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        검색결과 130

        41.
        2018.09 구독 인증기관 무료, 개인회원 유료
        본 연구는 소방무인기 운용지침(안)을 제안하고자 비행환경 계측과 영상분석을 실시하였다. 데이터 수집을 위 해 계측용 소방무인기를 이용한 재난 및 사고현장의 고도별 온도, 고도별 풍속 측정 및 데이터 분석을 통한 비행영향 요소, 비행임무조건, 비행한계 등을 도출하였다. 특히 무인항공기의 운용에 있어 장애요인을 분석하고 실질적인 운용 계획을 수립하고자 산악실험, 해안실험, 고도별 가시도 실험 등 다양한 실험을 실시하였으며, 사고현장 비행계획을 위한 재난 현장 비행사례 영상을 분석하였다.
        4,000원
        42.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        가루깍지벌레(Pseudococcus comstocki)는 전 세계적으로 배를 포함한 과수와 작물에 피해를 주는 해충으로 성페로몬을 이용하여 가루깍지 벌레를 방제하기 위하여 가루깍지벌레 수컷의 온도별 발육과 교미비행 및 비행에 미치는 영향을 조사하여 방제에 적용하고자 본 연구를 수행하였다. 가루깍지벌레의 온도별 발육기간은 15℃에서 알이 산란 및 부화되지 않았고, 25℃까지 발육기간이 짧아지다가 30℃에서 다시 늘어났다. 산란수는 25℃에서 평균 482개로 나타났으며, 성비는 15℃, 20℃, 25℃에서 50%에 육박하였지만 30℃에서 수컷의 성비가 37%였다. 비행패턴은 오전에 비행이 많았고 그 중에서도 해가 뜨고 난 직후 2시간 이내에 가장 많았다. 광주기가 달라지더라도 해가 뜨고 난 후 4시간 사이에 비행하 는 개체가 많았다. 암조건만에서 암수를 사육하는 경우에도 비행이 일어났다. 상승 바람의 풍속에 따른 가루깍지벌레 수컷의 비행을 조사한 결과, 0.5 m거리 일 경우 1.5 mph 이상에서는 비행을 하지 못하였다. 배원에서 수컷의 비행은 2 m 이상에서는 채집되는 개체가 거의 없었고 1.5 m에서 가장 많은 수가 포획되어 트랩을 설치하는 높이로 가장 적합하다고 판단된다. 수컷 방사지점과 트랩 사이의 비행가능 거리를 보면, 0.5 m, 1 m, 5 m까지는 트랩에 잡히는 수가 많았고 10 m, 15 m, 20 m에서 적었다. 다만, 50 m까지도 채집되는 것으로 보아 성페로몬 트랩을 이용하여 50 m 이상 떨어져 있는 수컷도 유인할 수 있을 것으로 사료된다.
        4,200원
        43.
        2018.04 구독 인증기관·개인회원 무료
        Purpose:Conventional pre-saturation pulse for suppressing venous signals cannot be applied to time-of-flight magnetic resonance angiography(TOF-MRA) at 7 Tesla MRI due to specific absorption rate(SAR) limitation. The SAR could be attenuated with using low saturation flip angle, but a few repetitions are needed to reach signals below the steady-state signal of the brain tissues. The purpose of this study was to suppress venous system with clinically acceptable acquisition time by using 90 degree flip angle. Methods:The standard slab-selective radio-frequency and gradient waveform were modified to new-shaped models by minimum-time variable-rate selective excitation(Min-VERSE) algorithm. Excitation slice profile was measured and evaluated by a phantom scan. In volunteer measurement, the vessel-tissue contrast ratio of the sinuses(VTCR_S) and middle cerebral artery(VTCR_MCA) were assessed in correlation to surrounding tissue and compared to the values measured by the conventional TOF(cTOF) pulse sequence. Results:The experimentally-measured profiles showed that there was good agreement between conventional and modified pulse. The total scan time was 5 min 55 sec(Min-VERSE 90 FA, TR 28 ms) and 8 min 50 sec(90 FA, TR 42 ms). The quantitative results of ROI analysis were nearly similar, except the venous signal and VTCR_S at Min-VERSE 90 FA. Conclusions:We have presented that the use of Min-VERSE with high flip angle was useful. The total acquisition time was faster about 3 minutes and the signal analysis was hardly different to the values acquired by the values of 90 FA at cTOF. Since 7T MRI has been suitable for ultra-high resolution imaging, our protocol would be used by default for diagnosing various intracranial vascular pathologies.
        44.
