• Title/Summary/Keyword: Counter sustain

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Analysis on the Discharge Characteristics of AC Plasma Display Panel with Counter Sustain Electrodes (교류형 플라즈마 표시기의 신 대향형 구조에 대한 방전 특성 분석)

  • Bae, Hyun-Sook;Whang, Ki-Woong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.9
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    • pp.1579-1583
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    • 2008
  • We proposed the new structure of ac plasma display panel(PDP) to improve the luminous efficacy and driving voltage characteristics. Through two-dimensional numerical simulations, we analyzed the effects of new counter discharge type, which consists of counter sustain electrodes and auxiliary electrodes. Generally, an advantage of AC PDP with the counter sustain electrodes has been known for the driving characteristics of the low voltage. In this work, the new counter structure using the ignition discharge by the auxiliary pulse applied to the address electrode showed the result of the increased luminous efficacy. The short gap discharge between two auxiliary electrodes on the front plate could intensity the long gap discharge between counter electrodes. The reliability of simulation result could be confirmed by the experimental result in the test panel.

Discharge Characteristic of Microdischarge Cell with Counter Sustain Electrodes and Twin Auxiliary Electrodes

  • Hashimoto, M.;OH, J.S.;Tachibana, K.;Asai, H.;Kikuchi, N.;Sakamoto, S.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.886-889
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    • 2006
  • Twin Auxiliary Electrodes were applied to the counter sustain electrode structure plasma display panels for the improvement of luminous efficiency. In advanced, we investigated the spatiotemporal behaviors of excited $Xe^{\ast\ast}(2p)$ atoms in that structure unit cell with various applied voltage conditions for the auxiliary electrodes. The near-IR emissions were observed by an ICCD camera combined with narrow band pass filter. As a partial result, the intensity of IR emissions and the response time were improved with the proposed twin auxiliary electrodes.

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Counter-Productive Countering-Violent-Extremism Initiatives: The Case of Malaysia

  • Kevin Fernandez
    • SUVANNABHUMI
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    • v.15 no.1
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    • pp.205-227
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    • 2023
  • This study seeks to examine how the West, particularly United States (US), influences the narratives about terrorism, radicalism, and combating violent extremism (CVE) in Muslim majority nations such as Malaysia. We contend that some local institutions and researchers in Malaysia may have assumed the Faustian bargain by agreeing with the Western narrative that Islam's teachings promote violence and extremism in order to meet the demands of survival, whether it be funding for everyday operations or meeting the demands of universities or research institutions to sustain themselves and meet their performance indicators. We conducted a systematic literature review (SLR) from 2001 to 2021 and used Foucauldian Critical Discourse Analysis (CDA) to understand the role of the US in purposefully supporting workshops and research activities of particular institutions with the intent to influence national discourse on securitization and prospective policy implications. More importantly, we wish to alert Malaysian policymakers to pay particular attention and scrutinize ongoing programs such as the "Building Community Resilience" as these may inadvertently foster Islamophobia.

Influence of Fuel concentration gradient on the Extinction Behavior in Buoyancy minimized Counterflow Diffusion Flame (부력을 최소화한 대향류 확산화염 소화거동에서 연료농도구배의 영향)

  • Park, Jin Wook;Park, Jeong;Yun, Jin-Han;Keel, Sang-In
    • 한국연소학회:학술대회논문집
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    • 2014.11a
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    • pp.379-381
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    • 2014
  • Influence of fuel concentration gradient was investigated near flame extinction limit in buoyancy-suppressed non-premixed counterflow flame with triple co-flow burner. The use of He curtain flow produced a microgravity level of $10^{-2}-10^{-3}g$ in He-diluted non-premixed counter triple co-flow flame experiments. Flame stability map was presented based on flame extinction and oscillation near extinction limit. The stability map via critical diluent mole fraction with global strain rate was represented by varying outer and inner He-diluted mole fractions. The flame extinction modes could be classified into five: an extinction through the shrinkage of the outmost edge flame forward the flame center with and without self-excitation, respectively ((I) and (II)), an extinction via the rapid expansion of a flame hole while the outmost edge flame is stationary (III), both the outermost and the center edge flames oscillate, and then a donut shaped flame is formed or the flame is entirely extinguished (IV), a shrinkage of the outermost edge flame without self-excitation followed by shrinking or sustain the inner flame (V).

