• Journal of Environmental Impact Assessment
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• v.8 no.1
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• pp.133-139
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• 1999

Community residents are tend to evade waste treatment facilities such as waste landfills, waste incinerators. Therefore, decision-makers of waste management are concerned about the reduction and recycling of food garbage. As a treatment alternative of food garbage which consists of 30% of municipal waste, producing compost and feed stuff from food garbage is environmentally amenable. In considering the characteristics of food garbage are putrid and high moisturized, methods of landfilling and incineration for food garbage are environmentally inadequate. For the institutionalization of food garbage recycling, separate discharge, establishment of collection system, securing of market for compost and feed stuff manufactured from food garbage, and tax and financial incentives for food garbage recycling facilities are necessary.

• Journal of Environmental Impact Assessment
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• v.8 no.2
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• pp.65-71
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• 1999

Characteristics of food garbage discharged from primary schools in Seoul Metropolitan city were analysed from a recycling point of view. The results of study are epitomized as follows : 1. Factors of generation of food garbage are mainly an unbalanced diet habit, indifference of class teachers, and worn-out cooking equipments. 2. Measures of reduction are principally a written message to parents, broadcasting in the school, and instructions. 3. Methods of recycling are mainly feed stuff, composting by school itself, composting on commission, and making feed stuff on commission. 4. Obstacles of food garbage recycling are a nasty smell of composting apparatus, an excessive fuel consumption of composting apparatus, a high concentration of salt, and an unstable demand for feed stuff and compost produced from food garbage. 5. Correlation factors are like follows : the number of feeding children and food garbage weight after cooking is 0.35, total food garbage generated and monthly treatment cost of food garbage is 0.20, individual school lunch expenses and food garbage weight after cooking is -0.10, individual school lunch expenses and food garbage generated per capita is 0.02, and individual school lunch expenses and monthly treatment cost of food garbage is 0.03.

• Journal of the Korea Organic Resources Recycling Association
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• v.6 no.2
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• pp.113-129
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• 1998

To suggest the separate collection system of garbage in household, people's disposition was evaluated. It was indicated that garbage be collected daily to minimize the odor which was major nuisance from garbage. However, most people wanted to discharge garbage in two or three days interval, as they did not prefer frequent handling. So, proper size of garbage container was determined as two to three days capacity. In contrast with it, it was major opinion that dicharged garbage should be collected everyday by local government to eliminate the outdoor pollution. Plastic bag was the most popular container, as it could be used instantly. Price of the bag affected on the efficiency of reduction and separate collection of garbage. Low price increased the separate collection and decreased the reduction, while high price introduced the opposite result. So, the dual price system was suggested to enhance both objectives.

• Journal of Environmental Policy
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• v.8 no.4
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• pp.51-73
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• 2009

Although environmental education has increased in importance, few studies have been performed on the quantitative effect of environmental education on energy-saving and garbage-reducing behavior. Accordingly, this study quantitatively analyses the effect of environmental education on energy-saving and garbage-reduction. In this study, we compared reduction in energy use and garbage production between two groups, one receiving specialized and focused environmental education, and one receiving only general environmental education. We found that focused environmental education resulted in some quantifiably positive effects in encouraging energy-saving and garbage-reducing behavior. Specifically, household energy costs and amounts of school food waste for children receiving specialized environmental training were noticeably lower than those for children receiving only general environmental education. These results suggest that enhanced environmental education policy, including the launching of an environmental model school, is needed both to reduce energy use and garbage production.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.2
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• pp.125-134
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• 2016

NAND flash memory has unique characteristics like as 'out-place-update' and limited lifetime compared with traditional storage systems. According to out-of-place update scheme, a number of invalid (or called dead) pages can be generated. In this case, garbage collection is needed to reclaim invalid pages. Because garbage collection results in not only erase operations but also copy operations of valid (or called live) pages to other blocks, many garbage collection techniques have proposed to reduce the overhead and to increase the lifetime of NAND Flash systems. This techniques sometimes select victim blocks including cold data for the wear leveling. However, most of them overlook the cost of selecting victim blocks including cold data. In this paper, we propose a garbage collection technique named CAPi (Cost Age with Proportion of invalid pages). Considering the additional overhead of what to select victim blocks including cold data, CAPi improves the response time in garbage collection and increase the lifetime in memory systems. Additionally, the proposed scheme also improves the efficiency of garbage collection by separating cold data from hot data in valid pages. In experimental evaluation, we showed that CAPi yields up to, at maximum, 73% improvement in lifetime compared with existing garbage collections.

