• Title/Summary/Keyword: sustained yield

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Behavior of Geosynthetic Reinforced Modular Block Walls under Sustained Loading (지속하중 재하시 보강토 옹벽의 거동특성 - 축소모형실험)

  • Yoo, Chung-Sik;Kim, Sun-Bin;Byun, Jo-Seph;Kim, Young-Hoon;Han, Dae-Hui
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.121-130
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    • 2006
  • Despite a number of advantages of reinforced earth walls over conventional concrete retaining walls, there exit concerns over long-term residual deformation when used as part of permanent structures. In view of these concerns, time-dependant deformation characteristics of geosynthetic reinforced modular block walls under sustained loads were investigated using reduced-scale model tests. The results indicated that a sustained load can yield appreciable magnitude of residual deformation, and that the magnitude of residual deformation depends on the loading characteristic as well as reinforcement stiffness.

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Research for geothermal analysis on design of Standing Column Well type system (우물관정(SCW: Standing Column Well)형 지열 냉난방 시스템 설계를 위한 지중열 해석에 관한 연구)

  • Kwon, Ik-Sang;Rhee, Kwon-Joong;Kim, Tae-Won
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.576-580
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    • 2009
  • This thesis identified basic design elements(Sustained Yield, Depth of Well, Separation Distance between wells) regarding installation of Standing Column Well, Geothermal Heat pump System by dynamic analysis.

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Application of Fuzzy Linear Programming to Estimate the Potentiality of Domestic Long-Term Wood Supply (국내 장기목재공급 잠재력 예측을 위한 퍼지선형계획법의 적용)

  • Won, Hyun-Kyu;Kim, Young-Hwan;Lee, Kyeong-Hak;Jang, Kwang-Min
    • Journal of Korean Society of Forest Science
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    • v.99 no.6
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    • pp.802-807
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    • 2010
  • The objective of this study was to estimate potential of domestic long-term wood supply by using fuzzy linear programming (FLP). In order to construct a numerical formula model, maximization of total timber production was used for the objective function. Size limit of harvesting and sustained yield were used as the constraints. The results of comparison between LP and FLP were shown that LP is more suitable than FLP in terms of the amount of timber production and final forest stock. However, as long-term sustained yield was limitedly achieved by using LP, FLP was more desirable for prediction of potential wood supply. According to the results of this study, the potential of annual domestic wood supply was estimated about 10.5 million cubic meters. Gyeong buk, Jeon nam, Gangwon and Gyeong nam province were highly ranked in order of provincial potential of wood supply.

Formulation of sustained-release matrix tablets of nifedipine (니페디핀 서방성 정제의 제제설계)

  • Cui, Yu;Kim, Seung-Su;Park, Eun-Seok;Chi, Sang-Cheol
    • Journal of Pharmaceutical Investigation
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    • v.32 no.2
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    • pp.95-101
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    • 2002
  • Matrix tablets of nifedipine (NP) were prepared with Eudragit, diluent (lactose or Ca. phosphate) and Mg. stearate employing two different preparation methods (wet granulation and direct compression) to develop its sustained-release dosage forms. The effects of various formulation factors on the dissolution rate of the drug were investigated. Dissolution test was studied in pH 6.8 phosphate buffer containing 1% sodium lauryl sulfate using the paddle method. Formulation factors were the type and content of Eudragit, the type of diluent and the tablet preparation method. The optimum formula of NP matrix tablet, which resulted in a similar dissolution profile to that from Adalat Oros used as a reference, was 30 mg NP, 10% Eudragit RS, 2% Mg. stearate and an adequate quantity of lactose to yield 500 mg weight using the wet granulation method.

