• Title/Summary/Keyword: Frequency focusing

검색결과 930건 처리시간 0.034초

Impact Analysis of Construction Delay: The Case of Defects In the Top-down Construction Method

  • Suk, Janghwan;Kwon, Woobin;Soe, Jang-woo;Cho, Hunhee
    • 국제학술발표논문집
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    • The 9th International Conference on Construction Engineering and Project Management
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    • pp.213-221
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    • 2022
  • Defects are the risk factors in the construction process of buildings. They cause damage, delaying the construction duration. They especially cause adverse effects on the top-down construction method. This study analyzed the degree of construction delay induced by each work type, focusing on defects in the top-down method. Then, we derived construction delay induction coefficient from different work types in order by using the severity of construction delay per defect and the occurrence probability of defect; this assessment model measures the impact of defects on construction delay for each work type. Furthermore, by comparing each work type based on the defect frequency and the construction delay induction coefficient, we found work types that need to be administered attentively. We identified that plastering work was easy to overlook, requiring caution in defect management. This study provides an efficient defect management system suitable for the buildings that are built using the top-down construction method.

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Labor Vulnerability Assessment through Electroencephalogram Monitoring: a Bispectrum Time-frequency Analysis Approach

  • CHEN, Jiayu;Lin, Zhenghang
    • 국제학술발표논문집
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    • The 6th International Conference on Construction Engineering and Project Management
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    • pp.179-182
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    • 2015
  • Detecting and assessing human-related risks is critical to improve the on-site safety condition and reduce the loss in lives, time and budget for construction industry. Recent research in neural science and psychology suggest inattentional blindness that caused by overload in working memory is the major cause of unexpected human related accidents. Due to the limitation of human mental workload, laborers are vulnerable to unexpected hazards while focusing on complicated and dangerous construction tasks. Therefore, detecting the risk perception abilities of workers could help to identify vulnerable individuals and reduce unexpected injuries. However, there are no available measurement approaches or devices capable of monitoring construction workers' mental conditions. The research proposed in this paper aims to develop such a measurement framework to evaluate hazards through monitoring electroencephalogram of labors. The research team developed a wearable safety monitoring helmet, which can collect the brain waves of users for analysis. A bispectrum approach has been developed in this paper to enrich the data source and improve accuracy.

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Attentional modulation on multiple acoustic cues in phonological processing of L2 sounds

  • Hyunjung Lee;Eun Jong Kong
    • 말소리와 음성과학
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    • 제15권4호
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    • pp.11-16
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    • 2023
  • The present study examines how a cognitive attention affects Korean learners of English (L2) in perceiving the English stop voicing distinction (/d/-/t/). This study tested the effect of attentional distractor on primary and non-primary acoustic cues, focusing on the role of Voice Onset Time (VOT) and fundamental frequency (F0). Using the dual-task paradigm, 28 Korean adult learners of English participated in the stop identification task carried with (distractor) and without (no-distractor) arithmetic calculation. Results showed that when distracted, Korean learners' sensitivity to VOT decreased as priorly reported with native English speakers. Furthermore, as F0 is a primary cue for a L1 Korean stop laryngeal contrast, its role in L2 English voicing distinction was also affected by a distractor, without compensating for the reduced VOT sensitivity. These findings suggest that flexible use of multiple cues in L1 is not necessarily beneficial for L2 phonological processing when coping with a adverse listening condition.

바로서기 동작 시 EEG와 역학변인 간 동작 예측의 탐구 (Exploration of Motion Prediction between Electroencephalography and Biomechanical Variables during Upright Standing Posture)

  • Kyoung Seok Yoo
    • 한국운동역학회지
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    • 제34권2호
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    • pp.71-80
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    • 2024
  • Objective: This study aimed to explore the brain connectivity between brain and biomechanical variables by exploring motion recognition through FFT (fast fourier transform) analysis and AI (artificial intelligence) focusing on quiet standing movement patterns. Method: Participants included 12 young adult males, comprising university students (n=6) and elite gymnasts (n=6). The first experiment involved FFT of biomechanical signals (fCoP, fAJtorque and fEEG), and the second experiment explored the optimization of AI-based GRU (gated recurrent unit) using fEEG data. Results: Significant differences (p<.05) were observed in frequency bands and maximum power based on group and posture types in the first experiment. The second study improved motion prediction accuracy through GRU performance metrics derived from brain signals. Conclusion: This study delved into the movement pattern of upright standing posture through the analysis of bio-signals linking the cerebral cortex to motor performance, culminating in the attainment of motion recognition prediction performance.

