• Title/Summary/Keyword: first order line

Search Result 786, Processing Time 0.024 seconds

Development of a Solar Concentrator having the Reflecting Surface with the 2m Class Diameter (직경 2m급 반사면을 가지는 태양열 집광 장치 개발)

  • Cha, Jung-Won;Lee, Dong-Hee
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.13 no.4
    • /
    • pp.75-81
    • /
    • 2008
  • Purpose: To develop a solar concentrator having the reflecting surface with the 2m class diameter. Methods: In order to make the reflecting surface for the solar concentrator, the shape of the reflecting surface sector is required. So, first, we induced the formula that can produce this shape. After that, using Delphi 6.0 language, we developed a program which uses this formula and produces the shape and the numerical data of the reflecting surface sector with the input variables such as the external diameter of the reflecting mirror, the reflecting mirror's radius of curvature at the paraxial range, the number of reflecting mirror sector, the size of the center hole of the reflecting mirror, and the interval of the output data. Results: This program, which was developed to produce the shape and the numerical data of the reflecting surface sector, enables us to see the shape of sector on the monitor and to save the numerical data files for the shape of sector. As a result, the user of this program can easily access the numerical data of the reflecting surface sector. Conclusions: Developing the program which produce the reflecting surface sector used to make the reflecting surface of the solar concentrator, we could succeed in making the prototype products by applying it to the development of the real solar concentrator with the diameter of the 2m class.

  • PDF

Microbial Changes of Salted and Fermented Shrimp by High Hydrostatic Pressure Treatment (초고압처리에 의한 새우젓의 미생물변화)

  • Mok, Chul-Kyoon;Song, Ki-Tae;Lee, Sang-Ki;Park, Jong-Hyun;Woo, Gun-Jo;Lim, Sang-Bin
    • Korean Journal of Food Science and Technology
    • /
    • v.32 no.2
    • /
    • pp.349-355
    • /
    • 2000
  • This study was conducted to enhance the storage stability of fermented shrimp with different salt contents using a high hydrostatic pressure. The effects of the magnitude of pressure and treatment time on the microorganisms of the fermented shrimp were investigated. The highest microbial counts with respect to the salt levels were observed at 18% salt, showing $3.4{\times}10^5\;CFU/g$ for general bacteria, $6.4{\times}10^4\;CFU/g$ for halophilic bacteria, $4.2{\times}10^5\;CFU/g$ for yeast and $3.0{\times}10^4\;CFU/g$ for halophilic yeast. The degree of sterilization increased with the magnitude of pressure and treatment time, and the sterilization could be analyzed by the first order reaction kinetics. The sterilization rate constants $(k_p)$ of the halophilic bacteria was lower than that of general bacteria. The $log(k_p)$ increased linearly with pressure and the slope of the regression line of the halophilic bacteria was greater than that of general bacteria, indicating that the sterilization of the halophilic bacteria was more dependent on the pressure. High hydrostatic pressure treatment was an effective non-thermal sterilization method for the salted and fermented shrimp, and the optimum treatment condition was for 10 min at 6,500 atm.

  • PDF

Future Scenarios of Asian Universities in a view Point of Equality (평등의 관점에서 본 아시아 대학의 미래 시나리오)

  • Ryu, Cheong-San
    • Korean Journal of Comparative Education
    • /
    • v.24 no.5
    • /
    • pp.53-70
    • /
    • 2014
  • This study was performed in order to suggest the future model of Asian universities that could be used in the planning of the global competitive strategy. Futurologists forecasted the future of higher education using Harman Fan Scenario as like this. First, most current universities will be 'the satellite university' until 2015. Second, they also will replace 'the bookless university' until 2020. Third, they will be 'no calendar university' until 2025. And then they may be 'all have access university' until 2030. After 2030, futurologists prospected that almost universities based on off-line campus will be disappeared into the history. The analysis method of Harman fan scenario and applied scenarios were also used to "A study on the future scenario of Korean university". The predictive model and the alternative models were explored in a view point of students, enterprise, and government. Individuality with educational excellence are standardized for learner, profit and effectiveness are applied for enterpriser, and equality with welfare are adapted for national leader. Asian universities need to focus on bringing up the practical ability based on conscious and emotional education instead of knowledge based on memory. Also they need to enforce the specialized education that can create new jobs through convergence of interdisciplinary. Especially, Asian nations need to explore, to find the strengthen area of their universities compared with USA. And these area should be specialized. The convergency strategy between oriental medicine and informatics is a meaningful sample. Based on this point, a predicted with 3 alternative scenarios in a view point of equality were suggested for the future of Asian universities.

