• Title/Summary/Keyword: 초기 중심

Search Result 2,202, Processing Time 0.03 seconds

Innovative Transient Thermal Gradient Control to Prevent Early Aged Cracking of Massive Concrete (매스콘크리트의 열경사 조절에 의한 수화열과 온도균열의 방지)

  • Kim, Seong-Soo;Cho, Tae-Jun;Lee, Jeong-Bae
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.12 no.6
    • /
    • pp.164-172
    • /
    • 2008
  • The heat of hydration for early aged mass concrete induces high temperature with the hydration. Control of the temperature difference across a section is an effective strategy to minimize the hydration heat induced cracks for the structures where internal restraint is dominant. The current prevention methods for hydration cracking show some limitations for the control of thermal gradients, and these limitations could make micro and macro cracks in surface and core of concrete. Especially cooling methods can decrease the increasing hydration temperature, but it can not prevent the problem while decreasing temperature. Consequently heating pipes are added simultaneously with the cooling pipes in order to control the temperature gradients between core and surface of the concrete, followed by the finite element analysis (FEA). Based on the FEA, the proposed method using cooling pipe and heating pipes together has been found to be an effective alternative in thermal gradient control, in terms of controlling temperature induced cracks significantly.

Development of Smart Port Technology Introduction Priorities Using AHP Analysis - Focusing on the automation pier of Gwangyang Port - (AHP분석을 활용한 스마트항만 기술 도입 우선순위 도출 - 광양항 자동화부두를 중심으로 -)

  • Han, Seung-Hoon;Ahn, Seung-Hyun;Lee, Hye-Ryeong
    • Journal of Korea Port Economic Association
    • /
    • v.40 no.2
    • /
    • pp.79-90
    • /
    • 2024
  • This study focuses on prioritizing the technology needed for the Gwangyang Port automated terminal. While the world's leading ports are moving forward with the implementation of full unmanned automation and digital smartisation, South Korea is still in the early stages of this process. In order to enhance domestic smart port capabilities and technological competitiveness, the government is promoting the construction of a fully automated terminal at Gwangyang Port. This terminal will test various advanced technologies in the domestic port sector and build infrastructure capable of responding to increasingly sophisticated technologies. The study defines the concept of a smart port for Gwangyang Port and derives an advanced technology pool from domestic and international research. Expert survey and AHP analysis were used to calculate the weight of each technology attribute based on characteristics and urgency. The integration of these weights and importance scores determined the priority of technology adoption. The results showed that automation and optimisation technologies had the highest priority, while environmental and energy-related technologies ranked lower.

An Analysis of Domestic and Foreign Research Trends Related to Libraries and Artificial Intelligence (도서관과 인공지능 관련 국내외 연구 동향 분석)

  • Hyung-Tae Kim;Seung-Jin Kwak
    • Journal of the Korean Society for Library and Information Science
    • /
    • v.58 no.3
    • /
    • pp.309-332
    • /
    • 2024
  • This study analyzed domestic and international research trends on libraries and artificial intelligence(AI). Among the papers published from 1995 to 2024, papers with keywords for libraries and artificial intelligence were targeted. A total of 13 papers registered in the KCI in Korea and 305 papers registered in the Web of Science(WOS) in foreign countries were collected. Targeting the abstracts and keywords of the collected papers, the frequency of keyword appearance by period was identified and network analysis was performed. As a result of the analysis, it was found that research related to artificial intelligence in libraries is increasing rapidly and is diversifying and subdividing. In addition, it was confirmed that if the service and user-related research was conducted in the early stages, it was gradually changing to the target technology, data, and data-related research.

A Comparative Study on the Perception of a Leading Smart Device Brand in Korea and China: Focusing on Text Analysis

  • Eun-Ji Lee;Jae-Young Moon
    • Journal of the Korea Society of Computer and Information
    • /
    • v.29 no.9
    • /
    • pp.225-236
    • /
    • 2024
  • This study focuses on Xiaomi, which has gained attention amid the Fourth Industrial Revolution. Using Textom, customer perceptions of Xiaomi were collected over approximately 10 years and analyzed. Data from 2015 to 2023 were used to compare customer perceptions in South Korea and China. The analysis revealed that before 2016, both countries focused on Xiaomi as a company and its basic products. However, after 2016, perceptions shifted to include keywords related to expansion products. Additionally, perceptions of Xiaomi were positive in both countries, with South Korea showing an increasing positivity, while China maintained positive views. This suggests that entry barriers for Xiaomi in the domestic market have decreased significantly. Future research should involve big data analysis and comparative studies with other countries for more objective insights.

