• Journal of the Korea Society of Computer and Information
• /
• v.11 no.2 s.40
• /
• pp.319-327
• /
• 2006

Higher grade elementary school students who have superior cognitive abilities need education of basic principles of computer or programming rather than computer in education. In this study, all the errors occurring while elementary school students wrote and executed programs were collected. in the method of predicting and dealing with possible-to-occur problems on programming education of the higher grades (4th, 5th and 6th grades) during their optional special activities or during talent aptitude activities after school, classified by type and analyzed. If the errors analyzed are put to practical use, optimal programming curriculums could be written and such curriculums could be a great contribution to induction of learning effect and interest on teaching learning. It was found by analyzing the errors collected for this study that the most of elementary school students during programming felt difficulties in simple errors by poor use of software and in simple coding by poor use of reserved words in English. In the next, students occurred errors by difficulties in understanding grammar. It was exposed that these error types were the opposite phenomena to those analyzed by commercial software developing companies, however, it is predicted that if teaching learning is setting improved, the same phenomena could be found desirably.

• Journal of the Korea Society of Computer and Information
• /
• v.17 no.6
• /
• pp.49-55
• /
• 2012

Pacman is one of the world-famous and have been chosen game in the game room at the arcade. In this paper, pacman game gives you the ability to perform by simple hand movement alone. First, we obtain binary RGB image to extract skin color, and convert into binary image YCbCr by minus the luminance in this image. Next, we extract the hand region by the product of an binary RGB image and binary YCbCr image. Finally, the hand region, we obtain the center of gravity by the minimum bounding rectangle and the center of the hand pixel area, and we used to obtain the center of the hand area with an average of two center of gravity. In other words, we presented the game of motion that can take the place of arrow key by using the center coordinates of hand. In addition, these experiments showed the average movement and error rate, and cause of the error type was also investigated.

• Journal of the Korea Computer Graphics Society
• /
• v.3 no.2
• /
• pp.1-13
• /
• 1997

Two factors are required for a virtual reality system; realism and immersion. Since realism is determined primarily by the realistic image, objects in a virtual environment should be represented with details by their own characteristics. Also, reflection on light must be considered. On the other hand, immersion is defined as realistic movements and fast interactions. Thus, virtual environment should be rendered as fast as possibl. Regular frame rate should also be kept to make moves as intended by the user. In a complex virtual environment composed of objects with various levels, the appropriate level for individual object should be assigned according to the view point, in other words, the selection of level-of-detail is needed. In this paper, the problem of determining the levels of detail is formalized in terms of error, cost and L -distance. Error is defined as the difference between the current level image and the highest level image, cost as rendering time, and L-distance as the level difference between the previous and the current level. To solve this problem, a new method called the well-distributed adaptive algorithmis proposed.

• Journal of the Korea Convergence Society
• /
• v.11 no.5
• /
• pp.1-8
• /
• 2020

Machine translation refers to a system where a computer translates a source sentence into a target sentence. There are various subfields of machine translation. APE (Automatic Post Editing) is a subfield of machine translation that produces better translations by editing the output of machine translation systems. In other words, it means the process of correcting errors included in the translations generated by the machine translation system to make proofreading. Rather than changing the machine translation model, this is a research field to improve the translation quality by correcting the result sentence of the machine translation system. Since 2015, APE has been selected for the WMT Shaed Task. and the performance evaluation uses TER (Translation Error Rate). Due to this, various studies on the APE model have been published recently, and this paper deals with the latest research trends in the field of APE.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.18 no.1 s.116
• /
• pp.53-61
• /
• 2007

This paper researches on the scheme superimposing the rotation phases over the pilot and data symbols in order to reduce the peak-to-average power ratio(PAPR) of the orthogonal frequency division multiplexing(OFDM) communication. The bandwidth and power efficiency are the main consideration. The phases of rotation vector are added to those of both pilot symbols and data symbols interlaying between any two pilot symbols in an OFDM block. Owing to this scheme the transmitter reduces the PAPR using the partial transmit sequences(PTS) and the receiver restores the data symbol utilizing the channel estimation of pilot symbols. Therefore, the bandwidth efficiency is accomplished by not using the further subcarriers for the reduction of PAPR and the enormous increase of bit error rate according to the receiving error of the side information, i.e. the phases of rotation vector, is prevented. In other words, both bandwidth-and power-efficiency and quality of communication performance can be improved.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.12 no.11
• /
• pp.833-839
• /
• 2002

