• Wind and Structures
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• v.12 no.3
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• pp.205-217
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• 2009

Aerodynamic flutter control for long-span cable-supported bridges was investigated based on three basic girder sections, i.e. streamlined box girder section, box girder section with cantilevered slabs and two-isolated-girder section. Totally four kinds of aerodynamic flutter control measures (adding fairings, central-slotting, adding central stabilizers and adjusting the position of inspection rail) were included in this research. Their flutter control effects on different basic girder sections were evaluated by sectional model or aeroelastic model wind tunnel tests. It is found that all basic girder sections can get aerodynamically more stabled with appropriate aerodynamic flutter control measures, while the control effects are influenced by the details of control measures and girder section configurations. The control effects of the combinations of these four kinds of aerodynamic flutter control measures, such as central-slotting plus central-stabilizer, were also investigated through sectional model wind tunnel tests, summarized and compared to the flutter control effect of single measure respectively.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.7 no.3
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• pp.466-478
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• 2000

The purpose of this study was to identify the effects of music therapy on anxiety of cesarean section wemen. The research design was a nonequivalent control group non-synchronized design. The subjects of this study were 65 cesarean section wemen scheduled for surgery. The study was conducted from October 15, 1999 to January 5, 2000. Two groups consisted of subjects assigned : one the experimental group(33 wemen), and the other the control group(32 wemen). The music therapy was performed 3 times to experimental group just before surgery day, on surgery day. The level of anxiety was measured by State Anxiety Inventory, blood pressure, pulse rate, respiratory rate. The data were analyzed using descriptive statistics, $x^2-test$, t-test, Repeated measures of ANCOVA. The results of study were as fellows : 1) State anxiety scores were significantly different between the experimental group and the control group after music therapy. 2) Systolic blood pressures and diastolic blood pressures were significantly different between the experimental group and the control group after music therapy. 3) Pulse rates were significantly different between the experimental group and the control group after music therapy. 4) Respiratory rates were significantly different between the experimental group and the control group after music therapy. According to these results, music therapy can be regarded as an effective nursing intervention that relieves anxiety of cesarean section wemen.

• International Journal of High-Rise Buildings
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• v.8 no.3
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• pp.201-209
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• 2019

This paper presents a structural design of the "(Tentative Name) Toranomon Hills Residential Tower" which is currently under construction in Tokyo. The building is a reinforced concrete high-rise residential complex building with 54 stories above ground, 4 basement levels, and a building height of about 220 m. It is a requirement to provide the highest grade of residence in Japan, and in terms of the structural design, it is required to provide wide and comfortable spaces with high seismic performance. These requirements are satisfied by providing a total of 774 vibration control walls of two types. Also, to further improve the structural performance, steel fibers at the rate of 1.0vol% are provided in the ultra-high strength concrete used in the column members.

• Safety and Health at Work
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• v.3 no.1
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• pp.52-57
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• 2012

Objectives: Lifting heavy weights involves the Valsalva manoeuvre, which leads to intraocular pressure spikes. We used data from a case-control study to further investigate the hypothesis that occupational lifting is a risk factor for retinal detachment. Methods: The study population included 48 cases (patients operated for retinal detachment) and 84 controls (outpatients attending an eye clinic). The odds ratios (OR) of idiopathic retinal detachment were estimated with a logistic regression model (adjusted for age, sex and body mass index). Three indexes were used to examine exposure to lifting; 1) maximum load lifted, 2) average weekly lifting, 3) lifelong cumulative lifting. Results: For all indexes, the most exposed subjects showed an increased risk of retinal detachment compared with the unexposed (index 1: OR 3.57, 95% confidence interval [CI] 1.21-10.48; index 2: OR 3.24, 95% CI 1.32-7.97; index 3: OR 2.23, 95% CI 1.27-8.74) and dose-response relationships were apparent. Conclusion: These results reinforce the hypothesis that heavy occupational lifting may be a relevant risk factor for retinal detachment.

• Smart Structures and Systems
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• v.8 no.3
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• pp.275-302
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• 2011

This is a review paper on mathematical modeling of actively controlled piezo smart structures. Paper has four sections to discuss the techniques to: (i) write the equations of motion (ii) implement sensor-actuator design (iii) model real life environmental effects and, (iv) control structural vibrations. In section (i), methods of writing equations of motion using equilibrium relations, Hamilton's principle, finite element technique and modal testing are discussed. In section (ii), self-sensing actuators, extension-bending actuators, shear actuators and modal sensors/actuators are discussed. In section (iii), modeling of thermal, hygro and other non-linear effects is discussed. Finally in section (iv), various vibration control techniques and useful software are mentioned. This review has two objectives: (i) practicing engineers can pick the most suitable philosophy for their end application and, (ii) researchers can come to know how the field has evolved, how it can be extended to real life structures and what the potential gaps in the literature are.

