• KIPS Transactions on Computer and Communication Systems
• /
• v.9 no.2
• /
• pp.31-36
• /
• 2020

The creation of the Defense Integrated Data Center(DIDC) has resulted in a reduction in manpower, operating costs, efficient and effective management of resources. However, it is difficult to effectively collect and manage the data of a large number of battlefields coming from equipments such as drones, robots, and IoT added to the fourth industrial revolution and the future battlefield. Therefore, we will propose the design of DIDC network system using NFV and SDN, which are emerging as the core technologies of 5G, a mobile communication technology. After analyzing the data sheet of each equipment, it is considered that by integrating the redundant functions, energy efficiency, resource utilization and effective network management will be possible.

• Korean Institute of Interior Design Journal
• /
• v.19 no.5
• /
• pp.173-181
• /
• 2010

Opened on November 2008, as the public exhibition center of a telecommunication company, T.um is dedicated for delivering the future ubiquitous technologies and business vision of the company leading domestic mobile communication business to the global expected clients and business partners. Since the public opening, not only over 18,000 audiences in 112 nations have been visiting T.um, but also the public media have been releasing news regarding the ubiquitous museum constantly. By the reasons, T.um is regarded as a successful case for public exhibition centers. The most distinguished quality of the museum is established by the Location Based Service technology in the initial construction stage. A visitor in anyplace of T.um can be detected by digital devices equipped GPS systems. The LBS system in T.um allows visitors to get the information of relevant technologies as well as the process of how to operating each content at his own spots by smart phone of which wireless network systems make it possible. This study is focusing on analyzing and defining the T.um special qualities in terms of technologies to provide the basic data for following exhibition space projects based on LBS. The special method of experiencing contents can be designed by utilizing the network system applied to T.um in the planning stage.

• Proceedings of the KIEE Conference
• /
• 2007.04a
• /
• pp.289-291
• /
• 2007

The Digital Multimedia Broadcasting(DMB) system is developed to offer high quality audio-visual multimedia contents to the uses by the various portable terminals in the mobile environment. Integrated complex reception platform is required to receive multimedia broadcasting services transmitted from various transmission media. In this paper, we present the design and implementation technic for providing the both of terrestrial and satellite DMB services simultaneously using the same hardware platform. The implemented complex receiving terminal to accommodate these DMB services simultaneously need composed of it RF module. it baseband module, it complex control module and the complex de-multiplexer module. The complex control module is designed using uClinux operating system. The complex de-multiplexer, which perform the functions of the address decoder and each DMB stream de-multiplexer, is implemented. with FPGA device. The implemented platform is tested in a real environment and its performance is satisfied with required performance criteria.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.24 no.12A
• /
• pp.1868-1875
• /
• 1999

The design of LAI(Local Area Identifier), the first paging area for searching the mobile terminal has a close relation with the performance of paging channel in CDMA cellular network. This paper discussed the performance of the forward channel of IS-95 CDMA standard, known as the paging through the related messages such as call control message, channel assignment message, etc. Modeling and simulation work were conducted to quantify the performance of paging channel in terms of traffic handling capacity and blocking levels. The results shown are based on a specific system call model based on the operating system of cell cite. This serves as illustrative guidelines for the proper engineering of common control channel, which has a major impact on the overall performance of cellular network.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2002.05a
• /
• pp.554-558
• /
• 2002

In this paper, we analysed the technical characteristics of a universal shipborne automatic identification system using self-organizing time division multiple access in the VHF marine mobile band. IMO's Marine Safety Committee approved revision of chapter V of the Safety of Life at Sea(SOLAS) Convention in 73rd meeting. According to this revision, AIS will become a nandatary carriage requirement by 01 July 2002. AIS is a broadcast system, operating in the VHF marine band. It is capable of sending infomation such as would be beneficial to the safety of navigation and the identification and monitoring of maritime traffic. It is absolutely necessary to analyse the related international and domestic specifications for the AIS implementation and installation.

