• Journal of Plant Biotechnology
• /
• v.34 no.2
• /
• pp.81-93
• /
• 2007

Gas hydrates are known to form by physical interactions between host water and guest gas molecules and thus can be treated as a special type of icy materials. The gas hydrates are recently highlighted because of their use to future energy source even though they were discovered naturally in the deep-sea marine sediments a long time ago. However, the present and future urgent task is to develop the efficient and safe production technology for recovering methane from gas hydrates. Here, we propose one of potential recovery processes using swapping phenomenon occurring between gaseous carbon dioxide and methane hydrate deposits. Such a swapping process provide several technological and economical advantages over conventional processes. The carbon dioxide can be directly sequestered into methane hydrate layer and simultaneously methane can be produced with a high recovery rate more than 90%. In addition, the icy powders can be effectively used as a new medium for storing hydrogen. To increase hydrogen storage capacity the icy hydrate networks need to be redesigned to create the more empty cages in which hydrogen gas can be enclathrated. Functionalized icy materials might be used in a variety of energy and environmental fields.

• Journal of Korean Society on Water Environment
• /
• v.32 no.6
• /
• pp.511-519
• /
• 2016

National Institute of Environmental Research (NIER) has developed the Korean Reach File (KRF) for scientific and systematic analysis of variables related to water quality, pollutant sources and aquatic ecosystems in consideration of steam reach networks. The KRF provides a new framework for data production, storage, management and analysis for water related variables in relation to spatial characteristics, connections, and topologies of stream reaches. However, the current version of KRF (ver.2) has limited applicability because its nodes include not only the stream points based on topological characteristics but also those based on water quality monitoring stations, which may undermine its generality. In this study, a new version of KRF (ver.3) was designed and established to overcome the weak point of version 2. The version 3 is a generalization of the old KRF graphic data and it integrates the attribute data while separating it from the graphic data to minimize additional work that is needed for data association and search. We tested the KRF (ver.3) on actual cases and convenience and adaptability for each application was verified. Further research should focus on developing a database link model and real-world applications that are targeted to process event data.

• Journal of Science and Technology Studies
• /
• v.8 no.2
• /
• pp.1-26
• /
• 2008

This essay explores the possibility of risk epistemology based on STS perspective. The starting point is the modern society's dilemma that the more technoscience has been developed, the more modern society has become riskier. The conventional risk epistemology, based on modernist dualism, has a tendency to be negligent of the relationship between risk society and technoscience, since it has only paid attention to either side of objectivity of risk or context of risk. In contrast, STS perspective on risk makes a point of focusing on the need of constructing the comprehensive risk epistemology, instead of the traditional approach based on modernist dualism. Now, this perspective goes ahead through "bridging" between objective risk(nature) and contextual risk(society) toward co-production of risk, as a result that we can no more turn our head from the emergence of new hybrids and, in turn, increase of complexity of heterogeneous networks. As such I suggest the concept of technosphere so as to reflect and display these characteristics of this perspective, and assess the potentiality of the concept.

• Asian-Australasian Journal of Animal Sciences
• /
• v.31 no.11
• /
• pp.1700-1713
• /
• 2018

Objective: The aim of this study was to verify the usefulness of artificial neural networks (ANN), multivariate adaptive regression splines (MARS), naïve Bayes classifier (NBC), general discriminant analysis (GDA), and logistic regression (LR) for dystocia detection in Polish Holstein-Friesian Black-and-White heifers and cows and to indicate the most influential predictors of calving difficulty. Methods: A total of 1,342 and 1,699 calving records including six categorical and four continuous predictors were used. Calving category (difficult vs easy or difficult, moderate and easy) was the dependent variable. Results: The maximum sensitivity, specificity and accuracy achieved for heifers on the independent test set were 0.855 (for ANN), 0.969 (for NBC), and 0.813 (for GDA), respectively, whereas the values for cows were 0.600 (for ANN), 1.000 and 0.965 (for NBC, GDA, and LR), respectively. With the three categories of calving difficulty, the maximum overall accuracy for heifers and cows was 0.589 (for MARS) and 0.649 (for ANN), respectively. The most influential predictors for heifers were an average calving difficulty score for the dam's sire, calving age and the mean yield of the farm, where the heifer was kept, whereas for cows, these additionally included: calf sex, the difficulty of the preceding calving, and the mean daily milk yield for the preceding lactation. Conclusion: The potential application of the investigated models in dairy cattle farming requires, however, their further improvement in order to reduce the rate of dystocia misdiagnosis and to increase detection reliability.

• Journal of the Korean association of regional geographers
• /
• v.11 no.2
• /
• pp.233-246
• /
• 2005

This paper aims to explore the innovation milieu of red-pepper agro-industry in Bonghwa County, in the northern part of Gyeongbuk Province, and suggest policy recommendations for bringing up local agro-industry from a cluster perspective. It turns out that the capabilities of Bonghwa red-pepper agro-industry to innovate are remarkably weak let alone soft infrastructures such as learning networks between innovation agents and social capital. In this sense Bonghwa red-pepper agro-industry can be viewed as an agricultural area simply specialized in production sector rather than a kind of agro-industry cluster. For moving up Bonghwa red pepper industry into an innovative cluster, the paper suggests that the policy makers need to focus on cultivating local learning communities, building a region-wide incorporated brand, promoting the local agricultural technology centre as a network hub of cluster and fostering the functional links between universities and local innovation agents, covering farmers, agricultural organizations, agro-food producers and the local government.

