• Title/Summary/Keyword: Time-frequency correlation

Search Result 875, Processing Time 0.036 seconds

Output-Only System Identification and Model Updating for Performance Evaluation of Tall Buildings (초고층건물의 성능평가를 위한 응답의존 시스템판별 및 모델향상)

  • Cho, Soon-Ho
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.12 no.4
    • /
    • pp.19-33
    • /
    • 2008
  • Dynamic response measurements from natural excitation were carried out for 25- and 42-story buildings to evaluate their inherent properties, such as natural frequencies, mode shapes and damping ratios. Both are reinforced concrete buildings adopting a core wall, or with shear walls as the major lateral force resisting system, but frames are added in the plan or elevation. In particular, shear walls in a 25-story building are converted to frames from the 4th floor level downwards while maintaining a core wall throughout, resulting in a fairly complex structure. Due to this, along with similar stiffness characteristics in the principal directions, significantly coupled and closely spaced modes of motion are expected in this building, making identification rather difficult. By using various state-of-the-art system identification methods, the modal parameters are extracted, and the results are then compared. Three frequency-domain and four time-domain based operational modal identification methods are considered. Overall, all natural frequencies and damping ratios estimated from the different identification methods showed a greater consistency for both buildings, while mode shapes exhibited some degree of discrepancy, varying from method to method. On the other hand, in comparison with analysis results obtained using the initial finite element(FE) models, test results exhibited a significant difference of about doubled frequencies, at least for the three lower modes in both buildings. To improve the correlation between test and analysis, a few manual schemes of FE model updating based on plausible reasons have been applied, and acceptable results are obtained. The advantages and disadvantages of each identification method used are addressed, and some difficulties that might arise from the updating of FE models, including automatic procedures, for such large structures are carefully discussed.

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

  • Sohn, Bongjin;Choi, Jaewon;Kwon, Hyuk-Jun
    • The Journal of Society for e-Business Studies
    • /
    • v.23 no.2
    • /
    • pp.1-20
    • /
    • 2018
  • Car Sharing Service is provided with sharing the vehicleas you can use it anywhere and anytime. The paper verified the factors impact between providing infrastructure characteristics such as scarcity, system quality and service quality and user evaluation factors based on DeLone & McLean IS Success Model. User evaluation factors have an influence on net benefit. D&M IS model mainly proved inner organization impact. The research collected experienced car sharing service, we analyzed the 224 respondents. The result of the hypothesis follows. The scarcity of time is negatively related to perceived social support and app trust. Provisional coupon is positively related to perceived social support and app trust. But, scarcity of quantity is not related to user evaluation factors. Most of the system qualities are related to app trust, however, privacy concern isn't related to app trust. the paper's demographic characteristic is lack of experience frequency. User evaluation factors that are perceived social support and app trust are positively related to user satisfaction and WoM intention. User satisfaction is individual impact and WoM intention is organization impact. Two factors are the net benefit in car sharing service. The area of sharing economy should more study about correlation among experimental various factors. Thus, the paper has different significant from antecedent research. because of trying to experimental analysis.

Influence of Honeybees Pollinationon Soybean Yield and Yield Components (꿀벌 수정작용이 콩수량 및 수량 구성요소에 미치는 영향)

  • 심용구;최영연
    • Korean journal of applied entomology
    • /
    • v.32 no.3
    • /
    • pp.271-278
    • /
    • 1993
  • This experiment was carried out to elucidate the mfluence of honeybees pollinatIOn on yield and YIeld components of soybean at the Kyungbuk Provincial Rural Development Administration from 1990 to 1991. SIX soybean varieties were cultivated in net houses with and without bees. Italian honeybees(Apis melhfem L.) were used. The Vlsiting frequency of bees in net house wIth bees was 58% higher than that of field honeybees, and it was the highest at 10 A.M. during a day. Number of pods per plant and podding ratio of soybean were higher with bees compared with Wlthout bees, especially for the varieties Paldalkong and Dankyongkong. The number of seeds per pod was not significantly different between with bees and without bees, although the percentage of three seeded pod of varieties Danyeobkong and Muhankong and one seeded pod of varieties Hwangkeumkong and Milyangkong 'was increased. The percentage of three seeded pod of Paldalkong and Dankyeongkong, however, was decreased with bees compared with without bees. At the same time no varietal difference was found in two seeded pods between with bees and without bees. Yield of soybeans was increased 0 to 12 % with bees compared with that of without bees. Yield increase was the hIghest in Paldalkong and Dankyongkong. The ratIO of soybean hybrid plant was mcreased with-bees compared with that of without-bees, especially m Paldalkong and Dankyongkong. A negative correlation was found between the ratio of hybrid plant and the duration of flowering in soy¬beans.

