• Korean Journal of Agricultural Science
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• v.43 no.4
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• pp.537-546
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• 2016

The development of models for agriculture systems, especially for crop production, has supported the prediction of crop yields under various environmental change scenarios and the selection of better crop species or cultivar. Crop models could be used as tools for supporting reasonable nutrient management approaches for agricultural land. This paper outlines the simplified structure of main crop models (crop growth model, crop-soil model, and crop-soil-environment model) frequently used in agricultural systems and shows diverse application of their simulated results. Crop growth models such as LINTUL, SUCROS, could provide simulated data for daily growth, potential production, and photosynthesis assimilate partitioning to various organs with different physiological stages, and for evaluating crop nutrient demand. Crop-Soil models (DSSAT, APSIM, WOFOST, QUEFTS) simulate growth, development, and yields of crops; soil processes describing nutrient uptake from root zone; and soil nutrient supply capability, e.g., mineralization/decomposition of soil organic matter. The crop model built for the DSSAT family software has limitations in spatial variability due to its simulation mechanism based on a single homogeneous field unit. To introduce well-performing crop models, the potential applications for crop-soil-environment models such as DSSAT, APSIM, or even a newly designed model, should first be compared. The parameterization of various crops under different cultivation conditions like those of intensive farming systems common in Korea, shortened crop growth period, should be considered as well as various resource inputs.

• The Journal of Information Technology and Database
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• v.2 no.2
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• pp.25-34
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• 1995

In this paper, we present design philosophy and implementation issues of a functionality testing tool for object-oriented database systems. A testing tool has been developed to validate UniSQL/X functionalities with C++ interface. A testing tool is designed under consideration of scaleability, simplicity and extendibility. The schema is deliberately constructed to verify the object-oriented functionalities such as abstraction, inheritance and aggregation. Each test item has been derived under various black box techniques such as equivalent partitioning and boundary-value analysis. The testing tool consists of six phases, namely, database creation, database population, construction of testindex, compilation and link, execution and result reporting, and final cleanup. The prototype provides more than 140 test items at 90 programs.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.35T no.2
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• pp.13-19
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• 1998

The Median of a set of number is a number which partitions the given set. The specified numbers of a set partitions in one subset and in another subset. In Image Processing, The Sorting method of numbers of one subset equal to the previous Median Filtering. but The Sorting method of numbers of another subset not equal to in the other. In this paper, a fast two-dimentional Median Filtering Algorithm is proposed. The Algorithm designed in such a during the partitioning of the previous window are used. Test results obtained by running the Algorithm on IBM PC(586) are presented and its filtering. It is shown that the proposed Algorithm's processing time is faster and independent of the number of bits used to represent the data values.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.2
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• pp.123-134
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• 2000

This paper addresses a new triangulation method for constructing surface model from a set of wire-frame contours. The most important problem of contour triangulation is the branching problem, and we provide a new solution for the double branching problem, which occurs frequently in real data. The multiple branching problem is treated as a set of double branchings and an algorithm based on contour merging is developed. Our double branching algorithm is based on partitioning of root contour by Toussiant's polygon triangulation algorithml[14]. Our double branching algorithm produces quite natural surface model even if the branch contours are very complicate in shape. We treat the multiple branching problem as a problem of coarse section sampling in z-direction, and provide a new multiple branching algorithm which iteratively merge a pair of branch contours using imaginary interpolating contours. Our method is a natural and systematic solution for the general branching problem of contour triangulation. The result shows that our method works well even though there are many complicated branches in the object.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.4
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• pp.231-237
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• 1995

