• Title/Summary/Keyword: VP2

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Contrast-Detail Phantom을 이용한 CR에서 Image Plate의 사용 횟수에 따른 Contrast-Detail Curve의 변화

  • Lee, Seung-Cheol;Park, Jang-Heum;Kim, Jae-Dong;Park, Chang-Hyeon
    • Korean Journal of Digital Imaging in Medicine
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    • v.7 no.1
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    • pp.7-13
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    • 2005
  • Purpose : Image plate (IP) is substituted for film in computed radiography. This study is to investigate into a variation of contrast and detail by the number used of image plate in computed radiography. Materials and Methods : A Contrast-Detail(CD)-RAD 2.0 phantom(Nijmegen hospital, The Netherlands) was used for this study. The computed radiography(CR) CD-RAD phantom images were acquired at 40 kVp, 160 mA, 1.6 mAs, and small focus with the Shimadzu general radiography UD-150B-10 system and Fuji FCR 5000 image process system with speed of 200. The IP used including once, 5000 times, and 10000 times also was used. The numerical value of image quality figures (IQF) was produced by CD-RAD analyser(the program is installed in the directory), and then contrast-detail curve was drawn. Results : In this study, the value of IQF was 3.53 in IP used once, 3.40 in 5000 times, and 3.22 in 10000 times. Conclusions : There was a variation of contrast-detail curve by the number used of IP with contrast-detail phantom in computed radiography. Therefore, it is necessary that the IP with lower IQF and a shift of contrast-detail curve to the lower left part is used.

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Bone Density Spatial Distribution of Radiation Dose Measurement (양방사선 골밀도 측정 장치의 공간산란선량분포측정)

  • Kim, Seon-Chil;Won, Do-Yeon;Park, Chang-Hee;Dong, Kyung-Rae
    • Korean Journal of Digital Imaging in Medicine
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    • v.13 no.2
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    • pp.59-62
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    • 2011
  • In this experiment, how DEXA(Dual-energy X-ray Absorptiometry) bone mineral density was measured using the equipment. In order to maintain the same measurement conditions, bone mineral density measurements of 10 cm thick phantom, with an actual patient at a point when examining the same conditions(100 kVp, 1 mA) and then out to the five doses of radiation and its average was calculated by dividing measured. X-ray dose rate measured at the Research Institute, Sword of the gamma survey meters calibrated MEDCOM Ltd. (Inspector GM counter tube) was used, calibration factor is 1.15. On a horizontal plane around the patient, depending on the distance was significantly reduced dose rate. In addition, orientation $0^{\circ}$ head end was higher in the direction of the highest dose rate, $0^{\circ}$ $180^{\circ}$ direction from the direction towards the higher dose rate reduced to some extent in the direction of all the $120^{\circ}$ were able to identify.

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The First Operation of Coal Combustion Test Facility in HANJUNG (HANJUNG 석탄 실험연소로의 초기운전)

  • Jang, G.H.;Chang, I.G.;Jeong, S.Y.;Chon, M.H.;Kim, J.S.
    • 한국연소학회:학술대회논문집
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    • 1998.10a
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    • pp.79-84
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    • 1998
  • In this paper we show design and operation of 1MWth pulverized coal combustion test facility. The test facility is consists of coal feeding system, furnace and flue gas treatment system. The furnace is equipped with a top-fired burner in order to avoid influence of gravity on the coal particles. There are two part of vertical(VP) and horizontal pass(HP) at furnace. We can measure temperature and species of coal flames in vertical pass. Also, there is horizontally arranged section where investigation regarding corrosion and deposit formation will be carried out. The burner of combustor was externally air staging burner(EASB) type made by IFRF. The pulverized high bituminous(Blair athol) coal from Australia was used as fuel, and the particle size less than 80 ${\mu}m$ was 83.4%. Overall excess air ratio was 1.2.

