• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.12
• /
• pp.778-784
• /
• 2017

In this paper, we propose wired and wireless distributed control systems designed to improve the freight logistics efficiency and verify wired distributed control systems. The verification condition required that 50 cargo vehicles be connected and operated to travel 21 km from Busan Sinhang station to Jinlye Station at an average speed of about 100km/h. The verification results show that the traction output and braking output of the control and controlled cars are dispersed by the wired distributed control system. The application is expected to more than double the efficiency of the logistics compared to the existing freight transportation system. However, in the case of the wired distributed control system, cable installation and maintenance are difficult, and it is impossible to change the combination of freight vehicles. Through the verification of the wired distributed control system, the applicability of distributed control systems to freight vehicles in Korea was confirmed and the system was further developed to produce a wireless distributed control system. In order to apply the wireless distributed control system, a propagation environment analysis for the ISM band was performed in the testbed and, as a result, it was confirmed that Wifi technology using the ISM band could be utilized. In order to use the WDP (Wireless Distributed Power) devices newly installed in the target vehicles, the transmission / reception control signals associated with the propulsion / braking / total control devices are defined. In the case of wireless distributed control systems, the convenience of their application and operation is guaranteed, but reliability and emergency safety measures should because of the dependence of the control of the vehicle on radio signals.

• Journal of the Korea Society for Simulation
• /
• v.20 no.3
• /
• pp.41-48
• /
• 2011

Wireless communication technology developed, portable wireless devices based on wireless network including the smartphone rapidly developed, and products with functions similar to highly efficient computer are being launched. Therefore, active studies to enable performance of works, which were previously held in computers, on portable wireless terminal are being held. Until now, simulation was undertaken using computers which satisfy high performance computing resource. Such contains a problem that it cannot break away the limit of space. Portable wireless terminal has the merit that it can break away from the limit of space by using wireless network in comparison to wired environment. In this paper, it suggests a simulator based on wireless devices for distributed simulation. For such purpose, the performance time of simulation will be compared in regards to the case of performing nodes control simulation in a single highly efficient computer and the case of performing distributed simulation in many wired and wireless network environments. Through the comparison, the possibility for utility of portable wireless terminal as the object of distributed simulation will be verified, and it will be presented that simulation can be performed in a shorter time by performing distributed simulation under various wired and wireless network environments away from the limit of space.

• Journal of Advanced Navigation Technology
• /
• v.12 no.5
• /
• pp.444-450
• /
• 2008

With the advancement of the mobile device and arrival of the integrated wired/wireless environments, the damand for services accessible by mobile devices is rapidly increasing. However, unlike existing wired networks, communication in wireless networks has many weaknesses. Therefore, research and development into an appropriate security technology has reached a critical stage, as combined wired/wireless environments emerge. Therefor, in this paper, we propose that device authentication technology in AAA (Authentication, Authorization, Accounting) mechanism of Mobile environment for secure service offer.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
• /
• v.11 no.1
• /
• pp.16-22
• /
• 2012

Wireless data communication is easy to be affected by channel noise and degrade reliability and stability by the multipath fading and ISI compared with wired data communication. In this paper, we designed and implemented indoor wireless modem adopted DQPSK modulation scheme for improvement of bandwidth efficiency, and convolutional encoding, Viterbi decoding and hybrid ARQ algorithm combinig FEC with CRC for efficient error control in indoor wireless channel. Testing the implemented wireless modem, we verified the proposed scheme is proper to efficient and reliable indoor wireless data communication.

• Journal of the Korea Society of Computer and Information
• /
• v.9 no.4 s.32
• /
• pp.149-155
• /
• 2004

Current wireless internetservice of domestic five mobile communication companies are being limited to the service using markup-language. platform and Contents. Therefore, research on integration Contents of different Wireless internet platform and its development are necessary. For the easiness of maintenance and compensation. this paper attempts to design a Wireless internet Contents converter for integrate wired and wireless platform which automatically converts to WML and C-HTML through analysis of HTML document.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.10
• /
• pp.235-242
• /
• 2014

LED lighting control technique is one of the ongoing research areas for efficient management of LED lighting. In this paper, we design and implementation of LED street lighting remote control system which have a wired and wireless communication function for LED street lighting remote control. The implemented system can automatically dimming and individual(or consolidated) LED street lighting via RS-485/422 or Wi-Fi. In experimental results, the implemented remote control system was satisfactory for all of the desired functions.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.13 no.4
• /
• pp.85-98
• /
• 2003

Computational power of IC chip is improved day after day producing IC chips holding co-processor continuously. Also a lot of wireless terminals which IC chip embedded in are produced in order to provide simple and various services in the wireless terminal market. However it is difficult to apply the key distribution protocol under wired communication environment to wireless communication environment. Because the computational power of co-processor embedded in IC chip under wireless communication environment is less than that under wired communication environment. In this paper, we propose the hey distribution protocol appropriate for wireless communication environment which diminishes the computational burden of server and client by using co-processor that performs cryptographic operations and makes up for the restrictive computational power of terminal. And our proposal is satisfied with the security requirements that are not provided in existing key distribution protocol.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.9 no.4
• /
• pp.313-322
• /
• 2016

This paper presents a method to improve the performance of Scalable Multicast Protocol deployed in wired and wireless network by adding retransmission function on base stations. When using Scalable Multicast Protocol over wireless and wired networks, packet drops on the wireless link produce the initiation of retransmission request packets and the implosion of retransmission packets, which deteriorate the multicast session performance. The efficient reliable multicast mechanism in wireless networks utilizing the retransmission function on the base station is addressed in this paper. We explain the design of a retransmission function which improves the performance of Scalable Multicast Protocol sessions in wireless and wirednetwork. The main idea is to cache Scalable Multicast Protocol packets at the base station and perform local retransmissions across the wireless link. ARENA has been used to simulate and to get performance for reducing signaling overhead and processing delay through the comparison of the proposed function to the Scalable Multicast Protocol.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.05a
• /
• pp.553-556
• /
• 2013

Currently green growth and energy saving are major issues and solution using low-power LED lighting devices are gaining popularity. There are a few standards to control these LED lighting equipment and DMX512 protocol is a typical communication control standard used. DMX512 lighting control protocol is one of standard protocols widely used in various fields which include mainly stage lighting and landscape lighting. But in DMX512 protocol, line is to be connected to a wired connection. Advantage of wired connection is stable data transfer operation but it adds complexity and certain constraints as well in wired connection. To solve this problem, wired connection can be replaced efficiently with a wireless connection but for wireless, problem of data loss and two way communications arises. In this paper, these problems of wireless communication for DMX512 have been addressed and solutions for two way communications and data loss problem have been proposed.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.22 no.11
• /
• pp.1106-1112
• /
• 2012

This paper deal with a technique for monitoring machining conditions by measuring the vibration of cutting forces at milling machining. The vibrations of cutting forces in milling process were measured and analyzed to be related with processing parameters. The magnitude of cutting force is linearly proportional to the feed rate and cutting depth, and frequency of cutting force is linearly proportional to the rotating speed. Wired and wireless communication methods were applied in transmitting the measured vibration signals and the two methods were compared. The magnitude of the vibration signals transmitted by the wireless communication method was similar to that transmitted by the wired communication method.