The TOC-based algorithm for solving product mix problems

The five steps of the theory of constraints (TOC) emphasize exploiting constraints in order to increase the throughput of a system. The product mix decision is one application of the TOC five steps. However, these steps were considered to be implicit or incomplete, the criticism being that they result in deriving an infeasible solution when a plant has multiple resource constraints. This paper follows the essence of these five steps and presents an explicit algorithm to address the problem. When testing its effectiveness by using a dual-simplex method with bounded variables, this algorithm gives the same result in each iteration.     

Resistance and acceptance: Ambivalent attitudes toward the aging body and antiaging practices among older Korean migrants living in New Zealand

ABSTRACT

Using intersectionality as a conceptual framework, this study investigated how older Korean women living in New Zealand perceived their aging bodies, antiaging practices and/or products, and how they used such products. Thematic analysis identified three themes: tension between acceptance of the aging body as an inevitable process and transformation of the aging body into a healthy body, juggling between abstinence and use of antiaging products and practices, and redefining natural aging. The findings challenge binary interpretations between “acceptance” of and “resistance” to the experiences of the aging process and the use of antiaging practices.     

The Lesbian Internalized Homophobia Scale: a rational/theoretical approach

This article reports the development and psychometric properties of a new scale that measures internalized homophobia in lesbians: the Lesbian Internalized Homophobia Scale (LIHS). This 52-item measure was developed using a rational/theoretical approach of test construction and includes five subscales. Research findings, based on a sample of 303 female participants, supported the reliability and validity of the LIHS in assessing internalized homophobia in lesbians. Implications for research and practice are discussed.     

Between two worlds in Asia: Korean youth in Singapore

Migration within Asia has increased dramatically in recent years; however, very little is known about how Asian immigrant adolescents adapt to their new Asian environments. The present study explores the processes of acculturative stress and identity formation among Korean adolescents living in Singapore. Using focus group discussions among 17 Korean adolescents, the study finds five overarching themes on acculturative stress and identity formation: feeling superior but separated; peer pressure to keep being a Korean; less stress in speaking English; more stress in learning another language; Chinese, pride that ‘I am a Korean’, and multiculturalism. The study findings emphasize the role of context of reception as important in understanding the acculturative stress and identity development of Korean adolescents in Singapore. The implications for quantitative research are discussed.     

Multiparameter estimation in truncated power series distributions under the stein's loss

LetX ₁,…,X _p be p(≥2)independent random variables, where each X.has a distribution belonging to a one parameter truncated power series

distribution. The problem is to estimate simultaneously the unknown parameters under asymmetric loss developed by James and Stein (Proc. Fourth Berkeley Symp. Math. Statist. Prob. 1, 361-380). Several new classes of dominating estimators are obtained by solving a certain difference inequality.     

Processing Time Ambiguity and Port Competitiveness

Container seaports play an important role in cross‐border logistics as firms increasingly expand their global footprint in sourcing, manufacturing and distribution. Besides convenience of access to hinterland regions, a key metric for a port's attractiveness is its processing time, that is, its ability to clear goods within a consistent, predictable time frame. Due to differences in infrastructure, government regulations, and operating procedures, ports may exhibit different degrees of predictability in processing times: some are more predictable while others are more ambiguous. We study how ambiguity in processing times affects a port's attractiveness under various circumstances. We find that even if a port maintains a consistent expected processing time, increased ambiguity can still affect its attractiveness to firms, although not always negatively. The effect of ambiguity depends on its nature, whether the shipments are time‐sensitive, attitudes toward ambiguity, and trade terms surrounding shipments.     

Fringe Benefits and Inequality in the Labor Market

This study shows that when fringe benefits are accounted for, inequality increases at a point in time and grew faster from 1987 to 1994. Several alternative explanations of the observed discrepancies between wage inequality and compensation inequality are assessed. The evidence is that the disproportionately greater decline in income for less skilled workers is responsible for the greater decline in health insurance coverage, which in turn contributes to greater inequality growth when fringe benefits are accounted for.     

Fractional Price Matching Policies Arising from the Ocean Freight Service Industry

We consider a situation in which shippers (customers) can purchase ocean freight services either directly from a carrier (service provider)in advance or from the spot market just before the departure of an ocean liner. The price is known in the former case, while the spot price is uncertain ex‐ante in the latter case. Consequently, some shippers are reluctant to book directly from the carrier in advance unless the carrier is willing to “partially match” the realized spot price when it is lower than the regular price. This study is an initial attempt to examine if the carrier should bear some of the “price risk” by offering a “fractional” price matching contract that can be described as follows. The shipper pays the regular freight price in advance; however, the shipper will get a refund if the realized spot price is below the regular price, where the refund is a “fraction” of the difference between the regular price and the realized spot price. By modeling the dynamics between the carrier and the shippers as a sequential game, we show that the carrier can use the fractional price matching contract to generate a higher demand from the shippers compared to no price matching contract by increasing the “fraction” in equilibrium. However, as the carrier increases the “fraction,” the carrier should increase the regular price to compensate for bearing additional risk. By selecting the fractional price matching contract optimally, we show that the carrier can afford to offer this price matching mechanism without incurring revenue loss: the optimal fractional price matching contract is “revenue neutral.”