• Title/Summary/Keyword: Transmission

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A Study on the Performance Verification Method of Small-Sized LTE-Maritime Transceiver (소형 초고속해상무선통신망 송수신기 성능 검증 방안에 관한 연구)

  • Seok Woo;Bu-young Kim;Woo-Seong Shim
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.7
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    • pp.902-909
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    • 2023
  • This study evaluated the performance test of a small-sized LTE-Maritime(LTE-M) transceiver that was developed and promoted to expand the use of intelligent maritime traf ic information services led by the Ministry of Oceans and Fisheries with the aim of supporting the prevention of maritime accidents. Accoriding to statistics, approximately 30% of all marine accidents in Korean water occur with ships weighing less than 3 tons. Therefore, the blind spots of maritime safety must be supplemented through the development of small-sized transceivers. The small transceiver may be used in fishing boats that are active near coastal waters and in water leisure equipment near the coastline. Therefore, verifying whether sufficient performance and stable communication quality are provided is necessary, considering the environment of their real usage. In this study, we reviewed the communication quality goals of the LTE-M network and the performance requirements of small-sized transceivers suggested by the Ministry of Oceans and Fisheries, and proposed a test plan to appropriately evaluate the performance of small-sized transceivers. The validity of the proposed test method was verified for six real-sea areas with a high frequency of marine accidents. Consequently, the downlink and uplink transmission speeds of the small-sized LTE-M transceiver showed performances of 9 Mbps or more and 3 Mbps or more, respectively. In addition, using the coverage analysis system, coverage of more than 95% and 100% were confirmed in the intensive management zone (0-30 km) and interesting zone (30-50 km), respectively. The performance evaluation method and test results proposed in this paper are expected to be used as reference materials for verifying the performance of transceivers, contributing to the spread of government-promoted e-navigation services and small-sized transceivers.

Analyze Technologies and Trends in Commercialized Radiology Artificial Intelligence Medical Device (상용화된 영상의학 인공지능 의료기기의 기술 및 동향 분석)

  • Chang-Hwa Han
    • Journal of the Korean Society of Radiology
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    • v.17 no.6
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    • pp.881-887
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    • 2023
  • This study aims to analyze the development and current trends of AI-based medical imaging devices commercialized in South Korea. As of September 30, 2023, there were a total of 186 AI-based medical devices licensed, certified, and reported to the Korean Ministry of Food and Drug Safety, of which 138 were related to imaging. The study comprehensively examined the yearly approval trends, equipment types, application areas, and key functions from 2018 to 2023. The study found that the number of AI medical devices started from four products in 2018 and grew steadily until 2023, with a sharp increase after 2020. This can be attributed to the interaction between the advancement of AI technology and the increasing demand in the medical field. By equipment, AI medical devices were developed in the order of CT, X-ray, and MR, which reflects the characteristics and clinical importance of the images of each equipment. This study found that the development of AI medical devices for specific areas such as the thorax, cranial nerves, and musculoskeletal system is active, and the main functions are medical image analysis, detection and diagnosis assistance, and image transmission. These results suggest that AI's pattern recognition and data analysis capabilities are playing an important role in the medical imaging field. In addition, this study examined the number of Korean products that have received international certifications, particularly the US FDA and European CE. The results show that many products have been certified by both organizations, indicating that Korean AI medical devices are in line with international standards and are competitive in the global market. By analyzing the impact of AI technology on medical imaging and its potential for development, this study provides important implications for future research and development directions. However, challenges such as regulatory aspects, data quality and accessibility, and clinical validity are also pointed out, requiring continued research and improvement on these issues.

