• Journal of the Korean housing association
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• v.18 no.2
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• pp.121-128
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• 2007

The investigation of the apartment housing as a dwelling type has become the most important and popular research subject to understand the housing culture in Korea. In their methods of typological analysis, it is found that most studies represent each unit plan as a simplified architectural drawing. This type of typology, however, has difficulties in processing a large scale of data set because each representation of a plan contain too many informations. To deal with this problem, this study suggests a new graph-theoretical method by which apartment plans can be represented in a more simple and effective way. This new method is also tested against the sample plans from Gangnam-gu area in Seoul to reveal the design logic hidden in plan configuration. Through a series of analyses, it is verified that there exist a design strategy that guides the particular pattern of zoning and allocation of each room in the plan.

• Journal of the Society of Naval Architects of Korea
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• v.38 no.2
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• pp.79-86
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• 2001

This study shows an attempt to generate an assembly sequence and its model for a ship block assembly using the graph theory and graph algorithms. To generate the ship block assembly, we propose four levels of the ship block assembly model such as "geometry mode1", "relational model", "sequential mode1", and "hierarchical model". To obtain the relational model, we used surface and surface intersection algorithm. The sequential model that represents a possible assembly sequence is made by using several graph algorithms from the relational model. The hierarchical model will be constructed from the sequential model in order to represent the block assembly tree and so forth. The purpose of the hierarchical model is to define an assembly tree and to generate the Bill Of Material(BOM). Lastly, the validity of the method proposed in this study is examined with application to ship block assembly models of a single type and double type according to four models mentioned above.

• Journal of the Korea Society of Computer and Information
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• v.25 no.4
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• pp.123-131
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• 2020

The pattern query in graph database has advantages of easy query expression and high query processing performance compared to relational database SQL. However, unlike the relational database, the graph database may not utilize the advantages of pattern query depending on modeling because the methodology for building the logical data model is not defined. In this study, in the is-a node modeling method that appears during the graph modeling process, we experiment that there is a difference in performance between graph pattern query when designing with a generalization model and designing with a specialization model. As a result of the experiment, it was shown that better performance can be obtained when the is-a node is designed as a specialization model. In addition, when writing a pattern query, we show that if a variable is bound to a node or edge, performance may be better than that of the variable of not bounded. The experimental results can be presented as an is-a node modeling method for pattern query and a graph query writing method in the graph database.

• Research in Mathematical Education
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• v.10 no.4 s.28
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• pp.259-288
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• 2006

This study considers the performance of students in Grades 5 to 10 on four tasks assessing students' ability to evaluate data presented in numerical form, for example, in a list or table, or in graphical form, for example, in a frequency graph or scatter graph. The ability to tell a story from data or a graph is an important aspect of statistical literacy. The samples provide the opportunity to consider the association of two pairs of items, one from each type of interpretation, numerical and graphical. Educational implications for the outcomes and the classroom use of the items are considered.

• Journal of the Korean Mathematical Society
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• v.52 no.6
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• pp.1323-1336
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• 2015

Let S be a semigroup with 0 and R be a ring with 1. We extend the definition of the zero-divisor graphs of commutative semigroups to not necessarily commutative semigroups. We define an annihilating-ideal graph of a ring as a special type of zero-divisor graph of a semigroup. We introduce two ways to define the zero-divisor graphs of semigroups. The first definition gives a directed graph ${\Gamma}$(S), and the other definition yields an undirected graph ${\overline{\Gamma}}$(S). It is shown that ${\Gamma}$(S) is not necessarily connected, but ${\overline{\Gamma}}$(S) is always connected and diam$({\overline{\Gamma}}(S)){\leq}3$. For a ring R define a directed graph ${\mathbb{APOG}}(R)$ to be equal to ${\Gamma}({\mathbb{IPO}}(R))$, where ${\mathbb{IPO}}(R)$ is a semigroup consisting of all products of two one-sided ideals of R, and define an undirected graph ${\overline{\mathbb{APOG}}}(R)$ to be equal to ${\overline{\Gamma}}({\mathbb{IPO}}(R))$. We show that R is an Artinian (resp., Noetherian) ring if and only if ${\mathbb{APOG}}(R)$ has DCC (resp., ACC) on some special subset of its vertices. Also, it is shown that ${\overline{\mathbb{APOG}}}(R)$ is a complete graph if and only if either $(D(R))^2=0,R$ is a direct product of two division rings, or R is a local ring with maximal ideal m such that ${\mathbb{IPO}}(R)=\{0,m,m^2,R\}$. Finally, we investigate the diameter and the girth of square matrix rings over commutative rings $M_{n{\times}n}(R)$ where $n{\geq} 2$.

