As in the new century, privatization has become a global trend for various public works. Garbage cleaning privatization is one major task for Taiwan EPA; all government divisions change their row from carrier to supervisor, since, the local government cans more effective in supervision and management. The results for in foreign countries have more positive effect than negative, therefore, it is expected that the privatization garbage cleaning can turn the government burden into private aid by correcting the old system. In Kaohsiung, a milestone has been set since the new mayor has subcontract the garbage cleaning to private sector. This thesis is aim for the related problems and difficulties after the garbage cleaning privatization, especially the ratio between government and private sector, from literature review, real case investigation, censer, and interview, four different approaches. The content is started with theory, definition, and foreign documents, to discuss the garbage cleaning privatization, then get into the real cases in Taiwan and other countries, and hopefully finding the best resolution for kaohsiung city in this area. At the end of this thesis, a practicable proposal for garbage cleaning privatization will be recommended based on the conclusion form survey and interview with private sectors.

Abstract Generational garbage collection is one of the most commonly used dynamic memory management techniques. Copying generational garbage collection can achieve better collection efficiency by compaction via object movement. However, object movement requires more processing overhead during collection time. Non-copying generational garbage collection eliminates the overhead of object movement. In association of with the limited memory traversal technique, it can achieve faster collection runs. But, since no compaction technique is used, poorer collection efficiency us unavoided. In addition, some in-effective design choices can greatly reduce the efficiency of generational garbage collectors. They include poor prediction of object lifetimes, unnecessarily frequent collection runs, and in-effective internal fragmentation reduction within pages, etc. In this research, we designed a user-configurable garbage collection method to improve collection efficiency and performance of current non-copy generational garbage collection method. Dynamically generated objects are characterized into four collection categories according to the usage characteristic as well as this predicted lifetimes of the objects. Our memory allocator will allocate objects to different storage heaps according to their collection categories. The four categories are: (1) short life time objects: allocated in the multiple generations, storage and collect are in the multiple ways of generation . (2) long life time objects: allocated in the single generation, storage and collect are in the single way of generation. (3) permanent life time objects: allocated in the area never been collected, the objects will occupy the space until the program terminate. (4) user-level management objects: allocated in the area never been collected, but the object will be allocated and freed by the user. For different collection categories, we separately incorportes domain-specific knowledge of memory allocation and garbage collection. We plan to restrict each garbage collection activity on its own category heap. Hence, when certain category heap needs to be collected, only a small portion of dynamic data is involved. Category-specific collection timing decision reclamation, re-allocation, and memory allocation methods can be devised for each category heap. In addition, it allows users to apply their knowledge of the program characteristics to suitabley classify the generated object's collection category to improve the collection efficiency. It also allows users to integrate direct-managed collection and automatic collection technique in one program. For performance validation, we carried out a set of performance experiments. The experiments indicate that we can reduce collection overhead and improve the average number of effective memory pages in running cases with different characteristics with our non

The provision of system-wide heap storage has a number of advantages. However, when the technique is applied to distributed systems automatically recovering inaccessible variables becomes a serious problem. This thesis presents a survey of such garbage collection techniques but finds that no existing algorithm is entirely suitable. A new, general purpose algorithm is developed and presented which allows individual systems to garbage collect largely independently. The effects of these garbage collections are combined, using recursively structured control mechanisms, to achieve garbage collection of the entire heap with the minimum of overheads. Experimental results show that new algorithm recovers most inaccessible variables more quickly than a straightforward garbage collection, giving an improved memory utilisation.

published_or_final_version / Computer Science / Master / Master of Philosophy

This thesis questions the boundaries that define waste as a public or private dilemma, investigating these boundaries as productive sites for the imagination of social life. Learning from methods of processing, conveyance and disposal, I investigate a number of possible sites where the architectural mediates the life of a wasted object and the social life that is produced around an engagement with that object. Waste has largely been disappeared from the city and the senses by mechanisms of modern sanitation and architecture, moved to the urban periphery and concealed inside increasingly refined membranes of storage and movement. Though ruptures or discrepancies in the waste stream are often read as signposts of failure of a certain project of the modern city, I read these ruptures or excesses as productive irritants for working and reworking how we conceptualize public space. It is within the friction of overlapping claims made to an issue such as waste that public life emerges.

No description available.

No description available.

No description available.

O presente trabalho busca apreender as representaÃÃes sociais de trabalhadores e trabalhadoras do lixo e suas prÃticas cotidianas, a partir da experiÃncia do Centro ComunitÃrio Santa Terezinha, com o Programa Reciclando - Rede SolidÃria de Coleta Seletiva. Parte-se do pressuposto de que as representaÃÃes sociais se constroem no cotidiano e orientam as aÃÃes das pessoas. Nesse processo de interaÃÃo entre a aÃÃo e as reflexÃes, as representaÃÃes sociais modificam as prÃticas sociais e sÃo modificadas pelas mesmas. Na reflexÃo acerca do trabalho realizado pelos agentes analisa-se a forma de ocupaÃÃo espacial que se deu no morro Santa Terezinha bem como os novos sentidos atribuÃdo Ãs vias pÃblicas como locus de trabalho e nÃo como via de acesso que se dà nos bairros nobres ao redor do Morro. A pesquisa foi realizada com agentes recicladores do referido Centro. Os agentes buscam resignificar seu trabalho atribuindo um conjunto de regras que os diferenciam dos outros profissionais que se ocupam da mesma atividade na Ãrea da pesquisa. Dessa forma estes procuram superar os preconceitos existentes em relaÃÃo à atividade da coleta. Observa-se que a coleta seletiva nÃo se dà em virtude da ausÃncia de um investimento em educaÃÃo ambiental que possibilitaria a separaÃÃo do lixo na prÃpria fonte geradora. Os poucos clientes que separam à resultado da iniciativa pontual dos agentes que negociam em alguns condomÃnios essa separaÃÃo. O cotidiano dos agentes consiste em percorrer as ruas e remexendo o lixo deixado nas calÃadas recolher o material reciclÃvel para posterior venda dos mesmos. Transitar nas ruas competindo com os carros representa um risco para os agentes. Outro risco a que estÃo submetidos à o de adquirir doenÃas em decorrÃncia do contato direto com materiais contaminados. A falta de seguranÃas trabalhistas preocupa os agentes. Acredita-se que se impostos sÃo pagos para assegurar a limpeza urbana esse trabalho deveria ser subsidiado pelo poder pÃblico de forma a garantir uma melhor condiÃÃo de vida e trabalho aos agentes. Os problemas ambientais apontam para a urgÃncia de um desenvolvimento sustentÃvel para a sociedade. EducaÃÃo ambiental e coleta seletiva do lixo sÃo instrumentos fundamentais na luta pela sustentabilidade.

Due to advances in capacity, speed, and economics, NAND-based flash memory technology is increasingly integrated into all types of computing systems, ranging from enterprise servers to embedded devices. However, due to its unpredictable up-date behavior and time consuming garbage collection mechanism, NAND-based flash memory is difficult to integrate into hard-real-time embedded systems. In this thesis, I propose a performance model for flash memory garbage collection that can be used in conjunction with a number of different garbage collection strategies. I describe how to model the cost of reactive (lazy) garbage collection and compare it to that of more proactive schemes. I develop formulas to assess the schedulability of hard real- time periodic task sets under simplified memory consumption models. Results show that I prove the proactive schemes achieve the larger maximum schedulable utilization than the traditional garbage collection mechanism for hard real-time systems in flash memory.