• Wind and Structures
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• v.20 no.6
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• pp.763-791
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• 2015

"Wind and Ports" is a European project that has been carried out since 2009 to handle wind forecast in port areas through an integrated system made up of an extensive in-situ wind monitoring network, the numerical simulation of wind fields, the statistical analysis of wind climate, and algorithms for medium-term (1-3 days) and short term (0.5-2 hours) wind forecasting. The in-situ wind monitoring network, currently made up of 22 ultrasonic anemometers, provides a unique opportunity for detecting high resolution thunderstorm records and studying their dominant characteristics relevant to wind engineering with special concern for wind actions on structures. In such a framework, the wind velocity of thunderstorms is firstly decomposed into the sum of a slowly-varying mean part plus a residual fluctuation dealt with as a non-stationary random process. The fluctuation, in turn, is expressed as the product of its slowly-varying standard deviation by a reduced turbulence component dealt with as a rapidly-varying stationary Gaussian random process with zero mean and unit standard deviation. The extraction of the mean part of the wind velocity is carried out through a moving average filter, and the effect of the moving average period on the statistical properties of the decomposed signals is evaluated. Among other aspects, special attention is given to the thunderstorm duration, the turbulence intensity, the power spectral density and the integral length scale. Some noteworthy wind velocity ratios that play a crucial role in the thunderstorm loading and response of structures are also analyzed.

• Child Health Nursing Research
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• v.10 no.1
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• pp.89-97
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• 2004

Purpose: Adolescence is viewed as a critical period in the formation of health behavior and many health behaviors developed during this era persist into adulthood. Social-cognitive theory, self-efficacy as a central construct, has been used to predict and intervene the health behavioral patterns in adolescent. Previous research demonstrated that the attachment in childhood and self-esteem as psychosocial factors are predictors of the health efficacy in adolescent and it is viewed as solely an antecedent for the lifelong health behavior. Method: To investigate the path pattern of attachment in childhood, self-esteem and health efficacy in adolescents, 381 adolescents in high school from two urban cities in Korea were recruited for cross-sectional sample. Attachment in childhood was measured using Mother-Father-Peer Scale. Self esteem was measured with Hare self esteem. Perceived self efficacy in Health was measured by the School Health Efficacy Questionnaire. The path analysis revealed a significant relationship between attachment in childhood and self-esteem, self-esteem and health efficacy in adolescents. Self esteem was the strongest contributing factor for health efficacy in adolescent. The results suggest that attachment in childhood may aid in formulating positive self -esteem in adolescents and self-esteem played a major role in predicting health efficacy in adolescents. Conclusion: Therefore, self-esteem enrichment should be incorporated with adolescent health promotion and certainly should be a component in any health education program in school health program and interventions. These results have implications of psychosocial and family related factors on health promotion and health education for the health care provider with regard to primary and secondary prevention in adolescent population.

• Physical Therapy Korea
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• v.15 no.2
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• pp.20-29
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• 2008

The purpose of this study was to examine the validity and reliability of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)-VA3.0 in patients with hip and knee osteoarthritis (OA). The sample consisted of 301 patients who had received treatments at the physical therapy units of 5 medical institutions in Andong City in june 2006. Questionnaires on the WOMAC were recruited by 12 physical therapists. The internal structure and reliability of the scales were evaluated by means of item-internal consistency (Cronbach's alpha coefficient: ${\alpha}$), item-discriminant validity, and Pearson's relation coefficient. To explore construct validity, we conducted a principal component factor analysis with varimax rotation analysis. The criterion for factor extraction was an eigenvalue >1.0. The average age of the patients was 62.1 years. All WOMAC subscales (pain, stiffness, and physical function) were internally consistent with Cronbach's coefficients of .81, .91, and .80, respectively. The internal consistency reliability of item-each scale were also internally consistent with Cronbach's coefficient of .89 (Pearson's correlation coefficient: .71~.84), .93 (.89~.91), and .96 (.67~.91), respectively. However, high correlation was found among 3 items (.66~.83, .66~.67, and .67~.83), so the item-discriminant validity was low (${\alpha}$ coefficient: .81, .91, .80, respectively). The construct validity by factor analysis was low because it was not consistent With WOMAC-VA3.0. In conclusion, the results reported here confirm the reliability of the WOMAC in patients with OA of the hip and knee. The collection of information on the hip and knee osteoarthritis using this instrument was acceptable to patients. A further prospective multi-center study will be necessary to prove the construct validity.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.13 no.4
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• pp.1-7
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• 2017

