• 한국도로학회논문집
• /
• 제19권5호
• /
• pp.153-162
• /
• 2017

PURPOSES : This study was conducted to analyze the effects arising from extending the duration of nighttime road construction on improving road quality and durability. METHODS : Most previous studies estimating the social cost of various construction conditions did not consider road pavement cooling time as a factor in improving road pavement quality. This study investigated the feasibility of achieving higher road quality and durability by extending the duration of nighttime road construction time extension. For this investigation, the effects of such an extension on traffic conditions were analyzed based on micro-simulation studies and scenario-based cost-benefit analyses, using factors including traffic volume, delay, construction cost, and road pavement cooling time. RESULTS : The results of the traffic simulation studies and cost-benefit analyses indicate that the current road construction method that emphasizes completing nighttime road construction by 6 a.m. reduces pavement life while causing relatively little traffic delay. If the night construction time is instead extended to 2 p.m., road pavement lifetime is increased, reducing road re-construction cost. These savings are greater than the cost of congestion arising from extending the duration of nighttime construction. CONCLUSIONS : The current nighttime construction durations need to be extended in order to efficiently manage roads and reduce road management costs.

• 한국초지조사료학회지
• /
• 제20권3호
• /
• pp.161-168
• /
• 2000

The experiment was carried out to investigate the effect of extension of grazing duration in late autumn on grass growth in following spring, in order to improve the rate of self-sufficiency for roughage feed. Plant height, total biomass and litter production of herbage were increased when the grazing was finished early in late autumn. The proportions of clover and litter, and amounts of animal intake were decreased, with extended grazing duration in late autumn. But when the grazing was finished late in autumn, the contents of crude protein (CP, %) of herbage were increased, contents of acid detergent fiber (ADF, %), neutral detergent fiber (NDF, %) and crude ash (%) were decreased in pasture after grazing, therefore the contents of total digestible nutrients (TDN, %) and relative feed value (RFV) of herbage were improved. The early end grazing showed that plant height, total biomass and litter production of herbage in following spring were higher than those in late end grazing. However, increased yields were not significantly different among end grazing treatments (0.12-0.15 tonha), except for the final end grazing in late autumn (0.01 tonha). With extended grazing duration in late autumn, the contents of CP of herbage in following spring were increased, contents of ADF, were decreased, and RFV were improved. (Key words : Extension of grazing duration, Plant height, Biomass, Amount of intake, Increased yield, Crude protein, TDN) rll\ulcorner c# qiil x i 9 ~ 1 a% * (College of Natural Resources, Taegu Univ., Kyongsan, 71 2-714, Korea) * $4 4 qiil 34 qq(Co1lege of Liberal Arts & Sciences, Yonsei Univ., Wonju, 220-701, Korea) '* 8 * jL@%ft@ &@%(Faculty of Agriculture, Hokkaido Univ., Sapporo, 060 Japan)

• 무역상무연구
• /
• 제15권
• /
• pp.137-165
• /
• 2001

The study on the duration of risk in the marine insurance has been paid a great attention because the marine insurance has to provide several indemnity conditions including the one to be compensated the loss when the accident happens. The research examines as to how the duration of risk has been extended from the beginning period to now. The results show the duration of risk has been continually extended in terms of place and time by a dramatic change of environment related to the marine insurance including marine transportation, a variety of goods, development of marine communication, many different trading conditions, etc, and requirement of the assured. The validity of the duration of risk is effected when the ship leaves at the port and is terminated when the ship arrives at the final destination. It in the Lloyd's age has been started when the products was charged to the ship and terminated when the one was safely discharged to the destination. Recently, the duration of risk in England Marine Insurance attaches from the time the goods leave the warehouse or place of storage at the placed named for the commencement of the transit, continues during the ordinary course of transit and terminates on delivery to the consignees or other final warehouse or place of storage at the destination named. Further research on the extension of the duration of risk must be conducted according to the being large scale of the ship and goods.

