• Title/Summary/Keyword: Space Communication

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Performance Comparison of Convolutional Coder and Turbo Coder in a High-Speed Wireless LAN System (고속 무선랜 시스템에서 콘볼루션 부호기 및 터보 부호기를 이용한 성능 비교)

  • 서완우;정연호;하덕호
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.2
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    • pp.258-264
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    • 2004
  • WLAN technologies enable high-speed data transmission in a small space with relatively low cost and power. There are two main standardizations regarding WLAN; namely, IEEE802.11a and ETSI BRAN. Two standards use a radio frequency of 5 ㎓ band and employs OFDM as a transmission mode. OFDM is known to provide high-frequency efficiency as well as high-speed data transmission. In this paper, We use SPW simulation tool and implement the HIPERLAN/2 system. Based on the HIPERLAN/2 system in the SPW platform, the system performance is analyzed and compared with turbo codes in place of a convolutional coder of the HIPERLAN/2 WLAN system. The simulation results show that the performance with the turbo codes (rate 1/3 and 1/4) at a data rate of 12 Mbps shows 3 ㏈ gain over the system with the convolutional codes. At a data rate of 36 Mbps, the performance with the turbo codes is further improved by approximately 4 ㏈.

A Study of Integrated E-Catalog system based on Web Services (Web Services 기반의 통합형 전자 카탈로그 시스템에 관한 연구)

  • 김명진;김창수;김윤기;정회경
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2004.05b
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    • pp.229-233
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    • 2004
  • According as internet and Information-Communication technology develop with the fast speed, Electronic Catalog that is used B2B or B2C electronic commerce is important element middle who can express well special quality of corporation's goods and product most effectively from internet space. But, several problems that creation of Electronic Catalog and standard absence about application that can say as importance technology base in electronic commerce and market newcomers who is constructing each other dissimilar system and take part in electronic commercial transaction can not use Electronic Catalog information exchange and transaction are happening. So that this treatise can use Electronic Catalog document that user who define Electronic Catalog document structure that can process information of goods configurationally and takes part in transaction is defined in electronic commerce hereupon, integration style Electronic Catalog system design and embody. This system did useful information that can not get from various advantage and catalog document such as business all-in-one and interoperability in different environment that Web Services through interlock with Web Services has so that can get Web Services.

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On-line Signature Recognition Using Statistical Feature Based Artificial Neural Network (통계적 특징 기반 인공신경망을 이용한 온라인 서명인식)

  • Park, Seung-Je;Hwang, Seung-Jun;Na, Jong-Pil;Baek, Joong-Hwan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.1
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    • pp.106-112
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    • 2015
  • In this paper, we propose an on-line signature recognition algorithm using fingertip point in the air from the depth image acquired by Kinect. We use ten statistical features for each X, Y, Z axis to react to changes in Shifting and Scaling of the signature trajectories in three-dimensional space. Artificial Neural Network is a machine learning algorithm used as a tool to solve the complex classification problem in pattern recognition. We implement the proposed algorithm to actual on-line signature recognition system. In experiment, we verify the proposed method is successful to classify 4 different on-line signatures.

A Study on Modified Spatial Weighted Filter in Mixed Noise Environments (복합잡음 환경에서 변형된 공간 가중치 필터에 관한 연구)

  • Kwon, Se-Ik;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.1
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    • pp.237-243
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    • 2015
  • In recent image processing, active researches have been made along with rapid development in digital times. However, it is know that the image degradation occurs due to various external factors in the processes of image data processing, transmission and storage, and the main reason of image degradation is due to the noise. Typical methods to remove the noise are CWMF(center weighted median filter), A-TMF(alpha-trimmed mean filter) and AWMF(adaptive weighted median filter) and these methods have a little bit lacking noise reduction characteristics in mixed noise environments. Therefore, in order to remove the mixed noise, image restoration filter processing algorithm was suggested in this paper which processes by applying the median value of the mask and space weighted value after noise judgment. And for the objective judgment, it was compared with existing methods and PSNR(peak signal to noise ratio) was used as a judgment standard.

Event and Service registry system for USN Application Services (USN응용 서비스를 위한 이벤트 및 서비스 레지스트리 시스템)

  • Yeom, Sung-Kun;Kim, Yong-Woon;Yoo, Sang-Keun;Kim, Hyung-Jun;Jung, Hoe-Kyung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.7
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    • pp.1459-1466
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    • 2009
  • In ubiquitous environment, various and amount of sensor data information occur continuously and periodically about thing and user from RHO, sensor network of various space. Such, the users from among many of provider who provide sensor service should find service that themselves is wanted. And when service use, service right to user should be provided. But in the current environment of the USN(Ubiquitous Sensor Network) Application Service, there is no the registry to find these services but only business- oriented UDDI(Universal Description Discovery, and integration). In addition, when service use, service right to user should be provided but current services provided only services one of the conditions or events. Therefore, rules-based processing system of service event that can provide service according various conditions and events is need. In this paper research into service registry for sensor service search with reference to existing UDDI and event processing system for USN application service with reference to event rule based on web service as WS-ECA(Web Service-Event Condition Action).

