• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.27 no.3
• /
• pp.37-44
• /
• 2004

국내 반도체 산업은 불과 20년도 안 되는 짧은 기간동안에 괄목할만한 성장을 하여 전세계 반도체 생산 규모 면에서 3위 국가로 부상하였으며, 기술 경쟁력 면에서도 한국인의 자존심을 그나마 지켜왔다. 하지만, 반도체 제조는 가장 복잡한 제조공정의 하나로 분류되며, 이러한 복잡한 시스템을 통제하기 위해서는, 다양한 시스템 조건 하에서 적절한 생산전략을 마련하는 것이 필요하다. 그러나, 반도체 제조 시스템에 대한 다양한 상황과 관련한 연구는 많지 않다. 반도체 제조공정 시스템에 대한 스케줄은 생산공정의 재진입, 공정의 높은 불확실성, 급속하게 변하는 제품과 기술과 같은 특성 때문에 반도체 제조공정 시스템에 대한 스케줄은 복잡하고 어려운 작업이며, 사이클타임의 절감 및 단위시간당 생산량의 증대와 같은 시스템 목적을 달성하기 위하여, 반도체 제조 시스템에 대한 좋은 방법을 발견하기 위한 많은 연구가 있었다. 반도체 산업의 생산 흐름은 가장 독특한 특징을 가지고 있으며 생산계획과 반도체 제조의 스케줄링과 계획을 어렵게 하고 있다. 현재 반도체 조립공정에서 수행되고 있는 일정계획은 단순 FCFS (First Come First Serve)에 의한 할당규칙에 따른다. 또한 Backlog(예비재고)를 1일 생산량을 기준으로 Buffer로 운영하고 있다. 따라서 본 연구에서는 효율적인 재고관리와 정확한 스케줄링이 생산의 경쟁력 확보 우위임을 가정하여 다양한 할당규칙(dispatching rule)을 실시간 적용하여 정확한 일정계획 수립의 효과와 결과를 시뮬레이션을 통해 검증하고자 한다. 제시된 방법론을 위하여 시뮬레이션 접근방법이 사용되었다.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.33 no.3
• /
• pp.162-168
• /
• 2010

Information is known to be a key element for the successful operation of a supply chain, which is required of the efficient ordering strategies and accurate predictions of demands. This study proposes a method to effectively utilize the meteorological forecast information in order to make decisions about ordering and prediction of demands by using the Taguchi experimental design. It is supposed that each echelon in a supply chain determines the order quantity with the prediction of precipitation in the next day based on probability forecast information. The precipitation event is predicted when the probability of the precipitation exceeds a chosen threshold. Accordingly, the choice of the threshold affect the performances of a supply chain. The Taguchi method is adopted to deduce a set of thresholds for echelons which is least sensitive to changes in environmental conditions, such as variability of demand distributions and production periods. A simulation of the beer distribution game was conducted to show that the set of thresholds found by the Taguchi method can reduce the cumulative chain cost, which consists of inventory and backlog costs.

• Journal of Information Technology Applications and Management
• /
• v.14 no.4
• /
• pp.139-158
• /
• 2007

Information sharing is key to effective supply chain management. In reality, however, it is impossible to get perfect information. Accordingly, only uncertain information can be accessed in business environment, and thus it is important to deal with the uncertainties of information in managing supply chains. This study adopts meteorological forecast as a typical uncertain information. The meteorological events may affect the demands for various weather-sensitive goods, such as beer, ices, clothes, electricity etc. In this study, a beer distribution game is modified by introducing meterological forecast information provided in a probabilistic format. The behavior patterns of the modified beer supply chains are investigated. for two conditions using the weather forecast with or without an information sharing. A value score is introduced to generalize the well-known performance measures employed in the study of supply chains, i.e.. inventory, backlog, and deviation of orders. The simulation result showed that meterological forecast information used in an information sharing environment was more effective than without information sharing, which emphasizes the synergy of uncertain information added to the information sharing environment.

• Current Industrial and Technological Trends in Aerospace
• /
• v.9 no.1
• /
• pp.15-26
• /
• 2011

The airliners are replacing their old fleet by brand new ones while the air traffic has recovered from the great recession. And the delivery and the backlog get almost highest record still in 2010. The single aisle leads the market and it will show harder competition with more efficient challengers. The recent strong demand of new aircraft reduces MRO and lease market and it makes some worries about the bubble in civil aircraft industry. In the long time forecast, the civil aircraft industry will grow steadily with over 60,000 delivery for 20 years. and the commercial aircraft market will be about 31,000~34,000 of them. And the emerging market will lead the growth.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2013.06a
• /
• pp.209-213
• /
• 2013

The expense Our country's land logistics system is becoming backlog day by day. The greenhouse gas which it discharges specially from the vehicle causes a ecocide and traffic expense to make. The traffic energy curtailment which the government enforces during that time and environment-friendly green goods policy lost the effect. Therefore, This research propose the car-ferri network which is the most effective logistics system substitutes the land logistics system. This research will contribute improving the north and south logistics network of Pusan and Seoul region and will be able to reduce a various goods expense.

• Smart Media Journal
• /
• v.10 no.4
• /
• pp.80-90
• /
• 2021

Using optical music recognition technology based on deep learning, we propose to apply the results derived to VR games. To detect the music objects in the music sheet, the deep learning model used YOLO v5, and Hough transform was employed to detect undetected objects, modifying the size of the staff. It analyzes and uses BPM, maximum number of combos, and musical notes in VR games using output result files, and prevents the backlog of notes through Object Pooling technology for resource management. In this paper, VR games can be produced with music elements derived from optical music recognition technology to expand the utilization of optical music recognition along with providing VR contents.

