• Title/Summary/Keyword: retro

Search Result 320, Processing Time 0.02 seconds

A Retro-Directive Array System for Reduction of Electromagnetic Wave Reflection (전자기파 반사 감소를 위한 역지향 배열 안테나 시스템)

  • Ha, Jungje;Jang, Sunghoon;Lee, Yongshik
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.26 no.1
    • /
    • pp.113-118
    • /
    • 2015
  • In this paper, a cancellation technique for electromagnetic waves is realized based on a retrodirective antenna array system. The system re-transmits a signal to the direction of the incoming signal, with the same frequency and opposite phase. For the experimental verification, a $2{\times}2$ retrodirective array system is designed and fabricated. Experimental results for a metallic cylinder show as much as 26-dB reduction in reflection.

An Analysis of the Fashion Trends in Korea over the Last 10 years(1996-2005) (최근 10년(1996년$\sim$2005년) 간 국내 패션 트렌드의 경향 분석)

  • Ko, Eun-Ju;Lee, Jee-Hyun
    • Journal of the Korean Society of Costume
    • /
    • v.58 no.9
    • /
    • pp.18-28
    • /
    • 2008
  • The purpose of this study is to examine the Characteristics of Fashion Trends($1996{\sim}2005$) of Korea by the trend elements - style, fabric and color. The results of this study are as followed. During 10years, 'modern(18%)', 'elegant(11%)' and 'romantic(10%)' styles were shown in order, and colors of YR(17%), Y(14%), R(13%) and PB(11%) were shown in order. Considering tones, m(16%), d(12%), gy(11%) and s(10%) tones were in the order of frequency. In the fabric trend 'elegant(19%)', 'modern(14%)' and 'natural(14%)' images showed the high frequency. Since 2000's, style trends and fabric trends were subdivided, and the contrary images coexisted. The trend images of 'natural', 'retro', 'manish' and 'fun' were mainly used in fabric trend, and 'romantic' and 'classic' images were frequently used in style trend. The changes of trend images in style and fabric have been similar until the early 2000's but the cycle of trend of style became shorter than fabric trend. Therefore the cycle of fabric trend should be changed to be a short term and subdivided in company with style trend.

In Vivo Screening Method for the Anti-AIDS Drugs in the BALB/c Mice Inoculated by Anemia Strain of Friend Virus (Friend Anemia Virus에 감염된 BALB/c 생쥐를 이용한 항AIDS약물의 생체내 약효검색)

  • 안형수;염윤기;장영수
    • YAKHAK HOEJI
    • /
    • v.39 no.6
    • /
    • pp.622-630
    • /
    • 1995
  • Inoculation of Friend anemia virus, which was a Kind of retro virus such as HIV, results splenomegaly, anemia, the increase of WBC counts and reverse transcriptase activity in serum. These results were due to the inhibition of the differentiation of erythroid progenitor cell by the FVA at the spleen. Using these as index of antiviral effects, we pursued the establishment of in vivo screening method for the new anti-ADS drugs. Among zidovudine, didanosine and zalcitabine, which were already approved as anti-AIDS drugs, treatment of zidovudine for 18 days in BALB/c mice inoculated with Friend anemia virus resulted the most potent inhibitory effects on the splenomegaly, the increase of WBC counts and reverse transcriptase activity, but did not recovered the anemia due to the tomcity of zidovudhie itself on the bone marrow. The antiviral effects of zidovudine was reduced in case of zidovudine treatment 7 days after Friend anemia virus inoculation. These results suggested that the sooner treatment of zidovudine would be better improved when the virus was inoculated. Human recombinant interferon itself .alpha. did not showed the antiviral activity against Friend anemia virus and did not also affected the antiviral activity of zidovudine. These results suggested that Friend anemia virus would be used as a tool in vivo screening method for the Lobster of reverse transcriptase.

