• Structural Engineering and Mechanics
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• v.40 no.5
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• pp.617-636
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• 2011

We present the numerical implementation, simulation, and validation of the high-velocity impact experiments that have been described in the companion article. In this part, numerical investigations and simulations performed to mimic the tests are presented. The experiments were analyzed by the explicit integration-based software ABAQUS for improved simulations. Targets were modeled with a damaged plasticity model for concrete. Computational results of residual velocity and crater dimensions yielded acceptable results.

• Elastomers and Composites
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• v.6 no.2
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• pp.73-79
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• 1971

As a series of the studies of EPDM-Polymer blends, the experiments are concentrated to the investigation of the physical properties of the EPDM-SBR blends. The results are shown as follows: 1. Tensile strength decreased with increase in EPDM contents and the decreasing value was good results than NR blending. 2. It was found that the aging were much improved after blending and experiments data was good results than NR blending.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.56-56
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• 2000

In this paper, the relationship between GPS code and carrier tracking performance is given. Through the error analysis and experiments, the performance of code tracking loop can be improved using narrow correlation. The performance of code tracking loop can be also improved if the better carrier tracking loop is used. On the other hand, the performance of carrier tracking loop is independent of that of code tracking loop.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.97-100
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• 2009

A negative waveform was studied to improve the driving characteristics of reset and address periods in ac PDP. Comparative experiments between negative and conventional positive waveforms were performed with 42-inch XGA PDP module. The negative waveform showed lower breakdown voltage than the conventional positive waveform in reset period. Due to its weak and stable discharge during reset period, the contrast ratio was improved by decreasing the black luminance. During address period, the discharge time-lag was measured. The formative time lag ($=T_f$) of negative waveform was improved about 22.8% than $T_f$ of conventional positive waveform.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.4
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• pp.12-23
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• 2004

The effects of improved rice bran oil on the characteristics of exhaust emissions have been experimentally examined by a single cylinder, four cycle, direct injection, water-cooled agricul-tural diesel engine operating at several loads and speeds. The experiments are conducted with light oil, rice bran oil, and improved rice bran oil as a fuel. The fuel injection timing is fixed to 22$^{\circ}$ BTDC regardless of fuel types, engine loads and speeds. To reduce the viscosity of rice bran oil, it is used with the methods of heating, methyl ester and ultrasonic system in a highly viscous rice bran oil. In this study, it is found that the brake specific fuel consumption rate of light oil is the lowest and that of improved rice bran oils is lower than that of pure rice bran oil, and NO$_{x}$ emissions of light oil are the lowest and those of pure rice bran oil are the high- est, while soot emissions of light oil are the highest and those of pure and improved rice bran oils are lower than that of light oil. However these results are not amply satisfied with the emissions regulation limit using the pure and improved rice bran oil as fuels in diesel engines.s.

• Journal of the Korea Safety Management & Science
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• v.6 no.2
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• pp.141-154
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• 2004

The objective of this paper is to develop the efficient heuristic method for solving the minimum makespan problem of the job shop scheduling. The proposed heuristic method is based on a constraint satisfaction problem technique and a improved randomizing search algorithm. In this paper, ILOG programming libraries are used to embody the job shop model, and a constraint satisfaction problem technique is developed for this model to generate the initial solution. Then, a improved randomizing search algorithm is employed to overcome the increased search time of constrained satisfaction problem technique on the increased problem size and to find a improved solution. Computational experiments on well known MT and LA problem instances show that this approach yields better results than the other procedures.

• Journal of the Korea Society of Computer and Information
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• v.23 no.7
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• pp.57-62
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• 2018

In this paper, we propose an improved algorithm for rendering method to guarantee frame rates based on HMD (Head Mounted Display) motion in an avionics simulator. One of important issues in HMD simulators is to guarantee frame rates despite fast motion of HMD which is more rapid than the aircraft's moving speed to maintain a quality of images. Therefore, we propose an algorithm considering the moving speed of a pilot's head: Improved Speed-Based LOD (Level-Of-Detail) Control (ISBLC). In the proposed algorithm, frame rates are improved by changing dynamic LOD which determines details of objects for rendering images. Throughout the experiments, we show the average frame rates are achieved up to 60 and minimum frame rates are guaranteed up to 40. The proposed algorithms will be used HMD simulation in avionics simulators.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.3
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• pp.1243-1263
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• 2018

The two-stage linear discrimination analysis (TSLDA) is a feature extraction technique to solve the small size sample problem in the field of image recognition. The TSLDA has retained all subspace information of the between-class scatter and within-class scatter. However, the feature information in the four subspaces may not be entirely beneficial for classification, and the regularization procedure for eliminating singular metrics in TSLDA has higher time complexity. In order to address these drawbacks, this paper proposes an improved two-stage linear discriminant analysis (Improved TSLDA). The Improved TSLDA proposes a selection and compression method to extract superior feature information from the four subspaces to constitute optimal projection space, where it defines a single Fisher criterion to measure the importance of single feature vector. Meanwhile, Improved TSLDA also applies an approximation matrix method to eliminate the singular matrices and reduce its time complexity. This paper presents comparative experiments on five face databases and one handwritten digit database to validate the effectiveness of the Improved TSLDA.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.11a
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• pp.55-60
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• 2000

The effects of improved rice bran oil on the characteristics of exhaust emissions have been experimentally examined by a single cylinder, four cycle, direct injection, water-cooled and agricultural diesel engine operating at several loads and speeds. The experiments are conducted with light oil rice bran oil, and improved rice bran oil as a fuel. The fuel injection timing is fixed to 22$^{\circ}$BTDC regardless of fuel type, engine loads and speeds. To reduce the viscosity of rice bran oil, it is used with the methods of heating, methyl ester and ultrasonic system in a highly viscous rice bran oil. In this study, it is found that the brake specific fuel consumption rate of light oil is the lowest and that of improved rice bran oil is lower than that of pure rice bran oil, and NOx emissions of light oil are the lowest and those of pure rice bran oil are the highest, but soot emissions of light oil are the highest. However these results are not amply satisfied with the emissions regulation limit using the pure and improved rice bran oil as a fuel in diesel engines.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.4
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• pp.424-434
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• 2016

A few blast experiments are conducted to investigate the behavior of one-way reinforced concrete(RC) slabs under blast loading. Reflected blast characteristics as well as displacements and damage patterns of RC slabs are measured. Numerical models are also established in the software ANSYS AUTODYN to reproduce the experiments on RC slabs. The numerical models are distinguished from each other by different boundary conditions at the edges of RC slabs, which are assumed to reproduce displacements and damage patterns resulted from the experiments. The boundary condition of the experimental tests is estimated from the numerical simulation results. From the numerical simulation results, the boundary condition should be improved in order to measure the accurate maximum displacement in the experimental tests.