• Korean Journal of Optics and Photonics
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• v.14 no.3
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• pp.298-305
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• 2003

We have calculated the single mode yield of index-coupled (IC) DFB lasers above threshold for several kL, and facet reflectivity combinations, and investigated the correlation between those results and the single mode yield as a function of f number at the threshold. As a result, there is little correlation between the single mode yield above threshold and the single mode yield as a function of f number at the threshold. The single mode yields above threshold for kL of 0.8 and 1.25 is larger than those for kL, of 2 and 3 due to the spatial hole burning effect. Also, we have investigated the effect of the reflectivity of the AR facet on the single mode yield for AR-HR and AR-CL combinations. For AR-HR combinations, the single mode yield increases as the reflectivity of the AR facet decreases. However, for AR-CL combinations, the reflectivity of the AR facet for the largest single mode yield exists. In the single mode yield calculations for IC DFB lasers in this paper, the single mode yield for kL of 0.8 with AR(1％)-HR combination is largest above threshold.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.4
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• pp.251-256
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• 1976

Langmuir adsorption maximum was used as a basis for the estimation of phosphate requirement as related to the application method to a newly reclaimed hilly land. The application rates of phosphate fertilizer were 4 levels corresponding to 5, 10, 20, and 30 percent of the Langmuir adsorption maximum which was determined by the laboratory experiment. The phosphate fertilizer was applied in two different methods of broadcast and band application. Yield of soybean on a newly reclaimed hilly land was greatly affected by the amount of phosphate fertilizer and application method. With the same amount of phosphate fertilizer, the soybean yield in the broadcast was always lower than that in the band application even though the yield in the broadcast increased with the application rate up to the highest level of this experiment. However, the yield in the band application showed steep increase up to 20 percent level and then the yield decreased at the highest level. The yield at the rate of 5 percent with the band application was equal to the yield at the rate of 20 percent with broadcast, and the yield at the rate of 10 percent with band application was higher by 17 percent than that in the highest broadcast rate. When manure was applied at the rate of 1000 kg/10a to the plot of the 10 percent band application, the yield was 14.6 percent higher than the yield of the plot of the 10 percent band application without the manure and was equivalent to the yield of the plot of the 20 percent band application.

• Korean Journal of Remote Sensing
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• v.37 no.2
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• pp.199-209
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• 2021

By removing the increasing trend that long-term time series average of rice yield due to technological advancement of rice variety and cultivation management, we tried to improve the rice yield estimation model which developed earlier using MODIS NDVI and meteorological data. A multiple linear regression analysis was carried out by using the NDVI derived from MYD13Q1 and weather data from 2002 to 2019. The model was improved by analyzing the increasing trend of rime-series rice yield and removing it. After detrending, the accuracy of the model was evaluated through the correlation analysis between the estimated rice yield and the yield statistics using the improved model. It was found that the rice yield predicted by the improved model from which the trend was removed showed good agreement with the annual change of yield statistics. Compared with the model before the trend removal, the correlation coefficient and the coefficient of determination were also higher. It was indicated that the trend removal method effectively corrects the rice yield estimation model.

• Korean Journal of Agricultural and Forest Meteorology
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• v.26 no.1
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• pp.75-88
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• 2024

It would be advantageous to predict acreage and yield of crops in major grain-exporting countries, which would improve decisions on policy making and grain trade in Korea. A climate suitability model can be used to assess crop acreage and yield in a region where the availability of observation data is limited for the use of process-based crop models. The objective of this study was to determine the climate suitability index of wheat by province in Ukraine, which would allow for the spatial assessment of acreage and yield for the given crop. In the present study, the official data of wheat acreage and yield were collected from the State Statistics Service of Ukraine. The EarthStat data, which is a data product derived from satellite data and official crop reports, were also gathered for the comparison with the map of climate suitability index. The Fuzzy Union model was used to create the climate suitability maps under the historical climate conditions for the period from 1970 to 2000. These maps were compared against actual acreage and yield by province. It was found that the EarthStat data for acreage and yield of wheat differed from the corresponding official data in several provinces. On the other hand, the climate suitability index obtained using the Fuzzy Union model explained the variation in acreage and yield at a reasonable degree. For example, the correlation coefficient between the climate suitability index and yield was 0.647. Our results suggested that the climate suitability index could be used to indicate the spatial distribution of acreage and yield within a region of interest.

