• Title/Summary/Keyword: overrun

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Influence of sugar alcohol and enzyme treatment on the quality characteristics of soy ice cream (당알콜과 효소의 종류가 대두아이스크림의 품질특성에 미치는 영향)

  • 구선희;이숙영
    • Korean journal of food and cookery science
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    • v.16 no.2
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    • pp.151-159
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    • 2000
  • The effects of bromelain and $\alpha$-chymotrypsin treatments on the functional properties(foaming capacity, foaming stability, emulsifying capacity, and emulsifying stability) of soy protein isolate(SPI) and the addition of various sweeteners(sucrose, sorbitol, xylitol) on the quality attributes(viscosity, overrun ratio, melt-down property, and sensory characteristic) of soy ice cream were studied. SPI was more effectively hydrolyzed with $\alpha$-chymotrypsin than bromelain, resulting in a better foaming and emulsifying capacity. Adding xylitol could significantly improve the viscosity, overrun and melt-down property of soy ice creams while the effect was the lowest in the sucrose addition. Bromelain treatment caused a lower apparent viscosity of SPI suspension compared with $\alpha$-chymotrypsin treatment and untreated. The overrun ratios of the soy ice cream prepared with bromelain and $\alpha$-chymotrypsin treated SPI were 18.9∼25.9% and 24.9∼40.3%, respectively as a result of freezing with agitation for 20 min in an ice cream maker. Comparatively, untreated SPI could bring only 15.8∼21.4% overrun ratios after operating for 15 min. The bromelain treatment caused high melt-down tendency of the product while soy ice cream with untreated SPI showed an opposite trend. In sensory characteristics, no significant differences in the strength of beany flavor were noted among the samples. Sweetness, bitter taste, icy feel, and mouthfeel of the product were greatly affected by the enzyme-treatment of SPI. Soy ice cream added with xylitol after $\alpha$-chymotrypsin treatment was the most acceptable among all samples.

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Effect of Inadequate Design on Cost and Time Overrun of Road Construction Projects in Tanzania

  • Rwakarehe, Eradius E.;Mfinanga, David A.
    • Journal of Construction Engineering and Project Management
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    • v.4 no.1
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    • pp.15-28
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    • 2014
  • Completing road construction projects within the budget and time has been a problem for the Tanzania National Roads Agency (TANROADS); and the major problem highlighted in almost all projects being inadequate design. However, the extent to which inadequate design contributes to both time and cost overruns and its causes remained under-studied. The objective of this study is therefore to determine the extent of the effect of inadequate design, its causes and remedial measures. The methodology used in this study includes reviewing recent projects completion reports, holding roundtable discussions with consultants and TANROADS officials and analyzing the information. Cost and time overruns for the reviewed projects averaged 44% and 26% respectively. Similarly, the extents to which inadequate design contributes to cost and time overruns were on average found to be 61% and 85% respectively. The overruns are predominantly related to problems that occurred during the design process. To alleviate the problem, TANROADS is advised to improve the management of design projects, enhance the process of reviewing design reports, improve the design process including introducing Road Safety Audit and geometric design manuals, and increase staff to match the work-load.

An Upshift Improvement in the Quality of Forklift's Automatic Transmission by Learning Control (학습제어를 이용한 지게차 자동변속기 상향 변속품질 개선)

  • Jung, Gyuhong
    • Journal of Drive and Control
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    • v.19 no.2
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    • pp.17-26
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    • 2022
  • Recently, automatic transmissions caused a good improvement in the shift quality of a forklift. An advanced shift control algorithm, which was based on TCU firmware, was applied with embedded control technology and microcontrollers. In the clutch-to-clutch shifting, one friction element is released and the other friction element is activated. During this process, if the release and application timings are not synchronized, an overrun or tie-up occurs and ultimately leads to a shift shock. The TCU, which measures only the speed of the forklift, inevitably applies the open-loop shift control. In this situation, the speed ratio does not change during the clutch fill. The torque phase occurs until the clutch is disengaged. In this study, an offline shift logic of the learning control was proposed. It induced a synchronous shift when the learning control progressed. During this process, the reference current trajectory of the release clutch was corrected and applied to the next upshift. We considered the results of the overrun/tie-up characteristics of the upshift performed immediately before. The vehicle test proved that the deviation in shift quality, which was caused by the difference in the mechanical characteristics of the clutch, could be improved by the learning control.

