• 제목/요약/키워드: Scaling factors

검색결과 486건 처리시간 0.022초

Properties of Water Substitute Solid Phantoms for Electron Dosimetry

  • Saitoh, Hidetoshi;Tomaru, Teizo;Fujisaki, Tatsuya;Abe, Shinji;Myojoyama, Atsushi;Fukuda, Kenichi
    • 한국의학물리학회:학술대회논문집
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    • 한국의학물리학회 2002년도 Proceedings
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    • pp.255-259
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    • 2002
  • To reduce the uncertainty in the calibration of radiation beams, absorbed dose to water for high energy electrons is recommended as the standards and reference absorbed dose by AAPM Report no.51 and IAEA Technical Reports no.398. In these recommendations, water is, defined as the reference medium, however, the water substitute solid phantoms are discouraged. Nevertheless, when accurate chamber positioning in water is not possible, or when no waterproof chamber is available, their use is permitted at beam qualities R$\_$50/ < 4 g/cm$^2$ (E$\_$0/ < 10 MeV). For the electron dosimetry using solid phantom, a depth-scaling factor is used for the conversion of depth in solid phantoms to depth in water, and a fluence-scaling factor is used for the conversion of ionization chamber reading in plastic phantom to reading in water. In this work, the properties, especially depth-scaling factors c$\_$p1/ and fluence-scaling factors h$\_$pl/ of several commercially available water substitute solid phantoms were determined, and the electron dosimetry using these scaling method was evaluated. As a result, it is obviously that dose-distribution in solid phantom can be converted to appropriate dose-distribution in water by means of IAEA depth-scaling.

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일부 치과위생사의 요통경험 및 관련요인(II) (Low Back Pain and Related factors in Dental Hygienists)

  • 이승주;조명숙
    • The Journal of Korean Physical Therapy
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    • 제11권2호
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    • pp.123-130
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    • 1999
  • Objectives : This study was to investigate the experience rate and factors related with Low Back Pain(LBP). Methods : Questionnaires were completed by 236 dental hygienists in Taegu city and Kyungpook province in June 23-27, 1999. The solicited information was used to estimate odds ration and $95\%$ confidence intervals for the LBP related factors association. Results : The experience rate of LBP was $78\%$. The experience rate of LBP was significantly associated with scaling posture(odds ratio=2.228)(p=0.0371) and stress with dentist(odds ratio=2.767) (p=0.0136). Conclusions : Data from this study support a statistically significant association between LBP and some factors found in other research to increase the relation with LBP. Study findings may have implications for targeting at dental hygienists for scaling posture education or intervention program.

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발전소 용량변경에 따른 비용보정계수 (Cost Scaling Factor according to Power Plant Capacity Change)

  • 하각현;김성환
    • 에너지공학
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    • 제22권3호
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    • pp.283-286
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    • 2013
  • 전력사업자의 요청, 경제적인 요인 또는 기타 요인에 따라 기존 발전소의 설계개념 변경 없이 발전소의 전기출력을 증가 또는 감소시켜 발전소를 재설계하는 경우가 종종 있다. 이때 노심출력 및 전기출력을 변경시켜 재설계되는 발전소의 설비들의 가격을 예측할 경우, 시장에서 견적을 받을 환경이 아닐 경우에는 기존발전소 설비들의 가격에 비용보정계수(Cost Scaling Factor)를 적용하여 새로 설계되는 발전소 설비들에 비용들을 계산할 수 있다. 이에 미국의 DOE, EPRI, ABB, SWEC 기관들의 발전소 용량변경에 따른 비용보정계수를 검토하고, 그것을 국내 PWR 1000MWe, 1400MWe에 적용한 결과를 소개하고자 한다.

액상화 지반에 대한 1-g 모형실험과 원심모형실험의 비교 연구 (Comparison of 1-g and Centrifuge Model Tests on Liquefied Sand Grounds)

  • 김성렬;황재익;;김명모
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2006년도 학술발표회 논문집
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    • pp.97-104
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    • 2006
  • The centrifuge and 1-g shaking table tests were performed simultaneously to compare the dynamic behaviors of loose sands of same geotechnical properties. The prototype soils were 10 m thick liquefiable loose sands. The geometric scaling factors were 20 for 1-g and 40 for centrifuge tests. The excess pore pressure, surface settlement, and acceleration in the soil were measured at the same locations in the 1-g and centrifuge tests. The total excess pore pressure from development to dissipation was measured. In the centrifuge test, viscous fluid was used as the pore water to eliminate the time scaling difference between dynamic time and dissipation time. In the 1-g tests, the steady state concept was applied to determine the unit weight of the model soil, and two different time scaling factors were applied for the dynamic time and the dissipationtime. It is concluded that the 1-g tests can simulate the excess pore pressure of the prototype soil if the permeability of the model soil is small enough to prevent dissipation of excess pore pressure during shaking and the dissipation time scaling factor is properly determined.