• Journal of Korean Society of Steel Construction
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• v.16 no.3 s.70
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• pp.315-324
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• 2004

This study performs a yield line analysis of welded T-joints in cold-formed Square Hollow Sections (SHS) with the branch in axial compression. The existing yield line models proposed by Koto, Packer, Zhao, and CIDECT and the proposed yield line model of the previous study are compared, using the existing test results of welded T-joints in cold-formed SHS. The yield line model suggested in the previous paper, which is based on the simplified yield line analysis, is reviewed to evaluate its application limit on cold-formed SHS T-joints. In the proposed model, the round corner of the cold-formed SHS section and weld size are taken into account. Finally, the validity range of yield line analysis is determined by observing the actual failure modes and comparing the test value with the analysis value, set as ${\beta}^{\prime}{\leq}0.8$ where ${\beta}^{\prime}=0.8$, ${\beta}^{\prime}=b_1^{\prime}/b_0^{\prime}$, $b_1{^{\prime}}=b_1+t_0$ and $b_0{^{\prime}}=b_0-t_0$.

• Korean Journal of Medicinal Crop Science
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• v.13 no.5
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• pp.298-302
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• 2005

In order to decide the optimum planting time for Bupleurum falcatum L. which is grown widely in Korea, some experiments were carried out in different regions such as mid-north area (Gangwon-do, Gyeonggi-do and Chungcheongnamdo), mid-south area (Jeollanam-do, Jeollabuk-do, Gyeongsangnam-do and Gyeongsangbuk-do). The mid-south area had the highest total saikosaponin contents of 1.001, which is the medicinal ingredients of Bupleurum falcatum L., in accordance with the different Bupleurum falcatum L. regions. Also this area has the highest extract contents of 24.3%. Average dry root yields in mid-north area (Gangwon-do) were $450{\sim}460$ kg/ha at planting time of March 20th to March 30th, 500 kg/ha at the time of March 30th to April 10th, and $470{\sim}480$ kg/ha at the time of March 10th to March 20th in Chungcheongnam-do. The optimum planting time in the mid-south area (Jeollabuk-do) was March 10th to March 30th with the average dry root yield of $490{\sim}550$ kg/ha. Average dry root yield in Euiseong, Gyeongsangbuk-do area was 470 kg/ha, and the optimum planting time was April 10th, which suggested that the yield increased as the planting time was delayed. At Jeju-do, the volcanic soil of farsouthern area, average dry root yield was 510 kg/ha at the time of March 10th, but the yield from non-volcanic soil was lower than from volcanic soil, which had a dry root yield of 470 kg/ha.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.112-121
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• 2007

Grain filling is a crucial factor that determines grain yield in crops since it is the final process directly associated with crops' yield performance. Grain filling process can be characterized by the interaction of rate and duration of grain filling. This study was conducted, using 16 temperate japonica rice genotypes, with aims to (1) seek variations in grain filling duration and rate on area basis, (2) compare the contribution of grain filling duration and rate to grain yield, and (3) examine the influence of temperature and solar radiation for effective grain filling on grain yield in relation to grain filling duration and rate. Grain filling rate and duration exhibited highly significant variations in the ranges of $20.7{\sim}46.3\;g\;m^{-2}d^{-1}\;and\;11.2{\sim}35.5$ days, respectively, depending on rice genotypes. Grain yield on unit area basis was associated positively with grain filling duration but negatively with grain filling rate. Grain filling rate and duration were negatively correlated with each other. Final grain weight increased linearly with the rise in both cumulative mean temperature and cumulative solar radiation for effective grain filling. Higher cumulative mean temperature and cumulative solar radiation for effective grain filling were the results of longer grain filling duration, but not necessarily higher daily mean temperature and daily solar radiation for effective grain filling. Grain filling rate demonstrated an increasing tendency with the rise in daily mean temperature for effective grain filling but their relationship was not obviously clear. It was concluded that grain filling duration, which influenced cumulative mean temperature and cumulative solar radiation for effective grain filling, was the main factor that determined grain yield on unit area basis in temperate Japonica rice.