Behavior of Geosynthetic Reinforced Modular Block Walls under Sustained Loading using Reduced-Scale Model Test (축소모형실험에 의한 지속하중하에서의 보강토 옹벽의 거동특성 연구)

  • Yoo, Chung-Sik;Kim, Sun-Bin;Byun, Joseph;Kim, Young-Hoon;Han, Dae-Hui
    • Journal of the Korean Geosynthetics Society
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    • v.5 no.1
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    • pp.1-7
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    • 2006
  • Despite a number of advantages of reinforced earth walls over conventional concrete retaining walls, there exit concerns over long-term residual deformation when used as part of permanent structures. In view of these concerns, time-dependant deformation characteristics of geosynthetic reinforced modular block walls under sustained loads were investigated using reduced-scale model tests. The results indicated that a sustained load can yield appreciable magnitude of residual deformation, and that the magnitude of residual deformation depends on the loading characteristic as well as reinforcement stiffness.

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Changes in Photosynthetic Characteristics during Grain Filling of a Functional Stay-Green Rice SNUSG1 and its $F_1$ Hybrids

  • Fu, Jin-Dong;Lee, Byun-Woo
    • Journal of Crop Science and Biotechnology
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    • v.11 no.1
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    • pp.75-82
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    • 2008
  • Functional stay-green is a beneficial trait that may increase grain yield through the sustained photosynthetic competence during monocarpic senescence in cereal crops. The temporal changes of photosynthesis and related characteristics throughout the grain filling period of a stay-green japonica rice "SNU-SG1" was compared in growth chamber conditions with three high-yielding cultivars(HYVs) and their $F_1$ hybrids with SNU-SG1. SNU-SG1 exhibited a typical characteristic of functional stay-green in terms of chlorophyll degradation and photosynthetic competence during grain filling. According to the photosynthesis-light response curve measured at 10 and 35 d after heading for the flag leaf, SNU-SG1 exhibited higher initial light conversion efficiency and thus higher gross photosynthetic rate at light saturation compared to HYVs. Light saturation point was not different among genotypes, ranging from 1000 to 1500 ${\mu}mol$ photon $m^{-2}s^{-1}$. Net photosynthetic rate at light saturation($P_{max}$) of the upper four leaves in SNU-SG1 was much higher and sustained longer throughout grain-filling than HYVs and $F_1$ hybrids. The sustained high photosynthetic competence of SNU-SG1 during grain filling was ascribed to the longer maintenance of high mesophyll conductance that resulted from not only high chlorophyll content and its delayed degradation but also the slow degeneration of photosystem II(PS II) as judged by chlorophyll fluorescence($F_v/F_m$) of flag leaves. $F_1$ hybrids showed slow degeneration of photosystem II similar to the male parent SNU-SG1 while chlorophyll degradation pattern close to female parents, thus exhibiting a little higher $P_{max}$ than female parents. These results suggest that SNU-SG1 has a typical functional stay-green trait that can be utilized for increasing rice yield potential through the improved dry matter production during grain filling.

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Time-dependent Deformation Characteristics of Geosynthetic Reinforced Modular Block Walls under Sustained/cyclic Loading (지속하중 및 반복하중 재하시 보강토 옹벽의 잔류변형 특성)

  • Yoo, Chung-Sik;Kim, Young-Hoon;Han, Dae-Hui;Kim, Sun-Bin
    • Journal of the Korean Geotechnical Society
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    • v.23 no.6
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    • pp.5-21
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    • 2007
  • Despite a number of advantages of reinforced earth walls over conventional concrete retaining walls, there exit concerns over long-term residual deformation when they are subjected to repeated and/or cyclic loads, especially when used as part of permanent structures. In view of these concerns, in this paper time-dependant deformation characteristics of geosynthetic reinforced modular block walls under sustained anuor repeated loads were investigated using reduced-scale model tests. The results indicated that a sustained or repeated load can yield appreciable magnitude of residual deformation, and that the residual deformations are influenced not only by the loading characteristics but by the mechanical properties of geogrid. It is also found that the preloading technique can be effectively used in controlling residual deformations of reinforced soils subjected to sustained and/or repeated loads.

