• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1392-1395
• /
• 2004

In order to successfully develop attitude and orbit control subsystem(AOCS), AOCS engineer performs hardware selection, controller design and analysis, control logic and interface verification on electrical test bed, integrated system test, polarity test, and finally verification on orbit after launching. Attitude and orbit control subsystem for KOMPSAT-2 consists of standby mode, sun mode, maneuver mode, science mode, and power safe mode to stabilize and to control the spacecraft for performing the mission. The sun mode is usually divided into sun point submode, earth search submode and safe hold submode. The maneuver mode is divided into attitude hold submode and ${\triangle}$ V submode, while the science mode divided into science coarse submode and science fine submode. Moreover, it is added to back-up mode which uses wheels as an actuator for sun mode and maneuver mode. In this paper, we describe the controller design process and the performance of the design results with respect to the sun mode and the maneuver mode based on thrusters as an actuator using on flexible model.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.46-49
• /
• 2004

The spider of a drum washing machine receives the repeated fatigue loadings during laundering. Although the spider is designed statically safely, it often happens fatigue failure. Therefore it requires the safe design for fatigue and needs the prediction of quantitative fatigue life. The S-N diagram for a spider material is developed by fatigue test and statistical analysis. The stresses are measured directly from strain gages on the spider. To predict the fatigue life of spider, the rainflow counting method and Miner's rule are used. The data for fatigue life are analyzed statistically. From these data, reliability estimation for fatigue life can be done and also, equivalent fatigue life can be obtained. It will be applied to make and improve to a short period for design and prototype test.

• Journal of Korean Public Health Nursing
• /
• v.24 no.2
• /
• pp.258-269
• /
• 2010

Purpose: This study investigated the effectiveness of AIDS education on knowledge, prejudice, susceptibility, severity, and intention of safe sex behavior among university students. Methods: This study was conducted from March, 2008 to May, 2008. The research design was a non-equivalent control group pre-post test. Participants 78 university students (control group) and 89 university students (experimental group). For the latter, AIDS education was provided once weekly for 1 h for 4 weeks. The educational program included understanding of sexuality, facts of AIDS, life stories of patients with AIDS, and safe sex behavior. The differences between two groups after education were analyzed by independent t-test. Results: The experimental group had significantly higher scores for knowledge, prejudice, susceptibility, and intention of safe sex behavior compared to the control group. However, no significant difference was found for severity between two groups. Conclusion: AIDS education can be effective in improving knowledge, prejudice, susceptibility, and intention of safe sex behavior, and is recommended as an effective AIDS education for university students.

• Nuclear Engineering and Technology
• /
• v.53 no.11
• /
• pp.3517-3527
• /
• 2021

New 80-MW (electric) ultra-long-life sodium cooled fast reactor core having inherent safety characteristics is designed with heterogeneous fuel assemblies comprised of driver and blanket fuel rods. Several options using upper sodium plenum and SSFZ (Special Sodium Flowing Zone) for reducing sodium void reactivity are neutronically analyzed in this core concept in order to improve the inherent safety of the core. The SSFZ allowing the coolant flow from the peripheral fuel assemblies increases the neutron leakage under coolant expansion or voiding. The Monte Carlo calculations were used to design the cores and analyze their physics characteristics with heterogeneous models. The results of the design and analyses show that the final core design option has a small burnup reactivity swing of 618 pcm over ~54 EFPYs cycle length and a very small sodium void worth of ~35pcm at EOC (End of Cycle), which leads to the satisfaction of all the conditions for inherent safety with large margin based on the quasi-static reactivity balance analysis under ATWS (Anticipated Transient Without Scram).

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.36 no.10
• /
• pp.1181-1187
• /
• 2012

For the fatigue design of aircraft landing gear, the safe-life approach is applied. Structural defects such as cracks or detrimental deformations should not occur under the fatigue load spectrum depicting the entire lifetime usage of the aircraft. In the design phase, the fatigue life of the landing gear is estimated analytically by adopting the stress-based approach because the fatigue of aircraft landing gear is generally high-cycle fatigue. This utilizes S-N curves that are factored to produce design curves that account for the scatter and surface finish of the material. In the test and evaluation phases, a fatigue test should be conducted for full-scale landing gear to substantiate the fatigue design requirement in the end. In this study, the procedure for the fatigue test and evaluation of aircraft landing gear is presented with real application cases.

