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The Relationship between Internet Search Volumes and Stock Price Changes: An Empirical Study on KOSDAQ Market (개별 기업에 대한 인터넷 검색량과 주가변동성의 관계: 국내 코스닥시장에서의 산업별 실증분석)

  • Jeon, Saemi;Chung, Yeojin;Lee, Dongyoup
    • Journal of Intelligence and Information Systems
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    • v.22 no.2
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    • pp.81-96
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    • 2016
  • As the internet has become widespread and easy to access everywhere, it is common for people to search information via online search engines such as Google and Naver in everyday life. Recent studies have used online search volume of specific keyword as a measure of the internet users' attention in order to predict disease outbreaks such as flu and cancer, an unemployment rate, and an index of a nation's economic condition, and etc. For stock traders, web search is also one of major information resources to obtain data about individual stock items. Therefore, search volume of a stock item can reflect the amount of investors' attention on it. The investor attention has been regarded as a crucial factor influencing on stock price but it has been measured by indirect proxies such as market capitalization, trading volume, advertising expense, and etc. It has been theoretically and empirically proved that an increase of investors' attention on a stock item brings temporary increase of the stock price and the price recovers in the long run. Recent development of internet environment enables to measure the investor attention directly by the internet search volume of individual stock item, which has been used to show the attention-induced price pressure. Previous studies focus mainly on Dow Jones and NASDAQ market in the United States. In this paper, we investigate the relationship between the individual investors' attention measured by the internet search volumes and stock price changes of individual stock items in the KOSDAQ market in Korea, where the proportion of the trades by individual investors are about 90% of the total. In addition, we examine the difference between industries in the influence of investors' attention on stock return. The internet search volume of stocks were gathered from "Naver Trend" service weekly between January 2007 and June 2015. The regression model with the error term with AR(1) covariance structure is used to analyze the data since the weekly prices in a stock item are systematically correlated. The market capitalization, trading volume, the increment of trading volume, and the month in which each trade occurs are included in the model as control variables. The fitted model shows that an abnormal increase of search volume of a stock item has a positive influence on the stock return and the amount of the influence varies among the industry. The stock items in IT software, construction, and distribution industries have shown to be more influenced by the abnormally large internet search volume than the average across the industries. On the other hand, the stock items in IT hardware, manufacturing, entertainment, finance, and communication industries are less influenced by the abnormal search volume than the average. In order to verify price pressure caused by investors' attention in KOSDAQ, the stock return of the current week is modelled using the abnormal search volume observed one to four weeks ahead. On average, the abnormally large increment of the search volume increased the stock return of the current week and one week later, and it decreased the stock return in two and three weeks later. There is no significant relationship with the stock return after 4 weeks. This relationship differs among the industries. An abnormal search volume brings particularly severe price reversal on the stocks in the IT software industry, which are often to be targets of irrational investments by individual investors. An abnormal search volume caused less severe price reversal on the stocks in the manufacturing and IT hardware industries than on average across the industries. The price reversal was not observed in the communication, finance, entertainment, and transportation industries, which are known to be influenced largely by macro-economic factors such as oil price and currency exchange rate. The result of this study can be utilized to construct an intelligent trading system based on the big data gathered from web search engines, social network services, and internet communities. Particularly, the difference of price reversal effect between industries may provide useful information to make a portfolio and build an investment strategy.

The Relationship of Covert Narcissism, Sense of Alienation, and Self-Esteem with SNS Addiction Proneness in Middle School Students (중학생의 SNS중독 경향성에 있어 내현적 자기애와 소외감, 자아존중감의 관계)

