• Journal of People, Plants, and Environment
• /
• v.23 no.5
• /
• pp.495-506
• /
• 2020

Background and objective: This study conducted a conjoint analysis on early childhood teachers to find out their preferences in horticultural activities that are used as a means of education in early childhood education. Methods: For the conjoint analysis, five attributes of horticultural activities were selected. Attribute 1 was method of horticultural activities, divided into two levels: exclusive and integrated horticultural activities. Attribute 2 was object of horticultural activities, divided into three levels: fruit crops, vegetable crops, and floricultural crops. Attribute 3 was activity type, divided into three levels: big and small group, free choice, and outdoor play. Attribute 4 was place for horticultural activities, and divided into two levels: indoors and outdoors. Attribute 5 was time for horticultural activities, divided into two levels: 30 minutes and 30-60 minutes. The orthogonal design was used to extract 20 profiles, after which we conducted a survey on 320 early childhood teachers and analyzed the valid responses from 257 teachers. Results: The preference of early childhood teachers showed highest importance in object (29.1%), followed by activity type (23.2%), activity method (17.4%), time (16.1%), and place (14.2%) (Pearson's R = .591, p = .008). By level of each attribute, the importance was high in exclusive horticultural activities for activity method, big and small group for activity type, vegetable and floricultural crops for object, indoors for place, and 30 minutes for time. Conclusion: The horticultural program preferred by early childhood teachers is comprised of big and small group activities using vegetable and floricultural crops, carried out indoors for 30 minutes as an exclusive class.

• The Journal of Society for e-Business Studies
• /
• v.21 no.2
• /
• pp.61-79
• /
• 2016

Recently, digital broadcasting service is growing as a TV-based commerce market spread. However, in previous studies, many researchers studied TV home shopping and T-Commerce separately each other, and there is little research on the attribute to increase the satisfaction of consumers. In this study, we analyzed the attribute to increase satisfaction of consumer using TV-based commerce, and we propose to the direction to move forward. We selected characteristics of TV home shopping and T-Commerce through previous studies, and analyzed satisfaction of customers with quality attributes of TV-based commerce using KANO model and ASC(Average Satisfaction Coefficient).

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.7 no.5
• /
• pp.1343-1356
• /
• 2013

Cloud computing has emerged as perhaps the hottest development in information technology at present. This new computing technology requires that the users ensure that their infrastructure is safety and that their data and applications are protected. In addition, the customer must ensure that the provider has taken the proper security measures to protect their information. In order to achieve fine-grained and flexible access control for cloud computing, a new construction of hierarchical attribute-based encryption(HABE) with Ciphertext-Policy is proposed in this paper. The proposed scheme inherits flexibility and delegation of hierarchical identity-based cryptography, and achieves scalability due to the hierarchical structure. The new scheme has constant size ciphertexts since it consists of two group elements. In addition, the security of the new construction is achieved in the standard model which avoids the potential defects in the existing works. Under the decision bilinear Diffie-Hellman exponent assumption, the proposed scheme is provable security against Chosen-plaintext Attack(CPA). Furthermore, we also show the proposed scheme can be transferred to a CCA(Chosen-ciphertext Attack) secure scheme.

• Journal of the Korea Society of Computer and Information
• /
• v.7 no.2
• /
• pp.9-18
• /
• 2002

SECOS(SoonChunHyang E-Commerce System) is the e-commerce system which was developed by e-commerce software research center in soonchunhyang univ. The system was composed of payment system, retrieving system and framework being used to combine these systems. The modules in the system was composed of components which was developed by CBSE(Component Based Software Engineering) method. In this paper. we implement the Role Based Access Control(RBAC) component for access control of SECOS. We use Attribute Certificates(ACs) in order to implement RBAC in the distributed retrieving system, and implement Attribute Authorities(AAs) which can provide ACs. The Proposed system is implemented by EIB component based JAVA.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37 no.4B
• /
• pp.288-299
• /
• 2012

To ensure data confidentiality and fine-grained access control in business environment, system model using KP-ABE(Key Policy-Attribute Based Encryption) and PRE(Proxy Re-Encryption) has been proposed recently. However, in previous study, data confidentiality has been effected by decryption right concentrated on cloud server. Also, Yu's work does not consider a access privilege management, so existing work become dangerous to collusion attack between malicious user and cloud server. To resolve this problem, we propose secure system model against collusion attack through dividing data file into header which is sent to privilege manager group and body which is sent to cloud server and prevent modification attack for proxy re-encryption key using d Secret Sharing, We construct protocol model in medical environment.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2013.05a
• /
• pp.648-651
• /
• 2013

