劳海:在软件夹缝里成长

劳海,他的森蓝数据库网络有限公司创建已接近5个年头,依然仅有十来个人。要不是在某次采访中听到广州市信息中心研究室有关人士提起,我们根本不知道有这样的公司存在。尽管公司规模小,但其要吞噬的是"海阔天空"的市场。

拥住寂寞

目送夕阳西下那一刻,才蓦然惊觉:在这世界,寂寞原本无处不在! 在天际徘徊的那一点夕阳是寂寞,在夜空沉默的那一弯新月是寂寞。

Fatigue reliability analysis of fixed offshore structures:A first passage problem approach

This paper describes a methodology for computation of reliability of members of fixed offshore platform structures, with respect to fatigue. Failure criteria were formulated using fracture mechanics principle. The problem is coined as a “first passage problem”. The method was illustrated through application to a typical plane frame structure. The fatigue reliability degradation curve established can be used for planning in-service inspection of offshore platforms. A very limited parametric study was carried out to obtain insight into the effect of important variables on the fatigue reliability.

Subsea rigid jumper design and VIV fatigue evaluation

The purpose of this paper is to present a design procedure for subsea rigid jumper system including strength and fatigue analysis. Special attention gives to a methodology based on DNV-RP-F105 to evaluate jumper fatigue damage caused by vortex induced vibration (VIV). Jumper strength analysis is to determine the jumper con-figuration which can accommodate various load conditions and all possible span lengths driven by installation tole-rances of connected subsea structures. Fatigue analysis includes two parts:thermal fatigue and VIV fatigue. This paper presents the procedure of VIV fatigue damage calculation. An example is given to illustrate above methodologies.

Investigation of a New Vortex-Induced Vibration Suppression Device in Laboratory Experiments

In order to mitigate vortex-induced vibration (VIV) of marine risers, especially to eliminate the phenomenon of frequency 'lock-in', a new suppression device of crescent-shaped flow spoiler was designed with seven different layout schemes. VIV model tests with six flow levels were conducted in a large wind-wave-current flume. In all cases, vibration responses in both in-line and cross-flow cases were measured. With the installation of suppression devices vibration frequency evolution of a riser was analyzed by Morlet wavelet transform. The principle of VIV suppression was interpreted through vibration characteristics. Fatigue life of the riser was calculated by the Palmgren-Miner rule. Compared with a bare riser, vibration of an outfitted riser with suppression devices disturbed the steady flow, the vibration amplitudes in the two flow directions were reduced, and the riser fatigue life was improved.

Evaluation of Hong Kong Convention in the Maritime Industry

The HKC （Hong Kong Convention） adopted by the IMO in 2009 is aimed at ensuring that ships, when being recycled after reaching the end of their operational lives, do not pose any unnecessary risk to human health and safety of the marine environment. The text of the ship recycling Convention was developed with input from the IMO （International Maritime Organization） Member States and relevant NGOs （Non-Governmental Organizations）, and in co-operation with the ILO （International Labor Organization） and the Parties to the Basel Convention. The Convention intends to address all the issues around ship recycling, taking into account that ships sold for scrapping may contain environmentally hazardous substances. It addresses concerns raised about the working and environmental conditions at many of the world ship recycling locations. Regulations in the new Convention cover： the design, construction, operation and preparation of ships so as to facilitate safe and environmentally sound recycling, without compromising the safety and operational efficiency of ships; the operation of ship recycling facilities in a safe and environmentally sound manner; and the establishment of an appropriate enforcement mechanism for ship recycling, incorporating certification and reporting requirements. This paper will present and discuss the evaluation of the Hong Kong Convention. Also it will discuss implementing the Hong Kong convention to improve the recycling business, highlighting the effect of the convention on the maritime industry.

The cause of human fatigue and scenario analysisin the process of marine transportation

The framework of fatigue factors is constructed to reduce the number of maritime accidents caused by human fatigue.Based on the study of maritime human fatigue,by screening and classifying it,there are 15 fatigue factors,which can be classified into 4 types:sleep,rest and rhythm;work factors;personal conditions;environmental factors.These factors are regarded as the variables for constructing scenarios.The importance,uncertainty,influence and dependence of variables and variable pairs were assessed by using morphological analysis,quantitative scales and correlation matrices.Ship movement and workload are selected as the two key variables,which are regarded as the axes of generating scenarios.One of the scenarios is selected as the typical scenario to illustrate the relationship between the causes of fatigue.Then,the analysis framework is constructed according to the fatigue factors relationship,and several potential solutions are proposed,which include the development of foresighted and flexible work plans,and the application of wearable facilities to improve monitoring and assessment systems.The proposed framework lays a theoretical foundation for studying maritime human fatigue,and scenario analysis can provide an effective strategy for reducing crews'fatigue.

