• Journal of Korean Neurosurgical Society
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• v.49 no.4
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• pp.212-216
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• 2011

Objective : It is well known that plate-to-disc distance (POD) is closely related to adjacent-level ossification following anterior cervical plate placement. The study was undertaken to compare the outcomes of two different anterior cervical plating methods for degenerative cervical condition. Specifically, the new method involves making holes for plate screws first with an air drill and then choosing a plate size. The other method was standard, that is, decide on the plate size first, locate the plate on the anterior vertebral body, and then drilling the screw holes. Our hypothesis was that the new technical tip may increase POD as compared with the standard anterior cervical plating procedure. Methods : We retrospectively reviewed 49 patients who had a solid fusion after anterior cervical arthrodesis with a plate for the treatment of cervical disc degeneration. Twenty-three patients underwent the new anterior cervical plating technique (Group A) and 26 patients underwent the standard technique (Group B). POD and ratios between POD to anterior body heights (ABH) were measured using postoperative lateral radiographs. In addition, operating times and clinical results were reviewed in all cases. Results : The mean durations of follow-up were $16.42{\pm}5.99$ (Group A) and $19.83{\pm}6.71$ (Group B) months, range 12 to 35 months. Of these parameters mentioned above, cephalad POD (5.43 versus 3.46 mm, p=0.005) and cephalad POD/ABH (0.36 versus 0.23, p=0.004) were significantly greater in the Group A, whereas operation time for two segment arthrodesis (141.9 versus 170.6 minutes, p=0.047) was significantly lower in the Group A. There were no significant difference between the two groups in caudal POD (5.92 versus 5.06 mm), caudal POO/ABH (0.37 versus 0.32) and clinical results. Conclusion : The new anterior cervical plating method represents an improvement over the standard method in terms of cephalad plate-to-disc distance and operating time.

• Journal of The Korean Astronomical Society
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• v.21 no.2
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• pp.155-171
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• 1988

We have examined how sensitively the extinction value determined by the method of star-count depends on such factors as the plate limit, the size of counting reseau, the non-linearity in the number distribution of stars with magnitude, and the angular resolution demanded by the given problem. We let the Poisson distribution portray the statistical nature of the countings, and chose the region containing the globule Barnard 361 as an example field. Uncertainties due to various combinations of the factors are presented in graphic forms: (1) Dynamic range in the extinction measurements is evaluated as a function of reseau size for varying plate limits. (2) Statistical errors involved in the star-count are analized in terms of the signal-to-noise ratio, the plate limit and the reseau size. (3) Systematic error due to the non-linearity in the number distribution are thoroughly analized. (4) Finally, a methodology is presented for correcting the systematic error in the observed radial density gradient. These graphs are meant to be used in selecting proper size of the reseau and in estimating errors inherent to the star-count analysis.

• Journal of Welding and Joining
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• v.30 no.1
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• pp.64-71
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• 2012

The characteristics of high heat input (342kJ/cm) EG (Electro Gas Arc) welded joint of EH36-TM steel has been investigated. The weld metal microstructure consisted of fine acicular ferrite (AF), a little volume of polygonal ferrite (PF) and grain boundary ferrite (GBF). Charpy impact test results of the weld metal and heat affected zone (HAZ) met the requirement of classification rule (Min. 34J at $-20^{\circ}C$). In order to evaluate the relationship between the impact toughness property and the grain size of HAZ, the austenite grain size of HAZ was measured. The prior austenite grain size in Fusion line (F.L+0.1 mm) was about $350{\mu}m$. The grain size in F.L+1.5 mm was measured to be less than $30{\mu}m$ and this region was identified as being included in FGHAZ(Fine Grain HAZ). It is seen that as the austenite grain size decreases, the size of GBF, FSP (Ferrite Side Plate) become smaller and the impact toughness of HAZ increases. Therefore, the CGHAZ was considered to be area up to 1.3mm away from the fusion line. Results of TEM replica analysis for a welded joint implied that very small size ($0.8\sim1.2{\mu}m$) oxygen inclusions played a role of forming fine acicular ferrite in the weld metal. A large amount of (Ti, Mn, Al)xOy oxygen inclusions dispersed, and oxides density was measured to be 4,600-5,300 (ea/mm2). During the welding thermal cycle, the area near a fusion line was reheated to temperature exceeding $1400^{\circ}C$. However, the nitrides and carbides were not completely dissolved near the fusion line because of rapid heating and cooling rate. Instead, they might grow during the cooling process. TiC precipitates of about 50 ~ 100nm size dispersed near the fusion line.

• Journal of computational fluids engineering
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• v.19 no.1
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• pp.21-26
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• 2014

Butterfly valve is a valve that controls fluid flow depending on the size of the opening angle. In general, the size of the opening angle of the valve increases, the fluid flow has also increased sharply. However, sometimes, in a specific piping system, a particular operating condition is needed that the fluctuation of the fluid flow should not have large amount although the size of opening angle of the valve become larger. In butterfly value, the shape of a typical thin plate, it is impossible to control a minute fluid, but in thick plate type, it is possible. In this study, we got the fluid flow control characteristics and pressure drop through both a numerical method and an experimental method about thick plate type. The numerical result and experimental result of flow coefficient show a similar pattern. In addition, we could find that minute fluid flow control was possible in the area of small size of the opening angle.

