• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.32 no.2
• /
• pp.125-132
• /
• 2019

This paper presents a seismic reliability analysis method for an offshore wind turbine with a twisted tripod support structure under earthquake loading. A three dimensional dynamic finite element model is proposed to consider the nonlinearity of the ground-pile interactions and the geometrical characteristics of the twisted tripod support structure where out-of-plane displacement occurs even under in-plane lateral loadings. For the evaluation of seismic reliability, the failure probability was calculated for the maximum horizontal displacement of the pile head, which is calculated from time history analysis using artificial earthquakes for the design return periods. The application of the subset simulation method using the Markov Chain Monte Carlo(MCMC) sampling is proposed for efficient reliability analysis considering the limit state equation evaluation by the nonlinear time history analysis. The proposed method can be applied to the reliability evaluation and design criteria development of the offshore wind turbine with twisted tripod support structure in which two dimensional models and static analysis can not produce accurate results.

• The Korean Society of Law and Medicine
• /
• v.14 no.2
• /
• pp.119-142
• /
• 2013

It is not easy to regulate the amount of radiation used for the medical purpose as there usually is more good than harm to the patient's health and life caused by the medical exposure to the radiation. However, the rapid increase of the use of diagnostic radiation involves a high possibility of increasing the radiation hazard exposure. Therefore, it is imperative to implement effective regulations in order to secure the safety of diagnostic radiation. The one and only rule we currently have for the diagnostic radiation is "Medicine Act" with only one clause dedicated to regulate the safety management that does not include any rules for the medical radiation. A set of inclusive rules for the whole medical radiation inclusive of diagnostic radiation and therapeutic radiation need to be based on the "Medicine Act" rather than "Nuclear Safety Act" in order to protect the medical professionals, patients and the guardians of patients from the hazards of diagnostic and/or therapeutic radiation that was not used the purpose of medical treatment. If there is an administrative measure to be imposed to secure the safety of diagnostic radiation, it is considered as exertion of governmental authority of administrative agency. There must be clear and realistic legal guidelines for in-fringe on people's interests. The administrative measures for the safety management of the diagnostic radiation must be clearly and specifically based on the law and the detailed standards for the administrative measures must be dele-gated by the presidential decree or departmental ordinance. Accordingly, the restrictions imposed by the administrative measures to the "Safety Inspection Institute of Radiation along with Radiation Exposure Measuring Institutes" should have clear legal basis as well and the detailed standards for the administrative measures should be regulated by the Ministry of Health and Welfare decree instead of the notification by the Director of Korean Centers for Disease Control and Prevention. While securing the safety of radiation on one side, careful review and up-grade on our legal system for the safety management of the diagnostic radiation is required on the other side to guarantee the legality, interest balance and reliability of the administrative measures.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.13 no.1
• /
• pp.1-10
• /
• 1976

A 2-out of-3 coincidence circuit and a discriminator to be used in the safely systems in nuclear reactors are described and analyzed in detail. The expressions for the reliability and the spurious scram reiliability of 1.out of-m coincidence logic in general are derived and the optimum value of 1 is assessed. The coincidence circuit is designed by making use of the pulse-summing method and is very simple in principle. The discriminator has good linearity in in the whole discrimination range and good threshold stability.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.62 no.3
• /
• pp.117-126
• /
• 2013

This paper is written for the development and application of boiler furnace pressure control algorithm and distributed control system of coal-fired power plant by the steps of design, coding, simulation test, site installation and site commissioning test. The control algorithms were designed in the shape of cascade control for two parts of furnace pressure control and induced draft fan pitch blade by standard function blocks. This control algorithms were coded to the control programs of distributed control systems. The simulator for coal-fired power plant was used in the test step and automatic control, sequence control and emergency stop tests were performed successfully like the tests of the actual power plant. The reliability was obtained enough to be installed at the actual power plant and all of distributed control systems had been installed at power plant and all signals were connected mutually. Tests for reliability and safety of plant operation were completed successfully and power plant is being operated commercially. It is expected that the project result will contribute to the safe operation of domestic new and retrofit power plants, the self-reliance of coal-fired power plant control technique and overseas business for power plant.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.22 no.4
• /
• pp.501-508
• /
• 2019

In this paper, a study on a wireless check-up method of test equipment for captive flight test(CFT) was conducted. For CFT, test equipment is mounted on a POD, and check-up is carried on the test equipment's. For check-up the POD wirelessly, battery, power distribution unit, wireless communication devices were designed within the POD, and a check-up device is designed outside of the POD. Once the external check-up device sends a 'start signal' to the POD, it performs the overall check-up procedures and transmits the 'end signal' to the external check-up device. Detailed check-up results are stored in an internal storage device, and are possible to read from external check-up device if necessary, thereby improving the reliability of the wireless check-up. By implementing and applying these wireless check-up system, the reliability of the check-up was enhanced by dynamical and movable check-up, and safety is guaranteed as the check-up was carried without access to the aircraft.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.62 no.1
• /
• pp.36-44
• /
• 2013

