• Computers and Concrete
• /
• v.23 no.4
• /
• pp.255-265
• /
• 2019

The potential of using genetic programming to predict engineering data has caught the attention of researchers in recent years. The present paper utilized weighted genetic programming (WGP), a derivative model of genetic programming (GP), to model the compressive strength of concrete. The calculation results of Abrams' laws, which are used as the design codes for calculating the compressive strength of concrete, were treated as the inputs for the genetic programming model. Therefore, knowledge of the Abrams' laws, which is not a factor of influence on common data-based learning approaches, was considered to be a potential factor affecting genetic programming models. Significant outcomes of this work include: 1) the employed design codes positively affected the prediction accuracy of modeling the compressive strength of concrete; 2) a new equation was suggested to replace the design code for predicting concrete strength; and 3) common data-based learning approaches were evolved into knowledge-based learning approaches using historical data and design codes.

• Journal of Biosystems Engineering
• /
• v.11 no.1
• /
• pp.52-63
• /
• 1986

This study was performed to find out drying characteristics and develop drying model for the design of an efficient dryer or drying system of red peper. The basic model which describes drying phenomenon of red pepper was firstly established, and drying tests were conducted at 14-different drying conditions. In this test, the effects of drying air temperature and relative humidity on the rate of drying were undertaken. Finally, a new drying model based on these experimental results was developed to describe the drying characteristics of red pepper. The results from this study may be summarized as follows. 1. Drying constant of the basic model established from Lewis' experimental model and diffusion equation was theoretically deduced as a function of moisture content and inner-temperature of red pepper. 2. From the results of drying tests, drying air temperature was found to have the greatest effect on the rate of drying. However, the effect of temperature was small for the condition of high relative humidity, and for low temperature, the effect of relative humidity was found to be large even though the range of relative humidity was low. 3. Modified Henderson equation was found to be better than Chung equation as the EMC model for the estimation of the equilibrium moisture content of red Pepper. 4. Constant-rate drying period did not exist in the red pepper drying test. And falling-rate drying period was divided into three distinct phases. Drying rate was dependent on the moisture content, the inner-temperature of red pepper and the change of physical property due to drying. 5. Drying constant increased with decrease of free moisture content, but it decreased at the end of the drying period. Also, drying constant was dependent on the drying air temperature and relative humidity. 6. The new drying model developed in this study was found to be most suitable in describing the drying characteristics of red pepper. Therefore, it may be concluded that drying time could be accurately estimated by the new drying model.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2004.08a
• /
• pp.217-225
• /
• 2004

Introduction of wave model, considered the effect of shoaling, refraction, diffraction, partial reflection, bottom friction, breaking at the coastal waters of complex bathymetry, is a very important factor for most coastal engineering design and disaster prevention problems. As waves move from deeper waters to shallow coastal waters, the fundamental wave parameters will change and the wave energy is redistributed along wave crests due to the depth variation, the presence of islands, coastal protection structures, irregularities of the enclosing shore boundaries, and other geological features. Moreover, waves undergo severe change inside the surf zone where wave breaking occurs and in the regions where reflected waves from coastline and structural boundaries interact with the incident waves. Therefore, the application of mild-slope equation model in this field would help for understanding of wave transformation mechanism where many other models could not deal with up to now. The purpose of this study is to form a extended mild-slope equation wave model and make comparison and analysis on variation of harbor responses in the vicinities of Ulsan Harbor and Ulsan New Port, etc. due to construction of New Port in Ulsan Bay. This type of trial might be a milestone for port development in macro scale, where the induced impact analysis in the existing port due to the development could be easily neglected.

• Journal of Biosystems Engineering
• /
• v.18 no.4
• /
• pp.344-350
• /
• 1993

The purpose of this study is to develop design equations to calculate optimum specifications and dimensions such as weight, engine horsepower, etc. of the tractor necessary to perform stable rotary tillage. The main results of this study are as follows. 1. A wheel-lug ought to receive a special resistance in downward direction which resists the lug's upward motion on wet sticky soil surface. The authors introduce a new academic name of the "lift resistance(上昇抵抗力, 상승저항력)" for such a force which resists retraction of a wheel lug from the soil in the upward trochoidal motion. This force is composed of the frictional force acting on the trailing and the leading lug side, and the "perpendicular adhesion(鉛直付着力, 연직부착력)" acting on the lug face and the undertread face on adhesive soil. 2. The "lift resistance ratio(上昇抵抗力係數, 상승저항력계수)" and the "perpendicular adhesion ratio(鉛直付着力係數, 연직부착력계수)" were defined, which are something similar to the definition of the motion resistance ratio, the traction coefficient, etc. 3. The design equation of the optimum weight of a rotary tiller mounted on the tractor derived by calaulating the forces acting on the rotary blades. 4. The design equations to calculate optimum specifications and dimensions such as weight, engine horsepower, etc. of the tractor necessary to perform stable rotary tillage were derived. It becomes clear that the optimum weight of a rotary tiller and a tractor can be estimated in planning design by means of putting about 21 design factors of the target into the equation. These equations are useful for planning design to estimate the optimum dimensions and specifications of a rotary tiller as well as a tractor by the use of known and/or unknown design parameters.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.7
• /
• pp.1929-1940
• /
• 1999

In this paper a VLSI design for the automatic magnetizing and inspection system has been presented. This is a design of a peripheral controller, which magnetizes CRTs and computer monitors and controls the automatic inspection system. We implemented a programmable peripheral interface(PPI) circuit of the control and protocol module for the magnetizer controller by using a 0.8um CMOS SOG technology of ETRI. Most of the PPI functions have been confirmed. In the conventional method, the propagation/ramp delay model was used to predict the delay of cells, but used to model on only a single cell. Later, a modified "linear delay predict model" was suggested in the LODECAP(LOgic DEsign CAPture) by adding some factors to the prior model. But this has not a full model on the delay chain. In this paper a new " delay predict equation" for the design of the timing control block in PPI system has been suggested. We have described the detail method on a design of delay chain block according to the extracted equation and applied this method to the timing control block design. And we had descriptions on the other blocks of this system.

