• Title/Summary/Keyword: Trade Frequency

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Present Status of Non-Native Amphibians and Reptiles Traded in Korean Online Pet Shop (한국 온라인 펫샵에서 거래되는 외래 양서파충류 현황)

  • Koo, Kyo Soung;Park, Hye Rin;Choi, Jae Hyeok;Sung, Ha Cheol
    • Korean Journal of Environment and Ecology
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    • v.34 no.2
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    • pp.106-114
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    • 2020
  • The development of transportation and the expansion of the pet market has become the main causes of the increase in the cross-border migration of non-native species. Moreover, recent sales over the Internet were a factor that has promoted pet trades. While the import of non-native species has been steadily increasing in the Republic of Korea, it is not clear how these imported species are traded and how large the trade is. Considering that most of the non-native species found in the wild are the results of release by humans understanding the present situation of pet trades can identify potential non-native species that can enter the wild. This study surveyed the number of species, frequency, and prices of non-native amphibians and reptiles sold in 25 online pet shops from January 22 to February 10, 2019. The results of the survey showed that a total of 677 species of non-native amphibians and reptiles were sold, and the Squamata group accounted for the largest part of them at 65.4% (443 species). The number of non-native amphibians and reptiles sold in online pet shops in 2019 was 2.1 times larger than the 325 species officially imported in 2015. The non-native amphibians and reptiles sold in most pet shops were Litoria caerulea (21 shops) and Correlophus ciliatus (24 shops). The lowest price for non-native amphibians and reptiles was 3,000 won, and the highest price was 100 million won for Rhacodactylus leachianus of Squamata. Among the non-native amphibians and reptiles sold in online pet shops, 11 species were found in the wild and were sold at relatively low prices. We confirmed that Mauremys reevesii, an endangered species class II and natural monument no. 453, and American bullfrogs (albino), an ecosystem disturbing species, were being sold in online pet shops. Moreover, 21.6% of the 677 non-native amphibians and reptiles sold in online pet shops were species designated as CITES. The results of this study can be the important reference data for understanding the status of non-native amphibians and reptiles that are imported and sold in Korea and evaluating and predicting the potential for them to enter the wild.

Estimation of GARCH Models and Performance Analysis of Volatility Trading System using Support Vector Regression (Support Vector Regression을 이용한 GARCH 모형의 추정과 투자전략의 성과분석)

  • Kim, Sun Woong;Choi, Heung Sik
    • Journal of Intelligence and Information Systems
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    • v.23 no.2
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    • pp.107-122
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    • 2017
  • Volatility in the stock market returns is a measure of investment risk. It plays a central role in portfolio optimization, asset pricing and risk management as well as most theoretical financial models. Engle(1982) presented a pioneering paper on the stock market volatility that explains the time-variant characteristics embedded in the stock market return volatility. His model, Autoregressive Conditional Heteroscedasticity (ARCH), was generalized by Bollerslev(1986) as GARCH models. Empirical studies have shown that GARCH models describes well the fat-tailed return distributions and volatility clustering phenomenon appearing in stock prices. The parameters of the GARCH models are generally estimated by the maximum likelihood estimation (MLE) based on the standard normal density. But, since 1987 Black Monday, the stock market prices have become very complex and shown a lot of noisy terms. Recent studies start to apply artificial intelligent approach in estimating the GARCH parameters as a substitute for the MLE. The paper presents SVR-based GARCH process and compares with MLE-based GARCH process to estimate the parameters of GARCH models which are known to well forecast stock market volatility. Kernel functions used in SVR estimation process are linear, polynomial and radial. We analyzed the suggested models with KOSPI 200 Index. This index is constituted by 200 blue chip stocks listed in the Korea Exchange. We sampled KOSPI 200 daily closing values from 2010 to 2015. Sample observations are 1487 days. We used 1187 days to train the suggested GARCH models and the remaining 300 days were used as testing data. First, symmetric and asymmetric GARCH models are estimated by MLE. We forecasted KOSPI 200 Index return volatility and the statistical metric MSE shows better results for the asymmetric GARCH models such as E-GARCH or GJR-GARCH. This is consistent with the documented non-normal return distribution characteristics with fat-tail and leptokurtosis. Compared with MLE estimation process, SVR-based GARCH models outperform the MLE methodology in KOSPI 200 Index return volatility forecasting. Polynomial kernel function shows exceptionally lower forecasting accuracy. We suggested Intelligent Volatility Trading System (IVTS) that utilizes the forecasted volatility results. IVTS entry rules are as follows. If forecasted tomorrow volatility will increase then buy volatility today. If forecasted tomorrow volatility will decrease then sell volatility today. If forecasted volatility direction does not change we hold the existing buy or sell positions. IVTS is assumed to buy and sell historical volatility values. This is somewhat unreal because we cannot trade historical volatility values themselves. But our simulation results are meaningful since the Korea Exchange introduced volatility futures contract that traders can trade since November 2014. The trading systems with SVR-based GARCH models show higher returns than MLE-based GARCH in the testing period. And trading profitable percentages of MLE-based GARCH IVTS models range from 47.5% to 50.0%, trading profitable percentages of SVR-based GARCH IVTS models range from 51.8% to 59.7%. MLE-based symmetric S-GARCH shows +150.2% return and SVR-based symmetric S-GARCH shows +526.4% return. MLE-based asymmetric E-GARCH shows -72% return and SVR-based asymmetric E-GARCH shows +245.6% return. MLE-based asymmetric GJR-GARCH shows -98.7% return and SVR-based asymmetric GJR-GARCH shows +126.3% return. Linear kernel function shows higher trading returns than radial kernel function. Best performance of SVR-based IVTS is +526.4% and that of MLE-based IVTS is +150.2%. SVR-based GARCH IVTS shows higher trading frequency. This study has some limitations. Our models are solely based on SVR. Other artificial intelligence models are needed to search for better performance. We do not consider costs incurred in the trading process including brokerage commissions and slippage costs. IVTS trading performance is unreal since we use historical volatility values as trading objects. The exact forecasting of stock market volatility is essential in the real trading as well as asset pricing models. Further studies on other machine learning-based GARCH models can give better information for the stock market investors.

