• 제목/요약/키워드: Core Quality

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초음파법을 이용한 무근콘크리트 터널라이닝의 품질평가 (Evaluation of Tunnel Lining Concrete Using Ultrasonic Pulse Velocity Method)

  • 최홍식;이시우;신용석;오영석;오광진
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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    • pp.795-800
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    • 2001
  • Two evaluation techniques of the tunnel lining concrete using ultra sonic velocity method are developed. Modified linear regression technique is proposed to enhance the corelation between the pulse velocity and the compressive strength of core specimens. And bivariate normal distribution is assumed to evaluate the quality of concrete as a terms of compressive strength. A simple corelation table between the pulse velocity and the compressive strength of core specimens are proposed.

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창조적 문제해결 기법 : TRIZ/TIPS (Theory of Inventive Problem Solving : TRIZ/TIPS)

  • 박수동;박영택
    • 한국품질경영학회:학술대회논문집
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    • 한국품질경영학회 1998년도 The 12th Asia Quality Management Symposium* Total Quality Management for Restoring Competitiveness
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    • pp.531-543
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    • 1998
  • TRIZ, the Russian acronym for Theory of Inventive Problem Solving(TIPS) is introduced in this paper. The core concepts of TRIZ such as levels of inventions, patterns of technological evolution, technical and physical contradictions are explained. It is also discussed that how TRIZ can be applied to quality function deployment in order to overcome negative correlations(i.e., trade-off relationships) between engineering characteristics. Some case examples are presented for the purpose of explanation.

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우기중에 타설된 콘크리트의 품질 특성에 관한 연구 (A Study on the Quality of Concrete Place under Raining Condition)

  • 권영웅;정성철
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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    • pp.729-736
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    • 1997
  • This paper gives the information of field concrete placed under raining condition. Experimental factors in this study are concrete strength, standard deviation and coefficient of variation. The results are as follows: 1. The strength of field concrete placed under raining condition is not largely dependent on the raining condition. 2. But, the quality of concrete is very critical.

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러프셋 이론과 개체 관계 비교를 통한 의사결정나무 구성 (A New Decision Tree Algorithm Based on Rough Set and Entity Relationship)

  • 한상욱;김재련
    • 대한산업공학회지
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    • 제33권2호
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    • pp.183-190
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    • 2007
  • We present a new decision tree classification algorithm using rough set theory that can induce classification rules, the construction of which is based on core attributes and relationship between objects. Although decision trees have been widely used in machine learning and artificial intelligence, little research has focused on improving classification quality. We propose a new decision tree construction algorithm that can be simplified and provides an improved classification quality. We also compare the new algorithm with the ID3 algorithm in terms of the number of rules.

현장 타설용 콘크리트의 시공품질 검토를 위한 연구 (A Study on Construction Quality Inspection of Field use Concrete)

  • 김민석;강병훈;강태경;박선길;이종균;정상진
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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    • pp.1057-1062
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    • 2000
  • The purpose of this study is to practice the method which can estimate 28-days strength of concrete in advance. This method is made for reliant quality control. Based on existing experiment, concrete that flyash added and normal concrete are placed into wall structure, and it is examined the difference between experiment use concrete and field use concrete. The result of this study are as follows : 1) Core test specimen have 10% lower strength to standard curing specimen. 2) At 28-days accelerated strength by microwave, average 35% in normal concrete, average 23% in flyash added concrete. 3) At coefficient of determination between compressive strength and accelerated strength, 0.84 in normal concrete core, 0.86 in standard curing normal concrete, 0.86 in flyash added concrete, 0.90 in standard curing flyash added concrete.

차양막 직물용 코팅사 제조기술에 관한 연구 (Study on Manufacturing Technology of Coating Yarns for Awning Fabrics)

  • 김승진;이은호;허경;김현아
    • 한국염색가공학회지
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    • 제27권1호
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    • pp.35-49
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    • 2015
  • This paper investigated optimum process conditions of coating yarn for awning fabric. For this purpose, the simulation for processability and yarn quality using SPSS statistics package was carried out, and PP/TPO and PET/PVC coating yarns specimens were made with variation of extruder temperature and feed speed of core yarn on the yarn coating machine for examining simulation result. It was revealed that optimum coating conditions of PP/TPO 1000d coating yarn were extruder temperature $150^{\circ}C$, and core yarn feed speed 400~500m/min. Mechanical property and thermal shrinkage of PP/TPO coating yarn made at this conditions were best and core evenness rates of these coating yarns by yarn compression tester were also superior, which was certified by SEM photograph. In addition, these experimental results were coincided with simulation results. It was found that, in PET/PVC coating yarn, yarn physical properties between 1500d and 1200d coated yarns were not shown any difference, and core evenness rates of these coating yarns were superior. It revealed and concluded that these simulated coating conditions are applicable to production field.

