• 예술인문사회 융합 멀티미디어 논문지
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• 제7권9호
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• pp.215-223
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• 2017

재미있는 게임을 만들기 위해 다양한 측정기법들이 개발 과정에서 사용된다. 경험적인 부분에 대해서는 측정 및 분석이 어렵기 때문에 일반적으로 데이터를 수치화하기 쉬운 부분에 대해서만 측정, 분석하게 된다. 이는 게임의 재미는 경험적인 부분이 중요하다는 점에서 한계가 명확한 방법이다. 본 연구는 게임을 진행하는 사용자의 경험을 손쉽게 수치화하기 위하여 게임 사용자의 안면을 인식하고 인식된 정보로부터 감정 변화를 측정하는 기술을 활용하는 시스템을 제안한다. 시스템은 게임을 진행하는 사용자의 안면으로부터 실시간으로 감정을 인식하고 수치화하여 기록한다. 이렇게 기록된 데이터에는 시간 및 게임 진행과 관련된 수치, 안면으로부터 인식된 감정에 대한 수치 등이 포함된다. 기록된 데이터를 이용하면 특정 시점에서 게임이 사용자에게 어떤 감정을 유도하는지 판단할 수 있게 된다. 본 연구의 시스템을 활용하여 기록된 경험적인 부분에 대한 수치 데이터는 게임을 개발자의 의도대로 개발하는데 도움을 줄 수 있을 것으로 기대한다.

• 한국재난정보학회 논문집
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• 제3권1호
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• pp.37-53
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• 2007

Various difficult problems occur due to insufficient bearing capacity or excessive settlements when constructing roads or large complexes. Accurate predictions on the final settlement and consolidation time can help in choosing the ground improvement method and thus enables to save time and expense of the whole project. Asaoka's method is probably the most frequently used for settlement prediction which are based on Terzaghi's one dimensional consolidation theory. Empirical formulae such as Hyperbolic method and Hoshino's method are also often used. However, it is known that the settlement predicted by these methods do not match with the actual settlements. Furthermore these methods cannot be used at design stage when there is no measured data. To find an elaborate method in predicting settlement in embankments using various test results and actual settlement data from domestic sites, Back-Propagation Neural Network(BPNN) and Recurrent Neural Network(RNN) were employed and the most suitable model structures were obtained. Predicted settlement values by the developed models were compared with the measured values as well as numerical analysis results. Analysis of the results showed that RNN yielded more compatible predictions with actual data than BPNN and predictions using cone penetration resistance were closer to actual data than predictions using SPT results. Also, it was found that the developed method were very competitive with the numerical analysis considering the number of input data, complexity and effort in modelling. It is believed that RNN using cone penetration test results can make a highly efficient tool in predicting settlements if enough field data can be obtained.

• 전산구조공학
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• 제6권1호
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• pp.127-135
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• 1993

본 논문은 에너지 분산장치의 일종인 점탄성 감쇠기를 설치한 건물의 거동에 관한 연구이다. 평상온도에서 뿐만아니라 높은 주변온도 하에서도 점탄성 감쇠기를 설치한 건물은 이를 설치하지 않은 건물에 비해서 구조응답이 현저히 감소함을 나타낸다. 감쇠기에 대한 실험에서 얻은 결과를 회귀분석하여 감쇠기의 동적특성을 산정할 수 있는 실험식을 유도한다. 감쇠기를 설치한 건물의 구조감쇠는 모드 변형에너지법과 유도된 실험식을 이용하여 성공적으로 예측할 수 있다. 또한, 점탄성 감쇠된 건물의 지진하중에 의한 동적 구조응답을 예측하기 위하여 수치모형해석을 수행한다. 수치모형해석의 결과는 실험결과와 잘 일치하는 것으로 나타나 일반적인 모드해석방법에 의해 점탄성 감쇠기를 설치한 건물의 동적거동을 정확하게 예측할 수 있음을 보여준다. 이러한 결과를 토대로, 점탄성 감쇠기를 설치한 건물에 대한 설계방법을 제시한다. 이 설계방법은 일반적인 건물의 설계에 감쇠비라는 설계요소를 추가함으로서 가능해진다.

