• 제목/요약/키워드: Time-Frequency Analysis

검색결과 4,763건 처리시간 0.039초

수문자료가 Neuro-Fuzzy 기법 결과에 미치는 영향 분석 (Analysis of Impact of Hydrologic Data on Neuro-Fuzzy Technique Result)

  • 지정원;최창원;이재응
    • 대한토목학회논문집
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    • 제33권4호
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    • pp.1413-1424
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    • 2013
  • 최근 우리나라에는 집중호우의 발생 빈도가 잦아지고 있다. 집중호우는 단시간에 발생하여 인명과 재산에 직접적인 피해를 주는 특징이 있다. 이러한 이유로 치수에 대한 관심은 점점 높아지고 있으며 정확한 유량 예측을 바탕으로 홍수에 대비할 수 있는 시스템 개발에 대한 연구가 활발하게 이루어지고 있다. 지금까지 홍수 예보에는 주로 물리적 모형이 사용되어 왔다. 물리적 모형은 매개변수 결정을 위해 많은 자료를 필요로 하고 또 매개변수의 결정 과정에서 많은 불확실성을 포함하고 있기 때문에 계산과정을 거치는 동안 다양한 오차가 반복하여 누적되는 단점이 있다. ANFIS는 인공신경회로망과 퍼지기법을 사용한 자료 지향형 모형으로 기존의 물리적 모형에서 사용한 방대한 양의 물리적 자료를 배제하고 유역의 강우자료와 유량자료만을 사용하여 모형을 구축하고 수위를 예측할 수 있다는 장점이 있다. 그러나 자료 지향형 모형은 입력 자료와 결과 사이의 논리적 상관성을 찾을 수 없다는 단점이 있다. 본 연구에서는 ANFIS 모형에 사용되는 함수의 옵션과 입력자료의 특성의 제한적인 변화에 따른 결과자료 분석을 통해 자료 지향형 모형의 특성을 분석하였다. 또한 일반적으로 많이 사용하는 물리적 모형 중 하나인 HEC-HMS의 유출량 산정 결과와의 비교를 통해 ANFIS의 적용성을 평가하였다. 본 연구는 남한강 상류에 위치한 청미천 유역의 2007년부터 2011년까지의 관측 강우자료와 유량자료를 사용하여 수행하였다.

악성 종양 관련 일측성 성대 마비 환자에서 고식적 Hyaluronic Acid 성대 주입 성형술의 유용성 (Benefits of Palliative Office-Based Hyaluronic Acid Injection Laryngoplasty in Cancer-Related Unilateral Vocal Cord Paralysis Patients)

  • 김고운;박영학;주영훈;김상연;심미란;황연신;선동일
    • 대한후두음성언어의학회지
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    • 제29권1호
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    • pp.30-36
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    • 2018
  • Background and Objectives : The effect of palliative injection laryngoplasty in cancer-related unilateral vocal cord paralysis patients on voice and swallowing function is uncertain and there are few previous studies of its suitability, benefits as a palliative treatment option. The purpose of this study is to confirm the objective results of voice and swallowing function after palliative office-based hyaluronic acid injection laryngoplasty in cancer-related unilateral vocal cord paralysis patients. Materials and Method : 36 patients who had unilateral vocal cord paralysis from non-thyroidal, extralaryngeal neoplasms were included in this study. To evaluate the clinical outcome, we analyzed perceptual GRBAS grading, acoustic analysis, aerodynamic study, Electroglottography (EGG), Voice Handicap Index (VHI-30) about voice function and disability rating scale (DRS), gastric tube dependency, aspiration pneumonia about swallowing function and 36-Item Short Form Survey version 2 (SF-36v2) about quality of life. Results : In GRBAS scale, G (p<0.001), R (p=0.004), B (p=0.001), A (p=0.011), and S (p=0.007) showed significant improvement. Jitter, shimmer, speaking fundamental frequency, maximal phonation time, VHI-30, DRS score, gastric tube dependency, aspiration pneumonia, and SF-36v2 were significantly improved after injection (p=0.016, p=0.011, p=0.045, p=0.005, p<0.001, p<0.001 p=0.003, p<0.001, and p<0.001 respectively). Conclusion : From this study we concluded office-based hyaluronic acid injection can be used as a useful palliative treatment option in cancer-related ill patients with unilateral vocal cord paralysis. Palliative hyaluronic acid injection laryngoplasty avoids the need for tube feeding, thus reducing the risk of aspiration pneumonia. These outcomes are accompanied by significant improvement in voice quality.

