• The Journal of Korean Institute of Next Generation Computing
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• v.13 no.1
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• pp.45-53
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• 2017

The Internet of Things (IoT) technology allows devices connected to the Internet to exchange information without human intervention, and to provide useful services to people. Currently, garbage trucks are regularly dispatched to collect garbage. In such a case, garbage may be less than half of the garbage collection capacity in some area, and garbage may be exceeded in another area so that garbage trucks can not collect all at once. In this paper, we have studied the method of estimating the amount of garbage to be collected and describe the development contents of the product and management system. The prediction of garbage volume was made possible by using IoT technology to measure the volume of garbage in real time. In addition, the measurement values are visibly displayed through the dashboard, so that the amount of garbage generated can be predicted and managed. This will allow IoT technology to help keep street hygiene.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.3_4
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• pp.204-212
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• 2004

Existing distributed systems have higher probability of failures occurrence than stand-alone system, so many fault tolerant techniques have been developed. Because of insufficient storage resulting from the increased fault tolerance information stored, the performance of system has been degraded. To avoid performance degradation, it needs delete useless fault tolerance information. In this paper, we propose a garbage collection algorithm for fault tolerance information. And we define and design the garbage collection agent for garbage collection of fault tolerance information, the information agent for management of fault tolerant data, and the facilitator agent for communication between agents. Also, we propose the garbage collection algorithm using the garbage collection agent. For rollback recovery, we use independent checkpointing protocol and sender based pessimistic message logging protocol. In our proposed garbage collection algorithm, the garbage collection, information, and facilitator agent is created with process, and the information agent constructs domain knowledge with its checkpoints and non-determistic events. And the garbage collection agent decides garbage collection time, and it deletes useless fault tolerance information in cooperation with the information and facilitator agent. For propriety of proposed garbage collection technique using agents, we compare domain knowledge of system that performs garbage collection after rollback recovery and domain knowledge of system that doesn't perform garbage collection.

• The KIPS Transactions:PartA
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• v.9A no.4
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• pp.441-450
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• 2002

As the size of embedded system software increase bigger and bigger, and it's complexity is grower and grower, the usage of dynamic memory management scheme such collector also has been increased. Using the garbage collector, however, inherently lead us performance degradation. In order to resolve this kind of performance problem in the Java based embedded system. we introduce an explicit dynamic memory free method to the automated dynamic memory management environment. which can be performed by a programmer. In the worst case, the prosed scheme shows the same performance as the case of that only garbage collector is working, since the unclaimed garbage objects will eventually be collected later by the garbage collector. In the best case. our method is free from any runtime overhead because the applications can be implemented without any intervention of the garbage collector. Although the proposed method can be facilitated with all the existing garbage collection algorithms, it shows an outperform in the case of mark-and-sweep algorithm.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.672-674
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• 1998

Java virtual machine has the garbage collector that automate memory management. Mark-compact algorithm is one of the garbage collection algorithm that operating in 2 phases, marking and sweeping. One is Marking is marking live objects reachable from root object set. Sweeping is sweeping unmarked object from memory(return to free memory pool). This algorithm is easy to implement but cause a memory fragmentation. So compacting memory, before memory defragmentation become serious. When compacting memory, all other processes are suspended. It is critical for embedded system that must guarantee real-time processing. This paper introduce enhanced mark-compact garbage collection algorithm. Grouping the objects by their size that minimize memory fragmentation. Then apply smart algorithm to the grouped objects when allocating objects and compacting memory.

• 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.

• The KIPS Transactions:PartA
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• v.15A no.6
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• pp.335-344
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• 2008

We propose an adaptive garbage collection technique for hybrid flash memory which has both SLC and MLC. Since SLC area is fast and MLC area has low cost, the proposed scheme utilizes the SLC area as log buffer and the MLC area as data block. Considering the high write cost of MLC flash, the garbage collection for the SLC log buffer moves a page into the MLC data block only when the page is cold or the page migration invokes a small cost. The other pages are moved within the SLC log buffer. Also it adjusts the parameter values which determine the operation of garbage collection adaptively considering I/O pattern. From the experiments, we can know that the proposed scheme provides better performance compared with the previous flash management schemes for the hybrid flash and finds the parameter values of garbage collection close to the optimal values.

• The Journal of the Korea Contents Association
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• v.18 no.3
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• pp.101-113
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• 2018

Systems such as military inspection equipment which it is important to acquire and evaluate data in real-time should be able to real-time processing at the operating system level. As technology advances, there is a demand for replacing existing equipment with mobile device, but mobile devices with Android are not suitable for systems requiring real-time performance. On Android, garbage collection ensures free memory, while other tasks are interrupted while this task is performed, which cannot guarantee periodicity of particular tasks. In this paper, we designed and implemented a structure to control execution garbage collection of Android to solve this problem. Real-time performance is ensured by controlling garbage collection during the time required for real-time operation, and RTiK(Real-Time implanted Kernel) is applied to ensure real-time performance on Android. In order to evaluate the performance, we measured the call period of the 5ms period task, and, only 34.31% of the task was guaranteed before the control, but the task period of 98.18% was satisfied through control, providing real-time performance to Android.

• Journal of environmental and Sanitary engineering
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• v.14 no.3
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• pp.39-53
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• 1999

This thesis is to analyze and assess a new refuse collection system that was based on the term of discharge based quantity and collection of refuse from the beginning on January 1, 1995.In the case study for the refuse collection policy of metropolitan Taegu city based on the year of operation, ie, before 1994, after 1995 and as of 1998, the refuse collection policy analyzed from current position and actual condition. The results of analysis as follows. In case of discharged refuse quantity was show 20.4% reduction than the operation was begun and more 5.8% reduction as of 1998.Under the operation of the refuse collection system, therefore, management of refuse and garbage, the reduction of discharged refuse, activation of refuse collection, Recycling and expansion of financial self-reliance increased efficiency of refuse collection system. In the conclusion, more perfect refuse collection system should be developed of implemented in the near future.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.2
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• pp.315-320
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• 2009

Since flash memory can not be overwritten on updating data, new data are updated in new area and old data should be invalidated and erased for garbage collection. With develop of flash memory technology, capacity of flash memory is rapidly increasing. It increases rapidly execution time of CPU to search an entire flash memory of large capacity when choosing the block to erase in garbage collection. To solve the problem that is increasing execution time of CPU, flash memory is partitioned into several groups, the block to erase in garbage collection is searched within the corresponding group. In workload of access locality, we enhanced wear-leveling within group by allocating hot data to hot group and cold data to cold group respectively and enhanced wear-leveling among groups by exchanging periodically hot group and cold group.

• Journal of the Korean Home Economics Association
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• v.49 no.1
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• pp.41-53
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• 2011

The purpose of this paper was to examine the management of Environmentally Friendly Planning Features(EFPF) in condominium with Green Building Certification(GBC). A questionnaire survey was conducted among management office staff and residents on six housing estates in Seoul. The data from 200 respondents were analysed using descriptive statistics and t-tests. The main findings were as followings : 1) Most of the staffs considered that garbage collection and recycling, and green spaces were well-managed. 2) The residents indicated that garbage collection and recycling, and green spaces were properly handled, but they failed to recognize these as EFPF. 3) Residency duration was unrelated to the residents' perceptions of the EFPF and their management. In conclusion, neither the residents nor the staff were aware of the GBC system or that their housing estates were built using EFPF. To remedy this, it can be assumed the residents' lack of appreciation of the EFPF can be resolved if they participate in the management of these features. So the residents will need education, and the management staff will require professional training.