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A Development of Automatic Lineament Extraction Algorithm from Landsat TM images for Geological Applications (지질학적 활용을 위한 Landsat TM 자료의 자동화된 선구조 추출 알고리즘의 개발)

  • 원중선;김상완;민경덕;이영훈
    • Korean Journal of Remote Sensing
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    • v.14 no.2
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    • pp.175-195
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    • 1998
  • Automatic lineament extraction algorithms had been developed by various researches for geological purpose using remotely sensed data. However, most of them are designed for a certain topographic model, for instance rugged mountainous region or flat basin. Most of common topographic characteristic in Korea is a mountainous region along with alluvial plain, and consequently it is difficult to apply previous algorithms directly to this area. A new algorithm of automatic lineament extraction from remotely sensed images is developed in this study specifically for geological applications. An algorithm, named as DSTA(Dynamic Segment Tracing Algorithm), is developed to produce binary image composed of linear component and non-linear component. The proposed algorithm effectively reduces the look direction bias associated with sun's azimuth angle and the noise in the low contrast region by utilizing a dynamic sub window. This algorithm can successfully accomodate lineaments in the alluvial plain as well as mountainous region. Two additional algorithms for estimating the individual lineament vector, named as ALEHHT(Automatic Lineament Extraction by Hierarchical Hough Transform) and ALEGHT(Automatic Lineament Extraction by Generalized Hough Transform) which are merging operation steps through the Hierarchical Hough transform and Generalized Hough transform respectively, are also developed to generate geological lineaments. The merging operation proposed in this study is consisted of three parameters: the angle between two lines($\delta$$\beta$), the perpendicular distance($(d_ij)$), and the distance between midpoints of lines(dn). The test result of the developed algorithm using Landsat TM image demonstrates that lineaments in alluvial plain as well as in rugged mountain is extremely well extracted. Even the lineaments parallel to sun's azimuth angle are also well detected by this approach. Further study is, however, required to accommodate the effect of quantization interval(droh) parameter in ALEGHT for optimization.

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A Study of Various Filter Setups with FBP Reconstruction for Digital Breast Tomosynthesis (디지털 유방단층영상합성법의 FBP 알고리즘 적용을 위한 다양한 필터 조합에 대한 연구)

  • Lee, Haeng-Hwa;Kim, Ye-Seul;Lee, Youngjin;Choi, Sunghoon;Lee, Seungwan;Park, Hye-Suk;Kim, Hee-Joung;Choi, Jae-Gu;Choi, Young-Wook
    • Progress in Medical Physics
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    • v.25 no.4
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    • pp.271-280
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    • 2014
  • Recently, digital breast tomosynthesis (DBT) has been investigated to overcome the limitation of conventional mammography for overlapping anatomical structures and high patient dose with cone-beam computed tomography (CBCT). However incomplete sampling due to limited angle leads to interference on the neighboring slices. Many studies have investigated to reduce artifacts such as interference. Moreover, appropriate filters for tomosynthesis have been researched to solve artifacts resulted from incomplete sampling. The primary purpose of this study is finding appropriate filter scheme with FBP reconstruction for DBT system to reduce artifacts. In this study, we investigated characteristics of various filter schemes with simulation and prototype digital breast tomosynthesis under same acquisition parameters and conditions. We evaluated artifacts and noise with profiles and COV (coefficinet of variation) to study characteristic of filter. As a result, the noise with parameter 0.25 of Spectral filter reduced by 10% in comparison to that with only Ramp-lak filter. Because unbalance of information reduced with decreasing B of Slice thickness filter, artifacts caused by incomplete sampling reduced. In conclusion, we confirmed basic characteristics of filter operations and improvement of image quality by appropriate filter scheme. The results of this study can be utilized as base in research and development of DBT system by providing information that is about noise and artifacts depend on various filter schemes.

