GaN 고출력 증폭기의 초소형 레이다 적용에 관한 연구

이상엽,이재웅,Lee, Sang_yeop,Yi, Jaewoong 한국군사과학기술학회 2016 한국군사과학기술학회지 Vol.19 No.5

Trend on high-power GaN(Gallium Nitride) SSPA(Solid-State Power Amplifier) and its availability in miniature radar systems are presented. There are numerous studies on high-power GaN devices since they have some characteristics of high-breakdown voltage, high power density, and high-temperature stability. Recent scaled GaN technology makes it possible to apply it in SSPAs for W- and G-band applications, with increasing its maximum frequency. In addition, it leads to downsizing and power-efficiency improvement of SSPAs, which means that GaN SSPAs can be available in miniature radar systems. This study also shows radar performance and comparison in the case of using such SSPAs at three frequency bands of Ku, Ka, and W. Finally, we demonstrate prospects of scaled GaN SSPAs in future miniature radar systems.

작은 직경 임플란트를 이용한 임플란트 지지 피개의치에 대한 환자 만족도 조사

이상엽,최대균,백장현,권긍록,Lee, Sang-Yeup,Choi, Dae-Gyun,Paek, Jang-Hyun,Kwon, Kung-Rock 대한치과보철학회 2011 대한치과보철학회지 Vol.49 No.1

연구 목적: 양악 총의치를 사용 중인 환자를 대상으로 하악에 4개의 작은 직경의 임플란트를 식립하여 implant supported overdenture로 전환 시 환자의 만족도 (저작, 유지, 발음, 심미, 사회적 문제, 심리적 문제)를 평가하였다. 연구 재료 및 방법: 60세 이상의 완전 무치악 환자 중 상하악 총의치를 장착한 환자를 대상으로 하였다. 수술 전에 진단 스텐트를 이용한 방사선 사진 (CT, panorama) 촬영을 시행하고 현재 사용하고 있는 의치에 대한 만족도에 대해 조사하였다. 그 후 하악 이공 전방부에 4개의 mini dental implant 식립 및 immediate loading 후 방사선 사진 촬영을 하였다. 식립 1달 후와 3달 후에 방사선 사진을 촬영하였으며 수술 전과 동일한 설문지를 통한 overdenture 사용 시 만족도 조사하였다. 결과: 현재 9명의 환자를 대상으로 시행하였다. 1. 총 36개의 임플란트를 식립하였으며 이중 1개의 임플란트가 실패하여 97.2%의 생존률을 보였다. 2. 임플란트 식립 전, 후 만족도 비교는 oral health impact profile 49를 이용한 설문 조사를 통해 이루어 졌다. 저작 시 불편감, 유지, 발음, 심미, 사회적 활동시 불편감, 심리적 불편감 등으로 비교 분석하였으며 5점 기준으로 불편감이 심할 수록 낮은 점수를 부여하였다. 그 결과 전반적으로 만족도가 상승하였다. 그 중 유지력 면에서 가장 크게 만족도가 상승하였으며 사회활동시 불편감, 심리적 불편감, 저작시 불편감, 심미, 발음 순으로 개선되었다. 결론: 이번 연구를 통하여 mini dental implant를 이용한 의치를 사용시 환자의 만족도가 높아진 것을 볼 수 있었다. 추 후 좀 더 많은 환자를 통해 장기간 연구를 할 예정이며 추가적인 방사선 사진을 촬영하여 임플란트 주위 골 소실 여부를 관찰할 예정이다. Purpose: In cases when implant supported overdenture is made by using standard size implant, additional procedure such as bone surgery and bone grafting can be required. And it gives burden to doctor and patient in terms of cost. Therefore, it is necessary to find the implant therapy for the edentulous patients in making denture with accordable cost and simple procedure. Materials and methods: Edentulous patients with upper and lower dentures participated in this study. Before the operation, survey about patient's satisfaction to the existing dentures was carried out. Surgical procedures included four small diameter implants installation anterior area and immediate loading. One and three month after the procedure, the same survey about patient's satisfaction was carried out, and radiography was taken. Results: We are doing research to the nine patients. Survival rate is 97.2 percent. The comparison of patient's satisfaction before and after surgery is performed based on oral health impact profile 49. We analyze mainly with masticatory discomfort, retention, aesthetics, social problem, psychological discomfort problems. As a result, satisfaction level is increased at all factors. Retention is the most increased satisfactory factor followed by mastication difficulty, pronunciation, psychological discomfort, social discomfort, aesthetics in order. Marginal bone loss is 0.21 mm at 12 weeks after implant placement. Conclusion: This research reveals that the denture supported by mini dental implant increases patient's satisfaction. This study will be continued with more patients for a long time and we are scheduled for taking additional radiography to check whether peri-implant bone resorption occurs or not.

