• Journal of Information Processing Systems
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• 제15권4호
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• pp.717-723
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• 2019

Smart systems and services aim to facilitate growing urban populations and their prospects of virtual-real social behaviors, gig economies, factory automation, knowledge-based workforce, integrated societies, modern living, among many more. To satisfy these objectives, smart systems and services must comprises of a complex set of features such as security, ease of use and user friendliness, manageability, scalability, adaptivity, intelligent behavior, and personalization. Recently, artificial intelligence (AI) is realized as a data-driven technology to provide an efficient knowledge representation, semantic modeling, and can support a cognitive behavior aspect of the system. In this paper, an integration of AI with the smart systems and services is presented to mitigate the existing challenges. Several novel researches work in terms of frameworks, architectures, paradigms, and algorithms are discussed to provide possible solutions against the existing challenges in the AI-based smart systems and services. Such novel research works involve efficient shape image retrieval, speech signal processing, dynamic thermal rating, advanced persistent threat tactics, user authentication, and so on.

• 유통과학연구
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• 제14권6호
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• pp.53-63
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• 2016

Purpose - This study examines the effects of the influence strategies on sales representative and headquarter trust, and investigates how sales representative trust plays a mediating role in the relationship between influence strategies and headquarter trust. For these purposes, a structural model which consists of several constructs was developed. In this model, influence strategies that consist of relational influence strategies (information exchange, recommend, promise) and mandatory influence strategies (legal plea, request, threat) were proposed to affect the sales representative trust and in turn, increase the headquarter trust. Thus, this study proposed that sale representative trust plays a core mediating role in the relationship between relational and mandatory influence strategies and headquarter trust in B2B food materials distribution context. Research design, data, and methodology - For these purposes, the authors collected the data from 208 B2B specialized complex agents. We used the 2,200 B2B specialized complex agents which trade with CJ, Ottogi, and Daesang firms and supply food materials to restaurant, school cafeteria, supermarket and traditional market as a sample frame. Once we identified 330 B2B specialized complex agent owners, CEOs, and/or Directors who had agreed to participate in this study, we dropped off a questionnaire at each B2B specialized complex agent and explained the purpose of this study. The survey was conducted from October 1, 2015 to December 15, 2015. A total of 230 questionnaires were collected. Of these collected questionnaires, 28 questionnaires excluded since they had not been fully completed. The data were analyzed using frequency test, reliability test, measurement model analysis, and structural equation modeling with SPSS and SmartPLS 2. Results - First, information exchange, recommendation, and promise of relational influence strategies had positive effects on sales representative trust. The threat of mandatory influence strategies had a negative effect on sales representative trust, but legal plea and request did not have a significant effect on sales representative trust. Second, information exchange and recommendation of relational influence strategies had positive effects on headquarter trust, but promise did not. Also, legal plea, request, and threat of mandatory influence strategies did not have a significant effect on headquarter trust. Third, this findings show that sales representative trust plays a partial mediator between information exchange and headquarter trust, and threat and headquarter trust, and a full mediator between promise and headquarter trust, and recommendation and headquarter trust. Conclusions - The aim of this study was to examine the effects how diverse dimensions of relational and mandatory influence strategies relate to sales representative trust and headquarter trust. To do so, we integrated the influence strategies and the trust transfer theory to hypothesize that various influence strategies increase sales representative and headquarter trust. The findings of this study suggest that headquarter firms should establish and enforce proper influence strategies guidelines to make clear what proper actions sales representatives should implement in relationship with B2B specialized complex agents. Also, relational and mandatory influence strategies must be regarded as a long-term and ongoing strategy that eventually build a long-term orientation with B2B specialized complex agents and guarantee a company's sustainable growth and success.

• 한국컴퓨터정보학회논문지
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• 제25권8호
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• pp.31-37
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• 2020

본 논문에서는 사이버 전투실험 분석이 가능한 사이버 킬체인 및 MITRE ATT&CK 기반의 시스템 구성 및 분석 방법론을 제안한다. 사이버 킬체인을 기반으로 공격 과정을 모의하고, MITRE ATT&CK를 기반으로 공격 목적 및 구체적인 공격 방법을 적용하여, 실제 발생한 다양한 공격 및 새롭게 등장할 공격에 대한 시스템 위협 분석이 가능하도록 한다. 또한, 현 시스템(AS-IS)과 새로운 대응 시스템이 적용될 경우(TO-BE)에 대한 사이버 공격 및 대응 측면의 효과도 분석을 정량적으로 제시하여, 선제적 방어방책 및 소요 반영을 위한 의사결정에도 활용이 가능하다. 제안하는 시스템 및 방법론의 활용성을 제시하기 위해, 테스트베드 환경에서 프로토타입을 구축하고 사례 연구를 수행하였다. 제안된 방안은 사이버 전투실험의 기술 수준을 높여 사이버전 역량 강화에 기여할 것으로 기대한다.

