• Title/Summary/Keyword: Trend Curve

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Verification of SARAX code system in the reactor core transient calculation based on the simplified EBR-II benchmark

  • Jia, Xiaoqian;Zheng, Youqi;Du, Xianna;Wang, Yongping;Chen, Jianda
    • Nuclear Engineering and Technology
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    • v.54 no.5
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    • pp.1813-1824
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    • 2022
  • This paper shows the verification work of SARAX code system in the reactor core transient calculation based on the simplified EBR-II Benchmark. The SARAX code system is an analysis package developed by Xi'an Jiaotong University and aims at the advanced reactor R&D. In this work, a neutron-photon coupled power calculation model and a spatial-dependent reactivity feedback model were introduced. To verify the models used in SARAX, the EBR-II SHRT-45R test was simplified to an ULOF transient with an input flowrate change curve by fitting from reference. With the neutron-photon coupled power calculation model, SARAX gave close results in both power fraction and peak power prediction to the reference results. The location of the hottest assembly from SARAX and reference are the same and the relative power deviation of the hottest assembly is 2.6%. As for transient analysis, compared with experimental results and other calculated results, SARAX presents coincident results both in trend and absolute value. The minimum value of core net reactivity during the transient agreed well with the reported results, which ranged from -0.3$ to -0.35$. The results verify the models in SARAX, which are correct and able to simulate the in-core transient with reliable accuracy.

Fake News Detection on Social Media using Video Information: Focused on YouTube (영상정보를 활용한 소셜 미디어상에서의 가짜 뉴스 탐지: 유튜브를 중심으로)

  • Chang, Yoon Ho;Choi, Byoung Gu
    • The Journal of Information Systems
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    • v.32 no.2
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    • pp.87-108
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    • 2023
  • Purpose The main purpose of this study is to improve fake news detection performance by using video information to overcome the limitations of extant text- and image-oriented studies that do not reflect the latest news consumption trend. Design/methodology/approach This study collected video clips and related information including news scripts, speakers' facial expression, and video metadata from YouTube to develop fake news detection model. Based on the collected data, seven combinations of related information (i.e. scripts, video metadata, facial expression, scripts and video metadata, scripts and facial expression, and scripts, video metadata, and facial expression) were used as an input for taining and evaluation. The input data was analyzed using six models such as support vector machine and deep neural network. The area under the curve(AUC) was used to evaluate the performance of classification model. Findings The results showed that the ACU and accuracy values of three features combination (scripts, video metadata, and facial expression) were the highest in logistic regression, naïve bayes, and deep neural network models. This result implied that the fake news detection could be improved by using video information(video metadata and facial expression). Sample size of this study was relatively small. The generalizablity of the results would be enhanced with a larger sample size.

Seismic fragility analysis of base isolation reinforced concrete structure building considering performance - a case study for Indonesia

  • Faiz Sulthan;Matsutaro Seki
    • Structural Monitoring and Maintenance
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    • v.10 no.3
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    • pp.243-260
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    • 2023
  • Indonesia has had seismic codes for earthquake-resistant structures designs since 1970 and has been updated five times to the latest in 2019. In updating the Indonesian seismic codes, seismic hazard maps for design also update, and there are changes to the Peak Ground Acceleration (PGA). Indonesian seismic design uses the concept of building performance levels consisting of Immediate occupancy (IO), Life Safety (LS), and Collapse Prevention (CP). Related to this performance level, cases still found that buildings were damaged more than their performance targets after the earthquake. Based on the above issues, this study aims to analyze the performance of base isolation design on existing target buildings and analyze the seismic fragility for a case study in Indonesia. The target building is a prototype design 8-story medium-rise residential building using the reinforced concrete moment frame structure. Seismic fragility analysis uses Incremental Dynamic Analysis (IDA) with Nonlinear Time History Analysis (NLTHA) and eleven selected ground motions based on soil classification, magnitude, fault distance, and earthquake source mechanism. The comparison result of IDA shows a trend of significant performance improvement, with the same performance level target and risk category, the base isolation structure can be used at 1.46-3.20 times higher PGA than the fixed base structure. Then the fragility analysis results show that the fixed base structure has a safety margin of 30% and a base isolation structure of 62.5% from the PGA design. This result is useful for assessing existing buildings or considering a new building's performance.

