• Journal of Korea Multimedia Society
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• v.14 no.1
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• pp.54-75
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• 2011

PoC(Push-to-talk Over Cellular) is an integrated technology of group voice calls, video calls and internet based multimedia services. If a PoC user can not participate in the PoC session for various reasons such as an emergency situation, lack of battery capacity, then the user can use the PoC Box which has a similar functionality to the MM Box in the MMS(Multimedia Messaging Service). The RTSP(Real-Time Streaming Protocol) method is recommended to be used when there is a transmission session between the PoC box and a terminal. Since the existing VOD service uses a wired network, the packet size of RTSP-based VOD service is huge, however, the PoC service has wireless communication environments which have general characteristics to be used in RTSP method. Packet loss in a wired communication environments is relatively less than that in wireless communication environment, therefore, a buffering latency occurs in PoC service due to a play-out delay which means an asynchronous play of audio & video contents. Those problems make a user to be difficult to find the information they want when the media contents are played-out. In this paper, the following techniques and methods were proposed and their performance and superiority were verified through testing: cross-over dual reception buffering technique, advance partition multi-reception buffering technique, and on-demand multi-reception buffering technique, which are designed for effective picking up of information in media content being transmitted in short amount of time using RTSP when a user searches for media, as well as for reduction in playback delay; and same-priority packetization transmission method and priority-based packetization transmission method, which are media data packetization methods for transmission. From the simulation of functional evaluation, we could find that the proposed multiple receiving buffering and packetizing methods are superior, with respect to the media retrieval inclination, to the existing single receiving buffering method by 6-9 points from the viewpoint of effectiveness and excellence. Among them, especially, on-demand multiple receiving buffering technology with same-priority packetization transmission method is able to manage the media search inclination promptly to the requests of users by showing superiority of 3-24 points above compared to other combination methods. In addition, users could find the information they want much quickly since large amount of informations are received in a focused media retrieval period within a short time.

• Journal of IKEEE
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• v.26 no.3
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• pp.510-514
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• 2022

In this paper, we propose the development of high-sensitivity low-end radiation measuring sensor module. The proposed measurement sensor module is a scintillator + photomultiplier(SiPM) sensor optimization structure design, amplification and filter and control circuit design for sensor driver, control circuit design including short-distance communication, sensor mechanism design and manufacturing, and GUI development applied to prototypes consists of, etc. The scintillator + photomultiplier(SiPM) sensor optimization structure design is designed by checking the characteristics of the scintillator and the photomultiplier (SiPM) for the sensor structure design. Amplification, filter and control circuit design for sensor driver is designed to process fine scintillation signal generated by radiation with a scintillator using SiPM. Control circuit design including short-distance communication is designed to enable data transmission through MCU design to support short-range wireless communication function and wired communication support. The sensor mechanism design and manufacture is designed so that the glare generated by wrapping a reflective paper (mirroring) on the outside of the plastic scintillator is reflected to increase the efficiency in order to transmit the fine scintillation signal generated from the plastic scintillator to the photomultiplier(SiPM). The GUI development applied to the prototype expresses the date and time at the top according to each screen and allows the measurement unit and time, seconds, alarm level, communication status, battery capacity, etc. to be expressed. In order to evaluate the performance of the proposed system, the results of experiments conducted by an authorized testing institute showed that the radiation dose measurement range was 30 𝜇Sv/h ~ 10 mSv/h, so the results are the same as the highest level among products sold commercially at domestic and foreign. In addition, it was confirmed that the measurement uncertainty of ±7.4% was measured, and normal operation was performed under the international standard ±15%.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.6
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• pp.25-31
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• 2016

With the development of IOT technology and the expansion of ICT services recently, a variety of home network services have been advanced based on wired and wireless high speed telecommunication. Domestic and global companies have been studying on the innovative technology for the users using IOT based technology and the environment for the smart home services has been gradually developed. The users live their lives with more convenience due to the expansions and developments of smart phones. However, the threatening on the security of the smart home network had occurred by various attacks with the connection to the smart environment telecommunication, lack of applications on low powered and light weight telecommunication, and the problems of security guideline. In addition, the solutions are required for the new and variant attacking cases such as data forgery and alteration of the device for disguising approach with ill will. In this article, the safe communication protocol was designed using certification management technique based on AKI which supplemented the weakness of PKI, the existing certification system in the smart environment. Utilizing the signature technique based on ECDSA, the efficiency on the communication performance was improved, and the security and the safety were analyzed on the security threat under the smart home environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.278-283
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• 2000

