Autonomy, bureaucracy, professionalism and accountability: a transaction cost approach to shipboard controls

In recent years, shipping industry has encountered severe competition, technological change, and environmental and safety concerns. In order to remain competitive, firms need to review and redesign shipboard work. A crucial aspect of these efforts is shipboard controls that define the extent of autonomy and accountability of officers and crew. This study examines four types of controls on board ships. These are monitoring and autonomy, outcome accountability, formalization and professionalization. The study applied trancsaction cost theory to test eight hypotheses on board 16 ships in two companies. The results largely confirm theoretical predictions. Task visibility, complexity and uncertainty show strong relationships to the four types of controls. However, there are also significant gaps in that accountability for outcomes is low, and situation with regard to crew training and autonomy can be improved. Implications for human resource practice and future research are discussed.     

Dissolved organic matter studies in enclosed systems: Application of Hydrophobic fractionation for the assessment of organic nitrogen dynamics

The evolution of dissolved organic matter (DOM) in a non-axenic batch culture of the marine diatom Thalassiosira tumida was studied by hydrophobic fractionation during a three month experiment. DOM was fractionated with XAD-2 resin into hydrophobic (acid and neutral, “humic”) and hydrophilic fractions. The combined amino acid contents of unfractionated filtered seawater, XAD-fractions and particulate material were determined during the growth, stationary and degradation phases of the culture, and variations related to changes in dissolved organic nitrogen (DON) in XAD-fractions, dissolved inorganic nitrogen, algal and bacterial biomass. XAD-fractionation enabled the discrimination of simultaneously ocurring release and uptake of organic nitrogenous compounds: During the diatom growth there was a net increase of tolal DON concentrations, which was mostly accounted for by the hydrophilic fraction. A concurrent heterotrophic uptake of combined amino acids and other non-amino acid organic nitrogen was discernible by the decrease of their concentrations in the hydrophobic fractions. In the stationary phase, during the prevailing net consumption of total DON, the production of algal exudates could be detected in the hydrophobic fractions, while uptake mainly involved non-amino acid organic nitrogen from the hydrophilic fraction. During the degradation phase, after two months part of the particulate amino acid pool was transformed into hydrophilic DON, which in contrast to the stationary phase, was not adequate for supporting sustained bacterial growth. This suggests that the generation of recalcitrant substances may begin in the hydrophilic fraction of DOM. A slight increase of the hydrophobic acid fraction was indicative of the incipient formation of humic substances. XAD-2 was able to adsorb substances from fast changing DOM pools and thus should be a useful tool in studies concerned with phytoplankton and bacterial dynamics.     

用多层次多目标决策法进行施组设计方案选优

通过对影响铁路施工组织方案因素的分析,介绍了应用多层次多目标决策方法进行铁路施工组织设计方案选优的步骤和内容,并给出了相应的算法.     

铁路车辆红外线二代机轴温探照角度的设置

红外线二代机轴温探测系统投入使用以来，为防止铁路车辆燃切轴，确保列车运输安全、畅通发挥了巨大作用。随着当前列车不断提速和铁路跨越式发展的新形势，红外线轴温探测在保障铁路运输安全生产中的作用更为重要。但是近几年哈尔滨、沈阳、南昌等铁路局相继发生车辆热切轴事故，而这些切轴无一不是经过红外线探测网络探测过的车辆．抛开人为不负责任违章造成的事故以外，有些热切轴车辆在通过红外探测站的时候并没有发现过高的温升，那么是车轴的温度真的不高，还是红外设备不灵呢?     

Maritime safety: To be or not to be proactive

The purpose of this paper is to address important issues regarding policy formulation in the maritime safety area. The main thesis of the paper is that there is some way to achieve a truly proactive maritime safety regime, and there even seems to be recent progress toward this end. A qualitative assessment on the nature of maritime safety policies and on the way that these are put forward is attempted, along with some opinions on the possible pitfalls and on what needs to be done so that this process can be further improved.     

基于振动成型法的半刚性基层配合比设计和施工技术探讨

水泥稳定碎石基层配合比设计中确定压实度控制参数的传统方法是重型击实法,与实际施工的振动碾压方法有明显不同.而采用振动成型法则与实际施工碾压方式更为接近.依托韶赣高速公路B01标路面工程对半刚性基层振动成型法配合比设计及施工技术进行分析,为该方法的推广使用提供技术参考.     

