Early-Bird or Last-Minute? The Impact of Mobile Channel Adoption on Purchasing Behavior

With the introduction of mobile technology, user behavior has been changed. One of the most representative features of mobile channels is that it enables users to access services regardless of time and place. The mobile channel is expected to enhance the flexibility of users. We examine whether there is a difference in purchase behavior between users who adopted mobile channels and those who did not, in a context where purchase time is limited and early purchase gives potential financial merit, using a large dataset from high-speed railway service in Korea. An interesting issue is whether mobile channel makes users purchase earlier and increase the chance to get discounts. Our results using difference-in-differences estimation with propensity score matching show that people who adopted mobile channel purchase tickets later on average and at a higher price than those who did not adopt mobile channel

An Explorative Study on Sales Distribution in M-commerce

Despite the proliferation of studies on the sales distribution in e-commerce, little research has been conducted on the sales distribution in the m-commerce channel. This study empirically examines the sales distribution of various product categories in the mobile channel, using the large transaction data from a leading e-marketplace in Korea. Overall, transactions in the mobile channel are more concentrated to head products compared to the PC channel sales, but the pattern is inconsistent across product categories. Transactions in product categories of high average price (e.g., computers) and low purchase frequency rate (e.g., health care products) are less concentrated to head products in the mobile channel than the PC channel. The revenue distribution, however, shows the opposite. Head products generate relatively less revenue in the mobile channel than the PC channel. We provide explanations why the mixing results appear across product categories and between the distribution types

Are People Really Concerned About Their Privacy?: Privacy Paradox In Mobile Environment

The wide spread of mobile devices enables people to use the Internet everywhere. It provides people convenience in various aspects. However, they also are exposed to the risk of personal information leakage and privacy invasion. No previous study has examined whether the behaviors of people are influenced by their awareness of privacy in a mobile environment. With the ever-increasing importance of privacy issues, our study examines the critical relationship between individual privacy concerns and its behavior. The data is the media diary or 10,174 individuals’ media usage for three days, collected by the Korea Information Society Development Institute (KISDI) in 2014. Our result suggests that privacy concern has a positive influence on the smartphone usage, mobile application purchase and in-app purchase. It implies that the individual privacy concern does not correspond to his or her actual behaviors, which is paradoxical

Built Environment and Outdoor Leisure Activity under the Individual Time Budgets

Previous studies highlight the role of walkable neighborhoods in improving the health status of residents, hypothesizing that there is a strong relationship between the built environment and individual physical activity. However, unlike theoretical prediction, the evidence is less established that residents in inner cities engage in more physical activity than residents in suburban areas. To address this gap between theoretical prediction and empirical evidence in physical activity studies, this paper investigates the links between the built environment and outdoor leisure activities under the individual time constraint. We conducted path analysis, employing the samples of Los Angeles County in NHTS (National Household Travel Survey, 2008–2009). Empirical results revealed that individual time constraints have a significant negative effect on leisure time spent in outdoors, but the influence was marginal. Surprisingly, the access to local resource (e.g., park area) still matters even after time constraints are controlled for. Regarding the effects of other covariates, safety (perceived), attitude, and disability showed the largest association with outdoor leisure activities amongst the independent variables with the expected sign. Based on these results, this study not only confirms that the lack of time plays a role as a barrier of the outdoor leisure activity, but also proves that park area can be considered as a facilitator. However, the behavioral decision for outdoor leisure activities is about more than time constraints and the built environment since the effects of both are much smaller than other key covariates

The Contribution of Neighborhood Tree and Greenspace to Asthma Emergency Room Visits: An Application of Advanced Spatial Data in Los Angeles County

