• Journal of the Korean Applied Science and Technology
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• v.37 no.3
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• pp.473-483
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• 2020

This paper proposes a tourism recommendation system in intelligent cloud environment using information of tourist behavior applied with perceived value. This proposed system applied tourist information and empirical analysis information that reflected the perceptual value of tourists in their behavior to the tourism recommendation system using wide and deep learning technology. This proposal system was applied to the tourism recommendation system by collecting and analyzing various tourist information that can be collected and analyzing the values that tourists were usually aware of and the intentions of people's behavior. It provides empirical information by analyzing and mapping the association of tourism information, perceived value and behavior to tourism platforms in various fields that have been used. In addition, the tourism recommendation system using wide and deep learning technology, which can achieve both memorization and generalization in one model by learning linear model components and neural only components together, and the method of pipeline operation was presented. As a result of applying wide and deep learning model, the recommendation system presented in this paper showed that the app subscription rate on the visiting page of the tourism-related app store increased by 3.9% compared to the control group, and the other 1% group applied a model using only the same variables and only the deep side of the neural network structure, resulting in a 1% increase in subscription rate compared to the model using only the deep side. In addition, by measuring the area (AUC) below the receiver operating characteristic curve for the dataset, offline AUC was also derived that the wide-and-deep learning model was somewhat higher, but more influential in online traffic.

• Journal of Intelligence and Information Systems
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• v.25 no.4
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• pp.123-139
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• 2019

The job classification system of major job sites differs from site to site and is different from the job classification system of the 'SQF(Sectoral Qualifications Framework)' proposed by the SW field. Therefore, a new job classification system is needed for SW companies, SW job seekers, and job sites to understand. The purpose of this study is to establish a standard job classification system that reflects market demand by analyzing SQF based on job offer information of major job sites and the NCS(National Competency Standards). For this purpose, the association analysis between occupations of major job sites is conducted and the association rule between SQF and occupation is conducted to derive the association rule between occupations. Using this association rule, we proposed an intelligent job classification system based on data mapping the job classification system of major job sites and SQF and job classification system. First, major job sites are selected to obtain information on the job classification system of the SW market. Then We identify ways to collect job information from each site and collect data through open API. Focusing on the relationship between the data, filtering only the job information posted on each job site at the same time, other job information is deleted. Next, we will map the job classification system between job sites using the association rules derived from the association analysis. We will complete the mapping between these market segments, discuss with the experts, further map the SQF, and finally propose a new job classification system. As a result, more than 30,000 job listings were collected in XML format using open API in 'WORKNET,' 'JOBKOREA,' and 'saramin', which are the main job sites in Korea. After filtering out about 900 job postings simultaneously posted on multiple job sites, 800 association rules were derived by applying the Apriori algorithm, which is a frequent pattern mining. Based on 800 related rules, the job classification system of WORKNET, JOBKOREA, and saramin and the SQF job classification system were mapped and classified into 1st and 4th stages. In the new job taxonomy, the first primary class, IT consulting, computer system, network, and security related job system, consisted of three secondary classifications, five tertiary classifications, and five fourth classifications. The second primary classification, the database and the job system related to system operation, consisted of three secondary classifications, three tertiary classifications, and four fourth classifications. The third primary category, Web Planning, Web Programming, Web Design, and Game, was composed of four secondary classifications, nine tertiary classifications, and two fourth classifications. The last primary classification, job systems related to ICT management, computer and communication engineering technology, consisted of three secondary classifications and six tertiary classifications. In particular, the new job classification system has a relatively flexible stage of classification, unlike other existing classification systems. WORKNET divides jobs into third categories, JOBKOREA divides jobs into second categories, and the subdivided jobs into keywords. saramin divided the job into the second classification, and the subdivided the job into keyword form. The newly proposed standard job classification system accepts some keyword-based jobs, and treats some product names as jobs. In the classification system, not only are jobs suspended in the second classification, but there are also jobs that are subdivided into the fourth classification. This reflected the idea that not all jobs could be broken down into the same steps. We also proposed a combination of rules and experts' opinions from market data collected and conducted associative analysis. Therefore, the newly proposed job classification system can be regarded as a data-based intelligent job classification system that reflects the market demand, unlike the existing job classification system. This study is meaningful in that it suggests a new job classification system that reflects market demand by attempting mapping between occupations based on data through the association analysis between occupations rather than intuition of some experts. However, this study has a limitation in that it cannot fully reflect the market demand that changes over time because the data collection point is temporary. As market demands change over time, including seasonal factors and major corporate public recruitment timings, continuous data monitoring and repeated experiments are needed to achieve more accurate matching. The results of this study can be used to suggest the direction of improvement of SQF in the SW industry in the future, and it is expected to be transferred to other industries with the experience of success in the SW industry.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.1
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• pp.29-38
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• 2012

