• Tribology and Lubricants
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• v.25 no.2
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• pp.86-95
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• 2009

Adhesion tests were carried out in order to investigate the effect of temperature on the adhesion behavior between a PMMA film and a fused silica lens in the micro scale. For the tests, a microtribometer system was specially designed and constructed. The pull-off forces on the PMMA film were measured under atmospheric condition as the temperature of the PMMA film was increased from 300 K to 443 K and decreased to 300 K. The contact area between the PMMA film and the lens was observed during the test. The adhesion behavior was changed with the change of the PMMA surface state as the temperature increased. In glassy state below 363 K, the pull-off force did not change with the increase of temperature. In rubbery state from 383 K to 413 K, the pull-off force increased greatly as the temperature increased. In addition, the area of contact was enlarged. In viscous state above 423 K, the fingering instability was observed in the area of contact when the PMMA film contacted with the lens. It was also found that the adhesion behavior can be varied with the thermal history of the PMMA film. The residual solvent in the PMMA film could emerge to the PMMA surface due to the heating and reduced the pull-off force.

• Journal of Satellite, Information and Communications
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• v.12 no.2
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• pp.33-37
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• 2017

This paper suggests a new reliable push pull converter. The proposed push-pull converter have additional two diodes comparing with conventional push-pull converter. When one of two MOSFETs of the push-pull converter is on state, the other MOSFET is automatically off state due to adding additional diodes. Therefore, the converter is under electric noise environments, the converter avoids short circuit due to turning on of two MOSFETs. In this paper, the suggested converter has been simulated by PLECS software for 100 kHz switching frequency. In simulation, the current of the converter switches increases about 10 % for $20{\mu}sec$ electric noise environments. However, the converter operates very reliably without any short circuit conditions.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.9
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• pp.471-475
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• 2001

ln this paper, a micromachined micromechanical switch is presented. The presented switch is operated in the vertical direction to the substrate by an electrostatic force between two parallel plates. The moving plate is pulled down to connect the bumps of the bias node$(V_{DD}/ or GND)$ to the bumps of the output node when a oltage difference exists between the moving plate and the input plate. The switch was designed to operate at a low switching voltage$(\risingdotseq5V)$ by including a large-area, narrow-gap, parallel plate capacitor A theoretical analysis of the designed switch was performed in order to determine its geometry fitting the desired pull-in voltage and release voltage. The designed switch was fabricated by surface micromachining combined with Ni electroplating. From the experimental results of the fabricated switch, its pull-in voltage came Out to be less than 5V and the measured maximum allowable current was 150mA. The measured average ON-state resistance was about 8$\Omega$, and the OFF-state resistance was too high to be measured with digital multimeter.

• Structural Engineering and Mechanics
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• v.5 no.4
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• pp.339-353
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• 1997

Fiber reinforced plastic (FRP) rods provide certain benefits over steel as concrete reinforcement, such as corrosion resistance, magnetic and electrical insulation, light weight, and high strength. FRP composites can be combined with a steel core to form hybrid reinforcing rods that take advantage of properties of both materials. The objective of this study was to characterize the bond behavior of hybrid FRP rods made with braided epoxy-impregnated aramid or poly-vinyl alcohol FRP skins. Eleven rod types were tested using two concrete strengths. Specific topics examined were bond strength, slip, and type of failure in concentric pull-out tests from concrete cubes. From analysis of identical pull-out tests on both hybrid and steel rods, information on relative bond strength and behavior were obtained. It is concluded that strength is similar but slip in hybrid rods is much higher. Hybrid rods failed either by pull-out or splitting the concrete block (with or without yielding of the steel core). Experimental data showed consistency with similar test results presented in the literature.

• Archives of Plastic Surgery
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• v.35 no.6
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• pp.723-728
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• 2008

Purpose: The disinsertion of the phalangeal tendon distal insertion has difficulties in ordinary tenorrhaphy operation for the anatomical features, and still has controversy between non-surgical and surgical management. The purpose of this study is to select treatment for the injury of the phalangeal tendon distal insertion, as we've had a good results from operation treatment with Pull-in suture technique. Methods: We reviewed the hospital records of 12 patients treated with Pull-in suture technique with disinsertion of the phalangeal extensor or flexor tendon distal insertion from June 2006 to June 2007. Eight patients were involved with the tendon disinsertion without bone fracture, and 4 patients were involved with the fracture of the phalangeal tendon distal insertion site. After removal of the K-wire in week 6, active physical exercises were commenced immediately. The mean follow-up period was 12.4 months. Results: All the patients who had tendon disinsertion with bone fracture had IIB, by Wehbe and Schneider's classification 2, and we evaluated the results comparing the same finger of the other hand according to Crawford's evaluation criteria 5. The nine excellent and three good results were obtained and there were no limitation of motor for the patient who had operation for the rupture of flexor tendon as well. There were no particular complications during the follow-up period. Conclusion: The most important thing for the disinsertion of the phalangeal tendon distal insertion is to maintain an accurate and durable reduction state keeping the tension of tendon. At this point, after removal of the K-wire, the Pull-in suture technique allows accurate realignment of the tendon-bone unit without any specific instrumentation under the more stable state. The Pull-in suture technique seems to be a strong alternative for the treatment of disinsertion of the phalangeal tendon distal insertion, with successful treatment outcome(rapid functional recovery and high patient satisfaction).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1289-1295
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• 2008

