• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.169-174
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• 2005

In this paper, we proposed a new algorithm of the inverse scattering for the reconstruction of unknown dielectric scatterers using the finite-difference time-domain method and the design sensitivity analysis. We introduced the design sensitivity analysis based on the gradient for the fast convergence of the reconstruction. By introducing the adjoint variable method for the efficient calculation, we derived the adjoint variable equation. As an optimal algorithm we used the steepest descent method and reconstructed the dielectric targets using the iterative estimation. To verify our algorithm we will show the numerical examples for the two-dimensional $TM^2$ cases.

• Journal of KIISE
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• v.42 no.12
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• pp.1584-1589
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• 2015

With the advancement of next-generation sequencing (NGS) technologies, various genome browsers have been introduced. Because existing browsers focus on comparison of the genomic data of extant species, however, there is a need for a genome browser for ancestral genomes and their evolution. In this paper, we introduce a genome browser, AGB (Ancestral Genome Browser), that displays ancestral genome data reconstructed from existing species. With AGB, it is possible to trace genomic variations that occurred during evolution in a simple and intuitive way. We explain the capability of AGB in terms of visualizing ancestral genomic information and evolutionary genomic variations. AGB is now available at http://bioinfo.konkuk.ac.kr/genomebrowser/.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.12
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• pp.992-995
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• 2018

The wireless charging of body-embedded medical instruments and wireless power transfer to various inside dielectric-materials is still a future technology that has not yet been achieved. This paper proposes methods for controlling the capacitance of the resonators and installing air pockets on the top and bottom sides of the resonators for optimal design, which considered efficiency and resonant frequency in accordance with the electromagnetic characteristics of the dielectric medium. In future, the results of this research will be utilized as the basic research data to design and restore resonant frequency of resonators embedded in various dielectric environments.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.2 s.105
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• pp.158-164
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• 2006

In this paper, we proposed a new algorithm of the inverse scattering for the reconstruction of unknown dielectric scatterers using the finite-difference time-domain method and the design sensitivity analysis. We introduced the design sensitivity analysis based on the gradient information for the fast convergence of the reconstruction. By introducing the adjoint variable method for the efficient calculation, we derived the adjoint variable equation. As an optimal algorithm, we used the steepest descent method and reconstructed the dielectric targets using the iterative estimation. To verify our algorithm, we will show the numerical examples for the two-dimensional $TM^2$ cases.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.2 s.105
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• pp.171-177
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• 2006

A low-cost, high-performance 40 Gb/s clock recovery module using a phase-locked loop(PLL) for a 40 Gb/s optical receiver with the clock-hold function has been designed and implemented. It consists of a clock extractor circuit, an RF mixer and a frequency discriminator for phase/frequency detection, a VC-DRO, a phase shifter, and a clock-hold circuit. The extracted 40 GHz clock is synchronized with a stable 10 GHz VC-DRO. The clock stability and jitter characteristics of the implemented PLL-based clock recovery module are significantly improved as compared with those of the conventional open-loop type clock recovery module with a DR filter. The measured peak-to-peak RMS jitter is about 230 fs. When an input signal is dropped, the 40 GHz clock is maintained continuously by the hold circuit.

• Korean Journal of Ornithology
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• v.25 no.2
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• pp.77-81
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• 2018

The Korean Crested ibis Nipponia Nippon is an endangered species. A pair of Crested ibis was introduced from China in October 2008, and a successful program of artificial incubation of the species, and over 200 animals have been successfully bred through the restoration project up to 2017 at Upo ibis restoration center. We assessed genetic diversity and sex determination in the Korean Crested ibis. In total, 228 Crested ibis (115 females and 113 males) were identified. And genetic diversity measures, observed heterozygosity, expected heterozygosity, and polymorphic information content values were lower in 2017 than those in 2016. The inbreeding coefficient showed that the degree of ancestry increased in 2017. The decrease in polymorphism and increase in the degree of ancestry is thought to be due to inbreeding in such a small group. In this study provided important insight into protocols for genetic management of the breeding population of Korean Crested ibis in Korea and will help in extending the restoration program.

