• Title/Summary/Keyword: perfect number

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Efficient distributed estimation based on non-regular quantized data

  • Kim, Yoon Hak
    • Journal of IKEEE
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    • v.23 no.2
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    • pp.710-715
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    • 2019
  • We consider parameter estimation in distributed systems in which measurements at local nodes are quantized in a non-regular manner, where multiple codewords are mapped into a single local measurement. For the system with non-regular quantization, to ensure a perfect independent encoding at local nodes, a local measurement can be encoded into a set of a great number of codewords which are transmitted to a fusion node where estimation is conducted with enormous computational cost due to the large cardinality of the sets. In this paper, we propose an efficient estimation technique that can handle the non-regular quantized data by efficiently finding the feasible combination of codewords without searching all of the possible combinations. We conduct experiments to show that the proposed estimation performs well with respect to previous novel techniques with a reasonable complexity.

Evaluation Method of College English Education Effect Based on Improved Decision Tree Algorithm

  • Dou, Fang
    • Journal of Information Processing Systems
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    • v.18 no.4
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    • pp.500-509
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    • 2022
  • With the rapid development of educational informatization, teaching methods become diversified characteristics, but a large number of information data restrict the evaluation on teaching subject and object in terms of the effect of English education. Therefore, this study adopts the concept of incremental learning and eigenvalue interval algorithm to improve the weighted decision tree, and builds an English education effect evaluation model based on association rules. According to the results, the average accuracy of information classification of the improved decision tree algorithm is 96.18%, the classification error rate can be as low as 0.02%, and the anti-fitting performance is good. The classification error rate between the improved decision tree algorithm and the original decision tree does not exceed 1%. The proposed educational evaluation method can effectively provide early warning of academic situation analysis, and improve the teachers' professional skills in an accelerated manner and perfect the education system.

Provably-Secure and Communication-Efficient Protocol for Dynamic Group Key Exchange (안전성이 증명 가능한 효율적인 동적 그룹 키 교환 프로토콜)

  • Junghyun Nam;Jinwoo Lee;Sungduk Kim;Seungjoo Kim;Dongho Won
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.14 no.4
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    • pp.163-181
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    • 2004
  • Group key agreement protocols are designed to solve the fundamental problem of securely establishing a session key among a group of parties communicating over a public channel. Although a number of protocols have been proposed to solve this problem over the years, they are not well suited for a high-delay wide area network; their communication overhead is significant in terms of the number of communication rounds or the number of exchanged messages, both of which are recognized as the dominant factors that slow down group key agreement over a networking environment with high communication latency. In this paper we present a communication-efficient group key agreement protocol and prove its security in the random oracle model under the factoring assumption. The proposed protocol provides perfect forward secrecy and requires only a constant number of communication rounds for my of group rekeying operations, while achieving optimal message complexity.

Performance Improvement of Asunchronous DS-CDMA Systems with a Multistage Interference Canceller in the Presence of Timing and Phase Errors (칩 동기 에러와 위상 에러가 존재하는 환경에서 다단 간섭제거기에 의한 비동기 DS-CDMA 시스템의 성능 개선)

  • 김봉철;강근정;오창헌;조성준
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.1
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    • pp.1-10
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    • 2001
  • In this paper, a multistage parallel interference canceller (MPIC) and a partial multistage parallel interference canceller (PMPIC) are employed as a technique for improving the performance of the asynchronous DS-CDMA systems. The degree of the effect of the timing errors and phase errors on the interference cancellation capability of two types of cancellers is theoretically analyzed and the computer simulation is performed to confirm the analytical results. From the results, the large performance improvement is obtained by employing MPIC and PMPIC with perfect synchronization over the conventional matched filter, and the performance improvement obtained by MPIC and PMPIC is very close to each other as the number of the stage of MPIC and PMPIC increases. When the timing errors and phase errors are considered (in the case of imperfect synchronization), the performance improvement reduces as the performance degradation at the first stage (no cancellation) has a bad effect on the decision statistics at each stage. However MPIC and PMPIC have the strong interference cancellation capability in spite of imperfect synchronization as the number of the stage increases. An interference canceller, which has the strong interference cancellation capability as well as lower complexity for the implementation, is needed for practical systems with timing errors and phase errors because the perfect synchronization is impossible. Therefore, the excellent tradeoff between complexity and performance offered by PMPIC makes it an attractive approach for practical systems.