Prostatic Bleeding after Prostatic Biopsy Effects Oncological Outcomes with Laparoscopic Radical Prostatectomy

  • Takai, Tomoaki;Inamoto, Teruo;Komura, Kazumasa;Tsujino, Takuya;Matsunaga, Tomohisa;Yoshikawa, Yuki;Uchimoto, Taizo;Saito, Kenkichi;Tanda, Naoki;Minami, Koichiro;Uehara, Hirofumi;Ibuki, Naokazu;Takahara, Kiyoshi;Nomi, Hayahito;Kiyama, Satoshi;Azuma, Hayahito
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권3호
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    • pp.1373-1377
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    • 2016
  • Background: We vigorously reviewed patients' operation record who had adhesion of the Denonvilliers' fascia and found out most of these patients had prostatic bleeding after prostatic gland biopsies. We examined the magnitude of prostatic bleeding and frequency after biopsies and the relationship with oncological outcomes. Materials and Methods: A total of 285 patients were selected for the final analyses. Inclusion criteria were as follows: receiving MRI three weeks after biopsiesand laparoscopic radical prostatectomy within 300 days after biopsy. We divided the patients into two groups with (group A) or without (group B) prostatic bleeding. We examined the magnitude of prostatic bleeding after biopsies and the relationship with operation time (OT), positive surgical margin (PSM), biochemical recurrence (BCR) and other factors. Furthermore, we created a logistic-regression model to derive a propensity score for prostatic bleeding after biopsies, which included all patient and hospital characteristics as well as selected interaction terms, and we examined the relationship with PSM and BCR. Results: In all patients, the OT in the group B was shorter than the group A (p < 0.001). Prostatic bleeding was associated with PSM (p=0.000) and BCR (p=0.036). In this propensity-matched cohort, 11 of 116 patients in the group B had PSM as compared with 36 of 116 patients from group A (match-adjusted odds ratio, 4.30; 95%CI confidence interval, 2.06 to 8.96; P=0.000). In addition, eight of 116 patients in group B encountered BCR, as compared with 18 of 116 patients in group A (match-adjusted odds ratio, 2.48; 95%CI, 1.03 to 5.96; P=0.042). Kaplan-Meier analysis in the propensity matching cohort showed a significant biochemical recurrence-free survival advantage for being free of prostate bleeding after biopsies. Conclusions: Our findings in the present cohort should help equip surgeons to pay attention to careful excision especially for those who experienced deferred prostatic bleeding.

카 쉐어링 서비스 특성이 사용자 평가와 순 편익에 미치는 영향 (The Effectiveness of Service Characteristics of Car Sharing on User Evaluation and Net Benefit)

  • 손봉진;최재원;권혁준
    • 한국전자거래학회지
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    • 제23권2호
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    • pp.1-20
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    • 2018
  • 공유 경제의 대표적인 사례 중 하나의 카 쉐어링 서비스는 차량을 공유하여 사용자가 원하는 시간, 장소에서 원하는 만큼 공유하여 사용할 수 있는 서비스를 제공하고 있다. 본 연구에서는 카 쉐어링 서비스의 시스템이 제공하는 기반적 특성인 희소성과, 시스템 품질, 서비스 품질이 사용자의 평가 요소에 영향을 줄 것이라 가정하고 사용자의 평가를 통하여 사용자의 순 편익을 확인하고자 하였다. 분석결과 희소성의 쿠폰과 시간제한은 사용자 평가 요소인 인지된 사회적 지지와 앱 신뢰에 영향을 주었으나 제한 수량은 영향을 주지 않아 카 쉐어링 서비스에서 수량에 대한 제한은 관련 없는 것으로 나타났다. 시스템 품질의 대부분의 변수들이 인지된 사회적 지지와 앱 신뢰에 영향을 주었다. 사용자 평가는 사용자 만족과 추천의도에 영향을 주었다. 사용자가 얻을 수 있는 순 편익으로써 만족감과 조직적 측면에서의 간접적 성과인 추천 의도가 채택되어 순 편익 변수의 역할을 하였다. 공유경제와 관련된 연구는 주로 탐색적 연구에서 국한하는 점으로 비추어 볼 때 본고에서 언급하고 있는 비즈니스 성공 모델의 적용과 사회적 변수 적용 등 실증적으로 분석했다는 점에서 본 연구의 의의가 있다.

