• Review of Culture and Economy
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• v.17 no.2
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• pp.3-28
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• 2014

The characteristics of performing arts differ from those of utilitarian goods in terms of economics. Factors other than price need to be considered to understand the demand for performing arts. Audience surveys as well as econometric demand studies have confirmed that socio-economic factors such as age, income, employment, and education are major determinants of the demand for performing arts. This study focused on the attributes of concerts rather than consumer characteristics to determine the concerts audiences select in terms of transaction cost. Genre, price, internet search trends, and the purpose of performance as well as price are tested as determinants of demand by using the data set for a major concert hall in Seoul. Genre and the specific purpose of concerts influence the demand for concerts. Internet search trends of the performer are used as indicators of popularity and information exposure, which are positively correlated with demand. This result supports the hypothesis that larger audiences would attend concerts that require lower information search costs. To note, price has a positive effect on demand in the higher price range, which means that concerts at higher prices attract larger audiences, whereas normal goods have a negative slope in the demand curve. This result can be explained by the hypothesis that consumers use price as an indicator of the quality expected of a concert. Transaction cost for selecting classical concerts thus forms an inverse-U shape curve against ticket price. These results provide some explanation of why audiences of classical music choose to attend concerts at high ticket prices while offering evidence in favor of the hypothesis that performing arts are selected in a social context.

• Journal of the Korean Data and Information Science Society
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• v.18 no.2
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• pp.289-300
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• 2007

The stock return is changed by factors of inside and outside or is changed by factor of market system. But most studies have not considered the changes of stock return distribution when estimate the VaR. Such study may lead us to wrong conclusion. In this paper we calculate the VaR of price-to-earnings ratios by the distribution that have considered the change point and used transformation to satisfy normal distribution.

• Korean journal of food and cookery science
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• v.26 no.4
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• pp.450-457
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• 2010

A survey was conducted to determine the relationship between BMI and the dining out behaviors of 316 university students in Seoul area for May and September, 2006. The subjects included 114 males and 202 females. General characteristics and BMI determined that of the students 56 (17.7%) were underweight, 222 (70.3%)were normal, 23 (7.3%) were overweight, and 15 (4.7%) were obese. There were differences in BMI according to age, sex, and major. Students majoring in natural science and engineering were 58.3% and 51% normal weight, respectively, and the next most common weight class was overweight. The non smoking group showed had primarily normal weight subjects followed by underweight-subjects, but the smoking group had primarily normal weight subjects followed by overweight subjects (P<0.001). The frequency of dining out for breakfast significantly correlated with BMI (P<0.05). The group that frequently dined out for breakfast were primarily of normal weight followed by overweight subjects, but the group that rarely dined out for breakfast were primarily of normal weight followed by underweight subjects(21.4%). Groups whose criteria for selecting dining out meals were flavor and price showed a higher percentage of underweight subjects than other groups. The group whose motivations for choosing dining out meals were convenience and habit showed a higher percentage underweight subjects than other motivations. The group that selected the Western food menu for dining out showed a higher percentage of underweight subjects than other food menu groups. And, the groups that selected Japanese and Korean food were primarily of normal weight followed by underweight subjects, but the result was not significant.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.8
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• pp.831-838
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• 2009

This paper proposes an IR (infrared) LED (Light Emitting Diode)-based tactile fingertip sensor that can independently measure the normal and tangential force between the hand and an object. The proposed IR LED-based tactile sensor has several advantages over other technologies, including a low price, small size, and good sensitivity. The design of the first prototype is described and some experiments are conducted to show output characteristics of the proposed sensor. Furthemore, the effectiveness of the proposed sensor is demonstrated through anti-slip control in a multifunction myoelectric hand, called the KNU Hand, which includes several novel mechanisms for improved grasping capabilities. The experimental results show that slippage was avoided by simple force control using feedback on the normal and tangential force from the proposed sensor. Thus, grasping force control was achieved without any slippage or damage to the object.