A REVIEW ON THE ODSCC OF STEAM GENERATOR TUBES IN KOREAN NPPS

  • Chung, Hansub;Kim, Hong-Deok;Oh, Seungjin;Boo, Myung Hwan;Na, Kyung-Hwan;Yun, Eunsup;Kang, Yong-Seok;Kim, Wang-Bae;Lee, Jae Gon;Kim, Dong-Jin;Kim, Hong Pyo
    • Nuclear Engineering and Technology
    • /
    • v.45 no.4
    • /
    • pp.513-522
    • /
    • 2013
  • The ODSCC detected in the TSP position of Ulchin 3&4 SGs are typical ODSCC of Alloy 600MA tubes. The causative chemical environment is formed by concentration of impurities inside the occluded region formed by the tube surface, egg crate strips, and sludge deposit there. Most cracks are detected at or near the line contacts between the tube surface and the egg crate strips. The region of dense crack population, as defined as between $4^{th}$ and $9^{th}$ TSPs, and near the center of hot leg hemisphere plane, coincided well with the region of preferential sludge deposition as defined by thermal hydraulics calculation using SGAP computer code. The cracks developed homogeneously in a wide range of SGs, so that the number of cracks detected each outage increased very rapidly since the first detection in the $8^{th}$ refueling outage. The root cause assessment focused on investigation of the difference in microstructure and manufacturing residual stress in order to reveal the cause of different susceptibilities to ODSCC among identical six units. The manufacturing residual stress as measured by XRD on OD surface and by split tube method indicated that the high residual stress of Alloy 600MA tube played a critical role in developing ODSCC. The level of residual stress showed substantial variations among the six units depending on details of straightening and OD grinding processes. Youngwang 3&4 tubes are less susceptible to ODSCC than U3 and U4 tubes because semi-continuous coarse chromium carbides are formed along the grain boundary of Y3&4 tubes, while there are finer less continuous chromium carbides in U3 and U4. The different carbide morphology is caused by the difference in cooling rate after mill anneal. There is a possibility that high chromium content in the Y3&4 tubes, still within the allowable range of Alloy 600, has made some contribution to the improved resistance to ODSCC. It is anticipated that ODSCC in Y5&6 SGs will be retarded more considerably than U3 SGs since the manufacturing residual stress in Y5&6 tubes is substantially lower than in U3 tubes, while the microstructure is similar with each other.

The Meaning of Space in Los bravos (『용감한 사람들 Los bravos』에 나타난 공간의 의미)

  • Kim, Son-Ung
    • Cross-Cultural Studies
    • /
    • v.46
    • /
    • pp.173-197
    • /
    • 2017
  • The present work aims to analyze the concept of space in $Jes{\acute{u}}s$ $Fern{\acute{a}}ndez$ Santos' work Los bravos. Throughout its pages, one can observe the multidimensional possibilities of space in literature. Throughout time, the concept of literary space has developed and it has been modified constantly in order to meet the needs required for the evolution of narratology. In the past, Aristotle stated that space is the place where characters and physical objects happen to exist. This remained almost unchanged until the Renaissance. In the $19^{th}$ century, space stopped being considered just a mere scene where the action takes place as it was given more importance by romantic authors in their works. Realism intensified the spaces as the interior of the house. In fact, the descriptions of space became more important. In this article, I focus on the various meanings of space in the novel Los bravos. First, I analyze the dichotomy between real and ideal spaces, and continue with the cathartic dimension of the fictional space. Then, I present and analyze the opposition between urban and rustic spaces in this novel, and, finally, I show the confrontation between the spaces of men and women. Through this analysis, we can observe that characters have a space where they feel more comfortable and how, occasionally, they leave their "usual space of action" to reach their "ideal place". Women want to stay in their kitchen to chat with each other, while men prefer to leave the house to visit a cafe with their colleagues. The door and the window divide the border of the worlds of men and women. However, that line is not only dividing the structure of the house, but it is also of a psychological house.

