• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.5
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• pp.609-616
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• 2018

The cargo handling system, which is composed of a fuel gas supply unit and cargo tank pressure control unit, is the second largest power consumer in a Liquefied Natural Gas (LNG) carrier. Because of recent enhancements in ship efficiency, the surplus boil-off gas that remains after supplying fuel gas for ship propulsion must be reliquefied or burned to regulate the cargo tank pressure. A full or partial liquefaction process can be applied to return the surplus gas to the cargo tank. The purpose of this study is to review the current partial liquefaction process for LNG carriers and develop new processes for reducing power consumption using exergy analysis. The developed partial liquefaction process was also compared with the full liquefaction process applicable to a LNG carrier with a varying boil-off gas composition and varying liquefaction amounts. An exergy analysis showed that the Joule-Thomson valve is the key component needed for improvements to the system, and that the proposed system showed an 8% enhancement relative to the current prevailing system. A comparison of the study results with a partial/full liquefaction process showed that power consumption is strongly affected by the returned liquefied amount.

• International Journal of Contents
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• v.13 no.3
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• pp.1-8
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• 2017

Rice plant numbers and density are key factors for yield and quality of rice grains. Precise and properly estimated rice plant numbers and density can assure high yield from rice fields. The main objective of this study was to automatically detect and count rice plants using images of usual field condition from an unmanned aerial vehicle (UAV). We proposed an automatic image processing method based on morphological operation and boundaries of the connected component to count rice plant numbers after transplanting. We converted RGB images to binary images and applied adaptive median filter to remove distortion and noises. Then we applied a morphological operation to the binary image and draw boundaries to the connected component to count rice plants using those images. The result reveals the algorithm can conduct a performance of 89% by the F-measure, corresponding to a Precision of 87% and a Recall of 91%. The best fit image gives a performance of 93% by the F-measure, corresponding to a Precision of 91% and a Recall of 96%. Comparison between the numbers of rice plants detected and counted by the naked eye and the numbers of rice plants found by the proposed method provided viable and acceptable results. The $R^2$ value was approximately 0.893.

• Journal of Environmental Science International
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• v.22 no.10
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• pp.1305-1316
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• 2013

A long-term wind resource map was made to provide the key design data for the 2.5 GW Korean West-South Offshore Wind Project, and its reliability was validated. A one-way dynamic downscaling of the MERRA reanalysis meteorological data of the Yeongwang-Gochang offshore was carried out using WindSim, a Computational Fluid Dynamics based wind resource mapping software, to establish a 33-year time series wind resource map of 100 m x 100 m spatial resolution and 1-hour interval temporal resolution from 1979 to 2012. The simulated wind resource map was validated by comparison with wind measurement data from the HeMOSU offshore meteorological tower, the Wangdeungdo Island meteorological tower, and the Gochang transmission tower on the nearby coastline, and the uncertainty due to long-term variability was analyzed. The long-term variability of the wind power was investigated in inter-annual, monthly, and daily units while the short-term variability was examined as the pattern of the coefficient of variation in hourly units. The results showed that the inter-annual variability had a maximum wind index variance of 22.3% while the short-term variability, i.e., the annual standard deviation of the hourly average wind power, was $0.041{\pm}0.001$, indicating steady variability.

• Journal of Korean Academy of Nursing Administration
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• v.15 no.3
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• pp.305-313
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• 2009

Purpose: This study was done to identify the current status of burnout research on Korean nurses and to suggest the directions for future research. Method: Fifty two articles between 1998 and 2007 were selected using the key words such as "Nurse" and "Burnout" from the database (RISS4U et al.). Results: 77.9% of studies were master's theses unpublished in the nursing journals. All studies were cross-sectional and therefore did not allow casual inference. Hospital nurses were the most common subjects (21 studies). The most frequently used burnout measurement instrument was the Burnout Measure, while the Maslach Burnout Inventory was used in only 6 studies. 55.7% of studies reported the average burnout score as higher than the middle level. Among individual factors, variables significantly correlated to burnout were age, position, work experience, coping, and personality. Some of job factors including shift work, workloads, job stress, and organizational commitment were also significantly related to burnout. There was very little discussion about the influence of organizational factors analyzed by unit or institution level. Conclusion: In Korea, the next phase of nurse burnout research needs to consider the measurement tool selection for the international comparison and longitudinal design to find more specific causal relationships.

• Journal of Technology Innovation
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• v.16 no.2
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• pp.125-145
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• 2008

The paper evaluates the Korean science, technology, and innovation policy(STIP) in terms of an individual firm. The firm is Viromed(Ltd), a new technology-based venture company in the field of biotechnology. The case is compared with the 'Hwang Project', which is known as a typical failure case in Korea. In order to evaluate the Korean STIP, we establish 6 areas, which are technological infrastructure, institutional infrastructure, human capital infrastructure, technology market, industrial base, and innovation networks. The study shows that the policy schemes relating with technological infrastructure, institutional infrastructure, human capital infrastructure, and industrial base play a positive role in the start-up, development and innovation of Viromed(Ltd). However, we can hardly find the role of Korean government in fostering the technology market, transferring the technological output to economic performance. Although the international networks with the British, American, and Japanese firms or investors were a key success factor of the growth of Viromed(Ltd), the role of the government in this policy area was not enough. As for the 'Hwang Project', we suggest that the government should consider the possibility of commercialization in choosing R&D projects and determining the size of financial aids. Since the evaluation of the Korean STIP is based on an individual firm, the results of the paper need to be confirmed by a systematic comparison with other cases or industries.