Convolution-Superposition Based IMRT Plan Study for the PTV Containing the Air Region: A Prostate Cancer Case (Convolution-Superposition 알고리즘을 이용한 치료계획시스템에서 공기가 포함된 표적체적에 대한 IMRT 플랜: 전립선 케이스)

  • Kang, Sei-Kwon;Yoon, Jai-Woong;Park, Soah;Hwang, Taejin;Cheong, Kwang-Ho;Han, Taejin;Kim, Haeyoung;Lee, Me-Yeon;Kim, Kyoung Ju;Bae, Hoonsik
    • Progress in Medical Physics
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    • v.24 no.4
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    • pp.271-277
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    • 2013
  • In prostate IMRT planning, the planning target volume (PTV), extended from a clinical target volume (CTV), often contains an overlap air volume from the rectum, which poses a problem inoptimization and prescription. This study was aimed to establish a planning method for such a case. There can be three options in which volume should be considered the target during optimization process; PTV including the air volume of air density ('airOpt'), PTV including the air volume of density value one, mimicking the tissue material ('density1Opt'), and PTV excluding the air volume ('noAirOpt'). Using 10 MV photon beams, seven field IMRT plans for each target were created with the same parameter condition. For these three cases, DVHs for the PTV, bladder and the rectum were compared. Also, the dose coverage for the CTV and the shifted CTV were evaluated in which the shifted CTV was a copied and translated virtual CTV toward the rectum inside the PTV, thus occupying the initial position of the overlap air volume, simulating the worst condition for the dose coverage in the target. Among the three options, only density1Opt plan gave clinically acceptable result in terms of target coverage and maximum dose. The airOpt plan gave exceedingly higher dose and excessive dose coverage for the target volume whereas noAirOpt plan gave underdose for the shifted CTV. Therefore, for prostate IMRT plan, having an air region in the PTV, density modification of the included air to the value of one, is suggested, prior to optimization and prescription for the PTV. This idea can be equally applied to any cases including the head and neck cancer with the PTV having the overlapped air region. Further study is being under process.

Analysis of Acquisition Parameters That Caused Artifacts in Four-dimensional (4D) CT Images of Targets Undergoing Regular Motion (표적이 규칙적으로 움직일 때 생기는 4DCT 영상의 모션 아티팩트(Motion Artifact) 관련된 원인분석)

  • Sheen, Heesoon;Han, Youngyih;Shin, Eunhyuk
    • Progress in Medical Physics
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    • v.24 no.4
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    • pp.243-252
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    • 2013
  • The aim of this study was to clarify the impacts of acquisition parameters on artifacts in four-dimensional computed tomography (4D CT) images, such as the partial volume effect (PVE), partial projection effect (PPE), and mis-matching of initial motion phases between adjacent beds (MMimph) in cine mode scanning. A thoracic phantom and two cylindrical phantoms (2 cm diameter and heights of 0.5 cm for No.1 and 10 cm for No.2) were scanned using 4D CT. For the thoracic phantom, acquisition was started automatically in the first scan with 5 sec and 8 sec of gantry rotation, thereby allowing a different phase at the initial projection of each bed. In the second scan, the initial projection at each bed was manually synchronized with the inhalation phase to minimize the MMimph. The third scan was intentionally un-synchronized with the inhalation phase. In the cylindrical phantom scan, one bed (2 cm) and three beds (6 cm) were used for 2 and 6 sec motion periods. Measured target volume to true volume ratios (MsTrueV) were computed. The relationships among MMimph, MsTrueV, and velocity were investigated. In the thoracic phantom, shorter gantry rotation provided more precise volume and was highly correlated with velocity when MMimph was minimal. MMimph reduced the correlation. For moving cylinder No. 1, MsTrueV was correlated with velocity, but the larger MMimph for 2 sec of motion removed the correlation. The volume of No. 2 was similar to the static volume due to the small PVE, PPE, and MMimph. Smaller target velocity and faster gantry rotation resulted in a more accurate volume description. The MMimph was the main parameter weakening the correlation between MsTrueV and velocity. Without reducing the MMimph, controlling target velocity and gantry rotation will not guarantee accurate image presentation given current 4D CT technology.