        2017.11 구독 인증기관·개인회원 무료
        본 연구에서는 piperazine 기반 상용화 된 NE70 분리막 표면 성분인 아마이드기가, 산 가수분해 이후 생성된다고 알려져 있는 카르복실과 아민기에 대한 분석을 하고자 한다. 실험 방법으로 15 w/v% 황산 수용액 조건에서 7일간 노출 전/후의 NE70 분리막을 ToF-SIMS 기기를 이용하여 카르복실산과 아민기를 포함하는, Molecular weight이 120 미만인 이차이온들을 비교하였다. 또한, 상대적으로 내산성이 있는 m-phenylene diamine 기반 상용화 된 NE90 분리막을 15 w/v% 황산 수용액 조건에서 63일간 노출 전/후 샘플을 비교군으로 두어 NE70 분리막에서 발생 되는 peak intensity 차이는 산 가수분해로 인해 발생한 것임을 추가로 확인 하였다.
        47.
        2017.10 구독 인증기관·개인회원 무료
        Since flight operations are determined by real-time weather conditions, the importance of weather information utilization in the airline industry is absolutely critical. Especially, abnormal flight operations due to the weather phenomenon is directly linked to a loss of airline, and also causes a deterioration in the quality of customer service. Therefore, this study analyzes occurrence conditions and correlates abnormal flight operations by the meteorological phenomenon at 4 major airports in Korea. Based on these results, it is aimed to provide a basis for stable flight operation to make the best decisions.
        48.
        2017.10 구독 인증기관·개인회원 무료
        The symptoms of pine wilt disease caused by the pine wood nematode (PWN, Bursaphelenchus xylophilus), whichis recognized as a major forest pest. The PWN is transmitted by Monochamus saltuarius adults to healthy Korean whitepine (Pinus koraiensis). Because flight capacity of vector insects is important to protect pine forests, we tested flightdistance of M. saltuarius adults using flight mills in relation to biological characters (sex, age, and body weight). In addition,flight distance of M. saltuarius adults was compared between mated and unmated beetles to test effect of sexually matureon flight capacity. Although unmated adult beetles were more rapidly die compared with mated adults, total cumulatedflight distance during entire lifespan was differed according to whether mating or not, i.e., unmated adult beetles moretraversed than mated adults. Proportion of intermittent flights in mated females was significantly lower than others.
        49.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Safety flight training can be done, through the platform proposed in this paper. This paper designed a flight dynamic model and identified essential functions in order to enable pilots to simulate a training environment similar to the actual. It also design activity diagram, concept as well as class diagram. This paper presents the main features and direction of aircraft to be equipped in the future standard platforms. By design main class of flight dynamic and description. it will help developer to setup the standard platform for aircraft simulation.
        4,000원
        52.
        2016.07 구독 인증기관·개인회원 무료
        Create, develop, maintain and nurturing the passengers-airline relationships is crucial in a very competitive market in Europe. Relationship quality and behavioural intentions to fly again in the same airline carrier and recommend to others are core outcomes which may result from a favourable travel experience over time. However, the complexity and the multidimensional phenomenon lead us to develop a holistic framework, which posits that relationship quality and behavioural intentions do not depend on individual air-flight attributes and other individual demographicpsychological variables but on specific configurations of such attributes and variables. Thus, the framework of this study is investigated using qualitative comparative analysis and a sample of 304 passengers. Accordingly, the property space consists of all combinations of binary states, that is, presence or absence, of the 7 in-flight attributes (air quality, temperature, odour, noise, crew, layout and equipment/amenities), frequency of fly in an airline carrier, the type of airline carrier and demographic-psychological variables (age, gender, mindful) (that is, 212 combinations or configurations). Data from both Portuguese and non-Portuguese passengers, who have air travel experiences through Europe in both low cost carriers and legacy airlines (also called traditional or flag airlines) are used to test the hypotheses. The Lisbon airport agreed in helping to conduct the survey during October 2015. Research Question: Which configurations of in-flight attributes, demographicpsychological variables, frequency of fly in an airline carrier and type of airline carrier lead to relationship quality and behavioural intentions? The findings of the current study highlight the importance of coaligning the multiple attributes of air-flight attributes and other individual demographic-psychological variables, also including the frequency of fly in an airline carrier and type of airline carrier, for increasing relationship quality and behavioural intentions. Here the findings point out that complexity theory and QCA are useful tools for understand that simple antecedent conditions relate to an outcome condition of interest positively, negatively, and not at all, which of these three relationships occur depends on the observed complex antecedent conditions in which the simple antecedent conditions occur. Positive outcome (relationship quality or behavioural intention) is not the mirror opposite of negative outcome. By employing QCA, airline managers in Europe can identify whether and under what circumstances individual attributes and other variables will increase (or decrease) the relationship quality and behavioural intentions. QCA can also help managers uncover alternative ways for combining the attributes in order to induce behavioural intentions. Overall it is possible to see that crew and equipment & amenities, particularly for mindful passengers, emerge in several configurations as essential elements for the four outcomes: satisfaction, trust, affective commitment and behavioural intentions. For passengers not affectively committed to an airline, satisfaction plays an important role in their behavioural intention to fly again in the same airline carrier and recommend it to others. The combination of trust and affective commitment may also generate the intention to fly again in the same airline carrier and recommend it to others, particularly for mindful passengers. The findings contribute to managerial practices by providing new insights for improving the in-flight service provide and process. The findings also contribute to theoretical advancing of how passengers’ in-flight evaluations and their experience with an airline relate to their assessments of relationship quality and behavioural intentions.
