• Title/Summary/Keyword: MOD04

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Prediction of Thermal-Hydraulic Phenomena in the LBLOCA Experiment L2-3 Using RELAP5/MOD2 (RELAP5/MOD2 코드에 의한 대형냉각재 상실사고 모사실험 L2-3의 열수력 현상 예측)

  • Bang, Young-Seok;Chung, Bub-Dong;Kim, Hho-Jung
    • Nuclear Engineering and Technology
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    • v.23 no.1
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    • pp.56-65
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    • 1991
  • The LOFT LOCE L2-3 was simulated using the RELAP5/MOD2 Cycle 36.04 code to assess its capability in predicting the thermal-hydraulic phenomena in LBLOCA of a PWR. The reactor vessel was simulated with two core channels and split downcomer modeling for a base case calculation using the frozen code. The result of the base calculation showed that the code predicted the hydraulic behavior, and the blowdown thermal response at high power region of the core reasonably and that the code had deficiencies in the critical How model during subcooled-two-phase transition period, in the CHF correlation at high mass flux and in the blowdown rewet criteria. An overprediction of coolant inventory due to the deficiencies yielded the poor prediction of reflood thermal response. Improvement of the code, RELAP5 / MOD2 Cycle 36.04, based on the sensitivity study increased the accuracy of the prediction of the rewet phenomena.

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Assessment of RELAP5MOD2 Cycle 36.04 using LOFT Intermediate Break Experiment L5-1 (LOFT중형 냉각재 상실 사고 모사 실험 자료 L5-1을 이용한 RELAP5/MOD2 Cycle 36.04 코드 평가)

  • Lee, E.J.;Chung, B.D.;Kim, H.J.
    • Nuclear Engineering and Technology
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    • v.23 no.1
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    • pp.66-80
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    • 1991
  • The LOFT intermediate break experiment L5-1, which simulates 12 inch diameter ECC line break in a typical PWR, has been analyzed using the reactor thermal/hydraulic analysis code RELAP5/MOD2, Cycle 36.04. The base calculation, which modeled the core with single flow channel and two heat structures without using the options of reflood and gap conductance model, has been successfully completed and compared with experimental data. Sensitivity studies were carried out to investigate the effects of nodalization at reactor vessel and core modeling on major thermal hydraulic parameters, especially on peak cladding temperature(PCT). These sensitivity items are : single flow channel and single heat structure (Case A), two flow channel and two heat structures (Case B), reflood option added (Case C) and both reflood and gap conductance options added (Case D). The code, RELAP5/MOD2 Cycle 36.04 with the base modeling, predicted the key parameters of LOFT IBLOCA Test L5-1 better than Cases A,B,C and D. Thus, it is concluded that the single flow channel modeling for core is better than the two flow channel modeling and two heat structure is also better than single heat structure modeling to predict PCT at the central fuel rods. It is, therefore, recommended to use the reflood option and not to use gap conductance option for this L5-1 type IBLOCA.

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Assessment of RELAP5/MOD2 with LOFT L2-5 LBLOCA Test (LOFT L2-5 대형 냉각제상실사고 모사실험에 대한 RELAP5/ MOD2 코드 평가)

  • Bang, Y.S.;Lee, S.Y.;Kim, H.J.;Kim, S.H.
    • Nuclear Engineering and Technology
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    • v.21 no.4
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    • pp.259-266
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    • 1989
  • An improved version of RELAP5/MOD2 Cycle 36.04 code is assessed for LOFI LBLOCA Test L2-5. Minor modifications to the original version have been done to avoic reflood related errors. Based on the modified version, one base case and two cases for sensitivity study on downcomer and core channel modelling are calculated. The calculation results are compared with the experimental data for primary system pressure, break mass How rate and cladding temperature at hot spot According to the comparison, it is found that the hydraulic system behaviors are well predicted, excessive core cooling exist in blowdown phase for a single core channel and a combined downcomer case, and a better result can be obtained for a two core channel case.

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Sr modified $PbTiO_3$ thin films for tunable microwave device application (MOD법에 의한 Sr modified $PbTiO_3$ 박막 제조 및 Tunable microwave device 응용 특성 연구)

  • Kang, D.H.;Cho, S.C.;Cha, H.J.;Cho, B.H.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.749-751
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    • 2002
  • $(Pb_{1-x}Sr_x)TiO_3$ $(0.6{\leq}x{\leq}0.8)$ thin films were prepared by the MOD method for tunable microwave device application and their characteristics were investigated as a function of Sr content(x) and applied field. Thin films showed a homogeneous microstructure and the tetragonality(c/a) was slightly decreased with increasing Sr content. With increasing Sr content, Curie temperature of the thin films showed a decreasing tendency. For the PST thin films, the dielectric constant at room temperature, Tc, and $tan{\delta}$ were 750~1900, $-70^{\circ}{\sim}-30^{\circ}C$ and 0.025~0.04, respectively.

