• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.48 no.3
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• pp.167-173
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• 2022

Objectives: The purpose of this study was to estimate the minimal clinically important difference (MCID) of mouth opening (MO) and patient satisfaction in surgically treated oral submucous fibrosis (OSMF) patients. Materials and Methods: The status of MO was collected preoperatively (T0), postoperatively at 3 months (T1), and at a minimum of 6 months postoperatively (T2). MCID was determined through the anchor-based approach with the change difference method, mean change method, and receiver operator characteristic curve (ROC) method. Results: In this study, 35 patients enrolled and completed postoperative follow-up (T2) averaging a duration of 18.1 months. At T1, using the change difference method, MO was 14.89 mm and the ROC curve exhibited a 11.5 gain in MO (sensitivity 81.8% and specificity 100%, area under the curve [AUC] of 0.902) and was classified as MCID as reported by patients. At T2, MCID of MO was 9.75 mm using the change difference method and 11.75 mm by the mean change method. The ROC curve revealed that the MCID of MO at T2 was 10.5 mm with 73.9% sensitivity and 83.3% specificity (AUC of 0.873). The kappa value was 0.91, confirming reliability of the data. Conclusion: This study demonstrated MCID values that indicate the clinical relevance of surgical treatment of OSMF if the minimum possible gain in MO is approximately 10 mm.

• Journal of the Korean Society for Railway
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• v.5 no.4
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• pp.244-252
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• 2002

We must notice ground movement by excavation for reasonable tunnel designs. The convergence confinement method is an attempt to evaluate tunnel stability conditions by means of a mathematical model and a ground response curve. In this study, the convergence confinement method by numerical model was examined. This method don't need the basic assumptions for a mathematical model of circular tunnel shape, and hydrostatic in situ stress. Also modified ground response curve that is calculated after installing the support, is suggested, which informs us the ground movement mechanism. The ground response curve and the support reaction curve are mutually dependent. Especially the support reaction curve depends upon the ground response curve. The mechanism of tunnel must be analyzed by the interaction between support and ground. Consequently the stability of tunnel must be qualitatively investigated by a ground response curve and quantitatively adjudged by a numerical analysis for the reasonable design of tunnel.

• Korean Journal of Agricultural Science
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• v.27 no.1
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• pp.39-47
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• 2000

A large scale field test of prefabricated vertical drains is performed to analyze the effect of parameters of the very soft clay at a test site. Compression index and the coefficient of horizontal consolidation obtained by back-analysis from the settlement data were compared with those obtained by means of laboratory tests. The Hyperbolic, Asaoka's and The Curve fitting methods are used to estimate final settlements and coefficients of consolidation. 1. Final settlement predicted with the Hyperbolic method was the largest, and the settlements predicted with the Asaoka's and the Curve fitting methods were nearly the same range, and it was concluded that smear effect has to be considered on design in the case that spacing of drains is small 2. The relationships of the measured consolidation ratio (Urn) and the designed consolidation ratio($U_t$) were showed as $U_m$ = (1.13~1.17)$U_t$, $U_m$ = (1.07~1.20)$U_t$, $U_m$ = (1.13~1.17)$U_t$ on the Hyperbolic, Asaoka's and the Curve fitting methods, respectively. The relations on the Asaoka's and the Curve fitting methods were nearly the same range. 3. The relationships of the field compression index($C_{cfield}$) and virgin compression index($V_{cclab}$) were showed as $C_{cfield}$ = (1.26~1.45)$V_{cclab}$, $C_{cfield}$ = (1.08~1.15) $V_{cclab}$, $C_{cfield}$ = (1.04~1.21)$V_{cclab}$, on the Hyperbolic, Asaoka's and the Curve fitting methods, respectively. 4. The ratio ($C_h/C_v$) of the coefficient of vertical consolidation and the coefficient of horizontal consolidation that is obtained by back-analysis from the settlement data was $C_h$=(0.7~0.9)$C_v$, $C_h$=(0.9~1.5)$C_v$, $C_h$=(2.4~3.0)$C_v$ on the Hyperbolic, Asaoka's and the Curve fitting methods, respectively. 5. It was concluded that the exact consolidation coefficient must be determined after the final settlement is predicted again when the consolidation is finished, because the field consolidation coefficient is decreased as the time allowed to be alone is increased.

• Journal of the Korean Society of Costume
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• v.50
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• pp.5-22
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• 2000

