• BMB Reports
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• v.53 no.11
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• pp.565-575
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• 2020

Gene therapy is emerging as a treatment option for inherited genetic diseases. The success of this treatment approach greatly depends upon gene delivery vectors. Researchers have attempted to harness the potential of viral vectors for gene therapy applications over many decades. Among the viral vectors available, gutless adenovirus (GLAd) has been recognized as one of the most promising vectors for in vivo gene delivery. GLAd is constructed by deleting all the viral genes from an adenovirus. Owing to this structural feature, the production of GLAd requires a helper that supplies viral proteins in trans. Conventionally, the helper is an adenovirus. Although the helper adenovirus efficiently provides helper functions, it remains as an unavoidable contaminant and also generates replication-competent adenovirus (RCA) during the production of GLAd. These two undesirable contaminants have raised safety concerns and hindered the clinical applications of GLAd. Recently, we developed helper virus-free gutless adenovirus (HF-GLAd), a new version of GLAd, which is produced by a helper plasmid instead of a helper adenovirus. Utilization of this helper plasmid eliminated the helper adenovirus and RCA contamination in the production of GLAd. HF-GLAd, devoid of helper adenovirus and RCA contaminants, will facilitate its clinical applications. In this review, we discuss the characteristics of adenoviruses, the evolution and production of adenoviral vectors, and the unique features of HF-GLAd as a new platform for gene therapy. Furthermore, we highlight the potential applications of HF-GLAd as a gene delivery vector for the treatment of various inherited genetic diseases.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.5
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• pp.329-336
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• 2015

This paper presents a sorting method of mode vectors and natural frequencies about a rotor-journal bearing system. The rotor is solved by the finite element method, the bearing stiffness and damping coefficient are solved by the finite difference method. At any rotation speed section through the eigenvalue analysis of the system, mode vectors and natural frequencies not sorted are confirmed via the Campbell diagram and the MAC(modal assurance criterion). To sort mode vectors and natural frequencies of the section, a mode sorting method is presented through a method of rearranging the MAC of the mode vectors. Finally, the mode vectors and the natural frequencies are sorted by using the presented method, these are verified through the MAC.

• Journal of Sensor Science and Technology
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• v.29 no.4
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• pp.237-242
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• 2020

This paper deals with relative position estimation using a Kalman filter (KF) based on inertial sensors that have been widely used in various biomechanics-related outdoor applications. In previous studies, the relative position is determined using relative orientation and predetermined segment-to-joint (S2J) vectors, which are assumed to be constant. However, because body segments are influenced by soft tissue artifacts (STAs), including the deformation and sliding of the skin over the underlying bone structures, they are not constant, resulting in significant errors during relative position estimation. In this study, relative position estimation was performed using a KF, where the S2J vectors were adopted as time-varying states. The joint constraint and the variations of the S2J vectors were used to develop a measurement model of the proposed KF. Accordingly, the covariance matrix corresponding to the variations of the S2J vectors continuously changed within the ranges of the STA-causing flexion angles. The experimental results of the knee flexion tests showed that the proposed KF decreased the estimation errors in the longitudinal and lateral directions by 8.86 and 17.89 mm, respectively, compared with a conventional approach based on the application of constant S2J vectors.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.4
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• pp.551-558
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• 2003

An efficient and reliable subspace iteration algorithm using the block algorithm is proposed. The block algorithm is the method dividing eigenpairs into several blocks when a lot of eigenpairs are required. One of the key for the faster convergence is carefully selected initial vectors. As the initial vectors, the proposed method uses the modified Ritz vectors for guaranteering all the required eigenpairs and the quasi-static Ritz vectors for accelerating convergency of high frequency eigenvectors. Applying the quasi-static Ritz vectors, a shift is always required, and the proper shift based on the geometric average is proposed. To maximize efficiency, this paper estimates the proper number of blocks based on the theoretical amount of calculation in the subspace iteration. And it also considers the problems generated in the process of combining various algorithms and the solutions to the problems. Several numerical experiments show that the proposed subspace iteration algorithm is very efficient, reliable ,and accurate.

• Journal for History of Mathematics
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• v.20 no.2
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• pp.59-72
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• 2007

There are three kinds of order of instruction in mathematics, that is, historical order, theoretical organization and lecturing organization-order. Simply speaking, each lecturing organization-order is a combination of two preceding orders. The problem is how to combine between them. In a recent paper, we concretely considered this problem for the case of the concept of angle. The present paper analogously discuss with the concept of vectors. To begin with, we investigate theoretical organization and historical order of the concept of vectors as materials for the construction of its lecturing organization-order. It enables us to establish 4 stages in historical order of the concept of vectors proper to its theoretical organization. As a consequence, we suggest several criteria and forms for constructing its lecturing organization-order.

