• Communications for Statistical Applications and Methods
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• v.31 no.1
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• pp.105-127
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• 2024

We propose recurrent neural network (RNN) methods for forecasting realized volatility (RV). The data are RVs of ten major stock price indices, four from the US, and six from the EU. Forecasts are made for relative ratio of adjacent RVs instead of the RV itself in order to avoid the out-of-scale issue. Forecasts of RV ratios distribution are first constructed from which those of RVs are computed which are shown to be better than forecasts constructed directly from RV. The apparent asymmetry of RV ratio is addressed by the Piecewise Min-max (PM) normalization. The serial dependence of the ratio data renders us to consider two architectures, long short-term memory (LSTM) and gated recurrent unit (GRU). The hyperparameters of LSTM and GRU are tuned by the nested cross validation. The RNN forecast with the PM normalization and ratio transformation is shown to outperform other forecasts by other RNN models and by benchmarking models of the AR model, the support vector machine (SVM), the deep neural network (DNN), and the convolutional neural network (CNN).

• Culinary science and hospitality research
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• v.18 no.2
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• pp.149-161
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• 2012

The purpose of this study is to examine the quality characteristics of lamb stock by different salt contents in it. For this purpose, mechanical tests (color value, pH, sugar content, salinity, amino-acid content) and sensory evaluation (attribute difference test & acceptance) were conducted, showing the following results; Salinity and sugar increased significantly (p<0.01, p<0.001) with salt contents increased. The 0.1% salt addition group contained 32 kinds of free amino-acids, while 0.2% and 0.3% contained 34. 0.4% salt addition group turned out to contain 34 kinds of free amino-acid in it. The amount of the free amino-acid content was also the highest with 0.3% sample group, followed by 0.2%, 0.4%, and 0.1% sample group. In the test group, 9 kinds of essential amino-acid were discovered, and all samples contained histidine and arginine, which were essential in the growth of children. Among all samples, arginine appeared to be the highest in content. Each of the essential amino-acid content varied with statistical significance among the sample groups. In addition, 14 kinds of amino-acids other than the above mentioned were discovered, as well. The 0.3% salt addition group showed the highest 'after taste' value, and the differences among the sample groups were statistically significant(p<0.001). The acceptance test of the lamb stock showed that the flavor and mouth feel did not vary among the sample groups with statistical significance. The control group had the highest value for appearance, measuring scoring 4.32, and the sample group of 0.2% salt addition showed the lowest value of appearance, scoring 3.63. As for the preference on the taste, the highest value of 4.09 came from the 0.3% salt addition group. The differences between the sample groups were statistically significant. Finally, with regard to the overall quality, the 0.3% salt addition group had the highest value of 4.23 while the control group scored the lowest, 3.52. The differences among the samples were statistically significant. The overall result of the study indicated that the optimal rate of salt addition in making lamb stock was 0.3%.

• Journal of Intelligence and Information Systems
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• v.17 no.3
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• pp.187-201
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• 2011

KOSPI200 index is the Korean stock price index consisting of actively traded 200 stocks in the Korean stock market. Its base value of 100 was set on January 3, 1990. The Korea Exchange (KRX) developed derivatives markets on the KOSPI200 index. KOSPI200 index futures market, introduced in 1996, has become one of the most actively traded indexes markets in the world. Traders can make profit by entering a long position on the KOSPI200 index futures contract if the KOSPI200 index will rise in the future. Likewise, they can make profit by entering a short position if the KOSPI200 index will decline in the future. Basically, KOSPI200 index futures trading is a short-term zero-sum game and therefore most futures traders are using technical indicators. Advanced traders make stable profits by using system trading technique, also known as algorithm trading. Algorithm trading uses computer programs for receiving real-time stock market data, analyzing stock price movements with various technical indicators and automatically entering trading orders such as timing, price or quantity of the order without any human intervention. Recent studies have shown the usefulness of artificial intelligent systems in forecasting stock prices or investment risk. KOSPI200 index data is numerical time-series data which is a sequence of data points measured at successive uniform time intervals such as minute, day, week or month. KOSPI200 index futures traders use technical analysis to find out some patterns on the time-series chart. Although there are many technical indicators, their results indicate the market states among bull, bear and flat. Most strategies based on technical analysis are divided into trend following strategy and non-trend following strategy. Both strategies decide the market states based on the patterns of the KOSPI200 index time-series data. This goes well with Markov model (MM). Everybody knows that the next price is upper or lower than the last price or similar to the last price, and knows that the next price is influenced by the last price. However, nobody knows the exact status of the next price whether it goes up or down or flat. So, hidden Markov model (HMM) is better fitted than MM. HMM is divided into discrete HMM (DHMM) and continuous HMM (CHMM). The only difference between DHMM and CHMM is in their representation of state probabilities. DHMM uses discrete probability density function and CHMM uses continuous probability density function such as Gaussian Mixture Model. KOSPI200 index values are real number and these follow a continuous probability density function, so CHMM is proper than DHMM for the KOSPI200 index. In this paper, we present an artificial intelligent trading system based on CHMM for the KOSPI200 index futures system traders. Traders have experienced on technical trading for the KOSPI200 index futures market ever since the introduction of the KOSPI200 index futures market. They have applied many strategies to make profit in trading the KOSPI200 index futures. Some strategies are based on technical indicators such as moving averages or stochastics, and others are based on candlestick patterns such as three outside up, three outside down, harami or doji star. We show a trading system of moving average cross strategy based on CHMM, and we compare it to a traditional algorithmic trading system. We set the parameter values of moving averages at common values used by market practitioners. Empirical results are presented to compare the simulation performance with the traditional algorithmic trading system using long-term daily KOSPI200 index data of more than 20 years. Our suggested trading system shows higher trading performance than naive system trading.

