Effectiveness of the black spot programs in Western Australia

This study evaluates the effectiveness of the Black Spot Programs in Western Australia. Reduction in crash rate at the treated locations and the economic benefits of these treatments were assessed. The results showed that the programs have been effective overall, reducing all reported crash rate by 15%. The estimated crash cost savings were 50.8 million Australian dollars, of which 89% could be attributed to the reduction in casualty crashes. This led to net savings to the community of 40.4 million Australian dollars ($35.1 million attributable to casualty crashes) after subtracting the capital costs of treating sites, maintenance and operating costs. The benefit cost ratio across all treatment sites was 4.9. Evaluation of the treatments has identified some effective treatment types and others without any significant change in either the rate or cost of crashes. The latter could be due to insufficient number of sites that received the treatment, the post-treatment period being relatively short, or the treatments genuinely had little impact on road safety. Findings of this study provide objective information for the development of effective strategies on road safety investment.     

考虑多基地拖轮使用平衡性的重调度优化

目的 解决多停泊基地背景下拖轮与船舶之间供需不匹配、需求响应时效要求越来越高以及各基地拖轮使用不平衡等问题。方法 本文考虑多拖轮基地的影响，在对拖轮线路调度的基础上进行区域调度，采用对拖轮进行跨基地重调度的方法，以总调度成本最小为目标建立拖轮重调度模型。结果 将天津港数据搜集分析作为本文案例对模型进行验证分析，结果显示，采用区域调度后成本低于单纯的线路调度，且拖轮工作时间基尼系数值为0.2～0.3，处于比较公平的状态。结论 此模型有效地降低了拖轮调度成本和在港船舶等待时间，平衡了拖轮使用时间。     

Integrated scheduling of rake and stockyard management with ship berthing: a block based evolutionary algorithm

An integrated problem of optimising the operations at a commercial bulk material port terminal is studied in this paper. We simultaneously optimise the stockyard operations and rake schedule for outbound cargo, in conjunction with the arriving vessels and the status of the stockyards at the port. A mixed integer linear programming model for the problem is developed while incorporating the inherent complexities of the integrated model. To solve the real-life instances, two heuristic methods are proposed specifically for the considered problem. Firstly, genetic algorithm coupled with a greedy heuristic and later, block-based evolutionary algorithm (BBEA) is employed. After applying both techniques, we obtain the optimised schedule for loading of rakes and allotment of stockyard space for vessels as well as rakes at the terminal. Finally, we test the results of both models in three traffic scenarios between themselves and with real-life data from a port situated along the Eastern coast of India. The study resulted in significant reduction of turnaround time for rakes at the port terminal, which in turn lead to monetary savings. The model also automates the day to day operational decision-making at the port.     

Reducing injuries among Native Americans: five cost-outcome analyses

This paper presents cost-outcome analyses of five injury prevention efforts in Native American jurisdictions: a safety-belt program, a streetlight project, a livestock control project, a drowning prevention program, and a suicide prevention and intervention program. Pre- and post-intervention data were analyzed to estimate projects' impact on injury reduction. Projects' costs were amortized over the time period covered by the evaluation or over the useful life of physical capital invested. Projects' savings were calculated based on estimated reduction in medical and public program expenses, on estimated decrease in lost productivity, and on estimated quality adjusted life years saved.All projects yielded positive benefit-cost ratios. The net cost per quality adjusted life years was less than zero (i.e. the monetary savings exceeded project costs) for all but one of the projects.     

Space-time wind speed forecasting for improved power system dispatch

To support large-scale integration of wind power into electric energy systems, state-of-the-art wind speed forecasting methods should be able to provide accurate and adequate information to enable efficient, reliable, and cost-effective scheduling of wind power. Here, we incorporate space-time wind forecasts into electric power system scheduling. First, we propose a modified regime-switching, space-time wind speed forecasting model that allows the forecast regimes to vary with the dominant wind direction and with the seasons, hence avoiding a subjective choice of regimes. Then, results from the wind forecasts are incorporated into a power system economic dispatch model, the cost of which is used as a loss measure of the quality of the forecast models. This, in turn, leads to cost-effective scheduling of system-wide wind generation. Potential economic benefits arise from the system-wide generation of cost savings and from the ancillary service cost savings. We illustrate the economic benefits using a test system in the northwest region of the United States. Compared with persistence and autoregressive models, our model suggests that cost savings from integration of wind power could be on the scale of tens of millions of dollars annually in regions with high wind penetration, such as Texas and the Pacific northwest.     

