• Title/Summary/Keyword: frequency-response

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Multiple Damage Detection of Pipeline Structures Using Statistical Pattern Recognition of Self-sensed Guided Waves (자가 계측 유도 초음파의 통계적 패턴인식을 이용하는 배관 구조물의 복합 손상 진단 기법)

  • Park, Seung Hee;Kim, Dong Jin;Lee, Chang Gil
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.3
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    • pp.134-141
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    • 2011
  • There have been increased economic and societal demands to continuously monitor the integrity and long-term deterioration of civil infrastructures to ensure their safety and adequate performance throughout their life span. However, it is very difficult to continuously monitor the structural condition of the pipeline structures because those are placed underground and connected each other complexly, although pipeline structures are core underground infrastructures which transport primary sources. Moreover, damage can occur at several scales from micro-cracking to buckling or loose bolts in the pipeline structures. In this study, guided wave measurement can be achieved with a self-sensing circuit using a piezoelectric active sensor. In this self sensing system, a specific frequency-induced structural wavelet response is obtained from the self-sensed guided wave measurement. To classify the multiple types of structural damage, supervised learning-based statistical pattern recognition was implemented using the damage indices extracted from the guided wave features. Different types of structural damage artificially inflicted on a pipeline system were investigated to verify the effectiveness of the proposed SHM approach.

Consumer's Behaviors on the Laundering of Baby's Clothing - Comparison of Washing Machine Types - (영.유아복 세탁에 관한 소비자 행동 연구 - 세탁기 유형별 비교 -)

  • Lee, Su-Yeon;Le, Jeong-Sook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.31 no.8
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    • pp.1231-1239
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    • 2007
  • The purpose of this study was to investigate consumer's behaviors on the laundering of baby's clothing according to washing machine types. The subjects were 255 consumers with babies(0-2 years) in Korea. The data were collected with a self-administered questionnaire and analyzed by Chi-square test and multiple response analysis, and SPSS 12.0 statistics package was used. Consumers were separated into two groups according to washing machine types with general pulsator type and drum-type. Consumer's behaviors between general pulsator type group and drum-type group of washing machines were also examined. The results of this study were as follows. In the consumer satisfaction for washing machine, mostly drum-type group of consumers were satisfied with their washing machines. As the reasons of washing machine's dissatisfaction, noise, washing time and low washing efficiency were high in the pulsator type group, and washing time, noise and high price in the drum-type washing machine group. The consumers concerned about separation of clothing and laundering label while they washed laundry by washing machine. However, they didn't separate clothing because the small volume of laundry and a long washing time. The most interest and required thing of consumers was complete rinsing without any detergents used in washing as well as the removal of soils for baby's clothing regardless of two washing machine types. And they complained food soils like milk and mother's milk etc. were not completely removed by washing machine. As a whole the washing frequency of baby's laundry was once per a day and the rinsing also more than three times per a laundry. Most of the consumers used a private detergents for baby's clothing(detergents for baby's clothing only), and preferred to the high or boiled temperature washing as a desirable baby's laundering. There were significant differences between general pulsator type group and drum-type group of washing machines on the laundering of baby's clothing in this study.

Non-uniform Linear Microphone Array Based Source Separation for Conversion from Channel-based to Object-based Audio Content (채널 기반에서 객체 기반의 오디오 콘텐츠로의 변환을 위한 비균등 선형 마이크로폰 어레이 기반의 음원분리 방법)

  • Chun, Chan Jun;Kim, Hong Kook
    • Journal of Broadcast Engineering
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    • v.21 no.2
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    • pp.169-179
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    • 2016
  • Recently, MPEG-H has been standardizing for a multimedia coder in UHDTV (Ultra-High-Definition TV). Thus, the demand for not only channel-based audio contents but also object-based audio contents is more increasing, which results in developing a new technique of converting channel-based audio contents to object-based ones. In this paper, a non-uniform linear microphone array based source separation method is proposed for realizing such conversion. The proposed method first analyzes the arrival time differences of input audio sources to each of the microphones, and the spectral magnitudes of each sound source are estimated at the horizontal directions based on the analyzed time differences. In order to demonstrate the effectiveness of the proposed method, objective performance measures of the proposed method are compared with those of conventional methods such as an MVDR (Minimum Variance Distortionless Response) beamformer and an ICA (Independent Component Analysis) method. As a result, it is shown that the proposed separation method has better separation performance than the conventional separation methods.

