• Title/Summary/Keyword: Trial And Error Method

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Large Scale SWAT Watershed Modeling Considering Multi-purpose Dams and Multi-function Weirs Operation - For Namhan River Basin - (다목적 댐 및 다기능 보 운영을 고려한 대유역 SWAT 모형 구축기법 연구 - 남한강 유역을 대상으로 -)

  • Ahn, So Ra;Lee, Ji Wan;Jang, Sun Sook;Kim, Seong Joon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.58 no.4
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    • pp.21-35
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    • 2016
  • This study is to evaluate the applicability of SWAT (Soil and Water Assessment Tool) model for multi-purpose dams and multi-function weirs operation in Namhan river basin ($12,577km^2$) of South Korea. The SWAT was calibrated (2005 ~ 2009) and validated (2010 ~ 2014) considering of 4 multi-purpose dams and 3 multi-function weirs using daily observed dam inflow and storage, evapotranspiration, soil moisture, and groundwater level data. Firstly, the dam inflow was calibrated by the five steps; (step 1) the physical rate between total runoff and evapotranspiration was controlled by ESCO, (step 2) the peak runoff was calibrated by CN, OV_N, and CH_N, (step 3) the baseflow was calibrated by GW_DELAY, (step 4) the recession curve of baseflow was calibrated by ALPHA_BF, (step 5) the flux between lateral flow and return flow was controlled by SOL_AWC and SOL_K, and (step 6) the flux between reevaporation and return flow was controlled by REVAPMN and GW_REVAP. Secondly, for the storage water level calibration, the SWAT emergency and principle spillway were applied for water level from design flood level to restricted water level for dam and from maximum to management water level for weir respectively. Finally, the parameters for evapotranspiration (ESCO), soil water (SOL_AWC) and groundwater level fluctuation (GWQMN, ALPHA_BF) were repeatedly adjusted by trial error method. For the dam inflow, the determination coefficient $R^2$ was above 0.80. The average Nash-Sutcliffe efficiency (NSE) was from 0.59 to 0.88 and the RMSE was from 3.3 mm/day to 8.6 mm/day respectively. For the water balance performance, the PBIAS was between 9.4 and 21.4 %. For the dam storage volume, the $R^2$ was above 0.63 and the PBIAS was between 6.3 and 13.5 % respectively. The average $R^2$ for evapotranspiration and soil moisture at CM (Cheongmicheon) site was 0.72 and 0.78, and the average $R^2$ for groundwater level was 0.59 and 0.60 at 2 YP (Yangpyeong) sites.

The Effects of distilled Wild Ginseng Herbal Acupuncture on the Heart Rate Variability(HRV) (산삼 약침이 정상인의 심박변이도(HRV)에 미치는 영향)

  • Roh, Jeong-Du;Kim, Lak-Hyung;Song, Beom-Yong;Yook, Tae-Han
    • Journal of Pharmacopuncture
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    • v.11 no.1
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    • pp.55-69
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    • 2008
  • Objective : We investigated the effects of distilled Wild Ginseng Herbal Acupuncture on autonomic nervous system with the Heart Rate Variability(HRV) in adult man. as well as we tried to observe how distilled Wild Ginseng Herbal Acupuncture on the balance of the autonomic nervous system. Method : We investigated the effects of distilled Wild Ginseng Herbal Acupuncture on autonomic nervous system with the Heart Rate Variability(HRV) in adult man. as well as we tried to observe how distilled Wild Ginseng Herbal Acupuncture on the balance of the autonomic nervous system. 1 healthy volunteers consisted of 31 subjects in experiment(distilled Wild Ginseng Herbal Acupuncture) group and 30 subjects in control(Normal Saline) group. Study form was a randomized, placebo-controlled, double-blind clinical trial. 31 subjects in experiment group were injected distilled Wild Ginseng Herbal Acupuncture at $GB_{21}$(Kyonjong) and 30 subjects in control group were injected Normal Saline at $GB_{21}$(Kyonjong). except of 2 subjects(in control group) who can't be measured and 11 subjects(7 in experiment group and 4 in control group) who move or make unforceable error during measuring. Finally 24 subject in experiment group and 24 subject in control group are studied. We measured HRV by PolyG-I on 7 times : before and after injection per 5 minutes during 30 minutes. The SPSS 10.0 for windows was used to analyze the data and the paired t-test(in group) and Student t-test(between two groups) were used to verify the result. Result : 1. After distilled Wild Ginseng Herbal Acupuncture injection, Mean HRV is significantly low only for first 5 minute, SDNN is significantly high after 5 minute, Complexity is significantly low after 5 minute, HRV index is significantly high after 10 minute and pNN50 is significantly low after 5 minute. 2. SDNN of distilled Wild Ginseng Herbal Acupuncture Group significantly increased from 20minute to 25minute, and pNN50 of distilled Wild Ginseng Herbal Acupuncture Group significantly decreased from 10minute to 15minute and 20 minute to 30 minute compared with those of Normal Saline group. 3. After distilled Wild Ginseng Herbal Acupuncture injection, Ln(TP), Ln(VLF) and Ln(LF) are significantly high after 5 minute, normalized LF is significantly high after 5 minute and normalized HF is significantly low after 5 minute. 4. Ln(TP) and Ln(VLF) of distilled Wild Ginseng Herbal Acupuncture Group significantly increased from 20minute to 25 minute compared with those of Normal Saline group. Conclusion : The results suggest that distilled Wild Ginseng Herbal Acupuncture in healthy adult man tend to activate the autonomic nervous system and sympathetic nervous system compared to Normal Saline within normal range.

