• Journal of Environmental Impact Assessment
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• v.22 no.6
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• pp.713-724
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• 2013

In terms of waste load allocation, inequality of waste load discharge must be considered as well as economic aspects such as minimization of waste load abatement. The inequality of waste load discharge between areas was calculated with Gini coefficient and was included as one of the objective functions of the multi-objective waste load allocation. In the past, multi-objective functions were usually weighted and then transformed into a single objective optimization problem. Recently, however, due to the difficulties of applying weighting factors, multi-objective genetic algorithms (GA) that require only one execution for optimization is being developed. This study analyzes multi-objective waste load allocation using NSGA-II-aJG that applies Pareto-dominance theory and it's adaptation of jumping gene. A sensitivity analysis was conducted for the parameters that have significant influence on the solution of multi-objective GA such as population size, crossover probability, mutation probability, length of chromosome, jumping gene probability. Among the five aforementioned parameters, mutation probability turned out to be the most sensitive parameter towards the objective function of minimization of waste load abatement. Spacing and maximum spread are indexes that show the distribution and range of optimum solution, and these two values were the optimum or near optimal values for the selected parameter values to minimize waste load abatement.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.2
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• pp.139-152
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• 2008

A series of numerical experiments were carried out to simulate the rock cutting behavior by TBM disc cutter in a given took condition. AUTODYN-3D, a commercial program capable of simulating three-dimensional dynamic failure, was utilized to carry out the numerical tests over four different disc cutter spacing conditions. After modelling three-dimensional geometries of disc cutter and rock specimen, the linear cutting tests by a disc cutter were simulated for eight different types of rocks. The numerical result, that is the optimum cutter spacing for isotropic rocks had the good agreements with those from linear cutting test. However, for relatively anisotropic or jointed rocks, the specific energy obtained from the numerical tests was almost two-times bigger than the real linear cutting results. Therefore, to simulate cutting procedures for anisotropic rocks realistically, further studies would be necessary.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.1
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• pp.40-47
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• 1987

Under the different conditions of planting density and compound fertilizer level, some agronomic and chemical characteristics of burley tobacco were investigated from 1982 to 1984. Leaf area and dry leaf weight per plant, crop growth rate, relative growth rate and net assimilation rate for 40-60 days after transplanting were higher with increasing plant spacing and fertilizer, but leaf area index was lower with increasing plant spacing. At topping stage, the leaf size was increased with increasing plant spacing and amount of fertilizer applied and the stem diameter was increased by increasing plant spacing. Leaf area, leaf weight per plant and weight per unit leaf area of harvested leaf were higher when plant spacing and fertilizer increased. It was estimated that the optimum plant spacing was 105cm x 34cm and level of com-pound fertilizer (N-P$_2$ O$\sub$5/ -K$_2$O =10-10-20) was 263kg/l0a for high yield. There were trends toward increase the contents of total alkaloid and total nitrogen with increasing plant spacing and fertilizer application. There was significant positive correlation between plant spacing and total nitrogen, and between fertilizer application and total nitrogen. The plant spacing of 105cm x 35 to 40cm and 227.5kg/l0a of fertilizer level may be profitable for farm economy and the low nitrogenous leaf.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.4
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• pp.335-338
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• 1992

A Cheju-leading mungbean cultivar Seonhwanogdu was seeded at 20, 30, 40, 50 and 60cm row width with within-row plant spacing of 10cm in mid-June of 1988 to 1990 to determine effects of row width on growth and seed yield of mungbean in Cheju area. Initial flowering and maturing dates were not influenced by the row width. Stem length, pods per plant, seeds per pod, 1000-seed weight linearly decreased as row width decreased because planting density increased. The relationship between seed yield and row width was quadratic, and the optimum row width with within-row plant spacing of 10cm for higher yield of mungbean was 40cm in Cheju.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.4
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• pp.765-774
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• 1992

The effect of the interactive flow on convective heat transfer from two vertical isothermal parallel plates have been studied numerically by the finite difference method. The Reynolds number, Grashof number, the relative length, L$_{2}$/L$_{1}$, and the dimensionless plate spacing, b/L$_{1}$ are varied as parameters. In case of outside mean Nusselt number, left outside mean Nusselt numbers show same values as L$_{2}$/L$_{1}$ and b/L$_{1}$ increase, but right outside mean Nusselt numbers decrease as L$_{2}$/L$_{1}$ increases. The inside mean Nusselt numbers are constant at narrow spacings and increase at wide spacings as Grashof numbers increase. The optimun plate spacing on left inside mean Nusselt numbers is b/L$_{1}$=0.4 at Re=100 and b/L$_{1}$=0.3 at Re=200. For the right inside mean Nusselt number, the optimum plate spacings move to the narrow spacing as Reynolds numbers increase and L$_{2}$/L$_{1}$ decrease.

