• 한국멀티미디어학회논문지
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• 제17권10호
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• pp.1182-1188
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• 2014

Recently, the research on database outsourcing has been actively done with the popularity of cloud computing. However, because users' data may contain sensitive personal information, such as health, financial and location information, the data encryption methods have attracted much interest. Existing data encryption schemes process a query without decrypting the encrypted databases in order to support user privacy protection. On the other hand, to efficiently handle the large amount of data in cloud computing, it is necessary to study the distributed index structure. However, existing index structure and query processing algorithms have a limitation that they only consider single-column query processing. In this paper, we propose a grid-based multi column indexing scheme and an encrypted query processing algorithm. In order to support multi-column query processing, the multi-dimensional index keys are generated by using a space decomposition method, i.e. grid index. To support encrypted query processing over encrypted data, we adopt the Hilbert curve when generating a index key. Finally, we prove that the proposed scheme is more efficient than existing scheme for processing the exact and range query.

• 한국문헌정보학회지
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• 제57권2호
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• pp.409-434
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• 2023

이 연구에서는 국내 문헌정보학 분야 4개 학회 학술지에 2002년부터 2021년까지 20년 동안 게재된 논문 전체의 저자를 분석하여 국내 문헌정보학 학술지를 통한 학술 커뮤니케이션 현황을 고찰하고 향후 전망을 제시하는 것을 목표로 한다. 이를 위해서 학술지별 공저자 수, 귀환저자 비율, 투고선호지수, 저자집단 변화 추세, 연구자 유인지수 등을 분석하였다. 분석 결과 4개 학술지의 공동연구 수준, 학술지별로 연관된 저자집단의 형성 정도, 저자집단이 변화된 변곡점, 신진 연구자 집단의 특성, 학술지 간 저자 공유 정도 등이 파악되었다. 전체적으로 2015년이 한국 문헌정보학 저자집단이 변화한 변곡점으로 나타났으며, 이후에 등장한 신진 연구자들은 주로 공동연구를 수행하면서 이전과 다소 다른 학술지 논문발표 행태를 보였다. 계량분석을 수행한 이 연구의 결과가 질적 연구방법을 사용한 선행 연구와 함께 활용된다면 한국 문헌정보학 학술지 발전 전략에 대한 다각화 연구를 수행한 효과를 거둘 것으로 기대된다.

• 한국수자원학회논문집
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• 제36권6호
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• pp.961-969
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• 2003

토양수분 분포의 시공간적인 예측을 위하여 유사 동력학 상태의 습윤지수 계산과정을 정리하였고, 우량 자료를 회귀적분한 동력학적 습윤지수의 계산 알고리즘을 개발하였다. 설마천 유역의 수치고도 모형과 2년간의 우량자료를 활용하여 동력학적 상태의 습윤지수의 시ㆍ공간적인 거동을 분석하였다. 공간적인 거동은 동력학적인 습윤지수가 유사 동력학적 상태나 정적인 습윤지수와 비교하여 흐름분산 특성이 강조된 분포특성을 보여주었다. 통계적인 특성으로는 시간이 경과함에 따라 유사동력학적 습윤지수나 동력학적 습윤지수 모두 정상상태 습윤지수에 근접하나, 동력학적 습윤지수의 경우 두 개의 상이한 분포특성이 나타났다.

• 한국정보시스템학회지:정보시스템연구
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• 제23권1호
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• pp.161-184
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• 2014

Our study measures the Digital Life Index (DLI) of baby boomers by considering the utilization of digital devices in their everyday life. The study was conducted by implementing the following three-step approach: (1) development of survey questions and data collection; (2) build Digital Life Index (DLI) model and lastly; (3) empirical analysis using the Digital Life Index (DLI). In the first stage in order to develop the survey questions to measure the digital index, two surveys were conducted. For the first preliminary survey, it was done based on the existing literatures which enabled this investigation through FGI analysis involving real professionals. The second survey was conducted by commissioning a specialized external firm. In this survey, a total of 400 data was collected to verify the validity and objectivity of the data sample. The data gathered through the survey questions was used to develop the digital index. Firstly, the appropriate factors were extracted by conducting factor analysis. This factor analysis validates and verifies the factors which are appropriate in measuring Digital Life Index (DLI). The derived factors are broadly divided into five main factors. The first factor describes the possession, purchase and use of digital device (x1). Meanwhile, the second factor describes the digital device's software (x2) and the third factor describes the participation in utilizing digital device (x3). The fourth factor describes the utilization of digital device in human personal relationship (x4) and lastly, the fifth factor describes the effect of digital device in everyday life and work environment (x5). Secondly, the digital index model was developed. The variables to represent the Digital Life Index (DLI) are ${\chi}1t,{\chi}2t,{\chi}3t,{\chi}4t$ and ${\chi}5t$. Furthermore, as experience in using the digital index grows overtime, the growth can be represented by the "S" shape. Based on the results, Digital Life Index(DLI) is distributed with the highest point at 90.3 and the lowest point at 25.9.