Analysis of Research Trends in Journal of Distribution Science (유통과학연구의 연구 동향 분석 : 창간호부터 제8권 제3호까지를 중심으로)

  • Kim, Young-Min;Kim, Young-Ei;Youn, Myoung-Kil
    • Journal of Distribution Science
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    • v.8 no.4
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    • pp.5-15
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    • 2010
  • This study investigated research trends of JDS that KODISA published and gave implications to elevate quality of scholarly journals. In other words, the study classified scientific system of distribution area to investigate research trends and to compare it with other scholarly journals of distribution and to give implications for higher level of JDS. KODISA published JDS Vol.1 No.1 for the first time in 1999 followed by Vol.8 No.3 in September 2010 to show 109 theses in total. KODISA investigated subjects, research institutions, number of participants, methodology, frequency of theses in both the Korean language and English, frequency of participation of not only the Koreans but also foreigners and use of references, etc. And, the study investigated JDR of KODIA, JKDM(The Journal of Korean Distribution & Management) and JDA that researched distribution, so that it found out development ways. To investigate research trends of JDS that KODISA publishes, main category was made based on the national science and technology standard classification system of MEST (Ministry Of Education, Science And Technology), table of classification of research areas of NRF(National Research Foundation of Korea), research classification system of both KOREADIMA and KLRA(Korea Logistics Research Association) and distribution science and others that KODISA is looking for, and distribution economy area was divided into general distribution, distribution economy, distribution, distribution information and others, and distribution management was divided into distribution management, marketing, MD and purchasing, consumer behavior and others. The findings were as follow: Firstly, main category occupied 47 theses (43.1%) of distribution economy and 62 theses (56.9%) of distribution management among 109 theses in total. Active research area of distribution economy consisted of 14 theses (12.8%) of distribution information and 9 theses (8.3%) of distribution economy to research distribution as well as distribution information positively every year. The distribution management consisted of 25 theses (22.9%) of distribution management and 20 theses (18.3%) of marketing, These days, research on distribution management, marketing, distribution, distribution information and others is increasing. Secondly, researchers published theses as follow: 55 theses (50.5%) by professor by himself or herself, 12 theses (11.0%) of joint research by professors and businesses, Professors/students published 9 theses (8.3%) followed by 5 theses (4.6%) of researchers, 5 theses (4.6%) of businesses, 4 theses (3.7%) of professors, researchers and businesses and 2 theses (1.8%) of students. Professors published theses less, while businesses, research institutions and graduate school students did more continuously. The number of researchers occupied single researcher (43 theses, 39.5%), two researchers (42 theses, 38.5%) and three researchers or more (24 theses, 22.0%). Thirdly, professors published theses the most at most of areas. Researchers of main category of distribution economy consisted of professors (25 theses, 53.2%), professors and businesses (7 theses, 14.9%), professors and businesses (7 theses, 14.9%), professors and researchers (6 theses, 12.8%) and professors and students (3 theses, 6.3%). And, researchers of main category of distribution management consisted of professors (30 theses, 48.4%), professors and businesses (10 theses, 16.1%), and professors and researchers as well as professors and students (6 theses, 9.7%). Researchers of distribution management consisted of professors, professors and businesses, professors and researchers, researchers and businesses, etc to have various types. Professors mainly researched marketing, MD and purchasing, and consumer behavior, etc to demand active participation of businesses and researchers. Fourthly, research methodology was: Literature research occupied 45 theses (41.3%) the most followed by empirical research based on questionnaire survey (44 theses, 40.4%). General distribution, distribution economy, distribution and