• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.9 no.2
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• pp.138-138
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• 1995

본 논문에서는 지능망설비의 성능평가를 위한 평가모델 분석과 현재 운용 중인 지능망서비스 설비시스템에 적용하여 성능평가 모델 및 평가결과를 제시하였다. 평가 기법에는 시뮬레이션 및 운용해석 방법을 이용하였다. 평가 결과로서, 시뮬레이션과 운용해석 방법의 결과는 대체로 일치하였으며 지능망설비의 지연요소 보다 이용자-망 상호작용시간이 더 큰 영향을 주고 있음을 알 수 있었다. 본 논문에서 제안한 평가모델에서 지능망서비스 설비구조의 특성상 서비스처리용량을 확장할 수 있었고 서비스 성능을 고려한 정보통신설비 계획시 또는 서비스 운용관리시에 유용한 성능예측 기법으로 제공될 수 있으며 지능망서비스 설계시 서비스 성능을 고려한 통신설비 설계에 유용하게 이용되리라 기대된다.

• Proceedings of the KAIS Fall Conference
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• 2004.11a
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• pp.111-113
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• 2004

최근 반도체 제조공정의 많은 부분이 트랙(Track)장비 형태로 구성되어져있다. 이러한 복합제조 장비들은 각 모듈간의 상호 작용이 복잡하고 체제 가능시간도 엄격히 제안되고 있어 각각의 모듈들을 효율적으로 운용하기 위해서 반드시 스케줄러가 필요 되어 진다. 하지만 우리나라에서 대표적 트랙장비로 달수 있는 Wet Station에 대한 스케줄링 분야에 대한 연구는 미약한 편이며 앞으로 많은 연구와 개발이 필요한 시점이다. 본 논문은 Wet Station 장비의 운용 효율성을 극대화할 수 있는 Wet Station 장비 운용방법을 제안하고 평가하는데 그 목적이 있다. 관련 소프트웨어기술은 향후 핵심적인 기술로 대두 대고 있을 뿐만 아니라 다른 LCD공정의 트랙장비, 인라인(In-Line) 장비, 클러스터 툴(Cluster Tool) 효율적 운용면에서 큰 도움이 될 것으로 기대 된다.

• Journal of KIISE:Software and Applications
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• v.30 no.12
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• pp.1185-1192
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• 2003

In the component assembly and composition technique of software architecture, It is operated that the existing composition techniques based on architecture, ACME, Wright etc., used in FIFO with the direct connection structure between components through connector's Role. But, when the non-synchronizing request of components that have different characteristics occurs, the FIFO techniques is applied to the connector is difficult to process and operate effectively because of the high performance component waiting the sequence order if the low performance component is allocated first. Thus, the allocated request process according to the priority considering the characteristics of each call components in connector is necessary to improve the operation of assembled component. In this research, we extend the connector part that is available in multiplex connection structure based on existent Wright specification. For service process requested from component, the connector part is designed and implemented to operating with priority sequence through calculating the weight of CPU use rate, bean requesting process time and memory use rate among the efficiency elements of assembled components. To verify the efficiency if this designed connector, we implemented 20 samples EJB components that have different efficiency characteristics and applied these samples components to designed connector. The operating results with this designed connector show that the efficient operation of whole system is possible though the processing time takes 481ms more than the time of the existing FIFO techniques.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.6
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• pp.9-16
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• 2011

Due to the development and proliferation of ubiquitous technologies and services, various sensor network applications are being appeared on the stage. The needs for algorithms requiring sensor data fusion and complex signal processing with a high-performance processor such as a digital signal processor are also increased. However, it is difficult to use such processor for the low-power sensor network operating with a battery because of power consumption. This paper proposes a hybrid-type sensor module architecture supporting wakeup/sleep software framework for the wireless sensor node and shows the implemented sensor node platform and performances focused on the energy consumption and wakeup time.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.4
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• pp.300-308
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• 2019

For drones to be used for industrial or agricultural applications, it is necessary to increase the payload and endurance. Currently, the payload and endurance are limited by the battery technology for electric powered drones. In addition, charging or replacing the batteries may not be a practical solution at the field that requires near continuous operation. In this paper, a procedure to optimize the power system of an electric hybrid drone that consists of an internal combustion engine, a generator, a battery, and electric motors is presented. The example drone for crop dusting is sized for easy transportation with a maximum takeoff weight of 200 kg. The two main rotors that are mechanically connected to the internal combustion engine provides most of the lift. The drone is controled by four electric motors that are driven by the generator. By analyzing the flow of the energy, a methodology to select the optimum propeller and motor among the commercially available models is described. Then, a procedure of finding the optimum operational condition along with the proper gear reduction ratios for the internal combustion engine based on the test data is presented.

