• 대한기계학회논문집A
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• 제26권2호
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• pp.254-259
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• 2002

A variable air-gap type system is widely used for inductive precision position measurement systems. This type transducer has high sensitivity but lacks a linear measurement range due to structural nonlinearity. Furthermore, as measurement range increases, linearity error is also increased. The alternative is a variable overlap-area type system. The sensitivity of this type is determined by the initial air-gap dimension, keeps the original value and does not deteriorate linearity in spite of the variations of the measuring range.

• 제어로봇시스템학회논문지
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• 제5권6호
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• pp.764-776
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• 1999

In this paper, a tracking algorithm for a maneuvering single target in the presence of multiple data from multiple sensors is investigated. Allowing individual sensors to function by themselves, the estimates from individual sensors on the same target are fused for the purpose of improving the state estimate. The filtering method adopted in the local sensors is the variable dimensional filter with input estimatio technique, which consists of a constant velocity model and a constant acceleration model. A posteriori probability for the maneuvering hypothesis is newly derived. It is shown that the relation function of the a posteriori probability is a function of only the covariance of the fused estimates. Simulation results are provided.

• 설비공학논문집
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• 제13권1호
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• pp.38-47
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• 2001

The operation characteristics of variable conductance heat pipe(VCHP) were numerically investigated by using 1-dimensional diffuse-front model. For different boundary conditions, the amount of non-condensible gas charge and dimension of gas reservoir were obtained by iterative calculation. It is found that the amount of non-condensible gas charge and dimensions of gas reservoir have an effect on the temperature control of condenser for the given operating condition of VCHP. The numerical results show that VCHP has an excellent capability of temperature control when subjected to a change in the heat input.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.597-601
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• 2008

Three-dimensional structures of detonation wave propagating in circular tube were investigated. Inviscid fluid dynamics equations coupled with a conservation equation of reaction progress variable were analyzed by a MUSCL-type TVD scheme and four stage Runge-Kutta time integration. Variable-$\gamma$ formulation was used to account for the variable properties between unburned and burned states and the chemical reaction was modeled by using a simplified one-step irreversible kinetics model. The computational code was parallelized based on domain decomposition technique using MPI-II message passing library. The computations were carried out using a home made Windows based PC cluster having 160 AMD AthloxXP and Athlon64 processor. The computational domain consisted of through a roundshaped tube with wall conditions. As an initial condition, analytical ZND solution was distributed over the computational domain with disturbances. The disturbances has circumferential large gradient. The unsteady computational results in three-dimension show the detailed mechanisms of multi-cell mode of detonation wave instabilities resulting diamond shape in smoked-foil record.

• 농촌지도와개발
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• 제30권1호
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• pp.43-52
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• 2023

This study aims to examine the effects of GDP as a proxy variable of income, consumer price index as a proxy variable of price, and foot-and-mouth disease and avian influenza as derby variables on rural tourism demand. The independent variables in this research were gross domestic product(GDP), consumer price index(CPI), and dummy variable(DM) such as food & mouth disease & highly pathogenic avian influenza. Results showed that GDP affected tourism demand positively whereas DM influenced negatively. The study suggested that it was important for policy-mconsider GDP and DM when making decision on strategic tourism management. In conclusion, first, gross domestic product was found to have a statistically significant effect on rural tourism demand. Second, avian influenza was found to have a statistically negative effect on rural tourism demand. The results of this study can be used to establish a reasonable rural tourism policy in the future economic dimension.

• 한국의류산업학회지
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• 제11권5호
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• pp.741-752
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• 2009

As a major obstacle to active online purchase at the level of consumer in China, distrust is raised in this study. Most of previous studies showed that trust is a major variable to cause a relational unity between company and consumer, on the other hand, this study attempts to show that according to the two dimensional point of view regarding trust each dimension of both trust and distrust distinctly contributes to marketing achievement. Interaction, perceived popularity, information usefulness, perceived security risk and perceived dealing risk were created as preceding variable, trust and distrust were constituted as parameter and relation absorption and purchase intention as consequential variable. These variables were analyzed with structural equation modeling (SEM) in LISREL 8.3 program. The results for this study are as follows. First, relation between exchange actors in marketing is divided into two concepts of trust and distrust differently from the previous studies. On the assumption that trust and distrust might exist simultaneously and they would distinctly have an influence on marketing consequency such as relation absorption and repurchase intention, it is identified that trust and distrust are a different dimension in online context. Second, the formative factor of online trust-distrust is identified and it is shown what relationship between internet shopping mall and relation absorption and foregoing purchase intention resulting from online trust-distrust exists. Third, it is shown that in online context the formative factor of online trust-distrust is distinctly contributed to relation absorption and repurchase intention. It is suggested that trust needs to be managed two-dimensionally separating from trust and distrust. Fourth, it is shown that both trust and distrust factor in terms of relation absorption and repurchase intention of consumer in internet shopping mall are significant variables. Trust is linked with repurchase intention through relation absorption, however, distrust is not directly linked with repurchase intention through relation absorption. Thus, the ripple effect of distrust appears to be much higher than that of trust.