• Journal of the Korean Geographical Society
• /
• v.38 no.4
• /
• pp.518-534
• /
• 2003

A number of previous studies have maintained that information technologies, due to their ability to overcome distance, can nurturing an innovative class of polycentric urban configurations, i.e., network cities. The present study intends to clarify whether any network relationship has recently been emerged among Korean cities by the advancement of information technology. The analyses focused on the geography of Korean national domains (.kr domains), and the hyperlink associations among three major types of domains, namely commercial, academic, and organizational domains. The study findings altogether indicate that the advancement of global economy and information era appears to be enhancing, rather than reducing the status of primate city. Seoul dominates the entire nation, forming an enclave in the production and consumption of information. Only the domains of educational institutes show network-like relations among local centers to a certain extent. The paper concludes with a discussion on the implications of the findings for future research and ‘spatial’ policy measures.

• Journal of Plant Biotechnology
• /
• v.38 no.2
• /
• pp.117-124
• /
• 2011

Considering that the world population is expected to total 9 billion by 2050, it will clearly be necessary to sustain and even accelerate the rate of improvement in crop productivity. In the 21st century, we now face another, perhaps more devastating, environmental threat, namely climate change, which could cause irreversible damage to agricultural ecosystem and loss of production potential. Enhancing intrinsic yield, plant abiotic stress tolerance, and pest and pathogen resistance through agricultural biotechnology will be a critical part of feeding, clothing, and providing energy for the human population, and overcoming climate change. Development and commercialization of genetically engineered crops have significantly contributed to increase of crop yield and farmer's income, decrease of environmental impact associated with herbicide and insecticide, and to reduction of greenhouse gas emissions from this cropping area. Advances in plant genomics, proteomics and system biology have offered an unprecedented opportunities to identify genes, pathways and networks that control agricultural important traits. Because such advances will provide further details and complete understanding of interaction of plant systems and environmental variables, biotechnology is likely to be the most prominent part of the next generation of successful agricultural industry. In this article, we review the prospects for modification of agricultural target traits by genetic engineering, including enhancement of photosynthesis, abiotic stress tolerance, and pest and pathogen resistance associated with such opportunities and challenges under climate change.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.02a
• /
• pp.556-556
• /
• 2012

Transition metal-based organometallic complexes have shown great talents as a catalyst in various reactions. Designing organic molecules and coordinating them to such active centers have been a promising route to control the catalytic natures. Metallocene, which has transition metal atoms sandwiched by aromatic rings, is one of the representative systems for organometallic catalysts. Group 4-based metallocene catalysts have been most commonly used for the production of polyolefins, which have great world-wide markets in the real life. Graphenes and carbon nanotubes (CNTs) were composed of extended $sp^2$ carbon networks, showing high electron mobility as well as have extremely large steric bulkiness relative to metal centers. We were inspired by these characteristics of such carbon-based nano-materials and assumed that they could intimately interact with active centers of metallocene catalysts. We examined this hypothesis and, recently, reported that CNTs dramatically changed catalytic natures of group 4-based catalysts when they formed hybrid systems with such catalysts. In conclusion, we produced hybrid materials composed of group-4 based metallocenes, $Cp_2ZrCl_2$ and $Cp_2TiCl_2$, and carbon-based nano-materials such as RGO and MWCNT. Such hybrids were generated via simple adsorption between Cp rings of metallocenes and graphitic surfaces of graphene/CNT. The hybrids showed interesting catalytic behaviors for ethylene polymerizations. Resulting PEs had significantly increased Mw relative to those produced from free metallocene-based catalytic systems, which are not adsorbed on carbon-based nano-materials. UHMWPEs with extremely high Mw were obtained at low Tp.

• Journal of the Korean Regional Science Association
• /
• v.32 no.4
• /
• pp.51-73
• /
• 2016

Considering the intensified ties between Korean service industry and the other industries in China and Japan, this study empirically analyzes the inter-industry network between the service industry in the Korean capital region and 10 industrial sectors in 20 city-regions of China, Japan, and Korea(CJK). Firstly, unit structures are constructed based on the estimated CJK interregional input-output tables to understand the production connection. Moreover, the reorganized unit structures are visualized as networks and examined from various angles. As the results of the analysis, the inter-industry network of the service industry in the Seoul Metropolitan Area is still mostly dependent on domestic industries, especially on manufacturing industry, while it shows the tendency to be weakly connected to the industries in Chinese and Japanese city-regions.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.15 no.4
• /
• pp.457-466
• /
• 2005

In this paper, we propose a wavelet neural network(WNN) based predictive control method for path tracking of mobile robots with multi-input and multi-output. In our control method, we use a WNN as a state predictor which combines the capability of artificial neural networks in learning processes and the capability of wavelet decomposition. A WNN predictor is tuned to minimize errors between the WNN outputs and the states of mobile robot using the gradient descent rule. And control signals, linear velocity and angular velocity, are calculated to minimize the predefined cost function using errors between the reference states and the predicted states. Through a computer simulation for the tracking performance according to varied track, we demonstrate the efficiency and the feasibility of our predictive control system.