FIas the ＂Flying Geese＂ Paradigm Occurred in China？

In economic literature, the term ＇flying geese＂ refers to the movement of capital from developed regions to less developed ones. Using national data from abovescale manufacturing enterprises, this paper investigates whether the experience of ＂flying geese＂ has transpired in China for manufacturing industries. We find that, driven by the effects of agglomeration, prior to the mid-2000s, there had been an increasing concentration of industrial activities in the coastal regions. However, as labor and land costs increased, the manufacturing sector - especially the labor-intensive industries - began to relocate from the coastal to the interior regions.

Decomposition of Energy-related CO_2 Emissions from Shanghai's Industries and Policy Implications

This paper quantifies a decomposition analysis of energy-related CO2 emissions in the industrial sectors of Shanghai over the period 1994-2007.The Log-Mean Divisia Index(LMDI) method is applied to this study in terms of six factors:labor force,labor mobility,gross labor productivity,energy intensity,fuel mix,and emission coefficient.In addition,the decoupling effect between industrial economic growth and CO2 emissions is analyzed to evaluate CO2 mitigation strategies for Shanghai.The results show that all labor productivity has the largest positive effect on CO2 emission changes in the industrial sectors,whereas labor mobility and energy intensity are the main components for decreasing CO2 emissions.Other factors have different effects on CO2 mitigation in different sub-periods.Although a relative decoupling of industrial CO2 emissions from the economic growth in Shanghai has been found,Shanghai should keep pace with the industrial CO2 emissions reduction by implementing low-carbon technology.These results have important policy implications:Plan C is the reasonable choice for Shanghai.

A Study on the Transformation and Upgrading of Manufacturing Industry of Shanghai by Increasing Labor Cost

Manufacturing is an important support for Shanghai＇s participation in global industrial competition and the implementation of the national strategy for manufacturing power. Economic development Globalization has promoted the deep integration of information and industry, put forward higher requirements for the transformation and upgrading of manufacturing industry, relying solely on the rich labor resources advantages can continue to serve Shanghai economic development. Fierce international competition, ＂labor shortage＂, energy security, labor standards and other issues have led to a gradual increase in labor costs.

Fatigue Sensitivity Analysis of Steel Catenary Riser near Touchdown Point

By transforming the platform response obtained from coupled hydrodynamic analysis to the top motions of steel catenary riser (SCR), the nonlinear dynamic analysis of the SCR is carried out in Abaqus/Aqua. In this analysis, the SCR-seabed interaction is well taken into account by introducing the seabed trench model and hysteretic seabed model. The fatigue damage of the SCR near touchdown point (TDP) is calculated using rain-flow counting methodology, and the sensitivity of the fatigue damage to the seabed and wave parameters are investigated. The results indicate that as seabed stiffness increases, the fatigue life and its sensitivity to seabed stiffness decrease. Seabed trenching may benefit the fatigue life of the SCR and the trench position should be elaborated for realistic fatigue damage prediction. Due to the induced platform response, significant wave height and spectral peak period have significant effects on the fatigue damage, thus the short-term sea state bins should be carefully selected from the wave scatter diagram. © 2017, Shanghai Jiaotong University and Springer-Verlag GmbH Germany.

Effect of Transcutaneous Electrical Acupoint Stimulation on Rats with Chronic Exercise-induced Fatigue

Objective： To observe the effect of transcutaneous electrical acupoint stimulation （TEAS） on the rats with exercise-induced fatigue. Methods： Rat model of chromic exercise-induced fatigue was established with increasing load treadmill walking method. The TEAS therapy was operated immediately and 3 h after the exercise from the sixth week. Hippocampal morphology and hypothalamic morphology were observed with HE staining and the expressions of 5-hydroxytryptamine （5-HT） in hippocampus and hypothalamus were tested with immunohistochemical （IHC） staining after 2-week treatment. Results： TEAS released the damage of hippocampal morphology and hypothalamic morphology induced by exercise significantly and reduced the expression of 5-HT in hippocampus and hypothalamus. The difference between the therapy operated immediately and 3 h after exercise was not significant. Conclusion： TEAS could improve the fatigue recovery and athletic ability. The improvement of TEAS on the rats with exercise-induced fatigue was related with the decreased expression of central 5-HT and the reduction of damaged nerve cells.

