• Environmental and Resource Economics Review
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• v.12 no.2
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• pp.275-298
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• 2003

This paper compares the economic effects of climate policy options in Korea. The impacts and implications of carbon and Btu tax schemes are analyzed using the META Net modeling system, which was developed at the Lawrence Livermore National Laboratory (LLNL). Findings indicate that carbon tax is more cost effective compared to Btu tax, but this does not necessarily mean the former is more desirable than the latter. Energy market stability and national energy security is equally important in choosing policy options. Moreover Btu tax is more effective in reducing energy consumption in general. It reduces not only carbon intensive energy sources, but non-fossil fuel like electricity. Korean economy consumes too much energy and energy efficiency is very low compared to other OECD countries. So the reduction of energy demand growth should be the first priority of the national energy policy in Korea.

• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.597-606
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• 1992

Effects of dilution rate, inlet glucose and ammonium chloride concentrations on ,he performance of continuous culture of Alcaligenes eutrQPhus for poly-p-hydroxybutyrate (PHB) production were investigated. When inlet substrate concentrations were maintained constant (inlet glucose concentration = 20 g/l, inlet ammonium chloride concentration = 2 g/l), growth rate of residual biomass and PHB production rate showed its maximum at $0.1h^{-1}$ and $0.06h^{-1}$, respectively, and washout at $0.13h^{-1}$. PHB content decreased from 50% to 25% by increasing dilution rate, while specific PHB production rate increased continuously. Cell mass and PHB concentration gave its maximum values at inlet ammonium chloride concentration of 2 g/l and thereafter decreased, which showed the existence of substrate inhibition by ammonium. When inlet glucose concentration was 30 g/l, cell mass reached its maximum value, while PHB concentration increased continuously. The parameters of kinetic model were evaluated by the graphical and parameter estimation methods. The computer simulation results for the effects of dilution rate, inlet glucose and ammonium chloride concentrations fitted the experimental data very well.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.1
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• pp.103-118
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• 2018

Ecosystems in subalpine regions are recognized as areas vulnerable to climatic changes because rainfall and the possibility of flora migration are very low due to the characteristics of topography in the regions. In this context, habitat niche was formulated for representative species of arbors in subalpine regions in order to understand the effects of climatic changes on alpine arbor ecosystems. The current potential habitats were modeled as future change areas according to the climatic change scenarios. Based on the growth conditions and environmental characteristics of the habitats, the study was conducted to identify direct and indirect causes affecting the habitat reduction of Abies nephrolepis. Diverse model algorithms for explanation of the relationship between the emergence of biological species and habitat environments were reviewed to construct the environmental data suitable for the six models(GLM, GAM, RF, MaxEnt, ANN, and SVM). Weights determined through TSS were applied to the six models for ensemble in an attempt to minimize the uncertainty of the models. Based on the current climate determined by averaging the climates over the past 30years(1981~2010) and the HadGEM-RA model was applied to fabricate bioclimatic variables for scenarios RCP 4.5 and 8.5 on the near and far future. The results of models of the alpine region tree species studied were put together and evaluated and the results indicated that a total of eight national parks such as Mt. Seorak, Odaesan, and Hallasan would be mainly affected by climatic changes. Changes in the Baekdudaegan reserves were analyzed and in the results, A. nephrolepis was predicted to be affected the most in the RCP8.5. The results of analysis as such are expected to be finally utilizable in the survey of biological species in the Korean peninsula, restoration and conservation strategies considering climatic changes as the analysis identified the degrees of impacts of climatic changes on subalpine region trees in Korean peninsula with very high conservation values.

• Science of Emotion and Sensibility
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• v.22 no.4
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• pp.85-96
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• 2019

The relative extrinsic value orientation (REVO) means the relative importance to extrinsic values (e.g. wealth, fame and social approval) compared with intrinsic values (e.g. affiliation, self-acceptance and personal growth). This study aimed to investigate the causal relation between REVO and life-satisfaction using the auto-regressive cross-lagged modeling. For this purpose, 3rd, 5th, and 7th year data from the Korea Children and Youth Panel Survey (KCYPS) middle school 1st grade panel was analyzed (N = 2,259; 1,140 males and 1,119 females). The results are as follows; Firstly, positive auto-regressive effects of REVO and life-satisfaction were significant. Secondly, REVO was found to have negative and cross-lagged effect on life-satisfaction. However, cross-lagged effect from life-satisfaction to REVO was not significant. Finally, no gender difference was found in this relationship. These results suggest that low life satisfaction does not cause the relative extrinsic value orientation, but high relative extrinsic value orientation may cause low life satisfaction.

