• Journal of Intelligence and Information Systems
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• v.20 no.1
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• pp.195-211
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• 2014

Cloud computing services provide IT resources as services on demand. This is considered a key concept, which will lead a shift from an ownership-based paradigm to a new pay-for-use paradigm, which can reduce the fixed cost for IT resources, and improve flexibility and scalability. As IT services, cloud services have evolved from early similar computing concepts such as network computing, utility computing, server-based computing, and grid computing. So research into cloud computing is highly related to and combined with various relevant computing research areas. To seek promising research issues and topics in cloud computing, it is necessary to understand the research trends in cloud computing more comprehensively. In this study, we collect bibliographic information and citation information for cloud computing related research papers published in major international journals from 1994 to 2012, and analyzes macroscopic trends and network changes to citation relationships among papers and the co-occurrence relationships of key words by utilizing social network analysis measures. Through the analysis, we can identify the relationships and connections among research topics in cloud computing related areas, and highlight new potential research topics. In addition, we visualize dynamic changes of research topics relating to cloud computing using a proposed cloud computing "research trend map." A research trend map visualizes positions of research topics in two-dimensional space. Frequencies of key words (X-axis) and the rates of increase in the degree centrality of key words (Y-axis) are used as the two dimensions of the research trend map. Based on the values of the two dimensions, the two dimensional space of a research map is divided into four areas: maturation, growth, promising, and decline. An area with high keyword frequency, but low rates of increase of degree centrality is defined as a mature technology area; the area where both keyword frequency and the increase rate of degree centrality are high is defined as a growth technology area; the area where the keyword frequency is low, but the rate of increase in the degree centrality is high is defined as a promising technology area; and the area where both keyword frequency and the rate of degree centrality are low is defined as a declining technology area. Based on this method, cloud computing research trend maps make it possible to easily grasp the main research trends in cloud computing, and to explain the evolution of research topics. According to the results of an analysis of citation relationships, research papers on security, distributed processing, and optical networking for cloud computing are on the top based on the page-rank measure. From the analysis of key words in research papers, cloud computing and grid computing showed high centrality in 2009, and key words dealing with main elemental technologies such as data outsourcing, error detection methods, and infrastructure construction showed high centrality in 2010~2011. In 2012, security, virtualization, and resource management showed high centrality. Moreover, it was found that the interest in the technical issues of cloud computing increases gradually. From annual cloud computing research trend maps, it was verified that security is located in the promising area, virtualization has moved from the promising area to the growth area, and grid computing and distributed system has moved to the declining area. The study results indicate that distributed systems and grid computing received a lot of attention as similar computing paradigms in the early stage of cloud computing research. The early stage of cloud computing was a period focused on understanding and investigating cloud computing as an emergent technology, linking to relevant established computing concepts. After the early stage, security and virtualization technologies became main issues in cloud computing, which is reflected in the movement of security and virtualization technologies from the promising area to the growth area in the cloud computing research trend maps. Moreover, this study revealed that current research in cloud computing has rapidly transferred from a focus on technical issues to for a focus on application issues, such as SLAs (Service Level Agreements).

• Journal of Korean Society of Environmental Engineers
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• v.34 no.4
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• pp.223-231
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• 2012

The purpose of this study is to investigate basically the mechanism of heat transfer by the resolution of complex fluid flow inside a sophisticated designed screw dryer for the treatment of sewage sludge by using numerical analysis and experimental study. By doing this, the result was quite helpful to obtain the design criteria for enhancing drying efficiency, thereby achieving the optimal design of a multiple screw type dryer for treating inorganic and organic sludge wastes. One notable design feature of the dryer was to bypass a certain of fraction of the hot combustion gases into the bottom of the screw cylinder, by the fluid flow induction, across the delicately designed holes on the screw surface to agitate internally the sticky sludges. This offers many benefits not only in the enhancement of thermal efficiency even for the high viscosity material but also greater flexibility in the application of system design and operation. However, one careful precaution was made in operation in that when distributing the hot flue gas over the lump of sludge for internal agitation not to make any pore blocking and to avoid too much pressure drop caused by inertial resistance across the lump of sludge. The optimal retention time for rotating the screw at 1 rpm in order to treat 200 kg/hr of sewage sludge was determined empirically about 100 minutes. The corresponding optimal heat source was found to be 150,000 kcal/hr. A series of numerical calculation is performed to resolve flow characteristics in order to assist in the system design as function of important system and operational variables. The numerical calculation is successfully evaluated against experimental temperature profile and flow field characteristics. In general, the calculation results are physically reasonable and consistent in parametric study. In further studies, more quantitative data analyses such as pressure drop across the type and loading of drying sludge will be made for the system evaluation in experiment and calculation.

