• Title/Summary/Keyword: Flow Verification

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Experimental Study of Shape and Pressure Characteristics of Solitary Wave generated by Sluice Gate for Various Conditions (Sluice Gate를 이용한 고립파 발생조건에 따른 형상 및 압력 특성에 관한 실험적 연구)

  • Cho, Jae Nam;Kim, Dong Hyun;Lee, Seung Oh
    • Journal of the Korean Society of Safety
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    • v.31 no.2
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    • pp.70-75
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    • 2016
  • Recently, coastal erosion has been widely in progress and the erosion level becomes also serious in the world wide, espeically in East Sea in Korea. Since it would threaten the life, economics and security risk, it is necessary to much comprehend the reason why coastal erosion has occurred according to the geographical characteristics. Meanwhile, analysis about hydrodynamics of the solitary wave such as tunami in swash zone is needed for the best management practice of coastal erosion. Solitary wave is nonlinear wave and can be reproduced in the laboratoy scale by openning suddenly a sluice gate with water head difference, of which methodology was found in the literature, since it could be simply determined by a significant wave height. Thus, in this sutdy the generation of solitary wave was experimentalized using the sluice gate. Experimental conditions were classified by angles of a beach slope, a water level in a beach slope and a difference of water level between in a headtank and a channel bed. Two kinds of dimensionless analyses based from experimental results in this study were presented; the first analysis indicates nondimensionalization between the wave height and the water level in a beach slope in order to investigate characteristics of solitary wave approaching the beach. The second shows the other nondimensionalization between dynamic pressure and static pressure on a beach slope to investigate the relationship between wave breaking and wave pressure. Under the same conditions as laboratory experiments, the numerical results computed with a SWAN model embedded in FLOW 3D were compared in terms of wave height, and pressure on the beach slope, which shows good agreement with each other. Overall results from this study could provide fundamental hydraulic data for the reliabile verification of numerical simulation results about coastal erosion in swash zone caused by solitary waves.

Prediction Models of Residual Chlorine in Sediment Basin to Control Pre-chlorination in Water Treatment Plant (정수장 전염소 공정 제어를 위한 침전지 잔류 염소 농도 예측모델 개발)

  • Lee, Kyung-Hyuk;Kim, Ju-Hwan;Lim, Jae-Lim;Chae, Seon Ha
    • Journal of Korean Society of Water and Wastewater
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    • v.21 no.5
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    • pp.601-607
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    • 2007
  • In order to maintain constant residual chlorine in sedimentation basin, It is necessary to develop real time prediction model of residual chlorine considering water treatment plant data such as water qualities, weather, and plant operation conditions. Based on the operation data acquired from K water treatment plant, prediction models of residual chlorine in sediment basin were accomplished. The input parameters applied in the models were water temperature, turbidity, pH, conductivity, flow rate, alkalinity and pre-chlorination dosage. The multiple regression models were established with linear and non-linear model with 5,448 data set. The corelation coefficient (R) for the linear and non-linear model were 0.39 and 0.374, respectively. It shows low correlation coefficient, that is, these multiple regression models can not represent the residual chlorine with the input parameters which varies independently with time changes related to weather condition. Artificial neural network models are applied with three different conditions. Input parameters are consisted of water quality data observed in water treatment process based on the structure of auto-regressive model type, considering a time lag. The artificial neural network models have better ability to predict residual chlorine at sediment basin than conventional linear and nonlinear multi-regression models. The determination coefficients of each model in verification process were shown as 0.742, 0.754, and 0.869, respectively. Consequently, comparing the results of each model, neural network can simulate the residual chlorine in sedimentation basin better than mathematical regression models in terms of prediction performance. This results are expected to contribute into automation control of water treatment processes.

A Simulation of the Runoff and the NPS Pollutants Discharge using SWMM Model (SWMM 모형을 이용한 도시 유역의 유출 및 NPS 오염물 배출 모의)

  • 신현석;윤용남
    • Water for future
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    • v.26 no.3
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    • pp.125-135
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    • 1993
  • This study was conducted for two purposes. The first was the selection of the proper model for the urban runoff, and NPS(non-point source) loads and the second was the adjustment of the selected model through the calibration and the verification of the observed data on an urban drainage basin. The selected model for this study was the Storm Water Management Model(SWMM) developed and maintained by the US Environmental Protection Agency(EPA). In particular, the Runoff Block for the surface discharge and the Transport Block for the flow routing was used. The study basin is Youngdu basin, which is a typical developed urban drainage basin. The four rainfall events for the runoff and the two for the four NPS pollutants(SS, BOD, COD and TN) were used for the calibration and the estimation of the model parameters. This study performed the calibration with regard to the peak discharge, the time to peak discharge, the volume and the relative error for three items. It was shown that SWMM can successfully be used for the prediction of the runoff and the NPS pollutants discharge. The result of this study can be used as the basis for the analysis of the correlation between the runoff and the NPS pollutants discharges, and the analysis of the mass balance with the monthly and annual NPS loads in an urban drainage basin.

