• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.765-778
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• 2021

The purpose of this study is to prevent fire accidents in advance by deriving prior knowledge among groups about temporary fire-fighting facilities of workers at construction sites and devising appropriate improvement measures. The findings are as follows.First, in the case of fire extinguishers, statistical attention was paid to the contractor, supervisor, partner worker and fire extinguisher manager between designations. 87% of fire managers and 70% of facility supervisors said fire extinguisher management managers needed to be designated for each type of construction, which requires designation of fire extinguisher management managers, frequently checking and relocating. Second, in the case of simple fire extinguishing facilities, statistical attention was paid to the application of penalties for unauthorized use of fire extinguishing facilities with construction companies, supervisors, and business partners.Third, in the case of emergency alarm measures, statistical attention was paid to the application of emergency alarm sound to temporary broadcasting facilities with construction works, supervisors, and business partners.Fourth, in the case of induction, statistical attention was paid to the application of connection between construction works, supervisors, and partner workers, such as passage guidance, emergency lighting, etc.It was found that 65% of construction workers and 55% of electrical workers had different applications such as aisle guidance and emergency lighting for each type of business partner. In order to resolve blind spots such as evacuation zone guidance due to the structure of the building, it is necessary to easily distinguish the direction of the entrance door from a long distance by applying it in conjunction with passage guidance lights and emergency lighting.

• Journal of Energy Engineering
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• v.27 no.2
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• pp.32-48
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• 2018

Monitoring of energy use should be a priority in order to efficiently manage building energy use. Energy use in buildings can be managed by dividing them into energy sources, uses, and ZONE. By energy source, electricity, gas, fuel, and district heating are supplied to run the building's facilities. The purpose can be divided into five main applications, including cooling, heating, lighting, hot water and ventilation, but not many elevators and electric heaters that are difficult to include in the five applications are classified. ZONE Star refers to the comparison or separate management of areas for which the purpose of the building is similar or different. In addition, energy efficiency management requires control of the temperature, humidity, and people who will be measuring energy in the building, and the recent problem of fine dust should directly affect the ventilation of the building.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.2
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• pp.155-164
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• 2013

Two design techniques for more accurate and more convenient hybrid positioning system with visible light communication (VLC) and ad-hoc wireless network infrastructure are proposed, in order to overcome the problems of high estimation error, high cost, and limited service range of the conventional positioning techniques. First method is based on a non-carrier VLC based hybrid positioning technique for applications involving of low data rate optical sensing and narrow-range visible light reception from transmitter, and long-range positioning. The second method uses a 4 MHz carrier VLC-based hybrid positioning technique for a high data rate optical sensing and wide-range visible light receiving from transmitter, and mid-range positioning applications. In indoor environments with obstacles where there are long-range 7731.4cm and mid-range 2368cm distances between an observer and a target respectively, the hybrid positioning developed with two design techniques are tested, and the proposed system is verified and analyzed in this paper.

• Journal of KIISE:Software and Applications
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• v.28 no.2
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• pp.192-200
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• 2001

본 논문은 조명 변화, 표정 변화, 부분적인 오클루전이 있는 얼굴 영상에 강인하고 적은 메모리양과 계산량을 갖는 효율적인 얼굴 인식 방법을 제안한다. SKKUface(Sungkyunkwan University face)라 명명한 이 방법은 먼저 훈련 영상에 PCA(principal component analysis)를 적용하여 차원을 줄일 때 구해지는 특징 벡터 공간에서 조명 변화, 얼굴 표정 변화 등에 해당되는 공간이 최대한 제외된 새로운 특징 벡터 공간을 생성한다. 이러한 특징 벡터 공간은 얼굴의 고유특징만을 주로 포함하는 벡터 공간이므로 이러한 벡터 공간에 Fisher linear discriminant를 적용하면 클래스간의 더욱 효과적인 분리가 이루어져 인식률을 획기적으로 향상시킨다. 또한, SKKUface 방법은 클래스간 분산(between-class covariance) 행렬과 클래스내 분산(within-class covariance) 행렬을 계산할 때 문제가 되는 메모리양과 계산 시간을 획기적으로 줄이는 방법을 제안하여 적용하였다. 제안된 SKKUface 방법의 얼굴 인식 성능을 평가하기 위하여 YALE, SKKU, ORL(Olivetti Research Laboratory) 얼굴 데이타베이스를 가지고 기존의 얼굴 인식 방법으로 널리 알려진 Eigenface 방법, Fisherface 방법과 함께 인식률을 비교 평가하였다. 실험 결과, 제안된 SKKUface 방법이 조명 변화, 부분적인 오클루전이 있는 얼굴 영상에 대해서 Eigenface 방법과 Fisherface 방법에 비해 인식률이 상당히 우수함을 알 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2519-2523
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• 2003

