• Title/Summary/Keyword: exchanges

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Crystal Structures of Zeolite X Exchanged by Two Different Cations. Structures of Cd32Cs28-X and Cd28Rb36-X (X=Si100Al92O384)

  • Jeong, Gyoung-Hwa;Kim, Yang
    • Bulletin of the Korean Chemical Society
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    • v.23 no.8
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    • pp.1121-1126
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    • 2002
  • Two anhydrous crystal structures of fully dehydrated Cd2+ - and Cs+ -exchanged zeolite X, Cd32Cs28Si100Al92O384 (Cd32Cs28-X: a = 24.828(11) $\AA)$ and fully dehydrated Cd,sup>2+ - and Rb+ -exchanged zeolite X, Cd28Rb36Si100Al92O384 (Cd28Rb36-X: a = 24.794(2) $\AA$), have been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd3 at $21(1)^{\circ}C.$ The structures were refined to the final error indices, R1 = 0.058 and R2 = 0.065 with 637 reflections for Cd32Cs28-X and R1 = 0.086 and R2 = 0.113 with 521 reflections for Cd28Rb36-X for which I > $3\sigma(I)$. In the structure of Cd,sub>32Cs28-X, 16 Cd2+ ions fill the octahedral sites I at the centers of the double six rings (Cd-O = $2.358(8)\AA$ and O-Cd-O = $90.8(3)^{\circ}$ ). The remaining 16 Cd2+ ions occupy site II (Cd-O = $2.194(8)\AA$ and O-Cd-O = $119.7(4)^{\circ})$ and six Cs+ ions occupy site II opposite to the single six-rings in the supercage; each is $2.322\AA$ from the plane of three oxygens (Cs-O = 3.193(13) and O-Cs-O = $73.0(2)^{\circ}).$ Aboutten Cs+ ions are found at site II', $1.974\AA$ into the sodalite cavity from their three oxygen plane (Cs-O = $2.947(8)\AA$ and O-Cs-O = $80.2(3)^{\circ}).$ The remaining 12 Cs+ ions are distributed over site III' (Cs-O = 3.143(9) and O-Cs-O= $59.1(2)^{\circ})$. In the structure of Cd28Rb36-X, 16 Cd2+ ions fill the octahedral sites I at the center of the double-sixrings (Cd-O = 2.349(15) and O-Cd-O = $91.3(5)^{\circ}$ ). Another 12 Cd2+ ions occupy two different II sites (Cd-O = $2.171(18)/2.269(17)\AA$ and O-Cd-O = $119.7(7)/113.2(7)^{\circ}).$ Fifteen Rb+ ions occupy site II (Rb-O = $2.707(17)\AA$ and O-Rb-O = $87.8(5)^{\circ}).$ The remaining 21 Rb+ ions are distributed over site III' (Rb-O = $3.001(16)\AA$ and O-Rb-O = $60.7(4)^{\circ})$. It appears that the smaller and more highly charged Cd2+ ions prefer sites I and Ⅱ in that order, and the larger Rb+ and Cs+ ions, which are less able to balance the anionic charge of the zeolite framework, occupy sites II and II' with the remainder going to the least suitable site in the structure, site III'.The maximum Cs+ and Rb+ ion exchanges were 30% and 39%, respectively. Because these cations are too largeto enter the small cavities and their charge distributions may be unfavorable, cation-sieve effects might appear.

Branding a Place through Cultural Heritage: The Case Study of in Yunnan, China (문화유산 자원을 활용한 장소브랜딩: 중국 운남의 <인상리장>을 사례로)

  • Song, Jung Eun;Lee, Byung-min
    • Journal of the Economic Geographical Society of Korea
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    • v.19 no.2
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    • pp.189-208
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    • 2016
  • This research aims to discuss the impact of on regional development as a place brand and glocal heritage. Based on understanding of the changes and influences of local heritages in the globalization era as a key component of place branding, this study explores how is used to develop a place branding strategy for Lijiang. The research methods are both a literature review and a field research related to Lijiang and its culture. Also, the resources from news, internet, and YouTube are used to analyze the impact of . The performance has been attracting tourists from both Chineses and foreigners and contributed to increase the economic profits of local tourism industry as one of the representative identities of Lijiang. Also, in the process of preservation and recreation of cultural heritages of Lijiang such as , the participation of local residents and on-going interactions between the residents and global tourists highly influence on a transition from place marketing to place branding. By applying local cultural heritages to place branding strategies, the regional values of Lijiang strengthen its place identity from a place of preserving a minority's heritage to that of flourishing cultural exchanges and hybridization from the world.

