다양한 출구조건이 적용된 초음속 흡입구 공력불안정성 수치적 연구

홍우람(W. Hong),최요한(Y. Choe),김종암(C. Kim) 한국전산유체공학회 2013 한국전산유체공학회 학술대회논문집 Vol.2013 No.5

The present study numerically investigates the flow instability around supersonic inlet, called inlet buzz. Though the flow conditions change linearly, behavior of inlet buzz alters hysteretically. In order to simulate the inlet buzz hysteretic character, computations are conducted with varying mass flow rate. The mass flow rate condition is controlled by an exit throttling plug which moves back and forth to change an exit area. In this paper, a set of simulations with mass flow rate control are presented. This simulations focus on hysteretic buzz characteristics of supersonic inlet according to mass flow rate and the historic path of the mass flow rate change. Firstly, an inlet buzz case with decreasing mass flow rate is simulated. In this process, the inlet buzz characteristic changes from the first mode of a low frequency regime to the second mode of a high frequency regime. In the next, the effect of the increasing mass flow rate on the inlet buzz is examined. This case shows another kind of the buzz transition that the buzz frequency becomes higher in the third mode. The hysteretic inlet buzz has many similarities to the fundamentals of a pipe-type musical instrument such as self-excited feed-back mechanism and overblowing. Considering the similarities, the hysteretic characteristics of an inlet buzz is discussed in the instrumental acoustic point of view.

청소년 입말에 나타난 비속어ㆍ유행어ㆍ은어 사용 실태

김정선(Kim Jung-sun),이필영(Lee Phil-Yong),김태경(Kim Tae-Kyung),이삼형(Lee Sam-hyung),장경희(Chang Kyung-hee),전은진(Jeon Eun-Jin) 한국언어문학회 2011 한국언어문학 Vol.77 No.-

This study investigated and analyzed the expletives, buzz-words, and teenage slangs in adolescents’ spoken language, providing specific lists and frequencies of expletives, buzz-words, and teenage slangs and their usage patterns according to school level and gender. The results are as follows: Firstly, the adolescents use of expletives was examined. They used adverbs of degree and exclamations with a vulgar feel such as “존나, 씨발, 개-, and 처-” a lot. Most of the virotous expletives had to do with sex, and the frequency of those words increased with school level. The girls were not much different from the boys in the use of sex-related expletives. Secondly, the adolescents also used a lot of adverbs of degree and exclamations such as “완전, 개-, 헐, and 대박” in the domain of buzz-words, and the majority of them came into fashion with the extended usage context of communication language. Of its subcategories, the buzz-words that originated in everyday language recorded the highest frequency, with differences in preferred buzz-words between the girls and boys. Finally, adolescents used teenage slangs related to sex, a peer group, and game in high frequency. They spelled teenage slangs either by picking up initial consonant or employing English alphabets for the sake of secrecy. Differences were found in teenage slangs usage according to school level: while the elementary school students used game teenage slangs a lot, the middle and high schoolers used a great deal of delinquency, sex, and violence teenage slangs. Teenage slangs related to body parts or sex acts were used by boys more than girls. The study collected and analyzed adolescent conversations and offered empirical and concrete data about their language uses, thus making a future contribution to the establishment of language policies and educational plans for adolescents. The follow-up study of the study, which analyzed adolescents’ expletives, buzz-words and teenage slangs from the perspective of content, should approach the topic from the perspective of morphology, syntax, and expression. In addition, it needs to conduct in-depth analysis of the contexts in which expletives, buzz-words, and teenage slangs are used.

