• Title/Summary/Keyword: k-코어

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Analytical Study on Equivalent Shear Modulus according to Shape of Egg-box Core (에그-박스 코어 형상 변화에 따른 등가 전단 탄성계수 수치 해석 연구)

  • Lee, SangYoun;Yun, Su-Jin;Park, DongChang;Hwang, Kiyoung
    • Journal of the Korean Society of Propulsion Engineers
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    • v.18 no.2
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    • pp.73-79
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    • 2014
  • The sandwich shell with Egg-box core has been used for the combustion chamber case of air breathing propulsion system. The alteration on pitch length and thickness of Egg-box core was required to be lighter and save manufacturing time and cost of combustion chamber case. In this paper, the finite element analysis method which simulated bending test was used to predict the equivalent shear modulus which affect structural stability of sandwich shell in short time. The result of FE calculation on sandwich panel with homogeneous material, H130-foam core, showed a good agreement with the values available in the reference. The equivalent shear modulus of Egg-box core according to the variation of pitch length and thickness can be obtained.

Core-aware Cache Replacement Policy for Reconfigurable Last Level Cache (재구성 가능한 라스트 레벨 캐쉬 구조를 위한 코어 인지 캐쉬 교체 기법)

  • Son, Dong-Oh;Choi, Hong-Jun;Kim, Jong-Myon;Kim, Cheol-Hong
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.11
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    • pp.1-12
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    • 2013
  • In multi-core processors, Last Level Cache(LLC) can reduce the speed gap between the memory and the core. For this reason, LLC has big impact on the performance of processors. LLC is composed of shared cache and private cache. In computer architecture community, most researchers have mainly focused on the management techniques for shared cache, while management techniques for private cache have not been widely researched. In conventional private LLC, memory is statically assigned to each core, resulting in serious performance degradation when the workloads are not fairly distributed. To overcome this problem, this paper proposes the replacement policy for managing private cache of LLC efficiently. As proposed core-aware cache replacement policy can reconfigure LLC dynamically, hit rate of LLC is increases drastically. Moreover, proposed policy uses 2-bit saturating counters to improve the performance. According to our simulation results, the proposed method can improve hit rates by 9.23% and reduce the access time by 12.85% compared to the conventional method.

An Optimal Structure of Phase Shift Full Bridge Converter for High-capacity On-board Battery Charger of Electric Vehicle (EV용 대용량 탑재형 배터리 충전기에 적합한 Phase Shift Full Bridge Converter의 최적 구조)

  • Kim, Min-Kook;Kim, Yun-Sung;Cho, Nam-Jin;Lee, Byoung-Kuk
    • Proceedings of the KIPE Conference
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    • 2012.07a
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    • pp.35-36
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    • 2012
  • 본 논문은 EV용 탑재형 배터리 충전기(OBC)와 같은 중 대용량 충전시스템에 적용한 Phase Shift Full Bridge Converter (PSFB) 토폴로지를 사용하는 경우, 트랜스포머의 구조에 따른 특성을 분석한다. 일반적으로 PSFB는 다른 토폴로지에 비해 코어 사용 효율이 높기 때문에 상대적으로 소형 경량화 설계가 용이하다. 그러나 수 kW급의 시스템 응용에서는 기존 코어 형상이나 Ap-limit과 제약이 따른다. 또한 특화된 코어의 경우 높은 가격으로 설계 경쟁력이 낮아진다. 따라서 본 논문에서는 이러한 대용량 PSFB의 응용 시스템에 적합한 코어 설계를 위해 다양한 트랜스포머의 구조를 선정하여 그 특성을 비교분석한다.

