• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.2
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• pp.47-58
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• 2013

The purpose of this study is to categorize the types of sidewalk cafes, and to evaluate design factors with types of sidewalk cafes for street revitalization. Consequently, it may suggest efficient and systemic policies for the guidelines of sidewalk cafes. To ensure this end, the types of sidewalk cafes were categorized from the street relationship perspective by site investigation. A literature review and importance analysis were used to select the evaluation criteria, and the data were analyzed by statistic methods such as descriptive analysis and factor analysis. As a result, five main factors of the evaluation criteria were contracted: accessibility, aesthetics, identity, environmental, culturedness. Cumulative factor loading of these five factors was 68.731%, which was quite high. And the evaluation using the Likert scale was performed by 4 experts. Types of sidewalk cafes were categorized into 5 types: protruding, gating, blending stereoscopic, elevation angle, and sign provision from the street relationship perspective. On the evaluation by type, aesthetics and culturedness were the worst evaluated in the protruding type and the gating type, culturedness was the worst in the blending stereoscopic type, accessibility, aesthetics, culturedness were the worst in the elevation angle type, and accessibility, identity, culturedness were the worst in the sign provision type. On the evaluation by the indicators, culturedness was the worst evaluated, and on the evaluation by criteria, 'safety for impaired persons', 'interest of programs', 'openness of entrance' were the worst. It is recommended that a survey of importance-performance analysis focused on users be conducted.

• Economic and Environmental Geology
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• v.46 no.4
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• pp.313-327
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• 2013

In the study, three-dimensional geostatistical simulations on McMurray Formation which is the largest oil sand reservoir in Athabasca area, Canada were performed, and the optimal site for steam assisted gravity drainage (SAGD) was selected based on the predictions. In the selection, the factors related to the vertical extendibility of steam chamber were considered as the criteria for an optimal site. For the predictions, 110 borehole data acquired from the study area were analyzed in the Markovian transition probability (TP) framework and three-dimensional distributions of the composing media were predicted stochastically through an existing TP based geostatistical model. The potential of a specific medium at a position within the prediction domain was estimated from the ensemble probability based on the multiple realizations. From the ensemble map, the cumulative thickness of the permeable media (i.e. Breccia and Sand) was analyzed and the locations with the highest potential for SAGD applications were delineated. As a supportive criterion for an optimal SAGD site, mean vertical extension of a unit permeable media was also delineated through transition rate based computations. The mean vertical extension of a permeable media show rough agreement with the cumulative thickness in their general distribution. However, the distributions show distinctive disagreement at a few locations where the cumulative thickness was higher due to highly alternating juxtaposition of the permeable and the less permeable media. This observation implies that the cumulative thickness alone may not be a sufficient criterion for an optimal SAGD site and the mean vertical extension of the permeable media needs to be jointly considered for the sound selections.

• Journal of Periodontal and Implant Science
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• v.38 no.4
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• pp.611-620
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• 2008

Purpose: The purpose of this study was to assess the long term survival rates of the most posterior single tooth implant and to evaluate the influence of implant characteristics on implant survival. Material and Methods: This retrospective report presents findings on 37 patients with 43 implants replacing single molars. The inclusion criteria were having implants replacing a molar of the most posterior region and follow-up data over at least 6 months. Data were recorded regarding the incidence of complications and survival rates of these implants. Results: The range of follow-up was from 9 to 66 months(mean: 40.2 months). The cumulative survival rate of total implants was 93.0% which reflects the loss of three implants: one had broken neck, one implant failed because of infection, one implant showed failed osseointegration. Abutment- screws loosening occurred in five implants(11.6%). Conclusion: Within the limits of this study, a single tooth-implant can serve as a good long-term and predictable treatment modality to replace the most posterior teeth with low complication and failure rates.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.61.2-61.2
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• 2013

We present a study of optically emitting supernova remnants (SNRs) in M31 based on $H{\alpha}$ and [S II] images in the Local Group Survey. Using these images, we have selected objects that have [S II]:$H{\alpha}$ > 0.4 and morphology for typical SNRs. We find 76 new SNRs. We have also inspected 233 SNR candidates presented in previous studies, confirming that only 80 of them are SNRs. Combining these, we produce a master catalog of 156 SNRs in M31. We classify these SNRs according to two types of criteria: the SNR progenitor types (Type Ia and core-collapse (CC) SNRs) and the morphological types. Type Ia and CC SNRs are 23% and 77%, respectively, of the total sample. Most of CC SNRs are concentrated along the spiral arms, while Type Ia SNRs are rather spread over the entire galaxy including the inner region. CC SNRs are brighter in $H{\alpha}$ and [S II] than Type Ia SNRs. The cumulative size distribution of the SNRs with 15 < D < 50 pc is well fitted by a power law with an index, ${\alpha}=2.53{\pm}04$. It indicates that most SNRs in M31 are in Sedov-Taylor phase. Properties of these SNRs show little variation depending on the galactocentric distance. The $H{\alpha}$ and [S II] surface brightness shows a good correlation with X-ray luminosity for the SNRs that are center-bright.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.581-584
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• 2005

