• Journal of Korean Home Economics Education Association
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• v.10 no.1
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• pp.41-57
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• 1998

The purpose of this study was to make a selection criteria for Home Economics textbooks in the middle school. For this purpose, first, the criteria were out by collecting, analyzing and synthesizing the literature. Second, questionnaire survey of the 6 selection criteria was performed. Questionnaire sent to Home Economics teachers of 401 middle school selected by systematic random sapling, 233 questionnaire were received and 220 questionnaire were analyzed for this study. As a statistical tool, SPSSWIN was used to analyze frequency, mean, standard deviation, and factor analysis. The research findings were as follows ; 1. Now for kinds of Home Economics textbooks are mainly used. At that time when textbooks were selected, these selections were made upon deliberation with the teachers in charge and in future this method will be desirable. Most home economics teachers realize that the selection criteria is needed to improve the objectivity of textbook selection. 2. As a result of making factor analysis, the selection criteria were revised that 52 items in 7 categories were chosen as textbook criteria plan. They consist of 5 items related to the outward form of textbook, 5 items related to the learning materials in textbook, 10 items related to the composition of textbook units, 11 items related to the guiding contents of textbook, 7 items related to the subject of experiment.practice, 9 items related to the composition of picture, photograph and diagram. and 7 items related to the use of instructional-learning method.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.4
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• pp.613-619
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• 1994

Dielectric properties of Ba(ZnS11/3TTaS12/3T)OS13T+x ZnO(x=0, 0.4, 0.8, 1.0 wt%) ceramics have been investigated at microwave frequencies. With excess ZnO, the sinterability was improved and the dielectric constant($\varepsilon$S1rT) and the unloaded quality factor(QS1UT) were increased. The structure changed into hexagonal from pseudocubic as being annealed at 140$0^{\circ}C$ in excess ZnO composition. Also, the temperature coefficient of the resonant frequency ($\tau$S1fT) turned into (-)ppm/$^{\circ}C$ when sintered at 155$0^{\circ}C$ for 2 hours. But the specimen sintered in ZnO muffling showed increased density and $\varepsilon$S1rT but lowerde QS1uT. Among the specimen investigated, expecially the composition added with 0.4wt% excess ZnO showed the most optimum dielectric values ($\varepsilon$S1rT=28, QS1uT x f=120000GHz) better than those of original Ba(ZnS11/2T TaS12/3T)OS13T ceramics.

• Journal of the Korean Ceramic Society
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• v.37 no.7
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• pp.632-637
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• 2000

Thermoelectric conversion properties of commercial Fe-Si2 and Fe-Si alloy ingots prepared by RF inductive furnace were investigated. As sintering temperature increased, density of the specimen increased and the phase transformation from metallic phases ($\varepsilon$-FeSi, ${\alpha}$-Fe2Si5) to semiconducting phase (${\beta}$-FeSi2) occurred more effectively. The FeSi phase was detected even after 100hrs of annealing treatment. For the Fesi1.95∼FeSi2.05 specimens prepared by RF inductive furnace, the thermoelectric property improved as the composition of the specimen approached to stoichiometric composition FeSi2. Electrical conductivity of the specimen increased with increasing temperatures showing typical semiconducting behavior. From the electrical conductivity measurements, activation energy in the intrinsic region (above about 700 K) was calculated to be approximately 0.46 eV. In spite of non-doping, the Seebeck coefficient for every specimen exhibited p-type conduction due to Si deficiency. Its maximum value was located at about 475 K, and then decreased abruptly with increasing temperatures. The power factor was governed by the Seebeck coefficient of the specimen more significantly than by electrical conductivity.

• Journal of the Korean Institute of Educational Facilities
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• v.16 no.1
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• pp.69-77
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• 2009

This study, as one of the specific suggestions to satisfy the social needs of life long education and to overcome the limitations of the supply of regional facilities, presents plans for the possibility of the mixed-use of educational facilities and regional facilities as the ultimate objective. By focusing on the space composition of the mixed-use facility to execute the roles of the educational establishment actively and efficiently, the purpose is to present the mixed-use methodology in architectural plan on which functions to combine and by how much, when the mixed-use plan of educational facilities. The investigation objects was the 27 elementary schools in Seoul which have undergone mixed-use of educational facilities work as at August, 2007. And each educational facility was classified mixed-use functions and analyzed for the composition form of functions and the characteristics by functions. And for mixed-use facility, form types were derived from the relationship with the school buildings through the analysis on characteristics, strengths and weaknesses of each types were presented by factor-by-factor plan directions of mixed-use facility.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.5
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• pp.132-139
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• 2008

To meet demand of big capacity and high speed rotation for washing machine, more stress from bending and twisting are complexly loaded onto the shaft supporting the horizontal drum, causing problems in fracture strength and fatigue life. Also, Vibration occurs due to the frequency of the rotating parts. But, shaft has various design factors such as diameter and distance between bearings according to configuration of shaft, the optimal values can't be easily determined. Using a design of experiment (DOE) based on the FEM (Finite Element Method), which has several advantages such as less computing, high accuracy performance and usefulness, this study was performed investigating the interaction effect between the various design factor as well as the main effect of the each design factor under bending, twist and vibration and proposed optimum design using center composition method among response surface derived from regression equation of simulation-based DOE.