        53.
        2015.10 구독 인증기관·개인회원 무료
        To develop an empirical degree-day model for predicting the spring flight period of the bark beetle, Ips subelongatus Motschulsky, based on field observation, field studies were biweekly conducted in three Japanese larch (Larix kaempferi) forests in In-je, Korea from 2013 to 2014. To validate this degree-day model, we compared the model-predicted values with observed emergence data of I. subelongatus in 2015 spring at one of the sites. The flight period of over-wintering generation began on April and ended May, and flight of next generation lasted until October. The lower developmental threshold temperature (LDT) was estimated using spring emergence of I. subelongatus and field temperatures. Then a degree-day model was constructed, based on LDTs estimated from field observations data. The baseline temperature with the highest coefficient of determination was considered the LDT, and this was estimated to be 6.0℃. The explanatory power of the model was 88%. This model accurately predicted the flight of I. subelongatus in 2015 spring, as the estimated median flight dates was 1 days earlier than the corresponding observed flight date. The results of the goodness-of-fit test did not differ between observed and estimated values (ks = 0.21, P = 0.54).
        54.
        2015.06 구독 인증기관·개인회원 무료
        A flight suit worn by fighter pilots in the Korea Air Force is in the form of coveralls and can be donned/doffed with a slide fastener located on the center front of the body. This all-in-one styled garment encompasses the easy movement of an Air Force pilot in the cockpit (Choi, 2012) as well as protects from flames in an emergency. The standard Korean flight suit was designed based on a modulated American flight suit (Jeon, Park, You, & Kim, 2010); however, it is necessary to develop a new Korean flight suit with a Korean pilot-centered design. This study investigates wearing conditions and satisfaction of Korean flight suit wearers and provides basic data for a user-centered Korean flight suit design. Researchers visited two Korea Air Force wings and interviewed the fighter pilots. The results of the interview were derived through a questionnaire. The main topics of the questionnaire were: demographics, actual wearing conditions, size/fit, subjective perceptions of comfort on mobility, satisfaction of appearance, frequency of pocket usage, improvement requirements and fabric satisfaction. A total 439 questionnaires were collected in January 2015 and 428 used for analysis analyzed (except for 11 female responders).The average age of respondents was 29.12±4.67 years old and their mean work experience was 5.96±4.46 years. Over half of those questioned were captains(52.6%).The results of the questionnaires are summarized as follows. First, only 45.8% of respondents filled their chest size; however, most of them completed their height and weight. There were 52.8% who referred to their height (or used eye measurement)when selecting the flight suit size, even though the actual sizing system for Korean flight suits suggests a height and chest size by choice. It is necessary to offer new guidelines in which the wearer could select their size easier. Second, the summer flight suit appearance satisfaction was significantly lower(p<0.01) than winter flight suits and could infer (based on the pre-interview responses) that the air- summer suit vents might be a factor that lowered the appearance satisfaction. Third, the responders felt crotch and shoulder inconvenience during body motions; therefore, it is important to set quantitative standard of ease based upon the extension of skin surface and anthropometric properties of pilots. Forth, questions on suit fabric indicated that they were generally satisfied with protection characteristics such as anti-electrostatic qualities (3.27±0.78, 5-point Likert scale) while comfort characteristics such as thermal insulation, absorbency and elasticity indicated a relatively low satisfaction (2.39±0.794, 2.99±0.87 and 2.65±0.83 respectively, 5-point Likert scale). Therefore, fabric development is also needed to improve user satisfaction. Fifth, survey respondents had a negative opinion on changing flight sites. They preferred improvements in quality or better ease of length and width. Therefore, we have to find a way to improve flight suit function with respect to current designs rather than pursuing a dramatic change of appearance.
        55.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Flight dynamic simulation programs are useful to estimate dynamic performances of an aircraft and to develop flight control laws. Usually, simulation programs were developed by the causal programming method which required a distinct relationship between inputs and outputs. Recently, a new approach, acausal programming, has been developed and applied in many fields to deal with the disadvantages of causal simulation programs. The authors have developed a flight dynamic simulation program by using Modelica which is an acausal programming language. The developed program has been tested by several simulations for attitude and velocity hold control. It has been shown that servo systems for control surfaces can be designed by this program. The level of detail of models can be easily increased by using the library of Modelica. The simulation program can be used to develop unmanned aerial vehicles and rotor crafts.
