• 제목/요약/키워드: general off

검색결과 780건 처리시간 0.027초

Basic Research on BIM-Based Quantity Take-off Guidelines

  • Yun, Seokheon;Kim, Sangchul
    • Architectural research
    • /
    • 제15권2호
    • /
    • pp.103-109
    • /
    • 2013
  • Various types of building information should be linked to 3D model objects for their effective use by stakeholders. Because Building Information Modeling (BIM) based on 3D is used by different stakeholders, the created BIM need standard guidelines for each purpose, as, for example, for quantity take-off. Thus, this study was conducted to propose guidelines for BIM modeling for quantity take-off in the framework, especially, in the concrete and form. The proposed guidelines adopted each element of the BIM model based on an analysis of the problem of the general BIM model. Moreover, the usability and accuracy of the reinforced structure modeling guidelines were verified by comparing the quantity of the commercial estimation software and the modeling quantity using the proposed modeling guidelines.

공기윤활 범프포일 저널 베어링의 내구성 특성에 관한 연구 (A Study on the Durability Characteristics of an Air-lubricated Bump Foil Journal Bearing)

  • 이용복;김태호;김창호;이남수;장건희
    • Tribology and Lubricants
    • /
    • 제18권2호
    • /
    • pp.153-159
    • /
    • 2002
  • This paper describes a durability characteristics of an air-lubricated bump foil journal bearing for high speed turbomachinerys at room temperature. At first, lift-off test and load capacity test were performed to understand the general characteristics of an air-lubricated bump foil Journal bearing. A 52 N weighted bump foil bearing sleeve was lilted off from a rotating Journal at about 3,000 rpm, and produced a load capacity of 500 N at an operating speed of 15,000 rpm. The next was 500 cycles lift-off test with an air-lubricated bump foil journal bearing that had a molybdenum disulfide(MoS$_2$) solid lubricant coated top foil. Data from measuring bearing torque and temperature and the observation of rubbing surfAce were included in results. Therefore the results of this work will aid in proving durability of air-lubricated bump foil journal bearings.

공기윤활 범프포일 저널 베어링의 내구성 특성에 관한 연구 (A Study on the Durability Characteristics of an Air-lubricated Bump Foil Journal Bearing)

  • 김태호;이용복;김창호;이남수;장건희
    • 한국윤활학회:학술대회논문집
    • /
    • 한국윤활학회 2001년도 제34회 추계학술대회 개최
    • /
    • pp.212-219
    • /
    • 2001
  • This paper describes a durability characteristics of an air-lubricated bump foil journal bearing for high speed turbomachinerys at room temperature. At first, lift-off test and load capacity test were performed to understand the general characteristics of an air-lubricated bump foil journal bearing. A 52N weighted bump foil bearing sleeve was lifted off from a rotating journal at about 3,000rpm, and produced a load capacity of 500N at an operating speed of 15,000rpm. The next was 500 cycles lift-off test with an air-lubricated bump foil journal bearing that had a molybdenum disulfide(MoS$_2$) solid lubricant coated top foil. Data from measuring bearing torque and temperature and the observation of rubbing surface were included in results. Therefore the results of this work will aid in proving durability of air-lubricated bump foil journal bearings.

  • PDF

Pinch-Off Syndrome, a Rare Complication of Totally Implantable Venous Access Device Implantation: A Case Series and Literature Review

  • Ilhan, Burak Mehmet;Sormaz, Ismail Cem;Turkay, Rustu
    • Journal of Chest Surgery
    • /
    • 제51권5호
    • /
    • pp.333-337
    • /
    • 2018
  • Background: Pinch-off syndrome (POS) is a rare complication after totally implantable venous access device (TIVAD) implantation. In cancer patients, it is important to prevent this rare complication and to recognize it early if it does occur. We present a case series of POS after TIVAD implantation and the results of a literature search about this complication. Methods: From July 2006 to December 2015, 924 permanent implantable central venous catheter implantation procedures were performed. The most common indication was vascular access for chemotherapy. Results: POS occurred in 5 patients in our clinic. Two patients experienced POS within 2 weeks, and the other 3 patients were admitted to department of surgery, Istanbul Faculty of Medicine at 6 to 14 months following implantation. The catheters were found to be occluded during medication administration, and all patients complained of serious pain. The transected fragments of the catheters had migrated to the heart. They were successfully removed under angiography with a single-loop snare. Conclusion: POS is a serious complication after TIVAD implantation. It is important to be aware of this possibility and to make an early diagnosis in order to prevent complications such as drug extravasation and occlusion events.

