• Earthquakes and Structures
• /
• v.3 no.3_4
• /
• pp.413-434
• /
• 2012

This paper presents a displacement-based seismic design method with damage control, in which the targets for the considered performance level are set as displacements and a damage distribution is proposed by the designer. The method is based on concepts of basic structural dynamics and of a reference single degree of freedom system associated to the fundamental mode with a bilinear behaviour. Based on the characteristics of this behaviour curve and on the requirements of modal spectral analysis, the stiffness and strength of the structural elements of the structure satisfying the target design displacement are calculated. The formulation of this method is presented together with the formulations of two other existing methods currently considered of practical interest. To illustrate the application of the proposed method, 5 reinforced concrete plane frames: 8, 17 and 25 storey regular, and 8 and 12 storey irregular in elevation. All frames are designed for a seismic demand defined by single earthquake record in order to compare the performances and damage distributions used as design targets with the corresponding results of the nonlinear step by step analyses of the designed structures subjected to the same seismic demand. The performances and damage distributions calculated with these analyses show a good agreement with those postulated as targets.

• Journal of the Korean Geotechnical Society
• /
• v.19 no.6
• /
• pp.61-70
• /
• 2003

The behaviour of an earth and rock-fill dam is complicated due to reservoir water and various materials in zoned dams. Different materials with a wide range of permeability and seasonal variation of reservoir water result in the time dependent post-constructional behaviour. In aged dams it is often required to control water level to keep the dams safe. In this case information on the post-constructional dam behaviour is important. However, present geotechnical knowledge does not fully support the occasion. In this study the post-constructional behaviour of a dam is investigated using coupled finite element models for series of idealized water reservoir cases: impoundment, draw down, seasonal fluctuation with different rising and falling speeds. Numerical results were analysed in respect of geotechnical parameters such as load transfer, hydraulic fracturing potential and stress paths. It is shown that the control of water level is an important factor while operating dams.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.2
• /
• pp.184-188
• /
• 2001

In a summer study during May to July, involving 12 young Murrah buffalo bulls at forty months of average age, the effects of multiple shower vs single shower body cooling and vitamin A, D and E supplementation on the sexual behaviour, semen quality and freezability were investigated. The animals were divided into two groups (6 animals in each group) and housed in a half-walled shed with proper spacing, the feeding management being identical. The bulls in the control group were given a single shower at 1000 h, whereas the experimental bulls were given four showers at 10,12,14 and 16 h. In addition, the experimental bulls were given vitamin A, D and E injections at fifteen day intervals. The sexual behaviour of bulls was observed in terms of reaction time, sexual aggressiveness and ejaculatory thrust. Semen quality of all the bulls was assessed in terms of volume, mass activity, live-dead sperm and sperm concentration, sperm motility and morphology, and acrosomal abnormality. The sexual behaviour did not vary significantly between the groups, whereas semen quality differed significantly for volume, per cent live sperms, total sperms per ejaculate and total live sperm per ejaculate between groups. It can be concluded that sexual behaviour was not influenced by the thermal comfort treatment coupled with periodic vitamin A, D and E injections. But the treatments improved most of the seminal traits in the experimental group of bulls. However, benefit of treatment was not reflected in the freezability traits of the semen.

• Journal of Power System Engineering
• /
• v.4 no.1
• /
• pp.51-59
• /
• 2000

Active suspension systems have been using for improving ride quality and stability for vehicles. An active suspension system is composed of a hydraulic pump, pressure control valves, hydraulic dampers, vehicle body, tires and other components. In this study, the mathematical model for the active suspension system based on the quarter car concept is derived, and a program for analysing the dynamic behaviour of the suspension system is developed. The computed results by the developed program are compared with the experimental results for confirming the reliability and usefulness of the developed program.

• 제어로봇시스템학회:학술대회논문집
• /
• 1994.10a
• /
• pp.488-493
• /
• 1994

The global stability of model reference adaptive control system (MRACS) in the ideal case was resolved in the 1980's. Hoever the improvement of the transient, behaviour of MRACS has not been discussed sufficiently even in the ideal case. Only a few attempts have so far been made at the application of MRACS to the practical systems in contrast to the theoretical systematization. Therefore, when we consider the practical usage of MRACS it is necessary to develop an improved design scheme with respect to transient behaviour. In this paper, we propose two design schemes improving transient behaviour of MRACS by mollifying the input synthesis in the conventional design scheme of MRACS. We present a design scheme of MRACS in which we utilize the design approach of variable structure system(VSS). After describing the above design scheme, we also propose the improved design scheme in which we introduce the dead-zone decided by the magnitude of the output-error between the plant and the reference model. The effectiveness of the proposed two design schemes are shown through computer simulations. As the results, by using these methods, the convergence of the transient response is greatly improved in comparison with the conventional one.

