• 한국안전학회지
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• 제36권4호
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• pp.62-70
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• 2021

Representative systematic accident analysis methods proposed so far include AcciMap, STAMP, and FRAM. This study used these three techniques to analyze a fire accident case that occurred during routine manufacturing work in a domestic chemical plant and compared the results. The methods used different approaches to identify the cause of the accident, but they all highlighted similar causal factors. In addition to technical issues, the three accident analysis methods identified factors related to safety education, risk assessment, and the operation of the process safety management system, as well as management philosophy and company culture as problems. The AcciMap and STAMP models play complementary roles because they use hierarchical structures, while FRAM is more effective in analyses centered on human and organizational functions than in technical analyses.

• Journal of Positioning, Navigation, and Timing
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• 제11권4호
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• pp.229-238
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• 2022

This paper addresses on the International technical trends, standards, and development status of terrestrial radionavigation system to provide more accurate and fail-safe Positioning, Navigation, and Timing (PNT) Information available in maritime navigation environment. We analyze the performance result of pilot service in enhanced Long range navigation (eLoran) testbed environment using Low Frequency (LF) signal, and describe the development status of Ranging-Mode (R-Mode) system using Medium Frequency (MF) and Very High Frequency (VHF) to meet the Harbor Entrances and Approaches (HEA) requirement of International Maritime Organization (IMO) within 10m position accuracy. Furthermore, we present an architecture for integrated service of satellite-terrestrial navigation system and future maritime applicable fields. As the core information infrastructure of future navigation for 4th industrial revolution, this paper will be contributed to determining the direction of present and future to provide fail-safe PNT service with Global Navigation Satellite System (GNSS) based on the technical enhancement of terrestrial integrated navigation system.

• Safety and Health at Work
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• 제12권1호
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• pp.10-19
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• 2021

Background: Traditional safety concept, which is called Safety-I, and its relevant methods and models have much contributed toward enhancing the safety of industrial systems. However, they have proved insufficient to be applied to complex socio-technical systems. As an alternative, Safety-II and resilience engineering have emerged and gained much attention for the last two decades. However, it seems that safety professionals have still difficulty understanding their fundamental concepts and methods. Accordingly, it is necessary to offer an introductory guide to them that helps safety professionals grasp them correctly in consideration of their current practices. Methods: This article firstly explains the limitations of Safety-I and how Safety-II can resolve them from the four points of view. Next, the core concepts of resilience engineering and Functional Resonance Analysis Method are described. Results: Workers' performance adjustment and performance variability due to it should be the basis for understanding human-related accidents in socio-technical systems. It should be acknowledged that successful and failed work performance have the same causes. However, they are not well considered in the traditional safety concept; in contrast, Safety-II and resilience engineering have conceptual bases and practical approaches to reflect them systematically. Conclusion: It is necessary to move from a find-and-fix and reactive approach to a proactive approach to safety management. Safety-II and resilience engineering give a set of useful concepts and methods for proactive safety management. However, if necessary, Safety-I methods need to be properly used for situations where they can still be useful as well.

• International Journal of Computer Science & Network Security
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• 제22권8호
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• pp.242-248
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• 2022

The article presents the analysis of modern methods of automatic comparison of original and unoriginal text to detect textual plagiarism. The study covers two types of plagiarism - literal, when plagiarists directly make exact copying of the text without changing anything, and intelligent, using more sophisticated techniques, which are harder to detect due to the text manipulation, like words and signs replacement. Standard techniques related to extrinsic detection are string-based, vector space and semantic-based. The first, most common and most successful target models for detecting literal plagiarism - N-gram and Vector Space are analyzed, and their advantages and disadvantages are evaluated. The most effective target models that allow detecting intelligent plagiarism, particularly identifying paraphrases by measuring the semantic similarity of short components of the text, are investigated. Models using neural network architecture and based on natural language sentence matching approaches such as Densely Interactive Inference Network (DIIN), Bilateral Multi-Perspective Matching (BiMPM) and Bidirectional Encoder Representations from Transformers (BERT) and its family of models are considered. The progress in improving plagiarism detection systems, techniques and related models is summarized. Relevant and urgent problems that remain unresolved in detecting intelligent plagiarism - effective recognition of unoriginal ideas and qualitatively paraphrased text - are outlined.

