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        검색결과 10

        2.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 철근콘크리트 건물에 대한 유전자 알고리즘 기반의 최적구조설계기법을 제시하고자 한다. 목적함수는 구조 물의 비용과 이산화탄소 배출량을 동시에 각각 최소화하는 것이다. 비용 및 인산화탄소 배출량은 구조설계안에서 얻을 수 있는 단면치수, 부재길이, 재료강도, 철근량 등과 같은 설계정보를 통해 계산한다. 즉, 구조물의 물량을 기초로 하여 비용과 이산화탄소 배출량을 평가한다. 재료의 운반, 시공 및 건물 운영 단계에서 발생하는 비용 및 이산화탄소 배출량은 본 연구에 서 제외한다. 제약조건은 철근콘크리트 건물을 구성하는 기둥과 보 부재의 강도조건과 층간변위조건이 고려된다. 제약조건 을 평가하기 위해 OpenSees를 활용한 선형정적해석이 수행된다. 제약조건을 만족시키면서 목적함수에 대해 최소의 값을 제 시하는 설계안을 찾기 위해 유전자 알고리즘이 사용된다. 제시한 알고리즘의 적용성을 검증하기 위해 4층 철근콘크리트 모 멘트 골조 예제에 제시하는 기법을 적용하여 검증한다.
        4,000원
        3.
        2011.05 구독 인증기관·개인회원 무료
        The aim of this study was to evaluate light emitting diodes (LEDs) as the potential attractants against Spodoptera exigua on various wavelengths, light intensity and light duration, and compared to that of commercial control, flourescent lamp. The phototactic response to S. exigua was tested by single and complex wavelengths. The single wavelengths were composed as follows: blue (470 nm), green (520 nm), yellow (590 nm) and red (625 nm). The complex wavelengths was combined with two single wavelengths, such as blue-green, blue-yellow, blue-red, green-yellow, green-red and yellow-red. When the optimal light condition was investigated, the all light treatments attracted the highest number of S. exigua at 40 lux intensity and 60 min duration. Based on the single wavelengths under optimal light condition, the green LED exhibited the highest attraction rate (88.9%), followed by blue (81.1%), yellow (63.3%) and red (56.7%), respectively. In case of complex wavelengths under same conditions, the bluegreen complex (93.3%) had the significantly highest attractive activity, whereas blue-yellow, blue-red, green-yellow, green-red and yellow-red wavelengths were slightly decreased in comparison with single wavelengths. These data clearly show that blue-green complex had the greatest attraction against S. exigua.
        4.
        2011.05 구독 인증기관·개인회원 무료
        Sweet potato whitefly, Bemisia tabaci, is one of the most common and critical green house pests in the world. The object of this study was to evaluate the attraction effect of various colored high power light emitting diodes (HPLEDs) against B. tabaci. These insects with diverse HPLEDs were examined by LED equipped chamber in the dark room at 27±0.5℃ and 60±5% relative humidity. Evaluated light-sources were blue (470±10 nm), green (520±5 nm), yellow (590±5 nm) and red (625±10 nm) HPLEDs, and tested with various illuminance intensity at 20, 40, 60, 80 and 100 lux. Base on the attraction rates, the green (94.4%) HPLED was the most effective against B. tabaci, followed by yellow (78.9%), blue (71.1%) and red (60%) HPLEDs. Furthermore, these data show that both the 80 lux intensity and 40 min light-exposure time using the green HPLED was the most suitable for attraction of B. tabaci. Putting all results, our data will provide the useful information for eco-friendly pest control against B. tabaci.
        5.
        2010.10 구독 인증기관·개인회원 무료
        This study presented a development of a phototactic chamber used for pest monitoring. The chamber was constructed by opaque acrylic body. Transparent acrylic wall of the chamber for light-exposure were fitted at both side end parts of the inside chamber. Side parts of the outside chamber were made of removable cover in combination with the air circulation system and light source such as LED or fluorescent. The insect entrance holes was positioned at the center part of the chamber to efficiently dispersed pests, and then nylon net was equipped inside the chamber to prevent the escape of inserted pests. Two opaque partition walls of the inside chamber were made of the movable plate, in order to the control of the light-exposure and the response termination. We also carried out behavioral experiment against various pest species by using the phototactic chamber. Consequently, the phototactic chamber was confirmed suitable result of behavioral experiment. Therefore, we believed that the test chamber help to understand the phototactic responses of various pests.
        6.
        2010.10 구독 인증기관·개인회원 무료
        To response evaluation of high power light emitting diodes (HPLEDs) as potential attractants to the Spodoptera exigua adults, we investigated the attractiveness of specific wavelength, illuminance intensity and light-exposure time, and compared them to the fluorescent. The all light treatments with the 40 lux intensity attracted the significantly highest number of S. exigua. The optimal light-exposure time exhibited the highest attraction rate at the 60 min. When the attraction and repellent rate in the optimal conditions to the S. exigua was surveyed, the white HPLED exhibited the highest attraction rate (91.1%), whereas the red HPLED exhibited the most repellent rate (33.3%). When evatuated of illuminance efficiency with fluorescent as control, white and red HPLED were found to be 9.14 and 10.34 times more efficient than fluorescent. These data clearly show that both the 40 lux intensity and the 60 min light-exposure time by using the white HPLED was the most suitable for attraction of the S. exigua.
