• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.1
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• pp.71-77
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• 2006

Several network attacks, such as distributed denial of service (DDoS) attack, present a very serious threat to the stability of the internet. The threat posed by network attacks on large networks, such as the internet, demands effective detection method. Therefore, a simple intrusion detection system on large-scale backbone network is needed for the sake of real-time detection, preemption and detection efficiency. In this paper, in order to discriminate attack traffic from legitimate traffic on backbone links, we suggest a relatively simple statistical measure, entropy, which can track value frequency. Den is conspicuous distinction of entropy values between attack traffic and legitimate traffic. Therefore, we can identify what kind of attack it is as well as detecting the attack traffic using entropy value.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.4
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• pp.117-122
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• 2021

Permanent magnet synchronous motors can secure high power density and efficiency, but have problems in that the materials required for manufacturing are expensive and design is somewhat more difficult than induction motors. Therefore, it is necessary to develop an optimal motor that considers both efficiency and maintenance convenience and related control research. In addition, driving by a practical motor leads to a request to increase the highest efficiency in a narrow rated range, an increase in average efficiency in the entire electric driving range, and an increase in average output. Due to this movement, a reluctance motor that does not require a permanent magnet is being considered as an alternative. In this paper, in line with the issues of the times that require the development of future technology that can replace rare earth permanent magnet motors and the technological preemption of rare earth reduction motors and rare earth motors, switched reluctance motors without permanent magnet For motor, SRM), modeling through machine language (C language) and the characteristics of SRM accordingly are to be studied.

• Journal of People, Plants, and Environment
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• v.24 no.4
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• pp.389-401
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• 2021

Background and objective: The purpose of this study is to investigate the ecological status of six areas around Geumgang River that used to be farmlands before they were restored as a riverine ecobelt. This study aims to analyze the correlation between the location environment and ecological status of the sites to identify the environmental factors affecting them. Methods: The sites are classified into four types according to restoration: terraced paddy fields, flat paddy fields, artificial wetland, and landscape forest. The survey items were divided into land use status, plant ecology, and animal ecology. Results: In terms of plant ecology, terraced paddy fields showed favorable naturality with the rate of native species above 90% and the naturalization index below 10%. In terms of animal ecology, the total number of species found in these areas was biggest in terraced paddy fields, followed by flat paddy fields, artificial wetland, and landscape forest. Regarding species diversity, terraced paddy fields also showed abundant species with an average of 1.05 to 1.09. The results of the correlation analysis showed that the forest area around the sites had the most significant effect on species diversity. The grassland and open water area showed a positive correlation with the total number of animal species and the number of dragonflies, confirming that the marshy grassland had a positive effect. As the cultivated land and urbanized area around the sites increased, it had a negative effect on the distribution of native species and the number of animal species that appeared, and a positive effect on the naturalization index. Conclusion: It is necessary to establish preemption and restoration plans for sites such as grasslands adjacent to the forest and terraced paddy fields in order to promote resilience of the diverse species returning to the purchased lands.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.4
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• pp.543-554
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• 2022

In this study, the government's investment, laws, regulations, and difficulties related to IoT radio technology in the energy and medical fields are mainly analyzed. Also, plans for dissemination, technology preemption, and commercialization are derived to enhance global competitiveness. Research on ways to secure and predict radio wave application technologies in energy and medical fields, and to alleviate barriers to entry for new business operators. Analyzes the efficiency of support measures using expert groups in each energy and medical field, analyzes the utilization value of accumulated data, and proposes mid- to long-term promotion systems and support measures, as well as utilization measures of data held by external agencies related to radio waves.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8B
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• pp.509-520
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• 2007

In this paper, we propose a real-time sensor node platform that guarantees the real-time scheduling of periodic and aperiodic tasks through a multitask-based software decomposition technique. Since existing sensor networking operation systems available in literature are not capable of supporting the real-time scheduling of periodic and aperiodic tasks, the preemption of aperiodic task with high priority can block periodic tasks, and so periodic tasks are likely to miss their deadlines. This paper presents a comprehensive evaluation of how to structure periodic or aperiodic task decomposition in real-time sensor-networking platforms as regard to guaranteeing the deadlines of all the periodic tasks and aiming to providing aperiodic tasks with average good response time. A case study based on real system experiments is conducted to illustrate the application and efficiency of the multitask-based dynamic component execution environment in the sensor node equipped with a low-power 8-bit microcontroller, an IEEE802.15.4 compliant 2.4GHz RF transceiver, and several sensors. It shows that our periodic and aperiodic task decomposition technique yields efficient performance in terms of three significant, objective goals: deadline miss ratio of periodic tasks, average response time of aperiodic tasks, and processor utilization of periodic and aperiodic tasks.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.6
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• pp.495-508
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• 2017

Today, MMS (Mobile Mapping System) uses the strengths of individual sensor technologies on a variety of platforms to increase the efficiency of geospatial data collection. In this paper, we analyzed the market size and technology trend of mobile mapping market in Korea and abroad, and analyzed frequency, trend, and characteristics of MMS related patents. The results of the analysis are as follows: First, it is expected that the domestic and overseas mobile mapping market will continue to grow in the future, and MMS-related technologies and applications are rapidly developing. Active research and development investment is required to preoccupy future market through technology development and patent competition. Second, the frequency of filing domestic patents is highly correlated with the results of national R&D, and industrial patent applications are highly related to national projects. It is analyzed as the result of introduction of preemptive technologies and research and development of companies for preemption in related industry rather than market development. Lastly, in Korean geospatial information industry survey, It is necessary to maintain the data so that it can be compared with the data of foreign institutions. In particular, statistical data that can grasp the market size in terms of geospatial information utilization and technical aspects are desperately needed.

