• Title/Summary/Keyword: Homogeneity-range

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The Relocation Effect of Observation Station on the Homogeneity of Seasonal Mean of Diurnal Temperature Range (기상관측소의 이전이 계절평균 일교차의 균질성에 미치는 영향)

  • Kim, Ji-Hyun;Suh, Myoung-Seok;Hong, Soon-Hee
    • Atmosphere
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    • v.20 no.4
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    • pp.437-449
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    • 2010
  • The relocation effect of observation station (REOS) on the homogeneity of seasonal mean of maximum and minimum temperature, diurnal temperature range (DTR) and relative humidity (RH) was investigated using surface observation data and document file. Twelve stations were selected among the 60 stations which have been operated more than 30 years and relocated over one time. The data from Chunpungryeong station were used as a reference to separate the impacts of station relocation from the effects caused by increased green house gases, urbanization, and others. The REOS was calculated as a difference between REOS of relocated station and REOS of reference station. Although the REOS is clearly dependent on season, meteorological elements, and observing stations, statistically significant impacts are found in many stations, especially the environment of observing station after relocation is greatly changed. As a result, homogeneity of seasonal mean of meteorological elements, especially DTR and RH, is greatly reduced. The results showed that the effect of REOS, along with the effect of urbanization, should be eliminated for the proper estimation of climate change from the analysis of long-term observation data.

A GENERALIZATION OF THE INTRACLASS CORRELATION IN CLUSTER SAMPLING

  • KIM KYU-SEONG
    • Journal of the Korean Statistical Society
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    • v.34 no.3
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    • pp.185-195
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    • 2005
  • This article is concerned with the intraclass correlation in survey sampling. From a design-based viewpoint the intraclass correlation is generalized to a finite population with unequal sized clusters. Under simple random cluster sampling the intraclass correlation is given in an explicit form, which is a generalization of the usual one. The range of it is found and the design effect is expressed by means of it. An example is given to compare the intraclass correlation with the homogeneity measure numerically, which shows that two measures are not the same except some limited cases.

Computer Simulation of the Electric Potential Distribution of Human Cross Section (심장 횡단면의 전위분포 컴퓨터 시뮬레이션)

  • 고용훈;박상희
    • Journal of Biomedical Engineering Research
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    • v.3 no.2
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    • pp.65-70
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    • 1982
  • This paper presents a new method of solving the electric potential distribution using the finite element method. The thoracic region surrounded by the body surface and the heart is discretized into finite elements and the Continuous Laplace-equation is transformed into one of the finite degrees of freedom. The current source density, the conductivity, and the excitable range is obtained by the references. From the result of simulation, it was revealed that the potential pattern of in homogeneity was much different from that of homogeneity.

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A Pyramid Fusion Method of Two Differently Exposed Images Using Gray Pixel Values (계조 화소 값을 이용한 노출속도가 다른 두 영상의 피라미드 융합 방법)

  • Im, Su Jin;Kim, Jin Heon
    • Journal of Korea Multimedia Society
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    • v.19 no.8
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    • pp.1386-1394
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    • 2016
  • Pyramid fusion usually adjusts the Laplacian weights of pixels of the input images by evaluating predefined criteria. This has advantages that it can selectively express intense color and enhance the contrast when applied to HDR exposure fusion. But it may cause noise because the weights are determined by pixel importance without considering the interdependent pixel relationship that constitutes a scene. This paper proposes a fusion method using simple weight criteria generated from the gray pixel values, which is expected to preserve the interdependent relationship and improve execution speed. In order to evaluate the performance of the proposed method we examine a homogeneity measure, H and compare the execution time for both methods. The proposed method is found to be more advantageous with respect to homogeneity and execution speed.

