• Journal of agriculture & life science
• /
• v.44 no.5
• /
• pp.1-8
• /
• 2010

In this study, eco-friendly hybrid composite boards were manufactured from green tea and wood fibers for application as interior materials with various functionalities of green tea and strong strength properties of wood fibers. In this relation, the effect of green tea content on the static bending strength performances of these green tea and wood fibers composite boards were investigated. Static bending strengths of hybrid composite boards were lower than those of control boards and decreased with the increase of green tea content. Also, the strength performances appeared to be somewhat different by resin type used for board manufacture. The hybrid composite boards manufactured from $E_1$ grade urea resin adhesive, which has higher molar ratio of formaldehyde to urea than that of $E_0$ grade one, were 1.08~1.53 times higher in bending modulus of elasticity (MOE) and 1.19~1.82 higher in modulus of rupture (MOR) than that manufactured from $E_0$ grade. And, the differences of MOE and MOR between hybrid composite boards manufactured from $E_0$ grade and $E_0$ grade urea resin adhesive increased with the increase of green tea content. In the case of hybrid composite boards manufactured from $E_1$ grade urea resin adhesive, the MOR was within 0.94~1.03 times the commercial medium density fiberboard. Thus, it was thought that eco-friendly hybrid composite boards with various functionalities and strong strength performances could be manufactured from green tea and wood fibers.

• Journal of Conservation Science
• /
• v.35 no.6
• /
• pp.652-663
• /
• 2019

To identify daily and annual changes in outdoor airborne fungi, it is necessary to shorten the collection cycle and increase the number of measurements. In this study, measurements were performed by employing an air sampler and potato dextrose agar media on the rooftop of National Research Institute of Cultural Heritage during a period of one year (August 2018 to July 2019). The collection cycle spanned the twenty-four seasonal divisions and the collection time was 2 p.m. and 11 p.m.. Meteorological elements were collected at intervals of one hour. Furthermore, the concentration of airborne fungi was monitored and correlation analysis with meteorological elements was subsequently conducted. Obtained results indicate that the concentration of airborne fungi is found to be highest in November, autumn, night, followed by autumn, summer, winter, and spring. The concentration, type, and dominant species of airborne fungi can vary depending on factors such as rainfall, typhoons, and yellow dust (fine dust). The concentration of airborne fungi indicates a strong positive linear relationship between precipitation, number of precipitation days, and relative humidity. The concentration of airborne fungi was related to the period of increase of dead plants in terms of nutrition source, and to the high relative humidity conditions including rainfall in terms of meteorological elements.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.4
• /
• pp.381-386
• /
• 2022

The purpose of this study is to investigate the conditions for improving space use and satisfaction by examing the behavior, focusing on the senior center, one of the leisure welfare facilities for the older adults. An online survey was conducted on 300 older adults aged 65 years old (104 males, 196 females) who had experience using senior centers. The results are as follows. First, the frequency of use per older adults was 1-3 times a month the most, and the preferred frequency of use was 1-3 times a week. The results showed that they wanted to use the Senior center frequently, but they could not use it often. Considering the high preference for health promotion activity programs in senior centers, it is understood that the use of space programs for health promotion can be increased if provided. Second, as the usage time per route ranges from a minimum of 1 hour to a maximum of 5 hours, it is considered that satisfaction and usability can be improved if a space to support various personal activities is provided. Third, it is considered to be helpful to improve the program or space composition that can strengthen friendship or improve accessibility by appearing as difficulties in friendship and accessibility for the reasons not used per senior citizen.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.43 no.5
• /
• pp.667-674
• /
• 2023

In the event of a disaster occurring within a building, the prompt and efficient evacuation and rescue of occupants within the building becomes the foremost priority to minimize casualties. For the purpose of such rescue operations, it is essential to ascertain the distribution of individuals within the building. Nevertheless, there is a primary dependence on accounts provided by pertinent individuals like building proprietors or security staff, alongside fundamental data encompassing floor dimensions and maximum capacity. Consequently, accurate determination of the number of occupants within the building holds paramount significance in reducing uncertainties at the site and facilitating effective rescue activities during the golden hour. This research introduces a methodology employing computer vision algorithms to count the number of occupants within distinct building locations based on images captured by installed multiple CCTV cameras. The counting methodology consists of three stages: (1) establishing virtual Lines of Interest (LOI) for each camera to construct a multi-camera network environment, (2) detecting and tracking people within the monitoring area using deep learning, and (3) aggregating counts across the multi-camera network. The proposed methodology was validated through experiments conducted in a five-story building with the average accurary of 89.9% and the average MAE of 0.178 and RMSE of 0.339, and the advantages of using multiple cameras for occupant counting were explained. This paper showed the potential of the proposed methodology for more effective and timely disaster management through common surveillance systems by providing prompt occupancy information.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.50 no.6
• /
• pp.110-123
• /
• 2022

