• Journal of the Semiconductor & Display Technology
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• v.22 no.3
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• pp.106-111
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• 2023

The importance of load-to-use latency has been highlighted as state-of-the-art computing cores adopt deep pipelines and high clock frequencies. The cascaded cache was recently proposed to reduce the access cycle of the L1 cache by utilizing differences in latencies among banks of the cache structure. However, this study assumes the cache is comprised of SRAM, making it unsuitable for direct application to non-volatile memory-based systems. This paper proposes a novel mechanism and structure for lowering dynamic energy consumption. It inserts monitoring logic to keep track of swap operations and write counts. If the ratio of swap operations to total write counts surpasses a set threshold, the cache controller skips the swap of cache blocks, which leads to reducing write operations. To validate this approach, experiments are conducted on the non-volatile memory-based cascaded cache. The results show a reduction in write operations by an average of 16.7% with a negligible increase in latencies.

• Journal of KIISE
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• v.43 no.8
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• pp.841-847
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• 2016

As network technology advances, a larger number of devices are connected through the Internet. Recently, cloud storage services are gaining popularity, as they are convenient to access anytime and anywhere. Among cloud storage services, object storage is the representative one due to their characteristics of low cost, high availability, and high durability. One limitation of object storage services is that they can access data on the cloud only through the HTTP-based RESTful APIs. In our work, we resolve this limitation with the in-memory file system which provides a POSIX interface to the file system users and communicates with cloud object storages with RESTful APIs. In particular, our flush mechanism is compatible with existing file systems, as it is based on the swap mechanism of the Linux kernel. Our in-memory file system backed by cloud storage reduces the performance overheads and shows a better performance than S3QL by 57% in write operations. It also shows a comparable performance to tmpfs in read operations.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10a
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• pp.89-92
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• 2001

최근 인터넷의 발전과 더불어 전자상거래의 발전으로 워크플로우 관리 시스템 역시 변화의 요구가 증가되고 있다. 이러한 요구는 하나의 워크플로우 관리시스템에서만 운영되는 서비스 뿐만 아니라 서로 다른 환경의 워크플로우 관리시스템의 사용까지도 요구하고 있는 변화와 맞물리는 것이다. 이에 본 논문은 워크플로우 관리 시스템 중 Workflow Management Coalition 의 명세서의 WfMC 참조 모델 중 인터페이스 4 에 해당하는 워크플로우 엔진과 상호 운용성을 위한 서로 다른 워크플로우 서비스를 하는 엔진의 상호작용에 대해 기술하였다. 이렇게 서로 다른 워크플로우 엔진과의 상호 운용성을 위해 도입된 SWAP ( Simple Workflow Access Protocol )과 현재 새롭게 대두되고 있는 Wf-XML 을 통해 시스템간의 상호운용성에 대해 연구하고 또한 이러한 기술을 적용 함으로써 안정되고 확장된 워크플로우 관리 시스템간의 출현을 기대할 수 있다.

• Journal of the Korea Computer Industry Society
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• v.3 no.3
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• pp.391-406
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• 2002

In order to realize a practical VOD system, it is necessary for a high-capacity and cost-effective hierarchical VOD server based on tertiary storages such as DVD jukebox. In such a system, it is possible to transfer multiple streams to users by alternatively swapping DVDs using the fixed number of drives. But it takes a long time for loading DVD to a drive. In this paper, we propose a primitive pipelined loading mechanism for hiding the loading time to swap DVDs in a hierarchical VOD server based on DVD jukebox. We also propose a enhanced pipelined loading mechanism for increasing the maximum admittable streams with the fixed number of drives. The enhanced mechanism caches the initial segment of each stream on a disk storage allowing faster data transfer. The performance analysis shows that the proposed mechanisms can admit the maximum allowed stream capacity under the fixed number of disk drives.

• The Journal of Asian Finance, Economics and Business
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• v.5 no.2
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• pp.5-14
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• 2018

This study is motivated based on concern from some renowned scholars and central bankers whom have raised the issue of the sustainability of the International Monetary System (IMS). Using the panel data set of four major international currencies, USD, JPY, EUR and GBP from 1973 to 2013 with Pooled Mean Group (PMG) estimator, to re-examine whether Triffin dilemma still exists through investigating the relationship between the reserve share, current account balance and real effective exchange rate. The evidence from the result indicates that Triffin dilemma exists only in the long run, and shows that in the long-run, current account balance is proportionate to the increased real effective exchange rate while varies inversely with the reserve shares. However, the estimation for the short-run is not significant to prove the existence of Triffin dilemma. In addition, we investigated the non-dollar panel sample and found that the international monetary system still suffers from Triffin dilemma even without the dollar. To overcome Triffin dilemma, immediate step such as having currency swap mechanism is recommended. In medium term, a multi-polar Monetary System is suggested, and in the longer time, a supranational currency will be used to replace all the currencies in the world.

