• Computers and Concrete
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• 제8권2호
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• pp.163-176
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• 2011

By virtue of chord-length density function from the field of statistical physics, this paper introduced a quantitative approach to estimate the distribution of cement paste thickness between aggregates in concrete. Dynamics mixing method based on molecular dynamics was employed to generate one model structure, then image analysis algorithm was used to obtain the distribution of thickness of cement paste in model structure for the purpose of verification. By comparison of probability density curves and cumulative probability curves of the cement paste thickness among neighboring aggregates, it is found that the theoretical results are consistent with the simulation. Furthermore, for the model mortar and concrete mixtures with practical volume fraction of Fuller-type aggregate, this analytical formula was employed to predict the influence of aggregate volume fraction and aggregate fineness. And evolution of its mean values were also investigated with the variation of volume fraction of aggregate as well as the fineness of aggregates in model mortars and concretes.

• 유통과학연구
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• 제15권9호
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• pp.85-93
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• 2017

Purpose - The volume and valence of online word-of-mouth(eWOM) have become an important part of the retailer's market success for a wide range of products. This study aims to investigate how the growth of eWOM has generated the product's final financial outcomes in the introductory period influences. Research design, data, and methodology - This study uses weekly box office performance for 117 movies released in the South Korea from July 2015 to June 2016 using Korean Film Council(KOFIC) database. 292,371 posted online review messages were collected from NAVER movie review bulletin board. Using regression analysis, we test whether eWOM incurred during the opening week is valuable to explain the last of box office performance. Three major eWOM metrics were considered after controlling for the major distributional factors. Results - Results support that major eWOM variables play a significant role in box-office outcome prediction. Especially, the growth rate of the positive eWOM volume has a significant effect on the growth potential in sales. Conclusions - The findings highlight that the speed of eWOM growth has an informational value to understand the market reaction to a new product beyond valence and volume. Movie distributors need to take positive online eWOM growth into account to make optimal screen allocation decisions after release.

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권6호
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• pp.95-105
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• 2021

Extensive groundwater abstraction has been recognized as one of the major challenges in management of coastal groundwater. The purpose of this study was to assess potential changes of groundwater distribution of northeastern Jeju Island over 10-year duration, where brackish water have been actively developed. To quantitatively estimate the coastal groundwater resources, numerical simulations using three-dimensional finite-difference density-dependent flow models were performed to describe spatial distribution of the groundwater in the aquifer under various pumping and recharge scenarios. The simulation results showed different spatial distribution of freshwater, brackish, and saline groundwater at varying seawater concentration from 10 to 90%. Volumetric analysis was also performed using three-dimensional concentration distribution of groundwater to calculate the volume of fresh, brackish, and saline groundwater below sea level. Based on the volumetric analysis, a quantitative analysis of future seawater intrusion vulnerability was performed using the volume-based vulnerability index adopted from the existing analytical approaches. The result showed that decrease in recharge can exacerbate vulnerability of coastal groundwater resources by inducing broader saline area as well as increasing brackish water volume of unconfined aquifers.

• 대한교통학회지
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• 제18권5호
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• pp.33-42
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• 2000

본 연구는 도시고속도로 엇갈림 구간에서 나타나는 다양하고 독특한 교통 특성을 분석하는 일련의 연구 중의 한 부분으로서 엇갈림 구간의 차두시간 분포의 특성과 최대 진입 가능 교통량의 산출을 통해 엇갈림 구간의 합리적 설계의 기초를 마련하고자 이루어졌다. 지금까지 합류 구간과 엇갈림 구간에서의 최대 진입 가능 교통량을 산정할 때, 본선 기본 구간의 차두시간 분포가 이용되어 왔다. 그러나 합류 구간 및 엇갈림 구간 진입부에서의 차두시간 분포는 기본 구간의 차두시간 분포와는 다른 특성을 보인다. 본 연구에서는 이를 규명하기 위해 도시고속도로 엇갈림 구간에서 현장조사를 통해 차량 도착 분포 자료를 수집하였고, 본선 교통류뿐만 아니라 진입 교통류의 영향을 반영한 새로운 차두시간 분포 함수를 도출하였다 도출된 차두시간 분포의 검증을 위해서는 관측된 차두시간 분포 자료, 기존에 기본 구간 에 적용되던 차두시간 분포(Pearson Type III 분포), 새로이 개발된 분포에 대하여 카이제곱 검정을 통하여 통계적 검정을 실시하였다. 그 결과. 새로이 개발된 차두시간 분포가 엇갈림 구간 진입부의 차두시간 분포를 가장 정확히 설명할 수 있는 분포로 나타났다. 더불어 본 연구에서는 새로이 개발된 차두시간 분포를 이용하여 연결로에서 본선으로 진입 가능한 최대 진입 가능 교통량을 산출하였으며, 이를 Drew 모형의 결과와 비교하였다.

