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The shared e-scooter is a popular and user-convenient mode of transportation, owing to the free-floating manner of its service. The free-floating service has the advantage of offering pick-up and drop-off anywhere, but has the disadvantage of being unavailable at the desired time and place because it is spread across the service area. To improve the level of service, relocation strategies for shared e-scooters are needed, and it is important to predict the demand for their use within a given area. Therefore, this study aimed to develop a demand prediction model for the use of shared e-scooters. The temporal scope was selected as October 2020, when the demand for e-scooter use was the highest in 2020, and the spatial scope was selected as Seocho and Gangnam, where shared e-scooter services were first introduced and most frequently used in Seoul, Korea. The spatial unit for the analysis was set as a 200 m square grid, and the hourly demand for each grid was aggregated based on e-scooter trip data. Prior to predicting the demand, the spatial area was clustered into five communities using the community structure method. The demand prediction model was developed based on long short-term memory (LSTM) and the prediction results according to the activation function were compared. As a result, the model employing the exponential linear unit (ELU) and the hyperbolic tangent (tanh) as the activation function produced good predictions regarding peak time demands and off-peak demands, respectively. This study presents a methodology for the efficient analysis of the wider spatial area of e-scooters.

Mobility as a Service (MaaS), which integrates public and shared transportation into a single service, is drawing attention as a travel demand management strategy aimed at reducing automobile dependency and encouraging public transit. In particular, there have been few studies that recognize traffic congestion during peak hours and identify related factors for practical application. The purpose of this study is to explore what factors affect Seoul commuters’ mode choice including MaaS. A web-based survey that 161 commuters participated in was conducted to collect information about personal, household, and travel attributes, together with their mode preference for MaaS. A latent class model was developed to classify unobserved latent groups based on trip frequency by means and to identify factors influencing mode-specific utilities (in particular, MaaS service) for each class. The result shows that latent classes are divided into two groups (public transit-oriented commuters and balanced mode commuters). Most variables have significant impacts on choice for MaaS. The coefficient of MaaS choice of Class 1 and Class 2 were different. These findings suggest there is a difference between the classes according to trip frequency by means as an influencing factor in MaaS choice.

Although the influence of compact development on travel behavior has been extensively studied over the past decades, additional empirical evidence is needed to better understand that effect. This s...

The relationship between transportation and communications has been discussed throughout the past decades. This study also investigates that relationship to determine whether they are complementary or substitutive in terms of the industrial perspective, focusing mainly on six Asian countries (China, Japan, India, Korea, Indonesia, and Taiwan). National input-output (I-O) tables from the World Input-Output Database (WIOD) were used to construct research dataset. Each activity in the table was examined and fell into either transportation or communications category when they are related to those categories, thereby establishing six categories: Transportation manufacturing (TM), transportation utilities (TU), communications manufacturing (CM), communications utilities (CU), all transportation (AT), and all communications (AC). To examine the interrelationship between two sectors, direct and total coefficients were calculated for four benchmark years (2000, 2005, 2010, and 2014), then Spearman correlation analysis was conducted using those two coefficient matrices after weighting each coefficient using the economic contribution-based weight (ECBW). As a result, we confirm the predominant complementary relationship between two industries. Most Asian countries present consistent, dominant complementarity in both direct and total analysis. Although there are mixed total effects in Japan and Taiwan, the overall pattern demonstrates remarkable positive relationships. In analyzing the same effects in western countries, we also find the same straightforward positive association between two sectors, mostly in France, the US, and the UK. We believe that our findings can contribute to the literature by providing compelling evidence of the overall trend of a complementary relationship between two industries.

This study identified the factors that affect travel time budget by mode for traveler in Seoul using the SUR model. Individual, household and TAZ characteristics were selected as the explanatory variables. Transportation modes are summarized from 18 types to 6 types(walking, personal car, bus, subway, rail and bicycle). The results showed a distinct difference between personal transportation and public transportation. First of all, People who owned a car and driver`s licence tend to prefer personal transportation. In addition, we can confirm the relationship between the bus and the subway which are most typical public transportation. Passengers who can available a personal mode preferred the subway than the bus. It is expected to suggest various implications related to the public transportation policy for Seoul metropolitan area.

Ultrasmooth single-crystalline metallic thin films provide several key advantages for the fabrication of well-defined and high-resolution plasmonic nanostructures, particularly complex integrated nanocircuits. For this purpose, copper is generally regarded as a poor plasmonic material compared to gold and silver because of its notorious oxidation issues when subjected to air exposure. Here, we report on the use of large-area grain-boundary-free copper films grown epitaxially on sapphire substrates in combination with focused ion beam milling to pattern plasmonic nanostructures with superior quality. The copper surfaces prepared using a single-crystalline copper sputtering target exhibit a very low roughness without any grain boundaries for varying film thicknesses and a strong resistance to oxidation, overcoming the bottleneck in conventional copper film fabrication. Surface plasmon resonance measurements show that improved dielectric constants with higher conductivity and long-term stability can be achieved using the single-crystalline copper films. Plasmonic nanohole arrays patterned from these high-quality films are found to display a stronger field enhancement compared to those made from polycrystalline copper films, thus resulting in an enhanced extraordinary optical transmission performance. This study suggests that our fabrication method is ideally suited for applications in copper-based plasmonic and nanophotonic devices as well as integrated nanocircuits on a large scale.