• Korean Journal of Remote Sensing
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• v.34 no.6_3
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• pp.1427-1443
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• 2018

Object-based image analysis (OBIA) allows higher computation efficiency and usability of information inherent in the image, as it reduces the complexity of the image while maintaining the image properties. Superpixel methods oversegment the image with a smaller image unit than an ordinary object segment and well preserve the edges of the image. SLIC (Simple linear iterative clustering) is known for outperforming the previous superpixel methods with high image segmentation quality. Although the input parameter for SLIC, number of superpixels has considerable influence on image segmentation results, impact analysis for SLIC parameter has not been investigated enough. In this study, we performed optimal parameter analysis and evaluation of change detection for SLIC-based superpixel techniques using KOMPSAT data. Forsuperpixel generation, three superpixel methods (SLIC; SLIC0, zero parameter version of SLIC; SNIC, simple non-iterative clustering) were used with superpixel sizes in ranges of $5{\times}5$ (pixels) to $50{\times}50$ (pixels). Then, the image segmentation results were analyzed for how well they preserve the edges of the change detection reference data. Based on the optimal parameter analysis, image segmentation boundaries were obtained from difference image of the bi-temporal images. Then, DBSCAN (Density-based spatial clustering of applications with noise) was applied to cluster the superpixels to a certain size of objects for change detection. The changes of features were detected for each superpixel and compared with reference data for evaluation. From the change detection results, it proved that better change detection can be achieved even with bigger superpixel size if the superpixels were generated with high regularity of size and shape.

• The Korean Journal of Archival Studies
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• no.37
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• pp.273-305
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• 2013

In order to actively use of records and information in current digital record management systems, we have to check whether a system is designed to fully support the user of records and whether the good use of the system is being. This study analyzed the status of the use of the search function of Records Management System(RMS) for public agencies, and evaluated them. In order to investigate the status of the use of the search function, it surveyed records managers of public agencies using the RMS. The result showed that records managers unsatisfied with the usability and the search performance of the RMS. To evaluate the search function, it identified the functional requirement of the system and develops a checklist that can be used for evaluation. Two assessments were conducted. Firstly, as pre-evaluation, it assessed the degree of implementation of the current RMS according to the checklist as an inspection chart using document examination method. Secondly, it assessed the degree of implementation using a survey of records managers of public agencies that use the RMS. Assessment results show the improvement of the basic features that are essential to the system is required. In particular, the search function is required to improve user-friendliness for the user. For the advance of RMS, this study discusses the necessity for improvement of the search functions, the build of continuous maintenance and management system, and the user education.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.1
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• pp.55-63
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• 2021

The roughness of the road is an important factor directly connected to the ride comfort, and is an evaluation item for functional evaluation and pavement quality management of the road. In this study, data on the road surface were acquired using the latest 3D geospatial information construction technology of ground LiDAR, drone photogrammetry, and drone LiDAR, and the accuracy and roughness of each method were analyzed. As a result of the accuracy evaluation, the average accuracy of terrestrial LiDAR were 0.039m, 0.042m, 0.039m RMSE in X, Y, Z direction, and drone photogrammetry and drone LiDAR represent 0.072~0.076m, 0.060~0.068m RMSE, respectively. In addition, for the roughness analysis, the longitudinal and lateral slopes of the target section were extracted from the 3D geospatial information constructed by each method, and the design values were compared. As a result of roughness analysis, the ground LiDAR showed the same slope as the design value, and the drone photogrammetry and drone LiDAR showed a slight difference from the design value. Research is needed to improve the accuracy of drone photogrammetry and drone LiDAR in measurement fields such as road roughness analysis. If the usability through improved accuracy can be presented in the future, the time required for acquisition can be greatly reduced by utilizing drone photogrammetry and drone LiDAR, so it will be possible to improve related work efficiency.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.2
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• pp.67-79
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• 2023

The bounce rate is the rate at which a user leaves immediately after visiting, and this study aimed to find out what attributes of a website affect the bounce rate. Web site evaluation items were defined as a total of 4 items and 27 evaluation attributes, including usability, information, service interaction, and technology, so that they can be commonly applied to venture companies in various industries through prior research. As a result of the study, 6 website attributes that affect the bounce rate were verified to be significant by discriminant analysis and decision tree analysis. Suggestions to reduce the bounce rate of venture business websites through this study are as follows. First, the path name of the website is displayed as mandatory and a pull-down menu function is added to facilitate movement to other pages. Second, it is good to expose core content that can attract users' attention in the form of a banner, and place internal link banners in the right place on sub-pages. Third, external links should be linked to a new window so that they do not leave the current page immediately so that they can be re-entered. Lastly, it is recommended to expose the contact information of the person in charge and consultation function as direct information for communication with customers, but if individual response is difficult, at least the consultation function must be added. These suggestions are expected to be of practical help in various fields such as website development, operation, and marketing. However, in special cases, a high bounce rate may be normal, so it should be considered according to the situation.

