By use of the property of the momentum equation describing the hydraulic jump in rectangular channels, a generalized solution of the sequent depth ratio was given. On the basis of the generalized solution the explicit...By use of the property of the momentum equation describing the hydraulic jump in rectangular channels, a generalized solution of the sequent depth ratio was given. On the basis of the generalized solution the explicit solutions of the sequent depth ratio were obtained for the hydraulic jump in gradual enlargements, the corresponding relative energy losses were also presented, and a method to determine the location of hydraulic jump in gradual enlargements was proposed.展开更多
In this study,the main properties of the hydraulic jump in an asymmetric trapezoidal flume are analyzed experimentally,including the so-called sequent depths,characteristic lengths,and efficiency.In particular,an asym...In this study,the main properties of the hydraulic jump in an asymmetric trapezoidal flume are analyzed experimentally,including the so-called sequent depths,characteristic lengths,and efficiency.In particular,an asymmetric trapezoidal flume with a length of 7 m and a width of 0.304 m is considered,with the bottom of the flume transversely inclined at an angle of m=0.296 and vertical lateral sides.The corresponding inflow Froude number is allowed to range in the interval(1.40<F1<6.11).The properties of this jump are compared to those of hydraulic jumps in channels with other types of cross-sections.A relationship for calculating hydraulic jump efficiency is proposed for the considered flume.For F1>5,the hydraulic jump is found to be more effective than that occurring in triangular and symmetric trapezoidal channels.Also,when■mes>8 and■>5,the hydraulic jump in the asymmetrical trapezoidal channel downstream of a parallelogram sluice gate is completely formed as opposed to the situation where a triangular sluice is considered.展开更多
The draft ratios for sizing the reservoirs can vary within a wide range (40% - 90% of the mean annual flow, MAF), depending upon the demands for water by various users, and environmental and ecological considerations....The draft ratios for sizing the reservoirs can vary within a wide range (40% - 90% of the mean annual flow, MAF), depending upon the demands for water by various users, and environmental and ecological considerations. The reservoir volumes based on the drought magnitude (DM) method were assessed at aforesaid draft ratios using monthly-standardized hydrological index (SHI) sequences of 10 Canadian rivers located in the Canadian prairies and northwestern Ontario. These rivers are typified by a high level of persistence lag-1 autocorrelation, ρ<sub>1m</sub> ≥ 0.50 and up to 0.94) and coefficient of variation (cv<sub>o</sub>) in the range of 0.42 to 1.48. The moving average (MA) smoothing of monthly SHI sequences formed the basis of the DM method for estimating reservoir volumes. The truncation or cutoff level in the SHI sequences was found as SHI<sub>x</sub> [=(α - 1)μ<sub>o</sub>/σ<sub>o</sub>], [(α - 1)μ<sub>o</sub>/σ<sub>max</sub>], or [(α - 1)μ<sub>o</sub>/σ<sub>av</sub>], where α (=0.40 to 0.90) is the draft ratio i.e. proportion of the MAF, μ<sub>o</sub> and σ<sub>o</sub> are the overall mean and standard deviation of the monthly flows, σ<sub>max</sub> is the maximum value of standard deviations and σ<sub>av</sub> the average of 12 monthly values. The failure probability levels (PF) were fixed at 5%, 2.5% and 0% (corresponding reliability of 95%, 97.5% and 100%). The study revealed that the coefficient of variation is the most important parameter that influences the reservoir size while the role of lag-1 autocorrelation (ρ<sub>1m</sub>) appears more pronounced at high draft ratios, α such as 0.90, 0.80 and 0.70 in increasing the reservoir size. The DM based method can be regarded as an alternative to Behavior analysis for sizing reservoirs at the desired probability of failure or reliability level.展开更多
