• Journal of Korean society of Dental Hygiene
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• v.13 no.6
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• pp.1079-1086
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• 2013

Objectives : It is considered that the education of cardiopulmonary resuscitation and the preparation for quick response to cardiac arrest are very important to dental hygiene students who get employed in dental clinics and hospitals after graduation. The purpose of the study is to investigate the perception, attitude and knowledge of cardiopulmonary resuscitation(CPR) in dental hygiene students and to provide basic data to educate CPR education program for the dental hygiene students. Methods : The study subjects were 260 students in the department of dental hygiene in J city health college. A self-reported questionnaire was conducted from May 1st to 31st 2013. A frequency analysis and x2-test was carried out to confirm the general characteristics of the 260 respondents. Results : The perception rate of the CPR was 55.8%(145 persons). There were positive correlations between perception and attitude of CPR (r=.202) and attitude and knowledge(r=.249). Conclusions : CPR performance is the vital to the cardiac arrest victim. So it is necessary to educate the dental hygiene students in case of emergency situation. It is necessary to educate CPR and basic life support (BLS) in dental hygiene students.

• International Journal of Highway Engineering
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• v.8 no.2 s.28
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• pp.37-47
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• 2006

The structural response and performance of a flexible pavement can be improved through the use of geogrids as base course reinforcement. Current ongoing research at the University of illinois has focused on the development of a geogrid base reinforcement mechanistic model for the analysis of reinforced pavements. This model is based on the finite element methodology and considers not only the nonlinear stress-dependent pavement foundation but also the isotropic and anisotropic behavior of base/subbase aggregates for predicting pavement critical responses. An axisymmetric finite element model was developed to employ a three-noded axisymmetric membrane element for modeling geogrid reinforcement. The soil/aggregate-geogrid interface was modeled by the three-noded membrane element and the neighboring six-noded no thickness interface elements. To validate the developed mechanistic model, the commercial finite element program $ABAQUS^{TM}$ was used to generate pavement responses as analysis results for simple cases with similar linear elastic material input properties. More sophisticated cases were then analyzed using the mechanistic model considering the nonlinear and anisotropic modulus property inputs in the base/subbase granular layers. This paper will describe the details of the developed mechanistic model and the effectiveness of geogrid reinforcement when used in different quality unbound aggregate base/subbase layers.

• Journal of Auto-vehicle Safety Association
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• v.5 no.2
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• pp.45-50
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• 2013

The whiplash Injuries due to rear collision occur frequently. As result, in many countries, seat performance is being assessed and developed to improve head whiplash injury in rear collision of passenger car. This study compares whiplash assessment methods in each country. Using the DFSS(Design for Six Sigma) method, the correlation between influence parameters of head restraints and whiplash injury criteria is analyzed. Four control factors are used in this study. And total 11 whiplash injury criteria from NCAP(New Car Assessment Program) of Korea, Europe, China and IIHS(Insurance Institute for Highway Safety) of USA are used for output response. By the experimental design, L9 orthogonal coordinate system is configured and is tested by sled test equipment, twice. By using average assay value and ANOVA, the correlation between control factors and injury criteria has been comprehended. Optimization design of head restraint according the regional seat safety assessment was derived through the correlation.

• Journal of the Korean Solar Energy Society
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• v.31 no.5
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• pp.119-125
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• 2011

In this paper, we have studied about minimizing the Energy Storage System (ESS) capacity for mitigating the fluctuation of Wind Turbine Generation System (WTGS) by using Electric Double Layer Capacitor (EDLC) and Battery Energy Storage System (BESS). In this case, they have some different characteristics: The EDLC has the ability of generating the output power at high frequency. Thus, it is able to reduce the fluctuation of WTGS in spite of high cost. The BESS, by using Li-Ion battery, takes the advantage of high energy density, however it is limited to use at low frequency response. To verify the effectiveness of the proposed method, simulations are carried out with the actual data of 2MW WTGS in case of worst fluctuation of WTGS is happened. By comparing simulation results, this method shows the excellent performance. Therefore, it is very useful for understanding and minimizing the ESS capacity for mitigating the fluctuation of WTGS.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.2
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• pp.121-126
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• 2002

Due to few earthquakes in our country, one generally has thought to be safe from earthquakes. However, severe earthquakes occurred in Dangsan and Hyogohyeon which one had regarded as the zone that had not been risky for earthquakes, so that so many people died and a lot of buildings and bridges were destroyed. This event surprised our country and we undertook preparation for earthquakes on the full scale. The concept of seismic design was induced in the country which was poor in it for the scarcity of recognition and insufficiency of funds. Recently, many specialists are enforcing the provisions of seismic design. Therefore, this study introduces the method which combines PC-LEADeR( design program for L.R.B.) with LUSAS(linear elastic analysis) and performs the seismic isolation design more elaborately and simply. It verifies the propriety of that method, and it also examine the factors that affect the response of the bridges. Seismic isolation design for bridge using L.R.B. provides both economical efficiency and superior seismic performance. Second, the results between by the method proposed and by time history analysis have 20% error at the maximum. That is, the method proposed very appropriate.

