• Title/Summary/Keyword: Scale Effect

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Analysis of Size Effect of Nano Scale Machining Based on Normal Stress and Indentation Theories (수직응력과 압입이론에 기반한 나노스케일 기계가공에서의 크기효과 분석)

  • Jeon, Eun-chae;Lee, Yun-Hee;Je, Tae-Jin
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.6
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    • pp.1-6
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    • 2018
  • Recently nano meter size pattern (sub-micro scale) can be machined mechanically using a diamond tool. Many studies have found a 'size effect' which referred to a specific cutting energy increase with the decrease in the uncut chip thickness at micro scale machining. A new analysis method was suggested in order to observe 'size effect' in nano scale machining and to verify the cause of the 'size effect' in this study. The diamond tool was indented to a vertical depth of 1,000nm depth in order to simplify the stress state and the normal force was measured continuously. The tip rounding was measured quantitatively by AFM. Based on the measurements and theoretical analysis, it was verified that the main cause of the 'size effect' in nano scale machining is geometrically necessary dislocations, one of the intrinsic material characteristics. st before tool failure.

Wind Tunnel Test for Scaled Wind Turbine Model (Scale effect correction) (축소형 풍력터빈 풍동시험-축소효과 보상기법)

  • Cho, Tae-Hwan;Kim, Yang-Won;Park, Young-Min;Chang, Byeong-Hee
    • New & Renewable Energy
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    • v.4 no.2
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    • pp.87-93
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    • 2008
  • Wind tunnel test for the 12% scaled model of NREL Phase VI wind turbine was conducted in KARI low speed wind tunnel for $2006{\sim}2007$. The 1st and 2nd test was designed to find out the wind tunnel test method for the blade manufacturing accuracy and surface treatment method by using the composite and aluminum blades. And the 3rd test was designed to study the scale effect. The chord extension method which was used for Bo-105 40% scaled model was adapted for scale effect correction. Test results shows that the chord extension method works well for the torque slope but the maximum torque for scaled model is about 8% below than the real scale model. New correction method to correct this offset was proposed.

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The Clinical Study on the Effect of Acupotomy on Chronic Arthritis of Ankle (침도침 시술을 시행한 만성 족관절 염좌 환자 2례에 대한 증례보고)

  • Kim, Min-Jung;Hong, Kwon-Eui
    • Journal of Acupuncture Research
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    • v.25 no.4
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    • pp.157-162
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    • 2008
  • Objectives : The purpose of this study is to report the effect of acupotomy for patients with chronic arthritis of ankle. Methods : We treated Two patients who have chronic arthritis of ankle with acupotomy. To check the effect and satisfaction of acupotomy we used visual analog scale(VAS) and Five-point Likert scale. At the same time, we measured Change of ankle range of motion(ROM). Results : As a result of evaluation by using VAS, after treatment VAS score decreased(VAS3, VAS5). ROM of ankle widened. And the Likert scale point were checked 3 and 4. Conclusions : This study shows acupotomy has useful effect on chronic arthritis of ankle. An acupotomy is an alternative effective treatment modality for chronic arthritis of ankle.

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A Study on Competition Analysis in Retail Distribution Industry Using GIS in Seoul

  • YOO, Byong-Kook;KIM, Soon-Hong
    • Journal of Distribution Science
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    • v.19 no.3
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    • pp.49-60
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    • 2021
  • Purpose: This study aims to utilize geographic data to analyze how various retail formats of large-scale stores around the traditional market affect the performance of the traditional market in Seoul, Korea. Research design, data, and methodology: The two types of catchment areas were demarcated (circle of 1km radius and Thiessen polygon) for each traditional market, and the large-scale stores located within each catchment area were identified for 153 traditional markets in Seoul, Korea. Additionally, multiple regression analysis was utilized. Results: The results revealed that the influence on the performance of the traditional markets were different depending on the retail format of the large-scale stores. Large discount stores were found to have a negative effect on the sales and the visitors of traditional markets, whereas complex shopping malls and department stores had a positive effect on the traditional markets. Conclusions: As a result of the differences in the retail format such as product categories and leisure functions, the impact of some large-scale stores on the traditional market may have a greater agglomeration effect than the consumer churn effect. Therefore, it is suggested that in the regulation of these large-scale stores, the differences in retail format should be considered for the future.

Model Tests on the Bearing Capacity and Settlement of Footing Considering Scale Effect (Scale Effect를 고려한 기초의 지지력 및 침하량 산정을 위한 모형실험)

  • 정형식;김도열;김정호
    • Journal of the Korean Geotechnical Society
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    • v.19 no.5
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    • pp.343-354
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    • 2003
  • The scale effect should be considered to determine the bearing capacity and settlement of footings from Plate-Load Test, because of the size difference between a footing and a loading plate. To analyze characteristics of bearing capacity and settlement according to the difference of loading plate sizes, model tests were performed with four different sizes of square plate, which are B=10, 15, 20 and 25cm, on five different kinds of subsoil. Based on the analyzed results, this paper also proposes a method of bearing capacity and settlement determination, where scale effect is considered depending on the mixing ratio of sand and clay. Until now, uneconomic constructions have been conducted because of unreasonable evaluation in estimating bearing capacity and settlement of footings from Plate-Load Test in fields. In the application of the formula proposed in this research to field problems, it is expected that evaluation of bearing capacity and settlement of footings can be more reliable and more economic construction can be achieved.

