• Title/Summary/Keyword: design criteria

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Optimization and Evaluation of Flight Control Laws to Satisfy Longitudinal Handling Quality and Stability Margin Requirements (종축 비행성 요구도 및 안정성 여유 만족을 위한 비행제어법칙 최적화 및 평가)

  • Kim, Seong Hyeon;Ko, Deuk Won;Lee, Tae Hyun;Kim, Dong Hwan;Kim, Byoung Soo
    • Journal of Aerospace System Engineering
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    • v.15 no.5
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    • pp.8-15
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    • 2021
  • This paper describes a design method using an optimization technique to satisfy the longitudinal handling quality of high maneuverable jet aircraft. The dynamic inversion technique was applied to the target aircraft, and the control gain optimization satisfied the longitudinal short-period handling quality, however, the stability margin was not considered. If the stability margin is not satisfied, it is necessary to directly readjust the gains through trial and error methods for improvement. To improve this, an additional compensator and an optimization constraint were added to the control gain optimization procedure. In addition, the degree of handling quality satisfaction with the optimization result was reevaluated, and additional control evaluation criteria for the convergence of the time response and the steady state error that the flight performance requirement set as the optimization constraint cannot be reflected, and the results are described.

A Study on the Type of Reading Aloud Performance for Children (어린이를 위한 낭독공연의 유형 연구)

  • Oh, Pan-Jin
    • (The) Research of the performance art and culture
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    • no.37
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    • pp.223-247
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    • 2018
  • A reading aloud performance is an activity in which the actors convey the meaning of the play to the audience through reading the play without memorizing the play. Although this term has been used for a long time, it can be said in the early 2000s that Korea began to pay attention to reading aloud performance in the cultural world. As the theater education is strengthened in the 2015 revision curriculum, interest in this "reading aloud performance" is also growing. In this article, we analyzed the reading aloud performance of the 8th contemporary Japanese drama '2018' in order to utilize the reading aloud performance in the educational field and to utilize it in the lecture of the children education. There are two types of rehearsals for the actors on stage: 'Reading by watching drama', 'Playing by memorizing drama', and 'Mixing two types'. In the end, the key is that there is no set rule for the type of reading aloud performance. It's not trouble to see or not to see the play. It is not necessary to have a stereotype that you should do a proper reading aloud performance in consideration of your situation, but that you should do this. If children understand the concept of read aloud performance in a flexible way, the educational effect will be greater. Based on this analysis, we suggested 'not sticking to the form of reading aloud performance' and 'choosing various types of reading aloud performance' as a criterion for applying to the education field for children. In addition, the sub-criteria required for selecting 'various types of lecture performances' include' selecting a specific scene in the content of the play ',' considering the level or situation of the student ',' not hesitating to make a new type of lecture performance '. I hope that this article will be a stepping stone to revitalize the discussion in the educational world where discussion on the performance of reading aloud is requested, and to solve the problem of lack of educational design due to lack of theory.

Structural Integrity Assessment of Helicopter Composite Rotor Blade by Analyzing Bird-strike Resistance (조류충돌 해석을 통한 헬리콥터 복합재 로터 블레이드 구조 건전성 평가)

  • Park, Jehong;Jang, Jun Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.8
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    • pp.8-14
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    • 2019
  • Bird-strike is one of the most important design factors for safety in the aviation industry. Bird-strikes have been the cause of significant damage to aircraft and rotorcraft structures and the loss of life. This study used DYTRAN software to simulate the transient response of an Euler-Lagrangian composite helicopter blade that has been impacted by a bird. The Arbitrary Lagrangian Eulerian (ALE) method and a suitable equation of state were applied to model the bird. ALE was applied to the bird-strike analysis due to the large difference between the properties of the blade and bird. The debris of the bird was assumed to be a fluid and applied as Euler elements after the collision. Through the analysis of bird impacts, the leading-edge of the rotor blade (50.8 mm) was used to identify a positive margin of 1.18 based on the TSAI-FILL criteria. The results are assessed to be sufficiently reliable and may be evaluated to replace tests with various analysis conditions. The structural stability of the rotor blade could be assessed by applying various load conditions and different modeling methods in the future.

