• Nuclear Engineering and Technology
• /
• 제49권8호
• /
• pp.1696-1710
• /
• 2017

An improved Reactor Regulating System (RRS) logic architecture, which is combined with genetic algorithm (GA), is implemented in this work. It is devised to provide an optimal solution to the current RRS. The current system works desirably and has contributed to safe and stable nuclear power plant operation. However, during the ascent and descent section of the reactor power, the RRS output reveals a relatively high steady-state error, and the output also carries a considerable level of overshoot. In an attempt to consolidate conservatism and minimize the error, this work proposes to apply GA to RRS and suggests reconfiguring the system. Prior to the use of GA, reverse engineering is implemented to build a Simulink-based RRS model. Reengineering is followed to produce a newly configured RRS to generate an output that has a reduced steady-state error and diminished overshoot level. A full-scope APR1400 simulator is used to examine the dynamic behaviors of RRS and to build the RRS Simulink model.

• Safety and Health at Work
• /
• 제11권4호
• /
• pp.533-536
• /
• 2020

Strengthening of the health system is a safety imperative, especially in a crisis as caused by the ongoing COVID-19 pandemic. While there is a need for enhancing the number and skill sets of the public health professionals, especially the frontline workers, it will be prudent to use the digital health technologies, including artificial intelligence, in enhancing the capacity of the healthcare professional education and delivery. However, it has to be ensured that an ethical and safe approach is adopted to develop and use digital health technology and, ethically appropriate training is imparted, to enhance the capacity of the human resources for health, leading to an overall health system strengthening.

• 정보보호학회논문지
• /
• 제33권6호
• /
• pp.1001-1020
• /
• 2023

코로나19 이후로 재택근무의 대폭 활성화로 기업 네트워크의 내부와 외부의 경계가 모호해졌다. 이로 인해 전통적인 경계형 보안으로는 기업의 업무 생산성이 정체되고 정보 유출 등의 위험 관리가 어려워졌다. 제로 트러스트 아키텍처 모델이 등장하였으나 기업별로 다양하게 구성된 IT 환경에 적용하기에는 어려움이 있다. 이에 재택근무 시스템 구성을 예시로 온-프레미스, 클라우드 및 망 분리 등의 네트워크 환경에서도 제로 트러스트 모델을 적용할 수 있는 구성과 방법론을 제시하였다. 이를 통해 사이버 위협에 능동적으로 대응하는 지능형 체계인 제로 트러스트 아키텍처를 적용하려는 기업에 가이드를 제공하여 안전하면서도 편리한 사이버 환경 조성에 기여 하고자 한다.

• 한국안전학회지
• /
• 제15권4호
• /
• pp.101-111
• /
• 2000

In order to introduce P.S.M. system adequate to domestic construction first, many cases similar to advanced foreign P.S.M. system have been collected and compared to the domestic situation. Then, the current safety management status of bridges, subways, apartment and office building construction are investigated while visiting interview, using questionnaire at site have being done. The potential hazard and measurement have been investigated for each kind of works, and the domestic introducing method of P.S.M. system is analyzed with expert discussion. In order to represent how to make out P.S.M. plan, the questionnaire is made out using each five place for bridge, subways, apartment and office building. As the weight factor for potential hazard of each work obtained from more than forty site places, is produced and shown. Also, a direction the recommendation is suggested to improve tool in each construction site with work schedule. It is thought that proposed schedule contributed to keeping in safe business administration of each company in decreasing many effort at the construction site.

• 한국치위생학회지
• /
• 제19권6호
• /
• pp.907-918
• /
• 2019

Objectives: This qualitative research was conducted to clearly find and clinically understand dental hygienists' work experience in order to lay the legal foundation for their work range and safe execution. Methods: From March 1 to April 30, 2019, seven study participants were selected and participated in-depth interviews. Phenomenological research methodology was applied for intensive analysis. Results: They performed jobs that required no professionalism, such as dental assistance, except for scaling. Dental hygienists, nurses' aids, and dental technicians performed the same jobs regardless of difficulty level and legal work range. Dental hygienists failed to accurately recognize their legal work range. Since there was the wide gap between their legal work range and actual work range, it was necessary to expand the work range in line with actual conditions. Conclusions: Given the results, it is necessary to conduct in-depth discussions within the dental circle to make dental hygienists' work execution in line with reality by improving and discussing a legal system for job assignment and expansion of workers. Therefore, it is required to form a plan for the many jobs dental hygienists executed in a clinical setting.

