• Journal of the Korean School Mathematics Society
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• v.9 no.1
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• pp.105-120
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• 2006

The Seventh Curriculum makes sure that those students who don't have a proper understanding of contents required at a certain stage take a remedial course. But a trend contrary to the intention is formed since there is no systematic education for such a course and thus more students get to fall into the group of low achievement. In particular, solving a simultaneous equation in a rote way without understanding influences negatively students' achievement. Schoenfeld introduced the basic elements of one's own mathematical problem solving process and behavior, referred to Polya's. Employing Schoenfeld's strategy, this study aimed to induce students' active participation in math classes, as well as to focus on a mathematical problem solving process during the study. Two students were selected from a remedial course at 00 Middle School and administered with a qualitative case study method over 17 lessons, each of which lasted for 30 minutes. In the beginning, they used such knowledge as facts and definitions a lot. There was a tendency of their resorting to intuitive knowledge more when they lacked basic knowledge or met with a difficult question. As the lessons were given, however, they improved their ability to implement algorithm procedures and used more familiar ones with the developed common procedures in the area of resources.

• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.22-34
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• 1998

The purpose of this study is to develop biosensor for determination of glucose, lactate, and ethanol in foods and food-stuffs simultaneously. The multiple cathode system was prepared with an oxygen electrode having one anode and hexagonal cathode. Glucose oxidase, mutarotase, lactate oxidase, alcohol oxidase and catalase were used for immobilization to determine glucose, lactate, and ethanol. These components including ethanol were simultaneously determined by the immobilized enzymes in the multiple cathode system. The determination of the components by enzyme sensor was based on the maximum slope of oxygen consumption from enzyme reaction of each sensor part. The response time for analysis was 1 min. The optimum condition for glucose, lactate and ethanol sensor was found to be 0.1 M potassium phosphate buffer, pH 7.0 at $40^{\circ}C$. Interferences of various sugars and organic acids were investigated. Less than 10% of error was found in determination of the components except organic acids. This difference was compensated by the modified equation. This system was confirmed by conventional methods. It was concluded that the multiple cathode system of this study is for an effective method to determine sugar, organic acid, ethanol simultaneously in foods.

• Analytical Science and Technology
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• v.14 no.4
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• pp.1075-1081
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• 2001

Instrumental Neutron Activation Analysis as a representative method of nuclear analytical technique, has advantages of non-destructive, simultaneous multi-element analysis with the characteristics of absolute measurement method. Up to date, $k_0$-quantitative method which is accurate, convenient and user-friendly, has been generalized world-widely. In this study, it is intented to introduce the general concept of $k_0$-method and to measure $k_0$-parameters for the future implementation to our NAA system. For this objectives, the definition of relevant factors for the quantitative analysis and the equation for the experimental determination of parameters such as $Q_0$(${\alpha}$) and f were summarized. Furthermore, a foundation for the $k_0$-standardization method was prepared through the measurement of ${\alpha}$ and f-value which depend on the specific character of irradiation hole at NAA#1-hole of HANARO research reactor.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.4
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• pp.297-305
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• 2018

In a shipyard, block lifting is an important process in the production of ships and offshore structures. Block lifting is a sensitive process because lifting blocks have to be erected with exact positions and orientations. If we use a numerical method for the process, it is important to find tensions of wires and positions of equalizers to maintain the initial equilibrium position of the block. At this time, equations of motion of the block should be solved to calculate the initial equilibrium position of the block. Because the solving technique changes according to the number of equalizers, a suitable equation for the corresponding problem is required. In this study, three types of equations are proposed to find the initial equilibrium position of the block according to the number of equalizers. The Newton-Raphson's method is used to solve nonlinear simultaneous equations and the optimization method is used to determine the appropriate solution to the undetermined problem. To evaluate the applicability of the proposed methods, the dynamic simulations are performed using the tensions calculated from the proposed methods, and the results are discussed. The results show that the proposed methods can be effectively used to determine initial equilibrium position of the block for the block lifting.

