• Journal of the Korean Society for Library and Information Science
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• v.53 no.2
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• pp.247-266
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• 2019

The purpose of this study is to propose a W3C standard, DCAT, to manage and service dataset that is becoming increasingly important as new knowledge information resources. To do this, we first analyzed the class and properties of the four core classes of DCAT. In addition, I modeled and presented a system that can manage and service various data sets based on DCAT in digital library. The system is divided into source data, data set management, linked data connection, and user service. Especially, the DCAT mapping function is suggested in dataset management. This feature can ensure interoperability of various datasets.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.6
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• pp.110-116
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• 2021

W3C enacted RDF(Resource Description Framework based DCAT meta data standard, which is world-widely accepted so far. To guarantee the inter-operability and integrity of data from various sources and even from various countries, it is considered that transportation meta data should also follow the DCAT standard. But still, to represent the transportation domain-specific features, it is necessary to define new properties and vocabularies in addition to the DCAT standard. This research identified the additional properties and vocabularies for transportation metadata, considering uniqueness of transportation data. The revised RDF schema and RDF graph proposed in this research should be able to lead the transportation open data platform revitalization.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.491-493
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• 2021

최근 데이터 산업 발전과 함께 데이터를 저장, 공유, 거래가 가능한 다양한 데이터 저장소와 거래소가 증가하고 있다. 대부분의 데이터 저장소 및 거래소는 데이터 검색과 공유를 위해 DCAT 기반 메타데이터를 구성하고 있다. 하지만 DCAT 기반 메타데이터는 웹 검색 엔진에서 검색이 잘되지 않는 문제점을 가지고 있다. 이는 웹에서 자원을 출판하기 위한 데이터 모델 기법이 Schema.org 방법을 사용하고 있기 때문이다. 본 논문에서는 이런 문제점을 해결하기 위해 DCAT 기반 메타데이터를 Schema.org 방법으로 변환할 수 있는 새로운 기법을 제안한다. 제안하는 변환 기법은 데이터 저장소와 거래소 내 데이터셋이 웹에서 잘 검색될 수 있는 웹 출판 기능을 지원한다.

• Journal of Digital Contents Society
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• v.19 no.1
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• pp.59-65
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• 2018

As open data(public data) began to be recognized as a source of national economic development, many countries began to build public data portals and provide open data to the private sector. In accordance with this trend, open source communities have begun to develop open data platform such as CKAN and enable to share dataset among open data platforms by applying metadata standard technology. However, many governments and local governments are still making it difficult to share data between data portals because they build their own platforms. In this paper, we propose a DCAT-based metadata transformation tool to solve these problems, and show how to transform a dataset into DCAT.

• Journal of Korean Library and Information Science Society
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• v.51 no.4
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• pp.249-278
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• 2020

The purpose of this study is to design metadata for management and sharing of Yeogu data produced in the ecological field. Specifically, metadata is designed based on DCAT, which is designed to facilitate interoperability between data catalogs published on the web. In addition, ABCD, Darwin Core, and EML were analyzed and applied to metadata design to reflect the characteristics of the ecological field. As a result of the research, a total of 51 metadata elements were derived for managing research data in the ecological field, and 6 essential elements, 23 recommended elements, and 22 optional elements were included. The results of this study can be used to design a DB when building a research data management and sharing system based on metadata elements, and to suggest a metadata exchange format when linking with other systems.

• Database Research
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• v.34 no.3
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• pp.69-85
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• 2018

Many researches proposed federated query engines to perform query on several homogeneous or heterogeneous datasets simultaneously that significantly improve the quality of query results. The existing techniques allow querying only over a few heterogeneous datasets considering the static binding using the non-standard query. However, we observe that a simultaneous system considering the integration of heterogeneous metadata standards can offer better opportunity to generalize the query over any homogeneous and heterogeneous datasets. In this paper, we propose a transparent federated engine (DRAZ) to query over multiple data sources using SPARQL. In our system, we first develop the ontology for a non-RDF metadata standard based on the metadata kernel dictionary elements, which are standardized by the metadata provider. For a given SPARQL query, we translate any triple pattern into an API call to access the dataset of corresponding non-RDF metadata standard. We convert the results of every API call to N-triples and summarize the final results considering all triple patterns. We evaluated our proposed DRAZ using modified Fedbench benchmark queries over heterogeneous metadata standards, such as DCAT and DOI. We observed that DRAZ can achieve 70 to 100 percent correctness of the results despite the unavailability of the JOIN operations.

