• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.19 no.2
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• pp.109-116
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• 2023

This study presents a CRUD modelling to simulate the thermal resistance behavior of CRUD, deposited on the surface of a cladding tube of a fuel assembly. When heat produced from fuels transfers to a coolant through a cladding tube, the CRUD acting as an additional thermal resistance is expressed as two layers, i.e., a solid oxide layer and an imaginary fluid layer, which are added to the experimental tube's heat structure of the MARS-KS input data. The validation calculation for the experiments performed in UNIST-DISNY facility showed that the center and surface temperatures of the cladding tube increased as the porosity and the steam amount inside pores of the CRUD got higher. In addition, the temperature gradient in the imaginary fluid layer was calculated to be larger than that in the solid oxide part, indicating that the steam amount inside the layer acted more largely as thermal resistance. It was also evaluated through sensitivity calculations that the cladding tube temperature was more sensitive to the CRUD porosity and the steam amount in pores than to the inlet flow rate of the coolant.

• Electronics and Telecommunications Trends
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• v.32 no.4
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• pp.11-20
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• 2017

본고에서는 인지증강을 위한 서비스, 경험정보 인식 기술과 경험정보 모델링 기술에 관한 동향을 살펴본다. 경험정보 기반 인지증강 서비스를 위해 기존의 센서 데이터 중심의 인식 기술과 더불어 개인 경험상황의 특징을 고려한 인식기술에 관한 연구와 다수의 이질적인 경험 데이터를 기반으로 한 사용자 특정 패턴분석을 위한 경험정보 모델링 및 분석 기법에 관한 지속적이고 폭넓은 연구가 필요하다.

• Proceedings of the Korea Database Society Conference
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• 1994.09a
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• pp.49-69
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• 1994

A client/server system has become the computing architecture for the business organization which seeks competitive edges. Technically, a client/server system places application processing close to the user and thus increases performance. This paper's two primary goals are (i) to present a performance model for client/server database systems and (ii) to demonstrate analytically the effectiveness of client/server computing in comparison with other computing architectures via an illustrative example. The model is most likely to be used as a practical performance guide for client/server computing.

• Proceedings of the Korean Statistical Society Conference
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• 2002.11a
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• pp.293-298
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• 2002

We propose an improved version of Kim (2000) to the effect that in principle we may deal with a graphical model of any size. Kim (2000) proposed a method of estimating parameters for a model of categorical variables which is too large to handle as a single model. We applied the proposed method to a simulated data of 158 binary variables.

• Structural Engineering and Mechanics
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• v.24 no.5
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• pp.601-620
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• 2006

The paper presents an effective stiffness model for deformational analysis of reinforced concrete cracked members in bending throughout the short-term loading up to the near failure. The method generally involves the analytical derivation of an effective moment of inertia based on the smeared crack technique. The method, in a simplified way, enables us to take into account the non linear properties of concrete, the effects of cracking and tension stiffening. A statistical analysis has shown that proposed technique is of adequate accuracy of calculated and experimental deflections data provided for beams with small, average and normal reinforcement ratios.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.04a
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• pp.317-322
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• 1992

Developed in this reseach is a CAM system for 5-axis NC Machining of sculpture surfaces. We identify problems in generating 5-axis NC data and propose methods of overcoming them. Issues discussed in this report are; kinematic modelling of NC machines; Determination of cutter position(location and orientation); check of machine work-range; linear trajectory planning; calculation of feedrate number. The proposed system has been implemented in FORTRAN77 on the Personal IRIS EWS, and it also consitutes a module of the CAD/CAM system 'CASSETTE' developed in KIST CAD/CAM lab..

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.8
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• pp.1970-1975
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• 1996

The characteristics of data traffic on the Ethernet LAN are investigated on the basis of measurements. The analysis on the arrival pattern of packets on the network is found not to be a Poission process but to be Weibull distributions. An analysis of network traffic, packet arrivals are found to exhibit a 'source locality'. It is observed that file transfers are reponsible for about 92% of the traffic on the network. Our results will be useful for modelling purposes.

• Journal of Korean Society for Geospatial Information Science
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• v.1 no.2 s.2
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• pp.207-221
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• 1993

After characters of data were classified site planning and design, structure modelling was presented for computer system in site planning and design. Particularly, this study contributes to increase utilization site planning and design through result of estimation computer system in the land suitable analysis and soil design.

• Journal of Astronomy and Space Sciences
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• v.10 no.1
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• pp.1-16
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• 1993

Three typer of spin-axis attitude determination program for the geosynchronous transfer orbit spacecraft are developed. Deterministic closed-from algorithm, batch least-square algorithm and stabilized Kalman filter algorithm are used for implemetation of three programs. EUROSTAR bus model from British Aerospace is used for attitude sensor modelling. Attitude determinations using three programs are performed for the simulated sensor data according to INMARSAT 2-F1 prelaunch mission analysis.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.10a
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• pp.231-237
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• 2001

This paper presents some proposed methods for discontinuum analysis with rock discontinuities data acquisited in tunnel design stage. The limit equilibrium method for rock block sliding and falling proposed in this paper can consider the tunnel excavation and support stage, and, to the extent, the standard deviations and means of joint set orientation. Simple Distinct Elemet modelling methods are recommended in estimating the stability of tunnels in jointed rock masses. Because, the simple models are likely to show more consistent and clear than very complex model with finite joint length and joint deviation parameters.