• Title/Summary/Keyword: Threaded

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DVFS based Memory-Contention Aware Scheduling Method for Multi-threaded Workloads (멀티쓰레드 워크로드를 위한 DVFS 기반 메모리 경합 인지 스케줄링 기법)

  • Nam, Yoonsung;Kang, Minkyu;Yeom, HeonYoung;Eom, Hyeonsang
    • KIISE Transactions on Computing Practices
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    • v.24 no.1
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    • pp.10-16
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    • 2018
  • The task of consolidating server workloads is critical for the efficiency of a datacenter in terms of reducing costs. However, as a greater number of workloads are consolidated in a single server, the performance of workloads might be degraded due to their contention to the limited shared resources. To reduce the performance degradation, scheduling for mitigating the contention of shared resources is necessary. In this paper, we present the Dynamic Voltage Frequency Scaling (DVFS) based memory-contention aware scheduling method for multi-threaded workloads. The proposed method uses two approaches: running memory-intensive threads on the limited cores to avoid concurrent memory accesses, and reducing the frequencies of the cores that run memory-intensive threads. With the proposed algorithm, we increased performance by 43% and reduced power consumption by 38% compared to the Completely Fair Scheduler(CFS), the default scheduler of Linux.

A PHOTOELASTIC ANALYSIS OF STRESS DISTRIBUTIONS AROUND FIVE DIFFERENT TYPES OF ENDOSSEOUS IMPLANTS ACCORDING TO THEIR STRUCTURES (5종 골내 임플란트의 구조에 따른 주위의 응력분산에 관한 광탄성학적 연구)

  • Lee Jeong-Nam;Cho Sung-Am
    • The Journal of Korean Academy of Prosthodontics
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    • v.31 no.4
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    • pp.643-659
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    • 1993
  • This study was performed for the purpose of evaluating the stress distributions around five different types of implants according to their structures. The stress distribution around the surrounding bone was analysed by two-dimensional photoelastic method. Five epoxy resin models were made, and vertical and lateral forces were applied to the models. A circular polariscope was used to record the isochromatic fringes. The results of this study were summerized as follows : 1. Threaded type implants showed more even stress distribution patterns than cylinderical type implants when vertical and lateral forces were applied. 2. The stress concentrated patterns were observed at the neck portion and middle portion of the cylindrical type implants comparing with threaded type implants when vertical force was applied. 3. Model 1 and model 4 which are tthreaded type implants showed similar stress distribution patterns at the middle and apical portions and more stress was concentrated at the neck porion of model 1 comparing with model 4 when vertical force was applied. The stresses around model 1 were more evenly distributed when lateral force was applied. 4. More stress was concentrated at the neck and middle portion of cylindrical type implants than threaded type implants when lateral force was applied. 5. Model 1 showed the most even stress distribution patterns when lateral force was applied and stress distribution did no occured at the apical portion of modedl 2 when lateral force was applied. 6. There were almost no differences in stress concentrated patterns with or without having hollow design. And the stress concentrated patterns were observed at the corner of apex in model 5 which has hollow design when vertical force was applied.

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3-D Finite Element Analysis of Acetabular Reconstruction of THR (인공고관절 전치환술에 있어서 비구 재건 술에 관한 3차원 유한요소해석)

  • Ryu, J.C.;Mun, M.S.;Kim, G.S.;Yoo, M.C.
    • Proceedings of the KOSOMBE Conference
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    • v.1995 no.11
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    • pp.34-38
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    • 1995
  • Using a 3-D finite element method (FEM), the biomechanical characteristics of a threaded truncated acetabular component and a porous coated hemispherical acetabular component were studied. The Von-Mises stress/strain patterns in the acetabulum reconstructed with these two different types of cementless acetabular cups were investigated. The geometry and dimensions of human hemi-pelvis used in the present shape modeling for finite element analysis were scanned with a 3-D laser scanner(TDS-9000, Cyberware, USA). The scanned data was numerically handled with a shape modelling software 'Pro-Engineer'. Using 19836, 16853 tetrahedral elements, respectively, the stress and displacement field of the acetabulum reconstructed with the two different types of the acetabular components were computed. While the hemi-sphere component was found to show a relatively similar stress/strain patterns to those in the normal hip, the results with the threaded cup showed a considerably different patterns from those in the normal condition. Several regions in cancellous bone near the threads and the edge of the truncated cup was found to be overstressed, especially in the superior-lateral part of the acetabulum. It was postulated that the excessive reaming-out of subchondral bone layer when the truncated cup was used can cause the presence of these overstressed regions of cancellous bone. This theoretical prediction for the implanted acetabulum appeared to consistent with the pathological observation of proximal/medial migration of the threaded truncated acetabular prostheses in the previous publications.

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Verification for Multithreaded Java Code using Java Memory Model (자바 메모리 모델을 이용한 멀티 스레드 자바 코드 검증)

  • Lee, Min;Kwon, Gi-Hwon
    • The KIPS Transactions:PartD
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    • v.15D no.1
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    • pp.99-106
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    • 2008
  • Recently developed compilers perform some optimizations in order to speed up the execution time of source program. These optimizations require the reordering of the sequence of program statements. This reordering does not give any problems in a single-threaded program. However, the reordering gives some significant errors in a multi-threaded program. State-of-the-art model checkers such as JavaPathfinder do not consider the reordering resulted in the optimization step in a compiler since they just consider a single memory model. In this paper, we develop a new verification tool to verify Java source program based on Java Memory Model. And our tool is capable of handling the reordering in verifying Java programs. As a result, our tool finds an error in the test program which is not revealed with the traditional model checker JavaPathFinder.

