The optimal fuel mix and redistribution of social surplus in the Korean power market

This paper investigates the difference between the optimal fuel mix incorporating a pre-installed generation capacity constraint and the actual fuel mix in the Korean power market. Since the restructuring of the market, the fuel mix has been determined partly by investors and partly by the Basic Plan for Long-Term Electricity Supply and Demand (BPE). Both the system marginal price (SMP), and the capacity payment (CP), which has been based on the fixed cost of a specific gas turbine generator, were intended to provide an investment incentive in the market; however, they did not bring about an optimal fuel mix in Korea. Under the circumstances of a shortage of base load generators, these generators may garner excessive profits due to a high SMP level. However, the adjustment scheme of profit between KEPCO and Gencos left scant profit for generators. This paper suggests that a contract is needed to create the appropriate profit and tax levels for these base load generators. The redistribution of profit improves equality between consumers and generators, and the proper margin creates incentives for base load technology investment in Korea.     

Sodium hypochlorite-mediated inactivation of Cronobacter spp. biofilms on conveyor belt chips

Chlorine bactericidal effects on Cronobacter vegetative cells and biofilms on conveyor belt chips were evaluated. Cronobacter vegetative cell isolates were inactivated after 10 min chlorine exposure (10 ppm). No efficacy difference was observed between pH-adjusted and pHunadjusted sodium hypochlorite solutions. The pH-adjusted solution was more effective at reducing the bacterial population in a biofilm. The number of cells in the biofilm on a Buna-N chip decreased by 3 log after exposure to 100 ppm of pH-adjusted chlorine and for PVC by 2.21 log after exposure to 400 ppm of pH-adjusted solution. The rate of biofilm reduction is dependent on the composition of the conveyor belt, concentration of chlorine, and pH of the chlorine solution.     

Automatic body landmark identification for various body figures

In this paper, we presented automatic body landmark identification algorithms that deals flexibly with the difference in body shapes and reduces the inconsistency resulting from the differences in body shapes. First, the landmark search range was defined using the statistical analysis. Next, body scan direction was identified and it was segmented. Next, automatic landmark identification algorithms were developed for each of the six landmarks and the accuracy was examined for each body shape. The scans were extracted from 5th Size Korea database. This algorithms were successfully tested on various body shapes and improved the robustness.

Relevance to industry

In automatic body measurement systems, the landmark location error occurring at nonstandard body shapes nullifies the advantage of saving time. It also makes the 3D scan measurements unreliable. The improvement of reliability and accuracy of the automatic 3D body measurement algorithm for various human body shapes will reduce the time for performing measurements and be practical for use in human-size-related production processes.     

Field-induced cathodic oxidation of low-energy Ar-ion-bombarded silicon by AFM

Local oxidation by atomic force microscopy (AFM) was studied on a 3 keV Argon (Ar)-ion-bombarded silicon (Si) (1 0 0) substrate. Giant oxide features higher than 100 nm were patterned by applying positive voltages to the tip with respect to the substrate. To analyze the growth rate of oxide features, we used the power-of-time law model. The growth rate of oxide features on an Ar-ion beam-bombarded silicon surface was increased approximately 1.8-fold compared to a common silicon surface. Furthermore, we obtained that the heights of oxide features increased as the exposure time to the tip decreased and the scan area increased.     

Using component metadata to regression test component‐based software

Increasingly, modern‐day software systems are being built by combining externally‐developed software components with application‐specific code. For such systems, existing program‐analysis‐based software engineering techniques may not directly apply, due to lack of information about components. To address this problem, the use of component metadata has been proposed. Component metadata are metadata and metamethods provided with components, that retrieve or calculate information about those components. In particular, two component‐metadata‐based approaches for regression test selection are described: one using code‐based component metadata and the other using specification‐based component metadata. The results of empirical studies that illustrate the potential of these techniques to provide savings in re‐testing effort are provided. Copyright © 2006 John Wiley & Sons, Ltd.     

