• Title/Summary/Keyword: Rapidity

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Prediction of compressive strength of concrete using multiple regression model

  • Chore, H.S.;Shelke, N.L.
    • Structural Engineering and Mechanics
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    • v.45 no.6
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    • pp.837-851
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    • 2013
  • In construction industry, strength is a primary criterion in selecting a concrete for a particular application. The concrete used for construction gains strength over a long period of time after pouring the concrete. The characteristic strength of concrete is defined as the compressive strength of a sample that has been aged for 28 days. Neither waiting for 28 days for such a test would serve the rapidity of construction, nor would neglecting it serve the quality control process on concrete in large construction sites. Therefore, rapid and reliable prediction of the strength of concrete would be of great significance. On this backdrop, the method is proposed to establish a predictive relationship between properties and proportions of ingredients of concrete, compaction factor, weight of concrete cubes and strength of concrete whereby the strength of concrete can be predicted at early age. Multiple regression analysis was carried out for predicting the compressive strength of concrete containing Portland Pozolana cement using statistical analysis for the concrete data obtained from the experimental work done in this study. The multiple linear regression models yielded fairly good correlation coefficient for the prediction of compressive strength for 7, 28 and 40 days curing. The results indicate that the proposed regression models are effectively capable of evaluating the compressive strength of the concrete containing Portaland Pozolana Cement. The derived formulas are very simple, straightforward and provide an effective analysis tool accessible to practicing engineers.

Development of a Product Specification Based Quotation Management System for Customer-Oriented Manufacturing Enterprise (고객지향 수주생산 기업을 위한 제품사양 기반의 견적관리시스템 구축)

  • Jung, Soon-Il;Kim, Jae-Gyun;Jang, Gil-Sang
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.30 no.4
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    • pp.141-154
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    • 2007
  • Nowadays, customer-oriented manufacturing enterprises such as airplane, ship, ship engine, etc are knowledge-intensive and higher added value industries. In these companies, to quickly respond customer's order, a quotation management is a very important task. But, this task is very complex, time-consuming, resource- consuming, and difficult process because it is related with many departments within a company. In this paper, for the effective and efficient quotation management, the concept of product specification framework is introduced because a quotation BOM (bills of material) can be created from product specification. Also, this paper presents the product specification framework based quotation management process and implements the quotation management system for the ship engine division of 'H' company, one of customer-oriented manufacturing enterprises. As a result, the proposed quotation management concept reduced a lead time of drawing out quotations from $3{\sim}10$ days to 1 hour. And, the constructed quotation management system achieved a rapidity, accuracy, quality, and workload reduction of the quotation management process.

Studies on the Polarographic Behavior of Elemental Sulfur (원소 유황의 Polarograph 거동에 관한 연구)

  • 김준용;장순자
    • YAKHAK HOEJI
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    • v.22 no.4
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    • pp.201-206
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    • 1978
  • The analysis of elemental sulfur by polarography has already been reported in the literature. Only a discussion of the more important factors influencing the analysis is here presented. (1) The effects of pH on the reduction of elemental sulfur are pronounced and the use of buffered solutions for the analysis of elemental sulfur is necessary. The authors found that a pH of 4-6 was found to be reproducible polarograms by use of D.C. polarograph. However, in alkali solvents the plateau of elemental sulfur has a pronounced dip if the concentration of sulfur is as much as 30ppm. (2) A.C. polarographic method shows a very high sensitivity in the case of sulfur reduction, so that the very low concentration of sulfur can easily be determined (about 1ppm). (3) The characteristics of sulfur wave can be formulated according to Stackelberg-Hauck-Hans equation. It was found that the curve of the peak potential of elemental sulfur in A.C. polarography versus logarithm of sulfur concentration was obtained to be straight line with the slope of 29.6 millivolts. This result was well agreed with theoretical consideration. (4) It was assumed that this polarographical methods were applicable to micro-analysis of elemental sulfur in crude oil and its petrochemical products, precipitated sulfur, and sulfur ointments with accuracy and rapidity.

