• Korean Journal of Soil Science and Fertilizer
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• v.37 no.2
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• pp.74-82
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• 2004

This study was conducted to estimate the optimum application rate of fertilizer N based on $NO_3-N$ concentration in soils for tomato (Lycopersicon esculentum Mill.) cultivation in plastic film house. Tomato plants were cultivated with and without fertilizer in twelve soils which have different concentrations of $NO_3-N$ ranging from 46 to $344mg\;kg^{-1}$. Dry weight (DW) of above-ground part of tomato with no fertilizer ranged from 28.9 to $112.5g\;plant^{-1}$, depending on N-supplying capability of soils. The soil $NO_3-N$ was positively correlated with DW ($r=0.83^{**}$) and N uptake ($r=0.78^{**}$) by tomatoes in no fertilizer treatment, and negatively correlated with fertilizer effciencies resulted from the differences of DW and N uptake between fertilized and non-fertilized plot. The relationships between soil $NO_3-N$ concentration and DW, N uptake, and fertilizer efficiency were analyzed to determine the critical levels of soil $NO_3-N$ for tomato cultivation. The limit critical levels of soil $NO_3-N$ were estimated to be more than $280mg\;kg^{-1}$ for no application of fertilizer N and to be less than $50mg\;kg^{-1}$ for recommended application of fertilizer N. These critical levels of soil $NO_3-N$ were nearly the same as those calculated from regression equation between electrical conductivity(EC) and soil nitrate for critical levels of EC in recommendation equation of fertilizer N for tomato under the plastic film house by NationaI Institute of Agricultural Science and Technology. Consequently, the optimal application rate of ferdilizer N for tomato cultivation in the soils containing $NO_3-N$ concentration between $280mg\;kg^{-1}$ and $50mg\;kg^{-1}$ was estimated by the equation Y = -0.4348X＋121.74, where Y is the percent(%) to the recommended application rate of N fertilizer and X is the soil $NO_3-N$ concentration ($mg\;kg^{-1}$).

• Journal of applied mathematics & informatics
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• v.12 no.1_2
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• pp.395-408
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• 2003

Common Channel Signaling(CCS) networks need special controls to avoid overload of signaling networks and degradation of call process-ing rate, since they play an important role of controlling communication transfer networks. Congestion control and flow control mechanisms are well described in ITU-T recommendation on Signaling System No.7(SS7). For the practical provisions, however, we need an analysis on the relation among service objects, system requirements and implementation of congestion control algorithms. SS7 provides several options for controlling link congestion in CCS networks. In this paper we give a general queueing model of congestion control algorithm which covers both the international and national options. From the queuing model, we obtain the performance parameters such as throughput, message loss rate and mean delay for the international option. To show the performance of the algorithm, some numerical results are also given.

• Journal of KIISE
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• v.42 no.11
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• pp.1380-1385
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• 2015

Collaborative filtering is one of the most successfully used methods for recommender systems and has been utilized in various areas such as books and music. The key point of this method is selecting the most proper recommenders, for which various similarity measures have been studied. To improve recommendation performance, this study analyzes problems of existing recommender selection methods based on similarity and presents a method of dynamically determining recommenders based on the rate of co-rated items as well as similarity. Examination of performance with varying thresholds through experiments revealed that the proposed method yielded greatly improved results in both prediction and recommendation qualities, and that in particular, this method showed performance improvements with only a few recommenders satisfying the given thresholds.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.2
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• pp.105-111
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• 2002

To find out the optimum nitrogen fertilization levels for the leafy vegetables in volcanic ash soils of Cheju island, fertilization effects on chinese cabbage chinese and cabbage were investigated through pot and field experiments. In pot experiment conducted with two volcanic ash soils of Cheju island, optimum rates of nitrogen fertilizer was ranged from 294 to $331kg\;ha^{-1}$ for chinese cabbage. At field experiment with one volcanic soil, the optimum N fertilizer was $331kg\;ha^{-1}$. On the basis of soil organic matters, fertilizer recommendation formula for cabbage, could be established by using 1.03 of comparison factors (F) compared with chinese cabbage : y=344.54-0.285x for chines cabbage, y= 354.88-0.294x for cabbage, where y is the recommendation amount of nitrogen fertilizer with x g $kg^{-1}$ of organic matter in soil. Actual optimum rate of nitrogen fertilizer for chinese cabbage under field condition was much more similar to the value caluculated by the revised nitrogen recommendation formula than the amount of nitrogen fertilizer recommended by the current formula in volcanic ash soil.

