• Composites Research
• /
• v.19 no.1
• /
• pp.29-35
• /
• 2006

The avoidance of enemy's radar detection is very important issue in the modem electronic weapon system. Researchers have studied to minimize reflected signals of radar. In this research, two types of radar absorbing structure (RAS), 'C'-type shell and 'U'-type shell, were fabricated using fiber-reinforced composite materials and their radar cross section (RCS) were evaluated. The absorption layer was composed of glass fiber reinforced epoxy and nano size carbon-black, and the reflection layer was fabricated with carbon fiber reinforced epoxy. During their manufacturing process, undesired thermal deformation (so called spring-back) was observed. In order to reduce spring-back, the bending angle of mold was controlled by a series of experiments. The spring-back of parts fabricated by using compensated mold was predicted by finite element analysis (ANSYS). The RCS of RAS shells were measured by compact range and predicted by physical optics method. The measured RCS data was well matched with the predicted data.

• Journal of The Korean Association For Science Education
• /
• v.40 no.2
• /
• pp.177-189
• /
• 2020

In this study, we implemented an education program to improve the responsive teaching ability of pre-service science teachers, and analyzed the responsive teaching practices revealed during the program process. Through this, we derived the types and characteristics of responsive teaching practice, identified factors that made it difficult for pre-service teachers to practice, and obtained empirical data on under what conditions the responsive teaching capacity of pre-service teachers was developed. For this purpose, a practice-based teacher education program was designed and carried out for 14 pre-service teachers who had no experience in responsive teaching. The program consists of four steps; observation of class, practice through rehearsal, application in practicum, and post-reflection on educational practice. In particular, qualitative analysis was conducted on the types of responsive teaching and their detrimental factors revealed during application in practicum. As a result of the analysis, four types were derived; discriminator type, communicator type, guide type, and facilitator type. Each type was identified as having a common responsive teaching step element. The education program implemented in this study was effective for pre-service teachers to recognize the importance of student-participation class and the educational effect of responsive teaching. However, three barriers that prevented pre-service teachers from responsive teaching practice were also analyzed. First was the pressure to achieve specific learning goals within a given class time. Second was the rigid belief of the fixed curriculum. Third was the obsession that the teacher should lead the class. Based on these results, it was suggested that in order to improve the responsive teaching ability of pre-service teachers, it is necessary to support the recognition of breaking out of the thinking the time constraint, the flexibility of the curriculum, and the role of teacher as a class supporter.

• Journal of Korean Ophthalmic Optics Society
• /
• v.19 no.4
• /
• pp.527-532
• /
• 2014

Purpose: The matching of the optical center and the pupil center was measured by photographs in wearing glasses. In this study, the influences of the induced prism by the mismatching are studied. Methods: 74 subjects (148 eyes) who were spectacles wearer were participated in this study. The mean age was $29.19{\pm}12.22$ years (range 19-55 years). The facial photographs of subjects were taken while wearing spectacles. The matching of the corneal reflected image and optical center of the spectacle lens in the horizontal deviations, and the vertical deviations were measured by the observation of the photo image. The prisms induced in accordance with various frame type were calculated from the mismatching deviations. Results: The binocular horizontal deviations were $1.55{\pm}1.70mm$ for the metal frame, $1.71{\pm}2.21mm$ for the clings type plastic frame, and $1.15{\pm}1.38mm$ for the plastic frame. In the horizontal direction induced prism, the ratio over the tolerance was 23%. The ratio were the 17.6% at the BI prism, and 5.4% at the BO prism. The binocular vertical deviation comparisons were $3.93{\pm}1.91mm$ for the metal frame, $5.79{\pm}1.93mm$ for the clings type plastic frame, and 1$6.01{\pm}2.94mm$ for the plastic frame. In the vertical direction induced prism, the ratio over the tolerance was 44.6%. Based on the refraction power, the ratio were 12.2% at -0.25${\leq}-3.00$, and 32.4% at -3.00${\leq}-12.00D$. Conclusions: The induced prisms in the horizontal direction were much in the BI prism. The binocular vertical deviations of the glasses.

• Korean Journal of Environment and Ecology
• /
• v.24 no.6
• /
• pp.751-762
• /
• 2010

In order to understand the influence that the plant cover condition of the high-rise building outer space causes to the temperature change, we selected 12 high-rise building constructed in Seoul City. The land cover type of the outside was classified into six type(outer road, paved surface, shrub/grassland, single-layer tree planting-site, multi-layer planting-site, and waterscape facilities) and the temperature was measured at the representative point for each type in order to analyze the land cover temperature differential for each type of the high-rise building outer space. The study area showing the temperature tendency to be similar based upon one way analysis of variance after selecting the central part of the outer road for a control and measuring a temperature in order to consider the neighboring environmental difference of the dozen building was classified into 4 groups. As to the one-way layout result of variance analysis with the land cover type of the classified group and outer space temperature, the single-layer tree planting-site, waterscape facilities, and multi-layer planting-site belonged mainly to the low temperature section. The shrub/grassland, paved surface, and outer road belonged to the high temperature region. The temperature difference between low temperature region and high temperature region is about $1.06{\sim}6.17^{\circ}C$. However, the temperature in the Outer Space of the Super-High-Rise Building was variously appeared by the influence such as the cramped of the created planting-site and waterscape facilities area, the increase of amount of solar radiation and the reduction of reflection amount of light due to building etc.. Thus, the composition all produced the area of the green quantity required for each space and water space in advance. It was determined that there were the minimum area displaying an effect and the necessity to it secures the green quantity.

