Modeling China's offshore production sharing contracts using meta analysis

Production sharing contracts have been used in the development of China’s offshore petroleum resources since 1982, but the mechanism in which the fiscal terms impact project economics is complicated and not well understood. The purpose of this paper is to model China’s offshore production sharing contracts using a probabilistic approach. Cash flows and economic indicators are used for a typical offshore oilfield development, and meta-models are constructed to analyze the basic features of the fiscal system. Applications of the models in contract negotiation are discussed.

MODELING THE CHAIN CONFORMATION OF POLYMER MELTS IN CONTRACTION FLOW

A constitutive model of quasi-Newtonian fluid based on the type of flow is used in abrupt planar contraction now.The numerical results from finite element analysis are consistent with experimental data for stress patterns and velocityprofiles in the flow field. The chain conformations of polymer melts are then investigated in such a planar contraction byusing the phenomenological model with internal parameters proposed by the author. That is, the shape and orientation ofpolymer chain coils are predicted and discussed in different flow regions of the contraction flow field that possess simpleshear flow, extensional flow, vortical flow, and mixed flow respectively.

Improving Right Ventricle Cardiac Function for Repaired Tetralogy of Fallot Patient with Contracting Bands: A Modelling Study

Objective Patients with repaired tetralogy of Fallot(rTOF)account for the majority of cases with late onset right ventricle(RV)failure.The current surgical approach,including pulmonary valve replacement/insertion(PVR),has yielded mixed results with some patients recover RV function and some do not.An innovative surgical approach was proposed to help ventricle to contract and improve RV function qualified by ejection fraction with one or more active contracting bands.Computational biomechanical modelling is a widely used method in cardiovascular study for investigation of mechanisms governing disease development,quantitative diagnostic and treatment strategies and improving surgical designs for better outcome.Muscle active contraction caused by zero-load sarcomere shortening leads to change of zero-load configurations.In lieu of experimenting using real surgery on animal or human,computational simulations(virtual surgery)were performed to test different band combination and insertion options to identify optimal surgery design and band insertion plan.Methods Cardiac magnetic resonance(CMR)data were obtained from one rTOF patient(sex:male,age:22.5 y)before pulmonary valve replacement surgery.The patient was suffering from RV dilation and dysfunction with RV end-systole volume 254.49ml and end-diastole volume 406.91 mL.A total of 15 computational RV/LV/Patch/Band combination models based on(CMR)imaging were constructed to investigate the influence of different band insertion surgery plans.These models included 5 different band insertion models combined and 3 different band contraction ratio(10%,15%and 20%band zero-stress length reduction).These models included 5 different band insertion models:Model 1 with one band at anterior to the middle of papillary muscle;Model 2 with one band at posterior to the middle of papillary muscle;Model 3 with 2 bands which are the ones from Models 1&2 combined;Model 4 with a band at the base of the papillary muscle;Model 5 with 3 bands which is a combination of Models 3&4.A pre-shrink process was performed on in-vivo begin-filling and end-systole MRI data to obtain diastole and systole zero4oad ventricle geometries.An extra 5%-8%shrinkage was applied to obtain corresponding systole zero-load geometry reflecting myocardium sarcomere shortening.The zero-load band length in systole was 10%,15%and 20%shorter than that in diastole according to their corresponding contraction ratio.The nonlinear Mooney-Rivlin model was used to describe the ventricle material properties with their material parameter values adjusted to match measured data with CMR.The band material properties were in the same scale with healthy right ventricle.The RV/LV/Band model construction and solution procedures were the same as described.Results Model 5 with band contraction ratio of 20%has the ability to improve RV ejection fraction to 41.07%,which represented a 3.61%absolute improvement,or 9.6%relative improvement using pre-PVR ejection fraction as the baseline number.The ejection fractions for Models 1-4 with band contraction ratio of 20%were 39.28%,39.47%,38.87%and 40.34%respectively.Compared to models with band contraction ratio15%and 20%,models with band contraction ratio 10%has the least ability on RV ejection fraction improvement with ejection fraction 38.28%,38.00%,38.81%,38.50%and 39.36%corresponding to Models 1-5.Conclusions This pilot work demonstrated that the band insertion surgery may have great potential to improve post-PVR RV cardiac function for patients with repaired TOF.More band contraction ratio and inserted band number may lead to better post-surgery outcome.Further investigations using in-vitro animal experiments and final patient studies are warranted.

