• 한국수산과학회지
• /
• 제23권6호
• /
• pp.475-483
• /
• 1990

An assessment of Kuwait's commercial fish stocks: hamoor (Epinephelus tauvina), zobaidy (Pampus argenteus), nakroor (Pomadasys argenteus) and sheiry (Lethrinus nebulosus), was conducted using length-frequency data, mean growth and mortality estimates obtained during 1981$\~$1988. The length-cohort analysis indicated that increases in fishing effort would not lead to long-term gains in yield of the stocks at the current estimate of natural mortality rate (M). At high M which was assumed arbitrarily, some benefit in yield could be obtained, especially for hamoor and sheiry. At low M, the yield of all stocks decreased with increased fishing effort. Increases in fishing effort resulted in significant dec-line in spawning stock size for all the stocks. Yield-per-recruit analysis indicated that, un-der low M assumption, a higher yield can be obtained for zobaidy and nakroor by reducing fishing effort. At moderate M, decreases in fishing effort brought gains in yield per recruit of the stocks, but it was not substantial compared with the present level of M. At high M, most of the stocks reached the maximum yield-per-recruit. Overall, increased fishing effort either will not be associated with large long-term gains in yield or, in some stocks, might cause a decline from the present level.

• 한국유기농업학회지
• /
• 제24권3호
• /
• pp.369-383
• /
• 2016

Crop yield insurance program in Korea has rapidly grown not only in quantity but in quality for 15 years since it was introduced in 2001. Despite growth of Crop insurance, performance evaluation for crop yield insurance has not fully been evaluated at the farm, consumer and national level. The purpose of this study is to conduct the performance evaluation for crop yield insurance through estimating the effects of farm revenue stabilization and social welfare increase with three popular insurance items: apple, pear and sweet persimmon. Based on the analysis of social welfare effect, cost-benefit analysis of operating crop yield insurance was conducted at the national level. We found that crop yield insurance stabilizes farm revenue based on the estimated four risk indicators: Coefficient of Variation, Value at Risk, Certainty Equivalence, and Risk Premium. The result of cost-benefit analysis shows that crop yield insurance increases social net benefit by 44.1 billion won for the three items. As a result, crop yield insurance program has contributed remarkably on social welfare as well as farm management and its role will be more important in the future.

• 한국작물학회지
• /
• 제52권2호
• /
• pp.134-139
• /
• 2007

The research was conducted with the aim of determining effects of seedling age on the yield of four fine rice varieties viz., Kalizura, Tulshimala, BRRI (Bang-ladesh Rice Research Institute)-37 and BRRI-38. The seedling of different ages such as 15, 25, 35 and 45 days were transplanted on the same day maintaining $25cm{\times}15cm$ spacing. The experiment was laid out in a randomized complete block design with three replications. The yield and yield contributing characters were influenced by seedling age, variety and their interaction. BRRI-38 gave the highest number of effective tillers $hill^{-1}$, panicle length, total spikelets $panicle^{-1}$, grains $panicle^{-1}$, 1000-grains weight and grain yield. Likewise, yield and yield contributing characters were the highest in 35 days old seedling. On the other hand, the variety (BRRI-38) with the same age as of seedlings 35 days old seedlings was found superior to other interactions, but, in the production of grains $panicle^{-1}$ and 1000-grains weight there was no significant effect in this interaction. From the findings it may be inferred that BRRI-38 with 35 days old seedlings produced the highest grain yield.

• 한국식품과학회지
• /
• 제22권2호
• /
• pp.199-205
• /
• 1990

우리나라 쌀의 품종별 도정 및 품위특성을 조사하여 합리적인 시장성을 평가할 수 있는 방법을 모색하고자 일반계 쌀과 다수계 쌀의 품종별로 품위 및 도정특성을 조사 분석한 결과는 다음과 같다. 유형별 도정률은 일반계가 높고 쇄미율은 통일계가 높았으나 미강률은 큰 차이가 없었으며 벼에서 쌀까지의 도정률은 현미의 용적중, 제현율 및 현백률이 높은 품종이 요구되고 현미의 쇄립률, 심복백립률, 왕겨율, 쇄미율 및 미강률이 낮은 품종은 쌀의 품위 및 수율이 향상되었다.

• Korea-Australia Rheology Journal
• /
• 제18권1호
• /
• pp.15-24
• /
• 2006

The first international inter-laboratory study, involving six laboratories, has been conducted to examine issues associated with yield stress measurements in suspensions. The initial focus of the project was to evaluate the reliability and reproducibility of several common yield stress measuring techniques employed in different laboratories and with different instruments. Aqueous suspensions of colloidal $TiO_2$ at concentrations of 40-70 wt% solids were used as the test fluids. A wide range of instruments and techniques employing both direct and indirect methods were used to determine the yield stress of the samples prepared according to a prescribed procedure. The results obtained indicated that although variations of results existed among different techniques, direct yield stress measurements using static methods produced more reliable and repeatable results than other methods. Variability of the yield stress measured using different techniques within any laboratory however was less significant than variability of the results among different laboratories. The nature and condition of the test suspensions was identified as the most likely factor responsible for the poor reproducibility of yield stress measurements from different laboratories.