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Characteristics of Atmospheric Aerosol Optical Thickness over the Northeast Asia Using TERRA/MODIS Data during the Year 2000~2005 (동북아시아 지역에서 TERRA/MODIS 위성자료를 이용한 2000~2005년 동안의 대기 에어러솔 광학두께 변화 특성)

  • Lee, Dong Ha;Lee, Kwon Ho;Kim, Jeong Eun;Kim, Young Joon
    • Atmosphere
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    • v.16 no.2
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    • pp.85-96
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    • 2006
  • The six-year (2000~2005) record of aerosol optical thickness (AOT or $\tau$) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) was analyzed over the Northeast Asia. The MODIS AOT standard products (MOD04_L2) over both ocean and land were collected to evaluate the spatial and temporal variability of the atmospheric aerosols over the study region ($32^{\circ}N{\sim}42^{\circ}N$ and $115^{\circ}E{\sim}133^{\circ}E$). The monthly averaged AOT result revealed slight changes(${\pm}0.002{\tau}/month$), which was almost unchangeable, over Korea. In contrast, the large AOT values (> 0.6) and a significant AOT increase (> 0.004 ${\tau}/month$) over East China were observed. For the analysis of spatio-temporal variability of AOT values, study area was divided by six sectors (I: North-East China, II: East China, III: Yellow Sea, IV: Korea Peninsular, V: East Sea, and VI: South Sea and Western part of Japan). The considerable result showed that particularly high AOT contribution was observed over sector I (32.5%) and II (25.5%) where some major urban and industrialized areas and agricultural fields are located and other cases were observed 13.2%, 14.6%, 7.1%, 7.0% over sector III, IV, V, and VI, respectively. In addition, yearly AOT changes based on seasons are observed differently at each sector but increasing trends reveal in summer and fall over all sectors.

Compression Method for IPSec over 6LoWPAN

  • Wang, Huqing;Sun, Zhixin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.4
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    • pp.1819-1831
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    • 2018
  • This paper focuses on a header compression method for the Authentication Header (AH) and Encapsulation Security Payload (ESP) for application to 6LoWPAN. Based on the context, an extendible compression method is developed by analysing each field of the AH and ESP. The method is carried out by resetting the AH and ESP header compression formats, adding a MOD field, and setting different working modes. Authentication, encryption, and a mixture of certification and encryption are provided as flexible options. In addition, the value of the original IPv6 extensible header ID (EID) field can be retained, while the number of occupied NHC_ID values can be decreased for future extendibility. The experimental results show the feasibility and validity of the current compression method. By comparison with other solutions, the new mechanism is demonstrated to be advantageous in terms of compression ratio, flexibility and extendibility.

A Method for Efficient Game Graphic Education Applied the MOD Type Game (MOD형 게임을 적용한 효율적인 게임그래픽 교육 방안)

  • Kim, Jong-Koo;Jung, Kwang-Ho
    • Proceedings of the Korea Information Processing Society Conference
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    • 2009.04a
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    • pp.1037-1040
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    • 2009
  • 본 논문에서는 게임그래픽 교육의 차별화를 위한 학습도구의 하나로 MOD형 게임을 이용한 학습방법을 도입하였다. MOD형 게임이란 수정 변형(Modification)이 가능한 게임이란 의미로, 그래픽 학습자들이 직접 작업한 소스를 게임에 적용해 볼 수 있는 기능을 제공하는 소프트웨어로 게임 그래픽의 특성을 이해하는데 필요한 실질적인 경험을 제공할 수 있다. MOD형 게임의 활용은 기존의 추상적 개념의 이론적 학습에서 불가능했던 실제적이고 구체적인 적용을 기반으로 하고 있기 때문에, 학습 효과와 게임그래픽 교육 방식과의 차별화를 가져온다.

A study for diagnosis and pattern identification of Hwa-Byung (화병의 진단 및 변증유형에 관한 연구)

