• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.46 no.3
• /
• pp.23-31
• /
• 2023

In this study, a smart bench was developed and researched smart benches that can contribute to user convenience and satisfaction by installing them in parks, bus stops, and tourist attractions in line with the rapidly changing construction of smart cities. The smart bench is automatically operated by the control system according to the external temperature and provides additional functions such as charging, lighting, and advertising to improve general bench functions as well as heating in winter and cooling in summer, making it suitable for smart urbanization. The developed smart bench is designed to be strong enough to withstand loads of about 2,500 N. It minimizes the visible parts such as assembled bolts and 220V power supply wires, It can also give aesthetic effects. The development was carried out with the aim of waterproofing and dustproofing of IP44 grade in accordance with the climate of Republic of Korea, which has four seasons, and it is advantageous for long-term use because the paint was selected for the weather ability (discoloration) grade 3 or higher. If smart bench is commercialized, it is believed that various options can be provided to the smart bench market, where buyers had few product options, as the parts were developed in an assembled type so that all functions can be responded in an optional form according to the installation environment and the buyer's budget.

• Journal of information and communication convergence engineering
• /
• v.20 no.4
• /
• pp.250-258
• /
• 2022

The emerging scope of the Internet-of-Things (IoT) has piqued the interest of industry and academia in recent times. Therefore, security becomes the main issue to prevent the possibility of cyberattacks. Jamming attacks are threads that can affect performance and cause significant problems for IoT device. This study explores a smart jamming attack (coalition attack) in which the attackers were previously a part of the legitimate network and are now back to attack it based on the gained knowledge. These attackers regroup into a coalition and begin exchanging information about the legitimate network to launch attacks based on the gained knowledge. Our system enables jammer nodes to select the optimal transmission rates for attacks based on the attack probability table, which contains the most probable link transmission rate between nodes in the legitimate network. The table is updated constantly throughout the life cycle of the coalition. The simulation results show that a coalition of jammers can cause highly successful attacks.

• Journal of Power Electronics
• /
• v.11 no.2
• /
• pp.211-217
• /
• 2011

The dynamic response of a multi-MW wind turbine to a sudden change in wind speed is usually slow, because of the slow pitch control system. This could cause a large excursion of the rotor speed and an output power over the rated. A feedforward pitch control can be applied to minimize the fluctuations of these parameters. This paper introduces the complete design steps for a feedforward pitch controller, which consist of three stages, i.e. the aerodynamic torque estimation, the 3-dimensional lookup table for the wind seed estimation, and the calculation of the feedforward pitch amount. The effectiveness of the feedforward control is verified through numerical simulations of a multi-MW wind turbine.

• Journal of the Korean Society of Systems Engineering
• /
• v.1 no.2
• /
• pp.43-48
• /
• 2005

This paper describes the results of applying States and Modes Analysis, one of the requirements analysis techniques, to the development requirements of flight control software for Smart UAV. State/mode table enabled us to investigate various operation and design concepts, and as a result essential requirements for flight control software were established without omitting necessary requirements. Through the use of scenario-specific state transition diagrams, dynamic behaviours and control/response interfaces between each state and mode could been clearly identified, which made it possible to establish requirements related to dynamic behaviours of states and modes which are essential to the design of flight control software.

• Journal of Korea Society of Industrial Information Systems
• /
• v.17 no.3
• /
• pp.105-114
• /
• 2012

Various RFID-based smart-walk systems have been developed for guiding disabled people. The system sends appropriate message whenever the disabled people arrived at a specific point. We propose universal design concept and optimization techniques for the smart-walk systems. Universal design concept can be adopted for supporting various kinds of disabled such as a blind person, a hearing-impaired person, or a foreigner in a system. It can be supported by storing appropriate messages set in the message database table depending on the kinds of the disabled. System optimization can be done by analyzing operational log(stream) data accumulated in the system. Useful information can be extracted by analyzing or mining the accumulated operational log data. We show various analysis results from the operational log data.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.4
• /
• pp.569-574
• /
• 2013

With probably too many smart phone applications downloaded, it is sometimes frustrating to find frequently used applications quickly. In this paper, we propose a learning application that learns what applications a user frequently uses and match them with several signals that user designated. This learning applications uses ART2 algorithm that is good for stable real-time learning. By executing this learning application, a user simply chooses an application that is to be quickly searched and then draw a figure that would match the designated application at the upper left corner of our learning application. The proposed learning application transforms the background with 0's and the figure with 1's and normalize them to be used as inputs for ART2 and ART2 does clustering to setup a match table between applications and figures. After learning, a user simply draws a figure to execute one's frequently used application.

