• Journal of Digital Convergence
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• v.16 no.12
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• pp.123-135
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• 2018

The objective of this paper is to investigate the issues related to the supply chain management in plant engineering industry, and propose the framework to improve the project efficiency. The preliminary case study shows that EPC's fragmented nature, lack of coordination and information sharing, and lack of proper risk and change management contribute to project delay and cost overrun. To examine the level of informatization and information sharing in supply chain, survey responses from the suppliers and subcontractors have been collected. The statistical results show that information sharing, early involvement in design process and awareness in SCM have influenced the level of collaboration, but supplier assessment and informatization have no impact on the collaboration. A conceptual model is proposed in order to facilitate the integration of design, procurement and construction functions. Implications from the study are also provided.

• Applied Chemistry for Engineering
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• v.32 no.3
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• pp.237-242
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• 2021

Simultaneous removal technologies of multi-pollutants such as particulate matters (PMs), NOx, SOx, VOCs and ammonia have received consistent attention due to the enhancement of pollutant abatement efficiency in addition to the stringent environmental regulation and emission standard. Pretreatment of insoluble NO by an ozone oxidation can be considered to be more effective route for saving space occupation as well as operation cost in comparison with that of traditional selective catalytic reduction (SCR) process. Moreover the primary advantage of ozone oxidation process is that the simultaneous removal with acidic gas including SOx is also available. Herein, we highlight recent studies of multi-pollutant abatement via ozone oxidation process and the promising research topics for better application in industrial sectors.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.05b
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• pp.93-96
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• 2009

This study is to examine a change of quality and a material performance of fiber reinforced cement composite for mass production. It is necessary to make Strain-hardening cementitious composite(SHCC) by batcher plant for ready-mixed concrete and use the performance of SHCC which made based on laboratory level. This study makes a comparative performance of press and mechanics that is the property of Strain-hardening by direct tension. In case of making by batcher plant. This experiment has demonstrated that even if it takes long after being mixed small and compared with the one which made based on laboratory, it has a tendency to be dissatisfied with fiver's dispersion and lower its performance of Strain-hardening. The reason why the material performance of SHCC for mass production went down is through SHCC that mixed sometimes matrix's viscosity and fiber's dispersion.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.4
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• pp.857-864
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• 2009

This study aimed at developing the two stage and dual filtration system. It has a sand + activated carbon layer above the underdrain system and a sand layer above the middledrain system for pretreatment. When retrofitting an old filter bed or designing a new one, this technology can substitute the existing sand filter bed without requiring a new site. In order to extend the filtering duration, the upper layer of the filter bed consists of the rapid sand filtration with large particles which pre-treats and removes coarse particles and turbidity matters. The middle layer has biological activated carbon(BAC) and granular activated carbon(GAC) to eliminate dissolved organic matters, disinfection by-products precursors etc. The lower layer consists of the sand filtration for the post filtering mode. In this study, a pilot plant of two stage and dual filtration system was operated for 4 months in the S water treatment plant in Kyounggi-Do. The stability of turbidity was maintained below 1NTU. The TOC, THMFP and HAAFP were removed about 90% by two stage and dual filtration system, which is almost 2 times higher than S WTP. From analysis result of HPC along the depth of activated carbon + sand layer at 2nd stage, microorganism was mostly not detected, however, increment of HPC was shown as it becomes deeper. It indicates that growth of microorganism is occurred at activated carbon layer.

• Korean Chemical Engineering Research
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• v.52 no.5
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• pp.592-602
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• 2014

In the Integrated Gasification Combined Cycle (IGCC), the stability of the gasifier has strong influences on the rest of the plant as it supplies the feed to the rest of the power generation system. In order to ensure a safe and stable operation of the entrained-flow gasifier and for protection of the gasifier wall from the high internal temperature, the solid slag layer thickness should be regulated tightly but its control is hampered by the lack of on-line measurement for it. In this study, a previously published dynamic simulation model of a Shell-type gasifier is reproduced and two different linear model predictive control strategies are simulated and compared for multivariable control of the entrained-flow gasifier. The first approach is to control a measured secondary variable as a surrogate to the unmeasured slag thickness. The control results of this approach depended strongly on the unmeasured disturbance type. In other words, the slag thickness could not be controlled tightly for a certain type of unmeasured disturbance. The second approach is to estimate the unmeasured slag thickness through the Kalman filter and to use the estimate to predict and control the slag thickness directly. Using the second approach, the slag thickness could be controlled well regardless of the type of unmeasured disturbances.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.487-491
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• 2006