• Fisheries and Aquatic Sciences
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• v.24 no.9
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• pp.311-317
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• 2021

Inclusion effect of various levels of jack mackerel meal (JMM) acting as feed attractants and/or stimulants in diets on the growth, feed consumption, feed utilization and whole body composition of rockfish was investigated. Three hundred juvenile rockfish were randomly allocated into 15 flow-through tanks. Five experimental diets supplemented with JMM at 0%, 1%, 3%, 5%, and 10% at the expense of anchovy meal were prepared and referred to as the JMM0, JMM1, JMM3, JMM5, and JMM10 diets, respectively. Weight gain, specific growth rate (SGR) and feed consumption of fish tended to improve with dietary levels of JMM. The greatest weight gain, SGR and feed consumption were observed in fish fed the JMM10 diet, followed by the JMM5, JMM3, JMM1, and JMM0 diets, in that order. Condition factor (CF) of fish tended to improve with dietary inclusion levels of JMM. Growth performance, feed consumption and CF of fish tended to improve with dietary inclusion levels of JMM ranging from 0% to 10%.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.3
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• pp.232-235
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• 2008

In this study, in order to develop the composition ceramics for multilayer piezoelectric actuator, PMN-PNN-PZT ceramics were fabricated using $Li_2CO_3$, $Na_2CO_3$, ZnO as sintering aids and their piezoelectric and dielectric properties were investigated according to the Bi substitution, Bi substitution induced grain growth and increase of sinterablity, And also, Bi substitution suppress secondary phase due to the liquid phase sintering effect. Bi substitution enhanced electromechanical coupling factor ($k_p$) and dielectric constant ($\varepsilon_r$), However, mechanical quality factor($Q_m$) was deteriorated, At the sintering temperature of 870 $^{\circ}C$ and Bi substitution of 1 mol%, density, electromechanical coupling factor ($k_p$), mechanical quality factor ($Q_m$), Dielectric constant ($\varepsilon_r$) and piezoelectric constant ($d_{33}$) of specimen showed the optimum values of 7,878 $g/cm^3$, 0,608, 835, 1603 and 397 pC/N, respectively for multilayer piezoelectric actuator application.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.5
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• pp.356-361
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• 2001

The structureal, dielectric and piezoelectric properties of Pb[(Sb$\_$1/2/Nb$\_$1/2/)$\_$x/-(Ni$\_$1/3/Nb$\_$2/3/)$\_$0.15-x/-(Zr$\_$y/Ti$\_$1-y/)$\_$0.85/]O$_3$(x=0∼0.05, y=0.47∼0.52) ceramics were investigated with the substitution of Pb(Sb$\_$1/2/Nb$\_$1/2/)O$_3$(abbreviated PSN) and the Zr/Ti ratio. At Zr/Ti ratio of 50/50, tetragonality was decreased and grain size abruptly decreased with the increase of PSN substitution. Curie temperature was decreased and dielectric constant increased with the substitution of PSN. The coercive field increased and remnant polarization decreased with the substitution of PSN. Electromechanical coupling factor(k$\_$p/) showed the highest value of 0.622 at 1mol% PSN, but mechanical quality factor(Q$\_$m/) showed the minimum value at that composition. Dielectric constant and electromechanical coupling factor with the Zr/Ti ratio showed maximum values at Zr/Ti ratio of 50/50 and mechanical quality factor showed minimum values near the Zr/Ti ratio of 50/50.

• Korean Institute of Interior Design Journal
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• v.22 no.4
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• pp.70-77
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• 2013

This study has analysed the composition elements in a cafe space where visual transfer-elements are filled and the perceptual characteristics of facade designs with the purpose of drawing any important elements to advertisement and their related items for uniqueness of designs. For the analysis of the perception process shown in the consecutive situations of observing and visiting cafes, the cafe facade was grouped and stereotyped for the analysis of perceptual characteristics and significant composition elements for better designing of cafes through survey with representative facades as subjects. The conclusions from this study are the followings. First, for the uniqueness specific to cafes to be integrated into facade, memory was chosen first as the most significant advertisement factor followed by interest as with male and attention as with female. The memory has much to do with furniture and finishing material of Clause (4), Chapter 4.1 and the types having effects on perception of Clause (1) and the atmosphere having effect on that of Clause (2) were found to be major factors to attention and interest. Second, it was found out that women preferred horizontally stable partition and men clearly divided facades. The factor of shape was observed first among the constituents of facade followed by color. There was no difference with 'shape' between men and women and color was found to be a space constituent having a lot of effects on women. Third, the memory of experience from visiting a cafe was very likely to offer the motivation of visiting it again, on which furniture had the most effect followed by finishing material and color. Such elevation elements as facade and logo were found not to have effect on the memory or the re-visit. Any intention of visiting again seemed to be influenced by such comprehensive images as atmosphere rather than by any concrete facade, furniture, or appliance. From the above viewpoint, facade design should have any uniqueness or impressive feature as well as the effect of making passers-by drop in and attracting them into the shop. The analysis of attributes of facade constituents revealed that the abstract images in addition to the configuration of facade had much to do with interest or behavior.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.6
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• pp.699-708
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• 2005

To characterize the elemental composition of fine particles in urban area, $PM_{2.5}$ was collected by a 3-stage DRUM impactor at Gwangju during spring and summer. Time and size resolved concentrations for 19 trace elements were obtained by synchrotron X-Ray fluorescence analysis. Trace elements in summer were distributed in smaller size range compared to those in spring. Almost trace element concentrations in fine particles were highly increased during the Asian dust. In spring, soil elements such as Si, K, Ca, Ti and Fe had low enrichment factors indicating the dominant influence of soil dust. However, all elements had high enrichment factors in summer implying that these elements could be emitted from the anthropogenic sources. Factor analysis was conducted with the elemental composition data in order to identify anthropogenic sources of aerosols in urban area during spring and summer. Fine particles in spring have several sources such as soil dust originating from China continental region, coal and oil combustion, biomass burning, sea salt, ferrous and nonferrous metal sources. On the other hand, fine particles in summer were influenced by road dust, gasoline vehicle as well as coal and oil combustion, sea salt, ferrous and nonferrous metal sources.