• Title/Summary/Keyword: breaking point

Search Result 175, Processing Time 0.023 seconds

A Study of the Characteristics on the Vacuum Interrupter with Axial Magnetic Field Type using 3 Dimension Finite Element Analysis (3차원 유한요소해석을 이용한 종자게형 진공 인터럽터의 특성고찰)

  • 하덕용;강형부
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.15 no.5
    • /
    • pp.460-467
    • /
    • 2002
  • This paper deals with the distribution characteristics of the current density and axial magnetic flux density on the vacuum interrupter with axial magnetic field type using 3 dimension finite element analysis. An axial magnetic field parallel to the current flow in the arc column can improve the current breaking capacity of vacuum interrupter by affecting the arc mode. The axial magnetic flux density on the contact electrode surface is analyzed by inputting external current as a function of the transient time for sine half wave. And it also is analyzed within the gap distance of the contact electrode. The peak value of current but is decreased with the descending current on the contact electrode surface and within the gap distance of the contact electrode. The residual magnetic field is generated on the contact electrode surface and within the gap distance in the instant of zero current, which is due to the influence of eddy currents. The phase shift due to eddy currents, defined as time difference between the maximum value of current and axial magnetic field, is about 1ms in the center point of gap distance.

Capability Brown and His Landscape Gardening Style-with reference to the character in design and aesthetics- (영국 풍경식 정원가 의 스타일에 관한 연구 - 설계 특성과 미적 평가를 중심으로 -)

  • 방경란;최기수
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.26 no.3
    • /
    • pp.267-277
    • /
    • 1998
  • The background of this study is to provide meaning of landscape history and to find out landscape origines which were strongly concerned with the nature through breaking out the form of conventional adapting elements from an exterior. And the purpose of this study is to review Brown's philosophy as picturesque landscape architectur and to provide useful Brown's characteristics to contemporary landscape by epitomizing his design elements. Brown estiablished a foundation of the English landscape garden of the eighteenth century. And the concept, the beauty of nature, is considered as a beginning point of modernism study. The study of the Brownian style as profoundity theme is conversion view to the development of the history of garden. These days, the restoration of the Brownian style at the public or garden design in England is based on the nature recourse of the original character of human. And also his style can be understood to seek the progressive transformation as to perfectly known the possibility of the place, to get clues to the solutions, and to be able to iprove the quality of environment. Therefore, Brown's efforts for seeding the essence of landscape architecture escaping from Englands old-fashioned landscape design skills might be considered in high worth.

  • PDF

Cache Reliability Enhancing Method for Recursive DNS (Recursive DNS의 캐쉬 정보 신뢰성 향상 기법)

  • Ju, Yong-Wan;Lee, Eung-Jae;Nam, Kwang-Woo
    • The KIPS Transactions:PartC
    • /
    • v.15C no.4
    • /
    • pp.227-238
    • /
    • 2008
  • As the internet users rise up rapidly, DNS information forgery can cause severe socio-economic damages. However, most studies on DNS information security reached the breaking point in applying to actual circumstances because of the limit of existing DNS system version, the increasement of management burden and etc. The paper proposes the real-time method for detecting cache poisoning of DNS system independent of analysing the DNS forgery types in the current DNS service environment. It also proposes the method of enhancing the reliability for the cache information of Recursive DNS system by post-verifying the cache information of the DNS system.

HACCP System Application on Chicken Entrees Served by Lunch Program of Elementary Schools (초등학교 급식소에서 제공되는 닭고기 주요리의 급식품질 확보를 위한 HACCP 시스템 적용연구)

  • 조경동;이복희
    • Korean journal of food and cookery science
    • /
    • v.20 no.1
    • /
    • pp.63-75
    • /
    • 2004
  • This study was conducted to establish the hygiene standards for chicken entrees (deep-fried breast chicken, chicken and potato in red pepper paste and smothered chicken) served with in 3 different elementary school lunch programs during 2002. The study evaluated the layout characteristics of the food facilities, and determined the physical and microbiological hazards for the production of chicken entrees based on the HACCP(Hazard Analysis Critical Control Point) system. The kitchen layouts needed to be remodeled for the separation of soiled and clean work areas. The pH values for all items were over 6.0, which require careful attention. The microbial assessments of 3 chicken items revealed that the TPC, coliforms and Staphylococcus aureus were within normal ranges, but Salmonella was found at several stages in the production of all products, with the exception of smothered chicken. The bacterial counts of the kitchen utensils and cooks' hands exceeded acceptable limits, and workers' sanitary practices were poor in terms of sanitary handling and holding of foods and utensils. The CCPs determined related to the steps of receiving, cooking and breaking of egg shells. From our findings, it is recommended that chicken entrees should be prepared and served very carefully, as salmonella was detected at several stages during meal production, and the aim of the HACCP system is to secure against food-borne illnesses due to reckless school food service operations.

