Wayne K. Talley

Stability and agreement criteria for the termination of Delphi studies

This paper addresses the question of the methodology of testing for stability between successive Delphi rounds and the necessity of doing so prior to the analysis of the level or type of consensus. Following a discussion of a hierarchical set of a criteria for determining the termination of such studies, the paper reviews some of the more common treatments of the subject in the literature. It is finally proposed that a χ2 test be used to test the stability of responses between rounds. The method is demonstrated by a numerical example.

Ocean Container Shipping: Impacts of a Technological Improvement

Through the 1950s, ocean transport of general (dry non-bulk) cargo used break-bulk (i.e., on pallet) methods: pallets were moved, generally one at a time, onto a truck or rail car that carried them from the factory or warehouse to the docks. There each pallet was unloaded and hoisted, by cargo net and crane, off the dock and onto the ship. Once the pallet was in the ships hole, it had to be positioned precisely and braced to protect it from damage during the ocean crossing. This process was then reversed at the other end of the voyage, making the ocean transport of general cargo a slow, labor-intensive, and expensive process. All of this began to change in 1955. Malcolm McLean, believing that individual pieces of cargo needed to be handled only twice-at their origin when stored in a standardized container box and at their destination when unloaded-purchased a small tanker company, renamed it Sea-Land, and adapted its ships to transport truck trailers. The first voyage, to Puerto Rico, of a Sea-Land containership began in Newark, New Jersey, USA, April 26, 1956. Confrontations with shipping lines, railroads, and unions, however, delayed the companys maiden international voyage to Rotterdam until 1966. The containerization of international trade had begun. In the years that followed, standardized containers were constructed, generally twenty or forty feet long without wheels, having locking mechanisms at each corner that could be secured to a truck chassis, a rail car, a crane, or other containers inside a ships hole or on its deck. The use of standardized containers also meant that intermodalism of international trade, the movement of cargo from an origin in one

The safety of commercial fishing: Determinants of vessel total losses and injuries

Problem: Commercial fishing is one of the least safe occupations. This study investigates determinants of vessel total losses and number of fatal and nonfatal crew injuries resulting from commercial fishing vessel accidents. Method: An injury and vessel damage accident model is developed. Total vessel loss and crew injury models are estimated using probit and negative binomial regressions, respectively, and a unique micro data set of commercial fishing vessel accidents. Results: Estimation results indicate that the probability of a total loss is the greatest for a capsizing, followed by a sinking accident. Fire/explosions and capsizings are expected to incur the greatest number of crew fatalities -- 3.5 and 3.8 for every 100 such accidents. For every 100 collisions, 2.1 nonfatal crew injuries are expected. The probability of a total loss and the expected number of crew fatalities vary inversely with the price of fish catches. Discussion: We discuss relevant issues related to fishing vessel safety management and regulation. Important vessel safety measures are summarized. Summary: Policy implications: (a) policies that reduce capsizings and sinkings will be effective in reducing fishing vessel accident total losses; (b) policies that reduce fire/explosions and capsizings (collisions) will be effective in reducing fatal (nonfatal) injuries. Impact on Industry: Policymakers should find the results of this study useful in developing regulation and enforcement mechanisms for reducing fishing vessel injuries and total losses.

Individual stability in Delphi studies

Abstract This article carries forward the work discussed in a recent article in this journal by Dajani, Sincoff, and Talley ( Technol. Forecast. Soc. Change 13, 83, 1979) by investigating individual stability as opposed to group stability for successive Delphi rounds. It is demonstrated that individual stability implies group stability but that the converse does not hold. A χ 2 test is proposed for testing the stability of individual responses between consecutive Delphi rounds. Also, an estimation procedure is presented for measuring the extent of individual stability.

OPTIMUM THROUGHPUT AND PERFORMANCE EVALUATION OF MARINE TERMINALS

This paper proposes an economic approach for determining the optimum throughput and evaluation of marine terminals in a competitive environment. The engineering approach for determining optimum terminal throughput is discussed along with theoretical and empirical engineering optimum throughputs. The economic approach is necessary in a deregulated (competitive) environment in which marine terminals have become diffused because the terminals need to concern themselves with whether they can satisfy economic efficiency objectives such as profit maximization or throughput maximization in evaluating their performance.

A model of fishing vessel accident probability

PROBLEM Commercial fishing is one of the least safe occupations. METHOD The researchers develop a fishing vessel accident probability model for fishing areas off the northeastern United States using logit regression and daily data from 1981 to 1993. RESULTS The results indicate that fishing vessel accident probability declined over the study period. Higher wind speed is associated with greater accident probability. Medium-size vessels have the highest accident probability, while small vessels have the lowest. Within the study region, accident probability is lower in the southwestern section than in the northeastern section. Accidents are likely to occur closer to shore than offshore. Accident probability is lowest in spring. IMPACT ON INDUSTRY The probability model is an important building block in development and quantitative assessment of management mechanisms related to safety in the commercial fishing industry.

The effectiveness of double hulls in reducing vessel-accident oil spillage

While much work has been done in investigating determinants of oil spillage attributed to vessel accidents, little research has been conducted on the effectiveness of ship hull design in reducing marine pollution. This paper addresses whether the double-hull requirement reduces vessel-accident oil spillage. The volume of oil spillage due to oil-cargo vessel accidents was investigated using tobit regressions and an empirical data set of individual vessel accident pollution incidents investigated by the US Coast Guard from 2001 to 2008. The results indicate that the double hull design on average reduces the size of oil spills by 20% and 62% in tank barge and tanker ship accidents, respectively.

Optimal containership size

The cost per container movement incurred by a containership per voyage leg on a given route is minimized under various scenarios. The principal conclusions reached from a comparative analysis of the optimal containership sizes are: (1) for a route of a given distance and the same time in port per port call, optimal containership size declines as the number of port calls increase, (2) for a route of a given distance and the same number of port calls, optimal containership size declines as the time in port increases and (3) for the same number of port calls and the same time in port per port call, optimal containership size increases as the distance of the route increases. Rationale for these conclusions are presented.

Determinants of the severity of passenger vessel accidents

This study investigates determinants of the number of injured, deceased and missing occupants and the damage cost of passenger vessel accidents that were investigated by the US Coast Guard for the years 1991–2001. Negative binomial and Poisson regression estimates suggest that: (1) passenger-freight combination vessel accidents incur greater injuries than other types of passenger vessels, (2) deaths are greater when precipitation weather and poor visibility exist and (3) missing occupants are greater for capsize accidents and larger the vessel. The damage cost per vessel gross ton is less for ocean cruise and steel-hulled vessels. The major conclusion of the study is that human (as opposed to environmental and vessel) causes of passenger vessel accidents result in increases in the number of injured, deceased and missing occupants.

EFFECTIVENESS AND EFFICIENCY IN TRANSIT PERFORMANCE: A THEORETICAL PERSPECTIVE

This paper presents a theoretical foundation for selecting effectiveness and efficiency performance criteria and standards by transit firms. The paper demonstrates that a transit firm must first specify its effectiveness and efficiency objectives in order to select performance criteria and standards. The paper does not actually develop standards (since they could vary from firm to firm), but does conclude that a transit firm can not be effective without being efficient; transit effectiveness and efficiency are necessary conditions for transit subsides to be effective; and public transit firms should be evaluated from the perspective of the firm rather than that of government.