• Title/Summary/Keyword: Peak code

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Determination of Single Escape and Double Escape Peak Efficiency for a HPGe Detector

  • Park Chang Su;Sun Gwang Min;Choi H.D.
    • Nuclear Engineering and Technology
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    • v.35 no.6
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    • pp.523-528
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    • 2003
  • The efficiencies of single escape and double escape peaks were calculated by using Monte Carlo method and compared with measured efficiencies. The efficiency was obtained from the area ratio of escape peak to full energy absorption peak and the full energy absorption peak efficiency. For the escape peak interfered with other $\gamma-ray$ peaks, the net area was obtained by area correction. The GEANT code developed in CERN was used for the Monte Carlo calculation. The calculated efficiencies of the escape peaks agreed with the measurement within $12\%$.

Characteristics of Negative Peak Wind Pressure acting on Tall Buildings with Step on Wall Surface

  • Yoshida, Akihito;Masuyama, Yuka;Katsumura, Akira
    • International Journal of High-Rise Buildings
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    • v.8 no.4
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    • pp.283-290
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    • 2019
  • Corner cut, corner chamfered or a building shape change are adopted in the design of tall buildings to achieve aerodynamic superiority as well as response reduction. Kikuchi et.al pointed out that large negative peak external pressures can appear near the inside corner of set-back low rise buildings. It is therefore necessary to pay attention to facade design around steps in building surfaces. Peak wind pressures for corner cut or corner chamfered configurations are given in the AIJ code. However, they cannot be applied where there are many variations of vertical and horizontal steps. There has been no previous systematic research on peak wind pressures around steps in building surfaces. In this study, detailed phenomenon of peak wind pressures around steps in buildings are investigated focusing on vertical and horizontal distances from the building's corner.

A New Type of Complementary Code Keying Orthogonal frequency Division Multiplexing (CCK-OFDM) Wireless LAN Modem (새로운 방식의Complementary Code Keying Orthogonal Frequency Division Multiplexing (CCK-OFDM) 무선랜 모뎀에 관한 연구)

  • 정원정;박현철
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.8C
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    • pp.1069-1075
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    • 2004
  • In this paper, we show the equivalence between complementary code keying (CCK) codeword and coset of the first order Reed-Muller (RM) code with variables of three. The CCK codewords are Golay sequences which have peak-to-average power ratio (PAPR) of two at most and can correct one error. We propose a CCK-orthogonal frequency division multiplexing (OFDM) modem to reduce PAPR. Also, we present the performance improvement techniques by increasing the variables of four to correct three errors and reduce PAPR at least 9㏈ with this system. Although, two Fast Hadamard Transform (FHT) blocks of size 8 64 are required at the receiver, we reduce the complexity by using FHT blocks of size 8 64 and 2 4 without deteriorating the performance. We generalize our results that we may increase the variables of RM code to enhance the error correcting and PAPR reduction capabilities without increasing receiver's complexity.

Performance Analysis of Multicarrier Code Select CDMA System for PAPR Reduction in Multipath Channels

  • Ryu, Kwan-Woong;Jin, Jiyu;Park, Yong-Wan;Choi, Jeong-Hee
    • Journal of Communications and Networks
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    • v.11 no.1
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    • pp.11-19
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    • 2009
  • Multicarrier direct sequence code division multiple access (MC DS-CDMA) is an attractive technique for achieving high data rate transmission. This is valid regardless of whether or not the potentially large peak-to-average power ratio (PAPR) is an important factor for its application. On the other hand, code select CDMA (CS-CDMA) is an attractive technique with constant amplitude transmission of multicode signal regardless of subchannels. This is achieved by introducing a code select method. In this paper, we propose a new multiple access scheme based on the combination of MC DS-CDMA and CS-CDMA. The proposed scheme, which we call MC CS-CDMA, includes as special cases the subclasses of MC DS-CDMA and CS-CDMA. This paper investigates the performance of these systems over a multipath frequency selective fading channel using a RAKE receiver with maximal ratio combiner. In addition, the PAPR of the proposed system is compared with that of both MC DS-CDMA and CS-CDMA. Simulation results demonstrate that the proposed system provides better PAPR reduction than MC DS-CDMA, at the expense of the complexity of the receiver and the number of available users. The numerical result demonstrates that the proposed system has better performance than MC DS-CDMA due to the increased processing gain and time diversity gain.

