• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.1
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• pp.37-45
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• 2009

In this study, experiments of development and application of 50 MPa high-performance concrete are performed for large dimensional tunnel linings. In order to produce 50MPa high-performance concrete, eight optimal mixtures replacing with fly ash and ground granulated blast furnace slag up to 50 percent of type I Portland cement were selected then tests for mechanical properties and simple adiabatic temperature rise tests were carried out. And in order to assess the quantitative characteristics of heat of hydrations of developed mixtures, three mixtures that the type I Portland cement (OPC) and each one mixture of binary and ternary mixtures (BS30, F15S35) were reselected, then the adiabatic temperature rise tests and mock-up tests were performed. Consequently, the comparisons between the results of mock-up tests and finite element analysis can be enhanced the reliability of analyzing routines of thermal behaviours of the developed high-performance concrete.

• Journal of the Korean Institute of Telematics and Electronics
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• v.14 no.6
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• pp.10-15
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• 1977

This paper proposes a simple and systematic method for the generation of the fault detection test sets for the combinational logic networks. Based on tile path sensitizing concept, the test patterns for the primary input gates of the network are defined, and then it is shown that, arranging these predefined test patterns according to the path sensitizing characteristics of the given network sturctures, the minimal complete test sets for the fan-out free combinational networks can be found easily. It is also shown that, taking into account the fan-out paths sensitizing compatibility, the proposed method can be extended to the irredundant reconvergent fan-out networks.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.6
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• pp.519-524
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• 2009

This work presents a simple technique to determine the Poisson's ratio of homogeneous solid material using a pair of low cost PVDF ultrasonic transducers. It is based on transducer's property of generating longitudinal and transversal waves depending on the excitation frequency. Mechanical tests were conducted to validate the proposed method, resulting in a good agreement between ultrasonic and mechanical techniques.

• Communications for Statistical Applications and Methods
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• v.10 no.2
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• pp.525-534
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• 2003

If a restriction is imposed only to a (proper) subset of parameters of interest, we call it a local restriction. Statistical inference under a local restriction in multinomial setting is studied. The maximum likelihood estimation under a local restriction and likelihood ratio tests for and against a local restriction are discussed. A real data is analyzed for illustrative purpose.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.207-212
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• 2001

The aim of this study is to present a practical and simple method for decision of ultimate failure mode of high-strength concrete beam members, based on interaction between shear strength and displacement ductility. Four tests were conducted on full-scale beam specimens having concrete compressive strength of 410kgf/$cm^{2}$. Prediction of failure mode from presented method and comparison with test results are also presented

• Journal of the Korean Operations Research and Management Science Society
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• v.24 no.2
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• pp.69-80
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• 1999

A genetic algorithm to determine the optimal signal sequence and double cycle pattern is described. The signal sequence and double cycle pattern are used as the input for TRANSYT to find optimal signal timing at each junction in the area traffic networks, In the genetic process, the partially matched crossover and simple crossover operators are used for evolution of signal sequence and double cycle pattern respectively. A special conversion algorithm is devised to convert the signal sequence into the link-stage assignment for TRANSYT. Results from tests using data from an area traffic network in Leicester region R are given.

• Journal of the Korean Society of Safety
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• v.9 no.1
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• pp.61-67
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• 1994

Rate of rise heat detectors that respond to the heat generated in fire plume and alarm when the temperature reaches a specified point, give a great influences to the loss of life and property according to their reaction sensitivity. In this study, simple equations were derived which can be predicted the response time and temperature of the rate of rise heat detector with the results of hot wind tunnel tests and compartment fire experiments.

• Architectural research
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• v.17 no.1
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• pp.31-40
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• 2015

A simple force-finding process based on an optimization technique is proposed for tensegrity structures. For this purpose, the inverse problem of form-finding process is formulated. Therefore, the position vector of nodes and element connectivity information are provided as priori. Several benchmark tests are carried out to demonstrate the performance of the present force-finding process. In particular, the force density distributions of simplex tensegrity are thoroughly investigated with the important parameters such as the radius, height and twisting angle of simplex tensegrity. Finally, the force density distribution of arch tensegrity is produced by using the present force-finding process for a future reference solution.

• Communications of the Korean Mathematical Society
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• v.13 no.1
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• pp.195-209
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• 1998

In this paper we present a new iteration method for solving optimization problems governed by partial differential equations. We generalize the existing methods such as simple gradient methods and pseudo-time methods to get an efficient iteration method. Numerical tests show that the convergence of the new iteration method is much faster than those of the pseudo-time methods especially when the parameter $\sigma$ in the cost functional is small.

• Journal of the Korean Statistical Society
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• v.25 no.4
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• pp.489-497
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• 1996

Lower bounds for the full level probabilities are derived under order restrictions in weights. Discussions are made on typical isotonic cones such as linear order, simple tree order, and unimodal order cones. We also discuss applications of these results for constructing conditional likelihood ratio tests for ordered hypotheses in a contingency table. A real data set on torus mandibularis will be analyzed for illustrating the testing procedure.