• Title/Summary/Keyword: B.Arch

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Analysis and probabilistic modeling of wind characteristics of an arch bridge using structural health monitoring data during typhoons

  • Ye, X.W.;Xi, P.S.;Su, Y.H.;Chen, B.
    • Structural Engineering and Mechanics
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    • v.63 no.6
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    • pp.809-824
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    • 2017
  • The accurate evaluation of wind characteristics and wind-induced structural responses during a typhoon is of significant importance for bridge design and safety assessment. This paper presents an expectation maximization (EM) algorithm-based angular-linear approach for probabilistic modeling of field-measured wind characteristics. The proposed method has been applied to model the wind speed and direction data during typhoons recorded by the structural health monitoring (SHM) system instrumented on the arch Jiubao Bridge located in Hangzhou, China. In the summer of 2015, three typhoons, i.e., Typhoon Chan-hom, Typhoon Soudelor and Typhoon Goni, made landfall in the east of China and then struck the Jiubao Bridge. By analyzing the wind monitoring data such as the wind speed and direction measured by three anemometers during typhoons, the wind characteristics during typhoons are derived, including the average wind speed and direction, turbulence intensity, gust factor, turbulence integral scale, and power spectral density (PSD). An EM algorithm-based angular-linear modeling approach is proposed for modeling the joint distribution of the wind speed and direction. For the marginal distribution of the wind speed, the finite mixture of two-parameter Weibull distribution is employed, and the finite mixture of von Mises distribution is used to represent the wind direction. The parameters of each distribution model are estimated by use of the EM algorithm, and the optimal model is determined by the values of $R^2$ statistic and the Akaike's information criterion (AIC). The results indicate that the stochastic properties of the wind field around the bridge site during typhoons are effectively characterized by the proposed EM algorithm-based angular-linear modeling approach. The formulated joint distribution of the wind speed and direction can serve as a solid foundation for the purpose of accurately evaluating the typhoon-induced fatigue damage of long-span bridges.

Dental Treatment of Child with Hemophilia (혈우병을 가진 어린이의 치과치료)

  • Lim, Ji Eun;Lee, Soo Eon;Ahn, Hyo Jung;Park, Jae-Hong;Choi, Sung Chul
    • Journal of The Korean Dental Society of Anesthesiology
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    • v.12 no.4
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    • pp.229-233
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    • 2012
  • Hemophilia, the most common of the inherited bleeding disorder, is the result of a deficiency of clotting factor. Since bleeding after dental treatment may cause severe or even fatal complications, people with hemophilia must be given special dental care. We report on the diagnosis and treatment of a 9-year-old boy having severe hemophilia visited our department with the chief complaints of pus discharge on the left lower molar region. In the clinical and radiographic examination, periapical abscess and dental caries were diagnosed. Considering complexity of the treatment and complication in the coagulation, it was decided to carry on the treatment under general anesthesia. Clotting factor IX concentrates were intended to provide 50-70% plasma level. Pulpectomy, resin restoration and Stainless steel crown were given under general anesthesia. Several teeth were extracted and the sockets were packed with Surgicel$^{(R)}$ (Oxidized Regenerated Cellulose, Johnson and Johnson Co. Neuchatel, Switzerland) under general anesthesia. Transpalatal arch and lingual arch were given for maintaining the extracted space before discharged. For people with severe hemophilia, factor replacement is necessary before scaling, surgery or regional block injections. Therefore, if several extractions are needed, dental care under general anesthesia would be effective and efficient management.

