• Journal of Soil and Groundwater Environment
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• v.10 no.3
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• pp.9-15
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• 2005

Soil aquifer treatment is a water reuse technology that secondary or tertiary treated wastewater is infiltrated into the aquifer in which physical and biochemical reactions occur. Major consideration in SAT is the removal and transport of DOC and nitrogen species. In this study, reaction mechanism in SAT was examined considering nitrification, denitrification and organic oxidation. In addition, SAT modeling system was developed as the reaction mechanism was applied to groundwater flow and transport model. In verification of the reaction module by 1-dimensional unsaturated soil column test, the experimental data of all of the species, ammonium, nitrate, DOC and DO, were well matched with the simulation results. In sensitivity analysis, ammonium partition coefficient, dissolved oxygen inhibition constant and biomass decay rate affect ammonium, DOC and DO concentration of effluent, respectively.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.4
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• pp.55-65
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• 2003

Pilot study was conducted to examine the effects of ponded-water depth and reclaimed wastewater irrigation on paddy rice culture. For the ponded-water depth effect, three treatments of shallow, traditional, and deep water depths were applied, and each treatment was triplicated. The irrigation water for the treatment pots was an effluent from constructed wetland system for sewage treatment, while the control pot was irrigated with tap water kept traditional ponded-water depth. Irrigation water quantity varied with ponded-water depth as expected and drainage water quantity also varied similarly, which implies that shallow irrigation might save irrigation water and also reduce environmental impacts on downstream water quality. Rice growth and production were not significantly affected by ponded-water depth within the experimental condition, instead there was an indication of increased production in shallow and deep ponded-water depths compared to the traditional practice. Raising drainage outlet to the adequate height in paddy dike might be beneficial to save water resources within the paddy field. There was no adverse effect observed in reclaimed wastewater irrigation on the rice production, and mean yield was even greater than the control pots with tap water irrigation although statistically not significant. Water-saving irrigation by shallow ponded-water depth, raising the outlet height in diked rice paddy fields, minimizing forced surface drainage by well-planned irrigation, and reclaimed wastewater irrigation are suggested to save water and protect water quality. However, deviation from traditional farming practices might affect rice growth in long term, and therefore, further investigations are recommended before full scale application.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.4
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• pp.1208-1222
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• 2014

Due to the low utilization and scarcity of frequency spectrum in current spectrum allocation methodology, cognitive radio networks (CRNs) have been proposed as a promising method to solve the problem, of which spectrum sensing is an important technology to utilize the precious spectrum resources. In order to protect the primary user from being interfered, most of the related works focus only on the restriction of the missed detection probability, which may causes over-protection of the primary user. Thus the interference probability is defined and the interference-aware sensing model is introduced in this paper. The interference-aware sensing model takes the spatial conditions into consideration, and can further improve the network performance with good spectrum reuse opportunity. Meanwhile, as so many fading factors affect the spectrum channel, errors are inevitably exist in the reporting channel in cooperative sensing, which is improper to be ignored. Motivated by the above, in this paper, we study the throughput tradeoff for interference-aware cognitive radio networks over imperfect reporting channel. For the cooperative spectrum sensing, the K-out-of-N fusion rule is used. By jointly optimizing the sensing time and the parameter K value, the maximum throughput can be achieved. Theoretical analysis is given to prove the feasibility of the optimization and computer simulations also shows that the maximum throughput can be achieved when the sensing time and the parameter of K value are both optimized.

• Journal of the Korea Society of Computer and Information
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• v.10 no.1 s.33
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• pp.73-84
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• 2005

An increasing in quantity of multimedia data brought a new problem that expected data should be retrieved fast and exactly. The adequate representation is a key element for the efficient retrieval For this reason, the MPEG-7 standard was established for description of multimedia contents in 2001. Recently, the new metadata were developed to represent characteristics of movie information resources by Korea Federation of Film Archives. In this paper. we designed and implemented a movie information retrieval system. This system used XML schema to accept movie information metada. This system offers a keyword retrieval using high-level metadata based on movie information and similarity retrieval using low-level metadata based on MPEG-7. As a result, that ill be Possible more efficient movie information interchange . movie information metadata reuse and fast retrieve.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.4
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• pp.55-66
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• 2017

Korean small and medium sized software companies have tried to export their solutions or services to overseas markets. In 2016, exports of the software industry increased by 6.0% from the previous year, and the value added of the industry was 2.2 times higher than that of the manufacturing industry. From a long-term perspective, it is important to secure a global competitive advantage in order to sustain the export high value-added of the software industry. The obstacles to entry into the overseas market of small to medium enterprises are as follows: first, difficulty in product development and localization of marketing; second, lack of investment for overseas expansion; and finally, competitiveness of software technology. In particular, To overcome such obstacles, Korean small and medium sized software companies should increase the technical perfection and secure software export competitiveness. The paper presents a payment settlement framework enabling adaptive reuse and semiautomatic development of global payment settlement services. The quantitative and qualitative evaluation results are presented with domestic and overseas case studies as follows: Firstly, semi-automatic development is realized successfully by applying the framework. Secondly, it is possible to maintain consistent quality of software and to deliver maintenance services without relying on the internal human resources. Thirdly, it is possible to reduce the project duration of the same development cope to less than 50% by applying the framework. Finally, because it is based on BPMN 2.0, which is a high level design diagram, it is expected that it will be easy to implement through components connection and reduce difficulties in technology transfer and localization. Also, at the time of runtime operation, it will be effective to understand the design idea easily and to carry out additional developments without human resource who participated in the initial project.

