• Title/Summary/Keyword: distorted power

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A Revisit to the Recent Human Error Events in Nuclear Power Plants Focused to the Organizational and Safety Culture

  • Lee, Yong-Hee
    • Journal of the Ergonomics Society of Korea
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    • v.32 no.1
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    • pp.117-124
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    • 2013
  • Objective: This paper presents additional considerations related to organization and safety culture extracted from recent human error incidents in Korea, such as station blackout(i.e., SBO) in Kori#1. Background: Safety culture has been already highlighted as a major cause of human errors after 1986 Chernobyl accident. After Fukushima accident in Japan, the public acceptance for nuclear energy has taken its toll. Organizational characteristics and culture became elucidated as a major contributor again. Therefore many nuclear countries are re-evaluating their safety culture, and discussing any preparedness and its improvement. On top of that, there was an SBO in 2012 in the Kori#1. Korean public feels frustrated due to the similar human errors causing to a catastrophe like Fukushima accident. Method: This paper reassesses Japan's incidents, and revisits Korea's recent incidents. It focuses on the analysis of the hazards rather than the causes of human errors, the derivation of countermeasures, and their implementation. The preceding incidents and conclusions from Japanese experience are also re-analyzed. The Fukushima accident was an SBO due to the natural disaster such as earthquakes and a successive tsunami. Unlike the Fukushima accident, the Kori#1 incident itself was simple and restored without any loss and radioactive release. However, the fact that the incident was deliberately concealed led to massive distrust. Moreover, the continued violation of rules and organized concealment of the accident are serious signs of a new distorted type of human errors, blatantly revealing the cultural and fundamental weakness of the current organization. Result: We should learn from Japanese experiences who had taken pride in its safety technology and fairly high confidence in safety culture. Japan's first criticality accident in JCO facility splashed cold water on that confidence. It has turned out to be a typical case revealing the problems in the organization and safety culture. Since Japan has failed to gain lessons and countermeasure, the issue persists to the Fukushima incident. Conclusion: Safety culture is not a specific independent element, which makes it difficult to either evaluate it properly or establish countermeasures from the lessons. It may continue to expose similar human errors such as concealment of incident and manipulation of bad data. Application: Not only will this work establish the course of research for organization and safety culture, but this work will also contribute to the revitalization of Korea's nuclear industry from the disappointment after the export contract to UAE.

Capacity Comparison of Two Uplink OFDMA Systems Considering Synchronization Error among Multiple Users and Nonlinear Distortion of Amplifiers (사용자간 동기오차와 증폭기의 비선형 왜곡을 동시에 고려한 두 상향링크 OFDMA 기법의 채널용량 비교 분석)

  • Lee, Jin-Hui;Kim, Bong-Seok;Choi, Kwonhue
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39A no.5
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    • pp.258-270
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    • 2014
  • In this paper, we investigate channel capacity of two kinds of uplink OFDMA (Orthogonal Frequency Division Multiple Access) schemes, i.e. ZCZ (Zero Correlation Zone) code time-spread OFDMA and sparse SC-FDMA (Single Carrier Frequency Division Mmultiple Access) robust to access timing offset (TO) among multiple users. In order to reflect the practical condition, we consider not only access TO among multiple users but also peak to average power ratio (PAPR) which is one of hot issues of uplink OFDMA. In the case with access TO among multiple users, the amplified signal of users by power control might affect a severe interference to signals of other users. Meanwhile, amplified signal by considering distance between user and base station might be distorted due to the limit of amplifier and thus the performance might degrade. In order to achieve the maximum channel capacity, we investigate the combinations of transmit power so called ASF (adaptive scaling factor) by numerical simulations. We check that the channel capacity of the case with ASF increases compared to the case with considering only distance i.e. ASF=1. From the simulation results, In the case of high signal to noise ratio (SNR), ZCZ code time-spread OFDMA achieves higher channel capacity compared to sparse block SC-FDMA. On the other hand, in the case of low SNR, the sparse block SC-FDMA achieves better performance compared to ZCZ time-spread OFDMA.