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A Study on the Possibility of Domestic Dance Film's Development - Focusing on 'Seoul Dance Film Festival' and 'Dance Film Project' (국내 무용영화의 발전 가능성 연구 - '서울무용영화제'와 '댄스필름 프로젝트'를 중심으로)

  • LEE, Eunjoo;CHUNG, Euisook
    • Trans-
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    • v.4
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    • pp.37-63
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    • 2018
  • Dance films, which started together as a combination of dance and video technology, have evolved into a new genre. Overseas, from early 1950s, experimental dance films have been produced and the dance film association is organized along with many dance film festivals are being held. However, it has not been long since the perception and creativity of the genre of dance films in Korea. Under these circumstances, holding of the 'Seoul Dance Film Festival' and experimental approaches by 'Dance Film Project' are important for the development of domestic dance films. Therefore, this paper explores the concept and development of dance films, the status and features of various overseas dance film festivals and the 'Seoul Dance Film Festival'. This paper also explores the roll and function of 'Seoul Dance Film Festival' and 'Dance Film Project', and their expected benefit along with possibilities of prosperity of domestic dance film. 'Dance Film Project' is the educational and experimental venue for producing of dance films, and the 'Seoul Dance Film Festival' is a platform for producing dance film makers, show of works, dialogue with audiences, international exchanges, and distributions. The dance film festival embodies the value of the past and current flow of the dance film and is intrinsic to the existence of a live content that can be predicted the future aspect of its roll. The two groups mutual growth and development are expected to play a positive role in the development of domestic dance films.

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Biogeochemical Reactions in Hyporheic Zone as an Ecological Hotspot in Natural Streams (자연 하천의 생태학적 중요 지점으로서 지표수-지하수 혼합대의 생지화학적 기작)

  • Kim, Young-Joo;Kang, Ho-Jeong
    • Journal of Wetlands Research
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    • v.11 no.1
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    • pp.123-130
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    • 2009
  • Hyporheic zone is an area where hydraulic exchanges occur between surface water and ground water. Such transient area is anticipated to facilitate diverse biogeochemical reactions by providing habitats for various microorganism. However, only a few data are available about microbial properties in hyporheic zone, which would be important in better understanding of biogeochemical reactions in whole streams. The study site is Naesung stream, located in the north Kyoung-Sang Province, of which sediment is sandy with little anthropogenic impacts. Soil samples were collected from a transect placed perpendicular to stream flow. The transect includes upland fringe area dominated by Phragmites japonica, bare soil, and soil adjacent to water. In addition, soil samples were also collected from downwelling and upwelling areas in hyporheic zone within the main channel. Soils were collected from 3 depth in each area, and water content, pH, and DOC were measured. Various microbial properties including extracellular enzyme activities ($\beta$-glucosidase, N-acetylglucosaminidase, phosphatase and arylsulfatase), and microbial community structure using T-RFLP were also determined. The results exhibited a positive correlation between water content and DOC, and between extracellular enzyme activities and DOC. Distinctive patterns were observed in soils adjacent to water and hyporheic zone compared with other soils. Overall results of study provided basic information about microbial properties of hyporheic zone, which appeared to be discernable from other locations in the stream corridor.

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Changes in 3-Butenyl Isothiocyanate and Total Glucosinolates of Seeds and Young Seedlings during Growth of Korean Chinese Cabbages (배추 종자 및 어린 싹의 성장 시기에 따른 3-butenyl isothiocyanate 및 total glucosinolates 함량 변화)

