• Journal of Platform Technology
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• v.10 no.3
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• pp.51-59
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• 2022

Machine learning, which has recently innovatively developed, has become an important technology that can solve various optimization problems. In this paper, we introduce the latest research papers that solve the problem of channel sharing in heterogeneous networks using machine learning, analyze the characteristics of mainstream approaches, and present a guide to future research directions. Existing studies have generally adopted Q-learning since it supports fast learning both on online and offline environment. On the contrary, conventional studies have either not considered various coexistence scenarios or lacked consideration for the location of machine learning controllers that can have a significant impact on network performance. One of the powerful ways to overcome these disadvantages is to selectively use a machine learning algorithm according to changes in network environment based on the logical network architecture for machine learning proposed by ITU.

• International Journal of Computer Science & Network Security
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• v.24 no.2
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• pp.67-78
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• 2024

Software-Defined Networking (SDN) is a new emerging networking paradigm that has adopted a logically centralized architecture to increase overall network performance agility and programmability. Combining network virtualization with SDN will guarantees for combined advantages of improved flexibility and network performance. Combining SDN with hypervisors divides the network physical resources into several logical transparent and isolated virtual SDN network (vSDN), where each has its virtual controller. However, SDN hypervisors bring several advantages as well as several challenges to its network operators as for the virtual appliances, their efficient placement, assurance of network performance is mandatory, and their dynamic instantiation with their migration. In this article, we provide a brief and concise review of network virtualization along with its implementation in the SDN network. SDN hypervisors types are discussed, and taxonomy is provided to demonstrate the importance of hypervisors in SDN. A comparison of SDN hypervisors is performed to elaborate on the vital hypervisor software along with their features, and different challenges are discussed faced by the SDN network. A framework is proposed to add combined functionalities of hypervisors to create a more effective and efficient virtual system. The purpose of the framework is to increase network performance through proper configuration of resources, software, control plane isolation functions with defined rules and policies.

• Steel and Composite Structures
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• v.50 no.1
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• pp.77-87
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• 2024

In this study, the two-dimensional crack problem was investigated by using the finite element method (FEM)-based ANSYS package program and the artificial neural network (ANN)-based multilayer perceptron (MLP) method. For this purpose, a half-infinite functionally graded (FG) layer with a crack pressed through two rigid blocks was analyzed using FEM and ANN. Mass forces and friction were neglected in the solution. To control the validity of the crack problem model exercised, the acquired results were compared with a study in the literature. In addition, FEM and ANN results were checked using Root Mean Square Error (RMSE) and coefficient of determination (R²), and a well agreement was found. Numerical solutions were made considering different geometric parameters and material properties. The stress intensity factor (SIF) was examined for these values, and the results were presented. Consequently, it is concluded that the considered non-dimensional quantities have a noteworthy influence on the SIF. Also FEM and ANN can be logical alternative methods to time-consuming analytical solutions if used correctly.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.4
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• pp.90-104
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• 2007

Landmarks like high-rise building are one of the important elements for the enhancement of city identity and provides the hierarchy of city streets, playing a central and symbolic role in cities. Research on physical attribute of landmarks, such as height, distance, location and shape, which are suitable for a city scale, can help a city create a distinct image and maintain comprehensible structure. To achieve this purpose, it is necessary to understand the spatial and cognitive characteristics of a landmark for the establishment and management of it. The results of this study can be summarized as follows: 1. The level of representativeness of a landmark increases in proportion to the degree of cognitive intensity on it. The relation between representativeness and cognitive intensity can be explained as the log-function as follows: Log(the number of people who respond "It has representativeness")=$-1.2579+1.5908{\times}$(cognitive intensity); 2. There are a few differences based on the attributes of respondents: while gender has no distinct influence, residential period and age show statistically meaningful influence on cognitive intensity of a vertical landmark Cognitive intensity of an individual landmarks especially, differs according to the class of main users. Because of frequent changes in occupation or employment, respondents consider the distance from a residential area more important than the distance from a working area in evaluating cognitive intensity of landmarks; 3. landmark can be classified into two kinds: a district landmark and an urban landmark A district landmark is closely connected with physical attributes of the landmark itself, such as distance, size and height. An urban landmark is mainly related to cognitive attributes such as the image and identity of a city as a whole. As a result, the landmark analysis data in this research provides spatial order and identity in a city. It is difficult to establish and reinforce the image of a city as a single element ike a landmark. However, withy steady follow-up research, this study could be seen as a systematic and logical model to improve urban landscape and image.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.1
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• pp.35-45
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• 2011

The landscape of Seoul was dynamically changed and developed with the rapid post-war economic growth. Seoul city designated a height regulation district to preserve and manage the city landscape and protect it from haphazard construction. The designation of a maximum height regulation district has obvious purpose and simple regulations which makes the implementation and management easy to apply yet the altitude restriction lacks an objective basis for its enforcement. Many studies have been done and the current uniform height regulation requires more objective and logical guidelines. This study selected the Bukhan Mountain area, a National Park designated to protect the environment, to present a new landscape height guideline to minimize environmental degradation and to harmonize the artificial and natural landscapes of the area. Document research was done to identify the regulation types(absolute height regulation, view line regulation, oblique line restriction regulation) and principles for height regulation district establishment, acknowledge the current status and issues of the Bukhan Mountain area's maximum height regulation district. Gangbuk-Gu was chosen as the site and survey was conducted on outstanding view points and view corridors of residents. From document research, an appropriate landscape height guideline was selected and applied to Gangbuk-Gu. According to the guideline, suitable heights for buildings were suggested. These were then applied to three-dimensional simulations and a final guideline was suggested.

