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Analysis of LBLOCA of APR1400 with 3D RPV model using TRACE

  • Yunseok Lee;Youngjae Lee;Ae Ju Chung;Taewan Kim
    • Nuclear Engineering and Technology
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    • v.55 no.5
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    • pp.1651-1664
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    • 2023
  • It is very difficult to capture the multi-dimensional phenomena such as asymmetric flow and temperature distributions with the one-dimensional (1D) model, obviously, due to its inherent limitation. In order to overcome such a limitation of the 1D representation, many state-of-the-art system codes have equipped a three-dimensional (3D) component for multi-dimensional analysis capability. In this study, a standard multi-dimensional analysis model of APR1400 (Advanced Power Reactor 1400) has been developed using TRACE (TRAC/RELAP Advanced Computational Engine). The entire reactor pressure vessel (RPV) of APR1400 has been modeled using a single 3D component. The fuels in the reactor core have been described with detailed and coarse representations, respectively, to figure out the impact of the fuel description. Using both 3D RPV models, a comparative analysis has been performed postulating a double-ended guillotine break at a cold leg. Based on the results of comparative analysis, it is revealed that both models show no significant difference in general plant behavior and the model with coarse fuel model could be used for faster transient analysis without reactor kinetics coupling. The analysis indicates that the asymmetric temperature and flow distributions are captured during the transient, and such nonuniform distributions contribute to asymmetric quenching behaviors during blowdown and reflood phases. Such asymmetries are directly connected to the figure of merits in the LBLOCA analysis. Therefore, it is recommended to employ a multi-dimensional RPV model with a detailed fuel description for a realistic safety analysis with the consideration of the spatial configuration of the reactor core.

Clinical Trial Protocol Development of Acupuncture for Disaster Survivors: Results from an Expert Survey (전문가 설문조사에 기반한 재난 경험자에 대한 침치료 임상연구 프로토콜 개발)

  • Huiyong Kwak;Chanyoung Kwon;Jungtae Leem;Sang-Ho Kim
    • Journal of Oriental Neuropsychiatry
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    • v.35 no.1
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    • pp.15-26
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    • 2024
  • Objectives: The objective of this study is to develop a specialized clinical research protocol for acupuncture treatment specifically designed for disaster survivors based on insights from an expert survey. Methods: An expert panel comprising specialists in neuropsychiatry, acupuncture, and clinical research methodology was assembled. Initial data to inform the clinical research protocol design was collected utilizing open-ended responses, multiple-choice questions, and a 5-point Likert scale to gauge agreement levels. Next, this data was disseminated to a panel of experts. A cohesive clinical research protocol was then formulated during a core panel meeting by integrating insights from a panel of 10 experts. Results: The protocol developed herein entails a non-randomized controlled study involving participants aged 19~64 years old who have been identified as high-risk or cautious according to the National Trauma Center screening test. The study design includes the establishment of an active control group, which allows for the assessment of an additional effect through comparison with conventional therapy. The selected acupuncture approach involves a combination of manual acupuncture and ear acupuncture. For clinical outcome assessment, the Clinician-Administered Posttraumatic Stress Disorder Scale for DSM-5 was proposed to gauge trauma symptoms. Representative scales for various domains such as depression, anxiety, anger, insomnia, pain, and quality of life were also provided for reference. Conclusions: The developed protocol is anticipated to streamline the swift design and initiation of clinical trials during disaster scenarios. It is also designed to be scalable, thereby enabling its application in both non-randomized control group studies and single-group before-and-after comparisons.

