• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2002년도 춘계학술대회 논문집
• /
• pp.395-398
• /
• 2002

This study is to examine the safety by analizing the hardness of bed and the characteristic of vibration to improve basic efficiency of machine-tool of drill-cell which is a high line center. The mistake of existing design was shown through the analysis of 3-D and structure. The purpose of this paper is to draw up a plan to improve performance and to propose the design method through finding out the optimum by analyzing dynamic property of structure in a quantity-way by CAE for a quantity-analogy of dynamic property in design steps.

• 한국산업융합학회 논문집
• /
• 제19권1호
• /
• pp.31-38
• /
• 2016

Since the oil shock of 1970's there was a strong upward tendency for the use of the high viscosity and poorer quality fuels. Therefore the misfiring engine occurs due to the decrease of quantity injected for lean burn and emission control in Compression Ignition Common Rail Direct Injection diesel engine. In this study, it is designed and used the test bed which is installed with fuel injector controller. In addition to equipped engine using CRDI by controlling the injection timing with mapping modulator, it has tested and analyzed the engine performance and combustion characteristics, as it is varied that they are the operating parameters: fuel injected quantity, engine speed and injection timing.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
• /
• pp.155-160
• /
• 2000

In this paper, we investigated quality properties for the expansive of the CaO-$CaSO_4$ family which used to compensate dry-shrinkage in the floor mortar of On-Dol heating System. This experimental study established the mix condition with quantity of the expansive and is to investigate the relativity between the compress strength and the length change and the relativity between the chemical properties and the length change with the analysis of the physical and chemical properties. As a result of the study, the expansive is controlled by more the CaO than the $CaSO_4$. The relativity between the compress strength and the length change is expressed by exponential function, showing that if the expansive performance is increased, the compress strength is decreased. And the relativity between the chemical properties and the length change is only relative the quantity of the F-CaO among the chemical properties, is expressed by the second order function, showing that if the F-CaO is increased, the expansive performance is increased.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2008년도 추계학술대회A
• /
• pp.1010-1015
• /
• 2008

The rapid wear rate of cutting tools due to high cutting temperature is a critical problem to be solved in machining of hardened steel. Application of cutting fluid influences the performance of machining because of its lubrication and cooling actions. But, the environmental concerns call for the reduced use of cutting fluids in machining operations. Near-dry machining such as minimum quantity lubrication is regarded as one of the solutions to this difficulty. In the present work, cutting fluid was applied as a high velocity jet at the machining zone continuously at an extreme low rate using a fluid application system developed namely Electro Static Lubrication (ESL) during drilling of hardened steel. The performance of ESL has been compared with that of dry and MQL (minimum quantity lubrication) machining.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제18권2호
• /
• pp.122-129
• /
• 2018

Purpose: This article develops an optimal reliability acceptance sampling plan for the case where the degradation quantity of the performance characteristic follows Weibull distribution. Method: For developing reliability acceptance sampling plans, the sample size and the acceptance constant are determined based on the accelerated characteristic of the test condition and the product. Results: The sample size and the acceptance constant are provided such that the constraints of the producer and the consumer risks are satisfied. Conclusion: Reliability acceptance sampling plans based on the accelerated degradation test method can be used for the quality control within a resonable amount of cost and time. In this article. an optimal reliability sampling plans are newly developed for this purpose.

• 한국산림과학회지
• /
• 제76권4호
• /
• pp.348-356
• /
• 1987

산악지(山岳地) 임도설계(林道設計)의 시간(時間)과 인력(人力)을 절약하는 방법의 일환으로 토량(土量)을 간편하게 산출(産出)하는 방법(方法)을 강구하였다. 이 방법(方法)을 적용하는 이론적(理論的) 배경(背景)으로 0선측량법(線測量法)의 도입(導入)과 2/3 절토노폭개념(切土路幅槪念) 및 절토량(切土量) = 성토량(盛土量) 개념도입(槪念導入)의 타당성을 제시하고 이와같은 원리(原理)들을 산악지림도시공(山岳地林道施工)에 적용한다는 전제하에 삼각함수법을 적용하여 토량환산표(土量換算表)를 표(表) 3과 4와 같이 제작하였다. 표(表) 3은 노폭(路幅)을 0.5m 괄약으로 구분(區分)하여 시공지 경사도별로 절토량(切土量)을 추정(推定)한 것이고, 표(表) 4는 현지(現地)에서 절토폭(切土幅)을 측정하여 절토량(切土量)을 산출(算出)하는데 적용하는 환산계수표(換算係數表)이다. 동표(同表) 등을 적용하면 토량계산(土量計算)을 위한 현지측량(現地測量)과 내업시간(內業時間)은 단축시킬 수 있을 것이다.