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The Importance and Multifunctions of Korean Paddy Fields

  • Cho Young-Son;Lee Byeong-Jin;Choe Zhin-Ryong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.2
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    • pp.179-185
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    • 2006
  • The Ministry of Agriculture and Forestry announced in 2001 that the overall amount of paddy land set aside for rice will be cut down by 12% by 2005, decreasing from 1.08 million to 953,000 hectares. When evaluating the value of paddy rice systems, the multi-function of paddy systems in the monsoon climate is vital importance. The main functions of paddy rice systems are to conserve biodiversity and maintain sustainability. Some crucial environmental benefits of the paddy rice systems include: flood prevention, recharge of water resources, water purification, soil erosion and landslide prevention, soil purification, landscape preservation and air purification. The paddy rice systems in Korea, which are more diverse than upland crop systems, are known to be composed of 14 orders, 36 families and 134 species. The sustain ability of paddy rice production systems can never be overestimated. Rice is part of the culture and even the heart of spiritual life in the area under the monsoon climate. Therefore paddy rice systems should be preserved with the highest priority being the enhancement of the systems' multi-function. As an outlook to future research, the need of joint and interdisciplinary research projects between economists and natural scientists at inland as well as international levels were emphasized in establishing the development of counter-measure logic through actual proofed analysis.

Measurement of fast ion life time using neutron diagnostics and its application to the fast ion instability at ELM suppressed KSTAR plasma by RMP

  • Kwak, Jong-Gu;Woo, M.H.;Rhee, T.
    • Nuclear Engineering and Technology
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    • v.51 no.7
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    • pp.1860-1865
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    • 2019
  • The confinement degradation of the energetic particles during RMP would be a key issue in success of realizing the successful energy production using fusion plasma, because a 3.5 MeV energetic alpha particle should be able to sustain the burning plasma after the ignition. As KSTAR recent results indicate the generation of high-performance plasma(${\beta}_p{\sim}3$), the confinement of the energetic particles is also an important key aspect in neutral beam driven plasma. In general, the measured absolute value of the neutron intensity is generally used for to estimating the confinement time of energetic particles by comparing it with the theoretical value based on transport calculations. However, the availability of, but for its calculation process, many accurate diagnostic data of plasma parameters such as thermal and incident fast ion density, are essential to the calculation process. In this paper, the time evolution of the neutron signal from an He3 counter during the beam blank has permitted to facilitate the estimation of the slowing down time of energetic particles and the method is applied to investigate the fast ion effect on ELM suppressed KSTAR plasma which is heated by high energy deuterium neutral beams.

Improved RPV(reactive-power-variation) anti-islanding method for grid-connected three-phase PVPCS (3상 계통연계형 태양광 PCS의 단독운전검출을 위한 개선된 무효전력변동기법)

  • Lee, K.O.;Jung, Y.S.;So, J.H.;Yu, B.G.;Yu, G.J.;Choi, J.Y.;Choy, I.
    • Proceedings of the KIEE Conference
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    • 2006.07b
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    • pp.1159-1160
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    • 2006
  • As the grid-connected photovoltaic power conditioning systems (PVPCS) are installed in many residential areas, this has raised potential problems of network protection on electrical power system. One of the numerous problems is an Island phenomenon. There has been an argument that because the probability of islanding is extremely low it may be a non-issue in practice. However, there are three counter-arguments: First, the low probability of islanding is based on the assumption of 100% power matching between the PVPCS and the islanded local loads. In fact, an island can be easily formed even without 100% power matching (the power mismatch could be up to 30% if only traditional protections are used, e.g. under/over voltage/frequency). The 30% power-mismatch condition will drastically increase the islanding probability. Second, even with a larger power mismatch, the time for voltage or frequency to deviate sufficient to cause a trip, plus the time required to execute the trip (particularly if conventional switchgear is required to operate), can easily be greater than the typical re-close time on the distribution circuit. And, third, the low-probability argument is based on the study of PVPCS. Especially, if the output power of PVPCS equals to power consumption of local loads, it is very difficult for the PVPCS to sustain the voltage and frequency in an island. Unintentional islanding of PVPCS may result in power-quality issues, interference to grid-protection devices, equipment damage, and even personnel safety hazards. So the verification of anti-islanding performance is strongly needed. In this paper, the authors propose the improved RPV method through considering power quality and anti-islanding capacity of grid-connected three-phase PVPCS in IEEE Std 1547 ("Standard for Interconnecting Distributed Resources to Electric Power Systems"). And the simulation and experimental results are verified.

