• 제목/요약/키워드: analytical expression

검색결과 367건 처리시간 0.026초

가우시안 동일 채널 간섭하에서 BPSK 신호의 최적 단일 사용자 검출의 정확한 BER 수식 (Analytical BER Expression of the Optimal Single User Detection of a BPSK Signal in the Presence of a Gaussian CCI)

  • 정규혁
    • 한국통신학회논문지
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    • 제39A권9호
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    • pp.491-496
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    • 2014
  • We derive an analytical expression for the bit-error rate (ber) of optimal single user detection (osud) of a binary phase-shift keying (bpsk) signal corrupted by a gaussian cochannel interferer (cci). the channel capacity is also calculated to investigate the ber performance.

ESTIMATIONS OF HEAT CAPACITIES FOR ACTINIDE DIOXIDE: UO2, NpO2, ThO2, AND PuO2

  • Eser, E.;Koc, H.;Gokbulut, M.;Gursoy, G.
    • Nuclear Engineering and Technology
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    • 제46권6호
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    • pp.863-868
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    • 2014
  • The evaluation of thermal properties of actinide oxide fuels is a problem of high importance for the development of new generation reactors. In the present study, an expression obtained for n-dimensional Debye functions is used to derive a simple analytical expression for the specific heat capacity of nuclear fuels. To test the validity and reliability of this expression, the analytical expression is applied to $UO_2$, $NpO_2$, $ThO_2$, and $PuO_2$. It is seen that the formula was in agreement with the experimental and theoretical results reported in the literature.

Analytical Calculation of the 3D Magnetic Field Created by Non-Periodic Permanent Magnet Arrays

  • Zhang, He;Kou, Baoquan;Li, Liyi
    • Journal of international Conference on Electrical Machines and Systems
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    • 제1권3호
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    • pp.289-294
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    • 2012
  • In this paper, the three-dimensional magnetic field created by non-periodic magnet arrays is calculated analytically. The analytical expression of the magnetic field is derived by using a magnetic charge model. The influence of ferromagnetic boundaries is formulated with an image method. Finally, we compare the results determined by analytical calculations to those from a finite element simulation.

Distortional buckling of cold-formed lipped channel columns subjected to axial compression

  • Zhou, Wangbao;Jiang, Lizhong
    • Steel and Composite Structures
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    • 제23권3호
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    • pp.331-338
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    • 2017
  • Cold-formed lipped channel columns (CFLCCs) have been widely used in light gauge steel constructions. The distortional buckling is one of the important buckling modes for CFLCCs and the distortional buckling critical load depends significantly on the rotational restrain stiffness generated by the web to the lipped flange. First, a simplified explicit expression for the rotational restraint stiffness of the lipped flange has been derived. Using the expression, the characteristics of the rotational restraint stiffness of the lipped flange have been investigated. The results show that there is a linear coupling relationship between the applied forces and the rotational restraint stiffness of the lipped flange. Based on the explicit expression of the rotational restraint stiffness of the lipped flange, a simplified analytical formula has been derived which can determine the elastic distortional buckling critical stress of the CFLCCs subjected to axial compression. The simplified analytical formula developed in this study has been shown to be accurate through the comparisons with results from the distortional buckling analyses using the ANSYS finite element software. The developed analytical formula is easy to apply, and can be used directly in practical design and incorporated into future design codes and guidelines.

Exact and approximate solutions for free vibrations of continuous partial-interaction composite beams

  • Sun, Kai Q.;Zhang, Nan;Zhu, Qun X.;Liu, Xiao
    • Steel and Composite Structures
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    • 제44권4호
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    • pp.531-543
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    • 2022
  • An exact dynamic analytical method for free vibrations of continuous partial-interaction composite beams is proposed based on the Timoshenko beam theory. The main advantage of this method is that the independent shear deformations and rotary inertia of sub-beams are considered, which is more in line with the reality. Therefore, the accuracy of eigenfrequencies obtained by this method is significantly improved, especially for higher order modes, compared to the existing methods where the rotary angles of both sub-beams are assumed to be equal irrespective of the differences in the shear stiffness of each sub-beam. Furthermore, the solutions obtained by the proposed method are exact owing to no introduction of approximated displacement and force fields in the derivation. In addition, an exact analytical solution for the case of simply supported is obtained. Based on this, an approximate expression for the fundamental frequency of continuous partial-interaction composite beams is also proposed, which is useful for practical engineering applications. Finally, the practicability and effectiveness of the proposed method and the approximate expression are explored using numerical and experimental examples; The influence factors including the interfacial interaction, shear modulus ratio, span-to-depth ratio, and side-to-main span length ratio on the eigenfrequencies are presented and discussed in detail.

