• Journal of Educational Research in Mathematics
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• v.24 no.3
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• pp.333-357
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• 2014

This study resulted from a study regarding creative STEAM System based upon an experiment with the center of gravity. The results of the study are constructed by a fusion of mathematics and physics, showing that they are the same as mathematical calculations. Also, students can find that center of gravity of an object is in equilibrium on a metal rod when the center of gravity exactly is placed on the rod. The fact that an experimental results are correspond to calculations can maximize the effectiveness of teaching. And also this study has the following effectiveness. First, the exact construction and calculations arouses good competition among students. Second, this experiment can give students a motivation for study and increase their thinking in classes because the theoretical background of center of gravity experiment is basically attributed to math and science classes in school. This study includes three different types of center-of-gravity experiments. One is a simple type of experiment in which center of gravity exists inside of an object. Another is a complicated one in which the center of gravity is also inside of an object. However, the third type is an experiment in where the center of gravity is outside of an object. Therefore, it gives students an opportunity to discuss how to confirm equilibrium on a metal rod when the object has its center of gravity outside. Having discussions in class will allow students to have a critical way of thinking. In addition, searching for a way to solve a problem will increase creativity of students as well. And the last type is finding the center of gravity of a big acrylic panel where multiple objects are on the panel. According to the survey and interview conducted by students who participated in this program, teaching based on creative STEAM system helps students to get a better understanding and more fast acquisition of knowledge. We can expect that a well-planned creative STEAM system through a continuous study will be both effective and efficient in educating critical and creative students.

• Cartoon and Animation Studies
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• s.36
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• pp.147-165
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• 2014

Around the turn of 21st century, there has been a major technological shift in the animation industry. With development of reality-based computer graphics, major American animation studios replaced hand-drawn method with the new 3D computer graphics. Traditional animation was known for its simplified shapes such as circles and triangle that makes characters' movements distinctive from non-animated feature films. Computer-generated animation has largely replaced it, but is under continuous criticism that automated movements and reality-like graphics devaluate the aesthetics of animation. Although hand-drawn animation is still produced, 3D computer graphics have taken commercial lead and there has been many changes to acting of animated characters, which calls for detailed investigation. Firstly, the changes in acting of 3D characters can be traced from looking at human-like rigging method that mimics humanistic moving mechanism. Also, if hair and clothing was part of hand-drawn characters' acting, it has now been hidden inside mathematical simulation of 3D graphics, leaving only the body to be used in acting. Secondly, looking at "Stretch and Squash" method, which represents the distinctive movements of animation, through the lens of media, a paradox arises. Hand-drawn animation are produced frame-by-frame, and a subtle change would make animated frames shiver. This slight shivering acts as an aesthetic distinction of animated feature films, but can also require exaggerated movements to hide the shivering. On the contrary, acting of 3D animation make use of calculated movements that may seem exaggerated compared to human acting, but seem much more moderate and static compared to hand-drawn acting. Moreover, 3D computer graphics add the third dimension that allows more intuitive movements - maybe animators no longer need fine drawing skills; what they now need is directing skills to animate characters in 3D space intuitively. On the assumption that technological advancement and change of artistic expressionism are inseparable, this paper compares acting of 3D animation studio Pixar and classical drawing studio Disney to investigate character acting style and movements.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.10
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• pp.986-993
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• 2010

In this study, sorption characteristics of thermally treated activated alumina (AA) for fluoride were investigated. Sorption experiments have been conducted in equilibrium and kinetic batch conditions. Also, effects of solution pH and anions on fluoride removal have been observed. The properties of thermally treated ( $700^{\circ}C$) activated alumina (AA700) and untreated activated alumina (UAA) were compared using field-emission scanning electron microscope, energy-dispersive spectrometry, X-ray diffractometer (XRD) analysis, and Brunauer-Emmett-Teller (BET) analysis. From the experiments using AA thermally treated at different temperatures (100, 300, 500, $700^{\circ}C$), it was found that at high fluoride concentrations (50, 100, 200 mg/L) the sorption capacity of thermally treated AA increased with increasing thermal treatment temperature. At an initial fluoride concentration of 200 mg/L, the sorption capacity of AA700 was 3.67 times greater than that of UAA. The BET analysis showed that the specific surface area of UAA was about 2 times larger than that of AA700. The XRD analysis indicated that UAA was composed of both boehmite (AlOOH) and bayerite ($Al(OH)_3$) while AA700 was $Al_2O_3$. The reason that fluoride sorption capacity of AA700 increased despite of decrease in specific surface area compared to UAA could be attributed to the change of crystal structure. The kinetic sorption test showed that fluoride sorption to AA700 arrived at equilibrium after 24 h. The equilibrium test demonstrated that the maximum sorption capacity of AA700 was 5.70 mg/g. Additional batch experiments indicated that fluoride sorption to AA700 was the highest at pH 7, decreasing at both acidic and basic solution pHs. Also, fluoride sorption to AA700 decreased in the presence of anions such as phosphate, nitrate, and carbonate. This study demonstrated that thermal treatment of AA at high temperature could increase its sorption capacity for fluoride.

