• Journal of Ocean Engineering and Technology
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• v.35 no.1
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• pp.91-97
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• 2021

Marine accidents caused by ships have brought about economic and social losses as well as human casualties. Most of these accidents are caused by small and medium-sized ships and are due to their poor conditions and insufficient equipment compared with larger vessels. Measures are quickly needed to improve the conditions. This paper discusses a video-integrated collision prediction and fall detection system to support the safe navigation of small- and medium-sized ships. The system predicts the collision of ships and detects falls by crew members using the CCTV, displays the analyzed integrated information using automatic identification system (AIS) messages, and provides alerts for the risks identified. The design consists of an object recognition algorithm, interface module, integrated display module, collision prediction and fall detection module, and an alarm management module. For the basic research, we implemented a deep learning algorithm to recognize the ship and crew from images, and an interface module to manage messages from AIS. To verify the implemented algorithm, we conducted tests using 120 images. Object recognition performance is calculated as mAP by comparing the pre-defined object with the object recognized through the algorithms. As results, the object recognition performance of the ship and the crew were approximately 50.44 mAP and 46.76 mAP each. The interface module showed that messages from the installed AIS were accurately converted according to the international standard. Therefore, we implemented an object recognition algorithm and interface module in the designed collision prediction and fall detection system and validated their usability with testing.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.11
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• pp.1-8
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• 2008

In this paper, the optical properties of the 54[W] LED module have confirmed by changing the angles of LED modules for street light applications. The angle of LED module changed from the $0[^{\circ}]$ to $60[^{\circ}]$ varying by $20[^{\circ}]$ as horizontal direction ${\ominus}_1$. Morever, the angle of LED module changed from the $0[^{\circ}]$ to $15[^{\circ}]$ varying by $5[^{\circ}]$ as vertical direction ${\ominus}_2$. As a result of simulation, the average illumination was about 17[lux] and the overall illuminance uniformity was 0.29 for a 10.39[m] long and 6[m] wide illuminance area at height of 6[m], which is acceptable for street lighting illumination in the Illuminating Engineering Society(IES) standard.

• IEIE Transactions on Smart Processing and Computing
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• v.6 no.2
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• pp.133-139
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• 2017

Vehicles have increasingly evolved and become intelligent with convergence of information and communications technologies (ICT). Vehicle communications (VC) has become one of the major necessities for intelligent vehicles. However, VC suffers from serious security problems that hinder its commercialization. Hence, the IEEE 1609 Wireless Access Vehicular Environment (WAVE) protocol defines a security service for VC. This service includes Advanced Encryption Standard-Counter with CBC-MAC (AES-CCM) for data encryption in VC. A high-speed AES-CCM crypto module is necessary, because VC requires a fast communication rate between vehicles. In this study, we propose and implement an efficient AES-CCM hardware architecture for high-speed VC. First, we propose a 32-bit substitution table (S_Box) to reduce the AES module latency. Second, we employ key box register files to save key expansion results. Third, we save the input and processed data to internal register files for secure encryption and to secure data from external attacks. Finally, we design a parallel architecture for both cipher block chaining message authentication code (CBC-MAC) and the counter module in AES-CCM to improve performance. For implementation of the field programmable gate array (FPGA) hardware, we use a Xilinx Virtex-5 FPGA chip. The entire operation of the AES-CCM module is validated by timing simulations in Xilinx ISE at a speed of 166.2 MHz.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.413-416
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• 1998

Sensitivity and calibration considerations are most important in the design and implementation of real control systems. Ideally parameter changes due to various causes should not appreciably affect the system's performances. But all the values of physical components of the plants and controllers as well as the relevant environmental conditions change in time, thus the output performance can be deteriorated during the operating span of the system. Naturally the duty of calibration or the prevention of performance deterioration due to excessive component sensitivity should be provided to the control system. In this paper, we propose a digital controller which has the capability of calibration and gain adjustment as well as the execution of control law. Specifically the problems of gain adjustment and offset calibration in the light source and CdS sensor module for position measurement in a flexible link system are considerably resolved. The parameters of measurement module are prone to change due to environmental brightness conditions resulting in poor steady state performance of the overall control system. Thus a proper method is necessary to provide correction to the changed values of gain and offset in the position measurement module. The proposed controller, whenever necessary, measures the open-loop characteristics, andthen calculates the offset and sensor gain correction values based on the prepared standard measurements. It is applied to the control of a flexible link system with the gain and offset calibration porblems in the light sensor module for position to show the applicability.

