• 제목/요약/키워드: cover structure

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주기적인 슬릿을 갖고 유전체층으로 덮힌 평행평판 도파관에서의 누설파 복사 및 표면파 launching (Leaky Wave Radiation and Surface Wave Launching Problem in a Dielectrically Covered Periodically Slitted Parallel-Plate Waveguide)

  • 이종익;이철훈;조영기
    • 전자공학회논문지D
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    • 제36D권4호
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    • pp.25-33
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    • 1999
  • 유전체로 덮혀 있고 주기적인 슬릿을 갖는 평행평판 도파관에서의 누설파 복사 및 표면과 TEM파가 입사되는 경우에 대하여 고려하였다. 모멘트 방법을 이용하여 무한한 주기적인 구조와 유한한 주기적인 구조를 해석하였다. 유전체 커버가 슬릿을 갖는 누설파 안터나의 성능에 미치는 영향을 보이기 위하여 유전체의 두께에 대한 도파관 내부에서의 반사전력과 투과전력, 자유공간으로의 복사효율, 유전체슬램으로의 표면파 launching 효율, 안테나 이득, 그리고 복사패턴 등의 수치해석결과들을 제시하였다. 또한 제안된 주기적인 구조를 이용한 표면파 lauching 효율의 개선방법을 기술하엿으며 최대효율은 이론적으로 97.5%에 이르렀다. 따라서 이 구조는 image 도파관이나 유전체 격자 안테나의 효과적인 급전기로서 유망하리라 사료된다.

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한의원의 한방물리요법 이용 현황과 건강보험 급여화에 대한 인식 (The Utilization of Physical Therapies in the Korean Medicine Clinics : A Survey for National Health Insurance Planning)

  • 신미숙;신병철;이명종;김호준;송윤경;송미연;신승우;임병묵
    • 한방재활의학과학회지
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    • 제19권3호
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    • pp.101-109
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    • 2009
  • Objectives : This study aimed to investigate the present status of physical therapies provided in the Korean medicine clinics, and to find out the priorities among and the estimated fees of physical therapies for the National Health Insurance plan. Methods : We administered nationwide survey to Korean medicine doctors using the on-line survey system. 16 physical therapies were listed in the Web-based questionnaires, and responders were asked to mark the therapies they used for their patients, and, for each therapy they marked, to fill in the form including the frequencies of service, service fees, target diseases, and priorities for health insurance coverage, etc. Results : Of 488 respondents, 93.7% provide more than one physical therapy for their patients, and each responder uses 5.9 physical therapies on average. 60-90% of physical therapies are being given to patients for free because they are not covered by the National Health Insurance. There is little evidence that the specialties of Korean medicine doctors are related with the use of physical therapies, but, in some therapies, the doctors with longer career years use the physical therapy more frequently. Most physical therapies are applied to the patients with musculoskeletal diseases, cardiovascular diseases, and nervous diseases, etc. Conclusions : Physical therapies are widely used among Korean medicine doctors without proper compensation. This could be the one of the main factors distorting the profit structure of Korean medicine clinics, and it encourages the National Health Insurance to cover physical therapies provided in the Korean medicine clinics.

LCD 구동 모듈과 WWAN 안테나 간의 전자기 간섭 감소에 대한 연구 (Reduction of Electromagnetic Interference between the LCD Driving Module and WWAN Antennas)

