1,286 research outputs found

    Hazardous Materials Transportation with Multiple Objectives: A Case Study in Taiwan

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    Hazardous material (hazmat) transportation has been an important issue for handling hazardous materials, such as gases and chemical liquids. In the past, researchers have made great efforts to develop policies and route planning methods for hazmat transportation problems. In 2014, Kaohsiung City in Taiwan suffered a gas pipeline explosion at midnight; 32 people were killed, and hundreds of people were injured. After the incident, policies and routing strategies for hazardous materials (hazmat) transportation in Kaohsiung were initiated to avoid pipeline transportation. Although methodologies for hazmat transportation have been proposed and implemented to minimize potential risks, multiple objectives need to be considered in the process to facilitate hazmat transportation in Taiwan. In order to consider both government and operators’ aspects, a multi-objective formulation for the hazmat problem is proposed and a compromise programming method is applied to solve the problem with two objectives: travel cost and risk. The path risk is defined based on risk assessment indexes, such as road characteristics, population distribution, link length, hazardous material characteristics, and accident rates. An aggregate risk indicator is proposed for roadway segments. The compromise programming approach is developed from the concept of compromise decision and the main idea is to search the compromise solution closest to the ideal solution. The proposed method is applied to Kaohsiung City, Taiwan. The results show that two conflicting objectives keep making trade-offs between each other until they finally reach a compromise solution

    THE EFFECT OF CHANGING-SPEED ON THE TOE HEIGHT ON TREADMILL RUNNING

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    The purpose of this investigation is to observe the differences of foot trajectory when having changing-speed running in treadmill. Subjects running on a treadmill at three different speeds and performing a dynamic data from the mark in toe box and heel counter. The result shows that with increased speed the first peak toe height just after toe-off and toe clearance (TC) increased significantly, and decreased significantly with decreased speed. The result has significant different from walking. In addition, one of four subjects has more obvious foot flat than other subjects. The reason of this phenomenon is still unclear, and we still expect that there will be more studies to establish the treadmill exercise model

    A Case Study for Exploring Dental Patients’ Preferred Roles in Taiwan

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    The purpose of this study was to explore the dental patients’ preferred roles in Taiwan. A convenience sample of 66 patients, 26 recruited from one dental clinic, and 40 from one medical center, were interviewed and their preferences for participation in treatment decision making were established using a measurement tool designed to elicit decision-making preferences. Patients’ preferences for participation in treatment decision making were established using Control Preference Scale (CPS) tool. In addition, Unfolding theory provided a means of analyzing the data so that the degree of control preferred by each patient could be established. This study found that nearly 70% clinic patients perceived passive role in treatment decision making whereas 50% patients in medical centre. Further, the collaborative role was most commonly preferred, but an active role was more commonly perceived in clinics than in medical centre. Finally, the implications of the results for patient participation are discussed

    Fast T-Type Photochromism of Colloidal Cu-Doped ZnS Nanocrystals

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    This paper reports on durable and nearly temperature-independent (at 298–328 K) T-type photochromism of colloidal Cu-doped ZnS nanocrystals (NCs). The color of Cu-doped ZnS NC powder changes from pale yellow to dark gray by UV light irradiation, and the color changes back to pale yellow on a time scale of several tens of seconds to minutes after stopping the light irradiation, while the decoloration reaction is accelerated to submillisecond in solutions. This decoloration reaction is much faster than those of conventional inorganic photochromic materials. The origin of the reversible photoinduced coloration is revealed to be a strong optical transition involving a delocalized surface hole which survives over a minute after escaping from intraparticle carrier recombination due to electron-hopping dissociation. ZnS NCs can be easily prepared in a water-mediated one-pot synthesis and are less toxic. Therefore, they are promising for large-scale photochromic applications such as windows and building materials in addition to conventional photochromic applications. Moreover, the present study demonstrates the importance of excited carrier dynamics and trap depths, resulting in coloration over minutes not only for photochromic nanomaterials but also for various advanced photofunctional materials, such as long persistent luminescent materials and photocatalytic nanomaterials

    TABLE OF CASES

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    <p>Main effects: trial: p<.001; time: p<.001; interaction: p<.001. **p<.01; ***p<0.01.</p
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