• 한국컴퓨터정보학회논문지
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• 제28권10호
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• pp.155-161
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• 2023

본 논문에서는 승강기 비상통화 장치의 활용성과 안정성을 높이기 위해 상시 모니터링 환경의 서비스 체계를 구축하는 WebRTC 기반의 비상 화상통화 시스템 구조를 제시한다. 제시된 시스템은 비상상황 시 승강기 내의 비상 호출 시스템과 유지보수 담당자들 간의 원활한 통화 환경을 제공하고 대상 승강기의 모니터링을 통해 승강기 비상 호출에 대한 신속한 응답 처리를 수행하고 승강기의 물리적 공간에서 발생할 수 있는 화상통화에 필요한 제약환경을 극복하여 음성과 영상의 저지연 실시간 화상통화 서비스를 구현할 수 있는 환경을 구축하고자 한다. 이를 위해 현재 다양한 분야에서 활용되고 그 성능이 검증된 OpenAPI를 기반으로 서비스 환경을 구축하고 실시간 화상통화 및 저지연 통화 품질 제공, 그리고 신속한 메시징 방식의 비상상황 전파 방식을 통해 비상 화상통화 장치의 성능 및 활용성을 높이고자 한다. 제시된 시스템 구조는 승강기 제어반 및 다양한 장치와의 결합을 통해 다양한 기능 확장 및 신뢰성 있는 서비스 환경을 통해 승강기 시스템에 대한 지능적 모델을 구성할 수 있는 기반을 제공할 수 있을 것이다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2021년도 춘계학술대회
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• pp.67-67
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• 2021

The genus Glycyrrhiza (Licorice) has been used as an oriental herbal medicine for a long time in Asian countries. Wongam (WG), which is Glycyrrhiza new variety, have been developed to improve limitation of licorice including low productivity, environmental restriction and insufficient components by Korea Rural Development Administration. To using WG as a herbal medicine, it is important to reveal the adverse effects in health. In this study, we evaluated the genotoxicity test of WG extract through in vitro bacterial reverse mutation (AMES) assay, in vitro chromosomal aberration assay and in vivo mouse bone marrow micronucleus assay. When compared with the control, WG extract with or without the S9 mix showed no genotoxicity in the AMES assay up to 5000 ㎍/plate and in the chromosomal aberration assay up to 1100 ㎍/ml. In micronucleus assay, no significant increase in the number of micronucleated polychromatic erythrocytes or in the mean ratio of polychromatic to total erythrocytes up to 5000 mg/kg/day for 2 days. The present study demonstrated that WG extract is safe and reliable herbal medicine since no detectable genotoxic effects at least under the conditions of this study.

• Wind and Structures
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• 제37권6호
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• pp.445-460
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• 2023

Accurate estimation of modal parameters (i.e., natural frequency, damping ratio) of tall buildings is of great importance to their structural design, structural health monitoring, vibration control, and state assessment. Based on the combination of variational mode decomposition, smoothed discrete energy separation algorithm-1, and Half-cycle energy operator (VMD-SH), this paper presents a method for structural modal parameter estimation. The variational mode decomposition is proved to be effective and reliable for decomposing the mixed-signal with low frequencies and damping ratios, and the validity of both smoothed discrete energy separation algorithm-1 and Half-cycle energy operator in the modal identification of a single modal system is verified. By incorporating these techniques, the VMD-SH method is able to accurately identify and extract the various modes present in a signal, providing improved insights into its underlying structure and behavior. Subsequently, a numerical study of a four-story frame structure is conducted using the Newmark-β method, and it is found that the relative errors of natural frequency and damping ratio estimated by the presented method are much smaller than those by traditional methods, validating the effectiveness and accuracy of the combined method for the modal identification of the multi-modal system. Furthermore, the presented method is employed to estimate modal parameters of a full-scale tall building utilizing acceleration responses. The identified results verify the applicability and accuracy of the presented VMD-SH method in field measurements. The study demonstrates the effectiveness and robustness of the proposed VMD-SH method in accurately estimating modal parameters of tall buildings from acceleration response data.

