• 제목/요약/키워드: Genetic evaluation

검색결과 891건 처리시간 0.022초

전자빔 마스터링을 위한 공기베어링 응용 고진공 회전테이블의 설계 및 진공특성 평가 (Design and Evaluation of a Rotation Table using Air Bearings for Electron Beam Mastering)

  • 김경호;송창규;박천홍
    • 한국정밀공학회지
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    • 제25권12호
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    • pp.132-138
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    • 2008
  • Recently, mastering processes for high density optical disc such as Blu-ray disc rely on electron beams, which are operable in only vacuum. In the mastering process, one of the most important tasks is to design precision stages for providing precise positioning of the works with respect to the source in a high vacuum environment. In this paper, we have developed a precision rotation table usable in the electron beam mastering. The rotation table adopted air bearings for a high positioning repeatability and velocity stability. The air leakage from the air bearings has been minimized by employing the differential exhaust scheme using three steps of air drain. The design parameters such as diameters of exhaust lines, seal lengths, and pumping speeds were decided according to the optimization method using genetic algorithm. The performance on the vacuum level of the rotation table was evaluated experimentally and theoretically. The results indicate that a vacuum level of $10^{-4}$ Pa is achieved with operation of air bearings in a vacuum chamber, which is sufficient for the electron beam mastering.

진동측정을 위한 스트레인 게이지 설치위치 최적화 : 최적화 방법 및 평가 (Optimal Placement of Strain Gauge for Vibration Measurement : Formulation and Assessment)

  • 최창림;양보석;최병근
    • 한국소음진동공학회논문집
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    • 제14권8호
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    • pp.757-766
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    • 2004
  • This paper focuses on the formulation and validation of an automatic strategy to select the optimal location and direction of strain gauges for the measurement of the modal response. These locations and directions are important to render the strain measurements as robust as possible when a random mispositioning of the gauges and gauge failures are expected. The approach relies on the evaluation of the signal-to-noise ratios of the gauge measurements from strain data of finite element. The multi-step optimization strategy including genetic algorithm is used to find the strain gauge locations-directions that maximize the smallest modal strain signal-to-noise ratio in the absence of gauge failure or its expected value when gauge failure is possible. A flat Plate is used to prove the applicability of the proposed methodology and to demonstrate the effects of the essential parameters of the problem such as the mispositioning level, the probability of gauge failure, and the number of gauges.

Identification and Phylogeny of the Human Endogenous Retrovirus HERV-W LTR Family in Cancer Cells

  • Yi, Joo-Mi;Kim, Hwan-Mook;Kim, Heui-Soo
    • Animal cells and systems
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    • 제6권2호
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    • pp.167-170
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    • 2002
  • The long terminal repeats (LTRs) of human endogenous retrovirus (HERV) have been found to be coexpressed with sequences of closely located genes. It has been suggested that the LTR elements have contributed to the structural change or genetic variation of human genome connected to various diseases and evolution. We examined the HERV-W LTR elements in various cancer cells (2F7, A43l , A549, HepG2, MIA-PaCa-2, PC-3, RT4, SiHa, U-937, and UO-31). Using genomic DNA from the cancer cells, we performed PCR amplification and identified twelve new HERV-W LTR elements. Those LTR elements showed a high degree of sequence similarity (88-99%) with HERV-W LTR (AF072500). A phylogenetic tree obtained by the neighbor-joining method revealed that HERV-W LTR elements could be mainly divided into two groups through evolutionary divergence. Three HERV-W LTR elements (RT4-2, A43l-1, and UO3l-2) belonged to Group 1, whereas nine LTR elements (2F7-2, A549-1, A549-3, HepG2-3, MP2-2, PC3-1, SiHa-8, SiHa-10, and U937-1) belonged to Group 11. Taken together, our new sequence data of the HERV-W LTR elements may contribute to an understanding of tissue-specific cancer by genomic instability of LTR integration.

