• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.4
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• pp.211-220
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• 2017

The application of the theoretical model to real assembly lines has been one of the biggest challenges for researchers and industrial engineers. There should be some realistic approach to achieve the conflicting objectives on real systems. Therefore, in this paper, a model is developed to synchronize a real system (A discrete event simulation model) with a theoretical model (An optimization model). This synchronization will enable the realistic optimization of systems. A job assignment model of the assembly line is formulated for the evaluation of proposed realistic optimization to achieve multiple conflicting objectives. The objectives, fluctuation in cycle time, throughput, labor cost, energy cost, teamwork and deviation in the skill level of operators have been modeled mathematically. To solve the formulated mathematical model, a multi-objective simulation integrated hybrid genetic algorithm (MO-SHGA) is proposed. In MO-SHGA each individual in each population acts as an input scenario of simulation. Also, it is very difficult to assign weights to the objective function in the traditional multi-objective GA because of pareto fronts. Therefore, we have proposed a probabilistic based linearization and multi-objective to single objective conversion method at population evolution phase. The performance of MO-SHGA is evaluated with the standard multi-objective genetic algorithm (MO-GA) with both deterministic and stochastic data settings. A case study of the goalkeeping gloves assembly line is also presented as a numerical example which is solved using MO-SHGA and MO-GA. The proposed research is useful for the development of synchronized human based assembly lines for real time monitoring, optimization, and control.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.68
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• pp.51-65
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• 2001

This study is to make LCIA(Life Cycle Impact Assessment) easier as a methodology of environmental scores(called E-score) that integrated environmental load of each emission substance based on environmental damage such as in human health, ecosystem and resources category. The concept is to analyzes the LCI(Life Cycle Inventory) and defines the level of environment damages for human health, ecosystem and resources to objective impact assessment standard, and makes the base of marginal damage to calculate the damage factor, which can present the indication that can establish the standard value of environmental impact. First, damages to human health are calculated by fate analysis, effect analysis and damage analysis to get the damage factor of health effect as a DALY(Disability Adjusted Life Years) unit. Second, damages to ecosystem are calculated by fate analysis, effect analysis and damage analysis to get the damage factor of the effect as a PDF(Potentially Disappeared Fraction) unit through linking potentially increased disappeared fraction. Third, damages to resources are carried out by resource analysis and damage analysis for linking the lower fate to surplus energy conception to get damage factor as a MJ(Mega Joule) unit. For the ranking of relative environment load level each other, LCIA can be carried out effectively by applying this E-score methodology to the particular emission substances. A case study has been introduced for the emission substances coming out of a tire manufacturer in Korea. It is to show how to work the methodology. Based on such study result, product-designers or producers now can apply the E-scores presented in this study to the substances of emission list, and then calculate the environment load of the product or process in advance at any time and can see the environment performance comparatively and expected to contribute to the environmental improvement in view of environmental pollution prevention.

• Resources Recycling
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• v.13 no.5
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• pp.3-16
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• 2004

There are over 190,000 tons per year of the sludge containing heavy metals (SHM) generated from industries in Korea. The SHM is so hazardous waste, it needs proper intermediate treatment before final disposal. At present, the common intermediate treatment and final disposal technologies of SHM are solidification and landfill. However, the future treatment and disposal technologies of SHM will be carry out to fulfill in both the environmental aspect and resource recycling. Thus, how to reduce the generation of SHM and recycle the valuable metal from SHM become the major subjects in the global world. In this article, in order to prospect the effective processing of SHM, the generation and processing of the sludge from plating wastewater, the research and development of valuable metal recycling technology and problems were summarized.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.12
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• pp.2323-2329
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• 2008

Advances in wireless communication and hardware technology have made it possible to manufacture high-performance tiny sensor nodes. More recently, the availability of inexpensive cameras modules that are able to capture multimedia data from the environment has fostered the development of Wireless Multimedia Sensor Networks(WMSNs). WMSN supplements the a advanced technique that senses, transmits, and processes the multimedia contents upon the text based traditional wireless sensor network. Since the amount of data which the multimedia contents have, is significantly larger than that of text based data, multimedia contents require lots of computing power and high network bandwidth. To process the multimedia contents on the wireless sensor node which has very limited computing power and energy, a technique for WMSN should take account of computing resource and efficient transmission. In the paper, we propose a new image compression technique YWCE for efficient compression and transmission of image data in WMSN. YWCE introduces 4 type of technique for motion estimation and compensation based on the Resolution Scalability of Wavelet. Experimental result shows that YWCE has high compression performance with different set of 4 type.

• Geophysics and Geophysical Exploration
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• v.3 no.4
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• pp.119-124
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• 2000

A new fast algorithm for travel time calculation using mono-chromatic one-way wave equation was developed based on the delta function and the logarithms of the single frequency wavefield in the frequency domain. We found an empirical relation between grid spacing and frequency by trial and error method such that we can minimize travel time error. In comparison with other methods, travel time contours obtained by solving eikonal equation and the wave front edge of the snapshot by the finite difference modeling solution agree with our algorithm. Compared to the other two methods, this algorithm computes travel time of directly transmitted wave. We demonstrated our algorithm on migration so that we obtained good section showing good agreement with original model. our results show that this new algorithm is a faster travel time calculation method of the directly transmitted wave for imaging the subsurface and the transmission tomography.

