• Title/Summary/Keyword: 3D Compression

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The UndrainBd Behavir or of Drilled Shaft Foundations Subjected to Static Inclined Loading (정적 경사하중을 받는 현장타설 말뚝기초의 비배수 거동)

  • ;Kulhawy, Fred H.
    • Geotechnical Engineering
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    • v.11 no.3
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    • pp.91-112
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    • 1995
  • Drilled shafts are used increasingly as the foundations for many types of structures. However, very little knowledge of drilled shaft behavior under inclined load is available. In this study, a systematic experimental testing program was conducted to understand the undrained behavior of drilled shaft foundations under inclined loads. A semi-theoretical method of predicting the inclined capacity was developed through a parametric study of the variables such as shaft geometry and load inclination. Test parameters were chosen to be representative of those most frequently used in the electric utility industry. Short, rigid shafts with varying depth/diameter(D/B) ratios were addressed, and loading modes were investigated that includes exial uplift, inclined uplift, and inclined compression loads. Capacities were evaluated using the structural interaction formula and an equation developed from this experimental study. This new equation models the laboratory data well and is applicable for the limites field data.

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Numerical simulation of hollow steel profiles for lightweight concrete sandwich panels

  • Brunesi, E.;Nascimbene, R.;Deyanova, M.;Pagani, C.;Zambelli, S.
    • Computers and Concrete
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    • v.15 no.6
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    • pp.951-972
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    • 2015
  • The focus of the present study is to investigate both local and global behaviour of a precast concrete sandwich panel. The selected prototype consists of two reinforced concrete layers coupled by a system of cold-drawn steel profiles and one intermediate layer of insulating material. High-definition nonlinear finite element (FE) models, based on 3D brick and 2D interface elements, are used to assess the capacity of this technology under shear, tension and compression. Geometrical nonlinearities are accounted via large displacement-large strain formulation, whilst material nonlinearities are included, in the series of simulations, by means of Von Mises yielding criterion for steel elements and a classical total strain crack model for concrete; a bond-slip constitutive law is additionally adopted to reproduce steel profile-concrete layer interaction. First, constitutive models are calibrated on the basis of preliminary pull and pull-out tests for steel and concrete, respectively. Geometrically and materially nonlinear FE simulations are performed, in compliance with experimental tests, to validate the proposed modeling approach and characterize shear, compressive and tensile response of this system, in terms of global capacity curves and local stress/strain distributions. Based on these experimental and numerical data, the structural performance is then quantified under various loading conditions, aimed to reproduce the behaviour of this solution during production, transport, construction and service conditions.

Clinical and Biochemical Profile of Monoclonal Gammopathies in Caribbean Patients in a Resource-limited Setting

  • Buchner-Daley, Loretta;Brady-West, Doreen;McGrowder, Donovan
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.12
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    • pp.6501-6504
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    • 2012
  • Background: Multiple myeloma is the most common malignant plasma cell dyscrasia and ranks second among primary haematological malignancies. This study describes the epidemiologic, clinical and pathologic profile of monoclonal gammopathies seen in the University Hospital of the West Indies (UHWI), a tertiary care referral centre. Materials and Method: A retrospective analysis of 85 cases diagnosed at UHWI over the 5-year period 2003-2007 was conducted. The cases were identified from the bone marrow records as well as the computerized database of the Medical Records Department. Clinical presentation, family and personal history and demographic data were retrieved. Haematological and biochemical results were also analyzed. Results: There were 85 patients diagnosed with monoclonal gammopathies. The M:F ratio was 1.2:1 and the mean age was $65.7{\pm}1.3$ years. Eighty percent of the patients had skeletal pain and 40% experienced weight loss. Of the patients experiencing bone pain 56.7% had multiple lytic lesions, 26.7% had pathological fractures and 26.7% had compression fractures. Seventy-four patients (87.1%) had a haemoglobin level <12.0 g/dL with 52.9% having values <8.0 g/dL. Renal impairment was evident at diagnosis in 36.5%. Hypercalcemia was seen in 26.5% and hyperuricemia in 45.9%. Of the 79 patients who had serum protein electrophoresis performed, 77.2% had at least one monoclonal band and of these 24.6% had a monoclonal protein also present on urine protein electrophoresis. Conclusions: The demographic profile in this group of patients is largely similar to other studies in predominantly Caucasian populations; however there was a notable increase in prevalence of severe disease at presentation, with the majority of patients presenting at the most advanced stage. It is probable that these differences reflect socioeconomic factors and not merely inherent ethnic variation in disease biology.

