• 제목/요약/키워드: condition (A)

검색결과 54,013건 처리시간 0.074초

시화호의 중금속 오염과 산화-환원 상태의 공간적 차이 (Heavy Metal Contamination and Spatial Differences in Redox Condition of the Artificial Shihwa lake, Korea)

  • 현상민;김은수;팽우현
    • 한국환경과학회지
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    • 제13권5호
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    • pp.479-488
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    • 2004
  • Five sediment cores from the tidal flat of artificial Lake Shihwa are analyzed in terms of sedimentology and geochemistry to evaluate the heavy metal contamination and redox condition of surficial sediment following the Shihwa seawall construction. The variability of concentrations of various elements depends on the depositional environment, and reflects the various redox conditions and sediment provenances. The amounts of Ti and Al and their ratio of Ti/ Al with respect to Li clearly indicate that there is an anthropogenic contribution to the surficial sediment. The high concentrations of heavy metals suggest an anthropogenic contribution at ST. 34 and ST. 22. Concentrations of most elements (Cr, Cu, Zn and Pb) are higher near the Shihwa-Banwol industrial complex than in the central part of Lake Shihwa. Concentrations of heavy metal in surficial sediment near the Shihwa-Banwol industrial complex are two to eight times higher than in the center of Lake Shihwa. Enrichment factors (EF), which are normalized by the unpolluted shale, suggests a significant metallic contamination near the Shihwa-Banwol industrial complex (SBIC). The redox condition is divided into two anoxic and mixed oxi $c_oxic zones based on the carbon:sulfur (C/S) ratios of organic matter and elemental relationships. Correlations among geochemical elements Mn, U and Mo are significantly different from site to site, and may therefore be an indicator of the spatial redox condition. Controlling factors for switching anoxic/oxic conditions are thought to be water depth and the differences in industrial effluent supply. The variations of the Cu/Mn ratio in the sediments confirms above mentioned spatial differences of a redox condition in part, and therefore shows a location-dependence redox condition in sediments at four other sites. The redox condition of the surficial sediment characteristics of the Shihwa Lake are controlled by its geographic location and water depth.th.

Strain-based structural condition assessment of an instrumented arch bridge using FBG monitoring data

  • Ye, X.W.;Yi, Ting-Hua;Su, Y.H.;Liu, T.;Chen, B.
    • Smart Structures and Systems
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    • 제20권2호
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    • pp.139-150
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    • 2017
  • The structural strain plays a significant role in structural condition assessment of in-service bridges in terms of structural bearing capacity, structural reliability level and entire safety redundancy. Therefore, it has been one of the most important parameters concerned by researchers and engineers engaged in structural health monitoring (SHM) practices. In this paper, an SHM system instrumented on the Jiubao Bridge located in Hangzhou, China is firstly introduced. This system involves nine subsystems and has been continuously operated for five years since 2012. As part of the SHM system, a total of 166 fiber Bragg grating (FBG) strain sensors are installed on the bridge to measure the dynamic strain responses of key structural components. Based on the strain monitoring data acquired in recent two years, the strain-based structural condition assessment of the Jiubao Bridge is carried out. The wavelet multi-resolution algorithm is applied to separate the temperature effect from the raw strain data. The obtained strain data under the normal traffic and wind condition and under the typhoon condition are examined for structural safety evaluation. The structural condition rating of the bridge in accordance with the AASHTO specification for condition evaluation and load and resistance factor rating of highway bridges is performed by use of the processed strain data in combination with finite element analysis. The analysis framework presented in this study can be used as a reference for facilitating the assessment, inspection and maintenance activities of in-service bridges instrumented with long-term SHM system.

난류-캐스케이드 상호작용 소음 예측을 위한 Perfectly Matched Layer 을 이용한 내부 입/출구 정상유동 경계조건의 개발 (Development of internal inflow/outflow steady mean flow boundary condition using Perfectly Matched Layer for the prediction of turbulence-cascade interaction noise)

  • 김대환;정철웅
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2012년도 춘계학술대회 논문집
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    • pp.521-526
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    • 2012
  • It is essential for the accurate time-domain prediction of broadband noise due to turbulence-cascade interaction to develop inflow/outflow boundary conditions to satisfy the following three requirements: to maintain the back ground mean flow, to nonreflect the outgoing disturbances and to generate the specified input gust. The preceding study(1) showed that Perfectly Matched Layer (PML) boundary condition was successfully applied to absorb the outgoing disturbances and to generate the specified gust in the time-domain computations of broadband noise due to interaction of incident gust with a cascade of flat-plates. In present study, PML boundary condition is extended in order to predict steady mean flow that is needed for the computation of noise due to interaction of incident gust with a cascade of airfoils. PML boundary condition is originally designed to absorb flow disturbances superimposed on the steady meanflow in the buffer zone. However, the steady meanflow must be computed before PML boundary condition is applied on the flow computation. In the present paper, PML equations are extended by introducing source term to maintain desired mean flow conditions. The extended boundary condition is applied to the benchmark problem where the meanflow around a cascade of airfoils is predicted. These illustrative computations reveal that the extended PML equations can effectively provide and maintain the target meanflow.