A Study on the Personality Types of PMO Leader on Project Performance: Focusing on the Mediating Effects of Positive Psychological Capital

  • Seungwoo NAM
    • 융합경영연구
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    • 제12권4호
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    • pp.77-85
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    • 2024
  • Purpose: The purpose of this study was to investigate the effect of organizational management competency according to the personality types of Project Management Office (PMO) leader on the Project Performance and to further verify the mediating effect of positive psychological capital. Research design, data and methodology: The collected data of this study was statistically checked using SPSS 25.0 program and AMOS 25.0, and the result analysis and hypothesis verification were conducted by applying demographic frequency analysis, descriptive statistics, model fit, reliability, validity, correlation analysis, and structural equation modeling. Results: The personality types of the project Management Office (PMO) leader had an effect on positive psychological capital and positive psychological capital had a mediating effect between project performance. Conclusion: Since the essence of project Management Office (PMO) leadership for organizational management exists in a smooth mutual relationship between the leader and the project members, it is necessary to expand the leadership education that strengthens the positive psychological capital and to manage the communication ability of the PMO leader continuously in terms of personnel management practice.

고주파 열처리 코일과 피가열물 사이 간극에 따른 SCM440 강의 고주파 열처리 특성에 관한 연구 (Study on the High Frequency Heat Treatment Characteristics with the Distance between Coil and SCM440 Parts)

  • 김대완;최지석;한창원;이무연
    • 한국산학기술학회논문지
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    • 제18권10호
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    • pp.1-7
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    • 2017
  • 본 논문에서는 자동차에서 사용되는 부품 중 Sway bar link에 사용되는 볼 스터드의 고주파 열처리 시 고주파 열처리 코일과의 사이 간극에 따른 고주파 열처리 특성에 관하여 연구하였다. 오늘날 세계 완성차 업체는 소비자의 요구와 각 국가의 환경정책에 따라 연비향상 및 배기가스 감축함과 동시에 고성능의 자동차를 개발하기 위하여 많은 연구를 하고 있다. 그러나 고주파 열처리에 대한 대부분의 연구가 실험적으로 이루어지고 있어 특정 제품에 맞는 열처리 조건을 구하기가 매우 어렵다. 이러한 문제로 인하여 본 연구에서는 고주파 열처리 조건 중 고주파 열처리 코일과 피가열물 사이 간극을 제외한 모든 조건은 동일하게 유지하여 열처리를 하고, 표면경도와 유효경화깊이 및 전경화깊이를 측정하여 최적의 고주파 열처리 코일과 피가열물 사이 간극은 1~2 mm 임을 알아내었다. 또한 고주파 열처리 코일과 피가열물 사이 간극이 3 mm 이상일 때는 유효경화깊이 및 전경화깊이의 기준 값을 만족하지 못하였다.

능동소음제어를 이용한 건설현장의 소음관리모델 개발 - 도심지 공사현장을 중심으로 - (The Development of Noise Management Model using Active Noise Control Technique on Construction Site)

  • 권나현;박문서;이현수;안요섭;김선우
    • 한국건설관리학회논문집
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    • 제15권2호
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    • pp.12-22
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    • 2014
  • 건설현장에서 발생하는 소음으로 인하여 많은 사람들이 고통을 겪고 있고, 그로 인하여 민원과 분쟁이 증가하고 있다. 이러한 민원은 사업의 지연 및 중단, 배상액 지불과 같은 시간적, 경제적 손실을 초래하므로 엄격하게 관리되어야 한다. 이와 같은 추세에 따라 정부는 기존 방음벽 중심의 소음정책에서 탈피하여 발생원 중심으로 소음을 관리하기 위해 노력하고 있다. 그러나 건설소음은 일시적이고, 불규칙적으로 발생하며, 건설장비 자체의 소음레벨이 높기 때문에 쉽게 제어되기 어렵다. 또한 최근 선진국을 중심으로 사람들에게 쉽게 인지되지는 않지만, 고주파 소음과 마찬가지로 인체에 정신적, 신체적 피해를 주는 저주파 소음에 대한 연구를 활발히 진행하고 있다. 그러나 기존의 수동적인 소음관리방식으로는 고주파 소음을 저감하는데 효과가 있을 뿐, 저주파 소음을 저감하는데는 한계가 있다. 그러므로 본 연구는 건설현장에서 발생하는 소음을 저감하고, 기존의 수동적인 소음관리방식의 한계점을 보완하기 위한 방법으로 능동소음제어를 이용하여 건설현장에서 발생하는 소음을 저감하기 위한 관리모델을 제안하는 것을 목적으로 한다. 이를 위하여 시뮬레이션 실험을 수행하였고, 능동소음제어의 건설현장 적용성을 검토하였다. 본 논문은 능동소음제어를 통하여 건설현장에서 발생하는 소음을 저감하고, 소음피해로 인한 민원과 분쟁을 최소화하는데 일조할 수 있을 것이라 기대한다.

