• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권9호
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• pp.3924-3940
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• 2020

Dynamic hand gesture recognition(d-HGR) plays an important role in human-computer interaction(HCI) system. With the growth of hand-pose estimation as well as 3D depth sensors, depth, and the hand-skeleton dataset is proposed to bring much research in depth and 3D hand skeleton approaches. However, it is still a challenging problem due to the low resolution, higher complexity, and self-occlusion. In this paper, we propose a hand-shape feature extraction(HSFE) network to produce robust hand-shapes. We build a hand-shape model, and hand-skeleton based on LSTM to exploit the temporal information from hand-shape and motion changes. Fusion between two models brings the best accuracy in dynamic hand gesture (DHG) dataset.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1670-1675
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• 2004

A thermal vapor compressor in which the subsonic/supersonic flow appears simultaneously, has been accurately designed through the CFD analysis for the various shape parameters such as the primary nozzle shape, converging duct shape. mixing tube diameter, and so on. The performance of the developed thermal vapor compressor has been experimentally verified to be installed in a Multi Effect Desalination(MED) plant as an important element, In this paper, the experimental results for Various boundary conditions(motive pressure, suction pressure, and discharge pressure) are presented in comparing with CFD results. The two results show a good agreement with each other within 3.5 % accuracy with regard to the entrainment ratio.

• 한국정밀공학회지
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• 제19권11호
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• pp.112-119
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• 2002

Generally, it is very difficult to inspect geometric shape of large 2D objects after machining. To maintain the accuracy for inspection, a robot vision is used to divide overall shape into several enlarged images, and image processing technique is applied to acquire one minute geometric contour. The inspection is to compare the NC data with the measured contour data by the vision system, and the algorithm is to rotate to minimize the maximum deviation after coinciding two geometric centers. This paper experimentally shows that the proposed algorithm is very useful for inspection of large machined objects.

• 대한음성학회지:말소리
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• 제65호
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• pp.153-168
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• 2008

We propose a new method to apply shape analysis techniques to a computational auditory scene analysis (CASA)-based speech separation system. The conventional CASA-based speech separation system extracts speech signals from a mixture of speech and noise signals. In the proposed method, we complement the missing speech signals by applying the shape analysis techniques such as labelling and distance function. In the speech separation experiment, the proposed method improves signal-to-noise ratio by 6.6 dB. When the proposed method is used as a front-end of speech recognizers, it improves recognition accuracy by 22% for the speech-shaped stationary noise condition and 7.2% for the two-talker noise condition at the target-to-masker ratio than or equal to -3 dB.

• Journal of Mechanical Science and Technology
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• 제14권11호
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• pp.1267-1275
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• 2000

A series do wind tunnel tests were conducted for Korean high-speed train model with various shape components to assess the contributions to aerodynamic drag. In order to elucidate the ground effects, two different wind tunnels, one with a moving ground system and the other with a fixed ground, were used for the same model and the results of both were compared and analyzed in detail. The result show that a suitable ground simulation is necessary for the test of a train model with many cars and detailed underbody. But the relative difference of the drag coefficients for the modifications of shape components can be measured by a fixed ground test with high accuracy and low cost. The effects of the nose shape, the inter-cargap and the bogie-fairing on total drag were discussed and some ideas were prosed to decrease the aerodynamic resistance of high speed train.

• Structural Engineering and Mechanics
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• 제35권2호
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• pp.127-140
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• 2010

This paper focuses on a number of criteria that enable controlling the influence of geometric simplification on the quality of finite element (FE) computations. To perform the mechanical simulation of a component, the corresponding geometric model typically needs to be simplified in accordance with hypotheses adopted regarding the component's mechanical behaviour. The method presented herein serves to compute an a posteriori indicator for the purpose of estimating the significance of each feature removal. This method can be used as part of an adaptive process of geometric simplification. If a shape detail removed during the shape simplification process proves to be influential on mechanical behaviour, the particular detail can then be reinserted into the simplified model, thus making it possible to readapt the initial simulation model. The fields of application for such a method are: static problems involving linear elastic behaviour, and linear thermal problems with stationary conduction.

• 소성∙가공
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• 제10권6호
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• pp.500-508
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• 2001

The integration of Rapid prototyping (RP) and Rapid Tooling (RT) has the potential for rapid net shaping of thee-dimensional parts, which have a geometrical complexity. In this study, a new R)P process, (VLM-SP), was proposed to manufacture net shapes of three-dimensional prototypes and it was shown that VLM-SP is an effective and economic process through the comparison of building time, building cost and dimensional accuracy for the test parts with the commercial RP processes ; LOM and FDM. In addition, the metal parts, which are a spanner shape and a clover punch, were produced by the plaster casting as one of RT using the prototypes of VLM-SP.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 The 8th Asian Symposium on Precision Forging ASPF
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• pp.147-151
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• 2003

In the study, the modeling strategies in connection with the quantitative prediction and improvement of product accuracy and quality are proposed. The analysis models are composed of process chain, geometry of die, interface conditions between die and workpiece, material parameters, forming velocity of machine, and so on. A 3D simulation platform, around the software MSC. Superforge, is built up for the applications in net-shape forming parts. Some results for bevel gear are shown to demonstrate the efficiency of the modeling system.

• 대한기계학회논문집
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• 제18권7호
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• pp.1643-1653
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• 1994

To facilitate the manufacturing of dull using CNC grinding machine, the simulation of helical groove machining with given wheel profile and setting condition is necessary. Considering the wheel as a collection of thin disks, the flute configuration is predicted in a cross section perpendicular to the axis and the grinding wheel profile is also predicted to machine the desired helical groove with given setting conditions. Two programs for these processes are developed. Using programs interactively, the helical groove machining process can be predicted more accurately. By clarifying the geometrical relation between the shape of cutting edge and the flute configuration in the cross section which is perpendicular to drill axis, it becomes possible to predict the necessary cross sectional shape of wheel for desired drill cutting edge shape. Some factors for the software are considered concerning prediction of accuracy and computing time.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.346-351
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• 2001

The technique of high speed machining is widely studied in machining field. Because the high efficiency and accuracy in machining can be obtained in high speed machining. Unfortunately the development of tool for high speed machining is not close behind that of machining tool. So in this study, we made 4 types flat end mill for obtaining data according to tool shape. Especially, we concentrated in helix angle and number of cutting edge. First we confirmed cutting condition by several experiments and measuring cutting force, tool life, tool wear and chip shape according to cutting length. In results, we acquired the fact that 45 degree helix angle and six cutting edge tool is suitable for high speed machining.