The traditional sequent peak algorithm (SPA) was used to assess the reservoir volume (<em>V<sub>R</sub></em>) for comparison with deficit volume, <em>D<sub>T</sub></em>,...The traditional sequent peak algorithm (SPA) was used to assess the reservoir volume (<em>V<sub>R</sub></em>) for comparison with deficit volume, <em>D<sub>T</sub></em>, (subscript T representing the return period) obtained from the drought magnitude (DM) based method with draft level set at the mean annual flow on 15 rivers across Canada. At the annual scale, the SPA based estimates are larger, on an average of nearly 70%, compared to the DM based estimates. To ramp up the DM based estimates to be in parity with SPA based values, the analysis was conducted through the counting and the analytical procedures involving only the annual SHI (standardized hydrological index, <em>i.e.</em> standardized values of annual flows) sequences. It was found that MA2 or MA3 (moving average of 2 or 3 consecutive values) of SHI sequences was required to match the counted values of <em>D<sub>T</sub></em> to <em>V<sub>R</sub></em>. Further, the inclusion of mean, as well as the variance of the drought intensity in the analytical procedure, with the aforesaid smoothing led <em>D<sub>T</sub></em> comparable to <em>V<sub>R</sub></em>. The distinctive point in the DM based method is that no assumption is necessary such as the reservoir being full at the beginning of the analysis—as it is the case with the SPA.展开更多
The temporal logic given by Manna and Pnueli for concurrent program verification has been investigated, whose time structure is isomorphic to natural number set and the operators are □, ◇, ○, U. By analyzing the ma...The temporal logic given by Manna and Pnueli for concurrent program verification has been investigated, whose time structure is isomorphic to natural number set and the operators are □, ◇, ○, U. By analyzing the main methods of the temporal theorem proving, their disadvantages have been revealed, for which a sequent system of propositional temporal logic (PTL) has been established and its soundness and completeness has been proved.展开更多
The notion of context provides flexibility and adaptation to cloud computing services. Location, time identity and activity of users are examples of primary context types. The motivation of this paper is to formalize ...The notion of context provides flexibility and adaptation to cloud computing services. Location, time identity and activity of users are examples of primary context types. The motivation of this paper is to formalize reasoning about context information in cloud computing environments. To formalize such context-aware reasoning, the logic LCM of context-mixture is introduced based on a Gentzen-type sequent calculus for an extended resource-sensitive logic. LCM has a specific inference rule called the context-mixture rule, which can naturally represent a mechanism for merging formulas with context information. Moreover, LCM has a specific modal operator called the sequence modal operator, which can suitably represent context information. The cut-elimination and embedding theorems for LCM are proved, and a fragment of LCM is shown to be decidable. These theoretical results are intended to provide a logical justification of context-aware cloud computing service models such as a flowable service model.展开更多
Some computational issues on abduction are discussed in a framework of the first order sequent calculus. Starting from revising the meaning of 'good' abduction, a new criterion of abduction called intuitive-mi...Some computational issues on abduction are discussed in a framework of the first order sequent calculus. Starting from revising the meaning of 'good' abduction, a new criterion of abduction called intuitive-minimal abduction (IMA) is introduced.An IMA is an abductive formula equivalent to the minimal abductive formula under the theory part of a sequent and literally as simple as possible. Abduction algorithms are presented on the basis of a complete natural reduction system. An abductive formula, obtained by the algorithms presented in this papert is an IMA if the reduction tree, from which the abduction is performed, is fully expanded. Instead of using Skolem functions, a term-ordering is used to indicate dependency between terms.展开更多
Retention of urine after parturition isfrequently encountered in obstetricepractice.Many methods of treatment can beadopted with certain effects.of these,urethral catheterization is often used.How-ever,most patients a...Retention of urine after parturition isfrequently encountered in obstetricepractice.Many methods of treatment can beadopted with certain effects.of these,urethral catheterization is often used.How-ever,most patients are unwilling to receivethis manoeuvre because it may induce sub-sequent urethritis and urocystitis,and re-peated catheterization is required to bringforth any effect.The authors,nevertheless,展开更多
