The empirical analysis of the -bilateral optimized combinatorial auction model

This study proposes a new and highly efficient dynamic combinatorial auction mechanism—the N-bilateral optimized combinatorial auction (N-BOCA). N-BOCA is a flexible iterative combinatorial auction model that offers more optimized trading for multiple suppliers and purchasers in the supply chain than one-sided combinatorial auction. We design the N-BOCA model from the perspectives of market architecture, trading rules, and decision strategy for winner determination, the decision strategy for winner determination needs flexible optimization modeling capability. Thus rule-based reasoning was applied for reflecting the flexible decision strategies. We also show the viability of N-BOCA through Paired Samples T-test experimentation. It shows that N-BOCA yields higher purchase efficiency and effectiveness than the one-auctioneer to multi-bidders (1-to-N) combinatorial auction mechanism.     

Value of Sharing Production Yield Information in a Serial Supply Chain

New developments in corporate information technology such as enterprise resource planning systems have significantly increased the flow of information among members of supply chains. However, the benefits of sharing information can vary depending on the supply chain structure and its operational characteristics. Most of the existing research has studied the impact of sharing downstream information (e.g., a manufacturer sharing information with its suppliers). We evaluate the benefits of sharing upstream yield information (e.g., a supplier sharing information with the manufacturer) in a two‐stage serial supply chain in which the supplier has multiple internal processes and is faced with uncertain output due to yield losses. We are interested in determining when the sharing of the supplier's information is most beneficial to the manufacturer. After proposing an order‐up‐to type heuristic policy, we perform a detailed computational study and observe that this information is most beneficial when the supplier's yield variance is high and when end‐customer demand variance is low. We also find that the manufacturer's backorder‐to‐holding cost ratio has little, if any, impact on the usefulness of information.     

The effects of income transfers on poverty reduction in people with disabilities in South Korea

Using a nationally representative sample dataset from the 2016 Korean Welfare Panel Study, we examined the anti‐poverty effects of income transfers in people with disabilities. Our findings indicate that in households with a person with a disability, income transfers decreased by 55.9% and 84.8% of the pre‐transfer poverty rate and poverty gap, respectively. Before income transfers, households with a person with a disability were 1.94 times more likely to be poor compared to those without a person with a disability. When income transfers were offered, the chance of being poor in the disability group was only 1.11 times higher than that in the non‐disability group. Findings from the aggregated data suggest that means‐tested income transfers were more effective in reducing poverty levels than social insurance or private income transfers. At the individual level, the provision of means‐tested programs was also more likely to decrease the likelihood of experiencing poverty than social insurance and private income transfers.     

Internet Sex Ads for MSM and Partner Selection Criteria: The Potency of Race/Ethnicity Online

The explosive growth in Internet use by men who have sex with men (MSM) to find sexual partners has been noted in the research literature. However, little attention has been given to the impact of participating in this online sexual marketplace for MSM of color, despite race and ethnicity as frequently used selection criterion in personal ads or profiles. Six focus group discussions (n = 50) and 35 in-depth qualitative interviews were conducted with African American, Latino, or Asian and Pacific Islander MSM in Los Angeles, which included discussion of their use of Internet sites to meet or interact with other MSM. Men reported race and ethnicity as a pervasive and powerful factor in facilitating or derailing Internet-mediated sexual encounters. The racialized interactions that MSM of color reported ranged from simple expressions of race-based preferences, to blatantly discriminatory or hostile interactions, and often demeaning race-based sexual objectification. Experiences of rejection and a perceived hierarchy of value in the sexual market based on race had definite costs for these MSM using these online sites. Furthermore, the private and solitary nature of seeking partners online meant that there was little to buffer the corrosive aspects of those negative experiences. These online dynamics have implications for the power balance in Internet-mediated sexual liaisons, including sexual decision making and sexual risk.     

Secondary Traumatic Stress of Service Providers who Practice with Survivors of Family or Sexual Violence: A National Survey of Social Workers

Past research demonstrates that professionals helping survivors of family violence or sexual assault are at risk of experiencing secondary traumatic stress. Although social workers frequently provide services to these families, the risk of exhibiting secondary traumatic stress symptoms has rarely been investigated. Using a national sample (N >= 154), this research project examines the prevalence and severity of secondary traumatic stress among social workers who assist survivors of family violence or sexual assault. Implications for social work practice are also discussed.     

A Multisample Confirmatory Factor Analysis of the Short Employment Hope Scale (EHS-14)

ABSTRACT.

Employment hope is an aspect of psychological self-sufficiency that captures the process of empowerment for low-income job seekers. It is posited that this process of maintaining and developing employment hope contributes to the economic self-sufficiency outcome. The preliminary 14-item 2-factor Employment Hope Scale (EHS) was previously developed using an exploratory factor analysis (Hong, Polanin, & Pigott, 2012). This study examines whether the same items could be validated using a multisample confirmatory factor analysis (CFA). Given the unsatisfied model fit of the original 2-factor model, it was modified into a 4-factor model guided by theoretical suggestion from an earlier focus-group study. The multisample CFA on the modified model explained the data significantly better than did the initial model across 2 independent samples. Reliability and validity tests confirmed the factor structure of the modified model. This study confirms that the revalidated Short EHS (EHS-14) is a more robust version of the scale. Further research is needed to demonstrate its utility as a tool to benchmark the pre-employment client empowerment process in workforce development and to monitor postemployment employee support needs in the workplace for retention.     

Voluntary and Involuntary Driving Cessation in Later Life

This study explores the decision-making process of driving cessation in later life, with a focus on voluntariness. The sample included 83 former drivers from the Baltimore Epidemiologic Catchment Area Study. A majority of participants (83%) reportedly stopped driving by their own decision. However, many voluntary driving retirees reported external factors such as financial difficulty, anxiety about driving, or lack of access to a car as main reasons for driving cessation. These findings imply that distinction between voluntary and involuntary driving cessation is ambiguous and that factors beyond health status, including financial strain, play a role in the transition to non-driving.     

Container Scheduling: Complexity and Algorithms

We consider the transport of containers through a fleet of ships. Each ship has a capacity constraint limiting the total number of containers it can carry and each ship visits a given set of ports following a predetermined route. Each container has a release date at its origination port, and a due date at its destination port. A container has a size 1 or size 2; size 1 represents a 1 TEU (20‐foot equivalent unit) and size 2 represents 2 TEUs. The delivery time of a container is defined as the time when the ship that carries the container arrives at its destination port. We consider the problem of minimizing the maximum tardiness over all containers. We consider three scenarios with regard to the routes of the ships, namely, the ships having (i) identical, (ii) nested, and (iii) arbitrary routes. For each scenario, we consider different settings for origination ports, release dates, sizes of containers, and number of ports; we determine the computational complexity of various cases. We also provide a simple heuristic for some cases, with its worst case analysis. Finally, we discuss the relationship of our problems with other scheduling problems that are known to be open.