• Korean Journal of Child Studies
• /
• v.17 no.1
• /
• pp.227-243
• /
• 1996

The purpose of this study was to investigate the prevalence of EBD (Emotional and Behaviour Difficulties) and to examine relationships of EBD to family and classroom psychosocial functioning. Two studies were carried out. The subjects were 840 children aged 7 to 12 for the first study and 448 children aged 12 for the second study. CBQ for children's behaviour, FACES III for family functioning and a short version of CES for classroom functioning were used. The prevalence of EBD was 9.4% by parents, 10.6% by teachers and 2.1% by both on the basis of Korean cut-off points. It was 13.7%, 20.8% and 4.3%, respectively, based on England points. More children were identified as EBD in boys, in one-child families and in lower academic group. EBD tended to be higher with lower levels of psychosocial functioning but classroom-control. The relationships were more consistent and high with children's rather than adults' perception, and with teachers' rather than mothers' ratings. The findings were discussed in terms of the scale validity, the concept of 'open systems' and differences in the validity of ratings.

• The Journal of Pediatrics of Korean Medicine
• /
• v.23 no.1
• /
• pp.127-140
• /
• 2009

Objectives In this study, we obtained Korean version of CEBQ (Children's Eating Behaviour Questionnaire) and verify whether it is reliable or not. Methods Total 106 parents completed this questionnaire, and we gathered children's BMI data and examined the relationship between children's BMI and mean scale scores. Results 1. This study results confirmed the theorectical factor structure, with acceptable internal reliability and between-subscale correlations. 2. There are significant mean scale scores difference between anorexia group and control group. 3. There are significant relations between children's BMI and mean scale scores. Conclusions The results support the use of the CEBQ as a phsychometrically sound tool for assessing children's eating behaviours in Korean children.

• Journal of Powder Materials
• /
• v.11 no.4
• /
• pp.301-307
• /
• 2004

Successful implementation of the powder forming process requires a detailed understanding of several interacting phenomena. The aim is to better control the process variables and to optimize the design parameters. A number of studies were carried out using various constitutive models that take the density change during powder forming into account. Most of them were developed for powders and sintered porous metals, but few of them can describe powder agglomerates, whose behaviour is different from that of uniformly arranged powders. The modification is needed to account for the effect of agglomeration on densification behaviour. Incorporating powder agglomeration into a constitutive model is of considerable importance, as it provides a possibility of relating the powder densification response to microstructural characteristics of powder particles, especially in case of nano powders. In this paper, we proposed a new powder agglomerate model in order to describe the unique densification behaviour of nano powders. The proposed model was applied to the densification of powder agglomerates during cold isostatic pressing.

• Journal of Animal Environmental Science
• /
• v.2 no.2
• /
• pp.117-122
• /
• 1996

The purpose of this study was to investigate the effect of colors of feed-trough on the eating behaviour of pullets. A total of 64 12wks old pullets were assigned to a $4{\times}4$ Latin square design with 4 treatments(control, blue, yellow, red colored feed-troughs). The results of the study are summarized as follows: 1. Average daily gain and eed intake of the pullets were significantly(P<0.05) decreased with red color feed-troughs. 2. Feed conversion ratio appeared to be improved in the yellow color group compared to the others. 3. Total time spent for eating were not significantly different, among treatments.

• Molecules and Cells
• /
• v.28 no.2
• /
• pp.75-80
• /
• 2009

The cyclic environmental conditions brought about by the 24 h rotation of the earth have allowed the evolution of endogenous circadian clocks that control the temporal alignment of behaviour and physiology, including the uptake and processing of nutrients. Both metabolic and circadian regulatory systems are built upon a complex feedback network connecting centres of the central nervous system and different peripheral tissues. Emerging evidence suggests that circadian clock function is closely linked to metabolic homeostasis and that rhythm disruption can contribute to the development of metabolic disease. At the same time, metabolic processes feed back into the circadian clock, affecting clock gene expression and timing of behaviour. In this review, we summarize the experimental evidence for this bimodal interaction, with a focus on the molecular mechanisms mediating this exchange, and outline the implications for clock-based and metabolic diseases.