• Korean Journal of Weed Science
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• v.16 no.3
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• pp.221-229
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• 1996

This study was carried out to determine the effects of growth regulators, carbon sources and silver nitrate on callus formation and plant regeneration of turfgrass. The results were summarized as fallows : Callus from Korean lawngrass (Zoysia japonica Steud.) and pencross creeping bentgrass (Agrostis palustrir Huds.) induced better in MS medium than in N6 medium and by addition of 2,4-D than by that of NAA. Callus formation from Korean lawngrass and penncross creeping bentgrass was very effective at MS medium adding 1mg/L 2,4-D and at the medium adding 2mg/L 2,4-D, repectively. Growth of callus was good at MS medium containing 2mg/L 2,4-D+0.2mg/L NAA. Callus growth of Korean lawngrass and penncross creeping bentgrass was good when kinetin was added 0.2mg/L and 0.3mg/L, individually, to MS medium containg 2mg/L 2,4-D+0.2mg/L NAA. Regeneration rate from leaf and stock callus of Korean lawngrass was 44% at MS medium adding 2,4-D 2mg/L+NAA 0.2mg/L+kinetin 0.3mg/L and 32% at the medium containing 2,4-D 2mg/L+NAA 0.2mg/L+kinetin 0.3mg/L, each and that from leaf and stock callus of penncross creeping bentgrass was 80% and 67%, each, at the medium adding 2,4-D 2mg/l+NAA 0.2mg/L+kinetin 0.3mg/L. Regeneration rate of Korean lawngrass and penneross creeping bentgrass increased by 3 to 4% and by 10 to 16%, respectively, when added $AgNO_3$ 1~2mg/L to the above-mentioned regeneration medium.

• Journal of Embryo Transfer
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• v.17 no.2
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• pp.163-168
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• 2002

The objective of this study was to investigate the clinical aspects on bovine abortion and stillbirth in Korea. Three hundred thirty eight bovine fetuses were collected from farms and submitted to the College of Veterinary Medicine, Seoul National University. Submitted fetuses were evaluated for season, parity and gestation stage on abortion during a 3 years period (June, 1999 to April, 2002). Out of four seasons, incidence of bovine abortion was significantly higher in summer than other seasons (P＜0.05) due to high temperature and humidity. After surveying of incidence of abortion according to parity, it was concentrated in low parity (1, 2 and 3 parity). However, this result was not caused by parity but because most of surveyed cow was low parity. For surveying the distribution of abortion incidence according to days of gestation, we divided the days of gestation into 3 stages including with early (0∼150 days), middle (151∼250 days) and late (251days∼term). Out of 319 aborted fetuses, incidences of abortion were significantly higher in the middle and late stage than early stage (P＜0.05). A high rate (75％) of stock farms did not vaccinate animals, therefore most of cows in Korea were found to have a high risk of becoming infected upon exposure to pathogens. Many of abortions occurred in stock farms where animals of other species were being bred. More studies will be needed to investigate possible linkages between bovine abortion and the breeding of other animal species.

