• IEMEK Journal of Embedded Systems and Applications
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• v.7 no.3
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• pp.129-134
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• 2012

The objective of cache is to reduce I/O access of physical storage device so that user accesses their data faster. Traditionally, the most important metric to measure the performance of cache is hitratio. Thus, when the cache maintains hitratio high, it is regarded as a good cache replacement policy. However, the cache miss latency is different when the storages are heterogeneous. Though the cache hitratio is high, if the cache often misses with low performance disk, then the user experiences low performance. To address this problem we proposed eviction cost estimation based cache management. In our result, the eviction cost estimation based cache management has 10~30% throughput improvement compared with LRU cache management.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.740-743
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• 2015

The increasing complexity of integrated circuits and IP-based hardware designs have created the risk of hardware Trojans. This paper introduces a new type of threat, the coherence-exploiting hardware Trojan. This Trojan can be maliciously implanted in master components in a system, and continuously injects memory read transactions on to bus or main interconnect. The injected traffic forces the eviction of cache lines, taking advantage of cache coherence protocols. This type of Trojans insidiously slows down the system performance, incurring Denial-of-Service (DoS) attack. We used Xilinx Zynq-7000 device to implement and evaluate the coherence-exploiting Trojan. The malicious traffic was injected through the AXI ACP interface in Zynq-7000. Then, we collected the L2 cache eviction statistics with performance counters. The experiment results reveal the severe threats of the Trojan to the system performance.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06a
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• pp.349-351
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• 2012

낸드 플래시 메모리에서 가비지 콜렉션은 블록의 유효한 데이터들을 새로운 블록으로 옮기고 오래된 블록을 지우는 과정이다. 가비지 콜렉션에 의해 옮겨지는 페이지들은 작업의 양과 형태에 따라 오랫동안 유효한 페이지로 존재하기도 하고 그렇지 않은 경우도 있다. 본 논문에서는 반도체 디스크(Solid State Drive, 이하 SSD)에서 가비지 콜렉션이 비효율적으로 일어나는 경우를 정의하고 비효율적 가비지 콜렉션 과정으로 인한 비용을 줄이는 캐시 방출 기법을 소개한다. 이 기법을 시뮬레이션 해본 결과 작업 형태가 순차적일 때 LRU 캐시 알고리즘과 같이 사용되면 가비지 콜렉션에 의해 옮겨지는 페이지를 12%, 전체 쓰기 연산 횟수를 9%까지 줄일 수 있었고 블록 단위 LRU 알고리즘과 사용했을 때도 보다 좋은 성능을 보였다.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.1
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• pp.7-14
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• 2017

Due to the recent advances in Phage-Change Memory (PCM) technologies, a new memory hierarchy of computer systems with PCM is expected to appear. In this paper, we present a new page replacement policy that adopts PCM as a high speed swap device. As PCM has limited write endurance, our goal is to minimize the amount of data written to PCM. To do so, we defer the eviction of dirty pages in proportion to their dirtiness. However, excessive preservation of dirty pages in memory may deteriorate the page fault rate, especially when the memory capacity is not enough to accommodate full working-set pages. Thus, our policy monitors the current working-set size of the system, and controls the deferring level of dirty pages not to degrade the system performances. Simulation experiments show that the proposed policy reduces the write traffic to PCM by 160% without performance degradations.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.3
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• pp.349-356
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• 2003

The aim of this paper is to investigate the friction characteristics of piston assembly. The friction of piston assembly is composed of ring pack and skirt friction. In this paper, the theoretical models of piston ring pack and piston skirt were presented. The mixed lubrication theory was considered to calculate friction force of piston ring and skirt. from the results, most of friction in piston assembly occurred at the piston ring park. The piston assembly usually showed hydrodynamic lubrication characteristics. but the top and bottom dead centers showed mixed lubrication characteristics. The piston skirt was much affected by radial clearance and load, but ring was significantly influenced by ring tension.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04b
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• pp.55-57
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• 2001

