• Korean Journal of Agricultural Science
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• v.4 no.2
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• pp.173-177
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• 1977

These experiments were conducted to investigate the formation of organic acid and ethanol during fermentation by three yeast strains. One of these was industrial strain (No.7) from Japan, and the others were wild types (No. 47, No. 239) isolated from Takju-mash and Strawbery, respectively. Conditions of fermentation were varied by differing the supply of oxygen (air), and by using different fermentation media The results obtained were as follows: 1) All the yeast strains produced higher amount of total organic acid and ethanol under the conditions which were aerobic, i.e. the flasks were opened during fermentation, than in case of using the flasks with fermentation bung. 2) Organic acid and ethanol were produced rapidly in the mash medium than in the semi-synthetic medium, i.e. total amount of organic acid and ethanol was maximized in a short time in the mash medium. 3) On the mash medium, the highest amount of organic acid was obtained by the strain No. 239, the next by No. 7 and the lowest by No. 47. Ethanol was produced on this medium with decreacing order of No. 47, No. 239, and No. 7. 4) The strain No. 239 was proved to be a powerful organic acid producer, yielding higher amount of organic acid especially under the aerobic conditions. 5) Above results suggests that the strain No. 239 could be of useful in alcoholic drink industry, due to its powerful ethanol-producing characteristic accompaning with high yielding of organic acids.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.421-432
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• 2020

This paper proposes a 2-kW solid-state power amplifier (SSPA) developed by employing power amplifier pallets designed using gallium-nitride high electron mobility transistors, which is used in S-band military radars and to replace existing traveling-wave tube amplifier (TWTA). The SSPA consists of a high-power amplifier module, which combines eight power amplifier pallets, a drive amplifier module, a digital control module, and a power supply unit. First, the amplifier module and component were integrated into a small package to account for space limitations; next, an on-board harmonic filter was fabricated to reject spurious components; and finally, an auto gain control system was designed for various duty ratios because recent military radar systems are all active phase radars using the pulse operation mode. The developed SSPA exhibited a max gain of 48 dB and an output power ranging between 63-63.6 dBm at a frequency band of 3.1 to 3.5 GHz. The auto gain control function showed that the output power is regulated around 63 dBm despite the fluctuation of the input power from 15-20 dBm. Finally, reliability of the developed system was verified through a temperature environment test for nine hours at high (55 ℃) / low (-40℃) temperature profile in accordance with military standard 810. The developed SSPA show better performance such as light weight, high output, high gain, various safety function, low repair cost and short repair time than existing TWTA.

• Korean Journal of Construction Engineering and Management
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• v.16 no.5
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• pp.54-64
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• 2015

The modular construction has several advantages such as high quality of product, safe work condition and short construction duration. The manufacturing planning of modular construction should consider time frame of manufacturing, transport and erection process with limited resources (e.g., modular units, transporter and workers). The manufacturing planning of multi modular construction project manages the modular construction's characteristics and diversity of projects, as a type of modular unit, modular unit quantities, and date for delivery. However, current modular manufacturing planning techniques are weak in dealing with resource interactions and each project requirement in multi modular construction project environments. Inefficient allocation of resources during multi modular construction project may cause delays and cost overruns to construction operation. In this circumstance, this research suggest a manufacturing planning model for schedule optimization of multi project of modular construction, using genetic algorithm as one of the powerful method for schedule optimization with multiple constrained resources. Comparing to the result of the existed schedule of case study, setting optimized scheduling for multi project decrease the total factory producing schedule. By using proposed optimization tool, efficient allocation of resource and saving project time is expected.

• KDI Journal of Economic Policy
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• v.12 no.4
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• pp.3-20
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• 1990