Combined utilization with herbal products and prescribed drugs: A result from health examinee-based national survey (일부 종합병원의 건강검진 수검자들의 한약·양약 복합투여)

  • Park, Jong-Ku;Choi, Seo-Young;Koh, Kwang-Wook;Yu, Jun-Sang;Kim, Tae-Hun;Sohn, Dong-Kook;Hong, Ju-Hee;Song, Sung-Eun;Kim, Chun-Bae
    • Health Policy and Management
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    • v.16 no.1
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    • pp.1-16
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    • 2006
  • Recently, there has been prevailing of the combined utilization (CU) with herbs and prescribed drugs in medical therapies in the world. But the information about frequency, efficacy and safety of this CU has not well known in Korea, yet. This study aimed to identify the status of CU by Koreans, and to inquire which side effects of CU represent to those people. A self-completed questionnaire survey was performed through each health examination center in twenty general hospitals and one oriental hospital. Of the initial 2,100 health examinees, 1,851 were participated in this survey, resulting in a response rate of 88.1%. The proportion of CD was 26.3%. The most commonly mentioned reason of CD was 'to promote general health and well-being' (17l persons, 35.5%). The main route of taking CD was self-purchase at drugstore or at herbs market, followed by the prescription of (oriental)physicians. 33.0% (151 persons) of those who took the CD rated it as effective. 93 respondents (19.8%) were experienced several adverse effects including nausea, fatigue, and dizziness. The growing simultaneous use of herbal products and pharmaceutical drugs by Korean consumers may be continuously increased the risk of herb-drug interactions. The medical professionals should be provided with comprehensive and up-to-date information about potential benefits and risks of herbs and prescribed drugs. In the future studies it may be recommended to deal common cold, health promotion, indigestion, headache, and hypertension for the effect and safety of the CD by well-organized prospective study design.

Effect of Participation in Regular Leisure Sports on Satisfaction with Family Relationship in Adolescents (청소년의 규칙적인 여가스포츠 참여가 가족관계 만족도에 미치는 영향)

  • Cho, Hyungsun;Hwang, Sunhwan;Bang, Shinwoong
    • The Journal of the Korea Contents Association
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    • v.15 no.11
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    • pp.591-602
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    • 2015
  • The purpose of this study was to examine the effect of participation in regular leisure sports on satisfaction with family relationship in adolescents. To achieve this purpose, 650 students of elementary and middle schools in Seoul and Gyeonggi area were selected and surveyed using the purposive sampling method. 611 survey samples were used in final analysis and 39 survey samples were excluded because of untrustworthy response. Statistical program AMOS 18.0 was used to conduct the confirmatory factor analysis and goodness of fit test, and SPSS 21.0 Window program was used to conduct analysis of frequency, t-test, and ANOVA. Through the analysis, the main findings were as follows; First, it was found that the adolescents participating in regular leisure sports has significant difference in satisfaction with family relationships compared to non-participation group. Second, satisfaction with family relationship of parental participation group in regular leisure sport was high the most followed by lonely participation group and non-participation group. Finally, authors described the implications and future studies.

Evaluation of Van Khan Tooril's castle, an archaeological site in Mongolia, by Ground Penetrating Radar (GPR을 이용한 몽고 유적지 반 칸 투리일의 성 (Van Khan Tooril's castle)의 평가)

  • Khuut, Tseedulam;Sato, Motoyuki
    • Geophysics and Geophysical Exploration
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    • v.12 no.1
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    • pp.69-76
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    • 2009
  • We report an implementation of the Ground Penetrating Radar (GPR) survey at a site that corresponds to a ruined castle. The objective of the survey was to characterise buried archaeological structures such as walls and tiles in Van Khan Tooril's Ruin, Mongolia, by 2D and 3D GPR techniques. GPR datasets were acquired in an area 10mby 9 m, with 10 cm line spacing. Two datasets were collected, using GPR with 500MHz and 800MHz frequency antennas. In this paper, we report the use of instantaneous parameters to detect archaeological targets such as tile, brick, and masonry by polarimetric GPR. Radar polarimetry is an advanced technology for extraction of target scattering characteristics. It gives us much more information about the size, shape, orientation, and surface condition of radar targets. We focused our interpretation on the strongest reflections. The image is enhanced by the use of instantaneous parameters. Judging by the shape and the width of the reflections, it is clear that moderate to high intensity response in instantaneous amplitude corresponds to brick and tiles. The instantaneous phase map gave information about the location of the targets, which appeared as discontinuities in the signal. In order to increase our ability to interpret these archaeological targets, we compared the GPR datasets acquired in two orthogonal survey directions. A good correlation is observed for the alignments of reflections when we compare the two datasets. However, more reflections appear in the north-south survey direction than in the west-east direction. This is due to the electric field orientation, which is in the horizontal plane for north-south survey directions and the horizontally polarised component of the backscattered high energy is recorded.

Survey on the Knowledge Level of Oral Health and Prevention Behaviors of some College and University Students (일부 대학생의 구강건강지식도 및 예방행태에 관한조사)

  • Park, Hong-Ryurn;Moon, Sun-Jung
    • Journal of dental hygiene science
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    • v.9 no.5
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    • pp.485-490
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    • 2009
  • The purpose of this study was to obtain basic data for improvement about oral health education, contents and method for college and university students. A question was used 10 questionnaire by 332 college and university students in the Tae gu-city and Gu mi-city. In conclusion, 1. They answered that dental caries cause is 'No-brushing'(88.3%). The man respondents answered that the cause of periodontal disease is 'weak disease'(39.2%). 2. The reason about visit to dental clinic is 'for treatment'(72.0%) and they answered that the tooth is 'very important in their life'(82.5%). 3. They answered that the frequency of tooth-brushing is 'two times in a day'(44.8%) and using auxiliary oral hygiene material is 'dental floss' by male(15.2%) and female(16.6%). 4. In the case of high oral health knowledge level showed high response rate about level of oral health attitude and oral health recognition.

