• Title/Summary/Keyword: SAG2

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Aeroelastic Behaviors of Self-anchored Suspension Bridge with Lateral Sag of Main Cable(II) - Focused on the Behavior of Tower - (횡방향 새그를 가진 자정식 현수교의 공탄성 거동(II) - 주탑의 거동을 중심으로 -)

  • Kwon, Soon Duck;Chang, Sung Pil
    • Journal of Korean Society of Steel Construction
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    • v.9 no.2 s.31
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    • pp.269-275
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    • 1997
  • Wind tunnel test results and their interpretations, which were performed to study the aerodynamic stability of tower of self-anchored suspension bridge, are presented in this paper. Tower and full models were tested under smooth and turbulent flow conditions. In the case of the tower with inclined two columns, the vibration due to wakes were occurred at wide velocity zone because the wakes with various frequencies were generated by inclined upstream column. It has to be emphasized that the vibration characteristics of the tower in the self-anchored suspension bridge may be very sensitive to the longitudinal boundary conditions of the girder at the supports. Because of the two natural frequency of the tower, out-of-plane bending and torsional, were not well separated, coupled motions were observed in a wide range of wind velocity. The effectiveness of corner cut, countermeasure to reduce the tower vibrations, was also studied. It has been found that 1:10, comer cut size to column width, may be the most effective ratio for reducing the vibrations.

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Numerical study on the mitigation of rain-wind induced vibrations of stay cables with dampers

  • Li, Shouying;Wu, Teng;Li, Shouke;Gu, Ming
    • Wind and Structures
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    • v.23 no.6
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    • pp.615-639
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    • 2016
  • Although the underlying mechanism of rain-wind induced vibrations (RWIVs) of stay cables has not been fully understood, some countermeasures have been successfully applied to mitigating this kind of vibration. Among these, installing dampers near the bridge deck was widely adopted, and several field observations have shown its effectiveness. In this study, the effectiveness of dampers to RWIVs of stay cables is numerically investigated comprehensively by means of finite difference method (FDM). Based on the free vibration analysis of a taut string, it is found that the 3-points triangle scheme, which can be easily implemented in FDM, can offer an excellent approximation of the concentrated damping coefficient (expressed as a Dirac delta function) at the location where the damper is installed. Then, free vibration analysis of a 3-D continuous stay cable attached with two dampers is carried out to study the relationship of modal damping ratio and damping coefficient of the dampers. The effects of orientation of the dampers and cable sag on the modal damping ratio are investigated in detail. Finally, the RWIV response of a 3-D continuous stay cable attached with two dampers is examined. The results indicate that 0.5% of damping ratio is sufficient to reduce the RWIV vibration of the Cable A20 on the No.2 Nanjing Bridge over Yangtze River.

Development of Elastic Shaft Alignment Design Program (선체변형을 고려한 탄성 축계정렬 설계 프로그램 개발)

  • Choung Joon-Mo;Choe Ick-Heung
    • Journal of the Society of Naval Architects of Korea
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    • v.43 no.4 s.148
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    • pp.512-520
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    • 2006
  • The effects of flexibilities of supporting structures on shaft alignment are growing as ship sizes are Increasing mainly for container carrier and LNG carrier. But, most of classification societies not only do not suggest any quantitative guidelines about the flexibilities but also do not have shaft alignment design program considering the flexibility of supporting structures. A newly developed program, which is based on innovative shaft alignment technologies including nonlinear elastic multi-support bearing concept and hull deflection database approach, has S basic modules : 1)fully automated finite element generation module, 2) hull deflection database and it's mapping module on bearings, 3) squeezing and oil film pressure calculation module, 4) optimization module and 5) gap & sag calculation module. First module can generate finite element model including shafts, bearings, bearing seats, hull and engine housing without any misalignment of nodes. Hull deflection database module has built-in absolute deflection data for various ship types, sizes and loading conditions and imposes the transformed relative deflection data on shafting system. The squeezing of lining material and oil film pressures, which are relatively solved by Hertz contact theory and built-in hydrodynamic engine, can be calculated and visualized by pressure calculation module. One of the most representative capabilities is an optimization module based on both DOE and Hooke-Jeeves algorithm.

Investigations into the Influencing Fabric Properties Factors of the 3D Shape Evaluation of Korean Hanbok Chima

  • Park, Soon-Jee
    • International Journal of Human Ecology
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    • v.7 no.1
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    • pp.37-52
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    • 2006
  • This study was designed to analyze the three-dimensional shapes of Hanbok Chima made with various fabrics and to clarify the relationship between fabric properties as well as the objective and subjective evaluations of the 3D shape. For 3D shape data, a dress form (9A2 (N; nude)) was scanned with eight Chima garments made with the same number of fabrics. The scanner used was a non-contact three-dimensional human body measuring system belonging to Bunka Women's University in Japan. Data concerning the objective evaluation of the 3D shape was obtained from the measurements of the vertical and horizontal sections: those for subjective evaluation were through the sensory test after exposure to photographs from a front and side view. Four fabric factors were extracted from fabric physical properties: softness, extension, thickness of threads, and weight of fabric. Such factors as expansion (volume), sag of rear train, shape of nodes were influential in explaining the 3D shape of Hanbok Chima. From the analysis of the 3D shape, it can be deduced that with the constituent fabric stiffer, lighter, and less stretchable, the more expanded the 3D shape appeared to be. Multiple regression results showed that vertical shape factors have a greater effect on the evaluation of the 3D shape. It also implies that dependent variables of this study such as the subjective evaluation and 3D shape can be derived from regression equations on independent variables as fabric property factors or 3D shape factors. These results can enable the manufacturers to predict the 3D shape of the garment as well as the human subjective assessment to improve the efficacy of production. The investigation method proposed in this study can also be applicable to other garment items.

