• 전자공학회논문지CI
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• 제42권5호
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• pp.1-8
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• 2005

SPEC CPU2000은 CPU의 성능 측정에 중점을 둔 벤치마크 프로그램으로서 표준화에 대한 노력을 바탕으로 산학계에 널리 사용되고 있으나, 하드웨어 측면에서의 특성 분석은 미비하였다. 본 논문에서는 컴퓨터 시스템의 중요한 구성 요소 중 하나인 CPU 주파수 속도의 변화에 따른 SPEC CPU2000 벤치마크의 성능 변화를 고찰하였다. x86 구조 기반의 단일 프로세서 시스템에서 CPU 주파수 속도를 제외한 다른 구성요소를 일정하게 유지하면서 SPEC CPU2000 벤치마크 프로그램의 성능을 측정함으로써 SPEC CPU2000 벤치마크 프로그램의 특성을 시스템적 측면에서 해석하였다. 실험을 통하여 SPEC CPU2000은 CPU 주파수 속도의 변화에 대하여 유연한 성능분석이 가능하도록 개별 벤치마크 프로그램의 CPU 주파수 의존도가 고르게 분포되어 있음을 알 수 있었으며, SPEC CPU2000에 대한 시스템적 측면의 해석을 제공함으로써 SPEC CPU2000을 사용하는 연구, 개발에 있어서 기반 자료로 사용될 것으로 기대된다.

• 응용통계연구
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• 제25권3호
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• pp.389-401
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• 2012

This paper derives a benchmark dose(BMD) and its 95% lower confidence limit(BMDL) using a semi-parametric regression model for small lead based changes in attention-deficit hyperactivity disorder(ADHD) scores in the first wave of the Children's Health and Environment Research(CHEER) survey data, which have been regularly collected in South Korea since 2005. Ha et al. (2009) showed that the appearance of ADHD symptoms had a borderline trend of increasing with the blood lead concentration. Butdz-J${\o}$rgensen (EFSA, 2010a) derived the BMDL of lead corresponding to a benchmark region of 1 full intelligent quotient (IQ) score using the raw data in Lanphear et al. (2005, EHP). European Food Safety Authority (EFSA, 2010b) determined the BMDL of $1.2{\mu}g/dl$ as a reference point for the characterization of lead when assessing the risk of the intellectual deficit measured by IQ scores. Kim et al. (2011) indicated that an even lower BMDL could be obtained based on the ADHD score; however, the BMDLs depended heavily upon the model assumptions. We show in this paper that a semi-parametric approach resolves the model dependence of BMDLs.

• Wind and Structures
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• 제34권1호
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• pp.101-113
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• 2022

We experimentally investigate the high-Reynolds flow around a rectangular cylinder of aspect ratio 5:1. This configuration is the object of the international BARC benchmark. Wind tunnel tests have been carried out for the flow at zero angle of attack and a Reynolds number, based on the crossflow cylinder length and on the freestream velocity, equal, to 40 000. Velocity measurements are obtained by using hot-wire anemometry along 50 different cross-flow traverses on the cylinder side and in the near wake. Differential pressure measurements are acquired on multiple streamwise sections of the model. The obtained measurements are in a good agreement with the state-of-the-art experiments. For the first time among the several contributions to the BARC benchmark, detailed flow measurements are acquired in the region near the cylinder side and in the near-wake flow. The edges and the thickness of the shear layers detaching from the upstream edges are derived from velocity measurements. Furthermore, we compute the flow frequencies characterizing the roll-up of the shear layers, the evolution of vortical structures near the cylinder side and the vortex shedding in the wake.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 추계학술발표회논문집(1)
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• pp.191-196
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• 1997

As a part of International Criticality Safety Benchmark Evaluation Project (ICSBEP), SAXTON critical experiments were reevaluated. The effects on $K_{eff}$ of the uncertainties in experiment parameters, fuel rod characterization, soluble boron, critical water level, core structure, $^{241}$ Am and $^{241}$ Pu isotope number densities, random pitch error, duplicated experiment, axial fuel position, model simplification, etc., were evaluated and added in benchmark-model $k_{eff}$. In addition to detailed model, the simplified model for Saxton critical experiments was constructed by omitting the top, middle, and bottom grids and ignoring the fuel above water.r.r.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.771-772
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• 2008

In this paper, we analyze the characterization of Mibench, an embedded system benchmark program, using simplescalar simulator. The experimental results show Mibench generally is formed by lots of integer and memory access instructions. Especially, IPC of rijndael decoding is effected by cache size largely, but IPC of CRC32 is few effected by cache size or branch predicting algorithm.

