• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.5 s.335
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• pp.63-72
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• 2005

This paper describes a new approach for the operating system level power management to reduce the energy consumed in the IO devices in a robot platform, which provides various functions such as navigation, multimedia application, and wireless communication. The policy proposed in the paper, which was named the Energy-Aware Job Schedule (EAJS), rearranges the jobs scattered so that the idle periods of the devices are clustered into a time period and the devices are shut down during their idle period. The EAJS selects a schedule that consumes the minimum energyamong the schedules that satisfy the buffer and time constraints. Note that the burst job execution needs a larger memory buffer and causes a longer time delay from generating the job request until to finishing it. A prototype of the EAJS is implemented on the Linux kernel that manages the robot system. The experiment results show that a maximum $44\%$ power saving on a DSP and a wireless LAN card can be obtained with the EAJS.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.6
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• pp.165-175
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• 2016

A data allocation technique is essential to improve the performance of data broadcast systems. This paper explores the issues for allocating data items on broadcast channels to process multiple-data queries in the environment where query profiles and query request rates are given, and proposes a new data allocation scheme named QBDA. The proposed scheme allows the query with higher request rate to have higher priority to schedule its data items and introduces the concept of marking to reduce data conflicts. Simulation is performed to evaluate the performance of QBDA. The simulation results show that the proposed scheme outperforms other schemes in terms of the average response time since it can process queries with high request rate fast and show a very desirable characteristics in the aspects of query data adjacency and data conflict probability.

• Journal of Internet Computing and Services
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• v.1 no.2
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• pp.19-28
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• 2000

The scheduling problem in parallel processing systems has been a challenging research issue for decades. The problem is defined as finding an optimal schedule which minimizes the parallel execution time of an application on a target multiprocessor system. Duplication Based Scheduling (DBS) is a relatively new approach for solving the problem. The DBS algorithms are capable of reducing communication overhead by duplicating remote parent tasks on local processors. Most of DBS algorithms assume an availability of the unlimited number of processors in the system. Since the assumption may net hold in practice, the paper proposes a new scalable DBS algorithm for a target system with limited number of processors. It Is shown that the proposed algorithm with N available processors generates the same schedule as that obtained by the algorithm with unlimited number of processors, where N is the number of input tasks. Also, the performance evaluation reveals that the proposed algorithm shows a graceful performance degradation as the number of available processors in the system is decreased.

• Journal of Broadcast Engineering
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• v.14 no.5
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• pp.625-637
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• 2009

With advent of TV environment and increasing of variety of program contents, users are able to experience more various and complex environment for watching TV contents. According to the change of content watching environment, users have to make more efforts to choose his/her interested TV program contents or TV channels than before. Also, the users usually watch the TV program contents with their own regular way. So, in this paper, we suggests personalized TV program schedule recommendation system based on the analyzing users' TV watching history data. And we extract the users' watched program patterns using the sequential pattern mining method. Also, we proposed a new sequential pattern mining which is suitable for TV watching environment and verify our proposed method have better performance than existing sequential pattern mining method in our application area. In the future, we will consider a VoD characteristic for extending to IPTV program schedule recommendation system.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.430-433
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• 2003

Cost, schedule, quality are the essential parts of success of every construction project. It is especially true in high-rise building construction. Among the construction components in high-rise building construction, curtain walls are very important elements for the project success because they take large portion of cost and schedule. However, curtain wall construction process are very complicated, where many entities including designers, suppliers, contractors and even maintenance contractors are involved. Therefore, control and management of their relationships and production process are critical. It is suggested that this can be solved by the concept of Supply Chain Management which is supported by the automated information technology with Radio Frequency Identification. Such concept is defined as 'Automated Life-Cycle Management System Based On SCM' and this study suggests rode map to establish the system.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.904-913
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• 2005

This paper deals with an integrated problem of inventory control and dynamic pricing strategies for a commodity with price and sales-period dependent demand pattern, where a seller and customers have complete information of each other. The problem consists of two parts; one is each buyer's benefit problem which makes the best decision on price and time for buyer to purchase items, and the other one is a seller's profit problem which decides an optimal sales strategy concerned with inventory control and discount schedule. The seller's profit function consists of sales revenue and inventory holding cost functions. The two parts are closely related into each other with some related variables, so that any existing general solution methods can not be applied. Therefore, a simplified model with single seller and two customers in considered first, where demand for multiple units is allowed to each customer within a time limit. Therewith, the model is generalized for a n-customer-classes problem. To solve the proposed n-customer-set problem, a dynamic programming algorithm is derived. In the proposed dynamic programming algorithm, an intermediate profit function is used, which is computed in case of a fixed initial inventory level and then adjusted in searching for an optimal inventory level. This leads to an optimal sales strategy for a seller, which can derive an optimal decision on both an initial inventory level and a discount schedule, in $O(n^2)$ time. This result can be used for some extended problems with a small customer set and a short selling period, including sales strategy for department stores, Dutch auction for items with heavy holding cost, open tender of materials, quantity-limited sales, and cooperative buying in the on/off markets.