Research Perspectives and Research Issues on the Origins of Korean Technology Culture: Focusing on Amateur Radio

  • Sangkil Yoon
    • Journal of the Korea Society of Computer and Information
    • /
    • v.29 no.10
    • /
    • pp.197-205
    • /
    • 2024
  • Starting with the problem that the origin of Korean technology culture lies in the technology culture of amateur radio lovers in the 1950s and 1960s, the purpose of this study is to explore the research perspective and research issues necessary for the historical study of Korean amateur radio, which has remained a blind spot. More specifically, the main contents of the 'social constructivism of technology' theory, which is a perspective that is mainly interested in the early history phase and a theoretical resource that views the relationship between technology and culture, were examined, and technology culture of amateur radio lovers was examined. And based on this, major research issues were derived. The main research issues derived are to determine the historical composition of amateur radio in the 1950s and 1960s, to explain the Cold War transformation of Korean amateur radio (technology) culture, and to examine the relationship between radio electronics market and amateur radio hobby market growth.

A Study on the Status and Roles of the North Korean Strategic Forces (북한 전략군의 위상과 역할에 관한 연구)

  • 장철운
    • Korea and World Politics
    • /
    • v.33 no.4
    • /
    • pp.129-158
    • /
    • 2017
  • The names of North Korean nuclear and missile dedicated operations units have changed to artillery corps, missile guidance agency, strategic rocket forces, and strategic forces. The North Korean strategic forces is an independent military that has the status of the 4th army, which is distinguished from conventional forces. Unlike other units under the command of the chief of general staff, the strategic forces receives direct orders from the supreme commander. The strategic forces plays an important role in economic and nuclear armed constructions. However, since it is in the early stage of building nuclear forces, it does not play a role properly. The strategic forces is expected to give flexibility and diversity to North Korean conventional forces-based military strategy. If the strategic forces is not involved in the operation of the SLBMs, conflicts may arise over the right to operate nuclear and missile in North Korea.

A photoelastic study on the initial stress distribution of the upper anterior teeth retraction using combination loop archwire and sliding mechanics (Combination loon archwire와 활주역학을 이용한 상악전치의 후방 견인시 나타나는 초기 응력 분포에 관한 광탄성학적 연구)

  • Yim, Kang-Soon;Lee, Jin-Woo;Cha, Kyung-Suk
    • The korean journal of orthodontics
    • /
    • v.34 no.4 s.105
    • /
    • pp.303-312
    • /
    • 2004
  • An unfavorable tipping movement can occur during the retraction of anterior teeth because orthodontic force is loaded by brackets positioned far from the center of resistance. To avoid this unfavorable movement, a compensating curved wire or lingual root torque wire is used. The purpose of this study is to investigate, using photoelastic material, the distribution of initial stress associated with the retraction of the incisors according to the degree of the compensating curve, to model changes associated with tooth ud alveolar bone structure. The following results were obtained by analysis of the polarizing plate of the effects of initial stress resulting from retraction of the anterior teeth: 1. When the incisors were retracted using combination archwire or sliding mechanics, the maximal polarizing pattern of the apical area decreased as the degree of the compensating owe increased from 0 to 15 to 30. 2. When the incisors were retracted by the combination archwire or sliding mechanics, the maximal polarizing pattern of the canine and premolar area increased as the degree of the compensating curve increased from 0to 15to 30. 3. A lower degree of polarizing patterns were associated with the combination archwire technique than the sliding mechanics technique at a given force. The above results indicate that there is no significant difference between the combination loop archwire technique and sliding mechanics, for the retraction of maxillary anterior teeth with decreased lingual tipping tendency by a compensating curve on the arch wire. However, the use of sliding mechanics is more effective for the prevention of lingual inclination of the anterior teeth, because the hook used in sliding mechanics is closer to the center of resistance of the maxillary anterior teeth.

Shallow subsurface structure of the Vulcano-Lipari volcanic complex, Italy, constrained by helicopter-borne aeromagnetic surveys (고해상도 항공자력탐사를 이용한 Italia Vulcano-Lipari 화산 복합체의 천부 지하 구조)

