• Title/Summary/Keyword: Adaptive sampling

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A Fusion Sensor System for Efficient Road Surface Monitorinq on UGV (UGV에서 효율적인 노면 모니터링을 위한 퓨전 센서 시스템 )

  • Seonghwan Ryu;Seoyeon Kim;Jiwoo Shin;Taesik Kim;Jinman Jung
    • Smart Media Journal
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    • v.13 no.3
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    • pp.18-26
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    • 2024
  • Road surface monitoring is essential for maintaining road environment safety through managing risk factors like rutting and crack detection. Using autonomous driving-based UGVs with high-performance 2D laser sensors enables more precise measurements. However, the increased energy consumption of these sensors is limited by constrained battery capacity. In this paper, we propose a fusion sensor system for efficient surface monitoring with UGVs. The proposed system combines color information from cameras and depth information from line laser sensors to accurately detect surface displacement. Furthermore, a dynamic sampling algorithm is applied to control the scanning frequency of line laser sensors based on the detection status of monitoring targets using camera sensors, reducing unnecessary energy consumption. A power consumption model of the fusion sensor system analyzes its energy efficiency considering various crack distributions and sensor characteristics in different mission environments. Performance analysis demonstrates that setting the power consumption of the line laser sensor to twice that of the saving state when in the active state increases power consumption efficiency by 13.3% compared to fixed sampling under the condition of λ=10, µ=10.

ECG Signal Compression based on Adaptive Multi-level Code (적응적 멀티 레벨 코드 기반의 심전도 신호 압축)

  • Kim, Jungjoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.23 no.6
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    • pp.519-526
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    • 2013
  • ECG signal has the feature that is repeated in a cycle of P, Q, R, S, and T waves and is sampled at a high sampling frequency in general. By using the feature of periodic ECG signals, maximizing compression efficiency while minimizing the loss of important information for diagnosis is required. However, the periodic characteristics of such amplitude and period is not constant by measuring time and patients. Even though measured at the same time, the patient's characteristics display different periodic intervals. In this paper, an adaptive multi-level coding is provided by coding adaptively the dominant and non-dominant signal interval of the ECG signal. The proposed method can maximize the compression efficiency by using a multi-level code that applies different compression ratios considering information loss associated with the dominant signal intervals and non-dominant signal intervals. For the case of long time measurement, this method has a merit of maximizing compression ratio compared with existing compression methods that do not use the periodicity of the ECG signal and for the lossless compression coding of non-dominant signal intervals, the method has an advantage that can be stored without loss of information. The effectiveness of the ECG signal compression is proved throughout the experiment on ECG signal of MIT-BIH arrhythmia database.

External Noise Analysis Algorithm based on FCM Clustering for Nonlinear Maneuvering Target (FCM 클러스터링 기반 비선형 기동표적의 외란분석 알고리즘)

  • Son, Hyun-Seung;Park, Jin-Bae;Joo, Young-Hoon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.12
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    • pp.2346-2351
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    • 2011
  • This paper presents the intelligent external noise analysis method for nonlinear maneuvering target. After recognizing maneuvering pattern of the target by the proposed method, we track the state of the target. The external noise can be divided into mere noise and acceleration using only the measurement. divided noise passes through the filtering step and acceleration is punched into dynamic model to compensate expected states. The acceleration is the most deterministic factor to the maneuvering. By dividing, approximating, and compensating the acceleration, we can reduce the tracking error effectively. We use the fuzzy c-means (FCM) clustering as the method to divide external noise. FCM can separate the acceleration from the noise without criteria. It makes the criteria with the data made by measurement at every sampling time. So it can show the adaptive tracking result. The proposed method proceeds the tracking target simultaneously with the learning process. Thus it can apply to the online system. The proposed method shows the remarkable tracking result on the linear and nonlinear maneuvering. Finally, some examples are provided to show the feasibility of the proposed algorithm.