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The method of in-situ ASTR method diagnosing wall U-value in existing deteriorated houses - Analysis of influence of internal surface total heat transfer rate -

  • Kim, Seo-Hoon;Kim, Jong-Hun;Jeong, Hakgeun;Song, Kyoo-dong
    • KIEAE Journal
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    • v.17 no.4
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    • pp.41-48
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    • 2017
  • Purpose : Currently, 25% of the domestic energy consumption structure is used as building energy, and more than 18% of this energy is consumed in the residential. Accordingly, various efforts and policies that can save energy of the building is being performed. The various researchers are conducting research to diagnose the thermal performance of existing buildings. This study is to apply in the field of precision thermal insulation performance diagnostic method for thermal performance analysis of existing detached house in Seoul, Gangreung, Gyeongju, Pohang. And this paper is analyzed quantitatively measure the existing detached house energy performance. Method: Research methodology analyzed the thermal performance over the Heat Flow Meter method by applying the measurement process and method by applying the criteria of ISO 9869-1 & ASTR method. In this study, the surface heat transfer coefficient was calibrated by applying indoor surface heat transfer resistance with reference to ISO 6946 standard. The measurement error rate between the HFM diagnosis method and the ASTR diagnosis method was reduced and the measurement reliability was obtained through measurement method error verification. Result : As a result of the study, the thermal performance vulnerable parts of the building were quantitatively analyzed, and presented for methods which can be improved capable of efficient energy use buildings.

Design and Implementation of Mobile CRM Utilizing Big Data Analysis Techniques (빅데이터 분석 기법을 활용한 모바일 CRM 설계 및 구현)

  • Kim, Young-Il;Yang, Seung-Su;Lee, Sang-Soon;Park, Seok-Cheon
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.6
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    • pp.289-294
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    • 2014
  • In the recent enterprises and are utilizing the CRM using data mining techniques and new marketing plan. However, data mining techniques are necessary expertise, general public access is difficult, it will be subject to constraints of time and space. in this paper, in order to solve this problem, we have proposed a Mobile CRM applying the data mining method. Thus, to analyze the structure of an existing CRM system, and defines the data flow and format. Also, define the process of the system, was designed sales trend analysis algorithm and customer sales recommendation algorithm using data mining techniques. Evaluation of the proposed system, through the test scenario to ensure proper operation, it was carried out the comparison and verification with the existing system. Results of the test, the value of existing programs and data matches to verify the reliability and use queries the proposed statistical tables to reduce the analysis time of data, it was verified rapidity.

Research trends on the Saam's Acupuncture Method in Korea (국내에서 보고된 사암침법에 대한 연구 동향)

  • Han, Chang-Hyun;Shin, Mi-Suk;Park, Sun-Hee;Choi, Sun-Mi
    • Korean Journal of Oriental Medicine
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    • v.12 no.2 s.17
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    • pp.15-30
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    • 2006
  • Background The Saam's Acupuncture Method is one of the most widely adopted techniques used by clinicians and educational institutions in Korea today. It is originated in the 17th century from a Buddhist monk known as 'Saam'. The reports on the bibliography. biological responses and therapeutic effects of Saam's Acupuncture method were done but trends on the Saam's Acupuncture method were insufficient. Objectives This study aims to review the bibliography, biological responses and therapeutic effects of Saam's Acupuncture. In the process, this review will grasp trends in this field of studies and will direct further researches into the right direction. Method We searched and investigated th journals supplied by Korean Oriental Medical Society and Je-Han Oriental Medical Academy homepage etc. with the key world 'Saam(사암), jung-geuk(정격), seung-gyuk(승격), han-geuk(한격), yul-geuk(열격)'. Fifty journals were chosen for the review. Result 1. The proportion of basic researches was 10%. The biological responses of Saam's Acupuncture method reveal on blood pressure, regional cerebral blood flow (rCBF). 2. The proportion of literature researches was 48%. The application of Saam's Acupuncture method was many. 3. The proportion of case reports was 26%. Saam's Acupuncture method is applied in the various disease. 4. The proportion of clinical studies was 16%. Clinical studies were increased after the year 2000. Conclusions To elevated quality of studies, we need well-designed experimental methods, efficient secure of experimental groups, appropriate statistical verification, accumulations of knowledges about data research.