Classification of Transport Vehicle Noise Events in Magnetotelluric Time Series Data in an Urban area Using Random Forest Techniques (Random Forest 기법을 이용한 도심지 MT 시계열 자료의 차량 잡음 분류)

  • Kwon, Hyoung-Seok;Ryu, Kyeongho;Sim, Ickhyeon;Lee, Choon-Ki;Oh, Seokhoon
    • Geophysics and Geophysical Exploration
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    • v.23 no.4
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    • pp.230-242
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    • 2020
  • We performed a magnetotelluric (MT) survey to delineate the geological structures below the depth of 20 km in the Gyeongju area where an earthquake with a magnitude of 5.8 occurred in September 2016. The measured MT data were severely distorted by electrical noise caused by subways, power lines, factories, houses, and farmlands, and by vehicle noise from passing trains and large trucks. Using machine-learning methods, we classified the MT time series data obtained near the railway and highway into two groups according to the inclusion of traffic noise. We applied three schemes, stochastic gradient descent, support vector machine, and random forest, to the time series data for the highspeed train noise. We formulated three datasets, Hx, Hy, and Hx & Hy, for the time series data of the large truck noise and applied the random forest method to each dataset. To evaluate the effect of removing the traffic noise, we compared the time series data, amplitude spectra, and apparent resistivity curves before and after removing the traffic noise from the time series data. We also examined the frequency range affected by traffic noise and whether artifact noise occurred during the traffic noise removal process as a result of the residual difference.

A Study on Stabilizing Container Terminal Market in Busan Port (부산항 항만하역시장 안정화 방안에 관한 연구)

  • Ryoo, Dong-Keun;Choi, Jin-Yi;Kim, Tae-Goun
    • Journal of Navigation and Port Research
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    • v.36 no.10
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    • pp.895-904
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    • 2012
  • Today, the competition for hub-port is getting fierce and the shipping liners have enjoyed the increased bargaining power over the terminal operators through the mergers & acquisitions (M&A) and strategic alliances. This result leads the competition among terminal operators to attract liner companies and cargoes in their terminals. In demand side, however, there is a limited container cargo volume to handle because of a steady growth of cargo traffic. While, in supply side, continuous development of port terminals increased more competition among ports or terminals for cargoes. In particular the terminal operating market of Busan port is distorted because of the cargo competition between Busan North-port and Newport. The main purpose of this study is to suggest the stabilization measures of container terminal operating market in Busan port through analysis of the terminal operation market structures and market survey analysis method. For stabilizing the container terminal market, this study suggests the improvement of the legal and institutional system such as improvement in determining and reporting system of stevedoring tariff, establishment of fair competition rules etc., the introduction of port pooling system and adoption of volume-linked terminal lease system with cargo volume ceiling system for each terminal operator.

Simulation and Evaluation of ECT Signals From MRPC Probe in Combo Calibration Standard Tube Using Electromagnetic Numerical Analysis (전자기 수치 해석을 이용한 Combo 표준 보정 시험편의 MRPC Probe 와전류 신호 모사 및 평가)

  • Yoo, Joo-Young;Song, Sung-Jin;Jung, Hee-Jun;Kong, Young-Bae
    • Journal of the Korean Society for Nondestructive Testing
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    • v.26 no.2
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    • pp.90-98
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    • 2006
  • Signals captured from a Combo calibration standard tube paly a crucial role in the evaluation of motorized rotating pancake coil (MRPC) probe signals from steam generator (SG) tubes in nuclear power plants (NPPs). Therefore, the Combo tube signals should be consistent and accurate. However, MRPC probe signals are very easily affected by various factors around the tubes so that they can be distorted in their amplitudes and phase angles which are the values specifically used in the evaluation. To overcome this problem, in this study, we explored possibility of simulation to be used as a practical calibration tool far the evaluation of real field signals. For this purpose, we investigated the characteristics of a MRPC probe and a Combo tube. And then using commercial software (VIC-3D) we simulated a set of calibration signals and compared to the experimental signals. From this comparison, we verified the accuracy of the simulated signals. Finally, we evaluated two defects using the simulated Combo tube signals, and the results were compared with those obtained using the actual field calibration signals.

A Study of the Nonstoichiometry and Physical Properties of the Nd1-xBaxFeO3-y System ($Nd_{1-x}Ba_xFeO_{3-y}$계의 비화학량론과 물리적 성질에 관한 연구)

