• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.149-156
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• 2002

Field measurements were carried out in this study to investigate the behavior of cut and cover tunnel such as the distribution and the magnitude of the earth pressure during back fill process of the ground material. Three kinds of measuring instruments, such as the earth pressure load cell, the concrete strain gauge and the reinforcing bar meter of embedded type in concrete structure were installed and measured. Earth pressure load cells, installed after construction of the tunnel lining, measure the outside forces acting on the tunnel lining with radial directions. Three load cells were installed at the crown, the right and the left shoulder of the tunnel, respectively. Three sets of reinforcing bar meter were installed in the double reinforcements of the tunnel lining and their locations were the same with the position of the earth pressure load cells. Concrete strain gauge was installed only one site of the upper compressive part at the tunnel crown. Based on the measuring results in the field, the deformation and the earth pressure acting on the tunnel lining were investigated with the back fill process of the ground material. Considerations on the validity of the measuring results were paid. For the analysis of measurements, after dividing back fill process into three steps, various factors which affect on the behavior of tunnel lining were investigated at each step.

• Journal of the Korean Magnetics Society
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• v.5 no.6
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• pp.963-967
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• 1995

Ultra thin layers of NiFeCo or NiFe were inserted at the interfaces of Ni and Cu to form a multilayer structure. In case of inserting a NiFe layer, the magnetoresistance was about 6%, the saturation magnetic field was 50 Oe and the hysteresis of R-H (resistance-magnetic field) was very small. In case of inserting a NiFeCo layer, the magnetoresistance increased to about 7% but the saturation magnetic field and hysteresis were also increased. The increase of the output under biased magnetic field was much larger in case of inserting a NiFe layer because of relatively smaller hysteresis in R-H behavior.

• Advances in nano research
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• v.10 no.5
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• pp.481-491
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• 2021

Graphene Nanosheets play an important role in nanosensors due to their proper surface to volume ratio. Therefore, the main purpose of this paper is to consider the nonlinear vibration behavior of graphene nanosheets (GSs) under the influence of electromagnetic fields and electrical current create forces. Considering more realistic assumptions, new equations have been proposed to study the nonlinear vibration behavior of the GSs carrying electrical current and placed in magnetic field. For this purpose, considering the influences of the magnetic tractions created by electrical and eddy currents, new relationships for electromagnetic interaction forces with these nanosheets have been proposed. Nonlinear coupled equations are discretized by Galerkin method, and then solved via Runge-Kutta method. The effect of different parameters such as size effect, electrical current magnitude and magnetic field intensity on the vibration characteristics of GSs is investigated. The results show that the magnetic field increases the linear natural frequency, and decreases the nonlinear natural frequency of the GSs. Excessive increase of the magnetic field causes instability in the GSs.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.5
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• pp.748-754
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• 2018

Objective: The preference evaluation of cattle is an important factor for estimation and improvement of the grazing amounts of newly introduced or bred grasses or cultivars in barn. This study was performed to assess the grazing behavior (the amount of grazing and/or the grazing speed) of cattle as indirect method using newly bred Brachiaria ruziziensis tetraploid strain 'OKI-1'(BR) hay as treatment group and Cloris gayana 'Callide' (CG) hay as control group. It also compared the feasibility of using behavioral differences between two groups as one criteria for evaluating preference by Japanese black cattle in barn. Methods: Three experiments were carried out using 12 growing Japanese Black cattle including 6 males and 6 females. In each experiment, the four Japanese Black cattle (2 males and 2 females) were placed in separated stall and allowed to graze BR and CG in manger that was separated into two portions for about 30 min. The position and behavior of the cattle were recorded, and weighed the residual of each gay at 15 and 30 minutes after experiment start. Results: The BR was superior to CG in chemical composition such as protein, fibers and non-fibrous carbohydrate. The cattle, over all, tended to prefer BR over CG in the first half 15 minutes in terms of the time spent and amount of grazing. Additionally, growing cattle exhibited neophilia for BR bred newly. Conclusion: These findings indicated the current approach could be applied for one of criteria to evaluate the preference of hay by Japanese black cattle under indoor housing environment.

• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.1
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• pp.116-127
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• 1996

This paper dealt with FEM analysis of foundation improved with pack drain. The theory on pack drain was scrutinized and observed values in the field were compared with numerical results. Work site of Kwangyang container pier was selected as a ease study in which measurement of settlement and pore water pressure was accurately carried out. Biot's consolidation equation was selected as governing One, coupled with modified Camclay model as constitutive one. Christian and Boehmer's numerical technique was adopted. Behavior of foundation with pack drain is not simple but very complicated. Discontinuity resulted from rigidity difference between adjacent materials, smear effect and complicated boundary conditions should be considered in the behavior analysis of foundation behavior. The results of numerical analysis were influenced by smear zone. In relevant to this effect, finite element analysis was carried out using the reduced horizontal coefficient of permeability in the smear zone; The numerical results were compared with observed values in surface settlement. including pore water pressure. However only lateral di5plaoement by numerical ana1Ysis was shown since its measurement was not performed in the field. The predication of settlement to be developed later can be effectively employed for the obtimization of construction. The predication of residual settlement using the data measured in the field was made by Hoshino, Asaoka and hyperbolic method. Among them, the hyperbolic method proved best one. Settlements accorded well between numsrical and observed values while pore pressure showed a slight difference. Lateral displacement showed largest values at constant distance from ground surface. The validation of foundation analysis improved with pack drain by computer program employed in this study selecting modified Cam-clay model was satisfactorily secured.

• Journal of the Korean Magnetics Society
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• v.23 no.5
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• pp.154-158
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• 2013

We have analyzed the magnetization curves measures by using VSM and MOKE in synthetic antiferromagnetic coupled CoB/Ru/CoB thin film. The measured results were compared with calculated ones by Stoner-Wohlfarth model based on the magnetization behavior of two ferromagnetic layers ($M_1$, $M_2$). The calculated total magnetization ($M_{tot}=M_1+M_2$) and single layer magnetization($M_1$) behaviors were compared with measured results by using VSM and MOKE, respectively. The total magnetization curve ($M_{tot}=M_1+M_2$) showed reversible magnetization behavior with flopping field of about 50 Oe. While single layer magnetization ($M_1$) behaviors showed irreversible magnetization behavior in the field range of $H_F$ < H < $H_F$. These magnetization behaviors were explained by the angle difference between magnetization directions of two ferromagnetic layers in SAF sample.

• Proceedings of the Safety Management and Science Conference
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• 2009.11a
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• pp.1-7
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• 2009

Most industrial accidents occur when the workers' unsafe behavior and the unsafe situation of workplace take place at the same time. Although human's unsafe behavior is indispensable to work field, the evaluation scheme to detect the causes for the accident resulted from human's unsafe behavior and counterplan should be prepared to prevent and reduce accident. To do this, we first classify the specific background factors in terms of human inner factor and environment factor and then develop the AHP (Analytic Hierarchy Process) model to analyze the background factors that affect the worker's unsafe behavior. We also develop a checklist to be able to evaluate the occurrence possibility of individual worker's unsafe behavior.

• Journal of Information Science Theory and Practice
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• v.4 no.2
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• pp.6-20
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• 2016

In the last few years, a new type of synchronous social networking services (SNSs) has emerged—social live streaming services (SLSSs). Studying SLSSs is a new and exciting research field in information science. What information behaviors do users of live streaming platforms exhibit? In our empirical study we analyzed information production behavior (i.e., broadcasting) as well as information reception behavior (watching streams and commenting on them). We conducted two quantitative investigations, namely an online survey with YouNow users (N = 123) and observations of live streams on YouNow (N = 434). YouNow is a service with video streams mostly made by adolescents for adolescents. YouNow users like to watch streams, to chat while watching, and to reward performers by using emoticons. While broadcasting, there is no anonymity (as in nearly all other WWW services). Synchronous SNSs remind us of the film The Truman Show, as anyone has the chance to consciously broadcast his or her own life real-time.

• Proceedings of the Korean Nuclear Society Conference
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• 2002.05a
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• pp.201.2-201
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• 2002

• Proceedings of the Korean Geotechical Society Conference
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• 1997.09a
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• pp.3-20
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• 1997