• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2009.04a
• /
• pp.89-92
• /
• 2009

본 논문에서는 비선형구조물의 위상최적화를 위하여 개발된 요소 연결 매개법 (Element Connectivity Parameterization Method)을 이용하여 기하비선형 구조물의 고유진동수(Eigenfrequency)를 최적화하는 연구를 소개한다. 기존의 밀도를 기반으로 한 위상최적화기법은 비선형 구조물의 위상최적화를 수행할 때 약한 탄성계수를 가지는 요소가 대변형을 일으켜 전체 강성행렬(Tangent Stiffness Matrix)이 양정정성(Positive definiteness)를 잃어버리는 문제점이 있어서 위상최적화를 수행하기 어렵다. 이 문제점을 해결하기 위하여 최근에 요소 연결 매개법(Element Connectivity Parameterization Method)이 개발되었다. 이 요소 연결 매개법은 요소의 강성을 설계하는 것이 아니라 요소의 연결성을 설계하는 기법으로 이를 이용하여 비선형 구조물의 위상최적화를 효과적으로 수행할 수 있다. 이 연구에서는 요소 연결 매개법을 동적인 문제에 적용하기 위한 연구를 수행하며 이를 이용하여 비선형 구조물의 고유진동수를 최적화 하는 위상최적화 문제에 적용하였다. 비선형 수치 예제를 통하여 기하 비선형 구조물의 고유진동수를 최대화를 통하여 기하 비선형 구조물의 강성최대화 문제와 같은 결과를 얻을 수 있었다.

• Proceedings of the Korean Society for Language and Information Conference
• /
• 2007.11a
• /
• pp.234-240
• /
• 2007

This paper argues that various kinds of displaced structures in English should be licensed by a more explicitly formulated type of rule schema in order to deal with what is called weak connectivity in English. This paper claims that the filler and the gap site cannot maintain the total identity of features but a partial overlap since the two positions need to obey the structural forces that come from occupying respective positions. One such case is the missing object construction where the subject fillers and the object gaps are to observe requirements that are imposed on the respective positions. Others include passive constructions and topicalized structures. In this paper, it is argued that the feature discrepancy comes from the different syntactic positions in which the fillers are assumed to be located before and after displacement. In order to capture this type of mismatch, syntactically relevant features are handled separately from the semantically motivated features in order to deal with the syntactically imposed requirements.

• Proceedings of the KSME Conference
• /
• 2004.04a
• /
• pp.1017-1022
• /
• 2004

Though the standard element density-based topology optimization method has been applied for the optimal design of multiphysics systems, some theoretical problems, such as material interpolation, undershoot temperature prediction, and unstable elements, still remain to be overcome. The objective of this investigation is to present a new topology optimization formulation based on the element connectivity parameterization (ECP) in order to avoid the numerical problems in multiphysics system design and improve optimization results. To show the validity of the proposed approach, the designs of an optimal thermal dissipation and an electro-thermal-compliant actuator were considered.

• Journal of Forest and Environmental Science
• /
• v.40 no.3
• /
• pp.241-249
• /
• 2024

Human development activities have led to changes in land cover, resulting in the loss of green spaces such as forests and agricultural lands. This loss accompanies issues of habitat reduction and hindrance to wildlife movement. Due to the decrease in urban green spaces, urban green connectivity is reducing. This study aims to analyze changes in green space connectivity through structural and functional changes in green spaces caused by land cover changes. Quantitative analysis of landscape patterns using landscape indices through Fragstats model was employed to analyze the structural changes in green spaces. This study used seven landscape indices to assess the fragmentation and isolation of green spaces. The analysis was focused on changes occurring in agricultural lands, forests, and grasslands within Yongin-si, South Korea, over 20 years from 1989 to 2019. Among the landscape indices for forests, PLAND showed a decrease of approximately 8.2% from 1989 to 2009, while NP exhibited a decline of about 2,025 patches. This indicates both a reduction in the total area of green spaces in Yongin-si. Also, we analyzed functional changes based on landscape index variations in forest land within the study area between 2009 and 2019, and least-cost path (LCP) analysis was conducted using Linkage Mapper. Results yielded 18 and 16 links for 2009 and 2019, respectively, with 12 common links. It was observed that five links showed a slight decrease, indicating partial deletions of links, contributing to the fragmentation and discontinuity of forests.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1999.10a
• /
• pp.127-134
• /
• 1999

An optimization algorithm based on Genetic Algorithm(GA) is developed for discrete optimization of reinforced concrete plane frame by constructing databases. Under multiple loading conditions, discrete optimum sets of reinforcements for both negative and positive moments in beams, their dimensions, column reinforcement, and their column dimensions are found. Construction practice is also implemented by linking columns and beams by group ‘Connectivity’between columns located in the same column line is also considered. It is shown that the developed genetic algorithm was able to reach optimum design for reinforced concrete plane frame construction practice.

• Journal of the Korean Society of Radiology
• /
• v.15 no.4
• /
• pp.507-518
• /
• 2021

Magnetic resonance imaging (MRI) is a key technology that has been seeing increasing use in studying the structural and functional innerworkings of the brain. Analyzing the variability of brain connectome through tractography analysis has been used to increase our understanding of disease pathology in humans. However, there lacks standardization of analysis methods for small animals such as mice, and lacks scientific consensus in regard to accurate preprocessing strategies and atlas-based neuroinformatics for images. In addition, it is difficult to acquire high resolution images for mice due to how significantly smaller a mouse brain is compared to that of humans. In this study, we present an Allen Mouse Brain Atlas-based image data analysis pipeline for structural connectivity analysis involving structural region segmentation using mouse brain structural images and diffusion tensor images. Each analysis method enabled the analysis of mouse brain image data using reliable software that has already been verified with human and mouse image data. In addition, the pipeline presented in this study is optimized for users to efficiently process data by organizing functions necessary for mouse tractography among complex analysis processes and various functions.