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Computational study of the hemodynamics of the patients after the Fontan procedure (Fontan 시술 이후 환자의 혈류역학적 상태에 대한 수치적 연구)

  • Shim, Eun-Bo;Ko, Hyung-Jong;Kim, Kyung-Hoon;Kamm, Roger D.
    • Proceedings of the KSME Conference
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    • 2000.11b
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    • pp.371-376
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    • 2000
  • In this study, the computational method is presented to simulate the hemodynamics of the patients after the Fontan procedure. The short-term feedback control models are implemented to assess the hemodynamic responses of the patients exposed to the stresses such as gravitational effect or hemorrhage. To construct the base line of the Fontan model, we assume an increase in venous tone, in heart rates, and in systemic resistance that are based on the clinical observations. For the verification of the present method we simulate the LBNP (lower body negative pressure) test for the normal and the Fontan model and we compare these with experimental data. Computational results show that the diastolic ABP(arterial blood pressure) increases but the systolic ABP decreases during LBNP. The increase in heart rate is due to the control system activated by the decreased mean ABP and CVP(central venous pressure). In case of the Fontan model, the increased venous tone is the reason of the diminished CVP change during LBNP. We also simulate 20% hemorrhage stress to the patient after the Fontan procedure and these results are compared with the experimental and the existing computational one. Computational results on the hemodynamics of patients after the Fontan procedure show that the mean ABP and cardiac output decrease. Heart rate and systemic resistance increase to compensate for the decrease in ABP. The sensitivity analysis according to the conduit resistance is also presented to delineate the effects of the local blood flow resistance. The cardiac output decreases according to the increase of the conduit resistance. The 50% increase in the conduit resistance causes about 3% decrease of cardiac output.

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Validation of FDS for the Pool Fires within Two Rooms (이중격실 Pool 화재에 대한 FDS 검증분석)

  • Bae, Young-Bum;Ryu, Su-Hyun;Kim, Yun-Il;Lee, Sang-Kyu;Keum, O-Hyun;Park, Jong-Seok
    • Fire Science and Engineering
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    • v.24 no.5
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    • pp.60-67
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    • 2010
  • Fire model shall be verified and validated to reliably predict the consequences of fires within its limitations. Generally the verification and validation procedures are conducted by comparison with experimental test data. This study aims to evaluate predictive capabilities of FDS in the pool fire with two rooms and the sensitivity between input parameters such as heat release rate and ventilation rate and the output values like temperature, concentration, and heat flux. The predictive capabilities of FDS will be evaluated by comparing FDS simulation results with PRISME experimental data which result from the international fire test project. The sensitivity analysis will be conducted to decide which one of input parameters affects outcomes by comparison of FDS results with ${\pm}$ 10% changes of input parameter. From this study, the FDS predictive capabilities are within 20% error range. Heat release rate as input parameter affects most of outcomes and flow rate only has relation with concentration of oxygen and combustion products.

The Flexible Design Architecture for a Continuous Packet Connectivity Protocol on High Speed Packet Access Platform (고속 패킷 접속 규격 플랫폼 기반 연속적인 패킷 연결 프로토콜의 유연한 구조 설계)

  • Kwon, Hyun-Il;Kim, Kyung-Ho;Lee, Chung-Yong
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.46 no.12
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    • pp.30-35
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    • 2009
  • In this paper, we propose the flexible design architecture for a continuous packet connectivity (CPC) Protocol among additional features of 3GPP HSPA+. In order to meet a practical intellectual property (IP) reuse and the developing time reduction design goals, we utterly take a CPC protocol into account to be realized by reusing digital signal processor (DSP) IP of the proven high speed packet access (HSPA) platform with the minimum hardware modification and addition. Based on the Teak series DSP, the proposed CPC protocol is divided into discontinuous transmit and receive mode, CPC manager, and interface with the proven HSPA platform. According to the regularized verification flow for wireless cellular communication applications, the proposed CPC protocol has been verified in various test scenarios.

P2P Traffic Classification using Advanced Heuristic Rules and Analysis of Decision Tree Algorithms (개선된 휴리스틱 규칙 및 의사 결정 트리 분석을 이용한 P2P 트래픽 분류 기법)

  • Ye, Wujian;Cho, Kyungsan
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.3
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    • pp.45-54
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    • 2014
  • In this paper, an improved two-step P2P traffic classification scheme is proposed to overcome the limitations of the existing methods. The first step is a signature-based classifier at the packet-level. The second step consists of pattern heuristic rules and a statistics-based classifier at the flow-level. With pattern heuristic rules, the accuracy can be improved and the amount of traffic to be classified by statistics-based classifier can be reduced. Based on the analysis of different decision tree algorithms, the statistics-based classifier is implemented with REPTree. In addition, the ensemble algorithm is used to improve the performance of statistics-based classifier Through the verification with the real datasets, it is shown that our hybrid scheme provides higher accuracy and lower overhead compared to other existing schemes.