• Strategy21
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• s.39
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• pp.5-46
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• 2016

North Korea's 4th nuclear test on Jan. 6 and following developments once again awakened the world into seriousness of the nuclear matters on the Korean peninsula. On March 2, UNSC adopted Resolution 2270 which is complemented by Seoul government's measures such as withdrawal from the Gaesung Industrial Complex (Feb. 9) and announcement of unilateral sanction (March 8). Seoul government also strongly urged the international community to strangle North Korea's 'financial resources.' The U.S., Japan, China, and other countries have issued unilateral sanctions to complement the UNSC measure. South Korea and the U.S. conducted their annual joint military drill (Resolve-Foal Eagle) in the largest-ever scale. North Korea, however, responded with demonstration of its nuclear capabilities and announcement of de facto 'nuclear-first' politics. North Korea test-fired a variety of delivery vehicles, threatened nuclear strikes against South Korea and the U.S., and declared itself as an 'invincible nuclear power armed with hydrogen bombs' at the 7th Workers 'Party Congress held in May, 2016. Considering the circumstantial evidences, the North's 4th nuclear test may have been a successful boosted fission bomb test. North Korea, and, if allowed to go on with its nuclear programs, will become a nuclear power armed with more than 50 nuclear weapons including hydrogen bombs. The North is already conducting nuclear blackmail strategy towards South Korea, and must be developing 'nuclear use' strategies. Accordingly, the most pressing challenge for the international community is to bring the North to 'real dialogue for denuclearization through powerful and consistent sanctions. Of course, China's cooperation is the key to success. In this situation, South Korea has urgent challenges on diplomacy and security fronts. A diplomatic challenge is how to lead China, which had shown dual attitudes between 'pressure and connivance' towards the North's nuclear matters pursuant to its military relations with the U.S, to participate in the sanctions consistently. A military one is how to offset the 'nuclear shadow effects' engendered by the North's nuclear blackmail and prevent its purposeful and non-purposeful use of nuclear weapons. Though South Korea's Ministry of Defense is currently spending a large portion of defense finance on preemption (kill-chain) and missile defense, they pose 'high cost and low efficiency' problems. For a 'low cost and high efficiency' of deterrence, South Korea needs to switch to a 'retaliation-centered' deterrence strategy. Though South Korea's response to the North's nuclear threat can theoretically be boiled down into dialogue, sanction and deterrence, now is the time to concentrate on strong sanction and determined deterrence since they are an inevitable mandatory course to destroy the North' nuclear-first delusion and bring it to a 'real denuclearization dialogue.'

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.2
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• pp.174-182
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• 2002

The object-oriented design methods and their CASE tools are widely used in practice by many real-time software developers. However, object-oriented CASE tools require an additional step of identifying tasks from a given design model. Unfortunately, it is difficult to automate this step for a couple of reasons: (1) there are inherent discrepancies between objects and tasks; and (2) it is hard to derive tasks while maximizing real-time schedulability since this problem makes a non-trivial optimization problem. As a result, in practical object-oriented CASE tools, task identification is usually performed in an ad-hoc manner using hints provided by human designers. In this paper, we present a systematic, schedulability-aware approach that can help mapping real-time object-oriented models to multi-threaded implementations. In our approach, a task contains a group of mutually exclusive transactions that may possess different periods and deadline. For this new task model, we provide a new schedulability analysis algorithm. We also show how the run-time system is implemented and how executable code is generated in our frame work. We have performed a case study. It shows the difficulty of task derivation problem and the utility of the automated synthesis of implementations as well as the Inappropriateness of the single-threaded implementations.

• Fire Science and Engineering
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• v.34 no.1
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• pp.121-126
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• 2020

The aim of this study is to suggest ways to capitalize on the golden period for timely response to fire and emergency victims. To implement a system to effectively capitalize on the golden period, there is a need for policy measures as well as legal and social consensus. Precedent research has relentlessly mentioned the need for and feasibility of the priority traffic system for emergency vehicles. To this end, the present study involved an analysis of pilot cases of the priority traffic signal system for emergency vehicles introduced in a city during 26 days, from April 3 to 28, 2017. Out of 58 cases registered with the local 1-1-9 fire house, the number of cases that took advantage of the priority traffic system stood at 16 in response to fire and 11 to first-aid operations. Owing to the system, on average, the response time reduced by 3 min and 50 s in case of fire and by 3 min and 30 s for first aid. There were four complaints registered owing to traffic congestion, and the number of car accidents declined to one from six over the same period in the previous year. Based on these findings, it is safe to say that the priority traffic signal system would be effective for emergency vehicles to capitalize on the golden period if issues identified during the pilot run are resolved.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.6
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• pp.829-843
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• 2017

Subsea tunnel needs to be built over 50 km long to connect between nations and continents. However there are only 19 tunnels longer than 5 km until recently. And there is no history of constructing and operating tunnel longer than 50 km. In Korea, subsea tunnels with a length of more than 50 km are being planned, such as Korea~Japan, Korea~China, Honam~Jeju subsea tunnels. Because of the geographical conditions of Korea, most of these tunnels are inter-contry tunnels. So technology preemption for the subsea tunnel construction is getting more and more important. Most of these subsea tunnels are ultra-long tunnels under high water pressure conditions. So new technologies are required such as ventilation and disaster prevention of high-speed tunnels, securing of structural stability under high pressure conditions, and pressure reduction in high-speed conditions. These technologies are different from those of ground tunnels. Therefore, this paper describes the ultra-long subsea tunnel design under high water pressure of maximum 16 bars through the Honam (land) - Jeju (island) virtual subsea project. We proposed a reasonable solution to various problems such as securing structural stability in high pressure condition and ventilation disaster prevention system of ultra long-tunnel.