다양한 출구조건에서의 초음속 흡입구 공력불안정성 수치연구

홍우람,최요한,김종암 한국항공우주학회 2014 한국항공우주학회 학술발표회 논문집 Vol.2014 No.4

본 논문은 흡입구 버즈라 불리는 초음속 흡입구 공력 불안정 현상에 대해 다루고 있다. 흡입구 버즈의 이력적인 특성을 알아보기 위해, 다양한 유량 조건에서 수치해석이 수행되었다. 먼저, 유량이 줄어드는 경우에 대해 수치해석을 수행하였으며, 다음으로는 흡입구 버즈의 이력적인 특성을 알아보기 위해 유량이 다시 증가하는 경우의 수치해석을 수행하였다. 유량이 증가하는 경우 유량이 감소하였던 경우의 주진동수를 따라 다시 감소하는 것이 아니라 오히려 3차의 모드로 증가한 결과를 볼 수 있었다. 이러한 버즈의 거동은 파이프 타입의 악기와 많은 유사성을 공유하는데, 본 논문에서는 이를 고려하여 음향학적인 관점에서 버즈의 거동을 해석하고 이력적인 특성에 대해 알아보도록 하였다. The present study explores the flow instability around supersonic inlet, called inlet buzz. A set of computations are conducted under varying mass flow rate condition in order to investigate hysteretic character of inlet buzz. An inlet with decreasing mass flow rate is simulated firstly. Secondly, the effect of the increasing mass flow rate on inlet buzz is examined. This case shows another kind of the unreported buzz transition that the buzz frequency becomes higher in the third mode. The newly found hysteretic inlet buzz shares many similarities with the fundamentals of a pipe-type musical instrument. Considering the similarities, the hysteretic characteristics of inlet buzz are explained from the instrumental acoustic point of view.

OTT 시대 한국 TV 드라마의 화제성 영향요인: TV 드라마의 넷플릭스 동시방영 여부를 중심으로

어유선,임성준 (주)에스비에스 2024 미디어경제와 문화 Vol.22 No.2

OTT 등장 후에도 TV 드라마는 OTT의 중요한 콘텐츠이다. OTT 등장 후 많은 시청자가TV 대신 OTT 플랫폼을 TV 드라마 시청 매체로 사용하여 전통적인 흥행지표인 시청률의유용성은 한계를 드러냈다. 이에 본 연구는 OTT 시대 시청자 행동을 잘 반영하는 화제성이 TV 드라마 흥행의 선행지표가 될 수 있다 보고 이에 영향 줄 수 있는 요인을 파악 및실증분석했다. 신호이론과 자원기반이론에 기반해 선행연구 결과, 본 연구는 TV 드라마 화제성에 영향 줄 수 있는 요인을 원작 활용 여부, 넷플릭스 동시방영, 지상파 방송사 편성, 감독, 작가, 주연/조연배우 및 제작사의 역량, 회차 개수, 회당 평균 러닝타임으로 선정하고이들이 화제성에 미치는 영향을 실증분석하였다. 본 연구는 넷플릭스 동시방영이 시작된2017년부터 2022년까지 한국 TV 드라마를 대상으로 삼았다. 실증분석 결과, 넷플릭스 동시방영, 지상파 방송사 편성, 감독, 작가, 주연/조연배우의 역량, 적은 회차 개수, 긴 평균러닝타임이 TV 드라마 화제성에 긍정적 영향을 미친 것으로 나타났다. 본 연구 결과는OTT 시대 TV 드라마 동향과 발전에 도움을 줄 것으로 기대된다. Even after advent of OTT, TV dramas remain important content for OTT. Since advent of OTT, many viewers have been using OTT platforms instead of TV for watching TV dramas, revealing limitations of viewership ratings. This study believed that ‘buzz-worthiness’, which reflects viewer behavior, could be leading indicator of TV dramas‘ success, and empirically analyzed factors that can affect buzz-worthiness. Based on signaling theory and resource-based view, this study suggested that factors that can affect buzz-worthiness including simultaneous broadcast on Netflix, capabilities of director, writer, actors, and production company, number of episodes and average running time, and empirically analyzed impact of these on buzz-worthiness over 530 Korean TV dramas from 2017 to 2022. Results indicated that simultaneous broadcasting on Netflix, programming by terrestrial broadcasters, capabilities of directors, writers, and lead/supporting actors, fewer episodes, and longer average running time had positive effects on buzz-worthiness of TV dramas. Results of this study are expected to suggest trends and development directions for TV dramas in OTT era.

보정한 Bleed 모델을 이용한 초음속 흡입구 버즈 제어

곽인근(E. Kwak),이승수(S. Lee) 한국전산유체공학회 2013 한국전산유체공학회지 Vol.18 No.4

Database of a bleed model has been corrected and numerical simulations have been performed to control buzz using the corrected bleed model. The existing bleed model, which was developed as a part of a boundary condition model for porous bleed walls, underestimates bleed flow rate because flow accelerations near the bleed regions are ignored. Also, it overpredicts the sonic flow coefficient when the bleed plenum pressure ratio is high. To correct these problems, and to enhance the performance of the bleed model, the database has been corrected using CFD simulations to compensate for the flow acceleration near the bleed region. Futhermore, the database of the bleed model is extended with the second order extrapolation. The corrected bleed model is validated with numerical simulations of a shock-boundary layer interaction problem over a solid wall with a bleed region. Using the corrected bleed model, numerical simulations of supersonic inlet buzz are performed to find the deterrent effects of bleed on buzz. The results reveal that bleed is effective to prevent buzz and to enhance the inlet performance.

