The Optimal Ordering Periods for Internet Shopping under Time Dependent Consumer Demand

This study attempts to determine the optimal goods ordering periods for internet stores by considering time-dependent consumer demands and close demand-supply interactions. In order to capture dynamic and time-sensitive consumers, the entire study period is divided into a number of ordering periods with various duration. In the demand side, the study formulates a consumer utility function to construct a binary logit model, which determines consumers’ choice probabilities between internet shopping and conventional in-store shopping. The expected choice probability of choosing internet shopping is aggregated by a transformation probability density function of individual income based on the logit model. Then, the study further aggregates individual consumer choice probability to estimate the total demand for internet stores by considering variations in access time to retail stores, and delay time of receiving ordered goods. In the supply side, the study formulates transportation costs considering extra labor cost due to 24 hours business hours of internet stores, and constructs inventory costs reflecting the relationship between the batch ordering of goods, which are made by internet store operators to their suppliers and continuous ordering of goods, which are made by their consumers. Finally, a case study and sensitivity analysis are provided by R-company in Taiwan to illustrate the application of the models. The results show how the operators of internet stores should determine the number and duration of ordering periods in response to time-dependent consumer demand, thereby maximizing their profits

Pricing and Diversification of Massive Online Open Course Platforms

Massive Open Online Courses (MOOCs) have recently received a great deal of attention in higher education. MOOCs demonstrate universities’ efforts in offering high-quality digital learning materials to everyone in the world, which should be encouraged. Nevertheless, as a MOOC platform must ensure its financial sustainability, it is questionable whether a platform’s profit-seeking pricing strategy will hurt the diversity of courses, such as eliminating courses with low certificate purchasing rates. To address this question, we adopt a game-theoretic framework to model the interaction and strategic choices of a MOOC platform, learners, and universities. Based on the certificate prices and revenue sharing ratios chosen by the platform for courses with various certificate purchasing rates, universities consider the competition intensity and decide their course quality levels, to attract learners. We conclude that all types of course will exists in equilibrium throughout the lifecycle of a MOOC platform, regardless of the technology maturity and competition intensity. We also find that course qualities may decrease when MOOCs become more accessible to learners. Finally, qualities of courses with different certificate purchasing rates are compared

Comparing How a Chatbot References User Utterances from Previous Chatting Sessions: An Investigation of Users' Privacy Concerns and Perceptions

Chatbots are capable of remembering and referencing previous conversations, but does this enhance user engagement or infringe on privacy? To explore this trade-off, we investigated the format of how a chatbot references previous conversations with a user and its effects on a user's perceptions and privacy concerns. In a three-week longitudinal between-subjects study, 169 participants talked about their dental flossing habits to a chatbot that either, (1-None): did not explicitly reference previous user utterances, (2-Verbatim): referenced previous utterances verbatim, or (3-Paraphrase): used paraphrases to reference previous utterances. Participants perceived Verbatim and Paraphrase chatbots as more intelligent and engaging. However, the Verbatim chatbot also raised privacy concerns with participants. To gain insights as to why people prefer certain conditions or had privacy concerns, we conducted semi-structured interviews with 15 participants. We discuss implications from our findings that can help designers choose an appropriate format to reference previous user utterances and inform in the design of longitudinal dialogue scripting.Comment: 10 pages, 3 figures, to be published in Proceedings of the 11th International Conference on Human-Agent Interaction (ACM HAI'23

Phylo-mLogo: an interactive and hierarchical multiple-logo visualization tool for alignment of many sequences

BACKGROUND: When aligning several hundreds or thousands of sequences, such as epidemic virus sequences or homologous/orthologous sequences of some big gene families, to reconstruct the epidemiological history or their phylogenies, how to analyze and visualize the alignment results of many sequences has become a new challenge for computational biologists. Although there are several tools available for visualization of very long sequence alignments, few of them are applicable to the alignments of many sequences. RESULTS: A multiple-logo alignment visualization tool, called Phylo-mLogo, is presented in this paper. Phylo-mLogo calculates the variabilities and homogeneities of alignment sequences by base frequencies or entropies. Different from the traditional representations of sequence logos, Phylo-mLogo not only displays the global logo patterns of the whole alignment of multiple sequences, but also demonstrates their local homologous logos for each clade hierarchically. In addition, Phylo-mLogo also allows the user to focus only on the analysis of some important, structurally or functionally constrained sites in the alignment selected by the user or by built-in automatic calculation. CONCLUSION: With Phylo-mLogo, the user can symbolically and hierarchically visualize hundreds of aligned sequences simultaneously and easily check the changes of their amino acid sites when analyzing many homologous/orthologous or influenza virus sequences. More information of Phylo-mLogo can be found at URL

On the Implications of Sense of Control over Bicycling : Design of a Physical Stamina-Aware Bike

Bicycling has become a mainstream activity among the environmental aware generation. Bicycling communities have gradually shown interests in quantitative data of the bicycling experiences such as road roughness, inclination, pollution, etc. Bikers utilize these data to infer the possible stamina cost and quality of surroundings. This supports them to make a better decision. This study assumes that fitness level indexed by stamina cost could enhance a biker's sense of control. The prototype in this paper was developed to provide stamina cost information, which is inferred from the terrain patterns of a biking route. In the system evaluation, participants took a positive attitude toward this prototype and approved the importance of stamina cost feedback. This paper also concluded several key issues about designing the stamina cost feedback system for bikers

Synthetic cell lines for recombinant AAV production

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Synthetic cell lines for recombinant AAV production

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Esophageal Food Impaction: A Homemade Suction Tube Attached to Esophagogastroduodenoscopy for Food Bolus Removal

The most common esophageal foreign body in adults is impacted food bolus. Polypectomy snares, Dormia baskets, retrieval nets, rat-tooth forceps, alligator forceps or polyp graspers are usually used to remove it. Here, we report the case of a 78-year-old woman whose esophagogastroduodenoscopy (EGD) showed a firm goose liver impacted tightly in the lower esophagus; all of the above-mentioned retrieval instruments could not remove it. We used a homemade device by attaching a modified nasogastric tube to an EGD and successfully removed the goose liver by suction under endoscopic visualization. The method is very effective to remove firm and tightly impacted materials in a narrow lumen. When the usual retrieval instruments fail, a homemade suction tube attached to an EGD is an alternative