A district heating(DH) system supplies environmentally-friend heat and is appropriate for reduction of energy consumption and/or air pollutions. The objectives of this paper are to systematize data processing of transition temperature, investigate its effects on fatigue life of DH pipes and optimization for size of DH pipes. A relational database management system as well as reliable fatigue life evaluation procedures is established for Korean DH pipes. Also, since the prototypal evaluation results satisfied both cycle-based and stress-based fatigue criteria. Through the optimum design process, the cross section diminished 18.64% and the CUF diminished 23.35%. So, it can be used as useful information in the future for optimal design, operation and energy saving via setting of efficient condition and stabilization of water temperature.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1682-1685
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• 2005

System algorithms estimated by deterministic input may occur the error between predicted and actual output. Especially, actual system can't predict the exact outputs due to uncertainty and tolerance of input parameters. A single output to a set of inputs has a limited value without the variation. Hence, we should consider various scatters caused by the load assessment, material characteristics, stress analysis and manufacturing methods in order to perform the robust design or estimate the reliability of structure. The system design with uncertainty should perform the probabilistic structural optimization with the statistical response and the reliability. This method calculated the probability distributions of the characteristics such as stress by combining stress analysis, response surface methodology and Monte-Carlo Method and got the probabilistic sensitivity. The sensitivity of structural response with respect to inconstant design variables was estimated by fracture probability. Therefore, this paper proposed the probabilistic reliability design method for fracture of uncorved freight end beam and the design criteria by fracture probability.

• Journal of Korean Institute of Industrial Engineers
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• v.41 no.3
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• pp.287-295
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• 2015

Due to the latest agreement between the military authorities of the Republic of Korea (ROK) and the United States (US) of America, Korea's annual contribution to the budget of the United States Forces Korea (USFK) rose as high as close to 1 trillion won. This seemingly prohibitive amount has led to the questioning of military critics regarding determination criteria, wholesomeness of cost, alignment of incentives, and implementational transparency, etc. As these sources of mistrust can potentially undermine the congruence of alliance, we attempt to devise a scientific means to test the validity of Korea's budget contribution. Specifically, we use the real options approach (ROA) to estimating the interval of the fair prices of maintaining the USFK. We consider the USFK as an insurance against foreign incursions, and this enables us to assume their role as a put option. Upon a hypothetical war breakout, the daily cumulative size of the Korean economy is estimated by implementing the simulated loss ratios of assets and population. As a result, the strategic value (put premium) of the USFK is exponentially higher the sooner the US forces are augmented following an intrusion. Also, Korea's payments toward the USFK in 2011 and 2012 appear theoretically fairly valued.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.3
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• pp.183-189
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• 2013

In this paper, uncertainties and failure criteria of structure are mathematically expressed by random variables and a limit state equation. A limit state equation is approximated by Fleishman's 3rd order polynomials and the theoretical moments of an approximated limit state equation are calculated. Fleishman introduced a 3rd order polynomial in terms of only standard normal distiribution random variables. But, in this paper, Fleishman's polynomial is extended to various random variables including beta, gamma, uniform distributions. Cumulants and a normalized limit state equation are used to calculate a theoretical moments of a limit state equation. A cumulative distribution function of a normalized limit state equation is approximated by a Pearson system.

• Journal of the Korean Institute of Gas
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• v.10 no.1 s.30
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• pp.48-55
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• 2006

In order to establish the comprehensively, quantitatively predictable program to the fire and explosion accidents in the urban gas system, and to set up domestic criteria of societal risk, the collected urban gas accident data have been deeply analyzed. The Poisson probability distribution functions with t=5 for the database of the gas accidents in recent 11 year shows that 'careless work-explosion-pipeline' item has the lowest frequency, whereas 'joint loosening & erosion-release-pipeline' item has the highest frequency. And thus the proper counteractions must be carried out. The further works requires setting up successive database on the fire and explosion accidents systematically to obtain reliable analyses.

• Transactions of The Korea Fluid Power Systems Society
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• v.8 no.3
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• pp.1-7
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• 2011

As the technologies of electronic device have advanced these days, most of mechanical systems are designed with electronic control unit to take advantage of control parameter adaption to operating conditions and firmware flexibilities as well. On-board diagnosis, which detects the system malfunction and identifies potential source of error with its own diagnostic criteria, and fail-safe that can switch the mode of operation in view of recognized error characteristics enables easy maintenance and troubleshooting as well as system protection. This paper dealt with the development of diagnosis and fail-safe function for proportional flow control valve. All type of errors related to valve control system components are investigated and assigned to a specific hexadecimal codes. Cumulative error detection algorithm is applied in order for the sensitivity and reliability to be appropriate. Embedded simulator which runs simultaneously with system program provides the virtual error simulation environment for expeditious development of error detection algorithm. The diagnosis function was verified both with solenoid valve and embedded simulator test and it will enhance the valve control system monitoring function.