The energy slab is a ground coupled heat exchanger equipped in building slab structures, which represents a layout similar to the horizontal ground heat exchanger (GHEX). The energy slab is installed as one component of the floor slab layers in order to utilize the underground structure as a hybrid energy structure. However, as the energy slab is horizontally arranged, its thermal performance is inevitably less than the conventional vertical GHEXs. Therefore, stainless steel (STS) pipes are alternatively considered as a heat exchanger instead of high density polyethylene (HDPE) pipes in order to enhance thermal performance of GHEXs. Moreover, not only a floor slab but also a wall slab can be utilized as a heat-exchangeable energy slab in order to maximize the use of underground space effectively. In this paper, four field-scale energy slabs were constructed in a test bed, which consist of the STS and HDPE pipe, and a series of thermal response tests (TRTs) was conducted to evaluate relative heat exchange efficiency per unit pipe length according to the pipe material and the configuration of energy slabs. The energy slab equipped with the STS pipe shows higher thermal performance than the energy slab with the HDPE pipe. In addition, thermal performance of the wall-type energy slab is almost equivalent to the floor-type energy slab.

• Journal of Drive and Control
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• v.16 no.4
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• pp.16-22
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• 2019

The electro-hydraulic training device (TP511) provided by Festo Didactic are widely used, but teaching materials do not include mathematical modeling. Thus, there is a limit for full-scale learning about the electro-hydraulic servo system by using this equipment. In this study, for the purpose of improving students' understanding of the classical control and modern control Festo's electro-hydraulic servo training device (TP511) was mathematically modeled and parameter values were calculated by examining the characteristics of each component. And P, PI, PD, and PID controllers highly used in the industrial field, were designed by using the root locus method to achieve the optimal gains and used for simulation and experiments using the Festo's electro-hydraulic servo training apparatus. The validity of the derived mathematical model and the calculated parameter values were verified through simulation and experiment. It was found that the p control can achieve the control target more effectively than the pid control for Festo's electro-hydraulic servo training system by using the root locus method.

• Journal of Korean Academy of Nursing
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• v.34 no.8
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• pp.1434-1442
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• 2004

Purpose. Professional nursing ethics is a living, dynamic set of standards for nurses' professional moral behavior. Furthermore, in daily clinical nursing training, nursing students are constantly confronted with decision-making that is moral in nature. The aim of this study was to identify the perceived ethical attitudes in the clinical training process of senior nursing students using Q-methodology to offer basic strategies for nursing ethics education and thereby improve patients' care. Methods. Q-methodology provides a scientific method for identifying perception structures that exist within certain individuals or groups. Thirty-seven participants in a university rated 38 selected Q-statements on a scale of 1-9. The collected data were analyzed using pc-QUNAL software. Results. Principal component analysis identified 3 types of ethical attitudes in nursing students in Korea. The categories were labeled Sacred-life, Science-realistic and Humane-life. Sacred-life individuals think that a life belongs to an absolute power (God), not a man, and a human life is a high and noble thing. Science-realistic individuals disagreed that allowing an induced abortion or embryo (human) duplication is unethical behavior that provokes a trend, which takes the value of a life lightly; most of them took a utilitarian position with respect to ethical decisions. Humane-life individuals exhibit a tendency toward human-centered thought with respect to ethical attitudes. Conclusion. This study will be of interest to educators of students of nursing and hospital nursing administrators. Also, the findings may provide the basis for the development of more appropriate strategies to improve nursing ethics education programs.