• The Korean Journal of Financial Management
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• v.24 no.2
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• pp.41-79
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• 2007

This study examines the expiration-day effects of stock index futures and options in the Korean stock market. The so-called 'expiration-day effects', which are the abnormal stock price movements on derivatives expiration days, arise mainly from cash settlement. Index arbitragers have to bear the risk of their positions unless they liquidate their index stocks on the expiration day. If many arbitragers execute large buy or sell orders on the expiration day, abnormal trading volumes are likely to be observed. If a lot of arbitragers unwind positions in the same direction, temporary trading imbalances induce abnormal stock market volatility. By contrast, if some information arrives at market, the abnormal trading activity must be considered a normal process of price discovery. Stoll and Whaley(1987) investigated the aggregate price and volume effects of the S&P 500 index on the expiration day. In a related study, Stoll and Whaley(1990) found a similarity between the price behavior of stocks that are subject to program trading and of the stocks that are not. Thus far, there have been few studies about the expiration-day effects in the Korean stock market. While previous Korean studies use the KOSPI 200 index data, we analyze the price and trading volume behavior of individual stocks as well as the index. Analyzing individual stocks is important for two reasons. First, stock index is a market average. Consequently, it cannot reflect the behavior of many individual stocks. For example, if the expiration-day effects are mainly related to a specific group, it cannot be said that the expiration of derivatives itself destabilizes the stock market. Analyzing individual stocks enables us to investigate the scope of the expiration-day effects. Second, we can find the relationship between the firm characteristics and the expiration-day effects. For example, if the expiration-day effects exist in large stocks not belonging to the KOSPI 200 index, program trading may not be related to the expiration-day effects. The examination of individual stocks has led us to the cause of the expiration-day effects. Using the intraday data during the period May 3, 1996 through December 30, 2003, we first examine the price and volume effects of the KOSPI 200 and NON-KOSPI 200 index following the Stoll and Whaley(1987) methodology. We calculate the NON-KOSPI 200 index by using the returns and market capitalization of the KOSPI and KOSPI 200 index. In individual stocks, we divide KOSPI 200 stocks by size into three groups and match NON-KOSPI 200 stocks with KOSPI 200 stocks having the closest firm characteristics. We compare KOSPI 200 stocks with NON-KOSPI 200 stocks. To test whether the expiration-day effects are related to order imbalances or new information, we check price reversals on the next day. Finally, we perform a cross-sectional regression analysis to elaborate on the impact of the firm characteristics on price reversals. The main results seem to support the expiration-day effects, especially on stock index futures expiration days. The price behavior of stocks that are subject to program trading is shown to have price effects, abnormal return volatility, and large volumes during the last half hour of trading on the expiration day. Return reversals are also found in the KOSPI 200 index and stocks. However, there is no evidence of abnormal trading volume, or price reversals in the NON-KOSPI 200 index and stocks. The expiration-day effects are proportional to the size of stocks and the nearness to the settlement time. Since program trading is often said to be concentrated in high capitalization stocks, these results imply that the expiration-day effects seem to be associated with program trading and the settlement price determination procedure. In summary, the expiration-day effects in the Korean stock market do not exist in all stocks, but in large capitalization stocks belonging to the KOSPI 200 index. Additionally, the expiration-day effects in the Korean stock market are generally due, not to information, but to trading imbalances.

• Journal of Intelligence and Information Systems
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• v.20 no.3
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• pp.93-108
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• 2014

