• Computers and Concrete
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• 제6권3호
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• pp.203-223
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• 2009

Regression analysis (RA) can establish an explicit formula to predict the strength of High-Performance Concrete (HPC); however, the accuracy of the formula is poor. Back-Propagation Networks (BPNs) can establish a highly accurate model to predict the strength of HPC, but cannot generate an explicit formula. Genetic Operation Trees (GOTs) can establish an explicit formula to predict the strength of HPC that achieves a level of accuracy in between the two aforementioned approaches. Although GOT can produce an explicit formula but the formula is often too complicated so that unable to explain the substantial meaning of the formula. This study developed a Backward Pruning Technique (BPT) to simplify the complexity of GOT formula by replacing each variable of the tip node of operation tree with the median of the variable in the training dataset belonging to the node, and then pruning the node with the most accurate test dataset. Such pruning reduces formula complexity while maintaining the accuracy. 404 experimental datasets were used to compare accuracy and complexity of three model building techniques, RA, BPN and GOT. Results show that the pruned GOT can generate simple and accurate formula for predicting the strength of HPC.

• 대한한의학방제학회지
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• 제20권2호
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• pp.47-54
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• 2012

Objectives : This study aimed to build up information system for the 25 cases of Korean Medicine (KM) prescriptions which are used mostly often in clinic and aimed to offer information about its effect and safety to public and researcher. Methods : We used KM prescription data-bank which came from 'The Bio-informatics for herbal formula' and 'The evidence based medicine for herbal formula' projects of Korean Institute of Oriental Medicine (KIOM) Results : First, we analyzed prescription data and categorized 7 classes, then we built up prescription database based on it. Second, we designed and developed user functions of prescription information system, then we link it to OASIS. Third, we developed adminstration system to manage the prescription data. Conclusions : From this study we hope that KM prescription information system will be used for fusion research based on KM. Because the implemented system is linked to OASIS, we expect it will be widely used.

• Journal of Welding and Joining
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• 제28권1호
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• pp.92-99
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• 2010

For the last couple of decades many studies have been carried out to find out solutions to improve the effectiveness and productivity of the plate forming process. The practical way for the automation of the plate forming process has not been, however, developed yet. Since the characteristics of heating machines may be different form each other, it is necessary to investigate the thermal deformation characteristics of the heating machine to be used in the automation system. And their characteristics may be updated as new information about thermal deformation by heating is accumulated. In this paper, data base system has been constructed based on the results of experiments and numerical analyses, which will be used in deriving the deformation estimation formula. The computer code which can automatically derive the deformation estimation formula has been also developed. This paper also illustrates how the formula is updated as experimental data are added. From the present findings, it can be said that the automatic deriving procedure may be important in the automated plate forming system since the heating line information to be generated must be directly influenced by the deformation estimation formula.

• 한국지반환경공학회 논문집
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• 제17권7호
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• pp.27-33
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• 2016

This study expanded Terzaghi arching formula, which assumed a vertical surface as a sliding surface, to consider an arbitrarily inclined surface as a sliding surface and examined the effect of a sliding surface. This study firstly developed a formula to expand the existing Terzaghi arching formula to consider an inclined surface as well as a vertical surface as a sliding surface under the downward movement of a trap door. Using the expanded formula, the effect of excavation, ground, and surcharge conditions on a vertical stress was examined and the results were compared with them from Terzaghi arching formula. The comparison indicated that the induced vertical stress was highly affected by the angle of an inclined sliding surface and the degree of influence depended on the excavation, ground, and surcharge conditions. It is expected that the results from this study would provide a better understanding of various arching phenomenon in the future.