Influence of Building Information Modelling (BIM) on Engineering Contract Management in Nairobi, Kenya

Building Information Modelling (BIM) is a technology and a process that has brought changes in the construction’s traditional procurement system. Kenya lacks contractual guidelines on implementation of BIM;this makes the adoption of BIM slow and difficult. Previous research has identified a gap in contractual relationships, roles and resulting risks. The objectives of this study were to investigate BIM adoption in Nairobi and to investigate the influence of BIM on Engineering Contract Management (ECM) in Nairobi Kenya. The survey research was a descriptive study with 175 responsive questionnaires. Respondents comprised of Civil Engineers, Construction Project Managers, Architects, Quantity Surveyors, Contractors and Facility Managers. Data was collected through self-administered questionnaire and in-depth interview. Descriptive analytics, correlation and Exploratory factor analysis methods were used to analyse quantitative data. Qualitative data was analysed thematically. It emerged that adoption level was at 56.6% and shallow understanding of BIM capabilities remains to be a barrier to its adoption and implementation. It also emerged that BIM improves ECM;when time, cost, quality, collaboration and return on investment improve, ECM becomes easier. Latent factors found in BIM and ECM relationship were Legal Implications, awareness and knowledge, efficiency, versatility, mandate and leadership, and competitiveness. Further, the study found out that BIM influence on ECM demands for establishment of standards, guidelines, policy, legal framework, and regulations, which can be achieved by amending the public procurement act which dictates the operation of all the other standard forms of contract. Further research should be conducted to measure whether the understanding of BIM had positively improved.

A unified critical state model for geomaterials with an application to tunnelling

This paper is prepared in honour of Professor E.T.Brown for his outstanding contributions to rock mechanics and geotechnical engineering and also for his personal influence on the first author’s research career in geomechanics and geotechnical engineering.As a result,we have picked a topic that reflects two key research areas in which Professor E.T.Brown has made seminal contributions over a long and distinguished career.These two areas are concerned with the application of the critical state concept to modelling geomaterials and the analysis of underground excavation or tunnelling in geomaterials.Partially due to Professor Brown’s influence,the first author has also been conducting research in these two areas over many years.In particular,this paper aims to describe briefly the development of a unified critical state model for geomaterials together with an application to cavity contraction problems and tunnelling in soils.

Supply chain coordination mechanisms under flexible contracts

In supply chain management,an important research direction is to coordinate the supply chain through introducing flexible contracts.A supply chain contract is flexible if it can satisfy two conditions at the same time：the supply chain is coordinated,and the total profit of the supply chain can be arbitrarily divided between the supply chain members.This paper puts out two contracts,a flexible return contract and a flexible wholesale price discount contract.In contrast to many of literature,the supply chain contracts with an endogenous wholesale price is specifically considered,and a detailed sensitivity analysis of the contract parameters is given.The paper also discusses the application of the contract in vendor-managed inventory（VMI） mode.The results show that the supply chain＇s performance is improved after introducing above contracts.All the findings are illustrated by numerical examples.

An Extension of Contract Net Protocol With Real Time Constraints

The contract net protocol has developed to specify problem solving communication for nodes in a distributed problem solving. Task distribution is affected by a negotiation process,a discussion carried on between nodes with tasks to he executed and nodes that may be able to execute those tasks. In contract net protocol,once negotiation successes,tbe task execution is assumed to success. However,in real world,even though a task is awarded to successfully bidding nodes,it may be delayed. Such delay may badly propagate in whole system. Here,we introduce real-time constraints into contract net protocol to manage task execution for avoiding the, task's delay,or even though being delayed,the railure cannot propagate to whole system. In this paper,we first present a real-time contract net protocol which is an extension of contract net protocol with real-time constraints for distributed computing. Our proposition extends the basic negotiation protocol to negotiation and controlling execution or task. The controlling process is based on task deadline time,we also present an extension of the internode language of contract net protocol specification with real-time constraints.

