• Journal of Biomedical Engineering Research
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• v.36 no.5
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• pp.235-239
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• 2015

The purpose of this study was to investigate the unstable plate system for the advanced balance ability. 7 male volunteers (age $33.7{\pm}1.2$ years, height $174.7{\pm}3.8cm$, weight $86.0{\pm}3.6kg$, BMI $28.2{\pm}2.0kg/m^2$) performed the partial squat motion on the shape of CAP type(${\cap}$) and BOWL type(${\cup}$) plate system. The range of motion (ROM) and muscle activation were acquired by the motion analysis system and the EMG system. Results of ROMs of the CAP type plate system were shown the widely range of the deviation in the ankle joint on the sagittal plane (sagittal plane - hip joint $10.7^{\circ}$ > $5.4^{\circ}$, knee joint $16.3^{\circ}$ > $6.4^{\circ}$, ankle joint $18.8^{\circ}$ > $6.3^{\circ}$ ; transverse plane - hip joint $3.5^{\circ}$ > $1.8^{\circ}$, knee joint $5.3^{\circ}$ > $3.4^{\circ}$, ankle joint $11.3^{\circ}$ > $5.3^{\circ}$ ; frontal plane - hip joint $0.9^{\circ}$ > $0.5^{\circ}$, knee joint $0.8^{\circ}$ > $0.6^{\circ}$, ankle joint $4.8^{\circ}$ > $3.7^{\circ}$). Muscle activation results of the CAP type plate system were indicated higher in major muscles for balance performance than the BOWL type plate system (vastus lateralis 0.90 > 0.62, peroneus longus 0.49 > 0.21, biceps femoris 0.38 > 0.14, gastrocnemius 0.11 > 0.05). These findings may indicate that the CAP type plate system would expect better effectiveness in perform the balance training. This paper is primary study for developing balance skills enhancement training device.

• Journal of Korean Foot and Ankle Society
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• v.11 no.2
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• pp.182-186
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• 2007

Purpose: We examined the relationship of interdigital neuroma occurring site and the surrounding structures, including the deep transverse metatarsal ligament (DTML) by cadaver study and clinical results. Materials and Methods: Seventeen fresh frozen cadavers study were done to evaluate the relationship of interdigital neuroma occuring site and the DTML at two phase of the gait cycle with 60 degree of metatarsophalangeal dorsiflexion and with 15 degrees of ankle dorsiflexion. We measured the distance from interdigital nerve bifurcation of the common digital nerve to anterior margin of the DTML and longitudinal length of DTML itself. Clinically, we checked the location of interdigital neuroma and DTML length during surgery in 32 feet. Results: In the second and third web space, the mean distance from bifurcation of the common digital nerve of foot to the anterior margin of DTML was 16.7 mm, 15.1 mm in the mid-stance position, and 15.9 mm. 14.6 mm in heel-off position. Second, Third web space ligament itself length were average 12.8 mm, 10.6 mm. Clinically, all of the cases of interdigital neuroma started at the bifurcation area of the common digital nerve and interdigital neuroma was average 7.5 mm (range; 6-11 mm). Conclusion: Interdigital neuroma were located more distally than DTML in both the mid-stance and heel off stage. The main lesion was located between metatarsal head and metatarsophalangeal joint and more distal than the DTML anterior margin.

• Archives of Plastic Surgery
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• v.35 no.5
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• pp.527-532
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• 2008

Purpose: Transverse type or volar oblique type of defect of thumb tip can be covered by Moberg flap or second toe pulp free flap. We compared these two methods in functional result, patients' satisfaction, and sensation, etc. to find a better way to cover the defect of the thumb tip. Methods: From 2003 to 2006, we chose the patients randomly with preoperative pictures. The patients had the defect of the thumb tip which is either transverse or volar oblique type. The 6 patients were treated with Moberg flap and other 6 patients were treated with second toe pulp free flap. We have analyzed the results by 2 point discrimination, side pinching power test, pulp to pulp pinching power test, pain scales (visual analogue scale), satisfaction scales of the patients (functional and aesthetic), the degree of the range of motion, etc. Results: All flaps survived without any complications. In the cases of Moberg flaps, the value of static 2 point discrimination test was 5.6 mm, and the value of moving 2 point discrimination test was 4.8 mm. In the cases of second toe pulp free flaps, the values were 9.6 mm and 9.3 mm. In the cases of Moberg flaps, the value of the Side pinch power test was 6.6 kg, 4.4 kg. In the case of second toe pulp free flaps, the values were 4.8 kg and 2.5 kg. The value of aesthetic satisfaction scale of the patients in Moberg flaps was 5.6, the value of functional satisfaction scale of the patients was 3.6. In cases of second toe pulp free flaps, the values were 5.6 and 3.6. The active range of motion of Interphalangeal joint in the cases of Moberg flaps was 46.6 degree, and the active range of motion of metacarpophalangeal joint was 55 degree, in the cases of second toe pulp free flaps, the values were 36.6 degree and 59 degree. Conclusion: As a result, when the defect of the thumb tip is transverse or volar oblique type, we suggest that the operators choose Moberg flap to cover the defect of the thumb tip.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.1
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• pp.19-29
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• 2015

