• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2004.11a
• /
• pp.608-611
• /
• 2004

Efficiency of the construction process is one of the most important factors to project success. However efficiency is not well defined or measured in construction projects in general. More importantly, efficiency of the construction should be viewed through the life-cycle of the whole production system not in a single phase of the construction process. Therefore, this study defines the concept of efficiency and suggests the efficiency measurement model in construction. As a case study, the suggested model was applied to the curtain wall construction process of the high rise buildings as well.

• The KSFM Journal of Fluid Machinery
• /
• v.20 no.1
• /
• pp.41-47
• /
• 2017

This study aimed to analyze organic Rankine cycle(ORC) which recovers discarded heat from a gas turbine based combined cycle cogeneration(CC-cogen) plant in terms of both performance and economics. The nominal electric power of the CC-cogen plant is around $120MW_e$, and heat for district heating is $153MW_{th}$. The major purpose of this study is to compare various options in selecting heat source of the ORC. Three heat sources were compared. Case 1 uses the exhaust gas from the HRSG, which is purely wasted to environment in normal plant operation without ORC. Case 2 also uses the exhaust gas from the HRSG. On the other hand, in this case, the DH economizer, which is located at the end of the HRSG, does not operate. Case 3 generates power using some of the district heating water which is supplied to consumers. The estimated ORC power generation ranges between 0.3 to 2.3% of the power generation capacity of the CC-cogen plant. Overall, Case 3 is evaluated to be better than other two options in terms of system design flexibility and power generation capacity.

• Corrosion Science and Technology
• /
• v.3 no.4
• /
• pp.166-171
• /
• 2004

Recent developments in Bridge Management Systems (BMS) and in Life-Cycle Cost (LCC) of bridges, have raised the need for evaluation procedure of future condition (Deterioration) of a bridge. Predicting future deterioration is not an easy task due to limited past data to extrapolate from and also due to difficulty in measuring actual deterioration such as section loss of steel on an actual steel bridge. Also, increase in live load and reduction of resistance are random variables, thus a probabilistic approach should be adopted for determining the future deterioration. Due to difficulties in evaluation of future deterioration on steel bridges, accepting uncertainties within a reasonable error, a deterministic procedure using bridge condition rating can be a useful tool for projection of future condition of bridges to identify repair and maintenance needs. The object of this paper is to determine applicability of evaluating deterioration of steel bridge components based on Bridge condition ratings. Bridge condition ratings of bridge components show wide variation for bridges of same age and does not directly correlate well with the age of the bridge and/or deterioration of the bridge. High uncertainty can be reduced by breaking down the rating and by sensitivity analysis. From refined condition rating data, generalized deterioration profile of structures based on age can be derived. Examples are shown for sample bridges in USA. Approximately, 3,000 short to medium span steel bridges were listed in the inventory database. Results show wide variation of rating factors but by subdividing the Bridge condition ratings for various categories general deterioration profiles of steel bridges can be determined.

• Journal of Internet Computing and Services
• /
• v.22 no.6
• /
• pp.71-81
• /
• 2021

This paper examines the ongoing research on ways to improve cybersecurity during the entire life cycle of weapons systems applied in advanced countries such as the United States, analyzes restrictions on obtaining domestic weapons systems, and presents effective security evaluation measures. By consistently performing mission-based risk assessment in the cybersecurity test and evaluation plan suitable for domestic circumstances at all stages of acquisition, important information is provided to major decision-making organizations in a timely manner to support decision-making, and to respond to identified vulnerabilities in cybersecurity. It is proposed to set the rules of engagement so that the protection measures can be verified, and a simulated invasion is proposed. In addition, the proposed cybersecurity test and evaluation system was compared with the domestic weapon system test and evaluation. Through this, the mission-based risk assessment element was grafted into the cybersecurity test and evaluation system research conducted so far to identify risks in a timely manner between acquisition projects, thereby supplementing the capability to support major decision-making.

• Steel and Composite Structures
• /
• v.20 no.4
• /
• pp.913-930
• /
• 2016

It is common practice to use Reduced Web Beam Sections (RWBS) in steel moment resisting frames. Perforation of beam web in these members may cause stress and strain concentration around the opening area and facilitate ductile fracture under cyclic loading. This paper presents a numerical study on the cyclic fracture of these structural components. The considered connections are configured as T-shaped assemblies with beams of elongated circular perforations. The failure of specimens under Ultra Low Cycle Fatigue (ULCF) condition is simulated using Cyclic Void Growth Model (CVGM) which is a micromechanics based fracture model. In each model, CVGM fracture index is calculated based on the stress and strain time histories and then models with different opening configurations are compared based on the calculated fracture index. In addition to the global models, sub-models with refined mesh are used to evaluate fracture index around the beam to column weldment. Modeling techniques are validated using data from previous experiments. Results show that as the perforation size increases, opening corners experience greater fracture index. This is while as the opening size increases the maximum observed fracture index at the connection welds decreases. However, the initiation of fracture at connection welds occurs at lower drift angles compared to opening corners. Finally, a probabilistic framework is applied to CVGM in order to account for the uncertainties existing in the prediction of ductile fracture and results are discussed.