Namsan Park in Seoul was designated as a "grand park" in 1954 and is currently operated as an 'Urban Nature Park Area' and four 'neighborhood parks.' However, despite the park's historical and cultural value as an urban park, it has been discussed mainly from a perspective revolving around notions of a mountain or a city wall. To ensure a comprehensive exploration of Namsan Park's history, this study examined public records at the Seoul Metropolitan Archives (SMA), which houses the city's permanent records for preservation and organization. To this end, documents in the SMA Database (DB) were analyzed, yielding 1,359 records concerning Namsan Park. Based on the contents, general characteristics of the urban park were identified through production periods, record types, and disclosure types. Then, essential keywords concerning organizations, people, geographical areas, subjects, and business functions were examined. Finally, the contents and characteristics of Namsan Park in public records were scrutinized, focusing on specific spaces. This research also uncovered important information, such as park drawings, photos, planting lists, plant parcel lists, and significant discussions and decisions regarding the operation and management of the park. Although the public records do not contain a comprehensive history of Namsan Park, it was possible to check the primary historical changes and deliberation processes pertaining to the park's history. Therefore, continuous research intended to interpret and describe public records is expected to identify many implications. In addition, because the public records showed heterogeneous characteristics that center on specific periods and events, an essential task is to advance collaboration and networking with various related institutions, designers, researchers, and citizens.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.12 no.1
• /
• pp.8-16
• /
• 2024

Limestone (CaCO₃, calcium carbonate), which is used as a raw material in the portland cement and steel industry, emits CO₂ through decarbonation by high temperatures in the manufacturing process. To reduce CO₂ emissions by the use of raw materials like limestone, it has been proposed to replace limestone with various industrial by-products that contain CaO but less or none of the carbonated minerals, that cause CO₂ emissions. Loss of Ignition (LOI), Thermogravimetric analysis (TG), and Infrared Spectroscopy (IR) are used to quantitative the amount of CO₂ emission by using these industrial by-products, but CO₂ emissions can be either over or underestimated depending on the characteristics of by-product materials. In this study, we estimated CO₂ contents by LOI, TG, IR and DTG(Differential Thermogravimetric analysis) of calcite(CaCO₃) and samples that contain CO₂ in the form of carbonate and whose weight increases by oxidation at high temperatures. The test results showed for CaCO₃ samples, all test methods have a sufficient level of reliability. On the other hand, for the CO₂ content of the sample whose weight increases at high temperature, LOI and TG did not properly estimate the CO₂ content of the sample, and IR tended to overestimate compared to the predicted value, but the estimated result by DTG was close to the predicted valu e. From these resu lts, in the case of samples that contain less than a few percent of CO₂ and whose weight increases during the temperature that carbonate minerals decompose, estimating the CO₂ content using DTG is a more reasonable way than LOI, TG, and IR.

• Korean Journal of Heritage: History & Science
• /
• v.53 no.4
• /
• pp.234-249
• /
• 2020

The dispute involving the construction of the Tomb of Queen Sindeok (hereinafter "Jeongreung"), King Taejo's wife in Seoul, and the moving of that tomb, represents the most clearly demonstrated case for the collision of new and old ideologies between political powers in the early period of Joseon. Jeongreung, the tomb of Queen Sindeok from the Kang Clan, was built inside the capital fortress, but in 1409, King Taejong forced the tomb to be moved outside the capital, and the stone relics remaining at the original location were used to build the stone bridge, Gwangtong-gyo. In an unofficial story, King Taejong moved the tomb outside the capital and used the stone items there to make the Cheonggyecheon Gwang-gyo so that the people would step upon the area in order to curse Lady Kang. In the final year of King Taejo, Lady Kang and King Taejong were in a politically conflictual relationship, but they were close to being political partners until King Taejo became the king. Sillok records pertaining to the establishment of Jeongreung or Gwangtong-gyo in fact state things more plainly, indicating that the moving of Jeongreung was a result of following the sangeon (a written statement to the king) of Uijeongbu (the highest administrative agency in Joseon), which stated that having the tomb of a king or queen in the capital was inappropriate, and since it was close to the official quarter of envoys, it had to be moved. The assertion that it was aimed at degrading Jeongreung in order to repair Gwangtong-gyo thus does not reflect the factual relationship. This article presents the possibility that the use of stone items from Jeongreung to repair Gwangtong-gyo reflected an emerging need for efficient material procurement that accompanied a drastic increase in demand for materials required in civil works both in- and outside the capital. The cause for constructing Jeongreung within the capital and the cause of moving the tomb outside the capital would therefore be attributable to the heterogeneity of the ideological backgrounds of King Taejo and King Taejong. King Taejo was the ruler of the Confucius state, as he reigned through the Yeokseong Revolution, but he constructed the tomb and Hongcheon-sa, the temple in the capital for his wife Queen Sindeok. In this respect, it is considered that, with the power of Buddhism, there was an attempt to rally supporters and gather the force needed to establish the authority of Queen Sindeok. Yi Seong-gye, who was raised in the Dorugachi clan of Yuan, lived as a military man in the border area, and so he would not have had a high level of understanding in Confucian scholarship. Rather, he was a man of the old system with its 'Buddhist" tendency. On the other hand, King Taejong Yi Bang-won was an elite Confucian student who passed the national examination at the end of the Goryeo era, and he is also known to have held a profound understanding of Neo-Confucianism. To state it differently, it would be reasonable to say that the understanding of symbolic implications for the capital would be more profound in a Confucian state. Since the national system that was ruled by laws had been established following the Three-Kingdom era, the principle of burial outside of the capital that would have seen a grave constructed on the outskirts of the capital was not upheld, without exception. Jeongreung was built inside the capital due to the strong individual desire of King Taejo, but since he was a Confucian scholar prior to becoming king, it would not have been accepted as desirable. After taking the throne, King Taejong took the initiative to begin overhauling the capital in order to reflect his intent to clearly realize Confucian ideology emphasizing 'Yechi' ("ruling with good manners") with the scenic view of the Capital's Hanyang river. It would be reasonable to conclude accordingly that the moving of Jeongreung was undertaken in the context of such a historic background.