Simplified Model for Evaluation of VIV-induced Fatigue Damage of Deepwater Marine Risers

A simplified empirical model for fatigue analysis of deepwater marine risers due to vortex-induced vibration (VIV) in non-uniform current is presented. A simplified modal vibration equation is employed according to the characteristics of deepwater top tensioned risers. The response amplitude of each mode is determined by a balance between the energy feeding into the riser over the lock-in regions and the energy dissipated by the fluid damping over the remainder based on the data from self-excited oscillation and forced oscillation experiments of rigid cylinders. Multi-modal VIV fatigue loading is obtained by the square root of the sum of squares approach. Compared with previous works, this model can take fully account of the main intrinsic natures of VIV for low mass ratio structures on lock-in regions, added mass and nonlinear fluid damping. In addition, a closed form solution of fatigue damage is presented for the case of a riser with uniform mass and cross-section oscillating in a uniform flow. Fatigue analysis of a typical deepwater riser operating in Gulf of Mexico and West Africa shows that the current velocity profiles affect the riser’s fatigue life significantly and the most dangerous locations of the riser are also pointed out.

Fatigue crack in large-scale tubular joints for offshore structures

Tubular members have been used for constructing offshore structures. Large-scale fatigue tests of welded tubular K-joints under the balanced in-plane bending brace were carried out to investigate the fatigue behavior of API 2W Gr.50 steel produced by POSCO. The experimental results were verified by numerical approaches and compared with the IIW, DnV RP-C203 and API RP 2A-WSD design curves. The test results based on the hot spot stress were in agreement with the design curves. The SCF factor for tubular K-joint was also obtained. The numerical parametric study of the K-joint (using the finite element program) was described and its results were compared with experimental results. The stress effects of various parameters including α, β, γ, τ and θ on the stress in the K-joint were investigated. The stress distribution for each parameter was introduced. The study showed that the maximum stress of the joint varied according to the variation of joint parameters.

Effect of Point Sticking Therapy on Biochemical Markers and Rating of Perceived Exertion in Athletes with Exercise-induced Fatigue

Objective： To observe the effect of point sticking therapy on biochemical markers and Rating of Perceived Exertion （RPE） in athletes with exercise-induced fatigue. Methods： A total of 35 football players were randomly allocated into a blank group, a control group and an observation group. The athletes in the blank group received no treatment, those in the control group take Xi Yang Shen （Radix Panacis Quinquefolii） orally and those in the observation group were treated by point sticking therapy. The athletes＇ RPE, hemoglobin （Hb）, red blood cell count （RBC）, blood urea nitrogen （BUN） and blood glucose （BG） were recorded every day for analysis. Results： The RPE value in the blank group tends to increase, while that in the treatment and the blank groups tend to increase first but decrease afterwards, and the corresponding RPE value in the observation group was smaller than that in the control group. After treatment, athletes in the blank group showed a decrease in Hb, RBC and BG, but an increase in BUN in the blank group; while athletes in the observation and the control groups showed increases in Hb, RBC and BG, but a decrease in BUN. Conclusion： Point sticking can alleviate clinical symptoms induced by exercise-induced fatigue.

Export Competition in China： Evidence from Data at Provincial Level

Through an analysis of the effects of Guangdong on exports from other provinces, this paper examines China＇s interregional relationships regarding exports. We utilize provincial level data from 1998 to 2008 and apply the system GMM to estimate an empirical model derived from the gravity equation. The results indicate that Guangdong significantly crowds out exports from other provinces. Coastal provinces are less affected than their non-coastal counterparts. In coastal areas, the displacement effect on the Yangtze River Delta is less than that on the Pan Bohai Rim. Further research reveals that the improvements in service industries, labor productivity, capital-labor ratio, and agglomeration of manufacturing industries have significantly reduced export competition. Additionally, a province with a larger market potential or a lower degree of market disintegration is less affected by Guangdong＇s export competition.