터빈입구온도 보정기법을 적용한 가스터빈 성능진단 프로그램 개발 (Development of a Performance Diagnosis Program for Gas Turbines Using Turbine Inlet Temperature Correction)

  • 이재홍;강도원;김동섭
    • 한국유체기계학회 논문집
    • /
    • 제20권2호
    • /
    • pp.32-40
    • /
    • 2017
  • In this study, an in-house program to analyze the performance degradation for gas turbines is developed using MATLAB and is validated using commercial software. This program consists of design and off-design calculations. The results of design calculation is used for reference values of off-design calculation. The off-design calculation is composed of measured and expected performance analyses, and turbine inlet temperature correction. In general, performance degradation is analyzed by comparing the results of measured and expected performance analysis. However, if gas turbine performance degrades, turbine inlet temperature might increase due to the general control logic to comply with the power demand. Therefore, it is required to consider the deviation of turbine inlet temperature from the normal value in the performance diagnosis to analyze the performance degradation exactly. In this study, a special effort is given to the correction of turbine inlet temperature. The accuracy of the developed program is confirmed by comparison with commercial software, and its capability of performance diagnosis using the turbine inlet temperature correction is demonstrated.

비대칭 원주방향 관통균열 배관의 탄소성 J-적분 계산식 (Elastic-Plastic J Estimations for Pipes with Off-Centred Circumferential Through-Wall Cracks)

  • 심도준;허남수;김윤재;김영진
    • 대한기계학회논문집A
    • /
    • 제27권7호
    • /
    • pp.1170-1178
    • /
    • 2003
  • This paper provides approximate J estimates for off-centred, circumferential through-wall cracks in cylinders under bending and under combined tension and bending. The proposed method is based on the reference stress approach, where the dependence of elastic and plastic influence functions of J on the cylinder/crack geometry, the off-centred angle and strain hardening is minimised through the use of a proper normalising load. Based on published limited FE results for off-centred, circumferential through-wall cracks under bending, such normalising load is found, based on which the reference stress based J estimates are proposed for more general cases, such as for a different cylinder geometry and for combined loading. Comparison of the estimated J with extensive FE J results shows overall good agreements for different crack/cylinder geometries and for combined tension and bending, which provides sufficient confidence in the use of the proposed method to fracture mechanics analyses of off-centred circumferential cracks. Furthermore, the proposed method is simple to use, giving significant merits in practice.

Rationally designed siRNAs without miRNA-like off-target repression

  • Seok, Heeyoung;Jang, Eun-Sook;Chi, Sung Wook
    • BMB Reports
    • /
    • 제49권3호
    • /
    • pp.135-136
    • /
    • 2016
  • Small interfering RNAs (siRNAs) have been developed to intentionally repress a specific gene expression by directing RNA-induced silencing complex (RISC), mimicking the endogenous gene silencer, microRNAs (miRNAs). Although siRNA is designed to be perfectly complementary to an intended target mRNA, it also suppresses hundreds of off-targets by the way that miRNAs recognize targets. Until now, there is no efficient way to avoid such off-target repression, although the mode of miRNA-like interaction has been proposed. Rationally based on the model called "transitional nucleation" which pre-requires base-pairs from position 2 to the pivot (position 6) with targets, we developed a simple chemical modification which completely eliminates miRNA-like off-target repression (0%), achieved by substituting a nucleotide in pivot with abasic spacers (dSpacer or C3 spacer), which potentially destabilize the transitional nucleation. Furthermore, by alleviating steric hindrance in the complex with Argonaute (Ago), abasic pivot substitution also preserves near-perfect on-target activity (∼80-100%). Abasic pivot substitution offers a general means of harnessing target specificity of siRNAs to experimental and clinical applications where misleading and deleterious phenotypes from off-target repression must be considered.