• IEMEK Journal of Embedded Systems and Applications
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• v.12 no.3
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• pp.121-130
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• 2017

NAND flash memory has advantages of non-volatility, little power consumption and fast access time. However, it suffers from inability that does not provide to update-in-place and the erase cycle is limited. Moreover, the unit of read/write operation is a page and the unit of erase operation is a block. Therefore, erase operation is slower than other operations. The AGC, the proposed garbage collection policy focuses on not only garbage collection time reduction for real-time guarantee but also wear-leveling for a flash memory lifetime. In order to achieve above goals, we define three garbage collection operating modes: Fast Mode, Smart Mode, and Wear-leveling Mode. The proposed policy decides the garbage collection mode depending on system CPU usage rate. Fast Mode selects the dirtiest block as victim block to minimize the erase operation time. However, Smart Mode selects the victim block by reflecting the invalid page number and block erase count to minimizing the erase operation time and deviation of block erase count. Wear-leveling Mode operates similar to Smart Mode and it makes groups and relocates the pages which has the similar update time. We implemented the proposed policy and measured the performance compare with the existing policies. Simulation results show that the proposed policy performs better than Cost-benefit policy with the 55% reduction in the operation time. Also, it performs better than Greedy policy with the 87% reduction in the deviation of erase count. Most of all, the proposed policy works adaptively according to the CPU usage rate, and guarantees the real-time performance of the system.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.3
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• pp.73-80
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• 2000

The objective of study was to evaluate the apropriate maturity indices for garbage composting using sawdust as bulking agent. Materials used in this study were the average composition garbage(G20) and garbage conditioned by sawdust(GS30, GS50) and cereals(GSC30). Indices for evaluating maturity were VS, water soluble TOC, polysaccharide, Humification Index(HI), and E4/E6. Experiment results showed that VS reduction was the most desirable index for evaluating compost maturity except for the GS50 which were conditioned with high sawdust Water soluble TOC decreased rapidly during the composting of first one month and then little changed. Therefore, water soluble TOC was recommended as maturity index. Polysaccharide was considered as a maturity index in case of garbage conditioned with sawdust and high cereals. Humification Index(HI) and E4/E6 were available as maturity indices in case of only some garbage composting so additional study was needed to confirm them as maturity indices for all garbage composting. Correlation analysis indicated that indices for evaluating maturity of garbage(about 30 C/N ratio) adding sawdust as bulking agent and high cereals, were VS reduction, water soluble TOC, polysaccharide, and E4/E6.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.5
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• pp.422-428
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• 2009

NAND flash memory is widely used in embedded systems because of many attractive features, such as small size, light weight, low power consumption and fast access speed. However, it requires garbage collection, which includes erase operations. Erase operation is slower than other operations. Further, a block has a limited erase lifetime (typically 100,000) after which a block becomes unusable. The proposed garbage collection policy focuses on minimizing the total number of erase operations, the deviation value of each block and the garbage collection time. NAND flash memory consists of pages of three types, such as valid pages, invalid pages and free pages. In order to achieve above goals, we use a page ratio to decide when to do garbage collection and to select the target victimblock. Additionally, we implement allocating method and group management method. Simulation results show that the proposed policy performs better than Greedy or CAT with the maximum rate 85% of reduction in the deviation value of the erase operations and 6% reduction in garbage collection time.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.9
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• pp.617-625
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• 2009

NAND flash memory is widely used in embedded systems because of many attractive features, such as small size, light weight, low power consumption and fast access speed. However, it requires garbage collection, which includes erase operations. Erase operation is very slow. Besides, the number of the erase operations allowed to be carried out for each block is limited. The proposed garbage collection method focuses on minimizing the total number of erase operations, the deviation value of each block and the garbage collection time. NAND flash memory consists of pages of three types, such as valid pages, invalid pages and free pages. In order to achieve above goals, we use a page rate to decide when to do garbage collection and to select the target victim block. Additionally, We implement allocating method and group management method. Simulation results show that the proposed policy performs better than Greedy or CAT with the maximum rate at 82% of reduction in the deviation value of erase operation and 75% reduction in garbage collection time.

• Journal of the Korea Organic Resources Recycling Association
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• v.3 no.2
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• pp.69-78
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• 1995

When the food garbage of general hospital was dried by the rapid steam drying process, the water content was changed to 1.3% from 77.8~82.8%. In this experiment, weight reduction rate was 80%, and electricity consumption was 2.4Kwh. Dried compost from this rapid steam drying process was brown pellets, which was consist of 27.77% crude protein and 3.19% crude fiber. Even though these pellets were slightly short of crude fat and crude ash content, these were analysed as a possible supplementary feed for pig. On the condition of drying food garbage mixed with 5% pulverized chaff, the necessary drying time was shortened by 1 hour, weight reduction rate was 76%, and reduction rate of electricity consumption was 42%. But contents of crude fiber and crude ash were increased to about 2 times. In case of adding new food garbage continuously to the composted food garbage mixed with 3.4% pulverized chaff, weight reduction rate and contents of crude fiber and crude ash were decreased gradually, but contents of crude protein and crude fat were increased. In case of composting food garbage from buffet, both drying time and electricity consumption were reduced, and ingredients of compost were higher than that of assorted feed for pig in the market.