• Journal of Korean Society of Transportation
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• v.14 no.3
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• pp.75-90
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• 1996

The objective of study is to examine relationship between traffic flow characteristics of two lane entrance terminal and acceleration length, and to suggest the acceleration length by level of service. The relationship between the speed ratio and the distance from the ramp appeared to be a quadratic concave from. In the case of two lane entrance ramp, the acceleration length is suggested as 1.4~2.0 times longer than the acceleration length of one lane entrance ramp. It is also recommended that acceleration length for two lane entrance ramp should be designed according to the level of service at the right most lane (level of service A : 1.4 B : 1.6 C : 1.8 D : 2.0 times of the one lane entrance ramp acceleration length) on freeway.

• Korean Journal of Digital Imaging in Medicine
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• v.12 no.1
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• pp.59-64
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• 2010

We examined the accuracy and efficiency of phantom by applying the designed phantom in order to check daily quality assurance easily by objective criteria and to confirm daily quality assurance of linear accelerator, simulator, and CT-simulator. The results of 10 weeks of linear accelerator output dose using American Association of Physicists in Medicine(AAPM) daily quality assurance guide were measured within ${\pm}1%$ of error. Mechanical check of laser alignment, optical distance indicator(ODI), CT scanner laser and alignment of gantry lasers with the center of imaging plane were measured within ${\pm}1mm$. Daily average working time for daily quality assurance of radiation therapy equipments was 38 minutes. The designed phantom was easy to install and daily quality assurance was possible with only one installation. The aspects reproducibility and efficiency as well as accuracy of quality assurance were excellent.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.12
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• pp.109-118
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• 1999

The objective of this research is to develop an effective inspection planning strategy for sculpture surfaces in OMM(On-Machine Measurement) process. As a first step, effective measuring point locations are determined to obtain optimum results for given sampling numbers. Two measuring point selection methods are suggested in this study based on newly proposed CAD/CAM/CAI integration concept: (1) by the prediction of cutting errors, (2) by considering cutter contact points to avoid the measurement errors caused by cusps. As a next step, the TSP(Traveling Salesman Problem)algorithm is applied to minimize the probe moving distance. Appropriate simulations and experiments are performed to verify the proposed inspection planning strategy in this study, and the results are analyzed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.379-382
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• 2004

Abrasive jet machining (AJM) has a large number of parameters such as powder flow rate, air pressure, diameter of abrasive, stand off distance, material hardness and fracture toughness, etc. It is not easy matter to control those parameter. To achieve high accurate machining, in this study, Taguchi method was used to select process parameters. The objective of the optimization was to get higher material removal rate (MRR). From the experiments and analysis, some process parameters were found to make efficient machining.

• IE interfaces
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• v.9 no.2
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• pp.203-218
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• 1996

This paper deals with a Direct-Input-Output Manufacturing System (DIOMS) which has a number of machine centers placed along a built-in automated storage/retrieval system (AS/RS). During its operations, the storage/retrieval(S/R) machine picks up a pallet from the pickup/deposit port of a machine center and then moves it either to an empty rack opening of the AS/RS for temporary storage or to place it on the port of another machine center for subsequent operation. The machine layout problem in DIOMS is formulated as an integer mathematical programming whose objective is to minimize the total expected distance of the loaded S/R machine during a production period. Recognizing the limit of the exact solution procedure(the Branch and Bound method), two improvement-type heuristics are proposed. One is based on the simulated annealing method and the other the pairwise interchange method. The validity of the heuristics is examined with example problems.

• Journal of Korea Multimedia Society
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• v.17 no.2
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• pp.113-123
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• 2014

Electrophysiological recordings are considered a reliable method of assessing a person's alertness. Sleep medicine is asked to offer objective methods to measure daytime alertness, tiredness and sleepiness. As EEG signals are non-stationary, the conventional method of frequency analysis is not highly successful in recognition of alertness level. In this paper, EEG signals have been analyzed using wavelet transform as well as discrete wavelet transform and classification using statistical classifiers such as euclidean and mahalanobis distance classifiers and a promising method SVM (Support Vector Machine). As a result of simulation, the average values of accuracies for the Linear Discriminant Analysis (LDA)-Quadratic, k-Nearest Neighbors (k-NN)-Euclidean, and Linear SVM were 48%, 34.2%, and 86%, respectively. The experimental results show that SVM classification method offer the better performance for reliable classification of the EEG signal in comparison with the other classification methods.

• Journal of Plant Biotechnology
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• v.7 no.2
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• pp.113-121
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• 2005

The objective of this study was to identify the major parameters controlling DNA delivery by particle bombardment to immature embryos of Chinese spring wheat (Triticum aestivum L.). Efficiency of DNA (uidA gene) delivery was assessed by transient GUS (${\beta}$-glucuronidase) expression in bombarded tissues. Of the parameters analyzed, acceleration pressure, bombardment distance, chamber vacuum pressure, bombardment times, osmotic conditioning of culture had a remarkable influence on transient gene expression. A bombardment procedure suitable for Chinese spring wheat cultivars was developed which allowed high-efficiency DNA delivery combined with reduced damage to target tissues. The high efficiency made the system practical for wheat genetic transformation research and accelerating wheat breeding programs.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.534-535
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• 2009

The objective of this research aims preliminary assessments of the proposed plans of offshore wind farm development based on the recently established national offshore wind map and suitability assessment system of offshore wind farm. Incheon Mueodo, Busan Dadaepo-Gadukdo, Sinangun Haeodo have been assessed considering geographic constraints such as water depth, offshore distance, national park, grid connection, and meteorological constraint such as wind power density and wind direction. According to the assessment, Mueodo plan has a weak point in grid connection and several geographic limitations are involved in Haeodo plan while Dadaepo-Gadukdo seems the most possible plan among the review cases. Because of limited assessment in this research, more detail and further consideration are necessary to make a decision of a feasibility project at proposed sites.

• Management Science and Financial Engineering
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• v.3 no.1
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• pp.1-14
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• 1997

We address the problem of determining the sequence of a vehicle with fixed capacity to visit n nodes at which a predetermined amount is picked up and/or delivered. The objective is to minimize the total travel distance of the vehicle, while satisfying the pick-up/delivery requirements and feasibility at all nodes. Existing methods for the problem allows the vehicle to visit a node twice, which is impractical in many real situations. We propose a heuristic algorithm, in which every node is visited exactly once. Computational results using random problems indicate that the proposed heuristic outperforms existing methods for practical range of the number of nodes in reasonable computation time.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.5
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• pp.1-7
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• 2011

The objective of this study is to decide a spatial interpolation method on temperature data for the suitability analysis of garlic cultivation. In Korea, garlic is the second most cultivated condiment vegetable after red pepper. Nowadays warm-temperate garlic faces potential shift of its arable area according to warmer temperature in the Korean Peninsula, and the change can be drawn with the precise temperature map derived from interpolation on point-measured data. To find the preferable interpolation method in cases of germination and vegetative period of the garlic, different approaches were tested as follows: Inverse Distance Weighted (IDW), Spline, Ordinary Kriging (OK), and Universal Kriging (UK). As a result, IDW and UK show the lowest root mean square errors as for the germination and vegetative seasons, respectively. However, statistically significant difference was not revealed among the applied methods regarding the germinating period. Eventually this will contribute to mapping the suitable lands for the cultivation of warm-temperate garlic reasonably.