Due to the rapid development of network environment and wireless communication technology, the distribution of digital video has made easily and the importance of the protection for digital video has been increased. This paper proposes the digital video encryption system based on multiple chaos maps for MPEG-2 video encoding process. The proposed method generates secret hash key of having 128-bit characteristics from hash chain using Tent map as a basic block and generates $8{\times}8$ lattice cipher by applying this hash key to Logistic map and Henon map. The method can reduce the encryption overhead by doing selective XOR operations between $8{\times}8$ lattice cipher and some coefficient of low frequency in DCT block and it provides simple and randomness characteristic because it uses the architecture of combining chaos maps. Experimental results show that PSNR of the proposed method is less than or equal to 12 dB with respect to encrypted video, the time change ratio, compression ratio of the proposed method are 2%, 0.4%, respectively so that it provides good performance in visual security and can be applied in real time.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.6
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• pp.679-685
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• 2018

In order to reduce marine accidents using advanced information and communication technology, various research and development projects are conducted globally on e-Navigation related technologies and services. Existing studies do not provide policy measures for LTE-M. In order for these technologies and services to be installed on vessels and to contribute to the prevention of accidents at sea, the law should be expand operational organizations and systems. In particular, communication equipment and related technical standards should be prepared, and its digital communication technology (LTE-M, VDES, Digital-MF / HF, etc.) In this study, we conducted short, medium, and long term performance assessment of the identification system and the policy for effective implementation of Korean e-Navigation. We presented a visible plan of the relevant policy. For example, e-Navigation core services, e-Navigation communication networks and operating systems, e-Navigation international standard leading technologies and e-navigation services activated in the field. To do this, we conducted research based on the progress data of the Korean e-Navigation project, which was led by the Ministry of Maritime Affairs and Fisheries, and conducted research discussions with practitioners and experts in related fields. As a result of this study, it is expected that the proposed policies will contribute to the reduction of marine accidents, the promotion of the maritime industry and the development of additional government policies for national security.

• The Korean Journal of Financial Management
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• v.26 no.3
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• pp.103-138
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• 2009

In this article we examine a unique data set of intraday fair disclosure(FD) releases to shed light on market efficiency within the trading day. Specifically, this paper analyze the response of stock prices on fair disclosure disseminated in real-time through KIND(Korea Investor's Network for Disclosure) on Korea stock exchange during the period from January 2003 to September 2004. We find that the prices of stock experiences a statistically and economically significant increase beginning seconds after the fair disclosure is initially announced and lasting approximately two minutes. The stock price responds more strongly to fair disclosure on smaller firm but the response to fair disclosure on the largest firm stock is more gradual, lasting five minutes. We also examine the profitability of a short-term trading strategy based on dissemination of fair disclosure. After controlling for trading costs we find that trader who execute a trade following initial disclosure generate negative profits, but trader buying stock before initial disclosure realize statistically significant positive profit after two minute of disclosure. Summarizing overall results, our evidence supports that security prices on Korea stock exchange reflects all available information within two minutes and the Korea stock market is semi-strongly efficient enough that a trader cannot generate profits based on widely disseminated news unless he acts almost immediately.