  • Cho, So Yeon;Jung, Joowon
    • Journal of Korean Home Economics Education Association
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    • v.29 no.3
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    • pp.125-140
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    • 2017
  • The purpose of this study was to investigate the relationship of covert narcissism and the sense of alienation with SNS addiction proneness and the influence of them on SNS addiction proneness in order to find a way to conduct an intervention for the SNS addiction proneness of middle school students, and verify the mediating effect of self-esteem on the relationship between covert narcissism, the sense of alienation, and SNS addiction proneness. For this purpose, data were collected online from the first to third grade middle school students who had the experience of using SNS within the past one week, and finally, the data of a total of 341 participants were used for analysis. First, as a result of the analysis of the correlation between covert narcissism, the sense of alienation, self-esteem and SNS addiction proneness, covert narcissism and the sense of alienation showed a significant positive correlation with SNS addiction proneness. On the other hand, there was a significant negative correlation between self-esteem and SNS addiction proneness. Second, the investigation of the effects of covert narcissism, alienation, and self-esteem on SNS addiction proneness showed that covert narcissism, the sense of alienation, and self-esteem had a significant effect on the SNS addiction proneness. The higher the levels of covert narcissism and the sense of alienation, the higher the level of SNS addiction proneness. On the other hand, the higher the level of self-esteem, the lower the level of SNS addiction proneness. Third, the mediating effect of self-esteem was verified for the relationship of covert narcissism and the sense of alienation with SNS addiction proneness. Although covert narcissism and the sense of alienation may directly affect SNS addiction proneness, it was found that they had a significant effect on the SNS addiction proneness through self-esteem as a mediating variable. In other words, it was found that as the levels of the covert narcissism and the sense of alienation were increased, the level of the self-esteem was lowered, which led to a higher level of SNS addiction proneness. In order to form a proper network culture for adolescents, education on appropriate use of SNS that can be put into practice in everyday life should be conducted, and healthy and desirable SNS culture should be created. In addition, systematic education and management should be provided so that students can develop the ability to control and regulate themselves.

A 13b 100MS/s 0.70㎟ 45nm CMOS ADC for IF-Domain Signal Processing Systems (IF 대역 신호처리 시스템 응용을 위한 13비트 100MS/s 0.70㎟ 45nm CMOS ADC)

  • Park, Jun-Sang;An, Tai-Ji;Ahn, Gil-Cho;Lee, Mun-Kyo;Go, Min-Ho;Lee, Seung-Hoon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.3
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    • pp.46-55
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    • 2016
  • This work proposes a 13b 100MS/s 45nm CMOS ADC with a high dynamic performance for IF-domain high-speed signal processing systems based on a four-step pipeline architecture to optimize operating specifications. The SHA employs a wideband high-speed sampling network properly to process high-frequency input signals exceeding a sampling frequency. The SHA and MDACs adopt a two-stage amplifier with a gain-boosting technique to obtain the required high DC gain and the wide signal-swing range, while the amplifier and bias circuits use the same unit-size devices repeatedly to minimize device mismatch. Furthermore, a separate analog power supply voltage for on-chip current and voltage references minimizes performance degradation caused by the undesired noise and interference from adjacent functional blocks during high-speed operation. The proposed ADC occupies an active die area of $0.70mm^2$, based on various process-insensitive layout techniques to minimize the physical process imperfection effects. The prototype ADC in a 45nm CMOS demonstrates a measured DNL and INL within 0.77LSB and 1.57LSB, with a maximum SNDR and SFDR of 64.2dB and 78.4dB at 100MS/s, respectively. The ADC is implemented with long-channel devices rather than minimum channel-length devices available in this CMOS technology to process a wide input range of $2.0V_{PP}$ for the required system and to obtain a high dynamic performance at IF-domain input signal bands. The ADC consumes 425.0mW with a single analog voltage of 2.5V and two digital voltages of 2.5V and 1.1V.

Influential Job-Related Characteristics for the Job Satisfaction and Turnover Possibility of Dental Hygienists (치과위생사의 직무만족과 이직가능성에 영향을 미치는 직무관련특성 요인)

  • Lee, Chun-Sun;Park, So-Yong;Park, Hye-Min;You, Youn;Shin, Eun-Kyung;Chae, Song-I;Han, Seong-Ok;Oh, Hye-Young
    • Journal of dental hygiene science
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    • v.12 no.6
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    • pp.666-674
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    • 2012
  • The purpose of this study was to examine the job-related characteristics of dental hygienists affecting their job satisfaction and turnover possibility. The subjects in this study were 297 dental hygienists who worked in dental hospitals and clinics in the metropolitan area. The dental hygienists who worked for three to less than five years, who were unmarried and who didn't benefit from any incentive systems expressed a greater satisfaction, and those who were married, whose workplaces were established jointly with other dental institutions in the form of a network and whose workplaces offered incentives were more likely to change their employment. As for influential factors for job satisfaction and turnover possibility, the respondents whose workplaces were established jointly with other dental institutions were less satisfied, and a larger number of patients and better communication led to higher satisfaction. Those who worked in general hospitals were more likely to change their employment, and better welfare benefits, more appropriate length of working hours and a larger number of patients led to lower turnover responsibility. The findings of the study ascertained that working environments were one of the factors to impact on job satisfaction and turnover possibility, and both of hospitals and dental hygienists should make an effort to improve working environments.

