• Journal of Korea Multimedia Society
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• v.9 no.6
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• pp.742-749
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• 2006

In the network-based game where it uses the Internet infrastructure, the implementation is possible with the various methods. Such Applications are developed in the multi-tired architecture. There are many cases for the server to be separated from the hardware or the software. In this case, a lot of applications make the distributed process possible and are made as the multi-tiered architecture to develop the reusability of the existing software module. Especially, it is mostly general to separate for the case of a database server to a new tier. One of the important points of multi-tiered server side applications is security and because of this, it is difficult to share the related data about the design skill. Using design patterns, it gives help in reusing the existing written-code for the design of the game that needs a lot of money and time. Design Patterns are related to the software reuse. For the development of more efficient games, if well-defined design patterns are provided to the developers, then it would make more easy advanced game API and make possible the framework for the game development based on the API Through the analysis of the general network-based game currently servicing in the Internet, in this paper, we discuss how to implement a business logic tier using database system among the server side architectures. The main objective of this article is to show an efficient APIs(Application Programming Interfaces) design method which can be used to manage the data that must be saved to the database system among the packets that client/server have to be exchange.

• Journal of KIISE:Software and Applications
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• v.26 no.10
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• pp.1237-1246
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• 1999

최근 모든 분야에서 외국과의 교류가 증대됨에 따라서 한국어 문서에는 점점 더 많은 외국어 음차 표기가 사용되는 경향이 있다. 하지만 같은 외국어에 대한 음차 표기에 개인차가 심하여 이들 음차 표기를 포함한 문서들에 대한 검색을 어렵게 만드는 원인이 되고 있다. 한 가지 해결 방법은 색인 시에 같은 외국어에서 온 음차 표기들을 등가부류로 묶어서 색인해 놓았다가 질의 시에 확장하는 방법이다. 본 논문에서는 외국어 음차 표기들의 등가부류를 만드는데 필요한 음차 표기의 음성적 유사도 비교 알고리즘인 Kodex를 제안한다. Kodex 방법은 기존의 스트링 비교 방법인 비음성적 방법에 비해 음차 표기들을 등가부류로 클러스터링하는데 있어 더 나은 성능을 보이면서도, 계산이 간단하여 훨씬 효율적으로 구현될 수 있는 장점이 있다.Abstract With the advent of digital communication technologies, as Koreans communicate with foreigners more frequently, more foreign word transliterations are being used in Korean documents more than ever before. The transliterations of foreign words are very various among individuals. This makes text retrieval tasks about these documents very difficult. In this paper we propose a new method, called Kodex, of measuring the phonetic similarity among foreign word transliterations. Kodex can be used to generate the equivalence classes of the transliterations while indexing and conflate the equivalent transliterations at the querying stage. We show that Kodex gives higher precision at the similar recall level and is more efficient in computation than non-phonetic methods based on string similarity measure.

• Journal of the Korean Society of Radiology
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• v.5 no.1
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• pp.19-25
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• 2011

Photoplethysmogram(PPG) is the method to obtain the biomedical signal using the linear relationships between the blood volume for changing the cardiac contraction and relaxation and the amount of light for absorbing the hemoglobin in the blood. In this paper, we proposed the analyzed results which show the heart rate variability and the distribution of heart rate for before and after using PPG. Moreover, this paper designed and implemented the system based on personal computer to predict cardiovascular disease in advance using the analyzed results for the autonomic balance from taking the spectral analysis of heart rate and the state of the blood vessel for analyzing APG(acceleration plethysmogram).

• Journal of Digital Convergence
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• v.14 no.11
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• pp.501-505
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• 2016

Recently, the frequency of dealing important information regarding financial services like paying through smart device or internet banking on smart device has been increasing. Also, with the development of smart device execution environment towards open software environment, it became easier for users to download and use random application software, and its security aspect appears to be weakening. This study inspects features of hardware-based smart device security technology. Furthermore, this study proposes a realization method in MTM hardware-based secure smart device execution environment for an application software that runs in smart devices. While existing MTM provides the root of trust function only for the mobile device, the MTM-based mobile security environment technology proposed in this paper can provide numerous security functions that application program needs in mobile device. The further researches on IoT devices that are compatible with security hardware, gateway security technology and methods that secure reliability and security applicable to varied IoT devices by advancing security hardware are the next plan to proceed.

• Journal of Digital Convergence
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• v.13 no.7
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• pp.183-196
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• 2015

In order to perform a successful outsourcing, we needs the SLA through improving the quality of IT services. In particular SLA metrics and evaluation criteria is an important factor as to substitute the IT viability of the company to promote IT Outsourcing. SLA metrics consist of technical, managerial, user perspective items, and has been managed to aim to provide reliable and continuous quality improvement of IT services. This study focuses on the HW availability metrics of SLA indicators of IT outsourcing. We propose the Infra availability criteria for the HW configuration level to meet the SLA contract and evaluation. We offer the Infra configuration standards of SLA contract, and propose criteria to determine the suitability of the target levels in IT operations audit environment. The proposed model was verified the necessity and effectiveness of the Infra configuration standards and operation audit check items through the surveys of experts and users.

