• Journal of Biosystems Engineering
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• v.25 no.1
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• pp.19-24
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• 2000

This study was carried out to develop gripper which to adaptive variable tray and to develop automatic transplanting system for seedling-production system between tray. This system consisted of five set of gripper and end-effector, a planting-width control unit, a tray transfer unit, and gripper moving device which move gripper between nursing tray and growing tray. This system used push-out rod to grasp plant instead of pull-out end -effector. Several types of fingers, which physically grip seedlings, were also developed and tested to ensure reliable transplanting operation of the gripper. The transplanting system detaches seedlings from a tray with push-o0ut rods, which were installed under the tray transfer unit. The performance of the transplanting system was evaluated by successive transplanting experiments. Using the best type of finger , the transplanting system produced 94.6% of transplanting success rate.

• Journal of the Korea institute for structural maintenance and inspection
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• v.4 no.2
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• pp.131-137
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• 2000

In order to evaluate the design shear strength of composite slabs with truss-shaped shear connectors(TSC), a series of push-out tests on several types of specimens was carried out. The test results for the two parameters of bearing area and solid angle of the connector were compared to obtain the design shear force of the truss-shaped connectors. The results obtained from this study are as follows: (1) The slip-coefficients of TSC ranges from 0.87 to 3.12(${\times}10^6kgf/cm$). (2) The slip stiffness and the shear strength of TSC with $60.6cm^2$ bearing area are greater than those with $14.6cm^2$. (3) For estimating the allowable shear force of TSC, a design equation that is based on the bearing strength of the connector is suggested. (4) The mean safety factors of the critical force and the ultimate force are 2.38 and 4.62. respectively.

• Steel and Composite Structures
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• v.47 no.6
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• pp.729-741
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• 2023

As the most popular shear connection in composite structures, mature concrete has been widely investigated by considering mechanical properties of stud connectors (SCs) embedded. To further enhance the fabrication efficiency of composite structures and solve the contradiction between construction progress and structural performance, it is required to analyze the shear performance of stud connections of composite structures with different concrete ages. 18 typical vertical push-out tests were carried out on stud shear connectors at concrete ages of 7 days, 14 days, and 28 days. Also, the effects of concrete age, stud spacing and stud diameter on the shear capacity, connection stiffness and failure mode of the connectors were studied. A new relationship expression of load-slip for SCs with various concrete ages was proposed. The existing design code for the SCs shear strength was evaluated according to the experimental data, and a more practical prediction equation for the shear capacity of SCs with different concrete ages was established. A great agreement was observed between the experimental and theoretical results, which can provide a reference for engineering practices.

• Restorative Dentistry and Endodontics
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• v.33 no.2
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• pp.98-106
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• 2008

The purpose of this study was to evaluate whether intracanal irrigation method could affect the adhesion between intracanal dentin and root canal filling materials (Gutta-percha/AH 26 sealer and Resilon/Epiphany sealer). Thirty extracted human incisor teeth were prepared. Canals were irrigated with three different irrigation methods as a final rinse and obturated with two different canal filling materials (G groups: Gutta-percha/AH 26 sealer, R groups: Resilon/Epiphany sealer) respectively. Group G1, R1-irrigated with 5.25% NaOCl Group G2, R2-irrigated with 5.25% NaOCl, sterile saline Group G3, R3-irrigated with 5.25% NaOCl, 17% EDTA, sterile saline Thirty obturated roots were horizontally sliced and push-out bond strength test was performed in the universal testing machine. After test, the failure patterns of the specimens were observed using Image-analyzing microscope. The results were as follows. 1. Gutta-percha/AH 26 sealer groups had significantly higher push-out bond strength compared with the Resilon/Epiphany sealer groups (p < 0.05). 2. Push-out bond strength was higher when using 17% EDTA followed by sterile saline than using NaOCl as a final irrigation solution in the Resilon/Epiphany sealer groups (p < 0.05). 3. In the failure pattern analysis, there was no cohesive failure in Group G1, G2, and R1. Gutta-percha/AH 26 sealer groups appeared to exhibit predominantly adhesive and mixed failure patterns, whereas Resilon/Epiphany sealer groups exhibited mixed failures with the cohesive failure occurred within the Resilon substrate.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.08a
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• pp.29-34
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• 2003

