• Education of Primary School Mathematics
• /
• v.21 no.4
• /
• pp.431-444
• /
• 2018

The purpose of this study was to develop and validate a mathematics anxiety scale for elementary students in South Korea. Based on the literature review, I developed two types of survey items measuring elementary students' mathematics anxiety. Teachers or students may use survey measurements selectively according to the students' participants in mathematics private institutions. In order to assess the reliability and validity of survey items, I conducted surveys with elementary students. The sample consisted of 300 elementary students in public elementary schools in Seoul. A total of 28 items were developed and examined for the internal consistence. The results showed that the proposed scale was appropriate to represent the mathematics anxiety of elementary students. The survey items of this study could be applied for assessing elementary students' mathematics anxiety regardless of their gender and age factors.

• Korean journal of food and cookery science
• /
• v.10 no.3
• /
• pp.254-259
• /
• 1994

Meat provides high quality proteins, lipids, minerals and vitamins. The meat protein is especially high in essential amino acids that are crucial for human health, growth & development and for the formation of enzymes, hormones and antibodies. Relatively cheap and nutritionally sound vegetable proteins that are similar to animal proteins are being developed to replace the animal proteins in texture, nutrition and food characteristics. In this study a nutritionally sound meat lipid replacing food Oatrim that has been produced by converting oat starch into maltodextrin by ${\alpha}$-amylase, have been partially substituted for beef and general component analysis, texture measurement and sensory tests have been conducted. The results are 1. Water content of the non-treated (0% treated) was 67.1% and the treated (10% treated) was 77%. The treated showed better water holding capacity. 2. Protein content of the non-treated was 21.2 g/100 g; the 4% treated, 18.4 g/100 g; the 6% treated, 18.2 g/100 g; the 8% treated, 17.2 g/100g; and the 10% treated, 16.0 g/100 g. The protein content tended significant. 3. Amino acid analysis results showed that glutamic acid content was the highest in Oatrim and as its amino acid make up is exellent, it is valuable as a fine low fat protein food. 4. Sensory tests show that the increased Oatrim content increased the appearance quality but food characteristics were high only in the 4% and 6% treated groups, indicating that the replacement ratio should not exceed 10%. 5. Texture measurement analysis results show that the higher the replacement content, lower the springness, cohesiveness, hardness, chewiness and gumminess, resulting in relatively soft overall texture. However, in order to better the food characteristics, more studies must be continuously done, and so by being able to increase vegetable substitution over meat, it may be able to contribute to the prevention of adult disease.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.11
• /
• pp.4483-4488
• /
• 2010

In comparison with some other light sources, LED has merits such as long lifetime, pollution free, and high energy efficiency. Lately, due to development of LED with high brightness and capacity, LED, which has been applied in display system only, has applied in the field of lighting system. Driving current of power LED has to be controlled below the designed value. In this paper, half-bridge LLC series resonant converter, which has the current limiting function, has been described. Half-bridge LLC series resonant converter allows in relatively wide input voltage and output load range when compared to the other resonant converter. Also, it is possible to reduce a magnetic component, because leakage inductance of transformer is used as a resonant inductance. It has been validated by designing and testing 200[W] half-bridge LLC converter of DC24[V] output voltage for LED lamp driver, which includes a current limiting function and power factor correction(PFC) function.

• Journal of KIISE:Software and Applications
• /
• v.32 no.9
• /
• pp.835-846
• /
• 2005

A Product Line (PL) is a set of products (applications) that share common assets in a domain. Product Line Engineering (PLE) is a set of principles, techniques, mechanisms, and processes that enables the instantiation of produce lines. Core assets, the common assets, are created and instantiated to make products in PLE. Model Driven Architecture (MDA) is a new software development paradigm that emphasizes its feasibility with automatically developing product. Therefore, we can get advantages of both of the two paradigms, PLE and MDA, if core assets are represented as PIM in MDA with predefined automatic mechanism. PLE framework in the PIM level has to be interpreted by MDA tools. However, we do not have a standard UML profile for representing core assets. The research about representing PLE framework is not enough to make automatically core assets and products. We represent core asset in PIM level in terms of structural view and semantic view. We also suggest a method for representing architecture, component, workflow, algorithm, and decision model. The method of representing framework with PLE and MDA is used to improve productivity, applicability, maintainability and qualify of product.