• Journal of Communications and Networks
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• v.14 no.4
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• pp.451-460
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• 2012

Natural disasters often lead to regional failures that can cause network nodes and links co-located in a large geographical area to fail. Novel approaches are required to assess the network vulnerability under such regional failures. In this paper, we investigate the vulnerability of networks by considering the geometric properties of regional failures and network nodes. To evaluate the criticality of node locations and determine the critical areas in a network, we propose the concept of ${\alpha}$-critical-distance with a given failure impact ratio ${\alpha}$, and we formulate two optimization problems based on the concept. By analyzing the geometric properties of the problems, we show that although finding critical nodes or links in a pure graph is a NP-complete problem, the problem of finding critical areas has polynomial time complexity. We propose two algorithms to deal with these problems and analyze their time complexities. Using real city-level Internet topology data, we conducted experiments to compute the ${\alpha}$-critical-distances for different networks. The computational results demonstrate the differences in vulnerability of different networks. The results also indicate that the critical area of a network can be estimated by limiting failure centers on the locations of network nodes. Additionally, we find that with the same impact ratio ${\alpha}$, the topologies examined have larger ${\alpha}$-critical-distances when the network performance is measured using the giant component size instead of the other two metrics. Similar results are obtained when the network performance is measured using the average two terminal reliability and the network efficiency, although computation of the former entails less time complexity than that of the latter.

• Journal of Environmental Science International
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• v.20 no.6
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• pp.737-753
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• 2011

The typical characteristics of seasonal winds were studied around the Pohang using two-stage (average linkage then k-means) clustering technique based on u- and v-component wind at 850 hpa from 2004 to 2006 (obtained the Pohang station) and a high-resolution (0.5 km grid for the finest domain) WRF-UCM model along with an up-to-date detailed land use data during the most predominant pattern in each season. The clustering analysis identified statistically distinct wind patterns (7, 4, 5, and 3 clusters) representing each spring, summer, fall, and winter. During the spring, the prevailed pattern (80 days) showed weak upper northwesterly flow and late sea-breeze. Especially at night, land-breeze developed along the shoreline was converged around Yeongil Bay. The representative pattern (92 days) in summer was weak upper southerly flow and intensified sea-breeze combined with sea surface wind. In addition, convergence zone between the large scale background flow and well-developed land-breeze was transported around inland (industrial and residential areas). The predominant wind distribution (94 days) in fall was similar to that of spring showing weak upper-level flow and distinct sea-land breeze circulation. On the other hand, the wind pattern (117 days) of high frequency in winter showed upper northwesterly and surface westerly flows, which was no change in daily wind direction.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.5
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• pp.1-8
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• 2005

SPEC CPU2000 is an widely used benchmark program, both in industry and in academy, for measuring compute-intensive performance of computer systems with various architectures. However, there has been little effort to investigate its characteristics with respect to hardware components. This paper presents the performance scalability of SPEC CPU2000 benchmark over CPU clock speed. For an Intel x86-based system running at various clock speed, we measure the performance of SPEC CPU2000 benchmark, and analyze the characteristic of SPEC CPU2000 in a system aspect. In the experiment, we found that the overall performance of SPEC CPU2000 increases monotonically and linearly as the CPU clock speed increases and that the scale efficiencies of SPEC CPU2000 component benchmarks are quite evenly distributed.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.22 no.1
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• pp.17-25
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• 2016

Purpose: This study was aimed to determine the effects of thoracic spine thrust manipulation on muscle activities of the scapular upward rotators and middle deltoid, active range of motion (AROM), shoulder pain, and rounded shoulder posture in young adults with rounded shoulder. Methods: The subjects were 30 young adults (14 males, 16 females) with rounded shoulder. Thirty subjects were randomly assigned to an experimental (manipulation) and control (placebo) groups of fifteen subjects respectively. The manipulation group received the manipulation (high velocity, low amplitude), which was performed by a physical therapist with the subject in the supine position and with the arms crossed over the chest and hands passed over the shoulders. For the sham group, the same procedure was performed, with the exception that the high-velocity thrust was not applied. Measurements were taken before and after the intervention. Muscle activity of upper and lower trapezius, serratus anterior, middle deltoid was measured using surface electromyography. Visual analog scale (VAS) was used for shoulder pain. Goniometry was used for shoulder abduction active range of motion (AROM). Straight edge was used for supine rounded shoulder posture (RSP) distance. Results: The muscle activity of the upper trapezius, lower trapezius and middle deltoid muscle increased significantly after the intervention (p<.05). However, no significant difference was observed in serratus anterior muscle (p>.05). The VAS was significantly decreased and AROM significantly increased after the intervention (p<.05). The distance of RSP were not significant (p>.05). The control group showed no differences before and after the intervention (p>.05). Conclusion: The results of this study suggest that thoracic spine thrust manipulation can be an effective component of treatment plan to improve pain and function.