• Journal of Korean Society for Geospatial Information Science
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• v.17 no.1
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• pp.167-174
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• 2009

A Tile Map Service is a regular map service that has been enhanced to serve maps very quickly using a cache of static images. The map cache is a directory that contains image tiles of a map extent at specific scale levels. Returning a tile from the cache takes the server much less time than drawing the map image on demand. Use of a Tile Map Service can dramatically improve the time that clients take to display complex base-maps. Using Tile Map Services thus eliminate the need to trade quality for performance. This study provides a way to construct Tile Map Service System using Open Source GIS. We used GDAL(Geospatial Data Abstraction Library) which is one of the Open Source GIS Softwares to make Tile Map Image and OpenLayers to publish Web Page. Moreover, We conducted a performance test on Tile Map System and Dynamic Map System and evaluated the results of it. As a result, the proposed method makes it easier to construct high performance Tile Map Service using Open Source GIS without commercial products.

• Korean Journal of Optics and Photonics
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• v.8 no.6
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• pp.486-491
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• 1997

A division-of-amplitude type photopolarimeter has been constructed for the analysis of the dynamic optical characteristics of liquid crystal panels, one of the essential components of liquid crystal displays. In this instrument an incoming light ray, whose state of polarization is to be determined, is divided into three rays of nearly same intensities and of identical polarization state by using NPBS'(non-polarizing beam splitters). Each of the three rays is further divided into two components of orthogonal polarization states by using a PBS(polarizing cube beamsplitter) or by using a combination of a quater wave plate followed by a PBS. The intensity of each ray is measured by using a photodiode to produce a set of six photo-signals, which in turn are converted into four Stokes parameters describing the state of polarization of the incoming ray. Performance test of the insrument shows that its time resolution is 80 $mutextrm{s}$, accuracy $\pm$0.3 degrees when the state of polarization of the incoming ray is representated on the Poincare sphere.

• Progress in Medical Physics
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• v.23 no.4
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• pp.239-251
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• 2012

In this paper, web-base image processing system has been implemented for remote-controlled medical robot applications. The developed software system was hierarchically composed of diverse image processing and remote operation modules, and the hierarchical composition was satisfied the expandability to higher level application and the accessibility over the web. It can also support diverse file formats including DICOM, VRML, and CAD(STL) to display, transmit, store and share the processed images depending on application environment. Message-based data exchange, object-oriented module and open-source based software configuration will enable the dynamic combination associated with diverse remote medical application requirements.

• Journal of the Korea Society of Computer and Information
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• v.16 no.7
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• pp.49-58
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• 2011

Augmented Reality(AR) assists human's cognitive ability through the information visualization by substantiating information about virtual situation. This technology is studied in a variety of ways including education, design, industry, and so on, by various supply of information devices equipped with cameras and display monitors. Since the most of the AR system depends on limited interaction that responds to the order from user, it can not reflect diverse real world situation. In this study, we suggest a knowledge based augmented reality system, which is composed of context awareness agent that provides recognized context information, along with knowledge based component that provides intelligent capability by utilizing domain knowledges. With this capability, the augmented object can generate dynamic model intelligently by reflecting context information, and can make the interaction possible among the multiple objects. We developed rule based context awareness system along with 3D model generation, and tested interaction among the augmented objects. And we suggest a framework that can provide a convenient way of developing augmented reality system for user.

• Journal of the Korea Society for Simulation
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• v.20 no.3
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• pp.1-10
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• 2011

In this study, we consider a capacity planning problem where the number of machines at each workstation is determined in manufacturing systems of top-edge electronic products such as semiconductor or display. The considered manufacturing system is the typical hybrid flowshop which has identical parallel machines at each workstation and the setup operation occurs when the types of consecutively processed products are different. The objective of the problem is finding good combinations of the numbers of machines at all workstations, under the given capital amount for purchasing machines. Various heuristic methods for determining the numbers of machines at workstations are proposed and the performances were tested through a series of computational experiments. In the study, a simulation model has been developed in order to simulate the considered manufacturing system with dynamic orders and complex process. The simulation model is also used for conducting the computational comparison test among various proposed methods.

• Journal of the Economic Geographical Society of Korea
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• v.4 no.1
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• pp.19-35
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• 2001

This paper is concerned with the relationships between large firms with global reaches in their markets and subcontracting firms, mostly small and medium-sized firms. It then attempts to focus in more detail on the dynamic relational dimensions between the two. In doing so, we draw upon the secondary data and the results of interviewing survey with some senior managers. The empirical study shows that the localisation of subcontracting networks have been increasingly reinforced thanks to the increasing tendency of vertical disintegration by LC. However, it is identified that there is a tendency that local subcontractors are specialised in producing relatively low value-added and low technology-intensive electronic parts/components. Based on these results, the author suggests the implications of regional economic development in the context of innovation and learning.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.3
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• pp.443-454
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• 2020

The JavaScript engine is a module that receives JavaScript code as input and processes it, among many functions that are loaded into web browsers and display web pages. Many fuzzing test studies have been conducted as vulnerabilities in JavaScript engines could threaten the system security of end-users running JavaScript through browsers. Some of them have increased fuzzing efficiency by guiding test coverage in JavaScript engines, but no coverage guided fuzzing of optimized, dynamically generated machine code was attempted. Optimized JavaScript codes are difficult to perform sufficient iterative testing through fuzzing due to the function of runtime guards to free the code in the event of exceptional control flow. To solve these problems, this paper proposes a method of performing fuzzing tests on optimized machine code by avoiding deoptimization. In addition, we propose a method to measure the coverage of runtime-guards by the dynamic binary instrumentation and to guide increment of runtime-guard coverage. In our experiment, our method has outperformed the existing method at two measures: runtime coverage and iteration by time.

