• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.1
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• pp.35-43
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• 2008

Aviation obstacle lights including controller for the safe night aviation service have applied to high voltage transmission line of which height is from $60{\sim}180 m$, Fresnel lens made by Augustine Fresnel have been applied to light houses, These Fresnel lens were applied to aviation obstacle lights and have been universally used, It was reported that Fresnel lens for aviation obstacle light was used in the first place in Korea in 1987, LEDs have recently been applied to aviation obstacle lights, So, the optimum physical design is essential to the design of aviation obstacle light. In this study, optical and three dimensional modeling of LED module and globe lens were performed, And thermal analysis due to LED thermal source and service thermal condition in high voltage transmission line was performed and was analyzed comparing with experiments, The optimum design process of medium intensity LED aviation obstacle lights was constructed with three dimensional modeling, thermal analysis, and thermal experimental technique.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.632-632
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• 2009

The purpose of this study is to present the range of defects mentioned in the Product Liability (PL) and to establish an objective basis and grounds for the analysis of accidents expected to happen by analyzing and presenting the external flame pattern and electrical characteristics of an LED streetlight lamp, a new lighting lamp. From the analysis of the cross-section of a cable carbonized by an external flame, it was observed that the wire's strand and insulation material had solidly adhered, and that greater voids were formed at the surface than at the center. Irregular carbide lumps were formed in the globe directly exposed to the flame, and the globe carbonized by the indirect flame showed characteristics that they had melted and flowed downward. It was found that the forward and backward resistances of the normal LED were approximately 1.74 [$M{\Omega}$] and 140 [$M{\Omega}$], respectively. The lamp burnt by the strong flame exhibited infinite forward and backward resistances and the LED did not emit light. The carbonized LED lamp was gray and exhibited fine delaminations. According to the Product Liability, a product defect signifies a simple product defect. Most of the defects were caused by the lack of stability, and the defect of the product itself occurred during the design and manufacture. The defects in warnings and markings include an insufficiency of handling manuals and warnings, expressive warranty violations, defective markings, etc. In order to prevent an accident resulting from a product, it is necessary to prepare safety warnings and documentation, establish clear-cut lines of liabilities, and subscribe insurances. However, it could be seen that important factors against the Product Liability were product improvement, response to compensation requests and law suits, credit restoration, etc.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.387-392
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• 2020

This paper proposes a flow-rate control system for industrial valves. Industrial valves are used in piping systems to control the flow rate and pressure. In general, valves used in pipelines are classified into globe valves, butterfly valves, and ball valves according to the shape. Motor, hydraulic, and pneumatic systems are used for operating valves. The flow meter should measure the flow rate when configuring the flow-rate control system. On the other hand, because the flow rate of the valve can be expressed by flow coefficient, a control scheme is proposed using the pressure deviation, which measures at the front and rear of the valve. The transfer function for the valve, according to the control input, was estimated using the signal compression method. Based on the induced transfer function, the disturbance observer was designed to improve the command following the performance of the valve stem. The performance of the proposed control method is compared with the flow-rate control result using the flow meter used.

• Journal of Biomedical Engineering Research
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• v.27 no.5
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• pp.250-259
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• 2006

The information of eye movement is used in various fields such as psychology, ophthalmology, physiology, rehabilitation medicine, web design, HMI(human-machine interface), and so on. Various devices to detect the eye movement have been developed but they are too expensive. The general methods of eye movement tracking are EOG(electro-oculograph), Purkinje image tracker, scleral search coil technique, and video-oculograph(VOG). The purpose of this study is to embody the algorithm which tracks the location of the gazing point at a pupil. Two kinds of location data were compared to track the gazing point. One is the reference points(infrared LEDs) which is effected from the globe. Another is the center point of the pupil which is gained with a CCD camera. The reference point was captured with the CCD camera and infrared lights which were not recognized by human eyes. Both of images which were thrown and were not thrown an infrared light on the globe were captured and saved. The reflected reference points were detected with the brightness difference between the two saved images. In conclusion, the circumcenter theory of a triangle was used to look for the center of the pupil. The location of the gazing point was relatively indicated with the each center of the pupil and the reference point.

• Environmental Engineering Research
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• v.23 no.1
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• pp.10-20
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• 2018

Buildings are responsible of major energy consumption globally. In addition, they are linked to thermal comfort. The need to provide comfort becomes more crucial in schools as they are the place where students learn, and develop their skills. This research aims to investigate the energy responsiveness of new and traditional school building design, where major variation in form, amount of external walls and glazing are different. The research focused on indoor microclimate condition of selected schools in the city of Jeddah where the climate is hot and humid using advanced tools for monitoring. The research uses advanced energy equipment to measure several aspects such as floor temperature, roof temperature, globe temperature and other factors which can lead to predictable thermal comfort of users. The findings suggest that a larger area of glazing shielded from sunlight has a greater influence on both indoor condition and general thermal sensation. The finding also suggests that the glazing ratio is a major contributor on indoor thermal pattern which can result in an increase in temperature profile between from $7-10^{\circ}C$. The findings of this research can assist in the improvement in the design of the prototype school building in hot and humid climate.