Development characteristics, models and strategies for overseas oil and gas fields

Based on about 20 years of accumulated experience and knowledge of oil and gas field development in overseas countries and regions for China's oil companies, the development features, ideas, models and plan designing strategies of overseas oil and gas fields were comprehensively summarized. Overseas oil and gas field development has ten major features, such as non-identity project resource, diversity of contract type, complexity of cooperation model, and so on. The overseas oil and gas field development aims at the maximization of production and benefit during the limited contract period, so the overseas oil and gas field development models are established as giving priority to production by natural energy, building large-scale production capacity, putting into production as soon as possible, realizing high oil production recovery rate, and achieving rapid payback period of investment. According to the overseas contract mode, a set of strategies for overseas oil and gas field development plans were made. For tax systems contracts, the strategy is to adopt the mode of "first fat and then thinner, easier in the first and then harder", that is, early investment pace, production increase rate, development workload and production were decided by the change of tax stipulated in the contract. For production share contracts, the strategy is to give priority to high production with a few wells at a high production recovery rate to increase the cost-oil and shorten the period of payback. For technical service contracts, the strategy is that the optimal production target and workload of the project were determined by the return on investment, so as to ensure that the peak production and stable production periods meet the contract requirements.

Thick-skinned Contractional Salt Structures in the Kuqa Depression,the Northern Tarim Basin:Constraints from Physical Experiments

Thick-skinned contractional salt structures are widely developed in the western Kuqa depression, northern Tarim basin. To understand the mechanisms that govern the development of these structures, physical experiments are conducted and the results show that they are largely governed by the activities of basement faults and the forming of paleo-uplifts and basement slopes. The model materials in this study are dry sand, vaseline and plasticene （or hard foam）, simulating the suprasalt, salt, and subsalt layers respectively. The experiments show that, due to the activities of basement faults and the forming of the paleo-uplifts, salt bodies usually accumulate and thicken significantly on the middle top of the paleo-uplifts which are constrained by the pre-exiting boundary faults. The development of large-scale thrust faults and salt nappes is favored by the basement slops with larger dips. The experiments also conclude that differential structural deformation could occur between the subsalt and suprasalt layers because of the presence of salt layers. Their geometries and the locations of structural highs are different, despite of the great similarities in the uplifted areas. The pierced salt diapir is not observed in the experiments, which indicates that the contractional shortening does not effectively accelerate the development of the salt diapir.

On the Dogmatics of Contract Interpretation

The interpretation of contract has attracted much attention in the practice of contract law and the basic problems to be solved are what the parties agree on and how to set up the rules of adjudication.The present domestic studies are not conducive to contract practices because they either unnecessarily elevate scientific problems to the speculative realm of fantasy,or make the problems become more unreal and abstract.The two traditional theories of contract interpretation do not conflict in values in terms of the autonomy of the will and trust protection.However,in today' s society where cultural pluralism and legal value pluralism exist,because of different contract practices,differentiation and individualization of contract interpretation will become the basic patterns.Therefore,it is impossible and unnecessary to construct a unitary model,but it is of great significance to introduce the dogmatics-oriented contract interpretation.

Mechanical Proofs about BW Multi-Party Contract Signing Protocol

We report on the verification of a multi-party contract signing protocol described by Baum-Waidner and Waidner （BW）. Based on Paulson＇s inductive approach, we give the protocol model that includes infinitely many signatories and contract texts signing simuhaneously. We consider composite attacks of the dishonest signatory and the external intruder, formalize cryptographic primitives and protocol arithmetic including attack model, show formal description of key distribution, and prove signature key secrecy theorems and fairness property theorems of the BW protocol using the interactive theorem prover Isabelle/HOL.

Tetanic contraction induces enhancement of fatigability and sarcomeric damage in atrophic skeletal muscle and its underlying molecular mechanisms

