• 제목/요약/키워드: Field conditions

검색결과 6,830건 처리시간 0.035초

비탈면 녹화공법의 유형분석과 개선방안 연구 (A Study of Improvement Method and Analysis of Type of Revegetation Measures of Rock Slopes)

  • 전기성
    • 한국환경복원기술학회지
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    • 제5권5호
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    • pp.22-29
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    • 2002
  • This study was conducted to suggest develop revegetation methods and to classification of cutting-rock slopes revegetation type. The data was collected from pre-experienced data, reports and journal. Also research result was reflected from field research for the conditions of construction, vegetation types and field conditions. As the result of analyze, the factors affecting the plant coverage rates of cutting-rock slopes were period of construction, revegetation methods, slope gradient and slope length. Classification of cutting-rock slopes revegetation type was fourth from material of revegetation measures and spray type. It is recommended to adjust the proposed factor as environment, field condition and characteristic related with revegetation measures on slopes for the presentation of revegetation standard.

On buckling analysis of laminated composite plates using a nonlocal refined four-variable model

  • Shahsavari, Davood;Karami, Behrouz;Janghorban, Maziar
    • Steel and Composite Structures
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    • 제32권2호
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    • pp.173-187
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    • 2019
  • This study is concerned with the stability of laminated composite plates modelled using Eringen's nonlocal differential model (ENDM) and a novel refined-hyperbolic-shear-deformable plate theory. The plate is assumed to be lying on the Pasternak elastic foundation and is under the influence of an in-plane magnetic field. The governing equations and boundary conditions are obtained through Hamilton's principle. An analytical approach considering Navier series is used to fine the critical bucking load. After verifying with existing results for the reduced cases, the present model is then used to study buckling of the laminated composite plate. Numerical results demonstrate clearly for the first time the roles of size effects, magnetic field, foundation parameters, moduli ratio, geometry, lay-up numbers and sequences, fiber orientations, and boundary conditions. These results could be useful for designing better composites and can further serve as benchmarks for future studies on the laminated composite plates.

Optimization of dry-aging conditions for chicken meat using the electric field supercooling system

  • Chang-Hwan Jeong;Sol-Hee Lee;Hack-Youn Kim
    • Journal of Animal Science and Technology
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    • 제66권3호
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    • pp.603-613
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    • 2024
  • This study was designed to determine the optimal aging conditions after analyzing the physicochemical and microbiological properties of dry-aged chicken breast using an electric field supercooling system (EFSS). Chicken breast was aged for up 5 weeks at three different temperatures (0℃, -1℃, and -2℃). Aging and trimming loss at -2℃ treatment showed lower values than at 0℃ and -1℃ treatments. Thiobarbituric acid reactive substances and volatile basic nitrogen in all treatments increased during the aging process but showed the lowest levels at -2℃. As a result of analysis of aerobic bacteria, it is microbiologically safe to dry-age for up to 2 weeks at 0℃ and up to 3 weeks at -1℃ and -2℃. Therefore, the dry-aged chicken breast with EFSS was optimally aged for 3 weeks at -2℃.

Efficient electromagnetic boundary conditions to accelerate optimization of RF devices

  • Cho, Yong-Heui
    • International Journal of Contents
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    • 제7권4호
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    • pp.50-55
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    • 2011
  • To achieve efficient field formulations and fast numerical computations, the reciprocal relations and equivalence between tangential and normal boundary conditions for electromagnetic fields are discussed in terms of the Maxwell's differential equations. Using the equivalence of each boundary condition, we propose the six essential boundary conditions, which may be applicable to matching electromagnetic discontinuities to efficiently design RF devices. In order to verify our approach, the reflection characteristics of a rectangular waveguide step are compared with respect to six essential boundary conditions.

작업환경에서 의자 및 조명 조건이 근로에 미치는 영향에 관한 연구 (A Study on the Effect of Seating & Lighting conditions on Work)

  • 차상은;김상렬;이승주;김정동;김종석
    • 한국안전학회지
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    • 제13권1호
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    • pp.131-138
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    • 1998
  • This field study was conducted to survey the effect of seating & lighting conditions on work. The results were as follows ; Discomfortable parts of body caused by unsuitable sitting postures on work were low back 52.05%, leg 15.75%, neck 14.38% and arm 9.59%. Work conditions of sitting postures were needed arm rest, back rest of seat and adjustable seat height. Effect of work efficiency by lighting conditions were statistically significant relationship between glaring state of workstation and lighting state.

