• Journal of Power System Engineering
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• v.14 no.3
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• pp.77-82
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• 2010

In general, the control valves are essential components in hydraulic systems. Structural changes within the valves remain a challenge because many parameters of valve tend to interact in terms of static and dynamic performance. Therefore, the valve characteristics is applied directly to the stability of hydraulic system. Inner structure of the valve which is used mainly in the industries is made up poppet type and spool type. This paper made a description of the method for numerical analysis and modeling of the valve with a built-in moving part of four-type. Based on the physical parameters of the valves, a numerical model of objected valve is developed using the bond graph method. It is to verified the results that the moving part of four-type has an effect on pressure and flow characteristics. Also, It is analyzed the results which has an effect on response characteristic by angular of poppet valve face and inertia variation of the valve with a built-in moving part. In the results, it is confirmed that the rising and settling time vary with the shape of moving part in valve.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.4
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• pp.618-632
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• 2010

This paper presents a novel approach to control the augmented reality (AR) objects robustly in a marker-less AR system by fingertip tracking and hand pattern recognition. It is known that one of the promising ways to develop a marker-less AR system is using human's body such as hand or face for replacing traditional fiducial markers. This paper introduces a real-time method to manipulate the overlaid virtual objects dynamically in a marker-less AR system using both hands with a single camera. The left bare hand is considered as a virtual marker in the marker-less AR system and the right hand is used as a hand mouse. To build the marker-less system, we utilize a skin-color model for hand shape detection and curvature-based fingertip detection from an input video image. Using the detected fingertips the camera pose are estimated to overlay virtual objects on the hand coordinate system. In order to manipulate the virtual objects rendered on the marker-less AR system dynamically, a vision-based hand control interface, which exploits the fingertip tracking for the movement of the objects and pattern matching for the hand command initiation, is developed. From the experiments, we can prove that the proposed and developed system can control the objects dynamically in a convenient fashion.

• Journal of Fashion Business
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• v.18 no.2
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• pp.14-28
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• 2014

This study analyzed the group of experts who were related to cubism, selected among the works of 2010~2013 Paris Collection based on F.G.R.(Focus Group Research). According to the results of this study, there were appeared first, 'a one-piece dress' second, 'H silhouette' third, 'cotton', in case of item distribution and frequency. The analysis was done by using the manner of expression, cubical expression, exaggeration, distortion, dismantlement, geometrical division of face, mix-match look, wraparound repetition, asymmetric structure, etc. Based on the outcomes of the analysis on figurative design elements, this study adjusted three manners appearing on cubism fashion style. First, it was 'avant garde manner' of constitution or 'dismantlement' which was compiled into multi-view representations of overlaps and viewpoints by repetitive use of color tone trimming detail. Second, it was 'geomagnetic block placement' which expresses cubism with geometric partitioning of surface and separation of panel by cutting disintegration. Finally, it was 'distortion and simplification of silhouette' which is a distortion created by constitution-line pressed thin with silhouette. It maximizes the beauty of human body outline, which was distorted by three-dimensional-manipulation, and simplified by ellipsis for another shape for the extension or expansion of detail trimming.

• Transactions of Materials Processing
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• v.16 no.4 s.94
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• pp.266-270
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• 2007

Inertia welding is a solid-state welding process in which butt welds in materials are made in bar and in ring form at the joint face, and energy required for welding is obtained from a rotating flywheel. The stored energy is converted to frictional heat at the interface under axial load. The quality of the welded joint depends on many parameters, including axial force, initial revolution speed and energy, amount of upset, working time, and residual stresses in the joint. Inertia welding was conducted to make the large rotor shaft for low speed marine diesel engine, alloy steel for shaft of 140mm. Due to material characteristics, such as, thermal conductivity and high temperature flow stress, on the two sides of the weld interface, modeling is crucial in determining the optimal weld parameters. FE simulation is performed by the commercial code DEFORM-2D. A good agreement between the predicted and actual welded shape is observed. It is expected that modeling will significantly reduce the number of experimental trials needed to determine the weld parameters.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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• pp.627-635
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• 1997

In general, the booming noise intensity at tunnel exit is strongly related to the gradient of the compression wave front created by high speed train entering the tunnel. This paper presents some results in relation with the compression wave front produced when the high speed train enters a tunnel. Four kinds of tunnel entrance shape with real dimensions were studied to investigate the formation of compression wave front inside tunnel by train entering tunnel. Computations were carried out using three-dimensional compressible Euler equation with vanishing viscosity and conductivity of fluid. According to the reslts, the flow disturbance occured at tunnel entrance were eliminated by tunnel hood with same cross sectional area. The compression wave front is formed completely at 30-40m from tunnel entrance. The maximum pressure gradient of compression wave front is reduced by 29.8% for the inclined tunnel hood and reduced by 21.5% for the tunnel hood with holes at the top face with tunnel without hood. The length of the inclined hood is 15m and the length of the hood with holes is 20m.

