• Title/Summary/Keyword: Nu-A

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Free Vibration Analysis of Orthotropic Triangular Plates with Simplified Series Function (단순급수함수를 이용한 직교이방성 복합재료 삼각판의 자유진동해석)

  • 이영신;정대근;나문수
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.5
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    • pp.849-863
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    • 1992
  • A very simple and computationally efficient numerical method is developed for the free vibration of isotropic and orthotropic composite triangular plates. A set of two-dimensional simple series functions is used as an admissible displacement functions in the Rayleigh-Ritz method to obtain the natural frequencies, nodal patterns and mode shapes for the plates. From the prescribed starting function satisfying only the geometric boundary conditions, the higher terms in the series functions are constructed with adding order of polynominal. Natural frequencies, nodal patterns and mode shapes are obtained for right triangular plates with three different support conditions. The obtained numerical results are presented, and the isotropic and some orthotropic cases are verified with other numerical methods in the liternature.

Development of BIM for a Maintenance System of Subway Infrastructures (지하철 구조물 유지관리 시스템을 위한 BIM 개발)

  • Shim, Chang-Su;Kim, Seong-Wook;Song, Hyun-Hye;Yun, Nu-Ri
    • Journal of KIBIM
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    • v.1 no.1
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    • pp.6-12
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    • 2011
  • BIM(Building Information Modeling) technologies are the most effective for the maintenance of infrastructures because they provide information sharing througout the life-cycle of structures and support close communication between different project stages. Systematic and well-organized data play a fundamental role for the effective maintenance of subway tunnel. In this paper, 3D information models for maintenance of BIM-based subway tunnel structures are developed. Standard classifications for the maintenance and construction information classification system were adopted. A classification system based on construction information classification system was built considering procedures of maintenance work. It provides optimization and standardization of the work flow for the maintenance of subway structures by applying information modeling processes instead of the current maintenance practices. It can effectively reduces the life cycle cost and time for the maintenance. The proposed system can be utilized for the maintenance history management to enhance current maintenance system.

Effect of poly(lactide-co-glycolide) (PLGA) on bone regeneration in rabbit calvaria (토끼 두개골 결손부의 골재생에 대한 poly(lactide-co-glycolide) (PLGA) 의 영향)

  • Park, Jae-Young;Hwang, Woo-Jin;Jeong, Seong-Nyum;Kim, Yun-Sang;Pi, Sung-Hee;You, Hyung-Keun;Shin, Hyung-Shik
    • Journal of Periodontal and Implant Science
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    • v.39 no.2
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    • pp.167-176
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    • 2009
  • Purpose: The purpose of this study is to histologically and histomorphometrically evaluate the effect of PLGA on bone regeneration compared with bone graft material. Methods: The experimental study was conducted in 10 rabbits with 2 different healing periods of 2 and 4 weeks. Following surgical exposure of the calvarium, 4 circular bone defects with a diameter of 4.6mm were formed. Rabbits were divided into control group, test groups I, and II. 10 defects assigned to the test group Ⅰ were grafted with Nu-oss and other 10 defects assigned to the test group II were grafted with PLGA. The rest of the defects were in the negative control group. At 2nd and 4th week after surgery, 10 rabbits were sacrificed through intracardiac perfusion and then specimens were obtained. Histological analysis was performed following staining with trichorme and transversal sectioning of the calvarial bone. Results: A group which used PLGA showed tissue reactions characterized by severe inflammation, rather than distinctive new bone formation. Conclusions: The present experimental investigations have failed to prove any beneficial effects of PLGA. PLGA used in this study exhibited foreign body reactions and a less favorable pattern of new bone formation in comparison to control group. Conclusion: PLGA did not function as scaffold. Further investigations of many types of micro PLGA that could improve its potential in GBR procedures are needed.

A Comparative Study of 3D MT Modeling Methods (3차원 MT 모델링 기법의 비교 분석)

  • Han, Nu-Ree;Nam, Myung-Jin;Kim, Hee-Joon;Song, Yoon-Ho;Suh, Jung-Hee
    • Geophysics and Geophysical Exploration
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    • v.10 no.2
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    • pp.154-160
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    • 2007
  • This paper compares the characteristics of three different algorithms for three-dimensional (3D) magnetotelluric (MT) modeling. These methods are developed by Mackie et al. (1994), Sasaki (1999) and Nam et al. (2007). The first and second methods are based on the finite difference method (FDM), while the last one the finite-element method (FEM). MT responses, apparent resistivities and phases, for a COMMEMI 3D-2 model show a good agreement with integral equation solutions and only minor discrepancies are found over the anomalous bodies in the 3D model. The computation time of the two methods based on FDM is short and the static divergence correction contributes to speed up. The FEM modeling scheme is accurate but slow.