캐쉬 대체 알고리즘은 캐쉬 적재공간의 한계성을 극복하는 방법 중에 하나이다. 기존의 많은 대체 알고리즘의 문제점인 대체 기준치의 부정확성 및 불충분성을 해결하기 위해 인기도를 제안하였다. 인기도는 인기 검색어의 순위를 정규화 한 값으로, 대량의 자료를 바탕으로 얻어진 통계치이다. 인기도 산출의 기반이 되는 인기 검색어는 시간적 흐름에 민감하고, 사회 전반적인 경향을 반영하며, 많은 중복을 가지고 있다. 인기도는 각 검색 엔진별로 단일 인기도와 누적 인기도를 산출한 후에, 이를 모두 병합하여 산출된다. 이것을 병합 인기도라고 하며, 이는 임의의 검색어에 0에서 1사이의 소수값으로 부여된다. 인기도는 메타 검색 엔진에서 캐쉬 대체를 수행할 때 적용될 수 있으며, 다수의 자료 입력 경향에 관한 정보가 존재하는 문제 영역에 사용될 수 있다.

• KSTLE International Journal
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• v.1 no.1
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• pp.1-7
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• 2000

Eviction characteristics of two typical friction materials (non-asbestos organic and low-steel friction materials) for an automotive brake system were investigated using an inertial brake dynamometer. In particular, the effect of sliding speed on friction coefficient was carefully investigated employing various test modes. The two friction materials were developed for commercial applications and were different mainly in the type and the amount of metallic ingredients in the friction material. The dynamometer test showed that the low-steel friction material was sensitive to the sliding speed exhibiting a negative $\mu$-v relation. On the other hand, the non-asbestos organic friction material was less sensitive to the sliding speed. The low steel friction materials with a negative $\mu$-v relation also induced larger vibration amplitude during brake applications.

• Journal of the Korea Society of Computer and Information
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• v.23 no.4
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• pp.1-8
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• 2018

In this paper, we propose an adaptive partition cache replacement policy and evaluate the performance of our scheme using various monitoring ratios to help lifetime extension of non-volatile main memory systems without performance degradation. The proposal combines conventional LRU (Least Recently Used) replacement policy and Early Eviction Zone (E2Z), which considers a dirty bit as well as LRU bits to select a candidate block. In particular, this paper shows the performance of non-volatile memory using various monitoring ratios and determines optimized monitoring ratio and partition size of E2Z for reducing the number of writebacks using cache hit counter logic and hit predictor. In the experiment evaluation, we showed that 1:128 combination provided the best results of writebacks and runtime, in terms of performance and complexity trade-off relation, and our proposal yielded up to 42% reduction of writebacks, compared with others.

• The Korean Society of Law and Medicine
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• v.24 no.2
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• pp.79-117
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• 2023

Among the healthcare-related judgments handed down in 2002, there was a significant ruling on the timing of the duty of explanation, stating that, in order to ensure the exercise of the patient's right to self-determination, the patient must be given time to consider and decide on the risks and side effects of a medical procedure in specific circumstances. In addition, in a case where an insurance company claimed unjust enrichment against a medical institution on behalf of its insureds, the court provided a clear standard by distinguishing between active and passive requirements regarding the need to preserve the right of subrogation of creditors. In the area of medical administration, there was a ruling that clarified that a medical institution's business suspension under the National Health Insurance Act is directed against the medical institution, a ruling that broadly recognized causation in a case of compensation for side effects of corona vaccination, and a ruling on the scope of a medical practitioner's license, such as the use of ultrasound devices by an oriental medicine practitioner. In a case involving a patient's claim for eviction from a medical institution, the court reviewed a ruling on just cause for termination of a hospitalization contract in relation to Article 15(1) of the Medical law.

• Journal of architectural history
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• v.22 no.5
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• pp.37-46
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• 2013

This paper aims to examine the constructional background and process of the Japanese military installations of Jisim-do, especially based on the military secret documents. Furthermore, it aims to analyze the characteristics of the remains. First, the study looked into the procedure of forcible occupation by Japan, involving the background of the designation and forcible accommodation of military reservations, and forced eviction by the purchase of land. Second, the study identified the background of construction, purpose, and construction period of each battery built throughout the 'Fort maintenance period' according to changes in international situations. Third, it is the 'Chukseongbu' that supervised the construction of fortresses. Fourth, the study considered a series of arrangement processes in which Jisim-do became a fortresses through "Yukgunsungdae-ilgi", a military operations report for the Japanese army. Through this, it discovered a clear construction process, construction details, and the supply for Jisim-do. The study was also able to reveal the meticulousness in constructing firm facilities more promptly from the 'design tactics'.