• 제목/요약/키워드: 3D sampling

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Sampling Methods for the 'dark grey cutworm' (Agrotis tokionis B.) Larval Population and Effect of its Larval Density on Tobacco Yield (숯검은밤나방(Agrotis tokionis B.) 유충개체군의 밀도추정방법 및 유충밀도와 연초감수량의 관계)

  • Kim S.S.;Boo K.S.;Kang Y.K.
    • Korean journal of applied entomology
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    • 제20권4호
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    • pp.217-222
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    • 1981
  • As a primary study on the economic injury level of A. tokionis larval populations in tobacco fields, we carried out some experiments for the evaluation of sampling efficiency of 3 sampling methods (pit-fall traps of apple pomace and rice bran, and clover patches) for the larval population and the regressions between loss and infested larval density The $10\times10cm$ clover patch showed a better sampling efficiency $11.8\;to\;18.0\%$ than the others. The sampling efficiency of clover patch becomes higher when the plots did not have any green plants. The linear regression equation (Y=4.2+1.383x) between loss (Y:kg/10a) and infested larval density (X: no. of larvae/plot) which was obtained by substitution of damage ratio and corrected damage ratio fitted the observed data better than the one (Y=2.68X) obtained without substitioning.

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Improved Sampling Method For Volume Rendering (Volume Rendering를 위한 향상된 Sampling 방법)

  • 박재영;이병일;최흥국
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 한국신호처리시스템학회 2000년도 하계종합학술대회논문집
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    • pp.213-216
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    • 2000
  • 본 논문에서는 volume rendering 기법을 이용하여 2차원 MRI 영상들을 합성하여 3차원 영상 만들 때 보다 해상도를 높이기 위한 개선된 sampling방법을 소개한다 2차원 슬라이스 영상들이 3차원으로 재구성할 때 voxel 기반으로 렌더링을 하기 때문에 오브젝트의 내부 영역까지도 볼 수 있는 것이 volume rendering의 가장 큰 장점이다. 따라서 영상을 재구성하는 과정에서 보다 향상된 interpolation을 적용시켜서 공간 해상도를 향상시키면 보다 명확하게 오브젝트 내부 정보를 살펴 볼 수 있다. 본 논문에서는 nearest neighbor 이나 linear 같은 interpolation으로 sampling한 방법보다 cubic interpolation을 3차원 공간에서 적용 시켜서 보다 resampling이 잘 되도록 하여 해상도를 향상시켜 보았다. 이렇게 향상된 Interpolation 적용시켜서 렌더링할 때 얼마나 오브젝트 내부 영역이 잘 가시화가 되었는지 transfer function을 적용시켜서 오브젝트 내부 정보를 렌더링 해보았고, 임의의 축으로 오브젝트을 잘라서 2D 단면 영상으로 출력해 보았다. 보다 향상된 interpolation을 적용시켜서 resampling을 하면 영상 해상도가 개선되었음을 볼 수 있었다.

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A Design and Implementation of Volume Rendering Program based on 3D Sampling (3차원 샘플링에 기만을 둔 볼륨랜더링 프로그램의 설계 및 구현)

  • 박재영;이병일;최흥국
    • Journal of Korea Multimedia Society
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    • 제5권5호
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    • pp.494-504
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    • 2002
  • Volume rendering is a method of displaying volumetric data as a sequence two-dimensional image. Because this algorithm has an advantage of visualizing structures within objects, it has recently been used to analyze medical images i.e, MRI, PET, and SPECT. In this paper. we suggested a method for creating images easily from sampled volumetric data and applied the interpolation method to medical images. Additionally, we implemented and applied two kinds of interpolation methods to improve the image quality, linear interpolation and cubic interpolation at the sampling stage. Subsequently, we compared the results of volume rendered data using a transfer function. We anticipate a significant contribution to diagnosis through image reconstruction using a volumetric data set, because volume rendering techniques of medical images are the result of 3-dimensional data.