In order to study the shearing characteristics of anti-vibration sheet metal which has been bonded by resin, a blanking die of 40.02mm was manufactured to blank a material and it is used to reduce vibrational noise. The variables employed in this study were 1) Clearance 2) types of stripper plate, and 3) types of the die design technique. These variables were used to study the effects on burr height, diameter of product, and camber height. Lastly, the effect of the position of the rubber during blanking was observed. In the case of burr height from experimental investigation, the push-back die, combined with a movable stripper plate, resulted in the concentration of additional pressure between the cutting edges, meaning the crack initiation was delayed. This result was not affected by lubrication, although appropriate lubrication is preferred to enable a longer lasting die in terms of wear, which results from the presence of adhesive as the sheet metal is blanked. In the comparison of diameter measurement, the push-back die, combined with the back pressure from the knock-out plate showed a favorable precision. The use of the push back die with a fixed stripper plate, with a $4.5\%$ clearance, showed better accuracy in the diameter measurement. For comparing camber height, the push back die resulted in less cambering than the drop-through die. Also, the larger the clearance, the greater was the camber height. Considering experimental results, the shearing of anti-vibrational sheet metal is best achieved when the rubber is laying on the top, blanked with a fixed-stripper plate in a push-back die, with a $4.5\%$ clearance.

• Journal of The Korean Society of Integrative Medicine
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• v.4 no.2
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• pp.29-36
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• 2016

Purpose : The purpose of this study was to find out the effects on muscle activations of serratus anterior and upper trapezius muscles when push-up plus exercise togu applied differently depending on the body part. Method : Thirty six volunteers took part in this study and we divided into three groups(upper arm togu group 12, leg togu group 12, upper arm-leg togu group 12). Each experimental group performed push-up plus exercise. All volunteers received a total of 18 exercise session over a 6 week period (three times per week). Exercise program was composed of serratus anterior and upper trapezius push-up plus exercise. Then we measured muscle activation of scapular stabilizer by electromyography. Repeated ANOVA was used to examine the effects of the intervention on each outcome measure. Result : After the six week intervention, there was a significant difference between the pre and 6 week in serratus anterior and upper trapezius muscle activity(p<0.05). After the six week intervention, there was a significant difference among the three group in serratus anterior muscle activity but no significant difference in upper trapezius muscle activity(p>.05). Conclusion : Serratus anterior and upper trapezius showed high muscle activity during push-up plus exercise. Therefore have a positive impact of scapular stabilizer. The larger the area of the unstable support surface, the larger muscle activity was larger of variation quantity.

• Journal of the Korea Furniture Society
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• v.10 no.2
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• pp.1-8
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• 1999

The use of structural wood based panels like plywood, OSB in many applications involves the use of nails, and data on the performance of panel-nail connection are needed for design and comparative purpose. This study was carried out to develop basic information on nail performance(withdrawal, embedding, nailhead push through) with water absorption in plywood and OSB. In withdrawal resistance test, initial stiffness of plywood performed better than OSB in 24hr soaked condition. The soaked condition reduced average nail withdrawal resistance value about 46% (12d mail), 53%(8d nail) in OSB, 17%(12d mail), 24%(8d mail) in plywood. The nail embedding strength of plywood also performed better than that of OSB and retention value(wet strength/dry strength) yielded similar in each nail types. The nail head push through capacity of OSB was higher than that of plywood in dry condition, but equal or lower in soaked condition. Therefore, critical consideration about structural panels is required in moist applications. The average values of nail withdrawal, nail embedding strength and nail head push through resistance of tested materials meet the minimum requirement of various specification and standards.