distribution management, etc mostly adopted literature research, while marketing did empirical research based on questionnaire survey the most. Fifthly, theses in the Korean language occupied 92.7% (101 theses), while those in English did 7.3% (8 theses). No more than one thesis in English was published until 2006, and 7 theses (11.9%) were published after 2007 to increase. The theses in English were published more to be affirmative. Foreigner researcher published one thesis (0.9%) and both Korean researchers and foreigner researchers jointly published two theses (1.8%) to have very much low participation of foreigner researchers. Sixthly, one thesis of JDS had 27.5 references in average that consisted of 11.1 local references and 16.4 foreign references. And, cited times was 0.4 thesis in average to be low. The distribution economy cited 24.2 references in average (9.4 local references and 14.8 foreign references and JDS had 0.6 cited reference. The distribution management had 30.0 references in average (12.1 local references and 17.9 foreign references) and had 0.3 reference of JDS itself. Seventhly, similar type of scholarly journal had theses in the Korean language and English: JDR( Journal of Distribution Research) of KODIA(Korea Distribution Association) published 92 theses in the Korean language (96.8%) and 3 theses in English (3.2%), that is to say, 95 theses in total. JKDM of KOREADIMA published 132 theses in total that consisted of 93 theses in the Korean language (70.5%) and 39 theses in English (29.5%). Since 2008, JKDM has published scholarly journal in English one time every year. JDS published 52 theses in the Korean language (88.1%) and 7 theses in English (11.9%), that is to say, 59 theses in total. Sixthly, similar type of scholarly journals and research methodology were: JDR's research methodology had 65 empirical researches based on questionnaire survey (68.4%), followed by 17 literature researches (17.9%) and 11 quantitative analyses (11.6%). JKDM made use of various kinds of research methodologies to have 60 questionnaire surveys (45.5%), followed by 40 literature researches (30.3%), 21 quantitative analyses (15.9%), 6 system analyses (4.5%) and 5 case studies (3.8%). And, JDS made use of 30 questionnaire surveys (50.8%), followed by 15 literature researches (25.4%), 7 case studies (11.9%) and 6 quantitative analyses (10.2%). Ninthly, similar types of scholarly journals and Korean researchers and foreigner researchers were: JDR published 93 theses (97.8%) by Korean researchers except for 1 thesis by foreigner researcher and 1 thesis by joint research of the Korean researchers and foreigner researchers. And, JKDM had no foreigner research and 13 theses (9.8%) by joint research of the Korean researchers and foreigner researchers to have more foreigner researchers as well as researchers in foreign countries than similar types of scholarly journals had. And, JDS published 56 theses (94.9%) of the Korean researchers, one thesis (1.7%) of foreigner researcher only, and 2 theses (3.4%) of joint research of both the Koreans and foreigners. Tenthly, similar type of scholarly journals and reference had citation: JDR had 42.5 literatures in average that consisted of 10.9 local literatures (25.7%) and 31.6 foreign literatures (74.3%), and cited times accounted for 1.1 thesis to decrease. JKDM cited 10.5 Korean literatures (36.3%) and 18.4 foreign literatures (63.7%), and number of self-cited literature was no more than 1.1. Number of cited times accounted for 2.9 literatures in 2008 and then decreased continuously since then. JDS cited 26,8 references in average that consisted of 10.9 local references (40.7%) and 15.9 foreign references (59.3%), and number of self-cited accounted for 0.2 reference until 2009, and it increased to be 2.1 references in 2010. The author gives implications based on JDS research trends and investigation on similar type of scholarly journals as follow: Firstly, JDS shall actively invite foreign contributors to prepare for SSCI. Secondly, ratio of theses in English shall increase greatly. Thirdly, various kinds of research methodology shall be accepted to elevate quality of scholarly journals. Fourthly, to increase cited times, Google and other web retrievals shall be reinforced to supply scholarly journals to foreign countries more. Local scholarly journals can be worldwide scholarly journal enough to be acknowledged even in foreign countries by improving the implications above.