A Collecting and Record of Wide Area Cultural Resources : the Case of Asian Cotton Cultural Resources (광역 문화자원의 수집과 기록 : 아시아 목화문화자원을 중심으로)

  • Noh, Shi-Hun
    • The Korean Journal of Archival Studies
    • /
    • no.28
    • /
    • pp.123-153
    • /
    • 2011
  • In Asia, when cotton and cotton fabrics cultivated and produced in India of Southern Asia had spread to the whole Asia area by land and by sea, the Cotton Road and cotton fabric cultural area could be formed. In Korea, the traditional cotton (Gossypium arboreum) brought by Moon Ik-Jeom in 1363 was cultivated and then the Upland cotton (Gossypium hirsutum) brought via Japan could be produced from 1904. Especially, Gwangju/Jeonnam was the most active place in producing traditional cotton, and eventually became the center of cotton cultivation and fabric production after bringing in Upland cotton. In order to collect and record the cotton cultural resources in the broad area, the Cultural Resources Set, classified its component parts should be made first and then the collecting objects should be investigated. The collecting areas are selected based on the spreading paths and the regional significance of cotton. Since its difficulty of collecting the relevant resources from all of the places in Asia, it should be planned to share the resources through exchanges and cooperation among private, institution and organization. The relevant experts from the various fields should participate in the interdisciplinary researches which are necessary for collecting and recording of wide area cultural resources. Considering the collecting limitation of genuine relics, the digital archives should be established and then offered through a web site that everyone can use them freely by remote. It also needs to plan to display on and off-line for users to perceive the similarity, difference and interconnections of the resources with ease.

Effect of milling tool wear on the internal fit of PMMA implant interim prosthesis (밀링 공구의 마모가 PMMA 임플란트 임시보철물 변연 및 내면적합도에 미치는 영향)

  • Shin, Mi-sun
    • Journal of Technologic Dentistry
    • /
    • v.41 no.2
    • /
    • pp.63-69
    • /
    • 2019
  • Purpose: The purpose of this study is to evaluate the effect of CAD/CAM system milling tool wear on the marginal and internal fit of PMMA implant interim prosthesis three-dimensional manner. Methods: A total of 20 crowns were fabricated with CAD/CAM method. Their designs were unified to first molar of the left maxilla. The Customized abutments were prepared and scanned with on optical model scanner. Five crowns were milled by the newly replaced tool (1st milling), and 15 crowns were milled by 2nd, 3rd, 4th milling tool. The marginal and internal fit of 20 interim crowns were measured using the triple-scan protocol. Results: Statistically significant difference was found between the $1^{st}$ milling group ($51.8{\pm}14.6{\mu}m$) and the $3^{rd}$, $4^{th}$ milling group ($128.6{\pm}43.8{\mu}m$, $146.2{\pm}38.1{\mu}m$, respectively) at the distal margins. In the mesial margins, There was a statistically significant difference between the $1^{st}$ milling group ($63.6{\pm}25.9{\mu}m$) and the $3^{rd}$, $4^{th}$ milling group ($137.2{\pm}25.9{\mu}m$, $186.8{\pm}70.6{\mu}m$, respectively). In the distal line angle, significant difference was found between the $1^{st}$, $2^{nd}$, $3^{rd}$ milling groups and the $4^{th}$ milling group. In the mesial axial wall, significant difference was found between the $1^{st}$ milling group ($52.2{\pm}20.3{\mu}m$) and the $3^{rd}$, $4^{th}$ milling groups ($22.8{\pm}8.8{\mu}m$, $7.8{\pm}5.7{\mu}m$). Conclusion: As a result of the experiment, decrease of the marginal and internal fit was statistically significant as the number of machining cycles increased. In order to produce clinically excellent restorations, it is recommandable to consider the condition of the milling tool wear, when designing the restoration with CAD program.

A Study on Landscape Formation Techniques of Summer Palace as Royal Garden in China (이화원 황가원림의 경관연출기법 연구)

