• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.11
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• pp.787-794
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• 2019

In this paper, a Mixed Integer Linear Programming(MILP) approach for solving optimal Weapon-Target Assignment(WTA) problem of multiple dissimilar Closed-In Weapon Systems (CIWS) is proposed. Generally, WTA problems are formulated in nonlinear mixed integer optimization form, which often requires impractical exhaustive search to optimize. However, transforming the problem into a structured MILP problem enables global optimization with an acceptable computational load. The problem of interest considers defense against several threats approaching the asset from various directions, with different time of arrival. Moreover, we consider multiple dissimilar CIWSs defending the asset. We derive a MILP form of the given nonlinear WTA problem. The formulated MILP problem is implemented with a commercial optimizer, and the optimization result is proposed.

• Journal of the Korean School Mathematics Society
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• v.2 no.1
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• pp.219-229
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• 1999

Nowadays the use of computer has a tendency to be being increased in classroom. Also, Many mathematics teachers are attempting to use computer efficiently in classroom. Computer has unique functions such as graphic, animation, and error correction. As graphic and animation can make the content of mathematics visible and make it easy for learners to study mathematics, it is desirable to develop the computer educational program and use it in teaching and learning mathematics. Especially, before concepts study on the unit of Figure or Function, the use of graphic or animation is efficient by being able to understand easily the content. The purpose of this thesis is to produce the computer program on the Movement of Figure in the unit of Equation of Figure which is in mathematics curriculum for the first grade of high school. In teaching and learning mathematics by use of this program, the educational effects are expected as follows: 1. It is expected that this program will stimulate the interest of learners by using animation and acoustic (sound) effect and so learners' voluntary and active thinking activity will be shown. 2. It will be helpful to form exact concept because it is possible to understand intuitively the basic concepts on the Movement of Figure by using graphic and animation. 3. It is expected that the repeated study of this program already designed will remove the fear of incomplete parts and help review them. 4. It is possible to change from teacher-centered instruction, which is the blind point of recent mathematics education, to the learner-centered instruction. However, it is necessary to realize that using the educational engineering (computer) in mathematics education cannot always cause learners to study mathematics very well and that computer cannot take the place of mathematics teacher. Accordingly, computer will be treated as aids which help learners study difficult part.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.207.1-207.1
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• 2014

High-mobility and two dimensional conduction at the interface between two band insulators, LaAlO3 (LAO) and SrTiO3 (STO), have attracted considerable research interest for both applications and fundamental understanding. Several groups have reported the photoconductivity of LAO/STO, which give us lots of potential development of optoelectronic applications using the oxide interface. Recently, a giant photo response of Pd nano particles/LAO/STO is observed in UV illumination compared with LAO/STO sample. These phenomena have been suggested that the correlation between the interface and the surface states significantly affect local charge modification and resulting electrical transport. Water and gas adsorption/desorption can alter the band alignment and surface workfunction. Therefore, characterizing and manipulating the electric charges in these materials (electrons and ions) are crucial for investigating the physics of metal oxide. Proposed mechanism do not well explain the experimental data in various ambient and there has been no quantitative work to confirm these mechanism. Here, we have investigated UV photo response in various ambient by performing transport and Kelvin probe force microscopy measurements simultaneously. We found that Pd nano particles on LAO can form Schottky contact, it cause interface carrier density and characteristics of persistence photo conductance depending on gas environment. Our studies will help to improve our understanding on the intriguing physical properties providing an important role in many enhanced light sensing and gas sensing applications as a catalytic material in different kinds of metal oxide systems.

• The Journal of Korean Institute for Practical Engineering Education
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• v.2 no.2
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• pp.68-73
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• 2010

For engineers in the knowledge-based society of the 21st century, not only the specialty in their major field, but also the capabilities of creative thinking/reading/writing, of communication and of understanding society/business/economy, and the knowledge of specialized liberal arts, like ethics, are required. For the specialized liberal arts knowledge, it is important to have interest in a field, read the relevant literature, and summarize and express thoughts, but in reality, it is difficult to accomplish a higher level of learning outcome within the limited regular curriculum. In this study, an application for smart phones that purports to cultivate the specialized liberal arts knowledge of the students enrolled in the college of engineering was developed and applied to classes. Under this environment, a teacher can interact with teacher's students through the structured knowledge on a real-time basis in any place at any time, and the students can reorganize the knowledge by themselves. In this way, this paper proposed a way of improving the level of specialized liberal arts knowledge in daily life.

