• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.621-627
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• 2001

Recycling of coal combustion by-product(Ash) are becoming more important in the utilization business as a result of the increased use of NOx reduction technologies at coal-fired power plants. current disposal methods of these by-products create not only a loss of profit for the power industry, but also environmental concerns that breed negative public opinion. Since inherent characteristics make these by-product suitable for building materials, several types of artificial aggregates and construction bricks are manufactured and tested to verify the engineering properties.

• 전기학회논문지P
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• 제59권3호
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• pp.288-292
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• 2010

Recently, in energy storage system, the EDLC is paid attention as a new environmentally friendly energy storage element. This capacitor has higher energy density than the electrolytic capacitor. Also, this capacitor has a lot of advantage such as no maintenance, longer life cycle and faster charge-discharge time than the battery system. But the EDLC must have a each charge-discharge controller to effectively control, an energy design method circuit to use effectively energy, and several compensation techniques to control a optimal operating. In this respect, this study suggests major parameters to effectively represent the characteristics of EDLC, the measurement methods of those parameters have been investigated with experiments, and the interpretation about the buck/boost DC/DC converter for the operation of EDLC.

• KIEAE Journal
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• 제7권5호
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• pp.107-114
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• 2007

This study purposed to review the alternative criteria for preserving urban scenic view and establishing its management methods by selecting preliminary viewpoints to preserve the views of woomyeon mountain. The contents of this research consists of the representative urban scenic view by analyzing its viewpoints and landscape preference. For this study, seventeen preliminary viewpoints were selected, the ratio of visual structure was calculated by types of landscapes and an analysis was conducted on landscape preference through a questionnaire survey to draw results. Conclusively, various side studies through statistical method for characteristic analysis with preference elements about viewpoint and visual structure for urban landscape management. This research will contribute to management on objective point of view in environmentally friendly urban landscape planning.

• 한국농공학회논문집
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• 제52권6호
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• pp.101-110
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• 2010

This study was performed to evaluate the void ratio and strength of porous polymer concrete used coarse aggregates and unsaturated polyester resin to find optimum mix design of porous polymer concrete for planting block. Also, this study was performed to evaluate the planting properties of herbaceous plant and cool-season grass in porous polymer blocks based on the experimental results of porous polymer concrete to develop environmentally friendly planting blocks. Tests for the void ratio and compressive strength of porous polymer concrete were performed at the curing age 7 days. Also, kinds of plants such as Tall fescue, Perennial ryegrass, Lespedeza and Alfalfa for planting were applied to porous polymer blocks. Within 6 weeks after seed, initial germination ratio, cover view and growth length for planting blocks were estimated by various methods.

• 한국정밀공학회지
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• 제23권8호
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• pp.108-118
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• 2006

Reusing is one of the most environmentally friendly recycling methods. For the economical remanufacturing of used cellular phone, the cellular phones should be design for easy disassembly. In this paper, we analyzed the components and connecting elements of cellular phones and developed a guideline for the design of the cellular phones. A software for the disassembly assessment was also developed. Redesigned cellular phone by the developed guideline and its original phone was analyzed by the disassembly assessment software. Disassembly time could be reduced about 40% and reusing rate could be improved about 37%.

• Computers and Concrete
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• 제24권4호
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• pp.295-302
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• 2019

Evolutionary algorithms based on conventional statistical methods such as regression and classification have been widely used in data mining applications. This work involves application of gene expression programming (GEP) for predicting compressive strength of fly ash geopolymer concrete, which is gaining increasing interest as an environmentally friendly alternative of Portland cement concrete. Based on 56 test results from the existing literature, a model was obtained relating the compressive strength of fly ash geopolymer concrete with the significantly influencing mix design parameters. The predictions of the model in training and validation were evaluated. The coefficient of determination ($R^2$), mean (${\mu}$) and standard deviation (${\sigma}$) were 0.89, 1.0 and 0.12 respectively, for the training set, and 0.89, 0.99 and 0.13 respectively, for the validation set. The error of prediction by the model was also evaluated and found to be very low. This indicates that the predictions of GEP model are in close agreement with the experimental results suggesting this as a promising method for compressive strength prediction of fly ash geopolymer concrete.

