• Journal of Korean Society of Coastal and Ocean Engineers
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• v.27 no.2
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• pp.94-104
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• 2015

Population and urban development along the coast is growing in South Korea, and particularly sea level rise is likely to increase the vulnerability of coastal areas. This study aims to investigate the sea level rise through Mann-Kendall(MK) test, ordinary linear regression(OR) and quantile regression analysis(QRA) with sea level data at the 20 tide stations along the coast of Korean Peninsula. First, statistically significant long-term trends were analysed using a non-parametric MK test and the test indicated statistically significant trends for 18 and 10 stations at the 5% significance level in the annual mean value of sea level and the annual maximum value of sea level, respectively. The QRA method showed better performance in terms of characterizing the degree of trend. QRA showed that an average annual rise in mean sea level is about 1-6 mm/year, and an average rise in maximum sea level is about 1-20 mm. It was found that upward convergent and upward divergent were a representative change given the nine-category distributional changes. We expect that in future work we will address nonstationarities with respect to sea level that were identified above, and develop a nonstationary frequency analysis with climate change scenarios.

• ETRI Journal
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• v.30 no.1
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• pp.47-58
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• 2008

In sensor networks, analyzing power consumption before actual deployment is crucial for maximizing service lifetime. This paper proposes an instruction-level power estimator (IPEN) for sensor networks. IPEN is an accurate and fine grain power estimation tool, using an instruction-level simulator. It is independent of the operating system, so many different kinds of sensor node software can be simulated for estimation. We have developed the power model of a Micaz-compatible mote. The power consumption of the ATmega128L microcontroller is modeled with the base energy cost and the instruction overheads. The CC2420 communication component and other peripherals are modeled according to their operation states. The energy consumption estimation module profiles peripheral accesses and function calls while an application is running. IPEN has shown excellent power estimation accuracy, with less than 5% estimation error compared to real sensor network implementation. With IPEN's high precision instruction-level energy prediction, users can accurately estimate a sensor network's energy consumption and achieve fine-grained optimization of their software.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.8
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• pp.1290-1302
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• 2010

This study examines the effects of competency and service orientation of imported fashion luxury brands salespersons on the organizational commitment and service delivery level. Questionnaire data from 162 salespersons of imported fashion luxury brands were analyzed. The results were summarized as follows. First, self-management ability, professional executive ability, and the friendly attitude of six competency factors had significant effects on organizational commitment. Second, professional executive ability, self-management ability, and friendly attitude of the six competency factors had significant effects on service delivery level. Third, all factors of service orientation had significant influences on organizational commitment. Finally, special treatment/awareness of needs and instant response/communicative skill of three service orientation factors had significant influences on the service delivery level.

• Journal of Ocean Engineering and Technology
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• v.25 no.4
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• pp.36-41
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• 2011

In the present paper, a direct forcing/fictitious domain (DF/FD) level set method is proposed to simulate the FSI (fluid-solid interaction) in two-phase flow. The main idea is to combine the direct-forcing/fictitious domain (DF/FD) method with the level set method in the Cartesian coordinates. The DF/FD method is a non-Lagrange-multiplier version of a distributed Lagrange multiplier/fictitious domain (DLM/FD) method. This method does not sacrifice the accuracy and robustness by employing a discrete ${\delta}$ (Dirac delta) function to transfer quantities between the Eulerian nodes and Lagrangian points explicitly as the immersed boundary method. The advantages of this approach are the simple concept, easy implementation, and utilization of the original governing equation without modification. Simulations of various water-entry problems have been conducted to validate the capability and accuracy of the present method in solving the FSI in two-phase flow. Consequently, the present results are found to be in good agreement with those of previous studies.

• Journal of Sensor Science and Technology
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• v.17 no.4
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• pp.308-316
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• 2008

For the measurement of liquid level in ship's cargo tank, ballast tank, fuel oil tank and fresh water tank, several types of gauge meter are used such as tubular type, magnetic float type, reflex type transparent type and welding pad type. Among them, magnetic float type gauge meter is environmental friendly device because it is free of power source and maintenance. The main obstacle of the device is relatively large error bound. In this paper, finite element method is used to design and analysis of the magnetic float type gauge meter. The operation of reed switch according to the magnetic field has been successfully described and agreed well with experimental measurement. The optimum geometry with combination of permanent magnet and reed switches are designed to achieve 98 % accuracy of fluid level.

