• International Journal of Naval Architecture and Ocean Engineering
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• 제6권2호
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• pp.471-483
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• 2014

Since 2009 of global financial crisis, shipbuilding industry has undergone hard times seriously. After such a long depression, the latest global shipping market index shows that the economic recovery of global shipbuilding market is underway. Especially, nations with enormous resources are going to increase their productivity or expanding their shipyards to accommodate a large amount of orders expected in the near future. However, few commercial projects have been carried out for the practical shipyard layout designs even though those can be good commercial opportunities for shipbuilding engineers. Shipbuilding starts with a shipyard construction with a large scale investment initially. Shipyard design and the equipment layout problem, which is directly linked to the productivity of ship production, is an important issue in the production planning of mass production of ships. In many cases, shipbuilding yard design has relied on the experience of the internal engineer, resulting in sporadic and poorly organized processes. Consequently, economic losses and the trial and error involved in such a design process are inevitable problems. The starting point of shipyard construction is to design a shipyard layout. Four kinds of engineering parts required for the shipyard layout design and construction. Those are civil engineering, building engineering, utility engineering and production layout engineering. Among these parts, production layout engineering is most important because its result is used as a foundation of the other engineering parts, and also, determines the shipyard capacity in the shipyard lifecycle. In this paper, the background of shipbuilding industry is explained in terms of engineering works for the recognition of the macro trend. Nextly, preliminary design methods and related case study is introduced briefly by referencing the previous research. Lastly, the designed work of layout design is validated using the computer simulation technology.

• 보건의료기술평가
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• 제6권2호
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• pp.123-132
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• 2018

Objectives: Maternal morbidity and mortality are important healthcare issues. However there have been few studies on cost of illness (COI) from maternal disorders. This study aimed to estimate the COI due to maternal disorders in Korea. Methods: By reviewing previous studies and consulting expert we determined the scope of maternal disorders. We operationally defined maternal disorders as maternal hemorrhage, maternal sepsis, hypertensive disorders of pregnancy, obstructed labor, and abortion for maternal disorders. The reference period of this study is the year 2015. Main source of data were the National Health Insurance Service claims data, cause of death statistics from the Korea National Statistical Office, and the Korea Health Panel study. We classified the total costs into direct and indirect costs. The direct costs cover healthcare costs and non-healthcare costs. The indirect costs consist of productivity losses due to morbidity and premature death. Results: The cost of maternal disorders in 2015 was 229.7 billion won. The direct and indirect costs of maternal disorders were 165.2 billion won and 64.5 billion won respectively. The largest cost item for maternal disorders was healthcare cost (138.3 billion won, 60.2%). By age groups, the COI in 30-39 years old women were the highest (165.1 billion won, 71.9%). Abortion was the disorder with the highest COI among maternal disorders (71.9 billion won, 31.3%). Conclusion: The COI due to maternal disorders in Korea is quite substantial. Economic burden of maternal disorder increased when being compared with the year 2012 data despite the continued low birth rate in Korea. Therefore, it is necessary to continuously monitor the social costs of the maternal disorders in Korea.

• Mycobiology
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• 제42권1호
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• pp.66-72
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• 2014

Roselle (Hibiscus sabdariffa L.) family Malvaceae is an important crop used in food, cosmetics and pharmaceutics industries. Roselle is cultivated mainly in Upper Egypt (Qena and Aswan governorates) producing 94% of total production. Root rot disease of roselle is one of the most important diseases that attack both seedlings and adult plants causing serious losses in crop productivity and quality. The main objective of the present study is to identify and characterize pathogens associated with root rot and wilt symptoms of roselle in Qena, Upper Egypt and evaluate their pathogenicity under greenhouse and field condition. Fusarium oxysporum, Macrophomina phaseolina, Fusarium solani, Fusarium equiseti and Fusarium semitectum were isolated from the natural root rot diseases in roselle. All isolated fungi were morphologically characterized and varied in their pathogenic potentialities. They could attack roselle plants causing damping-off and root rot/wilt diseases in different pathogenicity tests. The highest pathogenicity was caused by F. oxysporum and M. phaseolina followed by F. solani. The least pathogenic fungi were F. equiseti followed by F. semitectum. It obviously noted that Baladi roselle cultivar was more susceptible to infection with all tested fungi than Sobhia 17 under greenhouse and field conditions. This is the first report of fungal pathogens causing root rot and vascular wilt in roselle in Upper Egypt.

• Journal of international Conference on Electrical Machines and Systems
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• 제3권4호
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• pp.428-432
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• 2014

Rotating machines are an integral part of large electrical power machinery in most of the industries. Any degradation or outages in the rotating electric machinery can result in significant losses in productivity. It is critical to monitor the equipment for any degradation's so that it can serve as an early warning for adequate maintenance activities and repair. Prior research and field studies have indicated that the rotating machines have a particular type of signal structure during the initial start-up transient. A machine performance can be studied based on the effect of degradation in signal parameters. In this paper a data-acquisition system and the FFT algorithm has been design and model using the MATLAB and Simulink. The implementation had been carried out on the TMS320 DSP Processor and various testing and verification of the machine performance had been carried out. The results show good agreement with expected results for both simulated and real-time data. The real-time data from AC water pumps which have rotating motors built-in were collected and analysed. The FFT algorithm provides frequency response and based on this frequency response performance of the machine had been measured.The FFT algorithm provides only approximation about the machine performances.