교류전류를 이용한 새로운 비파괴탐상법의 개발;표면결함과 이면결함의 평가 및 실기 부재의 결함 검출 (Development of the Advanced NDI Technique Using an Alternating Current : the Evaluation of surface crack and blind surface crack and the detection of defects in a field component)

  • 김훈;임재규
    • Journal of Welding and Joining
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    • 제13권2호
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    • pp.42-52
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    • 1995
  • In the evaluation of aging degradation on the structural materials based on the fracture mechanics, the detection and size prediction of defect are very important. Aiming at nondestructive detection and size prediction ol defect with high accuracy and resolution, therefore, an lnduced Current Focusing Potential Drop(ICFPD) technique has been developed. The principle of this technique is to induce a focusing current at an exploratory region by an induction wire flowing an alternating current(AC) that is a constant ampere and frequency. Defects are assessed with the potential drops that are measured the induced current on the surface of metallic material by the potential pick-up pins. In this study, the lCFPD technique was applied for evaluating the location and size of the surface crack and blind crack made in plate specimens, and also for detecting the defects existing in valve, a field component, that were developed by SCC etc. during the service. The results of this present study show that surface crack and blind crack are able to defect with potential drop. these cracks are distinguished with the distribution of potential drop, and the crack depths can be estimated with each normalized potential drop that are parameters estimating the depth of each type crack. In the field component, the defects estimated by experiment result correspond with those in the cutting face of the measuring point within a higher sensitivity.

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융합적 가족 기능과 청소년 보호요인의 매개검증에 관한 연구 (A Study on Convergence Family Function and parameter validation fusion of youth protection factor)

  • 장춘옥
    • 한국융합학회논문지
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    • 제6권4호
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    • pp.121-126
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    • 2015
  • 한국청소년패널(2008)의 중2 패널 5차년도 자료를 가지고 기술통계 분석과 회귀분석을 실시하여 가족의 기능적 결손이라는 위험상황에서 위험요인, 보호요인, 심리적응 간의 관계와 보호요인의 매개효과의 기제를 검증하고, 심리적응 수준이 높은 청소년을 보호해주는 보호요인을 분석하는 데에 그 목적이 있다. 분석방법으로는 대상자의 빈도분석과 개인특성에 따른 차이를 알아보기 위해 PASW(Predictive Analytics Software) 18.0을 이용해 t검증을 실시하였다. 또한 적응에 대한 보호요인의 작용 검증을 위하여 위계적 회귀분석을 실시하여 매개효과를 검증하였다. 연구결과 사회복지실천 현장에서 청소년의 위험요인에 초점을 맞추기보다는 위험요인을 완화시키는 과정이나 보호요인에 초점을 맞춤으로써 위험요인에 노출된 청소년을 바라보는 시각을 전환시킬 수 있으며 이들에 대한 개입도 달라질 것으로 판단된다. 사회복지실천 현장에서 청소년의 위험요인에 초점을 맞추기보다는 위험요인을 완화시키는 과정이나 보호요인에 초점을 맞춤으로써 위험요인에 노출된 청소년을 바라보는 시각을 전환시킬 수 있다. 또한, 가족의 기능적 결손이라는 어려움을 경험하는 청소년을 대상으로 사회복지 실천적 개입 방향을 마련 할 수 있는 기초를 마련한 것으로 판단된다.

Genetic Polymorphism of Plasma Vitamin D-Binding Protein (Gc) in Some Asian Sheep

  • Tsunoda, K.;Doge, K.;Hasnath, M.A.;Rajbhandary, H.B.;Xu, W.;Zhanchiv, T.;Chau, B.L.
    • Asian-Australasian Journal of Animal Sciences
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    • 제11권3호
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    • pp.318-322
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    • 1998
  • Using polyacrylamide-gel isoelectric focusing followed by immunoblotting, genetic polymorphism of plasma vitamin D-binding protein (Gc) was examined in Asian sheep. The Gc polymorphism was revealed in the Khalkhas sheep of Mongolia, consisting of F, S and W variants, and the Yunnan native sheep of China, consisting of F and S variants. In particular, W was a new variant. The V variant detected in European sheep up to now was not observed in these sheep. The Bhyanglung, Baruwal, Kagi and Lampuchhre sheep of Nepal and local sheep of Bangladesh and Vietnam were monomorphic for the S variant. Family data and population genetic data supported the hypothesis that these variants were controlled by codominant alleles. In these Asian sheep, distribution of the $Gc^s$ allele was predominant (0.9571-1) and was seen as well in European sheep (Suffolk, Corriedale, Cheviot and Finnish Landrace) raised in Japan. $Gc^w$ allele was detected only in the Khalkhas sheep with the low frequency of 0.0025. The $Gc^v$ allele was detected in the Suffolk and Corriedale sheep (0.0080 and 0.0682), but not in any of the Asian sheep studied.