• Title/Summary/Keyword: management regimes

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High Temperature Drying of North American Ginseng for Management Decision Making

  • Bailey, W.G.;Dalfsen, K.B.van;Guo, Y.P.
    • Journal of Ginseng Research
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    • v.27 no.3
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    • pp.141-145
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    • 2003
  • The multi-year production cycle for ginseng can be rapidly depreciated by inferior post-harvest activities. This research examines the character of high temperature drying regimes for North American ginseng root to assist management decision making. The objective is a very rapid drying regime, that will not result in physical or chemical damage to the root and that would not alter the actual dry root weight. Research is presented using drying temperatures of 55, 70 and 105 C. Temperatures above these rapidly cause substantive physical damage to the root samples and seriously compromise the dry root values determined. Temperatures below these behaved quite similar to actual dryer regimes (approximately 38 C). Laboratory results indicate that there are differences between the three temperature regimes tested. Careful usage of the 70 C regime, over a period of two to three days in a convection drying oven, has distinct merit.

Anaerobic digestion of food waste to methane at various organic loading rates (OLRs) and hydraulic retention times (HRTs): Thermophilic vs. mesophilic regimes

  • Kumar, Gopalakrishnan;Sivagurunathan, Periyasamy;Park, Jong-Hun;Kim, Sang-Hyoun
    • Environmental Engineering Research
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    • v.21 no.1
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    • pp.69-73
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    • 2016
  • Generation of food waste is a serious issue that needs to be addressed worldwide. Developing suitable treatment methods while generating energy (methane) is a common practice for sustainable treatment of waste. In this study, methane generation by food waste was investigated in mesophilic and thermophilic regimes at various hydraulic retention times (HRTs) and organic loading rates (OLR). In temperature regimes, influent concentrations and HRTs ranged from 30 to 110 g COD/L and 18 to 30 days, respectively, which corresponding to an OLR of 1.0 to $6.1kg\;COD/m^3-d$. Better methane production and organic removal was observed under thermophilic conditions because of the enhanced hydrolysis of complex polymers and microbial activity at higher temperature. The peak methane productivities attained in thermophilic and mesophilic regimes were 1.30 and $0.99m^3/m^3-d$, respectively. The maximum methane yields were achieved at 50 g COD/L and HRT of 24 d in both cases, and the values were 264 and $221m^3/ton$ COD, respectively. The results of this study will facilitate the development of sustainable methane production technologies using food waste as a feedstock.

International Ocean Issues and Policy Regime (국제 해양환경안전 이슈와 정책레짐 변화)

  • Choi Sung-Doo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.12 no.2 s.25
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    • pp.115-123
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    • 2006
  • The policy regime of ocean is changed from ocean liberty paradigm to ocean management paradigm. Ocean resources have the characteristics of weak excludability and strong rivalry. Therefore, they need rational ocean management so as to curb the tragedy of commons. The important ocean issues and policy regimes today is ocean pollution, coastal management, sea-level rise, fishery, whaling, ocean jurisdictions, deep seabed resources, military security, piracy, ecological environmental security and so on. This paper aims at reviewing these major international ocean issues, the policy regimes for them, and the desirable tasks of ocean policy regimes in the future from the macro perspective of international ocean politics or policy-making.

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Performance Analysis of Neural Network on Determining The Optimal Stand Management Regimes (임분의 적정 시업체계분석을 위한 Neural Network 기법의 적용성 검토)

  • Chung, Joo Sang;Roise, Joseph P.
    • Journal of Korean Society of Forest Science
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    • v.84 no.1
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    • pp.63-70
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    • 1995
  • This paper discusses applications of neural network to stand stocking control problems. The scope of this research was to develop a neural network model for finding optimal stand management regimes and examining the performance of the model for field application. Performance was analyzed in consideration of the number of training examples and structural aspects of neural network. Research on network performance was based on extensive optimization studies for pure longleaf pine(Pinus palustris) stands. For experimental purposes. an existing nonlinear even-aged stand optimization model with a whole-stand growth and yield simulator was used to generate data samples required for the performance analysis.

