• Journal of the Korean Society of Physical Medicine
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• v.2 no.2
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• pp.243-250
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• 2007

Purpose : Shoulder subluxation is a very common problem in patients with hemiplegia with stroke. Prevention of the low tone subluxed shoulder has been an issue for physical therapists working with neurological patients for many years. Methods : This study reviewed the literature to definite the management and a cause of shoulder subluxation with hemiplegia patients after stroke. Various modalities have been suggested for realigning the glenohumeral joint, but their use is controversial. The purpose of this paper is to review critically the evidence base in order to inform the clinical decision-making process for physiotherapists working in neurology. Results : Literature has identified supports, strapping and functional electrical stimulation(FES) in the management of low tone shoulders. Following review of this evidence it is suggested that there is a lack of reliable and valid research evidence on which to base conclusions. The modalities with the best supporting evidence for realigning the low tone subluxed glenohumeral joint are the triangular sling, Harris hemi sling and the Rolyan humeral cuff used in a standing position and the lap board and arm trough while the patient is sitting. However, due to soft tissue adaptation with associated lack of movement, over-correction and the need for careful patient positioning these supports need to be evaluated for each patient and should be used only in appropriate situations. Conclusion : Similarly, there is a lack of evidence on the effects of long-term use to this equipment. Electrical stimulation is also thought to have potential in the treatment to subluxed low tone shoulders but additional research is required to clarify the parameters for use and the long-term effects of these forms of management.

• Elastomers and Composites
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• v.33 no.4
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• pp.267-273
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• 1998

Isocyante terminated urethane prepolymers were synthesized by the reaction of 4,4'-dimethyl phenyldiisocyanate(MDI) and ester type polyols such as ethylene glycol/ butanediol adipate(EBA), neopentylglycol/butanediol adipate (NBA) and hexanediol adipate (HA) . All of the NCO-terminated urethane prepolymers are solid at room temperature, but they become mobile enough to be disposed onto a substrate upon heating about $80^{\circ}C$. Subsequently, they are solidified and cured through the reaction with moisture. Tensile behavior of the ore-thane hotmelt exhibits characteristic features depending on the type of polyol. The adhesive strength determined by single lap shear joint is higher in order of HA, NBA and EBA based ore thane hotmelt, which can be correlated with the magnitude of breaking energy of the cured films. The failure mode are cohesive for all cases and the adhesive strength increases as the test is performed faster. This indicates that the strength of the adhesive joint is primarily dependent upon the bulk properties of the adhesives.

• Journal of Welding and Joining
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• v.26 no.1
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• pp.69-75
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• 2008

Spot welding which use the main process for side block production of stainless steel railway vehicle is legged behind in laser welding about a quality and productivity. Although the laser welding has many potential advantages such as low heat input and aspect ratio of weld bead, its application to a new structural component still is required many engineering data including mechanical properties such as tensile, fatigue strength, etc on. Therefore, experimental analysis was carried out to understand the fatigue phenomena of different thickness stainless steel overlap joining panels by Nd:YAG laser welding. The fatigue life curves were obtained through fatigue tests with the various levels of applied load. The fatigue life is related with the parameters such as gap size and penetration depth through experiment. As the results, tensile strength and fatigue life were proportional in heat input level and gap was identified the major factor for fatigue life. Also we could know that deferent a-ferrite content at HAZ depend on welding heat input was important factor to determine a formation of initial crack and total fatigue life cycle.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.1
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• pp.148-159
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• 1998

Spot welding palys a key role in increasing productivity and weight reduction of the final products. This paper proposes a systematic approach on the design of spot weld configuration, dealing with the requried number and location of spot weld joints under the given design parameters, such as the applied loads, lap area, and individual spot weld strength. The optimal design of a spot-welded joint is postulated as a state when the safety factors of all spot weld points (i) are evenly distributed and (ii) reach maximum value. A CAD program is developed to arrange the optimal location of each spot weld based on the derived objective function and constraints. The CAD tool integrates the optimization procedure with Finite Element Analysis (FEA) code through an interface. The interface automatically provides geometrical data and mesh configuration for different spot weld locations to FEA model. It also extracts the transmitted load of each spot weld from the FEA code, and allows the optimization code predict an improved arrangement of spot weld locations. The feasibility of the developed approach is demonstrated by the selected examples.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.04a
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• pp.149-153
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• 2000

Substituting composite structures for conventional metallic structures has many advantages because of higher specific stiffness and specific strength of composite materials. In this work, one-piece propeller shafts composed of carbonfepoxy and glass/epoxy composites were designed and manufactured for a rear wheel drive automobile satisfying three design specifications, such as static torque transmission capability, torsional buckling and the fundamental natural bending frequency. Single lap adhesively bonded joint was employed to join the composite shaft and the aluminum yoke. For the optimal adhesive joining of the composite propeller shaft to the aluminum yoke, the torque transmission capability of the adhesively bonded composite shaft was calculated with respect to bonding length and yoke thickness by finite element method and compared with the experimental result. Then an optimal design method was proposed based on the failure model which incorporated the nonlinear mechanical behavior of aluminum yoke and epoxy adhesive. From the experiments and FEM analyses, it was found that the static torque transmission capability of composite propeller shaft was maximum at the critical yoke thickness, and it saturated beyond the critical length. Also, it was found that the one-piece composite propeller shaft had 40% weight saving effect compared with a two-piece steel propeller shaft.

