• 전자공학회논문지C
• /
• 제34C권9호
• /
• pp.77-83
• /
• 1997

Based on the curve segment grouping, an efficient recognition of round objects form partially occuluded round boundaries is proposed. Curve segments are extracted from an image using a criterion based on the intra-segment curvature and local contrast. During the curve segment extraction the boundaries of pratially occluding and occuluded objects are segmented to different curve segments. The extracted segments of constant intra-segment curvature are grouped to different curve segments. The extracted segments of constant intra-segment curvature are grouped nto a round boundary by the proposed grouping algorithm using inter-segment curvature which gives the relatinships among the curve segments of the same round boundary. The 1st and the 2nd order moments are used for the parameter estimation of the best fitted ellipse with round boundary, and then recognition is perfomed based on the estimated parameters. The proposed scheme processes in segment unit and is more efficient in computational complexity and memory requirements those that of the conventional scheme which processed in pixel units. Experimental results show that the proposed technique is very efficient in recognizing the round object sfrom the real images with apples and pumpkins.

• 한국정밀공학회지
• /
• 제21권12호
• /
• pp.37-43
• /
• 2004

The performance of magnetic abrasive finishing fur surface is evaluated by the characteristic curve. The characteristic curve is generated by experiment in surface finishing. For experiment, new magnetic inductor is designed and manufactured. 15 kinds of powders are provided to find the relationship between powder characteristic and finishing performance. As powder, Fe-TiC. Polymer-TiC and Fe-NbC are used with different size. The size of abrasives and location are also important factor for the performance. From characteristic curve, two index are obtained, which specify the initial finishing performance and endurance of finishing performance. It is proved that the performance index can be applied to select proper powder for efficient deburring. It is shown that the characteristic curve can be used as good tools for evaluating powder performance in surface finishing and deburring.

• 대한수학회지
• /
• 제57권1호
• /
• pp.145-169
• /
• 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 ${\mathfrak{C}}$.

• 한국수학교육학회지시리즈B:순수및응용수학
• /
• 제23권3호
• /
• pp.309-317
• /
• 2016

As a generalization of an inflection point, we consider a point P on a smooth plane curve C of degree m at which another curve C' of degree n meets C with high intersection multiplicity. Especially, we deal with the existence of two curves of degree m and n meeting at the unique point.

• 한국식품저장유통학회지
• /
• 제4권2호
• /
• pp.163-171
• /
• 1997

This study was undertaken to investigate changes m curve angle of Chinese cabbage blade during salting at various concentration(10, 15, 20, 25%) of salt to evaluated salting degree by curve angle during salting at 20$^{\circ}C$. Salt concentration of brine, the amount of water elution, salt penetration of the tissue(salt concentration of Chinese cabbage), weight loss and texture were investigated. Correlation relation between the above factors and curve angle were determined. The curve angles by method of holding the edge of the Chinese cabbage blade was measured. The curve angles of the mesophyll were proportional to salting time and salt concentration, but slope of line equation showed higher than that of mid-rib. The ideal method of salting evaluation by curve angle was MCA-MRC (the measuring curve angle of mid-rib C) at each concentration of salt. The results of curve angle when reached 3% salt of Chinese cabbage tissue calculated by MCA-MRC at 10, 15, 20 and 25% salting were 57$^{\circ}$, 43$^{\circ}$, 36$^{\circ}$, and 33$^{\circ}$, respectively. And salting times calculated by the same conditions were 19, 12.5, 9.1 and 4.4hours, respectively.

• 한방재활의학과학회지
• /
• 제25권4호
• /
• pp.83-92
• /
• 2015

Objectives To measure and analyze the curvature of the cervical spine for university students. Methods This study carried out on 132 students. The cervical spine curvature was measured by six measuring methods. The type and numeric value of cervical spine curvature was analyzed by Angle of cervical curve (C1~C7), Angle of cervical curve (C2~C7), Jackson's angle, Ishihara Index, Depth of cervical curve and Method of Jochumsen. Cervical spine curvatures between male and female are compared by Mann-Whitney test. Rate of type of cervical curvature between male and female are compared by linear by linear association. Results 1. The average of angle of cervical curve (C1~C7) is $33.78{\pm}9.85^{\circ}$, angle of cervical curve (C2~C7) is $10.28{\pm}8.12^{\circ}$. The average of Jackson's angle is $14.02{\pm}10.01^{\circ}$, average of Ishihara Index is $8.46{\pm}10.58%$. The average of Depth of cervical curve is $5.15{\pm}4.72mm$ and average of Method of Jochumsen is $0.94{\pm}3.83mm$. 2. More than half of student's cervical curvature showed hypolordosis except Ishihara index. 3. There was significant difference in numeric value of cervical curvature between male and female both groups in terms of Ishihara index. 4. There were insignificant differences between male and female in terms of type of cervical curvature. Conclusions According to above results, we found out average of student's cervical curve. And the results suggest that most of the student's cervical curvature decrease.

