• Korean Journal of Materials Research
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• v.5 no.2
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• pp.151-156
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• 1995

Low temperature firing $(Ba, Sr)TiO_{3}$ dielectrics were successfully prepared with lead based glass and those electrical properties were investigated. Different amount of PbO content glass materials were added to dielectrics to investigate the sinterability and its dielectric properties. Also, various compositions of ceramic capacitors were prepared to applicate in multilayer ceramic capacitors. A large amount of experiment has been done with various Pb contented glasses and different sintering temperatures. The sintering temperature of $(Ba,Sr)TiO_{3}$can be reduced from $1350^{\circ}C$to as low as $1050^{\circ}C$ with 4wt% addition of $PbO-ZnO-B_{2}O_{2}$ glass materials. Its dielectric constant at room temperature was up to 8100 with low dielectric loss, 0.005. This ceramic capacitor showed fully fired microstructures with its grain size of 1-3$\mu \textrm{m}$. The sintered body which was sintered at $1150^{\circ}C$ for 2hr with 4wt% $PbO-ZnO-B_{2}O_{2}$ glass material addition satisfied the Z5U specification of the EIAS.

• Journal of Convergence for Information Technology
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• v.10 no.3
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• pp.76-91
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• 2020

Whole genome sequence of Abeliophyllum distichum Nakai (Oleaceae) cultivar Ok Hwang 1 Ho, which is Korean endemic species, was recently sequenced to understand its characteristics. Acteoside is one of major useful compounds presenting various activities, and its several proposed biochemical pathways were reviewed and integrated to make precise biochemical pathway. Utilizing MetaPre-AI^TM which was developed for predicting secondary metabolites based on whole genome with the precise biochemical pathway of acteoside and the InfoBoss Pathway Database, we successfully rescued all enzymes involved in this pathway from the genome sequences, presenting that A. distichum cultivar Ok Hwang 1 Ho may produce acteoside. High-performance liquid chromatography result displayed that callus of A. distichum cultivar Ok Hwang 1 Ho contained acteoside as well as isoacteoside which may be derived from acteoside. Taken together, we successfully showed that MetaPre-AI^TM can predict secondary metabolite from plant whole genomes. In addition, this method will be efficient to predict secondary metabolites of many plant species because DNA can be analyzed more stability than chemical compounds.

• Journal of Plant Biotechnology
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• v.43 no.3
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• pp.261-271
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• 2016

Citrus is an economically important fruit crop widely growing worldwide. However, citrus production largely depends on natural hybrid selection and bud sport mutation. Unique botanical features including long juvenility, polyembryony, and QTL that controls major agronomic traits can hinder the development of superior variety by conventional breeding. Diverse factors including drastic changes of citrus production environment due to global warming and changes in market trends require systematic molecular breeding program for early selection of elite candidates with target traits, sustainable production of high quality fruits, cultivar diversification, and cost-effective breeding. Since the construction of the first genetic linkage map using isozymes, citrus scientists have constructed linkage maps using various DNA-based markers and developed molecular markers related to biotic and abiotic stresses, polyembryony, fruit coloration, seedlessness, male sterility, acidless, morphology, fruit quality, seed number, yield, early fruit setting traits, and QTL mapping on genetic maps. Genes closely related to CTV resistance and flesh color have been cloned. SSR markers for identifying zygotic and nucellar individuals will contribute to cost-effective breeding. The two high quality citrus reference genomes recently released are being efficiently used for genomics-based molecular breeding such as construction of reference linkage/physical maps and comparative genome mapping. In the near future, the development of DNA molecular markers tightly linked to various agronomic traits and the cloning of useful and/or variant genes will be accelerated through comparative genome analysis using citrus core collection and genome-wide approaches such as genotyping-by-sequencing and genome wide association study.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.11a
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• pp.205-207
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• 2003

In this paper, we propose novel, small and integrated microwave chip filter using high dielectric substrates. A variety of dielectric substrates can be selected for the specifications of products according to dielectric, Q-factors, temperature stability ect. This paper describes an application of the very high dielectric constant (K=133) substrate for design of a band pass filter to a 5.8GHz Transmitter/receiver(T/R) module.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.18-18
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• 2009

본 논문은 X8R 온도 특성을 가지는 유전체 원료를 이용하여 고용량이면서 고압화가 가능한 적층 칩 캐패시터를 제작하였다. 대형 고압용 적층 칩 캐패시터를 위한 내부 전극 설계 및 외부 전극 형성 방법에 대한 연구도 함께 진행하였다. 적층 칩 캐패시터를 하이브리드 자동차 및 산업용 인버터의 DC-Link으로 사용하기 적합한 모듈을 제작하였으며 모듈 설계시 고유전율의 에폭시-세라믹 필름을 하였다. 본 모듈을 평가한 결과 기존 캐패시터 모듈에 비하여 2/3 크기의 소형화를 얻을 수 있었으며 ripple 전류 및 발열 특성이 매우 우수함을 확인하였다.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.2 s.54
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• pp.22-31
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• 2005

