• Title/Summary/Keyword: 비대칭적 변화

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A Generalized Model for the Prediction of Thermally-Induced CANDU Fuel Element Bowing (CANDU 핵연료봉의 열적 휨 모형 및 예측)

  • Suk, H.C.;Sim, K-S.;Park, J.H.
    • Nuclear Engineering and Technology
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    • v.27 no.6
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    • pp.811-824
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    • 1995
  • The CANDU element bowing is attributed to actions of both the thermally induced bending moments and the bending moment due to hydraulic drag and mechanical loads, where the bowing is defined as the lateral deflection of an element from the axial centerline. This paper consider only the thermally-induced bending moments which are generated both within the sheath and the fuel and sheath by an asymmetric temperature distribution with respect to the axis of an element The generalized and explicit analytical formula for the thermally-induced bending is presented in con-sideration of 1) bending of an empty tube treated by neglecting the fuel/sheath mechanical interaction and 2) fuel/sheath interaction due to the pellet and sheath temperature variations, where in each case the temperature asymmetries in sheath are modelled to be caused by the combined effects of (i) non-uniform coolant temperature due to imperfect coolant mixing, (ii) variable sheath/coolant heat transfer coefficient, (iii) asymmetric heat generation due to neutron flux gradients across an element and so as to inclusively cover the uniform temperature distributions within the fuel and sheath with respect to the axial centerline. As the results of the sensitivity calculations of the element bowing with the variations of the parameters in the formula, it is found that the element bowing is greatly affected relatively with the variations or changes of element length, sheath inside diameter, average coolant temperature and its variation factor, pellet/sheath mechanical interaction factor, neutron flux depression factor, pellet thermal expansion coefficient, pellet/sheath heat transfer coefficient in comparison with those of other parameters such as sheath thickness, film heat transfer coefficient, sheath thermal expansion coefficient and sheath and pellet thermal conductivities.

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A Study on Aesthetic Response on Symmetric Balance & Asymmetric Balance by Involvement (관여수준에 따른 대칭적 균형과 비대칭적 균형의 심미적 반응에 관한 연구)

  • 이진렬;홍정표;김진아
    • Archives of design research
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    • v.15 no.3
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    • pp.73-82
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    • 2002
  • This research suggests relative perspective against to the existing researches which consider balance as mere one of aesthetic elements that balance could lead different consumer aesthetic response according to product characteristics. From the results of this study, we can suggest that higher level of balance encourage positive consumer aesthetic response in high involvement products and contrary, lower level of balance encourage positive consumer aesthetic response. It's expected for the results of this study to suggest more useful design approach in theoretical and practitional fields. In the future researches, more profound studies with more number of stimuli, more levels of balance distortion and more number of moderating variables should be peformed to withdraw more useful results.

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The effects of MMH task conditions on muscle activity and fatigue of the trunk musculature (MMH 작업조건에 따른 몸통부위 근육군의 활동변화에 관한 연구)