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Analysis of Optimal Thinning Prescriptions for a Cryptomeria japonica Stand Using Dynamic Programming (동적계획법 적용에 의한 삼나무 임분의 간벌시업체계 분석)

  • Han, Hee;Kwon, Kibeom;Chung, Hyejean;Seol, Ara;Chung, Joosang
    • Journal of Korean Society of Forest Science
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    • v.104 no.4
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    • pp.649-656
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    • 2015
  • The objective of this study was to analyze the optimal thinning regimes for timber or carbon managements in Cryptomeria japonica stands of Hannam Experimental Forest, Korea Forest Research Institute. In solving the problem, PATH algorithm, developed by Paderes and Brodie, was used as the decision-making tool and the individual-tree/distance-free stand growth simulator for the species, developed by Kwon et al., was used to predict the stand growth associated with density control by thinning regimes and mortality. The results of this study indicate that the timber management for maximum net present value (NPV) needs less number of but higher intensity thinnings than the carbon management for maximum carbon absorption does. In case of carbon management, the amount of carbon absorption is bigger than that of timber management by about 6% but NPV is reduced by about 3.2%. On the other hand, intensive forest managements with thinning regimes promotes net income and carbon absorption by about 60% compared with those of the do-nothing option.

The effect of combined carbonation and steam curing on the microstructural evolution and mechanical properties of Portland cement concrete

  • Kim, Seonhyeok;Amr, Issam T.;Fadhel, Bandar A.;Bamagain, Rami A.;Hunaidy, Ali S.;Park, Solmoi;Seo, Joonho;Lee, H.K.
    • Advances in concrete construction
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    • v.11 no.5
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    • pp.367-374
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    • 2021
  • The present study investigated the effect of the combined carbonation and steam curing on the physicochemical properties and CO2 uptake of the Portland cement concrete. Four different curing regimes were adopted during the initial 10 h of curing to evaluate the potential of carbonation curing as an alternative to conventional steam curing in the precast concrete industry from environmental and practical viewpoints. Four combinations of carbonation and steam curing conditions were applied as curing regimes to the samples at an early age. The test results indicated that the samples treated with the combined carbonation and steam curing exhibited higher early strength development compared to the other samples, signifying that carbonation curing can reduce the production time of precast concrete. Furthermore, the CO2 uptake capacity of the samples was calculated and found to be as high as 18% with respect to the mass of the paste samples. Hence, the simultaneous utilization of steam and CO2 for the fabrication of precast concrete members has the potential to make precast concrete greener and more cost-effective.

Assessment of Biomass and Carbon Stock in Sal (Shorea robusta Gaertn.) Forests under Two Management Regimes in Tripura, Northeast India

  • Banik, Biplab;Deb, Dipankar;Deb, Sourabh;Datta, B.K.
    • Journal of Forest and Environmental Science
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    • v.34 no.3
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    • pp.209-223
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    • 2018
  • We investigated tree composition, stand characteristics, biomass allocation pattern and carbon storage variability in Sal forests (Shorea robusta Garten.) under two forest management regimes (Sal forest and Sal plantation) in Tripura, Northeast India. The results revealed higher species richness (29 species), stand density of $1060.00{\pm}11.12stems\;ha^{-1}$ and diversity index ($1.90{\pm}0.08$) in Sal forest. and lower species richness (4 species), stand density of $ 230.00{\pm}37.22stems\;ha^{-1}$ and diversity index ($0.38{\pm}0.15$) in Sal plantation. The total basal cover $33.02{\pm}4.87m^2ha^{-1}$) and dominance ($0.76{\pm}0.08$) were found higher in Sal plantation than the Sal forest ($22.53{\pm}0.38m^2ha^{-1}$ and $0.23{\pm}0.02$ respectively). The total vegetation carbon density was recorded higher in Sal plantation ($219.68{\pm}19.65Mg\;ha^{-1}$) than the Sal forest ($167.64{\pm}16.73Mg\;ha^{-1}$). The carbon density estimates acquired in this study suggest that Sal plantation in Tripura has the potentiality to store a large amount of atmospheric carbon inspite of a very low species diversity. However, Sal forests has also an impending sink of carbon due to presence of large number of young trees.

