• 동력기계공학회지
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• 제21권6호
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• pp.62-67
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• 2017

In order to achieve high efficiency of energy use and environment-friendly architectural design, various loads such as cooling, heating and hot water required by the building sector must be accurately predicted. Many studies used dynamic simulation tool to evaluate and analyze building energy performance. However, there are few studies on the comparative analysis of load results by each simulation and the evaluation of simulation characteristics and functions. In this study, the cooling, heating loads and energy demand of the buildings were evaluated using three dynamic simulations for the building with the same input conditions, and the characteristics of each simulation were compared and analyzed through the results. As a result of simulation comparative analysis, cooling, heating load and energy demand was lowest in square type and north-south direction conditions.

• 한국ITS학회 논문지
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• 제19권6호
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• pp.118-133
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• 2020

최근 통합교통서비스(Mobility-as-a-Service)의 개념을 도입하여 이용자들의 이동성과 접근성을 향상시키고자 하는 연구가 진행되고 있다. 특히 카셰어링, 택시 등 에 대해 수요와 공급에 따라 지역을 구분하여 가격을 책정하는 유동적인 가격 책정 전략을 도입하여 단일 요금제가 가지는 서비스 기피 등의 문제를 해결함과 동시에 기업과 운전자들의 수익성에 긍정적인 영향을 줄 수 있을 것으로 기대되고 있다. 본 연구에서는 승객과 운전자간의 배차거리, 승객의 운행거리, 승객의 목적지에 대한 HDBSCAN 알고리즘을 통해서 정밀하게 인식된 수요 밀집지역, 승객과 운전자가 생각하는 선호가격을 고려하여 승객과 운전자의 입장에서 Matching Matrix를 생성한다. 이를 조합하고 보상에 반영하여, 강화학습이 더욱더 현실적인 유동적인 가격 책정전략을 도출할 수 있는 새로운 방법론을 제안한다.

• Industrial Engineering and Management Systems
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• 제6권2호
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• pp.106-118
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• 2007

This paper present a new optimization model to generate aggregate production planning by considering electric cost. The new Time Of Switching (TOS) electric type is introduced by switching over Time Of Day (TOD) and Time Of Use (TOU) electric types to minimize the electric cost. The fuzzy demand and Dynamic inventory tracking with multiple plant capacity are modeled to cover the uncertain demand of customer. The constraint for minimum hour limitation of plant running per one start up event is introduced to minimize plants idle time. Furthermore; the Optimal Weight Moving Average Factor for customer demand forecasting is introduced by monthly factors to reduce forecasting error. Application is illustrated for multiple cement mill plants. The mathematical model was formulated in spreadsheet format. Then the spreadsheet-solver technique was used as a tool to solve the model. A simulation running on part of the system in a test for six months shows the optimal solution could save 60% of the actual cost.

• 산업경영시스템학회지
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• 제35권4호
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• pp.110-117
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• 2012

The demand for facility used in producing multi-products is changed dynamically for discrete and finite time periods. The excess or the shortage for facility is occurred according to difference of the facility capacity size and demand for facility through given time periods. The shortage facility is met through the outsourcing production. The excess facility cost is considered for the periods that the facility capacity is greater than the demand for the facility, and the outsourcing production cost is considered for the periods that the demand for facility is greater than the facility capacity. This paper addresses to determine the facility capacity size, outsourcing production products and amount that minimizes the sum of the facility capacity cost, the excess facility cost and the outsourcing production cost. The characteristics of the optimal solution are analyzed, and an algorithm applying them is developed. A numerical example is shown to explain the problem.

• 한국시스템다이내믹스연구
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• 제9권1호
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• pp.125-141
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• 2008

It is very difficult to predict future demand/supply, price for resources with acceptable accuracy using regression analysis. We try to use system dynamics to forecast the demand/supply and price for nickel. Nickel is very expensive mineral resource used for stainless production or other industrial production like battery, alloy making. Recent nickel price trend showed non-linear pattern and we anticipated the system dynamic method will catch this non-linear pattern better than the regression analysis. Our model has been calibrated for the past 6 year quarterly data (2002-2007) and tested for next 5 year quarterly data(2008-2012). The results were acceptable and showed higher accuracy than the results obtained from the regression analysis. And we ran the simulations for scenarios made by possible future changes in demand or supply related variables. This simulations implied some meaningful price change patterns.

• Steel and Composite Structures
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• 제37권2호
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• pp.151-173
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• 2020

This paper aims to probabilistically evaluate performance of two types of I beam to box column (IBBC) connection. With the objective of considering the variability of seismic loading demand, statistical features of the inter-story drift ratio corresponding to the second, fifth and eleventh story of a 12-story steel special moment resisting frames are extracted through incremental dynamic analysis at global collapse state. Variability of geometrical variables and material strength are also taken into account. All of these random variables are exported as inputs to a probabilistic finite element model which simulates the connection. At the end, cumulative distribution functions of local seismic demand for each component of each connection are provided using histogram sampling. Through a parametric study on probabilistic local seismic demand, the influence of some geometrical random variables on the performance of IBBC connections is demonstrated. Furthermore, the probabilistic study revealed that IBBC connection with widened flange has a better performance than the un-widened flange. Also, a design procedure is proposed for WF connections to achieve a same connection performance in different stories.

• Structural Engineering and Mechanics
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• 제17권3_4호
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• pp.281-290
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• 2004

A review of current procedures being used in engineering practice to analyze the response of structure/foundation systems subjected separately to different types of dynamic excitation, such as earthquake, sea-wave action, wind, or moving wheel loads, is presented. Separate formulations are given for analyzing systems in the time and frequency domains. Both deterministic and stochastic forms of excitation are treated. A distinction is made between demand and capacity analyses.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.113-118
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• 1998

In modern mechatronics new concepts of machines and processes are found by using the collected knowledge of all disciplines and by offering functional solutions. Most of the problems in the field of mechatronics demand technical innovations on the field of actuators, sensors and control methods. It demands also high dynamic drives with power electronics, able to cope with the new requirements. The paper presents some trends and industrial experiences with power components for high dynamic drives.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2010년도 한국컴퓨터종합학술대회논문집 Vol.37 No.1(D)
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• pp.380-383
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• 2010

본 논문은 원격에서의 의료 기술이나, 대용량을 요구하는 실시간 협업 등에서 사용자의 요구에 따라 빠르게 요구 대역폭을 할당하고 보장하기 위한 Dynamic Circuit Network 구현 방법을 기술 하였다. 이를 위해 QoS, MPLS, RSVP 기술을 기반으로 2계층의 LSP을 동적으로 할당할 수 있도록 하였으며, 사용자는 이를 웹 기반의 인터페이스(web-based user interface)를 통해 쉽게 서비스 받을 수 있도록 하였다.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.379-380
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• 2006

Recently, in spindle motors for hard disk drive (HDD) devices, fluid dynamic bearings (FDB) with herringbone grooves have come to be used instead of ball bearings due to the demand for high density recording of the devices etc. In this study, a 5-lobe bearing with high bearing stiffness using a sintered material was developed, and the bearing performance was examined by simulated calculations and experiments. As a result, it was clarified that the 5-lobe bearing had the required performance for practical use in the spindle motor for HDD