Critical Analysis of Cultural Imperialism - From Simplistic Imperialism to Dynamic Cultural Fluid (문화제국주의의 비판적 고찰 - 단선적 문화제국주의에서 역동적인 국제적 문화 유동으로)

  • Yim, Dong-Uk
    • Korean journal of communication and information
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    • v.45
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    • pp.151-186
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    • 2009
  • This article focuses on analysing and interpreting cultural imperialism issues that have long been debated. One of issues among them is related to the characteristics of international cultural fluid. What had been debated is that cultural imperialism has been ended or not and the debates were connected to the so called 'reverse cultural imperialism'. The other issue is about this fluid is the continuation of globalization or a part of localization and this is related to the phenomena of cultural homogenization or hybrid. General trend was that simplistic cultural imperialism which had been occurred during the 1970s and 1980s was no longer effective but global dominance by transnational global media is still strong and worldwide. Therefore my research interest is centered on how they look international cultural exchanges with regard to cultural imperialism. And is the framework of cultural imperialism thesis still effective tool in researching and analysing international cultural flows? How do we look globalization relating to international exchanges? Is globalization an another aspect of imperialism? In conclusion, international cultural fluid is not so simple. Like natural phenomena or human progress, a phenomenon is not consisted of a single factor or relation. Cultural fluid is a complex one mixed with various phenomena and relations. This is related to internal and external contradictions, internal and external dynamics of a society and nation, and social and cultural life of human beings. Recent research results show that globalization and localization are closely related to many country's programming schedule, and particular cultural interpretation of specific programmes and culture are adopted to the country's culture and patterns. Cultural fluid has both-sides. One the hand it has useful and positive sides and on the other hand it has harmful and negative aspects. Imperialistic factor, globalization, cultural homogenization or hybrid are all operated and functioned together in cultual fluid. It is difficult to say that cultural imperialism thesis has been ended because American and global media's dominance is still effective. What needed at this time for us is a complex and dynamic analysis of international cultural fluid instead of simplistic cultural imperialism.

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A 10b 100 MSample/s $1.4\;mm^2$ 56 mW 0.18 urn CMOS A/D Converter for Low-Power Multimedia Applications (저전력 멀티미디어 응용을 위한 10b 100 MSample/s $1.4\;mm^2$ 56 mW 0.18 um CMOS A/D 변환기)

  • Min Byoung-Han;Park Hee-Won;Chae Hee-Sung;Sa Doo-Hwan;Lee Seung-Hoon
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.12
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    • pp.53-60
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    • 2005
  • This work proposes a 10b 100 MS/s $1.4\;mm^2$ CMOS ADC for low-power multimedia applications. The proposed two-step pipeline ADC minimizes chip area and power dissipation at the target resolution and sampling rate. The wide-band SHA employs a gate-bootstrapping circuit to handle both single-ended and differential inputs with 1.2 Vp-p at 10b accuracy while the second-stage flash ADC employs open-loop offset sampling techniques to achieve 6b resolution. A 3-D fully symmetrical layout reduces the capacitor and device mismatch of the first-stage MDAC. The low-noise references are integrated on chip with optional off-chip voltage references. The prototype 10b ADC implemented in a 0.18 um CMOS shows the maximum measured DNL and INL of 0.59 LSB and 0.77 LSB, respectively. The ADC demonstrates the SNDR of 54 dB, the SFDR of 62 dB, and the power dissipation of 56 mW at 100 MS/s.

Floating Point Unit Design for the IEEE754-2008 (IEEE754-2008을 위한 고속 부동소수점 연산기 설계)

  • Hwang, Jin-Ha;Kim, Hyun-Pil;Park, Sang-Su;Lee, Yong-Surk
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.48 no.10
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    • pp.82-90
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    • 2011
  • Because of the development of Smart phone devices, the demands of high performance FPU(Floating-point Unit) becomes increasing. Therefore, we propose the high-speed single-/double-precision FPU design that includes an elementary add/sub unit and improved multiplier and compare and convert units. The most commonly used add/sub unit is optimized by the parallel rounding unit. The matrix operation is used in complex calculation something like a graphic calculation. We designed the Multiply-Add Fused(MAF) instead of multiplier to calculate the matrix more quickly. The branch instruction that is decided by the compare operation is very frequently used in various programs. We bypassed the result of the compare operation before all the pipeline processes ended to decrease the total execution time. And we included additional convert operations that are added in IEEE754-2008 standard. To verify our RTL designs, we chose four hundred thousand test vectors by weighted random method and simulated each unit. The FPU that was synthesized by Samsung's 45-nm low-power process satisfied the 600-MHz operation frequency. And we confirm a reduction in area by comparing the improved FPU with the existing FPU.

