Metafrontier Production Function Analysis of Horizontal and Vertical Integration in Korea's Cable TV Industry

With its remarkable growth, the cable TV industry has witnessed increasing business integration continuously. This study categorizes technology-based operators into 3 groups on the basis of business integration—vertically integrated, horizontally integrated, and isolated system operators-and estimates the efficiency of each group. In addition, metafrontier analysis is employed to compare the efficiencies of the groups. The results suggest that vertically and horizontally integrated system operators can improve technical efficiency by accomplishing economies of scope and scale, respectively.     

Using eight trigrams (BaGua) approach with epistemological practice to vitalize problem-solving processes: A confirmatory analysis of R&D managers

Eight trigrams (BaGua) is a philosophy that has played an essential role in Chinese life. The purpose of the present study is to extend the theory to organizational problem-solving, so that individuals can engage in creative problem solving and justification to discover the most effective approaches. Questionnaires were returned by 259 research and development managers, and were analyzed using the SEM statistical method. The results indicate that the interaction among each trigram in the model of BaGua was significantly correlated. Most of the hypotheses were supported. The more an individual interacted with others, with data and with devices, the higher the problem sensitivity and evaluation performance. Despite the finding that the Tui trigram was not significantly related to the Ken trigram, all other trigram elements significantly affected each other. This finding is discussed in terms of the confirmatory situation and the conceptualization of epistemology in problem-solving.     

Does the MBA Experience Support Diversity? Demographic Effects on Program Satisfaction*

Using data provided by graduates from 128 MBA programs, we examined the extent to which age, gender, and ethnicity predicted student perceptions of the MBA experience. We found that women and minorities were more likely to see program costs and the availability of financial support as significant factors in their program enrollment decisions than were Caucasian males. The most consistent predictor of students’ perceptions of their educational experience was whether the MBA program was full time or part time, with full‐time programs generally perceived more favorably. Our findings suggest that because diversity measures of age, gender, and ethnicity were not consistent predictors across the different perception areas, at minimum, MBA programs presently do not consistently inhibit diversity. However, given the increasing percentage of women and minorities that comprise the undergraduate population, maintaining the present path in program accessibility may create enrollment problems for MBA programs perhaps in the very near future. Therefore, we conclude with a discussion of the changing demographics in higher education and their potential implications for MBA programs and suggestions for how MBA programs might respond.     

Microfluidic conformal coating of non-spherical magnetic particles

We present the conformal coating of non-spherical magnetic particles in a co-laminar flow microfluidic system. Whereas in the previous reports spherical particles had been coated with thin films that formed spheres around the particles; in this article, we show the coating of non-spherical particles with coating layers that are approximately uniform in thickness. The novelty of our work is that while liquid-liquid interfacial tension tends to minimize the surface area of interfaces—for example, to form spherical droplets that encapsulate spherical particles—in our experiments, the thin film that coats non-spherical particles has a non-minimal interfacial area. We first make bullet-shaped magnetic microparticles using a stop-flow lithography method that was previously demonstrated. We then suspend the bullet-shaped microparticles in an aqueous solution and flow the particle suspension with a co-flow of a non-aqueous mixture. A magnetic field gradient from a permanent magnet pulls the microparticles in the transverse direction to the fluid flow, until the particles reach the interface between the immiscible fluids. We observe that upon crossing the oil-water interface, the microparticles become coated by a thin film of the aqueous fluid. When we increase the two-fluid interfacial tension by reducing surfactant concentration, we observe that the particles become trapped at the interface, and we use this observation to extract an approximate magnetic susceptibility of the manufactured non-spherical microparticles. Finally, using fluorescence imaging, we confirm the uniformity of the thin film coating along the entire curved surface of the bullet-shaped particles. To the best of our knowledge, this is the first demonstration of conformal coating of non-spherical particles using microfluidics.     