• 대한한의학회지
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• 제44권3호
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• pp.189-200
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• 2023

Objectives: The purpose of this study is to analyze the current state of quantitative literature evidence for the prescription of 56 herbal medicines covered by health insurance that have been studied in Korea for the past 30 years, to evaluate the reliability of the evidence, and to find out the research direction of herbal medicine prescription in the future. Methods: 56 kinds of herbal medicine prescriptions were searched in domestic literature search databases OASIS, DBpia, and overseas PubMed, classified into chemistry, toxicity, cells, animals, clinical cases, and clinical trial studies, and built into an EBM pyramid structure. Results: When classified according to research contents, there were 61 cases (7.5%) of physicochemical analysis to identify constituent substances, 80 cases (9.8%) of toxicity evaluation, and 672 cases (82.7%) of efficacy evaluation. The efficacy evidence was classified according to the evidence-based medical pyramid structure: 196 cell trials (29.1%), 372 animal trials (55.4%), 89 case and case reporting series (13.3%), 7 comparative case studies (1.1%), and 8 randomized control clinical trials (1.2%). In the pyramid composition, the basis for the validity of 56 kinds of herbal medicines prescribed was 568 cases (84.5%) in cell and animal units, which could not be said to be highly reliable. There was no relationship between the ranking of quantitative literature evidence for herbal medicine prescriptions and the ranking of salary administration. Conclusions: In an era that continues to require scientific evidence for herbal medicine, traditional herbal medicine should secure the basis for safety validity even for the 10th most frequent prescription among 56 herbal medicine prescriptions for consumers. In particular, traditional herbal medicine should increase the quantitative and qualitative level of case reports on related herbal medicine prescriptions, focusing on each clinical society, and move toward comparative case studies and randomized clinical trial so that traditional herbal medicine is positioned as Evidence-based medicine.

• International Journal of Computer Science & Network Security
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• 제24권3호
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• pp.23-28
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• 2024

The multi-tenancy and high scalability of the cloud have inspired businesses and organizations across various sectors to adopt and deploy cloud computing. Cloud computing provides cost-effective, reliable, and convenient access to pooled resources, including storage, servers, and networking. Cloud service models, SaaS, PaaS, and IaaS, enable organizations, developers, and end users to access resources, develop and deploy applications, and provide access to pooled computing infrastructure. Despite the benefits, cloud service models are vulnerable to multiple security and privacy attacks and threats. The SaaS layer is on top of the PaaS, and the IaaS is the bottom layer of the model. The software is hosted by a platform offered as a service through an infrastructure provided by a cloud computing provider. The Hypertext Transfer Protocol (HTTP) delivers cloud-based apps through a web browser. The stateless nature of HTTP facilitates session hijacking and related attacks. The Open Web Applications Security Project identifies web apps' most critical security risks as SQL injections, cross-site scripting, sensitive data leakage, lack of functional access control, and broken authentication. The systematic literature review reveals that data security, application-level security, and authentication are the primary security threats in the SaaS model. The recommended solutions to enhance security in SaaS include Elliptic-curve cryptography and Identity-based encryption. Integration and security challenges in PaaS and IaaS can be effectively addressed using well-defined APIs, implementing Service Level Agreements (SLAs), and standard syntax for cloud provisioning.

• 한국음향학회지
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• 제26권1호
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• pp.48-54
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• 2007

본 논문에서는 수중에서 이동체의 3차원 위치를 추정하기 위한 위치추적 시스템을 구현하였다. 본 연구에서는 네 개의 초음파 센서를 수중의 서로 다른 위치에 고정시키고, 이동중인 이동체 센서와 서로 다른 신호를 송 수신하게 함으로써 고정체와 이동체 모두에서 이동체의 3차원 위치 추적과 이동체의 원격제어를 가능하게 하였다. 또한 위치 추적 시에 Newton 알고리즘에서 매 iteration 시에 Jacobian 행렬의 norm을 추정하고, 행렬의 norm이 임계값 이상이 되어 역행렬에 의한 해가 불안정해질 때는 또 다른 초기값을 이용하여 해를 구하게 함으로써 이동체의 위치가 보다 신뢰성 있게 추정되게 하였다. 그리고 제안한 알고리즘을 이용하여 실시간 위치 추적이 가능한 위치 추적 DSP 시스템을 구현하였으며, 성능 검증을 위한 수조 실험을 수행하였다. 성능 검증결과 본 연구에서 구현한 위치 추적 시스템은 1초에 2회 이상의 속도로 오차율 5cm 이내에서 이동체의 위치를 추적함을 알 수 있었다.

• 한국음향학회지
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• 제28권1호
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• pp.70-76
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• 2009

주변 잡음이 심한 환경의 음성 통신에서 음성 명료도는 주변 잡음의 마스킹 효과로 인하여 크게 저하된다. 본 논문에서는 잡음 환경에서 음성 명료도를 향상시켜 통화 품질을 높이는 새로운 방법을 제안한다. 청각 이론에 의하면 음성의 시간축포락선은 명료도 결정에 중요한 역할을 한다. 이에 따라 본 논문에서는 대역별 시간축 포락선의 변화를 강화하여 명료도를 향상시키는 방법을 사용하며, 음질을 추가로 향상시키기 위한 피치 강화동작을 포함한다. 또한, 실제 통화상황에서의 정확한 주관적 성능 평가를 위하여 양 귀를 이용하는 새로운 주관적 성능 평가 방법을 제안한다. 제안하는 평가 방식을 통하여 제안하는 명료도 향상 기술의 성능을 평가하였으며, 명료도와 음질이 모두 향상되는 것을 확인하였고, 동작 파라미터 조정을 통하여 명료도와 음질 사이의 상호 관계가 조정되는 것을 확인하였다.

