• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.3
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• pp.15-25
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• 2023

In this study, silicon sludge from semiconductor dicing process is recycled to fabricate silica nanoparticles, which are applied as dispersing materials for electro-responsive (ER) smart fluid. In specific, metal impurities are removed from silicon sludge by acid washing to obtain the high-purity silicon powder. And then, silica nanoparticles are synthesized by facile hydrothermal method employing the silicon powder as reactant material. To control the size of silica nanoparticles, the reaction time of hydrothermal method is varied as 8, 15, 20, and 30 hours are applied to control the size of silica nanoparticles. Sizes of silica nanoparticles are increased proportionally to the reaction time owing to the increased numbers of hydrolysis and condensation reactions. As-synthesized silica nanoparticles are prepared as electro-responsive smart fluids by dispersing into silicon oil. Silica nanoparticles synthesized by 30 hours of hydrothermal reaction (SiO₂-H30) exhibit the highest shear stress of 21.4 Pa under an applied electric field strength of 3.0kV mm^-1. Such enhancement in ER performance of SiO₂-H30 among various silica nanoparticles are attribute to the reinforcing effect originated from the mixed particle size, which allowing the formation of rigid chain-like structures. Accordingly, this study successfully propose a recycling method of silicon sludge to synthesize silica nanoparticles and their derived ER fluids, which may suggest new possibility to ESG management emphasizing the eco-friendliness.

• Journal of the Daesoon Academy of Sciences
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• v.28
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• pp.103-131
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• 2017

As the establishment of self-identity is based on 'Relationships of Mutual Beneficence,' the formation of 'Relationships of Mutual Beneficence' is the only road to the security and confirmation of self-existence. But given that our ordinary life almost entirely consists of actions objectifying others, the formation of 'Relationships of Mutual Beneficence' is by no means easy. The formation of 'Relationships of Mutual Beneficence' should be based on morality, controlling self-desire, and not objectifying others. Philosophy based on a priori reasoning describes self-control over selfdesire as the domination of the body through a priori reasoning. But this practical philosophy cannot present a self-evidential internal motivation behind moral actions. Due to this, the application of moral order given by a priori reasoning in response to reality is likely to be reinterpreted on basis of self-interest. With regards to this, the 'propensity towards sympathy' is given as new moral norm. The 'propensity towards sympathy' as emotion is direct and consistent given that feeling occurs prior to thinking. The 'propensity towards sympathy' is intuitive in the sense that it is an instinctual response preceeding a reasoned judgment. The 'propensity towards sympathy,' as a natural moral emotion, is self-validating given that all human beings know it and practice it. But previous studies on the 'propensity towards sympathy' have an obvious limitation because they adopt phenomenological approaches to the 'propensity towards sympathy' which eschew the investigation of morality. Though they present the 'propensity towards sympathy' as a natural emotion based on body rather than reason, they do not philosophically explain the 'propensity towards sympathy.' Thus the 'propensity towards sympathy' as a natural moral emotion is likely to be interpreted as a subjective and relative moral norm. This paper philosophically explains that the 'propensity towards sympathy' is a universal moral norm on the basis of Merleau-Ponty's 'flesh.' 'Flesh' is formed as the entanglement between oneself and others and presents the 'propensity towards sympathy' as its philosophical basis. In other words, 'flesh' formed as the mixture or entanglement between oneself and others is the material foundation upon which one can activate the 'propensity towards sympathy.' This paper's approach to the 'propensity of sympathy' can be desribed as a phenomenological approach to the 'propensity towards sympathy' as a universal moral norm.

• (The) Research of the performance art and culture
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• no.19
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• pp.161-190
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• 2009

This study presents matters of how to analyse the dance of artistic form on the course of transforming folk art to be separated from leisure to become the art form. In particular, the traditional art of dance in Korea has been of collective act like dureh, rather than of individual art, that it had to choose the repeated style of same form and rhythm. In this respect, before it can be said that the dance in its own form became more sophisticated and adopted the artistic segment in the time of modernisation, it is viewed that in the very heart of folk dance there was sufficient ability of artistic material to seek its own right. In this regard, the artistic transformation of seoljanggo nori into seoljanggo dance is an art form which is found in Korea, and expressing rhythm and playfulness is evident and sought attention. Therefore this study puts its importance in analysing how, in the aspect of the course of life of traditional arts, dance is formed in its own right and developed a form of art from fun entertainment. I have chosen, among them, seoljanggo, which used to be a form of fun entertainment and later transformed into a form of art on stage, in particular LeeGyeongh wa seoljanggo dance which maintains the style of Honam Udo farmers' music, and tried to read the text from it. It has resulted in that, Lee Gyeonghwa seoljanggo dance did a new try on tradition, in its development of expressing art through dance and onto more technical sophistication, found in the style of tune and choreography fused into its distinctive form. The art of traditional dance concerns here that seoljanggo has changed from agrarian entertainment to modern stage art, which shows how tradition can be adopted to the contemporary cultural life or to be reinvented to the needs of the aesthetic style that the current society consumes. Thus, it is necessary to think about its role in education and to represent cultural creativity from local developments.