High Noise Margin LVDS I/O Circuits for Highly Parallel I/O Environments (다수의 병렬 입.출력 환경을 위한 높은 노이즈 마진을 갖는 LVDS I/O 회로)

  • Kim, Dong-Gu;Kim, Sam-Dong;Hwang, In-Seok
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.44 no.1
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    • pp.85-93
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    • 2007
  • This paper presents new LVDS I/O circuits with a high noise margin for use in highly parallel I/O environments. The proposed LVDS I/O includes transmitter and receiver parts. The transmitter circuits consist of a differential phase splitter and a output stage with common mode feedback(CMFB). The differential phase splitter generates a pair of differential signals which have a balanced duty cycle and $180^{\circ}$ phase difference over a wide supply voltage variation due to SSO(simultaneous switching output) noises. The CMFB output stage produces the required constant output current and maintains the required VCM(common mode voltage) within ${\pm}$0.1V tolerance without external circuits in a SSO environment. The proposed receiver circuits in this paper utilizes a three-stage structure(single-ended differential amp., common source amp., output stage) to accurately receive high-speed signals. The receiver part employs a very wide common mode input range differential amplifier(VCDA). As a result, the receiver improves the immunities for the common mode noise and for the supply voltage difference, represented by Vgdp, between the transmitter and receiver sides. Also, the receiver produces a rail-to-rail, full swing output voltage with a balanced duty cycle(50% ${\pm}$ 3%) without external circuits in a SSO environment, which enables correct data recovery. The proposed LVDS I/O circuits have been designed and simulated with 0.18um TSMC library using H-SPICE.

A Study on the Current Status and Policy Direction of Open Banking (오픈뱅킹(Open Banking)의 현황과 정책방향에 관한 연구)

  • Park, Jeongkuk;Kim, Injai
    • Journal of Service Research and Studies
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    • v.10 no.1
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    • pp.17-31
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    • 2020
  • Open banking, the global trend of the financial industry, is the driving force behind various innovations in the financial market in the future. The right policy direction and detailed tasks are important for triggering the differentiation and reunion of the financial industry. The purpose of this study is to investigate and analyze the background of open banking, domestic and international trends, and Korea's open banking policy. The policy directions and tasks for successful settlement and activation of open banking system are carefully suggested. Open banking is a policy to allow third party provider(TPP) access to bank accounts and open payment functions under the explicit consent of the customer. The opening of the open banking era is expected to begin competition and cooperation between banks and fintech companies in earnest, thus enhancing the competitiveness of the financial industry and contributing to the utility of financial consumers. To this end, policymakers should make every effort to advance open-ended financial settlement infrastructure, open banking legal grounds, and minimize side effects such as customer data leakage and poor financial system stability. Banks and fintech companies will need to focus on scattered customer financial information on a single platform and develop it into a convergence and discrimination of true financial services.

Design of a New Balanced Power Amplifier Utilizing the Reflected Input Power (입력단 반사전력을 이용하는 새로운 구조의 평형전력증폭기 설계)

  • Park, Chun-Seon;Lim, Jong-Sik;Cha, Hyeon-Won;Han, Sang-Min;Ahn, Dal
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.5
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    • pp.947-954
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    • 2009
  • This paper proposed a new balanced power amplifier using the reflected input of conventional balanced power amplifiers composed of branch line hybrid coupler. In general, the single-ended amplifier in balanced amplifiers does not have the perfect matching, so the reflected input power, in other words the leakage power, is terminated conventionally at the isolation port of hybrid coupler. However in this work, the leakage power is injected into the auxiliary amplifier, and its output power is combined to the output power of balanced amplifier. Therefore output power, efficiency, and 2-tone IMD3 performances of the proposed balanced amplifier are highly improved compared to the conventional balanced amplifier. For the verification of the proposed balanced amplifier, a conventional balanced amplifier and the proposed balanced amplifier are designed, fabricated and measured, and the measured results are compared. The proposed balanced amplifier shows the improvement in the output power(Pout), power added efficiency (PAE), and 2-tone IMD3 by 3dB, 5.2%, and $5{\sim}10dBc$, respectively, from the measurement.