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Spinlock for Locking Individual Objects on Multicore (멀티코어에서 개별 객체 잠금을 위한 스핀락)

  • Kim, Sang Cheol;Ma, Yu-Seung;Woo, Duk-Kyun;Mah, Pyeongsoo;Kim, Seon-Tae
    • Annual Conference of KIPS
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    • 2015.10a
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    • pp.202-203
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    • 2015
  • 멀티코어 시스템에서는 서로 다른 코어들이 공통 데이터를 동시에 접근할 때 데이터의 일관성을 유지하기 위해서 스핀락 기법을 사용한다. 전통적인 스핀락을 이용한 잠금 기법에서는 잠금 변수가 실행 도중 삭제되지 않으므로 문제가 되지 않는다. 그러나 병렬성을 최대화하기 위해서는 개별 객체 잠금을 하여야 하고 이를 위해서는 객체내에 잠금 변수를 유지하여야 한다. 이 경우 객체는 도중에 언제든지 삭제가 가능하기 때문에 잠금을 하는 도중에는 잠금 변수가 절대 삭제되지 않도록 하여야 한다. 본 논문은 멀티코어상에서 발생하는 이 같은 문제를 해결하기 위해 잠금 변수를 객체 내에 유지할 때의 개별적인 객체 잠금을 위한 스핀락 구현 방법을 제시한다.

Application Core Mapping to Minimize the Network Latency on Regular NoC Architectures (규칙적인 NoC 구조에서의 네트워크 지연 시간 최소화를 위한 어플리케이션 코어 매핑 방법 연구)

  • Ahn, Jin-Ho;Kim, Hong-Sik;Kim, Hyun-Jin;Park, Young-Ho;Kang, Sung-Ho
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.4
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    • pp.117-123
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    • 2008
  • In this paper, we propose a novel ant colony optimization(ACO)-based application core ma ins method for implementing network-on-chip(NoC)-based systems-on-chip(SoCs). The proposed method efficiently put application cores to a mesh-type NoC satisfying a given design objective, the network latency. Experimental results using a functional circuit including 12 cores show that the proposed algorithm can produce near optimal mapping results within a second.

Precision Grinding System for Micro Core-pin (마이크로 코어 핀 정밀 연삭 시스템)

  • Yang, Ji-Kyung;Lee, In-Cheol;Kang, Dong-Seong;Han, Bong-Seok;Han, Yu-Jin;Lee, Jung-Woo;Song, Ki-Hyeok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.4
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    • pp.50-57
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    • 2017
  • In the injection molding process, a core that builds a space for a product is installed at the internal place in the mold and fabricated as the frame of the mold. In this make up, the fabricating partial form of the mold at a pin is a core pin. The core pin is finer because an injection mold produces miniaturization and integration. On the other hand, when the core is manufactured using the existing centerless grinder, it generates vibrations because of the lack of a fixed zig for a micro size workpiece. For this reason, an existing centerless grinder without a micron size fixed zig, makes a defective product due to vibration and deformation. In this study, a compact grinding system that can be installed using an existing centerless grinder was fabricated to make a micro size core pin. Using the compact grinding system, grinding experiment for core pin was carried out. The performance of the system was confirmed by measuring the surface roughness, roundness, and cylindricity.

Microleakage of endodontically treated teeth restored with three different esthetic post and cores (심미적 포스트 코어의 종류에 따른 미세누출에 관한 연구)

  • Park, Ji-Geun;Park, Ji-Man;Park, Eun-Jin
    • The Journal of Korean Academy of Prosthodontics
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    • v.47 no.1
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    • pp.53-60
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    • 2009
  • Statement of problem: At present, as the esthetic demands are on the increase, there are many ongoing studies for tooth-colored post and cores. Most of them are about fiber post and prefabricated zirconia post, but few about one-piece milled zirconia post and core using CAD/CAM (computer-aided design/computer-aided manufacturing) technique. Purpose: The objective of this study was to compare microleakage of endodontically treated teeth restored with three different tooth-colored post and cores. Material and methods: Extracted 27 human maxillary incisors were cut at the cementoenamel junction, and the teeth were endodontically treated. Teeth were divided into 3 groups (n=9); restored with fiber post and resin core, prefabricated zirconia post and heat-pressed ceramic core, and CAD/CAM milled zirconia post and core. After the preparation of post space, each post was cemented with dual-polymerized resin cement (Variolink II). Teeth were thermocycled for 1000 cycles between 555C and dyed in 2% methylene blue at 37C for 24 hours. Teeth were sectioned (bucco-lingual), kept the record of microleakage and then image-analyzed using a microscope and computer program. The data were analyzed by one-way ANOVA and Scheffe's multiple range test (α=0.05). Results: All groups showed microleakage and there were no significant differences among the groups (P>.05). Prefabricated zirconia post and heat-pressed ceramic core showed more leakage in dye penetration at the post-tooth margin, but there was little microleakage at the end of the post. Fiber post and resin core group and CAD/CAM milled zirconia post and core group indicated similar microleakage score in each stage. Conclusion: Prefabricated zirconia post and heat-pressed ceramic core group demonstrated better resistance to leakage, and fiber post and resin core group and CAD/CAM milled zirconia post and core group showed the similar patterns. The ANOVA test didn't indicate significant differences in microleakage among test groups. (P>.05)

