• Title/Summary/Keyword: embedded system

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In Vivo Dosimetry with MOSFET Detector during Radiotherapy (방사선 치료 중 MOSFET 검출기를 이용한 체표면 선량측정법)

  • Kim Won-Taek;Ki Yong-Gan;Kwon Soo-Il;Lim Sang-Wook;Huh Hyun-Do;Lee Suk;Kwon Byung-Hyun;Kim Dong-Won;Cho Sam-Ju
    • Progress in Medical Physics
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    • v.17 no.1
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    • pp.17-23
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    • 2006
  • In Vivo dosimetry is a method to evaluate the radiotherapy; it is used to find the dosimetric and mechanical errors of radiotherapy unit. In this study, on-line In Vivo dosimetry was enabled by measuring the skin dose with MOSFET detectors attached to patient's skin during treatment. MOSFET dosimeters were found to be reproducible and independent on beam directions. MOSFET detectors were positioned on patient's skin underneath of the dose build-up material which was used to minimize dosimetric error. Delivered dose calculated by the plan verification function embedded in the radiotherapy treatment planning system (RTPs), was compared with measured data point by point. The dependency of MOSFET detector used in this study for energy and dose rate agrees with the specification provided by manufacturer within 2% error. Comparing the measured and the calculated point doses of each patient, discrepancy was within 5%. It was enabled to verify the IMRT by using MOSFET detector. However, skin dosimetry using conventional ion chamber and diode detector is limited to the simple radiotherapy.

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Design Space Exploration of Embedded Many-Core Processors for Real-Time Fire Feature Extraction (실시간 화재 특징 추출을 위한 임베디드 매니코어 프로세서의 디자인 공간 탐색)

  • Suh, Jun-Sang;Kang, Myeongsu;Kim, Cheol-Hong;Kim, Jong-Myon
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.10
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    • pp.1-12
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    • 2013
  • This paper explores design space of many-core processors for a fire feature extraction algorithm. This paper evaluates the impact of varying the number of cores and memory sizes for the many-core processor and identifies an optimal many-core processor in terms of performance, energy efficiency, and area efficiency. In this study, we utilized 90 samples with dimensions of $256{\times}256$ (60 samples containing fire and 30 samples containing non-fire) for experiments. Experimental results using six different many-core architectures (PEs=16, 64, 256, 1,024, 4,096, and 16,384) and the feature extraction algorithm of fire indicate that the highest area efficiency and energy efficiency are achieved at PEs=1,024 and 4,096, respectively, for all fire/non-fire containing movies. In addition, all the six many-core processors satisfy the real-time requirement of 30 frames-per-second (30 fps) for the algorithm.

Volumetric accuracy of cone-beam computed tomography

  • Park, Cheol-Woo;Kim, Jin-ho;Seo, Yu-Kyeong;Lee, Sae-Rom;Kang, Ju-Hee;Oh, Song-Hee;Kim, Gyu-Tae;Choi, Yong-Suk;Hwang, Eui-Hwan
    • Imaging Science in Dentistry
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    • v.47 no.3
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    • pp.165-174
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    • 2017
  • Purpose: This study was performed to investigate the influence of object shape and distance from the center of the image on the volumetric accuracy of cone-beam computed tomography (CBCT) scans, according to different parameters of tube voltage and current. Materials and Methods: Four geometric objects(cylinder, cube, pyramid, and hexagon) with predefined dimensions were fabricated. The objects consisted of Teflon-perfluoroalkoxy embedded in a hydrocolloid matrix (Dupli-Coe-Loid TM; GC America Inc., Alsip, IL, USA), encased in an acrylic resin cylinder assembly. An Alphard Vega Dental CT system (Asahi Roentgen Ind. Co., Ltd, Kyoto, Japan) was used to acquire CBCT images. OnDemand 3D (CyberMed Inc., Seoul, Korea) software was used for object segmentation and image analysis. The accuracy was expressed by the volume error (VE). The VE was calculated under 3 different exposure settings. The measured volumes of the objects were compared to the true volumes for statistical analysis. Results: The mean VE ranged from -4.47% to 2.35%. There was no significant relationship between an object's shape and the VE. A significant correlation was found between the distance of the object to the center of the image and the VE. Tube voltage affected the volume measurements and the VE, but tube current did not. Conclusion: The evaluated CBCT device provided satisfactory volume measurements. To assess volume measurements, it might be sufficient to use serial scans with a high resolution, but a low dose. This information may provide useful guidance for assessing volume measurements.