  • PDF

Analysis of Design Status by Type at Display Store of Regional Agricultural Products: Focusing on the Survey of Farming Suppliers' Attitude and Site Examination of Rural Tourism Village (농특산품 전시판매장 디자인 현황 분석 및 유형별 분석 - 농촌관광마을 현장조사 및 농업인 공급자 의식조사를 중심으로 -)

  • Jin, Hye-Ryeon;Chae, Hye-Sung;Kang, Ga-Hye;Jo, Lok-Hwan
    • Journal of Korean Society of Rural Planning
    • /
    • v.19 no.3
    • /
    • pp.13-24
    • /
    • 2013
  • With the increase of visitors to rural tourism villages, the direct selling at sites is getting vitalized. Accordingly, their display stores is getting more important. Therefore, this study has selected 30 domestic rural tourism villages as study objects for the attitude survey of 200 farming suppliers and the site examination for the designs of those display stores in order to analyze their status and classify the types of necessity. Such operation status as sale item, sale method, method of supply and demand, major customer, sales scale, manager, opening hour, and operation cost were examined, to identity and for design factors the pattern, material quality and color were investigated. For the attitude of farming suppliers, the tactics of sales, the reason for being positive or negative, the functionality and the features of display stores were examined through brainstorming. IBM SPSS Statistics 20 Program was employed for Frequency, which indicated that village chiefs and store managers with the sales scale of 1 to 20 million won are dealing with female customers in their 40's and 50's and that those stores are open at the time of experience or year round without any operation expense. Permanent type and Fixed type were found to be the design factors of the display-case type with the material and the color of wood and orange respectively. The result of investigation analysis of farming suppliers' attitude showed the followings: the need of display stores is quite high, structure type and permanent type have high fitness and from the viewpoint of display-on-table type as a standard moving type was very convenient. The analysis of significant items at the characteristics of those display stores revealed that their locations, quality conservation, sanitation, users' convenience, designs and promotion are very important. The result of status analysis revealed that though there is a correlation among the types of display stores depending on the visiting season of tourists their installing is not desirable. Three types have been analyzed: Type 1 is a structure type only in the villages with continuous visitors, Type 2 a moving-table type only in the villages with temporary visitors and Type 3 is a fixed display-case type.

The industrialization and the change of social structure of the traditional rural villiage in the Seoul Metropolitan suburbs (서울 近郊 傳統 農村의 變化)

  • ;;Jung, Bu-Mai;Choi, Ki-Yeop
    • Journal of the Korean Geographical Society
    • /
    • v.29 no.3
    • /
    • pp.340-359
    • /
    • 1994
  • This study intends to describe the characteristics of the transformation of the rural society by tracing the changing social and economic processes of traditional clan villiage (Yeolmi-ri, Silchon-myeon, Kwangju-gun, Kyunggi-province) in the suburbs of Seoul Metropolitan Area. Rural society has experienced serious change of the social structure by the ever expanding urbanization and industrialization since 1960's. The suburbs of Seoul Metropolitan Area is the representative case area of such transformation. This study analyzed various chracteristics of population structure of a villiage, the processes of residential movement and the occupational shift of each household of the villiage in terms of household's life-history collected by interviewing with each household. And the whole households of a villiage is divided by two groups of the native clan group and the non-dan in-migrant group. The results of this study are summarized as follows. 1) This villiage is located within a lineal distance of 40km and a time distance of about 30 to 40 minutes, adjoined dy the Joongbu(중부) national highway, the Kyungchoong (경충) industrial road, the local road between Yangpyuna(양평) and Gonjiam(곤지암) and having a advantageous iocational linkage to Seoul capital city. 2) It is a typical traditional dan villiae constituted of dan family Gu(구) one of whose ancestors had appointed to the prime minister of Chosun Dynasty, and until 1979, 56 out of 60 families of the villiage households were clan families. 3) Since 1979, as the villiage invaded by the out-movement of the small scale manufacturing industries from Seoul capital city, labours moved in this vallige from outside and increased villiage size up to 203 households in 1993, consequently the constitutional proportion between the native clan group and the non-clan in-migrant group was reversed up to 28% vs 72% deepening the sociological heterogeneity. 4) Because of the small scale of industries in this villiage and the vicinity with the city of Seoul, the population turnover of this villiage is very high. The turnover frequency is firstly high within same administrative district of gun(군) level and secondly high between this villiage and the city of Seoul. Thus short-distance movement is identified. 5) There is a close correlation between the residential movement and the occupational shift. The most numbers of non-farm native group have the experiences of migration while the members of native farming group don't shift both the job and the place of residence. The inmigrant group had several migration experiences but few occupational shifts. Thus occupatioanl shift is high for the native group while residential shift is high for the in-migrant group. It is concluded that the change proceeded in Metropolitan suburbs was not directed to form the traditional rural village as 'gesund Gebiet' with respect to the ballance among the economic, cultural and environmental adequency.