A Study I on the fashion trends of wedding dresses in the 20th century (20세기 웨딩드레스의 유행변화에 관한 연구 I)

  • Shin, Kyeong-Seub
    • Journal of Fashion Business
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    • v.15 no.5
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    • pp.69-86
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    • 2011
  • The objective of this research is to unveil the dynamic changes of the trends in wedding dresses during the 20th Century. The studies were carried out in two forms; firstly by observing the actual wedding dresses worn by people at that time, and secondly by conducting formative comparisons between those dresses with the ones appeared in movies corresponding to that period. Movies provide an invaluable insight into the era's wedding dresses fashion trends since they function as intimate bridges in connection with the time's audience, and the visible imageries accurately reflect the characteristics embedded within that time frame. As there are no precedent studies regarding this topic, this thesis can serve as vital research data for the wedding dress industry. Research data regarding the actual wedding dresses were collected from books and museum web sites. The object of movies were films produced before World War II that contained both the background settings of the 20th Century and wedding dresses, of which photographic imageries were captured. Research analysis was then conducted by merging these data with findings from relevant books and internet materials. The results of the thesis are as the following: The 1900s was an extension of the 19th Century's popular fashion trend which can be characterized as the S curve silhouettes of the Edwardian period when long trains and long veils symbolized wealth and social power. In the 1910s, high waist silhouettes with soft wrinkles were prevalent as attire suitable for active mobility with practical functionality were highly regarded. During the 1920s, the flapper style became the dominant trend. Hem lines of the skirts were curled in the form of the scallop and laces were the most widely used raw materials. By the 1930s, wedding dresses that reinterpreted the glamorous sheath lines, practical two piece styles, and retro-styles became predominant. The 1940s saw the advent of ready-made wedding dresses made of synthesized materials; practical military style suits and casuals sometimes substituted the wedding dresses. And although the wedding dresses in the movies were primarily costumes to express the personalities of the characters, they were also reinterpreted as manifestations of the formative characteristics of each relative period that pursued very distinct and diverse features.

A Fundamental Study on the Fatigue Behavior in the Joints of Steel Members (강부재(鋼部材) 이음부(部)의 피로거동(疲勞擧動)에 관(關)한 기초적(基礎的) 연구(硏究))

  • Lee, Yong Jae;Chung, Yeong Wha
    • Journal of Industrial Technology
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    • v.9
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    • pp.21-28
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    • 1989
  • For the study of the fatigue behavior, high-strength bolted connections on a small scale were manufactured, and carried on fatigue tests. Its experimental values were analysed by stress-fatigue life (S-N) curve. Three types of specimens : the base metal, the cireular hole and the welded sperimens had same net section were made. Through the same tests those experimental values were compared with those of the high-strength bolted conneetions. The results of these studies are as followings. It was found that the fatigue strength in $F_{n=100,000}$ and $F_{n=2,000,000}$ of the high-strength bolted conneetions were much more about 14% and 16% than that of the base metal specimen. It was thought that this trend was due to frictional force increasing fatigue strength. It was known that fatigue strength in $F_{n=100,000}$ and $F_{n=2,000,000}$ of the welded joints were less 29% and 21% than that of base metal specimen. It was thought that that trend was due to weld flaw. It was appeared that the fatigue strength in $F_{n=100,000}$ and $F_{n=2,000,000}$ of the high-strength bolted connections were much more about 38% and 30% than that of welded joint. It was thought that it was due to both frictional force increasing the fatigue strength in bolted connections and weld flaw decreasing the fatigue strength in welded connections. It was found that the fatigue strength in $F_{n=100,000}$ and $F_{n=2,000,000}$ of the B3 specimens were much more 2% and -2% than that of the B4 specimen. It was thought that that trend was due to the frictional force, which concerned with shape of specimen. It was known that the fatigue strength in $F_{n=100,000}$ and $F_{n=2,000,000}$ of the specimen with circular hole was less 61% and 65% than that of base metal. It was known that the allowable stress for bolted joint was higher than that of welded Joints. If that research is continued and more data are accumulated it can be expected that a basic pattern to provided the indicator of the fatigue design of the bolted connections of steel structures and persume the safety and lifeproof of existing structures is given.