• 한국축산식품학회지
• /
• 제25권3호
• /
• pp.328-332
• /
• 2005

The effect of k-casein (k-CN) variant on milk production traits (milk yield, fat yield, protein yield, fat percentage and protein percentage) was estimated for 568 Holstein cows in the first lactation. The k-CN valiant were determined by PCR-RFLP (restriction fragment length polymorphism) technique at the DNA level. Single trait linear model was used for the statistical analysis of the data. Result of this study indicated that k-CN variant affected significantly milk yield (P<0.05) and protein yield (P<0.01). Animals with the BB variant produced 622kg milk more and had protein yield higher by 32kg compared with animals with the AA variant No associations between the k-CN variants and other milk production trait were found. Therefore, milk and protein yield may be improved through milk protein typing by increasing the frequencies of k-CN B variant in dairy cattle population. In cheese making, it will be also preferable to have milk with the B variant of k-CN, which gives higher yield having a better quality than the A variant milk.

• 한국초지조사료학회지
• /
• 제33권3호
• /
• pp.185-192
• /
• 2013

This study was carried out to investigate the influence of the seeding dates on the yield and feed value in cultivating Italian rye grass on paddy soil. The field experiment was designed in a randomized block design of 3 repetitions with seeding dates of Oct. 19 (T1), Oct. 26 (T2), Nov. 2 (T3), Nov. 9 (T4), and Nov. 16 (T5) treatments. Plant length, fresh yield, dry matter yield and TDN yield were increased with early seeding dates (p<0.05). Crude protein, Crude fat and crude ash were increased with early seeding dates (p<0.05). On the other hand, NDF, ADF and Crude fiber were decreased with early seeding dates (p<0.05). Total mineral contents were higher in the order of T4 > T3 > T5 > T1 > T2 (p<0.05). The total composition amino acid content was decreased significantly (p<0.05) as the seeding dates delayed. Total free sugar content was highest in T1, whereas the lowest in T5 treatment (p<0.05). Nutrition yields (crude protein, crude fat, amino acid and free sugar) were increased significantly with early seeding dates (p<0.05). The above result indicated that it is favorable to seed soon after rice harvest to increase dry matter yield and nutrition yield of Italian ryegrass in the midlands.

• Plant Resources
• /
• 제6권3호
• /
• pp.178-182
• /
• 2003

This study was conducted to investigate the relationship between yearly variations of climatic elements and yearly variations of productivity in perilla. In addition, correlation coefficients among yield and yield components were estimated. The data of yield and yield components were investigated for 10 years from 1991 to 2000. The meteorological data gathered at the Yeosu Weather Station for the same period were used to find out the relationships between climatic elements and productivity. Yearly variation of the amount of precipitation in September was large with coefficients of variation(c. v.) of 11.1%, but the coefficient of variance(c. v.) in July and August were relative small with 1.8, 2.1%, respectively. Number of cluster per hill and weight of 1,000 grains were greatly with c. v. of 76.1, 79.3%, respectively, but the coefficients of variance(c. v.) of plant height and seed yield were more less with 9.58, 10.60%, respectively. Correlation coefficients between precipitation of September and seed yield were positively significant correlation at the level of 5.1%, respectively, but the duration of sunshine in September and seed yield were negatively significant at the level of 5.1%, respectively. Correlation coefficients of these, the plant height, number of branches per plant, cluster length, number of cluster per hill, weight of 1,000 grains and seed yield were positively significant at the level of 5.1% respectively.

• Journal of Magnetics
• /
• 제22권2호
• /
• pp.281-285
• /
• 2017

To suppress the wall slip effect and improve the yield stress measurement precision of magnetorheological fluid, measurement disks with different grooves are first manufactured. Then, the influence of groove characteristics on the yield stress of magnetorheological fluid is investigated by the method of experiments. Finally, the optimization wall grooves of measurement disks are obtained, and the yield stress of a self-prepared magnetorheological fluid is measured. Results indicate that the groove type and groove width have a slight influence on the shear yield stress, whereas the measured yield stress increases with enhanced groove density, and the optimized groove depth is 0.3 mm. The measured shear yield stress of self-prepared MR fluid can be improved by 18 % according to the optimized grooved disks, and the maximum yield stress can reach up to 65 kPa as the magnetic flux density is 0.5 T.

• Plant Resources
• /
• 제7권3호
• /
• pp.206-210
• /
• 2004

In order to find out the optimum harvest (dipping) date combined with sowing date on yield and nutrient quality of forage rye which is suitable at the Southern part of Korea, Paldanghomil variety was grown Sep. 2001 to May 2002 at Sunchon National University, and yield and nutrient quality of plant were observed. As harvest date and sowing date were delayed, the plant length was longest, number of leaves per plant was increased in the time of May 20 clipping. Fresh yield was the heaviest in the time of May 20 clipping and Oct. l0 sowing, and the most dry matter yield was the heaviest in the time of May 20 clipping and Oct. 10 sowing. Content of crude protein was the highest and that of crude fiber such as NDF, ADF, hemicellulose, cellulose and lignin were the lowest in the late time of clipping and sowing. Further more IVDMD was high and dry matter yield and digestible dry matter yield were the highest in the time of May 20 dipping and Oct. 10 sowing. Judging from the results reported above, at optimum harvest (dipping) date combined with sowing date for yield and nutrient quality of forage rye seemed to be the time of May 20 clipping and Oct. 10 sowing.