A Study on the Effectiveness of Injection in Environmentally-Friendly Bio-grouting with Soil Conditions (지반조건에 따른 친환경 바이오그라우팅 주입 효과에 관한 연구)

  • Kim, Daehyeon;Park, Kyung-Ho;Kim, Min-Seok;Kim, Sun-Hak
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.6
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    • pp.4276-4283
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    • 2015
  • The purpose of this research is to identify the effectiveness of injection with soil conditions by injecting CaCO3(created by microorganism reaction), which was recreated with equipment in similar situ condition. To analyze our research, we made 2 cases of single-layer (SP, SW) in D 150mm ${\times}$ H 300mm. Layers were made by RC 70, 80, 85, 90, 95% of soil condition. We measured uniaxial compression strength with cone penetrometer and watched injection range by checking a bulb formation around the injection nozzle. As a result, the relative compaction(RC) in more 85% were not injected in SW, we could identify the effect of bio-grouting technology on ground in relative compaction(RC) of injection ratio and cementation range.

Iso-density Surface Reconstruction using Hierarchical Shrink-Wrapping Algorithm (계층적 Shrink-Wrapping 알고리즘을 이용한 등밀도면의 재구성)

  • Choi, Young-Kyu;Park, Eun-Jin
    • Journal of KIISE:Computer Systems and Theory
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    • v.36 no.6
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    • pp.511-520
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    • 2009
  • In this paper, we present a new iso-density surface reconstruction scheme based on a hierarchy on the input volume data and the output mesh data. From the input volume data, we construct a hierarchy of volumes, called a volume pyramid, based on a 3D dilation filter. After constructing the volume pyramid, we extract a coarse base mesh from the coarsest resolution of the pyramid with the Cell-boundary representation scheme. We iteratively fit this mesh to the iso-points extracted from the volume data under O(3)-adjacency constraint. For the surface fitting, the shrinking process and the smoothing process are adopted as in the SWIS (Shrink-wrapped isosurface) algorithm[6], and we subdivide the mesh to be able to reconstruct fine detail of the isosurface. The advantage of our method is that it generates a mesh which can be utilized by several multiresolution algorithms such as compression and progressive transmission.

A Study on Noise Reduction of Rotary Compressor (공조용 로터리 압축기의 소음 저감에 관한 연구)

  • Ahn, B.H.;Kim, Y.S.
    • Journal of Power System Engineering
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    • v.3 no.3
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    • pp.60-69
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    • 1999
  • The noise and vibration sources of rotary compressor for room air-conditioner are pressure pulsation of compression process, cavity resonance of inner space, structural radiation noise of shell and impact noise of discharge valve. Among them, pressure pulsation is very important noise and vibration source. Because it transferred various kinds of noise and vibration like as mentioned above. In this reason, muffler and resonator are used in order to absorb and remove these noises. But an analytical prediction using acoustic analysis does not coincident with the experimental result. The difference between analysis and actual state is due to the assumption of analysis. This paper covered with new concept of muffler design based on the turbulence kinetic energy of flow by using CFD. From this analysis, it is possible to decide the best position of discharge port of muffler. Therefore $2{\sim}3dB$ noise reduction effect is acquired in rotary compressor of 5000 BTU grade. Also new approach of resonator design is suggested. From this study, the characteristics of resonator and surge hole (a kind of resonator without pipe length) are identified. The former is useful for pure tone noise (narrow frequency band), and the latter is effective for broad frequency band. This paper shows that it is very available to use 3 dimensional analysis of resonator in order to predict more exact tuning frequency. The result is proved by a lot of experiments. From combination of fluid analysis and acoustic analysis, up stream position is effective location of resonator concerning turbulence motion of fluid.