Homogeneity of Phospholipase C of Bovine Uterus and Seminal Vesicle Compared with Brain Isozymes (소의 자궁 및 고환에서 Phospholipase C의 분리 및 뇌 Isozyme과의 비교 연구)

  • Kim, Jung-Hye;Rhee, Sue-Goo;Lee, Ki-Yung
    • Journal of Yeungnam Medical Science
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    • v.5 no.2
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    • pp.37-45
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    • 1988
  • Phosphoinositide-specific phospholipase C(PI-PLC) is a second messenger of signal transducer on cell membrane. In the previous study, PLC of bovine brain has been purified three isozymes. In this paper, uterus and seminal vesicle have been purified. Two peaks of PI-PLC activity were resolved when bovine uterus and seminal vesicle proteins were chromatographed on a DEAE and phenyl TSK 5PW HPLC column. Each two peak was compared with PI-PLC I, IT and ill from bovine brain and we got the retension time on HPLC. The peak fractions with PLC activity were tested homogeneity with brain PLC monoclonal antibodies(Mab). Mab-labeled affigels were bounded in the range of 73.8%~97.5% with PLC I, IT and III. Homogeneity of fractions were revealed that DEAE F-1 and phenyl F-1-I were highest level of PLC III in uterus and seminal vesicle and DEAE F-2 and phenyl F-2-I were mixed PLC I and II.

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Segmentation and Classification of Range Data Using Phase Information of Gabor Fiter (Gabor 필터의 위상 정보를 이용한 거리 영상의 분할 및 분류)

  • 현기호;이광호;황병곤;조석제;하영호
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.8
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    • pp.1275-1283
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    • 1990
  • Perception of surfaces from range images plays a key role in 3-D object recognition. Recognition of 3-D objects from range images is performed by matching the perceived surface descriptions with stored object models. The first step of the 3-d object recognition from range images is image segmentation. In this paper, an approach for segmenting 3-D range images into symbolic surface descriptions using spatial Gabor filter is proposed. Since the phase of data has a lot of important information, the phase information with magnitude information can effectively segment the range imagery into regions satisfying a common homogeneity criterion. The phase and magnitude of Gabor filter can represent a unique featur vector at a point of range data. As a result, range images are trnasformed into feature vectors in 3-parameter representation. The methods not only to extract meaningful features but also to classify a patch information from range images is presented.

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Dose comparison according to Smooth Thickness application of Range compensator during proton therapy for brain tumor patient (뇌종양 환자의 양성자 치료 시 Range Compensator의 Smooth Thickness 적용에 따른 선량비교)

  • Kim, Tae Woan;Kim, Dae Woong;Kim, Jae Weon;Jeong, Kyeong Sik
    • The Journal of Korean Society for Radiation Therapy
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    • v.28 no.2
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    • pp.139-148
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    • 2016
  • Purpose : Range Compensator used for proton therapy compensates the proton beam dose which delivers to the normal tissues according to the Target's Distal Margin dose. We are going to check the improvement of dose on the target part by comparing the dose of PTV and OAR according to applying in different method of Smooth Thickness of Range Compensator which is used in brain tumor therapy. Materials and Methods : For 10 brain tumor patients taking proton therapy in National Cancer Center, Apply Smooth Thickness applied in Range Compensator in order from one to five by using Compensator Editor of Eclipse Proton Planning System(Version 10.0, Varian, USA). The therapy plan algorithm used Proton Convolution Superposition(version 8.1.20 or 10.0.28), and we compared Dmax, Dmin, Homogeneity Index, Conformity Index and OAR dose around tumor by applying Smooth Thickness in phase. Results : When Smooth Thickness was applied from one to five, the Dmax of PTV was decreased max 4.3%, minimum at 0.8 and average of 1.81%. Dmin increased max 1.8%, min 1.8% and average. Difference between max dose and minimum dose decreased at max 5.9% min 1.4% and average 2.6%. Homogeneity Index decreased average of 0.018 and Conformity Index didn't had a meaningful change. OAR dose decreased in Brain Stem at max 1.6%, min 0.1% and average 0.6% and in Optic Chiasm max 1.3%, min 0.3%, and average 0.5%. However, patient C and patient E had an increase each 0.3% and 0.6%. Additionally, in Rt. Optic Nerve, there was a decrease at max 1.5%, min 0.3%, and average 0.8%, however, patient B had 0.1% increase. In Lt. Optic Nerve, there was a decrease at max 1.8%, min 0.3%, and average 0.7%, however, patient H had 0.4 increase. Conclusion : As Smooth Thickness of Range Compensator which is used as the proton treatment for brain tumor patients is applied in stages, the resolution of Compensator increased and as a result the most optimized amount of proton beam dose can be delivered. This is considered to be able to irradiate the equal amount at PTV and reduce the unnecessary dose applied at OAR to reduce the side effects.