• Economic and Environmental Geology
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• v.38 no.5 s.174
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• pp.571-577
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• 2005

Permeable reactive barrier using iron oxide coated sand is one of effective technologies for As(V) contaminated groundwater. However, this method is restricted to As(III), because As(III) species tends to be more weakly bound to adsorbent. In order to overcome the limitation of iron oxide coated sand application to As(III) contaminated groundwater, manganese oxide materials as promoter of As(III) removal were combined to the conventional technology in this study. For combined use of iron oxide coated sand and manganese oxide coated sand, two kinds of removal methods, sequential removal method and simultaneous removal method, were introduced. Both methods showed similar removal efficiency over $85\%$ for 6 hrs. However, the sequential method converted the As contaminated water to acid state (pH 4.5), on the contrary, the simultaneous method maintained neutral state (pH 6.0). Therefore, simultaneous As removal method was ascertained as a suitable treatment technology of As contaminated water. Moreover, for more effective As(III) remediation technique, polypropylene textile which has the characteristics of high surface area, low specific gravity and flexibility was applied as alternative material of sand. The combined use of coated polypropylenes by simultaneous method showed much more prominent and rapid remediation efficiency over $99\%$ after 6 hrs; besides, it has practical advantages in replacement or disposal of adsorbent for simple conventional removal device.

• Korean Journal of Health Education and Promotion
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• v.6 no.2
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• pp.23-39
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• 1989

There have been a lot of considerable. discussion and debate surrounding the management model in the health insurance management system and opinions regarding the management operating cost. It is a well known fact that there have always been dissenting opinions and debates surrounding the issue. The management operating cost varies according to the scale of the management organization and component members characteristics of the insurance carrier. Therefore, it is necessary to examine and compare the management operating cost to the simulated management models developed to cover those eligible for the health insurance scheme in this country. Since the management operating cost can vary according to the different models of management, four alternative management models have been established based on the critical evaluation of existing theories concerned, as well as on the basis of the survey results and simulation attempts. The first alternative model is the Unique Insurance Carrier Model(Ⅰ) ; desigened to cover all of the people with no classification of insurance qualifications and finances from the source of contribution of the insured, nationwide. The second is the Management Model of Large-scale District Insurance Carrier(Ⅱ) ; this means the Korean society would be divided into 21 large districts; each having its own insurance carrier that would cover the people in that particular district with no classification of insurance qualifications arid finances as in Model I. The third is the Management Model of Insurance Carrier Divided by Area and Classified with Occupation if Largescale (Ⅲ) ; to serve the self-employed in the 21 districts divided as in Model Ⅱ. It would serve the employees and their dependents by separate insurance carriers in large-scale similar to the area of the district-scale for the self-employed, so that the insurance qualifications and finances would be classified with each of the insurance carriers: The last is the Management Model of the Multi - insurance Carrier (Ⅳ) based on the Si. Gun. Gu area which will cover their own self- employed people in the area with more than 150 additional insurance carriers covering the employees and their dependents. The manpower necessary to provide services to all of the people according to the four models is calculated through simulation trials. It indicates that the Management Model of Large-scale District Insurance Carrier requires the most manpower among the four alternative models. The unit management operating costs per the insured individuals and covered persons are leveled with several intervals based on the insurance recipients. in their characteristics. The interval levels derived from the regression analysis reveal that the larger the scale of the insurance carriers is in the number of those insured and covered. the more the unit management operating cost decreases. significantly. Moreover. the result of the quadratic functional formula also shows the U-shape significantly. The management operating costs derived from the simulated calculation. on the basis of the average salary and related cost per staff- member of the Health Insurance Societies for Occupational Labours and Korean Medical Insurance Corporation for the Official Servants and Private School Teachers in 1987 fiscal year. show that the Model of Multi-insurance Carrier warrants the highest management operating cost. Meanwhile the least expensive management operating cost is the Management Model of Unique Insurance Carrier. Insurance Carrier Divided by Area and Classified with Occupation in Large-scale. and Large-scale District Insurance Carrier. in order. Therefore. it is feasible to select the Unique Insurance Carrier Model among the four alternatives from the viewpoint of the management operating cost and in the sense of the flexibility in promoting the productivity of manpower in the human services field. However. the choice of the management model for health insurance systems and its application should be examined further utilizing the operation research analysis for such areas as the administrative efficiency and factors related to computer cost etc.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.4
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• pp.64-74
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• 2010

