• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.1106-1108
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• 2009

TETRA(Terrestrial Trunked Radio)는 ETSI(European Telecommunications Standards Institute)에서 지정한 유럽 이동 무선 통신 기반의 표준이다. 본 논문은 TETRA 네트워크에서 트래픽에 따른 모뎀 성능 테스트와 그 결과 분석을 다룬다. TETRA 네트워크에서는 전송 방식에 따라 SDS(Short Data Service)와 PDS(Packet Data Service)로 나뉘게 되는데 본 논문에서는 PEI(Peripheral Equipment Interface)를 이용하여 SDS 전송 방식의 성능측정및 평가를 하였다. 본 측정에서는 최대 140바이트가 전송 가능한 SDS-Type 4가 사용 되었다. 성능 측정은 SDS메시지 데이터의 길이의 차이와 전송간격에 차이를 두어 측정하였다. 전송길이는 10에서 140바이트로 매 10바이트 단위씩 증가하였다. 전송 간격은 각각 0.5초, 1.0초, 1.5초씩 차이를 두어 측정하였고, 전송횟수는 각각 1000번씩 전송하였다. 테스트에 사용된 TETRA 모뎀은 UNIMO 사의 MU-1000MD이 사용되었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.3
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• pp.999-1021
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• 2023

Differential spatial modulation uses the antenna index to transmit information, which improves the spectral efficiency, and completely bypasses any channel side information in the recommended setting. A generalized distributed multiple turbo coded-cooperative differential spatial modulation based on distributed multiple turbo code is put forward and its performances in Rayleigh fading channels is analyzed. The generalized distributed multiple turbo coded-cooperative differential spatial modulation scheme is a coded-cooperation communication scheme, in which we proposed a new joint parallel iterative decoding method. Moreover, the code matched interleaver is considered to be the best choice for the generalized multiple turbo coded-cooperative differential spatial modulation schemes, which is the key factor of turbo code. Monte Carlo simulated results show that the proposed cooperative differential spatial modulation scheme is better than the corresponding non-cooperative scheme over Rayleigh fading channels in multiple input and output communication system under the same conditions. In addition, the simulation results show that the code matched interleaver scheme gets a better diversity gain as compared to the random interleaver.

• Nuclear Engineering and Technology
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• v.55 no.3
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• pp.870-875
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• 2023

In this paper, we analyzed the revised guidance on electromagnetic (EM) interference qualification of Regulatory Guide 1.180 (Revision 2), which is published by the U.S. Nuclear Regulatory Commission for electromagnetic compatibility qualification for nuclear safety, by comparing it with that of the previous version. We confirmed that the test methods and the acceptance criteria of both CE101 and CE102 tests for conductive emission and RE102 test for radiating emission are changed in the recently revised Regulatory Guide 1.180 (Revision 2). Furthermore, we found that the revised Regulatory Guide 1.180 provides flexibility in the use of alternative methods for EM interference (EMI) qualification, in that a mix of the various base-standards is technically allowed. In addition, the primary revision of the updated Regulatory. Guide 1.180 is that MIL-STD-461G is to be adopted as the latest base-standard, instead of MIL-STD-461E. To evaluate the influence on EMI qualification for nuclear safety due to the endorsement of MIL-STD-461G, we thoroughly analyzed the modifications in the acceptance criteria and test methods for EMI qualification, and then validated the analyzed effect on the EMI qualification, which is caused by the revision of MIL-STD-461, by performing electromagnetic simulation for equipment under RE102 test.

• International Journal of Advanced Culture Technology
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• v.11 no.2
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• pp.409-414
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• 2023

In recent years, the emergence of a number of AI image generation software represented by [Midjourney] has brought great impetus to the development of the field of AI-assisted art creation. Compared with the traditional hand-painted digital painting with the aid of electronic equipment, broke the traditional sense of animation character creation logic.This paper analyzes the application of AI technology in the field of animation character design through the practice of two-dimensional animation character . This is having a significant impact on the productivity and innovation of animation design and character modeling. The key results of the analysis indicate that AI technology, particularly through the utilization of "Midjourney,"enables the automation of certain design tasks, provides innovative approaches, and generates visually appealing and realistic characters. In conclusion, the integration of AI technology, specifically the application of "Midjourney," brings a new dimension to animation character design. The utilization of AI image generation software facilitates streamlined workflows, sparks creativity, and improves the overall quality of animated characters. As the animation industry continues to evolve, AI-assisted tools like "Midjourney" hold great potential for further advancement and innovation.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.6
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• pp.473-481
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• 2023

In this study, a simulation system was developed to verify autonomous navigation algorithm in complex maritime traffic areas. In particular, real-world maritime traffic scenario was applied by considering near real-time maritime traffic information provided by Korean e-Navigation service. For this, a navigation simulation system of Unmanned Surface Vehicle (USV) was integrated with an e-Navigation equipment, called Electronic Chart System (ECS). To verify autonomous navigation algorithm in the simulation system, initial conditions including initial position of an own ship and a set of paths for the ship to follow are assigned by an operator. Then, considering real-world maritime traffic information obtained from the service, the simulation is implemented in which the ship repeatedly travels by avoiding surrounding obstacles (e.g., approaching ships). In this paper, the developed simulation system and its application on verification of the autonomous navigation algorithm in complex maritime traffic areas are introduced.

