• Journal of Intelligence and Information Systems
• /
• v.24 no.2
• /
• pp.195-220
• /
• 2018

In this study, we conducted an empirical analysis of the factors that affect the change of Bitcoin Closing Price. Previous studies have focused on the security of the block chain system, the economic ripple effects caused by the cryptocurrency, legal implications and the acceptance to consumer about cryptocurrency. In various area, cryptocurrency was studied and many researcher and people including government, regardless of country, try to utilize cryptocurrency and applicate to its technology. Despite of rapid and dramatic change of cryptocurrencies' price and growth of its effects, empirical study of the factors affecting the price change of cryptocurrency was lack. There were only a few limited studies, business reports and short working paper. Therefore, it is necessary to determine what factors effect on the change of closing Bitcoin price. For analysis, hypotheses were constructed from three dimensions of consumer, industry, and macroeconomics for analysis, and time series data were collected for variables of each dimension. Consumer variables consist of search traffic of Bitcoin, search traffic of bitcoin ban, search traffic of ransomware and search traffic of war. Industry variables were composed GPU vendors' stock price and memory vendors' stock price. Macro-economy variables were contemplated such as U.S. dollar index futures, FOMC policy interest rates, WTI crude oil price. Using above variables, we did times series regression analysis to find relationship between those variables and change of Bitcoin Closing Price. Before the regression analysis to confirm the relationship between change of Bitcoin Closing Price and the other variables, we performed the Unit-root test to verifying the stationary of time series data to avoid spurious regression. Then, using a stationary data, we did the regression analysis. As a result of the analysis, we found that the change of Bitcoin Closing Price has negative effects with search traffic of 'Bitcoin Ban' and US dollar index futures, while change of GPU vendors' stock price and change of WTI crude oil price showed positive effects. In case of 'Bitcoin Ban', it is directly determining the maintenance or abolition of Bitcoin trade, that's why consumer reacted sensitively and effected on change of Bitcoin Closing Price. GPU is raw material of Bitcoin mining. Generally, increasing of companies' stock price means the growth of the sales of those companies' products and services. GPU's demands increases are indirectly reflected to the GPU vendors' stock price. Making an interpretation, a rise in prices of GPU has put a crimp on the mining of Bitcoin. Consequently, GPU vendors' stock price effects on change of Bitcoin Closing Price. And we confirmed U.S. dollar index futures moved in the opposite direction with change of Bitcoin Closing Price. It moved like Gold. Gold was considered as a safe asset to consumers and it means consumer think that Bitcoin is a safe asset. On the other hand, WTI oil price went Bitcoin Closing Price's way. It implies that Bitcoin are regarded to investment asset like raw materials market's product. The variables that were not significant in the analysis were search traffic of bitcoin, search traffic of ransomware, search traffic of war, memory vendor's stock price, FOMC policy interest rates. In search traffic of bitcoin, we judged that interest in Bitcoin did not lead to purchase of Bitcoin. It means search traffic of Bitcoin didn't reflect all of Bitcoin's demand. So, it implies there are some factors that regulate and mediate the Bitcoin purchase. In search traffic of ransomware, it is hard to say concern of ransomware determined the whole Bitcoin demand. Because only a few people damaged by ransomware and the percentage of hackers requiring Bitcoins was low. Also, its information security problem is events not continuous issues. Search traffic of war was not significant. Like stock market, generally it has negative in relation to war, but exceptional case like Gulf war, it moves stakeholders' profits and environment. We think that this is the same case. In memory vendor stock price, this is because memory vendors' flagship products were not VRAM which is essential for Bitcoin supply. In FOMC policy interest rates, when the interest rate is low, the surplus capital is invested in securities such as stocks. But Bitcoin' price fluctuation was large so it is not recognized as an attractive commodity to the consumers. In addition, unlike the stock market, Bitcoin doesn't have any safety policy such as Circuit breakers and Sidecar. Through this study, we verified what factors effect on change of Bitcoin Closing Price, and interpreted why such change happened. In addition, establishing the characteristics of Bitcoin as a safe asset and investment asset, we provide a guide how consumer, financial institution and government organization approach to the cryptocurrency. Moreover, corroborating the factors affecting change of Bitcoin Closing Price, researcher will get some clue and qualification which factors have to be considered in hereafter cryptocurrency study.