The study is based on an urban park design that is designed in consideration of the characteristics of Uijeongbu City, applied with adequate functions for the environment and showcasing the unique scenery in relation to the relocation of the US Air Force Camp Falling Water. The bases of the design are: the reasonable convergence of the square and park in consideration of the site characteristics; the application of an urban context as the park is located near a station; and the realization of an eco-friendly space. This study is based on foundation research regarding a review of urban square patterns, particular items in planning in relation to modern urban parks and the adaptability of the park in the future. Regarding space usage, the design is applied with notable ideas that allow the space to make its own characteristics through voluntary user activity in conjunction with the environment that will allow the park to cope with changes in the future, as opposed to a space that users experience through pre-determined programs. Below are the focal points of the design. First, the park is designed as an empty space which may accommodate the urban structural context of and usage patterns for being a field of the city ecology that changes and develops, beyond a passively-created square pattern. Such open spaces have a continuity which allows it to adapt to the development of the city. In addition, the design facilitates spontaneous processes through changes in usage pattern and time. Second, the design includes the message that the park and the city, natural things and artificial things, must communicate and network with each other. Hence the park shall not be an isolated green island within the city, but is an open space accommodating the demands for open area from nearby commercial, public and residential facilities; the park shall include a field that can accommodate a variety of programs. Third, the park is designed to encourage the effect of direct and indirect practical education by reflecting a physical plan as well as interesting experience design methods to lower carbon emissions and to create and maintain an eco-friendly space, the basis of a zero-emissions city.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.12C
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• pp.1288-1298
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• 2002

To implement elliptic curve cryptosystem in GF(2$\^$m/) at high speed, a fast divider is required. Although bit-parallel architecture is well suited for high speed division operations, elliptic curve cryptosystem requires large m(at least 163) to support a sufficient security. In other words, since the bit-parallel architecture has an area complexity of 0(m$\^$m/), it is not suited for this application. In this paper, we propose a new serial-in serial-out systolic array for computing division operations in GF(2$\^$m/) using the standard basis representation. Based on a modified version of tile binary extended greatest common divisor algorithm, we obtain a new data dependence graph and design an efficient bit-serial systolic divider. The proposed divider has 0(m) time complexity and 0(m) area complexity. If input data come in continuously, the proposed divider can produce division results at a rate of one per m clock cycles, after an initial delay of 5m-2 cycles. Analysis shows that the proposed divider provides a significant reduction in both chip area and computational delay time compared to previously proposed systolic dividers with the same I/O format. Since the proposed divider can perform division operations at high speed with the reduced chip area, it is well suited for division circuit of elliptic curve cryptosystem. Furthermore, since the proposed architecture does not restrict the choice of irreducible polynomial, and has a unidirectional data flow and regularity, it provides a high flexibility and scalability with respect to the field size m.