Changes of Fruit Structure and Sugar Contents during the Fruit Growth and Development in 'Yumyeong' Peach [Prunus persica (L.) Batsch] (과실생육시기별 '유명' 복숭아의 과실조직 발달과 당 변화)

  • Cho, Myong-Dong;Park, Hee-Seung;Kim, Yong-Koo
    • Horticultural Science & Technology
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    • v.18 no.3
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    • pp.353-359
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    • 2000
  • 'Yumyeong' is one of the most popular peach varieties in Korea. This study was conducted to monitor the developments of cells and tissues, and the changes in sugar contents during fruit growth and development. At bloom, there were two rows of vascular tissues, and the number and the position of internal vascular bundles were consistent during the fruit growth, however, the number of vascular tissues were increased and the distribution was irregular in the flesh tissues. The tissues between the inner integument and the internal vascular bundles showed different development characteristics from other parenchyma cells which were consisted of small and dense cells containing tannins. Such observation suggested that the stone of peach was consisted of inner epidermis and cells in the internal vascular tissues. The outer epidermis consisted of single layer cells at bloom differrentiated into 1-2 layers by horizontal cell divisions on 14 days after full bloom. On 30 days after full bloom, the epidermis was consisted of 5-6 layers by vertical cell divisions. The cell layers consisting the outer epidermis were gradually decreased to 1-2 layers at maturity. The observations on the changes in the epidermis confirmed that some of the cells consisting the hypodermis of peach fruit were originated from the cells of outer epidermis. Tylosis was observed from 35 days after full bloom and the size and number of tylosis were increased until full fruit maturity. The sucrose content showed the tendency of sharp increase from 50 days to 120 days after full bloom then decrease slightly. After when stone hardening ended, other solids showed a gradual decrease tendency from 80 days after full bloom.

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Students' Experience and Preference on Student Activities in the Clothing & Textiles Section of Middle School 'Technology.Home Economics' Textbooks (중학교 기술.가정 교과서 의생활 영역 옷차림 단원의 활동과제에 대한 학습자의 수행경험과 선호도 조사 연구)

  • Eo, Ji-Hyun;Oh, Kyung-Wha
    • Journal of Korean Home Economics Education Association
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    • v.21 no.1
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    • pp.51-69
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    • 2009
  • This study is intended to provide fundamental information to improve the quality of student activities presented in the Clothing & Textiles How to Dress Appropriately' section of the current middle school 'Technology Home Economics' textbooks so that Home Economics may better reflect students' interests, making it applicable in real life. The survey was conducted to 154 male and 160 female students on their preferences regarding student activities. The results are as follows. First, students who like clothing & textiles section regard "Opportunities to take part in various kinds of practices and student activities" as the major reason for preference. And the single biggest reason why they dislike the unit was due to "Too much contents to be memorized." Among various contents regarding dress in the unit, "How to Wear Clothes That Look Good on Me, and the Right Ways to Wear Them" attracted the most attention, regardless of what contents they consider necessary, interesting, or helpful in real life. Second, as for the time of implementation of the activities, students preferred "End of each class". They also preferred small-group activities (group size), well-structured problems (type of problems) and tasks that require analysis based on theoretical principles through experiments and practices (methods of implementation). Third, the findings as to the actual experience of conducting the student activities indicated that, in most cases, student activities were conducted in accordance to what was suggested in the textbooks, but not to what the students preferred. Therefore, in order to make home economics more applicable to students, it is desirable to focus on their everyday lives as is favored by the students, and increase small-group activities. Also, suggesting various and comprehensive problematic situations such as non-structured, open-ended problems and encouraging diverse implementation would be helpful in improving students' critical and creative thinking abilities.

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