• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.422-425
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• 2002

Position balance control refers to ability that is kept bodily center of gravity under minimum position shake on surface of land. Patients who an injury of brain, a wound of the central nervous system or weakening of leg muscular power is fallen are trend increasing steadily by the car accident body balance function is on an increasing trended. These patients have difficulty in position balance control, receive big restriction walk and life style. This research composed to do body balance function rehabilitation training which elevate leg muscular power using step machine. And expect to become effective rehabilitation training device because measuring bodily pressure center using Force Platform and do so that can confirm training result easily as that is monitor.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.188-189
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• 2013

The purpose of this research is to comprehend experimentally the characteristic of human dynamic load and provide the result as basic data to suggest a valid impact-resistance evaluation method. Human motions exerting dynamic load are classified to 3 types. Selecting 3 ranks of motion strength, 3 ranks of load plane stiffness (A:20kN/cm, B:4.7kN/cm, C:2.2kN/cm), and 30 male grownup inspectors in their twenties, load was measured when they applied force on load plane. Result of this research is as follows: (1) Human dynamic load has different nature from object collision in the highest load ratio depending on the load plane stiffness and action time (2) The highest load ratio for each motion was 10.06 for kicking, 4.44 for hitting with shoulder, and 5.58 for fist blow.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.192-193
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• 2013

The purpose of this research is to comprehend experimentally the nature of human static load to wall for making use of the result as basic data to evaluate resisting force of lightweight wall. Human motions exerting static load are classified to 4 types, and two-hands pushing and shoulder pushing are defined as the instantaneously forcing motions with hands or shoulder put on the load plate, respectively. Back leaning and one-hand leaning are defined as motions of taking a rest in their respective comfortable posture. Measurement of static horizontal load caused by each motion showed that the highest load ratio depends on hardness of load plane and was 1.17~1.25 times of weight in two-hands pushing, 0.95~0.99 times in shoulder pushing, 0.16~0.18 times in back leaning, and 0.12~0.15 times in one-hand leaning.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.18-20
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• 2001

This paper describes are quenching chambers of three type for Magnetic Switch and analyzes electromagnetic blowout force acting on the arc using 3D finite element method we make prototype device of each model and establish characteristics of arc quenching by measuring arcing time. This paper compares electromagnetic blowout to inverse arcing time. As the result this proposes the improving method for arc quen performance in DC magnetic switch.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.877-880
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• 2008

In this article, in order to fabricate polymer based electrospray device with super hydrophobic nozzle we use PTFE(polyfluorotetraethylene) plate and PMMA(polymethylmethacrylate). To obtain the super hydrophobic surface nozzle, PTFE surface is treated by argon and oxygen plasma treatment process. And evaluate the treated surface, perform measuring contact angle, SEM(Scanning Electron Microscope) and AFM(Atomic Force Microscope). We compare the performance of the super hydrophobic PTFE surface nozzle with raw PTFE and PMMA surface nozzle. For the ion beam treated PTFE nozzle, the liquid doesn't overflow and it keeps initial position and meniscus shape. From these results, we expect in cease of superhydrophobic surface nozzle jetting becomes more stable and repeatable.

• Journal of Drive and Control
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• v.16 no.2
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• pp.1-7
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• 2019

Jaw crusher is a device that breaks rock collected from mines or quarries to produce aggregates of the size desired by user. A representative method for measuring load is to measure them by attaching force sensors directly to the part where the load is generated. However, the direct method has many limitations such as high-impact loads generation in equipment or space constraints, sensor capacities and costs. Therefore, Transfer Path Analysis (TPA) was used to indirectly measure impact loads by attaching acceleration sensors. In this study, both direct and TPA methods were used to measure the impact load of Jaw crusher. This study finally quantifies the impact of the load generated by the Jaw crusher using direct method and TPA method, and comparing the impact load measured calculated the derive the error rate.

• Steel and Composite Structures
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• v.18 no.6
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• pp.1423-1450
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• 2015

