One-way System Research Articles

Lymphatic myogenic constriction – how lymphatic vessels pump lymph uphill

Lymphatic myogenic constriction – how lymphatic vessels pump lymph uphill

Coupling a Mesoscale Atmospheric Model with a Distributed Hydrological Model Applied to a Watershed in Southeast Brazil

AbstractReliable hydrometeorological forecasts are necessary to help reduce damages caused by extreme events. Coupling atmospheric and hydrological models can help improve those forecasts; therefore, the main objective of this work is to propose, apply, and evaluate a one-way coupled system involving an atmospheric and a hydrological model. The models were applied to a watershed in the Serra do Mar region, Sao Paulo State, Brazil. Because of the complex terrain and native tropical forest (Mata Atlântica), hydrometeorological modeling in this region requires specific studies and adequate models. The coupling was carried out between the atmospheric regional Eta model and the distributed hydrology soil vegetation model. The primary challenge in coupling hydrological and atmospheric models is the large difference in spatial and temporal scales in which these models operate. This study proposes a downscaling methodology to increase the spatial resolution of precipitation and temperature predicted by the atmosp...

Nonlinear Precoding Design for MIMO Amplify-and-Forward Two-Way Relay Systems

In traditional multiple-input-multiple-output (MIMO) channel and MIMO one-way relay system, nonlinear precoding design has shown significant performance gain over linear design. In this paper, we aim to study nonlinear precoding design for MIMO amplify-and-forward (AF) two-way relay systems, where nonlinear minimal mean square error (MMSE) decision feedback equalizers (DFEs) are used in two destinations, and linear transmit precoding is applied at the source and relay nodes. We first investigate nonlinear precoding design, where the precoding is only conducted at two sources for a fixed-relay precoder. After some transformations, we prove that this design problem is convex, and an efficient algorithm is provided to find the optimal solution. Then, we consider the nonlinear joint precoding design to further incorporate relay precoding. Due to the nonconvexity of this problem, we first propose an iterative algorithm (Algorithm I) to approach the optimal solution. It is proven that Algorithm I is convergent and can converge to a stationary point of the joint design problem. Moreover, we present a simplified iterative algorithm (Algorithm II) for joint precoding design to reduce the design complexity. It is found that Algorithm II almost achieves the same performance as Algorithm I in most cases. Our simulation results show that the proposed nonlinear joint precoding design significantly outperforms the linear joint precoding design. It is also shown that the choice between the proposed nonlinear source precoding design and the linear relay precoding design is dependent on specific conditions.

등가플레이트 요소를 이용한 일방향 중공슬래브의 동적해석에 관한 연구

Considering that the weight of a hollow slab system is not increased with an incremental increase in its thickness, and that the flexural stiffness of a hollow slab is not significantly lower than that of a general slab, there has been a growing need for hollow slab system, because long span structures are in great demand. In a long span structure, the problem of vibration of floor slabs frequently occurs, and the dynamic characteristics of a hollow slab system are quite different from the conventional floor system. It is required to investigate the safety and the serviceability of hollow slab. Therefore, there exists a necessity for accurate vibration analysis. Hollow slab should be modeled by refined mesh for accurate vibration analysis. For the efficiency of the Eigenvalue Analysis, an equivalent plate slab model when can relatively precisely represent the dynamic behavior of a one-way hollow slab system is used. In conclusion, equivalent plate models relatively precisely presented the dynamic characteristics of one-way hollows.

Reviews of Science for Science Librarians: A Bibliographic Examination of Ornithology

Ornithology is the study of birds. Birds are members of the class Aves. Their most distinguishing feature is the presence of feathers as a covering for their bodies. Feathers enable most birds to fly, which requires a lot of energy and low weight. Researchers study their high metabolism, hollow bones, gizzard, and one-way respiratory system. Birds must eat frequently to minimize heavy fat. They have complicated mating rituals, lay eggs, and make nests. Ornithological research also explores migration, taxonomy, evolution, conservation, and diversity. Volunteers of birdwatching hobbyists are utilized to collect data which lowers costs and workload. This paper presents an annotated bibliography of key monographs, organizations, data sources, field guides, and core journals.

Use of ICT for Open and Distance Learning in KNOU

Korea National Open Universities have been utilized one-way instructional delivery system during the history of distance education from 1972. The isolation of students in their learning is the most important problem to solve in this one-way mode. ICT application like e-Learning or m-Learning is an alternative instructional model that makes available student to have more interaction with their instructor and peer, is more accessibility to multimedia learning resources than the traditional delivery system. On behalf of starting 4 departments online graduate school program e-Learning center had established and 2002, e-Learning hub site “e-Campus” was launched. From December 2008 KNOU kick off the mobile learning system under the MOU with Korean Telephone Company KT. In 2012 KNOU opened the new chapter of Smart Learning using KNOU applet of smart phone. Mobile technologies, like mobile devices and wireless internet services, have the potential to introduce new innovations in the area of education. This paper aims to share experiences from the process of ICT adaptation at KNOU open and distance learning with both national and international perspectives.