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Mapping of the Reduced Culm Number Trait in Rice (Oryza sativa L.) rcn10(t) Mutant

  • Yeo, Un-Sang;Lee, Jong-Hee;Kim, Choon-Song;Jeon, Meong-Gi;Oh, Tae-Yong;Han, Chang-Deok;Shin, Mun-Sik;Oh, Byeong-Geun
    • Korean Journal of Breeding Science
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    • v.40 no.3
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    • pp.223-227
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    • 2008
  • In rice, tillering is an important trait determining yield. To study tillering at the agricultural and molecular aspects, we have examined a spontaneous rice mutant that showed reduction in the number of culms. The mutant was derived from a $F^6$ line of the cross of Junambyeo*4 / IR72. It could produce, on average, 4 tillers per hill in the paddy field while wild-type plants usually have 15. Except the reduced culm numbers, they also show pale green phenotypes. The phenotypes of this mutant were co-segregated as the monogenic Mendelian ratio (${\chi}^b=0.002$, p=0.969). In order to locate a gene responsible for the rcn phenotype, the mutant with the japonica genetic background was crossed with Milyang21 of the indica background. Bulked segregant analysis was used for rapid determination of chromosomal location. Three SSR markers (RM551, RM8213, and RM16467) on chromosome 4 were genetically associated with the mutant phenotype. Each of the 217 $F_2$ plants was genotyped with simple sequence length polymorphisms. The data showed that RM16572 on chromosome 4 was the closest marker that showed perfect co-segregation among the $F_2$ population. We suggest the new rcn gene studied here name as $rcn10^t$ because there was no report which exhibit a rcn phenotype with a pleiotropic effect of pale green (chlorophyll deficiency), and mapped at same position on chromosome 4.

Performance Analysis of Space-time Coded MIMO System with Discrete-rate Adaptive Modulation in Ricean Fading Channels

  • Yu, Xiangbin;Rui, Yun;Yin, Xin;Chen, Xiaomin;Li, Mingqi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.10
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    • pp.2493-2508
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    • 2012
  • The performance of a MIMO system with adaptive modulation (AM) and space-time coding over Ricean fading channels for perfect and imperfect channel state information (CSI) is presented. The fading gain value is partitioned into a number of regions by which the modulation is adapted according to the region the fading gain falls in. Under a target bit error rate (BER) constraint, the switching thresholds for AM are given. Based on these results, we derive the calculation formulae of the theoretical spectrum efficiency (SE) and average BER. As a result, closed-form SE expression and accurate BER expression are respectively obtained. Besides, using the approximation of complementary error function, a tightly closed-form approximation of average BER is also derived to simplify the calculation of accurate theoretical BER. Computer simulation shows that the theoretical SE and BER are in good agreement with the corresponding simulation, and the approximate BER is also close to the accurate one. The results show that the AM scheme in Ricean fading channel provides better SE than that in Rayleigh fading channel due to the direct-path propagation, and has performance degradation in SE and BER for imperfect CSI.

