• 제목/요약/키워드: Null-vector

검색결과 67건 처리시간 0.023초

Location and Gain/Phase Calibration Techniques for Array Sensors with known Sources (기준신호원을 이용한 배열센서의 위치, 이득, 위상 보정기법)

  • Yoo, Seong Ki;Lee, Tae Beom;Shin, Ki Young
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • 제49권9호
    • /
    • pp.155-163
    • /
    • 2012
  • The geometrical and electrical errors of array sensors can severely degrade the performance of array sensor system. Various calibration techniques are developed to alleviate this problem. In this paper, two different calibration methods with respect to location, gain and phase of array sensors are presented. One method applies the first-order Taylor series expansion to approximate the true steering vector from the nominal values of array sensors. Then a set of equations is formed by using the null characteristics of the MUSIC spectrum to estimate errors of location, gain and phase of array sensors. Another method estimates these errors based on the data covariance matrix of pilot sources. From the simulations, it is demonstrated that two calibration algorithms calibrated an array system successfully. In addition to that, Fistas and Manikas's algorithm is more robust against noise than Ng and Lie's one when SNR is from 10dB to 50dB.

A Novel Image Encryption using Complemented MLCA based on NBCA and 2D CAT (NBCA 에 기초한 여원 MLCA와 2D CAT를 이용한 새로운 영상 암호화)

  • Kim, Ha-Kyung;Nam, Tae-Hee;Cho, Sung-Jin;Kim, Seok-Tae
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • 제36권6C호
    • /
    • pp.361-367
    • /
    • 2011
  • In this paper, we propose encryption method to using complemented MLCA(Maximum Length Cellular Automata) based on NBCA(Null Boundary CA) and 2D CAT (Two-Dimensional Cellular Automata Transform) for efficient image encryption. The encryption method is processed in the following order. First, a transition matrix T is created using the Wolfram Rule matrix. Then, the transition matrix T is multiplied to the original image that is intended to be encrypted, which transfers the pixel values of the original image. Furthermore, the converted original image goes through a XOR operation with complemented vector F to convert into a complemented MLCA applied image. Then, the gateway value is set and 2D CAT basis function is created. Also, the 2D CAT is encrypted by multiplying the created basis function to the complemented MLCA applied image. Lastly, the stability analysis verifies that proposed method holds a high encryption quality status.

Effects of Ribosomal Protein L39-L on the Drug Resistance Mechanisms of Lung Cancer A549 Cells

  • Liu, Hong-Sheng;Tan, Wen-Bin;Yang, Ning;Yang, Yuan-Yuan;Cheng, Peng;Liu, Li-Juan;Wang, Wei-Jie;Zhu, Chang-Liang
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제15권7호
    • /
    • pp.3093-3097
    • /
    • 2014
  • Background: Cancer is a major threat to the public health whether in developed or in developing countries. As the most common primary malignant tumor, the morbidity and mortality rate of lung cancer continues to rise in recent ten years worldwide. Chemotherapy is one of the main methods in the treatment of lung cancer, but this is hampered by chemotherapy drug resistance, especially MDR. As a component of the 60S large ribosomal subunit, ribosomal protein L39-L gene was reported to be expressed specifically in the human testis and human cancer samples of various tissue origins. Materials and Methods: Total RNA of cultured drug-resistant and susceptible A549 cells was isolated, and real time quantitative RT-PCR were used to indicate the transcribe difference between amycin resistant and susceptible strain of A549 cells. Viability assay were used to show the amycin resistance difference in RPL39-L transfected A549 cell line than control vector and null-transfected A549 cell line. Results: The ribosomal protein L39-L transcription level was 8.2 times higher in drug-resistant human lung cancer A549 cell line than in susceptible A549 cell line by quantitative RT-PCR analysis. The ribosomal protein L39-L transfected cells showed enhanced drug resistance compared to plasmid vector-transfected or null-transfected cells as determined by methyl tritiated thymidine (3H-TdR) incorporation. Conclusions and Implications for Practice: The ribosomal protein L39-L gene may have effects on the drug resistance mechanism of lung cancer A549 cells.