Seabirds utilizing the Northeast Water polynya

A small seabird community depends on the resources of the Northeast Water (NEW) polynya. In spring, at least 1000 King Eiders and 2500 Common Eiders form pre-breeding congregations at Ob Bank before dispersing in mid June to breeding areas. The most abundant species is the Fulmar, which breeds in six colonies with a total of 2550 “apparently occupied sites”, corresponding to approx. 1475 active pairs in 1993. Kittiwakes occupied almost 900 sites at Mallemukfjeld, with an estimated 733 breeding pairs. The entire NEW area probably holds 400–500 pairs of Ivory Gulls, and about 500 individuals were associated with a colony on Henrik Krøyer Holme; this is one of the world's largest known colonies. Sabine's Gulls breed at the same islands and on Kilen (approx. 50 pairs in each place). Small colonies (total less than 1000 birds) of Arctic Terns are distributed along the edge of the polynya, with the largest colony of about 100 pairs on Henrik Krøyer Holme. The Black Guillemot is the only breeding auk species (< 20 pairs) in the area. Small numbers of Red Phalaropes were observed in the polynya in 1992 and 1993, and the species may have bred at Henrik Krøyer Holme in 1993; the polynya area may also serve as a staging area for transpolar migrants. In late summer a few hundreds of Ross's Gull—non-breeding adults and immatures—show up in and around the polynya, and in recent years a few cases of breeding have also been recorded. The relatively small seabird populations are evidence of a generally low carrying capacity of the polynya area.Apart from the benthic foraging eiders and the Black Guillemot, the seabird community of NEW consists of surface feeders—Fulmars and gulls—dependent on small fish and zooplankton. During their stay in the NEW area, the five most abundant surface feeders will annually consume approximately 243,000 kg (wet weight) of food, of which the Fulmars alone take 67%. Food demand in relation to area of open water in the polynya is highest in spring (approx. 0.2 kg/km²), which is     

Accurate INS position solution during GPS outages or degraded GPS

Temporary degraded GPS (DGPS) position loss, in circumstances such as an overhead bridge, can be alleviated by an inertial navigation system (INS) that uses onboard sensors, such as yaw and speed sensors, to determine vehicle position. This paper introduces a post-processing DGPS/INS integration approach based on using the INS solution during DGPS outages or periods of low accuracy DGPS position solutions. In this approach, the INS solution initialization is performed using the DGPS solution before DGPS position solution loss, and measurements from the Inertial Measurement Unit (IMU). The final post-processed INS solution is a weighted average of the INS forward and backward solutions. This work constitutes two parts: the INS initialization methods for different degrees of freedom vehicle positioning models, and the developed weighting model necessary to combine the forward and the backward solutions. The former part is essential in obtaining acceptable INS initial states for both the stand-alone INS or any post-processing or real time INS/GPS integrated system. The latter part is based on the use of the complementary error behaviours of the backward and the forward solutions, and can be used as a survey method with acceptable position solutions accuracies. Applying the forward/backward INS combined solution method on real data shows that the resultant INS solution accuracy is 35 cm or less over a 1000 m road segment. This method is used to survey freeways interchange road segments where 50% of the surveyed distance has no DGPS solution or has a degraded DGPS solution. The average achieved accuracy over the whole freeways interchange is around 40 cm over a 23 km distance.     

Late-Quaternary changes in productivity of the Southern Ocean

Paleoceanographic records based on new proxies of export production have been constructed for the South Atlantic sector of the Southern Ocean. A radionuclide-ratio proxy of particle flux (¹⁰Be/²³⁰Th) and the accumulation rate of authigenic uranium, which responds to the flux of organic carbon to the sea bed, both indicate a dramatic increase, compared to the present, in the export production of the Subantarctic zone (approximately the region between the present-day positions of the Subtropical Convergence and the Antarctic Polar Front) during glacial periods. If the South Atlantic is representative of the entire Southern Ocean, then export production in the Southern Ocean during the Last Glacial Maximum was substantially greater than at present. Previous studies, focusing on the burial of biogenic opal, failed to recognize the glacial increase in export production of the Southern Ocean because of a strong non-linearity between accumulation rates of opal and of organic carbon.     

基于节气门位置传感器的发动机故障诊断研究

通过在VOLVOB230F型电控汽油喷射发动机上研究节气门位置传感器的全负荷信号对发动机性能的影响．并对节气门位置传感器故障造成的发动机性能变化的对比可分析表明：节气门位置传感器的全负荷信号丢失以后，混合气变稀，功率下降；CO和HC排放降低，NOx排放升高，同时有助于指出了节气门位置传感器在电控发动机故障诊断中的作用。