• Journal of KIISE
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• v.45 no.3
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• pp.303-310
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• 2018

LoRaWAN(Long Range Wide Area Network) is a standard for low-power, long-range, low-speed communication as announced in the LoRa Alliance. LoRaWAN addresses the physical layer and medium access control layer and the technology used in the physical layer is referred to as LoRa. LoRa can be used for remote monitoring and remote control in maritime conditions. However, unlike land, marine environment is not only difficult to construct an infrastructure for service provision, but also difficult to analyze LoRa performance in maritime. In this study, we construct an infrastructure using cloud platform and analyze LoRa link performance in maritime conditions.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.2
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• pp.55-61
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• 2001

In this paper, a synchronous reverse link DS-CDMA system with cdma2000 standard is simulated to analyze performance of system and to find the optimum power ratio between pilot channel and traffic channel. In the cdma2000 the pilot channel is used to estimate fading channel, in contract to IS-95 and it compensates phase variation of received signal due to channel environment. When the length of channel estimation is 31pcg symbols, we can find the optimum power ratio of pilot channel to traffic channel. And also we find Eb/No satisfying target FER when the power control is applied and analyze performance of system with multiuser transmission.

• The Journal of Engineering Research
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• v.7 no.1
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• pp.53-60
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• 2005

Community Wireless Networks define the next generation wireless services. Multimedia usages for financial services over community Wireless LAN (WLAN) based mesh networks require link stability. Several new services are being proposed for multimedia over WLANs. Portable Internet Services are implemented by several wireless carriers to proliferate their customer base. However, these services are still expensive and require a central telecom/wireless carrier whose monopoly and preference defines the availability of new services. Our research project identifies the usage of these critical services in public places over the financial services backbone architecture to provide efficient easy-to-use and economical services to their customers and merchants without being dependent on the central wireless carrier. The user connects to the network using his regular WLAN NIC using the Mesh Router/Bridge interconnectivity and obtains the needed multimedia and financial services from the ATM-AP Gateway, In our proposed scenario, the ATN AP-MR use AODV protocol and MR-MC is based on 802.11g/a/b IEEE standard. We use multi path routing protocols for reducing the congestion over a particular route. We demonstrate the results of our simulations and test-bed outcome to evaluate link failure rate and oversubscription factors to eliminate network congestion and non-availability of the critical financial services.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9B
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• pp.1518-1526
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• 2000

This paper proposes an optical transmission link design method based on an optimum compensation scheme using dispersion compensating fiber (DCF), so that high-speed long-distance optical transmission would be possible over the conventional standard single mode fiber (SMF) link. The proposed design method provides the maximized transmission distances according to the signal speeds, where the amplifier spacing and repeater spacing are optimized wit respect to self-phase modulation(SPM) due to fiber nonlinearity and amplified spontaneous emission (ASE) noises caused by optical amplifies. It is also shown that there exists an optimum input signal power range balancing the effects of ASE noise and SPM for the given amplifier spacing and repeater spacing.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.7B
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• pp.499-504
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• 2012

Recently, base stations composed of digital unit (DU) and radio unit (RU) have been widely used in 4G mobile networks. To connect DU and RU, CPRI (common public radio interface) is usually used as the interface standard. This CPRI link is considered as one of the application markets for WDM-PON. In this paper, we analyzed the required specification of WDM-PON for the CPRI link of the 4G LTE-Advanced base station composed of DU and RU. This analysis is important to set a target goal of the development of WDM-PON system for 4G mobile networks.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2008.11a
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• pp.448-451
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• 2008

This study is under doing to suggest application manual using assembling reference plane design & standard finish material basis upon material classification code as a tool of a linkage between building design and construction standarization in order to enlarge the applicability of house building material that is produced by the module plant. We can say the goal of building standardization intend not only the improvement of construction productibility but also guarantee of subsequent performance through automatization basis upon informationalization of building design. For a etabilishing of this condition, it is neccessary to link the standardization's result of material--design--construction field. According to this neccessity, we are going to suggest information factor that can make relative business manager easily approach to the standardization practical task.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.97-100
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• 1999

Mobile network applications are growing and this requires a fast and efficient transport method between the BS(Base Station) and the MSC(Mobile Switching Center). One possible solution is to use ATM and a voice CODEC standard which compresses 64kbps voice data to less than 8kbps. The low bit tate and small-sized packets made by the voice CODEC imply that significant amount of link bandwidth would be wasted, if this small-sized packet is carried by one ATM cell. The cell assembly delay increases if one ATM cell is fully filled with the small-sized packets. For the bandwidth-efficient transmission of low-rate, short, and variable length packets in delay sensitive applications, AAL-2 was standardized. This paper evaluates performance of AAL-2 by using voice CODEC standard.

• Journal of Korea Society of Digital Industry and Information Management
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• v.14 no.1
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• pp.15-25
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• 2018

ISO/IEC 15118 is a standard for communications and services for electric vehicle charging infrastructure. Although this standard deals only with data communication between an electric vehicle and a charge station, communication with the outside is essential for establishing an authentication system for vehicle certification and V2G service for electric power transmission. In this study, it was designed to verify the information of electric car charging infrastructure in electric power system through communication link between ISO/IEC 15118 electric vehicle model and IEC 61850 standard MMS protocol. This is demonstrated in the field so that the electric vehicle communication data is linked with the micro grid management system. This could be used as an element technology in other distributed power sources as well as electric cars in the future.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1148-1154
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• 2009

This study focus on the suggestion of application manual using assembling reference plane design & standard finish material basis upon material classification code. We see it will function as a tool of a linkage between building design and construction standarization in order to enlarge the applicability of house building material that is produced by the module plan. For a estabilishing of this condition, it is neccessary to link the standardization's result of material--design--construction field. According to this neccessity, we are going to suggest information factor that can make relative business manager easily approach to the standardization practical task.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.3
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• pp.290-294
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• 2018

Modern warfare exhibit a NCW (Network Centric Warfare) aspect through quick situation awareness and Command and Control. And Tactical messages operate on various tactical data links (TDLs). For monitoring TDL messages processed by data link processor(DLP), message analysers are generally developed as a component during system development. In addition, in order to forward TDL messages processed by DLP to the message anayzer, the interface messages between DLP and message analysers should be defined interface control document(ICD). We propose the methods using UDP or TCP packets provided by TDL layers that are delivered to DLP without communicating directly with DLP. Depending on TDL message standards and Interface Control Documents(ICDs), we design the message analyzer which communicates with data link processor using internal messages. Using known header field information from the TDL application standard such as JREAP-C, we can quickly filter candidate packets against collected packets and use the full data size information contained in the headers to verify the completed message. Because the methods proposed in this paper do not communicate directly with DLP, the methods proposed in this paper are enable to analyze the TDL application messages such as JREAP-C or Link-K without constraints in existing methods that should be reflected in the system configuration and ICD.