• The Korean Journal of Air & Space Law and Policy
• /
• v.24 no.2
• /
• pp.163-186
• /
• 2009

The missile technology and its development in south Korea have been restrained to the limit of 180 km by America which instead provided to Korea with security protection. In the same vein, America pressured South Korea to abort its nuclear weapons program so as to prevent another possible military encounter that can easily develop into a war between South and North Korea. This restraint was a bit relaxed when South Korea joined the Missile Technology Control Regime (MTCR) in 2001 whereby the limit was 300 km. The situation of South Korea is in much contrast with its neighbor, North Korea, which has fired Taepo Dong 1 and Taepo Dong 2 to put its alleged satellite respectively into the Earth orbit. The range of this rocket believed to be reaching more than 5,500 km, a range of the intercontinental ballistic missile, without any rein. South Korea that has just geared its full powers for its outer space industry, with the current space projects of putting its satellites into the low Earth orbit, will in future put its satellite into the geostationary orbit, 36,000 km above the Earth. To do so, such restraint had better be resolved. Korean space industry, as it is alike in other countries, started with putting and manufacturing sounding rockets, producing satellites but relying on foreign launching facilities, and learning launching capacities. Experiencing three time launchings of KITSAT, the current satellite projects of Korea are undertaken as follows: - Koreasat - STSAT - Komsat - MBSAT - COMS (Communication, Ocean, and Meteorological Satellite) Koreans waked up to the things of outer space in 2008 with the first Korean astronaut Li So-yeon, a lady bio systems engineer. Although the first Korean made rocket in cooperation with a Russian company to fire last August 2009 was a failure, it should be considered as an inevitable process for future endeavors. There are currently three outer space related laws of Korea: Aerospace Industry Development Promotion Act 1987, Outer Space Development Promotions Act 2005, and Space Damage Compensation Act 2008. The first two stemming from the two different ministries are, however, overlapping in many aspects and have some shortcomings to be improved.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.43 no.2 s.308
• /
• pp.19-29
• /
• 2006

As the security of personal information is becoming more important in mobile phones, we are starting to apply iris recognition technology to these devices. In conventional iris recognition, magnified iris images are required. For that, it has been necessary to use large magnified zoom & focus lens camera to capture images, but due to the requirement about low size and cost of mobile phones, the zoom & focus lens are difficult to be used. However, with rapid developments and multimedia convergence trends in mobile phones, more and more companies have built mega-pixel cameras into their mobile phones. These devices make it possible to capture a magnified iris image without zoom & focus lens. Although facial images are captured far away from the user using a mega-pixel camera, the captured iris region possesses sufficient pixel information for iris recognition. However, in this case, the eye region should be detected for accurate iris recognition in facial images. So, we propose a new fast iris detection method, which is appropriate for mobile phones based on corneal specular reflection. To detect specular reflection robustly, we propose the theoretical background of estimating the size and brightness of specular reflection based on eye, camera and illuminator models. In addition, we use the successive On/Off scheme of the illuminator to detect the optical/motion blurring and sunlight effect on input image. Experimental results show that total processing time(detecting iris region) is on average 65ms on a Samsung SCH-S2300 (with 150MHz ARM 9 CPU) mobile phone. The rate of correct iris detection is 99% (about indoor images) and 98.5% (about outdoor images).

• Journal of Gifted/Talented Education
• /
• v.25 no.2
• /
• pp.339-358
• /
• 2015

This study was to examine perceptions of information technology(IT) competencies among gifted and non-gifted students(i.e., information science high school students and technical high school students). Of the 370 high school students surveyed from 3 high schools(i.e., gifted academy, information science high school, and technical high school) in three metropolitan cities, Korea, 351 students completed and returned the questionnaires yielding a total response rate of 94.86%. High school students recognized the IT professional competence as being most important when recruiting IT employees. And they considered that practice-oriented education was the most importantly needed to improve their IT skills. In addition, the most important sub-factors of IT core competencies among gifted academy students and information science high school students were basic software skills. Also Technical high school students responded that the main network and security capabilities were the most importantly needed to do so. Finally, the most appropriate training courses for enhancing IT competencies were recognized differently among gifted and non-gifted students. Gifted academy students responded that the 'algorithm' was the mostly needed for enhancing IT competencies, whereas information science high school students responded that 'data structures' and 'computer architecture' were mostly needed to do. For technical high school students, they responded that a 'programming language' course was the most needed to do so. Results are discussed in relations to IT corporate and school settings.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.19 no.2
• /
• pp.131-146
• /
• 2014

High-resolution seismic profiles coupled with sediment sampling were analyzed to investigate the acoustic characters and distribution patterns of the late Holocene sediments in Gamak Bay of the South Sea, Korea. The mean grain size of surficial sediment lies around $6.3{\sim}9.7{\Phi}$. Sediments in the bay consist of silt and clay with progressive decrease toward the inner bay. The seismic sedimentary sequence overlying the acoustic basement can be divided into two sedimentary units (GB I and II) by a prominent mid-reflector (Maximum Flooding Surface; MFS). The acoustic basement occurs at the depth between 20 m and 40 m below the sea-level and deepens gradually southward. The GB I, mostly occupying the channel-fill, is characterized by reflection-free seismic facies. It can be formed as late Transgressive System Tract (TST), interpreted tidal environment deposits. MFS appears at the depth of about 15~28 m below the sea-level and is well defined by even and continuous reflectors on the seismic profile. The GB II overlying MFS is composed of acoustically transparent to semitransparent and parallel internal reflectors. GB II is interpreted as the Highstand System Tract (HST) probably deposited during the last 6,000 yrs when the sea level was close to the present level. Especially, it is though that the GB II was subdivided into two layers (GB II-a and II-b) by a HST-reflector and this was classified by wind, sea water flux, and tidal current.