A sequent is a pair (Γ, Δ), which is true under an assignment if either some formula in Γ is false, or some formula in Δ is true. In L_(3)-valued propositional logic, a multisequent is a triple Δ∣Θ∣Γ, which i...A sequent is a pair (Γ, Δ), which is true under an assignment if either some formula in Γ is false, or some formula in Δ is true. In L_(3)-valued propositional logic, a multisequent is a triple Δ∣Θ∣Γ, which is true under an assignment if either some formula in Δ has truth-value t, or some formula in Θ has truth-value m, or some formula in Γ has truth-value f. There is a sound, complete and monotonic Gentzen deduction system G for sequents. Dually, there is a sound, complete and nonmonotonic Gentzen deduction system G′ for co-sequents Δ: Θ: Γ. By taking different quantifiers some or every, there are 8 kinds of definitions of validity of multisequent Δ∣Θ∣Γ and 8 kinds of definitions of validity of co-multisequent Δ: Θ: Γ, and correspondingly there are 8 sound and complete Gentzen deduction systems for sequents and 8 sound and complete Gentzen deduction systems for co-sequents. Correspondingly their monotonicity is discussed.展开更多
Two purple rice mutants OPL and PL184 were se-lected from normal green rice lines Ketan Nangkaand W6184 in 1988 and 1990 respectively.No segre-gation was found in two sequent generations.Whenthese two purple rice wer... Two purple rice mutants OPL and PL184 were se-lected from normal green rice lines Ketan Nangkaand W6184 in 1988 and 1990 respectively.No segre-gation was found in two sequent generations.Whenthese two purple rice were crossed with each other,展开更多
二、套话连篇美国总统克林顿的名字除了派生出 Clintonian 这个词以外,还生成了Clintonspeak(克林顿式的说话方式)这个新词,用英语来解释就是“the typi-cal language,jargon,or vocabulary of Bill Clinton”,这个词早在克林坝竞选总...二、套话连篇美国总统克林顿的名字除了派生出 Clintonian 这个词以外,还生成了Clintonspeak(克林顿式的说话方式)这个新词,用英语来解释就是“the typi-cal language,jargon,or vocabulary of Bill Clinton”,这个词早在克林坝竞选总统的时候就出现了。例如,His evasive response concerning his use of marijua-na at Oxford—“I have never broken the laws of my country”—and his sub-sequent claim—“I never inhaled”—seemed the quitessence of Clinton-展开更多
On the basis of the previous studies of the layered crustal model in the Yutian area,combined with the field GPS continuous observation data,we roughly estimate the viscous coefficient of each layer. With the viscoela...On the basis of the previous studies of the layered crustal model in the Yutian area,combined with the field GPS continuous observation data,we roughly estimate the viscous coefficient of each layer. With the viscoelastic horizontal layer model,we calculate the viscoelastic co-seismic Coulomb stress change caused by the Yutian M_S7. 3 earthquakes 2008 and 2014 respectively. Based on the Coulomb stress change,using the calculation method of "direct "aftershock frequency,we come up with the theoretical earthquake frequency directly related to the mainshock and the co-seismic Coulomb stress change in the study area. Then we put forward a method,based on the comparison of theoretical and actual earthquake frequency or the comparison between theoretical and practical earthquake frequency-distance decay curve fitting residuals,to estimate the magnitude of a maximum sequent earthquake,directly related to the mainshock co-seismic Coulomb stress change. Results calculated by different methods show that the maximum follow-up earthquake magnitude caused by the coseismic Coulomb stress change lies from M_S7. 2 to M_S7. 5 following Yutian M_S7. 3 earthquake in 2008; but that of the 2014 Yutian M_S7. 3 earthquake is M_S6. 3. The former is very close to the Yutian M_S7. 3 earthquake in 2014.Because of the same magnitude,relatively close spatial distance,short time interval,the same region of the external force,the strong correlation between two seismic tectonic and a clear stress interaction,we thus consider that the two Yutian M_S7. 3 earthquakes in 2008 and 2014 constitute a pair of generalized double shock type earthquake. This is consistent with the sequence type characteristic of past "double shock"earthquakes in the region. In this paper,the influence of the magnitude lower limit and the b-value in the relationship of G-R on the results is discussed. As a result,when the viscoelastic coseismic Coulomb stress variation is determined,the lower limit of magnitude has little effect on the maximum sequent earthquake magnitude 展开更多