• 물과 미래
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• 제11권1호
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• pp.47-58
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• 1978

This study is concerned with the analysis of the formulas which give both the quantity of the total, suspended and bed loads as functions of stream and sediment characteristics. The numerical analysis of sediment discharge formulas is described and the computer program for the following 4 formulas are developed; (1) Einstein's Formula (2) Toffaleti's Formula (3) Brown's Formula (4) Kikkawa's Formula In the analysis of these formulas, the hydraulic data of the river in the downstream of the Han River are used, and these formulas have been tested by application and comparison with observed data and the results computed by the computer. In these methods and procedures, the most satisfactory and convenient formula is selected. The design and planning of the river channel regulation works are determined by computing the river bed variation by using the sediment discharge computed from the selected formula.

• 한국해안·해양공학회논문집
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• 제25권3호
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• pp.138-146
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• 2013

Tetrapod는 국내외에서 널리 사용되는 경사식 방파제의 대표적인 피복재이다. Tetrapod의 소요중량을 산정하기 위해 많은 연구자들이 다양한 안정식을 제안하였다. 기존 안정식은 수리실험자료를 곡선맞춤하여 산정하기 때문에 많은 불확실성을 포함하고 있다. 대표적인 불확실성은 실험자료의 불확실성, 안정식 산정방법의 불확실성, 그리고 확률변수의 불확실성이다. 본 연구에서는 안정식 산정 방법의 불확실성을 낮추기 위해 M5' model tree를 사용하여 Tetrapod의 안정식을 개발하였다. 개발된 안정식의 예측능력을 평가하기 위해 일치지수를 사용하였으며, 새 안정식은 여러 가지 모델에서 기존 안정식보다 약 0.1 정도 큰 일치지수를 보였다. 또한 기존 안정식은 안정수 3.0 이상에서 예측능력이 현격히 감소하는데 반해 새 안정식은 안정수의 크기에 관계없이 일정한 예측능력을 보였다. 결과적으로 새로 개발된 안정식은 예측능력이 우수할 뿐 아니라 기존 안정식과 유사하게 명시적인 공식으로 표현된다.

• Journal of applied mathematics & informatics
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• 제19권1_2호
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• pp.105-125
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• 2005

Motivated by the field experimental designs in agriculture, the theory of block designs has been applied to several areas such as statistics, combinatorics, communication networks, distributed systems, cryptography, etc. An explicit formula and its fast computational algorithm for a class of symmetric balanced incomplete block designs are presented. Based on the formula and the careful investigation of the modulus multiplication table, the algorithm is developed. The computational costs of the algorithm is superior to those of the conventional ones.

• East Asian mathematical journal
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• 제29권5호
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• pp.545-550
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• 2013

A remarkably large number of integral formulas have been investigated and developed. Certain large number of integral formulas are expressed as derivatives of some known functions. Here we choose to recall such a formula to present explicit expressions in terms of Gamma function, Psi function and Polygamma functions. Some simple interesting special cases of our main formulas are also considered. It is also pointed out that the same argument can establish explicit integral formulas for other those expressed in terms of derivatives of some known functions.

• 한국환경과학회지
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• 제23권11호
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• pp.1775-1790
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• 2014

The regional rainfall intensity formula for Gimhae in Gyeongsangnam-do province is developed in this study. The nine points of rainfall observations were selected. In order to demonstrate the accuracy and the versatility of the proposed rainfall intensity formula, three regions under the jurisdiction of the Meteorological Agency near Gimhae, namely Busan, Changwon, Miryang observatories were selected. The present formula can be effectively employed for various design of hydraulic structures in Gimhae area since it is divided into several refined regions.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(II)
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• pp.170-175
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• 2003

The ASCE formula of pipeline' soil interaction force is the basis of semi-analytical relationship for buried pipelines subjected to longitudinal permanent ground deformation due to seismic induced liquefaction. However, since the ASCE formula has been developed based on the stiffness of non-liquefied region, it is needed to modify for the varied stiffness of liquefied region. With this object, the consideration of decreasing effect of soil stiffness in liquefied region is made: i.e. the spatial distributions of pipeline. soil interaction force in liquefied region. It means that the improved formula can reflect various patterns of permanent ground deformation more realistically. Through the comparative analyses using both the improved and ASCE formula, the applicability of the improved, the limitation of the existing formula and semi-analytical relationship are discussed.