검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 198

        81.
        2013.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Structural insulated panels, structurally performed panels consisting of a plastic insulation bonded between two structural panel facings, are one of emerging products with a viewpoint of its energy and construction efficiencies. These components are applicable to fabricated wood structures. In Korea, there are few technical documents regulated structural performance and engineering criteria in domestic market. This study was conducted to identify fundamental performance of both monotonic load and quasi static cyclic load for SIPs in shear wall application. Static test results showed that maximum load was 44.3kN, allowable shear load was 6.1kN/m, shear stiffness was 1.23 M N/m, and ductility ratio was 3.6. Cyclic test was conducted by two kinds of specimens : single panel and double panels. Cyclic test results, which were equivalent to static test results, showed that maximum load was 45.42kN, allowable shear load was 6.3kN/m. Furthermore the accumulated energy dissipation capability for double panels was as 2.3 times as that for single panel. From performance of structural tests, it was recommended that the allowable shear load for panels was at least 6.1kN/m.
        4,000원
        82.
        2013.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 수준별 압력(760, 560, 360, 160 mmHg)에 따른 튀김유의 산화안정성에 미치는 영향에 대하여 실험하였다. 본 연구에서는 상압(760 mmHg) 및 감압(560 mmHg, 360 mmHg, 160 mmHg) 상태에서 튀김유를 일정한 온도(180℃)로 유지하고, 8시간 간격으로 튀김반죽을 교체하면서 채취한 튀김유를 이용하여 상압과 감압 상태에 따른 튀김유의 산패 정도를 acid value(AV), peroxide value(POV) 및 지방산 측정, 색도, 갈변도를 통해서 알아보았다. 산가의 경우, 네 압력 모두 튀김의 시간이 증가할수록 유지의 산가 또한 증가하였다. 48 시간 튀긴 후 채취한 유지의 산가에서는 760, 560, 360, 160 mmHg 각각 1.28, 1.58, 1.34, 0.40으로 160 mmHg가 다른 압력들과 비교하면 확연히 더디게 증가한다는 것을 알 수 있었다. 48시간 동안 튀긴 후 채취한 식용유지의 과산화물가는 160 mmHg가 0.81 meq/㎏으로 760 mmHg의 1.52 meq/㎏에 비해 50%로 낮은 수치를 보였다. 지방산 조성에서는 네 압력 모두 스테아르산, 올레산, 리놀렌산(오메가 6)은 증가하였고, 리놀레산과 리놀렌산(오메가 3)은 각각 감소하는 경향을 나타냈다. 색도에서는 명도를 나타내는 L값은 유의적인 차이가 나타나지 않았지만, 적색도를 나타내는 a값에서는 네 압력 모두 튀김 시간이 길어질수록 감소하는 경향을 나타냈고, b값은 시간이 지남에 따라 증가하는 경향을 보였다. 갈색도의 결과는 네 압력 모두 시간이 지날수록 증가하는 경향을 보였지만, 160 mmHg는 다른 압력들보다도 가장 낮은 증가를 보였고, 급속하게 갈색도가 증가하는 40시간에서도 다른 압력들 만큼 큰 증가를 보이지 않았다. 본 연구 결과, 감압상태에서 식품을 튀겼을 때 튀김유의 산패도를 감소시킬 수 있었다. 이 결과에 따라 튀김유 산패로 인한 빈번한 튀김유 교체를 줄여 비용적인 절감효과와 튀김유의 장시간 사용이 가능할 것으로 생각된다. 이로 인해 튀김유 사용량을 절감할 수 있어 업체의 경제성 향상 및 발생되는 폐유를 줄여 환경보호를 겸할 수 있을 것이다.
        4,000원
        83.
        2012.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper shows scheduling methods to utilize heat pump systems as demand response resources in the smart grid environment. The heat pump system has a partial thermal storage tank which could be used at any time according to the consumer behavior based on the real time electricity tariff system. Some scheduling methods are proposed and an optimization basis is established considering areas, insulation conditions, heating set temperature, minimum heating maintaining period of thermal storage, maximum size of tank, etc.
        4,000원
        84.
