RISS 학술연구정보서비스

검색
다국어 입력

http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.

변환된 중국어를 복사하여 사용하시면 됩니다.

예시)
  • 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
  • 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
닫기
    인기검색어 순위 펼치기

    RISS 인기검색어

      검색결과 좁혀 보기

      선택해제
      • 좁혀본 항목 보기순서

        • 원문유무
        • 음성지원유무
        • 원문제공처
          펼치기
        • 등재정보
          펼치기
        • 학술지명
          펼치기
        • 주제분류
          펼치기
        • 발행연도
          펼치기
        • 작성언어
        • 저자
          펼치기

      오늘 본 자료

      • 오늘 본 자료가 없습니다.
      더보기
      • 무료
      • 기관 내 무료
      • 유료
      • 이중공진 이중편파 마이크로스트립 안테나

        김연정,윤완석,윤영중 延世大學校 電波通信共同硏究所 1999 電波通信論文誌 Vol.4 No.1

        본 논문에서는 Ku-band 위성통신 송수신 겸용 안테나를 위해서 500 ㎒이상의 대역폭과 송·수신부가 서로 다른 선형편파를 가지는 이중급전 구조의 이중공진 안테나를 연구하였다. 이때 상대 급전선에 의한 임피던스의 변화를 최소화시켜 최적의 안테나를 설계하였으며, 배열 안테나로 확장시 이중급전 구조의 문제점인 공간상의 문제를 해결하기 위해서 마이크로스트립 선로와 via-hole 혼합급전 방식을 사용하였다. 제안된 안테나를 이차원의 2X2 배열 마이크로스트립 안테나로 설계 및 제작하였고, 방사패턴과 주파수특성을 측정하여 위성통신 송수신 겸용 안테나로 잘 동작할 수 있음을 확인하였다. In this paper, to transmit and receive the differently polarized signals simultaneously with a single antenna system, the dual-frequency microstrip array antenna with dual-polarization is proposed and designed. This antenna operates simultaneously at 14.25 ㎓ and 12.50 ㎓ with the bandwidth above 500㎒. To extend to two dimensional array, microstrip feed line and coaxial probe through via-hole are used.

      • 고등학교 화학 Ⅱ 교과서 내용의 인지요구도 수준 분석 및 활용 방안

        박숙연 이화여자대학교 교육대학원 1998 이화교육논총 Vol.9 No.-

        The purpose of this study is to investigate the cognitive demands required for understanding contents in the high school chemistry Ⅱ textbooks and the levels of cognitive development stages of 2nd grade general high school students in science major. The demanded cognitive levels of 86 topics involved in chemistry contents were analyzed based upon CAT(Curriculum Analysis Taxonomy) Ⅰ,Ⅱ,Ⅲ from CSMS(Concept in Secondary Mathematics and Science) program in the Great Britain. The levels of cognitive development stages of 2nd grade general high school students in science major were analyzed using GALT Short Version test. Then comparative study between the demanded cognitive levels of those students has been used to develope more effective science class strategy. The results of the study are summarized as follows. First, most of the 86 chemistry topics required late formal operational satge. Secondly, 6.2% of students were at the concrete operational stage and 33.5% of students were at the transitional stage. The rest of them were at the formal operational stage. Finally, a calss strategy of vapor pressure based upon the results of this study has been developed to show methods and processes in detail. Also, three suggestions are made to science teachers in high school. First, it is needed to know the levels of cognitive development and formal reasoning ability of their own students. Secondly, the instructional strategy should be matched with the levels of cognitive development and formal reasoning ability of students. Finally, the method and the results of this study will be helpful for improving the instructional strategy matching cognitive domain of students.

