Imbalance Phenomenon Research Articles

Pseudogap phenomenon and effects of population imbalance in the normal state of a unitary Fermi gas

We investigate strong-coupling corrections to single-particle excitations in the normal state of a spin-polarized unitary Fermi gas. Within the framework of an extended T-matrix approximation, we calculate the single-particle density of states, as well as the single-particle spectral weight, to show that the so-called pseudogap phenomenon gradually disappears with increasing the magnitude of an effective magnetic field. In the highly spin-polarized regime, the calculated spin-polarization rate as a function of the effective magnetic field agrees well with the recent experiment on a 6Li Fermi gas. Although this experiment has been considered to be incompatible with the existence of the pseudogap in an unpolarized Fermi gas, our result clarifies that the observed spin-polarization rate in the highly spin-polarized regime and the pseudogap in the unpolarized limit can be explained in a consistent manner, when one correctly includes effects of population imbalance on single-particle excitations. Since it is a crucial issue to clarify whether the pseudogap exists or not in the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover regime of an ultracold Fermi gas, our results would be useful for the understanding of this strongly interacting fermion system.

An Approach to Achieving K-partition for Preserving Privacy by Using Multi-constraint Anonymous Parameter Based on Rough Sets

We propose an approach to achieving different K -partition for preserving privacy by using the multi-constraint anonymous parameter design method based on the attribute significance of rough set, in order to reduce the imbalance phenomenon between the privacy protection and data availability caused by adopting the same anonymous intensity. In this approach, taking into account the significance of quasi-identifier attributes, we carry out the dimension division automatically and obtain multi-constraint anonymous parameters. After that an anonymous algorithm is executed on the separate partition. Experimental results show that the proposed method can obtain a better balance between the privacy protection degree and data availability.

Numerical simulation of reactive flow in non-equilibrium behind a strong shock wave during re-entry into earth’s atmosphere

In this paper, we study the phenomena of thermo-chemical imbalance in a reactive mono-dimensional flow composed of a mixture of (79% nitrogen N2 and 21% oxygen O2 ). We are interested in modeling the physicochemical process that may be encountered in hypersonic flows, as vibrational excitation, dissociation and ionization, also the formation of chemical species to higher temperatures behind a detached strong shock. We put a special emphasis on vibrational relaxation model of CVD coupling. At these high temperatures, collisions electrons-atoms become very effective, taking in account the radiation that requires knowledge and modeling of all physicochemical processes (collisional and radiative). The mathematical model of flows at the atmospheric reentry is governed by Euler stationary equations coupled with the chemical kinetics and the radiative transfer equations. Our computational code is based on the finite differences method that used to discretize and resolve the obtained numerical model, where an appropriate mesh is selected in the relaxation zone in order to determine the flow parameters at each grid position

The Hydraulic Stability of Heating Network with Remote Measurement and Control System

In order to eliminate hydraulic imbalance phenomenon of the heating network, this article briefly introduces the operation principle of the system. The remote control system uses computer information and communication technology to monitor the network flow, through the pressure curve to estimate the hydraulic condition. According to the analysis of pipe resistance properties and the hydraulic balance calculation, the system will change the valve opening intelligently, to make the heating network running in a hydraulic balance condition. The vortex flow meter and flow control valve can be used to adjust the water flow of primary and secondary network, such measure will ensure the hydraulic stability of heating system, save the thermal energy consumption.

Asymptotic rejection of sinusoidal disturbances based voltage balance control in back-to-back power converters

SUMMARY This paper addresses the imbalance problem of the dc-link capacitor voltages in the three-level diode-clamped back-to-back power converter. In order to cope with it, a mathematical analysis of the capacitor voltage difference dynamics, based on a continuous model of the converter, is first carried out. It leads to an approximated model that contains explicitly several sinusoidal functions of time. In view of this result, the voltage imbalance phenomenon can be addressed as an output regulation problem, considering the sinusoidal functions of time as exogenous disturbances. Thus, a novel approach to deal with the mentioned problem in the back-to-back converter is presented. Then, the particular features of the disturbances are used to design several controllers. They all follow an asymptotic disturbance rejection approach. In this way, the estimates of the disturbances are used to apply a control law that cancels them while regulating the capacitor voltage balance as well. Finally, the performance of the proposed control laws is evaluated, presenting the simulation results obtained when the different controllers are implemented. Copyright © 2013 John Wiley & Sons, Ltd.