Systems-Level Analysis of Genome-Scale In Silico Metabolic Models Using MetaFluxNet

이상엽,Han Min Woo,Dong-Yup Lee,Hyung Seok Choi,Tae Yong Kim,윤홍석 한국생물공학회 2005 Biotechnology and Bioprocess Engineering Vol.10 No.5

The systems-level analysis of microbes with myriad of heterologous data generated by omics technologies has been applied to improve our understanding of cellular function and physiology and con-sequently to enhance production of various bioproducts. At the heart of this revolution resides in silico genome-scale metabolic model. In order to fully exploit the power of genome-scale model, a systematic approach employing user-friendly software is required. Metabolic flux analysis of genome-scale meta-bolic network is becoming widely employed to quantify the flux distribution and validate model-driven hypotheses. Here we describe the development of an upgraded MetaFluxNet which allows (1) construc-tion of metabolic models connected to metabolic databases, (2) calculation of fluxes by metabolic flux analysis, (3) comparative flux analysis with flux-profile visualization, (4) the use of metabolic flux analy-sis markup language to enable models to be exchanged efficiently, and (5) the exporting of data from con-straints-based flux analysis into various formats. MetaFluxNet also allows cellular physiology to be pre-dicted and strategies for strain improvement to be developed from genome-based information on flux dis-tributions. This integrated software environment promises to enhance our understanding on metabolic network at a whole organism level and to establish novel strategies for improving the properties of organ-isms for various biotechnological applications.

두개골 봉합부의 초기 형태발생과정에서 Msx 유전자들의 발현양상

이상엽,박미현,유현모,남순현,김영진,김현정,Lee, Sang-Youp,Park, Mi-Hyun,Ryoo, Hyun-Mo,Nam, Soon-Hyeun,Kim, Young-Jin,Kim, Hyun-Jung 대한소아치과학회 2003 大韓小兒齒科學會誌 Vol.30 No.1