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난류-캐스케이드 상호작용 소음 예측을 위한 Perfectly Matched Layer을 이용한 내부 입/출구 정상유동 경계조건의 개발 (Development of Internal Inflow/outflow Steady Mean Flow Boundary Condition Using Perfectly Matched Layer for the Prediction of Turbulence-cascade Interaction Noise)

  • 김대환;정철웅
    • 한국소음진동공학회논문집
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    • 제22권7호
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    • pp.685-691
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    • 2012
  • It is essential for the accurate time-domain prediction of broadband noise due to turbulence-cascade interaction to develop inflow/outflow boundary conditions to satisfy the following three requirements: to maintain the back ground mean flow, to nonreflect the outgoing disturbances and to generate the specified input gust. The preceding study showed that perfectly matched layer(PML) boundary condition was successfully applied to absorb the outgoing disturbances and to generate the specified gust in the time-domain computations of broadband noise due to interaction of incident gust with a cascade of flat-plates. In present study, PML boundary condition is extended in order to predict steady mean flow that is needed for the computation of noise due to interaction of incident gust with a cascade of airfoils. PML boundary condition is originally designed to absorb flow disturbances superimposed on the steady meanflow in the buffer zone. However, the steady meanflow must be computed before PML boundary condition is applied on the flow computation. In the present paper, PML equations are extended by introducing source term to maintain desired mean flow conditions. The extended boundary condition is applied to the benchmark problem where the meanflow around a cascade of airfoils is predicted. These illustrative computations reveal that the extended PML equations can effectively provide and maintain the target meanflow.

피부표면 육안확인을 통한 피부상태 분석법 고찰 (A Study on the Analysis Method of Skin Condition through Visual Confirmation of Skin Surface)

  • 김의향;김현주
    • 융합정보논문지
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    • 제11권5호
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    • pp.267-275
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    • 2021
  • 피부상태는 미용적인 측면에서 중요한 관심사이다. 본 연구는 뷰티산업종사자들이 육안관찰 또는 스마트폰 등으로 촬영된 피부상태 이미지를 통하여 할 수 있는 개략적 피부상태 분석방법에 대하여 고찰하였다. 학술연구정보서비스(RISS)에서 '피부상태'와 관련된 키워드로 검색되는 학위논문과 학술논문 중 주관적 평가와 객관적 평가를 병행한 논문, 육안확인이 가능한 요인들과의 상관관계를 도출한 논문을 선별하였고, 주관적인 피부상태와 객관적 피부측정결과가 일치하는 요인과 피부표면에서 육안확인이 가능한 요인과의 관계를 조사하였다. 연구결과, 주관적·객관적 평가가 일치하는 가장 적합한 요인은 '유분량'이었고, 이는 피부표면에서 육안확인이 가능한 '모공', '피부결', '홍반'과 유의미한 상관관계가 있는 것으로 나타났다. 이를 이용하여 개략적인 피부상태 분석이 가능할 것으로 사료된다.

여대생의 건강상태, 건강개념과 건강증진행위간의 관계 (The Relationship between Health Condition, Health Concept and Health Promoting Behavior in College Women)

  • 박혜숙;김애정
    • 한국간호교육학회지
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    • 제6권2호
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    • pp.218-232
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    • 2000
  • This study was done in order to analyze the relationship between Health condition, Health concept and Health promoting behavior in College Women. The subjects were 275 students from a college in Kyungbuk. The instruments used for this study were made of General characteristics (8 items), Health condition (3 item), Health concept (20 items) and Health promoting behaviors (40 items). The data were analyzed by SPSS/PC+ program using descriptive statistics, ANOVA, Pearson's Correlation Coefficient and Multiple Stepwise Regression. The results of this study were as follows. 1. The mean score of the Health promoting behavior was 2.3604. Among the subcategories, the highest degree of performance was interpersonal support (2.9133). 2. Health condition, Heath concept and Health promoting behavior according to general characteristics were as follows. 1)Perceived health condition had statistically significant differences according to board & lodging and living together (p=.040, p=.027). 2)Health concept had a statistically significant differences according to religion (p=.006). 3)Health promoting behavior had statistically significant differences according to age(p=.005). 4)Among the subcategory of Health promoting behavior, statistically significant differences were founded between nutrition and age / board & lodging (p=.004, p=.040), between self actualization and age(p=.006), between health responsibility and age/social economic status(p=.013, p=.000). 5. Correlations of Health condition, Health concept and Health promoting behavior were as follows. 1) BMI was positively correlated with perceived health status(r=.145, p=.015). 2)Health concept was positively correlated with BMI(r=.136, p=.032), perceived health condition(r=.148, p=.015), health promoting behavior (r=.316, p=.000). 6. Correlations of Health condition, Health concept and subcategories of Health promoting behavior were as follows. 1) Perceived health status was positively correlated nutrition (r=.168, p=.006). 2) Health concept was positively correlated with nutrition, stress management, self actualization and interpersonal relationship (r=.153 p=.011, r=.217 p=.000, r=.354 p=.000, r=.193 p=.001). 7. Health concept explained 10.1% of the variance for Health promoting behaviors.

