• 한국건설관리학회논문집
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• 제12권6호
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• pp.42-53
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• 2011

2004년 예정가격 산정방법으로 실적공사비 적산제도가 본격적으로 시행되면서 상대적으로 표준품셈 적산제도의 적용이 하락하였다. 그러나 2010년 하반기 예정가격 산정시 표준품셈 적산제도의 적용비중은 45%이며, 여전히 높은 적용비중을 유지하고 있다. 현행 표준품셈은 예정가격의 산정에 과도한 시간이 소요되고, 시공계획과 자원분배에 적용하기 어려운 단점이 있다. 이와 같은 단점을 개선하기 위하여 본 연구에서는 국내외 품셈의 형식을 고찰하여 이를 국내 도로분야 대표공종에 적용하여 기존 품셈을 일단위 작업조 기반 생산성 정보로 산출하여 유사한 조건하에서 일본 미국의 생산성 정보 및 현장자문을 통한 정보와 비교하였다. 본 연구를 통해 적용된 작업조기반 생산성 정보 산출 방법과 산출 정보의 효용성을 확인하고자한다. 이러한 과정을 통하여 표준품셈을 통한 작업조기반 생산성 정보 산정 방법'과 일단위 작업조 기반 생산성 정보를 제시하고자 한다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.234-235
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• 2019

In the stacking and pitching items of the stone masonry and demolition process presented by 2018's standard of estimate, 7 estimating standards are presented according to the depth of masonry stone, and it is presented that the quantity per unit increases as the depth of masonry stone grows. As a result of analyzing the application status in the site, it is shown that 2 or 3 stones are mainly used according to the stone sizes regardless of the depth of masonry stone, and that as the size of the stone becomes larger, the quantity per unit decreases due to the size per square meter(㎡). Also, in most of sites, machine construction is mainly carried out by excavators with clampers attached to them. Therefore, in the 2019's application standard of estimate, it is analyzed that the size is simplified down to 3 sizes reflecting the site application status and that it is revised as a standard reflecting the result that as the stone size becomes bigger, the productivity increases.

• 한국경영과학회지
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• 제31권1호
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• pp.73-82
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• 2006

Supply chain management (SCM) has been regarded as one of the most critical issues in the current business environment. Moreover, supply chain partnerships between suppliers and buyers in SCM have had a significant impact on supply chain performance. In this paper, we conduct a quantitative analysis for supplier-buyer's profit sharing and pricing policies based on supply chain partnerships. For this purpose, we assume that a two echelon supply chain with a single supplier and a single buyer is given and the buyer faces deterministic demand which is not only a function of buyer's selling price, but also strictly decreasing, concave, and twice differentiable function. Then we will prove the following. Firstly, without supply chain partnerships, there exist supplier and buyer's selling prices per unit such that their total profits are maximized, under the assumption that buyer's order quantity is exactly equal to the demand buyer faced. Secondly, buyer's selling price per unit which maximizes supply chain's total profit with supply chain partnerships is lower than buyer's selling price per unit which maximizes buyer's total profit without supply chain partnerships. Thirdly, given supplier's selling price per unit. buyer's total profit without supply chain part nerships is greater than that with supply chain partnerships, whereas the opposite case happens for supplier's total profit. Finally, there exists supplier's selling price per unit which makes the maximum total profits for both supplier and buyer with supply chain partnerships greater than those obtained for any given supplier's selling price per unit without supply chain partnerships.

• 한국건축시공학회지
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• 제13권5호
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• pp.506-512
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• 2013

Since the amendment of the law on the private sector investment in social infrastructure in January of 2005, the government has been actively promoting Build-Transfer-Lease (BTL) projects. Notably, most new educational facilities have been built as BTL projects. For these facilities, the unit cost per unit area has been applied to predict construction costs. However, since construction costs are mostly managed after the detailed design phase, the costs can be estimated incorrectly. For this reason, cost management is needed in the planning phase, with a sound approximate estimate to prevent the wasteful use of funds. To address this shortcoming, this study aims to develop a quantity prediction model for education facilities using regression analysis in the planning phase. The developed model is focused on the required quantities of reinforced concrete and bricks. In order to achieve the objective, the data of 44 educational facility projects collected from Gyeonggi-do was used in the regression model. This study can be utilized by major stakeholders to accurately predict construction costs by estimating the appropriate quantities of reinforced concrete and bricks in the planning design phase.

• 품질경영학회지
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• 제30권3호
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• pp.53-65
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• 2002

This paper studies an economic manufacturing quantity (EMQ) model with two types of failures and planned preventive maintenance of the production facility. One is a type I (major) failure which should be corrected by a failure maintenance and the other is a type H (minor) failure which can be minimally repaired without interrupting the production run. The objective is to determine the lot size and preventive replacement policy minimizing the long-run expected cost per unit time. We consider a control policy with a constant production lot size and preventive maintenance after completing n production runs. It is assumed that both preventive and failure maintenance times are random and the demand arriving during a stock-out period is lost. An expression for the expected cost per unit time is obtained in the general case. A special case is discussed and numerical results are provided.

