• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.757-763
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• 1999

The metal specificity of D-xylose isomerase from Streptomyces rubiginosus was examined by site-directed mutagenesis. The activation constants for metal ion ($Mg^{2+},{\;}Mn^{2+},{\;}or{\;}Co^{2+}$) of wild-type and mutant enzymes were determined by titrating the metal ion-free enzyme with $Mg^{2+},{\;}Mn^{2+},{\;}and{\;}Co^{2+}$, respectively. Substitutions of amino acids either on coordinated or around the M2 site (His-22O, Asn-185, Glu-186, and Glu-221) dramatically affected the activation constants as well as activity. A decrease of metal binding affinity was most significant in the presence of $Mg^{2+}$. When compared with the wild-type enzymes, the binding affinity of H220S and Nl85K for Mg^{2+} was decreased by 10-15-fold, while the affinity for $Mn^{2+}{\;}or{\;}Co^{2+}$ only decreased by 3-5-fold. All the mutations close to the M2 site changed their metal preference from $Mg^{2+}{\;}to{\;}Mn^{2+}{\;}or{\;}Co^{2+}$. These altered metal preferences may be caused by a relatively weak binding affinity of $Mg^{2+}$ to the enzyme. Thermal inactivation studies of mutants at the M2 site also support the importance of the M2 site geometry for metal specificity as well as the thermostability of the enzyme. Mutations of other important groups hardly affected the metal preference, although pronounced effects on the kinetic parameters were sometimes observed. This study proposes that the metal specificity of D-xylose isomerase can be altered by the perturbation of the M2 site geometry, and that the different metal preference of Group I and GroupII D-xylose isomerases may be caused by nonconserved amino acid residues around the M2 site.

• Hwankyungkyoyuk
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• v.13 no.2
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• pp.51-62
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• 2000

This study examined the current status of school environmental education (EE) in Germany, and attempted to propose strategies to develop school EE in Korea. The study intended to accomplish the following goals: First, this study attempted to examine the developmental process of school EE in Germany. Second, exemplary cases of site-based experiential education in Germany are selected and analysed to develop pedagogical strategies in school EE in Korea. The strategies for development proposed in this study can be summarized as follows: First, the focus of EE should go beyond that of "solving or curing"environmental problems and pollutions, and need to be re-directed to pursue an "education for sustainable development", a new paradigm for future EE. Second, EE should increasingly integrate outdoor site-based, experiential programs into the currently classroom-based and knowledge-driven forms of education, not only to maximize its educational effect but also and knowledge-driven forms of education, not only to maximize its educational effect but also to coordinate the instruction of EE in the context of the educational reform agenda, currently undergoing since the late 1990s, in Korea. Third, teaching-learning materials for EE should be variously developed, and programs should be encouraged to serve local needs and circumstances for effective classroom practices, and criteria for standardization and professionalization should be sought in developing these programs. Fourth, it is recommended that the Ministry of Environment secure funds to facilitate the local school authorities at the municipal and provincial levels to operate a mobile environmental support system, equivalent to the function of the "Lumbricus"in Germany. Fifth, an external support network should be established among the support agencies for EE. Especially, a professional agency or institute to academically support school EE and a special planning committee for enhancing EE need to be established for resource and personal development. Parents′voluntary participation should also be encouraged to establish a tripartite network of "school-community-government" to support and facilitate school EE.

• Korean Journal of Microbiology
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• v.28 no.1
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• pp.19-26
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• 1990