  • 김인복;박진현;강일흥;김홍준;우동식;김강욱
    • 한국전자파학회논문지
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    • 제23권6호
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    • pp.716-722
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    • 2012
  • 본 논문에서는 WWAN 대역의 노트북 안테나와 LCD 구동 모듈 간의 전자기 간섭이 노트북의 무선 통신에 끼치는 영항을 분석하고, 이러한 간섭을 줄이기 위한 대책을 논의하였다. LCD 구동 모듈에 의한 잡음원을 모의하기 위해 다중 대역 안테나를 설계, 제작하였고, 이를 사용하여 노트북 내에서 전자기 간섭에 의한 효과를 시뮬레이션 및 모델 실험을 통해 분석하였다. 그 결과, 노트북의 구조에 기인한 특정 주파수 대역에서 더 많은 잡음이 전달될 수 있음을 확인하였다. 또한, 구조물 변화에 의한 잡음 전달의 감소를 위해 구조물에 격벽을 세우고, 그 크기를 변경하며 전자기 간섭을 분석하였으며, 이러한 구조 변경이 통신 대역 내의 전자기 간섭을 감소시킬 수 있음을 보여주었다.

자동기상관측소의 국지기후대에 근거한 서울 도시 열섬의 공간 분포 (Spatial Distribution of Urban Heat Island based on Local Climate Zone of Automatic Weather Station in Seoul Metropolitan Area)

  • 홍제우;홍진규;이성은;이재원
    • 대기
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    • 제23권4호
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    • pp.413-424
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    • 2013
  • Urban Heat Island (UHI) intensity is one of vital parameters in studying urban boundary layer meteorology as well as urban planning. Because the UHI intensity is defined as air temperature difference between urban and rural sites, an objective sites selection criterion is necessary for proper quantification of the spatial variations of the UHI intensity. This study quantified the UHI intensity and its spatial pattern, and then analyzed their connections with urban structure and metabolism in Seoul metropolitan area where many kinds of land use and land cover types coexist. In this study, screen-level temperature data in non-precipitation day conditions observed from 29 automatic weather stations (AWS) in Seoul were analyzed to delineate the characteristics of UHI. For quality control of the data, gap test, limit test, and step test based on guideline of World Meteorological Organization were conducted. After classifying all stations by their own local climatological properties, UHI intensity and diurnal temperature range (DTR) are calculated, and then their seasonal patterns are discussed. Maximum UHI intensity was $4.3^{\circ}C$ in autumn and minimum was $3.6^{\circ}C$ in spring. Maximum DTR appeared in autumn as $3.8^{\circ}C$, but minimum was $2.3^{\circ}C$ in summer. UHI intensity and DTR showed large variations with different local climate zones. Despite limited information on accuracy and exposure errors of the automatic weather stations, the observed data from AWS network represented theoretical UHI intensities with difference local climate zone in Seoul.

매 시간단계의 등가정하중을 다중하중조건으로 이용한 준정적 구조최적화 방법 (Quasi-Static Structural Optimization Technique Using Equivalent Static Loads Calculated at Every Time Step as a Multiple Loading Condition)

  • 최우석;박경진
    • 대한기계학회논문집A
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    • 제24권10호
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    • pp.2568-2580
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    • 2000
  • This paper presents a quasi-static optimization technique for elastic structures under dynamic loads. An equivalent static load (ESL) set is defined as a static load set which generates the same displacement field as that from a dynamic load at a certain time. Multiple ESL sets calculated at every time step are employed to represent the various states of the structure under the dynamic load. They can cover every critical state that might happen at an arbitrary time. Continuous characteristics of dynamic load are simulated by multiple discontinuous ones of static loads. The calculated sets of ESLs are applied as a multiple loading condition in the optimization process. A design cycle is defined as a circulated process between an analysis domain and a design domain. Design cycles are repeated until a design converges. The analysis domain gives a loading condition necessary for the design domain. The design domain gives a new updated design to be verified by the analysis domain in the next design cycle. This iterative process is quite similar to that of the multidisciplinary optimization technique. Even though the global convergence cannot be guaranteed, the proposed technique makes it possible to optimize the structures under dynamic loads. It has also applicability, flexibility, and reliability.