A Comparative Analysis of Risk Impacts on Cost Overrun between Actual Cases and Managers' Perception on Overseas Construction Projects (해외 프로젝트 시공단계 리스크 요인의 실제 비용 초과 영향과 현장관리자 인식 차이 분석)

  • Lee, Kyung-Tae;Ann, Hannah;Kim, Jae-Won;Kim, Ju-Hyung
    • Korean Journal of Construction Engineering and Management
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    • v.22 no.3
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    • pp.52-60
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    • 2021
  • Due to the significant size of overseas construction projects, the cost overrun has enormous impacts on the financial status of construction companies. The managers' appropriate perception and identification of key risk factors in the construction phase notably affect the performance of projects. However, the actual impacts of risk factors and local manager' s perception of them could be deviated. For this reason, we aim to compare the performance of actual cases and general opinions of responsible practitioners in terms of risk factors relevant to cost overruns in order to present a practical strategy for risk management. Firstly, factors classified from literature review were used to simulate 290 cost overruns data sets from 20 cases by introducing Monte-Carlo Simulation and were ranked by standardized coefficients through multiple regression analysis. Secondly, a survey was conducted against 42 local managers to rank their perception of impact on cost overrun with identical factors by using Stepwise Weight Assessment Ratio Analysis (SWARA). Comparison results show that conflicts such as 'conflict with subcontractors' and 'conflict with the local community' have caused excessive cost overrun. However, managers' perception of these as less significant than the actual influences and consider other risks such as 'material price fluctuation' and 'construction quality errors', as relatively serious. Therefore, education for local managers on conflict risks needs to be presented.

Effects of Bifidobacteria and oligosaccharides on the quality attributes of frozen soy yogurts (비피더스균과 올리고당이 frozen soy yogurt의 품질특성에 미치는 영향)

  • 권영실;이숙영
    • Korean journal of food and cookery science
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    • v.18 no.1
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    • pp.43-50
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    • 2002
  • This study was carried out to evaluate the quality attributes of frozen soy yogurts prepared by freezine soy yogurts, which are made of different types of Bifidobacteria (B. bifidum, B.breve, B. infantis) and oligosaccharides (fructooligosaccharides, galactooligosaccharides, isomaltooligosaccharides) containing $\alpha$-chymotrypsin treated soy protein isolate were evaluated in terms of overrun, melt-down quality, changes in the total number of Bifidobacteria after freezing, and sensory evaluation. The quality attributes of soy yogurts were also evaluated in terms of changes in the number of viable cells of Bifidobacteria in soy yogurts after incubation at 37$\^{C}$, pH 3.0 for 90 min, water holding capacity, and viscosity. The overrun of frozen soy yogurts fermented by B. bifidum showed the hiehest value but those fermented by B. infantis showed the lowest, while the melt-down quality of soy yogurts were vice versa. The total numbers of Bifidobacteria after freezing for 30 min in ice cream maker showed more than 10$\^$9/ CFU/ml. In sensory evaluation, all $\alpha$-chymotrypsin treated frozen soy yogsurt showed little beany flavor. In sour, sweet, and bitter tastes and mouth feel, the frozen soy yogurts fermented by B. bifidum evaluated better but those fermented by B. infantis evaluated worse. Also in the overall quality, the frozen soy yogurts fermented by B. bifidum were evaluated desirable but those fermented by B. infantis were evaluated undesirable. The water holding capacity and viscosity of soy yogurts fermented by B. bifidum showed the highest values but those fermented by B. infantis showed the lowest values. The total numbers of Bifidobacteria of all soy yogurts decreased from 10$\^$9/ CFU/ml to 10$\^$8/ CFU/ml after incubation at 37$\^{C}$, pH 3.0 for 90 min.

Requirements analysis for production of freeform concrete segments. (비정형 콘크리트 부재 생산을 위한 요구조건 분석)

  • Sung, Soojin;Lee, Donghoon;Kim, Sunkuk
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.05a
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    • pp.68-69
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    • 2014
  • Production of freeform concrete segments use various molds because of the unique shape of it unlike common concrete segments. As a result, the mold for freeform concrete segments cannot be reused. Therefor, cost overrun is occurred by needs of more time and manpower to produce the freeform concrete segments compared with common concrete segments. To prevent the cost overrun, a new production method for the freeform concrete segments is needed to develop and the requirements for it should be analyzed before. Therefor, the aim of this study is requirements analysis for production of freeform concrete segment. The requirements of production of freeform concrete segments and form for it is analyzed in this study. The result of this study would be used to suggest the new production method of freeform concrete segments.