Measurement of Backscattering Coefficients of Rice Canopy Using a Ground Polarimetric Scatterometer System (지상관측 레이다 산란계를 이용한 벼 군락의 후방산란계수 측정)

  • Hong, Jin-Young;Kim, Yi-Hyun;Oh, Yi-Sok;Hong, Suk-Young
    • Korean Journal of Remote Sensing
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    • v.23 no.2
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    • pp.145-152
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    • 2007
  • The polarimetric backscattering coefficients of a wet-land rice field which is an experimental plot belong to National Institute of Agricultural Science and Technology in Suwon are measured using ground-based polarimetric scatterometers at 1.8 and 5.3 GHz throughout a growth year from transplanting period to harvest period (May to October in 2006). The polarimetric scatterometers consist of a vector network analyzer with time-gating function and polarimetric antenna set, and are well calibrated to get VV-, HV-, VH-, HH-polarized backscattering coefficients from the measurements, based on single target calibration technique using a trihedral corner reflector. The polarimetric backscattering coefficients are measured at $30^{\circ},\;40^{\circ},\;50^{\circ}\;and\;60^{\circ}$ with 30 independent samples for each incidence angle at each frequency. In the measurement periods the ground truth data including fresh and dry biomass, plant height, stem density, leaf area, specific leaf area, and moisture contents are also collected for each measurement. The temporal variations of the measured backscattering coefficients as well as the measured plant height, LAI (leaf area index) and biomass are analyzed. Then, the measured polarimetric backscattering coefficients are compared with the rice growth parameters. The measured plant height increases monotonically while the measured LAI increases only till the ripening period and decreases after the ripening period. The measured backscattering coefficientsare fitted with polynomial expressions as functions of growth age, plant LAI and plant height for each polarization, frequency, and incidence angle. As the incidence angle is bigger, correlations of L band signature to the rice growth was higher than that of C band signatures. It is found that the HH-polarized backscattering coefficients are more sensitive than the VV-polarized backscattering coefficients to growth age and other input parameters. It is necessary to divide the data according to the growth period which shows the qualitative changes of growth such as panicale initiation, flowering or heading to derive functions to estimate rice growth.

Estimation of Paddy Rice Growth Parameters Using L, C, X-bands Polarimetric Scatterometer (L, C, X-밴드 다편파 레이더 산란계를 이용한 논 벼 생육인자 추정)

  • Kim, Yi-Hyun;Hong, Suk-Young;Lee, Hoon-Yol
    • Korean Journal of Remote Sensing
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    • v.25 no.1
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    • pp.31-44
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    • 2009
  • The objective of this study was to measure backscattering coefficients of paddy rice using a L-, C-, and X-band scatterometer system with full polarization and various angles during the rice growth period and to relate backscattering coefficients to rice growth parameters. Radar backscattering measurements of paddy rice field using multifrequency (L, C, and X) and full polarization were conducted at an experimental field located in National Academy of Agricultural Science (NAAS), Suwon, Korea. The scatterometer system consists of dual-polarimetric square horn antennas, HP8720D vector network analyzer ($20\;MHz{\sim}20\;GHz$), RF cables, and a personal computer that controls frequency, polarization and data storage. The backscattering coefficients were calculated by applying radar equation for the measured at incidence angles between $20^{\circ}$ and $60^{\circ}$ with $5^{\circ}$ interval for four polarization (HH, VV, HV, VH), respectively. We measured the temporal variations of backscattering coefficients of the rice crop at L-, C-, X-band during a rice growth period. In three bands, VV-polarized backscattering coefficients were higher than hh-polarized backscattering coefficients during rooting stage (mid-June) and HH-polarized backscattering coefficients were higher than VV-, HV/VH-polarized backscattering coefficients after panicle initiation stage (mid-July). Cross polarized backscattering coefficients in X-band increased towards the heading stage (mid-Aug) and thereafter saturated, again increased near the harvesting season. Backscattering coefficients of range at X-band were lower than that of L-, C-band. HH-, VV-polarized ${\sigma}^{\circ}$ steadily increased toward panicle initiation stage and thereafter decreased, and again increased near the harvesting season. We plotted the relationship between backscattering coefficients with L-, C-, X-band and rice growth parameters. Biomass was correlated with L-band hh-polarization at a large incident angle. LAI (Leaf Area Index) was highly correlated with C-band HH- and cross-polarizations. Grain weight was correlated with backscattering coefficients of X-band VV-polarization at a large incidence angle. X-band was sensitive to grain maturity during the post heading stage.

