• Membrane and Water Treatment
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• v.1 no.3
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• pp.181-192
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• 2010

A linear quantitative structure-property relationship (QSPR) model is presented for the prediction of rejection in permeation through membrane. The model was produced by using the multiple linear regression (MLR) technique on the database consisting of retention data of 25 pesticides in 4 different membrane separation experiments. Among the 3224 different physicochemical, topological and structural descriptors that were considered as inputs to the model only 50 were selected using several criteria of elimination. The physical meaning of chosen descriptor is discussed in detail. The accuracy of the proposed MLR models is illustrated using the following evaluation techniques: leave-one-out cross validation procedure, leave-many-out cross validation procedure and Y-randomization.

• Current Optics and Photonics
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• v.1 no.6
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• pp.631-636
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• 2017

We firstly develop a straightforward method to generate full $Poincar{\acute{e}}$ beams with any polarization geometry over an arbitrary order $Poincar{\acute{e}}$ sphere. We implement this by coaxial superposition of two orthogonal circular polarized beams with alternative topological charges with the help of a Mach-Zehnder interferometer. Secondly we find the existence of singularity points. And the inner relationship between their characteristics and the order of $Poincar{\acute{e}}$ spheres is also studied. In summary, this work provides a convenient and effective way to generate vector beams and to control their polarization states.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2009.04a
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• pp.23-25
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• 2009

Nowadays, owing to the development of techniques for collecting geographic information, an increasing need is thus appearing: integrating heterogeneous databases. This paper proposes an algorithm for finding matching relationship between two node sets in road network data. We found the corresponding node pair using link shape linked with them as well as their location. The accuracy of matching was grown by this process. Result then can be used to reflect the topological information in performing link matching.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11c
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• pp.1429-1432
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• 2003

This paper addresses the problem of finding a constrained nearest neighbor for moving query point(we call it CNNMP) The Nearest neighbor problem is classified by existence of a constrained region, the number of query result and movement of query point and target. The problem assumes that the query point is not static, as 1-nearest neighbor problem, but varies its position over time to the constrained region. The parameters as NC, NCMBR, CQR and QL for the algorithm are also presented. We suggest the query optimization algorithm in consideration of topological relationship among them

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.1051-1059
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• 2014

In this paper, we propose an intelligent situation recognition model by collecting and analyzing multiple sensor signals. Multiple sensor signals are collected for fixed time window. A training set of collected sensor data for each situation is provided to K2-learning algorithm to generate Bayesian networks representing causal relationship between sensors for the situation. Statistical characteristics of sensor values and topological characteristics of generated graphs are learned for each situation. A neural network is designed to classify the current situation based on the extracted features from collected multiple sensor values. The proposed method is implemented and tested with UCI machine learning repository data.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.5
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• pp.16-30
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• 2002

This study tried to understand an ambiguous urban landscape through a relational context. Gongpyeong district, an urban renewal area in Seoul, was selected as the site of the case study because traditional and modern styles coexist in this district. The research method and processes are summarized as follows. First, the district, which has both a redeveloped environment and an inherent environment, was divided into Yin & Yang structures. Next, an effort was made to grasp the fundamental relational characteristics(external relationships) of each type through three aspects: physical environment, activities, and meaning. As a result, Yin characteristics were found in the redeveloped environment which has predominantly Yang characteristics. In many cases, advertising, which is a Yang element, was missing in the redeveloped area. On the other hand, in the inherent environment which has Yin characteristics in general, shabby appearances were evident in aspects beyond advertising, and Yang elements, were found from the viewpoint of the theory of place. On the basis of these results, new dualistic frameworks with respect to the functions were re-structured, and complementary characteristics (internal relationship) based on topological aspects were analyzed. Unlike the monotonous appearances found in large scale environments, a variety of spatial characteristics were found in the various small scale environments. This explains that the dualistic coexistence has made a contribution to the complementary attributes of urban landscape. This study has the following ramifications. Much research of urban landscapes that has used western methodology which employs analytic aspects. As a methodology of urban landscape research this study introduced Iching, which tries to understand phenomena in a relational context. In addition, this study expects that the profound understanding of urban environments and the detailed relationship through this framework will suggest a new approach to urban planning, design and management related to future urban environments.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.284-284
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• 2016

Topological insulator (TI) is a bulk-insulating material with topologically protected Dirac surface states in the band gap. In particular, $Bi_2Se_3$ attracted great attention as a model three-dimensional TI due to its simple electronic structure of the surface states in a relatively large band gap (~0.3 eV). However, experimental efforts using $Bi_2Se_3$ have been difficult due to the abundance of structural defects, which frequently results in the bulk conduction being dominant over the surface conduction in transport due to the bulk doping effects of the defect sites. One promising approach in avoiding this problem is to reduce the structural defects by heteroepitaxially grow $Bi_2Se_3$ on a substrate with a compatible lattice structure, while also preventing surface degradation by encapsulating the pristine interface between $Bi_2Se_3$ and the substrate in a clean growth environment. A particularly promising choice of substrate for the heteroepitaxial growth is hexagonal boron nitride (h-BN), which has the same two-dimensional (2D) van der Waals (vdW) layered structure and hexagonal lattice symmetry as $Bi_2Se_3$. Moreover, since h-BN is a dielectric insulator with a large bandgap energy of 5.97 eV and chemically inert surfaces, it is well suited as a substrate for high mobility electronic transport studies of vdW material systems. Here we report the heteroepitaxial growth and characterization of high quality topological insulator $Bi_2Se_3$ thin films prepared on h-BN layers. Especially, we used molecular beam epitaxy to achieve high quality TI thin films with extremely low defect concentrations and an ideal interface between the films and substrates. To optimize the morphology and microstructural quality of the films, a two-step growth was performed on h-BN layers transferred on transmission electron microscopy (TEM) compatible substrates. The resulting $Bi_2Se_3$ thin films were highly crystalline with atomically smooth terraces over a large area, and the $Bi_2Se_3$ and h-BN exhibited a clear heteroepitaxial relationship with an atomically abrupt and clean interface, as examined by high-resolution TEM. Magnetotransport characterizations revealed that this interface supports a high quality topological surface state devoid of bulk contribution, as evidenced by Hall, Shubnikov-de Haas, and weak anti-localization measurements. We believe that the experimental scheme demonstrated in this talk can serve as a promising method for the preparation of high quality TI thin films as well as many other heterostructures based on 2D vdW layered materials.

