• Journal of the Korean Society for Aviation and Aeronautics
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• v.26 no.4
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• pp.13-19
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• 2018

Master plan plans for new airports should estimate the approximate scale of the airside's moorings and terminals. The size of the pavilion can be determined by complex factors such as the operating hours of the operating company, the frequency of operation, and the aircraft class. Among them, the number of flights is calculated using the Horon-jeff equation because of the relationship between the number of flights and the time occupied by the mains. Since this estimation formula is a simplified formula, it is necessary to verify the appropriateness of the method of estimating the scale and to suggest improvement directions. Therefore, in this study, we propose a method of estimating the size of the western flags by investigating and analyzing the main airports of overseas airports to determine whether the application of the Horon-jeff formula is appropriate.

• Geomechanics and Engineering
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• v.30 no.6
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• pp.503-515
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• 2022

The permeability coefficient is an essential parameter for the study of seepage flow in fractured rock mass. This paper discusses the feasibility and application value of using readily available RQD (rock quality index) data to estimate mine water inflow and grouting quantity. Firstly, the influence of different fracture frequencies on permeability in a unit area was explored by combining numerical simulation and experiment, and the relationship between fracture frequencies and pressure and flow velocity at the monitoring point in fractured rock mass was obtained. Then, the stochastic function generation program was used to establish the flow analysis model in fractured rock mass to explore the relationship between flow velocity, pressure and analyze the universal law between fracture frequency and permeability. The concepts of fracture width and connectivity are introduced to modify the permeability calculation formula and grouting formula. Finally, based on the on-site grouting water control example, the rock mass quality index is used to estimate the mine water inflow and the grouting quantity. The results show that it is feasible to estimate the fracture frequency and then calculate the permeability coefficient by RQD. The relationship between fracture frequency and RQD is in accordance with exponential function, and the relationship between structure surface frequency and permeability is also in accordance with exponential function. The calculation results are in good agreement with the field monitoring results, which verifies the rationality of the calculation method. The relationship between the rock mass RQD index and the rock mass permeability established in this paper can be used to invert the mechanical parameters of the rock mass or to judge the permeability and safety of the rock mass by using the mechanical parameters of the rock mass, which is of great significance to the prediction of mine water inflow and the safety evaluation of water inrush disaster management.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1744-1746
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• 2004

This paper focuses on the problem of asymptotic stabilization for time-delay systems. To this end, a memoryless state feedback controller is proposed. Then, based on the Lyapunov method, a delay-dependent stabilization criterion is devised by taking the relationship between the terms in the Leibniz-Newton formula into account. Certain free weighting matrices are used to express this relationship and linear matrix inequalities (LMIs)-based algorithm to design the controller stabilizing the system.

• Korean Journal of Hydrosciences
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• v.1
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• pp.49-60
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• 1990

Manning's roughness factor to flow in sand-bed channels may be divided into the grain roughness factor nd the form roughness factor. The grain roughness factor may be dedermined by using Keulegan's formula. By using available experimental data, it was found there is a unique relationship between the form roughness and the hydraulic radius to sediment particle size ratio for a given value of the Froude number. The form roughness and the bed form may be determined by using this unique relationship. The technique for engineering applications of the results appears to be quite simple.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.2
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• pp.10-16
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• 2000

The purpose of this study is to identify relationships between a central angle and a radius of curvature of divided roads in flat terrain of traditional villages, suggesting layout criteria for traditional villages: Nak-an, Sung-Eup, Ha-Whe. This study is sought to find the optimum model through the various SAS regression analyses. a regression analysis of this data was adopted to induce the relationship formula between a central angle of curve and a radius of curvature. Results of this study are as follows: 1) Most of the divided roads in traditional villages have a complex curve rather than a simple curve. 2) A central angle of curve has ranged from 11$^{\circ}$to 127$^{\circ}$, with a mean degree of 63.9. 3) In the lower level of central angle(11-40$^{\circ}$), the branch roads have distributed with a high frequency, but with a low frequency in the higher level of central angle(90-140$^{\circ}$). 4) A radius of curvature in the divided roads has ranged from 0.9m to 59.6, but half of the roads have concentrated on 1-6m of the curvature. 5) Compared to the result of hilly villages in previous study(Ahn, 1999), value of central angels in flat villages is lower than that of hilly villages, while a mean value of the curvature is higher than that of hilly villages. 6) A Non-linear regression analysis, resulting from the SAS application, was useful method to induce a relationship formula between a central angle and a radius of curvature in the branch roads. Our study's formula is as follow: R=100.3*EXP(-0.06*$\delta$)+3.91. 7) Our study model has less error than that of the Kishizuka's method, being applicable to a broader range of the branch roads. 8) A minimum radius of curvature in our study has showed 3.9m, suggesting to reconsider applications of the Kishizuka's(5.8m) in the footpass design, In the study for this presupposition model the efficiency and utility of it can be estimated to grow large according to how much and how far it includes both extremes of data. This study is for the application to a design in future through the numerical formula of divided roads of various traditional villages. The studies from now on will be about the quasi-hilly quasi-hilly village and hilly village supplementing these factors more.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.1
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• pp.161-167
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• 2001

