• Journal of Advanced Navigation Technology
• /
• v.17 no.6
• /
• pp.712-719
• /
• 2013

This paper studies the security module for the reliable transmission of the meter reading and the control data between the remote terminals and the upper server-side in smart water grid. The proposed security module was implemented to make it attachable to the remote terminal without security function. In particular, unlike the smart grid of electric field, the low power is considered due to the use of battery power in the smart water grid, and the ARIA-GCM-128 symmetric key method is adopted taking into the account that the damp and constrictive environments by the installed meter location in the underground occur a communication obstacle on building of the large-scale network system. The encryption module of this paper was devised to ensure the safety between the reading data on the terminal and the control data from the upper server, and secure the stability of the remote meter reading system by taking protection against an arbitrary alteration or modification.

• Journal of Advanced Navigation Technology
• /
• v.26 no.3
• /
• pp.172-178
• /
• 2022

In this paper, water meter AMR(automatic meter reading), one of the core technologies of smart water grid, using LoRa IoT network is studied. The main content of the research is to develop the network system and show the test results that one PC server receives the readings of water meters from multiple households through LoRa communication and stores them in the database, and at the same time sends the data to the web server database through internet. The system also allows users to monitor the meter readings using their smartphones. The hardware and firmware of the main board of the digital water meter are developed. For a PC server program, MDMS(meter data management system) is developed using Visual C#. The app program running on the user's smartphone is also developed using Android Studio. By connecting each developed parts, the total network system is mounted on a flow test bench in the laboratory and tested. For the fields test, 5 places around the university are selected and the transmission distances are tested. The test result show that the developed system can be applied into the real field. The developed system can be expanded to various social safety nets such as monitoring the living alone or elderly with dementia.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.8
• /
• pp.18-25
• /
• 2020

With the development of water internet technology, data communication between objects is expanding. Research related to data communication technology between vehicles that incorporates related technologies into vehicles has been actively conducted. For data communication between mobile terminals, data stability, reliability, and real-time performance must be guaranteed. The 5 GHz Wi-Fi band, which is advantageous in bandwidth, communications speed, and wireless saturation of the wireless network, was selected as the data communications network between vehicles. This study analyzes how to design and implement a 5 GHz Wi-Fi network in a vehicle network. Considering the characteristics of the mobile communication terminal device, a continuous variable communications structure is proposed to enable high-speed data switching. We simplify the access point access procedure to reduce the latency between wireless terminals. By limiting the Transmission Control Protocol Internet Protocol (TCP/IP)-based Dynamic Host Configuration Protocol (DHCP) server function and implementing it in a broadcast transmission protocol method, communication delay between terminal devices is improved. Compared to the general commercial Wi-Fi communication method, the connection operation and response speed have been improved by five seconds or more. Utilizing this method can be applied to various types of event data communication between vehicles. It can also be extended to wireless data-based intelligent road networks and systems for autonomous driving.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.29 no.6
• /
• pp.754-760
• /
• 1996

Effects of washing and additives on the texture of squid surimi gel which has been known to hard to gelation due to high protease activities and many water solubles were studied by SDS-PAGE, compression test, jelly strength and transmission electron microscopy analysis (TEM). Myosin (205 kDa) heavy chain was the major protein in water soluble fractions. It was impossible to make a gel after washing of the minced squid meat. These results suggested that squid (Todarodes pacificus) minced meat does not need a washing for good jelly products. $3.0\%$ of bovine plasma protein (BPP) produced the hardest gel ($16\%$ harder than the control) among the additives including egg white (EW), potato extracts (PE) and transglutaminase-K (TG-K) by compression test (P>0.05). Microstructure of control, $2\%$ EW and $4\%$ TG-K treated gels showed a sponge-like structure with more vacant space. Gels containing $3\%$ BPP formed the most rigid and arranged networks. Those results indicates that poor gel-network formation Was due to the degradation of myofibrillar proteins by proteases contained in the minced meat, which result in non-interlinkage.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2017.05a
• /
• pp.158-158
• /
• 2017

상수관망을 통한 용수 공급에서는 송수펌프, 배수지 등의 수리 시설물이 중요한 역할을 수행한다. 우리나라의 송 배수 방식은 송수펌프를 통해 고지대의 배수지에 물을 확보하고, 이를 자연유하 방식으로 공급하는 것이 일반적이며, 따라서 송 배수시스템의 운영이란 송수펌프의 가동과 그에 따른 배수지의 수위 현황을 관리하는 것을 의미한다. 이 때, 펌프의 가동을 위한 전력소모에 많은 비용이 발생되므로 효율적인 펌프 운영을 위한 최적화 연구의 필요성이 제기되었다. 기존 연구를 통해 송 배수시스템의 운영을 모의하고, 펌프 가동비용을 최소화 하는 실시간 최적 펌프운영 모형이 개발되었으나, 미리 결정된 펌프와 배수지를 바탕으로 송 배수시스템을 모의하기 때문에 계획 및 설계 단계에서 이를 활용할 수 없는 한계점이 존재하였다. 본 연구에서는 최적화 알고리즘 중 하나인 유전자 알고리즘(Genetic Algorithm, GA)을 사용하여, 실시간 펌프운영뿐만 아니라 송수펌프와 배수지의 효율적인 용량을 제시할 수 있는 최적화 모형을 개발하였다. 특히, 개발 모형은 펌프와 배수지의 설계/운영 시, 국내 설계기준, 시설물 비용, 시간별 전력단가 등을 제약조건으로 고려하여 현실적인 결과를 도출할 수 있도록 개발되었다. 본 연구는 실제 운영 중인 S시의 광역상수도 시스템을 바탕으로 개발 모형을 적용하였으며, 또한 송 배수시스템의 계획 및 관리에 활용할 수 있을 것으로 기대된다.