• Steel and Composite Structures
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• v.28 no.1
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• pp.99-110
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• 2018

In this paper, a new size-dependent quasi-3D plate theory is presented for wave dispersion analysis of functionally graded nanoplates while resting on an elastic foundation and under the hygrothermaal environment. This quasi-3D plate theory considers both thickness stretching influences and shear deformation with the variations of displacements in the thickness direction as a parabolic function. Moreover, the stress-free boundary conditions on both sides of the plate are satisfied without using a shear correction factor. This theory includes five independent unknowns with results in only five governing equations. Size effects are obtained via a higher-order nonlocal strain gradient theory of elasticity. A variational approach is adopted to owning the governing equations employing Hamilton's principle. Solving analytically via Fourier series, these equations gives wave frequencies and phase velocities as a function of wave numbers. The validity of the present results is examined by comparing them with those of the known data in the literature. Parametric studies are conducted for material composition, size dependency, two parametric elastic foundation, temperature and moisture differences, and wave number. Some conclusions are drawn from the parametric studies with respect to the wave characteristics.

• Journal of Nutrition and Health
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• v.32 no.8
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• pp.967-973
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• 1999

The purpose of this study was to analyze sensory evaluation, to assess visual serving size and plate waste estimates of daily menu, and the identify customer expectation, perception and satisfaction. Questionnaires of sensory evaluation, serving size and were waste were developed and hand-delivered to 2,520 people. A total of 2,255 questionnaires were usable: a 89.5% response rate. Customer satisfaction questionnaires were handed out to 700 customers: (100 each at seven operations). A total of 551 were returned completed (78.7%). The data was analyzed using the SAS package program for Descriptive Analysis, t-test and ANOVA. The result of sensory evaluation showed that 'taste' was 3.20, 'freshness' 3.17, 'temperature' 3.25, 'texture' 3.15, 'appearance' 3.12, 'overall evaluation' 3.21, so these were little higher than 「normal」, that is 3.0. There was positive correlation among 'taste', 'freshness', 'temperature', 'texture', 'appearance' and 'overall evaluation'(p<.001). Serving size score was 2.97 and plate waste was 4.87, thus plate waste percentage was about 22-33%. As the result of customer expectation, perception and satisfaction of menu quality, characteristics. Customer satisfaction was defined as the difference expectation and perception and customer perceptions in theis survey were lower than expectation, thus this result implied customers dissatisfied in all menu quality characteristics. IPA analysis showed that 'diversity of menu selection' and 'menu price' was included in A area 'Focus here'.

• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.4
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• pp.3991-4000
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• 1975

It is the aim of this study to investigate the influence of the factors in the sprayer nozzle for the travelling distance and to get nozzle design data in relation to the nozz1e with and without swirl plate. The factors of sprayer nozzle are composed of the spraying pressure, the helical angle of swirl plate, the helical groove depth of swirl plate, the distance of vortex chamber the slope of nozz1e cap, the curvature of nozzle cap and the hole diameter of nozz1e cap. The travelling distance and the size of sprayed particle are experimeted indoors by the factorial arrange-ment according to the 5 each level of the above factors. The results of this stupy are summarized as follows; 1. In the nozzle with swirl p1ate there were remarkable significance among factors each other, while without swirl plate were no significance. 2. The helical angle and groove depth in the nozzle with swirl plate were the highest effective factors. The effect of helical angle was very remarked in the quadratic curve with minium value. 3. The correlation betweenthe travelling distance and the sprayed particle size was no high and under 250 micron in the case with swirl plate, and there was higher correlation in the case without swirl plate. 4. The new ideal development of the swirl plate using of the most effective helical angle and groove depth will probably show the possiblities to make effective travelling distance over 8 meters and more over and to make average particle diameter under 300 micron.

• Journal of Welding and Joining
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• v.23 no.4
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• pp.73-80
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• 2005

Arc blow being occurred by Electro-Magnetic force(EMF) during the electric arc welding prevents the formation of a sound weldment. In this study, the effects of arc position, groove size, tack weld and base plate on the EMF in a butt-joint welding of mild steel plate are analyzed by a computer simulation based on the finite element method. The EMF can be numerically identified to be caused by a difference of the magnetic flux-density between ahead of and behind the arc in case that the workpiece locates asymmetrically around the uc. When there exists an air gap of groove ahead of the arc in the welding direction, the similar magnetic force has been producted regardless of the arc position and the gap size. The tack weld alleviates the magnetic force to about one fourth at the finish end of the workpiece. The magnetic force can be also significantly reduced with the base plate to about one fifth at the start end of the workpiece containing a tack weld.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.794-798
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• 2004

This paper is analysis of stiffened opening thick plate on foundation. This paper has the object of investigating natural frequencies of opening thick plates on Pasternak foundation by means of finite element method and providing Kinematic design data for mat of building structures. In this paper, vibration analysis of rectangular opening thick plate is done by use of Serendipity finite element with 8 nodes by considering shearing strain of plate. And vibration analysis of stiffener is done by used of Timoshenko beam-column element wit 3 nodes. It is shown that natural frequencies depend on not only Winkler foundation parameter but also shear foundation parameter, opening position, opening size, stiffener size.

• Advances in aircraft and spacecraft science
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• v.7 no.2
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• pp.169-186
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• 2020

Based upon differential quadrature method (DQM) and nonlocal strain gradient theory (NSGT), mechanical-hygro-thermal vibrational analyzes of shear deformable porous functionally graded (FG) nanoplate on visco-elastic medium has been performed. The presented formulation incorporates two scale factors for examining vibrational behaviors of nano-dimension plates more accurately. The material properties for FG plate are porosity-dependent and defined employing a modified power-law form. It is supposed that the nano-size plate is exposed to hygro-thermal and variable compressive mechanical loadings. The governing equations achieved by Hamilton's principle are solved implementing DQM. Presented results indicate the prominence of moisture/temperature variation, damping factor, material gradient index, nonlocal coefficient, strain gradient coefficient and porosities on vibrational frequencies of FG nano-size plate.