• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2519-2528
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• 2013

The standard of estimate is being used as basic material for appropriating construction expenses of public institutions and private institutions. The present thesis aims to propose a new form of a standard of estimate and a calculation method of work amount of equipment by targeting a representative construction type selected at river reservation work. The present thesis expects that the convenience of users can be expanded by improving applicability of a standard of estimate and simplifying a calculation process of work amount of equipment in a process planning stage so that the provision of work crew lineup information and daily productivity information is possible by a standard of estimate. In case of river conservation work, because the variables called work conditions act very largely, there exists much difficulty for generalizing productivity information and work amount of equipment, but if its accuracy could be enhanced by improving continuous productivity information and work amount information of equipment, the simplification of process planning establishment and cumulative process through a standard of estimate would be possible.

• Journal of the Korea Institute of Building Construction
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• v.14 no.5
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• pp.477-485
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• 2014

Standard production unit system and historical cost data are the most typical data base for calculating budget price in construction. However, these construction cost estimation methods are difficult to calculate proper construction cost because definition, additional allowance or modification criteria is not clear in construction within one day. Therefore, this study identifies problems for standard production unit system and historical cost data and suggests the improvements for them. For the objectives, this study analyzes frequency after implementing survey for 44 specialty contractors in placing at kyeonggi-province. As the results of the study, labor costs in standard production unit system and equipment costs in historical cost data and in construction of pavement and maintenance by project type was exceeded at most high rate against construction cost estimation methods. Based on this result, standard production unit system and historical cost data need to be modified by three improvements such as classification by project scale. These will be baseline data for improvement of construction cost estimation methods for less than one day workload.

• The Korean Journal of Pesticide Science
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• v.11 no.4
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• pp.281-288
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• 2007

This research was carried out to propose the Korean method for estimating the agricultural occupational pesticide exposure level in orchard. The UK-POEM (UK-Predictive Operator Exposure Model) was proposed as a bench-marking model and analysed its performance properties. To extrapolate the Korean agricultural conditions, application equipment, application method, work rate per day, application volume and spraying time of pesticide was surveyed for Korean 204 orchard farmhouse. This survey indicate that the major application equipments are speed sprayer(64.9%) and motor sprayer(33.9%). When they spayed the pesticide with a speed sprayer, they worked for more than 4 hours on area of 4 ha per day. In case of using motor sprayer, they worked for more than 4 hours on area of 1 ha. Based on the above survey result, Korean method for estimating the pesticide exposure level of agricultural worker was proposed finally.

• Journal of Korean Society of Forest Science
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• v.109 no.1
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• pp.72-80
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• 2020

Two strategies for calculating economic feasibility are the machine rate and cash-flow methods. This study used the cash-flow method to evaluate the economic feasibility of the HAM300 yarding operation for extracting tree length logs in Larix kaempferi forest stands. In financial analysis based on 7-year cash-flow, the net present value and pay-back period method were used. We analyzed two scenarios: operating opportunities (50, 100, 150, and 200 days per year) and productivity change yield (7.5 and 10.5 ㎥/scheduled machine hour: SMH). The analysis indicated that high rates of return on extraction activity investment can be achieved when machines are used for >150 days per year. In addition, improved productivity (10.5 ㎥/SMH) increased financial feasibility compared to current productivity (7.5 ㎥/SMH) when machines were operated for 100 days per year. These results suggest that the appropriateness of HAM300 harvesting depends on the number of annual operating days and productivity.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.458-460
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• 2012

1970년대에는 일반적으로 상선에 30-40명의 선원이 탑승했었지만, 최근에는 선박의 자동화와 경제적 문제 때문에 점점 선원수를 줄이고 있는 실정이다. 그러나 최근 통계에 따르면 해양사고의 약 80% 정도가 human error에 의해 발생하고 있으며, 이러한 이유중의 하나는 선원 1명당 부과되는 작업량 과다에 있기도 하다. 즉 선원수의 감소는 업무 또는 작업량의 증가를 가져왔고, 하루에 14-18시간 일하는 것은 특별한 일이 아니게 되었다. 따라서 사고의 증가를 유발하지 않는 범위 내에서 선원수의 감소 범위 산정은 경제적 문제로 인해 크게 대두되고 있다. 현재 안전성과 효율성을 고려한 선원수 산정에 대한 정확한 근거 및 산정자료는 없지만, 최근 IMO, 미해안경비대 (US Coast Guard ; 이하 USCG) 등에서 안전승무정원(safe manning)에 관한 논의 및 연구가 진행되고 있다. 본 논문에서는 선박의 안전승무정원의 평가모델에 대한 최근 국내외 연구현황을 정리하고, 국내 수용을 위한 방안을 제시하고자 한다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.3
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• pp.247-253
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• 1982

This experiment was conducted to find out the optimum date for Combine harvesting of barley in the double cropping paddy field. By the consideration of moisture contents of grain, grain loss, rate of unhulled grain, and discoloring of external plant parts, the optimum date for harvesting was observed to be about 41 days after heading under natural condition. On the other hand, when desiccant was applied on the 34 days after heading, it could be shortened natural harvesting time for 3 days without any yield loss and grain qualities, too.