• Journal of the Korea Society of Computer and Information
• /
• v.7 no.1
• /
• pp.74-79
• /
• 2002

In field of environments the monitoring devices for sewage disposal facilities developed to overcome a problem of the water contamination according to industrializaion and urbanization. This paper presents the operating software for monitoring device network which operator in remote station is able to check and see the operating states of the sewage disposal facilities installed in local stations. The software is executed by the hardware base developed by this study and composed of the Program modules for database, data transmission and operating state analysis. As the result of the proposed software system, it is confirmed that we are able to make improvements of the effectiveness of the operating management for environment equipments.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.33B no.11
• /
• pp.31-43
• /
• 1996

In this paper, we propsoe an encryption algorithm of image information using a mass transfer function (MTF). The algorithm is based on a diffusion phenomenon of black ink when black ink dropped in the stationary water. We mathematically analyze the phenomenon, in consideration of characteristics of image information, and apply the results of analysis to the security of image transfer phenomenon. The cryptosystem proposed in this paper enables the security services of information in narrow-band channel communication network to be provided. And in transmission of important information, it can secure against intentional disturbance and violation. Also, it can guarantee the safe flow of information.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.10a
• /
• pp.669-672
• /
• 2015

Recent Internet of Things (IoT, Internet of Things) that can be applied to various fields as the development of technology has been developed a lot of service and has been developed with the service also for crop management. To manage the essential elements of soil moisture in the crop growth but existing a direct person measuring the fluid point to carry the measuring instrument, if you take advantage of the WPAN (Wireless Personal Area Network) in this paper to manage sensor data, a fixed 3 points (30, 60, 90 cm) and can be managed can be scientifically analyzed the state of growth of the crop. Open field environment is utilized as it is less disturbance of the interference and the frequency of the radio frequency signal of the structure provides a relatively comfortable environment. Therefore, WPAN building and data transmission scheme of the minimum cost is to be developed. In addition, the operation to enter low power mode, the algorithm is necessary because a lot of restrictions on the power supply applied to the sensor nodes and the gateway is constructed in the open field. In the experiment, verifying the effectiveness by using a network configuration of each of the sensor nodes and the gateway, and provides a method for time synchronization of the operation and a low power mode. The study protocol for the RF communication with the LoRa and to enhance communication efficiency is needed in the future.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.03a
• /
• pp.1588-1595
• /
• 2005

In this study, the installation location of accelerometer and accelerograph for dam are investigated in the field to establish of emergency action against dam failure when earthquake occur and to guarantee the results of seismic stability of dams which are analysed with dynamic analysis method during 1999 to 2003 by KOWACO. By a comparative study concerning of domestic and foreign guidelines of seismic strong motion instrumentation for dams, "Guidelines of Seismic Strong-Motion Instrumentation Installation, Operation and Maintenance for Dams" is established to set up the standard of seismic strong-motion instrumentation for dam, are supervised by KOWACO There is some problems in taking a measure of stability of dams when earthquake event occur because the existing seismic strong motion instruments are operated independently. This make difficult to confirm the occurrence of seismic event. For that reason, in this study the plan of unified operation and maintenance system for strong-motion instrument for dams is designed. It will make possible real-time seismic monitoring, data transmission and receiving, giving warning for earthquake, and exchanging data with national seismic network.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.17 no.1
• /
• pp.239-260
• /
• 2023

The underwater acoustic wireless communication networks are generally formed by the different autonomous underwater acoustic vehicles, and transceivers interconnected to the bottom of the ocean with battery deployed modems. Orthogonal frequency division multiplexing (OFDM) has become the most popular modulation technique in underwater acoustic communication due to its high data transmission and robustness over other symmetrical modulation techniques. To maintain the operability of underwater acoustic communication networks, the power consumption of battery-operated transceivers becomes a vital necessity to be minimized. The OFDM technology has a major lack of peak to average power ratio (PAPR) which results in the consumption of more power, creating non-linear distortion and increasing the bit error rate (BER). To overcome this situation, we have contributed our symmetry research into three dimensions. Firstly, we propose a machine learning-based underwater acoustic communication system through long short-term memory neural network (LSTM-NN). Secondly, the proposed LSTM-NN reduces the PAPR and makes the system reliable and efficient, which turns into a better performance of BER. Finally, the simulation and water tank experimental data results are executed which proves that the LSTM-NN is the best solution for mitigating the PAPR with non-linear distortion and complexity in the overall communication system.