• Journal of Korea Society of Industrial Information Systems
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• v.23 no.3
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• pp.59-71
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• 2018

Social media has immense popularity among all services today. Data from social network services (SNSs) can be used for various objectives, such as text prediction or sentiment analysis. There is a great deal of Korean and English data on social media that can be used for sentiment analysis, but handling such huge amounts of unstructured data presents a difficult task. Machine learning is needed to handle such huge amounts of data. This research focuses on predicting Korean and English sentiment using deep forward neural network with a deep learning architecture and compares it with other methods, such as LDA MLP and GENSIM, using logistic regression. The research findings indicate an approximately 75% accuracy rate when predicting sentiments using DNN, with a latent Dirichelet allocation (LDA) prediction accuracy rate of approximately 81%, with the corpus being approximately 64% accurate between English and Korean.

• International journal of advanced smart convergence
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• v.5 no.1
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• pp.34-46
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• 2016

Networked Control System (NCS) has evolved in the past decade through the advances in communication technology. The problems involved in NCS are broadly classified into two categories namely network issues due to network and control performance due to system network. The network problems are related to bandwidth allocation, scheduling and network security, and the control problems deal with stability analysis and delay compensation. Various delays with variable length occur due to sharing a common network medium. Though most delays are very less and mostly neglected, the network induced delay is significant. It occurs when sensors, actuators, and controllers exchange data packet across the communication network. Networked induced delay arises from sensor to controller and controller to actuator. This paper presents an adaptive delay compensation process for efficient control. Though Smith predictor has been commonly used as dead time compensators, it is not adaptive to match with the stochastic behavior of network characteristics. Time delay adaptive compensation gives an effective control to solve dead time, and creates a virtual environment using the plant model and computed delay which is used to compensate the effect of delay. This approach is simulated using TrueTime simulator that is a Matlab Simulink based simulator facilitates co-simulation of controller task execution in real-time kernels, network transmissions and continuous plant dynamics for NCS. The simulation result is analyzed, and it is confirmed that this control provides good performance.

• ETRI Journal
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• v.38 no.3
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• pp.444-454
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• 2016

Voice service is very demanding in cognitive radio networks (CRNs). The available spectrum in a CRN for CR users varies owing to the presence of licensed users. On the other hand, voice packets are delay sensitive and can tolerate a limited amount of delay. This makes the support of voice traffic in a CRN a complicated task that can be achieved by devising necessary considerations regarding the various network functionalities. In this paper, the support of secondary voice users in a CRN is investigated. First, a novel packet scheduling scheme that can provide the required quality of service (QoS) to voice users is proposed. The proposed scheme utilizes the maximum packet transmission rate for secondary voice users by assigning each secondary user the channel with the best level of quality. Furthermore, an analytical framework developed for a performance analysis of the system, is described in which the effect of erroneous spectrum sensing on the performance of secondary voice users is also taken into account. The QoS parameters of secondary voice users, which were obtained analytically, are also detailed. The analytical results were verified through the simulation, and will provide helpful insight in supporting voice services in a CRN.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.863-870
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• 2002

The current class scheduling has difficulties in reflecting students' preferences for the classes that they want to take and forecasting the demands of classes. Also, it is usually a repetitive and tedious work to allocate classes to limited time and cesourres Although many research studios in task allocation and meeting scheduling intend to solve similar problems, they have limitations to be directly applied to the class-scheduling problem. In this paper. a class scheduling system using multi agents-based negotiation is suggested. This system consists of student agents, professor agents and negotiation agents each agent arts in accordance with its respective human user's preference and performs the repetitive and tedious process instead of the user The suggested system utilizes negotiation cost concept to derive coalition in the agent's negotiation. The negotiation cost is derived from users' bidding prices on classes, where each biding price represents a user's preference on a selected class. The experiments were performed to verify the negotiation model in the scheduling system. The result of the experiment showed that it could produce a feasible scheduling solution minimizing the negotiation cost and reflecting the users' performance. The performance of the experiments was evaluated by a class success ratio.

• Journal of the Ergonomics Society of Korea
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• v.32 no.5
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• pp.459-467
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• 2013

Objective: The aim of this study is to review the studies on job rotation with various points of view and to classify the studies considering the approach methods. Background: Various work interventions were carried in order to prevent the work-related musculoskeletal disorders(WMSDs) and job rotation was considered as one of the simple and effective methods. Method: Previous studies were systematically collected with the combination of keywords such as job, task, rotation, allocation, line balancing, etc. Collected studies were classified into three categories: field study, laboratory study and optimization approach study. Results: Field studies showed that most studies focused on the evaluation of the factors causing the musculoskeletal disorder. Moreover, the effect of job rotation could be hard to identify because it required a long-period close observation. Laboratory studies covered only simple aspects of tasks or movements. Optimization approach studies showed the systematic approach to establish the job rotation scheme though many limitation and assumptions were adopted. Conclusion: This study collected and classified the previous studies on job rotation and presented the different approaches across various research areas. Application: The results of this study could help the practitioner and ergonomist how to establish the job rotation scheme.

