• Geomechanics and Engineering
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• v.25 no.1
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• pp.17-30
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• 2021

This paper develops a convenient approach for deterministic and probabilistic evaluations of tunnel face stability using support vector machine classifiers. The proposed method is comprised of two major steps, i.e., construction of the training dataset and determination of instance-based classifiers. In step one, the orthogonal design is utilized to produce representative samples after the ranges and levels of the factors that influence tunnel face stability are specified. The training dataset is then labeled by two-dimensional strength reduction analyses embedded within OptumG2. For any unknown instance, the second step applies the training dataset for classification, which is achieved by an ad hoc Python program. The classification of unknown samples starts with selection of instance-based training samples using the k-nearest neighbors algorithm, followed by the construction of an instance-based SVM-KNN classifier. It eventually provides labels of the unknown instances, avoiding calculate its corresponding performance function. Probabilistic evaluations are performed by Monte Carlo simulation based on the SVM-KNN classifier. The ratio of the number of unstable samples to the total number of simulated samples is computed and is taken as the failure probability, which is validated and compared with the response surface method.

• International Journal of High-Rise Buildings
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• v.7 no.4
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• pp.265-285
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• 2018

This paper presents a state-of-the-art review on the design, research and education aspects of fire safety engineering (FSE) with a particular concern on high-rise buildings. FSE finds its root after Great Fire of Rome in 64 AD, followed by Great London Fire in 1666. The development of modern FSE is continuously driven by industry revolution, insurance community and government regulations. Now FSE has become a unique engineering discipline and is moving towards performance-based design since 1990s. The performance-based fire safety design (PBFSD) involves identification of fire safety goals, design objectives, establishment of performance criteria, and selection of proper solutions for fire safety. The determination of fire scenarios and design fires have now become major contents for PBFSD. To experience a rapid and positive evolution in design and research consistent with other engineering disciplines, it is important for fire safety engineering as a profession to set up a special educational system to deliver the next-generation fire safety engineers. High-rise buildings have their unique fire safety issues such as rapid fire and smoke spread, extended evacuation time, longer fire duration, mixed occupancies, etc., bringing more difficulties in ensuring life safety and protection of property and environment. A list of recommendations is proposed to improve the fire safety of high-rise buildings. In addition, some source information for specific knowledge and information on FSE is provided in Appendix.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.214-217
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• 2013

Advancements in automobile industries and the communication technologies caused VANET (Vehicular Ad Hoc NETwork) to evolve to VANET-based clouds before its deployment. It is more likely that VANET clouds will replace the traditional VANET in the deployment phase. It is to be noted that an abrupt deployment is out of question because it would require mass of resources and money to do so; instead incremental deployment is more ideal. In this paper, we aim at the incremental deployment phase of VANET clouds and focus on the well-established public transport networks. Data aggregation is one of the essential aspects in traditional VANET and has been researched for quite long time. However the previously proposed schemes are still controversial. Keeping in mind the time and space prediction of public buses, we leverage these buses as potential aggregators and MG (Mobile Gateways) in VANET clouds. Buses gather cooperative whereabouts information from neighbors, aggregate that information, disseminate it to the neighbor MGs and also send it to the cloud for storage and for services exchange. In our proposed scheme, we believe that the dissemination will be effective and cover most of the urban area since at any instant of time; buses cover most part of the urban areas. Besides, the effective transmission range is higher due to tall buses.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.5
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• pp.93-103
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• 2009

Since message forgery or alteration in VANET may cause severe consequences, authentication of critical messages must be provided. However, using normal digital signature may infringe privacy of drivers. Therefore, VANET requires authentication systems that provide conditional anonymity. In this paper, we propose a new authentication system for VANET. In our proposed system, each vehicle can update its pseudonym using re-encryption technique and digitally sign messages using representation problem on the pseudonym. By limiting the usage period, revocation of individual pseudonym is not required. Moreover, we also provide a way to revoke the vehicle itself. Secureness of our system partially rely on the usage of tamper-resistance hardware.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.4
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• pp.53-62
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• 2010

In VANETs (Vehicular Ad hoc NETwork), conditional anonymity must be provided to protect privacy of vehicles while enabling authorities to identify misbehaving vehicles. To this end, previous systems provide a mechanism to revoke the anonymity of individual messages. In VANET, if we can trace the movement path of vehicles, it can be useful in determining the liability of vehicles in car accidents and crime investigations. Although route tracing can be provided using previous message revocation techniques, they violate privacy of other vehicles. In this paper, we provide a route tracing technique that protects privacy of vehicles that are not targeted. The proposed method can be employed independently of the authentication mechanism used and includes a mechanism to prevent authorities from abusing this new function.

• Journal of Hospice and Palliative Care
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• v.26 no.2
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• pp.80-94
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• 2023