• Journal of the Korean Society for Railway
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• v.19 no.6
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• pp.802-814
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• 2016

This study examines the relationship between the operational turnaround time and the rolling stock requirements. In this study, the operational turnaround time of rolling stock is divided into physical turnback time and waiting time. This paper presents a variety of models and estimation results of the existing studies on operational turnaround time. The proposed estimation model of the operational turnaround time in this study is designed to minimize the operational turnaround time in terminus stations, while the rolling stock requirement is reduced. The developed estimation model was applied in a real-world example, and it was found that the operational turnaround time and the required rolling stocks were lessened compared with the current condition. The method presented in this paper is expected to be utilized in train operational planning and rolling stock routing plans, thereby minimizing the rolling stock requirements of existing railway operating authorities.

• Journal of Advanced Navigation Technology
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• v.24 no.2
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• pp.92-100
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• 2020

Satellite-based argumentation systems (SBAS) is a system that enhances the accuracy, integrity, availability and continuity of GNSS navigation users by using geostationary orbit (GEO) satellites to send correction information and the failures of global navigation satellite system (GNSS) satellites in the form of messages. The correction information provided by SBAS is pseudorange error, satellite orbit error, clock error, and ionospheric delay error at 250 bps. Therefore, A lot of message processing are required for the SBAS navigation. There is a need to reduce SBAS time to first fix (TTFF) for using SBAS navigation in systems with short operating time. In this paper, A-SGNSS operation method was proposed for reducing SBAS TTFF. Also, A-SGNSS TTFF and availability were analyzed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.6
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• pp.714-721
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• 2020

DNN is expanding its use in embedded systems such as robots and autonomous vehicles. For high recognition accuracy, computational complexity is greatly increased, and multiple DNNs are running aperiodically. Therefore, the ability processing multiple DNNs in embedded environments is a crucial issue. Accordingly, multicore based platforms are being released. However, most DNN models are operated in a batch process, and when multiple DNNs are operated in multicore together, the execution time deviation between each DNN may be large and the end-to-end execution time of the whole DNNs could be long depending on how they are allocated to the cores. In this paper, we solve these problems by providing a framework that decompose each DNN into individual layers and then distribute to multicores through a global queue. As a result of the experiment, the total DNN execution time was reduced by 31%, and when operating multiple identical DNNs, the deviation in execution time was reduced by up to 95.1%.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.11
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• pp.1323-1326
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• 2012

In military applications, many radar systems are simultaneously operated at a close range. In particular, the frequency allocation must be executed for operating the homogeneous radar systems at the same time. As many radar systems are simultaneously operated with overlapping frequency bands, interference between systems inevitably occurs. Because interference can degrade radar performance, suppression of interference is a critical issue in radar systems. In this letter, we analyze the interference between two FMCW radars. In addition, time synchronization method between radars using mutual interference is proposed. Experiments are carried out to validate the proposed method. The results demonstrate that the proposed method is suitable for real radar systems.

• Journal of Internet Computing and Services
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• v.15 no.2
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• pp.1-7
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• 2014

This paper presents an analytical method for finding the optimum transmission range in mobile ad hoc networks(MANETs). The results are particularly useful for the operation of military networks, as the transmission range affects the throughput, delay, and battery consumption. Plus, the proposed method allows the optimum transmission range to be determined in advance when deploying combatants with mobile terminals. And we analyze the battery life-time and the optimum transmission range under various propagation scenarios based on Hata propagation model. The proposed method obtains the optimum transmission range in a MANET based on the operational conditions.