Distributed joint source-channel coding for relay systems exploiting source-relay correlation and source memory

In this article, we propose a distributed joint source-channel coding (DJSCC) technique that well exploits source-relay correlation as well as source memory structure simultaneously for transmitting binary Markov sources in a one-way relay system. The relay only extracts and forwards the source message to the destination, which implies imperfect decoding at the relay. The probability of errors occurring in the source-relay link can be regarded as source-relay correlation. The source-relay correlation can be estimated at the destination node and utilized in the iterative processing. In addition, the memory structure of the Markov source is also utilized at the destination. A modified version of the Bahl, Cocke, Jelinek, and Raviv (BCJR) algorithm is derived to exploit the memory structure of the Markov source. Extrinsic information transfer (EXIT) chart analysis is then performed to investigate convergence property of the proposed technique. Results of simulations conducted to evaluate the bit-error-rate (BER) performance and the EXIT chart analysis show that, by exploiting the source-relay correlation and source memory simultaneously, our proposed technique achieves significant performance gain, compared with the case where the correlation knowledge is not fully used.

Experimental demonstration of an active phase randomization and monitor module for quantum key distribution

Phase randomization is a very important assumption in the BB84 quantum key distribution (QKD) system with weak coherent source; otherwise, eavesdropper may spy the final key. In this Letter, a stable and monitored active phase randomization scheme for the one-way and two-way QKD system is proposed and demonstrated in experiments. Furthermore, our scheme gives an easy way for Alice to monitor the degree of randomization in experiments. Therefore, we expect our scheme to become a standard part in future QKD systems due to its secure significance and feasibility.

Crowd and environmental management during mass gatherings

Crowds are a feature of large cities, occurring not only at mass gatherings but also at routine events such as the journey to work. To address extreme crowding, various computer models for crowd movement have been developed in the past decade, and we review these and show how they can be used to identify health and safety issues. State-of-the-art models that simulate the spread of epidemics operate on a population level, but the collection of fine-scale data might enable the development of models for epidemics that operate on a microscopic scale, similar to models for crowd movement. We provide an example of such simulations, showing how an individual-based crowd model can mirror aggregate susceptible-infected-recovered models that have been the main models for epidemics so far.

One-Way Carsharing

Carsharing services allow users to benefit from the advantages of a private car without the costs of owning one. One-way systems provide users with a higher level of service than traditional carsharing systems in terms of flexibility because users do not need to return to the station of origin. Moreover, the added option to leave the vehicle at any free parking area, which is not necessarily a station, increases the flexibility offered by the one-way system. Introduction of such improvements to the carsharing system, however, leads to a vehicle relocation problem, which should be addressed carefully to avoid concentration of vehicles in certain areas. This paper reports on a study of this issue with the use of discrete event systems (DESs), which allowed an easy representation of the complex dynamics of the carsharing system. A user-based methodology was proposed on the basis of an optimal relocation policy in a rolling horizon framework. This methodology not only offers greater flexibility to users, it also maximizes operator benefits by reducing the number of required staff to relocate vehicles among the stations and determines the minimum number of vehicles needed to satisfy system demand. The DES model was applied to a case study to evaluate the proposed approach. The results showed a significant decrease in the rejection rate from the worst scenario (no relocation) to the best (relocation of all vehicles by their users). The paper concludes with suggestions for additional research and improvements to this study.

The Sign-Definiteness Lemma and Its Applications to Robust Transceiver Optimization for Multiuser MIMO Systems

We formally generalize the sign-definiteness lemma to the case of complex-valued matrices and multiple norm-bounded uncertainties. This lemma has found many applications in the study of the stability of control systems, and in the design and optimization of robust transceivers in communications. We then present three different novel applications of this lemma in the area of multi-user multiple-input multiple-output (MIMO) robust transceiver optimization. Specifically, the scenarios of interest are: (i) robust linear beamforming in an interfering adhoc network, (ii) robust design of a general relay network, including the two-way relay channel as a special case, and (iii) a half-duplex one-way relay system with multiple relays. For these networks, we formulate the design problems of minimizing the (sum) MSE of the symbol detection subject to different average power budget constraints. We show that these design problems are non-convex (with bilinear or trilinear constraints) and semi-infinite in multiple independent uncertainty matrix-valued variables. We propose a two-stage solution where in the first step the semi-infinite constraints are converted to linear matrix inequalities using the generalized sign-definiteness lemma, and in the second step, we use an iterative algorithm based on alternating convex search (ACS). Via simulations we evaluate the performance of the proposed scheme.