  • Chang, Soon Ho;Yu, Gwang Hyeon;Kim, Seong Jin;Choe, Seung Cheol;Jang, Sun Ho
    • Journal of the Korean Chemical Society
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    • v.38 no.8
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    • pp.547-551
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    • 1994
  • A series of samples in the $Nd_{1-x}Ba_xFeO_{3-y}$ system has been prepared by heating the reactants to$1200^{\circ}C$ under an ambient atmosphere, and the solid solutions were identified by X-ray power diffraction analysis. The crystal systems of samples with x = 0.00 and 0.25 were found to be orthorhombic whose local symmetry is similiar to the distorted octahedral with orthoferrite type one, whereas those with x = 0.50 and 0.75 to be the cubic system. Since Fe ions in the solid solutions are a mixed valence state between $Fe^{3+}\;and\;Fe^{4+}$ ions, the nonstoichiometric chemical formulas could be determined from the mole ratio of $Fe^{4+}$ ion and oxygen vacacies. According to the Mossbauer spectroscopic analysis, the presence of 5-coordinated $FeO_5$ was evidenced only in the barium compounds along with $FeO_6,\;and\;FeO_4$, but not in the strontium and calcium compounds. The samples with x = 0.25 and 0.50 show a spectrum of superparamagnetism, which might be due to the formation of a domain of the ferromagnetic interaction between the $Fe^{3+}\;and\;Fe^{4+}$ ions. The electrical conductivities of all samples are within semiconducting range. Since the $Fe^{4+}$ ion acts as an electron acceptor level during the electron transfer between the Fe through intermediate $O^{2-}$ ions, the activation energy of the compounds decreases with the increment of $Fe^{4+}$ content.

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Magritte's drawings and Lacan's Subject theory: Gaze, Encounter with the world (마그리트 회화와 라캉의 주체론 - 응시, 세계와의 조우)

  • Baek, Jin-Hwa
    • The Journal of Art Theory & Practice
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    • no.5
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    • pp.7-24
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    • 2007
  • The subject is connected with a structure named "The Symbolic" to Lacan, but he denied that the subject is explained simply as a fruit of language and "Other". From his point of view, passing through Subject, De-formation and Crack over it is designated as foundation of generation and creation rather than our destined defect. It should not be understood that subject of "The Real" is a concept of the subject free itself from restraint of "The Symbolic". However, this does not mean he asserts "Subject" is something incapable of being controlled by the unknown power. The problem is that this autonomous existence meets inside of it with something "more than one's own self" by "circulating around itself" like a permanent star. This is the indication of a "stranger in the middle of my privacy", or "extimit$\'{e}$", a coined-word by Lacan. Perhaps "Subject" is nothing more than the name of distance of object which is "too hot" to come close, and of this circulating movement. It's because of this object that the real subject stands against generalization and the subject can't be restored to any place in symbolic order-even though it is empty. The part which is told from Lacan's structural theory, that is to say, an importance to Lacan is that his Subject theory is not suggested or denied as a manual structure. On the contrary, it is a study of the relationship between the settled symbol that included in "real subject which is a unconscious one" and the symbolic subject hold- that is a metaphysical subject in general meaning. In Lacan's enlarged concept of subject beyond symbolic reality, it is noticeable that it gives justifiability to the union of a medium of different nature in artistic expression. We can recognize that the unconscious world is a living space which enables it to be a "condition of human being", not something dark under the surface of water through Magritte's(Rene Magritte, 1898~1967) surrealistic works. In other words, Magritte's art secures a core dimension of human nature through a mysterious gap of conscious and settled space. Magritte's drawings often evokes strange and unsettling feelings in people who view his paintings. This is because routine objects are found in "unsuitable" places from which we usually find them in our everyday lives. "Reality" in Magritte's paintings makes it aware that it is a strained field of concealment and disclosure basically between truths, and we can learn that his behavior to overturn to paint in-visible things is finally an effort to restore the "real subject" to the viewer's reality. In other words, such reversion arouses a nostalgic desire for the objects existing in their original appearance as they are - natural condition that our gaze had not been distorted yet by anamorphic stains. - and the state when we are conscious of them normally. Such desire offers an opportunity for us to get out of mental depression rather than operates to us as an abnormal crack. It's a successive process of effort to search for lost subject and Paradise Lost facing up to reality of subject human that is to be a subject of world and life are ousted from their place by structure and authority of culture.