• The Plant Pathology Journal
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• v.18 no.2
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• pp.68-73
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• 2002

The influence of fungicidal spray was assessed on powdery mildew epidemics caused by Erysiphe polygoni D.C. and on yield-attributing characters of mungbean [Vigna radiata (L.) Wilczek]. Mildew attack adversely affected the yield-attributing characters of mungbean and exhibited negative significant correlation with pod length (-0.57), pods/plant (-0.74), pod weight (-0.68), 100 seeds weight (-0.69), 100 seeds swell weight (-0.59), and seed germination (-0.71). These characters had direct or indirect effects on grain yield, which was also adversely affected due to mildew attack (-0.89). Powdery mildew was significantly retarded due to the single spray of carbendazim (0.05%) at 30-day-old crop, where the apparent rate of infection (r) was minimum at 0.0095/ unit/day and with low (11.44%) powdery mildew intensity. Other fungicides like tridemorph (0.075%) and penconazole (0.05%) were equally effective against the mildew disease where the disease intensity was less than 20% and the values of r were 0.0134 and 0.039/unit/day respectively, as compared with the control at 0.267/unit/day. Fungicide spray influenced the yield-attributing characters besides controlling the disease. Such effects were more pronounced in carbendazim (0.05%)-treated plots due to its phytotonic nature where pod length (7.59cm), pods/plant (29.75), pod weight (8.16 g), 100 grain weight (3.94 g), and swell weight of 100 seed (9.49 g) were maximum resulting to the highest yield (480 kg/ha) as compared with that of control (224 kg/ha). Spray of carbendazim also improved seed germination (74.5%). Spray of other fungicides like carbendazim with copper oxychloride in 1:1 ratio, tridemorph (0.075%), and penconazole (0.05%) was equally effective against powdery mildew of mungbean. These fungicides also exhibited positive effects on yield-attributing characters of the crop and finally increased yield. These systemic fungicides were more effective in controlling powdery mildew disease of V. radiata in the rainy season compared with wettable sulphur.

• Journal of Intelligence and Information Systems
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• v.9 no.1
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• pp.157-177
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• 2003

This paper presents a comprehensive and successful application of data mining methodologies to improve and predict wafer yield in a semiconductor wafer fabrication system. As the wafer fabrication process is getting more complex and the volume of technological data gathered continues to be vast, it is difficult to analyze the cause of yield deterioration effectively by means of statistical or heuristic approaches. To begin with this paper applies a clustering method to automatically identify AUF (Area Uniform Failure) phenomenon from data instead of naked eye that bad chips occurs in a specific area of wafer. Next, sequential pattern analysis and classification methods are applied to and out machines and parameters that are cause of low yield, respectively. Furthermore, radial bases function method is used to predict yield of wafers that are in process. Finally, this paper demonstrates an information system, Y2R-PLUS (Yield Rapid Ramp-up, Prediction, analysis & Up Support), that is developed in order to analyze and predict wafer yield in a korea semiconductor manufacturer.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.2
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• pp.130-133
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• 2001

The purpose of this study was to investigate the decreased ratio of growth and yield by delayed seeding and flowering because drought of spring season often cause to delay seeding and sprout emergence. Equation of linear regression, y=-11.914x＋818.61 ($R^2$=0.916) and y=-16.96lx＋913.98 ($R^2$=-0.885) were derived from relationship between sowing date and yield of leading variety, Yangbaeckkae in 1999 and 2000, respectively. Yield was decreased by 7, 24, 40, 57, 74%, respectively, according as sowing date was delayed more 5, 15, 26, 36, 46 days than May 15, standard sowing date under the culture mulched with black P.E. film. Number of capsules per plant and length of stem bearing capsule were greatly decreased, while plant height, stem diameter, and day to flowering were affected little by delayed seeding date. Equation of linear regression, y=-0.7081x＋41.04 ($R^2$=0.861) was derived from relationship between flowering date and yield of 33 accessions. Yield was decreased by 7.7, 8.3, 9.2, 10.1, 11.2%, respectively, according as flowering date was delayed more 1, 2, 3, 4, 5 days than July 3, normal flowering date of Yangbaeckkae when it was sown on May 15, and the more flowering date was delayed, the more yield was decreased. Number of capsules per plant and length of stem bearing capsules were greatly decreased, but plant height and harvest index were decreased little by delay of flowering date