To examine the effects of sequence variations near the transcriptional start site on the rate of formation of the open complexes at bacteriophage $\lambda P_{R}$ promoter, two mutant promoters were created by site-specific mutagenesis using synthetic oligonucleotides. Mutant I coatains changes at positions -3 and -4 from TT to CC, thus having a 6-bp long G/C stretch between -10 region and transciptional start site (+1). Mutant II has changes at positions -5 and -6 from GG to AA, thereby having a 9-bp long A/T stretch between positions -11 and -3. Selective filter binding assays were performed to measure the rate of formation of the open complexes between the wild-type or two mutant $P_{R}$ promoters on 664 bp fragments and E. coli RNA polymerase at two temperatures. At 37.deg.C, the wild-type and two mutants showed similar rates for the formation of open complex. The second order rate constant $k_{a}$ and $\tau _{int}$, as determined from the .tau.-plot analysis, were $(6.0\pm0.4)\times10^{6}M^{-1}sec^{-1}$ and $11\pm5$sec, respectively. At 18.deg.C, however, the wild-type and two mutant promoters showed differences in the kinetic parameters. k for the wild-type promoter was (2.2$\pm$0.1)\times 10^{6}M^{-1}sec^{-1}$ and $\tau _{int}$ was 76$\pm$sec. Mutant I and II exhibited differences mainly in the rate of isomerization ($\tau_{int,I}=91\pm$10 sec, int,II=34$\pm$ sec), whereas the second order rate constant $k_{a}$ was similar to the wild type value. This result implies that at $18^{\circ}C$, the isomerization rate is determined by both protein conformational change and DNA melting, which are separable kinetically according to the 3-step mechanism of Roe et al.(1984,1985), and that the base changes affected mainly the rate of DNA melting as predicted.lting as predicted.

• Journal of architectural history
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• v.29 no.6
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• pp.101-112
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• 2020

This study focuses on the construction of Gyeongbokgung Palace in the second year of King Gojong's reign, which has been spotlighted for political and economic history. The author analyzed the contents of wood procurement with the Yeonggeon Diary, which records each day of construction site. The results are as follows: First, the 2nd year of King Gojong's reign, Yeonggeon of Gyeongbokgung Palace, was a new building that reflected the old system and 270 years of changed environment on the existing site. Despite the poor economic conditions, it began with years of effort and voluntary volunteer work and dedication. Second, the priority of timber transport was recruiting people in the whole process and the supply and demand of transportation tools. Carrying lumber from the mountains to the riverside and floating it at the right time were all a matter of manpower. Soldiers and carts were used to carry timber that arrived in Hangang River to the construction site. The cart was a consumable product, so it was necessary to continuously use the wood to make cart at the site. Third, fire and flood were the biggest obstacles to the Yeonggeon schedule of Gyeongbokgung Palace. Especially the fire was fatal. It was difficult to extinguish the fire in temporary structure, where was the storage for wood to construct. These disasters greatly affected the construction cost and construction period. Wood procurements of Gyeongbokgung Palace were based on public offerings. At the same time, recycled materials from other palace wood and nearby houses, nationwide buying of private mountain wood, the logging of royal tombs and some of the buildings of Gyeonghui Palace and Changgyeong Palace were relocated.

• Journal of the Korean Institute of Landscape Architecture
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• v.15 no.2
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• pp.79-90
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• 1987

This second consecutive research was connected to 7he previous first research with same title. The purpose of this research is to estimate the carrying capacity for the Seonjeong royal tomb and to propose its management planning. User's characteristics and relationship between user's density and vegetational environment were analized for the above objective. The result of this research shall be summarized as follows. 1. The site was damaged seriously by pupils and social groups'picnic activities concentrated in special periods of Friday and weekend during April and May. 2. Social-psychological carrying capacity estimation would be impossible due to lack of relationship between user's density and satisfaction. 3. Maximum user's density limits as a ecological carrying capacity was 1.4 persons per 100 square meters and modified optimum ecological carrying capacity was estimated as 1.0persons per 100 square meters. Maximum visitors as a optimum carrying capacity of the Seonjeong royal tomb area was estimated as 6,000 persons when supposing the proposed landuse planning. 4. To restore and preserve the tomb landscape as a traditional historic site, Seonjeong royal tomb shall be managed by three landuse areas ; protection and control area, natural picnic area and shaded picnic area. And the protection and control area include three sites ; natural reclamation site, natural preservation site and tomb landscape conservation site.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.3
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• pp.1-16
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• 2006

