• Korean Journal Plant Pathology
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• v.13 no.1
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• pp.37-45
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• 1997

Disease incidence (DI), pre-emergence damping-off (PDO), days until the first symptom appeared (DUS), disease progress curve (DPC), and area under disease progress curve (AUDPC) were investigated in vivo after sowing ginseng seeds in each of 37 ginseng-cultivated soils which were sampled from 4 regions in Korea. Non linear fitting parameters, A, B, K and M, were estimated from the Richards' function, one of the disease progress models, by using the DI at each day from the bioassay. Inter- and intra-relationships between disease variables and stand-missing rate (SMR) in fields were investigated by using the simple correlation analysis. Disease variables of the root rot were divided into two groups: variables related to disease incidence, e.g., DI, AUDPC and A parameter, and variables related to disease progress, e.g., B, K and M parameters. DI, AUDPC, and DUS had significant correlations with SMR in ginseng fields, and then it showed that the disease development in vivo corresponded with that in fields. Soil samples could be separated into 3 and 4 groups, respectively, on the basis of the principal component 1 (PC1) and the principal component 2 (PC2), which were derived from the principal component analysis (PCA) of Richards' parameters, A, B, K and M. PC1 accounted for B, K and M parameters, and PC2 accounted for A parameter.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.4
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• pp.11-19
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• 2011

PADDIMOD2 was deloped to estimate nonpoint source pollution from paddy rice fields. The PADDIMOD2 was enhanced to estimate runoff and pollutant load during non-growing as well as growing season and to be easily used for public by development of Excel based system. Nutrient concentration and hydrology were based on Dirac delta function and continuous source function, and tank model for growing season and Event Mean Concentrations (EMCs) and SCS-Curve Number method for non-growing season. The PADDIMOD2 consists of three main component (input data, parameters data, and output data) by including eight Excel spread sheets. As a result of model application, total precipitation and irrigation were 1,051.7 mm and 439.2 mm, respectivley and surface runoff and water loss including infiltration and evapotranspiration were 463.0 mm and 947.9 mm, respectively. Annual nutrient loadings of T-N and T-P from study area were 6.7 kg/$km^2$/day and 0.5 kg/$km^2$/day, respectively. Development of PADDIMOD2 was focused on minimizing input data and maximizing user friendly system and is expected to be useful tool to evaluate various non-structure BMPs and estimate unit load from paddy rice fields for application at Korean TMDL.

• The Transactions of the Korea Information Processing Society
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• v.6 no.11
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• pp.2863-2874
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• 1999

Apartment auction is a system that is used for the citizens to get a house. This paper deals with the implementation of a web-based intelligent decision support system using OLAP technique and data mining technique for auction decision support. The implemented decision support system is working on a real auction database and is mainly composed of OLAP Knowledge Extractor based on data warehouse and Auction Data Miner based on data mining methodology. OLAP Knowledge Extractor extracts required knowledge and visualizes it from auction database. The OLAP technique uses fact, dimension, and hierarchies to provide the result of data analysis by menas of roll-up, drill-down, slicing, dicing, and pivoting. Auction Data Miner predicts a successful bid price by means of applying classification to auction database. The Miner is based on the lazy model-based classification algorithm and applies the concepts such as decision fields, dynamic domain information, and field weighted function to this algorithm and applies the concepts such as decision fields, dynamic domain information, and field weighted function to this algorithm to reflect the characteristics of auction database.

• Journal of the Chungcheong Mathematical Society
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• v.19 no.4
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• pp.319-324
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• 2006

Let K be a finite cyclic extension of $k=\mathbb{F}_q(T)$ of prime degree ${\ell}$. Let ${\tilde{\mathcal{C}}}l_{K,{\ell}}$ be the Sylow ${\ell}$-subgroup of the ideal class group ${\tilde{\mathcal{C}}}l_K$ of $\mathcal{O}_K$. The structure of ${\tilde{\mathcal{C}}}l_{K,{\ell}}$ as $\mathbb{Z}_{\ell}[G]$/<$N_G$>-module is determined the dimensions $${\lambda}_i\;:=dim_{\mathbb{F}_{\ell}}({\tilde{\mathcal{C}}}l_{K,{\ell}}^{({\sigma}-1)^{i-1}}/{\tilde{\mathcal{C}}}l_{K,{\ell}}^{({\sigma}-1)^i})$$ for $i{\geq}1$. In this paper we investigate the dimensions ${\lambda}_1$ and ${\lambda}_2$.

