• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.52-53
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• 2014

The Work Breakdown Structure (WBS) is a primary tool which provides a framework that defines clear scope of all deliverables throughout the project life cycle. Once the WBS is established in projects, it should allow project team members to measure and manage work performances by the WBS; further, it should provide a reference point when any work scope needs to be redefined. Based on the project information in the Progress and Performance Measurement System (PPMS) of UAE's Barakha Nuclear Power Plant (BNPP) projects, an attempt was made to develop a new WBS which provides hierarchical and systematical decomposition of the total work scope of NPP construction projects while avoiding from the preexistence concept in Korean NPP projects that the WBS is a combination of Physical Breakdown Structure (PBS) and Functional Breakdown Structure (FBS). The unique features of the new WBS are as follows: (1) defined the definition of each level of the WBS, (2) subdivided the WBS into 5 hierarchical levels, and (3) adopted globally used general coding structure. The new WBS provides a basic hierarchical structure for the project scope and can be used as a basic tool for schedule control, performance measurement, project status monitoring, and communication among project participants. In addition, by putting the Work Package (WP) under the WBS, the Earned Value Management System (EVMS) per WP can be utilized for the project.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.8
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• pp.996-1008
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• 1997

This paper describes a methodology and results for the analysis of a small steam injected gas turbine cogeneration system. A performance analysis program for the gas turbine engine is utilized with modifications required for the model of steam injection and the heat recovery steam generator (HRSG). The object of simulation is a simple cycle gas turbine engine under development which adopts a centrifugal compressor. The analysis is based on the off-design operation of the gas turbine and the compressor performance map is utilized. Analyses are carried out with the injection ratio as the main parameter. The effect of steam injection on the power and efficiency of gas turbine and cogeneration capacity is investigated. Also presented is the variation in the main operating parameters inside the HRSG. Remarkable reduction in NOx generation by steam injection is confirmed. In addition, it is observed that for the 100% power operation the temperature of the cooled first nozzle blade decreases by 100.deg. C at full steam injection, which seems to have a favorable effect on the engine life time.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.4
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• pp.12-23
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• 2014

The O&M (Operation and Maintenance) phase of offshore plants with a long life cycle requires heavy charges and more efforts than the construction phase, and the occurrence of an accident of an offshore plant causes catastrophic damage. So previous studies have focused on the development of advanced maintenance system to avoid unexpected failures. Nowadays due to the emerging ICTs (Information Communication Technologies) and sensor technologies, it is possible to gather the status data of equipment and send health monitoring data to administrator of an offshore plant in a real time way, which leads to having much concern on the condition based maintenance policy. In this study, we have reviewed previous studies associated with CBM (Condition-Based Maintenance) of offshore plants, and introduced an algorithm predicting the next failure time of the compressor which is one of essential mechanical devices in LNG FPSO (Liquefied Natural Gas Floating Production Storage and Offloading vessel). To develop the algorithm, continuous time Markov model is applied based on gathered vibration data.

• Journal of Aerospace System Engineering
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• v.1 no.4
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• pp.37-41
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• 2007

Labyrinth seal is most common way to protect the bearings installed in Reaction wheel. In spite of wide applications, no such research was found about the sealing utility of the Labyrinth seal in the condition of vacuum and high temperature. In this research, we tried to verify the utility of Labyrinth seal. Numerical analysis had been executed to predict the benefit of the Labyrinth seal and also experiments were performed to verify the utilization. Two Bearings were installed at the vacuum chamber, one was assembled with Labyrinth seal and the other was stand alone. After executing the vacuum test, it was found to be the stand alone bearing had lost more weight than the one that was assembled with the labyrinth seal. In this result, it is verified that the Labyrinth seal has useful function to preserve the lubricant that affects to the life-cycle of the Bearing.

• Journal of Electrical Engineering and Technology
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• v.11 no.4
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• pp.869-877
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• 2016

Necessity has compelled man to improve upon the art of tapping wind energy for power generation; an apt reliever of strain exerted on the non-renewable fossil fuel. The power generation in a Wind Farm (WF) depends on site and wind velocity which varies with time and season which in turn determine wind power modeling. It implies, the development of an accurate wind speed model to predict wind power fluctuations at a particular site is significant. In this paper, Box-Jenkins ARIMA (Auto Regressive Integrated Moving Average) time series model for wind speed is developed for a 99MW wind farm in the southern region of India. Because of the uncertainty in wind power developed, the economic viability and reliability of power generation is significant. Life Cycle Costing (LCC) method is used to determine the economic viability of WF generated power. Reliability models of WF are developed with the help of load curve of the utility grid and Capacity Outage Probability Table (COPT). ARIMA wind speed model is used for developing COPT. The values of annual reliability indices and variations of risk index of the WF with system peak load are calculated. Such reliability models of large WF can be used in generation system planning.