How Did the COVID-19 Pandemic Affect Mobility, Land Use, and Destination Selection? Lesson from Seoul, Korea

  • Lee, Jiwon;Gim, Tae-Hyoung Tommy;Park, Yunmi;Chung, Hyung-Chul;Handayani, Wiwandari;Lee, Hee-Chung;Yoon, Dong Keun;Pai, Jen Te
    • Land and Housing Review
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    • v.14 no.4
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    • pp.77-93
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    • 2023
  • The COVID-19 pandemic has brought about significant social changes through government prevention and control measures, changes in people's risk perceptions, and lifestyle changes. In response, urban inhabitants changed their behaviors significantly, including their preferences for transportation modes and urban spaces in response to government quarantine policies and concerns over the potential risk of infection in urban spaces. These changes may have long-lasting effects on urban spaces beyond the COVID-19 pandemic or they may evolve and develop new forms. Therefore, this study aims to explore the potential for urban spaces to adapt to the present and future pandemics by examining changes in urban residents' preferences in travel modes and urban space use due to the COVID-19 pandemic. This study found that overall preferences for travel modes and urban spaces significantly differ between the pre-pandemic, pandemic, and post-pandemic periods. During the pandemic, preferences for travel modes and urban spaces has decreased, except for privately owned vehicles and green spaces, which are perceived to be safe from transmission, show more favorable than others. Post-pandemic preferences for travel modes and urban spaces are less favorable than pre-pandemic with urban spaces being five times less favorable than transportation. Although green spaces and medical facilities that were positively perceived during the pandemic are expected to return to the pre-pandemic preference level, other factors of urban spaces are facing a new-normal. The findings suggest that the COVID-19 pandemic has had a significant impact on urban residents' preferences for travel modes and urban space use. Understanding these changes is crucial for developing strategies to adapt to present and future pandemics and improve urban resilience.

Importance and requirements for dental prosthesis order platform services: a survey of dental professionals (치과 보철물 거래 플랫폼 서비스의 중요성과 요구사항: 치과 전문가 설문조사)

  • Gyu-Ri Kim;Keunbada Son;Du-Hyeong Lee;So-Yeun Kim;Myoung-Uk Jin;Kyu-Bok Lee
    • Journal of Dental Rehabilitation and Applied Science
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    • v.39 no.3
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    • pp.105-118
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    • 2023
  • Purpose: This study aimed to gain better understanding of the importance of dental prosthesis order platform services and to identify the essential elements for their enhancement and wider adoption among dental professionals. Materials and Methods: A survey was conducted to assess the perspectives of dentists, dental technicians, dental hygienists, and dental industry professionals toward dental prosthesis ordering and associated platform services (a total of 53 respondents). The questionnaire was devised after an expert review and assessed for reliability using Cronbach's alpha coefficient. Factor analysis revealed that 57 factors across five categories accounted for 88.417% of the total variance. The survey was administered through an online questionnaire platform, and data analysis was conducted using a statistical software, employing one-way analysis of variance and Tukey's honestly significant difference test (α = 0.05). Results: The essential elements identified were accurate information input, effective communication, delivery of distortion-free impressions, convenience in data transmission and storage, development of stable and affordable platform services (P < 0.05). Furthermore, significant differences were observed in the importance of these items based on age, dental profession, and career experience (P < 0.05). Conclusion: The dental prosthesis ordering platform services, the requirements of dental personnel were stability, economic efficiency, and ease of transmitting and storing prosthesis data. The findings can serve as important indicators for the development and improvement of dental prosthesis order platform services.

Guanyin Faith in the Hangzhou Area during the Tang and Song Dynasties (당·송대 항주지역의 관음신앙)

