• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.26 no.4
• /
• pp.895-902
• /
• 2016

Smart phone distribution rate has been rising and it's security threat also has been rising. Especially Android smart phone reaches nearly 85% of domestic share. Since repackaging on android smart phone is relatively easy, the number of re-packaged malwares has shown steady increase. While many detection techniques have been proposed in order to prevent malwares, it is not easy to detect re-packaged malwares by static analysis and it is also difficult to operate dynamic analysis in android smart phone. Static analysis proposed in this paper features code reuse of repackaged malwares. We extracted DEX files from android applications and performed static analysis using class names and method names. This process doesn't not include reverse engineering, so it is possible to detect malwares efficiently.

• Proceedings of the Korea Database Society Conference
• /
• 1994.09a
• /
• pp.105-129
• /
• 1994

The information system of corporations are facing a new environment expressed by miniaturization, decentralization and Open System. It is therefore of utmost importance for corporations to adapt flexibly th such new environment by providing for corresponding changes to their existing information systems. The objectives of this study are to identify this new environment faced by today′s information system and develop effective methods for data resource management under this new environment. In this study, it is assumed that the new environment faced by information systems can be specified as Distributed Computing Environment, and in order to achieve such system, presents Client/server architecture as its representative computing structure, This study defines Client/server architecture as a computing architecture which specialize the fuctionality of the client system and the server system in order to have an application distribute and perform cooperative processing at the best platform. Furthermore, from among the five structures utilized in Client/server architecture for distribution and cooperative processing of application between server and client this study presents two different data management methods under the Client/server environment; one is "Remote Data Management Method" which uses file server or database server and. the other is "Distributed Data Management Method" using distributed database management system. The result of this study leads to the conclusion that in the client/server environment although distributed application is assumed, the data could become centralized (in the case of file server or database server) or decentralized (in the case of distributed database system) and the data management method through a distributed database system where complete responsibility and powers with respect to control of data used by the user are given not only is it more adaptable to modern flexible corporate environment, but in terms of system operation, it presents a more efficient data management alternative compared to existing data management methods in terms of cutting costs.

• Journal of the Korean Society of Radiology
• /
• v.13 no.7
• /
• pp.947-953
• /
• 2019

The purpose of this study was to manufacture a wrist brace using a computerized tomography system, clinical design software (MediACE 3D Program), and 3D printer. After acquiring the Dicom file of the upper limb with a computed tomography, the wrist brace was designed using the MediACE 3D Program to create a "stereolithography" file. The designed wrist brace was printed using a 3D printer. To verify the effectiveness of wrist assistive device manufactured by 3D printing technology, the stress distribution of the pressure and orthosis applied to bone and skin is represented by finite element analysis. It is expected that the wrist brace can be manufactured by reinforcing the part where the damage caused by pressure and breakage of the brace frequently occurs with the result of finite element analysis when producing the wrist brace.

• Progress in Medical Physics
• /
• v.30 no.4
• /
• pp.128-138
• /
• 2019

Purpose: Segmental analysis of volumetric modulated arc therapy (VMAT) is not clinically used for compositional error source evaluation. Instead, dose verification is routinely used for plan-specific quality assurance (QA). While this approach identifies the resultant error, it does not specify which machine parameter was responsible for the error. In this research study, we adopted an approach for the segmental analysis of VMAT as a part of machine QA of linear accelerator (LINAC). Methods: Two portal dose QA plans were generated for VMAT QA: a) for full arc and b) for the arc, which was segmented in 12 subsegments. We investigated the multileaf collimator (MLC) position and dosimetric accuracy in the full and segmented arc delivery schemes. A MATLAB program was used to calculate the MLC position error from the data in the dynalog file. The Gamma passing rate (GPR) and the measured to planned dose difference (DD) in each pixel of the electronic portal imaging device was the measurement for dosimetric accuracy. The eclipse treatment planning system and a MATLAB program were used to calculate the dosimetric accuracy. Results: The maximum root-mean-square error of the MLC positions were <1 mm. The GPR was within the range of 98%-99.7% and was similar in both types of VMAT delivery. In general, the DD was <5 calibration units in both full arcs. A similar DD distribution was found for continuous arc and segmented arcs sums. Exceedingly high DD were not observed in any of the arc segment delivery schemes. The LINAC performance was acceptable regarding the execution of the VMAT QA plan. Conclusions: The segmental analysis proposed in this study is expected to be useful for the prediction of the delivery of the VMAT in relation to the gantry angle. We thus recommend the use of segmental analysis of VMAT as part of the regular QA.

