• Title/Summary/Keyword: Standard variation

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Development of Phantom and Comparison Analysis for Performance Characteristics of MOSFET Dosimeter (MOSFET 선량계 특성분석을 위한 팬톰 개발 및 특성 비교)

  • Chung, Jin-Beom;Lee, Jeong-Woo;Kim, Yon-Lae;Lee, Doo-Hyun;Choi, Kyoung-Sik;Kim, Jae-Sung;Kim, In-Ah;Hong, Se-Mie;Suh, Tae-Suk
    • Progress in Medical Physics
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    • v.18 no.1
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    • pp.48-54
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    • 2007
  • This study is to develope a phantom for MOSFET (Metal Oxide Semiconductors Field Effect Transistors) dosimetry and compare the dosimetric properties of standard MOSFET and microMOSFET with the phantom. In this study, the developed phantom have two shape: one is the shape of semi-sphere with 10cm diameters and the other one is the flat slab of $30{\times}30cm$with 1 cm thickness. The slab phantom was used for calibration and characterization measurements of reproducibility, linearity and dose rate dependency. The semi-sphere phantom was used for angular and directional dependence on the types of MOSFETs. The measurements were conducted under $10{\times}10cm^2$ fields at 100cm SSD with 6MV photon of Clinac (21EX, Varian, USA). For calibration and reproducibility, five standard MOSFETS and microMOSFETs were repeatedly Irradiated by 200cGy five times. The average calibration factor was a range of $1.09{\pm}0.01{\sim}1.12{\pm}0.02mV/cGy$ for standard MOSFETS and $2.81{\pm}0.03{\sim}2.85{\pm}0.04 mV/cGy$ for microMOSFETs. The response of reproducibility in the two types of MOSFETS was found to be maximum 2% variation. Dose linearity was evaluated In the range of 5 to 600 cGy and showed good linear response with $R^2$ value of 0.997 and 0.999. The dose rate dependence of standard MOSFET and microMOSFET was within 1% for 200 cGy from 100 to 500MU/min. For linearity, reproducibility and calibration factor, two types of MOSFETS showed similar results. On the other hand, the standard MOSFET and microMOSFET were found to be remarkable difference in angular and directional dependence. The measured angular dependence of standard MOSFET and microMOSFET was also found to be the variation of 13%, 10% and standard deviation of ${\pm}4.4%,\;{\pm}2.1%$. The directional dependence was found to be the variation of 5%, 2% and standard deviation of ${\pm}2.1%,\;{\pm}1.5%$. Therefore, dose verification of radiation therapy used multidirectional X-ray beam treatments allows for better the use of microMOSFET which has a reduced angular and directional dependence than that of standard MOSFET.

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A Study on the Water Quality Patterns of Unit Watersheds for the Management of TMDLs - in Nakdong River Basin - (수질오염총량관리 단위유역 수질변화 유형분석 - 낙동강수계를 대상으로 -)

  • Park, Jun Dae;Kim, Jin Lee;Rhew, Doug Hee;Jung, Dong Il
    • Journal of Korean Society on Water Environment
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    • v.26 no.2
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    • pp.279-288
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    • 2010
  • The water quality variations or changes are closely relevant to the characteristics of unit watersheds and have an effect on the attainment of their water quality goal. This study was conducted to analyze the water quality distribution and its change patterns of unit watersheds in Nakdong river basin. It revealed that 25 unit watersheds out of 41 showed the normality in water quality. Most of unit watersheds had a considerable variation in water quality, especially in the season of spring and summer but a little in terms of flow rate. Annual relative differences in water quality ranged from 13.0 to 26.6% with the maximum of 75%. 28 unit watersheds (62%) had the tendency to decrease in water quality as the flow rate increased while 13 (38%) to increase. The extension of standard flow led to considerable differences in water quality depending on its ranges, which meant uncertainties might be included in the process of TMDL development. It is suggested that annual average flow rate should be chosen as a standard flow in the area where the water quality change has little relation to the flow rate.