• Korean Journal of Heritage: History & Science
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• v.56 no.2
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• pp.80-98
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• 2023

In the late Joseon Dynasty, when the bride would ride a palanquin when she went to live with her in-laws, it was a custom to cover the palanquin with tiger skin to ward off misfortunes that may come her way. The higher classes used tiger skin or leopard skin for this purpose, but the common people had to substitute this expensive item with a tiger pattern painted on a blanket. Such blankets were called hotanja, hogu, hoguyok and the like. The term "hotanja" is a pure Korean word. It is not known when the cover for the bridal palanquin was first used, but it was popular from the end of the 19^th century and then gradually disappeared. This is due to the introduction of new Western style weddings that eliminated the need for a bridal palanquin. The tiger print blanket was used not only to cover the bride's palanquin but also to cover a table or floor during the wedding ceremony. This study ran a material analysis on nine pieces of tiger print blankets. All of the blanket artifacts examined in this study had an outer cover and a lining made of fabric that used cotton thread for the warp and wool thread for the weft. Two kinds of wool were found in the weft thread in the outer covers: fat-tailed sheep hair from China and goat hair for carpets from the Hebei province, China. Records show that "blankets with painted tiger patterns" were imported from Russia, and the imported blankets were from Russia and China. The outer cover can be categorized into six types, and the lining into three types depending on the weave and direction of the thread twist. The hem facing can be divided into four types. The lining and outer cover use the full width of the fabric, which was woven in wide widths of 135 cm or wider. The tiger pattern on the blanket was made by stenciling. The stencil design of the body and tail of the tiger were placed on a red blanket to be painted in white, and then the background color of the tiger, which is yellow, would be painted over the white, and then black stripes would be added. The pattern of the tiger varies, which shows that the blankets were made by various craftspeople. The pattern of the tiger print blanket is usually of a tiger lying down, but there were tiger print blankets with a tiger standing up. The pattern of the tiger grew smaller over time, and flower patterns were added in the background. Decorative elements were gradually added to the tiger print blanket patterns, but its function as a palanquin cover became lost. By taking the features of tiger print blankets into consideration, it can be assumed that there are imported pieces among the remaining pieces, and were produced in various places because it was popular at that time.

• Journal of The Korean Association For Science Education
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• v.43 no.3
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• pp.209-223
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• 2023

This study was conducted to evaluate the effectiveness of a polar literacy education program for elementary and middle school students, and to derive implications for new education to respond to climate change. We developed modular education programs based on the seven principles of polar literacy established by the Polar-ICE team. We divided them into two courses, one emphasizing science concepts and another emphasizing humanities and sociological issues. We then selected and structured detailed programs suitable for the two courses. These two courses were applied to 26 elementary and middle school students for approximately 69 hours in a Saturday science class hosted by the Department of Science Education at a university in Seoul. The 26 students were divided into three groups. Two groups completed the science education program for polar literacy and a humanities and social studies education program for polar literacy, respectively. The third group, the control group, received general science education unrelated to polar literacy. Before and after running the programs, all three groups responded to a polar literacy test and questionnaires that used vocabulary and presented scenes associated with polar regions. The test results were expressed using Wilcoxon signed ranks, which is a non-parametric test method, and improvements made upon completion of the program were analyzed. From a cognitive aspect, all three groups showed improvement after completing the program in the knowledge area; however, the experimental groups showed a greater degree of improvement than the control group, and there was a clear difference in the contents or materials explicitly covered. From an affective aspect, the difference between before and after the program was minor, but the group that focused on humanities and social issues showed a statistically significant improvement. Regarding changes in polar imagery, the two experimental groups tended to diverge from monotonous images to more diverse images compared to the control group. Based on the above results, we suggested methods to increase the effectiveness of polar literacy education programs, the importance of polar literacy as appropriate material for scientific thinking and earth system education, measures to improve attitudes related to the polar region, and the need to link to school curriculums.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.565-575
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• 2009

