• International journal of advanced smart convergence
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• v.12 no.4
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• pp.164-170
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• 2023

With the recent advances in AI (artificial intelligence) and HPC (high-performance computing) technologies, deep learning is proliferated in various domains of the 4th industrial revolution. As the workload volume of deep learning increasingly grows, analyzing the memory reference characteristics becomes important. In this article, we analyze the memory reference traces of deep learning workloads in comparison with traditional workloads specially focusing on read and write operations. Based on our analysis, we observe some unique characteristics of deep learning memory references that are quite different from traditional workloads. First, when comparing instruction and data references, instruction reference accounts for a little portion in deep learning workloads. Second, when comparing read and write, write reference accounts for a majority of memory references, which is also different from traditional workloads. Third, although write references are dominant, it exhibits low reference skewness compared to traditional workloads. Specifically, the skew factor of write references is small compared to traditional workloads. We expect that the analysis performed in this article will be helpful in efficiently designing memory management systems for deep learning workloads.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.3
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• pp.336-340
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• 2010

Flash storages are prevalent as portable storage in computing systems. When we consider the detachability of Flash storage devices, data integrity becomes an important issue. To assure extreme data integrity, file systems synchronously write all file data to storage accompanying hot write references. In this study, we concentrate on the effect of hot write references on Flash storage, and we consider the effect of absorbing the hot write references via nonvolatile write cache on the performance of the FTL schemes in Flash storage. In 80 doing, we quantify the performance of typical FTL schemes for workloads that contain hot write references through a wide range of experiments on a real system environment. Through the results, we conclude that the impact of the underlying FTL schemes on the performance of Flash storage is dramatically reduced by absorbing the hot write references via nonvolatile write cache.

• Journal of Computing Science and Engineering
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• v.8 no.3
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• pp.157-172
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• 2014

Contemporary embedded systems often use NAND flash memory instead of hard disks as their swap space of virtual memory. Since the read/write characteristics of NAND flash memory are very different from those of hard disks, an efficient page replacement algorithm is needed for this environment. Our analysis shows that temporal locality is dominant in virtual memory references but that is not the case for write references, when the read and write references are monitored separately. Based on this observation, we present a new page replacement algorithm that uses different strategies for read and write operations in predicting the re-reference likelihood of pages. For read operations, only temporal locality is used; but for write operations, both write frequency and temporal locality are used. The algorithm logically partitions the memory space into read and write areas to keep track of their reference patterns precisely, and then dynamically adjusts their size based on their reference patterns and I/O costs. Without requiring any external parameter to tune, the proposed algorithm outperforms CLOCK, CAR, and CFLRU by 20%-66%. It also supports optimized implementations for virtual memory systems.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.1
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• pp.71-76
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• 2023

Recently, a memory management strategy that utilizes read and write references separately is attracting attention. This is due to the emergence of new storage media with asymmetric read/write latencies and different read/write access characteristics of software. Existing research assumes that operating systems can differentiate between read/write references that occur on each memory page, but most memory architectures do not support a way to distinguish them. Unlike previous studies, this paper proposes a software method that reflects the read/write characteristics of page references by utilizing the reference and modified bits of each page. Simulations show that the proposed policy has almost similar effects to existing studies with hardware support.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.6
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• pp.543-556
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• 2009

Recently, NAND flash memory is being used as the swap device of virtual memory as well as the file storage of mobile systems. Since temporal locality is dominant in page references of virtual memory, LRU and its approximated CLOCK algorithms are widely used. However, cost of a write operation in flash memory is much larger than that of a read operation, and thus a page replacement algorithm should consider this factor. This paper analyzes virtual memory read/write reference patterns individually, and observes the ranking inversion problem of temporal locality in write references which is not observed in read references. With this observation, we present a new page replacement algorithm considering write frequency as well as temporal locality in estimating write reference behaviors. This new algorithm dynamically allocates memory space to read/write operations based on their reference patterns and I/O costs. Though the algorithm has no external parameter to tune, it supports optimized implementations for virtual memory systems, and also performs 20-66% better than CLOCK, CAR, and CFLRU algorithms.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.2
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• pp.223-231
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• 2015

As smartphones support a variety of applications and their memory demand keeps increasing, the design of an efficient memory management policy is becoming increasingly important. Meanwhile, as nonvolatile memory (NVM) technologies such as PCM and STT-MRAM have emerged as new memory media of smartphones, characterizing memory references for NVM-based smartphone memory systems is needed. For the deep understanding of memory access features in smartphones, this paper performs comprehensive analysis of memory references for various smartphone applications. We first analyze the temporal locality and frequency of memory reference behaviors to quantify the effects of the two properties with respect to the re-reference likelihood of pages. We also analyze the skewed popularity of memory references and model it as a Zipf-like distribution. We expect that the result of this study will be a good guidance to design an efficient memory management policy for future smartphones.