A Study on the Multi-dimensional Greening Preferential Factors for Securing Green Spaces in Cities (도시 녹지 공간 확보를 위한 건물의 입체녹화 선호요인에 관한 연구)

  • CHOI, Jae-Hyun;LEE, Myeong-Hun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.6
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    • pp.521-530
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    • 2019
  • With a view to respond to urban climate change issues and improve the urban environment in a qualitative manner, the strategy of multi-dimensional greening of the traditional markets in the City of Seoul to secure the multi-dimensional green spaces can result in a significant effect in terms of landscaping, environment, and spatial aspect. The purpose of this study is to examine the elements of multi-dimensional greening for the multi-dimensional greening of buildings in order to enhance the greening function within urban phenomena and, with this, establish the criteria for success introduction of multi-dimensional greening and its qualitative expansion. For this, a total of 569 consumers of traditional markets have been interviewed, and the data from their questionnaires were analyzed through SPSS and AMOS software. The result of the analysis showed that the elements of the multi-dimensional greening of traditional markets, such as the economical, physical, functional, visual, and facility aspects all affected the consumer expectation in a positive manner. Also, depending on the gender of the customers of traditional markets, the ecological aspect among the elements of multi-dimensional greening had a significant difference. And, by the age, the functional, physical, and visual aspects of the elements of multi-dimensional greening showed a significant different. And, the expectation on the multidimensional greening of traditional markets also showed a statistically significant difference. By the level of education, there were significant differences in terms of the physical and visual aspects of the multi-dimensional greening elements. And, the level of expectation on the multidimensional greening also differed significantly.

The Short Term Effects of an Early Intervention Program for Alcoholism Prevention in Adults: A Pilot Study (성인대상 알코올중독 예방 조기개입의 단기효과: 예비 연구)

  • Kang, Kyong-Hwa
    • The Journal of the Korea Contents Association
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    • v.18 no.11
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    • pp.550-561
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    • 2018
  • The aim of this study was to investigate the short term effects of early intervention on alcohol knowledge, alcohol expectancies, drinking refusal self-efficacy for alcoholism prevention in adults and to examine its applicability in the field. This study was a non-equivalent control group pre-post quasi-experimental design. The participants were currently working, and were 12-25 points on result of the Alcohol Use Disorders Identification Test(AUDIT). The participants were a total of 25 men: 13 in the intervention group and 12 in the control group. The intervention group participated in early intervention program once a week for 4 weeks and the control group received only a booklet of alcohol related information. A chi-square test, t-test, Mann-Whitney U test were analyzed by using IBM SPSS Statistics 20.0. The intervention group had significantly higher the alcohol knowledge(t=1.258, p= .002), the negative alcohol expectancies(t=-1.346, p= .042), and the drinking refusal self-efficacy(t=2.817, p= .010) than the control group. In the future, it is need to apply the criteria of problem drinkers considering cultural characteristics, recruitment of participants, and motivational enhancement intervention using motivational interviewing. Especially, web-based alcohol related information providing program will help raise awareness of problem drinking. Early intervention program needs to be applied in community settings where problem drinkers are easily accessible.

Melatonin for Treatment of Delirium in Hospitalized Patients : Retrospective Trial (입원 환자의 섬망 치료에서 멜라토닌의 효과에 관한 후향적 연구)

  • Yang, Jung Woo;Kim, Jong Woo;Kang, Won Sub;Lee, Sang Min;Kim, Young Jong;Paik, Jong-Woo
    • Korean Journal of Psychosomatic Medicine
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    • v.26 no.2
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    • pp.112-118
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    • 2018
  • Objectives : Delirium is one of the most common mental illnesses that can affect cognitive function. Melatonin has been shown to be effective in the treatment of insomnia, and recent studies have shown a protective effect to prevent delirium. This study was conducted to investigate the efficacy of melatonin in delirium patients. Methods : All patients were referred to psychiatric department for insomnia and symptoms of delirium, and were diagnosed delirium by the DSM-5 diagnostic criteria. We compared base line severity of delirium with K-DRS-R-98-R (Korean version of Delirium Rating Scale revised 98) and after taking 2mg of melatonin, retrospectively. The side effects were also identified by referring to the medical records. Results : A total 21 patients had taken melatonin for insomnia and delirious symptoms. The K-DRS-R-98 scores were decreased from $15.24{\pm}2.64$ before treatment to $6.57{\pm}5.42$ after treatment. And CGI-S scores were also decreased from $4.14{\pm}0.48$ before treatment to $2.81{\pm}0.93$ after treatment (p<0.05). Conclusions : This study illustrates the possibility of melatonin as an effective treatment option for delirious symptoms such as disorientation, motor agitation, lability of affect and hallucinations as well as insomnia, with less concerns of drug side effect. Further study with a larger sample and prospective design will be required to confirm these results.