두개골의 성장은 뇌의 발달과 밀접하게 연관되어 있으며, 두개봉합부 주위 여러 조직들사이의 조화로운 상호작용을 필요로 한다. 두개골의 조기융합으로 알려진 craniosynostosis는 이러한 상호작용의 불균형으로 인해 야기될 수 있으며, craniosynostosis의 원인 유전자의 하나로 Msx2가 알려져 있다. Msx1, Msx2, Msx3로 구성되어 있는 Msx 유전자는 homeobox를 포함하고 있는 전사조절인자로, 초파리의 muscle segment homeobox 유전자의 homologue이다. Msx1과 Msx2 유전자들은 척추동물의 발생과정에서 조직 상호작용하는 여러 부위에 서로 겹치는 양상으로 발현되며 기관형성동안 상피-간엽조직 상호작용과 연관되어 나타나고, BMP와 FGF signaling의 표적 유전자들이다. Mouse 두개골의 시상봉합부와 관상봉합부의 초기 형태발생과정에서의 Msx 유전자들의 기능을 알아보기위해, 태생 15일에서 태생 18일까지의 mouse의 두개골을 이용하여 in vivo 실험을, 태생 15.5일 mouse 두개골을 이용하여 in vitro 실험을 시행하였다. 시상두개봉합부에서는, Msx1은 봉합부의 간엽조직과 dura mater에 발현하였으며 Msx2는 두개봉합부와 dura mater에 강하게 발현되었다. 관상두개봉합부에서는 Msx1, Msx2 유전자 모두 강하게 발현되었으며, 골막에서도 관찰할 수 있었고, Msx1이 Msx2보다 좀더 광범위하게 발현되었다. In vitro 실험결과, BMP2 bead 주위로 Msx1 mRNA와 Msx2 mRNA 모두 발현되었으나, FGF2 bead 주위로는 Msx1만 발현되고 Msx2는 관찰되지 않았다. 이 결과들을 종합해 볼 때, Msx1, Msx2 유전자들은 태생기 두개봉합부의 형태발생 및 유지를 조절하는데 중요하며, Msx 유전자들은 거의 유사한 발현양상을 나타내고 있으나 이들 유전자들을 조절하는 상위 siganling에 의해 서로 보완적으로 혹은 독립적으로 기능을 나타내고 있음을 시사해 주고 있다. The development of calvarial bones is tighly co-ordinated with the growth of the brain and needs of harmonious interactions between different tissues within the calvarial sutures. Premature fusion of cranial sutures, known as craniosynostosis, presumably involves disturbance of these interactions. Mutations in the homeobox-containg gene Msx2 cause human craniosynostosis syndrome. Msx genes, which are consist of Msx1, Msx2 and Msx3, are homeobox-containg transcripton factors, and were originally identified as homologue of Drosophila msh(muscle segment homeobox) gene. Msx1 and Msx2 genes, expressed mostly in overlapping patterns at multiple site of tissue interactions during vertebrate development, are associated with epithelial-mesenchymal interactions during organogenesis, targets of BMP and FGF signaling. To elucidate the function of Msx genes in the early morphogenesis of mouse cranial suture, we analyzed the expression of them by in situ hybridization during embryonic(E15-E18) stage, and did vivo experiments in E15.5 mouse using rhBMP-2, rhFGF-2 protein soaked bead. In the sagittal suture, Msx1 was expressed in the mesenchyme of suture and the dura mater, Msx2 was intensely expressed in the sutural mesenchyme and the dura mater. In the coronal suture both of Msx genes were expressed intensely in the sutural mesenchyme and expressed in the periosteum also. Msx1 had a broader expression pattern than Msx2. BMP2 beads induced expression of both Msx1 and Msx2, FGF2 beads induced expression of Msx1, but not Msx2. Taken together, these data suggest that Msx1 and Msx2 genes have important role in regulating the morphogenesis and maintenance of embryonic cranial suture. Both of Msx genes are expressed similarly but because of their upstream signaling, they function dependently or cooperatively according to change of signaling molecule.

학술발표회 초록 : ( 생물화공 (2) ) ; 아미노산을 소량 첨가한 최소 배지에서의 PHB 생산을 위한 재조합 대장균의 유가식 배양

이상엽,이영,장호남 ( Sang Yop Lee,Young Lee,Ho Nam Chang ) 한국화학공학회 1994 추계학술발표회 Vol.- No.-

단안상전장애에 동반된 눈꺼풀처짐에서 눈꺼풀올림근을 이용한 이마근걸이술 1예

이상엽,김혜영,Sang Yeop Lee,Hye Young Kim 대한안과학회 2010 대한안과학회지 Vol.51 No.2

Purpose: For the correction of ptosis in monocular elevation deficiency (MED) patients, levator resection or frontalis sling operation with various materials has been used. The authors present a case of a monocular elevation deficiency patient who was treated for ptosis using the levator muscle as a frontalis sling. Case summary: A six-year-old male patient with left monocular elevation deficiency underwent a frontalis sling operation using a levator muscle. The patient had received left inferior rectus recession, left medial rectus resection and left lateral rectus recession with transposition. An upper eyelid skin crease incision was made, and the anterior surface of the levator muscle was exposed as far as the Whitnall ligament. A levator muscle flap was then formed from aponeurosis by incising the full width of the levator horizontally, just below the Whitnall ligament and anchored to the frontalis muscle. The surgical result was satisfactory as the preoperative MRD1 was 0.5 mm and the postoperative MRD1 was 2.5 mm. There were no complications such as keratitis or wound problems. Conclusions: The levator muscle flap can be an effective frontalis suspension material to correct ptosis in an MED patient with poor levator function. J Korean Ophthalmol Soc 2010;51(2):282-285