This paper is written for the development and application of boiler fuel control algorithm and distributed control system of coal-fired power plant by the steps of design, coding, simulation test, site installation and site commissioning test. Fuel control algorithm has the upper algorithm and it is boiler master control algorithm that controls the fuel, feed water, air by generation output demand. Generation output demand by power load influences fuel control. Because fuel can not be supplied fast to the furnace of boiler, fuel control algorithm was designed adequately to control the steam temperature and to prevent the explosion of boiler. This control algorithms were coded to the control programs of distributed control systems which were developed domestically for the first time. Simulator for coal-fired power plant was used in the test step. After all of distributed control systems were connected to the simulator, the tests of the actual power plant were performed successfully. The reliability was obtained enough to be installed at the actual power plant and all of distributed control systems had been installed at power plant and all signals were connected mutually. Tests for reliability and safety of plant operation were completed successfully and power plant is being operated commercially. It is expected that the project result will contribute to the safe operation of domestic new and retrofit power plants, the self-reliance of coal-fired power plant control technique and overseas business for power plant.

• Proceedings of the SAREK Conference
• /
• 2008.06a
• /
• pp.3-9
• /
• 2008

Recently, the plant industries are being activated and plant control systems use various technologies. Because the optimized design for the plants is very important for the reducing of operation and maintenance costs, automatic control systems become more important. Plant control systems consist of the master controller, the plant networks, the programming environment for engineering, monitoring software and the field devices. The control systems should have reliability, availability and safety. Modular architecture of hardware and software makes flexible configuration of the control systems. Each component should have diagnostic functions. It follows industrial standards and makes open systems. Open systems increase accessibility against the data which is distributed in the plants. The controllers including processor and communication modules use the up-to-date technology. They have real time and fault tolerant function by duplicating processors or networks. It also enables to make the distributed control systems. The distributed architecture makes more scalable main control system. Automatic control systems can be operated with better performance. In this paper, we analyzed the requirements of the seawater desalination plants and made some consideration facts for developing the optimized controller. Also we described the design concept of the main controller, which consists of several modules. We should validate and complement the design for the reliability and better performance.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2004.04a
• /
• pp.479-486
• /
• 2004

The purpose of this study is to practical use with increase safety, usablility and economical. In this study, the property of fatigue behavior was tested by comparing reinforced concrete and steel fiber reinforced concrete. The basic test, the static test and fatigue test were used as the research methods. Basic on the test, the material compressive strength test and split tensile strength test ware conducted 7 days and 28 days after the concrete was poured. In the static test, there ware four types of experimental variables of the steel fiber mixing ratio : 0.00%, 0.75%, 1.00%, and 1.25%. The ultimate load initial diagonal tension crack, and initial load of flexural cracking were all observed by static test. A methodology for the probabilistic assement of steel fiber reinforced concrete(SFRC) which takes into account material variability, confinement model uncertainty and the uncertainty in local and globa failure criteria is applied for the derivation of vulnerability curves for the serviceability and ultimate limit states, the reliability of SFRC using the proposed practical linear limit state model is evaluated by using the AFOSM(Advanced First Order Second Moment) method and MCS(monte-Calrosimulation) method.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.19 no.2
• /
• pp.156-169
• /
• 2009

In this study, the authors introduced DASH (Disabilities of the arm, shoulder, and hand), which had been developed for evaluating the functional impairment in the movement of upper extremities in regular daily activities, work ability and sports/performing arts ability. It is an ergonomic risk assessment tool used for industrial workers and also a disability measurement tool for upper extremity disorders arising from musculoskeletal disorders and symptom. This study intended to examine the applicability of DASH in occupational health field. Firstly, DASH development process and composition were reviewed through The DASH outcome measure user's manual and early articles. Secondly, reliability, validity, and responsiveness of the DASH in various languages at the application stage as well as its reliability and validity at the early stage of development were investigated. Thirdly, focusing on the application of DASH to clinical cases, workers with musculoskeletal symptoms, healthy workers, workers with other diseases, and general population were discussed besides workers with major musculoskeletal disorders. Lastly, DASH questionnaire was examined for its potential as a reference for assessing the functional impairment in the movement of upper extremities of workers with musculoskeletal symptoms in industrial workers in Korea.

• Journal of Korean Clinical Nursing Research
• /
• v.21 no.3
• /
• pp.401-411
• /
• 2015

Purpose: This study was performed to develop a valid and reliable Korean Patient Classification System for Critical Care Nurses (KPCSC). Methods: Tertiary and general hospitals with various levels of ICU nurse staffing were included. To verify interrater reliability, data collectors and staff nurses of 15 ICUs in 11 hospitals classified 262 patients. To verify construct validity, the staff nurses classified 457 patients according to KPCSC comparing difference by medical department and type of stay in ICU. For conversion index, 195 patients from 10 ICUs in 7 hospitals were classified and nursing time was measured by 174 nurses, 7 head nurses, 18 charge nurses, 37 nurse aids and 1 secretary. Results: The developed KPCSC has 11 categories, 82 nursing activities and 115 criterias. Reliability was found to have high agreement (r=.96). Construct validity was verified by comparing differences in medical department and type of stay in ICU. According to scores, four groups in the KPCSC were identified. One score on the KPCSC indicates 6.12 minutes of nursing time. Conclusion: The findings show that the KPCSC can be used to measure new and complex nursing demands including rehabilitation and the safety of ICU patients.