• Title/Summary/Keyword: Point kernel

Search Result 196, Processing Time 0.023 seconds

An Analytical Model for Predicting Heat Transport due to a Point Source in Coastal Water under a Spring-Neap Modulation of Tidal Currents (조류의 대.소조 변동이 존재하는 연안역에서의 점열원에 의한 열오염의 이동 예측을 위한 해석해 모형)

  • 이호진;김종학
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.16 no.2
    • /
    • pp.92-102
    • /
    • 2004
  • In this paper, an analytical solution of calculating the excess temperature field due to a point heat source is presented in the presence of spring-neap modulation of convective alongshore flow. The basic form of the solution is identical to that given by Jung et al. (2003) but the convective term in the exponential kernel function is extended and a spring-neap variation in the horizontal eddy diffusivity is newly introduced. A set of calculations have been performed to examine the sensitivity of the heat build-up to the change in current fields and turbulent dispersion. Results indicate that the excess temperature field is confined within the tidal excursion distance, while the excess temperature field beyond the distance is mainly controlled by the horizontal diffusion. The heat build-up within the distance is considerably affected by the spring-neap variation in the horizontal eddy diffusivity; the relatively high excess temperature more than 1$^{\circ}C$ is extended further when the eddy diffusivity has spring-neap modulation.

An Optimization Method for Hologram Generation on Multiple GPU-based Parallel Processing (다중 GPU기반 홀로그램 생성을 위한 병렬처리 성능 최적화 기법)

  • Kook, Joongjin
    • Smart Media Journal
    • /
    • v.8 no.2
    • /
    • pp.9-15
    • /
    • 2019
  • Since the computational complexity for hologram generation increases exponentially with respect to the size of the point cloud, parallel processing using CUDA and/or OpenCL library based on multiple GPUs has recently become popular. The CUDA kernel for parallelization needs to consist of threads, blocks, and grids properly in accordance with the number of cores and the memory size in the GPU. In addition, in case of multiple GPU environments, the distribution in grid-by-grid, in block-by-block, or in thread-by-thread is needed according to the number of GPUs. In order to evaluate the performance of CGH generation, we compared the computational speed in CPU, in single GPU, and in multi-GPU environments by gradually increasing the number of points in a point cloud from 10 to 1,000,000. We also present a memory structure design and a calculation method required in the CUDA-based parallel processing to accelerate the CGH (Computer Generated Hologram) generation operation in multiple GPU environments.

The Optimum Operating Conditions of Indented-Cylinder Length Grader to Remove Broken Rice based on Varietal Characteristics (벼 품종별 입형분리기 최적 가동조건)

  • Lee, Choon-Ki;Song, Jin;Yun, Jong-Tag;Seo, Jong-Ho;Lee, Jae-Eun;Kim, Jung-Tae;Jeong, Gun-Ho;Kim, Chung-Kon
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.54 no.4
    • /
    • pp.366-374
    • /
    • 2009
  • To determine the optimum operating conditions of the indented cylinder length grader based on varietal characteristics, broken rice removal capabilities were measured on the milled rice of 41 varieties at different conditions consisted of 3 types of indented cylinders with different indent-opening diameters and 3 different collecting-angles of broken rice. The broken rice removal capabilities were swayed by the indent's opening diameter and depth as well as the angle of the collecting trough of broken rice on the point of instrument, and by the kernel length and width as well as 1000 grain weight of milled rice on the point of rice variety. When the angle of broken rice collecting-trough reached to near the horizontal center line of the indented cylinder on the direction of upward turning side, which was referred $0^{\circ}$ in this paper, the amount of rice collected in trough increased, whereas the loss of head rice also increased. Considering the removal rate of broken rice as well as loss of head rice, it was thought that the suitable angle of trough for broken rice collecting was located $5^{\circ}$ to $15^{\circ}$ depending on varietal characteristic and indent opening diameter. It was thought that 4.2 mm or more of indent opening diameter was recommendable for the rice varieties having heavier 1000 grain weight than 22.3g, as well as larger sizes than 2.9 and 5.2 mm in width and length of rice kernel, respectively; 3.8 mm for the small-sized thin kernels, and a proper diameter between 3.8 and 4.2 mm for short to middle kernels. The varieties with relatively shorter length compared to width of kernel were more difficult to separate the broken rice than the opposite ones. For effective separation of that, it seems that some specific indent shapes such as wider opening and shallow depth etc. are required. When the broken rice content were excessively high, wider diameters of indent openings than specified sizes were thought to be the better.

