• Title/Summary/Keyword: AP position

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A UE Position Tracking Method for Optical Beamforming Transmission in Visible Light Communications (가시광 통신 시스템에서 광 빔포밍 전송을 위한 유저 단말 추적 방법)

  • Hwang, Yu Min;Kim, Kyung Ho;Song, Yu Chan;Lee, Sang Woon;Kim, Jin Young
    • Journal of Satellite, Information and Communications
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    • v.9 no.2
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    • pp.85-90
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    • 2014
  • In this paper, we propose a novel UE(User Equipment) position tracking algorithm of visible light signals, and analyze BER performance when optical beamforming scheme is applied in VLC(Visible Light Communications) system. The optical beamforming scheme as an interference mitigation method provides good optical channel conditions between UE(Rx) and LED light(Tx), and lead to better BER performance because UE is able to get a better RSSI(Received Signal strength indication) value. For the system BER, the proposed UE position tracking method for optical beamforming transmission demonstrates the performance enhancement compared to a system not applied the optical beamforming transmission scheme, and up to about 5~6dB SNR performance gain is achieved. The results of the paper can be applied to design of various VLC and LBS applications for ubiquitous home network systems.

Adaptive Indoor Localization Scheme to Propagation Environments in Wireless Personal Area Networks (WPAN에서 환경 변화에 적응력 있는 실내 위치 측위 기법)

  • Lim, Yu-Jin;Park, Jae-Sung
    • The KIPS Transactions:PartC
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    • v.16C no.5
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    • pp.645-652
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    • 2009
  • Location-based service providing the customized information or service according to the user's location has attracted a lot of attention from the mobile communication industry. The service is realized by means of several building blocks, a localization scheme, service platform, application and service. The localization scheme figures out a moving target's position through measuring and processing a wireless signal. In this paper, we propose an adaptive localization scheme in an indoor localization system based on IEEE 802.15.4 standard. In order to enhance the localization accuracy, the proposed scheme selects the best reference points and adaptively reflects the changes of propagation environments of a moving target to approximate distances between the target and the reference points in RSS(Received Signal Strength) based localization system using triangulation. Through the implementation of the localization system, we verify the performance of the proposed scheme in terms of the localization accuracy.

Characterization of the din (damage-inducible) and tin (temperature-inducible) Genes Isolated from Escherichia coli (대장균에서 분리된 din (damage-inducible)과 tin (temperature-inducible) 유전자들의 특성)

  • 백경희
    • Korean Journal of Microbiology
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    • v.29 no.6
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    • pp.392-396
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    • 1991
  • Mu d1(Ap lac) bacteriophage can be used to search for genes which are members of a common regulatory network without having to know the functions of the genes in advance. Aim was for obtaining the loci in the SOS network as well as temperature inducible loci. For this purpose, recA441 allele was used. This allele encodes a thermosensitive recA gene product; thus, the recA441 allele can be activated upon temperature upshift without by external DNA damage. Approximately 10, 000 colonies were screened, and then searched for the colonies which expressed .betha.-galactosidase higher level at 42.deg.C than at 30.deg.C. The strains identified fell into two dlasses; (i) ones in which the increased expression was $recA^{+}$ $lexA^{+}$ -dependent, that is, din(damage-inducible) genes which were due to the activation of recA441 allele and (ii) ones in which the increased expression was $recA^{+}$ $lexA^{+}$ -independent and only temperature-inducible, tin genes. Rough mapping position was obtained for these genes.

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Precise Indoor Positioning Algorithm for Energy Efficiency Based on BLE Fingerprinting (에너지 효율을 고려한 BLE 핑거프린팅 기반의 정밀 실내 측위 알고리즘)

  • Lee, Dohee;Lee, Jaeho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.10
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    • pp.1197-1209
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    • 2016
  • As Indoor Positioning System demands due to increased penetration and utilization of smart device, Indoor Positioning System using Wi-Fi or BLE(Bluetooth Low Energy) beacon takes center stage. In this paper, a terminal location of the user is calculated through Microscopic Trilateration using RSSI based on BLE. In the next step, a fingerprinting map appling approximate value of Microscopic Trilateration increases an efficiency of computation amount and energy for Indoor Positioning System. I suggest Indoor Positioning Algorithm based on BLE fingerprinting considering efficiency of energy by conducting precise Trilateration that assure user's terminal position by using AP(Access Point) surrounding targeted fingerprinting cells. And This paper shows experiment and result based on An Suggesting Algorithm in comparison with a fingerprinting based on BLE and Wi-Fi that be used for Indoor Positioning System.