A Study on the Architectural Characteristics Revived from the Roman Architecture - Focused on the early Renaissance Architecture Building - (로마시대 건축으로부터 재생된 건축적 특성에 관한 연구 - 초기 르네상스시대 건축물을 중심으로 -)

  • Kim, Seok-Man
    • Journal of architectural history
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    • v.18 no.2
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    • pp.7-26
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    • 2009
  • The purpose of this paper is the study on the architectural characteristics revived from the roman architecture, focused on the early renaissance architecture building. The results of study are as follow: 1. The composition system of Domus which is formed of urban house in the Roman period is presented by spatial arrangement of palace architecture centering around atrium in the Renaissance period. Thus plan type of Domus is used by atrium from which is composed of peristyle from the palace and villa in the Renaissance period. 2. The circular temple in the Roman period is composed of element such as podium, stair, peristyle centering around the basic circular plan. Bramante planed to revive above elements for the Tempietto to concept from the circular temple in the Roman period. 3. The triumphal arch in the Roman period is strong monument to the independent building in the city, but thus arch is used of church facade as the important example which is composed with building elevation in the Renaissance period. 4. The composition system and element of Roman temple which is planned to rectangular plan is composed of high podium, stair, portico, prostyle and pediment. The facade plan of church is used by the partial elements and total elements perfectly from the temple in the Roman period. 5. The linearly successive and repetitive composition which is composition system and element of aqueduct arches of same dimension shows to the palace facade, arcade for gallery space and side elevation plan of S.Fracesco church. 6. Such as background of Colloseum, Rucellai palace can be called good example which is created by the new architectural form to the creative starting point from the classical architecture from.

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Reliability, accuracy of evaluations obtained from CEREC$^{(R)}$ AC system digital impression: an in-vitro study (CEREC$^{(R)}$ AC system으로 채득된 디지털 인상의 재현성, 정확성 평가에 관한 연구)

  • Kim, Jae-Hong;Kim, Ki-Baek;Kim, Hae-Young;Kim, Jung-Ae;Kim, Woong-Chul;Kim, Ji-Hwan
    • Journal of Technologic Dentistry
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    • v.34 no.2
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    • pp.121-128
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    • 2012
  • Purpose: The aim of this study was to determine the reliability and accuracy of measurements in digital models(CEREC$^{(R)}$ AC) compared to stone models. Methods: A master model(500B-1, Nissin Dental Product, Japan) with the prepared upper full arch tooth was used. Conventional impression and then stone model(n=10) were produced from this master model, and on the other hands, digital impressions were made with the CEREC$^{(R)}$ AC intra-oral scanner(n=10). One examiner measured two times the intercanine, intermolar distance, dental arch length. The stone model were measured using a digital caliper. The t-student test for paired samples and intraclass correlation coefficient(ICC) were used for statistical analysis. Results: The measurement of two methods showed very good reliability. At the intra-examiner reliability of measurement, ICC at the stone and CEREC$^{(R)}$ AC model were 0.81 and 0.94. The mean difference between measurements made directly on the stone models and those made on the CEREC$^{(R)}$ AC model was 0.20~0.28mm, and was statistically significant(P=0.001). Conclusion: These in vitro studies show that accuracy of the digital impression is similar to that of the conventional impression. These results will have to be confirmed in further clinical studies.

Strain-based structural condition assessment of an instrumented arch bridge using FBG monitoring data

  • Ye, X.W.;Yi, Ting-Hua;Su, Y.H.;Liu, T.;Chen, B.
    • Smart Structures and Systems
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    • v.20 no.2
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    • pp.139-150
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    • 2017
  • The structural strain plays a significant role in structural condition assessment of in-service bridges in terms of structural bearing capacity, structural reliability level and entire safety redundancy. Therefore, it has been one of the most important parameters concerned by researchers and engineers engaged in structural health monitoring (SHM) practices. In this paper, an SHM system instrumented on the Jiubao Bridge located in Hangzhou, China is firstly introduced. This system involves nine subsystems and has been continuously operated for five years since 2012. As part of the SHM system, a total of 166 fiber Bragg grating (FBG) strain sensors are installed on the bridge to measure the dynamic strain responses of key structural components. Based on the strain monitoring data acquired in recent two years, the strain-based structural condition assessment of the Jiubao Bridge is carried out. The wavelet multi-resolution algorithm is applied to separate the temperature effect from the raw strain data. The obtained strain data under the normal traffic and wind condition and under the typhoon condition are examined for structural safety evaluation. The structural condition rating of the bridge in accordance with the AASHTO specification for condition evaluation and load and resistance factor rating of highway bridges is performed by use of the processed strain data in combination with finite element analysis. The analysis framework presented in this study can be used as a reference for facilitating the assessment, inspection and maintenance activities of in-service bridges instrumented with long-term SHM system.