• Current Research on Agriculture and Life Sciences
• /
• v.27
• /
• pp.69-75
• /
• 2009

This research regard it as most meaningful to realize the importance of the hedgerow in cultivated areas functioning as a residual landscape element in rural landscape and set improvement guidelines through landscape character and value analysis to cope with landscape malfunction. The results of summary are as follows. 1) First of all, as a result of landscape character analysis of edge stripe in cultivated land in total of 7 case areas, for example, the edge stripe in cultivated land in case area 4 and 8 maintain the width of 10m and are assessed satisfactory in terms of vegetation development condition, appearance of living species, connectivity, buffer capacity and so on. Also, as a result of structural character of correlation analysis among items, the correlation coefficient between width and appearance of living species showed 0.941, the highest. Following are connectivity and appearance of living species and width and buffer capacity respectively: 0.841 and 0.740. 2) As a result of landscape character analysis of uncultivated stripe in total of 6 case areas, it is analyzed that case area 4 maintains the widest width as almost 4.5m average width and considered valuable as I degree in vegetation development condition, filtering, and connectivity. 3) As a result of problem analysis of uncultivated stripe, for example, case 3, 9, and 10 was analyzed that the width was below 1.25m which is too small to carry out the function of buffer and habitat for living creature, so minimum standard width was set between 4~5m through comprehensive analysis of character of each case area. Based on the result above landscape character, value and problem analysis, main improvement guidelines are set in terms of width, connectivity, filtering, and vegetation development, restrictive practices and so on.

• The Korean Journal of Applied Statistics
• /
• v.29 no.6
• /
• pp.1129-1145
• /
• 2016

Functional neuro-connectivity is one of the main issues in brain science in the sense that it is closely related to neurodynamics in the brain. In the paper, we choose fMRI as a main form of response data to brain activity due to its high resolution. We review methods for analyzing functional neuro-connectivity assuming that measurements are made on physiological responses to neuron activation. This means that we deal with a state-space and measurement model, where the state-space model is assumed to represent neurodynamics. Analysis methods and their interpretation should vary subject to what was measured. We included analysis results of real fMRI data by applying a high-dimensional autoregressive model, which indicated that different neurodynamics were required for solving different types of geometric problems.

• Journal of Soil and Groundwater Environment
• /
• v.15 no.6
• /
• pp.91-98
• /
• 2010

The effective thermal conductivity of porous materials is usually determined by porosity, water content, and the conductivity of the matrix. In addition, it is also affected by the internal structure of the materials such as the size, arrangement, and connectivity of the matrix-forming grains. Based on the structural models for multi-phase materials, thermal conductivities of soils and sands measured with varying the water content were analyzed. Thermal conductivities of dry samples were likely to fall in the region between the Maxwell-Eucken model with air as the continuous phase and the matrix as the dispersed phase ($ME_{air}$) and the co-continuous (CC) model. However, water-saturated samples moved down to the region between the $ME_{wat}$ model and the series model. The predictive inconsistency of the structural models for dry and water-saturated samples may be caused by the increase of porosity for water-saturated samples, which leads to decrease of connectivity among the grains of matrix. In cases of variably saturated samples with a uniform grain size, the thermal conductivity showed progressive changes of the structural models from the $ME_{air}$ model to the $ME_{wat}$ model depending on the water content. Especially, an abrupt increase found in 0-20% of the water content, showing transition from the $ME_{air}$ model to the CC model, can be attributed to change of water from the dispersed to continuous phase. On the contrary, the undisturbed soil samples with various sizes of grains showed a gradual increase of conductivity during the transition from the $ME_{air}$ model to the CC model.

• Science of Emotion and Sensibility
• /
• v.22 no.1
• /
• pp.35-44
• /
• 2019

Individuals with problematic hypersexual behavior (PHB) evince the inability to control sexual impulses and arousal. Previous studies have identified that these characteristics are related to structural and functional changes in the brain region responsible for inhibitory functions. However, very little research has been conducted on the functional connectivity of these brain areas during the resting state in individuals with PHB. Therefore, this study used functional magnetic resonance imaging devices with the intention of identifying the deficit of the functional connectivity in the executive control network in individuals with PHB during the resting state. Magnetic resonance imaging data were obtained for 16 individuals with PHB and 19 normal controls with similar demographic characteristics. The areas related to the executive control network (LECN, RECN) were selected as the region of interest, and the correlation coefficient with time series signals between these areas was measured to identify the functional connectivity. Between groups analysis was also used. The results revealed a significant difference in the strength of the functional connectivity of the executive control network between the two groups. In other words, decreased functional connectivity was found between the superior/middle frontal gyrus and the caudate, and between the superior/middle frontal gyrus and the superior parietal gyrus/angular gyrus in individuals with PHB. In addition, these functional Connectivities related to the severity of hypersexual behavior. The findings of this study suggest that the inability to control sexual impulses and arousal in individuals with PHB might be related to the reduced functional connectivity of executive control circuits.