스마트그리드 AMI환경에서의 ID기반 인증기법에 관한 연구

최근 기존의 단 방향 전력망 시스템에 정보통신기술을 접목한 스마트그리드 기술의 개발이 활발하게 이루어지고 있다. 스마트그리드의 핵심 인프라로 원격검침시스템인 AMI는 스마트미터에서 측정한 전력량을 상위 데이터 저장소인 MDMS에 전송한다. 스마트미터는 정보통신기술을 활용하여 전력데이터를 전송하고 있기 때문에 기존 보안위협을 포함한 추가적인 보안위협이 예상된다. 이는 소비자의 개인정보노출 및 산업시스템 마비 등의 손실이 발생할 가능성이 있다. 따라서 본 논문은 이러한 보안위협에 대응하기 위해 스마트그리드 환경에서 스마트미터와 MDMS간 그리고 각 가정의 디바이스와 MDMS간의 상호인증과 전력량 데이터 전송방식에 관하여 제안하였다. Recently the existing one-way electricity system that combines information and communications technology to develop smart grid technology is made active. The core infrastructure of the smart grid, AMI smart meters to AMR system, the amount of power measured at the top to MDMS transmits data store. Smart meters utilizing information and communication technology to transfer data and power because of the existing security threats are expected, including the additional security threats. It exposes the privacy of consumers and industrial systems, such as paralysis is likely to result in the loss. In this paper to respond to these security threats in the environment smart grid. Also, We propose data transfer methods between smartmeter and MDMS and between home device and MDMS.

Cost Optimization of Reinforced Concrete One-Way Ribbed Slabs Using Harmony Search Algorithm

Cost optimization of a reinforced concrete one-way joist floor system consisting of a hollow slab is presented in this paper. The cost of the system is considered to be the objective function, and the design is based on the American Concrete Institute’s ACI 318-05 standard. This function is minimized, subject to design constraints, using the harmony search algorithm. A numerical example is presented to illustrate the performance of the algorithm and a sensitivity analysis is performed. A parametric study is also conducted to investigate the effects of the beam span and the loading on the cost optimization of the ribbed slab.

Design and Characterization of Endosomal‐pH‐Responsive Coiled Coils for Constructing an Artificial Membrane Fusion System

A weakly acidic pH-responsive polypeptide is believed to have the potential for an endosome escape function in a polypeptide-triggered delivery system. For constructing a membrane fusion device with pH-responsiveness, we have designed novel polypeptides that are capable of forming an α2 coiled coil structure. Circular dichroism spectroscopy reveals that a polypeptide, AP-LZ(EH5), with a Glu and His salt-bridge pair at a staggered position in the hydrophobic core forms a stable coiled coil structure only at endosomal pH values (pH 5.0 to 5.5). On the basis of their endosomal-pH responsiveness, a boronic acid/polypeptide conjugate (BA-H5-St) was also designed as a pilot molecule to construct a pH-responsive, one-way membrane fusion system with a sugarlike compound (phosphatidylinositol: PI)-containing liposome as a target. Membrane fusion behavior was characterized by lipid-mixing, inner-leaflet lipid-mixing, and contents-mixing assays. These studies reveal that membrane fusion is clearly observed when the pH of the experimental system is changed from 7.4 (physiological condition) to 5.0 (endosomal condition).

Analysis of a production-oriented air hybrid engine concept and its performance

In this paper, an air hybrid engine concept with an one-way intake system will be described and analysed. The investigation started with systematic studies on the effect of various valve opening and closing events on the performance of Compressor Mode (CM) and Expander Mode (EM) operations. After having defined the optimal valve timings for CM and EM operations over a range of engine speeds, the effect of other operating parameters on the performance of the air hybrid engine, such as buffer (or auxiliary) chamber volume, airtank volume and pressure, etc., is examined. It is shown that this concept can be readily implemented in production engines with existing production VVA technologies. The predicted results indicate that it is capable of performing good regenerative braking and large driving torque to start and motor the engines using the stored compressed air.