  • PDF

Analysis of Hydraulic Characteristics of Flood Plain Using Two-Dimensional Unsteady Model (2차원 부정류 모형을 이용한 둔치의 수리특성 분석)

  • Ku, Young Hun;Song, Chang Geun;Kim, Young Do;Seo, Il Wo
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.33 no.3
    • /
    • pp.997-1005
    • /
    • 2013
  • Since the cross-sectional shape of the Nakdong river is compound type, the water stage rises up to the top of the flood plane, as the flow discharge increases during the extreme rain storm in summer. The recent increase of rainfall intensity and flood frequency results in the immersions of parks and hydrophilic facilities located in the flood plain. Therefore it is necessary to analyze the hydraulic characteristics evolved by the extreme rain storm in the flood plain. The study reach ranging from the Gangjeong Goryeong Weir and the Dalseong Weir, where several hydraulic facilities are located along the channel, was selected and numerical simulations were conducted for 42 hours including the peak flood of the typhoon Sanba. The 2-D transient model, FaSTMECH was employed and the accuracy of the model was assessed by comparing the water level between the simulation results and the measured ones at a gauging station. It showed a high correlation with $R^2$ of 0.990, AME of 0.195, and RMSE of 0.252. In addition, the inundation time, the inundation depth, the inundation velocity, and the shear stress variation in the flood plain facilities were analyzed.

Pattern of Computer Game Play and Emotional and Behavioral Characteristics in Upper Grade Elementary School Children (초등학교 고학년 아동의 컴퓨터 게임 양상과 정서 및 행동 특성)

  • Lee, Ja-Yeong;Park, Tae-Won;Lee, Moon-Sook;Cho, Eun-Cheong;Chung, Young-Chul;Hwang, Ik-Keun;Yang, Jong-Chul;Chung, Sang-Keun;Jung, Ae-Ja;Eun, Hong-Bae
    • Anxiety and mood
    • /
    • v.4 no.2
    • /
    • pp.135-141
    • /
    • 2008
  • Objective : The purpose of this study was to investigate the relationship between the pattern of computer game play and emotional and behavioral characteristics of 5th and 6th grade elementary school children in Jeonju city. Methods : Fifth and sixth graders from two elementary schools (N=413, M=214, F=199) were chosen to participate in this study. The participants completed self-report questionnaires designed by the authors, and were also evaluated based on a computer game addiction scale, state-trait anxiety inventory for children, children's depression inventory and Piers-Harris children's self-esteem scale. The parents of the participants determined the disruptive behavior rating scale of the participants. Results : Positive links were reported between the pattern of computer game play (years of computer game experience, average length of each computer game play session, average time spent on computer game play per day, and average frequency of computer game play per week) and scores of computer game addiction scale. In addition, significant correlation was found between the internalized problems of children (trait anxiety, state anxiety, depression, and self-esteem), and computer game addiction scale score, among both sexes (p<0.01). There were significant correlations between game addiction scale score and inattention (p<0.01) as well as total attention deficit hyperactivity disorder (ADHD) score (p<0.05) in girls. Conclusion : Our findings suggest that computer game addiction is related to symptoms of internalizing, particularly to the trait anxiety. Significant positive correlations between game addiction scale score and externalized behavioral problems were found only in girls.

  • PDF

A Study on the Mode Change Technique of Intelligent Above-Knee Prosthesis Based on User Intention Capture (지능형 대퇴 의족 사용자의 의도 검출을 통한 제어 모드 변경 기법에 관한 연구)

  • Shin, Jin-Woo;Eom, Su-Hong;You, Jung-Hwun;Lee, Eung-Hyuk
    • Journal of IKEEE
    • /
    • v.24 no.3
    • /
    • pp.754-765
    • /
    • 2020
  • Currently, Intelligent femoral prostheses that support the corresponding mode in walking and specific movements are being studied. Certain controls such as upstairs, sitting, and standing require a technique to classify control commands based on the user's intention because the mode must be changed before the operation. Therefore, in this paper, we propose a technique that can classify various control commands based on the user's intention in the intelligent thigh prosthesis system. If it is determined that the EMG signal needs to be compensated, the proposed technique compensates the EMG signal using the correlation between the strength and frequency components of the normal EMG signal and the muscle volume estimated by the pressure sensor. Through the experiment, it was confirmed that the user's intention was accurately detected even in the situation where muscle fatigue was accumulated. Improved intention detection techniques allow five control modes to be distinguished based on the number of muscle contractions within a given period of time. The results of the experiment confirmed that 97.5% accuracy was achieved through muscle tone compensation even if the strength of the muscle signal was different from normal due to muscle fatigue after exercise.