Characterization of quality changes of whole super sweet corn (Zea mays saccharata Sturt.) during thermal sterilization for shelf-stable products (상온유통을 위한 가열살균 중의 통 초당옥수수의 품질변화 연구)

  • Lee, Yun Ju;Yoon, Won Byong
    • Journal of Applied Biological Chemistry
    • /
    • v.62 no.1
    • /
    • pp.25-30
    • /
    • 2019
  • This study investigated the quality changes in whole super sweet corn during thermal processing to extend its shelf-life. To minimize the reduction of unique texture of whole sweet corn after the sterilization, the alcohol sanitation applied and the cold point of a whole corn ear was determined using a computer simulation. The cold point was located between the corn kernel and the cob. The microorganisms on the surface of sweet corn were reduced by more than 1 log CFU/g after alcohol sanitation, then the whole corn was treated to satisfy the degree of sterilization ($F_{121.1}=4$). The quality of sterilized sweet corn was compared with the control that was treated with steaming. The quality changes of sterilized sweet corn during storage were monitored for 9 months at $25^{\circ}C$. The hardness was maintained within 30% of its initial value. The minimum of hardness was $464.50{\pm}103.35g$ and maximum of hardness was $514.50{\pm}81.83g$. The differences in the sugar content among the samples were found, but the sugar content of corn kernel remained within 30% of the control, ranging from $28.83{\pm}1.05$ to $34.36{\pm}0.42%$. The yellowness was higher than that of control by 5%. The maximum value of yellowness was $34.36{\pm}0.42$. The general bacteria and molds and yeasts in corn kernel stored at $25^{\circ}C$ were not detected after 9 months of storage at $25^{\circ}C$. Therefore, in this study, we have demonstrated that the thermal sterilized method extends the shelf-life of whole sweet corn with minimizing its quality changes over 6 months in room temperature.

Wi-Fi Line-of-Sight Signal based Indoor Localization Method Using Smartphone and Two Dual-band APs (2개의 이중대역 AP와 스마트폰을 이용한 Wi-Fi LOS 신호 기반의 실내 측위 기법)

  • Jo, Hyeonjeong;An, Hyunseong;Kim, Seungku
    • Journal of Korea Multimedia Society
    • /
    • v.21 no.5
    • /
    • pp.583-591
    • /
    • 2018
  • With the development of ICT(Information and Communication Technology), the number of smart devices is rapidly increasing. LBS(Location Based Service) applications that provide user's location based service are used in various fields. There is also a growing demand for indoor precision positioning technology to provide seamless services. In this paper, we propose an indoor positioning system that estimates the location of a smartphone user. The proposed algorithm determines whether the received signal is LOS(Line-of-Sight) or NLOS(Non-Line of-Sight) in order to decrease multipath effect by the indoor environment. The proposed positioning algorithm is very simple and requires only the AP(Access Point) coordinates. In addition, it requires only two APs for estimating the location of a smartphone user. The proposed algorithm is a practically applicable technology without any additional hardware and kernel modification in the smartphone. In the experiment results, the reliability of the positioning system was found to be within 0.83 m.

Asian Image-mathematics System from the Viewpoint of Three Category (삼원적 구조로 본 상수역학 체계;사상(四象)${\cdot}$오행(五行)${\cdot}$육기(六氣)를 중심으로)

  • Kim, Byoung-Soo
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.21 no.5
    • /
    • pp.1065-1071
    • /
    • 2007
  • It has been known that Asian Medicine theory are based on yin and yang & Five Phases. but recently many therapist using asian medicine in Korea or another nations, take up the position that it is not inevitable for them to adopt the theory of yin-and-yang & Five Phases when they cure a patient. but the point of this view suggests they can not understand totally the real theory about yin-and-yang & Five Phases. asian image-mathematics based on I-Ching could analysis all things with the natural number. the kernel of understanding on principle of I-Ching is realizing that the standard should be changed in some conditions and the form of cosmos should change endless. the system of all thing under sun is divided in three parts on the asian image-mathematics. the nature number from one to nine is divided in three categories that are grouped as 123, 456, 789. So, if we want to understand Five Phases theory, we suggest that it is useful to know the organic connected relations among Four Images, Five Phases, Six Qi(six kinds of weather). the aim of this paper is to arrive at understanding of profound learning on image-mathematics throughout the number of 4, 5, 6 in the concrete context.