        2012.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Recently, the demand for the miniaturization of printed circuit boards has been increasing, as electronic devices have been sharply downsized. Conventional multi-layered PCBs are limited in terms their use with higher packaging densities. Therefore, a build-up process has been adopted as a new multi-layered PCB manufacturing process. In this process, via-holes are used to connect each conductive layer. After the connection of the interlayers created by electro copper plating, the via-holes are filled with a conductive paste. In this study, a desmear treatment, electroless plating and electroplating were carried out to investigate the optimum processing conditions for Cu via filling on a PCB. The desmear treatment involved swelling, etching, reduction, and an acid dip. A seed layer was formed on the via surface by electroless Cu plating. For Cu via filling, the electroplating of Cu from an acid sulfate bath containing typical additives such as PEG(polyethylene glycol), chloride ions, bis-(3-sodiumsulfopropyl disulfide) (SPS), and Janus Green B(JGB) was carried out. The desmear treatment clearly removes laser drilling residue and improves the surface roughness, which is necessary to ensure good adhesion of the Cu. A homogeneous and thick Cu seed layer was deposited on the samples after the desmear treatment. The 2,2'-Dipyridyl additive significantly improves the seed layer quality. SPS, PEG, and JGB additives are necessary to ensure defect-free bottom-up super filling.
        4,000원
        85.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the study, space cooling performance of air source heat pump(ASHP) was evaluated in a pilot house. The ASHP, which provide for floor heating, domestic water heating and space cooling/heating, shows cooling capacity of 14.0 kW, when COP of ASHP was 3.21 based on test performance of KS C 9306. Test results shows that cooling capacity was depended on frequency of the compressor. The variable refrigerant flow rate for cooling were supplied into diverse room by using LEV. The COP at setting room temperature of 26℃ was 6.3% higher than the COP at that of 24℃, when the spending time in operation was decreased as 21.2%.
        4,000원
        86.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Structure Insulated Panel (SIP) is an wooden structure material with which structure and insulation functions are satisfied. Hence, it would be a cost-effective model to implement low energy house which has higher insulation and structure performance and which the wall thickness is able to be reduced. In this study, performance of thermal insulation and fire resistance were evaluated in order to verify applicability to low energy house. Fire resistance test is performed on vertical load bearing members for partitions, and the test results satisfy one hour of fire resistance condition according to KS F 2257. The members include two layers of fireproof gypsum board with thicknesses of 12.5mm attached to SIP. Thermal insulation performance is satisfied with the 2012 standard (0.225W/㎡·K). As the performance of resistance and thermal insulation are satisfied, SIP is expected to be applied to low energy building materials. In the future, the structural safety will be confirmed by structural performance and seismic performance test and the guidelines for distribution will be drawn up.
        4,200원
        87.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Structural insulated panels, which are structurally performed panels consisting of a plastic insulation bonded between two structural panel facings are one of emerging products with a viewpoint of its energy and construction efficiencies. These components are applicable to fabricated wood structures. By now, there are few technical documents regulated structural performance and engineering criteria in domestic market. This study was conducted to suggest fundamental reports such as racking resistance, axial capacity, transverse load capacity, and lintel load capacity for SIPs. Test results showed that maximum load was 44.3kN, allowable load was 14.7kN for racking resistance, and that maximum load was 137.6kN, allowable load was 37.4kN/m for axial compression capacity. For transverse load capacity, test results showed 10.3kN/㎡ of maximum load, 3.4kN/㎡ of allowable load. For lintel load capacity for SIPs dependent to lengths, allowable loads were 20.4kN for 600㎜ long lintel, 23.9kN for 1,200㎜ long lintel, 19.3kN for 1,800㎜ long lintel, and 2,400㎜ long lintel had 14.1kN of allowable load. In the near future, when the allowable load for wall application is established, SIPs is considered to substitute the existent post-and-lintel construction to bearing wall structure.
        4,000원
        88.
        2012.04 구독 인증기관·개인회원 무료
        This study is related to evaluate the performance of structural insulated panels. This panel are composed of exterior structural member with insulated materials simultaneously. The test to evaluate the transverse capacity and lintel capacity was performed according to ASTM E-72 and KS F2273. The test result shows the panels are applicable to the required load sufficiently.
        89.
        2012.04 구독 인증기관·개인회원 무료
        This study is related to evaluate the performance of structural insulated panels. This panel plays a role as structural member and insulation simultaneously. This study is focused to test the racking shear capacity and axial compression capacity based on ASTM E-72 and KS F2273. The test result shows the panels are applicable to the required load sufficiently.
        90.