• Korean Journal of Social Welfare
• /
• v.60 no.2
• /
• pp.99-129
• /
• 2008

This study analyzed the resilience process of persons with disabilities using the grounded theory approach. To conduct this study, the researcher conducted in-depth interviews with 8 persons with disabilities. In data analysis, this study identified 393 concepts on the resilience process of persons with disabilities and the concepts were categorized into 45 sub-categories and 18 primary categories. In the paradigm model on the resilience process of persons with disabilities, it was identified that casual conditions included 'unawareness of disability before being disability', 'extreme pain', 'repressing psychological pain', and the contingent conditions were 'dis-empowerment by staying in home', 'isolation by himself with difficulty in accepting the disability', 'experience of frustration from social barriers with prejudice against persons with disabilities'. Also, it was identified that the resilience process could be dependent on the type and the degree of the disability, the gender, and the length of time being disability. In spite of the casual and contingent conditions, the central way in which persons with disabilities could acquire resilience was identified as 'enhancement of the power of positive thinking'. The control conditions which accelerate or retard central phenomenon were 'the awareness of not being alone through family, friends, neighborhood and the social system' externally and 'finding purpose in life through religion and help from other persons with disabilities', internally. The action/interactional sequences enhanced the efforts, self searching and active acting, and as a result, persons with disabilities could find comfort in life, participate in society and change the perspective of disability in society. The core categories of resilience process in persons with disabilities were a belief in affirmation and choice of life by initiative. In the process analysis, stages developed in the following: 'pain', 'strangeness', 'reflection', 'daily life'. This stage was more continuous and causal than discrete and complete. In this process, the types of resilience of persons with disabilities are divided into 'existence reflection', 'course development', 'implicit endeavor', and 'active execution'. This study showed the details of the paradigm models, the process and types with an in-depth understanding of the resilience process of persons with disabilities using grounded theory as well as theory construction and policy and clinical involvement on the study of persons with disabilities.

• The Journal of Korean Philosophical History
• /
• no.25
• /
• pp.223-249
• /
• 2009

This papers focuses on the Confucian classics for the correct orientation of education as a basic task of the Confucian classics will as a necessary whether the need for education, to identify the natural history study will attempt to have. In East Asia means that classics, the classicalization process of looking at Chinese culture, classicalization of review of the cultural meaning. And this papers focuses on the historical evolution of education, and education in China and Korea in the modern world the meaning of the Confucian classics education about and looked at two dilemmas. And outside the scope of Confucian five ethical thoughts as main moral to find new values and new interpretations about the legitimacy and philosophical thinking of the meaning of the Confucian classics Education. In addition, the development of educational content to the new Confucian classics on the subject of three applies to the existing approach and to propose a new type of comparison?Review. As primitive Confucian classics is not determined by a priori, the modern understanding of the Confucian classics also thorough review process of reflection and understanding the new system will have to be reconfigured. Furthermore, in the richness of modern society as the training methods as well as the development of relevant content for the modern society that values education's development is a very important issue. In this respect, should not be overlooked here is not about education, the effect of Confucian classics is concerned about the review. To this, first of all the Confucian classics need education about the content and strict screening operation. In addition, the ability to function in modern society, modern reinterpreted and the need to find a new educational element is. Because we did not give a realistic benefits and future view and any history or civilization, is always disappear in history. This series of problems will be a reason of require that philosophical thinking of Confucian classics education.

• Journal of The Korean Association For Science Education
• /
• v.43 no.3
• /
• pp.253-263
• /
• 2023

This study explored the discrepancy between the text of a teacher's guide about straight and reflective light and the content knowledge of pre-service elementary teachers. A total of 455 questions and 543 answers generated by 279 pre-service elementary teachers after reading a 'Shadow and Mirror' unit in the teacher's guide were analyzed. The questions were classified according to the types of concepts and discrepancies, and the answers were analyzed for accuracy. The results of analyzing the concepts of questions revealed that the pre-service elementary teachers were most curious about the shadow in the straight concept, the mirror image in the reflection concept, and the light source in other concepts. The questions with a low correct answer rate due to incorrect- or non-answers, such as those concerning the superposition principle of light by reflection, the principle of experimental tools, and images by lenses, were only partially or not included in the teacher's guide. When the questions were classified according to the type of discrepancy, the frequency of questions due to knowledge deficit was higher than that due to knowledge clash. This demonstrates that the concepts that teachers need to know must be supplemented with the contents of the teacher's guide. Discrepancies due to knowledge clashes are often caused by conflicts between what is experienced in everyday life and what is presented in textbooks. Therefore, it is necessary to reduce the discrepancy between the texts of the teacher's guide and the knowledge of pre-service elementary teachers by including the differences between the actual context of everyday life and the context of the textbook in the teacher's guide.

