이경호 교수

Abstract Based on conceptual change theory, cognitive conflict is known as an important factor in conceptual change even though there are still questions about its positive and negative effects on science learning. However, there is no reliable method by which to assess the cognitive conflict students experience in their learning. The purpose of this research was to develop an instrument for measuring secondary students' cognitive conflict levels as they learned science. The results of this stud

In this note, sufficient conditions for H/sub /spl infin// output feedback stabilization of linear discrete-time systems are proposed via linear matrix inequalities (LMIs). In order to reduce conservatism existing in earlier LMI methods, auxiliary slack variables with structure are employed. It is shown that degree of freedoms by the introduction of auxiliary slack variables lead to more flexibility in obtaining an approximate solution of H/sub /spl infin// output feedback stabilization problems

A database of synthetic hurricane wind speeds is developed for a region of the southeastern United States comprising South Carolina, North Carolina, and eastern Virginia. For each zip code in the study region, the database includes a time index (year), duration of strong winds, and peak surface wind speeds (both gust and sustained). Synthetic wind speed records for 15,000years are developed using an event-based simulation approach (a modeling approach in which each hurricane is simulated as a di

Most appendiceal diverticulitis can be differentiated from usual acute appendicitis at computed tomography by visualization of the inflamed diverticulum.

Platelet- and fibrillar-structured V2O5 films have been prepared by solution methods, and their electrochemical Li+ intercalation properties have been studied. Platelet film consists of 20-30 nm sized V2O5 particles with random orientation, whereas fibrillar film is comprised of randomly oriented fibers though most of them protrude from the substrate surface. These platelet- and fibrillar-structured films exhibit relatively larger surface area and shorter diffusion path for Li+ intercalation tha

Many short antimicrobial peptides (< 18mer) have been identified for the development of therapeutic agents. However, Structure-activity relationship (SAR) studies about short antimicrobial peptides have not been extensively performed. To investigate the relationship between activity and structural parameters such as an alpha-helical structure, a net positive charge and a hydrophobicity, we synthesized and characterized diastereomers, scramble peptides and substituted peptides of the short antimi

Deletions of USP9Y have been observed among infertile males with defective spermatogenesis. Therefore, the gene has been designated as a male infertility gene on the Y chromosome. However, it remains to be determined how male infertility results from deletions of this gene. In order to initiate an investigation into the cellular functions of USP9Y in male germ cell development, in the present study we characterized the enzymatic specificity of USP9Y. Our results show that both USP9Y and Fam, the

Although it is well-known that TiO2 incorporation can greatly improve the cyclic stability of V2O5, the influences of TiO2 addition on the Li+ intercalation properties of V2O5 remain an issue of debate in literature. In this paper, we report on a systematic investigation of the preparation and intercalation properties of V2O5-TiO2 mixture films. The present work demonstrates that high Li+ intercalation rates and capacity in V2O5 films are achievable with TiO2 addition. For example, the addition