• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.5
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• pp.807-816
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• 2021

With the technology of the 4th industrial revolution, network traffic is increasing due to an increase in supply, an increase in demand, and an increase in the complexity of traffic patterns. SDN, a concept in which H/W and S/W are separated in order to efficiently manage such massive traffic, is attracting attention as a next-generation network. A lot of research is being conducted on the merits of applying flexible policies by avoiding the problem of rigid vendor dependency by using the SDN controller implemented with S/W Opensource. Therefore, in this paper, we propose an efficient load balancing technique by grouping through the packet structure of the network layer using the control layer and infrastructure layer of SDN and analyzing the packet delay and reception rate.

• Journal of Digital Convergence
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• v.17 no.10
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• pp.93-102
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• 2019

This paper aims to set the priorities for the cybersecurity strategy of Cambodian government. To this end, we built a AHP research model by adopting 4 factors from the ITU national interests model and selecting 7 strategies from best practices of 8 countries leading the cyber security. Using a questionnaire, 19 experts evaluated Cambodia's cybersecurity strategy priorities. The key policy factors were evaluated in the order of homeland defense, economic welfare, value promotion and favorable world order. Their strategic alternatives were identified in the order of legislation, capacity building, and cyber attack prevention for critical infrastructure. This study will contribute to setting the strategic priorities and feasible action plans to strengthen Cambodia's cybersecurity capabilities.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.1
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• pp.21-30
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• 2022

The restart of scramjet engine is almost impossible in case its unstart happens during engine operation. Therefore, it is essential to prognosticate the scramjet engine unstart phenomena. A numerical simulation of a scramjet engine is conducted to investigate the unstart process of the scramjet engine by adjusting the backpressure at the isolator outlet to the engine analysis environment. The start and unstart of the engine are identified by applying a support vector machine (SVM) through the data measured by wall pressure so that the locations of the pressure sensors most suitable for the unstart detection are selected. And the operation conditions in which the engine is avoid to be unstarted are quantified to perceive the safety margin.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.6
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• pp.1095-1104
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• 2022

The towing cable plays a role in dropping and salvaging the Towed Array Sonar System (TASS) into the water and transmitting the signal (information) detected by the sonar in the water to the probe or surface ship. The towing cable consists of a heavy cable and a lightweight cable in detail. The towing cable for sonar is characterized by high reliability and durability as the underwater environment deteriorates as the operating depth increases. Due to these restrictions, cases designed and manufactured in Korea are extremely rare. The core technology for towing cable design secured through this study is expected to be used in various ways in the defense industry and the private sector.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.5
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• pp.889-896
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• 2022

Data required in a wireless sensor network environment requires more accurate figures as technology advances and its complexity increases. However, in the case of operating a large number of sensor nodes in a large area, the balance between the power consumed and the data quality that can be acquired accordingly should be considered for that purpose. In particular, in complex, densely populated urban areas or military operations with specific goals, location data requires increasingly detailed and high accuracy over a wide range. In this paper, we propose a method of mounting a Global Positioning System(: GPS) only on some of the sensor nodes deployed in the wireless sensor network and improving the error of GPS location data measured on that sensor node through Angle of Arrival(: AoA) and Received Signal Strength Indicator(: RSSI).

• Analytical Science and Technology
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• v.20 no.2
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• pp.155-163
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• 2007

Porosity paper evidence is encountered in case of forgery, kidnapping, fraud and terrorist activity. The present study was designed to evaluate the effect of three chemical reagents (Ninhydrin, 1,8-diazafluoren-9-one (DFO), Iodine fuming) to the quality of developed latent fingerprints on porosity printing papers and newspaper. In case of printing papers, print quality was better with Iodine fuming method than Ninhydrin and DFO treatment to developing latent fingerprints. Developing latent fingerprint on newspapers was achieved with Iodine fuming processing. The processing of Iodine fuming followed by DFO and by using blue light (orange red filter) exhibited better results with Iodine fuming. Enhancement of latent fingerprint detection image using Digital Imaging System was achieved.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1087-1094
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• 2023

