• Korean Management Science Review
• /
• v.30 no.1
• /
• pp.1-14
• /
• 2013

We conduct the future studies suggested by Park and Seo [3]. They considered a seat inventory control problem in which flights depart sequentially during a similar time-interval and passengers purchase available seats depending on individual customer choice behavior. Customer choice behavior can lead to one among a horizontal shift, a diversion-up, and a booking loss when a desired fare class is unavailable. We investigate how seat availability calculation method, booking limit control mechanism, seat inventory capacity, number of booking class, type of seat demand influence on revenues in an airline industry through thorough computer simulation experiments.

• International Journal of Internet, Broadcasting and Communication
• /
• v.6 no.1
• /
• pp.5-8
• /
• 2014

Social networking services that connect a person to other people are attracting our attention and various types of on-the-network services are provided. Library has been playing a role of social media by providing with materials such as books and magazines, and with a place for reading, studying, getting lectures, etc. In this paper, we present a method for finding candidates of groups of the library's patrons who share interest areas by utilizing the loan records, which are obtainable by every library. Such a homogeneous group can become a candidate for a study group, a community for exchange ideas, and other activity group. We apply the method to a collection of loan records of a university library, find some problem to be solved, and propose measures for more detailed solutions. Even though the potential group finding problem still remains a lot of problems to be solved, its potential importance is very high and thus to be studies even more for future applications.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.13 no.6
• /
• pp.1153-1171
• /
• 2010

Hydrogen is the most abundant element in the universe. Although hydrogen can produce three times more energy than gasoline and seven times than coal, the most challenging problem in utilizing hydrogen as energy carrier is its storage problem. In contrast to the liquid hydrocarbon, hydrogen can not be stored or transported easily and safely because of its extremely low boiling point(21K). Recently scientists have made a tremendous achievement in storing hydrogen capacity in solid state materials such as carbon based and metal organic frameworks materials as well as metal hydrides. In this review the author reviewed the status of the hydrogen storage technologies in solid state, the advantages and disadvantages in each category of materials and the future prospects of hydrogen storage.

• Proceedings of the KIEE Conference
• /
• 2003.07a
• /
• pp.46-49
• /
• 2003

This paper proposes a method to solve expansion problem for a transmission network, given future generation and load strategy, and alternative types of lines available, subject to load, reliability and right of way constraints, the problem is formulated as a series of zero one integer programs which are solved by an efficient branch and bound algorithm A study test result on the 63-buses test system shows that the proposed method is practical and efficiently applicable to the transmission expansion planning.

• IE interfaces
• /
• v.9 no.3
• /
• pp.257-268
• /
• 1996

This paper illustrates the process of developing and configuring the prototype Computer Analysis System for Controlling Occupational WORKload (CAS-COWORK). The software interface between the database and expert system was attempted. The database is used for storing and retrieving series of data entered by general users and the expert system is used for identifying and solving occupational problem areas. Two theories were applied in developing the algorithm base of CAS-COWORK that were used to calculate overall workload stress level. The fuzzy set theory was introduced to capture the subject‘s workload stress perception. The Analytic Hierarchy Process (AHP) was introduced to estimate the importance of the task and workplace variables. The purpose of the system development is for future prediction and problem solving which would be highly valuable to the industrial engineer.

• Journal of Fisheries and Marine Sciences Education
• /
• v.24 no.1
• /
• pp.25-33
• /
• 2012

Though science and technology are evolving rapidly in recent years, the traditional science education has limits for students to be satisfied their interests and needs because they couldn't follow these speeds. STEAM as a education integrating science, technology, engineering, arts and mathematics has strengths of increasing interests and understandings in science and technology and improving integrated thinking and problem solving ability for leaners. In this study we analyze the elementary school curriculum and construct physics learning based on STEAM and develop a android application to increase interests in science and improve problem solving ability. In the future, we need to analyze and develop the curriculum and contents for the STEAM education.

• 제어로봇시스템학회:학술대회논문집
• /
• 1998.10a
• /
• pp.312-317
• /
• 1998

Reliable maintenance scheduling of main equipments is a crucial problem in thermal power stations in order to skirt overall losses of power generation resulted from severe failures of the equipments. A reasonable method was proposed to determine the maintenance scheduling of whole pump system in thermal power stations in order to reduce the maintenance cost by keeping the present avail-ability of the pump system throughout the operation. The dimensional reduction method was used to solve problems encountered due to few data which involved many operational factors in failure rate of pumps. The problem of bandlimited nature of data with time was solved by extrapolating future failures from presently available actual data with an aid of Weibull distribution. The results of the analysis identified the most suitable maintenance intervals of each pump type accordingly and hence reduce the cost of unnecessary maintenance with an acceptable range in the overall system availability.

• IEIE Transactions on Smart Processing and Computing
• /
• v.4 no.4
• /
• pp.281-290
• /
• 2015

Human action recognition from a video scene has remained a challenging problem in the area of computer vision and pattern recognition. The development of the low-cost RGB depth camera (RGB-D) allows new opportunities to solve the problem of human action recognition. In this paper, we present a comprehensive review of recent approaches to human action recognition based on depth maps, skeleton joints, and other hybrid approaches. In particular, we focus on the advantages and limitations of the existing approaches and on future directions.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.24 no.62
• /
• pp.11-20
• /
• 2001

At the initial deployment of B-ISDN, the heterogeneity of services and the bandwidth requirement make dimensioning of B-ISDN much more complicated than the dimensioning of homogeneous circuit or packet switched networks. Therefore B-ISDN must be extended gradually according to future telecommunication technology or service demands. In this paper, we propose a mathematical formulation for dimensioning problem of B-ISDN extension, considering the characteristics of ATM(Asynchronous Transfer Mode) such as various quality of services, the statistical multiplexing effects of VPCs(Virtual Path Connections) and the modularity of transmission links allocated when new B-ISDN nodes are given. The algorithm based on the simultaneous linear approximation technique and Lagrangian relaxation method and some numerical results are also presented.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.53 no.8
• /
• pp.484-489
• /
• 2004

When the energy resource available to a particular plant (be it coal, oil, gas, water, or nuclear fuel) is a limiting factor in the operation of the plant, the entire economic dispatch calculation must be done differently. Each economic dispatch calculation must account for what happened before and what will happen in the future. This paper presents a formulation and a solution method for the optimization problem with a fuel constraint in a competitive electricity market. Take-or- Pay (TOP) contract for an energy resource is the typical constraint as a limiting factor. Two approaches are proposed in this paper for modeling the dispatch calculation in a market mechanism. The approaches differ in the subject who considers and inserts the fuel-constraint into its optimization problem. Market operator and each power producer having a TOP contract are assumed as such subjects. The two approaches are compared from the viewpoint of profits. surplus. and social welfare on the basis of Nash Equilibrium.