• IE interfaces
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• v.23 no.4
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• pp.311-318
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• 2010

In the daily multi-reservoir operating problem, monthly storage targets can be used as principal operational guidelines. In this study, we tested the use of a simple back-propagation Artificial Neural Network (ANN) model to derive monthly storage guideline for daily Coordinated Multi-reservoir Operating Model (CoMOM) of the Han-River basin. This approach is based on the belief that the optimum solution of the daily CoMOM has a good performance, and the ANN model trained with the results of daily CoMOM would produce effective monthly operating guidelines. The optimum results of daily CoMOM is used as the training set for the back-propagation ANN model, which is designed to derive monthly reservoir storage targets in the basin. For the input patterns of the ANN model, we adopted the ratios of initial storage of each dam to the storage of Paldang dam, ratios of monthly expected inflow of each dam to the total inflow of the whole basin, ratios of monthly demand at each dam to the total demand of the whole basin, ratio of total storage of the whole basin to the active storage of Paldang dam, and the ratio of total inflow of the whole basin to the active storage of the whole basin. And the output pattern of ANN model is the optimal final storages that are generated by the daily CoMOM. Then, we analyzed the performance of the ANN model by using a real-time simulation procedure for the multi-reservoir system of the Han-river basin, assuming that historical inflows from October 1st, 2004 to June 30th, 2007 (except July, August, September) were occurred. The simulation results showed that by utilizing the monthly storage target provided by the ANN model, we could reduce the spillages, increase hydropower generation, and secure more water at the end of the planning horizon compared to the historical records.

• Korean Journal of Construction Engineering and Management
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• v.11 no.1
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• pp.38-47
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• 2010

Builders in Korea are facing significant challenges in the midst of deteriorating market conditions resulting from recent financial crunch and slumping housing sales, etc. To address such changes in management landscape, enterprise organizations need to build an efficient corporate management organization than can ensure prompt and flexible response to changes in surroundings. However, most of them base their management organization on business type and volume due to insufficient understanding and analysis of organization. Top 30 construction companies in Korea have their own management organizations and business structures let alone different competitive edges and challenges. Therefore, this paper attempts to examine the current status of management and organization of construction companies to understand their operational achievements and organizational features in and effort to develop an efficient management strategy and provide inputs contributory to establishment of corporate management organization.

• Membrane and Water Treatment
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• v.9 no.4
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• pp.279-284
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• 2018

Membrane biofouling is a critical operational problem that hinders the rapid commercialization of MBRs. Quorum quenching (QQ) has been investigated widely to control membrane biofouling and is accepted as a promising anti-fouling strategy. Various QQ strategies based on bacterial and enzymatic agents have been identified and applied successfully. Whereas, this study aimed to compare indigenously isolated QQ strain i.e., Enterobacter cloaca with well reported Rhodococcus sp. BH4. Both bacterial species were immobilized in polymeric beads and introduced to two different MBRs keeping the overall beads to volume ratio as 1%. Efficiencies of these strains were monitored in terms of prolonging the membrane filtration cycle of MBR, release of extra-cellular polymeric substances, membrane resistivity measurements and mineralization of signal molecules and permeate quality. Indigenous strain (Enterobacter cloaca) was added to $QQ-MBR_E$ while Rhodococcus sp. BH4 was introduced to $QQ-MBR_R$. QQ bacterial embedded beads showed enhanced filtration cycles up to 1.4 and 2.3 times for $QQ-MBR_E$ and $QQ-MBR_R$ respectively as compared to control MBR (C-MBR). Soluble EPS concentration of 52 mg/L was observed in C-MBR while significantly lower EPS concentration of 20 and 10 mg/L was witnessed in $QQ-MBR_E$ and $QQ-MBR_R$, respectively. Therefore, substantial reduction in biofouling showed the effectiveness of indigenous strain.

• 모자간호학회지
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• v.4 no.1
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• pp.80-90
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• 1994

Concept analysis is a strategy that examines the attributes or characteristics of a concept. It is a formal linguistic exercise to determine those defining attributes. The basic purpose of concept analysis is to clarify ambiguous concepts in theory, and to propose a precise operational definition which reflects the theoretical base of the concept. The concept of maternal role is too broad and variable in expression, therefore there has been no authentic definition nor standard opinion for this concept. The purpose of this study is to clarify the concept of maternal role which in turn will help in the development of a theory of maternal role attainment. In order to analyze the concept of maternal role, much effort was extended to look up "maternal role" in various dictionaries and literature, but only a few cases were found which listed this terminology. Consultation on the meaning of "mother" and "role" separately was then done and consequently a definition of "maternal role" was obtained through concept analysis of these two words independently, finding their attributes and unifying them. The attributes of the concept of maternal role which was analyzed based on the steps of concept analysis by Walker & Avant (1988) are : 1) Women who have pregnancies 2) Women who have a child 3) Women who rear a child 4) Expected behavior according to social status 5) Learning through social cultures 6) Social interrelationships. The antecedents of the maternal role are : 1) women who are pregnant and deliver a baby, must keep in contact with their child. 2) Circumstances for childrearing must be provided. 3) Formation of self-concept as mother should be developed, cognitive activity, which is necessary for the nurturing activity, financial support and preparation of childrearing should be provided. And the consequences of the maternal role are : 1) Improvement 2) Changeability 3) Ambiguity 4) Stability Through this concept analysis, the concept of the maternal role is defined as "expected behavior by social interrelationships and learned nurturing behavior through social cultures."