• Nutrition Research and Practice
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• v.14 no.6
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• pp.654-666
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• 2020

BACKGROUND/OBJECTIVES: This study aimed to evaluate how breastfeeding and complementary nutrition practices of mothers of 0-24-month-old children comply with the World Health Organization (WHO) recommendations for infant and young child feeding and to compare the results with selected demographic parameters related to the mother and child. SUBJECTS/METHODS: The research sample comprised mothers (n = 250) with children less than 2 years old. Data were obtained via questionnaire and were analyzed using SPSS 20.0 package program. The Pearson χ² or Fisher's exact tests were used for assessing relationships between categorical variables. The one-sample t-test was used for comparisons with reference values. RESULTS: Most mothers (97.2%) breastfed their babies immediately after birth. The mean time to breastfeeding after delivery was 47.8 ± 14.8 minutes, and 40.8% of the mothers complied with the WHO recommendation. Furthermore, 59.8% of the mothers exclusively breastfed their children for 6 months (mean 5.2 ± 1.5 months). The mean duration to the start of providing complementary food was 5.8 ± 0.6 months, and 76.1% of mothers who complied with the WHO recommendation. Only 12.3% of mothers breastfed their children for at least 12 months (mean 7.7 ± 3.3 months). On average, mothers gave cow milk to their children for the first time at 10.1 ± 1.7 months and honey at 11.8 ± 2.3 months. The mothers' rates of compliance with the WHO recommendations on cow milk and honey feeding were 32.0% and 71.6%, respectively. The rate of mothers who complied with the WHO minimum meal frequency recommendation was 88.3%. CONCLUSIONS: We suggest that the WHO recommendations on this subject will be realized more fully by emphasizing the importance of the positive effects of breastfeeding until the age of 2 years and of a timely start of complementary food provision. Such changes will affect child health over the long term.

• Journal of information and communication convergence engineering
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• v.22 no.1
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• pp.44-55
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• 2024

High-utility itemset mining (HUIM) is a dominant technology that enables enterprises to make real-time decisions, including supply chain management, customer segmentation, and business analytics. However, classical support value-driven Apriori solutions are confined and unable to meet real-time enterprise demands, especially for large amounts of input data. This study introduces a groundbreaking model for top-N high utility itemset mining in real-time enterprise applications. Unlike traditional Apriori-based solutions, the proposed convolutional sequential embedding metrics-driven cosine-similarity-based multilayer perception learning model leverages global and contextual features, including semantic attributes, for enhanced top-N recommendations over sequential transactions. The MATLAB-based simulations of the model on diverse datasets, demonstrated an impressive precision (0.5632), mean absolute error (MAE) (0.7610), hit rate (HR)@K (0.5720), and normalized discounted cumulative gain (NDCG)@K (0.4268). The average MAE across different datasets and latent dimensions was 0.608. Additionally, the model achieved remarkable cumulative accuracy and precision of 97.94% and 97.04% in performance, respectively, surpassing existing state-of-the-art models. This affirms the robustness and effectiveness of the proposed model in real-time enterprise scenarios.

• Korean Journal of Environmental Agriculture
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• v.37 no.1
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• pp.28-33
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• 2018

BACKGROUND: In this study, we evaluated the effects of soil incorporation of hairy vetch (HV) or ryeas a green manure on the growth and yields of watermelon and soil nitrate nitrogen in a green house.. METHODS AND RESULTS: HV and rye were cultivated for 151 days after sowing on October 30th and incorporated into soil before transplanting watermelon. The amount of N added by soil incorporation of HV and rye were 79 kg/ha and 88 kg/ha, respectively. Five different N treatments for each of HV and rye were included as follows: green manure, green manure with urea at 25%, 50%or 75%, and 100% ureafor the N recommendation rate. The growth and fruit yield of watermelon were not different among the treatments of both HV and rye. Soil nitrate N content at both HV and rye treatments decreased continuously with the lapse of days after planting (DAP) and was lowest at 75 DAP: 44 mg/kg and 52 mg/kg the for the HV and rye treatment without urea, respectively. CONCLUSION: These results indicate that the N mineralized from the soil incorporated HV or rye accounts for an important portion of N available for the growth and fruit yield of watermelon. It can be suggested that the green manures, comparable to ureacould ensure the yield of watermelon, if soil nitrate N content isabove 40 mg/kg by soil incorporation of HV and rye during watermelon cultivation. However, further studies on the relationship between soil nitrate N content during cultivation periods and the fruit yield of watermelon are required.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.6
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• pp.384-392
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• 2000