• Electronics and Telecommunications Trends
• /
• v.38 no.5
• /
• pp.34-50
• /
• 2023

Quantum error correction is a key technology for achieving fault-tolerant quantum computation. Finding the best decoding solution to a single error syndrome pattern counteracting multiple errors is an NP-hard problem. Consequently, error decoding is one of the most expensive processes to protect the information in a logical qubit. Recent research on quantum error decoding has been focused on developing conventional and neural-network-based decoding algorithms to satisfy accuracy, speed, and scalability requirements. Although conventional decoding methods have notably improved accuracy in short codes, they face many challenges regarding speed and scalability in long codes. To overcome such problems, machine learning has been extensively applied to neural-network-based error decoding with meaningful results. Nevertheless, when using neural-network-based decoders alone, the learning cost grows exponentially with the code size. To prevent this problem, hierarchical error decoding has been devised by combining conventional and neural-network-based decoders. In addition, research on quantum error decoding is aimed at reducing the spacetime decoding cost and solving the backlog problem caused by decoding delays when using hardware-implemented decoders in cryogenic environments. We review the latest research trends in decoders for quantum error correction with high accuracy, neural-network-based quantum error decoders with high speed and scalability, and hardware-based quantum error decoders implemented in real qubit operating environments.

• Journal of the Korean Solar Energy Society
• /
• v.30 no.3
• /
• pp.65-70
• /
• 2010

As for the present wind power industry, most of the computerization for monitoring and control is based on the traditional development methodology, but it is necessary to improve SCADA system since it has a phenomenon of backlog accumulation in the applicable aspect of back-data as well as in the operational aspect in the future. Especially for a system like offshore wind power where a superintendent cannot reside, it is desirable to operate a remote control system. Therefore, it is essential to establish a monitoring system with appropriate control and monitoring inevitably premised on the integrity and independence of data. As a result, a study was carried out on the modeling of offshore wind power data-centered database. In this paper, a logical data modeling method was proposed and designed to establish the database of offshore wind power. In order for designing the logical data modeling of an offshore wind power system, this study carried out an analysis of design elements for the database of offshore wind power and described considerations and problems as well. Through a comparative analysis of the final database of the newly-designed off-shore wind power system against the existing SCADA System, this study proposed a new direction to bring about progress toward a smart wind power system, showing a possibility of a service-oriented smart wind power system, such as future prediction, hindrance-cause examination and fault analyses, through the database integrating various control signals, geographical information and data about surrounding environments.

• Journal of Digital Convergence
• /
• v.14 no.11
• /
• pp.297-304
• /
• 2016

The aim of the study is to combine software reuse with agile methods through reuse in the early stage of agile development. Although agile methods and software reuse have different practices and principles, these methods have common goals, such as reducing development time and costs and improving productivity. Both approaches are expected to serve as viable solutions to the demand for fast development or embracing requirement changes in the rapidly changing environments. In the present paper, we identify economical agile reuse and its type and study a reuse technique for input queue in Kanban board at the early stage of hybrid agile methods. Based on our results, we can integrate software reuse with agile methods by backlog factoring for input queue item in the hybrid Scrum and Kanban method. The proposed technique can be effectively applied to e-class applications and can reuse the input queue items, showing the combination of the two approaches. With this study, we intend to contribute to reuse in the early stage of agile development. In the future, we plan to develop a software tool for economical agile reuse.

• Structural Monitoring and Maintenance
• /
• v.2 no.3
• /
• pp.283-300
• /
• 2015

Visual condition inspections remain paramount to assessing the current deterioration status of a bridge and assigning remediation or maintenance tasks so as to ensure the ongoing serviceability of the structure. However, in recent years, there has been an increasing backlog of maintenance activities. Existing research reveals that this is attributable to the labour-intensive, subjective and disruptive nature of the current bridge inspection method. Current processes ultimately require lane closures, traffic guidance schemes and inspection equipment. This not only increases the whole-of-life costs of the bridge, but also increases the risk to the travelling public as issues affecting the structural integrity may go unaddressed. As a tool for bridge condition inspections, Unmanned Aerial Vehicles (UAVs) or, drones, offer considerable potential, allowing a bridge to be visually assessed without the need for inspectors to walk across the deck or utilise under-bridge inspection units. With current inspection processes placing additional strain on the existing bridge maintenance resources, the technology has the potential to significantly reduce the overall inspection costs and disruption caused to the travelling public. In addition to this, the use of automated aerial image capture enables engineers to better understand a situation through the 3D spatial context offered by UAV systems. However, the use of UAV for bridge inspection involves a number of critical issues to be resolved, including stability and accuracy of control, and safety to people. SLAM (Simultaneous Localisation and Mapping) is a technique that could be used by a UAV to build a map of the bridge underneath, while simultaneously determining its location on the constructed map. While there are considerable economic and risk-related benefits created through introducing entirely new ways of inspecting bridges and visualising information, there also remain hindrances to the wider deployment of UAVs. This study is to provide a context for use of UAVs for conducting visual bridge inspections, in addition to addressing the obstacles that are required to be overcome in order for the technology to be integrated into current practice.