• Journal of Forest and Environmental Science
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• v.27 no.3
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• pp.143-149
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• 2011

The possibility of employing biomass of Salix viminalis cv. Q683 as a resource of bio-energy was evaluated. The chemical analysis of S. viminalis cv. Q683 leaf biomass showed components such as, extractives (2.57%), lignin (39.06%), hemicellulose (21.61%), and cellulose (37.83%), whereas, its stem was composed of extractives (1.67%), lignin (23.54%), hemicellulose (33.64%), and cellulose (42.03%). The biomass of S. viminalis cv. Q683 was saccharified using two enzymes celluclast and viscozyme. The saccharification of S. viminalis cv. Q683 biomass was influenced by enzymes and their strengths. The optimal enzyme combination was found to be celluclast (59 FPU/g substrate) and viscozyme (24 FBG/g substrate). On saccharification the glucose from leaf and stem biomass was 7.5g/L and 11.7g/L, respectively after 72 hr of enzyme treatment. The biomass and enzyme-treated biomass served as the feedstock for ethanol production by fermentation. The ethanol production from stem and leaf biomass was 5.8 g/L and 2.2 g/L respectively, while the fermentation of the enzymatic hydrolysates yielded 5 g/L to 8 g/L bioethanol in 72 hours.

• Journal of Soil and Groundwater Environment
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• v.27 no.1
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• pp.17-24
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• 2022

This work examined the effect of mixing transition metal-based additives [FeCl₃, Fe-containing paper mill sludge (PMS), CoCl₂·H₂O, ZrO₂, and α-Fe₂O₃] on the thermochemical conversion of coffee waste (CW) in carbon dioxide-assisted pyrolysis process. Compared to the generation amounts of syngas (0.7 mole% H₂ & 3.0 mole% CO) at 700℃ from single pyrolysis of CW, co-pyrolysis in the presence of Fe- or Zr-based additives resulted in the enhanced production of syngas, with the measured concentrations of H₂ and CO ranging 1.1-3.4 mole% and 4.6-13.2 mole% at the same temperature, respectively. In addition, α-Fe₂O₃ biochar possessed the adsorption capacity of As(V) (19.3 mg g^-1) comparable to that of ZrO₂-biochar (21.2 mg g^-1). In conclusion, solid-type Fe-based additive can be highly considered as an efficient catalyst to simultaneously produce syngas (H₂ & CO) as fuel energy resource and metal-biochar as sorbent.

• Journal of the Korea Convergence Society
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• v.12 no.7
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• pp.159-167
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• 2021

The increasingly severe environmental problems such as resource depletion and ecological damage, and consumers' concern for sustainable fashion, make the fashion industry chain develop towards green energy saving. The purpose of this study is to explore the attitude and consumption psychology of specific groups towards sustainable fashion consumption, as well as their specific views and attitudes towards recycled textiles or fabrics for re-manufacturing clothing. This paper attempts to understand how the characteristics of recycled clothing affect consumer. Based on the review of relevant literature, a series of determinants affecting consumer behavior is determined, and the characteristics of recycled products, such as expression value and social value, are determined. An online questionnaire was designed based on this conceptual framework, and 226 valid, complete answers were received. The results show that the emphasis on social value and environmental protection consciousness can effectively affect consumers' decision-making. These findings were helpful to the research of whole green environmental protection and ecological clothing recycling industry system, promote the sustainable development of the clothing industry.

• Journal of Korean Society of Rural Planning
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• v.30 no.1
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• pp.43-55
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• 2024

The purpose of this study is to examine residents' perspectives on factors contributing to rural decline, including population decrease and landscape degradation, with the goal of proposing strategies to revitalize rural spaces in response to these challenges. After exploring rural decline issues in Jinan, a questionnaire was developed based on a review of existing research. Following this, participants were selected, and Focus Group Interviews(FGI) were conducted. Through the analysis of the findings, strategies for local revitalization were suggested in four sectors. Based on the research findings, there is a need to reassess public transportation and vacant property projects. On the social front, preventing the misuse of rural relocation policies and enhancing residential environments through spatial clarity are essential. Environmentally, clustering renewable energy and livestock facilities and attracting educational facilities are necessary to minimize disruption to rural landscapes. From a governance perspective, fostering entrepreneurship in rural tourism and business models utilizing the local landscape is crucial for an increase in regional visits. This study holds significance by emphasizing the practical situation of rural decline, steering away from resource-centric or business-focused policies. It underscores the potential usefulness of integrating this understanding into detailed planning within policies aimed at tackling rural decline.

• Journal of the Korea Concrete Institute
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• v.21 no.3
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• pp.367-375
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• 2009

Recently, more focus is shift to imbalances in aggregate market supply and demand and an exhaustion of natural resources. In this situation, Electric arc furnace oxidizing slag (EAF slag) has high application possibility as aggregate for concrete due to similar property with general aggregate. However, it is inherent the problem which causes pop-out by free-CaO contained in slag In this study, we've got the plan to assure the chemical stability of EAF slag, and then experimentally tested the mechanical performance and durability for the fine aggregate used EAF slag. On this test result, we suggest the application plan. At the result of this study, it shows that EAF slag would reduce the surface defect such as pop-out due to natural aging for the fixed hour and adjustment the grain size of EAF slag. And mechanical performance and durability according to the replacement rate of concrete service, were revealed more than equal or equal compare to general aggregate. Hereafter, quality control must precede not to impede the beauty of concrete surface as assure the safety for aging and processing. And, to establish the environmental resource recycling system for by-products of steel, it should be made development of various application and guideline of quality control for the EAF slag aggregate. Moreover, it must be constantly studied all kind of engineering performance and durability for related to this study.