• Title/Summary/Keyword: postal delivery model

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A robust collision prediction and detection method based on neural network for autonomous delivery robots

  • Seonghun Seo;Hoon Jung
    • ETRI Journal
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    • v.45 no.2
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    • pp.329-337
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    • 2023
  • For safe last-mile autonomous robot delivery services in complex environments, rapid and accurate collision prediction and detection is vital. This study proposes a suitable neural network model that relies on multiple navigation sensors. A light detection and ranging technique is used to measure the relative distances to potential collision obstacles along the robot's path of motion, and an accelerometer is used to detect impacts. The proposed method tightly couples relative distance and acceleration time-series data in a complementary fashion to minimize errors. A long short-term memory, fully connected layer, and SoftMax function are integrated to train and classify the rapidly changing collision countermeasure state during robot motion. Simulation results show that the proposed method effectively performs collision prediction and detection for various obstacles.

A Study on the Shortest Path Algorithm With Direction of the Postal Route Optimization System (방향성을 고려한 우편 경로 최적화 시스템의 최단 경로 생성 알고리즘 연구)

  • Nam, Sang-U;Park, Mun-Seong
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.2
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    • pp.491-498
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    • 1997
  • Geographic Infprmation System(GIS)is being apply to extended from specified ppkication to general purpose deu to the omprovement of computing power.As one part of postal Integarated Information Servies, Postalroute Optimication system(PROS) is comprsed of the composed of the shortest pathe genrator for providing fast and shortest route of postal delivery, the ischronal area generator, the boudary relacation generator, GIS engine, road map, and rdelational database , etc.This paper is related to creation algorithm of the shortest path generation (SPAWD;Shortest Path Algorithm With Direction)from PEOS model.To differ from the exsting shortest path generating methods, this paper suggests SPAWD alforithm for searching destinations of fast time between start and destination points with dirdstion.It comapares and analyzes the new algorithm with existion algorithms, and suggests directions of future studies.

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Work performance and calling as factors influencing job satisfaction among nurse midwives working in the delivery room (분만실에 근무하는 조산사의 직무수행과 소명의식이 직무만족도에 미치는 영향)

  • Jung, Geum Ah;Kim, Moon Jeong
    • Women's Health Nursing
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    • v.26 no.1
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    • pp.10-18
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    • 2020
  • Purpose: The purpose of this study was to investigate work performance and calling as determinants of job satisfaction among nurse midwives. Methods: The participants of this study were registered nurse midwives who had worked in the delivery room for more than 6 months. Data were collected by face-to-face interviews, postal mail, and mobile devices. Subjects completed self-report questionnaires from July to August 2017. The dataset was analyzed using descriptive statistics, the independent t-test, analysis of variance, the Pearson correlation coefficient, and multiple regression. Results: The mean score for job satisfaction was 3.42±0.45. Among the sub-factors, income had the lowest score (2.67±0.72) and management of delivery had the highest score (3.81±0.66). Job satisfaction was significantly different according to marital status (t=2.25, p=.028), residential area (t=2.43, p=.016), and cause of job satisfaction (F=4.54, p=.012). Job satisfaction showed a significant positive correlation with work performance (r=.29, p<.001) and calling (r=.57, p<.001). The correlation between work performance and calling was also positive and statistically significant (r=.32, p<.001). Purpose and meaning (β=.48, p<.001) and marital status (β=-.15, p=.025) significantly influenced job satisfaction. The model developed in this study explained 45% of variation in job satisfaction. Conclusion: Nurse midwives' job satisfaction may be enhanced by entrusting them with professional roles and tasks. Above all, it is necessary to develop and provide programs that help nurse midwives connect their jobs with the meaning and purpose of their lives.

U.S. Port Investment Strategies and the Corresponding Economic Impacts Stemming from the Panama Canal Expansion

  • Park, ChangKeun
    • Asian Journal of Innovation and Policy
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    • v.10 no.2
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    • pp.195-211
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    • 2021
  • This paper measures the economic impacts of the U.S. port investment strategies coping with the Panama Canal expansion. Using secondary import data, negative and positive estimates of the impacts were presented in this study. Reduced port activities into the West Coast Customs Districts negatively affect transportation and warehousing industries, among other effects. Still, they have simultaneous positive effects in other states from increased imports resulting from modal shifts and changes in the entry port located in the South and East coasts. This study applied the supply-driven National Interstate Economic Model that measures all interstate trade among the U.S. states to divert foreign imports from 15 Pacific Rim countries. For this purpose, the following assumption was adopted: larger ships using the canal will lead to a redirection of seaborne trade among U.S. (and other) ports and result in secondary effects, e.g., using different freight modes and regional growth spillovers. This study also accounted for the entry point change and significant port investments for foreign trade under alternative scenarios. The choice of ports for international trade depends on decisions about how to minimize multimodal delivery costs. The total direct reduction of transportation and warehousing activities associated with foreign imports in the West Coast ports was estimated at $3.3 billion, leading to total negative effects of $5.8 billion. Total positive impacts from the shift of transportation modes with the choice of an entry port and new warehousing activities for foreign imports in the selected 12 states varied. As expected, states that involved an entry port had the most prominent benefits, but Texas, New York, and New Jersey may be benefited through all the port enhancement projects in the U.S. Also, except for Transportation and Postal, and Warehousing industries, Construction is another dominant positive affected industry of the Canal expansion in the U.S.