TDOA/FDOA 정보를 이용한 Gauss-Newton 기법 기반의 이동 신호원 위치 및 속도 추정 방법과 성능 분석 (Gauss-Newton Based Estimation for Moving Emitter Location Using TDOA/FDOA Measurements and Its Analysis)

  • 김용희;김동규;한진우;송규하;김형남
    • 전자공학회논문지
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    • 제50권6호
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    • pp.62-71
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    • 2013
  • TDOA (time difference of arrival)와 FDOA (frequency difference of arrival)를 동시에 사용하는 신호원 위치추정 방법은 단일 정보를 이용하는 경우에 비해 높은 정확도를 가지며 이동 신호원의 속도 추정이 가능하다는 장점을 가지고 있다. 최근 종속 미지변수를 정의한 후 비반복적으로 해를 구하는 방법들이 제안되고 있으나 전자전 환경과 같이 수신단과 신호원 간의 거리가 상대적으로 먼 경우에는 추정 정확도가 낮고 모든 수신단 쌍이 동일한 기준 수신단을 공유하여야 한다는 운용상의 제약이 존재한다. 따라서 본 논문에서는 비선형 LS 최적해를 반복계산을 통해 얻어내는 Gauss-Newton 기법을 적용하여 이동 신호원의 위치좌표와 속도벡터를 추정한다. 또한 이동 신호원의 위치와 속도 추정 결과를 효과적이고 정량적으로 분석하기 위해 CRLB (Cramer-Rao lower bound) 행렬을 각각의 부공간으로 분해하여 2차원 공간상에 독립된 CEP (circular error probable) 평면으로 도시한다. 모의실험을 통해 주어진 수신단 배치와 조합에서 이동 신호원의 위치 및 속도 추정 성능을 확인하고 분석 결과를 제시한다.

죽산보의 어도에서 트랩 샘플링 기법을 이용한 하절기, 일주기별 어류 이동성 평가 (Summer Patterns and Diel Variations of Fish Movements Using Fish Trap Sampling Technique in the Juksan Weir)

  • 한정호;고대근;임병진;박종환;안광국
    • 환경영향평가
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    • 제21권6호
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    • pp.879-891
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    • 2012
  • The objective of this study was to evaluate seasonal patterns and diel variations of fish movements in the Juksan Weir which was constructed in 2010 at the down-stream of Yeongsan-River watershed. For this study, we monitored day-and-night movement(24 Hr cycle) and seasonal fish migration(June ~ August) patterns in 2011 along with species compositions and abundances depending on the locations of the traps within the fishway. Total number of species sampled was 14 and the total number of individuals was 1,263 with only the size-fractions(as total length) of the fish < 20 cm during the study. Seasonal analysis of fish movement in the fish way showed that highest frequency in the movement occurred in June - July, which is closely associated with a spawning peak season. The most dominant species using the fishway was Squalidus chankaensis tsuchigae, and this species turned out to be 26.9% of the total in the use rate of fishway. Daily monitoring of fish movements showed that most frequent movements occurred between 18:00 PM and 21:00 PM when the fish have a feeding time generally. The migratory fish were not found in the fishway during the study. Mean current velocity during the study $0.42{\pm}0.02ms^{-1}$(n = 42), and there were no significant statistical differences(p > 0.05) among the daily and monthly velocities in the fishway. The use rate of fish passage, in terms of fish species, was 48%, compared with total sampling of fish species(29 species) at the down-river regions during the same period, indicating a low use rate. Further continuous long-term monitoring should be conducted to evaluate the impacts of the weir construction in the river.