• 한국세라믹학회지
• /
• 제37권4호
• /
• pp.368-375
• /
• 2000

Fracture toughness of particulate composites of Al2O3/SiC, Al2O3/ZrO2 and Al2O3/ZrO2/SiC was analysed theoretically. According to the suggested particle bridging model for obtaining the R-curve height, the crack extension resistance for the long crack was linearly proportional to the residual calmping stress at the interface between the second phase and the matrix. It was also a function of the particle size and the content. It was confirmed that the rising R-curve behavior of Al2O3 containing 30 vol% SiC particles of 3${\mu}{\textrm}{m}$ was owing to the strong crack bridging by SiC particles. For Al2O3/ZrO2/SiC composites, the tensional stress from the 3${\mu}{\textrm}{m}$ SiC particles was large enough to activate the spontaneous transformation of the ZrO2. The crack extension resistance due to the particle bridging mechanism did not seem to be affected much by the coupled toughening, but its resultant toughness increase could be significantly smaller due to the dependency on the matrix toughness.

• 농업과학연구
• /
• 제27권1호
• /
• pp.39-47
• /
• 2000

본 연구는 연약지반의 심도가 갚으면서 압밀침하량이 큰 지역에서 연직드레인 공법에 의하여 개량한 지반의 침하거동을 파악하고, 현장계측결과를 기초로 기존의 최종침하량의 예측방법과 현장계측치로부터 역산한 압축지수와 압밀계수의 범위를 실내시험과 비교분석 한 것으로 본 연구 대상지역에서 얻은 결과를 요약하면 다음과 같다. 1. 최종침하량 예측방법에 의하여 구한 최종예상침하량은 쌍곡선 방법이 가장 크고, Asaoka 방법과 Curve fitting 방법은 유사하게 나타났으며, 타입간격이 좁을 경우에는 교란영향을 고려한 설계가 검토되어야 할 것으로 판단된다. 2. 실측압밀도($U_m$)와 설계압밀도($U_t$)와의 관계는 쌍곡선 방법에서 $U_m$=(0.88~1.03)$U_t$으로 약간 작게 나타났고, Asaoka 방법은 $U_m$=(1.07~1.20)$U_t$, Curve fitting 방법은 $U_m$=(1.13~1.17)$U_t$으로 유사하게 나타났다. 3. 실내압축지수($V_{cclab}$)와 현장압축지수($Cc_{field}$)와의 관계는 쌍곡선 방법에서는 $Cc_{field}$=(1.26~1.45)$V_{cclab}$, Asaoka 방법에서는 $Cc_{field}$=(1.08~1.15)$V_{cclab}$, Curve fitting 방법에서는 $Cc_{field}$=(1.04~1.21)$V_{cclab}$의 범위로 쌍곡선방법에서는 약간 크게 나타났고, Asaoka와 Curve fitting 방법은 거의 동일한 값을 나타냈다. 4. 현장계측치로부터 역산한 현장압밀계수 ($C_h$)와 실내시험에서 구한 수직압밀계수($C_v$)와의 비는 ($C_h$/$C_v$) 쌍곡선방법에서는 0.7~0.9. Asaoka 방법에서는 0.9~1.5. Curve fitting 방법에서는 2.4~3.0의 범위로 나타났다. 5. 현장압밀계수는 방치기간이 경과함에 따라서 점차로 감소하는 경향을 나타내므로 압밀이 완료되었을 때에 최종침하량 예측방법에 의하여 재분석한 후 정확한 압밀계수를 산정하는 것이 합리적이라고 판단된다.

• 한국해양공학회지
• /
• 제10권2호
• /
• pp.98-105
• /
• 1996

A method is proposed to evaluate the elastic-plastic fracture resistance curve only with load displacement records without the crack length measurement in CT specimen. This method is based on the idea that the effect of plastic deformation and the crack growth can be measured only by using a load-displacement record. If we know the reference-load curve representing the hardening of specimen, then the crack extension can be calculated by the elastic compliance determined from the load ratio. The results of this proposed method were compared to those of the elastic-plastic fracture resistance curve for the ASTM standard unloading compliance method. The experimental results for two kinds of ductile materials showed that the proposed method well simulates the material J-R curves. This method is currently applied for CT specimens. but it can be extended to the other specimen geometries.

• 대한수학회논문집
• /
• 제12권3호
• /
• pp.539-541
• /
• 1997

Let X be a smooth projective threefold. Let C be a smooth projective curve and let $f : X \to C$ be a fiber space with connected fiber S. Assume that $q_1(S) = 0$. Then we have $-X(O_C)X(O_S) \leq -X(O_X)$.