대퇴골두 무혈성 괴사 감압술 시술 후 발생한 고관절 통증 환자의 치험 1례 (A Case Report on a Patient of Pain after Core Decompression Surgery on Avascular Necrosis of Femur Head Treated with Korean Medicine Treatments)

  • 조성우
    • 척추신경추나의학회지
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    • 제14권2호
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    • pp.55-65
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    • 2019
  • Objectives : The aim of this study was to report the improvements in pain that a woman experienced after receiving Korean medicine treatments for the pain associated with core decompression surgery due to avascular necrosis (AVN) of both femur heads. Methods : The patient was diagnosed as having AVN in both femur heads and underwent core decompression surgery. After operation, she had pain on her right inguinal region and her range of motion (ROM) was restricted. She was treated with Korean medicine including, herbal medicine, acupuncture, Chuna Manual Therapy and bee venom acupuncture (BV). This study was measured by using the Visual Analogue Scale (VAS) and the ROM scale. Results : After conservative treatment, the patient's pain was reduced and ROM was increased. Daily living quality had improved. Conclusions : In this case, Korean conservative medicine therapy with Chuna Manual Therapy had a positive effect on the symptoms after core decompression surgery due to avascular necrosis of the femur head.

Evaluation of Genetic Variability in Kenkatha Cattle by Microsatellite Markers

  • Pandey, A.K.;Sharma, Rekha;Singh, Yatender;Prakash, B.;Ahlawat, S.P.S.
    • Asian-Australasian Journal of Animal Sciences
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    • 제19권12호
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    • pp.1685-1690
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    • 2006
  • Kenkatha cattle, a draft purpose breed, which can survive in a harsh environment on low quality forage, was explored genetically exploiting FAO-suggested microsatellite markers. The microsatellite genotypes were derived by means of the polymerase chain reaction (PCR) followed by electrophoretic separation in agarose gels. The PCR amplicons were visualized by silver staining. The allelic as well as genotypic frequencies, heterozygosities and gene diversity were estimated using standard techniques. A total of 125 alleles was distinguished by the 21 microsatellite markers investigated. All the microsatellites were highly polymorphic with mean allelic number of 5.95${\pm}$1.9 (ranging from 3-10 per locus). The observed heterozygosity in the population ranged between 0.250 and 0.826 with a mean of 0.540${\pm}$0.171, signifying considerable genetic variation. Bottleneck was examined assuming all three mutation models which showed that the population has not experienced bottleneck in recent past. The population displayed a heterozygote deficit of 21.4%. The study suggests that the breed needs to be conserved by providing purebred animals in the breeding tract.

Interpretation of Physical Properties of Marine Sediments Using Multi­Sensor Core Logger (MSCL): Comparison with Discrete Samples

  • Kim, Gil-Young;Kim, Dae-Choul
    • Journal of the korean society of oceanography
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    • 제38권4호
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    • pp.166-172
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    • 2003
  • Multi­Sensor Core Logger (MSCL) is a useful system for logging the physical properties (compressional wave velocity, wet bulk density, fractional porosity, magnetic susceptibility and/or natural gamma radiation) of marine sediments through scanning of whole cores in a nondestructive fashion. But MSCL has a number of problems that can lead to spurious results depending on the various factors such as core slumping, gas expansion, mechanical stretching, and the thickness variation of core liner and sediment. For the verification of MSCL data, compressional wave velocity, wet bulk density, and porosity were measured on discrete samples by Hamilton Frame and Gravimetric method, respectively. Acoustic impedance was also calculated. Physical property data (velocity, wet bulk density, and impedance) logged by MSCL were slightly larger than those of discrete sample, and porosity is reverse. Average difference between MSCL and discrete sample at both sites is relatively small such as 22­24 m/s in velocity, $0.02­-0.08\;g/\textrm{cm}^3$ in wet bulk density, and 2.5­2.7% in porosity. The values also show systematic variation with sediment depth. A variety of factors are probably responsible for the differences including instrument error, various measurement method, sediment disturbance, and accuracy of calibration. Therefore, MSCL can be effectively used to collect physical property data with high resolution and quality, if the calibration is accurately completed.

On-line measurement and simulation of the in-core gamma energy deposition in the McMaster nuclear reactor

  • Alqahtani, Mohammed
    • Nuclear Engineering and Technology
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    • 제54권1호
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    • pp.30-35
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    • 2022
  • In a nuclear reactor, gamma radiation is the dominant energy deposition in non-fuel regions. Heat is generated upon gamma deposition and consequently affects the mechanical and thermal structure of the material. Therefore, the safety of samples should be carefully considered so that their integrity and quality can be retained. To evaluate relevant parameters, an in-core gamma thermometer (GT) was used to measure gamma heating (GH) throughout the operation of the McMaster nuclear reactor (MNR) at four irradiation sites. Additionally, a Monte Carlo reactor physics code (Serpent-2) was utilized to model the MNR with the GT located in the same irradiation sites used in the measurement to verify its predictions against measured GH. This research aids in the development of modeling, calculation, and prediction of the GH utilizing Serpent-2 as well as implementing a new GH measurement at the MNR core. After all uncertainties were quantified for both approaches, comparable GH profiles were observed between the measurements and calculations. In addition, the GH values found in the four sites represent a strong level of radiation based on the distance of the sample from the core. In this study, the maximum and minimum GH values were found at 0.32 ± 0.05 W/g and 0.15 ± 0.02 W/g, respectively, corresponding to 320 Sv/s and 150 Sv/s. These values are crucial to be considered whenever sample is planned to be irradiated inside the MNR core.