Influence of Reynolds Number and Scale on Performance Evaluation of Lift-type Vertical Axis Wind Turbine by Scale-model Wind Tunnel Tests

  • Tanino, Tadakazu;Nakao, Shinichiro;Miyaguni, Takeshi;Takahashi, Kazunobu
    • International Journal of Fluid Machinery and Systems
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    • v.4 no.2
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    • pp.229-234
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    • 2011
  • For Lift-type Vertical Axis Wind Turbine (VAWT), it is difficult to evaluate the performance through the scale-model wind tunnel tests, because of the scale effect relating to Reynolds number. However, it is beneficial to figure out the critical value of Reynolds number or minimum size of the Lift-type VAWT, when designing this type of micro wind turbine. Therefore, in this study, the performance of several scale-models of Lift-type VAWT (Reynolds number : $1.5{\times}10^4$ to $4.6{\times}10^4$) was investigated. As a result, the Reynolds number effect depends on the blade chord rather than the inlet velocity. In addition, there was a transition point of the Reynolds number to change the dominant driving force from Drag to Lift.

Understanding the Effect of Different Scale Information Fusion in Deep Convolutional Neural Networks (딥 CNN에서의 Different Scale Information Fusion (DSIF)의 영향에 대한 이해)

  • Liu, Kai;Cheema, Usman;Moon, Seungbin
    • Proceedings of the Korea Information Processing Society Conference
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    • 2019.10a
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    • pp.1004-1006
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    • 2019
  • Different scale of information is an important component in computer vision systems. Recently, there are considerable researches on utilizing multi-scale information to solve the scale-invariant problems, such as GoogLeNet and FPN. In this paper, we introduce the notion of different scale information fusion (DSIF) and show that it has a significant effect on the performance of object recognition systems. We analyze the DSIF in several architecture designs, and the effect of nonlinear activations, dropout, sub-sampling and skip connections on it. This leads to clear suggestions for ways of the DSIF to choose.

A Study for the Effect of Air Traffic Controller's Individual and Team Response against Emergency Situation on Organizational Effectiveness (비정상상황에 대한 항공교통관제사의 개인 및 팀 차원의 대응이 조직효과성에 미치는 영향 연구 : 인지전략 구성요인을 중심으로)

  • Jeon, Jong-Duk;Lee, Nam-Ryung;Lee, Jin-Sook;Park, Sung-Sik
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.26 no.1
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    • pp.10-24
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    • 2018
  • This paper tried to analyze the response of air traffic controller(ATC) against abnormal situations using survey based on cognitive strategies suggested by Malakis et al.(2010). The survey designed to empirically analyze the effect of the cognitive strategy factors on organizational effectiveness. The main purpose of this research was as follows: First, it was analyzed both the individual-scale and team-scale factors which constructed the cognitive strategy against abnormal situations. Secondly, how seriously impact the ATC's cognitive strategies on their organizational effectiveness. The organizational effectiveness was divided into such two latent variables as job absorption and job satisfaction. According to the a analysis, it was proven that premeditated act of ATC had a positive significant effect on team-scale cognitive strategies such as teamwork, communication and error management. Moreover, it was found out the team-scale cognitive strategies had also a positive significant effect on job absorption. On the other hands, individual-scale cognitive strategies had no or negative effect on job absorption. Job absorption was proven to have a significant effect on job satisfaction of ATC.

Analgesic Effect of Electroacupuncture after Femoral Head Osteotomy in Dogs (개에서 대퇴골두 제거술 후 전침 자극이 통증완화에 미치는 영향)

  • Choi In-young;Cheong Jongtae;Shin Taekyun;Lee Joo-myoung
    • Journal of Veterinary Clinics
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    • v.21 no.4
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    • pp.374-397
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    • 2004
  • This experiment was designed to investigate the analgesic effect of non-invasive electroacupuncture treatment on femoral head osteotomy in dogs. Twelve dogs were divided into 3 groups in this experiment. Electroacupuncture group was non-invasively electrostimulated in Huan Tiao (GB-30) acupoint for 10 minutes by 4.5V, 5Hz for 10 days. Medication group was treated with carprofen (4mg/kg, P.O.) for 10 days. Control group was not treated. Each group was pre-operatively and post-operatively scored by using VAS (Visual Analogue Scale), SDS (Simple Descriptive Scale), NRS (Numerical Rating Scale), and measured serum cortisol levels. The results of VAS, SDS and NRS in electroacupuncture and medication groups were better than those of control group. And, the results of electroacupuncture group were better than those of medication group since 6th day after osteotomy in pain management(p<0.05). But, there were no significances in serum cortisol level among 3 groups. In conclusion, non-invasive electroacupuncture treatment showed sufficient analgesic effect on postoperative pain management after femoral head osteotomy, and VAS, SDS, and NRS scoring system would be adapted in evaluation of pain management.