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A Study on Modernization of International Conventions Relating to Aviation Security and Implementation of National Legislation (항공보안 관련 국제협약의 현대화와 국내입법의 이행 연구)

  • Lee, Kang-Bin
    • The Korean Journal of Air & Space Law and Policy
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    • v.30 no.2
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    • pp.201-248
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    • 2015
  • In Korea the number of unlawful interference act on board aircrafts has been increased continuously according to the growth of aviation demand, and there were 55 incidents in 2000, followed by 354 incidents in 2014, and an average of 211 incidents a year over the past five years. In 1963, a number of states adopted the Convention on Offences and Certain Other Acts Committed on Board Aircraft (the Tokyo Convention 1963) as the first worldwide international legal instrument on aviation security. The Tokyo Convention took effect in 1969 and, shortly afterward, in 1970 the Convention for the Suppression of Unlawful Seizure of Aircraft(the Hague Convention 1970) was adopted, and the Convention for the Suppression of Unlawful Acts Against the Safety of Civil Aviation(the Montreal Convention 1971) was adopted in 1971. After 9/11 incidents in 2001, to amend and supplement the Montreal Convention 1971, the Convention on the Suppression of Unlawful Acts Relating to International Civil Aviation(the Beijing Convention 2010) was adopted in 2010, and to supplement the Hague Convention 1970, the Protocol Supplementary to the Convention for the Suppression of Unlawful Seizure of Aircraft(the Beijing Protocol 2010) was adopted in 2010. Since then, in response to increased cases of unruly behavior on board aircrafts which escalated in both severity and frequency,, the Montreal Protocol which is seen as an amendment to the Convention on Offences and Certain Other Acts Committed on Board Aircraft(the Tokyo Convention 1963) was adopted in 2014. Korea ratified the Tokyo Convention 1963, the Hague Convention 1970, the Montreal Convention 1971, the Montreal Supplementary Protocol 1988, and the Convention on the Marking of Plastic Explosive 1991 which have proven to be effective. Under the Tokyo Convention ratified in 1970, Korea further enacted the Aircraft Navigation Safety Act in 1974, as well as the Aviation Safety and Security Act that replaced the Aircraft Navigation Safety Act in August 2002. Meanwhile, the title of the Aviation Safety and Security Act was changed to the Aviation Security Act in April 2014. The Aviation Security Act is essentially an implementing legislation of the Tokyo Convention and Hague Convention. Also the language of the Aviation Security Act is generally broader than the unruly and disruptive behavior in Sections 1-3 of the model legislation in ICAO Circular 288. The Aviation Security Act has reflected the considerable parts of the implementation of national legislation under the Beijing Convention and Beijing Protocol 2010, and the Montreal Protocol 2014 that are the modernized international conventions relating to aviation security. However, in future, when these international conventions would come into effect and Korea would ratify them, the national legislation that should be amended or provided newly in the Aviation Security Act are as followings : The jurisdiction, the definition of 'in flight', the immunity from the actions against the aircraft commander, etc., the compulsory delivery of the offender by the aircraft commander, etc., the strengthening of penalty on the person breaking the law, the enlargement of application to the accomplice, and the observance of international convention. Among them, particularly the Korean legislation is silent on the scope of the jurisdiction. Therefore, in order for jurisdiction to be extended to the extra-territorial cases of unruly and disruptive offences, it is desirable that either the Aviation Security Act or the general Crime Codes should be revised. In conclusion, in order to meet the intelligent and diverse aviation threats, the Korean government should review closely the contents of international conventions relating to aviation security and the current ratification status of international conventions by each state, and make effort to improve the legislation relating to aviation security and the aviation security system for the ratification of international conventions and the implementation of national legislation under international conventions.

