• 한국통신학회논문지
• /
• 제41권8호
• /
• pp.965-973
• /
• 2016

IoT 서비스가 새로운 통신 서비스 분야로 조명 받으면서, 통신 단말의 수가 급격히 증가하고 있다. LTE-A 시스템 기반의 네트워크를 활용한다면, 해당 시스템의 증가하는 단말들의 수용 가능성에대한 분석이 필요하게 되었다. 기존 3GPP TR 37.868 문서의 성능 분석 결과는 단지 단말의 수가 30,000개까지 증가할 것에 대한 성능평가가 이루어졌으나, 미래의 이동통신 시스템에서는 더 많은 수의 단말에 대한 수용성이 필요하다. 본 논문에서는 5G 단말 수용의 요구사항인 셀 당 100,000개의 단말을 수용 가능한 시뮬레이터를 개발하여, 프리앰블 개수, 프리앰블 최대 전송 횟수, backoff indicator, msg2 window 사이즈 변화에 따른 랜덤 액세스의 영향을 분석한다. 이 시뮬레이터는 OPNET을 기반으로 개발되었으며, 기존 OPNET LTE 모듈의 단말 수용 한계를 극복하였다. 본 연구 결과를 기반으로, 5G 네트워크로의 전환 및 관련 표준화 활동 등에 활용 가능할 것으로 기대한다.

• 한국멀티미디어학회논문지
• /
• 제21권5호
• /
• pp.617-625
• /
• 2018

Phishing website has become a crucial concern in cyber security applications. It is performed by fraudulently deceiving users with the aim of obtaining their sensitive information such as bank account information, credit card, username, and password. The threat has led to huge losses to online retailers, e-business platform, financial institutions, and to name but a few. One way to build anti-phishing detection mechanism is to construct classification algorithm based on machine learning techniques. The objective of this paper is to compare different classifier ensemble approaches, i.e. random forest, rotation forest, gradient boosted machine, and extreme gradient boosting against single classifiers, i.e. decision tree, classification and regression tree, and credal decision tree in the case of website phishing. Area under ROC curve (AUC) is employed as a performance metric, whilst statistical tests are used as baseline indicator of significance evaluation among classifiers. The paper contributes the existing literature on making a benchmark of classifier ensembles for web phishing detection.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.1334-1338
• /
• 2005

A limit switch box is used for an indicator of a valve actuator. This device indicates an opening and closing of a valve or a throttle in the valve actuator. In a ship, equipments require safety and robustness because of a rough environment and a specific condition during a voyage. However, the limit switch box has been used in an indoor environment generally. This study developed a new limit switch box which can be used at an outdoor environment. This study designed the new limit switch box. The housing of the limit switch box was made by an aluminum die cast method with surface painting after anodizing or chromate coating. In order to evaluate the endurance of the housing, the endurance tests against salt water have been conducted. Experiment results showed that the proposed device provides a reliable performance against salt water.

• The Journal of the Acoustical Society of Korea
• /
• 제22권4E호
• /
• pp.161-166
• /
• 2003

We present an adaptive wavelet packet based speech enhancement method with robust voice activity detection (VAD) in non-stationary noise environment. The proposed method can be divided into two main procedures. The first procedure is a VAD with adaptive wavelet packet transform. And the other is a speech enhancement procedure based on the proposed VAD method. The proposed VAD method shows remarkable performance even in low SNRs and non-stationary noise environment. And subjective evaluation shows that the performance of the proposed speech enhancement method with wavelet bases is better than that with Fourier basis.

• Structural Engineering and Mechanics
• /
• 제44권4호
• /
• pp.417-429
• /
• 2012

Taking the superficial temperature increment as the major fatigue damage indicator, the infrared thermography was used to predict fatigue parameters (fatigue strength and S-N curve) of welded joints subjected to fatigue loading with a high mean stress, showing good predictions. The fatigue damage status, related to safety evaluation, was tightly correlated with the temperature field evolution of the hot-spot zone on the specimen surface. An energetic damage model, based on the energy accumulation, was developed to evaluate the residual fatigue life of the welded specimens undergoing cyclic loading, and a good agreement was presented. It is concluded that the infrared thermography can not only well predict the fatigue behavior of welded joints, but also can play an important role in health detection of structures subjected to mechanical loading.

