• Journal of Life Science
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• v.21 no.7
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• pp.1032-1038
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• 2011

Recently identified Ciona intestinalis voltage sensor-containing phosphatase (Ci-VSP) consists of an ion channel-like transmembrane domain (VSD) and a phosphatase-like domain. Ci-VSP senses the change of membrane potential by its VSD and works as a phosphoinositide phosphatase by its phosphatase domain. In this study, we present the construction of His-tagged phosphatase-like domain of Ci-VSP, its recombinant expression and purification, and its enzymatic activity behavior in order to examine the biochemical behavior of phosphatase domain of Ci-VSP without interference. We found that Ci-VSP(248-576)-His can be eluted with an elution buffer containing 25 mM NaCl and 100 mM imidazole during His-tag purification. In addition, we found the proper measurement condition for kinetics study of Ci-VSP(248-576)-His against p-nitrophenyl phosphate (pNPP). We measured the kinetic constant of Ci-VSP(248-576)-His at $37^{\circ}C$, pH 5.0 or 5.5, under 30 min of reaction time, and less than $2.0\;{\mu}g$ of protein amount. With these conditions, we acquired that Ci-VSP(248-576)-His has $K_m$ of $354{\pm}0.143\;{\mu}M$, $V_{max}$ of $0.0607{\pm}0.0137\;{\mu}mol$/min/mg and $k_{cat}$ of $0.359{\pm}0.009751\;min^{-1}$ for pNPP dephosphorylation. Therefore, we produced a pure form of Ci-VSP(248-576)-His, and this showed a higher activity against pNPP. This purified protein will provide the road to a structural investigation on an interesting protein, Ci-VSP.

• Journal of Intelligence and Information Systems
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• v.20 no.2
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• pp.59-71
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• 2014

System trading is becoming more popular among Korean traders recently. System traders use automatic order systems based on the system generated buy and sell signals. These signals are generated from the predetermined entry and exit rules that were coded by system traders. Most researches on system trading have focused on designing profitable entry and exit rules using technical indicators. However, market conditions, strategy characteristics, and money management also have influences on the profitability of the system trading. Unexpected price deviations from the predetermined trading rules can incur large losses to system traders. Therefore, most professional traders use strategy portfolios rather than only one strategy. Building a good strategy portfolio is important because trading performance depends on strategy portfolios. Despite of the importance of designing strategy portfolio, rule of thumb methods have been used to select trading strategies. In this study, we propose a SVM-based strategy portfolio management system. SVM were introduced by Vapnik and is known to be effective for data mining area. It can build good portfolios within a very short period of time. Since SVM minimizes structural risks, it is best suitable for the futures trading market in which prices do not move exactly the same as the past. Our system trading strategies include moving-average cross system, MACD cross system, trend-following system, buy dips and sell rallies system, DMI system, Keltner channel system, Bollinger Bands system, and Fibonacci system. These strategies are well known and frequently being used by many professional traders. We program these strategies for generating automated system signals for entry and exit. We propose SVM-based strategies selection system and portfolio construction and order routing system. Strategies selection system is a portfolio training system. It generates training data and makes SVM model using optimal portfolio. We make $m{\times}n$ data matrix by dividing KOSPI 200 index futures data with a same period. Optimal strategy portfolio is derived from analyzing each strategy performance. SVM model is generated based on this data and optimal strategy portfolio. We use 80% of the data for training and the remaining 20% is used for testing the strategy. For training, we select two strategies which show the highest profit in the next day. Selection method 1 selects two strategies and method 2 selects maximum two strategies which show profit more than 0.1 point. We use one-against-all method which has fast processing time. We analyse the daily data of KOSPI 200 index futures contracts from January 1990 to November 2011. Price change rates for 50 days are used as SVM input data. The training period is from January 1990 to March 2007 and the test period is from March 2007 to November 2011. We suggest three benchmark strategies portfolio. BM1 holds two contracts of KOSPI 200 index futures for testing period. BM2 is constructed as two strategies which show the largest cumulative profit during 30 days before testing starts. BM3 has two strategies which show best profits during testing period. Trading cost include brokerage commission cost and slippage cost. The proposed strategy portfolio management system shows profit more than double of the benchmark portfolios. BM1 shows 103.44 point profit, BM2 shows 488.61 point profit, and BM3 shows 502.41 point profit after deducting trading cost. The best benchmark is the portfolio of the two best profit strategies during the test period. The proposed system 1 shows 706.22 point profit and proposed system 2 shows 768.95 point profit after deducting trading cost. The equity curves for the entire period show stable pattern. With higher profit, this suggests a good trading direction for system traders. We can make more stable and more profitable portfolios if we add money management module to the system.