• Journal of Communications and Networks
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• v.13 no.1
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• pp.17-25
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• 2011

A convergecast is a popular routing scheme in wireless sensor networks (WSNs) in which every sensor node periodically forwards measured data along configured routing paths to a base station (BS). Prolonging lifetimes in energy-limited WSNs is an important issue because the lifetime of a WSN influences on its quality and price. Low-energy adaptive clustering hierarchy (LEACH) was the first attempt at solving this lifetime problem in convergecast WSNs, and it was followed by other solutions including power efficient gathering in sensor information systems (PEGASIS) and power efficient data gathering and aggregation protocol (PEDAP). Our solution-chain routing with even energy consumption (CREEC)-solves this problem by achieving longer average lifetimes using two strategies: i) Maximizing the fairness of energy distribution at every sensor node and ii) running a feedback mechanism that utilizes a preliminary simulation of energy consumption to save energy for depleted Sensor nodes. Simulation results confirm that CREEC outperforms all previous solutions such as LEACH, PEGASIS, PEDAP, and PEDAP-power aware (PA) with respect to the first node death and the average lifetime. CREEC performs very well at all WSN sizes, BS distances and battery capacities with an increased convergecast delay.

• The Journal of the Korea Contents Association
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• v.7 no.8
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• pp.59-65
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• 2007

Overlay Multicast is an effective method for efficient utilization of system resources and network bandwidth without a need for hardware customization. Multicast tree reconstruction is required when a non-leaf node leaves or fails. However frequent multicast tree reconstruction introduces serious degradation in performance. In this paper, we propose a tree performance optimization algorithm to solve this defect by using information(RTCP-probing) that becomes a periodic feedback to a source node from each child node. The proposed model is a mechanism performed when a parent node seems to cause deterioration in the tree performance. We have improved the performance of the whole service tree using the mechanism and hence composing an optimization tree. The simulation results show that our proposal stands to be an effective method that can be applied to not only the proposed model but also to existing techniques.

• Molecular & Cellular Toxicology
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• v.5 no.1
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• pp.67-74
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• 2009

Exposures to environmental chemicals that mimic endogenous hormones are proposed for a number of adverse health effects, including infertility, abnormal prenatal and childhood development and above all cancers. In addition, recently miRNA (micro RNA) has been recognized to play an important role in various diseases and in cellular and molecular responses to toxicants. In this study, endocrine disrupting environmental toxicant, nonylphenol (NP) was treated to MCF-7 (Human breast cancer cell) and HepG2 (Human hepatocellular liver carcinoma) cell line at 3 hrs and 48 hrs time point and miRNA analysis using $mirVana^{TM}$ miRNA bioarray was performed and compared with total mRNA microarray data for the same cell line and treatment. Robust data quality was achieved through the use of dye-swap. Analysis of microarray data identifies a total of 20 and 11 miRNA expressions at 3 hrs and 48 hrs exposure to NP in MCF-7 cell line and a total of 14 and 47 miRNA expression at 3 hrs and 48 hrs exposure respectively to NP in HepG2 cell line. Expression profiling of the selected miRNA (let-7c, miR-16, miR-195, miR-200b, miR200c, miR-205, and miR-589) reveals changes in the expression of target genes related to metabolism, immune response, apoptosis, and cell differentiation. The present study can be informative and helpful to understand the role of miRNA in molecular mechanism of chemical toxicity and their influence on hormone dependent disease. Also this study may prove to be a valuable tool for screening potential estrogen mimicking pollutants in the environment.

• KDI Journal of Economic Policy
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• v.13 no.1
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• pp.35-63
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• 1991

Currently, Korea's banking industry holds a sizable amount of non-performing loans which stem from the government-led bailout of many troubled firms in the 1980s. Although this burden was somewhat relieved with the aid of banks' recapitalization in the booming securities market between 1986-88, the insolvent credits still resulted in low profitability in the banking sector and have been detrimental to the progress of financial liberalization and internationalization. This paper surveys the corporate bailout experiences of major advanced countries and Korea in the past and derives a rationale for readjustment measures against non-performing loans, in which rescue plans depend on the nature of the financial system. Considering the features of Korea's financial system and the banking sector's recent performance, it discusses possible means of liquidation in keeping with the rationale. The conflict of interests among parties involved in non-performing loans is widely known as one of the major constraints in writing off the loans. Specifically, in the case of Korea, the government's excessive intervention in allocating credits has preempted the legitimate role of the banking sector, which now only passively manages its past loans, and has implicitly confused private with public risk. This paper argues that to minimize the incidence of insolvent loan readjustment, the government's role should be reduced and that the correspondent banks should be more active in the liquidation process, through the market mechanism, reflecting their access to detailed information on the troubled firms. One solution is that banks, after classifying the insolvent loans by the lateness or possibility of repayment, would swap the relatively sound loans for preferred stock and gradually write off the bad ones by expanding the banks' retained earnings and revaluing the banks' assets. Specifically, the debt-equity swap can benefit both creditors and debtors in the sense that it raises the liquidity and profitability of bank assets and strengthens the debtor's financial structure by easing the debt service burden. Such a creditor-led or market-led solution improves the financial strength and autonomy of the banking sector, thereby fostering more efficient resource allocation and risk sharing.