• Korea Trade Review
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• v.46 no.5
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• pp.213-230
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• 2021

China's e-waste enterprises can decompose 150 million sets of e-waste every year, but in fact, only about 50% of the e-waste goes into formal recycling due to the informal recycling of individual small businesses. The purpose of this paper is to put forward the method for users to improve the reuse times through regular e-waste recycling enterprises. This paper constructs the evaluation factors of reuse logistics service through prior research. Exogenous variables are mainly composed of the management system, economics, resources, policies, social perspectives, and service quality. In addition, the authors choose intention to reuse as an endogenous variable. A total of 335 questionnaires were collected to conduct the research with the structural equation modeling. The results reject the hypothesis that economics, resources, and social perspectives have a positive impact on reuse. On the contrary, management systems, policies, and service quality have a positive impact on reuse. Implications were suggested in the last part of the research.

• Mass Spectrometry Letters
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• v.14 no.4
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• pp.147-152
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• 2023

The increasing demand for two-dimensional imaging analysis using optical or electronic microscopic techniques has led to an increase in the use of simple one-dimensional and two-dimensional mass spectrometry imaging. Among these imaging methods, secondary-ion mass spectrometry (SIMS) has the best spatial resolution using a primary ion beam with a relatively insignificant beam diameter. Until recently, SIMS, which uses high-energy primary ion beams, has not been used to analyze molecules. However, owing to the development of cluster ion beams, it has been actively used to analyze various organic molecules from the surface. Researchers and commercial SIMS companies are developing cluster ion beams to analyze biological samples, including amino acids, peptides, and proteins. In this study, a water droplet ion beam for surface analysis was realized. Water droplets ions were generated via electrospraying in a vacuum without desolvation. The generated ions were accelerated at an energy of 10 keV and collided with the target sample, and secondary ion mass spectra were obtained for the generated ions using ToF-SIMS. Thus, the proposed water droplet ion-beam device showed potential applicability as a primary ion beam in SIMS.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.59-67
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• 2024

Current straw mushroom farming in countries with large rice growing areas has great development potential, and was once considered a way to generate additional income and reduce poverty in rural areas. However, currently most people still grow mushrooms using traditional processes, leading to low productivity and unguaranteed output quality. Currently, due to climate change and unusual weather changes, people tend to switch to growing straw mushrooms indoors. In the process of growing straw mushrooms indoors, the design of an automatic control and monitoring system is very important to ensure the growing process is carried out effectively and achieves high yields. In this paper, we propose a system that can automatically control and monitor the humidity and temperature of the indoor straw mushroom growing process and other parameters that can be monitored through a network system using Internet of Things. The control algorithm automatically adjusts the grow house equipment based on feedback from sensors to maintain an optimal environment for growing straw mushrooms. Experimental results show that the straw mushroom growing system with automatically controlled and monitored environmental parameters helps improve efficiency, reduce costs and increase the sustainability of the current straw mushroom growing industry.

• International Journal of Computer Science & Network Security
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• v.24 no.9
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• pp.162-168
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• 2024

VANET (vehicular ad hoc network) refers to the case networks designed for vehicles. Such networks are established among the vehicles which are equipped with communication tools. Within these networks, vehicles are regarded as the network nodes. On time and on schedule transmission of data is of high significance for these networks. In order to accomplish the objective of on-time data transmission, specific electronic equipment is embedded in each vehicle which maintains ad hoc communications among the passengers. Information about traffic, road signs and on-line observation of traffic status can be transmitted via these networks; such data makes it possible for the driver to select the best route to reach his destination. If there are not any infrastructures, two broadcasting approaches can be considered: overflowing and rebroadcasting. The overflowing approach leads to heavy traffic. Hence, the challenge we face is to avoid the broadcasting flood. In this paper, an approach for the management of the broadcasting flood is proposed based on fuzzy theory. The proposed method is assumed to have better performance and efficiency than any other approaches in terms of crash rate, the rate of message success and delay

• Journal of Drive and Control
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• v.21 no.3
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• pp.9-19
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• 2024

Many modern hydraulic excavators now use EPPRVs (Electronic Proportional Pressure Reducing Valves) in their pilot systems to control the spool displacement of the main hydraulic system. However, the performance of these systems is often limited by factors such as magnetic hysteresis, mechanical wear, and transient responses influenced by operating conditions and component installation. This paper presents a pressure feedback controller for excavator pilot systems that utilize EPPRVs. This controller significantly reduces steady-state pressure control errors and mitigates the hysteresis effects commonly seen in traditional open-loop systems. To achieve this, we integrated EPPRVs with the main hydraulic valve and injected a chirp signal into the solenoid current. By doing so, we were able to measure the frequency response of the pilot system across different operating pressures and estimate the system dynamics model. Using these models, we designed a set of PI pressure feedback controllers that are guaranteed to be stable. These controllers were then integrated with a gain scheduler based on a lookup table. Experimental results demonstrate that when the developed pressure feedback controller is incorporated into the conventional open-loop controller, it effectively reduces steady-state pressure control errors and mitigates hysteresis.