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.

HELP Model을 이용한 매립지 침출수 발생량 예측

정규호,서상원,황선진 경희대학교 환경연구소 2001 環境硏究 論文集 Vol.10 No.-

Estimation of landfill leachate generation is main issue that determain leachate collection system and scale of disposal system. Other reason is indirect estimation of damage of collection, drainage and disposal system for generation difference and control. The subject of this study is that Sudogwon landfill site #1 is landfill closure site. Actual leachate start 493 m^(3)/day at Jan. 1993 and maintain 5,000∼7,000 m^(3)/day after 1997. The other side estimation from HELP Model is 3,000∼6,000 m^(3)/day for same period. But concerned with condensation water and compression by increased layers, historical actual leachate geneation and estimation from HELP Model are similar.

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.

지진의 영향을 고려한 영팽창선이론에 의한 얕은기초의 지지력해석

黃正奎,申東勳 弘益大學校 科學技術硏究所 1994 科學技術硏究論文集 Vol.4 No.-

The present study was made based on the zero extension line theory and the seismic coefficient method to determine the seismic bearing capacity of shallow foundation. The zero extension line theory, which was proposed by Roscoe et al., presumes the coincidence between the loci of failure and the zero extension lines in soil mass. In order to compute the seismic bearing capacity of shallow foundation with smooth base mobilized by an earthquake, it was assumed that subsoils beneath the foundation are dense and cohesionless sandy soils, there are no changes in soil parameters during earthquake, and only horizontal earthquake intensity is considered. The presented theories were successfully compared with the conventional bearing capacity theories. And the effects of embedment depth of footing, earthquake intensity, dilation angle and internal friction angle of soil, on the bearing capacity factors were analysed. Finally a simplified formula for bearing capacity factor of N?? in earthquake was also provided.

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.

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.

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.

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.

축구선수의 Detraining과 Retraining이 혈청지질 및 호르몬농도에 미치는 영향

정정화,박재현,채종훈,성혜련,황지인,윤미숙,노금선,윤종관,윤영학,노순덕,정경숙,박일규,김은희,박현태,박상갑 대한스포츠의학회 1999 대한스포츠의학회지 Vol.17 No.1

The purpose of this study was to investigate the effects of detraining and retraining on serum lipid and hormones in soccer players. Subjects were seven male high-school soccer players. V˙O_2max was determined for each subjects by administering a treadmill test(initial speed: 90m/min, grade: 5%, increasing speed per 3 min: 30m/min). Serum lipid(T-C, TG, HDL-C LDL-C) and hormones(epinephrine, norepinephrine, growth hormones, cortisol) were assayed pre and post detraining in 10, 20, 30 days after retraining. The repeated ANOVA was used to determine significant differences. The 0.05 level of significance was as critical level for the study. The results of the study were as follows: 1. V˙O_2max(ml/min) were 3576.3±204.2ml/min pre detraining, 3234.1±198.9 ml/min post detraining. There are significant(p<.05) difference between pre and post detraining. In 10, 20, 30 days after retraining, V˙O_2max(ml/min) were 3601.4±170.9 ml/min. There were significantly(p<.05) increased in retraining periods. 2. V˙O_2max(ml/kg/min) were significantly(p<.05) decreased from 62.3±2.9 ml/kg/min to 55.9±4.7 ml/kg/min in detraining. In 10, 20, 30 days after retraining, V˙O_2max(ml/kg/min) were 62.4±3.4ml/kg/min, 62.7±2.3ml.kg/min, 67.3±7.2ml/kg/min respectively. There were significantly(p<.05) increased in retraining periods. 3. T-C were significantly (p<.05) increased from 166.6±8.5mg/dl to 175.3±10.3 mg/dl in detraining. In 10, 20, 30 days after retraining, T-C were 160.1± 3.2mg/dl, 156.7±3.7mg/dl, 140.3±9.0mg/dl. There were significantly(p<.05) decreased in retraining periods. 4. HDL-C were 61.4±6.6mg/di pre detraining, 5.3±6.6mg/dl post detraining. There are significant(p<.05) difference between pre and post detraining. In 10, 20, 30 days after retraining, HDL-C were 56.9±7.1mg/dl, 56.4±9.2mg/dl, 57.7±9.1mg/dl respectively. There were no significant difference in retraining periods. 5. The hormones(epinephrine. norepinephrine, growth hormone, cortisol) were changed as same patterns. Epinephrine were 26.0±7.0[g/ml pre detraining, 24.6±3.2pg/ml post detraining. In 10, 20, 30 days after retraining, epinephrine were 26.9±5.6pg/ml, 30.6±6.2pg/ml, 29.4±5.6pg/ml respectively. There were no significant difference in retraining periods. In conclusion, HDL-C, epinephrine, norepinephrine, growth hormone and cortisol were decreased, T-C, LDL-C and TG were increased in detraining. But HDL-C, epinephrine, norepinephrine, growth hormone and cortisol were increased, T-C, LDL-C and TG were decreased in retraining.

점증하중시 Sand Drain에 의한 압밀해석

黃正奎,金正瓚 弘益大學校 1988 弘大論叢 Vol.20 No.2

R.A. Barron has developed a theory on the consolidation by radial flow to drain wells under an instantaneous load condition. In this paper some formulas which were derived from the Barron's and Olson's theories are presented and observed in order to obtain more reasonable and practical solution of consolidation by sand drains with the peripheral smear zone and well resistance under consideration of a ramp load condition.