Fast and Brand-Specific Calibration of Fuel-efficient Powertrains

  • Dobes, Thomas;Leithgoeb, Rainer;Bachler, Johann;Schoeggi, Peter
    • Journal of the korean Society of Automotive Engineers
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    • v.25 no.4
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    • pp.74-82
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    • 2003
  • Future emission legislation requirements especially the need for CO$_2$ reduction lead to more complex powertrain concepts with an increasing number of independent parameters to be calibrated. For gasoline engines concepts with variable valve timing, direct injection or variable charge motion are in development or already on production. Diesel engines with common rail systems offer a wide range of new injection strategies, the application of new exhaust aftertreatment systems leads to additional complexity. Furthermore a clear trend to highly sophisticated transmission concepts requires a perfect interaction of all powertrain components. While the higher complexity requires increasing test and development effort, the development duration is reduced significantly. Consequently, the potential of such systems cannot be fully utilised by traditional development and calibration approaches within the given timeframe. By introduction of intelligent methodologies f3r the calibration of modem powertrains the development becomes more efficient, faster and better in quality. However, even with standardised and automated calibration methods a differentiated brand-specific powertrain character has to be maintained comparable to a "handmade" calibration performed by highly experienced experts.

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The 7th earth science curriculum and comparative analysis of contents that is exhibited in the science museum - laying stress on high school earth science I, II (제 7차 지구과학 교육과정과 과학관 전시 내용의 비교 분석 - 고등학교 지구과학 I, II를 중심으로)

  • Lee, Hye-Jung;Lee, Chang-Zin;Shin, Myeong-Kyeong
    • 한국지구과학회:학술대회논문집
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    • 2005.09a
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    • pp.323-330
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    • 2005
  • In this study, searched how science museum reflects personality of course of study and target comparing display contents of science museum with high school earth science Ⅰand Ⅱ of the 7th curriculum. Result of this study is as following. First, area that earth science contents of course of study are exhibited has been less than 50%, and is preponderated by unit. Second, earth science course of study reflection degree of science museum is middle.(2.8 points of perfect score 5 points) Third, number of average mark of contents that is exhibited by science museum in significance level 0.05 lows is difference, and it is no difference by unit.

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Identification of First-order Plus Dead Time Model from Step Response Using HS Algorithm (HS 알고리즘을 이용한 계단응답으로부터 FOPDT 모델 인식)

  • Lee, Tae-Bong
    • Journal of Advanced Navigation Technology
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    • v.19 no.6
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    • pp.636-642
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    • 2015
  • This paper presents an application of heuristic harmony search (HS) optimization algorithm for the identification of linear continuous time-delay system from step response. Identification model is first-order plus dead time (FOPDT), which describes a linear monotonic process quite well in most chemical processes and HAVC process and is often sufficient for PID controller tuning. This recently developed HS algorithm is conceptualized using the musical process of searching for a perfect state of harmony. It uses a stochastic random search instead of a gradient search so that derivative information is unnecessary. The effectiveness of the identification method has been demonstrated through a number of simulation examples.

Synthesis and Photosensitive Properties of Poly[N-(formyloxyphenyl)maleimide] Containing Photosensitive Groups (Poly[N-(formyloxyphenyl)maleimide] 고분자의 합성과 자외선에 대한 반응특성)

  • Kim, Sang-Min
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.10 no.1
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    • pp.55-62
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    • 2004
  • Synthesis of poly[N-(formyloxyphenyl)maleimide](PFOMI) as photopolymer were investigated with various kinds of photosensitive groups. Generally, photopolyimide have some deficiencies in solubility, sensitivity, reserve stability of the photosensitive solution, and the precision of image pattern. The study has been required on those polymers which have high glass transition temperature and photo efficiency, and low dielectricity. The existing condensation resins require high curing temperature and perfect elimination of subreacted materials that are produced during the process after irradiation and various membrane damages such as the deformation and contraction in image pattern cure. In this study poly[N-(hydroxyphenyl)maleimide](PHPMI) was synthesized. The PHPMI were analyzed by H-NMR and FT-IR. The measured number average molecular weight of PHPMI was produced was $1.06{\times}10^4$. Poly[N-(formyloxyphenyl)maleimide](PFOMI) as a type of photo-Fries rearrangement was synthesized by NHPMI and formic acid followed by radical polymerization. PFOMI was analyzed by FT-IR, and photocharacteristics was investgated by UV spectra and FT-IR before and after UV irradiation. Based on the image characteristics of PFOMI measured from optical micrographs, it was formed that the resolution of positive type PFOMI was $0.5{\mu}m$.

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