As the demand for slim laptops requires low-height optical disc drives, vibration problems of optical disc drives are of great concern. Additionally, with the decrease of a track width and a depth of focus in high density drives, studies on vibration resonance between mechanical parts become more important. From the vibration point of view, the performance of optical disc drives is closely related with the relative displacement between a disc and an objective lens which is controlled by servo mechanism. In other words, to read and write data properly, the relative displacement between an optical disc and an objective lens should be within a certain limit. The relative displacement is dependent on not only an anti-vibration mechanism design but also servo control capability. Good servo controls can make compensation for poor mechanisms, and vice versa. In a usual development process, robustness of the anti-vibration mechanism is always verified with the servo control of an objective lens. Engineers partially modify servo gain margin in case of a data reading error. This modification cannot correct the data reading error occasionally and the mechanism should be redesigned more robustly. Therefore it is necessary to verify a mechanism with respect to the possible servo gain plot. In this study we propose the experimental verification method for anti-vibration mechanism with respect to the existing servo gain plot. Thismethod verifies axial vibration characteristics of optical disc drives on the basis of transmissibility. Using this method, we verified our mechanism and modified the mechanism for better anti-vibration characteristics.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.44 no.1
• /
• pp.26-36
• /
• 2021

The topic of this study is the field of humanitarian logistics for disaster response. Many existing studies have revealed that compliance with the golden time in response to a disaster determines the success or failure of relief activities, and logistics costs account for 80% of the disaster response cost. Besides, the agility, responsiveness, and effectiveness of the humanitarian logistics system are emphasized in consideration of the disaster situation's characteristics, such as the urgency of life-saving and rapid environmental changes. In other words, they emphasize the importance of logistics activities in disaster response, which includes the effective and efficient distribution of relief supplies. This study proposes a mathematical model for establishing a transport plan to distribute relief supplies in a disaster situation. To determine vehicles' route and the amount of relief for cities suffering a disaster, it mainly considers the urgency, effectiveness (restoration rate), and uncertainty in the logistics system. The model is initially developed as a mixed-integer nonlinear programming (MINLP) model containing some nonlinear functions and transform into a Mixed-integer linear programming (MILP) model using a logarithmic transformation and piecewise linear approximation method. Furthermore, a minimax problem is suggested to search for breakpoints and slopes to define a piecewise linear function that minimizes the linear approximation error. A numerical experiment is performed to verify the MILP model, and linear approximation error is also analyzed in the experiment.

• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.3156-3159
• /
• 2011

In case of the continuous welded rail(CWR) track is supported by the railway bridge, the additional axial force is occurred in the CWR due to the track-bridge interaction. In the various design codes such as Korean code, European code, UIC code, etc, three important loads(temperature variation in the bridge-deck, braking/acceleration and the bending of the bridge-deck resulted from the passing train) are treated as the independent loading case. In other words, the additional axial force can be obtained by summing up the three different values calculated by the three independent analysis. However, this analysing method may have an error because the behavior of the longitudinal resistance between the rail and the bridge-deck is under the highly nonlinear. Therefore, in order to exactly analyse the track-bridge interaction, nonlinear loading history and the change of the longitudinal resistance owing to the loading history must be considered in the analysis process. In this study, the loading history effect on the track-bridge interaction is investigated considering the resonable combination of three loads and the longitudinal resistance change.

• Journal of Cadastre & Land InformatiX
• /
• v.44 no.1
• /
• pp.165-177
• /
• 2014

The KML verification tool supports people who want to produce the highest quality KML file. In other words, it validate that a given KML document is well-formed with respect to XML standard meaning, and conform not only to the KML schema and the specification. Then it's only to notify error code line. People who want to use the KML file written by others would like to know both whether the validity of that file and general summary of feature's location, shape, and number. In this study, we recommended the user-friendly KML validator using OpenLayers and reporting geometries and images of the KML file.

• Journal of Korean Institute of Industrial Engineers
• /
• v.35 no.1
• /
• pp.109-118
• /
• 2009

While driving, the manual use of a mobile phone is heavily restricted due to the interference with the primary driving task. An alternative would be the use of speech interface. The current study aims to provide a guideline to implementation of a speech interface to the mobile phone. To do so, an expert evaluation was made and it revealed that a speech interface requires less workload, less performance degradation of the driving task than that of the keypad interface. To make speech interfaces more usable, new improvements are suggested. Subjective workload can be reduced and user satisfaction can be improved without degrading the primary task performance, for instance, by letting the user interrupt the speech of the phone, eliminating the repetitive words, letting the user know clearly what makes an error, providing a way to go back to the previous state, reducing the usage of keypad buttons and reducing the amount of the information on the screen.