In recent years, there have been numerous explosion-related accidents due to military and terrorist activities. Such incidents caused not only damages to structures but also human casualties, especially in urban areas. To protect structures and save human lives against explosion accidents, better understanding of the explosion effect on structures is needed. In an explosion, the blast load is applied to concrete structures as an impulsive load of extremely short duration with very high pressure and heat. Generally, concrete is known to have a relatively high blast resistance compared to other construction materials. However, normal strength concrete structures require higher strength to improve their resistance against impact and blast loads. Therefore, a new material with high-energy absorption capacity and high resistance to damage is needed for blast resistance design. Recently, Ultra High Strength Concrete(UHSC) and Reactive Powder Concrete(RPC) have been actively developed to significantly improve concrete strength. UHSC and RPC, can improve concrete strength, reduce member size and weight, and improve workability. High strength concrete are used to improve earthquake resistance and increase height and bridge span. Also, UHSC and RPC, can be implemented for blast resistance design of infrastructure susceptible to terror or impact such as 9.11 terror attack. Therefore, in this study, the blast tests are performed to investigate the behavior of UHSC and RPC slabs under blast loading. Blast wave characteristics including incident and reflected pressures as well as maximum and residual displacements and strains in steel and concrete surface are measured. Also, blast damages and failure modes were recorded for each specimen. From these tests, UHSC and RPC have shown to better blast explosions resistance compare to normal strength concrete.

• Journal of Korea Entertainment Industry Association
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• v.13 no.5
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• pp.263-271
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• 2019

The recent phenomenon of job "Miss Match", which is inconsistent with knowledge in the demand of educational training institutes and industries, has spread to an increase in private education costs for reeducation and employment of new hires, resulting in weak individual job competency and poor employment capability, as well as economic and material waste at the national level. To compensate for these problems, the National Competency Standards(NCS), which are available immediately in practice and look for a standard point of national job competency with the aim of fostering human resources sought by industries, were developed, and even the NCS-based qualification system was launched in line with the stream of times. This study is intended to look into the importance and priority of competency units and competency unit elements at the NCS-based qualification L3 level in the skin care field for an overall check of the NCS-based qualification level at a time when educational institutes are organizing and operating the school curriculums according to the NCS and NCS-based qualification level. And it is attempted to provide basic data for the development of curriculum in fostering professional human resources required by industries. To analyze the needs for competency units and competency unit elements at the L3 level, a survey using AHP method was carried out to a group of field experts and a group of education experts. In addition, the SPSS(Statistical Package for Social Science) ver. 21.0 and Expert Choice 2000, an AHP-only solution was used to do statistical processing through the processes of data coding and data cleaning. The findings showed that there was a partial difference of opinion between a group of field experts and a group of education experts. This indicates that the inconsistencies between educational training institutes and industrial sites should be resolved at this time of change with the aim of fostering field customized human resources with professional skills. Consequently, the solution is to combine jobs at industrial sites and standardized educations of educational institutes with human resources required at industrial sites.

• Korean Journal of Heritage: History & Science
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• v.57 no.2
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• pp.144-166
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• 2024

The Cultural Heritage Committee is an important organization that has been deliberating on important matters related to the preservation of cultural properties in the Republic of Korea for more than 60 years since 1962. The Cultural Heritage Preservation Committee was active in 1961, which was a short period of about a year, but the minutes prepared at the time confirmed that it had the following meanings. First of all, legally, it was meaningful in that the concept of cultural property or intangible cultural property was used for the first time in Korea in laws and regulations on the term of office of professional members. These matters became the basis for the operation of the current Cultural Heritage Protection Act and the Cultural Heritage Committee. The following confirms that, unlike previously known activities, they were active despite political upheaval at the time. In spite of rapid regime change at the time, the committee had no change in its members, and the meetings continued without interruption. At that time, there was an exclusive relationship between different groups in relation to the preservation of cultural heritage, and this relationship was confirmed by the minutes that disappeared with the establishment of the Cultural Heritage Management Bureau, which integrated these groups. Finally, the form of the minutes prepared then shows the form of documentation at the time, where it is confirmed that the traditional documentation format is changing into a new form. It can be good research material in terms of modern and contemporary bibliography. As discussed earlier, the Cultural Heritage Conservation Committee of 1961 has historical significance in terms of legal and actual activities. The reason why the committee's activities were low valued is presumed to be that the minutes and related documents prepared at the time were not organized well due to the lack of a related administrative system. The minutes of the Cultural Heritage Conservation Committee record various facts about cultural heritage policies and decisions at that time. Therefore, analysis and research on these contents can reveal more facts about the cultural heritage policies and perceptions of that time.