• Journal of Korean Society of Archives and Records Management
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• v.18 no.3
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• pp.49-70
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• 2018

This paper proposes a cloud system model for incorporating the existing Records Management System (RMS), Archives Management System (AMS), and Central Archives Management System (CAMS) into a cloud-based national records management system. To do this, research on concrete and stepwise ways to transform AMS, including CAMS, into a cloud computing environment was carried out. This study developed a cloud system design strategy and goal model to integrate national records-related systems into a single cloud system to share and utilize information resources, manage them efficiently, and reduce costs. In particular, this study analyzed technical security and operational security that are exposed in the cloud environment and suggested measures to solve them. As a result, cloud computing technology can be applied to achieve low-cost and high-efficiency effects.

• Korean Journal of Construction Engineering and Management
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• v.5 no.2 s.18
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• pp.211-218
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• 2004

In a large owner organization, a program manager of multiple maintenance and remodeling projects has experienced increasing scale and complexity of coordinating the M/R projects with in-house technicians who belong to multiple trade shops. This paper proposes a dual-level hierarchical planning strategy that consists of a program master plan in the long-term horizon and a master construction schedule in an operational scheduling window. A rolling horizon approach to the program master plan is proposed to deal with the external uncertainty of unknown stream of project requests. A resource-constrained scheduling algorithm is developed to generate the master construction schedule in a scheduling window. During development of the algorithm, more emphasis is placed on long-term organizational resource continuity, especially flow management of program constraint resources, than ephemeral events of an individual activity and project. Monte Carlo simulation experiments of three scheduling windows are used to evaluate the relative performance of the proposed scheduling algorithm against three popular scheduling heuristics for resource-constrained multiple projects.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.137-144
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• 2007

In the year of 1980 and 2000, the Korean government institutionalized the Value Engineering methodology in the construction phase and the design phase respectively. While design-phase VE have been applied to construction industry actively, which was institutionalized 7 years ago, construction-phase VE have not been applied to industry frequently, although it was institutionalized 25 years ago. On the other hand, at the time of social demands for VE is increasing, it has been pointed out that VE should be compatible with the delivery system. And the time of VE study, the operational management of VE study, and the maintenance process of the result of the VE study also should be considered. In this study, a scheme to improve VE methodology in the construction industry is proposed based on the literature review and the data analysis of domestic and foreign state of VE.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.9
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• pp.746-756
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• 2013

The emitter geolocation method using the time difference of arrival (TDOA) and the frequency difference of arrival (FDOA) has more accurate performance comparing to the single TDOA or FDOA based method. The estimation performance varies with the sensor paring strategies, the deployment and velocities of the sensors. Therefore, to establish effective strategy on the electronic warfare system, it is required to analyze the relation between the estimation accuracy and the operational condition of sensors. However, in the conventional non-iterative method, the restriction of the deployment of sensors and the reference sensor exists. Therefore, we derive the emitter geolocation method based on a Gauss-Newton method which is available to apply to any various sensor pairs and the deployment and velocities of the sensors. In addition, simulation results are included to compare the performance of geolocation method according to the used measurements: the combined TDOA/FDOA, TDOA, and FDOA. Also, we present that the combined TDOA/FDOA method outperforms over single TDOA or FDOA on the estimation accuracy with the CEP plane.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.12
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• pp.1085-1092
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• 2012

Mobile communication systems define user state transition mechanisms in order to manage radio resources and battery power efficiently. In the state transition mechanism, a state with a higher energy consumption inherently offers a shorter access delay, so there is a tradeoff between the energy and delay performances. In this paper, we analyze the user state transition mechanism of UMTS by considering the bursty traffic attributes of mobile applications. We perform a numerical evaluation for both the energy consumption and the activation delay by Markov modeling of the state transition mechanism, and investigate their tradeoff relationship as functions of operational parameters. The resulting energy-delay tradeoff curves clearly show an achievable performance bound of the user state transition mechanism and also offer an optimal operation strategy to minimize the energy consumption while guaranteeing the delay requirement.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1991.06a
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• pp.45-48
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• 1991

This work aims to introduce the concept of microcomputer aided port design simulation methodology including the analysis of the mathematical models to be implemented and apply it to the Third Stage Busan Part Development Project. In the Busan case study the size of the proposed turning basin of the new terminal together with the operational stra-tegies of berthing and unberthing was examined In addition the safety of ships' entry and exit through the projection new breakwaters was as-certained. From the application of simulation to the Busan project it was found that the proposed dredging area was not sufficiently wide enough for a modelled container ship to perform A type unberthing (in which the ship turns to port as she monoeuvres away from No.1 berth with the ass-istance of tuges) especially in a strong easterly wind., It is therefore recommended that Busan pilots should be advised to use B type unberthing strategy in which the ship goes astern from No.1 berth to the turning area in front of No.2 berth(where the ship turns 180 degrees clockwise) especially when the wind is very strong. It is also recommended that a sea buoy be placed outside the new breakwaters as this was found to im-prove the safety of ship manoeuvres through the breakwaters significant-ly. Another recommendation is that the Korean Hydrodynamic Office carry out a detailed survey of the currents in the water area near the new breakwaters. once they have been constructed. In addition it is to be recommended that a current meter be placed at the recommended sea buoy pardised by erroneous current information