Security Review of B-MAC Communication Protocol (B-MAC통신 프로토콜에서 보안 리뷰)

  • Hong, Jinkeun
    • Journal of Digital Convergence
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    • v.11 no.12
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    • pp.447-452
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    • 2013
  • Berkley Media Access Control (B-MAC) protocol is one of the well-known MAC protocols, which uses adaptive preamble sampling scheme and is designed for wireless sensor networks (WSN). In this paper, we are reviewed about security vulnerability in B-MAC, and analyzed the power which is consumed at each stage of B-MAC protocol according to vulnerability of denial of sleep(DoS) and replay problem. From our analytical results, it can be considered the need of power efficient authentication scheme which provides the reliability, efficiency, and security for a general B-MAC communication. This is the case study of possible DoS vulnerability and its power consumption in B-MAC.

A 10-bit 10MS/s differential straightforward SAR ADC

  • Rikan, Behnam Samadpoor;Abbasizadeh, Hamed;Lee, Dong-Soo;Lee, Kang-Yoon
    • IEIE Transactions on Smart Processing and Computing
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    • v.4 no.3
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    • pp.183-188
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    • 2015
  • A 10-bit 10MS/s low power consumption successive approximation register (SAR) analog-to-digital converter (ADC) using a straightforward capacitive digital-to-analog converter (DAC) is presented in this paper. In the proposed capacitive DAC, switching is always straightforward, and its value is half of the peak-to-peak voltage in each step. Also the most significant bit (MSB) is decided without any switching power consumption. The application of the straightforward switching causes lower power consumption in the structure. The input is sampled at the bottom plate of the capacitor digital-to-analog converter (CDAC) as it provides better linearity and a higher effective number of bits. The comparator applies adaptive power control, which reduces the overall power consumption. The differential prototype SAR ADC was implemented with $0.18{\mu}m$ complementary metal-oxide semiconductor (CMOS) technology and achieves an effective number of bits (ENOB) of 9.49 at a sampling frequency of 10MS/s. The structure consumes 0.522mW from a 1.8V supply. Signal to noise-plus-distortion ratio (SNDR) and spurious free dynamic range (SFDR) are 59.5 dB and 67.1 dB and the figure of merit (FOM) is 95 fJ/conversion-step.

A Study on Adult s Perception of Health Concept (건강개념의 의미에 관한 조사연구)

  • 변영순
    • Journal of Korean Academy of Nursing
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    • v.18 no.2
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    • pp.189-196
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    • 1988
  • Health, a major concept in nursing, has not yet consistent or agreed upon definition. Although effective health care depends on clear communication between health care provider and client clear definition of health would enhance the promotion of quality in health care. There are no agreed definitions or criteria for overall health. An essentialstep would seem to be to determine commonly held meaning about the concept of health. Therefore, the study was aimed at identifying the Adult's perceptions of health concept. The subject's consisting of 312 adults, who were sampled through area sampling from May 10 to May 30,1988. The instruments used for this study were Health Conception Scale, which was developed by Smith, Laffrey's revised and tested its reliability. The data was Analyzed by S.P.S.S. program and the results were as follows ; 1. The results of the reliability test for content of health concept was $\alpha$=.87. 2. The respondents perception of Health Meaning were inclined to emphasize the functional / role performance dimension rather than clinical dimension. 3. The perceptual level of health concept was proved to be significantly different by the variable : age, sex, religion, area marital status. In conclusion, adult's perception of Health Concept is revealed that functional and role performance dimension is more important than other dimensions. Futher study is necessary to clarify the structure of functional, adaptive, eudaimonistic dimension and systematic study with subculture will be and repetitive verification and modification of this tool is demanded.