• Archives of design research
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• v.17 no.1
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• pp.339-346
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• 2004

Matrix, produced by Larry & Andy Wachowski, was relatively precisely dealt with the cyber world. After the movie was released, it had a mania for the movie and was adopted into a various forms of cultural products. It was remade not only into the parodies of the other movies and TV programs, but also the clothes and miscellaneous items of the movie were reincarnated as an unique cultural trend. The cause of the popularity is the fresh storyline as well as the sophisticated visual effects and good-looking actors. The agony of the protagonist was connected with the people outside the movie who are yearning for the ideal world. He was confused at the fact that his circumstances which were believed as the real world were not tortally true, complicated between the sensually phisical truth and the spiritual truth and had an will for the freedom that would ransack the truth and save the other people from the fictitious world. Consequently, the movie has got sympathies with many audiences suggesting the situation that has no a firm belief of the reality, the difference between the real and the cyber world is meaningless and the faked images of the high-technology are overturned This thesis tries to study the present that the real images are excessly duplicated and consumed, related to the Jean Baudrillard's theory, 'Hyperreel'. Replaced the real objects by a technical programming in the Matrix world, there happens the image-violence that the true nature is slaughterred by images. In the world where the reproducts are more actual than the reality and pretends to be real, only semiotics are consumed and produced. That is to say, the tortally programmed images has no references and aims, therefore should be produced in an 'impediment-strategy' like a faked crisis. That is the step of 'Simulation' that artificially reincarnates the real. Based upon the Baudrillard's theory, 'Simulacre', this study tries to research today's post-modern situation that the boundary of the real world and the faked copy is vague and vanishing, through the analysis of the cyber world of the movie 'Matrix'.

• Journal of Animal Science and Technology
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• v.46 no.5
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• pp.773-782
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• 2004

The objective of this work was to establish an approaching method for TMR feeding system in the farm situation by testing the effects of herd-mix feeding system on the performance of lactating cows. Fifty six Holstein cows were fed for the experimental period of 16 months. Prior to test the herd-mix feeding system, animals were kept on conventional feeding system for 4 months, separate feeding of forage with concentrate, then provided 3 types of herd-mix rations formulated by mean level of energy concentration requirement of higher 1/2 ranker in each herd for remaining 12 months to compare the effect on milk yield performance of animals with conventional feeding system by using a switch-over method. The herd-mix feeding system influenced substantially upon the improvements of milk yield(P<0.01) and milk fat percentage(P<0.05). In all of lactational ages, milk yield and milk fat were enhanced by the herd-mix feeding system. Especially, actual milk yield(AMY) and milk fat in the 1st lactating cows, and AMY and 4.0% fat corrected milk yield(FCM) in the 2nd lactating cows were increased signiticantly by the herd-mix feeding system(P<0.05). In the early and mid-stage of lactation, the herd-mix feeding system showed higher AMY and FCM compared with the conventional feeding system although the milk fat was not different. AMY, milk fat and FCM in the late-stage of lactation were increased generally by the herd-mix feeding system. Especially, milk fat and FCM obtained by the herd-mix feeding system were significantly higher than those by the conventional feeding system(P<0.01). The herd-mix feeding system showed a good type of milking curve with a higher persistency of FCM(93.24%) than in conventional one(92.69%). The income over feed cost with the herd-mix feeding system was lA-fold higher than that with the conventional feeding method. In conclusion, the results of this work suggest that the herd-mix feeding system based on a correct level of energy concentration of TMR and well-determined feed ingredients increases not only milk yield of dairy herd by enhancing the performance of cows in early to mid stage of lactation with improved milk persistency but also gross income of dairy farm.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.4
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• pp.22-34
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• 2016

