• The Journal of the Acoustical Society of Korea
• /
• v.38 no.1
• /
• pp.9-22
• /
• 2019

In this paper, we propose a method that can be applied to the efficient implementation of multi-channel active noise controller. Since the normalized MFxLMS (Modified Filtered-x Least Mean Square) algorithm for the multi-channel active noise control requires a large amount of computation, the difficulty has lied in implementing the algorithm using a low-cost MCU (Microcontoller Unit). We implement the multi-channel active noise controller efficiently by optimizing the software based on the features of the MCU. By maximizing the usage of single-cycle MAC (Multiply- Accumulate) operations and minimizing move operations of the delay memory, we can achieve more than 3 times the performance in the aspect of computational optimization, and by parellel processing using the auxillary processor included in the MCU, we can also obtain more than 4 times the performance. In addition, the usage of additional parts can be minimized by maximizing the usage of the peripherals embedded in the MCU.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2024.05a
• /
• pp.381-382
• /
• 2024

Open RAN(Radio Access Network)을 선도적으로 연구하고 있는 O-RAN Alliance에서는 Open RAN의 E2 인터페이스에서 발생 가능한 보안 위협 중 하나로 MitM(Man-in-the-Middle) 공격을 명시하였다. 그러나 이에 대응하기 위한 보안 요구사항으로는 3계층 보안 프로토콜인 IPsec 사용을 명시하고 있으며, 2계층 공격인 ARP(Address Resolution Protocol) 스푸핑에 대한 요구사항은 명시하고 있지 않다. 따라서 본 논문에서는 MitM 공격 중 하나인 ARP 스푸핑으로부터 E2 인터페이스를 보호하기 위해, Near-RT RIC의 ARP 테이블에서 E2 인터페이스로 연결되는 장비에 대한 MAC 주소를 정적으로 설정할 수 있는 xApp을 제안한다.

• KIPE Magazine
• /
• v.9 no.2
• /
• pp.26-30
• /
• 2004

전력전자 분야에서 사용되는 전동기 제어 시스템 또는 UPS, 능동필터 등 반도체 전력회로 제어에 다양한 신호처리와 고속연산이 가능하도록 하드웨어적으로 부동소숫점을 연산하거나 MAC 연산 기능 등이 있어 계산 속도가 빠르다는 장점 때문에 TMS320C3X등의 DSP가 많이 사용되어 왔다. 그런데 DSP는 입/출력 기능이 상당히 떨어지므로 외부에 A/D 변환기, EPLD 또는 FPGA 등의 외부소자 들이 많이 필요하여 회로가 상당히 복잡하다는 문제가 있었다. 이에 비하여 마이크로제어기는 입/출력 기능이 우수하나 연산속도가 상당히 떨어진다는 단점이 있다.(중략)

• Journal of Integrative Natural Science
• /
• v.2 no.1
• /
• pp.18-23
• /
• 2009

This minireview provides the chosen examples of our recent discoveries in the polymerization of hydrosilanes, dihydrosilole, lactones, and vinyl derivatives using various catalysts. Hydrosilanes and lactones copolymerize to give poly(lactone-co-silane)s with $Cp_2MCl_2$/Red-Al (M = Ti, Zr, Hf) catalyst. Hydrosilanes (including dihydrosilole) reduce noble metal complexes (e.g., $AgNO_3$, $Ag_2SO_4$, $HAuCl_4$, $H_2PtCl_6$) to give nanoparticles along with silicon polymers such as polysilanes, polysilole, polysiloxanes (and silicas) depending on the reaction conditions. Interestingly, phenylsilane dehydrocoupled to polyphenylsilane in the inert nitrogen atmosphere while phenylsilane dehydrocoupled to silica in the ambient air atmosphere. $Cp_2M/CX_4$ (M = Fe, Co, Ni; X = Cl, Br, I) combination initiate the polymerization of vinyl monomers. In the photopolymerization of vinyl monomers using $Cp_2M/CCl_4$ (M = Fe, Co, Ni), the photopolymerization of MMA initiated by $Cp_2M/CCl_4$ (M = Fe, Co, Ni) shows while the polymerization yield decreases in the order $Cp_2Fe$ > $Cp_2Ni$ > $Cp_2Co$, the molecular weight decreases in the order $Cp_2Co$ > $Cp_2Ni$ > $Cp_2Fe$. For the photohomopolymerization and photocopolymerization of MA and AA, the similar trends were observed. The photopolymerizations are not living. Many exciting possibilities remain to be examined and some of them are demonstrated in the body of the minireview.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.11
• /
• pp.11-18
• /
• 2014

