• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.286-291
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• 2001

This paper describes an optimal scheduling for ice slurry systems for energy cost saving. The optimization technique applied in the study is the dynamic programming method, for which the state variable is the storage in the ice storage tank and the control variable is the state of chiller's on-off switching. Though the costs during charge period is included in optimization by taking the average cost of ice per hour for slurry making, the time horizon for the simulation is limited building cooling period because accurate charge rate from the ice maker into the ice storage tank cannot be estimated during the charge period. In the operating simulation after optimizing procedure, energy consumption and operating cost for the optimal control are calculated and compared with them for a conventional control with one case of cooling load profile.

• 전자공학회논문지A
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• 제32A권10호
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• pp.81-92
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• 1995

In this paper, we present a high-level synthesis system that generates area-efficient RT-level datapaths with multiport memories. The proposed scheduling algorithm assigns an operation to a specific control step such that maximal sharing of functional units can be achieved with minimal number of memory ports, while satisfying given constraints. We propose a measure of multiport memory cost, MAV (Multiple Access Variable) which is defined as a variable accessed at several control steps , and overall memory cost is reduced by equally distributing the MAVs throughout all the control steps. Experimental results show the effectiveness of the proposed algorithm. When compared with previous approaches for several benchmarks available from literature, the proposed algorithm generates the datapaths with less memory modules and interconnection structures by reflecting the memory cost in the scheduling process.

• 한국정밀공학회지
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• 제19권12호
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• pp.142-149
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• 2002

In this paper, the metal forming process is caused of rise of the unit cost of production in increase of the lead-time and cost because of manufacturing final product through a few the number of processes. Flow control complex forming is proposed to put into formulation in order to apply cold forging from conventional approximate similarity theory, and the forming loads of the real material(AISI 1008) can be calculated by put at the new similarity formula the load by plasticine model material experiment through hub clutch. In order to reduce lead-time and cost the technology is used to manufacture with lower die of this product. By the application synthetic resin as the raw material, it is have the merit such short lead-time, low cost, good surface finish etc., as compared with the machine work.

• 전기학회논문지P
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• 제63권2호
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• pp.69-73
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• 2014

In this paper, remote control and surveillance monitoring system of HID street-lamp using low-cost type of Zigbee communication module was developed. A plurality of capacitors with different capacity are attached to magnetic ballast for HID lamps. Changes in the amount of illumination can be adjusted by the changes in capacity so that the electric energy can be reduced. In Zigbee communication module, a ATmega128L microprocessor is used and in main CPU, ARM9 Core is used to construct a low-cost smart system. In surveillance monitoring systems, the system was configured to remote monitoring of presence of error in the lamp abnormalities, the status of leakage current and abnormalities of ballasts and capacitors and the validity of the proposed empirical experiment was confirmed.

• Asian Pacific Journal of Cancer Prevention
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• 제16권3호
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• pp.1295-1301
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• 2015

Background: Cancer imposes a significant economic burden on individuals, families and society. The purpose of this study was to estimate the economic burden of cancer using the healthcare claims and cancer registry data in Korea in 2009. Materials and Methods: The economic burden of cancer was estimated using the prevalence data where patients were identified in the Korean Central Cancer Registry. We estimated the medical, non-medical, morbidity and mortality cost due to lost productivity. Medical costs were calculated using the healthcare claims data obtained from the Korean National Health Insurance (KNHI) Corporation. Non-medical costs included the cost of transportation to visit health providers, costs associated with caregiving for cancer patients, and costs for complementary and alternative medicine (CAM). Data acquired from the Korean National Statistics Office and Ministry of Labor were used to calculate the life expectancy at the time of death, age- and gender-specific wages on average, adjusted for unemployment and labor force participation rate. Sensitivity analysis was performed to derive the current value of foregone future earnings due to premature death, discounted at 3% and 5%. Results: In 2009, estimated total economic cost of cancer amounted to $17.3 billion at a 3% discount rate. Medical care accounted for 28.3% of total costs, followed by non-medical (17.2%), morbidity (24.2%) and mortality (30.3%) costs. Conclusions: Given that the direct medical cost sharply increased over the last decade, we must strive to construct a sustainable health care system that provides better care while lowering the cost. In addition, a comprehensive cancer survivorship policy aimed at lower caregiving cost and higher rate of return to work has become more important than previously considered.

• 한국BIM학회 논문집
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• 제11권2호
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• pp.1-16
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• 2021

Since entering the 21st century, the construction industry has developed faster and faster, and more and more technologies have been applied in the construction industry. BIM technology (Building Information Modeling) was born in this environment. The application of BIM technology can greatly improve the efficiency of cost management and help achieve the goal of cost management. But through BIM to realize project cost management, there is still no good solution. In order to solve this problem, this paper puts forward the concept of WBS structure applied to construction projects by studying the BoQ (Bill of Quantities) list based on BIM, and proposes the numbering method of the structure. The WBS (Work Breakdown Structure) structure proposed in this paper divides more than 5000 cost objects into 133 projects according to the type of work and project schedule. This structure helps to realize the application of BIM in project cost management. Although this article has studied more than 5000 data of three projects, it does not think that it can cover all cost objects in the existing construction industry. The purpose of this article is to propose a solution for cost and Process Control using BIM-based BoQ data.