• 산업경영시스템학회지
• /
• 제36권4호
• /
• pp.31-37
• /
• 2013

In this paper, we develop an efficient approach to solve a continuous review inventory system with a budget constraint when the semi-finished product and optional components are required to be assembled. We are, in particular, interested in a budget constraint that includes a service level. The service cost, such as labor and facility costs, tends to increase as the service level increase, and it makes the problem difficult to solve. Assuming that the reorder point for a semi-finished product is given, we show that the order quantity for the semi-finished product and the order quantity and reorder point for optional components can be determined by minimizing the total cost that includes setup cost, inventory holding cost, and shortage cost. The performance of the proposed approach is tested by numerical examples. By using sensitivity analysis, we conclude that, as the reorder point for semi-finished product increases, the order quantity for semi-finished product increases, whereas the order quantity and reorder point of optional components decreases.

• 한국지진공학회논문집
• /
• 제18권1호
• /
• pp.9-18
• /
• 2014

The purpose of this study is to investigate the seismic behavior of hollow reinforced concrete bridge column systems with reinforcement details for material quantity reduction and to provide the details and reference data. Five hollow reinforced concrete bridge columns were tested under a constant axial load and a cyclically reversed horizontal load. The accuracy and objectivity of the assessment process can be enhanced by using a sophisticated nonlinear finite element analysis program. The adopted numerical method gives a realistic prediction of seismic performance throughout the loading cycles for several the investigated test specimens. This study documents the testing of hollow reinforced concrete bridge column systems with reinforcement details for material quantity reduction and presents conclusions based on the experimental and analytical findings.

• 전기학회논문지
• /
• 제63권10호
• /
• pp.1423-1427
• /
• 2014

Quantity of the solar power generation is heavily influenced by weather. In other words, due to difference in insolation, different quantity may be generated. However, it does not mean all areas with identical insolation produces same quantity because of various environmental aspects. Additionally, geographic factors such as altitude, height of plant may have an impact on the quantity. Hence, through this research, we designed a system to predict efficiency of the solar power generation system by applying insolation, weather factor such as duration of sunshine, cloudiness parameter and location. By applying insolation, weather data that are collected from various places, we established a system that fits with our nation. Apart from, we produced a geographic model equation through utilizing generated data installed nationwide. To design a prediction model that integrates two factors, we apply fuzzy algorithm, and validate the performance of system by establishing simulation system.

• 한국건설관리학회논문집
• /
• 제21권5호
• /
• pp.20-28
• /
• 2020

견적업무는 공사비를 산출하는 것을 목적으로 수행되며, 단가정보와 물량정보의 곱으로 산출되므로 성공적인 건설 프로젝트의 수행을 위해 정확한 물량산출이 선행되어야 한다. 또한 현재 견적 전문가를 대상으로 한 설문조사에 의하면, 물량산출 성과물에 대한 만족도가 높음에도 불구하고 이에 대한 검증작업이 필요하다는 의견이 다수이다. 그러나 현재는 견적 작업자의 경험도에 의존하는 등 객관적인 검증방안이 미비한 실정이다. 따라서 본 연구는 작업자 개개인의 업무능력에 의존하지 않고 검증할 수 있는 검증방안을 제안하였다. 제안하는 검증방안은 산출서 물량과 비교하여 ±5%의 오차를 가지는 검증물량을 산출하여 산출한 물량에 대한 가이드 라인을 제시하였다. 이를 위해 기존에 수행된 프로젝트 데이터를 활용하여 도면 및 산출서를 분석하고, 도면으로부터 정보를 추출하여 검증물량을 산출할 수 있는 산식을 개발하여 검증물량산출 산식이라고 정의하였다. 본 연구의 결과인 검증물량산출 산식은 최단기간 내에 최소인원으로 물량산출 성과물에 대한 검증업무를 수행할 수 있게 하는 것을 목적으로 한다. 이로 인해 작업자가 산출한 물량에 대한 신뢰도를 확보할 수 있을 것으로 생각되며, 오류가 발생한 항목에 대한 검토가 수행됨에 따라 효율적인 견적업무가 가능하게 될 것으로 기대된다.