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An Analysis on Relations between Design Errors Detected during BIM-based Design Validation and the Impacts Using Logistic Regression (로지스틱 회귀분석을 이용한 BIM 설계 검토에 의하여 발견된 설계 오류와 그 영향도간의 관계 분석)

  • Won, Jongsung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.05a
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    • pp.264-265
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    • 2017
  • This paper aims to analyze relations between design errors prevented by building information modeling (BIM)-based design validation and their impacts in order to identify critical consideration factors for successfully implementing BIM-based design validation in the architecture, engineering, and construction (AEC) projects. More than 800 design errors detected by BIM-based design validation in two BIM-based projects in South Korea are categorized according to its causes and work types. The relations between causes and work types of design errors and project delay, cost overrun, low quality, and rework generation that can be caused by the errors are analyzed through conducting logistic regression. Characteristics of each design error are analyzed by conducting face-to-face interviews with practitioners in the two BIM-based projects. As the results, the impacts of design error causes on predicting project delay, cost overrun, low quality, and rework generation were the highest.

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Quality Characteristics of Soy Ice Creams as Affected by Enzyme Hydrolysis Times and Added Calciums (효소처리시간과 칼슘의 종류를 달리한 칼슘강화 콩아이스크림의 품질특성)

  • 김지영;이숙영
    • Korean journal of food and cookery science
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    • v.19 no.2
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    • pp.216-222
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    • 2003
  • The effects of hydrolysis times and calcium source additions (calcium lactate, calcium carbonate), on the qualify characteristics of soy ice cream prepared with soy protein isolate(SPI), were studied. Increasing the hydrolysis time decreased the viscosity and overrun of soy ice creams, but increased the melt-down property. The addition of calcium lactate increased the viscosity of the soy ice cream mix, but no changes were observed from the calcium carbonate addition. The overrun of calcium lactate samples was higher than on addition of calcium carbonate. The addition of calcium lactate and calcium carbonate resulted in decreased melt-down properties, although these effects were more evident in the calcium lactate samples. However, calcium carbonate addition resulted in higher scores in the overall quality of the soy ice creams. In conclusion, better soy ice cream could be prepared by treating the SPI with Flavorzyme for 50 min, along with calcium fortification in the form of calcium carbonate.

Effects of irradiation on the physical and functional characteristics of egg whites (방사선 조사 난백의 물리적, 기능적 특성)

  • 이경애;최윤정
    • Korean Journal of Human Ecology
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    • v.4 no.1
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    • pp.62-67
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    • 2001
  • Effects of irradiation on the physical and functional characteristics of egg whites were investigated. Fresh shell eggs were irradiated at 0, 0.5, 1.0, 2.0 and 3.0kGy. Egg whites were separated from eggs kept at 3$0^{\circ}C$ for 2hr. There was a considerable decrease in viscosity of egg whites with irradiation. Irradiation made egg whites darker and less greenish. The foaming properties including foaming ability and stability were examined. Irradiation led to increase in whipping power and decrease in drainage in an irradiation dose-dependent manner. These results showed that irradiated egg whites had good foaming ability and stability.

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Effect of starch nanoparticle on the quality characteristics of whipped cream (전분 나노입자 첨가가 휘핑크림 품질특성에 미치는 영향)

  • Shin, Hye-Young;Choi, Hee-Don;Hong, Jung Sun;Shin, Kyeong Won;Kim, Jong-Yea
    • Korean Journal of Food Science and Technology
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    • v.52 no.4
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    • pp.423-426
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    • 2020
  • This study was performed to investigate how the addition of starch nanoparticles prior to whipping could affect the quality characteristics and stability of full-fat dairy cream. Starch nanoparticles were prepared by dry heating under mildly acidic conditions and added to dairy cream as amount of 1, 3, and 5% (w/w). The whipped cream's storage stability, viscosity, overrun, and droplet size were investigated in combination with various starch nanoparticle contents. The storage stability and apparent viscosity increased in parallel with the increasing starch nanoparticle content compared to the control. The mean size and homogeneity of the droplets in the whipped cream increased with higher starch nanoparticle addition levels. Even though the whipped cream overrun was reduced by the addition of starch nanoparticles, the 1% addition level exhibited a similar overrun value as the control.