  • 김연경;김건희
    • Food Science and Preservation
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    • v.10 no.3
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    • pp.365-369
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    • 2003
  • The main objective of this study was to investigate the pattern of glucosinolates, in terms of 3-butenyl isothiocyanate, and total glucosinolates, in different parts of young seedlings and seeds in Korean Chinese cabbages. For determination of glucosinolates, 55 days and Winter pride cultivars of Korean Chinese cabbages seeds and different parts of 1, 3, 5, and 7-day-old seedlings were used for analytical sample preparation provided with an anion exchanges column, and measured by GC and UV-visible Spectrophotometer. The concentration of 3-butenyl ITC was higher in the cotyledon and the hypocotyl parts of 55 days cultivar seedling than those of Winter Pride cultivar. In the cotyledon parts of Winter pride cultivar seedling, 3-butenyl ITC amount was increase to 3-day-old seedling and then reduced. The cotyledon of 55 days cultivar contained the highest concentration of total glucosinolates while those were increased in the hypocotyl and decreased in the root. The level of total glucosinolates was increased to 5-day-old seedling and then decreased in the cotyledon and the hypocotyl parts of seedling in Winter pride cultivar. There was no significant difference of total glucosinolates in the root part. In the seeds, 55 days cultivar concentration was higher than Winter pride cultivar both of 3-butenyl ITC and total glucosinolates. In our study, the levels of 3-butenyl ITC and total glucosinolates depended on cultivars, growth stages, and parts in Korean Chinese cabbage.

A Proxy Mobile IP based Fast Layer-3 Handover scheme for Mobile WiMAX based Wireless Mesh Networks (Mobile WiMAX 기반의 무선 메쉬 네트워크를 위한 Proxy Mobile IP 기반의 고속 3계층 핸드오버 방안)

  • Kim, Min;Kim, Jong-Min;Kim, Hwa-Sung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.8B
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    • pp.1129-1140
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    • 2010
  • Wireless mesh networks have been widely studied as the next generation technology to solve the problems of conventional wireless networks. Particularly, Mobile WiMAX based wireless mesh networks are noticed due to many advantages. Mobile WiMAX standard provides two kinds of layer-3 handover schemes: Mobile IP and Proxy Mobile IP based handover schemes. MIP based handover scheme has a problem in that it incurs the long handover latency because mobile nodes generate a lot of handover messages. On the other hand, PMIP based handover scheme decreases the handover latency by reducing the number of handover messages, because mobile nodes do not participate in handover procedure. Therefore, layer-3 handover for Mobile WiMAX should be designed based on PMIP. However, conventional PMIP based handover still has latency overhead, because of many message exchanges between PBU and PBA after completing the layer-2 handover. Hence, in this paper, we propose a fast layer-3 handover scheme that achieves the lower handover latency for Mobile WiMAX based wireless mesh networks. Proposed scheme has advantages in terms of handover latency. Simulation results show that proposed scheme achieves low handover latency during the layer-3 handover.

A Test on Price Volatility of CO2 Emission Trading Permits focusing on ECX and CCX (탄소배출권 가격변동성의 가설검정 - ECX와 CCX를 중심으로)

  • Lho, Sangwhan
    • Journal of Environmental Policy
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    • v.10 no.2
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    • pp.45-60
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    • 2011
  • An aim of this paper is to test four hypotheses on price volatility in the $CO_2$ emission markets focusing on European Climate Exchange(ECX) in the EU Emission Trading Schemes(EU ETS) and Chicago Climate Exchange(CCX). I expect that, due to an influx of market information, a differently designed exchange market would bring a different price volatility, and various types of emission permits in the same exchange market would result in the same effects on the price volatility. Major findings are that the price volatility is same regardless of the types of emission exchange markets and emission permits comparing the rate of returns. However, comparing the GARCH variance, the volatility between ECX EUAs and CCX-CFIs and the volatility between EUAs(CERs) futures and daily futures are different with the exception of the volatility between EUAs futures and CERs futures. In conclusion, the price volatility depends on the types of exchanges and the types of emission permits.