• Journal of KIISE:Software and Applications
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• v.28 no.9
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• pp.603-611
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• 2001

This paper proposes a novel fast layer-by-layer algorithm that has better generalization capability. In the proposed algorithm, the weights of the hidden layer are updated by the target vector of the hidden layer obtained by least squares method. The proposed algorithm improves the learning speed that can occur due to the small magnitude of the gradient vector in the hidden layer. This algorithm was tested in a handwritten digits recognition problem. The learning speed of the proposed algorithm was faster than those of error back propagation algorithm and modified error function algorithm, and similar to those of Ooyen's method and layer-by-layer algorithm. Moreover, the simulation results showed that the proposed algorithm had the best generalization capability among them regardless of the number of hidden nodes. The proposed algorithm has the advantages of the learning speed of layer-by-layer algorithm and the generalization capability of error back propagation algorithm and modified error function algorithm.

• Journal of KIISE:Software and Applications
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• v.26 no.12
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• pp.1428-1444
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• 1999

MSC는 ITU에 의해 표준화된, 병행 시스템의 명세를 기술하기 위한 그래픽 형태와 텍스트 형태를 제공하는 언어로서 실시간 시스템 특히 통신 교환 시스템의 특성을 기술하기 위해 자주 사용된다. 통신 시스템이 제대로 동작함을 보이기 위해서는 정형적인 방법을 사용하여 시스템 행위를 검증할 필요가 있다. 통신 소프트웨어를 검증하는 방법 중 하나의 방법으로 유한 상태를 기반으로 하는 방법이 있다. 유한 상태를 기반으로 하는 방법에서는 먼저 시스템 명세에 해당하는 전체 상태 전이 그래프를 생성한 후 이를 바탕으로 model-checking 등의 방법을 사용하여 시스템의 특성을 검증한다. 본 논문에서는 MSC로 기술된 통신 소프트웨어 명세로부터 전체 상태 전이 그래프를 생성하는 방법에 초점을 맞추었다. 시스템 명세에 해당하는 상태 전이 그래프를 생성하기 위해 보다 직관적으로 MSC의 의미론을 표현할 수 있고, 또한 쉽게 전체 상태 전이 그래프를 생성할 수 있는 행위 종속 그래프를 제안하였다. MSC 명세는 일단 행위 종속 그래프로 변환이 되고 이 행위 종속 그래프를 이용하여 전체 상태 전이 그래프가 생성된다.Abstract Message Sequence Chart (MSC) standardized by International Telecommunication Union is a graphical and textual language for describing the specification of concurrent systems. It is frequently used both formally and informally for specifying the behavior of real-time systems, in particular telecommunication switching systems. To ensure that a communication system operates properly, the verification process showing the correctness of system's behavior formally is necessary. One of the verification methods is a finite-state method. In the finite-state method, the global state transition graph (GSTG) is constructed and then safety and liveness properties of systems are verified through a well-known method such as model checking. In this paper, we forcus on the construction of GSTG from the specifications of telecommunication software written in MSC. We suggest Action Dependency Graph (ADG) which can present the semantics of MSC intuitively and also provide a GSTG construction method from ADG. MSC specifications are translated to ADGs and, in turns, the GSTGs are constructed by using these ADGs.

• ETRI Journal
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• v.24 no.3
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• pp.211-220
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• 2002

This study characterizes an oxide etching process in a magnetically enhanced reactive ion etching (MERIE) reactor with a $CHF_3/CF_4$ gas chemistry. We use a statistical $2^{4-1}$ experimental design plus one center point to characterize the relationships between the process factors and etch responses. The factors that we varied in the design include RF power, pressure, and gas composition, and the modeled etch responses were the etch rate, etch selectivity to TiN, and uniformity. The developed models produced 3D response plots. Etching of $SiO_2$ mainly depends on F density and ion bombardment. $SiO_2$ etch selectivity to TiN sensitively depends on the F density in the plasma and the effects of ion bombardment. The process conditions for a high etch selectivity are a 0.3 to 0.5 $CF_4$ flow ratio and a -600 V to -650 V DC bias voltage according to the process pressure in our experiment. Etching uniformity was improved with an increase in the $CF_4$ flow ratio in the gas mixture, an increase in the source power, and a higher pressure. Our characterization of via etching in a $CHF_3/CF_4$ MERIE using neural networks was successful, economical, and effective. The results provide highly valuable information about etching mechanisms and optimum etching conditions.

• ETRI Journal
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• v.31 no.6
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• pp.667-674
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• 2009

Terahertz time-domain spectroscopy has been used to study the optical and dielectric properties of three chalcogenide glasses: $Ge_{30}As_8Ga_2Se_{60}$, $Ge_{35}Ga_5Se_{60}$, and $Ge_{10}As_{20}S_{70}$. The absorption coefficients ${\alpha}({\nu})$, complex refractive index n(${\nu}$), and complex dielectric constants ${\varepsilon}({\nu})$ were measured in a frequency range from 0.3 THz to 1.5 THz. The measured real refractive indices were fitted using a Sellmeier equation. The results show that the Sellmeier equation fits well with the data throughout the frequency range and imply that the phonon modes of glasses vary with the glass compositions. The theory of far-infrared absorption in amorphous materials is used to analyze the results and to understand the differences in THz absorption among the sample glasses.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.4
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• pp.1-8
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• 2000

A defect of decrease in TCP throughput can be investigated in asymmetric environment of different uplink and downlink bandwidths. Under two-way TCP traffic, the total link utilization is decreased by the successive injection of data packets in buffer. To solve these problems, terminal ACK filtering and packet scheduling mechanisms are introduced in this paper. ACK filtering eliminates the buffered ACK packets and transmits recent ACK packets in the uplink with limited bandwidth. Packet scheduling is the method of preventing 'clustering' and 'ack compression' states which are generated in the two-way TCP traffic. The guarantee of the data traffic in reverse TCP connection and the high throughput in forward TCP connection are investigated by simulation.