Most of the energy efficient MAC protocols for wireless sensor networks (WSNs) are based on duty cycling in a single channel and show competitive performances in a small number of traffic flows; however, under concurrent multiple flows, they result in significant performance degradation due to contention and collision. We propose a multi-channel pipelining (MCP) method for convergecast WSN in order to address these problems. In MCP, a staggered dynamic phase shift (SDPS) algorithms devised to minimize end-to-end latency by dynamically staggering wake-up schedule of nodes on a multi-hop path. Also, a phase-locking identification (PLI) algorithm is proposed to optimize energy efficiency. Based on these algorithms, multiple flows can be dynamically pipelined in one of multiple channels and successively handled by sink switched to each channel. We present an analytical model to compute the duty cycle and the latency of MCP and validate the model by simulation. Simulation evaluation shows that our proposal is superior to existing protocols: X-MAC and DPS-MAC in terms of duty cycle, end-to-end latency, delivery ratio, and aggregate throughput.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.10a
• /
• pp.223-226
• /
• 2010

iPhone and Smart Phone domestic markets are activated with domestic coming out of galaxy S together and the users are increasing. It follows hereupon and with forensic techniques for the cellular phone relation criminal evidence collection of data of existing the mobile forensic engineering research is necessary in about Smart Phone where it has become new techniques and WiFi etc. Convergence. It respects Smart Phone OS star forensic technique and a tool research, iPhone Apple MAC OS X and it researches galaxy S Google Android from the present paper. Smart it uses SYN methods with Phone OS star forensic techniques and it researches in order mobile forensic description below it observes it sees and forensic application methods computer forensic methods and the tools and it researches forensic techniques. The present paper research as IT powerful country will contribute in Smart Phone forensic technical advances of Korea.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.12 no.2
• /
• pp.345-352
• /
• 2017

In this paper, we design and implement an educational robot system that can use scratch education with the function of user demanding to perform robot education in actual school site in an embedded environment. It is developed to enable physical education for sensing information processing, software design and programming practice training that is the basis of robotic system. The development environment of the system is Arduino Uno based product using Atmega 328 core, debugging environment based on Arduino Sketch, firmware development language using C language, OS using Windows, Linux, Mac OS X. The system operation process receives the control command of the server using the Bluetooth communication, and drives various sensors of the educational robot. The curriculum includes Scratch program and Bluetooth communication, which enables real-time scratch training. It also provides smartphone apps and is designed to enable education like C and Python through expansion. Teachers at the school site used the developed products and presented performance processing results satisfying the missionary needs of the missionaries.

• IEIE Transactions on Smart Processing and Computing
• /
• v.6 no.2
• /
• pp.133-139
• /
• 2017

Vehicles have increasingly evolved and become intelligent with convergence of information and communications technologies (ICT). Vehicle communications (VC) has become one of the major necessities for intelligent vehicles. However, VC suffers from serious security problems that hinder its commercialization. Hence, the IEEE 1609 Wireless Access Vehicular Environment (WAVE) protocol defines a security service for VC. This service includes Advanced Encryption Standard-Counter with CBC-MAC (AES-CCM) for data encryption in VC. A high-speed AES-CCM crypto module is necessary, because VC requires a fast communication rate between vehicles. In this study, we propose and implement an efficient AES-CCM hardware architecture for high-speed VC. First, we propose a 32-bit substitution table (S_Box) to reduce the AES module latency. Second, we employ key box register files to save key expansion results. Third, we save the input and processed data to internal register files for secure encryption and to secure data from external attacks. Finally, we design a parallel architecture for both cipher block chaining message authentication code (CBC-MAC) and the counter module in AES-CCM to improve performance. For implementation of the field programmable gate array (FPGA) hardware, we use a Xilinx Virtex-5 FPGA chip. The entire operation of the AES-CCM module is validated by timing simulations in Xilinx ISE at a speed of 166.2 MHz.