  • 이욱기;김상호;정민근
    • Proceedings of the ESK Conference
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    • 1993.10a
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    • pp.223-235
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    • 1993
  • 요통(Lowback Pain)을 유발하는 주요원인으로 알려져있는 MMH(Manual Materials Handling) 작업에 있어서 작업조건의 변화가 근육의 활동과 피로도에 미치는 영향을 평가하기 위해 4가지 서로 다른 작업조건하에서 몸통부위(Trunk)의 주요근육에 대한 EMG 파형분석을 실시 하였다. 본 연구에서의 분석대항작업은 실제 작업조건과 유사하레 설계된 120분간의 단속적인 인양(Lifting)/하역(Lowering) 작업으로서 작업중량은 작업자의 MVIS(Maximum Voluntary Isometric Strength)를 기준으로 설정되었으며, 매 10분 간격으로 EMG 측정이 이루어졌다. 작업물이 작업자의 정면에 위치한 대칭형(Symmetric) 작업의 경우 배면부(Dorsal) 근육인 천극근(Erector Spinae)과 활배근(Latissimus Dorsi)이 활동근(Active Muscle)인 것으로 나타났으며, 정중면(Medial Plane)을 중심으로 좌우측 근육이 동일한 근력을 발휘하였다. 작업물이 작업자의 한쪽 측면에 위치한 90도 비대칭형(Asymmetric) 작업의 경우 천극근과 활배근외에 작업물과 반대쪽 외사근(External Oblique)이 활동근으로 추가되었으며, 작업물과 반대쪽의 근육들이 더욱 큰 근력을 발휘하였다. 작업의 반복에 따른 근육의 피로도를 평가하기 위해 실시한 EMG 파형의 Spectral Analysis 결과, 비대칭형 작업시 작업물과 반대쪽의 천극근에서 작업시간의 경과에 따라 중위주파수(Median Power Frequency)가 저주 파수대로 천이(Lower Shift)하는 현상이 나타났으며, 일정한 작업량이라도 작업중량을 줄이고 작업 빈도를 높여서 작업할 경우에 이러한 현상이 더욱 두드러졌다. 작업시간의 경과에 따른 MVIS의 감소 현상은 작업빈도가 높고 비대칭형 작업일 때 가장 크게 나타났다. 총손실을 줄이고, 상대적 비용절감효과를 갖게할 수 있다고 하였다. 따라서 본 연구에서는 성인 여성기성복의 치수적합성을 높이기위하여 출산 후 중년에 접어 들면서 체형이 변화되는 것을 고려하여 연령을 분류하고(18세-34세, 30세-51세), 각 연령 집단에 따른 체형을 각각 3가지로 분류하였다. 이에 따라 의복 생산시의 총손실을 줄이기위한 상의, 하의생산시 필요한 부위별 최적규격치 간격을 제시하였다.적인 기능으로 보여지는 것에 좁혀서 작업능력의 연령증가 변화에 대하여다원적 평가를 하는 것이 실제적이라고 할 수 있다. 따라서 본 연구에서는 인간이 가지고 있는 다수의 기능중에서 수지교 치성과 연령증가와의 관계를 조사한다. 만약 연령증가 만으로 수지교치성을 평가 할 수 없는 경우에는 어떠한 요인이 수지기민성의 변화에 영향을 미치는가를 검토한다.t list)에서 자동적으로 사건들의 순서가 결정되도록 확장하였으며, 설비 제어방식에 있어서도 FIFO, LIFO, 우선 순위 방식등을 선택할 수 있도록 확장하였다. SIMPLE는 자료구조 및 프로그램이 공개되어 있으므로 프로그래머가 원하는 기능을 쉽게 추가할 수 있는 장점도 있다. 아울러 SMPLE에서 새로이 추가된 자료구조와 함수 및 설비제어 방식등을 활용하여 실제 중형급 시스템에 대한 시뮬레이션 구현과 시스템 분석의 예를 보인다._3$", chain segment, with the activation energy of carriers from the shallow trap with 0.4[eV], in he amorphous regions.의 증발산율은 우기의 기상자료를 이용하여 구한 결과 0.05 - 0.10 mm/hr 의 범위로서 이로 인한 강우손실량은 큰 의미가 없음을 알았다.재발이 나타난 3례의 환자를 제외한 9례 (75%)에서는 현재까지 재발소견을 보이지 않고 있다. 이러한 결과는 다른 보고자들과 유사한 결과를

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Retirement Behaviors of Two Wage Earners Households (맞벌이가구의 은퇴행태에 대한 실증분석)