• Journal of Microbiology and Biotechnology
• /
• v.32 no.6
• /
• pp.718-729
• /
• 2022

Esophageal squamous cell carcinoma (ESCC) is the most common primary esophageal malignancy with poor prognosis. Here, due to the necessity for exploring potential therapies against ESCC, we obtained the gene expression data on ESCC from the TCGA and GEO databases. Venn diagram analysis was applied to identify common targets. The protein-protein interaction network was constructed by Cytoscape software, and the hub targets were extracted from the network via cytoHubba. The potential hub nodes as drug targets were found by pharmacophore-based virtual screening and molecular modeling, and the antitumor activity was evaluated through in vitro studies. A total of 364 differentially expressed genes (DEGs) in ESCC were identified. Pathway enrichment analyses suggested that most DEGs were mainly involved in the cell cycle. Three hub targets were retrieved, including CENPF, CCNA2 (cyclin A), and CCNB1 (cyclin B1), which were highly expressed in esophageal cancer and associated with prognosis. Moreover, amentoflavone, a promising drug candidate found by pharmacophore-based virtual screening, showed antiproliferative and proapoptotic effects and induced G1 in esophageal squamous carcinoma cells. Taken together, our findings suggested that amentoflavone could be a potential cell cycle inhibitor targeting cyclin B1, and is therefore expected to serve as a great therapeutic agent for treating esophageal squamous cell carcinoma.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2007.04a
• /
• pp.62-67
• /
• 2007

The research team for the virtual construction development was established with the support of Korea Ministry of Construction and Transportation, and KICTEP (Korea Institute of Construction and Transportation Technology Evaluation and Planning). Its aims are to develop system that is to improve productivity & quality, to create a higher value-added business, and to cultivate international competitiveness in the construction industry. The virtual construction system is a design, engineering, and construction management information system that allows the project participants to effectively share the information throughout the construction life cycle with the support of 3D and design information. To achieve this, the research team focuses on developing several systems. First, the team focuses on developing for the pre-planning, the structural engineering, MEP, and the 3D based estimation system. Second, they focus on developing a simulation system for the construction process planning and feasibility study with help of the virtual reality technologies. Third, they focus on developing the CPLM (Construction Project Life-cycle Management) system for managing construction project data, and the decision support system that makes the collaboration among the project participants based on 3D technologies and information. We also focus on developing the SDAI (Standard Data Access Interface), the localized guideline for 3D design, and a training program. In addition, we focus on developing the undeveloped area of the commercial system and building an environment that can support the communication and collaboration in the construction life-cycle rather than developing the existing and commercialized system.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.15 no.5
• /
• pp.113-123
• /
• 2011

LCC analysis is a method that coordinates with function evaluation for value improvement, rather than a separate one for cost evaluation. Although its accuracy is rising, materials and structural types developed or applied relatively recently have yet to obtain a sufficient maintenance profile DB, inducing reliability to reduce from difficulties in estimating maintenance records. Based on the above mentioned background, this paper presents the LCC methodology of coordinating functional intensification matters with cost for analysis on alternatives with difficulties in setting maintenance profile. Recently, steel plate bridge deck pavements are faced with problems such as plastic deformation due to the increase in heavy vehicles and traffic, promoting the development of a new compound pavement. This paper execute LCC analysis by mentioning case studies of SMA, Guss and PSMA pavements to include performance scale compared between alternatives as relative evaluation coefficients into the maintenance profile.

• Korean Journal of Construction Engineering and Management
• /
• v.8 no.2
• /
• pp.75-83
• /
• 2007

Recently, the Design-Build (DB) delivery method in public sector makes some argument by reason of the initial cost which is more higher than those of Design-Bid-Build (DBB). According to the results of pervious researches related to the performance evaluation of delivery method, DB can lead the reduction of project cycle time and also is superior to the traditional DBB in terms of construction quality. The performance on each delivery method could be generally evaluated by a project cost and a project cycle time as one of quantitative analyses, and also by construction quality as one of qualitative analyses. In most researches, the evaluation of performance level based on delivery methods has been evaluated by the degree of their satisfaction through the interview with owners. Therefore, this paper analyzed the design documents of construction projects delivered by traditional DBB and DB in bridge construction projects in order to measure design quality, constructability, maintainability, and etc. As an above-mentioned analyses, finally, this research shown that how much the difference of performance level is by each delivery method.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.24 no.12
• /
• pp.1625-1634
• /
• 2000

Verification of measurements is required for precise evaluation of turbine cycle performance in nuclear power plant. We assumed that initial acceptance data and design data of the plant could provide correlation information between performance data. The data can be used as sample sets for the correct estimation model of measurement value. The modeling was done practically by using regression model based on plant design data, plant acceptance data and verified plant performance data of domestic nuclear power plant. We can construct more robust performance analysis system for an operation nuclear power plant with this validation scheme.