• Industrial Engineering and Management Systems
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• v.13 no.2
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• pp.163-171
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• 2014

Under amazing increase in markets and certain demand on qualified service in the delivery system, global logistic optimization is becoming a keen interest to provide an essential infrastructure coping with modern competitive prospects. As a key technology for such deployment, we have been engaged in the practical studies on vehicle routing problem (VRP) in terms of Weber model, and developed a hybrid approach of meta-heuristic methods and the graph algorithm of minimum cost flow problem. This paper extends such idea to multi-depot VRP so that we can give a more general framework available for various real world applications including those in green or low carbon logistics. We show the developed procedure can handle various types of problem, i.e., delivery, direct pickup, and drop by pickup problems in a common framework. Numerical experiments have been carried out to validate the effectiveness of the proposed method. Moreover, to enhance usability of the method, Google Maps API is applied to retrieve real distance data and visualize the numerical result on the map.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.2
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• pp.174-182
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• 2007

Among the alternative energy sources, the solar energy is recognized as an important energy source and its application is increasing. Especially in future, the hybrid solar energy generation system with battery will be widely used as an independent distributed power generation system. In this paper, a solar power hybrid home generation system using a contactless power supply (CPS) that can transfer an electric power without any mechanical contact by using magnetic coupling instead of the power transfer by directly supplying the DC power to the home electric system is proposed. The proposed system consists of a ZVS boost converter, a half bridge LLC resonant converter and contact-less transformer.

• International Journal of Computer Science & Network Security
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• v.21 no.8
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• pp.238-246
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• 2021

The rapid rise of the Internet and social media has resulted in a large number of text-based reviews being placed on sites such as social media. In the age of social media, utilizing machine learning technologies to analyze the emotional context of comments aids in the understanding of QoS for any product or service. The classification and analysis of user reviews aids in the improvement of QoS. (Quality of Services). Machine Learning algorithms have evolved into a powerful tool for analyzing user sentiment. Unlike traditional categorization models, which are based on a set of rules. In sentiment categorization, Bidirectional Long Short-Term Memory (BiLSTM) has shown significant results, and Convolution Neural Network (CNN) has shown promising results. Using convolutions and pooling layers, CNN can successfully extract local information. BiLSTM uses dual LSTM orientations to increase the amount of background knowledge available to deep learning models. The suggested hybrid model combines the benefits of these two deep learning-based algorithms. The data source for analysis and classification was user reviews of Indian Railway Services on Twitter. The suggested hybrid model uses the Keras Embedding technique as an input source. The suggested model takes in data and generates lower-dimensional characteristics that result in a categorization result. The suggested hybrid model's performance was compared using Keras and Word2Vec, and the proposed model showed a significant improvement in response with an accuracy of 95.19 percent.

• The KIPS Transactions:PartC
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• v.10C no.5
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• pp.611-616
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• 2003

Recently, the HFC-CATV network stand in a substructure of superhighway information network. Because of sharing up to 500 of subscribes, the Collision Resolution Algorithm needs in the upstream channel of HFC-CATV network. In order to provide Quality of Service (QoS) to users with real-time data such as voice, video and interactive service, the research of Collision Resolution Algorithm must include an effective priority scheme. In IEEE 802.14, the Collision Resolution Algorithm has high request delay because of static PNA(Priority New Access) slots structure and different priority traffics with the same probability. In order to resolve this problem, this paper proposed dynamic priority collision resolution algorithm with ternary tree algorithm. It has low request delay according to an increase of traffic load because high priority traffic first resolve and new traffic content with different probability. In the result of the simulation, it demonstrated that the proposed algorithm needs lower request delay than that of ternary tree algorithm with static PNA slots structure.

• Journal of Korea Spatial Information System Society
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• v.5 no.1 s.9
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• pp.83-89
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• 2003

The GIS which is analysis of the real world to construction of 3D virtual city develop s in rapid growth. 3D virtual city is simulated by use of a GIS, Computer graphics, virtual reality and Spatial database. In this paper 3D topographical basemap which have the geographic coordinate of world was constructed by digital map. And build the Cyber city with combining the building that have elevation and 3D topographical basemap. By using server/client system for the cyber city. 3D cyber city web service implemented. We proposed the hybrid base web service method rather than the image or vector base web service. By the spatial and attribute search in the 3D Cyber City, overcome the existing simple visibility of Web 3D technology, and exhibited development direction to the Web 3D GIS.