• ALGAE
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• 제35권3호
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• pp.237-252
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• 2020

Temperate rocky reefs dominated by the giant kelp, Macrocystis pyrifera, support diverse assemblages of benthic macroalgae that provide a suite of ecosystem services, including high rates of primary production in aquatic ecosystems. These forests and the benthic macroalgae that inhabit them are facing both short-term losses and long-term declines throughout much of their range in the eastern Pacific Ocean. Here, we quantified patterns of benthic macroalgal biomass and irradiance on rocky reefs that had intact kelp forests and nearby reefs where the benthic macroalgae had been lost due to deforestation at three sites along the California, USA and Baja California, MEX coasts during the springs and summers of 2017 and 2018. We then modeled how the loss of macroalgae from these reefs impacted net benthic productivity using species-specific, mass-dependent rates of photosynthesis and respiration that we measured in the laboratory. Our results show that the macroalgal assemblages at these sites were dominated by a few species of stipitate kelps and fleshy red algae whose relative abundances were spatially and temporally variable, and which exhibited variable rates of photosynthesis and respiration. Together, our model estimates that the dominant macroalgae on these reefs contribute 15 to 4,300 mg C m^-2 d^-1 to net benthic primary production, and that this is driven primarily by a few dominant taxa that have large biomasses and high rates of photosynthesis and / or respiration. Consequently, we propose that the loss of these macroalgae results in the loss of an important contribution to primary production and overall ecosystem function.

• 한국농공학회논문집
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• 제48권6호
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• pp.17-28
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• 2006

We propose an Agricultural Infrastructure Expansion Plan (AIEP) for North Korea following unification from the standpoint of a united Korea's social stability. We predict the food demand after unification, according to four different development scenarios based on the AIEP. These scenarios include meeting a self-sufficient level in the staple food crop, satisfying long-term food supply and demand for the North Korean people, achieving a level of North Korean food consumption comparable to that of South Korea, and maintaining productivity to stabilize of North Korea's rural society. We present the results of a 'benefit-cost' analysis in meeting the production targets of predicted food demands after unification from a civil engineering perspective. We found that the estimated total costs would range from 15.2 to 43.0 billion dollars depending on the particular AIEP scenario. In our analysis, all of the four scenarios presented above demonstrated a high degree of economic validity. We conclude that the AIEP is a necessary and economically valid project for a united Korea's future because it would forestall the collapse of North Korea's rural communities, thereby preventing tremendous economic losses upon unification.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.851_852
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• 2009

Shrink fitting which is assembling process to fix stator core on the motor frame is widely used at the mass production line of motors because of cost and productivity. This process produces compressive stress on a stator core, which causes negative effect for example, core and copper losses on motor performance. Magnetic properties of electrical steel are effected by both compressive and tensile and thermal stresses. Electromagnetic field analysis is considered one of the effective process since one can predict motor performance including core loss precisely. This method can consider non linear magnetic property with magnetic saturation which is typical electrical steel behavior. However this method is strongly depended on non linear magnetic data, one may have different calculation result whether considering mechanical stress or not. This study describes magnetic field analysis of a motor considering mechanical stress from shrink fitting. Analysis results are compared with each stress-free and stressed condition.

• International Journal of Reliability and Applications
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• 제1권1호
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• pp.1-14
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• 2000

The global marketplace is highly competitive and organisations, who want to survive long-term, have to continuously improve, change and adapt in response to market demands. These improvements should focus on cost cutting, increasing productivity levels and quality and guaranteeing deliveries in order to satisfy customers. Total Productive Maintenance (TPM) is one method, which can be used to achieve these goals. TPM is a change management approach that involves employees from both production and maintenance departments. The purpose is to eliminate major production losses by introducing a program of continuous and systematic improvements to production equipment. TPM should be developed and expanded to embrace the whole organisation and all employees should be involved in the process as members of improvement teams. This paper gives a short description of the development of TPM and the TPM implementation process. Findings are reported from a case study in which one of the authors had the possibility of following and guiding a company through their TPM implementation. The implementation process takes several years and the research has focused on the initial three years. The study demonstrates that driving forces, obstacles and difficulties often are dependent on the organisation, its managers and the individual employees.

• 농업과학연구
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• 제37권3호
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• pp.413-433
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• 2010

South Dakota is an important agricultural state in the United States with annual cash receipts from agricultural products exceeding $9 billion dollars. This production is possible because of large areas of productive soils. This publication describes the general characteristics and qualities of the major soil groups recognized in South Dakota. The soil forming factors are briefly described, soil classification is introduced, and the genesis of typical Udalf and Ustoll soils are discussed. Soil management issues impacting the use of SD soils are considered. Long-term (>70 yrs) cultivation has significantly reduced surface soil organic carbon levels (>30% reduction) when compared to non-cultivated soil. Soil test phosphorus levels significantly increased in cultivated fields due to commercial P fertilization. The major long-term production problems for SD soils are conservation of soil moisture, organic matter and nitrogen losses, fertility management, and wind and water erosion control.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.1504-1511
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• 2005

The efficiency of the hydraulic transport of soil-water mixtures is an important factor in designing and operating a pump & pipeline system and is directly connected with dredging cost and working period. However, the hydraulic transport mechanism in the slurry flow inside the pipeline such as frictional losses, specific energy consumption, deposition velocity has not been well established. In this study a new dredging test loop system was designed and built. It is composed of a slurry pipeline with pipes of different diameters, a centrifugal slurry pump and a diesel engine connected with the slurry pump. and equipped with modern measuring facilities that enable to measure all important characteristics of a transportation system. The objective of this paper is to discuss the efficiency of the hydraulic transport of the Jumoonjin sand-water mixtures in the dredging test loop and to present simple equations induced from the test results of the loop that can express the transport product and the transport productivity.