A Study on the Integrated Computer Program for the Multi Analysis of In-Situ Aquifer and Geothermal Response Test (현장 열응답시험과 현장 대수성시험결과를 동시 분석 가능한 통합전산 Program에 관한 연구)

  • Hahn, Jeong-Sang;Han, Hyuk-Sang;Yonn, Yun-Sang
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.4 no.1
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    • pp.11-19
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    • 2008
  • Groundwater flow in confined aquifer and heat transport in underground geologic media are using same governing equation(line source) like well fuction. Therefore the conventional slope method using only later data obtained from in-situ thermal response test to determine the thermal conductivity of vertical geothermal heat exchanger(GHEX) is basically identical with one of Theis straight line method of aquifer test under artesian condition. In case that the pumping rate(Q, $m^3$/d) and drawdown(s,m) which are used for input data of existing hydrogeologic computer programs for aquifer test are replaced and converted to supplying heat energy per unit length of bore hole(Q/L,w/m or Kcal/h.m) and temperatures (T,$^{\circ}C$)measured at in and out-let of GHEX as in put data respectively, thermal conductivity around geothermal heat exchanger can be easily estimated without any special modification of the existing hydrogeologic computer program. Two numbers of time series temperature variation data obtained from in situ geothermal response test are analized using Theismethods(standard curve and straight line method) by using existing aquifer test program and conventional Slope method proposed by ASHRAE. The results show that thermal conductivity values estimated by two straight methods are identical and the difference of estimated values between standard curve methods and Slope method are also within acceptable ranges. In general,the thermal conductivity estimated from Theis straight linemethod gives more accurate value than the one of Slope method due to that Slope method uses only visual matching otherwise Theis method uses automatic curve matching estimation with reducing RSS.

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An Application Study of Six Sigma in Clinical Chemistry (6 시그마의 적용에 대한 연구)

  • Chang, Sang Wu;Kim, Nam Yong;Choi, Ho Sung;Park, Yong Won;Chu, Kyung Bok;Yun, Kyeun Young
    • Korean Journal of Clinical Laboratory Science
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    • v.36 no.2
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    • pp.121-126
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    • 2004
  • The primary goal of six sigma is to improve patient satisfaction, and thereby profitability, by reducing and eliminating defects. Defects may be related to any aspect of customer satisfaction: high product quality, schedule adherence, cost minimization, process capability indices, defects per unit, and yield. Many six sigma metrics can be mathematically related to the others. Literally, six means six standard deviations from the mean or median value. As applied to quality metrics, the term indicates that failures are at least six standard deviations from the mean or norm. This would mean about 3.4 failures per million opportunities for failure. The objective of six sigma quality is to reduce process output variation so that on a long term basis, which is the customer's aggregate experience with our process over time, this will result in no more than 3.4 defect Parts Per Million(PPM) opportunities (or 3.4 Defects Per Million Opportunities. For a process with only one specification limit (upper or lower), this results in six process standard deviations between the mean of the process and the customer's specification limit (hence, 6 Sigma). The results of applicative six sigma experiment studied on 18 items TP, ALB, T.B, ALP, AST, ALT, CL, CK, LD, K, Na, CRE, BUN, T.C, GLU, AML, CA tests in clinical chemistry were follows. Assessment of process performance fits within six sigma tolerance limits were TP, ALB, T.B, ALP, AST, ALT, CL, CK, LD, K, Na, CRE, BUN, T.C, GLU, AML, CA with 72.2%, items that fit within five sigma limits were total bilirubin, chloride and sodium were 3 sigma. We were sure that the goal of six sigma would reduce test variation in the process.

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Identification of Novel Standard Compounds for Standardization of Sinbaro3 Pharmacopuncture (신바로3 약침의 표준화를 위한 지표물질 검색)

  • Lee, Jin-Ho;Lee, Jae-Woong;Kim, Min-Jeong;Kim, Eun-Jee;Lee, In-Hee
    • Journal of Korean Medicine Rehabilitation
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    • v.25 no.2
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    • pp.65-72
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    • 2015
  • Objectives To investigate and validate potential standard compounds for standardization of Sinbaro3 pharmacopuncture prepared at OO Hospital of Korean Medicine. Methods Sinbaro3 pharmacopuncture was prepared by extraction, purification and hydrolysis of Harpagophytum procumbens, and various potential standard compounds were quantified through HPLC-UV and HPLC-MS analysis. Validation was examined by assessing specificity, linearity, precision, and accuracy. Results The retention time of harpagide and cinnamic acid were 15.2 min and 28.2 min, respectively, and both showed good linearity in analysis by concentration at 0.9999 and 0.9998, respectively. Intra-day variation of precision was 0.0015~0.0045% and 0.0058~0.1629%, while inter-day variation of precision was 0.0011~0.0243% and 0.0098~0.1629%, and that of accuracy was 99.53~99.89% and 99.50~99.91%, respectively. Conclusions Harpagide and cinnamic acid, which are hydrolyzates of harpagoside within Sinbaro3 pharmacopuncture, were both validated using HPLC-MS and HPLC-UV analysis, and Sinbaro3 pharmacopuncture contained 78.41 ug/ml harpagide, and 2.05 ug/ml cinnamic acid.

