• Journal of KIISE:Computer Systems and Theory
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• v.32 no.11_12
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• pp.663-674
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• 2005

We propose a system aimed at achieving high energy-delay efficiency by using adaptive victim caches. Particularly, we investigate methods to improve the hit rates in the first level of memory hierarchy, which reduces the number of accesses to mort power consuming memory structures such as L2 cache. Victim cache is a memory element for reducing conflict misses in a direct-mapped L1 cache. We present two techniques to fill the victim cache with the blocks that have higher probability to be re-reqeusted by processor. Hit-based victim cache ks tilled with the blocks which were referenced frequently by processor. Replacement-based victim cache is filled with the blocks which were evicted from the sets where block replacements had happened frequently According to our simulations, replacement-based victim cache scheme outperforms the conventional victim cache scheme about $2\%$ on average and refutes the power consumption by up to $8\%$.

• The KIPS Transactions:PartA
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• v.12A no.3 s.93
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• pp.215-222
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• 2005

The efficient utilization of cache memories is a key factor in achieving high performance for computing large signal transforms. Nonunit stride access in computation of large DFTs causes cache conflict misses, thereby resulting in poor cache performance. It leads to a severe degradation in overall performance. In this paper, we propose a dynamic data layout approach considering the memory hierarchy system. In our approach, data reorganization is performed between computation stages to reduce the number of cache misses. Also, we develop an efficient search algorithm to determine the optimal tree with the minimum execution time among possible factorization trees considering the size of DFTs and the data access stride. Our approach is applied to compute the fast Fourier Transform (FFT). Experiments were performed on Pentium 4, $Athlon^{TM}$ 64, Alpha 21264, UtraSPARC III. Experiment results show that our FFT achieve performance improvement of up to 3.37 times better than the previous FFT packages.

• Journal of Digital Contents Society
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• v.18 no.2
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• pp.303-309
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• 2017

The purpose of this study is to determine the cause and result of the smartphone use in the classroom, focusing on students from Child Care departments in colleges. The targets of this study were 10 college students from child care departments and data was collected through in-depth interviews. The results of the study are as follows. [Cause of use] was divided into and . [Negative result] has been identified by and . [positive result] has been identified by < Learning Support >, < Memory Support >. The study is believed to contribute to identifying the problems of smartphone use of college students in the future and contributing to the provision of basic materials for the use of favorable purposes.

• The Korean Journal of Air & Space Law and Policy
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• v.18
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• pp.105-134
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• 2003

This paper describes generic cognitive aspects of the air traffic controller's performance and perceptive activities unveiled through the past literature study. which underlines mental modelling and mental picture presented in the middle of complicated situational awareness and decision making process when air traffic controller comes to determine the distance between aircraft under control to maintain air traffic in a safe, orderly and expeditious way. It also describes human limit in terms of human memory in conjunction with relative workloads and environmental factor. In conclusion, It suggest that ATC authority will take into account the qualitatiive adjustment of training requirement necessary for ATC facility rating and refresher training to allow them more preparedness for better situational awareness and optimal decision making. In this paper controller's behavioral activators affecting their job performance are addressed in perspective of aviation safety.

• Architectural research
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• v.25 no.2
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• pp.29-40
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• 2023

The purpose of this study is to analyze the conflicts caused by the spatial expansion in two types of urban heritage in Seoul. To explain the national and professional orientation found in each spatial transformation, the study brought the concept of 'historic state' and 'epitome,' thereby examining the operating system of the conflicts. Field observations and stakeholder interviews were performed based on literature and historical research. The study results are as follows. ①In the case of Gwanghwamun and Donuimun, the spatial expansion is to find the historic state of the sites. Gwanghwamun with high national status and substance, conflicts show a pattern that spreads to memory conflicts. Donuimun is relatively unknown and has no substance so that a flexible method of digital restoration was applied. ② In the case of Ikseon-dong and Bukchon hanok, they show heterogeneous spatial expansion. The conflicts in relation to this is caused by the epitome of hanok. In Ikseon-dong, illegal installation of structures(non-epitome) is prevalent, while in Bukchon, there was a process of transferring the new basement(non-epitome) as part of the hanok. ③Conflicts in Gwanghwamun can be coordinated by referring to the digital restoration of Donuimun, and conflicts in Ikseon-dong can be resolved by taking Bukchon as a precedent.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.6
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• pp.98-114
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• 2017