• Ocean Systems Engineering
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• 제12권2호
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• pp.143-157
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• 2022

In this study, the nominal wake field of a semi-displacement type high-speed vessel was computed at full scale by using CFD (Computational Fluid Dynamics) and GEOSIM-based approaches. A scale effect investigation on nominal wake field of benchmark Athena vessel was performed with two models which have different model lengths. The members of the model family have the same Fr number but different Re numbers. The spatial components of nominal wake field have been analyzed by considering the axial, radial and tangential velocities for models at different scales. A linear feature has been found for radial and tangential components while a nonlinear change has been obtained for axial velocity. Taylor wake fraction formulation was also computed by using the axial wake velocities and an extrapolation technique was carried out to get the nonlinear fit of nominal wake fraction. This provides not only to observe the change of nominal wake fraction versus scale ratios but also to estimate accurately the wake fraction at full-scale. Extrapolated full-scale nominal wake fractions by GEOSIM-based approach were compared with the full-scale CFD result, and a very good agreement was achieved. It can be noted that the GEOSIM-based extrapolation method can be applied for estimation of the nominal wake fraction of semi-displacement type high-speed vessels.

• Journal of Gastric Cancer
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• 제24권1호
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• pp.57-68
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• 2024

Reduced-port gastrectomy (RPG) includes all procedures derived from various efforts to minimize surgical invasiveness, with single-incision laparoscopic gastrectomy (SILG) being the ultimate reduced-port technique. However, there are challenges related to its feasibility, oncological validity, training, and education. This review describes the current issues and challenges, as well as the future prospects of RPG for gastric cancer. Gastrectomy, which started as an open surgery, has evolved into a laparoscopic surgery. With the advancements in laparoscopic technology, SILG has been used to minimize surgical scarring. However, owing to the technical difficulties of SILG, cases involving the addition of 1 trocar or needle grasper alongside the multichannel port have also been reported. Additionally, 3-port laparoscopic gastrectomy (3PLG) using only 3 trocars is also being performed. RPG, as a concept, includes a range of approaches such as SILG, 2-port laparoscopic gastrectomy, and 3PLG. These techniques aimed to reduce the number of ports or incisions required for laparoscopic gastrectomy. Despite technical difficulties, RPGs offer numerous advantages, including minimal invasiveness, excellent cosmetic outcomes, and the potential for improved postoperative recovery, such as reduced length of hospital stay and post-operative pain. It could be considered similar to conventional laparoscopic gastrectomy, and may not be oncologically inferior. Ongoing studies, such as the KLASS 12, are required to gain further insights.

• Corrosion Science and Technology
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• 제23권1호
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• pp.20-32
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• 2024

Metal corrosion in acidic environments is a major issue in various industrial applications. This study evaluates the 4-piperonylideneaminoantipyrine (PPDAA) corrosion inhibition efficiency for mild steel in a hydrochloric acid (HCl) solution. The weight loss method was used to determine the corrosion inhibition efficiency at different concentrations and immersion time periods. Results revealed that the highest inhibition efficiency (94.3%) was achieved at 5 mM concentration after 5 hours of immersion time. To inspect the surface morphology of the inhibitor film on the mild steel surface, scanning electron microscopy (SEM) was used before and after immersion in 1.0 M HCl. Density functional theory (DFT) calculations were performed to investigate the molecular structure and electronic properties of the inhibitor molecule to understand the corrosion inhibition mechanism. Theoretical results showed that the inhibitor molecule can adsorb onto the mild steel surface through its nitrogen and oxygen atoms, forming a protective layer that prevents HCl corrosive attack. These findings highlight the potential of PPDAA as an effective corrosion inhibitor for mild steel in HCl solution. Moreover, combining experimental and theoretical approaches provides insights into the mechanism of corrosion inhibition, which is essential for developing effective strategies to prevent metal corrosion in acidic environments.