• Korean Journal of Construction Engineering and Management
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• v.6 no.1 s.23
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• pp.212-219
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• 2005

Time management is important in construction management Especially, in the high-rise apartment housing projects, it is very important to expedite the construction progress in order to meet the planned schedule. The objective of this paper is to propose the baseline for the progress rate using work volume and man $\cdot$ hours performed at work activity level. The work volume far each activity is transformed to the weighted value compared to total work volume for the floor Therefore, a progress rate for an activity is calculated by multiplying a weighted value and work volume. A progress rate for a floor and a building can calculated in this manner, respectively.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.06a
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• pp.235-236
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• 2016

본 논문에서는 로드밸런싱 (load balancing) 기반의 HEVC (High Efficiency Video Coding) 디블록킹 필터(deblocking filter) 병렬화 방법을 제안한다. 본 논문에서는 디블록킹 필터의 병렬화를 위해 TU (Transform Unit)의 경계 정보를 이용하여 픽쳐 단위로 디블록킹 필터의 작업량을 예측하고, 예측된 작업량을 기반으로 코어에 균등한 일을 할당함으로써 디블록킹 필터의 병렬화 효율을 향상 시켰다. 실험결과 제안하는 로드 밸런싱 기반 디블록킹 필터 병렬화 방법을 사용하여 균등 분할 디블록킹 필터 병렬화 방법에 비해 11%의 디블록킹 필터 속도를 향상시켰다.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.380-380
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• 2017

유역에서 발생되는 유출량의 크기를 예측하는 것은 홍수피해를 대비하기 위한 가장 기초적인 활동으로 이루어지며, 이를 위하여 많은 수문모형들이 개발되어 활용되어지고 있다. 이러한 수문모형의 적용을 위해서는 먼저 해당 유역을 재현할 수 있는 매개변수의 보정이 이루어져야 하며 적절한 정도 이상의 검정결과를 확보하여야만 적용이 가능하다. 그러나, 유역 내의 각종 수문특성을 모형의 매개변수로 자세히 나타내는 것은 쉬운 작업이 아니며, 특히 정해진 기간 내에 적용해야 하는 유역이 다수인 경우에는 더욱 힘든 작업이 될 수밖에 없다. 기후변화에 따라 예견되는 강우량 발생 시나리오를 바탕으로 남한 일대의 홍수영향을 지자체별로 평가하기 위한 작업에서는 각 지자체별 많은 소유역에서의 적절한 수문모형 매개변수를 개별적으로 찾아내는 것은 사실상 불가능할 것으로 예견되어, 기후변화 시나리오에서 주어지는 시간별 강우량 자료를 활용하여 첨두유량을 예측할 수 있는 통계적인 방법을 적용하였다. 홍수영향을 평가하기 위하여는 수문곡선 자체보다는 첨두유량의 크기가 더 중요할 것으로 판단되어, 홍수통제소에 제공하는 각 유량관측지점의 유량자료와 시간별 강우량자료로부터 단위 호우사상별 첨두유량과 일정 시간간격 강우량 사이의 다중회귀분석을 통하여 첨두유량 예측 가능성을 확인하였다. 다중회귀분석을 위한 시간간격별 강우량은 각 강우사상에 대하여 첨두유량 발생 직전의 1시간~12시간의 1시간 간격, 1일, 2일, 3일, 5일, 10일 등 17가지의 시간간격 동안의 강우량 자료를 찾아 다중회귀분석에 활용하였으며, 2006년부터 2015년까지 최근 10년 동안의 홍수통제소 자료를 활용하였다. 대상지역은 경기도 남부의 너부대교, 경안교, 복하교, 수직교 수위관측소지점으로 선정하였으며, 일정 크기 이상의 첨두유량 자료를 선별하여 해당 기간에 대한 강우량 자료를 준비하고, 유출량의 크기별로 분류하여 절반의 호우사상은 매개변수 보정에 그리고 나머지 절반의 호우사상은 모형의 검정에 사용하였다. 매개변수 보정결과는 $R^2$ 값이 0.87~0.96을 보이는 등 첨두유량의 예측에 충분히 적용가능한 것으로 판단되었으며, 보정되어진 매개변수로 실시한 검정에서는 0.76~0.85의 $R^2$ 값을 보였다. 본 연구의 결과를 바탕으로, 충분한 유량자료와 시간별 강우량자료만 준비된다면 첨두유량을 예측할 수 있는 회귀방정식으로 이루어진 간단한 모형을 구성할 수 있으며, 이를 활용하여 임의로 주어지는 시간별 강우량 자료를 활용하여 첨두유량의 예측이 가능할 것으로 판단되었다.

• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.121-130
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• 1998

This study was carried out to investigate working time, productivity, and heart rate during thinning using chain saw in Japanese larch(Larix leptolepis) plantation site for analysis of physical work load, and to investigate maximal oxygen uptake of worker for analysis of maximal work capacity. The real working time was 366 minutes in a day ; about 192 minutes in the a.m., 174 minutes in the p.m.. The ratio of real working time per total working time was approximately 90%. The rate of moving(Mo) to real working times was 26.3, which was the largest one of work elements. Average maximal oxygen uptake, as an asset of personnel performance, was $2.42{\ell}/min$($46.5m{\ell}/kg/min$). During the real working time, average productivity, the mean rate of increase of heart rate, and the mean work load index was $2.62m^3/hr$, 93.2%, and 41.9%, respectively.