Fostering High School Students’ Conceptual Understandings About Seasons: The Design of a Technology-enhanced Learning Environment

The purpose of this study is to understand in what ways a technology-enhanced learning (TEL) environment supports learning about the causes of the seasons. The environment was designed to engage students in five cognitive phases: Contextualisation, Sense making, Exploration, Modeling, and Application. Seventy-five high school students participated in this study and multiple sources of data were collected to investigate students’ conceptual understandings and the interactions between the design of the environment and students’ alternative conceptions. The findings show that the number of alternative conceptions held by students were reduced except for the incorrect concepts of “the length of sunshine” and “the distance between the sun and the earth.” The percentage of partial explanations held by students was also reduced from 60.5 to 55.3% and the percentage of students holding complete scientific explanations after using Lesson Seasons rose from 2.6 to 15.8%. While some students succeeded in modeling their science concepts closely to the expert’s concepts, some failed to do so after the invention. The unsuccessful students could not remediate their alternative conceptions without explicit guidance and scaffolding. Future research can then be focused on understanding how to provide proper scaffoldings for removing some alternative concepts which are highly resistant to change.

Factors influencing university teachers’ use of a mobile technology-enhanced teaching (MTT) platform

Educational technology research and development - The main purpose of this study was to examine the critical factors influencing university teachers’ use of a mobile technology-enhanced...     

Flow characterization of electroconvective micromixer with a nanoporous polymer membrane in-situ fabricated using a laser polymerization technique

Electroconvection is known to cause strong convective mixing in a microchannel near a nanoporous membrane or a nanochannel in contact with an electrolyte solution due to the external electric field. This study addresses micromixer behavior subject to electroconvection occurring near a nanoporous membrane in-situ fabricated by a laser polymerization technique on a microfluidic chip. We found that the micromixer behavior can be categorized into three regimes. Briefly, the weak electroconvection regime is characterized by weak mixing performance at a low applied voltage and KCl concentration, whereas the strong electroconvection regime has a high mixing performance when the applied voltage and KCl concentration are moderately high. Finally, the incomplete electroconvection regime has an incomplete electric double-layer overlap in the nanopores of the membrane when the electrolyte concentration is very high. The mixing index reached 0.92 in the strong electroconvection regime. The detailed fabrication methods for the micromixer and characterization results are discussed in this paper.     

Exploiting indoor location and mobile information for context-awareness service

Personal mobile devices such as cellular phones, smart phones and PMPs have advanced incredibly in the past decade. The mobile technologies make research on the life log and user-context awareness feasible. In other words, sensors in mobile devices can collect the variety of user’s information, and various works have been conducted using that information. Most of works used a user’s location information as the most useful clue to recognize the user context. However, the location information in the conventional works usually depends on a GPS receiver that has limited function, because it cannot localize a person in a building and thus lowers the performance of the user-context awareness. This paper develops a system to solve such problems and to infer a user’s hidden information more accurately using Bayesian network and indoor-location information. Also, this paper presents a new technique for localization in a building using a decision tree and signals for the Wireless LAN because the decision tree has many advantages which outweigh other localization techniques.     

An investigation of attitudes of students and teachers about participating in a context‐aware ubiquitous learning activity

In recent years, digital learning has been converting from e‐learning to m‐learning because of the significant growth of wireless and mobile computing technologies. Students can learn any time and any where with mobile devices. Consequently, context‐aware ubiquitous learning (u‐learning) is emerging as a new research area. It integrates wireless, mobile and context awareness technologies in order to detect the situation of the learners and provide more seamless adaptive support in the learning process. In this paper, a context‐aware u‐learning environment is developed for learning about campus vegetation in elementary schools based on an innovative approach by employing repertory grid method in designing learning content. In addition, we probe the feasibility of context‐aware u‐learning in courses by soliciting feedback from the students and teachers through interviews and questionnaires. The findings reveal that the environment is capable of enhancing students’ motivation and learning effectiveness. Moreover, it is also capable of reducing the teaching load while enabling better control of class order.     

Improving learning achievements,motivations and problem-solving skills through a peer assessment-based game development approach

In this study, a peer assessment-based game development approach is proposed for improving students’ learning achievements, motivations and problem-solving skills. An experiment has been conducted to evaluate the effectiveness of the proposed approach in a science course at an elementary school. A total of 167 sixth graders participated in the experiment, 82 of whom were assigned to the experimental group and learned with the peer assessment-based game development approach, while 85 students were in the control group and learned with the conventional game development approach. From the empirical results, it was found that the proposed approach could effectively promote students’ learning achievement, learning motivation, problem-solving skills, as well as their perceptions of the use of educational computer games. Moreover, it was found from the open-ended questions that most of the students perceived peer assessment-based game development as an effective learning strategy that helped them improve their deep learning status in terms of “in-depth thinking,” “creativity,” and “motivation.”