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Surf points based Moving Target Detection and Long-term Tracking in Aerial Videos

  • Zhu, Juan-juan;Sun, Wei;Guo, Bao-long;Li, Cheng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.11
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    • pp.5624-5638
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    • 2016
  • A novel method based on Surf points is proposed to detect and lock-track single ground target in aerial videos. Videos captured by moving cameras contain complex motions, which bring difficulty in moving object detection. Our approach contains three parts: moving target template detection, search area estimation and target tracking. Global motion estimation and compensation are first made by grids-sampling Surf points selecting and matching. And then, the single ground target is detected by joint spatial-temporal information processing. The temporal process is made by calculating difference between compensated reference and current image and the spatial process is implementing morphological operations and adaptive binarization. The second part improves KALMAN filter with surf points scale information to predict target position and search area adaptively. Lastly, the local Surf points of target template are matched in this search region to realize target tracking. The long-term tracking is updated following target scaling, occlusion and large deformation. Experimental results show that the algorithm can correctly detect small moving target in dynamic scenes with complex motions. It is robust to vehicle dithering and target scale changing, rotation, especially partial occlusion or temporal complete occlusion. Comparing with traditional algorithms, our method enables real time operation, processing $520{\times}390$ frames at around 15fps.

Extended kernel correlation filter for abrupt motion tracking

  • Zhang, Huanlong;Zhang, Jianwei;Wu, Qinge;Qian, Xiaoliang;Zhou, Tong;FU, Hengcheng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.9
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    • pp.4438-4460
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    • 2017
  • The Kernelized Correlation Filters (KCF) tracker has caused the extensive concern in recent years because of the high efficiency. Numerous improvements have been made successively. However, due to the abrupt motion between the consecutive image frames, these methods cannot track object well. To cope with the problem, we propose an extended KCF tracker based on swarm intelligence method. Unlike existing KCF-based trackers, we firstly introduce a swarm-based sampling method to KCF tracker and design a unified framework to track smooth or abrupt motion simultaneously. Secondly, we propose a global motion estimation method, where the exploration factor is constructed to search the whole state space so as to adapt abrupt motion. Finally, we give an adaptive threshold in light of confidence map, which ensures the accuracy of the motion estimation strategy. Extensive experimental results in both quantitative and qualitative measures demonstrate the effectiveness of our proposed method in tracking abrupt motion.

Mipmap-Based Deferred Soft Shadow Mapping (밉맵 기반의 지연된 부드러운 그림자 매핑)

  • Kim, Sunggoo;Lee, Sungkil
    • Journal of KIISE
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    • v.43 no.4
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    • pp.399-403
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    • 2016
  • Deferred Shading is a shading technique that postprocesses pixels in the screen space, following geometry-only rendering passes with depth buffering. Unlike typical shadow mapping techniques, this technique allows us to render shadows from multiple light sources without changing the structure of the rendering pipelines. This paper presents a deferred shadow mapping technique and its extension to soft shadows using mipmapping. Our technique first generates visibility maps from light sources, and blurs the visibility maps for deferred shading. This strategy leads to efficient soft-edged shadows, but does not incorporate depth variation, producing light bleeding to some extent. In order to suppress the light-bleeding artifacts, we also propose a depth-adaptive mipmap sampling technique in the screen space.

3D Object Retrieval Based on Improved Ray Casting Technique (개선된 레이 캐스팅을 이용한 3차원 객체 검색 기법)

  • Lee Sun-Im;Kim Jae-Hyup;Moon Young-Shik
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.43 no.2 s.308
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    • pp.72-80
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    • 2006
  • In this paper, we propose a new descriptor for 3D model retrieval based on shape information. The proposed method consists of two steps including ray casting method and spherical harmonic function, considering geometric properties of model. In the ray casting method, an adaptive sampling is performed for external shape information. By increasing shape information included in the descriptor, we improve the discriminating power of the proposed descriptor. The coefficients of spherical harmonic function are adaptively calculated, considering geometric frequency characteristics. This makes the descriptor more compact and concise without decreasing the retrieval performance. By combining two methods, we achieve more improved retrieval results.