• Spatial Information Research
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• v.13 no.2 s.33
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• pp.119-128
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• 2005

Most spatial data handled in GIS is two-dimensional. These two-dimensional data is established by selecting 2D aspects form 3D, or by projecting 3D onto 2D space. During this conversion, without user's intention, data are abstracted and omitted. This unwanted data loss causes disadvantages such as restrictingof the range of data application and describing inaccurate real world. Recently, three dimensional data is getting wide interests and demands. One of the examplesis Database Management System which can store and manage three dimensional spatial data. However, this DBMS does not support spatial query which is the essence of the database management system. So, various studies are needed in this field. This research designs spatial relationship that is defined in space database standard using the three-dimension space model. The spatial data model, which is used in this research, is the one defined in OGC for GMS3, and designing tool is DE-9IM based on Point-Set Topology blow as the best method for topological operation.

• Journal of Intelligence and Information Systems
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• v.19 no.1
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• pp.111-123
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• 2013

Semantic similarity/relatedness measure between two concepts plays an important role in research on system integration and database integration. Moreover, current research on keyword recommendation or tag clustering strongly depends on this kind of semantic measure. For this reason, many researchers in various fields including computer science and computational linguistics have tried to improve methods to calculating semantic similarity/relatedness measure. This study of similarity between concepts is meant to discover how a computational process can model the action of a human to determine the relationship between two concepts. Most research on calculating semantic similarity usually uses ready-made reference knowledge such as semantic network and dictionary to measure concept similarity. The topological method is used to calculated relatedness or similarity between concepts based on various forms of a semantic network including a hierarchical taxonomy. This approach assumes that the semantic network reflects the human knowledge well. The nodes in a network represent concepts, and way to measure the conceptual similarity between two nodes are also regarded as ways to determine the conceptual similarity of two words(i.e,. two nodes in a network). Topological method can be categorized as node-based or edge-based, which are also called the information content approach and the conceptual distance approach, respectively. The node-based approach is used to calculate similarity between concepts based on how much information the two concepts share in terms of a semantic network or taxonomy while edge-based approach estimates the distance between the nodes that correspond to the concepts being compared. Both of two approaches have assumed that the semantic network is static. That means topological approach has not considered the change of semantic relation between concepts in semantic network. However, as information communication technologies make advantage in sharing knowledge among people, semantic relation between concepts in semantic network may change. To explain the change in semantic relation, we adopt the cognitive semantics. The basic assumption of cognitive semantics is that humans judge the semantic relation based on their cognition and understanding of concepts. This cognition and understanding is called 'World Knowledge.' World knowledge can be categorized as personal knowledge and cultural knowledge. Personal knowledge means the knowledge from personal experience. Everyone can have different Personal Knowledge of same concept. Cultural Knowledge is the knowledge shared by people who are living in the same culture or using the same language. People in the same culture have common understanding of specific concepts. Cultural knowledge can be the starting point of discussion about the change of semantic relation. If the culture shared by people changes for some reasons, the human's cultural knowledge may also change. Today's society and culture are changing at a past face, and the change of cultural knowledge is not negligible issues in the research on semantic relationship between concepts. In this paper, we propose the future directions of research on semantic similarity. In other words, we discuss that how the research on semantic similarity can reflect the change of semantic relation caused by the change of cultural knowledge. We suggest three direction of future research on semantic similarity. First, the research should include the versioning and update methodology for semantic network. Second, semantic network which is dynamically generated can be used for the calculation of semantic similarity between concepts. If the researcher can develop the methodology to extract the semantic network from given knowledge base in real time, this approach can solve many problems related to the change of semantic relation. Third, the statistical approach based on corpus analysis can be an alternative for the method using semantic network. We believe that these proposed research direction can be the milestone of the research on semantic relation.

• Korean Institute of Interior Design Journal
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• v.21 no.4
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• pp.40-47
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• 2012

Courtyard is evolving from the conventional one element of a building far beyond into independent peremeter of urban architecture, of which function has been darmatically upgraded from embedded traditional air fluiding, nutural lighting system into where full fledged function can be experienced so much as your imagimation reaches taking major social responsibility such as intact offline social networking which links people from neighbors, inter / extra buiding openness which allow people can communicate among othewise between themselves and artificial natural environmental emelents supplier where people resort to relaxation and natural healing. Roles of courtyard has been by far streatched out into nearby natural healing space where people can shake off their unavoidable stresses from the modern life relaxing themselves looking at the sky otherwise observe natural surroundigns such as plants, flowers and waters. Thanks to hereonto mentioned its merits, Courtyard building is widely used and seen as a center of modern urban design in residence, public bilding and urban planned buildings. Courtyard biulding is nowadays boasting their morphological diversity brought out from lots of topological variation, type variants, cross section and inter relationship with the other neighboring spaces. Hence, hereby I have been studied how above mentioned three major peremeters of courtyard has been upgraded in modern architecture comparing the period from 1960 to 1990 and the period starting from 1991.