Temperature-dependent Development and Its Model of the Greenbug, Schizaphis graminum (Rondani) (Homoptera: Aphididae) (보리두갈래진딧물 [Schizaphis graminum (Rondani)]의 온도발육과 발육모형)

  • Lee, Jang-Ho;Kim, Tae-Heung;Kim, Ji-Soo;Hwangn, Chang-Yeon;Lee, Sang-Guei
    • Korean journal of applied entomology
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    • v.46 no.2
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    • pp.213-219
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    • 2007
  • The development of Schizaphis graminum (Rondani) was studied at various constant temperatures ranging from 15 to $32.5^{\circ}C$, with $65{\pm}5%$ RH, and a photoperiod of 16L:8D. Mortality of the $1_{st}-2_{nd}\;and\;the\;3_{rd}-4_{th}$ stage nymphs were similar at most temperature ranges while at high temperature of $32.5^{\circ}C$, more $3_{rd}-4_{th}$ stage individuals died. The total developmental time ranged from 13.8 days at $15^{\circ}C$ to 4.9 days at $30.0^{\circ}C$ suggesting that the higher the temperature, the faster the development. However, at higher end temperature of $32.5^{\circ}C$ the development took 6.4 days. The lower developmental threshold temperature and effective accumulative temperatures for the total immature stage were $6.8^{\circ}C$ and 105.9 day-degrees, respectively and the nonlinear shape of temperature related development was well described by the modified Sharpe and DeMichele model. The normalized cumulative frequency distributions of developmental period for each life stage were fitted to the three-parameter Weibull function. The attendance of shortened developmental times was apparent with $1_{st}-2_{nd}\;nymph,\;3_{rd}-4_{th}$ nymph, and total nymph stages in descending order. The coefficient of determination $r^2$ ranged between 0.80 and 0.87.

Development Model of the Foxglove Aphid, Aulacorthum solani (Kaltenbach) on Lettuce (상추에서의 싸리수염진딧물(Aulacorthum solani)의 발육과 발육모형)

  • Lee, Sang-Guei;Kim, Hyeong-Hwan;Kim, Tae-Heung;Park, Gil-Jun;Kim, Kwang-Ho;Kim, Ji-Soo
    • Korean journal of applied entomology
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    • v.47 no.4
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    • pp.359-364
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    • 2008
  • The development of Aulacorthum solani (Kaltenbach) was studied at temperatures ranging from 12.5 to $27.5^{\circ}C$ under $65{\pm}5%$ RH, and a photoperiod of 16:8 (L:D). Mortality of $1st{\sim}2nd$ nymph was higher than that of $3rd{\sim}4th$ nymph at the most temperature ranges whereas at high temperature of $27.5^{\circ}C$, more $3{\sim}4th$ nymph stage individuals died. The total developmental time ranged from 16.9 days at $12.5^{\circ}C$ to 6.6days at $22.5^{\circ}C$, suggesting that higher the temperature, faster the development. However, at higher temperature of $25^{\circ}C$ the development took 7.4 days. The lower developmental threshold temperature and effective accumulative temperatures for the total immature stage were $0.08^{\circ}C$ and 162.8 day-degreeslated development. The nonlinear shape of temperature rewas well described by the modified Sharpe and DeMichele model. When the normalized cumulative frequency distributions of developmental times for each life stage were fitted to the three-parameter Weibull function, attendance of shortened developmental times was apparent with in $1{\sim}2nd$ nymph, $3{\sim}4th$ nymph, and total nymph stages in descending order. The coefficient of determination $r^2$ ranged between 0.86 and 0.91.