합성화학물질들의 유전독성평가(XV) -마우스의 말초혈의 망상적혈구를 이용한 17종 합성화학물질들의 생체내 소핵시험- (Evaluation of the Genetic Toxicity of Synthetic Chemicals (XV) -In vivo Peripheral Blood Reticulocytes Micronucleus Assay of 17 Synthetic Chemicals in Mice-)

  • 김미순;김연정;류재천
    • Environmental Analysis Health and Toxicology
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    • 제21권3호
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    • pp.209-218
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    • 2006
  • 합성화학물질들이 환경으로의 유입은 인체에는 물론 환경생태계에 많은 영향을 미치므로 이들의 유해성 검증은 매우 중요한 일이라 할 수 있다. 실제 산업체에서 사용되는 수많은 화학물질들의 유전적 손상 유발유무는 유해성검증에서 무엇보다 중요한 일이라 할 수 있다. 이에 산업체 공정과정에서 널리 사용되는 것으로 알려진 17종의 합성화학물질에 대해 마우스의 말초 혈의 망상적혈구를 이용한 in vivo 소핵시험을 수행하여, 소핵형성 유발유무를 관찰하였다. 양성대조군으로 사용된 mitomycin C는 음성대조군과 비교시 유의하게 소핵을 유발하는 반면, 비교적 마우스에서 높은 50% 치사량을 보이는 benzoyl chloride, p-toluene sulfonic acid 및 4,4'-sulfonyldianiline 등의 합성물질들을 포함한 총 17종의 물질들은 본 실험결과 통계적으로 유의하게 소핵을 유발하지 않는 것을 관찰 할 수 있었다.

소분자 도킹에서의 평가함수의 개발 동향 (Recent Development of Scoring Functions on Small Molecular Docking)

  • 정환원;조승주
    • 통합자연과학논문집
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    • 제3권1호
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    • pp.49-53
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    • 2010
  • Molecular docking is a critical event which mostly forms Van der waals complex in molecular recognition. Since the majority of developed drugs are small molecules, docking them into proteins has been a prime concern in drug discovery community. Since the binding pose space is too vast to cover completely, many search algorithms such as genetic algorithm, Monte Carlo, simulated annealing, distance geometry have been developed. Proper evaluation of the quality of binding is an essential problem. Scoring functions derived from force fields handle the ligand binding prediction with the use of potential energies and sometimes in combination with solvation and entropy contributions. Knowledge-based scoring functions are based on atom pair potentials derived from structural databases. Forces and potentials are collected from known protein-ligand complexes to get a score for their binding affinities (e.g. PME). Empirical scoring functions are derived from training sets of protein-ligand complexes with determined affinity data. Because non of any single scoring function performs generally better than others, some other approaches have been tried. Although numerous scoring functions have been developed to locate the correct binding poses, it still remains a major hurdle to derive an accurate scoring function for general targets. Recently, consensus scoring functions and target specific scoring functions have been studied to overcome the current limitations.

Application of a Hybrid System of Probabilistic Neural Networks and Artificial Bee Colony Algorithm for Prediction of Brand Share in the Market

  • Shahrabi, Jamal;Khameneh, Sara Mottaghi
    • Industrial Engineering and Management Systems
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    • 제15권4호
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    • pp.324-334
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    • 2016
  • Manufacturers and retailers are interested in how prices, promotions, discounts and other marketing variables can influence the sales and shares of the products that they produce or sell. Therefore, many models have been developed to predict the brand share. Since the customer choice models are usually used to predict the market share, here we use hybrid model of Probabilistic Neural Network and Artificial Bee colony Algorithm (PNN-ABC) that we have introduced to model consumer choice to predict brand share. The evaluation process is carried out using the same data set that we have used for modeling individual consumer choices in a retail coffee market. Then, to show good performance of this model we compare it with Artificial Neural Network with one hidden layer, Artificial Neural Network with two hidden layer, Artificial Neural Network trained with genetic algorithms (ANN-GA), and Probabilistic Neural Network. The evaluated results show that the offered model is outperforms better than other previous models, so it can be use as an effective tool for modeling consumer choice and predicting market share.