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Malaysia in 2016: Deepening Crisis and Losing Opportunities (말레이시아 2016: 위기의 지속과 기회의 상실)

  • HWANG, In Won;KIM, Hyung Jong
    • The Southeast Asian review
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    • v.27 no.1
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    • pp.131-161
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    • 2017
  • The political dynamics of Malaysia in 2016 should be seen as a process of losing an political opportunity mainly due to the split in opposition parties. The opportunity for political development was triggered by the ruling party in crisis. The ongoing 1Malaysia Development Berhad (1MDB) scandal involving the Prime Minister Najib Razak would have provided a favorable condition for the transfer of power. The opposition parties have however failed to utilize the chance that has arisen since the general elections in 2008 and 2013 due to the chronic problem of disunity. It can be seen as distortions of political development referring to a phenomenon in which a chance for regime change formed by the crisis in authoritarian regime is distorted by internal conflicts among opposition parties. Malaysia's political turmoil seemed to paralyze its economy while foreign policy was used as a tool for domestic politics. It was reported that the key economic indicator have worsen including exports and budget deficit. The ringgit had dropped to its lowest level since the economic crisis in 1997-98 which was mainly attributed to diminishing credibility on the Najib's administration. Najib's political struggle has also impeded Malaysia's foreign policy which has attempt to embrace China and the Rohingya issue. The chance to manage key risks would be diminished if oppositions' disunity continues as there is speculation that the general election could be held in 2017.

Antioxidant and Antiproliferating Effects of Prunus mume Vinegar Powder on Breast Cancer Cells (매실 식초 분말의 항산화 및 유방암 세포주 증식 억제 효과)

  • Park, Wool-Lim;Kim, Jeong-Ho;Heo, Ji-An;Won, Yeong-Seon;Seo, Kwon-Il
    • Journal of Life Science
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    • v.31 no.2
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    • pp.149-157
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    • 2021
  • Prunus mume Sieb. et Zucc is widely distributed in East Asia (Korea, Japan, and China), and its fruit is often used as a medication and food material. However, because most previous studies have only investigated the state of Prunus mume fruit extract, studies on the various ways of processing this extract are still needed to increase its utilization. In this study, we evaluated the physicochemical properties and physiological activities of spray-dried Prunus mume vinegar powder (SPP). The sugar content, pH, total acidity, and moisture content of the SPP were 8.90 °Brix, 3.19, 1.05%, and 3.07%, respectively. The SPP exhibited significantly high antioxidant activity in terms of DPPH radical scavenging activity (65.55%), reducing power (1.48), and hydrogen peroxide scavenging activity (48.07%). In addition, the SPP remarkably decreased the cell viability of human breast MDA-MB-231 and human skin cancer SK-MEL-28 in a dose-dependent manner. The morphological results of the treatment of MDA-MB-231 cells with SPP were distorted, shrunken cell masses. Furthermore, apoptotic bodies and nuclear condensation formed in the SPP-treated MDA-MB-231 cells. The total polyphenol and flavonoid contents of the SPP were 59.58 ㎍/g (gallic acid equivalent) and 57.56 ㎍/g (quercetin equivalent). The results of this study indicate that SPP, which has antioxidant activity and anticancer effects, can be useful in the development of natural medicines and functional food ingredients.

Reading Luces de Bohemia with Carnivalism (카니발리즘으로 읽는 『보헤미아의 빛』)

  • Kim, Seon-Uk
    • Iberoamérica
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    • v.21 no.2
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    • pp.25-52
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    • 2019
  • Esperpento denotes a literary style in Spanish literature first established by Spanish author Ramón María del Valle Inclán that uses distorted descriptions of reality in order to criticize society. And esperpento's narrative strategy is similar in many ways to Mikhail Bakhtin's carnivalism. Especially Valle Inclán's first esperpentic theatre, Luces de Bohemia contained various carnivalistic elements of Bakhtin. The various techniques of Valle Inclán's esperpento used in Luces de Bohemia can be explained by Bachchin's carnivalist techniques. Therefore, this paper aims to re-examine the esperpentic techniques in Luces de Bohemia of Valle Inclán in terms of Bakhchin's carnivalism. Because the esperpentic tecniques of this play pursue the subversion of power or authority through the carnivalistic aspects such as polyphony, subversion of seriousness, parody, grotesque realism, plaza, ambivalence, anomalous structure of space, time and plot, etc. Esperpento and carnivalism serve as a tool to interpret the social reality, beyond criticism and satire of Spanish society. The characters act passively on all the external factors that determine human destiny, rather than actively carving their own destiny like the classic heroes. Modern man cannot defy or control the external situation of the modern civilization. So they are tragic. In this situation, the protagonist of the tragedy who challenges reality disappears and a puppet figure like Max Estrella, the protagonist of the Luces de Bohemia, takes his place on a satirical level. This is the satire and the true meaning of carnivalistic humor that Valle Inclán tried in his play.