  • Lee, Hui-Young;Park, Jong-Hoon;Whang, Wei-Wan;Kim, Jong-Woo
    • Journal of Oriental Neuropsychiatry
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    • v.16 no.1
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    • pp.1-17
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    • 2005
  • Objective : This empirical research is performed to recognize diagnostic concept, pattern identification, and clinical features of Hwa-byung. In other words, the aims of this research are to examine the differences of the diagnosis between Hwa-Byung and the other psychiatric disorders, and to find out pattern identification, and clinical characteristics of Hwa-Byung for prescriptions of this syndrome. Method : In the experiment, there were participated 30 patients who were met for our criterions according to HBDIS (Hwa-Byung Diagnostic interview Schedule). These patients were diagnosed as Axis1 according to criterions of DSM-IV with administering SCID-I. OMS-prime was utilized for finding out pattern identification of oriental medicine. Symptom Check List-90-Revision(SCL-90-R), Hemilton rating Scale for Depression(HRSD), Heart Rate Variability(HRV), and Digital Infrared Thermographic imaging(D.I.T.I.) were also utilized to discover clinical characteristics of Hwa-Byung Patients. Results : 1. Regarding Sex-ratio, male subjects were 3(10%), and female subjects are 27(90%). The age of subjects ranged from 22 year old to 75 $(51.87{\pm}11.04;\:Mean{\pm}SD)$ 2. In the results of diagnosis on the basis of DSM-IV, the 17(56.67%) patients were MOD (Major Depressive Disorder), the 5(16.67%) patients were USD (Undifferentiated Somatoform Disorder), the 4(13.33%) patients were Dysthymic Disorder, the 3(10%) patients were GAD (Generalized Anxiety Disorder), and the 1(3.33%) was Panic Disorder. Two of the patients who diagnosed as MOD were diagnosed as Panic Disorder too, and one of them was diagnosed as Pain Disorder too. 3. Regarding pattern identification, Hwa-Byung is positively correlated to deficiency of Heart(心). and then to stagnancy of Liver-Gall bladder. Hwa-Byung is correlated deficiency symptom-complex rather than excessiveness symptom-complex. That is also correlated positively to Pathological heat and fire. 4. In SCL90-R, the mean of PSDI was $(75.3{\pm}10.7;\:Mean{\pm}SD)$. The each mean of the other 11 factors was distributed between50-70. 5. The mean of HRSD was $(17.9{\pm}5.6;\:Mean{\pm}SD)$ in the entire subject's group. Then the group of MDD was $20.9{\pm}4.4$ and the group of USD was $12.0{\pm}4.8$ 6. In the results of HRV. the mean of TP is $972.4{\pm}1174(Mean{\pm}SD)$, this is lower than normal range 1000-200. The other factors were within normal range. Then, there were no significant differences between them (p<0.05). 7. The temperatures of each acupoint have significant differences between HNl(印堂) and PC6(內關), between CV17(顫中) and PC6(內關), between HN1(印堂) and CV8(神闕), between CV17(顫中) and CV8(神闕) in comparison with the average of body temperature in the use of D.I.T.I. (p<0.01) 8. In the analysis of correlation between SCL-90-R, HRSD, HRV. and D.I.T.I. there were no significant results. According to results that the correlation was analyzed with only the MDD group as subjects, there was negative correlation between RMSSD of HRV and HRSD, between LF of HRV and PDSIof SCL-90-R, and between LF/HF of HRV and ANX, PSY, and PDSI of SCL-90-R. Conclusion : In the observation of clinical features of 30 cases of Hwa-Byung patients by using diverse structured tests, there could make diverse diagnosis as depressive disorder, anxiety disorder, and Somatoform Disorder. Particularly. MDD was highly distributed. Considering oriental medicine's pattern identification of Hwa-Byung, this syndrome is related strongly to Heart, and there were demonstrated deficiency symptom-complex, and Pathological heat and fire. One of the limits of this study is lack of control subject's group, therefore, in the future study, it requires reexamination through a comparative research with these data to complete this study.

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Application of MODIS Aerosol Data for Aerosol Type Classification (에어로졸 종류 구분을 위한 MODIS 에어로졸 자료의 적용)

  • Lee, Dong-Ha;Lee, Kwon-Ho;Kim, Young-Joon
    • Korean Journal of Remote Sensing
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    • v.22 no.6
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    • pp.495-505
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    • 2006
  • In order to classify aerosol type, Aerosol Optical Thickness (AOT) and Fine mode Fraction (FF), which is the optical thickness ratio of small particles$(<1{\mu}m)$ to total particles, data from MODIS (MODerate Imaging Spectraradiometer) aerosol products were analyzed over North-East Asia during one year period of 2005. A study area was in the ocean region of $20^{\circ}N\sim50^{\circ}N$ and $110^{\circ}E\simt50^{\circ}E$. Three main atmospheric aerosols such as dust, sea-salt, and pollution can be classified by using the relationship between AOT and FF. Dust aerosol has frequently observed over the study area with relatively high aerosol loading (AOT>0.3) of large particles (FF<0.65) and its contribution to total AOT in spring was up to 24.0%. Pollution aerosol, which is originated from anthropogenic sources as well as a natural process like biomass burning, has observed in the regime of high FF (>0.65) with wide AOT variation. Average pollution AOT was $0.31{\pm}0.05$ and its contribution to total AOT was 79.8% in summer. Characteristic of sea-salt aerosol was identified with low AOT (<0.3), almost below 0.1, and slightly higher FF than dust and lower FF than pollution. Seasonal analysis results show that maximum AOT $(0.33{\pm}0.11)$ with FF $(0.66{\pm}0.21)$ in spring and minimum AOT $(0.19{\pm}0.05)$, FF $(0.60{\pm}0.14)$ in fall were observed in the study area. Spatial characteristic was that AOT increasing trend is observed as closing to the eastern part of China due to transport of aerosols from China by the prevailing westerlies.