• Korean Journal of Heritage: History & Science
• /
• v.54 no.3
• /
• pp.242-261
• /
• 2021

Sangjeong was a sculptor-monk who was active in the mid-to-late 18th Century, and the current study established the overall chronology of Sangjeong's Buddhist statues and their styles based on the six sculptures of Sangjeong already known and the Wooden Seated Buddha of 1767 in Songgyesa Temple, Geochang, which was found to be his last work. All of the Buddhist statues of Sangjeong have commonalities in terms of the appearance of the ears, wrinkles on clothing on the upper and lower body, position of hands, and expression of the lower body. The expression of the lower body, in particular, is classified into three types: Type A, where the clothing drapes through the lotus leaves on the bottom; Type B, with an 'S-shaped' drape over the lower body but no lotus leaves or pedestal; and Type C, with the Buddha and pedestal as a single unit, and the clothing draping through the lotus leaves on the pedestal. It appears that Sangjeong faithfully succeeded the style of Taewon, who was his only instructor for sculpture. This is verified based on the records of his participation in the creation of the Wooden Seated Sakyamuni Buddha Triad and Statue of Arhat in Bongeunsa Temple, Seoul, as the third sculptor-monk out of twelve sculptor-monks, and the reflection of the S-shaped drape on the lower body found on the statue of Buddha in Bongeunsa Temple on all of the statues created by Sangjeong. Not only that, but it was assumed that the expression of the pedestal and hair was also inherited by Sangjeong from Taewon and Jinyeol, who was a sculptor-monk from the early 18th Century. The work of Sangjeong and Taewon showed differences in the volume and thickness of statues, strength of unevenness on the wrinkles of clothing, drapes on the right side of chest, and details of the ears. The current study identified the original styles of each individual sculptor and attempted to categorize the fourteen pieces of ten Buddhist statues reflecting the styles of Sangjeong into Sangjeong-style or Taewon-style.

• Economic and Environmental Geology
• /
• v.19 no.spc
• /
• pp.207-226
• /
• 1986

The skarn type tungsten deposits in Jechon area are developed in the contact aureole of Jurassic granodiorite and lower Paleozoic limestone beds. The Tong Myeong mine contains scheelitebearing skarns found at and near the contacts between crystalline limestone and hornfels. Although the skarns are heterogeneous, there are clear patterns in the preferred associations and nonassociations of minerals on all scales. The skarn show a zonal arrangement from limestone to hydrothermal vein as follow: wollastonite skarn, clinopyroxene skarn, clinopyroxene-garnet skarn, garnet skarn, and vesuvianite skarn. Scheelite, abundant in all skarn units except wollastonite skarn and also in quartz veins near orebodies, is everywhere strongly correlated with pyrrhotite. It is implied that it was a stable phase throughout the evolution of the zoned skarns, at least in pyrrhotite.forming environments. Deposition of scheelite was probably widely caused by increasing $a_{Ca^{2+}}$ in the fluid, resulting from associated and interrelated reactions: $FeCl_2\;aq+H_2S\;aq{\rightarrow}FeS+2H^{+}+2Cl^-$; and $CaCO_3+2H^+{\rightarrow}Ca^{+2}+H_2CO_3$. The spectral reflection powers of nine sulfide species were studied, for three mineralization stage. The shapes and characteristics of the spectral reflectivity profiles are significant in their control of other optical properties. The characteristics of the Vickers microhardness and the optical symmetry for the minerals studied are discussed. Broad radicle groupings of the sulfides can be made with regard to the reflectivity-microhardness values.

• Polymer(Korea)
• /
• v.30 no.4
• /
• pp.338-349
• /
• 2006

Fully or nearly fully(8-cholesteryloxycarbonyl)heptanoated polysaccharide derivatives were synthesized by reacting cellulose, amylose, chitosan, chitin, alginic acid, pullulan or amylopectin with (8-cholesteryloxycarbonyl)heptanoyl chloride (CH8C), and their thermotropic liquid crystalline behaviors were investigated. Like in the case of CH8C, all the polysaccharide derivatives formed monotropic cholesteric phases with left-handed helicoidal structures whose optical pitches $({\lambda_m}'s)$ decrease with increasing temperature. Amylopectin derivative also formed a monotropic cholesteric phase with lefthanded helicoidal structures but, in contrast with the other derivatives, did not display reflection colors over the full cholesteric range, suggesting that the helicoidal twisting power of the cholesteryl group highly depends on the branched structure in amylopectin. The thermal stability and degree of order in the mesophase, the magnitude of ${\lambda}_m$ at the same temperature, and the temperature dependence of the ${\lambda}_m$ observed for polysaccharide derivatives were entirely different from those reported for the polymers in which the cholesteryl groups are attached to flexible or semiflexible backbones through flexible spacers. The results were discussed in terms of the difference in the chemical structures of the main and side chains and flexibility of the main chain.