A Study on the Retentive Force of Stud Attachments for Implant Overdenture (임플란트 피개의치를 위한 개별유지형 어태치먼트의 유지력에 관한 연구)

  • Song, Eun-Ju;Bae, Eun-Bin;Choi, Jae-Won;Bae, Ji-Hyeon;Kim, Ji-Young;Lee, So-Hyoun
    • Journal of dental hygiene science
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    • v.16 no.1
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    • pp.93-100
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    • 2016
  • The purpose of this study was to compare the changes of retentive force in different stud attachment systems for implant retained overdenture. Two commercially available attachments with different retentive forces were investigated: Kerator (pink, blue, red) and O-ring (orange, red). Two implant fixtures were vertically embedded in base mountings. Five pairs of each attachment were evaluated. A universal testing machine was used to evaluate the retentive force of two attachments during wear simulation. Surface characteristics of each attachment system were evaluated with scanning electron microscopy. Five pairs of each attachment were evaluated. Kerator pink showed the highest initial retention. After 2,500 cycles of wear-simulation, Kerator pink noted the largest decrease in retention. According to results of surface analysis, Worn surfaces were obtained in matrices and patrices. Heavy wears were observed in matrices. After 2 year-wear simulation, most attachments exhibited retention loss. Attachments using different kind of material exhibited dissimilar surface alterations.

A Study on the Automatic Generation of Test Case Based on Source Code for Quality Improvement (소프트웨어 품질향상을 위한 소스코드 기반의 테스트 케이스 자동 생성에 관한 연구)

  • Son, Ung-Jin;Lee, Seung-Ho
    • Journal of IKEEE
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    • v.19 no.2
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    • pp.186-192
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    • 2015
  • This paper proposes an automatic generation technology of test case based on API in source code for software's quality improvement. The proposed technology is comprised of four processes which are analyzing source code by using the Doxygen open source tool, defining API specification by using analyzed results, creating test design, generating a test case by adapting Pairwise test technology. Analyzing source code by using the Doxygen open source tool is the phase in which API information in source code such as the API name, input parameter and return parameter are extracted. Defined API specification by using analyzed results is the phase where API informations, which is needed to generate test case, are defined as a form of database by SQLite database on the basis of extracted API information. Creating test design is the phase in which the scenario is designed in order to be composed as database by defining threshold of input and return parameters and setting limitations based on the defined API. Generating a test case by adapting Pairwise test technique is the phase where real test cases are created and changed into database by adapting Pairwise technique on the base of test design information. To evaluate the efficiency of proposed technology, the research was conducted by begin compared to specification based test case creation. The result shows wider test coverage which means the more cases were created in the similar duration of time. The reduction of manpower and time for developing products is expected by changing the process of quality improving in software developing from man-powered handwork system into automatic test case generation based on API of source code.

Expression of Intercellular Adhesion Molecule-1 in Human Idiopathic Pulmonary Fibrosis (인체 특발성 폐섬유증에서 Intercellular Adhesion Molecule-1의 발현에 관한 연구)