  • Kim Sung-soon
    • Journal of the Daesoon Academy of Sciences
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    • v.46
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    • pp.123-152
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    • 2023
  • This paper will examine how the Avalokitesvara faith of India was restructured into the doctrines and practices related to the Sinicized version of the deity as Guanyin (觀音) Bodhisattva. Particular focus will be given to the Hangzhou area of China, when the Guanyin faith was still in the process of gaining establishment in China. In the Hangzhou area, Buddhist Orders grew significantly due to the wealth accumulated from commerce using canals and maritime trade, and the Chan (禪 typically known as Zen in English) Orders were particularly active during the Song Dynasty. Zhiyi (智顗), a prominent master from the Tiantai Order (天台宗), based his activities out of Hangzhou. He composed the text known as the Commentary on the Guanyin Petitioning Sutra (Qingguanyinjing-shu 請觀音經疏) based on a reinterpretation of a scripture related to Guanyin, and he systematized the Guanyin Repentance Ritual (Guanyin-chanfa 觀音懺法) by combining the Doctrines of Tiantai with the Guanyin faith. In addition, Ciyin Zunshi (慈雲遵式) reformulated that Guanyin Repentance Ritual into the Guanyin Petitioning Repentance Ritual (qing-guanyin-chan 請觀音懺) to make it into a common ritual that was more accessible to everyday people. The book, Records Regarding the Personal Conduct of the Chan Master Zhijue (zhijue-chanshi-zixing-lu 智覺禪師自行錄), which is written by Yongming Yanshou (永明延壽), a figure from the Fayan Order (法眼宗), one of the Chan Buddhist orders in the Hangzhou area during the Northern Song Dynasty, reveals the acceptance of the Guanyin faith as a daily practice within the 108 daily rituals (108事). In Chinese Buddhism, there were historical examples of monks being worshipped as incarnations of Guanyin Bodhisattva. An example of this includes iconography depicting Baozhi (寶誌), a figure from Jiliang (濟涼) who lived during the Southern Dynasties, as Ekādaśamukha (十一面觀音, Eleven-faced Guanyin Bodhisattva) in keeping with the belief that he was an incarnation of that deity. Monks of the Tiantai and Chan orders operating in the Hangzhou area actively utilized the transmission of Buddhist tales about Guanyin Bodhisattva as related to monks that exhibited miraculous powers (神異僧). This can be understood as a phenomenon demonstrating how Song Buddhism tried to attract more believers through the popularity of the Guanyin Faith.

Effects of Various Biodegradable Mulching Films on Growth, Yield, and Soil Environment in Soybean Cultivation (콩 재배지에서 다양한 생분해성 멀칭필름 종류별 작물 생육, 수량 및 토양환경에 미치는 영향)

  • Ye-Guon Kim;Yeon-Hu Woo;Hyun-Hwa Park;Do-Jin Lee;Yong-In Kuk
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.69 no.1
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    • pp.34-48
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    • 2024
  • The objective of this study was to evaluate the safety of biodegradable mulching films in soybean (Glycine max) cultivation by measuring their effects on crop growth and yield, film decomposition and soil chemical and physical properties. In 2022 and 2023, plant height, branch number, chlorophyll contents, yield components, and yield of soybean did not vary significantly in areas using PE films and biodegradable mulching films. The light transmission rate of the biodegradable mulching films ranged from 6.4 to 15.8% when measured 112 days after soybean transplanting, and was higher, on average, in 2023 than in 2022. In both years, degradation of the biodegradable mulching films began 20 days after soybean transplantation and increased over time. In addition, remains of biodegradable mulching films were present in fields at soybean harvest and remained until 50 days after harvest. Decomposition rates of the biodegradable mulching films at 112 days after soybean transplanting ranged from 9.8 to 26.7% in 2022 and 13 to 36% in 2023. Although soil pH and EC varied based on the year and timing of measurements, there was no significant difference between areas that used biodegradable mulching films and PE films. Soil organic matter, nitrate and exchangeable cation contents such as Ca, Mg, and K were not significantly different in areas that used both PE films and biodegradable films. However, significantly higher levels of available phosphoric acid content were measured in areas that used biodegradable mulch films E, S, and T. Regardless of which films were used, there were no significant differences in the soil's physical properties. In 2022 and 2023, there was no difference between areas that used biodegradable mulch films and PE films. However, soil temperature in mulched areas was 2℃ higher and soil moisture was 5-15% higher than in non-mulched areas. Barley growth was not affected by being planted in soil that had been used for soybean cultivation with biodegradable films. Therefore, the biodegradable mulch films used in this study can be used without negatively affecting the growth, yield, and soil environment of soybeans.