• Korean Journal of Environmental Agriculture
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• v.32 no.4
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• pp.366-368
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• 2013

BACKGROUND: Composting is the most frequently used waste management process for animal manure in Korea's livestock industry. In the composting process, a large amount of nitrogen (N) is volatilized to the atmosphere as amonia ($NH_3$). However, quantitative information of $NH_3$ emission from composting of liquid manure is required to obtain emission factors for management of livestock manure in Korea. METHODS AND RESULTS: To evaluate the $NH_3$ emission from composting of liquid manure affected by aeration, we conducted composting of liquid pig manure with three forced aeration systems. The aeration conditions were continuous (A60), cycle of 30 min aeration and 30 min pause (A30S30) and without aeration(A0). All treatments were aerated 12 hour per day with these aeration systems. The total ratio of $NH_3$ volatilization loss to total N content in liquid manure throughout composting period was estimated to 19.9% for A0 treatment, 25.9% for A30S30 treatment and 36.3% for A60 treatment. The A30S30 and A60 aeration systems increased $NH_3$ volatilization by 30.2 and 82.3% compared with systems without forced aeration. CONCLUSION(S): Ammonia emission during liquid pig manure composting was highly affected by forced aeration. The development of liquid pig manure composting systems with forced aeration would be considered both reducing ammonia emission and efficiency of composting.

• Development and Reproduction
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• v.16 no.1
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• pp.59-67
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• 2012

Previously, we found that $Zap70$ (Zeta-chain-associated protein kinase) expressed in the mouse oocytes and played significant role in completion of meiosis specifically at MI-MII (metaphase I-II) transition. Microinjection of $Zap70$ dsRNA into the cytoplasm of germinal vesicle oocyte resulted in MI arrest, and exhibited abnormalities in their spindles and chromosome configurations. The purpose of this study was to determine the mechanisms of action of $Zap70$ in oocyte maturation by evaluating downstream signal networking after $Zap70$ RNAi (RNA interference). The probe hybridization and data analysis were used by Affymetrix Gene Chip Mouse Genome 430 2.0 array and GenPlex 3.0 (ISTECH, Korea) software, respectively. Total 1,152 genes were up (n=366) and down (n=786) regulated after $Zap70$ RNAi. Among those genes changed, we confirmed the expressional changes of the genes involved in the regulation of actin cytoskeleton and MAPK (mitogen-activated protein kinase) signaling pathway, since the phenotypes of $Zap70$ RNAi in oocytes were found in the changes in the chromosome separation and spindle structures. We confirmed the changes in gene expression in the actin skeletal system as well as in the MAPK signaling pathway, and concluded that these changes are main cause of the aberrant chromosome arrangement and abnormal spindles after $Zap70$ RNAi.

• Journal of the Korea Society for Simulation
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• v.22 no.4
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• pp.29-38
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• 2013

Modeling and simulation technology is being used in various fields. Especially in the field of military, Simulation-Based Acquisition (SBA) is recognized as a essential policy. To effectively carry out SBA, modeling and simulation techniques should be applied in the whole life-cycle for the weapon system development, and the framework and tools which can help the rapid component development and reusability are needed. In this research, we use the simulation framework based on modeling formalism for enhancement of reusability and a GUI-based modeling environment for rapid M&S component development. The Proposed framework can act as plug-in components on the basis of XML-based object model, so that the flexible design is possible for the change of the model and simulation structure. In addition, our methods are effective to implement the functions for supporting simulation such as the model data logging and communication with external systems. In this paper, we describe an architecture and functions for the framework and tools.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2744-2748
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• 2015

This paper analyzes the effect on productivity by measuring Function Point per MM(man-month) in a software development project and code inspection which performed in Agile methodology, and introduce the method of applying MDA/MDD technology in the e-government standard framework project. MDA/MDD which recently raising its head is technology that increase software development productivity through automatic transformation form abstract model into lower abstract model, or from model to code. but, many Lessons obtained through the case studies, the analysis suggests a limited effect measurements. In this study, efficient development methodology and utilizing a e-government framework to measure the effectiveness of the MDD to the new measures through a case study applied to real information system development process. In addition to, managing information modeling through integrated repository presents a traceability and visibility.

• Journal of Aerospace System Engineering
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• v.12 no.5
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• pp.76-88
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• 2018

Space agencies such as NASA, ESA, and the US military provide guidelines and standards for PA(product assurance) requirements and plans. In recent years, major satellite manufacturers around the world have been mitigating PA requirements and processes by tailoring. PA tailoring has been implemented to improve the cost and schedule efficiency. PA tailoring can be accomplished based on various factors such as mission, classification of mission risk, complexity, development cost, life cycle, etc. In this study, PA tasks according to the mission risk classification proposed by NASA are investigated, and the tailoring method is suggested for the optimization of the development cost and schedule. In particular, the classification of mission risk for the satellites under development or operation in Korea is performed, and PA characteristics in accordance with mission risk are analyzed.