• Journal of Multimedia Information System
• /
• 제5권2호
• /
• pp.99-104
• /
• 2018

Phishing website has become a crucial concern in cyber security applications. It is performed by fraudulently deceiving users with the aim of obtaining their sensitive information such as bank account information, credit card, username, and password. The threat has led to huge losses to online retailers, e-business platform, financial institutions, and to name but a few. One way to build anti-phishing detection mechanism is to construct classification algorithm based on machine learning techniques. The objective of this paper is to compare different classifier ensemble approaches, i.e. random forest, rotation forest, gradient boosted machine, and extreme gradient boosting against single classifiers, i.e. decision tree, classification and regression tree, and credal decision tree in the case of website phishing. Area under ROC curve (AUC) is employed as a performance metric, whilst statistical tests are used as baseline indicator of significance evaluation among classifiers. The paper contributes the existing literature on making a benchmark of classifier ensembles for web phishing detection.

• 대한약학회:학술대회논문집
• /
• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
• /
• pp.406.2-406.2
• /
• 2002

Special attention has been paid to human chorionic gonadotropin (hCG) for athlete doping control because it stimulates the endogenous production of testosterone and epitestosterone without increasing the T/E ratio which is a doping indicator for the exogenous administration of testosterone. Even though the IOC banned the use of hCG. a detection method has not been decided upon since there are a variety of immunoassay kits available on the market. We evaluated three kits in terms af their performance characteristics. (omitted)

• 정보관리학회지
• /
• 제19권1호
• /
• pp.115-134
• /
• 2002

비영리 조직인 도서관에서 정보화가 차지하는 비중이 점차 증대됨에 따라 시스템에 대한 감리와 통제만으로 지식정보자원관리를 조직의 경영목표에 적합하도록 유지하는 것이 어렵게 되었다. 그러므로 조직의 종합적인 경영체제 내에서 전체 경영활동과 통합되고 융화될 수 있도록 정보화 경영시스템의 적용이 필요하다. 도서관에서도 조직의 전략적 측면이나 사회 ·경제적인 요구들을 포함하는 포괄적인 문제를 고려하여 지식정보화 촉진과 경영혁신을 추구해야 한다. 본 연구는 모든 도서관에 적용할 수 있는 표준화된 규격으로 정보화경영시스템의 적용을 검토하였다. 이를 위해 지금가지 다양하게 개발된 도서관 성과지표와 정보화경영시스템의 수준평가표를 비교, 분석 하였으며, 도서관은 정보화경영시스템 도입을 통하여 조직의 효율성과 이용자 만족을 제고하고 나아가 국가경쟁력을 향상시킬 수 있게 될 것이다.

• The Journal of Asian Finance, Economics and Business
• /
• 제6권4호
• /
• pp.287-295
• /
• 2019

The study aims to build a model for evaluating the effectiveness of activities and the effectiveness of financial investments in high-tech industries in Kazakhstan. The development of high-tech industries plays an important role in the economic growth of a country. In this regard, it is relevant to study the effectiveness of financing the most important industry in Kazakhstan. The development of the high-tech sector ensures the efficient functioning of the national innovation system. High-tech enterprises are one of the competitive sectors that allow us to develop and implement leading-edge innovations with the goal of their subsequent commercialization domestically and abroad. The author defines the multicriteria of efficiency in a knowledge-based economy associated with achieving an economic effect with multivariate correlation of results with costs. A multivariate dynamic model, an integral indicator of performance, an integral indicator of cost-effectiveness is proposed. The assessment of the effectiveness of financial costs and performance indicators in all regions of Kazakhstan have the positive dynamics of indicators, as well as a high economic effect. The results of the study can be applied in regional management to adequately assess the effectiveness of high-tech organizations and the effectiveness of financial investments, contribution to ensuring the economic security of the region.

• 한국통신학회논문지
• /
• 제41권7호
• /
• pp.723-731
• /
• 2016

5G 이동무선통신에서 요구되는 증가된 데이터 속도를 제공하기 위한 핵심적인 기술 축은 대규모 어레이를 활용하는 MIMO 전송을 통한 주파수 효율의 향상이다. MIMO 전송을 위해서는 CSI-RS (channel state information-reference signaling)를 이용하는 채널 추정 및 추정 결과에 적합한 빔포밍이 필요하며, 따라서 빔포밍 벡터를 정의하는 코드북의 설계는 매우 중요한 이슈이다. 본 논문에서는 공간채널모델을 이용하여 생성된 채널의 통계적인 특성을 활용하여 DFT (discrete Fourier transform) 행렬 기반 다중 랭크 코드북의 설계 방안을 제안하였다. 제안 방식은 인접한 안테나 원소 간 위상차의 분포와 전송 레이어 별 선택되는 코드벡터의 특징을 고려하여 PMI (precoding matrix indicator)의 구조 변경을 하였으며, LTE (long-term evolution) 시스템에서 사용 중인 3GPP 표준 코드북과의 성능 비교를 통하여 제안 방식의 이득을 산출하고 검증하였다.