A Study on the Relationship of [a] Sound Wave to Sasang Constitution - by Sasang Constitution Analysed with PSSC-2004 ([a] 음성파형과 사상체질과의 상관성연구 - 사상체질음성분석기(四象體質音聲分析機)(PSSC-2004)를 이용하여)

  • Yoon, Woo-Young;Choi, Min-Ki;Jung, Woon-Ki;Lee, Sang-Jun;Kim, Dal-Rae;Yoo, Jun-Sang
    • Journal of Sasang Constitutional Medicine
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    • v.18 no.2
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    • pp.83-95
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    • 2006
  • 1. Objectives and Methods The purpose of this study was to objectify the diagnosis of Sasang constitution. It analyzed the adult male and female voices into 23factors using PSSC-2004. The study was conducted by subjects inputting 2.5-3 sec of [a] in 586 men and women's voices to PSSC-2004. The statistical analyses are applied to three groups: total group, male group, female group. The group with a total of 586 was composed of 155 Soyangin, 230 Taeumin and 201 Soeumin. The male group was composed with 61 Soyangin, 127 Taeumin and 87 Soeumin. The female group was composed with 94 Soyangin, 103 Taeumin and 114 Soeumin. Taeyangin were excluded for a more accurate statistical analysis. 2. Results (I) In total group, Taeumin's peak sum was significantly high compared with the others(P=0.021). It was significant for distinction between Taeumin and Soyangin at the result of post mortem. (2) In total group, the Soyangin's rank6, rank7 and rank8 were significantly high compared with the others (P=0.050)(0.043)(0.034). (3) In total group, the Soyangin's rank9 was significantly high compared with the others(P=0.025). It was significant for distinction between Taeumin and Soyangin at the result of post mortem. (4) In male group, the Soyangin's code3 was significantly high compared with the others(P=0.050). (5) In male group, the Soyangin's code1 was significantly low compared with the others(P=0.004). It was significant for distinction between Taeumin and Soyangin at the result of post mortem. (6) In male group, the Soyangin's rank1, rank2, rank3 and rank4 were significantly high compared with the others(P=0.017)(0.008) (0.005)(0.002). They were significant for distinction between Taeumin and Soyangin at the result of post mortem. (7) In female group, the Taeumin's code1 was significantly low compared with the others(P=0.016). It was significant for distinction between Taeumin and Soeumin at the result of post mortem. 3. Conclusion From above result, there is the possibility of efficiency standard gide for constitutional diagnosis by analyzation of the voices.

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Seasonal Variations in Populations of Small Fishes Concentrated in Shoalgrass and Turtlegrass (Shoalgrass와 turtlegrass에 棲息하는 小型魚類 個體群들의 季節的 變動에 관한 硏究)

  • Huh, Sung-Hoi
    • 한국해양학회지
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    • v.19 no.1
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    • pp.44-55
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    • 1984
  • Abundances of small fishes that utilized seagrass meadows of Redfish Bay, Texas, were analyzed quantitatively to determine monthly changes of this concentrated subtropical fish community during 1982-1983. an effective quantitative sampler, a 1-㎡ thrown cage, yielded a total of 10,223 fishes that comprised 40 species in 23 families, with average total densities about 15 fishes/㎡ in shoalgrass meadow and 6 fishes/㎡ in turtlegrass meadow. The darter goby, pinfish, code goby, and Gulf pipefish were the four most abundant species, and accounted for approximately 85% of the number of fish collected. However, the two different meadows had different relative abundances of fishes. The darter goby numerically dominated shallower shoalgrass meadow, while the pinfish and code goby were the commonest fishes in deeper turtlegrass meadow. Seasonal changes in both species composition and abundances of fish populations were major characteristics in these subtropical seagrass medows. Peak abundance of total fishes occurred during spring, with a secondary peak in fall. Lowest abundance of total fishes occurred in winter. Each abundant species showed its own seasonal abundance pattern, and had a peak abundance 1-3 months separated from other species, with some overlap of increased larval recruitment. Such distinct seasonal abundance patterns with different times of peak recruitment. Such distinct seasonal abundance patterns with different times of peak recruitment among fish species seem to permit use of the seagrass habitats with reduced, seasonal competition.

