• Title/Summary/Keyword: environmental variable

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The Effect of Environmental Regulation Considering the Endogeneity on the Productivity of Korean Manufacturing Sectors (내생성을 고려한 환경규제 강화가 우리나라 제조업 부문 생산성에 미친 영향 분석)

  • Kim, Taeyoung;Kim, Hongkyun
    • Environmental and Resource Economics Review
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    • v.26 no.4
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    • pp.473-498
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    • 2017
  • This study examines the effect of environmental regulation considering the endogeneity on the productivity of Korean manufacturing industry based on the Porter hypothesis using data from the Mining and Manufacturing Survey, Survey of Research and Development in Korea, and Environmental Statistics Portal from 2003 to 2013 with fixed effect model. In order to eliminate the bias of the missing variables that may occur in the existing studies, we analyze factors affecting productivity such as market competition, R&D investment as explanatory variables. And, in order to eliminate measurement error and inverse causality, we use instrumental variable approach. The main results are as follows. First, our findings that the environmental regulation improve the productivity of Korean manufacturing in the long-run support the Porter hypothesis. Second, our findings suggest that measurement error and reverse causality are main sources of the endogeneity, while omitted variable is not. Finally, environmental technology R&D has reduced productivity in the short-run.

Development of Environmental Control System for High-Quality Shiitake Mushroom (Lentinus edodes (Berk.) Sing.) Production

  • Kwon, Jin-Kyung;Kim, Seung-Hee;Jeon, Jong-Gil;Kang, Youn-Ku;Jang, Kab-Yeol
    • Journal of Biosystems Engineering
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    • v.43 no.4
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    • pp.342-351
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    • 2018
  • Purpose: Recently, an increasing number of farms have been cultivating shiitake mushrooms using a sawdust substrate and a cooler/heater. In this study, an attempt was made to develop an environmental control system using a heat pump for cultivating high-quality shiitake mushrooms. Methods: An environmental control system, consisting of an air-to-water type heat pump, a thermal storage tank, and a radiator in a variable opening chamber, was designed and fabricated. The system was also installed in the cultivation facility of a farm cultivating shiitake mushrooms so as to compare the proposed control system with a conventional environmental control system using a cooler-condensing unit and an electric hot water boiler. Results: The uniformity of the environment was analyzed through environment measurements taken at several positions inside the cultivation facility. It was determined that the developed environmental control system is able to control the variations in temperature and relative humidity to within 1% and 3%, respectively. In addition, a maximum temperature difference of $30^{\circ}C$ (maximum of $35^{\circ}C$, minimum of $5^{\circ}C$) and a maximum relative humidity difference of 30% (maximum of 90%, minimum of 60%) can be attained within 30 min inside the cultivation facility through the cooling of the heat pump and heating of the radiator in a variable opening chamber. Thus, the developed control system can be used to cultivate high-quality shiitake mushrooms more effectively than a conventional cooler and heater. Conclusions: In comparison with a conventional environmental control system, the developed system decreased the yield of ordinary mushrooms by 65%, and increased that of high-quality mushrooms by 217%. This corresponds to a 16% increase in gross farm income. Consequently, the developed system is expected to improve the income of shiitake mushroom cultivating farms.

Typical Consideration On The Basic Model of Decision Making (의사결정의 기본 MODEL에 관한 유형적 고찰)

  • 김면성
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.6 no.9
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    • pp.111-124
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    • 1983
  • The basic model of decision problem the enterprise is conforonted with includes the following 3 elements ; 1) Elements that can not be controlled by the decision maker : In the thesis elements are named environmental variables, and varied itself according to the change of environmental condition. 2) Elements that can be controlled by the decision maker ; These elements are called decision elements in the thesis and variable according to the event. 3) object of decision making : The degree of achievement to the object is identified by taking various criteria- The index indicating the degree of achievement to the object whatever criterion is applied is called object function in the thesis. It's the fanetion of environmental variable, decision variable and object function. The relation between them brings forth the relation formula that characterize the each problem. The basic types of decision making model use in the thesis are as following ; 1) The problem of decision making under conditions of certainty. 2) The problem of decision making under conditions of risk. 3) The problem of decision making under conditions of uncertainty. 4) The problem of decision making under competitive condition. in general case that the Profit of two decision makers varies, what we regard the decision that make the sum of profit of two men maximum as the best choice for two men has a reasonability in certain case. When the sum of profit two men is zero, by taking toe promise that ail of them art according to the min-max criteria and by extending the object of choice to the mixed strategy. We certify the existance of equilibrium solution and admit them as the best solution of competitive model in general.