  • Okuma, Shigeo;Nakatsuka, Tadashi;Komazawa, Masao;Sugihara, Mitsuhiko;Nakano, Shun;Furukawa, Ryuta;Supper, Robert
    • Geophysics and Geophysical Exploration
    • /
    • v.9 no.1
    • /
    • pp.129-138
    • /
    • 2006
  • Helicopter-borne aeromagnetic surveys at two different times separated by three years were conducted to better understand the shallow subsurface structure of the Vulcano and Lipari volcanic complex, Aeolian Islands, southern Italy, and also to monitor the volcanic activity of the area. As there was no meaningful difference between the two magnetic datasets to imply an apparent change of the volcanic activity, the datasets were merged to produce an aeromagnetic map with wider coverage than was given by a single dataset. Apparent magnetisation intensity mapping was applied to terrain-corrected magnetic anomalies, and showed local magnetisation highs in and around Fossa Cone, suggesting heterogeneity of the cone. Magnetic modelling was conducted for three of those magnetisation highs. Each model implied the presence of concealed volcanic products overlain by pyroclastic rocks from the Fossa crater. The model for the Fossa crater area suggests a buried trachytic lava flow on the southern edge of the present crater. The magnetic model at Forgia Vecchia suggests that phreatic cones can be interpreted as resulting from a concealed eruptive centre, with thick latitic lavas that fill up Fossa Caldera. However, the distribution of lavas seems to be limited to a smaller area than was expected from drilling results. This can be explained partly by alteration of the lavas by intense hydrothermal activity, as seen at geothermal areas close to Porto Levante. The magnetic model at the north-eastern Fossa Cone implies that thick lavas accumulated as another eruption centre in the early stage of the activity of Fossa. Recent geoelectric surveys showed high-resistivity zones in the areas of the last two magnetic models.

ATTACHMENT AND PSYCHOPATHOLOGY (애착과 정신병리)

  • Choi, Jee-Eun;Ahn, Dong-Hyun
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
    • /
    • v.15 no.1
    • /
    • pp.40-60
    • /
    • 2004
  • Introduction:Research on attachment in view point of the developmental perspective which began in the 1940s progressed during several decades. Many investigators focused mother-child separation in early attachment studies, and moved to the relationship with childhood psychopathology. Recently attachment theory and research are moving forward along the intergenerational transmission of attachment patterns, and adolescents and adult mental disorders in the developmental perspectives. Methods:We surveyed the research papers through Medline search, attachment-related monographs, and review or original papers published in Korean journal. Results:Developmental attachment researches have demonstrated convincingly that insecure attachment in infancy is associated with attachment disorder; several childhood psychopatholgy, such as institutional care and adoption, aggression and behavioral problems, childhood anxiety disorders and depressive disorders, gender identity disorder and feeding disorder, and child abuse and maltreatment; peer relationship and social competency, and parental behaviors. Recently the methodological advances including the Adult Attachment Interview that systematically assesses the adults' recollections of the earlier parent-child relationship they experienced could move beyond attachment researcher's initial concern with infancy to consider attachment processes throughout the life span. We could find that the quality of attachment was associated with several mental disorders in adolescents and adults significantly. Conclusion:Attachment theory would have focused on more specific parent-child relationship than general parental behavior. Recent attachment theory underscores its evolutionary origins to promote development of infant and contribute to human survival in psychobiological bases. Advances in attachment research could unite interests in evolutional biology and developmental psychology in understanding early parent-child relationship, and apply to clinical issues concerning mental health throughout the life span.

  • PDF

A Study on the Shinmoongo System: Issues of the Origin and Changes of Function and Institution (신문고 제도에 대한 몇 가지 쟁점: 기원과 운영, 기능.제도의 변천을 중심으로)

  • Kim, Young-Ju
    • Korean journal of communication and information
    • /
    • v.39
    • /
    • pp.250-283
    • /
    • 2007
  • The Shinmoongo (Shinmoon-drum) system is known as the last means of petition, appeal, and, denunciation during the Chosun dynasty. The purpose of this study is first to examine the system's origin and changes of its function and operation. The study further looks at several issues around the striking gong system, an alternative appealing method, and its background and transition. Introduced by King Taejong, the Shinmoongo was a kind of the press (or communication) system which was intended to deliver various cases of personal appeal, social petition, national denunciation, etc. Since the 2nd year of King Sejong, the system had been changed into the legal system which mainly to settle personal mortifying problem. Originally, the system was institutionalized for the common people who were hard to appeal their mortifying affairs to the supervisory administration. This reporting system to a superior was utilized as an institutional device to remedy abuses from 'complaint to the King near his sedan chair' and 'direct complaint out of order' during the early disordered years of Chosun dynasty. The system was often abused for the devices of private interest by illustrious officials. Meanwhile, it carried out a role of checking power abuses of provincial governors and magistrates. There were many obstacles for the common people and lowly people to turn to the means. The drum was located at the palace of capitol, less accessible for most people at the time. The petition had to be processed through several steps in written forms. The punishment on a false drummer was heavy. It inhibited any appeal concerning the superior under the rigorous caste system. The Shinmoongo system is regarded as a legitimate press system. Also, it is taken as informal or semi-official press system such as 'document to send around', 'document for agitation', 'joint petition', 'striking gong to complain', 'complaint to the King near his sedan chair', 'scream to complain', etc. Connecting together, the tools resulted in the increase of regal power and decrease of divine authority.

  • PDF