• Korean Journal of Remote Sensing
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• v.37 no.5_2
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• pp.1295-1305
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• 2021

Satellite-derived ocean color products are required to effectively monitor clear open ocean and coastal water regions for various research fields. For this purpose, accurate correction of atmospheric effect is essential. Currently, the Geostationary Ocean Color Imager (GOCI)-II ground segment uses the reanalysis of meteorological fields such as European Centre for Medium-Range Weather Forecasts (ECMWF) or National Centers for Environmental Prediction (NCEP) to correct gas absorption by water vapor and ozone. In this process, uncertainties may occur due to the low spatiotemporal resolution of the meteorological data. In this study, we develop water vapor absorption correction model for the GK-2 combined GOCI-II atmospheric correction using Advanced Meteorological Imager (AMI) total precipitable water (TPW) information through radiative transfer model simulations. Also, we investigate the impact of the developed model on GOCI products. Overall, the errors with and without water vapor absorption correction in the top-of-atmosphere (TOA) reflectance at 620 nm and 680 nm are only 1.3% and 0.27%, indicating that there is no significant effect by the water vapor absorption model. However, the GK-2A combined water vapor absorption model has the large impacts at the 709 nm channel, as revealing error of 6 to 15% depending on the solar zenith angle and the TPW. We also found more significant impacts of the GK-2 combined water vapor absorption model on Rayleigh-corrected reflectance at all GOCI-II spectral bands. The errors generated from the TOA reflectance is greatly amplified, showing a large error of 1.46~4.98, 7.53~19.53, 0.25~0.64, 14.74~40.5, 8.2~18.56, 5.7~11.9% for from 620 nm to 865 nm, repectively, depending on the SZA. This study emphasizes the water vapor correction model can affect the accuracy and stability of ocean color products, and implies that the accuracy of GOCI-II ocean color products can be improved through fusion with GK-2A/AMI.

• The Korean Journal of Pharmacology
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• v.31 no.1 s.57
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• pp.63-74
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• 1995

It has been known that, during hypoxia, the adrenal medulla is activated to release catecholamines (CA) while hypoxia also inhibits high $K^+$ -induced CA secretion in the cultured bovine adrenal chromaffin cells. The present study was attempted to examine the effect of hypoxia on CA secretion evoked by chlinergic stimulation and membrane-depolarization from the isolated perfused rat adrenal glands and also to clarify its mechanism of action. For this purpose, using the isolated rat adrenal glands, the effects of hypoxia on CA release evoked by nicotinic ($N_1$) and muscarinic ($M_1$) receptor agonists, membrane-depolarizing agent, $Ca^{++}$-channel activator, intracellular $Ca^{++}$-releaser and ACh were determined. Experiments were carried out, perfusing Krebs solution pre-equilibrated with a gas mixture of 95% N_2$ and 5% $CO_2$. Hypoxia was maintained for $3{\sim}4$ hours through the experiments. Hypoxia gradually caused a time-dependent seduction in CA secretion evoked by DMPP ($100{\mu}M$), McN-A-343 ($100{\mu}M$), ACh (5.32 mM), Bay-K-8644 ($10{\mu}M$) and high $K^+$ (56 mM) respectively. How-ever, it did not affect CA secretion evoked by cyclopiazonic acid ($10{\mu}M$). Hypoxia itself also did fail to produce any influence on spontaneous secretory response of CA. These experimental results suggest that hypoxia depresses CA release evoked by both cholinergic stimulation and membrane-depolarization from the isolated rat adrenal medulla, and that this inhibitory activity may be due to the result of the direct inhibition of $Ca^{++}$ influx into the chromaffin cells without any effect on the calcium mobilization from the intracellular store.