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Bar-Code Shape UHF RFID Tag Antenna (바코드 모양의 UHF RFID 태그 안테나 설계)

  • Jeon, Byung-Don;Chung, You-Chung
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.1
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    • pp.131-134
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    • 2012
  • A bar-code shape UHF RFID tag antenna is designed and fabricated with silver conductive ink. It can be recognize by both bar-code scanner and RFID reader. The bar-code shape is taken from a general box of a product, and the product code of the bar-code is used for the antenna design. The tag antenna is fabricated with silver conductive ink using a T-matching structure. The designed tag antenna is satisfied with bar-code system and RFID system simultaneously. The input reflection coefficient characteristics and the reading range pattern are measured. The peak reading range is about 111 cm, which is long enough.

Performance Improvement of Multi-Code Parallel Combinatory CDMA Systems Using Bi-Orthogonal Modulation under Multipath Fading Environment (다중 경로 페이딩 채널에서 Bi-orthogonal Modulation을 이용한 Multi-code Parallel Combinatory CDMA System의 성능 개선)

  • 임승환;신요안
    • Proceedings of the IEEK Conference
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    • 2000.11a
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    • pp.245-248
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    • 2000
  • In this paper, we present the performance of a multi-code parallel combinatory CDMA system using bi-orthogonal modulation under multipath fading channel. In general, the dynamic range of the amplitude of the transmit signal is very large in conventional multi-code CDMA systems, resulting in severe nonlinear distortion due to high power amplifier and thus significant BER performance degradation. Since the number of simultaneously multiplexed code channels in the proposed system is reduced, the proposed system exhibits reduction of peak-to-average power ratio (PAPR) of the transmit signal amplitude with significant BER improvement. We verify the performance of the proposed system by computer simulations under the Vehicular B multipath fading channel model by ARIB.

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NC Code Optimization Based on an Improved Cutting Force Model (향상된 절삭력 모델 기반의 NC 코드 최적화)

  • 이한울;고정훈;조동우
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.37-42
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    • 1997
  • Off-line feed rate scheduling is an advanced methodology to automatically determine optimum feed rates for the optimization of NC code. However, the present feed rate scheduling systems have lim~tations to generate the optimized NC codes because they use the material removal rate or non-generalized cutting force model. In this paper, a feed rate scheduling system based on an improved cutting force model that can predrct cutting forces exactly in general machining was presented. Original blocks of NC code were divided to small ones with the modified feed rates to adjust the peak value of cutting forces to a constant vale. The characteristic of acceleration and deceleration for a given machrne tool was considered when off-line feed rate scheduhng was performed. Software for the NC code optimization was developed and applied to pocket machining simulation.

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A review of seismic design recommendations in Jordan

  • Saffarini, Hassan S.
    • Structural Engineering and Mechanics
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    • v.9 no.3
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    • pp.257-268
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    • 2000
  • The seismic design recommendations of the Jordan Code for Loads and Forces (JC) are evaluated, based on comparisons with analytical studies and the Uniform Building Code. It was established that the overall safety ensured by the implementation of these recommendations is not consistent with the established seismic risk in Jordan and the intended objectives of the code. A new zoning map is proposed with effective peak ground acceleration values. The different period formulae of the code were studied and were found to grossly underestimate the fundamental period when compared with analytically derived values or other codes' formulae. Other factors including the dynamic, soil, importance and behavior factors are discussed. It was determined that the JC's lateral load distribution formulae clearly lead to smaller internal forces than both dynamic analysis and UBC loads, even when those loads are normalized to give the same base shear. The main reason for this is attributed to the limited allowance for a backlash force in the JC.