• Title/Summary/Keyword: $<_+$-stable

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An Updated Review of Recent Studies on Dimensionally Stable Anodes (DSA) (불용성 산화 전극(DSA)의 최신 연구 동향)

  • Park, Su-Ryeon;Park, Jin-Soo
    • Journal of the Korean Electrochemical Society
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    • v.23 no.1
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    • pp.1-10
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    • 2020
  • DSA (Dimensionally Stable Anode) electrodes are physically, thermally and electrochemically stable and are mainly Ti electrodes coated by Ru, Ir and Ta. DSA electrodes have been used in many industrial fields such as chlor-alkali, electrochemical water treatment, water electrolysis, etc. This review paper summarizes the study on the applications using DSA electrodes published in the recent 5 years. It suggests that the researches are intensively required on effective screening of electrodes materials, optimal designing of electrode structures and economical manufacturing of large area electrodes. It is expected that these studies will contribute to the further research and development on advanced DSA electrodes. In addition, the enhancement of DSA electrodes significantly leads to expand the type of the application using electrochemical processes in industry.

The Origin and Biogeochemistry of Organic Matter in Surface Sediments of Lake Shihwa and Lake Hwaong

  • Won, Eun-Ji;Cho, Hyen-Goo;Shin, Kyung-Hoon
    • Ocean Science Journal
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    • v.42 no.4
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    • pp.223-230
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    • 2007
  • To understand the origin and biogeochemistry of the organic matter in surface sediments of Lake Shihwa and Lake Hwaong, organic nitrogen, inorganic nitrogen, labile organic carbon, and residual organic carbon contents as well as stable isotope ratios for carbon and nitrogen were determined by KOBr-KOH treatment. Ratios of organic carbon to organic nitrogen $(C_{org}/N_{org})$ (mean = 24) were much higher than ratios of organic carbon to total nitrogen $(C_{org}/N_{tot})$ (mean= 12), indicating the presence of significant amounts of inorganic nitrogen in the surface sediments of both lakes. Stable isotope ratios for organic nitrogen were, on average, $5.2\%_{\circ}$ heavier than ratios of inorganic nitrogen in Lake Shihwa, but those same ratios were comparable in Lake Hwaong. This might be due to differences in the origin or the degree of degradation of sedimentary organic matter between the two lakes. In addition, stable isotope ratios for labile organic carbon were, on average, $1.4\%_{\circ}$ heavier than those for residual organic carbon, reflecting the preferential oxidation of $^{13}C$-enriched organic matter. The present study demonstrates that KOBr-KOH treatment of sedimentary organic matter can provide valuable information for understanding the origin and degradation state of organic matter in marine and brackish sediments. This also suggests that the ratio of $(C_{org}/N_{org})$ and stable isotope ratios for organic nitrogen can be used as indexes of the degree of degradation of organic matter.

An Efficient Logging Scheme based on Lazy Release Consistent Model for Distributed Shared Memory System (잠금 해제 지연 일관성 모델을 기반으로 하는 분산 공유 메모리 시스템에서의 효과적인 로깅기법)

  • Park, Tae-Soon;Yeom, Heon-Yeong
    • Journal of KIISE:Computer Systems and Theory
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    • v.27 no.2
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    • pp.188-199
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    • 2000
  • This paper presents an efficient stable logging scheme for the distributed shared memory system based on the lazy release consistent memory model. In the proposed scheme, inter-process dependency is traced and stable logging is performed when the dependency relation between processes actually happens. With the dependency tracking, the proposed scheme requires much less frequency of stable logging, comparing with the previous schemes in which stable logging is performed whenever any information transfer happens between processes. Also, in the proposed scheme, every data item accessed by a process is not logged, but only the access information is logged in the stable storage. For the recovery from a failure, the correct version of the accessed data items can be effectively traced by using the logged access information. As a result, the amount of logged information is also reduced.

