• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.10
• /
• pp.67-75
• /
• 2013

In this paper, an analytical model is presented for the source/drain parasitic resistance of FinFET. The parasitic resistance is a important part of a total resistance in FinFET because of current flow through the narrow fin. The model incorporates the contribution of contact and spreading resistances considering three-dimensional current flow. The contact resistance is modeled taking into account the current flow and parallel connection of dividing parts. The spreading resistance is modeled by difference between wide and narrow and using integral. We show excellent agreement between our model and simulation which is conducted by Raphael, 3D numerical field solver. It is possible to improve the accuracy of compact model such as BSIM-CMG using the proposed model.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.47 no.11
• /
• pp.14-18
• /
• 2010

We propose a performance analysis of code division multiple access systems based on the combination of M-ary and pseudo-noise spreading. In spite of the total bandwidth expansion being equal, there is a difference in the system performance by the combination of M-ary and pseudo-noise spreading. The proposed analysis uses each bandwidth expansion, caused by M-ary and pseudo-noise spreading, rather than the total bandwidth expansion. If the signal to interference plus noise ratio becomes high, it is more effective to reduce biterror rate by bandwidth expansion of M-ary modulation rather than that of pseudo-noise spreading. Since the proposed analysis reflects the effect of the M-ary modulation, the bit error rate from the proposed analysis is closer to the results of the simulation than from the conventional analysis.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.9 no.6
• /
• pp.9-14
• /
• 2009

In this paper, we proposed spreading code slicing technique for efficient transmitter detection in AT-DMB system with single frequency network. At the transmitter, the spreading code for transmitter identification inserted using slicing technique on forehead of null symbol and then transmitted. In this point, it requires high correlation characteristic spreading code. At the receiver, peak to peak value calculated by correlation process before signal demodulation. The transmitter information by proposed technique is employed to implement the single frequency network (SFN) which is proposed for solving a frequency inefficiency problem of the MFN. The results of the paper can be applied to wireless multimedia digital broadcasting system.

• Journal of the Ergonomics Society of Korea
• /
• v.26 no.2
• /
• pp.103-112
• /
• 2007

This study was designed to validate Spreading Activation Theory (SAT) for an evaluation methodology for menu structure through Eye-Tracking approach. When a visual search is on the way, more eye fixations and time are necessary to visually process complex and vague area. From the aspect of recognition, well-designed menu structures were hypothesized to have fewer numbers of fixations and shorter duration because well-designed menu structures reflecting the users' mental model would be well matched with the product's menu structure, resulting in reducing the number of fixations and duration time. The results show that the shorter reaction times for SAT had significantly fewer numbers of fixation and shorter duration time as the hypothesis for this study stated. In conclusion, SAT was proved to be an effective evaluation methodology for menu structure with the eye tracking equipment. In addition, using SAT instead of the real performance experiment would be useful for designing user-centered systems and convenient information structures because SAT was proven to be the theoretical background for design and evaluation of menu structures.

• Journal of Korea Society of Industrial Information Systems
• /
• v.11 no.4
• /
• pp.112-120
• /
• 2006

Multicarrier code division multiple access(MC-CDMA) system that combines multicarrier modulation with CDMA offers robustness to frequency selective fading and can support higher rate data transmission with higher spectral efficiency. A new asynchronous MC-CDMA system to implement multiple data rate communications is proposed in this paper. In a W-CDMA downlink the orthogonal variable spreading factor(OVSF) code is used for variable spreading factor for various multimedia traffic. Proposed system utilizes the OVSF code that generated by generation property for spreading. The proposed MC-CDMA system use different lengths of OVSF code as a spreading code according to their data rate. The groupwise processing is accomplished by code grouping in OVSF code generation tree. For the analysis of average BER performance, numerical method and computer simulation were used. We also compare the system performance with that of a single rate MC-CDMA system used orthogonal code as a spreading code.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.3
• /
• pp.607-614
• /
• 2016

In generating station, cable spreading design is a very important task, which is very much time consuming, due to the type of cable used in generating station is very diverse. The raceway means the cable line section from source equipment to destination, and consists of cable tray and conduit. The process of existing cable spreading design was written in by hand. Thereby, there are grossly inefficient gain such as cable omission and unfixed fill value by a personal and time investment. In this paper, we proposed and implemented the automated cable route design based flexible cable fill check in generating station, and proposed the automated cable route design can be calculated the cable fill with flexible changing of raceway. Some experimental result shows that implemented cable route design is well performed and conducted as the design specifications, and it will be able to reduce the cable spreading design time.

• Information and Communications Magazine
• /
• v.16 no.4
• /
• pp.29-36
• /
• 1999

• ETRI Journal
• /
• v.30 no.1
• /
• pp.21-32
• /
• 2008

Cognitive radio (CR) has been proposed as an effective technology for flexible use of the radio spectrum. The interference between primary users and CR users, however, becomes a critical problem when they are using adjacent frequency channels with different transmission power levels. In this paper, a robust CR orthogonal frequency division multiplexing (OFDM) architecture, which can effectively suppress interference to nearby primary users and overcome adjacent channel interference (ACI) to the CR user, is proposed. This new approach is characterized by adaptive data repetition for subcarriers under heavy ACI, and adaptive time spreading for subcarriers near the borders of the CR user's spectrum. The data repetition scheme provides extra power gain against the ACI coming from primary users. Time spreading guarantees an acceptable interference level to nearby primary users. By computer simulation, we demonstrate that, under a CR environment, the proposed CR OFDM architecture outperforms conventional OFDM systems in terms of throughput and BER performance.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.4 no.4
• /
• pp.509-528
• /
• 2010

The random access systems, with retransmission diversity (RD) employment, over large random spreading code division multiple access (CDMA) channel subject to fading is investigated, under the assumption of infinite number of users and infinite spreading gain with their ratio converging to a constant. The low bound of the signal to interference and noise ratio (SINR) is shown to converge almost surely to a constant. The throughput, spectrum efficiency and energy efficiency in the dominating systems are obtained. The analytical results are confirmed by simulations. We find that in high traffic loads the throughput with fading is higher than that without. When the energy efficiency increases, the spectrum efficiency tends to two contrary values due to SNR increases or decreases. For the ordinary stable systems, the stability region is shown to shrink as the traffic increases and enlarge with RD employment.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.7
• /
• pp.1290-1295
• /
• 2016

Recently, as mobile internet usage has been increasing rapidly, malware attacks through user's web browsers has been spreading in a way of social engineering or drive-by downloading. Existing defense mechanism against drive-by download attack mainly focused on final download sites and distribution paths. However, detection and prevention of injection sites to inject malicious code into the comprised websites have not been fully investigated. In this paper, for the purpose of improving defense mechanisms against these malware downloads attacks, we focus on detecting the injection site which is the key source of malware downloads spreading. As a result, in addition to the current URL blacklist techniques, we proposed the enhanced method which adds features of detecting the injection site to prevent the malware spreading. We empirically show that the proposed method can effectively minimize malware infections by blocking the source of the infection spreading, compared to other approaches of the URL blacklisting that directly uses the drive-by browser exploits.