Reaction of Global Collection of Rye (Secale cereale L.) to Tan Spot and Pyrenophora tritici-repentis Races in South Dakota

  • Abdullah, Sidrat;Sehgal, Sunish K.;Glover, Karl D.;Ali, Shaukat
    • The Plant Pathology Journal
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    • 제33권3호
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    • pp.229-237
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    • 2017
  • Rye (Secale cereale L.) serves as an alternative host of Pyrenophora tritici-repentis (PTR) the cause of tan spot on wheat. Rye is cultivated as a forage or cover crop and overlaps with a significant portion of wheat acreage in the U.S. northern Great Plains; however, it is not known whether the rye crop influences the evolution of PTR races. We evaluated a global collection of 211 rye accessions against tan spot and assessed the diversity in PTR population on rye in South Dakota. All the rye genotypes were inoculated with PTR races 1 and 5, and infiltrated with Ptr ToxA and Ptr ToxB, at seedling stage. We observed 21% of the genotypes exhibited susceptibility to race 1, whereas, 39% were susceptible to race 5. All 211 accessions were insensitive to both the Ptr toxins. It indicates that though rye exhibits diversity in reaction to tan spot, it lacks Ptr ToxA and ToxB sensitivity genes. This suggests that unknown toxins or other factors can lead to PTR establishment in rye. We characterized the race structure of 103 PTR isolates recovered from rye in South Dakota. Only 22% of the isolates amplified Ptr ToxA gene and were identified as race 1 based on their phenotypic reaction on the differential set. The remaining 80 isolates were noted to be race 4. Our results show that races 1 and 4 are prevalent on rye in South Dakota with a higher frequency of race 4, suggesting a minimal role of rye in the disease epidemiology.

그래핀 기반 지능형 나노복합소재를 이용한 고감도 임팩트 페인트 센서 개발 연구 (Development of Novel Impact Paint Sensor by Using Graphene based Smart Nano Composite)

  • 김성용;박세훈;최경락;박형기;강인필
    • 한국소음진동공학회논문집
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    • 제24권3호
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    • pp.247-252
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    • 2014
  • This paper presents a novel impact sensor which can be fabricated with smart paint made of grapheme. This smart nano paint can be easily installed on structures using a spray-on technique and that can make the sensor low cost and practical. The graphene effectively improves the piezoresistivity of the smart paint and that is available to achieve sensitive impact sensor with high gauge factor. The nano smart-paint can detect sufficient impact to cover the damaged energy range of the composite around 1~3J. The voltage outputs from the sprayed paints show fairly linear responses after signal processing. The impact makes deformation of the structure and it brings change of piezoresistivity of the paint and those converts into voltage output consequently by means of a simple signal processing system. The nano smart paint is lightweight and easily applied to the structural surface, and there is no stress concentration. The nano smart paint is expected to be a cost effective and sensitive multi-functional sensor for composites and other damage monitoring applications in the field of structural health monitoring.

인공습지 내 개방수역 조성에 따른 처리효율분석 (Analysis of Treatment Efficiency according to Open-water in Constructed Wetland)

  • 김형철;윤춘경;엄한용;김형중;함종화
    • 한국물환경학회지
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    • 제24권6호
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    • pp.709-717
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    • 2008
  • The field scale experiment which is constructed with four sets (0.88 ha for each set) of wetland (0.8 ha) and pond (0.08 ha) systems was performed to examine the effect of plant coverage on the constructed wetland performance and to recommend the optimum development and management of macrophyte communities. After six growing seasons of wetlands, plant coverage was about 100%. And the concentration of DO showed low value (1.0~5.4 mg/L). This is caused by a blighted plant consumed dissolved oxygen with decay in water column. As the result, water column went to be anaerobic conditions and T-N removal rate are 58~67%. Dead vegetation increased nitrogen removal during winter because it is a source of organic carbon which is an essential parameter in denitrification. However, wetland released phosphorus caused by a blighted plant and accumulation, the removal rate of phosphorus might be decreased. To rise of DO concentration, the three open-waters were constructed in cell 3 and 4. Cell 3 has two open-waters (width 10 m, depth 1.8 m) and cell 4 has one open-water (width 20 m, depth 1.8 m). As the result, DO concentration and treatment efficiency of nutrient and BOD were improved. In case that constructed wetland is operated for a long time, physical circulation structure such as open water help continuous circulation of aerobic and anaerobic conditions. Through the constructed open-water, treatment efficiency of phosphorus and nitrogen in wetland could be improved effectively.