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The Role of the Sedimentary Deposits (silt line) from Rivers Flowing into the Sea in the Yellow Sea Maritime Boundary (강의 퇴적물과 황해 경계획정 적용가능성에 관한 연구)

  • Yang, Hee-Cheol
    • Ocean and Polar Research
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    • v.31 no.1
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    • pp.31-50
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    • 2009
  • The demarcation of Maritime Boundary is directly related to the expansion of jurisdiction and the securing of resources. Resource diplomacies of the three countries Korea, China and Japan represent a major task for the national administrations : to secure resources as well as to stablize and sustain resources for future national economies. At the sea area around Korea as well, countries are fiercely competing to secure resources and to expand jurisdiction. This is evidenced by the fact that various principles and logics which are beneficial to each own country are presented through international precedents, agreement between countries and the theories of the international law scholars. They say that the conclusion of demarcation of maritime boundary for the Yellow Sea would be easy from the point that there is no dispute related to island dominion in the waters of the Korean Peninsula especially the Yellow Sea, but still we need to have a strategic approach to this issue from the point that the factors used for claiming maritime boundaries may expand the waters of a country over much. For example, the continental shelf boundary in consideration of the distribution of sedimentary deposits in the Yellow Sea which is being raised by China began from the hypothesis that the inflow of sedimentary deposits to the Yellow Sea through the rivers of China represents absolute majority, but the results of the latest studies raised questions on the hypothesis. Especially, the studies done by Martin and Yang revealed that the inflow of sedimentary deposits to the Yellow Sea from the Yellow River is approximately less than 1% of total sedimentary deposits in the Yellow Sea, and also the result of analysis on the causes and counter policy measures on the environment of Bohai, China supports the reliability of the results of such studies. From a legal aspect, the sedimentary deposits of rivers which are claimed by China represent extremely weak ground for the claim for the title of the continental shelf. The siltline claimed by China seems to be based on the Article 76-4-(a)(i) of UNCLOS. This is, however, not the definition on the title of the continental shelf but it is only a technical formula to utilize in a case where a country desires to expand the continental shelf to over 200 nautical miles. Scientific and Technical Guidelines of the Commission on the Limits of the Continental Shelf also confirm this point through the Article 2.1.2 of the Guideline. The only case in which sedimentary deposits of rivers were referred to as concrete demarcation of maritime boundary was in the which was concluded in 1986 between India and Myanmar at the Andaman Sea. In the said case, India acknowledged the boundary up to the isobath of 200m which Myanmar claimed based on the sedimentary deposits of the Irrawaddy River. It has limits as a case for acknowledging the sedimentary deposits, however, because in fact India's acknowledgment was made in exchange for the condition that Myanmar gave up the dominion of two islands which they had been claiming from India up until that time.

Reactive Power Variation Method for Anti-islanding Using Digital Phase-Locked-Loop (DPLL을 이용한 능동적 단독운전방지를 위한 무효전력변동법)

  • Lee, Ki-Ok;Yu, Byung-Gu;Yu, Gwon-Jong;Choi, Ju-Yeop;Choy, Ick
    • Journal of the Korean Solar Energy Society
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    • v.28 no.2
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    • pp.64-69
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    • 2008
  • As the grid-connected photovoltaic power conditioning systems (PVPCS) are installed in many residential areas, these have raised potential problems of network protection on electrical power system. One of the numerous problems is an Islanding phenomenon. There has been an argument that it may be a non-issue in practice because the probability of islanding is extremely low. However, there are three counter-arguments: First, the low probability of islanding is based on the assumption of 100% power matching between the PVPCS and the islanded local loads. In fact, an islanding can be easily formed even without 100% power matching (the power mismatch could be up to 30% if only traditional protections are used, e.g. under/over voltage/frequency). The 30% power-mismatch condition will drastically increase the islanding probability. Second, even with a larger power mismatch, the time for voltage or frequency to deviate sufficiently to cause a trip, plus the time required to execute a trip (particularly if conventional switchgear is required to operate), can easily be greater than the typical re-close time on the distribution circuit. Third, the low-probability argument is based on the study of PVPCS. Especially, if the output power of PVPCS equals to power consumption of local loads, it is very difficult for the PVPCS to sustain the voltage and frequency in an islanding. Unintentional islanding of PVPCS may result in power-quality issues, interference to grid-protection devices, equipment damage, and even personnel safety hazards. Therefore the verification of anti-islanding performance is strongly needed. In this paper, improved RPV method is proposed through considering power quality and anti-islanding capacity of grid-connected single-phase PVPCS in IEEE Std 1547 ("Standard for Interconnecting Distributed Resources to Electric Power Systems"). And the simulation results are verified.