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Acoustical Analysis of Phonological Reduction in Conversational Japanese (일본어 회화문에 나타난 축약형의 음운론적 해석과 음향음성학적 분석)

  • Choi, Young-Sook
    • Speech Sciences
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    • v.8 no.4
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    • pp.229-241
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    • 2001
  • Using eighteen texts from various genera of present-day Japanese, I collected phonologically reduced forms frequently observed in conversational Japanese, and classified them in search of a unified. explanation of phonological phenomena. I found 7,516 cases of reduced forms which I divided into 43 categories according to the types of phonological changes they have undergone. The general tendencies are that deletion and fusion of a phoneme or an entire syllable takes place frequently, resulting in the decrease in the number of syllables. From a morphosyntactic point of view, phonological reduction often occurs at the NP and VP morpheme boundaries. The following findings are drawn from phonetical observations of reduction. (1) Vowels are more easily deleted than consonants. (2) Bilabials ([m], [b], and [w]) are the most likely candidates for deletion. (3) In a concatenation of vowels, closed vowels are absorbed into open vowels, or two adjacent vowels come to create another vowel, in which case reconstruction of the original sequence is not always predictable. (4) Alveolars are palatalized under the influence of front vowels. (5) Regressive assimilation takes place in a syllable starting with [r], changing the entire syllable into a phonological choked sound or a syllabic nasal, depending on the voicing of the following phoneme.

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Establishment of National Standard System for 240 kV High Voltage Transformer (240 kV 고전압 변성기 국가표준 시스템 구축)

  • Jung, Jae-Kap;Kwon, Sung-Won;Lee, Sang-Hwa;Kang, Jeon-Hong;Kim, Myung-Soo;Han, Sang-Gil;Kim, Yoon-Hyoung;Han, Sang-Ok
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.57 no.2
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    • pp.164-169
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    • 2008
  • National standard system for calibrating voltage transformer(VT) up to primary voltage of 240 kV have been established in 2005. The system consists of voltage source, regulating unit, VT testing unit, standard VT, VT under test and VT burden. To verify and validate the performance for 240 kV VT calibration system, the comparison with the National Measurement Institute of Australia(NMIA) has been performed using same VTs. The comparison results of the VTs mesured at the Korea Research Institute of Stansdards and Science(KRISS) are consistent with those measured at NMIA within 0.002 % for ratio error and 0.14 min for phase displacement in the primary voltage ranges of Vp = 3300 V - 22000 V with a secondary voltage of Vs = 110 V.

A Study on Application of Non-Destructive Equation for the Estimation of Concrete Strength (콘크리트의 압축강도 추정을 위한 비파괴시험식의 활용성 검토에 관한 연구)

  • Kim, Moo-Han;Kwon, Young-Jin
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.3 no.1
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    • pp.129-136
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    • 1999
  • In this paper, the new non-destructive equation will be proposed and evaluated in comparison to the other foreign's non-destructive equation. Through the comparisons cores strength of mock structure with compressive strength obtained from new non-destructive equation ; rebound hammer, ultra-sonic pulse velocity and combined method, it will be analyzed about application of non-destructive equation. The results are following. The new non-destructive equations follow ; (1) $F_c=9.5R{\cdot}N+62.5$ (2) $F_c=243Vp-739$ (3) $F_c=8.1R_o+205.3V_p-802$ where, $F_c$ : Compressive Strength, $R_o$ : Rebound Number. $V_p$ : Ultra-Sonic Pulse Velocity Trough the result of mock structure test, the combined method is superior to rebound method and ultra-sonic pulse velocity method in the estimation of concrete strength. In order to apply the non-destructive equation of concrete strength to the structures, it is necessary that we should be made process study on the non-destructive equation for estimation of concrete strength in the range, time and strength of application under long-term.

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On English Non-DP Subjects and their Structural Position (영어 non-DP 주어의 구조적 위치)

  • 홍성심
    • Language and Information
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    • v.6 no.2
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    • pp.1-14
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    • 2002
  • This paper discusses so called the non-DP subject constructions in English. In general, a subject is a DP that bears Nominative case and that occupies 〔Spec, IP〕. However, in some examples under investigation, it looks as if non-DP categories such as Prepositional Phrases(PP), Adjectival Phrases(AP), Adverbial Phrases (AdvP), Small Clauses (PreP or SC), and VP occupy the canonical subject position, 〔Spec, IP〕. Under the framework of Chomsky's (1993, 1995) along with his previous works (Chomsky 1981, 1986), the Case Checking mechanism undoubtedly assumes that only DPs can have Case Therefore, the Case Checking/Agree mechanism is stated such that the strong uninterpretable feature, in this case Case feature (D or NP) feature must be checked off in a certain manner. Therefore, any phrasal categories other than DPs are not included in the considerations. Nonetheless, there are many instances of non-DP categories in English that occupy the seemingly canonical subject position, 〔spec, IP〕. In this paper, it is proposed that the actual position of these non-DP subjects in English is not in Spec of IP. Rather, they occupy 〔Spec, TopP〕 under CP in the sense of Lasnik & Stowell (1991), Rizzi (1997), and Haegeman & Gueron (1999). In its effect, therefore, this paper extends the idea of Stowell (1981) who argues that the clausal subjects in English is not in 〔Spec, IP〕, but in 〔Spec, TopP〕. We further argue that Stowell's version of Case Resistance Principle must be extended in order to accomodate many more occurrences of so called non-DP subjects.