Improvement of Personal Information Protection Laws in the era of the 4th industrial revolution (4차 산업혁명 시대의 개인정보보호법제 개선방안)

  • Choi, Kyoung-jin
    • Journal of Legislation Research
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    • no.53
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    • pp.177-211
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    • 2017
  • In the course of the emergence and development of new ICT technologies and services such as Big Data, Internet of Things and Artificial Intelligence, the future will change by these new innovations in the Fourth Industrial Revolution. The future of this fourth industrial revolution will change and our future will be data-based society or economy. Since there is personal information at the center of it, the development of the economy through the utilization of personal information will depend on how to make the personal information protection laws. In Korea, which is trying to lead the 4th industrial revolution, it is a legal interest that can not give up the use of personal information, and also it is an important legal benefit that can not give up the personal interests of individuals who want to protect from personal information. Therefore, it is necessary to change the law on personal information protection in a rational way to harmonize the two. In this regard, this article discusses the problems of duplication and incompatibility of the personal information protection law, the scope of application of the personal information protection law and the uncertainty of the judgment standard, the lack of flexibility responding to the demand for the use of reasonable personal information, And there is a problem of reverse discrimination against domestic area compared to the regulated blind spot in foreign countries. In order to solve these problems and to improve the legislation of personal information protection in the era of the fourth industrial revolution, we proposed to consider both personal information protection and safe use by improving the purpose and regulation direction of the personal information protection law. The balance and harmony between the systematical maintenance of the personal information protection legislation and laws and regulations were also set as important directions. It is pointed out that the establishment of rational judgment criteria and the legislative review to clarify it are necessary for the constantly controversial personal information definition regulation and the method of allowing anonymization information as the intermediate domain. In addition to the legislative review for the legitimate and non-invasive use of personal information, there is a need to improve the collective consent system for collecting personal information to differentiate the subject and to improve the legislation to ensure the effectiveness of the regulation on the movement of personal information between countries. In addition to the issues discussed in this article, there may be a number of challenges, but overall, the protection and use of personal information should be harmonized while maintaining the direction indicated above.

A Study on Improvement of Laws regarding Welfare for the Aged (노인복지 관련법제의 발전방향)

  • Park, Ji-Soon
    • Journal of Legislation Research
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    • no.41
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    • pp.87-123
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    • 2011
  • Korea is expected to become an 'aged society' with more than 14 percent of the public aged 65 years or more by 2018. The rapid aging is giving rise to various problems within the society along with falling birthrate in a short period of time. In this context, the role and function of laws on welfare for the aged must be particularly emphasized. Also the Senior Citizens Welfare Act is of great importance as it provides social welfare service on the basis of functional connection with social insurance and public assistance. First, this paper looks into the history of laws related to welfare for the elderly such as the Senior Welfare Act, the Act on Long-term Care Insurance for Senior Citizens and the Basic Old Age Pension Act as well as the findings of earlier studies. In the second place, it will break down such laws by main components aiming to examine details of the laws and questions raised regarding them and to seek ways to achieve improvement with an emphasis on health care, old age income security, housing welfare(assisted living facilities), job security for the aged. The Senior Welfare Act offers substance of social welfare service for the elderly. Income security, health and medical care, welfare measures through long-term care and assisted living facilities, social participation by working are the key elements and all of them should be closely associated to ensure citizens get sufficient public support in their old age. For this purpose, the Senior Welfare Act is under a normative network with laws such as Act on Long-term Care Insurance for Senior Citizens and Basic Old Age Pension Act. Current laws on welfare for the aged including Senior Welfare Act are not sufficiently responsive to the aged society of the 21st century. Income security combined with decent social participation, health and medical care closely connected with long-term care system, efficient expense sharing between government and local government, enhancement of effectiveness of welfare measures can be considered as means to improve current welfare system so that the elderly can enjoy their old age with dignity and respect.