As Korea has been industrialized high recently, the constructional plant part which is the major driving force to Korean economic growth is being developed. In spite of the great importance, there are many ill-prepared parts in EPC project management procedure, and working in practice of EPC project management procedure manual is not systematic. That is why the governmental progressive policy on the relevant technology and the establishment of EPC project management procedure are needed. This study was aimed to derive reform measures by analyzing problems of EPC project management procedure manuals which are in use at 13 large-sized construction companies currently. The reform measures which are based on the theory of PMI(Project Management Institute)'s PMBOK(Porjcet Management Body Of Knowledge) are about deriving administration factors to control the project, and EPC project administration factors are derived from the definition of CMAA(Construction Mangement Association of America). The reformed electronic EPC project management procedure manual system is set up by standardizing derived administration factors.

• Journal of the Korea Institute of Building Construction
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• v.11 no.6
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• pp.530-537
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• 2011

The purpose of this study is to examine material performance of fiber reinforced cement composite for mass production. It is necessary to manufacture SHCC(Strain Hardening Cement Composite) by batch plant for field application and mass production. For the study, a mock-up test of SHCC manufactured in the batch plant was conducted, and the performance was compared with SHCC manufactured in the laboratory. Assessment items were freshness and hardening properties. Specifically, direct tensile test machine was used for performance verification of SHCC. As a result, there was a tendency of less satisfactory fiber dispersion and performance of strain hardening compared with the performance of SHCC manufactured in the laboratory. To address this, dry mixing and mortar mixing time should be increased compared to laboratory mixing, and injection time of an agent such as a water reducing agent should be properly controlled according to mixing combination, or the capacity to secure dispersion and homogeneity of material.

• Korean Journal of Construction Engineering and Management
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• v.9 no.5
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• pp.149-158
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• 2008

Plant construction is being a motive power of national economic growth, because it is a higher value-added business which has enormous influence through other industry. But, plant projects management of the domestic company was poor. So, the development of EPC Business Process Management method has been encouraged. Therefore, this paper performed several researches for setting up the EPC Business Process Management Model for improving plant project management. And the details are as follows. First of all, this study collected the work procedure manuals of 12 large-sized international construction companies. Secondly, from the analyzing gathered EPC work procedure manuals, issues of work procedure manuals were analyzed and improvement plans were drawn out. Basis on this, This study presents a method to improve project management for EPC plant project. 'The Work Procedure Matrix for EPC Management' and 'Key Unit Works for EPC Management' were drawn out by using overseas construction management theories and international regulations. In addition, 'The EPC Business Process Management Models' reformed to the Business process method, that is the set of specifications, documents and procedures used to manage the EPC plant project. And it describes how the EPC work procedure manuals will be used. Finally, this study suggests the model of EPC Business Process Management System. The framework of Plant project management can be clarified by using 'The Work Procedure Matrix'. And 'Key Unit Works' are used to organize the work procedure needed to improve plant projects management. The results of this study will help to improve in project management efficiency for plant construction.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.4
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• pp.433-445
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• 2010

The aim of this study was to evaluate the fixation effect by connecting impression copings and to compare the three types of impression trays which were used in open tray impression technique. Experimental groups used 3 types of impression trays which are custom tray, plastic metal combination tray and polycarbonate stock tray. These three groups were subdivided into splinted and non-splinted impression copings group. The total number of experimental groups was six. 10 specimens were made for each group. We used 1-screw test, observing the specimen on which only one side abutment of reference framework was fixated with 20 Ncm. The gap between implant analogue and abutment of the other side was observed by stereo microscope. It was measured at 6 points in each specimen. Measuring value was selected when same result was revealed 3 times. Recorded data were statistically analyzed. Whether impression copings were splinted or not, there was no significant difference among custom tray group, plastic metal combination tray group, and polycarbonate stock tray group. Significant statistical difference in vertical fit discrepancy was found between splinted and non-splinted impression copings group with custom tray, plastic metal combination tray and polycarbonate stock tray (p<0.05).

• Composites Research
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• v.31 no.5
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• pp.227-237
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• 2018

In this paper, the design application for the lightweight and insulation of the manipulator of the mobile welding robot for the closed/narrow space is presented. A variety of robotic platforms have been developed for weld-worker using a welding robot outside a workpiece for welding work in a complex and narrow space such as a ship or an offshore plant. Normally, The development process of robots consists of machine development, electronic device development, control algorithm development and integration verification considering application environment and requirements. In order to develop the robustness of the welding robot, the lightweight design of the robot manipulator considering the environmental conditions was performed in the basic design of the robot platform. Also, The results of the robot selection and validation, analysis and testing for the insulation performance and cooling performance and the results of the research are shown.