• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.153-154
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• 2008

In this paper, we propose a diversity-enhancing scheme in a single link fading channel using repetition QPSK symbol code. The proposed scheme can be converted to rate outage formula and obtains enhanced diversity performance while guaranteeing the required data rate. Simulation result shows that the proposed scheme improves the rate outage performance compared to the conventional BPSK diversity schemes.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.155-156
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• 2008

This paper provides a general and compact expression for the probability density function (pdf) and the moment-generating function (MGF) of the maximal ratio combiner output over Rayleigh fading channels. It is then used to derive closed form expression outage probability for repetition code problem. A variety of simulations is performed and shows that they match exactly with analytic ones.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.5
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• pp.268-272
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• 2004

A high voltage pulse generator with a rotator airhole spark gap instead of a rotary ball spark gap has been proposed and investigated. Its feasibility as a high voltage pulse generator is compared with the rotary ball spark gap type one. Parametric studies showed that proposed the rotary airhole type spark gap had a very stable breakdown voltage and reliable pulse repetition time compared with the conventional rotary ball type spark gap. This however showed that the proposed pulse generator with a rotary airhole spark gap instead of a rotary ball spark gap could be potentially used as a very stable and reliable pulse generator in the various fields of applications.

• Journal of Korea Multimedia Society
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• v.11 no.6
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• pp.828-834
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• 2008

This paper presents high-spread (HS) random interleavers based interleave-division multiple access (IDMA) scheme for the 4th generation mobile radio system. High-spread feature of a random interleaver offers high-spread characteristics to interleavers and thus produces extrinsic values with low correlation. As interleavers are key components for user separation in the IDMA, the HS interleavers with this feature are employed and analyzed in the IDMA for performance improvement. In addition, by replacing random interleavers with the HS interleavers in the IDMA, bandwidth efficiency is achieved by means of reducing the length of the repetition code. Performance evaluation shows that the proposed scheme of the IDMA with the HS interleavers provides superior BER performance and improved bandwidth efficiency.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.3
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• pp.453-460
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• 2014

Fault injection attack is the process of attempting to acquire the information on-chip through inject artificially generated error code into the cryptographic algorithms operation (or perform) which is implemented in hardware or software. From the details above, the laser-assisted failure injection attacks have been proven particularly successful. In this paper, we propose an improved laser probing system for fault injection attack which is called the Dual-Laser FA tool set, a hybrid approach of the Flash-pumping laser and fiber laser. The main concept of the idea is to improve the laser probe through utilizing existing equipment. The proposed laser probe can be divided into two parts, which are Laser-I for laser cutting, and Laser-II for fault injection. We study the advantages of existing equipment, and consider the significant parameters such as energy, repetition rate, wavelength, etc. In this approach, it solves the high energy problem caused by flash-pumping laser in higher repetition frequency from the fiber laser.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.1 s.47
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• pp.9-16
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• 2006

The design practice of the lateral resisting system has been traditionally dependent on the experience and know-how of a structural engineer. And the method to reflect the evaluation results of building's capacity on design process doesn't exist. The proposal of a rational design of the lateral load resisting system is based on the available full capacity $(R_{ac})$ of a building and the minimum required capacity $(R_{code})$ suggested in the code. This study suggests thai nonlinear static analysis, which is the estimation of the lateral capacity with the pushover analysis, be included in the existing design procedure of the structure. After finishing the basic structural design, the lateral resisting capacity ol a building is estimated. At the phase of nonlinear static analysis, pushover analysis is peformed to define the fully yielded baseshear $(V_Y)$. When the design wind baseshear $(V_{wind})$ is bigger than the design seismic baseshear $(V_D)$, the value is checked to determine whether or not it is smaller than the $V_Y$. After confirming that it is smaller, the $R_{ac}$ of the structure is computed. If the $V_D$ is bigger at first, only the $R_{ac}$ is computed. When the value of the estimation shows remarkable differences with the $R_{code}$, repetition of the design modification is needed for those approximate to the $R_{code}$. Application of the proposed design procedure to 2-D steel braced RC buildings has proven to be efficient.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4A
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• pp.352-360
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• 2008

