• 제목/요약/키워드: change order

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터널공사 사례분석에 의한 설계변경 표준프로세스 구성방안 (Case Study and Standard Process Analysis of Change Order in Design for Road Tunnel Project)

  • 강인석;김동광;정원명;이승렬;김현수
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2005년도 추계학술대회 논문집
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    • pp.1149-1152
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    • 2005
  • Recently, tunnel structure is being widely used in railway or roadway construction projects because earthwork causes large cutting and damages in environmental factors. However, there are many changes of design by different items comparing with design phase in tunnel structure by uncertain drawings. This study develops a standard process for the change of design to reduce change orders in construction phase.

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상변화 축열계의 비정상 해석 (A Study on Two Dimensional Phase Change Problem)

  • 원성필;노승탁
    • 대한설비공학회지:설비저널
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    • 제10권1호
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    • pp.12-21
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    • 1981
  • The Enthalpy Model was verified in order to analyze two- dimensional phase change problems. By using the Enthalpy Model, interface locations, frozen fraction rates, heat flux distribution rut cooled surfaces, and surface-integrated heat flux were purely numerically calculated in rectangular thermal storage units, whose initial condition was saturated liquid and phase change material was cooled on its boundaries by convective heat transfer. The calculations were performed for various Stefan numbers and Biot numbers. The effect on those dimensionless numbers were explained.

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The Cusum of Squares Test for Variance Changes in Infinite Order Autoregressive Models

  • Park, Siyun;Lee, Sangyeol;Jongwoo Jeon
    • Journal of the Korean Statistical Society
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    • 제29권3호
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    • pp.351-360
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    • 2000
  • This paper considers the problem of testing a variance change in infinite order autoregressive models. A cusum of squares test based on the residuals from an AR(q) model is constructed analogous to Inclan and Tiao (1994)'s test statistic, where q is a sequence of positive integers diverging to $\infty$. It is shown that under regularity conditions the limiting distribution of the test statistic is the sup of a standard Brownian bridge. Simulation results are given to illustrate the performance of the test.

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고차고해상도 수치기법을 이용한 초음속 제트 screech tone의 axisymmetric mode 해석 (NUMERICAL ANALYSIS OF AXISYMMETIC SCREECH TONE FROM SUPERSONIC JET USING HIGH-ORDER HIGH-RESOLUTION COMPACT SCHEME)

  • 이인철;이덕주
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2007년도 추계 학술대회논문집
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    • pp.56-59
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    • 2007
  • The screech tone of an underexpanded jet is numerically calculated without any specific modeling for the screech tone itself. A fourth-order optimized compact scheme and fourth-order Runge-Kutta method are used to solve the 2D axisymmetric Euler equation. The Fourier transform of pressure signal at upstream shows the directivity pattern of the screech tone very clearly. Pressure signal is shown to observe the generation of the screech tone. Most importantly, we can simulate the axisymmetric mode change of the screech tone very precisely with the proposed method. It can be concluded that the basic phenomenon of the screech tone including its frequency can be calculated and its mode change can be simulated with inviscid Euler equations.

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저강도 모르타르에 있어 유지류 침지의 영향 (The effect of fat and oil soaking for low-strength mortar)

  • 백철;김민상;문병룡;황찬우;한민철;한천구
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2016년도 추계 학술논문 발표대회
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    • pp.113-114
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    • 2016
  • In this study, various fats and oils were soaked in low-strength mortar to experiment what kind of fats and oils had the worst effect on low-strength mortar; it went as follows. For rate of change in length of fat and oil soaking, there was an increase in the order of pig fat, bio-diesel, grape seed oil, and water; in the case of olive oil it was destroyed within 56 days. For rate of change in mass, there was an increase in the order of bio-diesel, water, pig fat, grape seed oil, and olive oil. For relative motion elastic coefficient, there was a decrease in the order of olive oil, grape seed oil, and water. On the whole, pig fat, bio-diesel, and olive oil were shown to have the worst effect on low-strength mortar.

