• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.23 no.4
• /
• pp.102-108
• /
• 2015

According to various researches, one of main causes of flight accidents is influence of human factors. It is important to collect and analyze event data in advance to minimize and prevent human errors by developing safety checklist. As a result international aviation industry developed Flight Operations Quality Assurance for commercial airliners, and, upon its proven effectiveness, it is now highly recommended to adopt for helicopter operations. Consequently, S government organization instituted Helicopter Flight Operations Quality Assurance system in 2012. Hence, this study conducted regression analysis of S organization's flight event frequency and applied ICAO SMS Matrix to categorize the severity of the events according to international standards. Based on the analysis, this research derived fundamental checklist factors for helicopter, which can be a proactive measure for safe operation.

• Journal of Korean Society of Transportation
• /
• v.14 no.2
• /
• pp.119-136
• /
• 1996

The evaluation of risk level or possibility of traffic accidents is a fundamental task in reducing the dangers associated with current transportation system. However, due to the lack of data and basic researches for identifying such factors, evaluations so far have been undertaken by only the experts who can use their judgements well in this regard. Here comes the motivation this thesis to evaluate such risk level more or less in an automatic manner. The purpose of this thesis is to test the fuzzy-logic theory in evaluating the risk level of traffic accidents. In modeling the process of expert's logical inference of risk level determination, only the geometric features have been considered for the simplicity of the modeling. They are the visibility of road surface, horizontal alignment, vertical grade, diverging point, and the location of pedestrain crossing. At the same time, among some inference methods, fuzzy composition inference method has been employed as a back-bone inference mechanism. In calibration, the proposed model used four sites' data. After that, using calibrated model, six sites' risk levels have been identified. The results of the six sites' outcomes were quite similar to those of real world other than some errors caused by the enforcement of the model's output. But it seems that this kind of errors can be overcome in the future if some other factors such as driver characteristics, traffic environment, and traffic control conditions have been considered. Futhermore, the application of site's specific time series data would produce better results.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2004.05b
• /
• pp.429-433
• /
• 2004

According to researchers, the influential factors of scouring are generally divided into three factors: the flow conditions, the type and position of structures, and the characteristics of bed materials. In addition, scouring is affected by the 3-dimensional turbulent boundaries, the unsteady flow, the movement of sediment in the scour-hole area, the approach flow velocity and depth, the width of bridge foundation/pier, and the particle size of bed materials. However, it is difficult to estimate the scour depth near bridge piers when all conditions are factored in at once. Therefore, for reasonably accurate estimates of scour depth, it is essential to consider sufficiently the flow force and resisting force for scour. That is, to determine the shear stress concerning the bed material distribution is needed. In this study, the experiments were performed under the condition of a steady state of flow. As a result, scouring occurred at velocity ratios of 0.476,$(V/V_c=0.476)$, and the scour depth was increased linearly as the velocity ratio increased. in addition, the average values of shear stress ratio at zero scouring depth in both rectangular and circular piers were approximately 7$(\tau_c/\tau_{approach})$ and in the case for same size bed particle material. The results of this study can be used for the fundamental material for estimating the scour depth of bed materials.

• Journal of the Korean Society of School Health
• /
• v.9 no.2
• /
• pp.223-237
• /
• 1996

This study was conducted in order to contribute to female student health by providing fundamental data for health instruction and health counsel. The purpose of this study is to determine the frequency of PMS by a menstrual distress questionnaire, and determine sex-identity factors related to PMS. The data were collected by a questionaire conducted from December 1,1995 to December 20, 1995. The subjects of research were 1,102 high school students in Seoul. The data analyzed was done using the SPSS PC+, and the results were as follows; 1. The perceived subjective symptoms were clusted behavioral change, negative affects, pain, impaired concentration, water retention and autonomic reactions. The most common symtoms during the period of 2 to 10 days before menses were vaginal discharge(79%), back pain(70.4%), nervous tension(60.8%), fatigue(56.2%), abdominal bloating(54.5%), mood change(52.8), pelvic pain(46.8%), resistance to study(45.9) and talking(43.3). 2. There was a significant correlation between the clusters symptoms; negative affects and behavioral changes(r=.9326, p=.000), behavioral changes and impaired concentration (r=.8572, p=.000), negative affects and impaired concentration(r=.8411, p=.000) and autonomic reaction and pain(r=.7267, p=.000). 3. Sex-identity factors were related to PMS ; perception of the female(F=5.1811, p=.006) and pregnancy concerns (T=3.54, p=.000).

