• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.18 no.2
• /
• pp.54-59
• /
• 2010

The flight deck crew must manage complexity during daily flight operations. The Airline may obtain data regarding threats and errors through LOSA(Line Operations Safety Audits) on normal flights as predictive safety tool in Safety Management System of the Airline to actively improve the systems such as SOP(Standard Operation Procedure), training, evaluation and the TEM(Threat and Error Management) for the flight deck crew. The flight deck crew make errors when they fail managing threats. The crew mismanage around ten percent of threats and commit errors. The major mismanaged threats are aircraft malfunction, ATC(Air Traffic Communication), and wether threats. The effective countermeasures of TEM for manageing threats are leadership, workload management, monitor & cross check, Vigilance, communication environment and cooperation of the crew. It is important that organizations must monitor for the hazards of threats and improve system for the safer TEM environments.

• Journal of Korean Ophthalmic Optics Society
• /
• v.8 no.2
• /
• pp.57-63
• /
• 2003

To investigate the RMS SD(Root Mean Square Spot Diameter) in a back focal plane as the front surface power, the center thickness, and the refraction index vary, we use programs which are Cove V and LOSA 2.0, and consider a spectacle lens with back vertex power of -4.00D and diameter of 70 mm. We also consider the front surface power varied from 0.00 to 10.00D, the center thickness varied from 1.1 to 2.0 mm, and the indices which are $n_d$ = 1.498, 1.523, 1.586, and 1.660, respectively. As the front surface power increases the RMS SD in the back focal plane increase rapidly. When the refraction index increases, the RMS SD in the back focal plane decrease and the variation of RMS SD in the back focal plane decreases as the front surface power increases. When the center thickness of spectacle lens increases, the RMS SD in the back focal plane is constant and the edge thickness of that increases. We know from these results that the image in the back focal plane of a spherical spectacle lens improves as the front surface power increases and the refraction index decreases.

• Nuclear Engineering and Technology
• /
• v.54 no.10
• /
• pp.3824-3832
• /
• 2022

Prompt capture gammas are an important part of the fission reactor gamma field. Because some of the structural materials after neutron capture can emit photons with high energies forming the dominant component of the gamma spectrum in the high energy region, the following study of the high energy capture gamma was carried out. High energy gamma radiation may play a major role in areas of the radiation sciences as reactor dosimetry. The HPGe measurements and calculations of the high-energy aluminum capture gamma were performed at two moderator levels in the VR-1 pool-type reactor. The result comparison for nominal levels was within two sigma uncertainties for the major 7.724 MeV peak. A larger discrepancy of 60% was found for the 7.693 MeV peak. The spectra were also measured using a stilbene detector, and a good agreement between HPGe and stilbene was observed. This confirms the validity of stilbene measurements of gamma flux. Additionally, agreement of the wide peak measurement in 7-9.2 MeV by stilbene detector shows the possibility of using the organic scintillators as an independent power monitor. This fact is valid in these reactor types because power is proportional to the thermal neutron flux, which is also proportional to the production of capture gammas forming the wide peak.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.29 no.2
• /
• pp.36-46
• /
• 2021

The purpose of this study is to ensure safety by proactively identifying hazards that could be derived from changes in mission form and environment as the advanced aircraft such as F-35A stealth fighter, KC-330 Multi-role transport and tanker, RQ-4B high altitude unmanned reconnaissance aircraft, etc are introduced that the Republic of Korea Air Force(ROKAF) has never been operated so far. To this end, the safety management methods based on proactive and predictive approaches used in advanced countries(US Air Force, UK Royal Air Force, Royal Australian Air Force) operating aircraft types same or similar things being newly powered by the ROKAF were reviewed. In addition, the direction for improvement of the safety management methods operating in the ROKAF and the measures necessary for establishment of the new safety management techniques to be applied were suggested.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.9
• /
• pp.4719-4724
• /
• 2012

This study aimed to analyse the participation of women of reproductive age in a cancer screening program, and survey reasons for non-screening in a region from Mexico with high cervical cancer mortality. A total of 281 obstetric patients from a previous HPV study in a social security hospital during 2008-2009 were included. Reasons for not participating in the screening were directly asked. HPV positive patients were invited to participate in an informative workshop, and they filled in a knowledge questionnaire. The women ranged in age from 14-47 years; 123 (43.8%) had never participated in screening, of which 97 (78.9%) had their first sexual intercourse 2 to 10 years ago, resulting in 25% HPV positive. Screening history was strongly associated with 2 or more gestations (OR=10.07, p=0.00) and older age (OR=6.69 p=0.00). When 197 women were contacted and interviewed, reasons referred for non-screening were ignorance, lack of interest or time, recent sexual onset, shame and fear. More than 50% of the workshop participants showed knowledge of HPV, while 38.9% and 25% knew about Pap smear and cervical cancer. A high percentage of women of reproductive age have never had a Pap smear. Promoting the screening program in medical facilities seems to be important in this population. New approaches to inform vulnerable individuals on the benefits of screening need to be implemented, especially for young women.

• Korean Journal of Environment and Ecology
• /
• v.10 no.2
• /
• pp.211-239
• /
• 1997

The flora of Oesorak in the Soraksan National Park including Chombongsan(Mountain) and Kwanmobong(Peak) were surveyed from February to August, 1996. These areas have very rich and diverse flora;620 taxa with 89 families, 321 genera, 526 species, 2 subspecies, 89 varieties and 3 forms in the Oesorak, 404 taxa with 251 genera, 350 species, 1 subspecies, 51 varieties and 2 forms in the Chombongsan(Mountain), 286 taxa with 206 genera, 233 species, 1 subspecies, 50 varieties and 2 forms in Kwanmobong(peak). The Oesorak had very distinct floristic characteristics such as the wild habitats of Asarum maculatum(Aristolochiaceae) and Ilex macropoda(Aquifoliaceae). In the phyorgeographical point of view, the six species such as Sapium japonicum (Euphorbiaceae), Euphorbia joldini(Euphorbiaceae), Ilex macropoda (Aquifoliaceae), Styrax japonica (Styracaceae), Carex sideros ticta (Cyperaceae) and Asarum maculatum (Aristolochiaceae) were naturalized into this region, while the 17 taxa such as Abies neprolepis(Pinaceae), Pinus pumila(Pinaceae), Thuja koraiensis(Cupressaceae), Allium senescens(Liliaceae), Lilium distichum(Liliaceae), Saxifraga punctata(Saxfragaceae), Rosa marretii(Rosaceae), Bupleurum euphorbioides(Umbelliferae), Androsace cortusaefolia (Primulaceae), Peducularis mandshurica(Scrophulariaceae) and Leontopodium coreanum (Compositae) were distrivuted to this region. The colonizing weedy species such as Ixris repens (Compositae) were distributed to this region. The colonizing weedy species losa(Labiatae) and Rosa rugosa(Rosaceae) were naturalized into ca. 900m at sea level mainly due to the sand soil from the seashore. Mountain roadbed is susceptible than other areas to the slippery road problems, due largely to snow and rain, particularly during winter. Sand soils from seashore are utilized to minimize this slip in traffic operation.