  • Park, Sung-Soo;Shin, Dong-Ho;Kim, Tae-Wha;Lee, Dong-Hoo;Lee, Jung-Hee;Lee, Jung-Dal
    • Tuberculosis and Respiratory Diseases
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    • v.40 no.2
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    • pp.185-191
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    • 1993
  • Background: Intercellular adhesion molecule-1(ICAM-1) is a 90 kD surface glycoprotein, associated with ${\alpha}_L{\beta}_2$ and ${\alpha}_M{\beta}_2$ subunit of integrins, that serve as cell-cell and cell-substratum adhesion molecules and help regulate cellular morphology, differentiation, and proliferation. The adhesion molecules likely play important roles in maintaining the normal structure and function of the lung. ICAM-1 system among many cell adhesion molecules is importantly issuing in the pathogenesis of idiopathic pulmonary fibrosis. Methods : By using $IgG_1$ monoclonal antibody for ICAM-1, we investigated immunohistochemically the expression of ICAM-1 in the formalin-fixed, paraffin-embedded tissue sections of the 3 normal cases and 6 pieces of tissues taken 3 cases with idiopathic pulmonary fibrosis. Results : In the 3 normal cases, the expressions of ICAM-1 were not discernible. Up-regulation of the ICAM-1 expression was showed in the interstitial fibroblast cells of alveolar septa in 5 pieces and proliferated alveolar pneumocytes in 1 piece among 6 pieces of tissues taken 3 cases with idiopathic pulmonary fibrosis. Conclusion : It was concluded from these findings that up-regulation of the ICAM-1 expression may be related to pathogenesis of idiopathic pulmonary fibrosis.

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A SHEAR BOND STRENGTH OF RESIN CEMENT BONDED TO HUMAN UNCUT ENAMEL, CUT ENAMEL, AND DENTIN IN VITRO

  • Lee Jong-Yeop
    • The Journal of Korean Academy of Prosthodontics
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    • v.41 no.3
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    • pp.319-324
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    • 2003
  • Statement of problem. Adhesives in dentistry playa major role in the success of restorative treatments. In the treatment of all ceramic restoration it is needed to find the adequate bond strength between enamel and dentin. Purpose. The purpose of this study was to evaluate shear bond strength of resin cement bonded to extracted human uncut enamel, cut enamel, and dentin in vitro. Material and methods. Ten freshly extracted anterior teeth without any previous restorative treatments were chosen. The extracted teeth were embedded in PMMA cold acrylic in the shape of a cylinder, 25 mm in diameter by 25 mm in height. The bonding system used was as follow: Uni-Etch (32% phosphoric acid), One-Step adhesive, Duolink resin cement. The specimens were acid etched and rinsed with water. Two layers of One-Step adhesive were coated with a disposable brush on the uncut enamel. VIP curing light at $500mV/cm^2$ was used to cure the adhesive. For cut enamel shear bond test, the specimen used for uncut enamel was further reduced approximately $0.3{\sim}0.5mm$ using a laminate preparation diamond bur (0.3 mm in depth). The specimens were subsequently treated with 320-grit SiC paper followed by 600-grit SiC paper and cleaned with distilled water. The bonding procedure on the cut enamel was same as uncut enamel bonding procedure. For dentin bonding test, the specimen used for cut enamel was further reduced approximately $0.5mm{\sim}1.0mm$ using a laminate preparation diamond bur (0.5 mm in depth of diamond cutting). The amount of reduction was evaluated with the silicone mold. The specimens were subsequently treated with 320-grit SiC paper followed by 600-grit silicon carbon paper and cleaned in distilled water. The bonding procedure on the dentin was same as uncut enamel bonding procedure. All samples were mounted and secured on the Ultradent shear bond test sample holder, and Ultradent restricted shear bond testing device was used with Universal Instron machine until fracture. Analysis of variance (ANOVA) test was performed comparing the result at P<0.05. Multiple comparison (Tukey) was used to compare each groups. Result. The result showed that the mean value in shear bond strength of resin cement bonded to uncut enamel, cut enamel and dentin were 27.04 Mpa, 30.25 Mpa and 26.39 Mpa with respect. Conclusion. Within the limitation of this study, the mean value of the shear bond strength of cut enamel was higher than those of uncut enamel or dentin. However there existed no statistical differences between three different human dentition substrates due to increased adhesive characteristics.

