双燃料大型集装箱船LNG燃料供气系统设计

液化天然气(LNG)以低温常压形式储存,喷入主机燃烧之前需经过供气系统进行处理,将其转换成具有合适温度压力的气体燃料。燃料供气系统性能的好坏直接影响燃气质量,进而影响设备运行效率。以20 000箱LNG/柴油双燃料远洋大型集装箱船为研究对象,对LNG气体燃料供气系统进行深入研究。结合供气系统工作流程,充分分析供气系统组成及各部分功能,并对方案中关键设备进行选型研究,提出供气系统完整设计方案,设计方案满足实际使用需求并可为相关设计提供参考。

A Distributed Cell Outage Compensation Mechanism Based on RS Power Adjustment in LTE Networks

To solve the coverage and quality problems caused by cell outage in LTE networks, this paper proposes a distributed self-organizing networks management architecture and a distributed cell outage compensation management mechanism. After detecting and analyzing the outage, a cell outage compensation algorithm based on reference signal power adjustment is proposed. The simulation results show that the proposed mechanism can mitigate the performance degradation significantly. Compared with other algorithms, the proposed scheme is more effective in compensating the coverage gap induced by cell outage

Research on Testing System for Three-dimensional Distribution of Luminous Intensity of LED

In terms of asymmetrical three-dimensional distribution(ID) of luminous intensity(LI) of light-emitting-diode(LED),a testing system was conducted in this study. Design and principle of the testing system were introduced. 31 photometers were placed on a concentric circle,and all of them were used to gather LI data of LED at the same time. The data acquisition card(DAC) was used to gather multichannel data and controlled motor. Experimental results indicated that the testing system had achieved the goal of testing three-dimensional distribution of LI. And each parameter could meet the requirements of industrial production and measurement.

Development of a distribution management system in refinery industry

Developing an information system for managing the product distribution in a refinery demands sophisticated design solutions. First, organization models are created to describe the structural relationships among employees and the ways in which they will use the information system. Second, function models are created to hierarchically describe how sales, transports, deliveries and vehicles are managed. Thirdly, an information model is built to represent the data entities and their dynamic interactions. Based on the system design, a distribution management system is developed and implemented in a refinery, which has considerably increased the distribution management efficiency and effectiveness.

Research on logistics domain-oriented cloud resource management model and architecture

To address the challenges posed by resource shortage or surplus to enterprises productivity,Internet platforms have been widely used,which can balance shortage and surplus in broader environments. However,the existing resource management models lack openness,sharing ability and scalability,which make it difficult for many heterogeneous resources to co-exist in the same system. It is also difficult to resolve the conflicts between distributed self-management and centralized scheduling in the system. This paper analyzes the characteristics of resources in the distributed environment and proposes a new resource management architecture by considering the resource aggregation capacity of cloud computing. The architecture includes a universal resource scheduling optimization model which has been applied successfully in double-district multi-ship-scheduling multi-container-yard empty containers transporting of international shipping logistics. Applications in all these domains prove that this new resource management architecture is feasible and can achieve the expected effect.

Consumer Central Energy Flexibility in Office Buildings

Energy flexibility in buildings will play an important role in the smart energy system. Office buildings have more potentials to provide energy flexibility to the grid compared to other types of buildings, due to the existing building management, control systems and large energy consumption. Consumers in office buildings （building owners/managers and occupants） take a main role for adopting and engaging in building energy flexibility. This paper provides a systematic review of consumer central energy flexibility in office buildings with the discussion of social, technical and business aspects. This paper clarifies the correlations of consumers＇ concems, external influential factors, energy flexibility resources and technology with eight hypotheses. This paper suggests that technical solutions with the integration of distributed energy resources, building management and control system can boost energy flexibility in the office buildings.

Controllable Optical Solitons in Optical Fiber System with Distributed Coefficients

We present how to control the dynamics of optical solitons in optical fibers under nonlinearity and dispersion management, together with the fiber loss or gain. We obtain a family of exact solutions for the nonlinear Schrfidinger equation, which describes the propagation of optical pulses in optical fibers, and investigate the dynamical features of solitons by analyzing the exact analytical solutions in different physical situations. The results show that under the appropriate condition, not only the group velocity dispersion and the nonlinearity, but also the loss/gain can be used to manipulate the light pulse.

Experimental Study on Rack Cooling System based on a Pulsating Heat Pipe

A rack cooling system based on a large scale flat plate pulsating heat pipe is proposed. The heat generated from IT equipment in a closed rack is transferred by the rear door pulsating heat pipe to the chilled air passage and is avoided to release into the room. The influence of the start-up performance of the heat pipe, the load of the rack and the load dissipation to the temperature and the velocity distribution in the rack are discussed. It is found that the temperature would be lower and the temperature distribution would be more uniform in the rack when the pulsating heat pipe is in operation. Also, the effect of rack electricity load on temperature distribution is analyzed. It is indicated that higher velocity of chilled air will improve heat transfer of the rack.

ONFS： a hierarchical hybrid file system based on memory, SSD, and HDD for high performance computers

With supercomputers developing towards exascale, the number of compute cores increases dramatically, making more complex and larger-scale applications possible. The input/output （I/O） requirements of large-scale applications, workflow applications, and their checkpointing include substantial bandwidth and an extremely low latency, posing a serious challenge to high performance computing （HPC） storage systems. Current hard disk drive （HDD） based underlying storage systems are becoming more and more incompetent to meet the requirements of next-generation exascale supercomputers. To rise to the challenge, we propose a hierarchical hybrid storage system, on-line and near-line file system （ONFS）. It leverages dynamic random access memory （DRAM） and solid state drive （SSD） in compute nodes, and HDD in storage servers to build a three-level storage system in a unified namespace. It supports portable operating system interface （POSIX） semantics, and provides high bandwidth, low latency, and huge storage capacity. In this paper, we present the technical details on distributed metadata management, the strategy of memory borrow and return, data consistency, parallel access control, and mechanisms guiding downward and upward migration in ONFS. We implement an ONFS prototype on the TH-1A supercomputer, and conduct experiments to test its I/O performance and scalability. The results show that the bandwidths of single-thread and multi-thread ＇read＇/＇write＇ are 6-fold and 5-fold better than HDD-based Lustre, respectively. The I/O bandwidth of data-intensive applications in ONFS can be 6.35 timcs that in Lustre.