• The Korean Journal of Air & Space Law and Policy
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• v.1
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• pp.87-123
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• 1989

The purpose of this thesis is to do a research on suppression of peacetime international terrorism and penal system of terrorists by political and economic means. International terrorism means wanton killing, hostage taking, hijacking, extortion or torture committed or threatened to be comitted against the innocent civilian in peacetime for political motives or purposes provided that international element is involved therein. This research is limited to international terrorism of political purposes in peacetime, especially, hijacking of civil aircraft. Hijacking of civil aircraft include most of international terrorism element in its criminal act and is considered to be typical of international terrorism in view of multinationality of its crews, passengers and transnational borders involved in aircraft hijacking. Civil air transportation of today is a indispensable part of international substructure, as it help connect continuously social cultural and economic network of world community by dealing with massive and swift transportation of passengers and all kinds of goods. Current frequent hijacking of civil aircraft downgrade the safety and trust of air travel by mass slaughter of passengers and massdestruction of goods and endanger indispensable substructure of world community. Considering these facts, aircraft hijacking of today poses the most serious threat and impact on world community. Therefore, among other thing, legal, political, diplomatic and economic sanctions should be imposed on aircraft hijacking. To pursue an effective research on this thesis aircraft hijacking by six Chineses on 5th May, 1983, from mainland China to Seoul, Korea, is chosen as main theme and the Republic of Korea's legal, political and diplomatic dealing and settlement of this hijacking incident along with six hijackers is reviewed to find out legal, political diplomatic means of suppression and solution of international terrorism. Research is focused on Chinese aircraft hijacking, Korea-China diplomatic negotiation, Korea's legal diplomatic handling and settlement of Tak Chang In, mastermind of aircraft hijacking and responses and position of three countries, Korea, China and Taiwan to this case is thoroughly analyzed through reviewing such materials as news reportings and comments of local and international mass media, Korea-China Memorandum, statements of governments of Korea, China and Taiwan, verdicts of courts of Korea, prosecution papers and oral argument by the defendants and lawyers and three antiaircraft hijacking conventions of Hague, Tokyo and Montreal and all the other instruments of international treaties necessary for the research. By using above-mentioned first-hand meterials as yardsticks, legal and political character of Chinese aircraft hijacking is analyzed and reviewed and close cooperation among sovereign states based on spirit of solidarity and strict observance of international treaties such as Hague, Tokyo and Montreal Conventions is suggested as a solution and suppressive means of international terrorism. The most important and indispensable factor in combating terrorism is, not to speak, the decisive and constant resolution and all-out effort of every country and close cooperation among sovereign states based on "international law of cooperation."

• The KIPS Transactions:PartC
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• v.13C no.7 s.110
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• pp.821-830
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• 2006

As internet worms are spread out worldwide, the detection and filtering of worms becomes one of hot issues in the internet security. As one of implementation methods to detect worms, the Linux Netfilter kernel module can be used. Its basic operation for worm detection is a string matching where coming packet(s) on the network is/are compared with predefined worm signatures(patterns). A worm can appear in a packet or in two (or more) succeeding packets where some part of worm is in the first packet and its remaining part is in its succeeding packet(s). Assuming that the maximum length of a worm pattern is less than 1024 bytes, we need to perform a string matching up to two succeeding packets of 2048 bytes. To do so, Linux Netfilter keeps the previous packet in buffer and performs matching with a combined 2048 byte string of the buffered packet and current packet. As the number of concurrent connections to be handled in the worm detection system increases, the total size of buffer (memory) increases and string matching speed becomes low In this paper, to reduce the memory buffer size and get higher speed of string matching, we propose a string matching scheme without using buffer. The proposed scheme keeps the partial matching result of the previous packet with signatures and has no buffering for previous packet. The partial matching information is used to detect a worm in the two succeeding packets. We implemented the proposed scheme by modifying the Linux Netfilter. Then we compared the modified Linux Netfilter module with the original Linux Netfilter module. Experimental results show that the proposed scheme has 25% lower memory usage and 54% higher speed compared to the original scheme.