A study of a two-phase inspection policy for a preparedness system with a defective state and heterogeneous lifetime

This paper considers an inspection policy for a single component protection or preparedness system, in which the component arises from a heterogeneous population. At any point in time, the system may be in one of three states, good, defective or failed. The system is only required in an emergency, and in order to ensure high availability of the system on-demand, the system undergoes a sequence of inspections. Inspection determines the system state, so that if a transition from the good state occurs between inspections it is not revealed until subsequent inspection. When a defect or failure is revealed, the component is replaced. At the final inspection the component is replaced. We suppose that a component may be either weak or strong, so that the time in the good state has a distribution that is a mixture. In these circumstances, the efficacy of a two-phase inspection policy, with an anticipated high inspection frequency in early life and low inspection frequency in later life, is considered using availability and cost criteria. The policy is investigated in the context of a valve in a natural gas supply network. If the lifetime distributions in the mixture are quite distinct, then cost savings of the order of 5% can be achieved by using the two-phase policy in place of the simpler single phase policy. Furthermore, only if the mean time in the defective state is small or the required availability is very high does the two-phase policy tend to mimic a burn-in policy.     

Techno-economic evaluation of energy efficiency measures in high rise residential buildings in Malaysia

In this paper, a survey was conducted on a residential condominium to estimate energy use by different household appliances along the lighting energy estimation in public areas. It has been found that about 2.17 GWh of energy is used in the condominium annually by different types of household appliances and lightings in public areas. As there is significant potential to reduce the energy used, different energy savings measures have been applied and energy savings, bill savings, life cycle cost analysis have been estimated and presented in this paper. It has been found that a cumulative amount of 2.4 GWh of energy can be saved for about 10 years with the implementation of different energy savings strategies proposed for appliances and lighting in public areas. However, good maintenance practices and good energy management practices should be employed continuously to maintain high energy efficiency and high performance of the equipment used and the entire building. It has been found that some of the measures like reducing air conditioning load and reducing heat gain through window tinting are economically very viable as payback period is very short. More advantageously, some of the measures can be implemented without investing significant cost. Ultimately, a key driver in the success of energy efficiency is the education and attitude of the stakeholders in the building industry, and end users who are committed to practice energy saving measures.     

玻璃瓶罐的回收与重复使用

论述玻璃瓶罐的回收和重复使用具有良好的经济效益,回收复用的处理过程也比较简单。美国定量分析了盛装饮料的玻璃瓶在生产、分配和回收复用全过程中各环节的能量消耗数据。美国纽约州在实行饮料容器押金制度后的两年中,节约了2亿美元的费用。西欧开展回收玻璃瓶罐的“绿箱子运动”效果显著。中国江苏省镇江恒顺酱醋厂1990年回收复用玻璃瓶价值94多万元,全国玻璃瓶罐回收复用和降低成本还有相当大的潜力。     

Optimal age-based inspection scheme for condition-based maintenance using A* search algorithm

In condition-based maintenance (CBM) with periodic inspection, the system is preventively replaced if failure risk, which is calculated based on the information obtained from inspection, exceeds a pre-determined threshold. The determination of optimal replacement threshold is often based on the minimisation of average maintenance costs per unit time due to preventive and failure replacements over a long time horizon. It is often assumed that inspections are performed at equal time intervals with no cost. However, in practice, inspections require labour, specific test devices, and sometimes suspension of operations and, thus, it is reasonable to inspect less frequently during the time the system is in its early age and/or in a healthier state and to perform inspections more frequently as time passes and/or as the system degrades. In other words, an age-based inspection scheme.

This paper proposes a novel two-phase approach for the determination of an optimal replacement threshold and an optimal age-based inspection scheme for CBM such that the total long-run average costs of replacements and inspections are minimised. First, it takes into account failure and preventive replacement costs to determine the optimal replacement threshold assuming that inspections are performed at equal time intervals with no cost. This assumption is, subsequently, relaxed and its consequences on total average cost are evaluated using a proposed iterative procedure based on A* search algorithm to obtain the optimal age-based inspection scheme. The proposed approach is illustrated through a numerical example.     

Solving the dynamic berth allocation problem by simulated annealing

Berth allocation, the first operation when vessels arrive at a port, is one of the major container port optimization problems. From both the port operator's and the ocean carriers’ perspective, minimization of the time a ship spends at berth is a key goal of port operations. This article focuses on two versions of the dynamic berth allocation problem (DBAP): discrete and continuous cases. The first case assigns ships to a given set of berth positions; the second one permits them to be moored anywhere along the berth. Simulated annealing (SA) approaches are proposed to solve the DBAP. The proposed SAs are tested with numerical instances for different sizes from the literature. Experimental results show that the proposed SA can obtain the optimal solutions in all instances of discrete cases and update 27 best known solutions in the continuous case.     