• Geomechanics and Engineering
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• v.32 no.6
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• pp.639-652
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• 2023

Stepped earth slopes incorporated with anti-slide piles are widely utilized in landslide disaster preventions. Explicit consideration of the three-dimensional (3D) effect in the slope design warrants producing more realistic solutions. A 3D limit analysis of the stability of pile stabilized stepped slopes is performed in light of the kinematic limit analysis theorem. The influences of seismic excitation and surcharge load are both considered from a kinematic perspective. The upper bound solution to the factor of safety is optimized and compared with published solutions, demonstrating the capability and applicability of the proposed method. Comparative studies are performed with respect to the roles of 3D effect, pile location, pile spacing, seismic and surcharge loads in the safety assessments of stepped slopes. The results demonstrate that the stability of pile reinforced stepped slopes differ with that of single stage slopes dramatically. The optimum pile location lies in the upper portion of the slope around L_x/L = 0.9, but may also lies in the shoulder of the bench. The pile reinforcement reaches 10% universally for a looser pile spacing D_c/d_p = 5.0, and approaches 70% when the pile spacing reaches D_c/d_p = 2.0.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.7A
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• pp.727-732
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• 2008

The transmit diversity as well as beamforming can increase the performance of wireless communication systems. It is well known that the requirement for the spacing between the neighboring antennas in transmit diversity and beamforming is contradictive to each other. Therefore it is necessary to find the optimum configuration of multiple antennas for getting the maximum performance under the condition that the total number of antennas at transmitter site and the total power of transmitter are fixed. In this paper, the procedure for finding the optimum configuration of multiple antennas was derived through searching the maximum capacity and BER in the combined system with the transmit diversity (Tx diversity) and beamforming.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.195-199
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• 2010

This experiment was conducted to develop optimum sesame cultivation practices as succeeding cropping system of watermelon in the greenhouse condition. We also compared major components in sesame seed cultivated in the greenhouse and open field condition. The adaptable varieties under the greenhouse condition were white sesame 'Pyoungan' and black sesame 'Jinki' which showed higher yield and disease resistance. We also conducted several experiments to determine optimum sowing date, planting density and pinching time. Grain yields were statistically different according to the several sowing dates. In general, sesame sowing on June 30th showed higher grain yields than July 10th, July 20th and July 30th in the greenhouse. We also found out sesame cultivation practice with the row spacing of 40 cm and interplant spacing of 30 cm (a few branch type) or 40 cm (many branch type) showed higher yield than other treatments. Optimum pinching time was 25 days after first flowering in main stem when thousand seed weight and grain yield were highest. In the comparison of major components of sesame at the different cultivation conditions, sesame seeds cultivated in the greenhouse contained 4% much more oil content than open field condition. The lignan compounds, sesamin and sesamolin were also higher by 6% in the greenhouse than open field condition. It was concluded that sesame cultivation practices as succeeding cropping system of watermelon in the greenhouse condition guaranteed higher grain yield with less labor input which is now emerging alternative farming practice system in present aging rural society and will also give sesame cultivation farmers to increase net income in Korea.

• Geomechanics and Engineering
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• v.15 no.3
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• pp.811-822
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• 2018

Chip size distribution can be used to evaluate the cutting efficiency and to characterize the cutting behavior of rock during cutting and fragmentation process. In this study, a series of linear cutting tests was performed to investigate the effect of cutting conditions (specifically cut spacing and penetration depth) on the production and size distribution of rock chips. Linyi sandstone from China was used in the linear cutting tests. After each run of linear cutting machine test, the rock chips were collected and their size distribution was analyzed using a sieving test and image processing. Image processing can rapidly and cost-effectively provide useful information of size distribution. Rosin-Rammer distribution pamameters, the coarseness index and the coefficients of uniformity and curvature were determined by image processing for different cutting conditions. The size of the rock chips was greatest at the optimum cut spacing, and the size distribution parameters were highly correlated with cutter forces and specific energy.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.3
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• pp.75-79
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• 2008

Transmission line characteristics in microstrip line is used to in this paper. 5-microstrip lines composed of various spacing between them suggests characteristics of a diplexer in simulation. By applying the simiulation results, the diplexer realized shows better results of flat responses in bandpass characteristics and bandstop characteristics around 15 dB than symmetric spacing one.