• Journal of Broadcast Engineering
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• v.22 no.6
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• pp.829-849
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• 2017

Due to the large-scale TV display, the convergence of broadcasting and broadband, and the advancement of signal compression and transmission technology, terrestrial digital broadcasting has evolved into UHD broadcasting capable of providing simultaneous broadcasting of fixed UHD and mobile HD. The Korean standard for terrestrial UHDTV broadcasting is based on ATSC 3.0, the broadcasting standard of North America. The terrestrial UHDTV broadcasting standard chose that as a new AV codec standard, HEVC video codec which can compress with higher efficiency compared to AVC, and MPEG-H 3D audio codec for realistic audio. Also, DASH and MMT are adopted as transmission format instead of MPEG-2 TS to support broadband as well as broadcasting network, and in order to provide 4K UHD/mobile HD service simultaneously ROUTE multiplexing technology is applied. In this paper, we propose an audio/video encoder, which is required to provide HDR/WCG supported high quality video service, 10.2 channel/4 object supporting stereo sound service, fixed UHD and mobile HD simultaneous broadcasting service based on ATSC3.0, also we implemented the ATSC 3.0 LDM system for ROUTE/DASH packager, multiplexing system and physical layer transmission/reception, and verified the service ability by applying it to real time broadcast environment.

• Korean Security Journal
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• no.24
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• pp.147-170
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• 2010

This study is to present a improvement directions for the protection of industrial key technology. For the purpose of the study, the survey was carried out on the administrative security activity of 68 enterprises including Large companies, small-midium companies and public corporations. survey result on the 10 items of security policy, 10 items of personal management and 7 items of the assets management are as follows; First, stable foundation for the efficient implement of security policy is needed. Carrying a security policy into practice and continuous upgrade should be fulfilled with drawing-up of the policy. Also for the vitalization of security activity, arrangement of security organization and security manager are needed with mutual assistance in the company. Periodic security inspection should be practiced for the improvement of security level and security understanding. Second, the increase of investment for security job is needed for security invigoration. Securing cooperation channel with professional security facility such as National Intelligence Service, Korea internet & security agency, Information security consulting company, security research institute is needed, also security outsourcing could be considered as the method of above investment. Especially small-midium company is very vulnerable compared with Large company and public corporation in security management, so increase of government's budget for security support system is necessary. Third, human resource management is important, because the main cause of leak of confidential information is person. Regular education rate for new employee and staff members is relatively high, but the vitalization of security oath for staff members and the third party who access to key technology is necessary. Also access right to key information should be changed whenever access right changes. Reinforcement of management of resigned person such as security oath, the elimination of access right to key information and the deletion of account. is needed. Forth, the control and management of important asset including patent and design should be tightened. Classification of importance of asset and periodic inspection are necessary with the effects evaluation of leak of asset.

• Journal of the Korean Geographical Society
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• v.36 no.2
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• pp.111-125
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• 2001

An estuary is semi-inclosed inlets, located between terrestrial and marine environment. Since many estuaries along south-western coasts of Korean peninsula were affected by human settlements and activities, significant changes in sedimentation environments have been observed. The research area is divided into three distinct morpho-stratigraphic units: fluvial dominated area(Area1), mixed area(Area 2), tide-dominated area(Area3). The landform of this area has been changed by reclamation and river channel change. Temporal variations affected by dam construction, periodic freshet was iterrupted. Sediments began to continuously accmulate on estuary banks by tide. Meanwhile, because of the continuous but reduced discharge of fresh water, the salinity of estuarine sediments was declined. That processes made vegetated area( Phregmites lonivalvis and Suaeda japonica) to be expanded. It indicates that the magnitude and frequency of geomorphic processes has been significantly changed.