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The Relationship among Adolescents' Environmental Experience, Environmental Consciousness and Pro-environmental Consumption Behavior (청소년의 환경체험활동경험, 환경의식 그리고 환경친화적 소비행동의 관계)

  • Jung, Joo Won;Cho, So Yeon
    • Journal of Environmental Science International
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    • v.24 no.3
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    • pp.329-337
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    • 2015
  • The purpose of this study was to observe the influence adolescents' environmental experience and environmental consciousness have on the pro-environmental consumption behavior. Also by examining the variable relation, the study scoped out the effectiveness of environmental experience. For the analysis, high school students in Korea were gathered from online and the correlation analysis, multiple regression analysis, and Baron and Kenny mediation analysis were conducted among a total of 521 surveys. The main findings are as follows: First, adolescents' environmental experience, environmental consciousness and pro-environmental consumption behavior showed a positive relationship. In other words, the more the experience, the more sense of responsibility adolescents had towards the environment and society, leading them to have pro-environmental consumption behavior. Second, environmental experience and environmental consciousness were proven to be essential factors that have influence on the adolescents' pro-environmental consumption behavior. Third, partial mediating effect of environmental consciousness was verified in accordance with the relationship between environmental experience and pro-environmental consumption behaviour. The findings suggest the importance of adolescents' environmental consciousness and improvement of pro-environmental consumption behavior by having students gain environmental experience.

Optimal placement of viscoelastic dampers and supporting members under variable critical excitations

  • Fujita, Kohei;Moustafa, Abbas;Takewaki, Izuru
    • Earthquakes and Structures
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    • v.1 no.1
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    • pp.43-67
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    • 2010
  • A gradient-based evolutionary optimization methodology is presented for finding the optimal design of both the added dampers and their supporting members to minimize an objective function of a linear multi-storey structure subjected to the critical ground acceleration. The objective function is taken as the sum of the stochastic interstorey drifts. A frequency-dependent viscoelastic damper and the supporting member are treated as a vibration control device. Due to the added stiffness by the supplemental viscoelastic damper, the variable critical excitation needs to be updated simultaneously within the evolutionary phase of the optimal damper placement. Two different models of the entire damper unit are investigated. The first model is a detailed model referred to as "the 3N model" where the relative displacement in each component (i.e., the spring and the dashpot) of the damper unit is defined. The second model is a simpler model referred to as "the N model" where the entire damper unit is converted into an equivalent frequency-dependent Kelvin-Voigt model. Numerical analyses for 3 and 10-storey building models are conducted to investigate the characters of the optimal design using these models and to examine the validity of the proposed technique.

Modified Probabilistic Neural Network of Heterogeneous Probabilistic Density Functions for the Estimation of Concrete Strength

  • Kim, Doo-Kie;Kim, Hee-Joong;Chang, Sang-Kil;Chang, Seong-Kyu
    • International Journal of Concrete Structures and Materials
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    • v.19 no.1E
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    • pp.11-16
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    • 2007
  • Recently, probabilistic neural network (PNN) has been proposed to predict the compressive strength of concrete for the known effect of improvement on PNN by the iteration method. However, an empirical method has been incorporated in the PNN technique to specify its smoothing parameter, which causes significant uncertainty in predicting the compressive strength of concrete. In this study, a modified probabilistic neural network (MPNN) approach is hence proposed. The global probability density function (PDF) of variables is reflected by summing the heterogeneous local PDFs which are automatically determined by the individual standard deviation of each variable. The proposed MPNN is applied to predict the compressive strength of concrete using actual test data from a concrete company. The estimated results of MPNN are compared with those of the conventional PNN. MPNN showed better results than the conventional PNN in predicting the compressive strength of concrete and provided promising results for the probabilistic approach to predict the concrete strength by using the individual standard deviation of a variable.