        4,000원
        56.
        2015.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This work aims at analyzing the comparative feature about female flight attendant uniform designs of Korean and Asian region low cost carriers and providing some basic materials for development of these airline companies. As a research method, examinations were carried out on attendant's uniform both theoretically and empirically. Comparison of uniforms was made among the five Korean carriers and ten typical Asian carriers for empirical research. Results showed the followings. First, all Korean low cost carriers were characterized as formal style except Jin Air. Unlike this, Asian low cost carriers appeared as diverse including formal, semi formal, and casual styles with a uniquely differentiated image. Second, all carriers applied their own symbolic color to their uniform. Third, logo or symbol was adopted as a pattern on scarf in the two Korean companies but it didn't take effect practically. For those Asian carriers, embroidery was used on jacket, jumper and collar. They utilized even a merchandising character to put emphasis on airline image. Fourth, diverse petty items with a decorative effect were used in the case of Korean low cost carriers. In the changing period of uniform, nothing much was changed and remained almost the same as before. Those in the Asian region were characterized with the smallest number of items and the preclusion of decorative add-ons on uniform.
        5,100원
        57.
        2015.04 구독 인증기관·개인회원 무료
        Winter phenology (diapause and activity) of insects is expected to change more greatly compared with those of other seasons, because the temperature in winter increased higher than those in other seasons in the temperate regions. However, studies on changes of insect winter phenology due to climate warming are rare. It is expected that winter flights of flies (Diptera) will increase as climate warms. This study is aimed to predict the increase of fly winter flight according to temperature increase using the relationship between the flight and temperature. The survey on flies and weather (temperature and rainfall) was carried out in the Hongneung arboretum in Seoul. Flies were collected weekly from December 2012 to February 2013 using sweeping and Malaise trap. In the survey, 106 flies belonging to 28 morpho-species and 17 families were collected. Richness and abundance of flies were positively correlated with temperature. The increase of fly winter flight (richness and abundance) was projected according to temperature rise using the regression models for relationships between the fly flights and temperature.
        58.
        2015.04 구독 인증기관·개인회원 무료
        Lymantria dispar (Linne), gypsy moth, is known as euryphagous insect and one of forest pests having wide range of host. Female of European Gypsy Moth (EGM) are flightless whereas those of the Asian Gypsy Moth (AGM) are strong fliers. So, we studied flight ability of female AGM by using flight mill device. The flight measurements of female AGM are recorded for an hour using 1- and 2-day-old mated and unmated individuals. As a results, mated females were observed more active the unmated. But, flight speed of unmated females are faster than mated. Flight frequency wasn't showed any significant difference between mated and unmated females.
        59.
        2015.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims at developing the paraglider with the enhanced function and safety of flight by performing the simulation and test of flight with two slots at each wing tip of canopy. When the distributions of velocity and shear stress at wall around the canopy were compared, the canopy with slots showed the distribution of less velocity and shear stress at wall significantly than the canopy without slots by confirming the safety of the paraglider. Series of simulation were conducted to achieve the optimal shape of slots by applying various sizes and positions of the slots, resulting nine cases with the better outcome on which flight tests were based. The flight test results in this study confirmed that canopy with slots showed the improved flight function by increasing the maximum velocity, decreasing the minimum velocity, delaying the stall timing significantly and consequently improving the safety of the paraglider. Based on the simulation and flight tests, three cases with the best outcome have been selected for merchandising strategies.
        4,000원
        60.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        오늘날 여행객들의 증가와 함께 이동수단인 운송수단 또한 대형화 추세로 변화하고 있으나, 필요악인 사고 역시 이에 비례해 끊임없이 발생하고 있다. 그런데 주목할 점은 사고 발생 시 희생자의 규모 등 사고피해의 정도가 천차만별이라는 것이다. 전문가들에 따르면, 이는 사고 당시 승무원들이 보여주었던 상황대처 능력이나 리더십에 기인한 바 크다고 한다. 즉 비상상황에서 승객의 안전을 도모하고자 하는 승무원의 리더십이 어떻게 발현되느냐에 따라 승객의 안전이나 희생정도가 크게 달라졌다는 것이다. 본 논문은 이 같은 사실에 착안해 여객선·항공기 승무원의 리더십과 승객안전 간의 상관관계를 논의하고자 한다. 특히 유사시 여객선·항공기 승무원의 리더십 형성에 결정적인 영향을 미치는 것으로 알려진 안전교육을 중심으로 이를 논의하고자 한다. 구체적으로, 본 논문은 여객선과 항공기의 사고사례를 비교분석함으로써 승무원의 안전교육과 그로 인한 리더십의 형성이 유사시 승객안전의 확보에 얼마나 중요한지 실증하고자 한다.
        5,400원
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