, frequency thermal noise and frequency dynamic stress error, which determine total frequency tracking error. We derive the thermal noise and the dynamic stress error formula in the LQG-VTL. From frequency tracking error analysis, we can determine control gain matrix in the LQG controller and show that the frequency tracking error of the LQG-VTL is lower than that of the EKF-VTL in all C/N0 ranges. The simulation results show that the LQG-VTL improves performance by 30% in Doppler tracking, so the LQG-VTL can extend pre-integration time longer and track weaker signals than the EKF-VTL. Therefore, the LQG-VTL algorithm is more robust than the EKF-VTL in weak signal environments.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.12
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• pp.1254-1261
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• 2007

The structure has several types of noise and booming noise of a vehicle is usually caused by the vibration of the vehicle's body transmitted from the engine through the mounting system. Vector synthesis analysis is performed to predict the booming noise when the characteristic of the engine mounting system is changed., i.e., when magnitudes and phases of vibratory forces after the mounts are altered. To use this method effectively, the concept of Multi-dimensional-analysis and Experimental Design are introduced to identify the contributions of each vibration sources and transmission paths to interior noise. It was used 3inputs/1output system and found the magnitudes and phases of the forces for minimizing the noise. Finally, the synthesized interior booming noise level is predicted by the vector synthesis diagram. It is shown that the vector synthesis method can be used to obtain the optimum design characteristic of the mounting system to control the interior booming noise of a vehicle.

• Computational Structural Engineering
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• v.9 no.2
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• pp.115-120
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• 1996

The main concern of numerical dynamic analysis of large structures is to find an acceptable solution with fewer mode shapes and less computational efforts. Component mode method utilizes substructure technique to reduce the degree of freedom but have a disadvantage to not consider the dynamic characteristics of loads. Ritz Vector method consider the load characteristics but requires many integrations and errors are accumulated. In this study, to improve the effectiveness of component mode method, Lanczos algorithm is introduced. To prove the effectiveness of this method, example structure are analyzed and the results are compared with SAP90.

• Journal of Life Science
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• v.27 no.5
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• pp.524-529
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• 2017

This study was aimed to produce a transgenic zebrafish expressing the human KCNE1 gene. Initially, the entire CDS of the human KCNE1 gene was amplified from a human genomic DNA sample by polymerase chain reaction using a primer set engineered with restriction enzyme sites (EcoRI, BamHI) at the 5' end of each primer. The resultant 402 bp KCNE1 amplicon flanked by EcoR1 and BamH1 was obtained and subsequently cloned into a plasmid vector pPB-CMVp-EF1-GreenPuro. The integrity of the cloned CDS sequence was confirmed by DNA sequencing analysis. Next, the recombinant vector containing the human KCNE1 (pPB-CMVp-hKCNE1-EF1-GreenPuro) was introduced into fertilized eggs of zebrafish by microinjection. Successful expression of the recombinant vector in the eggs was confirmed by the expression of the fluorescence protein encoded in the vector. Finally, in order to assure that the stable expression of the human KCNE1 gene occurred in the transgenic animal, RNAs were extracted from the animal and the presence of KCNE1 transcripts was confirmed by RT-PCT as well as DNA sequencing analysis. The study provides a methodology to construct a useful transgenic animal model applicable to the development of diagnostic technologies for gene therapy of LQTS (Long QT Syndrome) as well as tools for cloning of useful genes in fish.

• YAKHAK HOEJI
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• v.49 no.3
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• pp.217-224
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• 2005

Human Immunodeficiency Virus type 1 (HIV-l) based lentivirus vector has demonstrated great potential as gene therapy vectors mediating efficient gene delivery and long-term transgene expression in both dividing and nondividing cells. However, for clinical studies it must be confirmed that vector preparations are safe and not contaminated by replication competent lentivirus (RCL) related to the parental pathogenic virus, HIV-l. In this study, we would like to establish the method for titration and RCL detection of lentivirus vector. The titration was determined by vector expression containing the green fluorescent protein, GFP in transduced cells. The titer was $1{\times}10^7$ Transducing Unit/ml in the GFP expression assay and $8.9{\times}10^7$ molecules/ml in the real-time PCR. Also, for the detection of RCL, we have used a combination method of PCR and p24 antigen detection. First, PBS/psi and VSV-G region in the genomic DNA of transduced cells was detected by PCR assay. Second, transfer and expression of the HIV-1 gag gene was detected by p24 ELISA. In an attempt to amplify any RCL, the transduced cells were cultured for 3 weeks (amplification phase) and the supernatant of amplified transduced cell was used for the second transduction to determine whether a true RCL was present (indicator phase). Analysis of cells and supernatant at day 6 in indicator phase were negative for PBS/psi, VSV-G, and p24 antigen. These results suggest that they are not mobilized and therefore there are no RCL in amplification phase. Thus, real-time PCR is a reliable and sensitive method for titration and RCL detection of lentivirus vector.

• Geophysics and Geophysical Exploration
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• v.12 no.1
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• pp.17-26
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• 2009

On Aogashima Island, a volcanic island located in the southernmost part of the Izu Seven Islands Chain, vector magnetic anomalies were obtained in a helicopter-borne magnetic survey. The purpose of this study was to understand the volcanic structure of Aogashima Island in order to mitigate future disasters. Commonly, to obtain the magnetic structure of a volcanic island, total intensity anomalies (TIA) have been used, even though they have intrinsic errors that have not been evaluated correctly. Because the total intensity magnetic anomaly (TIA) is not a physical value, it does not satisfy Maxwell's Equations, Laplace's Equation, etc., and so TIA is not suitable for any physical analyses. In addition, it has been conventionally assumed that TIA is the same as the projected total intensity anomaly vector (PTA) for analyses of TIA. However, the effect of the intrinsic error ($\varepsilon_T$ = TIA.PTA) on the analysis results has not been taken into account. To avoid such an effect, vector magnetic anomalies were measured so that a reliable analysis of Aogashima Island magnetization could be carried out. In this study, we evaluated the error in TIA and used vector anomalies to avoid this erroneous effect, in the process obtaining reliable analysis results for 3D, vector magnetization distributions. An area of less than 1 A/m magnetization was found in the south-west part of Aogashima Island at the depth of 1.2 km. Taking the location of fumarolic activity into consideration, the lower-magnetization area was expected to be the source of that fumarolic activity of Aogashima Island.