• Korean Journal of Construction Engineering and Management
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• v.8 no.5
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• pp.119-131
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• 2007

Design build (DB) is a construction project delivery system which has become one of the favored ones and the growth of DB by the public agencies has been steadily increasing. DB can be viewed as an evolutionary project delivery system, since DB project team members collaborate on work with each other, keep seeking cost effective and innovative alternatives that meet the construction needs of the project. Thus DB outperformed others in delivery speed, cost saving, and turnover quality. In Korea, DB projects likewise have steadily increased that it is needed to analyze characteristics of DB delivery system in Korea. For that purpose, this research would offer an analysis of characteristics of DB delivery system in Korea using system dynamics model with investigating the public market trend, comparing DB performance to DBB, and analyzing questionnaire survey.

• Korean Journal of Remote Sensing
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• v.36 no.4
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• pp.515-525
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• 2020

This study investigates the potential of bidirectional long short-term memory (Bi-LSTM) for efficient modeling of temporal information in crop classification using multitemporal remote sensing images. Unlike unidirectional LSTM models that consider only either forward or backward states, Bi-LSTM could account for temporal dependency of time-series images in both forward and backward directions. This property of Bi-LSTM can be effectively applied to crop classification when it is difficult to obtain full time-series images covering the entire growth cycle of crops. The classification performance of the Bi-LSTM is compared with that of two unidirectional LSTM architectures (forward and backward) with respect to different input image combinations via a case study of crop classification in Anbadegi, Korea. When full time-series images were used as inputs for classification, the Bi-LSTM outperformed the other unidirectional LSTM architectures; however, the difference in classification accuracy from unidirectional LSTM was not substantial. On the contrary, when using multitemporal images that did not include useful information for the discrimination of crops, the Bi-LSTM could compensate for the information deficiency by including temporal information from both forward and backward states, thereby achieving the best classification accuracy, compared with the unidirectional LSTM. These case study results indicate the efficiency of the Bi-LSTM for crop classification, particularly when limited input images are available.

• Journal of Digital Convergence
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• v.10 no.4
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• pp.107-118
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• 2012

Smart TV is expected to take the center stage of the recent "smartization" trend in IT and consumer electronics as it performs a hub for various smart IT devices, such as smart phone, smart pad, PC, etc. It is distinct from traditional TVs or even IPTVs in the sense that it provides immersive and interactive experiences via apps downloaded through TV app store. Smart TV could serve as a new intermediary device between other smart devices and the Internet. While it started experiencing a rapid growth, little research has been conducted to understand this emerging technology in terms of its user acceptance and adoption by users. The current research attempts to fill the gap in the field by examining factors and processes for this new technology to be adopted by users. This paper draws on theories of IT acceptance and use, such as the "Unified Theory of Acceptance and Use of Technology", to investigate factors affecting "intention to use" of smart TV. The proposed research model is analyzed using the structural equation modeling approach. Findings show that such factors as innovativeness, switching cost, switching benefit, service interface, and user interface affect users' intention to use smart TV, through effort expectation, performance expectation, and social influence. Theoretical and managerial implications are discussed.

