• Journal of Positioning, Navigation, and Timing
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• v.2 no.1
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• pp.49-57
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• 2013

When pseudolite navigation system is applied to wide area, the tropospheric delay is the main error factor. In this study, we experimentally compared and analyzed the performance of the conventional pseudolite tropospheric delay models. The integration method using radiosonde meteorological data was suggested to derive the reference value for the comparison and analysis. Flight tests were carried out to analyze the performance of the tropospheric delay models according to the elevation angle and distance conditions between the user receiver and the pseudolite. As the results of this study, we provided the basis for the choice of tropospheric delay model appropriate to the relative location characteristics of the pseudolite and the user.

• Clinical and Experimental Pediatrics
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• v.57 no.5
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• pp.245-249
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• 2014

Gastrointestinal (GI) hemangiomas are relatively rare benign vascular tumors. The choice of an appropriate diagnostic method depends on patient age, anatomic location, and presenting symptoms. However, GI hemangiomas are not a common suspected cause of GI bleeding in children because of their rarity. Based on medical history, laboratory results, and imaging study findings, the patient could be treated with either medication or surgery. Herein, we report 3 cases of GI hemangioma found in the small bowel, rectum, and GI tract (multiple hemangiomas). Better knowledge and understanding of GI hemangioma could help reduce the delayed diagnosis rate and prevent inappropriate management. Although rare, GI hemangiomas should be considered in the differential diagnosis of GI bleeding.

• Journal of Korean Society of Transportation
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• v.13 no.2
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• pp.5-18
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• 1995

The aims of this study is to analyzed determinants of work-trip satisfaction degrees in six major metropolitan areas. and to derive urban policy implications. As is well -known, the main determinant of travel satisfaction degree is travel time. However, other factors such as travel mode, psychological factor, and priority in residential location choice are also significant ones. The findings imply that transportation problems are deeply related with housing problems in urban areas. This results provides an evidence of the nature of urban problems, i.e. inter-connectiveness among urban problems. Therefore, this study emphasizes that all urban problems should be treated with careful consideration of other related-urban problems.

• The Korean Journal of Applied Statistics
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• v.9 no.2
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• pp.1-11
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• 1996

As an estimate of a location parameter for a given data set, $\alpha$-trimmed mean has been studied for a long time by many statisticians because of its nice propoerties including robustness. However, its performance depends on the proportion of trimming say $\alpha$. In this paper, we suggest a data-driven choice of $\alpha$ and study its validity. Also, we suggest a new estimator and consider double-bootstrap to improve its performance. By using simulation study, the proposed method is compared with the exiting one in various cases. Real data sets are also analyzed by using the proposed method.

• Culinary science and hospitality research
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• v.6 no.2
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• pp.157-173
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• 2000

The purpose of this study is to identify important selection attributes for customers dining at family restaurants in Seoul, and the determinant and predicting factors in customers' intentions to return. A closed-ended questionnaire was used, and a systematic sampling approach was employed to survey a sample of customers in family restaurants. The data were analyzed using factor and multiple regression analysis. A four-dimensional structure was established from 14 selection attributes. The results of the study indicated four dimensions that were significantly related to the likelihood of customers returning to the same restaurants, as follows: Food and Environment, Service and Courtesy, Price and value, and Location and promotion. The findings from this study have both theoretical and practical implications. Implications of these findings are discussed.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.11
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• pp.1712-1720
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• 1989

We propose a new radiating structure composed of a strip and a slot excited by an ideal current source, and electromagnetic analysis for the structure is presented. By the analysis procedure which is based upon equivalence formulated. Through the numerical computations to solve the equations by employing the method of moments, we ascertained that the suitable choice of the location and the size of strip guarantee the improvement of the radiation characteristics of antenna.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.818-823
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• 2006

In this study, the suitability of CFGD(concrete faced gravefill dam) was investigated by examining the strength and deformation characteristics of a gravelfill material, a CFGD main fill material, and comparing them with those of several rockfill dam materials. The gravelfill material exhibited similar strength and deformation properties to those of the main fill materials of existing stable large rockfill dams. Since not only CFGD has environmental and economic advantages over CFRD, but its main fill material compares favorably with those of the existing stable CFRDs, CFGD may be the best choice when natural gravel materials are abundant in the vicinity of the dam construction location.

• Culinary science and hospitality research
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• v.14 no.4
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• pp.456-468
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• 2008

This paper analyzes how the service quality affects customer satisfaction and loyalty, focusing on a franchise restaurant company 'Wonhalmoney Bossam'. The result shows that store locations and food cost of the menu, as an additional quality formation factor, influence customer satisfaction and loyalty rather than the main quality formation factors. This study strongly suggests the marketing preparation of menu price and the choice of locations are most significant as an additional factor. Therefore, Korean food restaurants should develop their marketing strategies from the customer's point of view, and reasonable price setting and menu selection with appropriate location will create customer satisfaction and revisit.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.7
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• pp.814-819
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• 2016

The Stockbridge damper is used to control the aeolian vibration of a overhead transmission line due to the natural wind under a low velocity, between 1 m/s to 7 m/s. The damper model can be simply derived with several design parameters and the location of eigenvalues of design parameters are important to determine the efficiency of energy dissipation by excitation itself with two counterweights. First, the importance of resonance frequencies of Stockbridge damper was reviewed through the analysis of frequency response function of damper system. Then, the best selection of design parameters was investigated with the introduction of objected function that minimize the distance between the calculated eigenvalues and target frequency points. The best choice of design parameters was reviewed using the simulated results from the objective function and the effectiveness of selected design case was discussed at the point view of practical implementation.

• Journal of Mechanical Science and Technology
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• v.15 no.8
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• pp.1119-1131
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• 2001

In this paper we formulate an optimization based approach to determining the maximally inscribed rectangle in a robots workspace. The size and location of the maximally inscribed rectangle is an effective index for evaluating the size and quality of a robots workspace. Such information is useful for, e. g., optimal worktable placement, and the placement of cooperating robots. For general robot workspaces we show how the problem can be formulated as a constrained nonlinear optimization problem possessing a special structure, to which standard numerical algorithms can be applied. Key to the rapid convergence of these algorithms is the choice of a starting point; in this paper we develop an efficient computational geometric algorithm for rapidly obtaining an approximate solution suitable as an initial starting point. We also develop an improved version of the algorithm of Haug et al. for calculating a robots workspace boundary.