Error Analysis of Three Degree-of-Freedom Changeable Parallel Measuring Mechanism

A three degree-of-freedom (DOF) planar changeable parallel mechanism is designed by means of control of different drive parameters. This mechanism possesses the characteristics of two kinds of parallel mechanism. Based on its topologic structure, a coordinate system for position analysis is set-up and the forward kinematic solutions are analyzed. It was found that the parallel mechanism is partially decoupled. The relationship between original errors and position-stance error of moving platform is built according to the complete differential-coefficient theory. Then we present a special example with theory values and errors to evaluate the error model, and numerical error solutions are gained. The investigations concentrating on mechanism errors and actuator errors show that the mechanism errors have more influences on the position-stance of the moving platform. It is demonstrated that improving manufacturing and assembly techniques can greatly reduce the moving platform error. The small change in position-stance error in different kinematic positions proves that the error-compensation of software can improve considerably the precision of parallel mechanism.

Scaling in Rate-Changeable Birth and Death Processes with Random Removals

We propose a monomer birth-death model with random removals, in which an aggregate of size k can produce a new monomer at a time-dependent rate I（t）k or lose one monomer at a rate J（t）k, and with a probability P（t） an aggregate of any size is randomly removed. We then anedytically investigate the kinetic evolution of the model by means of the rate equation. The results show that the scaling behavior of the aggregate size distribution is dependent crucially on the net birth rate I（t） - J（t） as well as the birth rate I（t）. The aggregate size distribution can approach a standard or modified scaling form in some cases, but it may take a scale-free form in other cases. Moreover, the species can survive finally only if either I（t） - J（t） ≥ P（t） or [J（t） ＋ P（t） - I（t）]t ≈ 0 at t ≥ 1; otherwise, it will become extinct.

Acute myocardial infarction associated with right bundle branch block and changeable trifascicular block: a case report

Rationale:Acute myocardial infarction in the presence of right bundle branch block.Patient concerns:A 70-year-old,male heavy smoker presented with angina and hypertension.Interventions:Electrocardiography,intravenous nitroglycerin infusion,intravenous streptokinase infusion.Diagnosis:Acute myocardial infarction in the presence of with changeable trifascicular heart block.Outcomes:Dramatic clinical improvement with electrocardiographic ST-segment (whether elevation or reciprocal ST-depression) resolution.Lessons:Acute myocardial infarction may be associated right bundle branch block.Accompanied trifascicular heart block had pre-streptokinase left anterior fascicular block with left axis deviation and post-streptokinase left posterior fascicular block with right axis deviation.

Secure hash function based on chaotic tent map with changeable parameter

A new algorithm for a novel hash function, based on chaotic tent map with changeable parameter, is proposed and analyzed. The one dimensional and piecewise tent map with changeable parameters decided by the position index of blocked messages is chosen, and blocked massages translated into ASCII code values are employed as the iteration time of the chaotic tent map. The final 128-bit hash value is generated by logical XOR operation on intermediate hash values. Theoretical analysis and computer simulation indicate that the proposed algorithm can satisfy the performance requirements of hash function.

Surface rupture zone of the 1303 Hongtong M=8 earthquake, Shanxi Province

Based on the latest displacement of Huoshan piedmont fault, Mianshan west-side fault and Taigu fault obtained from the beginning of 1990s up to the present, the characteristics of distribution and displacement of surface rup-ture zone of the 1303 Hongtong M = 8 earthquake, Shanxi Province are synthesized and discussed in the paper. If Taigu fault, Mianshan west-side fault and Huoshan piedmont fault were contemporarily active during the 1303 Hongtong M = 8 earthquake, the surface rupture zone would be 160 km long and could be divided into 3 segments, that is, the 50-km-long Huoshan piedmont fault segment, 35-km-long Mianshan west-side fault segment and 70-km-long Taigu fault segment, respectively. Among them, there exist 4 km and 8 km step regions. The surface rupture zone exhibits right-lateral features. The displacements of northern and central segments are respectively 6~7 m and the southern segment has the maximum displacement of 10 m. The single basin-boundary fault of Shanxi fault-depression system usually corresponds to M 7 earthquake, while this great earthquake (M = 8) broke through the obstacle between two basins. It shows that the surface rupture scale of great earthquake is changeable.

The Nonlinear Analysis of Spherical Caps under Centrally Distributed Pressures

in this paper, the nonlinear response of spherical caps under centrally distributed pressures isstudied by the hybrid changeable basis Galerkin techmique. The influence of the boundary conditions and thesize of loaded radius on the nonlinear response of the caps is analyzed. The effectiveness of teclmique isdemonstrated by the numerical examples.