        2012.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        고력볼트의 초기 체결력은 미끄럼표면조건에 따라, 일정시간이 경과될 때까지, 축력저하가 발생한다. 이 연구는 미 끄럼접합부 표면에 도장이 되어있는 경우, 도장의 크리프현상에 따른 축력저하에 관한 예측 모델을 찾는 것이다. 이 실험연구 범위는 무기질 아연 프라이머로 도포된 볼트접합부의 장기축력저하에 한정한다. 실험에 적용된 볼트종 류는 다크로 도포된 토크쉬어 볼트이다. 대상 표면의 도막 두께는 각각 96, 168, 226㎛ 이었다. 도막두께가 증가될 수록, 초기 체결이후 축력이완율은 도막의 크리프 때문에 10%에서 18%로 증가되었다. 장기축력예측을 위한 정량적 인 모델은 도막두께에 따른 크리프 스트레인과 경과된 시간사이에 회귀분석 결과로 얻어진다. 이 실험연구를 통해 미끄럼표면 도막의 크리프 거동특성을 알 수 있다면, 일정시간 경과후 고력볼트 체결력은 초기 체결력으로부터 구 할 수 있다. 본 실험결과를 근거로 각 도막두께에 대한 장기축력이완이후의 고력볼트 체결력에 관한 정량적인 수식 을 제안하였다.
        4,000원
        91.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목 적: 취학 전 어린이와 부모의 시력검사 행동양식을 조사하여 취학 전 어린이의 시력검사 참여율을 높 이기 위한 개선방안을 제안하고자 한다. 방 법: 대전지역 12개 유치원의 만6세(평균연령 6.0±0.2세) 어린이 487명을 대상으로 시력검사와 자동 굴절검사, 자각식 굴절검사, 가림검사, 허쉬버그검사를 실시하였다. 설문지를 이용하여 유치원 어린이와 부 모의 시력검사 행동양식을 분석하였다. 결 과: 조사대상자들의 등가구면굴절력은 오른쪽 눈 -0.15±0.81D, 왼쪽 눈 -0.14±0.75D였다. 조사대 상 어린이 487명 중 73명(15.0%)이 비정시이었고 이들 중에서 5명(6.8%)이 안경을 착용하고 있었다. 취학 전 어린이에서 189명(42.4%)이 시력검사 경험이 있었으며 이들 중에서 56.1%(n=106)가 집단시력검사 기회 를 이용하였다. 부모들에서는 54.8%(부 57.9%, 모 51.6%)가 정기적으로 시력검사를 받고 있었고 이들의 51.6%(부 55.8%, 모 46.6%)가 집단시력검사 기회를 이용하고 있었다. 취학 전 어린이와 그들의 부모의 시 력검사 행동양식은 비슷한 경향을 보였다. 결 론: 취학 전 어린이의 시력검사는 제도화된 집단검사를 통해 시행되어야 하며 참여율을 높이고 검사 결과의 신뢰성을 높이기 위해 시력검사 전문가인 안경사를 활용하는 방안을 제안한다.
        4,200원
        95.
        2011.05 구독 인증기관·개인회원 무료
        쯔쯔가무시증의 매개체인 털진드기의 채집을 위해 야생설치류를 포획하는 대체 방법으로 고안된 진드기 접착채집기를 이용하여 2010년 4월부터 2011년 3월까지 경상북도 고령군 및 경기도 화성시에서 계절적 발생밀도 조사를 실시하였다. 조사 기간 동안 고령군에서 1,354개체, 화성시에서 153개체, 총 1,507개체의 털진드기 가 채집되었으며, 개체군의 환경별 발생밀도는 각 조사 지역마다 다르게 나타났다. 고령군에서는 논두렁에서 581개체(42.8%)로 가장 많이 채집되었고, 그 다음으로 밭(356개체, 26.3%), 냇가(318개체, 23.5%), 산(99개체, 7.3%)순이었으며, 화성시 에서는 밭에서 135개체(88.2%)로 가장 많았고, 수로(11개체, 7.2%), 산(6개체, 3.9%), 밤나무숲(1개체, 0.7%)순이었다. 털진드기 개체군의 계절적 발생양상을 보면 연 중 2개의 정점(peak)을 보이는데 4월에 작은 정점을 보인 후 여름에는 채집되지 않 았다가 11월에 큰 정점을 나타냈다. 본 조사를 통해 주목할 만한 점으로 가을철 발 생 이후 털진드기가 겨울을 지나 봄까지 지속적으로 활동하는 것이 확인되었다. 이상의 채집기를 이용한 진드기 발생밀도조사는 설치류 채집을 통한 밀도조사와 유사한 양상을 보였으며, 보균율 검사와 종합하여 쯔쯔가무시증의 유행예측에 적 용할 수 있을 것이다.
