• Title/Summary/Keyword: impulsive

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The Effect of Surface Tension on the Transient Free-Surface Flow near the Intersection Point (교차점 부근의 과도자유표면유동에 미치는 표면장력의 영향)

  • Lee, G.J.;Rhee, K.P.
    • Journal of the Society of Naval Architects of Korea
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    • v.28 no.2
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    • pp.104-117
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    • 1991
  • When a body starts to move, the flow near the intersection point between a body and a free surface changes violently and rapidly in a very short initial time interval. This flow phenomena must be investigated whenever one treats the interaction between a body and a fluid, such as the motion of a floating body, sloshing in a tank, wave maker problem, entry of a body into a fluid etc.. Until Roberts(1987), it was widely accepted that a singularity exists at the intersection point. However, he showed that the singularity does not exist if a body moves non-impulsively. In this paper, an analytical solution cosistent for the case of impulsive motion of a body is obtained by including the effect of surface tension. From the characteristics of the newly obtained solution, a critical value associated with an oscillating phenomenon is found, and further more, it is shown that the oscillating phenomenon does not appear in the region where the distance form the intersection point is less than this critical value.

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Experimental Study on Irregular Wave Forces Acting on a Marker Rock Installed on a Submerged Breakwater (수중방파제 천단상의 표식암에 작용하는 불규칙파의 파력특성에 관한 실험적 연구)

  • Hur, Dong Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.4B
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    • pp.413-420
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    • 2006
  • The construction of a submerged breakwater has become increasing due to their multiple effects on the coastal zone. Recently, marker rocks have been installed on the submerged breakwater to indicate its position to the vessels instead of buoy systems, since a buoy is not only improper for the ocean view, but also its mooring system may be damaged by the impulsive wave force caused by wave breaking on the breakwater. The accurate estimation of wave forces on such rocks is deemed necessary for their stability design. In this study, the characteristics of irregular wave forces acting on a marker rock, which was installed on a submerged breakwater, was investigated on the basis of laboratory experiments. It was revealed that the dimensionless highest one-third wave force tends to decrease with increasing the installation distance of a marker rock from the leading crown edge of a submerged breakwater. Also, the drag and inertia coefficients for irregular wave forces, which were obtained using the Morison equation, were investigated in relation to K.C. number.

Measurement of Individuals' Emotional Stress Responses to Construction Noise through Analysis of Human Brain Waves

  • Hwang, Sungjoo;Jebelli, Houtan;Lee, Sungchan;Chung, Sehwan;Lee, SangHyun
    • International conference on construction engineering and project management
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    • 2020.12a
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    • pp.237-242
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    • 2020
  • Construction noise is among the most critical stressors that adversely affect the quality of life of the people residing near construction sites. Many countries strictly regulate construction noise based on sound pressure levels, as well as timeslots and type of construction equipment. However, individuals react differently to noise, and their tolerance to noise levels varies, which should be considered when regulating construction noise. Although studies have attempted to analyze individuals' stress responses to construction noise, the lack of quantitative methods to measure stress has limited our understanding of individuals' stress responses to noise. Therefore, the authors proposed a quantitative stress measurement framework with a wearable electroencephalogram (EEG) sensor to decipher human brain wave patterns caused by diverse construction stressors (e.g., worksite hazards). This present study extends this framework to investigate the feasibility of using the wearable EEG sensor to measure individuals' emotional stress responses to construction noise in a laboratory setting. EEG data were collected from three subjects exposed to different construction noises (e.g., tonal vs. impulsive noises, different sound pressure levels) recorded at real construction sites. Simultaneously, the subjects' perceived stress levels against these noises were measured. The results indicate that the wearable EEG sensor can help understand diverse individuals' stress responses to nearby construction noises. This research provides a more quantitative means for measuring the impact of the noise generated at a construction site on neighboring communities, which can help frame more reasonable construction noise regulations that consider various types of residents in urban areas.