• International Journal of Contents
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• v.11 no.2
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• pp.15-19
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• 2015

In this paper, we propose an efficient document layout analysis algorithm that includes table detection. Typical methods of document layout analysis use the height and gap between words or columns. To correspond to the various styles and sizes of documents, we propose an algorithm that uses the mean value of the distance transform representing thickness and compare with components in the local area. With this algorithm, we combine a table detection algorithm using the same feature as that of the text classifier. Table candidates, separators, and big components are isolated from the image using Connected Component Analysis (CCA) and distance transform. The key idea of text classification is that the characteristics of the text parallel components that have a similar thickness and height. In order to estimate local similarity, we detect a text region using an adaptive searching window size. An improved adaptive run-length smoothing algorithm (ARLSA) was proposed to create the proper boundary of a text zone and non-text zone. Results from experiments on the ICDAR2009 page segmentation competition test set and our dataset demonstrate the superiority of our dataset through f-measure comparison with other algorithms.

• International Journal of Aerospace System Engineering
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• v.2 no.2
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• pp.58-61
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• 2015

Combustion instability in solid rocket motors is a long-term open problem since the first rockets were used. Based on the numerous previous studies, it is known that the limit cycle amplitude is one of the key characteristics of the nonlinear combustion instability in solid rocket motors. Flandro's extended energy balance corollary, aims to predict the limit cycle amplitude of complex, nonlinear pressure oscillations for rockets or air-breathing engines, and leads to a precise assessment of nonlinear combustion instability in solid rocket motors. However, based on the comparison with experimental data, it is revealed that the Flandro's method cannot accurately describe such a complex oscillatory pressure. Thus in this work we make modifications of the nonlinear term in the nonlinear wave equations which represents the interaction of different modes. Through this modified method, a numerical simulation of the cylindrical solid rocket has been carried out, and the simulated result consists well with the experimental data. It means that the added coefficient makes the nonlinear wave growth equations describe the experimental data better.

• Journal of Navigation and Port Research
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• v.41 no.5
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• pp.251-258
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• 2017

Shortage of trained seafarers is an issue, which many ship-owners are facing and, according to recent studies, the shortfall of both officers and rating will worsen in the next few years. The key role of seafarers is of fundamental importance in international trade, as they are the ones responsible for safely manning and operating ships. In developing countries, they also perform a strategic aspect in terms of contribution to GDP, mainly by earning foreign currency and increasing national consumption of goods and services. Myanmar is still considered a developing country with an economy, which has only recently started growing steady. It is also one of the major seafarers supplying nations and the contribution, which seafarers have on the national GDP may be particularly significant in comparison to other countries. This study aims at investigating seafarers' impact towards the Myanmar national economy. The paper describes the status of Myanmar seafarers, and the seafarers' current and forecasted impact towards the Myanmar economy through a regression model. The study concludes with recommendations to make Myanmar seafarers more competitive internationally and increase their economic contribution nationally.

• Journal of the Korean Society of School Health
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• v.24 no.2
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• pp.181-189
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• 2011

Purpose: The purpose of this study was to identify the trend of overseas school health indicators and to investigate indicators comparable internationally. Methods: Using the key words, school, health, indicators and policy through formal literature and web sites, the resources were used after the completeness of resources such as the presence of author, year published and place, and reproducibility was evaluated. Results: In overseas, the interest of school health indicators has increased gradually since 1960. Quality indicators as well as quantitative indicators are important as the good school health indicators. The overseas school health indicators have been very comprehensive, not only including students, but also including the expanded population such as school personnel, parents, family and community, process and outcomes, policies, social and cultural environment. The trend of school health research is from traditional issue-based to indicatorbased which makes comprehensive interpretation including development of school health service and life satisfaction. Among internationally comparable indicators, Health Behaviour in School-aged Children (HBSC) and Global School-based Student Health Survey (GSHS) were chiefly for students' health and behavior level, and the School Health Service Survey (SHS) was for school health service personnel and policy. Conclusion: Characteristics of overseas school health indicators were expanded population, and comprehensive and internationally comparable indicators. Therefore, Korea school health indicators need to be comprehensive using expanded population and qualitative indicators, and consider standardized indicators comparable internationally.

• International journal of steel structures
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• v.18 no.5
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• pp.1497-1507
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• 2018

Most of previous studies on fire resistance of restrained steel beams neglected creep effect due to lack of suitable creep model. This paper presents a finite element model (FEM) for accessing the fire resistance of restrained high strength Q460 steel beams by taking high temperature Norton creep model of steel into consideration. The validation of the established model is verified by comparing the axial force and deflection of restrained beams obtained by finite element analysis with test results. In order to explore the creep effect on fire response of restrained Q460 steel beams, the thermal axial force and deflection of the beams are also analyzed excluding creep effect. Results from comparison infer that creep plays a crucial role in fire response of restrained steel beam and neglecting the effect of creep may lead to unsafe design. A set of parametric studies are accomplished by using the calibrated FEM to evaluate the governed factors influencing fire response of restrained Q460 steel beams. The parametric studies indicate that load level, rotational restraint stiffness, span-depth ratio, heating rate and temperature distribution pattern are key factors in determining fire resistance of restrained Q460 steel beam. A simplified design approach to determine the moment capacity of restrained Q460 steel beams is proposed based on the parametric studies by considering creep effect.