Development of Acquisition and Analysis System of Radar Information for Small Inshore and Coastal Fishing Vessels - Suppression of Radar Clutter by CFAR - (연근해 소형 어선의 레이더 정보 수록 및 해석 시스템 개발 - CFAR에 의한 레이더 잡음 억제 -)

  • 이대재;김광식;신형일;변덕수
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.39 no.4
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    • pp.347-357
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    • 2003
  • This paper describes on the suppression of sea clutter on marine radar display using a cell-averaging CFAR(constant false alarm rate) technique, and on the analysis of radar echo signal data in relation to the estimation of ARPA functions and the detection of the shadow effect in clutter returns. The echo signal was measured using a X -band radar, that is located on the Pukyong National University, with a horizontal beamwidth of $$3.9^{\circ}$$, a vertical beamwidth of $20^{\circ}$, pulsewidth of $0.8 {\mu}s$ and a transmitted peak power of 4 ㎾ The suppression performance of sea clutter was investigated for the probability of false alarm between $l0-^0.25;and; 10^-1.0$. Also the performance of cell averaging CFAR was compared with that of ideal fixed threshold. The motion vectors and trajectory of ships was extracted and the shadow effect in clutter returns was analyzed. The results obtained are summarized as follows;1. The ARPA plotting results and motion vectors for acquired targets extracted by analyzing the echo signal data were displayed on the PC based radar system and the continuous trajectory of ships was tracked in real time. 2. To suppress the sea clutter under noisy environment, a cell averaging CFAR processor having total CFAR window of 47 samples(20+20 reference cells, 3+3 guard cells and the cell under test) was designed. On a particular data set acquired at Suyong Man, Busan, Korea, when the probability of false alarm applied to the designed cell averaging CFAR processor was 10$^{-0}$.75/ the suppression performance of radar clutter was significantly improved. The results obtained suggest that the designed cell averaging CFAR processor was very effective in uniform clutter environments. 3. It is concluded that the cell averaging CF AR may be able to give a considerable improvement in suppression performance of uniform sea clutter compared to the ideal fixed threshold. 4. The effective height of target, that was estimated by analyzing the shadow effect in clutter returns for a number of range bins behind the target as seen from the radar antenna, was approximately 1.2 m and the information for this height can be used to extract the shape parameter of tracked target..

Quantifying Uncertainty of Vitamin C Determination in Infant Formula by Indophenol Titration Method (인도페놀 적정법에 의한 성장기용조제식 중 비타민 C 함량분석의 측정불확도 산정)

  • Jun, Jang-Young;Kwak, Byung-Man;Ahn, Jang-Hyuk;Kong, Un-Young
    • Korean Journal of Food Science and Technology
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    • v.37 no.3
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    • pp.352-359
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    • 2005
  • Uncertainty involved during determination of vitamin C content in infant formula was quantified by indophenol titration method. Uncertainty sources in measurand, such as purity, weight, final volume of standard, volume of standard solution used for titration, sample weight, final volume of sample, extraction solution used for titration, titration of extraction solution and standard solution by indophenol solution were identified and used as parameters for combined standard uncertainty based on Guide to the expression of uncertainty in measurement (GUM) and Draft EURACHEM/CITAC Guide. Uncertainty parameters of each source in measurand were identified as resolution, reproducibility and stability of chemical balance, standard material purity, repeatability, reproducibility, end point of titration, 1 mL pipet, 5 mL autopipet, and 100 mL mass flask. Each uncertainty component was evaluated by types A and B and included to calculate combined uncertainty. Analytical test result for traceability under laboratorial conditions using Certified Reference Material (CRM) test was certified as $108.4{\pm}1.7mg/100g$, which was within CRM certification range of $114.6{\pm}6.6mg/100g$. Uncertainty test result of vitamin C content of 5 g sampling was $56.7{\pm}2.44mg/100g$. Uncertainty could be reduced by identification of uncertainty sources and components related with vitamin C determination by indophenol titration method and by decreasing uncertainty sources and components.