As information communication technology developed we could check our blood pressure, pulsation electrocardiogram, SpO2 and blood test easily at home. To check our health at ordinary times is able though interlocking the house medical instrument with the wireless public data network This service will help the inconvenience to visit the hospital everytime and will save the individual's time and cost. In each house an organism data which is detected from the human body will be transmitted to the distance hospital and will be essentially applied through wireless public data network The medical information transmit system is utilized by wireless close range network It would transmit the obtained organism signal wirelessly from the personal device to the main center system in the hospital. Remote telemetry system is embodied by utilizing wireless media access protocol. The protocol is embodied by grafting CSMA/CA(Carrier Sense Multiple Access with Collision Avoidance) protocol falling mode which is standards from IEEE 802.11. Among the house care telemetry system which could measure blood pressure, pulsation, electrocardiogram, SpO2 the study embodies the ECC(electrocardiograph) measure part. It within the ECC function into the movable device and add 900㎒ band wireless public data interface. Then the aged, the patients even anyone in the house could obtain ECG and keep, record the data. It would be essential to control those who had a health-examination heart diseases or more complicated heart diseases and to observe the latent heart disease patient continuously. To embody the medical information transmit system which is based on wireless network. It would transmit the ECG data among the organism signal data which would be utilized by wireless network modem and NCL(Native Control Language) protocol to contact through wireless network Through the SCR(Standard Context Routing) protocol in the network it will be connected to the wired host computer. The computer will check the recorded individual information and the obtained ECC data then send the correspond examination to the movable device. The study suggests the medical transmit system model utilized by the wireless public data network.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.1
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• pp.95-99
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• 2003

In addition to wired communication technology, wireless communication technology has had communication revolution nowadays. Bluethooth technology carries out data/voice communication within pico-net. Nowadays the various services are supported by access network connected to public network. This paper presents implementation of bluetooth protocol analyser which simulates bluetooth protocol. MS window98 and visual C are used for development environment and application program is operated over the firmware loaded on the bluetooth device connected to the PC through UART which of the maximum transmission rate is 115kbps because transmission rate less than 20kbps affects rarely the performance. The performance analysis on the propose system is carried out as simulating the signalling information for the voice test and the traffics between two bluetooth systems for file transfer. The throughput analysis for file transfer service and call processing capacity for voice service are considered as performance analysis parameters. File access time is very important parameter and throughput is 13 kbps in case breakpoint time to file access is 0.04sec. Also call processing time is about 16.6ms in case of communication with the headset. The performance analysis of simulation results satisfies with bluetooth device development.

• Convergence Security Journal
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• v.7 no.3
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• pp.87-93
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• 2007

We propose a mobile point-of-sale system, which consists of only mobile information terminals and personal computers. The proposed system provides most of functionalities related with resource planning, adminstration and management, provided by medium-scale or large-scale POS systems, with additional functionalities, such as automatic information gathering and management through mobile interconnection, while eliminating the necessity of additional special-purpose devices, such as bar-code systems. The proposed system transmits order information through wireless and wired communication lines, thus allowing real-time sharing of order information among diverse information devices, such as mobile order receiving terminals, main server within stores, monitors and printers located in production lines. Also, the system is able to transfer such detail information produced within stores in real-time to the enterprise-level accounting, sales, logistics, personnel management system, which facilitate enterprise-wide management and administrative decision-making. No additional programs are required for mobile terminals. Order information received by such terminals are entered into databases through web server of main server and that information is again transferred to main server and production line printers. The proposed system can handle all the point-of-sale information and can provide almost of the POS functionalities by simply utilizing wireless internet, personal computers, and mobile terminals without installing specific-purpose peripheral devices. The proposed system can be widely applied to the small-scale stores and will contribute in reducing construction and maintenance cost required for point-of-sale management.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.4
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• pp.155-162
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• 2013