Research of Usability Test on Disabled Welfare Vehicle for Guardians and Passengers of Disabled People (장애인 보호자 및 탑승자를 대상으로 한 장애인 복지차량 사용성 평가 연구)

  • Rhee, Kun Min;Kim, Dong Ok
    • 재활복지
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    • v.20 no.3
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    • pp.141-161
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    • 2016
  • This research is to anticipate problems of Ray's disabled experiment welfare vehicles for 17 drivers with disability, improving them. In addition it is to provide the criteria for ergonomic design based on perspective of drivers with disability by investigating 18 items of usability test. The results are as follows. First, satisfaction degree of Ray, disabled experiment welfare vehicle, was shown to be 3.88 which is higher than normal vehicles whose degree is 3.20. This showed that the disabled experiment welfare vehicle is the one with much improvement. Second, so as to develop a welfare vehicle it needs to take into account some factors including rear slope, wheelchair locker, seat belt, safety grip, and high roof. Third, in case of rear slope, high roof and width of manual or automatic wheel chairs should be considered and motor-operated device should also be taken into account for safety lockers, which make a wheelchair firmly fixed. Moreover, motor-operated seat and rear slope can be chosen for either of the disabled and the elderly.

Vertical Temperature Difference of Steel Box Girder Bridge Considering Asphalt Thickness of Concrete Deck (콘크리트 바닥판의 아스팔트 두께에 따른 강박스거더교의 상하 온도차)

  • Lee, Seong-Haeng
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.3
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    • pp.602-608
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    • 2019
  • The purpose of this study was to calculate the temperature difference of the sectional elevation according to the asphalt thickness of the steel box girder bridge deck and provide data on the design basis accordingly. Asphalt thicknesses produced four steel box girder model specimens of 0mm, 50mm, 100m and 150mm. In each model, 17 to 23 temperature sensors were attached to upper concrete and steel box girders. Six temperature gauges were selected to compare the temperature difference with Euro codes. The maximum and lowest temperature were calculated at the reference atmospheric temperature of each model, and the temperature difference (slope) was calculated based on this calculation. Four models of temperature difference are presented at each model. The 0mm to 100mm temperature difference models showed a -0.9 to -1.5 degree lower temperature difference compared to the temperature difference of Euro codes at the top of the slab. Overall, the measured temperature difference was found to be between 5.45% and 8.33% compared to the Euro code. The standard error coefficient, which was calculated by multiplying the average temperature with the standard error, was calculated from a range of 2.50 to 2.51 times the average at the top and bottom. It is estimated that the proposed temperature difference model can be used as a basic data when calculating temperature difference criteria for bridges in Korea.

Classification of cold regions and analysis of the freeze-thaw repetition cycle based on heat transfer quantity by freezing test (실내동결시험을 통한 열류량 분석에 따른 동결-융해 조건 분석 및 한랭지역의 분류)

  • An, Jai-Wook;Seo, Jeong-Eun;Jung, Min-Hyung;Seong, Joo-Hyun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.20 no.6
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    • pp.957-972
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    • 2018
  • Tunnels constructed in cold regions can cause serious defects such as cracks and leaks due to external temperature changes in the portals and vents. In order to prevent the freezing damage of the tunnel, appropriate measures should be applied to the section where the freeze damage is concerned. However, the specific criteria and contents for judging whether or not the anti-freeze measures are applied are not presented. In this study, the laboratory freezing tests on the temperature changes of the concrete specimens under freezing conditions were carried out. And the freeze-thaw repetition cycle (F), which can judge the possibility of freezing damage, were presented based on the heat transfer quantity (W) by experimental results of case studies. Also, we propose a classification of cold regions considering the climatic characteristics of Korea for using it to efficient design and maintenance.

A Study on the Adequacy Evaluation of Criteria of Occupant Load Density in School Classrooms (학교 교실의 재실자밀도 기준 적정성 평가에 관한 연구)

  • Seo, Dong-Goo;Hwang, Eun-Kyoung
    • Fire Science and Engineering
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    • v.32 no.6
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    • pp.134-140
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    • 2018
  • This study examined the adequacy of a school classroom's occupant load density standard to cope with the issues associated with the decreasing number of students and regional variations. Therefore, this study analyzed the occupant load density standards of kindergarten, elementary school, middle school, high school, and universities using the data open to the public by the Ministry of Education. The results revealed a high variance in the occupant load density according to the school type. The median values were 1.49, 3.45, 2.64, 2.45, and $3.41m^2/person$ for kindergarten, elementary school, middle school, high school, and universities, respectively. Although the occupant load density was higher than the current standard ($1.9m^2/person$), except for kindergarten, the present standard did not need to be improved immediately, considering the purpose of calculating the maximum occupancy. On the other hand, if improvements are made in line with other enhancements of a national education policy, it will be possible to mitigate the measure to $2.5m^2/person$ based on the survey results.