• Environmental Engineering Research
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• v.11 no.4
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• pp.194-200
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• 2006

Recently, the population growth, industrial and agricultural development are rapidly undergoing in the Lower Rio Grande Valley (LRGV) in Texas. The Lower Rio Grande Valley (LRGV) composed of the 4 counties and three of them are interesting for Non-point and point source pollutant modeling: Starr, Cameron, and Hidalgo. Especially, the LRGV is an intensively irrigation region, and Texas A&M University Agriculture Program and the New Mexico State University College of Agriculture applied irrigation district program, projects in GIS and Hydrology based agricultural water management systems and assessment of prioritized protecting stream network, water quality and rehabilitation based on water saving potential in Rio Grande River. In the LRGV region, where point and non-point sources of pollution may be a big concern, because increasing fertilizers and pesticides use and population cause. This project objective seeks to determine the accumulation of non-point and point source and discuss the main impacts of agriculture and environmental concern with water quality related to pesticides, fertilizer, and nutrients within LRGV region. The GIS technique is widely used and developed for the assessment of non-point source pollution in LRGV region. This project shows the losses in $kg/km^2/yr$ of BOD (Biological Oxygen Demand), TN (total Nitrogen) and TP (total phosphorus) in the runoff from the surface of LRGV. Especially, farmers in Cameron County consume a lot of fertilizer and pesticide to improve crop yield net profit. Then, this region can be created as larger nonpoint source area for nutrients and the intensity of runoff by excess irrigation water. And many sediment and used irrigation water with including high nutrients can be discharged into Rio Grade River.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.3
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• pp.243-253
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• 2020

As economic profits and social influences of firms grow with economic development and their organizational expansion, consumers increasingly require firms to have their social responsibility. Because social responsibility strongly influences corporate reliability, consumers' intention to purchase, customer loyalty to the products and the recognition of an ethical firm have gained attention as a concept of strategical importance. The prosperity of society should be proceeded for the sustainable development of a firm and the necessity of social responsibility should be emphasized to achieve virtuous circle structure that promotes growth. Additionally, the social responsibility should be proceeded to form trust on a firm. It is very important to change the recognition of consumers to purchase products and increase the profit of a company. This study aims to analyze how social responsibility properties of firms (economic, ethical, discretionary, and legal aspects as low-level factors of social responsibility which Carroll (1979) defined) affect corporate reliability and purchase intention. The analysis found that consumers trust in firms are positively influenced by ethical responsibility (0.391), economic responsibility (0.293), legal responsibility (0.251), and discretionary responsibility (0.248). The relationship between sub-factor of social responsibility and purchase intention is not significantly influenced by other explanatory variables. Corporate trust exerts a direct influence on purchase Intention (0.456). The social responsibility of a firm didn't influence a direct purchase intention. It was found that it brought positive effect on the purchase intention in the course of forming trust. This study suggests that firms should make efforts to understand the relationship between corporate trust and purchase intention along with the characteristics of social responsibility that consumers recognize and improve management strategies for mutual complementary interests.

• Advances in environmental research
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• v.1 no.1
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• pp.15-35
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• 2012

Mercury (Hg) is a global environmental pollutant that has been the cause of many public concerns. One particular concern about Hg in aquatic systems is its trophic transfer and biomagnification in food chains. For example, the Hg concentration increases with the increase of food chain level. Fish at the top of food chain can accumulate high concentrations of Hg (especially the toxic form, methylmercury, MeHg), which is then transferred to humans through seafood consumption. Various biological and physiochemical conditions can significantly affect the bioaccumulation of Hg-including both its inorganic (Hg(II)) and organic (MeHg) forms-in fish. There have been numerous measurements of Hg concentrations in marine and freshwater fish worldwide. Many of these studies have attempted to identify the processes leading to variations of Hg concentrations in fish species from different habitats. The development of a biokinetic model over the past decade has helped improve our understanding of the mechanisms underlying the bioaccumulation processes of Hg in aquatic animals. In this review, I will discuss how the biokinetic modeling approach can be used to reveal the interesting biodynamics of Hg in fish, such as the trophic transfer and exposure route of Hg(II) and MeHg, as well as growth enrichment (the increases in Hg concentration with fish size) and biomass dilution (the decreases in Hg concentration with increasing phytoplankton biomass). I will also discuss the relevance of studying the subcellular fates of Hg to predict the Hg bioaccessibility and detoxification in fish. Future challenges will be to understand the inter- and intra-species differences in Hg accumulation and the management/mitigation of Hg pollution in both marine and freshwater fish based on our knowledge of Hg biodynamics.