• The Journal of the Convergence on Culture Technology
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• v.6 no.2
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• pp.15-23
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• 2020

This study aimed to analyze effects of non-regular employment rate and female employment rate on fertility rate in OECD county. We adopted dynamic panel model after classifying OECD county to high and low fertility rate. The results of analysis showed that the higher non regular employment rate, the lower female employment rate, and the lower economy growth rate decrease fertility rate especially in low fertility rate country. While, only the higher house rental decrease in high fertility country. This results indicate that low fertility country including Korea should improve a labor policy such as strengthening employment security and encouraging female employment to increase fertility rate.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.1
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• pp.37-43
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• 2000

In this experimental study we proposed the double dielectric barrier discharge (DDBD) reactor to produce as high an electric field as possible. The experiment are conducted for applied voltage from 15 to 20[kV], $1~4[\ell/min]$ of gas flow rate and 120[Hz] and 240[Hz] of pulse rate. Superposition discharge(SPD) generated in DDBD which combined the surface discharge with the silence discharge was the most effective to reduce the $NO_x$. In the decomposition efficiency per watt, the low pulse rate gave better efficiency than the high pulse rate. However in DeNOx rate, the high pulse rate gave better performance than the low pulse rate. $NO_x$ removal rate and efficiency increased with increasing the applied voltage in all reactors.

• Food Science and Preservation
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• v.1 no.2
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• pp.87-92
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• 1994

For the measurement of the change of respiration rate caused by the gas content of storage atmosphere which furnishes important data for the interpretation of ULO storage, GC was used. It has been shown that the respiration rate and respiratory heat generation rate of Fuji apple is more than doubled in normal low temperature storage when compared with ULO storage, and that in ULO storage the respiration rate and respiratory heat generation rate directly proportional to the concentration of O2 in storage atmosphere as well as inversely proportional to that of CO2. It was possible to establish a functional formula for the respiratory heat generation rate of Fuji apple in all the storage conditions in terms of u=-0.7638+0.0003 O2-0.0007 log(CO2)+0.1369 log(Tb) concerning temperature and the concentration of O2 and CO2

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.4
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• pp.487-494
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• 2010

In order to test the applicability of bunker-A in a diesel engine for small-fishing boat, the investigation of the engine performance and the exhaust emission was performed under various conditions of fuel property, intake air pressure and fuel temperature. It was also performed based on IMO NOx Technical code. At high load, the energy consumption rate of bunker-A was lower than that of diesel oil, and the characteristics of exhaust emission of bunker-A were similar to those, and NOx emission rates of both fuels satisfied the IMO NOx emission regulation limits. The energy consumption rate and characteristics of exhaust emission were improved as the intake air pressure was increased, but these were not improved remarkably as the temperature of bunker-A was heated. However, at low load the energy consumption rate, CO emission rate and HC emission rate of bunker-A were higher than those of diesel oil, but NOx emission rates of the fuels were about the same. In addition, at low load the energy consumption rate and CO emission rate of bunker-A were increased as the intake air pressure and the temperature were higher than normal conditions. Accordingly, it is thought that the use of bunker-A in a kind of test engine is possible at high load. On the other hand, it is thought that more research is needed to improve the combustion efficiency under low temperature and low load condition.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.4
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• pp.50-57
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• 2009

This paper presents a new model-based macroblock layer rate control algorithm for low bit rate video coding which generates output bits corresponding to a target bit budget. The H.264 standard uses various coding modes and optimization methods to improve the compression performance, which makes it difficult to control the generated traffic accurately in low bit rate environments. In the proposed scheme, we first estimate MAD values of macroblocks in a frame and define a target remaining bits using the estimated MAD values before encoding each macroblock. If a difference between the target value and the actual value is greater than a threshold value, the quantization parameter is adjusted to decrease the difference. It is shown by experimental results that the new algorithm can obtain more than 66% decrease of the difference between the target bits and the resulting bits for a frame with the PSNR performance better than that of the existing rate control algorithm.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.2
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• pp.57-64
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• 2015

At the case of peak threshold algorithm, 3-axes data should sample step data over 20 Hz to get sufficient accuracy. But most of the digital sensors like 3-axes accelerometer have very low sampling rate caused by low data communication speed on limited SPI or $I^2C$ bandwidth of the low-cost MPU for ubiquitous devices. If the data transfer rate of the 3-axes accelerometer is getting slow, the sampling rate also slows down and it finally degrades the data accuracy. In this study, we proved there is a distinct functional relation between the sampling rate and threshold on the peak threshold step detection algorithm under the 20Hz frequency, and made a threshold function through the experiments. As a result of experiments, when we apply threshold value from the threshold function instead of fixed threshold value, the step detection error rate can be lessen about 1.2% or under. Therefore, we can suggest a peak threshold based new step detection algorithm with threshold function and it can enhance the accuracy of step detection and step count. This algorithm not only can be applied on a digital step counter design, but also can be adopted any other low-cost ubiquitous sensor devices subjected on low sampling rate.