TargetATPsite: A template‐free method for ATP‐binding sites prediction with residue evolution image sparse representation and classifier ensemble

Understanding the interactions between proteins and ligands is critical for protein function annotations and drug discovery. We report a new sequence-based template-free predictor (TargetATPsite) to identify the Adenosine-5'-triphosphate (ATP) binding sites with machine-learning approaches. Two steps are implemented in TargetATPsite: binding residues and pockets predictions, respectively. To predict the binding residues, a novel image sparse representation technique is proposed to encode residue evolution information treated as the input features. An ensemble classifier constructed based on support vector machines (SVM) from multiple random under-samplings is used as the prediction model, which is effective for dealing with imbalance phenomenon between the positive and negative training samples. Compared with the existing ATP-specific sequence-based predictors, TargetATPsite is featured by the second step of possessing the capability of further identifying the binding pockets from the predicted binding residues through a spatial clustering algorithm. Experimental results on three benchmark datasets demonstrate the efficacy of TargetATPsite.

An Analysis of Education Globalization and the Chinese Education Trade Imbalance: An International Student Flow and Service Trade Perspective

Globalization is an irreversible trend in economics. This paper hypothesizes that the highly segmented education market has also followed this trend and has started fast globalization, signaled by the increasing international student flow worldwide. Factors that facilitate this education globalization are analyzed. Retrospective data on student inflow to and outflow from China are studied from the service trade perspective. The interesting phenomenon of the inverse education service trade imbalance in China is outlined. Remediating measures based on the core competence theory for this imbalance are proposed. Outward looking projections are also presented.

An Exploration to Imbalance of Network Information Ecological System in an Economic Perspective

Starting from the characteristics of network information ecological system, this paper lists and analyzes the phenomena of imbalance of network information ecological system, i.e. the systematic nature, the openness, the diversity, the self-organization and continuous coordinative development, and the evolvement. In an economic perspective, the author analyzes certain issues concerning the imbalance of network information ecological system, such as the information overload, the information acquisition, the information monopoly, and the information pollution. Finally, the author proposes several suggestions for maintaining the network information ecological balance. Key words: Network information ecological system; Imbalance; Economic perspective

From the Edge of Oblivion

From the Edge of Oblivion

Influence of Scale Effect on Filling Behavior of Injection Molding by Visualization Method

Abstract For better understanding of thin-wall injection molding processes, a visualization injection mold and high speed camera were used to observe the dynamic filling behavior of melt in cavities with different thicknesses during the injection molding process. The impact of the scale effect on the melt-filling rate and filling imbalance in the multi-cavity were also studied. Results indicated that the filling behavior of the melt during the multi-cavity molding process was related to the cavity thickness. The experiment results can be used to describe the filling imbalance phenomenon during the injection molding process and to provide experimental evidence for precise injection molding technology at the micro scale.

An Improvement on Current Sharing Characteristics of Poloidal Field (PF) AC-DC Converters

In response to the current imbalance phenomenon and its harmfulness, a current sharing circuit model is built up, which reveals the underlying causes for the current imbalance through a quantitative analysis. Then, a feasible approach of improvement, namely enlargement of the length of connection busbars, is proposed. After the amendment, it can be seen that the current sharing coefficient is almost unity under rated or fault current conditions.

Reflections on modern China and the progressive power of educational studies

The turn towards using domestic experience in contemporary Chinese educational studies has led to the development of theoretical frames rooted in the reality of Chinese society. This article identifies four ways of understanding and reforming Chinese society that have been developed by 20th century Chinese educators. By reflecting on these four approaches, and on the modern value oriented reactions to social transformation expressed by contemporary Western educational scholars, this article argues that Chinese educational scholars face two essential tasks when developing theories based on domestic experience so as to make positive contributions to China’s unfinished project of modernity. The first is to study the phenomena of imbalance, alienation, and backwardness caused by all kinds of economic and cultural movements and forces in the huge space of Chinese society, and the second is to develop progressive educational ideas that are robust enough to counter these phenomena.