Heterogeneous multi-core simulator based on SMP for the efficient application development at the heterogenous multi-core environment (효과적인 이기종 다중코어 응용 개발을 위한 SMP기반 이기종 다중코어 시뮬레이터)

  • SaKong, June;Shin, Dongha
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.3
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    • pp.111-117
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    • 2018
  • Heterogeneous multi-core environment integrated with different functional cores is the powerful tool for the embedded system that became more complex and diverse. Specialized application requires one chip solution with different operating system over different cores. But this heterogeneity causes difficult configuration of the development environment, makes hard to develop and test software. We show the environment of heterogeneous multi-core processing can be mapped to symmetric multi-core environment. We construct Linux based RPMsg for the data exchange between processes similar with the heterogeneous multi-core RPMsg and experiment that the proposed environment can be used to reduce the steps of the heterogeneous multi-core application development. With this simplification, we suggest simulation method for easy development and debugging the heterogeneous multicore environment that makes complex steps to simple.

Multicore DVFS Scheduling Scheme Using Parallel Processing for Reducing Power Consumption of Periodic Real-time Tasks (주기적 실시간 작업들의 전력 소모 감소를 위한 병렬 수행을 활용한 다중코어 DVFS 스케줄링 기법)

  • Pak, Suehee
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.12
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    • pp.1-10
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    • 2014
  • This paper proposes a scheduling scheme that enhances power consumption efficiency of periodic real-time tasks using DVFS and power-shut-down mechanisms while meeting their deadlines on multicore processors. The proposed scheme is suitable for dependent multicore processors in which processing cores have an identical speed at an instant, and resolves the load unbalance of processing cores by exploiting parallel processing because the load unbalance causes inefficient power consumption in previous methods. Also the scheme activates a part of processing cores and turns off the power of unused cores. The number of activated processing cores is determined through mathematical analysis. Evaluation experiments show that the proposed scheme saves up to 77% power consumption of the previous method.

A Fundamental Study on the Influence of Performance of Cementitious Composites of Inorganic Core Material for Self-Healing Capsule of Cracks (균열 자기치유를 위한 캡슐용 무기계 코어재료의 시멘트 복합체 성능에 미치는 영향에 관한 기초적 연구)

  • Choi, Yun-Wang;Oh, Sung-Rok;Choi, Byung-Keol;Kim, Cheol-Gyu
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.21 no.1
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    • pp.74-82
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    • 2017
  • In this study, we prepared a core material based on the inorganic materials in liquid form for applying an inorganic-based core material to a core material for the self-healing capsules as a part of the basic study to manufacture of self-healing capsule that can heal cracks of cementitious composite. Manufactured core material based on the inorganic materials were applied directly to the cement composite before its encapsulation, were evaluated the effect on performance of cementitious composite as wall as repair performance of the cracks in the cracks. The test results showed that core material based on the inorganic materials was effective to improve the compressive and adhesion strength, had an absorption, permeation water, penetration of chloride iones and freeze-thaw resistance performance. Through the results of this paper, we want to utilize the results as a basis data of the performance of the cement composite that can be obtained when applied to inorganic core materials based on self-healing capsules and future advances localized self-healing capsule technology.