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Intra-Oral Factors Influencing Halitosis in Young Women

  • Shon, Ho Sun;Kim, Kyoung Ok;Jung, Jae Kwan;Cha, Eun Jong;Lee, Su Ok;Kim, Kyung Ah
    • Osong Public Health and Research Perspectives
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    • 제9권6호
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    • pp.340-347
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    • 2018
  • Objectives: The aim of this research was to determine intra-oral factors that affect halitosis in young women. Methods: This study was performed between March 2014 to May 2014, and included 35 women in their 20s with good oral health. Correlation and logistic regression analyses were performed to investigate the change in halitosis immediately, and 1 hour after scaling. Results: In both oral gas (OG) and extraoral gas (EG) groups, halitosis was reduced after scaling compared to before scaling. The logistic regression analysis of oral state factors in OG showed that as oral fluid [odds ratio (OR) = 0.792, p = 0.045] and dental plaque (OR = 0.940, p = 0.016) decreased by 1 unit, the OR in the OG group decreased (> 50). In addition, as glucose levels in the oral cavity (OR = 1.245, p = 0.075) and tongue coating index (OR = 2.912, p = 0.064) increased by 1 unit, the OR in the OG group increased (> 50). Furthermore, in the EG group, as oral fluid (OR = 0.66, p = 0.01) and dental plaque (OR = 0.95, p = 0.04) decreased, the OR in the EG group decreased (> 50) significantly. Conclusion: To control halitosis, it is necessary to increase oral fluid and decrease the amount of tongue plaque. Furthermore, maintaining a healthy oral environment, aided by regular scaling and removal of dental plaque, may significantly control halitosis.

축척법에 의한 화약 폭풍과 분석 (Analysis of Blast Wave of Explosives by the Scaling Law)

  • 박정수;김성호;이근득;이재민
    • 한국군사과학기술학회지
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    • 제8권4호
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    • pp.120-129
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    • 2005
  • To analyze a blast effect of developed explosives, three different kinds of aluminized tastable explosives and melted cast explosive TNT were used. Conventional explosive TNT was used as a reference. Each tested explosive charge of 340mm diameter spherical type was initiated at the charge center with DXD-65(${\sim}750g$) booster and RP-87 EBW detonator. Thirteen piezo type pressure sensors were located at a range from 4 to 50m away from the charge. From the blast wave profiles, we calculated a peak blast pressure and impulse of the explosion. The calculated pressures and in pulses were converted to TNT Equivalent Weight(TEW) factor by the scaling ]aw method. The average TEW factors based on the blast pressure of TX-01, TX-02, TX-03, TX-04 were 1.298, 1.05, 1.266, 1.274 and the average TEW factors based on impulse were 1.504, 1.686, 1.640, 1.679. From the results, we concluded that TEW factors based on blast pressure and based on impulse of aluminized explosives were superior to TNT. This results are owing to the high contents of aluminum in formulations.

Design of Fuzzy PD+I Controller Based on PID Controller

  • Oh, Sea-June;Yoo, Heui-Han;Lee, Yun-Hyung;So, Myung-Ok
    • 한국항해항만학회지
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    • 제34권2호
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    • pp.117-122
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    • 2010
  • Since fuzzy controllers are nonlinear, it is more difficult to set the controller gains and to analyse the stability compared to conventional PID controllers. This paper proposes a fuzzy PD+I controller for tracking control which uses a linear fuzzy inference(product-sum-gravity) method based on a conventional linear PID controller. In this scheme the fuzzy PD+I controller works similar to the control performance as the linear PD plus I(PD+I) controller. Thus it is possible to analyse and design an fuzzy PD+I controller for given systems based on a linear fuzzy PD controller. The scaling factors tuning scheme, another topic of fuzzy controller design procedure, is also introduced in order to fine performance of the fuzzy PD+I controller. The scaling factors are adjusted by a real-coded genetic algorithm(RCGA) in off-line. The simulation results show the effectiveness of the proposed fuzzy PD+I controller for tracking control problems by comparing with the conventional PID controllers.