Sinusoidal Back-EMF of Vernier Permanent Magnet Machines

  • Li, Dawei;Qu, Ronghai
    • Journal of international Conference on Electrical Machines and Systems
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    • 제3권1호
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    • pp.40-47
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    • 2014
  • Sinusoidal back-EMF waveform of vernier Permanent Magnet (PM) machines is analyzed in this paper. An analytical expression of Electromotive Force (EMF) of electric machines including vernier machines is developed to analyze EMF harmonics, and the effect of vernier PM machine pole ratio, the ratio of number of rotor poles to stator poles, on the EMF waveform. Moreover, this paper represents several Finite Element Analysis (FEA) models to verify the analysis based on the proposed expression, and the effect of tooth width ratio, which is the ratio of tooth width to tooth pitch, on back-EMF of vernier PM machines, and optimal tooth width ratio is obtained and verified by FEA. Finally, this paper makes comparisons between EMF waveform of vernier PM machines and that of traditional PM machines from the point of view of analytical EMF expression.

A Closed-Form BER Expression for Decode-and-Forward Cooperative Communication Protocol

  • Kong, Hyung-Yun
    • Journal of electromagnetic engineering and science
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    • 제9권2호
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    • pp.66-70
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    • 2009
  • The decode-and-forward cooperative communication protocol allows single-antenna users in wireless environments to obtain the powerful benefits of multi-antenna systems without the need for physical arrays. Evaluating the performance of this protocol through simulations is time-consuming and therefore, a need exists for an analytical BER expression to serve as a reference. This paper proposed such an expression for coherently BPSK-modulated data.

Impact of High-Level Expression of Heterologous Protein on Lactococcus lactis Host

  • Kim, Mina;Jin, Yerin;An, Hyun-Joo;Kim, Jaehan
    • Journal of Microbiology and Biotechnology
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    • 제27권7호
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    • pp.1345-1358
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    • 2017
  • The impact of overproduction of a heterologous protein on the metabolic system of host Lactococcus lactis was investigated. The protein expression profiles of L. lactis IL1403 containing two near-identical plasmids that expressed high- and low-level of the green fluorescent protein (GFP) were examined via shotgun proteomics. Analysis of the two strains via high-throughput LC-MS/MS proteomics identified the expression of 294 proteins. The relative amount of each protein in the proteome of both strains was determined by label-free quantification using the spectral counting method. Although expression level of most proteins were similar, several significant alterations in metabolic network were identified in the high GFP-producing strain. These changes include alterations in the pyruvate fermentation pathway, oxidative pentose phosphate pathway, and de novo synthesis pathway for pyrimidine RNA. Expression of enzymes for the synthesis of dTDP-rhamnose and N-acetylglucosamine from glucose was suppressed in the high GFP strain. In addition, enzymes involved in the amino acid synthesis or interconversion pathway were downregulated. The most noticeable changes in the high GFP-producing strain were a 3.4-fold increase in the expression of stress response and chaperone proteins and increase of caseinolytic peptidase family proteins. Characterization of these host expression changes witnessed during overexpression of GFP was might suggested the metabolic requirements and networks that may limit protein expression, and will aid in the future development of lactococcal hosts to produce more heterologous protein.

식이보충제로 사용되는 히알루론산의 분석법에 대한 불확도 산정 (Measurement Uncertainty for Analytical Method of Hyaluronic Acid Used as a Dietary Supplement)

  • 박상욱;김형범;김광준;이원재
    • KSBB Journal
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    • 제32권1호
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    • pp.54-62
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    • 2017
  • This study aimed to estimate the measurement uncertainty related to determination of hyaluronic acid used as a dietary supplement by high-performance liquid chromatography. According to the guidelines of the Association of Official Analytical Chemists, the analytical processes for determination of hyaluronic acid were performed. And the measurement uncertainty obtained during the analytical processes were expressed in accordance with mathematical/ statistical guidances of GUM (Guide to the Expression of Uncertainty in Measurement) & EURACHEM (Focus for Analytical Chemistry in Europe) for the analytical operations. For the uncertainty in measurement produced based on this analytical method, the expanded uncertainty was calculated by using the relative standard uncertainty between analytical results and sources of uncertainty in measurement (sample weight, final volume, extraction volume, standard solution, matrix and instrument etc). In the results of 95% confidence interval, it was calculated that the uncertainty in measurement was $57.75{\pm}8.76{\mu}g/kg$ (k=2.0). Therefore, it showed that the measurement uncertainty obtained by this analytical method influences on 15.2% of the contents of hyaluronic acid as the analytical results.

No-backlash characteristics analysis of a cycloidal ball planetary transmission under axial pre-tightening

  • Yang, Ronggang;Wang, Naige;Xiang, Jiawei
    • Structural Engineering and Mechanics
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    • 제81권4호
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    • pp.481-492
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    • 2022
  • Cycloidal ball planetary transmission (CBPT) has many applications as precision reducer, such as precision machinery and automation drive systems etc. The traditional analytical model of CBPT cannot accurately describe the change of the normal force of meshing points, and thus cannot describe the precise transmission process of meshing pairs. In the paper, a method for deriving the normal force equation is put forward by using the non-linear relationship between force and deformation in elastic mechanics. The two-point contact analytical models of all the meshing pairs are established to obtain the micro-displacement analytical model of CBPT under axial pre-tightening. Then, the non-real-time two-point contact analytical models of all the meshing pairs are further constructed to obtain the normal force expression to determine the critical compression coefficients. Experimental investigations are performed to verify the analytical model using the critical compression coefficients.