  • PDF

Design & Development of KSLV-II Ullage Motor (KSLV-II 가속모터 설계 및 개발)

  • Oh, Jisung;Lee, Gwan Joo;Kim, Sujeong;Kim, Hanjoon;Park, Euiyong;Kwon, Hyukho;Cho, In-Hyun
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2017.05a
    • /
    • pp.1122-1126
    • /
    • 2017
  • KSLV-II ullage motor is a type of the separation motor of Korea Space Launch Vehicle. Simultaneously operates with the retro Motor to perform the stage separation. The internal ballistics design, application of propellant composition, and the design of the combustion chamber and the canted nozzle were performed in accordance with the target performance of the ullage motor. Ti-6Al-4V alloy was applied to the combustion as material of chamber and nozzle. The heat resistant material of the nozzle was selected to ensure the heat resistance of the propellant containing a large amount of aluminum. And the combustion performance of the ullage motor satisfying the KSLV-II requirements was secured by performing the ground combustion test.

  • PDF

Retro- and Ante-grade Amnesia after Conscious Sedation using Midazolam (Midazolam을 이용한 의식하진정법을 시행한 환자에서 나타난 선행성 및 후행성 기억상실)

  • Kim, Yeong-Wook;Keum, Yoon-Seon;Mo, Dong-Yub;Lee, Jang-Yeol;Kim, Hyoun-Chull;Lee, Sang-Chul
    • Journal of The Korean Dental Society of Anesthesiology
    • /
    • v.11 no.2
    • /
    • pp.153-158
    • /
    • 2011
  • Midazolam is known to produce sedation as well as amnesia. Many articles reported about anterograde amnesia, but it is rare that articles about retrograde amnesia. The 61-year-old female patient (64 kg, 154 cm, ASA physical status I) was administered 3.02 mg (0.047 mg/kg) of midazolam during 2 hours. The patient's Modified Observer's Assesment of Alertness/Sedation Scale was 4. The patient who had been consciously sedated with midazolam, exhibited profound amnesia, both anterograde and retrograde after implantation. The patient's memory restoration was begun after 6 hours.

Atmospheric Profiles from KOMPSAT-5 Radio Occultation : A Simulation Study

  • Lee, Woo-Kyoung;Cho, Sung-Ki;Jo, Jung-Hyun;Park, Jong-Uk;Yoon, Jae-Cheol;Lee, Jin-Ho;Chun, Yong-Sik
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • v.2
    • /
    • pp.53-56
    • /
    • 2006
  • KOMPSAT (KOrea Multi-Purpose SATellite)-5 for the earth observation and scientific research is scheduled to launch in 2009. The second payload, AOPOD (Atmosphere Occultation and Precision Orbit Determination) system, consists of a space-borne dual frequency GPS receiver and a laser retro reflector. GPS radio occultations from AOPOD system can be used to generate profiles of refractivity, temperature, pressure and water vapor in the neutral atmosphere with a high vertical resolution. Also the radio occultation in the ionosphere provides an inexpensive tool of vertical electron density profile. Currently, many LEO missions with GPS radio occultation receivers are on orbit and more GPS occultation missions are planed to launch in the near future. In this paper, we simulated radio occultation measurements from KOMPSAT-5 and retrieved atmospheric profiles using the simulated data.

  • PDF

A Study on the Inhibitory Effects of Scutellariae Radix on Fat Accumulation (황금(黃芩, Scutellariae Radix)의 지방축적억제 효능연구)

  • Kim, Kyeong-Seon;Cha, Min-Ho;Lee, Soo-Won;Yoon, Yoo-Sik
    • Korean Journal of Oriental Medicine
    • /
    • v.9 no.2
    • /
    • pp.45-54
    • /
    • 2003
  • Obesity is caused by unbalance of energy intake and expenditure, which results in extra accumulation of adipose tissue. Obesity is directly related to metabolic diseases such as diabetes, hyperlipidemia, fatty liver and so on. To investigate the anti-obesity effects of Scutellariae Radix, 70% EtOH extract and water extract of it were tested by in vitro and in vivo studies of fat accumulation. 3T3-L1 preadipocyte cell line was used in a in vitro study of fat accumulation. After 3T3-L1 cells were induced to differentiate into adipocytes, S. radix extract were added and fat accumulation was measured by oil red O staining. In vivo study showed that weight and epididymal/ retro-peritoneal adipose tissues were significantly reduced in mice fed Scutellariae Radix extract compared with control group. Especially, mice fed Scutellariae Radix extract showed reduced serum triglyceride and glucose levels. When adipose tissues were analyzed by microscope, mean adipocyte size was significantly reduced in Scutellariae Radix extract-fed mice. Therefore, this study showed inhibitory effects of Scutellariae Radix on in vitro and in vivo fat accumulation.

