• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.04a
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• pp.346-350
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• 2010

도시화재의 연소 확대성상을 모델화하기 위해 화재실의 개구를 통하여 분출하는 열기류의 온도 평가 실험을 실시하였다. 실험은 축소모형 형태로 개구 조건과 화원조건에 의해 진행이 되었다. 실험 결과 온도분포 Trajectory는 개구종횡비 n에 의해 횡정(橫井)의 연구결과와 비교하여 n=2일때를 제외하고는 다른 경향을 나타냈다. 동일 조건에서 분출화재보유열량 $Q_{ef}$은 개구 조건이 횡장창($B0.2m{\times}H0.1m$)이고, 단일개구일 때 가장 높은 값을 나타냈다. 또한, 분출화재의 발생 한계 발열속도 $Q_{verit}$에서도 굴웅아(堀雄児)의 연구와 유사한 결과를 보이며, 다른 개구조건보다 횡장창($B0.2m{\times}H0.1m$)일 때 높은 값을 나타냈다.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.905-911
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• 2009

The viscosity drive method by the wheel which is widely used in the conventional railway systems needs a large friction force between the wheel and the guide-rail, which brings on a thrust force for a quick acceleration and a high-speed travelling. In addition, the viscosity drive method needs an increase of the vehicle weight for a large friction force. However, a maglev train is possible to be driven by the electro-magnet instead of the wheel, which produces a levitation and thrust force without any contact. In general, low-speed maglev train uses a linear induction motor(LIM) for propulsion that is operated under 300[km/h] due to the power-collecting and end-effect problems of LIM. In case of high-speed maglev train, a linear synchronous motor(LSM) is more suitable than LIM because of a high-efficiency and high-output properties. LSM has a driving principle as same as a conventional rotary synchronous motor(RSM), and the torque of RSM becomes the thrust force of LSM. A conventional LSM has relatively large air-gap compared with a conventional RSM. So, it must be achieved a design that is considered normal force by finite-asymmetric structure, end-effect on the entry and exit part, and support structure of a moving part. Therefore, in this research, authors accomplish a conceptualizing and basic design of a small-scaled LSM, and characteristics analysis using FEM.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.13 no.4
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• pp.387-394
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• 2000

The nonlinear modal interaction of an autoparametric system under a broadband random excitation is investigated. The specific system examined is an autoparametric vibration absorber with internal resonance, which is typical of many common structural configurations. By means of Gaussian closure scheme the dynamic moment equations explaining the random responses of the system are reduced to a system of autonomous ordinary differential equations of the first and second moments. In view of equilibrium solutions of this system and their stability we examine the system responses. We could not find the destabilizing effect of damping, which was reported in References (18) and (20). The saturation phenomenon, which is well known in deterministic nonlinear system, did not take place lot this system subject to broadband random excitation.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.2
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• pp.159-167
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• 2017

The purpose of this study is to accurately estimate the wind-induced responses of a tall building structure for using the estimated responses in the process of calculating the optimal force of an active control device. Kalman filter was used for the estimation process and a 3-storied model structure on a shaking table was tested for the verification of the estimation accuracy. The system matrices of the model were constructed based on the mode parameters obtained by the system identification. The estimated displacement matched up well with the measured one. Finally, the wind-induced responses of a real 39-storied building structure excited by the typhoon MUIFA were estimated.

• Journal of Korea Society of Digital Industry and Information Management
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• v.15 no.4
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• pp.41-49
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• 2019

Patents are system to promote the development of industry by disclosing technology. The importance of recent patent is being emphasized. For this reason, companies apply for many patents. And they analyze the patent. Patent analysis helps to protect and foster their technology. Previously this method has been carried out by experts. Expert-based patent analysis, however, has the disadvantage of being time-consuming and expensive. Consequently, we try to solve this problems by developing prediction model. Therefore, this paper proposes a data-based patent analysis method using quantitative indicator and textual information. We confirmed the practical applicability of the proposed method through 1,831 autonomous vehicle patents. As a result, it was possible to confirmed that safety and lane detection related technologies are important.

• Journal of Korea Society of Industrial Information Systems
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• v.21 no.4
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• pp.1-11
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• 2016

Recently numerous studies are conducted to estimate the human personality from the online social activities. This paper develops a comprehensive model for political attitude estimation leveraging the Facebook Like information of the users. We designed a Facebook Crawler that efficiently collects data overcoming the difficulties in crawling Ajax enabled Facebook pages. We show that the category level selection can reduce the data analysis complexity utilizing the sparsity of the huge like-attitude matrix. In the Korean Facebook users' context, only 28 criteria (3% of the total) can estimate the political polarity of the user with high accuracy (AUC of 0.82).

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.289-292
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• 2008

In this study, we interpreted 20 story building by applying the modified modulus of elasticity considering the reinforcing steel proposed in previous literature, and analyzed the movement of the structure according to axial reinforcing steel ratio and lateral reinforcing steel volume ratio. Additionally, we tried to get the result similar to the actual movement considering the order of the construction by performing the analysis by construction stage. Finally, we tried to reduce the section of the column through the analysis considering the reinforcing steel of the column. When interpreting the 20 story building considering the reinforcing steel in the columns, we can reduce the column members up to 4.94% comparing to the general analysis. If we do the same for each construction stage, it is analyzed that we can reduce up to 19%.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.7
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• pp.1248-1254
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• 2010

Authors conducted a deduction of some parameters using the magnetic equivalent circuit method and a verification study of the thrust force control algorithm of a rotary-typed small-scaled linear induction motor for a railway transit. In a LIM, it is possible to express the parameters of the magnetic equivalent circuit into a function of the shape of the secondary aluminium plate and the airgap between the LIM primary core and the secondary aluminium plate. It means that the LIM properties can be changed considerably by the shape of the secondary aluminium plate and the airgap between the LIM primary core and the secondary aluminium plate. So, authors analyzed a tendency of changes of the magnetic equivalent circuit parameters and the LIM characteristics by changing of the airgap of the secondary aluminium plate of a rotary-typed small-scaled LIM. And authors conducted a verification study of the indirect vector control algorithm with constant slip frequency by using the rotary-typed small-scaled LIM tester set on the basis of the calculated LIM parameters. Finally authors accomplished a research on applicability for LIM railway transit.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.4
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• pp.413-419
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• 2011

The nano-size hoenycomb structures have the higher ratio of the surface to the volume than macro-size honeycomb structures, and they can maximize the functionality of the electrical and chemical catalyst. The mechanical behaviors of the nano-sized structures are different from ones of the macro-size structure, and it is caused by the surface effect. This surface effect can be investigated by the atomistic simulation; however, the prediction of mechanical behaviors of the nano-sized honeycombs are practically impossible due to excessive computational resources and computation time. In this paper, by combining the bridging method considering the surface stress elasticity model with homogenization method, the mechanical behaviors of the nano-sized honeycombs are predicted efficiently.

• The Journal of the Convergence on Culture Technology
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• v.4 no.1
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• pp.279-284
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• 2018

With the availability of real-time student behavioral data, personalization on education is gaining a huge traction. Data collected from massively open online courses (MOOC) has shifted the content delivery method from fixed, static to user-adopted form. Such educational content can be personalized by student's level of achivement. In this paper, we propose a service that automates the content restructuring, based on dynamic profile. With the student behavioral data, the proposed service restructures educational content by changing the order, extending and shrinking the published material. To do this, we record students' behavioral data and content information as a metadata, which will be used to generate dynamic profile.