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.1
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• pp.218-227
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• 2001

The purpose of this study was to estimate that the relations of weathering speed and shear strength of granite soil by tracing the weathering depth of granite soil from the very moment of its cutting. The results obtained this follows : This paper is about seismic performance of the EDF(Electricite De France) system, that is among various base isolator. A rational modeling of EDF system has been presented that used Nllink element. We get theoretical solutions of equation of motion of the system and compared with numerical solutions using a finite element program. The unification modeling is made by comparing with behavior using Newmark-${\beta}$ method when input earthquake acceleration data. Thus, a verified modeling will apply bridge structures or multi-degree of-freedom systems.

• Structural Engineering and Mechanics
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• v.42 no.1
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• pp.73-93
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• 2012

With an active structural involvement in spiral case structure (SCS) that is always the design and research focus of hydroelectric power plant (HPP), the compressible membrane sandwiched between steel spiral case and surrounding reinforced concrete was often assumed to be linear elastic material in conventional design analysis of SCS. Unfortunately considerable previous studies have proved that the foam material serving as membrane exhibits essentially nonlinear mechanical behavior. In order to clarify the effect of membrane (foam) material's nonlinear stress-strain behavior on SCS, this work performed a case study on SCS with a compressible membrane using the ABAQUS code after a sound calibration of the employed constitutive model describing foam material. In view of the successful capture of fitted stress-strain curve of test by the FEM program, we recommend an application and dissemination of the simulation technique employed in this work for membrane material description to structural designers of SCS. Even more important, the case study argues that taking into account the nonlinear stress-strain response of membrane material in loading process is definitely essential. However, we hold it unnecessary to consider the membrane material's hysteresis and additionally, employment of nonlinear elastic model for membrane material description is adequate to the structural design of SCS. Understanding and accepting these concepts will help to analyze and predict the structural performance of SCS more accurately in design effort.

• Earthquakes and Structures
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• v.6 no.5
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• pp.561-580
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• 2014

After strong earthquakes conventional frames used worldwide in multi - story steel buildings (e.g. moment resisting frames) are not well positioned according to reparability. Two innovative systems for seismic resistant steel frames incorporated with dissipative fuses were developed within the European Research Program "FUSEIS" (Vayas et al. 2013). The first, FUSEIS1, resembles a vertical Vierendeel beam and is composed of two closely spaced strong columns rigidly connected to multiple beams. In the second system, FUSEIS2, a discontinuity is introduced in the composite beams of a moment resisting frame and the dissipative devices are steel plates connecting the two parts. The FUSEIS system is able to dissipate energy by means of inelastic deformations in the fuses and combines ductility and architectural transparency with stiffness. In case of strong earthquakes damage concentrates only in the fuses which behave as self-centering systems able to return the structure to its initial undeformed shape. Repair work after such an event is limited only to replacing the fuses. Experimental and numerical investigations were performed to study the response of the fuses system. Code relevant design rules for the seismic design of frames with dissipative FUSEIS and practical recommendations on the selection of the appropriate fuses as a function of the most important parameters and member verifications have been formulated and are included in a Design Guide. This article presents the design and performance of building frames with FUSEIS 1-1 based on models calibrated on the experimental results.

• Journal of Mechanical Science and Technology
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• v.17 no.8
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• pp.1140-1147
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• 2003

We have examined the effect on neck-muscle activation of altering whole body posture. A Rhesus monkey (Macaca mulatta) was trained to produce sinusoidal (0.25 Hz) head tracking movements in the sagittal plane when seated with trunk and head vertical or while standing in the quadrupedal position. Video-fluoroscopic images of cervical vertebral motion, and electromyographic (EMG) responses were recorded simultaneously. Results demonstrated that vertebral motion varied with body posture, occurring synchronously between all joints in the upright position and primarily at skull-$C_1$ when in the quadrupedal position. Muscle EMG activation was significantly greater (P<0.001) in the quadrupedal position than when upright for all muscles except semispinalis cervicis. Peak activation of all the muscles occurred prior to peak head extension in the quadrupedal position, suggesting synchronous activity between muscles. Data suggest that, when upright, muscles were activated in functional groupings defined by their anatomical arrangement. In the quadrupedal position, gravity acting on the horizontally oriented head produced greater activation and a collective response of the muscles.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.8 no.2
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• pp.90-95
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• 2009

All-optical fiber-type gain flattening filer (GFF) for an EDFA (Erbium doped fiber amplifier) were fabricated by using a FBT (fiber biconical tapered) process and the performance of the GFF was tested and athermal package was proposed. Historically, the chief contributor to gain unevenness has been the EDFA. Due to the inherent gain response of the EDFA's operation, there is always a modest imbalance in the gain applied as a function of wavelength. FBT methods have been used to make fiber type couplers and WDM filter since 1980. Attractivity of this methods was simple, cost effective and thermal stability. Simulation program tool is made to design target GFF profile for this paper. Fiber coupler manufacturing machine is modified for the GFF process. The final GFF is obtained by cascading 4 unit filter that has 6 taper stage. Test result shows 1 dB of wavelength flatness in the C band. Polarization dependent loss is under 0.15dB. The center wavelength variation is below ${\pm}$0.35nm at the temperature range of $20^{\circ}C$ to $70^{\circ}C$.