        96.
        2011.04 구독 인증기관·개인회원 무료
        The initial clamping forces of the high strength bolts depending on the different faying surface conditions drop within 1,000 hours regardless of loading any other external force or loosening of the nut. This study focused on the mathematical model for relaxation confined to creep on coated faying surface after initial clamping. The quantitative equation for estimating long term relaxation was derived from nonlinear regression analysis for relation between the creep strain of coated surface and the elapsed time.
        97.
        2011.04 구독 인증기관·개인회원 무료
        This study focused on the static behavior of steel beams reinforcement by AFRP sheets. The main objective of the experimental programme was the evaluation of the force transfer mechanism, the increment of the beam load carrying capacity and the bending stiffness. A bending test was conducted on a H-shaped steel beam, with aramid FRP sheets bonded to its flanges. The mid-span deflection and the strain from three points along AFRP sheets were recorded Test results exhibit that the increment of the load-carrying capacity with reference to a mid-span deflection level of 15 mm(1/125mm of the clear span) was equal to 9.4% and for the two layers case, an elastic stiffness increment is slightly higher than one layer case.
        98.
        2010.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Films consisting of a silicon quantum dot superlattice were fabricated by alternating deposition of silicon rich silicon nitride and Si3N4 layers using an rf magnetron co-sputtering system. In order to use the silicon quantum dot super lattice structure for third generation multi junction solar cell applications, it is important to control the dot size. Moreover, silicon quantum dots have to be in a regularly spaced array in the dielectric matrix material for in order to allow for effective carrier transport. In this study, therefore, we fabricated silicon quantum dot superlattice films under various conditions and investigated crystallization behavior of the silicon quantum dot super lattice structure. Fourier transform infrared spectroscopy (FTIR) spectra showed an increased intensity of the 840 cm-1 peak with increasing annealing temperature due to the increase in the number of Si-N bonds. A more conspicuous characteristic of this process is the increased intensity of the 1100 cm-1 peak. This peak was attributed to annealing induced reordering in the films that led to increased Si-N4 bonding. X-ray photoelectron spectroscopy (XPS) analysis showed that peak position was shifted to higher bonding energy as silicon 2p bonding energy changed. This transition is related to the formation of silicon quantum dots. Transmission electron microscopy (TEM) and electron spin resonance (ESR) analysis also confirmed the formation of silicon quantum dots. This study revealed that post annealing at 1100˚C for at least one hour is necessary to precipitate the silicon quantum dots in the SiNx matrix.
        4,000원
        99.
        2010.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Solar cells have been more intensely studied as part of the effort to find alternatives to fossil fuels as power sources.The progression of the first two generations of solar cells has seen a sacrifice of higher efficiency for more economic use ofmaterials. The use of a single junction makes both these types of cells lose power in two major ways: by the non-absorptionof incident light of energy below the band gap; and by the dissipation by heat loss of light energy in excess of the band gap.Therefore, multi junction solar cells have been proposed as a solution to this problem. However, the 1st and 2nd generation solarcells have efficiency limits because a photon makes just one electron-hole pair. Fabrication of all-silicon tandem cells using anSi quantum dot superlattice structure (QD SLS) is one possible suggestion. In this study, an SiOx matrix system was investigatedand analyzed for potential use as an all-silicon multi-junction solar cell. Si quantum dots with a super lattice structure (Si QDSLS) were prepared by alternating deposition of Si rich oxide (SRO; SiOx (x=0.8, 1.12)) and SiO2 layers using RF magnetronco-sputtering and subsequent annealing at temperatures between 800 and 1,100oC under nitrogen ambient. Annealing temperaturesand times affected the formation of Si QDs in the SRO film. Fourier transform infrared spectroscopy (FTIR) spectra and x-rayphotoelectron spectroscopy (XPS) revealed that nanocrystalline Si QDs started to precipitate after annealing at 1,100oC for onehour. Transmission electron microscopy (TEM) images clearly showed SRO/SiO2 SLS and Si QDs formation in each 4, 6, and8nm SRO layer after annealing at 1,100oC for two hours. The systematic investigation of precipitation behavior of Si QDsin SiO2 matrices is presented.
        4,000원
        1 2 3 4 5