• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.15 no.6
• /
• pp.121-126
• /
• 2006

Snap-fit is being used in manufacture of plastic products. Integral features using snap-fit are classified as locks, locators and enhancements. Locking features complete the process of attachment by providing physical interference to prevent separation. Looking feature pairs consist of two components, i.e., a flexible latch and a rigid catch and require particular care and attention for their selection. We can make several locking feature pairs by selecting latch and catch, but some parts restrict freedom of selection. Therefore, part designers must know the characteristic properties of generic locking feature forms as considering a specific design problem. In this paper, it has been presented about problem of small size products using locking feature and then introduced new locking feature applicable to small parts.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.9
• /
• pp.1175-1182
• /
• 2013

The lock-in mode infrared thermography (IRT) technique has been developed to improve the detection capability of defects in materials with high thermal conductivity, and it has been shown to provide better detection capability than conventional active IRT. Therefore, to investigate the application of this technique to nuclear piping components, lock-in mode IRT tests were conducted on pipe specimens containing simulated wall-thinning defects. Phase images of the wall-thinning defects were obtained from the tests, and they were compared with thermal images obtained from conventional active IRT tests. It showed that the ability to size the detected wall-thinning defects in piping components was improved by using lock-in mode IRT. The improvement was especially apparent when detecting short and narrow defects and defects with slanted edges. However, the detection capability for shallow wall-thinning defects did not improve much when using lock-in mode IRT.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.10
• /
• pp.648-654
• /
• 2018

In order to maintain manholes installed on the road, the manhole should be easy to open and close. Manhole covers under harsh conditions require that they can be lifted when attempting to open the manhole because the frame and cover are stuck and difficult to open and close. In this study, the design of a lifting mechanism was carried out to improve and integrate the locking type manhole. The mechanism of the locking manhole is that when the bolt located at the center is turned, the hub connected with the bolt descends, and the hook connected to the hub is rotated. The end of the hook is hooked to the manhole frame. The auxiliary device was installed on the hook so that the manhole cover can be lifted. The structure was designed to endure about 300kg of lifting force based on 70% of the yield stress of the hook to perform lifting function. The shape design was performed through the structural analysis using the finite element method. First, the basic design was performed with the simplified 2-dimensional model and the attachment position and shape were designed through the 3-dimensional model. In order to find out the structural problems of the designed shape, the scale downed model was fabricated through 3D printing and confirmed that the lifting function worked. Finally, it was confirmed that both the locking and the average lifting of about 6.1 mm can be done by applying the lifting mechanism through the machining and applying it to the existing locking manhole.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.36 no.6
• /
• pp.699-705
• /
• 2012

The role of a seat belt in a vehicle is to protect the driver from injury when a crash occurs. However when a large crash occurs, the driver slips forward and receives a strong impact. To prevent this situation, improvement of seat belts is essential. In this study, the new concept of a dynamic locking tongue (DLT) for seat belts is developed. The DLT device is used to reduce the impact to the driver's chest by tightening the webbing, so the driver is protected from severe injury in a large crash. First, a finite element model of the DLT device is created using SAMCEF and structural analysis is conducted with boundary conditions similar to those found in experiments. Then, the stress in the DLT device can be calculated. Second, the shape of the DLT device is optimized using the response surface analysis method in order to minimize the stress and weight. The validity of the optimization of the DLT device is verified using structural analysis.

• Journal of Biomedical Engineering Research
• /
• v.23 no.5
• /
• pp.385-390
• /
• 2002

Nowadays, there are many attempts to develop domestic medical-equipments. In this study, it is performed to developed a new vertebral fusion device. The basic models are a rectangular-frame type and a screw type which are generally used for the patients. The main purpose of the development of a new device is to reduce the amount of bone taken out for the insertion of a device to vertebral disc and this paper is focused on th concept of a new device shape. In the results, two types are devised. One is a folding type and the other is a separate-push-in type device both are in primitive stage. However, in a folding type there are mechanical pins and the analysis of pins and the lock system is still in study and needs some time. Therefore a separate-push-in type is introduced in this study mainly and a prototype and 3-D finite element model are made and experimented and stress analyzed. From the results it is considered that it is stable for the basic loading condition of vertebra, however, it is required to develop a supporting operational equipment for the convenience of the operation in practice.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.37 no.4
• /
• pp.323-329
• /
• 2013

This study attempts to simulate the structure of a woody leaf netted venation system by using topology optimization techniques. Based on finite element method (FEM) analysis of an incompressible fluid, a topology optimal design is applied to those woody leaf netted venation models. To solve the transverse shear locking problem of a thin plate caused by the Mindlin-Reissner plate model where a leaf netted venation is assumed to be a thin plate, a P1-nonconforming element and selective reduced integration are employed. Topology optimal design is applied to multiple physical domains. Combined with the Darcy-Stokes flow problems and extended to the optimal design of fluid channels, the multiple physical models of the flow system are analyzed and venation patterns of leafs are simulated. The calculated optimal shapes are compared with the natural shapes of woody leaf venation patterns. This interdisciplinary approach may improve our understanding of the leaf venation system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.10a
• /
• pp.1015-1017
• /
• 2013

Object tracking, in general, is a challenging problem. Difficulties in tracking objects can arise due to abrupt object motion, changing appearance patterns of both the object and the scene, non-rigid object structures, object-to-object and object-to-scene occlusions, and camera motion. Tracking is usually performed in the context of higher-level applications that require the location or the shape of the object in every frame. This paper describes an object tracking system based on active vision with two cameras, into algorithm of single camera tracking system an object active visual tracking and object locked system based on Extend Kalman Filter (EKF) is introduced, by analyzing data from which the next running state of the object can be figured out and after the tracking is performed at each of the cameras, the individual tracks are to be fused (combined) to obtain the final system object track.