The objective of this study is to obtain the basic data for investigating the effects of organic reserves on winter survival or regrowth yield. Forage rape (Brassica napus L.) was sown by three seeding densities of 5, 15 and 25cm interval among plants on Sep. 1, 1994. Field-grown plants were sampled on the before wintering (Dec. 4) and on the wintering period (Jan. 16) to analyze the nitrogen and non-structural cahohydrate reserves. The rate of winter survival and regrowth yield were also measured in the spring of next year. The dry matter yields from the plots of 5, 15 and 25cm seeding interval were 1,270, 1.01 9 and 1,062 kg/lOa respectively, on the before wintering. The similar pattern wa5 observed in the crude protein yields affected by seeding density. On the before wintering, both of nitrogen and starch contents per plant significantly increased as the seeding density was lowered. Starch content was relatively higher than that of nitrogen in all plots. On the wintering period, the contents of nitrogen reserves were 6.5, 41.2 and 121.7 mglplant, those of starch reserves were 1.0, 5.4 and 185.1 mg/plant, respectively, in the plots of 5, 15 and 25cm seeding interval. Nitrogen reserves on the wintering period increased while starch reserves highly decreased in all plots comparing to the before wintering. 'lhe rates of winter survival were 10.2, 20.6 and 37.1%, and regrowth yields were 76, 96 and 178 kgD.M/ IOa, respectively, in the plots of 5, 15 and 25cm seeding interval. These results cleariy showed that seeding density have a close influence on the level of nitrogen and non-structurd cahohydrate reserves, and that the rate of winter survival and regrowth yield were controlled by reserves level on the wintering period.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.4
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• pp.238-244
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• 1995

The objective of this study is to obtain the basic data for investigating the effects of organic reserves on winter survial or regrowth yield. Forage rape(Brassica napus L.) was sown on Sep. 1, 1994. Experimental plots were divided into three replicates under 6 different cutting dates(l0 days interval from Oct. 15 to Dec. 4). Field-grown palnts were sampled on the each cutting date and on the wintering period (Jan. 16) to analyze the nitrogen and non-structural cahohydrate reserves. The rate of winter survival and regrowth yield were also measured in the spring of next year. On the before wintering, dry matter yields were 152, 274, 500, 718, 776 and 981 kg/lOa, respectively, from the cutting date on Oct. 15, Oct. 25, Nov. 4, Nov. 14, Nov. 24, and Dec. 4. Cmde protein yield significantly increased as cutting date was later until Nov. 14, thereafter a significant increase did not occured. Nitrogen and starch contents per plant significnatly increased as the cutting date was later. The increasing rate of starch was greatly higher than that of nitrogen. On the wintering period, nitrogen reserves in mts were 85.3, 68.8, 47.6, 28.3, 44.3, and 55.3 mglplant, and starch reserve were 11 1.3, 75.3, 39.3, 19.6, 26.4 and 34.6 mglplant, respectively, in the plots cut on Oct. 15, Oct. 25, Nov. 4, Nov. 14, Nov. 24, and Dec. 4. It showed that carbohydrate reserves were much highly utilized than nitrogen reserves during wintering period. The rates of winter survival were 91, 83, 46, 22, 35 and 43% and regrowth yields were 692, 545, 316, 84, 127 and 140 kgD.M/lOa, respectively, in each plots. The highly significant correlation (p<0.01) between the level of organic reserves and the rate of winter survival or regrowth yield were obtained.

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.1
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• pp.1-8
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• 1996

The objective of this study is to obtain the basic data for investigating the effects of organic reserves on winter survial or regrowth yield. Forage rape (Brussicu napus L.) was sown at 10 day> interval from Sep. I to Nov. 1. Field-grown palnts were sampled on the before wintering (Dec. 4) and on the wintering period (Jan. 16) to analyze the nitrogen and non-structural cahohydrate reserves. The rate of winter survival and regrowth yield were also measured in the spring of next year. On the before wintering, the dry matter yields from the plots sown on Sep. 1, Sep.11 and Sep. 21 were 860, 596 and 260 kg/lOa, respectively. No. harvest was canied out on the plots sown after Oct. 1 because the growth state was not enough to cut. Both of nitrogen and starch contents per plant significantly increased as the seeding date was later. On the wintering period, the contents of nitrogen reserves in roots were 176.8. 120.1, 71.7, 84.0, 72.1, 45.3 and 33.3 mg/plant, those of starch reserves were 199.0. 55.8, 21.8, 92.6, 86.5, 36.4 and 29.0 mglplant, resepctively, in the plots sown on Sep. 1, Sep. 11, Sep. 21, Oct. I, Oct. 11, Oct. 21 and Nov. 1. The rates of winter survival were 40, 36, 33, 85, 87, 59 and 49% and regrowth yields were 161, 86, 65, 520, 451, 121 and 33 kgD.M/lOa, respectively, in each plots. 'Ihese results clearly showed that seeding date has a close influence on the level of organic reserves and forage yield, and that the possibility of continuous utilization on the before and alter wintering is extremely limited by seeding date.