Recently, it is progressing a study for supporting various application services using OpenAPI(Application Program Interface). But it is not enough a study related OpenAPI(Open Application Interface) to access many collected context data of sensor networks for ubiquitous application services. Therefor, this paper presents Pull/Push service model based on sensor networks, and implements OpenAPI fer Pull/push application services. And, we design and implement OpenAPI using web service for Pull application services. This Pull OpenAPI supports users the context data of temperature and humidity using the remote service based on .Net framework in sensor networks. And, we design and implement OpenAPI using TCP/IP socket interface for Push application services in sensor network. This Push OpenAPI provides users a state of temperature, humidity collecting in sensor networks. Consequently, user can develop easily various application services as supporting OpenAPI instead of closed application interface of sensor networks based on existed specific database.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.15-21
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• 2008

It is generally known that the PRAT(Plysteer Residual Aligning Torque) is one of indicating a performance factors of a tire for assessing the vehicle pull, also tire pattern shape, which means lateral groove angle, is very important tire design factor in relation to the PRAT. Lateral grooves of tire pattern are widely divided into center and shoulder parts. So, this paper has studied the correlation between the PRAT and their lateral groove angles using FEM. Especially, the steady state rolling analysis among tire rolling analysis methods has been used for the PRAT performance study. Firstly, analysis result data have been compared with the experimental data to validate FE analysis for PRAT. Next, the PRAT due to the lateral groove angle about PCR(Passenger Car Radial) tire and SUV tire has been analyzed. The tendency of the PRAT due to the lateral groove angles can be used as a guide line for the tire design in relation to vehicle pull.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1105-1108
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• 2005

Media service model is divided into 3 models that are Client Pull, Server Push, and IPP(Interleaving Pull & Push) model. In most single VOD(Video On Demand) environment, Client Pull model was sufficient to play the movie Because most media contents has a low bitrate and resolution. But according to an increment of the demand of the high definition media, Client Pull model is not sufficient. Parallel VOD environment is made of several of VOD servers and provides the parallel media stream simultaneously for one client. We compared and analyzed the performance of service models with respect to network delay and data size in buffer in the single and parallel VOD environment and we found that IPP service model keeps the least network delay and stable client buffer state in the parallel VOD environment.

• Journal of Microbiology
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• v.44 no.5
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• pp.577-580
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• 2006

GST pull-down assays were used to characterize the SARS-CoV membrane (M) and nucleocapsid (N) interaction, and it was found that the amino acids 211-254 of N protein were essential for this interaction. When tetrad glutamines (Q) were replaced with glutamic acids (E) at positions of 240-243 of the N protein, the interaction was disrupted.

• Journal of Power Electronics
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• v.14 no.3
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• pp.444-457
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• 2014

This paper presents the design and realization of a digital PV simulator with a Push-Pull Forward (PPF) circuit based on the principle of modular hardware and configurable software. A PPF circuit is chosen as the main circuit to restrain the magnetic biasing of the core for a DC-DC converter and to reduce the spike of the turn-off voltage across every switch. Control and I/O interface based on a personal computer (PC) and multifunction data acquisition card, can conveniently achieve the data acquisition and configuration of the control algorithm and interface due to the abundant software resources of computers. In addition, the control program developed in Matlab/Simulink can conveniently construct and adjust both the models and parameters. It can also run in real-time under the external mode of Simulink by loading the modules of the Real-Time Windows Target. The mathematic models of the Push-Pull Forward circuit and the digital PV simulator are established in this paper by the state-space averaging method. The pole-zero cancellation technique is employed and then its controller parameters are systematically designed based on the performance analysis of the root loci of the closed current loop with $k_i$ and $R_L$ as variables. A fuzzy PI controller based on the Takagi-Sugeno fuzzy model is applied to regulate the controller parameters self-adaptively according to the change of $R_L$ and the operating point of the PV simulator to match the controller parameters with $R_L$. The stationary and dynamic performances of the PV simulator are tested by experiments, and the experimental results show that the PV simulator has the merits of a wide effective working range, high steady-state accuracy and good dynamic performances.