• 한국전산구조공학회논문집
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• 제14권4호
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• pp.495-503
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• 2001

기능 경사 복합재에서는 열적 탄성 거동이 성분의 구성분포에 의해 명백하게 구분되어지도록 두가지의 성분입자들을 특정한 체적분율 분포에 따라서 혼합한다. 따라서, 설계자는 주어진 제약조건에 대해 목적하는 성능에 적합한 기능 경사 복합재를 설계하기 위해서 최적의 체적분율 분포를 결정해야만 한다. 본 연구에서는 금속과 세라믹으로 구성된 내열 기능 경사 복합재의 2차원 체적분율을 최적화하기 위하여 내부벌칙함수법과 유한차분법을 사용한 수치 최적화기법을 제안하였다. 최적화 효율을 위해 단일 설계변수의 유한개의 균질 사각형 격자로 기능 경사 복합재의 영역을 나누었다. 그렇지만, 연속적인 체적분율을 구현하기 위하여 최적설계 후에 전체적으로 연속적인 이차원 선형함수로써 불연속적인 체적분율을 보간하였다.

• 유통과학연구
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• 제21권9호
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• pp.67-79
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• 2023

Purpose: To investigate the intensity of bilateral international trade of the Silk Road Economic Belt (SREB) countries with Kazakhstan, its relationship with logistics (LPI), to assess their contribution to economic growth and distribution of commodity flows. Research design, data, and methodology: The method of analyzing the bilateral trade flow was applied by using the trade intensity index (TII) and a multidimensional regression model describing the relationship between LPI and its components, TII, the volume of exports and imports, GDP. Results: The nature and directions of the relationship between TII and the key components of logistics, the positive impact of LPI on the intensity of trade are established. It is revealed that the intensity of trade between the countries in the direction of the EAEU-Kazakhstan has a greater impact on the growth of LPI than in the opposite direction. At the same time, the higher the level of trade integration and the volume of GDP, the stronger their impact on the efficiency of logistics and distribution of commodity flows. Conclusions: Effective distribution of commodity flows will require the development of logistics components based on the direction of bilateral trade and the size of countries, the intensification of state reforms in the field of international trade and distribution logistics.

• 한국연소학회지
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• 제8권3호
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• pp.24-30
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• 2003

A convolution algorithm combined with Fourier transformation has been applied to the tomographic reconstruction of asymmetric soot structure to identify the local soot volume fraction distribution. Line-of-sight integrated data from light extinction measurement with multi-angular scanning formed basic information for the deconvolution. Multi-peak following interpolation technique was applied to obtain the effect of increasing number of scanning angles. Height-by-height reconstructed soot volume fraction distribution was compared with laser-induced incandescence signals.

• 태양에너지
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• 제19권3호
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• pp.53-61
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• 1999

We already presented new calculation method about the temperature distribution in hot water pipe flow of the unsteady condition. In this paper, we introduce consequence of the case study to confirm appropriation of the calculation method, and case study performs to establish actual hot water use supposed two model that is; the CWV(constant water volume) and VWV(variable water volume).

• 한국안전학회지
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• 제15권3호
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• pp.52-56
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• 2000

The finite control volume method was utilized to investigate the effects of flow through openings on convection in an enclosure. Flow patterns and temperature distribution were compared for non-dimensional inflow velocity U=20, 40, 60 at Ra=$10^4$ and $5\times10^4$, respectively. The inflow velocity influenced temperature distribution in the enclosure significantly and lowered temperature on the top wall. The flow through openings forced the position of the highest temperature on the top wall to move toward the outflow opening.

• 한국식품저장유통학회지
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• 제6권4호
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• pp.402-405
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• 1999

국내 절화류의 포장 및 유통실태를 조사하고자 부산, 광주, 제주, 충남 및 경기지역을 1997년 10월부터 1998년 2월까지 산지 및 시장을 직접 방문하여 조사하였다. 절화류의 외포장재로는 이중양면 골판지가 주종을 이루고 있었으며 품목별 상자보다는 범용성 상자가 더 많이 사용되고 있었다. 내부포장재로는 재활용 신문지와 폴리에칠렌 필름이 주로 사용되고 있었다. 유통실태는 절화시장에서 도소매가 동시에 이루어지고 있었으며 유통경로는 3가지가 있었는데; 가장 많은 형태가 생산자 $\longrightarrow$ 서울위탁시장을 거쳐 소비자에 이르는 경로로 출하비중은 약 42%에 이른다. 또한, 생산자 $\longrightarrow$ 양재동 화훼공판장 $\longrightarrow$ 도.소매상 $\longrightarrow$ 소비자 경로의 출하비중은 약 18%, 나머지 40%는 생산자 $\longrightarrow$ 산지직.공판장 및 지방위탁시장 $\longrightarrow$ 도ㆍ소매상 $\longrightarrow$ 소비자의 경로였다. 절화류의 유통현대화를 위해서는 규격포장을 사용하여 출하하는 것이 바람직하다고 판단되었다.