• 한국HCI학회:학술대회논문집
• /
• 2007.02b
• /
• pp.249-255
• /
• 2007

컴퓨터 하드웨어 및 소프트웨어의 발전으로 그래픽 처리 기술은 날로 발전을 거듭하고 있으며 하드웨어의 기능을 최대한 이끌어내기 위한 소프트웨어 기술 또한 발전하고 있다. 이러한 발전으로 인하여 다양한 영상처리 분야에서 빠른 이미지 프로세싱이 가능하게 되었지만 빠른 이미지 프로세싱 능력에도 불구하고 프로그래밍 기술은 기존 것을 고수하고 있다. 일반적으로 사용해오던 기술은 높은 프로그래밍 지식을 필요로 하는 분야였고 이러한 이유로 이미지 프로세싱 기법을 전문적인 프로그래밍 지식이 부족한 예술계의 사용자가 이용하는 데에는 어려움이 있었다. 이러한 문제점을 해결하고 이미지 하드웨어 및 소프트웨어의 효율적인 사용 환경을 위하여 Apple사에서 OpenGL과 Objective-C를 이용한 좀더 간단한 이미지 프로세싱 기법인 코어 이미지(Core Image)를 개발하였다. OS와 어플리케이션 상에서 빠른 이미지 프로세싱을 위해 개발된 코어 이미지는 기존의 이미지 프로세싱 기법에서 복잡한 형태의 프로그래밍을 요했던 것과는 달리, 여러 이미지 프로세싱 기법을 간단한 플러그인 형태로 지원한다. 예술적인 측면에서 다양한 이미지 프로세싱 기법을 보다 손쉽게 사용할 수 있으며 사용 방법 또한 간단하여 전문적인 프로그램 지식이 부족한 일반 사용자도 예술적인 측면에서 이미지 프로세싱 기술을 쉽게 접목할 수 있도록 구성되어 있다. 하지만 코어 이미지가 국내에서는 소수의 사용자만이 이용하는 Mac OS에서만 사용 가능한 프로세싱 기술이라는 문제점 또한 지니고 있다. 본 논문에서는 코어 이미지의 개념과 구동 원리 및 실제 예술 작품에 적용된 사례를 분석하고, 이를 통하여 다양한 분야에서의 코어 이미지의 가능성에 대하여 전망해 본다.

• Journal of the Korea Society of Computer and Information
• /
• v.19 no.3
• /
• pp.63-71
• /
• 2014

We analyze the execution time of Reed-Solomon coding, which is the MAC-layer forward error correction scheme used in CDMA2000 1xEV-DO broadcast services, under different air channel conditions. The results show that the time constraints of MPEG-4 cannot be guaranteed by Reed-Solomon decoding when the packet loss rate (PLR) is high, due to its long computation time on current hardware. To alleviate this problem, we propose three error control schemes. Our static scheme bypasses Reed-Solomon decoding at the mobile node to satisfy the MPEG-4 time constraint when the PLR exceeds a given boundary. Second, dynamic scheme corrects errors in a best-effort manner within the time constraint, instead of giving up altogether when the PLR is high; this achieves a further quality improvement. The third, video-aware dynamic scheme fixes errors in a similar way to the dynamic scheme, but in a priority-driven manner which makes the video appear smoother. Extensive simulation results show the effectiveness of our schemes compared to the original FEC scheme.