• Title/Summary/Keyword: shortening effect

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Design Sensitivity Studies for Statistical Energy Analysis Modeling of Construction Vehicle Cab (통계적 에너지 해석 모델을 이용한 건설 장비 차실 설계에 관한 연구)

  • 채장범
    • Journal of KSNVE
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    • v.8 no.4
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    • pp.609-615
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    • 1998
  • In recent years there has been an increasing emphasis on shortening design cycles for bringing products to market. This requires the development of computer aided engineering tools which allow analysts to quickly evaluate the effect of design changes on noise, vibration, and harshness. Statistical Energy Analysis (SEA) modeling is a valuable tool for predicting noise and vibration as SEA models are inherently simpler and more robust than deterministic models. SEA modeling can be combined with design sensitivity analysis(DSA) to identify design changes which give the largest performance benefit. This paper describes SEA modeling of an equipment cab. SEA predictions are compared to test data, showing good agreement. The use of design sensitivity analysis in improving cab design is then demonstrated.

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Fast-Curing of Phenol·Formaldehyde Resin Adhesives for Plywood (합판용 페놀수지 접착제의 속경화)

  • Roh, Jeang-Kwan
    • Journal of the Korean Wood Science and Technology
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    • v.23 no.3
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    • pp.33-39
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    • 1995
  • To accelerate the cure of phenolic resin adhesives for plywood, the complexation with melamine resin and the addition of cure-accelerating agents were discussed. The hot-pressing temperature and time of phenol resin could be decreased by complexation with melamine resin. but the wet glue-joints strength of phenol melamine resin was lower than that of ordinary phenol resin in case of plywood using spruce veneer at core layer. Among the tested cure-accelerating agents. the sodium carbonate showed the greatest effect on shortening gelation time of phenolic resin. In addition, in the manufacturing scale test, the hot-pressing time of phenol resin with the addition of 5 parts sodium carbonate could be shortened about 20% compared with ordinary phenol resin which had same glue-joints properties.

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Amputation in Diabetic Foot Ulcer and Infection (당뇨병성 족부 궤양 및 감염에서의 절단)

  • Han, Seung Hwan;Park, Young Chang
    • Journal of Korean Foot and Ankle Society
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    • v.18 no.1
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    • pp.8-13
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    • 2014
  • Amputation of diabetic foot ulcer and infection is a critical modality for saving a patient's life from life threatening infections or ischemic limbs. However, it can cause serious handicaps or complications, such as lifetime shortening and re-amputation of the other limb. The minimal amputation is the main goal of amputation in diabetic patients. However, insufficient amputation can have a harmful effect on patients. The decision of amputation is very difficult and should be made using multidisciplinary approaches. All aspects of the patient's situation, including vascular status, degree of infection, and medical conditions should be considered. The foot surgeon should keep in mind the notion that proper amputation can lead to a new life for diabetic foot patients.

Mechanical Loads Analysis and Control of a MW Wind Turbine (MW 규모 풍력 터빈의 기계적 하중 특성 해석 및 제어)

  • Nam, Yoon-Su;Choi, Han-Soon
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.9
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    • pp.26-33
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    • 2010
  • A multi-MW wind turbine is a huge mechanical structure, of which the rotor diameter is more or less than 100 m. Rotor blades experience unsymmetric mechanical loads caused by the interaction of incoming wind with the tower and wind shear effect. These mechanical loads are transferred to the entire structure of the wind turbine and are known as the major reasons for shortening the life span of the wind turbine. Therefore, as the size of wind turbine gets bigger, the mitigation of mechanical loads becomes more important issue in wind turbine control system design. In this paper, a concept of an individual pitch control(IPC), which minimizes the mechanical loads of rotor blades, is introduced, and simulation results using IPC are discussed.

A New Fiber Processing Method

  • Seo, Yung-Bum;Lee, Chun-Han
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2006.06b
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    • pp.433-440
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    • 2006
  • A fiber processing method, which might be an alternative for conventional refining process, was introduced. The method consists of repetitive, gentle, mechanical impacts on fiber, and ensued fiber uncurling process. This method was very effective for OCC and BCTMP for increasing WRVs (water retention value) while keeping fiber lengths from shortening. For OCC and BCTMP, gentle mechanical impacts on fibers using Hobart mixer increased breaking lengths and tear strengths simultaneously at fast drainage level, and straightening fibers using kady mill increased those strength properties further. For SwBKP and HwBKP, only mechanical impacts using the mixer were effective on increasing tensile and tear strength at fast drainage, but not kady mill treatment. The strength increases of BCTMP by this alternative fiber processing method were exceptionally high. An extensive engineering development should be followed to actualize this fiber processing mechanism in an energy-effect way.