As the half-depth precast concrete decks are increasingly applied to the construction sites, researches on connection details have been increased. For design of concrete bridge deck with half-depth precast panels, it is required to provide appropriate details of transverse loop joints between panels. In this paper, the structural performance of precast decks was evaluated to investigate continuity of the proposed loop joint details. From the results, the validity of the joints for the continuity of deck was observed in the aspect of flexural strength and crack control. The ultimate strength increased 1.52 times as the reinforcement spacing in the joint was reduced. In terms of crack control, direct crack width calculation for the loop joint showed appropriate results comparing with measured crack width.

• Computers and Concrete
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• v.18 no.3
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• pp.297-317
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• 2016

Current codes recommend large amounts of shear reinforcement for reinforced concrete beam-column joints that causes significant bar congestion. Increase in congestion of shear reinforcement in joint core (connection zone), leads to increase accomplishment problems. The congestion may also lead to diameter limitations on the beam bars relative to the joint dimensions. Using double headed studs instead of conventional closed hoops in reinforced concrete beam-column joints reduces congestion and ensures easier assembly of the reinforcing cage. The purpose of this research is evaluating the efficiency of the proposed reinforcement. In this way, 10 groups of exterior beam-column joints are modeled. Each group includes 7 specimens by different reinforcing details in their joint core. All specimens are modeled by using of ABAQUS and analyzed subjected to cyclic loading. After verification of analytical modeling with an experimental specimen, 3D nonlinear specimens are modeled and analyzed. Then, the effect of amount and arrangement of headed studs on ductility, performance, ultimate strength and energy absorption has been studied. Based on the results, all joints reinforced with double headed studs represent better performance compared with the joints without shear transverse reinforcement in joints core. The behavior of the former is close to joints reinforced with closed hoops and cross ties according to the seismic design codes. By adjusting the arrangement of double-headed studs, the decrease in ductility, performance, ultimate moment resistant and energy absorption reduce to 2.61%, 0.90%, 0.90% and 1.66% respectively compared with the joints reinforced by closed hoops on the average. Since the use of headed studs reduces accomplishment problems, these amounts are negligible. Therefore, use of double-headed studs has proved to be a viable option for reinforcing exterior beam-column joints.

• Earthquakes and Structures
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• v.12 no.2
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• pp.237-250
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• 2017

There has been increasing attention in many countries on seismic retrofit of old fashioned RC structures in recent years. In such buildings, the joints lack transverse reinforcement and suffer inadequate seismic dimensional requirements and the reinforcement is plain bar. The behavior of the joints is governed by sliding of steel bars and diagonal shear failure is less influential. Different methods to retrofit beam-column joints have been proposed in the literature such as wrapping the joint by FRP sheets, enlargement of the beam-column joint, and strengthening the joint by steel sheets. In this study, an enlargement technique that uses external prestressed cross ties with steel angles is examined. The technique has already been used for substructures reinforced by deformed bars and has advantages such as efficient enhancement of seismic capacity and lack of damage to the joint. Three reference specimens and two retrofitted units are tested under increasing lateral cyclic load in combination with two levels of axial load. The reference specimens showed relatively low shear strength of 0.150${\surd}$($f_c$) and 0.30${\surd}$($f_c$) for the exterior and interior joints, respectively. In addition, relatively brittle behavior was observed and large deformations extended into the panel zone of the joints. The retrofit method has increased ductility ratio of the interior beam-column joints by 63%, and energy dissipation capacity by 77%, relative to the control specimen; For external joints, these values were 11%, and 94%. The retrofit method has successfully relocated the plastic joints far from the column face. The retrofit method has improved shear strength of the joints by less than 10%.

• International Journal of Highway Engineering
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• v.19 no.1
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• pp.63-72
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• 2017

PURPOSES : The purpose of this study is to investigate the fundamental behaviors such as stresses and deflections of the middle slab in a double-deck tunnel for the development of a middle slab design guide. METHODS : The middle slab has been divided into the following three different sections as according to its structural differences: the normal section, expansion joint section, and emergency passageway section. The normal section of middle slab represents the slab supported by brackets installed continuously along the longitudinal direction of tunnel lining. The expansion joint section refers to a discontinuity of middle slab due to the existence of a transverse expansion joint. The emergency passageway section has an empty rectangular space in the middle slab that acts as an exit in an emergency. The finite element analysis models of these three sections of middle slab have been developed to analyze their respective behaviors. RESULTS : The stresses and deflections of middle slab at the three different sections decrease as the slab thickness increases. The emergency passageway section yields the largest stresses and deflections, with the normal section yielding the smallest. CONCLUSIONS : The stress concentrations at the corners of the passageway rectangular space can be reduced by creating hunch areas at the corners. The stresses and deflections in the emergency passageway section can be significantly decreased by attaching beams under the middle slab in the passageway area.