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고관절 내회전 보행이 둔부 근육과 척추 기립근의 근활성도에 미치는 영향 (Effects of the Hip Internal Rotation Gait on Gluteal and Erector Spinae Muscle Activity)

  • 권오윤;원종혁;오재섭;이원휘;김수정
    • 한국전문물리치료학회지
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    • 제13권1호
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    • pp.24-31
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    • 2006
  • The purpose of this study was to identify the effect of the hip internal rotation on gluteal and erector spinae muscle electromyographic (EMG) activity during treadmill walking. Eleven healthy subjects were recruited. All subjects performed treadmill walking while maintaining the hip in neutral position (condition 1) and in internal rotation (condition 2). Surface EMG activity was recorded from four muscles (gluteus maximus (GM), gluteus medius (GMED), tensor fascia latae (TFL), and erector spinae (ES)) and the hip internal rotation angle was measured using a three dimensional motion analysis system. The gait cycle was determined with two foot switches, and stance phase was normalized as 100% stance phase (SP) for each condition using the MatLab 7.0 program. The normalized EMG activities according to the hip rotation (neutral or internal rotation) were compared using a paired t-test. During the entire SP of treadmill walking, the EMG activities of GM in condition 1 were significantly greater than in condition 2 (p<.05). The EMG activities of TFL and ES in condition 2 were significantly greater than in condition 1 (p<.05). The EMG activities of the GMED in condition 1 were significantly greater than in condition 1 (p>.05) except for 80~100% SP. Further studies need randomized control trials regarding the effect of hip internal rotation on the hip and lumbar spine muscle activity. Kinetic variables during gait or going up and down stairs are also needed.

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정기용선에 있어서 용선료 연체의 효과 - 영국 판례를 중심으로 - (Is it a Condition? : The Effect of a Charterers' Failure to pay Hire on time in a Time Charter)

  • 이창재
    • 무역상무연구
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    • 제70권
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    • pp.39-65
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    • 2016
  • On 2013 the English court delivered a decision that the payment obligation under time charter party is a condition. According to this judgement, The Astra, a breach of the obligation to pay hire on time entitles the owner both to withdraw the ship and sue the charterers for damages for the difference between the contract and market rate for the remainder of the contracted period. On 2015, however, the English court stood at the other side. In Spar Shipping, the court confirmed that the obligation to pay hire is not a condition of the contract but an "innominate term" - from the charterers' breach ship owners can exercise their contractual right to withdraw, but owners' right to sue for damages depends on whether the charterers have deprived the owners of the substantial benefit of the contract, or shown an intention to do so. This article aims to compare both decisions over the points that (1) the importance of on-time payment under a time charter party, (2) as a critical and main question in this article, whether the mattered payment clause is a condition or innominate term, (3) whether the on-time payment clause is merely a penalty or a reasonable liquidated damage. Based on various reasons, I am on a position that the payment of hire is not a condition but an innominate term. Default in punctual payment by a charterer, in the absent of clear contractual agreement, needs to be decided further whether that breach removes the substantial benefit of the contract from the owners.

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피삭제와 공구재종의 상관관계에 근거한 절삭조건의 최적화(II) (Optmization of Cutting Condition based on the Relationship between Tool Grade and Workpiece Material (2nd. Report))

  • 한동원;고성림
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1995년도 추계학술대회 논문집
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    • pp.169-172
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    • 1995
  • In optmizing cutting condition for face milling operation, tool wear is an important maching factor. For the purpose of establishing the relationship between various maching factor and tool wear, cutting tests have been performed. As a result, hardness and chemical composition of workpiece material, chemical compositition and grain size of cutting tool and cutting speed have been selected as machining factor. In addition, relationship between feed rate and workpiece hardness has been observed. Prior to utilizing cutting condition recommended by 'Machining Data Hardbook(MDH)' as a Knowledge base, an analysis for the validity has been provided. Based on this analysis, tool life criteria applied by MDH has been modifiied. Finaly, using MDH recommended data for neural network trainning, we can compensate the result form the trained neural network for optimizing cutting condition for some given workpice and cutting tool.

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알루미늄 판 표면에 용사된 Al/SiC의 마모 거동 (Wear Behavior of Al/SiC in Thermal Spray Process)

  • 김형자;유만희;이성호;이광진
    • 동력기계공학회지
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    • 제10권2호
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    • pp.111-116
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    • 2006
  • Tribologcal property of the ceramics used in severe condition was investigated and both $Al_2O_3$ ball and Al/SiC composite made by thermal spray process[TSP] were used as a specimen in this study. Four kinds of material couple in ball and disk specimens were tested in the dry condition by using ball-on-disk type tribo-tester. Friction coefficient, surface roughness, wear rate, and photograph of the worn surface were investigated. Generally, High SiC contents[$40{\sim}50%$] specimens showed very low friction coefficient below 0.05 and little wear rate in dry condition. And also, low SiC contents[0%] specimens showed a moderate wear rate and high coefficient of friction at the same condition.

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