Word-of-Mouth Effect for Online Sales of K-Beauty Products: Centered on China SINA Weibo and Meipai (K-Beauty 구전효과가 온라인 매출액에 미치는 영향: 중국 SINA Weibo와 Meipai 중심으로)

  • Liu, Meina;Lim, Gyoo Gun
    • Journal of Intelligence and Information Systems
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    • v.25 no.1
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    • pp.197-218
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    • 2019
  • In addition to economic growth and national income increase, China is also experiencing rapid growth in consumption of cosmetics. About 67% of the total trade volume of Chinese cosmetics is made by e-commerce and especially K-Beauty products, which are Korean cosmetics are very popular. According to previous studies, 80% of consumer goods such as cosmetics are affected by the word of mouth information, searching the product information before purchase. Mostly, consumers acquire information related to cosmetics through comments made by other consumers on SNS such as SINA Weibo and Wechat, and recently they also use information about beauty related video channels. Most of the previous online word-of-mouth researches were mainly focused on media itself such as Facebook, Twitter, and blogs. However, the informational characteristics and the expression forms are also diverse. Typical types are text, picture, and video. This study focused on these types. We analyze the unstructured data of SINA Weibo, the SNS representative platform of China, and Meipai, the video platform, and analyze the impact of K-Beauty brand sales by dividing online word-of-mouth information with quantity and direction information. We analyzed about 330,000 data from Meipai, and 110,000 data from SINA Weibo and analyzed the basic properties of cosmetics. As a result of analysis, the amount of online word-of-mouth information has a positive effect on the sales of cosmetics irrespective of the type of media. However, the online videos showed higher impacts than the pictures and texts. Therefore, it is more effective for companies to carry out advertising and promotional activities in parallel with the existing SNS as well as video related information. It is understood that it is important to generate the frequency of exposure irrespective of media type. The positiveness of the video media was significant but the positiveness of the picture and text media was not significant. Due to the nature of information types, the amount of information in video media is more than that in text-oriented media, and video-related channels are emerging all over the world. In particular, China has made a number of video platforms in recent years and has enjoyed popularity among teenagers and thirties. As a result, existing SNS users are being dispersed to video media. We also analyzed the effect of online type of information on the online cosmetics sales by dividing the product type of cosmetics into basic cosmetics and color cosmetics. As a result, basic cosmetics had a positive effect on the sales according to the number of online videos and it was affected by the negative information of the videos. In the case of basic cosmetics, effects or characteristics do not appear immediately like color cosmetics, so information such as changes after use is often transmitted over a period of time. Therefore, it is important for companies to move more quickly to issues generated from video media. Color cosmetics are largely influenced by negative oral statements and sensitive to picture and text-oriented media. Information such as picture and text has the advantage and disadvantage that the process of making it can be made easier than video. Therefore, complaints and opinions are generally expressed in SNS quickly and immediately. Finally, we analyzed how product diversity affects sales according to online word of mouth information type. As a result of the analysis, it can be confirmed that when a variety of products are introduced in a video channel, they have a positive effect on online cosmetics sales. The significance of this study in the theoretical aspect is that, as in the previous studies, online sales have basically proved that K-Beauty cosmetics are also influenced by word-of-mouth. However this study focused on media types and both media have a positive impact on sales, as in previous studies, but it has been proven that video is more informative and influencing than text, depending on media abundance. In addition, according to the existing research on information direction, it is said that the negative influence has more influence, but in the basic study, the correlation is not significant, but the effect of negation in the case of color cosmetics is large. In the case of temporal fashion products such as color cosmetics, fast oral effect is influenced. In practical terms, it is expected that it will be helpful to use advertising strategies on the sales and advertising strategy of K-Beauty cosmetics in China by distinguishing basic and color cosmetics. In addition, it can be said that it recognized the importance of a video advertising strategy such as YouTube and one-person media. The results of this study can be used as basic data for analyzing the big data in understanding the Chinese cosmetics market and establishing appropriate strategies and marketing utilization of related companies.