  • Choi, Seung-Hyun
    • Journal of Labour Economics
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    • v.29 no.1
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    • pp.129-152
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    • 2006
  • The purpose in this study is to analyze the effect of expected public pension assets (or social security wealth) and retirement incentives on retirement behaviors of two wage earners households. For the purpose of the study, an empirical analysis was conducted. In the empirical step, it was found that the empirical results were significant for men, but not for women namely, statistically asymmetric if behaviors of two couples are interdependent. The cause for the statistically asymmetric results were then determined. The Bivariate Probit model was used for estimation in the first step and the KLIPS(Korean Labor and Income Panel Study) was used as data for estimation. According to the empirical analysis, the results showed statistically significant asymmetry for men, however not for women, in expected public pension assets and other retirement incentives, non-wage assets, age difference, spouse's health status, spouse's monthly wages per hour and aging of their spouse In this study, cause of statistically asymmetric result in asymmetric complementarities of leisure of couples were found, then explained through different methods of comparison from the most recent studies. First, spouse's cross wage elasticity of self leisure demand(retirement) was calculated and determined whether complementarities of leisure of couples is positive or negative. Then, the degree of complementarities of leisure was distinguished in comparison with the relative size of two cross elasticities. Thus, men have relatively strong complementarities of leisure. But for women, it may roughly cancel out due to the substitution effect and the income effect. Therefore, women have relatively weak complementarities of leisure.

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A Study on Characteristics of Flood Flow at a Channel Confluence Connected Asymmetrically with Four Channels (네 개의 수로가 비대칭으로 연결된 수로 합류부에서의 홍수흐름 특성에 관한 연구)

  • Jeong, Woo Chang
    • Journal of Korea Water Resources Association
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    • v.46 no.7
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    • pp.767-781
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    • 2013
  • In this study, the hydraulic model experiments and numerical simulations are carried out to analyze the flood flow characteristics in and around a channel confluence connected asymmetrically with four channels. The numerical model applied in this study is ANSYS CFX (ver. 14) which is the commercial three-dimensional CFD model. As results of comparison between the measured and simulated water depth distributions in and around a channel confluence, the agreement is relatively well satisfied. It can be shown in this study that the water surface profiles in and around a channel confluence are significant different with the two channel directions in which the water are entering and increased inflow.

Horizontal Earth Pressure of the Backfill in the Narrowly Excavated Ground Considering Various Boundary Conditions (좁게 굴착된 뒤채움 지반의 경계조건에 따른 수평응력 변화에 관한 연구)

  • Kim, Hee Su;Ban, Hoki;Moon, Chang-Yeul
    • Journal of the Korean GEO-environmental Society
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    • v.18 no.11
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    • pp.19-26
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    • 2017
  • When narrowly excavated in the urban area, the wall of backfill space is not only symmetrical but also asymmetrical. In this case, the horizontal stress induced by backfilling depends mostly on the wall asymmetry and the wall friction angle. Therefore, in this study, the model test in the laboratory was conducted to investigate horizontal earth pressure with depth considering various boundary conditions such as base width, wall friction, relative density of backfill, and wall angle. As the wall is smoother and wall angle is lower from the bottom, the results showed higher the horizontal stresses due to the increase of vertical stresses.

Treatment of patients with midline discrepancies using three-piece basal archwire (Three-piece basal archwire를 이용한 치열 정중선 불일치의 교정치료)

  • Kim, Seok-Jun;Son, Woo-Sung
    • The korean journal of orthodontics
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    • v.30 no.4 s.81
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    • pp.377-386
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    • 2000
  • At the finishing stage, the use of asymmetric elastics to treat mild skeletal and dental midline discrepancies often creates several side effects such as canted occlusal plane, tipped incisors and unesthetic results. This report presents the clinical cases with midline discrepancies, following a differential diagnosis, optimal mechanics, and considerations in treatment. Differential diagnosis and treatment mechanics with three-piece basal archwire can obtain predictable midline correction with minimal side effects.