• Journal of Korean Library and Information Science Society
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• v.25
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• pp.339-375
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• 1996

This study is to identified the motivation level which university librarians in Korea perceived as motivating them, and to examine relationship between those motivation level and the demographic characteristics of university librarians. The results of this study are summarized as follows : (1) The factors that the motivation level is higher than the average (3.000) are shown to be human relation (3.399), working itself (3.198), and supervision (3.050), but the other factors : recognition (2.995), communication (2.985), salary (2.892), job evaluation (2.622), job environment (2.619), and promotion (2.126) are shown to be lower than the average. (2) In the results of X$^{2}$ test about the differences of the motivation level among 6 demographic attributes of the population, the attributes shown a significant difference are as follows : Salary : rank ; working terms ; sex ; national university or private one ; qualification. Promotion : rank ; sex ; national university or private one ; qualification. Recognition : rank. Human relation : no significant differences among 6 attributes. Work itself : rank ; sex. Communication : rank ; working terms ; sex ; education background ; qualification. Job evaluation : sex ; education background ; qualification. Job environment : sex ; national university or private one. Supervision : rank ; working terms ; sex ; education background ; qualification.

• Journal of Power Electronics
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• v.18 no.2
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• pp.522-532
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• 2018

The cascaded H Bridge (CHB) multilevel inverter (MLI) is popular among the classical MLI topologies due to its modularity and reliability. Although space vector modulation (SVM) is the most suitable modulation scheme for MLIs, it has not been used widely in industry due to the higher complexity involved in its implementation. In this paper, a simple and novel generalized SVM algorithm is proposed, which has both reduced time and space complexity. The proposed SVM involves the generalization of both the duty cycle calculation and switching sequence generation for any n-level inverter. In order to generate the gate pulses for an inverter, a generalized switch matrix (SM) for the CHB inverter is also introduced, which further simplifies the algorithm. The algorithm is tested and verified for three-phase, three-level and five-level CHB inverters in simulations and hardware implementation. A comparison of the proposed method with existing SVM schemes shows the superiority of the proposed scheme.

• Journal of Families and Better Life
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• v.27 no.2
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• pp.77-97
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• 2009

This study evaluates the poverty experiences of low-income single mothers according to the Capability Approach of Amartya Sen. In this approach, the capability to achieve the basic functionings of life, not income itself, is the criterion of poverty. 26 single mothers were interviewed using focus-group interviews and in-depth interviews. 21 functionings on the existence level, 18 on the relatedness level, and 15 on the growth level were found in the areas of work, health, food consumption, clothing, housing, child rearing, and leisure. The results of this study suggest that low-income single mothers can achieve only some of the existence level functionings with significant help from welfare services. They can scarcely achieve higher level functionings in any of these areas.

• Journal of Family Resource Management and Policy Review
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• v.14 no.4
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• pp.263-277
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• 2010

The purpose of this study was to investigate levels of self-esteem and related variables among the elderly. The data is from the Korea Welfare Panel Study conducted in 2007. The data was gathered from 2077 elderly, over 65 years old, and was analyzed by Step multiple regression analysis. The major results were as follows. First, the overall level of self-esteem was in the middle range, with an average of 28.18 points. Second, self-esteem levels showed significant differences in terms of gender, age, education level, health, spouse, health insurance, job, monthly household expenses, national pension, assets, home ownership, satisfaction with spouse, satisfaction with leisure, satisfaction with social network, economic services, medical services, and other services. Finally, Model 1 showed meaningful influences from gender, age, education level, health, spouse, and health insurance. Model 2 showed meaningful influences from education level, health, spouse, health insurance, job, and national pension. Models 3 and 4 showed meaningful influences from education level, health, job, satisfaction of spouse, satisfaction with leisure, and satisfaction with social network. In other words, the factors that had the most significant impact on self-esteem were satisfaction.

• Korean Journal of Health Education and Promotion
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• v.29 no.5
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• pp.61-75
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• 2012

Objectives: A great number of the elderly are not aware of having metabolic syndrome, and this pattern differs among regions of the nation. This issue is particularly important for the elderly people with chronic diseases. This study was conducted in order to identify the prevalence, predicting factors of perception and exercise behaviors of among the elderly population. Methods: Using data from the 2009 Korean Community Health Survey, we employed two-level logistic regression models to determine whether individual and community factors are associated with perception and exercise behaviors among the elderly population. Results: Results from weighted two-level logistic regression analyses indicated the individual-level factors of smoking, education level, health center education, community exercise program participation and unmet needs in men, and marital status (being separated), health center education women predicted the elders' perception. As for the community-level predictors, higher smoking and living in regions with high suicide rates significantly predicted the elders' perception and exercise behaviors of metabolic syndrome. Conclusions: These findings demonstrate that education according to stage would increase the perception and motivation toward healthier behavior particularly for the elderly with lower perception levels of metabolic syndrome.