최근 무선통신 시스템의 소형화로 인해 안테나의 소형화가 요구되고 있다. 안테나의 소형화 방법에는 여러 가지가 있지만 이득과 효율을 고려할 때 고유전율의 유전체를 사용하기보다는 안테나 자체의 구조적 변형을 통해 안테나를 소형화하는 것이 더 효과적이다. 따라서, 본 논고에서는 마이크로스트립 안테나의 2차원 구조 변형과 3차원으로 화장된 구조변형에 의한 안테나의 소형화 방법에 대한 연구 결과에 대해 기술하였다. 2차적 구조 변형 방법에는 패치를 구부리거나 slit을 넣는 방법을 사용하여 그 크기를 축소시켰으나 소형화에 한계가 있었다. 그래서, 마이크로스트립 안테나의 패치와 접지면 사이의 공간을 활용하는 perturbation 효과를 바탕으로 3차원의 corrugation, iris, folded 구조를 이용하여 더욱 소형화된 안테나를 설계하였다. 또한, 2차원 구조의 소형화 방법에 3차원으로 확장한 구조를 서로 결합하여 안테나를 더욱 소형화 할 수 있었다. 이에 마이크로스트립 안테나의 소형화 방법과 그에 따라 설계·제작한 안테나에 대해 소개하고자 한다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.559-562
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• 2000

In this paper, coplanar waveguide fed antennas (CPWFAs) insetting two slits to boundary of the square microstrip patch are presented. These slits play roles in not only lowering a resonant frequency but also fine-tuning for the proposed antenna together with open stub of CPW feed line. The CPWFAs were designed and manufactured using microwave dielectrics (Al,Mg)TaO$_2$ having high dielectric-constant ($\varepsilon$r=20). The return loss and input impedance of the CPWFAs were investigated in terms of the slit length and open stub length of CPW feed line. It is shown that a resonant frequency decreases as the slit length increases.

• Electronics and Telecommunications Trends
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• v.26 no.5
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• pp.55-65
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• 2011

요즘 신산업으로 떠오르고 있는 개인 유전체 분석이나 차세대 시퀀싱 기술과 같은 고성능 컴퓨팅 응용들은 data-intensive한 작업들을 요구하며, 이러한 응용을 지원하기 위한 고성능 파일 시스템 기술에 대한 연구들이 다수 진행 중이다. 그러나 그 결과물들은 업체별로 보유한 고유 기술로서, 상호 호환성 등의 문제로 인해 표준화의 필요성이 제기되어 왔다. 현재 파일 시스템과 관련하여 거의 모든 IT 업체에서 사용하고 있는 실질적인 표준은 NFS(Network File System)이다. IETF(Internet Engineering Task Force)에서는 이러한 요구사항들을 반영하여 2010년에 NFSv4.1 표준을 공표하였고, 특히 I/O 성능을 향상시키기 위한 pNFS(parallel NFS)는 NFSv4.1의 핵심 기능으로서 다수업체들과 연구기관들에서 많은 관심을 받고 있다. 본 고에서는 pNFS 표준화 및 연구개발 동향과 관련된 이슈들에 대해 기술하고자 한다.

• Journal of KIISE:Databases
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• v.31 no.4
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• pp.432-443
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• 2004

As the XML data has been widely used in the Internet, it is necessary to store and retrieve the XML data by using DBMSs. However, relational DBMSs suffer from the model difference between graph structure of the XML data and table forms in relational databases. We propose an ORDBMS-based DTD-dependent XML data management system Xing. Xing stores XML data in a DTD-dependent form in an object database. Since the object database schema has a graph structure and supports multi-valued attributes, mapping from an XML data model and queries into an object data model and OQLs is a simple problem. For rapid storing of large quantities of the XML data, we use SAX parser with customized Xing-tree which requires a small memory space compared with the DOM-tree. Xing also returns the query result in an XML document form. We have implemented the Xing system on top of UniSQL object-relational DBMS for the validity checking and performance comparison. For XML genome data from GenBank, and experimental evaluation shows that Xing can provide significant performance improvement (maximum 10 times) compared with the relational approach.

• Journal of Life Science
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• v.29 no.9
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• pp.1047-1054
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• 2019

Transposable elements (TEs) occupy approximately 45% of the human genome and can enter functional genes randomly. During evolutionary radiation, multiple copies of TEs are produced by duplication events. Those elements contribute to biodiversity and phylogenomics. Most of them are controlled by epigenetic regulation, such as methylation or acetylation. Every species contains their own specific mobile elements, and they are divided into DNA transposons and retrotransposons. Retrotransposons can be divided by the presence of a long terminal repeat (LTR). They show various biological functions, such as promoter, enhancer, exonization, rearrangement, and alternative splicing. Also, they are strongly implicated to genomic instability, causing various diseases. Therefore, they could be used as biomarkers for the diagnosis and prognosis of diseases such as cancers. Recently, it was found that TEs could produce miRNAs, which play roles in gene inhibition through mRNA cleavage or translational repression, binding seed regions of target genes. Studies of TE-derived miRNAs offer a potential for the expression of functional genes. Comparative analyses of different types of miRNAs in various species and tissues could be of interest in the fields of evolution and phylogeny. Those events allow us to understand the importance of TEs in relation to biological roles and various diseases.