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A structure of musculotendon model with a fatigue profile of electrically stimulated skeletal muscle (전기자극이 가해진 골격근의 피로항을 갖는 근육 모델의 구조)

  • Lim, Jong-Kwang;Nam, Moon-Hyon
    • Proceedings of the KIEE Conference
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    • 1998.07b
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    • pp.611-613
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    • 1998
  • A structure of musculotendon model with a fatigue profile is investigated. The Hill-type musculotendon model can predicts the decline in muscle force for a given fatigue profile. It consists of nonlinear activation and contraction dynamics based on the physiological concepts. It is normalized for generalization to deal with the various muscles. Muscle force generated by continuous tetanic electrical monophasic pulsewidth modulation stimulation is decreased in time. A fatigue profile is expressed by a function of intramuscular acidification and applied to the relationship between muscle force and shortening velocity in contraction dynamics. The results of computer simulation are well matched with data in a literature which are isometrically performed for knee extension muscles. Also change in optimal fiber length has an effect only on muscle time, constant not on the steady-state tetanic force.

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Numerical Studies on the S-Shaped Duct Flow for Compressors (압축기용 S형 덕트 유동에 대한 수치해석적 연구)

  • Choi, Chang-Ho;Noh, Jun-Gu;Kim, Jin-Han
    • The KSFM Journal of Fluid Machinery
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    • v.7 no.4 s.25
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    • pp.40-46
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    • 2004
  • This paper is concerned with the numerical analyses of an S-shaped duct for the inter-channel between compressor spools. For the compactness and lightweight of an engine, the length of the S-shaped duct is desired to be minimized. Shortening the S-shaped duct, however, flow separation is likely to occur. Numerical investigation using a three-dimensional Navier-Stokes flow solver was performed to determine the availability of the minimization of an S-shaped duct. Computations were performed introducing the experimental data as the inlet flow condition of the OGV in determining the minimum length of the S-shaped duct. Also, the leaning effect of the OGV which assists the flow to turn radially inward was studied adopting mixing-plane method to consider the rotor/OGV interaction.

Effect of Ginseng Saponin Fraction on Cleavage of pBR322 by Several Restriction Endonuclease (인삼 Saponin분획이 제한효소에 의한 pBR322 절단에 미치는 영향)

  • 강정훈;조영동
    • Journal of Ginseng Research
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    • v.9 no.2
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    • pp.240-247
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    • 1985
  • Attempts were made to see if we could cut more pBR322 in the presence of ginseng saponin fraction in connection with possibly for shortening the enzymatic reaction time and the amount of the enzyme to be used. The following results were obtained restriction endonucleases such as AccI, XhoII, SaII, and HincII were observed to cut pBR322 efficiently at 10-1% ginseng saponin fraction. In case of BamHI, 10-2% ginseng saponin fraction was observed to the most effective concentration. Such cumulative results suggest that ginseng saponin fraction would play important role as far as the cleavage of pBR322 for short period by endonucleases is concerned.

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Load-Settlement Characteristics of Drilled Shafts Reinforced by Rockbolts (락볼트로 보강된 심형기초의 하중-침하 분석)

  • 윤경식;이대수;정상섬
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.10a
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    • pp.366-373
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    • 2002
  • This paper describes the load distribution and settlement of rockbolted-drilled shafts subjected to axial and lateral loads with the view to shortening the embedded depth of the pile shaft. The emphasis was on quantifying the reinforcing effects of rockbolts placed from the shafts to surrounding weathered rocks based on small-scale model tests peformed on instrumented piles. The major influencing parameters on reinforcing drilled shaft behavior are the number, the positions on the shaft, the grade, and the inclination angle at which the rockbolts are placed. The model tests was 1/40 scaled simulations of the behavior of the drilled shafts with varying combinations of the major influencing parameters. The incremental effects of reinforcement based on the various parameters have been weighed against load transfer characteristics before and after rockbolt installations.

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Opened Slab Based on Top-Down Method (개방형 슬래브를 이용한 지하 역타공법)

  • Jeon, Keum-Seok;Goh, Soo-Jin;Yom, Kyong-Soo;Rhim, Hong-Chul;Choi, Lin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2006.11a
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    • pp.9-12
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    • 2006
  • In recent years, construction site has developed lots of new methods and materials for Time-Cost Trade-off and improving constructability. In the case of underground construction, especially, there are many restrictions and difficulties. Shortening of the construction time in construction of underground, we use top-down method in undergroud wall. A open slab has been designed for the purpose of overcoming a weak point of former top-down method. This study based on open slab on the under ground top-down method, to more improve constructability, to introduce the effect and the performance of top-down method.

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