The proof system, based on resolution method, has become quite popular in automatic theorem proving, because this method is simple to implement. At present many kinds of extensions for resolution method are known： Re...The proof system, based on resolution method, has become quite popular in automatic theorem proving, because this method is simple to implement. At present many kinds of extensions for resolution method are known： Resolution with restricted number of variables in disjuncts, resolution over Linear Equations, Cutting planes, etc. For Classical, Intuitionistic and Minimal （Johansson＇s） propositional logics, the authors introduce the family of resolution systems with full substitution rule （SRC, SRI and SRM） and with e-restricted substitution rule （SeRC, SeRf and SeRM）, where the number of substituted formula connectives is bounded by . The authors show that for each of mentioned logic the SR-type system （in tree form） is polynomially equivalent to Frege systems by size, but for every ~＇ 〉 0, Se＋lR-type has exponential speed-up over the SeR-type （in tree form）.展开更多
Traditional first-order logic has four definitions for quantifiers,which are defined by universal and existential quantifiers.In L_(3)-valued(three-valued)first-order logic,there are eight kinds of definitions for qua...Traditional first-order logic has four definitions for quantifiers,which are defined by universal and existential quantifiers.In L_(3)-valued(three-valued)first-order logic,there are eight kinds of definitions for quantifiers;and corresponding Gentzen deduction systems will be given and their soundness and completeness theorems will be proved.展开更多
文摘By use of the property of the momentum equation describing the hydraulic jump in rectangular channels, a generalized solution of the sequent depth ratio was given. On the basis of the generalized solution the explicit solutions of the sequent depth ratio were obtained for the hydraulic jump in gradual enlargements, the corresponding relative energy losses were also presented, and a method to determine the location of hydraulic jump in gradual enlargements was proposed.
文摘In this study,the main properties of the hydraulic jump in an asymmetric trapezoidal flume are analyzed experimentally,including the so-called sequent depths,characteristic lengths,and efficiency.In particular,an asymmetric trapezoidal flume with a length of 7 m and a width of 0.304 m is considered,with the bottom of the flume transversely inclined at an angle of m=0.296 and vertical lateral sides.The corresponding inflow Froude number is allowed to range in the interval(1.40<F1<6.11).The properties of this jump are compared to those of hydraulic jumps in channels with other types of cross-sections.A relationship for calculating hydraulic jump efficiency is proposed for the considered flume.For F1>5,the hydraulic jump is found to be more effective than that occurring in triangular and symmetric trapezoidal channels.Also,when■mes>8 and■>5,the hydraulic jump in the asymmetrical trapezoidal channel downstream of a parallelogram sluice gate is completely formed as opposed to the situation where a triangular sluice is considered.
文摘The draft ratios for sizing the reservoirs can vary within a wide range (40% - 90% of the mean annual flow, MAF), depending upon the demands for water by various users, and environmental and ecological considerations. The reservoir volumes based on the drought magnitude (DM) method were assessed at aforesaid draft ratios using monthly-standardized hydrological index (SHI) sequences of 10 Canadian rivers located in the Canadian prairies and northwestern Ontario. These rivers are typified by a high level of persistence lag-1 autocorrelation, ρ<sub>1m</sub> ≥ 0.50 and up to 0.94) and coefficient of variation (cv<sub>o</sub>) in the range of 0.42 to 1.48. The moving average (MA) smoothing of monthly SHI sequences formed the basis of the DM method for estimating reservoir volumes. The truncation or cutoff level in the SHI sequences was found as SHI<sub>x</sub> [=(α - 1)μ<sub>o</sub>/σ<sub>o</sub>], [(α - 1)μ<sub>o</sub>/σ<sub>max</sub>], or [(α - 1)μ<sub>o</sub>/σ<sub>av</sub>], where α (=0.40 to 0.90) is the draft ratio i.e. proportion of the MAF, μ<sub>o</sub> and σ<sub>o</sub> are the overall mean and standard deviation of the monthly flows, σ<sub>max</sub> is the maximum value of standard deviations and σ<sub>av</sub> the average of 12 monthly values. The failure probability levels (PF) were fixed at 5%, 2.5% and 0% (corresponding reliability of 95%, 97.5% and 100%). The study revealed that the coefficient of variation is the most important parameter that influences the reservoir size while the role of lag-1 autocorrelation (ρ<sub>1m</sub>) appears more pronounced at high draft ratios, α such as 0.90, 0.80 and 0.70 in increasing the reservoir size. The DM based method can be regarded as an alternative to Behavior analysis for sizing reservoirs at the desired probability of failure or reliability level.