Gene Co-Expression Network Analysis of Reproductive Traits in Bovine Genome

  • Lim, Dajeong;Cho, Yong-Min;Lee, Seung-Hwan;Chai, Han-Ha;Kim, Tae-Hun
    • Reproductive and Developmental Biology
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    • 제37권4호
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    • pp.185-192
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    • 2013
  • Many countries have implemented genetic evaluation for fertility traits in recent years. In particular, reproductive trait is a complex trait and need to require a system-level approach for identifying candidate genes related to the trait. To find the candidate gene associated with reproductive trait, we applied a weighted gene co-expression network analysis from expression value of bovine genes. We identified three co-expressed modules associated with reproductive trait from bovine microarray data. Hub genes (ZP4, FHL2 and EGR4) were determined in each module; they were topologically centered with statistically significant value in the gene co-expression network. We were able to find the highly co-expressed gene pairs with a correlation coefficient. Finally, the crucial functions of co-expressed modules were reported from functional enrichment analysis. We suggest that the network-based approach in livestock may an important method for analyzing the complex effects of candidate genes associated with economic traits like reproduction.

Ginsenoside Rp1 Inhibits Proliferation and Migration of Human Lung Cancer Cells

  • Hong, Sam-Yeol;Cho, Jae-Youl;Seo, Dong-Wan
    • Biomolecules & Therapeutics
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    • 제19권4호
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    • pp.411-418
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    • 2011
  • Ginsenoside Rp1 (G-Rp1) is a novel ginseng saponin derivative with anti-tumor activity. However, the biochemical and molecular mechanisms of G-Rp1 on anti-tumor activity are not fully understood. In the present study, we report that G-Rp1 inhibits lung cancer cell proliferation, migration and adhesion in p53 wild-type A549 and p53-defi cient H1299 cells. Anti-proliferative activity of G-Rp1 in lung cancer cells is mediated by enhanced nuclear localization of cyclin-dependent kinase inhibitors including $p27^{Kip1}$ and $p21^{WAF1/Cip1}$, and subsequent inhibition of pRb phosphorylation. We also show that these anti-tumor activities of G-Rp1 in both A549 and H1299 cells appear to be mediated by suppression of mitogenic signaling pathways such as ERK, Akt and $p70^{S6K}$. Taken together, these findings suggest further development and evaluation of G-Rp1 for the treatment of lung cancers with mutated p53 as well as wild-type p53.

Marfan syndrome and symptomatic dural ectasia: A case report and literature review

  • Eom, Si Nae;Kim, Dong Chan;Kim, Kwang Nam;Kim, Sung Hye
    • Journal of Genetic Medicine
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    • 제11권2호
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    • pp.83-85
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    • 2014
  • Dural ectasia refers to the widening or ballooning of the dural sac surrounding the spinal cord. It can affect any plane of the spinal canal, but occurs primarily in the lumbosacral region. Dural ectasia is present in 63-92% patients who have Marfan syndrome, and is related to Ehlers-Danlos syndrome, neurofibromatosis type I, and ankylosing spondylitis. The most common symptoms are low back pain, headache, weakness, numbness above and below the affected limb, and occasional rectal and genital pain. However, in most patients, dural ectasia is usually asymptomatic. We report the case of a 5-year-old boy who presented with a severe headache who had been diagnosed with Marfan syndrome. During the evaluation, magnetic resonance imaging of the lumbar and sacral spine revealed dural ectasia. To our knowledge, this is the first report on Marfan syndrome with symptomatic dural ectasia in Korea. We concluded that dural ectasia should be suspected in patients diagnosed with Marfan syndrome who have a severe headache.