Recent Progress in Biotechnology-based Gene Manipulating Systems to Produce Knock-In/Out Mouse Models

  • Lee, Woon Kyu;Park, Joong Jean;Cha, Seok Ho;Yun, Cheol-Heui
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제21권5호
    • /
    • pp.745-753
    • /
    • 2008
  • Gene-manipulated mice were discovered for the first time about a quarter century ago. Since then, numerous sophisticated technologies have been developed and applied to answer key questions about the fundamental roles of the genes of interest. Functional genomics can be characterized into gain-of-function and loss-of-function, which are called transgenic and knock-out studies, respectively. To make transgenic mice, the most widely used technique is the microinjection of transgene-containing vectors into the embryonic pronucleus. However, there are critical drawbacks: namely position effects, integration of unknown copies of a foreign gene, and instability of the foreign DNA within the host genome. To overcome these problems, the ROSA26 locus was used for the knock-in site of a transgene. Usage of this locus is discussed for the gain of function study as well as for several brilliant approaches such as conditional/inducible transgenic system, reproducible/inducible knockdown system, specific cell ablation by Cre-mediated expression of DTA, Cre-ERTM mice as a useful tool for temporal gene regulation, MORE mice as a germ line delete and site specific recombinase system. Techniques to make null mutant mice include complicated steps: vector design and construction, colony selection of embryonic stem (ES) cells, production of chimera mice, confirmation of germ line transmission, and so forth. It is tedious and labor intensive work and difficult to approach. Thus, it is not readily accessible by most researchers. In order to overcome such limitations, technical breakthroughs such as reporter knock-in and gene knock-out system, production of homozygous mutant ES cells from a single targeting vector, and production of mutant mice from tetraploid embryos are developed. With these upcoming progresses, it is important to consider how we could develop these systems further and expand to other animal models such as pigs and monkeys that have more physiological similarities to humans.

A Supervised Feature Selection Method for Malicious Intrusions Detection in IoT Based on Genetic Algorithm

  • Saman Iftikhar;Daniah Al-Madani;Saima Abdullah;Ammar Saeed;Kiran Fatima
    • International Journal of Computer Science & Network Security
    • /
    • 제23권3호
    • /
    • pp.49-56
    • /
    • 2023
  • Machine learning methods diversely applied to the Internet of Things (IoT) field have been successful due to the enhancement of computer processing power. They offer an effective way of detecting malicious intrusions in IoT because of their high-level feature extraction capabilities. In this paper, we proposed a novel feature selection method for malicious intrusion detection in IoT by using an evolutionary technique - Genetic Algorithm (GA) and Machine Learning (ML) algorithms. The proposed model is performing the classification of BoT-IoT dataset to evaluate its quality through the training and testing with classifiers. The data is reduced and several preprocessing steps are applied such as: unnecessary information removal, null value checking, label encoding, standard scaling and data balancing. GA has applied over the preprocessed data, to select the most relevant features and maintain model optimization. The selected features from GA are given to ML classifiers such as Logistic Regression (LR) and Support Vector Machine (SVM) and the results are evaluated using performance evaluation measures including recall, precision and f1-score. Two sets of experiments are conducted, and it is concluded that hyperparameter tuning has a significant consequence on the performance of both ML classifiers. Overall, SVM still remained the best model in both cases and overall results increased.

Drug Resistance Effects of Ribosomal Protein L24 Overexpression in Hepatocellular Carcinoma HepG2 Cells