Preparation of Semi-Solid Apple-Based Baby Food (반고형 사과 이유보충식의 제조)

  • Sohn, Kyung-Hee;Kim, Mi-Ran;Yim, Sung-Kyoung;Park, Hyun-Kyung;Park, Ok-Jin
    • Korean Journal of Food Science and Technology
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    • v.34 no.1
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    • pp.43-50
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    • 2002
  • To develop commercial semi-solid apple baby food, the physicochemical characteristics of apple puree in relation to different preparing methods and the effect of the addition methods of ascorbic acid on browning reaction were investigated. The preparing methods were classified into 3 groups by initial heating treatment: no heating (A), steaming at $120^{\circ}C$ (B), and blancing at $100^{\circ}C$ (C). The viscosity of tested apple puree was $2,600{\sim}5,856\;cp$, and contents of anhydrogalaturonic acid (AGA) and neutral sugar ranged $4.15{\sim}11.92\;mg%$ and $6.18{\sim}10.65\;mg%$, respectively. Among free sugars tested, level of fructose was the highest $(5.43{\sim}8.87%)$, followed by glucose $(2.11{\sim}4.23%)$, sucrose $(1.64{\sim}2.94%)$, in that order. Since small amounts of ascorbic acid were detected $(1.54{\sim}1.83\;mg%)$, it seemed to be lost by heating process in preparing of apple puree. For apple puree A, its lightness was lower and redness was higher than those of apple puree B and C. Its degree of browning of apple puree was so high that sodium ascorbic acid was added as a antibrowning agent. Puree had low sensory score and nutrient quality. The adding methods of ascorbic acid were classified into 4 groups by adding time: dipping, blending (2), heating (3), and blending + heating (4). Considering color and preference evaluation, preparing method B and adding method 2 showed the highest inhibitory activity on apple puree browning and desirable color for retort baby food. After retort sterilization, the viscosity of apple baby food was decreased from 3,477 cp to 2,294 cp, thiamin was destroyed completely, and the contents of riboflavin and ascorbic acid were decreased 41% and 21%, respectively. However, contents of free sugar and free amino acid and sensory parameter were not influenced by retort sterilization. In overall, the preparing method B-adding method 2 was a good processing condition for the retort apple baby food.

The Relation of BMI, Smoking and Drinking with Biomedical Parameters in 20s and 30s Men (20~30대 성인 남성에서 체질량지수, 흡연량 및 음주량과 혈액검사치의 관련성)

  • Kim, Chul-Gyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.10
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    • pp.4425-4433
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    • 2011
  • The purpose of this study was to explore the relation of BMI, smoking and drinking with biomedical parameters in 20s and 30s men. This was a retrospective exploratory study and the subjects were 603 men who participated in health check-up for clinical trial at a tertiary hospital between October 2006 and June 2011. RBC, hemoglobin(Hb), hematocrit(Hct), triglyceride(TG), uric acid(UA), ALT in obese group were significantly higher than those of normal weight group. WBC and Hb in smokers were significantly higher than those of nonsmokers, protein in smokers was significantly lower than that of nonsmokers. Platelet in moderate smokers who smoke 10~19 cigarettes a day was significantly higher than that of nonsmokers and light smokers who smoke below 10 cigarettes a day, albumin in moderate smokers was significantly lower than that of nonsmokers and light smokers. TG in moderate smokers was significantly higher than that of nonsmokers, and blood glucose(BG) in moderate smokers was significantly lower than that of nonsmokers. AST and ALT in drinkers who drink over 10g a day were significantly higher than those of nondrinkers. In regression, BMI was significant factors of increasing RBC, Hb, Hct, total cholesterol(TC), TG, BG, UA, AST and ALT. Smoking amount was significant factors of increasing WBC, Hb, Hct and TG, and was significant factors of decreasing BG and Ca. Smoking amount was significant factors of increasing TC, AST and ALT, and was significant factors of decreasing WBC. In conclusion, there was significant relations of BMI, smoking, and drinking with biomedical parameters such as Hb, TC, TG, and ALT in young-aged men. Therefore, practice of healthy lifestyle activities to include preventing obesity and heavy drinking, and quitting smoking needs to the 20s and 30s men for preventing lifestyle disease.