• Journal of Nutrition and Health
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• v.53 no.2
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• pp.215-229
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• 2020

Purpose: This study examines the attitude of South Korean adults toward food aid to North Korea and factors associated with it. Methods: An online survey involving 1,000 adults aged 19-69 years was conducted between September-October 2019. Throughout South Korea, the subjects were proportionally distributed with respect to gender, age, and region, to represent South Korean adults. Results: A total of 44.6% of the respondents agreed (Agreement group), 36.7% disagreed (Disagreement group), and 18.7% neither agreed nor disagreed to food aid to North Korea. Compared to the Disagreement group, the Agreement group had a higher concern of food aid to North Korea and a more positive perception on the effect of it. The Agreement group selected "direct assistance from the government" whereas the Disagreement group chose "support through international organizations" as the most appropriate channel for food aid to North Korea. Logistic regression analysis revealed that South Korean adults showing a more positive perception on the effect of food aid to North Korea were more likely to agree to the aid (odds ratio [OR], 19.32). Moreover, compared to the conservatives, the progressives were more likely to agree to food aid to North Korea (OR, 5.94). South Korean adults in their 40-50s were more likely to agree to food aid to North Korea than those in their 20-30s (OR, 2.81). South Korean adults with a higher concern of food aid to North Korea (OR, 3.93) and a greater positive perception on Korean unification (OR, 1.88) were more likely to agree to food aid to North Korea. Conclusion: The most important factor associated with the attitude of South Korean adults toward food aid to North Korea was their perception on the subsequent effect. As strategies to draw social consensus on food aid to North Korea, we recommend systematizing the monitoring process on the effect of providing food aid to North Korea and informing the public of the outcomes.

• Journal of Biosystems Engineering
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• v.7 no.2
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• pp.18-29
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• 1983

A low cost and versatile data acquisition system for the field and laboratory use was developed by using a single board microcomputer. Data acquisition system based on a Z80 microprocessor was built, tested and modified to obtain the present functional system. The microcomputer developed consists of 6 kB ROM, 5 kB RAM, 6-seven segment LED display, 16-Hex. key and 8 command key board. And it interfaces with an 8 channel, 12 bits A/D converter, a microprinter, EPROM programmer for 2716, and RS232C interface to transfer data between the system and HP3000 mini-computer manufactured by Hewlett Packard Co., A software package was also developed, tested, and modified for the system. This package included drivers for the AID converter, LED display, key board, microprinter, EPROM programmer, and RS232c interface. All of these programs were written in 280 assembler language and converted to machine codes using a cross assembler by HP3000 computer to the system during modifying stage by data transferring unit of this system, then the machine language wrote to the EPROM by this EPROM programmer. The results are summarized as follows: 1. Measuring program developed was able to control the measuring intervals, No. of channels used, and No. of data, where the maximum measuring speed was 58.8 microsec. 2. Calibration of the system was performed with triangle wave generated by a function generator. The results of calibration agreed well to the test results. 3. The measured data was able to be written into EPROM, then the EPROM data was compared with original data. It took only 75 sec. for the developed program to write the data of 2 kB the EPROM. 4. For the slow speed measurements, microprinter instead of EPROM programmer proved to be useful. It took about 15 min. for microprinter to write the data of 2 kB. 5. Modified data transferring unit was very effective in communicating between the system and HP3000 computer. The required time for data transferring was only 1~2 min. 6. By using DC/DC converting devices such as 78-series, 79-series. and TL497 IC, this system was modified to convert the only one input power sources to the various powers. The available power sources of the system was DC 7~25 V and 1.8 A.