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태양전지 패시베이션층을 위한 스퍼터링 되어진 DLC:Ti 박막의 물리적, 전기적 특성

  • Park, Yong-Seop;Lee, Su-Ho;Lee, Jae-Hyeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.446-446
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    • 2014
  • 흑연(graphite)과 티타늄(titanum; Ti) 타겟이 양쪽에 부착되어 있는 비대칭 마그네트론 스퍼터링 장치를 이용하여 Ti이 도핑되어진 다이아몬드상 탄소박막(Ti doped Diamond-like carbon, DLC:Ti)을 증착하였다. 흑연과 티타늄 타겟의 파워는 고정하고 기판에 음의 DC 바이어스를 인가하여 DC 바이어스 변화에 따른 DLC:Ti 박막을 증착하였다. 증착되어진 박막의 음의 DC 바이어스의 변화에 따라 변화되어지는 경도와 마찰계수, 표면의 거칠기, 접촉각 등의 물리적 특성들을 분석하였으며, XPS와 라만등의 분석법을 이용하여 박막의 구조적 특성을 분석하였으며, 패시베이션 층을 위한 전기적 특성등을 평가하여 이들 특성들간에 관계를 고찰하였다.

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Effect of Facet Tropism on the Degeneration of the Cervical Facet Joint and Intervertebral Disc (경추의 후관절 퇴행과 추간판 퇴행에서 후관절 비대칭성의 영향)

  • Chung, Sung Soo;Park, Chan-Ho;Heo, Ki Seong
    • Journal of the Korean Orthopaedic Association
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    • v.56 no.5
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    • pp.413-418
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    • 2021
  • Purpose: To investigate the effect of facet tropism on the degeneration of facet joint and intervertebral disc in the cervical spine. Materials and Methods: From January 2017 to December 2018, cervical tropism of 100 patients at the C5/6 level was analyzed retrospectively. In computed tomography (CT), the orientation and tropism of the facet joint with respect to the sagittal, coronal, and horizontal planes were measured. Regression of the facet joint in magnetic resonance imaging (MRI) and CT was assessed using a grading system. Intervertebral disc degeneration was assessed and divided into five grades on MRI. For the left and right asymmetry, a difference between two facet angles of less than 7° was classified as the control group, more than 7° was classified as the tropism group. Results: The mean age of the patients was 55.44±12.3 years (31-81 years) in the tropism group and 55.66±10.7 years (32-76 years) in the control group. In the tropism group, 32 were male and 18 were female. In the control group, 24 were male and 26 were female. Facet joint degeneration was identified in 24 patients (48.0%) in the tropism group and 14 patients (28.0%) in the control group, showing a significant difference. Intervertebral disc degeneration was identified in 29 patients (58.0%) in the tropism group and 17 patients (34.0%) in the control group, showing a significant difference. Multivariate revealed, tropism to be a factor that affected the facet joint and intervertebral disc degeneration. Conclusion: Facet joint and intervertebral disc degeneration occurred significantly in the tropism group, and tropism is a factor affecting the degeneration of facet joint and intervertebral disc in the C5/6 level.

The Relation between Wage and Price Under Low Inflation Rate (저(低)인플레이션하의 임금과 물가의 관계에 대한 연구)

  • Yi, Hyun Chang
    • Journal of Labour Economics
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    • v.29 no.3
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    • pp.49-74
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    • 2006
  • Even though the foreign currency crisis in 1997 and the introduction of Inflation Targeting(IT) have been considered as key factors for current low inflation, there have been few attempts to explain what is the contribution of the dynamics of wage and price to the low inflation. This study is to analyze the relation between wage and price especially focusing on how it through the economic events using cointegration instability tests. The result shows that the short and long-run relation between two have variables have changed through the period of 1997~1999. In the first subperiod, wage tended to respond immediately to inflation shocks, whereas price responded to wage shocks in a long-run. Moreover, the cointegration coefficient of price was equal to 1. In the second subperiod, however, the dynamics from price to wage has been weakened and the real wage has declined apparently. These findings mean that the workers have failed to raise their wage at the rate of inflation, that is, the so-called wage-price spiral was broken for the second subperiod. The implication of this study is that the relatively weak bargaining power of workers, or the condition of labor market, is one of the primary factors of the current low inflation.

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