• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 봄 학술발표회논문집(II)
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• pp.637-640
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• 1998

Generally, the durability of the reinforced concrete structures reduce when they are constructed in marine environments. The Mg ions and sulfate ions in seawater cause chemical attacks in concrete and the cracks in concrete result from corrosion of steel due to chlorides. In this study, the mortar specimens made from 5 different types of cement were immersed in artificial seawater of 2 times concentration and then we measured the compressive strength, the length change and the weight change. As a result of this study, we found that the compressive strength ratio decreased in the immersed 56days. We also found the longer the immersed days were, the more the increase of weight ratio and the length change were.

• 한국농림기상학회지
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• 제4권4호
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• pp.197-202
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• 2002

A new method is used to estimate the amount of water evaporation from Class A Pan with higher precision and accuracy. The principle of method is to detect the weight change of a buoyant sinker resulting from a change in water level of Class A Pan. A strain-gauge load cell is used to measure the weight change. Field observation of evaporation was done at Pohang Meteorological Station from June 24 to August 4, 2002. By using this new method, it is possible to measure hourly evaporation accurately even under a strong solar radiation and wind disturbance, enabling a direct comparison of evaporation with other meteorological elements. At night, under low humidity and high wind speed conditions, more evaporation was recorded than during daytime. Maximum evaporation rates observed during this period exceed 1.0 mm/hour under the sunny and windy conditions with low humidity. To understand relationships between meteorological elements and latent heat flux at ground level, we suggest intensive held experiments using high accuracy evaporation recording instruments with hourly time interval.

• 대한전기학회논문지:전력기술부문A
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• 제48권10호
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• pp.1259-1263
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• 1999

In this paper, a method to guarantee system continuity is developed, which can be applied to discontinuity problem in the time domain of restructurable control system. This method can be summarized as input alternation using weight change considering convergence speed of system mode. Input is changed from 'system continuity guarantee input,' which is defined as a input that minimizes the change of state variables, to 'alternative controller input,' which is selected by Neil's PI/EAM[3]. AIDC aircraft model is used for simulation. By showing the waveform of system input and state variable, we can sure that this method is effective for depression of system shock like jerk.

• 한국산학기술학회논문지
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• 제16권5호
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• pp.3353-3360
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• 2015

본 연구는 현역병을 대상으로 BMI 현황과 같은 연령대의 남성에 비해 BMI가 어떤 차이가 있는지 및 현역병의 BMI 변화에 영향을 미치는 요인이 무엇인지 확인하고자 하였다. 연구방법으로는 4개 부대에서 복무 중인 현역병을 대상으로 2009년 2월 23일부터 3월 31일까지 자기기입식 설문을 실시하였다. 통계분석에는 총 301명을 대상으로 독립표본 T-검정, 교차분석 및 다중선형회귀분석이 사용되었다. 연구결과, 현역병의 과체중 비율은 18.6%로 같은 연령대 남성의 22.1%에 비해 낮아 또래 남성에 비해 현역병의 비만율이 낮은 것으로 확인되었다. 건강행태에서는 정상체중 이하 군(2.39)이 과체중군(2.13)보다 식습관 점수가 높아 정상군이 상대적으로 천천히 먹고, 맵고 단것을 덜 먹는 것으로 확인되었다. 과체중군(2.25)이 정상체중 이하 군(2.98)에 비해 자신의 체형에 대한 만족도가 낮은 반면 체중조절활동은 과체중군(4.01)이 정상체중 이하 군(3.37)보다 점수가 유의하게 더 높게 나타났다. BMI 변화에 대한 영향요인으로는 식습관, 주관적 체형인식, 체중조절활동이 확인되었다. 따라서 현역병의 BMI를 향상시키기 위해서는 개인적 노력보다는 단체 급식과 군 내 매점 운영을 개선하여 조직차원에서 비만에 영향을 주는 요인에 접촉하지 못하도록 하는 중재노력 및 올바른 체형인식에 대한 교육, 체중조절활동에 대한 독려가 필요할 것으로 사료된다.

• The Journal of Korean Physical Therapy
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• 제17권1호
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• pp.27-42
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• 2005

This study aims to investigate the effect of Early Weight Bearing and Vibration Exercise and is focusing on the difference between changes if experimental before and after on 30 stroke patients. The obtained results are as follows; First, the chang due to Early Weight Bearing and Vibration in the comparison of experimental duration, Early Weight Bearing and Vibration Exercise showed improvement of Bone Density(P<.05). Second, in the comparison of change according to Early Weight Bearing and Vibration Exercise, Bone Density was significantly changed between two experimental group(P<.05). Third, the chang due to Early Welght Bearing and Vibration Exercise, Bone Density of sound femoral head and affected femoral head was significantly changed(P<.05). Fourth, the chang due to Early Weight Bearing and Vibration Exercise, Bone Density of femoral head was significantly changed between two experimental group(P<.05).