• Journal of Korea Society of Industrial Information Systems
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• v.6 no.4
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• pp.89-94
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• 2001

A new design method of the microwave multisection impedance transformer is proposed. This method is based on the inverse scattering theory using the frequency domain reflection coefficient of the transformer to be designed. In the first step, the permittivity profile of a virtual one-dimensional dielectric medium is reconstructed using the desired reflection coefficient. In the second step, the transformer which is equivalent to the reconstructed dielectric medium in view of reflection characteristics is synthesized. Theoretically, this method can be used to design the impedance matching transformers with arbitrary passband characteristics within the limit of the Bode-Fano criteria[1]. Our approach is examined for two design examples to show that it is valid.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.9-9
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• 2023

한국 특산 식물인 미선나무 (Abeliophyllum distichum)는 IUCN Red List의 EN (위기종) 등급에 지정되 어 보호받아 왔다. 미선나무는 국내 자생지 6곳을 포함하는 13개의 서식지에서 생육되고 있다고 알려져 있다. 2017년 이후, 국내에서는 지속적인 보전과 관리하에 법정보호종에서 해제되어 멸종위기종 복원 성 공 사례의 귀감이 되었으나 국내를 제외하면 미선나무의 활용은 아직 어려운 현실이다. 미선나무는 1속 1종이지만 종 내에서 다양성이 존재한다. 꽃의 형태적 특징에 따른 다양한 분류가 이루어지며, 옥황1호을 포함한 분홍, 상아, 연녹색, 흰색 등으로 구분된다. 유전체 연구 및 성분 분석을 통해, 각 표현형마다 유전 정보와 유효 성분의 차이가 존재한다는 것이 알려졌다. 활용 가치를 높이려면, 유전적으로 안정되고 표준화가 가능한 원료가 필요하며, 이는 신품종을 이용하거나 새로운 개발이 필요하다는 것을 내포한다. 일반 식품으로의 활용은 어려우나 기능성 화장품의 원료 등으로 활용되고 있으며, 이러한 활용들은 미선나무의 높은 활용 가치를 투영한다. 활용 가치 평가를 위해 수행된 DNA 손상, 멜라닌 생합성, 항염증, 항산화, 항암 억제 등의 연구를 통해 다양한 약리학적 효능을 가진다는 결과들이 도출되었고, 많은 문헌들이 그 근거를 뒷받침한다. 또한, 유효 성분의 합성경로를 재정립하고 RNA 분석을 통해 그 양상을 예측하기 위한 연구가 진행 중에 있다. 미선나무에서 유래한 식물조직 배양체인 callus의 유도 및 배양이 진행되고 있으며, 옥황1호 유래 callus를 활용하여 다양한 연구를 수행하고 있다. 앞서 언급한 미선나무 연구 및 개발에 대한 한계를 파악하고, 천연 식물 자원으로의 미선나무에 대한 지속적인 관심과 지원을 통해 나고야의정서에 대응하는 전략적 접근이 필요하다.

• Journal of Aquaculture
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• v.20 no.3
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• pp.184-189
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• 2007

Treatment conditions for the induced diploid gynogenesis, a maternal-exclusive form of artificial parthenogenetic reproduction, were optimized in bagrid catfish (Leiocassis ussuriensis, Siluriformes). Optimal amounts of ultraviolet (UV) irradiation for the genetic inactivation of spermatozoa in bagrid catfish and Pseudobagrus fulvidraco were proven to be ranged from 3,600 to 4,800 $ergs/mm^2$ based on the examination of viability of embryos and haploid incidence. Haploid embryos were restored to diploidy by preventing the extrusion of the second polar body using cold shock treatment. Thermal treatments (4 or $6^{\circ}C$ for 30, 40 or 50 min) were carried out 3, 5 or 7 min post insemination. Best scores for embryo viability (38.6% of total eggs taken) and incidence of normal diploidy (87.9% of hatched larvae) were observed at the embryo group treated at $4^{\circ}C$ for 40 min, 5 min after insemination. Restoration of gynogenetic diploidy was confirmed based on the absence of haploid syndrome, cell size and/or nucleolar organizing region (NOR) counts.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.3
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• pp.219-232
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• 2013

This paper presents a microstrip antenna which recovers its resonant frequency and impedance shifted automatically by the approach of other objects such as hands. This can be used for telemetry sensor applications in the ultrahigh frequency(UHF) industrial, scientific, and medical(ISM) band. It is the key element that an frequency-reconfigurable antenna could be electrically controlled. This antenna is miniaturized by loading the folded plates at both radiating edges, and varactor diodes are installed between the radiating edges and the ground plane to control the resonant frequency by adjusting the DC bias asymmetrically. Using this voltage-controlled antenna and the micro controller peripheral circuits of reading the returned level, the antenna is designed and fabricated which recovers its resonant frequency and impedance automatically. Designed frequency auto recovering antenna is conformed to be recovered within a few seconds when the resonant frequency and impedance are shifted by the approach of other objects such as hand, metal plate, dielectric and so on.