• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.830-835
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• 2011

Total soil microbial activities have great impact to soil management for organic farming. This study was evaluated in the soil microbial community by fatty acid methyl ester (FAME) in a controlled horticultural field for strawberry organic farm. Experimental plots were prepared with a high level of soil electrical conductivity (EC) and a optimum level of soil EC. Soil microbial biomasses and communities of total bacteria, Gram-negative bacteria, Gram-positive bacteria, actinomycetes, fungi, and arbuscular mycorrhizal fungi in the high level of soil EC were significantly larger than those in the optimum level of soil EC. Lower ratios of cy17:0 to 16:$1{\omega}7c$ and cy19:0 to 18:$1{\omega}7c$ were found in the optimum level of soil EC than those in the high level of soil EC, indicating that microbial stress decreased.

• Journal of Aquaculture
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• v.6 no.1
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• pp.47-53
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• 1993

Feeding trials were conducted for a test of the optimum dietary protein levels for the fingerling Korean catfish, Parasilurus asotus. The growth response was examined in terms of weight gain, feed coefficient. protein efficiency ratio and net protein utilization for 8 weeks at $23\~27^{\circ}C$. Within a range of 25 to 55\%$ crude protein levels in the diet, the body weight increased while the dietary protein level increased. Accumulation of protein in the body reached the maximum when the crude protein level in the diet was at $45\%$. These results indicate that the optimum dietary protein level of fingerling Korean catfish was about $45\%$ when anchovy meal was used as the protein source.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.6 no.8
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• pp.63-71
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• 1983

Aggregate planning coordinate the control variable over long-term to apply a demand variable and forcasting. In order to necessary the goal that doesn't make an inter-contradiction and explicitly defined. We made a considerable point of system approach for scheduling establishment. It include the control variables of aggregate planning : 1) employment 2) over time working and idle time 3) inventory 4) delivery delay S) subcontract 61 long - term facility capacity. Each variables composed of pure strategy as like a decision of inventory level, a change of employment level, etc. md alternative costs make a computation on the economic foundation. But the optimum alternative costs represent the mixed pure strategy. The faults of this method doesn't optimum guarantee a special scheduling as well as increasing a number of alternative combination. Theoretical, Linear Decision Rule make an including all variables, but it is almost impossible for this model to develope actually And also make use of the aggregate planning problem for developing system approach : LDR, heuristic model, Search Decision Rule, all kind of computers, simulation. But these models are very complex, each variables get an extremely inter-dependence. So this study be remained by theory level, some approach methods has not been brought the optimum solution to apply in every cases.

• Plant Resources
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• v.6 no.2
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• pp.102-107
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• 2003

To find out the optimum fertilizer level for high yielding variety, Velox, experiment was conducted with 15 compositions of fertilizer levels at the experiment field of forage crop in Sunchon National University from Mar. 2000 to Aug. 2000. The effects of nitrogen fertilizer on plant growth were significant but increasing rate of application in potassium and phosphate fertilizers above 6 kg/a had negligible effects on plant growth. The optimum nitrogen application level of fertilizers turned out to be 16-6-6 kg/l0a of N-P$_2$O$_{5}$-K$_{5}$O. Content of crude protein was highest and that of crude fiber such as NDF, ADF, cellulose and lignin were lowest at this rate of fertilizer application. Furthermore, IVDMD was high and dry matter yield were highest at the optimum raterate

• Journal of Korean Society of Industrial and Systems Engineering
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• v.11 no.18
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• pp.71-80
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• 1988

Process capability implies the qualitative capability of a process, and it is necessary to specify the process capability by quantification and to evaluate the level with the specified standardizaion. But the process capability index is currently used to evaluate the performance of quality control activity. without considering the characteristics of process structure or the economy of management. Here the researcher would like to redefine process capability and emphasize its index may be used as the measure of managerial assessment and the objective of process quality control in full consideration of the economic aspects of process characteristics. Too little or too much process capability causes a loss of or excess. The proper economic level of process capability varies to each process. The procedure of taking the optimum process capability index is derived from the expected profit function, whereas each method is studied in cases of normal process with one-sided specification and two-sided specification. In addition, the process capability index is presented as a method of quality assurance. And an example is exhibited on wrapping process of 'A' company. The results of this study are summarized at follows. First, though the norminalization of the process capability index is possible by the existing methods, the optimum process capability index can vary to the situation of each process. So, the optimum process capability index which is suggested in this dissertation should be used as the standard to assess process capability. Second, the process capability index can take its effect not just in indicating quality control or managerial records but also in the management of high qualify assurance.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.103-104
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• 2008

