• Journal of KIISE:Databases
• /
• v.34 no.5
• /
• pp.448-464
• /
• 2007

Location-Based Services (LBSs) provide results to queries according to the location of the client issuing the query. In LBS, techniques such as caching and prefetching are effective approaches to reducing the data transmission from a server and query response time. However, they can lead to cache inefficiency and network overload due to the client's mobility and query pattern. To solve these drawbacks, we propose a semantic prefetching (SP) scheme using prefetching segment concept and improved cache replacement policies. When a mobile client enters a new service area, called semantic prefetching area, proposed scheme fetches the necessary semantic information from the server in advance. The mobile client maintains the information in its own cache for query processing of location-dependent data (LDD) in mobile computing environment. The performance of the proposed scheme is investigated in relation to various environmental variables, such as the mobility and query pattern of user, the distributions of LDDs and applied cache replacement strategies. Simulation results show that the proposed scheme is more efficient than the well-known existing scheme for range query and nearest neighbor query. In addition, applying the two queries dynamically to query processing improves the performance of the proposed scheme.

• Journal of Broadcast Engineering
• /
• v.15 no.2
• /
• pp.248-264
• /
• 2010

In this paper, we presents an efficient rich media framework based on MPEG-4 LASeR PMSI. Rich media provides distinctive features such as dynamic updates and object-based interactivity over the conventional AV centric media service. It rapidly gains its popularity as the convergent multimedia services between broadcasting and telecommunication. MPEG-4 LASeR is an international standard which provides specifications for such rich media services. Recently MPEG added an extension to LASeR called PMSI. It provides an efficient technique to present SI on a scene by referencing specific portions of SI from PI. The presented rich media application is using PMSI of MPEG-4 LASeR standard to provide users a widget-like rich media application. This application utilizes MPEG-4 LASeR with PMSI technique as PI, and this PI references SI to present information that resides in SI on a scene. In this paper, we provide descriptions of technical ingredients used to build the presented application. The framework is presented followed by the implementation result. Possible impacts and applicable services are described in the conclusion.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.47 no.12
• /
• pp.874-880
• /
• 2019

This paper introduces a method which can be effectively used for the path planning of UAV in a realistic map which has mountainous terrains, air defense networks and radars based on the Visibility Graph. Existing studies of Visibility Graph have been studied mainly for simple shape obstacles in 2-dimensional environment such as self-driving cars which avoid buildings. However, for UAV, Visibility Graph must be used in 3-dimensional environment for the variance of altitude. This occurs significant elapsed time increase because of the increase of the amount of the visibility of node sets. To solve this problem, this paper decrease the number of nodes which consists the complex terrain environments using convex hull based on Layered Visibility Graph. With convex hull method, this paper confirmed that the elapsed time is decreased about 99.5% compared to the case which has no decrease of the number of nodes.

• Journal of The Korean Association For Science Education
• /
• v.22 no.3
• /
• pp.466-477
• /
• 2002

It was proposed that proper problem solving practice should improve students' questioning in physics. In the previous researches, improvement in students' questioning was observed after practice of making questions given the examples of desirable questions. In this study, the problem solving strategies used by experts were introduced to students in the form of step-by-step guide to follow in problem solving practice. The directions in the guide were concrete and operational for students to understand the expected behaviors explicitly. It was assumed that students could pinpoint the difficulty specifically through this guide, which would result in positive effects on students' recognition and expression of their own questions. The subjects in this study were college freshmen enrolled in the introductory physics for science or engineering major. The physics problems from the textbook were solved and practiced in the traditional way for controlled group. Worksheets designed to follow experts' problem solving strategies were used for the experimental group. Two groups were taught in the same way during lecture part of the class. Students were asked to describe the difficulties they had during homeworks or tests. Questions in this study means these descriptions written by students although they were not necessarily in the form of interrogative sentences. The questions were analyzed both in quantity and quality. Quantitatively, more students spontaneously turned in their questions in the experimental group than in the controlled group. Regarding the quality, there were more students in the experimental group than in the controlled group who described their difficulties in detail or recognized the need for the procedural knowledge.

• Journal of The Korean Association For Science Education
• /
• v.36 no.4
• /
• pp.617-628
• /
• 2016

This study aims to explore pre-service biology teachers' value orientation in terms of scientific observation and representation in plant cell microscope observation experiment. This study focuses on the pre-service teachers' value orientation in relation to objectivity. To achieve this aim, we used a hypothetical situation that pre-service teachers should teach tacit knowledge related to observation and representation during the cell observation class. We presented a hypothetical situation to fifty pre-service biology teachers and collected their answer about that hypothetical situation. These answers were categorized inductively based on constant comparative analysis. The result shows that four types of pre-service teachers' value orientation, 'presence confirmation', 'mechanical objectivity', 'students' subjectivity', and 'trained judgement', are confirmed. This result also shows that various value orientation could be reflected on teaching an experiment and tacit knowledge related to the experiment. Also, many pre-service teachers value 'mechanical objectivity' in observation and image representation. Also, pre-service teachers' value orientation and perception of objectivity in scientific practice could have an influence in teaching science, this result could give provide suggestions on science teachers' education in terms of scientific practice.