Simultaneous and synergistic conversion of dyes and heavy metal ions in aqueous TiO2 suspensions under visible-light illumination

This study reports synergistic effects in the simultaneous conversion of dyes and heavy metal ions in aqueous TiO2/dye/metal ion systems (ternary components) under visible light (lambda > 420 nm). TiO2/Cr(VI)/Acid Orange 7 (AO7), TiO2/Cr(VI)/Rhodamine B (RhB), TiO2/Ag+/AO7, and TiO2/Ag+/RhB were chosen as test systems. Although dyes can be degraded in TiO2 suspensions under visible light, their removal rates were markedly enhanced in the presence of metal ions. Similarly, the reduction rates of metal ions in visible-light-illuminated TiO2 suspensions were negligible, but they were highly accelerated with dyes present. In particular, the synergistic effect in the ternary system of TiO2/Cr(VI)/AO7 was outstanding. The presence of dissolved oxygen increased the photoreduction rate of Cr(VI) despite the fact that Cr(VI) and O2 are competing electron acceptors. This is ascribed to in-situ photogenerated H2O2 from O2, which acts as a reductant of Cr(VI). RhB and Ag+ ions could be also converted simultaneously under visible light both in the presence and absence of TiO2. The visible-light-induced reduction of Ag+ did not occur at all in TiO2/Ag+ system, but it was enabled in both TiO2/Ag+/ RhB and TiO2/Ag+/AO7 to generate Ag particles. On the other hand, the binary systems of Cr(VI)/AO7, Ag+/AO7, and Ag+/RhB show significant visible-light activities for the conversion of both dye and metal ion. In this case, metal ions and dyes seem to form complexes that induce intracomplex electron transfers upon visible-light absorption. The Cr(VI)/RhB system, however, exhibited insignificant visible-light reactivity.     

Supporting Controlled Experimentation with Testing Techniques: An Infrastructure and its Potential Impact

Where the creation, understanding, and assessment of software testing and regression testing techniques are concerned, controlled experimentation is an indispensable research methodology. Obtaining the infrastructure necessary to support such experimentation, however, is difficult and expensive. As a result, progress in experimentation with testing techniques has been slow, and empirical data on the costs and effectiveness of techniques remains relatively scarce. To help address this problem, we have been designing and constructing infrastructure to support controlled experimentation with testing and regression testing techniques. This paper reports on the challenges faced by researchers experimenting with testing techniques, including those that inform the design of our infrastructure. The paper then describes the infrastructure that we are creating in response to these challenges, and that we are now making available to other researchers, and discusses the impact that this infrastructure has had and can be expected to have. Editor: Forrest Shull and Natalia Juristo     

Modern perspectives on the health benefits of kefir in next generation sequencing era: Improvement of the host gut microbiota

Kefir is a natural complex fermented milk product containing more than 50 species of probiotic bacteria and yeast, and has been demonstrated to have multiple properties conferring health benefits, including antiobesity, anti-hepatic steatosis, antioxidative, antiallergenic, antitumor, anti-inflammatory, cholesterol-lowering, constipation-alleviating, and antimicrobial properties. To better understand the underlying mechanisms of these benefits, we here review research on the effect of kefir (and kefir microorganisms) consumption to modulate the host gut microbiota. Owing to its excellent gastrointestinal resistance and colonization ability and wide ranges of microbial interaction, kefir has shown significant and wide-spectrum modulatory effects on the host gut microbiota. In particular, as a bacteria- and yeast-containing food, kefir can modulate both the gut microbiota and mycobiota. Since the association of this modulation with health benefit has only been addressed in a small number of recent studies thus far, further studies are needed to determine the precise mechanisms of the beneficial effects of kefir in relation to the modulation of the gut microbiota and mycobiota. Gaining this insight will surely help to take full advantage of this unique probiotic food.