• Korean Journal of Heritage: History & Science
• /
• v.51 no.4
• /
• pp.108-119
• /
• 2018

"The Collection of Yi Chungmugong" manuscript is a hand-written manuscript of the volume 1 consisting of the Collection, published in 1795 and it seems to have completed the contents of the book by correcting the first part of the book before print. The book adopted a form of Seonjangbon(線裝本) of Ochimanjeongbeop(五針眼訂法) and was urgently needed some measures to preserve because it has been much damaged by stains, loss and oxidation due to moisture on the bottom of it. In addition, a scientific investigation was applied to find out the features of the quality of paper and fiber used for the book, which would be reflected in the process of the preservation. The characteristics of paper were measurmented for size(cm), thickness(mm), weight(g), basis weight($g/m^2$), density($g/cm^3$), chain line and laid lines($3{\times}3cm$). The measurement showed that the characteristics of paper used in royal books published in the late Joseon Dynasty. For the paper-fiber of the book, C stain was used and the technique revealed that the book is made of bast fibre of paper mulberry and its binding strings are cotton. SEM-EDS analysis was performed to verify the existence of additives in paper. As a result of the analysis, The crystallized calcium was detected in addition to the main components carbon(C) and oxygen(O). This artifact is the unique final version of "The collection of Yi Chungmugong", which has considerable value in terms of academic research, besides it helps to understand how to print books of Joseon Dynasty. And it also has a very accurate information of when and where the book was made, which primarily could be resources to conserve and restore for other book heritage.

• Composites Research
• /
• v.32 no.3
• /
• pp.148-157
• /
• 2019

In this study, $C_f/SiC$, $SiC_f/SiC$ and $C_f-SiC_f/SiC$ ceramic composites reinforcing carbon fiber, SiC fiber and hybrid fiber were fabricated by hybrid TGCVI and PIP process. After the thermal shock cycle, 3-point bending and Oxy-Acetylene torch test, their mechanical behavior, oxidation and erosion resistance were evaluated. The $C_f/SiC$ composite showed a decrease in mechanical property along with increasing temperature, a pseudo-ductile fracture mode and a large quantity of erosion. The $SiC_f/SiC$ composite exhibited stronger mechanical property and lower erosion rate compared to the $C_f/SiC$, but brittle fracture mode. On the other hand, hybrid type of $C_f-SiC_f/SiC$ composite gave the best mechanical property, more ductile failure mode than the $SiC_f/SiC$, and lower erosion rate than the $C_f/SiC$. During the Oxy-Acetylene torch test, the $SiO_2$ formed by reaction of the SiC matrix with oxygen prevented further oxidation or erosion of the fibers for $C_f-SiC_f/SiC$ and $SiC_f/SiC$ composites particularly. In conclusion, if a hybrid composite with low porosity is prepared, this material is expected to have high applicability as a high temperature thermo-structural composite under high temperature oxidation atmosphere by improving low mechanical property due to the oxidation of $C_f/SiC$ and brittle fracture mode of $SiC_f/SiC$ composite.

• Korean Journal of Heritage: History & Science
• /
• v.49 no.1
• /
• pp.100-119
• /
• 2016

The concept of "original form" and the principle of "maintaining the original form" take center stage in conservation, management, and promotion of the domestic heritage. Introduced in the 20th century, there were little discussion or deliberation about the concept of "original form" therefore it remains a vague and somewhat abstract notion subject to individual interpretation. Without a specified practical meaning, "maintaining the original form" became the fundamental principle for heritage conservation and management in the 1999 version of the Cultural Heritage Protection Act, engendering difficulties in applying the principle in practice. Conceived as an important first step toward resolving the issues stemming from the indistinct concept of "original form," this paper explores the process through which the concept was introduced to Korea and then established and developed as a legal principle for heritage conservation, management, and promotion. While the examination of the related documents and various cases shows that the development of the concept of "original form" has centered on specific periods and architectural styles, this essay explicates that the notion "original form" is commonly used as a term referring to the form at the earliest possible temporality. It also explains that this view emanates from perceiving heritages not as multivalent objects, but as a material object that exclusively carries aesthetic and, more importantly, historical value, and that comes from the history awareness of the times. This essay suggests that the concept "original form" should be reestablished with full consideration of the diverse values of heritage and diverse forms through which heritage can be expressed. After reviewing the feasibility and practicality of the concept a set of concrete guidelines should be presented for application in practice.