Modelling Stem Diameter Variability in Pinus caribaea (Morelet) Plantations in South West Nigeria

  • Adesoye, Peter Oluremi
    • Journal of Forest and Environmental Science
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    • v.32 no.3
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    • pp.280-290
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    • 2016
  • Stem diameter variability is an essential inventory result that provides useful information in forest management decisions. Little has been done to explore the modelling potentials of standard deviation (SDD) and coefficient of variation (CVD) of diameter at breast height (dbh). This study, therefore, was aimed at developing and testing models for predicting SDD and CVD in stands of Pinus caribaea Morelet (pine) in south west Nigeria. Sixty temporary sample plots of size $20m{\times}20m$, ranging between 15 and 37 years were sampled, covering the entire range of pine in south west Nigeria. The dbh (cm), total and merchantable heights (m), number of stems and age of trees were measured within each plot. Basal area ($m^2$), site index (m), relative spacing and percentile positions of dbh at $24^{th}$, $63^{rd}$, $76^{th}$ and $93^{rd}$ (i.e. $P_{24}$, $P_{63}$, $P_{76}$ and $P_{93}$) were computed from measured variables for each plot. Linear mixed model (LMM) was used to test the effects of locations (fixed) and plots (random). Six candidate models (3 for SDD and 3 for CVD), using three categories of explanatory variables (i.e. (i) only stand size measures, (ii) distribution measures, and (iii) combination of i and ii). The best model was chosen based on smaller relative standard error (RSE), prediction residual sum of squares (PRESS), corrected Akaike Information Criterion ($AIC_c$) and larger coefficient of determination ($R^2$). The results of the LMM indicated that location and plot effects were not significant. The CVD and SDD models having only measures of percentiles (i.e. $P_{24}$ and $P_{93}$) as predictors produced better predictions than others. However, CVD model produced the overall best predictions, because of the lower RSE and stability in measuring variability across different stand developments. The results demonstrate the potentials of CVD in modelling stem diameter variability in relationship with percentiles variables.

A Study on the Serviceability of High-Tension Bolt Friction Joints according to Oversize Bolt Holes (과대 볼트구멍에 따른 고장력볼트 마찰이음의 사용성에 관한 연구)

  • Park, Jeong-Ung;Yang, Seung-Hyun;Cho, Kang-Kyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.8
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    • pp.2055-2061
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    • 2009
  • There can be some variation in the load carrying capacity of high-tension bolt friction joints when oversize bolt holes are made on the base plate and the cover plate. This study performed a static tensile test in order to examine the variation of slip load and slip coefficient according to standard bolt hole and oversize bolt hole in high-tension bolt friction joints. According to the results of the static tensile test, the slip coefficient changed to some degree according to oversize bolt holes on the base plate and the cover plate, but it was somewhat unreasonable to find a pattern in the change. Sliding strength showed a difference of up to 26% between the use of standard bolt holes and the use of oversize bolt holes. Because this exceeds the design sliding strength, however, its effect on the serviceability of joints under service load is insignificant. Thus, if the regulation on oversize bolt holes, which may be inevitable in making steel members, is applied flexibly, we may improve efficiency and economy in the design and construction of structures.

A Study on the Comparison and Characteristics of Public Standard Housing Unit Plan before and after the Independence from the Japan Occupation (광복전후(光復前後) 공영주택(公營住宅)의 평면비교(平面比較)와 변화특성(變化特性)에 관한 연구(硏究))