The purpose of this study is to develop design model of ecological park as stormwater storage facilities. The results are as follows : First, the design model of ecological park as stormwater storage facilities consider ecological and landscape characteristics such as high efficiency of land use, function as disaster prevention, ecological water purification, formation of habitat for flora and fauna. Second, this study demonstrates two types of plane structure and eight types of designed section. They can be combined and designed depending on conditions of each site. The facilities of stormwater storage conduct disaster prevention system and ecological park. Retention pond in stormwater storage facilities for ecological park also should be made for ecological restoration in the site. Third, the ecological park provide the basis for ecological network from in-site to out-site. Therefore its conservation and restoration plan consider the ecosystems of the site. Fourth, the most important factor for maintenance and management for retention pond is keeping water quality. Sustainable Structured wetland Biotop system is suggested for ecological water purification system in the retention pond which is one of the constructed wetland system using multi-celled aquatic plant and pond. This system can also provide habitat for animals and plants, water friendly park for men, and beautiful landscape.

• Journal of the Korean Institute of Rural Architecture
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• v.13 no.2
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• pp.79-86
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• 2011

The purpose of this study is to understand a architectural characteristics of local church in Virginia, U. S. This study focuses on not only analyzing the worship and service program inherent in the site planning of local church but also introducing worship service space and chancel elements of it in the village of garden area. We surveyed five protestant churches where are located in suburban and rural area outside of Midlothian city in the early August, 2010. I surveyed church building site and worship service space of churches focused on platform design, interviewed the historical background and program of churches with ministers, and corrected annual calender and newsletter. The results of this study are as follows. First, the characteristics of site plan have a comfortable parking lots and site of churchyard(cemetery) with playground that can take an activities out of chapel. The axis of church building follows to front street. Second, worship services keep two types of traditional and comtemporary worship in order to consider of both adult and youth members. The worship hall has a balance of bilateral symmetry. Third, the form of platform is built that is able to perform a music drama and movement of sermon without only one church, GraceLand Church that church building has over fifty years, and they stick to simple traditional type of Chancel that is established by pulpit, table(altar), baptistery(only baptist church), music instruments, and so on.

• The Journal of the Korea Contents Association
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• v.2 no.3
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• pp.59-69
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• 2002

This article purpose are on the variables of consumer's Doe sensitivity. Our result from sets of data indicate that the web site trust, the web site interactivity and the perceived risk have an effect on price search. Our result is as follows. First, the more trust the web site, the lower the price search. Second, the more interactivity of the web site, the lower the price search. Third, the greater the depth of information at the web site, the higher the price search. forth, the higher the perceived risk, the higher the price search. Fifth, the higher the knowledge of product, the higher the price search.

• Journal of Information Management
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• v.38 no.3
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• pp.59-80
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• 2007

In this study, we analyzed the web site navigation of law school libraries in terms of global, local, context, support navigation. The recommendations for good web site design were as follows. First, global navigation should provide the consistent navigation and be able to access to the important site and function. Second, quick links of local navigation need to provide the movement of scroll bar. The number of menu and type of link in context navigation should provide the least number. Finally, the site map and index should provide with qualified contents and minimal errors.

• Culinary science and hospitality research
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• v.6 no.1
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• pp.123-149
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• 2000

As a result of their web sites about 25 food services, it shows that only 20% of food services are conducting transactions online. As a whole food services in general have mastered the basics of setting up a web site, and it is revealed that some web sites with high average score are using flash s/w, which has a considerable interest in graphic. Family restaurant is the highest in average score and icecream is the lowest. The best individual site is Tonyromas site of Family restaurant sector, the second best site is TGI Friday's of the same Family restaurant sector, the third Pizzahut of pizza sector, and the fourth Lotteria site of Fast food sector. It is suggest that this preliminary study could be advanced by extending the sample size and a program of more extensive statistical analysis by devising. Also it is shows that it is possible for B2B transaction and B2C transaction to be conducted more actively It is suggested that Pizza(60%) and Icecream(40%) of food products which are small in size and easy to be ordered and delivered can be feasible and successful in transactions online. In conclusion, it is very important to keep the contents of web sites up-to-date and attractive to customers, and to establish several ways which can enable customers to interact with food services to induce a dialogue with customers, and it is necessary to introduce new technologies for specific differences of their own sites.