  • PDF

An Analysis of the Female Golfers′ Preference of the Recent Sportswear Trend and a Suggestion of a Direction for Golfwear Design (최근 스포츠웨어 트렌드에 대한 소비자 선호도 분석과 이에 기초한 골프웨어 디자인 방향의 제시 -국내 20~30대 여성 골퍼를 대상으로-)

  • 이지은;이주현
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.26 no.8
    • /
    • pp.1254-1264
    • /
    • 2002
  • The purpose of this study was to suggest a direction for golfwear design targeting young female golfers, based on the analysis of their preference of recent sportswear trend. Total 197 respondents, female golfers, were sampled for data gathering, who were asked to answer to the self-report questionnaire with the stimuli of five trendy golfwear styles [i.e., representing recent sportswear trend]. In summary, the results of this study were as follows: 1) The female golfers showed significant difference in their preference of recent sportswear-trend sues, according to their age or marital status. 2) Among the five trendy styles, each of which corresponded to five themes in 2002 S/S sportswear trend, the style of "Retro Chic", a type of retrospective trend theme, was most favored. 3) The female golfers in their twenties residing in Kangnam, were found to have ① relatively higher fashion leadership, and ② higher preference of maximal and kitsch trends, when compared with the rest of the respondents. 4) The most influential design elements in each trendy style, dominating the golfers' preference, varied with the feature of trend themes. 5) Based on the analysis of the young female golfers′ preferences of recent sportswear trend, a direction for golfwear design were suggested.

Study of the Influence of Condensation on Road Signs to Drivers (결로 발생 도로표지가 운전자에게 미치는 영향에 관한 연구)

  • Park, Jae Hong;Yun, Duk Geun;Sung, Jung Gon;Kang, Weon Eui
    • International Journal of Highway Engineering
    • /
    • v.15 no.5
    • /
    • pp.187-193
    • /
    • 2013
  • PURPOSES : This research is to analyze the influence in terms of misreading rate and legibility time for drivers when condensation occurs on the road signs. METHODS : In this research, the dew occurred road signs provided to drivers to measure legibility time and misreading rate to compare with normal road sign. In order to identify the difference of legibility time between normal road sign and dew occurred road sign, the T-test and ANOVA test were used. And the vision system was used to recognize the region of dew occurrence on the road sign, then the brightness of dew occurrence region on the road sign was changed to check the misreading rate of drivers according to the change rate of brightness. RESULTS : The legibility times were measured 2.65s for normal road sign and 4.08s for dew occurrence road sign and misreading rates were measured 2.8% for normal road sign, 21.7% for dew occurrence road sign.

Characterization of Low Molecular Weight Polyphenols from Pine (Pinus radiata) Bark

  • Mun, Sung-Phil;Ku, Chang-Sub
    • Food Science and Biotechnology
    • /
    • v.15 no.3
    • /
    • pp.424-430
    • /
    • 2006
  • Low molecular weight polyphenols were isolated from hot water extracts of radiata pine (Pinus radiata) bark using a Sephadex LH-20 column and characterized by $^1H$ and $^{13}C$ NMR, UV, FT-IR, and GC-MS analyses. Major compounds isolated and identified were protocatechuic acid, trans-taxifolin, and quercetin. Trans-taxifolin, an important intermediate in biosynthetic route of proanthocyanidin (PA), was isolated in large quantities and indicates that PA is a major component of radiata pine bark. Small amounts of polyphenols were identified by GC-MS analysis. The presence of p-hydroxybenzoic acid, vanillic acid, protocatechuic acid, cis- and trans-feruic acid, p-coumaric acid, trans-caffeic acid, (-)-epicatechin, (+)-catechin, trans- and cis-taxifolin, (+)-gallocatechin, and quercetin was confirmed by comparison of mass fragmentation patterns and retention times (RT) with authentic samples. In addition, the presence of astringenin, astringenin glycoside, trans- and cis-leucodelphinidin was strongly assumed from characteristic mass fragment ions due to their conjugated structure and retro Diels-Alder reaction, and also from biosynthetic route of PA. GC-MS analysis allowed us to detect small amounts of phenolic acids and flavonoids and eventually discriminate trans- and cis-configuration in the identified polyphenols.