• Korean Journal of Heritage: History & Science
• /
• v.53 no.1
• /
• pp.88-105
• /
• 2020

This study examined existing theories of the characteristics of the abandoned tumulus site located at the east side of the Silla era Hwang Bok Sa (皇福寺) site and attempted an archaeological approach based on the derived facts, combining both the results of this study and those of a recently conducted excavation survey. The results of this investigation exhibited the following outcomes. First, the excavation survey revealed that the huge rounded stones discovered on the surface of a rice paddy field located at the east side of the Silla era Hwang Bok Sa were all protecting stones, processed on the front side in the form of a bow, designating a royal tomb. Most of these protecting stones had deviated from their original positions due to subsequent farming practices and some had been re-cycled for construction purposes as fences or foundations for structures built in the Silla era. Considering the prevailing belief in the concept of reincarnation, the bone rank system, and royal authority in the Silla era at that time, it would seem likely that the royal tombs were not intentionally destroyed. Therefore, it is speculated that the stones in this royal tomb were abandoned during construction of the tomb of the King at that time and then naturally re-cycled as building components used in construction sites in later years. Second, this study comparatively analyzed the scale and quality of the supporting stones at the royal tomb site in Guhwang-dong. The analysis results verified that those supporting stones were the same stones from the royal tomb used as supporting stones for statues symbolizing the twelve earthly branch spirits that were restored at the site of the tower at the royal tomb. This confirmed that the statues of the twelve earthly branches spirits sitting at the Hwang Bok Sa site were the protecting stones from a different royal tomb. Accordingly, the conclusion that has been generally accepted to date-that the protecting stones of the statues of twelve earthly branches spirits sitting at Hwang Bok Sa site were probably moved from the royal tomb site in Guhwang-dong-must inevitably be modified. Third, based on the structure of the protecting stones and type of the royal tomb, it is speculated that the individual buried in the royal tomb at Guhwang-dong is one of the kings who followed King Heungdeok and similar times of the buried person of the tomb that was considered as King Gyeongdeok, and who was before the buried person of the tomb that was considered as Kim Yu-sin. In addition, when considering the historical art patterns on the supporting stones of the statues that symbolize the twelve earthly branches spirits, which were moved to the site of the tower at the royal tomb, it is reasonable to believe that the person buried at the royal tomb at Guhwang-dong is likely one of the Kings of the late Silla era of the 9^th century.

• Korean Journal of Heritage: History & Science
• /
• v.52 no.3
• /
• pp.56-73
• /
• 2019

This paper aims to establish the technical style of roof tiles by analyzing East Asian roof tile making techniques. It will examine the existing main research data, such as excavation results and the subsequent analysis of the roof tiles' production traces, as well as references and transmitted techniques. Regions are grouped according to technical similarity, then grouped again by artistic styles of pattern and shape and by the technical styles of tools, procedures, and manpower plans. Accordingly, intends to find out whether an understanding of technical style can facilitate an understanding of not only cultural aspects, but also the causality of techniques. Korean, Chinese and Japanese tools were examined, and procedures for making roof tiles were classified into 4 groups. In a superficial way, China, Okinawa, Korea, and Honshu share similar technical traits. Research of procedural details and manpower plans revealed characteristics of each region. As a result, comparisons were made between each region's technical characteristics attempting to investigate their causes. The groups were classified according to their possessing techniques, but it was revealed that East Asia's shared production techniques were based on architectural methodss. The skill of "Pyeon Jeol(Clay Cutting)" classified according to its possessing techniques, turned out to be one such technique. Also, the procedure of technical localization based on the skill of "Ta-nal(Tapping)" showed that the condition of this technique was the power to localize in response to a transfer of techniques. Previous comparison parameters of artifacts would have been a similarity of style originated from exchanges between regions and stylistic characteristics of regions decided by the demander's taste of beauty. This methodology enlarges cultural perception and affords a positive basis of historical facts. However, it suggests the possibility of finding cultural aspects' origins by understanding the technical style and seeing same result in view of "technology culture."