Developments in marine refrigeration

The expansion in the traffic of refrigerated cargo, coupled with economic pressures, has led to developments in refrigerated cargo vessels. Containerization is rapidly replacing conventional ships. The ventilation and insulation of container ships is discussed in this paper and the design of air ducts and of temperature control systems is described, as are developments in the use of pallets for packing.Changing conditions in the fishing industry have led to an increase in vessels which freeze and store fish at sea, and these freezing systems are discussed.No references are given in the paper, but a bibliography is listed at the end.     

HMMs for diagnostics and prognostics in machining processes

Despite considerable advances over the last two decades in sensing instrumentation and information technology infrastructure, monitoring and diagnostics technology has not yet found its place in health management of mainstream machinery and equipment. This is in spite of numerous studies reporting that the expected savings from widespread deployment of condition-based maintenance (CBM) technology would be in the tens of billions of dollars in many industrial sectors as well as in governmental agencies. It turns out that a prerequisite to widespread deployment of CBM technology and practice in industry is cost efficient and effective diagnostics and prognostics. This paper presents a novel method for employing hidden Markov models (HMMs) for carrying out both diagnostic as well as prognostic activities for metal cutting tools. The methods employ HMMs for modelling sensor signals emanating from the machine (or features thereof), and in turn, identify the health state of the cutting tool as well as facilitate estimation of remaining useful life. This paper also investigates some of the underlying issues of proper HMM design and training for the express purpose of effective diagnostics and prognostics. The proposed methods were validated on a physical test-bed, a vertical drilling machine. Experimental results are very promising.     

Availability and cost functions for periodically inspected preventively maintained units

Unavailability and cost rate functions are developed for components whose failures can occur randomly but they are detected only by periodic testing or inspections. If a failure occurs between consecutive inspections, the unit remains failed until the next inspection. Components are renewed by preventive maintenance periodically, or by repair or replacement after a failure, whichever occurs first (age-replacement). The model takes into account finite repair and maintenance durations as well as costs due to testing, repair, maintenance and lost production or accidents. For normally operating units the time-related penalty is loss of production. For standby safety equipment it is the expected cost of an accident that can happen when the component is down due to a dormant failure, repair or maintenance. The objective of maintenance optimization is to minimize the total cost rate by proper selection of two intervals, one for inspections and one for replacements. General conditions and techniques are developed for solving optimal test and maintenance intervals, with and without constraints on the production loss or accident rate. Insights are gained into how the optimal intervals depend on various cost parameters and reliability characteristics.     

Collaborative solutions for inter terminal transport

Major ports contain multiple container terminals, sea terminals, train, truck and barge terminal, and empty container depots, operated by different companies. Port authorities try to streamline inter terminal container transport (ITT) within congested port areas by offering expensive common road and rail infrastructure. Alternatively, individual stakeholders can set up private or collaborative container transport systems. This paper develops a framework to analyse and determine feasibility conditions of a common ITT system in a port area, depending on total transport volumes. First, we develop a simulation model to evaluate the costs of transporting containers using different modes of transport including trucks, automated guided vehicles, and multi trailer systems. Next, the required number of vehicles per mode is determined for a given throughput and waiting time. The results of the simulation are used in a game-theoretic setting to determine the cost savings per stakeholder operating in a coalition. By comparing cost savings for all possible coalitions, it is possible to determine, for each stakeholder, the attractiveness of using a common system. We find the coalitions that result in the highest savings and compare them with the infrastructure cost required to realise them. We apply the method to determine the feasibility of a common ITT system for terminals in the Port of Rotterdam and show that it only pays off in case of high demand for container transports.     

航运公司合作下的海运空箱调运模糊优化模型

目的对单独调箱与合作调箱策略进行对比分析,以期为航运公司选择最佳调箱策略提供参考。方法考虑港口空箱供需差和运力约束的模糊性,以空箱调运总成本最小为目标,建立基于航运公司合作的海运空箱调运模糊优化模型,并通过LINGO建模求解具体算例。结果与单独调箱策略相比,采用合作调运策略能够有效降低航运公司的物流总成本。其中0.32%来自存储成本的节约,54.05%来自租箱成本的节约,45.63%来自运输成本的节约。结论采用合作调箱策略,能够降低航运公司空箱调运的总成本,能够弱化单位空箱存储成本和租赁成本的增加对空箱调运总成本的影响,但单位运输成本和运费加成因子的增加会降低合作调运空箱策略的优势。     

