• Journal of Welding and Joining
• /
• v.31 no.3
• /
• pp.22-30
• /
• 2013

Due to ELV banning, automotive electronics cannot use four kinds of heavy metal element (Pb, Hg, Cd, $Cr^{6+}$) from 2016. Therefore, this study was focused on degradation characteristics of Sn-3.0Ag-0.5Cu Lead-free solder joint with OSP and ENIG finsh under various reliability assessment method, as like to thermal shock test and high temeprature/high humidity test with test duration for cabin electronics. Also, we compared bonding strength degradation to other advanced research results of electronic control unit for engine room because of difference service temperature with mount location in automotive. Whisker growth phenomenon and mitigation method which were essentially consideration items for Pb-free car electronics were examined. Conformal coating is a strong candidate for mitigating whisker growth in automotive electronics. Necessary condition to adapt Pb-free in car electronics was shown.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.7 no.1
• /
• pp.251-258
• /
• 2003

This study is to understand the characteristics of axial force behavior that operates to the part of continuous welded rail and to investigate the basic data for secure the structure's stability and retrofit of the track. To develop the FEM model that type of plate girder which is used in the domestic national railway among servicing railway type. It is to analyze the characteristics of axial force behavior according to equip of the expansion joint and support placing by using the axial force simulation in making the continuous welded rail. As the result of research on the parametric valuables through the analysis, it is investigated that 'FMFM type' is more efficient than the other support type. Also, it conclude that structures are having the expansion joint is the most safe condition.

• The Journal of Korea Robotics Society
• /
• v.6 no.3
• /
• pp.284-291
• /
• 2011

This paper presents the estimation of the frictional coefficient of the wheel-legged robot with hip joint actuation producing maximum tractive force. Slip behavior for wheel-legged robot is analytically explored and physically understood by identification of the non-slip condition and derivation of the torque limits satisfying it. Utilizing results of the analysis of slip behavior, the frictional coefficients of the wheel-legged robot during stance phase are numerically estimated and finally this paper suggests the pseudo-algorithm which can not only estimate the frictional coefficients of the wheel-legged robot, but also produce the candidate of the touch down angle for the next stance.

• Proceedings of the KSR Conference
• /
• 2004.10a
• /
• pp.793-799
• /
• 2004

In track a third weakness point is joint part, turnout part, curve part. One of them joint part of rail have been known to the most weak point by loosen of joint bar and fish bolt due to impulse and vibration by wheel contact at times. In addition happen to deformation and failure at end of rail, failure and miniature of ballast gravel. Finally impact between wheel and rail become origin cause of a welded rail, noise and vibration. riding condition deterioration, besides track failure. In the present domestic, Thermite and Gas pressure weldings have been used to continuous welded rail(CWR), however stiffness and confidence in quality is lower than Flash butt welding method. FRW have the excellent capacity, however have a shortcoming large scale of machine and power equipment. Therefore we will introduce Mobile Flash Butt Welder can weld in track.

• Journal of Oral Medicine and Pain
• /
• v.43 no.2
• /
• pp.56-60
• /
• 2018

Epidermoid cyst in bony wall of external auditory canal (EAC) is a very rare pathologic condition. In addition to its extreme rarity, its positional proximity to temporomandibular joint (TMJ) might lead to clinical misdiagnosis as TMJ disorders, especially when it is accompanied by temporomandibular disorders-like symptoms. In this article, we report a patient with epidermoid cyst in anterior bony wall of EAC, which was misdiagnosed as TMJ disorder because the left TMJ pain aggravated during mastication.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2009.09a
• /
• pp.441-448
• /
• 2009

In this study, the joint part of non-welding composite pile is investigated by a three dimensional finite element analysis. Special attention is given to the overall stress distribution under lateral, axial and tensional load conditions. Through comparisons with allowable stress of materials, a simple method is proposed to estimate the ultimate load condition of joint part. The appropriate design method is suggested and highlighted through the numerical analysis.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.16 no.2
• /
• pp.215-220
• /
• 1994

In the case of the trauma on the maxillofacial region occurred, we think that one of the most important thing is recovery of the function as well as reconstruction of the anatomical form. Especially, it has been that the structure of the surrounded temporomandibular joint has a great possibility to cause mouth opening limitation when a bit of displacement is caused. Therefore, in the case of the trauma on mid-face we think that we treat it after complete evaluate condition of soft and hard tissue surrounding the articular disc as well as fracture site. We report results of our study, since we obtained good results from our study concerning the refixation of the zygomatic arch, high condylectomy, coronoidectomy and myotomy for the patient being suffered from the arthrosis of the temporomandibular joint caused by insufficient fracture treatment of zygomatic arch and coronoid process.

• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 2005.11a
• /
• pp.129-132
• /
• 2005

Recently, Domestic construction industry is confronted with a new phase by increasement of stock and elation of the concern about environment. In particular, the focus on remodeling as an altanative of the reconstruction system that squanders resources and creates massive construction waste, has increased. However, current remodeling methods are being obstructed factor, because design has not considered the remodeling at the beginning of the construction. The purpose of this study is to search for the improvement of component joint for efficient remodeling. Field survey is conducted on the components grouped by spaces(living room/bed room/kitchen/bathroom) of unit living at 6 construction sites in Seoul & countries. As a result, total 228 component joints are selected and classified according to interface condition and problem pattern.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.11a
• /
• pp.219-220
• /
• 2017

Current domestic waterproofing market in Korea mainly uses single-ply waterproofing materials comprised of coatings or waterproof sheets and two or more-ply composite waterproofing methods. In order to evaluate these types of composite waterproofing systems, a new test equipment and method that incorporates various deterioration conditions (joint displacement, chemical exposure, water pressure etc) was developed. In a comparison testing, the results showed that flexible type materials have higher response performance towards joint displacement than the hardened material. Furthermore, the importance of securing the stability of the waterproofing method in the vulnerable over-lap joint areas of waterproofing sheets is emphasized.

• Korean Journal of Applied Biomechanics
• /
• v.17 no.3
• /
• pp.225-232
• /
• 2007

This work intends to investigate the effects of shift characteristics on the propulsion performance of a manual wheelchair with an automatic transmission. A planetary gear train is employed to generate a two-stage shift automatically, based on the distance traveled from rest. Motion analysis has been performed for measuring kinematic properties of the arm and then the inverse dynamics has been applied for estimating joint forces/torques. Then, a parametric study has been performed to find a set of the shift ratios and the shift intervals for optimizing propulsion performance. Results show that the propulsion performance is closely related to the shift condition. It is found that a short shift interval is desirable for a short distance propulsion. However, an optimum shift interval for a long distance propulsion is inversely proportional to the shift ratio approximately. Consequently, the automatic transmission can greatly lower the joint loadings by the speed reduction, which eventually contribute to prevent joint injuries of wheelchair users.