Shipboard Fire Evacuation Route Prediction Algorithm Development (선박 화재시 승선자 피난동선예측을 위한 알고리즘 개발 기초연구)

  • Hwang, Kwang-Il;Cho, So-Hyung;Ko, Hoo-Sang;Cho, Ik-Soon;Yun, Gwi-Ho;Kim, Byeol
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.5
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    • pp.519-526
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    • 2018
  • In this study, an algorithm to predict evacuation routes in support of shipboard lifesaving activities is presented. As the first step of algorithm development, the feasibility and necessity of an evacuation route prediction algorithm are shown numerically. The proposed algorithm can be explained in brief as follows. This system continuously obtains and analyzes passenger movement data from the ship's monitoring system during non-disaster conditions. In case of a disaster, evacuation route prediction information is derived using the previously acquired data and a prediction tool, with the results provided to rescuers to minimize casualties. In this study, evacuation-related data obtained through fire evacuation trials was filtered and analyzed using a statistical method. In a simulation using the conventional evacuation prediction tool, it was found that reliable prediction results were obtained only in the SN1 trial because of the conceptual and structural nature of the tool itself. In order to verify the validity of the algorithm proposed in this study, an industrial engineering tool was adapted for evacuation characteristics prediction. When the proposed algorithm was implemented, the predicted values for average evacuation time and route were very similar to the measured values with error ranges of 0.6-6.9 % and 0.6-3.6 %, respectively. In the future, development of a high-performance evacuation route prediction algorithm is planned based on shipboard data monitoring and analysis.

A Comparative Analysis of the Forecasting Performance of Coal and Iron Ore in Gwangyang Port Using Stepwise Regression and Artificial Neural Network Model (단계적 회귀분석과 인공신경망 모형을 이용한 광양항 석탄·철광석 물동량 예측력 비교 분석)

  • Cho, Sang-Ho;Nam, Hyung-Sik;Ryu, Ki-Jin;Ryoo, Dong-Keun
    • Journal of Navigation and Port Research
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    • v.44 no.3
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    • pp.187-194
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    • 2020
  • It is very important to forecast freight volume accurately to establish major port policies and future operation plans. Thus, related studies are being conducted because of this importance. In this paper, stepwise regression analysis and artificial neural network model were analyzed to compare the predictive power of each model on Gwangyang Port, the largest domestic port for coal and iron ore transportation. Data of a total of 121 months J anuary 2009-J anuary 2019 were used. Factors affecting coal and iron ore trade volume were selected and classified into supply-related factors and market/economy-related factors. In the stepwise regression analysis, the tonnage of ships entering the port, coal price, and dollar exchange rate were selected as the final variables in case of the Gwangyang Port coal volume forecasting model. In the iron ore volume forecasting model, the tonnage of ships entering the port and the price of iron ore were selected as the final variables. In the analysis using the artificial neural network model, trial-and-error method that various Hyper-parameters affecting the performance of the model were selected to identify the most optimal model used. The analysis results showed that the artificial neural network model had better predictive performance than the stepwise regression analysis. The model which showed the most excellent performance was the Gwangyang Port Coal Volume Forecasting Artificial Neural Network Model. In comparing forecasted values by various predictive models and actually measured values, the artificial neural network model showed closer values to the actual highest point and the lowest point than the stepwise regression analysis.

