• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.2
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• pp.125-130
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• 2005

This study was peformed to investigate the phase change temperature, the supercooling, the maintenance time of liquid phase and the change rate of volume of TMA 30 $wt\% clathrate compound with additives. TMA 30 $wt\% clathrate compound with additive was cooled at heat source temperature of $-6^{circ}C$. The additives are ethylene glycol and chloroform. Their concentration are 0.1$wt\% respectively. The experimental results showed that the phase change temperature was not affected by additives and this was average $5.3^{circ}C$. Also the supercooling and the maintenance time of liquid phase were decreased by additives. Especially, the average value of supercooling showed by $8.8^{circ}C$ and the maintenance time of liquid phase was by 19 minutes in the case of chloroform 0.1$wt\%. Additionally, the average change rate of volume showed by $1.26{\~}1.31\%$ according to additives and the volume was decreased by the phase change from liquid to solid.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.1
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• pp.198-210
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• 2016

This study firstly aims to estimate a leading-price of Jeju flounders with various price-classes by fish weight and secondly plans to provide policy implications of flounder purchase projects by understanding dynamic changes and interactions among flounder producer price-classes caused by price impulses in the market. This study applies an unit root test for stability of data, uses a Granger causality test to estimate the leading-price among producer prices by fish weight, employs the vector autoregressive model to analyze statistical impacts among t-1 variables used in models, and finally utilizes impulse response analyses and forecast error variance decomposition analyses to understand dynamic changes and interactions among change rates of the producer prices caused by price impulses in the market. The results of the study are as follows. Firstly, KPSS, PP, and ADF tests show that the change rate of Jeju flounder monthly producer prices by fish weight differentiated by logarithm is stable. Secondly, the Granger causality test presents that the change rate of the 1kg flounder producer price strongly leads it of 500g, 700g, and 2kg flounder producer prices respectively. Thirdly, the vector autoregressive model indicates that the change rate of the 1kg producer price in t-1 period statistically, significantly influences it of own weight in t period and also slightly affects price change rates of other weights in t period. Fourthly, the impulse response analysis indicates that impulse responses of structural shocks for the change rate of the 1kg producer price are relatively more powerful in its own weight and in other weights than shocks emanating from price change rates of other weights. Fifthly, the variance decomposition analysis points out that the change rate of the 1kg producer price is relatively more influential than it of 500g, 700g, and 2kg producer prices respectively. In conclusion, the change rate of the 1kg Jeju flounder producer price leads the change rates of other ones and Jeju purchase projects need to be targeted to the 1kg Jeju flounder producer price as the purchase project implemented in 2014.

• International Journal of Reliability and Applications
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• v.1 no.2
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• pp.115-121
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• 2000

The trend change in aging properties, such as failure rate and mean residual life, of a life distribution is important to engineers and reliability analysts. In this paper we develop a test statistic for testing whether or not the failure rate changes its trend using censored data. The asymptotic normality of the test statistics is established. We discuss the efficiency values of loss due to censoring.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.1
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• pp.24-28
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• 1995

Exercise physiology of fish was studied by means of Electro-cardio-gram(ECG) technique with wired electrode system. Effects of swimming activity on the heart rate change for carp Cyprinus carpio was observed and analysed under swimming speeds among 1~3 Body Length/s and swimming durations of 10 and 60 minutes in the flume tank. The heart rate increase during swimming activity was observed in higher speed and longer duration conditions. The exercise effect on the heart rate continued even after fish stopped swimming. The time for recovery after exercise was tended to be elongated with the higher exercise condition.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1995.06a
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• pp.109-112
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• 1995

A rate control strategy in the MPEG is critical to the quality of the reconstructed image sequence. In this paper, were propose a rate control algorithm which can improve the coding performance for a given bit constraint. The proposed algorithm use the distortion-rate curve for the fine adjustment of the quantization scaling factor of each region. This algorithm can also handle the problem due to scene change effectively. It can be easily applicable to existing MPEG coders. Simulation results show that the performance for the algorithm is better than the rate control algorithm in the MPEG-2 TM5.

• International Commerce and Information Review
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• v.9 no.3
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• pp.151-160
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• 2007

The purpose of this study is to estimate the risk premium hedge ratio in foreign exchange risk of the foreign exchange rate insurance. The applicants of exchange rate insurance and Korea Export Insurance Corporation will be facing the risk in change of currency and guaranteed currency’s swap point upon contract being made. Also upon making decision of hedging exchange rate insurance, the company will need to be aware of the risk causing due to change in swap point.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.38-38
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• 2021