The multisector model is designed to analyze and forecast structural change in industrial output, employment, capital and relative price as well as macroeconomic change in aggregate income, interest rate, etc. This model has 25 industrial sectors, containing about 1,300 equations. Therefore, this model is characterized by detailed structural disaggregation at the sectoral level. Individual industries are based on many of the economic relationships in the model. This is what distinguishes a multisector model from a macroeconomic model. Each industry is a behavioral agent in the model for industrial investment, employment, prices, wages, and intermediate demand. The strength of the model lies in the simulating the interactions between different industries. The result of its simulation will be introduced in the next paper. In this paper, we only introduce the structure of the multisector model and the coefficients of the equations. The multisector model is a dynamic model-that is, it solves year by year into the future using its own solutions for earlier years. The development of a dynamic, year-by-year solution allows us to combine the change in structure with a consideration of the dynamic adjustment required. These dynamics have obvious advantages in the use of the multisector model for industrial planning. The multisector model is a medium-term and long-term model. Whereas a short-term model can taken the labor supply and capital stock as given, a long-term model must acknowledge that these are determined endogenously. Changes in the medium-term can be analyzed in the context of long-term structural changes. The structure of this model can be summarized as follow. The difference in domestic and world prices affects industrial structure and the pattern of international trade; domestic output and factor price affect factor demand; factor demand and factor price affect industrial income; industrial income and relative price affect industrial consumption. Technical progress, as measured in terms of total factor productivity and relative price affect input-output coefficients; input-output coefficients and relative price determine the industrial input cost; input cost and import price determine domestic price. The differences in productivity and wage growth among different industries affect the relative price.

• Journal of agricultural medicine and community health
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• v.34 no.1
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• pp.113-123
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• 2009

Objectives: This study was performed to assess the effects of nutrition support for the elderly in rural communities. Methods: The data for this study were obtained from 148 aged over 65 years in G district(70 intervention group and 78 control group). General characteristics, physical health status, food intake, dietary habits, knowledge of nutrition and nutrition risk factors of the subjects were examined by individual interview. The participants were divided into two groups through the first questionnaire of nutrition: nutritional intervention group(nutritional intervention and education of nutrition) and control group(education of nutrition alone). Results: Nutritional intervention group showed significant increase of energy intake to 87.4% from 71.0% and of most nutrients except vitamin A and niacin after intervention. After nutritional intervention program, depression index was significantly decreased and changes of food habits, self-efficacy and conviction indices were significantly increased. Conclusions: This study showed that the nutritional intervention serving foods for short-term intervention period was very effective in improving the nutritional status. In addition, it suggested that it was not enough for nutritional improvement of the elderly to provide public health education or counseling alone, therefore, for achieving its goals, it should be needed proper nutritional supply to them.

• KDI Journal of Economic Policy
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• v.14 no.4
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• pp.3-26
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• 1992

The pupose of this paper is to construct a price determination model of the Korean economy and to find out the propogation mechanism of monetary and fiscal policies. The model is a small-size macroeconometric model consisted of ten core equations : consumption, investment, exports, imports, consumer price index, wage rate, corporate bond rate, potential GNP, capital stock, and GNP identity. The model is a Keynesian model : consumer price index is determined by markup over costs, and wage rate is expressed by Phillipse curve ralation. Two features of the model, however, distinguish this model from other macroeconometric models of the Korean economy. First of all, the estimation of potential GNP and the capital stock is endogenized as suggested by Haque, Lahiri, and Montiel (1990). This allows us to calculate the level of excess demand, which is defined as the difference between the actual GNP and the potential GNP. Second, interest rate, inflation and wages are all estimated as endogenous variables. Moreover, all quantity variables include price variables as important determinants. For instance, interest rate is an important determinant of consumption and investment. Exports and imports are determined by the real effective exchange rate. These two features make the interactions between excess demand and prices the driving forces of this model. In the model, any shock which affects quantity variable(s) affects excess demand, which in turn affects prices. This strong interaction between prices and quantities makes the model look like a classical model over the long run. That is, increases in money supply, government expenditures, and exchange rate (the price of the U.S. dollar in terms of Korean won) all have expansionery effects on the real GNP in the short run, but prices, wage, and interest rate all increase as a result. Over the long run, higher prices have dampenning effects on output. Therefore the level of real GNP turns out to be not much different from the baseline level ; on the other hand, the rates of inflation, wage and interest rate remain at higher levels.