A Fast Booting Scheme of Linux for Embedded System (임베디드 시스템을 위한 리눅스의 빠른 부팅 기법)

  • Park, Seong-Ho;Shine, Kwang-Mu;Kim, Young-Ju
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.10 no.12
    • /
    • pp.2173-2180
    • /
    • 2006
  • Linux has peculiarities of safety, flexibility, and open source. and Linux supports various hardware platforms. But because general Linux was designed for high performance H/W, Linux has several points to support for embedded system with limited resource. Specially, a main point is booting time that is spent to tens of second. In this paper, we purpose a fast booting scheme of Linux for Embedded System and estimate a performance of scheme purposed through realized prototype. Specially, to reduce booting time in environment of embedded system, we optimize boot loader, kernel and root file system. As a result, boot time reduce 28 second to 11 second in HBE-EMPOS II.

Detection of Multiple Salient Objects by Categorizing Regional Features

  • Oh, Kang-Han;Kim, Soo-Hyung;Kim, Young-Chul;Lee, Yu-Ra
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.10 no.1
    • /
    • pp.272-287
    • /
    • 2016
  • Recently, various and effective contrast based salient object detection models to focus on a single target have been proposed. However, there is a lack of research on detection of multiple objects, and also it is a more challenging task than single target process. In the multiple target problem, we are confronted by new difficulties caused by distinct difference between properties of objects. The characteristic of existing models depending on the global maximum distribution of data point would become a drawback for detection of multiple objects. In this paper, by analyzing limitations of the existing methods, we have devised three main processes to detect multiple salient objects. In the first stage, regional features are extracted from over-segmented regions. In the second stage, the regional features are categorized into homogeneous cluster using the mean-shift algorithm with the kernel function having various sizes. In the final stage, we compute saliency scores of the categorized regions using only spatial features without the contrast features, and then all scores are integrated for the final salient regions. In the experimental results, the scheme achieved superior detection accuracy for the SED2 and MSRA-ASD benchmarks with both a higher precision and better recall than state-of-the-art approaches. Especially, given multiple objects having different properties, our model significantly outperforms all existing models.

On Security of Android Smartphone Apps Employing Cryptography (안드로이드 스마트폰 암호 사용 앱 보안 분석 및 대응)

  • Park, Sang-Ho;Kim, Hyeonjin;Kwon, Taekyoung
    • Journal of the Korea Institute of Information Security & Cryptology
    • /
    • v.23 no.6
    • /
    • pp.1049-1055
    • /
    • 2013
  • Smartphones are rapidly growing because of easy installation of the apps (application software) that users actually want. There are increasingly many apps that require cryptographic suites to be installed, for instance, for protecting account and financial data. Android platform provides protection mechanisms for memory and storage based on Linux kernel, but they are vulnerable to rooting attacks. In this paper, we analyze security mechanisms of Android platform and point out security problems. We show the security vulnerabilities of several commercial apps and suggest appropriate countermeasures.

Power Comparison between Methods of Empirical Process and a Kernel Density Estimator for the Test of Distribution Change (분포변화 검정에서 경험확률과정과 커널밀도함수추정량의 검정력 비교)

  • Na, Seong-Ryong;Park, Hyeon-Ah
    • Communications for Statistical Applications and Methods
    • /
    • v.18 no.2
    • /
    • pp.245-255
    • /
    • 2011
  • There are two nonparametric methods that use empirical distribution functions and probability density estimators for the test of the distribution change of data. In this paper we investigate the two methods precisely and summarize the results of previous research. We assume several probability models to make a simulation study of the change point analysis and to examine the finite sample behavior of the two methods. Empirical powers are compared to verify which is better for each model.