• 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.

• Interdisciplinary Bio Central
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• v.2 no.4
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• pp.12.1-12.7
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• 2010

The National Bio Resource Project-Rat (NBRP-Rat) comprises the largest bank of laboratory rat (Rattus norvegicus) strains in the world. Its main focus is to develop infrastructure that will facilitate the systematic collection, preservation, and provision of rat strains. To breed effectively more than 180 rat strains in living stock, we establish the genetic control system in which a systematic set of genetic diagnoses and genetic monitoring are included. Genetic monitoring is performed by using 20 polymorphic markers. Monitoring is carried out when a living animal stock is re-established by using cryopreserved embryos or sperm or when a rat strain is first introduced to the NBRP-Rat by a depositor. Additional monitoring is then carried out on each strain every two years. Genetic diagnosis is performed largely by employing the Amp-FTA method. Protocols which detail how to perform a genetic diagnosis of 11 transgenes and 24 mutations have been made. Among the mutations, nine can be detected by simple gel electrophoresis of the PCR products, 11 by restriction enzyme treatment of the PCR products, and four by direct PCR product sequencing. Using this genetic control system, the NBRP-Rat can guarantee the genetic quality of its rat strains.

• Health Policy and Management
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• v.34 no.2
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• pp.106-119
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• 2024

Drug shortage is a persistent phenomenon that poses a public health risk worldwide and occurs due to a range of causes. The purpose of this study is to review key policies to prepare for and respond to drug shortages in selected countries, such as the United States, Canada, and some European countries in order to draw implications. This study reviewed the reports and articles derived from search engines and Google Scholar by using keywords such as drug shortage and stock-out. Over the last decade or so, the United States have strengthened requirements on advance notification for disruption and interruption of drug manufacturing, established the Inter-agency Drug Shortages Task Force to promote the communication and coordination of responses, and expedited drug regulatory processes. Similarly, Canada established the Multi-Stakeholder Steering Committee on drug shortages by involving representatives from central and local governments and private sectors. Canada also adopted a tiered approach to the communication of drug shortages based on the assessment of the severity of the shortage problem and released a detailed information guide on communication. In 2019, the joint task force between the European Medicines Agency and the Heads of Medicines Agencies issued guidelines on drug shortage communication in the European Economic Area. The countries reviewed in this paper focus on communication across different stakeholders for the monitoring of and timely response to drug shortages. The efforts to protect public health from the negative impact of the drug shortage crisis would require multi-sectorial and multi-governmental coordination and development of guidelines.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.2
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• pp.207-213
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• 2002

Fingerprint has the characteristics that do not change with time and is unique to an individual. And fingerprint identification is considered the best choice for most biometric applications because of its accuracy, speed, reliability, non-intrusive interfaces and cost-effectiveness. In this paper, we applies fingerprint Identification to web site login to raise the quality of personal identification when we use e-commerce, internet banking, stock dealings, shopping mali, etc. The system implemented in this paper consists of embedded module to carry out fingerprint identification, web server and web site. Existing system carries out fingerprint identification in the web server, but the system Implemented in this paper carries out it in client. Therefore the loads of server are reduced and the confidence of internet service is improved because login is forbidden without fingerprint identification success.

• Journal of Korean Society of Rural Planning
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• v.7 no.2 s.14
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• pp.41-53
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• 2001

A village appraisal is a study of the village, carried out by the people who live there as a basis for influencing its future. It is an exciting opportunity for a village to take a good look at itself, and it is a project in which everyone can be involved. It involves gathering factual information and the opinions of local people, so as to build up an overall picture of the village. An appraisal is a questionnaire survey carried out by and for the local community. It aims to identify local characteristics, problems, needs, threats, strengths and opportunities. It is a means of taking stock of the community and of creating a sound foundation of awareness and understanding on which to base future community action. Over the past 30 years more than 2,000 village appraisals have been undertaken in rural Britain. This research examined 48 village appraisals which had been carried out in England between 1985 and 1999. The suggested strengths and weaknesses of the village appraisals are: the target of the whole population in an area; the wide-ranging in its coverage of issues; well linked to a county-wide support agency; a good tool for identifying needs and wants, and local priorities; a good tool of local democracy and of increasing self-confidence in individuals and the whole community; not an exhaustive survey; very labour intensive; too little coverage of issues relating to the local economy; the lack of any input by professional planners and so forth.