• The Journal of Korean Society for Radiation Therapy
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• v.28 no.1
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• pp.77-86
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• 2016

Purpose : When a radiation treatment, there is an attenuation by Carbon Fiber Couch. In this study, we tried to evaluate the usability of the Varian Standard Couch(VSC) by modeling with Treatment Planning System (TPS) Materials and Methods : VSC was scanned by CBCT(Cone Beam Computed Tomography) of the Linac(Clinac IX, VARIAN, USA), following the three conditions of VSC, Side Rail OutGrid(SROG), Side Rail InGrid(SRIG), Side Rail In OutSpine Down Bar(SRIOS). After scan, the data was transferred to TPS and modeled by contouring Side Rail, Side Bar Upper, Side Bar Lower, Spine Down Bar automatically. We scanned the Cheese Phantom(Middelton, USA) using Computed Tomography(Light Speed RT 16, GE, USA) and transfer the data to TPS, and apply VSC modeled previously with TPS to it. Dose was measured at the isocenter of Ion Chamber(A1SL, Standard imaging, USA) in Cheese Phantom using 4 and 10 MV radiation for every $5^{\circ}$ gantry angle in a different filed size($3{\times}3cm^2$, $10{\times}10cm^2$) without any change of MU(=100), and then we compared the calculated dose and measured dose. Also we included dose at the $127^{\circ}$ in SRIG to compare the attenuation by Side Bar Upper. Results : The density of VSC by CBCT in TPS was $0.9g/cm^3$, and in the case of Spine Down Bar, it was $0.7g/cm^3$. The radiation was attenuated by 17.49%, 16.49%, 8.54%, and 7.59% at the Side Rail, Side Bar Upper, Side Bar Lower, and Spine Down Bar. For the accuracy of modeling, calculated dose and measured dose were compared. The average error was 1.13% and the maximum error was 1.98% at the $170^{\circ}beam$ crossing the Spine Down Bar. Conclusion : To evaluate the usability for the VSC modeled by TPS, the maximum error was 1.98% as a result of compassion between calculated dose and measured dose. We found out that VSC modeling helped expect the dose, so we think that it will be helpful for the more accurate treatment.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.5
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• pp.74-86
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• 2015

The purpose of this study was to deduce the landscape evaluation indices that can be applied from the preparation for the registration of major national farm/fishery heritages to post-management. For this purpose, the Delphi survey was performed on experts. From August to November in 2014, the primary open survey, secondary open survey, and tertiary closed survey were performed to gather opinions from 28 experts, 25 experts, and 29 experts, respectively. As a result, the landscape evaluation indices for farm/fishery heritage consisted of five areas of evaluation, ten items of evaluation, and 40 indices of evaluation. The areas of evaluation were rurality, authenticity, aesthetics, tourism potentials, and locality. Rurality was classified into rurality of farm/fishery towns and nostalgia. Authenticity was classified into objective authenticity and existential authenticity. Aesthetics was classified into attractiveness and harmony. Tourism potentials were classified into value of resources and value of usability. Locality was divided into physical originality and cultural identity. The study made the following findings: first, the general grounds of farm/fishery landscape evaluation cannot be applied when evaluating the quality of landscapes of farm/fishery heritage, as their value as a cultural heritage should be considered. Second, the new indices valued emotional factors in addition to the physical factors considered by the existing farm/fishery landscapes. The new indices involved a more expanded concept of landscapes as it also considers everyday or temporary activities, including the farm/fishery activities of local people or participation in festivals and experience programs. Third, farm/fishery heritage focuses on the lives of local people, as it involves both the synchronic and the diachronic perspectives to see what is currently visible and what is no longer visible. This brings into consideration not only the farms and the natural environments but also their relationships with the villages, especially the residential areas. Finally, the indices reflected both the farm/fishery heritage's value as cultural heritage and its value for tourism. They derived temporary and dynamic landscapes, including the trading activities of local specialty markets in relation to the production landscapes. However, further studies should be conducted as this study could not rate the relative importance of indices or compare the total scores of landscapes without the weight of each item.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.419-424
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• 2006