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Comparison of the Upper and Lower Trapezius and Serratus Anterior during Push-up Plus Exercise with and without an Elastic Shoulder Band

  • Kim, Kyeong-Jin;Woo, Hye-Jin;Hong, Yu-Jeong;Hwang, Young-In
    • Journal of the Korean Society of Physical Medicine
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    • v.13 no.3
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    • pp.75-80
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    • 2018
  • PURPOSE: Scapular stability is very important to arm function during activities of daily living. The push-up plus exercise is commonly used to stabilize the shoulder muscles. In the present study, we designed an elastic shoulder band (ESB) that could be used with the push-up plus exercise and studied muscle activities of the serratus anterior (SA) and the lower and the upper trapezius (LT and UT) on stable and unstable support. METHODS: Fifteen healthy people participated in this study. Three muscles were investigated using surface EMG with and without the ESB on stable and unstable support. All subjects performed each trial three times for 7 seconds per set and rested for 30 seconds. Repeated one-way ANOVA was used for statistical analyses. RESULTS: The EMG activity of the SA was significantly different during the push-up plus exercise on stable support with the ESB compared with that on unstable support without the ESB (p<.05). However, there were no differences in the activities of UT and LT on stable and unstable support (p>.05). CONCLUSION: The ESB was effective for the activity of SA during the push-up plus exercise on stable support; therefore, it has the potential for use by people during push-up plus exercises. However, further studies are required to investigate the rehabilitation tools for patients with shoulder instability.

Studies on Stability of Red Color Pigments from the Korean Lithospermum erythrorhizon (한국산 자초 적색소의 안정성에 관한 연구)

  • 이제헌;오문헌;이희봉
    • The Korean Journal of Food And Nutrition
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    • v.13 no.4
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    • pp.383-389
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    • 2000
  • Stabilities to heat, pH, light were investigated about isolated red color pigment from the Korean Lithospermum erythrorhizon. The extracted pigment, acetylshikonin was stable heating at 40∼80$\^{C}$ for 1∼2 hours, hut it was specially unstable on the storage above 55$\^{C}$. The extracted pigment, acetylshikonin was stable on the sunlight under the red and green filters but unstable under the yellow and blue filters. The extracted pigment, acetylshikonin was stable under the pH of 4∼8 but unstable under the pH above 10. The extracted pigment, acetylshikonin was stable under the KCl and NaCl at concentration of 10$\^$-1/Mole. The pigment was very unstable under the CaCl$_2$, FeCl$_3$, CoCl$_2$, AlCl$_3$ and MnCl$_2$ at concentration of 10$\^$-1/Mole. The red pigment, acetylshikonin was stable under citric acid and acetic acid at concentration of 1 Mole. Especially, acetic acid was effective for the stability of the pigment.

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Stable Isotope Studies for Constraining Water and Carbon Cycles in Terrestrial Ecosystems: A Review (안정 동위원소를 이용한 육상 생태계의 물과 탄소의 순환 연구: 재검토)

  • Lee Dongho
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.7 no.1
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    • pp.15-27
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    • 2005
  • The water and carbon cycles in terrestrial ecosystems are the essential database for better understanding of the causes and the current processes of climate change and for the prediction of its future change. CarboKorea and HydroKorea are dedicated research efforts to develop technologies to quantitatively interpret and forecast carbon/water cycles in typical landscapes of Korea. For this, stable isotope studies have been launched to genetically partition various components of carbon/water cycles in terrestrial ecosystems. From stable isotope studies, practical deliverables such as evaporation, transpiration and gross primary productivity (GPP) can be provided at scales from tower (footprint) to large watersheds. Such reliable field-based information will form an important database to be used for validation of the results from various eco-hydrological models and satellite image analysis which constitute main components of Carbo/HydroKorea project. Stable isotope studies, together with other relevant researches, will contribute to derive quantitative interpretation of carbon/water cycles in terrestrial ecosystems and support Carbo/HydroKorea to become a leading research infrastructure to answer pending scientific and socio-economic questions in relation to global changes.

ON THE STABILITY OF A FIXED POINT ALGEBRA C*(E)γ OF A GAUGE ACTION ON A GRAPH C*-ALGEBRA

  • Jeong, Ja-A.
    • Journal of the Korean Mathematical Society
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    • v.46 no.3
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    • pp.657-673
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    • 2009
  • The fixed point algebra $C^*(E)^{\gamma}$ of a gauge action $\gamma$ on a graph $C^*$-algebra $C^*(E)$ and its AF subalgebras $C^*(E)^{\gamma}_{\upsilon}$ associated to each vertex v do play an important role for the study of dynamical properties of $C^*(E)$. In this paper, we consider the stability of $C^*(E)^{\gamma}$ (an AF algebra is either stable or equipped with a (nonzero bounded) trace). It is known that $C^*(E)^{\gamma}$ is stably isomorphic to a graph $C^*$-algebra $C^*(E_{\mathbb{Z}}\;{\times}\;E)$ which we observe being stable. We first give an explicit isomorphism from $C^*(E)^{\gamma}$ to a full hereditary $C^*$-subalgebra of $C^*(E_{\mathbb{N}}\;{\times}\;E)({\subset}\;C^*(E_{\mathbb{Z}}\;{\times}\;E))$ and then show that $C^*(E_{\mathbb{N}}\;{\times}\;E)$ is stable whenever $C^*(E)^{\gamma}$ is so. Thus $C^*(E)^{\gamma}$ cannot be stable if $C^*(E_{\mathbb{N}}\;{\times}\;E)$ admits a trace. It is shown that this is the case if the vertex matrix of E has an eigenvector with an eigenvalue $\lambda$ > 1. The AF algebras $C^*(E)^{\gamma}_{\upsilon}$ are shown to be nonstable whenever E is irreducible. Several examples are discussed.