• Asian-Australasian Journal of Animal Sciences
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• 제18권12호
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• pp.1735-1740
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• 2005

Forty-two single-bearing and 42 twin-bearing mature Angus${\times}$Hereford cows were allocated, seven per cell to 3 replications of 2 stocking rates (3.2 cows/ha; medium stocking rate [MSR], and 3.8 cows/ha; high stocking rate [HSR]) to graze summer-active and winter-active pastures from late pregnancy to the weaning of their calves. Cow liveweights and growth of calves were recorded as well as estimates of pasture quantity and forage intake. Pasture quantity did not differ in the paddocks grazed by single- and twin-bearing cows during pregnancy, nor effectively did forage intake. Subsequently, intake was higher during mid-lactation especially with twin-rearing cows (25% higher than single-rearing cows at the MSR; 9% at the HSR). However, quantity of pasture decreased for twin-rearing cows and was less than that available to single-rearing cows as lactation progressed. Liveweights of twinrearing cows decreased by 16% from late pregnancy to weaning at the MSR, and by 14% at the HSR, compared to decreases of 1% for single-rearing cows. Twin calves were lighter at birth, had slower growth rates, and were lighter at weaning than single calves. In spite of weaning smaller calves twinning increased the output (kg of calf weaned) per cow and per ha, and increased the efficiency (kg calf weaned per unit of forage eaten by the cow) over single calf production by 46% at the MSR and by 58% at the HSR. Twinning also increased the marginal returns from investment in high input pastures required by the enterprise.

• 한국건설관리학회논문집
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• 제6권5호
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• pp.186-192
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• 2005

본 연구의 목적은 건설현장을 대상으로 환경오염방지시설의 설치 및 환경보전비의 운용 실태를 파악하고, 제도 개선 방안을 제시하는 것이다. 192개 건설현장을 대상으로 조사한 결과, 총 공사비 대비 환경보전비의 계상 비율은 0.59%, 그리고 실제 소요 비용은 총 공사비의 0.94% 수준으로 나타났다. 공사 규모나 현장 입지 조건 등에 따라 유의할 만한 차이점은 없었다. 환경보전비 계상 방식을 보면, 표준품셈 등에 의한 원가 계산 방식 33.6%, 총 공사비 대비 일정 요율 적용 33.7%, 미계상 14%로 나타났다. 건설현장에 설치된 환경오염방지시설을 보면, 소음 진동방지시설보다는 세륜기 방진망 등과 같은 대기 오염방지시설에 대한 투자가 더욱 높았다. 총 공사비와 환경보전비의 상관성은 r2값이 0.23 수준으로 매우 낮게 나타났다. 따라서 환경보전비 계상 방식으로는 일정 요율에 의한 방식보다는 원가 계산 방식이 확대될 필요성이 있다. 이를 위하여는 공사 종별로 설계 적산 단계에서 필수적으로 검토해야 할 환경오염방지설비에 대하여 법적인 기준을 마련하고, 시설별로 적산 기준의 제정 보급이 필요한 것으로 나타났다.

• 대한산업공학회지
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• 제20권3호
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• pp.105-116
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• 1994

This paper presents an inventory model with partial backorders for the situation in which demand is deterministic, lead time follows normal distribution and back order ratio during the stockout period varies in proportion to the length of backorder period In this situations, an objective function is formulated to minimize a time-proportional backorder cast and a fixed penalty cost per unit lost. And then the procedure of iterative solution method for the model is developed to find optimal reorder paint and order quantity and a numerical example to illustrate the proposed method is presented.

• 대한조선학회논문집
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• 제56권6호
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• pp.488-496
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• 2019

The estimation of block erection work time at a dock is one of the important factors when establishing or managing the total shipbuilding schedule. In order to predict the work time, it is a natural approach that the existing block erection data would be used to solve the problem. Generally the work time per unit is the product of coefficient value, quantity, and product value. Previously, the work time per unit is determined statistically by unit load data. However, we estimate the work time per unit through work time coefficient value from series ships using machine learning. In machine learning, the outcome depends mainly on how the training data is organized. Therefore, in this study, we use 'Feature Engineering' to determine which one should be used as features, and to check their influence on the result. In order to get the coefficient value of each block, we try to solve this problem through the Ensemble learning methods which is actively used nowadays. Among the many techniques of Ensemble learning, the final model is constructed by Stacking Ensemble techniques, consisting of the existing Ensemble models (Decision Tree, Random Forest, Gradient Boost, Square Loss Gradient Boost, XG Boost), and the accuracy is maximized by selecting three candidates among all models. Finally, the results of this study are verified by the predicted total work time for one ship among the same series.

• 복합신소재구조학회 논문집
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• 제6권4호
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• pp.24-29
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• 2015

Bridge construction cost estimates have generally been conducted by using historial unit-price(per meter or square meter). The traditional estimating method based on unit-price references can never completely reflect the specialty of cable supported bridge. In this paper, we have developed the system for supporting the approximate construction cost and the quantity estimation based on 3D model information in the pre-project planning phase of 3-span continuous suspension bridge with 2-pylons. First of all, we'd analyzed the design information (such as structural design report, blueprint and quantity) and the real cost data from the existing suspension bridges and derived the design variables of the bridges. We developed the BIM wizard that generates a suspension bridge model parametrically based on derived design variables. The principle material quantities of suspension bridge are calculated directly from 3-dimensional bridge model built by using the BIM wizard. We have established the system that the construction cost can be estimated more specific than the traditional estimating method.