• Journal of Acupuncture Research
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• v.27 no.4
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• pp.147-178
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• 2010

Objectives : This study was to propose the improved instruction for authors and research ethic regulations by the comparative analysis of those of the domestic journals, for the purpose of enhancing the citation rate of Journal of Korean Acupuncture and Moxibustion Society. Methods : Narrative review method was used for comparatively analyzing instruction for authors of 34 domestic journals, especially focused on how to write a reference. Thereafter, in order to elucidate the drawbacks of current instruction for authors and research ethic regulations of the acupuncture and moxibustion society, the well prepared instructions and research ethic regulations was selected from them, which were compared with the present instructions for authors and research ethic regulations of the acupuncture and moxibustion society. Results : As a result of the comparative analysis of instruction for authors in the 34 domestic journals, style for references was based largely on that of National Library of Medicine and vancouver at the same time. The number of reference was limited according to types of writings. for example, the original article and case report was frequently limited to 40 and 20 references respectively. Authors were mostly listed up to six. If there are more, the first three or six authors were listed with 'et al'. it was generally recommended that using abstracts as references should be avoided and References to papers accepted but not yet published should be designated as 'in press' or 'forthcoming', and that the names of journals should be set in italics and abbreviated according to the List of Journals Indexed for Medline (formerly Index Medicus) published by the National Library of Medicine or koreanmed or WHO-IST, etc. In addition, citation of electrical literature, English writing of reference and obligational citation of more than two articles in the journals were encouraged. In consequence of comparison between well prepared instructions and research ethic regulations of the selected journals and those of current instructions for authors and research ethic regulations of the acupuncture and moxibustion society, the followings were needed to be added or revised. 1. Requirements for case reports were not mentioned. 2. Reporting Guidelines for Specific Study Designs were not included. 3. Previous Orthography of herbal prescription should be revised. 4. Orthography of authors and guidelines for writing article constituents such as title, abstract, introduction, method, statistics, results, discussions were not presented. 5. How to write a reference was so simplified. 6. Definition of Research Ethical Misconduct was omitted and establishment, management and members of committee for research ehtics were not mentioned, 7. Information, reception and investigative procedures of Research Ethical Misconduct was not specified. Conclusions : For the development of Journal of Korean Acupuncture and Moxibustion Society, apporopriate revision of the instruction for author and research ethic regulations should be made based upon the above findings. English writing of reference were believed to be one of the alternatives enhancing citation rate.

• Journal of KIISE
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• v.42 no.9
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• pp.1071-1077
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• 2015

In this paper, we adopt PCM (phase-change memory) as a virtual memory swap device and present a new page replacement policy that considers the characteristics of PCM. Specifically, we aim to reduce the write traffic to PCM by considering the dirtiness of pages when making a replacement decision. The proposed policy tracks the dirtiness of a page at the granularity of a sub-page and replaces the least dirty page among the pages not recently used. Experimental results show that the proposed policy reduces the amount of data written to PCM by 22.9% on average and up to 73.7% compared to CLOCK. It also extends the lifespan of PCM by 49.0% and reduces the energy consumption of PCM by 3.0% on average.

• Journal of Korea Multimedia Society
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• v.10 no.5
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• pp.604-611
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• 2007

Java Card has gained genera1 acceptance with standard for smart card and (U)SIM technology, and it is in distinction from native card by its post-issuance of an application and independence from hardware platforms. However, a main weak point of Java Card is its low execution speed caused by the hardware limitation and Java programming language itself. In this paper, we propose a new Java Card Installer to improve the download speed during the post-issuance of an application by resolving symbolic references to physical references in HAM. Our Resolution_In_RAM is based on the improved new RAM writing is 100,000 times faster than EEPROM writing and PageBuffer that is operated as block mode, rather than cell mode is used to write to EEPROM. Consequently, the total number of EEPROM writing are reduced 37%, and the times of downloading are reduced over 30% by using the Resolution_In_RAM-based Java Card Installer.

• Journal of Information Management
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• v.19 no.2
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• pp.55-90
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• 1988

The abbreviation of titles of periodicals was studied as a part of standardizations in bibliographic information inscription which were needed for dissemination of scientific and technological informations. The fundamental principles and the base draft were framed for the range of application, the titles of periodicals which should be abbreviated and the conditions and methods of abbreviation. The rules given in this base draft for abbreviation of titles are applicable to write out the secondary source and to describe the references.