Geographical classification of Nanfeng mandarin by near infrared spectroscopy coupled with chemometrics methods

Near infrared spectroscopy(NIRS),coupled with principal component analysis and wavelength selection techniques,has been sed to develop a robust and reliable reduced-spectrum classifi-cation model for determining the geographical origins of Nanfeng mandarins.The application of the changeable size moving window principal component analysis(CSMWPCA)provided a notably improved lassification model,with correct classification rates of 92.00%,100.00%,90.00%,100.00%,100.00%,100.00%and 100.00%for Fujian,Guangxi,Hunan,Baishe,Baofeng,Qiawan,Sanxi samples,respectively,as well as,a total dassification rate of 97.52%in the wavelength range from 1007 to 1296 nm.To test and apply the proposed method,the procedure was applied to the analysis of 59 samples in an independent test set.Good identification results(correct rate of 96.61%)were also received.The improvement achieved by the application of CSMWPCA method was particularly remarkable when taking the low complexities of the final model(290 variables)into account.The results of the study showed the great potential of NIRS as a fast,nondestructive and environmentally acceptable method for the rapid and reliable determination for geographical classifcation of Nanfeng mandarins.

A Modified Cellular Automaton Model for Traffic Flow

A modified cellular automaton model for traffic flow was proposed. A novel concept about the changeable security gap was introduced and a parameter related to the variable security gap was determined. The fundamental diagram obtained by simulation shows that the maximum flow more approaches to the observed data than that of the NaSch model, indicating that the presented model is more reasonable and realistic.

Some Methods That Merit Attention

Undoubtedly, the international environment that China faces remains changeable, thus arousing some problems with which people are not familiar or great changes have taken place in the background and condition. In this sense, it is absolutely an uneasy job to make a deep analysis of today’s international environment. In particular.

Nature and Kinetic Architecture： The Development of a New Type of Transformable Structure for Temporary Applications

The contemplation of contemporary architectural designs shows an increasing demand for the development of more adaptable, flexible and transformable structures. This type of structures can adapt with different environmental conditions and meet different functions. This can help in reducing environmental waste and pollution associated with many buildings and above all can save on cost and time. Natural systems have inspired human being, since they began to build and design. Architects and designers have utilized nature as one of the main resources of information for the creation of innovative architectural spaces. One of the unique features of natural structures is the way that their components open and close in order to respond to a particular requirement or the environmental changes. This aspect has inspired many designers for the development of transformable architectural structures that can change their shape and geometry to be able to adapt with specific conditions. To make a way toward the design of transformable structure for temporary applications, the authors have developed a new type of adaptable structures according to natural forms. The proposed design applies the transformation principles that exist in potato＇s flower and the movement mechanisms used in a spider＇s leg. The design is able to fit to different topographies and have a potential to be folded to a very compact state in a very short period of time. The detailed design and the different configurations of the system applications will be presented in this paper. The result of the study shows that using modular triangular plates can create a changeable module that is not only able to respond to different functions and environmental changes but it is also able to shape different configuration to be able to respond to different user＇s ambitions. The compactability of this structure into 1/3 of its base dimensions; makes its transportation fast and with minimum costs. These capabilities make this structure suitable for temporary buildings such as exhibitions, temporary settlements or hospital in damaged areas.

Seasonal Distribution of Manganese in the Soil-Water-Plant in the Zone of Burshtyn Thermal Power Station

This study deals with the impact of Burshtyn thermal power station on the amount of manganese in soil, water and celandine tissue. The research of manganese amount and form in the system： water-plant is of great importance due to active influence of thermal power station on the chemical structure of the polluted area. The changes in the amount and form of manganese in soil, water and plant are interrelated and depend on the season, the distance from the polluter and morph-functional plant structure, the cleaning system possibilities of the industrial enterprise and some meteorological factors.

“自相矛盾”的短语一瞥

所谓“自相矛盾”的短语,指的是英语中由两个在概念上、意义上相对或相反的词通过关联词连结而成的一种惯用短语。这类短语在我们的平时阅读中经常碰到。本文拟将简单地分析一下这类短语的构成方式及语法功能。

英国风情点滴

1.在英国,非机动车辆和行人靠左行,而不是靠右行(象我国这样),走在街上您可常见到这样的交通牌“KEEP TO THE LEFT.”2.大部分英国人可接受免费高等教育,但学生必须在假期中赚些零花钱(pocket money or spending money)。3.英国法律规定:儿童的学龄是从5岁到16岁,5岁进小学,11岁进中学,18岁的青年就到婚龄了,尽管英国的成年习惯法为21岁,难怪有人说:“

Gender Differences in the Cognition About the Changeability of Body

This study examined gender differences in the cognition of the changeability of different parts of the body. The body was divided into six parts： ＂eyes＂, ＂hair＂, ＂upper body＂, ＂lower body＂, ＂facial features＂, and ＂skin＂, and male and female cognition about the changeability of each body part was compared. The participants were 205 undergraduate students （145 female students and 60 male studentsl） enrolled in a university in Japan. The female and male students showed a similarity in their cognition of＂hair＂ as easily changeable and ＂facial features＂ as difficult to change. In addition, there was a difference between the male and female students in the cognition of the changeability of the ＂eyes＂, with the females perceiving a high level of changeability and men, a low changeability. This result suggests that female students believe in the effectiveness of makeup for covering cosmetic flaws of the eye.