• Korean Journal of Heritage: History & Science
• /
• v.39
• /
• pp.219-242
• /
• 2006

Quantitative analysis and provenance interpretation of the raw materials for the jade (amazonite) excavated from the Asan Sijeonri site were studied. Geology of the Sijeonri site composed mainly of Precambrian metasedimentary rocks and the alluvium ranges extensively. In the site, amazonite jade was excavated in the Bronze Age No. 4 circular-shaped resident site. The jade has a comma-shaped and shows light green color with so much cracks. The jade is silicate mineral of columnar habits that is shown white streak, and has fine cleavages with vitreous luster. As the analytical results, this jade was identified as a feldspar-group mineral gemologically called amazonite that is mineralogically microcline formed to intergrowth of albite and orthoclase. Internal textures of the amazonite present Na-end member of albite coexisting with K-end member of orthoclase that are replaced each other along the cleavages and twin planes with several ${\mu}m$ scales. Therefore, the amazonite is one mineral phase combined with albite and orthoclase by substitution of $Na_2O$ and $K_2O$, respectively. The Danyang are is an unique producing site of amazonite in South Korea, and Gongju Janggimyeon was known as microcline provenance to the utmost area from the Sijeonri site. In the marginal area of southern coast in Korean Peninsula, Bronze Age amazonite has been excavated in several sites, where original provenance of the raw amazonite is not identified. The Sijeonri site does not show any facilities of producing and processing traces for amazonite jade. Also, only one jade was collected in the Sijeonri site. Therefore, there is not possibility that the provenance of raw jade is the Sijeonri area. To explain original provenance of the amazonite jade, migration path, manufacturing process and archaeological interpretation are required.

• Journal of the Society of Disaster Information
• /
• v.15 no.3
• /
• pp.440-449
• /
• 2019

Purpose: Fire-fighting organizations are the very first agencies that take actions at a disaster scene, and emergency rescue training is carried out for prompt and systematic response. However, there is a need for a change due to the limitations in emergency rescue trainings such as perfunctory trainings or trainings without considering regional or environmental characteristics. Method: This study is to conduct theoretical review with regard to emergency rescue training and present a measure to improve the emergency rescue training through attitude survey targeting fire-fighting organizations in Gangwon area. Result: Facilities that cause difficulties when doing emergency rescue activity were mostly hazardous material storage and processing facilities. In terms of the level of emergency rescue and response task, most respondents answered that the emergency rescue was insufficient. The respondents answered that the effectiveness of emergency rescue training was helpful, but some responses showed that the training was not helpful because of scenario-based training, seeming training, similar training carried out every year, unrealistic training, and lack of competent authorities' interest and perfunctory participations. Most respondents answered for the appropriateness of emergency rescue training and evaluation that they were satisfied, however, they were not satisfied with the evaluation methods irrelevant to the type of training, evaluation methods requiring unnecessary training scale, and evaluation methods leading perfunctory participations of competent authorities. Lastly, respondents mostly answered that training reflecting various damage situations are necessary regarding the demand on the improvement of emergency rescue training. Conclusion: The improvement measures for emergency rescue training are as follows. First, it is necessary to set and prepare various training contents in accordance with regional characteristics by reviewing major disasters occurred in the region. Second, it is necessary to revise the emergency rescue training guidelines and manuals for appropriate training plan for each fire station, provide education and training for working-level staff members, and establish training in a way that types, tactics, and strategies of emergency rescue training could be utilized practically. Third, it is necessary to prepare a scheme that can lead participation and provide incentive or penalty from the planning stage of training in order to increase the participation of supporting and competent authorities when an actual disaster occurs. Fourth, it is necessary to establish support arrangements and cooperative systems by authority through training by fire stations or zones in preparation for disaster situations that may occur simultaneously. Fifth, it is necessary to put emphasis on the training process rather than the result for emergency rescue training and evaluation, pay attention to the identification of supplement points for each disaster situation and make improvements. Especially, type or form of training should be considered rather than evaluating the execution status of detailed processes, and the evaluation measure that can consider the completeness (proficiency) of training and the status of role performance rather than the scale of training should be prepared. Sixth, type and method of training should be improved in accordance with the characteristics of each fire station by identifying the demand of working-level staff members for an efficient emergency rescue training.