• The KIPS Transactions:PartD
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• v.11D no.3
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• pp.683-690
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• 2004

MND(Ministry of National Defense) has developed .nm AF(Ministry of National Defense Architecture Framework) to guarantee interoperability among defense information systems. Users can easily and consistently develop architecture products through MND AF. There is necessity for development if CADM(Core Architecture Data Model), which facilitate exchange, integration, and comparison for architecture data, to store architecture data from architecture products and reuse them. We developed CADM from defining entities and relationships that satisfy data requirement of each architecture product from MND AF. After we developed architecture products about MIMS(Military Intelligence Management System), and inserted these architecture data to CADM repository. we verified CADM entities and relationships through query. Through CABM which provides common data model for the whole my architectures, interoperability and integration among defense information systems ran be improved, and integrated defense information resources efficiently can be managed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.10
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• pp.1986-1993
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• 2015

We investigate the optimal resource and power allocation for device-to-device (D2D) communications in a multicell environment. When D2D links reuse the cellular radio resources, each D2D user will interfere with a cellular link and other D2D links, in its own cell as well as in adjacent cells. Under such situation, we propose a coordinated resource allocation scheme that can handle the intercell interferences as well as the intracell interference. For a given resource allocation, we also formulate a power optimization problem and present an algorithm for finding the optimal solution. The resource and power allocation algorithms are designed to maximize the achievable rate of the D2D link, while limiting the generated interference to the cellular link. The performance of the proposed algorithms is evaluated through simulations in a multicell environment. Numerical results are presented to verify the coordination gain in the resource and power allocation.

• Journal of Korea Port Economic Association
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• v.25 no.4
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• pp.251-280
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• 2009

The value of Environment is so high and important that no one can estimate it correctly. In the area of Logistics, Environment protection is very important and keen subject for the present and for the future of this country and people. Environmental logistics, similarly used as Green logistics, means the protection of Nature and Environment and reduces all kinds of factors and behaviors that may destroy and deteriorate current Environment. It also include the preservation of Nature and sustainable development. Environmental logistics aims to save natural resources and to promote reuse of all kinds of materials and to increase the utilization of Environment friendly substitute goods. In this paper the concept and characteristics of Environmental logistics were summarized and described. Also the main previous studies were surveyed. Some of important cases and experiences which were introduced and applied in major countries such as Japan, Hongkong, USA and the case of PHILIPS were summarized and analyzed. With these cases and analysis, this paper suggested some alternatives and countermeasures for the improvement of Environmental logistics in terms of 3 dimensions such as Country, Company and Individual level. And a strategy model for enhancement of the Environmental logistics was suggested and limitations of this paper and future research directions were described.

• Journal of the Korean Society for Library and Information Science
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• v.40 no.4
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• pp.267-286
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• 2006

Tools are needed to have access to more effective information and to select it in the environment of digital information where information pours in. and some of the advanced techniques to make up these tools are metadata and annotation. Annotation additionally records the marks for the supplementary explanation of and emphasis on a specific part of the original text and kas more various merits than metadata in terms of the search and use of digital resources. This research aims at suggesting methods that annotation. which has a range of functions including access to information. its reuse and sharing in the digital surroundings of late, can be applied to digital contents such as web services, digital libraries and electronic books. As to the research method, the case studies of annotation systems applied to web services and digital libraries have been carried out, and the metadata formation of the systems has been analyzed.

• Journal of Satellite, Information and Communications
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• v.6 no.2
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• pp.26-34
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• 2011

In Femtocell that provides high quality of indoor communications with low transmitted power, there are two typical Access modes; Closed Access mode and Open Access mode. In this paper, we propose resource allocation scheme, which mitigates difference of performance between Access modes and improves overall cell performance, according to Access mode. We give more wireless resources to Open Access mode Femtocell, which improves performance of other users, than Closed Access mode Femtocell. If Open Access mode Femtocell uses more resource, there is trade-off between improvement of user using Open Access mode Femtocell and increase of interference that other users receive. So, we solve the optimal value for resource allocation and analyze performance of conventional scheme and proposed scheme applying the optimal value. Eventually, proposed scheme can improve overall cell performance relative to conventional scheme.