A Study on the Restructuration of Norm System in the Field of ICT for the Smart Media (Smart미디어시대 정보통신·미디어(ICT) 분야 규범체계의 재구조화에 관한 연구)

  • Ji, Seong-Woo
    • Journal of Legislation Research
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    • no.44
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    • pp.33-62
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    • 2013
  • In this paper, the consolidation of ICT basic legislation and ICT special legislation concerning "Ministry of Science, ICT and Future Planning" and "Korea Communications Commission" which came on the back of governmental reorganization in recent years is discussed in the theoretical and practical aspect. Development of "data communication technology" innovatively changed the method of livelihood of mankind, the emergence of network under global dimension provided financial social benefit and posed a challenge and a threat at the same time. Form digital revolution human kind can expect to receive many important blessings. Nevertheless, there are many advantages of development of technology by digital revolution, cyberspace like online media, internet etc. has realistically many problems that must be solved. To maximum positive aspects like the expansion of freedom of expression and creating plan of economy by the advance of transmission technology is needed. And to minimize side effects of informatization is required more. The First, Special Act on ICT has an adaptation in normative standardization to be fit in media convergence beyond convergence of broadcasting and telecommunications. Henceforth, there must be established a legal basis for the achievement of protection of economic evolution and freedom of speech in digital media, information, communication technology and content development. The second, the government action is to accomplish economic development and freedom of information in structural aspect of norm. Therefore minimizing normative problem by reorganization of organization remains clearly unresolved in politics. The third, Special Act on ICT must be basic law covering info-communications field, pay telecommunication and media contents field. The forth, from a technical point of view, net neutrality, conflict of interest for digital content and so on can be fixed easily. Special Act on ICT must not only pursuit of development of industry. Special Act on ICT and pursuit of enhancing quality of life of people and preparing program to promote democratization. From now on, we need to make powerful nation of information& communications technology and in information human rights protection field got to be one step ahead of others with reference to appear all the various aspects must be brought together in the discussion of legislation process of Special Act on ICT.

A Study on Perception Change in Bicycle users' Outdoor Activity by Particulate Matter: Based on the Social Network Analysis (미세먼지로 인한 자전거 이용객의 야외활동 인식변화에 관한 연구: 사회네트워크분석을 중심으로)

  • Kim, Bomi;Lee, Dong Kun
    • Journal of Environmental Impact Assessment
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    • v.28 no.5
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    • pp.440-456
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    • 2019
  • The controversy of the risk perception related to particulate matters becomes significant. Therefore, in order to understand the nature of the particulate matters, we gathered articles and comments in on-line community related to bicycling which is affected by exposure of the particulate matters. As a result, firstly, the government - led particulate matter policy was strengthened and segmented every period, butthe risk perception related to particulate matters in the bicycle community has become active and serious. Second, as a result of analyzing the perception change of outdoor activities related to particulate matters, bicycle users in community showed a tendency of outdoor activity depending on the degree of particulate matters ratherthan the weather. In addition, the level of the risk perception related to particulate matters has been moved from fears of serious threat in daily life and health, combined with the disregard of domestic particulate matter levels or mask performance. Ultimately, these risk perception related to particulate matters have led some of the bicycling that were mainly enjoyed outdoors to the indoor space. However, in comparison with outdoor bicycling enjoyed by various factors such as scenery, people, and weather, the monotonous indoor bicycling was converted into another type of indoor exercise such as fitness and yoga. In summary, it was derived from mistrust of excessive information or policy provided by the government or local governments. It is considered that environmental policy should be implemented after discussion of risk communication that can reduce the gap between public anxiety and concern so as to cope with the risk perception related to particulate matters. Therefore,this study should be provided as an academic basis for the effective communication direction when decision makers establish the policy related to particulate matters.