Current Status and Trend of Internet and E-Commerce Market in Korea

After the remarkable increase of Internet users and broadband Internet subscribers at the end of the 20th century, the size of Korean Internet and e-commerce market steadily increased but the growth rate has been either stagnant or decreased. Trends of Korean Internet and e-commerce market are summarized in this paper the trends on Internet usage are introduced. Trends of online games, blogs and wireless Internet are introduced. The trends of Korean Internet market may have implications for China and Japan.     

The concept of directional binding energy and analysis of the phenomena involving surface and grain boundary: Part I Theory

The concept of directional binding energy (DBE) is proposed to describe the binding energy of the crystal and the ideal direction of the antiaction force against the surface tension, which derives the grain-boundary energy and also energy ratio (γ_gb/γ_s). It may provide a simple and lucid way to analyse the surface energy, grain-boundary energy and energy ratio from the correlative view point. It has been found that the grain-boundary energy can be derived only from the conceptual approach of DBE, irrespective of the dislocation model, which also makes it possible to determine the energy ratio with the misorientation angle. That is, the energy ratio (γ_gb/γ_s) is proportional to the misorientation angle, 2 sin (k′θ/2) where k′ is a constant and θ is the misorientation angle. This revised version was published online in November 2006 with corrections to the Cover Date.     

Application of Laminated Edible Films to Potato Chip Packaging

The effects of various stearic-palmitic acid blend concentrations in films, storage temperatures and storage times on potato chip quality were evaluated using Response Surface Methodology. Storage temperature and time affected the quality of potato chips. The maximum storage times for acceptable potato chip quality were: 30 to 43 days, 23 to 25 days, and 11 to 12 days for storage temperatures of 15, 25 and 35°C, respectively. Results were independent of stearic-palmitic acid blend concentrations.     

Recrystallization in Model Ice Cream Solutions as Affected by Stabilizer Concentration

Ice recrystallization rates in simple aqueous solutions comprising fructose and a hydrocolloid stabilizer were measured. The stabilizers were an enzyme-modified guar and a non-gelling high methoxy pectin. The stabilizer concentration dependence of the recrystallization rates for both materials was similar in that increasing the concentration resulted in decreasing rates until a point is reached where further addition had no additional effect. That recrystallization rates were reduced by both gelling and non-gelling stabilizers was strongly suggestive that gelation was not a requirement for recrystallization inhibition and another more specific mechanism applies, for example a weak interfacial effect such as adsorption or blocking. This behavior was also seen with locust bean gum and guar and provided further empirical evidence to support the hypothesis that stabilizers adsorb to ice crystal surfaces.     

持续审计(CA)研究综述

持续审计(Continuous Auditing,CA)是目前计算机辅助审计领域中的一个研究前沿问题.本文对CA的研究进行了分析、比较和展望.首先分析了CA的内涵.然后,对CA的相关研究进行了分类:(1)技术实现方法,分成嵌入式和分离式两种;(2)理论分析;(3)应用于CA的关键技术,并根据该分类对CA的研究分别进行了分析.最后,总结了本文的工作,并对将来CA的研究做了展望.     

Application of signal processing techniques to the detection of tip vortex cavitation noise in marine propeller

The tip vortex cavitation and its relevant noise has been the subject of extensive researches up to now. In most cases of experimental approaches, the accurate and objective decision of cavitation inception is primary, which is the main topic of this paper. Although the conventional power spectrum is normally adopted as a signal processing tool for the analysis of cavitation noise, a faithful exploration cannot be made especially for the cavitation inception. Alternatively, the periodic occurrence of bursting noise induced from tip vortex cavitation gives a diagnostic proof that the repeating frequency of the bursting contents can be exploited as an indication of the inception. This study, hence, employed the Short-Time Fourier Transform (STFT) analysis and the Detection of Envelope Modulation On Noise (DEMON) spectrum analysis, both which are appropriate for finding such a repeating frequency. Through the acoustical measurement in a water tunnel, the two signal processing techniques show a satisfactory result in detecting the inception of tip vortex cavitation.     

EXPERIMENTAL ESTIMATION OF A SCALING EXPONENT FOR TIP VORTEX CAVITATION VIA ITS INCEPTION TEST IN FULL- ANDMODEL-SHIP

Tip vortex cavitation noise of marine propeller became primary concerns to reduce hazardous environmental impacts from commercial ship or to keep the underwater surveillance of naval ships. The investigations of the tip vortex and its induced noise are normally conducted through the model test in a water cavitation tunnel. However the Reynolds number of model-test is much smaller than that of the full-scale, which subsequently results in the difference of tip vortex cavitation inception. Hence, the scaling law between model-and full-scales needs to be identified prior to the prediction and assessment of propeller noise in full scale. From previous researches, it is generally known that the incipient caivtation number of tip vortex can be represented as a power of the Reynolds number. However, the power exponent for scaling, which is the main focus of this research, has not been clearly studied yet. This paper deals with the estimation of scaling exponent based on tip vortex cavitation inception test in both full-and model-scale ships. Acoustical measurements as well as several kind of signal processing technique for an inception criterion suggest the scaling exponent as 0.30. The scaling value proposed in this study shows slight difference to the one of most recent research. Besides, extrapolation of model-ship noise measurement using the proposed one predicts the full-scale noise measurement with an acceptable discrepancy.     

Numerical Analysis of Coaxial Double Gate Schottky Barrier Carbon Nanotube Field Effect Transistors

Carbon nanotube field-effect transistors (CNTFETs) have been studied in recent years as a potential alternative to CMOS devices, because of the capability of ballistic transport. The ambipolar behavior of Schottky barrier CNTFETs limits the performance of these devices. A double gate design is proposed to suppress this behavior. In this structure the first gate located near the source contact controls carrier injection and the second gate located near the drain contact suppresses parasitic carrier injection. To avoid the ambipolar behavior it is necessary that the voltage of the second gate is higher or at least equal to the drain voltage. The behavior of these devices has been studied by solving the coupled Schrödinger-Poisson equation system. We investigated the effect of the second gate voltage on the performance of the device and finally the advantages and disadvantages of these options are discussed.     

A knowledge-based approach to safety evaluation for plant start-up

To improve the safety of plant start-up operation, a safety evaluation system has been developed. As a key component in an operational design support system, the evaluation system examines any potential hazards during start-up operation simulation. The evaluation system is integrated into an operational design methodology which designs operable processes by proposing alternatives, examining process safety and operability, and modifying operating procedures or plant structures. Issues for both methodology and implementation of a G2-based expert system are discussed. Finally, the system is applied to an industrial hydrodesulphurization process.