To support business decision making, interests and efforts to analyze and use transaction data in different perspectives are increasing. Such efforts are not only limited to customer management or marketing, but also used for monitoring and detecting fraud transactions. Fraud transactions are evolving into various patterns by taking advantage of information technology. To reflect the evolution of fraud transactions, there are many efforts on fraud detection methods and advanced application systems in order to improve the accuracy and ease of fraud detection. As a case of fraud detection, this study aims to provide effective fraud detection methods for auction exception agricultural products in the largest Korean agricultural wholesale market. Auction exception products policy exists to complement auction-based trades in agricultural wholesale market. That is, most trades on agricultural products are performed by auction; however, specific products are assigned as auction exception products when total volumes of products are relatively small, the number of wholesalers is small, or there are difficulties for wholesalers to purchase the products. However, auction exception products policy makes several problems on fairness and transparency of transaction, which requires help of fraud detection. In this study, to generate fraud detection rules, real huge agricultural products trade transaction data from 2008 to 2010 in the market are analyzed, which increase more than 1 million transactions and 1 billion US dollar in transaction volume. Agricultural transaction data has unique characteristics such as frequent changes in supply volumes and turbulent time-dependent changes in price. Since this was the first trial to identify fraud transactions in this domain, there was no training data set for supervised learning. So, fraud detection rules are generated using outlier detection approach. We assume that outlier transactions have more possibility of fraud transactions than normal transactions. The outlier transactions are identified to compare daily average unit price, weekly average unit price, and quarterly average unit price of product items. Also quarterly averages unit price of product items of the specific wholesalers are used to identify outlier transactions. The reliability of generated fraud detection rules are confirmed by domain experts. To determine whether a transaction is fraudulent or not, normal distribution and normalized Z-value concept are applied. That is, a unit price of a transaction is transformed to Z-value to calculate the occurrence probability when we approximate the distribution of unit prices to normal distribution. The modified Z-value of the unit price in the transaction is used rather than using the original Z-value of it. The reason is that in the case of auction exception agricultural products, Z-values are influenced by outlier fraud transactions themselves because the number of wholesalers is small. The modified Z-values are called Self-Eliminated Z-scores because they are calculated excluding the unit price of the specific transaction which is subject to check whether it is fraud transaction or not. To show the usefulness of the proposed approach, a prototype of fraud transaction detection system is developed using Delphi. The system consists of five main menus and related submenus. First functionalities of the system is to import transaction databases. Next important functions are to set up fraud detection parameters. By changing fraud detection parameters, system users can control the number of potential fraud transactions. Execution functions provide fraud detection results which are found based on fraud detection parameters. The potential fraud transactions can be viewed on screen or exported as files. The study is an initial trial to identify fraud transactions in Auction Exception Agricultural Products. There are still many remained research topics of the issue. First, the scope of analysis data was limited due to the availability of data. It is necessary to include more data on transactions, wholesalers, and producers to detect fraud transactions more accurately. Next, we need to extend the scope of fraud transaction detection to fishery products. Also there are many possibilities to apply different data mining techniques for fraud detection. For example, time series approach is a potential technique to apply the problem. Even though outlier transactions are detected based on unit prices of transactions, however it is possible to derive fraud detection rules based on transaction volumes.

• The Korean Journal of Physiology
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• v.6 no.2
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• pp.57-63
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• 1972