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Independence and Homogeneity Tests of the Annual Maxima Data used to Estimate the Design Wave Height (설계파고 추정에 사용한 연 최대 자료의 독립 및 분포 동질 검정)

  • Cho, Hong Yeon;Jeong, Weon Mu;Back, Jong Dai
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.32 no.1
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    • pp.26-38
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    • 2020
  • A statistical test was carried out on the IID (Independently and Identically Distributed) assumption of the AM (Annual Maxima) data used to estimate the design wave height. The test was divided into independence (randomness) test and homogeneity test, and each test was conducted on AM data of 210 and 310 stations in coastal and inner coastal grids in typhoon and non-typhoon (monsoon) conditions. As a result of the independence test, the rejection ratios of the test are in the range of 1.8~5.3% and 1.4~6.0% for the non-typhoon and typhoon data sets, respectively. On the other hand, in the distribution difference test of typhoon data and nontyphoon data, the same distribution hypothesis was found to be rejected in the range of 47~79% according to the test method for both coastal grid and inner coastal grid. Therefore, in estimating design wave height by extreme value analysis, the estimation process by dividing the typhoon and non-typhoon data is appropriate.

Dosimetric comparison of intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) in total scalp irradiation: a single institutional experience

  • Ostheimer, Christian;Hubsch, Patrick;Janich, Martin;Gerlach, Reinhard;Vordermark, Dirk
    • Radiation Oncology Journal
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    • v.34 no.4
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    • pp.313-321
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    • 2016
  • Purpose: Total scalp irradiation (TSI) is a rare but challenging indication. We previously reported that non-coplanar intensity-modulated radiotherapy (IMRT) was superior to coplanar IMRT in organ-at-risk (OAR) protection and target dose distribution. This consecutive treatment planning study compared IMRT with volumetric-modulated arc therapy (VMAT). Materials and Methods: A retrospective treatment plan databank search was performed and 5 patient cases were randomly selected. Cranial imaging was restored from the initial planning computed tomography (CT) and target volumes and OAR were redelineated. For each patients, three treatment plans were calculated (coplanar/non-coplanar IMRT, VMAT; prescribed dose 50 Gy, single dose 2 Gy). Conformity, homogeneity and dose volume histograms were used for plan. Results: VMAT featured the lowest monitor units and the sharpest dose gradient (1.6 Gy/mm). Planning target volume (PTV) coverage and homogeneity was better in VMAT (coverage, 0.95; homogeneity index [HI], 0.118) compared to IMRT (coverage, 0.94; HI, 0.119) but coplanar IMRT produced the most conformal plans (conformity index [CI], 0.43). Minimum PTV dose range was 66.8%-88.4% in coplanar, 77.5%-88.2% in non-coplanar IMRT and 82.8%-90.3% in VMAT. Mean dose to the brain, brain stem, optic system (maximum dose) and lenses were 18.6, 13.2, 9.1, and 5.2 Gy for VMAT, 21.9, 13.4, 14.5, and 6.3 Gy for non-coplanar and 22.8, 16.5, 11.5, and 5.9 Gy for coplanar IMRT. Maximum optic chiasm dose was 7.7, 8.4, and 11.1 Gy (non-coplanar IMRT, VMAT, and coplanar IMRT). Conclusion: Target coverage, homogeneity and OAR protection, was slightly superior in VMAT plans which also produced the sharpest dose gradient towards healthy tissue.

Efficient Image Specific Block Based LCD Backlight Nonideality and Cross-talk Compensation (Image에 따른 효과적인 LCD 백라이트 Block 단위 Nonideality 및 Cross-talk Compensation)

  • Han, Won-Jin;You, Jae-Hee
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.48 no.4
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    • pp.38-48
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    • 2011
  • Block based LCD backlight nonideality and crosstalk compensation methodologies are proposed based on the analysis of backlight profiles and image pixel homogeneity. Large computation complexity required in the conventional compensations is minimized without the degradation of image qualities by optimizing image block size, image area inside the block to be excluded from the compensation computation and the required backlight range to be computed. The optimization results of computation complexity as well as image qualities are verified for the proposed compensation by real image data simulations.