미국의 과학기술 정책동향

이상엽,박지홍,이용태,Lee, Sang-Yeop,Park, Ji-Hong,Lee, Yong-Tae 재료연구소 1997 機械와 材料 Vol.9 No.3

중복기생균 Ampelomices quisqualis 94013의 배양적 특성

이상엽,류재당,김홍기,Lee, Sang-Yeob,Ryu, Jae-Dang,Kim, Hong-Gi 한국식물병리학회 2005 식물병연구 Vol.11 No.2

Ampelomyces quisqualis 94013는 중복기생균으로 흰가루병 생물적 방제용 우수균주로 선발하여, 이 균의 효율적 이용을 위한 배양적 특성을 조사하였다. A. quisqualis 94013의 균사생육 적은은 $26^{\circ}C$이였으며, 균사생육 최적 pH는 6.5였다. 감자한천배지(PDA)배양시 광조건(형광등 12시간주기)보다는 암조건에서 더 많은 포자를 형성하였다. 이 균의 포자발아 온도범위는 $10\~35^{\circ}C$이고, 최적온도는 $20^{\circ}C$이였다. 포자발아는 $24^{\circ}C$에서 8시간 배양 후 시작되었으며, 포자발아율은 포자현탁액의 농도가 $5{\times}10^7/ml$보다 $5{\times}10^5/ml$나 $5{\times}10^6/ml$에서 높았다. 이 균은 탄소원으로는 dextrin을, 질소원으로는 neopepton을 가장 잘 이용하였다. Ampelomyces quisqualis 94013 (AQ94013), a hyperparasite, was selected as an effective biological control agent against cucumber powdery mildew. Optimal temperature for mycelial growth of AQ94013 was $26^{\circ}C$, and the optimal pH was 6.5. Conidia of AQ94013 were more Produced on potato dextrose agar (PDA) in darkness than under alternating cycles of 12 hr fluorescent light and 12 hr darkness. Temperature range for spore germination of the fungus was $10\~35^{\circ}C$, and optimal temperature was $20^{\circ}C$. Conidial germination of the fungus began 8 hr after incubation at $24^{\circ}C$. Germination rate of conidia at concentration of $5{\times}10^5\;spores/ml\;and\;5{\times}10^6\;spores/ml$ was higher than at concentration of $5{\times}10^7\;spores/ml$. The best source of carbon and nitrogen for mycelial growth of the fungus were dextrin and neopeptone, respectively.

Fractional Diffusion Equation Approach to the Anomalous Diffusion on Fractal Lattices

이상엽,Jinuk Lee,Dann Huh 대한화학회 2005 Bulletin of the Korean Chemical Society Vol.26 No.11

A generalized fractional diffusion equation (FDE) is presented, which describes the time-evolution of the spatial distribution of a particle performing continuous time random walk (CTRW) on a fractal lattice. For a case corresponding to the CTRW with waiting time distribution that behaves as  (t) ~ t(+1), the FDE is solved to give analytic expressions for the Green’s function and the mean squared displacement (MSD). In agreement with the previous work of Blumen et al. [Phys. Rev. Lett. 1984, 53, 1301], the time-dependence of MSD is found to be given as < r2(t)> ~ t 2 /dw, where dw is the walk dimension of the given fractal. A Monte-Carlo simulation is also performed to evaluate the range of applicability of the proposed FDE.

작물별 주요 병해 - 상추

이상엽,Lee, Sang-Yeop 한국작물보호협회 2009 자연과 농업 Vol.30 No.1