Distribution of KRAS and BRAF Mutations in Metastatic Colorectal Cancers in Turkish Patients

  • Gorukmez, Orhan;Yakut, Tahsin;Gorukmez, Ozlem;Sag, Sebnem Ozemri;Karkucak, Mutlu;Kanat, Ozkan
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1175-1179
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    • 2016
  • The results of this study demonstrate the potential prognostic and predictive values of KRAS and BRAF gene mutations in patients with colorectal cancer (CRC). It has been proven that KRAS and BRAF mutations are predictive biomarkers for resistance to anti-EGFR monoclonal antibody treatment in patients with metastatic CRC (mCRC). We demonstrated the distribution of KRAS (codons 12, 13 and 61) and BRAF (codon 600) gene mutations in 50 mCRCs using direct sequencing and compared the results with clinicopathological data. KRAS and BRAF mutations were identified in 15 (30%) and 1 (2%) patients, respectively. We identified KRAS mutations in codon 12, 13 and 61 in 73.3% (11/15), 20% (3/15) and 6.67% (1/15) of the positive patients, respectively. The KRAS mutation frequency was significantly higher in tumors located in the ascending colon (p=0.043). Thus, we found that approximately 1/3 of the patients with mCRC had KRAS mutations and the only clinicopathological factor related to this mutation was tumor location. Future studies with larger patient groups should yield more accurate data regarding the molecular mechanism of CRC and the association between KRAS and BRAF mutations and clinicopathological features.

Prototype Development of 3-Phase 3.3kV/220V 6kVA Modular Semiconductor Transformer (3상 3.3kV/220V 6kVA 모듈형 반도체 변압기의 프로토타입 개발)

  • Kim, Jae-Hyuk;Kim, Do-Hyun;Lee, Byung-Kwon;Han, Byung-Moon;Lee, Jun-Young;Choi, Nam-Sup
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.12
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    • pp.1678-1687
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    • 2013
  • This paper describes a prototype of 3-phase 3.3kV/220V 6kVA modular semiconductor transformer developed in the lab for feasibility study. The developed prototype is composed of three single-phase units coupled in Y-connection. Each single-phase unit with a rating of 1.9kV/127V 2kVA consists of a high-voltage high-frequency resonant AC-DC converter, a low-voltage hybrid-switching DC-DC converter, and a low-voltage hybrid-switching DC-AC converter. Also each single-phase unit has two DSP controllers to control converter operation and to acquire monitoring data. Monitoring system was developed based on LabView by using CAN communication link between the DSP controller and PC. Through various experimental analyses it was verified that the prototype operates with proper performance under normal and sag condition. The system efficiency can be improved by adopting optimal design and replacing the IGBT switch with the SiC MOSFET switch. The developed prototype confirms a possibility to build a commercial high-voltage high-power semiconductor transformer by increasing the number of series-connected converter modules in high-voltage side and improving the performance of switching element.

Prevalence of Toxoplasma gondii in Dogs in Zhanjiang, Southern China

  • Jiang, Hai-Hai;Li, Ming-Wei;Xu, Min-Jun;Cong, Wei;Zhu, Xing-Quan
    • Parasites, Hosts and Diseases
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    • v.53 no.4
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    • pp.493-496
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    • 2015
  • Toxoplasmosis, caused by Toxoplasma gondii, is a parasitic zoonosis with worldwide distribution. The present study investigated the prevalence of T. gondii in dogs in Zhanjiang city, southern China, using both serological and molecular detection. A total of 364 serum samples and 432 liver tissue samples were collected from the slaughter house between December 2012 and January 2013 and were examined for T. gondii IgG antibody by ELISA and T. gondii DNA by semi-nested PCR based on B1 gene, respectively. The overall seroprevalence of T. gondii IgG antibody was 51.9%, and T. gondii DNA was detected in 37 of 432 (8.6%) liver tissue samples. These positive DNA samples were analyzed by PCR-RFLP at 3'- and 5'-SAG2. Only 8 samples gave the PCR-RFLP data, and they were all classified as type I, which may suggest that the T. gondii isolates from dogs in Zhanjiang city may represent type I or type I variant. This study revealed the high prevalence of T. gondii infection in dogs in Zhanjiang city, southern China. Integrated measures should be taken to prevent and control toxoplasmosis in dogs in this area for public health concern.