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Purple Image and Formative Properties in the Contemporary Fashion (현대(現代)패션에 나타난 Purple의 조형성(造形性)과 이미지)

  • Kim, Bong-Ju;Lee, Kyoung-Hee
    • Journal of Fashion Business
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    • v.6 no.4
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    • pp.163-172
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    • 2002
  • The purpose of this study is to investigate purple image and formative properties in contemporary fashion. For the study of formative properties 152 kinds of costume samples from photographs in fashion magazines. For the study of image 40 kinds of costume samples is used and divided into tones : pale(Vp, Lgr, L), bright(P, B), vivid(S, V, Dp), dark(Gr, Dl, Dgr, Dk). A total 24 pairs of abjective words were used to measure the semantic differential scale in this study. The data were analyzed by factor analysis, ANOVA, MDS and regression analysis. The results are as follows; 1. Factor analysis has extracted 5 factors which consist of purple image in contemporary fashion. The factors are high quality, hardness and softness, simplicity, temperature, maturity. 2. There were significant differences in visual evaluation of purple tones. 3. The discrimination among. 4 purple tones was related to weight of purple 4. The evaluative dimensions of purple image in modern fashion were identified by Light - Heavy and Pale - Strong. 5. The image effect on Preference, Buying needs, Pleasant and Riches was consist of complicated sensibility.

Comparison of Accuracy and Output Waveform of Devices According to Rectification Method (정류방식에 따른 장치의 정확도와 출력 파형의 비교)

  • Lee, In Ja
    • Journal of radiological science and technology
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    • v.41 no.6
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    • pp.603-610
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    • 2018
  • This study examined the following: accuracy of the exposure conditions in the inverter device and three-phase device; output waveform over the exposure conditions; and average and standard deviation of the output waveform. After assessing whether the dose corresponding to the theoretical dose was presented, the following conclusions were obtained: 1. The accuracy of the tube voltage(kVp) and tube current(mA) exposure time(sec) was within the tolerable level prescribed in Korea's Safety Management Standards. In the error, Inverter device was large the tube voltage and exposure time, the three-phase device was large the tube current. 2. In terms of the output waveform of the exposure conditions and the average and standard deviation of the output waveform, the higher tube voltage and larger tube current resulted in greater standard deviation in pulsation. Moreover, the standard deviation of pulsation was shown to be greater in the inverter device than the three-phase device; there was also greater standard deviation in the inverter device considering the exposure time. 3. Regarding the exposure conditions over the output dose, all linearity showed the coefficient of variation which had an allowable limit of error within 0.05. Although the output dose ratio for the inverter device was 1.00~1.10 times no difference that of the three-phase device, there was almost no difference in dose ratio between the tube currents.

Evaluation of Tungsten Blended Filament Shields Made by 3D Printer in Radiography (일반촬영분야에서의 3D 프린터로 제작한 텅스텐 혼합 필라멘트 차폐체의 성능평가)

  • Yoon, Joon;Yoon, Myenog-Seong
    • Journal of radiological science and technology
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    • v.44 no.6
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    • pp.615-621
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    • 2021
  • In the medical field, radiation provides information for the diagnosis and treatment of diseases. As the use of radiation increases and the risk of exposure increases, interest in radiation protection is also rapidly increasing. Lead shielding material is mainly used, which has a risk of lead poisoning and absorption into the body. Tungsten mixed filament shielding sheets were fabricated with a size of 70 × 70 mm and a thickness of 1, 2, and 4 mm by using a 3D printer. In the general shooting experiment, the thickness of the shielding sheet is 1 ~ 5mm, the tube voltage is 60, 80, 100, 120 kVp and the tube current is 20, 40 mAs. In general photography, Tungsten showed better shielding rate compared to Brass, Copper, and Lead protective tools under all irradiation conditions, and in particular, Tungsten 5 mm showed 100% shielding rate. The 3D-printed tungsten mixed filament shielding is expected to be used as a new shield that can replace the existing lead protection tools as it shows a better shielding rate than the existing lead protection tools in Radiography.