• Clean Technology
• /
• v.27 no.2
• /
• pp.198-204
• /
• 2021

This study focused on a two-step process using heterogeneous catalysts to produce biodiesel using Nepalese jatropha oil as a raw material. As a first step, the effect of the repetitive regeneration number of Amberlyst-15 on the esterification reaction of FFA in jatropha oil was investigated. Second, the possibility of a transesterification reaction scale-up using a dolomite bead catalyst was tested. Using 120 kg of jatropha seeds from Nepal, 30 L (27 kg) of jatropha oil was obtained, and the jatropha oil yield from the seeds was about 25.0 wt%. The acid value and FFA content of jatropha oil were measured to be 11.3 mgKOH g^-1 and 5.65%, respectively. As a result of the esterification reaction of jatropha oil using the Amberlyst-15 catalyst in the form of beads, the acid value of the reaction product could be lowered to 0.26 mgKOH g^-1 when the fresh Amberlyst-15 catalyst was used. As the regeneration of the Amberlyst-15 catalyst is repeated, the catalyst has been deactivated, and the esterification reaction performance has deteriorated. The cause of the deactivation seems to be due to the catalyst being broken and impurities being deposited. It was confirmed that the Amberlyst-15 catalyst could be reused up to 5 times for the esterification reaction of jatropha oil. In the second step, the transesterification reaction, a dolomite catalyst, was mass-produced and used in the form of beads. By transesterifying the pretreated jatropha oil in a spinning catalyst basket reactor equipped with 90 g of dolomite bead catalyst, 89.1 wt% of biodiesel yield was obtained in 2 hours after the start of the reaction, which was similar to the transesterification of soybean oil under the same conditions.

• Communications of Mathematical Education
• /
• v.35 no.2
• /
• pp.173-191
• /
• 2021

This study noted that a survey of teachers in a leading study conducted in Korea during the Pandemics period pointed out that the "real-time interactive" classes account for a significantly small portion of the remote class format. Contentually, the study reported cases of developing and applying "real-time interactive" class materials based on "planar decision requirements" of high school mathematics subject geometry. The teacher who participated in the development was a math teacher who worked at a Seoul-based high school with 28 years of high school teaching experience, and a teacher who was in charge of geometry in the math department in 2020. The development teacher decided to develop real-time interactive classes. In particular, the materials were developed by organizing the class guidance plan in four stages: 'Meeting and Class Guidance', 'Giving motivation', 'Suggesting tasks', 'Individual Investigative Activities and Teacher Feedback' and 'Reflection and Evaluation' which were selected through the process of selecting the class contents and selecting online class tools. At this time, the development teacher produced and presented about five minutes of video material using the videooscribe, a whiteboard animation program. And in case of task number 8, it consisted of recording the students' free thoughts after class, which served as a role of assessment by students themselves and providing feedback to their teachers. This study is a case study that introduces a series of courses in which field teachers develop class materials, and in addition to presenting class materials that can be applied directly to classes, is a result of a study that focuses on the role of presenting samples for future class data development. The materials developed were verified as class materials based on the opinions of the students who participated in the class and the results of the evaluation commissioned by the three math teachers.

• Journal of The Korean Association For Science Education
• /
• v.41 no.2
• /
• pp.115-131
• /
• 2021

As the global climate change emergency is escalating, the need for 'Social Action-Oriented SSI (SAO-SSI) on climate change topics' in science education that can change society through social activity is increasing. By employing sociocultural theory, this study explores the challenges of limiting teacher's agency in implementing SAO-SSI on climate change topics in science education. Data from participant observation for 46 lessons, in-depth interviews with participants, field notes, and teacher reflection notes were analyzed by the structure of into micro- (classrooms), meso- (school), and macro- (Korea society) level. At the micro-level, the teacher's new attempts of SAO-SSI on climate change topics class made it difficult for him to identify students' understanding of climate change, because they have a low sense of perception that climate change is also their problem. In addition, the teacher had difficulties leading students' into an engagement for social action because students were skeptical about the feasibility of planned social behavior by positioning themselves as children or had difficulty in understanding social action and sympathizing with its values. At the meso-level, a school culture that encourages the implementation of a curriculum similar to that of colleagues, it was difficult to implement one's own curriculum. And it was difficult to develop expertise without the support and communications with colleagues who revealed the burden of unfamiliar science topics of climate change. In addition, conflicts arose in the process of implementing out-of-school social actions with the principal's passive support. At the macro-level, the insufficient proper material resources for SAO-SSI on climate change topics class, and negative perceptions on the students' social action in the society were acting as constraints. We offer implications for what kind of structural support and efforts from various subjects in the educational community should be provided to implement SAO-SSI on climate change topics class in science education.