• KEPCO Journal on Electric Power and Energy
• /
• v.3 no.2
• /
• pp.89-97
• /
• 2017

The substation is a critical node in the power network where power is transformed in the power generation, transmission and distribution system. The IEC 61850 is a global standard which proposes efficient substation automation by defining interoperable communication and data modelling techniques. In order to achieve this level of interoperability and automation, the IEC 61850 (Part 6) defines System Configuration description Language (SCL). The SCL is an XML based file format for defining the abstract model of primary and secondary substation equipment, communications systems and also the relationship between them. It enables the interoperable exchange of data during substation engineering by standardizing the description of applications at different stages of the engineering process. To achieve the seamless interoperability, multi-vendor devices are required to adhere completely to the IEC 61850. This paper proposes an efficient algorithm required for verifying the interoperability of multi-vendor devices by checking the adherence of the SCL file to specifications of the standard. Our proposed SCL validation algorithm consists of schema validation and other functionalities including information model validation using UML data model, the Vendor Defined Extension model validation, the User Defined Rule validation and the IED Engineering Table (IET) consistency validation. It also integrates the standard UCAIUG (Utility Communication Architecture International Users Group) Procedure validation for quality assurance testing. Our proposed algorithm is not only flexible and efficient in terms of ensuring interoperable functionality of tested devices, it is also convenient for use by system integrators and test engineers.

• KIPS Transactions on Computer and Communication Systems
• /
• v.3 no.8
• /
• pp.245-250
• /
• 2014

In recent years, the developments of medical technology and emergency medical services have been changed to home from the hospital. In this regard, the researches for the prevention or early diagnosis have become actively. In particular, bio-signal monitoring is applied to a variety of u-healthcare application services. The proposed system in this paper is to provide a security technology to protect the medical information measured from the various sensors. Especially, bio-signal information is privacy-sensitive personal information that must be protected. We applied a two-dimensional code technology, QR code, for the protection and management. In the client side, it can analyze the QR code and confirm the results on devices. Finally, with this proposed platform, we show the results of application service to verify the creation and distribution of integrated image file between the bio-signal and medical image information.

• The Journal of Advanced Prosthodontics
• /
• v.14 no.1
• /
• pp.45-55
• /
• 2022

PURPOSE. This in vitro study investigates the effect of different post-rinsing times and methods on the trueness and precision of denture base resin manufactured through stereolithography. MATERIALS AND METHODS. Ninety clear photopolymer resin specimens were fabricated and divided into nine groups (n = 10) based on rinsing times and methods. All specimens were rinsed with 99% isopropanol alcohol for 5, 10, and 15 min using three methods-automated, ultrasonic cleaning, and hand washing. The specimens were polymerized for 30 min at 40℃. For trueness, the scanned intaglio surface of each SLA denture base was superimposed on the original standard tessellation language (STL) file using best-fit alignment (n = 10). For precision, the scanned intaglio surface of the STL file in each specimen group was superimposed across each specimen (n = 45). The root mean square error (RMSE) was measured, and the data were analyzed statistically through one-way ANOVA and Tukey test (α < .05). RESULTS. The 10-min automated group exhibited the lowest RMSE. For trueness, this was significantly different from specimens in the 5-min hand-washed group (P < .05). For precision, this was significantly different from those of other groups (P < .05), except for the 15-min automated and 15-min ultrasonic groups. The color map results indicated that the 10-min automated method exhibited the most uniform distribution of the intaglio surface adaptation. CONCLUSION. The optimal postprocessing rinsing times and methods for achieving clear photopolymer resin were found to be the automated method with rinsing times of 10 and 15 min, and the ultrasonic method with a rinsing time of 15 min.

• Tribology and Lubricants
• /
• v.3 no.1
• /
• pp.18-25
• /
• 1987

The influence of one sided striated surface roughness on load carrying capacity of a slider bearing is analyzed for very low clearance films. A Reynolds equation appropriate for slider bearing is derived and analyzed by the method of finite difference method. For a slider bearing with several simple roughness form, the pressure, load capacity and other parameters can be revealed and also this results can be stored in sequential data file. After all, their distribution can be displayed easily by using the CADG(Computer Aided Design and Graphics) program. Also exact solutions with this nemerical method are compared with those of the theory attributed to Tonder and White. The results reported here should find application in the computer peripherals where computer aided design and graphic package is needed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.29 no.6
• /
• pp.1-7
• /
• 2015

Road lighting is designed with a goal of achieving the related standards on luminance, uniformity ratio and glare. Unless the luminaire with LID which is perfect for road conditions is used, a situation which fails to meet lighting standards may occur. The study examined the relationship of maximum spacing with average road luminance and longitudinal uniformity. Based on the result of the analysis, this study evaluated luminaire with what characteristics are suitable to achieve lighting requirements of the roads and suggested methods of selection for luminaires depending on the size of the road.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2008.02a
• /
• pp.13-16
• /
• 2008

패치 분배 시스템은 중앙 집중 방식의 구조를 가지고 있다. 이런 중앙 집중 방식의 구조는 많은 사용자가 존재할 경우 영향력이 서버에 집중된다. 따라서 한 노드로 미치는 영향을 최소화하기 위해서 본 논문에서는 P2P 통신 구조의 유연함과 분산적인 성격을 이용한 패치 분배 시스템 구조를 제시한다. 또한 패치 파일이 정상적으로 안전하게 전송 하도록 P2P 프레임 워크를 제안 한다. 이 프레임 워크는 파일에 대한 내용변조에 민감하게 반응 하도록 설계 되었다. 그러므로 우리는 웜, 바이러스, 그리고 해킹에 입구가 되는 취약점을 없애기 위한 패치 파일을 빠른 속도로 네트워크의 구성원에 전파 할 수 있게 된다.