• Title/Summary/Keyword: Time study

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Development of a Signal Optimization Algorithm at Isolated Intersections Using Vehicle Arrival Models (차량의 도착모형을 이용한 독립교차로 신호최적화알고리즘 개발)

  • Woo, Yong-Han
    • Journal of the Korean Society of Industry Convergence
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    • v.4 no.1
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    • pp.41-49
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    • 2001
  • This study developed signal optimization algorithm by analyzing vehicle arrival patterns. The major principle of signal optimization is dissipate all queueing vehicle in 1cycle and assign delay time uniformly for all approaches. For this, this study used optimal green time and surplus green time. Optimal green time calculated by estimated traffic volume from vehicle arrival model. Surplus green time defined as the gap of optimal green time and queue dissipated time. And alternative cycle has minimum surplus green time was selected as the optimal cycle. Finally, total delay and average delay per vehicle can be calculated by using queueing theory.

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Estimation of the Setting Time of the Super Retarding Concrete Combining Mineral Admixtures (혼화재를 조합 사용한 초지연 콘크리트의 응결시간 추정)

  • Han, Min-Cheol
    • Journal of the Korea Institute of Building Construction
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    • v.8 no.3
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    • pp.111-117
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    • 2008
  • This study provides the setting time prediction method of super retarding concrete incorporating mineral admixtures at the same time including fly ash(FA), blast furnace slag(BS) based on maturity method. The setting time was retarded, as super retarding agent contents increase and curing temperature decreases. In addition, apparent activation energy by Arrhenius function was ranged from $24{\sim}35KJ/mol$ with slightly difference along with mixture proportion. This value is smaller than existing value $30{\sim}50KJ/mol$. It is Indicated that equivalent age using setting time can be a proper method to predict setting time and it also exhibited comparable relativity between prediction value and measurement value. Therefore, this study provided setting time prediction value with super retarding agent contents and mineral admixture combination. Setting time prediction equation provided herein is possibly valid for estimating precise setting time of the super retarding concrete at the job site.

Effects of Curculiginis Rhizoma on anti-thrombotic activity (선모(仙茅) 열수(熱水) 추출물(抽出物)의 항혈전(抗血栓) 효능 연구)

  • Roh, Seong-Soo
    • The Korea Journal of Herbology
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    • v.26 no.4
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    • pp.125-132
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    • 2011
  • Objectives : An aim of study is to investigate effects of curculiginis rhizoma in vitro (factor Xa (FXa) inhibitor assay, prothrombinase assay, prothrombin time (PT) assay, activated partial thromboplastin time (aPTT) assay) and in vivo experiment (blood clotting time, thromboxane B2 content assay in serum and weight of thrombus by AV-shunt rat model). Methods : We gained a human serum and used serum in vitro study such as factor X activity (FXa) inhibition, prothrombinase inhibition, prothrombin time (PT) and activated partial thromboplastin time. Fifteen SD rats were divided into three groups (intact control group and two experimental group treated with extract of Curculiginis Rhizoma(ECR)). Rats were orally administrated DW (intact control group), 600 mg/kg concertration of ECR and 200 mg/kg concertration of ECR. After one hour, we anesthetized rats and made arteriovenous (AV) shunt rat models to study weights of thrombus, took a hole blood to study content of thromboxane B2 and blood clotting time. Results : In vitro, ECR increased a inhibitory activity of FXa, prothrombinase and aPTT compared than intact control group. Especially ECR made significant increase of FXa and prothrombinase inhibitory activity (p<0.05, p<0.01). And PT were increased in ECR control group compared with intact control group. In vivo, a blood clotting time of experiment group treated with ECR 600 mg/kg were significantly increased compared with that of intact control group (p<0.05) and content of thromboxane B2 was significantly decreased in group treated with ECR 600 mg/kg in seum. The weight of thrombus were significantly reduced in group treated with ECR 600 mg/kg compared with intact control group (p<0.05). But in vivo experiment study, those of group treated with ECR 200 mg/kg were reduced compared with those of intact control group without statistical significance. Conclusions : ECR has a antithromboic activity in internal course with inhibitory activity of FXa and prothrombinase in vitro, it required to research more study for effective compounds.