Recently Task Group (TG) 4 of the Institute of Electrical and Electronics Engineers (IEEE) 802.15a has been recommended a system with ranging capability in existence of multiple Simultaneous operating piconets (SOPs) as well as low-cost, low-power. According to the ranging service, coherent and non-coherent based ranging schemes using ternary code have been adopted as a standard. However it is hard to estimate an accurate time of arrival (TOA) in case of using direct sequence based TOA estimation method because pulse repetition interval (PRI) offered by TG is more limited than the maximum excess delay (MED) of channel. To mitigate inter pulse interference (IPI) problem, this paper proposes a non-coherent TOA estimation scheme using non-periodic transmission (NPT) pattern. The proposed receiver is based on a non-coherent energy detection considering with motivation of low rate wireless personal area network (LR-WPAN). TOA information is estimated via proper comparison with a prescribed threshold after the sliding correlation and search back window (SBW) process for reducing TOA error. To verify the performance of proposed ranging scheme, two distinct channel models approved by IEEE 802.15.4a TG are considered. According to the simulation results, we could conclude that the proposed scheme have performed better performance than the conventional method on the existence of multiple SOPs.

• The Korean Journal of Air & Space Law and Policy
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• v.35 no.1
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• pp.3-32
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• 2020

With controlling Drones, although it was discussed in the previous study which showed a possibility. Which is personality and property rights of third parties could be violated while operating the drone with a video camera. But It's hard to find out precedents related to drones in Korea. In case of that someone try to control the drone which is equipped with a camera in a yard of neighborhood, the German District Court (Potsdam) considered an operator of drone has little bit of careless to do his duty and admit nonfeasance claim in the owner of the one's property for prevention to repetition of similar situation according to a nonfeasance claim for prevention to Section 1004 (1) sentence 2 of the German Civil Code(BGB). The drone which is equipped with a camera have possibilities to disrupt property and personal rights of the owner. Because a danger in repetition is getting larger regarding the violation of law. Moreover, there is a case that someone shot down the drone which is equipped with a camer. Because it has a risk to interrupt private life and cause some dangerous in our life. The German district court(Riesa) recently have considered that controlling the drone with a camera in private spaces is illegal as a violation of personal life. In addtion to, the action of property owner shot down drone is a legal according to § 228 of the German Civil Code(BGB) which is caleed "Necessity". Although it is difficult to apply to foreign cases directly to Korea, similar cases are likely to be occurred in Korea. The decision of the German District Court showed implications to Korea. As demand for the camera-equipped drone increases in Korea, it is time to discuss specific measures for drone violations.

• Journal of Satellite, Information and Communications
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• v.8 no.4
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• pp.75-80
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• 2013

In this paper, the Ka-band maritime satellite communication systems for mobile terminals are proposed. The design includes the link budget analysis, determination of modulation and coding schemes and the overall structure of a transmitter. To avoid the harmful effects on the existing DVB-S2 services, the proposed maritime satellite system using the same spectrum with DVB-S2 at the same time employs the very wideband spreading transmission. Additionally, omni-directional low-gain antennas should be equipped in a mobile terminal to reduce the system cost. These two considerations limit the maximum transmission rate of the proposed system. Due to the limitations, the proposed system includes 36 dB or 39 dB spreading gain depending on the modulation scheme and a link-adaptive repetition method depending on the level of rain attenuation. To support short packets with minimal performance loss, the turbo code used in 3GPP instead of LDPC(low density parity check code) is adopted. By combining them, the overall structure of low-rate maritime satellite communication system is designed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.681-684
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• 2008

Bluetooth baseband performs FEC (forward error check) at the interface of transmitter and receiver modem. Well-designed FEC means directly the efficiency of retransmission of the data payload therefore design optimization is very important. In this paper, we designed a optimal 1/3, 2/3 type of FEC. 1/3 FEC. which performs 3 times customary repetition was designed for packet header, and 2/3 FEC was designed for data packets with (15, 10) reduced hamming code. The proposed hardware FEC block was described and verified using Verilog HDL and later to be automatically synthesized. The synthesized FEC block operated at 40Mhz normal clock speed of the target baseband microcontroller.