      • KCI등재

        대형 화재로 인한 사상자의 손상 유형과 합병증 : 동인천 라이브호프 화재를 중심으로

        신중호,김재광,염석란,신종환,민순식,임용수,양혁준,이근,황성연 대한응급의학회 2001 대한응급의학회지 Vol.12 No.3

        Background: High risks of fire alway exist for buildings in urban areas, especially those in downtown. Crowds, as well as more complex and larger structures, may cause more victims in the event of fire; therefore, emergency medical service plans must be established for such disastrous events. Methods: On the evening of October 30,1999, a fire broke out in downtown, Dong-Incheon Live-Hof restaurant; 56 people were killed and 76 were injured. Most of them were teenagers. We retrospectively reviewed the medical records of the victims, Results: 1) Among the 56 dead, 54 died from smoke inhalation, one from extensive burns, and one from sepsis during treatment. 2) Among the 76 injured, 70 patients suffered from smoke inhalation, 53 from burns, and 9 from several types of trauma (sprains, contusions, lacerations, abrasions, fractures, etc.). 3) Later complications were laryngeal edema, pulmonary edema, scar contracture, and hypoxic brain damage, and so forth. 4) Post traumatic stress syndrome was unexpectedly more prevalent in mildly to moderately injured survivors and witnesses than in seriously injured survivors. Conclusion: Many complications exist after a fire. Some may be resolved in time, but others may result in permanent sequelae. Early rescue, early triage, and early management during transport by emergency medical service (EMS) personnel can result in fewer complications and a lower mortality rate. Therefore, we propose the establishment of plans to be followed during various major disasters.

      • 재생골재 콘크리트의 수축균열 특성에 관한 연구

        구봉근,라재웅,이재범,류연종,이현석 충북대학교 건설기술연구소 2003 建設技術論文集 Vol.22 No.2

        As concrete is prevented from shrinking freely, tensile stresses develop which frequently result in cracking. Cracks in reinforced concrete structures reduce overall durability by allowing the penetration of water and aggressive agents, thereby accelerating the deterioration of the reinforcing steel. Highway pavement, bridge decks, and industrial floors are especially susceptible to this type of deterioration since these structures exhibit high rates of shrinkage and are frequently exposed to aggressive environmental conditions. The objectives of this investigation included the implement of experimental procedures for assessing shrinkage cracking behavior on recycled aggregate concrete, the selection of replacement rate and mix composition on recycled aggregate concrete. Specifically, the influence of a shrinkage reducing admixture(SRA) and recycled aggregate concrete was investigated. The shrinkage reducing admixture substantially reduces free, shrinkage and restrained shrinkage cracking while providing similar mechanical properties. Restrained shrinkage experiments were developed and shrinkage cracking was shown to be size dependent and recycled aggregate replacement rate. A mechanical properties experiment approach was developed to predict the behavior of a variety of recycled aggregate concrete specimens. This experimentally approach was used to successfully explain experimental results from a variety of mixture compositions and recycled aggregate concrete. This experiment was used to demonstrate the influence of material and structural properties on the potential for cracking.

      • KCI등재

        산국의 수량과 유효성분에 대한 NPK의 효과

        이경동,양민석,정연규,손보균,조주식,이성태,김필주 한국농화학회 2003 Applied Biological Chemistry (Appl Biol Chem) Vol.46 No.2