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다포의 형태 변화에 관한 연구 -조선중기 불교건축의 연화형 공포를 중심으로- (A Study on the Yon-Hwa-Hyong Bracket Sets)

  • 양윤식
    • 헤리티지:역사와 과학
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    • 제33권
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    • pp.256-273
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    • 2000
  • This thesis attempts to investigate the design of the bracket sets(eave-supporters) of Dapo-style architecture(multiple-bracket architecture) in order to discover the change and the characteristic of the Yon-Hwa-Hyong bracket sets. The external shape of eave-supporters has been evolved as following order: Kyo-Du-Hyong, Soe-Seo-Hyong, Cho-Gak-Soe-Seo-Hyong, and Yon-Hwa-Soe-Seo-Hyong. The internal shape has been developed as following order: Kyo-Du-Hyong. Cho-Gak-Hyong and Yon-Hwa-Hyong. Kyo-Du-Hyong represents the 17th century style and Yon-Hwa-Hyong has been used since the mid 18th century. Cho-Gak-Hyong signifies the transformation in the structural and designing role of column section and middle section and there appears a unified aspect in Yon-Hwa-Hyong. The transformation from Kyo-Du-Hyong towards Yon-Hwa-Hyong suggests that this is an intention of symbolizing the Buddhist teachings inside and outside of the eave-supporters. The purpose of this change establishes the Buddhist land.

협업 프로세스의 독립적 변경 보장 규칙 개발 (Integrity Checking Rules for Independent Changes of Collaboration Processes)

  • 김애경;정재윤
    • 산업공학
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    • 제25권1호
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    • pp.79-86
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    • 2012
  • Traditional business process management systems provide verification tools of process models to deploy and automate the models. However, there are not so many studies on how to maintain systematically collaborative process models such as supply chain processes when companies are willing to change and update the collaborative process models. In this paper, we analyze change patterns of collaborative processes and declare 19 change patterns. In addition, we apply the change patterns to the process interoperability patterns in order to identify the change problems in case of independent process changes of collaborative processes. As a result, we devise an independency checking algorithm of process changes in collaborative processes.

응력확대계수측정을 위한 하중에 의한 자속밀도변화의 이론적 해석 (Theoretical Analysis of Change in Magnetic Flux Density Due to Load for Measuring KI)

  • 이정희
    • 한국산업융합학회 논문집
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    • 제6권4호
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    • pp.367-371
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    • 2003
  • In order to determine the effective way of measuring the Mode I stress intensity factor for a material containing a two-dimensional surface crack by means of the alternating current potential drop(ACPD) technique, the change in magnetic flux density between crack surfaces and above the specimen surface due to load was studied theoretically. The magnetic flux density in the air between crack surfaces is uniform and above the specimen surface is not changed by increasing the load in the material. Therefore, the change in potential drop due to load in a measuring system which was designed to induce a large amount of electro-motive force was caused by the change in internal inductance of material, the change in the mutual inductance between internal inductance of material and measuring system and the change in the mutual inductance between internal inductance of material and power supply line.

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일산충적평야의 홀로세 퇴적환경변화와 해면변동 (The Holocene Depositonal Environment and Sea-Level Change at Ilsan Area)

  • 황상일
    • 대한지리학회지
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    • 제33권2호
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    • pp.143-163
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    • 1998
  • In order to clarify the depositional environment and sea-level change at Ilsan area including Gawaji and Saemal valley plains, which is located at the right side in downstream of the Han River, boring data, radiocabon dating and diatom analysis were comprehensively investigated. As a result, the palaeogeographies fo this area altered by the transgressions and regressions after 7,000 y. BP could be restored. The high tide sea-level(mean high water level of spring tide) was arrived ca. 7,000y. BP at the valley plain and risen to ca. 5.5m at ca. 5000y. BP. Since then, the sea-level was kept up the same level to ca. 3,200 BP. The descended sea-level to ca. 2,300 BP was risen up to ca. 5.8m in ca. 1,800 y. BP. It is presumed that such a sea-level change as well as the different sediments in quantity supplied from the river basin of the valley plain could be effected to change diversely the depositional environment of the study area and eventually to the prehistoric human life.

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PRECIS를 이용한 우리나라 기후변화 기상자료의 생성 (Generation of Weather Data for Future Climate Change for South Korea using PRECIS)

  • 이관호
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
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    • pp.54-58
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    • 2011
  • According to the Fourth Assessment Report of the Inter governmental Panel on Climate Change(IPCC), climate change is already in progress around the world, and it is necessary to start mitigation and adaptation strategies for buildings in order to minimize adverse impacts. It is likely that the South Korea will experience milder winters and hotter and more extreme summers. Those changes will impact on building performance, particularly with regard to cooling and ventilation, with implications for the quality of the indoor environment, energy consumption and carbon emissions. This study generate weather data for future climate change for use in impacts studies using PRECIS (Providing REgional Climate for Impacts Studies). These scenarios and RCM (Regional Climate Model) are provided high-resolution climate-change predictions for a region generally consistent with the continental-scale climate changes predicted in the GCM (Global Climate Model).

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