• Transactions of the Korean Society of Automotive Engineers
• /
• v.13 no.5
• /
• pp.42-49
• /
• 2005

In general, multi-lap spot weld joints are frequently present in automobile. Most research, however, has been focused on the single-lap spot weld joints until now. In this paper, tensile-shear strength tests are performed to examine the weldability of 3-lap spot joint welded by using the high strength steel sheet and the zinc coated steel sheet. The indentation depth and nugget diameter are used to propose the optimum welding conditions. The weldability is affected by the welding current and welding time for 3-lap spot joint. Meanwhile the expulsions is round to decrease with the increase of electrode force. The optimum welding conditions are presented for 3-lap spot joints of high strength steel sheet and zinc coated steel sheet.

• Journal of the Korean Geotechnical Society
• /
• v.16 no.6
• /
• pp.35-41
• /
• 2000

Residual stress is defined as a minimum stress with a large displacement of specimens and the residual stress after peak shear stress appears with displacement volume but there is no provision to select the residual stress. In the previous study, residual stress was recorded when the change of shear load is small in the condition of the strain more than 15%. But, in this study, hyperbolic function((No Abstract.see full/text), b=experimental constant) of soil test is adapted to joint of rock and the propriety is investigated. In a landslide and landsliding of artificial slope, wedge failure of tunnel with a large displacement, tests are simulated from peak stress to residual stress for safety analysis. But now. direct shear stress and triaxial compressive tests are usually performed to find out characteristics of shear stress about joint. Although these tests get a small displacement, that data of peak stress and residual stress are used for safety analysis. In this study, we tried to determine failure criteria for joints of rock using ring shear test machine. The residual stress following shear behavior was determined by the result of ring shear test and direct shear test. In conclusion, after comparing the results of the two test, we found that cohesion(c) and internal friction angle(ø) of ring shear test are 30% and 22% respectively of those of the direct shear test.

• Journal of Welding and Joining
• /
• v.17 no.6
• /
• pp.53-61
• /
• 1999

The use of thick plate in increasing in recent years due to the rapid expansion of chemical plants, nuclear plants, ships and other industrial plants. Welding is the most popular joining techniques employed in manufacturing industrial machineries and structures. Normally, Groove shapes are prepared according to appropriate rules and regulations such as KS, JIS, AWS, LR, DNV and etc. for various thicknesses of plate. However those groove angles tend to be too large. As a result of large groove angle, residual stress, deformation of material and strength reduction is obtained. Therefore, the reliability and safety of structures and machinery tend to be decreasing. Therefore, in this paper, theoretical as well as experimental study are carried out to find optimum groove shapes for T-welded joint of mild steel. The test specimen are made in same condition with simulation model. Welding residual stresses measurement by sectional cutting method. ⅰ) The mechanical difference for change the thickness of plate and groove angle are not appeared. ⅱ) In a mechanical point of view minimum preparation angle(40°) is more suitable than maximum groove angle(60℃). ⅲ) The measurement value and distribution of welding residual stresses are not effected largely by groove angle. It is mechanical restraint that mainly affect welding residual stresses distribution. In mechanical point of view minimum groove angle is more suitable than maximum groove angle. Therefore, it is appropriate to minimize the size of groove shape in strength and safety.

• Journal of Veterinary Clinics
• /
• v.22 no.3
• /
• pp.249-252
• /
• 2005

This study was carried out to assess hip joint in Labrador retrievers. From 1999 to 2004, 131 Labrador retrievers were tested by British Veterinary Association(BVA)/Kennel club(KC) scoring scheme, 66 were tested by $PennHIP^{(R)}$ method. In this study the mean score by BVA/KC scoring scheme was $12.5{\pm}6.6$ and the mean DI was $0.53{\pm}0.14$. It was found that Labrador retrievers of Samsung Guide Dog school have better hip joint condition than that of Labrador retrievers registered in BVA, and have similar mean DI to PennHIP breed mean score. This study suggested that using both BVA/KC scoring scheme and $PennHIP^{(R)}$ method was a specific method which can make the most possible definitive diagnosis, could provide baseline hip information for the hip joint in Labrador retrievers as Guide Dog.

• Korean Journal of Child Studies
• /
• v.33 no.3
• /
• pp.199-213
• /
• 2012

This study was conducted in order to identify the relationship between the home literacy activities, mothers' verbal behavior, toddler-mother joint attention and the language-cognitive development of toddlers. The language-cognitive development of toddlers was assessed by means of the Mental Scale from the Korean Bayley Scale of Infant Development II (K-BSID-II). The home literacy activities were measured by means of the questionnaire used by You (2009), which was partly modified from Shapiro (1979). Lee & Kim (2004)'s categories was used to observe the mothers' verbal behaviors during shared book reading; joint attention episodes were observed by classification categories for engagement condition (Bakeman & Adamson, 1984). One of the more important conclusions of this study is our suggestion that mothers' verbal behaviors and the toddler-mother coordinated joint attention were significantly related to the language-cognitive development of toddlers as it takes place within low-income families.