• Journal of KIISE:Software and Applications
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• v.34 no.8
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• pp.731-742
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• 2007

Self-growing software is a software system that has the capability of evolving its functionalities and configurations by itself based on dynamically monitored situations. Self-growing software is especially necessary for intelligent service robots, which must have the capability to monitor their surrounding environments and provide appropriate behaviors for human users. However, it is hard to anticipate all situations that robots face with, and it is hard to make robots have all functionalities for various environments. In addition, robots have limited internal capacity. To support self-growing software for intelligent service robots, we are developing a cell-based distributed repository system that allows robots and developers transparently to share robot functionalities. To accomplish the creation of evolutionary repositories, we invented the concept of a cell, which is a logical group of distributed repositories based upon the functionalities of components. In addition, a cell can be used as a unit for the evolutionary growth of the components within the repositories. In this paper, we describe the requirements and architecture of the cell-based repository system for self-growing software. We also present a prototype implementation and experiment of the repository system. Through the cell-based repositories, we achieve improved performance of self-growing actions for robots and efficient sharing of components among robots and developers.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.2
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• pp.78-89
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• 2009

The purpose of this study is to build fundamental data for the classification of landscape type as a base for landscape planning and management practices. To do this, prior dissertations and landscape plan reports were analyzed, which presented the classification criteria for landscape type. Based on this, classification criteria for landscape type which could be usable in zoning ordinances has been suggested. The result is as follows: Firstly, in landscape analysis and assessment study based on ecological and formal aesthetic models, landscape type is classified by the character of the landscape element. Secondly, there is no logical classification of landscapetype in urban landscape planning according to mixed use of landscape type for analysis and planning. It is therefore difficult to identify the object of landscape planning, which is intimately linked with the shortage of concrete practice for landscape management. In connection with this issue, classification criteria for landscape type are suggested based on utility in landscape planning. This could be divided into internal criteria and external criteria. The former are land-use, topographical characteristics, characteristics of the view object, and landscape elements while the latter are viewpoint, distance to view object, and urban form. Applying the landscape type classified by the criteria suggested in this paper, it is possible to manage an entire urban area. In addition, landscape type could be reference data for operating a zoning system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.2
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• pp.108-113
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• 2003

Research results have demonstrated that conventional client-server databases have scalability problem in the presence of many concurrent clients. The multi-tier architecture that exploits similarities in clients' object access behavior partitions clients into logical clusters according to their object request pattern. As a result, object requests that are served inside the clusters, server load and request response time can be optimized. Management of clustering by utilizing clients' access pattern-based is an important component for the system's goal. Off-line methods optimizes the quality of the global clustering, the necessary cost and clustering schedule needs to be considered and planned carefully in respect of stable system's performance. In this paper, we propose methods that detect changes in access behavior and optimize system configuration in real time. Finally this paper demonstrates the effectiveness of on-line change detection and results of experimental investigation concerning reconfiguration.

• Journal of Environmental Health Sciences
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• v.43 no.4
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• pp.307-313
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• 2017

Objectives: Chemicals derived from various environment media contaminates food across the food supply chain. In Korea, levels of contaminants in food have been sporadically measured by monitoring programs of different government agencies. There is difficulty with data compilation and integrated analysis across media. Therefore, the aim of this study was to propose an overall integrated database and analytical platform design for the 'ECO-FOOD NET (Environmental COntaminant reduction platform for FOOD through an interagency collaboration NETwork)', a tool to support the reduction of environmental contaminants in food. Methods: We developed a new data structure and standardized protocols for the compilation of integrated data. In addition, we conducted subject-oriented logical and physical relational database modeling and created the architecture design of the platform. Results: We established a standardized code system related to exposure media and route, analysis method and food matrix. In addition, we designed the seven software modules of 'About the System', 'Introduction to Interagency Work', 'Media-Chemicals Profiles', 'Method Bank', 'Monitoring Data Base', 'Integrated Media Analysis', and 'Risk-Benefit Analysis'. Conclusions: This study will contribute to decision-making as a tool for executing risk management, such as sustainable reduction policies of contaminants in food.

• Journal of Internet Computing and Services
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• v.9 no.3
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• pp.9-24
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• 2008

In this paper, we describes the design of software architecture supporting for healthcare context information service platform based on multi agent in home environment. In this platform, the DOGF supports the execute object and healthcare sensors and device's logical services grouping. JADE framework can support mobility in heterogeneous environment. The multi agents on platform order to support a healthcare context information service it will be able to divide. An agent collects an environment information from distributed devices. Another an agent follows mobile-device specific and it does a different service. And an agent where it manages like this. The mobile-proxy&agent is an interface part between DOGF and JADE, support data interchange or mobility pattern. For DOGF and JADE to provide healthcare context information service, we describes the design of multi agent software platform and multi agent classification by services. Finally we showed the system environments which is physical environments and prototype based on platfonn for healthcare context information services.