• 한국정보과학회논문지:소프트웨어및응용
• /
• 제32권12호
• /
• pp.1238-1246
• /
• 2005

본 논문은 이종의 시스템에서 안전한 데이타 전송을 만족하는 웹 보안 모듈을 구현한 내용에 대해서 언급한다. 웹 시스템을 통해 사용자에게 사용의 편리함과 많은 정보를 주었고 웹 서비스 사업이 활발해졌으나 웹 시스템의 한계로 인해 보안상의 취약점인 데이타 유출에 의한 손실을 가져오게 되었다. 이에 많은 대응들이 있지만 좀더 효과적이고 편리한 데이타 보안을 위해 서버 클라이언트 보안 모듈을 구현하였다. 제안한 보안 모듈은 크게 두 개의 모듈로 구현된다. 하나는 웹 서버에서 동작하는 서버 보안 모듈이고, 다른 하나는 클라이언트에서 동작하는 클라이언트 보안 모듈이다. 본 논문에서 제안하는 보안 구조는 클라이언트와 서버간의 간단한 모듈의 설치로 안전한 데이타 전송을 보장한다. 속도에 민감한 웹 서버와 브라우저 사이의 빠른 암호화 통신을 위한 대칭 암호화 방식인 Triple-DES를 사용하였으며 키 관리 문제를 해결하기 위한 Diffie-Hellman 키(key) 교환 알고리즘을 적용하였다. 이렇게 함으로써 대칭 암호화에서 발생하는 키 분배 및 관리문제와 속도문제를 해결했다. 또한 DH방식의 알고리즘을 사용함으로써 서버와 클라이언트 사이의 안전한 데이타 보안을 위한 인증문제를 해결하였다.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2005년도 제24회 춘계학술대회논문집
• /
• pp.92-95
• /
• 2005

본 연구는 기존의 폭발볼트와는 달리 작동에 필요한 전원의 공급 없이 수행하면서, 또한 지연기능까지 포함한 비전기식 지연형 폭발볼트에 관한 것이다. 즉 비전기식 작동방법을 이용하여 전원 공급 장치를 없앨 수 있기 때문에 분리장치의 소형화가 가능해졌고, 이를 위하여 기존 폭발볼트의 작동 메카니즘과는 다른 새로운 개념의 메카니즘을 적용하였고, 또한 지연기능을 추가하기 위하여 작동메카니즘 개발과 별도로 지연장치를 개발하였다. 전원을 사용하지 않고 작동하는 착화장치를 설계하기 위하여 폭발볼트가 결합된 비행체에서 발생하는 공기의 저항력을 이용하였다. 고속으로 비행하는 발사체의 속도를 줄이고 안전한 착륙을 위한 낙하 시스템의 설계에 고려될 수 있는 장치라고 생각된다.

• 국제학술발표논문집
• /
• The 3th International Conference on Construction Engineering and Project Management
• /
• pp.218-223
• /
• 2009

During the process of excavation for substructures of buildings, precise and constant measurements of retaining wall displacement is crucial for construction to be complete and safe. Currently an inclinometer is used to measure displacement around the perimeter of an excavation site. The existing inclinometer system requires an instrument to be placed inside pre-bored holes for each measurement with an typical interval of two weeks. This makes it difficult to obtain continuous displacement data, especially during a critical time such as rainy season in summer. Also, the existing inclinometer is placed at certain distance away from the retaining wall system itself. Thus, exact measurement of retaining wall movement is compromised because of the distance between the retaining wall and the inclinometer. This paper presents the development of wireless inclinometer system for the displacement measurement of retaining walls by being attached directly to the retaining wall. The result of the application of the developed systems are provided with advanced ubiquitous sensor network (USN) system features. The USN technique incorporated into the system enables users to monitor movement data from wherever possible and convenient such as construction manager's office on site or any other places connected through internet. The research work presented in this paper will provide a basis to save construction time and cost by preventing safe-related unexpected delay of construction due to the failure or collapse of retaining walls.

• 한국안전학회지
• /
• 제28권5호
• /
• pp.27-34
• /
• 2013

Almost accidents in construction sites are occurred by unsafe work conditions and failure making safe environment. As recent construction projects become more complex, various and diversified, So the potential of construction-related accidents is increased as well. Comparing the frequency of construction-related accidents in large-sized construction sites, small-sized construction sites are more vulnerable because of lack of workforce and less effective technology system. Furthermore, the absence of safety committee, poor financial condition leads to lack of safety education, installation of safety facilities, and provision of individual protective equipment, which indicates difficulties handling even basic safety management. Therefore, in order to lower the hazard rate at small-Sized construction sites, it is necessary to proceed with more structural and thorough actions for preventing accidents. In other words, it is necessary to analyze the causes of the accidents at small-sized construction sites, set criteria for safety management, and suggest safety management items according to work classification by evaluating the relative importance of the items.

• 청정기술
• /
• 제26권4호
• /
• pp.279-285
• /
• 2020

Laboratories and industrial processes typically involve the use of flammable substances. An important property used to estimate fire and explosion risk for a flammable liquid is the flash point. In this study, flash point data at 101.3 kPa were determined using a SETA closed cup flash point tester on the following solvent mixtures: {2,2,4-trimethylpentane + methylcyclohexane}, {2,2,4-trimethylpentane + ethylbenzene}, and {2,2,4-trimethylpentane + p-xylene}. The purpose of this work is to obtain flash point data for binary mixtures of 2,2,4-trimethylpentane with three hydrocarbons (methylcyclohexane, ethylbenzene, and p-xylene), which are representative compounds of the main aromatic hydrocarbon fractions of petroleum. The measured flash points are compared with the predicted values calculated using the GE models' activity coefficient patterns: the Wilson, the Non-Random Two-Liquid (NRTL), and the UNIversal QUAsiChemical (UNIQUAC) models. The non-ideality of the mixture is also considered. The average absolute deviation between the predicted and measured lower flash point s is less than 1.99 K, except when Raoult's law is calculated. In addition, the minimum flash point behavior is not observed in any of the three binary systems. This work's predicted results can be applied to design safe petrochemical processes, such as identifying safe storage conditions for non-ideal solutions containing volatile components.