• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.3
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• pp.54-65
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• 2022

We are developing a compact ignition device that can provide a multi-ignition capability for an upper stage methane engine of a two staged small satellite launch vehicle. Firstly, the multi-ignition device is designed and built as an integral part of an additively manufactured mixing head. Secondly, the ignition device requires no separate high-pressure vessels to store ignition propellants as they are branched out from the main feed lines for the mixing head. We performed experiments at various levels, including igniter autonomous tests, thrust chamber ignition and combustion tests on the new compact ignition device which is integrated in the thrust chamber of one-tonf class liquid oxygen/liquid methane engine, and confirmed stable ignition performance.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.6
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• pp.250-265
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• 2022

Positive effects such as significantly reducing traffic accidents caused by human error can be expected by the introduction of Automated vehicles (AV). However, as new traffic safety issues are expected to occur in the future due to errors in H/W or S/W of autonomous vehicles and lack of its function, it is necessary to establish a scenario to evaluate the driving safety of AV. Therefore, in this study, functional scenario was developed to evaluate the driving safety of AV based on traffic accident data of the National Police Agency. Using the GIS program, QGIS, traffic accident data that occurred in the toll gate and ramp sections of expressway were extracted and accident summary items were checked to classify the types of accident. In addition, based on the results of accident type classification, functional scenario were developed that contains various dangerous situations in the tollgate and ramp sections.

• Journal of IKEEE
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• v.27 no.1
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• pp.1-11
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• 2023

Path driving tests are necessary for the development of self-driving cars or robots. These tests are being conducted in simulation as well as real environments. In particular, for development using reinforcement learning and deep learning, development through simulators is also being carried out when data of various environments are needed. To this end, it is necessary to utilize not only manually designed paths but also various randomly and automatically designed paths. This test site design can be used for actual construction and manufacturing. In this paper, we introduce a method for randomly generating a driving test path consisting of a combination of arcs and segments. This consists of a method of determining whether there is a collision by obtaining the distance between an arc and a line segment, and an algorithm that deletes part of the path and recreates an appropriate path if it is impossible to continue the path.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.6 no.8
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• pp.577-584
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• 2016

UAV(Unmaned Aerial Vehicle), which is autonomous flight without pilots. Recently, UAV is being applied to various fields such as video recording, aerial photogrammetry. In particular, UAV is getting a lot of attention in the field of space-related information because of it's data acquisition speed and economic feasibility. But analytical study of an unmanned air-side technologies are lacking. In this study, the research of equipment for the unmanned aerial surveys and UAV technologies and trend analysis for generation of terrain model and ortho image effectively were performed. As a result, the ways to improve the utilization field of unmanned aerial surveying and processing of fixed-wing and rotary-wing unmanned aircraft. were suggested. If analytical research on generation of terrain models and ortho image will be performed, production efficiency of the geospatial information industry is expected to be significantly increased.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.3
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• pp.155-164
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• 2023

About 75% of vessel collision accidents are caused by human error, which causes enormous economic loss, environmental pollution, and human casualties, thus research on automatic collision avoidance of vessels is being actively conducted. In addition, vessels must comply with the COLREGs rules stipulated by IMO when performing collision avoidance with other vessels in motion. In this study, the collision risk was calculated by estimating the position and velocity of other vessels through the Probabilistic Data Association Filter (PDAF) algorithm based on RADAR sensor data. When a collision risk is detected, we propose an event-triggered Nonlinear Model Predict Control (NMPC) algorithm that geometrically creates waypoints that satisfy COLREGs and follows them. To verify the proposed algorithm, simulations through MATLAB are performed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.400-403
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• 2021

Algorithms for predicting the optimal route of vehicles are being actively sudied with the recent development of autonomous driving technology. Companies such as SK, Kakao, and Naver provide services that navigate the optimal route. They predicts the optimal path with information from the users in real time. However, they can predict the optimal route, but not optimal lane route. We proposes a system that navigates the optimal lane path with coordinates data from vehicles using Lidar sensor. The proposed method is a system that guides smooth lanes by acquiring time series coordinate data of a vehicle after performing the Lidar-based object detection method. we demonstrates the performance using actual acquired data from the experimental results.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.569-576
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• 2023