지속적인 계단 보행에서 부하가 하지 근육의 생체역학적 변인과 근사 엔트로피에 미치는 영향 (Effects of Loading on Biomechanical Analysis of Lower Extremity Muscle and Approximate Entropy during Continuous Stair Walking)

  • 김성민;김혜리;;신성훈;공세진;김언호;이기광
    • 한국운동역학회지
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    • 제25권3호
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    • pp.323-333
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    • 2015
  • Objective : The purpose of this study was to investigate the changes of gait patterns and muscle activations with increased loads during stair walking. Also, it can be used as descriptive data about continuous stair walking in a real life setting. Method : Twelve sedentary young male adults(Age: $27.0{\pm}1.8yrs$, Weight: $65.8{\pm}9.9kg$) without any lower extremity injuries participated in this study. Participants performed stair walking up 7 floors and their ascending and descending motion on each floor was analyzed. A wireless electromyography(EMG) were attached on the Rectus Femoris(RF), Biceps Femoris(BF), Gastrocnemius(GN), Tibialis Anterior(TA) muscle to calculate integrated EMG(iEMG), median frequency(MDF) and co-contraction index(CI). Chest and left heel accelerometer signal were recorded by wireless accelerometer and those were used to calculate approximate entropy(ApEn) for analyzing gait pattern. All analyses were performed with SPSS 21.0 and for repeated measured ANOVA and Post-hoc was LSD. Results : During ascending stairs, there were a statistically significant difference in Walking time between 1-2nd and other floors(p=.000), GN iEMG between 2-3th and 6-7th(p=.043) floor, TA MDF between 1-2nd and 5-6th(p=.030), 6-7th(p=.015) floor and TA/GN CI between 2-3th and 6-7th(p=.038) floor and ApEn between 1-2nd and 6-7th(x: p=.003, y: p=.005, z: p=.006) floor. During descending stairs, there were a statistically significant difference in TA iEMG between the 6-5th and 3-2nd(p=.026) floor, and for the ApEn between the 1-2nd and 6-7th(x: p=.037, y: p=.000, z: p=.000) floor. Conclusion : Subjects showed more regular pattern and muscle activation response caused by regularity during ascending stairs. Regularity during the first part of stair-descending could be a sign of adaptation; however, complexity during the second part could be a strategy to decrease the impact.

2011 대구세계육상선수권대회 여자 100m 허들 선수들의 운동학적 분석 (Kinematic Analysis of 100-m Women's Hurdlers at IAAF World Championships, Daegu 2011)

  • 류재균;박영진;류지선;김태삼;황원섭;박상균;윤석훈
    • 한국운동역학회지
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    • 제21권5호
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    • pp.541-550
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    • 2011
  • The purpose of this study was to investigate the kinematic characteristics of the $5^{th}$ and $6^{th}$ hurdle clearances during the final of the 100-m hurdles event at the IAAF World Championships, Daegu 2011. To this end, the hurdling motions of the top 4 ranked female hurdlers in the competition were analyzed. A total of 12 cameras were used to record their motions, with a sampling frequency of 120 Hz. The cameras were calibrated using $11{\times}2{\times}1\;m$ control objects that covered all of the lanes ($1^{st}{\sim}8^{th}$ lanes). After analyzing all the data, we arrived at the following results. For the take-off phase, a negative relationship between the take-off time (CT) and athlete's rank was found. In addition, the average distances from the hurdle to take-off (L1) were shown to be 2.23 m and 2.17 m for the $5^{th}$ and $6^{th}$ hurdles, respectively. For the distance from the hurdle to landing (L2), Pearson ($1^{st}$ rank) and Carruthers($2^{nd}$ rank) showed inconsistent patterns whereas Harper ($3^{rd}$ rank) and Porter ($4^{th}$ rank) showed consistent patterns. All althetes revealed similar 3 steps patterns between hurdles, which consisted of a shorter $1^{st}$ step, longer $2^{nd}$ step and shorter $3^{rd}$ step.