Source Tracking of Particular Matters using Stable Isotope Analysis and Water Quality Characteristics in Gulpo and Anyang Stream, Han-River (한강수계 굴포천과 안양천에서 안정동위원소와 수질 특성을 이용한 입자성 물질의 기원 추적)

  • Hong, Jung-Ki;Im, Jong Kwon;Son, Ju Yeon;Noh, Hye-Ran;Yu, Soon-Ju;Lee, Bo-Mi
    • Journal of Korean Society on Water Environment
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    • v.36 no.2
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    • pp.116-124
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    • 2020
  • This study aims to identify the characteristics of organic matter and pollutant sources using water quality and stable isotope ratios (δ15N, δ13C) of the two inflow tributaries (Gulpo (GP) and Anyang (AY) streams). Water samples were analyzed in June and September 2018, and the results showed that the concentrations of nutrients, such as TN and NO3-N, were increased at GP4, which is located at the downstream of sewage treatment facilities(STFs). TOC and TN ratios showed a strong positive correlation (R2 = 0.77, p<0.01) at all points except for GP4. The results of GP's stable isotope ratio analysis do not appear to be a constant cluster compared to AY because GPs with large amounts of pollutants from the industry (metal processing companies, etc.) have less tributary, shorter waterway and significantly different external sources. This could be attributed to different sources of external inflow despite its smaller number of tributaries and shorter waterways than AY. In the first half of the year, the δ155N of GP4 was affected by discharge of STFs, while AY3 seemed to have an influence of tributary than the discharge of STFs. Consequently, using water quality, stable isotope ratio and C/N, the sources of contamination in two streams with different contaminants were identified and origin was estimated.

Implementation of Power Line Communication System Appling High-Order Stable Notch filter Scheme (High-Order Stable Notch Filter 기법을 적용한 전력선 통신 시스템 구현)

  • Kim, Kyung-Seok;Nam, Yun-Ho;Kim, Joo-Seok
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.1C
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    • pp.28-36
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    • 2011
  • As Power Line has been already installed over 60% of a residential area all over the world, Broadband Service has been possible using high-speed PLC(Power Line Communication) without new access line installed for Internet access. Because of such reason, PLC is researched as the most suitable service for Last Mile Solution. But, Power Line is designed for transmitting electric power, so peripheral Wireless Communication System is affected by a leak of electric wave. In this paper, we propose a High Performance Notch Filter algorithm in comparison with a existing notch filter for reduction of interference between existing Wireless Communication Service and Power Line Service. In addition, we implement the Notch Filter emulator appling a High Performance Notch Filter and using a embedded board.

Analysis of Saltwater Intrusion Effects into Coastal Aquifers in Korea considering Climate Change Effects (기후변화의 영향을 고려한 한반도 해안지역 대수층의 해수침투 영향 분석)

  • Yang, Jeong-Seok;Nam, Jae-Joon;Park, In-Bo;Kim, Sangdan
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.1B
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    • pp.71-85
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    • 2011
  • Saltwater intrusion effects of coastal aquifers in Korea peninsula were analyzed through trend analysis with groundwater level, seawater level, seawater temperature, and electrical resistivity(EC) data sets. Groundwater level and EC data sets from 27 coastal regions were collected and analyzed. Groundwater level was stable for all the regions however EC data showed stable or changing trends (9 increasing, 10 stable, and 8 decreasing regions). Seawater temperature was collected and analyzed for 14 regions and they are increasing for most regions (12 increasing and 2 stable regions). Seawater level was also collected and analyzed for 24 regions and is rising for most regions (18 rising, 3 stable, and 3 falling regions). Especially, west cost regions have stronger increasing tendencies of seawater level, seawater temperature, and EC than eastern and southern coastal regions. Therefore the saltwater intrusion problem can be serious for west cost regions in Korea peninsula and it is necessary to establish a plan to minimize the damages from saltwater intrusion.