The Effects of Paid Work Time Desynchronization on Dual-Earner Couples' Division of Household Labor (유급노동 시간대 비동기화가 맞벌이 부부의 가사분업에 미치는 효과)

  • Joo, Ik Hyun
    • Journal of Family Resource Management and Policy Review
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    • v.24 no.3
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    • pp.19-33
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    • 2020
  • The purpose of this study was to investigate whether paid work time desynchronization affected housework time desynchronization. Time slot data from the Korean Time Use Survey data from 2014 was analyzed. This study included 1,475 married couples aged 20 to 59. They were dual-earner couples, heterosexual couples, and both partners worked during the day, either durong the week or on the weekend. The data was analyzed by the following four groups: weekday-husband, weekday-wife, and weekend-husband, weekend-wife. The results demonstrated that as the desynchronization of paid work increased, the desynchronization of time spent on housework in the weekday-husband and weekend-husband groups also increased. Second, the amount of leisure time did not affect the desynchronization of time spent on housework. Lastly, the amount of time that one person spent on housework increased the housework time desynchronization level. In addition, if the family had children who attended primary, middle, or high school-mothers in the weekday-wife group completed more housework. These results demonstrated that paid work time desynchronization might be a way to decrease the amount of time that dual-earner wives' spent housework.

Estimation and Application of the Value of Travel Time by Time Period: A Case Study of Downtown Highway Expansion Project (시간대별 통행시간가치 추정 및 적용: 도심부 도로 확장 사업 사례연구를 중심으로)

  • Lee, Jae-Young;Choi, Keechoo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.1D
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    • pp.7-15
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    • 2011
  • The travel time value is important factor for the evaluation of feasibility the transportation facility investment. The existing method for calculation of the travel time for each mode uses daily average trip purpose. So the value of travel time is constant because it is estimated with only daily average proportion. This daily constant time value can distort the results of future demands of toll roads or economic appraisals for the projects. The proportion of the trip purpose varies by time periods. Accordingly the value of travel time also varies by time periods. In this study, times periods are classified as morning peak, evening peak, business time off-peak, and non-business time off-peak. And trip purpose proportions are sorted by each time period from raw data of Seoul household trip study, then the value of travel time for each time period is estimated with these sorted purpose proportions. A case study of Seoul Jung-gu and Yongsan-gu performed with newly estimated time value by time periods. The result of benefit calculation with the daily constant time value is overestimated approximately annual 2.5 billion Won compared by time values by time periods. The demands of toll roads are also overestimated with the existing daily constant time value by daily 3,500 vehicles and total revenue of toll roads are overestimated by annually 1 billion Won. In conclusion, the value of travel time by each time period enables the more precise economic evaluation of the transportation facility investment projects, mode choice behavior, and route choice behavior especially for toll roads.

The Rice and Barley Farm Couples' Time Use Patterns (미맥 농가부부의 생활시간구조)

  • Han, Young-Sun;Lee, Yon-Suk
    • Journal of Family Resource Management and Policy Review
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    • v.11 no.2
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    • pp.111-132
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    • 2007
  • The purposes of this study are to analyze the time use patterns of rice and barley for farm couples. The data used for this study were collected from farm households during the farming seasons (17th to 30th June) and the off-farming seasons (28th November to 11th December) of 2005, using a time diary. The sample for this study consisted of 118 couples, whose principal crops were rice and barley, living in rural area in eight provinces. SPSS Win 12.0 was utilized to analyze the data. The statistical methods used were frequency, percentage and paired t-test. The major findings of this study were as follows. First, the personal care time of wives was shorter than that of husbands, regardless of the fanning period, with the couples showing more personal care time during the off-farming season than during the farming season. Secondly, the total work(paid work plus housework) time of wives was longer than that of husbands during both the farming season and the off-farming season, showing that the labor burden of wives was bigger than that of husbands. Compared to the farming season, the total work time for both husbands and wives was shorter during the off-farming season, due to reduced farm work time, but the housework time increased for both husbands and wives. Thirdly, the leisure time of husbands was longer than that of wives during both seasons. The leisure time increased for both husbands and wives during the off-farming season, but the portion of the increase was bigger for husbands than for wives.