A Performance Test for Assessment of the RFID/USN Inter-working System's Applicability to the Construction Industry (RFID/USN 연동 시스템의 건설 산업 적용을 위한 성능 실험에 관한 연구)

  • Yoo, Ji-Yeon;Choi, Nu-Ri;Kim, Chang-Wan;Kim, Hyoung-Kwan;Han, Seung-Heon;Kim, Moon-Kyum
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2007.11a
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    • pp.880-885
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    • 2007
  • In the last decades, the resource used in the construction process has become much more various in kinds and increased in number as construction has become enlargement and complexity. Resource management on a construction site has been recognized as a detrimental factor to influence project success, therefore various technologies have been applied by the construction industry to streamline resource management. RFID/USN interworking system composed of RFID technology and sensor network supports automation of resource management and real-time information networking. Most of research efforts for RFID technology in the construction industry have been limited to object identification technology. The study proposed herein it to verify the applicability of RFID/USN interworking system to the construction industry. The identification rates of RFID/USN interworking system by distance and degree and by type of materials was identified and analyzed.

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A study on the heat transfer characteristics of swirling flow in a circular sectioned $180^{\circ}C$bend with uniform heat flux (균일 열플럭스가 있는 $180^{\circ}C$ 원형단면 곡관의 선회유동 열전달특성 연구)

  • Lee, Sang-Bae;Gwon, Gi-Rin;Jang, Tae-Hyeon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.5
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    • pp.615-627
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    • 1997
  • An experiment was performed to local heat transfer coefficient and Nusselt number in the circular duct of 180.deg. bend for Re=6*10$^{4}$, 8*10$^{4}$ and 1*10$^{5}$ at swirling flow and non-swirling flow conditions. The test tube with circular section was made by stainless which has curvature ratio 9.4. The wall of test tube was heated directly by electrical power to 3.51 kw and swirling motion of air was produced by a tangential inlet to the pipe axis at the 180 degree. Measurements of local wall temperatures and bulk mean temperature of air are made at four circumferential positions in the 16 stations. The wall temperatures show particularly reduced distribution curve at bend for non-swirling flow but this effect does not appear for swirling flow. Nusselt number distributions for swirling flow which was calculated from the measured wall and bulk temperatures were higher than that of non-swirling flow. Average Nusselt number of swirling flow increased about 90 ~ 100% than that of non-swirling flow whole through the test tube. The Nu/N $u_{DB}$ values at the station of 90.deg. for non-swirling flow and swirling flow are respectively about 2.5 and 4.8 at Re=6*10$^{4}$. Also that is good agreement with Said's result for non-swirling flow. flow.

Effects of Nutrition Education on Diet Control Program S-28 (다이어트프로그램 S-28에 대한 영양교육의 효과)

  • 이혜양
    • The Korean Journal of Food And Nutrition
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    • v.12 no.1
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    • pp.39-42
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    • 1999
  • This study was carried out to investigate effects of nutrition education on diet program S-28 for a per-iod of 5 months. The participants in this diet program were 40 Chungkang college female students with over 30% body fat. During the first 2 weeks they were provided 800kcal a day and 1,200kcal a day for the lat 2 weeks. Since then weight maintenance program was continued. Exercise and nutrition e여-cation program for nutrition knowledge attitude and food habit were conducted during the entire test period, Results during the test period were as follows : 1) Weight loww was statistically significant from 69.5$\pm$4.9kg at the beginning to65.6$\pm$3.0kg(P<0.01) in 3 months to 63.2$\pm$3.5kg(P<0.01) in the 5th month. 2) Obesity rate was significantly decreased from 23.9$\pm$12.1% to 21.3$\pm$9.2%(P<0.05) in 3 mon-ths to 19.7$\pm$8.5% in the 5th month. 3) BMI was significantly declined from 27.3$\pm$1.5kg/m2 to 26.1$\pm$1. 2kg/m2(P<0.01) in 3 months to 25.7$\pm$0.9kg/m2(P<0.05) in 3 months to 28.2$\pm$1.8%(p<0.05) in the 5th month. 5) The mean scores of food habit were 33.4$\pm$4.5 at the beginning 35.2$\pm$3.7 in 3 mon-손 37.4$\pm$4.0 in the 5th month and each of nutrition attitude was 53.8$\pm$5.3, 58.0$\pm$6.2. There-fore these data showed that effects of nutrition education on diet program S-28 were feflected remark-ably not only in the antropmetric measurements but also in the mean scores of food habit and nu-trition attitude.