• Bulletin of the Korean Mathematical Society
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• v.44 no.2
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• pp.233-239
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• 2007

Let $\mathbb{A}=\mathbb{F}_q$[T] be the polynomial ring over a finite field $\mathbb{F}_q$[T] and K=$\mathbb{F}_q$(T) its field of fractions. Let ${\ell}$ be a fixed prime divisor of q-1. Let J be a finite set of monic irreducible polynomials $P{\in}{\mathbb{A}}$ with deg $P{\equiv}0$ (mod ${\ell})$. In this paper we define the group $C_K$ of circular units in K=k$(\{\sqrt[{\ell}]P\;:\;P{\in}J\})$ in the sense of Kucera [4] and compute the index of $C_K$ in the full unit group $O^*_K$.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.3
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• pp.124-133
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• 1995

A theoretical self-consistent thermoelectric model has been developed for optimal thermal design in the self-signal processing infraed detectors. The model is achived by employing the coupled thermoelectric equation which allows which allows the simultaneous investigation of the termal and electrical aspects of device behavior. The thermal limitation of detectivity and responsivity are determined by the enegy gap, carrier concentration, lifetime, and mobility as a function of the temperature. The calculated results indicate that the detectivity is decreased at bias fields above about 50 V/cm, because the performence is limiting by temperature when the bias voltage reached the level associated with Joule heating. It has been also found that the improvement in the mid-band modulation transfer function(MTF) may be restricted by increasing the bias fields. Further, the important paramerers in the thermal optimization of SPIR detector, such as temperature in the device, ambipolar velocity, element thickness and length, are also considered. The analytical study provides a mathematical basis for optimal design of such a photoconductive IR detector and the agreement between the experimental and theoretical results are seen to be good.

• Bulletin of the Korean Mathematical Society
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• v.29 no.2
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• pp.277-283
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• 1992

Let GF(q) be a finite field with q elements where q=p$^{n}$ for a prime number p and a positive integer n. Consider an arbitrary function .phi. from GF(q) into GF(q). By using the Largrange's Interpolation formula for the given function .phi., .phi. can be represented by a polynomial which is congruent (mod x$^{q}$ -x) to a unique polynomial over GF(q) with the degree < q. In [3], Wells characterized all polynomial over a finite field which commute with translations. Mullen [2] generalized the characterization to linear polynomials over the finite fields, i.e., he characterized all polynomials f(x) over GF(q) for which deg(f) < q and f(bx+a)=b.f(x) + a for fixed elements a and b of GF(q) with a.neq.0. From those papers, a natural question (though difficult to answer to ask is: what are the explicit form of f(x) with zero terms\ulcorner In this paper we obtain the exact form (together with zero terms) of a polynomial f(x) over GF(q) for which satisfies deg(f) < p$^{2}$ and (1) f(x+a)=f(x)+c for the fixed nonzero elements a and c in GF(q).

• 한국연소학회:학술대회논문집
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• 2002.11a
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• pp.11-17
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• 2002

The first-order conditional moment closure (CMC) model is applied to $CH_4$/Air turbulent jet diffusion flames(Sandia Flame D, E and F). The flow and mixing fields are calculated by fast chemistry assumption and a beta function pdf for mixture fraction. Reacting scalar fields are calculated by elliptic CMC formulation. The results for Flame D show reasonable agreement with the measured conditional mean temperature and mass fractions of major species, although with discrepancy on the fuel rich side. The discrepancy tends to increase as the level of local extinction increases. Second-order CMC may be needed for better prediction of these near-extinction flames.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.205-209
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• 1994

The main purpose of this study is constructing new velocity fields on the base of shape function used in finite element method and showing the possibility of application it to metal forming processes. Utilizing the 8-node quadratic rectangular element, we expressed the velocity within the deformation region by interpolating the velocity of each nodal points. And the upper-bound formulation from this velocity fields was derived. In order to confirm the validity of this method we applied it to axisymmetic combined extrusion problem. the results of load show that this method is on better agreement with experiment than the conventional UBET, and also the flow pattern and profile of extruded part are reasonable.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.2
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• pp.186-191
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• 2001

A crack with electrically impermeable surfaces in an electrostrictive material subjected to uniform electric loading is analysed. The effect of electric yielding on stress intensity factor is investigated by using a small scale yielding model and a strip yield zone model. Complete forms of electric fields and elastic fields are derived by using complex function theory. The electrical yield zone shapes for two models are different each other. The two models, however, predict similar yield zone sizes under the small scale yielding conditions. It is found that the influence of electric yielding on the stress intensity factor is insensitive to the modeling of the electrical yield zone shape.