Purpose: This study aimed to identify attitudes toward advance directives (ADs) among female cancer patients and factors related to ADs. Methods: The study was conducted at a university hospital in Seoul from September 19, 2020, to January 20, 2021. The participants were 153 patients diagnosed with gynecological cancer or breast cancer. Data were collected using questionnaires and included general characteristics, disease- and AD-related characteristics, knowledge and attitudes about ADs, and attitudes about dignified death. Data were analyzed using the t-test, analysis of variance, and multiple regression analysis. Results: Only 2% of the participants completed ADs. The mean score for attitudes toward ADs was 3.30, indicating a positive knowledge and attitude toward dignified death. The factors related to attitudes toward ADs were attitudes toward dignified death (𝛽=0.25, P=0.001), experience discussing life-sustaining treatment (𝛽=0.17, P=0.037), preferred time to have a consultation about ADs (𝛽=0.19, P=0.046), intention to write ADs (𝛽=0.15, P=0.038), and Eastern Cooperative Oncology Group Performance Status (𝛽=-0.37, P<0.001). The explanatory power of these variables for attitudes toward ADs was 38.5%. Conclusion: Overall, patients preferred to have a consultation about ADs when they were still active, mentally healthy, and able to make decisions. Education about ADs should be provided to patients on the first day of hospitalization for chemotherapy or while awaiting treatment in an outpatient setting so patients can write ADs and discuss them with family and friends.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.9
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• pp.1-12
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• 2017

This study is the academic work to explore the potential meanings of print advertisements. Linguistic features such as repetition, variation, contrast and phonological structure in the verbal texts of ads can give rise to shades-of-meaning or slight variations in advertising. The language of advertising is not only language in words. It is also a language in images, colors, and pictures. Pictures and words combine to form the advertisement's visual text.. While the words are very important in delivering the sales message, the visual text cannot be ignored in advertisements. Forming part of the visual text is the paralanguage of the ad. Paralanguage is the meaningful behaviour accompanying language, such as voice quality, gestures, facial expressions and touch in speech, and choice of typeface and letter sizes in writing. Foregrounding is the throwing into relief of the linguistic sign against the background of the norms of ordinary language. This paper focuses its discussion on the advertisements within the framework of the paradigmatic and the syntagmatic relationship. The sources of ads have been confined to Malboro. The ads were reselected based on purposive sampling methods.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.01a
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• pp.335-336
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• 2022

본 논문에서는 시간대와 대화 주제를 활용하여 카테고리별로 적절한 SNS 광고 시간대 예측 방법을 제시한다. 위의 분석으로 광고주들에게 적절한 광고시간을 제안할 수 있다. 연관규칙분석 알고리즘인 apriori를 사용하였다. 주제는 상거래(쇼핑), 미용과 건강, 시사/교육, 식음료, 여가생활로 추려서 분석하였다. 연관분석 결과, 미용과 건강이 18시, 17시, 16시에 가장 활발히 대화를 나누었다. 상거래(쇼핑)이 14시, 16시, 17시 순으로 가장 활발히 대화를 나누었으며, 시사/교육이 15시, 17시, 16시 순으로 많은 대화를 나누었으며, 식음료가 18시, 17시, 19시 순으로 대화를 많이 나눈 것을 확인했다. 마지막으로, 여가생활은 22시, 23시, 21시 순으로 각각의 대화 주제별로 가장 많이 대화를 나눈 시간대가 달라지는 것을 확인할 수 있었다. 이를 통해 소비자 입장에서는 알맞은 광고를 적절한 시간대에 추천받을 수 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.05a
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• pp.1100-1103
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• 2008

VANET(Vehicle Ad-hoc Network) 환경은 도로위의 차량을 노드로 하여 구성하는 애드혹 네트워크로써 최근 들어 그 연구가 활발히 진행되고 있는 분야이다. 일반적인 애드혹 환경과 마찬가지로 VANET 환경에서도 보안적인 문제가 중요한 이슈로 대두되고 있다. VANET 환경에서 가장 중요하게 요구되는 보안요소는 차량의 익명성을 통한 위치 프라이버시와 협력 운전(cooperative driving) 단계에서 사용되는 메시지에 대한 인증, 무결성, 부인방지 등이다. 본 논문에서는 익명 아이디(pseudonym), 그룹화 등을 통해 차량의 위치 프라이버시를 제공하고 또한 이를 이용해 VANET 환경에서 사용할 수 있는 라우팅 프로토콜을 제안하고자 한다. RA(Registration Authority)에서 발급되는 익명 아이디의 집합과 차량의 전송 범위를 고려해서 구성되는 그룹화는 그룹에 속한 차량에 대해 익명성을 제공하고, 또한 그룹리더에 의해 생성되는 그룹키를 통해 효율적인 협력 운전 메시지 전달을 할 수 있게 된다. 그리고 각각의 그룹리더를 라우터로 이용해 전달되는 라우팅 프로토콜은 노드가 매우 유동적으로 움직이는 VANET 환경에서 효과적으로 메시지를 전달할 수 있도록 해줄 것이다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.3
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• pp.704-719
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• 2024

Botnet pandemics are becoming more prevalent with the growing use of mobile phone technologies. Mobile phone technologies provide a wide range of applications, including entertainment, commerce, education, and finance. In addition, botnet refers to the collection of compromised devices managed by a botmaster and engaging with each other via a command server to initiate an attack including phishing email, ad-click fraud, blockchain, and much more. As the number of botnet attacks rises, detecting harmful activities is becoming more challenging in handheld devices. Therefore, it is crucial to evaluate mobile botnet assaults to find the security vulnerabilities that occur through coordinated command servers causing major financial and ethical harm. For this purpose, we propose a hybrid analysis approach that integrates permissions and API and experiments on the machine-learning classifiers to detect mobile botnet applications. In this paper, the experiment employed benign, botnet, and malware applications for validation of the performance and accuracy of classifiers. The results conclude that a classifier model based on a simple decision tree obtained 99% accuracy with a low 0.003 false-positive rate than other machine learning classifiers for botnet applications detection. As an outcome of this paper, a hybrid approach enhances the accuracy of mobile botnet detection as compared to static and dynamic features when both are taken separately.