• 한국건설관리학회논문집
• /
• 제6권3호
• /
• pp.81-89
• /
• 2005

공공건설사업은 수많은 공종의 집합으로 이루어져 있어 공사중단, 공사지체 등으로 인한 공기지연이 필연적으로 발생하고 있다. 공기지연이 발생하는 경우에 지연일수를 산출하는 방법은 많은 연구를 통해 제시되고 있으나, 공기지연에 따른 계약금액조정에 대해서는 구체적으로 언급하고 있지 않기 때문에 실제 공공건설사업에 적용하는 데는 어려움이 있다. FIDIC계약조건에 비해 회계예규인 공사계약일반조건에 불분명한 문제를 안는 있는 것으로 나타났다. 따라서 본 연구는 공공건설프로젝트에 국한하여 공사 수행중에 공기관련 설계변경사유가 발생될 경우 공기연장 절차를 보다 투명하게 하고, 계약금액산정의 기준이 되는 구간에 대한 기준을 명확히 하기 위한 방안으로 명확한 공기연장사유, 수정공정표제출 등에 대한 방안을 제시하였다.

• 한국건설관리학회논문집
• /
• 제6권6호
• /
• pp.142-151
• /
• 2005

공공 건설공사에 있어서 발주관청에서 산정한 예정공사기간과 실제 공사기간 사이에 차이가 발생하여 당초 계획했던 프로젝트가 예정준공일보다 지연되는 경우가 빈번하게 발생한다. 이는 공사지연에 따른 시공 중 문제점뿐만 아니라 시설물사용 계획의 차질로 초래되는 물류비용증가, 시민불편가중, 시설물을 이용한 생산 및 공급차질과 이로 인한 각 분야의 막대한 손실 등으로 이어진다. 이러한 손실들을 줄이기 위해서는 발주시 산정하는 예정공사기간의 정확도를 높여야 한다. 본 연구는 발주관청의 예정공사기간 산정시 지표로 활용할 수 있는 공사기간보정요소를 포함하는 예정공사기간 산정모델을 제시하여 적정공사기간을 확보함으로서 시공 중의 공기 연장 빈도를 줄이고 나아가서는 공공 프로젝트의 성공적인 운영에 기여하고자 한다.

• 한국건설관리학회논문집
• /
• 제20권4호
• /
• pp.104-113
• /
• 2019

공기연장과 관련한 분쟁은 해당 이슈들이 공기에 얼마나 영향을 미치는지에 대해 공기를 분석하고 법원과 같이 제3자의 판단을 돕기 위한 근거로 제출하는 특징이 있다. 하지만 대다수의 국내현장은 분석에 필요한 기초자료가 부재하거나, 분쟁 발생 이후 자료를 수집하는 등 대응을 위한 합리적인 업무 및 입증 방안의 프로세스가 정립되지 않아 공기연장에 따른 손실을 증명하는데 어려움이 있다. 따라서 본 연구는 공기연장 분쟁 시 입증의 수단인 공기분석에 필요한 정보를 수집, 정리하고 업무 프로세스를 제시함으로써 합리적인 처리지원 및 관리 효율성을 향상하고자 하였다. 제안된 프로세스를 사용하여 실제 공기연장 분쟁에 적용 검증한 결과, 프로세스 적용현장이 미적용 현장에 비해 실무자는 약 33%, 계약담당자는 약 46%, 법률자문가는 약 48% 더 높은 만족도를 나타냈으며 91%의 동일한 매트릭스 비교 결과가 나타났다. 본 연구를 통해 공기연장 분쟁에서 근거로 사용되는 공사기간 분석 업무의 효율화를 도모할 수 있을 것으로 판단되며, 향후 프로세스를 활용한 시스템 설계연구가 지속되어야 할 것으로 보인다.