• Geomechanics and Engineering
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• 제13권4호
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• pp.671-683
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• 2017

Groundwater control is a significant issue in most underground construction. An estimate of the inflow rate is required to size the pumping system, and treatment plant facilities for construction planning and cost assessment. An estimate of the excavation-induced drawdown of the initial groundwater level is required to evaluate potential environmental impacts. Analytical and empirical methods used in current engineering practice do not adequately account for the effect of the jointed-rock-mass anisotropy and heterogeneity. The impact of geostructural anisotropy of fractured rocks on tunnel inflows is addressed and the limitations of analytical solutions assuming isotropic hydraulic conductivity are discussed. In this paper the unexcavated Zagros tunnel route has been classified from groundwater flow point of view based on the combination of observed water inflow and numerical modeling results. Results show that, in this hard rock tunnel, flow usually concentrates in some areas, and much of the tunnel is dry. So the remaining unexcavated Zagros tunnel route has been categorized into three categories including high Risk, moderately risk and low risk. Results show that around 60 m of tunnel (3%) length can conduit the large amount of water into tunnel and categorized into high risk zone and about 45% of tunnel route has moderately risk. The reason is that, in this tunnel, most of the water flows in rock fractures and fractures typically occur in a clustered pattern rather than in a regular or random pattern.

• 물과 미래
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• 제18권1호
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• pp.85-94
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• 1985

수치해법와 경험적 방법을 합성함으로써 하천수문곡선의 기저유출을 분리하는 방법을 개발하였다. 기저유출 감수곡선에 대해서는 선형화된 Boussinesq 방정식과 저유함수를 적용하였으며, 또한 강우에 의하여 지하의 대수층에 침투된 량이 하천으로 유입되는 기저유출의 추정에는 Singh과 Stall의 도식적 방법을 이용하였다. 이들에대한 시간별 연속성은 다원적인 다항식 회귀론에 의하여 근사화시켰다. 본 연구과정은 자연하천에 성공적으로 적용할 수 있었으나, 감수곡선을 위한 동차선형2단상징분계의 직접적 수치해법은 부적합한 것으로 나타났으며, 손실이 발생되는 부분침투천의 기저유량은 본 연구방법에 의하여 추정할 수 없었다.

• 한국압력기기공학회 논문집
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• 제13권2호
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• pp.51-59
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• 2017

Steam jets ejected from a rupture zone of high energy pipes may cause damage to adjacent structures. This event could lead to more serious accidents in nuclear power plants. Therefore, to prevent serious accidents, high energy pipes of nuclear power plants are designed according to the ANSI / ANS 58.2 technical standard. However, the US Nuclear Regulatory Commission (USNRC) has recently pointed out non-conservatism in existing high energy pipe fracture evaluation methods, and required the assessment of the unsteady load of the jet caused by a potential feedback mechanism as well as the impact range of steam jet, the jet impact loads and the blast wave effects at the initial breakage stage. The potential feedback mechanism refers to a phenomenon in which a vortex formed by impingement jets amplifies vortex itself and induces jet vibration in a shear layer. In this study, CFD methodology using the LES turbulence model is established and numerical analysis is carried out to evaluate the dynamic behavior of impingement jets and the potential feedback mechanism during jet impingement. Obtained results have been compared with an empirical correlation and experiment.