Muscle unloading due to long-term exposure of weightlessness or simulated weightlessness causes atrophy, loss of functional capacity, impaired locomotor coordination, and decreased resistance to fatigue in the antigravity muscles of the lower limbs. Besides reducing astronauts' mobility in space and on returning to a gravity environment, the molecular mechanisms for the adaptation of skeletal muscle to unloading also play an important medical role in conditions such as disuse and paralysis. The tail-suspended rat model was used to simulate the effects of weightlessness on skeletal muscles and to induce muscle unloading in the rat hindlimb. Our series studies have shown that the maximum of twitch tension and the twitch duration decreased significantly in the atrophic soleus muscles, the maximal tension of high-frequency tetanic contraction was significantly reduced in 2-week unloaded soleus muscles, however, the fatigability of highfrequency tetanic contraction increased after one week of unloading. The maximal isometric tension of intermittent tetanic contraction at optimal stimulating frequency did not alter in 1-and 2-week unloaded soleus, but significantly decreased in 4-week unloaded soleus. The 1-week unloaded soleus, but not extensor digitorum longus(EDL), was more susceptible to fatigue during intermittent tetanic contraction than the synchronous controls. The changes in K+ channel characteristics may increase the fatigability during high-frequency tetanic contraction in atrophic soleus muscles. High fatigability of intermittent tetanic contraction may be involved in enhanced activity of sarcoplasmic reticulum Ca2+-ATPase(SERCA) and switching from slow to fast isoform of myosin heavy chain, tropomyosin, troponin I and T subunit in atrophic soleus muscles. Unloaded soleus muscle also showed a decreased protein level of neuronal nitric oxide synthase(nNOS), and the reduction in nNOS-derived NO increased frequency of calcium sparks and elevated intracellular resting Ca2+ concentration([Ca2+]i) in unloaded soleus muscles. High [Ca2+]i activated calpain-1 which induced a higher degradation of desmin. Desmin degradation may loose connections between adjacent myofibrils and further misaligned Z-disc during repeated tetanic contractions. Passive stretch in unloaded muscle could preserve the stability of sarcoplasmic reticulum Ca2+ release channels by means of keeping nNOS activity, and decrease the enhanced protein level and activity of calpain to control levels in unloaded soleus muscles. Therefore, passive stretch restored normal appearance of Z-disc and resisted in part atrophy of unloaded soleus muscles. The above results indicate that enhanced fatigability of high-frequency tetanic contraction is associated to the alteration in K+ channel characteristics, and elevated SERCA activity and slow to fast transition of myosin heavy chain(MHC) isoforms increases fatigability of intermittent tetanic contraction in atrophic soleus muscle. The sarcomeric damage induced by tetanic contraction can be retarded by stretch in atrophic soleus muscles.

基于侧链和信任管理模型的数据共享方案

为解决在不信任的区块链环境中由于数据转售而造成的用户不愿共享数据等问题,提出一种基于侧链和信任管理模型的数据共享方案。使用信任管理模型量化节点信任值,将节点信任值集成到数据共享智能合约中,为用户提供可信的共享环境和动态的访问控制接口。对联盟链进行侧链扩容,使用信任管理模型优化共识算法。规定主链使用具有拜占庭容错能力的T-PBFT算法,侧链使用仅适用于高信任场景的T-Raft算法。用户根据预先设置的阈值动态决定在主链或侧链共享数据。实验就方案的安全性和性能进行分析,表明了该方案的可行性和有效性。

论横琴粤澳深度合作区规则衔接的示范法路径:以合同法为例

从粤港澳大湾区到横琴粤澳深度合作区,在“一国两制”原则下构建统一营商环境的过程中,民商事法律制度及规则的衔接已经成为区域经济一体化发展的现实需求和必然趋势。在践行法律衔接的过程中,除了灵活使用冲突法规则、加强跨境司法合作等方式外,通过起草示范法来推进不同法域间民商事规则的趋同对国家区域法治的发展具有长远的意义。本文以合同法领域为例,通过梳理、比较及归纳内地与澳门特别行政区法律制度中的“同类项”,探索通过示范法路径实现琴澳民商事规则衔接的可能性。

Contract Types That Bring Most Value by BIM to Construction Project Involving BIM

Building information modelling(BIM),which is a new tool to manage information relating to a construction project throughout its entire life cycle,has been a hot discussion topic in the industry in recent years.With the many capabilities it can offer,some early adaptors have applied it to solve problems in various areas including utilities.From their practical experience,it is learnt that we need to change our current workflow to apply BIM before the maximum benefits can be gained.The selection of project delivery method or contract type to manage a project defines the workflow and plays an important factor to the success of BIM adoption.This paper will study the problems in applying BIM on traditional project delivery method;other new contract types available in the market;and how they can bring further value in BIM implementation with examples from different countries.

