• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.568-572
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• 2001

An industrial vibratory conveyor system is devised for large-scale feeding by the low-power, using natural frequency of the system. The important thing in this system is to determine the natural frequency and to drive by it. The purpose of this study is to build up reliance on the system with changing of element parameters for vibration characteristics of balancing type vibratory conveyor by using F.E.M. modeling. For investigating the natural frequency, modal testing is performed by using impact hammer, accelerometer and LMS/Vibration Analysis System. Experimental results are compared with F.E.M results. The results of the comparisons within the errors of less than 2 percent can verify the reliability of the F.E.M. analysis of the system. Also we can verify that the characteristics of natural frequency have linearly decreased(-6%) as adding the mass($50{\sim}600kg$). We can find that controlling driving frequency is necessary for triggering the natural frequency, but natural frequency is less affected by adding the mass on the balancing weight.

• ALGAE
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• 제21권1호
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• pp.1-10
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• 2006

Genomic data is accumulating in public database at an unprecedented rate. Although presently dominated by the sequences of metazoan, plant, parasitic, and picoeukaryotic taxa, both expressed sequence tag (EST) and complete genomes of free-living algae are also slowly appearing. This wealth of information offers the opportunity to clarify many long-standing issues in algal and plant evolution such as the contribution of the plastid endosymbiont to nuclear genome evolution using the tools of comparative genomics and multi-gene phylogenetics. A particularly powerful approach for the automated analysis of genome data from multiple taxa is termed phylogenomics. Phylogenomics is the convergence of genomics science (the study of the function and structure of genes and genomes) and molecular phylogenetics (the study of the hierarchical evolutionary relationships among organisms, their genes and genomes). The use of phylogenetics to drive comparative genome analyses has facilitated the reconstruction of the evolutionary history of genes, gene families, and organisms. Here we survey the available genome data, introduce phylogenomic pipelines, and review some initial results of phylogenomic analyses of algal genome data.

• International Journal of Reliability and Applications
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• 제10권2호
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• pp.89-99
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• 2009

Oriented Strand Board (OSB) is an important engineered wood product used in housing construction which has a lower environmental impact or "carbon footprint." In this paper, reliability and statistical tools are applied to gain insights on the strand thickness of OSB panels. An OSB panel consists of several hundred wood strands that are resinated and pressed. The variability of OSB strand thickness for six manufacturers in the Eastern United States is examined as a whole, as well as individually. Little research exists on OSB strand thickness across mills even though strand thickness variability has been documented in laboratory experiments to greatly influence the dimensional stability of OSB panels. Our aims are to quantify and characterize strand thickness, plus apply reliability techniques, such as Kaplan-Meier curves, to characterize the probability of strand thickness. We further explore graphically and statistically the thickness of the strands.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.792-800
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• 2007

The annual power cost for Seoul metro operations is about 65.5 billion won, of which rail motors account for 60% among total power consumptions. It is expected that the power consumption would increase because of global warming, future high electric equipments demands, etc. To reduce these consumptions, it is necessary to analyze the transportation demands of passengers, arrange the power-saving driving environments, respond flexible vehicles service, and improve how to drive vehicles. These method to reduce power consumption for rail motors can lead to improve the Seoul metro management. In this research, the improvement plan is derived by collecting and analyzing the data for total 33 power consumptions factors, screening top 10 factors by priority and impact, establishing each hypothesis to execute correlation and recursion analyses. As a result of 4 items research among top 10 affected factors, the power consumption for rail motors in 2006 is effectively reduced; the power usage is down with 13,870 kwh, from 531,539 kwh to 517,669 kwh, and the cost is down with 1,026 million won, from 39, 334 million won to 38,308 million won.

• Nuclear Engineering and Technology
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• 제49권2호
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• pp.327-334
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• 2017

Common-cause failure (CCF) events can significantly impact the availability of safety systems of nuclear power plants. For this reason, the International Common Cause Data Exchange (ICDE) project was initiated by several countries in 1994. Since 1997 it has been operated within the Organisation for Economic Co-operation and Development (OECD)/Nuclear Energy Agency (NEA) framework and has successfully been operated over six consecutive terms (the current term being 2015-2017). The ICDE project allows multiple countries to collaborate and exchange CCF data to enhance the quality of risk analyses, which include CCF modeling. As CCF events are typically rare, most countries do not experience enough CCF events to perform meaningful analyses. Data combined from several countries, however, have yielded sufficient data for more rigorous analyses. The ICDE project has meanwhile published 11 reports on the collection and analysis of CCF events of specific component types (centrifugal pumps, emergency diesel generators, motor operated valves, safety and relief valves, check valves, circuit breakers, level measurement, control rod drive assemblies, and heat exchangers) and two topical reports. This paper presents recent activities and lessons learnt from the data collection and the results of topical analysis on emergency diesel generator CCF impacting entire exposed population.