• Sijohaknonchong
• /
• v.30
• /
• pp.147-164
• /
• 2009

The conclusion of this paper is as follows. First, the authentic syllable count of sijo can be summed up as following: Second, the structure of the statement can be summed up as following: 1) Each statement extremely excludes the use of modifiers to clarify the development of the logic. 2) The meaning of each of the three statement, chojang (the 1st statement), jungjang (the middle statement) and jongjang (the last statement), is connected to the previous one closely, so the text as a whole is perfect. 3) The last statement identifies itself as the conversion or conclusion of the whole text. Therefore, the last statement should begin with a connective adverb like 'Therefore' or 'Then'. But in ancient sijo works, this sort of connected adverb is normally omitted. 4) Each statement of sijo is composed of one of the 4 structures suggested below: a) subjective phrase + predicative phrase b) the formal clause + the latter clause c) location-indicating phrase + sentence d) objective phrase + predicative phrase Since the text of a sijo work is formed like this, sijo is said to be composed of three jang (statement) & six gu (phrase), which is the very feature that proves that sijo is a fixed form of verse.

• The Journal of the Korea Contents Association
• /
• v.12 no.6
• /
• pp.151-159
• /
• 2012

The purpose of this thesis is to figure out the mechanism that how can be shown the aesthetic distances of novel in the film. At discussion of the view point, novel can be told by two factors which are 'who is teller' and 'who is watcher' but in the film, novel's narration is divided into visual point and auditive point. And I will consider the phenomenon on the part of this difference. Next, I will argue about difference between novel and film from the Park Jongwon's aesthetic distances which interpreted Lee Munyeol's work. This thesis is going to observe that how the film adapted three types of view point and how that related the subject of the original novel. For this thesis, I tried to track 'the distances' between figure and identity, and reader and author. Also I did approach that how can be accepted the problem of 'aesthetic distance according to identity' based on this novel in the film and novel's text by reader. This study make a proposal or analysis to the differences between novels and films in terms of narrative point of view. Although it is shown by dividing into each chapter in novel and on connectivity in film, this paper finds out that both film and novel are shown the subject of reader's difference of the view point about 'author and director's identity'.

• Journal of Digital Convergence
• /
• v.15 no.12
• /
• pp.581-590
• /
• 2017

This study was conducted to investigate the perception of nurse's use of physical restraints. This study is a descriptive research study for 138 nurses who work at the small hospitals under 300 beds. Statistical analysis was performed using descriptive statistics, t-test, ANOVA, and factor analysis using the SPSS statistical program. The results of this study were as follows: The overall average of the nurses' perception of physical restraint was $3.91{\pm}0.54$, and the most important reason for using a physical restraint was to protect the patient from falling out of bed($4.37{\pm}0.68$). The factor analysis showed that 'behavior, psychological symptom management($3.81{\pm}0.67$)', 'maintain medical treatment($4.11{\pm}0.60$)' and 'patient safety($4.13{\pm}0.63$)'. It is necessary to understand the characteristics and factors of nurse's use of physical restraint in small and medium hospitals. Moreover, it is also required to use minimum physical restraints for patient's safeties and rights based on accurate understanding of physical restraint's use. Therefore, it is needed to provide job training for the physical restraint that is used in various situations and to develop education and intervention program to adjust in nurses' situation.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.46 no.2
• /
• pp.89-98
• /
• 2009

In the field of computer vision, image mosaicking is a common method for effectively increasing restricted the field of view of a camera by combining a set of separate images into a single seamless image. Image mosaicking based on feature points has recently been a focus of research because of simple estimation for geometric transformation regardless distortions and differences of intensity generating by motion of a camera in consecutive images. Yet, since most feature-point matching algorithms extract feature points using gray values, identifying corresponding points becomes difficult in the case of changing illumination and images with a similar intensity. Accordingly, to solve these problems, this paper proposes a method of image mosaicking based on feature points using color information of images. Essentially, the digital values acquired from a digital color camera are converted to values of a virtual camera with distinct narrow bands. Values based on the surface reflectance and invariant to the chromaticity of various illuminations are then derived from the virtual camera values and defined as color-invariant values invariant to changing illuminations. The validity of these color-invariant values is verified in a test using a Macbeth Color-Checker under simulated illuminations. The test also compares the proposed method using the color-invariant values with the conventional SIFT algorithm. The accuracy of the matching between the feature points extracted using the proposed method is increased, while image mosaicking using color information is also achieved.

• Journal of The Korean Association For Science Education
• /
• v.18 no.4
• /
• pp.517-523
• /
• 1998

It has been an important task that the decreased quantities of science lessons must blend with the 7th science curriculum. This study analysed the 6th and 7th science curriculum contents, and found the perspective and the problems in relation to the decreased lessons in the 7th science curriculum. The results found in the analysis of the science content system in the curriculum are as follows: first, the new science themes in the 7th content system were those appeared in the sub-themes in the 6th curriculum, so substantially scientific concepts didn't increase in the 7th. Second, the number of the terms which restricts the conceptual and contextual region of the major science themes considerably increased in the 7th curriculum. Third, Surface Lesson Quantities(SLQ), which were defined as the counted lesson number considering the quantities of science themes and the lesson decreasing rate 30% of the whole school curriculum, were inferred as 38.5% of the 6th lesson quantities. And the results found in the analysis of the sub-themes inferred from the sentences describing the science themes in each grade are as follows: Essential Lesson Quantities (ELQ), which were defined based on the sub-themes, were more than SLQ in almost themes. But, in case of the themes, 'weather' and 'ground', SLQ were much more than ELQ. The results of this study shows that it will not easy to solve the task, the decreasing lessons and phenomena-centered approach in constructing the science teaching content according to the 7th science curriculum.