• Journal of Powder Materials
• /
• v.23 no.2
• /
• pp.149-169
• /
• 2016

Additive manufacturing (AM) is defined as the manufacture of three-dimensional tangible products by additively consolidating two-dimensional patterns layer by layer. In this review, we introduce four fundamental conceptual pillars that support AM technology: the bottom-up manufacturing factor, computer-aided manufacturing factor, distributed manufacturing factor, and eliminated manufacturing factor. All the conceptual factors work together; however, business strategy and technology optimization will vary according to the main factor that we emphasize. In parallel to the manufacturing paradigm shift toward mass personalization, manufacturing industrial ecology evolves to achieve competitiveness in economics of scope. AM technology is indeed a potent candidate manufacturing technology for satisfying volatile and customized markets. From the viewpoint of the innovation technology adoption cycle, various pros and cons of AM technology themselves prove that it is an innovative technology, in particular a disruptive innovation in manufacturing technology, as powder technology was when ingot metallurgy was dominant. Chasms related to the AM technology adoption cycle and efforts to cross the chasms are considered.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.18 no.2
• /
• pp.137-143
• /
• 2006

This study has been conducted to quantify the emissions of Volatile Organic Compounds (VOCs) in a conference room. The carpet has emitted a variety of VOCs, but in this study, 2 VOCs compounds have been considered: Ethylbenzene and 1, 2, 3-Trimethylbenzene. In this study, a three dimensional numerical analysis has been carried out to investigate the emission and behavior characteristics of Ethylbenzene and 1, 2, 3-Trimethylbenzene emitted from the carpet in the conference room. The mass diffusion coefficient and the initial concentrations of VOCs in the carpet have been obtained from experimental data with non-linear regression. It has been found that the concentrations and emission factors of VOCs have exponentially decayed with time and that the concentration gradients and emission factors of VOCs are different from each other for various components. This study may supply fundamental understandings for the emission and behavior characteristics of VOCs.

• Journal of The Korea Institute of Healthcare Architecture
• /
• v.17 no.1
• /
• pp.15-22
• /
• 2011

Nowadays, a proportion of healthcare service for the elderly has been improved due to the factors, such as a prolonged life expectancy, a growth of aging population and a change of member of family. For these factors, it is necessary for the elderly to receive treatment for multidisciplinary diseases, associated with psychological care of sociological concept. It is quite difficult in an acute-care hospital to accommodate the elderly patient because of the fact that an acute-care hospital is required to maintain a high level of medical care and technical standard. That is why specialized medical service is needed for the elderly. In the case of Germany, they are at the stage of the change from large scale facilities to specialized facilities applying the integrated concept. This paper addresses the medical environmental factor and distinction of medical facilities for the elderly through survey and analysis relating to all change in Germany. Therefore, it aims to suggest a fundamental resource for architectural planning and network of medical facilities for the elderly.

• Korean Institute of Interior Design Journal
• /
• v.15 no.2 s.55
• /
• pp.127-137
• /
• 2006

In the viewing of public performance arts, it needs to make space construction appropriate for performance purposes, because the section type has an effect on audience's inspection. Therefore, this study researches the intentional characteristics and comprehends the relationship between correlation factors to influence on section type of audience space in performance facilities. In addition to, this study comes under fundamental research to propose the course of standard plan, accord with diverse requirement, in the special performance facilities which will be built up. The results as following; 1) The factors that influence the section type of the audience's space in performing facilities are divided as two elements. The first element is construction of space, viewing environment, and the second element is visual characteristic, and acoustic characteristic. 2) The section type are classified as six types, A-type(Flated type), B-type(Sloped type), C-type(Gabled type), D-type(Arched type), E-type(Reverse arched type), and F-type(Reverse sloped type). 3) Characteristics are deduced by the section type, construction of space and viewing environment are restricted by the characteristics of the section type.

• KIEAE Journal
• /
• v.3 no.3
• /
• pp.27-34
• /
• 2003

As a result of supply-oriented housing policy of Korea since the 1960s, the number of apartment housing units has increased up to six million as of the end of 2001 that is 55% of total housing units. Although the needs of placid living environment increases according to the enhancement of residents' living standard, most of construction firms as apartment suppliers plan and design apartment buildings to maximize the profit and give rise the residents' petitions and troubles about floor impact noise. In consequence, the floor impact noise becomes one of principal problems of living environment, and the government placed the obligation of installing the noise isolation materials between upper and lower floors in 2001 and controlling the floor impact noise lower than 60dB from the middle of 2004. In other to provide the fundamental research data to enhance the reduction performance of floor impact sound, in this paper, the factors that influence on the floor impact noise are derived from the survey of many research papers and the performance of various materials used as noise reduction objects are compared and surveyed with the factors in the experiments in field and laboratory.

• Fashion & Textile Research Journal
• /
• v.8 no.3
• /
• pp.310-316
• /
• 2006

Fitness of clothes becomes a major concern in apparel industry. But male sports athletes had difficulties to buy ready-made clothes of good fit. Because ready-made clothes manufactured in companies are produced accordingly to the general person's body types. To solve this problem, it is necessary to classify athletes' upper body into several kinds of somatotypes. The purpose of this study was to classify upper body types of male sports athletes based on the analysis of their upper body types and to provide fundamental data on the development of ready-to-wear clothing appropriate for the upper body types. The subjects for anthropometric measurement were 189 male sports athletes of 20 to 29 year-old. The result of factor analysis indicated that 6 factors were extracted from anthropometric measurements through analysis and those factors comprise 73.807% of total variance. 3 clusters were categorized using 6 factor scores by cluster analysis. Type 1 was taller than other types, had average size in circumference, width and thickness and was bending somatotype. Type 2 exhibits a large circumference in the upper body and straight somatotype. Type 3 was characterized by short, exhibits a large circumference in waist, abdomen and hip and swayback somatotype.