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Identification and Functional Analysis of the putAP Genes Encoding Vibrio vulnificus Proline Dehydrogenase and Proline Permease

  • Kim, Hye-Jin;Lee, Jeong-Hyun;Rhee, Jee-Eun;Jeong, Hye-Sook;Choi, Hyun-Kyung;Chung, Hee-Jong;Ryu, Sang-Ryeol;Choi, Sang-Ho
    • Journal of Microbiology and Biotechnology
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    • v.12 no.2
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    • pp.318-326
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    • 2002
  • The pathogenic marine bacterium Vibrio vulnificus is the causative agent of food-borne diseases such as life-threatening septicemia. To better understand this organism's strategies to survive osmotic stress, a mutant that was more sensitive to high osmolarity was screened from a library of mutants constructed by a random transposon mutagenesis. By a transposon-tagging method, putAP genes encoding a proline dehydrogenase and a proline permease were identified and cloned from V. vulnificus. The amino acid sequences deduced from nucleotide sequences of putAP from V. vulnificus were 38 to $59\%$ similar to those of PutA and PutP reported from other Enterobacteriaceae. Functions of putAP genes were assessed by the construction of mutants, whose putAP genes were inactivated by allelic exchanges. When proline as the sole carbon or nitrogen source was used, the putA mutant was not able to grow to the substantial level, revealing the proline dehydrogenase is the only enzyme for metabolic conversion of proline into other amino acids. Although the growth rate of the putP mutant on proline as the sole carbon or nitrogen source was significantly reduced, the mutant still grew. This indicated that at least one more proline permease is produced by V. vulnificus. The putP mutant decreased approximately $2-log_10$ CFU/ml after a hyperosmotic challenge, while the parent strain decreased approximately $l-log_10$ CFU/ml. This result suggests that the gene product of putP contributes to the osmotic tolerance of V. vulnificus.

A Comparative Study on the Civil Aviation Law between South and North Korea. (남.북한 항공법 비교연구)

  • Kim, Maeng-Sern;Lee, Si-Hwang
    • The Korean Journal of Air & Space Law and Policy
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    • v.21 no.2
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    • pp.97-121
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    • 2006
  • Inter-Korean exchanges using civil aviation has been continuing since the temporary direct air route from Pyongyang to Seoul was opened on June 15th, 2000 for the summit meeting with North Korea. In this paper, I analyze the North Korea Aviation law by focusing on the differences with South Korean Aviation law. While South Korean Aviation law is modeled on the Pandect system, North Korean Aviation law can only be understood by looking at North Korea's socialist ideology. Therefore, North Korean Aviation law has some expressions which can hardly be understood. With respect to the source of aviation law, both South and North Korea are in compliance with the Convention on International Civil Aviation (Signed at Chicago, on 7 December, 1944). Thus, they established the aviation law based on the standards and recommendations provided by ICAO. For this reason, they have similar legal systems and composition. From this analysis, a few differences are also derived regarding aircraft ownership, airports, airline liability, aircraft accident investigation organization and aviation insurance. It is important to note that this paper has a particular limitation. Not only is the information about North Korean law very limited, but North Korea also does not provide easy access to its national legal codes. This paper describes the legal comparison of South and North Korea by focusing on the formation and framework of North Korean aviation law.

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Performance Analysis of Routing Protocols for WLAN Mesh Networks (WLAN Mesh 망을 위한 라우팅 기법의 성능 분석)

  • Park, Jae-Sung;Lim, Yu-Jin;Ahn, Sang-Hyun
    • The KIPS Transactions:PartC
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    • v.14C no.5
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    • pp.417-424
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    • 2007
  • Mesh networks using WLAN technology have been paid attention as a key wireless access technology. However, many technical issues still exist for its successful deployment. One of those issues is the routing problem that addresses the path setup through a WLAN mesh network for the data exchanges between a station and a wired network. Since the characteristics of a WLAN mesh network can be very dynamic, the use of single routing protocol would not fit for all environments whether it is reactive or proactive. Therefore, it is required to develop an adaptive routing protocol that modifies itself according to the changes in the network parameters. As a logical first step for the development, an analytical model considering all the dynamic features of a WLAN mesh network is required to evaluate the performance of a reactive and a proactive routing scheme. In this paper, we propose an analytical model that makes us scrutinize the impact of the network and station parameters on the performance of each routing protocol. Our model includes the size of a mesh network, the density of stations, mobility of stations. and the duration of network topology change. We applied our model to the AODV that is a representative reactive routing protocol and DSDV that is a representative proactive routing protocol to analyze the tradeoff between AODV and DSDV in dynamic network environments. Our model is expected to help developing an adaptive routing protocol for a WLAN mesh network.