Xylem Sap Flow Affected by Short-term Variation of Soil Moisture Regimes at Higher Growth Period in 'Fuji'/M.9 Apple Trees with Different Fruit Loads (착과량 수준 및 생육성기 토양수분 함량 변화에 따른 '후지'/M.9 품종의 수액이동 특성)

  • Park, Jeong-Gwan;Kim, Seung-Heui;Lee, In-Bok;Park, Jin-Myeon
    • Korean Journal of Environmental Agriculture
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    • v.25 no.2
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    • pp.164-169
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    • 2006
  • This study was conducted for 10 days from 17 July to 26 July in 2005 to measure the amount of xylem sap flow under short-term variation of soil moisture regimes at -20 kPa, -50 kPa and -80 kPa in eight-year-old 'Fuji'/M.9 apple trees with different fruit loads. Fruit load was adjusted as three different treatments with standard (100%), 1/2 times (50%) and 2 times (200%) on the basis of optimum fruiting number per tree as the standard fruit load of Fuji cultivar. Trees with standard fruit load during the experimental period showed higher xylem sap flow at -50 kPa of soil moisture regimes than those of trees with 1/2 times and 2 times fruit load. Trees with 1/2 times and 2 times fruit load had similar patterns of the diurnal changes of xylem sap flow, vapor pressure deficit (VPD), and maximum evapotranspiration (ETm). However, trees with 2 times fruit load at -50 kPa and -80 kPa of soil moisture regimes produced lower amount of xylem sap flow than ETm. Trees with standard fruit load produced $1.06{\sim}3.93$ L/tree more amount of xylem sap flow than ETm at all soil moisture regimes. But xylem sap flow of tees with 2 times fruit load had 21% lower at -50 kPa and $31{\sim}36%$ lower at -20 kPa and -80 kPa of soil moisture regimes, respectively than that of trees with standard fruit load. Shoot growth and leaf area were significantly the highest in trees with standard fruit load while those of trees with 2 times fruit load recorded significantly lowest. Leaf water potential of trees with standard fruit load was lower than that of trees with 1/2 times and 2 times fruit load. It indicated that tees with standard fruit load had higher water use for transpiration than other treatments and tees with 2 times fruit load received more stress for the transpiration process under low soil moisture regimes. Consequently, 'Fuji'/M.9 apple trees, the fruit load and soil moisture should be maintained optimum to increase xylem sap flow and transpiration during higher growth period.

Numerical Analysis of Stress Regimes in and around Inactive and Active Fault Zones (비활성 그리고 활성 단층지역 내부와 주변에서의 응력장에 대한 수치적 분석)

  • Jeong, Woo-Chang;Song, Jai-Woo
    • Journal of the Korean Society of Hazard Mitigation
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    • v.1 no.1 s.1
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    • pp.117-125
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    • 2001
  • This paper presented the analysis of stress regimes in and around inactive and active fault zones. The stress regime in the vicinity of an existing inactive fault zone is dependent on the orientation of the fault with respect to the current stress field and the contrast between the elastic properties of the faulted rock and those of the surrounding rock. In the analysis of stress regimes around an active fault zone, if the yielding stress is exceeded during loading, the localized shearing in a fault zone will result in weakness with mean stresses in the fault becoming lower than those in the surrounding rock. It can be expected that such stress gradients will induce fluid flow towards the faults zone.

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The Commercialization of Academic Research in the Context of Shifting Intellectual Property Regimes in the Twentieth Century (20세기 대학연구의 상업화와 지적재산권 제도의 변화)

  • Yi, Doogab
    • Korean Journal of Environmental Biology
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    • v.32 no.4
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    • pp.403-412
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    • 2014
  • This article chronicles key shifts in intellectual property regimes in the twentieth century as they related to the commercialization of academic research. The institutionalization and growth of scientific research in the research university in the twentieth century and the increasing awareness of its potential to promote technology innovation and economic growth posited an important question of the ownership of knowledge created in the academic setting, where knowledge was traditionally regarded as a common property among academic researchers. This paper shows the ownership of academic knowledge emerged as a key public policy and legal issue in the latter half of the twentieth century for academic researchers and government officials who pursue the commercialization of academic knowledge for private gain and public benefit. The resulting institutionalization of patent management in the research university and shifts in federal patent policy in turn opened a new legal avenue for the establishment of the private ownership of academic knowledge and the expansion of intellectual property rights in academia, especially in the area of biological and biomedical research. Reflecting upon historical shifts in intellectual property regimes in the twentieth century, this paper suggests recent controversies regarding ownership of biological knowledge and profit sharing in developing counties are linked to critical issues pertinent to the welfare of indigenous population, utilization of new natural resources, and sustainable development for humanity.