文摘The traditional sequent peak algorithm (SPA) was used to assess the reservoir volume (<em>V<sub>R</sub></em>) for comparison with deficit volume, <em>D<sub>T</sub></em>, (subscript T representing the return period) obtained from the drought magnitude (DM) based method with draft level set at the mean annual flow on 15 rivers across Canada. At the annual scale, the SPA based estimates are larger, on an average of nearly 70%, compared to the DM based estimates. To ramp up the DM based estimates to be in parity with SPA based values, the analysis was conducted through the counting and the analytical procedures involving only the annual SHI (standardized hydrological index, <em>i.e.</em> standardized values of annual flows) sequences. It was found that MA2 or MA3 (moving average of 2 or 3 consecutive values) of SHI sequences was required to match the counted values of <em>D<sub>T</sub></em> to <em>V<sub>R</sub></em>. Further, the inclusion of mean, as well as the variance of the drought intensity in the analytical procedure, with the aforesaid smoothing led <em>D<sub>T</sub></em> comparable to <em>V<sub>R</sub></em>. The distinctive point in the DM based method is that no assumption is necessary such as the reservoir being full at the beginning of the analysis—as it is the case with the SPA.
基金Project supported in part by "863" High Tech Projects and by the National Natural Science Foundation of China.
文摘The temporal logic given by Manna and Pnueli for concurrent program verification has been investigated, whose time structure is isomorphic to natural number set and the operators are □, ◇, ○, U. By analyzing the main methods of the temporal theorem proving, their disadvantages have been revealed, for which a sequent system of propositional temporal logic (PTL) has been established and its soundness and completeness has been proved.
文摘The notion of context provides flexibility and adaptation to cloud computing services. Location, time identity and activity of users are examples of primary context types. The motivation of this paper is to formalize reasoning about context information in cloud computing environments. To formalize such context-aware reasoning, the logic LCM of context-mixture is introduced based on a Gentzen-type sequent calculus for an extended resource-sensitive logic. LCM has a specific inference rule called the context-mixture rule, which can naturally represent a mechanism for merging formulas with context information. Moreover, LCM has a specific modal operator called the sequence modal operator, which can suitably represent context information. The cut-elimination and embedding theorems for LCM are proved, and a fragment of LCM is shown to be decidable. These theoretical results are intended to provide a logical justification of context-aware cloud computing service models such as a flowable service model.
文摘Some computational issues on abduction are discussed in a framework of the first order sequent calculus. Starting from revising the meaning of 'good' abduction, a new criterion of abduction called intuitive-minimal abduction (IMA) is introduced.An IMA is an abductive formula equivalent to the minimal abductive formula under the theory part of a sequent and literally as simple as possible. Abduction algorithms are presented on the basis of a complete natural reduction system. An abductive formula, obtained by the algorithms presented in this papert is an IMA if the reduction tree, from which the abduction is performed, is fully expanded. Instead of using Skolem functions, a term-ordering is used to indicate dependency between terms.
文摘Retention of urine after parturition isfrequently encountered in obstetricepractice.Many methods of treatment can beadopted with certain effects.of these,urethral catheterization is often used.How-ever,most patients are unwilling to receivethis manoeuvre because it may induce sub-sequent urethritis and urocystitis,and re-peated catheterization is required to bringforth any effect.The authors,nevertheless,
基金supported by the Open Fund of the State KeyLaboratory of Sofware Development Environment(SKLSDE-2010KF-06)Beijing University of Aeronautics and Astronautics,and by the National Basic Research Program of China(973 Program)(2005CB321901).
文摘A sequent is a pair (Γ, Δ), which is true under an assignment if either some formula in Γ is false, or some formula in Δ is true. In L_(3)-valued propositional logic, a multisequent is a triple Δ∣Θ∣Γ, which is true under an assignment if either some formula in Δ has truth-value t, or some formula in Θ has truth-value m, or some formula in Γ has truth-value f. There is a sound, complete and monotonic Gentzen deduction system G for sequents. Dually, there is a sound, complete and nonmonotonic Gentzen deduction system G′ for co-sequents Δ: Θ: Γ. By taking different quantifiers some or every, there are 8 kinds of definitions of validity of multisequent Δ∣Θ∣Γ and 8 kinds of definitions of validity of co-multisequent Δ: Θ: Γ, and correspondingly there are 8 sound and complete Gentzen deduction systems for sequents and 8 sound and complete Gentzen deduction systems for co-sequents. Correspondingly their monotonicity is discussed.