Due to the development of technologies, such as big data, cloud, IoT, and AI, The high data throughput is required, and the importance of network flexibility and scalability is increasing. However, existing network systems are dependent on vendors and equipment, and thus have limitations in meeting the foregoing needs. Accordingly, SDN technology that can configure a software-centered flexible network is attracting attention. In particular, a load balancing method based on SDN can efficiently process massive traffic and optimize network performance. In the existing load balancing studies in SDN environment have limitation in that unnecessary traffic occurs between servers and controllers or performing load balancing only after the server reaches an overload state. In order to solve this problem, this paper proposes a method that minimizes unnecessary traffic and appropriate load balancing can be performed before the server becomes overloaded through a method of assigning weights to servers in stages according to server load.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.3
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• pp.609-618
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• 2024

System reliability prediction in the development stage is increasingly crucial to reliability growth management to satisfy its target reliability, since modern system usually takes a form of complex composition and various complicated functions. In most cases of development stage, however, the information available for system reliability prediction is very limited, making it difficult to predict system reliability more precisely as in the production and operating stages. In this study, a system reliability prediction process is considered when the reliability-related information such as SIL (Safety Integrity Level) and MTTFd (Mean Time to Dangerous Failure) is available in the development stage. It is suggested that when the SIL or MTTFd of a system component is known and the field operational data of similar system is given, the reliability prediction could be performed using the scaling factor for the SIL or MTTFd value of the component based on the similar system's field operational data analysis. Predicting a system reliability is then adjusted with the conversion factor reflecting the temperature condition of the environment in which the system actually operates. Finally, the case of applying the proposed system reliability prediction process to a high performance mooring platform is dealt with.

• Journal of fish pathology
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• v.10 no.2
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• pp.143-152
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• 1997

The effect of $\beta$-glucan as an immunostimulant to increase resistance to bacterial diseases by enhancing non-specific defense mechanism in rockfish (Sebastes schlegeli) was examined by oral and bath administration. After oral or bath administration with $\beta$-glucan, the injection challenges with Vibro ordalii, Staphylococcus epidermidis and Edwardsiella tarda were performed to assess $\beta$-glucan efficacy. After injection of V. ordalii, oral administration for 30 days with 1% $\beta$-glucan showed 25% of survival rate. But all control fish died within 3 days after the injection. After injection of S, epidermidis, oral administration group for 20 and 30 days showed a remarkably increased survival rate of 95%. But oral administration of $\beta$-glucan to rockfish did not induce protection against experimental E. tarda infection. $\beta$-Glucan bath administration with or without formalin-killed V. ordalii showed that no protection was observed at 10 days after challenge. The results show that $\beta$-glucan to rockfish was effective to increase survival rate of bacterial infections of S. epidermidis and V. ordalii but not against E. tarda.

• Ocean and Polar Research
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• v.30 no.4
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• pp.427-444
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• 2008

The most important bases of maritime laws in China are laws enacted by Constitution, a legislative institution of National People's Congress and Legislation of NPC Standing Committee. However, in reality, the institution, which become the basis of Chinese marine policy and leads overall maritime affairs, is a State Council of the Chinese central government and many objects of our researches on Chinese marine policy and laws are composed centering on this administration law. Therefore, in understanding Chinese maritime laws, it becomes an important prerequisite to understand relevant laws (statutes), administration law, statutes of local province, mutual authority relationships of these legislative institutions, and interpretation authority regarding laws (statutes). In May 2003, Chinese State Council ratified and declared ${\ll}$Guideline of the national maritime economic development plan${\gg}$ and this is the first macroinstructive document enacted by the Chinese government for promoting maritime economy in integration development. This plan guideline shows very well a new policy and deployment direction of maritime policy in China. China is already striving to lead its maintenance stage of domestic legislation into a new stage under the UN maritime laws agreement system and this is an expression of intention to take national policy regarding the ocean as a new milestone for the national economy through concurrent developments in various fields such as national territory, economy, science technology, national defense, and maritime biology. In this point, Chinese maritime policy and maritime legislation provide lots of indexes of lessons in many parts. In particular, regarding Korea, which has to solve many issues with China in Yellow Sea, East China Sea, and Balhae, we have to realize that we can maximize national interest only with a systematic approach to research on changes of domestic policies and maritime legislation within China. In addition, in understanding Chinese maritime related laws, we have to realize it is an important task to not only understand legislative subjects for mutual creation of order within the entire frame of law orders of China but also to predict and react to direction of policy of Chinese domestic legislation through dynamics of these subjects.