        본 연구는 3요소(N-PO_2O_5-K_2O)처리가 산국(Chysanthemum boreale M.)의 수량과 유효성분에 미치는 효과를 조사하여 효과적인 재배시스템을 개발하고자하였다. 처리구는 무처리, NPK(250-160-160), NK(250-0-160), PK(0-160-160kg/ha)의 5처리로 설정하여 산국을 재배한 결과, 건물수량은 NPK처리구가 PK처리구에 비하여 4.0배의 증수가 있었으며, 다른 처리구보다 무기이온의 흡수율, 생육 및 수량에서 NPK처리구가 가장 우수하였다. 식용으로 많이 쓰이는 꽃의 주요 아미노산은 proline, glutamic acid과 aspartic acid이였고, 다른 처리구들에 비하여 NPK처리구가 높은 함량을 보였다. 혈압강하효과가 우수한 cumambrin A는 PK처리구에 비하여 NPK처리구가 6.2배의 증수효과가 있었다. NK처리구는 NP처리구보다 cumambrin A의함량을 높이기 위해서는 인산의 시용보다 칼리의 시용이 더 요구되며, 야외포장에서의 인산과 칼리의 적정 시비량의 설정이 필요하다고 판단된다. To establish the fertilization condition to increase the productivity of Chrysanthemum boreale M. with high quality, the effects of three nutrients (N, P, K) on the yields and the effective components were investigated in the pot scale. NPK was applied by chemical fertilizers with N-P_2O_5-K_2O = 250-160-160 kg/ha as a main treatment, and NP (N-P_2O_5 = 250-160 kg/ha), NK (N-KO = 250-160 kg/ha), and PK (PO_2-KO_5 = 160-160 kg/ha) treatments were settled as comparison. Dry yields of C. boreale M. was increased significantly to 4 fold higher by nitrogen. Nitrogen increased apparently plant growth and inorganic nutrient uptake. In the flower, which is most useful and edible part as a herbal medicine, main amino acids were glutamic acid and aspartic acids, and the total content was increased significantly by three elements of application. In addition, the content of cumambrin A, which is known to have the effect of blood-pressure reduction, was increased source to 6.2 times by nitrogen higher than that in PK treatment. Potassium was more effective in biosyndiesis of cumatnbrin A than phosphorus, but the biological pathway was not clear, still.

      • 뇌사환자의 갑상선 기능, 전신대사 및 중증도에 관한 연구

        이영주,정금희,왕희정,문봉기,한연희,이영석 아주대학교 의과학연구소 1999 아주의학 Vol.4 No.1

        Background and Objectives : Brain death may lead to hormonal depletion, metabolic derangement and multiple organ dysfunction. We have carried out present study to examine the effects of brain death on the thyroid function, metabolic indices, and the severity scoring systems. Methods : 13 adults patients admitted for organ donation or brain death evaluation were examined after brain death was confirmed. Thyroid hormones measured were .thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), and free thyroxine (FT4). The metabolic indices measured were arterial ketone body ratio (AKBR), lactic acid (LA), and base defiat (BD). as for reference to the severity scoring systems, APACHE Ⅲ and multiple organ failure score (MOFS) were assessed on the day of brain death confirmation. Arterial blood was drawn for all measurements. Results : As for the thyroid function, there were significant decreases in T3 (40.48±20.96 ng/dL) and T4 (3.47±2.15 ㎍/dL), but no significant change in FT4 (0.75±0.31 ng/dL) and TSH (1.12±1.37 uIU/mL) compared to the normal range. Significant decreases in AKBR (0.39±0.31) and BD (-9.46±5.83 m㏖/L), and significant increase in LA (2.57±2.46 m㏖/L) In metabolic indices, were shown, as for severity scoring systems, APACHE Ⅲ score (101.54±19.41) and MOF score (9.11±2.57) indicated a high mortality. There were significant correlation between thyroid hormones (r=0.565 -0.781) but no correlation among other indices. Also, significant inverse correlations were shown between base deficit and lactic acid (r=-0.660), APACHE Ⅲ score (r=-0.726) and MOF score (r=-0.604). The highest correlation was observed between APACHE Ⅲ score and MOF score (r=0.851). Conclusions : As for the thyroid function, significant decrease in T3 and T4, and almost normal range of FT4 and TSH imply the euthyroid sick syndrome. Abnormal finding of the metabolic parameters indicates an inhibition of the aerobic metabolic rate of the body as a whole. And the severity scoring parameters are compatible with high mortality.

      • SCIESCOPUSKCI등재
      • SCIESCOPUSKCI등재
      • KCI등재

      연관 검색어 추천

      이 검색어로 많이 본 자료

      활용도 높은 자료

      해외이동버튼