• Computers and Concrete
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• 제3권1호
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• pp.17-28
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• 2006

Replacement of actual stress distribution in a reinforced concrete (RC) flexural member with a simpler geometrical shape, which maintains magnitude and location of the resultant compressive force, is an acceptable conceptual trick. This concept was originally perfected for normal strength concrete. In recent years, high strength concrete (HSC) has been introduced and widely used in modern construction. The stress block parameters require updating to account for special features of HSC in the design of flexural members. In future, more varieties of concrete may be developed and a corresponding design procedure of RC flexural members will be required. The usual practice is to conduct large number of experiments on various sizes of specimen and then evolve an empirical relation. This paper presents a numerical procedure through which the stress block parameters can be numerically derived for a given strain ratio variation. The material model for concrete is presented and computational procedure is described. This procedure is illustrated with several variations of strain ratio. The advantages of numerical procedure are that it costs less and it can be used with new material models for any new variety of concrete.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
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• pp.294-298
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• 2003

The complex, unsteady, self-sustained pressure oscillations induced by supersonic flow past a rectangular cavity is investigated using numerical simulations. The present numerical study is performed using a parallel, multiblock solver for the two-dimensional, compressible Navier­Stokes equations. Open cavities with length-to-depth (L / D) ratio in the range 0.5 - 3.3 are considered. This paper sheds light on the cavity physics, cavity oscillatory mechanism, and the organisation of vortical structures inside the cavity. The vortex shedding phenomenon, the shear layer impingement event at the aft wall and the movement of the acoustic/compression wave within the cavity are well predicted. The vortical structures· and the source of the acoustic disturbances are found to be located near the aft wall of the cavity. With the increase in the cavity length, strong recompression of the flow near the aft wall leading to a sudden jump in the cavity form drag is observed. The estimated cavity tones are in good agreement with the available semi­empirical relation. Multiple peaks are noticed in deep and long cavities. For the present free­stream Mach number 1.71, it is observed that around L/D=2.0, the cavity oscillatory mechanism changes from the transverse to longitudinal oscillatory mode. The effects of this transition on various fluid dynamics and acoustic properties are also discussed.

• 대한기계학회논문집A
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• 제33권12호
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• pp.1464-1470
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• 2009

RBDO approach based on a sampling method with the Kriging metamodel and Constraint Boundary Sampling (CBS), which is sequential sampling method to generate metamodels is proposed. The major advantage of the proposed RBDO approach is that it does not require Most Probable failure Point (MPP) which is essential for First-Order Reliability Method (FORM)-based RBDO approach. The Monte Carlo Sampling (MCS), most well-known method of the sampling methods for the reliability analysis is used to assess the reliability of constraints. In addition, a Cumulative Distribution Function (CDF) of the constraints is approximated using Moving Least Square (MLS) method from empirical distribution function. It is possible to acquire a probability of failure and its analytic sensitivities by using an approximate function of the CDF for the constraints. Moreover, a concept of inactive design is adapted to improve a numerical efficiency of the proposed approach. Computational accuracy and efficiency of the proposed RBDO approach are demonstrated by numerical and engineering problems.

• Geomechanics and Engineering
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• 제20권1호
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• pp.75-86
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• 2020

This study aims to simulate the stabilization process of fibrous peat samples using end-bearing Cement Deep Mixing (CDM) columns by three area improvement ratios of 13.1% (TS-2), 19.6% (TS-3) and 26.2% (TS-3). It also focuses on the determination of approximate stress distribution between CDM columns and untreated fibrous peat soil. First, fibrous peat samples were mechanically stabilized using CDM columns of different area improvement ratio. Further, the ultimate bearing capacity of a rectangular foundation rested on the stabilized peat was calculated in stress-controlled condition. Then, this process was simulated via a FEM-based model using Plaxis 3-D foundation and the numerical modelling results were compared with experimental findings. In the numerical modelling stage, the behaviour of fibrous peat was simulated based on hardening soil (HS) model and Mohr-Coulomb (MC) model, while embedded pile element was utilized for CDM columns. The results indicated that in case of untreated peat HS model could predict the behaviour of fibrous peat better than MC model. The comparison between experimental and numerical investigations showed that the stress distribution between soil (S) and CDM columns (C) were 81%C-19%S (TS-2), 83%C-17%S (TS-3) and 89%C-11%S (TS-4), respectively. This implies that when the area improvement ratio is increased, the share of the CDM columns from final load was increased. Finally, the calculated bearing capacity factors were compared with results on the account of empirical design methods.