• Title/Summary/Keyword: RCS Pattern

Search Result 35, Processing Time 0.02 seconds

OCEAN WAVE IMAGING MECHANISMS BY AIRBORNE SAR: Pi-SAR X-BAND (Pi-SAR X-BAND 영상에 의한 파랑 이미징 메커니즘 연구)

  • Yang, Chan-Su
    • Proceedings of the KSRS Conference
    • /
    • 2008.03a
    • /
    • pp.176-179
    • /
    • 2008
  • In the present article, wave imaging mechanisms were investigated using airborne Pi-SAR (Polarimetric-Interferometric SAR) X-band VV images of ocean waves around the Miyake Island at approximately 180 km south from Tokyo, Japan. Two images of a same scene were produced at approximately 20 min. interval from two directions at right angles. One image shows dominant range travelling waves, but the other image shows a different wave pattern. This difference can be caused by the different image modulations of RCS and velocity bunching. In this study, 18 subimages are extracted, and the directional wave spectra are compared to each other of the two different areas.

  • PDF

Optimal Design of Torque Motor using an Improved Niching Genetic Algorithm (개선된 니칭 유전 알고리즘을 이용한 토크모터의 최적설계)

  • Kim, Jae-Kwang;Cho, Dong-Hyeok;Jung, Hyun-Kyo;Lee, Cheol-Gyun
    • The Transactions of the Korean Institute of Electrical Engineers B
    • /
    • v.50 no.7
    • /
    • pp.323-330
    • /
    • 2001
  • Niching method enables the genetic algorithm(GA) to be applied to the problems that require the location of multiple solutions in the search space, but these methods have fatal disadvantages. The main disadvantage is that the method requires too much calculation of object function. In this paper, a niching method using restricted competition selection(RCS) combined with a pattern search method(PSM) is proposed to identify multiple niches more efficiently and fast in a multimodal domain. The validity of the proposed method is verified by the simulation of test functions and the optimal design of an torque motor.

  • PDF

Quality Assay of Human Fetal-Cord Serum for Human IVF-ET with Mouse 2-Cell Embryos (생쥐 2-세포배아에 의한 시험관아기 배양용 대아제대혈청의 절적평가에 관한 연구)

  • Moon, S.Y.;Shin, C.J.;Chung, K.M.;Oh, S.K.;Pang, M.G.;Chang, Y.S.
    • Clinical and Experimental Reproductive Medicine
    • /
    • v.16 no.2
    • /
    • pp.139-146
    • /
    • 1989
  • The purpose of this study was to examine the qualitative variation of human fetal-cord sera (HCS) and to accept the sera in human lVF-ET program. One hundred and sixteenth RCS were tested with 1772 2-cell embryos of F1 (C57BL x CBA) virgin mice, Ten to sixteenth embryos were cultured in m-KRB medium with a aliquot of each serum (10%, v/v) or with bovine serum albumin(O.4%, w/v) as a control medium. Embryonic development were recorded at every 24hr for 4 days by such events as cellular compaction, cavitation, and hatching. In the control groups of eight assays, 98.1%(106/ 108) of 2-ce1l embryos developed above expanded blastocyst and the embryonic development was unified through the tests. But the developmental pattern in medium with each serum was various. Namely, the sera that supported development of 100% 2-cell embryos to above morula, early blastocyst, expanded blastocyst and hatching blastocyst was 45,7%(53/116) , 35.3%(41/116), 15.5%08/116.) and 6.9-%(8/116), respectively. And the sera that supported development of above 80% 2-cell embryos to the each embryonic stage was 92.2% (107/116), 83.6%(97/116), 63.8%(74/116) and 36.2%(42/116), respectively. Meanwhile two kinds of toxic pattern to the embryonic development were observed in some sera. The first pattern is that some sera arrested development of most embryos in pre- or post-stage of morula or blastocyst. The second pattern is that some sera promoted or arrested a part of embryos in the same dish. The ability of serum was depended on the batch of serum. Finally we could accept 69%(80/116) of the tested sera for human IVF-ET program. The base line for acceptance was the ability that supported above 80% 2-ce1l embryos to blastocyst. But some deterious sera were contained in this range. We cut off about 10% of the sera (83.6% , 97/116) that passed the baseline. This final percent of sera was similar to that of grade N of this study.

  • PDF

A Broad-Band Metamaterial Absorber Using Flexible Substrate (유연성 기판을 사용한 광대역 메타 흡수체)

  • Lee, Hong-Min
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.25 no.3
    • /
    • pp.339-347
    • /
    • 2014
  • In this paper, the authors present a new design for a broad-band metamaterial(MTM) absorber that utilizes flexible substrate. The proposed MTM unit cell is constructed by a electric-inducive-capacitive(ELC) resonator and a cut-wire on the same side of the flexible polyimide substrate. To reduce the radar cross section at frequencies other than the targeted frequency bands, the metallic pattern layer of the proposed structure is placed facing toward the incident wave propagation direction. A prototype absorber was fabricated with a planar array of $33{\times}45$ unit cells. Our experiments showed that the proposed absorber exhibits a peak absorption rate of 92 % and 93 % at 9.06 GHz and 15.0 GHz, respectively, and 75 % of the full-width at half-maximum(FWHM) bandwidth is achieved. The proposed backplane-less MTM structure can be used for a broad-band microwave absorber and irregular surface applications.

IMMUNOHISTOCHEMICAL STUDY ON THE EXPRESSION OF c-erbB-2 ONCOPROTEIN IN THE ODONTOGENIC CYSTS (치성낭에서 c-erbB-2 종양 단백의 발현에 관한 면역조직화학적 연구)

  • Pyo, Sung-Woon;Kim, Chang-Hyen;Lee, Won;Kim, Young-Sil
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • v.27 no.1
    • /
    • pp.32-36
    • /
    • 2001
  • To investigate epithelial cell proliferation reactivity in the odontogenic cysts, the expression of c-erbB-2 oncoprotein by epithelial lining was studied in odontogenic keratocyst(OKC, n=10), dentigerous cyst(DC, n=12), radicular cyst(RC, n=12) and normal dental follicle(n=7). The c-erbB-2 immunoreactivity was studied using a streptavidine- biotin- peroxidase method with polyclonal rabbit antihuman antibody to c-erbB-2 oncoprotein which is known to react with formalin fixed, paraffin-embedded sections and the intensity of staining was determined by manually. In all of 10(100%) OKCs, showed positive expression for c-erbB-2 oncoprotein compared with 10/12(83.3%) in DCs, 11/12(91.7%) in RCs and 5/7(71.4%) in normal dental follicles. The expression within OKC was higher than that of DC, RC and dental follicle but statistically not significant(p>0.05) and but may reflects underlying genetic defect. These results demonstrate differences in c-erbB-2 expression between the epithelial linings of the three major odontogenic cyst types, indicating differences in proliferation activity and differentiation processes within these lesions. And, in particular, these results are able to explain the peculiar aggressive growth pattern of OKC.

  • PDF