In an attempt to better understand the radioprotective effect of reduced glutathione(GSH), and to observe a possible radioprotective effect of Ginseng extract, whole body X-irradiation of 1,200 r was administered to the mouse either independently or immediately following the injection of GSH or Ginseng extract to the mouse intraperitoneally. The non-protein sulfhydryl (NP-SH) and non-protein disulfide (NP-SS) levels of the liver, and NP-SH level of NP-SH of the blood of the mouse were measured at 30, 60 and 120 minutes, and results were compared with the normal. The results thus obtained are summarized as follows; 1) The normal values of NP-SH and NP-SS of the mouse liver were $5.90{\pm}0.46\;{\mu}\;mol/gm\;wet\;wt.,\;and\;3.02{\pm}0.42\;{\mu}\;mol/ml$ wet wt., respectively, and the normal value of NP-SH of NP-SH of the mouse blood was $3.98{\pm}1.29\;{\mu}\;mol/ml$ 2) The injection of both GSH and Ginseng extract produced the highest values of NP-SH in the liver at 30 minutes, but a gradual decrease to the normal was observed thereafter. When X-irradiation alone was applied, the liver NP-SH value was lower than the normal at 60 minutes post-irradiation and thereafter. When Ginseng extract was injected immediately prior to X-irradiation, the liver NP-SH was lower than the normal throughout the experiment with the lowest value at 60 minutes. However, the combination of GSH and X-irradiation produced higher than the normal values throughout the entire experiment. 3) The liver NP-SS value was most significantly elevated at 30 minutes after the injection of GSH, hut the recovery to the normal was observed thereafter. The injection of Ginseng extract produced slightly higher liver NP-SS values at 30 and 60 minutes, but the value at 120 minutes was similar to the normal. The single application of X-irradiation resulted in the lower then normal liver NP-SS values throughout the entire experiment. When GSH was injected price to X-irradiation, the liver NP-SS values were higher than the normal at 30 and 60 minutes followed b the recovery to the normal at 120 minutes. The combination of Ginseng extract and X-irradiation showed generally lower liver NP-SS values throughout the experiment. 4) The blood NP-SH showed the higher than the normal values in all the experimental groups except when GSH was injected prior to X-irradiation alone produced e significantly elevated blood NP-SS value at 30 minutes post-irradiation.

• Journal of the Korean Data and Information Science Society
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• v.28 no.2
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• pp.251-260
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• 2017

The option pricing of Black와 Scholes (1973) and Merton (1973) has been widely reported to fail to reflect the time varying volatility of financial time series in many real applications. For example, Duan (1995) proposed GARCH option pricing method through Monte Carlo simulation. However, financial time series is known to follow a fat-tailed and leptokurtic probability distribution, which is not explained by Duan (1995). In this paper, in order to overcome such defects, we proposed the option pricing method based on GARCH models with normal mixture errors. According to the analysis of KOSPI200 option price data, the option pricing based on GARCH models with normal mixture errors outperformed the option pricing based on GARCH models with normal errors in the unstable period with high volatility.

• Korean journal of food and cookery science
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• v.12 no.1
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• pp.13-19
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• 1996

This study was to investigate dining behaviours of 420 businessmen living in urban regions (Taegu, Gumi, Young-Chon and Chang-Won) in Kyungbuk and Kyungnam. This survey was carried out by questionnaires. The results were summarized as follows; Among all respondents, dining out once a day was most frequent. Education (p<.05), age (p<.001) and marital status (p<.001) were significant. Socialization was the most frequent reason for dining out. In the choice of food, Korean food was the most frequent (68.1%). Taste (41.4%) was the most frequently cited reason for food selection followed by variety of food (18.8%) and price (8.8%). The respondents favorite foods were: Korean food; Doen Jug Soup (31.9%); Western food; Pork Cutlet (47.6%); Chinese food; Gan Ja Jang (31.2%); Flour-bared food; Kal Gook Su (55.4%), and Fast food; Ramen (26.4%). The most frequent choices of where to eat were the company cafeteria for lunch and Korean restaurant for dinner (p<.001). Responses to inquires concerning sanitation, facilities and service were mostly "normal". They wanted lower price (30.5%), a more variable menu (24.8%), and more vegetables and fruits (18.1%) in restaurant and cafeteria food. Age (p<.05) and marital status (p＜.001) were statistically significant.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.2
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• pp.291-297
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• 2010

A system called demand response programs (DRP) is being introduced among various countries owing to the lack of new generation capacity and the higher fuel generation cost. It is a program which provides for the end-users to select their consumption of electricity by recognizing the value of their consumption in real time. That is, Demand Response can be defined as the changes in electric usage by end-use customers from their normal consumption patterns in response to changes in the price of electricity or other signals. It is expected that the effects of DRP are preventing price spike, improving supply reliability and social welfare and increasing option of customers. Considering the customer's thermal comfort zone, this paper determines the most profitable combination of optimal incentives and amounts of load reduction for a retailer to maximize profits according to predicted outdoor temperatures while implementing DRP.