A Dynamic Service Library Reconfiguration Method of Android Platform (안드로이드 기반 서비스 라이브러리의 동적 재구성)

  • Lee, Young-Seok
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.5
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    • pp.1145-1153
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    • 2013
  • Android mobile platform copy the class files of all applications installed in android platform and keep them into one directory. But to add the service library into a platform, Android must generate a new binary image of platform and replace the platform because android refer the libraries using the memory-mapped file method in a directory. And this memory-mapped file reference method waste the storage space of mobile device because that directory include the duplicated libraries if the libraries refered by application are duplicated, Therefore a dynamic reconfiguration method on android mobile platform is needed to manage the service libraries of application executed on android platform and support the version management and function addition/modification. In this paper, we propose the platform dynamic reconfiguration method to add dynmically the service libraries on android platform.

Improved recognition of 3D objects using nonlinear correlator based on direct pixel mapping in curving-effective integral imaging (커브형 집적 영상에서 DPM 기반의 비선형 상관기를 이용한 3D 물체 인식 향상)

  • Lee, Joon-Jae;Shin, Donghak;Lee, Byung-Gook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.1
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    • pp.190-196
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    • 2013
  • Curved integral imaging is a simple method to display 3D images in space using lens array and provides wide viewing angle. In this paper, we propose a nonlinear 3D correlator based on the direct pixel-mapping (DPM) method in order to improve the recognition performance of 3D target object in curving-effective integral imaging. With this scheme, the elemental image array (EIA) originally picked up from a partially occluded 3-D target object can be converted into a resolution enhanced new EIA by using DPM method. Then, through nonlinear cross-correlations between the reconstructed reference and the target plane images, the improved pattern recognition can be performed from the correlation outputs. To show the feasibility of the proposed method, some preliminary experiments are carried out and results are presented by comparing the conventional method.

Lane Departure Detection Using a Partial Top-view Image (부분 top-view 영상을 이용한 차선 이탈 검출)

  • Park, Han-dong;Oh, Jeong-su
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.8
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    • pp.1553-1559
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    • 2017
  • This paper proposes a lane departure detection algorithm using a single camera equipped in front of a vehicle. The proposed algorithm generates a partial top-view image for a small ROI (region of interest) designated on the top-view space form the image acquired by the camera, detects lanes on the small partial top-view image, and makes a decision on the lane departure by checking overlap between the pre-assigned virtual vehicle and the detected lanes. The proposed algorithm also includes the removal of lines occurred by road symbols (noises) disturbing the lane departure detection between lanes and the prediction of lost lanes using lane information of previous fames. In lane departure detection test using real road videos, the proposed algorithm makes the right decision of 99.0% in lane keeping conditions and 94.7% in lane departure conditions.

The Effect of Background Services on Android Smartphone Performance (백그라운드 서비스가 안드로이드 스마트폰의 성능에 미치는 영향)

  • Ahn, Woo Hyun;Oh, Yunseok;Oh, Jaewon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.22 no.3
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    • pp.399-410
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    • 2018
  • In Android smartphones, many apps are developed as service apps to run in the background. If the memory is insufficient, Android forcibly terminates not only user apps that have not used the CPU for a long time, but also service apps. However, a service app is automatically re-launched after a short period of time, so that it continuously consumes memory space. This paper analyzes the number of running service apps and their memory usage in users' smartphones. The number of service apps accounts for up to 65% of the total number of running apps, and their memory usage accounts for up to 55% of the total memory. Moreover, we investigate the effect of the number of running service apps on the response time of smartphones and apps. As the number of service apps increases, the launching time of user apps increases to 22 times. The booting time and app installation time significantly increase with the number of service apps.

Design of Automatic Guided Vehicle Controller with Built-in Programmable Logic Controller (PLC 내장형 무인 반송차(AGV) 제어기 설계)

  • Lee, Ju-Won;Lee, Byeong-Ro
    • Journal of the Institute of Convergence Signal Processing
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    • v.20 no.3
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    • pp.118-124
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    • 2019
  • Recently, the industrial field has been changed to the smart factory system based on information and communication technology (ICT) in order to improve productivity, quality and customer satisfaction. The most important machine to realize the smart factory is the AGV(automatic guided vehicle) and the adoption of AGV is increasing. Generally, AGV is developed using general purpose PLC(Programmable Logic controller), but the price of AGV is expensive and its volume is large. On the other hand, the industrial field due to space constraints in the workplace is required the low cost AGV which can be minimization, expansion of function, and easily reconfiguration. Therefore, in order to solve these problems, this study is proposed a design method of AGV controller with built-in PLC, and evaluated its performance. In the results of the experimentation, it showed good performance (speed control error = 0.021[m/s], posture control error=2.1[mm]) for the speed and posture control. In this way, when applying the proposed AGV controller in this study to the industrial filed, it is possible to reduce the size and reconfigure at low cost.