• 대한의용생체공학회:의공학회지
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• 제35권2호
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• pp.26-34
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• 2014

Little information is available about the characteristics in revolution gait of hemiplegic elderly, which is frequently represented in daily life. It is also hard to elucidate purely the characteristics due to hemiplegia because of no consideration of aging factors. The aim of study is to identify the alteration characteristics of lower extremity joint angles in both straight and revolution gaits together due to hemiplegia through comparing healthy with hemiplegic elderly. Following Institutional Review Board approval, twelve healthy and hemiplegic elderly were participated and the center of body mass (COM) and lower extremity joint angles were measured during straight and revolution gaits using a computer-aided video motion capture system. The results showed that the gait characteristics were generally altered in both straight and revolution gaits due to hemiplegia (p < 0.05). The gait characteristics were then different between the straight and revolution gaits each other. This study may be valuable by identifying for the first time the alterations of the lower extremity joint angles in both straight and revolution gaits due to pure hemiplegia through comparing healthy elderly with hemiplegic elderly.

• IEIE Transactions on Smart Processing and Computing
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• 제3권3호
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• pp.110-117
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• 2014

This paper reports a depth-adaptive sharpness adjustment algorithm for stereoscopic perception improvement, and presents its field-programmable gate array (FPGA) implementation results. The first step of the proposed algorithm was to estimate the depth information of an input stereo video on a block basis. Second, the objects in the input video were segmented according to their depths. Third, the sharpness of the foreground objects was enhanced and that of the background was maintained or weakened. This paper proposes a new sharpness enhancement algorithm to suppress visually annoying artifacts, such as jagging and halos. The simulation results show that the proposed algorithm can improve stereoscopic perception without intentional depth adjustments. In addition, the hardware architecture of the proposed algorithm was designed and implemented on a general-purpose FPGA board. Real-time processing for full high-definition stereo videos was accomplished using 30,278 look-up tables, 24,553 registers, and 1,794,297 bits of memory at an operating frequency of 200MHz.

• Structural Engineering and Mechanics
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• 제32권6호
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• pp.787-809
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• 2009

Recent interest in the use of wireless sensor networks for structural health monitoring (SHM) is mainly due to their low implementation costs and potential to measure the responses of a structure at unprecedented spatial resolution. Approaches capable of detecting damage using distributed processing must be developed in parallel with this technology to significantly reduce the power consumption and communication bandwidth requirements of the sensor platforms. In this investigation, a damage detection system based on a distributed processing approach is proposed and experimentally validated using a wireless sensor network deployed on two laboratory structures. In this distributed approach, on-board processing capabilities of the wireless sensor are exploited to significantly reduce the communication load and power consumption. The Damage Location Assurance Criterion (DLAC) is used for localizing damage. Processing of the raw data is conducted at the sensor level, and a reduced data set is transmitted to the base station for decision-making. The results indicate that this distributed implementation can be used to successfully detect and localize regions of damage in a structure. To further support the experimental results obtained, the capabilities of the proposed system were tested through a series of numerical simulations with an expanded set of damage scenarios.

• 한국전자통신학회논문지
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• 제9권11호
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• pp.1255-1266
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• 2014

본 논문에서는 오픈 모바일 플랫폼인 안드로이드를 리눅스 커널을 기반으로 하는 ARM Cortex-A8 Core를 사용한 SAMSUNG의 S5PV210 CPU를 장착한 MPU 모듈, Base 보드 모듈 및 센서 모듈을 제작하여 실시간 프레임워크를 설계함으로서 효율적인 산업용 제어를 가능하게 하였다. 센서 모듈에서 획득한 온도 및 습도 데이터는 하이브리드 어플리케이션을 개발함으로서 Web Server를 통하여 데이터베이스에 저장된 후 클라이언트 User가 온도 및 습도 데이터를 스마트 폰에서 확인 함으로서 실시간 프레임워크 설계의 적합성 및 타당성을 검증한다.

• Smart Structures and Systems
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• 제6권5_6호
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• pp.689-709
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• 2010

In this paper, a low cost, low power but multifunctional wireless sensor node is presented for the impedance-based SHM using piezoelectric sensors. Firstly, a miniaturized impedance measuring chip device is utilized for low cost and low power structural excitation/sensing. Then, structural damage detection/sensor self-diagnosis algorithms are embedded on the on-board microcontroller. This sensor node uses the power harvested from the solar energy to measure and analyze the impedance data. Simultaneously it monitors temperature on the structure near the piezoelectric sensor and battery power consumption. The wireless sensor node is based on the TinyOS platform for operation, and users can take MATLAB$^{(R)}$ interface for the control of the sensor node through serial communication. In order to validate the performance of this multifunctional wireless impedance sensor node, a series of experimental studies have been carried out for detecting loose bolts and crack damages on lab-scale steel structural members as well as on real steel bridge and building structures. It has been found that the proposed sensor nodes can be effectively used for local wireless health monitoring of structural components and for constructing a low-cost and multifunctional SHM system as "place and forget" wireless sensors.

