쏘일네일링 시스템의 최적설계기법에 관한 연구

黃正淳,黃正奎 弘益大學校 科學技術硏究所 1998 科學技術硏究論文集 Vol.9 No.1

The 'The Optimum Design of Soil-Naiing System' aims to minimize the construction cost. The Construction cost is affected by many factors like resources, utilities, construction duration etc. However, the total length of the nail(total length of boared hole) is one of the most important factor for the cost of soil-nailing system. So, the total length of nail is chosen as a object function for this optimum problem. In this study, an analytical approach to develop the optimum design technique of soil-nailing system was made. For this purpose the Genetic Algorithm which adopted the Neural Network was used for searching algorithm. Also, the nailed-soil wall displacements expected during the construction stage were taken into account. The nailed-soil wall displacements were predicted by using the Neural Network. In addition, the systemetric disign method of soil-nailing facing element was proposed. Finally, Based on the developed optimum design technique of soil-nailing system, the estimation of importances of various design parameters was made in detail. Also, the optimum design technique was applied in a practical case for the comparison the suggested optimum design method and the ordinary design method. By the comparison the optimum shape of nailing system was proposed for the particular case.

개별요소법에 의한 보강토옹벽의 안정해석

황정규,김화주 弘益大學校 科學技術硏究所 1996 科學技術硏究論文集 Vol.7 No.1

The use of geosynthetics as a reinforcing element for reinforced earth retaining structures has been recently increased in view of its low cost, light weight and good durability. With fabrics, however, large strains may frequently be induced, it is essential, therefore, to assess the strains likely to be induced. In this paper an analytical procedure based on Chang's discrete element method for stability analysis of reinforced soil retaining wall is presented to predict displacements of geosynthetics. For the stability analysis of geosynthetic reinforced soil retaining wall, nonlinear behavior of the reinforcement is simulated by using hyperbolic model. Furthermore, the maximum reinforcement tension in any reinforcement layer has been estimated by modifying the method proposed by Duncan et al.(1980,1986), Ehrlich & Mitchell(1994)

말뚝의 動的 支持力 및 杭打應力에 관한 硏究

黃正奎 弘益大學校 1989 弘大論叢 Vol.21 No.2

This paper proposes practical method which can provides field engineers with reliable and convenient analytical procedures for the determination of load carrying capacity of piles and for the prediction of driving stresses along the full length of pile. The comparison indicates the newly proposed equations are as reliable as any other formula of this kind which have been known highly reliable, and also as the numerical method by the wave equation.

R. Cantillon, F. Quesnay 및 A. Smith의 이윤개념에 대한 비교 연구

황규선,정향교 釜山 大學校 經營 經濟 硏究所 1995 經營 經濟 硏究 Vol.14 No.1

본 논문에서는 스미스 이전 시대에 논의되었던 이윤의 개념, 그 중에서도 스미스의 이론 형성에 많은 영향을 미친 깡띠옹과 케네의 이론체계 내에서 이윤이 어떻게 이해되었는가를 분석할 것이다. 그리고 더 나아가 이들의 이윤개념이 어떠한 연관성을 가지고 스미스의 이윤개념으로 발전되어 가는가를 살펴볼 것이다. 이런 방법으로 논의를 전개함에 있어서 그 촛점은 물론 이들 세 사람의 이윤개념의 차이에 주어질 것이지만 이것은 단순히 각자의 이론체계에 있어서의 한 부분에 대한 연구에 그치는 것이 아니다. 왜냐하면 자본의 이윤을 어떻게 파악할 것인가 하는 것은 특히 정치경제학의 경우에 있어서는 전체이론의 성격을 규정하는 결정적인 잣대가 되기 때문이다.

견인용 동기전동기의 시동 및 운전특성 해석에 관한 연구

황정원,조용길,송호신,박한규,우정인 東亞大學校 1994 東亞論叢 Vol.31 No.1

It needs a large capacity of equipments to test the starting performance of middle and large synchronous motors in a factory. This paper propose a new method which is the combination of single phase AC applied test and usual routine test with a small synchronous test machine and testing equipments. We can obtain the results from these proposed tests as follows ; (1) The starting performance and stabilized operation at variable speed is predicted from this results. (2) The armature winding leakage reactance is resulted from the no-load saturation curve, the short-circuit charactristic curve and the armature-reaction magnetomotive force converted to the field current. (3) This test must be performed twice, one for short-circuiting the field winding, the other for joining a resistance between the field terminals, as a result the unknown constants in equivalent circuits are identified. (4) Inverter-fed three phase voltage with variable frequency is applied to armature terminals, as a result, We show the actual armature leakage reactance and reaction of the induced harmonic voltages from rotor.

습식화학법에 의한 TiO_(2)/수산화아파타이트 생체복합재료의 제조

황규홍,정항철,이종국 조선대학교 생산기술연구소 2003 生産技術硏究 Vol.25 No.1

TiO₂/Hydroxyapatite (HAp,Ca_10(PO₄)_(6)(OH)₂) composite powders were prepared by mixing of the TiO₂ and the HAp powders which had been synthesized through sol-gel, precipitation, hydrothermal and mechanochemical-hydrothermal methods The mixing ratio was fixed with 1 1 ratio (Ti0₂/HAp,wt %). TiO₂/HAp composite powders showed different microstructures depending on their particle size and shape The nano-sized HAp particles were coated on the surface of large TiO₂ particles, whereas they were well mixed and dispersed when both TiO₂ and HAp were nanocrystallites.