• Journal of Korean Neurosurgical Society
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• v.29 no.3
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• pp.345-352
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• 2000

Objective : The purpose of this study was to compare computed tomographic angiography(CTA) with conventional cerebral angiography(CCA) and to assess usefulness of CTA in detection and anatomic definition of intracranial aneurysms of the circle of Willis in subarachnoid hemorrhage. Patients and Methods : Fifty consecutive patients with known or suspected intracranial saccular aneurysms underwent CTA with preoperative CCA from 1997 to 1999. Using surface shaded display post-processing technique, CTA was interpreted for the presence, location of aneurysms and anatomic features. The image obtained with CTA was then compared with CCA image. Results : In 47 patients, CCA revealed 57 cerebral aneurysms and CTA revealed 54 aneurysms. Two of the 57 cerebral aneurysms were located outside of the imaging volume of CTA and one case was misdiagnosed. The sensitivity of CTA was 94.7% and the specificity was 100%. The results obtained with CTA were, compared with the results obtained with CCA, equal in determining dome shape, direction and lobularity. However, CTA provided a 3-dimensional representation of aneurysmal lesion very useful for surgical planning. Moreover, CTA was useful for rapid and relatively noninvasive detection of aneurysms in the circle of Willis. Conclusion : CTA can be a diagnostic tool for the patients with acute subarachnoid hemorrhage due to a ruptured aneurysm of the circle of Willis and provides adequate anatomic detail for surgical planning, especially to complex cerebral aneurysms. However, we think CCA is necessary because of CTA limitations including its difficulty in detecting unusually located aneurysms(including those in cavernous sinus or distal artery) and combined vascular lesion (including arteriovenous malformation) and acquiring dynamic flow information.

• Physical Therapy Rehabilitation Science
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• v.3 no.1
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• pp.13-19
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• 2014

Objective: The purpose of this study was to determine the effects of Augmented Reality-based Postural Control (ARPC) training on balance and gait function in patients with stroke. Design: Single-blind randomized controlled trial. Methods: Twenty participants who experienced a stroke were enrolled in the study and randomly assigned to the ARPC (n=10) or control group (n=10). Subjects in both groups received conventional physical therapy for 60 min per session, 5 days per week, for 4 weeks. In addition, subjects in the ARPC group received ARPC training for 30 min per day, 3 days per week, for 4 weeks. The participants watched established normal postural control patterns on a head-mounted display and repeated the movements in ARPC training. Outcome measurements were assessed using the Berg Balance Scale (BBS) and 10-Meter Walk Test (10MWT) before and after 4 weeks of training. Results: Of the 20 randomized participants, only 18 completed the 4-week training program. The ARPC group showed significant improvement in the BBS and 10MWT after training (p<0.05). Meanwhile, the control group did not exhibit improvement in either variable. In addition, the ARPC group showed significantly greater improvement than the control group in the 10MWT (p<0.05), whereas no significant difference was observed between the groups for the BBS. Conclusions: The results of this study confirmed the benefits of ARPC training on dynamic balance and functional gait ability. Additionally, this study may provide evidence supporting the use of an ARPC training program for improving balance and gait ability in patients after a chronic stroke.

• Smart Structures and Systems
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• v.19 no.1
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• pp.1-10
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• 2017

The operation of subway trains induces secondary structure-borne vibrations in the nearby underground spaces. The vibration, along with the associated noise, can cause annoyance and adverse physical, physiological, and psychological effects on humans in dense urban environments. Traditional tethered instruments restrict the rapid measurement and assessment on such vibration effect. This paper presents a novel approach for Wireless Smart Sensor (WSS)-based autonomous evaluation system for the subway train-induced vibrations. The system was implemented on a MEMSIC's Imote2 platform, using a SHM-H high-sensitivity accelerometer board stacked on top. A new embedded application VibrationLevelCalculation, which determines the International Organization for Standardization defined weighted acceleration level, was added into the Illinois Structural Health Monitoring Project Service Toolsuite. The system was verified in a large underground space, where a nearby subway station is a good source of ground excitation caused by the running subway trains. Using an on-board processor, each sensor calculated the distribution of vibration levels within the testing zone, and sent the distribution of vibration level by radio to display it on the central server. Also, the raw time-histories and frequency spectrum were retrieved from the WSS leaf nodes. Subsequently, spectral vibration levels in the one-third octave band, characterizing the vibrating influence of different frequency components on human bodies, was also calculated from each sensor node. Experimental validation demonstrates that the proposed system is efficient for autonomously evaluating the subway train-induced ambient vibration of underground spaces, and the system holds the potential of greatly reducing the laboring of dynamic field testing.