• Journal of Mechanical Science and Technology
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• v.19 no.10
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• pp.1919-1931
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• 2005

Human joint motion can be kinematically described in three planes, typically the frontal, sagittal, and transverse, and related to experimentally measured data. The selection of reference systems is a prerequisite for accurate kinematic analysis and resulting development of the equations of motion. Moreover, the development of analysis techniques for the minimization of errors, due to skin movement or body deformation, during experiments involving human locomotion is a critically important step, without which accurate results in this type of experiment are an impossibility. The traditional kinematic analysis method is the Angular-based method (ABM), which utilizes the Euler angle or the Bryant angle. However, this analysis method tends to increase cumulative errors due to skin movement. Therefore, the objective of this study was to propose a new kinematic analysis method, Position-based method (PBM), which directly applies position displacement data to represent locomotion. The PBM presented here was designed to minimize cumulative errors via considerations of angle changes and translational motion between markers occurring due to skin movements. In order to verify the efficacy and accuracy of the developed PBM, the mean value of joint dislocation at the knee during one gait cycle and the pattern of three dimensional translation motion of the tibiofemoral joint at the knee, in both flexion and extension, were accessed via ABM and via new method, PBM, with a Local Reference system (LRS) and Segmental Reference system (SRS), and then the data were compared between the two techniques. Our results indicate that the proposed PBM resulted in improved accuracy in terms of motion analysis, as compared to ABM, with the LRS and SRS.

• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4072-4083
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• 2022

Ultrasonic impact treatment (UIT) is carried out on the Ni-based alloy stainless steel pipe gas tungsten arc welding (GTAW) girth weld, the differences of microstructure, microhardness and shear strength distribution of the joint before and after ultrasonic shock are studied by microhardness test and shear punch test. The results show that after UIT, the plastic deformation layer is formed on the outside surface of the Ni-based alloy overlayer, single-phase austenite and γ type precipitates are formed in the overlayer, and a large number of columnar crystals are formed on the bottom side of the overlayer. The average microhardness of the overlayer increased from 221 H V to 254 H V by 14.9%, the shear strength increased from 696 MPa to 882 MPa with an increase of 26.7% and the transverse average residual stress decreased from 102.71 MPa (tensile stress) to -18.33 MPa (compressive stress), the longitudinal average residual stress decreased from 114.87 MPa (tensile stress) to -84.64 MPa (compressive stress). The fracture surface has been appeared obvious shear lip marks and a few dimples. The element migrates at the fusion boundary between the Ni-based alloy overlayer and the austenitic stainless steel joint, which is leaded to form a local martensite zone and appear hot cracks. The welded joint is cooled by FA solidification mode, which is forming a large number of late and skeleton ferrite phase with an average microhardness of 190 H V and no obvious change in shear strength. The base metal is all austenitic phase with an average microhardness of 206 H V and shear strength of 696 MPa.

• Clinics in Shoulder and Elbow
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• v.9 no.2
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• pp.189-195
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• 2006

Purpose: To analyze the result of the accurate open reduction of acromioclavicular (AC) joint and pin fixation, coracoclavicular (CC) screw fixation without CC ligament repair for AC joint injuries. Materials and Methods: Between January 2000 and December 2003, seventeen cases with at least one year follow-up among twenty-one cases underwent operation for AC-CC ligament injuries. A transverse incision approximately 5 cm in length was made over the clavicle, and the AC joint was reduced accurately. Under the image intensifier, a cannulated screw and washer were inserted for the CC ligament. Two Steinman pins were inserted for the AC joint and the AC ligament was repaired with nonabsorbable suture. Gentle passive range of motion was begun postoperative 2 weeks. The pins were removed at $6{\sim}8$ weeks and the screw was removed at $10{\sim}12$ weeks. The results were evaluated by a distance between AC and CC joints on plain films and ASES score at last follow-up. Results: At the last follow-up, there was no limitation of motion and average ASES score was 96($86{\sim}100$ points). There was no failure showing over 5 mm difference of distance compared to opposite side on the plain films. Seven cases had the skin damages and local infection due to pin migration and three cases showed the loosening of CC screw. Conclusion: We could have satisfactory results by accurate reduction of AC joint and simple pins and screw fixation for AC-CC ligament injuries.