• The KIPS Transactions:PartD
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• v.9D no.5
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• pp.865-876
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• 2002

Successful project planning relies on a good estimation of the effort required to complete a project, together with the schedule options that may be available. Existing software effort estimation models are present only the total effort and instantaneous effort function for the software life-cycle. Also, Putnam presents constant effort rate in each phase. However, the size of total effort varies according to the software projects under the influence of its size, complexity and operational environment. As a result, the allocated effort in each phase also differs from one project to another. This paper suggests models for effort allocation in planning, specifying, building, testing and implementing phases followed by the project size and development types. These models are derived from 155 different projects. Therefore, these models can be considered as a practical guideline in management of project schedule and effort allocation.

• Journal of KIISE:Software and Applications
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• v.30 no.3_4
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• pp.293-307
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• 2003

Object-oriented development has been generalized, but object-oriented project planning and scheduling techniques have not been studied enough. Furthermore, it is difficult to apply the conventional software management techniques to object-oriented projects. Especially, the large scaled projects are increasing, but the project planing techniques for these large scaled projects have not been proposed enough. In this paper, we propose systematic techniques for OO based project scheduling. We suggest a 7 step-process for deriving the OO project schedule from the use-case diagram which is describing the functional requirements of the system. The proposed process includes identifying use-cases, drawing preliminary chart through interdependency analysis, identifying characteristics of each use case, determining the number of iteration, assigning use-cases to iteration, considering available resource and constraints, drawing revised PERT chart. Each step has the explanation of the input, output, and the guidelines needed to perform the step. The project scheduling technique proposed in this paper ran be used effectively in the planning phase which the purpose is to plan a development schedule to yield the high quality software in minimum time.

• Journal of Advanced Navigation Technology
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• v.2 no.2
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• pp.143-156
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• 1998

Incheon International Airport(IIA) is planned to open in about two years. Korean government has an ambition to make IIA a major hub airport in Northeast Asia. The most essential and required condition for an airport to be a successful hub airport in a certain region is to have more efficient flight service network than the other airports in the same region. IIA should compete with Japanese airports to be a major hub in Northeast Asia because Japanese government also has a plan to expand greatly the airport capacity in Tokyo area and Kansai airport in Osaka. It is necessary for both IIA and Korean national air carriers to compose efficient flight service network considering hub competition with Japanese major airports. As the liberalization of international air transport industry would give more marketing freedom to airlines, they would plan the flight service network and flight schedule based on market analysis instead of governmental regulations. In the economically liberalized environment, it is very required to analyze air passengers' flight choice behaviour in order to induce other carriers and passengers through IIA's attractive flight service network. Disaggregate model is more appropriate than aggregate model to analyze consumers' behaviour. The information derived from disaggregate choice model of air passengers could be utilized in devising efficient flight network and schedule plan. Value of travel time or trade off ratio between flight frequency and travel time which could be estimated from discrete choice model could be utilized for scheduling an efficient flight plan for airlines and composing efficient flight service network for IIA.

• The KIPS Transactions:PartB
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• v.11B no.7 s.96
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• pp.803-812
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• 2004

The performance of video-on-demand(VOD) systems is known to be mainly dependent on a scheduling mechanism which they employ. Broadcast-based scheduling schemes have attracted a lot of attention as an efficient way of distributing popular videos to very large client populations. The main motivations of broadcasting scheduling mechanisms are that they scale up extremely well and they have very modest bandwidth requirements. This paper studies this issue and proposes a new broadcasting scheduling mechanism, named fast universal video dis-tribution(FUVD). FUVD scheme dynamically constructs a video broadcasting schedule in response to client requests, and broadcasts video seg-ments according to this schedule. This paper also evaluates the performance of FUVD on the basis of a simulation approach. The simulation results indicate that FUVD protocol shows a superior performance over UD, CBHD, and NPB in terms of the average response time.