• Korean Journal of Health Education and Promotion
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• v.24 no.4
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• pp.161-179
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• 2007

To commonly apply the ${\ulcorner}$Measurement parameter for housewives for rearing-related supports of a husband${\lrcorner}$ in Korea and Japan, the current study conducted to confirm the relationship between recognition of a housewife for rearing-related supports of a husband and mental health after reviewing the appropriateness of the parameter. For the statistical analysis, 829 married Korean women in D city and 1,302 Japanese women in S city having children before entering a school were subjected for the study. For reviewing the appropriateness of the parameter, the simultaneous factor analysis that adopted the structural equation modeling was used. As the result of the analysis, 10 categories of factor structural model comprising the ${\ulcorner}$Recognition of a housewife for rearing-related supports of a husband${\lrcorner}$ resulted with the secondary model which sets of ${\ulcorner}$Recognition for emotional support${\lrcorner}$, ${\ulcorner}$Recognition for instrumental support${\lrcorner}$ and ${\ulcorner}$Recognition for information support${\lrcorner}$ as the primary factor and ${\ulcorner}$Recognition of a housewife for rearing-related supports of a husband${\lrcorner}$ as the secondary factor, and the model was found to be appropriate for the data in Korea and Japan. The result is considered to prove the constructs validity of ${\ulcorner}$Recognition of a housewife for rearing-related supports of a husband${\lrcorner}$ parameter. In addition, the relationship between ${\ulcorner}$Recognition of a housewife for rearing-related supports of a husband${\lrcorner}$ and mental health(GHQ) was reviewed by using multiple indicator model, and found the similarity of Korean and Japanese data. The scores measured by using the above parameter resulted to show high relationship with educational level of housewife, family configuration, and number of children.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.2101-2101
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• 2001

Near-infrared spectroscopy is now being used in clinical diagnosis as a non-invasive monitor of tissue oxygenation state. However, due to lack of the optical pathlength information within tissues, it is still difficult to quantitate the hemoglobin concentration with present CW techniques. Time-resolved spectroscopy (TRS), which measures temporal profiles of emerging light from tissues, enables to estimate the pathlength distribution within tissues by converting time to distance. Consequently, quantitative measurement of tissue oxygenation is possible by analyzing the data with optical diffusion equation 1) or our Microscopic Beer-Lambert law2). Time-Resolved Spectroscopy System : TRS-1O3) Our TRS-10 system consists of a three-wavelength (759, 797, 833 nm) PLP as pulsed light source, a high speed PMT with high sensitivity and three signal-processing circuits for time-resolved measurement (CFD/TAC, A/D converter and histogram memory). Optical pulse train consisting of 759, 797 and 833nm is generated by PLP at 5㎒ repetition rate and irradiated a sample through a single optical fiber. The diffuse-reflected light from the sample is collected by a bundle fiber and then detected by the PMT for single photon measurement. After being amplified by a following fast amplifier, the electrical signals for each wavelength are picked out by CFD/TAC module. Then, a signal processing circuit integrated the TRS data for each wavelength individually. The simultaneous TRS measurement for three wavelengths achieved without any optical or mechanical switch. Experiment and Results Input and detection fibers of TRS-10 were attached at the human forehead with a fiber separation of 3cm. TRS measurements were continuously performed for about 20 minutes including 2 minutes hyper ventilation. It was observed that the total hemoglobin concentration was decreasing during the hyper ventilation and recovered until 2 minutes after hyper ventilation. On the other hand, the deoxy-hemoglobin concentration began to increase after hyper ventilation and had its peak at around 2 minute later, showing 502 drop from 75% to 60% due to inhibition of breathing by performing hyper ventilation. The results showed that this system might be able to quantitate the concentrations of oxy- and deoxy-hemoglobin in the human brain.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.23
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• pp.3-38
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• 2004