Design and Implementation of CORBA based on Multi-Threaded in Open Network Environments (개방형 네트워크 환경을 위한 멀티쓰레드 기반 코바 설계 및 구현)

  • Jang, Jong-Hyeon;Lee, Dong-Gil;Han, Chi-Mun
    • The KIPS Transactions:PartC
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    • v.9C no.2
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    • pp.213-220
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    • 2002
  • Distributed competing system gives a new system architecture to be taken into consideration for solving the problems of interoperability of heterogeneous systems. In the present paper, CORBA based on multi-threaded interoperates with software blocks at physically isolated hardware. We show how archives optimal CORBA system from analysis of required functions, implementations of protocols and benchmarking of system performance in the Open Multi-service Network System Environment. The core features of our CORBA system are restricted Quality of Service based on priority, timeout service and exception status information notify to the related software blocks. And the objectives are design and implementation of high performance multi-threaded middleware and satisfied with extendibility, flexibility and stability of CORBA platform.

Estimation of Yield strength and Slip Modulus for Helically Threaded Nail Connection (나선형 철선못 접합부의 항복내력 및 강성 예측)

  • Hwang, Kweonhwan;Shim, Kug-Bo
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.6
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    • pp.524-530
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    • 2009
  • In the post-beam structure, the infilled light-frame construction provides most shear strengths. Shear properties of the light-frame structure can be estimated from the shear properties of nailed connection for the sheathings, and those of nailed connections can be done from nail bending strengths. For the basic study to predict the yield strength and the slip modulus of a nailed sheathing shear wall, those of a nailed joint were examined from nail bending strengths. To estimate shear properties of a nailed connection, referenced bearing strength and bearing constant for the wood members and the experimental nail bending strengths of the helically threaded nail were applied. The yield strength using the diameter at grooves instead of shank diameter was well coincided with the experimental value, but the slip modulus was estimated much smaller. The effective factors, specific gravity for the main member, withdrawal by nail head diameter to the side member, and embedment and moment at the nail head were considered, and further examinations are needed for the precise prediction of the nailed connections.

Minimally Invasive Posterior Lumbar Interbody Fusion with Threaded Fusion Cage(TFC) (Threaded Fusion Cage(TFC)를 이용한 최소 침습적 요추체 후방융합술)

  • Kim, Hyeok Joon;Cho, Ki Hong;Shin, Yong Sam;Yoon, Soo Han;Cho, Kyung Gi
    • Journal of Korean Neurosurgical Society
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    • v.30 no.sup2
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    • pp.247-253
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    • 2001
  • Objective : In general, to perform posterior lumbar interbody fusion(PLIF), it has been used more invasive procedure than simple discectomy. However we try to perform PLIF with TFC with smaller invasion almost same as in simple discectomy. This study is about its procedure and clinical results. Materials and Methods : The authors retrospectively analyzed 43 cases of minimally invasive PLIF with TFC from July 1998 to May 2000. Operative procedure, operative complication, change of disc height, blood loss, ambulation time, hospitalization period, clinical success rate, and bony fusion rate were analyzed. Results : 40 patients were capable to walk on the 2nd day of the post-operation. The average hospitalization period is 5.6 days. The average blood loss was 0.19L/level with no transfusion or wound drainage. The height of disc changed from 8.84mm to 13.54mm. Clinical success rate is 95% when evaluated by the Prolo's scale. The complication was delayed wound infection(2) and transient paresthesis(1). The bony fusion was shown in 17 patients (94.4%) out of 18 patients who passed one year. Conclusion : As a result of minimally invasive PLIF, pain was decreased and early ambulation and short hospitalization was possible. Complication was similar or lower than other studies, and the bony fusion rate and clinical success rate were also similar during follow-up.

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Experimental Study on Field Applicability of Tightened Coupler with Two-Way Threading (양방향 나사산 체결방식을 활용한 완전밀착형 커플러의 시공성 분석)

  • Park, U-Yeol;Hong, Seong-Wook;Yang, Jin-Kook;Ko, Suck-Hwa;An, Sung-Hoon
    • Journal of the Korea Institute of Building Construction
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    • v.14 no.1
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    • pp.87-93
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    • 2014
  • A tightened coupler with two way-threading is suggested to overcome the previous one-way threaded coupler. The experiment and a mock-up test were conducted to analyze the constructability of the suggested coupler. The aim of the mock-up test was to assemble the suggested coupler in horizontal rebar of mat footing and vertical rebar of semi-fabricated column bars. The method using the suggested coupler in semi-fabricated column bars is developed by analyzing the problem of fabricated column bars using the one-way threaded coupler. The result of the mock-up test showed that the time required to assemble the suggested coupler in the horizontal bars is shorter than it is for the one-way threaded coupler. In addition, the method using the suggested coupler in semi-fabricated column bars has advantages such as lower working loads, supporting safe work and strongly tightening the rebar. From these results, it is revealed that the suggested coupler is adequate to use in rebar work in terms of cost, quality and time.