The study on the past costume should be done first for the creation of new style of fashion. That is one of the reasons why we have to annalize characteristic style in each period. Before the latter of nineteenth century one must have made the costume by draping design. Because the complicated clothes can be expressed by draping deign think that the subject draping design is even more important than other subject. But there haven't been the studies that analyzed the pattern of Art Nouveau style by draping design in Korea. Art Nouveau style is a certain one that was relatively more changeable than the ones of other periods. The purpose of this study is the analysis about the patterns of hourglass and S-curve style which represented the Art Nouveau style. The results of the study summarized as follows. 1. Bodice pattern : In the front Hourglass silhouette has the princess line for fitting bodice while S-curve silhouette has the wide midriff due to the blousing. There is the yoke in S-curve one. In the pattern of back bodice we can't see the much differences but Hourglass silhouette is used the princess line like the front one while S-curve is made use of the waist darts for fitting back. 2. Sleeve pattern : Hourglass silhouette is made of two pieces the upper part and lower part besides S-curve is consisted of one pieces. The former has the big upper part in order to the emphasis of the shoulder and the tight lower part. The latter is the tight sleeve that similar to the basic sleeve pattern at present. 3. Skirt pattern: There is partially a gored line in the front skirt in Hourglass silhouette however S-curve silhouette is consisted of the six pieces gored skirt. At this part we can also see the fact that s-curve is more complicated than Hourglass silhouette. 4. Others: Wecan find out the differences between Hourglass and S-curve pattern easily at the parts of the collar flounce wing and so on. Summing up, the patterns of S-curve style are more expanded than those of Hourgalss style for the most part.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1185-1188
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• 2007

The address discharge characteristics by the various scan-low and common-bias voltages are investigated based on measured address discharge time lags and $V_t$ close-curve analysis. The scan-low voltages are changed under the same voltage difference between the X and Y electrodes during an address period. As the voltage difference between the scan and address electrodes is increased during an address period, the address discharge time lag is shortened but the background luminance is increased. It is found that the improved address discharge characteristics is caused by the effect of the higher external applied voltage during an address period than the accumulated wall charges during a reset period and the high background luminance can be prevented by applying an address-bias voltage during a rising-ramp period and low reset voltage.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.100-105
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• 2003

With the recent development of machining technology, high speed machining process is widely used for-the mold and difficult-to -cut-materials machining since it allows achieving high productivity and surface quality. However, during the high speed machining process, high cutting speed and feed rate can cause abrupt tool life decrease due to rapid rising of the cutting tool temperature. Such situation may cause increase of machining cost. Thus, in this study, developed optimization algorithm is applied to determine optimal machining variables for multiple high speed machining. The R-T characteristic curve for machining economics problems with a linear-lorarithmic tool life model is determined by applying sensitivity analysis. finally, a series of high speed machining experiments are performed to determine the desired optimal machining variables, and the results are analyzed.

• Journal of the Korean Mathematical Society
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• v.57 no.1
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• pp.145-169
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• 2020

Let k be a field of characteristic 0. Let ${\mathfrak{C}}=Spec(k[x,y]/{\langle}f{\rangle})$ be a weighted homogeneous plane curve singularity with tangent space ${\pi}_{\mathfrak{C}}:T_{{\mathfrak{C}}/k}{\rightarrow}{\mathfrak{C}$. In this article, we study, from a computational point of view, the Zariski closure ${\mathfrak{G}}({\mathfrak{C}})$ of the set of the 1-jets on ${\mathfrak{C}}$ which define formal solutions (in F[[t]]² for field extensions F of k) of the equation f = 0. We produce Groebner bases of the ideal ${\mathcal{N}}_1({\mathfrak{C}})$ defining ${\mathfrak{G}}({\mathfrak{C}})$ as a reduced closed subscheme of $T_{{\mathfrak{C}}/k}$ and obtain applications in terms of logarithmic differential operators (in the plane) along ${\mathfrak{C}}$.

• Structural Engineering and Mechanics
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• v.53 no.6
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• pp.1271-1286
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• 2015

Recently, US NRC revised fracture toughness requirements as 10CFR50.61a to reduce the conservatism of 10CFR50.61. However, unlike previous studies relating to the initial regulation, structural integrity evaluations based on the alternative regulation are not sufficient. In the present study, PTS and P-T limit curve evaluations were carried out by using both regulations and resulting data were compared. With regard to the PTS evaluation, the results obtained from the alternative requirements were satisfied with the criterion whereas those obtained from the initial requirements did not meet the criterion. Also, with regard to the P-T limit curve evaluation, operating margin by 10CFR50.61a was greater than that by 10CFR50.61.

• Computers and Concrete
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• v.11 no.5
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• pp.399-410
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• 2013

A nonlinear finite element analysis of R/C hybrid deep T-beam with web opening subjected to pure torsion is presented. Hexahedral 8-nodes and space truss element were used for modeling concrete and reinforcement. The reinforcement was assumed perfectly bonded to the corresponding nodes of the concrete element. The constitutive relations for concrete and reinforcement are based on the modified field theory and elastic perfectly plastic. The smear crack approach was adopted for modeling the crack. The torque-twist angle relationship curve based on the finite element analysis was compared to the experimental results. The comparison shows that the curve of torque-twist angle predicted by the nonlinear finite element analysis is linear before cracking and close to the experimental result. After cracking, the curve becomes nonlinear and stiffer compared to the experimental result.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.7
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• pp.99-107
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• 1997

An algorithm is developed to find optimal machining parameters for multiple machining environments. The cutting rate-tool life (R-T) characteristic curve presents the general loci of optima and is useful for the flexible machining operations planning. The R-T characteristic curve for the machining economics prob- lems with linear-logarithmic tool lofe model may be determined by applying sensitivity analysis to log-dual problems. Three cases of the change of machining environments are considered. An end milling example is constructed to illustrate the algorithm.