On-line game business has emerged as the most lucrative entertainment industry, with over 4 million players in China, with more than 45% of the market dominated by Korean on-line games. While the interactive entertainment market continues to expand, with many new Korean on-line game publishers entering the market, relatively little is known about which factors influence online game players' behavioral intentions (i.e., intention to play, brand-identity, word of mouth, flow, etc.) in this area. It appears that in this extremely attractive and growing services segment, academics, as well as practitioners, would benefit from investigating the relationships among the players' intention to play, social norms, word of mouth, flow, and the impacts of several other key game-related constructs. A conceptual framework is proposed and a simultaneous equation model is developed. This paper develops the exploratory LISREL model for identifying the factors affecting the players' intention to play for on-line games. Based on data collected from on-line questionnaire survey in China, the validity of the model has been tested and interesting conclusions have been developed concerning the relationships between the game-related constructs. It is hoped that this result might provide the useful guidelines for developing the successful on-line game contents. With better understanding of the players' behavioral intentions, Korean on-line game developers should be able to penetrate the China market with sustainable advantage over their competition.

• Journal of Korea Multimedia Society
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• v.16 no.12
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• pp.1385-1392
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• 2013

There is a variety of researches about recognition system using biometric data these days. In this study, we propose a new algorithm, uses simultaneous equation that made of the edge of objects, to segment an iris region without threshold values from an anterior eye image. The algorithm attempts to find a center area through calculated outskirts information of an iris, and decides the area where the most points are accumulated. To verify the proposed algorithm, we conducted comparative experiments to Hough transform and Daugman's method, based on 50 images anterior eye images. It was found that proposed algorithm is 5 and 75 times faster than on each algorithm, and showed high accuracy of detecting a center point (95.36%) more than Hough transform (92.43%). In foreseeable future, this study is expected to useful application in diverse department of human's life, such as, identification system using an iris, diagnosis a disease using an anterior image.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.189-195
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• 1999

We have studied the vortex dynamics in YBa$_2Cu_3O_7$ single crystals with columnar defects using micro Hall-probe array. The Hall-probe array technique allowed a simultaneous measurement of the time and spatial dependence of the vortex density so that more detailed information on flux dynamics could be obtained. We found that field profiles inside sample were similar to the Bean's critical state model from the magnetic hysteresis measurement. Normalized relaxation rates were maximum near the center and decreased toward the edge if applied field H$_{app}$ is greater than the penetration field H. But applied magnetic field H$_{app}$ is less than H, relaxation rates were minimum near the center and increased toward edge. We found that glassy exponent ${\mu}$ has the value of ${\sim}$ 1 whose corresponding vortex motion is half-loop excitation. However, single vortex creep, ${\mu}$ ${\sim}$ 1/7, was also found at 30 K and H$_{app}$ ${\cong}$ H'. Calculation of activation energy, U, was possible from direct analysis of the local relaxation data using the basic diffusion equation. From these results, we found that U increases logarithmically with time and U around center was lower than that at the edge.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.395-406
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• 2011

In this research a numerical simulation method is developed for moving body in free surface flows using fixed staggered rectangular grid system. The non-linear free surface near the body is defined by marker-density method. The body boundary is defined by line segment connecting the points where the body surface and grid line meet. Continuity equation and Navier-Stokes equations are used as governing equations and the equations are coupled with two-step projection method. The velocities and pressures of body boundary and free surface cells are calculated with simultaneous iterative method. To treat a body movement in a fixed grid system, the volume displaced by moving body is added to the divergence of the body boundary cell. For the verification of the present numerical method. vortex shedding period of advancing cylinder is calculated and the period is compared with existing experiment results. Moreover, added mass and damping coefficients of a vertically excited box are calculated and the computed results are compared with published experiment results. Impulsive pressure and water level variation due to sloshing phenomenon are simulated and the results are compared with published experiment results. Varying the plunger shape, the waves generated by plunging type wave maker are compared with the 2nd order Stokes wave theory The plunger shape generating the wave that shows the best agreement with the theory is represented.