• Economic and Environmental Geology
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• v.57 no.3
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• pp.281-292
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• 2024

North Korea relies heavily on coal as the primary energy source, playing an important role in all energy demand sectors except for the transportation sector. Approximately half of the total electricity is generated through coal-fired power plants, and coal is used to produce heat and power for all industrial facilities. Furthermore, coal has been a significant contributor to earning foreign currency through long-term exports to China. Nevertheless, since the 1980s, indiscriminate mining activities have led to rapid depletion of coal production in most coal mines. Aging mine facilities, lack of investment in new equipment, shortages of fuel and electricity, difficulties in material supply, and frequent damage from flooding have collectively contributed to a noticeable decline in coal production since the late 1980s. North Korea's coal deposits are distributed in various geological formations from the Proterozoic to the Cenozoic, but the most critical coal-bearing formations are Ripsok and Sadong formations distributed in the Pyeongnam Basin of the Late Paleozoic from Carboniferous to Permian, which are called as Pyeongnam North and South Coal Fields. Over 90% of North Korea's coal is produced in these coal fields. The classification of coal in North Korea differs from the international classification based on coalification (peat, lignite, sub-bituminous coal, bituminous coal, and anthracite). North Korean classification based on industrial aspect is classified into bituminous coal, anthracite, and low-grade coal (Chomuyeontan). Based on the energy factor, it is classified into high-calorie coal, medium calorie coal, and low-calorie coal. In North Korea, the term "Chomuyeontan" refers to a type of coal that is not classified globally and is unique to North Korea. It is a low-grade coal exclusively used in North Korea and is not found or used in any other country worldwide. This article compares North Korea's coal classification and the international coal classification of coal and provides insights into the geological characteristics, reserves, utilization, and research trends of North Korean coal resources. This study could serve as a guide for preparing scientific and industrial agendas related to coal collaboration between North Korea and South Korea.

• Journal of Korean Neurosurgical Society
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• v.30 no.10
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• pp.1210-1219
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• 2001

Introduction : The purpose of this study was to analyze the safety, pullout strength and radiographic characteristics of unicortical and bicortical screws of cervical facet within cadaveric specimens and evaluate the influence of level of training on the positioning of these screws. Methods : Twenty-one cadavers, mean 78.9 years of age, underwent bilateral placement of 3.5mm AO lateral mass screw from C3-C6(n=168) using a slight variation of the Magerl technique. Intraoperative imaging was not used. The right side(unicortical) utilized only 14mm screws(effective length of 11mm) while on the left side to determine the length of the screw after the ventral cortex had been drilled. Three spine surgeons(attending, fellow, chief resident) with varying levels of spine training performed the procedure on seven cadavers each. All spines were harvested and lateral radiographs were taken. Individual cervical vertebrae were carefully dissected and then axial radiographs were taken. The screws were evaluated clinically and radiographically for their safety. Screws were graded clinically for their safety with respect to the spinal cord, facet joint, nerve root and vertebral artery. The grades consisted of the following categories : "satisfactory", "at risk" and "direct injury". Each screw was also graded according to its zone placement. Screw position was quantified by measuring a sagittal angle from the lateral radiograph and an axial angle from the axial radiograph. Pull-out force was determined for all screws using a material testing machine. Results : Dissection revealed that fifteen screws on the left side actually had only unicortical and not bicortical purchase as intended. The majority of screws(92.8%) were satisfactory in terms of safety. There were no injuries to the spinal cord. On the right side(unicortical), 98.9% of the screws were "satisfactory" and on the left side(bicortical) 68.1% were "satisfactory". There was a 5.8% incidence of direct arterial injury and a 17.4% incidence of direct nerve root injury with the bicortical screws. There were no "direct injuries" with the unicortical screws for the nerve root or vertebral artery. The unicortical screws had a 21.4% incidence of direct injury of the facet joint, while the bicortical screws had a 21.7% incidence. The majority of "direct injury" of bicortical screws were placed by the surgeon with the least experience. The performance of the resident surgeon was significantly different from the attending or fellow(p<0.05) in terms of safety of the nerve root and vertebral artery. The attending's performance was significantly better than the resident or fellow(p<0.05) in terms of safety of the facet joint. There was no relationship between the safety of a screw and its zone placement. The axial deviation angle measured $23.5{\pm}6.6$ degrees and $19.8{\pm}7.9$ degrees for the unicortical and bicortical screws, respectively. The resident surgeon had a significantly lower angle than the attending or fellow(p<0.05). The sagittal angle measured $66.3{\pm}7.0$ degrees and $62.3{\pm}7.9$ degrees for the unicortical and bicortical screws, respectively. The attending had a significantly lower sagittal angle than the fellow or resident(p<0.05). Thirty-three screws that entered the facet joint were tested for pull-out strength but excluded from the data because they were not lateral mass screws per-se and had deviated substantially from the intended final trajectory. The mean pull-out force for all screws was $542.9{\pm}296.6N$. There was no statistically significant difference between the pull-out force for unicortical($519.9{\pm}286.9N$) and bicortical($565.2{\pm}306N$) screws. There was no significant difference in pull-out strengths with respect to zone placement. Conclusion : It is our belief that the risk associated with bicortical purchase mandates formal spine training if it is to be done safely and accurately. Unicortical screws are safer regardless of level of training. It is apparent that 14mm lateral mass screws placed in a supero-lateral trajectory in the adult cervical spine provide an equivalent strength with a much lower risk of injury than the longer bicortical screws placed in a similar orientation.