• Journal of Computing Science and Engineering
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• 제9권1호
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• pp.20-28
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• 2015

General purpose computing applications have not yet been thoroughly explored in procedure level speculation, especially in the light-weighted profiling way. This paper proposes a light-weighted profiling mechanism to analyze speculative parallelism characterization in several classic general purpose computing applications from SPEC CPU2000 benchmark. By comparing the key performance factors in loop and procedure-level speculation, it includes new findings on the behaviors of loop and procedure-level parallelism under these applications. The experimental results are as follows. The best gzip application can only achieve a 2.4X speedup in loop level speculation, while the best mcf application can achieve almost 3.5X speedup in procedure level. It proves that our light-weighted profiling method is also effective. It is found that between the loop-level and procedure-level TLS, the latter is better on several cases, which is against the conventional perception. It is especially shown in the applications where their 'hot' procedure body is concluded as 'hot' loops.

• JSTS:Journal of Semiconductor Technology and Science
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• 제9권1호
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• pp.29-36
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• 2009

Power supply noise is fundamentally caused by large current peaks. Since large current peaks are induced by simultaneous switching of many circuit elements, power supply noise can be minimized by deliberate clock scheduling which utilizes nonzero clock skew. In this paper, nonzero skew clock scheduling is used to avoid the large peak current and consequently reduce power supply noise. While previous approaches require extra characterization efforts to acquire current waveform of a circuit, we approximate it only with existing cell library information to be easily adapted to conventional design flow. A simulated annealing based algorithm is performed, and the peak current values are estimated for feasible clock schedules found by the algorithm. The clock schedule with the minimum peak current is selected for a solution. Experimental results on ISCAS89 benchmark circuits show that the proposed method can effectively reduce the peak current.

• Structural Engineering and Mechanics
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• 제81권5호
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• pp.647-664
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• 2022

The powerful data mapping capability of computational deep learning methods has been recently explored in academic works to develop strategies for structural health monitoring through appropriate characterization of dynamic responses. In many cases, these studies concern laboratory prototypes and finite element models to validate the proposed methodologies. Therefore, the present work aims to investigate the capability of a deep learning algorithm called Sparse Autoencoder (SAE) specifically focused on detecting structural alterations in real-case studies. The idea is to characterize the dynamic responses via SAE models and, subsequently, to detect the onset of abnormal behavior through the Shewhart T control chart, calculated with SAE extracted features. The anomaly detection approach is exemplified using data from the Z24 bridge, a classical benchmark, and data from the continuous monitoring of the San Vittore bell-tower, Italy. In both cases, the influence of temperature is also evaluated. The proposed approach achieved good performance, detecting structural changes even under temperature variations.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.563-564
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• 2014

Recent developments in the prediction of the contribution of windnoise to the interior SPL have opened a realm of new possibilities in terms of i) how the convective and acoustic sources terms can be identified, ii) how the interaction between the source terms and the side glass can be described and finally iii) how the transfer path from the sources to the interior of the vehicle can be modelled. This work discusses several simulation methods that can be used to represent the physical phenomena involved such as CFD, FEM, BEM, FE/SEA Coupled and SEA. This work focuses on the validation of the wind noise source characterization method and the vibro-acoustic models on which the wind noise sources are applied in the framework of a benchmark proposed by Hyundai Motors Corporation.

• 방사성폐기물학회지
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• 제21권1호
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• pp.23-41
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• 2023

Coupled thermo-hydraulic-mechanical (THM) processes are essential for the long-term performance of deep geological disposal of high-level radioactive waste. In this study, a numerical sensitivity analysis was performed to analyze the effect of rock properties on THM responses after the execution of the heater test at the Kamaishi mine in Japan. The TOUGH-FLAC simulator was applied for the numerical simulation assuming a continuum model for coupled THM analysis. The rock properties included in the sensitivity study were the Young's modulus, permeability, thermal conductivity, and thermal expansion coefficients of crystalline rock, rock salt, and clay. The responses, i.e., temperature, water content, displacement, and stress, were measured at monitoring points in the buffer and near-field rock mass during the simulations. The thermal conductivity had an overarching impact on THM responses. The influence of Young's modulus was evident in the mechanical behavior, whereas that of permeability was noticed through the change in the temperature and water content. The difference in the THM responses of the three rock type models implies the importance of the appropriate characterization of rock mass properties with regard to the performance assessment of the deep geological disposal of high-level radioactive waste.