• Research in Community and Public Health Nursing
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• v.8 no.2
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• pp.347-367
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• 1997

The purpose of this study was to investigate drug abuse and to find related factors among high school students. The subjects for this study were 973 students from 10 high schools in Taegu city. The data were collected from September 30, 1996 to October 30, 1996. The questionnaire developed by Kim Soyoaja (1991) surveyed adolescent drug use and questions on smoking and drinking were readjusted and added by the researcher based on review. The data was analyzed using frequency, percentage, $X^2-test$, t -test, Pearson Correlation Coefficient with the SPSS /PC+. The results of this study were summarized as follows: 1. The proportion of students who drank alcohol 1-2 times or more per year was 52.4% and smoked Cigarette 1 -2 times or more per year was 20.8%. The 7 different drugs(Analgetics 5.7%. sleeping pills and sedatives 4.2%, antihistamines 1.1%. stimulants 7.7%, hallucinogens 0.8%, inhalants 3.3%, and narcotics 0.6%) were also evaluated. 2. There was a significant relationship between drinking and type of school($X^2$=62.97, p<.0l), grades($X^2$=33.86, P<.001), school life($X^2$= 19.04, p<.001), and delinquent friends($X^2$= 64.72, P<.001). 3. There was a significant relationship between smoking and type of school($X^2$=153.65, p<.001), grades ($X^2$=67.53, p<.001), their respect for teachers ($X^2$=33.80, p<.001) school life($X^2$ =50.87, p<.001), and delinquent friends($X^2$ =85.28, p<.001). 4. There was a significant relationship between the 7 different kinds of drug abuse and type of school ($X^2$=14.65, p<.01), grades($X^2$=12.89, p<.01), their respect for teachers ($X^2$=8.46, p<.05), and delinquent friends($X^2$=22.42, p<.001). 5. There was a significant relationship between a parent's habitual drug abuse and the 7 different kinds of drug abuse($X^2$=7.78, p<.01), as well as a parent's attitude toward drugs and the 7 different kinds of drug abuse($X^2$=6.33, p<.05). 6. There was a significant difference between drinking(t=-12.53, p<.001), smoking(t=-15.98, p<.001), the 7 different kinds of drug abuse(t=-5.77, p<.001), and the respondant's delinquent experience. 7. There was a correlation between drinking and smoking(r=.4166, p<.001), drinking and the 7 different kinds of drug abuse(r=.2200, p<.001), smoking and the 7 different kinds of drug abuse(r=.1428, p<.05). There was a correlation between drinking and smoking(r=.5977, p<.001), drinking and the 7 different kinds of drug abuse(r=.2849, p<. 001), smoking and the 7 different kinds of drug abuse(r=.1711, p<.05) among male students. There was a correlation between drinking and smoking(r=.4219, p<.001), drinking and the 7 different kinds of drug abuse(r=.2611, p<.001), smoking and the 7 different kinds of drug abuse(r=.1764, p<.001) among female students. 8. There was a correlation between drinking and family stability(r=.0709, p<.05) drinkry and parent -child relationships (r=.1321, p<.01), drinking and mother's rearing attitude(r=.0704, P<.05), smoking and parent -child relationships(r=.0813, P<.05). There was a correlation between drinking and family stability(r=.14S7, p<.01), drinkng and parent-child relationships(r=.2147, p<.001), smoking and family stability(r=.1544, p<.01), smoking and parent. -child relationships (r=. 2018, P<.01) among male students. There was a correlation between drinking and family stability(r=.1l21, p<.05), drinking and mother's rearing attitude (r=.0988, P<.05), smoking and parent -child relationships (r=. 0940, P<.05) among female students. 9. There was a significant difference between the 7 different kinds of drug abuse and family stability (t=2.23, p<.05), parent-child relationships (t=4. 34, p<.001), satisfaction with family (t=4.02, p<.001), father's rearing attitude(t=3.04, p<.01), mother's rearing attitude(t=2.87, p<.01). The distribution channel of drugs including alcohol beverages and cigarettes should be evaluated and restructured to discourage student's temptation and to limit accessibility. The step by step preventive teaching on alcohol drinking and cigarette smoking is needed from middle school to help prevent further drug abuse.