• 융합보안논문지
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• 제24권2호
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• pp.9-17
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• 2024

본 논문은 기업 내 생성형 AI(Generative Artificial Intelligence) 시스템의 보안 위협과 대응 방안을 제시한다. AI 시스템이 방대한 데이터를 다루면서 기업의 핵심 경쟁력을 확보하는 한편, AI 시스템을 표적으로 하는 보안 위협에 대비해야 한다. AI 보안 위협은 기존 사람을 타겟으로 하는 사이버 보안 위협과 차별화된 특징을 가지므로, AI에 특화된 대응 체계 구축이 시급하다. 본 연구는 AI 시스템 보안의 중요성과 주요 위협 요인을 분석하고, 기술적/관리적 대응 방안을 제시한다. 먼저 AI 시스템이 구동되는 IT 인프라 보안을 강화하고, AI 모델 자체의 견고성을 높이기 위해 적대적 학습 (adversarial learning), 모델 경량화(model quantization) 등 방어 기술을 활용할 것을 제안한다. 아울러 내부자 위협을 감지하기 위해, AI 질의응답 과정에서 발생하는 이상 징후를 탐지할 수 있는 AI 보안 체계 설계 방안을 제시한다. 또한 사이버 킬 체인 개념을 도입하여 AI 모델 유출을 방지하기 위한 변경 통제와 감사 체계 확립을 강조한다. AI 기술이 빠르게 발전하는 만큼 AI 모델 및 데이터 보안, 내부 위협 탐지, 전문 인력 육성 등에 역량을 집중함으로써 기업은 안전하고 신뢰할 수 있는 AI 활용을 통해 디지털 경쟁력을 제고할 수 있을 것이다.

• 한국식품저장유통학회지
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• 제30권6호
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• pp.929-943
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• 2023

This study analyzed the variation in vitamin K content in conger eel (Conger myriaster) caught off Tongyeong, Gyeongsangnam-do, Korea, focusing on the influence of size (large and small) and harvest period (monthly throughout 2021). We applied enzymatic extraction and HPLC-fluorescence methods for the analysis of vitamin K₁ (phylloquinone) and K₂ (menaquinone). The vitamin K content in conger eel varied significantly with size and harvest season (p<0.05). In large-sized samples, the phylloquinone content peaked in July (0.80±0.09 ㎍/100 g), while the highest menaquinone content was in May (0.79±0.11 ㎍/100 g). Conversely, in small-sized conger eels, the highest phylloquinone was found in December (1.94±0.15 ㎍/100 g), and the peak menaquinone level was in January (0.66±0.02 ㎍/100 g). The fat content was highest in July for large samples and in January for smaller ones. There was a positive correlation between fat and total vitamin K contents in conger eel (r=0.631, 0.667). Method validation and quality control measures ensured data reliability for vitamin K₁ and K₂ analyses. This study provides reliable information on the size and seasonal variations of vitamin K in conger eels, a staple in the Korean diet. This information is valuable for inclusion in Korea's national food nutrition database and for formulating future national health and nutrition policies.

• International Journal of Computer Science & Network Security
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• 제24권5호
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• pp.135-155
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• 2024

Urban public health monitoring in smart cities focuses on the control of conditions and health challenges in urban environments. Considering the rapid spread of diseases and pandemics, it is important for health authorities to trace people carrying the virus. In smart cities, this tracing must be interoperable and intelligent, especially in indoor surfaces characterized by small distances between people. Therefore, to fight pandemics, it is necessary to start with the already-existing digital equipment of the Internet of Things, such as connected objects and smartphones. In this study, the developed system is employed to provide a social IoT network and suggest a strategy which allows reliable traceability without threatening the privacy of users. This IoT-based system allows respecting the social distance between persons sharing public services in smart cities without applying smartphone applications or severe confinement. It also permits a return to normal life in case of viral pandemic and ensures the much-desired balance between economy and health. The present study analyses previous proposed social distance systems then, unlike these studies, suggests an intelligent and distributed IoT based strategy for positioning students. Two scenarios of static and dynamic optimization-based placement of Bluetooth Low Energy devices are proposed and an experimental study shows the contribution and complementarity of the introduced contact tracing strategy with the applications on smartphones.