• International Journal of High-Rise Buildings
• /
• v.1 no.4
• /
• pp.255-269
• /
• 2012

Tall buildings' implementation has often lacked urban design and architectural guidance. There are many examples of tall buildings that have been inappropriately located, designed, and built, and consequently dissatisfaction with high-rise development is wide-spread. This paper attempts to provide extensive urban and architectural guidelines in order to manage cityscape and to ensure safe and healthy living. Through recommendations on design and layout of tall buildings and open spaces the guidelines seek enhancing the visual experience, improving the microclimate conditions, and fostering active social life. These guidelines help in providing enjoyable urban experiences through the examination of spatial relationships, human scale, genius loci, perceptual characteristics, local identity, built heritage, economic activities, and social life.

• Korean Institute of Interior Design Journal
• /
• v.23 no.6
• /
• pp.150-159
• /
• 2014

Recently, violent crimes against the socially disadvantaged have become more frequent and became serious social issues. In addition, compared to the past, the crime methods have become more diverse and intricate, which results in larger damages. For those reasons, the public are increasingly concerned about crimes and it is detrimental to the quality of life in general. Currently, safety in alleys and other residential spaces is protected only by mechanical and managerial functions such as CCTV and police patrol. Safe environment from crimes can be achieved only if there are environmental and spatial plans such as CPTED (Crime Prevention through Environmental Design) principles. The purpose of this study is to propose a direction for spatial planning that can prevent crimes through environmental elements, by researching the spatial planning and current status of alleys and residential spaces from the viewpoint of CPTED. To do so, first, a review checklist was created based on five principles of CPTED and field surveys were conducted on the northern districts of Busan with high crime rates. Second, the problems were analyzed through the field surveys and checklist was classified based on five principles of CPTED to propose improvements for each item. Also, a computer graphic simulation was used to suggest a design proposal. We expect that the application of the basic environmental design principles and guidelines for CPTED will have the effect of creating crime-free and safe spaces in alleys and residential environment.

• Journal of Ocean Engineering and Technology
• /
• v.13 no.3 s.33
• /
• pp.29-35
• /
• 1999

At the design of Mark III membrane type LNG tank, an analytical and experimental approach on the fatigue strengths of membrane and its welds are very important in order to assist designers and surveyors. In this study, fatigue tests of lap weld of Mark III membrane type LNG tank were carried out and cumulative damage factor was calculated in order to estimate the fatigue life by probability density function and rule methods. It contained the following tests and reviews : 1) The fatigue tests of lap weld of stainless steel according to statistical testing method recommended by JSME, 2)Preparation of S-N curve for lap welds considering the statistical properties of the results of fatigue tests. 3) Procedure for estimating the initiation life of fatigue crack of lap welds under variable loads by the rule lf classification society and probability density function, 4) Guideline for inspection of lap welds fo membrane type LNG tank.

• Journal of the Korea Safety Management & Science
• /
• v.1 no.1
• /
• pp.29-39
• /
• 1999

Human sensibility ergonomics is the technique that qualities man's sensibility, measures and evaluates it Quantitatively and makes man's life comfortable, safe and delightful by applying it to products or environmental projects. This study consider the sensibility factor of Sasang constitutional medicine, five elemental properties, and Biorhythm in terms of human sensibility ergonomics. And this study measure reaction-time dependent on a temperament or a state and evaluate the differences of reaction-times objectively with the comparison and analysis using the ANOVA. We can harness it for job design.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.5A
• /
• pp.389-396
• /
• 2005

In this paper, we design AVTMRWFSV(All Voting Triple Modular Redundancy With Fail-Safe Voter) System with a fail-safe output voter architecture and analyze RAMS(Reliability, Availability, Maintainability, Safety) as system failure rate. This system is compared with AVTMR system for RAMS(Reliability, Availability, Maintainability, Safety) with Markov modeling, and we can see that the system safety of AVTMRWFSV is more profitable than that of AVTMR. The dependability of AVTMRWFSV system is higher than that of AVTMR. Especially, safety is very profitable. So, this kind of system can be applied to embedded communication system and life critical systems - railway, airplane, ship, nuclear control system and so on.