• Korean Institute of Interior Design Journal
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• v.17 no.5
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• pp.150-156
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• 2008

The 'Environmental Psychology and Behavior Studies' which started from the purpose of "Building the comfortable environment for people", is one of the most essential research area in architecture and intoner design field because of the basis of humanbeing matters. As the development of science and industries, the social circumstances have been more complicated and diversified. As a result, humanbeing require much humanized and high level of quality in space design as well as environmental design. In case of domestic research situation, the research of environmental psychology and behavior studies in architecture and interior design fields, haven't been applied fully in their potential abilities due to the shortage of research history, complexity of humanbeing researches and the vagueness of studies as a major fields. Thus, my purpose of studying is to analizing the previous research tendencies focus on the domestic thesis since 1980 to 2006 from the related research Institutes. Final findings are as follows ; 1. Steadily increasing tile interest ratio of the research field of environmental psychology and behavior studies 2. Concentration of research target spaces are higher from the residential > elderly facilities > educational > and medical spaces. 3. The preference of research theme showed the environmental psychology fundamentals > behavior studies > general studies of environmental psychology > emotional engineering > human factors engineering. 4. Results of crossing analysis ; 1)Residential spaces were the main spaces for main research theme. 2)Main theme used in target spaces were 'environmental psychology fundamentals' and "behavior studies'. 3)Main research methods for the most target spaces were 'sample research' methods.

• Korean Institute of Interior Design Journal
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• v.19 no.3
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• pp.162-171
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• 2010

In the field of architecture, the sustainable architectural concept, "green buildings," has been suggested as an alternative to solve the environmental problems; however, the concept has not yet been converted to awareness and development of related technology. The leading role of public sector has been socially and economically influential in the nation, hence green public buildings are significant to stimulate the spread of green buildings in the nation. This study is to draw an appropriate method of implementing the green building concept to the two main government office buildings of Jeju Special Self-Governing Province based on the plan to improve the work environment; it is also to provide long-term directions of implementing policies and reference for the public and private sector to utilize the green building concept. Its research methodology was the survey method. A total of 142 questionnaires were returned by government employees of the two buildings. It accounts for 20% of the total number of 711 workers of the buildings. According to the analysis of the returned questionnaire, the majority of the surveyed have a positive evaluurned toward the introduction of green buildings due to their expecturned for the possible i the buildingstheir work environment. In addition, they showed more interest in space planning with natural ventilation than automatic systems regarding applied methods for green buildings.

• Journal of Information Technology Services
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• v.13 no.3
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• pp.221-233
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• 2014

Because people's interest of the stock market has been increased with the development of economy, a lot of studies have been going to predict fluctuation of stock prices. Latterly many studies have been made using scientific and technological method among the various forecasting method, and also data using for study are becoming diverse. So, in this paper we propose stock prices prediction models using sentiment analysis and machine learning based on news articles and SNS data to improve the accuracy of prediction of stock prices. Stock prices prediction models that we propose are generated through the four-step process that contain data collection, sentiment dictionary construction, sentiment analysis, and machine learning. The data have been collected to target newspapers related to economy in the case of news article and to target twitter in the case of SNS data. Sentiment dictionary was built using news articles among the collected data, and we utilize it to process sentiment analysis. In machine learning phase, we generate prediction models using various techniques of classification and the data that was made through sentiment analysis. After generating prediction models, we conducted 10-fold cross-validation to measure the performance of they. The experimental result showed that accuracy is over 80% in a number of ways and F1 score is closer to 0.8. The result can be seen as significantly enhanced result compared with conventional researches utilizing opinion mining or data mining techniques.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.719-723
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• 2016

Owing to the recent increased interest in wireless communication technology and rapid technology development, a range of applied technologies utilizing them are being released. In addition, at school, by adopting an attendance management system using wireless communication technology, attempts to solve problems caused by attendance books are being made. Representative attendance management systems include those using RFID, Bluetooth and clicker. Although these systems have solved the problem of wasting paper and time due to calling and writing attendance, they have other problems of generating additional expenses of purchasing or renting more equipment. To solve all of these problems, this paper suggests prototype system that can manage attendance by using NFC (Near Field Communication), which most smartphones provide. The attendance management system using NFC consists of two applications; one for professors and the other for students. The system solves problems, such as proxy attendance, loss of lesson time and additional cost by automatically managing attendance information using NFC and TCP/IP technologies.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.12
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• pp.1113-1118
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• 2012

Smart grid and intelligent transportation system draw significant interest since they are considered as one of the green technologies. These systems require a large number of sensors, actuators, and controllers. Also, machine-to-machine (M2M) communications is important because of the automatic control. The LTE-Advanced networks is preparing a set of functions that facilitate the M2M communications, and particularly the development of an efficient call admission control mechanism is critical. A method that groups MTC devices according to QoS constraints and determines the admission depending on the QoS satisfaction is limitedly applied only if the data transmission period and the maximum delay are identical. This paper proposed a call admission control that is free from such limitation and also optimizes the admission process under the certain condition of the transmission period and maximum delay. The theorems regarding the proposed method are presented with the proofs. The simulations confirms its validity and shows it is better in call admission probability than existing works.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.11
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• pp.1036-1044
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• 2012

Thanks to progressive development of IT technology, the number of intelligent devices communicating each other through an In-Vehicle Network(IVN) has been steadily increasing. It is expected that the required network bandwidth and network nodes for vehicle control in 2015 will be increased by two times and one and half times as compared to in 2010, respectively. As a result, many researchers in automotive industry has showed a significant interest on industrial Ethernets, such as EtherCAT and TTEthernet. This paper addresses an analysis on transmission delay and fault recovery performance with an EtherCAT network which is being considered as an IVN. A mathematical model based on the analysis is verified through a set of experiments using an experimental network setup.