Case Study of Service-Learning Linked to 'History of Science' Lecture for Pre-service Science Teachers (예비과학교사의 과학사 강좌 봉사-학습(Service-Learning) 운영 사례 연구)

  • Yoon, Ma-Byong
    • The Journal of the Korea Contents Association
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    • v.19 no.9
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    • pp.567-581
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    • 2019
  • Service-Learning (S-L) is an experiential learning-based teaching-learning method that connects students with curriculum and school-based community service and raises students' academic ability and social responsibility awareness through the value of 'reflection' and 'reciprocity'. This study analyzed the case of S-L course of 'History of Science and Inquire Activity' for pre-service science teachers (PSTs). The S-L lectures linked to the subjects of the History of Science were conducted in terms of three stages (Preparation-Implementation-Evaluation), and S-L classes were conducted in three schools five times. The educational effects of S-L lectures were analyzed by collecting questionnaires, class observation and self-reported reflection diary. The PSTs were able to understand the school realities and improve the teaching abilities and pedagogic content knowledge through educational service activities. The PSTs who participated in the S-L course had hard time due to excessive learning time, the difficulty of preparing the class, the fear of the class, and trial and error. Nonetheless, most of the students responded that they were very satisfied (4.68) with the S-L lecture, and that they could develop self-efficacy for their future teaching career thank to this learning experience.

Dysphagia Rehabilitation Treatment for Children With Feeding Disorder : A Systemic Review (섭식장애가 있는 아동의 연하재활치료 : 체계적 고찰)

  • Jeon, Joo Young;Park, Hae Yean
    • The Journal of Korean Academy of Sensory Integration
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    • v.19 no.1
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    • pp.39-53
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    • 2021
  • Objective : The purpose of this study was to systematically review dysphagia rehabilitation treatment for children with feeding disorders. Methods : The articles evaluated in this study were collected from the PubMed, Medline Complete, and CINAHL databases and subsequently reviewed using the PRISMA flow chart and PICOS approach. A total of 13 papers were analyzed for study quality, disease groups, evaluation tools, interventions, and post-intervention effects. Results : Of the reviewed papers, six (46.15%) related to autism spectrum disorder (ASD) and seven (53.85%) to cerebral palsy (CP) with age ranges of between 2 and 8 years for the ASD studies and between 12 months and 18 years for CP. In evaluating the types of feeding disorder involved, the ASD group exhibited predominantly behavioral conditions while the CP subjects had a larger number of functional oral and swallowing issues. In terms of interventions, behavior modifications were used most frequently with ASD while oral-sensory motor, texture modifications, and electrical stimulation were applied at the same frequency with children with CP. All interventions were found to be effective. Conclusion : In this study, research into children with feeding disorders was reviewed according to condition, evaluation tool, and method of intervention. It is expected that this review can be used as basic data for developing a protocol that will allow clinicians to efficiently apply condition-specific interventions for eating disorders without resorting to trial and error.

Heuristic Appearing in Experimental Manual Processing of Elementary School Students (초등학생의 실험매뉴얼 처리에서 나타나는 휴리스틱)

  • Yang, Ji-Hye;Yang, Il-Ho;Kim, Seong-Un
    • Journal of the Korean Society of Earth Science Education
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    • v.15 no.2
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    • pp.142-157
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    • 2022
  • Heuristic is a empirical method that is used quickly when uncertainty or insufficient time and information are insufficient. The purpose of this study is to find out what heuristics appear in the processing of the experimental manual among science experiment activities of elementary school students. To do this, 20 fifth-grade elementary school students (female 10 and male 10) were required to conduct scientific experimental activities as research participants to collect experimental behavior data and gaze movement data, and retrospective interviews were conducted. The collected data extracted and conceptualized behavior by heuristics. As a result of the study, there were five heuristics that appeared in the processing of the experimental manual: "reducing the difference between the target state and the current state," "guessing the experimental procedure," "paying attention to the expected results," "comparing with the picture of the experimental manual," and "using a trial and error strategy." According to each concept of heuristics, there were favorable and unfavorable aspects for experimental activities. In science experiment activities that students experience for the first time, there is a lack of information and the situation is uncertain, so behavior by heuristics appears in nature. Therefore, educators need to understand students' heuristics and guide scientific experimental activities.