• 대한음성학회지:말소리
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• 제53호
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• pp.75-92
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• 2005

Prosody Generation Based on C-ToBI Representation for Text-to-SpeechSeungwon Kim, Yu Zheng, Gary Geunbae Lee, Byeongchang KimProsody modeling is critical in developing text-to-speech (TTS) systems where speech synthesis is used to automatically generate natural speech. In this paper, we present a prosody generation architecture based on Chinese Tone and Break Index (C-ToBI) representation. ToBI is a multi-tier representation system based on linguistic knowledge to transcribe events in an utterance. The TTS system which adopts ToBI as an intermediate representation is known to exhibit higher flexibility, modularity and domain/task portability compared with the direct prosody generation TTS systems. However, the cost of corpus preparation is very expensive for practical-level performance because the ToBI labeled corpus has been manually constructed by many prosody experts and normally requires a large amount of data for accurate statistical prosody modeling. This paper proposes a new method which transcribes the C-ToBI labels automatically in Chinese speech. We model Chinese prosody generation as a classification problem and apply conditional Maximum Entropy (ME) classification to this problem. We empirically verify the usefulness of various natural language and phonology features to make well-integrated features for ME framework.

• Journal of the Korean Physical Society
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• 제73권9호
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• pp.1303-1309
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• 2018

In the present paper, we study the entropy analysis of boundary layer flow over a slender stretching sheet under the action of a non uniform magnetic field that is acting perpendicular to the flow direction. The effects of viscous dissipation and Joule heating are included in the energy equation. Using similarity transformation technique the momentum and thermal boundary layer equations to a system of nonlinear differential equations. Numerical solutions are obtained using the shooting and fourth-order Runge-Kutta method. The expressions for the entropy generation number and Bejan number are also obtained using a suggested similarity transformation. The main objective of this article is to investigate the effects of different governing parameters such as the magnetic parameter ($M^2$), Prandtl number (Pr), Eckert number (Ec), velocity index parameter (m), wall thickness parameter (${\alpha}$), temperature difference parameter (${\Omega}$), entropy generation number (Ns) and Bejan number (Be). All these effects are portrayed graphically and discussed in detail. The analysis reveals that entropy generation reduces with decreasing wall thickness parameter and increasing temperature difference between the stretching sheet and the fluid outside the boundary layer. The viscous and magnetic irreversibilities are dominant in the vicinity of the stretching surface.

• Journal of Electrical Engineering and Technology
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• 제11권6호
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• pp.1590-1599
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• 2016

The installation of distributed generation (DG) in the electrical networks has numerous advantages. However, connecting and disconnecting of DGs (CADD) leads to some problems in coordination of protection devices due to the changes in the short circuit levels in the different points of network. In this paper, an adaptive method is proposed based on available setting groups (SG) of relays. Since the number of available SG is less than possible CADD states, a classifying index (CI) is defined to categorize the several states in restricted setting groups. Genetic algorithm (GA) with a suitable objective function (OF) is used as an optimization method for the classification. After grouping, a modified coordination method is applied to achieve optimal coordination for each group. The efficiency of the proposed technique is demonstrated by simulation results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.828-830
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• 2005

A index using generation cost for planning' for representing economical efficiency of generator, However in case of Combined heat and power(CHP) the product is divided in electrical power and steam, so there are no unconditional comparison between general generator and CHP. To calculating the generation cost for planning of CHP, this study using the method that change electrical power and steam into same unit and suggest the comparing system that can compare economical efficiency with other generators.

• 로봇학회논문지
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• 제2권2호
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• pp.191-195
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• 2007

Abstract MOCIE(Ministry of Commerce, Industry and Energy) handles 6 Projects for Intelligent Robot, whose budget is around 40 Million dollars per year. In this paper we have tried to analyze the state of robot technology of the projects. Each sub-projects has been divided according to the technological classification. Two major projects of Next Generation Growth Engine and 21C Frontier show different state each other. The former is focused on the product while the latter on the technology. Output of 21C Frontier should be linked to the Next Generation Growth Engine, otherwise, it will fail to advance. The project management handles only the quantitative performance such as business results, number of prototype, and number of patents and papers. Technological Capability is essential and it should be managed. This paper proposes efficient classification of robot technology and technology index.

• 한국군사과학기술학회지
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• 제15권5호
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• pp.643-650
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• 2012

This paper presents quantitative method of static combat effectiveness to classify fighter aircraft generations. We have analyzed performance metrics of United States(US), United Kingdom(UK), Russia, France, Sweden' fighters to determine jet-fighter generation. Both nominal and continuous variables were defined and used to present current trend of combat effectiveness.