• Journal of Communications and Networks
• /
• v.13 no.6
• /
• pp.664-677
• /
• 2011

In order to control interference and improve spectrum efficiency in the femtocell and macrocell overlaid system (FMOS), we propose a joint frequency bandwidth dynamic division, clustering and power control algorithm (JFCPA) for orthogonal-frequency-division-multiple access-based downlink FMOS. The overall system bandwidth is divided into three bands, and the macro-cellular coverage is divided into two areas according to the intensity of the interference from the macro base station to the femtocells, which are dynamically determined by using the JFCPA. A cluster is taken as the unit for frequency reuse among femtocells. We map the problem of clustering to the MAX k-CUT problem with the aim of eliminating the inter-femtocell collision interference, which is solved by a graph-based heuristic algorithm. Frequency bandwidth sharing or splitting between the femtocell tier and the macrocell tier is determined by a step-migration-algorithm-based power control. Simulations conducted to demonstrate the effectiveness of our proposed algorithm showed the frequency-reuse probability of the FMOS reuse band above 97.6% and at least 70% of the frequency bandwidth available for the macrocell tier, which means that the co-tier and the cross-tier interference were effectively controlled. Thus, high spectrum efficiency was achieved. The simulation results also clarified that the planning of frequency resource allocation in FMOS should take into account both the spatial density of femtocells and the interference suffered by them. Statistical results from our simulations also provide guidelines for actual FMOS planning.

• Journal of Digital Contents Society
• /
• v.11 no.1
• /
• pp.25-38
• /
• 2010

There is no guideline or standard for the specification of the open-source-framework-based Spring AOP, and it causes confusion in development and maintenance. Moreover, the inconsistency between the existing MVC model, the AOP model that is used for Struts framework and the UML diagram makes the aspect reuse more difficult. In this study, a widened existing method was proposed so that Aspect, Pointcut and Advice could be expressed by either UML or XML to ensure that the Spring AOP can accept the combined use of the existing MVC model and the AOP model, which is used for Struts framework. Relationship was defined so that the mutual conversion could be possible with the proposed expression method, and the realization of simple development and maintenance was verified via the examples of mutual conversion. In addition, a packaging method to efficiently reuse aspect was proposed, and the possibility of reuse was verified.

• Journal of Korean Society on Water Environment
• /
• v.24 no.1
• /
• pp.86-90
• /
• 2008

Water reuse of effluent is limited, due to bacteria and chromaticity or turbidity which may result in low perception of water quality. Consequently, this study showed a method in the reuse of treated wastewater by a diversified treatment method, with separation of centralized reformation of aeration tank into pre-treatment with minimum installation of facilities, and post-treatment, applying advanced oxidation treatment. A pilot plant experiment was performed using Sym-Bio process adopting an NADH Sensor without modification of the exiting aeration tank. The Dissolved Ozone Flotation process, which is an advanced oxidation process, to treat the remaining organics, nutrients, chromaticity, turbidity and bacteria. As a result in the Sym-Bio process, the biological treatment, even on the condition of single stage reaction tank, the treatment efficiencies of BOD, $COD_{Mn}$, $COD_{Cr}$, SS and T-N were 96.6%, 84.6%, 88.25%, 95.1% and 71.0%, respectively, while that for T-P was 25.0%, which required further treatment. In the Dissolved Ozone Flotation process, the advanced oxidation treatment, the treatment efficiencies of BOD, $COD_{Mn}$, $COD_{Cr}$, SS, T-N, T-P, chromaticity, turbidity, bacteria, coliforms were 78.9%, 34.6%, 28.7%, 48.0%, 70.4%, 82.4%, 84.0%, 74.5%, 99.8% and 99.4%, respectively.

• The Journal of the Korea Contents Association
• /
• v.6 no.11
• /
• pp.235-242
• /
• 2006

Many researches have achieved to reuse existent experience at each step of software life cycle. It is achieved various study about Design Pattern serving that abstract level solves design problem at high level. But, design step is not supplying design information that is abstracted so that new designers may reuse standardizing defined good design information. Therefore, in this paper, to do so that can reuse existent design information because composes Design Pattern can solve problem at design step, and extend design information that also is standardized XMI to base meta model of Design Pattern. And I did so that can compose Design Pattern utilizing MetaModel of Design Pattern standardized by XMI. Therefore, software designer can reuse composing existent design information that is could standardize problem at design because uses MetaData of standardized Design Pattern, and designs by Design Pattern base.

• Korea Journal of Hospital Management
• /
• v.22 no.3
• /
• pp.18-30
• /
• 2017

This study was performed to analyze systematically and validate empirically the influence of korean medicine service quality on satisfaction factors and revisiting intention. The candidates were patients visiting the one korean medicine hospital in Gyeongnam. We took a direct survey collected during 15 days May 1 to 15, 2016. For the survey I distributed a total of 250 questionnaire and used the final 230 of them in verifying this research model except unreliable data. The collected data were used statistics program SPSS WIN 22.0 and the research model were examined by AMOS 18.0. The main research results are follows. First, the most influencing factors on consumer satisfaction were public image factors and then human factors. and then effectiveness factors. Second, the most influencing factors on reuse intention were public image factors and then physical factors. Third, human and effectiveness factors of service quality factors in korean medicine hospital did not effect on revisiting intention directly but, effected on revisiting intention through mediation role of the customer satisfaction. Forth, satisfaction on the significant effect on reuse intention. so satisfaction has proved to be a important factor for reuse intention. The results of this study are expected to contribute to management efficiency and developmental improvement on korean medicine hospital policy and management efficiency and be used as a basis for leading to national health promotion through the development of korean medicine service.

