• ETRI Journal
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• v.36 no.3
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• pp.352-360
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• 2014

This paper presents a 900 MHz zero-IF RF transceiver for IEEE 802.15.4g Smart Utility Networks OFDM systems. The proposed RF transceiver comprises an RF front end, a Tx baseband analog circuit, an Rx baseband analog circuit, and a ${\Delta}{\Sigma}$ fractional-N frequency synthesizer. In the RF front end, re-use of a matching network reduces the chip size of the RF transceiver. Since a T/Rx switch is implemented only at the input of the low noise amplifier, the driver amplifier can deliver its output power to an antenna without any signal loss; thus, leading to a low dc power consumption. The proposed current-driven passive mixer in Rx and voltage-mode passive mixer in Tx can mitigate the IQ crosstalk problem, while maintaining 50% duty-cycle in local oscillator clocks. The overall Rx-baseband circuits can provide a voltage gain of 70 dB with a 1 dB gain control step. The proposed RF transceiver is implemented in a $0.18{\mu}$ CMOS technology and consumes 37 mA in Tx mode and 38 mA in Rx mode from a 1.8 V supply voltage. The fabricated chip shows a Tx average power of -2 dBm, a sensitivity level of -103 dBm at 100 Kbps with PER < 1%, an Rx input $P_{1dB}$ of -11 dBm, and an Rx input IP3 of -2.3 dBm.

• Journal of Korea Spatial Information System Society
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• v.11 no.1
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• pp.71-78
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• 2009

A demand on the spatial data management has been rapidly increased with the introduction and diffusion process of ITS, Telematics, and Wireless Sensor Network. And many different users use the digital map that offers various thematic spatial data. Spatial data for digital map can be managed by tile-based and feature-based data. The existing tile-based digital map management systems have difficult problems such as data construction, history management, and update data based on a spatial object. In order to solve these problems, we proposed the data model for feature-based digital map management system for representation of feature-based seamless map, history management, real-time update of spatial data, and analyzed the validity and utility of the proposed model.

• Journal of the Korea Computer Industry Society
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• v.2 no.4
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• pp.565-572
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• 2001

At the most recent years, laser medical instruments, laser applications and laser nuclear fusion need strong visible light and ultraviolet rays. Nonlinear optical devices, such as harmonic generators and parametric oscillators, provide a means of extending the frequency range of available laser sources. Frequency conversion is a useful technique for extending the utility of high-power lasers. It utilizes the nonlinear optical response of an optical medium in intense radiation fields to generate new frequencies. These progresses have been used to generate high-power radiation in all spectral regions, from the ultraviolet to the far infrared. Optical parametric oscillators and amplifiers generate two waves of lower frequency They are capable of generating a range of wavelengths from a single frequency source, in some cases spanning the entire visible and near infrared regions. Consequently, in order to obtain the green light, the pulsed Nd:YAG laser using multiple-mesh PFN(Pulsed Forming Network) method with Nonlinear optical device was adopted. We compared the current pulseshapes with the laser output energy, and conversion efficiency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.9B
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• pp.803-810
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• 2006

Mobile ad hoc nodes are supposed to be equipped with a number of operation modules including a specific routing operation module in heterogeneous MANET environment. It is not possible for a mobile node to carry all the necessary operation modules due to the limited resources. This paper proposes a scheme to reconfiguring mobile ad hoc nodes using smart packets in heterogeneous routing domains. The smart packet protocol has a capability to transfer a binary execution module to a mobile node, by which a node can be equipped with any necessary routing modules in any MANET environment. The proposed smart packet agent is designed to be suitable to a light weight terminal owing to its simple architecture. The utility of the proposed scheme was demonstrated through an example of DYMO scenario in the wireless network.

• Journal of the Korea Convergence Society
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• v.6 no.6
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• pp.75-80
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• 2015

To train convergence experts ICT infrastructure must be learned IoT use capabilities of things. In this paper, targeted to students that are majoring in computer science, and for the design of the curriculum and the educational model that handles education of operation in general for training IoT-related education for five months to experts of convergence training describe the contents. Course is the basic ability of the process, core competence course, is divided into real-life capability process and on-site training course, was constructed in a total of 10 stages of the process details. Curriculum, it was designed to learn sensing technology, network technology, security, and content production technology. This educational model is utilized for job creation human resource training project of 2015 Ministry of Employment and Labor, it demonstrated the utility to contribute in order to achieve a high completion and the employment rate. Applicable to future university education plans to expand the curriculum, including courses that complement the Java.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.53-60
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• 2017

This paper is to design and implement the drone that supports a wideband multimedia communication and a long-range to save people in maritime. The drone is an Unnamed Aerial Vehicle (UAV) that is controlled by a radio wave not by people boarding the machine. We use the drone to respond quickly to the boating accident. To develop a smart drone for the high speed seamless video streaming in a long-range maritime, a necessary techniques are hardware design techniques that design structure of a drone, controlling techniques that operate a drone and communication techniques that control a drone in a long distance. In this paper, the limitations and techniques to design and implement the structure of drone supporting wideband multimedia communication for long-range maritime are explained. By expanding this communication drone network, it is aimed at improving utility of a drone.