CONSUMER CURIOSITY, ANTICIPATION, AND CLICK-THROUGH: NEURAL SIGNATURES OF DIGITAL BUZZ

Jing Zhang,Jin Ho Yun,Eun-Ju Lee 글로벌지식마케팅경영학회 2018 Global Marketing Conference Vol.2018 No.07

Digital and social media has become an indispensable channel of promotion and marketing to the enterprises. For example, compared to other means of promotional channels, such as television advertising, newspapers, social network services (SNS) are more competitive, more convenient, and lower-cost. Because individuals compose or share those posts anytime, anywhere, information spreads fast and wide on social media. SNS posts can affect people's perception, thus affecting their purchase intention and behavior. A large number of researchers investigated academic issues involved SNS, such as the influence of eWOM in social media on consumers' purchase intentions (Erkan & Evans, 2016). According to Lin and Lu’s research (2011), which suggests that gender difference also exists in social media. In addition, a study identified attributes of social media messaging activities and examined the relationships among those perceived activities, value equity, relationship equity, brand equity, customer equity, and purchase intention through a structural equation model (Kim & Ko, 2012). In this study, we focus on the motivational antecedents of digital buzz on digital and social media. Among many performance metrics of digital marketing, the most important one that really matters to advertisers is click-through. Click-through is believed to reflect viewers’ interest in the product contents that are being shown on screen, and based on that assumption, it opens a new navigation tab, such as the advertiser’s web site that can provide information about products and services of an advertising company. However, there is a caveat here. Since advertisements in digital and social media are often placed on top of the contents that the viewers have already been reading, viewers can accidentally click on the internet advertisements in which they have no interests. Viewers are only annoyed by intrusive re-routing during their digital activities. Hence, it is important that the digital media marketer to be able to distinguish between the click-throughs, knowing the difference between the clicks that are genuinely reflective of a viewer’s interest, or the rest of clicks that are not. For this purpose, we propose consumer curiosity and anticipation as drivers of click-through that are meaningful to digital markers. Consumer curiosity is an important variable that results in click-through behavior, digital propagation or buzz, and further stimulates consumers' consumption activities. In recent years, there are many studies to verify this theory. Online atmospherics have an impact on customer emotions, and perceptual curiosity has a moderating effect existed in the two variables (Koo & Ju, 2010). However, the research about curiosity’s mediation effect on purchase intention aroused by SNS contents is still limited. In addition, the neural research in this field is still limited. The research seeks to understand how the SNS contents affect customer’s curiosity toward the product which the content mentioned. Furthermore, to find the relationship between curiosity and the purchase intention by using neuromarketing methodology. Our goal is to discover the neural signatures of consumers’ motivational state that leads to click-through, exploration of contents, and finally digital buzz behavior. EEG and fMRI are commonly research approaches used in the neuroscience field. EEG detect electric activities in the brain waves and fMRI measures hemodynamic events to discover individuals’ cognitive and motivational states. After content-analyzing top 10 most shared posts in the fashion brands Facebook official account which included luxury brands such as GUCCI, Luis Vuitton, and Herm?s), we extract the attractive posts’ content attributes to be the level of accuracy, graphic quality, and information value. Then, we create two different simulations of social media activities that instigates viewer curiosity at differing levels. By designing an online experiment that examines how different arrays of information can create different levels viewer curiosity in user posts, and by measuring viewers’ intention to propagate the posts, we are able to discover neural signatures of digital buzz. Potential implications to digital marketing of this research in establishing meaningful performance metrics for digital marketing are discussed.