  • Guo, Yong-Li;Kong, Qing-Sheng;Liu, Hong-Sheng;Tan, Wen-Bin
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제15권22호
    • /
    • pp.9853-9857
    • /
    • 2014
  • Background: The morbidity and mortality rate of liver cancer continues to rise in China and advanced cases respond poorly to chemotherapy. Ribosomal protein L24 has been reported to be a potential therapeutic target whose depletion or acetylation inhibits polysome assembly and cell growth of cancer. Materials and Methods: Total RNA of cultured amycin-resistant and susceptible HepG2 cells was isolated, and real time quantitative RT-PCR were used to indicate differences between amycin-resistant and susceptible strains of HepG2 cells. Viability assays were used to determine amycin resistance in RPL24 transfected and control vector and null-transfected HepG2 cell lines. Results: The ribosomal protein L24 transcription level was 7.7 times higher in the drug-resistant HepG2 cells as compared to susceptible cells on quantitative RT-PCR analysis. This was associated with enhanced drug resistance as determined by methyl tritiated thymidine (3H-TdR) incorporation. Conclusions: The ribosomal protein L24 gene may have effects on drug resistance mechanisms in hepatocellular carcinoma HepG2 cells.

In Vivo Expression of the PTB-deleted Odin Mutant Results in Hydrocephalus

  • Park, Sunjung;Lee, Haeryung;Park, Soochul
    • Molecules and Cells
    • /
    • 제38권5호
    • /
    • pp.426-431
    • /
    • 2015
  • Odin has been implicated in the downstream signaling pathway of receptor tyrosine kinases, such as the epidermal growth factor and Eph receptors. However, the physiologically relevant function of Odin needs to be further determined. In this study, we used Odin heterozygous mice to analyze the Odin expression pattern; the targeted allele contained a ${\beta}$-geo gene trap vector inserted into the 14t intron of the Odin gene. Interestingly, we found that Odin was exclusively expressed in ependymal cells along the brain ventricles. In particular, Odin was highly expressed in the subcommissural organ, a small ependymal glandular tissue. However, we did not observe any morphological abnormalities in the brain ventricles or ependymal cells of Odin null-mutant mice. We also generated BAC transgenic mice that expressed the PTB-deleted Odin (dPTB) after a floxed GFP-STOP cassette was excised by tissue-specific Cre expression. Strikingly, Odin-dPTB expression played a causative role in the development of the hydrocephalic phenotype, primarily in the midbrain. In addition, Odin-dPTB expression disrupted proper development of the subcommissural organ and interfered with ependymal cell maturation in the cerebral aqueduct. Taken together, our findings strongly suggest that Odin plays a role in the differentiation of ependymal cells during early postnatal brain development.

DECOMPOSITION OF SPECIAL PSEUDO PROJECTIVE CURVATURE TENSOR FIELD

  • MOHIT SAXENA;PRAVEEN KUMAR MATHUR
    • Journal of applied mathematics & informatics
    • /
    • 제41권5호
    • /
    • pp.989-999
    • /
    • 2023
  • The aim of this paper is to study the projective curvature tensor field of the Curvature tensor Rijkh on a recurrent non Riemannian space admitting recurrent affine motion, which is also decomposable in the form Rijkh=Xi Yjkh, where Xi and Yjkh are non-null vector and tensor respectively. In this paper we decompose Special Pseudo Projective Curvature Tensor Field. In the sequal of decomposition we established several properties of such decomposed tensor fields. We have considered the curvature tensor field Rijkh in a Finsler space equipped with non symmetric connection and we study the decomposition of such field. In a special Pseudo recurrent Finsler Space, if the arbitrary tensor field 𝜓ij is assumed to be a covariant constant then, in view of the decomposition rule, 𝜙kh behaves as a recurrent tensor field. In the last, we have considered the decomposition of curvature tensor fields in Kaehlerian recurrent spaces and have obtained several related theorems.

Effect of Adenovirus-p53 to Non-Small Cell Lung Cancer Cell Lines (Adenovirus-p53이 비소세포폐암세포 성장에 미치는 영향에 관한 연구)

