• 한국경제지리학회지
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• 제25권4호
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• pp.583-599
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• 2022

OECD는 저밀도 경제 논의에서 저밀도 지역의 경제 성장이 금융위기 이 후 회원국들의 국가 경제 회복을 견인했음을 밝혔다. 이 연구에서는 저밀도 경제 논의에 기초하여, 우리나라 주변부 지역의 산업 성장 추이와 공간적 특성을 살펴보았다. 그 결과 농림어업 등 주변부 지역에 입지하는 전통적인 산업 외에도 국가적으로 성장하는 제조업, 서비스업 부문의 성장이 주변부 지역에서 나타났다. 기존 지역 산업의 다각화와 전환을 통해 새롭게 산업이 집적하는 지역도 출현했다. 주변부 지역에 입지한 기업들은 지역의 불리함을 극복하기 위해 외부 지역, 주로 광역권 단위의 공간 연계를 형성하는 것으로 확인되었다. 주변부 지역의 새로운 산업 출현은 농어촌, 인구감소 지역 등 낙후 지역의 자생적 발전 가능성을 보여준다. 이러한 결과를 토대로 주변부 지역의 산업 육성을 위해, 기존 지역산업의 다각화를 지원하기 위한 정책 추진, 유연한 공간 단위 설정, 정책 부문 간 연계 등의 시사점을 도출하였다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 추계학술대회 논문집
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• pp.232-237
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• 2001

The evaluation of specimen thickness effect of fatigue crack growth life by the simulation of probabilistic fatigue crack growth is presented. In this paper, the material resistance to fatigue crack growth is treated as a spatial stochastic process, which varies randomly on the crack surface. Using the previous experimental data, the non-Gaussian(eventually Weibull, in this report) random fields simulation method is applied. This method is useful to estimate the probability distribution of fatigue crack growth life and the variability due to specimen thickness by simulating material resistance to fatigue crack growth along a crack path.

• 한국해양공학회지
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• 제13권2호통권32호
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• pp.58-65
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• 1999

The effect of specimen thickness on fatigue crack growth rate was studied. The objective of the present study is to investigate the effect of specimen thickness on the fatigue crack growth behavior at various stress intensity factor ranges and also the variation of material restance to fatigue crack growth. The fatigue crack growth resistance was treated as a spatial stochastic process, which varies randomly on the crack path, Compact tension specimens with a LT orientation for structural steel were used. All testing was done at a constant stress intensity level. The experimental data were analyzed for the size effect to determine the Weibull distributions of the material resistance.

• 한국재료학회지
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• 제13권11호
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• pp.756-760
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• 2003

Two dimensional computer simulations were conducted on percolative structure in which second phases with various short diameter were arranged in matrix phase. In case of prohibiting the overlap among the second phases, the maximum area fraction of second phase arranged in matrix was increased with higher short diameter. In case of allowing the overlap among the second phases, the critical area fraction was increased with higher short diameter and the total number of distributed second phase was decreased. This results represented that thickness variation of short diameter by grain growth on the production processes affect significantly forming the completion path.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1525-1526
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• 2006

Electrical current always travels through the minimum resistance path. In this paper, we are studied on the direction and formation of carbonized conductive path according to surface leakage between electrodes. The analysis of characteristics of the arc discharge as surface is broken down between exposed live parts. Using the HSIS(high speed imaging system, 100,000fps, redlake ltd., USA), it took photographs by arc growth mechanism occurred in on/off surge, ground fault and discharge between electrodes. Therefore, it recommended for results of technology development and application such as theoretic verification of an arc direction and economic security according to a technology about connecting arc generation in surfaces of insulators. Hereafter, it expected effects that application of energy utility technology through the arc control.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.807-810
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• 2001

Fatigue crack growth tests were carried out using high manganese cast steel under constant amplitude loading. Crystal grain size of the material is about 1000$\mu\textrm{m}$. For this material, the fatigue crack growth mechanism of high manganese steel was clarified from results such as observation of crack growth path and fracture surface. $\Delta$$K_{th}$ is about 8MPa$\surd$m which is quiet large as compared to the general structural steels and the crack growth rate is lower than the general structural steels especilly in the low $\Delta$K regsion. The reason of this behavior is crack closure due to fracture surface roughness.