• Journal of the Korean Geographical Society
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• v.28 no.2
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• pp.148-162
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• 1993

There is much speculation that modern capi-talist society is undergoing fundamental and qualitative chnge towards flexible specialization. The purpose of this study is to examine this hypothesis. This paper focusses on: the idea of flexible specialization; the significance of this transition; industrial district; and the implicati-ons of this new production system for Korean industrial space. Main arguments of this study are as follows: First, as all different groups of researchers apply the idea of flexible specialization according to their own specifications, the current debate on this topic is not much fruitful. Not surpri-singly, the concept of flexible specialization has overlapped with subocontracting. This intergration of subcontracting into flexible specialization systems, however, is inappropriate because the two concepts have different historical contexts. The other cause of this controversy is its inherent weekness, conceptual ambiguity. Thus, today's flexibility becomes tomorrow's rigidity. Secondly, transition towards flexible speciali-zation has only been partially achieved even in advanced capitalist countries. The application of dualistic explanatory framework, such as rigidity versus flexibiity, mass production versus small-lot multi-product production, and de-skilling versus re-skilling, has resulted in great exaggeration of the transformation, from Fordism to post-Fordism. There is no intermediary part between two places. Considering that the workers allocated to the Fordist mass production assembly line are not as large as one might imagine, the shift from mass to flexible production has only limited implications for the transformation of capitalist economy. Thirdly, 'industrial district' contorversy has contributed to highlighting the importance of small firms and areas as production space. The agglomeration of small firms in specific areas is common in Korea, but it is quite different from the industrial district based on flexible specialization. The Korean phenomenon stems from close interactions with its major parent firm rather than interactions between flexible, specialized, autonomous and technology-intensive smll firms. Most Korean subcontractors are still low-skilled, labour-intensive, and heavily dependent on their mojor parent firms. Thus, the assertion that the Seoul Metropolitan Area adopts flexible specialization has no base. Fourthly, the main concern of flexible speciali zation is small firms. However, the corporate organization that needs product diversification and technological specialization is oligopolistic large corporations typified by multinational corporations. It is because of this that most of these organizations are adoptiong Fordist mass production methods. The problem of product diversification will be resolved naturally if economic internationalization progresses further. What is more important for business success is the quality and price competitiveness of firms rather than product diversification. Lastly, in order to dispel further misunderst-anding on this issue, it is imparative that the conceptual ambiguity is resolved most urgently. This study recommends adoption of more speci-fied and direct terminology (such as, factory automation, computer design, out-sourcing, the exploitation of part-time labor, job redesign) rather than that of ideological ones (such as, Taylorism, Fordism, neo-Taylorism, neo-Fordism, post-fordism, flexible specialization, peripheral post-Fordism). As the debates on this topic just started, we still have long way to go until consensus is reached.

• Journal of Legislation Research
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• no.53
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• pp.177-211
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• 2017

In the course of the emergence and development of new ICT technologies and services such as Big Data, Internet of Things and Artificial Intelligence, the future will change by these new innovations in the Fourth Industrial Revolution. The future of this fourth industrial revolution will change and our future will be data-based society or economy. Since there is personal information at the center of it, the development of the economy through the utilization of personal information will depend on how to make the personal information protection laws. In Korea, which is trying to lead the 4th industrial revolution, it is a legal interest that can not give up the use of personal information, and also it is an important legal benefit that can not give up the personal interests of individuals who want to protect from personal information. Therefore, it is necessary to change the law on personal information protection in a rational way to harmonize the two. In this regard, this article discusses the problems of duplication and incompatibility of the personal information protection law, the scope of application of the personal information protection law and the uncertainty of the judgment standard, the lack of flexibility responding to the demand for the use of reasonable personal information, And there is a problem of reverse discrimination against domestic area compared to the regulated blind spot in foreign countries. In order to solve these problems and to improve the legislation of personal information protection in the era of the fourth industrial revolution, we proposed to consider both personal information protection and safe use by improving the purpose and regulation direction of the personal information protection law. The balance and harmony between the systematical maintenance of the personal information protection legislation and laws and regulations were also set as important directions. It is pointed out that the establishment of rational judgment criteria and the legislative review to clarify it are necessary for the constantly controversial personal information definition regulation and the method of allowing anonymization information as the intermediate domain. In addition to the legislative review for the legitimate and non-invasive use of personal information, there is a need to improve the collective consent system for collecting personal information to differentiate the subject and to improve the legislation to ensure the effectiveness of the regulation on the movement of personal information between countries. In addition to the issues discussed in this article, there may be a number of challenges, but overall, the protection and use of personal information should be harmonized while maintaining the direction indicated above.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.5
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• pp.112-124
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• 2021