This paper aims to investigate the role of neighborhood tree and greenspace on asthma morbidity, especially asthma emergency room visits. We employed advanced spatial data which allow for precisely capturing both the quantity and the features of tree and greenspace within a neighborhood environment. The results from the spatial regression models in Los Angeles County revealed that the features of trees and greenspace, such as the configuration of the tree canopy, the level of tree clustering, and private neighborhood greenspaces contribute to decreasing asthma morbidity, in addition to the quantity of tree and greenspace acreages. Notably, however, large scale greenspace, such as golf courses, school playgrounds, and parks fails to reduce the number of asthma emergency room visits at the statistically significant level. These findings imply that the creation of dense or clustered tree patches and small-scale neighborhood greenspaces might play a substantial role in mitigating air quality and consequently reducing asthma emergency room visits

Built Environment and Outdoor Leisure Activity under the Individual Time Budgets

Previous studies highlight the role of walkable neighborhoods in improving the health status of residents, hypothesizing that there is a strong relationship between the built environment and individual physical activity. However, unlike theoretical prediction, the evidence is less established that residents in inner cities engage in more physical activity than residents in suburban areas. To address this gap between theoretical prediction and empirical evidence in physical activity studies, this paper investigates the links between the built environment and outdoor leisure activities under the individual time constraint. We conducted path analysis, employing the samples of Los Angeles County in NHTS (National Household Travel Survey, 2008–2009). Empirical results revealed that individual time constraints have a significant negative effect on leisure time spent in outdoors, but the influence was marginal. Surprisingly, the access to local resource (e.g., park area) still matters even after time constraints are controlled for. Regarding the effects of other covariates, safety (perceived), attitude, and disability showed the largest association with outdoor leisure activities amongst the independent variables with the expected sign. Based on these results, this study not only confirms that the lack of time plays a role as a barrier of the outdoor leisure activity, but also proves that park area can be considered as a facilitator. However, the behavioral decision for outdoor leisure activities is about more than time constraints and the built environment since the effects of both are much smaller than other key covariates

Prediction Models Based on Regression and Artificial Neural Network for Moduli of Layers Constituted by Open-Graded Aggregates

The impermeable cover in urban area has been growing due to rapid urbanization, which prevents stormwater from being naturally infiltrated into the ground. There is a higher chance of flooding in urban area covered with conventional concretes and asphalts. The permeable pavement is one of Low-Impact Development (LID) technologies that can reduce surface runoff and water pollution by allowing stormwater into pavement systems. Unlike traditional pavements, permeable pavement bases employ open-graded aggregates (OGAs) with highly uniform particle sizes. There is very little information on the engineering properties of compacted OGAs. In this study, the moduli of open-graded aggregates under various compaction energies are investigated based on the Plate Load Test (PLT) and Light-Weight Deflectometer (LWD). Artificial Neural Network (ANN) and Linear Regression (LR) models are employed for estimation of the moduli of the aggregates based on the material type and level of compaction. Overall, the moduli from PLT and LWD steeply increase until the number of roller passes reaches 4, and they gradually increase until the number of roller passes becomes 8. A set of simple linear equations are proposed to evaluate the moduli of open-graded aggregates from PLT and LWD based on the material type and the number of roller passes

Compaction Quality Monitoring of Open-Graded Aggregates by Light Weight Deflectometer and Soil Stiffness Gauge

Open-graded aggregates (OGAs) are free-draining materials often used as the base layer of permeable pavements to allow the infiltration or drainage of stormwater. Despite their widespread use, the compaction quality of OGA base layers has not been specified properly. The currently used density-based compaction quality control (QC) has limitations; obtaining the field density and maximum dry density of OGAs by typical methods is challenging, due to their unique properties. To overcome these limitations, modulus-based compaction QC can be used as an alternative. In this study, five different OGAs were chosen and compacted into a specially built soil chamber to measure their densities. The light weight deflectometer (LWD) and the soil stiffness gauge (SSG) were used to evaluate the modulus of the compacted OGAs. The vibratory hammer compaction test was conducted to obtain the maximum dry density of the aggregates. Through these tests, the relationship between the modulus of the compacted aggregates and the relative density was obtained, and efforts to find a modulus range that ensures proper compaction were made. It was found that the LWD and SSG are valid and reliable devices for monitoring the modulus change of OGAs due to compaction