A Study on the Standardization and Diversification of Chinese Biographies of the Eminent Monks in the 7th and 8th Century (7~8세기 중국 고승전의 정형화와 다양화)

  • Jung Chun-koo
    • Journal of the Daesoon Academy of Sciences
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    • v.48
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    • pp.305-335
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    • 2024
  • In the 7th and 8th centuries, Chinese Buddhism was at its peak, and major sects emerged and began to differ from one another in significant ways. This fact was also revealed through several versions of Biographies of the Eminent Monks and changes observable in the peculiarity of their formats. In the early 6th century, Huijiao (慧皎) compiled Gaosengzhuan (高僧傳, Biographies of Eminent Monks) which contains the history of Buddhism after it was introduced to China. At this time, he established a new format called the ten-subjects (十科). In 645, Daoxuan (道宣) used these ten-subjects as the basic framework to compile Xu-Gaosengzhuan (續高僧傳). However, by modifying and supplementing some parts of the ten-subjects, he standardized the ten-subjects into a format suitable for historiography. After the Xu-Gaosengzhuan, several versions of Biographies of the Eminent Monks were compiled in a format that further modified the ten-subjects. Fazang (法藏) wrote Huayanjing zhuanji (華嚴經傳記, 690?) which consisted of the ten-subjects, but the names and meanings of the subjects changed significantly to emphasize the Avatamsaka philosophy. Subsequently, while compiling Hongzan fahuazhuan (弘贊法華傳, 706?), Huixiang (惠詳) compiled a newly modified list of eight-subjects based on the ten-subjects of Gaosengzhuan and Xu-Gaosengzhuan. Sengxiang (僧詳) compiled Fahua xhuanji (法華傳記, 750?) in the format of twelve-subjects which added two new subjects to the ten-subjects of the Huayanjing zhuanji. These two formats focused on faith rather than philosophy. Even in the Chan (Zen) schools, a series of Biographies of the Eminent Monks was compiled from the beginning of the 8th century. Chuan fabaoji (傳法寶紀, 713?), Lengqui shiziji (楞伽師資記, 713?), Lidai fabaoji (歷代法寶記, 774), and Baolin zhuan (寶林傳, 801) are all examples of such compilations. However, the format of these four Biographies of the Eminent Monks was completely different from prior versions. Without setting any subjects, the authors established and described a dharma lineage transmitted continually from master to disciple. This is because Chan Buddhism does not rely on Buddhist texts but focuses on monks achieving realization through other means. At first, only the Chinese patriarchs were listed, but starting with Baolin zhuan, 27 patriarchs including Buddha and Kasyapa were included in the dharma lineage and presented as history. This fictional lineage was based on the need to secure sectarian superiority and legitimacy as Chan Buddhism flourished.

Immune Cells Are Differentially Affected by SARS-CoV-2 Viral Loads in K18-hACE2 Mice

  • Jung Ah Kim;Sung-Hee Kim;Jeong Jin Kim;Hyuna Noh;Su-bin Lee;Haengdueng Jeong;Jiseon Kim;Donghun Jeon;Jung Seon Seo;Dain On;Suhyeon Yoon;Sang Gyu Lee;Youn Woo Lee;Hui Jeong Jang;In Ho Park;Jooyeon Oh;Sang-Hyuk Seok;Yu Jin Lee;Seung-Min Hong;Se-Hee An;Joon-Yong Bae;Jung-ah Choi;Seo Yeon Kim;Young Been Kim;Ji-Yeon Hwang;Hyo-Jung Lee;Hong Bin Kim;Dae Gwin Jeong;Daesub Song;Manki Song;Man-Seong Park;Kang-Seuk Choi;Jun Won Park;Jun-Won Yun;Jeon-Soo Shin;Ho-Young Lee;Ho-Keun Kwon;Jun-Young Seo;Ki Taek Nam;Heon Yung Gee;Je Kyung Seong
    • IMMUNE NETWORK
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    • v.24 no.2
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    • pp.7.1-7.19
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    • 2024
  • Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019. In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virus-infected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105 PFU; however, 1×12 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.

Manufacturing Techniques of Bronze Seated Bodhisattva Statue of Goseongsa Temple in Gangjin (강진 고성사 청동보살좌상의 제작기술 연구)