This study was conducted to examine and analyze local governments, park status, project characteristics, and the implementation in detail for private park special projects across the country as a means of responding to the sunsetting of urban parks. As a result of the analysis, first, the private park special project, was found to be mainly implemented in cities with a population of more than 100,000, so there was a limit to the application on military installations or in local small cities. Therefore, rather than applying the special system collectively, it was judged that institutional flexibility, considering the characteristics and size of local government, was needed. Second, the current special projects by the park creation donation collection method shows monotonous development centered on apartment houses, so it is necessary to diversify the development by introducing a park preservation method that purchases and donates park sites. Third, it was found that the area standard needs to be eased to less than 50,000m² to include parks with high utilization and good accessibility in urban areas of large cities, as the type and area of parks are limited. Fourth, most special projects are mountain parks, which are feared to damage the natural terrain and skyline, so separate ordinances should be established and applied, and development approaches should be made to allow nature and parks to coexist with the setting of detailed building guidelines for each type of facility. The guidelines should include, first, after the nationwide private park special projects are completed, standards for appropriate returns for similar projects should be established, institutional standards such as the recovery of excess profits should be established, and environmental reviews should be conducted. Second, it was found that local governments should institutionalize the composition of private consultations to promote the efficient management of projects through a cooperative system, and third, a roadmap for maintenance after the donation of special parks should be established.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.3
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• pp.11-28
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• 2021

Due to its size and complex characteristics, it is not often to newly create a large park within an existing urban area. Also, there has been a lack of research on the planting design methodologies for a large park. This study aims to elucidate how ecological ideas can be applied to planting practice from a designer's perspective, and eventually suggest a planting design framework in the actual case, the Central Park in the City of Gwangju. This framework consists of spatial structure of planting area in order to connect and unite the separated green patches, to adapt to the changes of existing vegetation patterns, to maintain the visual continuity of landscape, and to organize the whole open space system. The framework can be provided for the spatial planning and planting design phase in which the landscape designer flexibly uses it with the design intentions as well as with an understanding of the physical, social, and aesthetic characteristics of the site. The significance of this approach is, first that it can maintain ecological and visual consistency of the both existing and introduced landscapes as a whole in spite of its intrinsic complexity and largeness, and second that it can help efficiently respond to the unexpected changes in the landscape. In the case study, comprehensive site analysis is conducted before developing the framework. In particular, wetlands and grasslands have been identified as potential wildlife habitat which critically determines the vegetation patterns of the green area. Accordingly, the lists of plant communities are presented along with the planting scheme for their shape, layout, and relations. The model of the plant community is developed responding to the structure of surrounding natural landscape. However, it is not designed to evolve to a specific plant community, but is rather a conceptual model of ecological potentials. Therefore, the application of the model has great flexibility by using other plant communities as an alternative as long as the characteristics of the communities are appropriate to the physical conditions. Even though this research provides valuable implications for landscape planning and design in the similar circumstances, there are several limitations to be overcome in the further research. First, there needs to be more sufficient field surveys on the wildlife habitats, which would help generate a more concrete planting model. Second, a landscape management plan should be included considering the condition of existing forest, in particular the afforested landscapes. Last, there is a lack of quantitative data for the models of some plant communities.