• 제목/요약/키워드: Acceptable limits

검색결과 234건 처리시간 0.024초

전기제품 에너지 소비효율의 통계적 양산 관리 방법에 대한 연구 (A Study on the Statistical Production Control of Energy Efficiency in Electric Product)

  • 전영호;김성돈
    • 한국경영공학회지
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    • 제23권4호
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    • pp.73-86
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    • 2018
  • Most electric products produced during the manufacturing process are produced after design and mass production under a given control standard. In particular, the development phase should present the criteria for the production process by setting appropriate limits based on the performance being targeted. Even if the standard of performance is set considering the performance of the process, measuring the performance of the product after actual production results will cause nonconformities with the expected results. Among the performance of electrical products, Energy standards represented by energy consumption efficiency continue to be of importance, and are mandatory standards that correspond to national standards in most countries. Therefore, statistical quality control of these standards shall basically have a large number of test equipment for each product, ensure sufficient test time and continuous sampling of product samples. In the end, companies that produce and sell electric appliances are striving to control mass production at a great cost, but this is not acceptable. This study presents basic characteristics of the energy efficiency of electrical products and proposes and conducts a case study on statistical production control methods for performance variation across products under the standards about domestic and international regulations.

종자류 식품에 함유된 5종 리그난의 동시 분석법 개발 (Development of Simultaneous Analytical Method for Five Lignans in Edible Seeds)

  • 김윤정;편지예;백인환;김영화
    • 한국식품영양학회지
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    • 제35권6호
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    • pp.543-551
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    • 2022
  • There has been increased interest in lignans due to their potential effect in reducing the risk of developing several diseases. To evaluate lignan contents, sensitive and accurate methods should be developed for their quantification in food. The present study aimed to validate a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of 5 lignans: lariciresinol (Lar), matairesinol (Mat), pinoresinol (Pin), secoisolariciresinol (Seco), and syringaresinol (Syr). The validation included selectivity, linearity, recovery, accuracy, and precision. The method was proved to be specific, with a linear response (R2≥0.99). The limits of detection were 0.040~0.765 ㎍/100 g and the limits of quantification were 0.114~1.532 ㎍/100 g. Recoveries were 90.588~109.053% for black sesame powder. Relative standard deviations of repeatability and reproducibility were below 5%. Total lignan contents of roasted coffee bean, oat, and blacksoy bean were 105.702 ㎍/100 g, 78.965 ㎍/100 g, and 165.521 ㎍/100 g, respectively. These results showed that LC-MS/MS analysis would be effective in producing acceptable sensitivity, accuracy, and precision in five lignan analyses.

만성 뇌졸중 환자들의 Step Test의 상대적·절대적 신뢰도와 타당도 (The Relative·Absolute Reliability and Validity of Step Test in Patients with Chronic Stroke)

  • 이병권;최현수;안승헌
    • 대한통합의학회지
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    • 제5권1호
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    • pp.43-53
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    • 2017
  • Purpose : To examine the relative absolute reliability and validity of step test (ST) scores in subjects with chronic stroke. Method : A total of 27 stroke patients, participated in the study. A relative reliability index (intraclass correlation coefficient, ICC) was used to examine the level of agreement of inter-rater test-retest reliability for ST score. Absolute reliability indices, including the standard error of measurement(SEM) and the minimal detectable change (MDC), and limits of agreement by Bland and Altman analysis. The validity was demonstrated by spearman correlation of ST score with 10 m Walk Test (10mWT), Fugl-Meyer Assessment-Lower/Extremity (FMA-L/E)-total score, Berg Balance Scale (BBS)-total score. Result : An excellent inter-rater reliability in ST scores was found (paretic, ICC=0.993~0.996; nonparetic, ICC=0.982~0.991). In addition, excellent test-retest reliability was found (paretic, ICC=0.992; nonparetic, ICC=0.967). It all showed acceptable SEM of the ST score as paretic and nonparetic were 0.22 and 0.46 respectively (average score <10 %), and the MDC of the paretic and nonparetic were 0.61 and 1.27 respectively (possible highest score <20 %). indicating that measures had a small and acceptable measurement error. The ST score of paretic and nonparetic were also found to be significantly associated with 10MWT (r=0.77~0.79), FMA-LE scores (r=0.73~0.81) and BBS scores (r=0.72~0.76). Conclusion : The ST showed highly sufficient Inter-rater test-retest agreement and validity and acceptable measurement errors caused by due to chance variation in measurement. It also can be used by clinicians and researchers to assess the balance and mobility performance and monitor functional change in chronic stroke patients.