Design Study for Power Integrity in Mobile Devices (모바일 기기의 전원 무결성을 위한 설계 연구)

  • Sa, Gi-Dong;Lim, Yeong-Seog
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.5
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    • pp.927-934
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    • 2019
  • Recently, mobile devices have evolved into small computers with various functions according to user requirements. Careful attention must be paid to the design of the power supply network for the stable operation of the application processor (AP), the wireless communication modem, the high performance camera, and the various interfaces of the mobile device to implement various functions of the mobile device. In this paper, we analyzed and verified the method of optimizing the design parameters such as the position, capacity, and number of decoupling capacitors to meet the target impedance required by the driver IC chip to ensure the stability of the power supply network of mobile devices that should be designed as wiring type due to mounting density limitation. The proposed wired power supply network design method can be applied to various applications including high-speed signal transmission line in addition to mobile applications.

A Composite DorsoPlantar Axial X-ray Projection Study on the Bones of the Whole Infant's Foot (유아 발 전체의 뼈에 대한 합성 전후축방향 엑스선촬영법 연구)

  • Park, Yun;Ahn, Byung-Ju
    • Journal of the Korean Society of Radiology
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    • v.15 no.7
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    • pp.1007-1013
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    • 2021
  • A Study that Cronbach Alpha values were Significantly higher at 0.813 in the Composite AP axial Radiography Signal to Noise Ratio(SNR) for Evaluating uniform Density and Advanced Images of the Entire Foot without overlap with the legs. The Subjective Evaluation ROC also scored a high score of 18 on Foot Calcaneus bone 10° from the Foot Metatarsal bone, and 18 on the Examination by tilting the Sharpness X-ray Tube 20° from the Foot Calcaneus bone. Results show uniform Density and images at 10° rearward of Foot Metatarsal bone and 20° forward of Foot Calcaneus bone during the Composite AP axial Radiography X-ray Examination of Infants.

A deep learning-based approach for feeding behavior recognition of weanling pigs

  • Kim, MinJu;Choi, YoHan;Lee, Jeong-nam;Sa, SooJin;Cho, Hyun-chong
    • Journal of Animal Science and Technology
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    • v.63 no.6
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    • pp.1453-1463
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    • 2021
  • Feeding is the most important behavior that represents the health and welfare of weanling pigs. The early detection of feed refusal is crucial for the control of disease in the initial stages and the detection of empty feeders for adding feed in a timely manner. This paper proposes a real-time technique for the detection and recognition of small pigs using a deep-leaning-based method. The proposed model focuses on detecting pigs on a feeder in a feeding position. Conventional methods detect pigs and then classify them into different behavior gestures. In contrast, in the proposed method, these two tasks are combined into a single process to detect only feeding behavior to increase the speed of detection. Considering the significant differences between pig behaviors at different sizes, adaptive adjustments are introduced into a you-only-look-once (YOLO) model, including an angle optimization strategy between the head and body for detecting a head in a feeder. According to experimental results, this method can detect the feeding behavior of pigs and screen non-feeding positions with 95.66%, 94.22%, and 96.56% average precision (AP) at an intersection over union (IoU) threshold of 0.5 for YOLOv3, YOLOv4, and an additional layer and with the proposed activation function, respectively. Drinking behavior was detected with 86.86%, 89.16%, and 86.41% AP at a 0.5 IoU threshold for YOLOv3, YOLOv4, and the proposed activation function, respectively. In terms of detection and classification, the results of our study demonstrate that the proposed method yields higher precision and recall compared to conventional methods.