• Journal of Power Electronics
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• v.16 no.6
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• pp.2162-2172
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• 2016

This paper presents a Direct Torque Control (DTC) strategy for the five-phase induction motor driven by a three-level five-phase inverter in order to improve the performance of the five-phase induction motor. In the proposed DTC technique, only 22 voltage vectors out of 243 available voltage vectors in a three-level five-phase inverter are selected and are divided in 10 sectors each with a width of $36^{\circ}$. The four different DTC combinations (DTC-I, II, III and IV) for a three-level five-phase induction motor drive are investigated for improving the performance of five-phase induction motor. All four of the DTC strategies utilize a combination of the same large and zero voltage vectors, but with different medium voltage vectors. Out of these four techniques, DTC-II gives the best performance when compared to the others. This DTC-II technique is analyzed in detail for improvements in the performance of five-phase induction motor in terms of torque ripple, x-y stator flux and Total Harmonics Distortion (THD) of the stator phase current when compared to its two-level counterparts. To verify the effectiveness of the proposed three-level five-phase DTC control strategy, a DSP based experimental system is build. Simulation and experimental results are provided in order to validate the proposed DTC technique.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.2 s.308
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• pp.33-39
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• 2006

This paper presents the modified LVQ method for performance improvement of pattern classification. The proposed method uses the skewness of probability distribution between the input vectors and the reference vectors. During training, the reference vectors are closest to the input vectors using the probabilistic distribution of the input vectors, and they are positioned to approximate the decision surfaces of the theoretical Bayes classifier. In order to verify the effectiveness of the proposed method, we performed experiments on the Gaussian distribution data set, and the Fisher's IRIS data set. The experimental results show that the proposed method considerably improves on the performance of the LVQ1, LVQ2, and GLVQ.

• Molecules and Cells
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• v.40 no.5
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• pp.339-345
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• 2017

Retroviral and lentiviral vectors are mostly pseudotyped and often purified and concentrated via ultracentrifugation. In this study, we quantified and compared the stabilities of retroviral [murine leukemia virus (MLV)-based] and lentiviral [human immunodeficiency virus (HIV)-1-based] vectors pseudotyped with relatively mechanically stable envelope proteins, vesicular stomatitis virus glycoproteins (VSVGs), and the influenza virus WSN strain envelope proteins against ultracentrifugation. Lentiviral genomic and functional particles were more stable than the corresponding retroviral particles against ultracentrifugation when pseudotyped with VSVGs. However, both retroviral and lentiviral particles were unstable when pseudotyped with the influenza virus WSN strain envelope proteins. Therefore, the stabilities of pseudotyped retroviral and lentiviral vectors against ultracentrifugation process are a function of not only the type of envelope proteins, but also the type of viral internal core (MLV or HIV-1 core). In addition, the fraction of functional viral particles among genomic viral particles greatly varied at times during packaging, depending on the type of envelope proteins used for pseudotyping and the viral internal core.

• Parasites, Hosts and Diseases
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• v.58 no.5
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• pp.589-592
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• 2020

Cyclospora cayetanensis is an apicomplexan protozoan and is one of the most common pathogens causing chronic diarrhea worldwide. Eight stool samples with diarrheal symptom out of 18 Korean residents who traveled to Nepal were obtained, and examined for 25 enteropathogens including 16 bacterial species, 5 viral species, and 4 protozoans in stool samples as causative agents of water-borne and food-borne disease. Only C. cayetanensis was detected by nested PCR, and 3 PCR-positive samples were sequenced to confirm species identification. However, the oocysts of C. cayetanensis in fecal samples could not be detected by direct microscopy of the stained sample. As far as we know, this is the first report of a group infection with C. cayetanensis from a traveler visiting Nepal, and the second report of a traveler's diarrhea by C. cayetanensis imported in Korea.

• Journal of the Korean Statistical Society
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• v.22 no.2
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• pp.339-345
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• 1993

It is well known that distribution of functions of eigen values and vectors of a certain matrix plays an important role in multivariate analysis. This paper deals with the transformation of a correlation-type random matrix to its eigen values and vectors. Properties of the transformation are also considered. The results obtained are applied to express the joint distribution of eigen values and vectors of the correlation matrix when sample is taken from a m-variate spherical distribution.