The purpose of this study is to find out the difference of Zoysia matrella's evaporation in between 100 percent soil and mixed soil with 50 percent of perlite to create green spaces on the artificial ground. It is believed that the weight against the artificial ground will be reduced, provided the vegetation is possible in the circumstance of the mixed sol with 50 percent of perlite. The study employed a modified Makkink's model by Iwasa who had developed the model for estimating Zoysia matrella's evaporation in the natural ground using the Makkink's formula in 1997 at Chiba University, Japan. The parameter of Makkink's formula is the solar radiation. For that reason, the Makkink's formula is simple and easy to measure the parameter and has a high utility. If the outcomes from mixed soil are close to modified Makkinks formula, the modified Makkink's formula will be applied to estimate in the artificial ground with mixed soil with 50 percent of perlite. Weather observation and actual amount of evaporation of Zoysia matrella have been measured, and the relation between weather condition and actual amount of evaporation had been also investigated. In line with this, we found out that there is a relevant relationship between daily average temperature, the modified Makkink's model by Iwasa, and the actual amount of evaporation. As the results of the experiment, the outcomes from mixed soil with 50 percent of perlite have very high relation to 100 percent soil. In addition, mixed soil has more adhesion with water than natural soil. However, it needs to be adequately maintained in terms of fertilization and damage from disease and harmful insects until the gras fastens its roots into the soil. By using mixed soil with 50 percent of perlite, the load from soil on the artificial ground can be reduced. The study on the growth of the grass throughout the plant vegetation and the actual amount of evaporation in the mixed soil with 50 percent of perlite should be performed in the future.

• The korean journal of orthodontics
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• v.29 no.3 s.74
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• pp.349-360
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• 1999

The concept of denture frame, both the vertical and horizontal relationship of the dentitions are ultimately related to a skeletal configuration, leads to postulate that the vertical overbite will be determined by the jaw rotations and anteroposterior jaw relationship. Also, ODI is analyzed to be composed of the determinant factors of overbite such as FMA PPA and FABA. From the geometric analyses of an interrelationship between the ODT and the overbite determinants, the following formula can be induced. ODI norm=$85^{\circ} - 0.5 PMA-(1.08 - 0.01 FMA)(FABA - 81^{\circ})$. This formula indicates that the norm of ODI is not constant value but variable one according to the individual skeletal frames. Through the application of the formula to the various clinical cases, it is proved that the new concept, relativity of the ODI norm, is very diagnostically useful.

• Survey Research
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• v.7 no.2
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• pp.1-38
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• 2006

This study was conducted to develop a happiness index for Korean. 16 factors of happiness derived from both exploratory and confirmatory factor analysis based on a nationwide sample of 1503 Korean adults were reclassified into 3 components of Alderfer's need theory. The LISREL was used to measure the weight of each happiness factor. The results showed that happiness index was functioned by a formula(Happiness=2.5*existence+2.5*relationship+5*growth). Applying this formula, the average happiness score for Korean was 57.71. It was also demonstrated that the degree of happiness differed according to individual's gender, region, and income. Men was happier than women, while there was no significant difference among ages. As far as the region concerned, those who live in Seoul and Daejeon were happier than the others. People who earn over 2,500,000 won per month were happier than the others in terms of economic status. Finally, the result of the discriminant function analysis revealed that individual or psychological growth factor was more important than existence and relationship factors. Based on these significant research findings, practical implications and future research directions were discussed.

• Journal of the Korean Geotechnical Society
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• v.20 no.9
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• pp.145-153
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• 2004

Based on the previous studies proposed by many researchers about the evaluation method of replacement depth, a modified formula which incorporates the effect factors such as embanked height and load, replacement depth, cohesive force of original ground and unit weight of embankment etc, was suggested in this study. The new proposed formula was applied in the three construction sites of Kwangyang-Bay Area (Yeocheon, Youlchon, and Kwangyang) constructed by the compulsion replacement method. The application of the new method was investigated through these case studies in domestics. A modified bearing capacity parameter was estimated form the relationship of modified embankment loading and ultimate bearing capacity resulted from the site investigation, and the replacement depth was predicted by using this parameter. In addition, through the relationship analyses between each effect factors to the replacement depth in two areas, Yeocheon and Youlchon, an empirical prediction method which can evaluate the replacement depth in adjoining area was proposed. The predicted value obtained by new method is approximately similar to the measured replacement depth in Kwangyang area.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.737-744
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• 2000

This paper resorts to rock mass rating and rock mass quality to draw value based on the evaluation of rock and to draw interrelation formula in relation to rock mass quality, A comparative analysis was given of survey values reported in the existing documents. This paper has tried to find out the relationship between RMR and Q System for the sake of choosing rational reinforcing patterns and of the safety of tunnels. The results run as follow: RMR=8.251n(Q)+43.83. This paper has also tried to find out the relationship between RMR and Q System by using Fuzzy Approximate Reasoning Concept. We suggest that those in charge should not depend on a single system only after evaluating the classification of rocks, and compare one result with another for the good of keeping track of the condition of base rocks in a better way.