Design and Implementation of Indoor Positioning & Shortest Path Navigation System Using GPS and Beacons in Narrow Buildings

  • Sang-Hyeon, Park;Huhnkuk, Lim
    • Journal of the Korea Society of Computer and Information
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    • v.28 no.3
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    • pp.11-16
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    • 2023
  • As techniques for indoor positioning, fingerprinting, indoor positioning method using trilateration, and utilizing information obtained from equipments by Wi-Fi/Bluetooth, etc are common and representative methods to specify the user's indoor position. However, in these methods, an indoor space should be provided with enough space to install a large number of equipment (AP, Beacon). In this paper, we propose a technique that can express the user's location within a building by simultaneously using the GPS signal and the signal transmitted from the beacon in a building structure where the conventional method cannot be applied, such as a narrow building. A shortest path search system was designed and implemented by applying the Dijkstra Algorithm, one of the most representative and efficient shortest path search algorithms for shortest path search. The proposed technique can be considered as one of the methods for measuring the user's indoor location considering the structural characteristics of a building in the future.

CenterNet Based on Diagonal Half-length and Center Angle Regression for Object Detection

  • Yuantian, Xia;XuPeng Kou;Weie Jia;Shuhan Lu;Longhe Wang;Lin Li
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.7
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    • pp.1841-1857
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    • 2023
  • CenterNet, a novel object detection algorithm without anchor based on key points, regards the object as a single center point for prediction and directly regresses the object's height and width. However, because the objects have different sizes, directly regressing their height and width will make the model difficult to converge and lose the intrinsic relationship between object's width and height, thereby reducing the stability of the model and the consistency of prediction accuracy. For this problem, we proposed an algorithm based on the regression of the diagonal half-length and the center angle, which significantly compresses the solution space of the regression components and enhances the intrinsic relationship between the decoded components. First, encode the object's width and height into the diagonal half-length and the center angle, where the center angle is the angle between the diagonal and the vertical centreline. Secondly, the predicted diagonal half-length and center angle are decoded into two length components. Finally, the position of the object bounding box can be accurately obtained by combining the corresponding center point coordinates. Experiments show that, when using CenterNet as the improved baseline and resnet50 as the Backbone, the improved model achieved 81.6% and 79.7% mAP on the VOC 2007 and 2012 test sets, respectively. When using Hourglass-104 as the Backbone, the improved model achieved 43.3% mAP on the COCO 2017 test sets. Compared with CenterNet, the improved model has a faster convergence rate and significantly improved the stability and prediction accuracy.

Radiograph-based Diagnostic Methods for Thoracic and Lumbar Spine Malposition in Chuna Manual Therapy Using Biomarkers (단순 방사선 영상기반 바이오마커를 활용한 흉·요추의 추나의학적 변위 진단 방법)

  • Jin-Hyun Lee;Minho Choi;Joong Il Kim;Jun-Su Jang;Tae-Yong Park
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.18 no.2
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    • pp.1-8
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    • 2023
  • Objectives This study aimed to propose biomarkers for diagnosing Chuna manual therapy (CMT) based on X-ray images in the thoracic and lumbar spines. Methods Through a literature review and expert consensus process, diagnostic biomarkers for CMT were selected based on the listing system in thoracic and lumbar radiograph anterior-posterior (AP) and lateral views. Results 1. Diagnostic biomarkers were derived from four points on the outer contour of the vertebral body in the thoracic and lumbar spine radiograph lateral view, enabling the diagnosis of flexion and extension malposition. 2. Additional diagnostic biomarkers were identified in the thoracic and lumbar radiographAP view, utilizing points on the outer contour of the vertebral body. These biomarkers facilitate the diagnosis of lateral bending. Moreover, biomarkers derived from the innermost point of the pedicle contour allow for the diagnosis of rotation malposition. 3. Furthermore, through the biomarkers proposed in this study, all malpositions of the thoracolumbar spines and complex Type I and II malpositions can be diagnosed in CMT. Conclusions The biomarkers reported in this study consist of minimal points to determine the position of the vertebral body, providing the advantage of simplicity while minimizing potential errors during the CMT diagnostic process. Further clinical research and the development of related programs should be pursued to expand the evidence for CMT.