The seeds of rice with variable status were examined the germination rate after 10 years of long-term storage (-18℃) conservation. For seeds of wild relatives, 2 accessions were examined and germination rate of all accessions showed no changed after freezing conservation. For seeds of native germplasm, 1,259 accessions were examined and germination rate of 696 accessions was increased or showed no change after 10 years of long-term storage. Germination rate of 432 accessions was decreased with below 15% of initial germination rate. For 79 accessions of native germplasm, germination rate of seeds was decreased with above 15% of initial germination rate after 10 years of long-term storage, which is needed to be rejuvenated. For seeds of developed varieties, 873 accessions were examined and germination rate of 486 accessions of developed varieties was increased or showed no change after 10 years of long-term storage. Germination rate of 251 accessions was decreased with below 15% of initial germination rate. For 25 accessions of developed varieties, germination rate of seeds was decreased with above 15% of initial germination rate after 10 years of long-term storage, which is needed to be rejuvenated. For seeds of developed line, 2,131 accessions were examined and germination rate of 1,245 accessions of developed line was increased or showed no change after 10 years of long-term storage. Germination rate of 588 accessions was decreased with below 15% of initial germination rate. For 96 accessions, germination rate of seeds was decreased with above 15% of initial germination rate, which is needed to be rejuvenated.

• Journal of the Korea Institute of Building Construction
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• v.7 no.4
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• pp.139-144
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• 2007

The purpose of this study is to analyze concrete characteristics by admixing agent and additive contents according to the change of unit-water to identify its effect on compressive strength. First of all, as for flesh concrete, overall unit-water showed a tendency to decrease as component inclusion rate of admixing agent was increased. In addition, air content showed a tendency to increase by increasing WR, WB, NP series admixing agent contents, on the other hand, the change of air content was gentle by around $1.5{\pm}0.5%$ for S, T, M series agents. Bulk density showed an inverse proportion to the change of air content. As for hardened concrete, expression rate of 3-day age compressive strength was generally decreased for S, T, WR, WB, NP, M series admixing agent component. Also, expression rate of 7-day age compressive strength showed an excellent record for S, M series agents, and expression rate of 28-day age compressive strength showed a tendency to increase more than plain on the whole.

• Proceedings of the KSRS Conference
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• v.2
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• pp.535-538
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• 2006

The coastline of the Choa Phraya Rivermouth in the Upper Gulf of Thailand has been changed drastically. The western side especially at Ban Laem Sing was eroded for 400 meter in 26 years or with the rate of 15 meter per year on the average. The Metropolitan Electricity Authority has granted five years research project to us to study the efficiency of the electric pole fence as a mean to reduce the wave force and increase sedimentation rate inside for mangrove replantation. If the method works efficiently, it will be used to reclaim the coastal land loss in other areas in Thailand. The project was done since 2005 after the fence was constructed completely in October 2005. The oceanographic surveys were conducted before and after the construction in northeast monsoon season to study the impact of physical oceanographic forces on the coastline change. The sedimentation rates were measured each month. It is rather low about 2 cm/month. The subsiding rate from the load of deltaic sediment and groundwater withdraw using boring data is about 30 mm/year. The cumulative sinking rate is 55.8 cm from 1978 to 1995. We have tried to design the method of mangrove plantation in this area. The remote sensing data such as LANDSAT and aerial photos from 1987 to 2002 for 15 years were used to compute the rate of coastline change at each 50 m section along the western side of the rivermouth.

• The Journal of Fisheries Business Administration
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• v.40 no.1
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• pp.27-49
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• 2009

Recently, the Korea's economy concerns the second money crisis because of the rapid increase of the exchange rate. The Korea's economy which is very dependent on the foreign trade is more sensitive to the change of exchange rates. There are many literatures which analyze the effects of variations of the exchange rates on the secondary and tertiary industries such as the manufacturing industry and IT(Information Technology). But there have been no studies which try to figure out the effects of variations of exchange rate on the primary industries, especially, fisheries' industry. Therefore this paper tries to analyze the effect of price competition structure and the change of exchange rate on foreign fisheries exporting prices in Korea's fisheries import market. This study utilizes OLS(Ordinary Least Squares Analysis) for the analysis in the market of frozen yellow corvina, hairtail, angler fish which are major fisheries importable in Korea. The results show that the exporting country which has the highest market share is more sensitive to the change of the exchange rates itself than that of the other exporting countries' price when it starts to set up its exporting price. And the exporting countries which have low market share are more sensitive to the change of price which country has the highest market share than that of price whose countries have low market share and those of their exchange rate. Also we can find out that the countries which have similar market share try to set up price-setting strategy in the opposite direction. In other words, one country tries to bid up its price, other countries response to rival country by lowering their prices. In the consideration of the fact that most exporting countries aren't affected by Korea's fisheries' prices, the exporting countries in Korea's fisheries import market are more sensitive to the prices of other exporting countries than that of Korea's. This result indicates that the price leader-follower model could be applicable to the Korea's fisheries import market.