• Journal of Software Assessment and Valuation
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• v.16 no.2
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• pp.53-62
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• 2020

In the end-user domain of an IoT environment, there are more and more intelligent M2M devices that provide resources to create and share application services. Therefore, it can be very useful to manage trust by transferring the role of the existing centralized service provider to end users in a P2P environment. However, in a decentralized M2M computing environment where end users independently provide or consume services, mutual trust building is the most important factor. This is because malicious users trying to build malfunctioning services can cause security problems in M2M computing environments such as IoT. In this paper, we provide an integrated analysis and approach for trust evaluation of M2M application services, and an optimized trust evaluation model that can guarantee reliability among users of the M2M community.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1781-1785
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• 2004

In existing factory, robot has less necessity that consider person. However, person should be considered at design and use of service robot. To service robot can be used in everyday life along with this, more functions are required. Specially, medical service robot needs function that is intelligence function. Especially, to help patient brain disease patient (cerebral hemorrhage, cerebral infarction, imbecility), gait assistance Mobile robot consider ergonomic element necessarily. In order to develop the medical support service robot, the ergonomic design should be considered. This robot ergonomic design parameters are treated in ("evelopment of Medical Support Service Robot Using Ergonomic Design" 2003, ICASS) Fig2 show this Robot. In this study, navigation algorithm of walk assistance robot is analyzed in ergonomic view. Navigation algorithm of Mobile robot can divide by two patterns. Traditional derivative method has shortcoming in dynamic environment. Reactive method is result that react excellently in dynamic environment. However, number of behavior function is limited. So hybrid navigation algorithm was proposed by the alternative way. We consider enough user specificity at navigation algorithm application of gait assistance robot.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2033-2038
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• 2003

This paper describes an integrated navigation strategy for the autonomous service robot PSR. The PSR is under development at the KIST for service tasks in indoor public environments. The PSR is a multi-functional mobile-manipulator typed agent, which works in daily life. Major advantages of proposed navigation are as follows: 1) Structured control architecture for a systematic integration of various software modules. A Petri net based configuration design enables stable control flow of a robot. 2) A range sensor based generalized scheme of navigation. Any range sensor can be selectively applied using the proposed navigation scheme. 3) No need for modification of environments. (No use of artificial landmarks.) 4) Hybrid approaches combining reactive behavior as well as deliberative planner, and local grid maps as well as global topological maps. A presented experimental result shows that the proposed navigation scheme is useful for mobile service robot in practical applications.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.8
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• pp.1996-2015
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• 2023

High-definition (HD) maps can provide precise road information that enables an autonomous driving system to effectively navigate a vehicle. Recent research has focused on leveraging semantic segmentation to achieve automatic annotation of HD maps. However, the existing methods suffer from low recognition accuracy in automatic driving scenarios, leading to inefficient annotation processes. In this paper, we propose a novel semantic segmentation method for automatic HD map annotation. Our approach introduces a new encoder, known as the convolutional transformer hybrid encoder, to enhance the model's feature extraction capabilities. Additionally, we propose a multi-level fusion module that enables the model to aggregate different levels of detail and semantic information. Furthermore, we present a novel decoupled boundary joint decoder to improve the model's ability to handle the boundary between categories. To evaluate our method, we conducted experiments using the Bird's Eye View point cloud images dataset and Cityscapes dataset. Comparative analysis against stateof-the-art methods demonstrates that our model achieves the highest performance. Specifically, our model achieves an mIoU of 56.26%, surpassing the results of SegFormer with an mIoU of 1.47%. This innovative promises to significantly enhance the efficiency of HD map automatic annotation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.11a
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• pp.162-163
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• 2011

This paper presents the system dynamics methodology for modeling and control the production/inventory system. Under system dynamics point of view, we can apply some production/inventory policies as if we use the control laws for dynamics systems, then the behavior of system is analyzed and evaluated to improve the performance of production/inventory system. We also utilize the hybrid modeling method for the dynamic of production system with the combination of Matlab/Simulink and Matlab/Sateflow. Finally, the numerical simulation results are carried out in Matlab/Simulink environment and compare with the results from other works. It is shown that our approach can obtain some good performances (such as operational cost, stability of inventory, customer service level).