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인산 쌀 전분의 이화학적 특성

  • 정재홍;이미현;오만진
    • Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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    • 2003.10a
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    • pp.223.1-223
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    • 2003
  • 인산 쌀 전분을 제조, 이용하기 위한 기초 자료를 얻기 위하여 추청벼와 삼강벼를 원료로 하여 쌀 전분을 제조하고 이에 15% sodium tripolyphosphate를 가하여 15$0^{\circ}C$에서 30분간 반응시켜 얻어진 인산 쌀 전분(D. S.=0.015)의 이화학적 성질을 검토하였다. 인산 쌀 전분의 투명도는 원료 전분에 비하여 높았으며 원료 전분은 6$0^{\circ}C$, 인산 쌀 전분은 5$0^{\circ}C$부터 증가하기 시작하였다. 인산 쌀 전분의 색도는 원료 전분에 비하여 명도가 감소하였으며, 적색도 및 황색도는 증가하였다. 이것은 초산 처리 쌀 전분보다는 색상에서 좋지 않게 평가되었다. 인산 처리한 추청벼 및 삼강벼 전분의 호화개시 온도는 각각 5$0^{\circ}C$, 53$^{\circ}C$로서 인산 처리에 의해 원료 쌀 전분보다 14~15$^{\circ}C$ 낮아졌으며, 인산 쌀전분의 점도는 원료 쌀 전분에 비하여 7.4~8.4배 증가하였고 추청벼 전분이 삼강벼 전분보다 높게 나타났다. 인산 쌀 전분 겔의 견고성, 응집성, 접착성, 탄력성, 점착성 및 씹힘성은 원료 전분 겔보다 높았으며 두 품종간에는 추청벼 전분이 다소 높았다. 인산 쌀 전분 입자의 표면 구조는 원료 쌀 전분에 비하여 다소 팽윤되어 헝클어진 형태를 나타냈다. 이상의 결과를 볼 때 인산 처리 쌀전분이 원료 쌀 전분보다 호하 개시 온도가 낮고, 점도가 높아 즉석면의 제조 시 호화 온도를 낮추고 쫄깃쫄깃한 촉감의 면을 만들 수 있음을 시사하고 있으며, 정이 보고한 초산 처리 쌀 전분과 이용성을 비교할 때 인산 처리 전분이 라면 제조에 있어 더 효과적일 것임이 예상된다.desirability(전체적으로 바람직한 정도)의 경우 효소처리시킨 시료중 pH6.5$\longrightarrow$3.5, 35$^{\circ}C$(T1)과 45$^{\circ}C$(T3)처리군이 28일간 수침시켜 제조한 유과와 비교될 만한 높은 점수를 보여 이를 처리군에서 바람직한 특성을 지닌 유과 제조가 가능한 것으로 나타났다.의 Softness 는 Compression force 및 Work ratio 와 유의적인 상관관계를 나타내었으며, Dryness 와 Crumblyness 는 Work ratio와 유의적인 상관관계를 나타내고 있어 백편의 조직감은 Compression force 와 Work ratio로 대치할 수 있을 것이라고 사료된다. 수분함량은 기계적 검사보다 관능검사와 더욱 높은 상관관계를 나타냈다.내었다. 항균활성이 우수한 생약재를 농도별로 활성을 조사한 결과, 물 추출물과 10% Ethanol 추출물 모두 낮은 농도에서도 우수한 항균활성을 나타내었다.취와 함께 점질성 갈변물질이 생성되었다. 이와 같은 결과로 볼 때, BAAG의 처리는 BAAC의 경우보다 가격은 저렴하면서도 항균력은 우수한 천연 항균복합제재로써 농산물 식품원료에 적용하여 선도유지 기간을 연장할 수 있는 효과를 기대할 수 있었다. 과일 등의 포장제로서 이용할 가능성을 확인하였다.로 [-wh] 겹의문사는 복수 의미를 지닐 수 없 다. 그러면 단수 의미는 어떻게 생성되는가\ulcorner 본 논문에서는 표면적 형태에도 불구하고 [-wh]의미의 겹의문사는 병렬적 관계의 합성어가 아니라 내부구조를 지니지 않은 단순한 단어(minimal $X^{0}$ elements)로 가정한다. 즉, [+wh] 의미의 겹의문사는 동일한 구성요

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Stress-strain Relations of Concrete Confined with Tubes Having Varying GFRP Layers (수적층 및 필라멘트 와인딩을 이용한 GFRP튜브로 구속된 콘크리트의 압축 거동)

