• Resources Recycling
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• v.24 no.3
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• pp.16-26
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• 2015

This study aims to suggest possible policy options for collection of post-consumer diapers as a sustainable prerequisite to implementation of public recycling system with the desktop monitoring results and analysis of collection cost involved. By conducting a diaper collection pilot test on daycare centers and households in the Seoul Nowon-gu, this study revealed that the odor issues did not stand out as an important hindering factor and that the collection rate was the largest contributing factor regarding collection costs. The exploratory cost analysis result shows that the implemented recycling system must guarantee collection rate over 50% via twice-a-week collection frequency, to be comparable or even superior to the current food waste collection cost. Also the pilot demonstration test showed that the final collection rate can be achieved as much as over 50%. The promising data thus obtained cost economically viable future diaper recycling system implementation in the entire Seoul metropolis and adjacent areas of dense population. With the concomitant development of recycling technology and related infrastructure for systematic collection of diaper waste, it makes our society much more sustainable.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.1
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• pp.41-50
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• 2010

본 논문에서는 수명이 다한 제품이나 소비자가 더 이상 사용하지 않는 폐기품을 다시 재사용하거나 폐기하는데 필요한 일련의 활동을 위한 역방향 로지스틱스에서의 수거망 설계 문제를 다루고 있다. 수거망 설계 문제는 수거지점의 위치와 수요지의 폐기품을 수거 지점에 할당하는 것을 결정하는 문제로 정의할 수 있으며 수거지점은 재활용품이나 폐기품이 위치한 지점 근처에 위치하고 주어진 잠재적인 위치를 중에서 결정하게 된다. 여기서, 각 수거지점은 용량제약이 있어 수거 지점에 할당되는 폐기품의 양에는 제한이 있다. 본 논문에서 다루는 수거망 설계문제에서는 수거지점을 설치하는데 필요한 고정비용과 수요지와 수거지점간의 수송비용의 합을 최소화하는 것을 목적으로 한다. 또한 대상문제를 보다 명확히 설명하기 위하여 징수계획법을 이용한 수리적 모형을 제안하였으며 문제의 복잡도 인하여 타부 서치와 시뮬레이티드 어닐링 두 가지 형태의 탐색기법을 제안하였다. 이들 탐색기법에 대하여 최대 500개의 잠재적 위치를 가지는 문제에 대하여 실험을 수행하였고 실험결과를 제시하였다.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.1
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• pp.13-19
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• 2018

25 local districts in Seoul have been running Waste Transfer Stations(WTSs) to secure regional collection bases, to connect between collection systems and waste treatment systems, and to commit various pre-screening of mixed wastes. There were, however, few previous researches to define how much WTSs are beneficial to waste collection system at least in Korea. So this study analyzed costs of waste collection systems with varied haul distances from waste sources(WSs) to WTS or building types of WTSs. Major results showed that the closer WTS is to WS or the cheaper the construction cost of WTS is, the lower the cost of waste collection system is. There was an additional result that WTS system with more than 15 km of total haul distance might be useful in Seoul and encapsulation of WTS in building or underground will make effective total haul distances longer up to 35km.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.2
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• pp.231-235
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• 2024

Marine debris entering through rivers negatively impacts the environment and poses a direct threat to human health. While barriers to prevent the outflow of floating debris are being installed, attention to their maintenance, especially the scheduling of garbage collection, is insufficient. Currently, maintenance relies on a sequential collection method based on the experience and know-how of field workers, with little systematic research to support it. In response, this study proposes a new feedback-based collection method based on YOLOv7, Monte Carlo simulation for trash collection analysis. The proposed method conducts collection based on the amount of trash detected by remote sensors such as CCTV, and the expected costs are statistically and economically compared using Monte Carlo Simulation (MCS). The results showed that the new collection strategy offers a cost advantage of about 63 % over the existing strategy.

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.4
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• pp.330-336
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• 2012

We surveyed and evaluated quantities and distribution characteristics of debris on the sea floor around active fishing grounds around the islands in the southwest coast of Korea in 2007 where the average depth is below 40m. Proper recovery gears mainly to haul the derelict fishing gears are selected considering the sea bed types of the areas. The collected debris amounts were used to estimate the total amount of the surveyed area. The number of hauls per trial times the amount of the debris was extended to whole sampling area and the weighting factor from the opinion was applied to reach the total amount of marine debris on the floor. The amount of the deposited marine debris around Wangdeung-do area is estimated as about 686 $kg/km^2$, and the cost of the collection and treatment for the deposited marine debris is estimated about 3.9 billion KRW after consideration of the proper size of the working ships, labor, transport and treatment cost.