The study on the dimensional stability of digitized dental stone replicas according to difference color of gypsum materials (치과용 모형재 색상에 따른 디지털 모형의 체적 안정성 연구)

  • Choi, Seog-Soon;Kim, Ki-Baek;Lee, Gyeong-Tak;Jeon, Jin-Hun;Kim, Jae-Hong
    • Journal of Technologic Dentistry
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    • v.34 no.4
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    • pp.369-377
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    • 2012
  • Purpose: The aim of study was to compare the dimensional stability of digitized dental stone replica using different color of gypsum materials using a white light scanner with three-dimensional software. Methods: A master model(500B-1, Nissin dental product, Japan) with the prepared lower full arch tooth was used. Several type IV stones(white, yellow, green) were used for 30 stone casts(10 casts each) duplicated a master model of mandible. The master model and the replicas were digitized with the non-contacting white light scanner to create 3-dimensional digital models. The linear distance between the reference points were measured and analyzed on the Delcam Copycad$^{(R)}$(Delcam plc, UK) 3D graphic software. One-way analysis of variance(ANOVA) combined with a Tukey multiple-range test were used to analysis the data(${\alpha}$=0.05). Results: There were considerable differences in mean values between gypsum materials within each color(white, yellow, green), and this difference was statistically significant, p=0.001. Conclusion: Digitization of dental materials on optical scanner was affected by color. Three different color of gypsum materials showed clinically acceptable accuracies of full arch digital model produced by them. Besides, these results will have to be confirmed in further clinical studies.

Suggestion of a Design Method for UAM (강관 다단 그라우팅 공법(UAM)의 설계법 제안)

  • 박이근;임종철
    • Journal of the Korean Geotechnical Society
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    • v.20 no.3
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    • pp.97-106
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    • 2004
  • In case of tunnel construction with a shallow soil cover in cohesionless soils or highly weathered rocks, reinforcement measures are required for a tunnel stability during the tunnel construction. Recent developments show that the use of Umbrella Arch Method(UAM) as tunnel reinforcement and water cut-off in domestic projects has increased. Unfortunately, guidelines for the design and construction of UAM have not been established, only empirical designs and applications in tunnel construction have been performed so far. In this study, behaviour of the steel pipes installed on the tunnel roof was analyzed through the monitoring of bending and axial stresses of the pipes with the advance of the tunnel face. The monitoring results were used in the establishment of the loading mechanism around the pipe. This paper suggests, the guidelines used in the determination of the total length, overlapping length and lateral spacing of the reinforcing pipes obtained from the established loading mechanism.

Statistical analysis and probabilistic modeling of WIM monitoring data of an instrumented arch bridge

  • Ye, X.W.;Su, Y.H.;Xi, P.S.;Chen, B.;Han, J.P.
    • Smart Structures and Systems
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    • v.17 no.6
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    • pp.1087-1105
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    • 2016
  • Traffic load and volume is one of the most important physical quantities for bridge safety evaluation and maintenance strategies formulation. This paper aims to conduct the statistical analysis of traffic volume information and the multimodal modeling of gross vehicle weight (GVW) based on the monitoring data obtained from the weigh-in-motion (WIM) system instrumented on the arch Jiubao Bridge located in Hangzhou, China. A genetic algorithm (GA)-based mixture parameter estimation approach is developed for derivation of the unknown mixture parameters in mixed distribution models. The statistical analysis of one-year WIM data is firstly performed according to the vehicle type, single axle weight, and GVW. The probability density function (PDF) and cumulative distribution function (CDF) of the GVW data of selected vehicle types are then formulated by use of three kinds of finite mixed distributions (normal, lognormal and Weibull). The mixture parameters are determined by use of the proposed GA-based method. The results indicate that the stochastic properties of the GVW data acquired from the field-instrumented WIM sensors are effectively characterized by the method of finite mixture distributions in conjunction with the proposed GA-based mixture parameter identification algorithm. Moreover, it is revealed that the Weibull mixture distribution is relatively superior in modeling of the WIM data on the basis of the calculated Akaike's information criterion (AIC) values.