• ETRI Journal
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• v.43 no.5
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• pp.835-855
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• 2021

With the recent increase in data disclosure, the Comprehensive Knowledge Archive Network (CKAN), which is an open-source data distribution platform, is drawing much attention. CKAN is used together with additional extensions, such as Datastore and Datapusher for data management and Harvest and DCAT for data collection. This study derives the problems of CKAN itself and Harvest Extension. First, CKAN causes two problems of data inconsistency and storage space waste for data deletion. Second, Harvest Extension causes three additional problems, namely source deletion that deletes only sources without deleting data themselves, job stop that cannot delete job during data collection, and service interruption that cannot provide service, even if data exist. Based on these observations, we propose herein an improved CKAN that provides a new deletion function solving data inconsistency and storage space waste problems. In addition, we present an improved Harvest Extension solving three problems of the legacy Harvest Extension. We verify the correctness and the usefulness of the improved CKAN and Harvest Extension functions through actual implementation and extensive experiments.

• Journal of Korean Library and Information Science Society
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• v.53 no.3
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• pp.241-262
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• 2022

The purpose of this study was to designed the structure and elements of metadata that can manage and share research data produced in the food composition database. In order to derive metadata elements, mapping crosswalk was performed on 5 metadata such as DCAT, DataCite metadata schema 4.4, TTAK.KO-10.0976, AgMES, and FoodData Central. As a result of the study, the top 15 elements of the 'Resource information' metadata were derived, and 7 mendatory, 3 recommended and 5 optional elements, and the 'Composition analysis' metadata included 8 mendatory, 3 recommended and 1 optional element were derived to describe food composition research data, respectively. The derived metadata elements will be used as an item for systematic management of food composition data and can be used as basic data for sharing with domestic and international food composition databases.

• Progress in Medical Physics
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• v.25 no.4
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• pp.288-297
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• 2014

Dynamic conformal arc therapy (DCAT) and flattening-filter-free (FFF) beams are commonly adopted for efficient conformal dose delivery in stereotactic body radiation therapy (SBRT). Off-axis geometry (OAG) may be necessary to obtain full gantry rotation without collision, which has been shown to be beneficial for peripheral targets using flattened beams. In this study dose distributions in OAG using FFF were evaluated and the effect of mechanical rotation induced uncertainty was investigated. For the lateral target, OAG evaluation, sphere targets (2, 4, and 6 cm diameter) were placed at three locations (central axis, 3 cm off-axis, and 6 cm off-axis) in a representative patient CT set. For each target, DCAT plans under the same objective were obtained for 6X, 6FFF, 10X, and 10FFF. The parameters used to evaluate the quality of the plans were homogeneity index (HI), conformality indices (CI), and beam on time (BOT). Next, the mechanical rotation induced uncertainty was evaluated using five SBRT patient plans that were randomly selected from a group of patients with laterally located tumors. For each of the five cases, a plan was generated using OAG and CAG with the same prescription and coverage. Each was replanned to account for one degree collimator/couch rotation errors during delivery. Prescription isodose coverage, CI, and lung dose were evaluated. HI and CI values for the lateral target, OAG evaluation were similar for flattened and unflattened beams; however, 6FFF provided slightly better values than 10FFF in OAG. For all plans the HI and CI were acceptable with the maximum difference between flattened and unflattend beams being 0.1. FFF beams showed better conformality than flattened beams for low doses and small targets. Variation due to rotational error for isodose coverage, CI, and lung dose was generally smaller for CAG compared to OAG, with some of these comparisons reaching statistical significance. However, the variations in dose distributions for either treatment technique were small and may not be clinically significant. FFF beams showed acceptable dose distributions in OAG. Although 10FFF provides more dramatic BOT reduction, it generally provides less favorable dosimetric indices compared to 6FFF in OAG. Mechanical uncertainty in collimator and couch rotation had an increased effect for OAG compared to CAG; however, the variations in dose distributions for either treatment technique were minimal.

• Korean Journal of Occupational Therapy
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• v.26 no.4
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• pp.127-143
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• 2018

Objective : The purpose of this study was to compare with the effects of driving simulator and Dynavision training after stroke through the test of cognitive ability and driving performance. Methods : Twenty-one stroke patients were randomly classified to the driving simulator training group (N=11) and Dynavision training group (N=10), and were carried out respectively training for 15 times. The driving performances was measured by the driving simulator test, and cognitive-perceptive abilities was measured by the DriveABLE Cognitive Assessment Tool, Trail Making Test-A, Trail Making Test-B and Mini Mental State Examination-K. Results : The driving simulator training group showed significant changes in all cognitive tests and most of driving performances. The Dynavision training group also showed significant changes in all cognitive tests except for Trail Making Test-A and some driving performances. The significant differences on both groups were found regarding the estimated degree of results on the on-road evaluation, the number of off road accidents and collisions. In addition, the causal influence of the two training methods on these variables was analyzed to be more than 20%. Conclusion : The driving simulator and Dynavision training were found to be effective intervention in the driving rehabilitation after stroke. In particular, it was confirmed that the driving simulator is an effective training to improve overall driving ability of stroke patients. In addition, the difference in training effect between the two training methods was found to be more than 20%.