본 연구는 데스크탑 PC 환경에서 사용될 수 있는 다양한 적응형 메뉴 인터페이스의 사용성을 평가한다. 선택 빈도에 따라 자동으로 변화하는 2가지 방식의 Adaptive menu와 사용자가 메뉴 내에서 원하는 항목의 위치를 직접 변경하는 Adaptable menu의 사용성을 일반적으로 많이 이용되는 Traditional menu와 비교하기 위해 사용자를 동원한 평가 실험을 수행하였다. Adaptive menu에는 선택 빈도가 높은 메뉴 항목이 메뉴의 상단으로 이동하는 Adaptive split menu와 자주 선택되는 항목이 굵은 글씨로 표현되는 Adaptive style menu가 포함된다. 각 방식의 적응형 메뉴가 자주 선택되는 메뉴 항목의 변화에 따라 얼마나 민감하게 영향을 받는지 비교하기 위해, 두 개의 각기 다른 선택 빈도 분포가 이용되었다. 각 실험 조건 별로 사용자가 메뉴 항목을 선택하는 데 걸린 시간과 오류 회수를 측정하였으며, 피실험자로 하여금 시인성, 효율성, 전반적 선호도 등의 주관적인 만족도를 평가하도록 하였다. 각각의 종속 변수들은 분산 분석(ANOVA), Chi-square test, Friedman test 등의 기법을 이용해 분석되었다. 분석 결과, Adaptable menu가 다른 방식의 메뉴들에 비해 수행도와 만족도 모두 높은 것으로 나타났으며, Adaptive split menu는 상대적으로 현실적인 조건 하에서 큰 효용을 갖지 못하는 것으로 나타났다. Adaptive style menu는 수행도 측면에서는 일반적인 메뉴와 큰 차이가 없었지만, 자주 선택되는 항목을 쉽게 파악할 수 있게 해 주고, 선택 빈도의 변화에도 민감하지 않기 때문에 사용자들에게 선호되는 것으로 나타났다. 본 연구의 결과는 데스크탑 PC의 적응형 메뉴 설계에 대한 이용될 수 있으며, 추후 휴대용 정보기기의 적응형 메뉴에 대한 사용성 연구의 기초 자료로도 활용될 수 있을 것으로 기대된다.

• Journal of the Ergonomics Society of Korea
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• v.36 no.2
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• pp.69-86
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• 2017

Objective: The present study is intended to develop an improved bus seat armrest design by evaluating various bus armrest designs from ergonomic aspects. Background: An ergonomic armrest design which considers the sitting postures and body shapes of passengers can improve the convenience and comfort of a bus seat. Method: Subjective satisfaction of each of five design dimensions (length, width, height from seatpan, shape, and angle) was evaluated for seven bus seat armrest designs in various sizes and shapes by 58 participants (28 males and 33 females) using a 7-point scale (1: very dissatisfied, 4: neutral, and 7: very satisfied). Improved bus seat armrest designs adjustable in length and rotatable to the left or right (sliding and rotating armrest, SRA) with a concave, flat, or convex shape of the upper part were developed by considering the preferred design features and the body size and shape in sitting posture and needs of passengers and then compared with a conventional armrest. Results: A bus seat armrest with a wide width (40~50mm), a long length (360mm), a lower height (213mm), and a curved shape was found significantly preferred in terms of comfort. The proposed armrest designs (SRA-convex, SRA-flat, and SRA-concave) improved satisfaction by 46~62% for length suitability, 184~216% for width suitability, 205~214% for angle suitability, 138~181% for contact area suitability, and 49~64% for height suitability, 138~174% for comfort, and 93~111% for overall satisfaction. Conclusion: The preferred design features and passengers' needs of bus seat armrest were identified and the SRA designs were recommended for better usability. Application: The ergonomic design process of bus seat armrest employed in the present study can be applied to designing armrests in various vehicles for better convenience and comfort.

• Imaging Science in Dentistry
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• v.47 no.2
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• pp.87-92
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• 2017

Purpose: The aim of this study was to determine whether the panoramic mandibular index (PMI) is useful for assessing bone mineral density. We also analyzed the potential correlations between PMI parameters and patient age. Materials and Methods: Four observers measured the PMI of both sides of the mental foramen using a picture archiving and communication system and images in the Digital Imaging and Communications in Medicine format. They studied 300 panoramic radiographic images of patients belonging to the following age groups: 40-49 years, 50-59 years, 60-69 years, 70-79 years, and 80-89 years. The observers were allowed to zoom in or out and to adjust the contrast of the images. Further, they were instructed to record the reasons for any measurements that could not be made. Then, we conducted a reliability analysis of the measured PMI and assessed the correlations between different patient age groups and the 3 parameters used for determining the PMI from the available data. Results: Among the 600 data items collected, 23 items were considered unmeasurable by at least 1 observer for the following 4 reasons: postoperative state, lesion, unidentified mental foramen, and alveolar bone loss. The intraobserver reproducibility of the measurable data was 0.611-0.752. The mandibular cortical width (MCW) decreased significantly as patient age increased. Conclusion: PMI had limited usability when the margin of the mental foramen was not clear. In contrast, MCW, a parameter used for determining the PMI, had fewer drawbacks than the PMI with respect to bone mineral density measurements and exhibited a significant correlation with patient age.

• Journal of Korean Society of Transportation
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• v.32 no.1
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• pp.39-49
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• 2014

The continuing growth of transportation and communication has resulted in the spread of transportation information interlocked with the Internet. General users are actively seeking web-based transportation information and are trying to apply it into their lives. Now the implementation of user-centered transportation information services are becoming the essential activity for pertinent companies or public institutions. In this paper the author tried to measure the quality of web sites featuring transportation information using the robust measurement tool called WebQual. In addition, the author investigated the relationship between the components of WebQual (usability, information quality, and interactivity) and satisfaction/intention to revisit. According to the results, WebQual had the effectiveness of confirming the service quality for the web sites of transportation information. Also the components of WebQual had positive influences on satisfaction and intention to revisit.