• 한국생산제조학회지
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• 제5권4호
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• pp.121-128
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• 1996

In order to examine spindle deformation characteristics that affects the performance of dynmic cutting acuracy due to tool weight variation in a experimental spindle. thermal deformation value of operrative spindle by the axial displacement and the radial run out was measured according to the rise of spindle temperature through the laps of operation time and the change of rotational speed under the tool weight variation. A qualitative summary is as follows ; 1) The results show that the tool weight affcets the spindle temperature variation in a experimental spindle. 2) Radial run out and axial displacement was measured according to the rise of the spindle temperature and the performance of dynamic cutting accuracy was affected by the tool weight variation. 3) Axial displacement is 1.3 times larger than the radial run out in a experimental spindle conditions. 4) Axial displacement is continuously elongated when the tool weight is repeatly exchanged since the spindle themal deformaion, however, when the same tool weight is used. the displacement is still constant.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.188-195
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• 2022

Although issuing change orders is a common practice in the construction phase of any project, non-structural utility subcontractors are struggling and seek to find a way to reduce change orders. Therefore, this paper presents the analysis results on change orders to cultivate possible suggestions and solutions on how to reduce or minimize change orders in mechanical, electrical, and plumbing (MEP) works. Change orders in non-structural utility works are analyzed based on six categories such as rerouting and change of location, changes in weight, rejected design by Office of Statewide Health Planning and Development, District Structural Engineer, or the Structural Engineer of Record, unforeseen conditions, changed equipment, and owner-initiated change. The analysis findings showed that rerouting and changing location is the most significant cause, followed by unforeseen conditions. The results not only contribute to the existing body of knowledge on change order research area, but also help MEP contractors reduce the time and cost of change orders.

• 한국엔터테인먼트산업학회논문지
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• 제14권5호
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• pp.115-130
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• 2020

본 연구의 목적은 에어로빅댄스 활성화를 위한 체중변화와 운동몰입에 관한 연구를 차이 분석하여 지속적으로 에어로빅댄스 활성화가 되도록 제시하는데 주된 목적이 있다. 이러한 연구 목적을 달성하기 위하여 2020년 4월에 경남에 소재한 일반 에어로빅댄스 회원들을 대상으로 선정하고 비확률표집방법(Non-Probability Sampling)의 하나인 편의표본추출법(Convenience Sampling Method)으로 표본 추출을 이용한 설문지로 시행하였다. 이와 같이 본 연구에서 얻어진 결과는 다음과 같다. 첫째, 인구통계학적 특성은 부분적으로 차이가 높게 나타났다. 연령은 40~49세, 신장은 160cm이상, 직업은 주부, 체중변화는 시작 후, 체중변화량은 -3kg 이상, 참여강도는 100분이상, 참여빈도는 4일, 참여기간은 5년이하가 가장 높게 나타났다. 둘째, 체중변화(신체자신감, 활동자신감, 댄스자신감, 심리안정효과, 댄스활동효과, 수행동작효과)와 운동몰입(행위몰입, 인지몰입)에 부분적으로 높은 차이가 나타났다. 셋째, 체중변화(신체자신감, 활동자신감, 댄스자신감, 심리안정효과, 댄스활동효과, 수행동작효과)와 운동몰입(행위몰입, 인지몰입)에 부분적으로 높은 영향이 미치는 것으로 나타났다.

• Environmental Engineering Research
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• 제12권5호
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• pp.224-230
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• 2007

The objectives of this study were to evaluate the change of molecular weight (MW) profiles in natural organic matter (NOM) through various treatment processes (coagulation, granular activated carbon (GAC), and ozonation) using high performance size exclusion chromatography based on ultraviolet absorbance and dissolved organic detection (HPSEC-UVA-DOC). In addition, relationships between MW profiles and disinfection by-production (DBP) formation were evaluated. Each treatment process results in significant different effects on NOM profiles. Coagulation is effective to remove high molecular weight NOM, while GAC is effective to remove low molecular weight NOM. Ozonation removes only a small portion of NOM, while it induces a significant reduction of UV absorbance due to breakdown of the aromatic groups. All treated waters are chlorinated, and chlorination DBPs such as trihalomethanes (THMs) and haloacetic acids (HAAs) are measured under formation potential conditions. Both THM and HAA formation potentials were significantly reduced through the coagulation process. GAC was more effective to reduce THM formation compared to HAA formation reduction, while ozonation showed significant HAA reduction compared to THM reduction.

• 한국정보처리학회논문지
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• 제1권2호
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• pp.184-193
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• 1994

본 논문은 최소목(Minimum-weight Spanning Tree, MST)에 있어서 네트워크의 랭크 중 몇개가 삭제(또는 파괴) 또는 추가(또는 회복) 되었을 때, MST를 재구성하는 분산 알고리즘을 제안한다. 본 논문에서 제안한 알고리즘의 메세지 복잡도는 Ο(m＋n log(t＋f))이고, 이상시간 복잡도는 Ο(n＋n log(t＋f))가 되며, 여기서 n은 네트워크의 프로세서의 수이고 t(resp. f)는 추가되는 링크의 수(resp. 이전 MST의 삭제된 링크의 수)이다. 그래서 네트워크의 형태가 변형이 된 다음에 f=O이고 m=e일 경우에는 m=t＋n이 된다. 또한 본 논문의 마지막 부분에서는 링크의추가, 삭제와 마찬가지로 프로세서의 추가, 삭제되었을 경우의 알고리즘도 제안한다.