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Wavelength Interrogation Technique for Bragg Reflecting Strain Sensors Based on Arrayed Waveguide Grating (도파로 어레이 격자를 이용한 광섬유 브래그 스트레인 센서의 반사파장 신호 복원 기술)

  • Seo, Jun-Kyu;Kim, Kyung-Jo;Oh, Min-Cheol;Lee, Sang-Min;Kim, Young-Jae;Kim, Myung-Hyun
    • Korean Journal of Optics and Photonics
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    • v.19 no.1
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    • pp.68-72
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    • 2008
  • Fiber-optic strain sensors based on Bragg reflection gratings produce the change of reflection spectrum when an external stress is applied on the sensor. To measure the Bragg reflection wavelength in high speed, an arrayed waveguide grating device is incorporated in this work. By monitoring the output power from each channel of the AWG, the peak wavelength corresponding to the applied strain could be obtained. To enhance the accuracy of the AWG wavelength interrogation system, a chirped fiber Bragg grating with a 3-dB bandwith of 5.4 nm is utilized. The high-speed response of the proposed system is demonstrated by measuring a fast varying strain produced by the damped oscillation of a cantilever. An oscillation frequency of 17.8 Hz and a damping time constant of 0.96 second are obtained in this measurement.

Research on Sex Education of Young Children's Mothers (유아 어머니의 자녀 성교육 실천정도)

  • Guem, Sun-Hee;Kim, Myung-Hee;Kang, In-Soon
    • Korean Parent-Child Health Journal
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    • v.8 no.1
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    • pp.49-63
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    • 2005
  • Purpose: The present study is a descriptive research on the content of sex education conducted at home by the mothers of young children who are attending five kindergartens located in Busan, Korea. This study aims to provide basic materials for systematic sex education at home and in the school. Method: Based on the literature review and prior researches, the writer made a questionnaire consisting of 30 items regarding necessities, contents and difficulties of sex education. The 307 questionnaires were collected out of 480 which were distributed by the kindergarten teachers. Data was analysed with frequency and percentage using the SPSS Win 10.0 Program. The main subjects of the study were mothers in their thirties, who understood the necessity of sex education. However, they were lack of enough sexual knowledge in accordance with the transforming sexual culture and lack of suitable materials. They did not plan to educate their children according to their developmental stages, but just taught them verbally rather than using common materials for the situation. Result Regarding the origin of life that children often asks, mothers did not give a scientific and correct response to satisfy their curiosity about sex, saying that a baby was created after marrying a loved one. While more mothers than the prior research responded correctly to the queries of the path of delivery, some mothers did not. It may cause some children to suppress the questions, which may result a distorted sexual knowledge. That is because mothers understood that sex education was to deliver sexual knowledge, but not realized that sex education was a human education carried out throughout life. Mothers fell short of sexual knowledge, capability, and confidence, comparing with swift social changes and children's capacity. As a result, it is necessary to inspire sexual awareness into mothers and educate them through training. It is also needed to secure a training program similar to a teacher training program. Conclusion: It is essential to develop and to provide evaluation tools as well as proper materials in accordance with the children's developmental stage, so that organic management system among home, education institute and society must lead sex education Further, it is necessary to provide teaching methods and materials to mothers regularly, so that the school and home may conduct sex education together to cope with difficulties.

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Differential Response to Joint Attention in Children with Autism Spectrum Disorder Depending on the Level of Attentional Cues (주의 단서 수준에 따른 자폐 범주성 장애 아동의 공동주의집중 반응 연구)

  • Yoo, Ga Eul
    • Journal of Music and Human Behavior
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    • v.11 no.1
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    • pp.21-37
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    • 2014
  • The significant role of joint attention in the development of children with autism spectrum disorder (ASD) has highlighted the importance of early intervention. With the emphasis on the effective cueing and reinforcer for orienting to social stimuli in improving responding to joint attention (RJA) of children with ASD, the use of musical cue was hypothesized. This study aimed to examine the occurrence of RJA behaviors depending on the attentional cue, which differed in the level of information and type of auditory modality. Nine children with ASD participated in this study. The use of eight different joint attention cues were analyzed in terms of the frequency and accuracy of RJA behaviors elicited. The results of the study showed that RJA behaviors occurred more frequently with musical cues than with verbal cues and the mean accuracy rate of RJA was higher with musical cues (p = .047). Musically delivered eliciting and directing cues accompanied with pointing elicited the highest attentional shift and RJA accuracy. The significant increases in RJA with the use of musical cues indicated that incorporating musical elements into an attentional cue may provide more accurate cue information, enough to improve RJA behaviors of children with autism.