유전 알고리듬을 이용한 자동 동조 퍼지 제어기의 하이브리드 최적화 기법 (Hybrid Optimization Techniques Using Genetec Algorithms for Auto-Tuning Fuzzy Logic Controllers)

  • 유동완;이영석;박윤호;서보혁
    • 대한전기학회논문지:전력기술부문A
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    • 제48권1호
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    • pp.36-43
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    • 1999
  • This paper proposes a new hybrid genetic algorithm for auto-tuning fuzzy controllers improving the performance. In general, fuzzy controllers use pre-determined moderate membership functions, fuzzy rules, and scaling factors, by trial and error. The presented algorithm estimates automatically the optimal values of membership functions, fuzzy rules, and scaling factors for fuzzy controllers, using a hybrid genetic algorithm. The object of the proposed algorithm is to promote search efficiency by the hybrid optimization technique. The proposed hybrid genetic algorithm is based on both the standard genetic algorithm and a modified gradient method. If a maximum point is not be changed around an optimal value at the end of performance during given generation, the hybrid genetic algorithm searches for an optimal value using the the initial value which has maximum point by converting the genetic algorithms into the MGM(Modified Gradient Method) algorithms that reduced the number of variables. Using this algorithm is not only that the computing time is faster than genetic algorithm as reducing the number of variables, but also that can overcome the disadvantage of genetic algoritms. Simulation results verify the validity of the presented method.

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Stage-GAN with Semantic Maps for Large-scale Image Super-resolution

  • Wei, Zhensong;Bai, Huihui;Zhao, Yao
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제13권8호
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    • pp.3942-3961
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    • 2019
  • Recently, the models of deep super-resolution networks can successfully learn the non-linear mapping from the low-resolution inputs to high-resolution outputs. However, for large scaling factors, this approach has difficulties in learning the relation of low-resolution to high-resolution images, which lead to the poor restoration. In this paper, we propose Stage Generative Adversarial Networks (Stage-GAN) with semantic maps for image super-resolution (SR) in large scaling factors. We decompose the task of image super-resolution into a novel semantic map based reconstruction and refinement process. In the initial stage, the semantic maps based on the given low-resolution images can be generated by Stage-0 GAN. In the next stage, the generated semantic maps from Stage-0 and corresponding low-resolution images can be used to yield high-resolution images by Stage-1 GAN. In order to remove the reconstruction artifacts and blurs for high-resolution images, Stage-2 GAN based post-processing module is proposed in the last stage, which can reconstruct high-resolution images with photo-realistic details. Extensive experiments and comparisons with other SR methods demonstrate that our proposed method can restore photo-realistic images with visual improvements. For scale factor ${\times}8$, our method performs favorably against other methods in terms of gradients similarity.

성인의 예방처치경험에 따른 스케일링 공포도 (Level of fear on scaling according to preventive treatment experiences in the adults)

  • 김수경;구지혜;김예진;박유진;윤희경;이다정;정은아;정은서
    • 한국치위생학회지
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    • 제17권3호
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    • pp.369-380
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    • 2017
  • Objectives: The purpose of this study is to investigate the effect of preventive treatment experience on scaling fear level. Methods: A total of 259 adults who had visited the dental clinic were analyzed. The results were summarized as follows. Statistical analysis of the collected data was performed using the SPSS WIN 20.0 statistical program. The general characteristics, scaling experience, and the characteristics of the subjects were analyzed. Frequency of scaling according to general characteristics was analyzed by independent sample t-test, Scaling fears according to treatment experience were tested by t-test. Correlation analysis was performed for scaling fears according to the reliability of dental hygienist. Regression analysis was carried out to investigate factors affecting scaling fear. Results: Level of fear during scaling was higher in females (3.03) than in males (2.54) and that after scaling was scored higher in females (2.68) than in males (2.34) by general characteristics (p<0.001). The adults who were not healthy in oral health showed the highest levels of fear during (3.29) and after (3.00) scaling by oral health status (p<0.001). Adults who had brushing education experience showed lower fear level than those who did not after scaling (p<0.01) according to the experiences of preventive treatments. With respect to the correlation of trust level to the dental hygienists with the scaling fears, it showed higher in the trust level (-0.688) as lower level of scaling fear (-0.642) in the scaling (p<0.01). Confidence level of dental hygienist (-0.661), brushing education experience (-0.121), and oral health status (-0.121) were influenced upon the regression analysis. Conclusions: Oral health education and dental hygiene education are increasing. It is thought that active efforts are needed to promote and maintain oral health.