• Title/Summary/Keyword: IR system

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Performance Improvement of TH PPM UWB-IR System with CCI Canceller in Multi-User Interference Environment (다중 사용자 간섭 환경에서 CCI Canceller를 채용한 TH PPM UWB-IR 시스템의 성능 개선)

  • Lee Yang-Sun;Kang Heau-Jo
    • Journal of Digital Contents Society
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    • v.5 no.3
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    • pp.171-175
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    • 2004
  • In this paper, We applied CCI canceller to remove multi-user interference in co-channel environment and improved performance of TH PPM UWB-IR system. As a result, We could get reception performance that data transmission of high speed is available in small reception power applying CCI canceller. Also, We could get permission available channel capacity to maximum access number 40 in high speed transmission environment more than 100Mbps.

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People Counting and Coordinate Estimation Using Multiple IR-UWB Radars (다수의 IR-UWB 레이다를 이용한 인원수 및 좌표 추정 연구)

  • Tae-Yun Kim;Se-Won Yoon;In-Oh Choi;Joo-Ho Jung;Sang-Hong Park
    • IEMEK Journal of Embedded Systems and Applications
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    • v.19 no.1
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    • pp.39-46
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    • 2024
  • In this paper, we propose an efficient method for estimating the number of people and their locations using multiple IR-UWB radar sensors. Using three IR-UWB radar sensors in the indoor space, the measured signal from the target is processed to remove the clutter using rejection methods. Then, to further remove the clutter and to determine the presence of the human, the time-frequency image representing the micro-Doppler is obtained and classified by a convolutional neural network. Finally, the system finds the number of human objects and estimates each position in a two-dimensional space. In experiments using the measured data, the system successfully estimated the location and number of individuals with a high accuracy ≈ 88.68 %.

Computational Investigation of the Effect of Various Flight Conditions on Plume Infrared Signature (항공기 비행환경에 따른 플룸 IR 신호 영향성 연구)

  • Kim, Joon-Young;Chun, Soo-Hwan;Myong, Rho-Shin;Kim, Won-Cheol
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.3
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    • pp.185-193
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    • 2013
  • The plume infrared signature effects at various flight conditions of aircraft were investigated for the purpose of reducing infrared signature level. The nozzle of a virtual subsonic unmanned combat aerial vehicle was designed through a performance analysis. Nozzle and associated plume flowfields were first analyzed using a density-based CFD code and plume IR signature was then calculated on the basis of the narrow-band model. Finally, qualitative information for the plume infrared signature characteristics was obtained through the analysis of the IR signature effects at various flight conditions.

Pulse Repetition Based Selective Detection Scheme for Coherent IR-UWB Systems (Coherent IR-UWB 시스템을 위한 펄스 반복 전송 기반의 선택적 검출 기법)

  • Kim, Se-Kwon;Kim, Jae-Woon;Shin, Yo-An
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.45 no.3
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    • pp.19-26
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    • 2008
  • We propose a selective detection scheme based on pulse repetition considering the BER (Bit Error Rate) performance and complexity of coherent IR-UWB (Impulse Radio-Ultra Wide Band) systems. To take system complexity into account, the proposed scheme transmits the UWB signals by pulse repetition at the transmitter, like conventional PRC (Pulse Repetition Coding). However, to effectively improve BER performance of the system, the proposed scheme performs selective detection by estimating the SNR (Signal-to-Noise Ratio) of the received pulse-repeated signal at the UWB receiver. Hence, the proposed scheme effectively improves BER performance of the coherent IR-UWB systems without increasing system complexity, as compared to the conventional PRC algorithm.

The Design of Content using IR-Tracking System in the Spatial Virtual Reality Metaverse (공간 가상현실 메타버스내에서 IR-트래킹 시스템을 이용한 컨텐츠 설계)

  • Tae-Won Kim;Sang-Yoon Lee;Hyun-Woong Kim;Dae-Sol Lee;Dae-Sik Lee
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.16 no.5
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    • pp.247-255
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    • 2023
  • In order to create a virtual reality space in the metaverse, accurate tracking sensors and implementation are required. Most government agencies and corporations performs tracking to use their own tracking sensors and a base stations, such as VIVE. The VIVE method may have tracking problems due to spatial constraints and obstacles or nearby structures, and it is also that the number of people that can be accommodated within the space is also limited. In this paper, we designed and implemented metaverse using an IR sensor tracking system to freely track the spatial virtual reality metaverse, and we experimented contents in metaverse by placing IR sensors additionally on the floor and ceiling if needed in order to flexibly configure the metaverse space. As a result of the experiment, the tracking stability of the IR-tracking system was approximately 12% higher than the VIVE method. Additionally, adding more tracking sensors on the floor increases tracking stability and allows for a stable representation of virtual space.