다수 캐비티 사출금형에서의 균형 충전을 위한 러너 시스템 연구

사출성형은 열가소성 수지의 가공법으로 정밀도나 고품질의 제품을 효과적으로 생산하는데 널리 이용되는 기술이다. 다수 캐비티 사출성형에서 캐비티 충전 불균형이 발생하는데 이러한 현상은 사출성형품의 치수 및 중량의 편차 뿐 아니라 물리적 특성에 영향을 미치고 있다. 충전 불균형은 충전 단계에서 러너 내에서 발생되는 불균일한 전단분포에 기인하여 발생되므로 점도 변화에 영향을 주는 수지의 물성, 사출조건 등 성형공정 조건 요인에 의해 충전 불균형의 양상이 다르게 된다. 본 논문에서는 점도 및 물성이 다른 PC, PP 수지에 대하여 성형조건에 따른 충전 현상을 관찰하고 원인을 분석하였고 사출속도에 따른 충전 불균형 현상의 원인을 고찰하기 위해 사출성형실험과 CAE 해석을 수행하였다. CAE 해석을 수행하여 각 수지마다 사출속도에 따른 충전 패턴 경향과 온도분포를 예측하고 캐비티 간 충전 균형을 위해 새로운 볼륨 러너 시스템을 제시하였고 캐비티 간 충전 균형을 확인 할 수 있었다. In this study, flow characteristics in a multi-cavity injection molding process were investigated. One of main problems occurred in the multi-cavity molding is a flow imbalance among cavities since it affects physical properties and quality of products. Charge imbalance is caused by the uneven shear stress. Therefore, changes in viscosity affect the physical properties of resin and injection conditions differ in the filling imbalance phenomenon. Through, this study focus on experimental studies of flow imbalance for PC and PP resin occurring in a balanced delivery system. Experimental results were compared with CAE results. By experimental and CAE analysis, main cause for the flow imbalance is temperature distribution in cross section of runner. New runner system with a simple change of runner shape was suggested to avoid the flow imbalance. A series of simulation to confirm feasibility of Volume Runner's effects was conducted using injection molding CAE.

A comparison of eddy-covariance and large aperture scintillometer measurements with respect to the energy balance closure problem

Abstract. We analyzed the seasonal variations of energy balance components over three different surfaces: irrigated cropland (Yingke, YK), alpine meadow (A'rou, AR), and spruce forest (Guantan, GT). The energy balance components were measured using eddy covariance (EC) systems and a large aperture scintillometer (LAS) in the Heihe River Basin, China, in 2008 and 2009. We also determined the source areas of the EC and LAS measurements with a footprint model for each site and discussed the differences between the sensible heat fluxes measured with EC and LAS at AR. The results show that the main EC source areas were within a radius of 250 m at all of the sites. The main source area for the LAS (with a path length of 2390 m) stretched along a path line approximately 2000 m long and 700 m wide. The surface characteristics in the source areas changed with the season at each site, and there were characteristic seasonal variations in the energy balance components at all of the sites. The sensible heat flux was the main term of the energy budget during the dormant season. During the growing season, however, the latent heat flux dominated the energy budget, and an obvious "oasis effect" was observed at YK. The sensible heat fluxes measured by LAS at AR were larger than those measured by EC at the same site. This difference seems to be caused by the so-called energy imbalance phenomenon, the heterogeneity of the underlying surfaces, and the difference between the source areas of the LAS and EC measurements.

PROJECTING AWAY THE CLASS IMBALANCE PROBLEM IN AUTHOR ATTRIBUTION

Author identification algorithms attempt to ascribe document to author, with an eye towards diverse application areas including: forensic evidence, authenticating communications, and intelligence gathering. We view author identification as a single label classification problem, where 2000 authors would imply 2000 possible categories to assign to a post. Experiments with a naive Bayes classifier on a blog author identification task demonstrate a remarkable tendency to over-predict the most prolific authors. Literature search confirms that the class imbalance phenomenon is a challenge for author identification as well as other machine learning tasks. We develop a vector projection method to remove this hazard, and achieve a 63% improvement in accuracy over the baseline on the same task. Our method adds no additional asymptotic computational complexity to naive Bayes, and has no free parameters to set. The projection technique will likely prove useful for other natural language tasks exhibiting class imbalance.

Study of Structure of Co-axial Multi-layered HTS Power Cable based on Low AC Loss using Efficient 3-D FEM Analysis

Controlling the current distribution in each layer of a co-axial multi-layered high-T c superconducting (HTS) cable uniformly is important in order to realize a compact and large capacity HTS power cable. The phenomenon of current imbalance should be exactly investigated by the analysis, because the current imbalance causes an increase of AC loss. In this paper, 3-D finite element analysis taking account of the nonlinear E-J characteristic is carried out in order to study the AC loss of a co-axial multi-layered HTS power cable with shield layers. The analysis region is considerably reduced by modeling spirally wound superconducting tapes as conductors having an anisotropic conductivity and using the periodic boundary condition. By using this model, AC transport characteristics of the co-axial three-layers cable (composed of two conductor layers and one shield layer) are studied, and the AC loss is investigated. The structure with low AC loss is also discussed.