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Key technologies research on the response of a double-story isolated structure subjected to long-period earthquake motion

  • Liang Gao;Dewen Liu;Yuan Zhang;Yanping Zheng;Jingran Xu;Zhiang Li;Min Lei
    • Earthquakes and Structures
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    • v.26 no.1
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    • pp.17-30
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    • 2024
  • Earthquakes can lead to substantial damage to buildings, with long-period ground motion being particularly destructive. The design of high-performance building structures has become a prominent focus of research. The double-story isolated structure is a novel type of isolated structure developed from base isolated structure. To delve deeper into the building performance of double-story isolated structures, the double-story isolated structure was constructed with the upper isolated layer located in different layers, alongside a base isolated structure for comparative analysis. Nonlinear elastoplastic analyses were conducted on these structures using different ground motion inputs, including ordinary ground motion, near-field impulsive ground motion, and far-field harmonic ground motion. The results demonstrate that the double-story isolated structure can extend the structural period further than the base isolated structure under three types of ground motions. The double-story isolated structure exhibits lower base shear, inter-story displacement, base isolated layer displacement, story shear, and maximum acceleration of the top layer, compared to the base isolated structure. In addition, the double-story isolated structure generates fewer plastic hinges in the frame, causes less damage to the core tube, and experiences smaller overturning moments, demonstrating excellent resistance to overturning and a shock-absorbing effect. As the upper isolated layer is positioned higher, the compressive stress on the isolated bearings of the upper isolated layer in the double-story isolated structure gradually decreases. Moreover, the compressive stress on the isolated bearings of the base isolated layer is lower compared to that of the base isolated structure. However, the shock-absorbing capacity of the double-story isolated structure is significantly increased when the upper isolated layer is located in the middle and lower section. Notably, in regions exposed to long-period ground motion, a double-story isolated structure can experience greater seismic response and reduced shock-absorbing capacity, which may be detrimental to the structure.

Range Estimating Performance Evaluation of the Underwater Broadband Source by Array Invariant (Array Invariant를 이용한 수중 광대역 음원의 거리 추정성능 분석)

  • Kim Se-Young;Chun Seung-Yong;Kim Boo-Il;Kim Ki-Man
    • The Journal of the Acoustical Society of Korea
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    • v.25 no.6
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    • pp.305-311
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    • 2006
  • In this paper the performance of a array invariant method is evaluated for source-range estimation in horizontally stratified shallow water ocean waveguide. The method has advantage of little computationally effort over existing source-localization methods. such as matched field processing or the waveguide invariant and array gain is fully exploited. And. no knowledge of the environment is required except that the received field should not be dominated by purely interference This simple and instantaneous method is applied to simulated acoustic propagation filed for testing range estimation performance. The result of range estimation according to the SNR for the underwater impulsive source with broadband spectrum is demonstrated. The spatial smoothing method is applied to suppress the effect of mutipath propagation by high frequency signal. The result of performance test for range estimation shows that the error rate is within 20% at the SNR above 10dB.

A Study on Product Attitude, Satisfaction, and Repurchase Intention toward Celebrity Goods by Type of Consumption Value

  • Mi-Jung Bok
    • Journal of the Korea Society of Computer and Information
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    • v.29 no.9
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    • pp.237-244
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    • 2024
  • This study attempted to categorize the consumption value of 310 ordinary people with experience purchasing celebrity goods and then analyze product attitude, satisfaction, and repurchase intention toward celebrity goods by type. The data were analyzed with PASW 18.0 program. The results of the study were as follows: First, the consumption value types are 'consumption value indifferent type(11.3%)', 'impulsive consumption value seeking type(25.2%)', 'consumption value sensitive type(20.3%)', and 'self-satisfaction seeking type(43.2%)' were categorized into four groups. Second, the analysis of the socioeconomic characteristics by consumption value type and differences in celebrity goods purchasing behavior revealed significant differences only in the average annual purchase frequency and the average cost per purchase. Third, the analysis of consumers' product attitudes, satisfaction, and repurchase intentions toward celebrity goods by consumption value type showed that the consumption value sensitive type highest in all three areas, while the consumption value indifference type the lowest. In the future, there will be a need to analyze the characteristics and desires of consumers who are likely to repurchase celebrity goods.