• Journal of KIBIM
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• v.8 no.2
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• pp.1-9
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• 2018

Nowadays Building Information Modeling (BIM) is a significant source of sharing project information in the construction industry. This method of sharing the information enhances the project understanding among stakeholders. Modeling of information using BIM is becoming an essential part of many construction projects around the globe. Despite rapid adoption of BIM in construction industry still, some sectors of the industry like earthwork have not yet reaped its full benefits. BIM has brought a paradigm shift through identification and integration of the roles and responsibilities of project participants on a single platform. BIM is a 3D model-based process which provides the insight into the efficient project planning and design. The 3D modeling can also be used significantly for the design of temporary structures in an earthwork project. This paper presents the quantity take-off methodology and parametric modeling technique for creating the temporary structures using 3D BIM process. A case study is conducted to implement the proposed temporary structure family design on a real site project. The study presented is beneficial for the earthwork project stakeholders to extract the relevant information using 3D BIM models in a project. It provides an opportunity to calculate the quantity of material required for a project accurately.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.14 no.1
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• pp.70-74
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• 2006

Cospas-Sarsat, an international satellite system for search and rescue, started operating in early 1980's and has been credited with saving thousands of lives since then. Hundreds of thousands of aviators, mariners and land users worldwide are equipped with Cospas-Sarsat distress beacons, which could help save their lives in emergency situations anywhere in the world. This paper outlines the evolution of the system and describes how satellites are constantly circling the globe monitoring for rescue signals, while tracking stations on six continents receive the satellite signals, compute the locations of the distress events and forward the calls for help to the appropriate rescue authorities. Therefore, this paper points out the importance of developing of technologies of Hybrid Aviation Wireless SAR Equipment and also proposes to make it localized.

• KIEAE Journal
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• v.9 no.4
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• pp.3-10
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• 2009

It is not an overstatement to say the factory are the number one cause in creating environmental load. However, only a few studies have been done upto this date on environmentally friendly factory. Thus, This study is to present the characteristics of environmentally friendly factory. A survey of current literatures and cases show the characteristics of environmentally friendly factories and buildings and environment assessment method and plan. To better measure the environmentally friendly qualities as written in literature across the globe, classification system was constructed. The classification system was made and important factors were found based on the precedent paper on environmentally friendly building plan and environment assessment method at building and cases and abroad in the literature review. The classification used 4 different sectors : Land & Transportation, Architectural Planning Technique, Environment & Equipment, Energy & Material. Within these 4 sectors 33 discrete factors are applied to the factory according to literature and case review and specialist advice.

• International Journal of Air-Conditioning and Refrigeration
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• v.9 no.3
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• pp.36-45
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• 2001

During the last decade, an increasing interest in Underfloor Air-Conditioning (UFAC) systems has emerged. The purpose of this paper is to evaluate the indoor environmental performance of office buildings with UFAC system in order to develope the design prototype of this system. The physical measurements and the Interviewing survey of occupant's sensation responses to the environment were carried out. Measurements and survey were made of the thermal environmental factors such as air temperature, relative humidity, air velocity, globe temperature, and the other several environmental factors such as the sound level and the illuminance of working plane, etc. And, the air quality was evaluated by measuring the concentration of suspended particles, carbon monoxide, and carbon dioxide in the room. Furthermore, the paper appraises the various indoor environmental factors of the room by using post-occupancy evaluation (POE) method in office building with UFAC system, and thus, it suggests the basic data for assessing the indoor comfort based on field measurements and survey .

• International Journal of Computer Science & Network Security
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• v.24 no.8
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• pp.174-178
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• 2024

IoT is collection of different "things" which are associated with open web. As all the things are connected to the Internet, it offers convenience to end users for accessing the resources from "Any Where, Any Time" throughout the globe. At the same time, open nature of IoT provides a fertile ground to an intruder for launching different security related threats. If we can no apply proper security safeguards to the IoT System, then it will be not useful to society. Authentication, Encryption, Trust Management and Secure Routing are different domains to offer security in IoT system. Among them, Authentication is very much important security service as it validates device identity before granting access to system services/ resources. Existing IoT Authentication algorithms are fail to verify device identity in unambiguous way. They are vulnerable to different security threats such as Key Stolen threat, MITM threat and Location Spoofing threat. So, it is a demand of time to design an efficient and secure Multi-factor IoT algorithm which can offer better security and validate device identity in unambiguous way.