• Journal of the Korea Society of Computer and Information
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• v.20 no.3
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• pp.115-124
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• 2015

In this paper we analyse the previous (Quality of Services) and QoE(Quality of Experience) methods, and propose a high reliable network system framework and its service forwarding method that is able to provide seamless N-Screen services for proliferating disaster informations. The service satisfaction measurement, i.e., QoE, of contents consumers in N-screens services is going to be important the factor in disaster information proliferation because N-Screen services in the previous methods based on multi devices only focused on information transmission. The proposed system around these services is composed of a disaster information process framework for accepting user's service requirement, push service modules for minimizing the number of packets to be caused when carrying out the push service, and a push service controller for maximizing QoE measures. In order to provide a seamless N-Screen service on diverse screens, such as smartphone, PC, and big screen, we also have Open API(Application Programming Interface) functions. Through these results, we expect to evaluate QoS and QoE quality in the seamless N-Screen service.

• Physical Therapy Korea
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• v.14 no.2
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• pp.44-52
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• 2007

This study was carried out to compare the muscle activities of the shoulder stabilizers between persons with and without winging scapular during push-up plus exercise (adds the scapular protraction to the general push-up exercise). For this study, eleven males with winging scapular and eleven healthy males were recruited. Surface electromyographic (EMG) activity was recorded from the serratus anterior, upper trapezius, lower trapezius, infraspinatus, and pectoralis major while the subjects performed the push-up plus. Each push-up plus was subdivided into three phases according to the elbow position which was measured using the 3-D motion analysis system: elbow flexion (EF), elbow extension (EE), and shoulder protraction phases (SP). Two-way repeated measure ANOVA (phase ${\times}$ group) were used for statistical analysis. There was significant phase by group interaction only on the EMG composition ratio of the serratus anterior (p>.05). The EMG composition ratio of the serratus anterior was significantly higher in SP than in either EF or EE however, it was not different between winging scapular and normal groups. For both groups, the EMG composition ratio of upper trapezius, lower trapezius, and pectoralis major was significantly different across the phases of push-up plus, but the infraspinatus EMG composition ratio was not. For both groups, in EF and EE phases, the EMG composition ratio of both pectoralis major and serratus anterior were relatively higher than that of other muscles. However, in both groups, the EMG composition ratio of the serratus anterior became much more predominant than that of the pectoralis major. In addition, infraspinatus activated greater than pectoralis major. These results showed that the push-up plus exercise is effective to selectively strengthen the serratus anterior for both individuals with and without winging scapular, but not equally effective for other shoulder stabilizers.

• Steel and Composite Structures
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• v.18 no.6
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• pp.1369-1389
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• 2015

In order to investigate the behaviour of lying multi-stud connectors in cable-pylon anchorage zone, twenty-four push-out tests are carried out with different stud numbers and diameters. The effect of concrete block width and tensile force on shear strength is investigated using the developed and verified finite element model. The results show that the shear strength of the lying multi-stud connectors is reduced in comparison with the lying single-stud connector. The reduction increases with the increasing of the number of studs in the vertical direction. The influence of the stud number on the strength reduction of the lying multi-stud connectors is decreased under combined shear and tension loads compared with under pure shear. Yet, due to multi-stud effect, they still can't be ignored. The concrete block width has a non-negligible effect on the shear strength of the lying multi-stud connectors and therefore should be chosen properly when designing push-out specimens. No obvious difference is observed between the strength reductions of the studs with 22 mm and 25 mm diameters. The shear strengths obtained from the tests are compared with those predicted by AASHTO LRFD and Eurocode 4. Eurocode 4 generally gives conservative predictions of the shear strength, while AASHTO LRFD overestimates the shear strength. In addition, the lying multi-stud connectors with the diameters of 22 m and 25 mm both exhibit adequate ductility according to Eurocode 4. An expression of load-slip curve is proposed for the lying multi-stud connectors and shows good agreement with the test results.