• 한국건설관리학회논문집
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• 제4권4호
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• pp.212-219
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• 2003

건설공사에서 공사비 계획 및 관리를 위한 코스트 모델은 공사입찰$\cdot$계약단계에서 도급공사비 결정에 중요한 기능을 담당할 뿐만 아니라 건설사업 수행 전 단계에 걸쳐 건설공사에 소요될 비용을 추적, 관리하여 주어진 예산범위 내에서 최적의 목적물을 설계 시공하여 궁극적으로 발주자의 투자비용에 대한 가치를 극대화하고 비용관리업무의 적정성을 도모하는 기능을 담당하고 있다. 그동안 내역입찰방식을 널리 채택하고 있는 건설공사에서 내역서는 공사비 예측 및 계획 등 공사관리에 있어서 중요한 수단으로 활용하여 왔으나, 현행 내역모델은 공사비의 예측 및 비용관리 측면에서 지나치게 상세하며, 공사계획 및 관리 업무와 연계시키는데도 한계가 있는 것으로 지적되고 있다. 건설공사를 구성하는 세부 단위작업에 소요되는 비용은 모두 중요한 관리대상이지만, 단위작업의 내용에 따라 비용이 차지하는 비중과 코스트 결정에 미치는 영향력에는 차이가 있다. 이러한 비용결정의 구조적 메커니즘에 착안하여 본 연구에서는 건설공사 비용결정에 중요한 영향을 미치는 작업내용을 규명하여 정확성을 유지하면서 단순 간결한 코스트 예측모델을 제안 및 검증하는 것을 목적으로 하고 있다.

• 한국항행학회논문지
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• 제8권1호
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• pp.19-26
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• 2004

본 논문은 군에서 운용중인 대공포 사격 훈련용으로 개발한 무인 표적기용 자동비행시스템 개발에 관한 논문이다. 조종사에 의해 수동으로 운용중인 표적기를 자동화함으로써 조종사 측면에서는 비행업무를 경감시키고, 군 측면에서는 사격훈련 예산절감이라는 장점을 가지게 된다. 현재까지 개발된 대부분의 UAV(Unmanned Aerial Vehicle)는 항공기 자세를 측정하기 위해 AHRS(Attitude & Heading Reference System)와 IMU(Inertial Measurement Unit)등의 고가의 센서를 장착하고 있지만 이를 장착하고 무인기를 사격훈련용으로 사용하기에는 예산절감이라는 목적에 적합하지 않다. 이에 본 논문은 저가의 센서를 장착하고 자동비행이 가능하도록 저가형 자동비행시스템을 개발하였으며, 자동비행 컴퓨터를 포함한 센서, 전원모듈, 스위칭 모듈, 모니터링 모듈, RC 수신기를 하나의 모듈로 단일화하여 통합형 자동비행시스템을 개발하였다. 또한 비행시험을 통하여 자동비행시스템 성능을 입증하였다.

• 한국항행학회논문지
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• 제8권2호
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• pp.105-111
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• 2004

최근의 무인항공기는 정찰임무를 비롯하여 무인기에 미사일을 장착하여 지대공 공격 임무를 수행하기까지 군용으로 뿐만 아니라 기상 관측, 해상 관측 등의 목적으로 폭넓게 활용하고 있으며, 점차 필요성이 높아지고 있다. 이러한 무인기는 정밀한 자세제어를 위하여 자세정보를 제공하는 AHRS와 같은 센서를 장착하는데 비용이 500만원 정도에서 고급 센서는 수 천 만원에 이르고 있다. 최근 한국항공우주연구원에서는 이러한 고가의 센서 출력정보인 자세각 정보를 사용하지 않고 각속도 정보를 기반으로 저가형 자동비행시스템을 개발하여 소형표적기와 무인표적기 비행시험을 통하여 성능을 입증하였다. 본 논문에서는 무인항공기의 항법시스템 설계를 위하여 목표로 하는 신뢰성을 충족시키면 동시에 저가형인 GPS 센서를 선택하기 위하여 Hardware in the Loop Simulation(HILS)을 통하여 GPS 출력주파수에 따른 성능을 확인하였다. 마지막으로 무인표적기에 자동비행시스템과 항법시스템을 장착하여 비행시험을 수행하였으며, 설계된 항법시스템 성능을 비행시험 결과를 통하여 확인하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집(한일합동학술편); 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.812-816
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• 1987

A quadratic regulator problem for a class of nonlinear system, in which a small parameter multiplies the control cost, is considered. In the analysis of the problem, we utilize the method of multiple time-scale decomposition which has been devised for analyzing complex linear cheap control problems. In so doing, we extend the class of nonlinear systems, considerably, for which the minimum cost becomes zero as the small parameter goes to zero.