소규모 사업장 여성근로자의 우울, 자아존중감과 건강실천행위 (A Study on Depression, Self-esteem and Health Practice of Female Workers in Small Workplace)

  • 한수정
    • 한국보건간호학회지
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    • 제16권2호
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    • pp.454-468
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    • 2002
  • Historically, women's health needs have been viewed primarily as reproductive, and all other health needs have been dealth with without considering their responses to disease and treatment(Strickland & Giger, 1994). It has mostly been through the efforts of women's group, especially health care team, that more recognition has been given to the overall health of women worker in recent years. The purpose of this study was to examine the depression, self-esteem and health practice in order to identify health care strategies to improve health promotion among women workers in small workplace. The consisted of 94 women workers who work at small manufacturing industry. The data were collected from January to February, 2002. The instruments for this study was Rogenburgs self-esteem scale, Zung s depression self-reporting scale and Breslow & Enstrom s health habits scale. The analysis of data were performed with frequency, percentage, t-test, ANOVA. $\chi^2$ test, pearson correlation and multiple regression using SPSS Win 10.1 program. 1. The average depression score was 1.87 which is relatively low and the average self-esteem score was 2.75 which is relatively moderate. The total mean score for health practice was 4. 10(range 0-7) which is relatively high moderately. 2. Health practice had not a statistically significant correlation with depression and self-esteem, but the depression had a statistically significant correlation with self-esteem(r=-.401, p=.000). 3. There was not a significant difference In depression, self-esteem and health practice according to the general characteristics 4. There was a significant difference in sub category of health practice according to the status of living with family and status of marriage. As far as the health practice of women workers living with family practiced better health than women workers no living with family concerning breakfast(p=.03) and as far as the health practice of women workers no living with family practiced better health than women workers living with family concerning sleeping time(p=.04). There was a significant difference in breakfast(p=.04), smoking(p=.00), and BMI(p=.05) according to the status of marriage. 5. The major factor was age and explained for $7\%$ of health practice. The repeated study should be carried out to figure out the health practice and its related factors of female workers at small manufacturing industry.

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문제해결형 탐구실험에서 나타난 영재학생들의 논의 양상 및 논의활동에 대한 인식 (The Gifted Students' View on Argumentation and the Aspects of the Argumentation in Problem-Solving Type Experiment)

  • 신호심;김현주
    • 한국과학교육학회지
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    • 제31권4호
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    • pp.567-586
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    • 2011
  • 이 연구에서는 고등학교 1학년 과학영재들의 문제해결형 탐구실험에서 논의 양상을 확인하고 논의활동에 대한 학생들의 인식을 알아보았다. 그 결과, 매우 활발한 논의활동이 확인되었으나 차시에 따른 논의 질 향상은 거의 나타나지 않았다. 수업 전반에 걸쳐 대화적 논의과정 요소의 빈도가 높게 나타났고 그 중 요청 및 요청응답의 비율이 높았다. 빈도는 낮지만 한정과 근거질문이 3차시에서만 나타났고, 차시에 따라 단순호응이 줄면서 강화 및 정교화, 메타질문의 빈도는 약간씩 높아졌다. 교사가 주도하는 일부 학습 단계에서 학생들의 논의가 거의 발견되지 않는 등 단계별 논의 양상이 교사의 수업 접근 방식과 관련 있음이 확인되었고, '문제해결활동 및 결과분석'에서 이전의 단계보다 2배 많은 논의과정 요소가 나타났다. 또한 집단을 구성하는 방법은 영재 학생들의 논의 활동에 거의 영향을 미치지 않았다. 설문조사 결과, 대부분의 학생들은 본 탐구실험에서 자유로운 논의가 이루어졌다고 생각하였고 논의활동을 직접 경험함으로써 본 프로그램이 논의를 활성화시킨다고 인식하였으며, 이 과정에서 '생소하거나 어려움'이 논의활성화에 저해요인으로 작용됨이 확인되었다. 주제별 논의활동은 '표면성장 실험'에서 가장 활발하게 이루어졌고, 논의가 가장 활발한 단계는 '해결방안모색'으로 나타났다. 교사의 도움이 논의활동의 어려움 해소와 촉진제 역할을 하였음이 확인되었으며 실험수업에서 논의활동이 진행되는 것을 매우 긍정적으로 생각하는 등 논의활동의 필요성에 대한 학생들의 인식이 확인되었다.