• Journal of applied mathematics & informatics
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• v.17 no.1_2_3
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• pp.475-484
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• 2005

The main aim of this paper is to consider the fuzzy norm, define the fuzzy Banach spaces, its quotients and prove some theoremes and in particular Open mapping and Closed graph theoremes on these spaces.

• Journal of the Korea Society of Computer and Information
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• v.27 no.9
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• pp.77-89
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• 2022

In this paper, we propose a system which automatically generates SHACL schemas to describe and validate RDF knowledge graphs constructed by RML mappings. Unlike existing studies, the proposed system generates the schemas based on not only RML mapping rules but also metadata extracted from RML mapping input data in various formats such as CSV, JSON, XML or databases. Therefore, our schemas include the constraints on data type, string length, value range and cardinality, which were not present in the existing schemas. And we solves the problem with "repeated properties" which overlooked in existing studies. Through a conformance test consisting of 297 cases, we show that the proposed system generates correct constraints for the graphs. The proposed system can contribute to automation of the tedious and error-prone existing manual validation processes.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.1
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• pp.69-77
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• 2021

The widely used low-cost design methodology for IoT devices is very popular. In such a networked device, memory is composed of flash memory, SRAM, DRAM, etc., and because it processes a large amount of data, memory design is an important factor for system performance. Therefore, each device selects optimized design factors such as function, performance and cost according to market demand. The design of a memory architecture available for low-cost IoT devices is very limited with the configuration of SRAM, flash memory, and DRAM. In order to process as much data as possible in the same space, an architecture that supports parallel processing units is usually provided. Such parallel architecture is a design method that provides high performance at low cost. However, it needs precise software techniques for instruction and data mapping on the parallel architecture. This paper proposes an instruction/data mapping method to support optimized parallel processing performance. The proposed method optimizes system performance by actively using hardware and software parallelism.

• Journal of Applied and Pure Mathematics
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• v.6 no.5_6
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• pp.327-336
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• 2024

Consider a (p, q) graph G = (V, E). Define $${\varrho}=\begin{cases}{\frac{p}{2}} & p\;{\text{is even}}\\{\frac{p-1}{2}} & p\;{\text{is odd}},\end{cases}$$ and Υ = {±1, ±2, . . ., ±ϱ} referred to as the label set. Let us consider a mapping 𝜑 : V → Υ, where, for every even p, distinct labels are assigned to the various elements of V in Υ, and for every odd p , distinct labels are assigned to the p - 1 elements of V in Υ, with a repeating label for the remaining one vertex. After that 𝜑 is referred to as a pair mean cordial labeling (PMC-labeling) if for every edge 𝜇𝜈 in G, there is a label for $\frac{{\varphi}({\mu})+{\varphi}({\nu})}{2}$ if 𝜑(μ) + 𝜑(ν) is even and $\frac{{\varphi}({\mu})+{\varphi}({\nu})+1}{2}$ if 𝜑(μ) + 𝜑(ν) is odd such that ${\mid}{\bar{\mathbb{S}}}_{{\varphi}_1}-{\bar{\mathbb{S}}}_{{\varphi}^c_1}{\mid}\,{\leq}1$ where ${\bar{\mathbb{S}}}_{{\varphi}_1}$ and ${\bar{\mathbb{S}}}_{{\varphi}^c_1}$ respectively denote the number of edges labeled with 1 and the number of edges not labeled with 1 respectively. A pair mean cordial graph (PMC-graph) is defined as a graph G with PMC-labeling. In this paper, we investigate the pair mean cordial labeling behavior of open ladder, triangular ladder, diagonal ladder, slanting ladder, circular ladder and diamond ladder.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.1
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• pp.72-77
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• 2014

There are two main technologies to implement cloud effect in flight simulator, cloud modeling using particle system and texture mapping. In former case, this approach may cause a low frame rate while unrealistic cloud effect is observed in latter case. To Solve this problem, in this paper, we propose how to apply fog effect into camera to display more realistic cloud effect with high frame rate. The proposed method is tested with massive terrain database environment through implemented software by using OpenSceneGraph. As a result, compared to texture mapping method, the degree of difference on frame rate is 1 or 2Hz while the cloud effect is significantly improved as realistic as particle system.