• Journal of Korea Multimedia Society
• /
• v.22 no.4
• /
• pp.463-471
• /
• 2019

The growth of mobile technology particularly smartphone applications such as ticketing, access control, and making payments are on the increase. Elliptic Curve Cryptography (ECC)-based systems have also become widely available in the market offering various convenient services by bringing smartphones in proximity to ECC-enabled objects. When a system user attempts to establish a connection, the AIK sends hashes to a server that then verifies the values. ECC can be used with various operating systems in conjunction with other technologies such as biometric verification systems, smart cards, anti-virus programs, and firewalls. The use of Elliptic-curve cryptography ensures efficient verification and signing of security status verification reports which allows the system to take advantage of Trusted Computing Technologies. This paper proposes a device payment method based on ECC and Shuffling based on distributed key exchange. Our study focuses on the secure and efficient implementation of ECC in payment device. This novel approach is well secure against intruders and will prevent the unauthorized extraction of information from communication. It converts plaintext into ASCII value that leads to the point of curve, then after, it performs shuffling to encrypt and decrypt the data to generate secret shared key used by both sender and receiver.

• Transactions of the Korean hydrogen and new energy society
• /
• v.24 no.3
• /
• pp.264-274
• /
• 2013

Piping systems play an important role in gas and oil transferring system. In the piping system, there are many elements, such as valves and flow meters. In order to check their normal operating conditions, each signal from each element is displayed on the monitor in the pipe control room. By the way, there are several accidental cases in the piping system even if all signals from the local elements are judged to be normal on the monitor in the control room. Further, opposite cases often happen even the monitor shows abnormal while the local elements work normal. To overcome this abnormal functions, it is not so easy to construct the environment in which sensors detecting the working states of all elements installed in the piping system. In this paper, a new non-contact measurement technique which can calculate the elements' delicate displacements by using a PIV(particle image velocimetry) and diagnose their working states by using a neural network is proposed. The measurement system consists of a host computer, a micro system, a telescope and a high-resolution camera. As a preliminary test, the constructed measurement system was applied to measure delicate vibrations of mobile phones. For practical application, a pneumatic system was measured by the constructed system.

• Journal of Advanced Navigation Technology
• /
• v.18 no.5
• /
• pp.513-517
• /
• 2014

In this study, we implemented and designed an RF monitoring system to manage a dust collector wirelessly, which is manually operated. The dust collector prevents the emission of air pollutants and improves air condition. It is possible to implement a high-value monitoring system of a dust collector, the system will wirelessly monitor many important data such as the operating time, the amount of electricity consumption, and the differential pressure value of a large number of the dust collectors in an industrial site, the system also displays and saves these data on a manager's PC, and when an error occurs, the system sends the error message to a manager's mobile phone. Therefore, through the RF monitoring system implemented in this paper, it is possible to reduce unnecessary loss for recording information of each dust collector to stack emission management system (SEMS).

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.12
• /
• pp.5457-5463
• /
• 2011

The objective of this study is to investigate cooling performance characteristics of mobile air conditioning system using R744 as an alternative of R-134a. In order to analyze the cooling performance characteristics of the air conditioning system using R744 for a passenger vehicle, the developed air conditioning system using R744 was applied in a real passenger vehicle and tested under various operating conditions with the variation of gas-cooler inlet air conditions, evaporator inlet air temperatures and compressor speeds. As a result, cooling capacity and coefficient of performance (COP) of the tested air conditioning system decreased with the rise of the inlet air temperature of the gas cooler but increased with the rise of the inlet air temperature of the evaporator. In addition, cooling capacity and coefficient of performance (COP) increased by 42.2 % with the rise of the compressor speed from 900 rev/min to 1800 rev/min, but it decreased by 55.4%.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.28 no.8
• /
• pp.325-330
• /
• 2016

This study was conducted to develop a heating system for a fuel cell-driven electric vehicle. The system consists of a compressor, an expansion device and three heat exchangers. A conventional air source heat exchanger is used as primary heat exchanger of the system, and an additional water source heat exchanger is used as a pre-heater to supply heat to the upstream air of the primary heat exchanger. On the other hand, the third heat exchanger consists of a water-to-refrigerant heat exchanger. The heat source of the pre-heater and the water-refrigerant heat exchanger is the waste heat from the fuel cell's stack. In the experiment, the indoor and the outdoor air temperature were fixed, and the compressor speed, EEV opening and waste heat temperature were varied. The results indicate that the $COP_h$ of the proposed system is 3.01 when the system is operating at a 1,200 rpm compressor speed, 50% EEV opening, and $50^{\circ}C$ waste heat source temperature in air pre-heater operation. However, when the system uses a water-refrigerant heat exchanger, the $COP_h$ increases to up to 9.42 at the same compressor speed and waste heat source temperature with 75% EEV openings.