The purpose of this study was to analyze commemoration characteristics of fifty-nine Vietnam war memorials in Korea(VWMK) including monuments and national cemeteries from landscape architectural point of view such as location, spacial characteristic, landscape detail, sculpture, and interpretive text. Based on the commemoration characteristics of the analysis, the commemoration culture among Vietnam, the U.S.A., and Korea were studied and differences compared. The results are as follows. First, monuments were mainly located in public open space such as national cemeteries, parks, and plaza, and some of them were elected along with Korea war memorials to honor Vietnam war veterans at the national level. Second, because the monuments were relatively small and memorial towers were conventionally built on a square platform, the memorial style had been simply standardized to stereotype the commemoration characteristics. Third, outmoded memorial towers, stone plates, emblems, and memorial walls were used as main landscape details and standardized facilities were considered from an artistic and social point of view. Fourth, realistic soldier statues to show heroic and humanitarian image were in majority, while symbolic and abstract sculpture were small in number, they were mostly conventional and unexpressive. Fifth, the causes of participation in the Vietnam War were predominantly expressed as 'defending freedom', 'keeping world peace', and 'national economic development' based on anti-communism and patriotism, and also the collectivity of Vietnam War veterans by troop and local level was emphasized through engraving each veterans's name on towers, plates, and walls. VWMK are mostly conventional and stereotyped in style and show strongly national official memory and the collectivity of veterans from a sociopolitical perspective, and aim for anti-communistic patriotism ideologically. Further study and projects will be required to make creative and innovative memorials and to study how to rethink sublime fundamental themes like war, death, and the individual veteran's experience in VWMK.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.855-858
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• 2006

First of all, Developing information technology makes it possible to change a paradigm of all kinds of areas, including an education. Students can choose learning goals and objects themselves and acquire not the accumulation of knowledge but the method of their learning. Moreover, Teachers get to be adviser, and students play a key role in teaming. That is, the subject of leaning is students. Constructivism emphasizes the student-oriented environment of education, which corresponds to the characteristics of hypeimedia. In addition, Internet allows us to make a practical plan for constructivism. Web Based Internet provides us with a proper environment to make constructivism practice md causes an education system to change. Sure Web Based Instruction makes them motivated to learn more, they can gain plenty of information regardless of places or time. Besides, they are able to consult more up-to-date information regarding their learning use hypermedia such as an image, audio, video, and test, and effectively communicate with their instructor through a board, an e-mail, a chatting etc. A school and instructors have been making effort to develop a new model of a teaching method to cope with a new environment change. In this thesis, with 'Design and Implementation of Web Based Instruction Based on Constructivism', providing online learner-oriented and indexed video lesson, learners can get chance of self-oriented learning. In addition, learners doesn't have to cover all contents of a lesson but can choose contents they want to have from a indexed list of a lesson, and they ran search contents they want to have with a 'Keyword Search' on a main page, which can make learners improve learner's achievement.

• Restorative Dentistry and Endodontics
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• v.32 no.4
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• pp.343-355
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• 2007

The objectives of this study was to evaluate the durability of 4 resin cements by means of microtensile bond strength test combined with thermocycling method and fractographic FE-SEM analysis. Experimental groups were prepared according to thermocycling (0, 1,000, 5,000) and the kind of resin cements, those were Variolink II, Multilink, Panavia F 2.0, Rely X Unicem. Flat dentin surfaces were created on mid-coronal dentin of extracted third molars. Then fresh dentin surface was grounded with 320-grit silicon carbide abrasive papers to create uniform smear layers. Indirect composite block (Tescera, Bisco Inc., Schaumburg, IL, USA) was fabricated ($12\;{\times}\;12\;{\times}\;6\;mm^3$). It's surface for bonding to tooth was grounded with silicon carbide abrasive papers from 180- to 600-grit serially, then sandblasted witk $20\;-\;50\;{\mu}m$ alumina oxide. According to each manufacturer's instruction, dentin surface was treated and indirect composite block was luted on it using each resin cement. For Rely X Unicem, dentin surface was not treated. The bonded tooth-resin block were stored in distilled water at $37^{\circ}C$ for 24 hours. After thermocycling, the bonded tooth-resin block was sectioned occluso-gingivally to 1.0 mm thick serial slabs using all Isomet slow-speed saw (Isomet, Buehler Ltd, Lake Bluff, IL, USA). These sectioned slabs were further sectioned to $1.0\;{\times}\;1.0\;mm^2$ composite-dentin beams. The specimens were tested with universal testing machine (EZ-Test, Shimadzu, Japan) at a crosshead speed of 1.0 mm/min with maximum load of 500 N. The data was analyzed using one-way ANOVA and Duncan's multiple comparison test at $p\;{\leq}\;0.05$ level. Within the limited results, we conclude as follows; 1. The bond strength of Variolink II was evaluated the highest among experimental groups and was significantly decreased after 1,000 thermocycling (p < 0.05). 2. The bond strength of Multilink was more affected by thermocycling than the other experimental groups and significantly decreased after 1,000 thermocycling (p < 0.05). 3. Panavia F 2.0 and Rely X Unicem showed the gradually decreased tendency of microtensile bond strength according to thermocycling but there was no significant difference (p > 0.05). 4. Adhesive based-resin cements showed lower bond strength with or without thermocycling than composite based-resin cements. 5. Variolink II & Multilink showed high bond strength and mixed failure, which was occurred with a thin layer of luting resin cement before thermocycling and gradually increased adhesive failure along the dentin surface after thermocycling. The bonding performance of resin cement can be affected by application procedure and chemical composition. Composite based-resin cement showed higher bond strength and durability than adhesive based-resin cement.