Permitted Daily Exposure for Diisopropyl Ether as a Residual Solvent in Pharmaceuticals

  • Romanelli, Luca;Evandri, Maria Grazia
    • Toxicological Research
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    • 제34권2호
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    • pp.111-125
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    • 2018
  • Solvents can be used in the manufacture of medicinal products provided their residual levels in the final product comply with the acceptable limits based on safety data. At worldwide level, these limits are set by the "Guideline Q3C (R6) on impurities: guideline for residual solvents" issued by the ICH. Diisopropyl ether (DIPE) is a widely used solvent but the possibility of using it in the pharmaceutical manufacture is uncertain because the ICH Q3C guideline includes it in the group of solvents for which "no adequate toxicological data on which to base a Permitted Daily Exposure (PDE) was found". We performed a risk assessment of DIPE based on available toxicological data, after carefully assessing their reliability using the Klimisch score approach. We found sufficiently reliable studies investigating subchronic, developmental, neurological toxicity and carcinogenicity in rats and genotoxicity in vitro. Recent studies also investigated a wide array of toxic effects of gasoline/DIPE mixtures as compared to gasoline alone, thus allowing identifying the effects of DIPE itself. These data allowed a comprehensive toxicological evaluation of DIPE. The main target organs of DIPE toxicity were liver and kidney. DIPE was not teratogen and had no genotoxic effects, either in vitro or in vivo. However, it appeared to increase the number of malignant tumors in rats. Therefore, DIPE could be considered as a non-genotoxic animal carcinogen and a PDE of 0.98 mg/day was calculated based on the lowest No Observed Effect Level (NOEL) value of $356mg/m^3$ (corresponding to 49 mg/kg/day) for maternal toxicity in developmental rat toxicity study. In a worst-case scenario, using an exceedingly high daily dose of 10 g/day, allowed DIPE concentration in pharmaceutical substances would be 98 ppm, which is in the range of concentration limits for ICH Q3C guideline class 2 solvents. This result might be considered for regulatory decisions.

Verification of a computer-aided replica technique for evaluating prosthesis adaptation using statistical agreement analysis

  • Mai, Hang-Nga;Lee, Kyeong Eun;Lee, Kyu-Bok;Jeong, Seung-Mi;Lee, Seok-Jae;Lee, Cheong-Hee;An, Seo-Young;Lee, Du-Hyeong
    • The Journal of Advanced Prosthodontics
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    • 제9권5호
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    • pp.358-363
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    • 2017
  • PURPOSE. The purpose of this study was to evaluate the reliability of computer-aided replica technique (CART) by calculating its agreement with the replica technique (RT), using statistical agreement analysis. MATERIALS AND METHODS. A prepared metal die and a metal crown were fabricated. The gap between the restoration and abutment was replicated using silicone indicator paste (n = 25). Gap measurements differed in the control (RT) and experimental (CART) groups. In the RT group, the silicone replica was manually sectioned, and the marginal and occlusal gaps were measured using a microscope. In the CART group, the gap was digitized using optical scanning and image superimposition, and the gaps were measured using a software program. The agreement between the measurement techniques was evaluated by using the 95% Bland-Altman limits of agreement and concordance correlation coefficients (CCC). The least acceptable CCC was 0.90. RESULTS. The RT and CART groups showed linear association, with a strong positive correlation in gap measurements, but without significant differences. The 95% limits of agreement between the paired gap measurements were 3.84% and 7.08% of the mean. The lower 95% confidence limits of CCC were 0.9676 and 0.9188 for the marginal and occlusal gap measurements, respectively, and the values were greater than the allowed limit. CONCLUSION. The CART is a reliable digital approach for evaluating the fit accuracy of fixed dental prostheses.

A proton induced X-ray emission (PIXE) analysis of concentration of major/trace and toxic elements in broiler gizzard and flesh of Tehsil Gujar Khan area in Pakistan

  • Nadeem, Khawar;Hussain, Javaid;Haq, Noaman Ul;Haq, A. Ul;Akram, Waheed;Ahmad, Ishaq
    • Nuclear Engineering and Technology
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    • 제51권8호
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    • pp.2042-2049
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    • 2019
  • Ten gizzard and three flesh samples of the broiler were collected from different locations in Tehsil Gujar Khan District Rawalpindi, Pakistan. The samples were dried, crushed and ground. Pellets were prepared by pressing the powder of the samples and that of the Bovine liver 1577c reference material obtained from NIST, USA. Proton induced X-ray emission (PIXE) installed at National Center for Physics, Islamabad, Pakistan has been used as a reliable and improved technique to determine concentration of various major/trace and toxic elements e.g. S, Cl, K, Ca, Cl, Fe, Cu, Mn, Co, Zn, Ti, Cd, Ga, Cr, V and Ni, in the Gizzard and Flesh samples of the broiler. The concentrations of all the detected elements in the samples are statistically significant. The certified and measured values of the elements in the reference material were in agreement with each other within a deviation of 7%. S, Cl, K and Ca are within tolerable limits and are good for human consumption. Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn were more than the acceptable limits of World Health Organization, WHO whereas Ga, As, Sn, Sb and Pb are not detected in most of the samples.