• Journal of the Korea Society of Computer and Information
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• v.19 no.1
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• pp.65-76
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• 2014

In this paper, we propose a high-level programming language for packet processing called eFlowC and it supporting programming development environment. Based on the C language which is already familiar and easy to use to program developers, eFlowC maintains the similar syntax and semantics of C. Some features that are unnecessary for the packet processing has been removed from C, eFlowC is highly focused on performing packet data, database, string byte information checking and event processing. Design high-level programming languages and apply an existing language or compiler technology, language function and compilation process that is required for packet processing will be described. In order to use the DPIC device such as X11, we designed a virtual machine eFVM that takes into account the scalability and portability. We have evaluated the utility of the proposed language by experimenting a variety of real application programs with our programming environment such as compiler, simulator and debugger for eFVM. As there is little research that devoted to define the formats, meanings and functions of the packet processing language, this research is significant and expected to be a basis for the packet processing language.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.7
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• pp.3524-3542
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• 2017

In a single-source and multi-relay amplify-forward (AF) cooperative network, the outage probability and the power allocation are two key factors to influence the performance of an entire system. In this paper, an optimized AF relay selection by an exclusive method and near optimal power allocation (NOPA) is proposed for both good outage probability and power efficiency. Given the same power at the source and the relay nodes, a threshold for selecting the relay nodes is deduced and employed to minimize the average outage probability. It mainly excludes the relay nodes with much higher thresholds over the aforementioned threshold and thus the remainders of the relay nodes participate in cooperative forwarding efficiently. So the proposed scheme can improve the utility of the resources in the cooperative multi-relay system, as well as reduce the computational complexity. In addition, based on the proposed scheme, a NOPA is also suggested to approach sub-optimal power efficiency with low complexity. Simulation results show that the proposed scheme obtains about 2.1dB and 5.8dB performance gain at outage probability of $10^{-4}$, when compared with the all-relay-forward (6 participated relays) and the single-relay-forward schemes. Furthermore, it obtains the minimum outage probability among all selective relay schemes with the same number of the relays. Meanwhile, it approaches closely to the optimal exhaustive scheme, thus reduce much complexity. Moreover, the proposed NOPA scheme achieves better outage probability than those of the equal power allocation schemes. Therefore, the proposed scheme can obtain good outage probability, low computational complexity and high power efficiency, which makes it pragmatic efficiently in the single-source and multi-relay AF based cooperative networks.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.14
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• pp.177-218
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• 2000

Global Electronic Trading means that trading partners trade each other via Global Electronic Trading Network, that is, global business to business electronic commerce. Recently, where the cargo arrives ahead of the B/L, the importer cannot take delivery of the cargo without the B/L. This situation is referred to as the B/L dilemma. But the BOLERO system will resolve this B/L dilemma. Bolero Project is developing a cross industry utility platform for the secure, electronic transfer of commercial trade information world wide. After the successful testing of an original pilot project, The Bolero Association was formed in 1995 by a group of interested cross industry companies. As a joint venture between SWIFT and TT Club, bolero.net is changing the way the world trades by providing a web-based, paperless mode of commerce that is designed to become a global standard. Bolero International Limited published the first edition of Bolero Rulebook in 1999. The Bolero Rulebook as amended from time to time, governing the relationship between Users and their rights and obligations arising from the Bolero system. The Bolero service will be governed by a multilateral contract called the Bolero Rule Book which specifies the rights and responsibilities of Bolero and its users. The Title Registry and Bolero Bill of Lading provide a fully functional equivalent to the paper bill of lading. The Bolero Bill of Lading can be created, transferred, amended, and surrendered by way of designating to order party, blank endorsement, refusal by the transferee etc. Thus, this study deals with the functions of Bolero Bill of Lading and the problems and solutions in the Bolero Bill of Lading in point of definitions and operation under the Bolero Rulebook.

• Journal of Communications and Networks
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• v.16 no.6
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• pp.627-638
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• 2014

In this paper, we study the joint price and power allocation in spectrum sharing macro-femtocell networks. The proposed game theoretic framework is based on bi-level Stackelberg game where macro base station (MBS) works as a leader and underlaid femto base stations (FBSs) work as followers. MBS has fixed data rate and imposes interference price on FBSs for maintaining its data rate and earns revenue while FBSs jointly adjust their power for maximizing their data rates and utility functions. Since the interference from FBSs to macro user equipment is kept under a given threshold and FBSs compete against each other for power allocation, there is a need to determine a power allocation strategy which converges to Stackelberg equilibrium. We consider two cases for MBS power allocation, i.e., fixed and dynamic power. MBS can adjust its power in case of dynamic power allocation according to its minimum data rate requirement and number of FBSs willing to share the spectrum. For both cases we consider uniform and non-uniform pricing where MBS charges same price to all FBSs for uniform pricing and different price to each FBS for non-uniform pricing according to its induced interference. We obtain unique closed form solution for each case if the co-interference at FBSs is assumed fixed. And an iterative algorithm which converges rapidly is also proposed to take into account the effect of co-tier interference on interference price and power allocation strategy. The results are explained with numerical simulation examples which validate the effectiveness of our proposed solutions.