• 한국운동역학회지
• /
• 제31권2호
• /
• pp.140-147
• /
• 2021

Objective: The purpose of this study is to identify the mechanism of changes in maximum voluntary torque with the magnitude and duration of pre-activation torque during voluntary isometric knee extension. Method: 11 male subjects (age: 25.91±2.43 yrs., height: 173.12±3.51 cm, weight: 76.45±7.74 kg) participated in this study. The subjects were required to produce maximal voluntary isometric torque with a particular pre-activation torque condition. The properties of pre-activation torque consisted of the combinations of 1) three levels of magnitude, e.g., 32 Nm, 64 Nm, 96 Nm, and 2) two levels of duration, e.g., 1 sec, and 3 sec; thus, a total of six conditions were given to the subjects. The force and EMG data were measured using the force transducers and wireless EMG sensor, respectively. Results: The results showed that the maximum voluntary torque increased the most with relatively large and fast (96 Nm, 1 sec) pre-activation condition. Similarly, with relatively large and fast (96 Nm, 1 sec) preactivation, it was found that the integrated EMG (iEMG) of the agonist muscles increased, while no significant changes in the co-contraction of the antagonist muscles for the knee extension. Also, the effect of pre-activation conditions on the rate of torque development was not statistically significant. Conclusion: The current findings suggest that relatively larger in magnitude and shorter in duration as the properties of pre-activation lead to a larger magnitude of maximal voluntary torque, possibly due to the increased activity of the agonist muscles during knee extension.

• 한국물환경학회지
• /
• 제35권6호
• /
• pp.481-496
• /
• 2019

The Ministry of Environment has measured streamflow at eight-day intervals for the estimation of standard flow of the Total Maximum Daily Loads (TMDL) system. This study identified the availability of the partially measured the eight-day interval data for estimating standard flow and found the optimal extension techniques of standard flow. The study area was selected for the Nakbon-A watershed in the Nakdong River, and four streamflow record extension techniques of standard flow were considered: extension, percentile, drainagearea, and regional regression methods. The flow duration curve (FDC) using the eight-day interval streamflow data indicated very high Nash and Sutcliffe Efficiency (NSE) values above 90 % from FDC-II to FDC-VII compared to FDC-VIII, the standard FDC. This result demonstrates that FDC using daily data of three-six cumulative years could represent standard FDC fairly well. For the streamflow record extension techniques of standard flow, the percentile method was selected as the optimal alternative, showing the minimal difference from FDC-VIII. These results validate the availability of the eight-day interval streamflow data in the standard flow estimation and the application of extension techniques. It seems that these results could reduce the uncertainty of partially measured streamflow data for water quantity and quality management.

• 대한한의학회지
• /
• 제16권2호
• /
• pp.299-311
• /
• 1995

The studies were investigated in the coma time and the survival time induced by KCN, the duration of breathing after decapitation, the survival time following ligation of both common carotid arteries and the survival time after it is treated for normobaric bypoxia with a nitrogen gas, a carbon dioxide gas or a vaccum in mice. The results were as follows: 1. In histotoxic anoxia, Moschus(0.4mg／kg, p.o) demonstrated a protective effect on coma induced by a sublethal dose of KCN(1.8mg／kg, i.v.) in mice. 2. Mice subjected to a lethal dose of KCN(3.0mg／kg, i.v.) did not die by administration of Moschus. 3. Moschus was significantly extended the duration of breathing after decapitation in mice. 4. Moschus showed a significant extension of survival time in mice following ligation of both common carotid arteries. 5. In the normobaric hypoxia with a nitrogen gas, Moschus showed a significant extension of survival time in mice. 6. In the normobaric hypoxia with a carbon dioxide gas, Moschus showed a significant shortness of survival time in mice. 7. In the normobaric hypoxia with a vaccum, Moschus showed a significant extension of survival time in mice. From the above results, it is suggested that Moschus demonstrated protective effects on the brain damages induced by cerebral anoxia.

• 한국추진공학회지
• /
• 제21권3호
• /
• pp.68-75
• /
• 2017

듀얼 벨 노즐은 고도 보정 노즐의 일종으로 일반적인 벨 노즐의 탈설계점에서의 비추력 손실을 최소화할 수 있는 노즐이다. 본 논문에서는 팽창비가 고정된 듀얼 벨 노즐의 천이특성을 파악하기 위하여 전산수치해석을 수행하였다. 주요 설계변수로는 확장부 길이와 변곡각 크기를 선정하였다. 확장부 길이가 증가할수록 천이고도 및 천이지속시간은 증가하였고, 추력계수 감소폭은 감소하였다. 변곡각 크기가 증가할수록 천이고도 및 천이지속시간은 감소하였고, 추력계수 감소폭은 증가하였다.