SEVERE ACCIDENT MANAGEMENT CONCEPT OF THE VVER-1000 AND THE JUSTIFICATION OF CORIUM RETENTION IN A CRUCIBLE-TYPE CORE CATCHER

  • Khabensky, Vladimir Benzianovich;Granovsky, Vladimir Semenovich;Bechta, Sevostian Victorovich;Gusarov, Victor Vlasmirovich
    • Nuclear Engineering and Technology
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    • 제41권5호
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    • pp.561-574
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    • 2009
  • First ex-vessel core catcher has been applied to the practical design of NPPs with VVER-1000 reactors built in China (Tyanvan) and India (Kudankulam) for severe accident management (SAM) and mitigation of SA consequences. The paper presents the concept and basic design of this crucible-type core catcher as well as an evaluation of its efficiency. The important role of oxidic sacrificial material is discussed. Insight into the behaviour of the molten pool, which forms in the catcher after core relocation from the reactor vessel, is provided. It is shown that heat loads on the water-cooled vessel walls are kept within acceptable limits and that the necessary margins for departure from nucleate boiling (DNB) and of vessel failure caused by thermo-mechanical stress are satisfactorily provided for.

신경회로망과 수학적 방정식을 이용한 최적의 용입깊이 예측에 관한 연구 (A Study on Prediction of Optimized Penetration Using the Neural Network and Empirical models)

  • 전광석
    • 한국생산제조학회지
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    • 제8권5호
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    • pp.70-75
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    • 1999
  • Adaptive control in the robotic GMA(Gas Metal Arc) welding is employed to monitor the information about weld characteristics and process paramters as well as modification of those parameters to hold weld quality within the acceptable limits. Typical characteristics are the bead geometry composition micrrostructure appearance and process parameters which govern the quality of the final weld. The main objectives of this paper are to realize the mapping characteristicso f penetration through the learning. After learning the neural network can predict the pene-traition desired from the learning mapping characteristic. The design parameters of the neural network estimator(the number of hidden layers and the number of nodes in a layer) were chosen from an error analysis. partial-penetration single-pass bead-on-plate welds were fabricated in 12mm mild steel plates in order to verify the performance of the neural network estimator. The experimental results show that the proposed neural network estimator can predict the penetration with reasonable accuracy and gurarantee the uniform weld quality.

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로봇 GMA용접에 최적의 비드폭 예측 시스템 개발에 관한 연구 (A Study on Development of System for Prediction of the Optimal Bead Width on Robotic GMA Welding)

  • 김일수
    • 한국생산제조학회지
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    • 제7권6호
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    • pp.57-63
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    • 1998
  • An adaptive control in the robotic GMA welding is employed to monitor information about weld characteristics and process parameters as well as to modify those parameters to hold weld quality within acceptable limits. Typical characteristics are the bead geometry, composition, microstructure, appearance, and process parameters which govern the quality of the final weld. The main objectives of this thesis are to realize the mapping characteristics of bead width through learning. After learning, the neural estimation can estimate the bead width desired form the learning mapping characteristic. The design parameters of the neural network estimator(the number of hidden layers and the number of nodes in a layer) are chosen from an estimation error analysis. A series of bead of bead-on-plate GMA welding experiments was carried out in order to verify the performance of the neural network estimator. The experimental results show that the proposed neural network estimator can predict the bead width with reasonable accuracy and guarantee the uniform weld quality.

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칡잎 색소의 특성과 염색성에 관한 연구 (Characteristics and Dyeing Properties of Arrowroot Leaves Colors)

  • 조경래
    • 한국의류학회지
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    • 제15권3호
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    • pp.281-288
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    • 1991
  • Optical behaviors and dyeing properties of color solution extracted from arrowroot leaves were investigated. The wavelength of maximum absorption of the color solution appeared at 268 and 320 nm, respectively. The amount of colors extracted was increased with extracting temperature and time. Spectra of color solution are shifted to longer wavelength at higher pH values, and shifted to shorter wavelength by irradiation for 2 hrs. Remaining ratio of colors by irradiation decreased with increasing alkalinity of color solution. Degree of exhaustion on the silk fabrics was related to the concentration and pH of dyebath. Surface color of dyed fabrics, lightfastness and wash-fastness were variously according to mordant used. Hot water resistance and drycleaning fastness of dyed silk fabrics by treatment of mordants were all within commercially acceptable limits.

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