Sensibility Preference of Eco-Friendly Fabric Products and Trust Reliability (친환경 섬유의류 제품의 감성 선호도와 신뢰도 조사 연구)

  • Na, Young-Joo;Kim, Hyo-Won
    • Fashion & Textile Research Journal
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    • v.14 no.3
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    • pp.430-437
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    • 2012
  • This study analyzed the sensibility of eco-friendly fabrics for college students and investigated their attitude on environmental problems, trust reliability onto eco-apparel products, and their purchase state. We tested 6 eco-friendly fabrics (recycled polyester, organic cotton, green tea, charcoal, bamboo, and nettle) through a survey using the Likert scale of 12 polar sensibility words. Most fabrics showed feelings that were smooth, natural, female, and country these were followed by fashion, cheap, functional, sustainable, warm, and vintage. In addition, nettle fabric showed 'rough' feeling, and recycled polyester fabric showed an 'artificial' feeling. Correspondence analysis showed the distance and direction between fabric types and sensibility words with a 2D diagram where the X axis was named with 'Soft <-> Hard' and Y axis was with 'Environmental <-> Manmade' to represent the relationship between fabric types and the sensibility words. According to the results of the multiple regression analysis, the cognition level of the consumer for environmental problems was found to be the most influential variable on the loyalty purchase of eco-friendly products; however, the trust reliability level of consumer onto eco-friendly apparel products was found to be the most influential variable on the conditional purchase of eco-friendly apparel products.

Environmental Consciousness and Environmental Management Performance: The Mediating Effect of Environmental Information Sharing

  • KIM, Minkyung;HA, Byoung-Chun
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.8
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    • pp.57-69
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    • 2022
  • The purpose of the study is to empirically investigate the effect of suppliers' environmental consciousness on environmental information sharing and management performance and to conduct the mediating effect of environmental information sharing between the environmental consciousness of suppliers and environmental management performance. The scope of environmental consciousness was extended from the consumer perspective to the organizational perspective and proposed a variable called environmental information sharing to explain how environmental consciousness affects environmental management performance. The research model and hypotheses were established based on previous studies. After collecting 295 samples of effective responses from suppliers, an empirical analysis was conducted using structural equation modeling. The findings show that suppliers' environmental consciousness affects environmental information sharing and management performance, and such sharing has a mediating effect on the relationship between suppliers' environmental consciousness and environmental management performance. The fact that environmental consciousness affects environmental management performance indicates that environmental consciousness is not just a concept of values such as the firm's belief or will, but a part of the firm's actual goal of performance. Therefore, suppliers have difficulties in reality such as a lack of professional manpower or guideline, but it is necessary to enhance the importance of environmental consciousness and promote environmental information sharing.

A Study on the Application of Variable Speed Limits(VSL) for Preventing Accidents on Freeways (고속도로 교통사고 예방을 위한 가변제한속도 적용방안 연구)

  • Park, Joon-Hyung;Hwang, Hyo-Won;Oh, Cheol;Chang, Myung-Soon
    • Journal of Korean Society of Transportation
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    • v.26 no.4
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    • pp.111-121
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    • 2008
  • Using variable speed limits (VSL) is a key strategy for preventing traffic accidents and alleviating traffic congestion. This study proposes an algorithm to operate VSLs on freeways for traffic safety. The proposed algorithm consists of two components based on accident likelihood estimation and analysis of safe stopping distance under various environmental conditions. A binary logistic regression technique is used for estimating accident likelihood. It is expected that the proposed algorithm would be successfully applied in practice in support of an integrated traffic and environmental condition monitoring system. Technical issues associated with the field implementation are also discussed.

The optimal balance between sexual and asexual reproduction in variable environments: a systematic review

  • Yang, Yun Young;Kim, Jae Geun
    • Journal of Ecology and Environment
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    • v.40 no.2
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    • pp.89-106
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    • 2016
  • Many plant species have two modes of reproduction: sexual and asexual. Both modes of reproduction have often been viewed as adaptations to temporally or spatially variable environments. The plant should adjust partitioning to match changes in the estimated success of the two reproductive modes. Perennial plants showed that favorable habitats in soil nutrients or water content tend to promote clonal growth over sexual reproduction. In contrast, under high light-quantity conditions, clonal plants tend to allocate more biomass to sexual reproduction and less to clonal propagation. On the other hand, plants with chasmogamous and cleistogamous flowers provides with a greater tendency of the opportunity to ensure some seed set in any stressful environmental conditions such as low light, low soil nutrients, or low soil moisture. It is considered that vegetative reproduction has high competitive ability and is the major means to expand established population of perennial plants, whereas cleistogamous reproduction is insurance to persist in stressful sites due to being strong. Chasmogamous reproduction mainly enhances established and new population. Therefore, the functions of sexual and asexual propagules of perennial or annual plants differ from each other. These traits of propagule thus determine its success at a particular region of any environmental gradients. Eventually, if environmental resources or stress levels change in either space or time, species composition will probably also change. The reason based on which the plants differ with respect to favored reproduction modes in each environmental condition, may be involved in their specific realized niche.