• Title/Summary/Keyword: Continuous performance test

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The Fatigue Performance Evaluation of Concrete Specimen by Using Mineral Admixture (혼화재 사용에 따른 콘크리트 시험체의 피로성능 평가)

  • Kim, Doo-Hwan;Baek, Kyung-Su
    • Journal of the Korean Society of Safety
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    • v.25 no.5
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    • pp.39-43
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    • 2010
  • The surfacing of bridge-decks are object to secure trafficability and to protect bridge face from impact load of traffic volume and other external conditions. But the deformation of pavements and cracks happen due to the damage of the bridge-decks surfacing from the increase of the traffic, short maintenance period and continuous vibration of bridge. This test is to make the 3-type high performance concrete that has different mixing ratio and is added the blast furnace slag, fly ash and silica respectively, and to compare 3-type high performance concrete of normal high strength concrete of $400kgf/cm^2$ strength through the static loading test and fatigue test. And test specimen is united floor slab and pavement for the durability of bridge.

Design by Topology Optimization and Performance Test of Ultrasonic Bonding Module for Flip-Chip Packaging (초음파 플립칩 접합 모듈의 위상최적화 설계 및 성능 실험)

  • Kim, Ji Soo;Kim, Jong Min;Lee, Soo Il
    • Journal of Welding and Joining
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    • v.30 no.6
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    • pp.113-119
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    • 2012
  • Ultrasonic bonding is the novel packaging method for flip-chip with high yield and low-temperature bonding. The bonding module is a core part of the bonding machine, which can transfer the ultrasonic energy into the bonding spot. In this paper, we propose topology optimization technique which can make new design of boding modules due to the constraints on resonance frequency and mode shapes. The designed bonding module using topology optimization was fabricated in order to evaluate the bonding performance and reliable operation during the continuous bonding process. The actual production models based on the proposed design satisfied the target frequency range and ultrasonic power. The bonding test was performed using flip-chip with lead-free Sn-based bumps, the results confirmed that the bonding strength was sufficient with the designed bonding modules. Also the performance degradation of the bonding module was not observed after the 300-hour continuous process with bonding conditions.

Evolutionary Analysis for Continuous Search Space (연속탐색공간에 대한 진화적 해석)

  • Lee, Joon-Seong;Bae, Byeong-Gyu
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.2
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    • pp.206-211
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    • 2011
  • In this paper, the evolutionary algorithm was specifically formulated for optimization with continuous parameter space. The proposal was motivated by the fact that the genetic algorithms have been most intensively reported for parameter identification problems with continuous search space. The difference of primary characteristics between genetic algorithms and the proposed algorithm, discrete or continuous individual representation has made different areas to which the algorithms should be applied. Results obtained by optimization of some well-known test functions indicate that the proposed algorithm is superior to genetic algorithms in all the performance, computation time and memory usage for continuous search space problems.

Association of the Comprehensive Attention Test and the Korean Wechsler Intelligence Scale for Children-Fourth Edition in Children and Adolescents With Attention-Deficit/Hyperactivity Disorder

  • Min-Su Jang;Sang-Keun Chung;Jong-Chul Yang;Jong-Il Park;Joo-Han Kwon;Tae-Won Park
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.34 no.3
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    • pp.181-187
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    • 2023
  • Objectives: This study aimed to investigate the correlation between the Comprehensive Attention Test, Korean-Wechsler Intelligence Scale for Children-Fourth Edition, and Attention-Deficit/Hyperactivity Disorder (ADHD) Rating Scale-IV scores in children and adolescents with ADHD. Methods: Fifty-five children and adolescents diagnosed with ADHD and not taking psychiatric medications were included in this retrospective study. A correlation analysis was performed. Results: Although simple visual and auditory selective attention have diagnostic value in traditional continuous performance tests, this study revealed that inhibition-sustained attention and interference-selective attention are also effective in evaluating ADHD. Furthermore, the correlation between the attention and intelligence test scores varied depending on the use of visual or auditory stimuli. Conclusion: The findings of this study contribute to clarifying our understanding of the cognitive characteristics of children and adolescents with ADHD and can be used in future research.

A study on Rail Potential Test adaptation for Performance test of DC Railway system (직류 전기철도 성능시험을 위한 레일전위시험 적용연구)

  • Jung, Ho-Sung;Jang, Dong-Uk;Han, Moon-Seob;Park, Hyun-June
    • Proceedings of the KIEE Conference
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    • 2007.10c
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    • pp.238-240
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    • 2007
  • This paper present adaptation method of rail potential test to verify DC railway system's performance and safety. For protection of person and utility caused by rail potential rise, international standard to limit rail potential rise is made and rail potential is tested at the time of plan and construction of DC railway system in foreign country. So, we need rail potential test at the opening time and prepare a continuous monitoring technique of rail potential and a limitation method of rail potential rise. For these, we describe cause of rail potential rise, international standard about rail potential, protection principle, an example of calculation and measurement, and adaptation method for performance test.