An agricultural drones are gradually increasing in utilization due to economic efficiency, and consist of a main frame in charge of flying spray system in charge of moving pesticide to control targets. Therefore, the environment and characteristics of crops should be considered when controlling pesticides using drones and conditions such as systematic flying altitude of flight, speed, and spray time should be changed accordingly. However, pest control work using agricultural drones has different spray effects depending on level the operation proficiency and spray impact. In addition, there are variations in operating standards and control efficiency for agricultural drones, which hinder the distribution of agricultural control drones in the field of pest control work. Therefore, this study attempts to identify the spraying characteristics of agricultural drones, apply the effective spraying time, interval and experimentally verify the system that can calculation of spray area compared to previous studies. Through this experimental verification, it is intended to apply the optimal control process by minimizing the obstacles to pest control work by applying the operation method and systematic figures to agricultural drones.

• The Journal of the Convergence on Culture Technology
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• v.9 no.2
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• pp.575-580
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• 2023

This study was prevent the decrease in crop output by insect pests and spraying by application uniformity. A flight level 4 m height and 4-5 m/sec. speed are difficult to maintain with a agricultural drone for aerial application, which has been affected by the methods or environmental factors, such as changes in the wind. Therefore, which can allow a controlled application width and spray rate automatically and verified experimentally using drone. The sprayed particles began to decrease from about 3.75 m on the left and right sides of the spray nozzle. According to the number of particles, the effective spraying width was observed to be about 7.5 m, and it was verified that the proposed spraying system was effective in uniform control system.

• Journal of English Language & Literature
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• v.56 no.6
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• pp.1361-1378
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• 2010

This paper argues that it is possible to construct an analogy of the literary fragment to an organic individual on the basis of an autonomous system of organic unity by reading William Wordsworth's ways of self-writing in The Prelude. The organicity of a fragment is borrowed from Friedrich Schlegel's theoretic and literary approach to the Romantic fragment. Focusing primarily on the two "spots of time" in Book Twelfth, I attempt to formulate a reciprocal relationship between a work of art and a literary autobiographer in terms of the self-generativity of the fragment. To be precise, both the fragment and the autobiographical project presuppose and at the same time depend on the engendering force of an organic unity and its resistance to discontinuity, which ironically affirms the persistent threat of disruption and death. Rewriting traumatic childhood experiences as rites of passage into adulthood, the two specified "spots of time" show the dominant mode of memory operative in the poem. Asserting the prominence of the individual as the very vehicle of realizing universal humanity, Wordsworth tries to re-form his individuality grounded in his childhood memories in a literary fashion. Under the premise that the poet is remembered by his posterity, The Prelude is constituted and reconstituted in conjunction with different versions of each memory. The poem also marks the poet's unachieved project of writing a philosophical poem, namely, The Recluse; for this very reason, The Prelude, which is complete in itself, points to an eternal work in progress, turning the truth of every fragment complete in its incompletion. As a trope of fragmentation, an autobiographical individuality is reformed in the poet's process of writing and re-visioning while simultaneously being dispersed once again between words, sentences, and pages.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.1049-1055
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• 2023

The utilization of agricultural drones for pest control operations has been increasing due to its economic efficiency. However, variations in the effectiveness of these operations occur depending on the operator's proficiency. In this study, we applied a smart operating mode to overcome the limitations of manual flight mode and proposed a numerical model. Through comparative validation with prior research, we conducted experimental verification. As a result, we determined the spray time and calculation of spray area for each drone model. We selected a drone for pest control with a high similarity to the numerical model and verified it experimentally. Through this, we confirmed that the application of the smart operating mode is more effective in terms of calculation of spray area and operational efficiency compared to manual flight mode.