  • LEE Seungchan;BAE Gowoon;CHUNG Kwangyong
    • Korean Journal of Heritage: History & Science
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    • v.57 no.1
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    • pp.146-159
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    • 2024
  • In this study, a study on the production technology of the Buddha statue and the production of raw material origin was conducted through scientific analysis on the Bronze seated Bodhisattva Statue of Goseongsa Temple, a treasure. As a result of microstructure analysis through a metal microscope, it was confirmed that the microstructure of the Bronze seated Bodhisattva Statue of Goseongsa Temple was a process-type dendritic structure, and the casting structure of bronze was well represented, so it was manufactured through casting. Subsequently, as a result of analyzing the alloy composition ratio through SEM-EDS, it was identified as a ternary alloy with 81.26 wt% of copper (Cu) and 16.42 wt% of tin (Sn) and 1.72 wt% of lead (Pb). The results of the analysis of lead isotope ratios using a thermal ionization mass spectrometer (TIMS) were substituted into the distribution of lead isotope ratios on the Korean Peninsula, it was shown in corresponding to Jeolla-do and Chungcheong-do regions and North and South Gyeongsang Province. This suggests that the raw materials used in their production were likely sourced from the mines around Goseong Temple in Gangjin. Despite the fact that the statue is a medium and large Buddha with a total height of 51 centimeters, 1.72 wt% of lead (Pb) was found as a result of alloy composition ratio analysis, which showed a similar composition to the lead content ratio of small bronze and gilt-bronze Buddha statues. Therefore, we compared and analyzed the results of the analysis of the composition ratio of the alloys of bronze and gilt bronze statues, which has been scientifically analyzed with a compositional age similar to that of the Bronze seated Bodhisattva Statue of Goseongsa Temple. Comparison results, Various factors, such as the size of the Buddha statue as well as its stylistic characteristics and the age of composition, may exist in determining the alloy composition ratio of the bronze and gilt bronze Buddha statues, and it was confirmed that the alloy composition ratio or casting technology was properly adjusted when the Buddha statue was created. In other words, it is judged that a more comprehensive system of Buddha statue production technology should be investigated by conducting archaeological and art history studies on stylistic characteristics and age of composition, as well as scientific analysis results such as observation of internal structure, microstructure observation, and analysis of alloy composition ratio using radiation transmission irradiation.

Contactless Data Society and Reterritorialization of the Archive (비접촉 데이터 사회와 아카이브 재영토화)

  • Jo, Min-ji
    • The Korean Journal of Archival Studies
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    • no.79
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    • pp.5-32
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    • 2024
  • The Korean government ranked 3rd among 193 UN member countries in the UN's 2022 e-Government Development Index. Korea, which has consistently been evaluated as a top country, can clearly be said to be a leading country in the world of e-government. The lubricant of e-government is data. Data itself is neither information nor a record, but it is a source of information and records and a resource of knowledge. Since administrative actions through electronic systems have become widespread, the production and technology of data-based records have naturally expanded and evolved. Technology may seem value-neutral, but in fact, technology itself reflects a specific worldview. The digital order of new technologies, armed with hyper-connectivity and super-intelligence, not only has a profound influence on traditional power structures, but also has an a similar influence on existing information and knowledge transmission media. Moreover, new technologies and media, including data-based generative artificial intelligence, are by far the hot topic. It can be seen that the all-round growth and spread of digital technology has led to the augmentation of human capabilities and the outsourcing of thinking. This also involves a variety of problems, ranging from deep fakes and other fake images, auto profiling, AI lies hallucination that creates them as if they were real, and copyright infringement of machine learning data. Moreover, radical connectivity capabilities enable the instantaneous sharing of vast amounts of data and rely on the technological unconscious to generate actions without awareness. Another irony of the digital world and online network, which is based on immaterial distribution and logical existence, is that access and contact can only be made through physical tools. Digital information is a logical object, but digital resources cannot be read or utilized without some type of device to relay it. In that respect, machines in today's technological society have gone beyond the level of simple assistance, and there are points at which it is difficult to say that the entry of machines into human society is a natural change pattern due to advanced technological development. This is because perspectives on machines will change over time. Important is the social and cultural implications of changes in the way records are produced as a result of communication and actions through machines. Even in the archive field, what problems will a data-based archive society face due to technological changes toward a hyper-intelligence and hyper-connected society, and who will prove the continuous activity of records and data and what will be the main drivers of media change? It is time to research whether this will happen. This study began with the need to recognize that archives are not only records that are the result of actions, but also data as strategic assets. Through this, author considered how to expand traditional boundaries and achieves reterritorialization in a data-driven society.