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A Preliminary Study for Continuous Performance Test by Subtypes of Attention-Deficit Hyperactivity Disorder (주의력결핍 과잉행동장애 하위 유형별 연속수행과제 양상의 예비 연구)

  • Huh, Seung-Eun;Kim, Young-Hee;Bahn, Geon-Ho;Lee, Won-Hye
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.19 no.2
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    • pp.104-111
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    • 2008
  • Objectives : The purpose of this study was to compare two subtypes of attention-deficit hyperactivity disorder (ADHD) and controls in their attention using ADHD diagnostic system (ADS), a kind of continuous performance test. Methods : Subjects of this study were 8 children with ADHD-predominantly inattentive type, 28 children with ADHD-combined type and 20 control children. Ages ranged from 5 to 14 years. The Korean Educational Development Institute version of the Wechsler Intelligence Scale for Children (KEDI-WISC) and the ADS were administered to all subjects to provide measures of intelligence and attention. Results : Significant differences were found in the ADS variables for the three groups. When compared with controls, the ADHD-predominantly inattentive type children scored significantly higher on the omission error at middle stage and later stage and ADHD-combined type children scored significantly higher on the omission error and reaction time at later stage. When compared with the other two groups, the ADHD-combined type children scored significantly higher on the commission error at all three stages. Conclusion : Our results suggest that the two subtypes of ADHD have different features in attention deficit. And there was a possibility that commission error is available variable to show cognitive characteristics of ADHD-combined type than any other ADS variables. Further studies are needed to evaluate this finding.

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Effects of Neurofeekback Training on EEG, Continuous Performance Task (CPT), and ADHD Symptoms in ADHD-prone College Students

  • Ryoo, ManHee;Son, ChongNak
    • Journal of Korean Academy of Nursing
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    • v.45 no.6
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    • pp.928-938
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    • 2015
  • Purpose: This study explored the effects of neurofeedback training on Electroencephalogram (EEG), Continuous Performance Task (CPT) and ADHD symptoms in ADHD prone college students. Methods: Two hundred forty seven college students completed Korean Version of Conners' Adult ADHD Rating Scales (CAARS-K) and Korean Version of Beck Depression Inventory (K-BDI). The 16 participants who ranked in the top 25% of CAARS-K score and had 16 less of K-BDI score participated in this study. Among them, 8 participants who are fit for the research schedule were assigned to neurofeedback training group and 8 not fit for the research schedule to the control group. All participants completed Adult Attention Deficiency Questionnaire, CPT and EEG measurement at pretest. The neurofeedback group received 15 neurofeedback training sessions (5 weeks, 3 sessions per week). The control group did not receive any treatment. Four weeks after completion of the program, all participants completed CAARS-K, Adult Attention Deficiency Questionnaire, CPT and EEG measurement for post-test. Results: The neurofeedback group showed more significant improvement in EEG, CPT performance and ADHD symptoms than the control group. The improvements were maintained at follow up. Conclusion: Neurofeedback training adjusted abnormal EEG and was effective in improving objective and subjective ADHD symptoms in ADHD prone college students.

Performance Evaluation of Prestressed Concrete Girder Bridges by External Tendon and Continuous Beams (외부긴장재와 연속화에 의한 프리스트레스트 콘크리트 거더교의 성능평가)

  • 박승범;방명석;홍석주
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.681-684
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    • 1999
  • The development of external prestressing methods has been one of the major trends in the concrete bridge constructions over the past decades. One of the promising methods to enhance the flexural strength of a externally prestressed girder is to place the tendons with large eccentricities. The test results in this study showed that the external prestressing of a composite girder increased the range of the elastic behavior, reduced deflections, increased ultimate strength, and added to the redundancy by providing the multiple stress paths. This study was conducted on the concrete bridges reinforced by the continuous girders and the external prestressing.

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FIELD TEST INSTALLATIONS USING N$H_3$SENSOR AND VENTILATION RATE SENSOR FOR CONTINUOUS MEASUREMENT OF TOTAL AMMONIA EMISSION FROM ANIMAL HOUSES

  • Berckmans, D.;Ni, J.Q.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1993.10a
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    • pp.393-402
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    • 1993
  • Two field test installations are discussed. In the first one a new ammonia sensor and an accurate ventilation rate sensor are combined. They are installed in the exhaust chimney in a ventilated pig house. The relative humidity and the room temperature are measured as well. In the second one, an in situ NH$_3$longrightarrowNO converter with subsequent NOx analyser is also being added for accurate ammonia measurement . In this way , the continuous measurement of the total NH$_3$emission can be obtained , the performance of the NH$_3$ sensor can be evaluated, and the ammonia reduction techniques can be tested. The outputs of measurement are fed into a data acquisition system then to a PC in the laboratory. There has been realised the first test installation with which research on the new ammonia sensor is carried out. The primary research results are presented.

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A Study on the Performance Characteristics and Reuse Effect for Recycled Parts of CV Joint and Steering Gear Box in the Vehicles (자동차 중고재생 등속조인트와 스티어링 기어박스의 성능과 활용효과에 대한 연구)

  • 조휘창;박인송
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.5
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    • pp.199-205
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    • 2002
  • The scale of repair parts market reached 0.1 billion won. Above all, it is remarkable that the automotive insurance business world is paying f3r 40 ~5o% of the whole repair cost. The repair parts consist of a genuine parts, non-genuine parts, recycling used parts. It is the recent trend that recycled parts are more popular than the genuine parts f3r repairing crashed cars due to the cost. Performance of recycled continuous velocity(CV) joints and power steering(PS) gear box as replacement parts was tested and analysed in this study. To examine the durability of the recycled parts, the replaced CV joints and PS gear box after repair were tested and analysed periodically. The results were showed that basic performance of the recycled parts was normal. However the ball cage of CV joints was more frequently damaged than genuine parts. We concluded that a test standard and amendment of related laws for recycled parts is required to get a safe and durable parts.