Compiler triggered C level error check (컴파일러에 의한 C레벨 에러 체크)

  • Zheng, Zhiwen;Youn, Jong-Hee M.;Lee, Jong-Won;Paek, Yun-Heung
    • The KIPS Transactions:PartA
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    • v.18A no.3
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    • pp.109-114
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    • 2011
  • We describe a technique for automatically proving compiler optimizations sound, meaning that their transformations are always semantics-preserving. As is well known, IR (Intermediate Representation) optimization is an important step in a compiler backend. But unfortunately, it is difficult to detect and debug the IR optimization errors for compiler developers. So, we introduce a C level error check system for detecting the correctness of these IR transformation techniques. In our system, we first create an IR-to-C converter to translate IR to C code before and after each compiler optimization phase, respectively, since our technique is based on the Memory Comparison-based Clone(MeCC) detector which is a tool of detecting semantic equivalency in C level. MeCC accepts only C codes as its input and it uses a path-sensitive semantic-based static analyzer to estimate the memory states at exit point of each procedure, and compares memory states to determine whether the procedures are equal or not. But MeCC cannot guarantee two semantic-equivalency codes always have 100% similarity or two codes with different semantics does not get the result of 100% similarity. To increase the reliability of the results, we describe a technique which comprises how to generate C codes in IR-to-C transformation phase and how to send the optimization information to MeCC to avoid the occurrence of these unexpected problems. Our methodology is illustrated by three familiar optimizations, dead code elimination, instruction scheduling and common sub-expression elimination and our experimental results show that the C level error check system is highly reliable.

Effect of composition and structure on exchange anisotropy of IrxMn(100-x)/NiFe films

  • Suh, Su-jung;Park, Young-suk;Ro, Jae-chul;Yong-sung;Yoon, Dae-ho
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1998.06a
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    • pp.91-95
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    • 1998
  • Exchange anisotropy between IrMn antiferromagnetic layer and NiFe ferromagnetic layer has been studied in IrxMn(100-x)/NiFe/Buffr/Si(100) films deposited by D. C. magnetron sputtering method. Among Zr, Ta, and Cu used as buffer layer, Zr and Ta enhanced the fcc(111) texture of NiFe and IeMn layer, but Cu did not affect microstructure of those layer. Strong fcc(111) texture of IrMn layer was confirmed to be the origin of exchange anisotropy of IrMn. Ir composition control in IrMn layer showed that {{{{ gamma -phase}}}} IrMn is stabilized between 10 and 30 at % Ir, an 21 at. % Ir in IrMn layer was optimum composition that showed maximum exchange anisotropy field. above 200 ${\AA}$ thickness of IrMn, antiferromagnetic property is stabilzed to show saturated exchange anisotropy field. Based pressure was confirmed to be critical requisite in IrMn-based spin-valve GMR system.

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A Study on the Implementation and Performance Evaluation of Full-text Information Retrieval System based on Scientific Paper′s Content Structure (학술논문의 내용구조에 의한 전문검색시스템 구현과 성능평가에 관한 연구)

  • 이두영;이병기
    • Journal of the Korean Society for information Management
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    • v.15 no.3
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    • pp.73-93
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    • 1998
  • Conventional full-text information retrieval system has been proved with high recall ratio and low precision ratio. One of the disadvantages of full-text IR system is that it is not designed to reflect the user's information need. It is due to the fact that full-text IR system has been designed based on physical and logical structure of document without considering the content of document. The purpose of the study is to develop more effective full-text IR system by resolving such disadvantages of conventional system. The study has developed new method of designing full-text IR system by using Content Structure Markup Language(CSML) other than conventioanal SGML.

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IR's Interface Designs for the Science and Technology Information Service System (과학기술정보유통 서비스용 검색 표준인터페이스 설계)

  • 남영준;예용희
    • Journal of Korean Library and Information Science Society
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    • v.33 no.4
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    • pp.261-281
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    • 2002
  • Interface is a communication mechanism between users md information system. This research suggests the guidelines for the user interface design in the IR system. For the development, we would survey and analyse the major library's IR interface windows. It is included in the guidelines md suggestions that IR's windows, data process icons and display's icons of the information retrieval results. So this research's results are utilized to the standard interface development fur the information services.

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Synthesis and Characterization of Phosphorescent Platinum and Iridium Complexes of 6-Chloro-3-phenylpyridazine

  • Lee, Sang-Jin;Seok, Kang;Lee, Jae-Sung;Lee, Seung-Hee;Hwang, Kwang-Jin;Kim, Young-Kwan;Kim, Young-Sik
    • Journal of Photoscience
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    • v.10 no.2
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    • pp.185-187
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    • 2003
  • The preparation and the photophysics of organometallic Pt(II) and Ir(III) complexes with 6-ch1oro-3-phenylpyridazine (H6Clppdz) are reported. $K_2$PtCl$_4$ and IrCl$_3$ㆍn$H_{2}O$ cleanly cyclometalate with H6Clppdz, forming the corresponding chloro-bridged dimers, (6Clppdz)Pt($\mu$-Cl)$_2$Pt(6Clppdz) and (6Clppdz)$_2$Ir($\mu$-Cl)$_2$Ir(6Clppdz)$_2$ in good yield. These chloro-bridged dimers are cleaved with acetylacetone (Hacac) to give the corresponding monomer, (6Clppdz)Pt(acac) and (6Clppdz)$_2$ Ir(acac), respectively. Both complexes show bright orange luminescence at room temperature and the emission wavelengths are different depending on the metal and the structure of complexes. (6Clppdz)Pt(acac) shows two sharp emission bands in shorter wavelength ($\lambda$$_{em}$=541 and 580 nm), while (6Clppdz)$_2$ Ir(acac) shows a broad emission band in longer wavelength ($\lambda$$_{em}$=615 nm). Strong spinorbit coupling due to the heavy metal atom allows for the formally forbidden mixing of the $^1$MLCT with the $^3$MLCT and $^3$$\pi$-$\pi$$^{*}$ states.

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