  • Lee, Sung Woo;Choi, Sokhwan
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.6A
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    • pp.861-872
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    • 2008
  • Concrete-filled glass fiber reinforced polymer tubes are often used for marine structures with the benefit of good durability and high resistance against corrosion under severe chemical environment. Current research presents results of a comprehensive experimental investigation on the behavior of axially loaded circular concrete-filled glass fiber reinforced polymer tubes. This paper is intended to examine several aspects related to the usage of glass fiber fabrics and filament wound layers used for outer shell of piles subjected to axial compression. The objectives of the study are as follows: (1) to evaluate the effectiveness of filament winding angle of glass fiber layers (2) to evaluate the effect of number of GFRP layers on the ultimate load and ductility of confined concrete (3) to evaluate the effect of loading condition of specimens on the effectiveness of confinement and failure characteristics as well, and (4) to propose a analytical model which describes the stress-strain behavior of the confined concrete. Three different types of glass fiber layers were chosen; fabric layer, ${\pm}45^{\circ}$ filament winding layer, and ${\pm}85^{\circ}$ filament winding layer. They were put together or used independently in the fabrication of tubes. Specimens that have various L:D ratios and different diameters have also been tested. Totally 27 GFRP tube specimens to investigate the tension capacity, and 66 concrete-filled GFRP tube specimens for compression test were prepared and tested. The behavior of the specimens in the axial and transverse directions, failure types were investigated. Analytical model and parameters were suggested to describe the stress-strain behavior of concrete under confinement.

The Role of Postoperative Magnetic Resonance Imaging of Microvascular Decompression of the Facial Nerve in Patients with Hemifacial Spasm (반측성 안면경련증 환자에서 안면신경의 미세혈관감압술 후에 시행한 자기공명영상의 역할)

  • Han, In Bo;Chang, Jong Hee;Chang, Jin Woo;Park, Yong Gou;Kim, Dong Ik;Chung, Sang Sup
    • Journal of Korean Neurosurgical Society
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    • v.30 no.sup1
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    • pp.44-50
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    • 2001
  • Objectives : The objective of this study was to investigate the role of postoperative three dimensional short-range magnetic resonance angiography(3D-TOF MRA) in predicting the clinical outcomes following microvascular decompression(MVD) for the treatment of a hemifacial spasm(HFS). Material and Method : Postoperative magnetic resonance(MR) imaging was performed on 123 patients with a HFS between March 1999 and May 2000. All patients who had postoperative MR imaging were undertaken preoperative MR imaging. Of the 123 patients, 122 patients were included in this retrospective study. The degree of the detachment of vascular contact, and change of the position of offender were determined by pre- and postoperative 3D-TOF MRA. These findings were compared with the surgical findings and clinical outcomes. Results : Of 122 patients who had successful MVD, clear decompression of offenders of the root entry zone(REZ) of facial nerve was found in 106 patients(86.9%), partial decompression in 10 patients(8.2%) and contact of offenders to the REZ of facial nerve in 6 patients(4.9%) by the postoperative 3D-TOF MRA. Our patients demonstrated that the types of offender did not influence with the degree of decompression of REZ of facial nerve and with surgical outcomes(p>0.05). Also, there was no significant relationship between the degree of decompression of the REZ of facial nerve from offenders and an improvement of symptoms(p>0.05). Futhermore, there was no significant relationship between the degree of decompression of the REZ of facial nerve from offenders and an improvement time (p>0.05). Conclusion : Our data suggests that MVD of facial nerve alone may not be sufficient to resolve the symptoms in all patients with hemifacial spasm. Therefore, another unknown factors besides vascular compression may be involved to cause symptoms in certain patients and it may be necessary to remove these factors with MVD simultaneously to obtain the resolution of symptom.

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Development of Uniform Press for Wafer Bonder (웨이퍼 본딩 장비용 Uniform Press 개발)

  • Lee, Chang-Woo;Ha, Tae-Ho;Lee, Jae-Hak;Kim, Seung-Man;Kim, Yong-Jin;Kim, Dong-Hoon
    • Transactions of the KSME C: Technology and Education
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    • v.3 no.4
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    • pp.265-271
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    • 2015
  • The bonding process should be achieved in vacuum environment to avoid air bubble. In this study, we studied about pressure uniformity that became an issue in thermo compression bonding usually. Uniform press is realized by the method that use air spring and metal form spring. The concept of uniform press using air spring is removed except pressing direction in the press processing so angle between the vector of pressure surface and the pressure axis is parallel automatically. Air spring compensate the errors of machining and assembly. Metal form compensate the thermal deformation and flatness error.