• Journal of the Korea Society of Computer and Information
• /
• v.17 no.3
• /
• pp.33-40
• /
• 2012

Recently, to enhance the quality and efficiency of health care services, smart health care services utilizing a smart phone and tablet pc are mainly being introduced into the large hospital and the interest for personal health record service which manages personal medical information utilizing PC and smart phone and technology development is actively underway. In order to build a next generation hospital information systems, the interoperability of data between the different hospital information systems and UX consistency between the various user devices must be assured. Therefore, in this paper, medical information standard and the study for improving the performance is conducted to design the gateway system which converting and integrating the medical information under multi-platform environment. In this paper, CCR standard is adapted to the mapping method between the data which is the key feature of the gateway system and design the system utilizing multi-table-based mapping method. To evaluate the performance of the system, experiment was done and the result has been improved approximately 20 percent for response rate.

• Journal of the Korea Society of Computer and Information
• /
• v.14 no.10
• /
• pp.233-240
• /
• 2009

In this paper we made the serious game learning multiplication table to be evolved. The serious game is to induce the interest of the learner. This program has an interaction form which reflects the intention of the user and using this program a learner to learn the multiplication table as teacher's location are training a program that are seen as the abata and came to be that learner is smart. A study ability to be evolved used an back propagation neural networks. But we improved a study speed using divided weight table concept. The engine is studied perfectly in 60~80 times training. The learning rate increase to various non-monotonic functional form not to do a mechanical rise. And the learning rate is similar with the study ability of the human.

• Journal of Electrical Engineering and Technology
• /
• v.13 no.4
• /
• pp.1759-1768
• /
• 2018

The energy density, power density and ohm resistance of battery change significantly as results of battery aging, which lead to decrease in the accuracy of the equivalent model. A parameter identification method of the equivale6nt circuit model with 3 R-C branches based on the test database of battery life cycle is proposed in this paper. This database is built on the basis of experiments such as updating of available capacity, charging and discharging tests at different rates and relaxation characteristics tests. It can realize regular update and calibration of key parameters like SOH, so as to ensure the reliability of parameters identified. Taking SOH, SOC and T as independent variables, lookup table method is adopted to set initial value for the parameter matrix. Meanwhile, in order to ensure the validity of the model, the least square method based on variable forgetting factor is adopted for optimizing to complete the identification of equivalent model parameters. By comparing the simulation data with measured data for charging and discharging experiments of Li-ion battery, the effectiveness of the full life cycle database and the model are verified.

• International Journal of Internet, Broadcasting and Communication
• /
• v.13 no.4
• /
• pp.121-128
• /
• 2021

In order to design a real time big data collection and analysis system of manufacturing data in a smart factory, it is important to establish an appropriate wired/wireless communication system and protocol. This paper introduces the latest communication protocol, OPC-UA (Open Platform Communication Unified Architecture) based client/server function, applied user interface technology to configure a network for real-time data collection through IoT Integration. Then, Database is designed in MES (Manufacturing Execution System) based on the analysis table that reflects the user's requirements among the data extracted from the new cutting process automation process, bush inner diameter indentation measurement system and tool monitoring/inspection system. In summary, big data analysis system introduced in this paper performs SPC (statistical Process Control) analysis and visualization analysis with interface of OPC-UA-based wired/wireless communication. Through AI learning modeling with XGBoost (eXtream Gradient Boosting) and LR (Linear Regression) algorithm, quality and visualization analysis is carried out the storage and connection to the cloud.