• Korean Journal of Heritage: History & Science
• /
• v.54 no.1
• /
• pp.52-69
• /
• 2021

The transcriptions of Buddhist sutra in the Goryeo Dynasty are more elaborate and splendid than those of any other period and occupy a very important position in Korean bibliography. Among them, the transcriptions made on indigo paper show decorative features that represent the dignity and quality that nobles would have preferred. Particularly, during the Goryeo Dynasty, a large number of transcriptions were made on indigo paper, often in hand-scrolled and folded forms. If flexibility was not guaranteed, the hand-scrolled form caused inconvenience and damage when handling the transcription because of the structural limitations of the material that is rolled up and opened. It was possible to overcome these shortcomings by changing from the hand-scrolled to the folded form to obtain convenience and structural stability. The folded form of the transcription utilizes the same principle as the folding screen, so it is a structure that can be folded and unfolded, and it is made by connecting parts at regularly spaced intervals. No matter how small the transcription is, if it is made of thin paper, it is difficult to handle it and to maintain its shape and structure. For this reason, the folded transcription was usually made of thick paper to support the structure, and the cover was made thicker than the inner part to protect the contents. In other words, the forded form was generally manufactured to suit the characteristics of maintaining strength by making the paper thick. Because a large amount of indigo paper was needed to make this type of transcription, it is assumed that there were craftsmen who were in charge only of dark dyeing the papers. Usually, paper dyeing requires much more dye than silk dyeing, and dyeing dozens of times would be required to obtain the deep indigo color of the base of the transcription of Buddhist sutra in the Goryeo Dynasty. Unfortunately, there is no record of the Goryeo Dynasty's indigo blue paper manufacturing technique, and the craftsmen who made indigo paper no longer remain, so no one knows the exact method of making indigo paper. Recently, Hanji artisans, natural dyers, and conservators attempted to restore the Goryeo Dynasty's indigo paper, but the texture and deep colors found in the relics could not be reproduced. This study introduces the process of restoring indigo paper in the Goryeo Dynasty through collaboration between dyeing artisans, Hanji artisans, and conservators for conservation of the transcription of Buddhist sutra in the late Goryeo dynasty, yielding a suggested method of making indigo paper.

• Conservation Science in Museum
• /
• v.24
• /
• pp.1-16
• /
• 2020

This paper presents the process of re-conservation and the results of research on the production method of the Iron Sword with Ring Pommel with Three-Pointed Leaf Decoration, one of the excavation findings from Tomb No. 55 in the Dalseong Ancient Tomb Complex in Daegu. This iron sword is a double weapon with two large swords housed within a single sheath. Four smaller swords are attached to the surface of the sheath, two on the upper portion and the other two below. It is the only such two-in-one weapon excavated intact thus far from an ancient Korean tomb. The records show that it underwent conservation treatment twice in the past. In this study, it was subjected to conservation treatment again to replace the stiffener in some cracking areas, and its material, composition, and production method were analyzed by CT, XRF analysis, and stereoscopic microscopy. The sword is mainly made of copper, but the golden component contains both gold and mercury, which suggests that the copper was plated in gold using mercury amalgamation. The examination of the production methods indicates that it was intended more to demonstrate the authority of its owner rather than to serve any practical use. The two upper small swords on the sheath were made in the same manner as the main swords, and the two small lower swords were cut from a single metal sheet. The sheath was made by cutting two metal sheets. Supports were used to attach the two small swords to the upper portion of the sheath, while the lower portion of the sheath was slit to allow the other two small swords to be inserted into it. The ring pommels of the main swords have a three-pointed leaf decoration. As for the other designs, the handle of the main sword features a series of semicircles, the decorative bands on the sheath have waves in dots, and the fish tail of the sheath shows diagonal lines of dots.