• Journal of Korea Spatial Information System Society
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• v.7 no.1 s.13
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• pp.39-52
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• 2005

GML (Geography Markup Language) has become the widely adopted standard for transport and storage of geographic information. So, various researches such as modeling, storage, query, and etc have been studied to provide the interoperability of geographic information in web environments. Especially, there are increased needs to store semi-structured data such as GML documents efficiently. Therefore, in this paper, we design and implement a GML repository to store GML documents on the basis of GML schema using spatial database system. GML Schema is converted into directed GML schema graph and the schema mapping technique from directed schema graph to spatial schema is presented. Also, we define the conversion rules on spatial schema to preserve the constraints of GML schema. GML repository using spatial database system is useful to provide the interoperability of geographic information and to store and manage enormous GML documents.

• Journal of the Korea Society of Computer and Information
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• v.25 no.10
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• pp.23-34
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• 2020

In this paper, we proposes a method to automatically construct SHACL schemas for RDF knowledge graphs(KGs) generated by Direct Mapping(DM). DM and SHACL are all W3C recommendations. DM consists of rules to transform the data in an RDB into an RDF graph. SHACL is a language to describe and validate the structure of RDF graphs. The proposed method automatically translates the integrity constraints as well as the structure information in an RDB schema into SHACL. Thus, our SHACL schemas are able to check integrity instead of RDBMSs. This is a consideration to assure database consistency even when RDBs are served as virtual RDF KGs. We tested our results on 24 DM test cases, published by W3C. It was shown that they are effective in describing and validating RDF KGs.

• Journal of the Korea Society of Computer and Information
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• v.29 no.10
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• pp.219-228
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• 2024

In this paper, we propose a method for constructing RDF knowledge graphs from objects in OOP. RML mapping has been the de-facto way of generating RDF graphs from heterogeneous data. However, the input to an RML mapping is limited to the data in files or databases. Our new RML implementation, designed to overcome the limit, has two differences compared to existing RML implementations. First, our implementation provides a new way to specify mapping rules in the form of special comments known as annotations in the source code. It is because existing works do not provide a means to refer to specific program elements to which the mapping rules will be applied. Second, our work provides mapping engine as a library, whereas the engines in existing studies runs in an independent process. Therefore, our mapping engine can be easily embedded in other applications to access in-memory objects to be mapped. In this system paper, we describe the proposed system in detail and present the results of RML test cases execution to confirm the usefulness of the system.

• The Journal of Korea Robotics Society
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• v.16 no.3
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• pp.179-188
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• 2021

Construction monitoring is one of the key modules in smart construction. Unlike structured urban environment, construction site mapping is challenging due to the characteristics of an unstructured environment. For example, irregular feature points and matching prohibit creating a map for management. To tackle this issue, we propose a system for data acquisition in unstructured environment and a framework for Intensity and Ambient Enhanced Lidar Inertial Odometry via Smoothing and Mapping, IA-LIO-SAM, that achieves highly accurate robot trajectories and mapping. IA-LIO-SAM utilizes a factor graph same as Tightly-coupled Lidar Inertial Odometry via Smoothing and Mapping (LIO-SAM). Enhancing the existing LIO-SAM, IA-LIO-SAM leverages point's intensity and ambient value to remove unnecessary feature points. These additional values also perform as a new factor of the K-Nearest Neighbor algorithm (KNN), allowing accurate comparisons between stored points and scanned points. The performance was verified in three different environments and compared with LIO-SAM.

• Journal of Applied and Pure Mathematics
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• v.5 no.1_2
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• pp.41-53
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• 2023

Let G = (V, E) be a (p, q) graph. Define $${\rho}=\{{\frac{2}{p}},\;{\text{{\qquad} if p is even}}\\{\frac{2}{p-1}},\;{{\text{if p is odd}}$$ and L = {±1, ±2, ±3, … , ±ρ} called the set of labels. Consider a mapping f : V ⟶ L by assigning different labels in L to the different elements of V when p is even and different labels in L to p-1 elements of V and repeating a label for the remaining one vertex when p is odd.The labeling as defined above is said to be a pair difference cordial labeling if for each edge uv of G there exists a labeling |f(u) - f(v)| such that ${\mid}{\Delta}_{f_1}-{\Delta}_{f^c_1}{\mid}{\leq}1$, where ${\Delta}_{f_1}$ and ${\Delta}_{f^c_1}$ respectively denote the number of edges labeled with 1 and number of edges not labeled with 1. A graph G for which there exists a pair difference cordial labeling is called a pair difference cordial graph. In this paper we investigate pair difference cordial labeling behaviour of Petersen graphs P(n, k) like P(n, 2), P(n, 3), P(n, 4).