Ultrasonic sensors are widely used in mobile robot applications to recognize external environments, because they are cheap, easy to use, and robust under varying lighting conditions. In most cases, a single ultrasonic sensor is used to measure the distance to an object based on time-of-flight (TOF) information, whereas multiple sensors are used to recognize the shape of an object, such as a corner, plane, or edge. However, the conventional sequential driving technique involves a long measurement time. This problem can be resolved by pulse coding ultrasonic signals, which allows multi-sensors to be fired simultaneously and adjacent objects to be distinguished. Accordingly, the current presents a new simultaneous coded driving system for an ultrasonic sensor array for object recognition in autonomous mobile robots. The proposed system is designed and implemented using a DSP and FPGA. A micro-controller board is made using a DSP, Polaroid 6500 ranging modules are modified for firing the coded signals, and a 5-channel coded signal generating board is made using a FPGA. To verify the proposed method, experiments were conducted in an environment with overlapping signals, and the flight distances for each sensor were obtained from the received overlapping signals using correlations and conversion to a bipolar PCM-NRZ signal.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.87.2-87.2
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• 2015

Transparent conductors are commonly used in photoelectric devices, where the electric energy converts to light energy or vice versa. Energy consumption devices, such as LEDs, Displays, Lighting devices use the electrical energy to generate light by carrier recombination. Meanwhile, solar cell is the only device to generate electric energy from the incident photon. Most photoelectric devices require a transparent electrode to pass the light in or out from a device. Beyond the passive role, transparent conductors can be employed to form Schottky junction or heterojunction to establish a rectifying current flow. Transparent conductor-embedded heterojunction device provides significant advantages of transparent electrode formation, no need for intentional doping process, and enhanced light-reactive surface area. Herein, we present versatile applications of transparent conductors, such as NiO, ZnO, ITO in photoelectric devices of solar cells and photodetectors for high-performing UV or IR detection. Moreover, we also introduce the growth of transparent ITO nanowires by sputtering methods for large scale application.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.2
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• pp.137-143
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• 2015

This paper presents the intra capacitance modeling based on the winding method and section bobbin for CM choke capable of EMI attenuation of broad bands from lower to higher frequency bands and high frequency type common-mode choke capable of EMI attenuation of high frequency band used in the EMI Block of LED-TV SMPS. The case of high frequency type CM choke can be explained by the parasitic capacitance of three types of CM choke. The winding method of section bobbin type is smaller than the others. The first resonant frequency of the proposed CM choke tends to increase as the parasitic capacitance becomes small and its impedance characteristics improved performance as the first resonant frequency increases. The CM chokes of the proposed section bobbin type shows that in the future, the method may have practical use in LED/LCD-TV SMPS and in several applications, such as LED lighting, adapters, and so on.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.312-315
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• 2003

In recent, there have been several developments in lamp technology that promise savings in electrical power consumption and improved quality of the lighting space. Above all, the advantage of ring-shaped electrodeless fluorescent lamp is the removal of internal electrodes and heating filaments that are a light-limiting factor of conventional fluorescent lamps. The ring-shaped electrodeless lamp is intended as a high efficacy replacement for the incandescent reflector lamp in many applications. Therefore, the life time of ring-shaped electrodeless fluorescent lamps is substantially higher than that of conventional fluorescent lamps and last up to 60,000 hours. In this paper, maxwell 3D finite element analysis program (Ansoft) was used to obtain electromagnetic properties associated with the coil and nearby structures. The electromagnetic emitting properties were presented by 3D simulation software operated at 250[kHz] and some specific conditions.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.967_968
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• 2009

For lighting application, high-power LED nowadays is driven at 350mA and a sensing resistor is used to provide feedback for LED-current regulation. This method adds an IR drop at the output branch, and limits power efficiency as LED current is large and keeps increasing. In this paper, a power efficient LED-current sensing circuit is proposed. The circuit does not use any sensing resistor but extracts LED-current information from the output capacitor of the driver. Controlling the brightness of LEDs requires a driver that provides a constant, regulated current. In one case, the converter may need to step down the input voltage, and, in another, it may need to boost up the output voltage. These situations often arise in applications with wide-ranging ""dirty"" input power sources, such as automotive systems. And, the driver topology must be able to generate a large enough output voltage to forward bias the LEDs. So, to provide this requirements, 13W prototype Buck-Boost Converter is used.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.11
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• pp.1028-1036
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• 2004

Ultrasonic sensors are widely used in mobile robot applications to recognize external environments by virtue that they are cheap, easy to use, and robust under varying lighting conditions. In most cases, a single ultrasonic sensor is used to measure the distance to an object based on time-of-flight (TOF) information, whereas multiple sensors are used to recognize the shape of an object, such as a comer, plane, or edge. However, the conventional sequential driving technique involves a long measurement time. This problem can be resolved by pulse coding of ultrasonic signals, which allows multi-sensors to be emitted simultaneously and adjacent objects to be distinguished. Accordingly, this paper presents a new simultaneous coded driving system for an ultrasonic sensor array for object recognition in autonomous mobile robots. The proposed system is designed and implemented. A micro-controller unit is implemented using a DSP, Polaroid 6500 ranging modules are modified for firing the coded signals, and a 5-channel coded signal generating board is made using a FPGA. To verify the proposed method, experiments were conducted in an environment with overlapping signals, and the flight distances fur each sensor were obtained from the received overlapping signals using correlations and conversion to a bipolar PCM-NRZ signal.