• Journal of Animal Science and Technology
• /
• v.55 no.5
• /
• pp.483-488
• /
• 2013

To develop a sustainable composting method for livestock mortality, a natural aeration-composting process was designed and the influences of bulking materials on the mortality composting process were studied. Bulking materials (e.g., compost, swine manure, sawdust, and rice husks), easily supplied at the scene of an animal mortality outbreak, were tested in this research. A lab-scale composting system (W34 ${\times}$ L60 ${\times}$ H26 cm) was made using 100 mm styrofoam, and natural aeration was achieved through pipes installed on the bottom of the system. Four treatments were designed (compost, compost + swine feces, sawdust, and rice husks treatment groups) and all experiments were done in triplicates. During composting for 40 days, no leachate was observed in compost and sawdust treatment groups, whereas 18 and 8.2 ml leachate/kg-mortality was emitted from the compost + feces and rice husks treatment groups, respectively. Dimethyl disulfide (DMDS) emission during the composting was very low in all treatment groups, possibly due to the bio-filtering function of the compost cover layer on the pile. The mortality degradability in compost, compost + feces, sawdust, and rice husks groups was 25.3, 25.8, 13.5, and 14.5%, respectively, showing significantly higher levels in compost and compost + feces groups (p<0.05). Also, only the compost + feces group produced enough heat (over $55^{\circ}C$) and lasted for 7 days, indicating that bio-security cannot be guaranteed without feces supplementation.

• Journal of Nutrition and Health
• /
• v.53 no.1
• /
• pp.54-67
• /
• 2020

Purpose: This study examined the relationship between job stress, attributes of health functional food (HFF) selection, and consumption values for information technology (IT) workers, and analyzed the factors influencing the selection of HFF to improve health by making the right choice of HFFs. Methods: Three hundred forty IT workers in Gyeonggi area participated in the study. The participants were divided into low or high job stress group. The differences in participants' general characteristics, attributes of HFF selection, and HFF consumption values were investigated, and the mediating effects of HFF consumption values on the relationship between job stress levels and the HFF selection attributes were analyzed. Results: Job stress levels were high in those IT workers with a length of service < 5 years (p = 0.013). The group with lower job stress levels had a higher tendency to consider the ingredients contained in HFF products (p < 0.001), and their efficacy (p = 0.047). They also showed greater emotional value for a sense of security from consuming HFFs to stay healthy (p = 0.047). The group with higher job stress levels had greater epistemic value in that their choice of HFFs differentiated them from the other workers (p = 0.036). Higher job stress was associated with less consideration of the intrinsic attributes such as ingredients and efficacy of the HFF selection attributes (p = -0.113), emotional value of the HFF consumption values (p = -0.136), and the functional value such as practicality, price, and safety (p = -0.134). The job stress level influenced the intrinsic attributes through the functional and emotional values, demonstrating that the functional and emotional values had appropriate mediating effects on the relationship between job stress levels and intrinsic attributes. Conclusion: Education needs to be provided for workers to relieve job stress and improve the functional and emotional values, which contributes to choosing the appropriate HFFs.

• Journal of the Korean Society of Radiology
• /
• v.6 no.2
• /
• pp.143-149
• /
• 2012

Today each hospital is trend that change rapidly by up to date, digitization and introducing newest medical treatment equipment. So, we introduce new CR system and supplement film system's shortcoming and PACS, EMR, RTP system's network that is using in hospital harmoniously and accomplish quality improvement of medical treatment and service elevation about business efficiency enlargement and patient Accordingly, we wish to introduce our case that integrate reflex that happen with radiation oncology here upon to PACS using CR system and estimate the availability. We measured that is Gantry, Collimator Star Shot, Light vs. Radiation, HDR QA(Dwell position accuracy) with Medical LINAC(MEVATRON-MX) Then, PACS was implemented on the digital images on the monitor that can be confirmed through the QA. Also, for cooperation with OCS system that is using from present source and impose code that need in treatment in each treatment, did so that Order that connect to network, input to CR may appear, did so that can solve support data mistake (active Pinacle's case supports DICOM3 file from present source but PACS does not support DICOM3 files.) of Pinacle and PACS that is Planning System and look at Planning premier in PACS. All image and data constructed integration to PACS as can refer and conduct premier in Hospital anywhere using CR system. Use Dosimetry IP in Filmless environment and QA's trial such as Light/Radition field size correspondence, gantry rotation axis' accuracy, collimator rotation axis' accuracy, brachy therapy's Dwell position check is available. Business efficiency by decrease and so on of unnecessary human strength consumption was augmented accordingly with session shortening as that integrate premier that is neted with radiation oncology using CR system to PACS. and for the future patient information security is essential.