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Optimized Ballast Water Exchange Management for Bulk Carriers (벌크 화물선용 자동 밸러스트수 교환계획 시스템 개발)

  • HONG CHUNG-YOU;PARK JE-WOONG
    • Journal of Ocean Engineering and Technology
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    • v.18 no.4 s.59
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    • pp.65-70
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    • 2004
  • Many port states, such as New Zealand, U.S.A., Australia, and Canada, have strict regulations to prevent arriving ships from discharging polluted ballast water that contains harmful aquatic organisms and pathogens. They are notified that transfer of polluted ballast water can cause serious injury to public health and damage to property and environment. For this reason, ballast exchange in deep sea is perceived as the most effective method of emptying ballast water. The ballast management plan contains the effective exchange method, ballast system, and safety considerations. In this study, we pursued both nautical engineering analysis and optimization of the algorithm, in order to generate the sequence of stability and rapidity. A heuristic algorithm was chosen on the basis of optimality and applicability to a sequential exchange problem. We have built an optimized algorithm for the automatic exchange of ballast water, by redefining core elements of the A$\ast$ algorithm, such as node, operator, and evaluation function. The final version of the optimized algorithm has been applied to existing bulk carrier, and the performance of the algorithm has been successfully verified.

Biosensor System for the Detection and Assessment of Safety in Milk and Dairy Products (우유 및 유제품의 안전성 평가를 위한 바이오센서의 이용)

  • Kim, Hyoun-Wook;Han, Sang-Ha;Ham, Jun-Sang;Seol, Kuk-Hwan;Jang, Ae-Ra;Kim, Dong-Hun;Oh, Mi-Hwa
    • Journal of Dairy Science and Biotechnology
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    • v.29 no.2
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    • pp.51-57
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    • 2011
  • Milk and dairy products are nutritionally one of the most important food in human health and the quality of raw milk is significantly important to ensure safety of dairy products. However, milk and dairy products are commonly related with chemical and microbial contaminations. Therefore, rapid and reliable detection of hazardous (e.g. pathogenic bacteria, pesticides, antibiotics, microbial toxins) in milk and dairy products is essential to ensure human health and food safety. Conventional methods for detection of food hazardous are mostly time-consuming to yield a results. Recently, biosensors have been focused as its rapidity and high sensitivity to analyse chemical and microbial hazardous from a variety of foods and environments. This study reviewed the recent trends and applications of biosensors as rapid detection method of hazardous in milk and dairy products.

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A Study on the Penetration Fracture Strength of Fragile Plates subjected to High Speed Impact (고속 충격을 받는 취성재 평판의 관통파괴 강도)

  • 김지훈;심재기;양인영
    • Journal of the Korean Society of Safety
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    • v.11 no.4
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    • pp.3-9
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    • 1996
  • In this study, comparison of theoretical solutions with experimental results is examined through fracture conditions for the case of float glasses subjected static loading. The range of fracture generation limits and critical penetration energies are solved according to the impactor mass under the high velocity, and analytical method of fracture strength and penetration strength are presented. Also, fracture patterns are investigated according to impact velocities. The results obtained from this study are as follows ; 1) Radial cracks are generated from the loading point regardless of plate thickness in the case of the plate subjected to the static loading. In the case of high-speed impact, dimensions of ring cracks become to smaller and length of radial cracks becomes shorter with the rapidity of impact velocity. 2) Kinetic change volume of collision after/before is constant regardless of velocities over the range of critical penetration velocity. 3) Although the same impact energy is working, the critical penetration energy is increased with the shorter of impactor mass. 4) Although the same impact energy is working, the penetration fracture of lighter Impactor mass is generated more than that of heavier impactor mass, and the impulse of lighter impacter mass appear more than that of heavier impactor mass. Therefore, the penetration fracture in the case of greater impulse is generated earlier regardless of the of the dimensions of Impact loading.

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An Improved Variable Step Size MPPT Algorithm Based on INC

  • Xu, Zhi-Rong;Yang, Ping;Zhou, Dong-Bao;Li, Peng;Lei, Jin-Yong;Chen, Yuan-Rui
    • Journal of Power Electronics
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    • v.15 no.2
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    • pp.487-496
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    • 2015
  • In order to ensure that photovoltaic (PV) systems work at the maximum power point (MPP) and maximize the economic benefits, maximum power point tracking (MPPT) techniques are normally applied to these systems. One of the most widely applied MPPT methods is the incremental conductance (INC) method. However, the choice of the step size still remains controversial. This paper presents an improved variable step size INC MPPT algorithm that uses four different step sizes. This method has the advantages of INC but with the ability to validly adjust the step size to adapt to changes of the PV's power curve. The presented algorithm also simultaneously achieves increased rapidity and accuracy when compared with the conventional fixed step size INC MPPT algorithm. In addition, the theoretical derivation and specific applications of the proposed algorithm are presented here. This method is validated by simulation and experimental results.