• Genomics & Informatics
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• v.15 no.1
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• pp.19-27
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• 2017

Understanding complex relationships among heterogeneous biological data is one of the fundamental goals in biology. In most cases, diverse biological data are stored in relational databases, such as MySQL and Oracle, which store data in multiple tables and then infer relationships by multiple-join statements. Recently, a new type of database, called the graph-based database, was developed to natively represent various kinds of complex relationships, and it is widely used among computer science communities and IT industries. Here, we demonstrate the feasibility of using a graph-based database for complex biological relationships by comparing the performance between MySQL and Neo4j, one of the most widely used graph databases. We collected various biological data (protein-protein interaction, drug-target, gene-disease, etc.) from several existing sources, removed duplicate and redundant data, and finally constructed a graph database containing 114,550 nodes and 82,674,321 relationships. When we tested the query execution performance of MySQL versus Neo4j, we found that Neo4j outperformed MySQL in all cases. While Neo4j exhibited a very fast response for various queries, MySQL exhibited latent or unfinished responses for complex queries with multiple-join statements. These results show that using graph-based databases, such as Neo4j, is an efficient way to store complex biological relationships. Moreover, querying a graph database in diverse ways has the potential to reveal novel relationships among heterogeneous biological data.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.868-870
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• 2001

Salient pole rotor type single phase SRM(switched reluctance motor) can be use axial direction magnetic flux and radial direction magnetic flux at the same time. Then, it has higher energy density per unit volume and can be lessened the shaft length of motor or exciting magnetic force. Additionally, it's durability is good because it is simple structure and driving device. Prototype of Salient pole rotor type single phase SRM was fabricated by using parameters of three phase SRM and 3D FEM analysis. Also, driving device was fabricated for prototype. Speed and torque characteristic was confirmed through the experiments, and flux linkage, which is important parameter of SRM for generating torque, was measured. The induction emf was calculated by using ideal inductance graph and current graph. Calculated emf and measured emf was compared for confirming loss of prototype in this paper.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.752-759
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• 2022

The instantiation of spaces as a discrete entity allows users to utilize BIM models in a wide range of analyses. However, in practice, their utility has been limited as spaces are erroneously entered due to human error and often omitted entirely. Recent studies attempted to automate space allocation using artificial intelligence approaches. However, there has been limited success as most studies focused solely on the use of geometric features to distinguish spaces. In this study, in addition to geometric features, semantic relations between spaces and elements were modeled and used to improve space classification in BIM models. Graph Convolutional Networks (GCN), a deep learning algorithm specifically tailored for learning in graphs, was deployed to classify spaces via a similarity graph that represents the relationships between spaces and their surrounding elements. Results confirmed that accuracy (ACC) was +0.08 higher than the baseline model in which only geometric information was used. Most notably, GCN was able to correctly distinguish spaces with no apparent difference in geometry by discriminating the specific elements that were provided by the similarity graph.

• International Journal of Computer Science & Network Security
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• v.23 no.7
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• pp.61-70
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• 2023

Image segmentation is a very crucial step in effective digital image processing. In the past decade, several research contributions were given related to this field. However, a general segmentation algorithm suitable for various applications is still challenging. Among several image segmentation approaches, graph-based approach has gained popularity due to its basic ability which reflects global image properties. This paper proposes a methodology to partition the image with its pixel, region and texture along with its intensity. To make segmentation faster in large images, it is processed in parallel among several CPUs. A way to achieve this is to split images into tiles that are independently processed. However, regions overlapping the tile border are split or lost when the minimum size requirements of the segmentation algorithm are not met. Here the contributions are made to segment the image on the basis of its pixel using min-cut/max-flow algorithm along with edge-based segmentation of the image. To segment on the basis of the region using a homogenous optimum cut algorithm with boundary segmentation. On the basis of texture, the object type using spectral partitioning technique is identified which also minimizes the graph cut value.

• Honam Mathematical Journal
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• v.36 no.1
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• pp.85-102
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• 2014

We show that if a graph G is compressed, then the proper part of the intersection poset of the corresponding graphical arrangement $A_G$ has the homotopy type of a wedge of spheres. Furthermore, we also indicate the number of spheres in the wedge, based on the number of adjacent edges of vertices in G.