• 비파괴검사학회지
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• 제25권2호
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• pp.74-80
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• 2005

물체의 형상검사를 위한 검사 방법 가운데 광삼각법을 이용한 레이저 삼각검사 방식은 원격 비접촉식의 고정밀, 고속 측정이 가능하다는 장점이 있다. 이러한 레이저 삼각측정 방식은 평면뿐만 아니라 경사면에 위치한 홀의 길이를 측정하는데 이용하고 있다. 그러나 기존의 방식으로는 렌즈의 초점 거리가 정해져 있었으므로 한정된 영역만을 측정할 수 있다는 단점이 있었다. 이러한 문제는 CCD 카메라와 측정 대상체 사이의 거리를 변화시키는 간단한 방법으로 해결할 수 있다. 이를 원리로 좀더 효율적인 방식을 채택한 것이 가변적인 초점 거리를 갖는 줌 렌즈를 사용하는 방법이다 주 논문에서는 가변적인 초점 거리를 갖는 줌렌즈를 사용함으로써 측정 물체의 크기에 따라 렌즈 배율을 최적화하여 개선된 분해능을 갖는 형상측정 시스템을 제안하였고 정밀도의 향상을 실험적으로 실증하였다.

• 한국소음진동공학회논문집
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• 제23권2호
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• pp.185-191
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• 2013

This paper presents a new method for roller design of IRB(isolation roller bearing) seismic isolation device using experimental evaluation. Three layered plate is adopted for the IRB in which the upper plate is placed on x direction and the lower plate is placed on y direction. The rollers placed in each plate make a plate movement. The roller is then optimally designed using variable geometric conditions. Stress distribution depends on the diameter and length of the roller and hence this is used for the determination of optimal geometry of the roller. In the experimental evaluation, it is observed that stress concentration at the end sides of roller is decreased and geometric coefficients depend on crowning dimension. In addition, in order to determine optimal design parameters of the roller the plastic deformation and friction are experimentally identified.

• Structural Engineering and Mechanics
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• 제25권5호
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• pp.565-576
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• 2007

The article describes a technique for the measurement of the level of complexity of fracture surfaces by the method of vertical sections, and a performed statistical analysis of the effect of profile lines on the fractographic and fractal parameters of fractures, i.e. the profile line development factor, $R_L$, and the fracture surface development factor, $R_S$, (as defined by the cycloid method), as well as the fractal dimension, $D_C$, (as determined by the chord method), and the fractal dimension, $D_{BC}$, (as determined by the box method). The above-mentioned parameters were determined for fracture surfaces of basalt and gravel concretes, respectively, which had previously been subjected to fracture toughness tests. The concretes were made from mixtures of a water/cement ratio ranging from 0.41 to 0.61 and with a variable fraction of coarse aggregate to fine aggregate, $C_{agg.}/F_{agg.}$, in the range from 1.5 to 3.5. Basalt and gravel aggregate of a fraction to maximum 16 mm were used to the tests. Based on the performed analysis it has been established that the necessary number of concrete fracture profile lines, which assures the reliability of obtained testing results, should amount to 12.

• 대한지역사회영양학회지
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• 제11권3호
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• pp.383-391
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• 2006

The purposes of this study were to examine the impacts of characteristics of bakery cafe customers and service quality on customer perceived value, customer satisfaction, intention to revisit, and intention to recommend, and to provide comprehensive understanding on attitudes and behaviors of bakery cafe customers. The questionnaire was developed through literature review and focus group interviews and was modified after pilot test. The questionnaires for the main survey were distributed to 320 males and females aged 20 and over in Seoul. A total of 275 questionnaires were used for analyses (85.9%) and the statistical analyses were completed using SPSS Win (12.0) for descriptive analyses, regression analyses, and correlation analysis. The main results were as follows. There were significant differences of intention to revisit between groups of different gender, age, and personal expenses. The service quality of product dimension affected all tested variables, and the service quality of services and price dimension had effects on customer perceived value and intention to recommend. Customer satisfaction was a unique variable that is affected by service quality of the interior environments dimension. Overall, researchers and managers of bakery cafes should understand customer attitudes and behaviors, and the results of this study would help to establish marketing strategies that meet target customers' needs.