The reserch of Kim hong-kyung's view of extra meridians -With the connection yin yang wei qiao mai With four trigram constitution theory- (김홍경의 기경팔맥관(奇經八脈觀)에 관한 연구(硏究) - 음양유교맥(陰陽維蹻脈)과 사상체질(四象體質)의 상관성을 중심으로 -)

  • Jung, Hae-Myeong;Yun, Chang-Yeol
    • Journal of Haehwa Medicine
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    • v.22 no.2
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    • pp.13-21
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    • 2014
  • Subject : Kim hong-kyung(金洪卿)'s view of eight extra meridians Object : Kim hong-kyung has not only deeply studied Saam acupuncture but also the function and characteristics of extra meridian at the same time. Especially, he has tried the study to connect yin yang wei qiao mai(陰陽維蹻脈) with Lee je-ma(李濟馬)'s four trigram constitution theory, therefore the author felt the need to make public the theory and started reserch on the theory. Method : I researched the physiological properties of extra meridians through the past eastern medical literature, I reported on the types of people to show well the properties of extra meridians gathering Kum-oh's verbal explanation when I had classes from him. Result : Kum-oh Kim hong-kyung defined meridians as passways of consciousness and feeling, he interpreted 12 meridians and extra meridians with the view of mind, which has very important meanings in the history of acupuncture in the point of first trial to interpret meridians from this view. He explained Ren mai(任脈) and Du mai(督脈) are meridians which show clearly properties of yin-yang to appear trusts of affirmation and distrusts of denial in the mind, as Ren(任) means entrusting and Du(督) means supervising in English. He explained Chong mai(衝脈) is the meridian representing impulsive man that has a meaning of impulse as being suggested the name of Chong mai, because Chong mai is borrowed from Foot shao yin kidney meridian(足少陰腎經). Dai mai(帶脈) is the meridian representing the characteristics of woman that has a meaning of binding as being suggested from the name of Dai mai which acts when people have something on their flank or they are pregnant, because Dai mai borrowed from Foot shao yang gall bladder meridian. He thought that four trigram divided from yin and yang is innate trigram, so Yang wei mai(陽維脈), Yin wei mai(陰維脈), Yang qiao mai(陽蹻脈), Yin qiao mai(陰蹻脈) among extra meridians have connections with Tai-yang ren(太陽人), Tai-yin ren(太陰人), Shao-yin ren(少陰人), Shao-yang ren(少陽人) of Four trigram constitution theory respectively which was created by Lee je-ma. He explained yang means opponents and wei(維) means binding. Yang wei mai is the meridian to be active when opponents bind or intervene in you, also the meridian is well active to the people who easily criticize others who are rude, to the people who well refuse restraints from organization. Because he explained yin means me and wei(維) means binding. Yin wei mai is the meridian to be active when I bind and intervene in opponents. He also state that the meridian is easily active to the people who have a tendency to gather people and make party apparatus by nature. He explained Yang qiao mai is the meridian to be active in the situation that people are waiting for others to bridge gap because yang means opponents and qiao(蹻) which has a meaning of standing on one's tiptoes means bridging gap between people. He also state the meridian is easily active to Shao yin ren who has a tendency to be passive, to easily settle down and not to move by nature. He explained Yin qiao mai is the meridian to be active in the situation that I bridge gap between me and others to make friends, because yin means me and qiao(蹻) which has a meaning of standing on one's tiptoes means bridging gap between me and others. He also state the meridian is easily active to Shao yang ren who is active in every business and who has remarkable ability to make friends. Conclusion : Kim hong-kyung stated the physiological properties of extra meridians as below. Ren mai is the meridian representing positive confidence which is easily active when people have a mind to trust others, Du mai is the meridian representing negative distrust which is easily active when people have doubts. Chong mai is the meridian representing the characteristics of man that has impulsive characteristics. Dai mai is the meridian representing the characteristics of woman to be easily active when she is pregnant. Yang wei mai has close connections with Tai-yang ren who has a tendency to refuse restraints from others and to criticize on opponent's remarks and behaviors that are wrong. Yin wei mai has close connections with Tai-yin ren, as the meridian is active in the situation that people enjoy restraining and intervening in others. Yang qiao mai has close connections with Shao yin ren, as the meridian is active to the people who are negative and passive by nature. Yin qiao mai has close connections with Shao yang yin who has a strong tendency to make friends easily by nature.