  • 박종호;이춘택;김주현
    • Journal of Chest Surgery
    • /
    • 제31권12호
    • /
    • pp.1134-1146
    • /
    • 1998
  • Background: The tumor suppressor gene p53 is one of the most frequently altered genes in human tumors, including those of the lung. There is now a compelling evidence that wild-type p53 can negatively influence cell growth by causing G1 arrest or by inducing apoptosis. The possibilities of using p53 for gene therapy are also gathering much interest. Material and Method: Our approach towards understanding p53 function would be to study the biological consequences of overexpression of wild-type p53 in normal and tumor cells by using adenovirus vectors capable of giving high levels of the p53 gene product in cells. We have used this vector containing wild-type p53 to infect tumor cells with different p53 status (null, mutant, or wild-type) to confirm that expression of p53 in null or mutant cell lines becomes possible by Adenovirus-p53 transduction, to examine the effects of high levels of p53 expression on the growth properties of tumor cells, to evaluate the role of apoptosis in p53-mediated biological effects, and to examine the effect of Adenovirus-p53 on the tumorigenicities of the lung cancer cell lines in vitro. Result: The results of our study showed that cells expressing endogenous mutant p53 and those devoid of p53 expression altogether were significantly more sensitive to Adenovirus-p53-mediated cytotoxicity compared to tumor cells expressing endogenous wild-type p53 and that overexpression of wild-type p53 induced programmed cell death. Also we knew that Adenovirus-p53 significantly reduced tumor colony formation of human non-small cell lung cancer cell lines, and decreased the growth of pre-formed colonies in vitro. Conclusion: These results suggest that adenovirus is an efficient vector for mediating transfer and expression of tumor suppressor genes in human non-small cell lung cancer cells and that the tumor cells null for p53 or expressing mutant p53 readily undergo apoptosis by Adenovirus-p53.

  • PDF

Radiosensitization Effect of Overexpression of Adenovirus-mediated SIRT6 on A549 Non-small Cell Lung Cancer Cells

  • Cai, Yong;Sheng, Zhao-Ying;Liang, Shi-Xiong
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제15권17호
    • /
    • pp.7297-7301
    • /
    • 2014
  • Objective: To explore the radiosensitization effect of overexpression of silent information regulator 6 (SIRT6) on A549 non-small cell lung cancer (NSCLC) cells. Methods: Adenovirus vector Ad-SIRT6 causing overexpression of SIRT6 was established. Western blotting and MTT assay were adopted to detect the level of SIRT6 protein and the inhibitory rate of A549 cell proliferation after different concentrations of adenovirus transduction (0, 25, 100, 200, and 400 pfu/cell) for 24 h. Control group, Ad-null group and Ad-SIRT6 group were designed in this experiment and virus concentration of the latter two groups was 200 pfu/cell. Colony formation assays were employed to test survival fraction (SF) of the 3 groups after 0, 2, 4, 6, 8, 10 X-ray irradiation. Flow cytometry was used to detect the status of cell cycle of 3 groups after 48 h of 4Gy X-ray irradiation and Western blotting was used to determine the expression of apoptosis-related genes of 3 groups after 48 h of 4GyX-ray irradiation. Results: In the range of 25~400 pfu/cell, the inhibitory rate of A549 cell proliferation increased as adenovirus concentration raised. The inhibitory rates under the concentrations of 0, 25, 100, 200, and 400 pfu/cell were 0%, $4.23{\pm}0.34%$, $12.7{\pm}2.57%$, $22.6{\pm}3.38%$, $32.2{\pm}3.22%$, $38.7{\pm}4.09%$ and $47.8{\pm}5.58%$ and there were significantly differences among groups (P<0.05). SF in Ad-SIRT6 group was lower than Ad-null and control groups after 4~10Gy X-ray irradiation (P<0.05) and the sensitization enhancement ratio (SER) was 1.35 when compared with control group. Moreover, after 48 h of 4Gy X-ray irradiation, there appeared a significant increase in G1-phase cell proportion, upregulated expression of the level of apoptosis-promoting genes (Bax and Cleaved caspase-3), but a obvious decline in S-phase and G2-phase cell proportion and a significant decrease of the level of apoptosis-inhibiting gene (Bal-2) in the Ad-SIRT6 group (P<0.05). Conclusion: The over-expression of adenovirus-mediated SIRT6, which has radiosensitization effect on A549 cells of NSCLC, can inhibit the proliferation of A549 cells and cause G0/G1 phase retardation as well as induce apoptosis of cells.