• Geophysics and Geophysical Exploration
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• v.25 no.3
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• pp.99-108
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• 2022

Among induced polarization (IP) methods, spectral IP (SIP) uses alternating current as a transmission source to measure amplitudes and phase of complex electrical resistivity at each source frequency, which disperse with respect to source frequencies. The frequency dependence, which can be explained by a relaxation model such as Cole-Cole model or equivalent models, is analyzed to estimate SIP parameters from dispersion curves of complex resistivity employing multi-objective optimization (MOO). The estimation uses a generic algorithm to optimize two objective functions minimizing data misfits of amplitude and phase based on Cole-Cole model, which is most widely used to explain IP relaxation effects. The MOO-based estimation properly recovered Cole-Cole model parameters for synthetic examples but hardly fitted for the real laboratory measures ones, which have relatively smaller values of phases (less than about 10 mrad). Discrepancies between scales for data misfits of amplitude and phase, used as parameters of MOO method, and it is in necessity to employ other methods such as machine learning, which can deal with the discrepancies, to estimate SIP parameters from dispersion curves of complex resistivity.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.11a
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• pp.599-617
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• 2006

A network model and a Genetic Algorithm(GA) is proposed to solve the simultaneous estimation of the trip distribution and traffic assignment from traffic counts in the congested networks in a logit-based Stochastic User Equilibrium (SUE). The model is formulated as a problem of minimizing the non-linear objective functions with the linear constraints. In the model, the flow-conservation constraints of the network are utilized to restrict the solution space and to force the link flows meet the traffic counts. The objective of the model is to minimize the discrepancies between the link flows satisfying the constraints of flow-conservation, trip production from origin, trip attraction to destination and traffic counts at observed links and the link flows estimated through the traffic assignment using the path flow estimator in the legit-based SUE. In the proposed GA, a chromosome is defined as a vector representing a set of Origin-Destination Matrix (ODM), link flows and travel-cost coefficient. Each chromosome is evaluated from the corresponding discrepancy, and the population of the chromosome is evolved by the concurrent simplex crossover and random mutation. To maintain the feasibility of solutions, a bounded vector shipment is applied during the crossover and mutation.

• Journal of the Korean association of regional geographers
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• v.21 no.4
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• pp.716-727
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• 2015

The location and distribution of daycare centers do not reflect local daycare demand enough although government has increased facilities and financial supports to solve the low birthrate as a social problem. This study tried to examine spatial inequality of daycare center distribution by comparing the number of daycare facilities between city and rural communities in Jeollanam-Do. Analyzing the differences between city (5 Cities) and rural area (17 Guns) in Jeollanam-Do, it has been found that there were large differences in the number of available facilities per 1,000 children between Cities (10.9 facilities) and Guns as rural area (6.2 facilities). The average number of facilities in each City and Gun also showed a large discrepancy as a City has 147.8 facilities and a Gun has 15.4 facilities, respectively. There were total 78 Dong or Myeon with no facility at all as a dead zone of daycare, and 8 of them were Myeons in cities with 560 children, which accounted for 0.7% of total population of children in cities. On the other hand, 70 Myeons in Guns with 5,269 children have no facilities at all, which accounted for 11% of total population of children in Guns. Public facilities that parents prefer were more in cities (87) than Guns (28). Therefore, it is necessary to consider various childcare policies with minimizing discrepancies between city and rural area and investigating more accurate local demands and characteristics.

• Journal of Cadastre & Land InformatiX
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• v.52 no.2
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• pp.67-80
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• 2022

This study proposes a legal limit from the administrative and management standpoint of the city hall/county office/gu office, which is the cadastral authority, in relation to the discrepancy between the actual land use status and the cadastral study that has been continuously raised. And also, from the point of view of civil complaints such as landowners, this study tried to evaluate the practical problems of the current land category system from the point of view of civil complaints such as landowners and to derive a solution to these problems. Therefore, this study indicates how the category of land use is classified, and how land use is restricted by the laws of Registration & Management of public cadastre. Also, it shows the reasons why discrepancy between the land use fixed by the law and the current state of actual use of land occurs. Addtionally, This study suggests a plan to reorganize the Land Category system and it includes consolidation and subdivision of land. The study also describes a way to minimize the targets for conversion of land under control of Land Category System as well as to improve the law that protects the people's property rights.

• Radiation Oncology Journal
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• v.25 no.1
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• pp.54-61
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• 2007

[ $\underline{Purpose}$ ]: The purpose of this study is to develop a practical method for determining accurate marker positions for prostate cancer radiotherapy using CT images and kV x-ray images obtained from the use of the on- board imager (OBI). $\underline{Materials\;and\;Methods}$: Three gold seed markers were implanted into the reference position inside a prostate gland by a urologist. Multiple digital image processing techniques were used to determine seed marker position and the center-of-mass (COM) technique was employed to determine a representative reference seed marker position. A setup discrepancy can be estimated by comparing a computed $COM_{OBI}$ with the reference $COM_{CT}$. A proposed algorithm was applied to a seed phantom and to four prostate cancer patients with seed implants treated in our clinic. $\underline{Results}$: In the phantom study, the calculated $COM_{CT}$ and $COM_{OBI}$ agreed with $COM_{actual}$ within a millimeter. The algorithm also could localize each seed marker correctly and calculated $COM_{CT}$ and $COM_{OBI}$ for all CT and kV x-ray image sets, respectively. Discrepancies of setup errors between 2D-2D matching results using the OBI application and results using the proposed algorithm were less than one millimeter for each axis. The setup error of each patient was in the range of $0.1{\pm}2.7{\sim}1.8{\pm}6.6\;mm$ in the AP direction, $0.8{\pm}1.6{\sim}2.0{\pm}2.7\;mm$ in the SI direction and $-0.9{\pm}1.5{\sim}2.8{\pm}3.0\;mm$ in the lateral direction, even though the setup error was quite patient dependent. $\underline{Conclusion}$: As it took less than 10 seconds to evaluate a setup discrepancy, it can be helpful to reduce the setup correction time while minimizing subjective factors that may be user dependent. However, the on-line correction process should be integrated into the treatment machine control system for a more reliable procedure.