This paper proposes an alternative methodology for deciding an optimum deterministic reliability level (IRR; Installed Reserve Rate) by using probabilistic reliability criterion (LOLE; Loss of Load Expectation). Additionally, case studies using the proposed method induce the characteristics of relationship between the probabilistic reliability index (LOLE) and deterministic reliability index (IRR) for 2008 year in Korea power system. The case study presents a possibility that an optimum IRR level in Korea can be assessed using the proposed method. Korea power system has been using the LOLE criterion to determine the adequacy of installed capacity (ICAP) requirement. The criterion in Korea is that the loss of load expectation shall not exceed the available capacity more than five day in ten years (=0.5[days/year]). The probabilistic reliability evaluation and production cost simulation program which is called PRASim is used in order to evaluate the relationship and optimum IRR in this paper.

• Korea journal of population studies
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• v.29 no.1
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• pp.241-268
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• 2006

This study aim to examine the optimum population in Korea, which has the lowest fertility rate in the world. This study has significance because this rapid decline in the fertility rate is expected to bring the decrease of the population and unbalance in the population composition in Korea. From the social welfare perspective, the optimum population is guided by maximization of the social welfare level per person or the social welfare level in a society. The optimum population can be defined as follows: The proportion of older adults 65 and over is 15-17%, the proportion of work force is 64-69%, the index of aging is 72-104. Within the current population and population composition, the optimum population is estimated as 4.85-4.95 million. These findings imply that we need to remove causes of low fertility rate and prepare for policies encouraging immigration of labor force from foreign countries. In addition, policies and programs where children can be grown up in good environments and women and older adults can participate in labor force should be established.

• Journal of the Korea Society of Computer and Information
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• v.22 no.9
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• pp.41-47
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• 2017

In this paper, we consider the case where D2D users and the cellular user share the uplink of the cellular system. We propose an iterative power control algorithm that converges to the optimum power value. Each user iteratively updates its transmit power level according to the interference function. Finally, all D2D users and cellular user that participate in the transmission get the optimum transmit power level. We first investigate the interference structure and define the interference function. Then, we show that the considered interference function belongs to the standard interference function that converges the unique transmit power level. Through numerical examples, the convergence of the proposed power control algorithm is examined in the various transmission scenarios.

• Journal of the Korea Concrete Institute
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• v.15 no.2
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• pp.352-359
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• 2003

Portland cement concrete (PCC) pavements are more durable and have superior surface friction compared to most dense-graded asphalt. However, data collected to date generally show PCC pavements to create more noise than asphaltic surfaces. Recent research has shown that some of the new concrete pavement textures are worthy of further examination. One of these, exposed aggregate surfaces, appear to provide better noise quality characteristics as well as good frictional characteristics and durability. In this paper, we considered the relationship between noise level and various textures of exposed aggregate concrete (EAC) pavement by tire impact noise measurement. As the results of that, it was suggested that optimum surface texture and manufacturing condition of EAC in order to reduce tire and pavement interaction noise. Conclusively, we would like to recommend optimum condition of EAC pavement at the respects of materials and treatment. Furthermore, Frequency spectrum as well as A-weighted noise level was also evaluated to analyze properties of noise between PCC and EAC.

• Journal of Korean Society for Quality Management
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• v.30 no.2
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• pp.86-98
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• 2002

Defining the relationship between the quality of injection molded parts and the process condition is very complicate because of lots of factor are involved and each factor has a non-linearity. With the development of CAE(Computer Aided Engineering) technology, the estimation of volumetric shrinkage of injection mold parts is possible by computer simulation even though restricted application. In this research, Neural Network applied for finding optimal processing condition. The percent of volumetric shrinkage compared on each case and show neural network can be successfully applied selecting optimum condition not only within factor level but also between factor level.