• New & Renewable Energy
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• v.16 no.1
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• pp.41-46
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• 2020

The share of agrophotovoltaics in the "renewable energy 3020", which is the Korean government policy for revitalizing new and renewable energy, is increasing gradually. In this study, the distribution of solar radiation received by crops growing on virtual farmland under a range of conditions, such as module height, module angle, shading ratio, and module type, was quantified and analyzed using an Ecotect program, which allows insolation analysis during the period from spring to fall. As the module angle increases, transmissive modules increase the amount of solar radiation delivered to the lower farmland. In addition, the difference between 3x12 Cell Type and 4x9 Cells Type, which are types of photovoltaic modules used in practice, was found to be small. The analysis results can be used as a design standard for the future establishment of agrophotovoltaic systems.

• Journal of Korean Society of Steel Construction
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• v.22 no.1
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• pp.99-108
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• 2010

This paper presents the results of a study that aimed to develop a module for auto connection modeling that can be applied to the structural details design and modeling phase. It was established that the steel connection library database from the structural analysis resulted from the consideration of the input parameters of the 3D modeling program and the guidelines for Korean standard steel connections. The module for the auto connection modeling in steel structures was developed by linking it with the established library database through the use of the OpenAPI software to prove that the developed module carried out the modeling of the six story (steel structure) office building. The productivity and efficiency of the module introduction was verified by comparing the conventional process and the proposed process.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.285-288
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• 2005

We propose a novel programmable miniature vision module based on a custom designed analog VLSI (aVLSI) chip. The vision module consists of the optical flow vision sensor embedded with commercial off-the-shelves digital hardware; in our case is the Intel XScale PXA270 processor enforced with a programmable gate array device. The aVLSI sensor provides gray-scale imager data as well as smooth optical flow estimates, thus each pixel gives a triplet of information that can be continuously read out as three independent images. The particular computational architecture of the custom designed sensor, which is fully parallel and also analog, allows for efficient real-time estimations of the smooth optical flow. The Intel XScale PXA270 controls the sensor read-out and furthermore allows, together with the programmable gate array, for additional higher level processing of the intensity image and optical flow data. It also provides the necessary standard interface such that the module can be easily programmed and integrated into different vision systems, or even form a complete stand-alone vision system itself. The low power consumption, small size and flexible interface of the proposed vision module suggests that it could be particularly well suited as a vision system in an autonomous robotics platform and especially well suited for educational projects in the robotic sciences.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.653-659
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• 1994

Human experts have the various own knowledges to be applied in specialized domains. The fact that knowledge itself becomes more critical in the context of textile knowledge with rapid development of new fibers, automated equipments, processes and applications. Diversity of worsted spun yarns, lack of human expertise, and inconsistency among manually generated process plans in consequency of adjustment machine parameters owing to change up raw materials frequently increase the necessity of developing computer aided process planning(CAPP) systems for spinning process. Expert systems offer one of techniques to develop CAPP systems which would behave in a knowledgeable manner. Expert systems are the problem-solving computer program that can reach a level of performance comparable to that of a human expert in some specialized problem domain. This paper is described as job justification module. The job justification module performs to consult with users on which worsted spun yarn manufacturing process planning under the various factors, e.g., raw materials, machine parameters and required yarn counts. Also, the developed module informs the various knowledges relevant process planning. The job justification module offers the control parameters at each process and includes the various standard process plans as database. These knowledges are generated by facts and rules within rule bases.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.2
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• pp.188-194
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• 2010

In this paper, the typical Synthetic Aperture Radar (SAR) image quality parameters and analysis method are defined, and the SAR image analysis tool is presented for SAR image evaluation. The structure of the developed SAR image analysis tool consists of four key modules; point target analysis (PTA) module, distributed target analysis (DTA) module, ambiguity analysis (AMA) module, and NESZ analysis (NESZA) module. The developed tool is able to extract the various SAR system parameters from standard SAR product format files. Based on these extracted system parameters, typical SAR image quality parameters are derived from SAR image data.

• Journal of Ocean Engineering and Technology
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• v.27 no.1
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• pp.9-15
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• 2013

This paper calculates the mating dynamic forces of a semi-submersible offshore structure's topside module, where a hull moored in the sea is combined with a topside module carried by a heavy lift vessel, as a mating installation method. The environmental conditions include various wave directions and wave heights, with constant wind and current speeds. Appropriate ballast and de-ballast plans for the heavy lift vessel and hull of the semi-rig should be performed in order to safely obtain these forces, whereas a fixed platform or the GBS (Gravity based structure) type of offshore structure only needs a ballast plan for the heavy lift vessel. From this paper, the allowable wave height or wave direction for the mating procedure can be investigated based on the standard DAF (Dynamic amplitude factor) of the rules and regulations.