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A Pilot Study on the Muscle Activities in Step Input Test as an Indicator of the Vehicle Characteristics

  • Kong, Yong-Ku;Jung, Myung-Chul;Lee, In-Seok;Hyun, Young-Jin;Kim, Chang-Su;Seo, Min-Tae
    • Journal of the Ergonomics Society of Korea
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    • v.32 no.3
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    • pp.217-227
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    • 2013
  • Objective: The purpose of this study was to analyze 'response time', 'peak response time' and 'overshoot value' for each muscle by applying the EMG signal to the vehicle response in ISO 7401 and to quantify the response of the driver according to vehicle characteristics by comparing vehicle characteristics and muscle responses of the driver. Background: The Open-loop test defined in international standards ISO 7401 is the only method for evaluating the performance of the vehicle. However, this test was focused only on mechanical responses, not driver's ones. Method: One skilled male driver(22 yrs. experience) was participated in this experiment to measure muscle activities of the driver in transient state. Then the seven muscle signals were applied to calculate 'response time', 'peak response time', and 'overshoot value'. Results: In the analyses of the EMG data, the effects of vehicle type and muscle were statistically significant on the 'response time' and 'peak response time'. Also, the effects of vehicle type, muscle, and lateral acceleration level were statistically significant on the 'overshoot value' in this study. According to the analyses of the vehicle motion data, vehicle motion variable(LatAcc, Roll, YawVel) was statistically significant on the 'response time' and vehicle type, vehicle motion variable, and lateral acceleration level were statistically significant on the 'peak response time', respectively. Conclusion: In the analyses of the 'response time' and 'overshoot value', the data of muscle activities(EMGs) was better index that could evaluate the vehicle characteristic and performance than the data of vehicle motion. In case of peak response time, both EMG and vehicle motion data were good index. Application: The EMGs data from a driver might be applicable as index for evaluation of various vehicle performances based on this study.

Effective Real-Time Data Transmission in the Foundation Fieldbus (Foundation Fieldbus에서 효율적인 실시간 데이터 전송)

  • 홍승호
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.11
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    • pp.644-649
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    • 2003
  • This study develops an analytical model for the delay analysis of real-time data in the token-passing service of Foundation Fieldbus(FF). Using the analytical model, this study proposes a network design scheme of FF Two design criteria are introduced in this study; one is the average delay of real-time data, and the other is the maximum allowable delay of real-time data. The network design scheme determines the network parameters that satisfies the performance requirements given by these design criteria.

An Estimation Method of Standard Time Data and a Case Study in Multi-Item Extremely Small Quantity Production (다품종 극소량생산시 표준시간자료의 산정방법 및 적용사례)

  • Shim, Chang-Gun;Byun, Jai-Hyun
    • IE interfaces
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    • v.11 no.2
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    • pp.191-197
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    • 1998
  • Having a reliable standard time data is very important for productivity improvement of any manufacturing company. In this study we present an estimation procedure of standard time data for companies having multi-item extremely small quantity production type and discuss a case study. Included in the discussion are the importance of setup time reduction and the roles of management supervisors, and labor.

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Time and Space through Minimum Units in Animation -Focus on Structural Linguistics- (애니메이션의 시간소와 공간소를 통한 시간성과 공간성 -구조주의 언어학을 중심으로-)

  • Kim, Ji-Hong
    • The Journal of the Korea Contents Association
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    • v.7 no.10
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    • pp.126-134
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    • 2007
  • It have been studied many researches for time and space in film, drama and even animation. This study, however, is for investigating a new methodology of time and space study base on the structural linguistics. It can not be detected any of previous study on this method, and it is the first time to try out for researching with the structural linguistics of time and space in animation with this concept. In order to study on the time and space by applying a new method of structural linguistics, it is identify the terminology and concept of the minimum unite of time and space and than analysis with paradigmatic and syntagmatic. Consequence of this study, it can suggest a new methodology of study in the ways of structural linguistics in animation. Further study is to apply this method on character design in animation.