퍼지논리를 이용한 자기 주도적 학습 능력과 시험 능력 평가 방법

정회인,양황규,김광백 한국컴퓨터교육학회 2004 컴퓨터교육학회 논문지 Vol.7 No.2

본 논문에서는 학습자 스스로가 학습 능력을 조절하고 학습 능력과 시험 능력을 객관적으로 판단할 수 있는 자기 주도적 학습 능력 및 시험 능력 평가 방법을 제안하였다. 제안된 자기 주도적 학습 능력 및 시험 능력 평가 방법은 삼각형 타입의 소속 함수와 퍼지 논리를 이용하여 학습 능력과 시험 능력의 소속도를 계산하고 각각에 대해 퍼지 등급도를 부여하였다. 학습 능력의 소속도와 시험 능력의 소속도에 대해서 퍼지 관계의 연산 및 합성에 의해 최종 소속도를 계산하고 퍼지 등급도를 결정하여 삭습자가 학습 능력의 소속도와 시험 능력의 소속도 및 최종 퍼지 등급도를 분석하여 스스로 학습을 조정할 수 있도록 하였다. 그리고 제안된 연구 내용을 인터넷 정보 검색사 필기 과목에 적용하여 구현하였다. In this thesis, We propose the self-directed learning and test-performing abilities assessment method to evaluate the learning and the test-performing abilities in which learners can not only control their own learning abilities for themselves, but also judge objectively learning and test-performing abilities. This method shows the membership degree of learning and test-performing abilities by using both the triangle-type membership function and the fuzzy logic. In addition, it gives the fuzzy grades to each item. The final membership degrees are calculated and the fuzzy grades are decided by the operation and composition of fuzzy relations on the membership degrees of learning and test-performing abilities. In this method, which is applicable to a writing subject for information searchers, learners are asked to analyse the membership degrees of the learning and test-performing abilities and the final fuzzy grades and to adjust a learning process for themselves.

G.P.S.개념을 이용한 뿌리말뚝공법의 준3차원적 유한요소해석에 관한 연구

黃正奎,朴史元 弘益大學校 科學技術硏究所 1997 科學技術硏究論文集 Vol.8 No.-

The root pile system is in-situ soil reinforcement technique that uses a series of reticulately installed micropiles. In terms of mechanical improvement by means of grouted reinforcing elements, the root pile system is similar to the soil nailing system. The main difference between root piles and soil nailing is that the reinforcing bars in root piles are normally grouted under high pressure and that the alignments of the reinforcing members differ. Recently, the root pile system has been broadly used to stabilize slopes and retain excavations. This paper proposes a quasi-three dimensional method of analysis for the root pile system applied to the stabilization of slopes. The proposed method of analysis includes ⅰ) a technique to evaluate quasi-three dimensional limit-equilibrium stability for sliding, ⅱ) a technique to predict the stability with respect to plastic deformation of the soil between adjacent root piles, and ⅲ) a quasi-three dimensional finite element technique to compute stresses and displacements of the root pile structure based on the generalized plane strain condition and composite unit cell concept along with considerations of the group effect and knot effect.

殘留應力 및 波動理論에 의한 말뚝의 打擊應力 解析

黃正奎 弘益大學校 1985 弘大論叢 Vol.17 No.2

Predicting pile stresses, for design of precast piles, selection of driving hammers and discription of piling specifications, using the existing pile-driving formulas and the numerical methods based on wave equation analysis, usually result in various uncertainties and limitations which can yield erroneous results because none of the existing methods could explain completely the delicate variations of hammer-pile-soil interaction depending on the pile-driving conditions. A new analysis of driving stress on piles developed herein is based on the fundamental mechanics of stress waves in prismatic rods and considered the effects of residual stresses induced by reversed friction. The plot of calculated stress used the new method shows good correlation with the earlier field investigations previously reported by others.

고속전철 추진 시스템의 미끄럼 방지 제어기법에 관한 연구

황돈하,김동희,노채균,심광열,조규판,정원영 영남대학교 공업기술연구소 1999 工業技術硏究所論文集 Vol.27 No.2

Induction motor drive with PWM inverter control has been developed for Korean High Speed Railways. To improve traction performance, the anti-slip control(ASC) to recover adhesion must be considered. This paper describes a novel hybrid anti-slip control method for the induction motor drive. By introducing the vector control for drive system, quick response of the motor torque can be achieved when wheels are going to slip. A hybrid control scheme by mixing two conventional control methods (slip velocity feedback control and slip detection pattern control) for wheel slip and re-adhesion is proposed. This control method is simulated by motor drive, train load, and friction-creep models. The train running simulation results based on induction motor vector control with PWM inverter show that good re-adhesion characteristics are obtained.