A Study of IT Outsourcing Model for a Public Institution (공공기관의 IT 아웃소싱 모델 연구)

  • Oh, Yeon-Chil;Park, So-Ah;Lee, Young-Seok;Yang, Hae-Kwon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.10
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    • pp.1723-1730
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    • 2008
  • The national IT outsourcing is actively achieved centering around the manufacturing enterprise and financial institution. The If outsourcing of the public institution is generalized. The IT development and operation management task are the field in which first an outsourcing is introduced due to a factor including the technological change, the efper increase in demand, and etc. Particularly, the core business of the public institution is the public service. Therefore, the core business of the public institution can concentrate on the core business and by drastically outsourcing the etc task ran improve an efficiency. Therefore, as to the IT outsourcing, the innovative method that can enhance the quality of the public service can become. In this paper, We analyze how the Supply Administration introducing the service level agreement (SLA: Service Level Agreement) and the problem that the Samsung SDS is faced with were solved. And the practical affairs guide-line for managing elements which can minimize trial and error and successfully implement the IT outsourcing is presented.

Design Methodology on the Steel-type Breakwater I.Design Procedure and Wave Pressure Estimation (철재형 이안제 설계기법 연구 I. 설계 및 파압추정 단계)

  • Kweon, Hyuck-Min;Han, Yu-Shik;Kwon, Oh-Kyun;Ko, Kyoung-Lae
    • Journal of the Korean Society of Hazard Mitigation
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    • v.11 no.3
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    • pp.209-218
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    • 2011
  • The present study proposes a new estimation relationship for the transmission rate of the steel breakwater which is expected to make up for the weakness points in existing hard solution for shore protection. The steel breakwater consists of the wave dissipator of the dual horizontal plates, the supporting columns and their foundations, and thus its respective designs should also be conducted one by one. Furthermore, the breakwater has to ensure both functions of shore protection and structure stabilization. The study produced experimental data for the stability and safety investigation of the steel breakwater. The forces acting on the steel breakwater were classified into two categories, one is vertical up and down loads for the pile resistance and the other was maximum difference of the vertical load acting on horizontally different position for the torsion. The study applied the stability force produced by the summation of maximum pressure at each point and the safety force acting on each point simultaneously. The regular wave corresponding to the significant wave was utilized for measuring wave pressure and force. The study showed the method for the proper position of submerged upper plate by considering occurrence frequency of tide level. The design process finally determined by trial and error is proposed in the present study.

Study on Power Distribution Algorithm in terms of Fuel Equivalent (등가 연료 관점에서의 동력 분배 알고리즘에 대한 연구)

  • Kim, Gyoungeun;Kim, Byeongwoo
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.5 no.6
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    • pp.583-591
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    • 2015
  • In order to evaluate the performance of TAS applied to the hybrid vehicle of the soft belt driven, acceleration performance and fuel consumption performance is to be superior to the existing vehicle. The key components of belt driven TAS(Torque Assist System), such as the engine, the motor and the battery, The key components of the driven belt TAS, such as the engine, the motor, and the battery, have a significant impact on fuel consumption performance of the vehicle. Therefore, in order to improve the efficiency at the point of view based on the overall system, the study of the power distribution algorithm for controlling the main source powers is necessary. In this paper, we propose the power distribution algorithm, applied the homogeneous analysis method in terms of fuel equivalent, for minimizing the fuel consumption. We have confirmed that the proposed algorithm is contribute to improving the fuel consumption performance satisfied the constraints considering the vehicle status information and the required power through the control parameters to minimize the fuel consumption of the engine. The optimization process of the proposed driving strategy can reduce the trial and error in the research and development process and monitor the characteristics of the control parameter quickly and accurately. Therefore, it can be utilized as a way to derive the operational strategy to minimize the fuel consumption.