클라우드 시스템에서는 데이터 소유자가 아닌 클라우드 서비스 제공자가 각 개인의 데이터에 대한 저장과 관리를 책임진다. 따라서 클라우드 서버 상의 사용자 데이터에 대한 보안을 보장해 주는 것이 가장 중요한 이슈이다. 데이터 보안 문제는 안전하고 효율적인 접근제어 기술을 통해 해결 할 수 있다. 기존 시스템에서 많이 이용되고 있는 RBAC(Role based access control)은 접근제어의 형태가 주로 수직적이고, 데이터 접근가능 여부를 역할이라는 고정적인 값에 따라 결정하기 때문에 동적인 클라우드 환경에 적합하지 않다. 반면 HASBE(Hierarchical attribute set based encryption) 모델은 ABAC(Attribute based access control)를 통해 유연하고 탄력적인 접근제어를 제공한다. 또한 HASBE 는 인가자(Authority)와 사용자의 관계 모델이 계층적인 구조를 갖고 있기 때문에 큰 조직에서 수많은 사용자들의 데이터 관리와 키 분배를 좀더 효율적으로 할 수 있다. 본 논문에서는 위의 계층적인 모델에서 더 나아가서, 실제 클라우드 환경에서 데이터가 가질 수 있는 복잡한 속성과 인가자의 관계를 고려해 다중 인가자의 개념이 더해진 모델을 제안한다.

• Journal of the Korea Society for Simulation
• /
• v.18 no.2
• /
• pp.39-48
• /
• 2009

This study reviews the limit of image search by considering on the image search methods related to content-based image retrieval and suggests a user interface for more efficient content-based image retrieval and the ways to utilize image properties. For now, most studies on image search are being performed focusing on content-based image retrieval; they try to search based on the image's colors, texture, shapes, and the overall form of the image. However, the results are not satisfactory because there are various technological limits. Accordingly, this study suggests a new retrieval system which adapts content-based image retrieval and the conventional keyword search method. This is about a way to attribute properties to images using texts and a fast way to search images by expressing the attribute of images as keywords and utilizing them to search images. Also, the study focuses on a simulation for a user interface to make query language on the Internet and a search for clothes in an online shopping mall as an application of the retrieval system based on image attribute. This study will contribute to adding a new purchase pattern in online shopping malls and to the development of the area of similar image search.

• Korean Journal of Construction Engineering and Management
• /
• v.11 no.4
• /
• pp.22-31
• /
• 2010

Because the estimated cost at early stage has great influence on decisions of project owner, the importance of early cost estimation is increasing. However, it depends on experience and knowledge of the estimator mainly due to shortage of information. Those tendency developed into case-based reasoning(CBR) method which solves new problems by adapting previous solution to similar past problems. The performance of CBR model is affected by attribute weight, so that its accurate determination is necessary. Previous research utilizes mathematical method or subjective judgement of estimator. In order to improve the problem of previous research, this suggests CBR schematic cost estimation method using genetic algorithm to determine attribute weight. The cost model employs nearest neighbor retrieval for selecting past case. And it estimates the cost of new cases based on cost information of extracted cases. As the result of validation for 17 testing cases, 3.57% of error rate is calculated. This rate is superior to accuracy rate proposed by AACE and the method to determine attribute weight using multiple regression analysis and feature counting. The CBR cost estimation method improve the accuracy by introducing genetic algorithm for attribute weight. Moreover, this makes user understand the problem-solving process easier than other artificial intelligence method, and find solution within short time through case retrieval algorithm.

• Journal of Broadcast Engineering
• /
• v.14 no.3
• /
• pp.280-287
• /
• 2009

An IPTV (Internet Protocol Television) technology is the new convergence technology of the telecommunication and broadcasting which provides various bidirectional TV services. To provide these services only to legal subscribers, mutual authentication between set-top box connected with TV set and the smart card owned by a subscriber is needed. In this paper, we propose an attribute-based mutual authentication scheme that only someone who is satisfied with some attributes, such as titles or departments, can access the contents provided by the IPTV service in an organization. We also show that the proposed scheme is secure. Our proposed scheme has a virtue that user can access various services, provided by an organization where he/she belongs to, according to their attributes with only one time registration. As far as we know, this is the first attribute-based authentication scheme which can be applied to any organizations in IPTV environments.

• Journal of KIISE
• /
• v.43 no.8
• /
• pp.933-945
• /
• 2016

Sharing data by multiple users on the public storage, e.g., the cloud, is considered to be efficient because the cloud provides on-demand computing service at anytime and anywhere. Secure data sharing is achieved by fine-grained access control. Existing symmetric and public key encryption schemes are not suitable for secure data sharing because they support 1-to-1 relationship between a ciphertext and a secret key. Attribute based encryption supports fine-grained access control, however it incurs linearly increasing ciphertexts as the number of attributes increases. Additionally, the decryption process has high computational cost so that it is not applicable in case of resource-constrained environments. In this study, we propose an efficient attribute-based secure data sharing scheme with outsourceable decryption. The proposed scheme guarantees constant-size ciphertexts irrespective of the number of attributes. In case of static attributes, the computation cost to the user is reduced by delegating approximately 95.3% of decryption operations to the more powerful storage systems, whereas 72.3% of decryption operations are outsourced in terms of dynamic attributes.