Time-Dependent Deformation Characteristics of Geosynthetic-Reinforced Soil Using Plane Strain Compression Tests (평면변형압축시험을 이용한 보강토의 시간 의존적 변형 특성 연구)

  • Yoo Chung-Sik;Kim Sun-Bin;Lee Bong-Won
    • Journal of the Korean Geotechnical Society
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    • v.21 no.10
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    • pp.85-97
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    • 2005
  • Despite a number of advantages of reinforced earth walls over conventional concrete retaining walls, there exist concerns over long-term residual deformation when subjected to repeated and/or cyclic loads, especially when used as part of permanent structures. In view of these concerns, in this paper time-dependent deformation characteristics of geosynthetic reinforced soil under sustained and/or repeated loads were investigated using a series of plane strain compression tests on geogrid reinforced weathered granite soil specimens. The results indicate that sustained or repeated loads can yield appreciable magnitudes of residual deformations, and that the residual deformations are influenced not only by the loading characteristics but by the mechanical properties of geogrid. It is also found that the preloading technique can be effectively used in controlling residual deformations of reinforced soils subjected to sustained and/or repeated loads.

Analysis of Catch and Effort by Diving women in Tonggui-ri, Cheju-do (제주도 동귀 어촌계의 잠수노력량 및 어획량분석)

  • CHUNG Sang-Chul;HONG Young-ja
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.26 no.1
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    • pp.41-48
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    • 1993
  • Using the eight-year-working diaries($1984{\sim}1991$) of the fishing co-operative in Tonggui-ri, Cheju-do, as well as the records of consignment sale in the fish trust market as the corporate body in Aewol-up, the results have been analyzed as follows. 1. The monthly catch of Turbo cornutus was high from September through December, representing $58.2\%$ of the annual total catches. The maximum sustained yield(MSY) of this stock was estimated to be 2.5 tons. 2. The maximum sustained yields of Haliotis spp. and Sulculus sp. were estimated to be 800kg and 750kg, respectively. 3. The maximum sustained yields of Stichopus sp. and Octopus sp. were 500kg and 2, 500kg, respectively. 4. The total yield of Hizikia fusiforme has been decreasing a little and that of Gelidium sp. has been increasing. The total yield of Gelidium sp. in 1984 was about 5 times greater than that in 1990. 5. The daily catchability by divers have been high at thirties, and the individual mean working day of divers was 101 per year. 6. The consignment sale rates were $100\%$ each for Turbo cornutus, Hiziki fusiforme and Gelidium sp., $25.5\%$ and $61.1\%$ for Haliotis sp. and Stichopus sp. respectively, and $0\%$ each for Sulculus sp. and Octopus sp.

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Variable Density Yield Model for Irrigated Plantations of Dalbergia sissoo Grown Under Hot Arid Conditions in India

  • Tewari, Vindhya Prasad
    • Journal of Forest and Environmental Science
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    • v.28 no.4
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    • pp.205-211
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    • 2012
  • Yield tables are a frequently used data base for regional timber resource forecasting. A normal yield table is based on two independent variables, age and site (species constant), and applies to fully stocked (or normal) stands while empirical yield tables are based on average rather than fully stocked stands. Normal and empirical yield tables essentially have many limitations. The limitations of normal and empirical yield tables led to the development of variable density yield tables. Mathematical models for estimating timber yields are usually developed by fitting a suitable equation to observed data. The model is then used to predict yields for conditions resembling those of the original data set. It may be accurate for the specific conditions, but of unproven accuracy or even entirely useless in other circumstances. Thus, these models tend to be specific rather than general and require validation before applying to other areas. Dalbergia sissoo forms a major portion of irrigated plantations in the hot desert of India and is an important timber tree species where stem wood is primarily used as timber. Variable density yield model is not available for this species which is very crucial in long-term planning for managing the plantations on a sustained basis. Thus, the objective of this study was to develop variable density yield model based on the data collected from 30 sample plots of D. sissoo laid out in IGNP area of Rajasthan State (India) and measured annually for 5 years. The best approximating model was selected based on the fit statistics among the models tested in the study. The model develop was evaluated based on quantitative and qualitative statistical criteria which showed that the model is statistically sound in prediction. The model can be safely applied on D. sissooo plantations in the study area or areas having similar conditions.