不对称信息下的提成制销售激励合同设计

代理商销售模式下,不对称信息对制造商产品定价与销售合同设计的影响越来越不容忽视。本文基于委托代理模型,分别构建了两种信息情况下提成制激励合同模型,对比分析了信息不对称下产品定价与代理商提成的关系,以及信息不对称对代理商收益、制造商利润的影响。研究发现,制造商最优定价与高需求实现概率和努力成本密切相关,当高需求市场实现概率较小且努力成本较高时,制造商将放弃对代理商的激励,并设定较低产品价格。当制造商激励代理商努力时,不对称信息有利于提高代理商期望收益,但会降低制造商期望利润,不影响价格高低。此外,不对称信息会缩小制造商可接受的努力成本区间,当代理商努力成本较大时,制造商会因薪酬支出过高而放弃对代理商的激励,而不对称信息使得代理商薪酬进一步提高,使得制造商更倾向于不激励代理商努力,相应定价也随之降低。

面向车联网的联邦学习模型定制框架及算法改进

针对车联网联邦学习服务难以满足用户训练个性化模型的需求,提出一种创新性的车联网联邦学习模型定制化服务框架。该框架采用了一种融合设备贡献度和数据集相似性的联邦学习聚合算法,实现了个性化联邦学习。该算法通过不同权重分配方式和相似性计算,使得不同用户可以根据自己的需求和数据特征,选择合适的模型训练方案。该框架还提出了一种双重抽样验证方法,解决了模型性能和可信度问题;此外,利用智能合约支持数据协作,保障了数据的安全性。实验结果表明,提出算法在大多数实验场景中表现出较高的准确率,该框架可以显著提高车联网服务的个性化水平,同时保证模型的准确性和可靠性。

不同数字技术投资模式决策及其对绿色供应链定价影响

将数字技术投资模式引入绿色供应链定价决策中,分别构建数字技术固定投资模式和边际投资模式情形下的供应链模型,研究不同数字技术投资模式对绿色供应链定价决策影响.研究发现,(1)两种模式下,制造商分别存在一个改善自身利润的数字技术投资成本阈值,存在一个数字技术投资合作区间,提出零售商收益分享+罗宾斯坦恩讨价还价模型达成供应链双赢;(2)数字技术边际投资模式下的批发价(零售价)大于数字技术固定投资模式下的批发价格,但数字技术固定投资模式下的产品绿色度比数字技术边际投资模式下大;(3)两种数字技术投资模式都能带来零售商利润的改善,且零售商利润在数字技术固定投资模式下更大.相同数字技术投资总成本下,数字技术固定投资模式更有利于提高供应链成员企业的利润.

“刚”“柔”并济的新型技术创新风控模式的构建——基于中科金财的探索性案例研究

快速变化的环境加剧了科技型企业的技术创新风险,企业需要构建兼具快变“弹性”和管控“刚性”的新型技术创新风控模式。将不完全契约理论嵌入传统风控理论,通过对中科金财独特的风控模式展开情境化研究,解锁了科技型企业构建“刚”“柔”并济风控模式的过程。具体而言,首先,企业应下沉风控单元,形成“虚拟小微企业”,加快反应速度,获取风控“弹性”,同时通过业绩认证保持必要的财务“刚性”;其次,构建“多层联盟”的风控结构,一方面通过动态调整增加结构“弹性”,另一方面则通过新规则稳固内部关系,既保证管控“刚性”,又实现对创新失败的容错“弹性”;最后,构建了“虚拟小微企业+多层联盟”的新型技术创新风控模式。基于技术创新的本质特征发展了风控理论,同时对不完全契约理论做出了一定的贡献。

考虑网络口碑的供应链定价与协调研究

随着电子商务和社交网络的迅速发展,网络口碑正在影响和改变消费者的购买习惯,并对企业决策产生重要影响。本文考虑由一个制造商和一个零售商组成的二级供应链,通过建立两阶段定价模型研究网络口碑对供应链定价和协调的影响。首先,文章分析了集中决策下网络口碑对供应链最优定价策略和整体利润的影响;其次,设计批发价契约和收益共享契约对分散决策下的供应链进行协调。研究表明:当受正面口碑影响时,系统会降低第一阶段价格,提高第二阶段价格,且口碑影响力度越大,两阶段的价格差异越小,供应链整体利润越高;当受负面口碑影响时,系统会提高第一阶段价格,降低第二阶段价格,且口碑影响力度越大,两阶段的价格差异越大,供应链整体利润越低;批发价契约无法实现供应链的协调,收益共享契约可以同时改善制造商、零售商和供应链整体利润,实现供应链协调。