外教新词堂

炎热的七月到了,暑假还会远吗?!你是否还在为该如何度过暑假而blow hot and cold?Anyway,跟阳光玩游戏的时候不要忘记防晒、防暑哦!1.blaze down(on sb.or sth.)(来自太阳或强光的)照射[for the sun or other hot light]to burn from above onto sb.or sth.e.g.The stage lights blazed down on the set while the actors rehearsed.

Time-resolved multiple imaging by detecting photons with changeable wavelengths

Transporting information is one of the important functions of photons and is also the essential duty of information science. Here, we realize multiple imaging by detecting photons with changeable wavelengths based on time-resolved correlation measurements. In our system, information from multiple objects can be transported. During this process, the wavelength of the photons illuminating the objects is different from the wavelength of the photons detected by the detectors. More importantly, the wavelength of the photons that are utilized to record images can also be changed to match the sensitive range of the used detectors. In our experiment, images of the objects are reconstructed clearly by detecting the photons at wavelengths of 650, 810, and 1064 nm, respectively. These properties should have potential applications in information science.

The effect of finite duration inputs on the dynamics of a system： Proposing a new approach for cancer treatment

In this paper, a principal question regarding the effect of inputs on the characteristics of dynamic systems is discussed. Whether an input implemented only for a limited duration, can change the characteristics of a dynamic system such that the behavior of the free system, after eliminating the input, differs from that before acting the input？ In this paper, it is shown that a limited time acted input is not able to change the dynamical properties of a system after its elimination. Regarding the proposed approach, a novel finite duration treatment method is developed for a tumor-immune system. The vaccine therapy is used to change the parameters of the system and the chemotherapy is applied for pushing the system to the domain of attraction of the healthy state. For optimal chemotherapy, an optimal control is used based on state-dependent Riccati equation （SDRE）. It is shown that, in spite of eliminating the treatment （therapeutic inputs）, the system approaches to healthy state conditions. The present analysis suggests that a proper treatment method must change the dynamics of the cancer instead of only reducing the population of cancer cells.

The Queuing Model of M/M/S/K ＋ M Based on the Impatience and Changeable Service Rate

The work flow of call center is a typical stochastic service system. This article exploites service rate, which is the most controllable artificial factor of call center, and integrates the abandoning rate of impatient customers, models a new-style call center＇s queuing model - the queuing model of M/M/S/K ＋ M based on the impatience and changeable service rate. Then, making use of the traffic forecast result coming from the time series, it models to figure out the numbers of agents per hour, and complete the agents＇ office-hour arrangements in the restriction of some system indexes. Finally, it optimizes the design method by the contrast and analysis of the changeable service rate model and the traditional regular service rate model.

Ramp Scheme Based on CRT for Polynomial Ring over Finite Field

Chinese Reminder Theorem(CRT)for integers has been widely used to construct secret sharing schemes for different scenarios,but these schemes have lower information rates than that of Lagrange interpolation-based schemes.In ASIACRYPT 2018,Ning,et al.constructed a perfect(r,n)-threshold scheme based on CRT for polynomial ring over finite field,and the corresponding information rate is one which is the greatest case for a(r,n)-threshold scheme.However,for many practical purposes,the information rate of Ning,et al.scheme is low and perfect security is too much security.In this work,the authors generalize the Ning,et al.(r,n)-threshold scheme to a(t,r,n)-ramp scheme based on CRT for polynomial ring over finite field,which attains the greatest information rate(r−t)for a(t,r,n)-ramp scheme.Moreover,for any given 2≤r_(1)<r_(2)≤n,the ramp scheme can be used to construct a(r_(1),n)-threshold scheme that is threshold changeable to(r′,n)-threshold scheme for all r′∈{r_(1)+1,r_(1)+2,···,r_(2)}.The threshold changeable secret sharing(TCSS)scheme has a greater information rate than other existing TCSS schemes of this type.

可变系统结构建模

可变系统结构建模肖人彬，罗云峰，王雪，费奇（武汉华中理工大学，武汉４３００７４）ＳｔｒｕｃｔｕｒａｌＭｏｄｅｌｉｎｇｆｏｒＣｈａｎｇｅａｂｌｅＳｙｓｔｅｍｓＸｉａｏＲｅｎｂｉｎＬｕｏＹｕｎｆｅｎｇＷａｎｇＸｕｅＦｅｉＱｉ（ＨｕａｚｈｏｎｇＵｎｉｖｅｒ...