축대칭 초음속 흡입구의 아임계 불안정성 연구

신필권(Phil-Kwon Shin),박종호(Jong-Ho Park) 한국항공우주학회 2004 韓國航空宇宙學會誌 Vol.32 No.8

??초음속 흡입구 buzz는 입구에서의 충격파 패턴의 진동과 내부압력요동을 동반하는 불안정한 아임계 직동으로 정의할 수 있다. 이러한 유동섭동은 연소실 실화나 엔진의 구조적 손상을 일으킬 수 있다. 축대칭, 외부 압축형 흡입구에서 초음속 흡입구의 buzz현상을 조사하기위한 실험적 연구가 수행되었다. 자유류 마하수 2.0에서 카울 입구 직경이 30㎜ 인 흡입구 모델이 시험되었다. 아임계 불안정성은 압력섭동의 주파수 및 입구에서의 충격 파 구조 분석을 통해 조사되었다. 실험결과 전압력 회복비는 0.42에서 0.78까지, 포획 면적비는 0.34에서 0.98까지 변화했다. 아임계 유동의 주파수는 포획 면적비 감소에 따라 증가했으며 주파수는 범위는 224~240㎐ 였다. Supersonic inlet buzz can be defined as unstable subcritical operation associated with fluctuating internal pressures and a shock pattern oscillating about the inlet entrance. The flow pulsations could result in flameout in the combustor or even structural damage to the engine. An experimental study was conducted to investigate the phenomenon of supersonic inlet buzz on axisymmetric, external-compression inlet. An inlet model with a cowl lip diameter of 30㎜ was tested at a free stream Mach number of 2.0. Subcritical instability was investigated by considering the frequency of pressure pulsation and shock wave structure at the inlet entrance. The results obtained show that total pressure recovery ratios were varied from 0.42 to 0.78, and capture area ratio from 0.34 to 0.98. The frequency of the subcritical flow increased with decrease in capture area ratios. Frequency was measured at 224 ~ 240㎐.

카울 위치변화에 의한 초음속 공기흡입구의 버즈억제

신필권(Phil-Kwon Shin),박종호(Jong-Ho Park),이용범(Yong-Bum Lee) 한국항공우주학회 2005 韓國航空宇宙學會誌 Vol.33 No.3

축대칭 외부압축식 초음속 흡입구의 버즈 억제방법을 조사하기위해 마하 2.0 유동에서 실험적 연구를 수행하였다. 흡입구 모델은 고정형이고 내부 수축부는 없으며, 형상변화는 엔진덮개의 교체에 의해 이루어진다. 실험결과 버즈의 원인은 충격파 교차점에서 발생하는 와류면을 경계로 형성되는 불연속 유동장과 관련이 있는 것으로 나타났다. 외부압축식 흡입구에서는 경사충격파를 카울 앞이나 뒤에 위치하게 함으로써 buzz를 억제할 수 있다. An experimental study was conducted at a Mach number of 2.0 to investigate the buzz suppression method on an axisymmetric, external compression supersonic inlet. The inlet model has a fixed geometry with no internal contraction. The inlet configuration was altered by changing the cowling. Results show that source of buzz has been related to the existence in the flow field of velocity discontinuity across a vortex sheet which originates from a shock intersection point. With external compression inlet, buzz can be suppressed by positioning the oblique shock slightly inside or outside of the cowl.

인터넷전문은행의 가입 영향 요인에 관한 연구 : 케이뱅크은행 사례를 중심으로

옥성환,황경태 한국정보기술응용학회 2020 Journal of information technology applications & m Vol.27 No.6

This research analyzes the factors that affect the consumers’ participation of the internet-only banks, and suggests effective financial sales strategies and methods to attract more users. Through prior research review and interviews with experts, the factors affecting the consumers to sign up for the internet banks are identified. The actual user data from the internet banks are used for the analysis, providing more systematic and credible results. The research shows that social media buzz positively affects the user growth, proving Granger Causality relation of increasing social media buzz on K Bank increases K Bank users. The research also shows that marketing activities noticeably impacts K Bank’s positive user growth. On the other hand, the event of Kakao Bank’s grand opening shows negative effect. The results from the research validates the need for periodical monitoring process of social media buzz. Moreover, the research proves that the integrated analysis of social media buzz and marketing effect is also essential.

보정한 Bleed 모델을 이용한 초음속 흡입구 버즈 제어

곽인근(E. Kwak),이승수(S. Lee) 한국전산유체공학회 2013 한국전산유체공학회지 Vol.18 No.4

Database of a bleed model has been corrected and numerical simulations have been performed to control buzz using the corrected bleed model. The existing bleed model, which was developed as a part of a boundary condition model for porous bleed walls, underestimates bleed flow rate because flow accelerations near the bleed regions are ignored. Also, it overpredicts the sonic flow coefficient when the bleed plenum pressure ratio is high. To correct these problems, and to enhance the performance of the bleed model, the database has been corrected using CFD simulations to compensate for the flow acceleration near the bleed region. Futhermore, the database of the bleed model is extended with the second order extrapolation. The corrected bleed model is validated with numerical simulations of a shock-boundary layer interaction problem over a solid wall with a bleed region. Using the corrected bleed model, numerical simulations of supersonic inlet buzz are performed to find the deterrent effects of bleed on buzz. The results reveal that bleed is effective to prevent buzz and to enhance the inlet performance.