Informing additive manufacturing technology adoption: total cost and the impact of capacity utilisation

Informing Additive Manufacturing (AM) technology adoption decisions, this paper investigates the relationship between build volume capacity utilisation and efficient technology operation in an inter-process comparison of the costs of manufacturing a complex component used in the packaging industry. Confronting the reported costs of a conventional machining and welding pathway with an estimator of the costs incurred through an AM route utilising Direct Metal Laser Sintering (DMLS), we weave together four aspects: optimised capacity utilisation, ancillary process steps, the effect of build failure and design adaptation. Recognising that AM users can fill unused machine capacity with other, potentially unrelated, geometries, we posit a characteristic of ‘fungible’ build capacity. This aspect is integrated in the cost estimation framework through computational build volume packing, drawing on a basket of sample geometries. We show that the unit cost in mixed builds at full capacity is lower than in builds limited to a single type of geometry; in our study, this results in a mean unit cost overstatement of 157%. The estimated manufacturing cost savings from AM adoption range from 36 to 46%. Additionally, we indicate that operating cost savings resulting from design adaptation are likely to far outweigh the manufacturing cost advantage.     

随机环境下班轮公司之间合作调箱研究

目的研究随机因素对2种调箱方式的影响,以体现合作调箱方式在随机环境下的优越性。方法综合考虑港口空箱需求和空箱运力限额的随机性,以决策周期内调箱总成本最小为目标,构建随机环境下班轮公司之间合作调箱模型,然后通过算例,研究不同港口服务水平和运力限制水平对2种调箱方式的影响,以及对调箱系统中随机因素进行灵敏度分析。结果当班轮公司采用保守-成本型决策、保守-服务型决策、冒险-成本型决策、冒险-服务型决策时,2种调箱方式的总成本差值分别为9638,22862,10710,19284美元。结论降低运力限制水平可以压缩调箱总成本,但是提高港口服务水平会增加调箱总成本,且当港口服务水平和运力限制水平均处于高值时,合作调箱方式的优势更加显著;与单独调箱方式相比,合作调箱方式可以降低调箱系统中随机因素波动对调箱总成本的影响。     

开辟长江口深水航道建立上海国际航运中心

开辟长江口深水航道 ,在长江口内建立国际集装箱枢纽港是建成上海国际航运中心 ,以实现以上海浦东开发开放为龙头 ,尽快把上海建成国际经济、金融、贸易中心 ,带动长江三角洲和整个长江流域地区经济新飞跃的关键举措。在长江口南支南港的北槽采用整治与疏浚相结合的治理方案 ,修建双导堤和丁坝 ,以束水归槽 ,并浚深航槽 ,可以使长江口栏门沙滩顶水深从 6m分期加深到 8 5m、 10m和 12 5m ,最终使第三、四代集装箱船可以全天候通行 ,第五、六代超级集装箱船和 10万t级散货轮乘潮进出。同时需建设长江三角洲综合交通运输网     

Ship collision risk assessment for the Singapore Strait

The Singapore Strait is considered as the bottleneck and chokepoint of the shipping routes connecting the Indian and the Pacific Ocean. Therefore, the ship collision risk assessment is of significant importance for ships passing through the narrow, shallow, and busy waterway. In this paper, three ship collision risk indices are initially proposed to quantitatively assess the ship collision risks in the Strait: index of speed dispersion, degree of acceleration and deceleration, and number of fuzzy ship domain overlaps. These three risk indices for the Singapore Strait are estimated by using the real-time ship locations and sailing speeds provide by Lloyd's MIU automatic identification system (AIS). Based on estimation of these three risk indices, it can be concluded that Legs 4W, 5W, 11E, and 12E are the most risky legs in the Strait. Therefore, the ship collision risk reduction solutions should be prioritized being implemented in these four legs. This study also finds that around 25% of the vessels sail with a speed in excess of the speed limit, which results in higher potentials of ship collision. Analysis indicates that the safety level would be significantly improved if all the vessels follow the passage guidelines.     

Optimisation of ISI interval using genetic algorithms for risk informed in-service inspection

Risk Informed In-Service Inspection (RI-ISI) aims at prioritising the components for inspection within the permissible risk level thereby avoiding unnecessary inspections. Various constraints such as risk level, radiation exposure to the workers and cost of inspections are encountered, while planning the inspection programme. This problem has been attempted to solve using genetic algorithms, which has already established its suitability in optimizing Surveillance and Maintenance activities in Nuclear Power Plants. The paper describes the application of genetic algorithm in optimizing the ISI of feeders, which are large in number and also fall in the same inspection category.