• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.429-430
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• 2006

To estimate the fatigue life of flange-shaft assembly, fatigue test for flange material and bending fatigue test for flange-shaft assembly were conducted. Also, finite element analysis for flange-shaft assembly was conducted. Then, we have changed the obtained P-N curve to S-N curve using the finite element analysis results which were stress values at the location of fracture. The S-N curve of flange material itself was almost consistent with that of flange-shaft assembly, so it seems that the fatigue life of flange-shaft assembly could be estimated by using S-N curve for flange material and the stress at the location of fracture calculated by finite element methods.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.217-222
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• 2001

For the life evaluating of notched members, it is the best way that performing the real fatigue test of structure containing notch. But this method required generally much times and costs to evaluate fatigue life. So, generally we use the modified S-N curve or several methods to predict fatigue life. In this study, crack initiation life was evaluated by fatigue testing the SAE keyhole specimen and smooth specimen made of Al 7075-T6 alloys using the constant load then obtained S-N curve of smooth specimen and P-N curve of SAE keyhole specimen. And, fatigue lives of keyhole specimen are predicted using some life prediction methods (Nominal range I method, Nominal range II method, FEM analysis) for investigating experimented results, and that were compared with experimental data. Predicted fatigue lives by FEM analysis were corresponded with experimental data between 1/3times and 3times on the whole, and predicted fatigue lives using modified S-N curve (Nominal range I method, Nominal range II method) were nonconservative compared with that of FEM analysis.

• 정보보호학회지
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• 제3권1호
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• pp.86-90
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• 1993

Finite field GF$(2^n)5에서 정의된 elliptic curve가 있을때 그 curve위의 어떤 point p를 k배하는 연산은 암호론에서 매우 자주 쓰여진다. 이때 optimal normal bases를 이용하여 GF$(2^n)의 element를 표현하고, 또 elliptic curve를 선택할 때 animalous curve가 되도록 한다면, 기존이 방법 보다 매우 빠르게 k P를 구할 수 있다.

• 대한기계학회논문집A
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• 제39권12호
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• pp.1207-1212
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• 2015

진동리퍼는 암반의 파쇄와 리핑 작업을 동시에 하기 위해서 개발된 장비이며 기존의 암반 파쇄용 유압 브레이커와 작동 원리가 다르다 진동리퍼의 기진력을 투스로 전달하는 기어박스-생크 용접부는 매우 중요한 부분이며 진동리퍼의 기계적 건전성의 예측이 필수적이다. 본 연구는 생크소재 및 용접재료의 변화에 따른 접부의 피로수명 예측을 목적으로 하고 있다. 생크의 재료는 Hadox-hituf, AR 400을 사용하였고 접금속은 CSF-71T, CSF-81T를 사용하였다. 피로시험은 응력비 R=0에서 각 재료조건에 대해서 수행하였다. P-S-N 선도는 JSME-S002 규정에 맞춰 파괴확률 10%, 50%, 90%에 대해서 나타냈으며 수명 예측 식을 도출하였다.

• 호남수학학술지
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• 제33권2호
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• pp.153-161
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• 2011

Greg([Greg]) considered that $$N_k= \sum\limits_{i=1}^k(-1)^{i+1}P_{i,k}(p)N_1^i$$ where the $P_{i,k}$'s were polynomials with positive integer coefficients. In this paper, we will give the equations for $\sum\limits{P_{i,k}$ modulo 3. Using this, if we send a information for elliptic curve to sender, we can make a new checksum method for Manchester coding in IEEE 802.3 or IEEE 802.4.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.154-159
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• 2004

In this study, in order to perform more efficiently reliability design and integrity assessment of structural members, the relational database management program on the engineering plastics was constructed. This program contained 476 grades for 14 kinds of the engineering plastics and was developed using MS-access and MS-visualbasic. This program consists of 3 modules; search condition, probabilistic characteristics of material property, evaluation of P-S-N curve. We perform fatigue test for probabilistic durability analysis and this results input the database program to estimate P-S-N.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.201-206
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• 2003

This study is test for STS304 specimen using bending and torsion state. Rounded specimen and notched specimen including fracture surface investigation was comparatively experimented, fatigue life according to degree of surface finishing was examined. Fatigue fracture probability of notched canilever specimens were predicted by P-S-N curve, median rank and Weibull distribution. And at the relation with the rotational speed and stress, the fatigue life of the test specimen was higher at high speed than low speed If summarize STS304 torsion result of fatigue test, is as following. Fatigue life prediction was available by Weibull statistics distribution, and 50% breakdown probability correlation equation was appeared as following.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.199-204
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• 2001

Big accidents of flyings, vessel, subways, gas equipments, buildings and bridge happens frenquently. Therefore many people are suffering harm of property. The destruction cause of macaine components is almost accused by fatigue. This study is test for STS304 specimen using pure and cantilever bending state. Rounded specimen and notched specimen including fracture surface investigation was comparatively experimented, fatigue life according to degree of surface finishing was examined. Fatigue fracture probability of notched canilever specimens were predicted by P-S-N curve, median rank and Weibull distribution. And at the relation with the rotational speed and stress, the fatigue life of the test specimen was higher at high speed than low speed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.272-277
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• 2001

In order to evaluate variation of fatigue data of the LP steam turbine blade steel, it is important to estimate P - S - N curves to accurately define the probability distributions. In this study, new procedure is introduced to determine the expression of P - S - N curves. For this purpose, 3-parameter Weibull distribution was found to be most appropriate among assumed distributions when the probability distributions of the fatigue life were examined by the proposed analysis. Furthermore, parameter estimation for P - S - N curves was performed using various optimization to maximize the correlation coefficient. As a result of this, sequential linear programing method is used for estimation of P - S - N curves.

• 대한수학회지
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• 제33권2호
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• pp.367-379
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• 1996

Let $V = {(z, y) : f(z, y) = z^n + Ay^\alpha z^p + y^\beta z^q + y^k = 0}$ and $W = {(z, y) : g(z, y) = z^n + By^\gamma z^s + y^\delta z^t + y^k = 0}$ be germs of analytic irreducible subvarieties of a polydisc near the origin in $C^2$ with n < k and (n, k) = 1 where A and B are complex numbers. Assume that V and W are topologically equivalent near the origin.