The paper presents the details and results of an experimental study on bolted end-plate joints of industrial type steel building frames. The investigated joints are commonly used in Lindab-Astron industrial buildings and are optimized for manufacturing, erection and durability. The aim of the research was to provide an experimental background for the design model development by studying load-bearing capacity of joints, bolt force distribution, and end-plate deformations. Because of the special joint details, (i.e., joints with four bolts in one bolt-row and HammerHead arrangements), the Eurocode 3 standardized component model had to be improved and extended. The experimental programme included six different end-plate and bolt arrangements and covered sixteen specimens. The steel grade of test specimens was S355, the bolt diameter M20, whereas the bolt grade was 8.8 and 10.9 for the two series. The end-plate thickness varied between 12 mm and 24 mm. The specimens were investigated under pure bending conditions using a four-point-bending test arrangement. In all tests the typical displacements and the bolt force distribution were measured. The end-plate plastic deformations were measured after the tests by an automatic measuring device. The measured data were presented and evaluated by the moment-bolt-row force and moment-distance from centre of compression diagrams and by the deformed end-plate surfaces. From the results the typical failure modes and the joint behaviour were specified and presented. Furthermore the influence of the end-plate thickness and the pretension of the bolts on the behaviour of bolted joints were analysed.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.4
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• pp.465-473
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• 1999

Bond strength of luting cements to dentin is a critical consideration for success of complete cast crowns. This study was performed to evaluate the relationship between surface characteristics of teeth prepared for complete cast crowns and retention of cemented restorations. Eighty artificial crowns were cast for standardized complete crown tooth preparations accomplished with the use of a special device on recently extracted human teeth. Coarse diamond(#102R, Shofu) and superfine finishing diamond(#SF102R, Shofu) burs of similar shape were used. Crowns in each group were randomly subdivided into few subgroups of 10 for luting cements selected for this study: zinc phosphate cement (FLECK' S), polycarboxylate cement (Poly-F), rein-forced glass ionomer cement (Fuji PLUS). and adhesive resin cement (Panavia 21). Retention was evaluated by measuring the tensile load required to dislodge the artificial crown from tooth preparations with an Instron testing machine, and analysed by one-way ANOVA and Student's t-test. The obtained results were as follows ; 1. When tooth preparation was done with coarse diamond bur, retentive force was diminished in order of Panavia 21 Fuji PLUS, FLECK'S, and Poly-F. Retentive forces showed the significant difference between Fuji PLUS group and FLECK'S group(p<0.001). 2. When tooth preparation was done with superfine diamond bur, retentive force was diminished in order of Fuji PLUS, Panavia 21, FLECK'S, and Poly-F. Retentive forces showed the significant difference between Panavia 21 group and FLECK'S group(p<0.001). 3. Retentive force in coarse tooth surfaces was significantly higher than that in superfine tooth surface with all luting cements(p<0.001), and cement residues were almost retained with-in the cast crown in all groups.

• Structural Engineering and Mechanics
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• v.71 no.4
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• pp.391-405
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• 2019

Compared to the ambient vibration test mainly identifying the structural modal parameters, such as frequency, damping and mode shapes, the impact testing, which benefits from measuring both impacting forces and structural responses, has the merit to identify not only the structural modal parameters but also more detailed structural parameters, in particular flexibility. However, in traditional impact tests, an impacting hammer or artificial excitation device is employed, which restricts the efficiency of tests on various bridge structures. To resolve this problem, we propose a new method whereby a moving vehicle is taken as a continuous exciter and develop a corresponding flexibility identification theory, in which the continuous wheel forces induced by the moving vehicle is considered as structural input and the acceleration response of the bridge as the output, thus a structural flexibility matrix can be identified and then structural deflections of the bridge under arbitrary static loads can be predicted. The proposed method is more convenient, time-saving and cost-effective compared with traditional impact tests. However, because the proposed test produces a spatially continuous force while classical impact forces are spatially discrete, a new flexibility identification theory is required, and a novel structural identification method involving with equivalent load distribution, the enhanced Frequency Response Function (eFRFs) construction and modal scaling factor identification is proposed to make use of the continuous excitation force to identify the basic modal parameters as well as the structural flexibility. Laboratory and numerical examples are given, which validate the effectiveness of the proposed method. Furthermore, parametric analysis including road roughness, vehicle speed, vehicle weight, vehicle's stiffness and damping are conducted and the results obtained demonstrate that the developed method has strong robustness except that the relative error increases with the increase of measurement noise.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.6
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• pp.517-521
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• 2016

General industrial robots are difficult to use for precision assembly because they are operated based on position control. Their position accuracy is also usually higher than the assembly clearance (several tens of ${\mu}m$). In previous researches, force control was suggested as a robotic assembly solution. However, this method is difficult to apply in reality because of speed and cost problems. The RCC provides high speed, but applications are limited because the compliance is fixed, and it cannot detect an assembly condition during a task. A variable passive compliance device (VPCD) was developed herein. The VPCD can detect the assembly condition during tasks. This device can provide proper compliance for successful assembly tasks. The pneumatic system and the Stewart platform with an LVDT sensor were applied for measuring the displacement and variable compliance, respectively. The concept design and analysis were conducted to prove the effectiveness of the developed VPCD.