• The Journal of Korean Academic Society of Nursing Education
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• v.27 no.3
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• pp.240-250
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• 2021

Purpose: The aim of this study is to analyze the research trends of articles on just graduated Korean nurses during the past 10 years for exploring strategies for clinical adaptation. Methods: The topics of new graduate nurses were extracted from 110 articles that have been published in Korean journals between January 2010 and July 2020. Abstracts were retrieved from 4 databases (DBpia, RISS, KISS and Google scholar). Keywords were extracted from the abstracts and cleaned using semantic morphemes. Network analysis and topic modeling were performed using the NetMiner program. Results: The core keywords included 'education', 'training', 'program', 'skill', 'care', 'performance', and 'satisfaction'. In recent articles on new graduate nurses, three major topics were extracted by Latent Dirichlet Allocation (LDA) techniques: 'turnover', 'adaptation', 'education'. Conclusion: Previous articles focused on exploring the factors related to the adaptation and turnover intentions of new graduate nurses. It is necessary to conduct further research focused on various interventions at the individual, task, and organizational levels to improve the retention of new graduate nurses.

• The Journal of Korean Physical Therapy
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• v.34 no.5
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• pp.224-233
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• 2022

Purpose: In Japan, the Long-Term Care Insurance Act has stipulated visiting rehabilitation since 2000. This study aimed to identify the actual conditions of visiting rehabilitation in Japan through a literature review of reports published by the Japanese government. Methods: This literature review was conducted on eight articles among various government reports on the topic of the actual conditions of visiting rehabilitation. These reports were published by the Ministry of Health, Labor and Welfare of Japan based on their own investigations or reports from an external agency entrusted with the task, and were issued between 2000 and 2021. Results: The characteristics of the visiting rehabilitation offices, their number, manpower allocation, the number of users, and their visits to each office were identified. Also, the characteristics of the users, number of users, age and required degree of long-term care, causative disease, and required medical care were identified. To evaluate the actual status of the visiting rehabilitation service, the service use time, frequency, period of use, intervention by doctors and the degree of such intervention, therapist's service content, visitors' address before the use of the service, reason, and timing of the service introduction, evaluation of the service effectiveness, combination of services and transfer destination after termination, and status after service termination were checked. Conclusion: Based on the Japanese experience where visiting rehabilitation was introduced and applied to long-term care insurance, it would be meaningful to review the factors that required benchmarking among the Japanese service models while designing a similar model in Korea.

• Journal of Internet Computing and Services
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• v.23 no.5
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• pp.17-23
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• 2022

Network slicing is a promising paradigm and significant evolution for adjusting the heterogeneous services based on different requirements by placing dynamic virtual network functions (VNF) forwarding graph (VNFFG) and orchestrating service function chaining (SFC) based on criticalities of Quality of Service (QoS) classes. In system architecture, software-defined networks (SDN), network functions virtualization (NFV), and edge computing are used to provide resourceful data view, configurable virtual resources, and control interfaces for developing the modified deep reinforcement learning agent (MDRL-A). In this paper, task requests, tolerable delays, and required resources are differentiated for input state observations to identify the non-critical/critical classes, since each user equipment can execute different QoS application services. We design intelligent slicing for handing the cross-domain resource with MDRL-A in solving network problems and eliminating resource usage. The agent interacts with controllers and orchestrators to manage the flow rule installation and physical resource allocation in NFV infrastructure (NFVI) with the proposed formulation of completion time and criticality criteria. Simulation is conducted in SDN/NFV environment and capturing the QoS performances between conventional and MDRL-A approaches.

• Journal of Advanced Navigation Technology
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• v.27 no.1
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• pp.1-7
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• 2023

Mission autonomy system should be embedded on UAV (Unmanned Aerial Vehicle) for mosaic warfare where UAVs autonomously assign tasks to themselves. UxAS (Unmanned x-systems Autonomy Service) proposed by Air Force Research Laboratory is mission autonomy system for unmanned platforms. UxAS has extensible structure composed of numerous module services. However, UxAS can conduct mission autonomy process only when an operator sends an autonomy request. In this paper, We analyze the process of mission autonomy in UxAS, and propose an improved structure of UxAS where mission autonomy process is autonomously triggered by situation awareness service without the request of the operator. The proposed process was validated by simulation.

• Journal of Korean Academy of Nursing
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• v.53 no.6
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• pp.584-596
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• 2023

Purpose: This study aimed to explore the perspectives of frontline nurses working during the novel coronavirus disease 2019 (COVID-19) pandemic. Methods: An online qualitative study was conducted using a pragmatic approach. The data were collected in August 2021. Registered Korean nurses who provided direct nursing care to patients with confirmed COVID-19 were eligible for this study. An online survey was used to gather free-text data, which were then analyzed using machine-based network analysis and summative content analysis. Results: The analysis examined the responses of 126 participants and led to the identification of six prominent themes. These themes were further classified into three distinct levels: personal, task, and organizational. The identified themes are as follows: "collapse of personal life," "being overwhelmed by the numerous roles required," "personal protective equipment was sufficiently provided, but that is not enough," "changes in interprofessional collaboration," "inappropriate workforce management," and "diverted allocation of healthcare services and resources." Conclusion: Our findings highlight areas for improvement in resources, systems, and policies to enhance preparedness for future pandemics.