• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.12
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• pp.2503-2510
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• 2002

Since the first shape-form-shading technique was developed by Horn in the early 1970s, many different approaches have been continuously emerging in the past three decades. Some of them improve existing techniques, while others are completely new approaches. Using the image reflectance equation, they estimate the 3-D shape of an object utilizing adequate constraints. Each algorithm applies different constraints such as brightness, smoothness, and integrability to solve the shape-from-shading problem. Especially for symmetric objects, a symmetry constraint is proposed to improve the performance of existing shape-from-shading algorithm in this paper. The symmetry constraint is imposed to a conventional algorithm and then the improvement in the performance of 3-D shape reconstruction is proved by quantitatively comparing the depth and gradient errors.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1310-1315
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• 2003

Severe osteoarthrosis of the knee joint often requires total knee arthroplasty (TKA) to yield adequate knee function. The knee joint with TKA is expected ideally to restore the characteristics, however, this is not necessarily true in the clinical cases. In this study the motions of the intact joint and the joint after TKA were investigated numerically using computer simulation. For active knee extension from 90 degrees of flexion to full extension, the intact knee joint exhibited anterior tibial translation near the full extension while it showed only rotation for other flexion angles. Physiologic external rotation of the tibia near full extension was also noted in the analytical model. The analysis of the tibial insert of three different shapes (flat, semicurved, and curved types) demonstrated characteristic rotational and sliding motions as well as different contact forces.

• Smart Structures and Systems
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• v.11 no.2
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• pp.135-161
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• 2013

This work presents a test platform for the assessment and benchmarking of modern actuators which have been specifically developed for the new field and service robotics applications. This versatile platform has been designed for the comparative analysis of actuators of dissimilar technology and operating conditions. It combines a modular design to adapt to linear and rotational actuators of different sizes, shapes and functions, as well as those with different load capacities, power and displacement. This test platform emulates the kinematics of robotic joints while an adaptive antagonist-load actuator allows reproducing the variable dynamic loads that actuators used in real robotics applications will be subjected to. A data acquisition system is used for monitoring and analyzing test actuator performance. The test platform combines hardware and software in the loop to allow actuator performance characterization. The use of the proposed test platform is demonstrated through the characterization and benchmarking of three controllable impedance actuators recently being incorporated into modern robotics.

• International Journal of CAD/CAM
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• v.3 no.1_2
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• pp.1-12
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• 2003

When milling concave corners, cutter load increases momentarily and fluctuates severely due to concentration and uneven distribution of material stock. This abrupt change of cutter load produces undesirable machining results such as wavy machined surface and cutter breakage. An important factor for studying cutter load in 2.5D pocket milling is the instantaneous Radial Depth of Cut (RDC). However, previous work on RDC under different corner-cutting conditions is lacking. In this different corner shapes. In our work, we express RDC mathematically in terms of the instantaneous cutter engage angle which is defined as Cutter Swept Angle (CSA). An analytical approach for modeling CSA is explained. Finally, examples are shown to demonstrate that the proposed CSA modeling method can give an accurate prediction of cutter load pattern at cornering cut.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.376-380
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• 2009

The transmission noise characteristics through the ventilating duct was conducted numerically using SYSNOISE. A ventilating system is usually composed of mufflers for preventing noise transmission from the ventilator into indoors through the ducts and distributors for transferring air to or from each room. The transmitted noise characteristics of distributors which have different branch angles and of mufflers having different shapes were analyzed numerically. New duct element combining a muffler and a T-shaped distributor was developed for better noise reduction in this paper. New element's performance was shown numerically.

• Korean Journal of Pharmacognosy
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• v.26 no.4
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• pp.411-418
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• 1995

In order to clarify the originality of several Alisma Rhizomes, we investigated the differences of their morphological, anatomical and physiochemical characteristics. Morphological observation shows the variability of Alisma shape and quality. The diversities in morphological shapes and qualities of tuber were observed among different origins. Chinese product looked like corm shape, but korean's irregular shape. The microscopic observation of korean Alisma revealed the presence of irregular vascular bundle which was scattered transversely and longitudinaly, which was different from that of the rhizome. This facts suggest that the portion of crude drug in Alisma should be the corm rather than the rhizome. In the physicochemical differences, chinese Alisma contains larger amount of mineral elements such as K, Na and Ca than korean Alisma. On the contrary, protein contents in lyophilized powder of aqueous extracts in korean Alisma rhizome was significantly higher than chinese Alisma rhizome. The leaves and stems contained larger amount of Ca and Na than tuber, and may be used as the osmotic diuretics for chinese traditional medicine.

• Computers and Concrete
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• v.12 no.1
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• pp.79-90
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• 2013

In this study, dynamic characteristics such as natural frequencies, mode shapes and damping ratios of RC frame is determined for different construction stages using Operational Modal Analyses method under ambient vibration. Full scaled, one bay and one story RC frames are selected as an application for different construction stages such as plane, brick in-filled and brick in-filled with plaster. The RC frame is vibrated by natural excitations with small impact effects and the response signals are measured using sensitive accelerometers during ambient vibration tests. Measurement time-frequency span and effective mode number are determined by considering similar studies in literature. Sensitive seismic accelerometers are used to collect signals obtained from the experimental tests. To obtain experimental dynamic characteristics, output-only system identification technique is employed namely; Enhanced Frequency Domain Decomposition technique in the frequency domain. It is demonstrated that the ambient vibration measurements are enough to identify the most significant modes of RC frames.

• Structural Engineering and Mechanics
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• v.60 no.4
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• pp.729-747
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• 2016

This study aims to present a novel optimization algorithm known as gravitational search algorithm (GSA) for structural damage detection. An objective function for damage detection is established based on structural vibration data in frequency domain, i.e., natural frequencies and mode shapes. The feasibility and efficiency of the GSA are testified on three different structures, i.e., a beam, a truss and a plate. Results show that the proposed strategy is efficient for determining the locations and the extents of structural damages using the first several modal data of the structure. Multiple damages cases in different types of structures are studied and good identification results can be obtained. The effect of measurement noise on the identification results is investigated.

• Journal of the Korean Society of Costume
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• v.53 no.8
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• pp.1-10
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• 2003

The purpose of this study was to verify fitness of a new raglan sleeve pattern according to the result of appearance and function evaluation. Also, it was to search the relation between the construction factor and the function on the selected 3 types of the existent raglan sleeve patterns and the new sleeve pattern. Three female university students having different shoulder shapes were selected as subjects, wore 4 different types of the raglan steeve was evaluated by professional panel. The functions of the evaluated sleeve patterns evaluated was made by the wearer themselves. According to the comparison of the new raglan sleeve pattern with the existent raglan sleeve pattern, the new raglan sleeve pattern acquired the higher evaluation scores both on the appearance test and the function evaluation. It was known that the appearance and function of the raglan sleeve pattern were effected by construction factors of the sleeve pattern.

• Journal of Korean Medical classics
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• v.26 no.1
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• pp.47-54
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• 2013

Objective : Each terminology has twofold meaning. Chinese character has several meanings because it is phonogram. Even if exactly same in shapes but the meaning is different. We should be more careful about meaning of the character Fu(胕) in Huangdineijing. Method : We try to find out the meaning of fu excluding meaning of fu(胕), edema(胕腫) in Huangdineijing. Result : Fu means fermented food, edema, sticking, skin, top side of the foot and so on. Conclusion : Someone who have concern traditional medical classics have to give attentions that characters in classics could get different meanings in same character.