• Journal of Environmental Science International
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• v.24 no.2
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• pp.221-228
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• 2015

In this research traditional Buddhist dietary life style was studied as an alternative for both saving water and decreasing water pollution from household. A traditional dietary life style for the Buddhist monks, called Balwoo Gongyang, and its modernized one for citizens, called Dish Gongyang were examined with water use amount, wastewater quality and pollutant loading rate, and were compared with the kitchen wastewater from household. And several types of natural detergent were also examined to compare their effect on the wastewater quality and pollutant loading rate. This research was carried out using the wastewater from Balwoo and Dish Gongyang in J building located in Seoul. Wastewater generation from Balwoo Gongyang that was about $1.0{\ell}$/capita/day was very low compare to that from dish washing in normal household($32.6{\ell}$/capita/day). In case of Dish Gongyang, water generation was 1.8 times higher than that from Balwoo Gongyang, but it was just 1/19.2 of normal household. When the wastewater quality of Balwoo Gongyang was compared with the kitchen wastewater of normal household, SS was 1/16($15mg/{\ell}$), COD was 1/7($22.1mg/{\ell}$), BOD was 1/9($24.1mg/{\ell}$) and T-N was 1/16($1.7mg/{\ell}$). Pollutant loading rate from Balwoo Gongyang was very low, COD 18.0 mg/capita/day, SS 12.3 mg/capita/day and it was 1/290, 1/639 of that from dish washing wastewater from normal household, respectively. Pollutant loading rate from Dish Gongyang was also low 1/13(SS)~1/144(TN) compared to dish washing wastewater from normal household. As a natural detergent, used water from washing rice showed very low pollutant loading rate. It was concluded that Dish Gongyang that was a modernized and simplified dietary life style of Balwoo Gongyang, was very eco-friendly. Especially when it was combined with natural detergents using by-product from cooking process, its effect on the water pollution was very low.

• Journal of Plant Biology
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• v.17 no.4
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• pp.31-37
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• 1974

Seedlings of Nongbaek representing strong cold tolerant variety of rice plant, Jinheung of medium variety and Tongil of weak variety were used respectively for the present study. These seedlings were water cultured in phytotron which maintained at the daytime and night temperature of 30-$25^{\circ}C$, 20-2$0^{\circ}C$, 20-15$^{\circ}C$ and 15-1$0^{\circ}C$. The growth rate of plant height, tillering rate, increase in dry weight and absorption pattern of important mineral nutrients at their early growth stage under each temperature conditions were observed. Generally, it appeared that Nongbaek was more active in the growth of plant height than Jinheung, and Jinheung was more active than Tongil under low temperature condition. The tillering rate of these three varieties was equally rapid while it was decreased in the order of weak cold tolerant variety, such as Tongil, Jinheung and Nongbaek as the temperature declined gradually. The dry weigh tincreasing curve showed almost the same pattern in the varieties at the treatment of each temperature. Under low temperature conditions, Nongbaek showed higher absorption rate of N per dry weight and higher absorption amount of per plant body, Jinheung followed and Tongil was the lowest. The absorption amount of P2O5 increased in the top part compared with the roots as temperature rose and decreased as temperature declined. There seemed to be no difference of absorption among the varieties which have different cold tolerance each other. Under low temperature the absorption rate of K per dry weight was high, as a whole, especially Nongbaek was markedly higher than the other two. The absorption rate of Ca, Mg and Fe was also equally high in all varieties under low temperature and Nongbaek showed a more absorptive tendency in the absorption amount under low temperature.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.295-298
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• 2006

Experiments in methane-air low strain rate counterflow diffusion flames diluted with nitrogen have been conducted to study the behavior of flame extinction and edge flame oscillation in which lateral conduction heat loss in addition to radiative heat loss could be remarkable at low global strain rates. Onset conditions of edge flame oscillation and flame oscillation modes are also provided with global strain rate. It is seen that flame length is closely relevant to lateral heat loss, and this affects flame extinction and edge flame oscillation. Edge flame oscillations in low strain rate flames are categorized into three: a growing oscillation mode, a decaying oscillation mode, and a harmonic oscillation mode. The regime of flame oscillation is also provided at low strain rate flames.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.1
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• pp.87-95
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• 2009

EGR(Exhaust gas recirculation) provides an important contribution in achieving the development targets of low fuel consumption and low exhaust emission levels on gasoline engine for hybrid vehicles while allowing stoichiometric fuelling to be retained for applications using the three-way catalysts. However, the occurrence of excessive cyclic variation with high EGR normally prevents substantial fuel economy improvements from being achieved in practice. Therefore, the optimum EGR rate in gasoline engine for hybrid vehicles should be carefully determined in order to achieve low fuel consumption and low exhaust emission. In this study, 2 liters gasoline engine with E-EGR system was used to investigate the effects of EGR with optimum EGR rate on fuel economy, combustion stability, engine performance and exhaust emissions. As the engine load becomes higher, the optimum EGR rate tends to increase. The increase in engine load and reduction in engine speed make the fuel consumption better. The fuel consumption was improved by maximum 5.5% at low speed, high load operating condition. As the simulated EGR variation on a cylinder is increased, due to the increase in cyclic variation, the fuel consumption and emissions characteristics were deteriorated simultaneously. To achieve combustion stability without a penalty in fuel consumption and emissions, the cylinder-to-cylinder variations must be maintained under 10%.