• Advances in nano research
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• 제10권1호
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• pp.71-76
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• 2021

Synthesis of nanoparticles using green technology using plants is gaining significant attention as it is an environmentally friendly substitute to conventional physical and chemical methods. The present study was focused on the chemical and green synthesis of Iron Oxide nanoparticles from ferric chloride. The green synthesis was achieved by utilizing the bio components of Hibiscus rosa-sinensis. The Fe3O4 nanoparticles with the size range of 87-400 nm were synthesized by wet chemical reduction technique which are unstable, prone to aggregation while in green synthesis the phytochemicals present in the leaf extract acts as the capping as well as the reducing agent thus the green synthesized iron (III) oxide nanoparticles were naturally stabilized, spherical shaped and are in the size range of 2-80 nm. The results of both the protocols are compared and presented briefly.

• Journal of Electrochemical Science and Technology
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• 제15권1호
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• pp.1-13
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• 2024

This paper presents applications of lithium-sulfur (Li-S) energy storage batteries, while showing merits and demerits of several techniques to mitigate their electrochemical challenges. Unmanned aerial vehicles, electric cars, and grid-scale energy storage systems represent main applications of Li-S batteries due to their low cost, high specific capacity, and light weight. However, polysulfide shuttle effects, low conductivities, and low coulombic efficiencies signify key challenges of Li-S batteries, causing high volumetric changes, dendritic growths, and limited cycling performances. Solid-state electrolytes, interfacial interlayers, and electrocatalysts denote promising methods to mitigate such challenges. Moreover, nanomaterials have capability to improve kinetic reactions of Li-S batteries based on several properties of nanoparticles to immobilize sulfur in cathodes, stabilizing lithium in anodes while controlling volumetric growths. Li-S energy storage technologies are able to satisfy requirements of future markets for advanced rechargeable batteries with high-power densities and low costs, considering environmentally friendly systems based on renewable energy sources.

• International journal of advanced smart convergence
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• 제13권1호
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• pp.201-205
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• 2024

Currently, the most important issue on the earth is global warming, which causes climate change and leads to disasters. For this reason, each country is focusing on renewable energy, carbon neutrality, environmentally friendly energy and transportation. Bicycles used as short-distance vehicles do not emit gases harmful to the human body that pollute the Earth's atmosphere. Also, the use of bicycles has the effect of improving the health of people, and each country is designing a short distance transportation network using bicycles. In this study, we propose a model of a bicycle power-train that can use a belt as a power transmission medium. The basic principles and methods for applying the proposed new type of power-train to bicycles are presented.

• 한국유기농업학회지
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• 제13권3호
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• pp.243-259
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• 2005

In the development of policies and projects for regional development, consolidating region's organization and organizational leadership that could establish and operate voluntary developmental plans along with active participations by regional people are important. There have been successful cases of regional agricultural products emphasizing regional characteristics by strengthening functions and autonomy of the local government based on the premise of increasing mealable relationship among local industries and maximizing the characteristics of local resources and local resource utilization. However, effective pursuing is difficult due to lack of organization and leadership. Centering around local units with their importance recognized playing the core role in the development of rural areas, other important issues are activating civic organizations essential for local development based on town units and agricultural amenity resources in rural areas by seeking methods of rearing organizational leadership, improving rural incomes by strengthening local competitiveness through environmentally-friendly agricultural products based on local units, and developing and activating farm experience related with green tour. The types of organization and leaders are analyzed by investigating approved cases of farm experience. According to the results of the analysis, we seek the methods of promoting organizations and leaders for promoting farm experiences in villages and methods of constructing support organizations for promoting farm experience centering around local government units (such as city, Kun, Eup, Myun and village).