• Asia pacific journal of information systems
• /
• v.17 no.2
• /
• pp.123-137
• /
• 2007

The advent of the Internet and related Web technologies has created an easily accessible link between a firm and its customers, and has provided opportunities to a firm to use information technology to support supplementary after-sale services associated with a product or service. It has been widely recognized that supplementary services are an important source of customer value and of competitive advantage as the characteristics of the product itself. Many of these supplementary services are information-based and need not be co-located with the product, so more and more companies are delivering these services electronically. Net-based customer service, which is defined as an Internet-based computerized information system that delivers services to a customer, therefore, is the core infrastructure for supplementary service provision. The importance of net-based customer service in delivering supplementary after-sale services associated with product has been well documented. The strategic advantages of well-implemented net-based customer service are enhanced customer loyalty and higher lock-in of customers, and a resulting reduction in competition and the consequent increase in profits. However, not all customers utilize such net-based customer service. The digital divide is the phenomenon in our society that captures the observation that not all customers have equal access to computers. Socioeconomic factors such as race, gender, and education level are strongly related to Internet accessibility and ability to use. This is due to the differences in the ability to bear the cost of a computer, and the differences in self-efficacy in the use of a technology, among other reasons. This concept, applied to e-commerce, has been called the "e-commerce divide." High Internet penetration is not eradicating the digital divide and e-commerce divide as one would hope. Besides, to accommodate personalized support, a customer must often provide personal information to the firm. This personal information includes not only name and address, but also preferences information and perhaps valuation information. However, many recent studies show that consumers may not be willing to share information about themselves due to concerns about privacy online. Due to the e-commerce divide, and due to privacy and security concerns of the customer for sharing personal information with firms, limited numbers of customers adopt net-based customer service. The limited level of customer adoption of net-based customer service affects the firm profits and the customers' welfare. We use a game-theoretic model in which we model the net-based customer service system as a mechanism to enhance customers' loyalty. We model a market entry scenario where a firm (the incumbent) uses the net-based customer service system in inducing loyalty in its customer base. The firm sells one product through the traditional retailing channels and at a price set for these channels. Another firm (the entrant) enters the market, and having observed the price of the incumbent firm (and after deducing the loyalty levels in the customer base), chooses its price. The profits of the firms and the surplus of the two customers segments (the segment that utilizes net-based customer service and the segment that does not) are analyzed in the Stackelberg leader-follower model of competition between the firms. We find that an increase in adoption of net-based customer service by the customer base is not always desirable for firms. With low effectiveness in enhancing customer loyalty, firms prefer a high level of customer adoption of net-based customer service, because an increase in adoption rate decreases competition and increases profits. A firm in an industry where net-based customer service is highly effective loyalty mechanism, on the other hand, prefers a low level of adoption by customers.

• The Korean Journal of Air & Space Law and Policy
• /
• v.26 no.2
• /
• pp.3-39
• /
• 2011

People may operate unmanned aerial vehicles (UAVs or drones) thousands of miles from the drone's location. Drones were first used (like balloons) for surveillance. By 2001, the United States began arming drones with missiles and using them to strike targets during combat in Afghanistan. By mid-2010, over forty states and other entities possessed drones, many with the capability of launching missiles and dropping bombs. Each new development in military weapons technology invites assessment of the relevant international law. This Insight surveys the international law applicable to the recent innovation of weaponizing drones. In determining what international law rules govern drone use, the most salient feature is not the fact that drones are unmanned. The fact drones carry no human operator may be the most important new technological breakthrough, but the key feature for international law purposes is the type of weaponry drones carry. Whether law enforcement rules govern drone use depends on the situation and not necessarily who is operating the drone. Battlefield weapons may also be lawfully used before an armed conflict in the following situations: when initiating self-defense under Article 51 of the United Nations Charter; when authorized by the UN Security Council; when a government seeks to suppress internal armed conflict; and, perhaps, when a state is invited to assist a government in suppressing internal armed conflict. The rules governing resort to force in self-defense are found in Article 51 of the UN Charter and a number of decisions by international courts and tribunals. Commentators continue to debate whether drone technology represents the next revolution in military affairs. Regardless of the answer to that question, drones have not created a revolution in legal affairs. The current rules governing battlefield launch vehicles are adequate for regulating resort to drones. More research must be undertaken, however, to understand the psychological effects of deploying unmanned vehicles and the effects on drone operators of sustained, close visual contact with the aftermath of drone attacks.