• Aerospace Engineering and Technology
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• v.1 no.1
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• pp.117-127
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• 2002

In this paper, structure design of the payload section of the KSR-III was performed. The payload section of the KSR-III, which corresponds to the second stage, consists of the Scientific Payload Section for the mission of the rocket, the Payload Section (Electronics) for the communication between the rocket and the ground station, and the Payload Section (Attitude Control) for the attitude control of the rocket. In order to accomplish the mission, every payload and component should operate successfully during the mission period and the structure must satisfy the requirements of the payloads. In this research, precise composition of the payload section and payloads arrangement of the KSR-III were performed. And the modification of the structure to meet the requirements were described.

• Journal of the Korean Society of Hazard Mitigation
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• v.3 no.3 s.10
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• pp.125-132
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• 2003

In this study, safety analysis of river in flash flood due to local extraordinary rainfall was conducted for the Hong-Je river, which was selected as a representative sample basin because it is one of the most urbanized rivers in Seoul. The rainfall data of precipitation 310.1 mm and probable maximum precipitation (PMP) 740.0 mm in July $14{\sim}15$, 2001 was used to perform safety analysis. Resulting of safety analysis of the flood control in Hong-Je river, case of the 50 year of design frequency, safety section, management section, and danger section were represented to be 85%, 15%, and 0% respectively. For the 200 year of design frequency, safety section decreased by 6% and management section and danger section increment by 4% and 2%, respectively, The variation of management section was not observed with respect to 200 year of frequency. Little variation of safety value for management section for 300 and 500 of frequency increased by 8% and 12% relative to 50 year of frequency, respectively. management section and danger section for 1000 year of frequency increased by 19% and 13% relative to 50 year of frequency.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.9
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• pp.845-853
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• 2012

We propose time-optimal cornering motion trajectory planning and control algorithms for differential wheeled mobile robot with motor actuating voltage constraint, under piecewise constant control input condition. For time-optimal cornering trajectory generation, 1) we considered mobile robot's dynamics including actuator motors, 2) divided the cornering trajectory into one liner section, followed by two cornering section with angular acceleration and deceleration, and finally one liner section, and 3) formulated an efficient trajectory generation algorithm satisfying the bang-bang control principle. Also we proposed an efficient trajectory control algorithm and implemented with an X-bot to prove the performance.

• Current Research on Agriculture and Life Sciences
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• v.6
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• pp.1-6
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• 1988

The experiment was conducted to study on the physiology of developing embryo and endosperm degradation during germination of Zea mays seeds treated with GA 20 and B-Nine 5000 ppm. Data obtained can be summerized as follows : 1. Swelling of seminal root increased the section of GA treatment more or less, on the other hand, the section of B-9 treatment inhibited slightly. 2. According to elapsing of seeding date, epithelial cell of Scutellum expansed in size, and the space of cell increased, that degree was enlarged as follows ; the section of GA, the section of Control, and the section of B-9. 3. According to the elapsing of seeding date, the formation of vascular organization embryo became clearer little by little, the lignification of vascular B-9 treatment section rather higher than the other section. 4. The degradation of Starch Grain is composed of near part of epithelial cell of Scutellum, the shape of degradation radiate from element of a disk shape, and the speed of degradation is the section of GA, the section of Control, the section of B-9 in turn.

• Korean Journal of Occupational Health Nursing
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• v.7 no.2
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• pp.130-135
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• 1998

To investigate the working characteristics of the workers by place of duty, a study was carried out among 591 male workers aged 20-55 employed in an automobile industry in Korea. Workers participated to this study were divided into low back pain(LBP) and control group, according to the self-reports by written questionnaires. Work factors and complaint rates of low back pain were compared to the work places. The results were as follows ; 1) The complaint rates of low back pain were 49.2%(292 men) as a whole, 58.6%(34 men) in Production Control Department I, 50.2%(120 men) in Stamping Tool Department, 46.9%(138 men) in Bus Department. 2) Lifting and earring work of individual workers were directly associated with low back pain. Frequency of lifting and carring work is higher in the Final Body Section(Production Dept. I) and Body I Section(Bus Dept.). 3) LBP group were more frequently involved in working in awkward position(Quality Control Section of Stamping Tool Dept.), bending(Body I Section of Bus Dept.) and twisting posture(Sash Section and Body I Section of Bus Dept.). 4 )Workers exposed to vibration during working shows the higher complaint rate of low back pain.