  • An, Seung-Hong;Yoon, Sung-Yung;Yeom, Sung-Jin;Yoon, Sang-Jun;Lee, Won-Ho
    • Journal of the Korean Institute of Traditional Landscape Architecture
    • /
    • v.36 no.4
    • /
    • pp.18-27
    • /
    • 2018
  • This study is a basic one analyzing the scenic characteristics that are created in Royal Garden in China while taking into consideration that Royal Garden in China is a fruit compiling all of the Chinese classical gardens. In case of Summer Palace in China, it adopted various kinds of landscape displaying techniques for fulfilling the desires of an Emperor who wanted to appreciate beautiful landscapes all the time. Accordingly, the scenic characteristics can be summarized as follows. First, Summer Garden creates various kinds of garden landscapes through various kinds of landscape creation techniques, such as, Borrowed Landscape, Central One, Background One, Symmetrical One, Axial One, Dividing One, Framed One, Window One and Complementing One, etc. Second, it was created in order for visitors to focus on appreciation of landscapes by allocating hard points while considering the symmetric structure, Structure of Long Corridor and Visual Physiology of a building on the basis of the South-North Pivotal Line. Third, it utilized the scenic spot transferring technique that introduces the landscapes of scenic spots in various regions of China to Summer Palace to be matched to the unique geological characteristics of Summer Garden. It was found that Summer Palace adopted the common landscaping techniques in Jiangnan Region of Ancient China since the landscape of Jichang Garden in Hangzhou and that of Shan Tang Jie in Suzhou are reproduced and transferred. It was found that 3 methods mentioned above have the effects that attract sightseers' eyes naturally and make their interests concentrated as well as reviving the feeling of space in a garden and creating abundant scenic beauty.

Study of instruction of recreation text according to the inheritance and acculturation of Korean classical literature text -Focused on 'On Dal Jeon' and Yoon seok san's 'On Dal's Dream'- (고전 텍스트의 계승과 변용에 따른 재창조 텍스트의 지도 방법 연구 -<온달전>과 윤석산의 <온달의 꿈>을 중심으로-)

  • Lee, Young-taek
    • Journal of Korean Classical Literature and Education
    • /
    • no.16
    • /
    • pp.147-179
    • /
    • 2008
  • Classical literature texts have been transmitted and recreated as subjective meanings in a wide variety of genres. Authors recreate another world with their own imagination and classical literature texts. This study has been conducted to analysis 'OnDal's Dream' which is an adaptation from 'OnDalJeon' in order to figure out the method of inheritance and the subject and message of the adaptation. The process of inheritance and acculturation appears in the literary world. Some adaptations stick to the genre of the original text, other adaptations change to various genres. There is the process of inheritance and acculturation in the aspect of structure of the adaptation 'OnDal's Dream'. lntertextuality can be found between 'OnDalJeon' and 'OnDal's Dream' in terms of the stages such as 'confrontation' between the ego and the world and 'overcoming' hardships. However, the recreation text has acculturation of the structure that shows the potential desire for elevation of social status at the end part of the work so I could possibly show that the adaptation has limitation because it was far from the dream of common people and laborers at that time. There are different structures and recognition systems between 'OnDal Jeon' and 'OnDal's Dream' because the formal is an epic tale the other is lyric tale. An epic tale has some partial symbols in its story line, while an lyric tale is a symbol as a whole. There is an exhibition of deep emotion which is subjectivized and symbolized against the world in the adaptation 'OnDal's Dream'. And the inheritance of unreality, which is acculturation to the world of dream, from the original text can be found in the adaptation. First of all, study between the original text and the recreation text should be conducted in terms of intertextuality. Secondly, an instruction on the inheritance which is based on intertextuality between the original text and the recreation text should be conducted. Thirdly, an instruction about the structure of a genre and differences of recognition systems according to inheritance or conversion of a genre. It will be helpful for children to stimulate to take an interest in classical literature texts and traditional arts, to learn more recreation texts, and to develop the practical ability to recreate works. Based on above study, an instruction which shows a spiritual value of literature should be conducted.

Identification of shear layer at river confluence using (RGB) aerial imagery (RGB 항공 영상을 이용한 하천 합류부 전단층 추출법)

  • Noh, Hyoseob;Park, Yong Sung
    • Journal of Korea Water Resources Association
    • /
    • v.54 no.8
    • /
    • pp.553-566
    • /
    • 2021
  • River confluence is often characterized by shear layer and the associated strong mixing. In natural rivers, the main channel and its tributary can be separated by the shear layer using contrasting colors. The shear layer can be easily observed using aerial images from satellite or unmanned aerial vehicles. This study proposes a low-cost identification method extracting geographic features of the shear layer using RGB aerial image. The method consists of three stages. At first, in order to identify the shear layer, it performs image segmentation using a Gaussian mixture model and extracts the water bodies of the main channel and tributary. Next, the self-organizing map simplifies the flow line of the water bodies into the 1-dimensional curve grid. After that, the curvilinear coordinate transformation is performed using the water body pixels and the curve grid. As a result, the shear layer identification method was successfully applied to the confluence between Nakdong River and Nam River to extract geometric shear layer features (confluence angle, upstream- and downstream- channel widths, shear layer length, maximum shear layer thickness).