A Study onThe Success factors of Mobile Games (모바일게임의 성공요인에 대한 연구)

  • Kim, Do-Goan;Nam, Su-Tae;Jin, Chan-Yong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2014.05a
    • /
    • pp.189-191
    • /
    • 2014
  • Todays, with the spread of Mobile devices, game industry has experienced the change of supply chain structure and paradigm. Breaking the traditional supply chain of game industry, mobile games of App. markets provide alternatives or threats against traditional game industry. With the mobility as a strongpoint, mobile games have their own characteristics such as convenience, easy of use and simplicity comparing PC games or other games. In this point, this study is to find success factors of mobiles games through the analysis on the highly ranked favorite games according to the types of mobile games.

  • PDF

The characteristics of modern Chinese menswear design - Designer brands that have entered the world stage - (중국 현대 남성복 디자인 특성 연구 - 세계무대에 진출한 중국 디자이너 브랜드를 중심으로 -)

  • Pan, Wei;Lee, Soon Jae
    • The Research Journal of the Costume Culture
    • /
    • v.29 no.2
    • /
    • pp.222-239
    • /
    • 2021
  • In this study, six mainland Chinese designer brands-Xander Zhou, Sankuanz, Sean Suen, Feng Chen Wang, Pronounce, and Angel Chen-were selected that had their works presented at both Chinese and global fashion shows between 2016 and 2021. By analyzing the design characteristics of each brand, it is possible to understand the style characteristics and trends of Chinese menswear designs. A case study approach was adopted utilizing literature data, whereby 1663 photos were collected from the fashion information website POP (www.pop-fashion.com). Changes in Chinese men's image and the menswear market were identified. The design characteristics of modern Chinese menswear are as follows. First, the results from analyzing the target brands show that each brand has a distinct personality. Compared with the traditional or formal style, urban casual and sports styles (based on street style) account for a larger proportion. Second, the boundaries between different styles are becoming ambiguous, and contrasting styles are harmoniously expressed by breaking down boundaries through changes and combinations of colors, materials, and details. Third, after examining the overall trend, 2018 was a watershed point, after which the design trend has changed from either conservative or exaggerated to a practical and everyday style, demonstrating a genderless trend.

Dynamics of moored arctic spar interacting with drifting level ice using discrete element method

  • Jang, HaKun;Kim, MooHyun
    • Ocean Systems Engineering
    • /
    • v.11 no.4
    • /
    • pp.313-330
    • /
    • 2021
  • In this study, the dynamic interaction between an Arctic Spar and drifting level ice is examined in time domain using the newly developed ice-hull-mooring coupled dynamics program. The in-house program, CHARM3D, which is the hull-riser-mooring coupled dynamic simulator is extended by coupling with the open-source discrete element method (DEM) simulator, LIGGGHTS. In the LIGGGHTS module, the parallel-bonding method is implemented to model the level ice using an assembly of multiple bonded spherical particles. As a case study, a spread-moored Artic Spar platform, whose hull surface near waterline is the inverted conical shape, is chosen. To determine the breaking-related DEM parameter (the critical bonding strength), the four-point numerical bending test is used. A series of numerical simulations is systematically performed under the various ice conditions including ice drift velocity, flexural strength, and thickness. Then, the effects of these parameters on the ice force, platform motions, and mooring tensions are discussed. The simulations reveal various features of dynamic interactions between the drifting ice and moored platform for various ice conditions including the novel synchronous resonance at low ice speed. The newly developed simulator is promising and can repeatedly be used for the future design and analysis including ice-floater-mooring coupled dynamics.