비대칭 원주방향 관통균열 배관의 탄소성 파괴역학해석 (Elastic-Plastic Fracture Mechanics Analysis of Off-Centred Circumferential Through-Wall Cracked Pipes)

  • 심도준;허남수;김윤재;김영진
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2003년도 춘계학술대회
    • /
    • pp.125-130
    • /
    • 2003
  • This paper provides approximate J estimates for off-centred, circumferential through-wall cracks in cylinders under bending. The proposed method is based on the reference stress approach, where the dependence of elastic and plastic influence functions of J on the cylinder/crack geometry, the off-centred angle and strain hardening is minimised through the use of a proper normalising load. Based on published limited FE results for off-centred, circumferential through-wall cracks under bending, such normalising load is found, based on which the reference stress based J estimates are proposed for more general cases, such as for a different cylinder geometry. Comparison of the estimated J with extensive FE J results shows overall good agreements for different crack/cylinder geometries which provides sufficient confidence in the use of the proposed method to fracture mechanics analyses of off-centred circumferential cracks. Furthermore, the proposed method is simple to use, giving significant merits in practice.

  • PDF

PROTO-MODEL OF AN INFRARED WIDE-FIELD OFF-AXIS TELESCOPE

  • Kim, Sang-Hyuk;Pak, Soo-Jong;Chang, Seung-Hyuk;Kim, Geon-Hee;Yang, Sun-Choel;Kim, Myung-Sang;Lee, Sung-Ho;Lee, Han-Shin
    • 천문학회지
    • /
    • 제43권5호
    • /
    • pp.169-181
    • /
    • 2010
  • We develop a proto-model of an off-axis reflective telescope for infrared wide-field observations based on the design of Schwarzschild-Chang type telescope. With only two mirrors, this design achieves an entrance pupil diameter of 50 mm and an effective focal length of 100 mm. We can apply this design to a mid-infrared telescope with a field of view of $8^{\circ}{\times}8^{\circ}$. In spite of the substantial advantages of off-axis telescopes in the infrared compared to refractive or on-axis reflective telescopes, it is known to be difficult to align the mirrors in off-axis systems because of their asymmetric structures. Off-axis mirrors of our telescope are manufactured at the Korea Basic Science Institute (KBSI). We analyze the fabricated mirror surfaces by fitting polynomial functions to the measured data. We accomplish alignment of this two-mirror off-axis system using a ray tracing method. A simple imaging test is performed to compare a pinhole image with a simulated prediction.

FUZZY REGRESSION TOWARDS A GENERAL INSURANCE APPLICATION

  • Kim, Joseph H.T.;Kim, Joocheol
    • Journal of applied mathematics & informatics
    • /
    • 제32권3_4호
    • /
    • pp.343-357
    • /
    • 2014
  • In many non-life insurance applications past data are given in a form known as the run-off triangle. Smoothing such data using parametric crisp regression models has long served as the basis of estimating future claim amounts and the reserves set aside to protect the insurer from future losses. In this article a fuzzy counterpart of the Hoerl curve, a well-known claim reserving regression model, is proposed to analyze the past claim data and to determine the reserves. The fuzzy Hoerl curve is more flexible and general than the one considered in the previous fuzzy literature in that it includes a categorical variable with multiple explanatory variables, which requires the development of the fuzzy analysis of covariance, or fuzzy ANCOVA. Using an actual insurance run-off claim data we show that the suggested fuzzy Hoerl curve based on the fuzzy ANCOVA gives reasonable claim reserves without stringent assumptions needed for the traditional regression approach in claim reserving.