THE STRUCTURE, STRATIGRAPHY AND PETROLEUM GEOLOGY OF THE MURZUK BASIN, SOUTHWEST LIBYA

  • JHO Jhoon Soo
    • 한국석유지질학회:학술대회논문집
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    • autumn
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    • pp.57-72
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    • 2000
  • The Murzuk Basin covers an area in excess of $350,000{\cal}km^2$, and is one of several intra-cratonic sag basins located on the Saharan Platform of North Africa. Compared with some of these basins, the Murzuk Basin has a relatively simple structure and stratigraphy, probably as a result of it's location on a the East Saharan Craton. The basin contains a sedimentary fill which reaches a thickness of about $4,000{\cal}m$ in the basin centre. This fill can be divided into a predominantly marine Paleozoic section, and a continental Mesozoic section. The principal hydrocarbon play consists of a glacial-marine sandstone reservoir of Cambro-Ordovician age, sourced and sealed by overlying Silurian shales. The present day borders of the basin are defined by tectonic uplifts, each of multi-phase generation, and the present day basin geometry bears little relation to the more extensive Early Palaeozoic sedimentary basin within which the reservoir and source rocks were deposited. The key to the understanding of the Cambro-Ordovician play is the relative timing of oil generation compared to the Cretaceous and Tertiary inversion tectonics which influenced source burial depth, reactivated faults and reorganised migration pathways. At the present day only a limited area of the basin centre remains within the oil generating window. Modelling of the timing and distribution of source rock maturity uses input data from AFTA and fluid inclusion studies to define palaeo temperatures, shale velocity work to estimate maximum burial depth and source rock geochemistry to define kinetics and pseudo-Ro. Migration pathways are investigated through structural analysis. The majority of the discovered fields and identified exploration prospects in the Murzuk Basin involve traps associated with high angle reverse faults. Extensional faulting occurred in the Cambro-Ordovician and this was followed by repeated compressional movements during Late Silurian, Late Carboniferous, Mid Cretaceous and Tertiary, each associated with regional uplift and erosion.

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Vibrational Characteristics on the Cables in Cable Stayed Bridge (사장교 케이블의 진동거동 특성)

  • Sung, Ikhyun
    • Journal of the Society of Disaster Information
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    • v.13 no.2
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    • pp.249-257
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    • 2017
  • Recently, a cable disconnection accident occurred due to a lightning strike at the Seohae Bridge located in Dangjin-Pyeongtaek City. This is a natural occurrence, but it is a recall that it is very important to review the safety issues due to the disconnection of cable bridges. In other words, the role of cables in cable bridges has a profound effect on the safety of the structure, and it has become necessary to grasp the effect on the entire structural system. The cable bridge is an economic bridge that builds the main tower and supports the bottom plate by cable. The influence of the cable is the main member, which is a big influence on the safety of the whole bridge system. In the cable-stayed bridge, the cables exhibit nonlinear behavior because of the change in sag, due to the dead weight of the cable, which occurs with changing tension in the cable resulting from the movement of the end points of the cable as the bridge is loaded. Modal analysis is conducted using the deformed dead-load tangent stiffness matrix. A new concept was presented by using divided a cable into several elements in order to study the effect of the cable vibration (both in-plane and swinging) on the overall bridge dynamics. The result of this study demonstrates the importance of cable vibration on the overall bridge dynamics.

A Study on the Actual Conditions of Brassiere Wearing for Girl Students

  • Sohn, Hee-Soon;Cha, Su-Joung
    • Journal of Fashion Business
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    • v.9 no.6
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    • pp.12-28
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    • 2005
  • The purpose of this study is to help develop high quality brassieres with functionality and comfort, fitting adolescents' physical features during their growth period. This study conducts a comparative analysis of juvenile brassiere and adult brassiere to identify the problems of brassieres in the market. The raw data for this study was processed by SPSS 10.1. The results of this study are summarized as follows: 1. The results of this survey show that the girls' satisfaction of their breasts has correlations between breast protrusion degree and volume. The girls think that if they have protrusive breasts their breast volume is big, and their breast satisfaction level shows high. 2. The results show that the objective of brassiere wearing is to prevent breasts sag and rupture, make good breast shape, balance their entire body shape, and make beautiful outer garment line. Brassiere functions are to prevent jiggle of breasts, make a good body line, and cover the nipples. For the grader school students, they are wearing brassiere to make a good balanced body and as their breasts developed, they are wearing brassiere for beautiful body shape not just to cover up their breasts. 3. In regard to brassiere cup size recognition, as students have higher grade at school, they have better recognition abouxt their cup size. As they are better aware of their cup size, they have better satisfaction with their cup size. Therefore, choosing the right size of brassiere for their bust is very important. 4. Girl students' brassiere preference shows that 317 students (56.9%) prefer white for brassiere colors, following pink and flesh color. Their most preferred brassiere material is cotton (354 people, 63.6%) because cotton is not sensitive even for weak skin. For brassiere style, 273 students (49%) prefer round style, following spots and mold. Their most preferred brassiere style is stake. In addition, brassiere should not press their breasts because their breasts are developing during puberty period.