The effects of royal jelly protein on bone mineral density and strength in ovariectomized female rats

  • Hattori, Satoshi;Omi, Naomi
    • Korean Journal of Exercise Nutrition
    • /
    • v.25 no.2
    • /
    • pp.33-37
    • /
    • 2021
  • [Purpose] Sex hormones deficiency leads to dramatically bone loss in particular postmenopausal women. Royal jelly has anti-osteoporosis effect due to maintain bone volume in that condition. We hypothesized that royal jelly protein (RJP, a latent residue after extracting royal jelly) also prevents bone deficient in ovariectomized (OVX) female rats, the animal model of postmenopausal women. [Methods] Female Sprague-Dawley rats (n = 30, 6 weeks age old) were sham operated (Sham; sham operated group, n = 7), OVX control group (OC, n = 7), OVX with low RJP intake group (ORL, n = 8), and OVX with high RJP intake group (ORH, n = 8) during 8 weeks experimental periods. In the end point of this experiment, the bone samples (lumbar spine, tibia, and femur) were surgically removed under anesthesia. These bone samples were evaluated bone mineral density (BMD) and bone strength. [Results] BMD of lumbar spine in RJP intake groups (ORL, ORH) were higher than that in OC group (p < 0.05 and p < 0.01) in RJP intake volume dependent manner. BMD of tibial proximal metaphysis and diaphysis in RJP intake groups were also higher than these in OC group (p < 0.01 and p < 0.01 / p < 0.05 and p < 0.001). In addition, breaking force of femur in RJP intake groups were significantly increase compared with that in OC group (p < 0.001 respectively). [Conclusion] These findings indicate that RJP contribute to prevent sex hormone related bone abnormality.

A Study on Social Perceptions of Public Libraries Utilizing the sentiment analysis

  • Noh, Younghee;Kim, Dongseok
    • International Journal of Knowledge Content Development & Technology
    • /
    • v.12 no.4
    • /
    • pp.41-65
    • /
    • 2022
  • This study would understand the overall perception of our society about public libraries, analyzing the texts related to public libraries, utilizing the semantic connection network & sentiment analysis. For this purpose, this study collected data from the last five years with keywords, 'Library' and 'Lifelong Learning Center' from January 1, 2016 through November 30, 2020 through the blogs and cafés of major domestic portal sites. With the collected data, text mining, centrality of keywords, network structure, structural equipotentiality, and sensitivity analyses were conducted. As a result of the analysis, First, 'reading' and 'book' were identified as representative keywords that form the social perception of public libraries. Second, it turned out that there were keywords related to the use of the library and the untact service due to the recent spread of COVID-19. Third, in seeking a plan for the development of public libraries through the keywords drawn to have positive meanings, it is necessary to create continuous services that can form a new image of the library, breaking away from the existing fixed role and image of the library and increase the convenience of use. Fourth, facilities and facilities for library services were recognized from a neutral point of view. Fifth, the spread of infectious diseases, social distancing, and temporary closure and closure of libraries are negatively related to public libraries, and awareness of librarians has been identified as negative keywords.

Recent Trends of Abnormal Sea Surface Temperature Occurrence Analyzed from Buoy and Satellite Data in Waters around Korean Peninsula

  • Choi, Won-Jun;Yang, Chan-Su
    • Korean Journal of Remote Sensing
    • /
    • v.38 no.4
    • /
    • pp.355-364
    • /
    • 2022
  • In this study a tendency of abnormal sea surface temperature (SST) occurrence in the seas around South Korea is analyzed from daily SST data from satellite and 14 buoys from August 2020 to July 2021. As thresholds 28℃ and 4℃ are used to determine marine heatwaves(MHWs) and abnormal low water temperature (ALWT), respectively, because those values are adopted by the National Institute of Fisheries Science for the breaking news of abnormal temperature. In order to calculate frequency of abnormal SST occurrence spatially by using satellite SST, research area was divided into six areas of coast and three open seas. ALWT dominantly appeared over a wide area (7,745 km2) in Gyeonggi Bay for total 94 days and it was also confirmed from buoy temperature showing an occurrence number of 47 days. MHWs tended to be high in frequency in the coastal areas of Chungcheongdo and Jeollabukdo and the south coastal areas while in case of buoy temperature Jupo was the place of high frequency (32 days). This difference was supposed to be due to the low accuracy of satellite SST at the coasts. MHWs are also dominant in offshore waters around Korean Peninsula. Although detecting abnormal SST by using satellite SST has advantage of understanding occurrence from a spatial point of view, we also need to perform detection using buoys to increase detection accuracy along the coast.