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Changes of C-Reactive Protein and Erythrocyte Sedimentation Rate Level from Infection and Non-Infection after the Artificial Joint Surgery (인공관절 수술 후 감염과 비 감염에 따른 C-반응성단백과 적혈구침강속도의 변화 추이)

  • Kim, Min-Ju;Kim, Hye-Jeong
    • Korean Journal of Clinical Laboratory Science
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    • v.48 no.4
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    • pp.321-326
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    • 2016
  • This study aimed to analyze the changes of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) measured in acute infection within four weeks post artificial joint surgery to predict potential infection in early stages, provide rapid treatment, and prevent the abuse of antibiotics. This study included 50 patients with acute infection and 50 patients without any symptoms of infection, among patients who received artificial joint replacement surgery on the lower limbs in a four-week period. CRP was the highest two-to-three days after surgery. with $5.77{\pm}3.69$ and $5.17{\pm}3.48$, respectively, in those with infection and without infection. Thereafter, the value rapidly reduced in those without infection. However, it increased again to $3.16{\pm}2.87$ in the group with infection according to the bimodal curve (p<0.001). ESR was the highest two-to-three days after surgery, with $58.8{\pm}24.63$ and $44.08{\pm}21.48$, respectively. Thereafter, the value slowly reduced in those without infection. However, it was increased again to $47.62{\pm}26.26$ in those with infection according to the bimodal curve p<0.001). As this study shows, if there is an increasing trend for CRP and ESR after artificial joint replacement surgery, it may be possible to question whether patients are acutely infected post surgery. In particular, this result is expected and regarded as a useful factor for diagnosing infection due to the high level of sensitivity and uniqueness for CRP.

The evolution of container port group in Bohai Rim of China (중국 보하이만 컨테이너 항만의 진화에 관한 연구)

  • Liu, Siwei;Nguyen, Tuan Hiep;Yeo, Gi Tae
    • Journal of Digital Convergence
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    • v.16 no.9
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    • pp.107-114
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    • 2018
  • Since China's economic reform in 1978, international trade has enormously flourished and the port industry is reckoned as a key factor contributing to this growth. This study examines the Bohai Rim port group in the scope of top three largest ports Qingdao, Dalian and Tianjin. By utilizing indicators including concentration ratio (CR), Herfindahl-Hirschman index (HHI), the Gini coefficient and the Lorenz curve as well as shift-share analysis (SSA), the concentration level of this port group in the period 2004-2016 is discussed. As a results, CR demonstrates a decrease during the studied period with a minor fluctuation, and HHI index shows a trend of deconcentration with Bohai Rim port group. In addition, SSA indicates that during the period 2004-2016, the overall shift index of Qingdao port was -1.371 meanwhile with Tianjin and Dalian port were 0.118 and 1.252 in turn. These results suggest that the growth in regional influence of Tianjin and Dalian ports would motivate to the deconcentration pattern in Bohai Rim region. The findings assist decision makers and scholars to obtain knowledge about the port development this region. Considering the geographic position of these three ports as the gate of northeast China, it is suggested that these three ports could explore their advantages and cooperate with the small ports in the surrounding area to enhance their influences in the future study.

A Study on the Improvement of Huff's Method for Applying in Korea : II. Improvement of Huff's Method (Huff 강우시간분포방법의 개선방안 연구 : II. Huff 방법의 개선방안)

  • Jang Su-Hyung;Yoon Jae-Young;Yoon Yong-Nam
    • Journal of Korea Water Resources Association
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    • v.39 no.9 s.170
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    • pp.779-786
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    • 2006
  • In this study, we propose a new method that utilizes rainfall data in and out of a basin, which is greater than 25.4mm for point rainfall or 12.7mm for areal mean rainfall respectively. From our analysis, most frequent quartile for point and areal mean rainfall were found to be the same in general for various rainfall duration intervals. From an evaluation of design rainfall per each rainfall duration distributed in time by the MOCT(Ministry of Construction and Transportation) version of Huff's method and this study, peak rainfall intensity by this study was found to be greater than the one by MOCT, but there were no consistent increase or decrease of this difference with rainfall durations. Using the distributed design rainfall per each duration by MOCT and this study, corresponding flood inflow hydrographs were simulated and compared each other. Contrary to the case of peak rainfall intensity, difference in peak flow by both methods per each rainfall duration started to increase from about 12-hr duration. Especially, the difference in peak flow was significant when critical rainfall duration was considered, and this trend was similar for peak flows of other rainfall durations. Therefore, the method proposed in this study is thought to be the effective procedure for the construction of dimensionless cumulative rainfall curve that is representative of a basin while considering time distribution characteristics for different rainfall durations.