• Journal of KIISE:Information Networking
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• v.30 no.3
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• pp.329-342
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• 2003

Most of the existing multicast routing protocols for ad-hoc networks do not take into account the efficiency of the protocol for the cases when there are large number of sources in the multicast group, resulting in either large overhead or poor data delivery ratio when the number of sources is large. In this paper, we propose a multicast routing protocol for ad-hoc networks, which particularly considers the scalability of the protocol in terms of the number of sources in the multicast groups. The proposed protocol designates a set of sources as the core sources. Each core source is a root of each tree that reaches all the destinations of the multicast group. The union of these trees constitutes the data delivery mesh, and each of the non-core sources finds the nearest core source in order to delegate its data delivery. For the efficient operation of the proposed protocol, it is important to have an appropriate number of core sources. Having too many of the core sources incurs excessive control and data packet overhead, whereas having too little of them results in a vulnerable and overloaded data delivery mesh. The data delivery mesh is optimally reconfigured through the periodic control message flooding from the core sources, whereas the connectivity of the mesh is maintained by a persistent local mesh recovery mechanism. The simulation results show that the proposed protocol achieves an efficient multicast communication with high data delivery ratio and low communication overhead compared with the other existing multicast routing protocols when there are multiple sources in the multicast group.

• Korean Journal of Heritage: History & Science
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• v.53 no.2
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• pp.180-203
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• 2020

In this study, the period before the Gwanbok of meritorious vassals' portraits was expressed in the acheongsaek-Heuk-Danryung was defined as the first period, and the costumes worn in portraits of meritorious vassals from Gaeguk (1392) in the early Joseon Dynasty to Jwali (1471) during the era of King Seongjong were reviewed. The portraits(1476) of Jeokgae meritorious vassals (1467) depicted as the Gwanbok of acheongsaek Heuk-Danryung were excluded. Among the copies that are currently considered to be portraits of meritorious vassals belonging to the first period, the portraits of Lee-je, Lee Cheon-woo, Ma Cheon-mok, Shin Suk-ju, Seol Gye-jo, and Lee Sung-won were selected, and the formative characteristics of Gwanbok components were examined. The Samo of Sam-Gongsin in the early Joseon Dynasty had a low height, a rounded end, and the side wings were narrow and short. However, since King Danjong, Jeongnan·Jwali meritorious vassals retained a higher form, and the side wings were twice as long. It was also confirmed that the pattern was not expressed in the side wings. The Danryung was expressed in light-colored Danryung without specific colors at the beginning of the country. After King Sejong, the Heuk-Danryung system for Yebok began, but it was not reflected in the Gwanbok of meritorious vassals' portraits, and was expressed as damhongsaek-Danryung after King Danjong. The pattern was not expressed on the exterior of the Danryung, and inner-wrinkled Mu was expressed on the side line. The Dapho and Cheolrik, the undergarments of the Danryung, were also confirmed as being blue (the Dapho) and green (the Cheolrik) after the Jeongnan meritorious vassals. The early Sam-Gongsin's Pumgye was expressed by rank belt, but as the system of rank badge was established after King Danjong, it began to express the Pumgye by rank badge and rank belt. Among the portraits of meritorious vassals, the rank badge was expressed only in the portrait of Sin Suk-ju, a Jeongnan meritorious vassal. As Hwaja worn on the Danryung, Heuk-hwa were confirmed in the Sam-Gongsin portraits of the early Joseon Dynasty. However, in the portraits of Jeongnan and Jwali meritorious vassals after King Danjong, the Baek-hwa was confirmed. In addition, in the seam parts of the Heuk-hwa and Baek-hwa identified in some portraits of meritorious vassals, Hwi decorated with yeongeumsa were identified, and it was found that the Hwaja decorated with Hwi were the Hyeopgeum-hwa worn by the 3rd rank and above.