        7.
        2017.05 서비스 종료(열람 제한)
        게르마늄은 주로 광섬유, 반도체 등에 사용되고 있으며, 고가의 희소금속이므로 게르마늄에 대한 회수 및 재활용 기술 개발은 각국에서 경쟁적으로 진행되고 있다. 하지만 국내에서는 게르마늄에 대한 재활용 실적이 전무하며, 전량을 수입해서 사용하는 희소금속이므로 게르마늄에 대한 재활용 기술 개발이 필수적이다. 특히, 광케이블에 사용되는 광섬유에는 1km당 약 0.54g의 게르마늄을 함유하고 있으므로, 본 연구에서는 광섬유를 게르마늄 추출 대상으로 선정하였다. 또한, 게르마늄은 1kg당 150만원의 고가 희소 금속이므로 관련 기술 개발시 파급효과가 클 것으로 판단하였다. 본 개발 기술은 광섬유에서 실리카(Si)와 합금형태로 존재하는 게르마늄을 추출하기 위하여 Na 화합물과 염산을 이용한 선택적 추출을 적용하였으며, 게르마늄의 추출 효율을 알아보기 위하여 추출액에 대한 ICP 분석을 실시하였다. 본 연구에서 사용한 Na 화합물은 광섬유의 주성분인 실리카 성분을 석출시켜 제거하는 역할을 하며, 추출 용매인 염산은 질산, 황산과의 추출 효율을 비교하여 최종 추출 용매로 선정하여 실험을 진행하였다.
        8.
        2014.03 KCI 등재 서비스 종료(열람 제한)
        Carbonization process with pig manure is carried out to estimate the reaction kinetics with increasing carbonizationtime and temperature in the process. From the examination of conversion characteristics of pig manure, carbonizationreaction can be described by the 1st order kinetic reaction. Degree of carbonization, which can be expressed by C/H moleratio, is increased with increasing carbonization temperature. As increased carbonization temperature from 250oC to 400oC,reaction rate constant in the 1st order kinetic reaction is also increased from 0.0622min−1 to 0.1999min−1. Frequency factorand activation energy in Arrhenius equation for pig manure in the carbonization process can be decided by 1.06×10−3min−1 and 5441.8kcal/kmole, respectively. From the results of the reaction kinetics including TGA and SEM analysis,it is desirable that pig manure should be carbonized below carbonization temperature 400oC.
        9.
        2014.01 KCI 등재 서비스 종료(열람 제한)
        In order to prevent the spreading infectious disease in domestic animal, livestock excretion should be controlled bysterilization. The basic concept of sterilization can be described by thermal treatment under vacuum state. From the basicconcept of sterilization, livestock excretion can be converted to produce renewable energy using the method ofcarbonization and the method of carbonization can also be reduced greenhouse gas effectively. Chicken manure is usedas a sample of renewable energy source in the carbonization reactor. The basic energy characteristics of chicken manuresuch as proximate analysis, and heating value are estimated. The carbonization residue of chicken manure which isobtained from carbonization experiment is subject to several analyses in order to examine the energy characteristics suchas heating value, fuel ratio, combustible index and yield. As increased carbonization temperature, both heating value andfuel ratio (fixed carbon/volatile combustible) of the residue are increased up to 350oC but yield of the residue is decreased.From the results of bulk density, fuel ratio and total heating value of the residue, the optimal conditions of carbonizationtemperature and time can be decided by about 350oC and 15min. Since the residue of chicken manure can not be satisfiedwith the standard of the third grade of solid fuel product, it is desirable that chicken manure be modified with othermaterials to improve an energy potential and to use as a clean fuel.
        10.
        2013.11 서비스 종료(열람 제한)
        The estimated that 114 million units of fluorescent lamp are sold every year, and that 70% or more spent fluorescent lamps (SFLs) are generated at business sites. According to Korea Lighting Recycling Corporation, recycled amount of SFLs selected as EPR (Extended Producer Responsibility) items from 2004 has been improved from 35,250,000 units in 2010 to 37,950,000 units in 2011, which recorded the greatest amount. Based on the year 2011, SFLs have been recycled by 31.5%, but their recycled rate is insufficient yet, compared to the recycling rate of metal cans or glass bottles, which are about 80%. The base cap of SFLs as a raw material was used in this experiment. Base cap contains an insulation sieve plate, aluminum cap, copper terminal, tempered glass, filament, and copper/iron mixed wire that goes through this glass. In order to protect a filament that is made up of tungsten for the electricity to flow, circular plate consisted of iron encloses the filament. Separating apparatus of SFL base cap used in this experiment is a device which has used impact crushing technique using hammer, screen separation and magnetic separation for the purpose of recovering aluminum, copper and iron contained in SFL. Impact hammer crusher, a device that separates aluminum from other materials by hammer impaction on the base cap that is separated by end-cutting, causes a significant reduction for other materials to be included in the collectible materials by separating aluminum, copper and iron from the base cap by using hammer crusher at 3 stages. Iron was collected by using a magnetic separation unit and the collectible materials were separated into aluminum with larger particles, and glass and other materials with smaller particles by screen separation. The separation performance was estimated for the 3 stages of hammer crusher unit to recover aluminum from the base-cap of SFLs and the separation performances are 94% at the 1st stage, 97% at the 2nd stage, and 98% at the 3rd stage, respectively.