• Journal of IKEEE
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• v.2 no.2 s.3
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• pp.278-284
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• 1998

This paper describes a l0b CMOS A/D converter (ADC) for HDTV applications. The proposed ADC adopts a typical multi-step pipelined architecture. The proposed circuit design techniques are as fo1lows: A selective channel-length adjustment technique for a bias circuit minimizes the mismatch of the bias current due to the short channel effect by supply voltage variations. A power reduction technique for a high-speed two-stage operational amplifier decreases the power consumption of amplifiers with wide bandwidths by turning on and off bias currents in the suggested sequence. A typical capacitor scaling technique optimizes the chip area and power dissipation of the ADC. The proposed ADC is designed and fabricated in s 0.8 um double-poly double-metal n-well CMOS technology. The measured differential and integral nonlinearities of the prototype ADC show less than ${\pm}0.6LSB\;and\;{\pm}2.0LSB$, respectively. The typical ADC power consumption is 119 mW at 3 V with a 40 MHz sampling rate, and 320 mW at 5 V with a 50 MHz sampling rate.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.9 s.351
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• pp.105-119
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• 2006

The car navigation system to be accompanied to the car on-board equipment system or the development of mobile communication technique, the demand in information communication which connects an interior and the car outside is coming to be high, As applications, ETC/VISC/AHS classes get deceived supply are advanced. The research of DSRC radio systems actively, with medium of communication between the automobile and road, is advanced. DSRC radio systems are appropriate in massive data transfer, in the case which the traffic accident evasion is urgent, the notarization of the preferential control function which is necessary to a medium of communication, guarantee and security are suitable in the high-speed network. Accompanied to the cellular phone which is to be supplied recently suddenly, By complementing and coexisting each other, and it will be developed simultaneously. However, in a connection of this kind of communication system and high-speed DSRC radio system, Hand-over technique (network, radio transmission hand-over), there is a technical subject of the high-speed transmission techniques against the mobile devices and the realization is expected to be difficult in near, until 2010 year is becoming the plan of putting to practical use. Also as the next generation DSRC with 5.8GHz built-on board equipment and the road-side equipment are expected in near. In this paper DSRC systems which will be developed are discussed.

• Applied Chemistry for Engineering
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• v.29 no.1
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• pp.10-17
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• 2018

POU (point of use) scrubbers were applied for the treatment of waste gases including PFCs (perfluorocompounds) exhausted from the CVD (chemical vapor deposition), etching, and cleaning processes of semiconductor and display manufacturing plant. The GWP (global warming potential) and atmosphere lifetime of PFCs are known to be a few thousands higher than that of $CO_2$, and extremely high temperature more than 3,000 K is required to thermally decompose PFCs. Therefore, POU gas scrubbers based on the thermal plasma technology were developed for the effective control of PFCs and industrial application of the technology. The thermal plasma technology encompasses the generation of powerful plasma via the optimization of the plasma torch, a highly stable power supply, and the matching technique between two components. In addition, the effective mixture of the high temperature plasma and waste gases was also necessary for the highly efficient abatement of PFCs. The purpose of this paper was to provide not only a useful technical information of the post-treatment process for the waste gas scrubbing but also a short perspective on R&D of POU plasma gas scrubbers.

• The Korean Journal of Malacology
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• v.15 no.1
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• pp.21-30
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• 1999

This study was carried out to describe the growth of Ruditapes philippinarum on Chohwa and Toksan tidal flat in Kwangyang Bay, from June 1994 to July 1995. On the Chohwa tidal flat, the mean gran size, organic content and chlorophyll-a of the surface sediment were the range of 2.50-4.46 , 4.99-5.11%, 14.53-19.90 $\mu\textrm{g}$ cm$\^$-3/, and on the Toksan tidal flat, 0.83-1.66 , 2.22-2.34%, 6.20-6.90 $\mu\textrm{g}$ cm$\^$-3/, respectively. The shell length of R. philippinarum increased rapidly from spring to summer, and gently from summer to autumn, and ceased during winter. Fresh weight increased during spring and autumn, and decreased during summer and winter. condition factors also showed the same variations of weights. Synthesized annual growth pattern of 4 year classes in shell length fitted the von Bertalnffy growth model well. The annual growth of weight fitted the Gompertz model relatively well. The values of w, initial shell growth rate, and AGR$\sub$max/, maximum weight growth rate, on the Chohwa tidal flat were lower than those on the Toksan tidal flat. Comparing the growth patterns in the same tidal flat, growth rate was higher on the lover tidal flat than those on the higher tidal flat. In conclusion, the Chohwa tidal flat maintaining higher density showed lover growth rate, because of relatively insufficient food supply and inhabiting space.