This study analyzed the commemorative landscapes of eight Holocaust concentration camp memorials(HCCM) of Germany and Poland from a landscape architecture point of view including historical landscape, places and remains, and monuments. A site survey was conducted at Dahau concentration camp memorial(CCM) and Bergen-Belsen CCM of Germany in September of 2015 and the Auschwitz-Birkenau extermination camp memorial(ECM), Majdanek ECM, Belzec ECM, Sobibor ECM, Treblinka ECM, Chelmno ECM of Poland in April of 2016. The results are as follows. First, the landscape of the concentration camp at Dahau CCM, Auschwitz ECM, and Majdanek ECM liberated by the Allied Forces was well conserved with the maintenance of camp facilities and the spatial structure of camps while monuments and memorials seized by sociopolitical argument were built with restriction. But Belzec ECM, Sobibor ECM, Treblinka ECM, and Chelmno ECM devastated and planted artificially to forest were overwhelmingly surrounded with natural landscape, and also, excavated relics and remains were preserved and the monuments were built at the place of memory. Second, gas chambers, crematoriums, guard posts, electric wire fences, railroads and ramps, barracks, and drainage ditches were considered to be typical facilities present in the camp structure and the gas chambers, crematoriums, human ashes, and mass graves demonstrated the horrible history of these camps and the railroad and ramp where Jewish prisoners arrived also had the strong sense of place. These remains were regarded as symbolic elements to create a memory of the tragedy and place. Third, commemoration of victims was applied as the basic concept and recalling the memory of the Holocaust was also considered very important content. Religious reconciliation and peace was represented at Dahau CCM and the Jewish identity was strongly expressed at Treblinka ECM and Belzec ECM representing the Jewish community and Judaism. Fourth, the monuments with semi-abstract styles and abstract sculptures represented the Holocaust symbolically and narratively and came into the conflict caused by the abstractness to the memorial landscape at Auschwitz-Birkenau ECM and Bergen-Belsen CCM. Fifth, remains for recalling the memory of tragedy and place and symbolic monuments to stand for public memory were juxtaposed at the same place and preserving on the authenticity of camp site had been conflicted with monumentalizing intentionally. Further study will required a concrete investigation of the monuments in the HCCM and an attempt to comparatively study the commemoration characteristics of memorials in Korea.

• The KIPS Transactions:PartA
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• v.16A no.2
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• pp.69-78
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• 2009

One of the most effective way to improve cache performance is to exploit both temporal and spatial locality given by any program executive characteristics. In this paper we present a high performance and low power cache structure with a bank selection mechanism that enhances exploitation of spatial and temporal locality. The proposed cache system consists of two parts, i.e., a main direct-mapped cache with a small block size and a fully associative buffer with a large block size as a multiple of the small block size. Especially, the main direct-mapped cache is constructed as two banks for low power consumption and stores a small block which is selected from fully associative buffer by the proposed bank selection algorithm. By using the bank selection algorithm and three state bits, We selectively extend the lifetime of those small blocks with high temporal locality by storing them in the main direct-mapped caches. This approach effectively reduces conflict misses and cache pollution at the same time. According to the simulation results, the average miss ratio, compared with the Victim and STAS caches with the same size, is improved by about 23% and 32% for Mibench applications respectively. The average memory access time is reduced by about 14% and 18% compared with the he victim and STAS caches respectively. It is also shown that energy consumption of the proposed cache is around 10% lower than other cache systems that we examine.

• Journal of KIISE:Databases
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• v.36 no.2
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• pp.150-167
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• 2009

XML has become the new standard for storing, exchanging, and publishing of data over both the internet and the ubiquitous data stream environment. As demand for efficiency in handling XML document grows, labeling scheme has become an important topic in data storage. Recently proposed labeling schemes reflect the dynamic XML environment, which itself provides motivation for the discovery of an efficient labeling scheme. However, previous proposed labeling schemes have several problems: 1) An insertion of a new node into the XML document triggers re-labeling of pre-existing nodes. 2) They need larger memory space to store total label. etc. In this paper, we introduce a new labeling scheme called a Circle Labeling Scheme. In CLS, XML documents are represented in a circular form, and efficient storage of labels is supported by the use of concepts Rotation Number and Parent Circle/Child Circle. The concept of Radius is applied to support inclusion of new nodes at arbitrary positions in the tree. This eliminates the need for re-labeling existing nodes and the need to increase label length, and mitigates conflict with existing labels. A detailed experimental study demonstrates efficiency of CLS.

• The Korean Journal of Archival Studies
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• no.44
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• pp.217-241
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• 2015

The sinking of the Sewol ferry has not only induced an intense conflict in Korean society but also been developed into a sociopolitical issue. This paper divides this accident into five stages and examines the records produced at each stage. The Sewolho Citizen Archive Network and the Ansan Citizen Record Committee began the archiving of Sewol and created the 416 Archives. The records of Sewol are social and political records that hold envidencial and historical value. They can be used to rebuild and recover the wounded community as well as to investigate the truth behind the case. Accident archiving collects materials different to the ones which public archiving does, allowing people to view the incident from a different standpoint. It is also characterized as an archiving of the current issue, social movement and regional community. Accident archiving is a method which ensures credibility and impartiality in memory. In light of Sewol archives, accident archiving can contribute to form mature democracy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.2
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• pp.542-558
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• 2023

A digital focus index (DFI) is a value used to determine image focus in scientific apparatus and smart devices. Automatic focus (AF) is an iterative and time-consuming procedure; however, its processing time can be reduced using a general processing unit (GPU) and a multi-core processor (MCP). In this study, parallel architectures of a minimax search algorithm (MSA) are applied to two DFIs: range algorithm (RA) and image contrast (CT). The DFIs are based on a histogram; however, the parallel computation of the histogram is conventionally inefficient because of the bank conflict in shared memory. The parallel architectures of RA and CT are constructed using parallel reduction for MSA, which is performed through parallel relative rating of the image pixel pairs and halved the rating in every step. The array size is then decreased to one, and the minimax is determined at the final reduction. Kernels for the architectures are constructed using open source software to make it relatively platform independent. The kernels are tested in a hexa-core PC and an embedded device using Lenna images of various sizes based on the resolutions of industrial cameras. The performance of the kernels for the DFIs was investigated in terms of processing speed and computational acceleration; the maximum acceleration was 32.6× in the best case and the MCP exhibited a higher performance.