Educational Program Development for Improvement of the Quality of Life of Community Residents (지역주민의 생활의 질 향상을 위한 대학의 사회교육 프로그램 개발)

  • Lim, Young-Hee;Wang, Soo-Gyung;Yoon, Eun-Young;Koo, Nan-Sook;Kang, Young-Ja;Park, Sung-Ok;Sohn, Sang-Hee;Cha, Sung-Ran;Lee, Hae-Young;Kim, Yang-Weon;Lee, Eun-Kyung
    • Korean Journal of Human Ecology
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    • v.7 no.1
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    • pp.247-266
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    • 1998
  • The purposes of this study were to investigate problems related to quality of life and to identify residents needs for the university educational program for the community residents. The data were analyzed by using $x^2$-test, F-test and multiple range test. Findings of this study provided some useful implications to develop educational programs for community people. These implications are as follows. In the aspect of home management, the need for education about time management was relatively high and the degree of time conflicts was varied to family size, educational level of house, housewife's employment status and outside work time. In the program area of economic life, education for enhancing ability to cope with unexpected events and impulsive consumption behavior, and education for money management technique and value clarification should be included. There were significant differences in the parents' role difficulties according to mother's age and income. Especially parents' role difficulties were children's social emotional development and educational activity. The major problems in management of clothing and textile products were the change of textile sensation, the poor quality of necessaries, and discoloration. This result suggests that education programs on management of clothing and textiles should be developed. In health and food management it showed that subjects were afraid of cancer, hypertension, cerebral vascular diseases in relation with food habits. Hence program of education for health and good food habits should be developed.

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Improvement of Attention Span and Impulsivity of Children with Attention Deficit Hyperactivity Disorder through Structured Violin Learning (주의력결핍과잉행동장애 아동의 집중력 향상과 충동성 조절을 위한 바이올린 교습 중심의 음악치료 사례 연구)

  • Kang, Hyun Jung
    • Journal of Music and Human Behavior
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    • v.3 no.2
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    • pp.1-14
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    • 2006
  • The purpose of this study is to examine the effect of violin learning as to enhance the attention span and impulsiveness of children with Attention Deficit Hyperactivity Disorder(ADHD). Three children with ADHD, grade 2, 3, 4 were selected to participate in the research. A total of 15 session were given during 8 week time span, including a final performance session. For measurement, Korean-Child Behavior Checklist(K-CBCL), Home Situation Questionnaire-Revised (HSQ-R), Conners Teacher Rating Scale-Revised (CTRS-R) were administered before and after the implementation. Other behavioral checklist were used to record inappropriate or interruptive behaviors. The results showed that violin learning has increased attention span and reduced impulsive behaviors of all three children with ADHD. Along with these changes, the identified inappropriate behaviors reduced as sessions progressed. Also the changes observed within the music environment were generalized to non-music environment, such as family and school. These results also indicate that violin can be a therapeutic medium used in music therapy setting to bring positive changes for children with ADHD problems.

The Effect of Wang-Hong Characteristics on Impulse Buying During Live Sale: Based on Women's Clothing Sales in China (왕홍의 판매 생방송 시청이 충동구매에 미치는 영향: 중국 의류 판매를 중심으로)

  • Liu, Xianya;Park, Jee Yun;Lee, Hye Eun
    • The Journal of the Korea Contents Association
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    • v.20 no.4
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    • pp.212-229
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    • 2020
  • 'Live + Sale' is actively promoted in China and 'Wang-Hong', also known as Chinese internet celebrities are dominating this format of marketing strategy recently. They introduce products to consumers through live broadcasts, promote online shopping, and frequently evoke impulsive buying. Under this context, it is worth focusing on what factors influence impulse buying during Wang-Hong's live broadcast. This study investigated the impact of Wang-Hong characteristics on impulse buying behavior when watching live sales. Also, the mediating role of flow experience and viewing satisfaction was explored. Furthermore, we expected that the different live broadcast circumstances could have a different impact on flow experience, viewing satisfaction, and impulse purchase. A total of 242 Chinese women who have experience of viewing live sales were recruited through a Chinese research platform. The results revealed that Wang-Hong's trustworthiness and attractiveness positively affected the viewer's impulse buying directly, and indirectly through flow experience and viewing satisfaction, whereas expertise did not have any impact on impulse purchase. However, there were no significant differences between the two live broadcast circumstances. This research can enhance understanding of the impulse buying process during Wang-Hong's live sale and help brands come up with effective influencer marketing strategies using live sales.