군락내 공간적 분석에 의한 세 종간 상관관계 (Three Species Associations with Spatial Autocorrelation Analysis in Community)

  • 허만규;허홍욱;김창호
    • The Korean Journal of Ecology
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    • 제23권1호
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    • pp.17-23
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    • 2000
  • 소나무(Pinus densiflora), 쥐똥나무(Ligustrum obtusifolium), 그리고 오리나무(Alnus japonica)의 공간적 상관관계를 생태적, 유전적 분석을 통해 살펴보았다. 이 가운데, 소나무와 쥐똥나무의 생태적 공간관계는 양의 상관관계를 나타낸 반면, 쥐똥나무와 오리나무는 음의 상관관계를 나타내었다. Moran의 I값과 표준편차(SND: standard normal deviate)값에 의하면 소나무는 18 m에서 집단구조를 형성 한 반면, 쥐똥나무는 12.5 m간격으로 집단구조가 형성되어 있었다. 오리나무는 명확한 집단구조가 결여되어 있었다. 소나무와 쥐똥나무의 두 종간의 공간구조에 있어, 유전적으로 유의한 상관관계가 형성 된 것은 소나무의 수관이 비교적 좁고, 적절한 피음효과를 제공함으로써, 쥐똥나무의 생육에 기여하였기 때문으로 생각된다. 오리나무와 쥐똥나무의 경우, 광합성과 관련한 수광경쟁에서 비교적 넓은 오리나무의 수관 때문에,두 종간의 동소적 관계가 방해되는 것으로 추정된다.

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고층고밀 아파트단지의 노후도 평가지표 개발 (A Study on the Evaluating Indicators of the Level of Deterioration in High-rise and high-density Apartments)

  • 조성희;이태경
    • 한국주거학회논문집
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    • 제20권4호
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    • pp.131-142
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    • 2009
  • High-rise and high-density apartment complexes have been built and supplied on a large scale in the 1st period of the New Town project in metropolitan areas since the late 1980s. Now It has become necessary to improve those apartment complexes, which have serious deterioration problems for aging more than about 20 years accompanying simultaneity and a large scale. The purpose of this research is to develop the evaluating indicators to measure the level of deterioration of apartments inclusively and practically in order to regenerate apartments as sustainable residential environments. This study is composed of the following four parts; (a) establishing the conceptual model of evaluation of apartment deterioration, (b) selecting evaluation items, (c) constituting evaluation measurement, and(d)weighting evaluation indicators. First, deterioration of apartments was conceptualized by physical. social, and economical aspects in terms of sustainable development and proposed the conceptual model of hierarchy structure of evaluation of apartment deterioration by literature reviews. Second, evaluating items were selected based on literature reviews of existing indicators and preceding studies about apartments of Korea and foreign countries. The evaluating indicators were identified as a total of 77 evaluating items which were composed of three dimensions and 9 attributes on the basis of the conceptual model. They cover comprehensive scope of the apartment such as unit, building, complex, and site. Third, as the measurement, the 5 point ordinal scale measure was suggested. The evaluating measurement including measure standards, measure methods, and measure contents were developed by each evaluating items. Lastly, the weighting of evaluating indicators was analyzed by AHP method conducted by survey on the expert group. Items were identified as high contributors or low contributors. The weighting of these items could suggest several evaluations according to the situation. The evaluation of the level of deterioration can be done by both total evaluation and a specific field of evaluation. In addition, it is easy to grasp deteriorated attributes or dimensions by providing a radar and bar chart showing evaluation results. These evaluating indicators could be a useful tool to grasp actual methods for the regeneration of apartments.