文摘 Two purple rice mutants OPL and PL184 were se-lected from normal green rice lines Ketan Nangkaand W6184 in 1988 and 1990 respectively.No segre-gation was found in two sequent generations.Whenthese two purple rice were crossed with each other,
文摘二、套话连篇美国总统克林顿的名字除了派生出 Clintonian 这个词以外,还生成了Clintonspeak(克林顿式的说话方式)这个新词,用英语来解释就是“the typi-cal language,jargon,or vocabulary of Bill Clinton”,这个词早在克林坝竞选总统的时候就出现了。例如,His evasive response concerning his use of marijua-na at Oxford—“I have never broken the laws of my country”—and his sub-sequent claim—“I never inhaled”—seemed the quitessence of Clinton-
基金sponsored by the Scientific Research Fund of the Department of Earthquake Monitoring and Prediction,CEA
文摘On the basis of the previous studies of the layered crustal model in the Yutian area,combined with the field GPS continuous observation data,we roughly estimate the viscous coefficient of each layer. With the viscoelastic horizontal layer model,we calculate the viscoelastic co-seismic Coulomb stress change caused by the Yutian M_S7. 3 earthquakes 2008 and 2014 respectively. Based on the Coulomb stress change,using the calculation method of "direct "aftershock frequency,we come up with the theoretical earthquake frequency directly related to the mainshock and the co-seismic Coulomb stress change in the study area. Then we put forward a method,based on the comparison of theoretical and actual earthquake frequency or the comparison between theoretical and practical earthquake frequency-distance decay curve fitting residuals,to estimate the magnitude of a maximum sequent earthquake,directly related to the mainshock co-seismic Coulomb stress change. Results calculated by different methods show that the maximum follow-up earthquake magnitude caused by the coseismic Coulomb stress change lies from M_S7. 2 to M_S7. 5 following Yutian M_S7. 3 earthquake in 2008; but that of the 2014 Yutian M_S7. 3 earthquake is M_S6. 3. The former is very close to the Yutian M_S7. 3 earthquake in 2014.Because of the same magnitude,relatively close spatial distance,short time interval,the same region of the external force,the strong correlation between two seismic tectonic and a clear stress interaction,we thus consider that the two Yutian M_S7. 3 earthquakes in 2008 and 2014 constitute a pair of generalized double shock type earthquake. This is consistent with the sequence type characteristic of past "double shock"earthquakes in the region. In this paper,the influence of the magnitude lower limit and the b-value in the relationship of G-R on the results is discussed. As a result,when the viscoelastic coseismic Coulomb stress variation is determined,the lower limit of magnitude has little effect on the maximum sequent earthquake magnitude
文摘The proof system, based on resolution method, has become quite popular in automatic theorem proving, because this method is simple to implement. At present many kinds of extensions for resolution method are known： Resolution with restricted number of variables in disjuncts, resolution over Linear Equations, Cutting planes, etc. For Classical, Intuitionistic and Minimal （Johansson＇s） propositional logics, the authors introduce the family of resolution systems with full substitution rule （SRC, SRI and SRM） and with e-restricted substitution rule （SeRC, SeRf and SeRM）, where the number of substituted formula connectives is bounded by . The authors show that for each of mentioned logic the SR-type system （in tree form） is polynomially equivalent to Frege systems by size, but for every ~＇ 〉 0, Se＋lR-type has exponential speed-up over the SeR-type （in tree form）.
基金the Open Fund of the State Key Laboratory of Software Development Environment(SKLSDE-2010KF-06)Beijing University of Aeronautics and Astronautics,and by the National Basic Research Program of China(973 Program)(2005CB321901).
文摘Traditional first-order logic has four definitions for quantifiers,which are defined by universal and existential quantifiers.In L_(3)-valued(three-valued)first-order logic,there are eight kinds of definitions for quantifiers;and corresponding Gentzen deduction systems will be given and their soundness and completeness theorems will be proved.