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A CMOS IR-UWB RFIC for Location Based Systems (위치 기반 시스템을 위한 CMOS IR-UWB RFIC)

  • Lee, Jung Moo;Park, Myung Chul;Eo, Yun Seong
    • Journal of the Institute of Electronics and Information Engineers
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    • 제52권12호
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    • pp.67-73
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    • 2015
  • This paper presents a fully integrated 3 - 5 GHz IR-UWB(impulse radio ultra-wide band) RFIC for Location based system. The receiver architecture adopts the energy detection method and for high speed sampling, the equivalent time sampling technique using the integrated DLL(delay locked loop) and 4 bit ADC. The digitally synthesized UWB impulse generator with low power consumption is also designed. The designed IR-UWB RFIC is implemented on $0.18{\mu}m$ CMOS technology. The receiver's sensitivity is -85.7 dBm and the current consumption of receiver and transmitter is 32 mA and 25.5 mA respectively at 1.8 V supply.

A study on the implementation simulation and system for 2-D doppler system using second-order sampling (2차 샘플링을 이용한 2-D 도플러 시스템의 시뮬레이션과 시스템구현에 관한 연구)

  • 임춘성;임용곤
    • Journal of Biomedical Engineering Research
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    • 제11권1호
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    • pp.147-156
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    • 1990
  • A two-dimensional pulsed doppler system for ultrasonic blood velocity doppler signals is studied and implemented. The second-order sampling method and serial data processing procedures are utillized in the sys- tem, which eliminates the untuning problems at phase channels in the quadrature detection method as well as in the channels of parallel data processing. rho digital signal processor used in this system allows a hardware savings and flexible design options. The efficiency of the various mean frequency estimators in the second-order sampling system is examined by computer simulation as a function of the intersequence sample delay time. The temporal delay for the quadrature component is changed from $1/(4f_o){\;}to{\;}3/(4f_o){\;}and{\;}5/(4f_o)$ where to is the center frequency of the transducer, It is found that autocorrelator is the optimum frequency estimator for the second-order sampling: with !he intersequence sample delay of $1/(4f_o){\;}to{\;}3/(4f_o){\;}and{\;}5/(4f_o)$. The qualitative variation and information proportional to blood velocity in the vessel system are obtained in the VIVO experiments.

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Efficient 3D Object Simplification Algorithm Using 2D Planar Sampling and Wavelet Transform (2D 평면 표본화와 웨이브릿 변환을 이용한 효율적인 3차원 객체 간소화 알고리즘)

  • 장명호;이행석;한규필;박양우
    • Journal of KIISE:Computer Systems and Theory
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    • 제31권5_6호
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    • pp.297-304
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    • 2004
  • In this paper, a mesh simplification algorithm based on wavelet transform and 2D planar sampling is proposed for efficient handling of 3D objects in computer applications. Since 3D vertices are directly transformed with wavelets in conventional mesh compression and simplification algorithms, it is difficult to solve tiling optimization problems which reconnect vertices into faces in the synthesis stage highly demanding vertex connectivities. However, a 3D mesh is sampled onto 2D planes and 2D polygons on the planes are independently simplified in the proposed algorithm. Accordingly, the transform of 2D polygons is very tractable and their connection information Is replaced with a sequence of vertices. The vertex sequence of the 2D polygons on each plane is analyzed with wavelets and the transformed data are simplified by removing small wavelet coefficients which are not dominant in the subjective quality of its shape. Therefore, the proposed algorithm is able to change the mesh level-of-detail simply by controlling the distance of 2D sampling planes and the selective removal of wavelet coefficients. Experimental results show that the proposed algorithm is a simple and efficient simplification technique with less external distortion.

Effect of the Internal Shape of eDNA Filter Case made by the PBF method Metal 3D Printer on Water Sampling Performance (PBF 방식 금속 3D프린터로 제작된 환경DNA 필터 케이스의 내부 형상이 포집 성능에 미치는 영향)

  • Lee, Seung-Min;Park, Se-Hyun;Kwak, Ihn-Sil;Kim, Hyoung-Ho;Kwak, Tae-Soo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • 제20권8호
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    • pp.74-79
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    • 2021
  • This study focuses on designing a filter case using a water pump for application in eDNA filtering systems. Filter cases, channel type and net type were designed based on the flow field and made using a 3D printer for metal. Flow analysis was conducted for each filter case, and the results were consistent with the pressure experiment results. Furthermore, the water sampling performance test showed that the channel-type filter case exhibited a high flow rate and low pressure through the filter. The eDNA extraction experiment showed that the channel type exhibited improved capture ability compared to the net type.