• Spatial Information Research
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• v.9 no.1
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• pp.15-30
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• 2001

Solid waste collection service is viewed as one of the most important public services in urban area. The purpose of this study is to apply the GIS based regional partitioning and arc routing methods for solid waste collection districting and vehicle routing-scheduling in order to provide waste collection service more efficiently. In this study, solid waste deposit sites are derived from the centroid of each building and the amount of solid waste is deduced based on the number of households and establishments. The regional partitioning procedure is performed based on waste collection zones which are constructed from waste deposit sites. The result of this study shows that solid waste collection districts which are delineated by regional partitioning method are able to increase efficiencies and cut costs in performing solid waste collection services. Also the output of vehicle-scheduling from the analysis of arc routing may provide more efficiently and quickly manage the scheduling of the residential solid waste collection routes, reducing costs with minimal deadheading costs. Therefore, the application of GIS based on regional partitioning and arc routing methods would be very useful to construct a solid waste management system by supplying the important and flexible informations for solid waste collection districts and vehicle routing-scheduling for waste collection.

• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.35-38
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• 2011

지난 2010년 정부는 '폐기물 줄이기 종합대책'을 발표하고 체계적인 배출량 관리를 위해 RFID기반 종량제 시스템을 단계적으로 확대 구축 내용을 발표하였다. 이에 논문에서는 제안하는 시스템의 설계 개념을 확장할 수 있는 확장성과 유지보수 비용의 최소화를 위해 객체지향 설계 모델링을 활용하여 모바일기반의 RFID를 이용한 u-폐기물 통합관리 시스템을 제안한다. 제안하는 관리 시스템은 생활 및 공업 폐기물 이력관리 시스템인 통합 서버와 일반 사용자 및 폐기물 수거 차량 사용자로 구분된 클라이언트로 구현한다. 일반 사용자 시스템은 수거 용기에 부착된 태그와 단말기에 부착된 RFID 리더기를 이용하여 계근량, 수거 정보, 수거 이력정보, 수수료등을 처리하며, 해당 정보를 서버에 전송하도록 구현한다. 전송된 정보를 통하여 수거 차량 사용자의 단말기에 수거 정보를 송신해 폐기물을 수거하도록 한다.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04b
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• pp.352-354
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• 2002

메모리 재활용 방법 (gabage collection)은 안전하고 효율적이지만, 메모리를 재사용하려면 항상 메모리를 수거해야 하는 비용이 든다. 가능하면 메모리 수거없이 즉각적으로 메모리를 재사용하게 함으로써 비용을 줄일 수 있다. 본 논문에서는 실행시간 정보 전달을 통해 효과적으로 메모리를 즉각 재사용할 수 있는 방법을 제시하고, 그러한 메모리 재사용이 안전하다는 것을 증명하는 메모리 타입 시스템을 제시한다. 제시한 방법을 사용하여 프로그램 sieve를 28.1% 빠르게 실행할 수 있었다..

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.01a
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• pp.165-166
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• 2020

산업화 이후 무분별한 자원 개발로 인해 쓰레기 배출량은 증가하였으나 그 양을 감당할 쓰레기통의 개수는 부족하다. 그리고 쓰레기통이 있음에도 불구하고 시민의식 부족으로 인해 일반 쓰레기와 재활용쓰레기가 같이 버려져 있는 상태를 흔히 볼 수 있다. 작은 예로 자취하고 있는 대학생들 자취방 앞이나 상가 건물 앞에 분류되지 않고 아무렇게나 버려져있는 쓰레기들을 많이 볼 수 있다. 이는 환경 미화원이 직접 재분류를 하고 청소하는데 시간과 인력 비용이 낭비하게 된다. 본 논문은 이러한 문제점들을 개선하고 보완하고자 쓰레기를 자동으로 분리수거할 수 있는 '자동 분리수거가 가능한 쓰레기통'기술을 제안한다. 이는 분리수거율을 증가시키고 분리수거 다시 할 불필요한 시간과 인력과 예산을 줄일 수 있고 재활용된 자원을 사용하여 생산 자원을 줄여 원가 절감효과와 에너지 소비를 줄일 수 있다. 이로 인해 자원을 생산할 때 발생하는 탄소와 온실가스 방출량을 감소시켜 지구 온난화를 예방할 수 있다.

• Journal of Energy Engineering
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• v.26 no.4
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• pp.67-73
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• 2017

For the bio-fuel conversion of algae, several processes are needed including cultivating, agglomeration, extracting and conversion to the bio-fuel. The production cost for each process makes the total production cost of algae bio-fuel conversion. The production cost of algae bio-fuel has still higher than that of the other commercial bio-fuel. The reduction of production cost for each process enables the competitive price as a bio-fuel. It is difficult to separate the algae from water because of the similar magnitude of density each other. The agglomeration and extracting of algae using ultrasonic wave is rare effect of environmental hazard and also it is appropriate technology for the next generation energy resources. The present research is investigated for the elucidation of algae behavior in the water with the ultrasonics wave. For this purpose, the unsteady computational fluid dynamic analysis has been conducted in the ultrasonic pressure field. The velocity, pressure and algae concentration changes with time have been analysed to clarify the mechanism of algae separation by ultrasonic wave.