• Journal of the Korean Applied Science and Technology
• /
• v.31 no.3
• /
• pp.367-374
• /
• 2014

In this study, skin permeation enhancement was confirmed by designing it to have a structure and composition similarity to the intercellular lipids that improve miscibility with skin by cross-linked lipids poloxamer. The cross-linked lipids poloxamer was synthesized and analyzed by 1H NMR that structure dose had conjugated pluronic with ceramide3. Active component is released by modification of liquid crystal structure because PPO part, large-scale molecule block of pluronic, has hydrophobic nature at skin temperature of $35^{\circ}C$. Conjugated pluronic with ceramide3 was synthesized using Pluronic F127 and p-NPC (4-nitrophenyl chloroformate) at room temperature yielded 89%. Pluronic(Ceramide 3-conjugated Pluronic) was synthesized by reaction of p-NP-Pluronic with Ceramide3 and DMAP. The yield was 51%. This cross-linked lipids poloxamer was blended and dissolved at isotropic state with skin surface lipids, phospholipid, ceramide, cholesterol and anhydrous additive solvent. Next step was preceded by ${\alpha}$-Transition at low temperature for making the structure of Meso-Phase Lamella, and non-hydrous skin analogue liquid crystal using thermo-sensitivity smart sensor, lamellar liquid crystal structure through aging time. For confirmation of conjugation thermo-sensitivity smart sensor and non-hydrous skin analogue liquid crystal, structural observation and stability test were performed using XRD(Xray Diffraction), DSC(Differential Scanning Calorimetry), PM (Polarized Microscope) And C-SEM (Cryo-Scanning Electron Microscope). Thermo-sensitivity observation by Franz cell revealed that synthesized smart sensor shown skin permeation effect over 75% than normal liquid crystal. Furthermore, normal non-hydrous skin analogue liquid crystal that not applied smart sensor shown similar results below $35^{\circ}C$ of skin temperature, but its effects has increased more than 30% above $35^{\circ}C$.

• Journal of Ocean Engineering and Technology
• /
• v.21 no.6
• /
• pp.7-15
• /
• 2007

A mechanical model was developed to predict the behavior of point-loaded RC slender beams (a/d > 2.5) without stirrups. It is commonly accepted by most researchers that a diagonal tension crack plays a predominant role in the failure mode of these beams, but the failure mechanism of these members is still debatable. In this paper, it was assumed that diagonal tension failure was triggered by the concrete cover splitting due to the dowel action at the initial location of diagonal tension cracks, which propagate from flexural cracks. When concrete cover splitting occurred, the shape of a diagonal tension crack was simultaneously developed, which can be determined from the principal tensile stress trajectory. This fictitious crack rotates onto the crack tip with load increase. During the rotation, all forces acting on the crack (i.e, dowel force of longitudinal bars, vertical component of concrete tensile force, shear force by aggregate interlock, shear force in compression zone) were calculated by considering the kinematical conditions such as crack width or sliding. These forces except for the shear force in the compression zone were uncoupled with respect to crack width and sliding by the proposed constitutive relations for friction along the crack. Uncoupling the shear forces along the crack was aimed at distinguishing each force from the total shear force and clarifying the failure mechanism of RC slender beams without stirrups. In addition, a proposed method deriving the dowel force of longitudinal bars made it possible to predict the secondary shear failure. The proposed model can be used to predict not only the entire behavior of point-loaded RC slender shear beams, but also the ultimate shear strength. The experiments used to validate the proposed model are reported in a companion paper.

• Journal of the Korean Wood Science and Technology
• /
• v.46 no.3
• /
• pp.253-259
• /
• 2018

To determine the depth of preservative penetration in ACQ treated wood, the degree of penetration of Cu was measured. In this study, we developed a DDAC coloring method to investigate the penetration depth of DDAC, which is one of the active ingredient of ACQ, into wood. The following conclusions were obtained. The DDAC component reacts with a 2', 7'-dichlorofluorescein indicator and results in a deep orange color. This orange coloring reaction appears not only in DDAC solutions but also in ACQ treated wood tissues in which DDAC is present. It is possible to visually verify that DDAC has better wood penetration than Cu in the spruce, which is an refractory wood species, by the DDAC coloring method developed this study. In addition to the results, it is necessary to investigate the difference in penetration of Cu and DDAC for other wood species with poor preservative penetration.