A sampling and estimation method for monitoring poultry red mite (Dermanyssus gallinae) infestation on caged-layer poultry farms

  • Oh, Sang-Ik;Park, Ki-Tae;Jung, Younghun;Do, Yoon Jung;Choe, Changyong;Cho, Ara;Kim, Suhee;Yoo, Jae Gyu
    • Journal of Veterinary Science
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    • 제21권3호
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    • pp.41.1-41.12
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    • 2020
  • Background: The poultry red mite, Dermanyssus gallinae, is a serious problem in the laying hen industry worldwide. Currently, the foremost control method for D. gallinae is the implementation of integrated pest management, the effective application of which necessitates a precise monitoring method. Objectives: The aim of the study was to propose an accurate monitoring method with a reliable protocol for caged-layer poultry farms, and to suggest an objective classification for assessing D. gallinae infestation on caged-layer poultry farms according to the number of mites collected using the developed monitoring method. Methods: We compared the numbers of mites collected from corrugated cardboard traps, regarding with length of sampling periods, sampling sites on cage, and sampling positions in farm buildings. The study also compared the mean numbers of mites collected by the developed method with the infestation levels using by the conventional monitoring methods in 37 caged-layer farm buildings. Results: The statistical validation provided the suitable monitoring method that the traps were installed for 2 days on feed boxes at 27 sampling points which included three vertical levels across nine equally divided zones of farms. Using this monitoring method, the D. gallinae infestation level can be assessed objectively on caged-layer poultry farms. Moreover, the method is more sensitive than the conventional method in detecting very small populations of mites. Conclusions: This method can be used to identify the initial stages of D. gallinae infestation in the caged-layer poultry farms, and therefore, will contribute to establishment of effective control strategies for this mite.

High-Order Temporal Moving Average Filter Using Actively-Weighted Charge Sampling (능동-가중치 전하 샘플링을 이용한 고차 시간상 이동평균 필터)

  • Shin, Soo-Hwan;Cho, Yong-Ho;Jo, Sung-Hun;Yoo, Hyung-Joun
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • 제49권2호
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    • pp.47-55
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    • 2012
  • A discrete-time(DT) filter with high-order temporal moving average(TMA) using actively-weighted charge sampling is proposed in this paper. To obtain different weight of sampled charge, the variable transconductance OTA is used prior to charge sampler, and the ratio of charge can be effectively weighted by switching the control transistors in the OTA. As a result, high-order TMA operation can be possible by actively-weighted charge sampling. In addition, the transconductance generated by the OTA is relatively accurate and stable by using the size ratio of the control transistors. The high-order TMA filter has small size, increased voltage gain, and low parasitic effects due to the small amount of switches and sampling capacitors. It is implemented in the TSMC $0.18-{\mu}m$ CMOS process by TMA-$2^2$. The simulated voltage gain is about 16.7 dB, and P1dB and IIP3 are -32.5 dBm and -23.7 dBm, respectively. DC current consumption is about 9.7 mA.

Accelerating the EM Algorithm through Selective Sampling for Naive Bayes Text Classifier (나이브베이즈 문서분류시스템을 위한 선택적샘플링 기반 EM 가속 알고리즘)

  • Chang Jae-Young;Kim Han-Joon
    • The KIPS Transactions:PartD
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    • 제13D권3호
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    • pp.369-376
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    • 2006
  • This paper presents a new method of significantly improving conventional Bayesian statistical text classifier by incorporating accelerated EM(Expectation Maximization) algorithm. EM algorithm experiences a slow convergence and performance degrade in its iterative process, especially when real online-textual documents do not follow EM's assumptions. In this study, we propose a new accelerated EM algorithm with uncertainty-based selective sampling, which is simple yet has a fast convergence speed and allow to estimate a more accurate classification model on Naive Bayesian text classifier. Experiments using the popular Reuters-21578 document collection showed that the proposed algorithm effectively improves classification accuracy.