• 방송공학회논문지
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• 제18권1호
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• pp.88-97
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• 2013

개인화된 추천을 제공하기 위한 협력 필터링은 추천 시스템에서 성공적으로 활용되어 온 기법이다. 그러나 협력 필터링이 주로 연구 및 적용된 분야들은 사용자로부터의 명시적 피드백이 존재하는 독립된 아이템들을 추천하는 것에 초점을 두고 있다. VOD 서비스 플랫폼에서 개인화된 TV 프로그램을 추천하기 위해서는 해당 도메인의 특성과 제한들을 고려하는 것이 필요하다. 본 논문에서는 TV 프로그램의 시리즈 속성을 이용하여, 선호를 판단하기 힘든 비명시적 피드백인 회별 프로그램 시청기록을 명시적이고 지속적인 프로그램 선호도로 변환하는 방법을 고안하였다. 데이터 수집과 최종 추천은 회별 프로그램 단위로 이루어지면서 협력 필터링 처리 단위는 프로그램으로 변경되어 TV 프로그램 VOD 추천 환경에 가장 적당한 형태로 협력 필터링을 변형 적용하였다. 실험 결과는 고안된 추천 시스템이 단순히 협력 필터링을 적용했을 때보다 높은 정확도와 더 적은 계산량을 가지는 것을 보여준다. 도메인 특화된 이러한 변형은 추천 시스템의 알고리즘 모듈로 구성되어 기존에 알려진 다양한 협력 필터링 기법과 결합하여 사용될 수 있다.

• 정보관리학회지
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• 제21권4호
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• pp.49-65
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• 2004

인터넷이 점차 실세상의 한 부분이 됨에 따라서 유용한 디지털도서관을 만드는 것이 우리사회에서 중요한 일이 되었다. 인터넷의 이전 세대에서는 주로 기술에 주안점을 두어 시스템을 개발하였다. 그러나 오늘날 논점은 지능적 디지털도서관을 통하여 유용하게 정보를 찾는 것으로 바뀌어가고 있다. 새로운 기술과 일상의 정보 요구사이에서 긴장은 풀리지 않고 있다는 지적이 계속 이어지고 있는데, 최근의 연구결과는 정보시스템 상에서 기술적 요소와 사회학적 요소 간에 균형이 필요하다는 것을 보여준다. 사회학적 요소에 대한 배려는 디지털도서관 시스템을 설치한 이후 계속 발전시켜나가는데 반드시 필요하다는 것을 보여준다. 본 연구는 새로운 DL 서비스가 요구되는 시대에 비 기술적 요소의 영향에 대한 중요성에 초점을 맞추고 있다. 첫 번째 세대의 DL 개발에 있어서 경험과 문건들이 체계적으로 검토 분석되었다. 분석결과 사회${\cdot}$기술적 접근방법이 새로운 서비스를 위해 절실히 필요하다는 명제를 제시하였다.

• 한국콘텐츠학회논문지
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• 제10권2호
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• pp.481-489
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• 2010

관계 추출 시스템의 중요성이 날로 부각되면서 이러한 시스템을 평가하기 위한 테스트 컬렉션의 구축이 중요한 과제로 떠오르고 있다. 본 논문에서는 반자동화된 처리 과정을 거쳐서 규모 있는 관계 추출용 테스트 컬렉션을 구축하는 프레임워크를 제안한다. 그리고 개발된 프레임워크를 이용하여 실제적으로 과학기술 문헌에 존재하는 기술용어 간 연관관계 추출 시스템의 성능 평가를 위한 테스트 컬렉션을 구축하고(관계유무 파악 및 관계분류 식별을 검사할 수 있는 1,707건의 문장 규모) 결과를 분석한다. 제안된 방법론은 정형화되고 시간이 많이 소요되는 문서분석 작업을 처리과정별로 자동화함으로써 구축에 들어가는 비용을 최소화할 수 있고, 시스템의 알고리즘을 기반으로 동작하기 때문에 구축자의 성향에 따른 편차를 줄이고 일관된 결과물을 얻을 수 있다. 또한 문헌 집합(과학기술 전 분야에 걸친 30,858,830건의 학술 데이터베이스) 및 용어 사전(16개 분야 253,603건 규모의 전문용어) 선정 시 특정 분야에 편중되지 않도록 노력함으로써 균형 잡히고 객관화된 테스트 컬렉션을 생성할 수 있다.