Routing protocol in ad hoc mobile networking has been an active research area in recent years. However, the environments of ad hoc network tend to have vulnerable points from attacks, because ad hoc mobile network is a kind of wireless network without centralized authentication or fixed network infrastructure such as base stations. Also, existing routing protocols that are effective in a wired network become inapplicable in ad hoc mobile networks. To address these issues, several secure routing protocols have been proposed: SAODV and SRPTES. Even though our protocols are intensified security of networks than existing protocols, they can not deal fluidly with frequent changing of wireless environment. Moreover, demerits in energy efficiency are detected because they concentrated only safety routing. In this paper, we propose an energy efficient secure routing protocol for various ad hoc mobile environment. First of all, we provide that the nodes distribute security information to reliable nodes for secure routing. The nodes constitute tree-structured with around nodes for token escrow, this action will protect invasion of malicious node through hiding security information. Next, we propose multi-path routing based security level for protection from dropping attack of malicious node, then networks will prevent data from unexpected packet loss. As a result, this algorithm enhances packet delivery ratio in network environment which has some malicious nodes, and a life time of entire network is extended through consuming energy evenly.

• Korean journal of aerospace and environmental medicine
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• v.30 no.3
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• pp.83-85
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• 2020

In commemoration of Vol. 30, Issue 3, our journal prepared five review articles and one original paper. The global outbreak of COVID-19 in 2020 has impacted our society, and especially the aviation and travel industries have been severely damaged. Kwon presented the aviation medical examination regulations related to COVID-19 announced by the Ministry of Land, Infrastructure, and Transport of the Republic of Korea. Lim summarized various efforts of airlines to overcome the crisis in the aviation industry. He also discussed the management of these aircraft as the number of airplanes landing for long periods increased. Finally, he suggested various quarantine guidelines at airports and onboard aircraft. COVID-19 has had a profound impact on mental health as well as physical effects. Kim investigated the impact of COVID-19 on mental health and suggested ways to manage the stress caused by it. The Internet of Things (IoT) refers to a technology in which devices communicate with each other through wired or wireless communication. Hyun explained the current state of the technology of the IoT and how it could be used, especially in the aviation field. In the area of airline service, various situations arise between passengers and crew. Therefore, role-playing is useful in performing education to prepare and respond to passengers' different needs appropriately. Ra introduced the conceptual background and general concepts of role-playing and presented the actual role-play's preparation process, implementation, evaluation, and feedback process. For a fighter to fly for a long time and perform a rapid air attack, air refueling is essential, which serves refueling from the air rather than from the aircraft base. Koo developed a questionnaire based on the HFACS (Human Factors Analysis and Classification System) model and used it to conduct a fighter pilot survey and analyze the results.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.6
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• pp.623-631
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• 2020

An electromagnetic pulse (EMP) attack on a nuclear weapon or the airlift of an electronic bomb affects weapons systems, information devices, wired and wireless communication equipment, and power supply equipment. It can lead to confusion on the battlefield. The current standards for EMP protection when applied to the military are centered on fixed and mobile facilities and equipment. It is, however, important to study EMP protection for a single tactical unit centered on the weapon system. In this study, EMP protection standards were established for command and control, maneuvering and firepower systems vulnerable to EMPs, focusing on battle tanks with mobility, firepower, and shock force. Also, specific development plans for EMP protection capabilities are proposed, including the shielding and blocking of EMPs. Through the study, the Korean government intends to ensure a unit's command and control under an EMP attack as well as preserve the viability of a unit's personnel and guarantee the conditions for the execution of a mission.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3B
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• pp.314-324
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• 2004

Recently, high-speed internet subscribers have grown continuously, and reached up to 10 millions. But existing network management that is responsible only for user access is confronted with many difficulties, since user access network(xDSL, Cable, B-WILL, and so on) has diversified and value added wired/wireless contents service has developed. In this paper propose the Agent based Inter Networking platform as object-oriented hierarchical system that can provide various service such as access QoS(Quality of Service), customized application service and security service according to user on demand. This system has divided into two parts(user agent and agent management system ＆ local and central management systems). Management system periodically receive status information such as bandwidth, download speed, delay, current service, and so on, and process them, then build a policy based on processed information. According to personal user profile that is generated by this policy, the customized service can be provided for users. And This system adopt the object-oriented modeling in case that system migration and integration, and implement a system that is robust and stable for security through hierarchical server system.