Functional Neuroimaging in Epilepsy: FDG-PET and SPECT (간질에서의 기능적 뇌영상:양전자방출단층촬영과 단일광전자방출 단층촬영)

  • Lee, Sang-Kun;Lee, Dong-Soo
    • The Korean Journal of Nuclear Medicine
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    • v.37 no.1
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    • pp.24-33
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    • 2003
  • Finding epileptogenic zone is the most important step for the successful epilepsy surgery. F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and single photon emission computed tomography (SPECT) can be used in the localization of epileptogenic foci. In medial temporal lobe epilepsy, the diagnostic sensitivity of FDG-PET and ictal SPECT is excellent. However, detection of hippocampal sclerosis by MRI is so certain that use of FDG-PET and ictal SPECT in medial temporal lobe epilepsy is limited for some occasions. In neocortical epilepsy, the sensitivities of FDG-PET or ictal SPECT are fair. However, FDG-PET and ictal SPECT can have a crucial role in the localization of epileptogenic foci for non-lesional neocortical epilepsy. Interpretation of FDG-PET has been recently advanced by voxel-based analysis and automatic volume of interest analysis based on a population template. Both analytical methods can aid the objective diagnosis of epileptogenic foci. Ictal SPECT was analyzed using subtraction methods and voxel-based analysis. Rapidity of injection of tracers, ictal EEG findings during injection of tracer, and repeated ictal SPECT were important technical issues of ictal SPECT. SPECT can also be used in the evaluation of validity of Wada test.

"To Invent the Truth": Ford Madox Ford's Life and His Literary Impression ("진실의 창안": 포드 매독스 포드의 삶과 문학적 인상주의)

  • Kim, Heesun
    • English & American cultural studies
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    • v.14 no.2
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    • pp.127-157
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    • 2014
  • Among many literary isms, impressionism is often regarded as the most frank expression of personality. As a masterpiece of modernism, Ford Madox Ford's The Good Soldier is a celebration of the subjectivity which reflects the writer's experiential reality. For Madox Ford, art is not to achieve the true objectivity of human society, but to seize the momentary perception in personal life. As the beginning of modernism, Madox Ford's impressionaism was mostly devoted to give fictive life to subjective impressions. And his heroes are usually the egoless person who can absorb the intense rapidity of consciousness without any prejudice. However, the innocent mind's receptions of myriad impressions, like those of the protagonist John Dowell or his idealized version of Major Ashburnham in The Good Solidier, were described as the enjoyable yet deceptive ones in Madox Ford's works. To engrave more sold perceptive impressions into life, Madox Ford often contrasts or mixes truth with deception, life with death as he did in his real life. Speicially as the result of thick application of real-life subject matters to his writings, Madox Ford's literary works get more vivid colors and penetrating forms. Thus, his literary impressionism based upon his harsh and passionate realities overcomes the limitations of shifting moments of senses, demolishing the boundaries between what is objective and what is subjective, like post-impressionism or expressionism. Namely, as Walter Lowenfels said, Madox Ford did not follow the impossible objectivity passively, yet instead "knew how to invent the truth."

Rapid and sensitive detection of Salmonella species targeting the hilA gene using a loop-mediated isothermal amplification assay

  • Chu, Jiyon;Shin, Juyoun;Kang, Shinseok;Shin, Sun;Chung, Yeun-Jun
    • Genomics & Informatics
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    • v.19 no.3
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    • pp.30.1-30.8
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    • 2021
  • Salmonella species are among the major pathogens that cause foodborne illness outbreaks. In this study, we aimed to develop a loop-mediated isothermal amplification (LAMP) assay for the rapid and sensitive detection of Salmonella species. We designed LAMP primers targeting the hilA gene as a universal marker of Salmonella species. A total of seven Salmonella species strains and 11 non-Salmonella pathogen strains from eight different genera were used in this study. All Salmonella strains showed positive amplification signals with the Salmonella LAMP assay; however, there was no non-specific amplification signal for the non-Salmonella strains. The detection limit was 100 femtograms (20 copies per reaction), which was ~1,000 times more sensitive than the detection limits of the conventional polymerase chain reaction (PCR) assay (100 pg). The reaction time for a positive amplification signal was less than 20 minutes, which was less than one-third the time taken while using conventional PCR. In conclusion, our Salmonella LAMP assay accurately detected Salmonella species with a higher degree of sensitivity and greater rapidity than the conventional PCR assay, and it may be suitable for point-of-care testing in the field.