• 한국시뮬레이션학회논문지
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• 제18권4호
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• pp.39-47
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• 2009

최근 특정 기업 또는 웹사이트에 대한 분산 서비스 거부 공격(DDoS:Distributed Denial of Service) 위협이 증가함에 따라 많은 기업들이 DDoS 공격 방어를 위한 보안 솔루션을 도입하고 있다. DDoS 공격은 대량의 트래픽을 네트워크에 전송함으로써 자원을 고갈시키고 정상적인 서비스 제공을 불가능하게 한다. DDoS 공격은 사전 탐지가 힘들고 효율적인 방어가 매우 어렵다. 본 연구에서는 이러한 상황을 고려하여 모델링 시뮬레이션을 통한 DDoS 공격에 대한 유연한 대응 방법을 연구하고자 한다. 특히, 서버의 개수를 변경할 경우 나타나는 DDoS 공격에 대한 동적 특성을 분석하고, DDoS 공격으로 인한 피해 규모의 객관적 산정을 위해 DDoS 탐지 시스템 운영 여부에 따른 손실 비용을 산정하는 방법을 제시한다. DDoS 공격 시뮬레이션은 OPNET Modeler를 이용하여 모델링하고, 시뮬레이션 결과를 통해 DDoS 공격으로 인한 서비스 가능 시간을 도출하여 네트워크 구조에 따른 서비스 가능여부를 확인 할 수 있다. 본 논문에서 수행하는 DDoS 공격 시뮬레이션은 현재의 네트워크 구성을 평가하고 신규 장비의 설치 또는 네트워크 구조 변경 시 발생 가능한 문제점을 예측하는 데에 활용가능하다.

• Steel and Composite Structures
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• 제43권5호
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• pp.673-688
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• 2022

Post-earthquake fire is a major threat since most structures are designed allowing some damage during strong earthquakes, which will expose a more vulnerable structure to post-earthquake fire compared to an intact structure. A series of experimental research on steel-concrete composite beam-to-column joints subjected to fire after cyclic loading has been carried out and a clear reduction of fire resistance due to the partial damage caused by cyclic loading was observed. In this paper, by using ABAQUS a robust finite element model is developed for exploring the performance of steel-concrete composite joints in post-earthquake fire scenarios. After validation of these models with the previously conducted experimental results, a comprehensive numerical analysis is performed, allowing influential parameters affecting the post-earthquake fire behavior of the steel-concrete composite joints to be identified. Specifically, the level of pre-damage induced by cyclic loading is regraded to deteriorate mechanical and thermal properties of concrete, material properties of steel, and thickness of the fire protection layer. It is found that the ultimate temperature of the joint is affected by the load ratio while fire-resistant duration is relevant to the heating rate, both of which change due to the damage induced by the cyclic loading.

• 한국해양공학회지
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• 제37권4호
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• pp.145-157
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• 2023

Due to a recent increase in maritime activities in South Korea, the frequency of maritime distress is escalating and poses a significant threat to lives and property. The aim of this study was to validate a drift trajectory prediction technique to help mitigate the damages caused by maritime distress incidents. In this study, OpenDrift was verified using satellite drifter data from the Korea Hydrographic and Oceanographic Agency. OpenDrift is a Monte-Carlo-based Lagrangian trajectory modeling framework that allows for considering leeway, an important factor in predicting the movement of floating marine objects. The simulation results showed no significant differences in the performance of drift trajectory prediction when considering leeway using four evaluation methods (normalized cumulative Lagrangian separation, root mean squared error, mean absolute error, and Euclidean distance). However, leeway improved the performance in an analysis of location prediction conformance for maritime search and rescue operations. Therefore, the findings of this study suggest that it is important to consider leeway in drift trajectory prediction for effective maritime search and rescue operations. The results could help with future research on drift trajectory prediction of various floating objects, including marine debris, satellite drifters, and sea ice.

• 한국환경보건학회지
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• 제41권2호
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• pp.90-101
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• 2015

Objective: This study was conducted to develop a chemical oxygen demand (COD) regression model using water quality monitoring data (January, 2014) obtained from the Han River auto-monitoring stations. Methods: Surface water quality data at 198 sampling stations along the six major areas were assembled and analyzed to determine the spatial distribution and clustering of monitoring stations based on 18 WQPs and regression modeling using selected parameters. Statistical techniques, including combined genetic algorithm-multiple linear regression (GA-MLR), cluster analysis (CA) and principal component analysis (PCA) were used to build a COD model using water quality data. Results: A best GA-MLR model facilitated computing the WQPs for a 5-descriptor COD model with satisfactory statistical results ($r^2=92.64$,$Q{^2}_{LOO}=91.45$,$Q{^2}_{Ext}=88.17$). This approach includes variable selection of the WQPs in order to find the most important factors affecting water quality. Additionally, ordination techniques like PCA and CA were used to classify monitoring stations. The biplot based on the first two principal components (PCs) of the PCA model identified three distinct groups of stations, but also differs with respect to the correlation with WQPs, which enables better interpretation of the water quality characteristics at particular stations as of January 2014. Conclusion: This data analysis procedure appears to provide an efficient means of modelling water quality by interpreting and defining its most essential variables, such as TOC and BOD. The water parameters selected in a COD model as most important in contributing to environmental health and water pollution can be utilized for the application of water quality management strategies. At present, the river is under threat of anthropogenic disturbances during festival periods, especially at upstream areas.