• Journal of Korea Multimedia Society
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• v.7 no.3
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• pp.388-398
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• 2004

This paper focuses on the reduction method of message traffic occurred when multiple participants collaborate in the distributed virtual environment. It is referred to as filtering method of update message to minimize data traffic exchanged in the virtual environment, and it is the essential process to improve the scalability of the virtual environment. Spatial partitioning method, a popular filtering technique, divides the whole environment into smaller sub-parts in order to make it small the regions to be maintained consistently. However, it is less flexible and adaptable because the information of area of interest must be configured before simulation. In this paper, the concept of dynamic area of interest is proposed, which is highly adaptable by applying dynamic environmental elements to AOI management. It uses multiple layering and multiple consistency algorithms for dynamic management, and makes it possible to consume system resource efficiently. For performance evaluation, experiments are performed with virtual avatars, measuring message traffic. Finally, the proposed model could be applied to the AOI management systems which accommodate massive users like MMORPG, or virtual communities.

• Journal of Korea Multimedia Society
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• v.8 no.1
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• pp.79-87
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• 2005

In e-commerce applications, a public key cryptosystem is an important and indispensible element for the basic security operations such as authentication, digital signaturing, and key distribution. In wired network environments, the public key infrastructure certificate, which is based on X.509 specification, has been widely used. On the other hand, it still remains difficult to use the certificate information in wireless network environments due to the inherent limitations of the hand-held devices such as low computational power and short battery life. In this paper, we facilitate a codesign approach by implementing a software public-key cryptosystem and classifying its internal computation overheads quantitatively using a software profiling technique. Moreover, we propose a method to analyze the profiled data and apply it to the problem of software/hardware partitioning in a codesign approach. As an illustrative example, we analyze the computational overheads of an EC-Elfagamal application and examine a critical computational path.

• International Journal of Industrial Entomology and Biomaterials
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• v.35 no.1
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• pp.51-57
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• 2017

The tiny dragonfly, Nannophya pygmaea (Odonata: Libellulidae), is an endangered insect in South Korea. Previously, a partial mitochondrial DNA sequence that corresponded to a DNA barcoding region has been used to infer genetic diversity and gene flow. In this study, we additionally sequenced the barcoding region from N. pygmaea that had been collected from three previously sampled populations (40 individuals) and these sequences were combined with the preexisting data. We also selected and sequenced an additional mitochondrial gene (ND5) to find further variable gene regions in the mitochondrial genome. DNA barcoding sequences of 108 individuals from five South Korean localities showed that genetic diversity was highest in Gangjin, Jeollanam-do Province. Muuido, which was previously occupied by a single haplotype, was also found to have an identical haplotype, which confirmed the low genetic diversity on this islet. Gene flow among populations is highly limited, and no clear distance- or region-based geographic partitioning was observed. Phylogenetic relationships among haplotypes showed that there were no discernable haplotypes in South Korea. ND5 provided slightly more haplotypes compared to the barcoding region in 40 individuals (14 vs. 10 haplotypes in the COI gene). It also had a slightly higher within-locality diversity estimate, which suggested that ND5 had potential as mitochondrial DNA-based marker for population genetic analysis.