Operative treatment of aortic dissections - Experience with 27 patients over a 5-year period - (대동맥 박리증의 수술요법 -27례의 수술환자를 대상으로 한 5 년간의 성적-)

  • Kim, Jhin-Gook;Ahn, Hyuk
    • Journal of Chest Surgery
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    • v.21 no.3
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    • pp.497-509
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    • 1988
  • Current therapy of aortic dissections remains unstandardized because of the relative rarity of these catastrophic events and conflicting reported results of various therapeutic strategies. Hence, we reviewed our current results and planned to purify our method of interpretation of results and so, to standardize therapeutic managements. This study comprised unselected, consecutive 27 patients with aortic dissections who were operated at Seoul National University Hospital from Jan 1983 to March 1988. The results from analysis of their preoperative, operative and postoperative finding were as follows: 1] 7 patients had acute type A, 14 had chronic type A, 4 had acute type B, and 2 had chronic type B. 2] The causes of dissections were unclear, but 8 patients had Marfan`s syndromes, 2 had previous operative histories on cardiovascular systems and 2 had congenital heart diseases. 3] Multiple preoperative variables were found to correlate significantly with operative mortality and complications. The prevalences of such preoperative major complicating factors were significantly more frequent in acute than chronic [P < 0.05] and type A than type B [P < 0.01]. 4] Operations were performed according to the type of the dissections and whether it was acute or chronic. Usually dacron tube graft replacements were performed[25/26]. Intraluminal sutureless graft replacement was performed in 11 patients. Of the 14 patients with combined aortic regurgitation, concomitant aortic valve resuspension in 4, seperative aortic valve replacement in 1, and aortic valve replacement with coronary reimplantation were performed in 9 patients. 2 patients had concomitant arch vessel managements. 5] Over-all operative mortality rate was 33% and 54% for acute type A, 25% for acute type B, 29% for chronic type A, 0% for chronic type B respectively. The main causes of operative mortality were cardiovascular complications [mainly CPB-weaning failure] in acute cases and hemorrhagic complications in chronic cases.

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Effect of Nelumbo nucifera Leaves on Hyperlipidemic and Atherosclerotic Bio F1B Hamster (고지혈증 및 동맥경화 감응 Bio F1B 햄스터에서 연잎(Nelumbo nucifera)의 지질저하 효과)

  • Kim, Sung-Bin;Rho, Sung-Bae;Rhyu, Dong-Young;Kim, Dong-Wook
    • Korean Journal of Pharmacognosy
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    • v.36 no.3 s.142
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    • pp.229-234
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    • 2005
  • Nelumbo nucifera Gaertner leaf (NNL) has been known that is effective to lowering blood pressure and hyperlipidemic levels. But, its pharmacological actions have not been demonstrated. Therefore, the present research was performed to find the effect of NNL on hyperlipidemic actions in Bio F1B hamster as a model for hyperlipidemia and atherosclerosis. The hyperlipidemic hamster were induced by basal diet containing 10% coconut oil and 0.05% cholesterol with high fat atherogenic diet(HFAD). A control group and treated groups NNL100, 200, 400 mg/kg/day were fed a HFAD, but a normal group was fed a basal diet only. In conclusion, the serum total cholesterol levels were significantly declined on day 40 in F1B hamster given the NNL extracts (200, 400 mh/kg/day) with p<0.05, when compared with a control value of HFAD fed hamsters. The hepatic TC level was significantly lower in NNL 200 and 400 mg/kg/day group than of control hamster on day 40. But, the HDL levels were not changed between control and treated NNL groups. The TG levels of NNL treated groups showed a decrease tendency compare to the control value. In addition, accumulation of fatty level showed a slight decline to NNL treated groups in aortic arch.