To establish N fertilizer recommended scheme for the Chinese cabbage cultivation in green house based on the soil test of nitrate nitrogen, relationship among the content of soil nitrate and fertilizer effects and fertilizer N use efficiency were investigated from nine soils which differed amount of nitrate nitrogen from $14mg\;kg^{-1}$ to$226mg\;kg^{-1}$. The amount of nitrate nitrogen in soil showed a positive correlation with the dry weight of chinese cabbage in the plot of no fertilization. When the fertilizer effects were calculated by difference between the plots of fertilization and no fertilization in the dry weight and the amount of N uptake, a negative correlation was obtained between the amount of nitrate nitrogen in soils and the fertilizer effects. There was also a negative correlation between the amount of nitrate nitrogen in soils and fertilizer use efficiency. Recommendation of application rate of nitrogen fertilizer based on content of $NO_3-N$ in soils was evaluated by the regression equation among the content of soil nitrate, fertilizer effects and fertilizer N use efficiency. Incase the content of $NO_3-N$ nitrogen in soil is more than $200mg\;kg^{-1}$, No N fertilization is recommended; However, The standard N fertilization($320kg\;ha^{-1}$) is recommended for the soils with less than $50mg\;kg^{-1}$. For the soils ranged from $50mg\;kg^{-1}$ to $200mg\;kg^{-1}$ in the amount of nitrate nitrogen, an equation has been developed in order to calculate the recommended amount of fertilizer N.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.598-607
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• 2016

This study was conducted to evaluate the amount of nitrogen (N) top dressing based on the normalized difference vegetation indices (NDVI) by ground based sensors for leaf perilla under the polyethylene house. Experimental design was the randomized complete block design for five N fertilization levels and conventional fertilization with 3 and 4 replications in Gumsan-gun and Milyang-si field, respectively. Dry weight (DW), concentration of N, and amount of N uptake by leaf perilla as well as NDVIs from sensors were measured monthly. Difference of growth characteristics among treatments in Gumsan field was wider than Milyang. SPAD-502 chlorophyll meter reading explained 43.4% of the variability in N content of leaves in Gumsan field at $150^{th}$ day after seedling (DAS) and 45.9% in Milyang at $239^{th}$ DAS. Indexes of red sensor (RNDVI) and amber sensor (ANDVI) at $172^{th}$ day after seedling (DAS) in Gumsan explained 50% and 57% of the variability in N content of leaves. RNDVI and ANDVI at $31^{th}$ DAS in Milyang explained 60% and 65% of the variability in DW of leaves. Based on the relationship between ANDVI and N application rate, ANDVI at $172^{th}$ DAS in Gumsan explained 57% of the variability in N application rate but non significant relationship in Milyang field. Average sufficiency index (SI) calculated from ratio of each measurement index per maximum index of ANDVI at $172^{th}$ DAS in Gumsan explained 73% of the variability in N application rate. Although the relationship between NDVIs and growth characteristics was various upon growing season, SI by NDVIs of ground based remote sensors at top dressing season was thought to be useful index for recommendation of N top dressing rate of leaf perilla.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.1
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• pp.55-63
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• 2001

N fertilizer recommendations to optimize with consideration to maximum crop yields, maximum profits, and minimum N losses to ground or runoff water, an advisory system. Nitrogen Expert System (NES), was developed. The system was to estimate the optimal rate of N fertilizer application cornfields in Illinois. NES was constructed using Smart Elements, a knowledge-based system that manages the expertise of human experts. NES was reinforced by addition of the effect of a productivity index (PI), soil organic matter content (SOM), and pre-sidedressing of nitrate concentration (PSNT) to the optimal N fertilizer recommendation. NES contains 49 rules, 1 class, 14 objects, and 2 properties. NES was successfully operated, showing N recommendations with inputs of three soil properties including PI, SOM, and PSNT. NES can reduce N loss to the environment, but adherence to the recommendations may also reduce farmers income. Therefore, NES will be more effective by evaluating both environmental damage assessment and other economic agricultural management parameters and other soil physico-chemical parameters.