Estimation of Hydraulic Parameters from Slug, Single Well Pumping and Step-drawdown Tests (순간수위 변화시험, 단공양수시험 및 단계양수시험을 통한 수리상수 추정연구)

  • Jo, Yun-Ju;Lee, Jin-Yong;Jun, Seong-Chun;Cheon, Jeong-Yong;Kwon, Hyung-Pyo
    • The Journal of Engineering Geology
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    • v.20 no.2
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    • pp.203-212
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    • 2010
  • The aim in this study is used to develop the remediation technologies for contaminated ground water. Slug, single well pumping and step-drawdown tests have been used to obtain hydraulic parameter estimates in the field. Slug tests yield hydraulic conductivity values using the Bouwer and Rice and C-B-P analysis methods. The mean and median hydraulic conductivity values of Bouwer and Rice method are $4.48{\times}10^{-3}$ and $1.16{\times}10^{-3}cm/sec$, respectively. On the other hand, C-B-P method gave mean and median hydraulic conductivity values of $2.37{\times}10^{-3}$ and $7.09{\times}10^{-4}cm/sec$, respectively. These analyses show a trend for the Bouwer and Rice method to yield lower hydraulic conductivity values in low permeability zones of granite in the study area. Sing well pumping test data were calculated through type curve in GW7, GW12 and MW9 wells. It could be interpreted that the differences of hydraulic conductivity and transmissivity values between GW7 and GW12, MW9 is related with fault clays and fractures in the bedrock among the wells. Step-drawdown tests were carried out in the KDPW1 and KDPW2 wells. The hydraulic parameter of KDPW1 and KDPW2 showed very litter difference between the values. The study of hydraulic parameter estimates can be used to purify in contaminated groundwater.

Developing the Accurate Method of Test Data Assessment with Changing Reliability Growth Rate and the Effect Evaluation for Complex and Repairable Products

  • So, Young-Kug;Ryu, Byeong-Jin
    • Journal of Applied Reliability
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    • v.15 no.2
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    • pp.90-100
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    • 2015
  • Reliability growth rate (or reliability growth curve slope) have the two cases of trend as a constant or changing one during the reliability growth testing. The changing case is very common situation. The reasons of reliability growth rate changing are that the failures to follow the NHPP (None-Homogeneous Poisson Process), and the solutions implemented during test to break out other problems or not to take out all of the root cause permanently. If the changing were big, the "Goodness of Fit (GOF)" of reliability growth curve to test data would be very low and then reduce the accuracy of assessing result with test data. In this research, we are using Duane model and AMSAA model for assessing test data and projecting the reliability level of complex and repairable system as like construction equipment and vehicle. In case of no changing in reliability growth rate, it is reasonable for reliability engineer to implement the original Duane model (1964) and Crow-AMSAA model (1975) for the assessment and projection activity. However, in case of reliability growth rate changing, it is necessary to find the method to increase the "GOF" of reliability growth curves to test data. To increase GOF of reliability growth curves, it is necessary to find the proper parameter calculation method of interesting reliability growth models that are applicable to the situation of reliability growth rate changing. Since the Duane and AMSAA models have a characteristic to get more strong influence from the initial test (or failure) data than the latest one, the both models have a limitation to contain the latest test data information that is more important and better to assess test data in view of accuracy, especially when the reliability growth rate changing. The main objective of this research is to find the parameter calculation method to reflect the latest test data in the case of reliability growth rate changing. According to my experience in vehicle and construction equipment developments over 18 years, over the 90% in the total development cases are with such changing during the developing test. The objective of this research was to develop the newly assessing method and the process for GOF level increasing in case of reliability growth rate changing that would contribute to achieve more accurate assessing and projecting result. We also developed the new evaluation method for GOF that are applicable to the both models as Duane and AMSAA, so it is possible to compare it between models and check the effectiveness of new parameter calculation methods in any interesting situation. These research results can reduce the decision error for development process and business control with the accurately assessing and projecting result.