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Ionesco et Roumanie (이오네스코와 루마니아)

  • PARK, hyung-sub
    • Cross-Cultural Studies
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    • v.26
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    • pp.95-121
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    • 2012
  • Ce travail est de rechercher la vie litteraire d'Eug?ne Ionesco ? l'?poque de la Roumanie(1921~1937). Ionesco fait partie d'une cat?gorie d'?crivains(Mircea Eliade, Emil Cioran, Tristan Tzara, Pana?t Istrati, etc) qui sont n?s en Roumanie et ont commenc? leur carri?re dans leur pays d'origine pour la continuer et l'achever en France. Eugen Ionescu devient Eug?ne Ionesco. Ce dernier repr?sente d?j? dans les ann?es 30 une personnalit? hors du commun. C'est un homme qui a deux patries, deux racines : une roumaine, une autre fran?aise. Sa vie est a ?t? marqu?e par ses publications des l'adolescence. Ils font l'objet de ce livre-portrait d'Eugen Ionescu, po?te et critique, ?crivain de langue roumaine. L'?tude de la jeunesse roumaine d'Ionesco nous m?ne sur un terrain p?rilleux, celui de la biographie, plus pr?cis?ment des ann?es d'adolescence, de jeunesse et d'apprentissage d'un ?crivain qui a masqu? cette p?riode de sa vie. Nous avons pr?fer? tracer une biographie intellectuelle plutot qu'?num?rer des d?tails anecdotiques. La projection d'Ionesco dans son oeuvre est le r?cit de ses propres aventures intellectuelles. Une part importante de notre travail est consacr?e ? l'anlayse d'un livre de critique Nu(Non) de jeune Ionesco. Nous avons utilis? le texte de la version fran?aise publi?e en 1986 pour ce travail. Pour Ionescu le Roumain, le po?te Ionesco, ?l?gies pour des ?tres minuscules, nous avons consult? une th?se d'Ecaterina Cleynen-Serghieve La jeunesse litt?raire d'Eug?ne Ionesco et puis l'?tude de Gelu Ionesco sur la carri?re roumaine d'Ionesco. Nous nous sommes aussi r?f?r?s ? divers documents comme Notes et contre-notes(1966), D?couvertes(1969), Journal en miettes et Pr?sent pass?, Pass? pr?sent(Mercure de France), et les entretiens avec Claude Bonnefoy pour comprendre la personnalit? d'un jeune ?crivain roumain.

An Architecture of a Dynamic Cyber Attack Tree: Attributes Approach (능동적인 사이버 공격 트리 설계: 애트리뷰트 접근)

  • Eom, Jung-Ho
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.21 no.3
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    • pp.67-74
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    • 2011
  • In this paper, we presented a dynamic cyber attack tree which can describe an attack scenario flexibly for an active cyber attack model could be detected complex and transformed attack method. An attack tree provides a formal and methodical route of describing the security safeguard on varying attacks against network system. The existent attack tree can describe attack scenario as using vertex, edge and composition. But an attack tree has the limitations to express complex and new attack due to the restriction of attack tree's attributes. We solved the limitations of the existent attack tree as adding an threat occurrence probability and 2 components of composition in the attributes. Firstly, we improved the flexibility to describe complex and transformed attack method, and reduced the ambiguity of attack sequence, as reinforcing composition. And we can identify the risk level of attack at each attack phase from child node to parent node as adding an threat occurrence probability.

Quality Characteristics of Byeolmijang Prepared by Different Variety of Roasted Grain Powders (볶은 잡곡 종류를 달리하여 제조한 별미장의 품질 특성)

  • Eom, Hyun-Ju;Kwon, Nu Ri;Kang, Hye Jeong;Park, Hye Jin;Kim, So-Young;Kim, Ju-Hyoung
    • The Korean Journal of Food And Nutrition
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    • v.35 no.2
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    • pp.106-115
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    • 2022
  • The purpose of this study was to examine the quality characteristics of byeolmijang prepared several roasted whole grain powders (oat, brown rice, black soybean, corn) for eight weeks. As the fermentation progressed, the pH decreased from 6.10~6.12 to 4.48~4.92 and the total acidity increased dramatically from 0.41~0.48% to 1.67~2.24%. There were no differences in the moisture content. The content of reducing sugar decreased, in particular, brown rice sample(C) decreased significantly than the other samples during fermentation. In color, L and b-value decreased all samples, whereas a-value showed a tendency to slightly increase. The total cell counts and lactic acid bacteria revealed an increasing tendency during fermentation. In case of the amino-type nitrogen contents, it increased significantly during the fermentation period, especially control sample (A) showed the highest content significantly. The total polyphenol of all samples increased in the fermentation period. ABTS and DPPH radical scavenging activities also increased, especially corn sample (E) had the highest levels. In by electronic tongue analysis, corn sample (E) revealed higher umami and sourness than the control. So, by adding roasted corn powder, it can enhance function and taste of byeolmijang.