• Smart Structures and Systems
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• 제6권5_6호
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• pp.661-673
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• 2010

This paper presents recent developments in an extremely compact, wireless impedance sensor node (the WID3, $\underline{W}$ireless $\underline{I}$mpedance $\underline{D}$evice) for use in high-frequency impedance-based structural health monitoring (SHM), sensor diagnostics and validation, and low-frequency (< ~1 kHz) vibration data acquisition. The WID3 is equipped with an impedance chip that can resolve measurements up to 100 kHz, a frequency range ideal for many SHM applications. An integrated set of multiplexers allows the end user to monitor seven piezoelectric sensors from a single sensor node. The WID3 combines on-board processing using a microcontroller, data storage using flash memory, wireless communications capabilities, and a series of internal and external triggering options into a single package to realize a truly comprehensive, self-contained wireless active-sensor node for SHM applications. Furthermore, we recently extended the capability of this device by implementing low-frequency analog-to-digital and digital-to-analog converters so that the same device can measure structural vibration data. The compact sensor node collects relatively low-frequency acceleration measurements to estimate natural frequencies and operational deflection shapes, as well as relatively high-frequency impedance measurements to detect structural damage. Experimental results with application to SHM, sensor diagnostics and low-frequency vibration data acquisition are presented.

• 패션비즈니스
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• 제25권4호
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• pp.151-160
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• 2021

The purpose of this study was to investigate whether there were improvements on balance when both ankle-jointed calf muscles and hip muscles, which affect balance capabilities, were activated through taping techniques and EMS. In this study, the One Leg Standing Test, a static balance test, was conducted by experimenting on a flat floor, foam pad, and a stretching board with a gradient of 20 degrees, respectively, to study static balance capabilities in different situations. Nine healthy men in their 20s were measured five times every five minutes considering muscle fatigue, and the difference between each variable was analyzed through post-test using nonparametric statistical analysis. Our results showed an equal increase in static balance capability was similar when EMS was applied only to calf muscles and only to hip muscles. Notably most improvements were seen when wearing calf supporters and taping technology pants, and applying EMS together. It was also found that the difference between EMS electric stimulation and balance capability was greater when wearing and applying supporters and taping technology pants. Based on the results of the present study, a muscle support band and EMS of taping techniques can improve balance capabilities. These findings are expected to form a basis for solutions Improving the balance capabilities

• 한국중재학회지:중재연구
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• 제31권2호
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• pp.47-76
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• 2021

India is one of the fast growing country in the world. For the acceleration of economic growth of India, it is indispensable for Indian government to construct infrastructure, such as railroad, airport, harbor, power plant, and water management system. For example, Modi, prime minister of federal government of India proclaimed that Indian government plans to construct 100 smart cities in 2015. In recent times, India is expected to be the largest recipient of Public-Private Partnership(PPP) type projects in the world. Owing to PPP, it is possible for India to pursue her objective to transform the whole economy into digital economy beyond agricultural society. One of major problem related with implementation of PPP type projects is the growth of disputes concomitant to the rising phenomena of PPP type projects in order to build infrastructure in India. Because of this, non-negligible number of projects has been cancelled during last two decades. This study investigates seven failure cases of PPP in India. Those include Nabi mumbai airport, Dabhol power plant, Munbai water project, and Kolkata subway project. Main types of dispute resolution are mediation or conciliation, dispute review board, arbitration, expert adjudication in PPP.

• 한국멀티미디어학회논문지
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• 제22권2호
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• pp.167-177
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• 2019

Even though so much progresses have been achieved in Multiple Object Tracking (MOT), most of reported MOT methods are not still satisfactory for commercial embedded products like Pan-Tilt-Zoom (PTZ) camera. In this paper, we propose a real-time multiple pedestrians tracking method for embedded environments. First, we design a new light weight convolutional neural network(CNN)-based pedestrian detector, which is constructed to detect even small size pedestrians, as well. For further saving of processing time, the designed detector is applied for every other frame, and Kalman filter is employed to predict pedestrians' positions in frames where the designed CNN-based detector is not applied. The pose orientation information is incorporated to enhance object association for tracking pedestrians without further computational cost. Through experiments on Nvidia's embedded computing board, Jetson TX2, it is verified that the designed pedestrian detector detects even small size pedestrians fast and well, compared to many state-of-the-art detectors, and that the proposed tracking method can track pedestrians in real-time and show accuracy performance comparably to performances of many state-of-the-art tracking methods, which do not target for operation in embedded systems.

• 한국산업융합학회 논문집
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• 제22권3호
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• pp.373-379
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• 2019

Nowadays, the IoT portable electronic devices have become more useful and diverse, so they require various supply voltage levels to operate. This paper presents a DC-DC buck converter with pulse width modulation (PWM) for portable electronic devices. The proposed step-down DC-DC converter consists of passive elements such as capacitors, inductors, and resistors and an integrated chip (IC) for signal control to reduce power consumption and improves ripple voltage with the resolution. The proposed DC-DC converter is simulated and analyzed in PSPICE circuit design platform, and implemented on the prototype PCB board with a Texas Instruments LM5165 IC. The proposed buck converter is showed 92.6% of peak efficiency including a load current range of 4-10 mA, 3.29 mV of the voltage ripple at 5 V output voltage for the supply voltage 12 V. Measured and Simulated power efficiency are made good agreement with each other.