Relationships between Health, Depression, Memory Self-Efficacy and Metamemory in Adults (성인의 건강, 우울, 기억, 자기효능과 메타기억과의 상관관계 연구)

  • Kim, Jeong-Hwa;Kang, Hyun-Sook
    • The Korean Journal of Rehabilitation Nursing
    • /
    • v.1 no.1
    • /
    • pp.61-71
    • /
    • 1998
  • Defining prediction variables related to metamemory for the adults in aging process has worthwhile meaning from the perspective that the produced results can be helpful to reducing the difficulty of memorizing efforts and it can also enhance quality of life of aged. This study attempted to analysis relationship between perceived health status, depression, memory self-efficacy and meta memory for the subjects of middle age and old age adults. This study was designed by adopting descriptive correlational analysis method for the 468 middle and old age adults who are living in Seoul. Samples were selected by convenience sampling. Data collection was done over 1 month period in june 1998. The instruments used in this study were health status measuring scale including depression measuring scale, memory self efficacy measuring scale and metamemory measuring scale which were verified for reliability. Data collected were analized by using SPSS for frequency, Peason correlation, t-test and ANOVA according to the variables character and the study purposes. Results of the study were as follows. 1. Relationship between perceived health status, depression, memory self-efficacy and metamemory. Relational analyses between perceived health status, depression, memory self-efficacy and metamemory supported the hypotheses of 1st, 2nd and 3rd(p < .01). These results suggested that the aged perceived great health status then their memory self-efficacy, and metamemory showed the high scores. In the case of depression when its level became decreased metamemory was inclined to increased. Thus, it is identified that strong relationship exists between these variables. 2. Perceived health status, depression, memory self-efficacy by subject's general characteristics. Scores of perceived health status were high in the group of man compared to the group of women, and also highly educated group showed great perceived health status. Group of persons having occupation showed high score of perceived health status and low depression score. The score of memory self-efficacy and metamemory showed higher in the middle aged than the old aged. The high scores of memory self-efficacy and metamemory were found in the group of highly educated people and who have continuing education. The high scores of memory self-efficacy were found in the group of persons having their job and high metamemory scores found in the group of persons having religion. In summary, the greater perceived health status and memory self-efficacy, the more metamemory scores were likely increased and the more depression level was decreased, the more metamemory was likely increased. Also it was found that general characteristics like educational level, continuing education and religion influenced the metamemory of the aged. Therefore, prevention the aged from getting depression and activation of health promotion are needed to delay time of memory loss.

  • PDF

A study on the state of oral care among some special school personnels (일부 특수학교 교직원의 구강관리실태)

  • Park, Chung-Soon;Lee, Seon-Ok
    • Journal of Korean society of Dental Hygiene
    • /
    • v.11 no.5
    • /
    • pp.659-670
    • /
    • 2011
  • Objectives : The purpose of this study was to examine the state of oral health care among special school personnels in an attempt to provide some information on the improvement of the oral health care of students with disabilities who would be under the first hand influence of school personnels. Methods : The subjects in this study were personnels who were selected by random selection in five different special schools located in the city of Jeonju, North Jeolla Province. A self-administered survey was conducted in person from July 5 to 14 after the purpose of this study was explained. Results : 1. Concerning their general characteristics, the level of oral health knowledge was high in the personnel whose career is 5 years more, and the younger personnels had a better oral health knowledge, and the men were more knowledgeable than the women. 2. As to oral health education experience, the rate of the respondents who ever received oral health education stood at 35.3 percent. In relation to the frequency of oral health education, the biggest group that accounted for 58.2 percent received that education once. As for the route of education, the largest group that represented 52.7 percent received that education at dental hospitals or clinics. In relation to satisfaction with oral health education, the greatest group that accounted for 38.5 percent were dissatisfied with that education. 3. As for an intention of receiving oral health education in the future, the biggest group that accounted for 60.9 percent intended to receive that education if they would have free time, and the largest group that represented 47.7 percent believed that oral health education should be conducted by dental hygienists. 4. Concerning their general characteristics, the level of oral health promotion behavior according to age in both bushing and supplies of oral health care was high in forties-1.89 point and 3.33 point, and that in regular visit to a dental clinic was the highest in twenties for 2.58 point, and that in dietary control was the highest in twenties for 2.59 point. 5. Their oral health knowledge had a significant positive correlation to their toothbrushing, regular dental clinic visit and dietary control that were the subfactors of oral health promotion behavior. 6. As for the impact of oral health promotion behavior on oral health knowledge, toothbrushing exerted the greatest influence on that(${\beta}$=0.306, p<0.001). Conclusions : Appropriate institutional measures should be taken to let dental hygienists who are expert in oral health care provide incremental oral health care for students and adults with disabilities in educational institutions and facilities for the disabled, and the development of oral health education programs is urgently required to offer systematic oral health education for not only students with disabilities but their teachers and guardians.