• Korean Journal of Remote Sensing
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• v.39 no.1
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• pp.77-86
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• 2023

Ship detection is widely used in areas such as maritime security, maritime traffic, fisheries management, illegal fishing, and border control, and ship detection is important for rapid response and damage minimization as ship accident rates increase due to recent increases in international maritime traffic. Currently, according to a number of global and national regulations, ships must be equipped with automatic identification system (AIS), which provide information such as the location and speed of the ship periodically at regular intervals. However, most small vessels (less than 300 tons) are not obligated to install the transponder and may not be transmitted intentionally or accidentally. There is even a case of misuse of the ship'slocation information. Therefore, in this study, ship detection was performed using high-resolution optical satellite images that can periodically remotely detect a wide range and detectsmallships. However, optical images can cause false-alarm due to noise on the surface of the sea, such as waves, or factors indicating ship-like brightness, such as clouds and wakes. So, it is important to remove these factors to improve the accuracy of ship detection. In this study, false alarm wasreduced, and the accuracy ofship detection wasimproved by removing wake.As a ship detection method, ship detection was performed using machine learning-based random forest (RF), and convolutional neural network (CNN) techniquesthat have been widely used in object detection fieldsrecently, and ship detection results by the model were compared and analyzed. In addition, in this study, the results of RF and CNN were combined to improve the phenomenon of ship disconnection and the phenomenon of small detection. The ship detection results of thisstudy are significant in that they improved the limitations of each model while maintaining accuracy. In addition, if satellite images with improved spatial resolution are utilized in the future, it is expected that ship and wake simultaneous detection with higher accuracy will be performed.

• Journal of Internet Computing and Services
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• v.23 no.6
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• pp.39-48
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• 2022

Cyberattacks around the world continue to increase, and their damage extends beyond government facilities and affects civilians. These issues emphasized the importance of developing a system that can identify and detect cyber anomalies early. As above, in order to effectively identify cyber anomalies, several studies have been conducted to learn BGP (Border Gateway Protocol) data through a machine learning model and identify them as anomalies. However, BGP data is unbalanced data in which abnormal data is less than normal data. This causes the model to have a learning biased result, reducing the reliability of the result. In addition, there is a limit in that security personnel cannot recognize the cyber situation as a typical result of machine learning in an actual cyber situation. Therefore, in this paper, we investigate BGP (Border Gateway Protocol) that keeps network records around the world and solve the problem of unbalanced data by using SMOTE. After that, assuming a cyber range situation, an autoencoder classifies cyber anomalies and visualizes the classified data. By learning the pattern of normal data, the performance of classifying abnormal data with 92.4% accuracy was derived, and the auxiliary index also showed 90% performance, ensuring reliability of the results. In addition, it is expected to be able to effectively defend against cyber attacks because it is possible to effectively recognize the situation by visualizing the congested cyber space.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.656-664
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• 2023

Purpose: The Ministry of Employment and Labor manages disasters based on the standard manual for risk management of large-scale human accidents in workplaces when large-scale disasters such as fires and collapses occur in workplaces. We are going to check the standard manual currently in operation and suggest improvement plans for the insufficient items. Method: Accordingly, the standard manual was checked together with internal and external experts in the disaster management manual and disaster management staff at headquarters and local government offices, and items to be improved were identified with priority. Result: In case of a collapse accident, it is necessary for the Ministry of Public Administration and Security to accurately present the selection criteria in order to eliminate the controversy over the selection of the disaster management department. In addition, it seems necessary to supplement the details of the disaster safety communication network operation and evacuation guidelines. Conclusion: In the future, in order to improve the disaster management system that meets the public's eye level, it is expected to prepare a standard manual for risk management of large-scale human accidents in workplaces that guarantees the lives and safety of workers through the collection of opinions from experts in the relevant field, disaster management personnel, and the general public.