• Journal of the Korea Concrete Institute
• /
• v.23 no.2
• /
• pp.211-217
• /
• 2011

Although a compression splice length does not need to be longer than a tension splice length due to end bearing effect, current design codes impose a longer compression lap splice than a tension lap splice in high strength concrete. Hence, new criteria for the compression lap splice including concrete strength effect need to be found for economical design of ultra-high strength concrete. An experimental study has been conducted using column specimens with concrete strength of 80 and 100 MPa with transverse reinforcement. The test results showed that splice strengths improved when the amount of transverse reinforcement increased. However, end bearing strength did not increase when larger amount of transverse reinforcement is provided within the spliced zone. Therefore, the splice strength enhancement was attributed to the improvement of bond. From regression analysis of 94 test results including specimens made with concrete strength of 40 and 60 MPa, a new design equation is proposed for compression lap splice in the concrete compressive strength ranging from 40 to 100 MPa with transverse reinforcement. By using the proposed equation, the incorrect design equations for lap splice lengths in tension and compression can be corrected. In addition, the equation has a reliability equivalent to those of the specified strengths of materials.

• Journal of Power Electronics
• /
• v.16 no.3
• /
• pp.1131-1140
• /
• 2016

A simple design for a sliding mode observer is proposed for EV lithium battery SOC estimation in this paper. The proposed observer does not have the limiting conditions of existing observers. Compared to the design of previous sliding mode observers, the new observer does not require a solving matrix equation and it does not need many observers for all of the state components. As a result, it is simple in terms of calculations and convenient for engineering applications. The new observer is suitable for both time-variant and time-invariant models of battery SOC estimation, and the robustness of the new observer is proved by Liapunov stability theorem. Battery tests are performed with simulated FUDS cycles. The proposed observer is used for the SOC estimation on both unchanging parameter and changing parameter models. The estimation results show that the new observer is robust and that the estimation precision can be improved base on a more accurate battery model.

• Journal of the Korea Concrete Institute
• /
• v.20 no.2
• /
• pp.193-202
• /
• 2008

Seismic design for bridge columns of the current Korea Highway Bridge Design Specifications which adopt full ductility design concept results in reinforcement congestion problems in construction site. It is due to large amount of confining steel is required even for small ductility demand which is a normal case in low and moderate seismicity regions like Korean peninsular. Therefore a new seismic design method based on limited ductility concept was proposed, which is called ductility demand based design method. It uses the new confining steel design equation considering ductility demand and aspect ratio of the column as well as material strength. The purpose of this study is to verify safety of the ductility demand based design method by the confining steel design equation. Eighty nine circular column test results are selected and investigated in terms of ductility factor and its safety. The safety factor for the circular column test results ranges between 1.11 and 3.98, and the average is 1.90. In this paper, the basic concept and detailed design procedure of the ductility demand based design method are also introduced as well as the investigation of the safety with respect to the major variables in confining steel design.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2005.11a
• /
• pp.89-92
• /
• 2005

Recently there have been occurred many loss of life and extensive damage to social infrastructures due to moderate and strong earthquakes all over the world. In this research, major design factors have been evaluated for the establishment of the rational seismic design code of rectangular RC bridge piers. It was concluded from this study that the axial force ratio and the longitudinal steel ratio should be the most important influencing design parameter for the seismic displacement ductility. However those parameters are not considered in the confinement steel ratio of the KHBDS. Thus, the objective of this study is to propose a rational design equation for transverse reinforcements of rectangular RC bridge piers. New confinement steel ratio is proposed by introducing the effect of the axial force and the longitudinal steel to the current KHBDS. It is thought that these new codes could release the rebar congestion problem in the plastic hinge region of RC bridge piers which contribute to the enhancement of constructibility and economization for RC bridge construction.

• Journal of Korean Society on Water Environment
• /
• v.26 no.1
• /
• pp.140-147
• /
• 2010

In existing design method for aeration tank water temperature was considered as governing variable for applying safety factor. This study tried a few new approach of aeration tank design using SOUR at various temperature conditions. Specific substrate utilization rate (U) and specific oxygen uptake rate (SOUR) both were analyzed at various temperature and SRT. The laboratory scale reactor was operated on various temperature ($10^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$) and SRT (5day, 10day, 20day, 30day). In this study, SOUR tended to increase with the temperature increased. On the other hand, SOUR tended to decrease when SRT increased from 5 days to 30 days. Empirical equations were obtained SOUR=a/SRT+b and $SOUR=(a/m){\cdot}U+(b-a(n/m))$ from the relationship between SRT, U and SOUR. Empirical equations shows the possibility as a new design method for the aeration basin.