• 드라이브 ㆍ 컨트롤
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• 제12권4호
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• pp.54-59
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• 2015

Due to the tendency to use high speed pneumatic cylinders to improve productivity, cushioning devices are adopted to decelerate the piston motion of pneumatic cylinders to reduce noise, vibration, and impact. This paper presents a comparison of the cushion characteristics of a high speed pneumatic cylinder with a relief valve type cushioning device. The system parameters selected are the damping coefficient, Coulomb friction, heat transfer coefficient, and cracking pressure of the relief valve in the air cushioning device. The integral of the time multiplied square error (ITSE) is used to quantitative measure the cushioning performance to assess the effect of varying these. The cushioning performance achieved good results when the ITSE is a minimum value. In a comparison of the piston displacement and velocity with the variations in system parameters, the heat transfer coefficients are not as significantly affected as the other. Also, the cracking pressure of the relief valve is mainly affected by the pressure and temperature in the cushion chamber.

• 한국항해항만학회지
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• 제37권5호
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• pp.471-480
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• 2013

Pay-for-performance plans are some of widely used human resource practices in many firms, including shipbuilding, for productivity and motivational improvement purposes. Such plans play an important role in industries that are highly labor-intensive, and where effective management of human resources is critical to business operations, such as the shipbuilding industry. Those practices can have large impact on employee performance and ultimately company competitiveness. Research studies that show how such incentive plans improve productivity and reported pattern of adoption by firms have spurred the use and adoption in many firms. However, there are also researchers who point out that there are negative consequences to using incentive plans. Therefore it is important for companies to carefully consider the practices they use. In this paper, I discuss research findings that support the practices and critical viewpoints related to pay-for-performance plans. Research findings from Korean literature are, then, discussed. The shipbuilding industry is chosen because proper human resource management is critical in reducing turnover and increasing employee satisfaction. Through a shipbuilding company case, problems related to using pay-for-performance incentive plans and how they affect work-related issues of employee morale, cooperation, and teamwork will be discussed. While positive aspects have been emphasized to drive greater adoption among firms, the resulting consequences of the pay plans need to be seriously considered and improvements upon the plans made by firms. Improvement suggestions are discussed in the conclusions and implications.

• The Journal of Asian Finance, Economics and Business
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• 제7권5호
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• pp.73-80
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• 2020

Tax is the main revenue of Government, so fighting tax evasion and sustainable growth have been the primary macroeconomic goals being pursued by every developing country, Vietnam included. The existence and development of the shadow economic sector are synonymous with the national budget losing out. In Vietnam, foreign direct investment projects do not promote economic growth and is also a sector that gives way to tax evasion.The purpose of this study is to investigate the impact of foreign direct investment, the quality of the informal institution on the size of the shadow economy in Vietnam, during the period 1991-2015. By applying the Autoregressive Distributed Lag approach and Toda and Yamamoto test, we found evidence to conclude that the quality of the informal institution harms the size of the shadow economy. The results of the causality test show that there is a unidirectional causality running from the shadow economy and the quality of the informal institution to foreign direct investment attraction in Vietnam. Political solutions need to be implemented carefully to counter the harmful effects of the shadow economy. Policymakers should adopt several economic policies to improve the 'human capital' and drive the shadow economy into the formal economy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권2호
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• pp.684-702
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• 2016

The changes new technologies have brought to banking over the past decade are enormous in their impact on the ways of doing business and providing customer services, most notably in the areas of customer service channels. Banks have been trying to move away from the traditional, branch-based and costly staff-assisted channels toward self-assisted channels, i.e. internet banking and mobile banking, to drive down costs and improve customer loyalty. How internet and mobile have reshaped the user experience of banking service channel? To provide valuable insights for this question, this research investigates and compares customer's channel choice behavior and profit changes from bank's branch closure. Applying the propensity scoring matching method, the results of analysis demonstrates that the mobile channel can be a realistic alternative to conventional branches. Also, the reserch result shows banks can reduce conventional branches while experiencing a positive implications on their profits from the customers. Another significant implication from the research is, to accelerate the shift to digital channels, banks need to put more efforts on developing functions in the mobile channel that will allow friendly interaction with customers and consultation, such as video consultation, interactive chat, and location-based product recommendation.

• Safety and Health at Work
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• 제4권2호
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• pp.87-94
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• 2013

Background: In times of continuous change and volatile markets, organizations are increasingly characterized by downsizing, work intensification, and resource rationalization. This has resulted in diversification, and the emergence of newrisks within the field of occupational health and safety, with an important impact. This paper focuses on one such type of risk in the modern workplace-psychosocial risks. The current study aimed to explore stakeholder perspectives, regarding the extent to which psychosocial risks are incorporated into strategic risk management practices, at both the business and policy level. Methods: Semi-structured interviews were conducted with 14 professionals, representing employer, expert, policy maker, and trade union stakeholder perspectives. Results: It was found that the majority of organizations do not sufficiently, if at all, understand and incorporate psychosocial risks into strategic decision making, whereby the key barrier related to practical difficulties of not knowing how to manage psychosocial risks adequately. Conclusion: The study found that there is a need to close the gap between policy and practice on a number of levels. Future recommendations comprise a policy framework and infrastructure underpinned by educational initiatives, partnerships, and networks to drive a shift in attitudes toward recognizing the duality of the concept of risk (including both potential negative and positive outcomes) and moving beyond simple regulatory compliance.