Joint Optimization for One and Two-Way MIMO AF Multiple-Relay Systems

This paper considers both one-way and two-way relaying systems with multiple relays between two terminal nodes where all nodes have multiple-input multiple-output (MIMO) antennas. We propose a unified algorithm which computes the optimal linear transceivers jointly at the source node and the relay nodes for amplify-and-forward (AF) protocols. First, optimization designs based on the sum-rate and the mean-square error (MSE) criteria are formulated for the two-way AF relaying channel. Due to non-convexity of the given problems, the proposed schemes iteratively identify local-optimal source and relay filters by deriving the gradients of the cost functions for a gradient descent algorithm. Then, the proposed algorithm can optimize a one-way multiple relay system as a special case of the two-way channel. Finally, we prove the global optimality of the maximum sum-rate scheme under an asymptotically large antenna assumption. From simulation results, it is confirmed that the proposed methods yield the near optimum result for the MIMO multiple relay channel even with a moderate number of antennas. Consequently, we show that the proposed algorithm outperforms conventional schemes in terms of the sum-rate and the error performance for both one-way and two-way protocols.

Study on the micro-scale simulation of wind field over complex terrain by RAMS/FLUENT modeling system

A meteorological model, RAMS, and a commercial computational fluid dynamics (CFD) model, FLUENT are combined as a one-way off-line nested modeling system, namely, RAMS/FLUENT system. The system is experimentally applied in the wind simulation over a complex terrain, with which numerical simulations of wind field over Foyeding weather station located in the northwest mountainous area of Beijing metropolis are performed. The results show that the method of combining a meteorological model and a CFD model as a modeling system is reasonable. In RAMS/FLUENT system, more realistic boundary conditions are provided for FLUENT rather than idealized vertical wind profiles, and the finite volume method (FVM) of FLUENT ensures the capability of the modeling system on describing complex terrain in the simulation. Thus, RAMS/FLUENT can provide fine-scale realistic wind data over complex terrains.

Target-Selective One-Way Membrane Fusion System Based on a pH-Responsive Coiled Coil Assembly at the Interface of Liposomal Vesicles

The coiled coil trimer structure is a common motif observed in membrane fusion processes of specific fusion proteins such as the hemagglutinin glycoprotein. The HA2 subunit in the hemagglutinin changes its conformation or geometry to be favorable to membrane fusion in response to endosomal weakly acidic pH. This pH responsiveness is indispensable to an artificial polypeptide-triggered delivery system as well as the membrane fusion reaction in biology. In this study, we have constructed an AAB-type coiled coil heteroassembled system that is sensitive to weakly acidic pH. The heterotrimer is formed from two kinds of polypeptides containing an Ala or a Trp residue at a hydrophobic a position, and it was observed that the Glu residue at the other a position induced an acidic pH-dependent conformational change. On the basis of this pH-responsive coiled coil heteroassembled system, a boronic acid coupled working polypeptide for the combination of an intervesicular complex with a sugarlike compound on the surface of the target liposome, and a supporting polypeptide for the construction of a pH-responsive heterotrimer with the working polypeptide were designed and synthesized. The process of membrane fusion was characterized by lipid-mixing, inner-leaflet lipid-mixing, and content-mixing assays. The target selective vesicle fusion is clearly observed at a weakly acidic pH, where the working polypeptides form a heterotrimeric coiled coil with the supporting polypeptides in a 1:2 binding stoichiometry and the surfaces between pilot and target vesicles come into close proximity to each other.

A one-way system for sound

'Acoustic rectifier' is a diode for sound waves.

Computational Fluid Dynamics Study of Liquid Droplet Impingement Erosion in the Inner Wall of a Bent Pipe

The bent pipe wall thinning phenomenon has been often found at the elbow of pipelines in the power engineering industry. Liquid droplet impingement (LDI) erosion could be regarded to be one of the major causes of unexpected troubles occasionally occurred in the inner bent pipe surface. In this paper, three-dimensional numerical simulations are conducted for a bent pipe. Typically the pipe diameter is 170mm and the bending angle is 90 degree, the mass flow rate of droplet is 4.5×10-3 kg/s with the velocity of 280m/s at the entry. The calculations employ a two-phase flow model. A computational fluid dynamic tool has been adopted by using one-way and two-way fluid-droplet coupled system in high Reynolds number regions. This computational fluid model is built up by incompressible Reynolds averaged Navier-Stokes equations using different turbulent flow computational models and the SIMPLE algorithm, and the numerical droplet model adopts the Lagrangian approach. The momentum transfers between droplet and carrier fluid are calculated by using two different fluid-droplet coupled methods. The interactional force between carrier and droplet are taken into account by momentum transfer in Eulerian-Lagrangian approaches. Based on the carrier streamlines and droplet trajectories, the two-way calculation using the interactional momentum transfer calculations could be a more appropriate model to simulate the bent pipe wall thinning phenomena, the effects of droplet size are also demonstrated numerically. Finally, it is shown that turbulence models are not sensitive to the involved droplets.