Scalable Fingerprinting Scheme based on Angular Decoding for LCCA Resilience (선형결합 공모공격에 강인한 각도해석 기반의 대용량 핑거프린팅)

  • Seol, Jae-Min;Kim, Seong-Whan
    • The KIPS Transactions:PartD
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    • v.15D no.5
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    • pp.713-720
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    • 2008
  • Fingerprinting scheme uses digital watermarks to trace originator of unauthorized or pirated copies, however, multiple users may collude and escape identification by creating an average or median of their individually watermarked copies. Previous research works are based on ACC (anti-collusion code) for identifying each user, however, ACC are shown to be resilient to average and median attacks, but not to LCCA and cannot support large number of users. In this paper, we propose a practical SACC (scalable anti-collusion code) scheme and its angular decoding strategy to support a large number of users from basic ACC (anti-collusion code) with LCCA (linear combination collusion attack) robustness. To make a scalable ACC, we designed a scalable extension of ACC codebook using a Gaussian distributed random variable, and embedded the resulting fingerprint using human visual system based watermarking scheme. We experimented with standard test images for colluder identification performance, and our scheme shows good performance over average and median attacks. Our angular decoding strategy shows performance gain over previous decoding scheme on LCCA colluder set identification among large population.

Direct Pass-Through based GPU Virtualization for Biologic Applications (바이오 응용을 위한 직접 통로 기반의 GPU 가상화)

  • Choi, Dong Hoon;Jo, Heeseung;Lee, Myungho
    • KIPS Transactions on Software and Data Engineering
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    • v.2 no.2
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    • pp.113-118
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    • 2013
  • The current GPU virtualization techniques incur large overheads when executing application programs mainly due to the fine-grain time-sharing scheduling of the GPU among multiple Virtual Machines (VMs). Besides, the current techniques lack of portability, because they include the APIs for the GPU computations in the VM monitor. In this paper, we propose a low overhead and high performance GPU virtualization approach on a heterogeneous HPC system based on the open-source Xen. Our proposed techniques are tailored to the bio applications. In our virtualization framework, we allow a VM to solely occupy a GPU once the VM is assigned a GPU instead of relying on the time-sharing the GPU. This improves the performance of the applications and the utilization of the GPUs. Our techniques also allow a direct pass-through to the GPU by using the IOMMU virtualization features embedded in the hardware for the high portability. Experimental studies using microbiology genome analysis applications show that our proposed techniques based on the direct pass-through significantly reduce the overheads compared with the previous Domain0 based approaches. Furthermore, our approach closely matches the performance for the applications to the bare machine or rather improves the performance.

Using a H/W ADL-based Compiler for Fixed-point Audio Codec Optimization thru Application Specific Instructions (응용프로그램에 특화된 명령어를 통한 고정 소수점 오디오 코덱 최적화를 위한 ADL 기반 컴파일러 사용)

  • Ahn Min-Wook;Paek Yun-Heung;Cho Jeong-Hun
    • The KIPS Transactions:PartA
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    • v.13A no.4 s.101
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    • pp.275-288
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    • 2006
  • Rapid design space exploration is crucial to customizing embedded system design for exploiting the application behavior. As the time-to-market becomes a key concern of the design, the approach based on an application specific instruction-set processor (ASIP) is considered more seriously as one alternative design methodology. In this approach, the instruction set architecture (ISA) for a target processor is frequently modified to best fit the application with regard to code size and speed. Two goals of this paper is to introduce our new retargetable compiler and how it has been used in ASIP-based design space exploration for a popular digital signal processing (DSP) application. Newly developed retargetable compiler provides not only the functionality of previous retargetable compilers but also visualizes the features of the application program and profiles it so that it can help architecture designers and application programmers to insert new application specific instructions into target architecture for performance increase. Given an initial RISC-style ISA for the target processor, we characterized the application code and incrementally updated the ISA with more application specific instructions to give the compiler a better chance to optimize assembly code for the application. We get 32% performance increase and 20% program size reduction using 6 audio codec specific instructions from retargetable compiler. Our experimental results manifest a glimpse of evidence that a higgly retargetable compiler is essential to rapidly prototype a new ASIP for a specific application.