• Nuclear Engineering and Technology
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• 제44권8호
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• pp.919-928
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• 2012

The applications of computers and communication system and network technologies in nuclear power plants have expanded recently. This application of digital technologies to the instrumentation and control systems of nuclear power plants brings with it the cyber security concerns similar to other critical infrastructures. Cyber security risk assessments for digital instrumentation and control systems have become more crucial in the development of new systems and in the operation of existing systems. Although the instrumentation and control systems of nuclear power plants are similar to industrial control systems, the former have specifications that differ from the latter in terms of architecture and function, in order to satisfy nuclear safety requirements, which need different methods for the application of cyber security risk assessment. In this paper, the characteristics of nuclear power plant instrumentation and control systems are described, and the considerations needed when conducting cyber security risk assessments in accordance with the lifecycle process of instrumentation and control systems are discussed. For cyber security risk assessments of instrumentation and control systems, the activities and considerations necessary for assessments during the system design phase or component design and equipment supply phase are presented in the following 6 steps: 1) System Identification and Cyber Security Modeling, 2) Asset and Impact Analysis, 3) Threat Analysis, 4) Vulnerability Analysis, 5) Security Control Design, and 6) Penetration test. The results from an application of the method to a digital reactor protection system are described.

• 한국시뮬레이션학회논문지
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• 제32권3호
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• pp.9-21
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• 2023

최근 러시아·우크라이나 전쟁에서 볼 수 있듯이 군수지원은 현대전에서 빼놓을 수 없는 중요한 요소 중의 하나이다. 군수지원은 모의 논리의 특수성과 복잡성으로 인해 대부대 분석 모델과 전문적인 기능 모델 중심으로 발전되어 왔지만, 교전급 분석 모델에서는 군수지원에 대한 요구가 상대적으로 높지 않았다. 그러나 대대급 이하 제대에서도 무인 수송자산을 이용한 재보급 필요성이 제기되면서, 이의 전투 효과를 분석하기 위한 모의 기법도 함께 요구되고 있다. 이에 본 연구에서는 대대급 이하 제대의 탄약 재보급 논리를 기반으로 교전급 분석 모델을 위한 재보급 과업 모델을 설계한다. 재보급 과업 모델은 다음과 같은 순서로 도출되는 의사결정트리를 기반으로 동작한다. 먼저, 사전 반복 모의실험을 통해 여러 가지 쌍방 교전 조건과 아군의 탄 잔여량에 따른 피아 손실교환비를 수집한다. 이어서, 쌍방 교전 조건, 탄 잔여량, 손실교환비로 표현되는 의사결정 트리를 만든다. 의사결정트리는 전투모의 실행 간에 적의 위협 강도, 피지원 부대의 탄 잔여량 등을 고려하여 재보급 우선순위를 결정하는 데 사용된다. 끝으로 제안된 모델의 실행 가능성을 OneSAF 기반 소부대 전투 모의실험을 통해 입증한다.

• 국제지역연구
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• 제15권2호
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• pp.141-168
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• 2011

한·중·일 대학생의 국민정체성과 다문화태도의 관계를 탐구하였다. 이를 위해 부산대학교 사회과학연구소가 조사한 "한·중·일 대학생의 다문화태도" 자료를 사용하였으며, 일원배치분산분석(ANOVA), Scheffe 사후검정, 구조방정식 모델링, 다집단분석을 이용하였다. 연구결과, 첫째, 중국 대학생은 혈통적 정체성과 시민적 정체성 모두 비교 국가 대학생보다 높은 것으로 나타났다. 한국 대학생은 혈통적 정체성이, 일본 대학생은 시민적 정체성이 비교 국가 대학생보다 낮은 것으로 나타났다. 둘째, 다문화태도의 경우 한국 대학생들은 일자리, 경제 기여 등에서, 중국 대학생들은 사회문제, 외국 집단 거주 등에서, 일본 대학생들은 혈통훼손, 세금 증가 등에서 비교 국가 대학생보다 인지된 위협 수준이 높았다. 셋째, 국민정체성 각 하위 요인은 다문화태도에 각각 독립적이기보다는 상호 영향관계 속에서 다문화태도에 영향을 미치는 것으로 나타났다.