• Journal of The Korean Dental Society of Anesthesiology
• /
• v.13 no.3
• /
• pp.121-126
• /
• 2013

Temporomandibular joint (TMJ) dislocation is an acute paintful condition that causes severe functional limitation. So, manual reduction is the treatment of choice and should be performed as early as possible. Long-term dislocation of the TMJ that has persisted for more than 1 month is comparatively rare. This may include severe illness, neurological diseases and prolonged intensive care hospitalization with oral intubation and sedation. A joint that remains prolonged dislocated undergoes morphological change which is also true for periarticular tissue, especially in ligaments and muscles. Treatment of long-term TMJ dislocation should be different from acute TMJ dislocation, as simple reduction is difficult to achieve and it's likely to redislocate. The prevention of redislocation after reduction should be considered. This is a case report of about manual reduction of temporomandibular joint long-standing dislocation under general anesthesia.

• Journal of Ocean Engineering and Technology
• /
• v.22 no.3
• /
• pp.96-102
• /
• 2008

As LNG tank is operated around $-162^{\circ}C$, an experimental approach on the cryogenic temperature tensile and fatigue strengths of SUS304L lap joint weld is very important at the design stage of membrane type LNG tank. In this study, in order to estimate the tensile and fatigue strengths of SUS304L lap joint weld at cryogenic temperature condition, tensile and fatigue tests were conducted. Also, S-N curves are presented with statistical testing method recommended by JSME. As a result of the experimental approach, the d￡sign guide of fatigue strength is proposed and that is expected to be useful for membrane type LNG tank design.

• The Journal of Korea Assosiation for Disability and Oral Health
• /
• v.11 no.2
• /
• pp.62-66
• /
• 2015

Temporomandibular joint dislocation causes considerable pain, discomfort, and swelling. The anatomic construction of the articular fossa and the eminentia articularis may predispose to dislocation, and weakness of the connective tissue forming the capsule is believed to be a predisposing factor. The capsule may be stretched and, more rarely, torn. Dislocation may be unilateral or bilateral and may occur spontaneously after stretching of the mouth to its extreme open position, such as during a yawn or during a routine dental operation. Manual reduction with the patient under muscle-relaxing condition or anesthesia is recommended method. After the reduction of an acute dislocation, immobilization of the jaw is recommended to allow the stretched and sometimes torn capsule to heal, thus preventing recurrence. A Barton's bandage may be applied for 2 to 3 weeks to prevent the patient from opening the jaw too wide. But, it results in recurrent dislocation in the neurologically disabled patient, because of loose intermaxillary fixation. This is a case report about management of recurrent temporomandibular joint dislocation by multiple loop wirings and intermaxillary elastics in cerebrovascular accident patient.

• Tunnel and Underground Space
• /
• v.17 no.2 s.67
• /
• pp.102-108
• /
• 2007

Generally, the method used most widely for rock mass classification is considering the rock strength and development of joint frequency. However, if rock bed has micro-crack and long joint, this method is not rational. Therefore, the difficulties of excavation in the rock bed with complicated geological condition are decided by combining joint frequency. indoor tests (uniaxiall compressive strength, point load test, indoor elastic wave velocity, etc.) and field seismic refraction survey, and the rock mass classification should be implemented by considering their interrelationship.

• Korean Journal of Applied Biomechanics
• /
• v.29 no.2
• /
• pp.89-96
• /
• 2019

Objective: The purpose of this study was to investigate biomechanical comparisons of kettlebell two-arm swings after different somatosensory interventions on joint ranges of motion (ROM) and muscle activations. Method: Fourteen kettelbell novices (age: $22.92{\pm}3.23yrs$, mass: $75.75{\pm}9.94kg$, height: $172.03{\pm}5.49cm$), consisting of male college students, participated in this study and performed two-arm kettlebell swings in different conditions. Three different somatosensory interventions were the applications of heavy mass kettlebell (20 kg), taping on gluteus muscles, and unstable mat condition. All subjects performed pre-intervention swings and post-intervention swings, respectively. Statistical analysis were performed on results of joint kinematics and electromyographies of major muscles. Results: Results showed significant increases in ROM of hip and decreases in ROM of shoulder after unstable mat trials. In addition, the application of unstable mat during kettlebell swings induced higher muscle activations in gluteus maximus muscle during only upward phase of two-arm kettlebell swings. Conclusion: For beginner, the application of unstable surface would increase in hip joint ranges of motion with enhancement of gluteus muscles.