• Laser Solutions
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• v.17 no.3
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• pp.1-9
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• 2014

In this study, we analyzed fiber laser welding for the pure copper thin plates in a series of secondary lithium-ion batteries; and performed the experiment for the purpose of the preceding study to replace bolt joints method the with the laser welding method. We have changed the peak power of the laser from 5 to 6kW, the pulse duration by 4, 6, 8, and 10ms, the frequency by 10, 12, 16, and 25Hz, and the focal position by -3, 0, and +3. As a result, when the focal position is at +3, the peak power is 5kW, and the pulse duration and the Frequency are 4ms and 25Hz, respectively, we obtain 2.1 and 2.5 times better tensional strengths, respectively, than the highest values of tensional strengths obtained with the focal positions at 0 and -3.

• Advances in aircraft and spacecraft science
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• v.1 no.1
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• pp.1-14
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• 2014

Physico-chemical changes of the plasma modified titanium alloy [Ti-6Al-4V] surface were studied with respect to their crystallographic changes by X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM).The plasma-treatment of surface was carried out to enhance adhesion of high performance nano reinforced epoxy adhesive, a phenomenon that was manifested in subsequent experimental results. The enhancement of adhesion as a consequence of improved spreading and wetting on metal surface was studied by contact angle (sessile drop method) and surface energy determination, which shows a distinct increase in polar component of surface energy. The synergism in bond strength was established by analyzing the lap-shear strength of titanium laminate. The extent of enhancement in thermal stability of the dispersed nanosilica particles reinforced epoxy adhesive was studied by Thermo Gravimetric Analysis (TGA), which shows an increase in onset of degradation and high amount of residuals at the high temperature range under study. The fractured surfaces of the joint were examined by Scanning electron microscope (SEM).

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.378-382
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• 1999

We evaluated the effect of joining process such as contact method, shape of joined area and pressure on the electrical property of Bi-2223 superconducting tape. It was observed that the current capacity was reduced at the transition area of the joined tape and was significantly dependent on the uniaxial pressure. The lap-joined tape, fabricated with a pressure of 1,000-1,600 MPa, show the highest value of current capacity(80-90%) of the tape itself. It is believed the highest value of current capacity results from improvement in core density, contacting area and grain alignment, etc. In addition, the irreversible strain( ${\varepsilon}$ irrev) for the joined tape· was measured to be 0.1%, smaller than that of enjoined tape( ${\varepsilon}$ irrev = 0.3%). The decrease in the strength and irreversible strain for joined tape is believed to be due to the irregular geometry/morphology of the transition area of the tape.

• Composites Research
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• v.30 no.4
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• pp.254-260
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• 2017

In this paper, we investigated the application method and properties of 0.1 mm, 0.2 mm and 0.3 mm beads, which can secure a certain thickness due to the molding stability of joint surfaces of different materials (aluminum and composite). In order to verify this, the influence was evaluated according to the thickness of the adhesive in the Double lap test and the FEM simulation. As a result, it was confirmed that as the content of the bead of the adhesive increased more than 1%, the strength of the adhesion increased and the elongation decreased. We confirmed as the size of the bead became larger, the rigidity became lower and the elongation increased.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.2
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• pp.89-93
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• 2014

Variable polarity (VP) arc welding is known as an effective solution for aluminum thanks to the cleaning effect, which means oxide removal, during the DCEP (direct current electrode positive) period. In this research, VP GTAW (gas tungsten arc welding) is adopted for lap joint fillet welding of 3mm thickness 5052 aluminum alloy. Various welding currents and DCEP duty cycles are applied as welding conditions with a fixed welding speed to investigate the influence of DCEP characteristics on weld bead formation. Results show a tendency of higher heat input for higher DCEP duty cycle, which result does not follow conventional arc theory because it is known that DCEN (DC electrode negative) polarity is more efficient for heat input than is DCEP. This phenomenonhas recently been reported by several VP-GTA researchers and is still controversial because the mechanism of oxide removal is not yet clear except for the previous, well-known idea of "ion bombardment", which cannot explain the situation. Finally, proper usage conditions for VP-GTAW are suggested; then, further, related theoretical topics in the field of cathode physics are brieflyintroduced.