• Elastomers and Composites
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• v.51 no.4
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• pp.275-279
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• 2016

Additive manufacturing or 3D printing is a new manufacturing process and its application is getting growth. However, the product qualities such as mechanical strength, dimensional accuracy, and surface quality are low compared with conventional manufacturing process such as molding and machining. In this study not only mechanical characteristics of polymer sandwich panel having three dimensional core layer but also mechanical characteristics of core layer itself were analyzed. The shape of three dimensional core layer was pyramidal kagome structure. This core layer was fabricated by two different methods, injection molding with PP resin and material jetting type 3D printing with acrylic photo curable resin. The material for face sheets in the polymer sandwich panel was PP. Maximum load, stiffness, and elongation at break were examined for core layers fabricated by two different methods and also assembled polymer sandwich panels. 3D printed core showed brittle behavior, but the brittleness decreased in polymer sandwich panel containing 3D printed core. The availability of 3D printed article for the three dimensional core layer of polymer sandwich panel was verified.

• The Journal of the Korea Contents Association
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• v.14 no.9
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• pp.476-483
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• 2014

The purpose of this study was to make a suitable images for korean emotional expressions. KSFI(Korean Standard Facial Image)-AUs was produced from korean standard apperance and FACS(Facial Action coding system)-AUs. For the objectivity of KSFI, the survey was examined about emotion recognition rate and contribution of emotion recognition in facial elements from six-basic emotional expression images(sadness, happiness, disgust, fear, anger and surprise). As a result of the experiment, the images of happiness, surprise, sadness and anger which had shown higher accuracy. Also, emotional recognition rate was mainly decided by the facial element of eyes and a mouth. Through the result of this study, KSFI contents which could be combined AU images was proposed. In this future, KSFI would be helpful contents to improve emotion recognition rate.

• Archives of Craniofacial Surgery
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• v.15 no.3
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• pp.129-132
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• 2014

Facial skeletal remodeling was revolutionized more than 30 years ago, by the work of Tessier and other craniofacial surgeons. However, the need to correct the skeleton in the upper third of the face is not frequently diagnosed or treated in aesthetic facial surgery. Here, we report on the aesthetic correction of a protrusive forehead. A patient visited our hospital for aesthetic contouring with a prominent forehead. The anterior wall of the frontal sinus was removed with a craniotome via the bicoronal approach. After the excised bone was repositioned, it was fixed with a titanium mesh plate and screws. An electric burr was used to contour the supraorbital rim and frontal bone. Once the desired shape was achieved, the periosteum was replaced, and the wound was closed in layers. When performed properly, frontal sinus contouring could significantly improve the appearance in patients with a prominent forehead. Plastic surgeons must carefully evaluate patients with a prominent forehead for skeletal remodeling that involves the accurate and safe repositioning of the anterior wall of the frontal sinus.

• The Journal of the Korean dental association
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• v.58 no.8
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• pp.505-512
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• 2020

With the fourth industrial revolution, digitization is accelerating in all healthcare areas. In the field of dentistry, active discussions on digital dental technologies are ongoing, with increasing interest from clinicians daily. Thus far, accuracy and efficiency have primarily been emphasized in digital dentistry, and interest in occlusion has been relatively low. This is because digital dentistry has been predominantly used to restore small numbers of teeth rather than extensive prosthetic reconstruction. However, in the future, most dental treatments will undergo a digital transformation that will require the application of digital technology to more extensive prosthetic rehabilitation, for which discussion of occlusion is essential. In extensive prosthetic reconstruction, occlusion and articulation involve determining the position of the dental arch in relation to the reference plane of the skull or the long axis of the face and the position of the transverse horizontal axis. It also includes determining an occlusal surface with a shape that allows the mandible to move in an eccentric path and masticate most efficiently without any occlusal interference. To better understand how digitization will impact dentistry, this review article summarizes and discusses occlusion and articulation using digital dental technologies. This discussion is divided into several aspects, including facial scan, virtual articulation, augmented reality, and virtual reality.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.5
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• pp.631-637
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• 2010

In this paper, We propose a method of motion interpretation of pedestrian for active traffic signal control. We detect pedestrian object in a movie of crosswalk area by using the code book method and acquire contour information. To do this stage fast, we use parallel processing based on CUDA (Compute Unified Device Architecture). And we remove shadow which causes shape distortion of objects. Shadow removed object is judged by using the hilbert scan distance whether to human or noise. If the objects are judged as a human, we analyze pedestrian objects' motion, face area feature, waiting time to decide that they have intetion to across a crosswalk for pdestrians. Traffic signal can be controlled after judgement.