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가변 제한속도 표지판 크기기준 정립을 위한 안개재현 현장실험 (Fog Generated Field Test for Criteria of Sign Size of Variable Speed Limit Signs)

  • 김용석;이석기;김솔람
    • 한국도로학회논문집
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    • 제18권6호
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    • pp.87-96
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    • 2016
  • OBJECTIVES : A fog generated field test was conducted to analyze the relationship between different sizes of variable speed limit signs and the legibility distance under various fog density conditions. By using this study, appropriate sizes of signs can be selected depending on the density of fog. METHODS : An actual tunnel was selected as the area for this test, as other places cannot maintain the fog condition because of rapid air current. A total 121 subjects were recruited for this test, which took place over the course of four days. The test on the first day was conducted under normal weather conditions for comparison. Visibility-distance detecting sensor was used to measure the visibility distance due to the fog density time, simultaneously with the evaluation of legibility distance by subjects. RESULTS : The test results show the relationship between the different sizes of signs and the legibility distance corresponding to the visibility distance due to both non-fog and fog generated conditions. According to the technical test results, appreciable amount of reduction in legibility distance due to fog was resulted in all sizes of signs. Moreover, the legibility distance is reduced proportionately with the decrease in the visibility distance due to fog. CONCLUSIONS : The results of this study can be used to select appropriate sizes of valuable speed signs under fog conditions. Hence, drivers can expect to have more room to respond to adverse weather conditions, thereby reducing the risk of accidents.

50% 미만 부하조건에서의 3상 몰드변압기 진동 측정과 분석 (The vibration detection and analysis of 3-phase cast resin transformer in less than 50% load conditions)

  • 송길목;방선배;김종민;김영석;최명일
    • 전기학회논문지
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    • 제61권7호
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    • pp.992-997
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    • 2012
  • In this paper, we were analyzed the vibration characteristics of the three-phase cast resin transformer using less than 50% of load in the field. Most of the cast resin transformer is less than 50% in the domestic field is used for load conditions. Consisting of a solid insulator cast resin transformer is generating lots of noise and vibration. In addition, because it is affected by Joule 's heat is used in light load conditions. As a results, the transformer vibrations at frequencies below about from 200Hz to 500Hz were detected. Vibration velocity depends on the load variations were found. Load up to approximately 20-30% in most cases the vibration velocity was found at 4,000 ${\mu}m/s$ or less, 8,000 ${\mu}m/s$ or more. Vibration frequency at light load conditions were generated at the 120Hz, 240Hz, 360Hz and 480Hz. At the load condition of from 10% to 20%, vibration velocity is higher than another. Most of the vibration velocity were identified at the 1,000 ${\mu}m/s$ or less. Using the vibration frequency and velocity measurements data, the load on the cast resin transformer analyzed the correlation of the burden. Therefore, this data could be found in the vibration characteristics of the light-load conditions. If the field measurements using the data perform diagnostics on the transformer, it's expected to be very effective.

콘크리트 코어의 강도특성에 관한 연구 (A Study on the Strength Characteristics of Concrete Cores)

  • 권영웅;이성용;신정식;전익찬;김민수;박송철
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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    • pp.85-90
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    • 2002
  • This paper concerns the within test strength of concrete cured under different conditions. Those conditions are water curing, field curing and cores drilled from the existing structures. The test factors are not only above cured conditions but also concrete ages of 3, 7, 14 and 28 days and concrete strength of 202, 252 and 650kgf/$\textrm{cm}^2$. The test results are as follows; (1) In spite of within test results, concrete strength is very different from curing states of concrete (2) The strength of cores drilled from existing structures are smaller than the strength of concrete cured in water by 3~4% and larger than that of concrete cured in field by 8~17% (3) Core strength is largely dependant on the curing state of top surface of concrete.

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간척지에서 수도 및 기타작물의 내염성에 관한 연구 2. 여러 가지 염분조건에서 배추와 양배추의 내염성에 관하여 (Study on the Salt Tolerance of Rice and Other Crops in Reclaimed 2. On the Salt Tolerance of Chinese Cabbage and Cabbage in Various Salty Conditions)

  • 임형빈
    • Journal of Plant Biology
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    • 제12권3호
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    • pp.8-14
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    • 1969
  • Salt tolerances of Chinese cabbage and cabbage were observed by means of the sand culture and field experiment. The point of 50% yield reduction of Chinese Cabbage was 1% of salt concentration in sand culture. The Na absorption in the salty upland conditions was increased but the absorption of Ca, Mg were interrupted as the salt concentration was raised and there were no differences in the absorption of N and P. The Si absorption was increased at low salty conditions, but the salt concentration was raised, the absorption was interrupted drastically. The cabbage was more stronger salt tolerance than Chinese cabbage, and it was possible to prevent the salt damage significantly by planting on sloping beds instead of planting on the double-row beds in field condition.

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경계조건에 따른 자기장 및 열하중을 받는 복합재료 원통셸의 진동해석 (Vibration Analysis of Composite Cylindrical Shells Subjected to Electromagnetic and Thermal Fields with Different Boundary Conditions)

  • 박상윤;김성균;최종운;송오섭
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2012년도 추계학술대회 논문집
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    • pp.653-660
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    • 2012
  • In this paper free vibration analysis of symmetric and cross-ply elastic laminated shells based on FSDT with two different boundary conditions(C-C, S-S) was performed through discretization of equations of motion and boundary condition. Model of laminated composite cylindrical shells subjected to a combination of magnetic and thermal fields is developed via Hamilton's variational principle. These coupled equations of motion are based on the electromagnetic equations (Faraday, Ampere, Ohm, and Lorenz equations) and thermal equations which are involved in constitutive equations. Variations of dynamic characteristics of composite shells with applied magnetic field, temperature gradient, and stacking sequence for each boundary conditions are investigated and pertinent conclusions are derived.

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