• Annals of Clinical Microbiology
• /
• v.21 no.4
• /
• pp.69-74
• /
• 2018

Laboratory medicine is a specialized division that supports physicians in the care of patients by providing rapid and accurate in vitro diagnostic tests. Standardization of every component of a specific test is essential for producing accurate results. The Clinical and Laboratory Standards Institute (CLSI) was founded to develop a formal consensus process for standardization in 1968, and has been publishing standards and guidelines covering all aspects of clinical, research, and other laboratory work. CLSI guidelines are widely used around the world for standardization. The CLSI antimicrobial susceptibility testing subcommittee (AST SC) consists of 6 standing and many ad hoc working groups. Members of the AST SC review submitted proposals and suggestions, decide on approving these submissions in face-to-face meetings held twice a year, and revise CLSI documents accordingly. As these face-to-face meetings are open to anyone who registers to attend, I strongly encourage the members of our Society to attend and actively participate in document development.

• Korean Journal of Remote Sensing
• /
• v.21 no.1
• /
• pp.91-98
• /
• 2005

On board satellite magnetometer measures all possible magnetic components, such as the core and crustal components from the inner Earth, and magnetospheric, ionospheric and' its coupled components from the outer Earth. Due to its dipole and non-dipole features, separation of the respective component from the measurements is most difficult unless the comprehensive knowledge of each field characteristics and the consequent modeling methods are solidly constructed. Especially, regional long wavelength magnetic signals of the crust are strongly masked by the main field and dynamic external field and hence difficult to isolate in the satellite measurements. In particular, the un-modeled effects of the strong auroral external fields and the complicated behavior of the core field near the geomagnetic poles conspire to greatly reduce the crustal magnetic signal-to-noise ratio in the polar region relative to the rest of the Earth. We can, however, use spectral correlation theory to filter the static lithospheric and core field components from the dynamic external field effects that are closely related to the geomagnetic storms affecting ionospheric current disturbances. To help isolate regional lithospheric anomalies from core field components, the correlations between CHAMP magnetic anomalies and the pseudo-magnetic effects inferred from satellite gravity-derived crustal thickness variations can also be exploited, Isolation of long wavelengths resulted from the respective source is the key to understand and improve the models of the external magnetic components as well as of the lower crustal structures. We expect to model the external field variations that might also be affected by a sudden upheaval like tsunami by using our algorithm after isolating any internal field components.

• Bulletin of the Korean Chemical Society
• /
• v.17 no.7
• /
• pp.637-642
• /
• 1996

Preparation and properties of potential CVD (Chemical Vapor Deposition) precursors for the TiO2, a major component of the perovskite materials such as PT, PLT, PZT, and PLZT were investigated. Reactions between β-diketones and TiMe3, formed in situ failed to produce stable Ti(β-diketonate)3 complexes but a stable purple solid, characterized as (OTi(BPP)2)2 (BPP=1,3-biphenyl-1,3-propanedione) was obtained when BPP was used. Several new Ti(Oi-Pr)2(β-diketonate)2 complexes with aromatic or ring substituents were synthesized by the substitution reaction of Ti(OiPr)4by β-diketones and characterized with 1H NMR, IR, ICP, and TGA. Solid complexes such as Ti(Oi-Pr)2(BAC)2 (BAC=1.-phenyl-2,4-pentanedione), Ti(Oi-Pr)2(BPP)2, Ti(Oi-Pr)2(1-HAN)2 (1-HAN=2-hydroxy-1-acetonaphthone), Ti(Oi-Pr)2(2-HAN)2 (2-HAN=1-hydroxy-2-acetonaphthone), Ti(Oi-Pr)2(ACCP)2 (ACCP=2-acetylcyclopentanone), and Ti(Oi-Pr)2(HBP)2 (HBP=2-hydroxybenzophenone) were found to be stable toward moisture and air. Ti(Oi-Pr)2(ACCP)2 and Ti(Oi-Pr)2(HBP)2 were proved to have lower melting points and higher decomposition temperatures. However, these complexes are thermally stable and pyrolysis under an inert atmosphere resulted in incomplete decomposition. Ti(Oi-Pr)2(DPM)2 (DPM=dipivaloylmethane) and Ti(Oi-Pr)2(HFAA)2 (HFAA=hexafluoroacetylacetone) were sublimed substantially during the thermal decomposition. Pyrolysis mechanism of these complexes are dependent on type of β-diketone but removal of Oi-Pr ligands occurs before the decomposition of β-diketonate ligands.