• Korean Institute of Interior Design Journal
• /
• v.23 no.1
• /
• pp.69-77
• /
• 2014

This study aims to find the optimum method to reuse as townscape resource and to preserve the architectural heritage. And, it wants to contribute the policy of the architectural heritage and townscape. This research is targeted at an old office building of Leaf tobacco Producer' cooperation, designated as a cultural assets in Jecheon. It investigated the design characteristics of an old office building of Leaf tobacco Producer' cooperation and the streetscape of Uibyeong-daero 12-gil. It was conducted using the research methods of the field survey, and it was to analyze and to compare the various existing data and a current status. The result are as followings. Firstly, we should be consider the policy of architectural heritage that a sense of place can be preserved. Secondly, we should be consider the linear method of the conservation and reuse in urban street that the architectural heritage is located at least. Thirdly, if it will be to maintain the facade of the building adjacent to the street using the design characteristics of an old office building of Leaf tobacco Producer' cooperation, Uibyeong-daero 12-gil will be made a unique street that will be represented the history of leaf tobacco produce. Lastly, it has been analyzed that the design characteristics of an old office building of Leaf tobacco Producer' cooperation are the arch of entrance, the arched window, the rectangular window, the entabature, the horizontal joint, the finish of cement mortar, a pitched roof, etc. And, the design guideline and the maintenance plan of Uibyeong-daero 12-gil have made.

• The KIPS Transactions:PartD
• /
• v.11D no.3
• /
• pp.605-616
• /
• 2004

The purpose of CBSD(Component Based Software Development) if to develop software using a reuse component and components assembly. The reused components have to be adapter for satisfaction of requirement specification. This paper represents a component adaption method which reuse previously developed component or legacy system, using an adaptation component called by TA(Transaction Adaptor). The adaptation using TA transmits XML data that is translated into stream type, from a client to on host system. And we introduce RS(Rule Server) which gets some Information from XML data for application program development. Through the Interaction of TA and RS, we can improve effectiveness of component development and maintenance and we can reuse legacy system.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37 no.8B
• /
• pp.687-694
• /
• 2012

In OFDMA-based cellular system, inter-cell interference (ICI) reduces system capacity by aggravating receiving performance of the users located in edge of the cell. Therefore, to mitigate ICI is very important issue in cellular system. To deal with ICI problem, fractional frequency reuse (FFR) is introduced. FFR is an interference management technique. It separates each cell into inner cell and outer cell. Then, it allocates whole system bandwidth to inner cell and different frequency partition to each sector of outer cell. By doing this, outer cell users can ignore interferences from adjacent cells. So, the receiving performance of the cell edge users can be fairly increased. However, using FFR technique has a fatal side effect. In order to use different frequency partition among three sectors of outer cell, they can use only a third of the whole system bandwidth. Then, the reduction of available bandwidth reduces the system throughput directly. To solve this problem, we propose a new FFR method that allocates partially overlapped frequency partition to each sector of outer cell. And then, we suggest a proper overlapping ratio for practical cellular system.

• Membrane and Water Treatment
• /
• v.9 no.4
• /
• pp.211-220
• /
• 2018

Incorporating nano-materials in thin-film composite (TFC) membranes has been considered to be an approach to achieve higher membrane performance in various water treatment processes. This study investigated the rejection efficiency of three target compounds, i.e., reserpine, norfloxacin and tetracycline hydrochloride, by TFC membranes with different graphene oxide proportions. Graphene oxide (GO) was incorporated into the polyamide active layer of a TFC membrane via an interfacial polymerization (IP) reaction. The TFC membranes were characterized with FTIR, FE-SEM, AFM; in addition, the water contact angle measurements as well as the permeation and separation performance were evaluated. The prepared GO-TFC membranes exhibited a much higher flux ($3.11{\pm}0.04L/m2{\cdot}h{\cdot}bar$) than the pristine TFC membranes ($2.12{\pm}0.05L/m2{\cdot}h{\cdot}bar$) without sacrificing their foulant rejection abilities. At the same time, the GO-modified membrane appeared to be less sensitive to pH changes than the pure TFC membrane. A significant improvement in the anti-fouling property of the membrane was observed, which was ascribed to the favorable change in the membrane's hydrophilicity, surface morphology and surface charge through the addition of an appropriate amount of GO. This study predominantly improved the understanding of the different PA/GO membranes and outlined improved industrial applications of such membranes in the future.

• Journal of Korea Water Resources Association
• /
• v.35 no.2
• /
• pp.213-220
• /
• 2002

This reserch was focused upon experimental study for wastewater reuse and conducted to evaluate optimum operating conditions of rapid filtration process such as filter flow rate, filtration time and backwashing condition for reuse of secondary-treated effluent using the pilot plant installed in real wastewater treatment plant. Also, the experiment on treatment char-acteristics of coagulant-added activated sludge process was performed to compare with activated sludge succeeded to rapid filtration. As the filtration velocity was 100m/day, the filtration time of the rapid filter connected with activated sludge system was revealed to 40 hours. Backwashing of filter was conducted by water wash and air scour. The optimum backwashing time and backwash flow rate were 10min and 10LPM, respectively. The quantity of backwashing water of the rapid filter was about 2% of total treated water.