Experiment Study on Filling Imbalance Phenomenon of Melt Front during Injection Molding Process

Filling balance of injection molding is one of the main factors that influence the precision of plastic products.During the injection molding process,when polymer melt is filling the mold cavity,the flow forefront may shift left and right,thus causing filling imbalance.In order to make clear the mechanism of filling imbalance,one set of movable temperature measuring system equipped with infrared fiber sensor is designed.This system and visualization method are adopted to observe and analyze the aforesaid shifting phenomenon.The experimental results show that the shifting phenomenon and shifting degree of flow forefront at different filling speed are also different.The shifting of flow forefront is related to the flow behavior of melt in the runner and the variation of temperature field.A model of flow behavior of melt in the runner is constructed according to the experimental results and shear heat theory.The model can well describe the formation mechanism of the filling imbalance phenomenon.Tracer experiment of melt flow in the runner shows that the model coincides well with the actual situation.

An improved Hilbert curve for parallel spatial data partitioning

A novel Hilbert-curve is introduced for parallel spatial data partitioning, with consideration of the huge-amount property of spatial information and the variable-length characteristic of vector data items. Based on the improved Hilbert curve, the algorithm can be designed to achieve almost-uniform spatial data partitioning among multiple disks in parallel spatial databases. Thus, the phenomenon of data imbalance can be significantly avoided and search and query efficiency can be enhanced.

웹 클러스터 시스템의 실시간 서버 상태를 기반으로 한 부하분산 방안

웹 클러스터 시스템에서 사용자들의 접속 요구를 효율적으로 real 서버에 분산시키기 위하여 기존의 부하분산 알고리즘들과 현재 많이 사용중인 WLC(Weighted Least Connection) 알고리즘에 대하여 연구하였다. 이 부하분산 알고리즘들은 서버들의 부정확한 부하상태 파악과 파악 시점에 문제가 있어 서버들 간에 부하 불균형이 발생함으로써 효율성이 저하된다. 본 연구에서는 사용자의 접속 요청 시 broadcasting RPC(Remote Procedure Call)를 이용하여 서버들의 다양한 부하상태를 실시간으로 파악하여 부하를 분산하는 알고리즘을 제안하고, prototype을 구현하여 성능을 실험하였다. 실험 결과, real 서버 간 부하 불균형 현상이 기존 방법에 비하여 크게 향상되었고, 응답시간이 단축되는 효과로 웹 클러스터 시스템의 성능이 향상되었다. I studied about existent load distribution algorithms and the WLC(Weighted Least Connection) algerian that is using much at present to distribute the connection request of users to real servers efficiently in web cluster system. The efficiency of web cluster system is fallen by load imbalance between servers, because there is problem In inaccurate load status measuring of servers and measuring timing at these load distribution algorithms. In this paper, I suggest an algorithm that distributes load base on various load state of servers by real time using broadcasting RPC(Remote Procedure Call) when a user requests connection, and implement a prototype and experiment its performance. The experiment result shows that load imbalance phenomenon between reai sowers was improved greatly than existing method, and performance of web cluster system was improved by efficiency that response time is shortened.

Case report: delirium associated with ovarian hyperstimulation syndrome

Ovarian hyperstimulation syndrome (OHSS) is one of the most important complications of assisted reproductive technologies. Mild OHSS is characterized by ovarian enlargement and abdominal discomfort. In severe cases anasarca, hepatic dysfunction, reduced blood volume, electrolyte imbalance, organ failure and thromboembolic phenomena may be observed. Delirium is a syndrome, not a disease, and has many causes, all of which result in a similar pattern of signs and symptoms relating to a patient's level of consciousness and cognitive impairment. Delirium remains an under-recognized and under-diagnosed clinical disorder. The case is presented of a 30-year-old woman with OHSS and delirium. She underwent intracytoplasmic sperm injection (ICSI) for severe male factor infertility. Five days after oocyte retrieval, ascite formation was observed in ultrasonographic evaluation, and embryo transfer was cancelled. Twelve days after retrieval she came to the emergency clinic with abdominal distension and pain. She was hospitalized and paracentesis was performed every other day three times. She had altered consciousness and psychomotor hypoactivity 1 h after the last paracentesis. Psychiatric consultation revealed that she was in a state of delirium, and haloperidol was administered for treatment. Her symptoms disappeared within a week. Her medication was stopped when symptoms resolved and she was still asymptomatic in psychiatric evaluation 1 week later.