  • Yoo, Jae-Woo
    • Journal of architectural history
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    • v.11 no.2 s.30
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    • pp.23-35
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    • 2002
  • Even though there have been greate changes in the types and contents of the housing plan in Korea since the Modem age, it seems that the identity of traditional dwelling culture is still remains within it. The purpose of this study is to examine the characteristics and features in the development of the 'Public Standard' Housing Unit Plan by comparing the differences and similarities in unit plans in housings built on Japanese occupation period and those built after the period. From the study, we can conclude as follows: 1. The public standard housing unit plans on both periods have shown the common features in the composition of their physical forms in the way that the front-row area still remains the traditional housing culture and the rear-row area reflects the desires of the modem lives. The structure of the dual-row unit plan appeared in the public standard housing plan was caused by the cultural acculturation in Japanese occupation period. 2. The public standard housing unit plans, however, show the differences in the contents and meaning in units plans with the them of the Japanese housing because of the cultural differences. These differences took placed autonomously through the change of housing plans in the modern time, and have the common features such that 1) the changes in the Maru-centered plan type differ in composition from the inner-corridor plan type used Japanese housing, and 2) the composition of the open-inner spaces in the double-row housing plan reflects the single-row outer open space In the traditional housing. All of these cultural progresses in the public standard housing unit plans was took place as the result of the inner-oriented and notional circulations derived from the modernity. However, the transformed unit plans still contains the identity derived from the variation of the traditional Korean building elements such as Maru and Ondol. In other words, those are the Maru-centered and composed housing plans with juxtaposition of the inner block and the outer block. As the conclusion, though the public standard dwelling unit plan has the similarity in the physical form, it is different in the cultural Identity and meaning from the public standard plans before the independence from the Japan occupation.

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A Distcussion on the Size Deviation Test of Raw Silk (生絲纖度檢査規定에 關한 考察)

  • Choi, Jin-Sub
    • Journal of Sericultural and Entomological Science
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    • v.25 no.1
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    • pp.44-50
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    • 1983
  • The study was carried out to suggest on opinion of the standardization of size deviation in the existing raw silk testing method. 1. The present grade A of size deviation stipulates 4.61 to 5.80 of standard deviation for 50 to 69 denier of mean value, however, the 5.80 standard deviation with the mean values of 50 and 69 denier belong to different distribution. 2. It is reasonable that the variation coefficients of grade 2A should be lower than that of grade A. However, the present testing method shows larger variation in grade 2A than in grade A. This is illustrated 9.00 for 69 denier in grade 2A and 8.41 for 70 denier in grade A. 3. The size deviation value compares the quality of raw silk with different mean value. Therefore, the standard deviation is recommended to be replaced by the C.V. value in determining the grade of silk. 4. The C.V. have a tendency to increase with lower grades below 6A for the size deviation below 33 denier with some inconsistencies. The figures should be adjusted so that the C.V. inconsistencies size deviation below 33 denier will be corrected. 5. The standard deviation increases with size under the same grade for the size deviations above 33 denier, however, the C.V. does not vary greatly with size deviation. 6. To rectify the above-mentioned inconsistencies the C.V. conversion and curvilinear regresion correction is recommended to improve the present silk testing method 7. The table of size deviation standard are as follows: Suggested standard of size deviation, unit: C.V. Value

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Development of the Approximate Cost Estimating Model Using Statistical Inference for PSC Box Girder Bridge Constructed by the Incremental Launching Method (통계적 기법을 활용한 ILM압출공법 교량 상부공사 개략공사비 산정모델 개발 연구)

  • Kim, Sang-Bum;Cho, Ji-Hoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.2
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    • pp.781-790
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    • 2013
  • This research focuses on development of the conceptual cost estimation models for I.L.M box girder bridge. The current conceptual cost estimation for public construction projects is dependent on governmental average unit price references which has been regarded as inaccurate and unreliable by many experts. Therefore, there have been strong demands for developing a better way of conceptual cost estimating methods. This research has proposed three different conceptual cost estimating method for a P.S.C. girder bridge built with the I.L.M method. Model (I) attempts to seek the proper breakdown of standard works that are accountable for more than 95 percentage in total cost and calculates the amount of standard work's materials from the standard section and volume of I.L.M box girder bridge. Model (II) utilizes a correlation analysis (coefficient over 0.6 or more) between breakdown of standard works and input data that would be considered available information in preliminary design phase. Model(III) obtains conceptual estimating through multiple-regression analysis between the breakdown of standard works and all of input data related to them. In order to validate the clustering of coverage in the preliminary design phase, the variation of I.L.M cost coverage from multiple-regression analysis[model(III)] has been investigated which result in between -3.76% and 11.79%, comparing with AACE(Association for the Advancement of Cost Engineering) which informs its variation between -5% and +15% in the design phase. The model proposed from this research are envisioned to be improved to a great distinct if reliable cost date for P.S.C. girder bridges can be continually collected with reasonable accuracies.