• KDI Journal of Economic Policy
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• 제34권4호
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• pp.1-26
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• 2012

한국 및 여타 국가들의 온실가스 배출 관련 정책들은 기본적으로 배출 전망치를 바탕으로 수립되는바, 노동생산성이 높은 증가세를 보이는 부문에서 낮은 증가세를 보이는 부문으로 진행되는 구조적 변화-산업별 노동생산성 증가, 산업 전반의 배출 저감, 인구 증가를 고려한-의 예상경로가 핵심 요소가 된다. 따라서 구조적 변화의 원인을 모델화하는 작업은 배출량의 정확한 예측을 위해서 중요하다. 본 보고서는 한국경제 데이터를 활용하여 구조적 변화와 녹색성장 모델을 수립 및 평가함으로써 한국과 국제사회의 온실가스 담론을 위한 정책 함의성을 도출한다.

• 대한기계학회논문집A
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• 제23권7호
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• pp.1139-1146
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• 1999

Reliability analysis of structures based on fracture mechanics requires knowledge on statistical characteristics of the parameter C and m in the fatigue crack growth law, $da/dN=C({\Delta}K)^m$. The purpose of the present study is to investigate if it is possible to predict fatigue crack growth rate by only the fluctuation of the parameter C. In this study, Paris-Erdogan law is adopted, where the author treat the parameter C as random and m as constant. The fluctuation of crack growth rate is assumed only due to the parameter C. The growth resistance coefficient of material to fatigue crack growth (Z=1/C) was treated as a spatial stochastic process, which varies randomly on the crack path. The theoretical crack growth rates at various stress intensity factor range are discussed. Constant ${\Delta}K$ fatigue crack growth tests were performed on the structural steel, SM45C. The experimental data were analyzed to determine the autocorrelation function and Weibull distributions of the fatigue crack growth resistance. And also, the effect of the parameter m of Paris' law due to variation of fatigue crack growth resistance was discussed.

• 노동경제논집
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• 제26권3호
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• pp.49-75
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• 2003

본고는 생산현장에서의 인적자본 축적, 즉 근로자의 숙련형성에 영향을 주는 요인들을 실증적으로 찾아보고, 형성된 숙련이 생산성 향상에 기여하고 있는 것을 확인한다. 먼저 숙련형성의 유형은 '단순/견습근로자 < 단능근로자 < 다능근로자'의 직렬적 순서이다. 제품수요의 급변성과 비정상적인 상황 발생이라는 외부적 내부적 불확실성이 클수록 다능화가 활발하게 이루어지고 있으며, 선배 동료 근로자와의 상호학습, 근로자의 의사결정 참여, 직무 순환 등의 인적자원관리 관행들도 다능화를 촉진한다. 이러한 발견들로부터 생산 현장에서의 숙련형성은 다능화로 대표될 수 있다고 판단된다. 기업의 노동생산성 성장률을 기업의 성장률이라고 하면, 불확실성과 인적자원관리 관행들은 다능화를 통해서 기업의 성장에 영향을 준다. 구체적으로 기업의 다능화 비율이 0.1만큼 올라감에 따라 노동생산성 성장률이 0.019만큼 증가한다. 이것은 또한 다능화가 인적자원관리 관행들에 영향을 받아 형성되는 인적자본 축적의 한 결과라는 주장에 대한 근거가 될 수 있다.

• 한국정밀공학회지
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• 제15권1호
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• pp.78-86
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• 1998

This paper presents a numerical method of the minimum-time trajectory planning for a robot manipulator amid obstacles. Each joint displacement is represented by the linear combination of the finite-term quintic B-splines which are the known functions of the path parameter. The time is represented by the linear function of the same path parameter. Since the geometric path is not fixed and the time is linear to the path parameter, the coefficients of the splines and the time-scale factor span a finite-dimensional vector space, a point in which uniquely represents the manipulator motion. The displacement, the velocity and the acceleration conditions at the starting and the goal positions are transformed into the linear equality constraints on the coefficients of the splines, which reduce the dimension of the vector space. The optimization is performed in the reduced vector space using nonlinear programming. The total moving time is the main performance index which should be minimized. The constraints on the actuator forces and that of the obstacle-avoidance, together with sufficiently large weighting coefficients, are included in the augmented performance index. In the numerical implementation, the minimum-time motion is obtained for a planar 3-1ink manipulator amid several rectangular obstacles without simplifying any dynamic or geometric models.